Re: UV Circuit Board Exposure unit?


Robin Szemeti - G1YFG
 

The film I use is a dry film from one of the many, many eBay sellers ... 30cm x 5m is about €5 

In this particular case I cannot do the "wire pins" as it is "sandwich" between two aluminium slabs that form the housing.  I don't mind having the chemicals, these are not the worst ones I have.

For the exposure films, I can print to 600dpi on my home laser printer, but for 4000 or 10,000dpi  I use this company:


The can do much higher resolutions on film, down to 5 um, but I never needed this.


On Mon, 6 Jun 2022 at 20:07, Gerhard_DK4XP via groups.io <dk4xp=arcor.de@groups.io> wrote:


Am 06.06.22 um 20:32 schrieb Robin Szemeti - G1YFG via groups.io:
> 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.
>

Is that something like MungoLux SF4000  photopolymer film ?
I have bought a 1m * 43 cm piece of it for testing with Rogers 4003
but did not use it up to now. ( from someone in .de, via Amazon)

I have never tried plating through the vias, I've seen it made in a fab
and I don't want the chemicals in my man cave.
I just drill 0.35 mm holes and fill them with wrap wire. Most of my boards
are single-sided + GND. That makes it easy to recycle the layout for
multilayers.

I think that stuff like Positiv-20 would plug the vias if applied after
drilling.

If it really matters (like uwave filters with thin slots) I print from
Gerber
to hi-res .pdf and have a print shop in the 'hood create offset film
from that.
A mask cannot be better than this.

73, Gerhard DK4XP









--
Robin Szemeti - G1YFG

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