摘要 |
The specification describes a technique for solder bump bonding IC chips or chip packages to interconnection substrates. Epoxy prepolymer underfill is applied to the surface of the interconnection substrate prior to the solder bump bonding step. The presence of the prepolymer underfill material does not interfere with effective bonding. This technique reduces substantially the potential for voids in the underfill layer that tend to occur when the underfill is applied to a bonded IC chip/substrate assembly. It also enables curing of the underfill polymer in the same heating step used to effect thermocompression bonding of the solder bumps.
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