JP2017211252A - Sensor substrate and sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor substrate and a sensor device which can determine the presence or absence and a position of disconnection.SOLUTION: A sensor substrate includes: an insulating substrate; a pair of positive and negative detection electrodes provided on one surface of the insulating substrate; equal to or more than one through conductor which is embedded in the insulating substrate, and whose upper surface and at least one of lower surfaces of the positive and negative detection electrodes are connected together; and inner layer wires which are embedded in the insulating substrate, and which correspond to the through conductor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sensor substrate and a sensor device including an insulating substrate and electrodes provided on the insulating substrate.

  A DPF (Diesel Particulate Filter) is installed to collect particulate matter (PM) mainly composed of soot contained in exhaust gas from automobiles, etc., and abnormalities such as DPF are detected. As a PM detection sensor, a particulate matter detection device comprising an insulating substrate made of a ceramic sintered body such as an aluminum oxide sintered body, and a detection electrode formed by thick film printing (screen printing) on the surface of the insulating substrate Is disclosed (for example, Patent Document 1).

  By the way, in the exhaust gas sensor or the like, there are cases where the resistance value and the electrode value between the detection electrodes do not change. There are two cases: the case where there is no accumulation of the detection object and no leakage current flows and the above change does not occur, or the case where the above change does not occur because the detection electrode in the sensor is disconnected.

  Therefore, while detecting the content of the detected object in the exhaust gas or the like by the change of the resistance value and the current value caused by the detected object contained in the exhaust gas being deposited between the pair of detection electrodes, A technique for performing disconnection determination is disclosed (for example, Patent Document 2).

JP 2012-47596 A JP 2014-32063 A

  However, in the particulate matter detection sensor of Patent Document 2 described above, the detection electrodes (both positive and negative electrodes) on the surface of the sensor element are formed in a closed loop. There was a problem that the size increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sensor substrate capable of detecting disconnection of a detection electrode without increasing the element size, and a sensor device using the same. is there.

  A sensor substrate according to one aspect of the present invention includes an insulating substrate, a pair of positive and negative detection electrodes disposed on one surface of the insulating substrate, and one or more through conductors embedded in the insulating substrate, One or more through conductors in which the lower surface of at least one of the positive electrode and the negative electrode of the detection electrode and the upper surface of the through conductor are joined, and an inner layer wiring corresponding to the through conductor embedded in the insulating substrate. .

  The sensor device according to one aspect of the present invention includes the sensor substrate, a positive electrode or a negative electrode in the pair of positive and negative detection electrodes, the through conductor joined to the positive electrode or the negative electrode, and an inner layer corresponding to the through conductor. A failure detection unit that determines the presence or absence of a broken portion in a circuit including wiring, and a power source that supplies power to the circuit.

  According to the sensor substrate of one aspect of the present invention, since the through conductor and the inner layer wiring are provided in the insulating substrate to enable the configuration of the circuit including the positive electrode or the negative electrode of the detection electrode, the element size is not increased. It is possible to detect disconnection in the detection electrode.

  In addition, according to the sensor device of one aspect of the present invention, since the sensor substrate is provided, a sensor device capable of detecting disconnection in the detection electrode can be realized.

FIG. 1A is a top view of the sensor substrate according to the first embodiment. FIG. 1B is a diagram illustrating a configuration of wiring in the second layer of the sensor substrate according to the first embodiment. FIG. 1C is a diagram illustrating a wiring configuration in the third layer of the sensor substrate according to the first embodiment. FIG. 1D is a drawing showing the configuration of the heating electrode in the fourth layer of the sensor substrate according to the first embodiment. FIG. 1E is a rear view of the sensor substrate according to the first embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. It is the figure which defined the area used as the object of disconnection detection in the sensor apparatus concerning a 1st this embodiment. It is a block diagram which shows the function structure of a sensor apparatus provided with the sensor board | substrate which concerns on 1st Embodiment. It is a flowchart which shows the algorithm of the disconnection determination in the sensor apparatus which concerns on 1st Embodiment. FIG. 6A is a top view of the sensor substrate according to the second embodiment. FIG. 6B is a diagram illustrating a configuration of wiring in the second layer of the sensor substrate according to the second embodiment. FIG. 6C is a drawing showing the configuration of the wiring in the third layer of the sensor substrate according to the second embodiment. FIG. 6D is a drawing showing the configuration of the heating electrode in the fourth layer of the sensor substrate according to the second embodiment. FIG. 6E is a rear view of the sensor substrate according to the second embodiment. FIG. 7 is a cross-sectional view taken along a cutting plane line BB in FIG. 6. It is a flowchart which shows the algorithm of the disconnection determination in the sensor apparatus which concerns on 2nd Embodiment.

