If you want a conductive aluminum coating take a look at alodine. http://en.wikipedia.org/wiki/Chromate_conversion_coating But I'm confused. You said chromate coatings were non-conductive... I thought they were? Gary On Fri, Feb 10, 2012 at 12:51 PM, Blair Hogg <[log in to unmask]> wrote: > I've got a slightly off-topic question for Technetters, but I know there > is probably a few here that would have a good answer. > > We are looking at creating shorting plates for use in a self check > application for our in-circuit test machines. The idea is that we would > test resistivity of the test probes through a shorting plate on a periodic > basis to determine when we needed to replace the probes in our fixtures. > > I was thinking aluminum, and I don't believe that the small layer of oxide > that forms would add significant resistance. The oxide may cause some > problems and the plates may need to be specified to have a cleaning process > prior to use. Chromate coatings are non-conductive, and the probe pressure > probably won't penetrate the coating in a reliable manner if any at all. A > copper clad board with ENIG plating or Au electroplating would probably be > better, but cost may be a factor. And since I would need one for every > fixture I have to match the physical characteristics of the board I need to > be cost conscious while ensuring adequate performance. > > So the question is, would the Al oxides adversely affect performance? > Would Cu clad FR4 with ENIG plating last long enough as the ENIG is rather > thin? Any other ideas? > > Thanks, > > Blair > -- ---------------------------------------------- Gary A. Crowell Sr., P.E., CID+ Linkedin <http://www.linkedin.com/in/garyacrowellsr> Elance<http://www.linkedin.com/redirect?url=http%3A%2F%2Fgaryacrowellsr%2Eelance%2Ecom&urlhash=kJm9> KE7FIZ <http://www.arrl.org> ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________