JPS63215386A - Parallel electrode type welding equipment - Google Patents

Abstract

PURPOSE:To prevent the reduction in welding strength with stabilized radiation effect without damaging the body to be welded by providing a particular elastic body between the base upper face and the body to be welded and making the body to be welded bring closely into contact with the base. CONSTITUTION:The elastic body 12 formed within the elastic limit of the body to be welded and with the thickness smaller than the max. deflection dimension by the bending action thereof is provided between the bodies to be welded of a solar battery element 13, etc., on the upper face of a base 11 in a parallel electrode type welding equipment. The back face electrode 15 of a solar battery 13 is abutted to the upper face of the elastic body 12 and placed on the base 11 via the elastic body 12. The connection electrode 16 as a welding body is arranged at the welding position of the surface electrode 14 of the solar battery 13. When welding electrodes 17, 17 are pressfitted to the connection electrode 16, the back face electrode 15 is buried in the elastic body 12 to make the back face of the solar battery 13 bring closely into contact with the elastic body 12. The connection electrode 16 and surface electrode 14 are welded by the resistance heat caused on itself by electrifying the welding electrodes 17, 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a welding device used for assembling semiconductor devices and devices.

[Conventional technology]

Conventionally, for example, when welding the surface electrode and connection electrode of a GaAs solar cell element (hereinafter referred to as a solar cell), it was necessary to stack the connection electrode on the surface electrode and use two welding electrodes close to each other for both electrodes. The welding area was welded by applying pressure from above and applying electricity to the welding electrode.

FIG. 3 is a perspective view showing a conventional welding state.

In the figure, reference numeral 1 is made of a highly rigid member such as aluminum or ceramic, and a welding device (not shown) is used.
A front surface electrode 2 and a back surface electrode 3 are mounted on the base 1, respectively.

A solar cell 4, which is an object to be welded, formed on the back surface is placed. Reference numeral 5 denotes a connection electrode which is a welding object, and 6 and 6 denote welding electrodes, which are each connected to a welding power source 7 and to a pressurizing device (not shown).

Therefore, the connecting electrode 5 is stacked on the surface electrode 2 of the solar cell 4 placed on the base 1, the welding electrode 6.6 is pressed from above with the required pressure, and while maintaining this state, the welding electrode 6, 6 The surface electrode 2 and the connection electrode 5 are welded by supplying current to the surface electrode 2 and the connection electrode 5.

[Problem that the invention seeks to solve]

In this way, with conventional welding equipment, the workpiece is placed on a base made of a highly rigid member, the workpiece is placed on top of the workpiece, and the welding electrode is pressed from above to weld the workpiece. Since the object to be welded is, for example, G
In the case of a semiconductor element such as a solar cell formed of aAs or St, a back electrode is partially formed on the back surface, a convex part is formed on the back electrode,
Alternatively, if the back surface of the object to be welded is formed with unevenness or some kind of protrusion exists on the back surface, the load of the welding electrode is concentrated on the protrusion and the object is likely to be damaged.

In addition, when this protrusion comes into contact with the base, a gap is created between the back electrode and the base, reducing the contact area between the workpiece and the base, making it difficult for welding heat to be conducted to the base, and welding There was a problem in that the electrical characteristics of the solar cell, which is the object to be welded, deteriorated due to excessive temperature rise in the part. Furthermore, the adhesion strength between the workpiece and the surface electrode decreases due to thermal stress caused by the difference in the coefficient of thermal expansion between the workpiece and the surface electrode, so there is a problem in that the welding strength decreases even when the connecting electrode is welded. .

[φ stage to solve problems]

The parallel electrode type welding device according to the present invention has an elastic welding device formed between the upper surface of the base and the workpiece, within the elastic limit of the workpiece, and having a thickness smaller than the Eidai deflection due to the bending action. It has a body.

[Effect]

The protrusion formed on the back side of the workpiece is buried in the elastic body,
The object to be welded is in close contact with the base via the elastic body.

〔Example〕

The present invention will be explained in detail with reference to embodiments shown in the figures. 1st
The figure is a perspective view showing the welded state of the solar cell in this example. In the figure, reference numerals 11, 13 to 18 are the same as those of the conventional example described above, and will be explained in more detail here. Reference numeral 11 denotes a base mounted on a welding device (not shown), and this base 11 is made of aluminum, ceramic, or the like because it requires rigidity.

