KR101153720B1 - A thermoelectric Module and Method for fabricatingA thermoelectric Module and Method for fabricating thereof thereof - Google Patents

Abstract

The thermoelectric module according to the present invention includes an upper substrate and a lower substrate which form an upper / lower surface and generate heat or endotherm, an electrode for guiding the flow of power supplied and provided on one surface of the upper substrate and the lower substrate, and between the electrodes. And a conductive layer provided on at least one end of each of the P-type and N-type thermal semiconductors spaced apart from each other, and extending the contact area with the upper or lower substrate. It is characterized by.

Description

Thermoelectric module and method for manufacturing the same

The present invention has a conductive layer having excellent electrical conductivity at the ends of the P-type and N-type thermoconductors formed by the screen printing process to maximize the area of electrical conductivity by widening the contact area with the substrate and its manufacture. It is about a method.

Thermoelectric materials, which are energy conversion materials that generate temperature differences between materials when electric energy is generated when a temperature difference is applied between materials, and conversely, when electrical energy is applied to materials, have been actively studied.

Recently, thermoelectric materials have been used as special power supplies using thermoelectric power generation, precise temperature control using thermoelectric cooling, computer-related compact coolers, optical communication laser chillers, chillers of cold / hot water machines, and semiconductor thermostats. It is widely used in the form.

A thermoelectric module is a bulk module for assembling pieces of a few mm size obtained by cutting and processing a bulk thermoelectric material, a thin film module composed of a thermoelectric material having a thickness of 10 μm or less, and a thick film having a height of tens to 500 μm. There is a module.

Among the various modules, the thick-film module has attracted much attention as a thin and light electronic device or a CPU cooling control device in the thermoelectric cooling field. That is, the thickness of the thermoelectric material limited in the thin film module is difficult to effectively remove the heat flux generated during the operation of the module. To this end, a thick film having a height of at least several tens of micrometers is required.

However, in forming a thick film module, the conventional thin film process is difficult to obtain a thick film of several tens of micrometers or more due to the slow deposition rate. Similarly, conventional bulk is burdened by the technology and cost of processing thermoelectric elements of tens to hundreds of microns in size.

Therefore, in recent years, a screen printing process has been used to manufacture a thick film module.

That is, Korean Patent Laid-Open Publication No. 10-2008-0093512 discloses a "method of manufacturing a thermoelectric module" to form a P-type semiconductor and an N-type semiconductor by a screen printing method to enable a thin film.

In more detail, the thick film type thermoelectric module is a technology that enables large-area coating and greatly reduces production costs. P-type and N-type thermoelectric powders are paste-pasted and sintered to form P-type and N-type thermoelectric powders. The type elements bond each coated substrate to each other to form a thermoelectric module.

However, the thick film type thermoelectric module using the screen printing process as shown in FIG. 1 has the following problems.

1 is a schematic view showing the internal bonding state of the thermoelectric module manufactured according to the prior art, in the case of the thick film manufactured by the screen printing occurs when the coating thickness of the P-type thermoelectric semiconductor and the thickness of the N-type thermoelectric semiconductor are different from each other.

That is, compared to the existing thin film process, the surface roughness is larger in the screen printing process, and the difference in thickness caused by the large surface roughness may be connected to only a part of some thermoelectric elements as shown in case 1 of FIG. As shown in FIG. 2, the upper or lower substrate is not connected.

This leads to a defect in the junction soon, there is a problem that increases the electrical resistance inside the thermoelectric module (case 1) or short the circuit itself (case 2) and ultimately reduce the thermoelectric conversion efficiency of the module.

DISCLOSURE OF THE INVENTION An object of the present invention is to solve the conventional problems, and includes an electrically conductive layer having excellent electrical conductivity at the ends of the P-type and N-type thermoconductors formed by the screen printing process, thereby increasing the contact area with the substrate. It is to provide a thermoelectric module and a method of manufacturing the same to maximize the conductive area.

Another object of the present invention is to compensate for the difference in height between the P-type and N-type thermoconductors formed by the screen printing process with a coated conductive layer to prevent a short circuit with the upper or lower substrate. And a method for producing the same.

