JP2020088277A - Electromagnetic shield structure and electronic apparatus - Google Patents

Abstract

To reduce leaked electromagnetic waves.SOLUTION: An electromagnetic shield structure includes: a first chassis 11 that has a first recess 110 and a step 112 formed along a side surface surrounding the first recess 110; a second chassis 12 that covers the first recess 110 at least a part of which is in contact with the first chassis 11; and a gasket 13 that is in contact with a horizontal surface of the step 112, wherein the volume of the gasket 13 when the first chassis 11 and the second chassis 12 are in contact with each other is smaller than the volume of the gasket 13 when the first chassis 11 and the second chassis 12 are not in contact with each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electromagnetic shield structure that houses an electronic circuit and an electronic device.

Conventionally, a gasket has been used to prevent unnecessary radio waves from leaking from an electronic device (see, for example, Patent Document 1).

JP, 09-162583, A

In the conventional shield structure, a gasket is attached to a place where a gap exists. Although the electromagnetic wave is attenuated by the gasket, there is a problem that the remaining electromagnetic wave leaks from the gap.

Then, this invention is made|formed in view of these points, and an object of this invention is to provide the electromagnetic shield structure and electronic device which can reduce the electromagnetic wave which leaks.

An electromagnetic shield structure according to a first aspect of the present invention includes a first chassis having a first recess and a step portion formed along a side surface surrounding the first recess, and at least a part of the first chassis. The gasket has a second chassis that covers the first recess by contacting the chassis, and a gasket that contacts the horizontal surface of the step portion, and the gasket in a state where the first chassis and the second chassis are in contact with each other. Is smaller than the volume of the gasket when the first chassis and the second chassis are not in contact with each other. The gasket may further contact a vertical surface of the step portion that is orthogonal to the horizontal surface.

In a state where the first chassis and the second chassis are not in contact with each other, the height of the gasket provided in the step portion may be larger than the height of the vertical surface in the step portion.

The first chassis has a first step portion and a second step portion formed along a side surface surrounding the first recess as the step portion, and the electromagnetic shield structure has a first step portion of the first step portion. A first gasket that is in contact with a horizontal surface and a first vertical surface that is orthogonal to the first horizontal surface, a second gasket that is in contact with the second horizontal surface of the second step portion, and a second vertical surface that is orthogonal to the second horizontal surface. And may be included.

The first step portion is formed inside the second step portion, and the height of the first gasket is the first vertical when the first chassis and the second chassis are not in contact with each other. The height of the second gasket may be smaller than the height of the surface, and the height of the second gasket may be larger than the height of the second vertical surface.

The first chassis may further include a third horizontal surface surrounding the second step portion, and the second chassis may have a fourth horizontal surface that contacts the second gasket while being in contact with the third horizontal surface. ..

The second chassis may have a fifth horizontal surface that contacts the first gasket in a state where the third horizontal surface and the fourth horizontal surface are in contact with each other. The second chassis may have a second recess provided at a position facing the first recess in a state of being in contact with the first chassis.

An electronic device according to a second aspect of the present invention includes a container having the electromagnetic shield structure according to any one of the above, and an electronic circuit housed in the container.

According to the present invention, there is an effect that the leaked electromagnetic waves can be reduced.

It is a figure which shows the state which decomposed|disassembled the electronic device. It is the sectional view on the AA line in the state with which the 1st chassis and the 2nd chassis were combined in the electronic device. It is a figure for demonstrating the detail of the peripheral part where the 1st gasket and the 2nd gasket are being fixed in the 1st chassis. It is a figure which shows the vicinity which contacts a 1st chassis in a 2nd chassis.

[Configuration of electronic device 1]
FIG. 1 is a diagram showing a state in which the electronic device 1 is disassembled. The electronic device 1 has a first chassis 11 and a second chassis 12. The first chassis 11 and the second chassis 12 function as a container for housing an electronic circuit in the internal space by being combined. The electronic device 1 further includes a first gasket 13 and a second gasket 14 provided between the first chassis 11 and the second chassis 12.

FIG. 2 is a cross-sectional view taken along the line AA in the electronic device 1 in a state where the first chassis 11 and the second chassis 12 are combined. FIG. 2 shows a cross section around one side wall in the vicinity of a position where the first chassis 11 and the second chassis 12 are in contact with each other. Since the electronic device 1 has the electromagnetic shield structure shown in FIG. 2, the amount of electromagnetic waves emitted by the electronic circuit housed in the electronic device 1 leaking to the outside can be reduced.

