JP2015095610A - Peltier element - Google Patents

Abstract

Kind Code: A1 A Peltier element in which the number of manufacturing steps is reduced and the bonding strength between an electrode and a thermoelectric material body is improved is provided. A Peltier element (1) in which P-type and N-type thermoelectric material bodies (2, 3) are alternately connected via electrodes (4), the electrodes are formed of a conductive paste, and the P-type and N-type thermoelectric Said element, wherein the body of material is embedded in the electrode. [Selection drawing] Fig. 1

Description

  The present invention relates to a Peltier element, and more particularly, by using a specific configuration for joining an electrode and an electrode to a thermoelectric material body, high joining between an electrode-P type and an N-type thermoelectric material body even if the number of manufacturing steps is small. The present invention relates to a Peltier element having strength.

  The Peltier element is an element using the Peltier effect, and has a function of controlling the temperature by converting electric power into heat energy by passing a current between the elements. Such a Peltier element can reduce the ambient temperature by utilizing the endothermic effect when a current is passed through a P-type or N-type thermoelectric material body (made of a thermoelectric material, sometimes called a semiconductor). Therefore, it is highly useful as a solid-state cooling device that does not use a refrigerant such as Freon.

On the other hand, conventional Peltier elements are usually limited in use due to the connection configuration between the electrode and the thermoelectric material, such as being required to be used in stationary equipment or limited in use temperature. Therefore, there is a demand for a Peltier element having a joining configuration of an electrode and a thermoelectric material body that is less subject to the above limitation.
For this reason, various investigations have been made on the electrode or the bonding configuration of the electrode and the thermoelectric material in the Peltier element.
On the other hand, there has been proposed a technique presumed to be applicable to a change in the electrode Peltier element or the bonding configuration between the electrode and the thermoelectric material body.

  For example, in Patent Document 1, in order to widen the usable temperature range limited to below the melting point of solder in a conventional thermoelectric conversion element using solder, a sintered body formed from a thermoelectric conversion material, and this sintering A heating surface on one side of the body and a pair of electrodes attached to the other cooling surface, and a conductive paste in which metal fine particles are dispersed is applied to the heating surface and the cooling surface, and baked to form the particles A thermoelectric conversion element provided with an electrode having a thickness of about 1 to 10 μm is described. As a specific example, a thermoelectric conversion element in which a silver paste is applied and baked only on both surfaces of a sintered body is shown. Has been.

  Patent Document 2 discloses an insulating substrate, a wiring electrode including a block arrangement electrode formed on the insulating substrate, and a plurality of p-type semiconductors and n-type semiconductors arranged at predetermined positions of the wiring electrode. Solder the thermoelectric element electrically connected in series, the block electrode arranged on the block arrangement electrode, and the block arrangement electrode and the opposed surface of the block electrode, and the entire circumference of the end of the opposed surface A thermoelectric conversion module is described in which a solder layer is formed so as to cover the surface, and the bonding between the block electrode of the thermoelectric element and the solder layer is strengthened.

  Further, in Patent Document 3, first and second green sheet laminates, and conductive pastes are printed on these laminates to form first and second spare electrodes, respectively. A thermoelectric module is formed by arranging a thermoelectric element on top and firing each laminate to form a ceramic substrate, and joining the ceramic substrate and the electrode, and the electrode and the thermoelectric element. A thermoelectric module in which a thermoelectric element is bonded to the surface of the formed electrode is shown.

  However, if these known techniques are applied to Peltier elements as they are, for example, a thermoelectric module in which a thermoelectric element is bonded to the surface of an electrode has low bonding strength and high bonding strength, but the number of manufacturing processes is large. Therefore, it is difficult to obtain a Peltier device having a small bonding strength and high bonding strength between the electrode and the thermoelectric material.

JP 2009-081252 A JP 2011-040787 A JP 2012-044133 A

  Accordingly, an object of the present invention is to provide a Peltier element in which the number of manufacturing steps is small and the bonding strength between an electrode and a thermoelectric material body is improved.

The present invention relates to a Peltier element in which P-type and N-type thermoelectric material bodies are alternately connected via electrodes.
The electrode is formed of a conductive paste;
The present invention relates to the element, wherein the P-type and N-type thermoelectric material bodies are embedded in electrodes.

