Author Topic: Custom PCB Boards?  (Read 1473 times)

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peteski

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Re: Custom PCB Boards?
« Reply #30 on: December 24, 2018, 10:38:32 PM »
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To  revisit the original question, this is the process I use to make simple one-of circuit boards which simplify wiring in DCC decoder installs.  It is really easy, simple, and not messy.  Been doing this for decades. No need for computers or lasers.



I just create some rough sketches of the circuit boards I'll be making, and I cut some blank PC board material to size.  Next, I clean the copper cladding really well using a regular household copper cleaning powder. Then, using an old-fashioned technical pen and some thinned Testors hobby paints, I paint the pads and traces over the cleaned bare copper cladding.  The paint will protect those areas from being dissolved by the etchant.  I chose a bottler of green paint because I had that paint handy at the time.



After the paint dries, I put the boards in the Ferric Chloride etchant.  I heat it up to about 40 deg. C to speed up the process.  Heating the etching solution is optional - it simply accelerates the  process, but etching at room temperature will also work.  I found that small laboratory hotplate at a local electronic  surplus store.  For small boards like these the amount of etchant needed is very small.  As shown, it is probably little over 1 fl. oz. It is actually more than needed. I could have used about half as much.

About 20 minutes later the boards are done. I like to float the boards being etched because that allows me  to see when the etching process is complete (the fiberglass/epoxy board is translucent).




Here are the blank boards after cleaning and removing the etch resist paint. 
Also shown  in the photo are the resistors, LEDs, and the decoder with the wires removed. These will all be soldered onto the boards.



Finally all  the components are soldered/glued on.

That's all it takes to make a small custom PC board.
--- Peteski de Snarkski
--- Honorary Resident Curmudgeon

mmagliaro

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Re: Custom PCB Boards?
« Reply #31 on: January 03, 2019, 11:08:59 PM »
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Back in the good old days, I used to just draw my circuit patters on copper-clad board with a Sharpie, dunk them in Ferric Chloride, and that was that.  I could make a board in an hour if it wasn't very complicated.  So for small onesy twosie jobs, or little boards that only have a few components,  I'd have to agree with Peteski and go that route.  You can make them for practically nothing. 

Recently, I did use a commercial place online  4pcb.com, and I used their "barebones" option (cheap).
https://www.4pcb.com/pcb-prototype-2-4-layer-boards-specials.html

Essentially, they take your artwork, which you must generate using THEIR application (download is free), and they make the boards.  The nice touches are that one side will have the wire pathways silk screened on, any component labeling you choose to include, and they do all the drilling.   So if you are making a board with 75 holes in it, that can be very handy.

The cost was $20/board, which, for a 3" x 5" board with about 75 holes, was worth it to me.  The boards are excellent.  The traces, holes, and printed text are neat as a pin.  Those are the boards I used to make that mini "throttle" I took to the RRMBC in BC last May (the one that I didn't take on the plane because it looked too much like a bomb... LOL!)

« Last Edit: January 04, 2019, 12:33:15 PM by mmagliaro »

David K. Smith

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Re: Custom PCB Boards?
« Reply #32 on: January 04, 2019, 04:55:42 AM »
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Back in the good old days, I used to just draw my circuit patters on copper-clad board with a Sharpie, dunk them in Ferric Chloride, and that was that.

Way too many moons ago, I once bought a Radio Shack DIY circuit board kit. The kit included a Sharpie to draw the pattern and a small chunk of steel wool to clean the copper.

Well, that's the last time I bought the kit. After that, I just bought bottles of ferric chloride.
"Life's a piece of sh!t when you look at it."
                                       —Monty Python

MK

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Re: Custom PCB Boards?
« Reply #33 on: January 04, 2019, 07:49:37 AM »
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Way too many moons ago, I once bought a Radio Shack DIY circuit board kit. The kit included a Sharpie to draw the pattern and a small chunk of steel wool to clean the copper.

