JP2017059698A - Manufacturing method for thermoelectric transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for thermoelectric transducer, excellent in productivity.SOLUTION: A manufacturing method for thermoelectric transducer includes a preparation step of arranging at least one P type thermoelectric conversion prismatic rod and at least one N type thermoelectric conversion prismatic rod in a row with a space between each other, an electrode plate arrangement step of arranging a first electrode plate on the upper surface of the thermoelectric conversion prismatic rod, and arranging a second electrode plate on the lower surface of the thermoelectric conversion prismatic rod, so as to straddle the P type thermoelectric conversion prismatic rod and N type thermoelectric conversion prismatic rod, and arranging the second electrode plate on the lower surface of thermoelectric conversion prismatic rod, and a fragmentation step of obtaining a plurality of thermoelectric conversion elements by fragmentation for cutting the electrode plate and thermoelectric conversion prismatic rod, on a surface orthogonal to the longitudinal direction of the thermoelectric conversion prismatic rod.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a thermoelectric conversion element.

  The thermoelectric conversion material is a material that can directly convert thermal energy into electricity, or can directly convert electrical energy into thermal energy, that is, can be heated and cooled by applying electricity.

  In a thermoelectric conversion module using a thermoelectric conversion material, a plurality of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements are alternately arranged. A thermoelectric conversion element is formed by connecting a P-type thermoelectric conversion element and an N-type thermoelectric conversion element in series. If there is a temperature difference between both ends of the thermoelectric conversion element, electricity due to the Seebeck effect is generated. Thereby, heat energy can be converted into electric energy. If a thermoelectric conversion element is used, it is possible to effectively use energy by converting waste heat, which has not been used so far, into electricity.

  As a conventional method of manufacturing a thermoelectric conversion element, a method of joining a set of thermoelectric conversion elements (one P-type and one N-type thermoelectric conversion element) on one electrode plate has been adopted. This type of technology is described in, for example, Patent Document 1. According to this document, an electrode is placed on a support jig, a P-type thermoelectric conversion element and an N-type thermoelectric conversion element are placed on the electrode while being aligned, and the electrode is placed on each thermoelectric element. It is described that an electrode, a P-type thermoelectric conversion element, and an N-type thermoelectric element are metal-bonded by pressing a pressure jig from the side and applying pressure to heat (see FIG. 2, paragraph 0024 of Patent Document 1). . That is, a method of joining a pair of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements (each one each) on one electrode is used.

JP 2014-78663 A

  As a result of investigation by the present inventors, the method of joining a set of thermoelectric conversion elements (one each for P-type and N-type) on one electrode plate has room for improvement in terms of productivity. It was.

  The inventor has intensively studied to solve the above problems. As a result, after installing P-type and N-type thermoelectric conversion prismatic rods on the electrode plate, cutting these thermoelectric conversion prismatic rods, the knowledge that multiple sets of thermoelectric conversion elements can be obtained collectively As a result, the present invention has been completed.

According to the present invention, at least one P-type thermoelectric conversion prismatic bar and at least one N-type thermoelectric conversion prismatic bar are arranged in a horizontal row in a state of being separated from each other;
A first electrode plate is disposed on the upper surface of the thermoelectric conversion prismatic rod so as to straddle the P-type thermoelectric conversion prismatic rod and the N-type thermoelectric conversion prismatic rod, and the first electrode plate is disposed on the lower surface of the thermoelectric conversion prismatic rod. An electrode plate arranging step of arranging two electrode plates;
A singulation step of obtaining a plurality of thermoelectric conversion elements by singulation processing for cutting the electrode plate and the thermoelectric conversion prismatic rod on a surface orthogonal to the longitudinal direction of the thermoelectric conversion prismatic rod. An element manufacturing method is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the thermoelectric conversion element excellent in productivity is provided.

It is process sectional drawing which shows the manufacturing process of the thermoelectric conversion element which concerns on this embodiment. It is process sectional drawing which shows the manufacturing process of the thermoelectric conversion element which concerns on this embodiment. It is process sectional drawing which shows the manufacturing process of the thermoelectric conversion element which concerns on this embodiment. It is process sectional drawing which shows the manufacturing process of the thermoelectric conversion element which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.
In the present embodiment, description will be made by defining the front-rear, left-right, up-down directions as shown. However, this is provided for the sake of convenience in order to briefly explain the relative relationship between the components. Therefore, the direction at the time of manufacture and use of the product which implements the present invention is not limited.

