阅读说明：本技术 传感器装置 (Sensor device ) 是由 志水圣 大野和幸 于 2018-11-30 设计创作，主要内容包括：传感器装置具备传感器元件(151)和电路芯片(160)。传感器元件检测测量对象的温度,输出与测量对象的温度对应的温度信号。电路芯片输入温度信号,进行信号处理。温度信号包含由测量对象与传感器元件的温度差引起的传感器误差。在传感器误差包含在温度信号中的情况下,发生与传感器误差对应的、传感器元件与电路芯片的温度差。电路芯片具有检测电路芯片的温度的检测元件(165)。电路芯片根据检测元件所检测到的电路芯片的温度与传感器元件所检测到的测量对象的温度的温度差,修正温度信号,将修正后的温度信号向外部输出。(The sensor device is provided with a sensor element (151) and a circuit chip (160). The sensor element detects a temperature of a measurement target and outputs a temperature signal corresponding to the temperature of the measurement target. The circuit chip inputs the temperature signal and processes the signal. The temperature signal contains a sensor error caused by a temperature difference between the measurement object and the sensor element. When the sensor error is included in the temperature signal, a temperature difference between the sensor element and the circuit chip occurs in accordance with the sensor error. The circuit chip has a detection element (165) for detecting the temperature of the circuit chip. The circuit chip corrects the temperature signal based on a temperature difference between the temperature of the circuit chip detected by the detection element and the temperature of the measurement object detected by the sensor element, and outputs the corrected temperature signal to the outside.)

1. A kind of sensor device is disclosed, which comprises a sensor body,

the disclosed device is provided with:

a sensor element (151) that detects the temperature of a measurement object and outputs a temperature signal corresponding to the temperature of the measurement object; and

a circuit chip (160) for inputting the temperature signal and performing signal processing;

the temperature signal includes a sensor error caused by a temperature difference between the measurement object and the sensor element;

generating a temperature difference between the sensor element and the circuit chip corresponding to the sensor error when the sensor error is included in the temperature signal;

the circuit chip has a detection element (165) for detecting the temperature of the circuit chip, corrects the temperature signal based on a temperature difference between the temperature of the circuit chip detected by the detection element and the temperature of the measurement object detected by the sensor element, and outputs the corrected temperature signal to the outside.

2. The sensor device as set forth in claim 1,

the sensor error increases at a constant rate of increase with respect to a temperature difference between the circuit chip and the sensor element;

the circuit chip generates an error correction value that decreases at a constant rate of decrease at the same rate as the constant rate of increase with respect to the temperature difference between the circuit chip and the sensor element, and adds the error correction value to the temperature signal to correct the sensor error.

3. The sensor device according to claim 1 or 2,

the sensor element detects not only the temperature of the measurement target but also at least any one of 1 of pressure, flow rate, viscosity, humidity, and acceleration of the measurement target as a physical quantity different from the temperature of the measurement target.

4. The sensor device according to claim 3, wherein,

the circuit chip corrects a physical quantity different from the temperature of the measurement object based on the corrected temperature signal.

5. The sensor device according to any one of claims 1 to 4,

the sensor element and the detection element are formed of a resistance element (152) formed of a P-type semiconductor whose resistance value changes in accordance with the temperature of the measurement object.

6. The sensor device of claim 5, wherein the sensor device is a single-chip microprocessor,

the sensor element and the detection element have positive temperature coefficients of resistance, and the sensor element and the detection element have impurity concentrations adjusted so that the respective temperature coefficients of resistance are equal to each other.

Technical Field

The present disclosure relates to a sensor device that detects a temperature of a measurement object.

Background

Conventionally, for example, patent document 1 proposes a sensor device including: the temperature measuring device includes a sensor element that detects a temperature of a measurement object, and a circuit chip that performs signal processing on a temperature signal of the sensor element. The sensor element and the circuit chip are separately provided as independent devices.

Disclosure of Invention

However, in the above-described conventional technique, since the sensor element and the circuit chip are separately disposed, the influence of heat received by the sensor element is different from the influence of heat received by the circuit chip. Therefore, there is a possibility that a sensor error due to a temperature difference between the measurement target and the sensor element occurs by heat transmitted from the circuit chip to the measurement target via the sensor element.

