Journal articles: 'Metalised ceramic'

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Ionescu, Ionuţ-Cornel, and Ecaterina Ionescu. "Surface microscopy study of metallic and ceramic orthodontic brackets." Romanian Journal of Stomatology 61, no. 1 (March 31, 2015): 20–24. http://dx.doi.org/10.37897/rjs.2015.1.3.

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An in-depth knowledge of the characteristics of the appliances with which we work is very important because it helps us to better understand the indications, contraindications, strengths and their possible shortcomings. The structural design elements play an important role in this context. One of the most commonly used methods for investigating them is represented by scanning electron microscopy. Using a scanning electron microscope we studied the aspects of the surface microstructure of metal and ceramic brackets. The results show that each of them has design features that help with the delivery of orthodontic forces. These characteristics differ drastically in shape from one type of bracket to the other, a square or diamond-shaped network in the case of metal brackets and an appearance of granules dispersed on the surface of the ceramic brackets.

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Siddiqui, Mohammad, and W. Kinzy Jones. "Resistance Brazing of Alumina Ceramic to Titanium Using Pure Gold." International Symposium on Microelectronics 2011, no. 1 (January 1, 2011): 000845–51. http://dx.doi.org/10.4071/isom-2011-wp6-posterpapers-paper1.

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Pure gold brazing of 96% alumina ceramic with CP titanium using electrical resistance heating has been analyzed. Wetting studies of gold with different refractory metals and titanium were performed. HTCC alumina ceramic was metalized with a 500 nm Nb layer yielding hermetic joints having leak rate of the order of 1.6 × 10−8 atm-cc/ sec. Adhesion strength was tested using nanoscratch testing using a nanoindentor on 100 nm Nb on polished alumina.

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Yeon, Jaebong, Michiru Yamamoto, Peiyuan Ni, Masashi Nakamoto, and Toshihiro Tanaka. "Joining of Metal to Ceramic Plate Using Super-Spread Wetting." Metals 10, no. 10 (October 15, 2020): 1377. http://dx.doi.org/10.3390/met10101377.

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Ceramic-metal composites with novel performance are desirable materials; however, differences in their properties result in difficulties in joining. In this study, the joining of metal to ceramic is investigated. We recently succeeded in causing super-spread wetting on the surface fine crevice structures of metal surfaces produced by both laser irradiation and reduction-sintering of oxide powders. In this work, joining copper onto an Al2O3 plate was achieved by taking advantage of super-spread wetting. Fe2O3 powder was first sintered under reducing conditions to produce a microstructure which can cause super-spread wetting of liquid metal on an Al2O3 plate. A powder-based surface fine crevice structure of metallic iron with high porosity was well-formed due to the bonding of the reduced metallic iron particles. This structure was joined on an Al2O3 plate with no cracking by the formation of an FeAl2O4 layer buffering the mismatch gap between the thermal expansion coefficients of iron and Al2O3. We successfully achieved metalizing of the Al2O3 surface with copper without interfacial cracks using super-spread wetting of liquid copper through the sintered metallic iron layer on the Al2O3 plate. Then, laser irradiation was conducted on the surface of the copper-metalized Al2O3 plate. A laser-irradiated surface fine crevice structure was successfully created on the copper-metalized Al2O3 plate. Moreover, it was confirmed that the super-spread wetting of liquid tin occurred on the laser-irradiated surface fine crevice structure, finally accomplishing the joining of a copper block and the copper-metalized Al2O3.

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Humayun, Ahmed, Yangyang Luo, Anusha Elumalai, and David K. Mills. "Differential antimicrobial and cellular response of electrolytically metalized halloysite nanotubes having different amounts of surface metallization." Materials Advances 1, no. 6 (2020): 1705–15. http://dx.doi.org/10.1039/d0ma00134a.

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Sememya, Roman, Artem Vilenskiy, and Sergey Chernyshev. "Design of RF filters with high selectivity on monolithic ceramic blocks." ITM Web of Conferences 30 (2019): 06001. http://dx.doi.org/10.1051/itmconf/20193006001.

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The paper presents the results of the development of quasielliptic filters on monolithic ceramic blocks. A circuit analysis of equivalent filter circuits is carried out using the coupling matrix method. A novel topology of a monolithic filter is being studied with the aim of obtaining increased frequency-selective properties due to the implementation of the attenuation poles. High cross-coupling values on ceramic monoliths with large inner metalized holes were obtained. The engineering method of adjusting the frequency position of the attenuation poles by trimming capacitive stubs is realized. Based on the performed analysis, as well as electromagnetic modeling, a monolithic ceramic filter was manufactured. The measurements results of the S-parameters for obtained models are presented.