The thermoelectric module according to the present invention includes an upper substrate and a lower substrate which form an upper / lower surface and generate heat or endotherm; And a conductive layer provided on at least one end of each of the P-type and N-type thermal semiconductors spaced apart from each other, and extending the contact area with the upper or lower substrate. It is characterized by.

The conductive layer is characterized by reducing the electrical resistivity between the P-type thermal semiconductor and the N-type thermal semiconductor and the electrode formed by the screen printing process.

The conductive layer is formed of the same material as the electrode.

The conductive layer is characterized in that the P-type thermal semiconductor and the N-type thermal semiconductor is fused to the electrode when sintering.

In the method of manufacturing a thermoelectric module according to the present invention, an electrode forming step of forming an upper electrode or a lower electrode on one side of each of the upper substrate and the lower substrate forming the upper and lower surfaces of the thermoelectric module, and the upper electrode and the lower electrode A semiconductor forming step of forming a P-type thermal semiconductor or an N-type thermal semiconductor on one surface, a metal coating step of forming a conductive layer on at least one end of the P-type thermal semiconductor and the N-type thermal semiconductor, and the conductive layer on an upper electrode And forming a thermoelectric module by bonding to the lower electrode.

Method for manufacturing a thermoelectric module according to the present invention, the electrode forming step of forming an upper electrode or a lower electrode on one side of each of the upper substrate and the lower substrate forming the upper / lower surface of the thermoelectric module, and in the upper electrode or the lower electrode A semiconductor forming step of forming a P-type thermoconductor and an N-type thermoconductor, a metal coating step of forming a conductive layer on one side of the upper electrode or the lower electrode, and the thermoelectric module by bonding the conductive layer to the upper electrode and the lower electrode Characterized in that the module forming step of forming a.

The metal coating step may be a process of forming a conductive layer with an area greater than or equal to the cross-sectional area of the P-type thermal conductor and the N-type thermal conductor.

The semiconductor forming step may be a process of forming a P-type thermal semiconductor and an N-type thermal semiconductor by screen printing a paste in which a nano-sized thermal powder and an organic solvent are mixed.

The module forming step may include a fusion process of fusion of the upper electrode and the lower electrode with the conductive layer, and a sintering process of sintering the P-type heat conductor and the N-type heat conductor.

The fusion process and the sintering process is characterized in that carried out simultaneously.

As described above, in the thermoelectric module according to the present invention, a metal material having excellent electrical conductivity is provided at the ends of the P-type and N-type thermoconductors formed by the screen printing process so as to increase the contact area with the substrate.

Therefore, there is an advantage that the electroconductive area is maximized to improve thermoelectric performance.

In addition, it is possible to prevent the electrical short that may occur in the short circuit between the substrate and the thermoelectric semiconductor, and there is an advantage that can significantly reduce the defective rate.

1 is a schematic diagram showing an internal bonding state of a thermoelectric module manufactured according to the prior art.
Figure 2 is a longitudinal sectional view showing the internal configuration of the thermoelectric module according to the present invention.
3 is an enlarged view of a portion “A” of FIG. 2;
4 is a process flowchart showing a method of manufacturing a thermoelectric module according to the present invention.
5 is a process flowchart showing in detail a step of forming a module in the method of manufacturing a thermoelectric module according to the present invention.
Figure 6 is a longitudinal cross-sectional view showing an internal appearance changed in accordance with an embodiment of the manufacturing method of the thermoelectric module according to the present invention.
7 is a real picture of a sample of a semiconductor forming step is completed in one step in the method of manufacturing a thermoelectric module according to the present invention.
Figure 8 is a SEM photograph of the sample is completed the semiconductor forming step is a step in the method of manufacturing a thermoelectric module according to the present invention.
Figure 9 is a sample comparison photo before / after the metal coating step is a step in the manufacturing method of the thermoelectric module according to the present invention.
10 is a SEM comparison photo before / after the metal coating step of the first step in the manufacturing method of the thermoelectric module according to the present invention.
11 is a graph comparing the electrical resistance according to whether the metal coating step in the method of manufacturing a thermoelectric module according to the present invention.
12 is a longitudinal sectional view showing a metal coating step according to another embodiment in the method of manufacturing a thermoelectric module according to the present invention.
13 is a longitudinal sectional view showing a metal coating step according to another embodiment in the method of manufacturing a thermoelectric module according to the present invention.

