JPH11135844A - Manufacture of thermoionic module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve simplification of a manufacturing process of a thermoionic module and a stabilization of quality, and to achieve improvement in the heat transfer efficiency with a heat exchanger to be attached. SOLUTION: Holes for containing thermoionic elements are formed into a grid shape at specified intervals in a flat substrate 11, which is formed from electrically insulating material. From the hole wherein a thermoionic electric element that is to become a base end of an electrically serial connection is contained, to the hole wherein the thermoionic element that becomes a terminating end of the electrically serial connection, a partition part is formed by the neighboring holes and holes. For the partition part, recess parts having the depth approximately in correspondence with the thickness of the electrode plate of the thermoionic element are alternately formed vertically. In the holes of the base body, P-type thermoionic elements 21 and N-type thermoionic elements 22 are arranged alternately. A brazing filler metal 25 is filled in the recess part of the partition part of the base body to obtain the electrically serial connection. The neighboring electrode plates holding the recess parts are alternately brazed. This method comprises these processes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a thermoelectric module.

[0002]

2. Description of the Related Art A thermoelectric module is formed by joining a p-type thermoelectric element and an n-type thermoelectric element via an electrode plate so as to be electrically connected in series. When a current flows between the junctions, heat is absorbed or heat is generated depending on the direction of the current. The former property is called the Seebeck effect, and has been developed for thermoelectric power generation, such as power generation by waste heat from refuse incinerators,
The latter property is called a Peltier effect, and is widely used for thermoelectric cooling such as cooling of a thermostat or an electronic device in a semiconductor manufacturing process.

[0003] As a typical example of a thermoelectric module, as shown in FIG.
There is a structure in which a p-type thermoelectric material (90) and an n-type thermoelectric material (91) are electrically connected in series via an electrode plate (98). The method of manufacturing this thermoelectric module will be described. As shown in FIG. 9, Ni plating layers (92) and (92) on both sides of a p-type thermoelectric material (90) and an n-type thermoelectric material (91) for improving the bonding property. ) Is applied, and solder plating layers (94) and (94) are further applied on the Ni plating layer. Next, the electrode (98) is formed by directly patterning Cu on the electrically insulating ceramic substrate (96). After the p-type thermoelectric material (90) and the n-type thermoelectric material (91) are alternately arranged on the Cu electrode (98) of the ceramic substrate (96) corresponding to the patterning position, these thermoelectric materials (9
0) On the (91), a ceramic substrate (96) on which a Cu electrode (98) is patterned is placed. When this is placed in a heating device and heated, the solder (94) (94) melts and the thermoelectric material
(90) (91) Ni plating layer (92) (92) and ceramic substrate (9
6) The Cu electrodes (98) and (98) of (96) are joined.

[0004]

In the conventional manufacturing method, p
Since the type and n-type thermoelectric material and the electrode were joined by soldering when assembling the thermoelectric module, if the size and surface condition of the thermoelectric material were not uniform, poor connection between the thermoelectric element and the solder or There have been inconveniences such as poor conductivity and loss of flatness of the thermoelectric module. In this case, if there is a poor connection between the thermoelectric element and the solder, it is impossible to partially repair the thermoelectric element. Therefore, the thermoelectric module assembled must be discarded. In the case of a thermoelectric module having a structure in which a thermoelectric element is sandwiched between ceramic plates, the ceramic plate must be thick enough to secure the rigidity of the thermoelectric module. There is a disadvantage that the heat transfer efficiency between the heat absorbing block and the heat radiating block is reduced.

An object of the present invention is to provide a method of manufacturing a thermoelectric module which solves the above-mentioned disadvantages by using a thermoelectric element in which a thermoelectric material and an electrode plate are integrally joined in advance.

