JPH10229223A - Thermoelectric element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the welding strength between thermoelectric elements and electric conductive parts for avoiding release etc. and the short circuit between the thermoelectric elements due to solder extrusion, by a method wherein non-planar parts for increasing the welding strength are provided on welded surfaces on specific positions of two each of substrates. SOLUTION: A thermoelectric element 10 made of P type or N type semiconductor is formed in a rectangular parallelopiped as a whole also forming the junction surfaces 11, 12 between this thermoelectric element 10 and electric conductive parts into flat surfaces. At this time, the parts of the flat surfaces, i.e., the outer periphery is taperingly chamferred so as to form non-planar parts 13. Thus, the surface area on the junction surfaces 11, 12 as the thermoelectric element 10 can be substantially widened, thereby enabling the junction strength to be increased so that, when the junction surfaces 11, 12 are respectively welded onto the electric conductive parts provided on the upper and the lower substrates by soldering process, the lateral extrusion of solder may be suppressed, thereby enabling the performance of a thermomodule to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric element used for a thermo module, and more particularly, to a thermoelectric element in which the area of a joint surface between a thermoelectric element and a substrate is increased to increase the strength of a weld. Things.

[0002]

2. Description of the Related Art As a generally known thermo module, for example, a thermo module having a configuration shown in FIG. 14 is well known. The thermo module 60 includes a large number of thermoelectric elements (Peltier elements) 63 between upper and lower substrates 61 and 62.
Are arranged in a sandwich with a predetermined arrangement, and upper and lower ends of the thermoelectric element 63 are integrally formed by welding each of them by welding means such as soldering.

The upper and lower substrates 61 and 6 used in this case are
As shown in FIGS. 15 (A) and (B), electrical conduction portions 64a and 64b are formed on the welded surface side of each of them. Electrical conduction portion 64 formed on upper substrate 61
a and the electrically conductive portion 64b formed on the lower substrate 62
The arrangement direction is slightly different from that of the first embodiment in that a large number of soldered thermoelectric elements 63 are arranged in series between the electrodes 65 and 66.

A large number of thermoelectric elements 63 used here
Is made of a P-type semiconductor or an N-type semiconductor.
As shown in FIG. 6, each is formed in a rectangular parallelepiped shape. Then, the planar upper surface 67 and lower surface 68 of the thermoelectric element 63 thus formed serve as bonding surfaces, which are soldered to the electric conducting portions 64a and 64b provided on the upper and lower substrates 61 and 62, as described above. Are all connected in series.

In connecting a large number of thermoelectric elements 63, as shown in FIG. 17, P-type semiconductors and N-type semiconductors are alternately arranged, and an upper substrate 61 and a lower substrate 62 are arranged.
, P-type and N-type thermoelectric elements 63 are alternately connected in series via electric conduction portions 64a and 64b provided respectively.

When a predetermined voltage is applied between the electrodes 65 and 66 in this state, the P-type semiconductor and the N-type
Heat is generated or absorbed by the current flowing between the mold semiconductor and one substrate absorbs heat and the other substrate dissipates heat. Also, by reversing the polarity of the applied voltage, the substrate that absorbs heat and the substrate that dissipates heat are reversed.

[0007]

As described above, when a difference in thermal expansion occurs between the substrate on the heat-absorbing side and the substrate on the heat-dissipating side in the thermomodule constituted by the thermoelectric elements,
This difference causes thermal distortion, which causes a problem that peeling or the like occurs at the welded portion. When peeling or the like occurs at the welded portion in this way, there is a disadvantage that the heat absorption and heat dissipation operations of the substrate due to the Peltier effect are hindered.

Further, not only the case due to thermal strain,
Even when the thermo module is provided in a place where vibration is likely to occur, there is a problem that the vibration causes peeling or the like at a welded portion.

If the solder is thickened in order to avoid the above-mentioned peeling, the solder 39 will protrude largely to the side of the joint surface as shown in FIG. Although it can be prevented, the protruding solder 69 causes a short circuit between the adjacent thermoelectric elements or between the electrically conductive parts, and there is a problem that a thermoelectric element which does not work is generated and heat absorption and heat radiation are not performed normally.

