Does anyone etch anymore?

[percyhornickel]

I have tried a few times with no luck!!

What went wrong ?

Don´t know, borders of the tonner/papper lifted over the pcb even with low voltage I remember.

[Mark Hammer]

I've done some home-etched PCBs that had me questioning my sanity, for sure. Sometimes I feel that I hadn't quite recovered. Though, there was something quite therapeutic about it. After getting familiar with a few big PCB manufacturers I'd say I'd probably never etch a board again. My current situation of finance and patience outreach the tribulations of etching and toner transfers by miles.

For years I did magazine paper or glossy photo paper toner transfers and etched in 50/50 muriatic acid & hydrogen peroxide.
I also did a thread about home made tinning solution that's deep in the forum somewhere. Wouldn't mind revisiting that one eventually. Mostly to replate edge-card connectors.

Oh yeah, I have some of my old transfer files in my signature. For the overly ambitious.

It was fun until it wasn't 

Forty years ago, my etching technique was as follows:
1) Photocopy the layout in the magazine article and tape it to a piece of copper-clad board.
2) Go over it with my spring-loaded centre punch and pop a dimple in the middle of every pad.
3) Remove the photocopy and use a water-resistant fine marker to draw the pads on, or possibly use rub-on transfers to place nicely circular pads on.
4) Play connect the dots with the marker pens.  One technique I adopted was to have 2 colours in addition to black.  I'd draw the traces connecting the dots in one colour (e.g., green), then go over those traces in another colour (usually red), and finally over them again in black.  Using the different colour marker pens allowed me to know which ones I had gone over and reinforced, and which ones I hadn't.  Preferred pin was the Staedtler Lumocolor.

I probably didn't keep my damn "finger-juice" off the boards then as much as I have learned to do since.  I also discovered carbide drill bits.  Forty years back I had only conventional drill bits.  Fortunately, grad school offered me access to decent workshops whose drill presses had much better chucks than I have now.  The resulting boards weren't pretty, but they worked OK.

I'm still waiting for the folks who came up with toner transfer to receive their Nobel prize.

[Dormammu]

Don´t know, borders of the tonner/papper lifted over the pcb even with low voltage I remember.

It is more important not to exceed the current so as not to overheat the solution.
And tracks drawn in the old school style are less prone to flaking.

[tonyharker]

Im sure everybody can get peroxide and vinegar.  Mix equal parts and add a small amount of salt and away you go!

[percyhornickel]

Im sure everybody can get peroxide and vinegar.  Mix equal parts and add a small amount of salt and away you go!
[/quote

Maybe the venezuelan vinegar is mixed with too much water      ...I tried this way to with luck, Maybe I could try Electrochemical once again sometime.

I liked the Mark`s old school technique, I just take a photocopy on normal paper (with high quality to get more tonner in the tracks) and put on the pcb with tape, carefully heating and pray like 3 hours hoping the tracks don`t lift. 

This way worked fine most of the times.

[Mark Hammer]

"Normal" paper (that is, NOT shiny) will not work very well, or at all, as a toner-transfer method.  The toner has to want to stick to the copper MORE than the shiny coating on the paper wants to stick to the paper.  If there is no shiny surface to the paper/sheet, then the toner will "like" where it is, and not want to come off.

[percyhornickel]

"Normal" paper (that is, NOT shiny) will not work very well, or at all, as a toner-transfer method.  The toner has to want to stick to the copper MORE than the shiny coating on the paper wants to stick to the paper.  If there is no shiny surface to the paper/sheet, then the toner will "like" where it is, and not want to come off.

Ok Mark, next time I will try with another kind of paper for sure  (magazine or glossy paper), I always clean my pcb surfaces with sand paper and alcohol before putting any paper on it.

I made most of my projects with this method: 3207 mod zombie chorus, some rats, pulsar, TS, Dist +, DB Delay, Rebote Delay, DOD compressor, Orange Squeezer, OD-1, FF Ge, FF Si, Tone Bender, Big Muff, LP JTM, Purple Plexi, Plexi Drive, OCD, etc...

All of them always had little tracks problems, it is time to find a best way for transer..

