Sensors and sensor systems
The sensor system with distinct regions and differential circuits enhances gas detection accuracy and miniaturization by utilizing differential temperature responses to improve sensor characteristics.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KK TOSHIBA
- Filing Date
- 2023-08-29
- Publication Date
- 2026-06-17
AI Technical Summary
Existing sensors lack the ability to improve their detection characteristics, particularly in distinguishing and accurately sensing different gases, leading to challenges in miniaturization and sensitivity.
The sensor system comprises a substrate with distinct regions, each housing elements with specific resistive members and materials, allowing for differential temperature responses to gas concentrations, and utilizing differential circuits to enhance detection accuracy.
This configuration enables precise gas detection by minimizing the effects of unintended temperature fluctuations and facilitating miniaturization, improving the sensor's ability to differentiate between gases like ammonia, methane, and hydrogen.
Smart Images
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Abstract
Description
Technical Field
[0001] Embodiments of the present invention relate to sensors and sensor systems.
Background Art
[0002] For example, there are sensors for detecting gases. In sensors, improvement of characteristics is desired.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Embodiments of the present invention provide a sensor and a sensor system capable of improving characteristics.
Means for Solving the Problems
[0005] According to embodiments of the present invention, the sensor includes an element portion. The element portion includes a substrate including a first region, a second region and a third region, a first element fixed to the first region, a second element fixed to the second region, and a third element fixed to the third region. The first element includes a first fixed portion fixed to the first region and a first film portion supported by the first fixed portion. The first film portion includes a first resistive member and a first layer including a first material. The second element includes a second fixed portion fixed to the second region and a second film portion supported by the second fixed portion. The second film portion includes a second resistive member. The third element includes a third fixed portion fixed to the third region and a third film portion supported by the third fixed portion. The third film portion includes a third resistive member. The second film portion and the third film portion satisfy at least one of the first and second conditions. In the first condition, the second and third film portions do not include the first layer. In the second condition, the second film portion includes the second layer, and the second material of the second layer is different from the first material. In the second condition, the third film portion includes the third layer, and the third material of the third layer is the same as the second material. [Brief explanation of the drawing]
[0006] [Figure 1] Figure 1 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. [Figure 2] Figure 2 is a schematic plan view illustrating a sensor according to the first embodiment. [Figure 3] Figure 3 is a schematic plan view illustrating a sensor according to the first embodiment. [Figure 4] Figure 4 is a schematic diagram illustrating the operation of the sensor according to the first embodiment. [Figure 5] Figure 5 is a schematic diagram illustrating the operation of the sensor according to the first embodiment. [Figure 6] Figure 6 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. [Figure 7] Figure 7 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. [Figure 8]Figure 8 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. [Figure 9] Figure 9 is a schematic plan view illustrating a sensor according to the first embodiment. [Figure 10] Figure 10 is a schematic plan view illustrating a sensor according to the first embodiment. [Modes for carrying out the invention]
[0007] The embodiments of the present invention will be described below with reference to the drawings. Drawings are schematic or conceptual, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of different parts, are not necessarily identical to those of reality. Even when representing the same part, the dimensions and ratios may be depicted differently in different drawings. In this specification and in each figure, elements similar to those described above are denoted by the same reference numerals with respect to previously shown figures, and detailed explanations are omitted as appropriate.
[0008] (First Embodiment) Figure 1 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. Figures 2 and 3 are schematic plan views illustrating a sensor according to the first embodiment. Figure 1 illustrates the cross-sections along lines A1-A2, A3-A4, and A5-A6 in Figures 2 and 3.
[0009] As shown in Figure 1, the sensor 110 according to this embodiment includes an element section 10E. The element section 10E includes a base 40. The base 40 includes a first region 41, a second region 42, and a third region 43. The element section 10E further includes a first element 11A, a second element 12A, and a third element 13A. The first element 11A is fixed to the first region 41. The second element 12A is fixed to the second region 42. The third element 13A is fixed to the third region 43.
[0010] At least two of the first region 41, the second region 42, and the third region 43 may be separate from each other. At least two of the first region 41, the second region 42, and the third region 43 may be continuous with each other. The boundaries between these regions may be clear or unclear. The base 40 may be, for example, a substrate. The base 40 may include, for example, a semiconductor substrate (e.g., a silicon substrate). The base 40 may include an electrical circuit. The electrical circuit may include a transistor or the like.
[0011] The first element 11A includes a first fixed portion 11F fixed to the first region 41 and a first film portion 11 supported by the first fixed portion 11F. The first film portion 11 includes a first resistive member 11r and a first layer 11L containing a first material. For example, a first gap g1 may be provided between the first region 41 and the first film portion 11.
[0012] The second element 12A includes a second fixed portion 12F fixed to the second region 42 and a second film portion 12 supported by the second fixed portion 12F. The second film portion 12 includes a second resistive member 12r. A second gap g2 may be provided between the second region 42 and the second film portion 12.
[0013] The second film portion 12 does not include the first layer 11L. Alternatively, as will be described later, the second film portion 12 may include the second layer 12L (see Figure 6). In this case, the second material of the second layer 12L is different from the first material. In the sensor 110, the second film portion 12 does not include the first layer 11L and does not include the second layer 12L.
[0014] The third element 13A includes a third fixed portion 13F fixed to the third region 43 and a third film portion 13 supported by the third fixed portion 13F. The third film portion 13 includes a third resistive member 13r. A third gap g3 may be provided between the third region 43 and the third film portion 13.
