An application of MCM technology

With the emphasis on compactness in consumer electronic products, it is essential for electronic engineers to implement integrated systems. In this paper, an approach based on MCM technology, which implemented six discrete chips arranged in a single-package, is presented. This approach improved the integration of electronic system and met the demand of compactness in consumer electronic products. Among these discrete chips, two high-speed operational amplifiers with two chips of digital function were mounted on silicon substrate by using the silicon-on-silicon MCM technology, and the cheaper 3 μm metal gate CMOS technology was chosen to fabricate the silicon substrate. The Zeni EDA layout tool was used to design metal lines on the silicon substrate for interconnections between chips. Because the clock frequency of this system is above 100MHz, it is necessary to consider that the wire bonds, the package leads, the pins and the traces on silicon substrate can create signal-integrity problems, which prevent products from working correctly. The Agilent ADS momentum tool was used to simulate S-parameters of high frequency signal lines in silicon substrate, and the distance between the adjacent signals is optimized to minimize the coupling. Besides the design for interconnects, the heat transfer design of MCM package is also important. By using the Autotherm tool of Mentor Graphics´ PCB Boardstation products, the thermal distribution of this system was analyzed, and the result indicated that if the other two high power chips were also arranged on the silicon substrate, the whole system was destroyed. Therefore, they were directly mounted on the copper lead frame, which is useful for heat transfer. The practical application implies that multiple bare dice implemented in different technology can be packaged into a standard IC package and works well.