Developments In Component Attach Adhesives

Polyimides, among the first adhesives used in the semiconductor industry, have a long history of reliability. Because of their sometimes troublesome handling and process requirements, and high cost, developments in epoxy technology have been made to produce lower cost, easier-to-handle epoxy adhesives which exhibit reliability approaching that of polyimides. Several generations of epoxies have been developed in response to external factors such as MIL-STD-883C Method 5011, changes in dispensing equipment technology, as well as industry demands for improvements in ionic cleanliness, cure speed, bondline stress absorption under large die, elevated temperature performance, and rheology more suitable for high-speed multi-orifice dispensing. Application specific problems such as dewetting separation, capacitor metal path formation, and resin bleed have produced a deeper understanding and control of these various phenomena. This paper summarizes these trends, and also cites specific examples of how various problems have been solved relevant to these technologies.