Electronics Forum | Fri May 07 09:25:55 EDT 2010 | dwonch
Yes, the vias under the BGAs are the only ones capped. I tend to agree with you that the leaching should affect the bottom more than the top and that was actually the case with the two previous shops that had this problem. We suspected with those s
Electronics Forum | Mon Feb 05 20:43:27 EST 2001 | davef
1 Solder on gold fingers comes from: 1a About 70 % of the time it's caused by poor cleaning of screen printer, staging area (table), conveyor, reflow oven chain or belt, and keeping boards separate from cleaning process 1b After loading paste onto
Electronics Forum | Tue Aug 22 16:02:07 EDT 2000 | Dr. Ning-Cheng Lee
If the thermal mass of the products is small, a tent-shaped profile is recommended, with peak temperature around 240C. The hottest spot on board should be less than 250C. However, if the thermal mass of the product is large, such as a large server PC
Electronics Forum | Fri Jun 23 20:45:12 EDT 2000 | Lee
Hi Dave, You make a very good point. I think that the concern over lead is not so much in user's contact with the lead during the product's active life, but after its disposal. There is some valid concern over lead leaching out of circuit boards
Electronics Forum | Thu Sep 16 20:55:35 EDT 1999 | Dave F
| | We have some SMT components with gold plated leads. They're actually LCC led packages. A good solder alloy to use would be Indium / Lead to reduce tin dissolution into the gold and avoid the resultant brittle intermetallic compound. However, a re
Electronics Forum | Fri May 21 12:24:21 EDT 1999 | KA Stillings
I normally handle the soldering issues for this facility but a question was asked of me -- What the H@## is this stuff and what is causing it? Was wondering of I could get some input from any Guru on plating issues. Need info ASAP!!!!!!!!!!!!!!!!!!!
Electronics Forum | Wed Mar 24 02:23:14 EST 1999 | P.L. Sorenson - Technical Consultant
| | | Has any one seen failures of chip resistors after 1-2 years where the junction between the silver termination and the restive element on the top of the ceramic has corroded through. This results in a high resistance failure after this period of
Electronics Forum | Thu Aug 06 17:25:55 EDT 1998 | Earl Moon
| Is there any problem using SMT on gold boards? 15 years ago we were told not to use gold boards, but I can't remember why. Judging by the other postings it now appears to be common. Only problem I see is that the nickel should be plated, not ele
Electronics Forum | Mon Mar 30 07:41:06 EST 1998 | Earl Moon
| Hi, | We have encountered de-wetting issues with gold plated components( SMT LEDs ). | The problem comes and go and we yet to locate the root cause ( process, component or solder paste etc ). | The rest of the components on the boards are not havi
Electronics Forum | Thu Aug 30 11:59:00 EDT 2001 | Spanky
Hey all, I have 3 questions about reflow. Hopefully someone can help me. 1. I am having a problem. I set the peak at 230 and my mole thermocouples are telling me the temp in that zone gets to 237. How is this possible even if the thermocouple
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