[0015] The third film portion 13 does not include the first layer 11L. Or, as will be described later, the third film portion 13 may include the third layer 13L (see FIG. 6). In this case, the third material of the third layer 13L is the same as the second material. In the sensor 110, the third film portion 13 does not include the first layer 11L and does not include the third layer 13L.
[0016] For example, the second film portion 12 and the third film portion 13 may satisfy at least one of the first condition and the second condition. In the first condition, the second film portion 12 and the third film portion 13 do not include the first layer 11L. In the second condition, the second film portion 12 includes the second layer 12L, and the second material of the second layer 12L is different from the first material. In the second condition, the third film portion 13 includes the third layer 13L, and the third material of the third layer 13L is the same as the second material.
[0017] For example, the first material of the first layer 11L includes at least one selected from the group consisting of, for example, Pt and Pd. These materials function as, for example, a catalyst. The first layer 11L is a metal film. This metal film may include other elements (metals) in addition to at least one selected from the group consisting of, for example, Pt and Pd.
[0018] In one example, the temperature of the first film portion 11 and the temperature of the second film portion 12 increase. The increase in temperature may be based on, for example, irradiation with electromagnetic waves such as laser light, or Joule heat. The method of increasing the temperature is arbitrary. The temperature of the third film portion 13 does not have to be intentionally increased. In an embodiment, power may be supplied to the resistance member to increase the temperature.
[0019] In one example, the temperature of the first film portion 11, which includes the first layer 11L, changes according to the state of the object to be detected (e.g., gas concentration) surrounding the element portion 10E. The temperature of the first resistive member 11r also changes according to the state of the object to be detected. On the other hand, the temperature of the second film portion 12, which does not include the first layer 11L, is different from the temperature of the first film portion 11. By comparing the signal obtained from the first resistive member 11r with the signal obtained from the second resistive member 12r, the state of the object to be detected that can interact with the first layer 11L can be detected. For example, the concentration of a gas that can react with the first layer 11L can be detected.
[0020] On the other hand, by comparing the signal obtained from the second resistive member 12r with the signal obtained from the third resistive member 13r, the effects of unintended temperature fluctuations are suppressed. According to this embodiment, the object to be detected can be detected with high accuracy. According to this embodiment, a sensor with improved characteristics can be provided.
[0021] As shown in Figure 1, the sensor 110 may further include a detection unit 70. For example, the detection unit 70 includes a first differential circuit 71 and a second differential circuit 72. In the first operation, the first differential circuit 71 is capable of outputting a first difference signal Sd1 corresponding to the first difference between a first signal S1 obtained from a first resistive member 11r and a second signal S2 obtained from a second resistive member 12r.
[0022] In the second operation, the second differential circuit 72 can output a second difference signal Sd2 corresponding to the second difference between the second signal S2 obtained from the second resistor 12r and the third signal S3 obtained from the third resistor 13r.
[0023] The first difference signal Sd1 is variable depending on the concentration of the first gas present around the element 10E. The first gas includes at least one selected from the group consisting of ammonia, methane, and hydrogen. The first gas corresponds to the object to be detected.
[0024] The second difference signal Sd2 can be varied according to the concentration of the second gas present around the element 10E. The second gas includes at least one selected from the group consisting of carbon dioxide, ammonia, methane, and hydrogen.
[0025] The first and second operations described above correspond to the detection operation of the object to be detected. The detection unit 70 increases the temperature of the film during the detection operation.
[0026] For example, as shown in Figure 1, the first film portion 11 may further include a first conductive member 11c. The second film portion 12 may further include a second conductive member 12c. These conductive members function as heaters. For example, the temperature of the film portion rises due to Joule heating.
[0027] As shown in Figure 2, in the first operation described above, the detection unit 70 supplies a first power PV1 to the first conductive member 11c. In the first operation described above, the detection unit 70 supplies a second power PV2 to the second conductive member 12c. Due to this power, the temperature of the first film portion 11 and the temperature of the second film portion 12 rise. In the first film portion 11, the first layer 11L, whose temperature has risen, reacts with the object to be detected. For example, the temperature of the first film portion 11 rises due to the reaction. For example, if the first gas (at least one selected from the group consisting of ammonia, methane, and hydrogen) is present as the gas to be detected, the temperature of the first film portion 11 changes according to the concentration of the first gas.
[0028] For example, the temperature of the first resistive member 11r when the concentration of the first gas is high is higher than the temperature of the first resistive member 11r when the concentration of the first gas is low. The first element 11A functions, for example, as a combustion-type gas sensor (e.g., a catalytic combustion-type gas sensor).
[0029] Meanwhile, in the first operation, the detection unit 70 supplies the second power PV2 to the second conductive member 12c. The temperature of the second film portion 12 rises. The temperature of the second film portion 12 is affected by heat conduction from the detection object present around the second film portion 12. For example, if a gas with high thermal conductivity is present, heat dissipates, and the temperature of the second film portion 12 decreases.
[0030] For example, carbon dioxide and an MoniThe thermal conductivity of gas A is lower than that of air. When the second gas contains these gases, the temperature of the second resistive member 12r when the concentration of the second gas is high is higher than the temperature of the second resistive member 12r when the concentration of the second gas is low.
