JP2571366B2 - How to attach electronic components - Google Patents

Description

The present invention relates to an electronic component mounting method for mounting a leadless chip-shaped electronic component on a printed circuit board or the like.

(Prior Art) Conventionally, when a leadless chip-shaped electronic component is mounted on a printed circuit board, an adhesive 8 for temporary fixing is previously applied to an intermediate position of the conductive pattern 5 on the printed circuit board 2 as shown in FIG. In addition, as shown in FIG. 8, the chip-shaped electronic component 4 is suction-transferred and attached to the adhesive application position by the suction head.

(Problems to be Solved by the Invention) By the way, according to the conventional leadless chip-type electronic component mounting method, the electrodes of the electronic component and the substrate-side conductive pattern are finally soldered in a soldering process. Before the assembly, the chip-shaped electronic components temporarily fixed to the substrate may fall off due to the impact during handling of the substrate due to variations in the adhesive strength of the adhesive, drying conditions, etc. Because of the coating step, there is a disadvantage that the number of steps for mounting the chip-shaped electronic component is large.

(Means for Solving the Problems) In view of the above points, the present invention provides an electronic component on a substrate-side conductive pattern by irradiating a laser beam or infrared rays simultaneously with transferring a chip-shaped electronic component onto a substrate by a suction head. It is an object of the present invention to provide a method of mounting an electronic component that does not require a conventional temporary fixing with an adhesive by directly connecting and fixing the electronic component.

The present invention provides either a solder or a tin layer to an end electrode of a chip-shaped electronic component and / or a solder layer to a conductive pattern on a substrate, and the chip-shaped electronic component is lifted and lowered by a suction head. A part is sucked and placed on the substrate, and in this mounted state, a laser beam or infrared light is emitted from an irradiation head provided on the suction head side so as to be able to move up and down independently or independently of the suction head, and to the end electrode. Any of the solder or tin layer and the solder layer of the conductive pattern,
Or, by applying to both, by melting the solder or tin layer on the end electrode side and the solder layer on the conductive pattern side, or both, and connecting and fixing the end electrode to the conductive pattern, This solves the problems of the prior art.

(Function) In the electronic component mounting method of the present invention, when the electronic component is transferred onto the substrate, a laser beam or infrared light is applied (irradiated) to one or both of the electrode of the electronic component and the conductive pattern of the substrate, Either or both of the electrode and the conductive pattern are melted to electrically connect the electrode to the conductive pattern and can be mechanically fixed, eliminating the need for a temporary adhesive and a subsequent soldering step. it can. Also, since the electronic components are securely fixed,
An operation such as inserting a separate electronic component in a separate step on a substrate on which the electronic component is mounted according to the present invention can be performed without any trouble.

(Example) Hereinafter, an example of a method of attaching an electronic component according to the present invention will be described with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS.
In these figures, reference numeral 1 denotes a suction head, which is moved to an arbitrary position on the printed circuit board 2 (or the substrate side is moved) by an XY table mechanism or the like, and is movable up and down by an air cylinder or the like. . A pair of irradiation heads 3 are arranged on the side of the tip portion of the suction head 1. These irradiation heads 3 irradiate a laser beam or an infrared ray to an end electrode 4A of a chip-shaped electronic component 4 as a leadless electronic component. (Or the substrate side moves), and can move up and down independently or independently of the suction head.

In the case of a general chip-type electronic component 4, the end electrode 4A is usually provided with a few layers of solder, tin plating, etc., by baking silver-palladium alloy, electroplating or the like. It is.

First, the suction head 1 sucks the chip-shaped electronic component 4 as a leadless electronic component from the supply unit by using a vacuum suction force and moves to a predetermined position on the substrate 2 as shown in FIG.

Next, as shown in FIG.
The chip-shaped electronic component 4 is placed thereon. At this time, the end electrodes 4A at both ends (short sides) of the electronic component 4 are located on the conductive pattern (wiring pattern of the metal layer) 5 on the substrate side. Then, in a mounted state in which the suction of the chip-shaped electronic component 4 by the suction head 1 is continued, a laser beam or an infrared ray is irradiated to the end electrode 4A from the irradiation head 3 located above both ends of the electronic component 4.

As a result, the end electrode 4A generates heat by receiving the energy of the laser beam or the infrared light, and the layer of the solder, tin, etc. of the end electrode 4A is melted, and the solidified portion of the electrode fused portion 6 is cooled (after irradiation is stopped). Thereby, the end electrode 4A of the chip-shaped electronic component 4 is electrically connected to the conductive pattern 5 and mechanically fixed.

