WO2017077954A1 - Differential pressure detection element - Google Patents

Differential pressure detection element Download PDF

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Publication number
WO2017077954A1
WO2017077954A1 PCT/JP2016/082020 JP2016082020W WO2017077954A1 WO 2017077954 A1 WO2017077954 A1 WO 2017077954A1 JP 2016082020 W JP2016082020 W JP 2016082020W WO 2017077954 A1 WO2017077954 A1 WO 2017077954A1
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WIPO (PCT)
Prior art keywords
resistor
bridge circuit
differential pressure
pad
offset
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PCT/JP2016/082020
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French (fr)
Japanese (ja)
Inventor
達也 塩入
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株式会社フジクラ
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Publication of WO2017077954A1 publication Critical patent/WO2017077954A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/84—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by variation of applied mechanical force, e.g. of pressure

Definitions

  • the present invention relates to a differential pressure detecting element.
  • This application claims priority based on Japanese Patent Application No. 2015-216949 for which it applied to Japan on November 4, 2015, and uses the content here.
  • a configuration using a cantilever has been proposed as a pressure detection element (hereinafter referred to as a differential pressure detection element) for detecting pressure fluctuations.
  • a differential pressure detection element for detecting pressure fluctuations.
  • the cantilever part is elastically changed by the differential pressure.
  • the differential pressure is measured based on a change in the resistance value of a piezoresistor provided in the cantilever (see, for example, Patent Document 1).
  • the present invention has been made in view of the above-described problems, and an object thereof is to provide a differential pressure detecting element that can easily adjust an offset voltage generated in a displacement measuring unit.
  • a differential pressure detection element is formed of a movable part provided to be tiltable and a piezoresistor formed in at least a part of a deformation region of the movable part, and includes a first end and a second end.
  • An offset adjustment resistor having a first end connected to the first end of the bridge circuit, a second end connected to the second end of the bridge circuit, and the offset adjustment resistor
  • a first pad electrically connected to a first intersection of the first end of the bridge circuit and the first end of the bridge circuit; the second end of the offset adjustment resistor; and the second end of the bridge circuit.
  • a plurality of pads having at least a second pad electrically connected to a second intersection with the end, wherein the bridge circuit is closed by the offset adjustment resistor.
  • the movable portion is a cantilever
  • the bridge circuit is a Wheatstone bridge circuit
  • the offset adjustment resistor includes a plurality of resistors, the plurality of resistors are connected in series, and the plurality of the plurality of resistors are connected.
  • the pad may be configured such that each pad is connected to both ends of each of the plurality of resistors.
  • each of the plurality of resistors may have the same resistance value.
  • the offset voltage may be adjusted by connecting one of the plurality of pads to the ground.
  • the offset voltage may be adjusted by connecting two pads of the plurality of pads to the ground.
  • the offset voltage can be adjusted using any one of the pads connected to both ends of the offset adjustment resistor. Moreover, according to the said aspect of this invention, an offset voltage can be adjusted using either of the pads connected to the both ends of each of the some resistance with which an offset adjustment resistance is provided.
  • the offset voltage can be adjusted by connecting one of the pads connected to both ends of each of the plurality of resistors included in the offset adjustment resistor to the ground. It can be carried out. Thereby, the freedom degree of wiring can be raised and space saving can be achieved.
  • the offset voltage can be adjusted by connecting any two of the pads connected to both ends of each of the plurality of resistors included in the offset adjustment resistor to the ground. It can be carried out. Thereby, the offset voltage can be adjusted with higher accuracy.
  • FIG. 1 shows a configuration of a differential pressure detecting element 1 according to an embodiment of the present invention.
  • FIG. 2 shows the connection of the differential pressure detecting element 1 according to the present embodiment.
  • the differential pressure detection element 1 includes a movable part 10, a bridge circuit 20, an offset adjustment resistor 30, and a pad 40.
  • FIG. 1 is a bird's-eye view of the differential pressure detecting element 1.
  • the differential pressure detecting element 1 has a thin plate-like movable portion 10 at the center.
  • a bridge circuit 20 is formed on the support portion of the movable portion 10.
  • the movable part 10 is, for example, a cantilever 11 provided so as to be tiltable.
  • the shape of the cantilever 11 is, for example, a quadrangle, and all or a part of one side 12 is connected and fixed to and supported by the base body of the differential pressure detecting element 1.
  • a bridge circuit 20 is formed on one side 12 or the periphery of the cantilever 11.
  • FIG. 1 shows an example of a quadrangle in which one side of the cantilever 11 is fixed.
  • the shape of the cantilever 11 is not limited thereto, and may be a substantially circular shape, an elliptical shape, or a polygonal shape in which one side or a part thereof is fixed to the differential pressure detecting element.
  • the base body and the cantilever 11 may be integrally formed on substantially the same plane.
  • the differential pressure detecting element 1 is formed, for example, on the base 2 (see, for example, FIG. 3).
  • An example of the material of the base 2 is silicon.
  • the bridge circuit 20 is a piezoresistance (gauge resistance) formed by diffusion, ion implantation or the like on one side of the cantilever 11 fixed to the base 2 or on the base 2 around it. That is, the bridge circuit 20 is formed from a piezoresistor formed in at least a part of the deformation area of the cantilever 11.
  • the deformation area of the cantilever 11 includes all portions that can be deformed when the cantilever 11 tilts.
  • the bridge circuit 20 is provided, for example, at the root portion of the cantilever 11 where the distortion becomes the largest.
  • the bridge circuit 20 is, for example, a Wheatstone bridge circuit. Pad 41 to pad 43 are connected to bridge circuit 20 via wiring 60.
  • the bridge circuit 20 may be provided by forming a piezoresistive layer on the entire cantilever 11. Further, a protective film may be provided so as to cover the entire surface of the bridge circuit 20.
  • the protective film is preferably an insulating film, and is formed of, for example, silicon oxide or silicon nitride.
  • the bridge circuit 20 includes resistors 13 to 16 as shown in FIG.
  • One end of the resistor 13 is connected to one end of the resistor 14, and the other end of the resistor 13 is connected to one end of the resistor 15.
  • the other end of the resistor 14 is one end (first end) of the bridge circuit 20 and is connected to one end (first end) of the offset adjustment resistor 30.
  • One end of the resistor 16 is connected to the other end of the resistor 15.
  • the other end of the resistor 16 is the other end (second end) of the bridge circuit 20 and is connected to the other end (second end) of the offset adjustment resistor 30. That is, the first end of the bridge circuit 20 is electrically connected to the first end of the offset adjustment resistor 30, and the second end of the bridge circuit 20 is electrically connected to the second end of the offset adjustment resistor 30.
  • the offset adjustment resistor 30 includes six resistors 31 to 36 connected via a wiring 60.
  • the resistors 31 to 36 are formed on the silicon by diffusion, ion implantation, or the like, like the resistors 13 to 16 of the bridge circuit 20. In the following description, an example in which the number of resistors is six will be described, but the number of resistors may be one or more.
  • the resistance values of the resistors 31 to 36 are the same. As shown in FIGS. 1 and 2, one end of the resistor 31 is connected to one end (first end) of the bridge circuit 20, and the other end of the resistor 31 is connected to one end of the resistor 32 via a wiring 60. . The other end of the resistor 32 is connected to one end of the resistor 33 via the wiring 60.
  • the other end of the resistor 33 is connected to one end of the resistor 34 via the wiring 60.
  • the other end of the resistor 34 is connected to one end of the resistor 35 through the wiring 60.
  • the other end of the resistor 35 is connected to one end of the resistor 36 via the wiring 60.
  • the other end of the resistor 36 is connected to the other end (second end) of the bridge circuit 20 via the wiring 60. That is, the first end of the offset adjustment resistor 30 is electrically connected to the first end of the bridge circuit 20, and the second end of the offset adjustment resistor 30 is electrically connected to the second end of the bridge circuit 20.
  • pads 44 to 50 are connected to both ends of the resistors 31 to 36, respectively. That is, the pads 44 to 50 are configured such that the pads are connected to both ends of the resistors 31 to 36, respectively.
  • the pad 40 includes pads 41 to 50.
  • the pad 41 is connected to an intersection n1 (FIG. 2) between the resistor 13 and the resistor 15 of the bridge circuit 20 via a wiring 60.
  • a power source is connected to the pad 41.
  • the pad 42 is connected to an intersection n2 (FIG. 2) between the resistor 13 and the resistor 14 via a wiring 60.
  • the pad 42 is a positive output terminal.
  • the pad 43 is connected to an intersection n3 (FIG. 2) between the resistor 15 and the resistor 16 via a wiring 60.
  • the pad 43 is a negative output terminal.
  • the pad (first pad) 44 is connected to an intersection n4 (FIG. 2) between the other end of the resistor 14 of the bridge circuit 20 and one end of the resistor 31 of the offset adjustment resistor 30 via a wiring 60.
  • the pad 45 is connected to an intersection n5 (FIG. 2) between the other end of the resistor 31 and one end of the resistor 32 via a wiring 60.
  • the pad 46 is connected to an intersection n6 (FIG. 2) between the other end of the resistor 32 and one end of the resistor 33 via a wiring 60.
  • the pad 47 is connected to an intersection n7 (FIG. 2) between the other end of the resistor 33 and one end of the resistor 34 via a wiring 60.
  • the pad 48 is connected to an intersection n8 (FIG.
  • the pad 49 is connected to an intersection n9 (FIG. 2) between the other end of the resistor 35 and one end of the resistor 36 via a wiring 60.
  • the pad (second pad) 50 is connected to an intersection n10 (FIG. 2) between the other end of the resistor 36 and the other end of the resistor 16 of the bridge circuit 20 via a wiring 60. That is, two of the pads 44 to 50 are connected to both ends of any of the resistors 31 to 36, respectively. For example, a pad 44 and a pad 45 are connected to both ends of the resistor 31.
  • the pad (first pad) 44 is electrically connected to an intersection (first intersection) n4 between the first end of the offset adjustment resistor 30 and the first end of the bridge circuit 20, and the pad (second pad) (Pad) 50 is electrically connected to an intersection (second intersection) n10 between the second end of the offset adjustment resistor 30 and the second end of the bridge circuit 20.
  • the resistance values of the resistors 13 to 16 that are piezoresistors constituting the bridge circuit 20 are changed by the sag (deflection) of the cantilever 11.
  • the differential pressure detecting element 1 of the present embodiment takes out the change in resistance value as a voltage difference from the positive terminal (pad 42) and the negative terminal (pad 43). Further, as will be described later, by connecting at least one of the pads 44 to 50 to the ground, it is possible to adjust the offset voltage generated by the initial warp or the like generated in the bridge circuit 20.
  • the offset voltage is an output voltage when no pressure is applied to the cantilever 11.
  • FIG. 3 shows an example of wire connection when the offset voltage is not adjusted and wire connection when the offset voltage is adjusted in the present embodiment.
  • FIG. 4 shows the connection of the differential pressure detecting element 1 in a state where the offset voltage is not adjusted in the present embodiment.
  • the differential pressure detecting element 1 of the present embodiment includes a cantilever 11, a bridge circuit 20, an offset adjusting resistor 30, and a pad 40 formed on one substrate.
  • a cantilever 11 For example, MEMS (Micro Electro Mechanical) System) element.
  • the bridge circuit 20 is closed by offset adjusting resistors 30 connected to both ends thereof.
  • a power source is connected to the pad 41 via the wire w1, as shown in FIG. Furthermore, a positive output acquisition terminal of an external device (not shown) is connected to the pad 42 via a wire w2, and a negative output acquisition terminal of the external device is connected to the pad 43 via a wire w3. .
  • the pads 44 to 50 only the pad 47 is connected to the ground via the wire w5. That is, the pad 47 connected to the intersection n7 between the other end of the resistor 33 and one end of the resistor 34 via the wiring 60 is connected to the ground via the wire w5. Note that only when the offset voltage is not generated or when the offset voltage is equal to or lower than a predetermined value, only the pad 47 is connected to the ground.
  • the bridge circuit 20 is equivalent to a state in which the other end of the resistor 14 and the other end of the resistor 16 are directly connected and closed and connected to the ground.
  • the wires connected in FIG. 3 are w1, w2, w3, and w5.
  • FIG. 5 shows the connection of the differential pressure detecting element 1 according to the present embodiment in a state where the offset voltage is adjusted.
  • the offset voltage is generated on the negative voltage side due to the bending of the cantilever 11 due to the initial warp or the like, one of the pads 48 to 50 is connected to the ground via a wire according to the value of the offset voltage. .
  • the offset voltage is adjusted with respect to the differential pressure detecting element 1, only the pad 48 of the pads 44 to 50 is connected to the ground through the wire w4 as shown in FIG. . That is, the pad 48 connected to the intersection n8 between the other end of the resistor 34 and one end of the resistor 35 via the wiring 60 is connected to the ground via the wire w4.
  • the bridge circuit 20 is in a state where the resistor 33 and the resistor 34 are connected in series to the other end of the resistor 14.
  • the negative resistance 34 is decreased by one, and this resistance 34 is increased by one as the positive resistance.
  • the offset voltage is adjusted so that the offset voltage generated on the negative side approaches the 0V direction. Is called.
  • the wires connected in FIG. 3 are w1, w2, w3, and w4.
  • the offset voltage can be adjusted by connecting any one of the pads 44 to 50 to the ground via one wire. That is, according to the present embodiment, the offset can be adjusted by connecting one wire without performing a complicated process such as laser trimming.
  • the adjustment of the offset voltage may be performed by a manufacturing apparatus (not shown) of the differential pressure detecting element 1.
  • the manufacturing apparatus acquires the initial positive output and the negative output, calculates a resistance value such that the difference between the acquired positive output and the negative output is 0 V, and further, based on the calculated resistance value.
  • a pad connected to the ground may be selected.
  • the manufacturing apparatus may be configured to adjust the offset voltage by performing wire bonding from the selected pad to the ground.
  • the offset adjustment resistor 30 includes the six resistors 31 to 36 has been described, but the number of resistors is not limited thereto.
  • the number of resistors may be, for example, 1 to 7, 8 or more.
  • the example in which the six resistors 31 to 36 all have the same resistance value has been described, but the resistance value is not limited to this.
  • the resistance values of the resistor 31 and the resistor 36 are the same, the resistance values of the resistor 32 and the resistor 35 are the same, the resistances of the resistor 33 and the resistor 34 are the same, and the resistor 31 and the resistor 32.
  • the resistance values of the resistors 33 may be different from each other.
  • the cantilever 11 has been described as an example of the movable unit 10, but the movable unit 10 may be a diaphragm, for example.
  • the differential pressure detecting element 1 of the present embodiment includes the movable part 10 (for example, the cantilever 11), the bridge circuit 20, the offset adjusting resistor 30, and the pads (pad 40 to pad 50).
  • the movable part 10 is provided so as to be tiltable.
  • the bridge circuit 20 is a piezoresistor formed in the movable part 10 or its periphery (at least a part of the deformation area of the movable part 10).
  • the offset adjustment resistor 30 is connected to one end of the bridge circuit 20.
  • the pad is connected to both ends of the offset adjustment resistor 30.
  • the other end of the offset adjustment resistor 30 is connected to one end of the bridge circuit 20, and the bridge circuit 20 is closed by the offset adjustment resistor 30.
  • the offset voltage can be adjusted using any one of the pads 44 to 50 connected to both ends of the offset adjustment resistor 30.
  • the movable part 10 is a cantilever 11 and the bridge circuit 20 is a Wheatstone bridge circuit.
  • the offset adjusting resistor 30 includes a plurality of (for example, six) resistors (resistors 31 to 36), and the plurality of resistors are connected in series, and a pad (pad 44). ⁇ 50) are connected to both ends of each of the plurality of resistors.
  • the offset voltage is adjusted using any one of the pads 44 to 50 connected to both ends of the resistors 31 to 36 included in the offset adjustment resistor 30. It can be carried out.
  • the offset voltage is adjusted by connecting one of the pads (pad 44 to pad 50) to the ground.
  • one of the pads 44 to 50 connected to both ends of the resistors 31 to 36 of the offset adjustment resistor 30 is grounded via one wire. By connecting to the offset voltage, the offset voltage can be adjusted.
  • FIG. 6 shows a connection example of wires when the offset voltage is adjusted using two wires in the present embodiment.
  • FIG. 7 shows a connection example when the offset voltage is adjusted using two wires in the present embodiment.
  • the offset voltage is adjusted by connecting the two wires w11 and w12 to the ground.
  • the pad 45 is connected to the ground through the wire w11
  • the pad 48 is connected to the ground through the wire w12.
  • the two resistors 35 and 36 are connected on the negative side, and the positive side is connected. Is a state in which one resistor 31 is connected.
  • the offset voltage is adjusted so that the offset voltage generated on the positive side approaches the 0V direction. Is called.
  • the offset voltage is adjusted by connecting two pads of the pads (pads 44 to 50) to the ground.
  • the offset voltage can be adjusted with higher accuracy.
  • connection example between the differential pressure detecting element 1 and a signal processing IC Integrated Circuit
  • the signal processing IC acquires the positive output and the negative output output from the differential pressure detecting element 1, and calculates the displacement of the cantilever 11 using the acquired positive output and negative output. Then, the signal processing IC outputs information indicating the calculated displacement to an external device (not shown).
  • the external device is, for example, a display device, a PC (personal computer), a portable terminal, or the like.
  • FIG. 8 is a diagram illustrating a connection example between the differential pressure detecting element 1 and the signal processing IC 101 according to the present embodiment.
  • the example shown in FIG. 8 is an example in which the offset voltage is adjusted with a single wire.
  • the structure shown in FIG. 8 is comprised, for example on one board
  • the pad 41 to the wire w ⁇ b> 1, the pad 42 to the wire w ⁇ b> 2, and the pad 43 to the wire w ⁇ b> 3 of the differential pressure detecting element 1 are connected to the signal processing IC 101.
  • the power supply voltage is supplied from the signal processing IC 101 to the differential pressure detection element 1.
  • the power supply voltage is supplied to the differential pressure detection element 1 from another power supply circuit (not shown). You may make it do.
  • the ground pattern 111 and the pad 48 of the differential pressure detecting element 1 are connected via the wire w12, and the ground pattern 111 and the signal processing IC 101 are connected via the wire w101.
  • the wire w102 is connected to a power supply pattern (not shown), and the wire w103 is connected to an external device.
  • the degree of freedom of wiring increases.
  • the signal processing IC 101 adjusts the offset voltage using the positive output and the negative output, if the offset voltage is large, the adjustable range may be exceeded.
  • the offset voltage is adjusted by connecting one or two wires to the ground at the output of the differential pressure detecting element 1. Therefore, the amount of offset voltage adjustment performed by the signal processing IC 101 can be performed with a low voltage. As a result, according to the present embodiment, it is possible to prevent the offset range of the offset voltage from being removed by the signal processing IC 101.
  • the differential pressure detecting element 1 using the cantilever 11 for the movable part 10 is used in the following environment, for example.
  • CPAP Continuous Positive Airway Pressure
  • SAS sleep apnea syndrome
  • CPAP is a treatment method in which a certain pressure is applied to the airway by sending air from a mask attached to the nose.
  • This treatment method fluctuations in pressure due to respiration are acquired at any time, and air to be fed is controlled based on the acquired values.
  • a highly sensitive differential pressure detecting element differential pressure detecting element (differential pressure sensor) is required.
  • the differential pressure detecting element 1 using the cantilever 11 has high sensitivity and excellent response speed.
  • the differential pressure detecting element 1 of the present embodiment the offset voltage of the bridge circuit 20 can be easily and accurately adjusted by connecting one or two wires to the ground. Therefore, it is suitable as a differential pressure sensor used for CPAP treatment.
  • the differential pressure detecting element 1 of the present embodiment is also preferably used as a differential pressure sensor in detecting changes in the flow of air or liquid.
  • a manufacturing apparatus manufactures a plurality of differential pressure detecting elements 1 on a silicon wafer.
  • the manufacturing apparatus separates the differential pressure detecting elements 1 one by one.
  • the manufacturing apparatus attaches the differential pressure detecting element 1 on the package.
  • the manufacturing apparatus attaches the signal processing IC 101 near the differential pressure detecting element 1, for example.
  • the manufacturing apparatus bonds the differential pressure detecting element 1 and the signal processing IC 101 with a wire.
  • the manufacturing apparatus measures the offset voltage, selects one or two resistors from the offset adjustment resistors based on the measurement result, and selects a pad corresponding to the selected resistor.
  • the manufacturing apparatus bonds the selected pad to the ground using a wire.
  • the manufacturing apparatus packages as a component including the differential pressure detection element 1 and the signal processing IC 101.
  • the manufacturing apparatus calibrates the temperature of the packaged component.
  • the manufacturing apparatus may be packaged after performing the offset adjustment for only the differential pressure detecting element 1.
  • the manufacturing procedure mentioned above is an example, and is not restricted to this.
  • the bridge circuit 20 is a Wheatstone bridge circuit.
  • the bridge circuit 20 may be a circuit equivalent to the Wheatstone bridge circuit.
  • the bridge circuit 20 may use another bridge circuit such as a quarter bridge or a half bridge according to the measurement application.
  • the present invention is not limited to this. At least one of the offset adjustment resistor 30 and the pad 40 may be formed on a surface opposite to the silicon chip surface on which the cantilever 11 is formed.

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  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Power Engineering (AREA)
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  • Condensed Matter Physics & Semiconductors (AREA)
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  • Micromachines (AREA)

Abstract

This differential pressure detection element comprises: a movable unit provided in a tiltable manner; a bridge circuit having a first end and a second end and being formed from a piezoresistance formed in at least a part of a deformation region of the movable unit; an offset adjustment resistance having a first end connected to the first end of the bridge circuit and a second end connected to the second end of the bridge circuit; and a plurality of pads including at least a first pad electrically connected to a first point of intersection between the first end of the offset adjustment resistance and the first end of the bridge circuit and a second pad electrically connected to a second point of intersection between the second end of the offset adjustment resistance and the second end of the bridge circuit. The bridge circuit is closed by the offset adjustment resistance.

Description

差圧検出素子Differential pressure detector
　本発明は、差圧検出素子に関する。
　本願は、２０１５年１１月４日に日本に出願された特願２０１５－２１６９４９号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a differential pressure detecting element.
This application claims priority based on Japanese Patent Application No. 2015-216949 for which it applied to Japan on November 4, 2015, and uses the content here.
　圧力の変動を検出する圧力検出素子（以下、差圧検出素子という）として、カンチレバーを用いた構成が提案されている。このようなカンチレバーを用いた差圧検出素子は、差圧によってカンチレバー部が弾性変化する。差圧検出を行う装置では、このカンチレバーに設けられているピエゾ抵抗の抵抗値の変化に基づいて、差圧を計測する（例えば特許文献１参照）。 A configuration using a cantilever has been proposed as a pressure detection element (hereinafter referred to as a differential pressure detection element) for detecting pressure fluctuations. In the differential pressure detecting element using such a cantilever, the cantilever part is elastically changed by the differential pressure. In an apparatus for detecting a differential pressure, the differential pressure is measured based on a change in the resistance value of a piezoresistor provided in the cantilever (see, for example, Patent Document 1).
日本国特開２０１４－２３５０９５号公報Japanese Unexamined Patent Publication No. 2014-235095
　特許文献１に開示された技術において、例えばピエゾ抵抗部を不純物から保護する保護膜等をつけた場合、保護膜によって生じる膜張力によってカンチレバーにそり（「初期そり」ともいう）が発生する場合がある。しかしながら、特許文献１に開示された技術では、この初期そりが発生した場合、カンチレバーに設けられているピエゾ抵抗により形成されている変位測定部にオフセット電圧が発生するおそれがある。 In the technique disclosed in Patent Document 1, for example, when a protective film or the like that protects the piezoresistive portion from impurities is attached, warpage (also referred to as “initial warpage”) may occur in the cantilever due to film tension generated by the protective film. is there. However, in the technique disclosed in Patent Document 1, when this initial warpage occurs, there is a possibility that an offset voltage is generated in the displacement measuring unit formed by the piezoresistor provided in the cantilever.
　本発明は、上記の問題点に鑑みてなされたものであって、変位測定部に発生するオフセット電圧を簡便に調整することができる差圧検出素子を提供することを目的としている。 The present invention has been made in view of the above-described problems, and an object thereof is to provide a differential pressure detecting element that can easily adjust an offset voltage generated in a displacement measuring unit.
　本発明の一態様に係る差圧検出素子は、傾動可能に設けられた可動部と、前記可動部の変形域の少なくとも一部に形成されたピエゾ抵抗から形成され、第一端及び第二端を有するブリッジ回路と、前記ブリッジ回路の前記第一端に接続される第一端と、前記ブリッジ回路の前記第二端に接続される第二端とを有するオフセット調整抵抗と、前記オフセット調整抵抗の前記第一端と前記ブリッジ回路の前記第一端との第一の交点に電気的に接続される第一のパッドと、前記オフセット調整抵抗の前記第二端と前記ブリッジ回路の前記第二端との第二の交点に電気的に接続される第二のパッドとを少なくとも有する複数のパッドと、を備え、前記ブリッジ回路が前記オフセット調整抵抗によってクローズされている。 A differential pressure detection element according to an aspect of the present invention is formed of a movable part provided to be tiltable and a piezoresistor formed in at least a part of a deformation region of the movable part, and includes a first end and a second end. An offset adjustment resistor having a first end connected to the first end of the bridge circuit, a second end connected to the second end of the bridge circuit, and the offset adjustment resistor A first pad electrically connected to a first intersection of the first end of the bridge circuit and the first end of the bridge circuit; the second end of the offset adjustment resistor; and the second end of the bridge circuit. A plurality of pads having at least a second pad electrically connected to a second intersection with the end, wherein the bridge circuit is closed by the offset adjustment resistor.
　上記一態様において、前記可動部は、カンチレバーであり、前記ブリッジ回路は、ホイートストンブリッジ回路であり、前記オフセット調整抵抗は、複数の抵抗を備え、前記複数の抵抗が直列に接続され、前記複数のパッドは、前記複数の抵抗のそれぞれの両端に各パッドが接続されるように構成されていてもよい。 In the above aspect, the movable portion is a cantilever, the bridge circuit is a Wheatstone bridge circuit, the offset adjustment resistor includes a plurality of resistors, the plurality of resistors are connected in series, and the plurality of the plurality of resistors are connected. The pad may be configured such that each pad is connected to both ends of each of the plurality of resistors.
　上記一態様において、前記複数の抵抗それぞれの抵抗値が等しくてもよい。
　上記一態様において、前記複数のパッドのうち、１つのパッドがグランドに接続されることで、オフセット電圧の調整が行われてもよい。 In the above aspect, each of the plurality of resistors may have the same resistance value.
In the above aspect, the offset voltage may be adjusted by connecting one of the plurality of pads to the ground.
　上記一態様において、前記複数のパッドのうち、２つのパッドがグランドに接続されることで、オフセット電圧の調整が行われてもよい。 In the above aspect, the offset voltage may be adjusted by connecting two pads of the plurality of pads to the ground.
　本発明の上記態様によれば、オフセット調整抵抗の両端に接続されているパッドのうちのいずれかを用いて、オフセット電圧の調整を行うことができる。
　また、本発明の上記態様によれば、オフセット調整抵抗が備える複数の抵抗のそれぞれの両端に接続されているパッドのうちのいずれかを用いて、オフセット電圧の調整を行うことができる。 According to the above aspect of the present invention, the offset voltage can be adjusted using any one of the pads connected to both ends of the offset adjustment resistor.
Moreover, according to the said aspect of this invention, an offset voltage can be adjusted using either of the pads connected to the both ends of each of the some resistance with which an offset adjustment resistance is provided.
　また、本発明の上記態様によれば、オフセット調整抵抗が備える複数の抵抗のそれぞれの両端に接続されているパッドのうちのいずれかを１つをグランドに接続することで、オフセット電圧の調整を行うことができる。これにより、配線の自由度を高め省スペース化を図ることができる。
　また、本発明の上記態様によれば、オフセット調整抵抗が備える複数の抵抗のそれぞれの両端に接続されているパッドのうちのいずれかを２つをグランドに接続することで、オフセット電圧の調整を行うことができる。これにより、より精度の高いオフセット電圧の調整を行うことができる。 According to the above aspect of the present invention, the offset voltage can be adjusted by connecting one of the pads connected to both ends of each of the plurality of resistors included in the offset adjustment resistor to the ground. It can be carried out. Thereby, the freedom degree of wiring can be raised and space saving can be achieved.
According to the above aspect of the present invention, the offset voltage can be adjusted by connecting any two of the pads connected to both ends of each of the plurality of resistors included in the offset adjustment resistor to the ground. It can be carried out. Thereby, the offset voltage can be adjusted with higher accuracy.
本実施形態に係る差圧検出素子の構成を示す図である。It is a figure which shows the structure of the differential pressure | voltage detection element which concerns on this embodiment. 本実施形態に係る差圧検出素子の接続を示す図である。It is a figure which shows the connection of the differential pressure | voltage detection element which concerns on this embodiment. 本実施形態において、オフセット電圧の調整を行っていない場合のワイヤーの接続とオフセット電圧の調整を行った場合のワイヤーの接続の例を示す図である。In this embodiment, it is a figure which shows the example of the connection of the wire when the connection of the wire when adjustment of an offset voltage is not performed, and the adjustment of an offset voltage. 本実施形態において、オフセット電圧の調整を行っていない状態の差圧検出素子の接続を示す図である。In this embodiment, it is a figure which shows the connection of the differential pressure | voltage detection element of the state which is not adjusting the offset voltage. 本実施形態において、オフセット電圧の調整を行った状態の差圧検出素子の接続を示す図である。In this embodiment, it is a figure which shows the connection of the differential pressure | voltage detection element of the state which adjusted the offset voltage. 本実施形態において、２本のワイヤーを用いてオフセット電圧の調整を行う例におけるワイヤーの接続例を示す図である。In this embodiment, it is a figure which shows the example of a connection of the wire in the example which adjusts an offset voltage using two wires. 本実施形態において、２本のワイヤーを用いてオフセット電圧の調整を行う例における接続例を示す図である。In this embodiment, it is a figure which shows the example of a connection in the example which adjusts an offset voltage using two wires. 本実施形態に係る差圧検出素子と信号処理ＩＣとの接続例を示す図である。It is a figure which shows the example of a connection of the differential pressure | voltage detection element and signal processing IC which concern on this embodiment.
　図１は、本発明の一実施形態に係る差圧検出素子１の構成を示す。図２は、本実施形態に係る差圧検出素子１の接続を示す。
　図１に示すように、差圧検出素子１は、可動部１０、ブリッジ回路２０、オフセット調整抵抗３０、およびパッド４０を含んで構成されている。
　図１は、差圧検出素子１の鳥瞰図である。図１に示すように、差圧検出素子１は、中央に薄板状の可動部１０を有する。可動部１０の支持部にはブリッジ回路２０が形成されている。 FIG. 1 shows a configuration of a differential pressure detecting element 1 according to an embodiment of the present invention. FIG. 2 shows the connection of the differential pressure detecting element 1 according to the present embodiment.
As shown in FIG. 1, the differential pressure detection element 1 includes a movable part 10, a bridge circuit 20, an offset adjustment resistor 30, and a pad 40.
FIG. 1 is a bird's-eye view of the differential pressure detecting element 1. As shown in FIG. 1, the differential pressure detecting element 1 has a thin plate-like movable portion 10 at the center. A bridge circuit 20 is formed on the support portion of the movable portion 10.
　可動部１０は、傾動可能に設けられた例えばカンチレバー１１である。以下、本実施形態では、可動部１０がカンチレバー１１の例を説明する。カンチレバー１１の形状は、例えば四角形であり、一辺１２の全部もしくは一部が差圧検出素子１の基体に接続・固定され、支持されている。カンチレバー１１の一辺１２或いはその周辺に、ブリッジ回路２０が形成されている。なお、図１では、カンチレバー１１の一辺が固定されている四角形の例を示した。しかしながら、カンチレバー１１の形状はこれに限られず、一辺または一部が差圧検出素子に固定されている略円形、楕円形、多角形であってもよい。基体とカンチレバー１１とは、略同一平面上に一体に形成されていてもよい。 The movable part 10 is, for example, a cantilever 11 provided so as to be tiltable. Hereinafter, in the present embodiment, an example in which the movable unit 10 is the cantilever 11 will be described. The shape of the cantilever 11 is, for example, a quadrangle, and all or a part of one side 12 is connected and fixed to and supported by the base body of the differential pressure detecting element 1. A bridge circuit 20 is formed on one side 12 or the periphery of the cantilever 11. FIG. 1 shows an example of a quadrangle in which one side of the cantilever 11 is fixed. However, the shape of the cantilever 11 is not limited thereto, and may be a substantially circular shape, an elliptical shape, or a polygonal shape in which one side or a part thereof is fixed to the differential pressure detecting element. The base body and the cantilever 11 may be integrally formed on substantially the same plane.
　差圧検出素子１は、例えば基体２に形成される（例えば図３参照）。基体２の材料としては、シリコンが挙げられる。
　ブリッジ回路２０は、基体２に固定されているカンチレバー１１の一辺もしくはその周辺の基体２上に、拡散やイオン打ち込み等で形成されているピエゾ抵抗（ゲージ抵抗）である。つまり、ブリッジ回路２０は、カンチレバー１１の変形域の少なくとも一部に形成されたピエゾ抵抗から形成される。ここで、カンチレバー１１の変形域とは、カンチレバー１１が傾動した際に変形可能な全ての部分を含む。ブリッジ回路２０は、例えば、歪みが最も大きくなるカンチレバー１１の根本部分に設けられている。ブリッジ回路２０は、後述するように、例えばホイートストンブリッジ回路である。ブリッジ回路２０には、パッド４１～パッド４３が配線６０を介して接続されている。なお、ブリッジ回路２０は、カンチレバー１１の全体にピエゾ抵抗層を形成することで設けてもよい。また、ブリッジ回路２０の表面全体を覆うように、保護膜を設けてもよい。保護膜は、絶縁膜であることが好ましく、例えば酸化ケイ素、窒化ケイ素等から形成される。 The differential pressure detecting element 1 is formed, for example, on the base 2 (see, for example, FIG. 3). An example of the material of the base 2 is silicon.
The bridge circuit 20 is a piezoresistance (gauge resistance) formed by diffusion, ion implantation or the like on one side of the cantilever 11 fixed to the base 2 or on the base 2 around it. That is, the bridge circuit 20 is formed from a piezoresistor formed in at least a part of the deformation area of the cantilever 11. Here, the deformation area of the cantilever 11 includes all portions that can be deformed when the cantilever 11 tilts. The bridge circuit 20 is provided, for example, at the root portion of the cantilever 11 where the distortion becomes the largest. As will be described later, the bridge circuit 20 is, for example, a Wheatstone bridge circuit. Pad 41 to pad 43 are connected to bridge circuit 20 via wiring 60. The bridge circuit 20 may be provided by forming a piezoresistive layer on the entire cantilever 11. Further, a protective film may be provided so as to cover the entire surface of the bridge circuit 20. The protective film is preferably an insulating film, and is formed of, for example, silicon oxide or silicon nitride.
　また、ブリッジ回路２０は、図２に示すように抵抗１３～抵抗１６を備える。抵抗１３の一端は抵抗１４の一端に接続され、抵抗１３の他端は抵抗１５の一端に接続されている。抵抗１４の他端は、ブリッジ回路２０の一端（第一端）であり、オフセット調整抵抗３０の一端（第一端）に接続されている。抵抗１５の他端には、抵抗１６の一端が接続されている。抵抗１６の他端は、ブリッジ回路２０の他端（第二端）であり、オフセット調整抵抗３０の他端（第二端）に接続されている。つまり、ブリッジ回路２０の第一端はオフセット調整抵抗３０の第一端に電気的に接続され、ブリッジ回路２０の第二端はオフセット調整抵抗３０の第二端に電気的に接続されている。 Further, the bridge circuit 20 includes resistors 13 to 16 as shown in FIG. One end of the resistor 13 is connected to one end of the resistor 14, and the other end of the resistor 13 is connected to one end of the resistor 15. The other end of the resistor 14 is one end (first end) of the bridge circuit 20 and is connected to one end (first end) of the offset adjustment resistor 30. One end of the resistor 16 is connected to the other end of the resistor 15. The other end of the resistor 16 is the other end (second end) of the bridge circuit 20 and is connected to the other end (second end) of the offset adjustment resistor 30. That is, the first end of the bridge circuit 20 is electrically connected to the first end of the offset adjustment resistor 30, and the second end of the bridge circuit 20 is electrically connected to the second end of the offset adjustment resistor 30.
　オフセット調整抵抗３０は、配線６０を介して接続された６個の抵抗３１～抵抗３６を含んで構成されている。抵抗３１～抵抗３６はブリッジ回路２０の抵抗１３～抵抗１６と同様に、シリコン上に拡散やイオン打ち込み等で形成されている。なお、以下の説明では、抵抗の数が６個の例を説明するが、抵抗の数は１つ以上であればよい。また、抵抗３１～抵抗３６のそれぞれの抵抗値は、同じ値である。
　図１及び図２に示すように、抵抗３１の一端はブリッジ回路の２０の一端（第一端）に接続され、抵抗３１の他端は配線６０を介して抵抗３２の一端に接続されている。抵抗３２の他端は、配線６０を介して抵抗３３の一端に接続されている。抵抗３３の他端は、配線６０を介して抵抗３４の一端に接続されている。抵抗３４の他端は、配線６０を介して抵抗３５の一端に接続されている。抵抗３５の他端は、配線６０を介して抵抗３６の一端に接続されている。抵抗３６の他端は、配線６０を介してブリッジ回路２０の他端（第二端）に接続されている。つまり、オフセット調整抵抗３０の第一端はブリッジ回路２０の第一端に電気的に接続され、オフセット調整抵抗３０の第二端はブリッジ回路２０の第二端に電気的に接続されている。また、オフセット調整抵抗３０において、抵抗３１～抵抗３６それぞれの両端には、パッド４４～パッド５０が接続されている。つまり、パッド４４～パッド５０は、抵抗３１～抵抗３６のそれぞれの両端に各パッドが接続されるように構成されている。 The offset adjustment resistor 30 includes six resistors 31 to 36 connected via a wiring 60. The resistors 31 to 36 are formed on the silicon by diffusion, ion implantation, or the like, like the resistors 13 to 16 of the bridge circuit 20. In the following description, an example in which the number of resistors is six will be described, but the number of resistors may be one or more. The resistance values of the resistors 31 to 36 are the same.
