inkjet printing

The ink beading up is a wetting problem.

It could be the ink surface tension... It could be the transparency has a low surface energy. Or combination of..

Then there's the matter of printing thickness.. Home inkjet printers may not deposit ink thick enough to create needed light blocking. Or it could be that the pigment size is not small enough or the ink concentration is not high enough or combination of...

So...I'm saying ..the nature of the materials are really just asking for trouble with dark precise printouts.

Here's my guesses at fixing:

1)Find the blackest inkjet refill ink. 2)Maybe research fluorochemical surfactants to add to the ink for improved wetting. (expensive and a bit smelly..) 3) Find a transparency material with the highest surface energy. Or use a coating with a high surface energy.. I spotted somewhere there's a modified acrylic.

Verify everything above... It's not really my area and there could be errors..

D from BC

Wow, I just found some old transparencies and did some experiements and stuff. It printed almost perfectly.

It seems like it is the transparencies. I have some that came in a box from my mother and actually have some mixed together so I do not know where the ones that actually work very well came from. They have a yellow hue to them and I printed on the rough side of it. The rough side is pretty rough compared to all the other transparencies I have and this might helping it. I have yet to print on the smooth side as I only have 4 of those and don't want to waste them.

But it seems its definitively the transparencies. (The printer may have something to do with it of course but I'm u sing an HP 6110 and its pretty standard printer)

Just wish I knew what these transparencies are. The yellow might be from being old or because they are "special" in some way.

BTW, these transparencies have little pits or bumpbs in them on the rough side about 2mil in diameter and randomly spaced about 15-20mils. Again, I do not know if the side matters in this case or not. Next time I print I'll try to remember to try the smooth side.

On a sunny day (Fri, 19 Oct 2007 05:44:13 -0500) it happened "Jon Slaughter" wrote in :

No the side matters. Those transparencies are specific for inkjet, I bought some in the local supermarket, and the box was marked 'inkjet', the rough side is there to accomodate the ink. Still sometimes I have to run it through 2 x to get sufficient black (Epson R200).

Ok, I figured it out. There is a coating on the back side. It is becomes sticky when it gets wet. So this seems to be what is required to use inkjets with transparencies. I guess this means you have to buy the ones specifically for use in ink jets because they have this coating on them.

Yeah, I see that now I guess. As I mentioned in another post they have a sticky coating on them. I assume that is probably specific to inkjets. Since I don't know if those transparencies that worked was for inkjets but chances are it was. As far as I can tell the ink doesn't really dry well on the laser ones so I guess the coating helps absorb some of the water in the ink to help dry it out but also helps it from beading up.

The coating as relatively dark but it could be better. Not sure if there is an easy fix for this(chances are running it through twice will ruin the details?)? Maybe higher quality transparencies or specific printer settings(I'm sure one could get thicker ink but not sure if that is a real solution or not).

On a sunny day (Fri, 19 Oct 2007 07:00:04 -0500) it happened "Jon Slaughter" wrote in :

Yes, depending on the printer perhaps, the old Epson 460 smears out. so let it dry a bit before you stick it in again. Small position variations can be a problem with small traces too. Last series PCB I just had it done, saves a mess with chemicals too.

I have got a volume ink printing system for the Epson now, I have not tried this with transparencies yet: See it working here on the R200:

Using it mainly for DVD labels...

is becomes

to use inkjets

ones

on them.

if you visit local "office superstore" they will have a vast array of transparencies, most packages will indicate the suitable printing technology {laser jet , ink jet} and some will further specify ink jet printer brands probably due to the different types of inks used {water resistant, water based, etc}

hth robb

I didn't realize there was such a huge difference and since several previous threads were talking about how poor they are I figured that it was something else. I think I'm getting pretty decent results. Its not perfect but I think it will easily do its job and easily beats having someone else do it.

Then you're using the wrong kind of transparency media - it needs a special coating to hold the ink.

Good Luck! Rich

Yes, the yellow ones are coated, and old. When you print to the smooth side, you won't waste the transparency, because the ink will just wipe off with a little water or isopropyl.

Good Luck! Rich

You can touch them up with a drafting pen and india ink, once - when you wet-erase the ink, it takes off the coating with it, so use care. (you can actually scrape the ink off around the edges, but then the clear spot won't take ink any more.)

Then again, my info is about 30 years old, when I used to do layouts with tape and peel&stick pads.

Cheers! Rich

Mega Electronics here in the UK sells JetStar Premium film that works very well with my HP inkjet. Ordinary Jetstar works with Epson printers. I get excellent results, down to 8 mil tracks or less. Farnell stocks Jetstar, so it is available worldwide.

Leon

There's "laserstar" too, the equivalent for laser printers. It works well for PCBs, down to at least 0.2mm track/gap.

--

John Devereux

I just got finished etching my board. I got very good results with 10mil tracks. Everyone one is perfectly defined. The only problem I had is that I didn't prehead the etchand and my bubbler wasn't working well so I agitated by hand and it left a lot of the very close pads together for IC's on one side of the board. (I got a bit nervous about leaving it in to long when I probably should have left it in for 20 more seconds... I looked at the board and at a glance it looked very well so I thought it was all done). I cut them with an xacto pretty easy though.

I figure next time I might try smaller tracks and test some different transparencies.

yeah, I used sharpie on a few of the pads that had a slight hairline crack in them. Everything turned out really well for my third time(and first using

10mil lines instead of 40mil's). Actually I was quite supprised at the results as all the 10mil tracks turned out perfect.

I wonder if one could apply the coating that transparencies use on to a copper board and print directly to the cooper with a modified inkjet? similarly,

On a sunny day (Fri, 19 Oct 2007 21:49:28 GMT) it happened "Jon Slaughter" wrote in :

Seems to me that the Epson R200 and similar, that can print directly to DVD, should also print to small PCBs. Have not tried it, but maybe I will one day. The width of a DVD is about 120mm, so.. nice round boards :-) But now you have to print and check the printing for every board.

I've done experiments feeding flex circuit copper foil on kapton through my laser printer. Some success but inconsistent for some mysterious reason. See news achieves..I've posted this..with links to photos.

D from BC