JP2005308689A - Physical quantity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor having more stable output characteristics as compared with conventional types with respect to the temperature changes in the environment where the sensor is used. <P>SOLUTION: In the physical quantity sensor having a printed circuit board 1, a sensor section 2 that is packaged on the printed circuit board 1 and includes a sensor device in a package 2b, and a case 4 for covering the printed circuit board 1 and the sensor section 2, the structure of the physical quantity sensor is set to the structure, in which a heater 3 is directly wound around the package 2b of the sensor section 2. Then, even if the environmental temperature of sensor usage is changed, the sensor device is heated by the heater 3, when the sensor section 2 is operated so that the temperature of the sensor device reaches a prescribed temperature range. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a physical quantity sensor, and more particularly to a physical quantity sensor for vehicle control.

  Examples of the vehicle control physical quantity sensor include a vehicle control angular velocity sensor used for vehicle control and a vehicle control acceleration sensor. These sensors have a structure in which, for example, a sensor device which is an actual physical quantity detection unit is mounted on a printed circuit board and is covered with a case. Hereinafter, these physical quantity sensors are simply referred to as sensors.

  The sensor usually has a property (output temperature characteristic) in which the magnitude of the output (voltage value) changes when the temperature of the sensor device that is the actual detection unit changes. Therefore, conventionally, in addition to the sensor device, a temperature sensor unit and a memory such as an EEPROM in which correction values are stored in advance are mounted on the printed circuit board, and the sensor is used in accordance with the temperature detected by the temperature sensor. By adding a correction value to the output value of the device and electrically correcting the output of the sensor device, the temperature characteristic of the output of the sensor device has been dealt with.

  However, even with the above countermeasures, the output change due to the temperature change before correction of the sensor device is non-linear or abrupt (large), or the temperature sensor detection temperature interval is rough. In some cases, the output of the sensor device cannot be completely corrected due to the fact that the output change of the sensor is unstable. That is, even a sensor dealt with by the above method has some temperature characteristics.

  For this reason, in the conventional sensor, when the temperature change of the use environment is large, the output of the sensor device is affected by the temperature characteristics, and thus there is a problem that the output accuracy is deteriorated. Such a problem is not limited to the above-described physical quantity sensor for vehicle control, and is a problem that occurs even for sensors that are used in other technical fields and have output temperature characteristics. In addition, since the vehicle control physical quantity sensor generally has a large temperature change in the mounting environment and requires a high-accuracy output, such a problem becomes particularly significant.

  In view of the above points, an object of the present invention is to provide a sensor having an output characteristic that is more stable than the conventional technique with respect to a temperature change in an environment in which the sensor is used.

  In order to achieve the above object, according to the first aspect of the present invention, the holding means is disposed in the case (4) and holds the temperature of the sensor device (2a, 11) in a predetermined temperature range narrower than the operating environment temperature range. (3, 13).

  Thereby, even if it is a case where a temperature change arises in the usage environment of a physical quantity sensor, it can suppress that the temperature of sensor device itself changes by the influence of the temperature change of an environment. As a result, it is possible to provide a physical quantity sensor having stable output characteristics with respect to temperature changes in the surrounding environment of the physical quantity sensor.

  In particular, when the present invention is applied to an angular velocity sensor or an acceleration sensor used for vehicle control that requires a large change in temperature of the mounting environment and requires a high-accuracy output, the present invention is more resistant to changes in mounting temperature than in the past. Thus, a vehicle control physical quantity sensor having stable output characteristics can be obtained.

  Further, according to the present invention, since the temperature change of the sensor device due to the environmental temperature change can be suppressed, a sensor device having a large temperature characteristic change can be used as a sensor for high-precision applications.

  As the holding means, for example, as shown in claim 2, when the sensor device (2a, 11) is operated, the sensor device (2a, 11) is set so that the sensor device (2a, 11) is in a predetermined temperature range. Heating / cooling means (3, 11) for heating or cooling can be used.

  Further, as shown in claim 3, in addition to the heating / cooling means, a heat insulating member that covers the sensor devices (2a, 11) and the heating / cooling means (3, 11) can be used as the holding means. Thereby, it becomes easy to keep the temperature of the sensor device within a certain range.

  In addition, regarding the location of the heating / cooling means, as shown in claim 4, the heating / cooling means may be arranged so as to directly cover the packages (2b, 14) containing the sensor devices (2a, 11). it can.

  In addition, as shown in claim 5, when the sensor device is constituted by an IC chip (11) and the Peltier effect element (13) is used as the heating and cooling means, the IC chip (11) is accommodated. A Peltier effect element can also be arranged in the package (14). For example, the Peltier effect element can be arranged below, next to, or above the IC chip.

  In this case, since the IC chip has a small volume, when the IC chip is held in a predetermined temperature range, less heat is supplied to the IC chip or taken away from the IC chip. It becomes easy to hold in a predetermined temperature range.

  For the same reason, according to the present invention, the power consumption of the heating / cooling means can be reduced as compared with the case where a sensor device other than an IC chip is used.

  Further, as the heating and cooling means, as shown in claim 6, heating means (3, 11) for heating the sensor device (2a, 11) so that the temperature of the sensor device (2a, 11) is equal to or higher than the upper limit temperature of the use environment temperature range. Is preferably used.

  Thus, in the case where the temperature of the sensor device (2a, 11) is maintained at a temperature equal to or higher than the upper limit temperature of the operating environment temperature range, the sensor device does not need to be cooled but is only heated. As compared with the case where what performs both heating and cooling is used, the structure of a heating-cooling means can be simplified.

  For example, if the operating environment temperature is −35 ° C. to 85 ° C., a heater that can heat the sensor device can be used so that the temperature of the sensor device itself is 85 ° C. to 95 ° C.

  In addition, the code | symbol in the bracket | parenthesis of each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

(First embodiment)
FIG. 1 is an exploded perspective view of the physical quantity sensor according to the first embodiment of the present invention. In the present embodiment, a vehicle control yaw rate sensor will be described as an example.

  As shown in FIG. 1, the sensor according to the present embodiment includes a printed circuit board 1, a sensor unit 2 mounted on the printed circuit board 1, a heater 3, and a case 4. In addition, the point which has the heater 3 is a place where the sensor of this embodiment differs from the conventional sensor mainly.

  Although not shown, the printed circuit board 1 is mounted with a sensor unit 2, a power supply circuit that supplies power to the sensor unit 2, an amplifier circuit, and other elements necessary for obtaining a desired output from the sensor unit 2.

  The sensor unit 2 detects the yaw angular velocity of the vehicle. In the present embodiment, a general sensor unit 2 is used, and the sensor unit 2 has, for example, a structure in which a crystal 2a as a sensor device is included in a package 2b.

  Although not shown, the sensor according to the present embodiment also includes a temperature sensor and an EEPROM as in the conventional sensor, and the output of the sensor unit 2 is corrected.

  The heater 3 is for heating the sensor unit 2. This heater 3 corresponds to the holding means, heating / cooling means, and heating means of the present invention.

  For example, the heater 3 has a structure in which a heating wire is disposed in a sheet-like resin, and is directly wound around the surface of the package 2 b of the sensor unit 2.

  Although not shown, a power supply circuit that supplies power to the heater 3 and a control circuit (control unit) that controls the heater 3 are mounted on the printed circuit board 1. The heater 3 is supplied with power by the control circuit, for example, when the power is supplied to the sensor unit 2, and when the power supply to the sensor unit 2 is stopped, the heater 3 is supplied with power. Has also been stopped.

  Heating temperature of the heater 3 is set so that the sensor unit 2 (crystal 2a) is in a predetermined temperature range. Specifically, since the environmental temperature at which the vehicle control yaw rate sensor is used is assumed to be −35 ° C. to 85 ° C., when the usage environmental temperature of the sensor changes from −35 ° C. to 85 ° C., The temperature of the heater 3 is set so that the temperature range of the sensor unit 2 is the temperature of 85 ° C. or more and is in a range of 85 ° C. to 95 ° C. which is a temperature range narrower than the use environment temperature range. Yes. The range from 85 ° C. to 95 ° C. corresponds to the predetermined temperature range of the present invention, and 85 ° C. corresponds to the upper limit temperature of the use environment temperature range of the present invention.

