Patent ID: 6746896
Filing Date: 2004-06-08
Classification: B23K,H01L

Abstract:
A wafer-level compressive-flow underfilling (WLCFU) process comprising the steps of:applying a WLCFU material onto a surface of a bumped wafer in an amount sufficient to ensure that the thickness of the solidified WLCFU layer is less than the height of the wafer bumps; solidifying the WLCFU material; separating the WLCFU material coated wafer into individual chips; covering the top of the bumps with a tacky film for promoting solder interconnects without intervening WLCFU material, wherein the tacky film and the WLCFU,material are not the same; mounting the WLCFU material and tacky film coated individual chips to substrates; and reflowing the solder bumps and curing the WLCFU material and tacky film simultaneously.