JPH01132079A - Electrode for heat pressure welding - Google Patents

Abstract

PURPOSE:To prevent the deterioration of mechanical strength of the connection part by installing pressing plates made of a ceramics at the sides of electrodes which connect materials to be connected in a heat pressure welding. CONSTITUTION:Electrodes 10 and 11 which consist of tungsten(W), molibdenum(Mo), tantalum(Ta), and the like, are installed at the ends of electrode holders 20 and 21 which are made of a copper alloy opposing each other, and pressing plates 40 made of a ceramics are installed at the sides of the electrodes 10 and 11. The pressing plates 40 have the insulating property and the adiabatic property, and even though a current is applied between the electrodes 10 and 11 in the connection process, only the electrodes 10 and 11 are heated by the resistant heating to raise the temperature, while the pressing plates 40 are heated at the inner sides contacting the electrodes 10 and 11 to raise the temperature a little, and the outer sides contacting the outside air are at the temperature almost equal to that of the outside air. Consequently, the stress is not concentrated to the materials to be connected in the connection process, and the deterioration of mechanical strength is never generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a thermocompression welding electrode for joining materials to be joined by thermocompression welding.

(Prior art) Metals with high resistance and high melting point, such as tungsten (
Electrodes made of materials such as W), molybdenum (MO), and tantalum (Ta) are known.

With this electrode, the electrode itself generates resistance heat, so there is no problem even if the materials to be welded have excellent conductivity such as copper or copper alloys, which are considered unsuitable for resistance welding due to the resistance heat generation of the materials to be joined. It is possible to join.

<Problems to be Solved by the Invention> In order to join materials to be joined, such as conductors of electric wires, using the above electrode, as shown in FIG. Attach the electrodes 1100 and 110 to face each other, respectively, and
The joint part 31 of the electric wire 30 is set between the electrodes 100 and 110, and the joint part 31 is sandwiched between the electrodes 100 and 110 and pressurized (approximately 200 ha to 300 km).
o degree), current is applied between the electrodes 100 and 110, and the electrode 100
．． It is conceivable that the bonding portion 110 itself generates resistance heat and the bonding portion 31 is bonded using the generated heat.

During the above bonding, the portion on the corner 101.111 side of the fifth electrode 100.110 of the bonded portion (the portion surrounded by the dotted line in FIG. 3) has an electric current of exactly t! This is the boundary between the heat-affected part that is in contact with i100 and 110 and the non-heat-affected part that is off the electrodes 100 and 110. However, at this boundary,
While one heat-affected area is at a high temperature, the other non-heat-affected area is not so hot, resulting in a large temperature difference between the two, which tends to cause stress to concentrate at the boundary.
There was a problem that the mechanical strength of this part decreased after joining.

This invention was made in order to solve the above-mentioned problems of the prior art, and its purpose is to prevent stress from being concentrated on the materials to be joined during welding operations and to avoid the risk of reducing mechanical strength. An object of the present invention is to provide an electrode for thermocompression welding.

[Effects of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention includes a ceramic pressing plate attached to the side surface of the electrode that joins the materials to be joined by thermo-pressure welding. It is a feature.

(Function) The pressure plate is made of ceramic and has insulation and heat insulation properties. Even if electricity is applied between the electrodes during the bonding operation, only the electrodes will rise in temperature due to resistance heat generation, whereas the suppression plate The inner surface that is in contact with it is heated and its temperature slightly rises, and the outer surface that is in contact with the outside air has a temperature that is almost equal to that of the outside air. That is,
A temperature gradient occurs at the press plate, and stress concentration at the boundary between the heat-affected zone and the non-heat-affected zone can be alleviated.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

1 and 2 show an example of an electrode for thermocompression welding according to the present invention, and reference numerals 10 and 11 in the figures indicate electrodes made of, for example, tungsten (W), molybdenum (MO), tantalum (Ta), etc. , are attached to the ends of electrode holders 20 and 21 made of prepared alloy so as to face each other, but what makes this part unique to an automobile is that a ceramic pressing plate 40 is attached to the side thereof. .

In the rigid embodiment, a dovetail groove 40a is formed on the inner surface of the pressing plate 40 as shown in No. 2-, and the electrode #4i10.1
Dovetails 10a and 11a are formed on the outer surface of 1,
A pressing plate 40 is detachably attached to both left and right outer surfaces of the electrode 10.11 through engagement between the dovetail groove 40a and the dovetail 10a1i1a. Further, an end surface 40b of the press plate 40 that comes into contact with the material to be welded 30 is formed into a smooth arc shape.

When the ceramic press plates 40 are attached to both the left and right outer surfaces of the electrode 10.11 in this way, when joining the materials 30 such as electric wires, the heat-affected zone in contact with the electrode 10.11 and the electrode 1
It is possible to alleviate stress concentration at the boundary with the non-heat-affected zone which deviates from 0.11.

That is, the joining portion 31 of the material to be joined 30 is connected to the electrode 10.1.
While applying pressure while sandwiching the electrodes 10 and 11 between
When current is applied between the electrodes 10 and 11, only the electrodes 10 and 11 rise in temperature due to resistance heat generation, but since the press plate 40 is made of ceramic and has insulation and heat insulation properties, no resistance heat generation occurs and the electrodes 10 and 11
0.11 is heated by the electrode 10.11 and the temperature rises only slightly, and the temperature of the outer surface side that is in contact with the outside air is almost equal to the temperature of the outside air. In other words,
During the bonding operation, a temperature gradient occurs inside the press plate 40,
Temperature is moderated to prevent sudden changes in temperature between the heat-affected zone and the non-heat-affected zone. Therefore, the stress generated at the boundary between the two is alleviated.

On the other hand, regarding the electrodes 10 and 11, heat due to resistance heating is efficiently transmitted to the joining portion 31 by the press plate 40 without being radiated to the outside, and reliable joining can be achieved.

Therefore, there is no problem that the mechanical strength of the bonded portion 31 decreases after bonding, and the reliability of bonding can be improved, and the efficiency of bonding work can be improved.

In the above embodiment, the pressing plates 40 were attached to both the left and right outer surfaces of the electrodes 10.11. It may be attached only to one of the outer surfaces.

[Effects of the Invention] As explained above, according to the electrode for thermopressure welding of the present invention,
A ceramic pressure plate is attached to the side, so
Stress is not concentrated on the materials to be joined during the joining operation, and there is no risk of reducing mechanical strength. Furthermore, since the heat of the electrodes is not radiated to the outside, reliable bonding can be achieved.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 show an embodiment of this invention.
FIG. 1 is a side view, FIG. 2 is a plan view of the electrode portion, and FIG. 3 is a side view showing the prior art. 10.11...Electrode 40...Press plate agent Patent attorney Yasuo Miyoshi Figure 3 6 tl et 4ffQ-ITI-IN

Claims (1)

[Claims] A thermocompression welding electrode characterized by having a ceramic pressing plate attached to the side surface of the electrode that joins materials by thermocompression welding.