KR102581613B1 - Thermoelectric element - Google Patents

Abstract

A thermoelectric element according to an embodiment of the present invention includes a first substrate; a first electrode layer disposed on a first substrate; a plurality of semiconductor devices disposed on the first electrode layer; a second electrode layer disposed on the plurality of semiconductor devices; a second substrate disposed on the second electrode layer; and a first heat exchange layer disposed in a partial region of the first substrate, wherein the first substrate includes a central region and an edge region, and the first heat exchange layer may be disposed in the edge region.

Description

Thermoelectric element {THERMOELECTRIC ELEMENT}

The present invention relates to thermoelectric devices, and more specifically, to high-reliability thermoelectric devices that can improve reliability.

Generally, a thermoelectric element including a thermoelectric conversion element has a structure that forms a PN junction pair by bonding a P-type thermoelectric material and an N-type thermoelectric material between metal electrode layers. When a temperature difference is provided between these PN junction pairs, the thermoelectric element can function as a power generation device by generating power through the Seeback effect. Additionally, a thermoelectric element can also be used as a temperature control device due to the Peltier effect, in which one side of a PN junction pair is cooled and the other side is heated.

Here, the Peltier effect is a phenomenon in which holes in a p-type material and electrons in an n-type material move when a DC voltage is applied from the outside, causing heat generation and endothermy at both ends of the material. am. The Seeback effect refers to a phenomenon in which electrons and holes move when heat is supplied from an external heat source, causing a flow of current in the material, thereby generating electricity.

These thermoelectric elements enable precise and rapid temperature control and cooling/heating switching with simple operation, and are applied to high-precision coolers/humidifiers, optical components, optical sensors, and precision electronic products. In addition, thermoelectric modules can simultaneously implement cooling and heating in one module by changing the polarity of direct current power, so they can be effectively used in air handling units, etc. In addition, it can be used as a cooling/constant temperature device for, for example, small refrigerators, cosmetic refrigerators, wine refrigerators, hot and cold water purifiers, car cooling seats, semiconductor equipment, and precision constant temperature baths.

In general, due to the temperature difference between the upper and lower parts of a thermoelectric element, the high-temperature part of the substrate expands and the low-temperature part contracts, and the repeated simultaneous expansion and contraction of the upper and lower parts increases stress on the semiconductor device.

Additionally, this phenomenon occurs as the size of the substrate increases, the degree of expansion and contraction increases, and the resulting stress also increases.

There is a problem in that semiconductor devices are damaged and fail due to such repeated contraction and expansion.

The problem to be solved by the present invention is to provide a thermoelectric device that can prevent failure by reducing the stress applied to the semiconductor device.

A thermoelectric element according to an embodiment of the present invention includes a first substrate; a first electrode layer disposed on a first substrate; a plurality of semiconductor devices disposed on the first electrode layer; a second electrode layer disposed on the plurality of semiconductor devices; a second substrate disposed on the second electrode layer; and a first heat exchange layer disposed in a partial region of the first substrate, wherein the first substrate includes a central region and an edge region, and the first heat exchange layer may be disposed in the edge region.

Additionally, the thermoelectric element according to an embodiment of the present invention further includes a second heat exchange layer disposed in a partial area of the second substrate, wherein the second substrate includes a central area and an edge area, and the second heat exchange layer includes a central area and a border area. The heat exchange layer may be disposed in an edge area of the second substrate.

Additionally, in the thermoelectric element according to an embodiment of the present invention, one surface of the first substrate and one surface of the first heat exchange layer may be disposed on the same plane.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the first heat exchange layer may be formed in a pattern.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the pattern may have a circular shape or an elongated shape.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the edge of the first heat exchange layer may be disposed at a position 60% of the distance between the edge of the first substrate and the edge of the first electrode layer.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the first heat exchange layer may be disposed in a corner area of the first substrate.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the first heat exchange layer may be disposed in an area where a terminal wire connected to the first electrode layer is disposed.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the first heat exchange layer may be circular, and the diameter of the circular shape may be 5% to 20% of the width of the first substrate.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the first heat exchange layer may be disposed at an edge area of the substrate and may be disposed to become narrower toward the center from the terminal wire connected to the electrode layer.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the first heat exchange layer may have a width in one direction of 5% to 10% of the width of the first substrate, and may have a width of 5% to 20% in the other direction. there is.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the thickness of the first heat exchange layer may be 1/3 to 1/2 of the thickness of the first substrate.