[0031] For example, the thermal conductivity of hydrogen and methane is higher than that of air. When the second gas contains these gases, the temperature of the second resistive member 12r at a high concentration of the second gas is lower than the temperature of the second resistive member 12r at a low concentration of the second gas.
[0032] By evaluating the second signal S2 obtained from the second resistive member 12r, the temperature of the second resistive member 12r can be detected. This allows for the detection of the concentration of the second gas.
[0033] Power does not need to be supplied to the third film portion 13. The temperature of the third film portion 13 does not change substantially. By detecting the difference between the third signal S3 obtained from the third resistive member 13r included in the third film portion 13 and the second signal S2, for example, the effects of changes in ambient temperature can be suppressed. This enables detection of the target object with higher accuracy.
[0034] In this embodiment, the second element 12A functions as a thermal conduction type gas sensor. The third element 13A functions as a reference sensor.
[0035] As shown in Figure 1, the third film portion 13 may further include a third conductive member 13c. In the second operation described above, the detection unit 70 does not supply power to the third conductive member 13c. By providing the third conductive member 13c, which is not supplied with power, the difference between the heat capacity of the third film portion 13 and the heat capacity of the second film portion 12 can be reduced. The difference can be substantially eliminated. As a result, the third element 13A can function more effectively as a reference sensor.
[0036] For example, in the first reference example, a combustion-type gas sensor and a first reference sensor for the combustion-type gas sensor are provided. In this first reference example, a thermal conduction-type gas sensor and a second reference sensor for the thermal conduction-type gas sensor are provided. In this first reference example, since four sensors are provided, it is difficult to miniaturize the sensors. In contrast, in the embodiment, three sensors are used. This makes miniaturization easy.
[0037] As shown in Figure 1, the first direction D1 from the first region 41 to the first membrane portion 11 is defined as the Z-axis direction. As shown in Figures 2 and 3, one direction perpendicular to the Z-axis direction is defined as the X-axis direction. The direction perpendicular to both the Z-axis direction and the X-axis direction is defined as the Y-axis direction.
[0038] The first region 41, the second region 42, and the third region 43 extend along the XY plane. The first membrane portion 11, the second membrane portion 12, and the third membrane portion 13 extend along the XY plane. The planar shapes of these membrane portions are arbitrary.
[0039] As shown in Figure 1, in the first direction D1, the first resistive member 11r is provided between the first region 41 and the first layer 11L. The first layer 11L is in easy contact with the gas to be detected. Higher sensitivity is easily obtained.
[0040] In the first direction D1, at least a portion of the first layer 11L may overlap with the first resistive member 11r. Temperature changes due to the action of the first layer 11L are efficiently transmitted to the first resistive member 11r.
[0041] As shown in Figure 1, the first film portion 11 may include a first insulating member 11i. The first insulating member 11i is provided around the first resistive member 11r and the first conductive member 11c. The first layer 11L may be provided on top of the first insulating member 11i.
[0042] The second film portion 12 may include a second insulating member 12i. The second insulating member 12i is provided around the second resistive member 12r and the second conductive member 12c. The third film portion 13 may include a third insulating member 13i. The third insulating member 13i is provided around the third resistive member 13r and the third conductive member 13c. The first insulating member 11i, the second insulating member 12i, and the third insulating member 13i may include, for example, at least one selected from the group consisting of silicon and aluminum, and at least one selected from the group consisting of nitrogen and oxygen. These insulating members may include, for example, SiN.
[0043] As shown in Figure 1, the first element 11 A This may include a first connecting portion 11C. One end of the first connecting portion 11C is connected to the first fixing portion 11F. The other end of the first connecting portion 11C is connected to the first membrane portion 11. The first membrane portion 11 may be supported by the first fixing portion 11F via the first connecting portion 11C.
[0044] 2nd element 12 A This may include a second connecting portion 12C. One end of the second connecting portion 12C is connected to the second fixing portion 12F. The other end of the second connecting portion 12C is connected to the second membrane portion 12. The second membrane portion 12 may be supported by the second fixing portion 12F via the second connecting portion 12C.
[0045] Third element 13 A This may include a third connecting portion 13C. One end of the third connecting portion 13C is connected to the third fixing portion 13F. The other end of the third connecting portion 13C is connected to the third membrane portion 13. The third membrane portion 13 may be supported by the third fixing portion 13F via the third connecting portion 13C.
[0046] As shown in Figure 1, the first element 11 A This may include a first other fixing portion 11FA and a first other connecting portion 11CA. The first other fixing portion 11FA is fixed to the first region 41. One end of the first other connecting portion 11CA is connected to the first other fixing portion 11FA. The other end of the first other connecting portion 11CA is connected to the first film portion 11.
[0047] As shown in Figure 1, the second element 12 A This may include a second other fixing portion 12FA and a second other connecting portion 12CA. The second other fixing portion 12FA is fixed to the second region 42. One end of the second other connecting portion 12CA is connected to the second other fixing portion 12FA. The other end of the second other connecting portion 12CA is connected to the second film portion 12.
[0048] As shown in Figure 1, the third element 13 A This may include a third other fixing portion 13FA and a third other connecting portion 13CA. The third other fixing portion 13FA is fixed to the third region 43. One end of the third other connecting portion 13CA is connected to the third other fixing portion 13FA. The other end of the third other connecting portion 13CA is connected to the third membrane portion 13.
