JPH0257933A - Pressure sensor - Google Patents
Pressure sensorInfo
- Publication number
- JPH0257933A JPH0257933A JP20989888A JP20989888A JPH0257933A JP H0257933 A JPH0257933 A JP H0257933A JP 20989888 A JP20989888 A JP 20989888A JP 20989888 A JP20989888 A JP 20989888A JP H0257933 A JPH0257933 A JP H0257933A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- temperature
- resistors
- heating
- diaphragm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000010438 heat treatment Methods 0.000 claims abstract description 52
- 239000004065 semiconductor Substances 0.000 claims abstract description 25
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 23
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 23
- 239000010703 silicon Substances 0.000 claims abstract description 23
- 239000000758 substrate Substances 0.000 claims abstract description 23
- 239000013078 crystal Substances 0.000 claims abstract description 22
- 239000012530 fluid Substances 0.000 claims description 27
- 238000004891 communication Methods 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 230000005611 electricity Effects 0.000 claims description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 abstract description 4
- 238000009530 blood pressure measurement Methods 0.000 abstract description 4
- 229910052759 nickel Inorganic materials 0.000 abstract description 2
- 239000010408 film Substances 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000007613 environmental effect Effects 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- 235000006693 Cassia laevigata Nutrition 0.000 description 2
- 241000522641 Senna Species 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 229940124513 senna glycoside Drugs 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229910000833 kovar Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Measuring Fluid Pressure (AREA)
Abstract
Description
【発明の詳細な説明】
[産業上の利用分野]
本発明は流体圧力を測定する圧力センサに関し、特に半
導体単結晶基板内に形成した歪ゲージを用いた圧力セン
サに係る。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pressure sensor for measuring fluid pressure, and particularly to a pressure sensor using a strain gauge formed in a semiconductor single crystal substrate.
[従来の技術]
近年、小型、軽量で高感度な圧力センサとして、半導体
結晶に外力を加えたとき半導体結晶の比抵抗が変化する
ピエゾ抵抗効果を利用した半導体圧力センサが自動車を
含む種々の分野で活用されている。この種半導体圧力セ
ンサとして、シリコン等の半導体単結晶の基板の中央部
に薄膜のダイヤフラムを加工形成し、このダイヤフラム
部に拡散抵抗層を形成して歪ゲージを構成した拡散型半
導体圧力センサが知られており、特にシリコン単結晶基
板のダイヤフラムを用いたシリコン圧力センサが活用さ
れている。[Prior Art] In recent years, semiconductor pressure sensors that utilize the piezoresistance effect, in which the resistivity of a semiconductor crystal changes when an external force is applied to the semiconductor crystal, have been used in various fields including automobiles as small, lightweight, and highly sensitive pressure sensors. It is used in As this type of semiconductor pressure sensor, a diffusion type semiconductor pressure sensor is known, in which a thin film diaphragm is processed and formed in the center of a semiconductor single crystal substrate such as silicon, and a diffused resistance layer is formed on this diaphragm to form a strain gauge. In particular, silicon pressure sensors using a diaphragm on a silicon single crystal substrate are being utilized.
シリコン圧力センサにおいては、上記ダイヤフラムに加
えられた流体圧力による歪に応じた拡散抵抗の変化を検
出して流体圧力を測定することとし、通常、流体圧力に
対して抵抗値が増加、減少する歪ゲージ一対を一組とし
て、これら二組でホイートストンブリッジを構成し、定
電流あるいは定電圧電源と接続して電気信号に変換し流
体圧力を測定することとしている。In silicon pressure sensors, fluid pressure is measured by detecting changes in diffusion resistance in response to strain due to fluid pressure applied to the diaphragm. Usually, the strain is such that the resistance value increases or decreases with respect to fluid pressure. A pair of gauges constitutes a Wheatstone bridge, which is connected to a constant current or constant voltage power source to convert it into an electrical signal and measure fluid pressure.
半導体圧力センサにおいては、外部の熱や機械的な歪に
対し鋭敏に反応するため、これらに影響されないように
構成すると共に、被測定流体の温度変化を含む外部環境
温度変化による半導体の非直線性温度特性を補償すべく
温度補償回路を接続することとしている。例えば上記シ
リコン圧力センサ用のホイートストンブリッジにおいて
、ゲージ抵抗に直列又は並列に補償抵抗を接続したり、
オペアンプで構成した増幅回路の帰還抵抗に温度特性を
持たせるといった方法がとられている。Semiconductor pressure sensors react sensitively to external heat and mechanical strain, so they are designed to be unaffected by these, and to avoid non-linearity in semiconductors due to external environmental temperature changes, including temperature changes in the fluid being measured. A temperature compensation circuit is connected to compensate for temperature characteristics. For example, in the Wheatstone bridge for the silicon pressure sensor mentioned above, a compensation resistor is connected in series or parallel to the gauge resistor,
One method is to give the feedback resistance of an amplifier circuit made up of operational amplifiers a temperature characteristic.
