A Fluxless and Low-Temperature Flip Chip Process Based on Insertion Technique

作者：Fendler Manuel^*; Davoine Cecile; Marion Francois; Saint Patrice Damien; Fortunier Roland; Ribot Herve

来源：IEEE Transactions on Components and Packaging Technologies, 2009, 32(1): 207-215.

DOI：10.1109/TCAPT.2008.2005099

• Fine pitch
• flip chip
• fluxless
• insertion
• interconnection
• large infrared detector array
• thermomechanical modeling

For heterogeneous materials assembly, the thermal expansion mismatch between the chip and the substrate is a roadblock for Hip chip bonding of ultrafine-pitch (<= 10 mu m) and large diagonal devices (>= 20 mm). Residual strains in bumps and device warpage have been calculated to evaluate the thermomechanical limits of a conventional flip chip soldering process using micro bumping. As a solution to overcome these limits, this paper describes a new patented flip-chip technology representing a technological breakthrough compared to conventional methods such as soldering or bonding through conductive adhesives. Electrical connections are performed by the insertion of metallic micro-tips in a ductile material. As a low-temperature process and fluxless technology, this method is adapted to fine-pitch and large devices. As a proof of concept, we present the bonding results obtained on fine-pitch large arrays of daisy chains with 500 x 500 contacts and 30-mu m pitch. The electrical contact has been demonstrated and characterized in terms of resistance and yield.

• 出版日期2009-3
• 单位中国地震局