Air Gap between Capsense Sensor and an Overlay

Question: Can there be an air gap between a Capsense sensor and an Overlay?

 

Answer:

Capsense is not recommended to have any air gap between Capactitve Sensor PCB and an Overlay material.

If the requirement demands an air gap, you may connect a spring between the capsense button and the overlay, this should enable to detect it as a button with better sensitivity.

You may also refer an application note "
Using Springs as CapSense Sensors AN44999"

This application note considers the possibility of using springs as sensors. A comparison with solid conductive sensors and recommendations for the practical usage of springs are also discussed.