Electronics Forum | Mon Jan 13 18:22:55 EST 2003 | davef
100 sec) and decrease reflow temp to 205C. * Understand that voids are primarily process indicators. There is experimental evidence that voids retard crack propagation locally around the void on a temporary basis. There is no standard, IPC or otherw
Electronics Forum | Tue Feb 25 10:32:09 EST 2003 | davef
I don't know the precise scheme, but it goes something like this ... WHAT TO DO * Use the general work instruction that applies to all boards. It goes into dimension and hole checking processes. It talks to visual instection of solder mask, solder
Electronics Forum | Fri Feb 28 08:57:34 EST 2003 | davef
We used to bake [100*C for 6 hours] all of our boards, but no longer bake at all. Before going off, your bake recipe is probaly OK. If anything, it's probably too short. Consider measuring the weight of wet boards, baking for a time, measure, bake
Electronics Forum | Tue Mar 18 17:13:47 EST 2003 | Carol Stirling
Hi -to all those familiar with MSL, I have a few questions on Moisture Sensitivity Levels (MSL) with ICs. We have been assured by our distributers they mark any package of ICs shipped according to J-STD-033. We receive ICs marked as Class 3 and up,
Electronics Forum | Mon Mar 31 11:10:43 EST 2003 | davef
First, most �thermal shock� recipes are not a reliability test. There is no relationship between the failures seem in these tests and in-use application. These tests show you the failures in these tests. That�s it!!! Second, accelerated life test
Electronics Forum | Wed Apr 23 13:33:31 EDT 2003 | davef
We divide our operations, repair, and office facilities into work area classifications, each with its own set of requirements and necessary control to meet the requirements of our procedure. The requirements are in the areas of: * Air Quality * Ligh
Electronics Forum | Thu Apr 24 13:35:51 EDT 2003 | fmonette
Hi Jason, Welcome back to SMTnet. I just wanted to clarify one important detail relative to dry packing Moisture Sensitive Devices. Contrary to popular belief, it not necessary to use vacuum when sealing Moisure Barrier Bags. A simple heat seal w
Electronics Forum | Tue May 13 06:57:10 EDT 2003 | davef
Your vendor site is totally correct. 2Ag is an excellent solder, but it does nothing to prevent tin and gold from reacting chemically. An earlier poster is correct gold goes into solution in liquid solder very fast, less than a second. Gold and ti
Electronics Forum | Fri Jun 06 07:23:18 EDT 2003 | johnw
Hi Kevin, the profile doesn't actually qualify something as lead free or not it's purely the Pb content of the assembly that does this. Currently the understanding of the limitations of the lead in the jont is 0.1% by weight or less. So as long as y
Electronics Forum | Thu Jun 26 21:38:31 EDT 2003 | Dreamsniper
Hi Guys, Need your good advice about this for a 5 thou stencil thickness: 0603 pad is 50mil x 40mil 0805 pad is 75mil x 45mil 1206 pad is 70mil x 50mil I want the above apertures to be in IPC STD Homeplate Design + an area reduction of 15%. Will t
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