KR100440268B1 - The method for manufacturing of thermocouple material - Google Patents

Abstract

The present invention utilizes a Bi ₂ Te ₃ -Sb ₂ Te ₃ based alloy melting and growth apparatus and a hydrogen reduction reactor, hot compression apparatus, coating and processing apparatus. The Bi ₂ Te ₃ -Sb ₂ Te ₃ alloy is melted in a melting apparatus and then reduced in a hydrogen reduction reactor, cooled and powdered by a grinder, and then the powdered Bi ₂ Te ₃ -Sb ₂ Te ₃ alloy is again After growth by charging into the melting apparatus, or maintaining one-way using a hot compression apparatus, and then the ordinary Mo plating and Ni plating to form a Mo and Ni layer on the surface, and then a polymer adhesive layer on the top After forming and then attaching with a coin electrode, and then forming a polymer adhesive layer on top of it, it is a method of manufacturing a thermoelectric material prepared by adhering to the surface consisting of nickel plating layer, ceramic coating layer, SUBSTRATE, aluminum alloy in this order.

Description

The method for manufacturing of thermocouple material

The present invention relates to an apparatus for manufacturing a chemically homogeneous Bi ₂ Te ₃ -Sb ₂ Te ₃ based thermoelectric material, and a manufacturing method using the same, which will be described in detail. And a method of manufacturing a thermoelectric material which can greatly increase the unidirectionality and greatly improve the productivity of the thermoelectric material by greatly improving the mechanical properties of the thermoelectric material and increasing the recovery rate at the time of cutting.

The thermoelectric material used in the present invention is used for local cooling of precision electronic components, and is used in a thermo generator, a sensor protection device of an infrared tracker, an optical communication laser cooling device, a cooling device of a cold / hot water device, a semiconductor temperature saving device, a heat exchanger, a CPU of a semiconductor, and the like. It is mainly used to release heat generated inside the device to the outside.

After the discovery of Seebeck effect, Peltier effect and Thomson effect, the thermoelectric phenomena in the early 19th century, thermoelectric materials with high thermoelectric performance index with the development of semiconductor in the late 1930s Recently, it has been used for special power supply devices such as mountain wallpaper, space, military, etc. using thermoelectric power generation, semiconductor laser diodes using thermoelectric cooling, precise temperature control in infrared detection devices, etc. have.

Since the effect of thermoelectric materials increases with increasing chemical homogenization of thermoelectric materials, it is important to obtain a chemically homogeneous solid solution.

Conventional manufacturing methods include single crystal growth method by band melting method, powder sintering method by grinding, long time thens method, etc., but it is difficult to obtain homogeneous alloys. Particularly, single crystal growth method solidifies into a heterogeneous solid solution due to the presence of Te segregation. The difference in thermoelectric properties is shown due to the difference between the starting point and the end point of solidification.The thermoelectric material obtained by the single crystal growth method has excellent performance, but the unit point is a tetrahedron, so that the base is wall-changed. The recovery rate is reduced, the mechanical strength is very weak, and the powder sintering method by grinding is difficult to manufacture chemically homogeneous thermoelectric material with uniform solid solution due to segregation of Te during ingot grinding. Incorporation of impurities in the process may cause a change in carrier concentration. There are many problems with prolonged time has been a lot of research is still developing as follows:

Korean Patent Publication No. 10-228463 discloses a ribbon-shaped Bi ₂ Te ₃ -based thermoelectric conversion material that melts Bi ₂ Te ₃ -based alloys and rapidly solidifies the molten alloy using a melt spinning method. Pressure forming the thermoelectric conversion material by cold pressing; A method for producing a Bi ₂ Te ₃ -based thermoelectric conversion material sintered body which is produced by pressure sintering a press-formed thermoelectric conversion material by hot pressing is described.