[0006]

In order to achieve the above-mentioned object, the invention described in claim 1 is directed to a plate-like base formed of an electrically insulating material, and a hole for accommodating a thermoelectric element. Are opened in a lattice at predetermined intervals, and are adjacent from the hole in which the thermoelectric element serving as the base end of the electric series is accommodated to the hole in which the thermoelectric element serving as the terminal end of the electric series is accommodated With respect to the partition formed by the holes and the holes, recesses having a depth substantially equivalent to the thickness of the electrode plate of the thermoelectric element are alternately formed on the upper and lower sides, and the p-type thermoelectric element and the n-type A step of arranging the thermoelectric elements alternately, filling the recesses of the partitioning portions of the base with a brazing material so as to be electrically in series, and alternately brazing the electrode plates adjacent to each other across the recess. It is characterized by:

[0007] The invention described in claim 2 is characterized in that a copper material is arranged in a recess of the partition before filling with the brazing material.

[0008] The invention described in claim 3 is characterized in that after the brazing step, a step of surface grinding or cutting the surfaces of the base and the electrode plate is provided.

The invention described in claim 4 is characterized in that the method further comprises, after the surface grinding step, a step of applying an electrical insulating layer to the surfaces of the base and the electrode plate.

[0010]

According to the first aspect of the present invention, since a thermoelectric element in which a thermoelectric material and an electrode plate are integrally joined in advance is used, workability in a thermoelectric module manufacturing process is improved. In addition, since the bonding between the electrode plates is performed by filling the recess of the partition with a brazing material such as solder, poor bonding or poor conductivity hardly occurs, even if such inconvenience occurs. It is sufficient to fix only the defective part.

In the invention described in claim 2, since a copper material having excellent conductivity is interposed between the electrode plates,
It is possible to reduce the electric resistance between the thermoelectric elements as compared with the case of simple solder joining.

According to the third aspect of the present invention, the smoothness and flatness of the surfaces of the base and the electrode plate can be improved, and the thickness of the thermoelectric module can be precisely adjusted. The degree of adhesion between the heat absorbing block and the heat radiating block of the exchange device can be improved, and the heat transfer efficiency between the thermoelectric element and the heat conductive member for heat absorption and heat radiation can be improved.

According to the fourth aspect of the present invention, since the electric insulating layer is previously formed on the surfaces of the base and the electrode plate,
It can be directly attached to a heat exchanger made of metal with good thermal conductivity.

[0014]

Embodiments of the present invention will be described below. First, the assembled thermoelectric module will be described. Referring to FIG. 2, a rectangular flat base (1
In 1), there is a hole at a predetermined interval to accommodate the thermoelectric material.
(12) is formed in a lattice shape, and a partition (13) is formed by the adjacent holes (12) and the holes (12). It should be understood that the number of holes is set based on the number of thermoelectric elements according to the desired power generation capacity, and is not limited to the illustrated embodiment. The substrate (11) is made of an electrically insulating material such as ceramics or cement. As a desirable material for the substrate (11), for example, cordierite (2MgO.2A) is used.
l ₂ O ₃ .5SiO ₂ ).

In the partition (13), recesses (14) having a depth substantially equivalent to the thickness of the electrode plate (18) of the thermoelectric element are formed alternately in the upper and lower directions. The recess (14) is a space necessary for filling a brazing material (25) for connecting adjacent electrode plates.

The p-type thermoelectric element (21) has a p-type thermoelectric material (16) previously bonded between a pair of opposed electrode plates (18), (18), and the n-type thermoelectric element (22) has A pair of opposing electrode plates (18) (1
An n-type thermoelectric material (17) is previously bonded between 8). These thermoelectric elements are manufactured by placing an electrode plate in a mold, filling a thermoelectric material powder thereon, placing the electrode plate, and hot pressing. As an example of a p-type thermoelectric material, (Bi ₂ Te ₃ ) _{1 -x} (Sb ₂ Te ₃ ) _x where x is 0.7
(Bi ₂₎
Te ₃ ) _1-x (Bi ₂ Se ₃ ) _x where x is 0.05 to 0.15
However, the present invention is not limited to these. The composition ratio is a ratio of the number of atoms. The electrode plate is C
Although a u-plate is used, in order to improve the bonding property with the thermoelectric material, it is more preferable to use Ni plating or Mo or Ti vapor-deposited on the surface in contact with the thermoelectric material. desirable.

