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1
Suman, Shivesh K. "Characterization of temperature variation during the wire bonding process." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17560.
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Wennergren, Karl Fredrik. "Metal Filling of Through Silicon Vias (TSVs) using Wire Bonding Technology." Thesis, KTH, Mikro- och nanosystemteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145552.
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Through Silicon Vias (TSVs) are vertical interconnections providing the shortest possible signal paths between vertically stacked chips in 3D packaging. In this thesis, TSVs are fabricated and two novel approaches for the metal filling of TSVs are investigated. A wire bonder is utilized to apply TSV core material in the form of gold stud bumps. The metal filling approaches are carried out by 1) squeezing stud bumps down the TSV holes by utilizing a wafer bonder and 2) stacking stud bumps on the outer periphery of the TSV holes and thereby forcing the material further down. Both approaches have successfully filled TSV holes of varying depths and no voids have been observed. The squeezing approach reaches measured depths of up to 52.9 μm and the stacking approach reaches depths of up to 100 μm.
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Chan, Yu Hin. "Optimization of metallization and process variables in low temperature wire bonding technology /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?MECH%202003%20CHAN.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.Includes bibliographical references (leaves 129-132). Also available in electronic version. Access restricted to campus users.
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Zhang, Xiaodong. "Characterization of copper diffusion in advanced packaging /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?MECH%202007%20ZHANG.
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Auersperg, Jürgen, D. Breuer, K. V. Machani, Sven Rzepka, and Bernd Michel. "FEA to Tackle Damage and Cracking Risks in BEoL Structures under Copper Wire Bonding Impact." Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-207250.
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With the recent increase in Gold (Au) wire cost Copper (Cu) wire becomes an attractive way to manage overall package cost. On the other hand, Copper wire bonding introduces much higher mechanical impact to underlying BEoL structures and actives because of the higher stiffness and lower ductility of Copper compared to Gold. These trends are accompanied by the application of new porous or nano-particle filled materials like low-k and ultra low-k materials for Back-end of Line (BEoL) layers of advanced CMOS technologies. As a result, higher delamination and cracking risks in BEoL structures underneath bonded areas represent an increasing challenge for the thermo-mechanical reliability requirements. To overcome the related reliability issues the authors performed a two level nonlinear FEM-simulation approach. Initially nonlinear axi-symmetric modeling and simulation of the copper bonding process are coupled with a spatial simulation model of the whole BeoL and bond pad structure. Cracking and delamination risks are estimated by a surface based cohesive contact approach and the utilization of a crushing foam constitutive material model for ultra low-k materials.
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Schatt, Nathan A. "Finite Element Modeling of Ultrasonic Wire Bonding on Polyvinyl Acetate-Nanocomposite Substrates." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1396634471.
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Pei-FuChung and 鍾沛孚. "Wire bonding characteristics of 0.7mil Au-Pd-plated Cu wires." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/75255799222694720740.
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碩士國立成功大學
工程科學系碩博士班
101
In semiconductor packaging industry, the wire bonding technology has been developed for a long time. Since the equipment and technology are more mature than the others, wire bonding technology is still the mainstream for packaging technology. For the material used in the process, copper wires have numerous advantages over gold wires. Copper wires can save the cost up to 30~50% compared with gold wires, and the high electrical conductivity, good thermal conductivity, high stability of wire and slower growth speed in intermetallic compound (IMC) are all the advantages making copper wires more favorable. The formation of the IMC can strengthen the bond, but the IMC layer has higher electric resistance. During the growth of the IMC, Kirkendall voids[31] will appear at the interface between the IMC layer and the wire, and the voids will enlarge to form cracks through heat treatment, thus leading to the deterioration of electrical contacts and the reduction of reliability of bondability. The materials used in this experiment are the 0.7mil Au-Pd-plated copper wires which are not yet on the market and the existing Pd-plated copper wires. The experimental results show that Au-Pd-plated copper wire has a better breaking load and better elongation than these of the Pd-plated copper wire. The micro-hardness test shows that Au-Pd-plated copper wire is softer than the Pd-plated copper wire. With the same forming gas flow rate, Au-Pd-plated copper wire has better FAB (Free Air Ball) formation roundness than the Pd-plated copper wire. This experiment also examines the coverage of the coating on the copper ball after the EFO (Electrical Flame-Off). By choosing seven different spots on Pd-plated copper wire for element analysis, it is observed that the surfaces are all covered with a layer of palladium, and there is no exposed Cu. Gold and palladium are also found on the surface of the Au-Pd-plated copper wire. The growth of IMCs (Intermetallic Compounds) test shows that the growth rate on Au-Pd-plated copper wire is the same as the Pd-plated copper wire. During the wire bonding process, the Pd-plated copper wire is found unstable in the formation of second bond stitch and on the joint with the finger. Moreover, the tails are cut-off too fast causing alarm of the equipment with short tail defect. However, the experiment result shows that with an extra layer of gold coated on the palladium layer, voids on the plating layer can be reduced and the work efficiency can be improved.
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Chiang, Tu-han, and 蔣篤翰. "LED Package Wire Bonding Performance Analysis." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/04921650589675330483.
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碩士大同大學
機械工程學系(所)
96
Wire Bonding is the one of the major circuit connection methods in current electronic packaging processes, which can enable the completion of circuit connectivity for chips or wafers with packaging substrate or Lead frame so as to achieve the purpose of electronic signal transmission. Wire bonding is part of the electronic packaging process, and its major function is to ensure the signal transmission between the electronic components, therefore the good wire bonding quality can accurately in addition to effectively transmit signals as intended. Currently, the trending for LED packaging components are leaning towards thinner and smaller, in comparison to the vital role assumed by wire bonding in the integral LED packaging process. Thus, among all the wire bonding quality indices, the values from forces of pulling and pushing will be used as inspection values for parameter modifications or fine-tuning efforts. This research is primarily based on LED packaging and it applies the comparisons between traditional wire bonding approach (Single) with current wire bonding approach (BSOB), as well as through the experimentation method, it placed the inspection results from the pulling and pushing values under the application of control charts to prove that, by using BSOB approach, it would create trustworthy product quality. Lastly, this research intends to find out and come up with enhancement strategies in regard to the causes for negatively influencing the wire bonding fabrications. Finally, this research applies case study for negativity analysis to prove the importance of pulling and pushing forces.
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薛宇廷. "Study of Wire Bonding &; Bonding Finger in Substrate of Semiconductor." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/63975762490733436657.
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碩士逢甲大學
工業工程與系統管理學系
101
With the diversification of digital products such as computers and cell phone in recent years, the packaging process of semiconductor has evolved from the traditional technology to the development of high-precision and high-power miniaturized process. Semi-conductor packaging needs to achieve the goal of high reliability, good heat dissipation, and low manufacturing costs. Facing the fluctuation in customer demand and the shortening of life cycle product, cross-cutting and system integration are two important issues. The wire bonding step occupies a pivotal position in the packaging process. Due to the rapid development of the integrated circuit packaging technologies, the traditional wire bonders with low speed, low precision, and low stability, can no longer to meet the demand of the industry. So, using wire bonders with thermal ultrasound functions instead is a trend. The wire bonding design, however, has a close relationship with the UPH of the wire bonder. This issue is also investigated in this study.
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Hung, Chong-Wei, and 洪崇偉. "The Study for Reliability of Wire-bonding Process by Copper Wire." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/3qe2x3.
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碩士國立高雄大學
電機工程學系碩士班
102
As technical developments progressed, semi-conductor packaging is now heading toward slender, high-density and high capillary count directions. At present, domestic package techniques are BGA(Ball Grid Array), QFP(Plastic Quad Flat Package), SOP(Small Out-Line Package), PLCC (Plastic Leaded Chip Carrier) and PDIP(PDIP Plastic Dual In-Line Package )based package techniques. Since BGA package technique generally involves solder ball arrayed at the base of chip base, solder ball replaces traditional lead frame surrounded by pins. One advantage of this type of package technique is that the No. of pins may increase with same size and area while the package area and weight are only half the QFP. It also has good electric and heat dissipation properties as well as package area reduction feature. Its demand and growth rate greatly exceed other package methods. Currently, most, information home electronic appliances and 3C products have adopted BGA package technique. This study aims is to pass reliability of wire-bonding process by copper wire. Based on the 3 quality characteristics of process intended for discussion, wire pull, ball shear , Internal Metal Coverage of the quality characteristics are obtained. Then, by use of Orthogonal array L9 and Reliability Temperature cycle Test, analysis why Internal Metal Coverage is the major factor to influence Open Test after Reliability . In addition, in order to pass reliability test, how to do good Internal Metal Coverage sample. The feasibility of this study method tested is further verified.
