KR20210133944A - Method for fabricating thermoelectric element and thermoelectric element and thermoelectric module made thereby - Google Patents

Abstract

An objective of the present invention is to provide a method for manufacturing a thermoelectric element, and a thermoelectric element and thermoelectric module manufactured thereby to increase the manufacturing yield of the thermoelectric element. According to one embodiment of the present invention, the method for manufacturing the thermoelectric element comprises: a molding step of molding an extruded material (10) in a form of an ingot; a cutting step of cutting the extruded material (10) into a unit material (20) after forming an insulating film (11) on the side of the extruded material (10); and a forming step of manufacturing a thermoelectric element (30) by forming a diffusion barrier layer (21) on a cut surface of the unit material (20).

Description

Thermoelectric element manufacturing method, thermoelectric element and thermoelectric module manufactured therewith

The present invention relates to a method for manufacturing a thermoelectric element, a thermoelectric element and a thermoelectric module using the same, and more particularly, to prepare an extruded material having the same cross-sectional area as a thermoelectric element, and use the same to manufacture a thermoelectric element to increase the thermoelectric element manufacturing yield For this purpose, it relates to a method for manufacturing a thermoelectric element, a thermoelectric element and a thermoelectric module using the same.

In addition, the present invention relates to a method for manufacturing a thermoelectric element, a thermoelectric element and a thermoelectric module using the same, for manufacturing a thermoelectric material sintered body 40 and manufacturing a thermoelectric element using the same to increase a thermoelectric element manufacturing yield.

The thermoelectric phenomenon is a phenomenon that occurs by the movement of electrons and holes inside a material, and refers to direct energy conversion between heat and electricity.

A thermoelectric module is a generic term for devices using a thermoelectric phenomenon, and has a structure in which a P-type thermoelectric element and an N-type thermoelectric element are bonded between metal electrodes to form a PN junction pair.

The thermoelectric module can be divided into a device using a temperature change of electrical resistance, a device using the Seebeck effect, a phenomenon in which electromotive force is generated by a temperature difference, and a device using the Peltier effect, a phenomenon in which heat absorption or heat is generated by current. .

Thermoelectric modules are widely applied to home appliances, electronic parts, and communication parts. For example, the thermoelectric element may be applied to an apparatus for cooling, an apparatus for heating, an apparatus for power generation, and the like, and a thermoelectric element having flexibility may be applied to various structures having curved surfaces. Accordingly, the demand for the thermoelectric performance of the thermoelectric element is increasing.

Currently, a thermoelectric element applied to a commercial bismuth telluride-based (Bi ₂ Te ₃ ) (ie, Bi-Te-based) thermoelectric module is manufactured by the process shown in FIG. 1 . 1 is a view for explaining a process of manufacturing a cuboid-shaped thermoelectric element from an ingot-shaped thermoelectric material.

Specifically, when a thermoelectric element is manufactured using an ingot-type thermoelectric material, both ends of the ingot having non-uniform thermoelectric performance are removed. In this case, about 20% of the total thermoelectric material is removed.

Next, a wafer is manufactured through slicing according to the thickness of the thermoelectric element. In this case, 13% is removed again, leaving 67% of the total thermoelectric material.

Next, a diffusion barrier layer is coated on both sides of the wafer.

Next, the wafer coated with the diffusion barrier layer is diced according to the area of the thermoelectric element. In this case, 12% is removed again, leaving 55% of the total thermoelectric material.

Finally, a thermoelectric element is manufactured through a sorting process. In this case, 15% is removed, leaving a level of 40% of the total thermoelectric material, and the process of manufacturing a cuboid-shaped thermoelectric element from an ingot-shaped thermoelectric material shows a yield of 40%.

As described above, since the n-type and p-type Bi-Te-based thermoelectric devices used in the thermoelectric module require several steps of processing after manufacturing the ingot, the thermoelectric device manufacturing yield is remarkably reduced.

In addition, the thermoelectric element manufactured in this way is subjected to several processing steps, so that dew condensation may occur depending on the external environment, which may cause performance degradation, or damage to the thermoelectric material may occur from external impurities.