As shown in FIGS. 1 and 2, one end of the resistor 31 is connected to one end (first end) of the bridge circuit 20, and the other end of the resistor 31 is connected to one end of the resistor 32 via a wiring 60. . The other end of the resistor 32 is connected to one end of the resistor 33 via the wiring 60. The other end of the resistor 33 is connected to one end of the resistor 34 via the wiring 60. The other end of the resistor 34 is connected to one end of the resistor 35 through the wiring 60. The other end of the resistor 35 is connected to one end of the resistor 36 via the wiring 60. The other end of the resistor 36 is connected to the other end (second end) of the bridge circuit 20 via the wiring 60. That is, the first end of the offset adjustment resistor 30 is electrically connected to the first end of the bridge circuit 20, and the second end of the offset adjustment resistor 30 is electrically connected to the second end of the bridge circuit 20. In the offset adjusting resistor 30, pads 44 to 50 are connected to both ends of the resistors 31 to 36, respectively. That is, the pads 44 to 50 are configured such that the pads are connected to both ends of the resistors 31 to 36, respectively.
　パッド４０は、パッド４１～パッド５０を備える。
　パッド４１は、ブリッジ回路２０の抵抗１３と抵抗１５との交点ｎ１（図２）に、配線６０を介して接続されている。パッド４１には、電源が接続される。パッド４２は、抵抗１３と抵抗１４との交点ｎ２（図２）に、配線６０を介して接続されている。パッド４２は、正出力の端子である。パッド４３は、抵抗１５と抵抗１６との交点ｎ３（図２）に、配線６０を介して接続されている。パッド４３は、負出力の端子である。 The pad 40 includes pads 41 to 50.
The pad 41 is connected to an intersection n1 (FIG. 2) between the resistor 13 and the resistor 15 of the bridge circuit 20 via a wiring 60. A power source is connected to the pad 41. The pad 42 is connected to an intersection n2 (FIG. 2) between the resistor 13 and the resistor 14 via a wiring 60. The pad 42 is a positive output terminal. The pad 43 is connected to an intersection n3 (FIG. 2) between the resistor 15 and the resistor 16 via a wiring 60. The pad 43 is a negative output terminal.
　パッド（第一のパッド）４４は、ブリッジ回路２０の抵抗１４の他端とオフセット調整抵抗３０の抵抗３１の一端との交点ｎ４（図２）に、配線６０を介して接続されている。パッド４５は、抵抗３１の他端と抵抗３２の一端との交点ｎ５（図２）に、配線６０を介して接続されている。パッド４６は、抵抗３２の他端と抵抗３３の一端との交点ｎ６（図２）に、配線６０を介して接続されている。パッド４７は、抵抗３３の他端と抵抗３４の一端との交点ｎ７（図２）に、配線６０を介して接続されている。パッド４８は、抵抗３４の他端と抵抗３５の一端との交点ｎ８（図２）に、配線６０を介して接続されている。パッド４９は、抵抗３５の他端と抵抗３６の一端との交点ｎ９（図２）に、配線６０を介して接続されている。パッド（第二のパッド）５０は、抵抗３６の他端とブリッジ回路２０の抵抗１６の他端との交点ｎ１０（図２）に、配線６０を介して接続されている。すなわち、抵抗３１～抵抗３６のいずれかの抵抗の両端には、パッド４４～パッド５０のうちの２つがそれぞれ接続されている。例えば、抵抗３１の両端には、パッド４４とパッド４５とが接続されている。さらに、パッド（第一のパッド）４４は、オフセット調整抵抗３０の第一端とブリッジ回路２０の第一端との交点（第一の交点）ｎ４に電気的に接続され、パッド（第二のパッド）５０は、オフセット調整抵抗３０の第二端とブリッジ回路２０の第二端との交点（第二の交点）ｎ１０に電気的に接続されている。 The pad (first pad) 44 is connected to an intersection n4 (FIG. 2) between the other end of the resistor 14 of the bridge circuit 20 and one end of the resistor 31 of the offset adjustment resistor 30 via a wiring 60. The pad 45 is connected to an intersection n5 (FIG. 2) between the other end of the resistor 31 and one end of the resistor 32 via a wiring 60. The pad 46 is connected to an intersection n6 (FIG. 2) between the other end of the resistor 32 and one end of the resistor 33 via a wiring 60. The pad 47 is connected to an intersection n7 (FIG. 2) between the other end of the resistor 33 and one end of the resistor 34 via a wiring 60. The pad 48 is connected to an intersection n8 (FIG. 2) between the other end of the resistor 34 and one end of the resistor 35 via a wiring 60. The pad 49 is connected to an intersection n9 (FIG. 2) between the other end of the resistor 35 and one end of the resistor 36 via a wiring 60. The pad (second pad) 50 is connected to an intersection n10 (FIG. 2) between the other end of the resistor 36 and the other end of the resistor 16 of the bridge circuit 20 via a wiring 60. That is, two of the pads 44 to 50 are connected to both ends of any of the resistors 31 to 36, respectively. For example, a pad 44 and a pad 45 are connected to both ends of the resistor 31. Further, the pad (first pad) 44 is electrically connected to an intersection (first intersection) n4 between the first end of the offset adjustment resistor 30 and the first end of the bridge circuit 20, and the pad (second pad) (Pad) 50 is electrically connected to an intersection (second intersection) n10 between the second end of the offset adjustment resistor 30 and the second end of the bridge circuit 20.
　本実施形態の差圧検出素子１においては、カンチレバー１１の橈み（たわみ）によって、ブリッジ回路２０を構成するピエゾ抵抗である抵抗１３～抵抗１６の抵抗値が変化する。本実施形態の差圧検出素子１は、この抵抗値の変化を電圧差として、正端子（パッド４２）と負端子（パッド４３）とから取り出す。
　また、後述するように、パッド４４～パッド５０のうちの少なくとも１つをグランドに接続することで、ブリッジ回路２０に発生する初期そり等によって発生するオフセット電圧の調整を行うことができる。ここで、オフセット電圧とは、カンチレバー１１に圧力が全く印加されていないときの出力電圧である。 In the differential pressure detecting element 1 of the present embodiment, the resistance values of the resistors 13 to 16 that are piezoresistors constituting the bridge circuit 20 are changed by the sag (deflection) of the cantilever 11. The differential pressure detecting element 1 of the present embodiment takes out the change in resistance value as a voltage difference from the positive terminal (pad 42) and the negative terminal (pad 43).
Further, as will be described later, by connecting at least one of the pads 44 to 50 to the ground, it is possible to adjust the offset voltage generated by the initial warp or the like generated in the bridge circuit 20. Here, the offset voltage is an output voltage when no pressure is applied to the cantilever 11.
＜オフセット電圧の調整＞
　次に、オフセット電圧の調整について説明する。
　図３は、本実施形態において、オフセット電圧の調整を行っていない場合のワイヤーの接続と、オフセット電圧の調整を行った場合のワイヤーの接続との例を示す。図４は、本実施形態において、オフセット電圧の調整を行っていない状態の差圧検出素子１の接続を示す。 <Adjustment of offset voltage>
Next, adjustment of the offset voltage will be described.
FIG. 3 shows an example of wire connection when the offset voltage is not adjusted and wire connection when the offset voltage is adjusted in the present embodiment. FIG. 4 shows the connection of the differential pressure detecting element 1 in a state where the offset voltage is not adjusted in the present embodiment.
　図３に示すように、本実施形態の差圧検出素子１は、カンチレバー１１、ブリッジ回路２０、オフセット調整抵抗３０、およびパッド４０が１つの基板上に形成されている、例えばＭＥＭＳ（Ｍｉｃｒｏ　Ｅｌｅｃｔｒｏ　Ｍｅｃｈａｎｉｃａｌ　Ｓｙｓｔｅｍｓ）素子である。そして、図１と図３に示すように、ブリッジ回路２０は、その両端に接続されたオフセット調整抵抗３０によってクローズされている。 As shown in FIG. 3, the differential pressure detecting element 1 of the present embodiment includes a cantilever 11, a bridge circuit 20, an offset adjusting resistor 30, and a pad 40 formed on one substrate. For example, MEMS (Micro Electro Mechanical) System) element. As shown in FIGS. 1 and 3, the bridge circuit 20 is closed by offset adjusting resistors 30 connected to both ends thereof.
　差圧検出素子１に対してオフセット電圧の調整が成されていない状態の場合、図３に示すように、パッド４１には、ワイヤーｗ１を介して電源が接続される。さらに、パッド４２には、ワイヤーｗ２を介して外部装置（不図示）の正出力の取得端子が接続され、パッド４３には、ワイヤーｗ３を介して外部装置の負出力の取得端子が接続される。また、パッド４４～パッド５０のうちパッド４７のみが、ワイヤーｗ５を介してグランドに接続される。すなわち、抵抗３３の他端と抵抗３４の一端との交点ｎ７に配線６０を介して接続されているパッド４７が、ワイヤーｗ５を介してグランドに接続される。なお、オフセット電圧が発生していない場合、またはオフセット電圧が所定の値以下の場合も、パッド４７のみがグランドに接続される。 In the state where the offset voltage is not adjusted with respect to the differential pressure detecting element 1, a power source is connected to the pad 41 via the wire w1, as shown in FIG. Furthermore, a positive output acquisition terminal of an external device (not shown) is connected to the pad 42 via a wire w2, and a negative output acquisition terminal of the external device is connected to the pad 43 via a wire w3. . Of the pads 44 to 50, only the pad 47 is connected to the ground via the wire w5. That is, the pad 47 connected to the intersection n7 between the other end of the resistor 33 and one end of the resistor 34 via the wiring 60 is connected to the ground via the wire w5. Note that only when the offset voltage is not generated or when the offset voltage is equal to or lower than a predetermined value, only the pad 47 is connected to the ground.
