KR102510123B1 - Thermoelectric element - Google Patents

Abstract

A thermoelectric element according to the present invention includes a first substrate; a first electrode disposed on the first substrate; a plurality of semiconductor elements disposed on the first electrode; a second electrode disposed on the semiconductor element; and a second substrate disposed on the second electrode, including a terminal electrode disposed between the semiconductor element and the second substrate and extending to a side surface of the second substrate.

Description

Thermoelectric element {THERMOELECTRIC ELEMENT}

The present invention relates to a thermoelectric device, and more particularly, to a thermoelectric device capable of improving thermoelectric efficiency.

In general, a thermoelectric element including a thermoelectric conversion element has a structure in which a PN junction pair is formed by bonding a P-type thermoelectric material and an N-type thermoelectric material between metal electrodes. When a temperature difference is provided between the PN junction pair, power is generated by a Seebeck effect, so that the thermoelectric element can function as a power generation device. In addition, the thermoelectric element may be used as a temperature control device due to a Peltier effect in which one side of the PN junction pair is cooled and the other side is heated.

Here, the Peltier effect is caused by the movement of holes of p-type material and electrons of n-type material when a DC voltage is applied from the outside, causing heat generation and absorption of heat at both ends of the material am. The Seebeck effect refers to a phenomenon in which an electric current flows through a material while electrons and holes move when heat is supplied from an external heat source, causing power generation.

These thermoelectric elements enable precise and rapid temperature control and cooling/heating switching with simple manipulation, and are applied to high-precision coolers/thermostats, optical component elements, optical sensors, and precision electronic products. In addition, since the thermoelectric module can simultaneously realize cooling and heating in one module by changing the polarity of DC power, it can be effectively used in an air handling unit or the like. In addition, for example, it can be used as a cooling/constant temperature device such as a small refrigerator, a cosmetic refrigerator, a wine refrigerator, a hot and cold water purifier, a cooling seat for a vehicle, a semiconductor facility, and a precision thermostat.

A terminal wire is connected to the electrode layer of the thermoelectric element by bonding.

However, as the thermoelectric element is miniaturized, defects due to terminal wire connection are likely to occur.

In order to solve the defect problem, a method of forming a wide terminal pad portion on a board instead of a terminal wire and connecting it to an external circuit by soldering is sometimes used. However, in this case, since the external substrate must be formed widely, the total area of the device is widened and the area-to-area performance is lowered.

In addition, in order to solve this problem, a method of connecting wire bonding from an external power source by erecting a post (metal pillar) instead of a terminal wire is sometimes used.

However, even in this case, since the lower substrate has to be formed wider than the upper substrate, there is a problem in that performance versus area is lowered.

The problem to be solved by the present invention is to provide a thermoelectric element capable of preventing terminal wire bonding failure even if it is miniaturized.

An object to be solved by the present invention is to provide a thermoelectric element capable of improving efficiency.

A thermoelectric element according to an embodiment of the present invention includes a first substrate; a first electrode disposed on the first substrate; a plurality of semiconductor elements disposed on the first electrode; a second electrode disposed on the semiconductor element; a second substrate disposed on the second electrode; and a terminal electrode disposed between the semiconductor element and the second substrate and extending to a side surface of the second substrate.

Also, in the thermoelectric element according to an embodiment of the present invention, the terminal electrode may extend from an electrode disposed on one surface of an outermost semiconductor element among the semiconductor elements.

Also, in the thermoelectric element according to an embodiment of the present invention, the terminal electrode may have an “L” shape.

Also, in the thermoelectric device according to an embodiment of the present invention, the terminal electrode may include the same material as at least one of the first electrode and the second electrode.

Also, in the thermoelectric element according to an embodiment of the present invention, the terminal electrode may extend to an upper surface of the second substrate.

Also, in the thermoelectric element according to an embodiment of the present invention, the terminal electrode may have a “c” shape.