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Pequegnat, Andrew. "A Study of the Electrical Flame Off Process During Thermosonic Wire Bonding with Novel Wire Materials." Thesis, 2010. http://hdl.handle.net/10012/5136.
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Thermosonic ball bonding is the most popular method used to create electrical interconnects between integrated circuits (ICs) and substrates in the microelectronics industry. Traditionally gold (Au) wire is used, however with industry demands for lower costs and higher performance, novel wire materials are being considered. Some of these wire materials include Cu, insulated, and coated wires. The most promising of which being Cu wire. Some of the main issues with these wire materials is their performance in the electrical flame off (EFO) step of the wire bonding process. In the EFO step a ball called the free air ball (FAB) is formed on the end of the wire. The quality of the FAB is essential for reliable and strong ball bonds. In Cu wire bonding the hardness of the FAB and oxidation are the main issues. A hard FAB requires larger bonding forces and US levels to make the bond which increases the likelihood of damage to the IC. Excessive oxidation acts as a contaminant at the bond interface and can also influence the shape of the FAB. Shielding gases are required to reduce oxidation and improve FAB quality. This thesis focuses on the EFO process and the influence of EFO parameters and shielding gases on Au and Cu FABs. The primary focus of this thesis is to provide a better understanding of the EFO process in order to expedite the introduction of novel wire materials into industry.
Several different experiments are performed on an automated thermosonic wire bonder with 25 µm Au and Cu wires to investigate the EFO process during ball bonding. The effects of EFO parameters on the hardness and work hardening of FABs and the effects of shielding gas type and flow rates on the quality of the FABs are determined. The EFO discharge characteristics in different shielding gases is also studied to better understand how the composition of the atmosphere the FAB is formed in influences the energy input via the EFO electrical discharge.
Using the online deformability method and Vickers microhardness testing it is found that the EFO current (IEFO) and EFO time (tEFO) have a large influence on the hardness and work hardening of Au and Cu FABs. A harder FAB produced with a large IEFO and low tEFO will work harden less during deformation. The bonded ball will be softer than that of a FAB produced with a lower IEFO and higher tEFO. The online deformability method is found to be twice as precise as the Vickers microhardness test.
An online method for characterizing the quality of FABs is developed and used to identify shielding gas flow rates that produce defective FABs. The EFO process for an Au wire and two Cu wire materials is investigated in flow rates of 0.2-1.0 l/min of forming gas (5 % H2 + 95 % N2) and N2 gas. All three of the most common FAB defects are identified with this online method. It is found that good quality FABs cannot be produced above flow rates of 0.7 l/min and that H2 in the shielding gas adds a thermal component to the EFO process. It is recommended that the gas flow rate be optimized for each new wire type used.
The EFO discharge power is measured to be 12 % higher in a N2 gas atmosphere than in a forming gas atmosphere. The lower ionization potential of the forming gas leads to a higher degree of ionization and therefore lower resistance across the discharge gap. It was found that the discharge power does not determine the energy transferred to the wire anode because the Au FAB produced in forming gas has a 6 % larger diameter than that of the FABs produced in N2 gas. Other factors that effect the voltage of the EFO discharge include the controlled EFO current, the discharge gap, and the wire anode material.
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Lee, Jaesik Jay. "Process Quality Improvement in Thermosonic Wire Bonding." Thesis, 2008. http://hdl.handle.net/10012/3858.
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This thesis demonstrates the feasibility of methods developed to increase the quality of the crescent bond together with the tail bond quality. Low pull force of the crescent bond limits the usage of insulated Au wire in microelectronics assembly. Premature break of the tail which results in the stoppage of the bonding machine is one of obstacles to overcome for Cu wire. The primary focus of this thesis is to understand the tail and crescent bonding process and then to propose methodologies to improve thermosonic wire bonding processes when Cu and insulated Au wires are used.
Several series of experiments to investigate the crescent and tail bonding processes are performed on auto bonders. Cu and insulated Au wires with diameters of 25mm are bonded on the diepads of Ag leadframes. For simplicity, wire loops are oriented perpendicular to the ultrasonic direction.
It was found that the crescent bond breaking force by pulling the wire loop (pull force) with insulated Au wire is about 80 % of that of bare Au wire. A modification of the crescent bonding process is made to increase the pull force with insulated Au wire. In the modified process, an insulation layer removing stage (cleaning stage) is inserted before the bonding stage. The cleaning stage consists of a scratching motion (shift) toward to the ball bond in combination with ultrasound. Bonds are then made on the fresh diepad with the insulation removed from the contact surface of the insulated Au wire. This process increases the pull force of the crescent bond up to 26% which makes it comparable to the results obtained with bare Au wire.
An online tail breaking force measurement method is developed with a proximity sensor between wire clamp and horn. Detailed understanding of tail bond formation is achieved by studying tail bond imprints with scanning electron microscopy and energy dispersive x-ray analysis. Descriptions are given of the dependence of the tail breaking force on the bonding parameters, metallization variation, and cleanliness of the bond pad. Simultaneous optimization with pull force and tail breaking force can optimize the Cu wire bonding process both with high quality and robustness. It is recommended to first carry out conventional pull force optimization followed by a minimization of the bonding force parameter to the lowest value still fulfilling the pull force cpk requirement. The tail bond forms not only under the capillary chamfer, but also under the capillary hole. The tail breaking force includes both the interfacial bond breaking strength and the breaking strength of the thinned portion of the wire that will remain at the substrate as residue.
Close investigations of the tail bond imprint with scanning electron microscopy indicate the presence of fractures of the substrate indicating substrate material being picked up by Cu wire tail. Pick up is found on Au and Cu wires, but the amount of pick up is much larger on Cu wire. The effect on the hardness of the subsequently formed Cu free air ball (FAB) as investigated with scanning electron microscopy and micro - hardness test shows that Cu FABs containing Au and Ag pick ups are softer than those without pick up. However, the hardness varies significantly more with Au pick up. The amount of Au pick up is estimated higher than 0.03 % of the subsequently formed FAB volume, exceeding typical impurity and dopant concentrations (0.01 %) added during manufacturing of the wire.
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Chu, Yu-Ren, and 朱育仁. "Wire Bonding process capability improvement and analysis." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/54kc2k.
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碩士國立高雄大學
電機工程學系--先進電子構裝技術產業研發碩
97
Cost competitiveness is a major driving force in the semiconductor industry. The processing cost of an individual die is directly proportional to its size. Advances in processing technology have shrunk the device sizes in wire-bonded chips resulting in a smaller die core size. However the space below wire-bond pads remains relatively underutilized because of the reliability concern that electrical load transmitted during bonding can cause failures in the underlying devices. Recently studies have attempted to improve the use of space below wire-bond pads. Hence the circuits under pads (CUP) structure modified layout rules to include circuits structure under pads was developed and extensive qualification work is required to meet reliability standards. The main purpose of this paper is to investigate the damage caused by the wire bonding process of CUP devices on the in-line assembly packaging manufacture. The root cause of wire bonding failures analyzed was based on the CUP structure and several wire bond parameters; such as bonding force ultrasonic current bonding time period capillary type machine and wafer source that were also confirmed with the experiment plan of engineering technique. Finally results were also used to implement the corrective action and the assembly yield of CUP Device has been improved successfully.
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周正全. "Automatic Inspection System Design for Wire Bonding." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/58469863939722412446.
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博士國立交通大學
工業工程與管理系所
95
Wire bonding is the process that makes the connection between the IC chip and the substrate. The minimum diameter of a bonding wire, which appears as a 3D loop in an IC chip, is about 20 μm. This kind of bonding wire easily bends or sags in the middle segment. Bonding wire defects can be classified as 2D-type and 3D-type. The 2D-type defects include broken, lost, shifted or shorted wires. These defects can be inspected from a 2D top-view image of the wire. The 3D-type defect is wire sagging, which is difficult to be inspected from a 2D top-view image. In this dissertation, a structured lighting system was designed and developed to facilitate all 2D and 3D-type defect inspection. The devised lighting system can be programmed to turn the structured LEDs on or off independently. For the 2D-type defect, the lighting system can provide light in proper incident angle to illuminate the bonding wire and the position of bonding wire will be represented in the image clearly. For the 3D-type defect, we supplant the traditional height measurement by the slope inspection. The structured lighting system can provide light in proper incident range and the variance of slope, the sagged wire segment, will be highlighted in a 2D image. Experiments show that the devised illumination system is effective and robust for wire bonding defect inspection. We developed a fast and robust set of machine vision algorithms for wire bonding inspection. The defect of a bonding wire being broken, lost, shifted, shorted or sagged in an IC chip can be inspected automatically. Some illustrations are given to show the efficiency and effectiveness of this proposed novel wire bonding vision inspection system.