  According to the present invention, it is possible to obtain a Peltier device having a small number of manufacturing steps and improved bonding strength between the electrode and the thermoelectric material body.

FIG. 1 is a partially enlarged schematic view of a Peltier element according to an embodiment of the present invention. FIG. 2 is a process diagram showing an example of a method for manufacturing a Peltier device according to an embodiment of the present invention. FIG. 3 is a partially enlarged schematic view of a conventional Peltier element. FIG. 4 is a process diagram showing an example of a method for manufacturing a conventional Peltier element. FIG. 5 is a flowchart of the confirmation test method in the embodiment. FIG. 6 is a partially enlarged schematic view for explaining the Peltier element obtained in Example 1. FIG. 7 is a partially enlarged schematic view for explaining the Peltier element obtained in Comparative Example 1. FIG. 8 is a partially enlarged schematic view for explaining the Peltier element obtained in Comparative Example 2. FIG. 9 is a graph showing a comparison of the bonding strengths of the Peltier elements obtained in the examples and comparative examples.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
According to the Peltier element 1 of the embodiment of the present invention, as shown in FIG. 1, the P-type thermoelectric material body 2 and the N-type thermoelectric material body 3 are alternately arranged via the conductive paste electrodes 4 formed of the conductive paste. The electrode 4 is fixed by insulating substrates 5 and 6, and the P-type thermoelectric material body 2 and the N-type thermoelectric material body 3 are embedded in the electrode 4. It is possible to obtain a Peltier element having a small number and improved bonding strength between the electrode and the thermoelectric material.

For example, as shown in FIG. 2, the Peltier device 1 according to the embodiment of the present invention includes one process: thermoelectric material synthesis → ingotization → slicing → dicing, and the other process: substrate cutting → conductive paste application. Using the member produced in the process, a Peltier element can be obtained by a manufacturing method consisting of a post process: chip electrode mount → firing → Peltier element.
According to the above manufacturing method, the surface treatment in the manufacturing method of the metal electrode, the solder, and the conventional Peltier element is not necessary, and the number of manufacturing steps can be reduced and the cost can be reduced.

  On the other hand, in the conventional Peltier element 10, for example, as shown in FIG. 3, P-type thermoelectric material bodies 2 and N-type thermoelectric material bodies 3 are alternately connected via metal electrodes 7, and the electrodes 7 are insulated. The P-type thermoelectric material body 2 and the N-type thermoelectric material body 3 are fixed by substrates 5 and 6 and are joined by plating and soldering 8.

For example, as shown in FIG. 4, the conventional Peltier element 10 has one process: thermoelectric material synthesis → ingotization → slicing processing → surface treatment → dicing, and the other process: substrate cutting → electrode bonding → etching wiring → surface treatment. → Peltier element can be obtained by a manufacturing method consisting of post-process: chip electrode mounting → reflow → Peltier element using the member produced in both processes of solder application. The reflow in the above process is a process performed for the purpose of heating and joining the solder.
In the manufacturing method described above, since various materials are used and bonded to each other, the number of manufacturing processes is large.

There is no restriction | limiting in particular as a thermoelectric material in the embodiment of this invention, For example, at least 2 selected from Bi, Sb, Ag, Pb, Ge, Cu, Sn, As, Se, Te, Fe, Mn, Co, Si Examples thereof include materials containing elements of more than one species, for example, BiTe-based materials or crystals of CoSb ₃ compounds containing Co and Sb as the main component and containing elements other than Co and Sb, such as transition metals. Examples of the transition metal include Cr, Mn, Fe, Ru, Ni, Pt, and Cu. As the thermoelectric material, (Bi, Sb) ₂ (Te, Se) ₃ system, Bi ₂ Te ₃ system, (Bi, Sb) Te system, Bi (Te, Se) system, CoSb ₃ system, PbTe system, SiGe system Any of these can be mentioned preferably. Of the transition metals, a thermoelectric material containing Ni can give an N-type thermoelectric material, and a thermoelectric material containing Fe, Sn, or Ge in the composition can give a P-type thermoelectric material.

