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contributor authorCaroline S. Lee
contributor authorDoug C. Crafts
contributor authorT. W. Eagar
date accessioned2017-05-08T23:46:52Z
date available2017-05-08T23:46:52Z
date copyrightDecember, 1995
date issued1995
identifier issn1528-9044
identifier otherJEPAE4-26151#281_1.pdf
identifier urihttp://yetl.yabesh.ir/yetl/handle/yetl/115127
description abstractThe Pb/Sn electroplating process for C4 technology requires the ability to etch Ball Limiting Metallurgy (BLM) in the presence of the Pb/Sn bumps. Upon etching, a surface corrosion layer is formed and an appropriate cleaning acid must be used to remove this layer prior to solder reflow of the bumps. It was found that the morphology of the surface layer formed upon etching on the Pb/Sn solder bumps is critically dependent on the concentration of the etchant. Using a gravimetric test, XPS and AES analysis, PbO containing small amounts of Sn and S, was identified to be the primary component of the surface. The thickness morphology, composition and the growth rate of the layer are critically dependent on the sulfur from the etchant. In H2 O2 -rich solutions, the surface appears to be loosely packed and the growth rate on the surface of the bump was found to be reaction-rate limited; whereas, in H2 SO4 -rich solutions, the diffusion rate is the controlling step informing the surface layer on the solder bumps, thus producing a thin and dense layer.
publisherThe American Society of Mechanical Engineers (ASME)
titleCleaning and Reflow of Pb-Sn C4 Solder Bumps
typeJournal Paper
journal volume117
journal issue4
journal titleJournal of Electronic Packaging
identifier doi10.1115/1.2792106
journal fristpage281
journal lastpage287
identifier eissn1043-7398
keywordsSolders
keywordsEtching
keywordsReflow soldering
keywordsSulfur
keywordsThickness
keywordsElectroplating
keywordsCorrosion
keywordsDiffusion (Physics) AND Metallurgy
treeJournal of Electronic Packaging:;1995:;volume( 117 ):;issue: 004
contenttypeFulltext


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