  An outline of a method for manufacturing a thermoelectric conversion element according to this embodiment will be described.

  The manufacturing method of the thermoelectric conversion element of this embodiment includes at least one or more P-type thermoelectric conversion prisms (P-type thermoelectric conversion prisms 42) and at least one N-type thermoelectric conversion prisms (N-type thermoelectric conversion prisms). Rod 40) are arranged in a horizontal row in a state of being separated from each other, a P-type thermoelectric conversion prismatic rod (P-type thermoelectric conversion prismatic rod 42) and an N-type thermoelectric conversion prismatic rod (N-type thermoelectric conversion prism) The first electrode plate (electrode plate 60) is disposed on the upper surface of the thermoelectric conversion prismatic bar and the second electrode plate (electrode plate 62) is disposed on the lower surface of the thermoelectric conversion prismatic rod so as to straddle the rod 40). The electrode plates 60 and 62 and the thermoelectric conversion prismatic rod (P-type thermoelectric conversion prismatic rod 42 and N-type thermoelectric conversion prismatic rod 40) are cut at a plane orthogonal to the longitudinal direction of the thermoelectric conversion prismatic rod. A singulation process for obtaining a plurality of thermoelectric conversion elements by singulation processing It can contain. The thermoelectric conversion module 100 of the present embodiment can be formed by combining one or more sets of the obtained thermoelectric conversion elements.

  According to the method for manufacturing a thermoelectric conversion element of this embodiment, P-type and N-type thermoelectric conversion prismatic bars (P-type thermoelectric conversion prismatic pole 42 and N-type thermoelectric conversion prismatic pole 40) are provided between the electrode plates 60 and 62. After installation, these thermoelectric conversion prismatic bars are cut. As a result, two or more P / N thermoelectric conversion elements having the N-type thermoelectric conversion element 140, the P-type thermoelectric conversion element 142, and the electrode plates 160 and 162 as constituent elements can be manufactured simultaneously. The manufacturing method of the thermoelectric conversion element of this embodiment is excellent in productivity as compared with the conventional manufacturing method in which the thermoelectric conversion elements are formed one by one.

Each process of the manufacturing method of the thermoelectric conversion element of this embodiment is explained in full detail.
1-4 show process cross-sectional views of a method for manufacturing a thermoelectric conversion element.

  First, a semiconductor wafer is prepared. As shown in FIG. 1A, two types of N type and P type (N type semiconductor wafer 10 and P type semiconductor wafer 12) are prepared. The semiconductor wafer may be circular or quadrangular in plan view. The semiconductor wafer is not particularly limited as long as it is a plate member having an area enough to cut out a plurality of thermoelectric conversion prismatic bars.

  The semiconductor wafer is obtained, for example, by pulverizing and pulverizing a thermoelectric conversion material, and solidifying and sintering the powder. As a thermoelectric conversion material which comprises a semiconductor wafer, the same kind as the thermoelectric conversion material which comprises the below-mentioned N type thermoelectric conversion element 140 and P type thermoelectric conversion element 142 can be used.

  As a method for manufacturing a semiconductor wafer, known means can be used. Dissolution method, rapid solidification method (gas atomization, water atomization, centrifugal atomization, single roll method, twin roll method) or ball mill method (mechanical alloying method), hot press method, heat sintering method, discharge plasma molding method, Or it can produce by combining the heat processing method. For example, first, the raw material of the thermoelectric conversion material is melted, and the powder of the thermoelectric conversion material is produced by the gas atomization method. Subsequently, the obtained powder is filled into a die, and a columnar shaped body of a thermoelectric conversion material is obtained by a discharge plasma sintering method. The obtained columnar shaped body is sliced with a multi-wire saw or the like and cut into a predetermined thickness. Thereby, the above-described semiconductor wafer having a predetermined planar shape is obtained.

  Moreover, you may grind | polish both surfaces of the obtained semiconductor wafer to a predetermined film thickness before the above-mentioned preparatory process (FIG. 1 (a)). Thereby, the surface of the semiconductor wafer can be flattened. The surface of the semiconductor wafer becomes a bonding surface of a thermoelectric conversion element bonded to an electrode plate or the like through a manufacturing process. For this reason, if the excessive unevenness | corrugation of a joint surface can be suppressed, since adhesiveness with an electrode plate can be improved, the thermoelectric conversion element excellent in reliability is realizable.