In addition, in the thermoelectric element according to an embodiment of the present invention, the terminal electrode includes a first terminal electrode disposed on one outermost side of the second substrate and a second terminal electrode disposed on the other outermost side of the second substrate. can include

According to an embodiment of the present invention, the terminal electrode can be easily formed even when the thermoelectric element is miniaturized.

In addition, according to an embodiment of the present invention, at least two more semiconductor elements can be mounted on the wire, so that the efficiency of the thermoelectric element can be improved. It can improve performance by about 3%.

In addition, according to an embodiment of the present invention, since the upper substrate is increased by the area of the lower substrate and semiconductor devices can be mounted in one row or more, cooling performance and efficiency compared to the area of the device can be improved.

1 is a cross-sectional view of a thermoelectric element according to an embodiment of the present invention.
2 is a plan view of a thermoelectric element according to an embodiment of the present invention.
3 is a perspective view of a thermoelectric element according to an embodiment of the present invention.
4 is a cross-sectional view of a thermoelectric element according to another embodiment of the present invention.
5 shows that a terminal wire bonding defect occurs in a conventional thermoelectric element.
6 is a perspective view of a conventional thermoelectric element.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

Terms including ordinal numbers, such as first and second, may be used to describe various components, but the components are not limited by the terms.

These terms are only used for the purpose of distinguishing one component from another. For example, a second element may be termed a first element, and similarly, a first element may be termed a second element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, but the same or corresponding components regardless of reference numerals are given the same reference numerals, and overlapping descriptions thereof will be omitted.

1 is a cross-sectional view of a thermoelectric element according to an embodiment of the present invention, and FIG. 2 is a plan view of a thermoelectric element according to an embodiment of the present invention. 3 is a perspective view of a thermoelectric element according to an embodiment of the present invention.

1 to 3, a thermoelectric device according to an embodiment of the present invention includes a first substrate 10, a first electrode 20, a semiconductor device 30, and a second electrode 40 and a second electrode 40. It may include 2 substrates 50 .

The first substrate 10 and the second substrate 50 may face each other and be spaced apart from each other.

The first substrate 10 and the second substrate 50 may serve to support the semiconductor element 30 , the first electrode 20 and the second electrode 40 . Moreover, when a plurality of semiconductor elements 30 are provided, the first substrate 10 and the second substrate 50 may serve to connect the plurality of semiconductor elements 30 to each other.

In addition, the first substrate 10 and the second substrate 50 may serve to absorb heat from the outside or dissipate heat to the outside through heat exchange of the semiconductor device 30 by being bonded to an external device. That is, the first substrate 10 and the second substrate 50 may serve to transfer heat between an external device and the semiconductor element 30 . Accordingly, the efficiency of the thermoelectric element may be affected by the thermal conductivity of the substrates 10 and 50 . The substrates 10 and 50 may be made of ceramics having high thermal conductivity.

The substrates 10 and 50 may be made of a metal having excellent thermal conductivity. For example, the substrates 10 and 50 may be made of aluminum and copper. It is possible to implement heat absorbing and exothermic efficiency and thinning by using a metal substrate. Of course, when the first substrate 10 and the second substrate 50 are formed of metal substrates, the dielectric layer between the electrode layers 20 and 40 formed on the first substrate 10 and the second substrate 50 (Not shown) is preferably formed by further including. The dielectric layer may be made of a material having durability capable of withstanding a process of forming a thermoelectric element. For example, the dielectric layer may be formed of any one of Si2, Al2O3, TiO2, Zno, NiO, and Y2O3.