Hereinafter, a configuration of a thermoelectric module according to the present invention will be described with reference to FIG. 2.

Figure 2 is a longitudinal sectional view showing the internal configuration of the thermoelectric module according to the present invention.

As shown in the figure, the thermoelectric module 100 according to the present invention is formed on the upper and lower surfaces by the upper substrate 110 and the lower substrate 120. The upper substrate 110 and the lower substrate 120 are formed of a material having thermal conductivity and a certain strength or more as it generates heat or endothermic reaction when power is applied to the thermoelectric module 100.

Electrodes 130 are provided on the lower surface of the upper substrate 110 and the upper surface of the lower substrate 120. The electrode 130 guides the flow of the power when power is applied to the thermoelectric module 100, and the upper electrode 132 and the lower substrate 120 contacting the lower surface of the upper substrate 110. It comprises a lower electrode 134 in contact with the upper surface of the.

The upper electrode 132 and the lower electrode 134 are formed of a material having high electrical conductivity in order to minimize the loss of power supplied to the thermoelectric module 100. More specifically, it is preferable to be formed of a material having excellent conductivity such as silver (Ag) or copper (Cu).

In addition, one surface of the upper electrode 132 and the lower electrode 134 is provided such that the P-type thermoconductor 140 and the N-type thermoconductor 150, which will be described below, are alternately spaced in a left / right direction.

More specifically, the lower surface of the upper electrode 132 is provided with a P-type thermoconductor 140, and the N-type thermoconductor 150 is provided at a position spaced to the right from the P-type thermoconductor 140. do.

An N-type thermoconductor 150 is provided on the left side of the upper surface of the lower electrode 134, and a P-type thermoconductor 140 is provided at a position spaced to the right from the N-type thermoconductor 150.

Accordingly, when power is supplied to the upper substrate 110 and the lower substrate 120, the upper substrate 110 and the lower substrate 120 are connected to each other so that the P-type thermoconductor 140 and the N-type thermoconductor 150 are connected to each other. ) Can be electrically in series.

In more detail, a P-type thermoconductor 140 and an N-type thermoconductor 150 are provided between the upper electrode 132 and the lower electrode 134. The P-type thermoconductor 140 and the N-type thermoconductor 150 are formed by sintering a paste formed by mixing a thermoelectric powder having a thermoelectric characteristic and an organic solvent by a screen printing process.

In other words, the thermoelectric powders constituting the P-type thermoconductor 140 and the N-type thermoconductor 150 are formed into a powder having a size of 150 nm or less by discharging the thermoelectric material with a plasma arc. The processed thermopowder increases the density of the P-type thermoconductor 140 and the N-type thermoconductor 150 to improve the thermoelectric performance.

In addition, the thermoelectric powder is improved by the hydrogen reduction process, and the thermoelectric performance is then mixed with an organic solvent to paste.

The organic solvent is a material that can be completely removed below the firing temperature of the thermoelectric powder used in the manufacturing of the thermoelectric module 100, the thermoelectric powder and the organic solvent was to be 50% -95% of the volume ratio of the powder. This is because if the ratio of the powder is lower than this, many pores are left inside after sintering, and if the ratio is too high, the flow of the paste becomes bad and printing is not easy.

On the other hand, one end of the P-type thermal semiconductor 140 and the N-type thermal semiconductor 150 is provided with a conductive layer 160, which is a main component of the present invention.

The conductive layer 160 is disposed between the N-type thermoconductor 150 and the P-type thermoconductor 140 and the upper electrode 132 and the lower electrode 134 to solve the bonding failure, and the thermoelectric module 100 In order to reduce the electrical resistivity, it is possible to maximize the electrical conductivity area by coating a metal material with excellent electrical conductivity.

In the embodiment of the present invention, gold (Au), which is the same material as that of the upper electrode 132 and the lower electrode 134, was adopted.

The role of the conductive layer 160 will be described in more detail with reference to FIG. 3.

FIG. 3 is an enlarged view of a portion “A” of FIG. 2. Referring to the P-type thermoconductor 140 as an example, the P-type thermoconductor 140 may be formed by growing upward from the bottom by a screen printing process. At this time, the surface roughness is increased in the upper end portion is formed uneven (142).

