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[jamiewoody]

i have no idea about this. i've never done this, but really want to learn!

what do i need? what products do i buy? what sort of environment do i need to create for this?

when i have what i need, what do i do?

this seems like the way to go, and would be a short cut in the long run. so far, instead of just copying layouts people post on the web (wsg, etc), i have been  "redrawing" layouts, then connecting resistor pins directly to ic pins, etc through perf-board. this method has worked, and has forced me to learn how things fit together. but, i am ready to "graduate" from this!

also, on a semi-different subject? what about solder pens? wow. a $20 pen! how permanent are they? do they hold up? are they strictly for repairing scratched pcbs? or can you actually "draw" a whole pcb with one?

[Gordonjcp]

There's a couple of ways of doing it, but they all boil down to the same thing - get some copper-clad board, clean it thoroughly, apply some etch-resist to the bits where you want to leave copper and dunk it in etchant.

Now normally you use slightly warm ferric chloride solution for etching PCBs.  With a name like "ferric chloride" it sounds just like the sort of stuff that will burn holes in your jeans and stain the toilet orange - and it is!  You want to be pretty careful with it.

You get stuff called "press'n'peel" that you laser-print onto and then stick to the PCB by ironing it on.  You can also do this by laser-printing onto nice smooth paper and ironing *that* onto the copper, then soaking the paper off with water.  The toner stays stuck to the PCB and prevents the ferric chloride from etching off the tracks.

If your tracks are a bit thin or bitty in places, you can draw them in with an etch-resist pen, or you can draw the whole board freehand like that.  Overhead projector pens and freezer pens can work quite well, as long as they're solvent-based.

Expect to ruin a lot of PCB material before you get it right.

[electoyd]

I would second that Gordon, be prepared to make a mess of wherever you do this, the ferric chloride will bleach clothes and stain anything else it touches.

[Bogus Noise]

also, on a semi-different subject? what about solder pens? wow. a $20 pen! how permanent are they? do they hold up? are they strictly for repairing scratched pcbs? or can you actually "draw" a whole pcb with one?

Bought one of those pens for repairing a board... bit pricey! Later discovered you can get conductive paint for a lot less - would definitely recommend buying that instead.

Haven't tried using either to make a PCB - I imagine it'd be good for repairing traces that haven't etched properly but pricey for making a whole PCB - but thought you'd like the heads up on the paint anyway

[Dylan]

This is something I've been looking into doing as well. You may want to check out this video Circuit Skills: Circuit Board Etching

[Gordonjcp]

Not bad for a first attempt:

http://twitpic.com/3gjwsv

This is the Yusynth Steiner VCF PCB from here:
http://yusynth.net/Modular/EN/STEINERVCF/index.html

I printed it out (on ordinary copier paper, should have used shinier paper) then ironed it onto some PCB trimmed to the size of the board layout.  Quite a bit of the edge tracks came away, so I drew those in by hand.  The etchant was pretty hot when I did that, and it took about ten minutes to etch.

Picking the hairy photocopier paper off was a pig of a job.  Next time I *will* use shiny paper ;-)

[jamiewoody]

well, my first attempts at cpb printing will be to fabricate boards already designed. but, legal, as it would be from sites like WSG where the owner of the design put prints up for download for a reason...

the more mature i get at this sort of thing, i will make my own designs, print and burn them. does the print mechanical have to come from a lazer printer? or could i set up an ink jet at 600dpi and go at it? i guess i could always cut amber lith like in the old days...

the holes would be important, as i would want the components to be in their proper places. thoughts?

[Z3R0]

Here's my first attempt. Bare in mind i had never tried this and only had what i thought may or may not be right to go on in terms of how much to iron the print and how long to etch it for.




And my second attempt with my own design.. Not quite so good, not pretty and they need some tlc. But they work and that's what matters..



The resolution doesn't really matter. Just use a laser printer with a good toner cartridge. Go to the printers and use theirs.

[Z3R0]

the holes would be important, as i would want the components to be in their proper places. thoughts?

Other peoples boards are a good place to start. Try a couple of simple guitar fx pedals or something small so as not to waste much paper/board in the process of learning how to do it.

You can also store the ferric chloride for use later. It has to be warm to work. There is probably an optimum temperature but i find number 2 on an electric cooker to be good. About 5 minutes or so to etch a board.


Here's what the boards i've made become:

Ironically named after my ex girlfriend (K) as an apology for the torment she had to endure in listening to my banal banter about this nonsense while figuring out this and other utterly boring tech stuff.....

http://www.youtube.com/watch?v=d9fqCiSuUjQ

Geek psychosis got the better of me        

[jamiewoody]

i suppose a small, precision drill press would not hurt for this.

[Z3R0]

Absolutely not. It helps. Doing it freehand would be a chore to say the least.

[Gordonjcp]

They look pretty good!  Your Yusynth Steiner VCF came out better than mine.  I wonder if yours is as keen to pick up AM radio as mine is, when it's built? ;-)

[Z3R0]

I've got a load of those. i went a bit mad when i made the first one. Shame the whole +/- power supply suprise ruined my fun. Clipping two 9v batteries together works but it's not exactly ideal when you want to build a filter into something.

I suppose i could sell them off for cheap to anyone wanting to buy them. Seems a shame to throw them away.

Radio signals... Yes, i had this with a simple filter i built that i found here:

http://www.fluxmonkey.com/electronoize/opampFilter.htm


It's simple and it does work but it HUMS so loudly it's pretty much useless for anything beyond very lo-fi and noise. While trying to eliminate the hum in various ways i ended up picking up some french radio. I think that was the point where i got the ferric chloride and boards out and decided to see how good my ironing skills were.

[Gordonjcp]

Well further down on that page is a design for one that runs off a single 9V supply.  I run mine off about 15V with a pair of resistors to generate the 0V rail.

You could modify the Steiner design to be more like the guitar synthesizer one.  It'll probably work okay as it is off 4.5/-4.5 *but* you'll need to adjust the resistors around the cutoff control.

[Z3R0]

Yeah that's the one i meant. The little single 9v one. HUMMMMMMM......


But the fact it actually worked impressed me briefly..

How did you use the resistors to provide the 0v rail. Is it the same principle as the voltage divider on that link i posted?

I tried a few things but just couldn't get it to work. I guess it is possible it was a bad built. Not being able to get the Ken stone one i bought ages ago to work either though. It all got a bit disheartening....