The publication Registration No. 10-228464 discloses a Bi ₂ Te ₃ -Sb ₂ Te ₃ by rapid solidification cooling by spraying a molten alloy by melting the alloy in the high-pressure gas of nitrogen fluoride Castle, fine, the shape close to the spherical Bi ₂ A method for preparing Te ₃ -Sb ₂ Te ₃ thermoelectric powder is disclosed.

Publication No. 181366 describes a method for producing Bi-Te-based thermoelectric materials with excellent thermoelectric properties by increasing the density of Bi-Te-based thermoelectric materials, minimizing the grain size and anisotropy by using a hot extrusion process. ,

Korean Patent Publication No. 99-67520 discloses thermoelectric elements of P-type and N-type thermoelectric semiconductors which are convenient for intermediate connection with electrodes in order to provide modules or circuits of thermoelectric heaters / coolers or thermoelectric generators. [0003] In Japanese Patent Laid-Open Publication No. Hei 4-249305, a thermoelectric device in which opposite surfaces of a thermoelectric semiconductor are covered with a nitel layer for soldering connection with the corresponding electrode is disclosed.

Conventional techniques as described above are difficult to produce chemically homogeneous thermoelectric materials with homogeneous solid solution due to the segregation of Te during the production of thermoelectric materials using Bi ₂ Te ₃ -Sb ₂ Te ₃ crab alloy, powder manufacturing process and processing process Carrier concentration changes due to the incorporation of impurities in, and in particular, has not fundamentally solved the conventional problem of increasing the manufacturing cost by prolonging the powder manufacturing time and reducing the recovery rate during mechanical processing.

In order to solve the above problems, the present invention is a general-purpose processing apparatus, Bi ₂ Te ₃ -Sb ₂ Te ₃ alloy melting and growth apparatus and hydrogen reduction reactor, hot compression apparatus, An object of the present invention is to provide a coating and processing apparatus and a method of manufacturing a thermoelectric material using the same.

1 is a basic crystal structure of Bi ₂ Te ₃ in the alloy state.

Figure 2 is a detailed view of the alloy melting and growth apparatus of the present invention,

Figure 3 is a detailed view of the hydrogen reduction apparatus of the present invention,

4 is a detailed view of the hot pressing device of the present invention;

5 is a detailed view inside the vacuum chamber of the hot pressing device;

6 is a heating cooling curve of the hot pressing apparatus of the present invention over time;

Figure 7 is a detailed view of the surface treatment process of the present invention

<Explanation of symbols in the drawings>

Computer (1), controller (2), motor (3), reducer (4), bevel gear (5), screw (6), heating section (7), sample tube (8), heating guide (9) , Heater 10, rotary fixture 11, bearing 12, damping device 13, hydrogen reduction controller 20, hydrogen reduction heater 21, graphite heating element 22, multitube 23, exhaust pipe 24, SUS stand 25, nitrogen cylinder 26, hydrogen cylinder 27, vacuum chamber 30, cooling hoses (31, 42), electrode heaters (32, 33, 43), hot pressing device controller (34), exhaust duct 35, cooling section 40, heating section 41, Mo layer 50, Ni layer 51, polymer adhesive layers 52, 54, coin electrode 53

In order to achieve the above object, the present invention uses a Bi ₂ Te ₃ -Sb ₂ Te ₃ alloy melting and growth apparatus and hydrogen reduction reactor, using a hot compression device, coating and processing apparatus. The Bi ₂ Te ₃ -Sb ₂ Te ₃ alloy is melted in a melting apparatus and then reduced in a hydrogen reduction reactor, cooled and powdered by a grinder, and then the powdered Bi ₂ Te ₃ -Sb ₂ Te ₃ alloy is again After growth by charging into the melting apparatus, or maintaining one-way using a hot compression apparatus, and then the ordinary Mo plating and Ni plating to form a Mo and Ni layer on the surface, and then a polymer adhesive layer on the top After forming and then attaching with a coin electrode, and then forming a polymer adhesive layer on top of it, it is a method of manufacturing a thermoelectric material prepared by adhering to the surface consisting of nickel plating layer, ceramic coating layer, SUBSTRATE, aluminum alloy in this order.