An object of the present disclosure is to provide a sensor device capable of reducing a sensor error due to a temperature difference between a measurement object and a sensor element.

The sensor device according to one aspect of the present disclosure includes a sensor element and a circuit chip. The sensor element detects a temperature of a measurement target and outputs a temperature signal corresponding to the temperature of the measurement target. The circuit chip inputs the temperature signal and processes the signal.

The temperature signal contains a sensor error due to a temperature difference between the measurement object and the sensor element. When a sensor error is included in the temperature signal, a temperature difference between the sensor element and the circuit chip occurs in accordance with the sensor error.

The circuit chip includes a detection element for detecting a temperature of the circuit chip, and corrects the temperature signal based on a temperature difference between the temperature of the circuit chip detected by the detection element and a temperature of the measurement target detected by the sensor element, and outputs the corrected temperature signal to the outside.

Thus, since the correlation between the temperature difference between the circuit chip and the sensor element and the sensor error is used, the sensor error can be corrected based on the temperature difference. Thus, a sensor error due to a temperature difference between the measurement object and the sensor element can be reduced.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings.

Fig. 1 is a sectional view of a sensor device according to embodiment 1.

Fig. 2 is a block diagram of a sensor chip and a circuit chip.

Fig. 3 is a diagram showing a specific circuit of the sensor chip and the circuit chip.

Fig. 4 is a diagram showing a heat circuit corresponding to the configuration shown in fig. 1.

Fig. 5 is a diagram showing a correlation between a temperature difference between the circuit chip and the sensor element and a sensor error.

Fig. 6 is a diagram showing an error correction value for a temperature difference between the circuit chip and the sensor element.

Fig. 7 is a diagram showing the corrected sensor error.

Fig. 8 is a diagram showing a sensor error due to the influence of the outside air temperature and a corrected sensor error.

Fig. 9 is a diagram showing a sensor error due to the influence of heat generated by the circuit chip and a corrected sensor error.

Fig. 10 is a cross-sectional view showing a difference in flow velocity between a measurement target flowing outside the casing and a measurement target flowing inside the casing.

Fig. 11 is a diagram showing a sensor error due to the influence of the response delay of the sensor element and a corrected sensor error.

Detailed Description

Hereinafter, a plurality of embodiments for implementing the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals are given to portions corresponding to the matters described in the preceding embodiment, and redundant description may be omitted. In the case where only a part of the structure is described in each embodiment, other embodiments described in the foregoing may be applied to other parts of the structure. Not only the combinations of the combinable portions are specifically and explicitly described in the respective embodiments, but also the embodiments may be partially combined without explicit description as long as no particular trouble occurs in the combination.

(embodiment 1)

Hereinafter, embodiment 1 of the present disclosure will be described with reference to the drawings. The sensor device according to the present embodiment is configured to be able to detect the temperature of a measurement target. The sensor device is fixed to, for example, a pipe as an object to be mounted, and detects a temperature of a measurement object in the pipe. The measurement object is, for example, a medium such as oil. The measurement target may be other medium such as liquid such as refrigerant or gas such as gas.

As shown in fig. 1, the sensor device 100 includes a case 110, a molding resin portion 120, a potting (potting) resin portion 130, a molding resin portion 140, and a sensor chip 150.

The case 110 is a hollow box formed by machining a metal material such as SUS. A male screw portion 111 that can be screwed to a pipe 200 to be attached is formed on the outer peripheral surface of the housing 110.

The housing 110 has a medium introduction portion 112 on one end side and an opening portion 113 on the other end side. The medium introduction portion 112 is a cylindrical portion in which a medium introduction hole 114 is formed. The medium introduction hole 114 communicates with the opening 113. The opening 113 of the housing 110 is surrounded by a peripheral wall 115. The housing 110 has a part of the medium introduction portion 112 fixed to a through screw hole 202 provided in a wall thickness portion 201 of the pipe 200. Thus, the distal end 116 of the medium introduction portion 112 is positioned inside the pipe 200. For example, the pipe 200 is filled with oil to be measured.

Further, the casing 110 has a diffuser 117 at the front end 116 of the medium introduction portion 112. The diffuser 117 is a portion protruding from the wall thickness portion 201 of the pipe 200 to the hollow portion of the pipe 200, and is provided with a plurality of holes 118. The diffuser 117 functions to guide the measurement target to the medium introduction hole 114 through any one of the plurality of holes 118.

