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

Electronics industries are responding to consumer demands in low-cost and high performance products for the 21st century. In order to find a low-cost solution for the future multichip module (MCM) packaging, a multitiling approach through the incorporation of several tiles on a large carrier substrate has been established in this study. The multitiling format provides simultaneous 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 300-mm x 300-mm format that is scalable up to a 600 mm x 600 mm substrate. The fabrication process begins with a carrier substrate on which tiles are attached using a low modulus adhesive. This composite structure is exposed to high temperature thin film process that is required for the MCM-deposited (MCM-D) processing. The tiles are detached from the carrier substrate at an elevated temperature (similar to 450 degrees C). The warpage of these structures is a critical factor that determines the processability of the thin films in a manufacturing environment. This paper discusses the warpage issues associated with various stages of processing of the proposed large area MCM-D structures.