Electronics Forum | Fri Dec 08 11:08:03 EST 2000 | Antonio
Ok fellas, tell me how you'd fix this! I'm having melf connectors that are tombstoning in the wave, NOT the reflow, the wave. I've never seen this before. All other parameters are the same...solder, preheats, placements, the board, building humidi
Electronics Forum | Fri Dec 01 16:02:33 EST 2000 | Jim M
Thanks for your reply. I 've tried to clarify and answer your questions. The water soluble paste used is WS3060, type 4. The boards are sent through a inline di cleaner after reflow. There is a hot Di waterwash, rinse and then hot air to dry the wa
Electronics Forum | Thu Nov 30 13:51:33 EST 2000 | Michael Parker
Thanks for the details. Next question- where is your first time pass rate measured? Is this at test? Do you have inspection gates at the end of each process step? To get to the root cause, you need the earliest detection. Collect attribute data by a
Electronics Forum | Tue Nov 07 09:26:37 EST 2000 | Peter Barton
Adam, The most common cause for this problem is a variation in the plating thickness of the through holes, particularly if they are Sn/Pb solder levelled PCB's. Most pressfit connectors require a fairly tight control on the diameter of the holes to
Electronics Forum | Wed Nov 01 13:44:50 EST 2000 | Thomas Ballhausen
Using convection type reflow we observed following problem: One ball of a 313-PBGA appears to be dewetting. This happens randomly, i.e. no specific ball location, failure rate is rather low (3-4%), but since there are 12 PBGAs on one board the failu
Electronics Forum | Thu Oct 26 04:05:09 EDT 2000 | JohnW
George, where exactly is the diagreement ?, is it on the point if you should be doing the SPC on the paste or is it how the data is being interpreted ? The problem with SPC is every quality bod has another idea as to how it should be looked at, Xba
Electronics Forum | Fri Oct 27 09:06:19 EDT 2000 | Dave F
John Ooooo, leave it to me to miss THOSE customers!!! Darn, as you can see from my response, I was thinking ... well let's just leave it at that. YESSS, let's use as much capacity of the heavily loaded part of the shop and not use available capac
Electronics Forum | Wed Nov 01 12:19:42 EST 2000 | Fraser
Steve, someone somewhere is feeding you a line!! if you increase the draft angle from || to / \ on your laser cut stencil you increase the surface area of the side wall and hence increase the likelyhood of the paste sticking in the aperture. Whats m
Electronics Forum | Tue Oct 17 12:15:19 EDT 2000 | NLykus
Dave, Current process is Insert through hole components topside Dispense SMT glue Place SMT components bottom side Glue cure Insert 1 through hole component by hand Wave Wave temperature is 480oF Topside preheats in D.O.E ranged from 99oc to 108oC
Electronics Forum | Wed Oct 11 10:29:28 EDT 2000 | G. English
Try the following steps : FIRST CHECK THE ARCHIVE for further information, it WILL help you. Step One : What�s the chemical analysis of this white res? Obtain a sample. It could be tin, rosin, or something else??? Step Two : The fastest way I know