Therefore, it is necessary to improve the manufacturing yield by reducing the number of processing steps for cutting the thermoelectric material over several steps, and to remove factors that may decrease performance that may occur during various processes.

Korean Patent Publication No. 10-1051010 (2011.07.15)

An object of the present invention is to manufacture an extruded material having the same cross-sectional area as a thermoelectric element, and to manufacture a thermoelectric element using the same to increase the thermoelectric element manufacturing yield, a method for manufacturing a thermoelectric element, a thermoelectric element and a thermoelectric module using the same. .

In addition, another object of the present invention relates to a method for manufacturing a thermoelectric element, a thermoelectric element using the same, and a thermoelectric module for manufacturing a thermoelectric material sintered body and increasing the thermoelectric element manufacturing yield by manufacturing a thermoelectric element using the same.

A method of manufacturing a thermoelectric element according to an embodiment of the present invention includes a molding step of molding an extruded material 10 in the form of an ingot; After forming the insulating film 11 on the side of the extruded material 10, cutting step of cutting the extruded material 10 into a unit material (20); and a forming step of manufacturing the thermoelectric element 30 by forming the diffusion barrier layer 21 on the cut surface of the unit material 20 .

The extruded material 10 may have a composition component determined according to the type of the thermoelectric element 30 .

The extruded material 10 may have a circular or polygonal cross-sectional shape.

The extruded material 10 may be made by press-molding the powder into a rod shape through an extruder, and then heating and sintering.

The cutting step may be to generate the unit material 20 by cutting the extruded material 10 to the height of the thermoelectric element 30 while moving it in the longitudinal direction.

A cross-sectional area of the extruded material 10 may be the same as that of the thermoelectric element 30 .

The forming step may be to form the diffusion barrier layer 21 through barrel plating in which the unit material 20 is put into a barrel containing the diffusion barrier layer plating liquid and the cut surface is plated with the diffusion barrier layer plating liquid. .

In addition, a method for manufacturing a thermoelectric element according to another embodiment of the present invention includes a forming step of forming a sintered body 40 of a thermoelectric material; a first cutting step of cutting the thermoelectric material sintered body 40 to form a slicing material 41; a second cutting step of forming an insulating film 42 on a side surface of the slicing material 41 and then cutting the slicing material 41 into a unit material 50; and a forming step of manufacturing the thermoelectric element 60 by forming the diffusion barrier layer 51 on the cut surface of the unit material 50 .

The thermoelectric material sintered body 40 may have a composition component determined according to the type of the thermoelectric element 60 .

The thermoelectric material sintered body 40 may be made by press-molding a powder body into a wafer shape and then heating and sintering the powder body.

In the first cutting step, the thermoelectric material sintered body 40 may be sliced in one direction and processed into a slicing material 41 having a rectangular cross-section and a rod shape.

The second cutting step may be to generate the unit material 50 by cutting the slicing material 41 to the height of the thermoelectric element 60 while moving it in the longitudinal direction.

A cross-sectional area of the slicing material may be the same as a cross-sectional area of the thermoelectric element.

The forming step may be to form the diffusion barrier layer 51 through barrel plating in which the unit material 50 is put into a barrel containing the diffusion barrier layer plating liquid and the cut surface is plated with the diffusion barrier layer plating liquid. .

According to the present invention, an extruded material having the same cross-sectional area as a thermoelectric element may be manufactured, and a thermoelectric element may be manufactured using the same, thereby increasing the thermoelectric element manufacturing yield.

In addition, another object of the present invention is to manufacture a sintered body of a thermoelectric material and use the same to manufacture a thermoelectric device, thereby increasing the thermoelectric device manufacturing yield.

1 is a view for explaining a process of manufacturing a rectangular parallelepiped thermoelectric element from an ingot-shaped thermoelectric material;
2 is a view for explaining a method of manufacturing a thermoelectric element according to an embodiment of the present invention;
3 is a view for explaining a method of manufacturing a thermoelectric element according to another embodiment of the present invention;
4 is a view showing a thermoelectric module using a thermoelectric element manufactured according to the method of FIG. 2;
FIG. 5 is a view showing a thermoelectric module using a thermoelectric element manufactured according to the method of FIG. 3 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, detailed descriptions of well-known functions or configurations that may obscure the gist of the present invention in the following description and accompanying drawings will be omitted. Also, it should be noted that throughout the drawings, the same components are denoted by the same reference numerals as much as possible.

