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[on:]

hey there,

i've been thinking about making an electrical circuit on a piece of thick paper or carton,
this way, i can reduce costs of making some real small prototype systems (P < 0.8 Watt)

this way i can also make use of the flexebilty of the paper to bend it.

the tryed to come up with the materials plan, and thought about these things:
- Solder the wires all together (not so many, maybe 3 risistors some leds and a switch)
- put it on a piece of paper, and use glue to hold it togheter.

now im just left with a few mysteries:
a can i do this, will the paper be enough to isolate and not cause shorts?
b are there any examples out there, i cant seem to find any..
c will the paper burn just because an electrical current is flowing realy nearby?
d any tips before i actuly try this?

im not an expert at electronics, although i think i can make this work, still im not sure because i havent got lots of experience.
my budget is realy low, i cannot afford to buy some boards to solder my circuits on, so if there are other methods, leave them in a post.

sorry about my bad english, it isnt my home language.

thank already,
nick

[Reply #1 on:]

can i do this, will the paper be enough to isolate and not cause shorts?

You don't even need paper - there are plenty of examples out there of circuits built with just the parts and solder holding them together; nothing but air in-between. In fact, LED cubes are a prime example of this kind of construction - but there are examples out there done in this manner as an artistic effort.

That said, even a single sheet of typing paper would have enough insulation to allow two uninsulated wires on each side to cross and not cause issues (at least, conductivity issues).

are there any examples out there, i cant seem to find any..

You may not have been using the right search terms (seeing as english isn't your primary language?) - I just googled for "paper PCB" and found this link, entitled "Foldable Printed Circuit Boards on Paper Substrates":

http://gmwgroup.harvard.edu/pubs/pdf/1075.pdf

It's kinda interesting - a bit more technical than what you are probably looking for, but they show circuit traces and such applied to folded origami cranes...

Of course, the biggest problem when searching for something like "paper" and "PCB" together, is the sheer number of how-to articles dealing with -etching- a standard PCB using a laser printer and the toner transfer method (not at all what you are looking for).

Here's another interesting link:

http://popsci.typepad.com/how20blog/2007/10/ppcbs-aka-paper.html

will the paper burn just because an electrical current is flowing realy nearby?

It shouldn't be a problem as long as your circuit isn't pulling a lot of current; based on what you've specified as possible parts, it likely wouldn't be an issue.

any tips before i actuly try this?

Well - I would continue to do more research. For instance, did you know that there are standard PCBs out there made with paper as a base?

http://www.felsweb.com/lam_faq.htm#F

FR2 and FR3 use cotton paper as the base for the board; the difference between the two is that FR2 uses a phenolic binder, while FR3 uses an epoxy binder. If you continue to read down that page, you'll see a question reading "Can I make my own FR4?"...

In short - what you want to do isn't impossible; in fact, it is probably quite "doable". I would personally do it in something like this manner:

1. Print out my circuit on a printer on thick paper.
2. Use two-part clear epoxy to glue the paper to non-corrugated cardboard.
3. Use more epoxy to coat the front and back of the cardboard/paper sandwich.
4. Drill holes where the components will be inserted.
5. Insert the components - maybe some hot-glue dabs to keep them in place.
6. Wire/solder the parts together.

If you give it some more thought, you can probably come up with ways to put down "traces"; you can try copper foil tape (don't use aluminium foil, you can't solder to it) - there is also silver-bearing "wire glues" out there, as well as tapes and paints meant for repairing windshield defrosters (this stuff isn't cheap, though). You could just take solid copper wire, remove the insulating, then shape/flatten it with a hammer on an anvil and glue it down on the board.

Such boards should work fine - they won't look pretty, of course - but likely no worse than early electronics. In fact, you might want to read up on the history of electronics and such for more inspiration/ideas:

http://en.wikipedia.org/wiki/Printed_circuit_board

http://en.wikipedia.org/wiki/Point-to-point_construction

Good luck - hope this helps!

[Reply #2 on:]

I'm just a passerby who found your answer very informative. It made me think of stuff made like 3D cardboard sculptures used as components of a "plugin architecture" for simple circuits ("this piece for blinking, this piece for dimming, ..."). I bet I'll return to read your suggestions again.

Thanks for your time!

[Reply #3 on:]

Probably not the most stable unless parts are hot-glued in place or something.

[Reply #4 on:]

Sure, but on the other hand it may be fun to map particular functions to particular sections of a 3d cardboard animal you designed and cut yourself (I'm thinking of it as an add-on to educational toys designed with 3d software). But yes, robustness is an issue if you really want to make frequent changes.

[Reply #5 on:]

low-temperature hot does come off pretty readily could use that to hold the design in place for a few days while you try it out.