Thermoelectric module

Abstract

A thermoelectric module includes a first substrate having a first main surface, a second substrate having a second main surface disposed opposite the first main surface, a plurality of thermoelectric elements disposed between the first main surface and the second main surface, and an electrode disposed on the first main surface and connected to a first thermoelectric element and a second thermoelectric element of the plurality of thermoelectric elements. An insulating layer is disposed on the first main surface and includes a first portion disposed around and separate from the electrode and a second portion disposed between the first thermoelectric element and the second thermoelectric element.

Description

Technical Field

[0001] This invention relates to a thermoelectric module. Background Technology

[0002] Thermoelectric modules utilizing the Seebeck effect and Peltier effect are known. Among these thermoelectric modules, a so-called π-type thermoelectric conversion element is known. The π-type thermoelectric conversion element is constructed by placing a P-type thermoelectric element on one of a pair of separate electrodes disposed on a substrate, and an N-type thermoelectric element on the other electrode, connecting the upper surfaces of both thermoelectric elements to a common electrode disposed on an opposing substrate. In the manufacture of this type of thermoelectric module, the P-type and N-type thermoelectric elements are respectively bonded to the electrodes disposed on the substrate via bonding materials. When solder or the like is used as the bonding material, during bonding via reflow soldering or similar heating, the molten solder may flow due to surface tension, potentially causing the thermoelectric elements to shift position. If the thermoelectric elements shift position, problems such as short circuits may occur due to the thermoelectric elements contacting adjacent electrodes. Japanese Patent Application Publication No. 2022-157777 discloses a method of arranging wall structures around the thermoelectric elements on the electrodes to suppress positional shift of the thermoelectric elements. Summary of the Invention

[0003] To improve the performance of thermoelectric modules, it is desirable to increase the mounting density of thermoelectric elements disposed on the substrate.

[0004] The purpose of this invention is to provide a technology that is beneficial to improving the performance of thermoelectric modules.

[0005] In view of the above-mentioned problems, the thermoelectric module of the present invention is characterized in that it includes: a first substrate having a first main surface; a second substrate having a second main surface arranged opposite to the first main surface; a plurality of thermoelectric elements disposed between the first main surface and the second main surface; and an electrode disposed on the first main surface and connected to a first thermoelectric element and a second thermoelectric element among the plurality of thermoelectric elements, wherein an insulating layer is disposed on the first main surface, the insulating layer comprising: a first portion disposed around the electrode and separately from the electrode; and a second portion disposed between the first thermoelectric element and the second thermoelectric element. Attached Figure Description

[0006] Figure 1 This is a perspective view showing an example of the configuration of the thermoelectric module in this embodiment.

[0007] Figure 2A and Figure 2B This is an explanation Figure 1 The graph shows the increase in the installation density of thermoelectric modules.

[0008] Figures 3A to 3D It means Figure 1 A diagram illustrating an example of the insulation layer configuration for a thermoelectric module.

[0009] Figure 4A and Figure 4B It means Figure 1 A diagram illustrating an example of the insulation layer configuration for a thermoelectric module.

[0010] Figures 5A-5E It means Figure 1 A diagram showing an example of the electrode shape of a thermoelectric module.

[0011] Figures 6A to 6C It means Figure 1 A diagram illustrating an example of the insulation layer configuration for a thermoelectric module.

[0012] Figure 7A and Figure 7B It means Figure 1 A diagram showing a modified example of a thermoelectric module. Detailed Implementation

[0013] The embodiments are described in detail below with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention as claimed, and the combinations of features described in the embodiments are not all necessary for the invention. Two or more features described in the embodiments can be combined arbitrarily. Furthermore, the same reference numerals are used to denote the same or identical components, and repeated descriptions are omitted.

[0014] Reference Figures 1 to 7A , Figure 7B The thermoelectric module 100 of the present disclosure will be described. Figure 1 This is a diagram showing an example of the configuration of the thermoelectric module 100 in this embodiment. Figure 1 The upper side represents a cross-section of the thermoelectric module 100. Figure 1 The lower view shows a top view of an example of the arrangement of electrodes 112 and insulating layer 110 on the substrate 111 of the thermoelectric module 100. The upper cross-sectional view shows the cross-section between A-A' in the lower top view. Furthermore, in the lower top view, to focus on the arrangement of electrodes 112 and insulating layer 110, the description of thermoelectric elements 130 other than the two in the upper left corner is omitted.

