Thick-film multilayer technology

Thick-Film Multilayer. Thick-film multilayer technology has been used for many years to fabricate hybrid circuits that interconnect small-scale ICs or discrete components on a ceramic or metal substrate (67-70). This technology has also been used for multichip packaging of more highly integrated ICs for large computer applications. 

Equally important as tape casting in the fabrication of multilayer ceramics is thick film processing. Thick film technology is widely used in microelectronics for resistor networks, hybrid integrated circuitry, and discrete components, such as capacitors and inductors along with metallization of MLC capacitors and packages as mentioned above. 

Fig. 9. Monolithic multilayer ceramics (MMCs) derived from multilayer capacitor, high temperature cofire, and thick film technologies.

A refractive index change on the order of 10-2 could be induced in the polymer on irradiation with blue light. This technology can also be utilized in the fabrication of multilayer or thick films. By alternately coating urethane-urea copolymer with azobenzene and nonphotosensitive polyvinylalcohol multilayer films could be obtained. In this case, the bitmaps are recorded as images on individual layers. 

Thick-film circuits are single or multilayer structures produced by depositing a layer, or layers, of a specially formulated paste or ink onto a suitable substrate. Thick-film technology began in the early 1960s when DuPont introduced a thick-film resistor system for application in miniaturized circuits. IBM used thick-film materials in then-family of IBM/360 computers. Currently the worldwide market for thick-film circuits and devices is around 14 billion. Most thick-film circuits are still used in electronic applications such as in computers (Figure 27.14). 

Thick-film ceramic multilayer technology was chosen for this marine engine control module for its ability to handle high power dissipation and perform reliably in harsh envirorunents cycling between temperature extremes. Packaging density was also important to reduce the module size for direct mounting on the engine. 

A description of the application of ceramic and photopolymer technologies to achieve high-resolution electronic patterns follows. The first section discusses ceramic dielectric vias, and the second, conductive circuitry. Improved photosensitive ceramic coating compositions and more particularly, compositions that function as precursors to fired dielectric ceramics, are mainly useful in preparation of multilayer thick-film substrates. 

Capacitor dielectrics for ceramic circuits are available as tapes and pastes. The latter are used for plate capacitors on both the surface (e.g., standard thick-film technology) and within a multilayer structure. Electrodes are made... 

Muller, J., Thust, H., and Driie, K.-H., Laser structuring and trimming of RF-elements in multilayer thick film circuits. Proceedings of the International Conference on Electronics Technologies, Windsor, June 1994. 

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