JP2011238867A - Method for producing thermoelectric conversion module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a thermoelectric conversion module by collectively forming a large number of thermoelectric conversion material chips on a substrate by means of electrolytic deposition.SOLUTION: A method for producing a thermoelectric conversion module comprises the steps of: arranging electrodes on an insulation substrate 10; electrically interconnecting the electrodes via a conductive member 14 containing a resin support structure soluble in an organic solvent; covering the insulation substrate with a mask 16 which has openings only at portions corresponding to the positions on the electrodes where chips are to be formed; aligning a mold plate 18 having through-holes at the positions of the openings; performing electrolytic deposition in an electrolyte using the electrodes for cathode electrodes with conductive members intervening so that the through-holes are filled with a thermoelectric conversion material 32 to thereby form the chips; removing the mold plate, the mask and the conductive member successively for the P-type and N-type thermoelectric conversion materials to produce a P-type half body having the electrodes and P-type chips arranged on the insulation substrate and an N-type half body having the electrodes and N-type chips arranged on another insulation substrate; and combining the P-type half body with the N-type half body to produce a thermoelectric conversion module by combining a large number of thermoelectric conversion elements.

Description

  The present invention relates to a method for manufacturing a thermoelectric conversion module by forming a large number of chips of a thermoelectric conversion material on a substrate at once.

  The thermoelectric conversion material is an energy material that performs direct conversion between thermal energy and electric energy based on two basic thermoelectric effects, the Seebeck effect and the Peltier effect.

  Thermoelectric power generation devices using thermoelectric conversion materials have a simple structure, robustness, high durability, no moving parts, easy microfabrication, no maintenance, and reliability compared to conventional power generation technology There are many advantages such as high life, long life, no noise, no pollution and low temperature waste heat can be used.

  Compared to conventional compression cooling technology, thermoelectric cooling devices using thermoelectric conversion materials do not require chlorofluorocarbon, do not cause contamination, are easily downsized, have no moving parts, and do not generate noise. is there.

  Therefore, especially in recent years, energy and environmental issues have become more serious, such as aviation / space, national defense construction, geological and meteorological observation, medical hygiene, microelectronics, etc. Is expected to be put to practical use for a wide range of applications.

  Conventionally, P-type and N-type bulk thermoelectric conversion materials are manufactured by powder sintering and melting and solidification, and this is diced by machining to form several mm square P-type chips and N-type chips. A P-type chip and an N-type chip are arranged in a predetermined pattern on the top, and the chips on each substrate are joined so as to be sandwiched between both substrates, thereby forming a large number of thermoelectric conversion elements between the two substrates.

  In this specification, a small piece (for example, several mm square) of a thermoelectric conversion material itself is formed by joining a “chip” (thermoelectric conversion material chip) and a pair of P-type and N-type chips via electrodes. An “element” (thermoelectric conversion element) and an element group in which a large number of elements are combined are called a “module” (thermoelectric conversion module). In general, since the power generation amount of each element is small, a large number of elements are combined and put into practical use as an element group, that is, a module.

  Here, if an element pattern can be obtained directly by forming a large number of chips on a substrate by electrolytic deposition, the manufacturing cost of the element or module can be greatly reduced, which is very desirable.

  However, since the electrodes are discretely arranged on the substrate, it is not practical to collectively form each chip on each electrode by electrolytic deposition.

  That is, (1) In order to collectively form a large number of chips by electrolytic deposition, it is necessary to electrically connect discretely arranged electrodes on the substrate. (2) The conductive material for this electrical connection There was a problem that electrolytic deposition also occurred in the exposed portion, and (3) the conductive material for electrical connection had to be removed after use.

  Patent Document 1 discloses a method for producing a thermoelectric conversion material by electrolytic deposition. However, control of the crystal orientation of the thermoelectric conversion material formed by electrolytic deposition and a method of creating a multilayer film have been proposed, but a module can be manufactured by forming a large number of chips and elements in a batch from the thermoelectric conversion material. There is no disclosure about.

JP 2001-7408 A

  An object of the present invention is to provide a method for collectively manufacturing a thermoelectric conversion module including a plurality of thermoelectric conversion elements by forming a large number of thermoelectric conversion material chips on a substrate by electrolytic deposition.

