Abstract:
A sensor package (100) includes a manifold (102) and a MEMS die (104). The manifold (102) includes a cylindrical body (106), a flange (110), and a mounting surface (120). The cylindrical body (106) defines a first passage (112) that extends longitudinally along a central axis from a first exterior end (114) to an interior end (116) of the cylindrical body (106). The flange (110) extends from the cylindrical body (106) and has an outer periphery that is configured to support a print circuit board (126). The mounting surface (120) is disposed at the interior end (116) of the first passage (112). The surface area of the mounting surface (120) is less than the surface area of a MEMS die (104) configured to mate with the mounting surface (120).
Abstract:
A pressure sensor assembly is formed by: forming an inlet channel (108) by brazing a transition portion (114) to a pressure port (116) with a high temperature brazing processes, wherein the transition portion and the pressure port are both hollow tubular members and are formed of different materials, the pressure port including a base (202) and a projection (204) extending therefrom; after the inlet channel is formed, joining a header (122) and a sensor (104) to the pressure port with a soldering process that is at a lower temperature than the high temperature brazing process, wherein the header is joined to the base of the pressure port and the sensor is joined to the projection of the pressure port and is in fluid communication with a fluid to be measured through the pressure port; and welding a cover (120) to the header.
Abstract:
A differential pressure sensor may include a body with a first end, second end and wall wherein the first and second ends comprise isolator diaphragms connected to first and second process fluid inlets. A MEMS pressure sensor (32) including a pressure sensing diaphragm (D) with first and second sides may be mounted on a hollow pedestal (25) adhesively attached to an annular bottom (46) of a cylindrical cavity (44) wherein the first side of the sensor is coupled to the first isolator diaphragm (36) by a first fill fluid and the second side of the sensor is coupled to the second isolator diaphragm (38) through the interior of the hollow pedestal by a second fill fluid volume wherein the first and second fill fluid volumes are separated by an adhesive seal (48) between the bottom of the cylindrical cavity and the bottom of the hollow pedestal wherein the cylindrical cavity comprises a first cylindrical wall (51) with a first diameter in contact with the annular bottom, a frustroconical portion (52) in contact with the first cylindrical wall and in contact with a second cylindrical wall (54) with a second diameter larger than the first diameter such that the increased distance between the pedestal and the cylindrical wall prevents adhesive moving up the space between the pedestal and cavity wall from the bottom of the cavity when the pressure sensor and hollow pedestal are mounted in the cavity. The sensor further includes sensor elements (20) on the MEMS diaphragm that provide an indication of pressure differences between the first and second process fluids.
Abstract:
A pressure sensor includes a Wheatstone bridge circuit including a first resistor (R1), a second resistor (R2), a third resistor (R3), and a fourth resistor (R4) having matching output characteristics. The pressure sensor further includes a first trim resistor (RG, RS) in series with the Wheatstone bridge circuit, wherein the first trim resistor has output characteristics matching the output characteristics of the first resistor, the second resistor, the third resistor, and the fourth resistor of the Wheatstone bridge. The pressure sensor additionally includes a second trim resistor (RZ, RV) in parallel or a parallel loop with the Wheatstone bridge circuit, wherein the second trim resistor has output characteristics matching the output characteristics of the first resistor, the second resistor, the third resistor, and the fourth resistor of the Wheatstone bridge.
Abstract:
A pressure sensor includes a Wheatstone bridge circuit including a first resistor (R1), a second resistor (R2), a third resistor (R3), and a fourth resistor (R4) having matching output characteristics. The pressure sensor further includes a first trim resistor (RG, RS) in series with the Wheatstone bridge circuit, wherein the first trim resistor has output characteristics matching the output characteristics of the first resistor, the second resistor, the third resistor, and the fourth resistor of the Wheatstone bridge. The pressure sensor additionally includes a second trim resistor (RZ, RV) in parallel or a parallel loop with the Wheatstone bridge circuit, wherein the second trim resistor has output characteristics matching the output characteristics of the first resistor, the second resistor, the third resistor, and the fourth resistor of the Wheatstone bridge.
Abstract:
A sensor package (100) includes a manifold (102) and a MEMS die (104). The manifold (102) includes a cylindrical body (106), a flange (110), and a mounting surface (120). The cylindrical body (106) defines a first passage (112) that extends longitudinally along a central axis from a first exterior end (114) to an interior end (116) of the cylindrical body (106). The flange (110) extends from the cylindrical body (106) and has an outer periphery that is configured to support a print circuit board (126). The mounting surface (120) is disposed at the interior end (116) of the first passage (112). The surface area of the mounting surface (120) is less than the surface area of a MEMS die (104) configured to mate with the mounting surface (120).