Electronics Forum | Thu Jul 03 03:23:04 EDT 2003 | loz
I have been advised recently about pcb manufacturers, that somehow or other supply pcb's with contamination. Visually they are fine, but problems arise during SMT manufacture, ie solder balling, non-wetting on pads, and also during wave solder proces
Electronics Forum | Thu Jul 03 08:40:23 EDT 2003 | Kris
Hi, undercured solder resists may be a defect people have seen so far. Some of the probles arising is blistering as well as reaction with wave solder flux that may lead to some kind bad gel like formations. Gels the idea would be to reflow the ba
Electronics Forum | Wed Jul 09 19:05:06 EDT 2003 | randywomack
LOZ. Under-cured or out-of-spec(sloppily) applied resist is realistic. What other physics: Shiny resist surface is more prone to balls then matte finish. How about an operator eating fish & chips before handling the boards. Don't laugh... ... saw th
Electronics Forum | Thu May 01 15:42:53 EDT 2008 | ck_the_flip
Yes, the authors do give the caveat that small amount of lead contamination in a SAC/Lead-Free system is tolerated provided the Pb-BGA has sufficiently reflowed. This verbiage is on the bottom of Figure 10. For my own peace-of-mind, I would send yo
Electronics Forum | Thu Sep 01 02:51:31 EDT 2011 | zedor
HI, We currently have two SMT lines, one running leaded products and the other lead-free. There is a recommendation to combine the two to increase the line capacity. What do you think are the pros and cons, is there a risk in contamination ot the
Electronics Forum | Thu Aug 21 16:00:31 EDT 2014 | davef
This links to a NPL presentation on moisture removal from PCB http://www.npl.co.uk/upload/pdf/20140318_effect_baking.pdf Consider: * Focusing on preventing moisture contamination of boards, rather than removing moisture * There will be no standard
Electronics Forum | Fri Dec 08 02:40:45 EST 2006 | Mike Konrad
Hi 'K', We manufacture both batch and inline defluxing equipment so we have no axe to grind with either technology. There are pros and cons associated with both technologies under specific conditions. Batch machines are typically good cleaners but
Electronics Forum | Thu Jul 03 07:53:57 EDT 2003 | davef
That has to be the worst of all worlds. Someone goes out and buys the cheapest parts they can find, gives them to you [Loz], and wants you to assemble a perfect product. Well, it would be nice if you could console yourself by making Derick Jetter m
Electronics Forum | Thu Jul 03 18:14:03 EDT 2003 | russ
Kris, I don't know what I HAVEN'T SEEN yet cuz I haven't seen it. (HAHAHA) It is kind of like when you are looking for something and you always say after you found it that it was the last place you looked (Why would anyone keep looking for something
Electronics Forum | Sat Oct 18 11:01:04 EDT 2014 | leadthree
I just like to ask if somebody else experienced a similar problem: We press rigid flex PCBs at 356°F (180°C). The buffer layer construction is: Plate PET PVC PET PCB etc So far there were never any problems. But suddenly the PVC becomes very blac
