KR102224461B1 - Thermoelectric element thermoelectric moudule using the same, and cooling device using thermoelectric moudule - Google Patents

Abstract

The present invention provides a unit member comprising a semiconductor layer on a substrate; A unit element in which the unit members are stacked and arranged; And a metal intermediate layer interposed between the unit members.
According to the present invention, by forming a metal interlayer containing a glass frit to increase the strength of the leg, it is possible to provide a thermoelectric device and a thermoelectric module with improved strength and improved electrical conductivity. have.

Description

Thermoelectric element, thermoelectric module including the same, and heat conversion device {THERMOELECTRIC ELEMENT THERMOELECTRIC MOUDULE USING THE SAME, AND COOLING DEVICE USING THERMOELECTRIC MOUDULE}

The embodiments of the present invention relate to a thermoelectric device and a thermoelectric module used for cooling.

Devices made of P-type thermoelectric material and N-type thermoelectric material are manufactured in bulk with the same standard even when applied to a cooling device, which is the difference between P-type thermoelectric material and N-type thermoelectric material with different electrical conduction characteristics. As a result, the cooling efficiency is showing a limit.

In particular, in the method of manufacturing such a bulk type thermoelectric device, the material in the form of an ingot is heat treated, pulverized into powder (Ball Mill), then sieved to a fine size, and then subjected to a sintering process, followed by required thermoelectricity. It is manufactured through a process of cutting to the size of the device. In the process of manufacturing such a bulk type thermoelectric element, a large part of material loss occurs during cutting after sintering of the powder, and when mass-producing, the uniformity in terms of the size of the bulk type material decreases, and it is difficult to reduce the thickness of such a thermoelectric element. There was a problem that it was difficult to apply to products requiring slim.

To solve this problem, the thermoelectric material powder is pasted and printed several times to sinter to produce a sheet-shaped thermoelectric material. The sheet thickness can be adjusted by the number of printing, and the sheet-shaped material If you cut and use it, you can manufacture the device without loss of material.

However, if a sintered leg is manufactured by printing a paste thermoelectric material several times, it is difficult to manufacture and use a thermoelectric element because the strength is remarkably poor.

Embodiments of the present invention are to solve the above-described problem, by forming a metal interlayer containing a glass frit to increase the strength of the leg, the strength is improved, and the electrical conductivity is improved. It is possible to provide a thermoelectric device and a thermoelectric module.

In an embodiment of the present invention, in order to achieve the above object, a unit member including a semiconductor layer on a substrate; A unit element in which the unit members are stacked and arranged; And a metal intermediate layer interposed between the unit members.

In addition, the metal intermediate layer is characterized in that the metal electrode.

In addition, the metal is characterized in that it is a mixture of at least one selected from the group consisting of silver (Ag), nickel (Ni), gold (Au), titanium (Ti), and copper (Cu).

In addition, the metal is characterized in that the particle diameter is 150 to 500 ㎚.

In addition, the metal intermediate layer is characterized in that it includes a glass frit (glass frit).

In addition, the composition of the glass frit is characterized by consisting of Bi2O3 and ZnO.

In addition, the content of the composition of the glass frit is characterized in that 40 to 80% by weight of Bi2O3 and 10 to 35% by weight of ZnO.

In addition, the unit device is characterized in that it further comprises a conductive layer on the adjacent unit member.

In addition, the conductive layer is characterized in that it includes a pattern in which the surface of the unit member is exposed.

In addition, the pattern is characterized in that it has a mesh type structure including a closed opening pattern or a line type structure including an open “‡ type opening pattern.

In addition, an embodiment of the present invention includes a first substrate and a second substrate facing each other; Including at least one unit cell comprising a second semiconductor device electrically connected to the first semiconductor device between the first and second substrates, and at least one of the first semiconductor device or the second semiconductor device Provides a thermoelectric module that is the thermoelectric element of any one of claims 1 to 8.

In addition, the first substrate and the second substrate may further include an electrode layer.

