Electronics Forum | Fri Apr 17 21:46:18 EDT 1998 | Matthias Mansfeld
I plan to design a multichip module which contains 1 chip with about 200 pads and 2 chips with about 50 pads, no other components.The whole module shall replace as intermediate solution a single chip CPU in QFP208. Thus, the MCM itself must have t
Electronics Forum | Fri Oct 05 16:05:58 EDT 2001 | seand
Hello everyone, Your chief variable here is going to be your epoxy. Different materials react accordingly to various inspection methods but, DEPENDING on your print parameters and material, you may be able to utilize an inline inspection machine.
Electronics Forum | Tue Oct 09 20:40:48 EDT 2001 | davef
No one suggested that you speak for other suppliers and nor would they want� you �to speak for them." You shouldn�t make this something that it isn�t. All that was requested courteously was suggestions of alternate suppliers that could be considere
Electronics Forum | Tue Dec 11 17:55:07 EST 2001 | davef
Ah, a desperate one. The kind we prey upon, mmm Several points are: * There are ample sources of information on the net that describe the fabrication of prototype boards. * Search the fine SMTnet archives for additional information. For instance:
Electronics Forum | Wed Jan 09 12:20:00 EST 2002 | mregalia
Thanks for cluing me into IPC-2221. Though the numbers they give seem to contradict what I have learned from people working with the materials. At least I now know where the guideline for a max of 30 microinches of gold for soldering comes from. But
Electronics Forum | Wed Jan 09 15:24:49 EST 2002 | mregalia
Thanks Chris. As I was writing my last message our mailperson dropped off the latest issue of Circuit Assembly. It has an article on mixing SMT and COB on the same board. The author recommends as a compromise 10-20 micro inches of gold over 70-100 of
Electronics Forum | Tue Mar 12 22:27:50 EST 2002 | davef
I'd speculate that the properties of a well formed solder connection processed in air and N2 are indistinguishable. Then again, the pitch is that N2 gives a wider process window, especially for NC flux-types. In the SMTnet Library look for: �Opti
Electronics Forum | Wed Mar 27 21:20:30 EST 2002 | davef
There is two major BGA coating camps. * Camp #1: "We require the coating to be under low stand-off devices but with no filleting. So we apply a thinned dip coat first, and then top-off with a proper spray coat" * Camp #2: "We want no coating under th
Electronics Forum | Thu Apr 11 20:35:22 EDT 2002 | davef
Messy. Messy. Messy. Consider gluing these components, until you control your process. It is unclear to us that a single factor drives these defects, but multiple factors that need to be tuned to work well together. PAD DIMENSIONS * Some SM-782 pa
Electronics Forum | Tue May 21 06:33:37 EDT 2002 | hayashi
*the other components are 0402 and SOIC 16, the > solderability were good. *the protection on the > terminations of microleadframe package is > Cu(copper),somebody call that leadless leadframe > package(LLP). *the time above 210 deg C is about
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