PCB photo etch using inkjet?

If you're talking about the photographic process where a sensitized board is exposed to light with the artwork on a transparancy, then the inkjets typically don't get dark enough for fine line work. Laser toner is much more opaque than any of the inkjet inks I've seen so far.

JazzMan

Also there are methods that rely on the fusing of the toner to the board. Ex. PNP Blue.

ink doesnt dry quick enough consequently it runs or smudges edges I have done a board or two printing artwork to plain paper and exposing for a minute or so in sunlight , worked well but now use Laser printer and transparencies for development

Steve

--IIRC the trick is to take the inkjet rendering and photocopy it onto that special paper that can then be ironed onto a copper substrate to make the mask.

-- "Steamboat Ed" Haas : Woohoo! Cheney sez Hacking the Trailing Edge! : lawyer season's open!

Yeah, but I'm was going to use UV since I didn't have a laser printer. I didn't see any mention of not being able to use UV with inkjets ;/ Else why use UV? (spend !70$ on the UV exposure device and transparencies and stuff... kinda a waste if I have to use a laser printer anyways.)

Do you mean the UV wil expose through a plain sheet of paper?

if that was the case you could always run it through the printer a couple of times(although it might mess up very fine traces).

I read once that the trick to using inkjets with photoexpose is to print in green (using cyan and yellow inks), not the black ink, because those colors blocked UV the best. Print some color bars and do a test board to see which of your inks (or combinations of inks) block the most UV.

I tried printing the traces on a transparency with my inkjet and it turned out almost perfect. There were no smudges or anything and it looks pretty dark(it has a green hue to it though and I'm not sure if my printer is using the black ink completely or not.) I'd say its 99% perfect as far as the traces are concerned. There is a little "streak" about 1 mm long through one of the traces but that is easily fixed. I will go ahead and try it and see what happens. Hopefully the ink is thick enough to block the UV light. I might post my results if they are decent.

Jon

The ink washes off.

However, you _can_ use an inkjet if you copy it on an ordinary xerographic copier, since the toner is plastic; inkjet ink is just ink. (you _do_ have to heat-set it, however.) Laser toner will also work, i.e., if you print the pattern on a laser printer - they use the same plastic toner as copiers.

Good Luck! Rich

OK, wait a minute - we're talking apples and oranges here.

If you have a board that comes precoated with photosensitive resist, then anything that will expose a pattern will work, albeit if I was going to use an inkjet I'd get coated transparencies to print on, and print reversed; if I really wanted tight precision and only had an inkjet, I'd print it 2X or 4X, physically cut and paste the paper pattern, and take it to a photo shop.

If the PCB is just plain copper, then you'd use the laser printer toner or copying machine toner as the actual resist. Inkjet will _not_ work for this, because the ink is just ink; there's nothing to transfer. With laser or copier, you just take the sheet out, verify the dimensions, and lay it face-down on the copper and iron it on. You also have to print reversed when doing this.

Hope This Helps! Rich

So far so good. I was able to get the layout on perfectly. I could not place a "weight" on the transparency since the ink would not try. I have to cut the board to size and etch it. I was able to get about .008 trace width. Don't know for sure since I didn't use any traces smaller than 0.040 but my - sign's have a smaller than 0.01in so I guess its about 0.008.

So I guess everything is ok now. The etching should be routine(well gotta figure out the proper time). The next hurdle will be the drilling.

Jon

The etching went almost perfect as far as the traces are concerned. It was a little messy and the process wasn't perfect as far as efficiency and ease of use but it was cause the way I did the tank and the stuff I used. One thing I didn't expect was for the etchant to screw with the airator I used. It was one of those stone string things that let the bubbles through. The etchant ate through some of the stone for some reason ;/

The board itself is ok though. One of my G's(for ground) got ate through a little but everything else is ok.

Next thing is the drilling ;/ I figure this will be the toughest but if it goes like the others then it should be a piece of cake.

One thing I should mention though is that using the inkjet transparency method lets use reuse the transparencies pretty easy. You just was off the ink(I used the developer and it came right off. I'm not sure if it would work with the toner though.)

Jon

Yeah, tell us how well it comes out after washing off the coating. ;-P

FYI, the transparency film I've ink-jet printed on came with a special coating that retains the ink like paper does - bare mylar or acetate will just smear. But, I don't know if it unconditionally destroys the coating to erase or wash off the ink - try it and let us know, OK?

Good Luck! Rich

I just got finished drilling the holes. It seems like it will work. While I didn't do the best job drilling the holes I think its good enough. The main problem was the bits I were using just were either to big or to small. They were not standard drill bits but the ones that came with the dremel.

Heres a photo of it:

The large thick lines are 0.06in and the smaller ones are 0.04. Being my first pcb I'm supprised it went so well. Was expecting much more trouble. Most of the real trouble was seting up the etching and such as my home made tank was a little to big and the fact that it ate through my stone bubbler thing. Cleanup was a little trouble too. But it was definately not as much trouble as I thought it would be. I mean, for one 2.5x2.5 board it is but making several at once would be quite efficient except for the drilling. Hopefully my traces are right so I my circuit will work ;)

Going to try and tin it now then add the components.

Jon

Looks quite nice!

I think so too ;) That is for being my first time. I learned a few things along the way and I still came out of it with a usable PCB ;) Not sure why I was so anxious about doing it.

One thing I did learn is that you should remove the resist before you drill holes. Else it seems to make it awful difficult to tin.

Jon

A home tanning lamp makes a good cheap UV source. You may be able to find one at an estate sale of a skin cancer victim.

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

And get a smaller drill bit or two. ;-) Although, there are folks who recommend a dental bur. (burr?)

Cheers! Rich