JPH0529748A - High density mounting method for printed wiring board - Google Patents

Abstract

PURPOSE:To facilitate high density mounting on a printed wiring board by using an electronic parts which has a long-size lead. CONSTITUTION:A first long lead parts 5 is provided with long-size leads 6 each having a stopper 9, and the long-size leads 6 are inserted into through-holes 2a and 2b on a printed wiring board 1, so as to permit the stoppers 9 to engage with the upper surface of the printed wiring board 1 thus temporarily fixing the first parts 5. A second parts 7 and a third parts 8 which are both of low profile are attached near the surface of the printed wiring board, and as they are placed directly under the first part 5, they orthogonally cross with it. Between the first part 5 and the second and third parts, sufficient space is provided for the first part 5 to radiate heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a printed wiring board, and particularly to an electronic component mounted at a position distant from the surface of the printed wiring board and an electronic component mounted near the surface. The present invention relates to a high-density mounting method for a printed wiring board, which is mounted by combining three-dimensionally.

[0002]

2. Description of the Related Art In the conventional mounting technology, in order to reduce the size of the entire printed wiring board, a flat IC package is stacked on a chip resistance component with each electrode portion in contact with each other, or A method for realizing high-density mounting by using a sub printed wiring board on which a plurality of electronic components are mounted and vertically mounting the sub printed wiring board on a surface of a main printed wiring board, which is a base material, has been developed. However, all of them are limited to the case where there is a specific electrical connection condition between electronic components mounted in high density.

[0003]

According to the above conventional technique, as described above, the former chip resistor component and the flat IC are used.
In the package stacking method, the flat ICs arranged in the upper stage by connecting the electrodes of each component to each other.
In the latter method using a sub printed wiring board, a plurality of electronic components mounted on the sub printed wiring board are first electrically connected on the sub printed wiring board, and then the sub printing is performed. Since the lead terminals of the wiring board are connected to the main printed wiring board, electronic components mounted on the sub printed wiring board naturally have design restrictions. That is, in any of the above methods, it is not possible to mount a plurality of electronic components by combining them in a state where they do not electrically interfere with each other, and there is a problem that there is a large limitation in high-density mounting. there were.

The present invention has been made in view of the above problems of the prior art, and is the surface of an electronic component having a long lead (hereinafter referred to as "long lead component") and a printed wiring board. An object of the present invention is to perform high-density mounting of a printed wiring board by three-dimensionally combining electronic components mounted in the vicinity without contacting each other.

[0005]

In order to achieve the above object, a method for high-density mounting a printed wiring board according to the present invention is a method for mounting a long lead component on the printed wiring board, wherein To straddle the low-height components mounted on the mounting surface,
The long lead of the long lead component is fixed to the printed wiring board.

[0006]

According to the method of the present invention, a plurality of electronic components are three-dimensionally mounted on the printed wiring board without contacting each other.
That is, the long lead of the long lead component of the plurality of electronic components separates the component having a low height from the long lead component, and the two do not come into contact with each other.

[0007]

Embodiments of the present invention will be described with reference to the drawings.

1 and 2 are schematic partial plan views showing a printed wiring board before and after mounting in the present embodiment, respectively. The printed wiring board 1 has a pair of through holes 2a and 2b having circular lands. , And two pairs of through holes 3a, 3b and 4a, 4b with square lands. A long lead 6 of a first component 5 such as a high power resistor, which is a long lead component, is inserted into the through holes 2a, 2b, and the through holes 3a, 3b and 4a, 4b are inserted.
Is a second component such as a low power resistor, which is a low-height component that is mounted in close contact with the surface of the printed wiring board 1.
The leads of the component 7 and the third component 8 are inserted. As shown in FIG. 3, the long lead 6 of the first component 5 is the printed wiring board 1
Is provided with a stopper 9 that engages with the surface of the printed wiring board 1 and is temporarily fixed at a position separated from the surface of the printed wiring board 1 by a predetermined distance. The stopper 9 is formed by crushing a part of the long lead 6 from both sides to form a wide flat portion.

The second component 7 and the third component 8 are orthogonal to and immediately below the first component 5 (shown in FIG. 3).
The length of the long lead 6 of the first component 5 is set so that a sufficient space for heat radiation of the first component 5 is created between the first component 5 and the second component 7 and the third component 8. . First, above
In mounting the second and third components 5, 7, and 8 on the printed wiring board 1, first, the leads of the second component 7 and the third component 8 mounted near the surface of the printed wiring board 1 are mounted. , The parts 7 and 8 are temporarily fixed by inserting them into the through holes 3a, 3b, and 4a, 4b, respectively, and then the long lead 6 of the first part 5 is inserted into each of the through holes 2a, 2b to form a stopper. 9 is engaged with the upper end of each through hole 2a, 2b. After each component is temporarily fixed to the printed wiring board 1 as described above, the tips of the leads are fixed to the printed wiring board 1 by soldering. It should be noted that all the component mounting steps described above can be performed manually. Further, it is possible to perform all using an automatic mounting device, and it is also possible to combine both.

In the above embodiment, the second part 7 and the third part 8 are arranged in the direction orthogonal to the direction in which the first part 5 is arranged, but the leads adjacent to each other are required. As long as the distance can be maintained, it is not always necessary to arrange them in orthogonal directions. Further, when the length of the second component or the third component is shorter than that of the first component, it is also possible to dispose these immediately below or near the first component and in parallel with the first component. Further, in the above embodiment, the stopper 9 formed by flattening a part of the long lead 6 is used. However, by bending a part of the long lead and engaging this with the upper end of the through hole. It is also possible to temporarily fix the first component at a position away from the surface of the printed wiring board.

[0011]

Since the present invention is configured as described above, it has the following effects.

High-density mounting is possible by three-dimensionally mounting a plurality of electronic components on the printed wiring board, and therefore, the mounted printed wiring board can be downsized. Further, the cost of the mounted printed wiring board can be reduced by simplifying the fixing means of the electronic components to be mounted, and the electronic components can be mounted three-dimensionally without interfering with each other. Therefore, the entire high-density mounting process can be easily automated.

[Brief description of drawings]

FIG. 1 is a schematic partial plan view showing a part of a printed wiring board before mounting an electronic component in an embodiment of the present invention.

FIG. 2 is a schematic partial plan view showing a part of the printed wiring board after mounting the electronic component in the embodiment of the present invention.

3 is a schematic partial cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

1 printed wiring board 2a, 2b through hole 3a, 3b Through hole 4a, 4b through hole 5 First part 6 long lead 7 Second part 8 Third part 9 stopper

Claims (2)

[Claims] 1. When mounting a long lead component on a printed wiring board, the long lead of the long lead component is mounted so as to straddle a low-height component mounted on the mounting surface of the printed wiring board. A high-density mounting method for a printed wiring board, comprising fixing to the printed wiring board. 2. The high-density mounting method for a printed wiring board according to claim 1, wherein the long lead of the long lead component is fixed after mounting the component of low height.