Electronics Forum | Mon Dec 08 11:46:09 EST 2008 | mleber
We are experiencing delamination / measling on card we have been running for years. No change in process. Same equipment, profiles etc. The weird thing is we are experiencing it on pwbs from different mfgs and different processes (reflow, wave, selec
Electronics Forum | Mon May 14 22:24:11 EDT 2001 | davef
The time over liquidous of the profile seems short. But then again, who knows? Based on what you told us, I'm guessing at a board fabrication problem, either measling or delamination. Probably the former, rather than the latter. [Now, we remember
Electronics Forum | Mon Dec 08 21:46:10 EST 2008 | mleber
Board House, Thank you for the info. We are baking 6 hours at 250F prior to processing. We are a military contract house that has always baked and have never had issues until recently. I appreciate the info. We are sending a team on the road to visit
Electronics Forum | Tue Oct 14 08:27:32 EDT 2014 | kkay
We use a few different style of press fit connectors, terminals, studs, etc. We use a tabletop arbor press for most everything we do, but a lot of times we will see some measling or slight delamination around the holes for the press fit part. Is ther
Electronics Forum | Mon May 03 11:20:43 EDT 2010 | mikesewell
A good guideline is keep it similar to your wave solder process, for example 2-3 sec. This assumes you're preheating the assembly. While polyimide boards are fairly robust at some point you will begin to see copper dissolution - the solder side pad
Electronics Forum | Sat Dec 13 17:46:27 EST 2008 | ysutariya
If you're military then you're probably just needing standard 130Tg FR4 and tin-lead finish. I would check two things: 1. Bake temperature: Isola recommends 300F for 4 hours to drive moisture out. Lower baking temperatures do not require a linea
Electronics Forum | Mon Dec 08 17:06:59 EST 2008 | boardhouse
Hi MGL, Couple things to ask, have the boards recently been changed to Rohs builds? STD FR4 to High TD Laminate. Check the stack-up the board houses are using. Just about all Rohs laminate has Resin starvation issues when used in single ply co
Electronics Forum | Thu Aug 09 09:05:09 EDT 2007 | davef
There are no requirements acceptance criteria for baking of board assemblies. What are your customer requirements? The common reasons people choose to bake PCB are to prevent: * Delamination of multilayer boards * Measles, particularly on double si
Electronics Forum | Thu May 14 22:45:46 EDT 2009 | davef
You're correct. It's a peculiar looking defect. With measling, we expect to see discrete white spots or crosses just below the surface of the base material. We don't see that here. We do see a similar condition at almost every PTH in the picture, a
Electronics Forum | Tue Mar 09 12:13:27 EST 2004 | Gabriele
I want just to confirm what Dave suggested you. J-STD-033a, par 6. Boards Rework tells you plenty of useful informations. 6.1 Component removal, RWK and remount 6.1.1 Removal for Failure Analysi 6.1.2 Removal & Remount 6.2 Baking of Populated Boar
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