Homebrew_PCBs

I made a really great looking toner transfer. When I etched it in a spray tank (standard chemicals not FeCl) several traces got slowly sprayed away. It seemed as if the traces might have been weekly bonded and the spray just washed them away over 1 or 2 minutes. Is this usual?
John

----- Original Message -----
From: Steve
To: Homebrew_PCBs@yahoogroups.com
Sent: Sunday, November 30, 2003 11:39 AM
Subject: [Homebrew_PCBs] Why I don't like the Photos folder


>From the moderator:

I do like the "Next/Prev" and the thumbnails. However, my big problem
with the Photos folder is that only the uploader and the moderator can
see the full size if you upload a larger file.

In other words, while I can see (and really like the closeups) those
500K and 1.1Meg huge JPG pictures, no one else but the person who
uploaded it can see that. Everyone else sees only a small version, I
think 300x400 pixels is the max.

So if you upload to Photos and you want people to see a closeup, crop
in to about 300x400.

If I knew how to make Yahoogroups warn you of this when you are
uploading a Photo, I would.

Steve, the moderator


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[Non-text portions of this message have been removed]

On Sun, 30 Nov 2003 12:01:06 -0500, John van Loon
<john@...> wrote:

> I made a really great looking toner transfer. When I etched it in a spray
> tank (standard chemicals not FeCl) several traces got slowly sprayed
> away. It seemed as if the traces might have been weekly bonded and the
> spray just washed them away over 1 or 2 minutes. Is this usual?
> John

i assume you have cleaned the board well?

maybe the mechanical force from spraying is too much for the toner.
what are the "standard chemicals" exactly?

did you use a iron or a laminator?
which printer model/ toner manufacturer did you use?

please crop your messages!
especially if you reply to another topic to get the right mail adress
delete the text of the other post.

st

> > I made a really great looking toner transfer. When I etched it in

a spray

> > tank (standard chemicals not FeCl) several traces got slowly

sprayed

> > away. It seemed as if the traces might have been weekly bonded

and the

> > spray just washed them away over 1 or 2 minutes. Is this usual?
> > John
>
>
> i assume you have cleaned the board well?
>
> maybe the mechanical force from spraying is too much for the toner.
> what are the "standard chemicals" exactly?
>
> did you use a iron or a laminator?
> which printer model/ toner manufacturer did you use?

Good questions; I'll add a few more:

Board cleaning is probably the biggest buggabo; sometimes you can get
good adjacent toner bonding and mask over a small fingerprint smudge
or some other contamination.

What temperature are your "standard chemicals" etching at? The
combination of heat and spray pressure might be too high for a weakly
bonded toner resist. (If the board is cleaned properly the TT bonds
are generally pretty good --also a bit of work getting off after
etching!)

How fine are the traces that are disappearing?

What oz. clad are you using? Although I haven't had much
undercutting using 1 oz - .5 oz and a FeCl agitated bath; even with 8-
10mil traces (if you are watching it closely!).

I haven't seen the need for this with the laminator, but some have
suggested "cooking" the newly formed resist layer for a bit in an
oven to allow the toner reflow and bond better to the board.

If you are using a laminator and cut the board down to size before
etching; did you clean/sand the scored edges? These can lead to
local eruptions along the cut edge and create just enough of a valley
on the board that the image will get uneven pressure through the
laminator.

I am using a Lexmark e210 printer, the enchants is hot.
I use an iron and a metal plate to heat the board. The metal plate (1/4
steel) is much flatter than the iron and alleviated many of the problems I
was having.
I think I cleaned the board well and I was careful in handling it only by
the edges. The edges were filed to remove any burrs.

I did it again tonight and got a good transfer. On further inspection I
found I could rub off some of he traces with moderate pressure using my
finger. They were all in roughly the same area of the board. Other areas did
not get removed. The tones seems to flake away from the copper when I
scratch it. Again the other areas have good adhesion.
Funny enough there are traces that are stuck well to the copper and right
beside them is a trace that is not, then another trace that is, all within
.2".

I think this is probably what I am seeing in the tank.

I think I will try the baking to reflow the traces as well as using the fine
setting on the printer.

Questions:
1. Should the whole board come out with really god adhesion?
2. Any ideas? Is this a pressure issue (I left the iron and steel plate with
no pressure)? Temp issue (the paper turned brown after being under the iron
for a short time, the copper oxidized where it was not under the paper)?
Time (8 min)?

Thanks for the help I am definitely farther than I have ever been.
John

----- Original Message -----
From: "Stefan Trethan" <stefan_trethan@...>
To: <homebrew_pcbs@yahoogroups.com>
Sent: Sunday, November 30, 2003 12:08 PM
Subject: Re: [Homebrew_PCBs] spray Etching of TT


> On Sun, 30 Nov 2003 12:01:06 -0500, John van Loon
> <john@...> wrote:
>
> > I made a really great looking toner transfer. When I etched it in a
spray
> > tank (standard chemicals not FeCl) several traces got slowly sprayed
> > away. It seemed as if the traces might have been weekly bonded and the
> > spray just washed them away over 1 or 2 minutes. Is this usual?
> > John
>
>
> i assume you have cleaned the board well?
>
> maybe the mechanical force from spraying is too much for the toner.
> what are the "standard chemicals" exactly?
>
> did you use a iron or a laminator?
> which printer model/ toner manufacturer did you use?
>
> please crop your messages!
> especially if you reply to another topic to get the right mail adress
> delete the text of the other post.
>
> st
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>

--- In Homebrew_PCBs@yahoogroups.com, "John van Loon" > I did it
again tonight and got a good transfer. On further inspection I

> found I could rub off some of he traces with moderate pressure

using my

> finger. They were all in roughly the same area of the board. Other

areas did

> not get removed. The tones seems to flake away from the copper when

I

> scratch it. Again the other areas have good adhesion.

It may be possible that you are overheating the toner. I've noticed
that it gets less plastic the more you heat it until eventually it
starts to flake.

I haven't tried a lexmark printer/toner for TT; is it a factory
cartridge?

> Questions:
> 1. Should the whole board come out with really god adhesion?

yes. only sometimes on the edges i had a bad spot (i have a board outline
trace most time which likes to get off where i start peeling the paper)

> 2. Any ideas? Is this a pressure issue (I left the iron and steel plate
> with
> no pressure)?

I apply pressure, no idea, maybe 30N or so.. no more than 60N.

> Temp issue (the paper turned brown after being under the iron
> for a short time, the copper oxidized where it was not under the paper)?

My paper gets slightly brown (more yellow) after the whole run. the copper
discolors very slightly too.

> Time (8 min)?
>

30 second to 1 minute.
may be too long your 8 minutes.
you can cut down time if you preheat the board but i don't really see a
reason.

> Thanks for the help I am definitely farther than I have ever been.
> John
>

not sure if you steel plate is perfect, i don't really get the picture, do
you attach the steel plate to the iron and press with it or what?


st

In my last post, I mean't to say:

> > Why never add water to acid?

You will end up wearing the acid. Further, when
pouring /measuring/ dispensing any chemical (Acid or
not...), DO NOT DO IT at eye level and always wear eye
protection and protective clothing.

Best regards


Marvin Dickens
Alpharetta, Georgia USA


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