Multilayer ceramics development

W. A. Vitriol andj. I. Steiaberg, "Development of a Low Fire Cofired Multilayer Ceramic Technology," 1983, pp. 593—598. 

The most significant commercial product is barium titanate, BaTiO, used to produce the ceramic capacitors found in almost all electronic products. As electronic circuitry has been rniniaturized, demand has increased for capacitors that can store a high amount of charge in a relatively small volume. This demand led to the development of highly efficient multilayer ceramic capacitors. In these devices, several layers of ceramic, from 25—50 ]lni in thickness, are separated by even thinner layers of electrode metal. Each layer must be dense, free of pin-holes and flaws, and ideally consist of several uniform grains of fired ceramic. Manufacturers are trying to reduce the layer thickness to 10—12 ]lni. Conventionally prepared ceramic powders cannot meet the rigorous demands of these appHcations, therefore an emphasis has been placed on production of advanced powders by hydrothermal synthesis and other methods. 

Since the first multilayer ceramic capacitor (MLCC) was introduced in the early part of World War II there have been two principal development trends. One is towards smaller sizes and higher capacitance values, that is towards maximizing volumetric efficiency, and the other is cost reduction. These developments have had to be accompanied by improved reliability, which assumes increasing relevance as the number of capacitors in a given piece of equipment, for example a PC or mobile phone, steadily increases. 

Next to tubes and fibers, tbin ceramic sheets are also a very interesting subject for the development of thermoplastic ceramic extrusion systems. It has been shown that it is feasible to produce ceramic sheets and films with thicknesses under 200 pm. Figure 8 shows a picture of a ceramic sheet made of silicon dioxide nanoparticles. This technique could, for example, be used for the fabrication of multilayer ceramic bodies (e.g. multilayer capacitors, structural laminates) which currently are produced using the tape casting process. Big advantages relative to this conventional process would be the recycleability of the thermoplastic feedstocks and the higher achievable powder loading. 

Development work at RCA on multilayered ceramics using tape-cast material. 

The original multilayered ceramic packages were developed around what is today known as a high-temperature cofired ceramic (HTCC). In this technology the ceramic was primarily an alumina-based... 

Terashi, Y. (2000). Development of material for multilayer ceramic substrate with copper wiring in millimeter wave application, Proceedings of lEMT/IMC Symposium , pp. 382-383. Hamano, S. (3999). Glass ceramic package for mobile communication applications, Proceedings of lEMT/IMC Symposium , pp. 113-119. 

The development of multilayer ceramics was first demonstrated in the preparation of capacitors in the late 1940s [1]. Over the following 10 years, the techniques necessary to produce multilayer high-temperature cofired ceramics (HTCC) substrates [2] were developed at American Lava and RCA, culminating in the first comprehensive description of this technology in 1961... 

For example, the development of high-mesh-coimt screens and microvias in multilayer ceramics has recently allowed for much higher densities of interconnects than was traditionally the case [52-54]. These same technologies also enable the tight tolerance fine lines that are required by high-frequency designers [53-55]. Finally, there has been tremendous activity in the last few years regarding the use of microfluidic and MEMS-based devices based on multilayer ceramic materials [57,58]. 

William A. Vitriol and Jerry 1. Steinberg, Development of a low temperature cofired multilayer ceramic technology, ISHM Proceedings, 1983, pp. 593-598. 

Shimoda H., Ishitobi N., Kawamima K. and Kobayashi M. Development of a High-Q Multilayer Ceramic Resonator, J. Appl Phys., (1992), 31,3160-3163. 

Current and Future Developments in Multilayer Electronic Ceramics... 

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