Electronics Forum | Fri May 02 12:41:16 EDT 2003 | Chris Lampron
Hi Chris, I had worked for a flex circuit house for 10 years. You should be able to follow your solder paste guidelines for times and temps. You may want to consider pre-baking the flex if it is made with Kapton. Kapton is Hygroscopic and will delam
Electronics Forum | Tue Oct 24 08:07:42 EDT 2006 | markb
We are experiencing an issue with RoHS boards delaminating during SMT. In tyring to determine root cause, our board mfg house states the issue is with the laminate. The laminate supplier states that the board house is not taking the proper precua
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 | Wed Jan 09 14:46:29 EST 2008 | chef
Besides changing fluxes, do you have good knowledge of actual flux volumes? Do you have a micrograms per square value? Pre-heats can affect flux by burning off too soon and also not enough - therefore moisture hits the wave- how's your humidity cont
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 Jan 12 02:29:13 EST 2009 | sachu_70
Hi Milan, One cause for such BGA failures could either be a laminate warp (bow or twist) formed during your Reflow or Wave soldering process, or perhaps a warp seen on the BGA component package itself prior to processing on SMT line. IPC guidelines f
Electronics Forum | Wed Apr 08 11:05:53 EDT 2009 | boardhouse
Hi, Need a little more info, 1) this board is definitely delaminated 2) this board looks like a Std FR4 board with 63/37 Hot air finish with probably 140 tg. material. Was this reflowed under lead free temps? 3) Do you Pre-bake product 4) What
Electronics Forum | Wed Jun 12 13:27:28 EDT 2013 | joeherz
Our customer wants to do an overmold operation (3rd party to us) on the non-populated side of a rigid flex assembly. Their inquiry below: "We are going to end up over molding plastic over the back of this rigid flex to form an enclosure but wanted
Electronics Forum | Mon Feb 09 09:00:17 EST 2015 | jax
Outside the MSD issues stated already (and I cannot provide a exact time not knowing multiple factors like Humidity levels, temps, exposure times, etc...) OSP might be the very worst finish to use in this scenario of side 1 / store on a shelf / side
Electronics Forum | Thu Jun 29 12:07:09 EDT 2017 | georgetruitt
HOW THICK IS THE BOARD? IS THERE A LOT OF COPPER IN THE BOARD? DOES YOUR CUSTOMERS PROVIDE HEAT RELIEF IN THE BOARDS BARREL DESIGN THERE NEEDS TO BE PLENTY OF ROOM FOR LEADFREE SOLDER TO FLOW, DID YOU CHECK YOUR PIN(LEAD)TO HOLE (BARREL) RATIO? N
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