JPH05136591A - Spurious radiation shield device - Google Patents

Abstract

PURPOSE:To provide a spurious radiation shield device which can do without a grounding spring and cope with the dispersion of a relative distance between a printed board and all the device by a method wherein a shield cover which can be easily mounted on the printed board and function as a grounding spring by its elasticity is introduced. CONSTITUTION:A shield device is composed of a printed board 1, mounting holes 1a bored in the board 1 at a pitch shorter than the overall length of a shield cover 6, a grounding pattern 1b provided onto the printed board 6, a shield cover 6 formed by curving a plate of bending elasticaity into a circular arc, an insertion part 6a located at the tip of the shield cover 6, contact cut-lift parts 6b, and an overall shield case 5. By this setup, a spurious radiation shield device lessened in part manufacturing man-hours and mounting man-hours can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unnecessary radiation shield device used in electric / electronic equipment.

[0002]

2. Description of the Related Art In recent years, there has been an urgent need to reduce unnecessary radiation in electric and electronic equipment, and an efficient shielding method has been demanded. In particular, in a circuit that handles high frequencies, it is common to enclose a printed circuit board with a shield, further enclose the entire interior of the device with an overall shield, and connect each shield with a ground spring or a lead wire.

A conventional unnecessary radiation shield device will be described below with reference to the drawings. As shown in FIGS. 6 and 7, the conventional unnecessary radiation shield device is composed of a printed circuit board 1 of a high frequency circuit, a shield cover 2 of the printed circuit board 1, an earth spring 3, a mounting screw 4, and an overall shield case 5. FIG. 7 shows an earth spring 3'having the unused shape of the earth spring 3.

With respect to the unnecessary radiation shield device including the above components, the relationship and operation of each component will be described below.

First, the shield cover 2 is attached to the printed circuit board 1 by inserting the tip into the hole of the printed circuit board 1 and further soldering. Ground spring 3 is screw 4
It is attached to the shield cover 2 by. By fixing the position of the printed circuit board 1 so that the distance between the shield cover 2 and the overall shield case 5 is smaller than the dimension a of the unused ground spring 3 ', the ground spring 3
The bending is spread out, and the shield case 5 is always pressed against the shield case 5 by the elastic force, so that the electrical connection between the shield cover 2 and the entire shield case 5 is obtained, so that the unnecessary radiation generated from the printed circuit board 1 is transmitted to the outside. It is possible to prevent leakage and prevent external noise from entering.

[0006]

However, in the above-mentioned conventional structure, a structure in which a ground spring is used to electrically connect the shield cover of the printed circuit board and the overall shield is generally used. Since it was necessary to bend the spring in advance, it was difficult to reduce the number of manufacturing steps as a single component.

Further, the earth spring is often attached to the shield cover mainly by screwing or soldering, and it has been difficult to reduce the number of assembling steps for the entire apparatus.

Furthermore, when some external force is applied during transportation of parts, the bent parts are used without being noticed in a state different from the designed size, or when the parts are different in size from each other, the printed circuit board may be damaged. If the total shield spacing is larger than the design size,
There was a problem that the earth spring and the overall shield might not contact.

The present invention solves the above-mentioned conventional problems, and provides an unnecessary radiation shield device capable of obtaining a sufficient shielding effect and capable of following changes in the relative distance between the printed circuit board and the overall shield. The purpose is to do.

[0010]

In order to achieve the above object, the unnecessary radiation shield device of the present invention forms a ground spring made of a conductive material having elasticity, and forms this in a shield case surrounding the entire set. It has a structure in which it is pressed and connected.

[0011]

According to the present invention, in the above-mentioned structure, the earth spring comes into contact with the entire shield due to its elastic force to perform the function of the earth spring to obtain a sufficient shielding effect, and the relative distance between the printed circuit board and the whole shield changes. Can be followed.

[0012]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the unnecessary radiation shield device of this embodiment has a printed circuit board 1, a mounting hole 1a formed in the printed circuit board 1, an earth pattern 1b on the printed circuit board 1, a shield cover 6, It is composed of an insertion portion 6a at the tip of the shield cover, a cut-and-raised portion 6b for contact with the ground pattern 1b, and the entire shield case 5.
The shape of the shield cover 6'when not in use is also shown.