To achieve the above object, the present invention is a method of manufacturing a thermoelectric conversion module in which a large number of thermoelectric conversion elements composed of a pair of thermoelectric conversion material chips of P type and N type are combined,
(1) arranging a large number of electrodes in a predetermined pattern on an insulating substrate;
(2) A step of disposing a conductive member including a resin support structure that is easily dissolved in an organic solvent so as to electrically join the multiple electrodes;
(3) A step of covering the insulating substrate with a mask having an opening only in a portion corresponding to a chip formation scheduled position on the electrode arranged on the insulating substrate;
(4) A mold plate having chip-shaped through-holes at a portion corresponding to the opening of the mask is aligned with each through-hole of the mold plate at each chip formation planned position of each electrode. Intimately fixing to,
(5) Electrodeposition is performed in the electrolytic solution with each electrode as a cathode electrode through the conductive member, whereby the chip-shaped through-holes of the mold plate are formed on the multiple electrodes on the insulating substrate. A step of filling a hole with the thermoelectric conversion material to form a chip of the thermoelectric conversion material on each electrode;
(6) removing the mold plate,
(7) a step of removing the mask, and (8) a step of removing the conductive member by dissolving the resin of the support structure of the conductive member with an organic solvent,
Are sequentially performed on the insulating substrate to form a half body of the thermoelectric conversion module in which the electrodes and the chips on the insulating substrate are arranged on the P-type and N-type thermoelectric conversion materials. A P-type half with an electrode and a P-type thermoelectric conversion material chip arranged thereon, and an N-type half with an electrode and an N-type thermoelectric conversion material chip arranged on another insulating substrate are prepared. And
A thermoelectric conversion in which a P-type thermoelectric conversion material chip and an N-type thermoelectric conversion material chip constitute a pair by combining the P-type half and the N-type half with their chip arrangement surfaces facing each other. Provided is a method for manufacturing a thermoelectric conversion module, characterized by manufacturing a thermoelectric conversion module in which a large number of elements are combined.

  According to the present invention, in the step (2), the conductive member including the resin support structure that is easily dissolved in the organic solvent is disposed so as to electrically join the multiple electrodes. ), A voltage is applied to all electrodes on the insulating substrate through the conductive member, and thermoelectric conversion material chips can be collectively formed on each electrode by electrolytic deposition. In step (8), the conductive member The conductive member can be removed by dissolving the resin of the supporting structure with an organic solvent, and the P-type and N-type halves obtained by performing this process on the P-type and N-type thermoelectric conversion materials are obtained. By combining them, a thermoelectric conversion module composed of a large number of thermoelectric conversion elements can be manufactured in a lump.

FIG. 1 shows a state in which electrodes are arranged on an insulating substrate according to a first embodiment of the method of the present invention. FIG. 2 shows a state in which conductive resin is filled between electrodes on an insulating substrate in the next step of FIG. 1 according to the first embodiment of the method of the present invention. FIG. 3 shows a state in which the electrode and the resin other than the chip formation scheduled positions are covered with a mask in the next step of FIG. 2 according to the first embodiment of the method of the present invention. FIG. 4 shows (1) a mold plate and (2) this for forming a chip by electrolytically depositing a thermoelectric conversion material on each electrode in the next step of FIG. 3 according to the first embodiment of the method of the present invention. The state which has arrange | positioned the mold board on the insulated substrate is shown. FIG. 5 shows the first embodiment of the method of the present invention, in the next step of FIG. 4, (1) is a state in which electrolytic deposition is performed on a substrate on which a mold plate is arranged, and (2) is a mold plate by electrolytic deposition. (3) is a cross-sectional view taken along line III-III in (2), and (4) is a nickel plating film on the exposed surface of the thermoelectric conversion material using another electrolytic solution. The state which formed is shown. FIG. 6 shows (1) a P-type half and (2) with the mold plate, mask and conductive member removed after electrolytic deposition in the next step of FIG. 5 according to the first embodiment of the method of the present invention. N-type half is shown. 7 shows a thermoelectric conversion module according to the first embodiment of the method of the present invention. In the next step of FIG. Shows the completed state. FIG. 8 shows a state in which, on the second embodiment of the method of the present invention, the electrode other than the chip formation scheduled position is masked with an insulating material as the next step of FIG. 2 of the first embodiment. FIG. 9 shows a state where an electroless plating film of Ni or the like is formed on the resin between the electrodes and on the electrode at the chip formation position in the next step of FIG. 8 in the second embodiment of the method of the present invention. The electrodes are electrically joined using an electroless plating film having a resin support structure as a conductive member. FIG. 10 shows a state in which, in the second embodiment of the method of the present invention, a chip is formed by electrolytically depositing a thermoelectric conversion material on all the electrodes through the electroless plating film in the next step of FIG. FIG. 11 shows a state in which the mold plate for chip formation is removed in the next step of FIG. 10 in the second embodiment of the present invention. FIG. 12 shows a state in which the mask between chips, the resin between electrodes, and the electroless plating film other than the chip formation position are removed in the next step of FIG. 11 in the second embodiment of the present invention.

[First Embodiment]
A first embodiment of the method of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 1, a large number of electrodes 12 are arranged in a predetermined pattern on an insulating substrate 10. Although (1) and (2) are P-type substrates and (3) and (4) are N-type substrates, P and N may be reversed. (1) is a plan view, (2) is a sectional view taken along line II-II in (1), (3) is a plan view, and (4) is a sectional view taken along line IV-IV in (2). The same applies to FIGS.

  Next, as shown in FIG. 2, a conductive member 14 including a resin support structure that is easily dissolved in an organic solvent is disposed so as to electrically join a large number of electrodes 12. In 1st Embodiment, the conductive member 14 can use the conductive resin which disperse | distributed the conductive polymer and the metal particle as a conductor in resin. In this case, the resin support structure is a resin as a dispersion medium, and the conductive member 14 as a whole is easily dissolved in an organic solvent, so that the entire conductive member 14 can be easily removed.

  Next, as shown in FIG. 3, the insulating substrate 10 is covered with an insulating mask 16 having openings 17 only at portions corresponding to the chip formation scheduled positions on the electrodes 12 arranged on the insulating substrate 10.

  Next, as shown in FIG. 4A, a mold plate 18 having chip-shaped through-holes 20 at portions corresponding to the openings 17 of the mask 16 is formed, and as shown in FIG. Each through-hole 20 of the mold plate 18 is aligned with each chip formation planned position, and fixed on the insulating substrate 10 with the fixing jig 22. A power supply lead 24 for electrolytic deposition is connected to the conductive member 14. A fixed assembly is indicated at 19.

  Next, as shown in FIG. 5A, electrolytic deposition is performed in the electrolytic solution 26 using the electrodes 12 as cathode electrodes via the conductive member 14. In the electrolytic solution 26, the fixed assembly 19 is disposed as a negative electrode, and a counter electrode 28 such as platinum is used as a positive electrode, and power is supplied from a DC power source 30.

  As a result, as shown in FIG. 5 (2) plan view and (3) cross-sectional view (line III-III in (2)), the chip shape of the mold plate 18 is formed on the numerous electrodes 12 on the insulating substrate 10. Each through hole 20 is filled with a thermoelectric conversion material, and a chip 32 of the thermoelectric conversion material is formed on each electrode 12.

  Desirably, as shown in FIG. 5 (4), an electrolytic plating film 34 of Ni or the like is formed on the surface of the chip 32 in the through hole 20 of the mold plate 18 in another electrolytic solution. Thereby, when a P-type semiconductor and an N-type semiconductor are combined using a bonding material, the bondability between the chip and the electrode can be improved.

  Next, as shown in FIG. 6, the mold plate 18, the mask 16, and the conductive member 14 are removed. The conductive member 14 can be easily removed by dissolving the resin of the support structure with an organic solvent.

  The steps of FIGS. 1 to 6 are sequentially performed to form thermoelectric conversion module halves 36 and 38 in which the electrodes 12 and the chips 32 thereon are arranged on the insulating substrate 10. That is, P-type and N-type thermoelectric conversion materials are used, and a P-type half 36 in which electrodes 12 and P-type thermoelectric conversion material chips 32 are arranged on one insulating substrate 10, and another insulating substrate 10. An electrode 12 and an N-type half body 38 on which the N-type thermoelectric conversion material chip 32 is arranged are manufactured.

  Next, as shown in FIG. 7, by combining the P-type half body 36 and the N-type half body 38 with their chip arrangement surfaces facing each other, the P-type thermoelectric conversion material chip, the N-type thermoelectric conversion material chip, Manufactures a thermoelectric conversion module 40 in which a large number of thermoelectric conversion elements configured in pairs are combined.

[Second Embodiment]
The second embodiment is different from the first embodiment in the conductive member that electrically joins the electrodes 12 together. That is, in the first embodiment, the conductive resin filling between the electrodes 12 is used as the conductive member. However, in the second embodiment, the resin filling between the electrodes 12 (conductive or non-conductive) is used. An electroless plating film such as Ni is formed and used as a conductive member. The conductive member used in the first embodiment is a conductive resin in which a conductive polymer or metal particles as conductors are dispersed in a resin as a support structure, whereas the conductive member used in the second embodiment is This is a structure in which a metal film as a conductor is electrolessly plated on a resin as a support structure. Therefore, in the second embodiment, the resin itself does not need to be conductive and may be non-conductive. The electroless plating film of metal such as Ni can function as a diffusion preventing layer between the electrode and the chip. When a conductive resin is used, an electroless plating film is not necessary for the electrode-to-electrode bonding function during electrolytic deposition, but the function of the electroless plating film as a diffusion preventing layer can be obtained in the first embodiment. This process is advantageous.

  The process of Embodiment 2 is demonstrated with reference to FIGS. 1-2, 4-5, 8-12, and 7 in this order.

  First, as in the first embodiment, a large number of electrodes 12 are arranged in a predetermined pattern on an insulating substrate 10 as shown in FIG.

  Next, as shown in FIG. 2, a resin support structure 14 ′ easily dissolved with an organic solvent is filled between the electrodes 12. The resin used in the second embodiment does not need to be conductive. A metal electroless plating film to be formed later may act as a support structure.

  Next, as shown in FIG. 8, the electrode 12 other than the chip formation planned position is covered with a mask 16 made of an insulating material. Although (1) and (2) are P-type substrates and (3) and (4) are N-type substrates, P and N may be reversed. (1) is a plan view, (2) is a sectional view taken along line II-II in (1), (3) is a plan view, and (4) is a sectional view taken along line IV-IV in (2). The same applies to FIG.

  Next, as shown in FIG. 9, an electroless plating film 52 of a metal such as Ni is formed on the chip formation planned position on the electrode 12 and the resin 14 '. 9 (2) and 9 (4), the conductive member 14 is composed of the resin 14 'and the electroless plating film 52. As shown in FIG. Many electrodes 12 are electrically connected through the electroless plating film 52 of the conductive member 14.

  Next, as in the first embodiment, the mold plate 18 shown in FIG. 4 (1) is aligned and fixed to the insulating substrate 10 as shown in FIG. 4 (2), as shown in FIG. 5 (1). Then, electrolytic deposition is performed in the electrolytic solution 26 with the electrode 12 as a cathode electrode through the conductive member 14 (particularly, the electroless plating film 52).

  Thereby, as shown in FIG. 10, the chip 32 of the thermoelectric conversion material is formed via the electroless plating film 52 at the chip formation planned position on the electrode 12. Although (1) is a P-type half and (2) is an N-type half, P and N may be reversed. (1) is a cross-sectional view at a position corresponding to line II-II in FIG. 9 (1), and (2) is a cross-sectional view at a position corresponding to line IV-IV in FIG. 9 (3). The same applies to FIGS.

  Next, as shown in FIG. 11, the mold plate 18 is removed.

