JP7205770B2 - Composite sensor - Google Patents

Description

The present invention relates to a combined sensor having heat flow sensor function and temperature sensor function in a single device.

As a sensor capable of simultaneously detecting heat flow and temperature, conventionally, for example, Non-Patent Document 1 and Patent Documents 1 and 2 disclose a thin heat flow sensor with a built-in thermocouple. This heat flow sensor has a thermoelectric chip for heat flow measurement and a thermocouple for temperature measurement mounted on a polyimide substrate. Therefore, a π-type method is adopted in which the voltage is measured by connecting in series. This thermoelectric chip utilizes the Seebeck effect, in which a temperature difference occurs in the thickness direction of the thermoelectric semiconductor along the heat flow and voltage is generated. Voltage is generated in the direction of the temperature difference, that is, in the same direction as the heat flow. .

JP 2017-211270 A JP 2017-211271 A

"Heat flow sensor", [online], Denso Corporation, [searched on February 10, 2019], Internet (URL: https://energyeye.com)

The following problems remain in the above conventional technique.
That is, there is a demand for a further reduction in the thickness of the composite sensor including the heat flow sensor. If the thickness of the thermoelectric semiconductor along the line is made thin, the temperature difference becomes small and the detected voltage becomes small.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a composite sensor that has not only a heat flow sensor function but also a temperature sensor function and that can be made thinner.

In order to solve the above problems, the present invention employs the following configurations. That is, a composite sensor according to a first aspect of the present invention includes an insulating base material, a thin film thermistor section formed on the base material, and a pair of thin film thermistor sections formed facing at least one of the top and bottom of the thin film thermistor section. and a plurality of anomalous Nernstian material films formed on the base material, extending in the same direction, and arranged parallel to each other in a planar direction of the base material to obtain an anomalous Nernst effect. and a connection wiring electrically connecting the plurality of abnormal Nernst material films in series.

Since this composite sensor includes a temperature detection part having a thin film thermistor part and a heat flow detection part having a plurality of abnormal Nernstian material films, it is possible to measure temperature and heat flux with the same base material, and at the same time is also composed of layers of films on the same base material, and can be made thinner. In particular, in the heat flow detection unit, a plurality of abnormal Nernstian material films that generate a voltage in a direction perpendicular to the direction of heat flow are arranged in a planar direction and electrically connected in series, so that an abnormal Nernstian detection can be performed with a large number of wires. By arranging the material films, the voltage can be amplified without increasing the thickness.

A composite sensor according to a second invention is the composite sensor according to the first invention, wherein the connection wiring is disposed between the mutually facing abnormal Nernstian material films, and connected to one end side of one of the mutually facing abnormal Nernstian material films. It is characterized in that it is connected to the other end side of the other abnormal Nernstian material film.
That is, in this composite sensor, the connection wiring is disposed between the abnormal Nernstian material films facing each other, and connects one end side of one of the abnormal Nernstian material films facing each other and the other end side of the other abnormal Nernstian material film. Since they are connected, voltages generated in the same direction in each anomalous Nernst material film such as a ferromagnetic material can be added and amplified.

A composite sensor according to a third invention is the composite sensor according to the first or second invention, wherein the thin film thermistor section has a higher electrical resistance than the abnormal Nernst material film, and the abnormal Nernst material film is the thin film thermistor section. characterized by being formed above or below the
That is, in this composite sensor, the thin-film thermistor section has a higher electric resistance than the anomalous Nernst material film, and the anomalous Nernst material film is formed above or below the thin-film thermistor section. It is possible to reduce the size of the device, and the temperature detection unit and the heat flow detection unit are formed in the same portion with a laminated structure, so that the temperature and the heat flux can be detected with higher accuracy. Moreover, even if the heat source is minute and the contact area between the sensor and the heat source is small, both the temperature and the heat flux of the minute heat source can detectable.
Since the thin film thermistor has a resistance higher than that of the abnormal Nernstian material film, the influence of the conductivity of the thin film thermistor can be suppressed in the heat flow detecting section.

