Studies of composite catalysts of nickel on metal-ceramic substrates

1991 ◽  
Vol 43 (2) ◽  
pp. 545-552 ◽  
Author(s):  
L. L. Kuznetsova ◽  
V. N. Ananin ◽  
A. V. Pashis ◽  
V. V. Belyaev
1991 ◽  
Vol 43 (2) ◽  
pp. 553-558 ◽  
Author(s):  
L. L. Kuznetsova ◽  
V. I. Zaikovskii ◽  
A. V. Ziborov ◽  
L. M. Plyasova

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 116
Author(s):  
Malgorzata Lubas ◽  
Jaroslaw Jan Jasinski ◽  
Anna Zawada ◽  
Iwona Przerada

The metal–ceramic interface requires proper surface preparation of both metal and ceramic substrates. This process is complicated by the differences in chemical bonds and physicochemical properties that characterise the two materials. However, adequate bond strength at the interface and phase composition of the titanium-bioceramics system is essential for the durability of dental implants and improving the substrates’ functional properties. In this paper, the authors present the results of a study determining the effect of mechanical and chemical surface treatment (sandblasting and etching) on the strength and quality of the titanium-low-fusing dental porcelain bond. To evaluate the strength of the metal-ceramic interface, the authors performed mechanical tests (three-point bending) according to EN ISO 9693 standard, microscopic observations (SEM-EDS), and Raman spectroscopy studies. The results showed that depending on the chemical etching medium used, different bond strength values and failure mechanisms of the metal-ceramic system were observed. The analyzed samples met the requirements of EN ISO 9693 for metal-ceramic systems and received strength values above 25 MPa. Higher joint strength was obtained for the samples after sandblasting and chemical etching compared to the samples subjected only to sandblasting.


2016 ◽  
Vol 2016 (1) ◽  
pp. 000079-000086 ◽  
Author(s):  
Ho-Chieh (Jay) Yu ◽  
Jason Huang

Abstract In the high power module applications, the power increasing and the size shrinking becomes one of the major topics for the power module design. Due to both the power increasing and the size decreasing, the power density of the device will be much increased. Therefore, not only the thermal conductivity and stability of the substrate material but the long-term material reliability of the substrate have to be seriously considered. For these reasons, the ceramic PCB becomes one of the best solutions. The ceramic substrates now used are normally based on Ag-printed or direct bonding copper (DBC) technology. In the case of the Ag-printed ceramic substrate, the pattern resolution and metallization thickness are limited by the Ag-printed process. Also the combination strength of the silver and ceramic substrate by glass (which is normally mixed in the silver paste) is normally not good enough. A thermal dissipation barrier will then be formed between silver and ceramic substrate due to the poor thermal conductivity of the glass material. For the DBC ceramic substrate, DBC substrates are manufactured at 1065°C by the diffusion between ceramic and Cu/CuO layer. A thicker Cu layer thickness of normally more than 300 um is required in the thermal compressing bonding process. The Cu pattern resolution will then be limited by the thickness of the Cu layer. However, the about 5~10% of the voids exist randomly between ceramic and Cu layer is the other major issue. The resolution issues of the Ag-printed and DBC ceramic substrates make the limitation for the device density design (fine line/width and flip-chip device design become very difficult). The glass material in the Ag printed ceramic substrate and the 5~10% voids existence in DBC ceramic substrate may cause the reliability issue operating at a high power density applications. For high power density module applications, we introduce the DPC technology on the ceramic substrate. In DPC ceramic substrate system, the sputtered Ti is used as the combination material between Cu and ceramic substrate. And the first copper is then sputtered on the top of Ti layer as seed-layer for the following Cu electrode plating (second cupper layer). By the material and the sputtering process control, several ceramic substrate raw materials can be used, such as Al2O3, AlN, BeO, Si3N4 and so on. The Ti combined/buffer layer provides good adhesion strength and material stability. The second copper layer is plated by electrode casting plating to 3 to 5 oz. (100~150um) in thickness. The key technology of the metal trace plating is the material control of the sputter layers and the second copper layer stress release during plating. In the DPC system, the double layers design is available. The laser drilled via holes on the various ceramic substrates is introduced. The conducting of the front and back side is connected by the following plating process. The key technology of this process is the stability of the via-holes. We have to make sure the via-holes cleaning, impurity removing and material stability during high temperature laser drilled is well controlled. DPC ceramic substrates provide a better metal/ceramic interface uniformity and material reliability due to the stable Ti combination material and much less voids in the metal/ceramic interface. Also, the DPC ceramic substrates provide a gold pattern resolution of 50 um line space with tight tolerance of 20 um min. We believe the material characteristic make DPC a very suitable substrate material for high power module applications.


