PCB Etching Pen

[mitzrecords]

sorry if this was posted before. I searched but no luck.

I want to try etch my pcb board. but i want to use simply pen.

What kind of pen do I need for this?

any special ecthing ink pen??? or shrpie ok?

thank you!!!

[John Lyons]

What kind of etchant will you be using?


John

[sean k]

I use sharpies for the ammonium persulphate but I've also used in with the ferric... on Aluminium! The PCB pens have a very soft felt tip whereas the sharpies have a very dense felt tip that lasts as long as the ink does.

And you can use a pen knife to tidy up your traces by scratching sharpie ink off the copper. I do the bases for IC by blocking in sharpie the scratching in the lines between pins and power traces. I use an .9 mechanical pencil with a 2b lead to draw onto the copper and thats the only problem I have slight problems with because the graphite left on the board has to be etched away before the etchant starts in on the copper underneath is but, in saying that I might get the penknife out and do some scratching to tidy that up. This is my latest board ready for etching.

[Ice-9]

A sharpie is great, also cd/ dvd marker pens workwith ferric

[BINGEWOOD]

I bought a Sharpie "INDUSTRIAL" pen at my local elec. surplus place.  I use it to clean up traces on boards I've transfered to.  The ink seems a little better than regular Sharpie which I usually have to do a couple coats of to be sure it won't burn through during etching.

[bumblebee]

I use a dykem printed circuit marker with ferric chloride, but thats only because when I bought a couple of them I didn't know sharpies work, sharpies are cheaper so I'll buy them in the future. I always hand draw the traces on basic circuits,I'd print it with more advanced PCB's though.

[oldrocker]

I use a sharpie and it works good for me using ferric.

[rnfr]

i've had problems w/sharpies and muriatic acid/peroxide. seems to take it right off.  anyone else have this problem?

[mitzrecords]

cool!

i have ferric C so im gonna go buy sharpies.

thanx everyone!

[culturejam]

i've had problems w/sharpies and muriatic acid/peroxide. seems to take it right off.  anyone else have this problem?

I use muriatic to etch, and I do trace cleanup with a Sharpie. No problems so far.

[solderman]

Hi
I etch all my boards my self. I would suggest  the method where you use a transparent film with the schematic pattern printed from a laser printer (or you can also paint it with  any type of filtpen that leaves a nontransparent trace) and then put it over a cupper laminate with fotoresist on it. Then you expose it with UV light for about 8-12 minutes depending on your light source. After that you develop (with sodiumhydroxide) it and then etch it. With this method you can get professional result and really high resolution traces an grate result. And its quite easy to. All you need is a UV light, a transparent film, developer and etch.

Very much like taking a picture and develop it.

//Solderman.

[davent]

Hi
I etch all my boards my self. I would suggest  the method where you use a transparent film with the schematic pattern printed from a laser printer (or you can also paint it with  any type of filtpen that leaves a nontransparent trace) and then put it over a cupper laminate with fotoresist on it. Then you expose it with UV light for about 8-12 minutes depending on your light source. After that you develop (with sodiumhydroxide) it and then etch it. With this method you can get professional result and really high resolution traces an grate result. And its quite easy to. All you need is a UV light, a transparent film, developer and etch.

Very much like taking a picture and develop it.

//Solderman.

Hello,

I've always used standard flourescent tubes as my light source for exposing boards. I give the boards 12 minutes with them an inch or two (25-50mm) away from the tube. You're absolutely right in that this method gives the best results by far, i'm baffled* as to why more people don't use this method. From printing out the transparency to having an etched board in hand can easily be done in half an hour and that includes the 12 minute exposure.

I've been messing with Toner Transfer methods using both commercial products and magazine transfers to use up untreated boards i have around and it usually takes at least half an hour to fix up the lost bits in the toner transfer -> board. And to that end I've had no problems with Sharpies in both ferric chloride and muriatic acid/hydrogen peroxide etchants. I've also used nail polish and model paint with ferric chloride.

Take care,
dave
*edit. Well not totally baffled as the colour of all the pretreated boards i've used i do find repulsive, a truly ugly yellow/brown. Ugly enough to keep me searching for new brands.

[John Lyons]

i've had problems w/sharpies and muriatic acid/peroxide. seems to take it right off.  anyone else have this problem?

Sometimes I will use a sharpie to trace over areas of the board but most of the time I use model enamel paint and a toothpick to touch up boards with flaked off toner, then scrape with a razor knife to make that look pretty. Lumocolor permanent pens work ok as well (thanks mark H)
I use HCL/H202 and sharpie will get eaten though sometimes..depends on the etching time and copper thickness.

[rnfr]

i've had problems w/sharpiit and muriatic acid/peroxide. seems to take it right off.  anyone else have this problem?