Bi ₂ Te ₃ and Sb ₂ Te ₃ have a layered shape (see Fig. 1) with a rhombohedral structure belonging to the space group R3m, which can also be interpreted as a hexagonal structure. The lattice constant of Bi ₂ Te ₃ is a = 0.4399 nm, c = 3.0483 nm, and the lattice constant of Sb2Te3 is a = 0.4262 nm and c = 3.045 nm.

The lattice constants of these solid solutions change linearly between the lattice constants. The solid solution of the two compounds having similar crystal structures is shown in FIG. 1 to form a complete solid solution in the entire composition range while Sb atoms are substituted for Bi atoms.

The stacking order of Bi ₂ Te ₃ . B¹ = A-B²-A = B¹. Where A represents the elements of Group 5 (Bi, Sb) and B represents the elements of Group 6 (Te, Se) in the periodic table. 1 and 2 represent energetically different lattice positions.

In the bond of Bi ₂ Te ₃ , Te² atom is covalently bonded to the surrounding 6 Bi atoms by forming sp ³ d ² hybrid orbit, and Bi atom has 6 Te as adjacent atoms, and covalently bonded with Te¹, Se¹ The bonds have a mixed bond. Therefore, the bond with Te¹ is stronger than that of Te². The Te¹ atom is a covalent-ion bond with three adjacent Bi atoms, and a weak bond between Te¹ and vander waals in the next layer. Thus, the bonds between adjacent Te layers have mechanical weaknesses that easily break along the plane parallel to the c axis because of their weak bonding force.

As mentioned in the previous section, in order to increase the thermoelectric cooling efficiency, the performance index must be large. This figure of merit shows a higher value as Seebeck coefficient and electrical conductivity are lower and thermal conductivity is lower. In the case of p-type, Seebeck coefficient and electrical conductivity generally change according to the hole concentration. However, decreasing the hole concentration increases the Seebeck coefficient and decreases the conductivity. Therefore, the hole concentration should be optimized to obtain high α²σ values. The relationship between charge concentration and thermoelectric properties is shown. Another way to improve the figure of merit is to minimize thermal conductivity. Here, the thermal conductivity may be expressed as the sum of thermal conductivity and lattice thermal conductivity by charge.

K = K _el + K _ph (2-17)

Here, the thermal conductivity due to charge is determined by the Wiedemann-Franz law

K _e = L T (2-18)

Where L is Lorents number and T is absolute temperature. K _ph is a value depending on the nature of the defect. According to the report of the Ioffe Institute, lattice thermal conductivity can be minimized when a solid solution is formed. According to Birkholz, Rosi and Goldsmid, the thermal conductivity due to the lattice at the composition near x = 0.7 in the solid solution of (Bi1xSbx) 2Te3 is reported to be the minimum value. The change in lattice thermal conductivity according to the composition was shown. The absolute values of these three results are different but represent minimum values in the composition around x = 0.7. The absolute values differ from each other because different Lorents numbers are applied. The lowest lattice thermal conductivity at x = 0.7 indicates that the composition at this vicinity is the best p-type composition. According to Smirous et al., An excellent performance index was obtained at 3.58 × 10-3 / K at 4wt% Te and 0.05wt% Ge at x = 0.75 composition, and Rosi, Hocking, etc. were added in excess of 1.75 wt% Se to the same composition. Excellent characteristics were reported as 3.53 × 10 ^-3 / K. On the other hand, in the Sb ₂ Te ₃ -rich composition region, in order to obtain high performance index, Te and Se are added as donor dopants to reduce the hole concentration.

