JPH09216051A - Laser brazing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the simple and low cost laser brazing method to directly join both an object to be joined of laminated part, in which metal materials or metal sheets of large heat capacity are laminated in plural sheets, and a lead wire without interposing an intermediate part of terminal, etc. SOLUTION: A paste-like brazing filter metal 5 is coated to the tip part of a lead wire 3, a laminated cross sectional face of an object 10 to be joined is brought into contact with the tip part of lead wire 3, while the position apart in a prescribed distance in the direction toward the laminated face of laminated material from this contact part is irradiated with a laser beam 7, brazing is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser brazing method for joining a lead wire to a laminated cross section of a metal material having a large heat capacity or a laminated body in which a plurality of metal plates are laminated.

[0002]

2. Description of the Related Art Conventionally, when a lead wire is joined to a laminate having a large heat capacity of a metal material or a plurality of metal plates, the lead wire is wound around a terminal implanted in an object to be joined, and the winding is performed. The part is coated with a paste-like brazing material and heated by a gas burner or a laser beam for brazing.

As an example of the conventional method, for example, Japanese Patent Laid-Open No. 63-
There is a joining method according to the publication indicated by 261689.

In FIG. 6, reference numeral 2 designates a terminal which is planted in contact with the base 1, around which the lead wires at both ends of the winding and the lead wire 3 of the electronic component are wound. This lead wire 3
A cream solder 5 is applied to the winding portion 4 around the terminal 2. Then, at a position near the winding portion 4 of the terminal 2, a liquid or cream-like light absorbing material 6 such as a carbon-containing conductive resin having a high absorptivity for the wavelength of the laser light.
Is applied. The light absorbing material 6 is irradiated with the laser beam 7, the heat energy of the laser beam 7 is efficiently absorbed by the light absorbing material 6, and the heat energy is transmitted to the winding portion 4 via the terminal 2, and the cream solder 5 Is melted and soldered.

[0005]

However, the above-mentioned conventional method does not directly bond the lead wire to the bonding object such as a metal material having a large heat capacity or a laminate in which a plurality of metal plates are stacked. , Wrap the lead wire around the terminal planted in the object to be joined, apply the paste brazing material to the winding part, and apply the light absorbing material near the lead wire winding part of this terminal. An indirect joining method via terminals, in which the light absorbing material applied on the terminals is irradiated with laser light to heat the terminals, and the heat is transmitted to the brazing material applied to the winding portion of the leads to perform brazing. Is.

Since the terminals are interposed, a method of fixing the terminals to a joining object such as a metal material having a large heat capacity or a laminated body of a plurality of metal plates is required, and lead wires to the terminals are required. There are problems that the winding device and the winding work are required, the cost of the terminal is added, the cost of the auxiliary equipment and the cost of the parts, and the number of manufacturing processes is increased, and the work time is increased.

The present invention has been made in view of the above-mentioned problems, and a bonding object such as a metal material having a large heat capacity or a laminate obtained by stacking a plurality of metal plates is directly connected to a lead wire without using a terminal or the like. It is an object of the present invention to provide a simple and inexpensive laser brazing method for joining to an object.

[0008]

According to a first aspect of the present invention, there is provided a laser brazing method in which a tip of a lead wire to which a brazing material is attached is brought into contact with a laminated cross section of a metal plate laminate to form a tip of the lead wire on the metal laminate. The laser beam is radiated at a position apart from the contact portion between the metal laminate and the metal laminate in the direction along the laminate surface of the laminate, and the lead wire is brazed to the metal laminate. .

The laser brazing method according to the second invention is
In the laser brazing method of the first invention, a laser beam absorbent is applied in advance to a laser beam irradiation position on the metal laminate.

The laser brazing method according to the third invention is
The tip of the lead wire with the brazing material is brought into contact with the object to be joined, and the laser beam is directly irradiated to the contact portion between the tip of the lead wire on the object to be joined and the object to be joined to form a lead wire on the object to be joined. It is brazed.

A laser brazing method according to a fourth invention is
In the laser brazing method of the third invention, the object to be joined is a metal plate laminate and the joining surface is a laminate cross section of the metal plate laminate.