  Examples of the conductive paste constituting the electrode in the embodiment of the present invention include any known conductive paste, and usually contain particles having high electrical conductivity as a base resin and a filler. Examples of the particles having high air conductivity include Cu, Fe, Ag, and Ni, and Cu or a copper alloy is particularly preferable. Examples of the base resin include an epoxy resin, an acrylic resin, and a silicone resin.

  Examples of the insulating substrate in the embodiment of the present invention include any insulating substrate, such as an alumina substrate, a glass substrate, an aluminum nitride (AlN) substrate, and preferably an alumina substrate.

Examples of the present invention will be described below.
The following examples are for confirming the effects of the embodiments of the present invention.

In the following examples, experiments were performed according to the flowchart shown in FIG.
In the flowchart, each step (1) to (4) was performed according to the following procedure.
(1) A conductive paste is applied to an alumina substrate to a thickness of 2 mm (after heat treatment).
(2) A jig is placed on the conductive paste so that one end of the chip is parallel to the substrate.
In the examples, a load was applied from above until the thermoelectric material body sank 1 mm.
(3) Heat treatment (150 ° C. × 10 minutes) is performed to sinter and bond the conductive paste.
(4) The substrate and the chip were fixed to a tensile tester, a tensile test (tensile speed: 0.5 mm / min) was performed, the tensile strength was measured, and the bonding strength was evaluated.

Details of the materials used in each of the above steps are as follows.
Details of material Thermoelectric material: BiSbTe 1.5 × 2.0 × 10.0 mm
Conductive paste: Hitachi Chemical Co., Ltd. CP-300 (Curing conditions: 150 ° C./10 minutes)
Substrate: Alumina Thickness 635μm 32x40mm

The details of the apparatus used in each of the above steps are as follows.
Detailed heat treatment furnace: Yamato Scientific Co., Ltd. Constant temperature drying furnace DN63
Tensile tester: Shimadzu Corporation Shimadzu Autograph AG-5kNXplus

Example 1
A tensile test sample shown in FIG. 6 was prepared according to the above-described process.
About the obtained sample, in order to evaluate the influence on the joining strength by the difference in a joining state, the tensile fracture strength was measured.
The obtained result is shown in FIG. 9 together with the result of the comparative example.

Comparative Example 1
A tensile test sample shown in FIG. 7 was prepared according to the conventional process.
About the obtained sample, in order to evaluate the influence on the joining strength by the difference in a joining state, the tensile fracture strength was measured.
The obtained results are shown in FIG. 9 together with other results.

Comparative Example 2
In accordance with a conventional process, an aluminum nitride (AlN) substrate (also referred to as a DBA substrate) was used as a substrate to prepare a tensile test sample having the configuration shown in FIG.
About the obtained sample, in order to evaluate the influence on the joining strength by the difference in a joining state, the tensile fracture strength was measured.
The obtained results are shown in FIG. 9 together with other results.

From FIG. 9, the end of the thermoelectric material body is embedded in the electrode and bonded to the end face and side surface of the thermoelectric material body, thereby improving the adhesion between the thermoelectric material body and the electrode and obtaining high bonding strength. Is understood.
Therefore, according to the Peltier device of the embodiment of the present invention, it is possible to realize a joining strength equivalent to that of solder without using solder, and as a result, the number of types of materials and the number of manufacturing steps are small and the cost is low. It will be understood that it is possible to manufacture a Peltier element having the same reliability as a conventional Peltier element.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesiveness of a thermoelectric material body and an electrode improves, joining strength is high, and a Peltier device with few materials and manufacturing processes is provided.

1 Peltier device according to an embodiment of the present invention 2 P-type thermoelectric material (P-type semiconductor)
3 N-type thermoelectric material (N-type semiconductor)
4 Conductive Paste Electrode 5 Insulating Substrate 6 Insulating Substrate 7 Metal Electrode 8 Plating, Solder 10 Conventional Peltier Device

Claims (1)

In a Peltier device in which P-type and N-type thermoelectric material bodies are alternately connected via electrodes,
The electrode is formed of a conductive paste;
The element, wherein the P-type and N-type thermoelectric material bodies are embedded in electrodes.

Images