Electronics Forum | Thu Dec 29 10:47:05 EST 2005 | Chris
The paper Dave posted the link for is great. I have to go back and read it in depth. I can build prototypes by wirebonding to ENIG. I can do it on a manual wirebonder but I don't have the patience to do it on a magazine to magazine automatic machi
Electronics Forum | Tue Jul 01 17:38:24 EDT 2003 | jartman
I've faced this several times in the past, and the only real solution is to wirebond before SMT assembly. Everything leaves a residue, and trying to clean a residue off later is basically hopeless. This may require some trickery in your SMT process
Electronics Forum | Tue Sep 10 10:42:36 EDT 2013 | capse
Plasma cleaning is used extensively to clean surfaces prior to wire bonding.
Electronics Forum | Thu Nov 03 02:34:46 EST 2005 | Rosewood
We've recently encountered some problems with wire bond strengths. I'm looking for anybody that has had some experience with different types of substrate contamination and methods for cleaning. There is no visible contamination on the gold pads, bu
Electronics Forum | Thu Nov 03 12:48:14 EST 2005 | Rosewood
We have some no sticks, but that is actually a good thing because we have NSD. During process control audits we found that pull strengths to the board dropped off. We build a military application that requires higher bond strenghts. Low pull streg
Electronics Forum | Thu Nov 03 07:43:52 EST 2005 | davef
Questions are: * Is the problem 'wire bonds that don't stick' or 'wire bonds that fall or break off later'? * What materials are you working with? * What is your working time after plasma clean? * What does surface analysis tell you about surface con
Electronics Forum | Wed Jan 09 17:03:44 EST 2002 | rob_thomas
We follow IPC-2221 recommendations for Au and don't have a problem as long as the Ni is under 150 microinches.This ensures a consistent process for us.Also we do plasma clean after SMt and prior to wirebond.That makes a big difference. Rob
Electronics Forum | Thu Nov 03 21:40:40 EST 2005 | davef
There maybe multiple drivers to your problems. * First, decreasing bond quality with time indicates a plating issue. What's the actual thickness of your gold and nickel on the pads? * Second, the no-sticks indicate contamination. If it's organic, p
Electronics Forum | Wed Jan 09 18:17:15 EST 2002 | Chris
I don't have a plasma cleaner either. It will help a lot. Actually I don't clean at all. Our wirebond pads are far enough away so the flux residue does not get on the wirebond pads. That's what we think anyway. I am sure we have some degree of c
Electronics Forum | Wed Jan 09 17:14:48 EST 2002 | mregalia
Do you bond with Al or gold wire? What happens if the Ni is over 150 microinches? Thickness of nickel is one those things that we have not been consistent with. The industry seems to pretty much universally call for 100-200 microinches. Our old board
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