JP2000165080A - Shield for electronic circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield for electronic circuit in which the structure and shape of a shield plate are simplified while enhancing the impact resistance drastically. SOLUTION: A square hole 42 is made at a specified position in the side face of a second shield plate 41. A protrusion 33 projecting outward is provided at a position on the side face of a first shield plate 31 (on the inside of the side face part of the second shield plate 41) corresponding to the hole 42 in the second shield plate 41. The side face parts of the first and second shield plates 31, 41 are secured each other by sliding the protrusion 33 from the lower edge of the side face part of the second shield plate 41 to the inside thereof and fitting the protrusion 33 into the hole 42 in the second shield plate 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield device for an electronic circuit used in electronic equipment such as a mobile communication terminal.

[0002]

2. Description of the Related Art In a mobile communication terminal, for example, a PHS (Personal Handy Phone System) telephone, FIG.
As shown in FIG. 1, first and second shield plates 12 and 13 are provided to cover both surfaces of the high-frequency circuit board 11. In this case, the first and second shield plates 12 and 13 are fixed to each other at the peripheral portion, and are further positioned to each other in the lateral direction.

Conventionally, first and second shield plates 12 and 13
As shown in FIG. 6, a plurality of protrusions 14 are provided on the side surface of the first shield plate 12,
The second shield plate 13 is provided by providing a plurality of fixing feet 15 on the side end thereof, providing a claw portion 16 at the tip thereof, and engaging the claw portion 16 with the protrusion 14. In order to position each other in the horizontal direction, projections 17 are provided at the four corners of the first shield plate 12, while notches 18 are provided at the four corners of the second shield plate 13. 17 is engaged.

[0004]

However, in the conventional method as described above, a locking mechanism (fixing mechanism) including the projection 14 and the fixing foot 15 and a positioning structure including the projection 17 and the notch 18. Of the first and second shield plates 1
Since the first and second shield plates 12 and 13 need to be provided on the first and second shield plates 13 and 13, the shape and structure of the first and second shield plates 12 and 13 become very complicated. In addition, since the effect of each lock mechanism is small, a large number of lock mechanisms are required, so that the shapes and structures of the first and second shield plates 12 and 13 become more complicated. There was a problem that the mechanism could not be made too large and the number of pieces was limited, so that the impact resistance was insufficient.

[0005] The present invention has been made in view of the above points,
An object of the present invention is to provide an electronic circuit shield device in which the structure and shape of a shield plate are simplified and the shock resistance is dramatically improved.

[0006]

According to the present invention, there is provided an electronic circuit shield device comprising: a first shield plate provided with a projection on at least one side surface; and a hole formed in at least one side surface of the second shield plate. And the first and second shield plates are fixed to each other by fitting the protrusion into the hole. In this electronic circuit shield device, the edge of the side surface of the second shield plate is inclined to easily slide the projection of the first shield plate into the hole from the edge through the side surface. Is preferred. In addition, a V-shaped or U-shaped portion is provided on the edge of the side portion of the second shield plate to position the projection of the first shield plate at the position of the hole.
It is preferable to have a U-shaped recess. Further, it is preferable that the side surface portion of the second shield plate having the hole formed is cut off from the other side surface portion to form a narrow spring piece. Further, when the projection is slid into the hole from the edge of the side surface of the second shield plate, it is preferable that the portion of the projection corresponding to the edge of the side surface of the second shield plate is formed on the oblique side.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a shield device for an electronic circuit according to the present invention. The embodiment of the present invention is a case where the shield device of the present invention is used for a high-frequency circuit board of a PHS telephone.

FIG. 2 is a schematic exploded perspective view of a PHS telephone for explaining an embodiment of the present invention. In this figure, 21 is a front case, 22 is a back case, and a circuit board is accommodated in these front and back cases 21 and 22. The circuit board includes a long main circuit board 23 and a short high-frequency circuit board 24. The high frequency circuit board 24 is provided with shield plates 31 and 41 on both surfaces. High frequency circuit board 24
Of the first shield plate 31 provided on the lower surface of the mounting plate 32 are attached to three sides (one penetrates the high-frequency circuit board 24).
Are fixed to the main circuit board 23 by soldering the mounting feet 32 to ground terminals of the main circuit board 23. By this fixing, the high-frequency circuit board 24 is also fixed to the lower surface of the main circuit board 23 at the same time.
The second shield plate 41 is provided on the upper surface of the high-frequency circuit board 24 and is soldered to a ground terminal of the high-frequency circuit board 24. Further, the second shield plate 41 and the first shield plate 31 are fixed to each other at the side surface of the side end.

For this fixing, FIGS. 1 (a) and 1 (b)
(A) is a perspective view before fixing, and (b) is a perspective view in a fixed state. As shown in an enlarged manner, a square hole 42 is provided at a predetermined position on a side surface of the second shield plate 41. Is formed.
The side surface portion of the second shield plate 41 in which the hole 42 is formed is separated from the other side surface portion by a cut 43 to form a narrow spring piece 44. In contrast, the first
The outer side of the shield plate 31 (entering the inside of the side surface of the second shield plate 41) projects outward at a position corresponding to the hole 42 of the second shield plate 41.
3 are provided. This projection 33 is connected to the second shield plate 41
1 is slid from the lower edge of the side portion of the side to the inside of the side portion.
As shown in (b), the side surfaces of the first and second shield plates 31 and 41 are fixed to each other by fitting into the holes 42 in the side surfaces of the second shield plate 41. Further, the engagement between the first shield plate 31 and the second shield plate 41 on the side facing the spring piece 44 side shown in FIG.
This is a structure similar to that shown in FIG. still,
As one embodiment of the present invention, the engagement of the first and second shield plates 31 and 41 on the side facing the spring piece 44 side is performed on a part of the side surface of the first shield plate 31 similarly to the related art. A structure may be used in which a protrusion is provided and fixed by engagement with a fixing foot formed on the second shield plate 41.

