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David Ashton
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Ferric Chloride
David Ashton   10/15/2013 6:04:09 PM
Fossicking aorund on the internet, I found the "mystical bubbly reaction" that makes ferric chloride:

Hydrogen peroxide can reduce iron(III) ions to iron(II) ions:

H2O2 + 2Fe3+ -----> 2H+ + O2 + 2Fe2+

If you really want the full equation, it would be

H2O2 + 2FeCl3 -----> 2HCl + O2 + 2FeCl2

I see it turns some of it back into Hydrochloric Acid (HCl) which must be why it was so unkind to clothes......

Crusty1
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Re: Ferric Chloride
Crusty1   10/16/2013 3:48:52 AM
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Hi David,

Much the same circuit board development time line for me. I somehow seem to be stuck in the Veroboard trap, I use Tiny Cad to capture the circuits and VeeCad to layout the Veroboard circuit, saves a lot of heart ache from putting a link or hole in the wrong place.

Now I am getting forced to use SMD footprints I have got my head around Eagle but not yet Design Spark, I like Cad drawing system that give a 3D view of the components and circuit, but free versions seem hard to find, or ones not with some user limit. My pension makes me a miser, just as I was when I had only pocket money.

Good Article forgot how the Dalo pens inked up my fingers.

David Ashton
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Re: Ferric Chloride
David Ashton   10/16/2013 4:39:09 AM
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@Crusty1 thanks....re SMD I did something with them not too long ago and successfully used my Niche PCB designer for it.  There might be something on that in the not too distant future.  You're certainly more adventurous than me with new stuff!   I'm not yet on pension but have a wife and a mortgage....'nuff said....

Crusty1
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Re: Ferric Chloride
Crusty1   10/16/2013 5:00:55 AM
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Hi David,

At the level I am working at in retirement I think I am going to get my first PCB fabed using Fritzing, Just seen the link here on ee-times. I like the intuitive bread boarding approach and they have a 6502 processor outline already so the shield I want to build for the Papilio One to emulate the UK101 looks a distinct possibility.

May be max would like an article on starting out with Fritzing?

David Ashton
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Re: Fritzing
David Ashton   10/16/2013 5:42:41 AM
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Hi Crusty....  "May be Max would like an article on starting out with Fritzing?"

I'm sure he would, but best get it from the horse's mouth.

Meanwhile, could you post a link either to it or to the EET article where you saw it?

 

Crusty1
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Re: Fritzing
Crusty1   10/16/2013 6:31:04 AM
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@ David, Max

The EE-Times  link is here http://reprap.org/wiki/PCB_Milling

Funny thing the link was in one of your posts.

Klick to the section on Fritzing, I especially like it as it is available for Mac OS.

They seem at home with SMD, so I am very much going to give it a go.

@Max if you can with stand furthur articles from Crusty Mansion's then I will write a piece about getting my first Fab done by Fritzing?

Direct link is http://fritzing.org/

Best Crusty

David Ashton
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Re: Fritzing
David Ashton   10/16/2013 7:42:00 AM
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@Crusty...."Funny thing the link was in one of your posts."   Yeah right, I'm getting old.....if you'd said reprap I would have cottoned on.... :-)   I kinda skimmed thu the article at the time, thinking I would get back to it.  Good thing you have a longer attention span!

Crusty1
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Re: Fritzing
Crusty1   10/16/2013 8:56:32 AM
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@David :  Good thing you have a longer attention span!

Mrs Crusty thinks I do not have enough attention span for the things she thinks are important and that I have a far too permenant attention span to things electronic.

Probably enough said

grover_gren
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Re: Ferric Chloride
grover_gren   10/21/2013 4:29:37 AM
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Dave you are not the only 'dinosaur' out there! I still use veroboard for prototyping, but the crepe tape, UV light box, and caustic soda / hot ferric chloride baths have not been out for a few years now. You talked about SMD - my solution was to find an ebay supplier of SMD to 0.1 pitch adapter boards to interface to veroboard :-) Though hand-soldering the devices in place has taken some practice...  

