JPH0645774A - Electronic equipment printed board - Google Patents

Abstract

PURPOSE:To attenuate a vibration external force applied onto a printed board so as to protect an electronic part against damage and a wiring lead against disconnection by a method wherein a viscoelastic sheet is inserted between the plies of a laminated board main body respectively. CONSTITUTION:A board main body 1 is of laminated structure formed of resin composite material, and viscoelastic material sheets 3 of urethane rubber or polystyrene are interposed between plies of the laminated body 1. By this setup, vibrations acting on a printed board are absorbed and lessened in amplitude. Therefore, vibrations acting on an electronic part 4 and a wiring lead wire 5 provided onto the board body 1 are lessened in amplitude, so that not only the electronic part 4 can be protected gainst damage but also a wiring lead wire 5 can be protected against disconnection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board for electronic equipment on which electronic parts such as integrated circuits (hereinafter referred to as IC) are mounted.

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional printed circuit board for electronic equipment has a structure in which a substrate body 01 made of a laminated composite material such as glass / epoxy is supported by a metal frame 02 at the periphery and the like. The electronic component 04 such as an IC having the lead wire 05 for wiring is mounted on the substrate body 01.

[0003]

When an external vibration force is applied to the conventional printed circuit board described above, the printed circuit board vibrates and is used for wiring the electronic components 04 such as ICs arranged on the substrate body. Problems such as disconnection of the lead wire 05 may occur. In order to prevent this, it is necessary to reduce the amount of response of the printed circuit board to the external vibration force. Therefore, it is necessary to increase the rigidity of the frame that supports the substrate body or increase the number of places where the frame supports. However, in this case, there are disadvantages that the weight of the printed circuit board increases and the ratio of the frame occupying the board body increases, so that the space for arranging electronic components on the board body decreases.

An object of the present invention is to provide a printed circuit board for electronic equipment which can solve the above problems of the conventional printed circuit board for electronic equipment and prevent vibration fatigue.

[0005]

A printed circuit board for electronic equipment of the present invention is attached to at least one of a board body on which electronic components are mounted, a frame supporting the board body, and the board body and the frame. Equipped with viscoelastic material.

[0006]

When a vibration external force is applied to the printed circuit board of the present invention, the viscoelastic material attached to at least one of the board body and the frame absorbs the vibration, and the vibration level is reduced.

As a result, the electronic parts mounted on the substrate body are maintained in a state of not more than the vibration fatigue limit, and normal operation as an electronic device is ensured.

Further, it is not necessary to increase the rigidity of the frame or the number of places for supporting the board main body by the frame in order to cope with the external vibration force, the printed circuit board is lightened, and a space for arranging electronic parts on the board main body is provided. Is secured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, 1 is a substrate body of a printed circuit board, and 2 is a frame for supporting the substrate body 1. Further, 4 is an electronic component mounted on the substrate, and 5 is a lead wire for wiring the electronic component.

The substrate body 1 has a laminated structure of a resin composite material, and a plurality of viscoelastic material sheets 3 of urethane rubber, polystyrene or the like are interposed between the plies of each laminated body.

As the resin-based composite material constituting the substrate body 1, a thermosetting material is used. The substrate is formed by laminating together with the viscoelastic material sheet 3 by applying pressure and heat with an autoclave or the like. The body 1 is obtained.

As shown in FIG. 2, in order to make the viscoelastic material sheet 3 have a large attenuation factor in the applied frequency range, the resonance point of the laminated plate constituting the substrate body 1 is the viscoelastic material sheet 3 at the resonance point. It is set to be within the applicable frequency range.

At the same time, as shown in FIG. 3, the attenuation factor of the resin-based composite material main body also varies depending on the direction angle of the fibers forming the resin-based composite material. The orientation angle is also chosen to increase the damping factor.

In this embodiment, the viscoelastic material sheet 3 mounted between the laminated plies of the substrate body 1 absorbs the vibration received by the printed circuit board and lowers the vibration level. Further, the resin-based composite material whose fiber direction angle is selected as described above also contributes to absorption of vibration received by the printed circuit board.

Therefore, the level of vibration received by the electronic component 4 and its wiring lead wire 5 arranged on the substrate body 1 is lowered, and damage to the electronic component 4 and disconnection of the wiring lead wire 5 can be prevented. it can.

Further, since the viscoelastic material sheet 3 is arranged in the substrate body 1 to absorb the vibration, the rigidity of the frame 2 supporting the substrate body 1 is increased or the frame is used as the substrate. It is not necessary to increase the number of places to support the main body 1, and therefore the weight of the main body 1 of the substrate can be reduced, and a sufficient space for disposing the electronic component 4 on the main body 1 of the substrate can be secured.

By the way, in the conventional printed circuit board which does not include the viscoelastic material sheet 3, the resonance magnification (response vibration level / input vibration level) is usually about 30 times, but the viscoelastic material sheet 3 according to the present embodiment is used. In the printed circuit board which is provided and in which the fiber direction of the resin-based composite material is selected, the resonance magnification can be reduced to about 5 times.

The second embodiment of the present invention will be described with reference to FIG. In this embodiment, the substrate main body 1 and the frame 2 similar to those of the first embodiment are provided, but the viscoelastic material sheet 3 is not arranged in the substrate main body 1 and the upper and lower end portions of the frame 2 are arranged. I tried to paste it on.

Also in this embodiment, the same operation and effect as those of the first embodiment can be obtained.

A third embodiment of the present invention will be described with reference to FIG. This embodiment also includes a substrate body 1 and a frame 2 similar to those of the first embodiment, but the viscoelastic material sheet 3 is not placed in the substrate body 1 but is attached to the substrate body 1. I chose

In this embodiment, the viscoelastic material sheet 3 can be easily attached to the substrate body 1 of the printed circuit board prepared in advance, and in other points, it is different from the first embodiment. Similar actions and effects can be achieved.

Although the viscoelastic material sheet 3 is attached to either the substrate body 1 or the frame 2 in each of the above-mentioned embodiments, it may be attached to both.

[0024]

The printed circuit board for electronic equipment of the present invention includes a board body on which electronic components are mounted, a frame for supporting the board body, and a viscoelastic member attached to the board body or at least one of the frames. By including the above, it is possible to attenuate the external vibration force received by the printed circuit board, and prevent damage to the electronic component and disconnection of the wiring lead wire.

Further, since the external vibration force is absorbed by the viscoelastic member, it is not necessary to increase the rigidity of the frame or the place where the frame body is supported by the frame, and the printed circuit board can be made lightweight. At the same time, a space for arranging electronic components on the substrate body can be increased.

[Brief description of drawings]

1 shows a first embodiment of the present invention, FIG. 1 (a) is a plan view thereof, and FIG. 1 (b) is a sectional view taken along the line AA of FIG. 1 (a).

FIG. 2 is a damping frequency characteristic diagram of the viscoelastic material sheet of the first embodiment.

FIG. 3 is a characteristic diagram showing a relationship between a fiber direction angle and a vibration damping rate of the resin-based composite material according to the first embodiment.

FIG. 4 is a sectional view of a second embodiment of the present invention.

FIG. 5 is a plan view of the third embodiment of the present invention.

FIG. 6 shows a conventional printed circuit board for electronic equipment, and FIG.
6A is a plan view thereof, and FIG. 6B is a sectional view taken along the line BB of FIG. 6A.

[Explanation of symbols]

 1 Substrate Main Body 2 Frame 3 Viscoelastic Material Sheet 4 Electronic Component 5 Lead Wire for Wiring Electronic Component

Claims (1)

[Claims] 1. An electronic device comprising: a board body on which electronic components are mounted; a frame supporting the board body; and a viscoelastic material attached to at least one of the board body and the frame. Printed circuit board.