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Kim, Dongjin, Shijo Nagao, Naoki Wakasugi, Yasuyuki Yamamoto, Aiji Suetake, Tetsu Takemasa, and Katsuaki Suganuma. "Power cycle tests of high temperature Ag sinter die-attach on metalized ceramic substrate by using micro-heater SiC chip." International Symposium on Microelectronics 2018, no. 1 (October 1, 2018): 000084–87. http://dx.doi.org/10.4071/2380-4505-2018.1.000084.

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Abstract Next generation power semiconductors, e.g. SiC and GaN, are emerging for the further minimization and high current/voltage of power devices with high reliability covering wider operating environments than those based on Si. To implement high reliability operation, the key technology is the control of the temperature distribution in the module, and thermal stress caused by the heat generated by power loss. In the present study, we have developed SiC micro-heater chip with temperature probe to evaluate thermal characteristics of an assembled system of Ag sinter die-attach on metalized ceramic substrate (Cu/Si3N4/Cu) during the repetitive power cycling. The test specimens were fixed on a water cooling system, and steady-state heat resistance of the system was measured during the power cycling. For comparison, Pb-Sn, Sn-Cu-Ni-P, Sn-Ag-Sb-Cu solders were used as die-attach material bonded on the same metalized ceramic substrates. The maximum applied power exceeds 200 W with cycles of 2 seconds of heating and 5 seconds of cooling, and the test cycles was over 5000 cycles. The power cycle number dependence on the temperature swing and thermal resistance characteristics would be discussed, in connected with the power cycle testing for real power devices.

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Lin, Jau-Jr, Cheng-I. Lin, Tune-Hune Kao, and Meng-Chi Huang. "Low-Temperature Metallization and Laser Trimming Process for Microwave Dielectric Ceramic Filters." Materials 14, no. 24 (December 8, 2021): 7519. http://dx.doi.org/10.3390/ma14247519.

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This paper describes a low-temperature metallization and laser trimming process for microwave dielectric ceramic filters. The ceramic was metalized by electroless copper plating at a temperature lower than those of conventional low-temperature co-fired ceramic (LTCC) and direct bond copper (DBC) methods. Compared with filters made via traditional silver paste sintering, the metal in the holes of the microwave dielectric filters is uniform, smooth, and does not cause clogging nor become detached. Further, the batches of fabricated filters do not require individual inspection, reducing energy, labor, cost, and time requirements. A microwave dielectric filter was then manufactured from the prepared ceramic using a laser trimming machine with a line width and position error within ±50 μm; this demonstrates a more accurately controlled line width than that offered by screen printing. After using HFSS software simulations for preliminary experiments, the microwave dielectric filter was tuned to a target Wi-Fi band of 5.15–5.33 GHz; the return loss was <−10 dB, and the insertion loss was >−3 dB. To implement the real-world process, the laser parameters were optimized. Laser trimming has a higher success rate than traditional manual trimming, and the microwave dielectric filter manufactured here verified the feasibility of this process.

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Nasiri, Ardalan, Simon S. Ang, Tom Cannon, Errol V. Porter, Kaoru Uema Porter, Caitlin Chapin, Ruiqi Chen, and Debbie G. Senesky. "High-Temperature Electronics Packaging for Simulated Venus Condition." Journal of Microelectronics and Electronic Packaging 17, no. 2 (April 1, 2020): 59–66. http://dx.doi.org/10.4071/imaps.1115241.

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Abstract An electronic packaging technology that survives the simulated Venusian surface temperature of 465°C and 96 bar pressure in carbon dioxide (CO2) and nitrogen environments, without the corrosive trace gases, was developed. Alumina ceramic substrates and gold conductors on alumina were evaluated for electrical and mechanical performance. The most promising die-attach materials are thick-film gold and alumina-based ceramic pastes. Alumina, sapphire, silicon, and silicon carbide dies were attached to the alumina substrates using these die-attach materials and exposed to 96 bar pressure in a CO2 environment at 465°C for 244 h. The ceramic die-attach material showed consistent shear strengths before and after the test. An alumina ceramic encapsulation material was also evaluated for thermomechanical stability. The devices on the packaging substrates were encapsulated by a ceramic encapsulation with no significant increase in cracks and voids after the Venusian simulator test. Wire pull strength tests were conducted on the gold bond wire to evaluate mechanical durability before and after the Venusian simulator exposure. The average gold bond wire pull strengths before and after exposure were 5.78 g-F and 4 g-F for 1-mil gold bond wires, respectively, meeting the minimum MIL-STD-885 2011.9 standard. The overall wire bond daisy chain resistance change was .47% after the Venus simulator test, indicating a promising wire bond integrity. A titanium package was fabricated to house the ceramic packaging substrate and a two-level metalized feedthrough was fabricated to provide electrical interfaces to the package.