The molded resin portion 120 is a portion constituting a connector for electrically connecting the sensor device 100 and an external device. The molded resin part 120 is formed of a resin material such as PPS, and has one end as a fixing part 121 fixed to the opening 113 of the case 110 and the other end as a connector part 122. The fixing portion 121 has a recess 123 recessed toward the connector portion 122.

The molded resin portion 120 is integrally molded with a terminal 124 by insert molding. One end side of the terminal 124 is sealed to the fixing portion 121, and the other end side is insert-molded into the molding resin portion 120 so as to be exposed inside the connector portion 122. One end side of the terminal 124 is received in the recess 123 by a part of the mold resin portion 140 and connected to an electric component of the mold resin portion 140.

In the molded resin part 120, in a state where the fixing part 121 is fitted into the opening 113 of the housing 110 via the O-ring 125, an end portion of the peripheral wall 115 of the housing 110 is fixed by crimping so as to press the fixing part 121.

Potting resin portion 130 is formed of a resin material such as epoxy resin, and is filled in a gap between concave portion 123 of molding resin portion 120 and mold resin portion 140. The potting resin portion 130 seals and protects a part of the mold resin portion 140 and a joint portion of the terminal 124 from oil as a measurement target.

The mold resin portion 140 is a member that holds the sensor chip 150. The mold resin section 140 is formed in a columnar shape having one end 141 and the other end 142 opposite to the one end 141. The mold resin portion 140 holds the sensor chip 150 on the side of the one end portion 141.

The mold resin portion 140 seals a part of the lead frame 143 and the circuit chip 160. The lead frame 143 is a member serving as a base on which the sensor chip 150 and the circuit chip 160 are mounted.

The other end of the lead frame 143 is exposed from the other end 142 of the mold resin portion 140 and connected to one end of the terminal 124. Further, the lead frame 143 may be divided into a plurality of parts. In this case, the electrical connection may be made by a bonding wire. Both the lead frame 143 and the terminal 124 may be connected by a bonding wire.

The circuit chip 160 is an IC chip in which a semiconductor integrated circuit such as a memory is formed. The circuit chip 160 is formed using a semiconductor substrate or the like. The circuit chip 160 supplies power to the sensor chip 150, and performs signal processing of a temperature signal based on a signal processing value set in advance by inputting a temperature signal from the sensor chip 150. The signal processing value is an adjustment value for amplifying, calculating, correcting, or the like the signal value of the temperature signal. The circuit chip 160 is electrically connected to the sensor chip 150 through the lead frame 143 by a bonding wire not shown.

The sensor chip 150 is an electronic component that detects the temperature of a measurement object. The sensor chip 150 is mounted on the lead frame 143 by silver paste or the like, for example. Although not shown, the sensor chip 150 is configured to have a plate-shaped laminated substrate formed by laminating a plurality of layers. The plurality of layers are stacked as a wafer level package, and a plurality of wafers are processed by a semiconductor process or the like, and then diced for each sensor chip 150.

As shown in fig. 2, the sensor chip 150 has a sensor element 151 that detects the temperature of a measurement object. The sensor element 151 is a sensing unit that outputs a temperature signal corresponding to the temperature of the measurement target. The sensor element 151 is constituted by a plurality of piezo-resistive elements 152 whose resistance value changes in accordance with the temperature of the measurement object. Each of the piezoresistive elements 152 is a diffusion resistance of a semiconductor layer formed in a plurality of layers of the laminated substrate by ion implantation.

The semiconductor layer is, for example, an N-type single crystal silicon layer. Each of the piezo-resistive elements 152 is formed as a P + -type region or a P-type region. That is, each of the piezo-resistive elements 152 is formed as a P-type semiconductor. In addition, other electrical elements such as a wire and a pad are formed on the sensor chip 150.

The piezo-resistive elements 152 are electrically connected to form a Wheatstone bridge (Wheatstone bridge) circuit. The wheatstone bridge circuit is supplied with a constant current power supply from the circuit chip 160. Thus, a voltage corresponding to the temperature of the measurement target can be detected as a temperature signal by utilizing the piezoresistance effect of each piezoresistance element 152.

