Material development of polymer/metal paste for flip-chip attach interconnection technology

Upon completion of the second year of this contract, we have delivered the next generation of polymer/metal composite, optimum paste H, to Endicott. We have done preliminary flip-chip type bonding at Universal Instruments, working closely with their personnel to enhance their equipment set and process. We have also shown that a PMC bond can withstand over 40% strain without effecting its electrical and mechanical properties. This resilience of the conductive polymer paste both under electrical and mechanical behavior, is a strong indication of the applicability of the material for Flip Chip Attach to organic laminates. We have also confirmed during this phase of the Contract that the Optimum Paste H can be processed and applied under normal ambient conditions, without special precautions of low temperature or inert atmospheres, a property which sets our system apart from many other commercial pastes. We would also like to remark the achievement of optimized paste properties and how these properties address the mayor issues and requirements for flip attach applications, in Table I and II of this report. Use of the PMC to build interposer for chip-testing. Due to the high electrical conductivity of the PMC, a process was developed to use a thin film layer of the paste applied to a metal cathode of an electrochemical cell, to build fully metallized thru hole arrays containing a given C-4 chip foot print. This array interposers can be used for chip test (known-good-chip) applications. This process will be described in detail at the Year-End Review Meeting in Binghanton