  Next, the diffusion preventing layer 20 can be formed on at least one surface of the semiconductor wafer. For example, as shown in FIG. 1B, the diffusion prevention layer 20 is formed on both surfaces (upper surface 14 and lower surface 16) of the N-type semiconductor wafer 10. For example, the diffusion preventing layer 20 can be formed by a plating method or the like. Similarly, the diffusion preventing layer 20 may be formed on both sides of the P-type semiconductor wafer 12. Thereby, before the above-mentioned preparatory process, the diffusion prevention layer 20 can be formed over the whole surface of the semiconductor wafer. In addition, since the diffusion preventing layer 20 can be collectively formed on one surface of a large area, process productivity can be improved.

  Next, the semiconductor wafer is divided into a plurality along one direction. Thereby, a prismatic thermoelectric conversion member extending in a predetermined direction can be obtained. For example, as shown in FIG. 1C, the N-type semiconductor wafer 10 is cut along the dicing area 30 in the film thickness direction of the N-type semiconductor wafer 10 by a multi-wire saw, a dicer, a blade saw, a laser, or the like. To do. In the present embodiment, dicing is performed a plurality of times on a surface parallel to one direction of the predetermined dicing region 30 (straight dicing line). When the N-type semiconductor wafer 10 has a circular shape, dicing may be performed on the dicing region 32 in a direction orthogonal to the dicing region 30 in order to align the lengths of the obtained prismatic bars. For example, the adjacent width of the dicing region 32 is made wider than the adjacent width of the dicing region 30. Thereby, as shown in FIG.1 (d), multiple prismatic bars (N type thermoelectric conversion prismatic bar 40) extended in the predetermined direction can be obtained. When the N-type semiconductor wafer 10 has a quadrangular shape, dicing does not have to be performed in the dicing region 32 orthogonal to the dicing region 30. The P-type semiconductor wafer 12 is also divided in the same manner as the N-type semiconductor wafer 10 to obtain a plurality of P-type thermoelectric conversion prisms 42.

  As shown in FIG. 2A, the longitudinal direction (L), the height direction (H), and the width direction (W) represent mutually orthogonal coordinate axes in the three-dimensional space coordinates. For example, the N-type thermoelectric conversion prismatic bar 40 is a quadrangular prism extending in a predetermined longitudinal direction (L). The surface (upper surface 44, lower surface 46) of the N-type thermoelectric conversion prismatic bar 40 serves as a bonding surface and extends in the same direction as the above-described longitudinal direction (L). The film thickness direction from the upper surface 44 to the lower surface 46 is defined as a height direction (H). The direction perpendicular to the plane formed by the height direction (H) and the longitudinal direction (L) is defined as the width direction (W).

  In the present embodiment, the length of the N-type thermoelectric conversion prismatic bar 40 in the longitudinal direction (L) is larger than the length in the width direction (W). For example, the ratio of the length in the longitudinal direction (L) to the width direction (W) may be 2 times or more, or 3 times or more. By increasing the length ratio, the number of obtained thermoelectric elements can be increased, so that productivity can be improved. Further, the upper limit value of the length ratio is not particularly limited, but may be, for example, 100 times or less.

  Next, thermoelectric conversion prismatic bars obtained by dividing the semiconductor wafer are arranged in a predetermined pattern. That is, at least one or more P-type thermoelectric conversion prisms (P-type thermoelectric conversion prisms 42) and at least one N-type thermoelectric conversion prisms (N-type thermoelectric conversion prisms 40) are separated from each other. Then, a preparatory process is performed, which is arranged in a horizontal row.

  Specifically, as shown in FIG. 2A, a P-type thermoelectric conversion prismatic rod (P-type thermoelectric conversion prismatic rod 42) and an N-type thermoelectric conversion prismatic rod (N-type thermoelectric conversion prismatic rod 40) are used. Place them alternately. For example, in the present embodiment, the thermoelectric conversion prismatic rods may be arranged side by side in a plurality of pairs of P-type and N-type so that the P-type and N-type are alternately arranged. In the above-described preparation step, the P-type thermoelectric conversion prismatic rod 42 and the N-type thermoelectric conversion prismatic rod 40 are arranged with their longitudinal directions (L) aligned, and their upper surfaces 44 (joint surfaces) constitute the same surface. To be arranged.

