JP2014082403A - Thermoelectric conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoelectric conversion device capable of enhancing intensity while facilitating miniaturization.SOLUTION: A thin-walled copper plate is drawn to form a lower side and an upper side cases having recess parts on their central parts and flange like outward flange parts around them. A plurality of dice like thermoelectric elements are arranged longitudinally and horizontally to form a rectangular thermoelectric module which are integrally formed with each other by an adhesive containing insulation particles, and the thermoelectric module is received in both opposing recess parts of both cases. Belt-like terminals connecting each of thermoelectric elements in series are provided on bottom surfaces of each recess parts, and lead lines are connected to dummy elements at two corners of thermoelectric modules. It is possible to downsize the whole, to reduce an area of bottom surface of the recess part provided on the case for receiving a plurality of thermoelectric elements and conductive relay members, and to enhance strength of the whole case because a space is not caused in a part where thermoelectric elements and conductive relay members are arranged in the case.

Description

  The present invention relates to a thermoelectric conversion device in which a plurality of thermoelectric conversion elements are arranged in parallel in a case.

  Conventionally, as a thermoelectric conversion device using a thermoelectric conversion element, a cooling device that cools an object by using a thermoelectric effect such as Thomson effect, Peltier effect, Seebeck effect, etc., or power generation using a temperature difference There are known power generators that can be used. For example, a plurality of thermoelectric elements are provided between the heat dissipation side insulating substrate and the heat absorption side insulating substrate, and a frame is provided between the lid provided on the heat absorption side substrate and the heat dissipation side substrate, and the sealed box structure (For example, refer to Patent Document 1).

JP-A-2005-277206

  In the thermoelectric conversion device as described above, a plurality of thermoelectric elements are arranged vertically and horizontally, and the adjacent thermoelectric elements are sequentially connected in series by the wiring pattern provided on the upper and lower substrates from the thermoelectric elements at one end, and the thermoelectric elements at both ends are connected. Each lead wire is connected.

  In the said patent document 1, it is necessary to insulate between the thermoelectric elements which adjoin, and the wall-shaped insulation member which processed the alumina material into the grid | lattice form is provided. Due to the structure in which the thermoelectric elements are arranged in each grid part, the wall-shaped part forming the grid has a thickness, and if the grid part is widened to make it easier to insert, the interval between adjacent thermoelectric elements becomes large, and the thermoelectric elements There is a problem in that the area of the planar portion corresponding to the element is increased, the entire apparatus is enlarged, and the strength of the planar portion is reduced.

  The present invention has been devised to solve such problems of the prior art, and a main object of the present invention is to provide a thermoelectric conversion device that can be reduced in size and increased in strength.

  The thermoelectric conversion device of the present invention includes a plurality of thermoelectric elements, first and second case division bodies sandwiching the plurality of thermoelectric elements, and a plurality of connection terminals for connecting the plurality of thermoelectric elements in series. A thermoelectric conversion device comprising: a plurality of thermoelectric elements connected to both ends of the series connection and electrically connected for external connection sandwiched between the first and second case divided bodies together with the plurality of thermoelectric elements. It is set as the structure which has a sex relay member.

  According to the present invention, since the conductive relay member is sandwiched together with the plurality of thermoelectric elements between the first and second case division bodies, the strength of the portion where the conductive relay member is disposed (the portion that becomes the plane of the case) And the strength of the entire case can be increased. In the case of a structure in which the conductive relay member is not sandwiched, a space is generated in the portion, and there is a possibility that the corresponding portion of the case is recessed. However, the structure described above causes the thermoelectric element and the conductive relay member in the case to be disposed. Since no space is generated, the strength of the entire case is increased.

