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After delivery of my PCB, I realized that the spacing of PCB pads is not equal to the connector pitch (the PCB footprint is bigger than the OLED connector)! (sad)

Look:

PCB image

Any idea how to solve this problem?

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  • 5
    \$\begingroup\$ Your options are 1. use LOTS of really fine wire. 2. Have a new PCB made. \$\endgroup\$ – Connor Wolf Feb 22 '14 at 8:44
  • \$\begingroup\$ @ConnorWolf Sorry for speak here conner but I have a question. Can I have an E-mail or... for speak with you? I see your video clips on youtube. I would like to speak with you for tutorial request! \$\endgroup\$ – Roh Feb 22 '14 at 8:54
  • \$\begingroup\$ Make a small adapter pcb \$\endgroup\$ – alexan_e Feb 22 '14 at 8:55
  • \$\begingroup\$ @alexan_e What's your idea exactly? please more explain... is your idea the number two option of connor? \$\endgroup\$ – Roh Feb 22 '14 at 8:58
  • \$\begingroup\$ No, I mean just a small pcb to be used as a jumper between the different sized pads. Kind of like this one side for the lcd wire and the other side for the existing PCB. \$\endgroup\$ – alexan_e Feb 22 '14 at 9:02
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For a prototype, or to build 2 or 3 while you wait for the new PCBs to arrive, you can fix this, very carefully, with a scalpel.

Notice :

  1. A group of (say) 4 pads will align well enough to solder. You might get away with 6 or 8 but I suggest 4 to tolerate some misalignment. Or 5 for 6 groups of 5 each.
  2. You have a flexi-circuit connector.

Identify the 2 connectors in the middle, and run the scalpel between them, up to the / \ fanout section but stop before the really thin tracks from under the display. EDIT : Mark the groups with a pen before cutting!

Work outwards from there, making a set of 5-wide flexible connectors that will stand some misalignment.

As you get further out you will have to cut round the corners and most of the way along the angled sections, stopping before the root where the thin tracks are. enter image description here Now you will be bending the outer segments outwards a bit, which will move them upwards; I hope the PCB fingers are long enough so that they reach.

I would tack the outer end of each group in place before trying to solder them all properly.

If you DO cut a track you will have to scrape off some Kapton and resort to fine wire to repair it...

This is not guaranteed and may not work first time but I've seen good technicians make a splendid job of far worse...

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  • \$\begingroup\$ This was really the most interesting answer, Brian. Thank you for good idea. I will try it. \$\endgroup\$ – Roh Feb 22 '14 at 12:23
  • \$\begingroup\$ It's not a perfect solution because I assumed you are soldering the flex circuit to the PCB. Adapting a rigid connector to allow disconnection would be ... probably not practical. \$\endgroup\$ – Brian Drummond Feb 24 '14 at 17:10

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