Making PCBs with a pen - UK Vintage Radio Repair and Restoration Discussion Forum

Biggles · 13th Apr 2014, 9:22 pm

Hi all, can anyone recommend a decent make of etch resist pen for making PCBs using the old ferric chloride method? The permanent marker pens which I bought which were meant to be good enough for the job give very poor results, with tracks etched through where they should remain. I remember the Dalo pen which I used years ago successfully, and I was just wondering what types are best for the job. I don't normally use transfers because I have found that they left hairline cracks in tracks in the past.
Alan.

Bazz4CQJ · 14th Apr 2014, 2:51 am

I think you may have answered your own question Alan. Like you, I had good results with the Dalo years ago, but they seem to have disappeared and although some pens are being sold as "etch resistant", I haven't found anything which does the job.

Radio Wrangler · 14th Apr 2014, 6:45 am

Tiny brush and model enamel paint?

I've used car cellulose paint before.

David

Diabolical Artificer · 14th Apr 2014, 7:33 am

Tiny brush and bitumastic paint works. Used to use this method to make "Celtic" knotwork jewellery. Andy.

daviddeakin · 14th Apr 2014, 9:10 am

I've had sucess with all sorts of generic permenant pens, but only if you go over the lines two or three times, allowing it to dry in between, so you get a nice, thick, opaque deposit of ink.

Wendymott · 14th Apr 2014, 10:42 am

Hi Guys........ To be honest I found the only reliable way is to laser print onto clear acetate.. UV expose onto Photoresist material.......I am afraid the "Dalo" pen are long gone....If its a very simple pcb, then use a mini drill with a dentist burr and rout out the gaps.
Sorry I am forgetting you need to generate the artwork in the first place.... Maplin sell the PCB Wizard software......its very basic but ok for home use..
Regards
Wendy G8BZY

Radio Wrangler · 14th Apr 2014, 10:54 am

There used to be some X-Y computer controlled engraving tables that made proto PCBs

Probably too expensive, but I keep thinking of making one.... and a bigger one for a plasma torch!

DAvid

arjoll · 14th Apr 2014, 10:57 am

Something like this maybe? It's called a "Dalo Pen" in the Jaycar print catalogue.

(edit) showing as out of stock, but may be worth asking them anyway.

David G4EBT · 14th Apr 2014, 12:21 pm

Much closer to home, the pens are available from ESR Electronics at £1.25 each:

http://www.esr.co.uk/electronics/products/frame_pcb.htm

Lots of other PCB making stuff, (plus components etc).

I never had much success with those pens. For small one-off PCBs I find rub down transfers fine, using a soft pencil with a blunt point to rub them down. Having cleaned the bare PCB I dip it in etchant for a few moments and rinse it off, as I find that the transfers adhere much better than onto a polished board. I check the tracks with a magnifying glass before etching to ensure no breaks. Attached is a pic of a custom PCB I made with rub-down transfers (for a digital RPM Counter for a lathe).

Drifting off the original query, but still relevant I hope, for PCBs using artwork I use the laborious process of UV with a home made light box, which involves spraying the board with UV lacquer and developing it, and am a bit long in the tooth to change my ways. However, I’m aware that many people these days are printing directly onto glossy magazine paper using a laser printer and ironing it onto the PCB, but I don’t have a laser printer so can’t try it. I’ve heard varying reports of success rates, but it does have the merit of being virtually free to do. Lots of examples on internet, and this has probably been mentioned on the forum before:

http://www.riccibitti.com/pcb/pcb.htm

I used to print artwork for UV masks directly onto clear acetate which worked like a charm on an HP Photosmart, but when that conked out I made the mistake of changing to an Epson printer, (SX525), only to learn from Epson that their printers don’t support printing onto acetates. (It makes no difference what media setting is chosen). Anyone who might wish to print onto acetate would be well advised to check if their printer lists a ‘transparency’ setting in ‘supported media’. (HP printers seem to list this feature). These are the acetates I used to use:

