Electronics Forum | Wed Aug 09 08:06:07 EDT 2006 | davef
See "IPC-4554 Specification for Immersion Tin Plating for Printed Circuit Boards" 3.2.1 Immersion Tin Thickness. The most common reason for solderability issues with the white tin surface coating during multiple thermal excursions is a thin white ti
Electronics Forum | Sat Mar 05 22:44:44 EST 2005 | gpaelmo
You can also try the Florida Circtech website or call them direct. There is a min. thickness requirement and if the board house does not follow it you will end up with scrap boards after the second pass (from experience). I even sent blank boards to
Electronics Forum | Fri Sep 03 12:36:27 EDT 2004 | Frank R.
That's what I have ... two 5 zone reflow. A representative from AIM told me that 7 zone reflow is required with PbFree. It's good to know that it work fine with a 5 zones. Florida cirtech is the company who told me that SN100C do not damage your w
Electronics Forum | Mon Apr 23 17:30:08 EDT 2001 | davef
Step 1: Print paste on the board, skip placement, reflow the board, check solderability. Step 2: Goto Step 1. White Tin Solderability: The most common reason for solderability issues with the white tin surface coating during multiple thermal excur
Electronics Forum | Mon Nov 19 20:15:39 EST 2001 | davef
Now, that is one thickass board!!! The rant first: If our �board supplier changed our board surface finish on� anything without our approval, the board supplier would be an �X�. Life has enough surprises. And of all the flat finishes available, h
Electronics Forum | Mon Apr 23 19:12:23 EDT 2001 | relensky
Thanks for the instructions. I was missing the reflow part... Omikron is the method our board house offers. We have been through the plating thickness problem and tin depletion conditions. Beyond those issues, I have been trying a few different n
Electronics Forum | Mon Jun 25 21:02:42 EDT 2001 | davef
Try: 1 SMTA [http://www.smta.org] Knowledge Base Conference Proceedings: * 09/24/2000 COMPARISON OF AG, NI/AU, AND SOLDER PWB SURFACE FINISHES ON THE SECOND LEVEL RELIABILITY OF FINE PITCH AREA ARRAY ASSEMBLIES Lon E. Chase, Raytheon Electronic Syste
Electronics Forum | Thu Sep 02 15:45:35 EDT 2004 | russ
We don't do any wave, SMT only. We did not have to change apertures for lead free, we use the same stencil that we did when we ran water soluble with pb. This I think might be dependant upon your current design of both pad and apertures however.
Electronics Forum | Thu Dec 09 09:51:34 EST 2004 | russ
One of the things that I have found is the "benchtop/lab" type waves (Low cost) do not perform very well except on the simplest of products, they are lacking critical design elements such as adequate preheat length, laminar flow nozzle design, etc.
Electronics Forum | Sat Oct 06 08:27:24 EDT 2001 | davef
Yes, some solder masks do not tent well, because the material is too thin. That�s the trade-off. Thin masks: * Conform well to [don't bleed onto] fine pitch features. * Tent vias poorly, requiring an additional "plugging" step. As you imply, if th
