Here is the abstract you requested from the IMAPS_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Removing Water Soluble Flux Residue under High Lead Flip Chip Die|
|Keywords: Flip Chip, Cleaning, High Lead|
|Faster processing speeds drive the demand for advance packages that improve response and performance. Area array packages are moving to larger die size with increased number of solder bumps under the die. Many Class II and III circuit assemblies, that integrate advanced packages on their board designs, remove flux residue from after the soldering operation. As the I/O and die size increase, the ability to penetrate, flow and dissolve flux residue under the die becomes increasingly difficult. The purpose of this designed experiment is to report data findings focused on improving the cleaning performance under High Lead Flip Chip die. Advanced packaging houses are using water soluble paste flux to attach high lead bumps to the substrate. The desired objective is to remove flux residue using high pressure spray impingement and hot DI-water. The problem is that the high reflow temperatures char the flux residue making the residues increasing difficult to clean. Engineered cleaning fluids, at low concentrations have been shown to improve cleaning efficacy under the die.|
|Mike Bixenman, CTO