[Garbz]

Hi all

I've been making PCBs for about 3 months and i've made about 5 each with a differnt method. However none have been perfect so i put the question out to all you custom builders, how do you make them?

I used to try and use injet paper but that has always lead to trouble and the most recent pcb i've made was downright impossible because of the small traces. My current method is a follows:

• Print the traces on the toner transfer film with a $30000 Konika printer at dad's work (it has an awesomly even coverage)
• Iron the transfer on with a cloths iron set between the linnen and cotton setting
• Quench the board in cold water (wouldn't this crack the copper)?
• Peel off and start the painful process of scratching away excess and touching up lines with a PCB marker

I've appended pictures at the bottom of this post.

My other question regards how you drill your holes? I've found the holes are easier to drill after the board has been etched. The copper seems to guide the drill to the centre of the hole automatically, however for some of the smaller holes this had the unfortunate effect of ripping the traces off the board. Even if only half the trace is missing around a hole the soldier will not gob around the part leg. But if I drill before hand how long will my drill last? :S

Anyway how do you make yours? Also what's the cost of it? The toner trasfer paper costs me about $45AUD ($30US) for 5 Letter sized sheets.

The black on the blue toner transfer paper shows where it didn't transfer properly.

In the centre right of the image next to the 3 holes you can see a hole drilled through without a trace on it. I've since worked around mounting the heatsink but i think next time i'll predrill before etching.
Also thoes horrizontal traces near the bottom aren't all that straight.

 

[tangent]

Quote:

how do you make them?

I use the photosensitive board method. I find that it's easier to get fine resolution, and you don't have problems with the toner lifting or the transfer paper not coming off the board easily.

One nice thing about this method is that you can file the acetate masks for running the same board again. With the toner transfer method, you burn a sheet for each board.

Quote:

how you drill your holes?

With a Dremel in a Dremel drill press using carbide PCB bits. The bits have 1/8" shanks that work with the standard Dremel chuck, and they're available in very fine size increments. I get mine from McMaster-Carr.

Quote:

this had the unfortunate effect of ripping the traces off the board.

Sounds like you need a higher quality of board. Traces shouldn't lift that easily.

Quote:

what's the cost of it?

Photo-sensitive boards are more expensive than plain copper-clad boards. Acetate sheets are probably cheaper than any type of toner transfer sheet, even if you double up the acetate for higher density. You can get away without buying an exposure lamp, but I'm impatient enough that I decided it was worth the cost to me.

On the whole, I suspect the photo-sensitive method is probably cheaper overall for me, simply because I don't have to re-do the work as often. And, to the extent that my time isn't free, I spend less time doing it so it's cheaper that way, too.

 

[Garbz]

i was considering it but i think for the volume i do the initial outlay of the riston stripper, developer, etc would work out waay to expensive.

What i'm mainly interested in is what paper people use for toner transfer.

I do have a Dremel and i use 0.8mm and 1mm dill bits which work for me. The traces ripping off is not traces as such but circles on the opposite side of the pcb used to fix components. I.e. when i solder through a gnd plane i solder on the top and on the bottom just to secure the component. I haven't as such managed to lift any connecting traces yet.

 

[Vladco]

You should look at http://groups.yahoo.com/group/Homebrew_PCBs/
You will find all the answers you needed espesially in links section.
Vladco

 

[MaxW]

I tried this once because I needed to make one board for a Fibre Channel T-card. I followed this giude:
http://homepage.tinet.ie/~ei9gq/pcb.html

This is obviously way more ghetto than both of you two but once I had done about 5, I got the hang of it and was very pleased with the results considering it only cost me about 10c for each sheet of photo paper. I didn't use an etching tank, I used a jar, like I said before ghetto.

Heres what mine looked like:

 

[Garbz]

hey max i'm using a very similar setup except that i had no luck with my photo paper so far.

Can you mention specifically what paper you use? Like Kodak premium picture with medium gloss or whatever? I've tried high gloss only to have it curl around the iron, and low gloss paper didn't transfer properly.

 

[Voodoochile]

I've been using the toner method for a while with good results. I have tried a lot of papers, and Burlington Semi-Matte photo works best *for me*. I know that subsonic has the exact same printer I do, a Laserjet III, and yet he did not have such good results. So I think it is quite dependent on the specific aspects of your particular laserprinter and paper combination. I'm sure the fuser temperature varies a bit printer to printer.

Sometime I will get off my arse and jump into photo sensitive boardmaking. I already have most of the stuff needed, either at home or work.

It really makes fine traces much better than the toner method. The toner method is fine for fatter traces though. I use a drill press for my holes, but only because I have one anyway... otherwise I'd also use a Dremel tool.

 

[Sal]

I've had fairly good success with the toner transfer method. You need to make a PCB layout with thick traces and I even make the solder pads larger in diameter with a smaller hole than the PCB software normally allows (Express PCB) by modifying the artwork in Adobe Illustrator.

I thought the blue toner transfer paper was too expensive so I used regular copy paper. The trick I found that helps get the toner to release better is to copy the laser print in a photocopier and then run the sheet back through the bypass feed but with a blank sheet of paper on the glass. The reheating seems to help melt the toner better or something.

Anyway, the thin copy paper seems to disintegrate fine after soaking it in water and I go over it with a toothbrush to remove excess. I don't care if there is still paper residue on the traces as long as it doesn't make any bridges.

I generally reserve this method for single sided boards although I was planning on trying some double sided boards soon. In this case I use as few vias as possible and favor jumpers over complicated traces that use both sides.

Here are some pictures:

 

[Garbz]

i don't know what i'm doing wrong but i can never get small traces to work with normal paper. There might be something to do with the iron and the way i'm re-applying it. But who knows. :|

One major problem i had using the paper method is that the paper didn't come off from the toner. Instead it ripped and made a mess. The easiest way i found to get the paper off was to use acetone on a cottonbud however this had the disadvange of screwing up my traces too.

My goal is in a few months to build something with SMD parts. I already have all i need including low-wattage soldering pencil, but it's all for not if i can't cheaply and effectively get the traces to sit so close next to each other. Using a touchup marker in this case would be bad too !

 

[MaxW]

Quote:

Originally Posted by Garbz hey max i'm using a very similar setup except that i had no luck with my photo paper so far. Can you mention specifically what paper you use? Like Kodak premium picture with medium gloss or whatever? I've tried high gloss only to have it curl around the iron, and low gloss paper didn't transfer properly.

I used real cheap stuff, its only a tad more glossy than normal paper. It doesn't feel plasticy at all. I cant remember what brand it was but I bought 10-20 sheet packs that were ferari red.

I still had a couple of failed ones but after a bit of practice it was OK. Just have to remove the paper after soaking very carefully and make sure it stays very wet while removing it so it doesn't grip the ink and remove your traces.