JPH0215974B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a contact bonding device,
In particular, the present invention relates to a contact joining device for spot welding a contact to one end of a pedestal.

[Prior Art] FIG. 1 is a block diagram showing a conventional contact bonding device. In FIG. 1, a contact 2 is spot-welded to the surface of one end 101 of a pedestal 1. As shown in FIG.
The first electrode 3 is in contact with the contact 2. The second electrode 4 is opposed to the first electrode 3 and is in contact with the back surface of the pedestal 1 . A welding power source 5 is connected between the first and second electrodes 3 and 4.

Next, the operation of the conventional device will be explained. The contact 2 and one end 101 of the pedestal 1 are sandwiched between the first and second electrodes 3 and 4, and after applying pressure, electricity is applied by the welding power source 5, and the contact 2 and the one end 101 are joined by Joule heat generation. Was.

[Problems to be Solved by the Invention] By using such a so-called direct current type spot welding machine, the contact 2 is connected to the one end 10 of the pedestal 1.
1, bonding failures were likely to occur due to uneven temperature rise at the bonding interface. This situation will be explained based on FIG.

FIG. 2 is a conceptual diagram showing a bonding state by a conventional contact bonding device. In FIG. 2, bonding layer 6 is a layer where one end 101 of pedestal 1 and contact point 2 are bonded. The eluted metal 7 is metal eluted from the bonding layer 6. The bonding defect portion 8 is a portion where the bonding layer 6 is not formed between the one end portion 101 of the pedestal 1 and the contact point 2.

That is, as shown in FIG.
A bonding layer 6 is formed on the end side of 1, and the eluted metal 7 drips down significantly. On the other hand, on the side opposite to the end of the one end 101 of the pedestal 1, there is a strong tendency for bonding defects 8 such as notches to occur. Next, the cause of the occurrence of such a joint defect portion 8 will be explained based on FIG. 3.

FIG. 3 is an explanatory diagram of causes of defects in the conventional contact bonding device. As shown in FIG. 3, thermal saturation occurs at the end face of the base 1 at one end 101 of the base 1, but conversely, at the other end, which is the opposite side, there is a flow of water in the longitudinal direction. Path C is formed. Therefore, the temperature from point A to point B at the bonding interface has a steep downward slope as T _A −T _B , and as a result of bonding, the eluted metal 7 As well as dripping,
A bonding defect 8 such as a notch occurs on the opposite side of the one end 101 .

FIG. 4 is an actually measured temperature characteristic curve diagram of a conventional contact bonding device. In FIG. 4, time t is plotted on the horizontal axis and temperature T is plotted on the vertical axis. Characteristic curve A is the characteristic curve at point A of the bonding interface shown in FIG.
The characteristic curve and current waveform It of the joint interface point B shown in the figure are the waveform diagrams of the welding current It, and the welding current I _t =
14500A, welding time 15 cycles, pressing force 110Kg, pedestal 1 thickness 5mm, width 3.5mm, length 40mm, and distance between joint interface points A and B 7mm.

As is clear from Figure 4, the temperature on the side of point A of the bonding interface is 830℃, and the temperature on the side of point B of the bonding interface is 730℃.
℃, the temperature on the side of point A is high and the temperature on the side of point B is low. As a result, one end 10 of the pedestal 1
The eluted metal 7 drips from the end face of the one end 101, and a bonding defect 8 such as a notch is likely to occur at the other end of the one end 101.

The present invention has been made to eliminate the drawbacks of the conventional devices as described above, and an object of the present invention is to provide a contact bonding device that achieves stable bonding without bonding defects such as notches.

[Means for Solving the Problems] A contact joining device according to the present invention includes: a pedestal; a first electrode and a second electrode that sandwich a contact to be joined to the pedestal; a first electrode and a second electrode; a first power source electrically connected between the third electrode and the first electrode or the second electrode; It is equipped with the following.

[Function] The contact joining device according to the present invention applies a welding current from the first power source to the contact and the pedestal held between the first electrode and the second electrode. Further, a heating current is applied from the second power source so as to flow through the pedestal and the contact between the third electrode and the first electrode or the second electrode.

[Example] An example of the present invention will be described below based on the drawings.

FIG. 5 is a configuration diagram showing an embodiment of a contact joining device according to the present invention. In the figure, the same parts as in FIG. 1 are given the same reference numerals. In FIG. 5, the heating auxiliary electrode 9 is in contact with the surface of the other end side 102 of the pedestal 1. The heating power source 10 is connected to the heating auxiliary electrode 9 and the first electrode 3 . Cooling device 1
1 is made of a water-cooled material with good thermal conductivity, such as copper, and is brought into contact with the back surface of the base 1 facing the auxiliary heating electrode 9 . This cooling device 11 is provided when it is necessary to cool the pedestal 1, as will be described later, and has the function of cooling the pedestal 1.