The terms or words used in the present specification and claims described below should not be construed as being limited to conventional or dictionary meanings, and the inventor shall appropriately define his or her invention in terms of the best way to describe it. Based on the principle that it can be done, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all the technical ideas of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

In the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated, and the size of each component does not fully reflect the actual size. The present invention is not limited by the relative size or spacing drawn in the accompanying drawings.

When a part "includes" a certain element throughout the specification, this means that other elements may be further included, rather than excluding other elements, unless otherwise stated. In addition, when a part is said to be "connected" with another part, it includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element interposed therebetween.

The singular expression includes the plural expression unless the context clearly dictates otherwise. Terms such as “comprise” or “have” are intended to designate that a feature, number, step, action, component, part, or combination thereof described in the specification is present, and includes one or more other features, numbers, or steps. , it should be understood that it does not preclude in advance the possibility of the existence or addition of an operation, component, part, or combination thereof.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the embodiments of the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a view for explaining a method of manufacturing a thermoelectric element according to an embodiment of the present invention.

As shown in FIG. 2, the method for manufacturing a thermoelectric element according to an embodiment of the present invention manufactures a similar type extruded thermoelectric material (ie, extruded material) 10 having the same cross-sectional area as the thermoelectric element, By using this, the thermoelectric element 30 can be manufactured to increase the thermoelectric element manufacturing yield.

First, in step S1, the extruded material 10 having the same cross-sectional area as the thermoelectric element to be manufactured is molded through an extruder.

The composition of the extruded material 10 is determined according to the type of the thermoelectric element. That is, the extruded material 10 is molded with a composition component for manufacturing an n-type thermoelectric element containing an n-type semiconductor material or a p-type thermoelectric element containing a p-type semiconductor material. For example, the n-type thermoelectric element is selenium (Se), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), tell Materials made of bismuth telluride (BiTe) including rurium (Te), bismuth (Bi), and indium (In) are included, and the p-type thermoelectric element is antimony (Sb), nickel (Ni), aluminum (Al) Bismuth-telluride-based (BiTe-based) including copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), tellurium (Te), bismuth (Bi), and indium (In) ) may be included.

The extruded material 10 is made by pressing the powder into an appropriate shape (here, a rod shape) through an extruder and then heating and sintering. In this case, the extruded material 10 may have a circular or polygonal cross-sectional shape.

Next, step S2 forms the insulating film 11 on the side of the extruded material 10 .

Since the extruded material 10 contains an n-type or p-type semiconductor material and has electrical conductivity on the surface, an insulating film 11 is thinly formed on the surface for electrical insulation. Here, the insulating layer 11 may be formed through a dry process (eg, PECVD) or a wet process (eg, spin coating), and may be, for example, a thin film such as _{SiO 2} , Si ₃ N _{4 , or SiON.}

Next, in step S3 , the extruded material 10 on which the insulating film 11 is formed is cut (or sliced) to have the height of the thermoelectric element to produce the unit material 20 . That is, step S3 is a cutting step, and the unit material 20 is generated by cutting the extruded material 10 to the height of the thermoelectric element while moving along the longitudinal direction.

Here, the height of the thermoelectric element corresponds to the height of the unit material 20 to be described later, and corresponds to the gap between the metal electrodes formed on the upper part and the lower part when the thermoelectric module is formed. As such, the size of the unit material 20 corresponds to the size of the thermoelectric element.

In Figure 2, one extruded material 10 is manufactured in a plurality of unit material 20 in the form of a cylinder.

Through the processing step of step S3, the insulating film 11 is maintained on the side surface of the unit material 20, and the top and bottom surfaces are cut surfaces formed through cutting. As such, the insulating film 11 is not formed on the upper and lower surfaces of the unit material 20 .

