Electronics Forum | Mon Mar 07 15:35:35 EST 2005 | John M
It has been my experience that the standard Fr4 material (Tg 135c) will discolor when processed at the new higher temperatures required for the high tin alloys... We have been using the High Tg Fr4 (Tg 170c) for many years to ensure this does not hap
Electronics Forum | Wed Nov 15 09:36:27 EST 2006 | Board House
Hi AJ, The biggest mistake in the industry today is documentation for lead free assembly required product. We are still seeing prints coming in saying Lead Free / High TG FR4. When in reality standard FR4 170 Tg. material is considered High Tg. and L
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 Jul 16 21:39:40 EDT 2001 | davef
The method you suggest is about the only way to �clean-up� this terrible situation. Realistically, this is a "memory" type condition induced by design, build symmetry, "cross ply construction", excessive cool down rates during lamination or reflow a
Electronics Forum | Sat Nov 04 21:30:15 EST 2006 | Ola
Well, I can't tell you what the "glass wicking failure on PCB" are but for a standard FR4-pcb the Tg temp. or the so called glass temp. is 176 celcius degr. This means that the pcb is in between a firm and a buoyant condition. This is really a bit of
Electronics Forum | Thu Sep 01 18:53:08 EDT 2005 | Board House
Pr. I agree with some of the above responses. if you are seeing Delam issues with incoming PCB's the following should be check. 1) Check the OEM Print to what Material they are calling out to be manufactured with. 2) If they are calling out for S
Electronics Forum | Fri Aug 21 04:43:14 EDT 2009 | ghepo
Hello, I suggest you visit the website http://www.analysispcb.com, where I found these information : PARAMETERS FOR DOUBLE “V” SCORING LEAD FREE LAMINATES Typ WEB Thickness, 1.6mm : 0.38mm (+.15/-0) "...Tg is not a good indicator of a materials’
Electronics Forum | Thu Apr 26 16:47:52 EDT 2007 | Cmiller
Is anyone using standard FR-4 material for ROHS? All I have ever seen to indicate the need to go to a high tg/td board is that the material may fail after repeted rework. I have a customer that is trying to use IS-410 and it is causing electrical pro
Electronics Forum | Wed Nov 28 22:33:24 EST 2007 | davef
There is no specification for lead-free HASL. You can use any lead-free solderability protection that meets your customer requirements. Use IPC-9701 �Performance Test Methods and Qualification Requirements for Surface Mount Solder Attachments� to ass
Electronics Forum | Thu Jan 20 16:06:38 EST 2000 | Mike Naddra
Regarding glass transition , does anyone have expierance glass wiht transition temperature specification , such as what are the detrimental effects of exceeding the Tg , how long over the glass transition temperature ,if any , is acceptable. Tg of di
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