thinking about trying to make a PCB-

Started by plexi12000, August 04, 2015, 01:47:24 PM

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plexi12000

hi dudes..... there's so many cool circuits i'd like to try, but you need a pcb.  or i guess veroboard is another option too.

i saw that smallbear has a nice little beginner, 'everything you need' kit to make pcb's.  seems like a reasonable price, as well.

after a quick review of their instructions, i THINK i can handle it.  i have a photocopier at the house so that's covered.

before i jump in the deep end......just thought i'd pick some experienced brains!   Any comments, advice, pros, cons to look out for...would be greatly appreciated!

thank you

Kevin Mitchell

#1
Etching & even designing a board isn't too hard! The first thing I've done when I took interest was went over to the department store, grabbed a bottle of muriatic acid, acetone and some hydrogen peroxide along with a roll of paper towels. All of that for ~$20 and I have well more than I need -also a supply of copper clad boards.

There's a program called DIYLC which is a great program for beginners wanting to design board layouts whether it be vero or your own PCB of course you need to know how to read a schematic properly (easy as pie)

I've jumped into the deep end myself. The only side effect (which still happens) is ordering inappropriate parts or a simple wiring mistake. Live and learn  8)

Using the muriatic/peroxide solution isn't that messy for making PCBs. Perhaps it's the grade acid I have picked up but the reaction seems a bit slow at first but once it gets going, it goes. Make sure you take all safety precautions and do it in a well ventilated area. Water that stuff down dramatically when disposing.

-Never etch a board you are unsure about. When printing the PCB traces make sure you make plenty of spare ones in cause the toner doesn't transfer well or if cleaning up with a sharpie seems hopeless.

There are plenty transfer and etching methods around for you to dabble with.

Practice makes perfect.
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Kevin Mitchell

Forgot to add... Dremel tool. Get a decent one and a bit adapter to drill holes in your PCBs. A press would be useful too but not necessary. (something I have forgotten myself in the moment)
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mth5044

There are those of us that don't... like to get our hands dirty  :icon_lol:

I prefer a nice layout program (I use eagle) and a small quantity fab house (I use OSH park). IF DIY in your garage is cheaper, you don't get the small trace resolution, double sided, silk screen and way lower chance of unconnected traces, not to mention chemical hazards.

But there are a lot of people who etch at home, so there must be something about it.

vigilante397

I started on vero boards and moved onto etching my own boards because A) there were a lot more awesome layouts available, and B) assuming I was careful in the etching process it was a lot harder to mess up. I used toner transfer with ferric chloride and it worked great, just a bit messy. The only tip I really have is that surface preparation is everything. If you don't take the time to do things right before the actual etch, then the etch will not go very well.

I eventually decided I didn't like the amount of work that goes into etching and my wife hated the chemicals, and I didn't want to go 100% with external production (partially because I like the DIY aspect and partially because I know my layout skills aren't perfect so I like being able to fix mistakes before paying for multiple boards), so I bought myself a desktop CNC machine and am thrilled with the ease of use and the quality. But I digress.

Thinking about trying to make a PCB? DO IT! ;D
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LiLFX

I fabricate PCBs as my day job, and before that I was etching boards at home for about a decade. I have a lot of random thoughts...

Have a dedicated space with access to running water. Do not use a metal sink. Do not bring these chemicals into your kitchen or anywhere food or drink will be prepped. All of your dishes and measuring devices should be dedicated to this only and not be used for anything else. Even a small etchant spill can have disastrous results. If you have children in the house be extra cautious. Basically, don't etch in any area of the home that you don't want destroyed. Always wear glasses. Always wear gloves. It you are doing toner transfer buy a laminator instead of an iron. Always start with clean copper (scour with clean scotchbrite and clean with alcohol) before trying to transfer.

Some of this might sound over cautious, but you only have two eyes, and nobody wants to deal with a chemical spill. After you etch a bunch of boards you'll get comfortable and assume it's safe. It's not. The chemicals are dangerous. The fumes are dangerous.

I'll try to think of more stuff....generally though....safety first.

plexi12000

thanks a lot boys!  i wanted to get a feel for what i might get myself into with this! -lol  I guess i'll take a swing at it.

vigilante397----   i think i recall the instructions said to scour the copper REALLY clean.  Is that what you meant w/ surface prep?

vigilante397

Quote from: plexi12000 on August 04, 2015, 07:31:44 PM
vigilante397----   i think i recall the instructions said to scour the copper REALLY clean.  Is that what you meant w/ surface prep?

That's part of what I meant. It absolutely needs to be unreasonably clean. I also found out that some of the copper clad I bought once had a plastic coating on it that ferric didn't dissolve but I didn't completely scour it off so the etch didn't work :P

But I was also referring to making sure the transfer is perfect before starting your etch. I had a couple of special "industrial" permanent markers that could withstand most chemicals that I would use to touch up the traces as necessary when the transfer wasn't perfect. This makes a big difference, especially when you aren't as patient with your ironing (like myself) as you should be.
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Kevin Mitchell

Here's what I chose for dremel stuff in case you're in the market for them. Very pleased with this stuff!
Dremel Tool
Dremel adapter
PCB bits

Probably the most costly tool w/ a decent soldering iron entering such hobby. I've etched my 1st board before having any soldering experience or pretty much any experience what so ever in pedal building. I said I dove in head first! It's surprisingly simple once you know the ropes. And ridiculously efficient.

Here's some single sided clad boards as well.
Have a saw handy when cutting chunks out of your clad board. Also sand paper to clean the edges.

