Electronics Forum | Mon Jan 13 18:21:54 EST 2014 | vwhipple
A little confusion here. Are you running several boards in one pallet and the last boards are looking poor or is the issue getting worse as the day progresses (like as the pallets get warm)? - If it is the last boards in the pallet, then you may wan
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 | Fri Nov 15 11:03:48 EST 2019 | rgduval
I think Steve is on to it. The wire is not getting hot enough to wet. Either the solderer is attempting to solder too quickly, or the PTH is connected to a ground plane. The solder sticking up through the hole leads me to think it's connected to a
Electronics Forum | Fri Jan 29 16:17:13 EST 2021 | donnie15
The impact is low on larger pitches and pad sizes. as things get to the .4mm pitch the pad differences start affect your ball size and yields. The trace size going into the pads and the solder mask relief can cause some odd shaped pads with signif
Electronics Forum | Wed Apr 13 21:17:18 EDT 2022 | stephendo
If it was ROHS, I would say that the pads are definitely dissolved away. And it sounds like that is the case here. Your best bet is if it is class 2 and the barrels are at least 50% then push for them to be accepted. If you are trying for more barr
Electronics Forum | Wed Jun 03 18:22:19 EDT 1998 | Chrys
| Hello: | BACKGROUD: SMT components soldered on the top-side of boards that also require wave soldering have the potential to reflow during wave soldering. Reflowing these components during wave soldering is not good. It can cause cold joints, op
Electronics Forum | Mon Sep 21 20:45:55 EDT 2009 | davef
10.4. Pre-Cure Examination. Immediately after material application, the uncured conformal coating shall be examined for: a. Bubbles and Air Entrapments. These defects shall be broken by vacuum, with a sharp probe, or other appropriate tools. b. Bridg
Electronics Forum | Wed Aug 25 07:53:08 EDT 1999 | Scott Davies
| | Could use a little help here. Can anyone clarify to me the cause and fix of chip caps/resistors tombstoning following reflow? | | | | Any help would be appreciated. Thanks. | | | Most common reason is uneven heating where one side of the com
Electronics Forum | Wed Aug 25 09:48:28 EDT 1999 | Larry Koens
| | | Could use a little help here. Can anyone clarify to me the cause and fix of chip caps/resistors tombstoning following reflow? | | | | | | Any help would be appreciated. Thanks. | | | | | Most common reason is uneven heating where one side
Electronics Forum | Thu Jul 23 13:11:13 EDT 1998 | Gestapo Allen
I think that in general it's best to deposit paste in order to increase the part standoff. This helps improve the fatigue-life of the joints by providing more strain relief. But I know from experience that it's tough to deposit paste during the rew