In the case of the metal substrate, Cu or Cu alloy can be applied, and the thickness that can be thinned can be formed in the range of 0.1 mm to 0.5 mm. When the thickness of the metal substrate is less than 0.1 mm, or when the thickness exceeds 0.5 mm, heat dissipation characteristics are too high or thermal conductivity is too high, so the reliability of the thermoelectric module is greatly reduced. In the case of the dielectric layer, as a dielectric material having high heat dissipation performance, considering the thermal conductivity of the thermoelectric module for cooling, a material having a thermal conductivity of 5 to 10 W/K is used, and the thickness may be formed in the range of 0.01 mm to 0.15 mm. there is. In this case, when the thickness is less than 0.01 mm, insulation efficiency (or withstand voltage characteristics) is greatly reduced, and when the thickness exceeds 0.15 mm, thermal conductivity is lowered and heat dissipation efficiency is lowered.

A first electrode 20 and a second electrode 40 may be disposed on inner surfaces of the first substrate 10 and the second substrate 50 .

That is, the first electrode 20 may be disposed above the first substrate 10 , and the second electrode 40 may be disposed below the second substrate 50 .

The first electrode 20 and the second electrode 40 electrically connect the semiconductor element 30 using an electrode material such as Cu, Ag, Ni, and the like, and when a plurality of unit cells are connected, FIG. 3 As shown in , an electrical connection is formed with an adjacent unit cell. The thickness of the first electrode and the second electrode may be formed in a range of 0.01 mm to 0.3 mm. If the thickness of the electrode layer is less than 0.01 mm, the function as an electrode deteriorates and the electrical conductivity is poor, and even if the thickness exceeds 0.3 mm, the conduction efficiency is lowered due to the increase in resistance.

The first electrode 20 and the second electrode 40 are arranged in a zigzag pattern so that the first semiconductor element 31 and the second semiconductor element 32 can be connected in series.

At this time, any one of the first electrode 20 and the second electrode 40 may be extended and disposed to the outer surface of the substrate. In this embodiment, the case where the second electrode 40 is extended is illustrated.

As shown, a plurality of semiconductor elements 30 may be disposed between the substrates 10 and 50, and the plurality of semiconductor elements have a first semiconductor element 31 and a second semiconductor element 32 forming a pair. An electrode may be disposed above or below the semiconductor element.

That is, as shown in FIG. 3, a plurality of electrodes are separated and disposed.

In this case, the terminal electrode 41 disposed on the outermost semiconductor element among the plurality of second electrodes 40 may be included. The terminal electrode 41 may be disposed on an uppermost semiconductor element among a plurality of semiconductor elements. And as shown, two terminal electrodes 41 may be disposed on one side and the outermost outermost side of the other side of the substrate.

The terminal electrode 41 may have a “c” shape. The electrodes disposed under the second substrate 50 may extend to the upper portion of the second substrate 50 . That is, it may extend along the surface of the second substrate 50 .

Also, the terminal electrode 41 may have a "B" shape.

4 shows a case in which the terminal electrode 41 has a “B” shape as another embodiment of the present invention.

Referring to FIG. 4 , it can be seen that the terminal electrode 41 disposed under the second substrate 50 extends to the side of the second substrate 50 . That is, it may extend to the surface of the second substrate 50 .

When the terminal electrode 41 is extended to the top of the substrate and disposed, as shown in FIG. 5, it is possible to mount a thermoelectric material (semiconductor element) in one row at the location of the terminal electrode disposed on the existing thermoelectric element, resulting in greater thermoelectric performance. It is possible to implement a thermoelectric element that generates.

A semiconductor device 30 may be disposed between the electrode layers 20 and 40 and the semiconductor devices may be joined by solder.

The semiconductor element 30 may be composed of a P-type semiconductor as the first semiconductor element 31 and an N-type semiconductor as the second semiconductor element 32, and the first semiconductor element 31 and the second semiconductor element 32 is connected to the first electrode 20 and the second electrode 40, and a plurality of such structures are formed, and the Peltier effect is achieved by the circuit lines L1 and L2 through which current is supplied to the semiconductor element through the electrode. will implement