  A sensor substrate and a sensor device according to embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the upper and lower sides are distinguished from each other like the upper surface, but this is for convenience and does not limit the upper and lower sides when the sensor substrate or the like is actually used.

(First embodiment)
FIGS. 1A to 1E are drawings showing an example of the configuration of a sensor substrate having a multilayer structure according to the first embodiment of the present invention. FIG. 1A is a top view of the sensor substrate 1, FIG. 1B is a drawing showing the configuration of wiring in the second layer of the sensor substrate 1, and FIG. 1D is a diagram showing the configuration of the heating electrode in the fourth layer of the sensor substrate 1, and FIG. 1E is a diagram showing the configuration of the wiring in the third layer. It is a back view. FIG. 2 is a cross-sectional view taken along a cutting plane line AA in FIG.

  The sensor substrate 1 is used in a sensor device that detects particulate matter (PM) in exhaust gas of, for example, a diesel engine vehicle or a gasoline engine vehicle (for example, disposed in an exhaust gas exhaust passage of an automobile). ), An insulating substrate 2, a pair of positive and negative detection electrodes 3, 4 disposed on one surface of the insulating substrate 2, vias 5a, 5b disposed on one detection electrode 3, and detection of the other Vias 5c and 5d disposed in the electrode 4 and inner layer wirings 7a to 7d corresponding to the vias 5a to 5d embedded in the insulating substrate 2 are provided.

  A feature of the sensor substrate 1 is that it is possible to detect disconnection in the detection electrode without increasing the element size by adopting it in the sensor device.

  As shown in FIGS. 1 (a) to 1 (e) and FIG. 2, the first layer, the second layer, or the third layer of the sensor substrate 1 has vias 5a to 5 disposed on the detection electrodes 3 and 4, respectively. Inner layer wirings 7a to 7d, connection terminals 6a to 6d and internal wirings 6e to 6h corresponding to 5d are embedded or disposed. In addition, a heating electrode 8 is embedded in the fourth layer of the sensor substrate 1, and internal wirings 8a and 8b and connection pads 9a corresponding to the positive electrode and the negative electrode of the heating electrode 8 are embedded in the fourth layer or the fifth layer. 9b.

  In the present embodiment, the detection electrodes 3 and 4 are, for example, comb-shaped electrodes disposed on the surface (first surface 2a) of the insulating substrate 2. For example, the detection electrode 3 is a positive electrode and the detection electrode 4 is a negative electrode. A DC voltage (for example, 50 [V]) is applied from an external power source (not shown).

  The vias 5 a to 5 d are columnar through conductors, and any upper surface is joined to the lower surface of the detection electrode 3 or 4. The via 5a or 5b is connected to the outside via the second-layer inner layer wiring 7a or 7b. The via 5c or 5d is connected to the outside via the third-layer inner layer wiring 7c or 7d.

  As described above, the vias 5 a to 5 d are embedded in the insulating substrate 2 and joined to the detection electrodes 3 and 4. Therefore, the vias 5 a to 5 d constitute a circuit used for detecting disconnection of the detection electrodes 3 and 4 and also have a function of fixing the detection electrodes 3 and 4 to the insulating substrate 2.

