Temperature dependent mechanical behavior of plastic packaging materials

This paper outlines sample preparation methodology and provides mechanical property data for commonly used plastic packaging materials. Included are die attach epoxies, mold compounds, liquid encapsulants (glob top material), printed circuit board laminate, and solder mask. Elastic modulus and thermal expansivity were characterized in the temperature range between -65/spl deg/C and 260/spl deg/C. Where possible, data were measured on samples cut from actual product to account for any microstructural effects that are process dependent. If special samples had to be fabricated, they were first subjected to the temperature profiles expected in actual manufacturing processes before being tested. The main effect of these added thermal exposures was to increase the glass transition temperature.