Additionally, in the thermoelectric element according to an embodiment of the present invention, the first heat exchange layer may be composed of any one of metal, ceramic, diamond, metal composite, ceramic-metal composite, and diamond-metal composite.

According to an embodiment of the present invention, temperature exchange can be facilitated at the substrate contact portion of the thermoelectric element, thereby suppressing deformation of the substrate due to heat accumulation.

Additionally, according to an embodiment of the present invention, damage to the semiconductor device can be prevented by reducing the stress applied to the semiconductor device disposed between the substrates.

Figure 1 shows a cross-sectional view of a thermoelectric element according to an embodiment of the present invention.
Figure 2 shows a perspective view of a thermoelectric element according to an embodiment of the present invention.
Figure 3 shows a plan perspective view of a thermoelectric element according to an embodiment of the present invention.
Figure 4 shows an example of the heat exchange layer arrangement of a thermoelectric element according to another embodiment of the present invention.
Figure 5 shows an example in which a thermoelectric element is damaged.

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 changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

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

The above terms are used only for the purpose of distinguishing one component from another. For example, the second component may be named the first component without departing from the scope of the present invention, and similarly, the first component may also be named the second component. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

Hereinafter, embodiments will be described in detail with reference to the attached drawings, but identical or corresponding components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted.

Figure 1 shows a cross-sectional view of a thermoelectric element according to an embodiment of the present invention, and Figure 2 shows a perspective view of a thermoelectric element according to an embodiment of the present invention.

Referring to Figures 1 and 2, the thermoelectric element according to an embodiment of the present invention includes a first substrate 10, a first electrode layer 20, a semiconductor element 30, a second electrode layer 40, and a second substrate. (50), a first heat exchange layer 60, and a second heat exchange layer 70.

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

The first electrode layer 20 may be disposed on the top of the first substrate 10, and the second electrode layer 40 may be disposed on the bottom of the second substrate 50. That is, the first electrode layer 20 and the second electrode layer 40 may be disposed inside the substrates 10 and 50.

The semiconductor device 30 may be disposed between the first electrode layer 20 and the second electrode layer 40.

Solder may be disposed between the semiconductor element 30 and the electrode layer. Solder joins the substrates 20 and 40 of the semiconductor device 30. The solder may include a first solder for bonding the first substrate 10 and the semiconductor device 30 and a second solder for bonding the second substrate 50 and the semiconductor device 30. The solder material may be a material used in conventional soldering, such as silver paste, PbSn, CuAgSn, or Sn, and may be formed through a printing process.

The first semiconductor element 31 and the second semiconductor element 32 are electrically connected between the first substrate 10 and the second substrate 50 to implement the Peltier effect.

The first substrate 10 and the second substrate 50 may use an insulating substrate, such as an alumina substrate, or in another embodiment, a metal substrate may be used to achieve heat absorption and heat generation efficiency and thinning. there is. Of course, when the first substrate 10 and the second substrate 50 are formed of a metal substrate, a dielectric layer is formed between the electrode layers 20 and 40 formed on the first substrate 10 and the second substrate 50. It is preferable to further include (not shown).

In the case of a metal substrate, Cu or Cu alloy can be applied, and the thickness that can be thinned is in the range of 0.1mm to 0.5mm. When the thickness of the metal substrate is thinner than 0.1 mm or exceeds 0.5 mm, the heat dissipation characteristics are too high or the thermal conductivity is too high, greatly reducing the reliability of the thermoelectric module. In the case of the dielectric layer, a dielectric material with high heat dissipation performance is used, and considering the thermal conductivity of the cooling thermoelectric module, a material with a thermal conductivity of 5 to 10 W/K is used, and the thickness can be formed in the range of 0.01 mm to 0.15 mm. there is. In this case, if the thickness is less than 0.01mm, the insulation efficiency (or withstand voltage characteristic) is greatly reduced, and if the thickness is more than 0.15mm, the thermal conductivity is lowered and the heat dissipation efficiency is reduced. The electrode layers 20 and 40 electrically connect the first semiconductor device and the second semiconductor device using electrode layer materials such as Cu, Ag, and Ni, and when multiple unit cells are connected, as shown in FIG. 2 As such, an electrical connection is formed with adjacent unit cells. The thickness of the electrode layer may be in the range of 0.01mm to 0.3mm. If the thickness of the electrode layer is less than 0.01 mm, it does not function as an electrode layer and has poor electrical conductivity, and even if it exceeds 0.3 mm, the conduction efficiency decreases due to an increase in resistance.