  Further, in the above-described preparation step, a thin layer member is provided between the P-type thermoelectric conversion column (P-type thermoelectric conversion rectangular column 42) and the N-type thermoelectric conversion column (N-type thermoelectric conversion prism 40). You may arrange | position mutually spaced apart in the state arrange | positioned. Thus, the arrangement can be performed without sticking to each other while the gap distance between the P-type thermoelectric conversion prismatic rod 42 and the N-type thermoelectric conversion prismatic rod 40 is kept constant. Thereby, compared with the case where it arrange | positions using alignment, a gap | interval distance can be kept constant easily. For this reason, the yield of a manufacturing process can be improved.

  The thin layer member in the present embodiment can be sandwiched between the P-type thermoelectric conversion prismatic rod 42 and the N-type thermoelectric conversion prismatic rod 40, and has a strength sufficient to maintain the gap distance between them, and has an electrical insulating property. However, for example, a ceramic member, a heat resistant member, a paper member, or the like can be used. Among these, the paper member is lightweight and easy to handle.

  Next, after the above-described preparation step, a joining member is formed on the joining surface (upper surface 44, lower surface 46) of the thermoelectric conversion prismatic bar. Specifically, as shown in FIG. 2 (b), these thermoelectric conversion prismatic bars (P-type thermoelectric conversion prismatic bars 42) so as to straddle the P-type thermoelectric conversion prismatic bars and the N-type thermoelectric conversion prismatic bars. The joining member 50 is disposed on the upper surface 44 and the lower surface 46 of the N-type thermoelectric conversion prismatic bar 40). In the present embodiment, for example, a brazing material is used as the joining member 50. For example, the bonding member 50 (the brazing material) is entirely applied to the same surface formed by the upper surface 44 (and the lower surface 46) of the P-type thermoelectric conversion prismatic rod 42 and the N-type thermoelectric conversion prismatic rod 40 by a technique such as coating. Can be formed (brazed). Thereby, the joining member 50 can be apply | coated to the whole joining surface. Further, the conventional complicated jig for brazing is not required, and the manufacturing process can be simplified.

  Here, Patent Document 1 describes a conventional brazing process. In the brazing process, after brazing a brazing material to the central portion of the small-area joining surface of the thermoelectric conversion element, the brazing material is spread from the central portion to the end by pressing the electrode plate. However, in such a method, the brazing material is not spread so far in the outer edge portion of the joint surface, and there is a case where the brazing material is not formed. On the other hand, if a brazing material is applied too much, the brazing material may flow out to the side wall surface of the thermoelectric conversion element, and adjacent thermoelectric conversion elements may be short-circuited.

  On the other hand, in this embodiment, the joining member 50 can be formed on the whole joining surface by a simple coating method as described above. Thereby, the joining stability of the thermoelectric conversion element of this embodiment and an electrode plate can be improved. Further, in a later process, unnecessary portions of the bonding member 50 around the thermoelectric conversion element are deleted by dicing. For this reason, in this embodiment, the short circuit of the unintended thermoelectric conversion elements can be suppressed.

Next, the electrode plates 60 and 62 are formed on the joining surface of the thermoelectric conversion prismatic bar via the joining member 50. Specifically, as shown in FIG. 2B, a P-type thermoelectric conversion prismatic rod (P-type thermoelectric conversion prismatic rod 42) and an N-type thermoelectric conversion prismatic rod (N-type thermoelectric conversion prismatic rod 40) are used. A first electrode plate (electrode plate 60) is disposed on the upper surface 44 of the thermoelectric conversion prismatic bar, and a second electrode plate (electrode plate 62) is disposed on the lower surface 46 of the thermoelectric conversion prismatic rod so as to straddle. That is, the electrode plates 60 and 62 can be disposed across a plurality of joint surfaces formed of a set of P-type and N-type. Thereafter, the electrode plates 60 and 62 are pressurized and heated, whereby the electrode plates 60 and 62, the joining member 50, and a plurality of thermoelectric conversion prismatic rods (N-type thermoelectric conversion prismatic rod 40, P-type thermoelectric conversion prismatic rod 42). ) Can be joined and integrated.
A gap 48 is formed between the adjacent P-type thermoelectric conversion prismatic bar 42 and N-type thermoelectric conversion prismatic bar 40. The width L of the gap 48 may be the same, but may be different depending on the design. Further, as shown in FIG. 2B, the joining member 50 is formed over the entire lower surface of the electrode plate 60 and the entire upper surface of the electrode plate 62. That is, the joining member 50 is also formed at the upper and lower ends of the gap 48 between the P-type thermoelectric conversion prismatic rod 42 and the N-type thermoelectric conversion prismatic rod 40.

