Source of FFC with single/both ends stripped - Page 1
Forum section: electronics / projects

author: miceuz
author_rank: Frequent Contributor
timestamp: October 26, 2016, 12:59:20 pm
content: I have never used FFC before, now I'm looking for a solution where one or both ends are soldered to the board. There are plenty of FFC cables at usual distributors, but none of them have cables with one or both ends stripped like in the attached picture of a cable I have desoldered from some floppy drive.Can anybody share sources for said cables?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 26, 2016, 02:03:02 pm
content: Unless you need a large qty then it's probably easiest to take a standard cable and strip it yourself - not too hard with a sharp knife and some practice.FFCs are manufactured as large sheets, so minimum order is fairly high for custom ones.

author: miceuz
author_rank: Frequent Contributor
timestamp: October 26, 2016, 04:18:53 pm
content: We need about 4000 pieces, so I guess it's a normal order. Is it considered custom cable? Could you suggest a company in Europe?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 26, 2016, 04:21:00 pm
content: Quote from: miceuz on October 26, 2016, 04:18:53 pmYes - that would be a normal sort of order qty for a custom FFC

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 26, 2016, 11:45:07 pm
content: DigiKey does custom cableshttp://www.digikey.ca/product-detail/en/te-connectivity-amp-connectors/A9AAT-0905F/A9AAT-0905F-ND/137559Of course pricing may vary, etc.

author: Daque
author_rank: Contributor
timestamp: June 22, 2017, 12:31:34 am
content: Any tips for stripping them? The ones at work seem to be impossible to strip with a knife you can cut thru to the copper but they wont pull off. Trying to filet them doesn't work either. We have resorted to burning them off with a hot soldering iron but they look awful after that.

author: Someone
author_rank: Super Contributor
timestamp: June 22, 2017, 01:18:05 am
content: Why flat flex? Traditionally this is done with flat ribbon cable, it comes delivered with a variety of connectors or stripped/tinned ends for direct soldering.

author: BrianHG
author_rank: Super Contributor
timestamp: June 22, 2017, 01:23:11 am
content: If you must use flex, I would just buy empty throughhole connectors & solder wires to the ends with heat shrink, most like flat ribbon cable. However, 4000, how are you going to wire all those? Is buying pre-fab cables to best solution?

author: jbb
author_rank: Super Contributor
timestamp: June 22, 2017, 08:34:35 am
content: At 4000 pieces you can design your own Flex PCB (aka FPC), no problem. They are made by PCB fabrication houses, and you can design then with PCB design software. (Unfortunately I'm not allowed to tell you who we use). They can be much more sophisticated than just some tracks. Unfortunately, the manufacturing isn't as standard so you will need to get in touch with board houses to discuss capabilities, design rules and how to prepare your Gerber files. You can't just send some Gerbers to a panel-sharing service and hope for the best.Quote from: miceuz on October 26, 2016, 04:18:53 pmI think thatWuerthmight be able to do flex PCB, but I've never used them for flex PCB. I suggest you consider a proper connector - they aren't very expensive and could make a big difference to your manufacturability. (Trust me, by the time your team has assembled 4000 pieces, and "she'll be right"s will be very verywrong.Do you know that you can solder components to an FPC (make sure it's specified to handle the temperature). Maybe you could just fit the components on the FPC itself and save a board in your design?However, there are another couple of tricks that might help your overall design. Firstly, you can get a thing called a rigid-flex PCB. This is a special composite PCB where part of it is rigid FR4, and another part is flexible. They cost more than a separate rigid PCB + separate flex PCB. An may have reliability issues due to different thermal coefficients between the rigid part and the flex part, leading to cracked traces and vias.Alternatively, you can work with stiffeners. Stiffeners are pieces of material added to the FPC to make parts of it rigid. You can ask the manufacturer to use a piece of FR4 as a stiffener, which will make nice flat places to attach stuff. (Note, this is not a rigid-flex PCB, because the FR4 is just a simple mechanical chunk with no vias through it).