Electronics Forum | Fri Jul 13 19:35:02 EDT 2007 | hegemon
We have had good success doing pb Free QFN work. Typically for the center pad we use ~68% coverage with 1:1 ratio on the perimeter pad. For the 68% coverage we have tried cross hatch pattern, diagonal stripes, dot series, and most successfully a clo
Electronics Forum | Thu Jul 05 22:56:53 EDT 2007 | gyverlo
Hello Sirs: Recently we are having an issue with environmental stress (high humidity or moisture), so we decide to apply conformal coating on our motherboard to protect via holes. According to IPC-A-610D, spec of thickness for type AR is 0.03~0.13 m
Electronics Forum | Mon Jul 16 12:03:42 EDT 2007 | davef
We're aware of no industy acceptance standard for max moisture content of a board. For more on moisture levels, get a copy of: "Removing Moisture from Electronic Components and Assemblies", CS Leech, Jr, Circuits Assembly, May 1994. The article disc
Electronics Forum | Fri Jul 06 12:11:34 EDT 2007 | james
We are starting to see issues with using Kester WS R562 with lead free components. The joints look grainy on almost all of the 0402'2 and other small components. Some of the solder does not solder to the terminations. These are hybrid boards which
Electronics Forum | Tue Jul 10 03:51:49 EDT 2007 | vangogh
Hi All, We are producing PCBA with COB process. We are using kapton tape to protect the COB pads from solder splashes/stains. Questions: 1) Is kapton tape an industry accepted way of protecting gold pads from solder splashes? 2) What are the chance
Electronics Forum | Wed Jul 18 10:35:41 EDT 2007 | hussman
This seems like an odd request from an auditor. I can see an auditor requiring proof that you meet the J-Std, but verify? This would require you purposely damage product on a "before and after" scenario. As long as your manufacturing guideline say
Electronics Forum | Wed Jul 11 14:48:25 EDT 2007 | rgduval
My boss just received some info through a design mailing list that he's on claiming that FR406 is not RoHS compliant based on the limited number of processing cycles at RoHS compliant temperatures. I would guess that this is related to the relativel
Electronics Forum | Thu Jul 12 16:14:20 EDT 2007 | realchunks
Hi Scott, Hard to tell what kind of problem you really have. I guess you need to describe your process first. What kind of process are you using. Wave solder, reflow solder, etc.. What kind of flux are you using to solder with? Vaccum? What ar
Electronics Forum | Thu Jul 12 16:57:46 EDT 2007 | jmelson
Canyou see this contamination? Is it solder beads, flux or something else? If flux, then more cleaning should help, either more time, more cycles through the cleaner, etc. If it is solder beads that are not melted to the rest of the solder, then s
Electronics Forum | Fri Jul 13 17:00:34 EDT 2007 | jmelson
Oh, sure, on fine-pitch parts you need a microscope or at least a good magnifier. But, OK, you have some kind of contamination. Solder is one thing, but where are these stainless, aluminum and copper particles coming from? Stainless makes me think
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