In a message dated 07/05/2000 4:12:28 PM Central Daylight Time,
[log in to unmask] writes:

<< Hi all,

 Sorry if this message is repeated, but I had no TN messages at all
 yesterday (including this one which I posted) so I'm not sure it got
 through.

  We are about to start using 2 sided 0.5mm PCB's. These are quite flimsy

  and our current methods of clamping the PCB whilst mounting (locate
 pins
  and edge clamping in Yamaha YV100/YVL88 (Phillips in the States I
  believe) and Fuji CPIV-3) bends the boards causing the 'trampoline'
  effect.
  My question is, how does anyone using 0.5mm PCBs support the boards
  during placement?
  Are carrier boards common or are different clamping methods utilized?
  How are the boards reflowed?
  Can/is a support wire used in reflow ovens?
  Any comments appreciated.
  Thanks
  David >>

Hi David!

.5mm boards are pretty thin, you'll need a carrier for those thin guys.
There's a company here in the states called SP Precision
(http://www.spprecision.com) that make a pretty good carrier...they can go
thru screen print, pick and place, and reflow.
I just tried their web page and couldn't connect, might be having temporary
server problems.

The last experience I had with a thin 2-sided PCB, was for a PCMCIA serial
card, and it was the same thickness as your board. I hated the damn thing.
The copper on each side of the board wasn't balanced at all, there was a lot
more traces on one side than the other, it curled like a potato chip during
reflow...there wasn't a thing we could do about it. I would make sure that
the copper content is equal on both sides or you may wind-up with the same
lovely situation that I had...

-Steve Gregory-

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