JP3956405B2 - Thermoelectric module manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a thermoelectric module in which a plurality of thermoelectric elements are thermally connected in parallel.ofIt relates to a manufacturing method.
[0002]
[Prior art]
In a thermoelectric module, a plurality of thermoelectric elements (Peltier elements) are juxtaposed between a pair of electrode plates, and the thermoelectric elements are electrically connected in series by bonding thermoelectric elements to bonding electrodes provided on the electrode plates. In addition, the P-type thermoelectric elements and the N-type thermoelectric elements are alternately connected, and the thermoelectric elements are connected and arranged so as to be thermally parallel to each other. This electrode plate acts as a heat dissipation side.
[0003]
At this time, each thermoelectric element was bonded to the bonding electrode by placing each thermoelectric element on each bonding electrode on the electrode plate. In this case, a large number of P-type and N-type thermoelectric elements must be accurately placed and joined on each joining electrode without making a mistake in arrangement, which is difficult to manufacture and has a very poor yield.
For this purpose, in Japanese Patent Application Laid-Open No. 58-64075, a P-type thermoelectric element material and an N-type thermoelectric element material are alternately arranged using a rod-shaped thermoelectric element material, and the plate is fixed with a heat-resistant insulating material therebetween. It is shown that the upper and lower surfaces are metalized by vapor deposition so that they are electrically in series, and a copper plate or the like is welded to the metallized surface with solder or the like, and cut in a direction perpendicular to the rod-shaped direction. Has been.
[0004]
[Problems to be solved by the invention]
In this case, since it is not necessary to consider the positioning of the individual thermoelectric elements, manufacturing is easy at this point. However, the heat-resistant insulating material remaining between the thermoelectric elements after cutting causes a thermal short circuit between the heat absorbing part and the heat radiating part. It has a big problem that good performance cannot be obtained because performance is lowered. Moreover, it is difficult to manage the soldering accuracy of the copper plate and the flatness of the copper plate after cutting.
[0005]
  The present invention has been made in view of the above points, and the object of the present invention is a thermoelectric module that is easy to manufacture and can obtain good performance.ofTo provide a manufacturing method.
[0006]
[Means for Solving the Problems]
  Thus, the thermoelectric module according to the present inventionThe manufacturing method comprises an electrode plate in which a large number of bonding electrodes to which thermoelectric elements are bonded are arranged in a required pattern and the bonding electrodes are electrically connected to adjacent bonding electrodes, and a thermoelectric element, A method of manufacturing a thermoelectric module in which a P-type thermoelectric element and an N-type thermoelectric element are bonded to a bonding electrode and electrically connected alternately between two electrode plates, the bonding electrode to which the thermoelectric element is bonded It is composed of one conductive metal plate provided in large numbers, and at least one of a bridge for electrical connection and a bridge for exclusive use of mechanical connection to be excised, which is adjacent to a junction electrode arranged in a predetermined pattern. A metal pattern plate, which is connected by one side and all junction electrodes are integrated by the bridge, is used as the electrode plate. After attaching the P-type thermoelectric element material and the N-type thermoelectric element material straddling the bonding electrodes, the thermoelectric element materials are cut to separate the thermoelectric elements on the bonding electrodes, and at the same time, the bridge dedicated for mechanical connection After that, attach the other electrode plate, which has been cut in advance to the mechanical connection bridge, to the thermoelectric element.It has a special feature.The thermoelectric element material is aligned at a predetermined interval by bonding the thermoelectric element material to the bonding electrode of the electrode plate. In this state, the thermoelectric element material is cut and simultaneously the bridge for mechanical connection is also cut.
[0008]
  At this time,It is preferable to use a metal pattern plate with a thermal stress absorber.Further, it is preferable to use a plate in which a mechanical connection dedicated bridge is floated from the substrate or a plate in which the electrical connection dedicated bridge is thinner than the bonding electrode and deviated toward the substrate.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment of the present invention will be described. A thermoelectric module M shown in FIGS. 1 to 4 includes a large number of thermoelectric elements 1 that are Peltier elements arranged between a pair of electrode plates 2 and 2, and a P-type thermoelectric element. By alternately connecting the element 1 and the N-type thermoelectric element 1 by the joining electrodes 30 provided on the opposing surfaces of the electrode plates 2 and 2, all the thermoelectric elements 1 are electrically connected in series and thermally in parallel. Connected, both ends of the series circuit composed of the joining electrode 30 and the thermoelectric element 1 in the electrode plate 2 are formed on the opposing surfaces of the electrode plates 2 and terminal portions 36 and 36 for external connection. Are connected to the lead wires 38, 38. A cylindrical seal frame 4 is also arranged between the electrode plates 2 and 2, and both ends are joined to the electrode plates 2 and 2, and the seal frame surrounds the arrangement portion of the total thermoelectric element 1. 4 and the electrode plates 2 and 2 seal the space in which the thermoelectric element 1 is disposed.
[0013]
Here, as is apparent from FIG. 1, the thermoelectric elements 1 are arranged in a grid pattern, but in the column (vertical direction) in FIG. 1, as shown in FIG. 2, P-type thermoelectric elements are arranged. The elements 1 and the N-type thermoelectric elements 1 are alternately arranged, and in the row (lateral direction) in FIG. 1, only the N-type thermoelectric element 1 or only the P-type thermoelectric element 1 is present as shown in FIG. The arrangement is determined to line up.
[0014]
The arrangement of the P-type thermoelectric element 1 and the N-type thermoelectric element 1 is performed in this way, as is apparent from the manufacturing method described below, when each thermoelectric element 1 is bonded to the bonding electrode 30 individually. The rod-shaped P-type thermoelectric element material and the N-type thermoelectric element material are attached to extend over the plurality of bonding electrodes 30, respectively, and then the rod-shaped thermoelectric element material is cut so that the thermoelectric element 1 on each bonding electrode 30. This is because they are separated.
