Small, lightweight and thin package (TQON)

Mobile electronic equipment, such as cellular products, are required to be small sized, lightweight and have high-performance. However, no-lead semiconductor packages that have peripheral terminals are difficult to reduce in package size in the low pin count area. TQON (thin quad outline non-leaded) packages, manufactured using a flip chip process, can solve this problem. This paper reports the newly developed TQON, miniaturized and designed for high 2nd level reliability. The Japanese cellular market requires high reliability. The issue of most concern is 2nd level (solder joint) reliability. The package is evaluated by thermal cycle testing (TCT), bend testing and drop testing etc. At first, failures occurred in TCT on board at 300 cycles. The structure and material of TQON was improved by DOE (design of experiment). It was found that the main effecting factors were underfill size and molding material properties. The optimization of the package structure could realize high quality package TQONs.