The first chassis 11 is, for example, a lower chassis and has a first recess 110 that houses an electronic circuit. The first chassis 11 is formed of a material containing metal, for example. A step portion is formed on the first chassis 11 along a side surface surrounding the first recess 110. Details of the stepped portion will be described later. The first chassis 11 has four side surfaces, ie, a surface, b surface, c surface, and d surface, and the connector 111 is provided on the c surface side. The connector 111 is, for example, an SMA connector for inputting a signal that controls a variable attenuator inside the electronic device 1.

The second chassis 12 is, for example, an upper chassis, and seals the electronic circuit housed in the first chassis 11 by contacting an annular surface formed around the first recess 110 in the first chassis 11. .. Further, the second chassis 12 may have a second recess (not shown) provided at a position facing the first recess 110 in a state where the first chassis 11 and the second chassis 12 are in contact with each other. In this case, the first recess 110 and the second recess form a space that accommodates the electronic circuit. The second chassis 12 is made of, for example, a material containing metal.

The first gasket 13 and the second gasket 14 are formed in an annular shape having a shape substantially similar to the outer peripheral shape of the first chassis 11 and the second chassis 12. The first gasket 13 and the second gasket 14 are fixed to the first chassis 11 by a conductive adhesive in a state of being in contact with the horizontal surface of the step portion formed on the first chassis 11. In the example shown in FIGS. 1 and 2, the first gasket 13 is fixed to the first chassis 11 inside the second gasket 14. Further, the first gasket 13 is fixed to the first chassis 11 at a position lower than the second gasket 14.

The first gasket 13 and the second gasket 14 are made of, for example, a conductive fiber and have elasticity. The first gasket 13 and the second gasket 14 are provided so as to be in contact with both the first chassis 11 and the second chassis 12 when the first chassis 11 and the second chassis 12 are in contact with each other.

The first gasket 13 and the second gasket 14 are sandwiched between the first chassis 11 and the second chassis 12 while the first chassis 11 and the second chassis 12 are in contact with each other, so that the first chassis 11 and the second chassis 12 The volume is smaller than when the and are not in contact. That is, the volumes of the first gasket 13 and the second gasket 14 in the state where the first chassis 11 and the second chassis 12 are in contact with each other are the same as those in the state where the first chassis 11 and the second chassis 12 are not in contact with each other. It is smaller than the volumes of 13 and the second gasket 14. Since the electronic device 1 is configured in this manner, a gap is not formed between the first gasket 13 and the second gasket 14 and the first chassis 11 and the second chassis 12, so that the inside of the electronic device 1 is The amount of leakage of the high frequency signal output from the electronic circuit can be reduced.

The first chassis 11 and the second chassis 12 are coupled by a plurality of screws 15. A horizontal step region is formed along the outer periphery of the outer surface of the second chassis 12, and a plurality of holes 121 are formed in the step region. The plurality of holes 121 are formed at equal intervals, for example. By inserting the screws 15 into the respective holes 121, the first chassis 11 and the second chassis 12 are fixed.

[Structure for fixing the first gasket 13 and the second gasket 14]
FIG. 3 is a diagram for explaining the details of the peripheral portion where the first gasket 13 and the second gasket 14 are fixed in the first chassis 11. FIG. 3A is a sectional view of the first chassis 11 in a state where the first gasket 13 and the second gasket 14 are not fixed to the first chassis 11. FIG. 3B is a cross-sectional view of the first chassis 11, the first gasket 13 and the second gasket 14 in a state where the first gasket 13 and the second gasket 14 are fixed to the first chassis 11.
FIG. 4 is a diagram showing the vicinity of the second chassis 12 in contact with the first chassis 11.

As shown in FIG. 3A, the first chassis 11 has a first step portion 112 and a second step portion 113 formed along the side surface surrounding the first recess 110. The first step portion 112 and the second step portion 113 each have a horizontal surface and a vertical surface. The width of the horizontal surface (first horizontal surface 112a) of the first step portion 112 is L1, which is larger than the width W1 of the first gasket 13. The width of the horizontal surface (second horizontal surface 113a) of the second step portion 113 is L2, which is larger than the width W2 of the second gasket 14. The height of the vertical surface (first vertical surface 112b) of the first step portion 112 is H1, and the height of the vertical surface (second vertical surface 113b) of the second step portion 113 is H2. The first step portion 112 is formed inside the first chassis 11 with respect to the second step portion 113.

