Masters Abstracts (1996)

RAJAGOPALAN, SARATHY
(September 1996), Package Development Engineer, LSI Logic, Milpitas, CA

Email: srajagop@lsil.com

Solder Paste and Flux in Area Array Assembly

Solder paste and flux significantly impact the processes used to assemble area array components. These materials have an impact on process yields and product reliability. This research had two primary focuses, both of which encompassed the use of solder paste and flux in area array assembly. The first focus in this research was the comprehensive testing and evaluation of several solder pastes with respect to their use in ball grid array assembly. The unique characteristics that a solder paste should have for successful use in the BGA assembly process were identified. This thesis contains the testing and evaluation procedures used, the data and the results obtained for each paste for all the tests conducted, and the inferences made. The second focus was the characterization of the drum fluxer as a method of flux application for the DCA assembly process. Various factors which affect the transfer of flux onto the bumps of the DCA component were studied. Experiments were conducted to measure the surface tension of the fluxes at higher temperatures to predict the flow of flux during reflow.