Whole perspective view which shows an example of the external appearance of the thermoelectric conversion apparatus 1 by this invention An exploded perspective view showing the configuration of the thermoelectric converter (A)-(c) is a figure which shows an example of the process of a thermoelectric module Sectional drawing which shows the part fractured | ruptured along the arrow IV-IV line of FIG. The principal part expanded sectional view which shows the part fractured | ruptured along the arrow VV line of FIG. The principal part expanded sectional view which shows the surface shape of the recessed part of an upper case (A)-(e) is a figure which respectively shows the 1st-5th modification corresponding to FIG. The principal part expansion perspective view which shows the wiring point of a dummy member and a thermoelectric element

  A first invention made to solve the above-described problem is to connect a plurality of thermoelectric elements, first and second case division bodies sandwiching the plurality of thermoelectric elements, and the plurality of thermoelectric elements in series. A plurality of connection terminals, connected to both ends of the series connection of the plurality of thermoelectric elements, and sandwiched between the first and second case divided bodies together with the plurality of thermoelectric elements It is set as the structure which has the electroconductive relay member for external connection made.

  According to this, since the conductive relay member is sandwiched with the plurality of thermoelectric elements between the first and second case division bodies, the strength of the portion where the conductive relay member is disposed (the portion that becomes the plane of the case) is ensured. And the strength of the entire case can be increased. In the case of a structure in which the conductive relay member is not sandwiched, a space is generated in the portion, and there is a possibility that the corresponding portion of the case is recessed. However, the structure described above causes the thermoelectric element and the conductive relay member in the case to be disposed. Since no space is generated, the strength of the entire case is increased.

  Further, according to a second aspect, in the first aspect, the thermoelectric element and the conductive relay member are formed in the same shape as each other, and are arranged in a plurality of rows and columns to form a rectangular outer shape in plan view. It is set as the structure arrange | positioned.

  According to this, since the thermoelectric element and the conductive relay member have the same shape, they can be arranged in a plurality of rows and columns to form a rectangular shape as a whole, for example, conductive at two corners of a rectangle. And a concave portion having a rectangular flat bottom surface is formed in at least one of the first and second cases, and the bottom surface of the concave portion can be connected to a pair of external connection lead wires. By placing the thermoelectric element and the conductive relay member on the entire surface of the case, when they are sandwiched between the first and second cases, a space is created between the bottom surface of the concave portion of both cases and the opposing surface. Therefore, the strength of the entire bottom surface of the recess can be increased.

  According to a third aspect of the present invention, in the first or second aspect, the plurality of thermoelectric elements are bonded and integrated with each other by an insulating adhesive filled between adjacent ones. To do.

  According to this, by adhering adjacent thermoelectric elements and integrating a plurality of thermoelectric elements without substantial gaps, the range in which the plurality of thermoelectric elements are arranged becomes narrower, and the case for receiving a plurality of thermoelectric elements can be made compact. Can be Therefore, the strength of the case is increased, the case can be formed of a thin metal plate material, and the entire apparatus can be reduced in size and weight.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the insulating adhesive is obtained by mixing insulating particles in an adhesive.

  According to this, as an insulating adhesive, for example, an insulating particle having a particle size of about several μm to 20 μm is made of an epoxy resin adhesive or a thermosetting adhesive by an insulating material having high heat resistance such as a fluororesin such as PTFE. By using the adhesive mixed in, etc., the gap between the thermoelectric elements can be narrowed to the extent of the particle size of the insulating material, and the miniaturization can be further promoted.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall perspective view showing an example of the appearance of a thermoelectric conversion device 1 according to the present invention. As shown in the figure, the thermoelectric conversion device 1 includes a rectangular flat case 2 and two external connection lead wires 3 a and 3 b extending outward from one side of the rectangular shape of the case 2. Have. The lead wires 3a and 3b are connected to an external control device (not shown).

  FIG. 2 is an exploded perspective view showing the configuration of the thermoelectric conversion device 1 of FIG. As shown in the figure, the case 2 includes a lower case 4 and an upper case 5. Between the lower case 4 and the upper case 5, a thermoelectric module 6 is received in which a plurality of thermoelectric elements are aligned in a plurality of rows and columns to form a rectangular flat plate as a whole. The thermoelectric module 6 is formed in the same rectangular parallelepiped shape, and includes a thermoelectric element 6a made of a P-type semiconductor and a thermoelectric element 6b made of an N-type semiconductor. The thermoelectric elements 6a and 6b are alternately arranged in a plurality of vertical and horizontal rows so as to form a rectangular plate as a whole. The portions corresponding to the two corners have the same shape as the thermoelectric elements 6a and 6b. For example, a dummy member 7 made of conductive metal is disposed as a conductive relay member. Lead wires 3a and 3b are connected to each dummy member 7 by, for example, soldering.

