Electronics Forum | Wed Aug 10 10:41:23 EDT 2005 | patrickbruneel
Bob, Great theory if you're selling SN100C, but I have to disagree that an alloy being 4�C off eutectic will cause cracks. When a solder joint exits the solder wave, there is an immediate drop in temperature of 100�C. so being off 4�C is irrelevant.
Electronics Forum | Mon Oct 29 18:21:43 EST 2001 | slthomas
We recently have received a lot of warped (bowed and/or twisted behond IPC 600 specs.) bare boards (some our fabricator's fault, some ours by design) and I can't help but figure that long term reliability will suffer when building product with them.
Electronics Forum | Tue Aug 08 20:43:41 EDT 2000 | Dave F
Tom: So is warp or is it twist? They�re different problems, possibly with different sources!!! And possibly different solutions!!! Consultants to talk to are: Earl Moon (pod@vcn.com), Werner Engelmeyer (engelmaier@aol.com), Les Hymes (les.hymes@w
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 | Wed Dec 22 18:16:46 EST 2010 | padawanlinuxero
Hello ! I have a problem with one of high runner, our board comes in a seal package with dessicant cant really tell you how much RH% is inside the bag, but our board does not spend a lot of time in the shelf just some days or a couple of weeks max,
Electronics Forum | Thu Aug 05 20:11:31 EDT 2004 | Darren
Dhanish, There are a number of things to know before we can answer a large question such as yours. 1) what machine is being used. 2) how does the machine account for height at placement. 3) is the part rotated a large amount after placement. 4) is th
Electronics Forum | Fri Jul 13 08:54:18 EDT 2007 | rgduval
Has your board house reviewed the PCB layer stack? Make sure that the layers are balanced in copper weight, etc? Have you tried pre-baking the boards? We just had an issue with some boards warping that have never warped before for us. It happened
Electronics Forum | Thu Apr 20 17:51:52 EDT 2006 | Geo
When we have warpage issues we use Titanium Panel Stiffeners even though the stiffeners are mainly used for Wave we find little issue for reflow. Mind you the boards have to be large enough.
Electronics Forum | Thu Apr 20 17:26:15 EDT 2006 | russ
Well i wouldn't run every board then!!!! okay seriously, All bad parts off the same each time or are they "all over the place" Check your mount height, you may have sagging or warped boards or just bad part height
Electronics Forum | Tue Apr 09 08:44:43 EDT 2002 | davef
Read IPC-7530 "Guidelines for Temperature Profiling for Mass Soldering Processes (Reflow & Wave)". There is no advantage in dropping off much faster than 4�C/sec. In fact, you risk fracturing your newly formed solder connections due to board warping