Novel Underfills: Effect of the Filer for Fast-Flow Underfills and Latent Catalyst For No-Flow Underfills on the Processing of Flip-Chip Devices

摘要

Underfill encapsulant is critical to the reliability of the flip-chip solder joint interconnects. Two underfilling techniques presently used are the "Fast-Flow" and "No-Flow" processes. A key factor in the processing of flip-chip devices using the "Fast-Flow" underfill technique is the flow rate. The flow rate is mainly affected by the filler loading, particle size, and particles size distribution. A key factor in the processing of flip-chip devices using the "No-Flow" underfill technique is the selection of the latent catalyst. In the underfill formulation, this catalyst should give a minimal curing reaction before and a rapid curing reaction shortly after the solder joint reflow. In this paper, we present the preliminary experimental results of the above factors on underfill materials.