  The heating electrode 8 is connected to an external (not shown) DC power source (for example, 20 [V]) via the connection pads 9a and 9b. The heating electrode 8 is heated to, for example, 700 [° C.] to decompose and remove the particulate matter (Particulate Matter: PM) adhering to the first surface 2a.

  The insulating substrate 2 is, for example, a flat plate shape such as a square plate shape, and is a base portion for providing a pair of detection electrodes and a pair of detection electrodes and a heating electrode in an electrically insulated manner. This insulating substrate 2 is a ceramic sintered body such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a glass ceramic sintered body, a zirconia ceramic (zirconium oxide sintered body), or the like. Is formed by. The insulating substrate 2 is laminated with a plurality of insulating layers made of such a ceramic sintered body.

  If the insulating substrate 2 is formed by laminating a plurality of insulating layers made of an aluminum oxide sintered body, for example, the insulating substrate 2 can be manufactured by the following method.

First, raw material powders such as silicon oxide (SiO ₂ ), magnesium oxide (MgO), and manganese oxide (Mn ₂ O ₃ ) are added as sintering aids to aluminum oxide (Al ₂ O ₃ ) powder that becomes inorganic particles. Further, an appropriate binder, solvent and plasticizer are added, and then the mixture is kneaded to form a slurry. After that, a ceramic green sheet is obtained by forming into a sheet shape by a conventionally known doctor blade method or calendar roll method, etc., and a suitable punching process is performed on the ceramic green sheet, and a plurality of layers are laminated as necessary. It is manufactured by firing at (about 1300 to 1600 ° C.).

  Insulating substrate 2 may include a crystal phase containing alumina and manganese and a glass phase containing manganese. In addition to alumina, the crystal phase may contain various ceramics such as mullite, zirconia, aluminum nitride, or glass ceramics.

The glass phase is an amorphous phase containing at least Mn ₂ O ₃ and may further contain one or more oxides selected from Si, Mg, Ca, Sr, B, Nb, Cr and Co. The glass phase is preferably an amorphous phase containing Mn ₂ O ₃ , SiO ₂ and MgO.

  Since the glass phase containing manganese has good wettability with respect to the alumina crystal phase, in the heat treatment after firing, the glass phase oozes out to the surface layer of the insulating substrate 2 so as to cover the crystal particle surface, and most of the glass phase It is considered to exist on the surface layer.

  Thus, the presence of the glass phase containing manganese so as to be exposed on the first surface 2a of the insulating substrate 2 makes it possible to obtain the insulating substrate 2 with few defects serving as crack starting points and less likely to cause cracking. Since the glass phase has a lower Young's modulus than the crystal phase containing alumina, for example, when it comes into contact with exhaust gas, the thermal shock due to the attachment of water droplets to the insulating substrate 2 is mitigated, and the occurrence of cracks can be suppressed.

  The pair of positive and negative detection electrodes 3 and 4 are electrodes for detecting particulate matter such as soot in an environment where the sensor substrate 1 is installed in the sensor device. When particulate matter such as soot adheres between the detection electrodes 3-4, the electrical resistance between the pair of detection electrodes changes, and the leakage current flowing between the electrodes changes. By detecting the change in the leakage current, it is possible to acquire information on the particulate matter existing between the pair of detection electrodes.

The metal material used for the detection electrodes 3 and 4 is preferably one having excellent oxidation resistance in a high temperature environment. For example, platinum or a material on which a passive film containing an oxide is formed can be used. As a metal material on which a passive film containing an oxide is formed on the surface, for example, an Fe—Ni—Cr—Ti—Al alloy or MoSi ₂ metal can be used.

  The thickness of the passive film is set to, for example, about 0.1 to 5 μm. If it is this thickness, the surface part of via | veer 5a-5d is effectively covered with a passive film, and the possibility that the whole or most part will oxidize is reduced effectively.

  It is preferable that about 90% of the surface portions of the detection electrodes 3 and 4 include a passive film in terms of area ratio. In other words, it is preferable that 90% or more of the exposed surfaces of the detection electrodes 3 and 4 are covered with the passive film. Thereby, possibility that oxidation will advance to the whole detection electrodes 3 and 4 will be reduced effectively.