  As described above, the temperature range of the sensor unit 2 is set to a temperature higher than 85 ° C. If the temperature of the sensor unit 2 is set to a temperature range higher than the environmental temperature, only the heating by the heater 3 is performed. This is because the temperature of the sensor unit 2 can be easily managed.

  In the present embodiment, the heat generation temperature of the heater 3 is a constant temperature of 95 ° C., for example. Since the heater 3 is in contact with the sensor unit 2 and the distance from the sensor unit 2 is short, the temperature of the sensor device (crystal 2a) is 85 ° C. to 95 ° C. when the use environment temperature changes from −35 ° C. to 85 ° C. (Temperature around 90 ° C.).

  The case 4 is made of resin or metal and covers the printed circuit board 1 and the sensor unit 2 and the heater 3 mounted on the printed circuit board 1. And this case 4 is attached to a vehicle.

  In the sensor of the present embodiment configured as described above, when the power is supplied to the sensor unit 2 and the operation of the sensor unit 2 starts, the heater 3 is also supplied with power, so that the heater 3 For 2, start heating. If the sensor unit 2 is in operation, the heater 3 always heats the sensor unit 2. Thereby, the temperature of the sensor part 2 is hold | maintained in the range of 85 to 95 degreeC.

  On the other hand, when the power supply to the sensor unit 2 is stopped and the operation of the sensor unit 2 is stopped, the power supply to the heater 3 is also stopped, and the heater 3 stops heating the sensor unit 2.

  Next, main features of the sensor of this embodiment will be described.

  FIG. 2B shows an example of output characteristics with respect to environmental temperature changes in the sensor of this embodiment, and FIG. 2A shows output characteristics with respect to environmental temperature changes of the sensor of FIG. An example is shown. In addition, the curve shown with the broken line in Fig.2 (a) is an output value before correct | amending using a temperature sensor and EEPROM, and the curve shown as a continuous line is an output value after correction | amendment.

  In a sensor that does not have the heater 3 (conventional sensor), a change in ambient temperature of the sensor is a change in temperature of the sensor device. That is, in the sensor not having the heater 3, when the environmental temperature changes between −35 ° C. and 85 ° C., the temperature of the sensor device also changes between −35 ° C. and 85 ° C.

  For this reason, as can be seen from FIG. 2A, even if the output of the sensor device is corrected as in the prior art, temperature characteristics are produced in the output of the sensor device. For this reason, for example, a difference (ΔV2 in FIG. 2A) occurs in the magnitude of the output of the sensor device between when the temperature of the sensor device is low and when the temperature is high.

  On the other hand, in the sensor of the present embodiment, the heater 3 is directly wound around the package 2b of the sensor unit 2. For this reason, the heat supplied from the heater 3 is a main factor for determining the temperature of the sensor unit 2, and even if the sensor's operating environment temperature is −30 ° C. to 85 ° C., the temperature of the sensor unit 2, The temperature of the sensor device is always maintained at a temperature within 85 ° C to 95 ° C.

  Therefore, as shown in FIG. 2B, the output characteristics of the sensor of the present embodiment include the heater 3 shown in FIG. 2A even when the sensor's operating environment temperature is −30 ° C. to 85 ° C. It becomes the same as the output characteristic in 85 to 95 degreeC of the sensor which is not.

  In general, the wider the range in which the temperature of the sensor device changes, the greater the difference in output between low and high temperatures. Therefore, in the sensor of this embodiment, as can be seen from FIGS. 2A and 2B, the output difference ΔV1 of the sensor device between the maximum temperature and the minimum temperature of the sensor use environment temperature (see FIG. 2B). However, it is smaller than the output difference ΔV2 (see FIG. 2A) of the sensor device between the maximum temperature and the minimum temperature of the use environment temperature in the sensor not having the heater 3. In other words, the output accuracy of the sensor of the present embodiment is improved as compared with a sensor that does not have the heater 3.