[0049] As shown in Figures 2 and 3, the first membrane portion 11 may be further supported by the first support portion 10p and the second support portion 10q. The second membrane portion 12 may be further supported by the second support portion 10q and the third support portion 10r. The third membrane portion 13 may be further supported by the third support portion 10r and the fourth support portion 10s.
[0050] As shown in Figures 2 and 3, the first connection part 11C, the second connection part 12C, the third connection part 13C, the first other connection part 11CA, the second other connection part 12CA, and the third other connection part 13CA may have a meander structure.
[0051] Figure 2 illustrates the planar shapes of the first layer 11L, the first conductive member 11c, the second conductive member 12c, and the third conductive member 13c. The planar shapes of the first conductive member 11c, the second conductive member 12c, and the third conductive member 13c may be meander-shaped.
[0052] Figure 3 illustrates the planar shapes of the first resistor 11r, the second resistor 12r, and the third resistor 13r. The planar shapes of the first resistor 11r, the second resistor 12r, and the third resistor 13r may be meander-shaped.
[0053] As shown in Figure 3, during the detection operation, a detection current may be supplied to the first resistor 11r from the first current source PS1. During the detection operation, a detection current may be supplied to the second resistor 12r from the second current source PS2. During the detection operation, a detection current may be supplied to the third resistor 13r from the third current source PS3. These current sources may be included in the detection unit 70. The voltage across these resistors may change in accordance with the change in the resistance of these resistors.
[0054] Figure 4 is a schematic diagram illustrating the operation of the sensor according to the first embodiment. Figure 4 illustrates the first power PV1 supplied to the first conductive member 11c and the second power PV2 supplied to the second conductive member 12c. In Figure 4, the horizontal axis represents time tm. As already explained, these currents may be supplied by the detection unit 70.
[0055] As shown in Figure 4, the detection unit 70 may supply the first power PV1 to the first conductive member 11c in a pulsed manner. The detection unit 70 may also supply the second power PV2 to the second conductive member 12c in a pulsed manner.
[0056] As shown in Figure 4, the detection unit 70 acquires the signal from the first resistor 11r during the first detection period ST1. The detection unit 70 may perform AD conversion on the signal during the first detection period ST1. The detection unit 70 acquires the signal from the second resistor 12r during the second detection period ST2. The detection unit 70 may perform AD (Analog to Digital) conversion on the signal during the second detection period ST2.
[0057] The detection unit 70 may also detect the difference between the first signal S1 obtained from the first resistor 11r and the second signal S2 obtained from the second resistor 12r during the first detection period ST1. The difference value may also be converted using AD conversion during the first detection period ST1.
[0058] The detection unit 70 may also detect the difference between the second signal S2 obtained from the second resistor 12r and the third signal S3 obtained from the third resistor 13r during the second detection period ST2. The difference value may also be converted using AD conversion during the second detection period ST2.
[0059] As shown in Figure 4, the first power PV1 may be supplied in synchronization with the second power PV2. The first detection period ST1 may be synchronized with the pulse of the first power PV1. The second detection period ST2 may be synchronized with the pulse of the second power PV2.
[0060] As shown in Figure 4, multiple pulses may be supplied. The detection operation may be repeated. The detection unit 70 may perform multiple first operations. The detection unit 70 may perform multiple second operations. The multiple second operations may be performed in synchronization with the multiple first operations.
[0061] Figure 5 is a schematic diagram illustrating the operation of the sensor according to the first embodiment. Figure 5 illustrates the first power PV1 and the second power PV2. In Figure 5, the horizontal axis represents time tm. As shown in Figure 5, these currents may be supplied by the detection unit 70, as previously explained. The detection unit 70 may perform multiple first operations. In this case, the detection unit 70 may change the first power PV1 in the multiple first operations. For example, the pulse height of the first power PV1 in one of the multiple first operations is different from the pulse height of the first power PV1 in another of the multiple first operations. By changing the first power PV1 in the multiple first operations, it becomes easier to separate multiple target gases, for example. For example, it becomes easier to separate and detect substances that burn at low temperatures and substances that burn at high temperatures.
[0062] For example, the detection unit 70 may change the second power PV2 in synchronization with the change in the first power PV1. The detection unit 70 may perform multiple second operations. In this case, the detection unit 70 may change the second power PV2 in the multiple second operations. For example, the pulse height of the second power PV2 in one of the multiple second operations is different from the pulse height of the second power PV2 in another of the multiple second operations.
[0063] Figure 6 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. As shown in Figure 6, in the sensor 111 according to this embodiment, the configurations of the second membrane portion 12 and the third membrane portion 13 differ from those of the sensor 110. The rest of the configuration of the sensor 111 may be the same as that of the sensor 110.
[0064] In the sensor 111, the second film portion 12 includes a second layer 12L. The third film portion 13 includes a third layer 13L. As already explained, the second material of the second layer 12L is different from the first material. The third material of the third layer 13L is the same as the second material. For example, the second material includes Au.
[0065] Because the second material differs from the first material, the combustion behavior relative to the detection target is different. As a result, the first element 11A functions as a combustion-type gas sensor, and the second element 12A functions as a thermal conduction-type gas sensor. The flammability of the first material relative to the detection target is higher than that of the second material relative to the detection target. This allows for effective differentiation of the types of detection targets.
[0066] As shown in Figure 6, the second resistive member 12r may be provided between the second region 42 and the second layer 12L. The third resistive member 13r may be provided between the third region 43 and the third layer 13L. The second layer 12L and the third layer 13L may be provided on the surface of the film portion.