A composite sensor according to a fourth invention is the composite sensor according to any one of the first to third inventions, wherein the thin film thermistor section is crystalline Ti-Al-N, and the anomalous Nernst material film is Fe-Al. It is characterized by
That is, in this composite sensor, the thin film thermistor portion is made of crystalline Ti—Al—N, and the anomalous Nernstian material film is made of Fe—Al. high bondability can be obtained. In particular, the thin film thermistor section is represented by the general formula: Ti _x Al _y N _z (0.70≦y/(x+y)≦0.98, 0.4≦z≦0.5, x+y+z=1) In the case of metal nitride thin films, not only a high B constant and high thermal conductivity can be obtained, but also because they have relatively high insulating properties, voltage detection for heat flow detection of stacked anomalous Nernst material films is possible. , not affected by the conductivity of the thin film thermistor. In addition, the thin film thermistor part of this material is a flexible film, and by forming it on a flexible substrate together with the anomalous Nernst material film, a flexible composite sensor can be obtained as a whole. .

A composite sensor according to a fifth invention is characterized in that, in any one of the first to fourth inventions, the substrate is an insulating film.
That is, in this composite sensor, since the base material is an insulating film, it is possible to obtain flexibility as a whole, and when it is pressed against the object to be measured, it bends flexibly and comes into surface contact with the object to be measured. is possible, and flexibility and high temperature responsiveness can be combined while the degree of freedom of installation is improved. In particular, since both the temperature detection part and the heat flow detection part provided on the insulating film are laminated bodies of films, they can have high flexibility. In addition, an insulating resin film, a flexible glass substrate, or the like can be used as the insulating film.

ADVANTAGE OF THE INVENTION According to this invention, there exist the following effects.
That is, according to the composite sensor of the present invention, since it is equipped with the temperature detection part having the thin film thermistor part and the heat flow detection part having a plurality of abnormal Nernstian material films, the temperature and the heat flux can be detected with the same base material. In addition to being measurable, all of them are composed of layers of films on the same base material, so they can be made thinner and can measure heat flow with high accuracy.
Therefore, with the composite sensor according to the present invention, it is possible to obtain a high degree of freedom in design, for example, when it is mounted inside an electronic device. Further, in the composite sensor according to the present invention, the heat flow detection part can be applied not only for the heat flow sensor but also for power generation by heat flow and switch use.

1 is a plan view showing a first embodiment of a compound sensor according to the present invention; FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 2 is a cross-sectional view taken along line BB of FIG. 1; FIG. 2 is a sectional view taken along line CC of FIG. 1; FIG. 4 is a plan view showing a second embodiment of a compound sensor according to the present invention; FIG. 6 is a cross-sectional view taken along the line A'-A' of FIG. 5; 6 is a cross-sectional view taken along line B'-B' of FIG. 5; FIG. FIG. 6 is a cross-sectional view taken along the line C'-C' of FIG. 5;

A first embodiment of a composite sensor according to the present invention will be described below with reference to FIGS. 1 to 4. FIG. In addition, in the drawings used for the following description, the scale is appropriately changed as necessary in order to make each part recognizable or easily recognizable.

The composite sensor 1 of this embodiment includes an insulating base material 2, a thin film thermistor section 3 formed on the base material 2, and a pair of opposed and a plurality of anomalous Nernst materials that are formed on the base material 2, extend in the same direction, and are arranged parallel to each other in the planar direction of the base material 2 to obtain an anomalous Nernst effect. A heat flow detection unit 8 having a film 6 and a connection wiring 7 electrically connecting a plurality of abnormal Nernst material films 6 in series is provided.

The composite sensor 1 of the present embodiment also includes a pair of first pattern wirings 9 formed on the substrate 2 and connected to the pair of counter electrodes 4, and a plurality of abnormal Nernstian wires formed on the substrate 2 and connected in series. and a pair of second pattern wirings 10 connected to both ends of the material film 6 .
The first pattern wiring 9 and the second pattern wiring 10 extend in the same direction to the edge of the strip-shaped base material 2 .
The pair of first pattern wirings 9 has a pair of first pad portions 9a for connecting lead wires at the ends of the substrate 2, and the pair of second pattern wirings 10 has lead wires at the ends of the substrate 2. It has a pair of second pad portions 10a for connection.
Note that areas other than the first pad section 9a and the second pad section 10a may be covered with a protective film.

