Electronics Forum | Fri Jan 17 02:49:11 EST 2020 | jakapratama
Yeah, that's a nearly uniformed ramp up profile, I can't see anything's wrong with that.
Electronics Forum | Sun Oct 21 22:17:19 EDT 2012 | eadthem
We have had this issue on several parts in the past, typically we use a grid of squares of solder paste on large flow areas, This helps reduce but not eliminate all voiding. I would be very interested in hearing what you come up with. O and what is
Electronics Forum | Tue Dec 31 17:05:20 EST 2019 | slthomas
Assuming you've already looked at optimizing your profile and stencil design, have you looked at metal load in the paste? I hadn't, but just read that increased metal load (associated with reduced powder size, i.e., moving from T3 to T4) has been sh
Electronics Forum | Thu Jan 02 22:09:15 EST 2020 | Zack
Hello, Can you give more detail on LGA parts in question? is 50 mm x 50 mm is overall size of the parts? What about pad pitch and how big is the pads individually? I assume that 50x50 mm is overall size. How about the stencil opening for the LGA pad
Electronics Forum | Thu Oct 25 13:39:29 EDT 2012 | cyber_wolf
Wait a minute...Your peak temps are PbFree like. Why is your profiler looking at time above 183 ? What is the time above 217 ? I thought we were looking at time above 217 not 183.
Electronics Forum | Thu Jan 02 10:30:42 EST 2020 | emeto
thank you Steve, when you mention Stencil design, what do you refer to? How about the Reflow profile? Any specifics that I should look for. Everything is in my process window, but some detail towards this package might be very helpful.
Electronics Forum | Sat Jan 11 08:57:26 EST 2020 | jakapratama
Hi Evtimov, Could you share your current reflow profile setting, and also your part technical datasheet on its heat tolerance? It might as well help other engineers to review and give their opinions.
Electronics Forum | Tue Jan 14 16:57:52 EST 2020 | emeto
Still considering going from 5mil to 4mil stencil. Concern is the 50mm part might have issues with contact on the outside rows.
Electronics Forum | Thu Oct 25 14:15:18 EDT 2012 | kkay
Yes it looks like I attached the wrong reflow profile and I'll get the new one in there. Our TAL should be between 60-90 sec over 217. I'm not sure the embrittlement would be an issue as we have seen this issue across at least 3 different board vendo
Electronics Forum | Fri Jan 03 10:32:42 EST 2020 | emeto
Zack, circles 36mil copper 35mil circle stencil aperture. Pitch is 80mil. Stencil is 5mil and apertures are spread 46mm under the 50mm component size. In my mind this might be too much paste. I am afraid that if I print 4mil I might get open joints