That is, the sensor chip 150 detects a change in resistance of the plurality of piezoresistive elements 152 corresponding to heat received by the laminated substrate from the measurement object as a bridge voltage of the wheatstone bridge circuit. And, the sensor chip 150 outputs the bridge voltage as a temperature signal. The sensor chip 150 is sealed on the one end portion 141 side of the mold resin portion 140 so that a portion corresponding to the temperature detection portion is exposed.

On the other hand, as shown in fig. 2, the circuit chip 160 includes a constant current circuit section 161, a correction circuit section 162, a front-stage adjustment section 163, and a rear-stage adjustment section 164. The constant current circuit unit 161 is a circuit unit that supplies a constant current power supply to the sensor element 151 of the sensor chip 150.

The correction circuit 162 is a circuit that generates a correction value for correcting a sensor error included in the temperature signal. The correction circuit 162 includes a detection element 165 and an error adjustment unit 166. The detection element 165 detects the temperature of the circuit chip 160. The detection element 165 is a temperature sensitive resistor whose resistance value changes according to temperature. The detection element 165 is built in the circuit chip 160.

For example, an N-type single crystal silicon substrate is used as the circuit chip 160. The detection element 165 is formed as a P + type region or a P type region on the single crystal silicon substrate. That is, the detection element 165 is formed as a P-type semiconductor. The detection element 165 is a resistor having a positive temperature coefficient of resistance. The detection element 165 is a resistance element similar to the aforementioned piezoresistive element 152. The sensor element 151 and the detection element 165 are each formed of a resistance element whose impurity concentration is adjusted so that the respective resistance temperature coefficients have the same value.

The error adjusting unit 166 receives the detection signal of the detecting element 165 and the temperature signal of the sensor chip 150, and generates a correction signal for correcting the sensor error included in the temperature signal based on these signals. The error adjusting section 166 outputs the correction signal to the subsequent stage adjusting section 164.

The front-stage adjustment unit 163 is connected to the sensor element 151 of the sensor chip 150. The preceding-stage adjustment unit 163 is a circuit unit that adjusts the sensitivity of the temperature signal input from the sensor element 151. The rear stage adjusting unit 164 is connected to the output sides of the correction circuit unit 162 and the front stage adjusting unit 163. The subsequent-stage adjustment unit 164 is a circuit unit that performs offset adjustment of the temperature signal after sensitivity adjustment and corrects the sensor error based on the correction signal.

Specifically, as shown in fig. 3, the correction circuit unit 162 includes a DAC/ROM unit 167, a plurality of operational amplifiers 168, 169, 170, and 171, and a plurality of resistors 172, 173, 174, 175, 176, 177, and 178. These elements constitute a voltage follower, an amplifier circuit, and the like.

The DAC/ROM section 167 stores information such as a reference potential and a resistance value. The DAC/ROM unit 167 converts the stored information into an analog signal, and adjusts the reference potential of the operational amplifiers 169 and 170 and the resistance value of the resistor 177.

The correction circuit 162 adjusts the detection signal of the detection element 165 by the circuit configuration of the above-described elements. The detection signal is a signal whose signal value is proportional to the temperature. The correction circuit unit 162 functions to match the slope and the offset value of the signal value of the detection signal with those of the temperature signal. This is to prevent the temperature signal from being corrected in the case where there is no temperature difference between the sensor element 151 and the circuit chip 160.

The previous-stage adjustment unit 163 is a circuit unit that adjusts the sensitivity of the temperature signal. The front-stage adjustment unit 163 is a differential amplifier circuit unit having a resistor 179, an operational amplifier 180, and a sensitivity adjustment circuit unit 181. The previous-stage adjustment unit 163 corrects the sensitivity of the temperature signal in accordance with the sensitivity correction value stored in the sensitivity adjustment circuit unit 181 and outputs the corrected value.

The subsequent-stage adjustment unit 164 is a circuit unit that performs offset adjustment of the temperature signal. The subsequent stage adjustment unit 164 is a differential amplifier circuit unit having resistors 182 and 183, an operational amplifier 184, and an offset adjustment circuit 185. The subsequent-stage adjustment unit 164 corrects the offset of the temperature signal after the sensitivity adjustment according to the offset correction value stored in the offset adjustment circuit unit 185 and outputs the corrected offset. The above is the overall structure of the sensor device 100.