The structure of the Bi ₂ Te ₃ system has anisotropy in which the c-axis is about 7 long on the a-axis, and its characteristics change depending on the crystal direction. It is reported that the Seebeck coefficient does not change significantly depending on the crystallographic direction, but the electrical conductivity and the electrical conductivity are reported to have a large anisotropy. According to Drabble et al., The electrical conductivity of the p-type is 2.7 times greater than that of the vertical direction when arranged parallel to the cleavage plane, and 4.75 times greater than that of the n-type, and the thermal conductivity is also 2.1 times greater. Bi ₂ Te ₃ series thermoelectric devices made of single crystals have excellent characteristics with very high crystal orientation. However, Bi ₂ Te ₃ produced by pressure sintering is expected to degrade thermoelectric properties because crystal grains are arranged randomly.

Jaklovszky reported that the lattice thermal conductivity of p-type Bi ₂ Te ₃ alloys produced by pressure sintering decreased with decreasing grain size. In addition, the behavior of the performance index changes with grain size. The performance index of the p-type material in which the crystals in the pressurized sinter are completely disordered is expected to be 6% lower than that of the material having good crystal orientation, but the result shows a 14% decrease in the performance index. The decrease in the figure of merit is due to the higher electrical resistivity value of the polycrystalline Bi ₂ Te ₃ thermoelectric material manufactured by the actual sintering method than the electrical resistivity predicted assuming the disordered orientation of the grains.

In polycrystalline Bi ₂ Te ₃ thermoelectric materials produced by pressure sintering, the increase in electrical resistivity is mainly due to oxidation of alloy powder. As the size of the powder particles decreases, the amount of oxide increases. Schultz et al. Found that the electrical resistivity increased as a result of oxygen atmosphere heat treatment on single crystal specimens, which had a BCC structure. The cause of the Bi _x O ₃ layer was reported. In addition, Imaizumi et al. Maintained the Bi ₂ Te ₃ alloy powder at 400 ° C for 24 hours in a hydrogen atmosphere before pressurizing and sintered at 500 ° C after reduction, resulting in a lower thermal conductivity than single crystals of the same composition. Electric non-cleaning terms reported almost similar results. It was reported that the Bi ₂ Te ₃ polycrystalline thermoelectric material sintered after reduction was able to obtain a performance index of 2.74 × 10 ^-3 / K, which is the same as the single crystal of the same composition.

The apparatus used in the present invention is an alloy melting and growth apparatus, hydrogen reduction apparatus. It consists of hot pressing equipment and other common grinding, cutting and plating equipment,

The driving part of the alloy melting and growth apparatus has a gear ratio of 1/180 and 1mm / hr-100mm / hr, and the Te segregation generated during ingot manufacturing excludes grain growth barriers caused by dosa. In order to precisely control the temperature range below 1000 ℃ as the reference temperature range, K-type thermocouple was used, and the base portion of the base was made as thin as possible and has a strong temperature range. In order to make one direction, four temperature gradient areas were set at 35 ℃ / ㎝ width, and powder was injected into quartz or graphite jig, and when the manufacturing work for one direction started, there should be no shaking of the device, thus suppressing the operation of the system. In order to configure a separate damping device,

In addition, the seed fixing jig can be used to grow ingots up to 30 mm.

The starting material of the present invention is to use a composition ratio of Bi ₂ Te ₃ -Sb ₂ Te ₃ is 85: 15 wt%.

The compound used in the polymer adhesive layers 52 and 54 of the present invention is a patented patent application No. 10-2000-67172, which is filed by the present applicant as a conductive polymer, and more specifically, polythiophene 50 to 60. Conductive polymer composed of 1% by weight to 5% by weight, 20 to 25% by weight of organic solvent, 10 to 15% by weight of polyurethane, 5 to 7% by weight of polyacrylic, antifoaming agent and surface leveling agent. In this case, an etching process is required, but when the conductive polymer is used, plating on the conductive polymer is possible.

Hereinafter, the present invention will be described in detail with reference to the following examples.