[0015]
A method for manufacturing the thermoelectric module M will be described. First, the electrode plate 2 will be described. As the electrode plate 2 used here, a metal pattern plate 3 having a bonding electrode 30 bonded to the surface of a ceramic substrate 20 is used. 4 to 7 show the metal pattern plate 3 before joining to the ceramic substrate 20. The bonding electrodes 30 are connected to each other by a mechanical connection bridge 32 in each row (horizontal direction), and are connected by an electrical connection bridge 31 every other column (vertical direction) and in adjacent rows. The position of the electrical connection bridge 31 is shifted to have a substantially lattice pattern. Note that due to the electrical connection pattern of the thermoelectric element 1, the junction electrodes 30 are thinned out in the upper and lower ends of the figure, and the electrical connection bridge 31 also extends in the lateral direction. Yes.
[0016]
Here, as shown in FIG. 8, both the bridges 31 and 32 have a thickness equal to or less than half of the thickness of the bonding electrode 30 portion. Further, the mechanical connection bridge 32 is connected to the thermoelectric element 1 in the bonding electrode 30. The electrical connection bridge 31 is provided on the back side, the surface of the bonding electrode 30 and the surface of the mechanical connection dedicated bridge 32 are flush with each other, and the back surface of the bonding electrode 30 and the electrical connection bridge are provided. 31 is formed flush with the back surface. Furthermore, in addition to the thickness being reduced as described above, the mechanical connection dedicated bridge 32 is provided with a hole 33 or a groove to reduce its cross-sectional area.
[0017]
The electrical connection bridge 31 is for alternately connecting the P-type thermoelectric elements 1 and the N-type thermoelectric elements 1, whereas the mechanical connection bridge 32 is connected to the substrate 20. It is for maintaining the position of each bonding electrode 30 in the state before bonding, and is not involved in the electrical connection between the thermoelectric elements 1, and is bonded to the substrate 20 to be positioned at each bonding electrode 30. Is no longer necessary after the substrate 20 is held by the substrate 20, and therefore the mechanical connection dedicated bridge 32 is cut off after the metal pattern plate 3 is joined to the substrate 20. However, this cutting is not performed immediately after the substrate 20 is bonded, but is performed simultaneously with the cutting of the thermoelectric element material as will be described later.
[0018]
Further, the metal pattern plate 3 is integrally provided with an outer peripheral electrode 35 surrounding all the joined electrodes 30 integrally connected by the electrical connection bridge 31 and the mechanical connection dedicated bridge 32, and the external electrode is disposed outside the outer peripheral electrode 35. The connection terminal portion 36 and the sensor connection terminal portion 37 are integrally provided. The joining electrodes 30 and 30 located at the left and right ends of every other row and the outer peripheral electrode 35 are connected by a narrow mechanical connection bridge 32, and the joining electrode 30 at one corner is used for electrical connection. It is connected to the terminal portion 36 via the bridge 31 and the outer peripheral electrode 35.
[0019]
The bonding electrodes 30 are connected to each other in the horizontal direction by the mechanical connection bridge 32 as described above. However, in the other rows except the upper and lower rows, the mechanical connection is dedicated at the center in the left-right direction. Connection by the bridge 32 is not performed, and the block is partitioned into a plurality of blocks. This is to prevent warpage by absorbing thermal stress during bonding to the substrate 20 as in the case where the hole 33 is provided in the mechanical connection dedicated bridge 32 to reduce the cross-sectional area. In addition, the metal pattern plate 3 made of a conductive metal plate such as copper or a copper alloy is made of a single sheet so that the thermoelectric elements 1 can be joined without gaps by aligning the heights of all the joining electrodes 30. The metal plate is etched in the form shown in the figure, and both bridges 31 and 32 are formed by half etching from the front and back of the metal plate, but other processing methods such as softening by heating are used. It may be formed by pressing, punching, or by integrating the front and back punching patterns by heating and pressing in a deoxygenated state. In any case, it is preferable to provide Ni plating for preventing oxidation and Sn, Au plating for improving solder wettability.
[0020]
Then, as shown in FIG. 9, the metal pattern plate 3 is bonded and fixed to the surface of a ceramic substrate 20 having an insulating property such as alumina and beryllia and having a good thermal conductivity, thereby forming the electrode plate 2. At this time, the back surface of each bonding electrode 30, the back surface of the electrical connection bridge 31, the back surface of the outer peripheral electrode 35, and the back surfaces of the terminal portions 36 and 37 are contact-bonded to the substrate 20. It floats from the surface.
[0021]
  When the substrate 20 is alumina and the metal pattern plate 3 is a copper plate, a bonding method by forming a eutectic called a DBC method can be suitably used for the bonding. Since the metal pattern plate 3 becomes a high temperature of 1000 ° C. or higher at the time of bonding, the hardness is lowered and the thermoelectric element 1 is softly supported, so that the effect of stress relaxation on the thermoelectric element 1 can be expected. is there. By the way, since it is usually used with a strain of about 1%, the stress of copper at this time has been reduced to nearly half that before sintering, which is a material whose Young's modulus is practically ½.supportIs almost equal to In addition, since it becomes the above temperature, the difference of the thermal expansion coefficient of the metal pattern plate 3 and the board | substrate 20 will cause the board | substrate 20 to warp after joining, but presence of the above-mentioned stress relaxation part exists. This warpage is reduced. The joining of the metal pattern plate 3 and the substrate 20 is not limited to the DBC method, and may be joined by brazing or the like.
[0022]
Next, the rod-shaped P-type thermoelectric element material 1 a and the rod-shaped N-type thermoelectric element material 1 b are bonded to the bonding electrode 30 of one electrode plate 2. At this time, both thermoelectric element materials 1a and 1b are alternately bonded to each row of the bonding electrodes 30 as shown in FIG. Soldering is suitable for joining. For this purpose, it is preferable to form electrodes on the joining surfaces of the thermoelectric element materials 1a and 1b by plating or vapor deposition.