Well, that's the last time I bought the kit. After that, I just bought bottles of ferric chloride.

The good ol' days!  I did the same thing.  I might still have some remnants of that kit lying around.

mmagliaro

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Re: Custom PCB Boards?
« Reply #34 on: January 04, 2019, 12:35:41 PM »
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Way too many moons ago, I once bought a Radio Shack DIY circuit board kit. The kit included a Sharpie to draw the pattern and a small chunk of steel wool to clean the copper.

Well, that's the last time I bought the kit. After that, I just bought bottles of ferric chloride.

Me too!  And I commandeered one of my mother's glass baking dishes to do my etching in.  Yep, this was around 1978.
And one of the boards I etched was a "High Capacity Throttle" from the Peter Thorne book, "Practical Electronic Projects for Model Railroaders", and that board is actually under my layout and is still my main throttle to this day.

peteski

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Re: Custom PCB Boards?
« Reply #35 on: January 04, 2019, 03:46:12 PM »
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After emigrating from Poland (where I did some etching with chemicals I got IIRC, from school), I also used one of those Radio Shack etchign kits.  I never had good luck using Sharpie as etch resist.  the coverage was not solid enough and allowed some etchant to penetrate through the ink and etch small pits in the copper which was supposed to remain unetched.
--- Peteski de Snarkski
--- Honorary Resident Curmudgeon

MK

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Re: Custom PCB Boards?
« Reply #36 on: January 04, 2019, 04:13:40 PM »
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After emigrating from Poland (where I did some etching with chemicals I got IIRC, from school), I also used one of those Radio Shack etchign kits.  I never had good luck using Sharpie as etch resist.  the coverage was not solid enough and allowed some etchant to penetrate through the ink and etch small pits in the copper which was supposed to remain unetched.

I think everyone experienced that when using a Sharpie.  I quickly switched to dry rub transfers of drafting lines.  They worked really well.

nickelplate759

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Re: Custom PCB Boards?
« Reply #37 on: January 04, 2019, 08:09:39 PM »
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So - I just need a few small boards (maybe 1cm square?) to hold LEDs and resistors for DCC installs.  Nothing I couldn't draw myself, but also not anything I want to invest a lot of money in.   What are some sources for single-layer blank PCB material in small quantities?
George

NKPH&TS #3628

I'm sorry Dave, I'm afraid I can't do that.

peteski

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Re: Custom PCB Boards?
« Reply #38 on: January 04, 2019, 08:38:17 PM »
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So - I just need a few small boards (maybe 1cm square?) to hold LEDs and resistors for DCC installs.  Nothing I couldn't draw myself, but also not anything I want to invest a lot of money in.   What are some sources for single-layer blank PCB material in small quantities?

What thickness?  Standard Fiberglass/epoxy copper clad is 1/16" thick. In most cases, way too thick for our application.  Back in the day I used to split 1?16" thick double-sided board into two 1/32" thick boards, but I don't have to do that anymore - there are many sources of thin single sided boards.

Over the years I have accumulated a good stash of various thickens PC boards (single- and double-sided) from electronic surplus dealers (like Electronic Goldmine, All Electronics, Jameco, and several others).  But they mostly carry double-sided material, so sometimes it takes a while to find the single-sided copper-clad.  "Copper-clad" is the name used for the raw unetched PC Board material.