Therefore, in the conventional example, the welding strength between the thermoelectric element and the electrically conductive portion is increased without causing a short circuit between the thermoelectric elements or between the electrically conductive portions due to the protrusion of the solder, so that peeling or the like does not occur. There is a particular problem.

[0011]

As a specific means for solving the above-mentioned problems, the present invention is characterized in that both ends are welded to predetermined positions of two substrates capable of absorbing and dissipating heat, so that the two substrates are interposed between the two substrates. A thermoelectric element to be sandwiched, wherein the welding surface to be welded is to provide a thermoelectric element characterized by having a non-planar part for increasing welding strength, preferably a non-planar part Is a tapered surface formed by chamfering the outer periphery of the welding surface, and the non-planar portion is a groove formed at an arbitrary position on the welding surface.

As described above, by providing the thermoelectric element with the non-planar portion for increasing the welding strength, the bonding area with the substrate is increased, so that the welding strength at the welding portion is increased, and peeling or the like is less likely to occur. Withstand heat distortion and vibration,
Since the protrusion of solder or the like to the side can be reduced, it is possible to prevent short-circuiting between adjacent thermoelectric elements and between electrically conductive portions.

The non-planar part is a tapered surface formed by chamfering the outer periphery of the welding surface, and the non-planar part is a groove formed at an arbitrary position on the welding surface.
As the bonding area increases, the permeability of solder or the like becomes better, the number of voids (cavities) generated between the bonding surface of the thermoelectric element and the electrically conductive portion of the substrate decreases, and the adhesion becomes better.

[0014]

Next, some embodiments of the present invention will be described in detail with reference to the drawings. First,
A first embodiment shown in FIGS.

Thermoelectric element 1 made of P-type or N-type semiconductor
0 denotes a rectangular parallelepiped as a whole, and the upper and lower joining surfaces 11, 12
Is formed on a flat surface, and a part of the flat surface, that is,
The non-planar part 13 is formed by chamfering the outer peripheral surface in a tapered shape.

The formation of the non-planar portion 13 substantially increases the surface area of the bonding surface as the thermoelectric element 10, thereby increasing the bonding strength.

As shown in FIG. 4A, a thermoelectric element 10 made of a P-type semiconductor or an N-type semiconductor has a thickness of, for example,
It is formed by cutting a thermoelectric material 20 having a size of 5 mm and a width of 30 mm in a horizontal direction to a length of 2 to 5 mm square.

The thermoelectric material 20 is fixed on a plate 21 via a wax 22 by a method called wax down, and cut by an appropriate means. In addition, a reference line 23 indicating a cutting position is formed on the side surface.

At the time of cutting, first, the tip shown in FIG.
A V-groove is formed in advance at the position where the reference line 23 is formed on the surface of the thermoelectric material 20 by the V-shaped V-groove blade 24. This V-groove is used for all reference lines 2
It is formed at the position of No. 3.

On the surface, V is
After the grooves are formed, the wax is melted to release the fixed state between the thermoelectric material 20 and the plate 21, and the thermoelectric element 20
Is turned over and the thermoelectric element 20 is fixed again by wax-down.

Then, V-grooves are similarly formed on the back surface of the thermoelectric material 20 at all reference line 23 positions by V-groove blades 24.

After the V-grooves are formed on the front and back surfaces of the thermoelectric material 20 in this way, as shown in FIG. 4C, the cutting blade 25 is positioned at the most depressed portion of the V-groove. By performing cutting along all the reference lines 23, individual thermoelectric elements 10 are formed.

The thermoelectric material 20 obtained by cutting the end of the thermoelectric material 20 does not have a tapered surface at the outer periphery and may not be uniform in size. May be discarded.