In my time I have seen some veroboard monsters though, sorry to say but they have been mainly from hobbyists or apprentices. The classic is 240VAC mains wired straight into the veroboard to a flatpack-mounted transformer, with the copper tracks intact except for one small break by a hand-twisted 3mm drill, the tracks then running under the transformer into the secondary low-voltage side!

David Ashton
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Re: Ferric Chloride
David Ashton   10/21/2013 5:58:04 AM
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Hi Grover1.....I've thought about getting some of those SMD adapter boards as I got some very nice SMD audio compressor ICs off some old radio boards.  Theoretically I could make my own - Niche PCB designer can do stuff like that - but probably cheaper and less hassle to buy.

I've also seen some shockers with mains on veroboard.  I DID do it myself once, but actually stripped a couple of whole tracks off either side of the live one and took out 3 or 4 holes with my cutter,  I still was not happy.  

For a good veroboard cutter you need a 4 mm Drill, 3mm might leave a trace of copper on the side and then you have problems....And mine's in a nice holder to give you some torque.

kfield
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Re: Ferric Chloride
kfield   10/16/2013 10:15:57 AM
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@davidashton David, sounds like you had as much fun messing around with chemistry as you did with electronics!

David Ashton
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Re: Ferric Chloride
David Ashton   10/16/2013 6:12:12 PM
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@Karen I quite enjoyed Chemistry at school and had a couple of chemistry sets at home too.  Of course these days the chem sets (and the teaching at school) are pretty tame.  I remember our chem teacher at school would not let us see what happened when sodium reacted with water.  So my friends and I hatched a plot...we stole some sodium from the lab, I carried it home in my pocket wrapped in oily tissue in a plastic bag (It was kept under oil in the lab as it reacts with air).  At home we chucked it in our swimming pool.  It rose to the surface, bubbling furiously and then exploded.  To this day I get cold shivers wondering what would have happened had it started combusting in my pocket.

zeeglen
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Re: Ferric Chloride
zeeglen   10/16/2013 8:33:00 PM
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Back in college a couple of us students had summer internships, one day we were assigned the task of servicing the PCB etching machine.  This was a small tub on wheels that used a magnetically-coupled impeller to slosh the feric chloride around while the pcb remained stationary.  I forget whether it was just a cleaning or if we had to replace the pump impeller, but whatever it was necessary to first remove the ferric chloride.

We undid the drain on the tub and collected the ferric chloride in a plastic bucket.  After we finished servicing the system I started pouring the ferric chloride back in.  About a quarter-bucket later I suddenly remembered - "The drain plug!"  Was quite a mess and took a lot of paper towels, but the tray shelf in the bottom of the cart caught most of it.  Fortunately none of the profs noticed.

David Ashton
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Re: Ferric Chloride
David Ashton   10/16/2013 9:02:11 PM
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@Zeeglen - even when it's not my vile HCl / FeCl3 mix, it's certainly not stuff you want to chuck around the place.  I've often thought, when I'm sloshing a PCB back and forth in an old icecream container, that I must make a bubble etcher - like a thin aquarium tank with a tube with holes at the bottom connected to an aquarium pump to blow bubbles thru the liquid to agitate it.  Maybe a heater as well....   Then I don't make another board for a couple of months and the idea vanishes till the next time.....

zeeglen
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Re: Ferric Chloride
zeeglen   10/17/2013 12:42:45 AM
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The wierd thing was that I had never made that dumb mistake when changing the oil in my car.

antedeluvian
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Me too!
antedeluvian   10/16/2013 10:28:48 AM
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David

Our progression through PCB layout tools sounds quite similar as I described in Max's How it Was series. However I never tried making my own PCBs until after university and then only once.

When you said that Rhodesia was not the centre of the electronics universe, you were understating by a long shot. In 1967/8 my electronics course was mainly valves (tubes to the the bilingually challenged) and you certainly didn't need PCBs for those. I know that I have a few years on you and I was in Bulawayo and not Salisbury, but my teachers were never of the goto variety. They were more of the talk softly (and by that I mean little content) and carry a BIG stick variety. My physics teacher even suggested that I was no good at electronics and that I should give it up. 45 years later I reflect and think maybe he was right!

