With their tight pitch and delicate solder balls, testing micro BGA packages presents a complex design challenge. Texas Instruments (TI) has developed a contact design that minimizes solder ball damage and boosts yield.
This approach employs a "pinch" or dual–beam style contact that interfaces the sides of each solder ball at multiple points. Excessive disruption of the package solder ball geometry, on the bottom surface, can lead to assembly and reliability problems farther down the line. By interfacing the non critical sides of each solder ball and incorporating a superior contact design, the socket ensures electrical continuity, minimizes ball deformation, and eliminates potential manufacturing and reliability problems in the end package.
Since TI's burn–in test is cost–effective and available in high volume, manufacturers no longer have to rely on random testing to ensure quality. This non destructive test allows all Micro BGA packages to be tested.
Micro BGA is one of the most dynamic chip scale concepts to date. Its potential is particularly important in the flash memory market, where the demand for increasingly small form–factor packages makes the incumbent TSOP packages prohibitive.