更に、特公昭59−41134号公報に記載のように、
出力段演算増幅器のフィードバック回路に圧力不感部の
ゲージ抵抗と固定抵抗を並列接続して挿入し温度補償を
行なうという技術もあり、これにより高精度の温度補償
が期待される。Furthermore, as described in Japanese Patent Publication No. 59-41134,
There is also a technology that performs temperature compensation by inserting a pressure-insensitive gauge resistor and a fixed resistor connected in parallel into the feedback circuit of the output stage operational amplifier, and this is expected to provide highly accurate temperature compensation.
上記の技術においては、温度補償用の抵抗が歪ゲージと
同一のゲージ抵抗であり半導体単結晶基板に歪ゲージを
形成する際同一工程で形成できるという利点がある。し
かし、温度補償用のゲージ抵抗、即ち拡散抵抗の抵抗値
を所定の値に正確に調整することは容易ではない。また
、これに並列接続する固定抵抗の抵抗値を調整するため
のトリミングも必要である。更に、上記の技術によれば
被測定流体の温度変化に対しある程度の対応が可能であ
るが、受動的対応に留まり、対応できる温度変化の範囲
には限度がある。The above technique has the advantage that the temperature compensation resistor is the same gauge resistor as the strain gauge and can be formed in the same step when forming the strain gauge on the semiconductor single crystal substrate. However, it is not easy to accurately adjust the resistance value of the temperature-compensating gauge resistor, that is, the diffused resistor, to a predetermined value. Further, trimming is also required to adjust the resistance value of the fixed resistor connected in parallel. Furthermore, although the above-mentioned technique can respond to temperature changes in the fluid to be measured to a certain extent, it remains a passive response and there is a limit to the range of temperature changes that can be accommodated.
そこで、本発明は歪ゲージ形成部を積極的に加熱してそ
の温度を一定温度に制御し、温度変化範囲が大きな被測
定流体に対しても安定した圧力測定ができるようにする
ことを目的とする。Therefore, an object of the present invention is to actively heat the strain gauge forming part and control its temperature to a constant temperature, so that stable pressure measurement can be performed even for a fluid to be measured that has a large temperature change range. do.
[課題を解決するための手段]
上記の目的を達成するため、本発明は一方の面を基準圧
の受圧面とし他方の面を連通路を介して被測定流体源に
連通し被測定流体の圧力の受圧面とした半導体単結晶基
板内に歪ゲージを形成し、該歪ゲージに生ずる歪を電気
信号に変換して前記被測定流体の圧力を検出する圧力セ
ンナにおいて、前記歪ゲージに近接して前記半導体単結
晶基板に配置した加熱抵抗体を備え、該加熱抵抗体に通
電し前記半導体単結晶基板を一定温度に加熱制御する加
熱制御回路を接続したものである。[Means for Solving the Problems] In order to achieve the above object, the present invention has one surface as a pressure-receiving surface for the reference pressure, and the other surface as a pressure-receiving surface for the fluid to be measured through a communication passage. In a pressure sensor that detects the pressure of the fluid to be measured by forming a strain gauge in a semiconductor single crystal substrate as a pressure receiving surface and converting the strain generated in the strain gauge into an electric signal, The heating resistor is provided with a heating resistor disposed on the semiconductor single crystal substrate, and is connected to a heating control circuit that energizes the heating resistor to control heating of the semiconductor single crystal substrate to a constant temperature.
特に、被測定流体源に連通し被測定流体を導入する連通
路を閉塞するように配置すると共に前記被測定流体の圧
力変動に応じて変形するダイヤフラム部を形成したシリ
コン基板と、該シリコン基板内の前記ダイヤフラム部に
形成した歪ゲージと、該歪ゲージに近接して前記ダイヤ
フラム部に取着した金属皮膜抵抗を備えたものとし、該
金属皮膜抵抗に通電して前記ダイヤフラム部を一定温度
に加熱制御する加熱制御回路を接続するとよい。In particular, a silicon substrate formed with a diaphragm portion that is arranged to close a communication path that communicates with a fluid source to be measured and introduces the fluid to be measured, and that deforms in response to pressure fluctuations of the fluid to be measured; a strain gauge formed on the diaphragm portion, and a metal film resistor attached to the diaphragm portion in proximity to the strain gauge, and heating the diaphragm portion to a constant temperature by applying electricity to the metal film resistor. It is recommended to connect a heating control circuit to control the temperature.
[作用]
上記のように構成された圧力センサにおいては、半導体
単結晶基板の一方の受圧面に基準圧が付与され、他方の
受圧面に被測定流体源からの被測定流体圧力が付与され
る。これらの圧力差により歪ゲージを含む半導体単結晶
基板に歪が生じ、この歪が歪ゲージにより電気信号に変
換される。[Operation] In the pressure sensor configured as described above, the reference pressure is applied to one pressure receiving surface of the semiconductor single crystal substrate, and the measured fluid pressure from the measured fluid source is applied to the other pressure receiving surface. . These pressure differences cause strain in the semiconductor single crystal substrate containing the strain gauge, and this strain is converted into an electrical signal by the strain gauge.
この場合において、歪ゲージに近接して半導体単結晶基
板に設けられた加熱抵抗体が加熱制御回路により通電さ
れて加熱され、半導体単結晶基板が例えば外部環境温度
変化の最高温度以上の一定温度に制御される。而して、
歪ゲージ形成部の温度が外部環境温度に影響されない一
定め温度に維持され、歪ゲージは圧力変化にのみ対応し
て所定の電気信号を出力する。In this case, a heating resistor provided on the semiconductor single-crystal substrate near the strain gauge is energized and heated by the heating control circuit, and the semiconductor single-crystal substrate is heated to a constant temperature higher than, for example, the maximum temperature of external environmental temperature changes. controlled. Then,
The temperature of the strain gauge forming portion is maintained at a constant temperature that is not affected by the external environmental temperature, and the strain gauge outputs a predetermined electrical signal in response only to pressure changes.
[実施例]
以下に本発明の圧力センサの望ましい実施例を図面を参
照して説明する。[Embodiments] Preferred embodiments of the pressure sensor of the present invention will be described below with reference to the drawings.
第1図は本発明の圧力センサの一実施例を示すもので、
本発明にいう半導体単結晶基板としてシリコン車結晶基
板を用い、正方形のシリコンチップ11の中央部が厚さ
数+μmに薄膜加工されダイヤフラムllaが形成され
ている。このダイヤフラムllaにボロン等の拡散によ
り拡散抵抗層の歪ゲージが四個形成されている。即ち、
第2図に示すようにダイヤフラムllaの中央部に拡散
抵抗、即ちゲージ抵抗R1乃至R4が形成されている。FIG. 1 shows an embodiment of the pressure sensor of the present invention.
A silicon wheel crystal substrate is used as the semiconductor single crystal substrate according to the present invention, and the central portion of the square silicon chip 11 is processed into a thin film with a thickness of several + μm to form a diaphragm lla. Four strain gauges of a diffused resistance layer are formed on this diaphragm lla by diffusion of boron or the like. That is,
As shown in FIG. 2, diffused resistors, ie, gauge resistors R1 to R4, are formed in the center of the diaphragm lla.
これらゲージ抵抗R1乃至R4は高ゲージ率を有し、ゲ
ージ抵抗R1,R3とゲージ抵抗R2,R4は相互に対
向して配置され、ダイヤフラムllaに圧力が加わった
ときゲージ抵抗R1、R3に正の抵抗値変化(R+ΔR
)が生じ、ゲージ抵抗R2,R4には負の抵抗値変化(
R−△R)が生ずる位置に夫々配置されている。These gauge resistors R1 to R4 have a high gauge factor, and the gauge resistors R1, R3 and the gauge resistors R2, R4 are arranged opposite each other, and when pressure is applied to the diaphragm lla, the gauge resistors R1, R3 have a positive Resistance value change (R+ΔR
) occurs, and a negative resistance value change (
R-ΔR) are placed at the positions where R-ΔR) occurs.
そして、第2図に明らかなように、ダイヤフラム11a
上のゲージ抵抗R1乃至R4の両側に本発明にいう加熱
抵抗体が配置されている。即ち、ダイヤフラム11a上
のシリコンチップ11上に例えばニッケル薄膜の金属皮
膜抵抗が蒸着されて加熱抵抗Rh1.Rh2が形成され
ている。これら加熱抵抗Rhl、Rh2は正の抵抗温度
係数を有し、そのゲージ率はR1乃至R4に比し遥かに
小さく、歪による抵抗値変化は無視し得る値とされてい
る。尚、これらのゲージ抵抗R1乃至R4は四個でなく
必要に応じ所望の数としてもよい。As is clear from FIG. 2, the diaphragm 11a
Heating resistors according to the present invention are arranged on both sides of the upper gauge resistors R1 to R4. That is, a metal film resistor such as a thin nickel film is deposited on the silicon chip 11 on the diaphragm 11a to form the heating resistor Rh1. Rh2 is formed. These heating resistors Rhl and Rh2 have positive temperature coefficients of resistance, and their gauge factors are much smaller than those of R1 to R4, so that changes in resistance due to strain are negligible. Note that the number of these gauge resistors R1 to R4 is not limited to four, but may be a desired number as necessary.
上記の構成になるシリコンチップ11はこれと同様の材
質即ちシリコンで形成された円筒体でその端面に金が蒸
着された台座12に半田により接合されている。而して
、台座12の中空部の一方の開口部がシリコンチップ1
1のダイヤフラム11aの裏面に対向している。The silicon chip 11 having the above structure is a cylindrical body made of the same material, ie, silicon, and is joined by solder to a pedestal 12 whose end surface has gold vapor-deposited thereon. Thus, one opening of the hollow part of the pedestal 12 is connected to the silicon chip 1.
It faces the back surface of the first diaphragm 11a.
シリコンチップ11が接合された台座12は、シリコン
チップ11の接合面と反対側の面にも金が蒸着され、中
央に連通孔を有しその周囲に複数の孔を有する円板状の
コバール製ステム13の中央部に半田接合されている。The pedestal 12 to which the silicon chip 11 is bonded is made of Kovar, which has a disc shape with gold vapor-deposited on the surface opposite to the bonding surface of the silicon chip 11, and has a communicating hole in the center and a plurality of holes around it. It is soldered to the center of the stem 13.