[0015] The thermoelectric module 100 includes: a substrate 111 having a main surface 114; a substrate 121 having a main surface 124 arranged opposite to the main surface 114 of the substrate 111; and a plurality of thermoelectric elements 130 disposed between the main surface 114 of the substrate 111 and the main surface 124 of the substrate 121. A plurality of electrodes 112 are disposed on the main surface 114 of the substrate 111. Two thermoelectric elements 130 are connected to each electrode 112 via a bonding material 113 using solder or the like. Figure 1 As shown, the thermoelectric element 130 connected to one electrode 112 can be an N-type thermoelectric element 130n and a P-type thermoelectric element 130p, which have different conductivity types. Similarly, a plurality of electrodes 122 are arranged on the main surface 124 of the substrate 121. Two thermoelectric elements 130 are connected to one electrode 122 via a bonding material 123 using solder or the like. Figure 1 As shown, the thermoelectric element 130 connected to an electrode 112 can be an N-type thermoelectric element 130n and a P-type thermoelectric element 130p with different conductivity types. Figure 1 The thermoelectric module 100 shown has a so-called π-type thermoelectric conversion element structure, with N-type thermoelectric elements 130n and P-type thermoelectric elements 130p alternately connected in series.

[0016] During the manufacture of the thermoelectric module 100, the thermoelectric element 130 is bonded to the electrode 112 via a bonding material 123 using solder or the like. When the thermoelectric element 130 is bonded to the electrode 112 by heating such as reflow soldering, the molten solder flows due to surface tension, which may cause the thermoelectric element 130 to shift position. If the thermoelectric element 130 contacts an electrode 112 that is different from the electrode 112 it is designed to bond to due to this positional shift, a short circuit may occur, leading to a decrease in the characteristics of the thermoelectric module 100. Therefore, in this embodiment, the thermoelectric module 100 has an insulating layer 110 disposed on the main surface 114 of the substrate 111. This insulating layer 110 includes: a portion 110a disposed around and separately from each electrode 112; and a portion 110b disposed between two thermoelectric elements 130 connected to one electrode 112. By configuring the insulating layer 110, the positional displacement of the thermoelectric element 130 caused by the flow of molten solder during reflow soldering can be suppressed.

[0017] Next, use Figure 2A , Figure 2B This explains the advantage of separating the portion 110a of the insulating layer 110, which is arranged around each electrode 112, from the electrode 112. Figure 2A This shows the arrangement of the electrode 112 and the insulating layer 110 in the thermoelectric module 100 of this embodiment. Figure 2B This illustrates the arrangement of electrode 112 and insulating layer 110 in the thermoelectric module of the comparative example. In the thermoelectric module of the comparative example, insulating layer 110 is disposed on electrode 112. Figure 2B The diagram shows the case where the insulating layer 110 is entirely disposed on the electrode 112, but the insulating layer 110 can also be disposed between the electrodes 112.

[0018] exist Figure 2A and Figure 2BIn the configuration shown, thermoelectric elements 130 of the same size are arranged (as shown in the upper left corner of each figure). That is, the openings provided in the insulating layer 110 for arranging the thermoelectric elements 130 are of the same size. Furthermore, the minimum forming width when forming the insulating layer 110 is set to length D1. Moreover, in the comparative example thermoelectric module, the minimum distance between the electrodes 112 required for processing when forming the electrodes 112 is set to length D2. Furthermore, in the comparative example thermoelectric module, considering the forming accuracy and positional offset when forming the insulating layer 110 on the electrodes 112, the forming width of the insulating layer 110 on the electrodes 112 is set to length D3.

[0019] like Figure 2A As shown, in the thermoelectric module 100 of this embodiment, the thermoelectric elements 130 are arranged separately at intervals of length D1 in both the vertical and horizontal directions. On the other hand, in Figure 2B In the comparative example thermoelectric module shown, the spacing between thermoelectric elements 130 connected to adjacent electrodes 112 is a length Dt = D2 + D3 × 2 in both the vertical and horizontal directions. The length D3, which is the width formed on the electrode 112, can be set to a length greater than or equal to D1 (D1 ≤ D3) depending on the forming accuracy and positional offset when forming the insulating layer 110 on the electrode 112. Therefore, the relationship between the length D1, which is the spacing between the thermoelectric elements 130 in the thermoelectric module 100 of this embodiment, and the length Dt, which is the spacing between the thermoelectric elements 130 in the comparative example thermoelectric module, is Dt = D2 + D3 × 2 > D1. Figure 2A , Figure 2B It is also clear that the thermoelectric module 100 of this embodiment requires a smaller area to configure the same number of thermoelectric elements 130 compared to the thermoelectric module of the comparative example. In other words, by separating the portion 110a of the insulating layer 110 that is configured around the electrode 112 from the electrode 112, the mounting density of the thermoelectric elements 130 disposed on the substrate 111 can be increased. That is, while suppressing the occurrence of defects by suppressing the positional displacement of the thermoelectric elements 130 during manufacturing, the number of thermoelectric elements 130 per unit area can be increased. It can be said that the thermoelectric module 100 of this embodiment has a structure suitable for performance improvement.

[0020] Next, the structure of insulating layer 110 will be described. Figure 1 In the configuration shown, the insulating layer 110 is formed to continuously surround each thermoelectric element 130. This suppresses positional displacement of the thermoelectric elements 130. Figure 1As shown, the upper surface of the insulating layer 110 may be positioned closer to the main surface 124 of the substrate 121 than the surface of the thermoelectric element 130 opposite to the electrode 112 disposed on the substrate 111. Alternatively, for example, the upper surface of the insulating layer 110 may be positioned at the same height as the surface of the thermoelectric element 130 opposite to the electrode 112 disposed on the substrate 111.

[0021] By positioning the upper surface of the insulating layer 110 closer to the substrate 121 than the surface of the thermoelectric element 130 opposite to the electrode 112, movement of the thermoelectric element 130 can be suppressed even during processes such as reflow soldering when the solder used as the bonding material 113 melts and flows. For example, the upper surface of the insulating layer 110 may be positioned at a location at least 2 μm closer to the main surface 124 of the substrate 121 than the surface of the thermoelectric element 130 opposite to the electrode 112. Furthermore, for example, the upper surface of the insulating layer 110 may be positioned at a location at least 3 μm closer to the main surface 124 of the substrate 121 than the surface of the thermoelectric element 130 opposite to the electrode 112. Moreover, for example, the upper surface of the insulating layer 110 may be positioned at a location at least 4 μm closer to the main surface 124 of the substrate 121 than the surface of the thermoelectric element 130 opposite to the electrode 112. Furthermore, even if the upper surface of the insulating layer 110 is at approximately the same height as the surface of the thermoelectric element 130 facing the electrode 112, the flow of molten solder can be suppressed, thereby preventing the positional displacement of the thermoelectric element 130. On the other hand, if the height of the insulating layer 110 increases, it may interfere with the substrate 121, the electrode 122 disposed on the substrate 121, etc. Therefore, the upper surface of the insulating layer 110 is disposed at the same height as the surface of the thermoelectric element 130 facing the electrode 122 disposed on the substrate 121, or closer to the main surface 114 of the substrate 111 than the surface of the thermoelectric element 130 facing the electrode 122 disposed on the substrate 121. The upper surface of the insulating layer 110 may be disposed at a position that is, for example, 2 μm or more closer to the main surface 114 of the substrate 111 than the surface of the thermoelectric element 130 facing the electrode 122, or it may be disposed at a position that is 10 μm or more, and even 50 μm or more closer to the main surface 114 of the substrate 111. For example, the upper surface of the insulating layer 110 may be disposed at a height from the same height as the surface of the thermoelectric element 130 opposite to the electrode 112 to a portion up to half the height between the substrate 111 and the substrate 121 in the thermoelectric element 130, or up to a portion up to one-third of the height, or up to a portion up to one-fifth of the height. Furthermore, for example, the upper surface of the insulating layer 110 may be disposed at a height from the surface of the electrode 112 that is 1 to 100 times the thickness of the bonding material 113, or at a height that is 2 to 20 times the thickness of the bonding material 113, or at a height that is 3 to 7 times the thickness of the bonding material 113. Here, the descriptions of upper and lower limits such as "1 to 100 times," "2 to 20 times," and "3 to 7 times" are not limited to the described combinations and can be combined with each other. Furthermore, for example, the description "1 to 100 times" means "more than 1 times and less than 100 times." The same applies to the upper and lower limits of the numerical ranges described below.

[0022] exist Figure 1In the configuration shown, the insulating layer 110 is formed to continuously surround each thermoelectric element 130, but is not limited thereto. The insulating layer 110 may also be formed to intermittently surround each thermoelectric element 130. For example, as Figure 3A As shown, the portion 110b of the insulating layer 110 disposed between two thermoelectric elements 130 connected to the same electrode 112 can be divided into two portions protruding from the portion 110a of the insulating layer 110 surrounding the electrode 112. In this case, as... Figure 3A As shown, a portion 110b of the insulating layer 110 may not be disposed on the electrode 112. Furthermore, as... Figure 3B As shown, portion 110b of the insulating layer 110 can also be disposed separately from portion 110a of the insulating layer 110. Figure 3B In the configuration shown, a portion 110b of the insulating layer 110 is formed across the electrode 112, but it can also be as follows: Figure 3C As shown, a portion is formed on electrode 112. Alternatively, it can also be as follows: Figure 3D As shown, portion 110b of insulating layer 110 is separate from portion 110a of insulating layer 110 and is composed of two or more portions.

[0023] Furthermore, the portion 110a of the insulating layer 110 surrounding the electrode 112 may intermittently surround the electrode 112, rather than continuously. For example, as Figure 4A As shown, the insulating layer 110 can be disposed at each corner of the thermoelectric element 130 to suppress positional displacement. For example, as... Figure 4B As shown, the insulating layer 110 can be disposed on each side of the thermoelectric element 130 to suppress positional displacement. Figure 4B In the configuration shown, the portion of the insulating layer 110 corresponding to each side of the thermoelectric element 130 is composed of a single element, but it can also be divided into two or more. Furthermore, for example, it can also be combined... Figure 4A The structure shown is Figure 4B The structure shown.