  Next, as shown in FIG. 12, the mask 16, the resin 14 ′ between the electrodes 12, and the electroless plating film 52 remaining other than the chip position are removed. This state corresponds to the state of FIG. 6 of the first embodiment, and in the next step, as shown in FIG. 7 of the first embodiment, the P-type half 36 and the N-type half 38 are connected to the chip formation side. The thermoelectric conversion module 40 is completed by facing each other and overlapping and joining. In the second embodiment, the electroless plating film 52 such as Ni remaining between the electrode 12 and the chip 32 functions as a diffusion prevention layer between the electrode 12 and the chip 32.

  Examples of the first embodiment of the present invention will be described.

  A 200 μm thick copper plate is soldered on the alumina substrate 10. This copper plate is patterned on the thermoelectric conversion element electrode 12 by etching. As a result, as shown in FIG. 1, P-type substrates (1) (2) and N-type substrates (3) (4) on which electrodes 12 are arranged for P-type chip formation and N-type chip formation are prepared. . Instead of the alumina substrate 10, ceramics such as magnesia, silicon nitride, and silicon carbide, and insulating materials such as resin materials can be used. As a material of the electrode 12, metal materials such as Al, Fe, Ag, Au, and stainless steel can be used instead of copper (Cu).

  Next, as shown in FIG. 2, a conductive resin 14 is filled between a large number of electrodes 12, and all the electrodes 12 are electrically connected and integrated. As the conductive resin 14, a resin obtained by mixing and dispersing a conductive polymer such as polyacetylene, polyaniline, polypyrrole, or a metal filler in a resin as a support structure can be used.

  Next, as shown in FIG. 3, the alumina substrate 10 is covered with an insulating mask 16 having an opening 17 only at a portion corresponding to a chip formation planned position on the electrode 12.

  The mask 16 can be made of polyimide, epoxy, acrylic, phenolic resin, or the like. A method of applying an ink resist material by screen printing, a method of using a pre-patterned dry film, or a photosensitive photo. It can be formed by a method of curing an exposed portion with a resist and washing away an uncured portion.

  Next, as shown in FIG. 3, the insulating substrate 10 is covered with an insulating mask 16 having openings 17 only at portions corresponding to the chip formation scheduled positions on the electrodes 12 arranged on the insulating substrate 10.

  Next, the mold plate 18 shown in FIG. 4A is closely fixed on the insulating substrate 10 as shown in FIG. The mold plate 18 is produced by forming a through hole 20 having a chip shape and dimensions (for example, 2 mm square) in a resin material or the like. The resin material or the like is preferably a highly peelable material such as PTFE, but is not limited thereto, and other resins and ceramics can also be used. Although a rectangular parallelepiped is illustrated as the shape of the chip (through hole), other shapes may be used.

  Next, electrolytic deposition is performed as shown in FIG. 5 (1), and chips 32 are formed in the through holes 20 as shown in FIGS. 5 (2) and (3). The electrodeposition assembly 19 is a negative electrode, and a noble metal such as platinum is a positive electrode. By energizing the conductive member 14 made of conductive resin on the substrate 10, the chips 32 are formed on all the electrodes 12 not covered with the mask 16. The P-type chip 32 and the N-type chip 32 are formed on different substrates 10.

As an example, when producing a thermoelectric conversion module of a BiTe thermoelectric conversion material, a BiTe system is obtained by performing electrolytic deposition at a constant potential using a nitric acid solution in which Bi ₂ O ₃ and TeO ₂ are dissolved as the electrolytic solution 26. A chip 32 of thermoelectric conversion material can be formed. The composition ratio of Bi and Te can be adjusted by the electrodeposition potential to make a P-type chip and an N-type chip separately. P-type and N-type composition adjustments can also be made by dissolving metal ions as dopants in the electrodeposition bath. If the electrodeposition is performed by changing the combination of other metal salts and the electrolytic solution 26, the chips 32 of thermoelectric conversion materials having various compositions can be formed.

  If necessary, a protective film 34 such as a Ni electrolytic plating film may be formed on the top surface of the formed chip 32 as shown in FIG.

  Next, as shown in FIG. 6, the mold plate 18, the mask 16, and the conductive member 14 are removed. This is performed by removing the mold plate 18 from the chip 32 on the substrate 10 and then removing the mask 16 and the conductive resin 14 by dissolving them in an organic solvent such as toluene or xylene.

  Next, as shown in FIG. 7, the P-type half 36 and the N-type half 38 are bonded to each other with their chip arrangement surfaces facing each other, and the thermoelectric conversion module 40 is manufactured.

  For this purpose, first, a solder paste (not shown) is applied to the top surface of the chip 32 (on the Ni protective film 34 in this example) by screen printing. Next, using the alignment jig, the top surface of the P-type chip 32 of the P-type half 36 and the electrode of the N-type half 38 are aligned, and the top surface of the N-type chip 32 of the N-type half 38 And the electrode of the P-type half 36 are aligned and fixed. Next, the fixed assembly is heat-treated at a temperature higher than the melting temperature of the solder to bond each half chip 32 to the other half electrode 12. As a result, the thermoelectric conversion module 40 in which a large number of thermoelectric conversion elements configured by forming pairs of P-type thermoelectric conversion material chips and N-type thermoelectric conversion material chips is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the method of collectively manufacturing the thermoelectric conversion module which consists of many thermoelectric conversion elements by forming many thermoelectric conversion material chips | tips collectively on a board | substrate by electrolytic deposition is provided.

DESCRIPTION OF SYMBOLS 10 Insulation board | substrate 12 Electrode for thermoelectric conversion elements 14 Conductive member 14 'Support structure 16 Mask 17 Opening 18 Mold plate 20 Through hole 22 Fixing jig 24 Feeding lead 26 Electrolytic solution 28 Counter electrode 30 DC power supply 32 Chip (chip of thermoelectric conversion material)
34 Electrolytic plating film (protective film)
36 P-type half 38 N-type half 40 Thermoelectric conversion module 52 Electroless plating film

Claims (3)

A method of manufacturing a thermoelectric conversion module in which a large number of thermoelectric conversion elements composed of a pair of P-type and N-type thermoelectric conversion material chips are combined,
(1) arranging a large number of electrodes in a predetermined pattern on an insulating substrate;
(2) A step of disposing a conductive member including a resin support structure that is easily dissolved in an organic solvent so as to electrically join the multiple electrodes;
(3) a step of covering the insulating substrate with an insulating mask having an opening only in a portion corresponding to a chip formation scheduled position on the electrode arranged on the insulating substrate;
(4) A mold plate having chip-shaped through-holes at a portion corresponding to the opening of the mask is aligned with each through-hole of the mold plate at each chip formation planned position of each electrode. Intimately fixing to,
(5) Electrodeposition is performed in the electrolytic solution with each electrode as a cathode electrode through the conductive member, whereby the chip-shaped through-holes of the mold plate are formed on the multiple electrodes on the insulating substrate. A step of filling a hole with the thermoelectric conversion material to form a chip of the thermoelectric conversion material on each electrode;
(6) removing the mold plate,
(7) a step of removing the mask, and (8) a step of removing the conductive member by dissolving the resin of the support structure of the conductive member with an organic solvent.
Are sequentially performed on the insulating substrate to form a half body of the thermoelectric conversion module in which the electrodes and the chips on the insulating substrate are arranged on the P-type and N-type thermoelectric conversion materials. A P-type half with an electrode and a P-type thermoelectric conversion material chip arranged thereon, and an N-type half with an electrode and an N-type thermoelectric conversion material chip arranged on another insulating substrate are prepared. And
A thermoelectric conversion in which a P-type thermoelectric conversion material chip and an N-type thermoelectric conversion material chip constitute a pair by combining the P-type half and the N-type half with their chip arrangement surfaces facing each other. A method for producing a thermoelectric conversion module, comprising producing a thermoelectric conversion module in which a large number of elements are combined. In claim 1,
A method of manufacturing a thermoelectric conversion module, wherein a conductive resin is used as a conductive member including a resin support structure that is easily dissolved in an organic solvent in the step (2). In claim 1,
Instead of the above steps (2) to (3), the following steps:
As a support structure of a resin that is easily dissolved in an organic solvent, after filling the space between the electrodes with a resin, the chip formation planned position on each electrode is covered with an insulating mask other than the chip formation planned position on each electrode. And a process for forming the conductive member by forming a conductive film on the support structure of the resin by electroless plating.

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