Process induced warpage in multitiled alumina substrates for large area MCM-D processing

Electronics industries are responding to consumer demands in low-cost and h igh performance products for the 21st century. In order to find a low-cost solution for the future multichip module (MCM) packaging, a multitiling app roach through the incorporation of several tiles on a large carrier substra te has been established in this study. The multitiling format provides simu ltaneous processing of several small (95-mm x 135-mm) alumina tiles onto a carrier glass pallet with comparable coefficient of thermal expansion (CTE) , The objective of this study is to develop materials and processes for a 3 00-mm x 300-mm format that is scalable up to a 600 mm x 600 mm substrate. T he fabrication process begins with a carrier substrate on which tiles are a ttached using a low modulus adhesive. This composite structure is exposed t o high temperature thin film process that is required for the MCM-deposited (MCM-D) processing. The tiles are detached from the carrier substrate at a n elevated temperature (similar to 450 degrees C). The warpage of these str uctures is a critical factor that determines the processability of the thin films in a manufacturing environment. This paper discusses the warpage iss ues associated with various stages of processing of the proposed large area MCM-D structures.