In addition, the height of the first semiconductor device and the second semiconductor device is characterized in that 0.01mm ~ 0.5mm.

In addition, an embodiment of the present invention provides a heat conversion device including the thermoelectric module.

According to an embodiment of the present invention, by forming a metal interlayer containing a glass frit to increase the strength of the leg, a thermoelectric element and a thermoelectric module with improved strength and improved electrical conductivity are provided. Can provide.

1 is a conceptual diagram of a manufacturing process of a thermoelectric unit device according to an embodiment of the present invention.
2 is a view showing the shape of a unit device into which a metal intermediate layer is inserted according to an embodiment of the present invention.
3 shows various modifications of the conductive layer (C) according to the embodiment of the present invention.
4 is a schematic cross-sectional view showing a main part of an embodiment in which a thermoelectric module is implemented by applying a thermoelectric device including a unit device according to an embodiment of the present invention.
5 shows an exemplary diagram of a unit device according to an embodiment of the present invention.
6 shows an embodiment of implementing the structure of a thermoelectric module including the unit cell described above in FIG. 4.

Hereinafter, the configuration and operation according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same components are assigned the same reference numerals regardless of the reference numerals, and redundant descriptions thereof will be omitted. Terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component.

In an embodiment of the present invention, a thermoelectric material is manufactured as a leg. In order to minimize the loss, the thermoelectric material is manufactured in a paste state, and the sheets stacked by printing it several times are used as a unit member, and then sintered to reduce the loss. In obtaining the leg, a metal interlayer containing glass frit is inserted between unit members to increase the strength of the leg included in the thermoelectric element. It improves the strength of the device and makes it possible to improve the electrical conductivity.

The metal intermediate layer according to the embodiment of the present invention is in the form of a metal electrode, and the main component is a metal such as silver (Ag), nickel (Ni), gold (Au), titanium (Ti), and copper (Cu), and has a particle diameter of 150 It is preferable to use ~ 500nm. If a particle size smaller than the particle diameter range is used, it is not preferable because the powder aggregates during the process and dispersion does not occur properly.If a particle diameter larger than the particle diameter range is used, the powder particle is large, making it difficult to manufacture a sheet. The electrical conductivity of such a metal electrode is improved after a heat treatment process.

The metal interlayer according to an embodiment of the present invention has a glass frit added to improve strength, which is mainly composed of Bi2O3 and has ZnO as a constituent material. The glass frit according to an embodiment of the present invention may contain 40 to 80% by weight of Bi2O3 and 10 to 35% by weight of ZnO.

If an amount less than the above content is contained, it is not preferable because the sintering temperature varies due to the glass frit, and if a large amount is contained, it is not preferable because it is impossible to control the electrical conductivity.

1 is a conceptual diagram of a manufacturing process of a thermoelectric unit device according to an embodiment of the present invention.

Referring to FIG. 1, a thermoelectric unit device according to an exemplary embodiment of the present invention is a structure having a structure in which multiple layers are stacked, unlike a bulk-type manufacturing process.

In the process of manufacturing such a thermoelectric unit device, a material including a semiconductor material is prepared in the form of a paste, and a semiconductor layer 112 is formed by applying the paste on a substrate 111 such as a sheet or film to form one unit member. Form 110. As shown in FIG. 1, the unit member 110 forms a laminated structure by stacking a plurality of unit members 110a, 110b, and 110c, and then cuts the laminated structure to form a unit device 120. That is, the unit device 120 according to the present invention may be formed as a structure in which a plurality of unit members 110 in which the semiconductor layer 112 is stacked on the substrate 111 are stacked.