In addition, a P-type semiconductor or N-type semiconductor material may be applied to the semiconductor element 40 in the thermoelectric element. The P-type semiconductor or N-type semiconductor material includes selenium (Se), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B ), gallium (Ga), tellurium (Te), bismuth (Bi), and indium (In), and 0.001 to 1.0 wt% of the total weight of the main raw material composed of bismuth telluride (BiTe) It can be formed using a mixture in which Bi or Te corresponding to is mixed. 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 100 g, it is preferable to add Bi or Te to be additionally mixed in the range of 0.001 g to 1.0 g. As described above, the weight range of the material added to the above-mentioned main raw material is significant in that the thermal conductivity does not decrease and the electrical conductivity decreases outside the range of 0.001wt% to 0.1wt%, 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 ( A mixture of a main raw material composed of bismuth telluride (BiTe) including Te), bismuth (Bi), and indium (In), and 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 may be 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, Bi or Te to be additionally mixed 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 meaningful in that, outside the range of 0.001wt% to 0.1wt%, the thermal conductivity does not decrease and the electrical conductivity decreases, so that an improvement in the ZT value cannot be expected.

The shape and size of the first semiconductor element 31 and the second semiconductor element 32 facing each other forming a unit cell are made the same, but in this case, the electrical conductivity of the P-type semiconductor element and the electrical conductivity of the N-type semiconductor element In consideration of the fact that they are different from each other and act as an element that impairs cooling efficiency, it is also possible to improve cooling performance by forming the volume of one side differently from the volume of the other semiconductor element facing each other.

That is, forming different volumes of semiconductor elements of unit cells disposed facing each other is to form the overall shape differently, to form a wide diameter of either cross section in semiconductor elements having the same height, or to form the same shape In a semiconductor device, it is possible to implement a method in which a height or a diameter of a cross section is different. In particular, the diameter of the N-type semiconductor device is formed to be larger than that of the P-type semiconductor device to increase the volume, thereby improving thermoelectric efficiency.

5 shows a defect due to a terminal wire in a conventional thermoelectric element.

Referring to A, it can be confirmed that the terminal wire is connected to the leg (semiconductor element) and a defect has occurred.

In particular, recently, as thermoelectric elements have been miniaturized, such defects are likely to occur. For example, in the case of a laser module for optical communication, a thermoelectric element is disposed in the central area of the laser module, but it is not easy to connect terminal electrodes because the element is small. In order to wire bond up to the terminal electrode, it is not easy to wire bond because various parts are mounted. To this end, posts have been conventionally formed, but when the posts are formed, the area of the upper substrate is narrowed, and as a result, the number of semiconductor elements that can be mounted is reduced.

However, this problem can be solved by extending the electrode to the top of the substrate as in the present invention.

Embodiments according to the present invention have been described above, but these are merely examples, and those skilled in the art will understand that various modifications and embodiments of equivalent range are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined by the following claims.

10: first substrate
20: first electrode
30: semiconductor element
40: second electrode
50: second substrate

Claims (7)

a first substrate;
a first electrode disposed on the first substrate;
a plurality of semiconductor elements disposed on the first electrode;
a second electrode disposed on the semiconductor element;
a second substrate disposed on the second electrode; and
A thermoelectric element comprising: a terminal electrode disposed between the semiconductor element and the second substrate, covering a side surface of the second substrate, and extending to an upper surface of the second substrate.
According to claim 1,
The terminal electrode is a thermoelectric element in which an electrode disposed on one surface of an outermost semiconductor element among the semiconductor elements is extended.
The thermoelectric element according to claim 1, wherein the terminal electrode has a "B" shape.
The thermoelectric device of claim 1 , wherein the terminal electrode includes the same material as at least one of the first electrode and the second electrode.
The thermoelectric element of claim 3 , wherein the terminal electrode extends to an upper surface of the second substrate.
The thermoelectric element according to claim 5, wherein the terminal electrode has a "c" shape.
The thermoelectric element of claim 1 , wherein the terminal electrode includes a first terminal electrode disposed on one side of an outermost side of the second substrate and a second terminal electrode disposed on an outermost side of the second substrate.

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