ABSTRACT
Electrically conductive adhesives (ECAs) are composites of polymeric matrices and electrically conductive fillers. Polymeric matrices have excellent dielectrical properties and thus are electrical insulators. The conductive fillers provide the electrical properties and the polymeric matrices provide the mechanical properties. Therefore, electrical and mechanical properties are provided by different components, which is different from metallic solders that provide both electrical and mechanical properties. ECAs have been with us for some time. Metal-filled thermoset polymers were first patented as electrically conductive adhesives in the 1950s [1-3]. Recently, ECA materials have been identified as one of the major alternatives for lead-containing solders in microelectronics packaging applications. There are two types of conductive adhesives: anisotropically conductive adhesives (ACAs) and isotropically conductive adhesives (ICAs). The utilization of both types of conductive adhesives as lead-free alternatives for flip chip, surface mount technology (SMT), chip scale package (CSP), and ball grid array (BGA) applications is reviewed in this chapter. For the purpose of completeness, the recent research work on nonconductive adhesives (NCAs) for these applications will also be covered in this chapter.
