KR101670773B1 - Seebeck measurement system for thermoelectric thin film - Google Patents

Abstract

The apparatus for measuring the whitening coefficient of a thermoelectric thin film according to the present embodiment includes: a chamber configured to maintain a vacuum degree in an inner space; A turbo pump installed in the chamber for discharging air in the internal space part and adjusting a degree of vacuum in the chamber internal space part; A jig module installed in the inner space and supporting and fixing a side wall of a plurality of structures; A heater unit fixed by the jig module and disposed on a bottom surface of the inner space; A cooling unit disposed above the heater unit for discharging the heat of the heater unit to the outside; At least a pair of insulating units interposed between the heater unit and the cooling unit; And a pair of sensing units interposed between the pair of insulating units, wherein a sample to be measured is interposed between the pair of sensing units.

Description

{Seebeck measurement system for thermoelectric thin film}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus, and more particularly, to an apparatus for measuring a whitening coefficient of a thermoelectric thin film.

In the thermoelectric material, a potential difference is generated according to the temperature gradient. The effect of generating the potential difference according to the temperature gradient is called a seebeck effect. The use of such a whitening effect enables energy generation. On the other hand, the Peltier effect can be applied to the opposite direction of the Seebeck effect due to the effect of temperature gradient due to the potential difference.

The thermoelectric properties used as a parameter of the thermoelectric performance index used as a measure of power generation efficiency using the thermoelectric material include electrical conductivity and thermal conductivity in addition to the above-mentioned whiteness coefficient. The whiteness factor can be used as a key indicator of the thermoelectric performance index as a measure of how much the whitening effect is on the thermoelectric material.

Conventionally, in order to measure the above-mentioned whiteness coefficient, a whitening coefficient is measured on a sample having a bulk shape of 100 μm or more. In the case of a thin film sample, only an in-plane direction measurement is possible.

Korean Registered Patent No. 10-1408681 (Registered on June 11, 2014)

SUMMARY OF THE INVENTION The present invention provides a device for measuring the whitening coefficient of a thermoelectric thin film, which is designed to measure a whitening coefficient in a cross-plane direction passing through a thin film sample.

The technical object of the present invention is not limited to the above-mentioned technical objects and other technical objects which are not mentioned can be clearly understood by those skilled in the art from the following description will be.

The apparatus for measuring the whitening coefficient of a thermoelectric thin film according to the present embodiment includes: a chamber configured to maintain a vacuum degree in an inner space; A turbo pump installed in the chamber for discharging air in the internal space part and adjusting a degree of vacuum in the chamber internal space part; A jig module installed in the inner space and supporting and fixing a side wall of a plurality of structures; A heater unit fixed by the jig module and disposed on a bottom surface of the inner space; A cooling unit disposed above the heater unit for discharging the heat of the heater unit to the outside; At least a pair of insulating units interposed between the heater unit and the cooling unit; And a pair of sensing units interposed between the pair of insulating units, wherein a sample to be measured is interposed between the pair of sensing units.

The jig module includes: a pair of jigs supporting both side walls of the heater unit and the cooling unit; And a fixing unit for fixing the position of the jig.

The heater unit includes: a heater fixedly disposed on a bottom surface of the chamber; And a first heat storage portion, wherein the bottom surface is in contact with the heater, and the upper surface is disposed in surface contact with the insulating unit.

The first heat storage portion may be formed of copper or aluminum.

The cooling unit includes a second heat storage portion having a bottom surface in surface contact with the insulation unit; And a heat sink which is in surface contact with the upper surface of the second heat storage part and discharges heat transferred through the second heat storage part to the space inside the chamber.

A first cooling module disposed at a position close to an inner space of the chamber and having a cooling water flow path therein; A second cooling module disposed at a position close to a heat source transmitted from the second heat storage part and having a cooling water flow path therein; A connection part communicating the cooling water flow paths of the first and second cooling modules; An inlet through which cooling water flows into the first cooling module; And an outlet for discharging the heat-exchanged cooling water of the second cooling module.

The first and second cooling modules may have zigzag cooling water flow paths.

The inlet and the outlet may be formed on the same side wall.

The sensing unit may further include a reference line for guiding an arrangement position of the sample.

The sensing unit may be formed of a platinum (Pt) material with a sensing pattern to which the MEMS technology is applied.

According to the present embodiment as described above, it is possible to directly measure the thermoelectric characteristic of a cross-plane thermoelectric thin film, which has not been attempted in the past, not in the various in- It is possible.