The unevenness 142 does not come into contact with the upper electrode 132, or even in contact with only a part of the unevenness 142, thereby reducing the thermoelectric conversion efficiency of the thermoelectric module 100.

Therefore, the conductive layer 160 is formed of a metal having excellent electrical conductivity through a screen printing process on the upper end of the P-type thermal conductor 140 to thereby expand the contact area between the P-type thermal conductor 140 and the upper electrode 132. The electrical resistance can be lowered and the thermoelectric conversion efficiency can be increased.

The conductive layer 160 is fused and bonded to the upper electrode 132 and the lower electrode 134 at the time of sintering the P-type thermoconductor 140 and the N-type thermoconductor 150.

Hereinafter, a method of manufacturing a thermoelectric module configured as described above will be described with reference to FIGS. 4 and 5.

4 is a process flow chart showing a method of manufacturing a thermoelectric module according to the present invention, Figure 5 is a process flow chart showing in detail a step of forming a module in the method of manufacturing a thermoelectric module according to the present invention.

As shown in these figures, the thermoelectric module 100 forms an upper electrode 132 or a lower electrode 134 on one side of each of the upper substrate 110 and the lower substrate 120 forming upper and lower surfaces. Step (S100), the semiconductor forming step (S200) to form a P-type thermal semiconductor 140 or N-type thermal semiconductor 150 on any one surface of the upper electrode 132 and the lower electrode 134, and the P A metal coating step (S300) of forming a conductive layer 160 on at least one end of the type thermal semiconductor 140 and the N type thermal semiconductor 150, and the upper layer 132 and the lower electrode (the conductive layer 160) The module forming step (S400) of forming a thermoelectric module 100 by bonding to 134.

The electrode forming step (S100) is a metal mask (not shown) or metal mesh (not shown) prepared in advance on one surface of the upper substrate 110 and the lower substrate 120, and then ball mill processing The process of forming the electrode 130 by passing the metal powder, such as silver or copper, through a metal mask or a metal mesh.

That is, fine holes are formed in the metal mask or the metal mesh at the position where the electrode 130 is to be formed, and metal powder such as silver or copper passes through the fine holes. By doing so, the upper electrode 132 or the lower electrode 134 is screen printed on one surface of the upper substrate 110 or the lower substrate 120.

Therefore, the metal powders such as gold, silver, and copper should be applied in a paste state mixed with an organic solvent so that the metal powders such as gold, silver, and copper can remain attached without being separated from the upper substrate 110 or the lower substrate 120 after screen printing. It is preferable to.

In addition, the upper electrode 132 or the lower electrode 134 on which the electrode forming step S100 is completed is spaced at equal intervals.

Subsequently, a semiconductor forming step (S200) of forming a P-type thermoconductor 140 and an N-type thermoconductor 150 on the lower surface of the upper electrode 132 or the upper surface of the lower electrode 134 is performed.

That is, the semiconductor forming step (S200) is a process of forming the P-type thermal semiconductor 140 and the N-type thermal semiconductor 150 on the upper electrode 132 and the lower electrode 134, in the embodiment of the present invention attached As shown in FIG. 6, an N-type thermoconductor 150 is formed on a lower surface of the upper electrode 132, and a P-type thermoconductor 140 is formed on an upper surface of the lower electrode 134. 150 and the P-type thermoconductor 140 are preferably configured to be equally spaced apart so that the extension lines do not cross each other.

The semiconductor forming step S200 is performed by screen printing similarly to the electrode forming step S100.

More specifically, a metal mask or a metal mesh prepared in advance for forming the electrode 130 on the upper electrode 132 or the upper surface of the lower electrode 134 is seated, and the metal mask or The paste is passed through a metal mesh to form a P-type thermoconductor 140 or an N-type thermoconductor 150.

Therefore, in the metal mask or the metal mesh used in the semiconductor forming step S200, minute holes are formed in the positions where the P-type thermal semiconductors 140 and the N-type thermal semiconductors 150 are formed. It must be formed.

When the semiconductor forming step S200 is completed, the semiconductor forming step S200 is completed, and the metal coating step S300 is performed.