In particular, in this case, the thermoelectric element forming the unit cell can be a thermoelectric element including a unit element with a stacked structure according to an embodiment of the present invention, and in this case, one side is the first semiconductor element 31 and includes a P-type semiconductor and The second semiconductor element 32 may be composed of an N-type semiconductor, and the first semiconductor element 31 and the second semiconductor element 32 are connected to the first electrode layer 20 and the second electrode layer 40. A number of such structures are formed, and the Peltier effect is realized by circuit lines (L1, L2) through which current is supplied to the semiconductor device through the electrode layer.

In addition, the semiconductor element 30 in the thermoelectric element may be made of a P-type semiconductor or N-type semiconductor material. These P-type semiconductor or N-type semiconductor materials include selenium (Se), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), and boron (B). ), a main raw material consisting of bismuth telluride-based (BiTe-based) including 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. It can be formed using a mixture of Bi or Te corresponding to. For example, the main raw material is Bi-Se-Te material, and Bi or Te can be added to form a weight equivalent to 00.001 to 1.0 wt% of the total weight of Bi-Se-Te. That is, Bi When 100 g of -Se-Te is added, it is preferable to add Bi or Te to be additionally mixed in the range of 0.001 g to 1.0 g. As mentioned above, the weight range of the material added to the above-mentioned main raw material is significant in that outside the range of 0.001wt% to 0.1wt%, the thermal conductivity does not decrease and the electrical conductivity decreases, so an improvement in ZT value cannot be expected. have

The P-type semiconductor material includes antimony (Sb), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), and tellurium ( A mixture of main raw materials consisting of bismuth telluride (BiTe) containing 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 materials. It is desirable to form it using. For example, the main raw material is Bi-Sb-Te material, and it can be formed by adding Bi or Te in an amount equivalent to 0.001 to 1.0 wt% of the total weight of Bi-Sb-Te. That is, when 100 g of Bi-Sb-Te is added, additionally mixed Bi or Te can be added in the range of 0.001 g to 1 g. The weight range of the material added to the above-mentioned main raw material is significant in that outside the range of 0.001wt% to 0.1wt%, the thermal conductivity does not decrease and the electrical conductivity decreases, so 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 that form a unit cell and face each other are the same, but in this case, the electrical conductivity characteristics of the P-type semiconductor element and the electrical conductivity characteristics of the N-type semiconductor element Considering that these differences act as factors that impede 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 devices opposing each other.

In other words, forming the volumes of the semiconductor devices of the unit cells that are arranged opposite each other in different ways can mean forming a largely different overall shape, forming a wide diameter of one cross-section in a semiconductor device with the same height, or forming a semiconductor device of the same shape with a different volume. It is possible to implement this in a semiconductor device by varying the 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, thereby increasing the volume and improving thermoelectric efficiency.

The first heat exchange layer 60 may be disposed on the first substrate, and the second heat exchange layer 70 may be disposed on the second substrate.

The heat exchange layers 60 and 70 may be disposed on the outer sides of the substrates 10 and 50 so as to be in contact with the target material to be heated or cooled. That is, the first heat exchange layer 60 may be disposed on the lower surface of the first substrate 10, and the second heat exchange layer 70 may be disposed on the upper surface of the second substrate 60.

At this time, if the heat exchange layers 60 and 70 are disposed on the entire substrate, thermal efficiency may decrease, so they can be disposed in a partial area of the substrate.

