Thank you for the very detailed post, Peter. Just one question: exactly what chemical do you mean by "meths"? Methl-ethyl keytone? Methyl Chloride? Methyl alcohol? Sean On Sun, Dec 13, 2009 at 12:57 PM, Peter Restall wrote: > > On Sat, 12 Dec 2009 13:43:54 -0500, Nathan House wrote: > >> Unfortunately, I still can't make PCBs. I can't get the toner to transfer >> from the paper to the board for the life of me. But that's another post = :-) > > Evening Nathan. > > Lots and lots of scrubbing - before you put your layout to the board, tha= t is. > The copper clad board needs to be spotless. =A0I use a pan scrub (nylon ?= ) for > this, with washing-up liquid - that takes away the grease and layer of > oxidation; the water ends up black afterwards, unless it is a new piece of > board. =A0After that I dry the board with kitchen roll (doesn't leave bit= s of > fluff or other particles behind) and then give the board a wipe with some > meths, again using a piece of kitchen roll. =A0Keep wiping with meths unt= il > there is no blackness on the kitchen roll from the board. > > After that I'm ready to press. =A0After attaching the schematic (a bit of > masking tape does the trick, but be careful where you put it - it will me= lt > and the adhesive will not come off easily; it's also etch resistant, so d= on't > get it on the copper side !) I put the board onto a hard and flat surface > between two pieces of grease-proof paper - this is to protect the iron ma= inly. > I then put the iron in place on the board and lean heavily onto it for one > minute without moving it, then after that I'll 'iron' the board - side to > side, up and down, using the edge of the iron mainly. =A0This bit takes a= bout > another minute or so. > > Once the ironing's done, I chuck the (very hot) board into some cold water > (no soap or anything - some people say it makes the paper peel better, but > I've had mixed results). =A0After a minute or two soaking, most of the pa= per > peels away; what's left can be scrubbed off with a toothbrush. =A0The bru= shing > can be done with a little pressure, but don't overdo it; if there is no > pressure and the toner is peeling away, your board probably wasn't clean > enough or the toner is not the right sort. > > The paper does not have to be completely removed; in fact, I tend to stop > brushing even when there are still plenty of gaps covered by a layer of p= aper > since too much brushing will eventually start to lift the toner. =A0When = the > board dries out after taking it out of the water, the bits between the tr= acks > will turn white and brittle; they're easily removed with a scalpel. =A0Th= e bits > of paper left over the toner are of no concern. =A0Take the opportunity t= o touch > up any holes with an indelible marker pen too; some types of paper will b= leed > the ink though, but if you've chosen the right type of paper then you sho= uld > be fine. =A0You should now be ready for etching. > > The paper I use is the glossy stuff from advertising pamphlets, brochures, > etc. that's pushed through my door. =A0I tried quite a few different type= s, but > this works a treat and is free. =A0I try to find some that is mainly whit= e; any > printing already on the paper doesn't tend to affect the etching, but it'= s not > good when you're trying to spot pinholes, defects, etc. after ironing. = =A0This > paper peels peels nicely too (photo paper seemed to be impossible to remo= ve, > regular paper seemed to be very fibrous but peeled OK, for example). > > Also, when you tell your printer to print, make sure that you set it up > accordingly; for example, I tell mine that I'm printing on transparencies > even though I'm not - this is because it lowers the fixing temperature wh= en > printing IIRC, so the toner should lift easier. =A0I also set the print d= ensity > to maximum, toner saving mode to off, page protection of, and I use 1200d= pi > resolution (not the interpolated '1200HQ' mode either). > > I've been using this method a fair while, and the last four weekends or so > I've been knocking up some quick test fixtures for my current project; the > copper clad board I am using for these is over 20 years old and black, bu= t it > scrubs up brilliantly and etches fine with how I've outlined above. =A0I'= ve > also done double-sided boards with this method too. =A0The key is getting= it > really clean I believe. > > A few months ago I posted some queries on toner transfer and some of my > findings to the piclist; search the archives and you might find the threa= d. > I seem to remember Vitaliy making some good suggestions at the time that I > didn't try - you may want to give them a whirl. > > Also, make sure you use an old iron. =A0For my first few attempts I decid= ed > to spice things up with a bit of 'Danger PCB-ing' and used the girlfriend= 's > best iron. =A0I broke it by leaning on it too hard, and then had to buy h= er a > brand-spanking-new super-deluxe (and pricey) model... > > Regards, > > Pete Restall > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist