Capacitive pressure transducer with thermal bonded flexible diaphragm

摘要

A circular diaphragm (11) with plane-parallel surfaces is sepd. by an annular metallic distance piece (20) from the baseplate (12). Both diaphragm (11) and baseplate (12) may be mfd. of ceramic, glass or monocrystalline material and thermally bonded to the spacer (20) by active solder including strongly reactive Ti,Zr,Be,Hf, or Ta.Alternatively the diaphragm (11) and baseplate (12) may be mfd. of oxide ceramic or sapphire and joined to a Cu spacer (20) by direct Cu bonding, forming an eutectic melt of Cu and Cu2O at 1065 deg.C. The facing surfaces of the diaphragm (11) and baseplate (12) carry circular metallic conductive electrodes (14,15) from which leads (16,17) are taken out through gastight seals