Fantastic Double Sided PCBs at home using photoresist method

   As a hobbyist I always want to have my pcb in a professional way with 10thou trace to trace distance, double side and error free traces. Of course that was "nearly " impossible to make this kind of pcbs using toner transfer methods at home.

I have tried toner transfer method ,Press N peel paper and photopaper. Result ?
 None of these gave me nice results.   Because these methods are only good if you are doing a single-sided boards.

When you are making the double sided boards, ironing causes toner to melt and this makes the papers slip a bit. BUT if you are working with 10th traces ther shouldn't be any slips.

With UV photoresist method (photolithographic) which is also used in production of silicon chips http://pcplus.techradar.com/node/3059  the results are near perfect.

Step 1 Equipments and stuff

For Photoresist plating a bare Pcb:
 ---1 can of POSITIV-20 spray http://uk.farnell.com/kontakt-chemie/positiv-20-200ml/positive-resist-positiv-20-200ml/dp/80101 0   --nearly 20TL(Turkish liras in Turkey)

---or if you have access to sensitized PCB  dont' bother to buy a Photoresist spray, pre made pcbs are way better but In Turkey there isn't any so i used spray.

--- Hair dryer to dry your positiv 20 sprayed pcbs
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For Exposing PCB's
 ---1X Pair of glass at any size you like --Free
---2x 8watts of UV fluorescent lamps( I don't know the exact type uva-A or uva-b but these blacklight tubes are fine) ---3TL each
---2x Fluorescent modules which you can use it directly with  fluorescent lamps --6TL each
---Heavy books wtih more than 400 pages and hard cover, dostoyevski is a good choice for this job :D
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For Developing and Etching:
--- 1X Sink Cleaner in granulated form, infact it is just NaOH (Sodium Hydroxite) 0.5TL
--- 1X 1 liter Hydrogen Peroxide 7TL
--- 1X 1 liter Bleacher (hydrochloric acid) 1TL

Total cost: 46.5 TL equals to 31$

Comments

[cc67]

is this for inkjets or laser? tnx

[qualia]

can you get multiple uses out of your UV-mask transparents or does the inkjet ink degrade and if so how many PCBs will they do? i havent got a printer myself at the moment but if i do the layout and print photomasks at a printing company or the library i want to know how many duplicates it would be possible to make using the same photomask. this looks like a much more professional finish than i get from my cnc mill.

[thalass]

Where do you get your translucent paper? Overhead projector transparencies are quite rare and expensive these days in australia. And i can't seem to find anything else.

[stayputnik]

For instance: http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=vellum&x=0&y=0

[stayputnik]

Try searching for "vellum"... you should be able to find it at a stationery or art supply store.

[thalass]

Ah thanks. I was considering tracing paper, but i'm not sure if it's too diffuse - i might end up with light getting underneath to make the traces skinnier.

[patdoherty]

so you tape the design on then you expose one side then flip it over and expose the other?

[fluxuss]

Yeah, that's right but while exposing the first side, be sure that other side is not getting any light from anywhere. You can put hardcovered books on that side of PCB to ensure that.