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Dai, Ruei-Rong, and 戴瑞鎔. "IC Wire Bonding Emulator Design and Control." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/22149832091341113276.
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Hsu, Kuo-Chuan, and 許國銓. "The Reliability Study of Cu Wire Bonding." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/11572771503107777308.
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Yen, Hung-Chung, and 顏鴻仲. "Study of Wire Bonding Process for LED." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8472gz.
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碩士國立虎尾科技大學
光電與材料科技研究所
103
In this study, we optimize the wire bonding process for 460 nm blue light emitting diodes (LEDs) chip. The LEDs can operate and enhance the reliability when the environment temperature changes by optimizing the wire diameter and wire camber. In addition, we can analyze the fail reason by fail samples. From the thermal cycle test (TCT), changing the wire diameter (from 1.0 mil to 1.2 mil) and the wire camber (from the normal loop to Q loop) which it can enhance the LEDs reliability, individually. On the other hand, it can enhance the LEDs reliability but it is no synergistic effect obviously using the 1.2 mil wire diameter and the Q loop wire camber at the wire bonding process. Finally, it can use different LEDs chip size and pass the 700 cycles thermal cycle test using the M loop wire camber.
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Lin, Ming-ho, and 林明和. "Prevent Wrong Bonding Process for Wire Bonder Using Automatic Bonding Program Verification." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/97456145781791130511.
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碩士國立高雄第一科技大學
電機工程研究所碩士在職專班
102
Wire bonding process plays a decisive role in semiconductor device fabrication during assembly and packaging process. The vigorous growth in 3C products has led to considerable increases in the market needs of semiconductor. The enterprise is always trying every attempt on profits increase, the way to reduce manufacturing costs is one of them. As a matter of fact, increase manufacturing yield and lower processing errors are the key factors of cutting down the manufacturing costs. Recipe is the key point of preventing wrong bonding process while the incorrect recipe parameters values and bonding locations are the root causes. This thesis is mainly focused on the following topics: 1. Download recipes to equipment automatically to avoid operators choosing the wrong one. 2. Get the running recipe from equipment to ensure equipment is processing correctly. 3. Recipe data structure analysis that demonstrates how to retrieve the information of parameters values and bonding locations for the further use of bonding diagram verification. 4. Recipe modification monitor that activates the process program verification scenario. 5. Recipe parameters values and bonding diagram verification. This thesis proposes the methodologies and mechanisms against the verification of parameters values and bonding diagrams. Recipe parameters are monitored against the corresponding groups and the values should be in the predefined range, whereas the bonding diagram is monitored by the bonding locations, the offset of X and Y coordinates compared with the golden Recipe should below the tolerated limitations. It has been proven to be feasible and effective by practical experiments. And the longest time it takes to verify is 6.087 seconds, hence the impact on production throughput is very trivial and could be ignored.
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Lin, Chun-Ting, and 林俊廷. "Optimizing the wire bonding process using silver alloy wire of laser diode." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5854f8.
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碩士元智大學
工業工程與管理學系
105
The researchs discusses the feasibility of applying silver alloy wires to the laser diode wires bonding process. Two basic damage tests: ball shear and wire pull, and seven environment reliability tests: mechanical shock, vibration, thermal shock, high temperature storage, low temperature storage, temperature cycling, damp heat were carried out on the finished goods. Respectively, this research analyese the impact of seven manufacturing parameters on laser diodes: (1) wire bonding temperature, (2) first wire bonding point force, (3) first wire bonding point ultrasound, (4) first wire bonding point timer, (5) second wire bonding point force, (6) second wire bonding point ultrasound, (7) second wire bonding point timer. The research uses principal component analysis to combine multiple responses, and uses the Taguchi method to analyze the optimal combination of the parameters. The optimal level of the seven parameters, are A1 wire bonding temperature, B3 first wire bonding point force, C3 first wire bonding point ultrasound, D2 first wire bonding point timer, E1 second wire bonding point force, F1 second wire bonding point ultrasound and G1 second wire bonding point timer. The confirmation experiments show that basic damage and environment reliability tests lie within the confidence interval of the response, which indicates the stability of silver alloy wires. The silver alloy wires are stronges than the gold wires after the basic damage tests. Also, the silver alloy wires have a smaller operation cuttent change than after gold wires after the environment reliability tests. The silver alloy wires can substitute gold wires in the laser diode wire bonding process.
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Ho, Ming-Chi, and 何明機. "Intermetallic Phases Formation Mechanism of Cu Wire Bonding and Phase Equilibrium Study of Ag Wire Bonding in the Electronic Packaging." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/ru5ky5.
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博士國立中山大學
材料與光電科學學系研究所
104
For lower cost considerations, copper wire bonding has been applied in IC packaging in recent years. In this study, the intermetallics(IMCs) formed, growth and crack development were examined to evaluate the reliability of several copper wires with/ without wire surface coatings.In this study, the reliability tests include HTST, PCT, and TCT. The wire types are the 0.7 mil 4N copper wires, the Palladium coated-Copper (Pd-Cu) wires, and Au-Pd-plated copper wires. And there are three substrate types with the aluminum pad thickness of 1.6/2.8/4 micrometer. For the HTST test samples, two aging temperatures, 175℃and 205℃ were applied and the aging periods from 150 hrs to 2000 hrs. The microstructure of micro joints are cross-sectioned and examined under an electron microprobe to verified the formed intermetallic phases for the samples tested in various aging periods. The samples under PCT and TCT tests are examined for the corrosion and crack formation behavior. The formation of IMCs, Cu9Al4, CuAl and CuAl2, which are main compounds formed in copper wire bonding micro joints. The Al-rich phase (CuAl2) has high priority, and the second phase(Cu9Al4) appear on the interface near the copper wire side. After long period aging, the Cu-rich phase(Cu9Al4) expected to form when Al pad be consumed. However, in the thicker Al pad cases, the Cu9Al4 phase will be replace by the first phase(CuAl2) finally. The results also show that, the kirkendall voids accumulate and form cracks in the bonding micro joint, and therefore make the micro joint fail. The intermetallic formation sequences of different wire types are shown for a comparison.The second part of study is about Ag wire bonding process. Ag wire has good electric conductivity, thermal conductivity, high current withstand capacity, and easy to store. However, compared to Au-Al wire bonding system, it is not enough to understand Ag-Al-Au phase diagram and the intermetallic formation of Ag-alloy wire bonding. This study of Ag wire can provide more information about diffusion paths and phase identification of Ag-Al-Au ternary system in the lower temperature.
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Lum, Ivan. "Effects of Ultrasound in Microelectronic Ultrasonic Wire Bonding." Thesis, 2007. http://hdl.handle.net/10012/3439.
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Ultrasonic wire bonding is the most utilized technique in forming electrical interconnections in microelectronics. However, there is a lacking in the fundamental understanding of the process. In order for there to be improvements in the process a better understanding of the process is required.
The mechanism of the bond formation in ultrasonic wire bonding is not known. Although there have been theories proposed, inconsistencies have been shown to exist in them. One of the main inconsistencies is the contribution of ultrasound to the bonding process.
A series of experiments to investigate the mechanism of bond formation are performed on a semi automatic wire bonder at room temperature. 25 µm diameter Au wire is ball bonded and also 25 µm diameter Al wire is wedge-wedge bonded onto polished Cu sheets of thickness 2 mm. It is found that a modified microslip theory can describe the evolution of bonding. With increasing ultrasonic power the bond contact transitions from microslip into gross sliding. The reciprocating tangential relative motion at the bond interface results in wear of surface contaminants which leads to clean metal/metal contact and bonding.
The effect of superimposed ultrasound during deformation on the residual hardness of a bonded ball is systematically studied for the first time. An innovative bonding procedure with in-situ ball deformation and hardness measurement is developed using an ESEC WB3100 automatic ball bonder. 50 µm diameter Au wire is bonded at various ultrasound levels onto Au metallized PCB substrate at room temperature. It is found that sufficient ultrasound which is applied during the deformation leads to a bonded ball which is softer than a ball with a similar amount of deformation without ultrasound. No hardening of the 100 µm diameter Au ball is observed even with the maximum ultrasonic power capable of the equipment of 900 mW.
