Abstract
Reliability of semiconductor packages significantly depend on the property of various materials used in the packages, since the packages are composed of a lot of components. Based on the stress analysis, the threshold values of elastic moduli and coefficients of thermal expansion of both a die bonding film and a liquid encapsulant were determined to achieve good connection reliability.
New polymer alloys, based on a low modulus polymer and an epoxy resin, were developed to meet the target values of modulus and CTE.
CSP fabricated with the newly developed materials showed excellent connection reliability and high temperature reflow resistance in lead free requirements.
