Geometric Design
Cross-sectional geometry defines the repeating ridges and grooves formed on a metallic or silicon diaphragm to control bending behavior. In pressure sensor design, a corrugation profile determines how the structure distributes mechanical stress when under load. It prevents the localized stress concentrations that occur in flat plates, allowing the diaphragm to undergo larger deflections without entering the plastic deformation regime.
Mechanical Compliance
Planar diaphragms undergo non-linear stiffening at deflections that exceed a fraction of their thickness, but the introduction of a concentric corrugation profile extends the linear operating region by several orders of magnitude. This pattern alters the structural response from a stretching-dominated mode to a bending-dominated mode. The resulting mechanical compliance remains highly predictable across the intended pressure range, reducing the need for complex electronic compensation in the signal conditioning circuitry.
Sensitivity Tradeoff
Sensor sensitivity increases when the diaphragm is made thinner or the groove depth is increased, but this change also lowers the natural frequency of the sensing element.
Manufacturing Tolerance
Variations in the forming or etching process can lead to slight deviations in the groove wall angle or depth, which shifts the nominal zero-point calibration of the transducer. This deviation is typically evaluated during final wafer-level testing or assembly inspection, where the pressure sensor is subjected to reference loads to verify that the deflection characteristics match the specified model. High-precision laser profiling is often employed to check that the shape remains within the limits set by the design specification before the component is integrated into the sensor housing.