[0023]
FIG. 11 shows a jig 9 used for joining the thermoelectric element materials 1a and 1b. The long holes 93a and 93b can fit the thermoelectric element materials 1a and 1b at the same pitch as the pitch of the joining electrodes 30. The second plate 92 is superposed on the first plate 91, and the second plate 92 is provided with the long holes 94 at a double pitch. After the long hole 93a of the first plate 91 and the long hole 94 of the second plate 92 are overlapped, the P-type thermoelectric element material 1b is placed in the long hole 93a through the long hole 94, and then the second plate 92 is slid. Thus, the long hole 94 is overlapped with the long hole 93b, and the N-type thermoelectric element material 1b is accommodated in the long hole 93b in this state. In this way, both types of thermoelectric element materials 1a and 1b can be arranged at an accurate pitch that matches the interval between the bonding electrodes 30, and the P-type thermoelectric element material 1a and the N-type thermoelectric element material 1b You can avoid mistakes in the arrangement. Regarding the exclusion of misuse, it is also preferable to distinguish the two end surfaces of the rod-shaped thermoelectric element materials 1a and 1b with different marks.
[0024]
Instead of using the jig 9, a plate-like material is formed by integrating the thermoelectric element materials 1a and 1b alternately arranged at a required interval with an insulating material, and this is formed on one electrode plate. After joining on the second joining electrode 30, cutting may be performed. In this case, if the insulating material completely fills the space between the thermoelectric element materials 1a and 1b, the insulating material remains after cutting, and heat leakage due to the remaining insulating material tends to be a problem. Thus, it is good to use what integrated the insulating material 14 in the both ends of rod-shaped thermoelectric element material 1a, 1b, and the insulating material 14 will be removed after a cutting | disconnection.
[0025]
In addition, as shown in FIG. 13, the thermoelectric element materials 1 a and 1 b are used whose width X is the same as or slightly smaller than the width Y of the bonding electrode 30. This is to avoid the performance degradation by ensuring that the amount of heat generated in the thermoelectric element 1 can be released to the substrate 20 side through the bonding electrode 30. If the width X of the thermoelectric element 1 is smaller than the width of the bonding electrode Y, This is because thermal fatigue occurs in the portion of the thermoelectric element 1 that is not in contact with the bonding electrode 30 and element destruction occurs.
[0026]
The thermoelectric element material 1a and the thermoelectric element material 1b do not have to have the same width. Since the material characteristics of the P-type thermoelectric element 1 and the N-type thermoelectric element 1 cannot be perfectly matched, changing the widths of both thermoelectric element materials 1a and 1b is effective in obtaining the most efficient state. This is a measure. The two thermoelectric element materials 1a and 1b may have different heights. In this case, it is possible to respond by changing the height of the bonding electrode 30 depending on the row.
[0027]
By the way, although the cleavage surface 10 exists in the thermoelectric element materials 1a and 1b, when the rod-shaped thermoelectric element materials 1a and 1b are cut out, as shown in FIG.
It is assumed that the cleavage plane 10 is cut out so as to intersect the short direction of the thermoelectric element materials 1a and 1b. In cutting the thermoelectric element materials 1a and 1b, which will be described later, the cutting line C is made not to coincide with the cleavage plane 10. This is because the thermoelectric element 1 is a brittle material, and if it is cut in parallel with the cleavage plane 10, there is a very high possibility of chipping or cracking, leading to a decrease in yield. In addition, when two things shown in FIG. 14 are compared, as shown in FIG.14 (b), what the cleavage surface 10 runs in the longitudinal direction of the thermoelectric element materials 1a and 1b is preferable. This point will be described later. In the figure, reference numeral 11 denotes an electrode portion provided for bonding to the bonding electrode 30.
[0028]
When the joining of the thermoelectric element materials 1a and 1b to the one substrate 20 is completed, the rod-shaped thermoelectric element materials 1a and 1b are then cut. This cutting is performed using a grindstone 15 as shown in FIGS. 15 and 16, for example. In the embodiment shown here, the arrangement pattern of the bonding electrodes 30 is determined so that the cut portions of the thermoelectric element materials 1a and 1b are arranged in a straight line, and all the thermoelectric element materials 1a and 1b are collected together. If the cutting is performed in a straight line, the thermoelectric elements 1 remain on the bonding electrodes 30 in an individually separated state. Therefore, cutting is easy, and a plurality of grindstones 15 are used as shown in the illustrated example. The time required for the cutting work can be shortened by cutting the necessary portions together. Cutting the rod-shaped thermoelectric element materials 1a and 1b after joining them also makes it possible to align the cleaved surfaces of the thermoelectric elements 1, thereby reducing variations in durability.
[0029]
In this case, when the thermoelectric element members 1a and 1b are cut, as is apparent from FIG. 16, the mechanical connection bridge 32 is also cut at the same time. In other words, the thermoelectric element materials 1a and 1b are cut by cutting together with the mechanical connection dedicated bridge 32 located below the cut portion. Since the mechanical connection bridge 32 is in a state of floating from the substrate 20, and the outer peripheral electrode 35 and the electrical connection bridge 31 are thin and close to the substrate 20 side, the grindstone 15 is placed on the substrate 20. The above-described cutting can be performed without incurring a state in contact with the outer peripheral electrode 35 or a state in which the outer electrode 35 or the electrical connection bridges 31 on both ends are disconnected.
[0030]
In the rows at both ends, the bonding electrode 30 is thinned as described above, and in the other rows, the portion where the bonding electrode 30 is located is the portion where the thin electrical connection bridge 31 is present. Therefore, the thermoelectric element 1 remains only on the bonding electrode 30 by the above cutting, and the portion above the electrical connection bridge 31 of the thermoelectric element material 1a is removed.
[0031]
FIG. 17 shows the state after the cutting operation is performed in this manner, and FIG. 18 shows the cut portion shown by hatching. In the left-right direction of the bonding electrode 30 in the figure, the bonding electrodes 30 and 30 at the center of one row are connected by an electrical connection bridge 31 and are completely separated from each other. The connection is merely connected by an electrical connection bridge 31 for connection to the terminal portion 36. At the time of the cutting, the terminal portion 36 and the terminal portion 37 are separated and the outer peripheral electrode 35 and the terminal portion 37 are separated. In addition, the electrical connection bridge 31 provided in the terminal portions 36 and 37, that is, the thin portion near the back surface side of the metal pattern plate 3, is the terminal portion 36, 37 is provided in order to form a passing portion of the grindstone 15, and for this purpose, it is provided in the same arrangement as the mechanical connection dedicated bridge 32 to which the bonding electrode 30 is connected. Therefore, it is also a measure of the cutting line.
