ISSN:
0142-2421
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
External connections to thin film hybrid integrated circuits (HICs) by solder bonding have several advantages over those bonded by solid phase or thermocompression bonding. This paper reviews these advantages and discusses the parameters necessary for high strength, reliable solder joints to thin films. Dissolution of the soluble thin film(s) into solder limits the solder reflow times. Recent work has shown that dissolution rates of thin films in solder depend primarily on the degree of thin film heat treatment prior to soldering, substrate surface texture, and the method of thin film deposition. Auger in-depth profiling data show that alloy formation and internal oxidation reduces film dissolution during solder reflow. Metallographic sectioning and chemical analysis are used to identify weak solder bond interfaces which result from intermetallic formation. Tin from the solder diffuses rapidly and reacts with soluble metals such as gold, palladium and copper to form brittle intermetallics such as AuSn4, PdSn4 and Cu6Sn5. Intermetallic formation between the solder and the thin film systems of interest can affect joint strength and reliability.
Additional Material:
16 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/sia.740030108
