Sensor chip and sensor device equipped therewith

Abstract

In a sensor chip having multiple sensing elements, when mounted on a sensor substrate, the difference in the influence of heat conduction from heat-generating materials between the multiple sensing elements is minimized. [Solution] The sensor chip 20 comprises sensing elements S1 and S2 and pad electrodes 271-274 and 281-284. Sensing element S1 is located in region A1 of the sensor chip 20, sensing element S2 is located in region A2 of the sensor chip 20, and the pad electrodes 271-274 and 281-284 are most numerous in region A3, which is sandwiched between regions A1 and A2 from the X direction.

Description

[[Technical Field]]

[0001] The present disclosure relates to a sensor chip and a sensor device including the same, and particularly relates to a sensor chip having a plurality of sensing elements and a sensor device including the same. [[Background Art]]

[0002] Patent Document 1 discloses a sensor chip having a plurality of sensing elements. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Patent No. 7070175 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] When a sensor device including a sensor substrate mounted with a sensor chip having a plurality of sensing elements is mounted on another product substrate, there may occur a large difference in the influence of heat conduction from a heat generating member mounted on the product substrate among the plurality of sensing elements.

[0005] In the present disclosure, a technique for reducing and suppressing the difference in the influence of heat conduction from a heat generating member among a plurality of sensing elements in a sensor chip having a plurality of sensing elements and a sensor device including the same is described. [[Means for Solving the Problem]]

[0006] A sensor chip according to one aspect of the present disclosure includes a first sensing element, a second sensing element, and a plurality of first pad electrodes, the first sensing element is arranged in a first region of the sensor chip, the second sensing element is arranged in a second region of the sensor chip, and the largest number of the plurality of first pad electrodes are arranged in a third region sandwiched from a first direction by the first region and the second region.

[0007] A sensor device according to one aspect of the present disclosure comprises a sensor substrate having a plurality of second pad electrodes, the sensor chip mounted on the sensor substrate, and a plurality of bonding wires, wherein each of the plurality of bonding wires electrically connects a corresponding one of the plurality of first pad electrodes to a corresponding one of the plurality of second pad electrodes. [Effects of the Invention]

[0008] According to this disclosure, a technology is provided for a sensor chip having multiple sensing elements and a sensor device equipped therewith, which suppresses the difference in the influence of heat conduction from a heat-generating member between multiple sensing elements. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic plan view showing the configuration of a sensor device 100 according to a first embodiment of the technology described herein. [Figure 2] Figure 2 is a schematic cross-sectional view of the sensor device 100. [Figure 3] Figure 3 is a circuit diagram of the gas sensor 50 using the sensor device 100. [Figure 4] Figure 4 is a schematic plan view showing the configuration of the sensor device 100A according to the first modified example. [Figure 5] Figure 5 is a schematic plan view showing the configuration of the sensor device 100B according to the second modified example. [Figure 6] Figure 6 is a schematic plan view showing the configuration of the sensor device 100C according to the third modified example. [Figure 7] Figure 7 is a schematic plan view showing the configuration of the sensor device 100D according to the fourth modified example. [Figure 8] Figure 8 is a schematic plan view showing the configuration of a sensor device 200 according to a second embodiment of the technology described herein. [Figure 9] Figure 9 is a schematic plan view showing the configuration of the sensor device 200A according to the fifth modified example. [Figure 10]Figure 10 is a schematic plan view showing the configuration of the sensor device 200B according to the sixth modified example. [Figure 11] Figure 11 is a circuit diagram of the sensor device 200B. [Figure 12] Figure 12 is a schematic plan view showing the configuration of a sensor device 300 according to a third embodiment of the technology described herein. [Figure 13] Figure 13 is a schematic plan view showing the configuration of a sensor device 400 according to a fourth embodiment of the technology described herein. [Figure 14] Figure 14 is a schematic diagram illustrating the positional relationship between the sensing elements S1-S3 and the pad electrodes 271-274, 281-284, 294, and 295. [Figure 15] Figure 15 is a schematic plan view showing the configuration of a sensor device 500 according to a fifth embodiment of the technology described herein. [Modes for carrying out the invention]

[0010] The embodiments of the technology described herein will be described in detail below with reference to the attached drawings.

[0011] Figure 1 is a schematic plan view showing the configuration of a sensor device 100 according to a first embodiment of the technology described herein. Figure 2 is a schematic cross-sectional view of the sensor device 100.

[0012] As shown in Figures 1 and 2, the sensor device 100 according to the first embodiment comprises a sensor substrate 10 and a sensor chip 20 mounted on the sensor substrate 10. The sensor substrate 10 has a main surface 11 that constitutes the XY plane, and the sensor chip 20 is mounted on the main surface 11. Other electronic components may be further mounted on the sensor substrate 10. In the example shown in Figures 1 and 2, the sensor device 100 is mounted on the mounting surface 71 of the product substrate 70. Not only the sensor device 100, but also electronic components 30 are mounted on the mounting surface 71 of the product substrate 70. The electronic components 30 are heat-generating members that generate heat through their operation. In this embodiment, in a plan view from the Z direction, the electronic components 30 are located on the -X direction side of the sensor device 100.

[0013] The sensor chip 20 includes two sensing elements S1 and S2. Although not particularly limited, the sensor chip 20 is, for example, a heat conduction type gas sensor chip for detecting the concentration of CO₂ gas in a measurement atmosphere. The sensor chip 20 outputs a signal based on the state of the sensing element S1 and the state of the sensing element S2. The signal output by the sensor chip 20 is, for example, a signal indicating the concentration of CO₂ gas in the measurement atmosphere. In the case of the present embodiment, the sensing element S1 is a temperature-sensitive element for detection, and the sensing element S2 is a temperature-sensitive element for reference. The sensor chip 20 includes: a base material 21 having a thickness direction in the Z direction; an insulating film 22 covering a surface 214 on the +Z direction side of the base material 21; heaters MH1 and MH2 provided on the insulating film 22; an insulating film 23 covering the heaters MH1 and MH2; a pair of thermistor electrodes 251 and 252 provided on the insulating film 23 so as to overlap with the heater MH1 in a plan view viewed from the Z direction; a pair of thermistor electrodes 261 and 262 provided on the insulating film 23 so as to overlap with the heater MH2 in a plan view viewed from the Z direction; a thermistor resistor 253 covering the pair of thermistor electrodes 251 and 252; a thermistor resistor 263 covering the pair of thermistor electrodes 261 and 262; an insulating film 24 covering the thermistor electrodes 251, 252, 261, 262 and the thermistor resistors 253, 263; and a plurality of pad electrodes 271 to 274, 281 to 284 provided on the insulating film 24.

