Thick-film multilayer technology application

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. 

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). 

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. 

Thin films of phthalocyanine compounds in general, and those prepared by the LB method in particular, display novel electrical properties (Baker, 1985). The LB technique for depositing mono- and multilayer coatings with well-controlled thickness and morphology offers excellent compatibility with microelectronic technology. Such films have recently been reviewed for their potential applications. The combination of LB supramolecular films with small dimensionally comparable... 

Critical issues associated with reflective or antirefiective coatings are the precise control of thickness and refractive index and, for multilayer films, development of a discrete, step-change in refractive index between layers. As reflected by the impressive production by Schott Glaswerke, the technology is sufficiently mature that these issues no longer constitute a barrier to the successful application of sol-gel technology. 

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