The metal coating step (S300) is formed on at least one end of each of the P-type thermoconductor 140 and the N-type thermoconductor 150 to expand the contact area with the upper substrate 110 or the lower substrate 120. It is a process of forming the conductive layer 160.

Therefore, the conductive layer 160 is preferably formed with an area greater than or equal to the cross-sectional area of the ends of the P-type thermoconductor 140 and the N-type thermoconductor 150.

After the metal coating step (S300), a module forming step (S400) is performed. In the module forming step (S400), the upper substrate 110 and the lower substrate 120 on which the conductive layer 160 is formed are close to each other, as shown in the center of FIG. 6, and then charged into a mold (not shown) prepared in advance to be heated and By pressing, the thermoelectric module 100 is formed.

In this case, the conductive layer 160 is fused and bonded to the opposite electrode 130, and the P-type thermal semiconductor 140 and the N-type thermal semiconductor 150 in a paste state are sintered.

In more detail, the module forming step (S400), the module forming step, the fusion process (S420) for fusion bonding the upper electrode 132 and the lower electrode 134 with the conductive layer 160, and the P-type It consists of a sintering process (S440) for sintering the thermoelectric semiconductor 140 and the N-type thermoelectric semiconductor 150, the fusion process (S420) and the sintering process (S440) is carried out at the same time.

The sintering process (S440) is a process of debinding for 1-3 hours in a non-oxidizing atmosphere at a temperature of 250 ° C. or lower to remove the organic solvent mixed with the thermal starch powder, and sintering the thermal starch powder. It is possible to manufacture the thermoelectric module 100 in the same state.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 7 to 11.

FIG. 7 is a real picture of a sample in which a semiconductor formation step is completed in a method of manufacturing a thermoelectric module according to the present invention, and a P-type thermoconductor 140 is formed on an upper surface of a lower electrode 134 using a screen printing process. The N-type thermoconductor 150 is formed on the upper electrode 132.

That is, as shown in FIG. 8, a lower electrode 134 is provided on the upper surface of the lower substrate 120, and a P-type thermoconductor 140 is formed on the upper surface of the lower electrode 134.

After the metal coating step (S300) was carried out to produce a sample as shown in FIG.

9 and 10 are sample comparison photographs and SEM comparison photographs before and after the metal coating step of the first step in the method of manufacturing a thermoelectric module according to the present invention, the P-type thermoconductor 140 and the N-type thermoconductor 150 It can be seen that the conductive layer 160 is formed on the upper surface.

As a result of measuring the electrical resistance of the thermoelectric module 100 according to the preferred embodiment of the present invention manufactured according to the above process and the comparative example without performing the metal coating step, as shown in FIG. Able to know.

On the other hand, the thermoelectric module 100 can be implemented in another embodiment as shown in FIG.

12 is a longitudinal cross-sectional view illustrating a metal coating step according to another embodiment in a method of manufacturing a thermoelectric module according to the present invention, in which a detailed description of the same process will be omitted when comparing with an embodiment, and there is a difference in semiconductors. The forming step (S200), the metal coating step (S300) and the module forming step (S400) will be described.

In another embodiment of the semiconductor forming step (S200), the P-type thermoconductor 140 and the N-type thermoconductor 150 are spaced apart from each other on the upper surface of the lower substrate 120 on which the lower electrode 134 is formed. The semiconductor 150 and the P-type thermal semiconductor 140 are screen printed using a metal mask or a metal mesh prepared in advance.

That is, the metal mask or the metal mesh is provided with a pair for forming the N-type thermoconductor 150 and a pair for forming the P-type thermoconductor 140. The metal mask or the metal mesh is formed so that the micro holes do not coincide with each other.

In more detail, the fine holes formed in the pair of metal masks are for forming only one of the P-type thermal semiconductor 140 and the N-type thermal semiconductor 150 on one surface of the electrode 130, and thus, a pair of metal masks. When overlapping each other, the micropores formed in each do not communicate with each other.

Accordingly, the P-type thermoconductor 140 and the N-type thermoconductor 150 formed by screen printing using the metal mask or the metal mesh are parallel to each other in the same electrode 130 as shown in the lower section of FIG. 12. It is located on the vertical line, and is kept spaced apart.

Thereafter, the conductive layer 160 is formed on the upper ends of the N-type thermoconductor 150 and the P-type thermoconductor 140 (metal coating step (S300)), and then placed in a mold (not shown), and then heated and pressurized. By sintering to complete the module forming step (S400).

On the other hand, in another embodiment it can be implemented as shown in FIG.

FIG. 13 is a longitudinal cross-sectional view illustrating a metal coating step according to another embodiment in the method of manufacturing a thermoelectric module according to the present invention. The lower substrate 120 having the lower electrode 134 formed in the semiconductor forming step S200 as shown in FIG. 12. The P-type thermoconductor 140 and the N-type thermoconductor 150 are formed to be spaced apart from each other, but the conductive layer 160 is formed on the lower surface of the upper electrode 132.

When the module forming step is performed in this state, the upper electrode 132 may be fused with the upper ends of the N-type thermoconductor 150 and the P-type thermoconductor 140 to form the thermoelectric module 100. .

The scope of the present invention is not limited to the above-exemplified embodiments, and many modifications based on the present invention will be possible to those skilled in the art within the above technical scope.

100. Thermoelectric Module 110. Upper Board
120. Lower substrate 130. Electrode
132. Upper electrode 134. Lower electrode
140.P type thermoconductor 142.Unevenness
150. N-type thermoconductor S100. Electrode Formation Step
S200. Semiconductor Formation Step S300. Metal coating step
S400. Module formation step S420. Fusion process
S440. Sintering Process

Claims (10)

An upper substrate and a lower substrate which form an upper / lower surface and generate heat or endotherm;
It is formed by coating a paste containing a metal powder containing at least one of gold (Au), silver (Ag), copper (Cu) on the one surface of the upper substrate and the lower substrate by a screen printing method, An electrode including an upper electrode and a lower electrode for guiding the flow of power;
A plurality of P-type thermal semiconductors and N-type thermal semiconductors spaced apart from each other by coating a paste formed by mixing a thermal powder and an organic solvent on one side of at least one surface of the upper electrode and the lower electrode by a screen printing method;
At least one of the P-type thermal semiconductor and the N-type thermal semiconductor is coated by the screen printing method with the same material as the electrode, and the P-type thermal semiconductor and the N-type thermal semiconductor at the time of sintering the P-type thermal semiconductor and the N-type thermal semiconductor A thermoelectric module comprising a conductive layer extending the contact area by fusion with the thermoelectric semiconductor and the electrode. The method of claim 1, wherein the conductive layer,
A thermoelectric module, characterized in that to reduce the electrical resistivity between the P-type thermoconductor and N-type thermoconductor and the electrode. delete delete An electrode forming step of forming an upper electrode or a lower electrode on at least one side of an upper substrate and a lower substrate forming upper and lower surfaces of the thermoelectric module;
Forming a semiconductor to form at least one of a P-type thermal semiconductor and an N-type thermal semiconductor by screen printing a paste mixed with a nano-sized thermal powder and an organic solvent on one side of at least one of the upper electrode and the lower electrode Steps;
Forming a conductive layer by coating a paste including the same material as the electrode on one or more of the P-type and N-type thermal conductor, and at least one of the upper electrode and the lower electrode by the screen printing method A metal coating step;
And a module forming step consisting of a fusion process of fusion of the upper electrode and the lower electrode with a conductive layer, and a sintering process of sintering the P-type heat conductor and the N-type heat conductor.
The module forming step,
The process of completing the thermoelectric module by removing the unevenness formed at the upper end of the P-type thermal conductor and the N-type thermal semiconductor by fusion and removal with the P-type thermoconductor, the N-type thermoconductor and the electrode by simultaneously performing the fusion process and the sintering process. Method of manufacturing a thermoelectric module characterized in that. The method of claim 5, wherein the sintering process,
Method for producing a thermoelectric module, characterized in that carried out in the temperature range of 250 ℃ or less in the non-oxidation component crisis. The method of manufacturing a thermoelectric module according to claim 6, wherein the metal coating step is a process of forming a conductive layer with an area greater than or equal to a cross-sectional area of an end portion of the P-type thermoconductor and the N-type thermoconductor. The method of claim 7, wherein the module forming step,
And a step of compensating for the difference in height between the P-type thermoconductor and the N-type thermoconductor generated in the semiconductor forming step with a conductive layer. delete delete

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