In the embodiment of the thermoelectric module shown in FIG.
, The p-type thermoelectric element (21) at the position 1-1 is the base end of the electric series, the n-type thermoelectric element (22) at the position 6-6 is the end of the electric series, From the type thermoelectric element (21),
Up to the thermoelectric element (22) at the position 6-6, the adjacent upper electrode plates (18) (18) (18) through the brazing material (25) such as solder filled into the recess (14) of the base (11). ) The lower electrode plates (18) and (18) are alternately brazed to form a zigzag electrical series circuit. More specifically, p at position 1-1
The type thermoelectric element (21) and the n-type thermoelectric element (22) at the position 1-2 are arranged between the lower electrode plates (not shown in FIG. 1), and the n-type thermoelectric element (22) at the position 1-2 and the position 1-3. In the p-type thermoelectric element (21), the upper electrode plates are brazed. Further, the n-type thermoelectric element (22) at the position 1-6 and the p-type thermoelectric element (21) at the position 2-1 are located between the upper electrode plates, and the p-type thermoelectric element (21) at the position 2-1 and the position 2-2.
The lower electrode plates (not shown in FIG. 1) of the n-type thermoelectric element (22) are soldered.

The base (11) has lead wires (32) (3
Grooves (34) and (34) for accommodating 2) are opened, and the lead wires (32) and (32) provided in the grooves are positioned at positions 1 through
1 p-type thermoelectric element (21) (the base end of the electric series) and position 6-
6. Electrode plate (18) of n-type thermoelectric element (22) (terminal in electrical series)
And are electrically connected to all the thermoelectric elements.

Next, a process of assembling the thermoelectric module according to the present invention will be described. First, a substrate (11) (FIG. 2) formed in a rectangular flat plate shape from an electrically insulating material such as ceramics and having holes (12) for accommodating thermoelectric elements formed in a lattice at predetermined intervals. (a) and (b)) are prepared. In FIG. 2A, a hole (12) at a position indicated by 1-1 is a hole for accommodating a thermoelectric element serving as a base end of an electric series, and a hole (12) at a position indicated by 6-6 is , A hole for accommodating a thermoelectric element serving as a terminal of an electrical series.

There are two types of thermoelectric elements, p-type and n-type.
The p-type thermoelectric element (21) has a p-type thermoelectric material (16) bonded between a pair of opposed electrode plates (18) and (18), and the n-type thermoelectric element (22) has a pair of opposed electrode plates (18). The n-type thermoelectric material (17) is joined between the () and (18).

The p-type thermoelectric element (21) and the n-type thermoelectric element (22)
With respect to the substrate (11) prepared as described above,
A zigzag path from (12) to the hole (12) at position 6-6 is alternately arranged in the holes (see FIGS. 3 and 4).

Next, a recess (14) formed in the partition (13) of the base (11) is filled with a conductive brazing material (25) such as solder, and the adjacent lower electrode plate (18) is filled. (18) The adjacent upper electrode plates (1
8) (18) Soldering and joining (see FIG. 5). Thereby, the p-type thermoelectric element arranged in the hole (12) at the position 1-1
From (21) to the n-type thermoelectric element (22) arranged in the hole (12) at the position 6-6, all the thermoelectric elements are electrically connected in series.

The surfaces of the base and the electrode plate are desirably subjected to surface finishing by surface grinding or cutting as shown by a two-dot chain line in FIG. 6 in order to improve smoothness. The thermoelectric module is used in close contact with a heat absorbing block and a heat radiating block formed of a metal such as copper, which has excellent thermal conductivity, through a member made of an electrically insulating material such as alumina. In addition, the smoothness of the surface of the electrode plate is important for improving the heat exchange efficiency by improving the contact state with the block.

