I have a silicon chip which has a built in capacitor pair. I use a Side-Brazed Dual In-Line Ceramic Package(shown below) to carry the chip. Wire bonding is used to connect the chip and package.

http://www.spectrum-semi.com/CSB02810.pdf is the link to the package.
I connect the package to an external board to measure the differential capacitance of the capacitor pair on the silicon chip. However, the output voltage of the external board drift seriously.
The external board works by applying a square wave to the capacitor pair. I found that the pads or pins next to the ones which I apply the square wave to also have certain alternating voltage(as large as 0.5V), which I suppose should be zero volt ideally.
I wonder is this induced alternating voltage the reason I got drifting capacitance measurement result?And how to solve it.

http://www.spectrum-semi.com/CSB02810.pdf is the link to the package.
I connect the package to an external board to measure the differential capacitance of the capacitor pair on the silicon chip. However, the output voltage of the external board drift seriously.
The external board works by applying a square wave to the capacitor pair. I found that the pads or pins next to the ones which I apply the square wave to also have certain alternating voltage(as large as 0.5V), which I suppose should be zero volt ideally.
I wonder is this induced alternating voltage the reason I got drifting capacitance measurement result?And how to solve it.