PCB making at home - paper type?

[David G4EBT]

I’ve been making PCBs for more than 25 years using a home-built light box, I’m geared up for that, but were I not, I’d buy a cheap laser printer and use the ‘iron on’ technique rather than UV, which would save a lot of faff and expense of the UV method.

The laser ‘iron-on’ technique - which uses either glossy photo paper or glossy scrap paper torn from magazines - has gained popularity as it’s much cheaper and quicker than using a UV light box. The laser method can be likened to the ‘press ‘n peel’ process, and for anyone unfamiliar with it, the following info might be of interest, but I stress that I haven’t tried it myself:

Using glossy photo paper and a laser printer:

The PCB layout is printed onto glossy photo paper then ironed onto plain PCB. Remember to reverse the image before printing or you’ll have a back to front PCB, just as you would with any press ‘n peel method. Most drawing programs and programs such as Photoshop have a 'flip horizontal' function. (Print a test page of the design on normal A4 paper to make sure that it’s the correct size).

You iron the printed glossy paper firmly onto the PCB, then soak the paper in hot water until it falls off, leaving the printed design on the PCB, which you then etch in the normal manner, having made sure of course that there are no cracks in the layout, which is always a risk with any iron-on method.

There is a wealth of information on internet about this technique – here’s a link to one such source: http://homepage.eircom.net/~ei9gq/pcb.html


The ‘scrap glossy paper’ laser printing PCB technique:

Rather than buy gloss photo paper, some constructors use scrap glossy paper torn from magazines, cut to A4 size, which they claim gives superior results than photo quality paper as the water soaks in better and the paper quickly disintegrates away from the PCB.

It’s claimed that the perfect paper should be glossy, thin, and cheap. The kind of stuff that looks shiny when new but quickly turns into pulp when wet - eg, paper used for most ‘junk-mail’, travel agent’s brochures, newspaper magazine supplements, and so on.
If moisture on your fingertips is enough to feel a sticky sensation while touching the gloss coating on the paper, it should be OK. It doesn’t matter that the paper has print on it – that won’t affect its performance.

When you put the paper through a laser printer it electrostatically deposits toner onto the paper surface, and when the design is ironed onto the plain PCB, the printed PCB pattern adheres to the surface of the board, but the colour-fast printing ink on the magazine paper does not. That said, heavily printed paper should be avoided - pages with normal-size text on white background are best, and any blank areas are better still. Although the printers’ ink usually doesn’t transfer on the PCB, it’s said that heavy print of headlines may do.

There’s lots of info on internet about this 'scrap glossy paper technique. Here’s one such link that might be of interest: http://www.riccibitti.com/pcb/pcb.htm

As this thread is specifically about "using a laser printer and the type of paper to be used to make PCB artwork that can be transferred to a bare PCB using a household iron", I’ve confined my comments to that topic. In another posting I’ll outline my own experiences of printing, developing and etching PCBs with UV techniques.

Hope that's of interest.

David