David Ashton
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Re: Me too!
David Ashton   10/16/2013 6:22:28 PM
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@antedeluvian  Hi Aubrey....I did read and comment on your How it Was on the subject.  You certainly got a lot further with the computerised stuff than I have - I gotta learn one of the tools soon.   Watching the track pattern come out on the board as you develop it always gives me a thrill - like developing your own photos did.  Your descriptions of waiting an hour for the display to pan are a graphic reminder of how PC performance used to lag behind software requirements in the old days - though that seems to be a problem still, I doubt users these days would wait an hour!

Duane Benson
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Very interesting article
Duane Benson   10/17/2013 7:19:25 PM
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David - I've used the black tape and pen from Radio Shack, but never a Vero board. I didn't have much luck etching the PCBs though, so I tended to fall back to wire-wrap or proto-board.

These days, we're kind of in a golden age or tools and suppliers. I'm contstantly amazed at how much we can do these days, with free or inexpensive tools. Not to mention, the wealth of information at our dispoal.

Back in the 1980's, I tried to design a Caller-ID system. The phone company had just started sending the information down the phone line prior to the ring signal, so it was possible, but no one was selling the things yet. It proabbly took me six months or more of searching, calling, ordering documents & repeat before I found enough documentation to get close. The same would probably take me about 20 minutes now.

David Ashton
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Re: Very interesting article
David Ashton   10/18/2013 4:18:03 AM
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@Duane...  Vero board, to you, would be akin to spark transmitters.   Nevertheless for guys like me it has its place.  I was looking at Crusty's  recommended Vee-cad, which works out layouts for you, and might give that a go.   

Ref your documentation searches.  I occasionally think about how complicated our lives are with internet and mobile phones and stuff, but then I think of the time I spent trying to get datasheets in those days,  As you say, usually it's a couple of clicks now  But I still think these things are double-edged swords....

Duane Benson
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Re: Very interesting article
Duane Benson   10/18/2013 3:53:26 PM
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David - I expect that I had considerably easier access to documents than you did, but I still had to drive an hour and a half and promise voluminous future purchases to get one the the many data books I ended up with.

Crusty1
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Re: Very interesting article
Crusty1   10/21/2013 6:10:53 AM
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@David, I like the idea of Veroboard being in the realms of a spark gap transmitter. got myself into a moderate trouble by building a spark gap transmittero on Veroboard  and opertaing it, as a teenager.

I have found a good marriage in TinyCad and VeeCad for Veroboard layout. They are cheap or donation supported and do not take up much disk space, so I like them as a tool.

I think I am going to stick with learning to use RS Design Spark for my PCB's, as it's no cost and no limitations at the level I need and the fabrication is resonably low cost. it also has 3D view built in, which I find I need to visualise component placement for mistakes.

I should have an 8 digit alphanumeric display (calculator style led bubble) working on the Papilio One, as a Veroboard shield in my next blog on APP, I will publish circuit drawing and VeeCad layout with the blog.

I think I may like the Fritzing system for PCB design especially as it is open source. Their StripBoard (Veroboard) option, is however very slow on large prototype boards. I do however like the Breadboard to Schematic to PCB approach, they are using.

I also like Eagle  but find the free versions limitations to be too limiting.

However as you all know by now I am a cheapskate

Max The Magnificent
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Re: Very interesting article
Max The Magnificent   10/21/2013 11:25:13 AM
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@David: I was looking at Crusty's  recommended Vee-cad, which works out layouts for you, and might give that a go.  

I'd forgotten all about VeeCAD -- (http://veecad.com) I never used it, but I've heard of it and it does look very tasty -- if you do try it out, pehaps ypu could write a blog about it here.

David Ashton
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Re: Very interesting article
David Ashton   10/21/2013 3:56:50 PM
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Hi Max, Crusty....  I also had a look at Vee-cad and it does look tasty.  If I had a dollar for every hour I've spent working out veroboard layouts, I'd be rich enough to buy a couple of rounds.    Max, I'll add it to the list.  As always, don't hold your breath..... 