With respect to the unnecessary radiation shield apparatus including the above components, the relationship and operation of each component will be described below with reference to FIGS. 1 and 2. First, the interval P between the mounting holes 1a on the printed circuit board 1 is made shorter than the dimension L of the shield cover 6'before mounting, and the insertion portion 6a is inserted into the mounting hole 1a, the earth spring 6'is bent in an arc shape. The ground spring 6 is shaped like the ground spring 6 and is fixed to the printed board 1 by its elastic reaction force, and the cut-and-raised portion 6b is always in contact with the ground pattern 1b of the printed board 1.

On the other hand, by determining the positional relationship between the printed circuit board 1 and the overall shield case 5 so that the overall shield case 5 contacts the arcuate outer peripheral portion of the shield cover 6, both parts are electrically connected. Therefore, an effective shield effect can be obtained without the need for a ground spring.

At this time, the positional relationship between the printed circuit board 1 and the overall shield case 5 can be varied within a range in which the shield cover 6 is in close contact with the overall shield case 5 and is crushed slightly, so that there is a degree of freedom in design. Even if the positional relationship among the components varies due to a large dimensional accuracy problem or the like, the variation can be absorbed by the deformation of the shield cover 6 itself.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 3 and 4, the unnecessary radiation shield apparatus of the second embodiment has a shield cover 6 provided with slits 6c, and the other points are the same as those of the first embodiment.

The operation of the second embodiment constructed as described above will be described below. First, by providing the slit 6c, the spring elasticity of the shield cover 6 can be changed, and the contact pressure generated between the shield cover 6 and the overall shield case 5 can be adjusted.

Even when the relative angle between these two parts changes, each part divided by the slit 6c deforms to keep the contact pressure substantially constant, thereby maintaining a stable electrical connection. can do.

FIG. 4 is an example in which the second embodiment is developed. The shape of the earth spring portion 6d protruding from the shield cover 6 and the shape of the shield cover 6 "when the shield cover 6 is not used. 6 shows the shape of the slit 6c '.

By changing the shape of the slit 6c in the second embodiment to a slit 6c ', when attaching the shield cover 6 to the printed circuit board 1, the earth spring portion 6d of the portion divided by the slit 6c'.
Tries to maintain a linear shape without being bent in an arc shape, this portion is used as an earth spring for the entire shield case 5.
It is also possible to contact with.

In this case, the printed circuit board 1 has the same outer dimensions as the shield cover 6 in the second embodiment.
It is possible to cope with a case where the distance between the shield case 5 and the entire shield case 5 is large.

That is, the shield cover 6 according to the present invention.
Can change the shape of the slit 6c even if only one type of external shape is used, so that
It is possible to deal with various positional relationships of.

The slits 6c "and the ground spring portions 6d 'in FIG. 5 may be alternately inserted.
In this case, the overall shape is as shown in FIG. 5, and the shielding effect can be enhanced by narrowing the opening.

[0026]

As is apparent from the above embodiments, according to the present invention, the earth spring is eliminated by introducing a shield cover which has a simple shape and structure and acts as an earth spring by its elasticity. Therefore, it is possible to reduce the number of man-hours for manufacturing parts and the number of mounting steps, and it is possible to realize an excellent unnecessary radiation shield device that can cope with all positional relationships between the printed circuit board and the overall shield even if one outer shape is changed.

[Brief description of drawings]

FIG. 1 is a perspective view of an unnecessary radiation shield device according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view of the shield device.

FIG. 3 is a perspective view of an unnecessary radiation shield device according to a second embodiment of the present invention.

FIG. 4 is a perspective view of an example of developing the second embodiment.

FIG. 5 is a perspective view of an example of developing the second embodiment.

FIG. 6 is a perspective view of a conventional unnecessary radiation shield device.

FIG. 7 is a partial sectional view of the shield device.

[Explanation of symbols]

 1 Printed circuit board 1a Mounting hole 5 Overall shield case 6 Shield cover 6a Insertion part 6b Cut and raised part

Claims (1)

[Claims] 1. An unnecessary radiation shield device in which an earth spring is integrally formed by using a conductive material having elasticity, and the earth spring is pressure-contacted and electrically connected to an entire shield case surrounding the entire set.