JPS59149090A - Method of mounting electronic part with lead wires - 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 The present invention relates to a method for mounting an electronic component with lead wires onto a substrate such as a printed wiring board.

Conventionally, when attaching electronic components with lead wires to a board,
As shown in the first figure, the lead wire 2 is generally inserted into the through hole 4 of the substrate 3, bent onto the connection electrode 5 formed on the back surface of the substrate 3, and soldered afterwards. In recent years, with the adoption of chip components, there has been a remarkable trend toward miniaturization of devices, and it is desired that devices equipped with electronic components with lead wires be made as small as possible. However, in the device mounted as described above, since there is a bent portion of the lead wire 2 on the back surface of the substrate 3, the height h of this portion becomes a so-called put space.

This height h depends on the lead wire diameter, amount of solder, etc.
．． Sometimes it was about 5 to 2.5 mm. Furthermore, according to this, the length ρ of the lead wire 2 of the electronic component 1 is equivalent to the thickness of the substrate 3, so when used for high frequency applications, there is a problem that the inductance due to the length ρ cannot be ignored. Ta.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a method for mounting an electronic component with lead wires, the main purpose of which is to prevent the lead wires inserted into the board from protruding from the board. It is something to do. The details of the present invention will be described below with reference to the drawings and examples.

Fig. 2 shows an example of the shape of an electronic component with lead wires used in the present invention, in which two leads of 1 g Al2. FIG. In the figure 1
3.13 is a solder protrusion that is attached in advance to the base of the lead wire 12.12 or its vicinity, and this protrusion 13.13 is used as a locking part on the board as described below. .

Next, as shown in FIG. 3, the electronic component 11 prepared in this way is inserted into the through hole 16.16 of the printed wiring board 14, which has the connecting electrode 15.15 formed on the negative side.
2.12 is inserted and held from the surface side where the connection electrode 15.15 is formed. In this case 7 lead wire 12.12 protrusion 13.13 is through hole 16.16
This means that the electronic component 11 is locked without getting into the hole.

Next, the electronic component and the board in this state are placed in, for example, a hot air atmosphere and heated. Then, the solder forming the protrusion 13.13 of the lead wire 12.12 melts, and the lead wire 1
2.12 and the connecting electrode 15.15 are conductively connected, and the electronic component 11 is fixed onto the substrate 14 by solidifying the solder (FIG. 4). In this case, the board 14 of the electronic component 11
In order to reduce the height of the top as much as possible, it is preferable to apply a load (arrow A) that presses the electronic component 11 toward the surface of the substrate 14 when the solder is melted.

Finally, a lead wire 12.1 protruding from the bottom surface of the board 14
2 is cut so that it does not protrude from the bottom surface of the board 14, and the mounting of the electronic component 11 on the board 14 is completed (FIG. 5).

Note that 17 in FIG. 5 is an insulating sheet pasted on the bottom surface of the board 14, which is connected to the lead wire 12 of the electronic component 11.
．． 12 is cut so as not to protrude from the bottom surface of the substrate 14, but is provided with the intention of preventing its tip from coming into contact with other objects, and may be provided if necessary. Bye.

In this manner, according to the mounting method of the present invention, electronic components can be mounted on the board without the lead wires protruding from the lower three surfaces of the board, so unnecessary get spaces can be removed.
Can be made smaller. In addition, the lead wires that exist in the through holes of the board ultimately have no electrical function, so
Even when used in high frequency circuits, unnecessary inductance can be minimized and the characteristics can be improved.

Furthermore, by minimizing the length of the lead wire, it is possible to increase the amount of unnecessary leads collected and reduce costs.

Note that the above description and drawings are examples for understanding the present invention, and the present invention is not limited thereto.

In particular, the electronic component is not limited to a capacitor, and the substrate may be anything that has a connecting electrode on at least the top surface, and there is no preclude the use of a device that has electrodes in the through hole or on the back surface.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example, Figs. 2 to 5 are views showing process examples of the mounting method of the present invention, Fig. 24- is a front view of an electronic component, and Fig. 3 is a diagram showing an electronic component held on a board. Fig. 4 is a sectional view showing the soldered state;
FIG. 5 is a sectional view showing a state in which the mounting is completed. 11-Electronic component 12-Lead wire 13-Protruding portion 14-Substrate 15-Connecting electrode 16-Through hole 11-Insulating sheet Patent applicant Murata Manufacturing Co., Ltd.

Claims (2)

[Claims] (1) When mounting an electronic component with a lead wire on a board having a through hole and a connection electrode formed on at least one surface including the through hole, attach the base of the lead wire of the electronic component or its vicinity in advance. A protrusion is formed with solder, the lead wire is inserted into the through hole from the side of the board on which the connection electrode is formed to lock the protrusion to the board, and then the protrusion is heated. A method for mounting an electronic component with a lead wire, characterized in that the solder is melted and solidified to prevent the lead wire from protruding from the narrow side of the board. (2) The method for mounting an electronic component with a lead wire according to claim (1), characterized in that, when heating the protruding portion, a load is applied to press the electronic component toward the substrate surface side.