Crusty1
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Re: Very interesting article
Crusty1   11/1/2013 1:16:01 PM
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@David : I have always run Tiny Cad with VeeCad and whilst the two do not forward and back anotate they seem to co-exist well.

I have just downloaded FreePCB and this is supposed to link with Tiny Cad output, so I shall now be trying this out. FreePCB is also linked to a Free router software so all this will be in the melting pot with me over the nex few weeks.

 

 

 

Sergio8421
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Re: very interesting article
Sergio8421   10/23/2013 10:33:03 AM
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Hi David

All this brings back old memories of ferric chloride stains and blue fingers, indeed!


I had a pcb pen, but the results were rather poor, as the ink didn't survive much to the etchant. I had a preference for using a thick, gummy, messy blue ink that came in medicine-like bottles from a local supplier, using the finest-pointed brush that I could find. Results were fairly good at times, even if often requiring a little reworking here and there. I also managed to etch a double-layer circuit a couple of times. I must still have all these somewhere in the basement!

Some electronics magazine included a layout for their pcb, that I transferred (as a drawing guide) from the magazine page to the copper-clad board with the aid of a veeery vaxy, dirty, sticky blue carbon paper sandwiched between the two. Too bad this precious, old fashioned item soon disappeared from the local market, replaced by a new "improved" carbon paper proudly advertised as non-staining, but alas, completely useless for the purpose..

For one of my first experiments with photoresist I managed to have a copy of the pcb layout on acetate, thanks to a relative who had access to a xerox copier at work - they were a luxury at the time. All went quite well, the pcb was etched, drilled, and I begun assembling the circuit, whose main component was a big DIL chip..only to discover that the photocopying process had somehow shrunk the pattern..and I had all the pitches wrong!

David Ashton
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Re: very interesting article
David Ashton   10/23/2013 4:59:42 PM
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@Sergio... "the photocopying process had somehow shrunk the pattern..and I had all the pitches wrong!"

Dont'cha hate it when that happens?   Happened to me once too!

Sergio8421
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Re: very interesting article
Sergio8421   10/25/2013 4:34:26 AM
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@David

Oh yes, definitely!

I must say that I didn't pursue the photo technique much further, soon reverting to good old ink & brush - at least as long as spare time for hobby lasted, that is, not for long.

Now in my daily job as an EE, sometimes during the prototyping stage of a new project when I need small PCBs made in short time and low cost, I have them made at a CNC mill service. Results are excellent, down to 8mils trace width / clearance. 


Admittedly, tne new DIY techniques as toner transfer, P&P, and the like, are very intriguing. I ought to give them a try some day.

anon3887601
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everything home-made
anon3887601   10/23/2013 8:18:33 PM
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Ah David

I've done everything you described myself (apparently we are exactly the same age and had the same resources), except for making my own ferric chloride.  My high school chemistry teacher would give me some.  Later as a university student I worked at a small electronics manufacturer and learned of ammonium persulphate.  Much better in my opinion.

I still make my own pcbs.  However I could never get the photo process to work, positive OR negative.  In fact all these years later I still have an almost-full quart bottle of Kodak negative resist.  I had the whole works, UV lamps, light table, exposure frame, darkroom with red lights, and it just never worked.  Negatives would be fogged, and the traces from the positive resist technique would be fuzzy.  So I continue to use up all the Bishop Graphics tapes and IC patterns and the 3M Rubylith by sticking them directly to my blank board then etching.  It works.

I've been an ELEKTOR subscriber for 35 years and made many of their "old style" boards.  I prefer that approach for my own boards to this day because it uses less etchant!