[0067] Figure 7 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. As shown in Figure 7, in the sensor 120 according to this embodiment, the configuration of the element section 10E is different from the configuration of the element section 10E in the sensor 110. The rest of the configuration of the sensor 120 may be the same as that of the sensor 110 or the sensor 111.
[0068] In the sensor 120, the element section 10E includes a first series resistor 11s, a second series resistor 12s, and a third series resistor 13s. The first series resistor 11s is electrically connected in series with the first resistor 11r. The second series resistor 12s is electrically connected in series with the second resistor 12r. The third series resistor 13s is electrically connected in series with the third resistor 13r.
[0069] The first circuit CR1, which includes the first resistor 11r and the first series resistor 11s, is electrically connected in parallel with the second circuit CR2, which includes the second resistor 12r and the second series resistor 12s. The third circuit CR3, which includes the third resistor 13r and the third series resistor 13s, is electrically connected in parallel with the second circuit CR2.
[0070] A bridge circuit is formed by the first resistor 11r, the first series resistor 11s, the second resistor 12r, and the second series resistor 12s. Another bridge circuit is formed by the second resistor 12r, the second series resistor 12s, the third resistor 13r, and the third series resistor 13s. By detecting the signals obtained from these bridge circuits, the target object can be detected with high accuracy.
[0071] As shown in Figure 7, the sensor 120 may further include a detection unit 70. The detection unit 70 may include a first differential circuit 71 and a second differential circuit 72. The element unit 10E may include a first connection point CP1, a second connection point CP2, and a third connection point CP3. The first connection point CP1 is the electrical connection point of the first resistive member 11r and the first series resistive member 11s. The second connection point CP2 is the electrical connection point of the second resistive member 12r and the second series resistive member 12s. The third connection point CP3 is the electrical connection point of the third resistive member 13r and the third series resistive member 13s.
[0072] In the first operation, the detection unit 70 can apply a first detection voltage SV1 to the first circuit CR1 and the second circuit CR2. In the second operation, the detection unit 70 can apply a second detection voltage SV2 to the second circuit CR2 and the third circuit CR3. In the first operation, the first differential circuit 71 of the detection unit 70 can output a first difference signal Sd1 corresponding to the first difference between the first signal S1 obtained from the first connection point CP1 and the second signal S2 obtained from the second connection point CP2. In the second operation, the second differential circuit 72 can output a second difference signal Sd2 corresponding to the second difference between the second signal S2 obtained from the second connection point CP2 and the third signal S3 obtained from the third connection point CP3. Detection using a bridge circuit enables detection with higher accuracy.
[0073] The following describes one example relating to the first series resistor 11s, the second series resistor 12s, and the third series resistor 13s. Figure 8 is a schematic cross-sectional view illustrating a sensor according to the first embodiment. Figures 9 and 10 are schematic plan views illustrating a sensor according to the first embodiment. Figure 8 illustrates the cross-sections along lines B1-B2, B3-B4, and B5-B6 in Figures 9 and 10.
[0074] As shown in Figure 8, for example, the base 40 may further include a fourth region 44, a fifth region 45, and a sixth region 46. The element section 10E further includes a fourth element 14A, a fifth element 15A, and a sixth element 16A. The fourth element 14A is fixed to the fourth region 44. The fifth element 15A is fixed to the fifth region 45. The sixth element 16A is fixed to the sixth region 46. These regions may be continuous or discontinuous with respect to each other.
[0075] The fourth element 14A includes a fourth fixed portion 14F fixed to the fourth region 44 and a fourth film portion 14 supported by the fourth fixed portion 14F. The fourth film portion 14 includes a first series resistor member 11s. For example, a fourth gap g4 may be provided between the fourth region 44 and the fourth film portion 14.
[0076] The fifth element 15A includes a fifth fixing portion 15F fixed to the fifth region 45 and a fifth film portion 15 supported by the fifth fixing portion 15F. The fifth film portion 15 includes a second series resistor member 12s. A fifth gap g5 may be provided between the fifth region 45 and the fifth film portion 15.
[0077] The sixth element 16A includes a sixth fixing portion 16F fixed to the sixth region 46 and a sixth film portion 16 supported by the sixth fixing portion 16F. The sixth film portion 16 includes a third series resistor member 13s. A sixth gap g6 may be provided between the sixth region 46 and the sixth film portion 16.
[0078] As a result of the fourth, fifth, and sixth film sections 14, 15, and 16 described above, their heat capacities become close to those of the first, second, and third film sections 11, 12, and 13. This enables detection with higher accuracy.
[0079] For example, the fourth film portion 14 may further include the fourth conductive member 14c. The fifth film portion 15 may further include the fifth conductive member 15c. The sixth film portion 16 may further include the sixth conductive member 16c.
[0080] As shown in Figure 8, the fourth film portion 14 may include a fourth insulating member 14i. The fourth insulating member 14i is provided around the first series resistive member 11s and the fourth conductive member 14c. The fifth film portion 15 may include a fifth insulating member 15i. The fifth insulating member 15i is provided around the second series resistive member 12s and the fifth conductive member 15c. The sixth film portion 16 may include a sixth insulating member 16i. The sixth insulating member 16i is provided around the third series resistive member 13s and the sixth conductive member 16c.
