ABSTRACT
This chapter focuses on the properties of the base materials and how they function in an electronic assembly. The importance of material selection and the use of appropriate manufacturing processes to gain the optimum use of these materials cannot be overemphasized. Ceramic (alumina) substrates are polycrystalline aluminum oxide with traces of metal oxide glasses that are added to enhance the physical properties of the material. Most hybrid circuit requirements are satisfied by the properties of the 96% alumina. Aluminum oxide is widely available and relatively inexpensive. It is highly compatible with most semiconductor and interconnection materials. Beryllia, or beryllium oxide, is also a very popular construction material for electronic substrates. Ceramic substrate technology has been practiced for many years and has served the electronics industry well.