  Thus, according to the present embodiment, even if a temperature change occurs in the environment in which the sensor is used, the temperature change of the sensor device can be suppressed as compared with the conventional sensor. On the other hand, it is possible to provide a sensor having output characteristics that are more stable than conventional ones.

  In this embodiment, the case where the temperature range of the sensor device is held within 85 ° C. to 95 ° C. has been described. However, the temperature range is narrower than the use environment temperature range of the sensor and is higher than the upper limit temperature of the use environment temperature. If it is temperature, the temperature range of a sensor device can be made into another temperature range. At this time, as the temperature range in which the sensor device is held is narrower, a sensor having stable output characteristics with respect to changes in the use environment temperature can be obtained.

  Further, as described above, the sensor according to the present embodiment is provided with a heater 3 for a sensor whose output characteristics are corrected using, for example, a temperature sensor and an EEPROM, so that the output accuracy is improved. In addition to improving the accuracy of output, the following effects are also obtained.

  FIG. 3B shows another example of output characteristics with respect to environmental temperature changes in the sensor of the present embodiment. FIG. 3A shows the sensor of FIG. The other example of an output characteristic is shown.

  According to the present embodiment, as shown in FIG. 3 (a), since the sensor output in the vicinity of −30 ° C. does not fall within the standard range, a sensor device that could not be used at −30 ° C. to 85 ° C. It can be used even in an environment of -30 ° C to 85 ° C.

  This is because, in a conventional sensor, the output of the sensor device is out of the standard range, as shown in FIG. 3A, when the operating environment temperature is −30 ° C. to 85 ° C. When the temperature is as low as −30 ° C., and when the temperature is as high as 85 ° C. to 95 ° C., the output value is within the standard range.

  Therefore, in the present embodiment, even when the environmental temperature of the sensor is −30 ° C. to 85 ° C., the sensor unit 2 is brought into the range of 85 ° C. to 95 ° C. by the heater 3 when the sensor unit 2 is operated. Since they are held, as shown in FIG. 3B, the sensor output can be kept within the standard range.

  Thus, in this embodiment, the temperature of the sensor device is a temperature range narrower than the environmental temperature range such as 85 ° C. to 95 ° C. by the heater 3, and the output value of the sensor device falls within the standard range. The temperature is maintained. Thereby, according to this embodiment, even if it is a sensor device which could not be used in an application with a wide environmental temperature range such as −30 ° C. to 85 ° C., the environmental temperature range is wide and high-accuracy output is achieved. It can be used as a sensor for required applications.

  Moreover, the sensor of this embodiment also has the following effects.

  As described in the background art section, when the temperature sensor and the EEPROM are used to correct the output of the sensor device according to the temperature change, in actual sensor production, the temperature of the environment in which the sensor is used Changes had to be reproduced on the bench and correction values had to be set for each sensor.

  Furthermore, in the production of sensors that have a wide range of operating environment temperatures, it was necessary to reproduce a wide range of temperatures. For these reasons, conventional sensors have poor productivity.

  On the other hand, in the sensor of this embodiment, even when the use environment temperature of the sensor is −30 ° C. to 85 ° C., the sensor unit 2 is moved from 85 ° C. to 85 ° C. by the heater 3 when the sensor unit 2 is operated. The temperature is maintained in the range of 95 ° C.

  Thus, in this embodiment, since the temperature of the sensor device is set to a temperature range narrower than the environmental temperature range, the influence of temperature characteristics on the output of the sensor device is suppressed more than before.

  Therefore, according to the present embodiment, since the influence of the temperature characteristic is small, a sensor having a high-accuracy output can be obtained without setting the correction value strictly. For this reason, according to the present embodiment, in the sensor production, the correction value is conventionally set for each sensor device, but the same correction value can be set for a plurality of sensor devices.

  Further, in setting the correction value in the production of the sensor, it is only necessary to reproduce only the temperature range of 85 ° C. to 95 ° C. Therefore, according to the present embodiment, as in the conventional case, −35 ° C. to 85 ° C. The productivity of the sensor can be improved compared with the case where the environmental temperature change is reproduced on the bench.