I did a quick Google search for "single-sided copper-clad" There seem to be lots of sources out there (including Amazon and eBay).   Here is one:
https://www.circuitspecialists.com/printed-circuit-board-supplies-printed-circuit-boards
I recommend 1/32" or thinner for your type of application.
--- Peteski de Snarkski
--- Honorary Resident Curmudgeon

Steveruger45

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Re: Custom PCB Boards?
« Reply #39 on: January 05, 2019, 03:48:29 PM »
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Here is a vendor on eBay that has some good thickness selections going pretty thin too.  I have used the 0.5mm (0.020”) and it’s been pretty good.  BTW on the thinnest stuff I’ve found you can separate the copper cladding from the fiberboard underneath if you put too much heat in it with the iron.  https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F120802756087
Steve
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narrowminded

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Re: Custom PCB Boards?
« Reply #40 on: January 05, 2019, 07:01:49 PM »
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Here is a vendor on eBay that has some good thickness selections going pretty thin too.  I have used the 0.5mm (0.020”) and it’s been pretty good.  BTW on the thinnest stuff I’ve found you can separate the copper cladding from the fiberboard underneath if you put too much heat in it with the iron.  https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F120802756087

I have purchased from them in the not too distant past.  All was satisfactory.  I thought the price wasn't the greatest but for as little as the boards are the material cost per board is not worth discussing. :)

I have .007" and .020" single sided.  Then .008"- .009"- .010"-  double sided.  So far I've milled the boards I've made.
Mark G.

Lemosteam

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Re: Custom PCB Boards?
« Reply #41 on: January 08, 2019, 07:12:56 AM »
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This gives me an idea.

What if you 3D printed the boards, with holes, complex shapes, etc. and raised areas where the traces are required, and then laminated copper foil on that using epoxy.  Rub the copper into the depressions, paint the raised copper areas (dip painting on a pad?) and then etched the excess copper away?

Copper Foil:

https://www.onlinemetals.com/merchant.cfm?pid=13550&step=4&showunits=inches&id=129&top_cat=87

Also available in 1/2" wide tape with a conductive adhesive backing (according to the description), but I do not know if the adhesive will etch away:

https://www.onlinemetals.com/merchant.cfm?pid=20334&step=4&showunits=inches&id=1408&top_cat=87

MK

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Re: Custom PCB Boards?
« Reply #42 on: January 08, 2019, 08:15:19 AM »
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This gives me an idea.

What if you 3D printed the boards, with holes, complex shapes, etc. and raised areas where the traces are required, and then laminated copper foil on that using epoxy.  Rub the copper into the depressions, paint the raised copper areas (dip painting on a pad?) and then etched the excess copper away?

That is waaay more work than the conventional etching method available now to the hobbyist.  Plus I'm not sure how much heat the plastic substrate can stand from a hot soldering iron.  I know the solder is going on to the trace but a lot of heat is conducted on the back side.
« Last Edit: January 08, 2019, 08:18:56 AM by MK »

Lemosteam

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Re: Custom PCB Boards?
« Reply #43 on: January 08, 2019, 08:48:42 AM »
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Maybe for simple traces, yes, buy not for complex, potentially shaped or fitted boards, or for very small holes that cannot be milled by most PCB houses.

Have you ever put a 900 degree soldering iron to FUD or even the new resins from the Anycubic?  Suggest you try.  It DOES NOT MELT.  I have poured molten led into FUD as a form without failure.

Anyway, its just another idea to use.

peteski

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Re: Custom PCB Boards?
« Reply #44 on: January 08, 2019, 03:57:19 PM »
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Wow!  There sure is some out-of-the-box reinventing of a a PC board creation.  "Printed circuit board"  name still fits perfectly.  :)
In my early days of being an electronic technician I dealt with circuit boards which had conventional copper clad ground and Vcc planes in the middle, then instead of traces they had many overlapping layers of what looked like a type of insulated magnet wire. they were all machine-routed (weaved?) parallel to either edge of the board with sharp 90 degree changes of direction.  All those wires were then sealed with some sort of conformal coating which encapsulated them, but they were still visible.  Those boards looked more like works of art than a circuit board.

And I think that in most cases the need is for very simple boards just to use as interconnects or as holders for resistors or LEDs.  3D-printing and wire weaving; would be way over-complicated.

Etching the copper cladding, or cutting grooves in it makes much more sense.



« Last Edit: January 08, 2019, 04:01:18 PM by peteski »
--- Peteski de Snarkski
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