The connection wires 7 are arranged between the abnormal Nernst material films 6 facing each other, and connect one end side of the abnormal Nernst material film 6 facing each other and the other end side of the other abnormal Nernst material film 6 . ing.
In this embodiment, for example, as shown in FIG. Abnormal Nernst material films 6 are connected in series by connection wires 7 . As a result, the sum of the voltages generated in the four abnormal Nernst material films 6 is generated between the pair of second pattern wirings 10 .

A plurality of abnormal Nernstian material films 6 are formed in strips or lines arranged parallel to each other with respect to the direction of voltage generated with respect to the heat flow in the thickness direction.
By increasing the number and length of the anomalous Nernst material films 6 connected in series, the obtained voltage can be increased.

The thin film thermistor section 3 has a higher electrical resistance than the abnormal Nernst material film 6 , and the abnormal Nernst material film 6 is formed above or below the thin film thermistor section 3 . In this embodiment, the anomalous Nernst material film 6 is formed and laminated on the thin film thermistor section 3, but the anomalous Nernst material film 6 is formed below the thin film thermistor section 3 and laminated conversely. I don't mind.

In this embodiment, the thin film thermistor portion 3 is made of crystalline Ti--Al--N, and the anomalous Nernstian material film 6 is made of Fe--Al.
The thin film thermistor portion 3 has a general formula: M _x A _y N _z (where M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si): 0.70 ≤ y / (x + y) ≤ 0.98, 0.4 ≤ z ≤ 0.5, x + y + z = 1), a hexagonal wurtzite single phase A material consisting of a metal nitride is preferred. In the present embodiment, the thin film thermistor section 3 has a general formula: Ti _x Al _y N _z (where 0.70≦y/(x+y)≦0.98, 0.4≦z≦0.5, x+y+z=1 ) and adopts a metal nitride that is a hexagonal wurtzite type single phase.

The wurtzite crystal structure has a hexagonal space group P6 ₃ mc (No. 186), and M and A belong to the same atomic site (M is Ti, V, Cr, Mn, Fe, Co, At least one of Ni and Cu is shown, and A is Al or (Al and Si)), which is a so-called solid solution state. The wurtzite type has a vertex-connected structure of (M, A) N ₄ tetrahedra, the nearest site of the (M, A) site is N (nitrogen), and (M, A) has nitrogen 4 coordination. Take.

In addition to Ti, V (vanadium), Cr (chromium), Mn (manganese), Fe (iron), Co (cobalt), Ni (nickel), and Cu (copper) are the same as Ti in the above crystal structure. It can exist at an atomic site and can be an element of M. The effective ionic _radius is a physical property value that is often used to grasp the distance between atoms. _y N _z (where M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si)) can be assumed to be obtained. .
Table 1 below shows the effective ion radii for each ion species of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Si (reference paper RD Shannon, Acta Crystallogr., Sect. A, 32, 751 (1976)).

Note that Ti--Al--N is a nitride insulator having a wurtzite crystal structure. Although V, Cr, Mn, Fe, Co, Ni and Cu belong to the same 3d transition metal elements as Ti, wurtzite type M _x A _y N _z (however, M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si).), thermistor characteristics can be obtained.

The anomalous Nernstian material film 6 includes materials such as Fe--Pt and Co--Pt, and Heusler alloy materials such as Co ₂ MnGa, Co ₂ MnAl and Co ₂ MnSi in addition to Fe--Al. A large ferromagnetic material or an antiferromagnetic material such as Mn ₂ Sn can be used.

The substrate 2 is a strip-shaped or rectangular polyimide insulating resin film, and can be made of PET: polyethylene terephthalate, PEN: polyethylene naphthalate, etc. However, for applications requiring flexibility and heat resistance, A polyimide film with excellent heat resistance is desirable.
As the substrate 2, if flexibility is not required, a glass substrate, an insulating ceramics substrate such as alumina, or the like may be employed. A thinner insulating substrate is desirable for the anomalous Nernstian material of the heat flow detector, because a high voltage can be obtained by passing the heat flow in the direction perpendicular to the substrate.

The pair of counter electrodes 4 are opposed to each other and have a comb pattern having a plurality of comb portions.
For the counter electrode 4 and the first pattern wiring 9, various metal films such as a single layer of Cr film and a laminated metal film of a Cr film and an Au film can be used.
The second pattern wiring 10 is preferably an Au film with a small electromotive force, but a laminated metal film or the like of a Cr film and an Au film can also be used.
If the first pattern wiring 9 and the second pattern wiring 10 are made of the same electrode material, the electrode material film forming process and the patterning process can be the same, and the process can be simplified.

The manufacturing method of the composite sensor 1 of the present embodiment comprises first forming the thin film thermistor portion 3 on the substrate 2 and then patterning the thin film thermistor portion forming step; It has an anomalous Nernst material film forming step of forming a film and further patterning, and an electrode forming step of forming a film of the counter electrode 4, the first pattern wiring and the second pattern wiring 10, and further patterning.

In the thin film thermistor portion forming step, the thin film thermistor portion 3 is formed on the substrate 2 by, for example, performing reactive sputtering in a nitrogen-containing atmosphere using a Ti—Al alloy sputtering target.
In the abnormal Nernst material film forming step, the abnormal Nernst material film 6 is formed by sputtering using, for example, an Fe—Al alloy sputtering target.

As described above, the composite sensor 1 of the present embodiment includes the temperature detection section 5 having the thin film thermistor section 3 and the heat flow detection section 8 having a plurality of abnormal Nernst material films 6. The temperature and heat flux can be measured, and both of them are constructed by laminating films on the same base material 2, so that they can be made thinner. In particular, the heat flow detector 8 has a plurality of abnormal Nernstian material films 6 in which a voltage is generated in a direction orthogonal to the direction of heat flow, and is electrically connected in series by arranging them in the planar direction. By arranging the abnormal Nernst material films 6, the voltage can be amplified without increasing the thickness.

In addition, since the thin film thermistor section 3 has a higher electric resistance than the abnormal Nernst material film 6 and the abnormal Nernst material film 6 is formed above or below the thin film thermistor section 3, the size in the plane direction can be reduced. In addition, the temperature detection unit 5 and the heat flow detection unit 8 are formed in the same portion with a laminated structure, so that the temperature and the heat flux can be detected with higher accuracy.
Further, even if the heat source is minute and the contact area between the sensor and the heat source is small, the area of the temperature detection unit 5 can be reduced because the temperature detection unit 5 and the heat flow detection unit 8 have a laminated structure. , both the temperature and the heat flux of a small heat source can be detected.
In the case of point contact with the heat source, the heat flow is immediately transmitted to the thin film thermistor portion 3 by making point contact with the heat flow detecting portion 8, so that the thin film thermistor portion 3 can detect the temperature of the heat source.

In addition, since the thin film thermistor portion 3 is made of crystalline Ti--Al--N and the anomalous Nernst material film 6 is made of Fe--Al, Al among the constituent elements is common to each other. You can get sex. In particular, the thin film thermistor portion 3 is represented by the general formula: Ti _x Al _y N _z (0.70≦y/(x+y)≦0.98, 0.4≦z≦0.5, x+y+z=1). When it is made of a metal nitride, a high B constant and a high thermal conductivity can be obtained, and it also has a relatively high insulating property. Not easily affected by gender.

In addition, the thin film thermistor part 3 of this material is a flexible film, and by forming it on the base material 2 having flexibility together with the abnormal Nernst material film 6, a composite sensor having flexibility as a whole can be obtained. be able to.
That is, if the base material 2 is an insulating film, flexibility as a whole can be obtained, and when it is pressed against the object to be measured, it can be flexibly bent and brought into surface contact with the object to be measured. , the degree of installation freedom is improved, and both flexibility and high temperature responsiveness can be achieved.