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Purenovic, Jelena, V. V. Mitic, V. Paunovic, and M. Purenovic. "Microstructure characterization of porous microalloyed aluminium-silicate ceramics." Journal of Mining and Metallurgy, Section B: Metallurgy 47, no. 2 (2011): 157–69. http://dx.doi.org/10.2298/jmmb110331011p.

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Kaolinite and bentonite clay powders mixed with active additives, based on Mg(NO3)2 and Al(NO3)2, sintered at high temperatures produce very porous ceramics with microcrystalline and amorphous regions and highly developed metalized surfaces (mainly with magnesium surplus). Microstructure investigations have revealed non-uniform and highly porous structure with broad distribution of grain size, specifically shaped grains and high degree of agglomeration. The ceramics samples were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction analysis (XRD) and IR spectroscopy analysis, prior and after treatment in ?synthetic water?, i.e. in aqueous solution of arsenic-salt. Grain size distribution for untreated and treated samples was done with software SemAfore 4. It has shown great variety in size distribution of grains from clay powders to sintered samples.

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Roman, Patrick, Xudong Chen, W. Kinzy Jones, Ali Karbasi, C. Mike Newton, Travis Bates, Jacob Denkins, and Shekhar Bhansali. "Additive Manufacturing Design and Fabrication of Ceramic Cylindrical Ion Trap Mass Analyzer Chips for Miniaturized Mass Spectrometer Smart-Devices." International Symposium on Microelectronics 2015, no. 1 (October 1, 2015): 000197–202. http://dx.doi.org/10.4071/isom-2015-wa13.

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A chip based mass spectrometer technology promises to offer smart-device autonomous microsystem chemical analysis capability for sample determination and process monitoring for multiple applications in a small low power instrument package. This project focuses on the development of cylindrical ion trap mass analyzer chips fabricated using 3D Additive Manufacturing and planar Low Temperature Co-Fired Ceramic thick film processes toward the realization of a chip based mass spectrometer microsystem. The cylindrical ion trap (CIT) is a mass analyzer comprised of planar electrodes and operates by trapping and ejecting sample ions based on their mass in an RF field. Because of its simplicity CITs may be easily miniaturized and connected in tandem to achieve multiplexing. Additive manufacturing materials and methods enable enhanced trap miniaturization through micro machining and electrode patterning methods, fast and cost effective prototyping, batch fabrication, and material formulation flexibility. The current design incorporates three parallel ceramic plate metalized electrodes making up a singular trap geometry in a 10mm2 ceramic chip, forming a mass analyzer of reduced size, mass, and power, with enhanced material robustness for extended range use and in harsh environments. Unique processes have been developed to produce these devices which include conformal metallization layers, adhesion layers, ceramic paste formulations, sacrificial supporting materials, and co-firing methods. Additionally, 3D printing brings a unique design and fabrication capability enabling novel structures, material blending and heterogeneous integration. With true digital control, the designs are easily scalable and shape agnostic.

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Korevaar, G., A. Goossens, and J. Schoonman. "Synthesis of polycrystalline silicon films on metalized ceramic substrates with laser-assisted chemical vapor deposition." Le Journal de Physique IV 09, PR8 (September 1999): Pr8–757—Pr8–762. http://dx.doi.org/10.1051/jp4:1999895.

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Purenovic, J., V. V. Mitic, Lj Kocic, V. B. Pavlovic, V. Paunovic, and M. Purenovic. "Electrical properties and microstructure fractal analysis of magnesium-modified aluminium-silicate ceramics." Science of Sintering 43, no. 2 (2011): 193–204. http://dx.doi.org/10.2298/sos1102193p.

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The addition of Mg2(NO)3 and some active additives, composed of Al salts, to the mixtures of kaolinite and bentonite can provide clay compositions which, after sintering at high temperatures, produce very porous ceramics with microcrystalline and amorphous regions and highly developed metalized surfaces (mainly with magnesium surplus). Characterization of sintered samples was done before and after treatment in ?synthetic water?, i.e. in aqueous solution of arsenic-salt. Microstructure investigations have revealed non-uniform and highly porous structure with broad distribution of grain size, specifically shaped grains and high degree of agglomeration. Electrical characterization was estimated by determining dielectric constant and electrical resistivity in function of active additives amount and sintering temperature. Fractal analysis has included determination of grain contour fractal dimension.

