High-Performance Polymers. Chemistry And Applications, Tome 3, Polyimides In Electronics

Since their discovery forty years ago, heat resistant polymers have been studied worldwide as substitutes for metal parts in the aerospace industry and as alternate materials in the fabrication, assembly and packaging of semiconductor components. The purpose of this book is to review the current status of high performance polymers, in particular polyimides, in the electronics industry. The main topics include an overview of the polymers that are used for optical lithography, semiconductor encapsulation, packaging, flexible circuitry and conformal coatings. The development of new polyimides that meet the stringent requirements of electronic devices and high density interconnect modules has been based on improved knowledge of the relationship between structure and properties. This aspect is examined for electrical and optical properties, adhesive strength, thermal expansion and mechanical stresses, as well as for moisture and solvent diffusion. A separate chapter is devoted to the chemistry of negative and positive photosensitive polyimides, because of the exceptional development of these polymers as buffer coatings and interlayer dielectrics. Attention is also paid to process parameters used for deposition techniques, cure cycles and etching methods. This includes a discussion of the analytical models developed to explain spin coating and planarization, both of which are important technical and reliability factors in the fabrication of multilevel interconnects. Polyimides are currently used as alignment layers in the manufacture of liquid crystal display devices. Consequently, this book provides in-depth information on electro-optical effects in liquid crystals, device construction, the chemistry of polyimide alignment films and techniques used to obtain homogeneously oriented liquid crystal molecules. Among the other applications of polyimides, the fabrication of multichip modules, polyimide waveguides, nonlinear optical components, microsensors and microactuators are reviewed in relation to polyimide chemistry and process flow. This is a general reference book for materials scientists, polymer chemists, manufacturers of electronic and optoelectronic devices, and process engineers. It is also a textbook for libraries of major chemical and semiconductor companies, research institutions, government laboratories and universities.