Electronics Forum | Mon Jul 16 16:39:17 EDT 2007 | davef
We doubt that entrapped process chemicals cause under-etch. Over-etch maybe, but not under-etch Under-etch is an indicator of improper process control/improper chemistry during etching. Under-etch can result in bridging between traces, resulting in
Electronics Forum | Thu Jan 10 11:22:48 EST 2013 | pbarton
Looks to me like under etching of the underlying copper and the gold is just plated to all of the exposed copper surface. Is this characteristic the same on all solderable pads? You will not be able to remove this gold.
Electronics Forum | Tue Jan 15 10:35:08 EST 2013 | boriskilk
We would agree with Pete B about both the under etching as a possible issue and you will not be able to remove this gold. Another possibility is the solder mask (plating resist) hasn't been taken right to the edge of the pad.
Electronics Forum | Tue Jul 10 19:16:08 EDT 2007 | 5why
We have filed returned (approx. 5%) of the boards that exhibit inner layer short @ a particular connector locations. X-section revealed there exhibit Cu residue, but aside from that, we also suspect there could be organic contaminant, what test shou
Electronics Forum | Tue Apr 12 19:22:44 EDT 2016 | szs0080
Hello, I did drop testing of some sample boards which had 15mm SAC105&305 BGA's on them. I polished them real nice and looked it under optical microscope for cracks. Was wondering the etching procedure before looking it under SEM. Thanks
Electronics Forum | Fri Dec 13 10:40:08 EST 2002 | MA/NY DDave
Hi I hope more post on this one. Since it interests me and I haven't read enough on this topic in recent years. Donoughts with a dot in the middle I have seen. The dot in my opinion could be over or under etched or plated with the center of the do
Electronics Forum | Wed Mar 15 04:32:14 EST 2006 | rlackey
Hi Brad, I don't know if this helps, but we had a policy of not accepting x-outs on rigids, and of max 10% per panel on Flexy boards (as long as the local fiducial was blacked out for the bad board) I'm always suspicious of x-outs as it points to pr
Electronics Forum | Thu Aug 26 21:54:57 EDT 2004 | KEN
I ran into this about 2 years ago. The Rework Operators (all 3 shifts) would rework a device, rince the board with tap water (yep, 50k / Cm^3) from a nearby sink, then send the PCB to test (which is really ironic as they had to walk past the DI wash
Electronics Forum | Wed Mar 04 22:24:28 EST 2015 | SKR
We are using Nutek NTM4910-XL laser marker to etch 2D barcode on all our boards. We added solid silkscreen box on all our boards to create contrast. When we laser etch them, we just burn the silkscreen box so that we can see the soldermask under it c
Electronics Forum | Sat Apr 15 00:10:52 EDT 2023 | sarason
Having worked in a hybrid maanufacturing operation many years ago, yes stencils are great and have the required accuracy, but on the down side there were 2 operators that were absolute wizzes at turning them out and that could mean up to 20 stencil
.gif)
.gif)