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Smith, Lilla Safford, Gordon D. Hoople, Jim C. Cheng, and Albert P. Pisano. "A Resealable, Gas-Tight Packaging Technique for Silicon Microfluidic Devices." Journal of Microelectronics and Electronic Packaging 12, no. 1 (January 1, 2015): 49–54. http://dx.doi.org/10.4071/imaps.444.

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Recent efforts have led to the development of a silicon microfluidic cooling device known as the microcolumnated loop heat pipe (μCLHP). The μCLHP, like a traditional heat pipe, utilizes phase change of a liquid to rapidly draw heat away from a concentrated hot spot. Proper gas-tight packaging of this device is critical for the reliable testing of the recirculating fluid. This work presents a novel approach to filling and sealing the μCLHP. A miniature valve (Beswick M3SV-N) is bonded to the silicon fill ports of the μCLHP. The use of a resealable valve, as opposed to a permanent sealing method, allows the device to be filled, sealed, and then evacuated for testing with different fluids and at multiple pressures. Building on earlier work, the fill ports on the μCLHP were metalized with a Cr (10 nm)/Ni (200 nm)/Au (10 nm) stack. Then a lead-based solder was used to bond the stainless steel adapter to the metalized layers. Leak testing of devices sealed using these miniature valves demonstrated average hourly percent weight losses between 0.17% and 0.82%. While this bonding method has been developed specifically for the μCLHP, it is broadly applicable to most ceramic microfluidic devices, especially those fabricated from silicon and glass. Due to the time-intensive manufacturing process of microfluidic devices made from these hard materials, a novel, robust, resealing method that allows reuse of a single silicon microfluidic device for multiple test conditions is highly desirable.

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Roman, Patrick, Xudong Chen, W. Kinzy Jones, A. Karbasi, C. Mike Newton, Travis Bates, Jacob Denkins, and Shekhar Bhansali. "Additive Manufacturing Design and Fabrication of Ceramic Cylindrical Ion Trap Mass Analyzer Chips for Miniaturized Mass Spectrometer Smart-Device (Internet of Things) Applications." Journal of Microelectronics and Electronic Packaging 13, no. 3 (July 1, 2016): 113–20. http://dx.doi.org/10.4071/imaps.517.

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The current computing power and network capabilities of handheld smart devices is helping to drive the development of new sensors, enabling the Internet of things. A chip-based mass spectrometer technology promises to offer a smart-device autonomous microsystem chemical analysis capability for sample determination and process monitoring for multiple applications in a small low-power instrument package. This project focuses on the development of cylindrical ion trap (CIT) mass analyzer chips fabricated using three-dimensional (3-D) additive manufacturing (AM) and planar low temperature cofired ceramic thick film processes for a chip-based mass spectrometer microsystem. The CIT is a mass analyzer composed of planar electrodes and operates by trapping and ejecting sample ions based on their mass in a radiofrequency field. Because of its simplicity, CITs may be easily miniaturized and connected in tandem to achieve multiplexing. AM materials and methods enable enhanced trap miniaturization through micromachining and electrode patterning methods, fast and cost-effective prototyping, batch fabrication, and material formulation flexibility. The current design incorporates three parallel ceramic plate metalized electrodes making up a singular trap geometry in a 10-mm2 ceramic chip, forming a mass analyzer of reduced size, mass, and power, with enhanced material robustness for extended range use and in harsh environments. Unique processes have been developed to produce these devices which include conformal metallization layers, adhesion layers, ceramic paste formulations, sacrificial supporting materials, and cofiring methods. Additionally, 3-D printing brings a unique design and fabrication capability enabling novel structures, material blending, and heterogeneous integration. With true digital control, the designs are easily scalable and shape agnostic.

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Dumitru, Alina Iulia, Florentina Clicinschi, Tudor-Gabriel Dumitru, Delia Patroi, Jana Pintea, Georgeta Velciu, and Ildiko Peter. "Effects of Sintering Temperature on Structural and Electrical Properties of Fe3+ Doping PZT Ceramics." Acta Marisiensis. Seria Technologica 17, no. 2 (December 1, 2020): 4–7. http://dx.doi.org/10.2478/amset-2020-0012.

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AbstractThe influence of the sintering temperature on the structure and on the hysteresis loops of Fe3+ doped Pb(ZrxTi1-x)O3 system has been investigated. Three compositions have been selected in the following mode: one in rhombohedral region, one in MPB region and one in tetragonal region have been obtained by solid state reaction technique. Sintering has been carried out at 12000C and 12500C respectively. The nature of the phases has been investigated in detail using X-ray diffraction analysis (XRD). All the sintered samples reveal a perovskite type structure. The surfaces have been lapped and metalized in order to obtaine the hysteresis loops at room temperature. The results showed a similar behaviour with “hard” PZT ceramics.