http://www.amazon.co.uk/INKJET-CLEAR.../dp/B000KJO7BO

As an etching solution for PCB’s I long ago abandoned messy ferric chloride in preference to sodium pesulphate (Na2S2O8). This is an effective and far cleaner alternative to ferric chloride, (the etchant just turns light blue, leaves no 'sludge'). It has a 6 – 8 minute etch time at 45C – 50C and the bath life is 4 – 6 weeks depending on use and operating temperature. It needs to be dissolved in water at a concentration of 200 grams per litre, but a stronger solutions can be made if required. It doesn't work well at below 45 degrees C. (Other uses include etching zinc, picking copper). Available on e-bay for about a tenner for 500g (enough for 2.5L of etchant) post free.

Hope that's of interest.

richrussell · 14th Apr 2014, 3:45 pm

The laser printer toner transfer method has become one of the most popular these days. Most people design their pcb artwork with some form of computer program (there are loads of free ones out there) so it's second nature to print it out. And most people have access to a laser printer at work if not at home. If all you print is black and white, they can actually work out cheaper than inkjets now.

Bazz4CQJ · 14th Apr 2014, 5:09 pm

I do actually have one Dalo pen which I've had since ~1970 (?) which still has some ink in it and is useable.

Biggles · 14th Apr 2014, 6:17 pm

Thanks for all the suggestions. To be honest I rarely make PCBs, maybe one or two a year and just for very simple designs. I am a bit reluctant to try anything too technical for this reason, and rely on the old hand drawn method as I have all the raw materials at hand, well all apart from a decent pen. The Dalo pen seemed to contain an almost thin enamel paint, whereas the modern pens really are just indelible marker ink. I thought that I was leaving the board in too long but last time (this weekend just gone) I made sure the board was out right after the last copper disappeared, but was still left with a streaky finish. Tinning the the tracks will probably be acceptable this time but I think I'll probably just revert to transfers and as David suggests part etch the board to improve adhesion. This whole episode has come about while attempting to copy the AL60 amplifier board as mentioned in another thread. I have two boards etched albeit with poor tracks but they will pass for a couple of prototypes. I had the luxury of using the kitchen in the house as my wife was away this weekend! I think I've managed to get rid of the green etch stains from the worktops.
Alan.

G6Tanuki · 14th Apr 2014, 6:17 pm

Doing it by hand I've found nail-varnish to be a rather good resist-material. You can often pick up 'out-of-fashion' colours from Boots or other drug-stores for peanuts.

When I've done single-sided PCBs they've always been for HF/VHF low/medium-power applications where the principle is always 'leave as much copper as possible to get the lowest impedance'.

In this context a nail-varnish-bottle's brush is great for quick large-scale area-fill.

After etching, nail-varnish-remover strips away the 'mask' and leaves your cuticles wonderfully soft...

Biggles · 14th Apr 2014, 6:28 pm

I might try that. Not sure about going into a shop to buy nail varnish though..I feel a raid on my better half's stock coming on. I suppose darker shades are a bit easier to see on the PCB.
I wonder if it's possible to use a very fine brush for the thinner tracks.
Alan.

dseymo1 · 14th Apr 2014, 6:38 pm

I wonder if nail varnish and the like might work in old-style techical pens?
I'm thinking of the type with a little funnel feeding the tip, used before Rotring and similar pens became popular.

Nickthedentist · 14th Apr 2014, 7:10 pm

What about Tipp-ex pens?

TrevorG3VLF · 14th Apr 2014, 7:25 pm

Is model aircraft dope the same as nail varnish?

kellys_eye · 14th Apr 2014, 8:24 pm

How are you cleaning your boards pre etching?

I find that 'sharpies' work just fine IF you polish the board to a high sheen before use. Do NOT use anything abrasive, not even the green scourers you find in the kitchen. If your board is anything short of 'glass-like' then use 1200 grit wet&dry to get the surface smooth then use T-Cut to get back to a sheen.

If I drill the board prior to using a pen then I also wet&dry the board to de-bur the holes.

Once you have drawn the layout use a ferric chloride solution at about 30C - 40C and agitate the etch continuously until the copper is removed and not a moment longer.