At this time, in order to facilitate sliding of the projection 33, a perspective view of FIG. 3, a front view of FIG.
As shown in the side view of (b), the lower edge 45 of the side surface of the second shield plate 41 may be inclined outward.

As shown in FIGS. 3 and 4, the second
A V-shaped (or U-shaped) concave portion 46 is formed at the lower edge of the side surface of the shield plate 41.
Is automatically positioned immediately below the hole 33, so that the projection 33 is easily fitted into the hole 42.

Further, when the projection 33 slides in,
By forming the upper edge of the projection 33 in contact with the lower edge of the side surface of the shield plate 41 on the oblique side 34 as shown in FIG. 5, the projection 33 can be more easily slid.

As described above, the protrusion 33 and the hole 42 are provided.
According to the structure in which the side surface of the first shield plate 31 and the side surface of the second shield plate 41 are fixed by fitting, the first shield plate 31 and the second shield plate can be fixed by one kind of fixing means. 41 can be fixed in a direction perpendicular to the substrate 24, and the first shield plate 31 and the second shield plate 41 can be fixed to the substrate 24.
And can be positioned in the parallel direction. That is, the locking mechanism and the positioning structure are integrated, and as a result, the shapes and structures of the first and second shield plates 31, 41 can be simplified. In addition, the shock resistance that the first shield plate 31 and the second shield plate 41 do not come off due to an impact such as a drop is dramatically improved. Further, as a result of the remarkable improvement in impact resistance, the number of fixing means can be reduced, and the shape and structure of the first and second shield plates 31 and 41 can be simplified from this point as well. . Furthermore, even with a small shield plate, sufficient impact resistance can be obtained with a small number of fixing means. If the impact resistance is improved, the reliability of the electronic device (PHS telephone in the embodiment) can be improved. Further, if the shape and structure of the shield plate are simplified, the manufacture of the shield plate becomes easy and the cost can be reduced, and the shield device is suitable for a small electronic device such as a PHS telephone.

Further, as shown in FIGS. 3 to 5, the second
The inclined portion or the concave portion 4 is formed on the side portion of the shield plate 41
If the oblique side 34 is formed, the fitting of the projection 33 to the hole 42 becomes easy, and workability is improved. Further, by forming the side surface portion of the second shield plate 41 in which the hole 42 is formed in the narrow spring piece 44, the fitting becomes easy and the workability is improved.

In the above embodiment, the shield device of the present invention is used as a shield of a high-frequency circuit board of a mobile cellular phone including a PHS telephone. It can be widely used not only for terminals but also for other electronic devices.

[0016]

As described above in detail, according to the electronic circuit shield device of the present invention, the structure and shape of the shield plate are simplified, and the shield device is suitable for small electronic equipment such as mobile telephone terminals. In addition, the manufacturing of the shield plate is facilitated, the cost can be reduced, and the shock resistance is dramatically improved, so that the reliability of the electronic device can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B show a fixing portion of a shield plate according to an embodiment of the present invention, wherein FIG. 1A is a perspective view showing a state before fixing, and FIG.
Is a perspective view in a fixed state.

FIG. 2 is a schematic exploded perspective view of the PHS telephone for explaining the embodiment of the present invention.

FIG. 3 is a perspective view showing another example of a fixing portion of the shield plate in the embodiment of the present invention.

FIGS. 4A and 4B show another example of the second shield plate side surface portion in the embodiment of the present invention, wherein FIG. 4A is a front view and FIG.

FIG. 5 is a side view showing another example of the protrusion according to the embodiment of the present invention.

FIG. 6 is an exploded perspective view for explaining a conventional method of fixing a shield plate.

[Explanation of symbols]

 31 First shield plate 33 Projection 41 Second shield plate 42 Hole 43 Notch 44 Spring piece

Claims (7)

[Claims] 1. A projection is provided on at least one side of a first shield plate, and a hole is provided on at least one side of a second shield plate, and the projection is fitted into the hole. A shield device for an electronic circuit, wherein a first and a second shield plate are fixed to each other. 2. An edge portion of a side portion of the second shield plate,
2. The shield device for an electronic circuit according to claim 1, wherein the first shield plate is inclined to easily slide the projection of the first shield plate into the hole portion from the edge portion through the side surface. 3. A V-shaped or U-shaped recess at the edge of the side surface of the second shield plate for positioning the projection of the first shield plate at the position of the hole. The shield device for an electronic circuit according to claim 1 or 2, wherein: 4. A side face portion of the second shield plate having a hole formed therein is formed into a narrow spring piece by being cut off from the other side surface portion. 3. The shield device for an electronic circuit according to any one of 3. 5. A projection portion corresponding to an edge of a side portion of the second shield plate when the projection is slid from the edge of the side portion of the second shield plate into the hole is formed on an oblique side. An electronic circuit shield device according to claim 1. 6. The circuit according to claim 1, wherein the first shield plate is provided on the first surface side of the circuit board, and the second shield plate is provided on the second surface side of the circuit board. The shield device for an electronic circuit according to any one of the above. 7. The shield device for an electronic circuit according to claim 6, wherein the circuit board is a high-frequency circuit board of a mobile communication terminal or another circuit board.