Optimization of Thermomechanical Reliability of Board-Level Flip-Chip Packages Implemented With Organic or Silicon Substrates

A design that optimizes package-level along with board-level thermomechanical reliability of a flip-chip package implemented with an organic or a silicon substrate is provided for the package subjected to an accelerated thermal cycling test condition. Different control factors including thickness of substrate, die, board, and polyimide or soldermask are considered. The optimal design is obtained using an L₉ (3⁴) orthogonal array according to the Taguchi optimization method. Importance of each of these control factors is also ranked.