[0024] exist Figures 3A to 3D , Figure 4A , Figure 4B In the configuration shown, in the orthographic projection of the main surface 114 of the substrate 111, a portion of the insulating layer 110 arranged to surround a thermoelectric element 130 has an intermittent rectangular shape surrounding the thermoelectric element. In this case, as... Figures 3A to 3D , Figure 4A , Figure 4BAs shown, the insulating layer 110 can be configured to form a portion of each of the four sides of the rectangle. This effectively suppresses the positional shift of the thermoelectric element 130. However, it is not limited to this configuration; the insulating layer 110 can be configured to form only a portion of the four sides of the rectangle. Even with only a portion configured, configuring the insulating layer 110 can suppress the positional shift of the thermoelectric element 130 compared to not configuring the insulating layer 110.

[0025] like Figure 1 As shown on the lower side, in the orthographic projection of the main surface 124 of the substrate 111, the inner edge shape of the portion of the insulating layer 110 arranged to surround a thermoelectric element 130 can be approximately the same as the outer edge shape of the thermoelectric element 130. Furthermore, considering manufacturing variations in the insulating layer 110 and the thermoelectric element 130, the inner edge shape of the portion of the insulating layer 110 arranged to surround a thermoelectric element 130 can also be larger than the outer edge of the thermoelectric element 130. However, if the inner edge of the portion of the insulating layer 110 arranged to surround a thermoelectric element 130 becomes larger, the mounting density of the thermoelectric element 130 will decrease. Therefore, although it also depends on the size of the thermoelectric element 130, the length between the inner edge of the insulating layer 110 and the outer edge of the thermoelectric element 130 can be, for example, less than 200 μm, less than 100 μm, less than 50 μm, and even less than 20 μm. Furthermore, for example, in the orthographic projection of the main surface 124 of the substrate 111, when the thermoelectric element 130 is approximately square, the length between the inner edge of the insulating layer 110 and the outer edge of the thermoelectric element 130 can be less than 20% of one side of the square thermoelectric element 130. In this case, the length between the inner edge of the insulating layer 110 and the outer edge of the thermoelectric element 130 can be, for example, less than 10% of one side of the square thermoelectric element 130, less than 5%, or less than 2%. Furthermore, for example, in the orthographic projection of the main surface 124 of the substrate 111, assuming the thermoelectric element 130 has A[mm]... 2 The size of the insulation layer 110. In this case, the length between the inner edge of the insulation layer 110 and the outer edge of the thermoelectric element 130 may be less than 0.2×√A[mm], less than 0.1×√A[mm], less than 0.05×√A[mm], or less than 0.02×√A[mm].

[0026] exist Figure 1 , Figures 3A to 3D , Figure 4A , Figure 4B In the configuration shown, electrode 112 is depicted as rectangular, but the shape of electrode 112 is not limited to rectangular. Figures 5A-5E An example of the shape of electrode 112 is shown. Electrode 112 can be as follows: Figure 5A The shape shown has rounded corners, or it can be like... Figure 5BThe end shown has a rounded shape. Figure 5A In the configuration shown, all four corners are rounded, but only some corners may be rounded. Furthermore, for example, the corners of electrode 112 may also be chamfered along a straight line. Additionally, the width of the portion of electrode 112 disposed between the two portions to be joined to the thermoelectric element 130 may be narrower than the portion to be joined to the thermoelectric element 130. For example, it may be as follows: Figure 5C As shown, the portion to be joined to the thermoelectric element 130 is rectangular in shape, and the width between them is less than the length of one side of the rectangle. Alternatively, it can be as follows: Figure 5D As shown, the four corners (or part of the corners) of the rectangular shape of the portion to be joined with the thermoelectric element 130 can be chamfered. Furthermore, for example, it can be as follows: Figure 5E As shown, the portion to be joined with the thermoelectric element 130 has a circular shape, and the electrode 112 has a configuration in which two circular portions are connected by a portion narrower than the diameter of the circle. The shape of the electrode 112 can be selected appropriately based on the shape of the thermoelectric element 130, the bonding strength between the electrode 112 and the thermoelectric element 130, etc.

[0027] The shape of electrode 112 can be chosen appropriately, but the length between the portion 110a of the insulating layer 110 surrounding electrode 112 and the outer edge of electrode 112 in the orthographic projection of the main surface 124 of substrate 111 can be considered as follows: If the length between the portion 110a of the insulating layer 110 and electrode 112 is increased, the size of electrode 112 becomes relatively smaller, and the resistance value of electrode 112 increases. As a result, the proportion of power consumed in electrode 112 may increase, leading to a decrease in the performance of thermoelectric module 100. In addition, it may also lead to a decrease in the bonding strength between electrode 112 and thermoelectric element 130. On the other hand, if the length between the portion 110a of the insulating layer 110 and electrode 112 is decreased, the relative size of electrode 112 becomes larger, thus suppressing the power consumption problem and bonding strength problem of electrode 112. However, during processes such as reflow soldering, solder used as bonding material 113 may leak through the portion where the insulating layer 110 is not disposed, causing a short circuit with adjacent electrodes. Furthermore, if the length between portion 110a of the insulating layer 110 and the electrode 112 is reduced, high alignment accuracy is required in the forming process of the insulating layer 110. Therefore, for example, alignment may take time, which may lead to a decrease in manufacturing efficiency.