Cheers, Wayne

David Ashton
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Re: everything home-made
David Ashton   10/23/2013 8:38:22 PM
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Hi Wayne

I'm glad there are some other DIY PCB tragics out there.   You should give the photo process a go if you can get Positiv20 or (better) presensitised boards.  Get yourself a picture frame a bit bigger than the biggest board you will want to do.  Remove the back and if necessary stick or otherwise fix the glass in place.  Fix it on to a bit of wood a bit bigger again, with a hinge on one side.  Where the picture should be put a bit of foam to hold your board against the glass.  Get some way to hold it down while you're exposing (I just used a nut and bolt arrangement).  You then have your exposure frame - just put the board and the positive on top of the foam and carefully close it.  as above, 5 min for Pos20 or around 45 sec - 1 min for the presensitised stuff.  Depends on the sunlight where you are.  I'll try post a pic if you wish.

I tried Bishops direct on the board once - don't you find the etchant seeps underneath it?  (mind you I got that with my old FeCl3 / HCL etchant which could probably dissolve stainless steel.... :-)

The old Elektors were GREAT for DIY PCB'ers...

Cheers // David

anon3887601
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Re: everything home-made
anon3887601   10/23/2013 9:30:58 PM
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Hi David

No problem using the Bishop tape directly on the board, except that the edges are sometimes fuzzy because the glue seeps out from underneath the tape.  A little scraping with an XActo knife fixes that.  I use the knife to separate the pads on IC and connector patterns too.  For very fine lines the Rubylith tape is better.

Actually the BEST of all DIY stuff was direct rub-down patterns that were like Letraset.  The European one was called Ceresist, in the US Vector made it and called it Vectoresist.  I wish they were still available.

Cheers, Wayne

David Ashton
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Re: everything home-made
David Ashton   10/24/2013 2:39:05 AM
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@Wayne....In the article I mentioned an iron-on PCB system....here's a page for it

 

http://www.pcbfx.com/main_site/pages/start_here/overview.html

 

Looks interesting, I might give it a try sometime.  Have you ever used this?

CryptomanTR
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Re: everything home-made
CryptomanTR   10/24/2013 4:06:46 AM
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@David


I have used the heat transfer method with many variations. I have also used the  paper you have shared in your link. I used the TTP without the toner foil which provides the protection. The results were quite poor (given the cost of these products).

I have also used the iron rather than the laminator, which will make a difference. Obviouslu, one needs a good laser printer for this method to work as well.

I have used other (cheaper) glossy papers in the past and they have also worked well. I must warn that while getting rid of the paper, you will need to be patient while soaking and gently washing the paper off the PCB. If you rush this stage, you will damage the carbon tracks printed to the copper board!

I think the suppliers of heat transfer related products oversimplify the PCB developing process. This process does give good results but you need a lot of trial and error before you can perfect the technique to suit your needs.

 

David Ashton
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Re: everything home-made
David Ashton   10/24/2013 4:11:20 AM
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@Wayne Thanks for that, it's always good to get past the advertising hype....

David Ashton
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Re: everything home-made
David Ashton   10/24/2013 4:14:32 AM
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Sorry, above comment should have been addressed to @Cryptoman, sorry I was on autopilot there......

dhlocker1
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Re: everything home-made
dhlocker1   10/24/2013 7:50:24 AM
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I'm surprised that this thread has not included mention of Kicad (a free (as in Free Beer and Free of License restrictions)), a suite of ECAD programs. Far better than Eagle (IMO - I never really "got" Eagle) and nearly as simple as Design Spark, without the vendor tie-in.


The homebrew PCBs Yahoo! group also has a wealth of information and knowledgable people. <http://groups.yahoo.com/group/Homebrew_PCBs> who all do toner-transfer, positive and negative photoetch, isolation milling, and etching with  FeCl, CuCl, Ammonium Persulphate, HCl/H2O2, strong coffee, ...

I do an occasional board, but nowhere near as many as I'd like. Kicad, toner transfer (with inkjet paper), HCl/H2O2, hand solder are my usual toolchain.

David Ashton
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Re: everything home-made
David Ashton   10/24/2013 3:07:14 PM
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@dhlocker1, thanks for that info and link, I'll bounce over there when I have a second and take a look.   Forums like that can often save you hours of experimentation and sometimes tears (as in wailing and gnashing of teeth :-)  when you have problems with an existing tool or are trying to select a new one.

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