Patent ID: 6508129
Filing Date: 2003-01-21
Classification: G01L

Abstract:
A pressure sensor capsule with improved isolation, comprising:a pressure sensing body formed as a beam made of direct bonded layers of single crystal sapphire, the beam forming a beam wall around a central channel defined therein, the beam having a first end having a diaphragm adapted for fluid pressurization, and an opposite second end, the beam wall having an outer beam mounting surface between the ends; the central channel having a first width near the first end and having a second width, near the mounting surface, that is narrower than the first width; an isolation plate having a mounting hole therethrough and the beam mounting through the mounting hole; a braze joint sealingly joining the outer beam mounting surface to the mounting hole, sealingly isolating the second end from the fluid pressurization; and conductive film disposed in the central channel, including a pressure sensing film portion on the diaphragm, and a sensor lead portion extending from the pressure sensing portion, the beam having a notch at the second end, the notch forming an isolated lead surface on the central channel; and electrical contact pads disposed on the isolated lead surface.