  Further, the surface portions of the detection electrodes 3 and 4 more preferably include a passive film as a whole. In other words, it is more preferable that the entire exposed surfaces of the detection electrodes 3 and 4 are covered with the passive film. Thereby, possibility that oxidation will advance to the whole detection electrodes 3 and 4 will be reduced more effectively.

  Further, a metal plating layer may be applied to the exposed surfaces of the detection electrodes 3 and 4 by electroplating or electroless plating. The metal plating layer is made of a metal having excellent corrosion resistance such as nickel, copper, gold or silver and connectivity with the connection member. For example, a nickel plating layer having a thickness of about 0.5 to 10 μm and 0.1 to A gold plating layer of about 3 μm, or a nickel plating layer of about 1 to 10 μm in thickness and a silver plating layer of about 0.1 to 1 μm are sequentially deposited. Thereby, it can suppress effectively that the detection electrodes 3 and 4 corrode. Moreover, you may interpose the metal plating layer which consists of metals other than the above, for example, a palladium plating layer.

  The vias 5a to 5d are, for example, columnar and have a diameter of 50 μm. For the vias 5a to 5d, the insulating substrate 2 including the detection electrodes 3 and 4 can be manufactured by using the same manufacturing method as the via in the conventional circuit board.

  The inner layer wirings 7a to 7d are formed inside the insulating substrate 2, and are electrically connected to the detection electrodes 3 and 4 disposed on the first surface 2a of the insulating substrate 2 via the vias 5a to 5d. It is connected to the outside through the internal wirings 6e to 6h and the connection terminals 6a to 6d. The inner layer wirings 7a to 7d are embedded in different layers as appropriate in order to secure a wiring space corresponding to the vias 5a to 5d.

  The heating electrode 8 is made of, for example, the same metal material as that of the detection electrodes 3 and 4, and in order to generate heat particularly efficiently, a material containing iron, titanium, chromium, silicon or the like having a high electrical resistivity can be used. Further, the heating electrode 8 may include a metal that is not easily oxidized, such as platinum or an Fe—Ni—Cr alloy, as a main component.

  The metal material of the heating electrode 8 is, for example, contained in the heating electrode 8 by about 80% by mass or more, and is a main component of the heating electrode 8. The heating electrode 8 may contain an inorganic component such as glass or ceramic in addition to the metal material. These inorganic components are components for adjusting the firing shrinkage when the heating electrode 8 is formed by simultaneous firing with the insulating substrate 2, for example.

  The detection electrodes 3 and 4, the vias 5 a to 5 d, the connection terminals 6 a to 6 d, the internal wirings 6 e to 6 h, the inner layer wirings 7 a to 7 d, and the heating electrode 8 are prepared by, for example, kneading the above metal material powder with an organic solvent and a binder. A metal paste is produced, and this metal paste is applied or embedded in a predetermined pattern on the surface and through-hole of the ceramic green sheet to be the insulating substrate 2. The metal paste is applied or embedded by a printing method such as a screen printing method. In this way, a plurality of ceramic green sheets are laminated so as to cover the print patterns to be the detection electrodes 3 and 4, the vias 5 a to 5 d, the connection terminals 6 a to 6 d, the internal wirings 6 e to 6 h, the inner layer wirings 7 a to 7 d and the heating electrode 8. These metal paste and ceramic green sheet are fired simultaneously.

  Next, the operation of the sensor device 10 according to the present embodiment using the sensor substrate 1 configured as described above will be described.

  FIG. 3 is a diagram in which a section that is a target of disconnection detection in the sensor device according to the present embodiment is defined. In the illustration of FIG. 3, two vias 5 a and 5 b are connected to the detection electrode 3, and two vias 5 c and 5 d are connected to the detection electrode 4. Therefore, in the present embodiment, the detection electrode 3 is divided into a section 3a, a section 3b, and a section 3c. On the other hand, the detection electrode 4 is also divided into a section 4a, a section 4b, and a section 4c. Note that the number of vias connected to each detection electrode and the number of defined sections are not limited to the above, and more vias may be connected to each detection electrode to define more sections.

