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What is the best way to break out a Flat Flexible Cable (FFC)? Specifically I've got a sensor which uses the 0.5mm pitch FFC that I would like to break out onto a breadboard. As you might already know these cables are extremely small and thin and soldering wires directly to them is almost impossible.

Note I DO NOT have access to the inside of the sensor so solder/connecting to the board directly is not an option.

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  • \$\begingroup\$ How thick is your FFC, and how many conductors does it have? \$\endgroup\$ – Kevin Vermeer Nov 9 '10 at 19:27
  • \$\begingroup\$ On a side note, I just finished tombstoning an 0402 resistor between the pad and pin of a 0.5mm pitch part that a few of my coworkers had just about given up on. Then I found that there were 8 more boards to do. Don't offer it as a solution if you're not willing to do it again! \$\endgroup\$ – Kevin Vermeer Nov 9 '10 at 20:11
  • \$\begingroup\$ it's an 8-conductor cable. Not sure the actual thickness. \$\endgroup\$ – jdiaz Nov 9 '10 at 20:16
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You can get free-hanging terminal blocks for FFC, but a quick check on Digikey revealed that these are only available for 1mm and larger pitches, which I imagine to be about the lower bound on the pitch of crimp housings for real wires. You might inquire with Tyco or Hirose about smaller pitches. If you can find these in 0.5mm pitch, this is the way to go for sure!

If you can't find a free-hanging terminal block, the best way to do this dependably, repeatably, and professionally is to build a breakout PCB. It doesn't need to be anything more than a connector and a couple of headers, but that will add some time and cost to your project. If you go to all that work, you might as well move the rest of your breadboard circuit to the PCB!

Connectors for FFC are almost always locking, so you should be able to buy a connector, put it on a protoboard/breakout board, and then solder to the connector pins. The pins will be small, but should be made of more durable stuff (Like solid brass or nickel, and likely gold plated) than the FFC.

Right-angle SMD FFC Connector

I've soldered to these (Mounted on a circuit board, but otherwise similar) before, and I'll warn you that you want to do it with a cable clamped into the connector for heatsinking and stabilization. Otherwise, when you heat the pins and the plastic softens, the slightest twitch will push the hot pin through the soft plastic, and you'll get solder bridges and mangled plastic all over the place. I moved misbehaving pins back into place with tweezers and superglued everything after I was done, but, it might be helpful to let some glue harden in the bottom of the housing before you start. I couldn't get at the bottom of mine because it was already on the PCB.

Finally, you can get crimp/solder terminals for free-hanging terminal blocks individually. They look like this:

crimp terminal for FFC

While you may have found it impossible to solder wires to the FFC, it's possible that a sturdier crimp terminal with a flat end will be easier to solder. Just make sure you crimp the wire in place first or heat sink your soldering job on the FFC when attaching the wire to make sure you don't mess that up after you get it working.

Whatever you end up doing, don't forget to the strain relief!

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  • \$\begingroup\$ I wish you had gone into greater detail. \$\endgroup\$ – Kortuk Nov 10 '10 at 17:06
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I know this is old but still relevant. Adadruit makes inexpensive FPC/FFC adapters found here: Adafruit Adapters enter image description here Also available on digikey under the same part numbers.

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If you can get the right surface mount connector, then you might be able to use a board like this:

http://uk.farnell.com/roth-elektronik/re900-02/adaptor-smd-0-5mm-28-48pin/dp/1426156

picture for link above

as a breakout.

If you were brave, you might even be able to reflow the flexy directly onto the 0.5mm pads, though personally I would use a connector.

There are a lot of Roth Elektronik boards of various kinds - there may be something else more suitable for you specific connector.

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  • \$\begingroup\$ I was able to find this at seeedstudios seeedstudio.com/depot/… but I wonder if I can still use the 8 pin ribbon without too much fuss? \$\endgroup\$ – jdiaz Nov 9 '10 at 20:36
  • \$\begingroup\$ Well, you could get a much smaller version of the same thing (anything with >= 8 pads at .5mm pitch). I suspect for 8 conductors you'd be able to put the flexy face down onto the PCB and then just reflow each tinned pad with an iron. Liquid flux might help, and I'd probably push the relevant bit of the flexy down with a screwdriver or similar as I went. \$\endgroup\$ – user1844 Nov 9 '10 at 21:59
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I'm using this.
You can order it cheaply from China (I used JLCPCB).
Reflowing the connector requires some practice, though...

enter image description here

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