MOISTURE SENSITIVITY OF HIGH PIN COUNT, HIGH PERFORMANCE PLASTIC QFP PACKAGES

摘要

With the increasing demand for faster and denser integrated circuit devices, the need for high performance packages for commercial applications increases. Electrically and thermally enhanced quad flats (ETE-QFP) were developed to address the market's need for cost effective, high pin count, high performance devices. ETE-QFP's combine printed circuit board technology and heat slugs to increase package performance. Because ETE-QFP's are made with plastic, they are susceptible to a phenomenon known as "popcorn" cracking during surface mount assembly. This paper presents a moisture study using scanning acoustic tomography (SAT) to evaluate the impact of mosture on ETE-QFP's during the surface mount process. Data for the critical moisture percentage causing cracking are presented along with recommendations for storage and handling.