In the above-described process, the process of applying the semiconductor paste on the substrate 111 may be implemented using various methods, and as an example, tape casting, that is, a very fine semiconductor material powder, is used in an aqueous or non-aqueous solvent ( solvent), a binder, a plasticizer, a dispersant, a defoamer, or a surfactant to prepare a slurry, and then a moving blade or a moving carrier. It can be implemented as a process of molding according to the purpose of a certain thickness on the top. In this case, the thickness of the substrate may be a material such as a film or sheet in the range of 10 um to 100 um, and the applied semiconductor material may be a P-type semiconductor or an N-type semiconductor material. Such N-type semiconductor materials include selenium (Se), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), and tellurium ( Te), bismuth (Bi), bismuth telluride-based (BiTe-based) including indium (In) and a mixture of Bi or Te corresponding to 0.001 to 1.0 wt% of the total weight of the main raw material It can be formed using For example, the main raw material may be a Bi-Se-Te material, and Bi or Te may be formed by adding a weight corresponding to 00.001 to 1.0 wt% of the total weight of Bi-Se-Te. That is, Bi When the weight of -Se-Te is 100g, it is preferable to add Bi or Te to be further mixed in the range of 0.001g to 1.0g. As described above, the weight range of the material added to the above-described main raw material is significant in that the thermal conductivity is not lowered outside the range of 0.001 wt% to 0.1 wt%, and the electrical conductivity decreases, so that an improvement in the ZT value cannot be expected. Have.

The P-type semiconductor material is antimony (Sb), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), tellurium ( Te), bismuth (Bi), bismuth telluride-based (BiTe-based) including indium (In) and a mixture of Bi or Te corresponding to 0.001 to 1.0 wt% of the total weight of the main raw material It is preferable to form using. For example, the main raw material is a Bi-Sb-Te material, and Bi or Te may be formed by adding a weight corresponding to 0.001 to 1.0 wt% of the total weight of Bi-Sb-Te. That is, when the weight of Bi-Sb-Te is 100 g, the additionally mixed Bi or Te may be added in the range of 0.001 g to 1 g. The weight range of the material added to the above-described main raw material is significant in that the thermal conductivity does not decrease and the electrical conductivity decreases outside the range of 0.001 wt% to 0.1 wt%, so that an improvement in the ZT value cannot be expected.

In addition, the process of arranging and laminating the unit members 110 in multiple layers can be formed into a stacked structure by pressing at a temperature of 50°C to 250°C. In the embodiment of the present invention, the number of stacking of the unit members 110 Can be made in the range of 2 to 50. Thereafter, a cutting process may be performed in a desired shape and size, and a sintering process may be added.

A unit device formed by stacking a plurality of unit members 110 manufactured according to the above-described process can secure uniformity in thickness and shape and size. In other words, the conventional bulk-shaped thermoelectric element cuts the sintered bulk structure after ingot crushing and micronizing ball-mill process. As a result, there are many materials lost in the cutting process, as well as uniformity. It is difficult to cut into one size, and it is difficult to reduce the thickness due to the thickness of 3 mm to 5 mm. However, in the unit device of the stacked structure according to the embodiment of the present invention, a sheet stack is formed after multilayer stacking of sheet-shaped unit members. As it is cut, there is almost no material loss, and since the material has a uniform thickness, the uniformity of the material can be secured, and the thickness of the entire unit device can be reduced to less than 1.5mm, and it can be applied in various shapes. It becomes possible.

As described above, in the manufacturing process of the unit device according to the embodiment of the present invention, a method of forming the metal intermediate layer is as follows. The metal intermediate layer may be disposed by appropriately inserting between the unit members after manufacturing a sheet having a desired thickness. The manufacturing of the metal intermediate layer is a method of manufacturing a sheet using conventional powder such as a casting method. FIG. 2 is a diagram showing the shape of a unit element in which a metal intermediate layer is inserted according to an embodiment of the present invention. As can be seen in the drawing, a sheet-shaped metal manufactured between unit members is formed. By inserting and arranging the intermediate layer, a unit device including a metal intermediate layer having a desired thickness can be manufactured.

As described above, in the manufacturing process of the unit device according to the embodiment of the present invention, a process of forming a conductive layer on the surface of each unit member 110 during the process of forming a stacked structure of the unit members 110 is further included. Can be implemented.

