And I don't even make PCB's!

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The way I did it on the (very few) double sided boards I've bothered to make is basically like nigel said. I'm not sure how his specific recommendation would work, since you'd have the pattern exposed on the first side while ironing the second side, and it might stick to the table (maybe you could iron against a plastic sheet that it didn't stick to...) When I did mine, I drilled a few of the holes through the paper patterns themselves, ironed one side (leaving the paper on), drilled the same holes through the board, placed a pin through each hole, dropped the other pattern down onto them, tacked it in place, removed the pins, and finished ironing. The accuracy of relying on holes drilled through your transfer paper is questionable, of course. This might be easier when using semi-transparent transfer sheets like Press-n-Peel, as you could drill through the first pattern AFTER ironing it on, and then line up the second pattern by just shining some light through the holes, no pins needed. I'll have to give that a shot someday...

Some people leave an inch or two of extra paper on one side of the pattern, place them face-to-face, carefully line them up using a bright light, and then tape that one edge, forming a sort of 'clamshell' of the pattern. I've never tried it, but it seems if you're careful during ironing (especially when initially positioning and tacking the patterns) it could work out alright.

I'd be quite interested to hear from people who do double-sided boards more regularly and can share their tried-and-true methods...

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Yes, seems to me I did try Nigel's way in the past, and yes, the toner sticking to the surface below was the problem, and the reason I started doing one side then the other.
The pulsar paper is totally opaque, so the second way is out.

Something I've been thinking about trying, though, is the use of a silkscreen, which I'm thinking would not only work well for registration, but you could make multiple copies of a board. One could use a photo resist on the screen to make the image of the traces, then screen print using acrylic paint. Now I curse the day I discarded my silkscreen!

At some point though, it would be just as effective, and a much better result to send the gerbers off to a board house.

 

Well if you're going to go to those lengths, just switch to the photoresist method, and enjoy the ease of duplication and pattern accuracy better than you can get with any other DIY methods... I can't imagine a homemade silkscreen pattern would be anywhere near good enough to do solid, crisp traces, much less get anywhere near 10 mil widths (or less)...

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I've seen some pretty amazing 3 color screens with lines about that size, however, I think you are right. There is a point of diminishing returns, and for all the trouble, I would just be as well off to send the design off to sparkfun.

Now back to that board, see if I can even finish one today with toner transfer!

 

I would think if you covered the toner with the green foil it would not be sticky. I use the foil but never tested for sticky.

The pulsar paper is dense but you can align the holes with a light table or by holding it up to a light. We have done that here and it is mentioned on the pulsar site.

So far I have made two 2 sided boards. I etched one side, drilled all the holes and then masked and etched the 2nd side. To protect the side I am not etching I covered it with box tape. It leaked in about 1/8 inch around the edges but the blank was a bit bigger then the finished board so it did not matter.

Etching by rubbing with a sponge is much faster then any submerged method. It makes etching twice less painful. I have not tried it on boards larger then 2 by 4 inches.

3v0

 

The guy who made the post was just mushing the paste into the holes by hand. He was tired of soldering wires into his vias.

3v0

 

the way i do double sided boards is use 1/32" pcb and make top and bottom on seperate boards drill the holes then glue them together sand the edges and you'll never know it was 2 seperate boards to start with.I tried the other way and the problem was 3/4 of the holes would line up perfect but the other 1/4 wouldn't and I figured there was a certain amount of shrinkage going on from the heat that you never notice on a single sided board but it's there,plus if your using an iron the shrinkage is really random could be in the middle of the board or just one end but it's always there.I have not had a single problem making them with 2 seperate boards as for glue anything you want to use because once everything is soldered the 2 boards are not moving anywhere I usally use crazy glue

 

Wow. Well, on one hand, that is definitely something I never would have thought of and seems kind of crazy, but on the other hand, that's sort of how multilayer (4+) boards are made...

Hey, whatever works

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I would print both disigns on the same piece of paper in reverse of each other and the thickness of the PCB separating the two. I would then fold the piece of paper round the PCB and iron each side.

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yea that's why i tried it,if it works for board house's why not me? and it works great everytime so far and your finnished board is 1/16" thick when your done.what more could you ask for(don't say easy via's)

 

3v0, next time I'm in that store (it is way on the other side of town ~ 1 hour drive) I'm going to pick up some of that green foil... I also have some drills to return to another store over on that side of town. I bought a pack of constant shank drills, which were inserted in a foam block, then shrink wrapped. The shrink, (or customers squeezing the package) broke all of the smallest bits, which were the ones I bought the package for. grrr

Bbarney,
That sounds like a workable solution, next time I buy pcb I'll have to get some thin one sided stuff.

Hero,
I think that it would be difficult to print this way from EAGLE, and folding it well enough would also be quite difficult. I did try hinging two sheets, but the holes were off by just enough to make the board unusable.

Evandude, if I had my technique down as well as you, I probably wouldn't need to go double sided. My traces, especially the thin ~10 mil, don't always come out straight (too much pressure.) I think I had the magazine paper tech down a lot better, but when I switched to the Pulsar stuff, and had the first few flake, added more heat, and more pressure. Perhaps I just have to make a lot more boards.
Well I prepped one side of a board the other day, and transfered it to the copper, but the toner has gotten 'mighty thin.' I picked up a new cartridge, but haven't put it in yet.

 

BeeBop
Yes try the new cartridge first.

I use a laminator and have never had problems. I got it because I dislike the variability of a hand held iron. The pulsar site has a method where you roll a large dowel under the board while you iron it. The idea is it applies high pressure in a laminator like action.

If you are in real trouble give Frank (IIRC) at Pulsar a call. He can help you iron out (pun) any problems you are having with the process.

 

I use a laminator too,used to iron them on and was really sucsessful with that method but the laminator is oh so easy and mine have been perfect using press+peel.you can buy the same lamintor at Staple's "GBC CREATIVE LAMINTOR" just when you buy a kit from Pulsar you get pcb+foils to make decals which are pretty cool check it out
http://www.pulsarprofx.com/DecalPRO/.../Overview.html

 

The GBC CREATIVE LAMINTOR has been discontinued. The replacement is the GBC H210.

I watched the decal video on the Pulsar site. Neat stuff.