Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list  

Subject: Re: flexible pcb material?

From: "pork_u_pine2000" <wittend@...>
Date: 2007-08-08

I received some of the board material in question, and while it is
interesting it doesn't seem useful for anything I am building at the
moment.

Like you, my immediate thoughts are that it might be work for
mounting LEDs on a pre-stressed, curved surface, or the narrower
strips might serve for 'whiskers' on a robot of some sort.

But the stuff ∗is∗ really expensive, especially the narrow strips.

I have bought a good bit of 0.014 in double sided 1 oz copper FR4
board from 'abcfab' on eBay. The descriptions are a bit sketchy but
the product seems quite good and arrives reasonably quickly. I have
also purchased 0.030 in. and 0.060 in. board stock, as well as some
unlaminated 0.014 in. base material for experiments.

This source sells a variety of stock from 0.014 in. to 0.125 in. and
Cu copper weights up to 5 and 6 oz/in (sq).

I have also purchased unlaminated Kapton Polyimide in a variety of
thicknesses from 'PaperStreetPlastics'. I have been quite satisfied
by the quality and service from this source as well. I have used this
stuff for experimentation with flexible circuits using conductive
paints and/or inks. I've tried silver, cu, and carbon, so far.
Polyimide's's main claim to fame is that it is flexible and can
withstand solder temperatures.

The trick to developing good inks seems to be to design a mechanism
for applying the desired conductive material in a form that retains
flexibility, adhesion, and good conductivity. There are a lot of
issues that determine the final conductivity of the deposited material.

Though it is hardly an original thought, what I would really like to
be able to do is apply conductive, resistive, and suitable dialectric
materials using an inkjet process on a variety of appropriate
substrate materials. The goal would be to create all of the 'glue'
components - bypass caps, resistors, traces and pads to minimize the
fabrication cost and/or effort for one off prototypes.

--Dave

--- In Homebrew_PCBs@yahoogroups.com, Chris Hart <kc8ufv@...> wrote:
>
> For my uses, I have found the boards that are just a bunch of single
> hole solder pads are usless for my purposes, but I did find some very
> thin board material on ebay a while ago that is thin enough to fit
> through a standard inkjet printer, and I have successfully cut it with
> scisors. It is flexible, but I wouldn't count on flexing it under
parts,
> if you value your solder pads.
>
....