  In the conventional sensor, in order to inspect the output characteristics from -35 ° C to 85 ° C in sensor production, it is necessary to reproduce a low temperature such as -35 ° C or a high temperature such as 85 ° C. It was. When reproducing a low temperature such as −35 ° C., it was necessary to use a cooling compressor.

  On the other hand, in this embodiment, it is only necessary to reproduce 85 ° C. to 95 ° C., which is higher than room temperature, in the production of the sensor, so there is no need to use a cooling compressor, and there is an apparatus for heating. What is necessary is that the facilities required for production can be simplified as compared with the prior art.

  In the present embodiment, the case where the heater 3 is directly wound around the package 2b of the sensor unit 2, that is, the case where the heater 3 is disposed so as to directly cover the package 2b has been described as an example. The heater 3 may be arranged at other positions as long as the sensor device 2 can be heated in the case 4 without being directly wound around the package 2b.

  For example, the heater 3 can be arranged next to the sensor unit 2 so as not to contact the sensor unit 2. In this case, for example, the temperature of the heater 3 is set to 100 ° C. Thus, when the sensor unit 2 and the heater 3 are not in contact with each other, according to the distance between the sensor unit 2 and the heater 3 so that the temperature of the sensor unit 2 is maintained within a range of 85 ° C. to 95 ° C. Then, the temperature of the heater 3 is set.

  Regarding the arrangement of the heater 3, the greater the distance between the heater 3 and the sensor unit 2, the greater the heat loss, so that the heat loss from the heater 3 is reduced so as to be in contact with the sensor unit 2. It is preferable to arrange the heater 3.

(Second Embodiment)
In the first embodiment, the case where the sensor unit 2 has a structure having the crystal 2a in the package 2b has been described as an example. However, in the present embodiment, as the sensor unit 2, a sensor device is configured by a semiconductor chip. A case of using the above will be described.

  In FIG. 4, the perspective view of the sensor part 2 in 2nd Embodiment of this invention is shown. In FIG. 4, the ceramic package and a part of the lid are omitted so that the inside of the sensor unit 2 can be seen.

  The sensor unit 2 of the present embodiment is disposed between a semiconductor chip (sensor chip) 11 as a sensor device, a circuit chip 12 disposed below the sensor chip 11, and the sensor chip 11 and the circuit chip 12. The Peltier effect element 13 and the ceramic package 14 covering these elements are provided.

The sensor chip 11 detects the angular velocity of the vehicle and has a general structure. As the sensor chip 11, for example, a sensor chip having a comb-like fixed electrode and a movable electrode and detecting an angular velocity by a change in capacitance between the fixed electrode and the movable electrode can be used. . The area of the sensor chip 11 is 3 mm ² , for example.

  The circuit chip 12 is a circuit that processes a signal transmitted to and from the sensor chip 11, and is electrically connected to the sensor chip 11 by a bonding wire 15a.

  The Peltier effect element 13 is sandwiched between the sensor chip 11 and the circuit chip 12 and is in contact with the bottom surface of the sensor chip 11. The Peltier effect element 13 is a thermoelectric element that generates heat or absorbs heat when supplied with current. This Peltier effect element 13 corresponds to the holding means, heating / cooling means, and heating means of the present invention.

  The Peltier effect element 13 is electrically connected to the circuit chip 12 via the bonding wire 15b, and the circuit chip 12 controls the heat generation temperature of the Peltier effect element 13.

  In the Peltier effect element 13, as in the first embodiment, when the sensor operating environment temperature is −35 ° C. to 85 ° C., the temperature of the sensor chip 11 is 85 ° C. to 95 ° C. during operation of the sensor chip 11. The sensor chip 11 is heated so as to be in the range of ° C. In the present embodiment, the heat generation temperature of the Peltier effect element 13 is set to 95 ° C., for example.

