SMOL: Questions Regarding FFC Cable / Mounting

SPARK-X
1

Hello,

I’m a massive fan of the new SMOL ZOE-M8Q boards!

It fills a niche that I’ve been needing for quite a while - a very small board that I can package into my own products, but easier to use than having to deal with than soldering GPS modules & dealing with antenna impedance calculations. Huge improvement for my use case over the arduino GPS breakouts with huge ceramic antennas & .1" headers.

Specific Questions Re FFC Cables:

  1. Is there a specification for minimum bend radii / acceptability of creasing the cable?

For example, this [ molex FFC cable datasheet [here explicitly allows for folding with a specified minimum bend radius. “The specimen shall be folded manually (Bending angle: 180° / Radius: 4mm)” “20 times MINIMUM”

  1. If there is no such bend spec, is the SMOL family drop-in compatible with some preexisting COTS FFC cable?

It seems like yall made your own on flex circuit., I imagine for space reasons, because the stiffener / exposed pads are quite small?

For example, [ this - I think its pads / stiffeners are longer, but it’s the same pitch & pin count at least?

Specific Question Regarding Mounting:

  1. Is there some recommended method for mechanically securing the SMOL boards? Beyond foam tape?

I’ve got a very very mechanically challenging application here (large shock loads), so we try to avoid foam tape inside the electrical enclosure whenever possible. If not, I’d resort to small 3d printed brackets.

Thanks a bunch. Glad to be using such a new product that all my questions haven’t already been covered on the forums by someone else for once.](0150200163 Molex | Cable Assemblies | DigiKey)](https://www.molex.com/pdm_docs/ps/PS-15166-001-001.pdf)](0151660185 Molex | Cable Assemblies | DigiKey)

2

Hi,

I’m not seeing any information about the bend radius for the FFCs on the manufacturer’s website… The spec is:

Polyimide Flex base material

FPC Thickness: 0.1 mm

Stiffener: Bottom Layer Polyimide 0.2 mm

Surface Finish: Immersion gold (ENIG) (1U")

Finished Copper: 1 oz Cu (35μm)

We deliberately kept the stiffeners short to avoid them colliding with or riding on the components further along each board.

The design brief for the smôl boards was to keep them as small as possible - and no wider than a AA battery. They are actually designed to be slid into a tube and then encapsulated. The width restriction ruled out mounting holes or lugs. For your application, a 3D-printed bracket sounds like the way to go.

Many thanks for the feedback,

Paul