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I'm designing a circuit with an OLED display, and I would prefer not to solder it directly to the board to be able to reuse it or change it as many times as needed.

The cheapest display model I could find at Mouser that fits my needs, has a 24-pin, 0.7 mm pitch FPC for which I can't seem to find the right connector. Do PCB connectors exist for this specific type of hot bar FPC interface or are they only supposed to be soldered onto a PCB? Is this ZIF-compatible? What PCB connector is compatible with this 24-pin, 0.7mm pitch FPC cable, or what should I look for when selecting one?

I'm only interested in standardised/commercial options, that I could easily find and purchase at a reasonable cost. I'd prefer not to add adapter boards or similar solutions. If that's the only type of option, I'd rather find a different display.

Here's a screenshot of the connector measurements (taken from the datasheet at the manufacturer's webpage):

Image of measurements taken from datasheet

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    \$\begingroup\$ To help get an answer, and to comply with the site rules for How to reference material written by others, please edit the question to include a link to the display datasheet. \$\endgroup\$ Commented Apr 12 at 9:24
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    \$\begingroup\$ Either a connector exists, or it does not exist if the intention is to solder, glue or whatever that flatflex to a PCB. However, asking if such a connector exists isn't really the question you want answered, so please change it to a question you want answered. \$\endgroup\$ Commented Apr 12 at 10:36
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    \$\begingroup\$ You may get somewhere with this: de.aliexpress.com/item/1005001962934620.html \$\endgroup\$ Commented Apr 12 at 12:16
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    \$\begingroup\$ It's 24 pins, not 23. Fencepost problem, wot. \$\endgroup\$ Commented Apr 12 at 14:40
  • \$\begingroup\$ I have soldered and resoldered these connectors with just a regular soldering iron. It's quite easy and the FPC can stand up to a few times of resoldering. \$\endgroup\$ Commented Apr 14 at 11:06

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Soldering is the only way this FPC is intended to be connected to a PCB.

Do PCB connectors really exist for this type of FPC interface?

No.

I don't want to solder it directly to the board.

Then hire someone else to do it for you.

If your wish is to have a removable connection, design an intermediate FPC with a 0.7 pitch on one end for permanent soldering to the display FPC and a 0.5 pitch for removable mating to an FFC socket on a PCB.

Or, buy a ready-made adapter board to an IDC connector (Thanks to 6v6gt)

Or, solder 24 discrete wires to the 24 fingers and terminate the other ends to a wire-to-board connector.

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  • \$\begingroup\$ > Do PCB connectors really exist: . . . Yes . . . . . . . . . \$\endgroup\$ Commented Apr 13 at 18:30
  • \$\begingroup\$ @TonyStewartEEsince1975 Where? How to find them? \$\endgroup\$ Commented Apr 13 at 19:51
  • \$\begingroup\$ did anyone read my update or is it hidden from -4 voters who didn't \$\endgroup\$ Commented Apr 13 at 21:35
  • \$\begingroup\$ @Carles Araguz "Where? How to find them?". No, Tony did not find them. The title of an AliExpress ad says 0.7 mm, but when you look at the specs, it's 0.5 or 1 mm. \$\endgroup\$ Commented Apr 13 at 22:12
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It's impossible to prove that such a connector does not exist, in fact it's a pretty fair bet that some kind of connector exists that would allow the manucturer to test the product (though it might be some custom fixture that costs a small fortune and has an array of pogo pins to contact the vias near the edge).

In the field of relatively inexpensive connectors designed for production, neither LCSC, Digikey or Mouser show a single connector with 0.7mm pitch so I think it is very unlikely such a part exists and is affordable/easy to source.

A typical display of this type has this note in the datasheet:

Recommended display connector: n/a (Hot-bar solder directly to PCB)

There are hand tools available in China and other places that allow this to be done in small quantities (however it probably takes some skill and consistency won't be as good as using a proper machine):

enter image description here

Pretty easy to make such an attachment for a temperature-controlled soldering iron if you have some scrap brass and rudimentary manual metalworking tools (mill with a slitting saw arbor, lathe).

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I would prefer not to solder it directly to the board to be able to reuse it or change it as many times as needed.

If you need to make a temporary connection during development, you can use Z-axis conductive tape, such as 3M 9703. It will work with the same pad layout you would use for a final product by soldering.

The Z-axis tape has tiny conductive particles embedded, which should make the contact between the pads and the FPC without shorting out the pads. The specified minimum pad clearance for 3M 9703 is 0.4 mm, while the pad layout in your image has about 0.3 mm of clearance. So it's a bit of a gamble whether it will work well enough.

The tape does not provide much mechanical support so it's only good enough for testing.

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  • \$\begingroup\$ If the pin spacing or pad area is too small, it probably won't work. Check out this cool blog writeup: https://tomverbeure.github.io/2019/11/21/Z-tape.html \$\endgroup\$ Commented Apr 15 at 0:51
  • \$\begingroup\$ @Rafael Thanks, that's useful information! Looks like the blog post has similar 0.3 mm clearance between pad, while somewhat smaller pad area. I have updated the answer. \$\endgroup\$ Commented Apr 15 at 5:12
  • \$\begingroup\$ This style of display is often sold alongside Arduino boards, glued with double sided tape to a carrier PCB that breaks out the SPI bus or I2C bus onto a 0.1" row of connectors. I use these, When I break the display or burn it out, I solder on a replacement via its flex strip using a flat soldering iron tip run along the edge, melting solder on pre-tinned pads. (running without a UV filter in front of it seems to accelerate screen burn - on a car dashboard even a Mylar sheet in front of it keeps it working for years, without a cover, it fails in months.) \$\endgroup\$ Commented Apr 15 at 9:56

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