As shown in FIG. 3B, the first gasket 13 is in contact with the first horizontal surface 112a of the first step portion 112 and the first vertical surface 112b orthogonal to the first horizontal surface 112a. It is fixed to. The second gasket 14 is fixed to the first chassis 11 so as to be in contact with the second horizontal surface 113a of the second step portion 113 and the second vertical surface 113b orthogonal to the second horizontal surface 113a.

In the example shown in FIG. 3B, when the first chassis 11 and the second chassis 12 are not in contact with each other, the height h2 of the second gasket 14 provided in the second step portion 113 is equal to the second step. It is larger than the height H2 of the second vertical surface 113b of the portion 113.

The first chassis 11 further includes a third horizontal surface 114 that surrounds the second step portion 113. As shown in FIG. 4, the second chassis 12 has a fourth horizontal surface 124 that is in contact with the second gasket 14 while being in contact with the third horizontal surface 114 when the first chassis 11 and the second chassis 12 are in contact with each other. Since the height h2 of the second gasket 14 is higher than the height H2 of the vertical surface of the second step portion 113, the second chassis 12 compresses the second gasket 14 by pressing the second gasket 14 by its own weight. The second chassis 12 is provided with the second gasket 14 such that the volume of the second gasket 14 is about 70% of the volume of the second gasket 14 when the first chassis 11 and the second chassis 12 are not in contact with each other. Compress.

The second chassis 12 also has a fifth horizontal surface 125 that contacts the first gasket 13 in a state where the third horizontal surface 114 and the fourth horizontal surface 124 are in contact with each other. In the state where the third horizontal plane 114 and the fourth horizontal plane 124 are in contact with each other, the distance between the fifth horizontal plane 125 and the first horizontal plane 112a is shorter than the height h1 of the first gasket 13 in the uncompressed state. is seperated. The distance between the fifth horizontal plane 125 and the first horizontal plane 112a is, for example, when the first chassis 11 and the second chassis 12 are in contact with each other, for example, when the volume of the first gasket 13 is the same. The compression distance is designed to be about 70% of the volume of the first gasket 13 in the state where and are not in contact with each other.

As described above, in the electronic device 1, since the electromagnetic shield structure of the present embodiment is provided in the electronic device 1, the leakage amount of electromagnetic waves is reduced. As a result, the electronic device 1 is less likely to affect external devices. Further, since the electric power value output by the electronic device 1 does not fluctuate due to the influence of electromagnetic waves, the adjustment accuracy in adjusting the output electric power value is improved.

[Modification]
In the above description, the example in which the first chassis 11 has a plurality of step portions is shown, but the first chassis 11 has only one of the first step portion 112 and the second step portion 113, and One of the gasket 13 and the second gasket 14 may be provided.

Further, in the above description, the example in which the first gasket 13 and the second gasket 14 are in contact with the horizontal surface and the vertical surface of the first step portion 112 and the second step portion 113 has been shown. The gasket 14 may not be in contact with the vertical surfaces of the first step portion 112 and the second step portion 113.

Further, in the above description, the example in which the first chassis 11 has the step portion is shown, but the second chassis 12 may have the step portion, and the gasket may be provided at the step portion. For example, the second chassis 12 has a step portion having the same shape as the first step portion 112 and the second step portion 113 formed on the first chassis 11 shown in FIG. The gasket may be fixed. Further, in the state shown in FIG. 2, instead of fixing the first gasket 13 and the second gasket 14 to the first chassis 11 with a conductive adhesive, the first gasket 13 and the second gasket 14 are not attached to the second chassis 12. It may be fixed to the substrate with a conductive adhesive.

[Effects of the electromagnetic shield structure of the present embodiment]
As described above, in the electronic device 1, the first gasket 13 is fixed so as to be in contact with the horizontal surface of the first step portion 112 formed in the first chassis 11, and the first gasket 13 is in contact with the horizontal surface of the second step portion 113. The second gasket 14 is fixed. Then, the second chassis 12 is covered with the first chassis 11 so that the outer peripheral portion of the first chassis 11 and the outer peripheral portion of the second chassis 12 are in contact with each other, and the first gasket 13 and the second gasket 14 Is smaller than the volume in the state where the first chassis 11 and the second chassis 12 are not in contact with each other.

