Capacitive sensor mfr. using monocrystal wafer - sawing through tri-layer arrangement of conductive plates and wafer which are bonded, glued, welded or soldered together

摘要

A monocrystalline Si, GaAs or quartz wafer (3) is insulated from two conductive plates (2,4) in a sandwich structure which is masked and etched to produce e.g. three sensors for separation by cutting in planes (6) coincident with, or parallel to, notches (15-17). The stray capacitance arises from the area of the bonding surfaces between the wafer (3) and plates (2,4). Single (15) and double (17) V-grooves, and wider troughs (16), are sawn to reduce risk of breakage. USE/ADVANTAGE - Prodn. of sensors for measurement of acceleration, slope or rotational speed. Has exactly defined stray capacitance connected in parallel with measuring capacitance. Requirements w.r.t. adjustment and precision of cutting are relaxed.