Method and apparatus for laser soldering

Abstract

In accordance with an aspect of the invention, a solder paste feeding device feeds solder paste to a ring-like terminal surrounding a through-hole and a rod terminal fitted in the through-hole so as to fill in the through-hole, the laser beam irradiation device irradiates the solder past with a laser beam, and wire solder is further fed from above the solder past at the same time as melting of the solder paste is started, thereby fusing the wire solder and the solder paste to solder the ring-like terminal and the rod terminal.

Description

technical field [0001] The present invention relates to a technology for soldering electronic parts such as IC or LSI on a printed circuit board by laser. Background technique [0002] The technique of soldering electronic components such as IC or LSI to a printed circuit board by laser is a known technique, as disclosed in Patent Document 1 or Patent Document 2 below. These techniques are soldering techniques in which laser light is irradiated from a soldering head of a soldering device to a printed circuit board and solder is melted by the heat of the laser light, and have the advantage of enabling soldering without touching the solder. [0003] However, if Figure 7 As shown, insert the rod-shaped terminal 4a of the electronic component 4 into the through hole 3 surrounded by the ring-shaped terminal 2 on the printed circuit board 1 and use linear solder (welding wire) 5 to solder the rod-shaped terminal 4a and the In the case of the ring terminal 2, there is a problem t...

AI Technical Summary

Problems solved by technology

[0003] However, if Figure 7 As shown, insert the rod-shaped terminal 4a of the electronic component 4 into the through hole 3 surrounded by the ring-shaped terminal 2 on the printed circuit board 1 and use linear solder (welding wire) 5 to solder the rod-shaped terminal 4a and the In the case of the ring terminal 2, there is a problem that the laser beam 6 passes between the ring terminal 2 and the rod-shaped terminal 4a before the welding wire 5 is melted by the laser 6 and filled into the through hole 3. The gap 3a of the electronic component 4 is irradiated, so that the local part of the electronic component 4 is burned

If the laser is irradiated in this state, the solder paste located outside the ring terminal will remain in an unmelted state and scatter around the ring terminal. Therefore, it is easy to cause problems such as poor appearance and poor conductivity.

In addition, since a large amount of solder paste is supplied, not only does it take a certain amount of time to irradiate the solder paste to a molten state by laser light, but also the granular solder in the solder paste that has flowed into the through hole in advance does not melt completely, but Particle state remains, often causing poor welding

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