[0028] Therefore, for example, in the orthographic projection of the main surface 124 of the substrate 111, when the thermoelectric element 130 is approximately square, the length between the portion of the insulating layer 110a closest to the electrode 112 and the electrode 112 can be 5% to 30% of one side of the square of the thermoelectric element 130. Furthermore, in this case, the length between the portion of the insulating layer 110a closest to the electrode 112 and the electrode 112 can be, for example, more than 7% of one side of the square of the thermoelectric element 130, or more than 10%, or more than 15%. On the other hand, the length between the portion of the insulating layer 110a closest to the electrode 112 and the electrode 112 can be, for example, less than 25% of one side of the square of the thermoelectric element 130, or less than 20%, or less than 18%. Furthermore, for example, in the orthographic projection of the main surface 124 of the substrate 111, assuming the thermoelectric element 130 has A[mm]... 2 The size of the thermoelectric element 130. In this case, the length between the portion of the insulating layer 110a closest to the electrode 112 and the electrode 112 can be 0.05×√A [mm] to 0.3×√A [mm], for example, 0.07×√A [mm] to 0.25×√A [mm], or for example, 0.1×√A [mm] to 0.2×√A [mm], or for example, 0.15×√A [mm] to 0.18×√A [mm]. Furthermore, for example, although it also depends on the size of the thermoelectric element 130, the length between the portion of the insulating layer 110a closest to the electrode 112 and the electrode 112 can be, for example, 50 μm or more, or for example, 75 μm or more, or for example, 100 μm or more, or even more than 150 μm. On the other hand, the length between the portion of the insulating layer 110 110a closest to the electrode 112 and the electrode 112 can be, for example, less than 300 μm, less than 250 μm, less than 200 μm, or even less than 180 μm. This allows for the suppression of solder leakage and reduced manufacturing efficiency while simultaneously suppressing the increase in the resistance of the electrode 112.

[0029] Here, as Figure 1 As shown on the lower side, in the orthographic projection of the main surface 124 of the substrate 111, the electrode 112 can be formed to be smaller than the thermoelectric element 130. As described above, if the electrode 112 becomes smaller, the resistance value of the electrode 112 increases, which may lead to a decrease in the performance of the thermoelectric module 100 and a decrease in the bonding strength between the electrode 112 and the thermoelectric element 130. On the other hand, if the electrode 112 becomes larger, the solder used as the bonding material 113 may leak during processes such as reflow soldering, resulting in a short circuit with adjacent electrodes. Therefore, in the orthographic projection of the main surface 124 of the substrate 111, when the thermoelectric element 130 has A[mm 2When the size is such that, in the orthographic projection of the main surface 124 of the substrate 111, the size (area) of the electrode 112 can, for example, be 0.5 × Å [mm²]. 2 ]~0.9×A[mm 2 The size of electrode 112. For example, the size (area) of electrode 112 can be 0.64 × A [mm²]. 2 ]~0.81×A[mm 2 The size of [] can be, for example, 0.67 × A [mm]. 2 ]~0.72×A[mm 2 The size of the electrode is such that the resistance between the electrode 112 and the thermoelectric element 130 increases and the bonding strength decreases, while also suppressing the occurrence of adverse conditions such as short circuits between the electrodes.

[0030] exist Figures 3A to 3D , Figure 4A , Figure 4B The configuration shown illustrates an example of the insulating layer 110 being configured for two electrodes 112, but the insulating layer 110 can be configured for more electrodes 112. Figure 6A This is an example of the arrangement of the insulating layer 110 when the insulating layer 110 continuously surrounds each thermoelectric element 130, and the electrodes 112 are further arranged in the vertical and horizontal directions shown in the figure. Furthermore, Figure 6B It is aimed at Figure 4A , Figure 6C It is aimed at Figure 3B The configurations shown illustrate examples of the insulating layer 110 configuration when the electrodes 112 are further arranged in the vertical and horizontal directions. Similarly, in other configurations, even when the electrodes 112 are further arranged in the vertical and horizontal directions, the insulating layer 110 can be appropriately configured. Furthermore, the shape of the electrodes 112 is not limited to a rectangular shape; for example, it can use... Figures 5A-5E The shape shown.