Next, a second embodiment of the composite sensor according to the invention will be described below with reference to FIGS. 5 to 8. FIG. In addition, in the following description of the embodiments, the same reference numerals are assigned to the same constituent elements as described in the above embodiments, and the description thereof will be omitted.

The difference between the second embodiment and the first embodiment is that in the first embodiment, the abnormal Nernst material film 6 is laminated on the thin film thermistor section 3 and the heat flow detection section 8 is provided on the temperature detection section 5. On the other hand, in the composite sensor 21 of the second embodiment, as shown in FIGS. and the heat flow detection unit 8 are arranged adjacent to each other.

As described above, in the second embodiment, the abnormal Nernst material film 6 is formed on the base material 2 in the vicinity of the thin film thermistor section 3, so that the temperature detection section 25 and the heat flow detection section are similar to the first embodiment. 28 can be made of a film on the same base material 2, and the thickness can be reduced.

The technical scope of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.
For example, in each of the embodiments described above, an insulating resin film is used as the base material, but a flexible glass substrate may be used. If the base material is a flexible glass substrate, flexibility can be obtained as a whole, as in the above embodiment. The flexible glass substrate is an ultra-thin tempered glass substrate that is resistant to bending and has undergone glass strengthening treatment such as chemical strengthening and surface strengthening (for example, commercially available G-Leaf manufactured by Nippon Electric Glass Co., Ltd.). (registered trademark)), etc. can be adopted, and soda glass substrates manufactured by conventional float manufacturing methods, etc., quartz substrates, Pyrex (registered trademark) substrates (Corning borosilicate glass trademark, (PYREX (registered trademark) ) is a more flexible glass substrate.
In order to give the substrate flexibility, resistance to bending is required. The evaluation method is to sandwich the substrate between two flexible thin resin films, wrap it around a cylindrical object with a diameter of 200 mm (the reason for sandwiching between the two is to bend the substrate uniformly), and then return the substrate to its original flatness. Perform a bending test to return to a normal state. A bend-tolerant substrate is a substrate that does not split or crack after a bending test. Among them, a substrate that does not crack even when the diameter of a cylindrical object is smaller is a substrate with high bending resistance and is suitable as a flexible substrate.

Reference Signs List 1, 21 Composite sensor 2 Substrate 3 Thin film thermistor 4 Opposite electrode 5, 25 Temperature detector 6 Abnormal Nernst material film 7 Connection wiring 8, 28 Heat flow detector

Claims (5)

an insulating substrate;
a temperature detection part having a thin film thermistor part formed on the base material and a pair of counter electrodes formed facing at least one of upper and lower sides of the thin film thermistor part;
a plurality of anomalous Nernstian material films formed on the base material and extending in the same direction and arranged parallel to each other in a planar direction of the base material to obtain an anomalous Nernstian effect; and a heat flow detection unit having a connection wiring electrically connected in series,
The thin film thermistor section has a higher electrical resistance than the anomalous Nernst material film,
A composite sensor , wherein the anomalous Nernst material film is laminated above or below the thin film thermistor section . The composite sensor of claim 1, wherein
The connection wiring is disposed between the abnormal Nernst material films facing each other, and connects one end side of one of the abnormal Nernst material films facing each other and the other end side of the other abnormal Nernst material film. A composite sensor characterized by: The composite sensor according to claim 1 or 2,
The thin film thermistor portion has the general formula: M _x A _y N _z (where M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si): 0.70 ≤ y / (x + y) ≤ 0.98, 0.4 ≤ z ≤ 0.5, x + y + z = 1) and is a hexagonal wurtzite single phase metal A material made of nitride,
A composite sensor , wherein the anomalous Nernstian material film is Fe—Al, Co ₂ MnGa, Co ₂ MnAl, Co ₂ , MnSi or Mn ₂ Sn . In the composite sensor according to any one of claims 1 to 3,
the thin film thermistor portion is crystalline Ti-Al-N,
A composite sensor, wherein the anomalous Nernstian material film is Fe—Al. In the composite sensor according to any one of claims 1 to 4,
A composite sensor, wherein the substrate is an insulating film.

Images