[0012]

Embodiments of the present invention will be described below. Embodiment 1. FIG. 1 is an explanatory view for explaining a laser brazing method according to the present invention, and a case where a lead wire is joined to a laminated cross section of a laminate obtained by laminating a plurality of metal plates will be described. In FIG. 1, 10 is an object to be joined,
It is a laminate made by stacking multiple metal plates. Further, a paste brazing material 5 is applied to the tip of the lead wire 3, and the tip is brought into contact with the laminated cross section. Next, by irradiating the laser beam 7 to a position 11 (hereinafter, referred to as a laser beam irradiation position) which is separated from the contact portion by a predetermined distance in the direction along the lamination surface of the laminated material, the laser beam irradiation position 11 is changed. To heat. Heat is transferred from the heated laser beam irradiation position 11 to the brazing material at the contact portion of the lead wire by heat conduction, and as a result, the pasty brazing material 5
After the melting starts, the object to be joined and the lead wire are joined.

Here, the reason for selecting the laser beam irradiation position 11 will be described with reference to FIG. The laser beam irradiation position 11 is not a position separated from the lead wire contact portion by a predetermined distance in the direction along the laminated surface of the laminated material,
When the laser beam 7 is irradiated at a position 11 apart from the laminating material in a direction perpendicular to the laminating surface as shown in (a), a heat insulating action occurs in the air layer in the gap between the metal plates laminated. . As a result, an isothermal curve as shown by 12 is drawn on the laminated cross section of the objects to be joined, and the heat conduction to the lead wire contact portion is markedly hindered. As a result, the brazing material 5 cannot be melted.

On the other hand, as shown in FIG. 2 (b), when the laser beam is applied to the position 11 apart from the lead wire contact portion by a predetermined distance in the direction along the laminated surface of the laminated material, it is shown in the figure. As shown by the isothermal curve 12, the heat conduction in the direction along the laminated surface of the laminated material is greatly promoted. In this case, since there is no air layer that hinders heat conduction between the heating portion and the joint portion by the laser beam, efficient heat conduction becomes possible. Therefore, as a result of being able to melt the pasty brazing material 5 quickly, it becomes possible to directly bond the object 10 and the lead wire 3.

Embodiment 2 Next, a second other embodiment of the present invention will be described with reference to the drawings. FIG. 3 is an explanatory diagram for explaining the brazing method according to the present invention. The reason for selecting the laser beam irradiation position 11 is the same as that in the first embodiment, and thus the description thereof will be omitted. In FIG. 3A, a laser beam absorber 13 is applied in advance to a laser beam irradiation position 11 which is apart from the lead wire contact portion in the direction along the laminated surface of the laminated material by a predetermined distance, and then the laser beam 7 is irradiated. To do. As a result, the laser beam absorbing material 13 causes the laser beam irradiation position 11
The heat absorption in is more effectively performed than in the first embodiment.
As a result, the heat conduction from the beam irradiation position to the joining point on the laminated cross-section of the object to be joined 10 is further greatly promoted, and the laminated material of the first embodiment as shown in FIG. Isothermal curve 12 long along the stacking plane
Will be drawn. Therefore, the pasty brazing material 5 can be melted more efficiently. as a result,
Similar to the first embodiment, it is possible to directly bond the bonding target 10 and the lead wire 3.

Embodiment 3 Next, a third embodiment of the present invention will be described. In FIG. 4, the lead wire 1 in which the solid preliminary brazing 14 is applied to the tip of the lead wire 3 in advance
5 was brought into contact with the object to be joined 10, and the laser beam 7 focused by the condensing optical system 16 was focused on this contact portion to perform welding. The focal point of the laser beam 7 is matched to the contact portion, and the irradiation beam diameter at the laser beam irradiation position 11 is focused on a very small area and has a high energy density. It becomes possible to melt sufficiently. Needless to say, the lead wire 3 covered with the solid preliminary brazing material 14 can be easily melted. Therefore, the solid spare brazing material 1
The lead wire 3 covered with 4 and the bonding target 10 can be melted at the same time.

FIG. 5 shows a welding state of the lead wire 15 to which the solid preliminary brazing is applied and the object to be joined 10 which are obtained as a result. As shown in the figure, as a result of welding by focusing the laser beam 7 focused by the focusing optical system 16 on the contact portion,
Inside the object 10 to be welded, a penetration shape portion 17 as a trace of melting of components composed of both the solid brazing material and the object to be joined, and a solid brazing material 14 on the surface of the object 10 to be joined.
The brazing filler metal expanded portion 18 is obtained as a trace of the melted and expanded material. As a result, the bonding target 10 and the lead wire 3 are
It is possible to join directly in an instant.

