2 methods for making PCBs with an inkjet

[gez]

Are you all sitting comfortably?  Then I’ll begin…

The last few weeks I’ve been trying out everything and anything to get an inkjet to work at producing decent PCBs.  I’ve found two methods that both work well.  Both use photo board, but before some of you switch off you can use a fluorescent strip light to develop board by tapping it, plus your transparency, to the light’s surface so that it’s in contact with it.  The down side is the board can be no wider than the strip light, unless you develop in stages (a real pain!).  I’ve always mounted my boards vertically so I’m used to keeping them slim and this isn’t a problem for me.  Having said that, it’s not that hard to build your own exposure box - I’m sure many here have and might chip in.

The first method is of my own devising (though I’d be surprised if someone else hadn’t thought of it) but inspired by various posts I’ve read in the archives of this place: (They’re a pretty hard-core and innovative bunch - and I thought WE were nerds!)

http://groups.yahoo.com/group/Homebrew_PCBs/messages

Although you can buy ‘Jetstar’ transparencies for Epson inkjet printers, they only seem to work with Epson printers!  I also had a problem with the thin film crinkling under the heat of the light.  So I came up with the following.  Basically you print your artwork, reverse image, onto a bog-standard ‘glossy’ transparency intended for inkjet use.  I use Ryman’s (a UK stationers) own brand.  Then lay it on your board (ink side down), place a sheet of tracing paper over it (well, in my case Sainsbury’s ‘greaseproof paper’), secure it with masking tape and then develop.  Without the tracing paper it doesn’t work, the ink isn’t opaque enough, but with it the results are superb!

The second method uses ‘transparent’ spray made by ‘Kontakt Chemie’ in Belgium (so, not just chocolates then!).  You print off your artwork onto paper, spray this stuff on and it makes the white bits ‘transparent’ to UV - just tape it to the board (it sticks to it while still wet which helps) and develop.  It too works really well though the type of paper seems to determine the quality of the image.  It worked fine with the normal stuff I use, but not with a photo copy from my local printer (despite it being of better quality!).

ESR in the UK sell it, but I’ve also seen it elsewhere (don’t ask me where, I can’t remember).

www.esr.co.uk

I’ve always done my artwork by hand so I don’t yet have any PCB software, but here’s a couple of samples I did using lettering.  The one on the left is the spray.  Although it doesn’t show in the photo, the first method gives the best detail.  Dirt on the transparency caused the F to go wonky, but seeing as these were samples I didn’t bother cleaning it up (the shame!).




Anyway, thought I’d let you know…