　この状態では、図４の鎖線ｅ１で囲んだ四角に示すように、抵抗３１～抵抗３６それぞれの抵抗値が同じであるため、抵抗３１と抵抗３６とが互いに打ち消し合う。同様に、抵抗３２と抵抗３５とが打ち消し合い、抵抗３３と抵抗３４とが打ち消し合う。このため、ブリッジ回路２０は、抵抗１４の他端と抵抗１６の他端とが直接接続されてクローズされて、グランドに接続されている状態と等価である。オフセット電圧の調整後の状態では、図３において接続されているワイヤーは、ｗ１、ｗ２、ｗ３、およびｗ５である。 In this state, as indicated by a square surrounded by a chain line e1 in FIG. 4, since the resistance values of the resistors 31 to 36 are the same, the resistors 31 and 36 cancel each other. Similarly, the resistor 32 and the resistor 35 cancel each other, and the resistor 33 and the resistor 34 cancel each other. For this reason, the bridge circuit 20 is equivalent to a state in which the other end of the resistor 14 and the other end of the resistor 16 are directly connected and closed and connected to the ground. In the state after adjustment of the offset voltage, the wires connected in FIG. 3 are w1, w2, w3, and w5.
　図５は、オフセット電圧の調整を行った状態の本実施形態に係る差圧検出素子１の接続を示す。
　カンチレバー１１の初期そり等による撓みによって、オフセット電圧が負の電圧側に発生している場合、オフセット電圧の値に応じてパッド４８～５０のうちの１つを、ワイヤーを介してグランドに接続する。
　差圧検出素子１に対してオフセット電圧の調整が成されている状態の場合、図３に示すように、パッド４４～パッド５０のうちパッド４８のみが、ワイヤーｗ４を介してグランドに接続される。すなわち、抵抗３４の他端と抵抗３５の一端との交点ｎ８に配線６０を介して接続されているパッド４８が、ワイヤーｗ４を介してグランドに接続される。 FIG. 5 shows the connection of the differential pressure detecting element 1 according to the present embodiment in a state where the offset voltage is adjusted.
When the offset voltage is generated on the negative voltage side due to the bending of the cantilever 11 due to the initial warp or the like, one of the pads 48 to 50 is connected to the ground via a wire according to the value of the offset voltage. .
When the offset voltage is adjusted with respect to the differential pressure detecting element 1, only the pad 48 of the pads 44 to 50 is connected to the ground through the wire w4 as shown in FIG. . That is, the pad 48 connected to the intersection n8 between the other end of the resistor 34 and one end of the resistor 35 via the wiring 60 is connected to the ground via the wire w4.
　この状態では、図５の鎖線ｅ２で囲んだ四角に示すように、抵抗３１と抵抗３６とが互いに打ち消し合い、抵抗３２と抵抗３５とが打ち消し合う。このため、ブリッジ回路２０は、抵抗１４の他端に抵抗３３と抵抗３４とが直列に接続されている状態である。この接続によって、負側の抵抗３４が１つ減少し、この抵抗３４が正側の抵抗として１つ増加することになる。この結果、正側と負側とでは、抵抗２個分の抵抗値の差が生じる。これによって、正出力端子と負出力端子との間では、正側が負側と比べて電圧が高くなるため、負側に発生していたオフセット電圧を０Ｖ方向へ近づけるようにオフセット電圧の調整が行われる。
オフセット電圧の調整後の状態では、図３において接続されているワイヤーは、ｗ１、ｗ２、ｗ３、およびｗ４である。 In this state, as indicated by a square surrounded by a chain line e2 in FIG. 5, the resistor 31 and the resistor 36 cancel each other, and the resistor 32 and the resistor 35 cancel each other. Therefore, the bridge circuit 20 is in a state where the resistor 33 and the resistor 34 are connected in series to the other end of the resistor 14. By this connection, the negative resistance 34 is decreased by one, and this resistance 34 is increased by one as the positive resistance. As a result, there is a difference in resistance value between two resistors on the positive side and the negative side. As a result, since the voltage on the positive side is higher than that on the negative side between the positive output terminal and the negative output terminal, the offset voltage is adjusted so that the offset voltage generated on the negative side approaches the 0V direction. Is called.
In the state after adjusting the offset voltage, the wires connected in FIG. 3 are w1, w2, w3, and w4.
　上述したように、本実施形態によれば、パッド４４～パッド５０のいずれかを、１本のワイヤーを介してグランドに接続することでオフセット電圧の調整を行うことができる。
　すなわち、本実施形態によれば、レーザートリミング等の複雑な工程を行うことなく、１つのワイヤーの接続によって、オフセットを調整することができる。 As described above, according to the present embodiment, the offset voltage can be adjusted by connecting any one of the pads 44 to 50 to the ground via one wire.
That is, according to the present embodiment, the offset can be adjusted by connecting one wire without performing a complicated process such as laser trimming.
　なお、オフセット電圧の調整は、差圧検出素子１の製造装置（不図示）によって行われるようにしてもよい。この場合、製造装置は、初期状態の正出力と負出力とを取得し、取得した正出力と負出力との差分が０Ｖになるような抵抗値を算出し、さらに算出した抵抗値に基づいてグランドに接続するパッドを選択するように構成されてもよい。そして、製造装置は、選択したパッドからグランドへワイヤーボンディングを行うことで、オフセット電圧の調整を行うように構成されてもよい。 Note that the adjustment of the offset voltage may be performed by a manufacturing apparatus (not shown) of the differential pressure detecting element 1. In this case, the manufacturing apparatus acquires the initial positive output and the negative output, calculates a resistance value such that the difference between the acquired positive output and the negative output is 0 V, and further, based on the calculated resistance value. A pad connected to the ground may be selected. The manufacturing apparatus may be configured to adjust the offset voltage by performing wire bonding from the selected pad to the ground.
　なお、図１～図５に示した例では、オフセット調整抵抗３０が、６個の抵抗３１～抵抗３６を備える例を説明したが、抵抗の数はこれに限られない。抵抗の数は、例えば、１個～７個、８個以上であってもよい。また、６個の抵抗３１～抵抗３６抵抗値が全て同じ例を説明したが、抵抗値はこれに限られない。例えば、抵抗３１と抵抗３６との抵抗値が同じであり、抵抗３２と抵抗３５との抵抗値が同じであり、抵抗３３と抵抗３４との抵抗とが同じであり、かつ抵抗３１、抵抗３２、及び抵抗３３それぞれの抵抗値が互いに異なっていてもよい。 In the example shown in FIGS. 1 to 5, the example in which the offset adjustment resistor 30 includes the six resistors 31 to 36 has been described, but the number of resistors is not limited thereto. The number of resistors may be, for example, 1 to 7, 8 or more. Further, the example in which the six resistors 31 to 36 all have the same resistance value has been described, but the resistance value is not limited to this. For example, the resistance values of the resistor 31 and the resistor 36 are the same, the resistance values of the resistor 32 and the resistor 35 are the same, the resistances of the resistor 33 and the resistor 34 are the same, and the resistor 31 and the resistor 32. The resistance values of the resistors 33 may be different from each other.
　また、本実施形態では、可動部１０の例としてカンチレバー１１を例に説明したが、可動部１０は、例えばダイヤフラム等であってもよい。 In the present embodiment, the cantilever 11 has been described as an example of the movable unit 10, but the movable unit 10 may be a diaphragm, for example.
　以上のように、本実施形態の差圧検出素子１は、可動部１０（例えばカンチレバー１１）と、ブリッジ回路２０と、オフセット調整抵抗３０と、パッド（パッド４０～パッド５０）と、を備える。可動部１０は、傾動可能に設けられている。ブリッジ回路２０は、可動部１０或いはその周辺（可動部１０の変形域の少なくとも一部）に形成されるピエゾ抵抗である。オフセット調整抵抗３０は、ブリッジ回路２０の一端に接続される。パッドは、オフセット調整抵抗３０の両端に接続される。本実施形態の差圧検出素子１において、オフセット調整抵抗３０の他端がブリッジ回路２０の一端に接続され、ブリッジ回路２０がオフセット調整抵抗３０によってクローズされている。 As described above, the differential pressure detecting element 1 of the present embodiment includes the movable part 10 (for example, the cantilever 11), the bridge circuit 20, the offset adjusting resistor 30, and the pads (pad 40 to pad 50). The movable part 10 is provided so as to be tiltable. The bridge circuit 20 is a piezoresistor formed in the movable part 10 or its periphery (at least a part of the deformation area of the movable part 10). The offset adjustment resistor 30 is connected to one end of the bridge circuit 20. The pad is connected to both ends of the offset adjustment resistor 30. In the differential pressure detecting element 1 of the present embodiment, the other end of the offset adjustment resistor 30 is connected to one end of the bridge circuit 20, and the bridge circuit 20 is closed by the offset adjustment resistor 30.
　この構成によって、本実施形態によれば、オフセット調整抵抗３０の両端に接続されているパッド４４～パッド５０のうちのいずれかを用いて、オフセット電圧の調整を行うことができる。 With this configuration, according to the present embodiment, the offset voltage can be adjusted using any one of the pads 44 to 50 connected to both ends of the offset adjustment resistor 30.
　また、本実施形態の差圧検出素子１においては、可動部１０は、カンチレバー１１であり、ブリッジ回路２０は、ホイートストンブリッジ回路である。また、本実施形態の差圧検出素子１において、オフセット調整抵抗３０は、複数（例えば６個）の抵抗（抵抗３１～抵抗３６）を備え、複数の抵抗が直列に接続され、パッド（パッド４４～５０）は、複数の抵抗それぞれの両端に接続されている。 Further, in the differential pressure detecting element 1 of the present embodiment, the movable part 10 is a cantilever 11 and the bridge circuit 20 is a Wheatstone bridge circuit. Further, in the differential pressure detecting element 1 of the present embodiment, the offset adjusting resistor 30 includes a plurality of (for example, six) resistors (resistors 31 to 36), and the plurality of resistors are connected in series, and a pad (pad 44). ˜50) are connected to both ends of each of the plurality of resistors.
