Acceleration Sensor Beam Stress Concentration

The patent applies local quality by creating a non-uniform beam structure with varying thickness along the beam length. The beam is thicker near the weight attachment point and tapers toward the support, concentrating stress locally at specific regions where piezoresistive elements are placed. This localized stress concentration enables high sensitivity detection while maintaining the ability to detect larger acceleration ranges.

The patent changes the geometric parameters of the beam by introducing a thickness gradient from the weight attachment point to the support. This parameter variation allows the beam to simultaneously achieve wide detection range and high sensitivity by optimizing the stress distribution characteristics through controlled geometric modification.

The patent uses copying by creating a three-dimensional beam structure with varying thickness that can be manufactured using standard semiconductor fabrication processes. Instead of requiring complex oblique surface machining, the design replicates the necessary stress concentration geometry through controlled thickness variation during fabrication, achieving the same detection sensitivity with simpler, more stable manufacturing processes.

The patent replaces mechanical surface preparation (creating oblique surfaces through machining or grinding) with a fabrication-based approach where the beam thickness is controlled during the semiconductor manufacturing process. This substitution eliminates the need for sophisticated post-processing techniques and achieves the same functional result with simpler, more scalable manufacturing.