The bonding surfaces 11 and 12 of the thermoelectric element 10 thus formed are connected to the upper and lower substrates 30 and 31 by soldering.
5 is welded to the electrically conductive portions 32a and 32b, respectively, as shown in FIG. 5, as compared with the conventional case where a thermoelectric element having no non-planar portion is welded to the joining surface. The protrusion 33 is reduced. Therefore, occurrence of a short circuit between adjacent thermoelectric elements and between electrically conductive portions can be prevented.

Further, since the non-planar portion 13 is provided, the surface area, that is, the joining area, is increased as compared with the case where the non-planar portion 13 is not provided. .

Next, a second embodiment shown in FIGS. The thermoelectric element 40 made of a P-type or N-type semiconductor has a rectangular parallelepiped shape as a whole,
The thermoelectric element 10 is similar to the thermoelectric element 10 shown in FIGS. 1 to 3 in that a flat surface 42 is formed and a part of the flat surface, that is, a tapered surface 43 is formed by chamfering the outer peripheral surface.

In the thermoelectric element 40 of the second embodiment, a cross groove 44 which is a V-shaped cross groove is further provided at the center of the joint surfaces 41 and 42, and is formed by the cross groove 44 and the tapered surface 43. A non-planar part is formed.

When the thermoelectric element 40 is formed, a flat, substantially rectangular parallelepiped thermoelectric material is fixed on a plate via wax similarly to the thermoelectric element 10 shown in the first embodiment. First, a V-groove cut is made using a V-groove blade along the reference line provided in.

Further, the already formed V groove and V
Another V-groove is inserted in the middle of the groove using another V-groove blade. The above process is performed on the front and back surfaces of the thermoelectric material. After all the V-grooves are formed on the front and back surfaces, first, the tip of the V-groove cut along the reference line is vertically and horizontally cut by a cutting blade. The individual thermoelectric elements 40 are formed by cutting.

The bonding surfaces 41, 42 of the thermoelectric element 40 formed in this manner are connected to the upper and lower substrates 30, 3 by soldering.
When welding to the electric conduction portions 32a and 32b provided in the first, solder flows into the cross groove 44 as shown in FIG. 9, so that the joining area is widened and the welding strength is increased. Further, the amount of the solder flowing into the non-planar portion formed by the cross groove 44 and the tapered surface 43 reduces the protrusion 45 to the side of the solder, so that the occurrence of a short circuit between adjacent thermoelectric elements and between the electrically conductive portions is higher. Can be prevented with probability.

The non-planar portion is not necessarily a tapered surface 4
It is not necessary to be constituted by the 3 and the cross groove 44, and only the cross groove 44 may be used. Further, the groove need not be a V-shaped groove, and may not be formed in a cross shape.

Next, a third embodiment shown in FIGS. The thermoelectric element 50 made of a P-type or N-type semiconductor has a rectangular parallelepiped shape as a whole,
1 and 52 are formed on a flat surface as shown in FIGS.
This is the same as the thermoelectric elements 10 and 40 indicated by.

In the thermoelectric element 50, the outer periphery is not a tapered surface, and three grooves 53 are provided vertically and horizontally to form a non-planar portion. The groove 53 constituting the non-planar part is
Instead of the groove, the cross section is a square groove.

When the thermoelectric element 50 having such a shape is formed, the thermoelectric element 10 shown in the first and second embodiments can be used.
As in the case of 40, a flat, substantially rectangular parallelepiped thermoelectric material is fixed on the plate via wax.

Next, grooves 53 having a square cross section are formed at regular intervals using a cutting blade. Then, after all the grooves 53 are formed, cutting is performed along a reference line using a cutting blade. When cutting is completed along all reference lines. Each thermoelectric element 50 has the shape shown in FIGS.

The bonding surfaces 51, 52 of the thermoelectric element 50 thus formed are connected to the upper and lower substrates 30, 3 by soldering.
When soldering to the electric conducting portions 32a and 32b provided in 1 respectively, as shown in FIG. 13, the solder flows into the groove 53, so that the joining area is increased by that amount and the welding strength is increased. Further, since the amount of the solder flowing into the groove 53 reduces the protrusion 54 to the side of the solder, it is possible to prevent the occurrence of a short circuit between adjacent thermoelectric elements and between the electrically conductive portions with a higher probability.