従って、台座12の中空部とステム13の連通孔が合致
し相互に連通している。このステム13の連通孔周囲に
はこれより大径の穴が設けられており、この穴に導圧バ
イブ23の一端が嵌着されている。Therefore, the hollow portion of the base 12 and the communication hole of the stem 13 match and communicate with each other. A hole with a larger diameter is provided around the communication hole of the stem 13, and one end of the pressure vibrator 23 is fitted into this hole.
ステム13の連通孔回りの孔には三木のリードビン14
(第1図中には内−木のみが表われている)が挿通され
ており、ダイヤフラムllaに形成されたゲージ抵抗R
1,R2,ゲージ抵抗R1、R4及びゲージ抵抗R3,
R4の夫々が両端でまとめられ、金線によって夫々三本
のリードピン14にワイヤボンディングされている。ま
たゲージ抵抗R2,R3の接続点はり−ドピン15を介
して接地されている。即ち、ダイヤフラム11a上に形
成された四個のゲージ抵抗R1乃至R4によりホイート
ストンブリッジが形成され、その入出力端子がリードピ
ン14及びこれに接続されたターミナル24を介して外
部回路に接続されるように構成されている。Miki's lead bin 14 is installed in the hole around the communicating hole of the stem 13.
(Only the inner tree is shown in Figure 1) is inserted through the gauge resistor R formed on the diaphragm lla.
1, R2, gauge resistance R1, R4 and gauge resistance R3,
Each of R4 is brought together at both ends and wire-bonded to each of the three lead pins 14 using a gold wire. Further, the connection point between the gauge resistors R2 and R3 is grounded via a doped pin 15. That is, a Wheatstone bridge is formed by the four gauge resistors R1 to R4 formed on the diaphragm 11a, and its input/output terminals are connected to an external circuit via the lead pin 14 and the terminal 24 connected thereto. It is configured.
加熱抵抗Rh1.Rh2は夫々一端がリードピン15を
介して接地され、他端がリードピン16に接続されター
ミナル24を介して後述する加熱制御回路に接続され、
適宜通電されて所定の熱量を発生するように構成されて
いる。Heating resistance Rh1. One end of each Rh2 is grounded via a lead pin 15, the other end is connected to a lead pin 16, and is connected to a heating control circuit to be described later via a terminal 24.
It is configured to be energized as appropriate to generate a predetermined amount of heat.
ステム13の孔とリードビン14乃至16の間隙はハー
メチックシールによって密封されている。そして、ステ
ム13の周囲にカップ状の金属製ケース21のフランジ
部が抵抗溶接によって接合され、ステム13とケース2
1との間に密閉された真空の基準圧室25が郭成されて
いる。尚、ケース21に連通孔を穿設しておき、ステム
13と接合後、基準圧室25内を真空状態とした後、あ
るいは所定圧の気体を充填した後、上記連通孔を半田で
塞ぐようにしてもよい。The gaps between the hole in the stem 13 and the lead bins 14 to 16 are hermetically sealed. Then, the flange portion of the cup-shaped metal case 21 is joined around the stem 13 by resistance welding, and the stem 13 and the case 2
1, a sealed vacuum reference pressure chamber 25 is defined between the two. Incidentally, a communication hole is drilled in the case 21, and after joining the stem 13 and making the inside of the reference pressure chamber 25 a vacuum state, or after filling the reference pressure chamber 25 with gas at a predetermined pressure, the communication hole is plugged with solder. You can also do this.
上記のように構成されたセンサエレメントが、中央に管
状の接続部31aを備え、この接続部31a内の連通孔
に連通ずる大径の孔を有する収容部31bを備えたイン
チハウジング31と、これと接合するカップ状のアウタ
ハウジング32内に収容され、樹脂33が充填される。The sensor element configured as described above includes an inch housing 31 having a tubular connecting portion 31a in the center and an accommodating portion 31b having a large diameter hole communicating with a communication hole in the connecting portion 31a; It is housed in a cup-shaped outer housing 32 that is joined to the outer housing 32, and is filled with resin 33.
このとき、導圧バイブ23の開口端は、接続部31aの
連通孔の開口端とフィルタ34を介して対向し、収容部
31bと導圧バイブ23の間隙に0リング35が挿入さ
れる。At this time, the open end of the pressure vibrator 23 faces the open end of the communication hole of the connecting portion 31a with the filter 34 in between, and the O-ring 35 is inserted into the gap between the accommodating portion 31b and the pressure vibrator 23.
而して、シリコンチップ11のダイヤフラム11aの一
方の面、即ち表面は基準圧室25内の基準圧力の受圧面
となり、他方の面、即ち裏面は台座12及びステム13
の連通孔、導圧バイブ23、インナハウジング31の接
続部31aを介して図示しない流体圧力源に連通し流体
圧力の受圧面となる。One surface of the diaphragm 11a of the silicon chip 11, that is, the front surface, becomes a pressure receiving surface for the reference pressure in the reference pressure chamber 25, and the other surface, that is, the back surface, serves as a pressure receiving surface for the pedestal 12 and the stem 13.
It communicates with a fluid pressure source (not shown) through the communication hole, the pressure guiding vibrator 23, and the connecting portion 31a of the inner housing 31, and serves as a pressure receiving surface for fluid pressure.
上記圧力センサの接続部31aは流体圧力源、例えば内
燃機関の吸気管に接続され、流体圧力たる吸気管圧力即
ち吸気負圧がシリコンチップ11のダイヤフラムlla
に伝達される。ダイヤフラムllaの裏面に吸気負圧が
伝達されると、ダイヤフラムlla上のゲージ抵抗R1
乃至R4に基準圧室25内の圧力との圧力差に応じた応
力が生ずる。本実施例では基準圧室25内を真空として
いるので吸気管圧力の絶対値に対応した応力となる。こ
の応力に従ってゲージ抵抗R1乃至R4の抵抗率がピエ
ゾ抵抗効果により変化する。The connection part 31a of the pressure sensor is connected to a fluid pressure source, for example, an intake pipe of an internal combustion engine, and the fluid pressure, that is, the intake pipe pressure, that is, the intake negative pressure is applied to the diaphragm lla of the silicon chip 11.
transmitted to. When intake negative pressure is transmitted to the back surface of diaphragm lla, gauge resistance R1 on diaphragm lla
A stress corresponding to the pressure difference between the pressure inside the reference pressure chamber 25 and the pressure inside the reference pressure chamber 25 is generated between R4 and R4. In this embodiment, since the inside of the reference pressure chamber 25 is set to a vacuum, the stress corresponds to the absolute value of the intake pipe pressure. According to this stress, the resistivity of the gauge resistors R1 to R4 changes due to the piezoresistance effect.
一方、これらのゲージ抵抗R1乃至R4で構成されたホ
イートストンブリッジに対してリードビン14の一木に
より定電圧が印加されており、ゲージ抵抗R1乃至R4
の抵抗率の変化に応じた電圧がリードビン14の他の二
本及びターミナル24を介して出力される。尚、接続部
31aと導圧バイブ23内との圧力差によって、気体流
が生ずるが、ダイヤフラムlla部への埃等の進入はフ
ィルタ34によって阻止される。On the other hand, a constant voltage is applied to the Wheatstone bridge made up of these gauge resistors R1 to R4 by a piece of lead bin 14, and the gauge resistors R1 to R4
A voltage corresponding to the change in resistivity of the lead bin 14 is outputted via the other two lead bins 14 and the terminal 24. Although a gas flow is generated due to the pressure difference between the connecting portion 31a and the inside of the pressure-guiding vibrator 23, the filter 34 prevents dust and the like from entering the diaphragm lla portion.
また、加熱抵抗Rhl、Rh2にもリードビン16を介
して後述する加熱制御回路により電流が供給されており
、所定の熱量を発し、近傍のゲージ抵抗R1乃至R4が
加熱され一定温度に制御されている。即ち、ゲージ抵抗
R1乃至R4は被測定流体を含む外部環境の温度変化に
影響されない程度の一定温度に加熱されている。In addition, current is supplied to the heating resistors Rhl and Rh2 via the lead bin 16 by a heating control circuit, which will be described later, and generates a predetermined amount of heat, which heats the nearby gauge resistors R1 to R4 and controls them to a constant temperature. . That is, the gauge resistors R1 to R4 are heated to a constant temperature that is not affected by temperature changes in the external environment including the fluid to be measured.
第3図は上記圧力センサの電気回路図を示し、上述のゲ
ージ抵抗R1乃至R4で構成されるホイートストンブリ
ッジに抵抗R5乃至R8及びオペアンプOPI及びOP
2から成る差動増幅回路が接続され、定電圧電源VCC
に接続されている。これにより上記ホイートストンブリ
ッジの出力が増幅されて出力VOとなると共に所定のイ
ンピーダンス変換が行なわれる。FIG. 3 shows an electrical circuit diagram of the pressure sensor, in which the Wheatstone bridge composed of the gauge resistors R1 to R4 is connected to resistors R5 to R8 and operational amplifiers OPI and OP.
A differential amplifier circuit consisting of 2 is connected to the constant voltage power supply VCC.
It is connected to the. As a result, the output of the Wheatstone bridge is amplified to become the output VO, and a predetermined impedance conversion is performed.
また、正の抵抗温度係数の加熱抵抗Rhl、Rh2を含
み抵抗R11、R12及びR13により別にホイートス
トンブリッジが構成され、オペアンプOP3及びトラン
ジスタTriと共に加熱制御回路3が構成されている。Further, a Wheatstone bridge is separately constituted by the resistors R11, R12 and R13 including the heating resistors Rhl and Rh2 having a positive resistance temperature coefficient, and the heating control circuit 3 is constituted together with the operational amplifier OP3 and the transistor Tri.
加熱制御回路3においては、電源v11からトランジス
タTriを介して加熱抵抗Rh1.Rh2に電流が供給
されて発熱し、近傍のゲージ抵抗R1乃至R4を含むダ
イヤフラムllaを加熱する。そして、加熱抵抗Rhl
、Rh2は温度上昇と共に抵抗値が増大し、所定の加熱
温度に達してホイートストンブリッジの平衡条件が成立
すると、オペアンプOP3の出力が低レベルとなりトラ
ンジスタTriが遮断され加熱抵抗Rh+。In the heating control circuit 3, the heating resistor Rh1. A current is supplied to Rh2 to generate heat, which heats the diaphragm lla including the nearby gauge resistors R1 to R4. And heating resistance Rhl
, Rh2 increase in resistance as the temperature rises, and when a predetermined heating temperature is reached and the equilibrium condition of the Wheatstone bridge is satisfied, the output of the operational amplifier OP3 becomes a low level and the transistor Tri is cut off, causing the heating resistor Rh+.