The insulating film 11 formed on the side of the unit material 20 serves to hermetically seal so that moisture cannot penetrate, so that the side of the unit material 20 is immersed in the diffusion barrier layer plating solution in step S4 to form a diffusion barrier layer. doesn't happen

On the other hand, the upper and lower surfaces of the unit material 20 correspond to the surfaces in direct contact with the electrodes of FIGS. 4 and 5, which will be described later, and thus need to form a diffusion barrier layer, which is immersed in the diffusion barrier layer plating solution in step S4. When the diffusion barrier layer 21 is formed.

Through this, when the unit material 20 formed through steps S2 and S3 is immersed in the diffusion barrier layer plating solution in step S4, plating is selectively performed only on the portion where the diffusion barrier layer is to be formed. Accordingly, there is no need to remove the diffusion barrier layer formed on the side surface of the unit material 20 after step S4.

As described above, step S4 forms the diffusion barrier layer 21 on the cut surfaces (ie, upper and lower surfaces) of the unit material 20 . Here, the diffusion barrier layer plating solution may be any one of nickel (Ni), titanium (Ti), or a mixed alloy material. The diffusion barrier layer 21 is formed to prevent deterioration of thermoelectric performance due to material diffusion between thermoelectric materials.

Step S4 proceeds through barrel plating, in which a plurality of unit materials 20 are put into a barrel containing a diffusion barrier plating solution, and then power is applied to the rotating barrel to form a plurality of units. The cut surface of the material 20 is plated at the same time. As described above, since the insulating film 11 is formed on the side surface of the unit material 20, the diffusion barrier layer 21 is not formed.

Next, in step S5 , after forming the diffusion barrier layer 21 on the cut surface of the unit material 20 , impurities or foreign substances are removed to finally manufacture the thermoelectric element 30 .

As such, loss of material occurs by cutting and processing the extruded material 10 through slicing only in step S3 described above. That is, in one embodiment of the present invention, since material loss occurs only in step S3 among steps S1 to S5, it can be seen that the manufacturing yield of the thermoelectric element can be increased to 80% or more when the manufacturing yield of FIG. 1 is considered. .

3 is a view for explaining a method of manufacturing a thermoelectric element according to another embodiment of the present invention.

As shown in FIG. 3 , in the method for manufacturing a thermoelectric element according to another embodiment of the present invention, a thermoelectric material sintered body 40 is manufactured, and a thermoelectric element is manufactured using the same, thereby increasing the thermoelectric element manufacturing yield.

First, in step S11, the thermoelectric material sintered body 40 is formed. In the thermoelectric material sintered body 40 , like the extruded material 10 , the composition of the thermoelectric material is determined according to the type of the thermoelectric element. That is, the thermoelectric material sintered body 40 is formed with a composition component for manufacturing an n-type thermoelectric element containing an n-type semiconductor material or a p-type thermoelectric element containing a p-type semiconductor material. For example, the n-type thermoelectric element is selenium (Se), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), tell Materials made of bismuth telluride (BiTe) including rurium (Te), bismuth (Bi), and indium (In) are included, and the p-type thermoelectric element is antimony (Sb), nickel (Ni), aluminum (Al) Bismuth-telluride-based (BiTe-based) including copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), tellurium (Te), bismuth (Bi), and indium (In) ) may be included.

The thermoelectric material sintered body 40 is made by, for example, press-molding a powder into an appropriate shape (here, a wafer shape) and then heating and sintering.

Next, in step S12, a plurality of slicing materials 41 are generated by slicing the sintered body 40 of the thermoelectric material in the form of a wafer in one direction. Step S12 corresponds to the first cutting step.

The slicing material 41 corresponds to the extruded material 10 described above, has a rectangular cross-sectional shape, and is formed in a bar shape in the slicing direction (ie, the longitudinal direction). That is, the cross-sectional area of the slicing material 41 is the same as the cross-sectional area of the thermoelectric element. Here, the cross-sectional area of the thermoelectric element is the area of the cut surface of the unit material 50 to be described later, and corresponds to the area of the surface bonded to the metal electrode when the thermoelectric module is formed.

Next, in step S13 , the insulating film 42 is formed on the side surface of the slicing material 41 . Here, the description of the insulating layer 42 overlaps with that described above, and thus a detailed description thereof will be omitted.

