Pressure-Sensitive Button Structure for Accurate Capacitance Sensing

The patent transitions from a traditional surface-mounted mechanical button to a pressure-sensitive button that utilizes the thickness dimension. By placing capacitive sensing elements on opposite surfaces of a thin substrate, the button functionality is achieved through pressure-induced capacitance changes rather than mechanical protrusion, thereby reducing the overall stacking thickness while maintaining press operation capability

The patent replaces the mechanical button structure with a pressure-sensitive capacitive sensing system. Instead of relying on mechanical contact and movement, the system uses changes in capacitance caused by pressure to detect user input, eliminating the need for thick mechanical components while preserving the essential press operation function

The patent introduces a substrate as an intermediary component between the first and second circuit boards. This substrate provides a standardized mounting platform with predefined spacing, allowing consistent separation distance between the capacitive sensing elements while simplifying the overall assembly process. The substrate acts as a mediator that ensures measurement accuracy without requiring complex adjustment mechanisms

The patent changes the structural parameter of the circuit board assembly by using a substrate with a specific, controlled thickness. This fixed thickness parameter ensures consistent spacing between the circuit boards, which is critical for accurate capacitance measurements. By controlling this geometric parameter at the substrate level, the system achieves measurement precision while maintaining manufacturing simplicity