Bulk removal of copper from PCB - Double sided to single sided

I need to turn some double sided FR4 into single sided for making a capacitive sensor. The dimensions are 30cm by 7cm. Is there an easy way of removing large areas of copper without using large amounts of etchant?

In the past I've used a Dremel and a diamond burr but it takes about a minute per square cm and the surface finish isn't great.

Hi,

Keep some single sided PCB in stock, that's a waist removing one side to make a cap sensor.

Tom.... :)

Why do you need single sided for that?

In the past I made a capacitive sensor myself (the charge with 1M and time method) and found it worked way better when I used a double sided PCB with the back side connected to GND. For commercial sensors I have no idea though....

TomGeorge:
Keep some single sided PCB in stock, that’s a waist removing one side to make a cap sensor.

Locally large sheets of FR4 are only available with double sided copper. Joining several smaller sheets of single sided FR4 presents another series of mechanical problems.

Previous experience with buying FR4 from overseas has been that the quality is extremely variable and the shipping cost goes up disproportionally due to the size.

septillion:
Why do you need single sided for that?

In the past I made a capacitive sensor myself (the charge with 1M and time method) and found it worked way better when I used a double sided PCB with the back side connected to GND.

The geometry required for a capacitive sensor uses interleaved fingers or concentric rings. Adding a backplane just adds a capacitive offset. Perhaps in your case it improved the stability of the oscillator?

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