  FIG. 4 is a block diagram illustrating a functional configuration of a sensor device including the sensor substrate according to the first embodiment. As shown in FIG. 4, the sensor device 10 of the present embodiment includes the sensor substrate 1, the overall control unit 20, the wrinkle detection unit 30, and the first failure detection unit 41 to the fourth failure detection unit 44, and heater control The unit 50, the temperature detection unit 60, and the display unit 70 may be further provided.

  The overall control unit 20 is a microcomputer, for example, and controls the entire sensor device 10. Specifically, the overall control unit 20 controls the soot detection unit 30, the first failure detection unit 41 to the fourth failure detection unit 44, and the heater control unit 50 based on a program defined in advance. Furthermore, the overall control unit 20 specifies the presence or absence of disconnection in the detection electrodes 3 and 4 and the section where the disconnection occurs based on the results of the continuity test detected by the first failure detection unit 41 to the fourth failure detection unit 44. To do.

  The hail detection unit 30 applies a predetermined voltage (for example, 50 [V]) supplied from an external DC power source (not shown) between the detection electrodes 3-4 according to an instruction from the overall control unit 20. Then, the particulate matter between the electrodes is detected. Specifically, the current value flowing between the detection electrodes 3-4 is measured.

  The first failure detection unit 41 is connected to an external DC power source (not shown) in a circuit including the sections 3a and 3b, the via 5a, the inner layer wiring 7a, the internal wiring 6e, and the connection terminal 6a in the detection electrode 3 according to an instruction from the overall control unit 20. A predetermined voltage (for example, 50 [V]) supplied from (1) is applied, and the continuity test of the circuit is performed. Specifically, the presence / absence of conduction is determined based on the current flowing through the resistor included in the first failure detection unit 41.

  Similar to the first failure detection unit 41, the second failure detection unit 42, in response to an instruction from the overall control unit 20, sections 3a and 3c, vias 5b, inner layer wiring 7b, internal wiring 6f, and connection terminals 6b in the detection electrode 3. A continuity test is performed on a circuit including the continuity test to determine the presence or absence of continuity.

  Similarly, the third failure detection unit 43 is a circuit including the sections 4a and 4b, the via 5c, the inner layer wiring 7c, the internal wiring 6g, and the connection terminal 6c in the detection electrode 4, and the fourth failure detection unit 44 is the detection electrode. 4, a continuity test is performed on the circuits including sections 4a and 4c, via 5d, inner layer wiring 7d, internal wiring 6h, and connection terminal 6d.

  The heater control unit 50 includes, for example, a DC power supply of 20 [V], and performs control for heating the heating electrode 8 to a predetermined temperature in accordance with an instruction from the overall control unit 20.

  The temperature detection unit 60 includes a temperature sensor and measures the temperature of the heating electrode 8 according to an instruction to the heater control unit 40.

  The display unit 70 is, for example, a liquid crystal display device. Information on the results of the continuity tests performed in the first failure detection unit 41 to the fourth failure detection unit 44 according to an instruction from the overall control unit 20 and the overall control unit 20 The result of disconnection judgment is displayed.

  FIG. 5 is a flowchart illustrating an algorithm for determining whether or not there is a disconnection with respect to the detection electrodes 3 and 4 and for specifying a disconnection section in the sensor device according to the first embodiment.

  First, according to an instruction from the overall control unit 20, the first failure detection unit 41 to the fourth failure detection unit 44 perform continuity tests periodically (for example, every 10 minutes) for each circuit including the vias 5a to 5d. Is executed (S100).

