Using Kr85 radioactive tracer techniques, initial sites of edge delaminations occurring during temperature cyclic tests in large-scale integrated circuit (LSI) plastic packages with either Cu alloy or alloy 42 leadframes are experimentally identified. Based on the experimental results, the processes of delamination growth and subsequent resin cracking are clarified. The effect of the length of the delaminations on the resin cracking is numerically analyzed on the basis of the linear fracture mechanics approach combined with finite element calculations. The directions of resin cracking predicted from the analysis are found to agree well with those of actual packages.

Issue Section:
Technical Papers
Keywords:
large scale integration, integrated circuit packaging, plastic packaging, delamination, fracture mechanics, encapsulation, finite element analysis
Topics:
Delamination, Fracture (Process), Resins, Temperature, Copper alloys, Fracture mechanics, Alloys, Radioactive tracers, Wedges, Cracking (Materials)
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