[0032]
After joining the thermoelectric element materials 1a and 1b, as shown in FIG. 19, only the thermoelectric element materials 1a and 1b may be cut first, and then the mechanical connection bridge 32 may be cut. In this case, it is possible to use cutting members suitable for cutting the thermoelectric element materials 1a and 1b and cutting the mechanical connection bridge 32, and by using cutting members having different widths, the width of the thermoelectric element 1 and the bonding electrode can be used. The width of 1 can be set to a preferable value.
[0033]
As shown in FIG. 20, the mechanical connection bridge 32 in the metal pattern plate 3 of the electrode plate 2 may be cut in advance, and then the thermoelectric element materials 1a and 1b may be joined and cut. Also in this case, the thermoelectric element materials 1a and 1b can be cut in a state where the cutting load of the mechanical connection dedicated bridge 32 is not applied, and the thermoelectric element materials 1a and 1b can be cut accurately. Of course, it is most preferable to cut the mechanical connection dedicated bridge 32 at the same time when the thermoelectric element members 1a and 1b are cut in terms of cutting work.
[0034]
Although the arrangement of the bonding electrode 30 and the pattern of electrical connection by the electrical connection bridge 31 are determined so that the cutting line is a straight line, various settings can be made as described later. It is not necessary that the cutting line be a straight line. However, making the cutting line straight is the most excellent in terms of cutting workability, and it is easy to cut a plurality of cutting lines simultaneously to reduce the time required for cutting. You will be able to respond. Cutting may be performed using a laser, a high-pressure water jet, or the like instead of the grindstone 15.
[0035]
For the other electrode plate 2, the same metal pattern plate 3 of the electrode plate 2 is bonded to the substrate 20, and the mechanical connection bridge 32 is cut. FIG. 21 shows the electrode plate 2 after the cutting. The cut location is the same as that cut by the one electrode plate 3.
When the cutting is completed, as shown in FIG. 22, after the rectangular cylindrical seal frame 4 is joined and attached to one electrode plate 2, the other electrode plate 2 is covered with the other electrode plate 2. The joining electrode 30 on the side and the thermoelectric element 1 are joined and the sealing frame 4 and the other electrode plate 2 are joined. As described above, the seal frame 4 is for sealing the portion where the thermoelectric element 1 is disposed, and the opening edge of the both ends forms a closed loop in the metal pattern plates 3 and 3 of the electrode plates 2 and 2, and the peripheral electrode 35 portion is machined. By being connected to each other electrically and electrically, the arrangement space of all the thermoelectric elements 1 is sealed together with the electrode plates 2 and 2. Since it joins to the outer peripheral electrode 35 part used as the closed loop, and the terminal part 36 is pulled out via the outer peripheral electrode 35, the power supply path to the thermoelectric element 1 can be ensured, maintaining the said sealing state. Is. In the case of being arranged on the inner side of the outer peripheral electrode 35, a groove is provided in the corresponding portion of the seal frame 4 for the remaining portion of the mechanical connection bridge 32 extending inward from the outer peripheral electrode 35 to avoid this.
[0036]
Here, as shown in FIG. 24, the seal frame 4 and the outer peripheral electrode 35 are joined together in advance with a metal such as copper, nickel, tin or the like at both ends of the opening edge provided for joining with the outer peripheral electrode 35 in the non-metallic seal frame 4. The film 44 is formed by plating or thermal spraying, and is joined to the outer peripheral electrode 35 by soldering 48 or brazing. This is to improve the moisture resistance by avoiding the use of an adhesive that easily allows moisture to enter in the long term. Note that the metal films 44 are individually provided at the opening edges of both ends so as not to be electrically connected because each outer peripheral electrode 35 is connected to the terminal portion 36. Further, the seal frame 4 has a cross-sectional shape as shown in FIGS. 23 and 24 having a portion directly in contact with the electrode plate 2 inside the outer peripheral electrode 35, thereby regulating the interval between the electrode plates 2 and 2. It is preferable to be able to In this case, since the soldering or brazing portion can be seen, it is easy to determine whether it is good or bad. In order to prevent moisture from entering from a portion where the metal film 44 is not provided or a crack at the time of solder fatigue, it is preferable to use the adhesive 49 in combination. The seal frame 4 here bears a load in the opposing direction of the electrode plates 2 and 2.
[0037]
The joining of the joining electrode 30 on the other electrode plate 2 side and the thermoelectric element 1 is performed simultaneously with the joining of the seal frame 4 and the other electrode plate 2, but this is also preferable in the following points. . That is, if the gap between the electrode plates 2 and 2 is regulated by the seal frame 4, the variation in the height of the thermoelectric element 1 is adjusted by the thickness of the soldering solder, and the load applied to the electrode plate 2 is sealed. This is because it is shared by the rigidity of the frame 4 and the rigidity of the thermoelectric element 1, and the load applied to the thermoelectric element 1 can be reduced. However, if the thickness of the seal frame 4 is increased in order to increase the rigidity of the seal frame 4, heat leakage also increases. Therefore, in order to avoid this, it is important to increase only the necessary strength portion. The thicker corners as shown, and the central portion provided with the column 40 for improving the load resistance are effective in this respect.
[0038]
Now, in the thermoelectric module configured in this way, all the thermoelectric elements 1 are electrically connected in series by the joining electrode 30 and the electrical connection bridge 31 in the metal pattern plate 3 of both electrode plates 2 and 2. In addition, a set of the P-type thermoelectric element 1 and the N-type thermoelectric element 1 is thermally connected in parallel, and is connected through a terminal portion 36 on one electrode plate 2 side and a terminal portion 36 on the other electrode plate 2 side. Connected to power.
