Author Topic: flex pcb rework : how to expose a track ?  (Read 1141 times)

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Offline jujunTopic starter

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flex pcb rework : how to expose a track ?
« on: November 21, 2019, 11:12:28 pm »
Hello,

Any clues on how to expose the copper of a track on a flex pcb (transparent orange ones) to be able to solder a wire on it ?
I tried several things but nothing works :(

Any advices ?

Thank you
 

Offline jbb

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Re: flex pcb rework : how to expose a track ?
« Reply #1 on: November 22, 2019, 12:03:43 am »
Sometimes I carefully scrape off the cover layer with a scalpel. I do this under a magnifier or microscope.

It’s not easy or pleasant, so I too would like some tips and tricks.

It helps to tape the FPC down to a flat surface (such as a spare blank PCB).
 

Offline KL27x

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Re: flex pcb rework : how to expose a track ?
« Reply #2 on: November 22, 2019, 03:53:42 am »
If you take a pointy Xacto blade and you grind the edge off until the point turns sideways, you will have a super narrow chisel.

An FPC has a very thin center layer between pours. So you don't want to push the blade into the board, like you might do on a regular PCB. So it's hard to make a clean opening in the coverlay. You might expose more copper than you like when the coverlay tears. And be super careful when you get to the copper. If you scrape all the way thru the copper on accident, you are probably already exposing copper of the other side, because the center layer is so thin. And then you can create shorts.
 

Offline all_repair

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Re: flex pcb rework : how to expose a track ?
« Reply #3 on: November 22, 2019, 04:44:32 am »
Fine sand paper, gently and carefully.
 


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