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Smith, Lilla Safford, Gordon D. Hoople, Jim C. Cheng, and Albert P. Pisano. "A Resealable Hermetic Packaging Technique for Silicon Microfluidic Devices." International Symposium on Microelectronics 2014, no. 1 (October 1, 2014): 000516–21. http://dx.doi.org/10.4071/isom-wa53.

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Recent efforts have lead to the development of a silicon microfluidic cooling device known as the micro-Columnated Loop Heat Pipe (μCLHP) [1] [2] [3] . The μCLHP, like a traditional heat pipe, utilizes phase change of a liquid to rapidly draw heat away from a concentrated hot spot. Proper hermetic packaging of this device is critical for the reliable testing of the recirculating fluid. This work presents a novel approach to filling and hermetically sealing the μCLHP. A miniature valve (Beswick M3SV-N) is bonded to the silicon fill ports of the μCLHP. The use of a resealable valve, as opposed to a permanent sealing method, allows the device to be filled, sealed, and then evacuated for testing with different fluids and at multiple pressures. Building on work by Murphy [4], the fill ports on the μCLHP were metalized with a 10nm Cr - 200 nm Ni - 10 nm Au stack. Then a lead based solder was used to bond the stainless steel adapter to the metalized layers. Hermeticity testing of devices sealed using these miniature valves demonstrated average hourly percent weight losses between 0.170 % – 0.821 %. While this bonding method has been developed specifically for the μCLHP, it is broadly applicable to most ceramic microfluidic devices, especially those fabricated from silicon and glass. Due to the time intensive manufacturing process of microfluidic devices made from these hard materials, a novel, robust, resealing method that allows reuse of a single silicon microfluidic device for multiple test conditions is highly desirable.

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BIBBER, K. VAN, W. STÖFFL, P. L. ANTHONY, P. SIKIVIE, N. S. SULLIVAN, D. B. TANNER, V. ŽELEZNÝ, et al. "A NEXT-GENERATION CAVITY MICROWAVE EXPERIMENT TO SEARCH FOR DARK-MATTER AXIONS." International Journal of Modern Physics D 03, supp01 (January 1994): 33–42. http://dx.doi.org/10.1142/s0218271894000939.

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We propose a large-scale experimental search for dark-matter axions which may constitute an important fraction of our own galactic halo. As shown by Sikivie,1 dark-matter axions may be detected by their stimulated conversion into monochromatic microwave photons in a tunable high-Q cavity inside a strong magnetic field. The principal improvement in power sensitivity over two earlier pilot experiments (×25) derives from the large-volume high field superconducting magnet (the NASA SUMMA coils). The improvement in mass range (1.5 to 12.6 μeV) will result from the use of several microwave cavity arrays, of 2n cavities each, over the course of the experimental program, rather than a single cavity. We are participating in a joint venture with the Institute for Nuclear Research of the Russian Academy of Sciences to do R&D on metalized precision-formed ceramic microwave cavities for the axion search.

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Nasedkin, Andrey, and Mohamed Elsayed Nassar. "Effective properties of a porous inhomogeneously polarized by direction piezoceramic material with full metalized pore boundaries: Finite element analysis." Journal of Advanced Dielectrics 10, no. 05 (September 23, 2020): 2050018. http://dx.doi.org/10.1142/s2010135x20500186.

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This paper concerns the homogenization problems for porous piezocomposites with infinitely thin metalized pore surfaces. To determine the effective properties, we used the effective moduli method and the finite element approaches, realized in the ANSYS package. As a simple model of the representative volume, we applied a unit cell of porous piezoceramic material in the form of a cube with one spherical pore. We modeled metallization by introducing an additional layer of material with very large permittivity coefficients along the pore boundary. Then we simulated the nonuniform polarization field around the pore. For taking this effect into account, we previously solved the electrostatic problem for a porous dielectric material with the same geometric structure. From this problem, we obtained the polarization field in the porous piezomaterial; after that, we modified the material properties of the finite elements from dielectric to piezoelectric with element coordinate systems whose corresponding axes rotated along the polarization vectors. As a result, we obtained the porous unit cell of an inhomogeneously polarized piezoceramic matrix. From the solutions of these homogenization problems, we observed that the examined porous piezoceramics composite with metalized pore boundaries has more extensive effective transverse and shear piezomoduli, and effective dielectric constants compared to the conventional porous piezoceramics. The analysis also showed that the effect of the polarization field inhomogeneity is insignificant on the ordinary porous piezoceramics; however, it is more significant on the porous piezoceramics with metalized pore surfaces.