That is, a conductive layer such as the structure of FIG. 3 may be formed between the unit members of the laminated structure of FIG. 1(c). The conductive layer may be formed on the opposite surface of the substrate on which the semiconductor layer is formed, and in this case, the conductive layer may be formed of a patterned layer such that a region where the surface of the unit member is exposed is formed. This makes it possible to increase the electrical conductivity compared to the case where it is applied to the entire surface, and at the same time, it is possible to improve the bonding strength between each unit member, and it is possible to realize the advantage of lowering the thermal conductivity. That is, what is shown in FIG. 3 shows various modified examples of the conductive layer C according to the embodiment of the present invention, and the pattern in which the surface of the unit member is exposed is shown in FIGS. 2A and 2B. As shown in, a mesh-type structure including a closed-type opening pattern (c ₁ , c _{2 ) or an open-type opening pattern (c 3} , c ₄ ) as shown in (c) and (d) of FIG. 3 It can be designed by variously transforming into a line type including a. The above conductive layer has the advantage of not only increasing the adhesion between each unit member, but also lowering the thermal conductivity between the unit members and improving the electrical conductivity inside the unit element formed as a stacked structure of unit members. Compared to the thermoelectric device, the cooling capacity (Qc) and ΔT (℃) are improved, and in particular, the power factor is increased by 1.5 times, that is, the electrical conductivity is increased by 1.5 times. The increase in electrical conductivity is directly connected to the improvement of the thermoelectric efficiency, thereby improving the cooling efficiency.

4 is a cross-sectional conceptual view showing a main part of an embodiment in which a thermoelectric module is implemented by applying a thermoelectric device including a unit device according to an embodiment of the present invention.

The thermoelectric module including the thermoelectric device according to the embodiment of the present invention includes a first substrate 140 and a second substrate 150 facing each other, and a first substrate between the first substrate 140 and the second substrate 150. A unit cell including the second semiconductor device 130 electrically connected to the semiconductor device 120 may be formed in a structure including at least one or more. That is, the embodiment of FIG. 4 shows only one of the unit cells. In particular, in this case, in the thermoelectric module according to an embodiment of the present invention, at least one of the first semiconductor device and the second semiconductor device may be applied to the thermoelectric device of the stacked structure described in FIG. 1.

In the case of the cooling thermoelectric module, the first substrate 140 and the second substrate 150 may use an insulating substrate, such as an alumina substrate, or, in the case of an embodiment of the present invention, heat dissipation efficiency and heat dissipation efficiency and It can be made to be able to implement thinning.

Of course, in the case of forming a metal substrate, dielectric layers 170a and 170b are further included between the electrode layers 160a and 160b formed on the first and second substrates 140 and 150 as shown in FIG. 4. It is preferable that it is formed. In the case of a metal substrate, Cu or a Cu alloy may be applied, and a thickness capable of thinning may be formed in the range of 0.1mm to 0.5mm. In this case, when the thickness of the metal substrate is 0.1mm or thinner, or when the thickness exceeds 0.5mm, the heat dissipation characteristic is too high or the thermal conductivity is too high, so that the reliability of the thermoelectric module is greatly reduced.

In addition, in the case of the dielectric layers 170a and 170b, a material having a thermal conductivity of 5 to 10 W/K is used as a dielectric material having high heat dissipation performance, considering the thermal conductivity of the cooling thermoelectric module, and the thickness is 0.01 mm to 0.15. It can be formed in the range of mm. In this case, if the thickness is less than 0.01mm, the insulation efficiency (or withstand voltage characteristic) is significantly lowered, and if it exceeds 0.15mm, the thermal conductivity is lowered and the heat dissipation efficiency is lowered.

The electrode layers 160a and 160b electrically connect the first semiconductor device and the second semiconductor device using electrode materials such as Cu, Ag, and Ni, and when a plurality of illustrated unit cells are connected (refer to FIG. 6), they are adjacent to each other. It is to form an electrical connection with the unit cell.

The thickness of the electrode layer may be formed in a range of 0.01mm to 0.3mm. If the thickness of the electrode layer is less than 0.01mm, the function as an electrode is deteriorated, resulting in poor electrical conductivity. Even if it exceeds 0.3mm, the conduction efficiency decreases due to an increase in resistance.