  FIG. 3 is a diagram illustrating an example of a processing process of the thermoelectric module 6. First, as shown in FIG. 3A, a P-type semiconductor ingot 11 and an N-type semiconductor ingot 12 are respectively sliced into plate-like members 11a and 12a having the same thickness as indicated by broken lines. These are arranged alternately, and an adhesive 13 as an insulating adhesive is applied between the plate-like members 11a and 12a to form a rectangular parallelepiped laminate 14.

  Next, as shown in FIG. 3 (b), the laminated body 14 is sliced in the direction of lamination, and P-type and N-type square bars 11b and 12b are alternately laminated in parallel. The laminated body 15 is formed, and the plate-like laminated body 15 is cut in the stacking direction of the bars 11b and 12b as indicated by broken lines in the figure. As a result, as shown in FIG. 3C, a stacked bar 16 in which P-type and N-type are alternately arranged in series is formed, and the stacked bar 16 is placed so that the P-type and N-type are not adjacent to each other. Line up. Thereafter, the laminated bars 16 are bonded to each other with the adhesive 13 to form a plate-like temporary thermoelectric module 17 in which the respective cubic thermoelectric elements 6a and 6b are alternately arranged in the vertical and horizontal directions.

  Then, as shown in FIG. 3C, the thermoelectric elements 6a and 6b on both ends of one side of the temporary thermoelectric module 17 are respectively replaced with dummy members 7, and the thermoelectric module 6 is formed. The stacked bar 16 is formed by arranging the thermoelectric elements 6a and 6b so that different thermoelectric elements 6a and 6b are located at both ends of the stacked bar 16, and the longitudinal direction of each stacked bar 16 is alternately changed by 180 degrees. Thus, the thermoelectric module 6 can be formed. The final shape of the thermoelectric elements 6a and 6b is illustrated as a cube in the illustrated example, but is not limited to a cube, and may be a rectangular parallelepiped. This can be achieved by adjusting the thickness of the cut in each slice or cut in (b).

  FIG. 4 is a cross-sectional view of an essential part showing a part broken along the line IV-IV in FIG. As shown in FIGS. 2 and 4, the lower case 4 is formed by, for example, drawing a copper thin plate material into a rectangular shape in a plan view by drawing, and outwardly from the outer peripheral edge of the concave portion 4 a. It is formed in a shape having an outward flange portion 4b extending in a bowl shape and surrounding the entire circumference of the recess 4a with a substantially constant width. Furthermore, an outer peripheral wall portion 4c that rises at a right angle in a direction opposite to the concave portion 4a is formed over the entire outer peripheral edge of the outward flange portion 4b.

  The upper case 5 is also formed by drawing a thin plate material made of copper, for example, into a concave shape 5a that is recessed in a rectangular shape in plan view, and extending outwardly from the outer peripheral edge of the concave portion 5a. It is formed in a shape having an outward flange portion 5b that surrounds the entire circumference with a substantially constant width. The outward flange portion 5b is formed in a similar shape and slightly smaller than the outward flange portion 4b of the lower case 4. The material of the cases 4 and 5 is not limited to copper, and aluminum, zinc alloy, stainless steel, brass, and the like can be applied.

  The bottom surface 4d of the recess 4a of the lower case 4 is formed in a rectangular plane as a whole. A polyimide film 21 having a thickness of, for example, about 5 μm is adhered to the entire bottom surface of the recess 4a on the bottom surface 4d, and a plurality of strip-like terminals 22 made of, for example, copper foil are provided on the surface of the film 21. Has been placed. The shape of the strip-shaped terminal 22 is adjacent to each other in a state of having a length straddling the adjacent thermoelectric elements 6a and 6b and arranged in order to electrically connect one end of the adjacent thermoelectric elements 6a and 6b alternately. The band-shaped terminals 22 are formed in a size that does not contact each other. The strip-like terminal 22 is not limited to copper foil, and may be any conductive material that can be formed into a thin shape. For example, the belt-like terminal 22 may be formed by thermal spraying using a conductive thermal spray material or solder reflow. May be.