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Vayman, Dmitry, Ivan Krasny, Vyacheslav Danilov, and Svetlana Kumacheva. "Research into technological aspects of the three-dimentsional structures formation with metalized layers based on the LTCC ceramic." Proceedings of the Russian higher school Academy of sciences, no. 1 (March 17, 2017): 31–45. http://dx.doi.org/10.17212/1727-2769-2017-1-31-45.

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Hoseini, S. Muhammad H., S. Ali Hoseini, S. Abolfazl Hoseini, and H. Khorsand. "Dissimilar joining of SS 321 – Alumina ceramic via metalized brazing alloy and investigation on its metallurgical and microstructural properties." CIRP Journal of Manufacturing Science and Technology 37 (May 2022): 518–27. http://dx.doi.org/10.1016/j.cirpj.2022.03.002.

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Lang, F. Q., H. Yamaguchi, H. Nakagawa, and H. Sato. "Solid-State Interfacial Reaction between Eutectic Au−Ge Solder and Cu/Ni(P)/Au Metalized Ceramic Substrate and Its Suppression." Journal of Materials Science & Technology 31, no. 5 (May 2015): 445–52. http://dx.doi.org/10.1016/j.jmst.2014.10.010.

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Kareem, Aseel A. "Preparation and characterization of silver self-metallization on polyimide." Polymers and Polymer Composites 30 (January 2022): 096739112211016. http://dx.doi.org/10.1177/09673911221101698.

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In this work, silver (Ag) self-metallization on a polyimide (PI) film was prepared through autocatalytic plating. PI films were prepared through the solution casting method, followed by etching with potassium hydroxide (KOH) solution, sensitization with tin chloride (SnCl2), and the use of palladium chloride (PdCl2) to activate the surface of PI. Energy-dispersive X-ray analysis (EDX) showed the highest peak in the (Ag) region and confirmed the presence of AgNPs. The diffraction peaks at 2θ = 38.2°, 44.5°, 64.6°, and 78.2° represented the 111, 200, 220, and 311 planes of Ag, respectively. The FT–IR analysis for Ag-metalized PI showed that the =C-O-C= stretching absorption bands at 1735 cm−1 had no changes in position, only a significant difference in peak size at the deposition time increase. The formation of new bands (N–H stretching absorption band and N–C stretching band) assigned at 2325 and 955 cm−1 indicated strong coordination between N atoms and silver nanoparticles. The C–C stretching and = C–H plane vibration band at 1488 and 1117 cm−1 are shifted to 1413 and 1112 cm−1, indicating the silver nanoparticles' interaction with the polymer backbone. The thermal stability of PI- and Ag-metalized PI films at various deposition times (5, 10, and 15 min) was examined using thermogravimetric analysis (TGA). For PI, T0, T5, T10, and Tmax were observed to be 388°C, 402°C, 414°C, and 515°C, respectively. When the deposition time increased, the thermal stability increased. As a function of the deposition, the thickness and surface morphology of the copper layer on the PI films were characterized using scanning electron microscopy (SEM).

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O'Brien, D. J., D. M. Baechle, and E. D. Wetzel. "Design and performance of multifunctional structural composite capacitors." Journal of Composite Materials 45, no. 26 (October 17, 2011): 2797–809. http://dx.doi.org/10.1177/0021998311412207.

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Dielectric capacitors with mechanical load-bearing capability have been constructed by laminating glass-epoxy prepregs with metalized film electrodes. Mechanical characterization and high-voltage testing are used to quantify the elastic modulus, mechanical strength, and dielectric energy density of these structural devices. An approach for predicting mass savings in systems utilizing multifunctional material structures is also presented. The experimental results show that, in spite of increases in void content with fiber volume fraction, overall structural capacitor performance is greatest at maximum fiber volume fraction. At these high-fiber volume fractions, the overall multifunctional performance of the structural capacitors is predicted to provide mass and volume savings over conventional designs.

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Lang, Fengqun, Hiroshi Yamaguchi, Hiromichi Ohashi, and Hiroshi Sato. "Improvement in Joint Reliability of SiC Power Devices by a Diffusion Barrier Between Au-Ge Solder and Cu/Ni(P)-Metalized Ceramic Substrates." Journal of Electronic Materials 40, no. 7 (May 17, 2011): 1563–71. http://dx.doi.org/10.1007/s11664-011-1661-6.

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Eberstein, Markus, Marco Wenzel, Claudia Feller, Thomas Seuthe, and Frieder Gora. "Silver processing in thick film technology for power electronics." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (September 1, 2012): 000018–24. http://dx.doi.org/10.4071/cicmt-2012-ta13.