In this way, when the thermoelectric device according to the embodiment of the present invention is disposed between the first substrate 140 and the second substrate 150 and the thermoelectric module is implemented as a unit cell having a structure including an electrode layer and a dielectric layer, Since the thickness (Th) can be formed in the range of 1.mm to 1.5mm, it is possible to realize a remarkable thinning compared to using the existing bulk type device.

In addition, as shown in FIG. 5, the thermoelectric elements 120 and 130 described above in FIG. 3 are horizontally arranged in an upper direction (X) and a lower direction (Y), as shown in FIG. 5A. As a result, a thermoelectric module can be formed in a structure in which the first and second substrates, the semiconductor layer, and the surface of the substrate are disposed adjacent to each other, but as shown in (b), the thermoelectric element itself is vertically erected, It is also possible to have a structure such that the side portions of the are disposed adjacent to the first and second substrates. In such a structure, the distal end of the conductive layer is exposed on the side surface than in the horizontal arrangement structure, and the heat conduction efficiency in the vertical direction can be lowered and the electrical conduction characteristics can be improved, thereby further increasing the cooling efficiency.

6 illustrates an embodiment of implementing the structure of a thermoelectric module including the unit cell described above in FIG. 4. As shown in FIG. 6, in a thermoelectric module using a thermoelectric element generally used for cooling, semiconductor elements having different materials and characteristics are arranged in pairs, and each of the semiconductor elements forming the pair is formed by a metal electrode. It may be implemented in a structure in which a plurality of unit cells that are electrically connected are arranged. That is, FIG. 6 is an exemplary diagram of a thermoelectric module implemented in a structure including at least two unit cells including a second semiconductor device 130 electrically connected to the first semiconductor device 120 in FIG. 4.

In particular, in this case, the thermoelectric element constituting the unit cell can be applied to a thermoelectric element including a unit element having a stacked structure according to an embodiment of the present invention, and in this case, one side is the first semiconductor element 120, which is a P-type semiconductor. And the second semiconductor device 130 may be composed of an N-type semiconductor, and the first semiconductor and the second semiconductor are connected to the metal electrodes 160a and 160b, and a plurality of such structures are formed, and electrodes are formed on the semiconductor device. The Peltier effect is implemented by circuit lines 181 and 182 through which current is supplied.

In the thermoelectric module according to the embodiment of the present invention, the thermoelectric device including the unit device of the stacked structure described above in FIGS. 1 to 5, and the thermoelectric device in which a conductive layer is formed between the unit members may be included. It has been described above. In addition, the shape and size of the first and second semiconductor devices that form a unit cell and face each other are the same, but in this case, the electrical conductivity of the P-type semiconductor device and the electrical conductivity of the N-type semiconductor device are different from each other. Considering that it acts as a factor that hinders efficiency, it is also possible to improve the cooling performance by forming one volume different from the volume of the other semiconductor devices facing each other.

In other words, forming different volumes of semiconductor devices of unit cells arranged opposite to each other greatly differs in overall shape, or in semiconductor devices having the same height, the diameter of one cross section is wide, or the same shape In a semiconductor device, it is possible to implement a different height or cross-sectional diameter. In particular, the diameter of the N-type semiconductor device is made larger than that of the P-type semiconductor device to increase the volume, thereby improving thermoelectric efficiency.

The thermoelectric elements of various structures and the thermoelectric module including the same according to an embodiment of the present invention described above take heat from a medium such as water or liquid according to the characteristics of the heat generating and heat absorbing part on the surface of the substrate above and below the unit cell. It can be used for implementing cooling or for heating by transferring heat to a specific medium. That is, in the thermoelectric module of various embodiments of the present invention, the configuration of a cooling device that is implemented by improving cooling efficiency is described as an embodiment, but the substrate on the opposite side where cooling is performed is used to heat a medium by using a heat generating property. Applicable to your device. That is, it can be applied to equipment such as a heat conversion device that implements cooling and heating functions simultaneously in one device.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for describing the present invention in more detail, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited by these examples according to the gist of the present invention. .

