Chris,
We use flushmount tooling pin hold downs that allow the board to go through
the screen printer and pull the board taunt versus putting on a downward
pressure. Give me a buzz and I can tell you how they work,
Jim
972-494-1911
----- Original Message -----
From: Christopher Murphy <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, April 10, 2000 4:07 PM
Subject: [TN] Thin PCBs (or PWBs)


> Dear All,
>
> apologies if this question has been raised before.  We are currently
> looking into running a 0.5mm thick double sided PCB (142mm wide) down
> one of our SMD lines, but do not want to use carriers as we are in a
> medium to high volume production environment and do not want the
> inefficiency of manually inserting and removing PCBs.
>
> Does anyone have any advice on how to go about this?  We can design new
> vacuum supports for our placement machines and modify the locating pin
> type clamping mechanism so that it does not bow the PCBs upwards, but I
> cant figure out how to stop excessive sag on the PCBs during reflow.
>
> Also how about machines which use edge clamping for the PCBs - we can
> ease the pressure of the clamping back to stop board bowing but wont the
> clamping force then be too low and allow the PCB to move?
>
> For background info, the line consists of a Dek 265Lt, Fuji CP4-3,
> Philips Gem series machines (or Yamaha YV100, YVL88, YVL80), and a
> Heller 1500 reflow oven with pin and mesh conveyor.
>
> Any replies will be most appreciated !
>
> Thanks,
>
> Chris Murphy,
>
> Production Engineering Dept.,
>
> Tait Electronics
>
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