Hi Steve,

Thanks for the response. The boards do have selective electroplated 
copper pads for components like Zif connectors but PTHing the dielectric 
and aluminum is quite a different challenge. We have worked on a number 
of PTH options but no success as yet.

As for why we don't just use normal copper, the boards are currently 
being used in cryogenic applications where they need a superconducting 
monometal path through to the chip and in sensor applications where 
radiation absorption needs to be reduced. And it's just fun making stuff 
few can.

- Paul


On 2/27/14 2:02 PM, Steven Creswick wrote:
> Paul,
>
> I would have loved to bond to bare aluminum if we didn't also have to mess
> with those pesky passive components that people always seem to want to put
> on the boards as well!
>
> I know that aluminum can be plated, but I don't know the specifics of if it
> would work in vias as well.  Likely be easier with large vias rather than
> plugged vias though - will leave that to the platers, but would be good to
> check for yourself.
>
> This may be totally out in left field, but why not just use a normal copper
> process and ENIG plate?  Good for Al wedge bonding and good for soldering...
> And the board construction process is generic.
>
>
> Steve Creswick
> Sr Associate - Balanced Enterprise Solutions
> http://www.linkedin.com/in/stevencreswick
>                           616 834 1883
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Paul Jackson
> Sent: Thursday, February 27, 2014 2:31 PM
> To: [log in to unmask]
> Subject: [TN] Aluminum fine-line PCB
>
> Hi All,
>
> I'm new here to Technet so I'll ask you to be gentle, at least at first.
> We are manufacturing fine-line aluminum trace PCBs and our customers are
> mainly wirebonding chips directly on the aluminum and attaching components
> on selective copper pads. We are trying to find a more elegant way to
> achieve through-hole connectivity than our current method of filling vias
> with solder wick braid and aluminum solder paste. It works but it's "fugly".
> The aluminum is 30µm and the dielectric is typically 2.1mil. Any ideas would
> be greatly appreciated.
>
> Paul Jackson
> Omni Circuit Boards
> (855) 798 9717
> *w*ww.omnicircuitboards.com
>
>
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Omni Circuit Boards Ltd.
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Richmond, B.C.
Canada V6V 1Z4

Tel. 604.276.9717
www.omnicircuitboards.com


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