[0014] The pair of thermistor electrodes 251, 252 and the thermistor resistor 253 constitute the sensing element S1. The pair of thermistor electrodes 261, 262 and the thermistor resistor 263 constitute the sensing element S2. The sensing element S1 and the sensing element S2 are arranged in the X direction (the first direction). When viewed from the center of the sensor chip 20, the sensing element S1 is located on the -X direction side, and the sensing element S2 is located on the +X direction side. The sensing element S1 is located closer to the electronic component 30 than the sensing element S2 is.

[0015] The base material 21 is not particularly limited as long as it has appropriate mechanical strength and is made of a material suitable for microfabrication such as etching, and a silicon substrate, a sapphire substrate, a ceramic substrate, a quartz substrate, a glass substrate, or the like can be used. In order to improve the thermal efficiency of the heaters MH1 and MH2, cavities 211 and 212 are respectively provided in the base material 21 at positions overlapping with the heaters MH1 and MH2 in a plan view viewed from the Z direction. In the region where the cavity 211 is provided, the thickness of the base material 21 is locally reduced, or the base material 21 is removed. In the example shown in FIGS. 1 and 2, the base material 21 is removed in the cavities 211 and 212, and the heaters MH1, MH2 and the thermistor resistors 253, 263 are held by the insulating film 22; however, the portion of the insulating film 22 that does not overlap any of the heaters MH1, MH2 and the thermistor resistors 253, 263 in plan view may be removed.

[0016] The insulating films 22 to 24 may be made of an inorganic insulating material such as silicon oxide or silicon nitride. The heaters MH1 and MH2 have a configuration in which a wiring made of a metal material having a relatively high melting point, for example, molybdenum (Mo), platinum (Pt), gold (Au), tungsten (W), tantalum (Ta), palladium (Pd), iridium (Ir), or an alloy containing any two or more of these, is meandered in a meander shape. One end of the heater MH1 is connected to the pad electrode 271, and the other end of the heater MH1 is connected to the pad electrode 272. One end of the heater MH2 is connected to the pad electrode 281, and the other end of the heater MH2 is connected to the pad electrode 282.

[0017] The thermistor resistors 253 and 263 are made of materials whose resistance changes with temperature, such as vanadium oxide, amorphous silicon, polycrystalline silicon, spinel-type crystalline oxides containing manganese, titanium oxide, or yttrium-barium-copper oxide. For example, thermistor resistors 253 and 263 are NTC thermistors with a negative temperature coefficient of resistance. A pair of thermistor electrodes 251 and 252 are in contact with thermistor resistor 253. Thus, the resistance between the pair of thermistor electrodes 251 and 252 is determined by the resistance of thermistor resistor 253 located between these electrodes. Thermistor electrodes 251 and 252 are connected to pad electrodes 273 and 274, respectively. Similarly, a pair of thermistor electrodes 261 and 262 are in contact with thermistor resistor 263. As a result, the resistance between the pair of thermistor electrodes 261 and 262 is determined by the resistance of the thermistor resistor 263 located between these electrodes. Thermistor electrodes 261 and 262 are connected to pad electrodes 283 and 284, respectively. In other words, each of the pad electrodes 273, 274, 283, and 284 is connected to either sensing element S1 or sensing element S2.

[0018] As shown in Figure 2, the sensor chip 20 is fixed to the sensor substrate 10 by adhesive members 41-43. The adhesive members 41-43 are located between the back surface 215 on the -Z direction side of the base material 21 constituting the sensor chip 20 and the main surface 11 of the sensor substrate 10.

[0019] The sensor chip 20 has a region A1 located on the -X side, a region A2 located on the +X side, and a region A3 sandwiched between regions A1 and A2 from the X direction. Region A3 is a region with a constant width in the X direction. Regions A1 and A3 are in contact, and their boundary line extends in the Y direction (second direction) which is perpendicular to the X direction in a plan view from the Z direction. Regions A2 and A3 are in contact, and their boundary line extends in the Y direction which is perpendicular to the X direction in a plan view from the Z direction. Sensing element S1 is located in region A1, sensing element S2 is located in region A2, and pad electrodes 271~274, 281~284 are located in region A3. In this embodiment, pad electrodes are not provided in regions A1 and A2.

[0020] Bonding wires W are connected to each of the pad electrodes 271-274 and 281-284 provided on the sensor chip 20, and the pad electrodes 271-274 and 281-284 are connected via the bonding wires W to pad electrodes 371-374 and 381-384 provided on the main surface 11 of the sensor substrate 10. In the example shown in Figure 1, pad electrodes 371, 373, 381, and 383 are located on the +Y direction side as viewed from the sensor chip 20, and pad electrodes 372, 374, 382, ​​and 384 are located on the -Y direction side as viewed from the sensor chip 20.

[0021] Figure 3 is a circuit diagram of the gas sensor 50 using the sensor device 100.

[0022] The gas sensor 50 shown in Figure 3 consists of a sensor chip 20 included in the sensor device 100 and a signal processing circuit 60 connected thereto. The sensor chip 20 includes thermistors Rd1 and Rd2 connected in series in that order between the power supply Vcc and ground GND, and heaters MH1 and MH2. Thermistor Rd1 consists of a thermistor resistor 253 and a pair of thermistor electrodes 251 and 252 as shown in Figure 1. Thermistor Rd2 consists of a thermistor resistor 263 and a pair of thermistor electrodes 261 and 262 as shown in Figure 1.

[0023] Thermistor Rd1 changes temperature in response to changes in the temperature of heater MH1. Thermistor Rd2 changes temperature in response to changes in the temperature of heater MH2. A gas detection signal Vgas appears at the connection point of thermistors Rd1 and Rd2. Thermistor Rd1 is a temperature sensing element for detection, and thermistor Rd2 is a temperature sensing element for reference.

[0024] When measuring gas concentration using the gas sensor 50, thermistor Rd1 is heated by heater MH1 to approximately 150°C (an example of a first temperature range), and thermistor Rd2 is heated by heater MH2 to approximately 300°C (an example of a second temperature range). The first temperature range is a predetermined temperature range included in the range of 100°C or more and 230°C or less, for example, a temperature range around 150°C. The second temperature range is a predetermined temperature range included in the range of 250°C or more and 450°C or less, for example, a temperature range around 300°C. In this specification, "temperature range" has a temperature range of, for example, 1°C or less. For example, the temperature range around 150°C may be the range of 149.5°C or more and 150.5°C or less. Also, for example, the temperature range around 300°C may be the range of 299.5°C or more and 300.5°C or less. Thermistor Rd1 is designed to have a predetermined resistance when heated to 150°C, while thermistor Rd2 is designed to have a predetermined resistance when heated to 300°C. The first temperature range (around 150°C in this example) and the second temperature range (around 300°C in this example) are in different temperature ranges, with the first temperature range being lower than the second temperature range in this example.

