Toner transfer release agents.

Hero999 said:

I think you're being too picky, you're not going to solder anything to the outside tracks, it's just part of the ground plain isn't it?

The fine detail in the middle of the board has transferred perfectly.

I tend to avoid putting traces in between DIL pins, unless there's a solder resist layer, as it's very easy to bridge them with solder.

I've often found that tracks near the edge don't transfer so well, it's an issue with the ironing not the paper. The solution is: don't put any tracks too near the edge of the board, it's considered to be bad practise anyway. It's different with planes since they're already thick enough any way.

If it bothered you, just touch it up with a marker pen.

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Thanks Hero999 !!
present one is from Elektor, as you can see.

Then i would try really thin lines choosing a ready art work, with same type paper. Etching is a separate issue altogether.

If anything will mess up it is the outside edge. I sometimes place a wide line around the outside of the artwork and trim it off prior to populating the board.

Hero999 said:

{snip}UHU make a wide range of adhesives, some are water soluble others are not, as long as the one you use is then I don't see why it shouldn't work.

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I now have just a little experience with glue.
My experience is that it must have two criteria namely being "washable" (meaning that it comes off with water) and it is a "gel". Gel makes it possible to spread evenly with a squeegee. These type glues (here in the USA) are usually clear with a slight tint of blueish / green.

White (school) type glues doesn't seem to work. And stick type dispenser can not be spread evenly.

3v0 said:

If anything will mess up it is the outside edge. I sometimes place a wide line around the outside of the artwork and trim it off prior to populating the board.

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Newer had this problem, probably because I always burnish the copper side edge of the board.

3v0 said:

Great work Rolf.

Is there any chance of making the glue work on something that passes light. Might make alignment easier for DS boards.

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Thanks.

Do you etch both sides of your DS board at the same time?

Rolf said:

Newer had this problem, probably because I always burnish the copper side edge of the board.

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I agree that a bad edge is the most common problem. There may be additional factors.

3v0

you can etch both if you want

ive done it both ways
if doing one side then just apply some paint to other unetched side.
etch then remove paint.
clean board then paint etched side.
I found paint to work rather well. you can see if you missed anything.

MrDEB said:

ive done it both ways
if doing one side then just apply some paint to other unetched side.
etch then remove paint.
clean board then paint etched side.
I found paint to work rather well. you can see if you missed anything.

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Thanks, that is good to know, I have newer done a DS board until now.
Have always got away with a few jumpers.

I want to start by saying there are several ways to skin a cat (make DS boards).

I drill my holes first with a CNC mill.

I apply toner to one side and mask the other with box tape. The tape can leak a wee bit around the edges so I like to have about 1/2 inch margin from the edge to the actual PCB pattern.

After the first side is etched I remove the tape and apply toner to the unetched side. Apply tape to the etched side and etch again.

I always etch the side with the fewest traces first.

The paint sounds more secure. The tape is faster if you are only doing one board (no drying) and does not plug my holes. I do everything but the drilling in my home office so less spraying is better.

The tape is a compromise but it does not effect the quality of the final PCB.

3v0

Here's my latest board etched using magazine paper.

I didn't bother experimenting with a release agent because I want the board done tomorrow and don't want to experiment but get a reliable result.

Here are some pictures.

1) The toner transferred to the PCB: notice how the clay has stuck to the toner giving it a greyish colour.
2) The used magazine paper: look you can see where the ink has lifted off the page.
3) The final print, I'm not going to remove the toner until I'm ready to solder.

I took the above pictures by scanning the board/paper - much better than messing around with a camera.

Hero999 said:

Here's my latest board etched using magazine paper.

I didn't bother experimenting with a release agent because I want the board done tomorrow and don't want to experiment but get a reliable result.

Here are some pictures.

1) The toner transferred to the PCB: notice how the clay has stuck to the toner giving it a greyish colour.
2) The used magazine paper: look you can see where the ink has lifted off the page.
3) The final print, I'm not going to remove the toner until I'm ready to solder.

I took the above pictures by scanning the board/paper - much better than messing around with a camera.

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really Nice result Hero. Scanning is the best. we resort to camera for want of scanner.

Don't you feel the drill holes of most components are larger. perhaps, for future boards, you may reduce the drill diameter so that each pad can have more copper skin, and the central drill marking can be as small , only to guide the drill bit centering.

What size are the traces

as well as component pads.
they look big??
mag paper looks like a good alternative but still wonder about jamming the printer, how small of a trace is possible etc.
As for drilling I do it after all the etching is done unless it double sided then I just drill 3 holes to register off of.
Going to try a 2x board using the transfer sheet folded in half process.
I worry about smearing the toner if transferring pattern separate times.
that's why I etch one side then do a transfer for second side.
takes more time and is a hassle.
are you going to coat the boards w/ liquid tin.
I found IMHO that the board will solder easier w/ coating.

I leave the toner and foil in place after the first etch. It does not smear. It may expand a bit, I have not checked it. If it does it is not a problem because it is already etched.

On a PCB where the one side is mostly jumpers, wider traces would not be a problem.

3v0

Hero999 said:

Here's my latest board etched using magazine paper.
{snip}
3) The final print, I'm not going to remove the toner until I'm ready to solder.

I took the above pictures by scanning the board/paper - much better than messing around with a camera.