Rh2の発熱作用が停止する。The exothermic action of Rh2 stops.
一方、ゲージ抵抗R1乃至R4を含むダイヤフラムll
aの温度が低下し、従って加熱抵抗Rhl、Rh2の温
度が低下して抵抗値が減少すると、ホイートストンブリ
ッジの平衡条件がくずれ、オペアンプOP3の出力が高
レベルとなり、トランジスタTriが駆動され、前述と
同様に所定の加熱温度となるまで電源電流が供給される
。On the other hand, a diaphragm ll including gauge resistors R1 to R4
When the temperature of a decreases, and therefore the temperature of the heating resistors Rhl and Rh2 decreases, and the resistance value decreases, the equilibrium condition of the Wheatstone bridge collapses, the output of the operational amplifier OP3 becomes high level, the transistor Tri is driven, and the above-mentioned state occurs. Similarly, power supply current is supplied until a predetermined heating temperature is reached.
而して、ゲージ抵11i%R1乃至R4を含むダイヤフ
ラムIlaは加熱抵抗Rhl、Rh2により以下のよう
に一定の温度に加熱制御される。即ち、加熱抵抗Rhl
、Rh2の抵抗値(夫々Rh+ 。The diaphragm Ila including the gauge resistors 11i% R1 to R4 is heated and controlled to a constant temperature by the heating resistors Rhl and Rh2 as follows. That is, the heating resistance Rhl
, Rh2 resistance value (respectively Rh+.
Rh2とする)の温度特性は次式で表わされる。The temperature characteristics of Rh2) are expressed by the following equation.
Rhl冨Rh、。(1+αT)。Rhl Tomi Rh. (1+αT).
Rh2 =Rh2゜(1+αT)
ここで、Rhl。、Rh2゜はRh、、Rh2の基準抵
抗値、Tは両者の温度、αは温度係数を示す。Rh2 =Rh2゜(1+αT) Here, Rhl. , Rh2° is the reference resistance value of Rh, , Rh2, T is the temperature of both, and α is the temperature coefficient.
そして、ホイートストンブリッジの平衡条件からR+5
(Rh+a+Rh*。)(1+αT)=R11R12と
なり、T=
[RIIRI2−RI3(Rh+o+Rhzo)]/R
+sαとなる。Then, from the Wheatstone bridge equilibrium condition, R+5
(Rh+a+Rh*.)(1+αT)=R11R12, T= [RIIRI2-RI3(Rh+o+Rhzo)]/R
+sα.
ここで、R11+ R1□+ R13は夫々抵抗R11
゜R12,R13の抵抗値を示す。Here, R11+R1□+R13 are each resistance R11
゜Resistance values of R12 and R13 are shown.
上記の加熱抵抗Rhl、Rh2の温度Tは加熱制御回路
3により雰囲気温度に拘らず一定の温度に制御し得る。The temperature T of the heating resistors Rhl and Rh2 can be controlled to a constant temperature by the heating control circuit 3 regardless of the ambient temperature.
従って、この温度Tを圧力センサとしての使用温度範囲
の上限値より高温の所定値となるように抵抗値R目n
R12+ Rl!+ Rh lo+Rh20及び温度係
数αを設定することにより、加熱抵抗Rhl、Rh2の
近傍に配置されたゲージ抵抗R1乃至R4が上記上限値
より高温の一定温度に制御される。換言すれば、近傍の
ゲージ抵抗R1乃至R4の温度が圧力検出時における雰
囲気温度の上限値より高温の一定温度に維持されるよう
に、加熱抵抗Rhl、Rh2の加熱温度が制御される。Therefore, the resistance value Rth n is set so that this temperature T becomes a predetermined value higher than the upper limit of the operating temperature range as a pressure sensor.
R12+Rl! +Rh By setting lo+Rh20 and the temperature coefficient α, the gauge resistors R1 to R4 arranged near the heating resistors Rhl and Rh2 are controlled to a constant temperature higher than the above upper limit value. In other words, the heating temperatures of the heating resistors Rhl and Rh2 are controlled so that the temperatures of the nearby gauge resistors R1 to R4 are maintained at a constant temperature higher than the upper limit of the ambient temperature at the time of pressure detection.
ゲージ抵抗R1乃至R4はゲージ率が大であると共に所
定の温度特性を有しているが、圧力検出時の雰囲気温度
が温度特性による抵抗値の変動が生じない程度化加熱さ
れるので、ゲージ抵抗R1乃至R4は検出圧力のみをパ
ラメータとする抵抗値を示すこととなる。即ち、ゲージ
抵抗R1乃至R4の温度は使用状態での雰囲気温度より
高温の一定温度に維持され、従ってホイートストンブリ
ッジの出力■。は圧力のみの関数となる。Gauge resistors R1 to R4 have large gauge factors and predetermined temperature characteristics, but since the ambient temperature at the time of pressure detection is heated to a level that does not cause resistance value fluctuations due to temperature characteristics, the gauge resistors R1 to R4 represent resistance values using only the detected pressure as a parameter. That is, the temperature of the gauge resistors R1 to R4 is maintained at a constant temperature higher than the ambient temperature during use, and therefore the output of the Wheatstone bridge is . is a function of pressure only.
