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

----- Original Message -----
From: "Stefan Trethan" <stefan_trethan@...>
To: <homebrew_pcbs@yahoogroups.com>
Sent: Wednesday, July 16, 2003 3:02 PM
Subject: Re: [Homebrew_PCBs] flex circuits by hand?


> never did. never thought of.
>
> i wonder what use you might have for this?
> i think it would be damn hard to get components on it so they don't peel
> off the copper film when bent.
> and if only used stationary, at a certain amount of bending, i see no
> reason why not using thin fr4.
>
> please tell me what you want to use it for.
>
>
> regards
> stefan
>
> On Wed, 16 Jul 2003 11:03:39 -0500, Ron Amundson
<ron_amundson@...>
> wrote:
>
> > Has anyone ever tried to homebrew a flex circuit. It would seem to be a
> > similiar process except for finding copper coated kapton film. I wonder
> > if one could get prelaminated kapton, or if one has to do it themselves.
> > The copper bonding is probably a real pain due to the slipperiness of
> > kapton. I'd like to give it a try, but any pointers would be
appreciated.
> >
> > Thanks
> > Ron
> >
> > [Non-text portions of this message have been removed]
> >
> >
>
Why flex circuits:
Packaging issues and cost, they are pretty common in consumer goods, and
extremely common in the world of hard drives etc. One gets rid of a lot of
connections and can make the circuitry far smaller than would be possible
with a rigid board. As far as componenets and pcb fracturing, with the
commerical boards, its not a problem, but it may be a huge exercise in
frustration from a DIY standpoint, as I wonder if they do some type of
annealing of the copper prior to lamination to the kapton.

Thin FR4 does not lend itseof to the bend radius I need. You are correct
that one would not want the circuit to flex in the vicinty of components.
However the IO leads can flex as long as the component area is held
stationary.

I can get some proto's done for around $1500, and it seems worth trying to
homebrew it, as If I can acheive success in a couple days its worthwhile,
otherwise there goes my $1500...

Thanks
Ron