[0081] 4th element 14 A This may include a fourth connecting portion 14C. One end of the fourth connecting portion 14C is connected to the fourth fixing portion 14F. The other end of the fourth connecting portion 14C is connected to the fourth membrane portion 14. element 15 AThis may include a fifth connecting portion 15C. One end of the fifth connecting portion 15C is connected to the fifth fixing portion 15F. The other end of the fifth connecting portion 15C is connected to the fifth membrane portion 15. element 16 A This may include a sixth connecting portion 16C. One end of the sixth connecting portion 16C is connected to the sixth fixing portion 16F. The other end of the sixth connecting portion 16C is connected to the sixth membrane portion 16.
[0082] As shown in Figure 8, the fourth element 14 A This may include a fourth other fixing portion 14FA and a fourth other connecting portion 14CA. The fourth other fixing portion 14FA is fixed to the fourth region 44. One end of the fourth other connecting portion 14CA is connected to the fourth other fixing portion 14FA. The other end of the fourth other connecting portion 14CA is connected to the fourth membrane portion 14.
[0083] As shown in Figure 8, the fifth element 15 A This may include a fifth other fixing portion 15FA and a fifth other connecting portion 15CA. The fifth other fixing portion 15FA is fixed to the fifth region 45. One end of the fifth other connecting portion 15CA is connected to the fifth other fixing portion 15FA. The other end of the fifth other connecting portion 15CA is connected to the fifth membrane portion 15.
[0084] As shown in Figure 8, the sixth element 16 A This may include a sixth other fixing portion 16FA and a sixth other connecting portion 16CA. The sixth other fixing portion 16FA is fixed to the sixth region 46. One end of the sixth other connecting portion 16CA is connected to the sixth other fixing portion 16FA. The other end of the sixth other connecting portion 16CA is connected to the sixth film portion 16.
[0085] As shown in Figures 9 and 10, the fourth membrane portion 14 may be further supported by the fifth support portion 10t and the sixth support portion 10u. The fifth membrane portion 15 may be further supported by the sixth support portion 10u and the seventh support portion 10v. The sixth membrane portion 16 may be further supported by the seventh support portion 10v and the eighth support portion 10w.
[0086] As shown in Figures 9 and 10, the fourth connection part 14C, the fifth connection part 15C, the sixth connection part 16C, the fourth other connection part 14CA, the fifth other connection part 15CA, and the sixth other connection part 16CA may have a meander structure.
[0087] The first series resistor 11s, the second series resistor 12s, and the third series resistor 13s illustrated in Figures 8 to 10 may be connected to the first resistor 11r, the second resistor 12r, and the third resistor 13r, as illustrated in Figure 7.
[0088] Except for the fourth element 14A, the fifth element 15A, and the sixth element 16A, the configuration of sensor 120 may be the same as that of sensor 110 and sensor 111. For example, in sensor 120, the first film portion 11 may further include a first conductive member 11c (see Figure 1). In sensor 120, the second film portion 12 may further include a second conductive member 12c (see Figure 1). In the first operation, the detection unit 70 may supply first power PV1 to the first conductive member 11c and second power PV2 to the second conductive member 12c. In sensor 120, power does not need to be supplied to the third conductive member 13c.
[0089] The second embodiment relates to a sensor system 210 (see Figure 1 or Figure 7). The sensor system 210 includes the above-mentioned sensors (e.g., sensor 110, sensor 111, or sensor 120) and a communication unit 75. The communication unit 75 is capable of transmitting a signal St1 corresponding to a first difference signal Sd1 and a second difference signal Sd2. The signal St1 may be supplied to an external device by any method, such as wirelessly or wired. For example, detection results can be acquired remotely. For example, control based on the detection results may be performed remotely.
[0090] The embodiments may include the following technical proposals. (Technical proposal 1) A substrate comprising a first region, a second region, and a third region, A first element fixed in the first region, A second element fixed in the second region, A third element fixed in the third region, It comprises an element section including, The first element is, A first fixing part fixed to the first region, The first membrane portion supported by the first fixing portion, Includes, The first film portion includes a first resistive member and a first layer containing a first material, The second element is, A second fixing part fixed to the second region, The second membrane portion supported by the second fixing portion, Includes, The second film portion includes a second resistive member, The third element is, A third fixing part fixed to the third region, The third membrane portion supported by the third fixing portion, Includes, The third film portion includes a third resistive member, The second membrane portion and the third membrane portion satisfy at least one of the first and second conditions, In the first condition described above, the second and third film portions do not include the first layer. In the second condition described above, the second film portion includes a second layer, and the second material of the second layer is different from the first material. In the second condition described above, the third film portion includes a third layer, and the third material of the third layer is the same as the second material, wherein the sensor.
[0091] (Technical proposal 2) The sensor according to Technical Proposal 1, wherein the first material includes at least one selected from the group consisting of Pt and Pd.
[0092] (Technical proposal 3) The second membrane portion includes the second layer, The third membrane portion includes the third layer, The sensor according to Technical Proposal 2, wherein the second material includes Au.
[0093] (Technical proposal 4) Further equipped with a detection unit, The detection unit includes a first differential circuit and a second differential circuit. The first differential circuit is capable of outputting a first difference signal corresponding to the first difference between the first signal obtained from the first resistor and the second signal obtained from the second resistor during the first operation. The sensor according to any one of Technical Proposals 1 to 3, wherein the second differential circuit is capable of outputting a second difference signal corresponding to the second difference between the second signal obtained from the second resistive member and the third signal obtained from the third resistive member in the second operation.
