JPH02235569A - Soldering method for electronic parts - Google Patents

Abstract

PURPOSE:To eliminate an oxide film on the surface of solder and to improve an external appearance of a soldered part and its joining strength by dropping down a flux onto the surface of a jet part of molten solder at the time when electronic parts pass through a solder tank. CONSTITUTION:Tip parts of many lead wires 2 fixed to a mount 1 are allowed to pass through the inside of molten solder jetted from a solder tank 3. In this case, when a flux 5 is dropped down onto the surface of a jet part of molten solder 4, an oxide film formed on the surface can be eliminated, therefore, it can be prevented that the oxide film adheres to a lead wire 2, and the equalization of fluidity of the molten solder 4 can be quickened. The flux 5 is stirred enough in a stirring tank 6 in advance, and fed by a roller pump 8. The equipment is simple, solder can be allowed to adhere uniformly, and the external appearance and the joining strength can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a soldering method for soldering electronic components to lead wires or for applying solder only to the lead wires.

[Background Art] Soldering technology in the electronics industry plays a central role as a technology for joining and assembling electronic circuits and electronic materials.

There are various methods for soldering such electronic components, and among them, the jet method of immersion soldering is widely used in the electronic component industry in general. In this immersion soldering method, soldering is carried out through a solder tank in which molten solder is jetted, but since the flow of molten solder is relatively small at the center of the jet, an oxide film is likely to form on the surface. . The generated oxide film easily adheres to electronic components or lead wires, which prevents the molten solder from uniformly adhering to the electronic components or lead wires, resulting in poor appearance of the soldered area, bonding deterioration, and damage to the electronic components. This causes problems such as poor characteristics. Therefore, if you think about it simply, it is desirable to prevent the formation of oxide films and prevent these problems from occurring, but it is a natural phenomenon that metals oxidize in the atmosphere and form oxide films on their surfaces. Therefore, it is difficult to prevent the formation of an oxide film itself.

[Problems to be Solved by the Invention] As described above, in the jet method of the conventional immersion soldering method, the oxide film that is generated on the surface of the jet part of molten solder makes it difficult to solder electronic components and lead wires. There were drawbacks that had a negative impact.

The present invention was proposed in order to solve the problems of the prior art, and its purpose is to prevent the adhesion of an oxide film generated on the surface of the jet portion of molten solder.
To provide a highly reliable method for soldering electronic components, which can uniformly apply molten solder and eliminate poor appearance, poor bonding, and poor characteristics.

[Means for Solving the Problems] The electronic component soldering method of the present invention is a jet method of immersion soldering, in which flux is applied to the surface of the jet portion of molten solder when the electronic component or lead wire passes through a solder bath. It is characterized by dripping.

Functions] The functions of the electronic component soldering method according to the present invention having the above configuration will be described below.

That is, in the method of the present invention, the oxide film formed on the surface of the jet part of the molten solder can be chemically dissolved or removed by the flux dropped onto the surface of the jet part, so that the electronic component can be removed. It is possible to prevent the adhesion of an oxide film to the solder and lead wires, and to promote uniformity of fluidity of the molten solder. Therefore, molten solder can be applied more uniformly, and defects in appearance, bonding deterioration, and characteristic defects can be eliminated.

[Example] Hereinafter, an example of the method for soldering electronic components according to the present invention will be specifically described with reference to the drawings.

The embodiment shown in the drawings has a large number of lead wires 2 fixed to a mount 1.
In this method, the tip of the solder is passed through the molten solder 4 jetting from the solder bath 3, and flux 5 is dripped during the passage.

In this case, the flags 5 are stirred by stirring blades 7 in a stirring tank 6, and the well-stirred flux 5 is sent out through a tube 9 by a roller pump 8 and dripped onto the surface of the jet part of the molten solder 4. .

The operation of this embodiment having such a configuration is as follows.

That is, by dropping the flux 5 onto the surface of the jet part of the molten solder 4, the oxide film formed on the surface of the jet part can be removed, so that adhesion of the oxide film to the lead wire 2 can be prevented. It can promote uniformity of fluidity. Therefore, compared to the conventional technique in which an oxide film is attached, molten solder can be uniformly attached, the appearance and bonding strength can be improved, and the characteristics of the electronic component can be improved accordingly.

In addition, this embodiment has a simple configuration that only uses a stirring tank 6 and a roller bomb 8, and only drops Flags 5, and has good workability, so it is suitable for practical use. There is.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be similarly applied to cases where lead wires and electronic components are soldered, and similar effects can be obtained. Further, the means for dropping the flux 5 is not limited to the roller bomb 8.
For example, a configuration using a dispenser cylinder or the like may be considered.

[Effects of the Invention] As explained above, in the present invention, with the extremely simple configuration of dropping flux during solder immersion,
Because it can remove the oxide film formed on the surface of molten solder,
It is possible to provide a method for soldering electronic components with excellent reliability, which can improve the appearance and bonding strength of soldered parts compared to conventional methods, and can contribute to improving the characteristics of electronic components.

[Brief explanation of drawings]

The drawing is a perspective view showing a soldering method according to an embodiment of the present invention. 1... Mounting paper, 2... Lead wire, 3... Solder tank, 4
... Molten solder, 5... Flux, 6... Stirring tank, 7... Stirring blade, 8... Roller pump, 9...
tube.

Claims (1)

[Scope of Claims] A method for soldering electronic components in which an electronic component and a lead wire are soldered through a solder bath in which a jet of molten solder is applied, or solder is applied only to the lead wire, comprising: When the wire passes through the solder bath,
A method of soldering electronic components characterized by dropping flux onto the surface of a jet portion of molten solder.