RoHS Solder Paste

2/2/2017 1:07:19 PM

Hi, we're currently running a design with a fairly simple BGA. The problem we're running into is poor solderability (cold looking joints, high voiding in the BGA). All of this on a know good oven, with a known good thermal profile.

I'm guessing it's due to the mis-match in surface finish and process alloy. I used to run into a similar issue in a past life with defense and aero parts moving to RoHS while still needing to be processed with 63/37 paste, and I know how to overcome those issues. I've never had it the other way around.

Any pointers or ideas on how to get some workable PCBAs out of this debacle?

Thanks for any help guys!