  Next, in the above-described individualization step, an individualization process for cutting the electrode plates 60 and 62 and the thermoelectric conversion prismatic bar is performed on a surface orthogonal to the longitudinal direction (L) of the thermoelectric conversion prismatic bar. Specifically, as shown in FIG. 3A, a parallel line (dicing) with respect to a plane orthogonal to the longitudinal direction (L) (a plane formed by the height direction (H) and the width direction (W)). Multiple dicing is performed along the line 70). In dicing, a plurality of thermoelectric conversion prismatic bars (N-type thermoelectric conversion prismatic bar 40 and P-type thermoelectric conversion prismatic pole 42) are simultaneously cut from the upper electrode plate 60 to the lower electrode plate 62. Thereby, the N-type thermoelectric conversion prismatic bar 40 and the P-type thermoelectric conversion prismatic bar 42 can be singulated, respectively. That is, a plurality of sets of N-type thermoelectric conversion elements 140 and P-type thermoelectric conversion elements 142 can be formed (FIG. 3B).

  Next, in the above-described singulation process, after the singulation process on the surface formed by the height direction (H) and the width direction (W), the electrodes are arranged along the longitudinal direction (L) of the thermoelectric conversion prismatic rod. An electrode plate dividing step for dividing the plate is performed. In the electrode plate dividing step, only one of the first electrode plate (electrode plate 60) and the second electrode plate (electrode plate 62) is applied to the dividing surface direction of the electrode plates 60 and 62. To divide. Specifically, as shown in FIG. 3B, the parallel lines are diced with respect to the surface along the longitudinal direction (L), that is, the surface formed by the height direction (H) and the longitudinal direction (L). Lines 80 and 82 are used. Either the electrode plate 60 or the electrode plate 62 is cut along the dicing lines 80 and 82. For example, along the width direction (W), the electrode plates 60, 62 can be cut in the order of the lower electrode plate 62, the upper electrode plate 60, the lower electrode plate 62,. . That is, in the electrode plate dividing step, the first electrode plate (electrode plate 60) and the second electrode plate (electrode plate 62) are alternately arranged in a cross-sectional view orthogonal to the longitudinal direction (L) of the thermoelectric conversion prismatic bar. Dicing can be performed.

  The series connection structure of the adjacent N-type thermoelectric conversion element 140 and P-type thermoelectric conversion element 142 can be formed by the electrode plate dividing step of the present embodiment. Also, a structure in which adjacent N-type thermoelectric conversion elements 140 and P-type thermoelectric conversion elements 142 are connected in series is formed from a structure in which a plurality of thermoelectric conversion elements are continuous as shown in FIG. It becomes possible (FIG. 4A). In other words, a combination of thermoelectric conversion elements in which N-type, P-type, N-type... P-type are alternately arranged and connected in series can be formed.

In the above-described electrode plate dividing step, the electrode plates 60 and 62 are cut, and the thermoelectric conversion elements need not be cut. This is because a gap 48 is formed between the adjacent P-type thermoelectric conversion element 142 and N-type thermoelectric conversion element 140. For example, the width of the gap portion 48 can be approximately the same as the dicing width of the dicing lines 80 and 82. Further, in the above-described electrode plate dividing step, not only the electrode plates 60 and 62 but also the unnecessary joining member 50 existing between the N-type thermoelectric conversion element 140 and the P-type thermoelectric conversion element 142 can be cut.
3B, the joining member 50 is formed over the entire lower surface of the electrode plate 60 on the non-diced side or the entire upper surface of the electrode plate 62. In FIG. For this reason, the adhesive strength between the electrode plates 60 and 62 and the thermoelectric conversion elements (P-type thermoelectric conversion element 142 and N-type thermoelectric conversion element 140) can be strengthened.

  Through the above steps, the thermoelectric conversion module 100 shown in FIG. 4A is obtained.

  The thermoelectric conversion module 100 of this embodiment is freely combinable. For example, as shown in FIG. 4 (b), the thermoelectric conversion modules 100 shown in FIG. 4 (a) are arranged side by side, and each thermoelectric conversion module 100 is connected by an electrode plate 92. It can be formed easily. Also, the module size can be adjusted very easily. An external lead wire (lead wire 90) may be formed at the end of the thermoelectric conversion module 100.

  In the present embodiment, the joining member 50 is cut together with the electrode plates 60 and 62 by dicing. For this reason, it is possible to sufficiently suppress a short circuit caused by the bonding member 50 between the adjacent N-type thermoelectric conversion element 140 and P-type thermoelectric conversion element 142.

  In the present embodiment, the electrode plates 60 and 62 are formed between the N-type thermoelectric conversion element 140 and the P-type thermoelectric conversion element 142 adjacent to each other, and then cutting is performed by dicing. For this reason, in the N-type thermoelectric conversion prismatic rod 40 and the P-type thermoelectric conversion prismatic rod 42, it is possible to eliminate the deburring process performed for the purpose of preventing a short circuit due to element burrs.

The thermoelectric conversion module 100 of this embodiment is demonstrated.
The thermoelectric conversion module 100 of the present embodiment includes at least one set of an N-type thermoelectric conversion element 140 and a P-type thermoelectric conversion element 142. In addition to the thermoelectric conversion element, the thermoelectric conversion module 100 can include a connection member such as a diffusion prevention layer 120, a bonding member 150, and electrode plates 160 and 162. N-type thermoelectric conversion element 140 and P-type thermoelectric conversion element 142 are connected in series via a connecting member.

  The components of the thermoelectric conversion module 100 will be described in detail.

  The N-type thermoelectric conversion element 140 and the P-type thermoelectric conversion element 142 are made of a thermoelectric conversion material having thermoelectric conversion characteristics. Examples of thermoelectric conversion materials include silicon-germanium, iron-silicon, bismuth-tellurium, magnesium-silicon, magnesium-manganese, lead-tellurium, cobalt-antimony, clathlet, and Heusler alloys. And half-Heusler alloy systems.

Specifically, the N-type thermoelectric conversion element 140 and the P-type thermoelectric conversion element 142 are preferably made of an Sb-based thermoelectric conversion material having a skutterudite structure or a filled skutterudite structure. Sb system The thermoelectric conversion material, for example, the general _{formula: R r T t-m M} m Sb x-n N n (0 ≦ r ≦ 1,3 ≦ t-m ≦ 5,0 ≦ m ≦ 0.5, A compound having a structure represented by 10 ≦ x ≦ 15 and 0 ≦ n ≦ 2) can be used.

  R in the above general formula representing the Sb-based thermoelectric conversion material represents three or more elements selected from the group consisting of rare earth elements, alkali metal elements, alkaline earth metal elements, Group 4 elements and Group 13 elements. . T in the above general formula represents at least one selected from Fe, Co and Ni. M in the above general formula represents at least one selected from the group consisting of transition metals other than Fe, Co, Ni, and Group 4 elements. N in the above general formula represents at least one selected from the group consisting of Group 14 elements, Group 15 elements other than Sb, and Group 16 elements.

More specifically, the P-type thermoelectric conversion element 142 is made of an Sb-based compound having a filled skutterudite structure of (RE, AE, Ga, Ti) _{0.7 to 1.0} (Fe, Co) ₄ Sb _12. It may be configured. The N-type thermoelectric conversion element 140 is composed of an Sb-based compound having a filled skutterudite structure of (RE, AE, Al, Ga, In) _{0.5 to 0.8} (Fe, Co) ₄ Sb _12. Also good. The RE is at least one selected from the group consisting of rare earth elements of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Represent. The AE represents at least one selected from the group consisting of Ca, Sr, and Ba alkaline earth elements.

  The diffusion prevention layer 120 is bonded to the N-type thermoelectric conversion element 140 and the P-type thermoelectric conversion element 142, respectively. Specifically, the diffusion preventing layer 120 is formed on a bonding surface where the thermoelectric conversion element is bonded to another member. The diffusion preventing layer 120 can prevent the constituent components constituting these thermoelectric conversion elements from diffusing into the electrode plates 160, 162 and the like.

  The diffusion preventing layer 120 can be composed of, for example, an alloy plate. As the alloy plate, a rolled alloy plate (rolled material) can be used. The alloy plate may be flat or uneven. The average film thickness of the diffusion preventing layer 120 is not particularly limited, but can be, for example, 0.5 mm or less.

Specifically, the diffusion prevention layer 120 can use an M ₁ -M ₂ alloy. M ₁ represents at least one element selected from the group consisting of Fe, Co, and Ni. The M ₂ is Cr, Mo, W, V, Nb, Ta, Mn, Ti, Zr, Hf, Cu, B, Al, Ga, In, C, Si, Ge, Sn, Pb, N, P, Bi. , O, S, Se, and at least one element selected from the group consisting of Te.

  In the present embodiment, the semiconductor wafer can be diced after the diffusion prevention layer 20 is formed on the entire surface of the semiconductor wafer. Thus, the diffusion prevention layer 20 is formed over the entire surface (upper surface 44, lower surface 46) of the cut thermoelectric conversion prismatic rod (N-type thermoelectric conversion prismatic rod 40, P-type thermoelectric conversion prismatic rod 42). ing. That is, the diffusion preventing layer 20 can be formed over the entire surface to be the bonding surface. Thereby, in the thermoelectric conversion element of this embodiment, the component can exhibit the spreading | diffusion to an electrode etc. effectively.

  The joining member 150 physically couples the thermoelectric conversion elements such as the N-type thermoelectric conversion element 140 and the P-type thermoelectric conversion element 142 and the electrode plates 160 and 162. The bonding member 150 may be directly bonded to the thermoelectric conversion element or the electrode plates 160 and 162, but may be bonded via the diffusion prevention layer 120, the stress relaxation layer, or the like. Note that the bonding member 150 may have a diffusion preventing function and a stress relaxation function.

  The joining member 150 is formed by a joining method using sputtering, vapor deposition, plating, thermal spraying, SPS method (discharge plasma sintering method), adhesion with a conductive adhesive such as silver paste, soldering, brazing, or the like. ing. Among these, it is preferable to use a simple brazing method.

  The joining member 150 may be made of, for example, solder or brazing material. In the present embodiment, the brazing material is not particularly limited as long as it is an alloy (wax) having a lower melting point than the base material (thermoelectric conversion element or electrode plate) to be joined. For example, copper brazing, phosphorous copper brazing, silver brazing Aluminum wax, gold wax, palladium wax and the like are used.

  Specifically, as the brazing material, a phosphor copper brazing alloy (for example, P: 5 to 10 (wt%)-Ag: 5 to 10 (wt%), Sn: 5 to 10 (wt%)-Cu: 70 to 85 (weight%)), Ag braze alloy (for example, Ag: 50-60 (wt%)-(Cu, Zn): 40-50 (wt%), Ag: 50-60 (wt%)-(Cu , Zn, Sn): 40 to 50 (% by weight) alloy).

  Electrode plates 160 and 162 are plate-like metal members that electrically join adjacent N-type thermoelectric conversion elements 140 and P-type thermoelectric conversion elements 142. The electrode plates 160 and 162 can be electrically connected to the thermoelectric conversion element via, for example, the diffusion prevention layer 120 and the bonding member 150.

  As an example of the connection structure of the electrode plates 160 and 162, for example, as shown in FIG. 4A, the electrode plate 160 (first electrode plate) is connected to the upper surface 144 of the first N-type thermoelectric conversion element 140. The upper surfaces of the first P-type thermoelectric conversion elements 142 are connected in series. The electrode plate 162 (second electrode plate) is a second P-type thermoelectric conversion different from the lower surface 146 of the first N-type thermoelectric conversion element 140 and the first P-type thermoelectric element to which the electrode plate 160 is joined. The lower surface 146 of the element 142 is connected in series. The first N-type thermoelectric conversion element 140 and the first P-type thermoelectric conversion element 142, and the first N-type thermoelectric conversion element 140 and the second P-type thermoelectric conversion element 142 are separated from each other and adjacent to each other. Are arranged.

  As the electrode plates 160 and 162, for example, a metal or alloy containing one or more selected from the group consisting of metals such as Fe, Co, Ni, Cr, Cu, Ti, Pd, Al, Sn, and Nb is used. it can. For example, copper plates can be used as the electrode plates 160 and 162. The metal material of the electrode plates 160 and 162 may be an alloy having the same composition as the bonding member 150. Thereby, the adhesiveness of the electrode plates 160 and 162 and the joining member 150 can be improved.