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Processing of Ag-equipped thick film modules is still challenging due to well-known issues of warpage of Ag-containing LTCC substrates or undesired coloring of Ag-surrounding ceramics. To increase the workability of Ag based thick film modules, enhanced control over these effects is necessary. From the experimental background as well as the chemical and thermodynamic nature of the element Ag, conclusions regarding essential properties during Ag-high temperature processing, like initial oxidation, transport via the vapor and glassy phase, and reduction are discussed. Taking into consideration a possible occurrences of this phenomenas as activated/deactivaed dependent on sintering conditions, explanation of unwanted maufacturing results like LTCC staining, warpage, glass thinning and setter memory effects are possible. From a technical standpoint, there are roughly two temperature ranges of relevance for processing silver metalized thick film structures. Between approximately 300 °C and 700 °C fast transport mechanisms of silver through the gaseous phase take place. Control can be achieved via governing the silver manufacturing, oxygen partial pressure, organic composition, powder conditioning and temperature-time schedule. Above approximately 600 °C, slower transport mechanisms of silver through the glassy phase and possible reduction of Ag(I) become evident. These effects originate corresponding impacts on the sintering kinetics. Here, control can be achieved via governing the glass composition, redox potential and, again, temperature-time schedule.

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Mallmann, E. J. J., A. S. B. Sombra, J. C. Goes, and P. B. A. Fechine. "Yttrium Iron Garnet: Properties and Applications Review." Solid State Phenomena 202 (May 2013): 65–96. http://dx.doi.org/10.4028/www.scientific.net/ssp.202.65.

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Due to a fast progress in the development of communication systems, the dielectric and magnetic ceramics (ferrites) have become attractive to be used in devices. Although the ferrites of the spinel type were the first material to be used in the microwave range, garnets have smaller dielectric losses and, therefore, are chosen for many applications. High demands for modern electric applications in magnetic materials results in new techniques and products being permanently studied and researched, with a consequent appearance of new solutions for a wide applications series. This work presents the study of the ferrimagnetic composite, constituted by Y3Fe5O12 (YIG) and Gd3Fe5O12 (GdIG) phases, through solid state synthetic route and submitted to high-energy mechanical milling. Additionally, experiments were made in order to evaluate the electric and magnetic behavior of the composites at radio frequency and microwave range and then later suggest an adequate technological application. The composites were efficient as ferrite resonator antennas (FRAs) and microstrip antennas (thick films deposited on metalized surface alumina substrate by screen-printing technique), in the microwave frequency range. The experiments with FRAs showed satisfactory results due to the control of the antennas radiation characteristics and their tuning by the use of an external magnetic field. The composite resonators studied in this work can be important to the development of a third generation (3G) wideband antennas to cell phones and other wireless products.

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Jackson, David. "CO2 SPRAY CLEANING AND OSEE NON-CONTACT INSPECTION FOR WIRE BOND PAD PREPARATION." International Symposium on Microelectronics 2014, no. 1 (October 1, 2014): 000307–12. http://dx.doi.org/10.4071/isom-tp47.

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Surface pad contamination is a major cause of poor performance for wire bonding operations. Examples of the wide range of contaminants that can degrade wire bond pull strength include, for example:Halogens and hydrocarbons: plasma etching, epoxy outgassing (dry processing), photoresist strippers, cleaning solvents.Contaminants from plating operations: thallium, brighteners, lead, iron, chromium, copper, nickel, hydrogen.Sulfur compounds: packing containers, ambient air, cardboard and paper, rubber bands.Miscellaneous organic contaminants: epoxy outgassing, photoresist, general ambient air (poor storage).Miscellaneous inorganic compounds: sodium, chromium, phosphorous, bismuth, cadmium, moisture, glass, vapor, nitride, carbon, silver, copper, tin.Human sources of contamination: skin particles, hair, sweat, spittle, mucus, cosmetics, hand lotions, facial make-up and fibers from clothing. As can be seen, there are many types of surface contaminations that may challenge a wire bonding operation, all of which must be removed to insure reliable and strong bonds. In this regard, conventional precision cleaning processes for high reliability surface pad preparation typically involve multiple steps, chemistries, and equipment to accomplish complete decontamination. Moreover, conventional cleaning methods are sometimes non-selective for the surface contaminants and substrates. For example, conventional vacuum plasma using Ar/O2 is typically used to clean bond pads. Vacuum plasmas are usually performed off-line, taking up to 30 minutes to complete, and are non-selective for the organic contamination. The entire organic substrate (i.e., PCB) is etched away during the plasma cleaning process to remove the bond pad contamination. During treatment, secondary organic surface contaminations (plasma treatment by-products from reacted substrate) are produced which can re-contaminate bonding surfaces. Advanced carbon dioxide (CO2) spray cleaning technology provides various methods for consistently preparing bond pads for critical wire bonding operations. A patented hybrid CO2 particle-plasma spray is presented in this paper that has demonstrated efficacy for selectively treating bond pad surfaces to remove a wide range of challenging surface contaminations. Moreover, a novel non-contact surface inspection technology called Optically Stimulated Electron Emission (OSEE) - developed to address surface cleaning and inspection issues that led to the 1986 Challenger Spacecraft explosion - is used to measure the effectiveness of the new CO2 surface cleaning processes. Statistically significant studies have been performed to determine the effectiveness of the selective CO2 particle-plasma surface treatment process for preparing bond pads for gold ribbon bonding operations. One such study compared and contrasted the performance of this new single-step CO2 surface treatment method with that of a conventional multi-step solvent-plasma method. The two treatment methods were used to prepare the surface of a metalized ceramic wafer that simulated bond pad surfaces and treatment areas representative of an actual high-reliability electronic board. The test results of this evaluation demonstrated that the CO2 particle-plasma surface treatment process is statistically similar to or sometimes better than a solvent-plasma hybrid cleaning process. CO2 spray cleaning was determined to be better for some types of contaminants as well – and in particular more relevant mixed-contaminant challenge tests. The CO2 cleaning process demonstrates a lower defect-per-million (DPM) level and an improved CpK. Finally, in this study OSEE surface quality analysis was performed before and after surface cleaning. OSEE analysis provided a reliable non-contact means of determining the proper level of surface pad preparation.