  As a result of the continuity test, first, when it is determined that the circuit including the via 5a is not conductive (No in S102) and it is determined that the circuit including the via 5b is also not conductive (No in S104). When it is determined that the circuit including the via 5b is conductive (Yes in S104), it is determined that there is a disconnection in the section 3b (S108). ). On the other hand, if it is determined that the circuit including the via 5a is conductive (Yes in S102) and it is determined that the circuit including the via 5b is not conductive (No in S110), “There is a disconnection in the section 3c”. (S126).

  Next, it is determined that the circuit including the via 5a and the circuit including the via 5b are conductive (Yes in S102 and S110), and it is determined that the circuit including the via 5c is not conductive (No in S112). If it is determined that the circuit including the via 5d is not conductive (No in S120), it is determined that “the circuit 4a is disconnected” (S124), and the circuit including the via 5d is conductive. If it is determined (Yes in S120), it is determined that “disconnection occurs in section 4b” (S122). On the other hand, if it is determined that the circuit including the via 5c is conductive (Yes in S112) and it is determined that the circuit including the via 5d is not conductive (No in S114), “there is a disconnection in the section 4c”. (S116), and when it is determined that all the circuits including the vias 5a to 5d are conducting (Yes in S102, S110, S112, and S114), it is determined that there is no disconnection (S118). ).

The functions of the first failure detection unit 41 to the fourth failure detection unit 44 are integrated into the first failure detection unit, and each circuit is sequentially switched by a switch provided in the first failure detection unit, so that each circuit is changed. You may comprise so that a continuity test may be implemented. Further, the sensor device has a function of calculating a failure rate in the sensor board based on the number of vias provided in the sensor board (that is, the number of circuits to be subjected to the continuity test) and the number of the conducted circuits. It is good.
(Second Embodiment)

  6A to 6E are drawings showing an example of the configuration of a sensor substrate having a multilayer structure according to the second embodiment of the present invention. 6A is a top view of the sensor substrate 11, FIG. 6B is a drawing showing the configuration of the second layer wiring of the sensor substrate 11, and FIG. 6C is the sensor substrate 11. FIG. 6D is a diagram showing the configuration of the heating electrode of the fourth layer of the sensor substrate 11, and FIG. 6E is the diagram of the sensor substrate 11. It is a back view. FIG. 7 is a cross-sectional view taken along a cutting plane line BB in FIG.

  A feature of the sensor substrate 11 is that, by adopting it in the sensor device, it is possible to determine the presence or absence of disconnection in each of the detection electrodes 13 and 14 with a simple configuration.

  As shown in FIGS. 6A to 6E and FIG. 7, vias 15 a to 15 d disposed in the detection electrodes 13 and 14 are formed in the first layer, the second layer, or the third layer of the sensor substrate 11. Inner layer wirings 17a and 17c, connection terminals 16a and 16c, and internal wirings 16e and 16g corresponding to are embedded or disposed. Further, the heating layer 18 is embedded in the fourth layer of the sensor substrate 11, and the internal wirings 18a and 18b corresponding to the positive electrode and the negative electrode of the heating electrode 18 and the connection pad 19a are embedded in the fourth layer or the fifth layer. , 19b are disposed.

  In the present embodiment, the detection electrodes 13 and 14 are comb-shaped electrodes as in the first embodiment. The detection electrode 13 is a positive electrode, the detection electrode 14 is a negative electrode, and an external power source (not shown). A DC voltage (for example, 50 [V]) is applied.

  The vias 15 a to 15 d are, for example, columnar through conductors, and any upper surface is exposed to the first surface 12 a of the insulating substrate 12 and is in contact with the lower surface of the detection electrode 13 or 14. Similar to the first embodiment, the vias 15a and 15b are connected to the outside via the second-layer inner layer wiring 17a and the like. The vias 15c and 15d are connected to the outside via a third layer inner layer wiring 17c and the like.

  The sensor substrate 11 in the present embodiment is the same as the first embodiment except that the vias 15a and 15b are commonly connected to the inner layer wiring 17a and the vias 15c and 15d are commonly connected to the inner layer wiring 17c. The sensor device 10 can be diverted (specifically, only the first failure detection unit 41 and the third failure detection unit 43 are operated, etc.) because the configuration is the same as that of the sensor substrate 1 of the embodiment. .

