I have some PCB's that I have ordered from China. The PCB has a BGA component along with traces which go from the BGA component to another BGA IC(USB controller) and finally to USB. Right now I am very interested in 2 lines on a PCB. I think I can find the trace which is going but it is insulated. I dont want to cut the trace and bring out a wire and reattach the wire to the other part of a trace to probe the line on my Logic Analyzer. Is there any other chemical which will easily remove the insulation and expose the copper and help me probe the trace? What are the alternative I have?

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    \$\begingroup\$ Add probe points in your next design, especially when prototyping. \$\endgroup\$
    – Arsenal
    Nov 23, 2015 at 9:18
  • \$\begingroup\$ I am reverse engineering a working I2C interface. It isnt my PCB, and the register set isnt working for me correctly. I want to see the actualy I2C data which I am supposed to send \$\endgroup\$
    – red car
    Nov 23, 2015 at 9:23
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    \$\begingroup\$ Possible duplicate of How to remove solder mask? \$\endgroup\$
    – Arsenal
    Nov 23, 2015 at 9:30
  • \$\begingroup\$ Not really. Even if I remove the solder mask, how do I get the probe to clip correctly? I have to solder a wire which is tough given traces are so small \$\endgroup\$
    – red car
    Nov 23, 2015 at 9:36
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    \$\begingroup\$ Best chemical for the job is iron with 1% or so of carbon. Heat treat to harden and temper, and use abrasives to bring it to a sharp edge. Then you can scrape the insulation off and solder to the copper. \$\endgroup\$ Nov 23, 2015 at 10:58

1 Answer 1


Solder mask is some sort of thermoset polymer. Solvents for that sort of stuff are nasty. Look for a mechanical solution instead. Steel tools can scratch the mask off without damaging much the copper.


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