Wow, talk about feedback!
Ok, I'll go through the response one by one.
jpanhalt: Cracking idea! I have loads of ULP scripts for eagle, but rarely use them. Having a relatively small 'dot' in the middle of a pad, teoretically *should* centre the drill bit better, as well as easing it into the copper. With my 'standard' holes, by the time the bit had eaten far enough to start taking copper off...it was not so much 'drilling' as 'shearing' meaning tearing pads was quite common. That should sort it out a treat.
audioguru: You're right, the left one did have shorts (only 4 believe it or not), I guess my camera focus/tripod was the best. Sorted it out with a craft knife like a trooper. The right photo...well I thought it was pretty obvious that was 'pre-etch' just to show what the toner was like before etching, perhaps I should have explained it better. The shorts after etching were most likely because of residual paper in the trenches between pads, something press'n'peel should not do.
Hero999 and Bonuk:
Yep, the photo resist method would be far better for finer resolution, and I'm planning on using it for anything under 0.65mm pitch. For soic with 1.27mm or TQFP with 0.65mm this method seems to handle it. This was a test of toner transfer and its limits, as a half-arsed experiment to see if I can contribute something towards it.
Re photoresist... as the presensitized boards are fairly cheap, and with the price of UV LED's dropping, the leap from toner transfer to photo etching shouldn't cost much at all (in theory). As for developer, I don't deal with caustic soda (my pets would find it and drink it) so washing soda (pure sodium carbonate) should do just as well. 54p for 1kg at sainsbury's for all you UK people! I'll have to do a timing test for exposure times. I'm keeping this proper cheap here
Bonuk: I remember using the type of drill you mentioned !! My university had one, and it made drilling 500 holes in my final project a breeze! Alas, until I start making lots of boards, I can't justify the expenditure...that doesn't mean I can't steal ideas from it though... I've already designed/starting making, a plexi guide. Its very similar to the cover found on the drill you mentioned...a single 2mm hole, counter sunk, with a reticle paint on. With that fixed over the PCB, should making lining up those 0.6mm via holes a snap. But I still need to sort out the 'play' in my drill stand, don't think it was designed for a dremel300 (the gastly thing is coated in rubber). Cheers for reminding me about it though!
mneary: Inkjet transparencies? Wow, the other limit I can across was my laser printer. Inkjets have mahoosive resolution, and I wasn't aware you could get transparencies for them? Seems like this photoresist thing is the way to go after all...at least for fine high quality proto's, I'm still digging this toner transfer thing for guitar effects and basic circuits
The 'etch resist' pen I used, believe it or not, was simple a statler permenant marker. It was sold by rapidonline.com AS an etch resist pen. Guess I should point out to them it was about as resistant as the copper beneath it. Proper ER pens are too expensive. Hmmpf.
3v0: OOo cheers for that link, I have heard of pulsar, but being in the UK, could get hold of it. I'll pick some up once I get paid and give it a whirl.
jrz126: ahh SMT adapters
I use ebay for them, although futurlec seem to have them even cheaper. I must have at least 60 SMT adapters about, ranging from the usual SOIC8 to PQFP208. The 4-sided ones are always an arse to wire up lol If you would like a list of ebay shops that do SMT adapters (with cheap international shipping) I'd be happy to mesage you? I think for SOIC I could make my own for now. Still, probably worth it for finer pitches, then I can just deal with DIP packages with my PCB's, which this system handles with ease.
Last thing, a couple more pics, one FPC 0.5mm 16 way adapter. And one header board for an LCD controller. Both turned out surprisingly well.
Thanks guys,
Blueteeth