第3図に示した電気回路を構成するオペアンプOPI乃
至OP3を含む回路素子は厚膜抵抗基板(図示せず)に
実装され、第1図に記載の圧力センサと共にプリント配
線基板(図示せず)に配設されてセンナユニットが構成
される。そして、このセンサユニットが例えば内燃機関
の吸気管圧力測定用に供される。尚、上記電気回路のI
C化を更に進めて第1図の圧力センサ内に組み込むこと
も可能である。The circuit elements including operational amplifiers OPI to OP3 that constitute the electric circuit shown in FIG. 3 are mounted on a thick film resistance board (not shown), and together with the pressure sensor shown in FIG. 1 are mounted on a printed wiring board (not shown). The senna unit is configured by disposing the senna unit. This sensor unit is used, for example, to measure intake pipe pressure of an internal combustion engine. In addition, I of the above electric circuit
It is also possible to further advance the C conversion and incorporate it into the pressure sensor shown in FIG.
上記の実施例においては、加熱抵抗Rhl。In the above example, the heating resistor Rhl.
Rh2としてゲージ率の低い金属薄膜抵抗を用いられて
おり、ダイヤフラムllaに圧力が加わり加熱抵抗Rh
l、Rh2に歪が生じたときにも抵抗値の変化が生ずる
ことなく、抵抗値は実質的に温度のみの関数となってい
る。しかし、加熱抵抗Rhl、Rh2としてゲージ抵抗
R1乃至R4と同一の拡散抵抗を用いることも可能であ
る。但、ゲージ抵抗即ち拡散抵抗は当然乍らゲージ率が
大であるので、これを小さくするように構成しなければ
ならない。A metal thin film resistor with a low gauge factor is used as Rh2, and pressure is applied to the diaphragm lla, causing the heating resistor Rh.
Even when strain occurs in L and Rh2, the resistance value does not change, and the resistance value is substantially a function only of temperature. However, it is also possible to use the same diffused resistors as the gauge resistors R1 to R4 as the heating resistors Rhl and Rh2. However, since the gauge resistance, that is, the diffused resistance, naturally has a large gauge factor, it must be configured to reduce this.
例えば第4図に示したように、所定方向に圧力が加わっ
たとぎに、抵抗値が増大する部分に加熱抵抗Rhlを、
抵抗値が減少する部分に加熱抵抗Rh2を形成し、圧力
変化に応じた両者の抵抗値変化が相殺されるように配置
することが必要である。これにより、加熱抵抗Rhl、
Rh2は圧力変化に対し全体としての抵抗値は変化せず
、温度のみの関数となる。従って、シリコンチップ11
にゲージ抵抗R1乃至R4を形成する際、同時に加熱抵
抗Rhl、Rh2を形成することができる。For example, as shown in Fig. 4, a heating resistor Rhl is placed at a portion where the resistance value increases when pressure is applied in a predetermined direction.
It is necessary to form the heating resistor Rh2 in a portion where the resistance value decreases and arrange it so that the changes in both resistance values in response to pressure changes are canceled out. As a result, the heating resistance Rhl,
The overall resistance value of Rh2 does not change with respect to pressure changes, and is a function only of temperature. Therefore, silicon chip 11
When forming the gauge resistors R1 to R4, the heating resistors Rhl and Rh2 can be formed at the same time.
[発明の効果]
本発明は上述のように構成されているので、以下に記載
する効果を奏する。[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below.
即ち、加熱制御回路により加熱抵抗体が一定温度に制御
され、半導体単結晶基板に形成された歪ゲージが使用状
態における上限温度より高温の一定の温度に維持され得
るので、被測定流体を含む外部環境の温度変化に影響さ
れることなく安定した圧力測定を行なうことができる。That is, the heating resistor is controlled to a constant temperature by the heating control circuit, and the strain gauge formed on the semiconductor single crystal substrate can be maintained at a constant temperature higher than the upper limit temperature in the operating state. Stable pressure measurement can be performed without being affected by environmental temperature changes.
また、被測定流体に水分が混入していても半導体単結晶
基板は加熱抵抗体により高温霊囲気にあるので氷結する
ことはない。Further, even if moisture is mixed in the fluid to be measured, the semiconductor single crystal substrate is kept in a high-temperature atmosphere by the heating resistor, so it will not freeze.
特に、ダイヤフラム部に金属皮膜抵抗を取着したものに
あっては抵抗値を温度係数のみの関数として一定温度に
加熱制御することができるので、ダイヤフラム部の圧力
変動の影響をうけることなく安定した加熱制御を行なう
ことができる。In particular, with metal film resistors attached to the diaphragm, the resistance value can be heated to a constant temperature as a function only of the temperature coefficient, so it is stable without being affected by pressure fluctuations in the diaphragm. Heating control can be performed.
