Cheaper alternative to Press 'n Peel??

[zjokka]

hi all,

I thought I wouldn't get to this etching business, considering that PnP paper doesn't seem to be available on the European mainland. Found a source in the UK, the the price is putting me off. Not that I cannot afford it, but still, it's a certain type of plastic film.

So I stumble upon the below page, where it is explained how to make PCB the P'nP way, but with much cheaper by using Picture Paper:

http://www.fullnet.com/u/tomg/gooteepc.htm

Has anyone tried this already?
ZJ

here's a a part, more at the website, once you get past the "15 minutes of fame paragraphs"   

Making PCBs:
Introduction:
You can easily make your own high-quality PCBs (printed circuit boards), from a laser-printer or copier (but not inkjet) printout of the desired copper pattern, using an ordinary clothes iron, and, most-importantly, the correct paper type. You can have finished boards in less than an hour, including printing, preparing the copper board, transferring the pattern, removing the paper, etching, and drilling. You can also use this method to print the component markings onto the non-copper side of a single-sided PCB. AND the COST is VERY LOW.

[FAQ about using INKJET printers: I've been getting a lot of email, asking me if an INKJET printer can be used to print the patterns, for this PCB-making process. The answer is: NO! The toner in laser printers and most copiers is made mostly of PLASTIC, which resists the acid that eats away the copper that doesn't have any toner on it. Inkjet printers use INK, not toner. And their ink is typically NOT a good etch-resistor, at all.]

There are many methods that can be used to make a PCB. Most of the traditional methods involve applying a "mask" over the desired portions of the copper, and using an acid or etchant that can't easily penetrate the mask material to remove the unwanted copper from the remainder of the surface, although direct mechanical milling-away of the unwanted copper is also sometimes used.

Most commercial printed circuit boards seem to be made with a screen-printing process, for the mask. There are now available screen-printing materials that use a laser printout (or any black and white art), and a photo-sensitive screen material, that allow anyone to make a screen-printing screen, at home, with NO special chemicals and NO special lights (See http://www.cbridge.com, Circuit Bridge, San Jose, CA. Their "HiRes" product supposedly can clearly reproduce 4-point type.).

Another popular method, which also works with laser printouts, is photographic in nature: A transparent positive or negative image of the mask is created, usually photographically, and is used to expose, with a special light, a PCB coated with a photo-sensitive etchant-resistant material. That seems to be the preferred method, for getting the best quality, finest traces, most repeatability, etc, at home, or in a low-volume, prototype-oriented situation. However, for many applications, and for the lowest budgets, the method described below can give results that are at least ALMOST as good, for many applications, for less money and maybe more quickly.

The reason that this toner transfer method works is that the toner in most laser printers and copiers is composed mainly of PLASTIC. And the etching chemicals (acids) that are used will eat copper but will not eat plastic.

Very small trace-widths are said to be achievable with the photographic method mentioned above. I have not tried any traces that were less than 0.01-inches wide, with the toner-transfer method, described below. However, I have had absolutely NO problems, at all, with the 0.01-inch (10 mil) traces. So, I assume that the achievable lower-limit is MUCH less than 0.01-inches.

The Toner-Transfer Method:
The type of paper used is the KEY. Almost all types of paper will work, to some degree. But there are usually two problems: 1) Print quality: Some papers print with tiny (or large!) pinholes in the toner, which greatly degrades the quality of the finished copper traces. 2) Removability: The paper has to be able to be removed, relatively easily, without causing any damage to the pattern on the copper. Glossy, coated inkjet-printer-type paper has been found to work very well, since the coating on the paper will usually separate from the paper, especially when soaked in water.

I've recently tried MANY different paper types, and have finally found one or two that give excellent results for making PCBs (printed circuit boards) via a laser printer or copier printout and the household-clothes-iron toner-transfer method.

I tried almost every glossy paper type that our local Staples office-supply store carries, plus the "house glossy" from our local printer. Most either had "pinholes" in the large black areas, or in the vertical (parallel to the print path) areas, or had removal problems after ironing. For example, the HP Premium Photo Paper had perfect printing, with no pinholes at ALL, ever. But, it was almost impossible to remove, even with long soaks in soapy hot water, or in alcohol, and often pulled the traces off with it. Anyway, I finally found a good paper that's always free of pinholes and still removes fairly easily. It also leaves extremely strong toner/traces on the copper, which can be scrubbed fairly hard with a toothbrush, or rubbed very hard by fingers, without being damaged.

(UPDATE: See farther below, for the correct paper type that is currently available.) I had originally found that this paper worked well: the JetPrint "Graphic Image Paper, Gloss Finish", Heavy Photo Paper (their product # 02735-0), for INKJET printers, made by International Paper Co, which I bought at a Staples store (They also have a website, at http://www.staples.com). They also make a product called JetPrint "Multi-Project Paper, Gloss Finish", Medium Weight (their product # 07033-0), which almost falls off the board by itself, after soaking for 10 minutes. Alas, it sometimes has pinholes. (I use an older HP LaserJet 4. Your mileage may vary...)

However, the JetPrint "Multi-Project" paper *IS* PERFECT for doing the component side markings of circuit boards ("silk-screening"), and anything else where etching isn't required, such as metal (or hard plastic?) instrument panels. And the Multi-Project Paper is still available, as of 06/15/04. WalMart usually has it in stock.

THE BEST TONER-TRANSFER PAPER IS...
The very BEST paper I've found (basically PERFECT!) is sold as Staples "Picture Paper". It's available at Staples "office supply" stores, in the USA. (And also from their website, at http://www.staples.com .) [I almost can't believe that I didn't try that paper, before. It's one of the very FEW that I didn't try...!]

Below are the details, for buying the correct paper (at www.staples.com or at a Staples retail store). At the Staples website, search for the "SKU" (item number). At a Staples store, ask an employee to help you find the Staples Picture paper with the correct SKU. [Many thanks to Woody Eadie, for providing all of these details via email!]

[O]

That's the way I etch and it works 100% of the time. Keep this in mind... a lot has to do with how well the copper is prepared. Even with PnP, if your copper surface isn't prepared well, you'll never get good adhesion.

"Prepare twice, iron once"
-Ancient Mexican Proverb

(well not really )

[zjokka]

That's the way I etch and it works 100% of the time.

thanks man,

I was gonna try this anyway, but then my question is -- do you use that particular brand of paper? It shouldn't matter, really, what brand, but Staples, around here is not available. In addition an update says Staples changed the type of paper under the same number and name.

should start trying really.

ZJ

[O]

I would think that any photo paper originally designed for inkjet printers should work (the glossier the better). It takes some practice to get the temp right, so expect a few "ruined" boards until you get it right. The boards aren't actually ruined, just take some thinner to them and the paper & toner should come right off.

I actually tried different types of paper and most of them don't release as well as the Staples paper does...

[geertjacobs]

considering that PnP paper doesn't seem to be available on the European mainland.

Try:
http://www.banzaieffects.com/product.php?productid=17509&cat=0&page=1