Building a domestic high density flip chip organic substrate capability: ITRI/SEMATECH chip carrier project

In 1996, SEMATECH, the US consortium for semiconductor R&D, and the Interconnection Technology Research Institute (ITRI), the US consortium for interconnection R&D, joined forces to address the need for sources of high density organic substrates for direct flip chip attach. These substrates are to be used to manufacture ball grid array (BGA) packages or multichip modules for high pin count (500 I/O and greater) flip chip die at a cost competitive with ceramic packages. The joint effort has progressed from technical discussions between the semiconductor manufacturers and the PWB fabricators, to the design, manufacture, and test of very high density BGA organic substrates. This paper reviews the problem being addressed and the goals and approach of the project. The designs of both the phase 1 test vehicle and the phase 2 test are described together with a discussion of the trade-offs and lessons learned. Results of the phase 1 build together with descriptions of the substrate technologies included are reviewed. Substrate flatness tests, moisture resistance tests and a series of environmental stress tests, including temperature cycling, pressure cooker, and 85°C/85% RH tests were performed on the test vehicles. The results of those tests are summarized. Finally, a description of the phase 2 plan and status is presented