[0025] When a thermistor Rd1, a temperature-sensing element used for detection, is heated to around 150°C, and CO2 gas is present in the measurement atmosphere, the heat dissipation characteristics of thermistor Rd1 change according to its concentration. This change manifests as a change in the temperature of thermistor Rd1, that is, a change in its resistance. Specifically, in the temperature range around 150°C, CO2 gas has lower heat dissipation properties than air, so the higher the concentration of CO2 gas, the higher the temperature of thermistor Rd1 rises. Therefore, if thermistor Rd1 is heated to 150°C when the CO2 gas concentration in the measurement atmosphere is, for example, zero, then when CO2 gas is present in the measurement atmosphere, the temperature of thermistor Rd1 will rise above 150°C according to its concentration. As a result, the higher the CO2 gas concentration in the measurement atmosphere, the lower the resistance of thermistor Rd1 becomes.

[0026] On the other hand, even when the thermistor Rd2, which is the reference temperature-sensing element, is heated to around 300°C and CO2 gas is present in the measurement atmosphere, the heat dissipation characteristics of thermistor Rd2 hardly change with respect to its concentration, and the temperature of thermistor Rd2 also hardly changes. Therefore, the change in resistance value of thermistor Rd2 heated to around 300°C due to the CO2 gas concentration is sufficiently smaller than the change in resistance value of thermistor Rd1 heated to around 150°C due to the CO2 gas concentration. The change in resistance value of thermistor Rd2 heated to around 300°C due to the CO2 gas concentration can be negligible. As a result, when thermistor Rd1 is heated to around 150°C and thermistor Rd2 is heated to around 300°C (for example, when the CO2 gas concentration in the measurement atmosphere is zero, thermistor Rd1 is heated to 150°C and thermistor Rd2 is heated to 300°C), a gas detection signal Vgas corresponding to the CO2 gas concentration in the measurement atmosphere appears at the connection point of thermistor Rd1 and thermistor Rd2. On the other hand, even if other gases are present in the measurement atmosphere that do not have a significant difference in heat dissipation characteristics when thermistor Rd1 is heated to around 150°C and when thermistor Rd2 is heated to around 300°C, the concentration of those gases has almost no effect on the gas detection signal Vgas. This makes it possible for the sensor chip 20 to selectively detect the CO2 gas concentration.

[0027] The signal processing circuit 60 includes differential amplifiers 61-63, an AD converter (ADC) 64, a DA converter (DAC) 65, and a control circuit 66. Part or all of the signal processing circuit 60 may be provided on the sensor board 10. Alternatively, part or all of the signal processing circuit 60 may be provided on a different board from the sensor board 10 (for example, a product board 70).

[0028] The differential amplifier 63 compares the gas detection signal Vgas with the reference potential Vref output from the DA converter 65 to generate an amplified signal Vamp, which is the level difference (=Vgas-Vref) between the gas detection signal Vgas and the reference potential Vref. The amplified signal Vamp is input to the AD converter 64. The AD converter 64 generates a digital value by performing an AD conversion on the amplified signal Vamp and supplies this to the control circuit 66.

[0029] The control circuit 66 calculates the concentration of the CO2 gas to be measured based on the AD-converted amplified signal Vamp and generates an output signal Vout indicating the CO2 gas concentration. The output signal Vout is output to the outside of the gas sensor 50. The CO2 gas concentration can also be calculated using a calculation formula set in the control circuit 66. Furthermore, the control circuit 66 supplies the digital values ​​of various control parameters to the DA converter 65. The DA converter 65 generates heater voltages Vmh1, Vmh2 and reference potential Vref by converting the digital values ​​of the various control parameters into analog. Heater voltage Vmh1 is applied to heater MH1 via differential amplifier 61 which constitutes a voltage follower, thereby heating heater MH1. Heater voltage Vmh2 is applied to heater MH2 via differential amplifier 62 which constitutes a voltage follower, thereby heating heater MH2.

[0030] As shown in Figure 1, the pad electrodes 271-274 and 281-284 on the sensor chip 20 are all located in region A3. In contrast, if, for example, the pad electrodes 271-274 and 281-284 were placed in regions A1 and A2 of the sensor chip 20, the heat transferred from the electronic component 30 to the sensor chip 20 via the product substrate 70, sensor substrate 10, and bonding wire W would be predominantly transferred via the bonding wire W connected to the pad electrodes located in region A1. As a result, the heat transferred to sensing element S1 would be greater than the heat transferred to sensing element S2, creating a large difference between the amount of heat conducted to sensing element S1 via the product substrate 70, sensor substrate 10, and bonding wire W, and the amount of heat conducted to sensing element S2 via the product substrate 70, sensor substrate 10, and bonding wire W. In other words, the thermistor Rd1, which is the temperature sensing element for detection, receives more heat from the electronic component 30 than the thermistor Rd2, which is the temperature sensing element for reference. As explained using Figure 3, since thermistors Rd1 and Rd2 constitute a half-bridge circuit, if there is a large difference between the amount of heat conducted to the sensing element S1 via the product substrate 70, sensor substrate 10 and bonding wire W, and the amount of heat conducted to the sensing element S2 via the product substrate 70, sensor substrate 10 and bonding wire W, this will result in a large measurement error.

[0031] In contrast, in this embodiment, pad electrodes 271-274 and 281-284 are arranged together in region A3, which is located between region A1 where sensing element S1 is located and region A2 where sensing element S2 is located. In other words, sensing elements S1 and S2 are aligned in the X direction, and in a plan view from the Z direction, the positions of the pad electrodes 271-274 and 281-284 arranged in region A3 in the X direction are between the position of sensing element S1 in the X direction and the position of sensing element S2 in the X direction. As a result, even when the electronic component 30 generates heat due to its operation, it is possible to suppress the difference between the amount of heat conducted from the electronic component 30 to the sensing element S1 via the product substrate 70, sensor substrate 10 and bonding wire W, and the amount of heat conducted from the electronic component 30 to the sensing element S2 via the product substrate 70, sensor substrate 10 and bonding wire W. In other words, the difference in the effect of heat conduction from the electronic component 30 via the bonding wire W between sensing element S1 and sensing element S2 is suppressed to a small extent, making it possible to suppress measurement errors caused by heat generation from the electronic component 30 to a small extent.

[0032] Furthermore, in this embodiment, in a plan view from the Z direction, which is the thickness direction of the sensor substrate 10, the pad electrodes 271-274 and 281-284 are located in the portion sandwiched between sensing elements S1 and S2 from the X direction, thus making it possible to reduce the size of the sensor chip in the Y direction intersecting the X direction.

[0033] In the example shown in Figure 1, pad electrodes 271-274 and 281-284 are all located in region A3, but some pad electrodes may be located in region A1 or A2. Even in this case, if the most pad electrodes are placed in region A3 of the sensor chip 20 so that heat conduction via the pad electrodes located in region A3 of the sensor chip 20 becomes dominant, it is possible to control the measurement error caused by heat generation from the electronic component 30 to a small extent. In other words, if the most pad electrodes are placed in the X-direction position between the position of sensing element S1 in the X-direction and the position of sensing element S2 in the X-direction in a plan view from the Z-direction, it is possible to suppress the measurement error caused by heat generation from the electronic component 30 to a small extent.