[0039]
Here, the thermoelectric elements 1 are thinned out in the upper row and the lower row so that both electrode plates 2 and 2 can use the same metal pattern plate 3 and at the same time a P-type thermoelectric device. This is to prevent the ones or the N-type thermoelectric elements 1 from being connected continuously. However, at the center of the row at one end, two P-type thermoelectric elements 1 and 1 are connected continuously. Such continuation of the same type of thermoelectric element 1 causes a slight decrease in efficiency, but the purpose is to do this in the case where the number of rows of the junction electrode 30 and the thermoelectric element 1 is an odd number and the same as described above. The metal pattern plate 3 can be used for both electrode plates 2 and 2 and the metal pattern plate 3 can be divided into two blocks on the left and right sides for the purpose of relaxing the thermal stress. is there. It may not be thinned out at all from the point of impact load.
[0040]
The reason why the number of rows of the bonding electrode 30 and the thermoelectric element 1 is an odd number is to arrange the thermoelectric elements 1 of the same type in the rows at both ends. As described above, a part of the thermoelectric element material is removed in the rows at both ends. However, since it is the same type, it is easy to deal with recycling of the removed material. And when it is set as an odd-numbered row | line, it is good to arrange the P-type thermoelectric element 1 in the row | line | column of both ends. When the P-type thermoelectric element 1 and the N-type thermoelectric element 1 are compared, the P-type thermoelectric element 1 has better characteristics, is easier to manage, and is less expensive. Accordingly, the N-type thermoelectric element material 1b can be reduced by one than the P-type thermoelectric element material 1a, and the thermoelectric element 1 is thinned out in spite of the use of the rod-shaped thermoelectric element material 1a in both ends as described above. Therefore, it is preferable to arrange P-types in the rows at both ends.
[0041]
The electrode plate 2 is not limited to one having a ceramic substrate 20 or one having the metal pattern plate 3. Even if the metal pattern plate 3 shown in FIGS. 4 to 7 is used, the gap between the bonding electrodes 30 is filled with an insulating resin 25 having good thermal characteristics by injection molding or casting, as shown in FIGS. What is shown can be used as the electrode plate 2. In this case, the insulating resin 25 is molded in a state where the surface of the metal pattern plate 3 is once oxidized, and thereafter, the oxide film on the surface to which the thermoelectric element materials 1a and 1b of the metal pattern plate 3 are joined and Ni are removed. Processing should be done. The seal frame 4 can also be formed integrally.
[0042]
In this type of electrode plate 2, the back surface of the bonding electrode 30, the electrical connection bridge 31, or the outer peripheral electrode 35 is directly connected to the heat dissipation member or the heat absorbing member by making the back surface flush with the concave surface of the bonding electrode 30. Since it can be brought into contact with the member, the heat dissipation characteristic is better than that of the ceramic type, and for this reason, a favorable result can be obtained when used on the heat dissipation side. Of course, it may be used on the heat absorption side, and the thermoelectric module M may be composed of two electrode plates 2 and 2 of this type and the thermoelectric element 1.
[0043]
On the front side of the metal pattern plate 2, the insulating resin 25 may be slightly higher than the surface of the bonding electrode 30. It is possible to prevent a short circuit with a different electrode during soldering. When the electrode plate 2 shown in FIGS. 26 and 27 is used, the cutting of the rod-shaped thermoelectric element materials 1a and 1b and the dedicated bridge 32 for mechanical connection of the metal pattern plate 3 is performed by cutting the insulating resin 25 at the same time. Do.
[0044]
In the above-described type of metal pattern plate 3, it is preferable that the ratio of the insulating resin 25 to the metal pattern plate 3 is substantially the same on the front and back in terms of preventing warpage. A material having chemical bonding properties and a thermal expansion coefficient similar to that of the metal pattern plate 3 is preferable. This is because the permeation of water vapor can be prevented and a gap is hardly formed. Furthermore, it is preferable that the material has a Young's modulus sufficiently lower than that of the metal pattern plate 3. In order to satisfy these conditions, if the metal pattern plate 3 is made of copper or copper alloy, epoxy resin, especially SiO₂Those to which is added are suitable.
[0045]
Examples of circuit patterns for connecting the thermoelectric elements 1 and 1 by the joining electrodes 30 and 30 of the two electrode plates 2 and 2 are shown in FIGS. FIG. 28A shows a circuit pattern when the metal pattern plate 3 is used. As is apparent from the figure, various patterns including the arrangement of the terminal portions 36 can be configured. A pattern as shown in FIG. 30 is also possible. In FIG. 30, connection by two lines indicates connection by one electrode plate 2, and connection by one line indicates connection by the other electrode plate 2.
[0046]
The thermoelectric element 1 containing Bi-Te-Sb-Se as a main component is bonded to the bonding electrode 30 by soldering as described above. However, as shown in FIG. It is preferable to provide the electrode 11 by providing the layer 17 and the Ni layer 18 as a barrier layer from the viewpoint of preventing diffusion. In FIG. 31, a layer made of a material selected from Sn, Bi, Ag, and Au, for example, a Sn + Bi layer 19 is further provided on the Ni layer 18. This layer 19 is for preventing the oxidation of the Ni layer 18 and improving the solderability. It is desirable that the Ni layer 18 has a thickness of 1 μm or more and the Mo layer 17 is thinner than this. For example, the Mo layer 17 is 0.2 μm, the Ni layer 18 is 2 μm, and the Sn + Bi layer 19 is 2 μm.
[0047]
By the way, the cleavage surface 10 exists in the thermoelectric element 1 as described above, but the cleavage surface 10 in the thermoelectric element 1 is used when the thermoelectric module is energized to absorb heat on one side and dissipate heat on one side. Most preferably, the cleavage planes 10 are aligned in the direction of expansion and contraction caused by the difference in heat between both sides. That is, it is assumed to be shown in FIG. The thermoelectric module expands and contracts in the direction indicated by the arrow in the figure, which is the connection direction of the P-type thermoelectric element 1 and the N-type thermoelectric element 1, but when the cleavage planes 10 are aligned in this direction, This is because the thermoelectric element 1 absorbs the stress due to the expansion and contraction due to a slight deviation in the cleavage plane 10. As a result, the allowable range of displacement due to expansion and contraction is increased, and the thermoelectric element 1 can be prevented from being damaged by stress.