Next, the operation of the apparatus of this invention will be explained using FIG. 6. Now, when the first and second electrodes 3 and 4 are pressurized and energized by the welding power source 5, the welding current I _t is as shown by the solid arrow in FIG.
→ first electrode 3 → contact 2 → pedestal 1 → second electrode 4
→Flows through the closed circuit of the welding power source 5, and joins the contact point 2 and one end portion 101 of the pedestal 1 by Joule heat generation. At this time, the heating current I _s is generated by the heating power source 10 as shown by the dotted arrow in FIG. →Flows through the closed circuit of the heating power source 10,
The other end side 102 of the pedestal 1 is actively heated. In this case, the magnitude of the heating current I _s , the timing at which it is applied (that is, the energization timing, such as whether it is energized during the energization period of the welding current I _t or the energization is stopped when the welding current I _t starts energization), and the energization timing. time, the thickness of pedestal 1,
Contact 2 and pedestal 1 can be set according to the width.
The temperature difference between the bonding interface points A and B of the one end portion 101 is extremely small as T _A - T _B.

FIG. 7 is an actually measured temperature characteristic curve diagram of the contact bonding device of the present invention. In Fig. 7, the horizontal axis is time t.
The temperature T is plotted on the vertical axis, and the characteristic curve A is the sixth
The characteristic curve of the joint interface point A _shown in _the figure, the characteristic curve B of the joint interface _point B _of FIG. The figure shows heating current I _s 6500A, heating time 17 cycles, welding current I _t = 13700A, welding time 13 cycles, pressing force 110Kg, pedestal 1 thickness 5mm, width 3.5mm,
The length is 40 mm, and the distance between the bonding interface points A and B is 7 mm.

As is clear from FIG. 7, the temperatures at the end of the _welding current It are almost the same at points A and B at the joint interface. As a result, one end 1 of the pedestal 1
A stable bond with a good bonding layer 6 can be obtained without dripping of the eluted metal 7 on the end face of 01 or with defective bonding portion 8 on the other end side of one end portion 101.

With the device configured as described above, it is possible to sufficiently reduce the temperature difference between the bonding interface points A and B. At this time, depending on the shape, mounting position, etc. of the heating auxiliary electrode 9, the side of the pedestal 1 where there is no contact, that is, the side 102, may be unnecessarily heated by the heating current _Is and may be softened and deformed. It is possible to do so. The shape of the heating auxiliary electrode 9,
If the problem cannot be improved by changing the mounting position, install the cooling device 11 described above and fix the other end side 102 of the pedestal 1.
It is best to cool it down. This cooling effect prevents the pedestal 1 from softening due to the heating current _Is .

Although the above embodiment shows the case where the heating power source 10 is connected between the auxiliary heating electrode 9 and the first electrode 3, it may also be connected between the auxiliary heating electrode 9 and the second electrode 4. . Further, as the cooling device 11, a spraying device that sprays a liquid or gas such as water or air onto the pedestal 1 from a nozzle may be used. in this case,
It can be sprayed from all around the pedestal 1, and the pedestal 1
softening can be further reduced.

[Effects of the Invention] As described above, according to the present invention, when the contact and the pedestal are bonded, the uneven temperature rise at the bonding interface between the contact and the pedestal can be extremely reduced, and therefore bonding defects such as notches do not occur. , which has the effect of significantly improving bonding stability.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing a conventional contact bonding device, Fig. 2 is a conceptual diagram showing a bonding state by a conventional contact bonding device, Fig. 3 is an explanatory diagram of causes of defects in the conventional contact bonding device, and Fig. 4 5 is a diagram showing an actual measured temperature characteristic curve of the conventional device, FIG. 5 is a configuration diagram showing an embodiment of the contact bonding device according to the present invention, FIG. 6 is an explanatory diagram of the operation of the contact bonding device of the present invention, and FIG. FIG. 3 is an actually measured temperature characteristic curve diagram of the contact bonding device according to the invention. In the figures, the same parts in each figure are denoted by the same reference numerals, 1... pedestal, 101... one end, 102
...Other end side, 2...Contact, 3, 4...1st, 2nd
5... power source for welding, 9... auxiliary electrode for heating, 10... power source for heating, 11... cooling device.

Claims (1)

[Claims] 1. A pedestal, a first electrode and a second electrode that sandwich a contact connected to the pedestal, and a first power source electrically connected between the first electrode and the second electrode. A contact bonding device comprising: a third electrode that is in contact with a pedestal; a second power source that is electrically connected between the third electrode and the first electrode or the second electrode. 2. The contact bonding device according to claim 1, characterized in that a pedestal cooling device is provided near the pedestal with which the third electrode comes into contact.