[Example]

1. Ingot manufacturing

Composition of the composition: Bi, Sb, Te mixture

Content of ingredients: Bi: 12.64wt%, Sb: 29.46wt%, Te: 57.89wt%

Equipment Used: Rocking Furnace

Temperature: 800℃ / Heating rate: 3℃/hr / Process time: 10hr / Cooling: Rapid cooling

2. Multi layer manufacturing

Composition of the composition: Bi, Sb, Te mixture used

Process: Powder Mixing -->Casting -->Stacking -->Water purification -->BBO -->Heat treatment

3. Example (Metal layer) preparation

After proceeding to the casting process using matal powder, make a sheet

In the case of the metal layer, casting is performed in the multilayer manufacturing process above, and then the sheeted metal electrode (Glass frit) is stacked together when stacking is performed in the above multilayer manufacturing process to proceed with the processes of water purification, cutting, BBO, and heat treatment.

[Experiment method]

1. Measurement of sample breaking pressure

Measure the breakdown pressure of the sample using Instron instruments

2. Resistivity measurement

Measurement using ZEM-3 equipment

These measurement results are summarized below.

[Experiment result]

sample Sample breaking pressure Ingot 40Mpa Multilayer thermoelectric material 17~20Mpa Example (Metal layer formation) 30~33Mpa

sample Resistivity Multilayer thermoelectric material 40μΩ Example (Metal layer formation) 10μΩ

As can be seen from the above experimental results, the thermoelectric device according to the embodiment of the present invention has an increased breakdown pressure and a reduced resistivity compared to the multilayer thermoelectric device manufactured by the conventional method.

In the detailed description of the present invention as described above, specific embodiments have been described. However, various modifications are possible without departing from the scope of the present invention. The technical idea of the present invention is limited to the above-described embodiments of the present invention and should not be defined, and should not be defined by the claims as well as the claims and equivalents.

Claims (14)

A unit member including a semiconductor layer on a substrate;
A unit element in which the unit members are stacked and arranged; And
Metal intermediate layer interposed and disposed between the unit members
Thermoelectric device comprising a.
The method of claim 1,
The thermoelectric device, wherein the metal intermediate layer is a metal electrode.
The method of claim 2,
The metal is a thermoelectric device, characterized in that at least one mixture selected from the group consisting of silver (Ag), nickel (Ni), gold (Au), titanium (Ti), and copper (Cu).
The method of claim 3,
The thermoelectric device, wherein the metal has a particle diameter of 150 to 500 nm.
The method of claim 1,
The thermoelectric device, wherein the metal intermediate layer includes a glass frit.
The method of claim 5,
The composition of the glass frit is a thermoelectric device, characterized in that consisting of Bi2O3 and ZnO.
The method of claim 6,
The thermoelectric device, characterized in that the content of the composition of the glass frit is 40 to 80% by weight of Bi2O3 and 10 to 35% by weight of ZnO.
The method of claim 1,
The unit device,
Thermoelectric device, characterized in that it further comprises a conductive layer on the adjacent unit member.
The method of claim 8,
The conductive layer,
A thermoelectric device comprising a pattern in which the surface of the unit member is exposed.
The method of claim 9,
The pattern is,
A thermoelectric device having a mesh type structure including a closed opening pattern or a line type structure including an open “‡ type opening pattern.
A first substrate and a second substrate facing each other;
And at least one unit cell including a second semiconductor device electrically connected to the first semiconductor device between the first and second substrates, and
At least one of the first semiconductor device and the second semiconductor device is a thermoelectric module according to any one of claims 1 to 8.
The method of claim 11,
The first substrate and the second substrate further comprises an electrode layer.
The method of claim 11,
The thermoelectric module, wherein the first semiconductor device and the second semiconductor device have a height of 0.01mm to 0.5mm.
A heat conversion device comprising the thermoelectric module according to claim 11.

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