[0094] (Technical proposal 5) The first difference signal can be varied according to the concentration of the first gas present around the element. The sensor according to Technical Proposal 4, wherein the first gas comprises at least one selected from the group consisting of ammonia, methane, and hydrogen.
[0095] (Technical proposal 6) The second difference signal can be varied according to the concentration of the second gas present around the element. The sensor according to Technical Proposal 5, wherein the second gas comprises at least one selected from the group consisting of carbon dioxide, ammonia, methane, and hydrogen.
[0096] (Technical proposal 7) The first film portion further includes a first conductive member, The second film portion further includes a second conductive member, The sensor according to any one of Technical Proposals 4 to 6, wherein the detection unit supplies first power to the first conductive member and second power to the second conductive member in the first operation.
[0097] (Technical proposal 8) The detection unit supplies the first power to the first conductive member in a pulsed manner. The sensor according to technical proposal 7, wherein the detection unit supplies the second power to the second conductive member in a pulsed manner.
[0098] (Technical proposal 9) The detection unit performs a plurality of the first operations, The detection unit changes the first power in the plurality of first operations, as described in Technical Proposal 8.
[0099] (Technical proposal 10) The detection unit performs a plurality of the first operations, The sensor according to proposal 8, wherein the pulse height of the first power in one of the plurality of first operations is different from the pulse height of the first power in another of the plurality of first operations.
[0100] (Technical proposal 11) The third film portion further includes a third conductive member, The sensor according to any one of Technical Proposals 7 to 10, wherein the detection unit does not supply power to the third conductive member in the second operation.
[0101] (Technical proposal 12) The first element is a combustion-type gas sensor, The second element is a thermal conduction type gas sensor, The third element is a reference sensor, which is a sensor described in any one of Technical Proposals 1 to 11.
[0102] (Technical proposal 13) A first gap is provided between the first region and the first membrane portion. A second gap is provided between the second region and the second membrane portion. A sensor according to any one of the technical proposals 1 to 12, wherein a third gap is provided between the third region and the third membrane portion.
[0103] (Technical proposal 14) The sensor according to any one of the technical proposals 1 to 13, wherein at least a portion of the first layer overlaps with the first resistive member in a first direction from the first region to the first film portion.
[0104] (Technical proposal 15) The first resistive member is a sensor according to any one of Technical Proposals 1 to 14, provided between the first region and the first layer.
[0105] (Technical proposal 16) The second resistive member is provided between the second region and the second layer, The third resistive member is provided between the third region and the third layer, and is the sensor according to Technical Proposal 3.
[0106] (Technical proposal 17) The aforementioned element section is A first series resistor is electrically connected in series with the first resistor, A second series resistor electrically connected in series with the second resistor, A third series resistor is electrically connected in series with the third resistor, It further includes, The first circuit, including the first resistor and the first series resistor, is electrically connected in parallel with the second circuit, including the second resistor and the second series resistor. The third circuit, including the third resistor and the third series resistor, is electrically connected in parallel with the second circuit, as described in any one of Technical Proposals 1 to 3.
[0107] (Technical proposal 18) Further equipped with a detection unit, The aforementioned element section is The first connection point of the first resistor and the first series resistor, The second connection point of the second resistor member and the second series resistor member, The third connection point of the third resistor and the third series resistor, Includes, The detection unit is capable of applying a first detection voltage to the first circuit and the second circuit in the first operation. The detection unit is capable of applying a second detection voltage to the second circuit and the third circuit in the second operation. The detection unit includes a first differential circuit and a second differential circuit. The first differential circuit is capable of outputting a first difference signal corresponding to the first difference between the first signal obtained from the first connection point and the second signal obtained from the second connection point during the first operation. The sensor according to Technical Proposal 17, wherein the second differential circuit is capable of outputting a second difference signal corresponding to the second difference between the second signal obtained from the second connection point and the third signal obtained from the third connection point in the second operation.
[0108] (Technical proposal 19) The first film portion further includes a first conductive member, The second film portion further includes a second conductive member, The sensor according to technical proposal 18, wherein the detection unit supplies first power to the first conductive member and second power to the second conductive member in the first operation.
[0109] (Technical proposal 20) The sensor described in Technical Proposal 4 or 18, A communication unit capable of transmitting signals corresponding to the first difference signal and the second difference signal, A sensor system equipped with [unspecified features].
[0110] According to the embodiment, a sensor and sensor system capable of improving characteristics can be provided.
[0111] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configuration of each element, such as regions, element parts, fixing members, connecting members, film parts, resistive members, conductive members, and control units included in sensors and sensor systems, is included within the scope of the present invention as long as those skilled in the art can appropriately select from the known range to implement the present invention and obtain similar effects.
[0112] Combinations of two or more elements from any of the specific examples, to the extent technically feasible, are also included within the scope of the present invention, insofar as they encompass the gist of the invention.
[0113] Furthermore, all sensors and sensor systems that a person skilled in the art can design and implement based on the sensors and sensor systems described above as embodiments of the present invention, insofar as they encompass the gist of the present invention, also fall within the scope of the present invention.
[0114] Furthermore, within the scope of the concept of the present invention, a person skilled in the art could conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention.