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Nice looking board. However when I started out making DIY PCB, I remember not removing the toner first and ended up with with melted toner on the drill bit and messed up pad(s).

Copy paper for toner transfer..........

3v0 said:

Great work Rolf.

Is there any chance of making the glue work on something that passes light. Might make alignment easier for DS boards.

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Went back and checked some commercial wax paper, forget it!
Copy paper might help, it has no confusing print.
and with a strong back light, the alignment should be easy. (don't know for sure have not tried it)

Why not use copy paper?
Copy paper for DIY toner transfer?????????
How in the world is that done? (Remember you read it here first)
Just put two (2) coats of glue on it, like I described in a previous post.
---------------------------------------------------------

Takes to long!
Have not got the time, it takes about 5 minutes to make 6 sheets. (Not counting drying time.) I would rather be rubbing / scrubbing!
I don't like the paper to slid right off after soaking for a couple of minutes. Scrubbing is good exercises!

It is to fast, difficult, inexpensive, my wife wont let me us hers.
I like to jog while my laminator warms up for 30 minutes plus 20 minutes for good measure. And sending the board though from 2 to 6 times is no big deal!

No offense guys, most of the above is just parodies of past post.

You do have some valid points.

Tough to make a board in a few minutes if you forget to plug in the laminator ahead of time.

I think I will stick with the ready made paper. I have it, it works, and it is inexpensive

3v0

mvs sarma said:

Don't you feel the drill holes of most components are larger. perhaps, for future boards, you may reduce the drill diameter so that each pad can have more copper skin, and the central drill marking can be as small , only to guide the drill bit centering.

Click to expand...

That's a good idea, that way, you don't have to use a centre punch before drilling.

MrDEB said:

as well as component pads.
they look big??

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The smallest holes are 1mm - it's my smallest drill bit.

The smallest pads are 2mm wide.

I should have put a ruler in the picture, the board is approximately 35×78mm and is not perfectly square as I can't saw perfectly straight with a hacksaw.

mag paper looks like a good alternative but still wonder about jamming the printer,

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That'll only happen if you use really thin paper. I've never had a problem with jamming because the paper I use isn't much thinner than normal copier paper.

how small of a trace is possible etc.

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The traces on the boards above are all 0.5mm.

I've never needed to go thinner than 0.5mm but I know 0.25mm (about 0.01 inches) must be possible as I use it for the silk screen.

Yes I can do a silk screen using toner transfer with magazine paper, it's easy to do. Once I've etched and drilled the board, I apply the silk screen layer, using the normal toner transfer with magazine paper, then I cover it with a thin layer of conformal coating to seal it in.

Going to try a 2x board using the transfer sheet folded in half process.

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I haven't done a double sided PCB yet. If I do it that's the way I'd do it. Of course you'll need to take the thickness of the board and bend radius of the paper into account.

that's why I etch one side then do a transfer for second side.

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How do you etch just one side of the board?

Do you mask off the other side? If so how?

Rolf said:

Nice looking board. However when I started out making DIY PCB, I remember not removing the toner first and ended up with with melted toner on the drill bit and messed up pad(s).

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I've never had that problem.

Maybe it's because I've made holes in the pads?

Why is the mess a problem?

Can't you just clean the drill bits and the PCB?

Rolf said:

Why not use copy paper?

Click to expand...

I've never tried it but I imagine that it'll be hard to remove.

I would rather be rubbing / scrubbing!

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What scrubbing?

I don't need to do any scrubbing, the paper peels fairly cleanly off. There might be the odd bits and pieces that don't come off but I don't need to scrub. I was very lucking with the above board, the paper came completely off and didn't need soaking very long before it peeled.

Gonna do some adapter plugs for Junebug

Got the pc board designed, did a print, Glued a scrap piece of PULSAR paper to the printout (MISTAKE) using 3M #77 spray.
Did the lamination
worked great EXCEPT!!
I looked at the board and realized my traces are .25mm not .025 inches
BIG DIFFERENCE.
looked like spider webes but the traces did come out in the transfer.
going to redo tomorrow (no masking tape in shop)
have to go buy some.
the first print stuck to the second preventing the transfer paper from getting wet to remove.
lesson learned = double check trace size and do not use spray glue.
man those traces were small!!

1mm holes and 2mm pads = kinda big?

using express pcb the pads on an 18 pin dip are 1.42 round with a .74 hole
as far as drilling no problem.
use a #68 or #65 bit?? will find out which one tomorrow when I redo my transfer.
using a drill press is the only way (except maybe a CNC) but I etch first then drill..
makes for a pocket.

My adapter boards and LED candle PCB

After yesterdays diaster (wrong sized traces) I redid and here are the results.
EXCELLENT transfer using the PULSAR method and a laminator.
in the photo is the green TRF foil after applying to board.
the gree is removed from the foil onto the ink thus you end up with a reverse image of your board.
if you don't have a perfect image then the green didn't fully transfer.
the pads are 1.42mm w/ .74 holes traces are all .o25"
lets see a mag sheet duplicate.
I used an already used scrap of transfer paper (wish I had saved all the little scraps.) so this board is basically FREE!!!
going to be using 1 part muratic acid and 2 parts hydrogen peroxide as enchant.
after looking over PULSARS new site I see they are giving away free 5x6 copper boards. The price per page just dropped about 40% per sheet of transfer paper.
THANKS PULSAR. I need some more paper