[0031] Furthermore, the insulating layer 110 is not limited to being configured only on the main surface 114 of the substrate 111. For example... Figure 7A As shown, an insulating layer 120 may also be disposed on the main surface 124 of the substrate 121, which is arranged opposite to the main surface 114 of the substrate 111. Furthermore, as... Figure 7BAs shown, the insulating layer 110 may not be disposed on the main surface 114 of the substrate 111, but the insulating layer 120 may be disposed on the main surface 124 of the substrate 121. For example, in the manufacturing process of the thermoelectric module 100, it is sufficient to dispose of the insulating layer on the substrates 111 and 121 that have electrodes for connecting the thermoelectric element 130. This can suppress the positional displacement of the thermoelectric element 130. For example, the insulating layer 120 disposed on the main surface 124 of the substrate 121 includes: a portion disposed around and separate from each electrode 122; and a portion disposed between two thermoelectric elements 130 connected to one electrode 122. Other configurations of the insulating layer 120 may have the same configurations as the various configurations of the insulating layer 110 described above. Therefore, the description of the insulating layer 120 is omitted.

[0032] The following describes the materials of each component of the thermoelectric module 100.

[0033] Substrate 111 and substrate 121 can be insulating substrates. For example, substrate 111 and substrate 121 can be made of plastic film. As plastic film, polyimide film, polyamide film, polyetherimide film, polyaramid film, polyamideimide film, glass epoxy sheet, etc., can be used. Substrate 111 and substrate 121 can be substrates of the same material or substrates of different materials. The thickness of substrate 111 and substrate 121 can be 1μm to 1000μm, for example 10μm to 500μm, or even 20μm to 100μm. Furthermore, the materials used for substrate 111 and substrate 121 are not limited to plastic. For example, ceramics such as alumina and aluminum nitride can also be used as substrate 111 and substrate 121. Additionally, conductive materials covered by an insulating layer, such as aluminum substrates with an alumina layer formed on their surface, can also be used for substrate 111 and substrate 121.

[0034] In the thermoelectric module 100, the thermoelectric element 130 can be arranged between the substrate 111 and the substrate 121 in a manner in which an N-type thermoelectric element 130n and a P-type thermoelectric element 130p are connected in series. For example... Figure 1 As shown on the upper side, thermoelectric elements 130n and 130p do not necessarily need to be arranged alternately; they can be arranged in an appropriate order according to the configuration of electrodes 112 and 122 disposed on substrates 111 and 121. Thermoelectric element 130 can be made of various thermoelectric materials such as bismuth-tellurium, telluride, antimony-tellurium, zinc-antimony, silicon-germanium, bismuth selenide, silicide, cobaltite, oxides, and sulfides. The thickness of thermoelectric element 130 in the direction sandwiched between substrates 111 and 121 can be, for example, 10 μm to 1000 μm, further, for example, 20 μm to 500 μm, and even more, 50 μm to 200 μm, or even 80 μm to 120 μm.

[0035] Electrodes 112 and 122 can be made of materials such as gold, silver, copper, molybdenum, nickel, aluminum, rhodium, platinum, chromium, palladium, tungsten, stainless steel, or their alloys. In addition to metallic materials, electrodes 112 and 122 can also be formed using a paste containing solvents and resins. When using a paste, the solvents and resins can be removed by firing or other methods. Silver paste, aluminum paste, etc., can be used as the paste.

[0036] Methods for forming electrodes 112 and 122 include: processing into a specified pattern shape by means of known physical processing, chemical processing, or a combination thereof, primarily photolithography; or forming electrode patterns by means of screen printing, stencil printing, inkjet printing, etc. Methods for forming electrodes before pattern formation include vacuum film formation methods such as vacuum evaporation, sputtering, ion plating, and other PVD methods (physical vapor deposition), thermal CVD, atomic layer evaporation (ALD), and other CVD methods (chemical vapor deposition); or various coating methods such as dip coating, spin coating, spray coating, gravure coating, mold coating, and doctor blade coating; wet processes such as electroplating; silver halide methods; electrolytic plating; electroless plating; and lamination of metal foil, etc., which are appropriately selected according to the metal material. In addition, when substrates 111 and 121 are made of ceramics such as alumina and aluminum nitride, electrodes 112 and 122 can also be formed using methods such as DBC (Direct Bonded Copper) and AMB (Active Metal Brazing).

[0037] Electrodes 112 and 122 require high conductivity. High conductivity can be easily achieved by electrodes formed using deposition methods or vacuum deposition methods. Therefore, electrodes 112 and 122 can also be formed using vacuum deposition methods such as vacuum evaporation and sputtering, as well as electrolytic deposition and electroless deposition methods. Although the specific dimensions and dimensional accuracy requirements of the formed electrodes 112 and 122 depend on the requirements, electrodes 112 and 122 can also be easily formed using hard masks such as metal masks. Furthermore, when forming a film using vacuum deposition methods, considering the purpose of improving adhesion to the substrate 111 and substrate 121 and removing moisture, film formation can be performed while heating the substrate 111 and substrate 121 within a range that does not damage the characteristics of the substrate 111 and substrate 121. When forming a film using deposition methods, electrolytic deposition can be used to further form a film on top of a film formed using electroless deposition methods.

[0038] The thickness of electrodes 112 and 122 can be, for example, 0.01 μm to 200 μm, or 1 μm to 100 μm, or even 10 μm to 50 μm. The thickness of electrodes 112 and 122 can be appropriately set according to the required resistance value of electrodes 112 and 122.

[0039] As bonding materials 113 and 123 for bonding the thermoelectric element 130 to electrodes 112 and 122, solder such as solder paste can be used. Solder paste can be applied to electrodes 112 and 122 with high precision and in a short time, for example, by screen printing using a stencil. Examples of known solders include Sn, Sn / Pb alloys, Sn / Ag alloys, Sn / Cu alloys, Sn / Ag / Cu alloys, Sn / Sb alloys, Sn / In alloys, Sn / Zn alloys, Sn / In / Bi alloys, Sn / In / Bi / Zn alloys, Sn / Bi / Pb / Cd alloys, Sn / Bi / Pb alloys, Sn / Bi / Cd alloys, Bi / Pb alloys, Sn / Bi / Zn alloys, Sn / Bi alloys, Sn / Bi / Pb alloys, Sn / Pb / Cd alloys, and Sn / Cd alloys. After the reflow soldering process of joining the thermoelectric element 130 with electrodes 112 and 122, the thickness of the bonding materials 113 and 123 can be, for example, 2μm to 20μm, or, for example, 5μm to 15μm, or, for example, 7μm to 12μm. The thickness that can be stably formed by a large number of joints between electrodes 112 and 122 and thermoelectric element 130 can be appropriately selected.

[0040] Figure 1 , Figure 7A , Figure 7B Although not illustrated, a solder receiving layer may be disposed between the bonding material 113, the bonding material 123, and the thermoelectric element 130. The solder receiving layer improves the bonding strength between the thermoelectric element 130 and the bonding materials 113 and 123, and is directly bonded to the thermoelectric element 130. The solder receiving layer may contain a metallic material. The metallic material may be at least one selected from gold, silver, nickel, aluminum, rhodium, platinum, chromium, palladium, tin, and alloys containing any of these metallic materials. It may be a two-layer structure of gold, silver, nickel, aluminum, or tin and gold. From the viewpoints of material cost, high thermal conductivity, and bonding stability, silver, nickel, and aluminum are more suitable as solder receiving layers.

[0041] The thickness of the solder acceptor layer can be, for example, 0.01 μm to 10 μm, or, for example, 0.05 μm to 8 μm, or, for example, 0.2 μm to 4 μm, or, for example, 0.5 μm to 3 μm. If the thickness of the solder acceptor layer is within this range, the adhesion to the surface of the thermoelectric element 130 and the adhesion to the bonding materials 113 and 123 are excellent, resulting in a highly reliable bond. Furthermore, since both high electrical conductivity and high thermal conductivity are maintained, the thermoelectric performance of the thermoelectric module 100 is ultimately maintained without degradation. The solder acceptor layer can be a single layer formed directly from metal material, or it can be a multilayer layer formed by laminating two or more layers of metal material.

[0042] The solder acceptor layer can be formed using the aforementioned metallic materials. From the viewpoint of maintaining thermoelectric performance, the solder acceptor layer requires high electrical conductivity and high thermal conductivity. Therefore, the solder acceptor layer can be formed using the aforementioned electrolytic plating method, electroless plating method, or vacuum film deposition method.

[0043] While the materials of insulating layers 110 and 120 are not particularly limited, from the viewpoint of suppressing the wetting and spreading of solder used as bonding materials 113 and 123, solder resists may be used. Examples of solder resists include acrylic resins, epoxy resins, polyurethane resins, and polyimide resins. Among these, from the viewpoint of heat resistance, epoxy resins and polyimide resins may be used as materials for insulating layers 110 and 120.

[0044] Methods for forming insulating layers 110 and 120 include those involving processing into a predetermined pattern shape using known physical or chemical processes, primarily photolithography, or a combination thereof. Additionally, methods for forming insulating layer 110 include directly forming the pattern of insulating layer 110 using screen printing, stencil printing, inkjet printing, etc. From an insulating point of view, insulating layers 110 and 120 may, for example, have a pattern of 1.0 × 10⁻⁶. 11 Ω / m 2 The above-mentioned surface resistivity layer. For example, from the viewpoint of suppressing the wetting and spreading of solder, the contact angle of insulating layer 110 and insulating layer 120 with water can be 60° or more. Furthermore, insulating layer 110 and insulating layer 120 can be layers with a contact angle of 60° to 90° with water. For example, insulating layer 110 and insulating layer 120 can have a contact angle of 70° to 80° with water.

