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 <> wrote:

Am 05.06.22 um 18:09 schrieb Robin Szemeti - G1YFG via
> 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.

   > 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  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  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

73, Gerhard  DK4XP

Robin Szemeti - G1YFG

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