Electronics Forum | Wed Dec 08 17:45:38 EST 1999 | Dave F
Apologies to all who go beezerk (I'm one) when some maroon dredges-up an old thread (usually so they can babble in some thinly 'gised advert). I'm not doing that. I go more beezerk when we let someone's quiry go unanswered. Anyhow ... Francis: A
Electronics Forum | Fri Nov 05 21:22:34 EST 1999 | chartrain
Amazing in today's technology that people still bake because "that's the way we've alawys done it". Baking is a band aid for poor manufacturing of the PCB. Moisture can become trapped between the layers during buildup. This moisture when it contacts
Electronics Forum | Mon Jun 07 16:52:51 EDT 1999 | Dave F
| | | | I have difficulty to convince my management to air-condition our manufacturing facilities. The room temperature fluxuates from 8 deg.C in the morning to 25 deg. C in the afternoon. The PCB topside temperatures in the reflow oven and wave sold
Electronics Forum | Wed Apr 07 14:43:27 EDT 1999 | Dick Casagrande
| | Does anybody put QFP's on the backsides of boards? Can they be reflowed without falling off? Do you use adhesive? | | | I've seen QFP's on the backside and yes, they need glued prior to reflow - just a couple of drops on the corners. | | Scot
Electronics Forum | Fri Jul 10 14:40:12 EDT 1998 | Bob Willis
Yes this can be a killer. Its caused by glues with a high water content or fast curing of glues. When you get solder going through the glue it is litterally sucked in during solder wave contact. If you have never seen it you would never believe it bu
Electronics Forum | Mon Apr 28 09:34:37 EDT 2003 | davef
Double sided weight of component to total pad mating area ratio: 30 gm per sq inch (50 mgm per mm2) Go to the sites of these consultant-people for additional background [I'm not sure exactly where on these sites to look, but both are laden with goo
Electronics Forum | Wed Apr 28 16:07:32 EDT 2004 | davef
In rework, your thermal recipe needs to better mimic the recipe that your use in your reflow oven. Oh, that and proper preheating of the board and BGA. [Yano, if you get bored fighting this, rereflowing the board is within reason.] That you are hi
Electronics Forum | Fri Feb 17 09:35:00 EST 2006 | Rob
Hi, I take it you are refering to intrusive reflow? It came around as more components became available in surface mount packages leaving mainly connectors left over for a separate insertion operation & wave/selective/hand solder. Manufacturers imp
Electronics Forum | Tue Apr 25 10:13:17 EDT 2006 | slthomas
What kind of parts are on the bottom? Small passives are very unlikely (won't unless other abnormal factors come into play) to fall off when reflowed a second time regardless of temperature differential. There is a simple weight/soldered surface ar
Electronics Forum | Mon Sep 03 09:48:12 EDT 2007 | davef
Joris We don�t know the maximum period to store the boards without having problems with blowholes. Too many variables to determine. We prefer to just fix the problem, but understand that you have stock that you need to build-down. Determining mois