Since the electronic device 1 is configured in this manner, there is no gap between the first gasket 13 and the second gasket 14 and the first chassis 11 and the second chassis 12, so that electromagnetic waves generated in the electronic circuit are generated. , And becomes difficult to be propagated to the outside beyond the first gasket 13 and the second gasket 14. Furthermore, since the first gasket 13 and the second gasket 14 are fixed in contact with the vertical surfaces of the first step portion 112 and the second step portion 113, respectively, the first gasket 13 and the second gasket 14 pass through the first gasket 13 and the second gasket 14. The component of the generated electromagnetic wave is reflected by the vertical surface and returns to the first gasket 13 and the second gasket 14. As a result, it becomes more difficult for electromagnetic waves to propagate to the outside.

In addition, since the first gasket 13 is provided below and inside the electronic device 1 with respect to the second gasket 14, even if electromagnetic waves pass through the first gasket 13, residual electromagnetic waves are generated by the second gasket 14. It is prevented from leaking. As described above, since the plurality of gaskets are provided at different positions, it becomes more difficult for electromagnetic waves to leak.

Further, since the elastic first gasket 13 and the second gasket 14 are provided, the influence of the processing error of the step portion and the unevenness of the surface is suppressed, and the processing of the first chassis 11 and the second chassis 12 and Positioning becomes easy.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist thereof. is there. For example, the specific embodiment of the distribution/integration of the device is not limited to the above-described embodiment, and all or a part thereof may be functionally or physically distributed/integrated in arbitrary units to be configured. You can Further, a new embodiment that occurs due to an arbitrary combination of a plurality of embodiments is also included in the embodiment of the present invention. The effect of the new embodiment produced by the combination has the effect of the original embodiment.

1 Electronic Equipment 2 Power Supply 3 Horn Antenna 4 Spectrum Analyzer 5 Signal Generator 11 First Chassis 12 Second Chassis 13 First Gasket 14 Second Gasket 15 Screw 110 First Recess 111 Connector 112 First Step 113 Second Step 114 Third horizontal surface 121 Hole 124 Fourth horizontal surface 125 Fifth horizontal surface

Claims (9)

A first chassis having a first recess and having a step portion formed along a side surface surrounding the first recess;
A second chassis that covers the first recess by contacting at least a part of the first chassis;
A gasket in contact with the horizontal surface of the step portion,
Have
The volume of the gasket in a state where the first chassis and the second chassis are in contact with each other is smaller than the volume of the gasket in a state where the first chassis and the second chassis are not in contact with each other. Electromagnetic shield structure. The gasket is further in contact with a vertical surface orthogonal to the horizontal surface in the step portion.
The electromagnetic shield structure according to claim 1. In a state where the first chassis and the second chassis are not in contact with each other, the height of the gasket provided in the step portion is larger than the height of the vertical surface in the step portion,
The electromagnetic shield structure according to claim 2. The first chassis has a first step portion and a second step portion formed along a side surface surrounding the first recess as the step portion.
The electromagnetic shield structure is
A first gasket in contact with a first horizontal surface of the first step portion and a first vertical surface orthogonal to the first horizontal surface;
A second gasket in contact with a second horizontal surface of the second step portion and a second vertical surface orthogonal to the second horizontal surface;
Characterized by having,
The electromagnetic shield structure according to any one of claims 1 to 3. The first step portion is formed inside the second step portion,
In a state where the first chassis and the second chassis are not in contact with each other, the height of the first gasket is smaller than the height of the first vertical surface, and the height of the second gasket is smaller than that of the second vertical surface. Characterized by being larger than height,
The electromagnetic shield structure according to claim 4. The first chassis further has a third horizontal surface surrounding the second step portion,
The second chassis may include a fourth horizontal surface that contacts the second gasket while being in contact with the third horizontal surface.
The electromagnetic shield structure according to claim 4 or 5. The second chassis has a fifth horizontal surface that contacts the first gasket in a state where the third horizontal surface and the fourth horizontal surface are in contact with each other,
The electromagnetic shield structure according to claim 6. The second chassis has a second recess provided at a position facing the first recess in a state of being in contact with the first chassis.
The electromagnetic shield structure according to any one of claims 1 to 7. A container having the electromagnetic shield structure according to any one of claims 1 to 8,
An electronic circuit housed in the container,
An electronic device comprising: