JP2009105132A - Thermoelectric characteristic measuring sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in the conventional method using Harman process etc. and further to provide a compact and easily handleable thermoelectric characteristic measuring sensor. <P>SOLUTION: The thermoelectric characteristic measuring sensor is characterized by comprising: a film-shaped base; at least four openings drilled and linearly provided in the base at predetermined spacings; contact portions consisting of electrodes provided to be in contact with the sample in the openings; and wiring for electrically connecting respective contact portions to a plurality of leads connected to an external apparatus, and at least one of the contact portions is formed of a thermocouple. Seebeck coefficient, thermal conductivity and specific resistance can be measured easily and with high precision by such a configuration. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sensor for measuring a thermoelectric property that can be used for measuring a thermoelectric property required for development of a thermoelectric material.

  The performance evaluation of the thermoelectric material is expressed by its performance index Z, and is derived from the product of Seebeck coefficient, specific resistance, and thermal conductivity. The development of thermoelectric materials often requires measurement of these three physical properties. As methods for measuring these three physical property values, the Herman method and the optical alternating current method are conventionally known.

However, the Herman method has a drawback that the accuracy of thermal conductivity measurement is not good. In addition, the optical alternating current method has a drawback that the apparatus must be large because there is an operating part. Furthermore, in these methods, silver paste is generally used to attach the sample to the sensor. For this reason, (b) it takes time to manufacture the measurement sample. Uncertainty in electromotive force measurement (c) There is a problem in that there is uncertainty in thermal diffusivity measurement due to the temperature response delay of silver paste.

  Accordingly, an object of the present invention is to provide a thermoelectric characteristic measuring sensor that can solve the above-described problems and is compact and easy to handle.

  A first invention that achieves the above object is a thermoelectric property measurement sensor for measuring a plurality of thermoelectric properties of a sample, and is linearly formed at predetermined intervals inside a film-like substrate and the substrate. At least four electrodes arranged, wiring provided inside the base material to electrically connect the electrodes to leads, and electrode positions on one side of the front and back sides of the base material, A sensor for measuring a thermoelectric characteristic, comprising: an opening provided to expose the sample, wherein at least one of the contact parts is constituted by a thermocouple having a plurality of wirings.

  The thermoelectric characteristic measuring sensor may further include a heater for heating the sample and a wiring for electrically connecting the heater to the lead on the base material. The base material includes, for example, a first layer and a second layer, and the electrodes and the wirings are formed between the first layer and the second layer. Each said electrode and each wiring can be formed by vapor deposition in the 1st apparatus of the said base material, for example. As a material of the base material, for example, polyimide can be used. The thermoelectric characteristics that can be measured by the thermoelectric characteristic measuring sensor of the present invention include Seebeck coefficient, thermal conductivity, and specific resistance.

  A second invention that achieves the above object is a sample holder for holding a sample together with the thermoelectric characteristic measurement sensor according to the first invention, provided at a position corresponding to each of the electrodes, and the corresponding electrode and sample. A sample holder characterized by having a holding means for holding the sample.

  A third invention that achieves the above object is a method of creating a sensor for measuring thermoelectric characteristics for measuring a plurality of thermoelectric characteristics of a sample, and is arranged linearly at predetermined intervals on a first layer of a substrate. Forming at least four electrodes and wiring corresponding to each electrode by vapor deposition, forming a hole in the second layer of the substrate at a position corresponding to each electrode, and first layer The method includes a step of aligning the corresponding electrode and the opening on the side on which the electrode and the wiring are formed, and bonding the second layer of the base material.

  As described above, the sensor for measuring thermoelectric characteristics is provided with an electrode and a wiring inside a single film-like base material, and an opening is provided so that each electrode position is exposed on one side of the base material. By adopting the configuration, it is possible to provide a thermoelectric property measuring sensor that is compact, lightweight, and has high measurement accuracy. Further, by providing the heater integrally, the entire sensor becomes more compact.

  Furthermore, if measurement is performed using such a sensor for measuring thermoelectric characteristics, not only the labor and time of the entire measurement can be reduced, but all these measurements can be performed in the same environment. Further, when used in combination with the above-described sample holder, the silver paste is not necessary, and thus the above-mentioned drawbacks that are problematic when using the silver paste can be solved.

  FIG. 1 is a plan view of a tip portion of a thermoelectric characteristic measurement sensor (hereinafter referred to as “sensor”) 1. This sensor 1 basically has various electrodes and wirings formed inside a flexible film-like base material 10, and the left side of FIG. A lead for electrically connecting each wiring to an external device is formed on the right side of 1. A wire made of the same material as the lead is formed between the electrode provided on the tip side of the sensor 1 and the corresponding lead.

  In the present embodiment, the width of the tip portion of the sensor 1 is set to 26.5 mm in consideration of compactness and ease of handling. However, the dimensions of each part can be freely designed according to the properties of the measurement object. As the base material 10, for example, a resin film made of polyimide can be used.

  In the sensor 1 shown in FIG. 1, the wirings 12a and 12b are both made of copper, and these are connected to a heater 30 as a heating source provided on the tip side. The wirings 14a and 14b are both made of copper, and these are connected by the contact portion 22 and become electrodes that contact the sample. The wiring 16a is made of alumel, and the wiring 16b is made of chromel, which are connected by a contact portion 24 to become an electrode. The wiring 18a is made of alumel, and the wiring 18b is made of chromel, which are connected by a contact portion 26 to become an electrode. The wirings 20a and 20b are both made of copper, and these are connected by a contact portion 28 to serve as electrodes. Among the electrodes, the electrodes of the contact portions 24 and 26 are connected to different metals such as alumel and chromel to form a thermocouple. The sensor 1 includes a heater 30 and wiring connected thereto, four pairs of electrodes, and wiring corresponding to them.

  As an example, the sensor 1 can be created as follows. First, an electrode, a heater, and a wiring are formed on a polyimide as a base material by vapor deposition. On the other hand, an opening is formed at a position corresponding to each electrode of another polyimide. Then, the two electrodes are bonded together so that the corresponding electrodes and the positions of the openings are aligned, and the electrodes and the wirings are inside. As a result, as shown in the enlarged view of one of the contact portions 24 in FIG. 2, the electrode is exposed only at the contact portion on one side of the base material. In this contact portion, the electrode and the sample can be brought into contact with each other. Thus, the sensor 1 in which only the contact portion on one side of the substrate is opened can be easily created by making the substrate have a two-layer structure.

  As shown in FIG. 1, the electrodes are arranged in a straight line and designed to have a predetermined interval. The distance between the electrodes is an important parameter in calculating various thermoelectric characteristics of the sample. The heater 30 is also provided on the same straight line as each contact portion. In the example of the present embodiment, the heater 30 and the wirings 12a and 12b connected to the sensor 1 are provided in the sensor 1. However, the heater 30 may be separated from the sensor 1, and in this case, the wiring 12a, There is no need to provide 12b.

FIG. 3 shows a state in which the sensor 1 shown in FIG. 1 is attached to the sample holder 50 together with the sample 52. The sample holder 50 is provided with spring contact probes 54 _{1 to} 54 _{4 at} positions corresponding to the contact portions 22, 24, 26, 28 of the sensor 1. Further, acrylic screw 56 _{1-56 4} is provided below each spring contact probe. Corresponding spring contact probes and acrylic screws hold each contact part of the sensor 1 and the sample 50 from above and below. Thereby, an appropriate pressure is applied to each contact portion and the sample, and reliable contact between the contact portion and the sample is obtained.

  By using the sample holder 50 as shown in FIG. 3, each contact part of the sensor 1 and the sample 52 can be reliably brought into contact with each other. Therefore, it has been conventionally required for the connection part between the contact part and the sample. No silver paste is required. As a result, the above problems (A), (B), and (C) due to the use of the silver paste are solved. Moreover, as shown in FIG. 3, since the entire sample holder 50 to which the sensor 1 and the sample 50 are attached can be inserted into a thermostatic chamber or a vacuum vessel, the entire sample can be easily placed in the same environment.

  Although the example using the heater 30 as the heating source has been described above, a resistance heat source such as a Peltier element can also be used as the heating source.

  Next, with reference to FIG. 4 thru | or FIG. 7, the structure of the apparatus in the case of measuring a thermoelectric characteristic using the sensor 1 of this embodiment is demonstrated. 4 to 7 are intended to explain the electrical connection between each lead of the sensor 1 and each device, and are shown in a different manner from the actual sensor 1 shown in FIG. .

  FIG. 4 shows the overall configuration of the apparatus. The sensor 1 is attached to the sample holder 50 shown in FIG. 3 together with the sample 52, placed in the measurement chamber 80, and the measurement chamber 80 is placed in a measurement vessel 82 such as a thermostatic bath or a vacuum vessel. This apparatus includes a lock-in amplifier 60, a temperature measuring multimeter 62, a nanovoltmeter 64, a multimeter 66, a switch box 68, a function generator 70, a DC power source 72, a switch box 74, and a personal computer 76. . The measurement is automatically executed a plurality of times, and the measurement data is taken into the personal computer 76.

  FIG. 5 shows the configuration of a measuring device for obtaining the Seebeck coefficient. Among the devices shown in FIG. 4, a temperature measuring multimeter 62, a nanovoltmeter 64, and a DC power source 72 are mainly used. In order to obtain the Seebeck coefficient, the sample 52 is heated with a heater in a steady state, a quasi-stationary state, and a non-steady state, and the temperature difference between the contact portions of the two thermocouples 16 (16a, 16b) and 18 (18a, 18b) And measure the thermoelectromotive force. Then, the Seebeck coefficient is obtained by calculation based on the obtained measurement data.