Example 1

First process melting process

The composition of the alloy composition of the starting material of Bi ₂ Te ₃ : Sb ₂ Te ₃ is 85:15 wt% in the melting apparatus at 5 × 10 ^-5 torr under the vacuum condition of 1000 ℃ or less. Hanging in the center of the heating unit 7 and loaded into the sample-containing tube 8 located at the center of the heating unit 7, and then the controller 2 is operated by the instruction of the computer 1, and the motor When 3 is operated, the reducer 4 connected to the motor 3 and the bevel gear 5 connected to the reducer 4 rotate at a speed of 1 to 100 mm / hr, and are connected to the bevel gear 5. Heater 10 formed at the end of the heating portion 7 while the screw 6 is rotated, and at the same time, the heating portion 7 installed at the center portion of the screw 6 moves the sample inner tube 8 up and down. Heated for 36 hours to melt)

Second Process Hydrogen Reduction Process

After cooling the alloy prepared in the first step, it is charged to a hydrogen reduction reactor and 400 to the hydrogen reduction heater 21 and the graphite heating element 22 while supplying nitrogen and hydrogen from the outside as directed by the hydrogen reduction controller 20. After the molten alloy is reduced while heating at 15 ° C. for 15 minutes, the produced gas is hydrogen-reduced while incinerated or discharged through the multitube 23 and the exhaust pipe 24,

Third process grinding process

After cooling, it is pulverized with a conventional grinder to powder

4th Process Growth Process

The powder prepared in the third step was grown in one direction at 1 to 100 mm / hr at 650 to 750 ° C. in a vacuum melt state at 5 × 10 ⁻⁵ torr in the same manner using the apparatus used in the first step, and 280 for 36 hours. Heat treated at 370 DEG C, followed by annealing

(The powder must be injected into the quarts or graphite jig, there should be no shaking for one-way, and damping device 13 is installed in the lower part of the device to suppress the vibration of the system, and the seed fixing jig will grow the ingot up to 30mm. To help)

5th surface treatment process

The thermoelectric material grown as described above is formed on the surface of the alloy by the conventional Mo plating to form the Mo layer 50, and then on the ordinary Ni plating to form the Ni layer 51 thereon, and then on the ordinary After the polymer adhesive layer 52 is formed, ordinary copper plating is performed to form the copper coating layer 53, and then the same conventional polymer adhesive layer 54 is formed on the surface again.

The lower portion of the aluminum, copper, alloy and silver-treated substrate was bonded to the ceramic coating layer and the Ni plating layer formed on the lower portion of the ceramic coating layer, and cut into a predetermined size with a conventional cutter to prepare a thermal conductive material.

Example 2

1st process (melting process);

A composition having an alloy composition ratio of Bi ₂ Te ₃ : Sb ₂ Te ₃ of 85:15 wt% was melted in a melting apparatus at 5 × 10 ^-5 torr in a vacuum state of 1000 ° C. or lower by a rotating fixture 11 at the center of the apparatus. Suspended, loaded in a sample-containing tube 8 located at the center of the heating section 7, and then the controller 2 is operated by the instruction of the computer 1 and the motor 3 is operated by the controller 2. When is activated, the reducer 4 connected to the motor 3 and the bevel gear 5 connected to the reducer 4 rotate at a speed of 1 to 100 mm / hr, and the screw 6 connected to the bevel gear 5. Is rotated, and at the same time by the heater 10 formed at the end of the heating portion 7 while the heating portion 7 installed in the center of the screw 6 moves the sample inner tube 8 up and down. Melting by heating to a rate of 1 ~ 100mm / hr and less than 1000 ℃;

2nd process (hydrogen reduction process)

After cooling the alloy prepared in the first step, it is charged to a hydrogen reduction reactor and 400 to the hydrogen reduction heater 21 and the graphite heating element 22 while supplying nitrogen and hydrogen from the outside as directed by the hydrogen reduction controller 20. The molten alloy was reduced while heating at 15 DEG C for 15 minutes, and the produced gas was then hydrogen-reduced while incinerated or discharged through the multitube 23 and the exhaust pipe 24;

3rd process (grinding process)

Cooled and pulverized in a conventional mill to powder;

