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Thread

Not happy with my etching.

2014-01-09 by <tom42107@...>

I'm not happy with my etching. I'm using FR4, 1oz. copper boards. My copper cleaning is very thorough and my toner transfer is very dark and even. My etchant solution is two shot glasses of muratic acid and four shot glasses of hydrogen peroxide, ( I just use a shot glass glass to get even increments ). I put the board in the etchant and agitate for four to five minutes, or until all the copper is gone. It works pretty good but my copper is coming out dull an a little pitted, not nice and shiny and pretty like some of the the toner-transfer boards I've seen here. Not sure what I'm doing wrong. Should I use less hydrogen peroxide? I've etched a lot of boards and some of them turn out good but I think they can be better. Thanks.

Tom

Re: [Homebrew_PCBs] Not happy with my etching.

2014-01-10 by Geoff Wood

----- Original Message -----
From: tom42107@...

>I'm not happy with my etching. I'm using FR4, 1oz. copper boards.

>My copper cleaning is very thorough and my toner transfer is very dark and even.

>My etchant solution is two shot glasses of muratic acid and four shot

>glasses of hydrogen peroxide,

If your copper is pitted, then your resist is not working.

Maybe ferric chloride or ammonium persulphate would be gentler on the toner/resist.

geoff

Re: [Homebrew_PCBs] Not happy with my etching.

2014-01-10 by James

Sounds like a toner density problem to me. Using less peroxide will slow the etch down, but if it's taking 5 minutes, I think that's slow enough already.

Tried UV exposure methods?

On 10/01/14 12:49, tom42107@... wrote:

I'm not happy with my etching.

RE: Not happy with my etching.

2014-01-14 by <newaag@...>

After cleaning the board with lacquer thinner post etch, use a fine paste metal polish to shine it.

I use mothers mag wheel polish. It makes it very shiny. Then clean with dish detergent.

I sometimes may also hit the traces with silver solder to beef them up.

If you are making more than 5 boards the same, it may be worth it have them done in China. I have mine done there for about $100. (150 square inches total) delivered, takes about 2 weeks. That's for double sided with silk screen one side, same design. I won't give the name, or people will think I work for them. I don't, just happy with their work.

Bob

Re: Not happy with my etching.

2014-01-14 by Dave Sage

Skip the metal polish stage.

Shiny is NOT what you're looking for. If anything you should be sanding it with perhaps 600 grit wet/dry paper.

In addition, who knows what the metal polish leaves behind. Usually a layer of wax which is part of the product.

The ONLY things I do is use medium steel wool to clean the copper oxide off the surface and then scrub with a household cleaning product called "Spray Nine" by Knights. Rinse with water and let dry.

(Apparently similar to "Fantastic" spray cleaner - can't vouch for that).

It's slightly caustic (symbol on bottle) and is a very good degreaser.

That's all I do and have NEVER had problems with the toner of my vintage HP LaserJet III sticking.

Your laquer thinners should be enough as well following the steel wool.

Wear rubber gloves so you don't touch the board after cleaning.

Sage

Re: Not happy with my etching.

2014-01-14 by <newaag@...>

Shiny is not the desired end product.

It's simply the result of using very fine particles in a paste to abrade the surface and clean it. You can also use fine wet automotive sandpaper, compounding paste, whatever. It's the same thing.
After cleaning the copper to remove the oxide, it's a lot easier to solder.
I think most people don't recommend steel wool to clean copper, but maybe that's before the toner goes on, not after. I hate the stuff, never use it anywhere. I use green scotchbrite pads and water instead.

I've made over 3 dozen toner boards this way, and it works great for me. I use a laminator to apply the heat, and Pulsar products, including the green film over the toner before etching. Also, post etch use toner and the Pulsar green film to apply the text / top parts designation ("silk screen") which makes it a lot easier loading parts.

Bob

Re: [Homebrew_PCBs] Re: Not happy with my etching.

2014-01-14 by K M Zahidur Rahman Samrat

you have problem with your tonner and printer regulation is not that much high enough that was in need

On Tue, Jan 14, 2014 at 7:52 PM, <newaag@...> wrote:

Shiny is not the desired end product.

It's simply the result of using very fine particles in a paste to abrade the surface and clean it. You can also use fine wet automotive sandpaper, compounding paste, whatever. It's the same thing.
After cleaning the copper to remove the oxide, it's a lot easier to solder.
I think most people don't recommend steel wool to clean copper, but maybe that's before the toner goes on, not after. I hate the stuff, never use it anywhere. I use green scotchbrite pads and water instead.

I've made over 3 dozen toner boards this way, and it works great for me. I use a laminator to apply the heat, and Pulsar products, including the green film over the toner before etching. Also, post etch use toner and the Pulsar green film to apply the text / top parts designation ("silk screen") which makes it a lot easier loading parts.

Bob

RE: Not happy with my etching.

2014-01-14 by <tom42107@...>

Thanks for the answers. I guess I didn't explain very well. I'm not really looking for nice shiny traces. I feel like I might be over etching. My traces are pitted and thin in areas, like I'm leaving the board in the etchant to long. I was wondering if I need to tweak my etchant a little. I may try to move up to a laminator soon. Thanks.

Tom

Re: [Homebrew_PCBs] RE: Not happy with my etching.

2014-01-15 by Harvey White

On 14 Jan 2014 12:58:32 -0800, you wrote:

>Thanks for the answers. I guess I didn't explain very well. I'm not really looking for nice shiny traces. I feel like I might be over etching. My traces are pitted and thin in areas, like I'm leaving the board in the etchant to long. I was wondering if I need to tweak my etchant a little. I may try to move up to a laminator soon. Thanks.

If your fine traces are way too thin, then you're overetching. If the
traces are pitted, especially in ground pour areas, and the traces are
ragged as well, then it's most likely that you are the victim of thin
resist with holes in it.

Harvey

>
>Tom

RE: Not happy with my etching.

2014-01-18 by <tom42107@...>

Well, I think I fixed my etching problems. I tried two different things. One, I used a laser printer instead of a copier machine to print the layout and two, I used a paper towel during the etching process to gently wipe the copper while it was etching. My board came out really nice, nicest one so far.

Tom

RE: Not happy with my etching.

2014-01-18 by <newaag@...>

Thanks for the update. In many cases, the manual "dark/light" controls on big copiers may have more dark range and is easier to use than the ones on laser printers (especially old ones). At 5 cents a copy at the UPS store, it may be a better option for many.

I also use the "wipe" method. I use a small cotton rag cut from old t shirts on the end of a wooden stick, fixed with a rubber band. By wiping during the etch, it appears to greatly accelerate the etch time.

The last thing you can try is ironing the green Pulsar TRF (Toner Reactive Foil) coating over the toner traces before etching. This film is available from Mouser, with no minimum order.

http://www.mouser.com/ProductDetail/Pulsar/GREENTRF-50-1225/?qs=sGAEpiMZZMuBqtBq7f3lE5J41PywjpQhP1d50npXonI%3d

other Pulsar supplies from Mouser

http://www.mouser.com/catalogviewer/default.aspx?page=2333&highlight=5165-GTRF&catalogculture=en-US&catalog=646

I like their supplies, for me, well worth the $. I also use their paper for toner transfer.

Bob

---In Homebrew_PCBs@yahoogroups.com, <tom42107@...> wrote:

Well, I think I fixed my etching problems. I tried two different things. One, I used a laser printer instead of a copier machine to print the layout and two, I used a paper towel during the etching process to gently wipe the copper while it was etching. My board came out really nice, nicest one so far.

Tom