Electronics Forum | Tue Jul 10 11:49:20 EDT 2007 | samir
Parallelism tends to drift: �h After preventative maintenance �h From dross buildup or other obstruction clogging either wave Parallelism should at least be studied during the process characterization stage, so that you know your machine's process
Electronics Forum | Tue Jul 10 07:22:48 EDT 2007 | davef
Q1. Is kapton tape an industry accepted way of protecting gold pads from solder splashes? A1. No. It is more accepted to resolve the reason behind the solder splats, so that the added labor and cost of taping is eliminated. Search the fine SMTnet Arc
Electronics Forum | Fri Jul 13 16:45:37 EDT 2007 | losersk8er
The Contamination has proven to be pretty random, lots of stainless steel though in fact two cases in the past two days. As far as I know all machinery is cleaned regularly as well, even the stencil washer itself. The boards we make are 90% (at l
Electronics Forum | Fri Jul 13 12:32:14 EDT 2007 | rgduval
We've experienced this issue with SN100. A couple of things we've tried, all with varying levels of success: 1. Longer pre-heats. We use SN100 in a solder pot, and pre-heat the boards on our wave machine. This did have a positive effect, but I ne
Electronics Forum | Thu Jul 26 13:08:59 EDT 2007 | Mike Konrad
The best method of cleaning misprinted boards is with a stencil cleaner. I would not recommend the use of a spray-in-air system for misprints. Spray systems can cause solder paste to become embedded into vias and under components (if double sided).
Electronics Forum | Sat Jul 28 08:37:52 EDT 2007 | davef
There is no good choice. Board Finishes: Industrial/Battelle Class 3 Environment [Reliability Knowledge Gaps: For use of Pb-free solders in High Reliability Applications, J Smetana, iNEMI Availability of SnPb-Compatible BGAs Workshop, March 1, 2007,
Electronics Forum | Tue Jul 31 22:06:12 EDT 2007 | davef
We had no problems reflowing an assembly on Bergquist Thermal Clad. The assembly was small. So, we built it on a 8-up fixture. It stayed in the fixture from screen print, through pick and place, and into reflow. When the fixture came out of the r
Electronics Forum | Thu Aug 09 09:05:09 EDT 2007 | davef
There are no requirements acceptance criteria for baking of board assemblies. What are your customer requirements? The common reasons people choose to bake PCB are to prevent: * Delamination of multilayer boards * Measles, particularly on double si
Electronics Forum | Tue Aug 21 20:52:06 EDT 2007 | davef
There is not standard for the force to pull an axial lead from a soldered connection. ".....IPC does not have pull tests in any of its standards, and some reliability experts would prefer to keep it that way, pull tests are commonly used by some lea
Electronics Forum | Tue Sep 04 15:08:51 EDT 2007 | floydf
We have a job that has through hole components on the top, and one 44 pin j leaded PLCC on the bottom. Presently we put the through hole parts in, run it throught the wave, dispense paste on the PLCC pads, and then apply hot air. Someone suggested we