4th process (hot pressing process)

The powder prepared in the third process is charged to the vacuum chamber 30 of the thermal voltage accumulator, and in one side of the vacuum chamber 30, a heating part 41 formed of electrode heaters 32, 33, and 43 is formed in a vacuum state of 5 × 10 ^-5 torrt. The electrode is heated to 1150 ° K, and the opposite side forms a cooling part 40 using cooling hoses 31 and 42 to hot-press the cooling to 740 ° K for 3 hours, and the produced gas is exhaust duct ( Through 35),

The devices are operated with a hot press controller 34 to recover the hot pressed thermoelectric material.

5th process (surface treatment process);

After hot-pressing the thermoelectric material as described above, the surface of the alloy is usually Mo-plated to form the Mo layer 50, and then the ordinary Ni plating is formed thereon to form the Ni layer 51 thereon, After forming the polymer adhesive layer 52, the ordinary copper plating process to form the copper coating layer 53, and then again to form the same conventional polymer adhesive layer 54 on the surface,

The lower portion of the aluminum, copper, alloy and silver-treated substrate was bonded to the ceramic coating layer and the Ni plating layer formed on the lower portion of the ceramic coating layer, and cut into a predetermined size with a conventional cutter to prepare a thermal conductive material.

Hereinafter, the apparatus of the present invention will be described with reference to the drawings.

1 is a basic crystal structure of Bi ₂ Te ₃ shown in the alloy state, Figure 2 is a detailed view of the alloy melting and growth apparatus of the present invention, Figure 3 is a detailed view of the hydrogen reduction device of the present invention, Figure 4 is a view of the present invention Figure 5 is a detailed view of the hot pressing device, Figure 5 is a detailed view of the inside of the vacuum chamber of the hot pressing device, Figure 6 is a heating cooling curve of the hot pressing device of the present invention over time, Figure 7 is a detailed surface treatment process of the present invention As shown in the drawings, the computer 1, the controller 2, the motor 3, the speed reducer 4, the bevel gear 5, the screw 6, the heating part 7, the sample inner tube ( 8), heating guide (9), heater (10), rotating fixture (11), bearing (12), damping device (13), hydrogen reduction controller (20), hydrogen reduction heater (21), graphite heating element (22) ), Multi-tube 23, exhaust pipe 24, SUS bag 25, nitrogen cylinder 26, hydrogen cylinder 27, vacuum chamber 30, cooling hoses (31, 42), electrode heaters (32, 33,43), hot press controller (34), exhaust duct (35), It can be seen that shows the parts 40, the heating element (41), Mo layer (50), Ni layer 51, polymeric adhesive layer (52, 54), the same electrode 53.

Looking at the configuration of the present invention is composed of an alloy melting and growth apparatus, conventional grinding apparatus, hydrogen reduction apparatus, hot pressing apparatus, conventional plating apparatus and conventional cutting apparatus, in more detail,

The alloy melting and growth apparatus is connected to the computer 1, the controller 2 for operating the apparatus according to the instruction of the computer, and the controller 2, as shown in FIG. A motor 3 to be operated, a reducer 4 connected to the motor 3, to reduce the speed, a bevel gear 5 to rotate in connection with the reducer 4, and a lower portion of the bevel gear. (6) and the upper part is fixed to the bearing (12) of the cover and the screw (6) for driving the heating part (7) up and down in the middle part,

One side is fixed to the central portion of the screw (6), the other side is fixed to the wall surface formed on one side of the device is fixed by the heating unit guide 9 is moved up and down to rotate the screw (6) A heating unit 7 driven up and down by a heater, a heater 10 formed at an end of the heating unit 7, and a rotating fixture 11 suspended from an upper portion of the center of the apparatus. And a sample inner tube 8 located at the center of the center, a lower part of the apparatus, a lower part of the motor 3, a middle part of the screw 6, and a middle part of one side wall part of the apparatus. Consists of two damping devices (13),

The bevel gear 5 has a gear ratio of 1/180 degrees, a speed of 1 to 180 mm / hr, and a gradient region of the heating part 7 composed of the heater 10 is 45 ° C / Cm or less.

