Question: Are there any specific design guidelines for housing CapSense circuitry?
Yes, the entire area above the CapSense sensor must not contain any conductive materials or air gaps. This includes any metal, paint with metallic flakes on the overlay, and air bubbles beneath the overlay. Also, thicker overlays will reduce the sensitivity of the sensor and make it difficult to detect a finger touch. There are no restrictions on the housing to the sides and below the CapSense circuit.