My First PCB Etch...............

[Stu Diddly]

Hey Everyone, I just etched my first PCB and it didn't turn out so well.  Does anyone have any award winning techniques for how to effectively transfer toner from PNP?  These pics are pretty bad.  I tried etching Gus's NPN Boost.

[s.r.v.]

iron more than you think you have to.

[tranceracer]

What etch technique did you use?

-tR

[Plinky]

Clean the copper board really good with lighter fluid and a tissue to get all the dirt and oil off of it.
You'll know you're ready when you hardly see any gunk on the tissue. Heat the board up a bit prior to placing the PNP (MAKE SURE LIGHTER FLUID HAS DRIED BEFORE IRONING!!!).
Just a minute should do. When you iron the PNP use firm pressure. At first hold the iron still, then move around the
board to get all the corners and such. You should see a fairly clear image of the traces through the PNP when it's ready.
Like SRV said, iron for longer than you think is necessary. My rule of thumb is when you think you're done, iron for about 5 minutes more.
If you need anymore help, Tonepad.com has a great photo essay of the whole process.

http://www.tonepad.com/photoessay.asp?photoEssayID=10&sequenceNo=1

[cloudscapes]

coincidentally, I was JUST doing my first etc and transfer tonight. I'm warming up the ferric chloride in the sink in preperation this very moment!

my board is 2" x 3", so a bit bigger than most people's first etches. as others have said, I needed to iron quite a bit longer than expected, on "wool" mode. once it was done, I went at it with fine action marker to beef up the thinner lines, or the ones that didn't transfer flawlessly. it helps when you shine a light into it and see if any specs inside anyof the traces are reflecting, indicating a dust-sized hole to fill.

[RedHouse]

iron more than you think you have to.

I dunno, the way the pads are distorted it looks to me like overheating. When the transfer is overheated it "melts" and makes blobs and oblong pads like that.

Did you pre-heat the board? (sometimes too much pre-heating can cause the melting pads thing)

Actually the more I look, it appears to be a bad iron-on transfer that has had extensive "sharpie" work done just before etching.

[Stu Diddly]

Hey Everyone, thanks for all of your help and replies.  I did not pre-heat the board beforehand.

[/quote]
Actually the more I look, it appears to be a bad iron-on transfer that has had extensive "sharpie" work done just before etching.
[/quote]

You are right, I did sharpie the crap out of the board before I etched it. I'll never do that again.  I'm getting ready to take a shot at this again.  I'll try the methods that you guys suggested and I'll post pics of my next etch.

Thanks

[96ecss]

You may have already seen this, but this is the method I use and I get great results. http://www.smallbearelec.com/HowTos/DirectPCBoards/DirectPCBoards.htm

Dave

[BubbaKahuna]

I've found model paint (Testors) or similar to be far superior to Sharpies for touchups.
Cleans up the same, but stays exactly where it's put as long as you need it there.

Other things I've tried that make better transfers (not all at once - lol):
1. Clean, then etch the board BEFORE you transfer for only about 15 seconds. Wash well and clean again with rubbing alcohol. Toner sticks like nobody's business.
2. Use Barkeeper's Friend brass cleaner to scour the board before etching. Cleans really well.
3. Use some of that silver cleaner that you just dip stuff into. Man, does that stuff make copper CLEAN!

In any case, make sure you don't get oil from your skin/fingers on your board after cleaning it. Toner will never stick right to it until you clean it again. Same goes for the paper with the toner on it. If it has finger oil on it, it's no good. Print it again.

Like others have said, iron the crap out of it. You should clearly see your image right through the paper. Corners are notorious for not taking well so get them really well.

Don't be afraid to push down on the iron. If your board is on a table or other solid surface, you won't break it.

Too hot means burning the paper dark. Anything less that that is not too hot.

Preheat your board until it's pretty much too hot to handle with bare hands.

Do your ironing and preheating directly on a thick piece of cardboard. You won't start it on fire and it will prevent the heat from being wasted into your counter or table top. Anything that's not helping insulate the bottom of your board during heating (like cardboard) will work as a heat sink taking heat away from your board and preventing it from getting really screaming hot from your iron. Cold, thick counter tops are the worst surface to iron on with copper clad - you might as well do it on concrete or a big block of steel.

Cheers!

[railhead]

I've never had any luck with PnP, so I still use transparency paper.

For me, the key has been to get the board really clean so that it accepts the toner -- and I achieve that by using steel wool until the whole copper board is nice and evenly shiny. About 2 minutes under the iron, and I'm done.

[cloudscapes]

using steel wool until the whole copper board is nice and evenly shiny

that's what I did. steel wool with Comet cleanser. I also used steel wool to get the toner and ink off the board when it was all etched. took a minute. I used the smallbear guide.

http://nearworlds.org/stuff/diy/first_pcb_etc.jpg

[Stu Diddly]

I've never had any luck with PnP, so I still use transparency paper.

