New elevated temperature mold compound adhesion test method using a dynamic mechanical analyzer

This paper outlines the development and application of a testing technique for measuring the adhesion strength of a mold compound to leadframe material, that utilizes a dynamic mechanical analyzer in the film tension mode. This technique allows for the utilization of standard transfer molding processes and equipment coupled with a standard electronic device configuration. The technique allows for rapid heating and equilibration of the sample to the test temperatures and the accurate determination of the yield tensile shear force associated to the adhesion failure of the mold compound leadframe interface. The data that will be presented highlights the profound effects that device conditioning, mold compound chemistry, and leadframe composition have on the adhesion properties of these interfaces. It will be shown that the sensitivity of this technique can differentiate adhesion performance relating to effects of conditioning, mold compound chemistries, and leadframe material selection. The resulting data will be used for correlation to other analytical techniques for proper materials selection, and as criteria for FEA modeling verification to improve the predictive performance of materials and processing.