Re: Creating a PCB
csr1981 said:
the simple procedure for making PCB is as follows:-
1)draw the layout of your circuit on a tracing paper
2)then plot the layout on the copper plate.
3)after this paint the plotted layout on the copper plate with a oil paint.
4)now put the copper plate in FeCl3 solution for few hours.
5)now take out the Copper plate from the FeCl3 solution
6)the board is noe ready.Only you have to do drilling where your components
leads are to mounted.
I hope this helps you
Hmm, Is better to using PCB-cad program IMHO , print out on ordinay or semitransparent paper - not plastic - check black part i really high density black with using new toner catridge (mostly not work with refilled, but try...) or pigmented ink in inkjet printer.
IMHO not recomend OH-plastic sheet - this give granulary of toner and result low density black and hair fine cracks and need 2 sheets together for usable black density, but still bad board-line contrast.
After printing and check size (possible need adjusting size and/or aspect ratio in PCB-program or printer drive, or if not possible (for example P-cad2000, can resize but not adjusting aspect ratio - ghaaaa), print to Postcript-file and edit in PS-resize commands (search on net) and print out to printer via ghostscript)
Place printed paper with black traces down to surface of P20-resist coated copper/FR4 plate whith glass and put in few inch from 2 tube flourcent light lamp serveral minutes (try before for right time with small sample piece of P20-board, paper with black printed lines)
UV-lamp goes much faster - but works at home with normaly flourcent lamp with big part of blue visible light. I not try yet, but possible work with halogen lamp.
develope in NaOH-solution (14 gram/litre water if remeber right) and inspect for pure copper in lighting area and still P20-resist in darked area and sharp boards-line between light and dark area.
remember - toner or ink can not give totale solid darking, only give more attenuat on light and give small usable working window with ligthing area remove P20-resist and 3-10 times lower exposed black area in traces resist from developer, but this situation is easly to overexpose and all P2-resist cleaning of by developer...
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Is possible to handle crackfree 8-mil traces and 7 mil insulation on this process after exercise and buyed precoated P20-resist boards... hardest point is a find right type of semitransparent paper... (huimidity in paper is importent factor to give good and crackfree traces on laserprinters, plastic sheet is a total useless)
(hmphf if i written 'cracks' with out 's' in text, and replaces to 'fix' in submit process and meanig goes lost... Americans forbidden words.. ghaaa)
my experience only related to laserprinter, not to inkjet printers, but i think going same method. Printers to days have very high resolution and possible to make good home made complex circurit board for expriments.
I'm etch in 1/3 part of acid chloride ( 30% - 50% possible find in painting store) and 1/3 part Hydrogenperoxide (30% H2O2, also in painting store) and 1/3 part of water to slow down process and etch in very well vented place (dont smell of gases under process - have small part of pure chloric-gases make of solved copper
and is _not_ healty...)
after this, wash careful and drill, after this, remove P20-resist with aceton or isopropanol and applicate _thin_ layer of solderable proctective laque or use immediatly and after mounting and test, using proctective laque.
fingerprint on unprotected pure copper can ruin circurit and make cracks in small traces only on few weeks - use gloves if possible and always clean careful from fingerprints before applicate protective laque. (fingeprint still continue etching under laque if not cleaning off before protection laque....)
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different etch bath is a FeCl3 solution told above and working faster in higher temperature - but stay long away from stanless steel bench, sink etc. Small drop of this solution more than few seconds on surface, starting correcive process immediantly and still going slowly to make a hole in bench after couple of year... you cannot wash enogh to stopping this process if beginning to corresive.... (I try this - and ruin whole sink to sieve on my old company...)
Used FeCl3 can refreshed more or less endless with hydrogenperoxid (H2O2) and acid cloride (HCl) (little more acid compare to H2O2 in mix and stirred down if not want huge foam, spots and cooking, and still small foam - use more HCl in next mix) and solution going hot on refresh process and is possible to store to next time etch (but in not sealed container first days to went out oxygene). Is good idea using refresh mix (with fast stirring) short time before to warm up etch bath for incrase etching speed.
third etch bath using amoniumperoxide solution and working only if temperature around 50 degree Celsius, and is not storeable because to slowly giving oxygene under storing. Not sealed container here, even with short time store between etch moment
Amoniumperoxide is a safest version of etch bath
All handling of all type of etch bath need using trashable wear and using protect glasses and well vented places and under etch need contious agitate liquid to fastest possible and even etch.
/xxargs