In summary, the fundamental effect of ultrasound in the wire bonding process is the reciprocating tangential displacement at the bond interface resulting in contaminant dispersal and bonding. A second effect of ultrasound is the softening of the bonded material when compared to a similarly non-ultrasound deformed ball.
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Satish, Shah Aashish. "Mechanical and Tribological Aspects of Microelectronic Wire Bonding." Thesis, 2010. http://hdl.handle.net/10012/5109.
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The goal of this thesis is on improving the understanding of mechanical and tribological mechanisms in microelectronic wire bonding. In particular, it focusses on the development and application of quantitative models of ultrasonic (US) friction and interfacial wear in wire bonding. Another objective of the thesis is to develop a low-stress Cu ball bonding process that minimizes damage to the microchip. These are accomplished through experimental measurements of in situ US tangential force by piezoresistive microsensors integrated next to the bonding zone using standard complementary metal oxide semiconductor (CMOS) technology. The processes investigated are thermosonic (TS) Au ball bonding on Al pads (Au-Al process), TS Cu ball bonding on Al pads (Cu-Al process), and US Al wedge-wedge bonding on Al pads (Al-Al process).
TS ball bonding processes are optimized with one Au and two Cu wire types, obtaining average shear strength (SS) of more than 120 MPa. Ball bonds made with Cu wire show at least 15% higher SS than those made with Au wire. However, 30% higher US force induced to the bonding pad is measured for the Cu process using the microsensor, which increases the risk of underpad damage. The US force can be reduced by: (i) using a Cu wire type that produces softer deformed ball results in a measured US force reduction of 5%; and (ii) reducing the US level to 0.9 times the conventionally optimized level, the US force can be reduced by 9%. It is shown that using a softer Cu deformed ball and a reduced US level reduces the extra stress observed with Cu wire compared to Au wire by 42%.
To study the combined effect of bond force (BF) and US in Cu ball bonding, the US parameter is optimized for eight levels of BF. For ball bonds made with conventionally optimized BF and US settings, the SS is ≈ 140 MPa. The amount of Al pad splash extruding out of bonded ball interface (for conventionally optimized BF and US settings) is between 10–12 µm. It can be reduced to 3–7 µm if accepting a SS reduction to 50–70 MPa. For excessive US settings, elliptical shaped Cu bonded balls are observed, with the major axis perpendicular to the US direction. By using a lower value of BF combined with a reduced US level, the US force can be reduced by 30% while achieving an average SS of at least 120 MPa. These process settings also aid in reducing the amount of splash by 4.3 µm.
The US force measurement is like a signature of the bond as it allows for detailed insight into the tribological mechanisms during the bonding process. The relative amount of the third harmonic of US force in the Cu-Al process is found to be five times smaller than in the Au-Al process. In contrast, in the Al-Al process, a large second harmonic content is observed, describing a non-symmetric deviation of the force signal waveform from the sinusoidal shape. This deviation might be due to the reduced geometrical symmetry of the wedge tool. The analysis of harmonics of the US force indicates that although slightly different from each other, stick-slip friction is an important mechanism in all these wire bonding variants.
A friction power theory is used to derive the US friction power during Au-Al, Cu-Al, and Al-Al processes. Auxiliary measurements include the current delivered to the US transducer, the vibration amplitude of the bonding tool tip in free-air, and the US tangential force acting on the bonding pad. For bonds made with typical process parameters, several characteristic values used in the friction power model such as the ultrasonic compliance of the bonding system and the profile of the relative interfacial sliding amplitude are determined. The maximum interfacial friction power during Al-Al process is at least 11.5 mW (3.9 W/mm²), which is only about 4.8% of the total electrical power delivered to the US transducer. The total sliding friction energy delivered to the Al-Al wedge bond is 60.4 mJ (20.4 J/mm²).
For the Au-Al and Cu-Al processes, the US friction power is derived with an improved, more accurate method to derive the US compliance. The method uses a multi-step bonding process. In the first two steps, the US current is set to levels that are low enough to prevent sliding. Sliding and bonding take place during the third step, when the current is ramped up to the optimum value. The US compliance values are derived from the first two steps. The average maximum interfacial friction power is 10.3 mW (10.8 W/mm²) and 16.9 mW (18.7 W/mm²) for the Au-Al and Cu-Al processes, respectively. The total sliding friction energy delivered to the bond is 48.5 mJ (50.3 J/mm²) and 49.4 mJ (54.8 J/mm²) for the Au-Al and Cu-Al processes, respectively.
Finally, the sliding wear theory is used to derive the amount of interfacial wear during Au-Al and Cu-Al processes. The method uses the US force and the derived interfacial sliding amplitude as the main inputs. The estimated total average depth of interfacial wear in Au-Al and Cu-Al processes is 416 nm and 895 nm, respectively. However, the error of estimation of wear in both the Au-Al and the Cu-Al processes is ≈ 50%, making this method less accurate than the friction power and energy results. Given the error in the determination of compliance in the Al-Al process, the error in the estimation of wear in the Al-Al process might have been even larger; hence the wear results pertaining to the Al-Al process are not discussed in this study.
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Chen, Chia-Hsu, and 陳家旭. "Experimental and Finite Element Analyses on Wire Bonding." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/56788170089122720277.
Full textAbstract:
碩士國立交通大學
機械工程系
90
Wire bonding is the most popular interconnection method in electronic packaging. The controlled parameters significantly affect the bonding strength when the tiny golden wires(25μm in diameter) are used in this process. This study examines how parameters and bonding strength are related by performing experimental and finite element analyses. Bonding experiments were conducted to examine how various combinations of controlled parameters affect both the forming of golden ball connection and the resulting bonding strength. Moreover, finite element simulations on the wire bonding were performed, with the results compared with those of experimental works.
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Lin, Yu-Ping, and 林煜斌. "Study of wire bonding process forNiPdAu PPF leadframe." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/56213024364721947837.
Full textAbstract:
碩士國立成功大學
工程科學系專班
94
Because of the growing environmental consciousness, NiPdAu PPF leadframe that eliminates plating process of plastic package is already used widely in semiconductor industry at present, as a green products component. The research is to study crescent bonding bondability on the inner finger of NiPdAu PPF leadframe. Through Taguchi methods and analysis of variance are used to evaluate related matters that influence crescent bonding bondability including thickness condition of NiPdAu, capillary dimension, gold wire type, process condition, bonding parameter. The software packages JUMP and MINITAB are used to analyze through the course of the experiment. In the mean time, the bonding formation of gold crescent bond on the inner finger of NiPdAu PPF leadframe is also examined. Thus, metal microstructure and surface morphology of NiPdAu PPF leadframe which might influence crescent bonding bondability on the inner finger can be understood. Through this study, an optimized bonding process to achieve good crescent bond bondability is obtained.
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Chen, Po-kuang, and 陳柏光. "Wire Bonding Parameters Optimization by Using Taguchi’s Method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/05439336593088751228.
Full textAbstract:
碩士逢甲大學
資訊電機工程碩士在職專班
98
Abstract On the development of electrical technology and consumer’s demand on the electric products, humans never stop chasing on the trend of high performance and complex. Based on the innovation of SOP (small outline package) technology, it is always on the movement of high pincounts (I/O), miniaturization and low cost. During the process of wire bonding, it uses gold wire to connect chips and substrates in order to bridge the electric signals in the Integrated Circuits, IC. The wire bonding process of semiconductor is on the progress of developing the high precision wire bonding technology of the bond pad fine pitch; furthermore, it also focuses on upgrading the skill of wire bonding. Therefore, the parameters are extremely important on the innovation of manufacturing process. Based on the optimization parameters, it is not only reducing the timeframe of innovation process, but it can also decrease the cost. Regarding to the variable quality characteristics on products and the optimization parameters, most of engineers make their determination only relied on their own personal experiences based on its different quality characteristics to distinguish its optimization combination for each characteristic. Therefore, an important subject what this industry is most concern about is how to utilize the optimization combination to discover the optimization parameters. This research will be focused on the operation of wire bonding via experimenting Taguchi’s method to determine the key factors, levels and optimization parameters. To analyze the strength of first bonding, it can apply the gold ball shear test and the quality characteristics of gold ball size. And then, the gold wire pull test can examine the strength of second bonding. As a result of the experiment, the optimization quality characteristics can be verified.
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Wu, Cheng-Kuei, and 巫正奎. "Optimization analysis of silver wire package bonding parameters." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/78498669407253368968.
