silk screen technique for homemade pcb

I’ve been working on getting a nice homemade silkscreen technique for my PCBs. I have never had good results with toner transfer. I would like to know what you think of my latest efforts and if I should move forward with this. Please note, this is a first attempt and not all of the holes/components line up with the silk screen. I just wanted to see if I could do it.

silk.jpg

Doesn't look too bad. Little smudging here & there, I assume will be better with more attempts.

As an overlay, it looks like you're already getting close to something looking quite professional. With a bit of practice I'm sure you'll be able to get more consistent results. I'd be interested to see the methods you're using. I'm sure I'd find it most educational.

Using it as a method to apply etch resist will probably prove to be much less practical. (you may prove me wrong)

I think the toner transfer method is highly dependent on your printer and the nature of your toner. My OKI laser produces a really glossy black and on glossy paper it transfers particularly well. (passing it through a laminator about half a dozen times does most of the work) Then to remove the paper, I put it in a tray with water (and a dash of dishsoap) just gently rocking now and again. Eventually the paper just falls away.

Hi, I agree as a first effort it is very encouraging, even at this quality it would be fine for showing input and output sockets and IC alignment. Good result.

Tom...... :)

I can definitely getting it sharper looking, but it is very readable right now. I use positive resist/UV for making my board traces. I have tried using toner transfer using an iron to add silkscreens, but this has always given poor results for me. Is a laminator that much better? Am I the only one having issues with this method?

To make my silkscreen I print the image on a transparency. I then burn it onto a silkscreen material that allows the ink to flow where I have the artwork. I then adhere it to the board and run the ink over it.

I was thinking of making a batch of silkscreens and pre-packaged ink for others to do the same. I just don't know if its worth my time for something that most people probably won't want.

I have to say that the board looks very nice and the components are perfectly readable.

[quote author=imsmooth link=msg=1944265 date=1414847210]
Is a laminator that much better?  Am I the only one having issues with this method?

I can’t say. The very first time I attempted this method, as I collected my print from the printer, the laminator was sitting right there, so a light went off in my head so I tried it. I still give it some gun with an iron afterwards. I’m not even sure which bit is doing the business, the laminator or the iron.

imsmooth:
To make my silkscreen I print the image on a transparency. I then burn it onto a silkscreen material that allows the ink to flow where I have the artwork. I then adhere it to the board and run the ink over it.

I’m only familiar with the UV etch resist varnish. This would produce a negative image (as it’s the exposed parts that get dissolved by the Caustic soda when developing). Do you use something different for your silk screen process?

Just another idea. Have you tried using your silk screen process to produce a solder mask?

I could use this for the mask, but I don't know how easily I could get the ink off for soldering. I have great success with the positive photoresist, so I just use that.

imsmooth:
I could use this for the mask, but I don’t know how easily I could get the ink off for soldering. I have great success with the positive photoresist, so I just use that.

Well that’s the idea of using the silk screen rather than just painting the whole board. You’d leave the solder mask OFF anything that needs to be soldered. It also reduces solder bridging. Especially good when you have finely spaced items like QFPs

imsmooth - You may have better results if you print off-contact. That is having the screen above, not touching, the board slightly. Thus, the only area of the screen that comes in contact with the board is the area under the edge of the squeegee as you make a print pass. Also, make sure you are using a sharp squeegee held at about a 45 degree angle.

KenF - I recommend using sign vinyl rather than glossy paper paper for the toner transfer. The result for me is that ALL of the toner gets transferred without having to use water. Any local sign shop should have scraps to try it out. It's really cheap too.

  • Scotty

Can you put sign vinyl trough a laser printer?

ChilliTronix: Can you put sign vinyl trough a laser printer?

I once had a very bad experience using "transparency film for lasers" in a laser printer. It melted! This was AFTER the printer owners has specifically told me "don't use transparency film in that laser, it will melt" I've had an aversion to putting anything remotely plastic into a laser printer ever since.

Looking back, I suppose it's possible that it was a wax sublimation printer, (even though everyone called it a laser) yet my paranoia remains.

I use vinyl (specifically Oracal 641, matte gray) for toner transfer and print it on Samsung ML-1640. The vinyl is not melting. The price for me was about $10 for 1,4 m2 (that is enough for quite a bit of PCBs).
I get almost 100% of toner transfered to the copper. After ironing (thate takes less than a minute), I put the still hot board under the running water and the vinyl falls off effortlessly.
To be honest, I think my printer is the weak link, not the vinyl.

Shpaget:
I use vinyl (specifically Oracal 641, matte gray) for toner transfer and print it on Samsung ML-1640. The vinyl is not melting. The price for me was about $10 for 1,4 m2 (that is enough for quite a bit of PCBs).
I get almost 100% of toner transfered to the copper. After ironing (thate takes less than a minute), I put the still hot board under the running water and the vinyl falls off effortlessly.
To be honest, I think my printer is the weak link, not the vinyl.

Interesting. Is it possible to clean the vinyl up and re-use it, multiple times?

No. At least not with the method I use. This vinyl is self adhesive. I stick it to the printer paper on the location where the printer prints the traces. I then cut the paper a bit so I have enough to wrap it around the raw PCB so it doesn't move during ironing. After pouring water over it it's pretty much ready for the trash bin. It sometimes sticks a bit to the rough edges of the board and stretches if still hot. I don't think it's worth the trouble to reuse it.

Shpaget:
No. At least not with the method I use.
This vinyl is self adhesive. I stick it to the printer paper on the location where the printer prints the traces. I then cut the paper a bit so I have enough to wrap it around the raw PCB so it doesn’t move during ironing.
After pouring water over it it’s pretty much ready for the trash bin. It sometimes sticks a bit to the rough edges of the board and stretches if still hot. I don’t think it’s worth the trouble to reuse it.

Oh dear. Adhesive AND plastic. I don’t think I could summon up the courage to let that near my laser :slight_smile:

I haven't noticed any glue going places it shouldn't.

I use the photo positive method for the foil layers and have used Press and Peel for the silk screen layer.
I don’t do the silk screen any more since I only have an Ink Jet now.

http://www.techniks.com

The method Shpaget uses is also my method. Works good. No problems. - Scotty

KenF: I once had a very bad experience using "transparency film for lasers" in a laser printer. It melted! This was AFTER the printer owners has specifically told me "don't use transparency film in that laser, it will melt" I've had an aversion to putting anything remotely plastic into a laser printer ever since.

Looking back, I suppose it's possible that it was a wax sublimation printer, (even though everyone called it a laser) yet my paranoia remains.

I had a similar experience with a laserjet 2

Did you find out why ? Do some printers hava hotter fuser than others ?

Boardburner2: Did you find out why ?

No. They never kept in touch.