Title :
Am extended eutectic solder bump for FCOB
Author :
Greer, Stuart E.
Author_Institution :
Semicond. Products Sector, Motorola Inc., Austin, TX, USA
Abstract :
An evaporated, extended eutectic (E-3) bump structure has been defined. This positive standoff Pb/Sn solder bump builds on the evaporative structure used to produce C-4 interconnects but utilizes a thicker Sn cap to provide a low temperature, eutectic joining medium for flip chip on board (FCOB) applications. It has been shown that this new structure can be adapted to existing FCOB methodologies without altering the tools or processes being used today. By providing eutectic melting right on the bump itself, direct joining to organic assemblies is achieved without special processing at the board level. This leads directly to cost reductions and improved wirability at assembly. These options are illustrated. The characteristics of the bump have been evaluated and reliability data has demonstrated that this bump performs as well as or better than other solder interconnect structures. Extension of this joining technology to ceramics substrates has also been demonstrated
Keywords :
flip-chip devices; integrated circuit interconnections; integrated circuit packaging; integrated circuit reliability; reflow soldering; wiring; E-3 bump structure; FCOB; PbSn; direct joining; eutectic joining medium; extended eutectic solder bump; flip chip on board; interconnect structures; organic assemblies; positive standoff solder bump; reliability data; wirability; Ceramics; Cogeneration; Copper; Flip chip; Joining materials; Packaging; Temperature; Testing; Tin; Wiring;
Conference_Titel :
Electronic Components and Technology Conference, 1996. Proceedings., 46th
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-3286-5
DOI :
10.1109/ECTC.1996.551421
