Electronics Forum | Mon Sep 28 09:35:28 EDT 1998 | Clive Heke
I have had some field failures returned recently, the boards had flux contamination under the components in a sensitive area, Nothing really visible until the component was removed, and the board had no evidence of rework of any type. Is it possib
Electronics Forum | Thu Dec 15 11:06:05 EST 2005 | Samir Nagaheenanajar
You might wanna try a small reduction in your stencil aperture. For example, for a 30-mil pad go 26-mil square aperture with 8 to 10-mil radius on your corners. Also, look at your designs. Is there enough resist between your pad and ball? Another
Electronics Forum | Fri Nov 22 05:04:07 EST 2019 | SMTA-Matthew
We have some circuit boards where the solder mask seems clear instead of green on top of some of the tented via pads. No gold deposited during the ENiG process and no solder sticks to it but why is it clear and does it have any correlation to the thi
Electronics Forum | Wed Jun 16 07:35:28 EDT 2010 | scottp
Rather than tent the thermal vias, we use a small annular ring of soldermask around them and only print paste in the areas between the vias. Any way you go you're going to have voids under QFNs, so we just try to make it repeatable so our designers
Electronics Forum | Mon Mar 02 23:48:22 EST 2015 | vb7007
Hi We are using Universal carrier for a 2 sided PCB, where the bottom side goes for hand solder the switches after wave. Our issue is, we are getting micro solder balls all over PCB bottom after wave, whereas we got numerous vias, which also turns
Electronics Forum | Thu Feb 07 20:53:51 EST 2002 | davef
Regardless of the technique used for the mounting pad shape or definition, isolation of the plated through hole [PTH] from the mounting pad is important. If the PTH is contained within the mounting pad, solder will wick down the PTH. The amount of
Electronics Forum | Tue Dec 14 22:17:33 EST 1999 | Dave F
Armin: How ya doin� bud? CK gives good advice, but I'd like to take a bit of a different angle. Q1. For 0.7 mm (0.027in) diameter hole for vias, what�s the minimum annular ring for this hole diameter? Depends on what you�re trying to do. For in
Electronics Forum | Mon Oct 18 09:41:56 EDT 1999 | Wolfgang Busko
That should not happen. There are some threads concerning BGA and wavesoldering you could look for. It�s said that you should protect the vias in the BGA-area by soldermask or at least with tented vias to prevent rereflow of BGAs solderjoints what co
Electronics Forum | Wed Jun 10 15:10:55 EDT 1998 | Rich
I am looking for the Industry standards on vias. Are they required to be plated with solder or is copper plating enough? What about reliabilty with either one? Also, if tenting the via is required should it be copper plated or solder plated over c
Electronics Forum | Thu Oct 01 11:40:17 EDT 1998 | Justin Medernach
Are there anyone who can give me the answer about solder ball problem? | We have 12 layer PCB and double sided PCB. After one side reflow soldering We found lots of solder ball under the PCB. The solder ball was coming out from via hole. | So