[0045] The heights of insulating layers 110 and 120 can be appropriately adjusted within the range described above, based on the thickness of thermoelectric element 130, the thickness of bonding material 113 and bonding material 123 (e.g., solder (and solder receiving layer)), the thickness of electrode 112 and electrode 122, and the length between the main surface 114 of substrate 111 and the main surface 124 of substrate 121. Furthermore, the thicknesses of the portions of insulating layers 110 and 120 disposed on the main surfaces 114 and 124 of substrate 111 and substrate 121, and the portions disposed on electrode 112 and electrode 122, can be different or the same. For example, when solder resist is uniformly applied to the main surfaces 114 and 124 of substrates 111 and 121 as the materials for insulating layers 110 and 120, and an opening is made in the portion where the thermoelectric element 130 is to be disposed using photolithography or the like, the thickness of the portion of insulating layer 110 and 120 disposed on the main surfaces 114 and 124 of substrates 111 and 121 may be different from the thickness of the portion disposed on electrodes 112 and 122. On the other hand, in this case, the height of the portion of insulating layer 110 and 120 disposed on the main surfaces 114 and 124 of substrates 111 and 121 and the portion disposed on electrodes 112 and 122 from the main surfaces 114 and 124 of substrates 111 and 121 may be the same. Furthermore, when the pattern of the insulating layer 110 is directly formed using methods such as screen printing, the thickness of the portion of the insulating layer 110 and the insulating layer 120 disposed on the main surface 114 and the main surface 124 of the substrate 111 and the substrate 121 can be the same as the thickness of the portion disposed on the electrode 112 and the electrode 122.

[0046] As explained above, the thermoelectric module 100 of this embodiment includes an insulating layer 110 (insulating layer 120) formed around each thermoelectric element 130. This suppresses positional misalignment of the thermoelectric elements 130, thus preventing adverse conditions such as short circuits and improving the manufacturing yield of the thermoelectric module 100. Furthermore, the portion 110a surrounding the electrode 112 (electrode 122) in the insulating layer 110 (insulating layer 120) is separately disposed from the electrode 112 (electrode 122). This increases the mounting density of the thermoelectric elements 130. In other words, the thermoelectric module 100 of this embodiment can be said to have a configuration suitable for improving the performance of the thermoelectric module.

[0047] The invention is not limited to the above-described embodiments, and various modifications and alterations can be made within the scope of the inventive intent.

Claims

1. A thermoelectric module, characterized in that, include: The first substrate has a first main surface; The second substrate has a second main surface arranged opposite to the first main surface; Multiple thermoelectric elements are disposed between the first main surface and the second main surface; And electrodes, disposed on the first main surface, and connected to the first thermoelectric element and the second thermoelectric element among the plurality of thermoelectric elements, wherein, An insulating layer is disposed on the first main surface, the insulating layer comprising: a first portion disposed around the electrode ground and separately from the electrode; And the second part is disposed between the first thermoelectric element and the second thermoelectric element.

2. The thermoelectric module according to claim 1, characterized in that, The insulating layers are formed continuously or intermittently around the first thermoelectric element and the second thermoelectric element, respectively.

3. The thermoelectric module according to claim 2, characterized in that, In the orthographic projection of the first main surface, the portion of the insulating layer arranged around the first thermoelectric element surrounds the first thermoelectric element in a discontinuous rectangular shape and is configured to constitute a portion of each of the four sides of the rectangle.

4. The thermoelectric module according to claim 2, characterized in that, In the orthographic projection of the first main surface, the inner edge shape of the portion of the insulating layer arranged around the first thermoelectric element is the same as or larger than the outer edge of the first thermoelectric element.

5. The thermoelectric module according to claim 1, characterized in that, In the orthographic projection of the first main surface, the plurality of thermoelectric elements each have an Amm. 2 Size, The length between the portion of the first part closest to the electrode and the electrode is greater than 0.05×√A mm and less than 0.3×√A mm.

6. The thermoelectric module according to claim 1, characterized in that, The upper surface of the insulating layer is positioned at the same height as the surfaces of the first and second thermoelectric elements opposite to the electrodes, or positioned closer to the second main surface than the opposing surfaces.

7. The thermoelectric module according to claim 1, characterized in that, The upper surface of the insulating layer is positioned at a position that is at least 2 μm closer to the second main surface than the surfaces of the first and second thermoelectric elements that are opposite to the electrodes.

8. The thermoelectric module according to claim 1, characterized in that, The first thermoelectric element and the second thermoelectric element have different conductivity types.

9. The thermoelectric module according to claim 1, characterized in that, When the electrode is used as the first electrode and the insulating layer is used as the first insulating layer... The thermoelectric module further includes a second electrode, which is disposed on the second main surface and connected to the first thermoelectric element and a third thermoelectric element among the plurality of thermoelectric elements. A second insulating layer is disposed on the second main surface, the second insulating layer comprising: a third portion disposed around the second electrode and separately from the second electrode; And a fourth part, disposed between the first thermoelectric element and the third thermoelectric element.

10. The thermoelectric module according to claim 1, characterized in that, The second part is not disposed on the electrode.

11. The thermoelectric module according to claim 1, characterized in that, The second part is configured separately from the first part.

Images