[qrp-l.org] Flex-circuits

[Dave Haupt]

Hi Matt,

Flex-circuits are double-sided PC boards, but the base material is polyimide (aka "Kapton") rather than glass-epoxy.  Most PC board fab houses can do flex circuits, although many won't do as fine a geometry, often requesting that you use no smaller than  10 mil wide trace and space.

I don't know where you'd get the material from; most of it comes from 3M, perhaps a Google search for "circuit laminates" would find it.  The generic term for the stuff is "Polyimide" and "3M Kapton" is just one brand of it.  Obviously, if you were going to make it yourself, you'd want to find it with some sort of copper cladding on it.  Holes tend to be punched, not drilled, and a standard plated-through process is often used.  8 and 10 mil are standard thicknesses for the base dielectric.

Flex-circuits have become extremely common as the interconnection technique of choice in automobile dashboards and also tail light assemblies, so the stuff has become a lot more common than it used to be.

Hope this gives you some directions to look.

73,

Dave W8NF

[qrp-l.org] OT: Flex-Circuit
Matt Palmer kd8dao at gmail.com

I once again plead to the gods of qrp to help me;

after spending a large amount of time thinking about radio designs I
was thinking I would like to do something modular ala ARC-164 or
ARC-231, both of these radios have "bread slice" modules tied together
with screws at the 4 cornors and are connected with a flex circuit at
the bottom, any ideas on how to go about designing a flex-circuit? I
found this FAB http://www.pcbfabrication.com/Flexible-PCB-Fabrication/Flexible-PCB-Fabrication.asp
would build them, I'm just not sure how to do the actual layout, if
even any special considerations are required.

Matt
KD8DAO