Reference numeral 12 denotes an elastic body, and the elastic body 12 is made of silicone resin, and its thickness is within the elastic limit of the solar cell, which will be described later, and is smaller than the maximum bending dimension due to its bending action. It is installed on 11. That is, the elastic body 12 has a uniform thickness such that even if the solar cell is bent by being pressed against the welding electrode described later and the elastic body 12 is deformed, the amount of deflection is kept within the range of elastic deformation of the solar cell. It is formed with uniform elasticity. Reference numeral 13 denotes a solar cell as an object to be welded. The solar cell 13 is made of GaAs or St, and has a front electrode 14 and a back electrode 15 formed on its front and back surfaces, respectively. That is, this solar cell 1
3 is placed on the base 11 via the elastic body 12, with the back electrode 15 in contact with the upper surface of the elastic body 12. Reference numeral 16 denotes a connection electrode as a welding object, one end of which is placed at the welding position of the surface electrode 14. 17. 17 is a welding electrode, and this welding electrode 1717 is connected to a pressurizing device (not shown) and is movable up and down, and is also connected to a welding power source 18. Therefore, the welding electrode 17
．． 17 is pressed against the connecting electrode 16 for welding, the back electrode 15 of the solar cell 13 deforms the surface of the elastic body 12 against the elastic force and is buried in the elastic body 12, so that the back surface of the solar cell 13 is in close contact with the elastic body 12 over the entire surface. Further, when the welding electrodes 17 and 1γ are energized, the connection electrode 16 and the surface electrode 14 are welded by the resistance heat generated within the welding electrodes 17 and 1γ.

FIG. 2 is a side sectional view showing another embodiment. In the figure, members that are the same or equivalent to those in the embodiment described above are given the same reference numerals, and detailed explanations will be omitted.

The base 11 in this embodiment is used when welding the connection electrode 16 to the front electrode 14 of the solar cell 13, in which the back connection electrode 19 has been welded to the back electrode 15 in advance. A mounting surface for the workpiece to be welded is formed by protruding a portion of the surface electrode 14 corresponding to the welding portion, and the elastic body 12 is provided on the mounting surface. Reference numeral 20 denotes an elastic member for supporting the solar cell 13, which is made of a soft plastic foam and is adhered onto the base 11.

Therefore, the elastic body 12 is pressed by the protrusion formed on the back surface of the solar cell 13 when the welding electrodes 17, 1γ press against the solar cell 13, which is the object to be welded.

For this reason, the surface of the elastic body 12 deforms as if it were caved in,
Since the elastic body 12 absorbs the protrusion, the entire back surface of the solar cell 13 is in close contact with the elastic body 12. In addition, the welding heat is transmitted from the entire back surface of the solar cell 13 to the base 11 through the elastic body 12.
Heat is radiated to.

Note that the elastic body 12 is made of silicone resin, and the following are
It may be formed from a fluororesin having a high melting point.

Moreover, the parallel electrode type welding apparatus according to the present invention is not limited to welding electrodes of solar cells, and the same effect can be obtained even when used for other semiconductor devices.

〔Effect of the invention〕

As explained above, according to the present invention, even if a protrusion is formed on the back surface of the workpiece, the protrusion will not be damaged due to the simple structure of laying the elastic body on the base.

Further, since a stable heat dissipation effect can be obtained by closely adhering the welded object to the elastic body, the welded object will not be adversely affected by heat. Furthermore, even if the thickness of the elastic body is within the elastic limit of the object to be welded, the object to be welded may be bent and damaged by the load of the welding electrode because it is formed to be smaller than the maximum deflection due to its bending action. do not have.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a welded state of a solar cell according to the present invention, FIG. 2 is a side sectional view showing another embodiment, and FIG. 3 is a perspective view showing a conventional welded state. 11...Base, 12...Elastic body, 13...
Solar cell element, 16...φ, connection electrode, 17.17...
...Welding electrode.

Claims (5)

[Claims] (1) The workpiece to be welded and the workpiece to be welded are placed one on top of the other on a base, and a welding electrode with two electrodes arranged side by side is pressed against the welding workpiece from above, and current is applied between the two welding electrodes. In a welding device for welding an object to be welded to an object to be welded, there is a thickness between the upper surface of the base and the object to be welded, which is within the elastic limit of the object to be welded and smaller than the maximum deflection due to its bending action. A parallel electrode type welding device characterized in that it is provided with an elastic body formed with a cylindrical shape. (2) The parallel electrode type welding device according to claim 1, wherein the elastic body is made of silicone resin. (3) The parallel electrode type welding device according to claim 1, wherein the elastic body is a fluororesin. (4) The parallel electrode type welding device according to claim 1, wherein the base is made of metal. (5) The parallel electrode type welding device according to claim 1, wherein the base is made of ceramic.