Silk screening copper with etch resist ink

Community PCB Design
1

Hi Guys,

Rather than buy expensive presensitized copper - has anyone tried silk screening copper with etch resist ink? (silk screening appeals becuase I’m possibly going to be making a fair few boards - all the same)

Is it possible to get decent results with SOIC IC pad size tracks?

What mesh size would be best?

Anyone got some tips wrt the type of ink that I should be looking at? (Nazdar seem to do some etch resist ink, but I’m in the UK & can’t find any sources here - are there any other brands/ink types that will work?

thanks,

Pesky.

2

You need something like printers ink, it has to be gooey.

When I was a student at English Electric, Kidsgrove, in the 1960s, they made low-spec PCBs using silk-screen techniques.

I wouldn’t bother with it, photo-etch is much easier and gives much better results.

3

I tried it a long time ago with a hobby screen printing kit that I originally bought to print PCB legend.

It undercut too much using regular acrylic ink. It was much easier using photosensitive board with artwork laser printed on transparent film.

Circuit specialists still carries this stuff.

4

Thanks for the info guys - I’ll not bother!

5

If anyone is still interested I have many years of experience in the screen printing industry and have successfully made PCB’s at home with the screen printing process. I have even made double sided boards using dedicated feed through pads and jumpers for connections between sides. Using a 220 strand per inch mesh works well and allows a resolution more than good enough for between DIP pad traces. I haven’t made a board for surface mount components but I’m sure I could. The key is making sure the emulsion side of your film positive is the side that contacts the screen when it is exposed to prevent under cutting the image. While other methods are useful for making prototypes or small batches, the screen printing process can’t be beat for doing large runs of identical boards.

6

Same here, this was my first jobs in the PCB industry, silk screen printing of PCB’s.

A pot of ink (warmed in the oven first), a fine screen coated with UV sensitive stuff, exposed to UV with the artwork then cleaned off

then ink spread on - screened & the board cured in a UV oven.

I did single & double sided boards well.

(well until I decided I would be extra fast & messed an entire job lot up lol).

AFAIK This process is still in use today by small manufacturers for small runs.

Although the investment in the equipment, space etc may not pay back as much as it costs to get them done cheaply

at one of the batch manufacturers.