第1図は本発明の圧力センサの一実施例の縦断面図、
第2図は上記実施例の圧力センサにおけるシリコンチッ
プの平面図、
第3図は、上記実施例の圧力センサの電気回路図、
第4図は上記実施例の圧力センサにおける加熱抵抗体の
別の実施例を示すシリコンチップの平面図である。
11・・・シリコンチップ(半導体単結晶基板)11a
・・・ダイヤフラム。
12・・・台座。
14.15.16・・・リードビン。
23・・・導圧バイブ。
25・・・基準圧室。
R1〜R4・・・ゲージ抵抗。FIG. 1 is a vertical cross-sectional view of an embodiment of the pressure sensor of the present invention, FIG. 2 is a plan view of a silicon chip in the pressure sensor of the above embodiment, and FIG. 3 is an electrical circuit diagram of the pressure sensor of the above embodiment. , FIG. 4 is a plan view of a silicon chip showing another embodiment of the heating resistor in the pressure sensor of the above embodiment. 11...Silicon chip (semiconductor single crystal substrate) 11a
...Diaphragm. 12...Pedestal. 14.15.16...Lead bin. 23... pressure vibration. 25...Reference pressure chamber. R1 to R4... Gauge resistance.
Claims (2)
を介して被測定流体源に連通し被測定流体の圧力の受圧
面とした半導体単結晶基板内に歪ゲージを形成し、該歪
ゲージに生ずる歪を電気信号に変換して前記被測定流体
の圧力を検出する圧力センサにおいて、前記歪ゲージに
近接して前記半導体単結晶基板に配置した加熱抵抗体を
備え、該加熱抵抗体に通電し前記半導体単結晶基板を一
定温度に加熱制御する加熱制御回路を接続したことを特
徴とする圧力センサ。(1) A strain gauge is formed in a semiconductor single crystal substrate, with one surface as a pressure receiving surface for the reference pressure and the other surface as a pressure receiving surface for the pressure of the fluid to be measured and communicating with the source of the fluid to be measured via a communication path. , a pressure sensor that detects the pressure of the fluid to be measured by converting strain occurring in the strain gauge into an electrical signal, comprising a heating resistor disposed on the semiconductor single crystal substrate in proximity to the strain gauge; A pressure sensor characterized in that a heating control circuit is connected to conduct electricity to a resistor to control heating of the semiconductor single crystal substrate to a constant temperature.
路を閉塞するように配置すると共に前記被測定流体の圧
力変動に応じて変形するダイヤフラム部を形成したシリ
コン基板と、該シリコン基板内の前記ダイヤフラム部に
形成した歪ゲージと、該歪ゲージに近接して前記ダイヤ
フラム部に取着した金属皮膜抵抗を備え、該金属皮膜抵
抗に通電して前記ダイヤフラム部を一定温度に加熱制御
する加熱制御回路を接続したことを特徴とする圧力セン
サ。(2) A silicon substrate formed with a diaphragm portion that is arranged to close a communication path that communicates with a fluid source to be measured and introduces the fluid to be measured, and that deforms in response to pressure fluctuations of the fluid to be measured; and the silicon substrate. A strain gauge formed on the diaphragm part in the diaphragm part, and a metal film resistor attached to the diaphragm part in proximity to the strain gauge, and the metal film resistor is energized to control heating of the diaphragm part to a constant temperature. A pressure sensor characterized by being connected to a heating control circuit.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20989888A JPH0257933A (en) | 1988-08-24 | 1988-08-24 | Pressure sensor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20989888A JPH0257933A (en) | 1988-08-24 | 1988-08-24 | Pressure sensor |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0257933A true JPH0257933A (en) | 1990-02-27 |
Family
ID=16580473
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP20989888A Pending JPH0257933A (en) | 1988-08-24 | 1988-08-24 | Pressure sensor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0257933A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001509267A (en) * | 1997-01-15 | 2001-07-10 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング | Semiconductor pressure sensor |
US9683907B2 (en) | 2014-03-25 | 2017-06-20 | Seiko Epson Corporation | Physical quantity sensor, altimeter, electronic apparatus, and moving object |
CN113474281A (en) * | 2019-01-25 | 2021-10-01 | 罗伯特·博世有限公司 | MEMS sensor and method for operating a MEMS sensor |
-
1988
- 1988-08-24 JP JP20989888A patent/JPH0257933A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001509267A (en) * | 1997-01-15 | 2001-07-10 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング | Semiconductor pressure sensor |
US9683907B2 (en) | 2014-03-25 | 2017-06-20 | Seiko Epson Corporation | Physical quantity sensor, altimeter, electronic apparatus, and moving object |
CN113474281A (en) * | 2019-01-25 | 2021-10-01 | 罗伯特·博世有限公司 | MEMS sensor and method for operating a MEMS sensor |
JP2022518758A (en) * | 2019-01-25 | 2022-03-16 | ロベルト・ボッシュ・ゲゼルシャフト・ミト・ベシュレンクテル・ハフツング | MEMS Sensors and Methods for Operating MEMS Sensors |
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