PH

[amptramp]

I'm waiting for someone to do a board with a 3-D printer.  Either print the conductors or print the resist on a copper-clad board.  No need for the third dimension, so it should print pretty rapidly, like a minute per square inch.  Certainly not a production technique but for a one-off, this could be good.

[Mark Hammer]

Ok Mark, next time I will try with another kind of paper for sure  (magazine or glossy paper), I always clean my pcb surfaces with sand paper and alcohol before putting any paper on it.

I made most of my projects with this method: 3207 mod zombie chorus, some rats, pulsar, TS, Dist +, DB Delay, Rebote Delay, DOD compressor, Orange Squeezer, OD-1, FF Ge, FF Si, Tone Bender, Big Muff, LP JTM, Purple Plexi, Plexi Drive, OCD, etc...

All of them always had little tracks problems, it is time to find a best way for transer..

PH

Although Press-and-Peel blue works best, it is expensive.  In recent years, I have switched to some yellow sheets I have bought from several sources, at about 1/5 the price, if not less.  They are A4 size, unlike the 8.5 x 11" that PnP blue comes in, so one has to be mindful of lining it up right.  But it works very well, and has 95% of the precision that PnP does.

I rate transfer paper based on the spacing required.  For a 2 transistor fuzz with space between pads, photo paper - even the cheapest kind -is sufficient.  Glossy magazine paper is also probably okay, but whatever is printed on it may make it hard to tell if the toner pattern has been completely transfered.  If there are ICs with 1 or 2 traces running between the two rows of IC pins, then I use the yellow sheets.  If there are ANY pads for surface-mount components, nothing less than PnP will do.

[percyhornickel]

Ok I found here in Venezuela the yellow pcb transfer sheets here (kind of expensive too / $3 each), I think I will ask to my sister if there´s a chance to send me a few ones from U.S.A. next time she sends a box with "supplys" (she does it 2 or three times at year) so I´ve could try this method, for the kind of circuits I build this is more than enough I guess.

I was thinking to build something like the Ibanez CP-9 compressor (tonepad´s layout) which has traces running between the IC pins, I hope it gets easyer this way than the normal or glossy papper way.


PH

[deadastronaut]

nope, not boards, i despised the drilling and dust ,  i only etch my enclosures now....

if i desperately need something quick i use stripboard still..but even that's rare these days..

[percyhornickel]

nope, not boards, i despised the drilling and dust ,  i only etch my enclosures now....

if i desperately need something quick i use stripboard still..but even that's rare these days..

I have seen your etched enclosures in your site before, a really nice work!

[Phend]

Long time ago when I was a kid.
Etched one that needed no batteries.


-

[mark2]

Only if I want to quickly try a circuit for which a layout already exists, or for situations where a special footprint is needed (e.g. impromptu adapter boards).

I recently tried spray painting the PCB black, then using a laser to remove it and it worked flawlessly. Far better than my old toner transfer methods.

[Phend]

Were any "thin lines of copper" left behind because of the resolution of the raster used to remove material.?

[mark2]

Were any "thin lines of copper" left behind because of the resolution of the raster used to remove material.?

At 300 lines per inch (LPI) it worked great, and it completely obliterated the paint.

I spray painted a few boards and tried out different speeds and power settings to find the optimum, but I don't recall if I experimented with LPI values and 300 was the best, or if I simply didn't try others.

[Phend]

How many watts ?

[mark2]

It's a 50W CO2 (@ 20%, 60mm/s). I just saw in my notes I ran it a bit out of focus, too, which probably contributes to avoiding any thin lines.

That said, I bet any laser, even a weak diode, can get through paint with enough patience.

[Phend]

I can etch thru the paint, not sure about the copper.
Found this stuff, not sure what it is, or where I got it. (ca7fr)
My laser is 40w and cuts 10mm acrylic in one pass.

[mark2]

Reading back to my earlier post

I can etch thru the paint, not sure about the copper.
Found this stuff, not sure what it is, or where I got it. (ca7fr)
My laser is 40w and cuts 10mm acrylic in one pass.

Checking back on my earlier post, I think I may not have been clear.  The paint is just an etching resist. I still use HCL and hydrogen peroxide to etch the board.

Copper is way too reflective for a CO2 beam to remove it.