Sometimes I will use a sharpie to trace over areas of the board but most of the time I use model enamel paint and a toothpick to touch up boards with flaked off toner, then scrape with a razor knife to make that look pretty. Lumocolor permanent pens work ok as well (thanks mark H)
I use HCL/H202 and sharpie will get eaten though sometimes..depends on the etching time and copper thickness.

same results here.  it seems a bit strong for sharpies.  maybe nail polish might work?  lumocolor?  are these paint pens?

[solderman]

Yes
Its the UV fotoresist method that is both simple and gives the best quality as I see It. The thing I have the most problem with I drilling the holes. I just hate this part. I use a table model of a drill stand with a standard electric drill and a special 0.8 mm drillbit with a hardmetal tip (industrial diamond) It's the only drillbit that stays sharp for longer than 25 holes. But the thing is so fragile that it brakes so easily and it costs 4$ each where I bye it. I love to etch and build but I really hate the drilling part. If there is someone out there that can invent an etching methods for holes, besides letting somebody else do it, that would be the heaven and worth a Nobel prize as far as I am concerned.

[R.G.]

My DIY friends and I put a lot of effort into PCB making methods back in the 70's. We eventually came up with a method that was incredibly useful under some special conditions.

HP used to make a small flatbed plotter. It would plot anywhere on a letter-size sheet of paper, and had an HP-GL (i.e. "graphics language") interface and RS232 input. The plotter pens were like sharpie, but the ink was ordinary ink. You could - if you were desperate enough - take a mechanical drafting pen (these still existed then in the pre-personal-computer days) and adapt it to fit in the plotter-pen holder of the plotter. Drafting pens were fillable with any ink of your choice, and we chose to fill it with thinned lacquer. Fingernail polish would do. Now we could clean and dry a piece of PCB, pop it into the plotter and plot the resist on it. Working at A Major Computer maker, we had computers available which would do the drawing and the plotting for us.

It was a true PITA to keep the plotter pen cleaned up from drying lacquer, but it was the shortest path to quality PCBs.

On drilling. If you are serous about drilling, there are two tools you need. First is a jeweler's drill press.
(http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=81631)
It's $175 list, but it goes on sale periodically for $140 or so. This machine - I have one - is stable enough that it will not break solid carbide bits unless you move the PCB while drilling.

The other tool is the true icing on the cake - a drill microscope. Drilling is hard for two reasons. One is drill longevity and the other is accurately spotting holes. The jewelers drill press solves the longevity problem. A drill microscope is a microscope with a small magnification, maybe 3 to 8x, with crosshairs, which you look through at the etched PCB. You put the cross hairs on the center of the pad and push the leverl which raises the drill bit through the bottom of the PCB. This was how PCBs were all made before CNC.

You can make your own drill microscope from a cheap ($10) rifle telescope with some modification.

[tranceracer]

Here's another thread with some excellent responses.  Basically I now use Industrial Sharpie.

http://www.diystompboxes.com/smfforum/index.php?topic=66306.0

Mark Hammer recommended Staedtler Lumocolor pens.
Another suggestion was model pain enamel with a fine paint brush.

[R O Tiree]

I use photo-resist as well - very clean results.

For drilling, I use a small table-top milling machine with X/Y/Z controls. A little adjustment of the board in the clamps gets it absolutely straight, place the bit over the first hole and zero the controls. I've become such a nerd... I now know my 2.54 times table!

I like the idea of the drill microscope, though. Got some pics, please, R.G?

[R.G.]

I like the idea of the drill microscope, though. Got some pics, please, R.G?

Not any more. I posted this to usenet before there was a world wide web.

It's very simple though. You get your scope, usually a 7x20 in these parts, and fab an extension tube to get it to focus down to about 2" from the front lens. With that done,
you rig up any kind of firm supports to hold your drill bit and the microscope in alignment with a plate to lay the PCB over. I modified a Dremel drill press to make the drill come up from the bottom to about 0.1" max above the table. Then I mounted the scope on an arm over the drill and adjusted heights to get the drill point in focus just as it broke through an 0.062" thick board, and tightened the adjustments down.

Actually, today I would probably skip the rifle scope and get a USB microscope to attach to a PC. Then you could just watch the screen and move the board with your hands. Much easier than looking down through the scope at the drill.

As with most things electronical, the electronics part is incredibly simple. The mechanical fixturing and fitting is the PITA.

[rnfr]

so the drill is mounted under the table?  that does sound like a PITA!   

one trick that i have come to use is 2 light sources.  what you do is have one come in from overhead- say a lamp hanging down from the ceiling over your bench.  then you have a second lamp-  in my case a ultrabright reading lamp-  coming in from the side.  this way you can use the two shadows coming off of the drill bit as a kind of "crosshairs" to line up your bit with the solderpad.  once you get the hang of the angles it's a great way to sight things up.  give it a try!