For example, as shown in FIG. 3, the first substrate 10 may be divided into a central region (S1) and an edge region (S2), and the first heat exchange layer 60 is an edge of the first substrate 10. It may be placed in area S2.

Additionally, the heat exchange layers 60 and 70 may be arranged to be inserted into the substrates 10 and 50. When inserting, a groove large enough to accommodate the heat exchange layer can be formed in the substrate, and then the heat exchange layer can be inserted into the groove. At this time, the depth of the groove and the thickness of the heat exchange layer can be made the same so that one side of the heat exchange layer and one side of the substrate are on the same plane.

That is, one surface of the first heat exchange layer 60 is arranged to be flush with the lower surface of the first substrate 10, and one surface of the second heat exchange layer 70 is flush with the upper surface of the second substrate 60. It can be arranged to form a plane.

Since the heat exchange layers 60 and 70 must be inserted by forming grooves inside the substrates 10 and 50, they must be thinner than the substrates 10 and 50. The thickness of the heat exchange layers 60 and 70 may be approximately 1/3 to 1/2 of the thickness of the substrates 10 and 50.

Additionally, the heat exchange layers 60 and 70 may be made of a material that facilitates heat exchange with the target material. For example, the heat exchange layer may be made of any one of metal, ceramic, diamond, metal composite, ceramic-metal composite, and diamond-metal composite.

Cu, Al, Ni, Mo, Ag, Au, etc. can be used as the metal series, Si, GaAs, InP, GaN, SiC, etc. can be used as the ceramic series, and Cu-W as the metal composite series. Pure metal composites such as , Cu-Mo, etc. can be used, ceramic-metal composites such as SiC-Al, SiC-Al composites, etc. can be used, and diamond-metal composites such as Diamond-Cu, Diamond-Al- Cu complexes, etc. may be used.

Additionally, the heat exchange layers 60 and 70 may have a structure in which media are connected, or they may have a structure in which a pattern is formed within the medium. The pattern may be implemented in various forms. For example, a round-shaped hole may be formed, or a rectangular-shaped hole may be formed to separate the separated medium.

As seen earlier, the stress caused by contraction and expansion becomes more severe towards the outer edge of the board. Accordingly, the heat exchange layers 60 and 70 may be disposed on the edge areas of the substrates 10 and 50.

Referring to FIG. 3, it can be seen that the first heat exchange layer 60 is disposed in the edge area of the first substrate 10. The second heat exchange layer 70 may be arranged in the same structure as the first heat exchange layer 60. Therefore, the following description will focus on the first heat exchange layer 60.

The first heat exchange layer 60 may be disposed starting from a position that is 60% of the distance A between the first electrode layer 20 and the edge of the first substrate 10. That is, the distance B between the start of the first heat exchange layer 60 and the edge of the substrate 10 may be about 60% of the distance A.

In addition, the first electrode layer 20 may be disposed from a position of 0.1 mm to 2.0 mm from the edge of the first substrate 10, and the first heat exchange layer 60 may be disposed 40% to 80% at the edge compared to the first electrode layer 20. It can be placed in a location.

Figure 4 shows various embodiments of the present invention and shows a position where the first heat exchange layer 60 can be disposed.

Figure 4 (a) shows an example in which the first heat exchange layer 60 is disposed in the corner area of the first substrate 10. Four first heat exchange layers may be disposed in each corner area. At this time, the first heat exchange layer 60 may be arranged in a circular shape, and the diameter (C) of the first heat exchange layer may be approximately 5% to 20% of the total width of the first substrate 10.

Figure 4 (b) shows an example in which the first heat exchange layer 60 is disposed in a corner area of the first substrate 10, and in the area where the terminal wire connected to the electrode layer is disposed. At this time, the first heat exchange layer 60 may be arranged in a circular shape, and the diameter (D) of the first heat exchange layer may be approximately 5% to 20% of the total width of the first substrate 10.

Figure 4 (c) shows an example in which the first heat exchange layer 60 is disposed in the edge area of the first substrate 10. At this time, the width E of the first heat exchange layer 60 may be 5% to 10% of the width of the first substrate 10.

