Tool for gerber to homebrew artwork (toner transfer, uv) - Page 1
Forum section: electronics / general

author: sleemanj
author_rank: Super Contributor
timestamp: March 29, 2014, 08:16:05 am
content: I thought somebody else might find the little hack of a script I wrote to convert gerbers into homebrew-friendly PDF artwork.Uses imagemagick and gerbv to get the job doneFull details here:https://github.com/sleemanj/gerb2etch/Download:https://github.com/sleemanj/gerb2etch/archive/master.zip

author: bench_knob
author_rank: Regular Contributor
timestamp: March 29, 2014, 08:23:11 am
content: Quote from: sleemanj on March 29, 2014, 08:16:05 amSleeManj,Nice tool, thanks for sharing. What program do you use for PCB artwork generation? (KiCad, PCB, Eagle, etc??)bench knob

author: sleemanj
author_rank: Super Contributor
timestamp: March 29, 2014, 08:33:22 am
content: Quote from: bench_knob on March 29, 2014, 08:23:11 amDipTrace and Fritzing

author: bench_knob
author_rank: Regular Contributor
timestamp: March 29, 2014, 08:08:22 pm
content: Thank you

author: nctnico
author_rank: Super Contributor
timestamp: April 01, 2014, 11:38:13 am
content: Why not distribute the Gerber and point people to Viewmate (pentalogix.com)? It's tough to get a PDF to print on a 1:1 scale drawing with all the different paper sizes.

author: sleemanj
author_rank: Super Contributor
timestamp: April 01, 2014, 01:13:53 pm
content: Quote from: nctnico on April 01, 2014, 11:38:13 amIf you want to get your boards produced by a board house, this is not for you.If you want to do it yourself, this makes producing the artwork you need an easy single command, and generates also useful annotations and placements to make life easier.If you can't print an A4 PDF at the correct scale then you printer is worthless and you have no hope to ever produce a viable PCB from it with or without my script, or "Viewmate".

author: nctnico
author_rank: Super Contributor
timestamp: April 01, 2014, 06:11:04 pm
content: So does Viewmate. I've made countless of boards by printing the layout on tracing paper (for UV exposure) using Viewmate. Replace tracing paper with toner transfer sheets and you have the same process. They don't use A4 all over the world. IMHO going the PDF route is just making things more difficult because you need to disable the automatic paper scaling before printing which may result in printing multiple pages or cropping in places you don't want it to crop. Did I mention automatic rotation and numerous versions of PDF readers so making a universal tutorial is almost impossible.

author: bench_knob
author_rank: Regular Contributor
timestamp: April 01, 2014, 11:52:28 pm
content: Quote from: sleemanj on April 01, 2014, 01:13:53 pmHi SleejMan,(probably a lot of work....there are newbies who very likely would appreciate your doing so)Perhaps you could outline, step by step, your process as well as the software tools (+versions) that you use in your process that works for you? I've always wondered how folks use the pdf method? Me, I use Eagle (v5.50, Academic, Standard, used to be around $150), I just print 1:1, gotta watch out though, they scale the print-out without warning, if there are any lines (I print targets and alignment lines to aid double-sided toner-transfer alighnment) outside of the board-size constraint limit. I'd be curious to know, I'm always interested in new alternative PCB processes.In any case, thanks for sharing.bench knob weenie

author: sleemanj
author_rank: Super Contributor
timestamp: April 02, 2014, 01:36:55 am
content: Quote from: bench_knob on April 01, 2014, 11:52:28 pmI use dry film UV exposure (mainly, although I use toner transfer for masking pads prior to soldermask application).Export the Gerbers (or from Fritzing export to PDF works too and that's what I originally developed the script to handle), and use my script to create a single PDF which has the artworks on a single page, my pcb's are usually small enough that it fits 2 columns and 3 rows so I can get 6 artworks (top & bottom, silk, mask and copper) on one sheet.The artworks have an added frame, an indicator on a common corner (so you can mark the PCB's edge in one corner and always know "that corner goes there on the artwork"), and spacing between artworks that precisely fit a ruler/T-square to make alignment easier when flipping a board to expose the other side on a flat-bed (eg scanner converted into UV table).I open the PDF in okular, and print it to tracing paper.A quick check of dimensions with a ruler, but I've never had a scaling problem, and verify that your parts fit the footprints of course.Expose (UV leds), develop (sodium carbonate), etch (cupric chloride), inspect (magnifying glass, multimeter continuity beeper) and fix (knife) any shorts. Strip the resist (sodium carbonate hot and strong, or acetone).Print the pads-only artwork only onto exercise book covering (polypropylene contact film, any stationary shop) stuck onto paper, use this to toner-transfer onto the pads, run under cold water until paper soaked and board handle-able, peel off the artwork (no soaking or scrubbing required with this book covering technique). Repeat to get double toner on the pads if it seems necessary.Airbrush with slightly thinned Pebeo Vitrea 160 (exactly this product, other similar ones don't work) available from many art supply shops in a variety of colours, when cured it forms a good imitation of a soldermask - durable, non conductive, soldering iron heat resistant and reasonably non-stick to fluxed solder.Leave (approx 2 hours) until dry to the touch (ignore the 24 hour drying time that on the V 160 label, that's for laying it on thick, an airbrush layer is very thin)Bake for 40 minutes at 180 degrees CCoolUse Acetone to remove the toner.Drill, insert pcb rivets and solder and confirm continuity, assemble components, debug, throw against wall, resume debugging, lose interest, regain interest, debug more, achieve enlightenment, bask in afterglow.I don't have a good way to do silkscreen yet. I guess you could use white Vitrea 160 for the soldermask and toner transfer to get black silk on white mask might be easiest, as long as you don't mind a white solder mask.(These were single sided hence the jumpers, also, some bodging).