I'm wondering what methods you folks used to make your own circuit boards for your CNC machines... I am very intersted in building myself a PICstep driver, but I have had some pretty poor results with many techniques of creating circuit boards.... There has to be an easier way for those among us who are broke to produce our own PCBs.

Following are the results i have had with different methods of PCB making.

Toner Transfer:
I have tried this methods staples brand picture paper, and have had very poor results. I'm not sure if the iron that I am using to transfer the toner is hot enough (Although I suspect it is). Also, there is a possibility that the laserjet xerox that i am using to produce my artwork is not fusing enough toner to the paper to get very good results... I have tried immersing the board in warm soapy water for ten minutes or so, and then proceed to peel the paper away from the PCB by using a toohbrush, and eventually, i end up with most of the paper off (except for the paper still sticking to the toner)... But I still have a problem in that some of my traces always end up damaged.

I have also tried transfering from kinkos' transparencies.... This method actually worked better than i expected... I have not heard many people speak of it using transparencies for toner transfer, but this method, if it can be proven to be effective, is a lot quicker than dealing with picture paper. However, the transparency has a tendancy to melt if the iron is kept in one place for too long, or the image can get warped and distorted if the transparency gets too hot as well.... There are a few tricks to even get this method to work at all. You have to pull the transparency away from the PCB while it is still very hot, so you may end up burning yourself. If for some reason the toner is not dense enough on the PCB, or part of the toner did not stick because it was too cool, it may come up, and you may have to use another transparency placed precisely over the top of the toner that did transfer to get it to work.... The upside to this method is that it seems to work with finer traces than the picture paper transfer method.

I wish that I could afford to use techniks' "press n peel blue" transfer paper... But this is way to expensive for me to afford (I am a poor college student). Also, they do not sell this paper near where i live.

Photo Etching
After messing with the toner transfer method for awhile, I decided that perhaps it would be a good idea to give photo sensitive boards a try... I purchased some boards that were pre coated with the photosensitive chemical. They were a bit more expensive, but i figured that if this method worked well, i would just bite the bullet and give up on toner transfer forever. This method requires additional consumables... I had to purchase the developer, that would make everything but the artwork water soluble, and I also decided to buy ammonium persulfate to use as my etchant, because it is supposedly better for close traces (as exist on the PICStep boards). Also, I purchased a 200W incandescant bulb, and a desk lamp with an adjustible arm which I intended to use to expose the photo sensitive PCB with.... It turns out this this whole method was a waste of time... I either over-exposed or under exposed the PCB.... Or perhaps the 2 transparencies I used stacked upon one another did not act as a proper mask (I doubt this). I exposed the board for perhaps 10 minutes under the incandescant bulb, which was 10 inches away from the board.... Another failing of this method may be the fact that i used the incandescant bulb. I have heard of other people just exposing their board under sunlight, but they never mentioned how long they exposed it for... I have also heard people say that incandescent bulbs worked just fine for them... Perhaps those people had higher wattage bulbs, or they exposed for much longer than the standard time.... In either case, i had to scrub the board and just use it as a standard copper clad board.... I bet this method would have worked perfectly if i had used the reccomended flourescent bulbs to expose the board with.... But this would have meant spending a $$$ on an UV exposure unit or building my own exposure unit using germicidal UV bulbs... Both of these cost quite a bit of money and were not really a good option. Especially considering the fact that i live in a small apartment, and the girlfriend probably wouldnt appreciate any more of my "mad scientist" junk laying all over the place.

Ammonium Persulfate
As sort of a side note, has anybody really had any luck with this stuff. I hear people say that it works a lot better than ferric chloride, but I could not get mine to work very well, even when it was agitated by hand and heated...

Xylene
I read somewhere that somebody was using colorless blending markers containing xylene to chemically transfer the toner from the paper to PCB... I have tried this method and am under the belief that the person could never have gotten this method to work well. First of all, the toner doesn't tranfer to the copper in a dense enough fasion that you could etch with FeCl, and second of all, I have a problem with the artwork smearing on the PCB... Perhaps there is something I do not know abou this method. I have tried using it in conjunction with toner transfer with no success. (By bleeding the blending marker through the back of the paper after using the iron)... Also, xylene is very powerfull stuff, and it is hard to avoid breathing it in. I am sure that it is not very good for your brain cells. ...

(Xylene would probably be a great way to print words on the top of your PCBs where the through-hole components are mounted!)

Ferric Chloride
Good stuff... Cheap and available in most every town... Something that actually works well!

Transparent Laquer
I have been concerned about how to prevent the copper traces from oxidizing... I cannot afford any of the expensive chemicals from MG, so I gave this a try (This is before I understood flux and tinning). The laquer that i bought from wal-mart works pretty well... Although you cannot solder through it (I hear you can do this with some laquers)... If you don't plan on making any more modifications to your board, and do not feel like 'goin through the effort of tinning your board, i would reccomend purchasing some of this stuff.

I have also just today heard of SMT screens which are used for applying solder paste before you send your boards in the reflow oven... I wonder if you can order stencil's like this for applying PCB traces to the board using wax, or perhaps some sort of spray enamel. If anybody knows that would be great.

I have heard that magazine paper works well for toner transfer. I hope to give that a try this weekend. Hopefully they won't catch me putting the magazine paper through the xerox machines at my local kinkos. :wee:

So... That is my experience with making circuit boards so far. Man! Talk about a pain in the a*$. I have learned a lot through trial and error... And for some reason I still cannot justify sending my art to a board house.... I guess i'm just a renaissance man at heart.

Perhaps some of you have some insight on the methods mentioned above, or have another exciting technique for getting the job done.

-bkinman
(first real post!) :banana: