Re: UV Circuit Board Exposure unit?


Robin Szemeti - G1YFG
 

Hi Gerhard,

Because of the process I am using, (drill, plate through holes, etch) I have to use a "dry film" etch resist applied after the holes are plated. The etch resist then goes on top and protects the vias during the etching process. I cannot use a wet/spray film as it will not protect the vias.


On Mon, 6 Jun 2022 at 17:00, Gerhard_DK4XP via groups.io <dk4xp=arcor.de@groups.io> wrote:


Am 05.06.22 um 18:09 schrieb Robin Szemeti - G1YFG via groups.io:
> Hi,
>
> I had, and possibly still have ... a nice RS unit for exposing circuit
> boards.  About 20 years ago, I decided I wouldn't be doing any more of
> that and put it away, or possibly threw it away ...
>
> As it happens, I now have need of one, and despite crawling around the
> loft for an hour, I have failed to unearth it.
>
> If anyone has one they wish to dispose of for a reasonable amount,
> before I throw myself on the mercies of eBay, kindly ping me ... 8" x
> 6" would be ample.
>

I use a face tanner from the local super market.

<
https://www.flickr.com/photos/137684711@N07/50834544133/in/album-72157720109860238/
   > and the pics to the right.

An exposure takes abt. 10 minutes, mostly because the thick glass sheets
swallow a lot of UV.
The boards are presensitized by bungard.de  That is good for 4/4 mil
rules if the film is OK.
They do not have Rogers material, but will coat it for abt €36 / sheet
when you send them the
nekkid boards, whatever you have. I did not try that.
For small amounts, see www.segor.de  search Bungard.


I used Positiv-20 by Kontakt-Chemie for Rogers TMM6. I could not get a
quality coating with that,
but it worked in principle. I heard that it works better in a warm
environment.
<
https://www.conrad.de/de/p/kontakt-chemie-positiv-20-82009-ah-fotokopierlack-200-ml-1333428.html
    >

73, Gerhard  DK4XP







--
Robin Szemeti - G1YFG

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