[0048]
And it can obtain easily in the thermoelectric module concerning this invention that the cleavage surface 10 is arranged in this way. That is, since the rod-shaped thermoelectric element materials 1a and 1b are arranged and cut in a direction orthogonal to the electric connection direction by the electric connection bridge 31, the thermoelectric element materials 1a and 1b are shown in FIG. As shown in FIG. 12B, the electrode 11 for bonding to the bonding electrode 30 is provided on the surface perpendicular to the cleavage surface 10, that is, the upper and lower surfaces in FIG. Thus, what is shown in FIG. 32 (a) can be obtained. Incidentally, the arrangement of the cleavage planes 10 as shown in FIG. 32 (b) is fragile when subjected to the stress due to the expansion and contraction, and the arrangement of the cleavage planes 10 as shown in FIG. It will be a thing.
[0049]
Furthermore, in the above example, as the thermoelectric element materials 1a and 1b, the one extending over the entire length of the row of the bonding electrodes 30 is used, but as shown in FIG. 33, a plurality of thermoelectric element materials 1a and 1b are arranged for one row. You may make it use. Since the thermoelectric element materials 1a and 1b having a short length can be used, the material utilization efficiency of the thermoelectric element materials 1a and 1b is increased, and the thermoelectric element is warped by the electrode plate 2 after being bonded to the bonding electrode 30. The stress on the element materials 1a and 1b can be reduced.
[0050]
A plurality of electrical connection bridges 31 for connecting the bonding electrode 30 and the outer peripheral electrode 35 in the metal pattern plate 3 may be provided. The different joining electrodes 30 are connected to the outer peripheral electrode 35 by the electrical connection bridge 31. Of course, in the end, the other electrical connection bridges 31 are cut off so that only one of the junction electrodes 31 is connected to the outer peripheral electrode 35 by any one of the electrical connection bridges 31. Depending on which electrical connection bridge 31 is left, even if the same metal pattern plate 3 is used, one having a different number of thermoelectric elements 1 mounted, that is, one having a different performance of the thermoelectric module can be selected and obtained.
[0051]
However, when the number of connection points between the bonding electrode 30 and the outer peripheral electrode 35 by the electrical connection bridge 31 is increased, warpage is likely to occur during bonding to the substrate 20, so that the metal shown in FIGS. 4 to 7 is used. In the pattern plate 3, extended pieces are extended from several joint electrodes 30 toward the outer peripheral electrode 35, and the joint connected to the terminal portion 36 through the outer peripheral electrode 35 depending on which extension piece is connected to the outer peripheral electrode 35. The electrode 30 (the bonding electrode 30 that becomes one end of the circuit pattern) can be selected.
[0052]
As shown in FIG. 34 or FIG. 35, the thermoelectric module M as described above is provided with a heat absorbing member 5 on the outer surface of the electrode plate 2 on one side and a heat radiating member 6 on the outer surface of the electrode plate 2 on the other side. Is done. At this time, for thermal coupling between the electrode plate 2 and the heat absorbing member 5 or the heat radiating member 6, the thermoelectric module M is sandwiched between the heat absorbing member 5 and the heat radiating member 6 and a required load is applied to the thermal coupling surface. Although it is added, it is preferable to apply the load by a spring 7 such as a coil spring or a disc spring as shown in the figure. In the figure, reference numeral 70 denotes a screw for connecting the heat absorbing member 5 and the heat radiating member 6, and the spring 7 is arranged between the head of the screw 70 and the member 5 through which the screw 70 is inserted. The screws 70 and 71 are made of a material having low thermal conductivity.
[0053]
FIG. 36 shows a specific heat absorbing member 5 and heat radiating member 6. The heat radiating member 6 has a large number of heat radiating fins 60. In the figure, reference numeral 71 denotes a screw for connecting the members 5 and 6 and also for mounting the block. Although the area of the contact surface with the thermoelectric module M of the heat absorption member 5 and the heat radiating member 6 is made smaller than the surface area of the thermoelectric module M, this is for reducing a heat leak.
[0054]
The heat-absorbing member 5 and the heat-dissipating member 6 are made of aluminum or an alloy thereof, which has high thermal conductivity and is easy to process, and an alumite layer is provided on the surface for corrosion prevention and insulation. You may form with what put carbon fiber in aluminum, or a copper alloy. Since the surface of the heat-absorbing member 5 is used as a mounting surface for a member to be cooled, the heads of the screws 70 and 71 do not protrude from this surface.
[0055]
Here, the thermal resistance is reduced by interposing silicon grease having a thickness of a few μm on the contact surface between the thermoelectric module M and the heat absorbing member 5 and the contact surface between the thermoelectric module M and the heat radiating member 6. This thermal resistance decreases as the load increases, and is substantially stabilized at a load of 1000 to 1500 N as shown in FIG. In the figure, ΔT is the temperature difference between the electrodes. On the other hand, the durability of the thermoelectric element 1 itself decreases as the load increases as shown in FIG. 38, and the shearing force generated by this temperature difference acts as the interelectrode temperature difference ΔT increases. The durability decreases. In order to improve the performance by reducing the contact thermal resistance, it is only necessary to increase the mounting load. However, in the thermoelectric element 1 used for consumer use, the reliability decreases when the mounting load is increased. .
Due to the above characteristics, the mounting load is generally set to an optimum load of about 1000 N, but it is difficult to set the mounting load to this value by the tightening force of the screw 70. . However, since the mounting load is set by the spring 7 as described above, it is easy to set the optimum load. In addition, since the thermoelectric module M used here reduces the load applied to the thermoelectric element 1 by the mounting of the seal frame 4 to the mounting load, the load sharing ratio of the seal frame 4 is halved. Then, even if the mounting load is set to 1000 to 1700 N in order to reduce the thermal resistance and improve the performance, the load applied to the thermoelectric element 1 is 500 to 850 N, and high durability can be obtained. FIG. 39 shows the relationship between the deformation amount of the thermoelectric element 1 and the mounting load when the seal frame 4 is present and when it is not present (the load sharing ratio of the seal frame 4 is ½).
