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Date: | Thu, 30 May 1996 10:38:29 +0400 (EDT) |
Content-Type: | TEXT/PLAIN |
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Michael, I have no experience and 2 ideas:
1) Use a higher temperature solder for the aluminum-teflon interface
than that used to attach components;
2) Use one of those Metcal soldering irons which have RF heated tips and
don't get hotter than the solder melt temperature to attache components.
Lou Hart
.
On Wed, 29 May 1996, Michael J. Chmela wrote:
> Hello all:
> Do any of you have experience in automated soldering of SMT parts onto teflon
> type PCBs already soldered to an aluminum carrier?
>
> The PCB is either a Rogers RO3006 or Arlon EPSILAM-10 material that is reflowed
> to a tin plated aluminum carrier (up to .5"x15"x15") using solder paste.
> The configuration is reflowed under clamping pressure to prevent voids between
> the PCB and carrier. Afterwards, the SMT parts are soldered by hand. This
> process was choosen as a
> less costly method than procuring the PCB already attached to the carrier
> material and subsequently machined.
>
> The question is, how do we keep the soldered interface (PCB/carrier) intact
> while the SMT parts are reflowed? My concern is that if we switch to a higher
> temp solder for the interface to solve this problem, we will have problems with
> the PCB material after being exposed to that extreme temp. and
> have problems with the oven at those elevated temps. Cooling will also be a
> problem, because of the mass.
>
> Any comments from anyone with experience on this would be appreciated.
>
>
>
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