Full textAbstract:
碩士國立中央大學
機械工程學系在職專班
104
Packaging wire bonding technology has been around for ages, is electrical connection technology, widely used in the microelectronics field, facing high density, complexity, small size of portable low-cost products, we need to implement mounting technology to match. General industry use material which is close to gold 4N (99.99%) as a package lead wire, but with the price of gold per ounce from USD 255 in 2001, rose to the highest in 2011 at USD 1900 per ounce, which result in manufacturing cost increase and profit goes down for the industry which use pure gold as main packaging wire. In order to get rid of the sharp rise in the cost of material, packaging factory began to replace gold wire by copper wire. However, copper is easily oxidized and difficult to store, and in the wire bonding need to use an inert gas; on the other hand because of the higher strength and hardness of the copper wire make wire bonding operation parameters encountered narrower, slower and yield high defect rate, above also limits the copper wire in the electronics packaging industry popularity. Although the price of silver is higher than copper, but lower than gold. Silver don’t has the nature of Copper easily oxidized, too high strength and hardness. In the packaging wire bonding process, Silver play the new role of wire material. During wire work, wire machine with lots of complicated parameters can be adjusted. In order to shorten the time to adjust parameters of wire machine, let silver wire and the baseboard has a better bonding, which can reduce the possibility of defect rate on following process. In this study, 2N silver wire (99%) 0.8 mil diameter as the theme, after the wire annealing, cleaning, baking, referring Taguchi orthogonal arrays, using vacuum time and wire parameters as factors, after wire bonding, pointing at bondability between silver wire and base board, perform tensile test and push ball test, and the application with TOPSIS for experimental cooperation merits of multiple quality sorting, and then by gray correlation method for solving the optimal experimental parameters, using statistical analysis software within the SN ratio prediction function to predict and compare the results, verify and obtain the best process parameters.
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Chao-YungWang and 王朝永. "Wire bonding process optimization for overhang stacked die." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/30114140299774717326.
Full textAbstract:
碩士國立成功大學
工程科學系專班
101
The portable devices created under the trend of lightness, thinness and smallness have triggered a massive wave of buying. This trend has also leaded to the popularity of flash memory. Since these portable devices need larger and larger memory storage space, for example, the enhanced pixel count for digital cameras, manufacturers keep developing flash memories with larger capacities to meet the requirements of the consumer need. However, the internal space of the small form factor portable device is restricted and unable to accommodate more memory components to expand the memory capacity. Therefore, manufacturers have to find a way to expand the memory capacity of the flash memory in a single package, and this relies on the advances of the semiconductor manufacturing technology and capability. This study takes the die thickness of 1.2 mils as the test object to develop a nine-layer overhang-stacked package for microSD card, the smallest flash memory in size. Without changing the equipment and materials currently used, this study focuses on the investigation of the required equipment and software by applying Taguchi method to optimize the wire bonding yield and quality. Reverse bonding is applied, and ball shear test and wire pull test are used to measure the bonding conditions on bonding pads, gold balls and gold wires. At 90% confidence level, the significant control factors are found and the relatively optimal process parameters are obtained. S/N ratios for ball shear and wire pull after optimization improves by 6.94 dB and 1.25 dB respectively. Moreover, the finite element analysis software ANSYS is used to simulate the stress and deformation during wire bonding on the overhanged chips so as to verify satisfied mechanical strength of the optimization results obtained by the Taguchi method.
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Hsu, Wei-Chen, and 徐暐宸. "Reliability Test about AuPdCu Wire Materials of Wire Bonding Processing in Semiconductor Assembly." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/23aw6u.
Full textAbstract:
碩士國立高雄科技大學
工業工程與管理系
107
This paper focuses on the wire materials change from widely used Au wire, Ag alloy wire, bare Cu wire, Pd-Cu wire to Au Pd-Cu wire in wire bonding processing of Semiconductor Assembly. The reason why various materials appear is due to the consideration on cost. Currently, the electrical products’ body sizes become smaller and the prices also become cheaper. As a result, the change on material can improve the overall cost. Under the premise that it can meet the requirement of lowing cost and maintaining the quality, not only needs the improvement of process but also the material development. This research will take the new Au Pd-Cu wire as the major research material. Comparing with the bare Cu wire and Pd-Cu wire, the workability and the reliability of Au Pd-Cu wire are more prominent. This study shows that Au Pd-Cu wires have better distribution on wire surface, and also enhance the reliability to achieve the requirement of high reliability.
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Chang, Chao-Lin, and 張肇麟. "A study on Optimum Parameters of Wire Bonding with Material and Alloy wires." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/32tykh.
Full textAbstract:
碩士國立彰化師範大學
電子工程學系
102
The copper wire bonding process is already the mainstream in IC assembly industry. This research focus on solving the technological bottlenecks in copper wire bonding process. They are capillaries, copper alloy wires, and parameters in wire bond process. The application of response surface methodology in direct materials and indirect materials in order to optimize all processes and improve capability. At the first, this research focus on the design of capillary. It shows that the most optimize capillary format is H(1.05 mil), CD(1.3 mil), ICA(70°), OR(0.5mil), FA(8°).Then, by studying three different copper alloy wires. Comparing the pure copper wire, Pd copper wire and Au-Pd alloy copper wire. The new Au-Pd copper wire is the most optimize direct material. The application of response surface methodology in the most optimize capillary and wire. The optimize parameter was been found. The Seg1 Force is 45±5, Seg3 Power is 80±5, Seg3 Time is 12±4, and Seg3 Force is 10±2.Finally, proceed three reliability tests (TCT, HTSL, and HAST).After those tests, no failure modes were been detected. This study compared the direct materials with indirect materials. And the results have the significantly capability improvement in the copper wire bonding process at IC assembly industry.
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YANG, CHU-WEN, and 楊筑雯. "The Investigation of Relationship between Wire Bonding Process Parameter and Reliability of Copper Wire." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/2687t5.
Full textAbstract:
碩士國立高雄大學
電機工程學系--先進電子構裝技術產業研發碩士專班
105
The study focuses on the bonding parameters and its relationship to the product reliability of copper wires in IC packaging. In general, palladium can be used to protect copper balls from attack of chlorine ions that are inherent to molding compounds which will avoid the reliability and field failures on humidity environment. In this experiment, the best parameters were found for EFO Current、EFO Gap、and Forming Gas rate to produce the best “post bond palladium coating distribution” on the copper ball. A reliability test was used to verify the effectiveness and found to have no failure.
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Chen, Jung-Chi, and 陳榮棋. "A Study on Optimum Parameters of Wire Bonding for Alloy Wire in IC Assembly." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/67748255271241755361.
Full text
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Chen, Yi-feng, and 陳儀峰. "The Material Characteristics of Gold Wire/Copper Wire and Dynamic Response on Bonding Process." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/71578047131210425689.
Full textAbstract:
碩士義守大學
機械與自動化工程學系碩士班
97
Wirebonding assembly has been widely used in the semiconductor package for the past two decades. The welding wire bonding technology is based on electricity as a link and as the transmission of signals. Material strength of copper wire is higher than gold wire. Higher strength copper brings about Al pad shovel (excessive plastic deformation) around the ball bond when wirebonding process is conducted. Reliability in Copper wire bonding process includes ball lifted, peeling and cracking beneath bond pad. Manufacturing process also required special attention to prevent oxidation. This research involves in four parts: In the first, Young’s modulus on ultra thin surface is experimentally determined by nano indentation instrument. Secondary, Atomic Force Microscopy (AFM) is applied to measure interfacial frictional coefficient and the surface roughness. In the third, corrosion experiments for gold wire and copper wire are performed and observed for metallographic. The last is that numerical prediction for wirebonding process is conducted based on commercial finite element software of ANSYS/LS-DYNA. The surface tensile mechanical properties for ultra thin gold wire, copper wire and Al pad are obtained through nonointentation technology. Atomic Force Microscopy (AFM) is applied to measure the micro surface coefficient of frictional force. The measured interfacial coefficient of frictional force between silicon-based cantilever beam and specimen material need to be correlated on thrust force and normal force. Surface roughness on Al pad is specially focused because uneven surface will affect the wire bonding process. Therefore, the interfacial frictional mechanism on Al pad needed to be carefully analyzed. The accurate experimental material data should be reflected as input for the precise finite element analysis. Numerical model based on explicit time integration scheme software ANSYS/LS-DYNA is developed to predict the first bond (ball bond) of wirebonding process. The impact effects on structure stressed area during wire bonding process are investigated and the shovel (large plastic deformation) of Al pad was observed during transient ultrasonic vibration stage. It is noted that the material of bond pad should be Al-Cu pad instead of pure Al pad. Special emphasizes are focused on the underlay via layouts and the optimal design of microstructure beneath the bond pad. A series of comprehensive parametric studies were conducted in this research.
