Moisture sensitivity and reliability of plastic thermally enhanced QFP packages

Standard plastic quad flat packs have difficulty meeting the thermal performance requirements of devices with high power dissipation. The development of plastic thermally enhanced quad flat packs (TEQFP), which incorporate heat slugs or heat spreaders in the leadframes, provide a cost effective solution. Because the final packages are of molded plastic, TEQFP´s are susceptible to moisture-induced cracking and other plastic reliability problems. This paper discusses the impact of moisture on package cracking during the board mounting process and the overall reliability of TEQFP´s. Based on our study using scanning acoustic tomography and reliability stress tests, our findings reveal that TEQFP´s have comparable reliability to standard PQFP´s if proper storage and drying guidelines are followed