Pre-tinning and Flux Considerations on the Reliability of Solder Surfaces
Source abstract
Abstract
The kinetics of wetting were studied on several different prepared surfaces of copper (Cu) to simulate the microstructure observed in pre-tinned Cu-clad printed circuit boards. The results illustrate the effectiveness of pre-tinning in maintaining the solderability of Cu surfaces. Pre-tinning with Pb-rich solder (95Pb-5Sn) is particularly effective since solderability is preserved even after a relatively long ageing treatment. On the other hand, pre-tinning with eutectic solder risks the loss of solderability during ageing or baking due to surface exposure of an ε-phase intermetallic with poor wetting properties. The results also confirm the presence of carbon in pre-tinned specimens due to the use of flux. The effect of carbon on solderability is not yet known.
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Research context
OpenAlex topics: Electronic Packaging and Soldering Technologies · 3D IC and TSV technologies · Aluminum Alloys Composites Properties
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Lawrence Livermore National Laboratory, Livermore, California, USA
Center for Advanced Materials, Lawrence Berkeley Laboratory, and Department of Materials Science, University of California, Berkeley, California, USA
Harry Diamond Laboratories, US Army, Adelphi, Maryland, USA
References (13)
Show source-provided references
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