Figure 4(d) shows an example in which the first thermal dissipation layer 60 is disposed on the edge area of the first substrate 10, but the corner area is strengthened. The stress applied to the semiconductor device increases as it moves toward the corner area, and as a result, the possibility of damage to the semiconductor device in the corner area increases. Therefore, it is placed in the edge area, but more of it is placed in the corner area to prevent damage to the semiconductor device. At this time, the width (F) of the first heat exchange layer 60 disposed at the edge may be 5% to 10% of the width of the first substrate, and the width (G) of the heat exchange layer widely disposed at the corner area may be 5% to 10% of the width of the first substrate. It may be 5% to 20% of the width. That is, the width (F) of the first heat exchange layer 60 in one direction may be 5% to 10% of the width of the first substrate 20, and the width (G) of the first heat exchange layer 60 in the other direction may be 5% to 10% of the width of the first substrate 20. ) may be 5% to 20% of the width.

Referring to (d) of FIG. 4, it can be seen that the first heat exchange layer is arranged particularly narrowly in the center area (A) of the edge of the first substrate. This is because almost no damage occurs in the center area.

Figure 5 shows an example in which a thermoelectric element is damaged.

Figure 5(a) shows an example where failure (damage) occurred centered on the terminal wire. It can be seen that the damage area (F1) appears wide in the area around the terminal wire and becomes narrower toward the central area.

Figure 5(b) shows an example in which a failure occurs in a corner area of the substrate. It can be seen that the damage area (F2) is concentrated in the corner area.

As described above, the thermoelectric element becomes more susceptible to damage as it moves toward the terminal wire area and corner area, but damage to the thermoelectric element can be prevented by arranging the heat exchange layer in various shapes as shown in FIG. 4.

Although embodiments according to the present invention have been described above, they are merely illustrative, and those skilled in the art will understand that various modifications and equivalent scope of embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the following patent claims.

10: first substrate
20: first electrode layer
30: semiconductor device
40: second electrode layer
50: second substrate
60: first heat exchange layer
70: second heat exchange layer

Claims (13)

first substrate;
a first electrode layer disposed on a first substrate;
a plurality of semiconductor devices disposed on the first electrode layer;
a second electrode layer disposed on the plurality of semiconductor devices;
a second substrate disposed on the second electrode layer; and
A first heat exchange layer disposed in a portion of the first substrate,
The first substrate includes a central area and an edge area, and the first heat exchange layer is disposed in the edge area.
According to paragraph 1,
Further comprising a second heat exchange layer disposed in a partial area of the second substrate,
The second substrate includes a central area and an edge area, and the second heat exchange layer is disposed at an edge area of the second substrate.
According to paragraph 1,
A thermoelectric element wherein one surface of the first substrate and one surface of the first heat exchange layer are disposed on the same plane.
The thermoelectric element of claim 1, wherein the first heat exchange layer is patterned.
According to paragraph 4,
The pattern is a thermoelectric element having a circular or elongated shape.
According to paragraph 1,
A thermoelectric element in which the edge of the first heat exchange layer is disposed at 60% of the distance between the edge of the first substrate and the edge of the first electrode layer.
According to paragraph 1,
The first heat exchange layer is a thermoelectric element disposed at a corner area of the first substrate.
According to paragraph 1,
The first heat exchange layer is a thermoelectric element disposed in an area where a terminal wire connected to the first electrode layer is disposed.
According to paragraph 7 or 8,
The first heat exchange layer may be circular, and the diameter of the circular shape is 5 to 20% of the width of the first substrate.
According to paragraph 1,
The first heat exchange layer is disposed on an edge area of the substrate, and is disposed narrower toward the center from the terminal wire connected to the electrode layer.
According to clause 10,
The first heat exchange layer is a thermoelectric device wherein the width in one direction is 5 to 10% of the width of the first substrate and the width in the other direction is 5 to 20%.
According to paragraph 1,
A thermoelectric element wherein the thickness of the first heat exchange layer is 1/3 to 1/2 of the thickness of the first substrate.
According to paragraph 1,
The first heat exchange layer is a thermoelectric element composed of any one of metal, ceramic, diamond, metal composite, ceramic-metal composite, and diamond-metal composite.

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