Study on Package Strength of uMCP (Multichip Package) for Mobile Application through Three-Point Bending Test and Simulation

Abstract

Package strength becomes challenging and issue for thin package used in mobile application. Package with low strength may result in package failure such as inside die cracking or package cracking through epoxy mold compound (EMC) when package is subjected to external loading from assembly process or field application. Package design and strength assessment methodology are essential for robust package used in mobile application. In this study, uMCP package is selected to demonstrate package strength investigation and improvement. Three-point bend (3PB) testing approach and finite element analysis (FEA) method are adopted for package strength study. A strain-controlled methodology is developed for package strength assessment. FEA simulation results show that mold cap thickness and mold clearance are 2 key factors for package strength. Die strength is another key factor for robust package strength design. In addition, effect of EMC material on package strength is also investigated.