Phil,

Especially of you're contemplating purely mechanical contact, I strongly
suspect there will be pronounced degradation of conductivity over a period
of time, owing to differential metal corrosion effects. This will be more
so when extra electricity is added. You will have to leave the aluminium
fairly free of protecting chemical treatments in order to make good initial
contact, but as aluminium naturally oxidises over time, and aluminium oxide
is non-conductive, I can bet good money your conductivity will get loused
up sooner rather than later.

I take it that you have a space problem, and don't want to use too much by
fitting connectors instead, huh? I don't have an answer t the problem
without knowing the space you have available. Soldering a stand-off at one
end might help, but the heat required and strong fluxes would be too much
for a poor board to cope with. You may have to electroplate the stand-offs
with gold maintain contact and give adequate protection against corrosion.

My poor thought for the day.

Peter




                    Phil Nutting
                    <PNutting@KAISERSY        To:     [log in to unmask]
                    STEMS.COM>                cc:     (bcc: DUNCAN Peter/Asst Prin Engr/ST
                    Sent by: TechNet          Aero/ST Group)
                    <[log in to unmask]>         Subject:     [TN] connecting aluminum to copper


                    04/11/02 04:12 AM
                    Please respond to
                    "TechNet E-Mail
                    Forum."; Please
                    respond to Phil
                    Nutting






Good afternoon TechNet,

Would anyone like to share their knowledge about using an aluminum standoff
as a conductor when connecting two circuit boards together.  I suspect that
if it were aluminum to copper there would be an issue, but what about
aluminum to HASL surface of circuit boards?

Thanks in advance for your wisdom,

Phil Nutting

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