  FIG. 5 is an enlarged cross-sectional view of a main part showing a part broken along the line VV in FIG. As shown in the drawing, the bottom surface 5d of the concave portion 5a of the upper case 5 is also formed in the same manner as the bottom surface 4d of the concave portion 4a of the lower case 4, and the film 21 is also adhered to the bottom surface 5d. A plurality of strip-like terminals 23 are disposed on the surface of the film 21. The belt-like terminal 22 on the lower case 4 side and the belt-like terminal 23 on the upper case 5 side connect the adjacent thermoelectric elements 6a and 6b to the upper and lower surfaces of the thermoelectric elements 6a and 6b (upper case 4 side). And each surface with respect to the lower case 5 side) are arranged so as to be alternately connected in the arrangement direction of the thermoelectric elements 6a and 6b. In this manner, in the central thermoelectric element 6a of FIG. 5, the current flowing from the left thermoelectric element 6b through the upper band-shaped terminal 23 is directed to the right thermoelectric element 6b through the lower band-shaped terminal 22. The plurality of thermoelectric elements 6a and 6b are connected in series so as to flow.

  Adjacent ones of the thermoelectric elements 6a and 6b are filled with the above-described adhesive 13, and the thermoelectric elements 6a and 6b are bonded to each other and integrated into a rectangular plate shape as a whole. For the adhesive 13, for example, insulating particles 26 having a particle size of about several μm to 20 μm are mixed in an epoxy resin adhesive, a thermosetting adhesive, or the like with an insulating material having high heat resistance such as a fluororesin such as PTFE. Is. In this way, an insulating adhesive is formed. The insulating adhesive is not limited to an adhesive mixed with insulating particles, and may be, for example, insulating paper in which an adhesive is applied on both sides.

  Thereby, between each thermoelectric element 6a * 6b can be narrowed to the particle size grade of the insulating particle 26, and the electrical insulation between each thermoelectric element 6a * 6b is ensured in the state. When the particle size of the insulating particles 26 is as described above, the gap is very small, and the plurality of thermoelectric elements 6a and 6b can be integrated in a close contact state. Therefore, when the thermoelectric elements 6a and 6b having the same size are arranged in the vertical and horizontal directions, the overall size (thermoelectric module 6) can be reduced as much as possible, and the thermoelectric conversion device having the same heat transfer capability can be greatly downsized The amount of cooling per unit area can be increased.

  In the illustrated thermoelectric conversion device 1, the currents supplied from one lead wire 3 a are arranged in the direction indicated by the arrow A in FIG. 2 as indicated by the arrow A in FIGS. 1 and 2. The thermoelectric element 6b located next to the next row from the thermoelectric element 6a (6b) located at the end opposite to the lead wire 3a flows to the electric heating elements 6a and 6b arranged in the same direction via (23). (6a) flows as shown by the arrow B in FIG. 2, and then flows in one row in the opposite direction to the arrow A via each strip-like terminal 22 (23) in the adjacent row, and ends at the lead wire 3a side. 2 flows from the thermoelectric element 6a (6b) located at the side of the adjacent row to the thermoelectric element 6b (6a) located next to the adjacent row as shown by an arrow C in FIG. As shown in FIG. 5, the other lead wire 3b flows to the external circuit.

  Further, as shown in FIG. 4, the thermoelectric elements 6 are sandwiched between the cases 4 and 5 in order to bring the thermoelectric elements 6a and 6b sandwiched between the cases 4 and 5 and the belt-like terminals 22 and 23 into close contact with each other. In the state, each dimension is set so that a gap is generated between the outward flange portions 4b and 5b. Further, the outer flange portions 4b and 5b are provided so that the tag 24 formed in a rectangular ring shape with a thickness that fills the gap substantially fully is sandwiched.

  A space not filled with the tag 24 between the two outward flange portions 4b and 5b is filled with a sealing agent 25 such as silicon rubber, so that the lower case 4 and the upper case 5 are integrated. In the illustrated example, a gap is formed between the outer edge of the lower outward flange 4b and the outer edge of the upper outward flange portion 5b, and a part of the tag 24 is exposed in the gap. Accordingly, the tag 24 is formed of a material having air permeability, so that the air flow between the inside and outside due to the temperature change in the case 2 is secured, and a filter for dust when air flows in from the outside, and Can play a role of moisture absorption.

