Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Transparency film

Status
Not open for further replies.

zachtheterrible

Active Member
The transparency film that I am using from MGchemicals does not work correctly. It has little holes in the traces where the toner seems to not have stuck properrly to the sheet. For now I am just printing two transparencies and laying them on top of each other, but has anyone had this problem?

btw, it is heat-stabilized transparency for laser pritners.
 
Zach - you may have already done this but consider contacting the supplier or mfr and describe the problem. Do this if you are using their product as intended. They might be able to help find out what's wrong - even if it is to realize that the product is defective. Many (but sadly not all) mfrs are only too happy to help. In return this helps them improve their product or possible to direct you away from their product (toward something more suitable). Just a thought - and if you do get good response share that too.
 
You don't need to use special transparency sheets like those, as a matter of a fact, its usually best not to. If your printer manual says what kind of transparencies to use, then use that kind. If not, just use a generic type for laser/bubble jet or whatever type you have. Its also cheaper -- around $20-30 for 50 sheets.

As for holes and cracks, I've never been able to get around that. I've tried several types of printers and sheets and the results have more or less always been the same.
If the traces are large enough, they can be fixed with a resist marker, or what I usually do is as you said, use two copies. If the artwork is small enough, I just print them both on one sheet.

If your artwork has tracks and spacing equal to or greater than 14 mils (16 or 18 is better) then you can use plain paper. Some kind of thin paper (like tracing paper) would probably work better, but I never tried it. The trick is to make the paper wet before applying it to the board to make sure the surfaces are properly mated. I tried this once out of desperation and the results were good. A thinner paper should allow you to use smaller traces and spacing.

I also use a drop or two of water to mate together transparencies -- it works more reliably than tape and makes perfect alignment easier.
 
I guess ill look into other types of transparency paper. Sadly my printer is a very old used one that I got from a friend who got it from someone who didnt want it so i dont have any manuals. :lol:
 
I've used Clearprint drafting paper (also called drafting vellum) to make the artwork for many of my PCBs. It's usually used for manual drafting so that diazo blueprints can be made from the original drawing. It's a translucent paper made from 100% cotton. I used to [try to] use the transparency film, but I had the same problem you're having, sometimes worse. I think the laser printer/copier toner doesn't stick to the film in the same way it sticks to paper because the film is much more "slick", that is, the paper has more surface for the toner to melt into when it runs thru the fuser. You might notice that sometimes the toner just flakes off the film, if you bend it.
Actually, I used the vellum one time as an experiment, and it worked really well. I thought if the UV from the diazo copier would shine thru the vellum, why not try it for PCBs? I ran a piece thru the printer and found that the traces didn't flake off as easily as the film. Then I made a PCB with it (had to lengthen the exposure time) and it worked well. After that, I began to use vellum almost exclusively. I've probably made more PCBs with vellum than with any other kind of artwork. This vellum isn't super cheap, but then neither is the film. And it works for me.
JB
 
One type of film I was using (I believe they called it "Tek 200" or something like that) had a similar problem. Things improved when I took the time to wipe down the side that was to take the toner with isopropyl alcohol and then dry it with a clean cloth or lint-free towel.

Dean
 
Did you buy the RIGHT transparency?

There are different kinds of transparencies for different applications. Since you use a laser printer, buy a transparency that is best suited for laser printers. Don't buy a transparency meant for inkjet printers because it won't work well in your printer.
 
Yup, mine is heat-stabilized it says.

One thing im going to try experimenting with is clear tape :lol: Whenever i print something, i print it on regular paper first, then i cut out a small piece of transparency paper and tape it over where it was printed on the piece of regular paper then run it through the machine, instead of running a whole sheet of transparency through. Anyway, a little bit of toner got onto the scotch tape and it was PERFECT! The toner stuck to it just great. Unfortunately all I have is small pieces of tape so ill have to look for bigger pieces and give that a shot :lol:

jbeng, that sounds interesting, how much is it?

Dean, i was thinking of somehow cleaning it. Is Isopropyl alcohol the same as regular rubbing alcohol?

Eventually I think Im going to try and modify my laser printer to print right onto the board :lol:
 
I just tried something that worked somewhat, I scuffed the film with a 0000 grade (four zeros) steel wool. The toner did stick better but not perfect. When I get around to buying a coarser grade I'll have to try this again.
I think that it may be a too smooth surface thats causing the problem.
 
pandemonium, that is a GREAT IDEA!! duh, i cant believe i didnt think of that.

ill try that next time.
 
Zach - here's a site where I found the cheapest price for the stuff. Here, it comes out to about 13 cents per 8 1/2 x 11 sheet (+s/h) ... not exactly cheap, but it could be worse.
**broken link removed**

They might have a similar product at your local art supply store. (I looked on Staples website and they have Staedtler brand vellum). I've also used "National Printfast 80M" vellum, works the same. Don't see any reason why the Staedtler wouldn't work.

I also saw on Clearprint products website that they produce vellum paper for an application almost exactly like ours (silkscreen manufacture). Don't know anything else about it though. Here's that link:
**broken link removed**
zachtheterrible said:
Eventually I think Im going to try and modify my laser printer to print right onto the board
That sounds interesting, but I don't know if it would work or not. It might be easier to modify an inkjet printer to print directly on the photosensitive PCB material (making a photomask) then exposing that. When you develop it, it wouldn't matter if the photomask washes off, the PS coating would already be exposed anyway. Then just etch as usual. Tough to make double-sided boards that way though ...
Jeff
 
zachtheterrible said:
Eventually I think Im going to try and modify my laser printer to print right onto the board :lol:

That sounds like a very ingenious idea, sorry to burst you bubble. But that wont work. Copper conducts electricity. Paper doesn't, transparencies dont either. The toner is picked up by the paper/transparency because of static electricity. Copper will simply dissipate the static, and you'll print nothing but a hot (and blank) PCB.
 
I was afraid of that pike but i wasnt sure . . .

Guess ill just stick with transparency for now, my results are getting better and better :lol:

jbeng, that stuff sounds pretty cheap (13c a sheet), a lot less than $5 for a pack of 5 transparencies from MGchemicals.
 
i took a scotchbrite pad to a transparency and it came out BEAUTIFULLY!!!!!!!!! :lol: . Looks like ill be sticking with my transparencies till i run out, then ill check out the vellum, but that might not be for another year :lol:

Thanks everyone
 
Status
Not open for further replies.

Latest threads

Back
Top