kicad-developers team mailing list archive

[Vesa Solonen <vesa.solonen@xxxxxxxx>]

13/06/16, 00:47, Tomasz Wlostowski kirjoitti:

> This is the method I had been using some years ago when I did most of my
> PCB using toner transfer.

I've been using Gerbv to export ORed layers as needed, because I wanted
my mechanical layers on copper that KiCad can not do. The features like
hole and corner markers are helpful. Not to mention nicely blended and
colored documentation renderings. Inkscape for some fiddling like
redrawing old hand drawn boards of images. Panelization with:

http://pdfautonup.readthedocs.io/en/latest/

The last thing to remember before etching is the solvent vapor sealing
of the toner. Unfortunately the technically best (heavy, nonflammable)
chlorinated solvents are the most toxic, but both acetone and ethyl
acetate work with usual precautions.

> Couple of other tricks:
> - you can do homemade vias using car windshield heater repair kit (the
> stuff to repair broken heater wires in the windows of your car, Loctite
> sells it for ~20$)

This is pretty involved if one wants to plate them with copper as well.
I've done one by negative process using silver etch mask layer to test,
but that's way too much for me...  The final phase is quite amusing when
ugly gray silver chloride layer gets dissolved away and shiny silver
board results ;)

> - (not tested myself) I've heard that sprinkling a mix of acetone and
> isopropanol instead of transferring the toner to the PCB with heat
> yields much higher quality PCBs (see [1] - in polish, google translate
> should be more or less readable). Must test myself one day ;-)
> 
> Cheers,
> Tom
> 
> [1] http://domwlesie.eu/moje-projekty/amatorskie-plytki-transfer-chemiczny/

This is really neat. The trick is that isopropanol is used to dilute
acetone to adjust the solvent effect. The mix just swells the toner
polymer (quite often ABS), but doesn't actually dissolve it like pure
acetone would. What might make it even better would be to use higher
boiling ketone to get the toner to stick well on the substrate as
alcohol part evaporates first. Methanol as alcohol would help as well.

One could probably use a cold roll laminator for the transfer as well as
pressing.

This needs more R&D,

-Vesa