Experimental and Mathematical Determination of Mechanical Strains within Plastic IC Packages and Their Effect on Devices During Environmental Tests

Abstract

Methods to quantify mechanical strains in plastic encapsulated devices (PEDs) are described. Calculations of strain-producing tendencies of encapsulants from material properties and processes are given. Measurements of die strain as a function of encapsulant, processing, and environmental exposure are presented. Possible mechanisms for gap formation between chip and encapsulant during autoclave tests are described.