In the early 60s, Trichlorethylene was used in vapor degreasers as the developing step of the Kodak Photo 
Resist (KPR) imaging process.  The KPR was a liquid photo resist sprayed on PCBs in a booth using a 
paint spray gun, and then dried over an open flame from a gas burner (honest!).  The panels were then 
printed by aligning and taping a negative film image over the drilled holes, then aligning the positive image 
to the negative film image, and then removing the negative film image.  The developing was accomplished 
in trays which were lowered into the Trichlorethylene vapor degreaser, with spray nozzles washing away 
the non-exposed KPR.  The panels were then immersed in a black dye, which provided the contrast 
needed for accurate touch-up, which was an intensive part of the process.


FRED J. PAUL					FLUKE CORPORATION
Sr. Process Engineer				POB 9090   M/S 55
PCB Operations					EVERETT, WA 98206
[log in to unmask]				206 347-6100
direct:	206 356-5734 (w Voice Mail)
fax:	206 356-6070 
[Ideas and expressions presented herein are my own, and don't
    necessarily represent those of the FLUKE CORPORATION]



On Fri, 02 Feb 96 19:26:47 EST [log in to unmask] wrote:

> From: [log in to unmask]> Date: Fri, 02 Feb 96 19:26:47 EST
> Subject: Trichloroethylene (TCE) Usage
> To: [log in to unmask]
> 
>      Hello Everyone,
>                     I'm seeking some historical information as to how and
>      where TCE was used in the PWB industry. While our experience is that
>      other chlorinated solvents were used in dry film processing
>      (specifically, 1,1,1 trichloroethane for film developing and methylene
>      chloride for stripping), we have some data that indicates TCE was used
>      but no one knows where.
>           Does anyone have information on what process uses TCE may have
>      been used, or during what period? This may be a question for your
>      historians, as I think it goes back to the 1960s and 1970s. If you have
>      some information or ideas, I'd be interested in hearing them.
>                                                               Lee Wilmot
>                                                               HADCO  Corp
>                                                         [log in to unmask]
> 
FRED J. PAUL					FLUKE CORPORATION
Sr. Process Engineer				POB 9090   M/S 55
PCB Operations					EVERETT, WA 98206
[log in to unmask]				206 347-6100
direct:	206 356-5734 (w Voice Mail)
fax:	206 356-6070 
[Ideas and expressions presented herein are my own, and don't
    necessarily represent those of the FLUKE CORPORATION]