Electronics Forum | Mon Apr 07 13:12:02 EDT 2014 | cyber_wolf
Gary, We are missing something here. I see no evidence of reflow at all. If you have a thermo couple under the inductor, 237 deg with a TAL of 48 seconds should work all day long.(even though it may be on lower end of process window) SAC melts at 21
Electronics Forum | Mon Apr 07 15:14:41 EDT 2014 | garym4569
I drilled a small hole from the other side in order to get my thermocouple under the inductor pad. I did not have anything on hand to fill the hole, so I covered with kapton tape the best I could. I suspect that is why it looks like it should work.
Electronics Forum | Mon Apr 07 15:22:17 EDT 2014 | garym4569
Found the issue. The footprint is incorrect. The inductor completely shields the paste from heat. Slid the inductor on the pad to expose the pad and paste, and perfect solder joint. This part was a last minute design change with a larger body.
Electronics Forum | Tue Apr 08 08:04:57 EDT 2014 | cyber_wolf
Ahhh...now this makes sense. Glad you found the issue. Gary, try using aluminum tape to secure thermocouples. It works much better than kapton in my opinion. KIC sells it, but I'm sure it can be found elsewhere.
Electronics Forum | Wed Apr 16 16:58:00 EDT 2014 | jimmyboz
My first guess, loose wire or bad cable. Email me and I will send you a checklist.
Electronics Forum | Thu Apr 10 07:00:12 EDT 2014 | asajedi
I would like to output optimized feeder list in a text format for my inventory clerk to sort the components in the same order and the feeders.
Electronics Forum | Tue Apr 15 18:49:37 EDT 2014 | hegemon
Evtimov, Are you talking about placing an already built POP package, or about building the POP package at the SMT line? 'hege
Electronics Forum | Wed Apr 16 19:17:11 EDT 2014 | hegemon
OK, POP already done, and you are mounting the POP device. You are seeing opens. Opens at the device/PWB? or opens at the device/device interface? Or possibly both? 'hege
Electronics Forum | Mon Apr 21 10:50:13 EDT 2014 | cyber_wolf
The top PoP part is what gets dip fluxed or dip pasted. We have had warping issues with these components before but it is almost always the top part. My guess would be bad components if your reflow profile and print process is good to go.
Electronics Forum | Wed Apr 30 14:41:55 EDT 2014 | emeto
Thank you all for the posts. From all I read lately I will probably try a different solder paste and if that doesn't work I will go for a flux feeder. I will keep you posted.