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Kessler, V., M. Dehnen, R. Chavez, M. Engenhorst, J. Stoetzel, N. Petermann, K. Hesse, et al. "Electrical Contact Resistance of Electroless Nickel to Nanocrystalline Silicon and the Fabrication of a Thermoelectric Generator." MRS Proceedings 1553 (2013). http://dx.doi.org/10.1557/opl.2013.863.

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ABSTRACTWe present the fabrication of a high-temperature stable thermoelectric generator based on nanocrystalline silicon. Highly doped silicon nanoparticles were sintered by a current activated sintering technique to get nanocrystalline bulk silicon. The metalization of silicon was realized by (electro-)chemical plating and the specific electrical contact resistance ρc of the semiconductor-metal interface was measured by a transfer length method. Values as low as $\rho _C < 1 \cdot 10^{ - 6} \,\Omega cm^2 $ were measured. The metalized nanocrystalline silicon legs were sintered to metalized ceramic substrates using a silver-based sinter paste. The device figure of merit of the thermoelectric generator was determined by a Harman measurement with a maximum ZT of approximately 0.13 at 600 °C.

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Hirao, Kiyoshi, You Zhou, Hideki Hyuga, Shijo Nagao, Katsuaki Suganuma, and Naoki Wakasugi. "Evaluation of thermal resistance for metalized ceramic substrates using a microheater chip." International Journal of Applied Ceramic Technology, July 10, 2021. http://dx.doi.org/10.1111/ijac.13819.

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Nasedkin, Andrey, and Mohamed Elsayed Nassar. "Numerical investigation of the effects of partial metallization at the pore surface on the effective properties of a porous piezoceramic composite." Journal of Advanced Dielectrics, August 25, 2021, 2160009. http://dx.doi.org/10.1142/s2010135x21600092.

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This paper presents a numerical homogenization analysis of a porous piezoelectric composite with a partially metalized pore surface. The metal layers can be added to the pore surfaces to improve the mechanical and electromechanical properties of ordinary porous piezocomposites. Physically, constructing that composite with completely metalized pore surfaces is a challenging process, and imperfect metallization is more expected. Here, we investigate the effects of possible incomplete metallization of pore surfaces on the composite’s equivalent properties. We applied the effective moduli theory, which was developed for the piezoelectric medium based on the Hill–Mandel principle, and the finite element method to compute the effective moduli of the considered composites. Using specific algorithms and programs in the ANSYS APDL programming language, we constructed the representative unit cell element models and performed various computational experiments. Due to the presence of metal inclusion, we found that the dielectric and piezoelectric properties of the considered composites differ dramatically from the corresponding properties of the ordinary porous piezocomposites. The results of this work showed that piezocomposites with partially metallized pore surfaces can have a higher anisotropy, compared to the pure piezoceramic matrix, due to the defects in metal coatings.

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Zhang, Yukun, Jinsong Zhang, and Jichun Chen. "Effect of interfacial microstructure evolution on the peeling strength and fracture of AMB Cu‐metalized AlN substrate." Journal of the American Ceramic Society, September 6, 2021. http://dx.doi.org/10.1111/jace.18092.

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Journal articles on the topic 'Metalised ceramic'

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