Next, in step S14 , the slicing material 41 on which the insulating film 42 is formed is cut again to have the height of the thermoelectric element to generate the unit material 50 . Step S14 corresponds to the second cutting step. That is, in step S14, the unit material 50 is generated at the height of the thermoelectric element while moving the slicing material 41 in the longitudinal direction.

Here, the height of the thermoelectric element corresponds to the height of the unit material 50 , and corresponds to the gap between the metal electrodes formed on the upper part and the lower part when the thermoelectric module is formed.

As such, the size of the unit material 50 corresponds to the size of the thermoelectric element.

In FIG. 3 , a plurality of unit materials 50 in the form of a cuboid is manufactured for one slicing material 41 .

Next, in step S15 , the diffusion barrier layer 51 is formed on the cut surfaces (ie, upper and lower surfaces) of the unit material 50 . Step S15 proceeds through barrel plating, and a detailed description thereof is redundant with the above description, and thus a detailed description thereof will be omitted.

Next, in step S16 , after forming the diffusion barrier layer 51 on the cut surface of the unit material 50 , impurities or foreign substances are removed to finally manufacture the thermoelectric element 60 .

On the other hand, material loss occurs through slicing in steps S12 and S14 described above. That is, in another embodiment of the present invention, since material loss occurs twice in steps S12 and S14 among steps S11 to S16, the manufacturing yield of the thermoelectric element is 40 when comparing the processing process three or more times in FIG. 1 . % or more can be expected.

FIG. 4 is a view showing a thermoelectric module using a thermoelectric element manufactured according to the method of FIG. 2 , and FIG. 5 is a view showing a thermoelectric module using a thermoelectric element manufactured according to the method of FIG. 3 .

4 and 5, the Bi-Te-based thermoelectric module forms a PN junction pair by bonding a p-type thermoelectric element and an n-type thermoelectric element manufactured according to the method of FIGS. 2 and 3 between metal electrodes. . The diffusion barrier layers formed on the top and bottom surfaces of the p-type thermoelectric element and the n-type thermoelectric element are bonded to the metal electrodes through the bonding layer. Then, each of the metal electrodes formed on the upper and lower portions is bonded to the upper insulating substrate and the lower insulating substrate made of a ceramic material.

Although the foregoing description has focused on novel features of the invention as applied to various embodiments, those skilled in the art will recognize the apparatus and method described above without departing from the scope of the invention. It will be understood that various deletions, substitutions, and changes are possible in the form and details of Accordingly, the scope of the invention is defined by the appended claims rather than by the description above. All modifications within the scope of equivalents of the claims are included in the scope of the present invention.

10 ; extruded material 11,42; insulating film
20,50 ; Unit material 21,51 ; diffusion barrier layer
30,60 ; thermoelectric element 40 ; Thermoelectric material sintered body
41 ; slicing material

Claims (1)

A forming step of forming the thermoelectric material sintered body (40);
a first cutting step of cutting the thermoelectric material sintered body 40 to form a slicing material 41;
a second cutting step of forming an insulating film 42 on a side surface of the slicing material 41 and cutting the slicing material 41 into a unit material 50; and
a forming step of manufacturing a thermoelectric element 60 by forming a diffusion barrier layer 51 on a cut surface of the unit material 50; including,
The thermoelectric material sintered body 40 is made by press-molding the powder into a wafer shape and then heating and sintering,
A cross-sectional area of the slicing material 41 is the same as that of the thermoelectric element 60, and the insulating film 11 is any one of _{SiO 2} , Si ₃ N _{4 , and SiON,}
The insulating film 42 is not formed on the upper surface and the lower surface forming the cut surface of the unit material 50,
The forming step is
The unit material 50 is put into a barrel containing the diffusion barrier layer plating solution, and the diffusion barrier layer 51 is formed through barrel plating in which the cut surface is plated with the diffusion barrier layer plating liquid, and the diffusion barrier layer plating liquid is nickel ( Ni), any one of titanium (Ti), or a mixed alloy material,
The method for manufacturing a thermoelectric element, characterized in that the diffusion barrier layer is not formed even if the side surface of the unit material (50) is immersed in the diffusion barrier layer plating solution.

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