1988 ◽  
Vol 119 ◽  
Author(s):  
M. Bortz ◽  
F. S. Ohuchi

AbstractInterfacial reactions between either copper or titanium and cordierite-based (2MgO.2Al2O3.5SiO2) ceramic substrates are probed using X-ray Photoelectron Spectroscopy (XPS). Room temperature reactions are found to be strongly dependent on interfacial chemistry; while copper reacts weakly with the cordierite surface, titanium strongly reduces the Si-O and Al-O substrate bonds. Behavior during subsequent “in situ” annealing is dependent on substrate morphology. On amorphous cordierite films copper remains nonreactive while titanium dissociates remaining Si-O and Al-O bonds, forming a low valency Ti1+ oxide. On crystalline cordierite substrates copper diffuses rapidly upon annealing while titanium reduces substrate bonds forming a high valency Ti3+ oxide. Furthermore, thin 5Å Ti interlayers prevent copper diffusion at temperatures below 650°C. This study represents the first comprehensive treatment of the interfacial reactions in metal-multicomponent ceramic systems.


2016 ◽  
Vol 2016 (DPC) ◽  
pp. 001773-001790
Author(s):  
Ho-Chieh (Jay) Yu ◽  
Jason Huang

RESEARCH BACKGROUND: The now used ceramic substrate or sub-mounted are normally based on Ag-printed, direct bonding copper (DBC) ceramic or LTCC (Low temperature co-fired ceramic)/HTCC (High temperature co-fired ceramic) technology.Due to the limit of the screen-printed process, the resolution and conducting material thickness the Ag-printed, LTCC and HTCC substrate are poor. The poor resolutions make these materials difficult to use in high density and flip-chip device design. And the related thinner conducting material (normally <20um) limits the power rating of the design.DBC is now widely applied in power circuit design, however, duo to the copper lamination process requirement, more than 300um in thickness of copper layer is needed. Any lower copper thickness design should have an extra costly grind to reach. Also, the DBC material is difficult to provide to the multilayer trace design. OUR GOAL: We want to provide a solution with multilayer ceramic substrate for high power and high device density applications. Besides, the material properties, the adhesion of the metal/ceramic also be considered. Following are the material characteristics required for the development:A low electrical resistance material: Copper.A thick trace material thickness of more than 3 oz.A high thermal conductivity and stability ceramics with via-holes for TSV plating (Drilled Al2O3/AlN substrate ) or non- shrinking LTCC materialHigh metal trace resolution whose line width and space could be only 50 umWell metal/ceramic adhesion uniformity and strength is required: The voids between metal/ceramic < 1%; The adhesion strength> 2 kg/2*2mm2. METHODS & RESULTS: Metal trace plating: For high resolution and lower material electrical resistance request of the trace metal, we introduce electrical casting direct-plating copper (DPC) technology. The first copper is sputtered on the ceramic substrate using Ti as combined/buffer layer between copper and ceramic to provide good adhesion strength and stability. The second copper is made by electrical casting process to increase its thickness to 3 to 5 oz. (100~150um). The key technology of the metal trace plating is the material control of the sputter layers and the second copper layer stress release during plating. Multilayer Ceramic substrates: For double layers design, we use sintered Al2O3 or AlN substrates with electrical conducting via-holes design. The via-holes are made by laser drilling. And the conducting of the front and back side is connected by the following plating process. The key technology of this process is the stability of the via-holes. We have to make sure the via-holes cleaning, impurity removing and material variation during high temperature laser drilled is well controlled. For the more than three layers design, the non-shrinking LTCC is used. The dimension mismatch of the non-shrinking LTCC can controlled less than 100um., much better than that of normal LTCC/HTCC. By the correction of the following DPC process, the tolerance of the metal trace can be controlled < 30 um. The key technology of this process is the non-shrinking LTCC technology and the adhesion of the DPC metal on LTCC material.


2020 ◽  
Vol 69 (2) ◽  
pp. 20-25
Author(s):  
Thomas Utschig ◽  
Patrick Descher ◽  
Miriam Rauer ◽  
André Schwöbel ◽  
Daniel Schnee

Author(s):  
N. Merk ◽  
A. P. Tomsia ◽  
G. Thomas

A recent development of new ceramic materials for structural applications involves the joining of ceramic compounds to metals. Due to the wetting problem, an interlayer material (brazing alloy) is generally used to achieve the bonding. The nature of the interfaces between such dissimilar materials is the subject of intensive studies and is of utmost importance to obtain a controlled microstructure at the discontinuities to satisfy the demanding properties for engineering applications . The brazing alloy is generally ductile and hence, does not readily fracture. It must also wett the ceramic with similar thermal expansion coefficient to avoid large stresses at joints. In the present work we study mullite-molybdenum composites using a brazing alloy for the weldment.A scanning electron micrograph from the cross section of the joining sequence studied here is presented in Fig. 1.


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