As shown in FIG. 3, the hydrogen reduction apparatus is connected to a SUS stand 25, a hydrogen reduction controller 20 formed inside the SUS stand 25, and a nitrogen cylinder 26 and a hydrogen tank 27 from the outside. A hose for supplying nitrogen and hydrogen, a hydrogen reduction heater 21 and a graphite heating element 22 formed on an upper portion of the SUS stand 25 and heated by an instruction of a hydrogen reduction controller 20; It consists of a multi-tube (23) for discharging the gas generated in the, and an exhaust pipe (24) for incineration of the discharged gas,

As shown in FIG. 4, the hot pressing device includes a vacuum chamber 30, electrode heaters 32 and 33 formed on and under the vacuum chamber 30, and are heated, and the vacuum chamber 30. And a cooling hose 31 to cool the exhaust hose 31, an exhaust duct 35 for discharging gas generated in the vacuum chamber 3, and a hot press controller 34 for manipulating the devices. ),

5 is a powder alloy formed between the cooling unit 40 and the heating unit 41 embedded in the vacuum chamber. The cooling unit 40 and the heating unit 41 are graphite materials, and cooling hoses 42 are respectively formed therein. ), And an electrode heater 43 is built in the hot pressing state in which the powder alloy is heated on one side and cooled on one side.

Since the heating area is as thin as possible and has a strong temperature area, a crucible of 50 mm or less is manufactured, and 35 ° C / Cm is most ideal.

FIG. 6 illustrates a change in temperature with time elapsed during hot pressing as shown in FIG. 5.

7 is a surface treatment detail view of the Mo layer 50 formed on the surface of the thermoelectric material, the Ni layer 51 formed on the Mo layer 50, and the polymer adhesive layer formed on the Ni layer 51 layer ( 52) and the coin electrode 53 formed on the polymer adhesive layers 52 and 54, and the polymer adhesive layer 54 formed on the coin electrode 53.

The polymer adhesive layer 54 is a ceramic coating layer on the lower portion of the aluminum, copper, alloy and silver-treated substrate and the Ni plating layer formed under the ceramic coating layer to produce a thermoelectric material.

The present invention as described above can greatly increase the density of the thermoelectric material, finer grain size and unidirectionality of the thermoelectric material, and improve the mechanical properties of the thermoelectric material and increase the recovery rate at the time of cutting, thereby bringing an effect of improving the productivity of the thermoelectric material. There is.

Claims (6)