[0034] Furthermore, in this embodiment, as shown in Figure 2, adhesive member 41 is placed in region A1 of the sensor chip 20, adhesive member 42 is placed in region A2 of the sensor chip 20, and adhesive member 43 is placed in region A2 of the sensor chip 20. The volume of adhesive member 43 provided in region A3 is larger than the volumes of adhesive members 41 and 42. As a result, the heat conduction from the sensor substrate 10 to the sensor chip 20 via adhesive members 41-43 is greater through adhesive member 43 than through adhesive members 41 and 42. In other words, the heat conduction from the sensor substrate 10 to the sensor chip 20 via adhesive members 41-43 is greatest through adhesive member 43. As a result, it is possible to suppress the difference between the amount of heat conducted from the electronic component 30 to the sensing element S1 via the product substrate 70, sensor substrate 10, and adhesive members 41-43, and the amount of heat conducted from the electronic component 30 to the sensing element S2 via the product substrate 70, sensor substrate 10, and adhesive members 41-43. Alternatively, the adhesive members 41 and 42 may be omitted, and the sensor chip 20 may be fixed to the sensor substrate 10 using only the adhesive member 43.

[0035] In the example shown in Figure 1, one bonding wire W is assigned to each of the pad electrodes 271-274 and 281-284. However, as shown in the first modified sensor device 100A in Figure 4, multiple bonding wires W may be assigned to some of the pad electrodes 271-274 and 281-284. In the first modified sensor device shown in Figure 4, two bonding wires W are assigned to each of the pad electrodes 271, 272, 281, and 282 connected to the heaters MH1 and MH2, thereby reducing the wiring resistance of the wiring that supplies voltage to the heaters MH1 and MH2. Alternatively, as shown in the second modified sensor device 100B in Figure 5, multiple pad electrodes provided on the sensor substrate 10 may be assigned to some of the pad electrodes provided on the sensor chip 20. In the second modified example shown in Figure 5, two pad electrodes 371A and 371B are assigned to pad electrode 271, two pad electrodes 372A and 372B are assigned to pad electrode 272, two pad electrodes 381A and 381B are assigned to pad electrode 281, and two pad electrodes 382A and 382B are assigned to pad electrode 282, with each corresponding pad electrode connected by a single bonding wire W. Even in this case, it is possible to reduce the wiring resistance of the wiring that supplies voltage to heaters MH1 and MH2.

[0036] Figure 6 is a schematic plan view showing the configuration of the sensor device 100C according to the third modified example.

[0037] The sensor device 100C, a third modified example shown in Figure 6, differs from the sensor device 100 shown in Figure 1 in that the pad electrodes 272, 273, 281, and 284 are located in the third region A3, in the area sandwiched between sensing elements S1 and S2 from the X direction, while the pad electrodes 271, 274, 282, and 283 are located outside the area sandwiched between sensing elements S1 and S2 from the X direction in the third region A3.

[0038] As illustrated by the third modified sensor device 100C, if a portion of the pad electrodes 271-274 and 281-284 are placed outside the third region A3, which is sandwiched from the X direction by sensing elements S1 and S2, the degree of freedom in the layout of the pad electrodes on the sensor chip 20 can be increased.

[0039] Figure 7 is a schematic plan view showing the configuration of the sensor device 100D according to the fourth modified example.

[0040] The sensor device 100D according to the fourth modification shown in Figure 7 differs from the sensor device 100 shown in Figure 1 in that the pad electrodes 271-274 and 281-284 are all located in the third region A3, outside the area sandwiched between sensing elements S1 and S2 from the X direction. In the fourth modification shown in Figure 7, the pad electrodes 271, 273, 281, and 283 are located in the third region A3, on the +Y side when viewed from the area sandwiched between sensing elements S1 and S2 from the X direction, while the pad electrodes 272, 274, 282, and 284 are located in the third region A3, on the -Y side when viewed from the area sandwiched between sensing elements S1 and S2 from the X direction.

[0041] As illustrated by the fourth modified sensor device 100D, if all of the pad electrodes 271-274 and 281-284 are placed outside the third region A3, which is sandwiched between sensing elements S1 and S2 from the X direction, the distance between the pad electrodes 271-274 and 281-284 and the sensing elements S1 and S2 increases. This reduces the amount of heat conducted from the electronic component 30 to the sensing elements S1 and S2 via the product substrate 70, sensor substrate 10, and bonding wire W.

[0042] Figure 8 is a schematic plan view showing the configuration of a sensor device 200 according to a second embodiment of the technology described herein.

[0043] As shown in Figure 8, the sensor device 200 according to the second embodiment differs from the sensor device 100 according to the first embodiment in that both sensing element S1 and sensing element S2 are arranged in a single cavity 210 provided in the substrate 21 of the sensor chip 20. The other basic configurations are the same as those of the sensor device 100 according to the first embodiment, so the same reference numerals are used for the same elements, and redundant explanations are omitted.

[0044] In the sensor device 200 according to the second embodiment, the pad electrodes 271-274 and 281-284 are arranged in two separate locations within region A3 to avoid the cavity 210. Therefore, in a plan view from the Z direction, the pad electrodes 271-274 and 281-284 are located outside the third region A3, which is sandwiched between sensing elements S1 and S2 from the X direction. In the example shown in Figure 8, the pad electrodes 271, 273, 281, and 283 are located on the +Y side when viewed from the third region A3, which is sandwiched between sensing elements S1 and S2 from the X direction, while the pad electrodes 272, 274, 282, and 284 are located on the -Y side when viewed from the third region A3, which is sandwiched between sensing elements S1 and S2 from the X direction. In other words, the pad electrodes 271, 273, 281, 283 and pad electrodes 272, 274, 282, 284, which are arranged in two separate locations, are positioned to sandwich the cavity 210 from the Y direction in a plan view from the Z direction.

[0045] As illustrated by the sensor device 200 according to the second embodiment, both sensing element S1 and sensing element S2 may be placed in a single cavity 210. Even in this case, by arranging the pad electrodes 271-274 and 281-284 in region A3, it is possible to suppress the difference between the amount of heat conducted from the electronic component 30 to the sensing element S1 via the product substrate 70, sensor substrate 10, and bonding wire W, and the amount of heat conducted from the electronic component 30 to the sensing element S2 via the product substrate 70, sensor substrate 10, and bonding wire W. In other words, the difference between sensing element S1 and sensing element S2 in the effect of heat conduction from the electronic component 30 via the bonding wire W is suppressed to a small extent.

[0046] Figure 9 is a schematic plan view showing the configuration of the sensor device 200A according to the fifth modified example.