  FIG. 8 is a flowchart illustrating an algorithm for determining the presence or absence of disconnection of the detection electrodes 13 and 14 in the sensor device according to the second embodiment.

  First, a continuity test is performed periodically (for example, every 10 minutes) for each of the vias 15a and 15b and each of the vias 15c and 15d according to an instruction from the overall control unit 20 (S200).

  As a result of the continuity test, first, when it is determined that the circuit including the vias 15a and 15b is not conductive (No in S202), it is determined that "the positive detection electrode is disconnected" (S206). On the other hand, when it is determined that the circuit including the vias 15c and 15d is not conductive (No in S204), it is determined that “the detection electrode of the negative electrode is disconnected” (S210). If it is determined that all the circuits including the vias 15a and 15b and the vias 15c and 15d are conducting (Yes in S202 and S204), it is determined that there is no disconnection (S208).

1, 11 Sensor substrate 2, 12 Insulating substrate 2a, 12a First surface 3, 4 Detection electrodes 5a, 5b, 5c, 5d Vias 6a, 6b, 6c, 6d Connection terminals 6e, 6f, 6g, 6h Internal wiring 7a, 7b 7c, 7d Inner layer wiring 8, 18 Heating electrodes 8a, 8b Internal wiring 9a, 9b Connection pad 10 Sensor device 13, 14 Detection electrodes 15a, 15b, 15c, 15d Vias 16a, 16b, 16c, 16d Connection terminals 16e, 16f, 16g, 16h Internal wirings 17a, 17b, 17c, 17d Inner layer wirings 18a, 18b Internal wirings 19a, 19b Connection pad 20 Overall control unit 30 煤 detection unit 41 First failure detection unit 42 Second failure detection unit 43 Third failure detection unit 44 4th failure detection part 50 heater control part 60 temperature detection part 70 display part

Claims (6)

An insulating substrate;
A pair of positive and negative detection electrodes disposed on one surface of the insulating substrate;
One or more through conductors embedded in the insulating substrate, wherein at least one lower conductor of the positive electrode and the negative electrode of the detection electrode and the upper surface of the through conductor are joined,
An inner layer wiring corresponding to the through conductor embedded in the insulating substrate.   The sensor substrate according to claim 1, wherein a plurality of through conductors are bonded to the lower surfaces of the positive electrode and the negative electrode of the pair of positive and negative detection electrodes, respectively. The pair of positive and negative detection electrodes are comb electrodes,
The penetrating conductor is joined to the tip or base of each electrode tooth of the positive electrode and the negative electrode of the detection electrode,
The sensor substrate according to claim 2, wherein the inner layer wiring is connected in a one-to-one correspondence for each through conductor. The pair of positive and negative detection electrodes are comb electrodes,
The penetrating conductor is joined to the tip or base of each electrode tooth of the positive electrode and the negative electrode of the detection electrode,
The sensor substrate according to claim 2, wherein the inner layer wiring includes an inner layer wiring common to the through conductors related to the positive electrode and an inner layer wiring common to the through conductors related to the negative electrode. The sensor substrate according to any one of claims 1 to 4,
Fault detection for determining the presence or absence of a disconnection point in a circuit including a positive electrode or a negative electrode in the pair of positive and negative detection electrodes, the through conductor joined to the positive electrode or the negative electrode, and an inner layer wiring corresponding to the through conductor And
And a power supply for supplying power to the circuit. A plurality of through conductors are respectively joined to the lower surfaces of the positive electrode and the negative electrode of the pair of positive and negative detection electrodes,
The failure detection unit is
In the positive or negative polarity of the pair of positive and negative detection electrodes, the determination result of the presence or absence of a disconnection location in the circuit related to one through conductor and the determination result of the presence or absence of a disconnection location in the circuit related to another through conductor 6. The sensor device according to claim 5, wherein a section in which the positive electrode or the negative electrode is disconnected is specified.

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