Voiding Control on AuSn preform reflow process| 5 April, 2006
I am working on a Substrate attach process. The package is gold plated, the preform is AuSn and the backing on the substrate is PdAg. I am using a Sikama reflow furnace. The profile has a 50 sec dwell time. I am over 280 degees C for a little over 1 min. The pick is at 342 degrees C. The packages are plasma cleaned and so are the preforms. The clip I am using is .250 Lb. I've tried to clean the preforms and the pkgs in 50% HCL for two min. It didn't work. I've tried to use a higher force clip. It didn't work. I've sent the pkgs out to a lab for contamination. There is no contamination. And I still get more voids than usual. Anyone has ever had this problem and what was the solution?