The electrode plates 160 and 162 are made of a metal or alloy having a thermal expansion coefficient in the range of 5 × 10 ⁻⁶ (/ K) to 25 × 10 ⁻⁶ (/ K) in the range of 20 ° C. to 600 ° C. May be. Specifically, as the electrode plates 160 and 162, for example, rolled material stainless steel such as SUS405, SUS410, SUS420, and SUS430, tough pitch copper, deoxidized copper, oxygen-free copper, Cu—Zr alloy, Cu—Cr alloy, Pure Cu, Cu alloy, or the like can be used.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

DESCRIPTION OF SYMBOLS 10 N-type semiconductor wafer 12 P-type semiconductor wafer 14 Upper surface 16 Lower surface 20 Diffusion prevention layers 30 and 32 Dicing area 40 N-type thermoelectric conversion prismatic bar 42 P-type thermoelectric conversion prismatic rod 44 Upper surface 46 Lower surface 48 Gap 50 Bonding members 60 and 62 Electrode plate 70, 80, 82 Dicing line 90 Lead wire 92 Electrode plate 100 Thermoelectric conversion module 140 N-type thermoelectric conversion element 142 P-type thermoelectric conversion element 144 Upper surface 146 Lower surface 120 Diffusion prevention layer 150 Joining member 160, 162 Electrode plate

Claims (12)

A preparatory step of arranging at least one P-type thermoelectric conversion prismatic bar and at least one N-type thermoelectric conversion prismatic rod in a horizontal row in a state of being separated from each other;
A first electrode plate is disposed on the upper surface of the thermoelectric conversion prismatic rod so as to straddle the P-type thermoelectric conversion prismatic rod and the N-type thermoelectric conversion prismatic rod, and the first electrode plate is disposed on the lower surface of the thermoelectric conversion prismatic rod. An electrode plate arranging step of arranging two electrode plates;
A singulation step of obtaining a plurality of thermoelectric conversion elements by singulation processing for cutting the electrode plate and the thermoelectric conversion prismatic rod on a surface orthogonal to the longitudinal direction of the thermoelectric conversion prismatic rod. Device manufacturing method. It is a manufacturing method of the thermoelectric conversion element according to claim 1,
After the preparation step, the electrodes are disposed on the upper surface and the lower surface of the thermoelectric conversion prismatic rod so as to straddle the P-type thermoelectric conversion prismatic rod and the N-type thermoelectric conversion prismatic rod. The manufacturing method of the thermoelectric conversion element which implements a board | substrate arrangement | positioning process. It is a manufacturing method of the thermoelectric conversion element according to claim 2,
A method for manufacturing a thermoelectric conversion element, wherein the joining member is solder or brazing material. It is a manufacturing method of the thermoelectric conversion element given in any 1 paragraph of Claims 1-3,
The singulation step further includes an electrode plate dividing step of dividing the electrode plate along the longitudinal direction of the thermoelectric conversion prismatic rod after the singulation processing,
In the electrode plate dividing step, only one of the first electrode plate and the second electrode plate is divided with respect to the dividing surface direction of the electrode plate. . It is a manufacturing method of the thermoelectric conversion element according to claim 4,
The said electrode plate division | segmentation process is a manufacturing method of the thermoelectric conversion element which implements a said 1st electrode plate and a said 2nd electrode plate alternately in the cross sectional view orthogonal to the longitudinal direction of the said thermoelectric conversion prismatic rod. A method for producing a thermoelectric conversion element according to any one of claims 1 to 5,
The method of manufacturing a thermoelectric conversion element further comprising a step of obtaining the thermoelectric conversion prismatic rod by dividing a semiconductor wafer made of a thermoelectric conversion material along one direction before the preparation step. It is a manufacturing method of the thermoelectric conversion element according to claim 6,
A method for manufacturing a thermoelectric conversion element, comprising: forming a diffusion prevention layer on at least one surface of the semiconductor wafer; and then dividing the semiconductor wafer. It is a manufacturing method of the thermoelectric conversion element according to claim 6 or 7,
A method for manufacturing a thermoelectric conversion element, wherein the semiconductor wafer has a quadrangular shape or a circular shape in plan view. A method for producing a thermoelectric conversion element according to any one of claims 1 to 8,
In the preparation step, the P-type thermoelectric conversion prismatic bar and the N-type thermoelectric conversion prismatic bar are alternately arranged. A method for producing a thermoelectric conversion element according to any one of claims 1 to 9,
The method for manufacturing a thermoelectric conversion element, wherein the electrode plate is a copper plate. It is a manufacturing method of the thermoelectric conversion element according to any one of claims 1 to 10,
In the preparation step, a method of manufacturing a thermoelectric conversion element, in which thin layer members are arranged alternately between the P-type thermoelectric conversion columnar body and the N-type thermoelectric conversion columnar body, and spaced apart from each other. . It is a manufacturing method of the thermoelectric conversion element according to claim 11,
The method for manufacturing a thermoelectric conversion element, wherein the thin layer member is a ceramic, a heat-resistant member, or a paper member.

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