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Journal articles
A Fluxless and Low-Temperature Flip Chip Process Based on Insertion Technique
Abstract : Abstract: 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.
https://hal-emse.ccsd.cnrs.fr/emse-00498450
Contributor : Anna Fraczkiewicz <>
Submitted on : Wednesday, July 7, 2010 - 2:55:22 PM
Last modification on : Wednesday, June 24, 2020 - 4:18:53 PM
Contributor : Anna Fraczkiewicz <>
Submitted on : Wednesday, July 7, 2010 - 2:55:22 PM
Last modification on : Wednesday, June 24, 2020 - 4:18:53 PM