[0047] The sensor device 200A according to the fifth modification shown in Figure 9 differs from the sensor device 200 according to the second embodiment in that the pad electrodes 271-274 and 281-284 are all located in the third region A3, on the +Y side when viewed from the portion sandwiched between sensing elements S1 and S2 from the X direction. The other basic configurations are the same as those of the sensor device 200 according to the second embodiment, so the same reference numerals are used for the same elements, and redundant explanations are omitted. As illustrated by the sensor device 200A according to the fifth modification, even when both sensing elements S1 and S2 are arranged in a single cavity 210, the pad electrodes 271-274 and 281-284 may be arranged together in one place.

[0048] Figure 10 is a schematic plan view showing the configuration of the sensor device 200B according to the sixth modified example.

[0049] The sixth modified sensor device 200B shown in Figure 10 differs from the sensor device 200 shown in Figure 8 in that heaters MH1 and MH2 are omitted, and instead heater MH3 is placed between sensing elements S1 and S2. Furthermore, sensing element S1 is composed of a thermocouple made of metal conductors 231 and 232, and sensing element S2 is composed of a thermocouple made of metal conductors 233 and 234. The metal conductors 231-234 and heater MH3 may be supported by an insulating film 22. The insulating film 22 between sensing element S1 and heater MH3 is removed, and the insulating film 22 between sensing element S2 and heater MH3 is removed, and a space exists between heater MH3 and each sensing element S1 and S2. One end of heater MH3 is connected to pad electrode 241, and the other end of heater MH3 is connected to pad electrode 242. The pad electrodes 241 and 242 are connected to pad electrodes 341 and 342 provided on the main surface 11 of the sensor substrate 10 via bonding wires W, respectively.

[0050] In the example shown in Figure 10, pad electrodes 241, 273, and 283 are positioned on the +Y side when viewed from the third region A3, which is the area sandwiched between sensing elements S1 and S2 from the X direction, and pad electrodes 242, 274, and 284 are positioned on the -Y side when viewed from the third region A3, which is the area sandwiched between sensing elements S1 and S2 from the X direction. In other words, the pad electrodes 241, 273, and 283 and pad electrodes 242, 274, and 284, which are positioned in two separate locations, are arranged to sandwich the cavity 210 from the Y direction in a plan view from the Z direction.

[0051] Heater MH3 is a common heater for sensing elements S1 and S2. When heater MH3 is heated, heat from heater MH3 is conducted to sensing elements S1 and S2 through the space between heater MH3 and each sensing element S1 and S2. Here, the distance in the X direction between heater MH3 and sensing element S1 is different from the distance in the X direction between heater MH3 and sensing element S2. Therefore, when heater MH3 is heated, a temperature difference is created between sensing elements S1 and S2.

[0052] Furthermore, when the concentration of CO2 gas in the measurement atmosphere fluctuates, the thermal conductivity of the space between the heater MH3 and each sensing element S1, S2 changes, and therefore the temperature difference between sensing element S1 and sensing element S2 changes. For example, when the CO2 gas concentration increases, the thermal conductivity of the space between the heater MH3 and each sensing element S1, S2 decreases, and the temperature difference between sensing element S1 and sensing element S2 decreases. Figure 10 shows an example where each sensing element S1 and S2 is composed of one thermocouple, but each sensing element S1 and S2 may be composed of multiple thermocouples. In other words, sensing elements S1 and S2 may be thermopile elements.

[0053] Figure 11 is a circuit diagram of the sensor device 200B.

[0054] As shown in Figure 11, the sensor device 200B consists of the sensor chip 20 shown in Figure 10 and the signal processing circuit 60A connected thereto. The sensor chip 20 includes sensing elements S1 and S2, which are thermocouples or thermopile elements, and a heater MH3 that heats the sensing elements S1 and S2. When heating the heater MH3, a heater voltage Vmh3 supplied from the DA converter 65 is applied to the heater MH3.

[0055] The temperature of the hot junctions of sensing elements S1 and S2 changes in accordance with the temperature change of the heater MH3. Sensing elements S1 and S2 are temperature-sensitive elements whose potential difference across their ends changes with temperature. The potential difference across the ends of sensing element S1 is used as the output signal Vtp1, and the potential difference across the ends of sensing element S2 is used as the output signal Vtp2. The reference potential Vref2 is generated by fixed resistors R1 and R2. Fixed resistors R1 and R2 are connected in series between the power supply Vcc and ground GND, and the reference potential Vref2 appears at the connection point N0. The reference potential Vref2 is supplied in common to the inverting input terminal (-) of the differential amplifiers 67 and 68 included in the signal processing circuit 60A. The output signal Vtp1 is supplied to the non-inverting input terminal (+) of the differential amplifier 67 included in the signal processing circuit 60A, and the output signal Vtp2 is supplied to the non-inverting input terminal (+) of the differential amplifier 68 included in the signal processing circuit 60A.

[0056] The potential supplied to the non-inverting input terminal (+) of differential amplifier 67 is the level obtained by superimposing the output signal Vtp1, which corresponds to the electromotive force of the temperature-dependent sensing element S1, onto the reference potential Vref2. The potential supplied to the non-inverting input terminal (+) of differential amplifier 68 is the level obtained by superimposing the output signal Vtp2, which corresponds to the electromotive force of the temperature-dependent sensing element S2, onto the reference potential Vref2.

[0057] The output signal Vtp1 is amplified by the differential amplifier 67 included in the signal processing circuit 60A to generate the gas detection signal Vgas1. The differential amplifier 67 compares the levels of the reference potential Vref2 supplied to the inverting input terminal (-) and Vref2 + Vtp1 supplied to the non-inverting input terminal (+), and generates the gas detection signal Vgas1 by amplifying the difference (=Vtp1).

[0058] The output signal Vtp2 is amplified by the differential amplifier 68 included in the signal processing circuit 60A to generate the gas detection signal Vgas2. The differential amplifier 68 compares the levels of the reference potential Vref2 supplied to the inverting input terminal (-) and Vref2 + Vtp2 supplied to the non-inverting input terminal (+), and generates the gas detection signal Vgas2 by amplifying the difference (=Vtp2).

[0059] The differential amplifier 69 generates an amplified signal Vamp0 by comparing the gas detection signal Vgas1 and the gas detection signal Vgas2, thereby amplifying the level difference between Vgas1 and Vgas2 (=Vgas1-Vgas2). The amplified signal Vamp0 is supplied to the differential amplifier 63. The differential amplifier 63 generates an amplified signal Vamp1 by comparing the amplified signal Vamp0 with the reference potential Vref1, thereby amplifying the level difference between the amplified signal Vamp0 and the reference potential Vref1 (=Vamp0-Vref1).

