Low-cost large area processing using small area substrates - A novel multitiled palletization concept for MCM-D thin film process

Multichip module-deposited (MCM-D) has been the solution for integrated hig h density packaging due to its superior line resolution and higher inputs/o utputs (I/O) density compared to MCM-C and multichip module-laminate (MCM-L ) technologies, However, the consumer demand for high performance products at reduced costs is ever increasing, and this trend is expected to continue in the 21st Century, In order to find a low-cost solution for future MCM-D packaging, a novel palletization process which incorporates several tiles (alumina or silicon) on a large carrier glass (pallet) has been established in this study, The multitiling format provides simultaneous processing of several small tiles onto a re-usable CTE matched carrier glass. The tiles a re attached to the glass with a low modulus adhesive that can be released a t an elevated temperature (similar to 450 degreesC) The objective of this s tudy is to develop a multitiling process for a 300 mm x 300 mm area that is scalable up to 600 mm x 600 mm format. There are several challenges in rea lization of the large area palletization approach, such as formulation and qualification of a high temperature reworkable adhesive and minimization of out-of-plane warpage of the tiled assembly, Finite element models for warp age and its validation by Shadow Moire measurement, formulation of a compli ant adhesive for thermal stability up to 400 degreesC are reported in previ ous publications. This paper deals with 1) the validation of the palletizat ion concept on a 300 mm x 300 mm glass with weight restriction below 3 Ibs and thickness limitation to <6.25 mm, and 2) qualification of the formulate d adhesive through a correlative study on high temperature detachability of the attached tiles, chemical compatibility of the adhesive with acids, bas es, and less polar solvents, and interfacial shear strength at the lass/adh esive/tile joints. MCM-D thin film process on the tiled substrates is to be conducted by the member companies of the MCM-D Consortium.