[0056]
In order to further reduce the mounting load applied to the thermoelectric element 1, a load sharing frame 46 may be further provided on the outer periphery of the seal frame 4 as shown in FIG. FIG. 41 shows a structure in which an annular metal portion 39 for fixing the frame 46 is further provided outside the outer peripheral electrode 35. The frame 46 may be fixed in the same manner as in the case of the seal frame 4, but may be fixed with an adhesive.
[0057]
Further, in the thermoelectric module M used here, the bonding electrode 30 to which the thermoelectric element 1 is bonded is formed of thick copper or copper alloy, and the shear stress applied to the thermoelectric element 1 itself is reduced. In addition, it is highly durable. The reduction of the shear stress can be reduced by solder or the like that joins the joining electrode 30 and the thermoelectric element 1, but is difficult to manage. However, in this case, since it can be managed by the height of the bonding electrode 30, the required performance can be surely exhibited. As shown in FIG. 42, if one or more grooves 33 are provided on the surface of the bonding electrode 30 to reduce the rigidity, the shear stress can be further reduced. The arrows in the figure indicate the direction of expansion and contraction, similar to the arrows shown in FIG. 32 (a), and the grooves 33 are formed by cutting in a direction that is effective in reducing shear stress due to the expansion and contraction.
[0058]
FIG. 43 shows another example of the seal frame 4. Here, the seal frame 4 is integrally provided with a thin plate piece 47 for maintaining electrical insulation between the thermoelectric elements 1. The joining of one surface of the thermoelectric element 1 and the joining electrode 30 of the one electrode plate 2 is performed in a state where the thin plate pieces 47 are partitioned between the thermoelectric elements 1 in the state shown in FIG. Therefore, it is possible to prevent a short circuit due to soldering for the purpose of improving the production yield of the thermoelectric module.
[0059]
It is possible to deal with the case where the thermoelectric module M is configured in multiple stages. 44 uses the metal pattern plate 3 bonded to the upper and lower surfaces of the substrate 20 as the central electrode plate 2 and bonds the thermoelectric element materials 1a and 1b to the upper and lower surfaces of the electrode plate 2 and cuts them. The other two electrode plates 2 and 2 are stacked on the upper and lower sides of the central electrode plate 2. The thermoelectric element materials 1a and 1b are bonded to the bonding electrodes 30 of the metal pattern plates 3 of the upper and lower electrode plates 2, and after the thermoelectric element materials 1a and 1b are cut, the metal pattern plates 3 and 3 are formed on the upper and lower surfaces. Of course, the joined central electrode plates 2 may be joined together. Since the heat absorption side reduces the number of thermoelectric elements 1, the same metal as shown in FIGS. 4 to 7 bonded to the lower surface of the central substrate 20 and the upper surface of the lower substrate 20 is again used here. A metal pattern plate 3 that is approximately half the size of the pattern plate 3 is bonded to the lower surface of the upper substrate 20 and the upper surface of the central substrate 20.
[0060]
As the electrode plate 2 having the bonding electrode 30, the metal pattern plate 3 provided with the bonding electrode 30 is bonded to the substrate 20, or the insulating resin 25 is embedded in the gap between the metal pattern plates 3. A material that does not use the metal pattern plate 3, for example, a printed circuit board on which the electrode pattern of the bonding electrode 30 is provided, can also be used as the electrode plate 2. The electrode pattern here may be formed by performing metal spraying on the surface of the substrate 20 in addition to etching. When such an electrode plate 2 is used, the mechanical connection dedicated bridge 32 is not necessary. However, it is difficult to take a sufficient thickness of the bonding electrode 30, and it becomes difficult to reduce the thermal stress generated when the thermoelectric element 1 is energized using the thickness and softness of the bonding electrode 30.
[0061]
In addition, when the electrode plate 2 is formed by bonding the metal pattern plate 3 including the bonding electrode 30 to the substrate 20 or filling the gap between the metal pattern plates 3 with the insulating resin 25, the substrate 20 and the insulating resin The heat absorbing / dissipating members 5, 6 may be integrated so that the electrode plate 2 also serves as the heat absorbing / dissipating members 5, 6. That is, the metal pattern plate 3 is joined to the heat absorbing member 5 and the heat radiating member 6. The number of parts can be reduced.
[0062]
【The invention's effect】
  As described above, the present inventionObtained by the manufacturing method according toIn the thermoelectric module, the thermoelectric elements are arranged on each bonding electrode by cutting a thermoelectric element material attached across the plurality of bonding electrodes of the electrode plate. In addition, a good performance can be obtained because there is no insulating material between the thermoelectric elements that causes heat leakage.
[0063]
  And in order to manufacture with the above manufacturing method,After attaching the thermoelectric element material straddling the plurality of bonding electrodes on the electrode plate on which the plurality of bonding electrodes are provided in the required arrangement, the thermoelectric element material is cut to connect the thermoelectric elements on each bonding electrode. Separately, after that, another electrode plate provided with a plurality of bonding electrodes in a required arrangement is attached to the other surface side of the thermoelectric element, and individually used to use the thermoelectric element material straddling the plurality of bonding electrodes. Therefore, the thermoelectric elements are aligned at a required interval by joining the thermoelectric elements to the bonding electrodes of the electrode plate, and in this state, the thermoelectric elements are aligned. In order to cut the material, the heat-resistant insulating material that causes heat leakage (thermal short circuit) as in the conventional example can be manufactured without remaining between the thermoelectric elements, and has good performance. Easy and reliable It can be. In addition, since the joining electrodes that are connected to the thermoelectric elements and are responsible for electrical connection between the thermoelectric elements are provided on the electrode plate, it is easy to manage accuracy, flatness, and the like.
[0064]
  The machine is composed of a single conductive metal plate having a large number of bonding electrodes to which thermoelectric elements are bonded, and the bonding electrodes arranged in a predetermined pattern are electrically connected to the adjacent bonding electrodes and the machine to be cut off. A metal pattern plate that is connected by at least one of the dedicated connection bridges and in which all the junction electrodes are integrated by the bridge is used as an electrode plate.From thatSince the positional accuracy of the bonding electrode can be further increased and the handling thereof is facilitated, a higher performance can be obtained more easily.