[0060] Even with this circuit configuration, when the heater MH3 is heated during gas concentration measurement, as the CO2 gas concentration in the measurement atmosphere increases, the thermal conductivity of the space between the heater MH3 and each sensing element S1, S2 decreases, and the temperature difference between sensing element S1 and sensing element S2 decreases. As a result, the amplified signal Vamp0 changes (decreases). The amplified signal Vamp0 is compared with the reference potential Vref1 by the differential amplifier 63, and the amplified signal Vamp1 is generated by amplifying the level difference (=Vamp0-Vref1). The amplified signal Vamp1 is supplied to the control circuit 66 via the AD converter 64. This generates an output signal Vout indicating the CO2 gas concentration in the measurement atmosphere.

[0061] As illustrated by the sixth modified sensor device 200B, the sensor device may also output a signal (output signal Vout) based on the difference between the output of sensing element S1 (=Vtp1) and the output of sensing element S2 (=Vtp2).

[0062] Figure 12 is a schematic plan view showing the configuration of a sensor device 300 according to a third embodiment of the technology described herein.

[0063] As shown in Figure 12, the sensor device 300 according to the third embodiment differs from the sensor device 100 according to the first embodiment in that a cavity 213 is provided in the sensor chip 20, and a sensing element S3 is arranged in the cavity 213. The sensing element S3 is a temperature sensor, for example, a temperature sensor for measuring ambient temperature. The output signal of the sensing element S3, which is a temperature sensor, is supplied to a signal processing circuit 60 shown in Figure 3, for example, and is used for adjusting the heater voltages Vmh1 and Vmh2 according to the ambient temperature.

[0064] Sensing element S3 is composed of a pair of thermistor electrodes 291 and 292 and a thermistor resistor 293 that is in contact with the thermistor electrodes 291 and 292. Thermistor electrode 291 is connected to pad electrode 294, and thermistor electrode 292 is connected to pad electrode 295. In other words, each of the pad electrodes 273, 274, 283, 284, 294, and 295 is connected to either sensing element S1, sensing element S2, or sensing element S3. Pad electrode 294 is connected via bonding wire W to pad electrode 394 provided on the main surface 11 of the sensor substrate 10. Pad electrode 295 is connected via bonding wire W to pad electrode 395 provided on the main surface 11 of the sensor substrate 10.

[0065] Sensing element S3 is located in the area sandwiched between sensing elements S1 and S2 from the X direction. In this embodiment as well, pad electrodes 271-274, 281-284, 294, and 295 are arranged in the third region A3. In the example shown in Figure 12, pad electrodes 272, 273, 282, 283, and 295 are located in the third region A3, on the +Y side when viewed from the area sandwiched between sensing elements S1 and S2 from the X direction, and pad electrodes 271, 274, 281, 284, and 294 are located in the third region A3, on the -Y side when viewed from the area sandwiched between sensing elements S1 and S2 from the X direction.

[0066] As illustrated by the sensor device 300 according to the third embodiment, the sensor chip 20 may include another sensing element S3. Also, the sensing elements S1 to S3 may be arranged in a line in the X direction. Furthermore, if the sensing element S3 is placed in the third region A3, some of the pad electrodes 272, 273, 282, 283, 295 and some of the pad electrodes 271, 274, 281, 284, 294, which are arranged in two separate locations in region A3, may be arranged so as to sandwich the third sensing element S3 from the Y direction in a plan view from the Z direction. Alternatively, all of the pad electrodes 272, 273, 282, 283, 295 and all of the pad electrodes 271, 274, 281, 284, 294, which are arranged in two separate locations in region A3, may be arranged so as to sandwich the third sensing element S3 from the Y direction in a plan view from the Z direction.

[0067] In the sensor device 300 according to the third embodiment, the influence of heat conduction from the electronic component 30 is greater in sensing element S3 than in sensing elements S1 and S2. However, as explained with reference to Figure 3, since sensing elements S1 and S2 constitute a half-bridge circuit, if there is a large difference between the amount of heat conducted to sensing element S1 via the product substrate 70, sensor substrate 10 and bonding wire W and the amount of heat conducted to sensing element S2 via the product substrate 70, sensor substrate 10 and bonding wire W, this will result in a large measurement error. On the other hand, since sensing element S3, which is a temperature sensor, does not constitute a bridge circuit with the other sensing elements, the measurement error due to heat conducted to sensing element S3 via the product substrate 70, sensor substrate 10 and bonding wire W is smaller than that of sensing elements S1 and S2.

[0068] Figure 13 is a schematic plan view showing the configuration of a sensor device 400 according to a fourth embodiment of the technology described herein.

[0069] As shown in Figure 13, the sensor device 400 according to the fourth embodiment differs from the sensor device 300 according to the third embodiment in the position of the sensing element S3.

[0070] In this embodiment, sensing elements S1 and S2 are arranged in the X direction, while the position of sensing element S3 in the Y direction is different from the position of sensing elements S1 and S2 in the Y direction. This forms a triangular region with sensing elements S1 to S3 as its vertices. In the example shown in Figure 13, pad electrodes 271 to 274, 281 to 284, 294, and 295 are arranged in region A3 so as to overlap with this triangular region. In the example shown in Figure 13, sensing element S3 is located in region A3 of the sensor chip 20, but part or all of sensing element S3 may be located in region A1 or A2 of the sensor chip 20.

[0071] Although some elements, such as the shape of the sensor substrate 10 and the sensor chip 20, and the position of the pad electrodes provided on the main surface 11 of the sensor substrate 10, differ from the sensor device 300 according to the third embodiment, the basic configuration is the same as that of the sensor device 300 according to the third embodiment. Therefore, the same reference numerals are used for the same elements, and redundant explanations are omitted.

[0072] Figure 14 is a schematic diagram illustrating the positional relationship between the sensing elements S1-S3 and the pad electrodes 271-274, 281-284, 294, and 295.

[0073] As shown in Figure 14, when the alignment direction of sensing elements S1 and S3 is defined as direction B, and the alignment direction of sensing elements S2 and S3 is defined as direction C, in a plan view from the Z direction, the region between the position of sensing element S1 in direction B and the position of sensing element S3 in direction B is defined as region B1, and in a plan view from the Z direction, the region between the position of sensing element S2 in direction C and the position of sensing element S3 in direction C is defined as region C1. The X direction, B direction, and C direction are different directions from each other. Pad electrodes 271~274, 281~284, 294, and 295 are arranged within region A4, which is within the range of region A3 and overlaps with regions B1 and C1. In other words, the positions of the pad electrodes 271-274, 281-284, 294, and 295 located in region A3 in direction B are between the position of sensing element S1 and the position of sensing element S3 in direction B, and the positions of the pad electrodes 271-274, 281-284, 294, and 295 located in region A3 in direction C are between the position of sensing element S2 and the position of sensing element S3 in direction C. As a result, the difference in the amount of heat transferred from the sensor substrate 10 to the sensing elements S1-S3 via the bonding wire W is suppressed to a small extent. That is, the difference in the effect of heat conduction from the electronic component 30 via the bonding wire W between the sensing elements S1-S3 is suppressed to a small extent.