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Her, Tian-Lou, and 何天露. "Design Optimization in a Loop of Wire Bonding Profile." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/45279280043800015269.
Full textAbstract:
碩士國立成功大學
機械工程學系
86
The purpose of this thesis is to simulate the capillary trajectory between first bond and second bond process and then find out the optimum trajectory in wire-bonding loop. This thesis has established an analysis model to simulate the capillary trajectory during the up and down processes successfully. Model of the up process includes the primary type, the two-plastic type, and the three-plastic type; Model of the down process is the Spring Rigid-bar Model. The experiments of the three kinds of types are done by a simple simulation test. Then, the heat transfer phenomenon and transient temperature distribution along the gold wire during wire-bonding process is discussed and the material's properties are modified. Then, the constraint of all bonding process and bonding requirement are discussed and three design examples are also presented. At last, the objective function of optimum design is defined and two feasible capillary trajectories are compared.
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Chang, Ting-how, and 張庭豪. "The wire bonding of chip Nickel Palladium bond pads." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/09133995849855272203.
Full textAbstract:
碩士逢甲大學
材料與製造工程所
95
This thesis was mainly to address gold wire bonded with different materials of wafer bond pad during assembly process .Based on advantages and disadvantages of gold wire bonded with aluminum pad which we often see, the thesis was to compare and contrast Nickel-Palladium Pad bonded with gold wire. Besides, we analyzed the workability and reliability of Ni-Pd pad bonded with gold wire. In the study, the correlation between four kinds of wire bonder parameter, were used as a control group and the best parameter of Ni-Pd Pad bonded with gold wire came out. According to Taguchi Quality Engineering , we found the proof that “Bond Temperature” is not the main factor to affect wire pull and ball shear. Therefore, the best parameter came out from the experiment is: 1. Bond Force: 30gf 2. Bond Power: 55μW 3. Bond time: 10μs By way of the above parameters , we can get the most stable workability of Ni-Pd pad and gold wire.After 1000 cycles of temperature cycling test ,there weren’t any inter-metallic crack occured between surface of the Ni-Pd pad and gold wire.
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陳慧昌. "Study on Wire Bonding Process for Chip Scale Packaging." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/47413149638862197934.
Full textAbstract:
碩士國立中正大學
機械系
88
The subject of this work is study of optimal bond parameters on wire bonding process for chip scale package on low temperature cofine ceramic substrate by using Taguchi method. In order to understand which the most effect process factor. Capillary amplitude-time diagrams during the ultrasonic bonding process were recorded and analyzed. Finally, using chemical etch method to split bond ball and pad and investigation ball shape, wedge shape, real contact area and gold wire HAZ grain growth by using SEM. The experimental result get optimal processing parameters was: The first bond parameters is bonding power 60unit, bonding force 50g, bonding time 30msec, sink 2unit, spark current 4.7 unit, spark time 3.0msec and tail length 70 unit. The second bond parameters is bonding power 90unit, bonding force 90g, bonding time 20msec and sink 2unit. It was founded that the most effect factor is bonding power in the bonding process. Result from the Ultrasonic amplitude measure the capillary amplitude is increases when the bonding power is upgrade and is drop-off when the bonding force is upgrade. This is in agreement with those results obtained from process parameters. The bonding time and sink is not effect to amplitude. Finally, from the SEM investigation showed gold wire thermosonic wire boning very like aluminum wire ultrasonic wire bonding on real contact area — circular bond. The real contact area will close to appear contact area with increasing the process parameters.
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Wu, Dong-Jing, and 吳東璟. "The Study of Wire Bonding in Infrared Emitting diodes." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/42640053542046076274.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
89
There are three subjects in this study: 1. Analyzing the bonding pad of IrED chips in AES, and then judging the effect of reliability with different cleaning processes and packaging types. 2. Comparing the affects of different capillary design factors, and choosing best capillary parameters of IrED wire bonding process. 3. Using different capillary forces and ultrasonic powers for IrED wire bonding processes and evaluating their influences in the degradation of light power. The results are as following: 1. With AES analysis, gallium existed on the bonding pad of the IrED chips. 2. Whether cleaning process acts or not, there were no significant effects in shear stress test and light power degradation for the IrEDs. 3. The type of the package had influence on light power degradation and T-1 3/4 package had lower degradation speed than that in IrDA module. 4. The best parameters of capillary for IrED wire bonding processes are: Tip Finish; H: 0.0018in; T: 0.0090in; OR: 0.0015in. 5. Improper capillary forces and ultrasonic powers would degrade the light power of the IrED rapidly.
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Ho, Ming-zhe, and 何明哲. "Failure mechanism of wire bonding in IC package process." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/30674209529454619280.
Full textAbstract:
碩士國立中山大學
電機工程學系研究所
92
Aluminum bond pads on semiconductor chips play an important role in IC device reliability and yield. In the paper, the vertical tension loading transferred from the capillary is clarified as the direct driving force for bond pad metal peeling. The crack on the bonding pad is identified as the root cause of the pad peeling. It is simulated by finite element method to find the effect of driving force resulting in the crack during the ultrasonic wire bonding process. It indicated that the horizontal vibration of the capillary controlled by ultrasonic power of the bonding machine was the main factors led to the crack on the bonding pad as well as its propagation into the oxide layers in chip. The degradation of Au wire/Al bond pad has become a major bonding failure problem. It is because that the molding resin with low thermal stability (e.g. bi-phenyl epoxy resin) and the IC devices under high thermal environments were used in packaging process. For the lifetime to bond failure, the bi-phenyl epoxy molding becomes shorter than that for cresol novolac epoxy due to the corrosion reaction of Au-Al intermetallics with bromine (Br) contained in the resin compounds. It was clarified that the reactive intermetallic was Au4Al phase formed in the bond interface. In addition, by utilizing the SEM, AES, EDS and XPS techniques, it could be carried out to reveal and identify defects underneath Al layer, and the contaminated Al bond pads could cause poor intermetallic growths led to the failed or unreliable connections from the chip to the outside world.
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陳大殿. "Analysis of Thermosonic Wire Bonding Process for Electronic Packaging." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/34398946780206519089.
Full textAbstract:
碩士國立中正大學
機械系
87
Abstract In this work, the effect of process parameters on the bonding strength, morphology and also the interaction between different parameters was studied. Tensile test and ball shear test on bonded gold wires were conducted to evaluate the bonding strength. Investigation of ball shape and wedge shape was conducted by using SEM. Weldability windows for optimal parameters were established according to the results obtained from destructive test and microscopic examination. Load-time diagrams during the ultrasonic bonding process were recorded and analyzed. Using the parameter data obtained from the experiment for weldability window and combining the neural network technique, a neural network prediction model can be established. Weldability windows of the thermosonic wire bonding was obtained, and the influence of bonding parameters on the ball bond strength can be traced according to the windows. The thermosonic wire bonding process was divided into three subprocesses, namely, applying welding load, applying welding power, and unloading. Results from ball bond shear test the real bonded area increases with the increasing power and thus the bonding strength increase accordingly. Real bonded area also increases slightly with increase bonding force. This is in agreement with those results obtained from weldability window. SEM investigation showed the effect of wire bonding parameters on the shape and morphology of the bonding and the type of wire loop. The optimal processing parameters obtained by using Taguchi method was: bonding power : 0.28W, bonding force :110g, bonding time :20 msec, wire tail : 300μm, bonding sink :7 pulse. The neural network model predicted the bonding strength resulted from different bonding parameters precisely.
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Tsai, Yi Tsung, and 蔡貽宗. "Stress Analysis of Cu Chip Under Wire Bonding Process." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/89451780870661356439.
Full textAbstract:
碩士國立中正大學
機械系
91
In order to improve the IC performance, Cu chips which combined copper interconnects with Low-K dielectric material are the trend of future IC development. Due to the low mechanical properties of Low-K materials, the chips may fail during the wire bonding process. In this research, nonlinear dynamic Finite Element Method (FEM) software (ABAQUS/Explicit) is used as a simulation tool, the material properties of the gold ball is assumed properly, and a two-step load curve is proposed to modify the effect of bonding force and ultrasonic vibration. The final ball bond simulation results are validated well with experimental data. The validated FEM model is used during the bonding process to understand the stresses generated in the bonded device. The results shown that to increase the bonding force dose not effect on the peak value of the contact pressure. Select Cu pad can better reduce the stresses in the chip. Moreover, to design Cu chip with FSG and SiO2 layer can obtain less sinking value of the bonding pad.