You can purchase bottles of permanent ink to 'overfill' a sharpie and give it a runny-er consistency if you find the pen doesn't deposit enough ink. Quite often a new sharpie will only last one or two resist patterns before the flow dries out to a point where you find yourself scraping off the stuff you've already applied (if you have to go over the tracks to get a more opaque result).

Not sure it tinning solution is still available by I use this on the finished board (or leave the etch resist pen on the surface and solder through it).

The other method I use is the laser toner one. If you have any old CD label sheets or similar self-adhesive label backing sheet then strip off the sticky labels and use the whole sheet, shiny-side up, in your laser printer. The toner almost wipes straight off using your finger after printing so HANDLE IT CAEFULLY and iron it onto a pre-heated board. It takes only a minute to get good adhesion.

The laser toner method is VERY good if you practise it.

Ed_Dinning · 14th Apr 2014, 8:41 pm

Hi Alan, I think RS now do a free PCB etc design suite of software. It is called "Design Spark". I think the design lib has all their common components.

Ed

TonyPhs · 14th Apr 2014, 10:43 pm

I've used a white paint marker with some limited success. It's an edding 780 and has a 0.8mm nib. It would probably be better if used in conjunction with a nice ruler, which I neglected to do and ended up with a wavy pcb track. It certainly resisted my etchant which took around 30 minutes to strip the copper away at room temperature.

13th Apr 2014, 9:22 pm	#1
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Making PCBs with a pen Hi all, can anyone recommend a decent make of etch resist pen for making PCBs using the old ferric chloride method? The permanent marker pens which I bought which were meant to be good enough for the job give very poor results, with tracks etched through where they should remain. I remember the Dalo pen which I used years ago successfully, and I was just wondering what types are best for the job. I don't normally use transfers because I have found that they left hairline cracks in tracks in the past. Alan.

14th Apr 2014, 2:51 am	#2
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,935	Re: Making PCBs with a pen I think you may have answered your own question Alan. Like you, I had good results with the Dalo years ago, but they seem to have disappeared and although some pens are being sold as "etch resistant", I haven't found anything which does the job.

14th Apr 2014, 6:45 am	#3
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Making PCBs with a pen Tiny brush and model enamel paint? I've used car cellulose paint before. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

14th Apr 2014, 7:33 am	#4
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,669	Re: Making PCBs with a pen Tiny brush and bitumastic paint works. Used to use this method to make "Celtic" knotwork jewellery. Andy. __________________ Curiosity hasn't killed this cat...so far.

14th Apr 2014, 9:10 am	#5
daviddeakin Hexode Join Date: Apr 2007 Location: W Yorks, UK. Posts: 407	Re: Making PCBs with a pen I've had sucess with all sorts of generic permenant pens, but only if you go over the lines two or three times, allowing it to dry in between, so you get a nice, thick, opaque deposit of ink.

14th Apr 2014, 10:42 am	#6
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Re: Making PCBs with a pen Hi Guys........ To be honest I found the only reliable way is to laser print onto clear acetate.. UV expose onto Photoresist material.......I am afraid the "Dalo" pen are long gone....If its a very simple pcb, then use a mini drill with a dentist burr and rout out the gaps. Sorry I am forgetting you need to generate the artwork in the first place.... Maplin sell the PCB Wizard software......its very basic but ok for home use.. Regards Wendy G8BZY

14th Apr 2014, 10:54 am	#7
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Making PCBs with a pen There used to be some X-Y computer controlled engraving tables that made proto PCBs Probably too expensive, but I keep thinking of making one.... and a bigger one for a plasma torch! DAvid __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

14th Apr 2014, 10:57 am	#8
arjoll Dekatron Join Date: May 2006 Location: Invercargill, New Zealand Posts: 3,458	Re: Making PCBs with a pen Something like this maybe? It's called a "Dalo Pen" in the Jaycar print catalogue. (edit) showing as out of stock, but may be worth asking them anyway.