  FIG. 6 shows a configuration of a measuring device for obtaining a specific resistance. Among the devices shown in FIG. 4, a temperature measuring multimeter 62, a nanovoltmeter 64, a multimeter 66, and a DC power source 72 are mainly used. Is done. In order to obtain the specific resistance, the outer two pairs of electrodes 12 (12a, 12b) and 20 (20a, 20b) among the four pairs of electrodes are energized to pass a current through the sample 52, and the inner two pairs of electrodes The voltage is measured at 16 and 18. Then, the specific resistance is calculated based on the obtained measurement data.

  FIG. 7 shows the configuration of a measuring device for obtaining the thermal conductivity. Among the devices shown in FIG. 4, a lock-in amplifier 60 and a function generator 70 are mainly used. In order to obtain the thermal conductivity, the sample 52 is periodically heated by the heater 30, and the thermal diffusivity is determined using the difference in temperature response between the heater 30 and the two thermocouples or the frequency dependence of this difference. To do. Specific heat is obtained from temperature amplitude, amount of heat supplied, and frequency. Then, the thermal conductivity is calculated from the product of the obtained thermal diffusivity, specific heat, and density. Further, as a variation of the measurement apparatus of FIG. 7, an AC power source can be provided between the function generator 70 and the switch box 68. Further, a lock-in amplifier with a built-in power supply can be used instead of the function generator 70.

It is a top view of the front-end | tip part of the sensor for thermoelectric characteristic measurement which concerns on one Embodiment of this invention. It is the figure which expanded one contact part of the sensor for thermoelectric characteristic measurement of this embodiment. It is the figure which showed the state which attached the sensor for a thermoelectric characteristic shown in FIG. 1 to the sample holder with the sample. It is the figure which showed the structure of the whole apparatus in the case of measuring a thermoelectric characteristic using the sensor for thermoelectric characteristic measurement of this embodiment. It is the figure which showed the structure of the measuring apparatus for calculating | requiring a Seebeck coefficient among the apparatuses shown in FIG. It is the figure which showed the structure of the measuring apparatus for calculating | requiring specific resistance among the apparatuses shown in FIG. It is the figure which showed the structure of the measuring apparatus for calculating | requiring thermal conductivity among the apparatuses shown in FIG.

Explanation of symbols

1 Sensor for thermoelectric property measurement ("sensor")
10 Substrate 12, 14, 16, 18, 20 Wiring (lead)
22, 24, 26, 28 Contact portion 30 Heater 40 Opening portion 50 Sample holder 52 Sample 54 _{1 to} 54 ₄ Spring contact probe 56 _{1 to} 5 ₄ Acrylic screw 60 Lock-in amplifier 62 Temperature measuring multimeter 64 Nanovoltmeter 66 Multi Meter 68, 74 Switch box 76 Personal computer

Claims (9)

A thermoelectric property measuring sensor for measuring a plurality of thermoelectric properties of a sample,
A film-like substrate;
At least four electrodes arranged linearly at predetermined intervals inside the substrate;
Wiring provided inside the base material and electrically connecting each electrode to a lead;
Each electrode position on one side of the front and back of the base material includes an opening provided to expose the sample to the electrode,
At least one of the electrodes is constituted by a thermocouple having a plurality of wirings.   The sensor for measuring thermoelectric characteristics according to claim 1, wherein a heater for heating the sample and a wiring for electrically connecting the heater to the lead are provided on the base material.   The thermoelectric property according to claim 1 or 2, wherein the base material includes a first layer and a second layer, and each of the electrodes and each wiring is formed between the first layer and the second layer. Sensor for measurement.   The said each electrode and each wiring are the sensors for a thermoelectric characteristic measurement as described in any one of Claims 1 thru | or 3 formed by vapor deposition in the 1st apparatus of the said base material.   The thermoelectric property measuring sensor according to any one of claims 1 to 4, wherein the base material is polyimide.   The thermoelectric characteristic measuring sensor according to any one of claims 1 to 5, wherein the thermoelectric characteristic includes a Seebeck coefficient, a thermal conductivity, and a specific resistance. A sample holder for holding a sample together with the thermoelectric property measuring sensor according to any one of claims 1 to 6,
A sample holder provided with a holding means that is provided at a position corresponding to each of the electrodes and holds the corresponding electrode and the sample in between. A method of creating a thermoelectric property measurement sensor for measuring a plurality of thermoelectric properties of a sample,
Forming at least four electrodes arranged linearly at predetermined intervals on the first layer of the substrate and wiring corresponding to each electrode by vapor deposition;
In the second layer of the base material, a step of opening an opening at a position corresponding to each of the electrodes;
A step of aligning the corresponding electrode and the opening on the side where the electrode and wiring of the first layer are formed, and bonding the second layer of the base material;
A method comprising the steps of:   The method according to claim 8, wherein the material of the base material is polyimide.