Electronics Forum | Tue Sep 06 12:39:06 EDT 2011 | deanm
According to IPC-7351A, the optimum fiducial is a solid circle with a minimum of 1mm diameter, but can be up to 3mm. There should be a solder mask clearance a minimum of 2x the radius of the copper circle. So the minimum fiducial size is 0.040" with
Electronics Forum | Tue May 22 10:33:36 EDT 2012 | swag
In my opinion, the best solution is h-towers or similar dedicated tooling designed for each build. However, a quick cheap fix is to make templates to lay in the bottom of the centernest. If you have access to CAD software, you can print out the ger
Electronics Forum | Mon Jun 04 18:06:01 EDT 2012 | swag
Once a day is excellent QA but my experience has been that it's overkill. We check various products at the start of the run - it amounts to a couple of times per month at most. Over the years, I have not seen any problems with the ovens. The only
Electronics Forum | Thu Aug 30 13:02:37 EDT 2012 | rway
This may have been asked, but what ESD protection does your facility already have? With proper techniques and equipment, this should be a non-issue. As long as folks aren't using the pcb's to comb through their hair, you don't have to worry about i
Electronics Forum | Tue Nov 06 22:37:35 EST 2012 | davef
Ryan ... "As for bismuth-based lead-free alloys, a lower melting temperature than that of tin-lead is offered together with a cost similar to that of tin [in the area of $3/lb]. Unfortunately, bismuth in soldering alloys tends to create embrittlemen
Electronics Forum | Wed Dec 26 16:52:57 EST 2012 | davef
"Advantages of Bismuth-based Alloys for Low Temperature Pb-Free Soldering and Rework" Author: Brook Sandy, Edward Briggs and Ronald Lasky, Ph.D. Abstract: The increased function of personal electronic devices, such as mobile phones and personal mus
Electronics Forum | Sat Jan 26 21:33:39 EST 2013 | sarason
Looks like you have a carbon black process that isn't quite plating to completion, pin prick size holes have remained in the plating. When dipped in an etchant (ie any acid or H2O) the holes grow and they leak carbon. This may be more of a problem th
Electronics Forum | Tue Feb 05 15:55:54 EST 2013 | rway
http://www.cotorelay.com/images/stories/coto_wp__reliability_ver_003.pdf I believe this was provided mainly for informational purposes; however, you don't need all that. You just need a magnetic field. A simpler approach than what I have already m
Electronics Forum | Mon Feb 11 13:07:30 EST 2013 | deanm
You want your machine to spot the fiducials automatically. A 40mil round copper pad is the absolute minimum fiducial to use, but we found in practice that our Quad equipment won't spot them reliably. I am now using a 60mil round fiducial and it picks
Electronics Forum | Tue Mar 12 10:16:05 EDT 2013 | bocci572
Yes the components are flat and no larger than 50mm in size. Most are full rings or just an arc of a ring. I understand fully the best way to have the capabilities proven would be to have the vendor demonstrate. I am kind of looking at what people