Transparency Paper?  Where do you get that?  I've only heard of people using photo paper from Staples.  PNP has been horrible for me.  I tried 3 transfers last night and none of them turned out well. I'm up for trying anything now.

[railhead]

It looks like a lot of you are applying heat for too long, thus causing the bleed and blob. Here are some shots of how my PCBs consistently turn out:



Transparency paper is just the clear "paper" you use when you're using and overhead projector -- you can get it anywhere. Print (with a laser printer) onto the sheet, cut it out (leaving extra on the sides so you can tape it in place), fit it over the PCB, and slip a thin handkerchief or something between the film and the iron. Done deal.

As for PCB prep, after I cut it to size, I use 800 grit sandpaper to give an initial rough-up, then follow that with final finish steel wool until the ENTIRE surface is nice and shiny. Rinse with water, dry on a paper towel, and iron the sucker.

[5thumbs]

I've never had any luck with PnP, so I still use transparency paper.

Transparency Paper?  Where do you get that?  I've only heard of people using photo paper from Staples.  PNP has been horrible for me.  I tried 3 transfers last night and none of them turned out well. I'm up for trying anything now.

I had horrible results with PnP Blue and my Brother laser printer at the start.  Brother laser toner has a higher fusing temperature than many laser toners, so it's harder to get it to melt onto the copper-clad board.  I usually ended up turning up the iron very high to get most of the toner to transfer, which caused the transfer image to distort.

Once I discovered this issue with Brother toner, I stopped printing my PnP Blue pages through my printer.  I print out my transfer patterns onto standard paper and then transfer it to PnP Blue using a commercial-sized copier.  (In my case, a large office Xerox copier.)  The copier toner works MUCH better than the Brother toner.  It melts evenly at my iron's 'polyester' setting, which is described by many as the minimum heat at which PnP Blue generally works well.  I get very clean and complete transfers now with very little clean up required before etching.

A couple tips for feeding PnP Blue sheets through a copier: 1) use the bypass sheet feeder rather than feeding from the paper trays; and 2) on the shiny side of the PnP Blue, spray a very light mist of spray adhesive and carefully align/affix a sheet of standard paper to the newly-sticky side of the PnP Blue sheet.  I've found these two steps help prevent the PnP Blue sheet from slipping on the copier feed rollers, which will cause your PnP sheet to wrinkle and/or get eaten altogether when copying.  When you're ready to transfer, carefully remove the paper backing and gently clean the shiny side of the PnP Blue with a clean rag with a small amount of naptha (lighter fluid) on it.  This will keep the light mist of adhesive from gumming up the bottom of your iron.

Of course, all of the copper-clad board cleaning steps before ironing the PnP Blue mentioned above are still necessary, so make sure to continue doing those prior to attempting PnP Blue transfer.

[niggez]

I etched my first pcb a few days ago, it is an mk-2 tonebender.
I used an edding pen to "write" the layout on the copper, found this to be very, very simple - and cheap! No problems whatsoever.

[Mark Hammer]

One of the things people tend to forget is that the etchant doesn't "know" to eat away the copper in one direction - vertically.  It simply goes where the copper is.  So, while the pattern you have transfered or drawn may look like it covers the copper, once the etchant has eaten down to the board, there is this nice little band of exposed copper at the side of every single pad and trace, and it just keeps chomping and chomping if allowed to.  If you find that most of the traces have been rendered clear, but there is this one problematic "web" of dull-looking copper between several pads, AND you leave the board in the etchant longer, do not be surprised at all to see that the sides of the traces have started to be eaten away, much like what Stu Diddly shows in his board.

The secret to a good etch is to engineer things for a fast etch.

1) If the etchant can't be 100% fresh, then there should at least be good separation between the still fresh stuff at the top, and the used stuff sitting on the bottom.  A tall thin container is better in this regard than a shallow wide one.

2) The surface of the board can not have any "finger juice" on it, or any other impediments to the etchant reaching the copper easily.  So even if you do use lighter fluid, or achohol, or superfine steel wool, or whatever, anywhere that you touch the board's gleaming surface with your fingers is at risk.  Use gloves or paper or whatever you can to make sure that neither finger secretions, nor spittle from that youtube thing that had you cracking up 5 minutes ago, nor breath, nor ANY sort of residue lands on the copper.

3) Warmer etchant works faster than cold etchant.  If you can't warm the etchant bath, you can at least warm the board or etchant bath surface with a heat lamp, or hair dryer, or reading lamp.

[5thumbs]

Just to update on the Brother laser toner situation...I finally threw out that lousy Brother-brand toner and got an Office Depot re-manufactured toner cartridge.  The Office Depot cartridge worked extremely well with PnP Blue.

So if you have a Brother laser printer and want to use PnP Blue, avoid Brother-brand toner like the plague and get re-manufactured toner cartridges.

[unidive]

that board is still salvagable though, just blob some solder on the broken trace and join the two halves