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I'm wondering about the long term reliability of FFC connectors, especially in environments exposed to shock and vibration. It seems like everything with a display uses such connectors, which means they must be present and in use in automotive environments, at least in the user console, which is still exposed to shock, vibration and thermal cycling. One major concern is fretting. My Internet searching up to this point hasn't provided very much information.

Does anyone have any experience using these types of connectors in automotive / aerospace / military applications who can speak of the long term reliability? I think most people think of them as being flimsy, but from my experience they seem to make a very secure connection. Any feedback appreciated.

One thing I am aware of is that they are not meant for applications with multiple connect / disconnect cycles, but I'm speaking specifically about applications where the connectors will only be latched once, to connect boards together permanently inside a product enclosure.

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  • \$\begingroup\$ I can confirm that they're present in the automotive rearview mirrors that my employer produces, but, while I have no knowledge of any problems, I can't issue a confident statement on their reliability. \$\endgroup\$ – Kevin Vermeer Jul 30 '11 at 4:09
  • \$\begingroup\$ Also, do you intend to include flex circuits used as connectors in your FFC category? We use both, but some people differentiate. \$\endgroup\$ – Kevin Vermeer Jul 30 '11 at 4:10
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I designed a product line that used the FFC's and what I found is that long cables (about 12 inches) would tend to work loose in shipping. Basically, there was enough cable flopping in the breeze, with enough mass, that when the box was bumped around there was enough force/torque that it cable could come out of the connector. Fastening the cable down along it's length, so it couldn't flop around so much, helped a lot.

In the same product, we have a small LCD with a short (1 inch) FFC on it. We have never had an issue with this one.

This product line has since been redesigned to eliminate the FFC's (except for the LCD). The FFC's were an expensive mistake for us.

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  • \$\begingroup\$ In the internals of a few products I have seen using long FFCs, the FFC is taped to the board using double-sided tape immediately after exiting the connector. Did you look at similar simple mechanical reinforcement options? \$\endgroup\$ – Connor Wolf Jul 30 '11 at 8:19
  • \$\begingroup\$ @Fake Name Yes, eventually we used zip-ties (a.k.a. cable ties) to hold the cables in place. Double-sided tape wouldn't have worked for our application. The zip-ties helped, but we couldn't really tighten them down a lot because it would have mangled the cables. \$\endgroup\$ – user3624 Jul 30 '11 at 13:35
  • \$\begingroup\$ Thanks for the info. How wide were these cables? It seems like less wide = more secure FFC connections. \$\endgroup\$ – bt2 Jul 30 '11 at 19:21
  • \$\begingroup\$ @bt2 They were, i think, 0.5mm and 30 and 40 conductors. \$\endgroup\$ – user3624 Jul 30 '11 at 19:43
  • \$\begingroup\$ What kind of locking mechanism were you using on the connector? Are some better than others? \$\endgroup\$ – Peter Gibson Nov 19 '15 at 23:17
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I've used several JST FFC connectors for 0.5mm and 1mm pitch FFCs, and never had problems with them. Without actually measuring it it felt like pulling out the FFC required almost as much force as inserting. FFCs usually are light enough that they don't really exert a force on the connector.
Make sure the thickness of the FFC including the reinforcement matches the specified thickness for the connector.

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  • \$\begingroup\$ I found that the most "danger" is not pulling the cable straight out of the connector, but pulling them out somewhat crooked. This applies a kind of "lever action" on them that makes it easier to mess them up. Doing something that prevents them from going crooked helps. \$\endgroup\$ – user3624 Jul 30 '11 at 13:37
  • \$\begingroup\$ What kind of locking mechanism were you using on the connector? Are some better than others? \$\endgroup\$ – Peter Gibson Nov 19 '15 at 23:16

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