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Jang, Hung-Sheng, and 張弘昇. "Bondability Analysis and Reliability Design on Copper Wire Bonding." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/28877948787564001882.
Full textAbstract:
碩士義守大學
機械與自動化工程學系碩士班
98
The wire bonding process has been widely used in the semiconductor package industry for the past two decades for its easy application and low cost. However, the mechanism of dynamic response for wire bonding process is scarcely reported due to the material data is difficultly to determine. As the price of gold is dramatically increasing in the year of 2009, engineers and researchers have been focused on the replacement material of copper wire. In order to reduce the cost, we use copper wire in substitution for gold wire.Copper wire has better electrical conductivity and thermal conductivity than gold wire, but copper wire is oxidation easily and material strength is higher than gold wire. It maybe brings aluminum pad squeeze (excessive plastic deformation) because material strength of copper wire is high. This research involves in three parts: the first is we etching copper wire and use SEM to see the grain. Secondary, Atomic Force Microscopy (AFM) is applied to measure interfacial frictional coefficient and the surface roughness, and we take the data into ANSYS to simulate. In the third, numerical prediction for wire bonding process is conducted based on commercial finite element software of ANSYS/LS-DYNA. In this research, we take our attention in aluminum pad squeeze, so we use metallography experiment to understand the grain become big and the material strength is lower. It is noted that the material of bond pad should be Al pad instead pure Al pad. Special emphasizes are focused on the via layouts and the optimal design of microstructure beneath the bond pad. A series of comprehensive parametric studies were conducted in this research.
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Lai, Ming Yu, and 賴銘悠. "Process Capability Analysis for Wire Bonding of IC Packaging." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/64218079497186595513.
Full textAbstract:
碩士國立勤益科技大學
工業工程與管理系
98
In the semiconductor manufacture, the purpose of IC packaging, one of the back end processes, is to build the complete frameworks of IC chips while to protect the chips from physical damage and chemical change caused by the surroundings which will affect IC’s efficiency. For electronic signal distribution, on the other hand, an IC chip has to be connected with substrate or lead frames to form circuits and transmit signal between the chip and the carrier. Currently, wire bonding is the best approach of electrical interconnection. Process Capability Indices (PCIs) can be used to evaluate whether the product quality meets the requirements or not. PCIs, in general, are applied to estimate the performance of products with single characteristic. Whereas IC wire bonding process has multi-characteristic, in this paper, we use multi-process capability analysis chart (MPCAC) associating with the values of total process capability index and entire process yield, setting low confidence bounds of individual indices, for qualities analysis and control. This evaluation model of IC wire bonding will make it easy for engineers to control the procedure, improving yield and qualities.
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Cheng-Li, Chuang, and 莊正利. "Study on the Thermosonic Wire Bonding Process and Bonding Mechanism for Chips with Copper Interconnects." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/96205801478185877513.
Full textAbstract:
博士國立中正大學
機械系
92
Abstract As semiconductor devices are reduced in scale, the dimension of interconnects shrinks to the sub-micron level. The resistance-capacitance (RC) time constant becomes a major part of total delay. In order to reduce the RC time constant, the chip with copper interconnects and low k materials were proposed IBM in 1997. However, copper easily oxidizes at elevated temperature; oxidation is thus a serious concern in thermosonic wire bonding of gold wire onto chips with copper interconnects. Thermosonic wire bonding was conducted at 90℃-200℃ under air atmosphere. The bondability and bonding strength of Au/Cu bonds were far below the minimum requirements stated in industrial codes. The degradation was attributed the formation of copper oxide on copper pad. After heating at 90℃, 150℃ and 200℃ for 5min under air atmosphere, two kinds of copper oxides were identified based on the shifted binding energy. Cu(OH)2 forms mainly on the top surface of copper pads and the underlying layer consists mainly of CuO. Thus, protective measures such as deposition of a passivation layer or using shielding gas are inevitable for thermosonic wire bonding on chips with copper interconnects. In this work, three schemes were proposed to achieve a 100% bondability and sufficient bonding strength for gold wire thermosonic bonding to copper pad. First, the argon shielding methods were applied to prevent copper pad from oxidizing during gold wire thermosonic bonding to copper pad. With argon shielding in the thermosonic wire bonding process, 100% gold wire attach on copper pad can be achieved at bonding temperature of 180℃ and above. The ball-shear force and wire-pull force far exceed the minimum requirements specified in the related industrial codes. In a suitable range of bonding parameters, increasing bonding parameters resulted in greater bonding strength. The reliability of high temperature storage (HTS) test for Au/Cu ball bonds was verified in this study. The bonding strength of Au/Cu ball bonds increases slightly with prolonged storage duration due to atomic diffusion between gold ball and copper pad during HTS test. As a whole, argon shielding is an effective way to ensure Au/Cu ball bond in the thermosonic wire bonding process applied for packaging of chips with copper interconnects. Second, a thin titanium passivation layer was deposited onto Cu pad to improve the bondability and bonding strength. The thickness of titanium passivation layer is crucial to bondability and bonding strength. An appropriate thickness of 3.7nm titanium film is proposed in this work. 100% bondability and high bonding strength was achieved. A thicker titanium film results in poor bondability. The mechanisms for successful bonding lies in that only film with suitable thickness can be removed by an appropriate range of ultrasonic power during thermosonic bonding. The protective mechanism of titanium passivation layer was interpreted by the results of FEAES and ESCA analysis. Titanium dioxide (TiO2) formed during die saw and die mount process plays an important role in preventing the copper pad from oxidizing. The bonding strength did not degrade after prolonged storage at elevated temperature during HTS test, thus the reliability of HTS test for gold ball bonded on copper pad with titanium layer was verified. The third proposal is to deposit a silver layer on the surface of copper pad as a bonding layer. Both ball-shear forces and wire-pull forces of gold wire bonding to copper pads with silver bonding layer are far higher than that minimum requirements stated in JEDEC standard and MIL specifications. Silver bonding layer reveals superior bonding strength on Au/Ag interface. The reliability of Au/Ag bonds after high temperature storage test is also validated. The bonding strength increases with increasing holding time. The wire-pull forces far exceed the industrial codes. Bondability and bonding strength for gold wire thermosonic bonding to chips with copper interconnect is significantly improved by the deposition of silver as a bonding layer on copper pads. According to experimental results in this work, three protective methods not only prevents copper pads from oxidation during thermosonic wire bonding process but also could be applied to the electronic packaging industry for solving the challenges of thermosonic wire bonding process on chip with copper interconnects.
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Mei-YuChen and 陳眉瑜. "Studies on EFO Characteristics and Wire Bonding Electrification Effects of Ø20μm Ag-2Pd Alloy Wire." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/u7q2wm.
Full textAbstract:
碩士國立成功大學
材料科學及工程學系碩博士班
101
In the packaging industry, Ag wire has the potential to replace Au wire due to its superior electrical properties, lower cost and similar mechanical properties compared with Au. When Ag wire bonds to Al pad, the growing and brittle Ag-Al intermetallic compounds (IMCs) will cause the failure of electronic components. In this study, the experimental materials are pure Ag wire and Ag-2Pd alloy wire. First, the appropriate annealing conditions were selected by the microstructure and mechanical properties of wires before and after annealing, and then the microstructure and mechanical properties after EFO process were investigated. Ultimately, the as-received Ag wire and Ag-2Pd wire annealed at 275℃ were selected to bond with Al pad and then the DC current was applied in order to discuss the variations of bonding interfacial strength and IMCs growth. After as-received pure Ag and Ag-2Pd wires annealed at 275℃, 325℃, 375℃ for 30 minutes, the nano-hardness of pure Ag decreased to 0.3~0.37GPa, and that of Ag-2Pd decreased to 0.74~0.77GPa. Because the nano-hardness of annealing Ag wire was too low, the as-received Ag wire was used in the EFO process, while the Ag-2Pd wire annealed at 275℃ was selected. In this process, as-received Ag-2Pd wire was compared with Ag-2Pd wire annealed at 275℃ for their microstructure and mechanical properties. After EFO process, the FAB of Ag wire was columnar grains, while the Ag-2Pd wire was dendritic columnar grains. Compared with Ag-2Pd wire, there were more dendrites in the FAB of Ag-2Pd(275℃). Due to the heat effects after EFO process, the grains of Ag wire in HAZ were coarser than those of Ag-2Pd and Ag-2Pd(275℃) wires. About mechanical properties, the UTS, YS and EL of Ag-2Pd and Ag-2Pd(275℃) wires were higher than those of Ag wire after EFO process. About wire bonding process, before electrical current test, the average bonding strength of Ag-2Pd(275℃) wire (7.7gf) is stronger than that of Ag wire (6.9gf); after applying 0.4A DC current to the bonding interface for 0.5hr, 1hr and 2hr, the bonding strength of two wires decreased, and the lift-off on bonding interface of those wires didn’t occur because the electrical current induced a lot of heat into wires, the grains of wire grew up and formed into equal-diameter grains. Those equal-diameter grains caused the weakening of wires, so the fracture sites occurred on the wires. After applying 0.4A DC current to the bonding interface for 5hr, there were many cracks at the Ag-Al interface, but the Ag-2Pd(275℃) wire still had a good and flat bonding interface with Al pad; after electrical current test for 24hr, the lift-off occurred at Ag-Al interface, but the Ag-2Pd(275℃) wire still had a good bonding interface with Al pad.