14th Apr 2014, 12:21 pm	#9
David G4EBT Dekatron Join Date: Feb 2003 Location: Cottingham, East Yorkshire, UK. Posts: 5,766	Re: Making PCBs with a pen Much closer to home, the pens are available from ESR Electronics at £1.25 each: http://www.esr.co.uk/electronics/products/frame_pcb.htm Lots of other PCB making stuff, (plus components etc). I never had much success with those pens. For small one-off PCBs I find rub down transfers fine, using a soft pencil with a blunt point to rub them down. Having cleaned the bare PCB I dip it in etchant for a few moments and rinse it off, as I find that the transfers adhere much better than onto a polished board. I check the tracks with a magnifying glass before etching to ensure no breaks. Attached is a pic of a custom PCB I made with rub-down transfers (for a digital RPM Counter for a lathe). Drifting off the original query, but still relevant I hope, for PCBs using artwork I use the laborious process of UV with a home made light box, which involves spraying the board with UV lacquer and developing it, and am a bit long in the tooth to change my ways. However, I’m aware that many people these days are printing directly onto glossy magazine paper using a laser printer and ironing it onto the PCB, but I don’t have a laser printer so can’t try it. I’ve heard varying reports of success rates, but it does have the merit of being virtually free to do. Lots of examples on internet, and this has probably been mentioned on the forum before: http://www.riccibitti.com/pcb/pcb.htm I used to print artwork for UV masks directly onto clear acetate which worked like a charm on an HP Photosmart, but when that conked out I made the mistake of changing to an Epson printer, (SX525), only to learn from Epson that their printers don’t support printing onto acetates. (It makes no difference what media setting is chosen). Anyone who might wish to print onto acetate would be well advised to check if their printer lists a ‘transparency’ setting in ‘supported media’. (HP printers seem to list this feature). These are the acetates I used to use: http://www.amazon.co.uk/INKJET-CLEAR.../dp/B000KJO7BO As an etching solution for PCB’s I long ago abandoned messy ferric chloride in preference to sodium pesulphate (Na2S2O8). This is an effective and far cleaner alternative to ferric chloride, (the etchant just turns light blue, leaves no 'sludge'). It has a 6 – 8 minute etch time at 45C – 50C and the bath life is 4 – 6 weeks depending on use and operating temperature. It needs to be dissolved in water at a concentration of 200 grams per litre, but a stronger solutions can be made if required. It doesn't work well at below 45 degrees C. (Other uses include etching zinc, picking copper). Available on e-bay for about a tenner for 500g (enough for 2.5L of etchant) post free. Hope that's of interest. Attached Thumbnails __________________ David. BVWS Member. G-QRP Club member 1339.

14th Apr 2014, 3:45 pm	#10
richrussell Heptode Join Date: Jul 2008 Location: Selby, North Yorkshire, UK. Posts: 979	Re: Making PCBs with a pen The laser printer toner transfer method has become one of the most popular these days. Most people design their pcb artwork with some form of computer program (there are loads of free ones out there) so it's second nature to print it out. And most people have access to a laser printer at work if not at home. If all you print is black and white, they can actually work out cheaper than inkjets now.

14th Apr 2014, 5:09 pm	#11
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,935	Re: Making PCBs with a pen I do actually have one Dalo pen which I've had since ~1970 (?) which still has some ink in it and is useable.

14th Apr 2014, 6:17 pm	#12
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Making PCBs with a pen Thanks for all the suggestions. To be honest I rarely make PCBs, maybe one or two a year and just for very simple designs. I am a bit reluctant to try anything too technical for this reason, and rely on the old hand drawn method as I have all the raw materials at hand, well all apart from a decent pen. The Dalo pen seemed to contain an almost thin enamel paint, whereas the modern pens really are just indelible marker ink. I thought that I was leaving the board in too long but last time (this weekend just gone) I made sure the board was out right after the last copper disappeared, but was still left with a streaky finish. Tinning the the tracks will probably be acceptable this time but I think I'll probably just revert to transfers and as David suggests part etch the board to improve adhesion. This whole episode has come about while attempting to copy the AL60 amplifier board as mentioned in another thread. I have two boards etched albeit with poor tracks but they will pass for a couple of prototypes. I had the luxury of using the kitchen in the house as my wife was away this weekend! I think I've managed to get rid of the green etch stains from the worktops. Alan.