Next, a case where the sensor error is included in the temperature signal will be described. As shown in fig. 4, there are a plurality of paths through which heat of the outside air temperature reaches the measurement target in the pipe 200.

The 1 st path 101 is a path through which heat of the outside air temperature reaches the measurement target in the pipe 200 via the casing 110 and the pipe 200. The 2 nd path 102 is a path through which heat of the outside air temperature reaches the measurement target in the pipe 200 via the case 110 and the measurement target located in the medium introduction hole 114. The 3 rd path 103 is a path through which heat of the outside air reaches the measurement object in the pipe 200 via the molding resin portion 120, the molding resin portion 140, and the measurement object positioned in the medium introduction hole 114.

The 4 th path 104 is a path from the molding resin portion 120, the molding resin portion 140, the circuit chip 160, the lead frame 143, the sensor chip 150, and the measurement object positioned in the medium introduction hole 114 to the measurement object in the pipe 200.

The inventors of the present disclosure focused on the heat flux flowing through the 4 th path 104 toward the circuit chip 160 → the lead frame 143 → the sensor chip 150 → the measurement object positioned in the medium introduction hole 114 → the measurement object in the pipe 200. The temperature of the sensor chip 150 is the same as the temperature of the sensor element 151. Accordingly, the temperature of the sensor chip 150 is hereinafter referred to as the temperature of the sensor element 151.

The heat flux causes a temperature difference between the measurement target in the pipe 200 and the sensor element 151. Therefore, a sensor error is included in the temperature measured by the sensor element 151. The sensor error is a component caused by a temperature difference between the measurement target in the pipe 200 and the sensor element 151. Further, a temperature difference occurs between the circuit chip 160 and the sensor element 151.

The inventors of the present disclosure have found that there is a correlation between the temperature difference between the circuit chip 160 and the sensor element 151 and the temperature difference between the sensor element 151 and the measurement target in the pipe 200 based on the occurrence of the temperature difference.

Specifically, as shown in fig. 5, the temperature difference between the sensor element 151 and the measurement target in the pipe 200 increases in response to an increase in the temperature difference between the circuit chip 160 and the sensor element 151. That is, the sensor error increases at a certain rate of increase with respect to the temperature difference between the circuit chip 160 and the sensor element 151. In other words, when a sensor error is included in the temperature signal, a temperature difference between the sensor element 151 and the circuit chip 160 corresponding to the sensor error occurs.

The inventors of the present disclosure can correct the sensor error included in the temperature signal based on the temperature difference between the circuit chip 160 and the sensor element 151 in consideration of the correlation described above. Thus, in the present embodiment, the sensor device 100 has the configuration shown in fig. 1 to 3.

Next, a method of correcting a sensor error included in the temperature signal will be described. First, the sensor chip 150 outputs a bridge voltage of the sensor element 151 as a temperature signal. The temperature signal may contain a sensor error.

The circuit chip 160 receives a temperature signal from the sensor chip 150, and the temperature signal is input to the correction circuit 162 and the previous stage adjustment 163. The front-stage adjustment unit 163 corrects the sensitivity of the temperature signal in accordance with the sensitivity correction value stored in the sensitivity adjustment circuit unit 181, and outputs the temperature signal after the sensitivity correction to the rear-stage adjustment unit 164.

The detection element 165 of the correction circuit unit 162 detects the temperature of the circuit chip 160 and acquires a detection signal. The error adjusting unit 166 of the correction circuit unit 162 generates an error correction value for correcting the sensor error included in the temperature signal based on the temperature signal and the detection signal.

Therefore, the error adjustment unit 166 matches the constant increase rate and offset value of the signal value of the detection signal with respect to the temperature and the constant increase rate and offset value of the signal value of the temperature signal with respect to the temperature by a circuit centered on the operational amplifiers 169 and 170. This prevents the temperature signal from being corrected without causing a temperature difference between the circuit chip 160 and the sensor element 151.

Next, the error adjusting unit 166 generates an error correction value that decreases at a constant rate of decrease that is the same as the constant rate of increase of the signal value of the detection signal with respect to the temperature difference between the temperature of the detection signal and the temperature of the temperature signal, by a circuit centered on the operational amplifier 171.

As shown in fig. 6, the error correction value decreases at a constant rate of decrease with respect to the temperature difference between the circuit chip 160 and the sensor element 151. The slope of the error correction value is a value obtained by inverting the polarity of the slope of the detection signal, that is, the slope of the temperature signal. The correction circuit section 162 outputs a signal corresponding to the error correction value to the subsequent stage adjustment section 164.

The subsequent stage adjusting section 164 corrects the sensitivity of the temperature signal in accordance with the offset correction value stored in the offset adjusting circuit section 185. The subsequent-stage adjustment unit 164 adds an error correction value to the temperature signal to correct the sensor error included in the temperature signal.

As shown in fig. 7, by adding the error correction value to the temperature signal, the sensor error with respect to the temperature difference between the circuit chip 160 and the sensor element 151 is cancelled out. Thus, when the sensor error is included in the temperature signal, the temperature signal is corrected by the error correction value.

On the other hand, in the case where the sensor error is not included in the temperature signal, there is no temperature difference between the circuit chip 160 and the sensor element 151. In this case, the sensor error shown in fig. 5 is zero. Accordingly, the error correction value shown in fig. 6 is zero. Thus, the subsequent-stage adjustment unit 164 adds an error correction value of zero to the temperature signal. This prevents the temperature signal from being corrected even though the temperature difference between the circuit chip 160 and the sensor element 151 does not occur.

In this way, the circuit chip 160 corrects the temperature signal based on the temperature difference between the temperature of the circuit chip 160 detected by the detection element 165 and the temperature of the measurement object detected by the sensor element 151. The circuit chip 160 outputs the corrected temperature signal to the outside.

As described above, by utilizing the correlation between the temperature difference between the circuit chip 160 and the sensor element 151 and the sensor error, the sensor error included in the temperature signal can be corrected based on the temperature difference. Therefore, a sensor error due to a temperature difference between the measurement target and the sensor element 151 can be reduced.

That is, the temperature of the measurement target can be measured in a situation where a temperature difference is likely to occur in the circuit chip 160, the sensor element 151, the medium introduction hole 114, and the pipe 200. In this case, the sensor chip 150 is disposed not at the center of the pipe 200 but at a position corresponding to the thick portion 201, but the temperature difference between the portions is used, so that the temperature of the measurement target can be measured. The method is particularly suitable for measurement when the temperature of the measurement object is ultra-high temperature or ultra-low temperature, or when the measurement object is a special object such as strong acid.

For example, a sensor error may occur due to the influence of the outside air temperature. This is the case where heat of the outside air temperature is transmitted to the sensor element 151 through the 2 nd path 102 and the 3 rd path 103 shown in fig. 4. In this case, as shown in fig. 8, the sensor error increases as the temperature difference between the outside air temperature and the temperature of the measurement target increases. However, the circuit chip 160 generates an error correction value and corrects the temperature signal with the error correction value, thereby making the sensor error substantially zero.

Further, a sensor error may occur due to the influence of heat generated by the circuit chip 160. This is the case where heat of the circuit chip 160 is transferred to the sensor element 151 via the lead frame 143 through the 4 th path 104 shown in fig. 4. In this case, as shown in fig. 9, when power is applied to the circuit chip 160, the sensor error increases as the temperature of the circuit chip 160 increases. Since the circuit chip 160 is formed of a semiconductor device, the influence of heat generation is large. If a certain amount of time elapses after the power is applied to the circuit chip 160, the temperature of the circuit chip 160 becomes a constant value, and therefore the sensor error also becomes a constant value.

In such a case, since the generation of the error correction value is started immediately after the power supply is applied to the circuit chip 160, the sensor error can be corrected immediately after the power supply is applied to the circuit chip 160. This makes it possible to substantially zero the sensor error regardless of the heat generation of the circuit chip 160.

Further, as shown in fig. 10, the flow velocity of the measurement target flowing into the pipe 200 is slower on the inner side than on the outer side of the casing 110. Therefore, a sensor error due to a response delay of the sensor element 151 with respect to the measurement object may occur. In this case, since it takes time until the measurement target reaches the temperature detection portion of the sensor chip 150, a temperature difference occurs between the temperature of the measurement target in the pipe 200 and the temperature at the time of measurement at the transition time when the measurement target starts to flow as shown in fig. 11. That is, the temperature detected by the sensor element 151 is lower than the temperature of the measurement target in the pipe 200.

