Investigations into the use of Adhesives For Level-1 Microelectronic Interconnections

In relation to other surface mounting methods for bare integrated circuits, Flipped Direct Chip Attachment (FDCA) provides the most compact level-1 interconnection. High performance adhesives represent an interesting alternative to solders and conductive pastes, which are now being used for FDCA interconnections. These materials may provide the ability to achieve higher interconnection density on a larger chip and at the same time provide encapsulation of the active face of the chip. They may also provide simpler and cleaner manufacturing processes, resulting in lower installed costs. The purpose of this paper is to describe recent findings that are relevant to the question of whether FDCA with adhesives is a viable concept. Experimental results are reported that provide a description of the characteristics of pressure engaged interconnections that were obtained using a proprietary structural adhesive system. In addition, results of a thermomechanical modeling study are reported that provide estimates of the thermal stress distribution in an FDCA adhesive bond.