Electronics Forum | Fri Apr 24 07:55:12 EDT 2009 | davef
TOMBSTONING OF 0402 AND 0201 COMPONENTS: "A STUDY EXAMINING THE EFFECTS OF VARIOUS PROCESS AND DESIGN PARAMETERS ON ULTRA-SMALL PASSIVE DEVICES" Michael Yuen, Heather Benedict, Kris Havlovitz, and Tim Pitsch, Plexus Electronic Assembly Corporation, N
Electronics Forum | Fri May 15 13:17:18 EDT 2009 | tomsmiley
We implemented an inexpensive home dishwasher solution last year for cleaning assemblies. It works very well for both lead free and tin/lead cleaning. DI water at room temp is all we do and the boards come out squeaky clean. We had to use the least
Electronics Forum | Fri May 22 08:04:30 EDT 2009 | stevezeva
Have any of you ever worked with Actel's QFN 180? A three row I/O QFN? Actel has a published paper on design and assembly guidelines, but we're finding that they are pretty much generic, and don't really work as well as they lead you to believe. ht
Electronics Forum | Thu Jun 04 20:06:30 EDT 2009 | davef
Since posting the above comment extolling the virtues of NSMD pads and disparaging SMD pads, we've learned that the points apply to all array devices, but in spite of that some designers of fine pitch [eg, 0.4, 0.5mm pitch] array devices choose SMD w
Electronics Forum | Wed Jun 10 08:46:20 EDT 2009 | rgduval
We generally purchase RoHS for all; leaving leaded-only assemblies as the exception. We process leaded and lead-free components together in leaded products with few issues. As long as the customer doesn't mind the mix (I'm sure that some out there
Electronics Forum | Fri Jul 24 07:43:56 EDT 2009 | davef
Your customer is correct. You are doing something wrong in your hand soldering process. Solder balls are a process indicator. Areas to assess are: * Moisture content of the bare board * Thickness of the copper plating in the through holes * Temperatu
Electronics Forum | Thu Jul 30 13:52:34 EDT 2009 | davef
Thoughts are: * 215-220 temperature at the leads is not real hot for leaded assembly. * It's peculiar for component leads to dewet. Sometimes non-wetting occurs along the edge of the lead where the lead is not plated. * How do the leads of a removed
Electronics Forum | Mon Aug 31 09:27:33 EDT 2009 | jamyboy
With Pronto Place I can generate a Mydata program and automatically merge an Excel bom in about 20 seconds. Takes longer if I need to produce assembly doxs...but still faster than Circuit Cam...have used the Mydata macro in the past also, but it does
Electronics Forum | Mon Nov 09 12:12:41 EST 2009 | mcmark
Same here, I've been programming Mydata placement machines using CircuitCAM since 1999, at 2 companies. With an ASCII CAD file imported and simple BOM scrubbing, we can get programs directly output to our Mydatas in less than 5 minutes. Developing as
Electronics Forum | Tue Aug 25 08:04:26 EDT 2009 | davef
Trapped moisture can be a problem, and one standard recommends baking a PCB for a minimum of 4 hours at 93+/- 5.5ºC before conformally coating. [NASA-STD-8739.1, “Workmanship Standard for Staking and Conformal Coating of Printed Wiring Boards and Ele
