Electronics Forum | Wed Oct 12 11:02:59 EDT 2016 | hken
I think stencil manufacturers back fill half etched fiducials with black epoxy or something. I know I've had some worn and that's what I've done for my vision systems to be happy again.
Electronics Forum | Thu Oct 20 12:33:39 EDT 2016 | cyber_wolf
We get our fids laser etched and never have fid read problems. They are black. (see attached) All of our printers are Momentums. Half etch and fill is old school. I used to take 2 part epoxy and mix black printer toner into it and squeegee the mi
Electronics Forum | Wed Oct 12 13:44:10 EDT 2016 | dekhead
Yes, bottom-side fids are usually half-etched with epoxy fill. just the half-etch gives a pretty "dirty" looking fid.
Electronics Forum | Thu Oct 13 02:46:49 EDT 2016 | andreimoris
Yes, I read about filling the fiducials with balck epoxy, but it was said that it doesn't last for long. Thank you for your reply.
Electronics Forum | Wed Nov 09 09:11:36 EST 2016 | sumote
Yes, I read about filling the fiducials with > balck epoxy, but it was said that it doesn't last > for long. Thank you for your reply. They don't last for long? They should last forever. The fids are on the bottom of the screen. Why would they w
Electronics Forum | Wed Nov 16 10:20:18 EST 2016 | markhoch
Why would they wear off? Many people use ultrasonic stencil cleaners which will breakdown the epoxy over time and wash it away.
Electronics Forum | Sun Feb 22 15:46:09 EST 2015 | slave2anubis
Hi, my name is Dacian, and i run a mobile phone repair shop in Timisoara, Romania. Lately we decided to do more advance motherboard repair jobs, and a big problem that we have is, cleaning the board after we remove the chips. We repair manly iPhone,
Electronics Forum | Tue Mar 24 22:03:39 EDT 2015 | davef
Here's some notes from IPC APEX 2015: * Black underfill is Heraeus. It needs to be preheated to 180-200*C for rework. Above 200*C it changes state and becomes difficult. * Clear underfill is from an unknown Korean supplier. * People from Heraeus w
Electronics Forum | Wed Dec 06 21:59:37 EST 2006 | SMTrework
Hello, we rework BGA packages that come back from the field. I've seen on occasion a black and or red "epoxy" substance from the manufacturer on the corner of some board's BGA chips that I imagine are applied to increase corner bond of the chip to th
Electronics Forum | Wed Dec 06 22:46:39 EST 2006 | SMTrework
Hi Dave, This is manufacturer applied epoxy / adhesive to minimize package "lifing" from chassis flexing and thius board flexing. I have seen the complete array area covered with this black or red epoxy in some cases (i.e. the underfill that I've
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