Electronics Forum | Wed Aug 27 13:15:50 EDT 2008 | vladig
Well, it's difficult to play with the profile without knowing the root cause for the problem. A simple cross-section can tell you whether the component is at fault or not. If it doesn't point out to the root cause then and SEM/EDS analysis on one of
Electronics Forum | Sun Sep 28 17:14:53 EDT 2008 | ronsou
small pads like 0402 tend to get hot quite > easily. looks like excessive heat is your problem > here. pads are wetted, component leads are not. > this means solder paste flux on top layer was > exhausted before entering in reflow. your profile
Electronics Forum | Thu Aug 28 18:48:49 EDT 2008 | markhoch
You're using a SAC305 chemistry? Double check your liquidus temp! Your profile shows a liquidus temp of 217 degrees C. SAC305 is not eutectic. (It doesn't transition from paste to liquid instantly). It goes thru a "pasty" stage. We use a temp of 221
Electronics Forum | Thu Aug 28 21:43:23 EDT 2008 | davef
Couple of points: * We'll tell ya, although it's tough to tell from these pix, but it does not look like dewetting. It looks like nonwetting. * We don't think you're getting this product hot enough. We don't know where you measured the profile you po
Electronics Forum | Sun Oct 19 15:02:10 EDT 2008 | Jdt13
We are having some issues with a RF PCB aprox 1" x 1". The pads are in the bottom of the PCB and it goes on the Top side of the mother board the pads of the RF board are like a BGA (square pads)and we have troubles to make the proper welding in the
Electronics Forum | Fri Jun 18 15:39:47 EDT 1999 | Earl Moon
| What's wrong with the Tin? Just wondering | | MDCox | | | | Electroless silver had promise, from Alpha, but I don't know where this ended up. Also Omikron's "white" electroless tin is proported to be a good alternative, though I've never been a
Electronics Forum | Fri Jun 15 12:12:34 EDT 2007 | realchunks
Hi Ed, It all depends on more info needed. How many preheaers do you have in your wave? One, two, three? Are you talking bottom side preheat? What size boards do you run and what type of parts are on it. Typically, preheat does several things; w
Electronics Forum | Wed Aug 27 14:19:40 EDT 2008 | grics
Have you given this information to your paste manufacturer???(Profile, Pics of defects?) The profile seems to look ok(without knowing paste info...) I think the ramprate looks a little aggressive but it could be the scaling of the profile and the i
Electronics Forum | Tue Sep 20 11:28:20 EDT 2011 | russw
We've got a Novastar 12S wave solder machine and we've been using Kester 951 flux for years with no problems. We just got a new bottle of 951 and it does not foam correctly (thin foam with lots of large bubbles). After a lot of back and forth with
Electronics Forum | Tue Sep 20 11:59:06 EDT 2011 | SheanDalton
Check specific gravity: According to a quick web search, the specific gravity should be 0.813 ± 0.003. If you have records of the specific gravity, compare current reading to past readings. Check pressure near stone: if you have records, compare
.gif)