  In addition, the mechanical connection bridge in the metal pattern plate is cut at the same time when the thermoelectric element material is cut, so that the labor of cutting work can be reduced.
  In addition, if a metal pattern plate with a thermal stress absorption part is used, the thermoelectric element is affected by the heat stress caused by the difference in heat between the thermoelectric element materials and the temperature difference between the heat absorption side and the heat dissipation side when the thermoelectric element is energized. The possibility that the element is destroyed can be reduced, and the yield can be improved and the durability can be obtained.
[Brief description of the drawings]
FIG. 1 is a cutaway plan view showing an example of an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the same.
FIG. 3 is a transverse sectional view of the above.
FIG. 4 is a plan view of a metal pattern plate used for the above.
FIG. 5 is a perspective view of a metal pattern plate used for the above.
FIG. 6 is a rear view of the metal pattern plate used in the above.
FIG. 7 is a perspective view showing the back side of the metal pattern plate used in the above.
FIG. 8 shows a cross section of the metal pattern plate used in the above, wherein (a) is a transverse sectional view and (b) is a longitudinal sectional view.
FIG. 9 is a perspective view showing a state before processing of the electrode plate used in the above.
FIG. 10 is a perspective view after joining the thermoelectric element material of the electrode plate used in the above.
FIG. 11 is a cross-sectional view of a jig used for disposing the thermoelectric element material same as above.
FIG. 12 is a perspective view of another example of the thermoelectric element material same as above.
FIG. 13 is a cross-sectional view of the junction electrode and the thermoelectric element material.
14 (a) and 14 (b) are perspective views showing a cleavage plane of a thermoelectric element material used in the above.
FIG. 15 is a perspective view showing the cutting of the thermoelectric element material same as above.
FIG. 16 is a cross-sectional view showing cutting of the thermoelectric element material same as above.
FIG. 17 is a perspective view showing a state after cutting the thermoelectric element material.
FIG. 18 is a plan view showing a cut portion of the thermoelectric element material.
FIGS. 19A and 19B show another example of the above cutting, and FIGS. 19A and 19B are cross-sectional views.
FIG. 20 shows still another example of the above-described cutting, and (a) and (b) are cross-sectional views.
FIG. 21 is a perspective view of the other electrode plate.
FIG. 22 is a perspective view showing a mounting state of the above-described seal frame.
FIGS. 23A and 23B show the above-described seal frame, in which FIG. 23A is a perspective view and FIG. 23B is a cross-sectional view.
FIG. 24 is an enlarged cross-sectional view showing a fixing part of the above-described seal frame.
FIG. 25 is a perspective view showing another example of the above-described seal frame.
FIG. 26 is a perspective view of another electrode plate.
FIG. 27 is a perspective view showing the back side of the electrode plate.
FIGS. 28A to 28F are explanatory diagrams of circuit pattern examples. FIGS.
29A to 29F are explanatory diagrams of circuit pattern examples.
FIG. 30 is an explanatory diagram of another circuit pattern.
FIG. 31 is a cross-sectional view of the thermoelectric element material same as above.
FIG. 32 shows an example of the direction of the cleavage plane of the thermoelectric element same as above, and (a), (b) and (c) are perspective views, respectively.
FIG. 33 is a perspective view showing another example of joining a thermoelectric element material to an electrode plate.
FIG. 34 is a cross-sectional view showing a mounting example of a heat absorbing member and a heat radiating member.
FIG. 35 is a cross-sectional view showing another mounting example of the heat absorbing member and the heat radiating member.
FIG. 36 is a cross-sectional view showing another mounting example of the heat absorbing member and the heat radiating member.
FIG. 37 is an explanatory diagram showing characteristics of thermoelectric elements.
FIG. 38 is an explanatory diagram showing another characteristic of the thermoelectric element.
FIG. 39 is an explanatory diagram showing characteristics of the thermoelectric module depending on the presence or absence of a seal frame.
FIG. 40 is a longitudinal sectional view showing another example of the embodiment.
FIG. 41 is a perspective view of the electrode plate.
42A and 42B show another example of the bonding electrode, in which FIG. 42A is a cross-sectional view, and FIG. 42B is a perspective view.
43A and 43B show another example of a seal frame, where FIG. 43A is a perspective view and FIG. 43B is a cross-sectional view.
FIG. 44 is an exploded perspective view of a multistage module.
[Explanation of symbols]
M thermoelectric module
1 Thermoelectric element
2 Electrode plate
30 bonding electrodes
31 Bridge for electrical connection
32 Dedicated bridge for mechanical connection

Claims (4)

Two electrode plates comprising a thermoelectric element and an electrode plate in which a large number of bonding electrodes to which the thermoelectric elements are bonded are arranged in a required pattern and the bonding electrodes are electrically connected to adjacent bonding electrodes A method of manufacturing a thermoelectric module in which a P-type thermoelectric element and an N-type thermoelectric element are joined to a joining electrode and electrically connected alternately ,
A machine composed of a single conductive metal plate provided with a large number of bonding electrodes to which thermoelectric elements are bonded, and a bonding electrode arranged in a required pattern adjacent to the bonding electrode and an object to be cut A metal pattern plate that is connected by at least one of the dedicated connection bridges and all the joined electrodes are integrated by the bridge, as the electrode plate,
After attaching a P-type thermoelectric element material and N-type thermoelectric element material straddling a plurality of bonding electrodes on one electrode plate, each thermoelectric element material is cut to separate the thermoelectric elements on each bonding electrode. At the same time, the mechanical connection bridge is cut, and then the other electrode plate that has been cut in advance is attached to the thermoelectric element . 2. The method of manufacturing a thermoelectric module according to claim 1, wherein a metal pattern plate having a thermal stress absorbing portion is used . 3. The method of manufacturing a thermoelectric module according to claim 1, wherein a bridge dedicated to mechanical connection is used as the electrode plate that is floated from the substrate . The thermoelectric module according to any one of claims 1 to 3, wherein a bridge dedicated to electrical connection is used as an electrode plate that is thinner than the bonding electrode and is displaced toward the substrate. Method.

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