It should be noted that the non-planar portion does not necessarily need to be constituted by the grooves 53 provided vertically and horizontally, and may be only vertical or horizontal, or may be any number. Further, the groove need not be a V-shaped groove, and may be formed diagonally.

[0038]

As described above, according to the present invention, the thermoelectric element is provided with the non-planar portion for increasing the welding strength, so that the thermoelectric element can be joined to the electric conduction portions provided on the upper and lower substrates constituting the thermomodule. Since the area is increased, the welding strength at the welded portion is increased, peeling or the like is less likely to occur, heat resistance and vibration can be endured, and lateral protrusion of solder or the like can be reduced. Therefore, it is possible to prevent short-circuiting between adjacent thermoelectric elements and between electrically conductive portions, and to improve the performance of heat absorption and heat radiation of the thermomodule.

The non-planar portion is a tapered surface formed by chamfering the outer periphery of the welding surface, and the non-planar portion is a groove formed at an arbitrary position on the welding surface.
As the bonding area is increased, the permeability of solder and the like is improved, the voids (cavities) generated between the bonding surface of the thermoelectric element and the electrically conductive portion of the substrate are reduced, and the adhesion is improved.
Further, the performance of the thermo module can be improved.

[0040]

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a thermoelectric element according to the present invention.

FIG. 2 is a plan view showing the first embodiment of the thermoelectric element.

FIG. 3 is a side view showing the first embodiment of the thermoelectric element.

FIG. 4 is an explanatory view showing a shape of the thermoelectric element before cutting.

FIG. 5 is an explanatory diagram showing a state of welding the thermoelectric element to an electric conduction portion in the first embodiment.

FIG. 6 is a perspective view showing a second embodiment of the thermoelectric element.

FIG. 7 is a plan view showing a second embodiment of the thermoelectric element.

FIG. 8 is a side view showing a second embodiment of the thermoelectric element.

FIG. 9 is an explanatory view showing a welding state of the thermoelectric element with an electric conduction part in a second embodiment.

FIG. 10 is a perspective view showing a third embodiment of the thermoelectric element.

FIG. 11 is a plan view showing a third embodiment of the thermoelectric element.

FIG. 12 is a side view showing a third embodiment of the thermoelectric element.

FIG. 13 is an explanatory diagram showing a state in which the thermoelectric element is welded to an electric conduction portion in a third embodiment.

FIG. 14 is an explanatory view showing a conventional thermo module.

FIG. 15 is an explanatory view showing a substrate constituting a conventional thermo module.

FIG. 16 is a perspective view showing a shape of a thermoelectric element constituting a conventional thermo module.

FIG. 17 is an explanatory diagram showing a connection state of a conventional thermo module.

FIG. 18 is an explanatory diagram showing a connection state between a thermoelectric element and an electric conduction portion of a conventional thermo module.

[Explanation of symbols]

10: thermoelectric element 11, 12: bonding surface 13: non-planar part 20: thermoelectric material 21: plate 22: wax 2
3: Reference line 24: V-groove blade 25: Cutting blade 30, 31: Substrate 32a, 32b: Electrical conduction part 3
3: Extrusion 40: Thermoelectric element 41, 42: Joint surface 43: Tapered surface 44: Cross groove 45: Extrusion 50: Thermoelectric element 51, 52: Joint surface 53: Groove 5
4: Protruding

Claims (3)

[Claims] 1. A thermoelectric element having both ends welded to predetermined positions of two substrates capable of absorbing and dissipating heat and sandwiched between the two substrates, wherein a welding surface to be welded has a welding strength. A thermoelectric element provided with a non-planar part for increasing the size of the thermoelectric element. 2. The thermoelectric element according to claim 1, wherein the non-planar portion is a tapered surface formed by chamfering an outer periphery of the welding surface. 3. The thermoelectric element according to claim 1, wherein the non-planar part is a groove formed at an arbitrary position on the welding surface.