  The sensor chip 11, the circuit chip 12, and the Peltier effect element 13 are disposed inside the ceramic package 14, and the sensor chip 11 and the circuit chip are formed by the ceramic package 14 and a lid 14b disposed on the upper side of the ceramic package 14. 12 and the Peltier effect element 13 are sealed.

  Further, inside the ceramic package 14, a wiring terminal portion 14a for connecting the sensor chip 11, the circuit chip 12, and the Peltier effect element 13 to an external power source is provided. The wiring terminal portion 14a and the bonding pads in the sensor chip 11, the circuit chip 12, and the Peltier effect element 13 are connected by bonding wires 15c, 15d, and 15e.

  The sensor of the present embodiment has a structure in which the sensor unit 2 configured as described above is mounted on the printed circuit board 1 and covered with a case 4 as in the first embodiment.

  As described above, also in the sensor of this embodiment, when the use environment temperature of the sensor is −35 ° C. to 85 ° C., the Peltier effect element is set so that the temperature of the sensor chip 11 is in the range of 85 ° C. to 95 ° C. 13, the sensor chip 11 is heated. Therefore, according to this embodiment, the same effect as that of the first embodiment can be obtained.

The sensor chip 11 used in this embodiment has an area of 3 mm ² and a small area and volume. Therefore, when the sensor chip 11 is held in the temperature range of 85 ° C. to 95 ° C., the sensor chip 11 is The amount of heat required for supply is small compared to the case where the sensor device is configured by the crystal 2a as in the first embodiment.

  For this reason, the sensor of this embodiment can hold | maintain the temperature of the sensor chip 11 at 85 to 95 degreeC easily than the sensor of 1st Embodiment. Moreover, according to this embodiment, the power consumption of a heating / cooling means can also be reduced compared with the case where the crystal 2a is used as a sensor device.

  In the present embodiment, the case where the Peltier effect element 13 is disposed below the sensor chip 11 has been described as an example. However, any other position can be used as long as the sensor chip 11 can be heated within the ceramic package 14. The Peltier effect element 13 can also be arranged at the position.

  For example, the Peltier effect element 13 can be arranged on the lateral side or the upper side of the sensor chip 11. However, when the upper Peltier effect element 13 of the sensor chip 11 is disposed, the Peltier effect element 13 is disposed and fixed to the sensor chip 11 so that the movable electrode of the sensor chip 11 is not suppressed.

(Third embodiment)
In the first and second embodiments, the structure of the sensor has been described as an example in which the heater 3 and the Peltier effect element 13 are arranged in the vicinity of the sensor device. However, around these, a foamed polystyrene or the like is further provided. It can also be set as the structure which has arrange | positioned the heat insulation member. This heat insulating member corresponds to the holding means of the present invention.

  Thereby, since the influence which a sensor device receives from an external temperature change can be suppressed, compared with the sensor of 1st, 2nd embodiment, the temperature of a sensor device can be stabilized.

In the present embodiment, as a means for maintaining the temperature of the sensor device at 85 ° C. to 95 ° C., the case where the heater 3 or the Peltier effect element 13 and the heat insulating member are used together has been described as an example, but only the heat insulating member is used. It can also be used. Even in this case, the temperature range of the sensor device can be maintained in a temperature range narrower than the operating environment temperature range of the sensor.
(Other embodiments)
(1) In the first embodiment, the case where the heater 3 is used as the holding unit has been described as an example. However, in the sensor of the first embodiment, a Peltier effect element is used instead of the heater 3 as in the second embodiment. You can also Similarly, in the sensor of the second embodiment, the heater 3 can be used instead of the Peltier effect element 13, and the heater 3 can be directly wound around the surface of the ceramic package 14 as in the first embodiment.

  (2) In each of the above embodiments, the case where the heat generation temperature of the heater 3 and the Peltier effect element 13 is set to a constant temperature such as 95 ° C. has been described as an example. It can also be changed according to the environmental temperature.

  In this case, the heating temperature of the heater 3 and the Peltier effect element 13 is controlled by the circuit for controlling the heater 3 and the circuit chip 12 for controlling the Peltier effect element 13 according to the temperature detected by the temperature sensor. In this way, the temperature of the sensor device can be kept within a predetermined temperature range.