[0074] In particular, if the pad electrodes 271-274, 281-284, 294, and 295 are arranged so as to overlap with the triangular region with sensing elements S1-S3 as its vertices, the difference in the amount of heat transferred from the sensor substrate 10 to the sensing elements S1-S3 via the bonding wire W will be further reduced. Some of the pad electrodes may be placed outside the triangular region with sensing elements S1-S3 as its vertices. Even in this case, if the largest number of pad electrodes are placed in the triangular region with sensing elements S1-S3 as its vertices so that heat conduction via the pad electrodes in that region becomes dominant, the difference in the amount of heat transferred from the sensor substrate 10 to the sensing elements S1-S3 via the bonding wire W will be further reduced. In other words, the difference in the effect of heat conduction from the electronic component 30 via the bonding wire W between the sensing elements S1-S3 will be further reduced.

[0075] Figure 15 is a schematic plan view showing the configuration of a sensor device 500 according to a fifth embodiment of the technology described herein.

[0076] As shown in Figure 15, the sensor device 500 according to the fifth embodiment differs from the sensor device 100 according to the first embodiment in that another electronic component 31 is mounted on the mounting surface 71 of the product substrate 70, and in a plan view from the Z direction, the pad electrodes 371-374 and 381-384 are arranged on the same side relative to the sensor chip 20 and are arranged in a line in the X direction. The electronic component 31 is a heat-generating element that generates heat through its operation. In this embodiment, in a plan view from the Z direction, the electronic component 31 is arranged on the +Y direction side of the sensor device 500, and the pad electrodes 371-374 and 381-384 are arranged on the -Y direction side of the sensor chip 20.

[0077] Although some elements, such as the shape of the sensor substrate 10, differ from the sensor device 100 according to the first embodiment, the basic configuration is the same as that of the sensor device 100 according to the first embodiment. Therefore, the same reference numerals are used for the same elements, and redundant explanations are omitted.

[0078] As illustrated by the sensor device 500 according to the fifth embodiment, if the pad electrodes 371-374 and 381-384 are arranged on one side relative to the sensor chip 20 in a plan view from the Z direction, heat transferred from the electronic component 31 located on the opposite side of the sensor chip 20 to the sensor substrate 10 will be less likely to be transferred to the sensor chip 20 via the bonding wire W. In the example shown in Figure 15, the pad electrodes 371-374 and 381-384 are arranged in a single row, but the pad electrodes 371-374 and 381-384 may also be arranged in multiple rows on the same side relative to the sensor chip 20 in a plan view from the Z direction.

[0079] While embodiments of the technology described herein have been explained above, it goes without saying that the technology described herein is not limited to the embodiments described above, and various modifications are possible without departing from its spirit, and these modifications are also included within the scope of the technology described herein.

[0080] For example, in the embodiments described above, the cases in which the sensing elements S1 and S2 are elements using thermistor resistors or thermocouples were explained as examples, but the sensing elements are not limited to these, and other types of elements whose characteristics change with temperature may be used instead of thermistor resistors or thermocouples. Also, in the embodiments described above, the cases in which the sensing elements S1 and S2 are elements used in a heat conduction type gas sensor were explained as examples, but the type of sensing elements S1 and S2 is not limited as long as they are used in a sensor in which heat from an external heat-generating element affects the measurement error.

[0081] Furthermore, the sensor device according to this disclosure does not need to be a sensor device used for gas sensors, as long as it measures some physical quantity based on the state of sensing element S1 and sensing element S2; it may be a sensor device that measures other physical quantities. Also, it is not necessary for one of the sensing elements S1 and S2 to be a detection element and the other to be a reference element; both sensing elements S1 and S2 may be detection elements.

[0082] The technology relating to this disclosure includes, but is not limited to, the following configuration examples.

[0083] A sensor chip according to one aspect of this disclosure comprises a first sensing element, a second sensing element, and a plurality of first pad electrodes, wherein the first sensing element is located in a first region of the sensor chip, the second sensing element is located in a second region of the sensor chip, and the plurality of first pad electrodes are most frequently located in a third region sandwiched between the first and second regions from a first direction. According to this, when the sensor chip is mounted on a sensor substrate and the sensor chip and the sensor substrate are connected by bonding wires connected to each of the plurality of first pad electrodes, the difference between the amount of heat transmitted from the sensor substrate to the first sensing element via the bonding wires and the amount of heat transmitted from the sensor substrate to the second sensing element via the bonding wires is suppressed to a small extent. In other words, the difference in the effect of heat conduction from the heat-generating material between the first sensing element and the second sensing element is suppressed to a small extent.

[0084] In the sensor chip described above, the multiple first pad electrodes may be arranged in a third region instead of the first and second regions of the sensor chip. According to this, when the sensor chip is mounted on a sensor substrate and the sensor chip and the sensor substrate are connected by bonding wires connected to each of the multiple first pad electrodes, the difference between the amount of heat transferred from the sensor substrate to the first sensing element via the bonding wires and the amount of heat transferred from the sensor substrate to the second sensing element via the bonding wires is suppressed to a smaller extent.

[0085] In the sensor chip described above, in a plan view taken from the thickness direction of the sensor chip, at least a portion of the multiple first pad electrodes may be located in a third region, which is sandwiched between the first sensing element and the second sensing element from the first direction. According to this, when the sensor chip is mounted on a sensor substrate and the sensor chip and the sensor substrate are connected by bonding wires connected to each of the multiple first pad electrodes, the difference between the amount of heat transmitted from the sensor substrate to the first sensing element via the bonding wires and the amount of heat transmitted from the sensor substrate to the second sensing element via the bonding wires is suppressed to a smaller extent.

[0086] In the sensor chip described above, in a plan view taken from the thickness direction of the sensor chip, at least a portion of the multiple first pad electrodes may be located outside the third region, which is sandwiched between the first sensing element and the second sensing element from the first direction. This makes it possible to increase the distance between the multiple first pad electrodes and the first and second sensing elements.

[0087] In the sensor chip described above, the first sensing element and the second sensing element may be arranged within a single cavity in a plan view taken from the thickness direction of the sensor chip. This makes it possible to miniaturize the sensor chip.

[0088] In the sensor chip described above, in a plan view taken from the thickness direction of the sensor chip, at least some of the multiple first pad electrodes may be arranged in a third region so as to sandwich the cavity from a second direction intersecting the first direction. This makes it possible to increase the distance between the multiple first pad electrodes and the first and second sensing elements.

[0089] The sensor chip described above may further include a third sensing element, which may be positioned in the area sandwiched between the first and second sensing elements from the first direction. This ensures sufficient distance between the first and second sensing elements, thus reducing the likelihood of thermal interference between them.