　この構成によって、本実施形態によれば、オフセット調整抵抗３０が備える複数の抵抗３１～抵抗３６の両端に接続されているパッド４４～パッド５０のうちのいずれかを用いて、オフセット電圧の調整を行うことができる。 With this configuration, according to the present embodiment, the offset voltage is adjusted using any one of the pads 44 to 50 connected to both ends of the resistors 31 to 36 included in the offset adjustment resistor 30. It can be carried out.
　また、本実施形態の差圧検出素子１において、パッド（パッド４４～パッド５０）のうち、１つのパッドがグランドに接続されることで、オフセット電圧の調整が行われている。 In the differential pressure detecting element 1 of this embodiment, the offset voltage is adjusted by connecting one of the pads (pad 44 to pad 50) to the ground.
　この構成によって、本実施形態によれば、オフセット調整抵抗３０の抵抗３１～抵抗３６の両端に接続されているパッド４４～パッド５０のうちのいずれかを１つを１本のワイヤーを介してグランドに接続することで、オフセット電圧の調整を行うことができる。 With this configuration, according to the present embodiment, one of the pads 44 to 50 connected to both ends of the resistors 31 to 36 of the offset adjustment resistor 30 is grounded via one wire. By connecting to the offset voltage, the offset voltage can be adjusted.
＜２本のワイヤーを用いてオフセット電圧の調整を行う例＞
　次に、本実施形態において、２本のワイヤーを用いてオフセット電圧の調整を行う例を説明する。
　図６は、本実施形態において２本のワイヤーを用いてオフセット電圧の調整を行う場合のワイヤーの接続例を示す。図７は、本実施形態において２本のワイヤーを用いてオフセット電圧の調整を行う場合の接続例を示す。 <Example of offset voltage adjustment using two wires>
Next, in this embodiment, an example in which the offset voltage is adjusted using two wires will be described.
FIG. 6 shows a connection example of wires when the offset voltage is adjusted using two wires in the present embodiment. FIG. 7 shows a connection example when the offset voltage is adjusted using two wires in the present embodiment.
　図６に示す例では、２本のワイヤーｗ１１、ワイヤーｗ１２をグランドに接続することでオフセット電圧の調整を行う。
　図６に示すように、パッド４５がワイヤーｗ１１を介してグランドに接続され、パッド４８がワイヤーｗ１２を介してグランドに接続される。
　これにより、図７に示すように、２つのパッド４５及びパッド４８がグランドに接続されているため、負側には、２つの抵抗３５と抵抗３６とが接続された状態であり、正側には、１つの抵抗３１が接続されている状態である。この結果、正側と負側では、抵抗１個分の抵抗値の差が生じる。これによって、正出力端子と負出力端子との間では、負側が正側と比べて電圧が高くなるため、正側に発生していたオフセット電圧を０Ｖ方向へ近づけるようにオフセット電圧の調整が行われる。 In the example shown in FIG. 6, the offset voltage is adjusted by connecting the two wires w11 and w12 to the ground.
As shown in FIG. 6, the pad 45 is connected to the ground through the wire w11, and the pad 48 is connected to the ground through the wire w12.
Thus, as shown in FIG. 7, since the two pads 45 and 48 are connected to the ground, the two resistors 35 and 36 are connected on the negative side, and the positive side is connected. Is a state in which one resistor 31 is connected. As a result, there is a difference in resistance value for one resistor between the positive side and the negative side. As a result, since the voltage on the negative side is higher than that on the positive side between the positive output terminal and the negative output terminal, the offset voltage is adjusted so that the offset voltage generated on the positive side approaches the 0V direction. Is called.
　以上のように、本実施形態の差圧検出素子１は、パッド（パッド４４～５０）のうち、２つのパッドがグランドに接続されることで、オフセット電圧の調整が行われている。 As described above, in the differential pressure detecting element 1 of the present embodiment, the offset voltage is adjusted by connecting two pads of the pads (pads 44 to 50) to the ground.
　この構成によれば、図７に示したように、正側と負側との電圧差を抵抗１つ毎に調整することができるため、より精度良くオフセット電圧の調整を行うことができる。 According to this configuration, as shown in FIG. 7, since the voltage difference between the positive side and the negative side can be adjusted for each resistor, the offset voltage can be adjusted with higher accuracy.
＜信号処理ＩＣとの接続例＞
　ここで、差圧検出素子１と信号処理ＩＣ（Ｉｎｔｅｇｒａｔｅｄ　Ｃｉｒｃｕｉｔ；集積回路）との接続例を説明する。信号処理ＩＣは、差圧検出素子１が出力した正出力と負出力とを取得し、取得した正出力と負出力とを用いてカンチレバー１１の変位を算出する。そして、信号処理ＩＣは、算出した変位を示す情報を、外部装置（不図示）に出力する。外部装置は、例えば表示装置、ＰＣ（パーソナルコンピュータ）、携帯端末等である。 <Example of connection with signal processing IC>
Here, a connection example between the differential pressure detecting element 1 and a signal processing IC (Integrated Circuit) will be described. The signal processing IC acquires the positive output and the negative output output from the differential pressure detecting element 1, and calculates the displacement of the cantilever 11 using the acquired positive output and negative output. Then, the signal processing IC outputs information indicating the calculated displacement to an external device (not shown). The external device is, for example, a display device, a PC (personal computer), a portable terminal, or the like.
　図８は、本実施形態に係る差圧検出素子１と信号処理ＩＣ１０１との接続例を示す図である。なお、図８に示す例は、１本のワイヤーでオフセット電圧の調整を行った例である。また、図８に示す構成は、例えば１つの基板上に構成されている。
　図８に示すように、差圧検出素子１のパッド４１からワイヤーｗ１、パッド４２からワイヤーｗ２、およびパッド４３からワイヤーｗ３が信号処理ＩＣ１０１に接続される。なお、図８に示した例では、信号処理ＩＣ１０１から差圧検出素子１へ電源電圧を供給する例を示したが、他の電源回路（不図示）から差圧検出素子１へ電源電圧を供給するようにしてもよい。 FIG. 8 is a diagram illustrating a connection example between the differential pressure detecting element 1 and the signal processing IC 101 according to the present embodiment. The example shown in FIG. 8 is an example in which the offset voltage is adjusted with a single wire. Moreover, the structure shown in FIG. 8 is comprised, for example on one board | substrate.
As shown in FIG. 8, the pad 41 to the wire w <b> 1, the pad 42 to the wire w <b> 2, and the pad 43 to the wire w <b> 3 of the differential pressure detecting element 1 are connected to the signal processing IC 101. In the example shown in FIG. 8, the power supply voltage is supplied from the signal processing IC 101 to the differential pressure detection element 1. However, the power supply voltage is supplied to the differential pressure detection element 1 from another power supply circuit (not shown). You may make it do.
　グランドパターン１１１と差圧検出素子１のパッド４８とがワイヤーｗ１２を介して接続され、グランドパターン１１１と信号処理ＩＣ１０１とがワイヤーｗ１０１を介して接続される。
　信号処理ＩＣ１０１においては、ワイヤーｗ１０２が電源パターン（不図示）に接続され、ワイヤーｗ１０３が外部装置に接続される。
　図８に示したように、１本のワイヤーで接地を行うことでオフセット電圧の調整を行った場合、配線の自由度が高くなる。この結果、本実施形態によれば、差圧検出素子１および信号処理ＩＣ１０１を含む装置を省スペース化できる効果が得られる。 The ground pattern 111 and the pad 48 of the differential pressure detecting element 1 are connected via the wire w12, and the ground pattern 111 and the signal processing IC 101 are connected via the wire w101.
In the signal processing IC 101, the wire w102 is connected to a power supply pattern (not shown), and the wire w103 is connected to an external device.
As shown in FIG. 8, when the offset voltage is adjusted by grounding with a single wire, the degree of freedom of wiring increases. As a result, according to the present embodiment, it is possible to obtain an effect of saving the space of the apparatus including the differential pressure detecting element 1 and the signal processing IC 101.
　信号処理ＩＣ１０１が、正出力と負出力とを用いてオフセット電圧の調整を行う場合、オフセット電圧が大きいと調整できる範囲を超えてしまう場合があり得る。一方、本実施形態では、差圧検出素子１の出力において１本または２本のワイヤーをグランドに接続することでオフセット電圧が調整されている。そのため、信号処理ＩＣ１０１が行うオフセット電圧の調整量を低い電圧で行うことができる。この結果、本実施形態によれば、信号処理ＩＣ１０１によって、オフセット電圧の調整範囲が外れてしまうことを防ぐことができる。 When the signal processing IC 101 adjusts the offset voltage using the positive output and the negative output, if the offset voltage is large, the adjustable range may be exceeded. On the other hand, in the present embodiment, the offset voltage is adjusted by connecting one or two wires to the ground at the output of the differential pressure detecting element 1. Therefore, the amount of offset voltage adjustment performed by the signal processing IC 101 can be performed with a low voltage. As a result, according to the present embodiment, it is possible to prevent the offset range of the offset voltage from being removed by the signal processing IC 101.
　可動部１０にカンチレバー１１を用いた差圧検出素子１は、例えば以下のような環境で使用する。
　近年、睡眠時無呼吸症候群（ＳＡＳ；Ｓｌｅｅｐ　Ａｐｎｅａ　Ｓｙｎｄｒｏｍｅ）の治療法として、ＣＰＡＰ（Ｃｏｎｔｉｎｕｏｕｓ　Ｐｏｓｉｔｉｖｅ　Ａｉｒｗａｙ　Ｐｒｅｓｓｕｒｅ）と呼ばれる治療が注目されている。ＣＰＡＰとは、鼻に装着したマスクから空気を送りこむことによって、ある一定の圧力を気道にかける治療法である。この治療法では、呼吸による圧力の変動を随時取得して、取得した値に基づいて送り込む空気を制御している。この圧力の変動を精度良く検出するため、高感度な差圧検出素子（差圧センサ）が求められている。カンチレバー１１を用いた差圧検出素子１は、高感度であり応答速度にすぐれている。そのため、ＣＰＡＰにおける差圧の検出に最適である。そして、本実施形態の差圧検出素子１によれば、１本または２本のワイヤーをグランドに接続することで、ブリッジ回路２０のオフセット電圧を簡便に精度良く調整することができる。そのため、ＣＰＡＰの治療に用いる差圧センサとして好適である。
　同様に、空気や液体の流れの変動の検出においても本実施形態の差圧検出素子１は、差圧センサとして好適に用いられる。 The differential pressure detecting element 1 using the cantilever 11 for the movable part 10 is used in the following environment, for example.
