Title :
Preparation, structure, and fracture modes of Pb-Sn and Pb-In terminated flip chips attached to gold-capped microsockets
Author :
Puttlitz, Karl J.
Author_Institution :
IBM Corp., Hopewell Junction, NY, USA
Abstract :
The author discusses the effects of selecting nickel, deposited from an electroless phosphorus-based bath, as the base metal to achieve solder wetting in solder-bump, flip-chip interconnection technology. Specifically discussed are the degrading effects on solder wetting due to precipitate formation during process thermal exposure and a method to prevent the problem. The role of a thick-gold overlay, referred to as a gold cap, in preventing degraded solder wetting is considered. Also addressed are the overall metallurgical characteristics of both lead-tin and lead-indium C-4 (controlled collapse chip connection) joints and their relation to performance (i.e. fracture mode and fatigue life)
Keywords :
electroless deposited coatings; flip-chip devices; gold; indium alloys; lead alloys; nickel alloys; phosphorus alloys; soldering; tin alloys; Au capped microsockets; C-4 joints; MLC; Ni base metal; Ni-P alloy deposition; Pb-In solders; Pb-Sn solders; PbIn-Au-Ni; PbSn-Au-Ni; controlled collapse chip connection; degraded solder wetting; degrading effects; fatigue life; flip chips; flip-chip interconnection technology; fracture mode; multilayered ceramic; overall metallurgical characteristics; performance; precipitate formation; process thermal exposure; solder bump flip chip interconnection; solder wetting; structure; Ceramics; Degradation; Fatigue; Flip chip; Gold; Lead; Nickel; Nonhomogeneous media; Rendering (computer graphics); Thermal expansion;
Conference_Titel :
Electronic Components and Technology Conference, 1990. ., 40th
Conference_Location :
Las Vegas, NV
DOI :
10.1109/ECTC.1990.122215