delete delete delete delete In the manufacturing method of the thermoelectric material, The first process (melting step); alloy composition ratio of _{Bi 2 Te 3: Sb 2 Te} 3 and 85: a central upper portion of the device from 5 × 10 ^-5 torr vacuum, the composition of 15 wt% in the melting apparatus below 1000 ℃ Suspended by the rotating fixture 11, charged into the sample-embedding tube 8 located at the center of the heating unit 7, and then the controller 2 is operated by the instruction of the computer 1, and the controller ( When the motor 3 is operated by 2), the bevel gear is rotated at a speed of 1 to 100 mm / hr while the reducer 4 connected to the motor 3 and the bevel gear 5 connected to the reducer 4 rotate. Screw (6) connected to the (5) is rotated, and at the same time the heating portion (7) installed in the central portion of the screw (6) end of the heating portion (7) while moving the sample inner tube (8) up and down Heated by a heater 10 formed therein for 36 hours to melt; Second Step (Hydrogen Reduction Step) The hydrogen reduction heater 21 cools the alloy prepared in the first step, loads it into a hydrogen reduction reactor, and supplies nitrogen and hydrogen from the outside as instructed by the hydrogen reduction controller 20. And reducing the molten alloy by heating the graphite heating element at 400 ° C. for 15 minutes, and the generated gas is hydrogen-reduced while incinerated or discharged through the multitube 23 and the exhaust pipe 24. ; Third step (grinding step) After cooling, pulverizing with a conventional pulverizer to powder; 4th process (growth process) 1-100 mm / hr at 650-750 degreeC in the vacuum melting state by the same method using the apparatus used for the said 3rd process using the apparatus used by the 1st process in 5 * 10 <^-5> torr Growing, annealing by heating to 280-370 ° C. for 36 hours; Fifth Step (Surface Treatment Process) The thermoelectric material grown as described above is subjected to a conventional Mo plating treatment on the surface of the alloy to form a Mo layer 50, and then a normal Ni plating treatment thereon to form the Ni layer 51. After forming, the conventional polymer adhesive layer 52 is formed thereon, followed by ordinary copper plating to form the copper coating layer 53, and then on the surface thereof, the same conventional polymer adhesive layer 54 is again formed. After forming A method of manufacturing a thermally conductive material, comprising: attaching a ceramic coating layer to a lower portion of an aluminum, copper, alloy, and silver-treated substrate and a Ni plating layer formed below the ceramic coating layer, and cutting the same to a predetermined size with a conventional cutting machine. A method for producing a thermoelectric material, comprising: a first step (melting step); a composition having a alloy composition ratio of Bi ₂ Te ₃ : Sb ₂ Te ₃ of 85: 15 wt% in a melt apparatus at 5 × 10 ^-5 torr in a vacuum state of 1000; It is suspended by the rotating fixture 11 at the center of the apparatus below the temperature of less than or equal to ℃, charged in the sample tube (8) located in the center of the heating portion 7, and then the controller (1) 2) is operated and the motor 3 is operated by the controller 2, the reducer 4 connected to the motor 3 and the bevel gear 5 connected to the reducer 4 is 1 ~ 100mm / hr While rotating at a speed, the screw 6 connected to the bevel gear 5 is rotated, and at the same time, the heating part 7 installed at the center of the screw 6 moves the sample inner tube 8 up and down. Heating and melting for 36 hours by a heater 10 formed at the end of the heating unit 7; Second Step (Hydrogen Reduction Step) The hydrogen reduction heater 21 cools the alloy prepared in the first step, loads it into a hydrogen reduction reactor, and supplies nitrogen and hydrogen from the outside as instructed by the hydrogen reduction controller 20. And reducing the molten alloy by heating the graphite heating element at 400 ° C. for 15 minutes, and the generated gas is hydrogen-reduced while incinerated or discharged through the multitube 23 and the exhaust pipe 24. ; Third step (grinding step) After cooling, pulverizing with a conventional pulverizer to powder; 4th process (hot pressing process) The powder manufactured in the 3rd process is charged to the vacuum chamber 30 of a thermal voltage accumulator, and one side is comprised of the electrode heaters 32,33,43 in a 5 * 10 <^-5> torrt vacuum state. The heating part 41 is formed and heated to 1150 ° K by an electrode heater, and the opposite side is formed into a cooling part 40 using cooling hoses 31 and 42 to hot-press the cooling to 740 ° K for 3 hours. At this time, the generated gas is discharged through the exhaust duct 35, and the apparatuses are operated by the hot pressing device controller 34 to remove the hot pressed thermoelectric material. 5th process (surface treatment process); After hot-pressing the thermoelectric material as described above, the surface of the alloy is usually Mo-plated to form the Mo layer 50, and then the ordinary Ni plating is formed thereon to form the Ni layer 51 thereon, After forming the polymer adhesive layer 52, the copper plating layer 53 is formed by ordinary copper plating, and then the same conventional polymer adhesive layer 54 is formed on the surface again. A method of manufacturing a thermally conductive material, comprising: attaching a ceramic coating layer to a lower portion of an aluminum, copper, alloy, and silver-treated substrate and a Ni plating layer formed below the ceramic coating layer, and cutting the same to a predetermined size with a conventional cutting machine.