Raymond A. Jackson

Ceramic mini-ball grid array package for high speed device

We have developed a Ceramic Mini Ball Grid Array (BGA) package for a high speed switch chip (200 MHz) application. In this paper, we describe the 0.5 mm pitch mini BGA package and the processes developed to fabricate this package. In addition, a matching ceramic socket that was developed to test the high speed switch chips is also briefly reviewed. The mini-BGA process enabled the packaging of the switch chip in a 21 mm ceramic substrate with 1521 solder ball connections. The main difference between the mini solder ball connections described here and conventional ceramic ball grid array (CBGA) packages is that 60/40 Pb/Sn eutectic solder is used in the mini-BGA package compared to 90/10 Pb/Sn solder balls used in CBGA packages.

Low-cost, high reliability flip-chip removal for multi-chip modules

The prevalent trend to consolidate devices onto multi-chip modules due to electrical performance benefits and printed circuit board real-estate constraints drives the need to have a device replacement technology. The ability to remove and replace devices, for either defective conditions or upgrade level designs, while preserving the electrical integrity and reliability of the other components on the module at various stages of manufacture is essential. It is not a cost-effective option to discard the remaining expensive die or to scrap the fully assembled complex module. The process must also be able to be exercised easily in a development environment where resources are at a minimum, but the learning generated through the ability to perform such operations in-situ is imperative. With the emergence of OEM assembly vendors, this technique and process must also be simple, inexpensive and easy to use, as a company should not be required to invest large resources in remove and replace manufacturing operations.