An overview of elastomeric conductive polymer interconnection materials and their use in MCM technology

A family of anisotropically conducting metal-filled polymer composites that are representative of ACPF (anisotropically conducting polymer film) has been developed. These composites are collectively referred to as elastomeric conductive polymer interconnection (ECPI) materials. The ECPI materials are metal-polymer composites with conduction isolated to the thin (or Z) direction, as are all ACPF materials. These materials offer unique advantages over more conventional technologies used for module attachment, high density connectors, socketing, and device testing. ECPI materials are well suited to interconnecting pad-grid arrays and, because of their electrical properties and mechanical compliance, they can accommodate short-range surface variations of several mils and transmit high-frequency signals without distortion, and their through-contact resistance is low. In general, ECPI needs only the application of pressure to give interconnection, but a group of design criteria was developed to assure optimal performance. The ECPI structure is discussed, the electrical and mechanical properties of typical ECPI interconnections are described, and design guidelines for using ECPI in connector and testing applications are summarized