  FIG. 6 is an enlarged cross-sectional view showing a main part of the surface shape of the recess 5 a of the upper case 5. When a current is passed from one lead wire 3a to the other lead wire 3b, for example, the concave portion 5a side of the upper case 5 becomes low temperature. As shown in the drawing, a plurality of convex portions 31 having a concave and convex shape are provided on the upper surface (front surface) which is the outer side of the concave portion 5a. Moreover, the protrusion direction end surface 31a of each convex-shaped part 31 is formed so that it may be located on the same surface shown by the dashed-two dotted line 32 of a figure. The plurality of convex portions 31 can be formed, for example, by forming the shape of a die for drawing the upper case 5 into a shape corresponding to the convex portion 31, or may be formed by staring.

  For example, when the upper case 5 is pressed into a concave shape with a thin metal such as a copper plate, and the portion that becomes the concave bottom surface is formed into a flat surface, it is known that the flatness deteriorates as it is. Therefore, when a flat surface formed by press working is brought into contact with an external member that is a heat transfer partner, there is a problem that the entire surface is difficult to contact and the heat transfer capability is low.

  On the other hand, in the case of processing into a concavo-convex shape having a plurality of convex portions 31 and generating minute compressed portions between the convex portions 31 by the above-described star machining or the like, the flatness of the plate-like portion is increased. Accuracy can be ensured. Thereby, each protrusion direction end surface 31a can be located on the same plane, and it becomes possible to make the whole protrusion direction end surface 31a contact the heat transfer target surface of the external member entirely, ensuring high heat transfer efficiency, Heat transfer capability can be improved. Thereby, for example, when a cooling object (not shown) is cooled by the thermoelectric converter 1, the cooling object as an external member can be efficiently cooled.

  FIG. 7 is a view showing each modification corresponding to FIG. Note that portions similar to those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 7A is a view in which the outer peripheral wall 4c formed in the lower case 4 of FIG. 4 is omitted. In the first modification, the upper and lower outward flange portions 4b and 5b extend in parallel with each other, and the outer peripheral surface of the tag 24 sandwiched between the outward flange portions 4b and 5b via the sealant 25 is formed. It is exposed to the outside of the case 2 from between both the outward flange portions 4b and 5b. Thereby, the air flow between the inside and outside of the case 2 can be ensured in the same manner as described above.

  FIG. 7B shows a case where the upper case 33 is formed in the shape of a single plate-like body without forming the recess 5a of the upper case 5 of FIG. In the second modification, the surface 33a of the upper case 33 is wider than the area of the bottom surface 5d when the recess 5a is provided as shown in FIG.

  FIG. 7C is a view in which the outward flange portions 4b and 5b of the lower and upper cases 4 and 5 of FIG. 4 are omitted. In the third modified example, the lower case 34 and the upper case 35 have respective recesses 34a and 35a corresponding to the respective recesses 4a and 5a. The outer peripheral portions of the concave portions 34a and 35a are provided with outer peripheral wall portions 34b and 35b that are bent in directions facing each other. In the third modification, the case 2 can be made compact by not providing the outward flange portions 4b and 5b.

  FIG. 7D is a view in which the distal end portions of the outer peripheral wall portions 34b and 35b of FIG. Also in the fourth modified example, the lower case 36 and the upper case 37 have respective recesses 36a and 37a corresponding to the respective recesses 4a and 5a as a whole. The outer peripheral portions of the concave portions 36a and 36b are respectively provided with outer peripheral wall portions 36b and 37b that are bent in directions facing each other, and further from the end in the standing direction of the outer peripheral wall portions 36b and 37b. The inward flange portions 36c and 37c that are bent so as to extend obliquely toward the bottom surface side are provided. In the fourth modified example, the heat transfer capability can be increased by increasing the contact area of the recess 36a (37a) with the external member, and the inward flange portion bent with respect to the outer peripheral wall portion 36b (37b). The strength of the outer peripheral wall portion 36b (37b) is increased by 36c (37c). Thereby, the flatness of the bottom part of the recessed part 36a (37a) is further ensured.