The operation start timing of the irradiation head 3 can be easily set by detecting that the suction head 1 has brought the chip-shaped electronic component 4 into contact with the substrate with a sensor or the like.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, in the mounting state where the suction of the chip-shaped electronic component 4 by the suction head 1 is continued so that the end electrode 4A of the chip-shaped electronic component 4 is positioned on the conductive pattern 5 on the printed circuit board 2 side. A laser beam or infrared light is applied to the conductive pattern from the irradiation head 3 located on both sides of the electronic component 4.
Irradiation.

As a result, the conductive pattern 5 receives the energy of the laser beam or the infrared ray and locally generates heat, and the surface of the conductive pattern 5 and the layer of the solder or tin of the end electrode 4A in contact therewith are melted. By subsequent cooling and solidification of the melted portion 6A, the end electrodes 4A of the chip-shaped electronic component 4 are electrically connected to the conductive pattern 5 and mechanically fixed.

4 and 5, a third embodiment of the present invention will be described.
In the third embodiment, the conductive pattern 5 on the printed circuit board 2 has a structure having a solder layer 7 on the surface in advance. That is, the solder layer 7 is provided on the lower metal wiring pattern by screen printing of cream solder or the like.

Then, in a state where the chip-shaped electronic component 4 is sucked by the suction head 1 and placed on the printed circuit board 2 and the end electrode 4A is positioned on the conductive pattern 5 on the printed circuit board 2 side,
The conductive pattern 5 is irradiated with a laser beam or an infrared ray from the irradiation head 3 located on both sides of the electronic component 4.

As a result, the conductive pattern 5 locally receives heat by receiving the energy of the laser beam or the infrared rays, and the solder layer 7 on the surface of the conductive pattern 5 is melted. The end electrode 4A is electrically connected to the conductive pattern 5 and mechanically fixed.

In the case of the third embodiment, since the solder layer 7 which is easy to melt is provided on the conductive pattern 5, there is an advantage that the energy of the laser beam or the infrared ray is relatively small.

In the third embodiment, if a mountain-shaped solder layer 7A as shown in FIG. 6 is provided on the conductive pattern 5 on the printed circuit board 2, melting can be further facilitated by local heating.

(Effect of the Invention) As described above, according to the electronic component mounting method of the present invention, either the solder to the end electrode of the chip-shaped electronic component or the tin layer and the solder layer to the conductive pattern on the substrate are used. Or both are provided, and the chip-shaped electronic component is sucked by a suction head that can be moved up and down and placed on the substrate, and in this mounted state, the suction is performed by being able to move up and down independently or independently of the suction head. Laser light or infrared light from the irradiation head provided on the head side, either the solder or tin layer of the end electrode and the solder layer of the conductive pattern,
Alternatively, by applying to both, either the solder or tin layer on the end electrode side and the solder layer on the conductive pattern side, or both are melted to connect and fix the end electrode to the conductive pattern. This eliminates the need for the conventional temporary fixing with an adhesive and the subsequent soldering step, and reduces the number of steps for mounting electronic components. In addition, since the electronic component is securely fixed to the substrate at the same time as the transfer by the suction head, there is an advantage that insertion of another electronic component or the like can be performed without hindrance in a later process.

[Brief description of the drawings]

1 and 2 are front sectional views for explaining a first embodiment of a method of mounting an electronic component according to the present invention, FIG. 3 is a front sectional view showing a second embodiment, FIG. 4 and FIG. FIG. 6 is a front sectional view illustrating a third embodiment, FIG. 6 is a front cross section showing an example of the shape of a solder layer in the third embodiment, and FIGS. It is a front sectional view explaining. DESCRIPTION OF SYMBOLS 1 ... Adsorption head, 2 ... Printed circuit board, 3 ... Irradiation head, 4 ... Chip-shaped electronic component, 4A ... End electrode, 5 ...
... conductive pattern, 7,7A ... solder layer.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shoichi Iwatani 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TEDK Inc. (72) Inventor Minoru Sato 1-13-1 Nihonbashi, Chuo-ku, Tokyo TEDK Co., Ltd. (56) References JP-A-60-257587 (JP, A)

Claims (1)

(57) [Claims] 1. A chip-shaped electronic component, wherein either or both a solder or a tin layer to an end electrode and a solder layer to a conductive pattern on a substrate are provided, and the chip-shaped electronic component is lifted and lowered by a suction head. The electronic component is sucked and placed on the substrate, and in this mounted state, a laser beam or infrared light is emitted from an irradiation head provided on the suction head side so as to be able to move up and down independently or independently of the suction head. One of the solder or tin layer of the electrode and the solder layer of the conductive pattern,
Or, by applying to both, either the solder or tin layer on the end electrode side and the solder layer on the conductive pattern side, or both are melted to connect and fix the end electrode to the conductive pattern. Characteristic mounting method of electronic components.