In recent years, a treatment called CPAP (Continuous Positive Airway Pressure) has attracted attention as a treatment method for sleep apnea syndrome (SAS). CPAP is a treatment method in which a certain pressure is applied to the airway by sending air from a mask attached to the nose. In this treatment method, fluctuations in pressure due to respiration are acquired at any time, and air to be fed is controlled based on the acquired values. In order to accurately detect this pressure fluctuation, a highly sensitive differential pressure detecting element (differential pressure sensor) is required. The differential pressure detecting element 1 using the cantilever 11 has high sensitivity and excellent response speed. Therefore, it is optimal for detection of differential pressure in CPAP. According to the differential pressure detecting element 1 of the present embodiment, the offset voltage of the bridge circuit 20 can be easily and accurately adjusted by connecting one or two wires to the ground. Therefore, it is suitable as a differential pressure sensor used for CPAP treatment.
Similarly, the differential pressure detecting element 1 of the present embodiment is also preferably used as a differential pressure sensor in detecting changes in the flow of air or liquid.
　ここで、オフセット調整用のワイヤーボンディングを含めた差圧検出素子１の製造手順の概略を説明する。
　まず、製造装置（不図示）は、シリコンウェハ上に、複数の差圧検出素子１を製造する。次に、製造装置は、差圧検出素子１を１つずつ切り離す。次に、製造装置は、パッケージ上に差圧検出素子１を取り付ける。次に、製造装置は、図８に示したように、例えば、差圧検出素子１の近くに信号処理ＩＣ１０１を取り付ける。次に、製造装置は、差圧検出素子１と信号処理ＩＣ１０１とをワイヤーでボンディングする。次に、製造装置は、オフセット電圧を測定して、測定した結果に基づいてオフセット調整抵抗の中から１つまたは２つの抵抗を選択し、選択した抵抗に対応するパッドを選択する。次に、製造装置は、選択したパッドをグランドへワイヤーを用いてボンディングする。次に、製造装置は、差圧検出素子１、信号処理ＩＣ１０１を含む部品としてパッケージを行う。次に、製造装置は、パッケージした部品に対して温度に対するキャリブレーションを行う。なお、製造装置は、差圧検出素子１のみオフセット調整を行った後、パッケージするようにしてもよい。
　なお、上述した製造手順は一例であり、これに限られない。 Here, an outline of a manufacturing procedure of the differential pressure detecting element 1 including wire bonding for offset adjustment will be described.
First, a manufacturing apparatus (not shown) manufactures a plurality of differential pressure detecting elements 1 on a silicon wafer. Next, the manufacturing apparatus separates the differential pressure detecting elements 1 one by one. Next, the manufacturing apparatus attaches the differential pressure detecting element 1 on the package. Next, as shown in FIG. 8, the manufacturing apparatus attaches the signal processing IC 101 near the differential pressure detecting element 1, for example. Next, the manufacturing apparatus bonds the differential pressure detecting element 1 and the signal processing IC 101 with a wire. Next, the manufacturing apparatus measures the offset voltage, selects one or two resistors from the offset adjustment resistors based on the measurement result, and selects a pad corresponding to the selected resistor. Next, the manufacturing apparatus bonds the selected pad to the ground using a wire. Next, the manufacturing apparatus packages as a component including the differential pressure detection element 1 and the signal processing IC 101. Next, the manufacturing apparatus calibrates the temperature of the packaged component. The manufacturing apparatus may be packaged after performing the offset adjustment for only the differential pressure detecting element 1.
In addition, the manufacturing procedure mentioned above is an example, and is not restricted to this.
　なお、上述した例では、ブリッジ回路２０がホイートストンブリッジ回路である例を説明したが、ブリッジ回路２０は、ホイートストンブリッジ回路と等価な回路であってもよい。また、ブリッジ回路２０は、測定用途に応じて、クォータブリッジ、ハーフブリッジ等他のブリッジ回路を用いてもよい。 In the above example, the bridge circuit 20 is a Wheatstone bridge circuit. However, the bridge circuit 20 may be a circuit equivalent to the Wheatstone bridge circuit. The bridge circuit 20 may use another bridge circuit such as a quarter bridge or a half bridge according to the measurement application.
　また、図１等に示した構成では、カンチレバー１１の周辺に、オフセット調整抵抗３０及びパッド４０を配置した例を示したが、これに限られない。オフセット調整抵抗３０及びパッド４０のうちすくなくとも一方が、カンチレバー１１が形成されているシリコンチップ面と逆の面に形成されていてもよい。 In the configuration shown in FIG. 1 and the like, the example in which the offset adjusting resistor 30 and the pad 40 are arranged around the cantilever 11 is shown, but the present invention is not limited to this. At least one of the offset adjustment resistor 30 and the pad 40 may be formed on a surface opposite to the silicon chip surface on which the cantilever 11 is formed.
１…差圧検出素子、１０…可動部、１１…カンチレバー、１３～１６…抵抗、２０…ブリッジ回路、３０…オフセット調整抵抗、４０～５０…パッド、６０…配線、ｗ…ワイヤー DESCRIPTION OF SYMBOLS 1 ... Differential pressure detection element, 10 ... Movable part, 11 ... Cantilever, 13-16 ... Resistance, 20 ... Bridge circuit, 30 ... Offset adjustment resistance, 40-50 ... Pad, 60 ... Wiring, w ... Wire

Claims (5)

  1. 　傾動可能に設けられた可動部と、
    　前記可動部の変形域の少なくとも一部に形成されたピエゾ抵抗から形成され、第一端及び第二端を有するブリッジ回路と、
    　前記ブリッジ回路の前記第一端に接続される第一端と、前記ブリッジ回路の前記第二端に接続される第二端とを有するオフセット調整抵抗と、
    　前記オフセット調整抵抗の前記第一端と前記ブリッジ回路の前記第一端との第一の交点に電気的に接続される第一のパッドと、前記オフセット調整抵抗の前記第二端と前記ブリッジ回路の前記第二端との第二の交点に電気的に接続される第二のパッドとを少なくとも有する複数のパッドと、
    　を備え、
    　前記ブリッジ回路が前記オフセット調整抵抗によってクローズされている、差圧検出素子。     A movable part provided to be tiltable;
    A bridge circuit formed from a piezoresistor formed in at least a part of the deformation region of the movable part, and having a first end and a second end;
    An offset adjusting resistor having a first end connected to the first end of the bridge circuit and a second end connected to the second end of the bridge circuit;
    A first pad electrically connected to a first intersection of the first end of the offset adjustment resistor and the first end of the bridge circuit; the second end of the offset adjustment resistor; and the bridge circuit. A plurality of pads having at least a second pad electrically connected to a second intersection with the second end of
    With
    The differential pressure detecting element, wherein the bridge circuit is closed by the offset adjustment resistor.
  2. 　前記可動部は、カンチレバーであり、
    　前記ブリッジ回路は、ホイートストンブリッジ回路であり、
    　前記オフセット調整抵抗は、複数の抵抗を備え、
    　前記複数の抵抗が直列に接続され、
    　前記複数のパッドは、前記複数の抵抗のそれぞれの両端に各パッドが接続されるように構成されている、請求項１に記載の差圧検出素子。     The movable part is a cantilever,
    The bridge circuit is a Wheatstone bridge circuit;
    The offset adjustment resistor includes a plurality of resistors,
    The plurality of resistors are connected in series;
    The differential pressure detection element according to claim 1, wherein each of the plurality of pads is configured such that each pad is connected to both ends of each of the plurality of resistors.
  3. 　前記複数の抵抗のそれぞれの抵抗値が等しい、請求項２に記載の差圧検出素子。 The differential pressure detection element according to claim 2, wherein each of the plurality of resistors has an equal resistance value.
  4. 　前記複数のパッドのうち、１つのパッドがグランドに接続されることで、オフセット電圧の調整が行われている、請求項１から請求項３のいずれか１項に記載の差圧検出素子。 The differential pressure detection element according to any one of claims 1 to 3, wherein an offset voltage is adjusted by connecting one of the plurality of pads to the ground.
  5. 　前記複数のパッドのうち、２つのパッドがグランドに接続されることで、オフセット電圧の調整が行われている、請求項１から請求項３のいずれか１項に記載の差圧検出素子。 The differential pressure detection element according to any one of claims 1 to 3, wherein an offset voltage is adjusted by connecting two pads of the plurality of pads to a ground.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6219760U (en) * 1985-07-20 1987-02-05
JPH01244325A (en) * 1988-03-26 1989-09-28 Citizen Watch Co Ltd Pressure sensor unit
JP2014173988A (en) * 2013-03-08 2014-09-22 Seiko Instruments Inc Pressure sensor

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4333349A (en) * 1980-10-06 1982-06-08 Kulite Semiconductor Products, Inc. Binary balancing apparatus for semiconductor transducer structures

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6219760U (en) * 1985-07-20 1987-02-05
JPH01244325A (en) * 1988-03-26 1989-09-28 Citizen Watch Co Ltd Pressure sensor unit
JP2014173988A (en) * 2013-03-08 2014-09-22 Seiko Instruments Inc Pressure sensor

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