[0018]

In the laser brazing method according to the first aspect of the present invention, the tip of the lead wire to which the brazing material is attached is brought into contact with the lamination cross section of the metal plate laminate, and the tip of the lead wire on the metal laminate is laminated with the metal lamination. Since the laser beam is irradiated at a position apart from the contact part with the object in the direction along the lamination surface of the laminate by a predetermined distance, and the lead wire is brazed to the metal laminate, the laser beam irradiation position Efficient heat conduction to the lead wire contact part is possible, and the paste-like brazing material can be quickly melted. Further, it is possible to provide a simple and inexpensive laser brazing method in which a lead wire is directly joined to a laminate having a large heat capacity of a metal material or a plurality of metal plates without using a terminal or the like.

The laser brazing method according to the second invention is
In the laser brazing method of the first invention, since the laser beam absorbent is applied in advance to the laser beam irradiation position on the metal laminate, heat absorption in the object to be bonded at the laser beam irradiation position is activated, and the lamination is performed. Heat conduction in the direction along the laminated surface of the material is further greatly promoted. As a result, efficient heat conduction to the lead wire contact portion becomes possible.
Therefore, as a result of being able to melt the paste-like brazing material more quickly, the lead wire can be directly joined to a laminate having a large heat capacity of a metal material or a plurality of metal plates without interposing terminals, etc. Allows inexpensive laser brazing.

The laser brazing method according to the third invention is
The tip of the lead wire with the brazing material is brought into contact with the object to be joined, and the laser beam is directly irradiated to the contact portion between the tip of the lead wire on the object to be joined and the object to be joined to form a lead wire on the object to be joined. Since brazing is performed, a high focused energy density can be obtained at the laser beam irradiation position, and the lead wire covered with the solid preliminary brazing material and the bonding target are melted at the same time. As a result, it is possible to instantly and firmly bond the lead wire directly to a metal material having a large heat capacity without using a terminal or the like.

The laser brazing method according to the fourth invention is
The tip of the lead wire to which the brazing material is attached is brought into contact with the laminated cross section of the metal plate laminate, and the laser beam is directly irradiated to the contact portion between the tip of the lead wire on the object to be joined and the object to be joined. Since the lead wire is brazed, a high focused energy density can be obtained at the laser beam irradiation position, and the lead wire covered with the solid preliminary brazing material and the object to be bonded are simultaneously melted. As a result, it becomes possible to instantly and firmly join the lead wire directly to a laminate in which a plurality of metal plates are superposed, without using a terminal or the like.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a laser brazing method according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a reason for selecting a laser beam irradiation position in the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a laser brazing method according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a laser brazing method according to a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a welding state obtained in the third embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional laser brazing method.

[Explanation of symbols]

1 base, 2 terminals, 3 lead wires, 4 winding parts, 5
Cream solder or paste wax material, 6 light absorbing material, 7 laser beam, 10 joining object, 11 laser beam irradiation position, 12 isothermal curve, 13 laser beam absorbing material, 14 solid preliminary brazing material, 15 solid preliminary brazing material Lead wire, 16 condensing optical system, 17 fused shape, 18 brazing material expansion part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01R 43/02 H01R 43/02 A

Claims (4)

[Claims] 1. A brazing material-attached lead wire tip is brought into contact with a laminated cross section of a metal plate laminate, and the lead wire tip on the metal laminate is contacted with the metal laminate to form the laminate. A laser brazing method comprising irradiating a laser beam at a position separated by a predetermined distance in the direction along the laminate surface of the object to braze the lead wire to the metal laminate. 2. The laser brazing method according to claim 1, wherein a laser beam absorbent is applied in advance to a laser beam irradiation position on the metal laminate. 3. A tip of a lead wire to which a brazing material is attached is brought into contact with an object to be joined, and a laser beam is directly irradiated to a contact portion between the tip of the lead wire on the object to be joined and the object to be joined. A laser brazing method, characterized in that the lead wire is brazed to the joining object. 4. The laser brazing method according to claim 3, wherein the object to be joined is a metal plate laminate and the joining surface is a laminate cross section of the metal plate laminate.