Single axis accelerometer fabricated using printed circuit board techniques and laser ablation

Low-cost accelerometers could be used in applications where extremely good characteristics are not a requirement. This paper presents an accelerometer fabricated using printed circuit board (PCB) processing techniques, and laser ablation. Laser is used to remove part of the PCB substrate, releasing a mass suspended by copper beams. The structure is easily bonded to another PCB, creating a variable parallel-plate capacitor with a small gap, which capacitance varies with the movement of the mass, caused by external acceleration. The fabricated accelerometer has been compared to a commercial silicon one, showing good agreement in the measurements. The measured sensitivity was 81 fF/g.