When you "prep the board" for the toner transfer rinse the board under tap and polish with very fine steel wool or sand paper. Wipe down with a sterile cloth and put aside for the transfer. Clean with rubbing alcohol right before you start the transfer. Any residue will flaw the transfer. Make sure you use glossy paper (photo paper or a glossy magazine page) when printing your transfer. Get a feel of the paper you're using, the size of the board and how long to iron the transfer on. I guarantee it wont be perfect the 1st time. So wet sand the bad transfer off and try again. Any fresh black sharpie is great for patching up a slightly imperfect transfer. I mean little lines, dots or solder pads that need a little rounding off. You can scrape toner off the PCB with something like a pin to remove anything that shouldn't be there.

Toner transfer works on blank side of PCB for component layouts as well. In fact I'm about to do a trial transfer onto an enclosure/soon-to-be Vibe Machine.

That's what I can say from my minimal experiences. Hope it helps ya.
Don't feel intimidated  :icon_biggrin:
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guidoilieff

the most important thing is how well you iron the photocopy to the copper and the tonner must be black as night. Dont iron too long or you'll screw it. Use some "paper jointing tape" to stick the photocopy from the other side of the copper board before ironing.

use a ceramic recipient for the acid and put the iron on top to heat it and you'll have the pcb ready in a few minutes.

FuzzFanatic71

I myself have thought about etching a board or two. Also I would love to etch some enclosures too. But I'm really clumsy at times and I've experienced chemical burns before, and I don't wish to experience them again. I'll leave it to the experts and just use prefabricated PCBs or stripboard. But yeah there is some great PCB layouts that I would love to build.
Why won't this @$&$ing thing work?

deadastronaut

Photocopiers are naff...

use a laser printer with toner saver off..

and use best quality setting....
https://www.youtube.com/user/100roberthenry
https://deadastronaut.wixsite.com/effects

chasm reverb/tremshifter/faze filter/abductor II delay/timestream reverb/dreamtime delay/skinwalker hi gain dist/black triangle OD/ nano drums/space patrol fuzz//

Mark Hammer

I've been making my own boards for over 35 years.  I've never used anything other than ferric chloride for etching, so I have no advice to offer about what is best/worst.

When I began, there were no laser printers, and the choices were between high-end (involving photo-sensitive boards, transparencies, and light-boxes) and low end (hand-applied resist patterns using pen, paint, or rub-on transfer).  I would photocopy a PCB mask, tape the photocopy over the copper surface, and use my spring-loaded center-punch to make dimples in the board where the pads should be.  Then I'd either draw or rub on circular pads on the dimples, and "connect the dots" when done, using either a pen, or a roll of 1/32 or 1/16 layout tape, that you could buy back then, cutting and bending the tape appropriately.  Radio Shack sold packages of rub-on transfers eventually, and those came in awful handy, especially for ICs.

Thank goodness for toner-transfer.  Although one does still have to repair a transfer with a pen on a regular basis.  There is always one little pad/trace somewhere that just didn't want to transfer over, or that you thought was fully transferred when it wasn't.

The two major areas you will need to concern yourself with are 1) surface preparation, and 2) transfer-detection.

1) Keep your stinking hands OFF the copper!  Seriously, "finger juice" can provide a sort of invisible resist pattern, superimposed on (underlying, actually) the intended pattern.  It doesn't fully resist the etchant, but produces a problematic stagger between the areas that etch at a proper rate, and those that take their bloody time.  To avoid that, you should have dry hands, or gloved hands, or simply manipulate the board in a manner that separates your fingers from the surface (I like the onion-skin paper that is found on the back of rub-on transfer sheets).  The board itself should be as close to gleaming as you can get it, using fine scrub pads or superfine steel wool.  If you can see your face in it, then it's ready.

2) Knowing when the transfer has transferred is something many take a long time to learn,  This is why I encourage people to make at least 3 copies of whatever pattern they wish to transfer.  Because chances are pretty good you're going to pooch the first 2 by misjudging whether it has transferred over.

Note that toner occupies physical space.  As such, it noticeably increases the thickness of a thin acetate sheet like PnP, but does not appreciably increase the thickness of something like photo-paper.  When applying a PnP transfer to a board, you will notice the acetate sagging around the toner pattern as you apply heat, such that the pattern is eventually sticking out in very slight relief.  Paper will not do that.  This does NOT mean that successful transfers cannot be accomplished with paper, either photo, or glossy magazine.  But what it does mean is that it will take more practice to have a good feel for when paper-based toner transfer has successfully copied over, than for judging whether PnP has done the same.  The one you can actually see, where the other you just have to acquire a feel for.


Ferric chloride works best, and most efficiently, when both warm and fresh, though you can still get many additional decent etches from the same batch.  "Warm" doesnot necessarily require the entire etchant bath be warm.  Realistically, the chemical etching process is a result of what's in contact with the board.  So what I do is float the board, copper side down, in the etchant, and warm the board.  You can use something like a little halogen-bulb goose-neck study lamp, or a hair-dryer or heat guy, or other source.  Heating the back of the board will result in some Brownian movement and as the used molecules of FeCl fall to the bottom of the container, fresh ones will move into place.

Speed of etch is reasonably important.  Remember that the etchant doesn't "know" to only etch vertically (i.e., from the surface down to the bare board).  If you leave it in too long, the etchant starts to eat at the sides of the traces, leaving a surface that can be difficult to solder to, or even have breaks/discontinuities.

Best advice is really to start with the simplest circuit you want to try out; something that isn't much larger than 1.5" x 1.5" or thereabouts.