[0090] In the sensor chip described above, in a plan view taken from the thickness direction of the sensor chip, at least some of the multiple first pad electrodes may be arranged in a third region so as to sandwich the third sensing element from a second direction intersecting the first direction. This makes it possible to increase the distance between the multiple first pad electrodes and the first and second sensing elements.

[0091] The above sensor chip further comprises a third sensing element, wherein the first and third sensing elements are aligned in a second direction, and the second and third sensing elements are aligned in a third direction. In a plan view from the thickness direction of the sensor chip, the positions of the multiple first pad electrodes arranged in the third region in the second direction are between the position of the first sensing element in the second direction and the position of the third sensing element in the second direction, and the positions of the multiple first pad electrodes arranged in the third region in the third direction may be between the position of the second sensing element in the third direction and the position of the third sensing element in the third direction. According to this, when the sensor chip is mounted on a sensor substrate and the sensor chip and the sensor substrate are connected by bonding wires connected to each of the multiple first pad electrodes, the difference in the amount of heat transmitted from the sensor substrate to the first to third sensing elements via the bonding wires is reduced.

[0092] In the sensor chip described above, the third sensing element may be located in the third region.

[0093] In the sensor chip described above, in a plan view from the thickness direction of the sensor chip, at least a portion of the multiple first pad electrodes are arranged in a third region such that they overlap with a triangular region with the first sensing element, the second sensing element, and the third sensing element as its vertices, and the multiple first pad electrodes may be most numerous in the triangular region. According to this, when the sensor chip is mounted on a sensor substrate and the sensor chip and the sensor substrate are connected by bonding wires connected to each of the multiple first pad electrodes, the difference in the amount of heat transmitted from the sensor substrate to the first to third sensing elements via the bonding wires is further reduced.

[0094] A sensor device according to one aspect of this disclosure comprises a sensor substrate having a plurality of second pad electrodes, the sensor chip mounted on the sensor substrate, and a plurality of bonding wires, each of which electrically connects a corresponding one of the plurality of first pad electrodes to a corresponding one of the plurality of second pad electrodes. As a result, when the sensor substrate is mounted on another product substrate on which a heat-generating element is mounted, the difference in the amount of heat transmitted from the heat-generating element to the first and second sensing elements via the sensor substrate and bonding wires is suppressed to a small extent.

[0095] In the sensor device described above, in a plan view from the thickness direction of the sensor substrate, the multiple second pad electrodes may be arranged on the same side relative to the sensor chip. This makes it possible to minimize the impact of heat generation from a heat-generating component mounted on the opposite side of the sensor chip from the multiple second pad electrodes. [Explanation of symbols]

[0096] 10 Sensor board 11 Main surface 20 sensor chips 21 Base material 22-24 Insulating film 30,31 Electronic components 41-43 Adhesive material 50 Gas Sensors 60,60A signal processing circuit 61-63, 67-69 Differential amplifier 64 AD converters 65 DA converter 66 Control circuits 70 Product Circuit Boards 71 Implementation aspects 100, 100A, 100B, 100C, 100D, 200, 200A, 200B, 300, 400, 500 Sensor Device 210-213 Cavity 214 Surface 215 Back side 231-234 Metal conductors 241, 242, 271~274, 281~284, 294, 295, 341, 342, 371~374, 371A, 371B, 372A, 372B, 381~384, 381A, 381B, 382A, 382B, 394, 395 Pad electrodes 251, 252, 261, 262, 291, 292 Thermistor electrodes 253,263,293 Thermistor Resistors A1~A4,B1,C1 area MH1~MH3 Heater N0 Connection point R1,R2 Fixed resistance Rd1, Rd2 Thermistor S1~S3 Sensing elements W bonding wire

Claims

1. The first sensing element and The second sensing element, Multiple first pad electrodes, Equipped with, The first sensing element is located in a first region of the sensor chip. The second sensing element is located in the second region of the sensor chip. The plurality of first pad electrodes are most frequently arranged in a third region sandwiched from the first direction by the first region and the second region. Sensor chip.

2. The plurality of first pad electrodes are not arranged in the first and second regions of the sensor chip, but are arranged in the third region. The sensor chip according to claim 1.

3. In a plan view of the sensor chip as seen from the thickness direction, at least a portion of the plurality of first pad electrodes is positioned in the third region, which is sandwiched from the first direction by the first sensing element and the second sensing element. The sensor chip according to claim 1.

4. In a plan view of the sensor chip as seen from the thickness direction, at least a portion of the plurality of first pad electrodes is located outside the third region, which is sandwiched from the first direction by the first sensing element and the second sensing element. The sensor chip according to claim 1.

5. In a plan view of the sensor chip as seen from the thickness direction, the first sensing element and the second sensing element are arranged within a single cavity. The sensor chip according to claim 4.

6. In a plan view of the sensor chip as seen from the thickness direction, at least a portion of the plurality of first pad electrodes are arranged in the third region such that they sandwich the cavity from a second direction intersecting the first direction. The sensor chip according to claim 5.

7. It further includes a third sensing element, The third sensing element is positioned in the portion sandwiched between the first sensing element and the second sensing element from the first direction. The sensor chip according to claim 1.

8. In a plan view of the sensor chip as seen from the thickness direction, at least a portion of the plurality of first pad electrodes are arranged in the third region such that they sandwich the third sensing element from a second direction intersecting the first direction. The sensor chip according to claim 7.

9. It further includes a third sensing element, The first sensing element and the third sensing element are aligned in the second direction. The second sensing element and the third sensing element are aligned in a third direction. In a plan view of the sensor chip from the thickness direction, the positions of the plurality of first pad electrodes arranged in the third region in the second direction are between the position of the first sensing element in the second direction and the position of the third sensing element in the second direction, and the positions of the plurality of first pad electrodes arranged in the third region in the third direction are between the position of the second sensing element in the third direction and the position of the third sensing element in the third direction. The sensor chip according to claim 1.

10. The third sensing element is located in the third region. The sensor chip according to claim 9.

11. In a plan view of the sensor chip as seen from the thickness direction, at least a portion of the plurality of first pad electrodes are arranged in the third region such that they overlap with a triangular region whose vertices are the first sensing element, the second sensing element, and the third sensing element. The plurality of first pad electrodes are arranged most frequently in the triangular region. The sensor chip according to claim 10.

12. A sensor substrate having multiple second pad electrodes, A sensor chip according to any one of claims 1 to 11 mounted on the sensor substrate, Equipped with multiple bonding wires, Each of the plurality of bonding wires electrically connects a corresponding one of the plurality of first pad electrodes to a corresponding one of the plurality of second pad electrodes. Sensor device.

13. In a plan view of the sensor substrate as seen from the thickness direction, the plurality of second pad electrodes are arranged on the same side as seen from the sensor chip. The sensor device according to claim 12.

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