Electronics Forum | Thu Aug 10 10:52:11 EDT 2017 | ttheis
We are just using a stereo microscope at this time. When we first started out with these parts a year ago they filleted very well but with no apparent change they began having problems. While the boards do work, we are concerned about the long term r
Electronics Forum | Thu Aug 10 11:24:18 EDT 2017 | dleeper
The exposed metallization on the sides of the QFN probably aren't tinned and therefore not expected to have solder wetted to them. If previous parts formed nice toe filets, it might just be that those parts were fresher and the exposed metal did not
Electronics Forum | Wed Dec 04 08:15:55 EST 2019 | proceng1
You have a peak of 216 and roughly 40 seconds TAL. So you are right in the middle of the given ranges. So there's room to get things a little hotter and for a little longer. I am surprised you are having this trouble with TIN/ LEAD, as the process
Electronics Forum | Sun Nov 24 09:54:24 EST 2002 | davef
On a HASL board that has poor wetting on the pad, consider looking further downstream in the process than your assembly shop. For instance, take a look at the bare boards. Look for solder mask bleed onto the pads. This will show-up on the outside
Electronics Forum | Thu Mar 04 10:45:19 EST 2004 | Robert
My company is relatively small but we have a SMT line. However, we don't have a stencil cleaner so I resort to a spray bottle of denatured alcohol, wiping it with a cloth and then using a toothbrush to brush the apertures. Finally another wipe down a
Electronics Forum | Wed Mar 31 21:08:34 EST 2004 | Ed
Hey guys. I've been manually dunking circuit boards for 8 years now. I too have the excess residue issue to contend with. I'm using a low solids - no clean flux from Kester (959). I have used solvents, thinners, windex and a multititude of cleane
Electronics Forum | Wed Apr 21 18:24:13 EDT 2004 | pjohnson@volterra.com
Simple process - we use similar Kester solder brands of "no clean" low residue solder wick to clean our pads, then brush with isopropyl, and apply Kesters brand of tacky flux under a Leica 6x microscope. We do this on 7x7mm and 9x9mm packages. This w
Electronics Forum | Thu May 11 08:27:15 EDT 2006 | timnop
We will be receiving our lead free wave solder machine soon and I have been doing a lot of reading here. I've seen many dicussions about SAC vs. SN100C for wave applications and am leaning heavily towards the SN100C for my process. I haven't seen any
Electronics Forum | Tue Dec 03 18:51:57 EST 2019 | kylehunter
Hi all, We are having a confusing defect with one of our client's boards. It is a large board, 30" x 12". The client supplies the LEDs, they are cheap overseas diodes, and it is not uncommon to have reels with the packaging torn. We have w
Electronics Forum | Fri Jan 15 03:30:10 EST 1999 | Jeff Sanchez
| Hi all, | | I thought I'd use this forum to ask a couple general questions on fluxes for manual operations: | First - Is it OK to use a wave soldering type flux (specifically OA)? Thinking about activation temperatures and the ramp rate of the wav