A layer (36) of an electrically insulating material such as alumina may be formed on the surfaces of the base (11) and the electrode plate (18) in advance, for example, by thermal spraying (FIG. 7). reference). By providing the electrically insulating layer (36) in advance, there is an advantage that attachment to the heat absorption and heat dissipation block can be performed more easily.

In the thermoelectric module manufactured as described above, the lead wire (32) for connecting the device is inserted into the groove (34) of the base (11), and a conductive brazing material such as solder is used. It is respectively joined to each electrode plate of the thermoelectric element which becomes a base end and an end of electric series.

Before the solder is filled in the recess (14) of the partition (13), a copper material (not shown) may be put in, and the electrode plates may be soldered together with the copper material. . Since copper has excellent conductivity, there is an advantage that the electric resistance between thermoelectric elements can be reduced. The copper material can be in any form, such as wire or powder.

It should be understood that the present invention is not limited to the configuration of the above-described embodiment, and that various modifications are possible within the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state where a thermoelectric module is assembled.

FIG. 2 (a) is a plan view of a base of a thermoelectric module, and FIG.
It is sectional drawing which follows the AA 'line of (a).

FIG. 3 is an explanatory view of a step of arranging a thermoelectric element in a hole of a base.

FIG. 4 is a cross-sectional view showing a state where a thermoelectric element is arranged in a hole of a base.

FIG. 5 is a cross-sectional view showing a state where an electrode plate of the thermoelectric element is soldered.

FIG. 6 is an explanatory view of a step of performing surface grinding or cutting on a base and an electrode plate.

FIG. 7 is a cross-sectional view of an embodiment in which an electric insulating layer is formed on the surfaces of a base and an electrode plate.

FIG. 8 is an exploded perspective view of a conventional thermoelectric module.

FIG. 9 is a diagram illustrating a method for manufacturing a conventional thermoelectric module.

[Explanation of symbols]

 (1) Thermoelectric module (11) Base (12) Hole (13) Partition (14) Recess (18) Electrode plate (21) P-type thermoelectric element (22) N-type thermoelectric element (25) Raw material (36) Electrical insulation layer

Claims (4)

[Claims] 1. A p-electrode between a pair of opposed electrode plates (18) (18).
P-type thermoelectric element (21) to which the type-type thermoelectric material (16) is joined, and an n-type thermoelectric element (to which an n-type thermoelectric material (17) is joined between a pair of opposed electrode plates (18) and (18)) 22) are arranged alternately in a grid pattern, and a method for producing a thermoelectric module (1) connected so that the whole is electrically in series, comprising a flat plate formed of an electrically insulating material. Substrate (11)
At the same time, holes (12) for accommodating thermoelectric elements are opened in a grid at predetermined intervals, and a thermoelectric element serving as a terminal for electrical series is opened from a hole for accommodating a thermoelectric element serving as a base end of electric series. Until the hole in which the element is accommodated, the recess (14) having a depth approximately equivalent to the thickness of the electrode plate of the thermoelectric element is alternately arranged up and down with respect to the partition (13) formed by the adjacent holes and the hole. Formed on a substrate (11)
In the hole (12), a p-type thermoelectric element (21) and an n-type thermoelectric element (22)
Are alternately arranged, and the base (11) is electrically connected in series.
Fill the brazing material (25) into the recess (14) of the partition (13) of
4) A method for producing a thermoelectric module, comprising a step of alternately brazing electrode plates (18) and (18) adjacent to each other with the interposition therebetween. 2. A partition (13) before filling with a brazing material (25).
The method for manufacturing a thermoelectric module according to claim 1, further comprising a step of arranging a copper material in the recess (14). 3. A substrate (11) and an electrode plate after a brazing step.
The method for producing a thermoelectric module according to claim 1 or 2, further comprising a step of surface grinding or cutting the surface of (18). 4. A substrate (11) and an electrode plate after a surface grinding step.
The method for manufacturing a thermoelectric module according to any one of claims 1 to 3, further comprising a step of applying an electrical insulating layer (36) to the surface of (18).