| 摘要 |
PURPOSE:To obtain the pressure sensor of high mechanical strength and accurate formation of air gaps by a method wherein an Si substrate is bonded to the thick part of an Si diaphragm with a glass having a close coefficient of thermal expansion, and a BSG having a through-hole electrode is bonded to the opposite surface of the substrate. CONSTITUTION:The diaphragm 1 is formed by etching the (100) plane of an Si wafer and hermetically bonded to the Si substrate 9 with a glass 10 having a coefficient of thermal expansion close to that of Si. The BSG2 thinner than the diaphragm is provided with the Cr-Au-SiO2 through-hole electrode 4, and the BSG plate 2 is fixed 8 to the other surface of the diaphragm 1 by electrostatic junction. A metallic tube 7 made of kovar or the like which has a small coefficient of thermal expansion is bonded to the hole of the substrate 9 with a glass 6 of low melting point and small coefficient of thermal expansion. The hermetic property and the mechanical strength of the sensor part are improved by bonding to the substrate by thus utilizing hermetic bonding with glass, and the air gap is accurately determined with good reproducibility by utilizing that strain accompanying electrostatic junction is very small. Accordingly, the titled device of high quality can be obtained. |