1 is a schematic view of a whitening coefficient measuring apparatus according to a first embodiment,
2 is a schematic view of a whitening coefficient measuring apparatus according to a second embodiment,
3 is a schematic drawing of a whitening coefficient measuring apparatus according to a third embodiment,
4 is a schematic structural view of a heat sink of the whitening coefficient measuring apparatus according to the present embodiment,
Fig. 5 is a front view of the heat sink of Fig. 4,
Figure 6 is a cross-sectional view of the first cooling module of the heat sink of Figure 5,
Figure 7 is a cross-sectional view of the second cooling module of the heat sink of Figure 5,
FIG. 8 is a cross-sectional view of the connection portions of the first and second cooling modules of the heat sink of FIG. 5,
Fig. 9 is a vertical cross-sectional view of the heat sink of Fig. 5,
FIG. 10 schematically shows two overlapping sensing units according to the present embodiment, FIG.
11 is a view showing a state in which a sample is placed between the overlapping sensing units of FIG. 10, and FIG.
12 is a schematic structural view of a sample used in this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The sizes and shapes of the components shown in the drawings may be exaggerated for clarity and convenience. In addition, terms defined in consideration of the configuration and operation of the present invention may be changed according to the intention or custom of the user, the operator. The definitions of these terms should be interpreted based on the contents of the present specification and meanings and concepts in accordance with the technical idea of the present invention.

2 is a schematic view of a whitish-coefficient-measuring apparatus according to a second embodiment, and Fig. 3 is a cross-sectional view of a whitish-coefficient-measuring apparatus according to a third embodiment of the present invention. Fig. 5 is a front view of the heat sink of Fig. 4, Fig. 6 is a front view of the first cooling module of the heat sink of Fig. 5, Fig. Fig. 7 is a cross-sectional view of the second cooling module of the heat sink of Fig. 5, Fig. 8 is a sectional view of the connection portion of the first and second cooling modules of the heat sink of Fig. 10 is a view schematically showing a sensing unit according to the present embodiment, FIG. 11 is a view showing a state in which a sample is placed between sensing units overlapped with each other in FIG. 10, and FIG. 12 is a view And is a schematic structural view of a sample used in the example.

1, the apparatus for measuring the whitening coefficient of a thermoelectric thin film according to the present embodiment includes a chamber 100, a turbo pump 110, a jig module 200, a heater unit 300, a cooling unit 400, A unit 500 and a sensing unit 1000. [

The chamber 100 may have a structure having an internal space, and may be formed in an airtight structure so that the internal space can be completely shielded from the outside. With this configuration, the degree of vacuum of the internal space portion can be secured to 10 ^-5 Torr or less. The turbo pump 110 may be installed in the chamber 100 to suck and discharge air to maintain the degree of vacuum of the internal space of the chamber 100. When the chamber 100 is maintained in a vacuum state, a precise temperature control and measurement environment due to the removal of the convection effect can be created. In other words, the natural convection effect is caused by the buoyancy, which is the resultant of the volume force, in the atmospheric system with the density gradient. In general, the natural convection effect is drastically reduced at a pressure of 10 ^-3 to 10 ² Torr. In addition, because of pressure conditions of 10 ^-6 Torr or lower it is difficult to develop equipment to a surge in the measuring equipment produced during degassing (outgassing) element, the degree of vacuum in the chamber 100 according to this embodiment is 10 ^-4 to 10 ^{- 6} Torr pressure condition area.

The jig module 200 is for fixing the structures installed in the internal space part and may include the jig 210 and the fixing unit 220 according to the present embodiment. The jig 210 supports the side walls of the heater unit 300 and the cooling unit 400, which will be described later, and can press and hold the jig 210 so as to prevent up, down, left, and right swinging. The fixing unit 220 fixes the position of the jig 210 so that the components can be locked so as not to be detached from the fixing position.

The heater unit 300 may include a heater 310 using a precision stage heater for heating and a first heat storage part 320.

The heater 310 may use a radiation shield heater to reduce variations in the temperature of the sample S. According to the first embodiment, the heater 310 can be fixed to the bottom surface of the chamber 100, and heat can be applied to the sample S by radiating heat to the upper surface side. In addition, the heater can provide heat to the system by using a stage heater with an output of about 1 to 100 W. By using a radiation shielding heater as described above, a high output can be satisfied while heating a wide area, And the external environment temperature can be adjusted to about 10 degrees Celsius, thereby eliminating the radiation effect.

Meanwhile, according to the second embodiment, the heater 310 may be disposed at a distance D2 from the bottom surface of the chamber 100, as shown in FIG. The distance D2 of the heater 310 may correspond to the distance D1 between the heat sink 420 and the chamber 100 constituting the cooling unit 400. [

In addition, according to the third embodiment, as shown in FIG. 3, a radiation shielding heater 2100 having a radiation shielding frame 2000 may be further provided, in addition to the heater 310. In this case, the heater unit 300, the cooling unit 400, the insulating unit 500, and the like, which constitute the above-described whitening coefficient measuring apparatus, may be disposed in the inner space of the radiation shielding frame 2000.

With such a configuration, it is possible to suppress the radiation phenomenon, which is one of the temperature fluctuation factors of the system and the provision of the heat quantity of the entire system under the vacuum condition. That is, as the high output is applied to the stage heater 310, the time required for heating the entire system can be shortened, and the time required for heating can be set to be in the range of 500 to 5000 s in inverse proportion to the output.

The bottom surface of the first heat storage part 320 may be placed on the upper surface of the heater 310 and the upper surface of the first heat storage part 320 may be in surface contact with the insulating unit 500 to be described later. According to the present embodiment, the first heat storage part 320 may be formed of copper and aluminum, which are thermally conductive metals. In addition, the side walls of the first row storage part 320 and the heater 310 may be fixed and supported by the jig 210 described above. The bottom surface of the first heat storage part 320 is wider than the top surface so that the contact area of the heater 310 contacts the first insulating substrate 510, Can be configured to be wider than the area.

The cooling unit 400 may be disposed on the upper side of the heater unit 300 and may discharge the heat generated in the heater unit 300 toward the inner space side of the chamber 100 in the system. According to the present embodiment, the cooling unit 400 may be composed of the second heat storage part 410 and the heat sink 420.

The second column storage unit 410 may be configured in the same manner as the first column storage unit 320 described above. For example, the upper surface may be formed to be wider than the contact area with the second insulating substrate 520, which constitutes the insulating unit 500, which will be described later, with respect to the heat sink 420 The contact area can be made larger.

The heat sink 420 may include a first cooling module 421, a second cooling module 422, a connection 423, an inlet 424 and an outlet 425, as shown in FIGS. 4-9. have.

The first cooling module 421 may be formed in a substantially cylindrical shape as shown in the figure, and a cooling water channel may be formed in a zigzag form in the first cooling module 421. The first cooling module 421 may be formed of a material having excellent thermal conductivity and may be formed of a single body.

The second cooling module 422 may have the same configuration as the first cooling module 421 described above. That is, the second cooling module 422 may have a cooling water channel formed therein in a zigzag fashion. In addition, the second cooling module 422 may be formed of a material having excellent thermal conductivity, and may be formed of a single body.

The first and second cooling modules 421 and 422 may be configured to have a cylindrical shape through vertical coupling. The bottom surface of each of the first and second cooling modules 421 and 422 may have a connection portion 423, The cooling water flow path formed in a zigzag manner can be communicated with each other.

One side of the first cooling module 421 is formed with an inlet port 424 through which the cooling water flows and the other side of the second cooling module 422 is formed with the same surface as the surface on which the inlet port 424 is formed An outlet 425 may be formed. If the inlet 424 and the outlet 425 are formed on the same side wall as described above, the travel distance of the cooling water becomes longer, so that the heat exchange can proceed more effectively.

On the other hand, the cooling water may use any one of a liquid and a gas which can be used as a refrigerant, but the present invention is not limited thereto. According to this embodiment, distilled water can be utilized as cooling water. This is because distilled water has a large specific heat, it is easy to construct a cooling water temperature control system, and it is easy to control the discharge of heat. Alternatively, it is possible to use a gas such as nitrogen, helium air or the like instead of the cooling water.

As described above, the first and second cooling modules 421 and 422 may be formed of a metal material having excellent thermal conductivity. For example, the first and second cooling modules 421 and 422 may be made of copper or aluminum, It is possible to effectively transmit the amount of heat generated in the cooling water.

The first and second cooling modules 421 and 422 are preferably symmetrical two-tiered structures, and the temperature gradient in the planar direction of the discharge plate in which low-temperature cooling water is generated due to heating can be minimized .

The insulating unit 500 is interposed between the heater unit 300 and the cooling unit 400 and may include a pair of first and second insulating substrates 510 and 520. The first and second insulating substrates 510 and 520 may be formed of a ceramic material as a ceramic substrate and can simultaneously perform electrical connection and heat dissipation. The first and second insulating substrates 510 and 520 may be formed of a ceramic material that is partially covered with a thin metal film made of gold or copper having good electrical conductivity. The ceramic material may include alumina (Al ₂ O ₃ ) Aluminum (AlN). At this time, the metal film portion is used as a terminal for connecting to an external measuring instrument.

The sensing unit 100 is interposed between the pair of first and second insulating substrates 510 and 520, and a pair of the sensing units 100 may be arranged symmetrically. That is, the sensing unit 100 may be arranged in a sandwich shape with the sample S sandwiched therebetween as shown in FIG. 1, and may be provided with a precision platinum sensor manufactured using MEMS technology. The sensing unit 1000 may be provided with a platinum 100? RTD sensor for measuring the thin film surface temperature. 10, the sensing unit 1000 is provided with a plurality of reference lines 1100 arranged in a diagonal direction with respect to the terminal portions, and the sample S is placed on the reference line 1100 as shown in FIG. 11, The averaged temperature of the region can be obtained.

On the other hand, as shown in FIG. 12, the sample S can be formed by using a deposition method. That is, PLD, CVD, ALD, and sputtering, which are widely used in the laboratory and the real industry, can be used as a thin film thermoelectric material synthesis method. Since the whitening coefficient measuring apparatus according to the present embodiment is used for measurement of a deposited thin film of 1 to 100 μm thickness which can not be measured by commercial measurement equipment, the nanostructured bulk material Can be used as a sample (S). Such a sample S is a structure capable of securing a low thermal conductivity and a high electric conductivity in order to improve the thermoelectric performance. The thermoelectric material S is disposed on the uppermost side, and a target material base It has a silicon oxide (SiO ₂₎ (S1) and silicon (Si) (S2) can be placed. With this configuration, the sample S can be synthesized by using a specific material such as a Be-Te-based material in a region of less than 200 ° C corresponding to a low-temperature region for thermoelectric material power generation.

According to the present embodiment as described above, since the whitening coefficient can be measured in a cross-plane passing through the sample, it is possible to measure different thermoelectric properties in the horizontal direction and the vertical direction due to the unique crystal structure of the thermoelectric material It is possible to do.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the true scope of the present invention should be determined by the following claims.

100; Chamber 110; Turbo pump
200; A jig module 210; Jig
220; Fixed unit 300; Heater unit
310; Heater 320; The first-
400; A cooling unit 410; The second-
420; A heat sink 421; The first cooling module
422; A second cooling module 423; Connection
424; Inlet 425; outlet
500; Insulating unit 510; The first insulating storage portion
520; A second insulating storage unit 1000; Sensing unit
1100; Baseline 2000; Radiation shield frame
2100; Radiation shield heater S; Sample

Claims (10)

A chamber configured to maintain a vacuum degree in an inner space portion;
A turbo pump installed in the chamber for discharging air in the internal space part and adjusting a degree of vacuum in the chamber internal space part;
A jig module installed in the inner space and supporting and fixing a side wall of a plurality of structures;
A heater unit fixed by the jig module and disposed on a bottom surface of the inner space;
A cooling unit disposed above the heater unit for discharging the heat of the heater unit to the outside;
At least a pair of insulating units interposed between the heater unit and the cooling unit; And
And a pair of sensing units interposed between the pair of insulating units,
A sample to be measured is formed in a thin film form on a target material base formed by forming silicon oxide on a silicon surface and interposed between the pair of sensing units with the sample formed on the target material base,
The jig module includes:
A pair of jigs supporting the heater unit and both side walls of the cooling unit so as to prevent the heater unit and the cooling unit from swinging up and down and left and right; And
And a fixing unit for fixing the position of the jig,
The heater unit includes:
A heater fixedly disposed on the bottom surface of the chamber; And
And a first heat storage portion arranged to face the bottom surface of the heater and the upper surface to be in surface contact with the insulating unit,
The cooling unit includes:
A bottom surface of which is in surface contact with the insulating unit; And
And a heat sink which is in surface contact with the upper surface of the second heat storage part and discharges heat transferred through the second heat storage part to the external space of the chamber,
The heat sink
A first cooling module disposed at a position close to an inner space of the chamber and having a cooling water flow path therein;
A second cooling module disposed at a position close to a heat source transmitted from the second heat storage part and having a cooling water flow path therein;
A connection part communicating the cooling water flow paths of the first and second cooling modules;
An inlet through which cooling water flows into the first cooling module; And
And an outlet for discharging the heat-exchanged cooling water of the second cooling module.
delete delete The plasma display apparatus according to claim 1,
An apparatus for measuring the whiteness coefficient of a thermoelectric thin film formed of copper or aluminum, which is a highly conductive metal.
delete delete The method according to claim 1,
Wherein the first and second cooling modules each have a zigzag cooling water flow path.
The method according to claim 1,
Wherein the inlet port and the outlet port are formed on the same side wall.
The apparatus of claim 1, wherein the sensing unit comprises:
And a reference line for guiding an arrangement position of the sample.
The apparatus of claim 1, wherein the sensing unit comprises:
An apparatus for measuring the whiteness coefficient of a thermoelectric thin film in which a sensing pattern using MEMS technology is formed of platinum (Pt) material.

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