[0115] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]
[0116] 10E: Element part, 10p~10w: 1st~8th support part, 11~16: 1st~6th film part, 11A~16A: 1st~6th element, 11C~16C: 1st~6th connection part, 11CA~16CA: 1st~6th other connection part, 11F~16F: 1st~6th fixing part, 11FA~16FA: 1st~6th other fixing part, 11L~13L: 1st~3rd layer, 11c~16c: 1st~6th conductive member, 11i~16i: 1st~6th insulating member, 11r~13r: 1st~3rd resistive member, 11s~13s: 1st~3rd series resistive member, 40: Substrate, 41~46: 1st~6th region, 70: Detection part, 71, 72: First and second differential circuits, 75: Communication section, 110, 111, 120: Sensors, 210: Sensor system, CP1~CP3: First to third connection points, CR1~CR3: First to third circuits, D1: First direction, PS1~PS3: First to third current sources, PV1, PV2: First and second power, S1~S3: First to third signals, ST1, ST2: First and second detection periods, SV1, SV2: First and second detection voltages, Sd1, Sd2: First and second difference signals, St1: Signal, g1~g6: First to sixth gaps
Claims
1. A substrate comprising a first region, a second region and a third region, A first element fixed in the first region, A second element fixed in the second region, A third element fixed in the third region, It comprises an element section including, The first element is, The first fixing part fixed in the first region, The first membrane portion supported by the first fixing portion, Includes, The first film portion includes a first resistive member and a first layer containing a first material, The second element is, A second fixing part fixed to the second region, The second membrane portion supported by the second fixing portion, Includes, The second film portion includes a second resistive member, The third element is, A third fixing part fixed to the third region, The third membrane portion supported by the third fixing portion, Includes, The third film portion includes a third resistive member, The second membrane portion and the third membrane portion satisfy at least one of the first and second conditions, In the first condition, the second and third film portions do not include the first layer. In the second condition described above, the second film portion includes a second layer, and the second material of the second layer is different from the first material. In the second condition described above, the third film portion includes a third layer, and the third material of the third layer is the same as the second material described above. Further equipped with a detection unit, The detection unit includes a first differential circuit and a second differential circuit. The first differential circuit is capable of outputting a first difference signal corresponding to the first difference between the first signal obtained from the first resistive member and the second signal obtained from the second resistive member during the first operation. The second differential circuit is a sensor capable of outputting a second difference signal corresponding to the second difference between the second signal obtained from the second resistive member and the third signal obtained from the third resistive member during the second operation.
2. The sensor according to claim 1, wherein the first material comprises at least one selected from the group consisting of Pt and Pd.
3. The first difference signal can be varied according to the concentration of the first gas present around the element. The sensor according to claim 1, wherein the first gas comprises at least one selected from the group consisting of ammonia, methane, and hydrogen.
4. The first film portion further includes a first conductive member, The second film portion further includes a second conductive member, The sensor according to claim 1, wherein the detection unit supplies first power to the first conductive member and second power to the second conductive member in the first operation.
5. The detection unit supplies the first power to the first conductive member in a pulsed manner. The sensor according to claim 4, wherein the detection unit supplies the second power to the second conductive member in a pulsed manner.
6. The detection unit performs a plurality of the first operations, The sensor according to claim 5, wherein the detection unit changes the first power in the plurality of first operations.
7. A substrate comprising a first region, a second region and a third region, A first element fixed in the first region, A second element fixed in the second region, A third element fixed in the third region, It comprises an element section including, The first element is, The first fixing part fixed in the first region, The first membrane portion supported by the first fixing portion, Includes, The first film portion includes a first resistive member and a first layer containing a first material, The second element is, A second fixing part fixed to the second region, The second membrane portion supported by the second fixing portion, Includes, The second film portion includes a second resistive member, The third element is, A third fixing part fixed to the third region, The third membrane portion supported by the third fixing portion, Includes, The third film portion includes a third resistive member, The second membrane portion and the third membrane portion satisfy at least one of the first and second conditions, In the first condition, the second and third film portions do not include the first layer. In the second condition described above, the second film portion includes a second layer, and the second material of the second layer is different from the first material. In the second condition described above, the third film portion includes a third layer, and the third material of the third layer is the same as the second material described above. The aforementioned element section is A first series resistor is electrically connected in series with the first resistor, A second series resistor is electrically connected in series with the second resistor, A third series resistor electrically connected in series with the third resistor, It further includes, The first circuit, which includes the first resistor and the first series resistor, is electrically connected in parallel with the second circuit, which includes the second resistor and the second series resistor. The third circuit, including the third resistor and the third series resistor, is electrically connected in parallel with the second circuit and is a sensor.
8. Further equipped with a detection unit, The aforementioned element section is The first connection point of the first resistor and the first series resistor, The second connection point of the second resistor and the second series resistor, The third connection point of the third resistor and the third series resistor, Includes, The detection unit is capable of applying a first detection voltage to the first circuit and the second circuit in the first operation. The detection unit is capable of applying a second detection voltage to the second circuit and the third circuit in the second operation. The detection unit includes a first differential circuit and a second differential circuit. The first differential circuit is capable of outputting a first difference signal corresponding to the first difference between the first signal obtained from the first connection point and the second signal obtained from the second connection point during the first operation. The sensor according to claim 7, wherein the second differential circuit is capable of outputting a second difference signal corresponding to the second difference between the second signal obtained from the second connection point and the third signal obtained from the third connection point in the second operation.
9. The sensor according to claim 1, A communication unit capable of transmitting signals corresponding to the first difference signal and the second difference signal, A sensor system equipped with [unspecified features].