JPS60163494A - Soldering method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method of soldering electronic components onto a printed wiring board using laser light.

[Prior art]

Conventionally, this type of soldering was carried out as a method as described in Japanese Patent Application Laid-open No. 57-9.
1592, No. 57-111089, for soldering formed on a printed wiring board l as shown in Fig. 1, solder yeast 3 is applied on the pattern 2, and the f part 4 is vacuum colleted (or soldered). 7, place the soldering on the turf 2, and in this state, solder the electrode part 5 of the chip component 4.
A method has been proposed in which a focused laser beam 6 is irradiated onto and in the vicinity thereof to heat and solder. Also,
JP-A-57-111089 discloses a method of preheating the chip component 4 by heating the vacuum collet 7 to 6100 DEG C. to 150 DEG C. with a heating wire or the like.

In these conventional methods, after the chip component is mounted, radar light is irradiated near the electrode of the chip component to heat it.
To speed up solder melting, the solder paste itself had to be irradiated with laser light, so it was necessary to apply the solder paste so that it protruded outward (from the bottom surface of the chip component). Also, when soldering, keep the pattern small and place it so that it does not protrude beyond the bottom surface of the chip component.
Since the solder paste is hidden behind the bottom surface of the chip component and the solder paste itself cannot be irradiated with laser light, it is necessary to irradiate and heat the electrode part of the chip component itself with laser light so that the heat can be transferred to the solder paste. However, there was a drawback that the soldering time was long. For this reason, even in the case of falling, it has been difficult to achieve both sufficiently high soldering density and high speed of soldering.

[Purpose of the invention]

An object of the present invention is to provide a method capable of eliminating the drawbacks of the above-mentioned prior art and increasing the density and speed of soldering electronic components onto a printed wiring board. Soldering is accomplished by irradiating solder that has been supplied in advance on a pattern with a laser beam to melt it, then placing preheated electronic components on top of the molten solder while irradiating the laser beam, and soldering.

[Embodiment]

Hereinafter, one embodiment of the present invention will be described in detail,
This is not intended to limit the embodiments of the invention.

2 to 5 are diagrams for explaining one embodiment of the present invention, in which 1 is a printed wiring board, 2 is a soldering pattern formed on the printed wiring board 1, and 3 is a soldering/lean pattern. solder paste printed or applied on top, 4 is a chip component,
5 is an electrode part of the chip component 4, 6 is a laser beam as a heating source, 7 is a vacuum collector for mounting the chip component 4,
(or chuck), 8 is molten solder.

In the above configuration, as shown in FIG.
The solder formed on the pattern 2 is printed or applied with one stroke 3 of solder. When the solder paste 3 is irradiated with a laser beam 6 and heated, the solder paste 3 is melted as shown in FIG. Further, while the laser beam 6 is being irradiated onto the molten solder 8, the preheated chip component 4 is mounted on the soldering pattern 2 through the vacuum collet 7, as shown in FIG. At this time, the method of preheating the chip component 4 is to heat the vacuum collet 7 with a heating wire.
One example is a method in which the chip component 4 is preheated to about 00 DEG C. to 150 DEG C. and preheated by heat conduction to the chip component 4.

After mounting the chip component 4, the laser beam 6 is irradiated until the molten solder 8 is applied to the electrode portion 5 of the chip component, and then the vacuum collet 7 is removed and the irradiation of the laser beam 6 is stopped, as shown in FIG. Next, the chip component 4 is soldered onto the circuit board 2.

Although solder paste was used for soldering in the above embodiment, soldering may be performed by supplying foam solder that has been pre-soldered onto the pattern.

In addition, although the explanation was given using a chip component as an example,
Flat package IC components with leads can also be soldered in a similar manner.

〔Effect of the invention〕

As explained above, according to the present invention, even if the solder paste does not protrude from the bottom surface of the chip component, the solder paste can be heated and melted by directly irradiating the laser beam, so that the soldering paste can be heated and melted. No J? It becomes possible to make the turns smaller and increase the density. Further, since the preheated components are mounted on the already melted solder and heated, the time required for soldering is shortened and the speed can be increased.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the process of a conventional soldering method, and FIGS. 2 to 5 are diagrams for explaining the steps of a soldering method according to an embodiment of the present invention. 1...Printed wiring board, 2...Soldering nosoturn, 3
...Solder paste, 4...Chip parts, 5...
Electrode portion, 6... Laser light, 7... Vacuum collet (chuck), 8... Molten solder. i11Figure 2Figure 4Figure 1f5Figure

Claims (1)

[Claims] In the method of soldering electronic components to printed wiring boards,
Soldering on the wiring board is performed by irradiating the solder supplied in advance on the pattern with laser beams to melt it, and placing the preheated electronic components on the molten solder while irradiating the laser beam, and soldering. The special feature is the soldering method.