In this case, the circuit chip 160 corrects the temperature signal based on the error correction value, and can acquire the temperature of the measurement target in the pipe 200. In particular, the accuracy of the measured temperature at the transition time when the measurement target starts to flow can be improved.

As a modification, for example, a thermistor may be used as an element for detecting the temperature of the measurement target.

As another modification, the circuit chip 160 may correct the sensor error by performing a process of adjusting the gain of the temperature signal or a process of weighting the temperature signal. The value of the gain or weighting is set with respect to the temperature difference between the circuit chip 160 and the sensor element 151. In this way, a correction method other than the method of adding the error correction value to the temperature signal may be adopted.

As another modification, the circuit chip 160 may have a function of estimating the outside air temperature of the environment in which the sensor device 100 is disposed. The circuit chip 160 acquires 3 temperatures, which are the temperature of the measurement object accurately obtained by correcting the temperature signal, the temperature of the sensor element 151 indicated by the temperature signal, and the temperature of the circuit chip 160 indicated by the detection element 165. And, the circuit chip 160 estimates the outside air temperature from the 3 temperatures.

The piezoresistive element 152 in this embodiment corresponds to a resistive element.

(embodiment 2)

In this embodiment, a portion different from embodiment 1 will be described. In the present embodiment, the sensor element 151 detects the pressure of the measurement target. Therefore, the sensor chip 150 has a diaphragm not shown.

For example, the sensor chip 150 is formed of a 5-layer laminated substrate. For example, the SOI substrate is composed of the 1 st, 2 nd and 3 rd layers, and the cap substrate is composed of the 4 th and 5 th layers. The 2 nd and 3 rd layers are thin-walled membranes. The 3 rd layer is a semiconductor layer of, for example, silicon, and a plurality of piezoresistive elements 152 are formed.

The 4 th and 5 th layers have a partially recessed recess corresponding to the sensing region of the diaphragm. The recessed portion is formed by stacking the 3 rd, 4 th and 5 th layers to form a sealed space. The space is, for example, a vacuum chamber. Thus, the pressure measured by the sensor chip 150 is an absolute pressure.

The piezo-resistive element 152 is used to detect both temperature and pressure. As described above, since the piezo-resistive elements 152 constitute a wheatstone bridge circuit, a change in the resistance of the piezo-resistive elements 152 and a change in the midpoint voltage of the wheatstone bridge circuit, which correspond to the strain of the diaphragm, are output as pressure signals. The piezo-resistive elements 152 may be formed on the sensor chip 150 for temperature detection and pressure detection, respectively.

The circuit chip 160 receives the pressure signal from the sensor chip 150, and corrects the pressure value of the measurement target based on the corrected temperature signal. Since the resistance value of the piezo-resistive element 152 changes in accordance with the temperature, the accuracy of the pressure value can be improved by correcting the pressure value with respect to the temperature. Thereby, the sensor device 100 can output the pressure value after the temperature correction to the outside.

As a modification, the sensor chip 150 may detect at least any one of 1 of the flow rate, viscosity, humidity, and acceleration of the measurement target in addition to the pressure as the physical quantity different from the temperature of the measurement target. That is, the sensor chip 150 includes a sensing unit for detecting a flow rate, viscosity, humidity, and acceleration, in addition to a temperature detection unit. The circuit chip 160 corrects a physical quantity different from the temperature of the measurement object based on the corrected temperature signal.

The present disclosure is not limited to the above-described embodiments, and various modifications can be made as follows without departing from the scope of the present disclosure.

For example, the object to which the sensor device 100 is attached is not limited to the pipe 200, and may be fixed to an object to which a container or the like is attached. In this case, the sensor device 100 detects the temperature of the measurement object in the container.

The electrical connection parts of the circuit chip 160 and the sensor chip 150 are not limited to the lead frame 143. For example, the circuit chip 160 and the sensor chip 150 may be mounted on a printed board.

The present disclosure has been described in terms of embodiments, but it should be understood that the present disclosure is not limited to the embodiments or constructions. The present disclosure also includes various modifications and variations within an equivalent range. In addition, various combinations and forms, and further, other combinations and forms including only one element, more than one element, or less than one element are also within the scope or spirit of the present disclosure.