  (3) In each of the above-described embodiments, the case where the heat generation temperature of the heater 3 or the Peltier effect element 13 is set so that the temperature of the sensor device is higher than the use environment temperature range of the sensor will be described as an example. However, the temperature of the sensor device can be maintained in another temperature range. In the case where the temperature of the sensor device is set to a temperature range lower than the maximum temperature of the sensor use environment temperature, the Peltier effect element 13 is used as the heating and cooling means as described in the second embodiment.

  For example, if the use environment temperature range of the sensor is −30 ° C. to 85 ° C., the temperature of the sensor device can be held near 30 ° C. by the Peltier effect element 13. At this time, when the use environment temperature exceeds 30 ° C., the sensor device is cooled by the Peltier effect element 13, and when it is lower than 30 ° C., the sensor device is heated by the Peltier effect element 13, Control is performed by the circuit chip 12.

  (4) In each of the above embodiments, the vehicle control yaw rate sensor has been described as an example. However, the present invention is also applied to vehicle control physical quantity sensors such as acceleration sensors and pressure sensors, and physical quantity sensors in other technical fields. can do. That is, the present invention can be applied not only to the types of sensor devices such as the crystal 2a and semiconductors but also to all sensors having sensor devices having output temperature characteristics.

  In this case, since the use environment temperature varies depending on the type of sensor, the holding temperature of the sensor device is set in consideration of the use environment temperature.

It is a disassembled perspective view of the physical quantity sensor in 1st Embodiment of this invention. (A) is a figure which shows an example of the output characteristic with respect to the environmental temperature change of the sensor of the structure which does not have the heater 3 in the sensor of FIG. 1, (b) is an output with respect to the environmental temperature change of the sensor of FIG. It is a figure which shows an example of a characteristic. (A) is a figure which shows the other example of the output characteristic with respect to the environmental temperature change of the sensor of the structure which does not have the heater 3 in the sensor of FIG. 1, (b) is the environmental temperature change of the sensor of FIG. It is a figure which shows the other example of the output characteristic with respect to. It is a permeation | transmission perspective view of the sensor part in 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board, 2 ... Sensor part, 2a ... Package 2b, 3 ... Heater, 4 ... Case,
11 ... sensor chip, 12 ... circuit chip, 13 ... Peltier effect element,
14: Ceramic package.

Claims (6)

Sensor devices (2a, 11) mounted on the printed circuit board (1);
In the physical quantity sensor having a case (4) covering the printed circuit board (1) and the sensor device (2a, 11),
A physical quantity sensor arranged in the case (4) and provided with holding means (3, 13) for holding the temperature of the sensor device (2a, 11) in a predetermined temperature range narrower than the operating environment temperature range. . Heating / cooling that heats or cools the sensor device (2a, 11) as the holding means so that the sensor device (2a, 11) is in the predetermined temperature range when the sensor device (2a, 11) is operated. 2. The physical quantity sensor according to claim 1, wherein means (3, 11) are used. The heating / cooling means (3, 11) and a heat insulating member that covers the sensor devices (2a, 11) and the heating / cooling means (3, 11) are used as the holding means. Item 3. The physical quantity sensor according to Item 2. The sensor device (2a, 11) is mounted on the printed circuit board (1) in a state of being accommodated in a package (2b, 14), and the heating / cooling means (3) is the package (2b, 14). The physical quantity sensor according to claim 2, wherein the physical quantity sensor is disposed so as to directly cover the surface. An IC chip (11) is used as the sensor device, and the IC chip (11) is mounted on the printed circuit board (1) in a state of being housed in a package (14).
The physical quantity sensor according to claim 2 or 3, wherein a Peltier effect element (13) housed in the package (14) is used as the heating and cooling means. As the heating / cooling means, heating means (3, 11) for heating is used so that the temperature of the sensor device (2a, 11) is equal to or higher than the upper limit temperature of the use environment temperature range. The physical quantity sensor according to claim 2, wherein the physical quantity sensor is characterized in that:

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