  FIG. 7E shows the inward edges 36c and 37c shown in FIG. Also in the fifth modification, the lower case 38 and the upper case 39 respectively have the recesses 38a and 39a corresponding to the recesses 4a and 5a as a whole. Similar to the outer peripheral wall portions 36b and 37b, the outer peripheral wall portions 38b and 39b are provided on the outer peripheral portions of the concave portions 36a and 36b, respectively. Each of the inwardly directed flange portions 38c and 39c is provided. As shown in the drawing, the inwardly facing portions 38c and 39c are formed in a wave shape as a whole toward the bottom surface side of the recesses 38a and 39a obliquely toward the opposite side of the bottom surface. This fifth modification also has the same effect as the fourth modification. In addition, the inward flange 38c (39c) is bent in a V shape, and the strength is further increased.

  FIG. 8 is an enlarged perspective view of a main part showing the wiring procedure of the dummy member 7 and the thermoelectric elements 6a and 6b. As shown in the figure, the core wire exposed by removing the covering of the lead wire 3 a is soldered to the side surface 7 a of the dummy member 7 by the solder 40. The lead wire 3b is the same, and its illustration is omitted.

  The dummy member 7 is disposed at one corner of the rectangular thermoelectric module 6, and the side surface 7 a to be soldered may be a surface facing outward of the thermoelectric module 6. Although the solder 40 swells from the side surface 7a, in the state where the thermoelectric module 6 is received in the case 2, there is a gap between the inner peripheral wall surfaces of the recesses 4a and 5a, and the solder 40 is in the gap. Can fit. Further, the exposed portions of the solder 40 and the lead wires 3a are covered with an insulating material (not shown).

  In the present embodiment, the dummy member 7 is formed in the same shape as the thermoelectric elements 6a and 6b, and a substantially square strip-shaped terminal 22a is provided at the position where the dummy member 7 is arranged to match the height. Alternatively, the dummy member 7 may be formed larger by the thickness of the band-shaped terminal 22a, and the arrangement of the band-shaped terminal 22a may be omitted.

  In such a structure in which the dummy member 7 is not disposed, a space is generated in the portion, and a lead wire is soldered to a terminal exposed in the space. In that case, there is a possibility that the strength of the portion is lowered. On the other hand, by connecting to the lead wire 3a via the dummy member 7, the entire recesses 4a and 5a are filled with the thermoelectric module 6, so that the bottom portions of the recesses 4a and 5a High strength is maintained over the entire surface.

  The present invention has been described with reference to the preferred embodiments. However, as those skilled in the art can easily understand, the present invention is not limited to such embodiments, and the gist of the present invention. As long as it does not deviate from the above, it can be appropriately changed. In addition, all the components shown in the above embodiment are not necessarily essential, and can be appropriately selected without departing from the gist of the present invention.

  Since the thermoelectric conversion device according to the present invention can achieve high thermal conductivity, increase strength, and can be made compact, it is useful as a device that performs cooling or power generation using a thermoelectric element.

DESCRIPTION OF SYMBOLS 1 Thermoelectric converter 2 Case 3a * 3b Lead wire 4 Lower case 5 Upper case 4a * 5a Recessed part 4b * 5b Outward flange part 6a * 6b Thermoelectric element 7 Dummy member 13 Adhesive 26 Insulating particle

Claims (4)

A thermoelectric conversion device having a plurality of thermoelectric elements, first and second case divided bodies that sandwich the plurality of thermoelectric elements, and a plurality of connection terminals for connecting the plurality of thermoelectric elements in series,
An electroconductive relay member for external connection connected to both ends of the series connection of the plurality of thermoelectric elements and sandwiched between the first and second case divided bodies together with the plurality of thermoelectric elements. Thermoelectric conversion device.   The thermoelectric element and the conductive relay member are formed in the same shape as each other, and are arranged so as to form a rectangular outer shape in a plan view by being arranged in a plurality of rows and columns. Thermoelectric conversion device.   The thermoelectric conversion device according to claim 1 or 2, wherein the plurality of thermoelectric elements are bonded and integrated with each other by an insulating adhesive filled between adjacent ones.   The thermoelectric conversion device according to claim 3, wherein the insulating adhesive is obtained by mixing insulating particles in an adhesive.

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