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Chou, Yung-Jen, and 周勇任. "0.8 mil Au-Pd coated copper wire parameter optimization in BGA packaging wire bonding process." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/gy4juw.
Full textAbstract:
碩士國立彰化師範大學
機電工程學系
107
The semiconductor packaging and testing industry is developing principles with improved transmission efficiency, better heat dissipation, increased I/O count, volume miniaturization and lower cost with quality reliability. The improvement of process yield in the characteristics of product development principles is the continuous goal of each test and test factory. Wire Bonding is a bottleneck process in a ball grid array package (BGA). The parts that directly affect the quality of the work in wire bonding are raw materials (wafer, substrate, metal wire), parts (capillary), and wire bonding parameters. The JMP software's Taguchi experimental design method was used to analyze and obtain the optimal wire bonding parameters. The material was measured by the inter metallic compound, the tool microscope measuring sphere, the wire pull test, the ball shear test and the crater test. In this study, the total alarm rate of the optimum parameters was reduced from 0.57% to 0.11% compared with the control parameters, and the hourly output increased by 58.74 pcs from 54.50 pcs, and the product yield increased from 99.77% to 99.85%.
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Kuan-MingChu and 朱冠銘. "Electronic Flame-Off Mechanism and Wire Bonding Reliability of Fine Zn-Coated Al-Si Wires." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/refyx4.
Full textAbstract:
碩士國立成功大學
材料科學及工程學系
104
Aluminum wire is the common material of the wire bonding due to its resistance to oxidation and low price. It does not melt when becoming a free air ball (FAB) during the electronic flame-off (EFO) process with wettability, and is applied by wedge bonding. This study used 20 μm(0.8 mil) Zn-Coated Al-0.5wt.%Si (ZAS) wires to improve the shape of the FAB after the EFO process, while maintaining stability of the mechanical properties, such as the interface bonding strength and hardness. In order to test circuit stability after wire bonding, the current test was performed. During the experiment, it was found that 80 nm ZAS with wire bonding has lower resistance and higher fusing current. To verify the first bond reliability of ZAS80, the bonded samples with different fusing current were tested for 24 hours. The results showed that it still had good bond strength and there were no IMCs at the bonding interface. Besides, 175℃ aging and sulfide tests were used to understand the second bond reliability. It indicated that AS and ZAS80 would not be affected by the heat and sulfur. Accordingly, ZAS80 could be a promising candidate for wire bonding in the future.
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Hao-WenHsueh and 薛皓文. "Effect of Annealing Temperature on Recrystallization and Tensile Properties of Wire Bonding 23μm Silver Wires." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/20558853373144805511.
Full textAbstract:
碩士國立成功大學
材料科學及工程學系碩博士班
98
Silver is a novel wire material of wire bonding process because its excellent electrical and thermal properties, it’s more expensive than copper but cheaper than gold, and it’s lower hardness and hard to oxidative compared to copper. In this study, the effects of the microstrctures and tensile properties after annealing, EFO, wire bonding and electrical current test of the 23μm silver wire are studied. After the silver wires are annealed at 250℃ for 30minutes, the microhardness decreases to Hv 53±2 which is similar to gold and the tensile properties are steady because of recrystallization,. After the EFO process, there are 3~4 columnar grains in the FAB and HAZ in the wire whether the sample is annealed or not. According to the results of the microstructure and the microhardness, the lengths of HAZ in the as-drawn wire and annealed wire are 420μm and 220μm respectively. Due to the fact of forming HAZ, the strength is the lowest and strain concentration in this area, leading to the change of the tensile properties. In this study, I use two different Al subtrates, Al-bulk and Al-500nm thin film, as experiment’s bonding pads. Before the current test, the fracture of silver wire mainly occurs in the HAZ during the pull tests. After the current test, the fracture positions has shifted to the middle of new HAZ which is formed by the current test. Among the two substrates, Al-500nm thin film is more likely to fracture at the contact interface.
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Li, MING-CHIEH, and 李明傑. "Parameter Design of Wire Bonding MCP Process in Semiconductor Assembly." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/fw79r6.
Full textAbstract:
碩士國立雲林科技大學
工業工程與管理系
105
With the product requirements of thin and light characteristics for smart phones, tablet PCs and wearable devices, the multi-chip packaging technology was developed to reduce volume and capacity of products. In this study, the embedded Multi Chip Package (eMCP) products were chosen to investigate the key factors of the semiconductor multilayered package wire bond process with the cause effect diagram. The factors of USG Current, Bond Time, Bond Force and Temperature were used in the experiments of Taguchi Methods. The optimal parameter designs were determined to fulfill the quality requirements of a large gold-ball thrust value for the first solder joint and a large gold-wire tension value for the second solder joint. Results show that the wire bond temperature is not significant for the gold-ball thrust value and the gold-wire tension value. The key factors for the first solder joint are Bond Time and Bond Force. The gold-ball thrust value has increased 6.176% from the original 22.864g to 24.369g and the ball size has also increased 6.139% from the original 46.865um to 49.930um. The key factors for the second solder joint are USG Current and Bond Time. The average gold-wire tension has increased 7.447% from the original 4.024g to 4.351g.
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Hsiang-Chih, Chang. "Compensation and Design for Bonding-Wire at High Frequency Band." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2607200510295100.
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Chen, Ying-Chou, and 陳盈州. "Passive Component Wire Bonding Evaluation in a Hybrid IC Package." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/tuzk5n.
Full textAbstract:
碩士國立中山大學
機械與機電工程學系研究所
95
As the IC assembly technology fast developing in the modern electrical industries. Demand of high performance electric product is glowing up day by day. New generation of the hybrid IC assembly package has become the major role recently. In order to prevent the package defects occurring in end customer sites, in this paper we try to improve the IC assembly method by using a totally different process to fix the passive component on a BGA substrate. We found that the passive component can be proceeded the current gold wire bonding process. In case of the Hybrid BGA with the current passive component attaching process, we can find the thermal effect during the surface mount process. Since the solder can be melt every time during each heating process. Therefore, we plan to improve it without solder attachment. The new improvement is to fix the passive component by a non-conductive thermal cure glue. The glue can be done in one time cure, thus the further process would not influence the quality of passive component. However in the evaluation experiment, the component coated by Gold is the best choice, but we intend to just put it in a comparison model because of the cost consideration. Both works on passive component coated by Gold and Solder were proved. The customer support for the further study on the real products is suggested.
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HUNG, SHIH-CHIEH, and 洪士傑. "The development of high- heat-resistant aluminum alloy bonding wire." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/enmex7.
Full textAbstract:
碩士國立高雄應用科技大學
模具系碩士在職專班
104
Aluminum bonding wire is currently used as material for large-current semiconductors such as power devices. Recently, however, increased power density requirements for aerospace, automotive and deep well drilling applications mean that higher junction temperatures are to be encountered in power electronics. Wide band gap semiconductors like SiC and GaN can operate at much higher temperatures and are currently being introduced to applications, such as MOSFETs and IGBTs. There have been demands for development of high heat resistant materials as power devices have higher density, become more compact and have higher output, high purity aluminum bonding wire can contribute to improve heat resistance temperature of packages. In this study, the main research projects are development of high purity aluminum alloy bonding wire as the power module , this experiment selected 4N aluminum ingot, with iron , copper and other metals to enhance the strength and heat resistance , Al-Fe-Cu alloy ingot through appropriate deployment under , extruded , and other steps can be cold drawn wire diameter 0.378 mm, breaking load ≧ 900g, elongation ≧ 18%, electrical conductivity ≧ 62% IACS, and its composition is Fe: 0.7%, Cu: 0.1-0.2%, Al: bal. Keywords: semiconductor package, power module, heat-resistant aluminum bonding wire