14th Apr 2014, 6:17 pm	#13
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: Making PCBs with a pen Doing it by hand I've found nail-varnish to be a rather good resist-material. You can often pick up 'out-of-fashion' colours from Boots or other drug-stores for peanuts. When I've done single-sided PCBs they've always been for HF/VHF low/medium-power applications where the principle is always 'leave as much copper as possible to get the lowest impedance'. In this context a nail-varnish-bottle's brush is great for quick large-scale area-fill. After etching, nail-varnish-remover strips away the 'mask' and leaves your cuticles wonderfully soft...

14th Apr 2014, 6:28 pm	#14
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Making PCBs with a pen I might try that. Not sure about going into a shop to buy nail varnish though..I feel a raid on my better half's stock coming on. I suppose darker shades are a bit easier to see on the PCB. I wonder if it's possible to use a very fine brush for the thinner tracks. Alan.

14th Apr 2014, 6:38 pm	#15
dseymo1 Retired Dormant Member Join Date: Dec 2007 Location: Shropshire, UK. Posts: 3,051	Re: Making PCBs with a pen I wonder if nail varnish and the like might work in old-style techical pens? I'm thinking of the type with a little funnel feeding the tip, used before Rotring and similar pens became popular.

14th Apr 2014, 7:10 pm	#16
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,864	Re: Making PCBs with a pen What about Tipp-ex pens?

14th Apr 2014, 7:25 pm	#17
TrevorG3VLF Rest in Peace Join Date: Apr 2011 Location: Matlock, Derbyshire, UK. Posts: 1,378	Re: Making PCBs with a pen Is model aircraft dope the same as nail varnish?

14th Apr 2014, 8:24 pm	#18
kellys_eye Octode Join Date: Jan 2014 Location: Oban, Scotland, UK. Posts: 1,129	Re: Making PCBs with a pen How are you cleaning your boards pre etching? I find that 'sharpies' work just fine IF you polish the board to a high sheen before use. Do NOT use anything abrasive, not even the green scourers you find in the kitchen. If your board is anything short of 'glass-like' then use 1200 grit wet&dry to get the surface smooth then use T-Cut to get back to a sheen. If I drill the board prior to using a pen then I also wet&dry the board to de-bur the holes. Once you have drawn the layout use a ferric chloride solution at about 30C - 40C and agitate the etch continuously until the copper is removed and not a moment longer. You can purchase bottles of permanent ink to 'overfill' a sharpie and give it a runny-er consistency if you find the pen doesn't deposit enough ink. Quite often a new sharpie will only last one or two resist patterns before the flow dries out to a point where you find yourself scraping off the stuff you've already applied (if you have to go over the tracks to get a more opaque result). Not sure it tinning solution is still available by I use this on the finished board (or leave the etch resist pen on the surface and solder through it). The other method I use is the laser toner one. If you have any old CD label sheets or similar self-adhesive label backing sheet then strip off the sticky labels and use the whole sheet, shiny-side up, in your laser printer. The toner almost wipes straight off using your finger after printing so HANDLE IT CAEFULLY and iron it onto a pre-heated board. It takes only a minute to get good adhesion. The laser toner method is VERY good if you practise it.

14th Apr 2014, 8:41 pm	#19
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Making PCBs with a pen Hi Alan, I think RS now do a free PCB etc design suite of software. It is called "Design Spark". I think the design lib has all their common components. Ed

14th Apr 2014, 10:43 pm	#20
TonyPhs Retired Dormant Member Join Date: Apr 2014 Location: Bridgend, Wales, UK Posts: 52	Re: Making PCBs with a pen I've used a white paint marker with some limited success. It's an edding 780 and has a 0.8mm nib. It would probably be better if used in conjunction with a nice ruler, which I neglected to do and ended up with a wavy pcb track. It certainly resisted my etchant which took around 30 minutes to strip the copper away at room temperature.