All, Does anyone have any data on the relationship between solder balls (no clean flux w/ N2) and various solder masks? Some of our lines run OK and some do not for the same mask. The hard part to understand is that a mask will run poorly on one line and OK on another. My feeling is that the mask is statistically significant, but not necessarily the major contributor. All DOE have shown no sweet spot, but of course going to aqueous or eliminating N2 have shown positive results. The other variable that has completely eliminated solder balls is to shorten leads to ~.080". This went over poorly with the connector people. Any help would be appreciated. Steve Joy [log in to unmask]