JPH0763114B2 - High frequency shield - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency shield device for use in a wireless communication device and the like, and more particularly to a high frequency shield device for providing a shield to prevent wraparound between high frequency devices in a circuit board due to unwanted radiation.

[0002]

2. Description of the Related Art In a conventional radio communication device, a high frequency signal processing circuit, for example, oscillation of another circuit caused by wraparound due to unnecessary radiation (radio wave leakage) from an oscillation circuit, and malfunction due to noise mixing are prevented. In order to obtain stable operation, the oscillator circuit is shielded. As this shield, there is a partition structure in which known metal plates are joined. In order to shield devices such as a high-frequency amplifier circuit, an oscillator circuit, and a control circuit, this is surrounded by a metal plate with one end soldered to the ground pattern of a mounting circuit board on which electronic components are mounted.

Further, in a power amplifier circuit, etc., which has a large amount of unwanted radiation and is liable to cause a malfunction in a control circuit, in order to obtain a strict shield effect, it is surrounded by a partition metal plate having one end soldered to a ground pattern and at the Is also a shield device that is covered with a metal plate. The metal plate, for example, a copper plate for partitioning, which has been plated with silver, is fixed at its end portion with screws, rivets, or the like. Further, the ends of the copper plates for partitioning to be joined are soldered to be connected and fixed.

In addition to this structure, a metal case made by die drawing or the like is put on a device on a circuit board for which a shield is desired, and a projection from a member around the opening is soldered to a ground pattern. ing. As described above, even with the conventional shield structure, desired devices and circuits can be shielded.

[0005]

However, in the conventional high-frequency shield structure described above, the former is
Since the end portions of the members are connected and fixed by rivets, soldering, etc., there are disadvantages that many members are used, the structure is complicated, the working process is complicated, and the cost is increased. Further, in the latter case, the metal case formed by the die drawing has a square column shape or a round column shape, and the circuit board cannot be partitioned into a desired complicated shape, for example, an L shape. For this reason, when the circuit board is divided into a large number and shielded,
It has the disadvantage of requiring a large space.

As an improved version of this type of high-frequency shield, "microwave device" disclosed in JP-A-62-219697, "electromagnetic shield structure for communication equipment" disclosed in JP-A-63-300599, Kaisho 63-200
The "electromagnetic shield structure of communication device" and the like shown in Japanese Patent No. 397 can be mentioned, but all of them have the same disadvantages as described above.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-frequency shield device which enables a complicatedly divided shield structure with a simple structure and obtains a reliable shield effect. .

[0008]

In order to achieve the above object, the present invention provides a shield member between a circuit board on which a plurality of electronic components are mounted and a metal cover covering the circuit board. In a high-frequency shield device for shielding between a plurality of electronic components, a protrusion is provided on a ground pattern or a cover of a circuit board, and a through hole of one side portion of the shield member using an elastic member is press-fitted into the protrusion, and the shield is provided. When the circuit board and the cover are attached, the other end of the member comes into contact with the ground pattern of the circuit board or the cover to shield the circuit board.

In this structure, the projection is provided inside the cover to press-fit the through hole in the one side portion of the shield member, and the other end of the shield member elastically contacts the ground pattern on the circuit board, and The ground pattern and the through hole of the circuit board are connected to the entire ground pattern provided on the opposite side surface of the circuit board.

Further, a slit is provided at the other end of the shield member elastically abutting the ground pattern on the circuit board so as to be orthogonal to the ground pattern surface on the circuit board.

Further, the shield member is provided with a U-shaped portion, a U-shaped portion, an L-shaped portion, or a combination thereof from the end of the flat portion into which the protrusion is press-fitted, and the portion of this portion is combined. The end portion is configured to extend orthogonally to the flat portion.

[0012]

In the high-frequency shield device of the present invention having the above-mentioned structure, the through-hole of one side of the shield member using the elastic member is press-fitted into the protrusion of the cover, and the other end of the shield member is connected to the circuit board. When the cover is attached, the circuit board is shielded by abutting against the ground pattern of the circuit board or the cover. For this reason, it is not necessary to fix by screwing, riveting, or soldering, and it is possible to construct a complicatedly divided shield structure with a simple structure and obtain a reliable shield effect.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the high frequency shield device of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a partial cross-section of the configuration of an embodiment of the high-frequency shield device of the present invention, and FIG. 2 is a cross-sectional view showing the main parts of FIG. 1 and 2, in this example, a chassis 2, a metal shield cover 3 whose edge portion fits into the chassis 2 with an uneven portion, and the chassis 2 and the shield cover 3 are arranged inside the chassis 2 and And a circuit board 6 for surface mounting, which is fixed by screwing or fastening with rivets or the like. A ground pattern 6a is provided on the entire surface of the circuit board 6 on the chassis 2 side.

Further, in this example, devices for high frequency signal processing, for example, a flat package type transmission circuit device 8a and reception system circuit device 8 are provided on the circuit board 6.
A shield portion 12 is provided between b and the transmission system circuit device 8a and the reception system circuit device 8b to prevent the unwanted radiation from the transmission system circuit device 8a from wrapping around.

As shown in the main part of FIG. 2, the shield portion 12 is elastically arranged in the shield portion between the transmission system circuit device 8a and the reception system circuit device 8b, and the shield plate 14 is provided. have. Further, the shield part 12 is provided inside the shield cover 3 and is provided on the circuit board 6 with a plurality of protrusions 3a into which the holes in the upper part of the shield plate 14 illustrated in FIG.
The lower end of the shield plate 14 in the drawing has a ground portion 6b that elastically abuts. Ground part 6b
Is the ground pattern 6c on the surface mounting side of the circuit board 6.
And the ground pattern 6a on the back surface are connected by a through hole 6d.

Next, the detailed structure of the shield plate 14 will be described. FIG. 3 is a perspective view showing a detailed configuration of the shield plate 14. In FIG. 3, in this example, the cross section is formed into two substantially U-shapes from the upper portion 14a press-fitted into the protrusion 3a of the shield cover 3 toward the lower portion 14b. The upper portion 14a has through holes 16a, 16b, 16 in which four slotted portions are provided in the shape of a figure.
c and 16d are linearly provided. Further, the lower portion 14b is provided with slits 18a, 18b, 18c, 18d for ensuring contact with the ground pattern 6c.

Next, the operation and function of the high-frequency shield device having this structure will be described. 1 to 3, in the five protrusions 3a provided inside the shield cover 3,
Through holes 16a to 16d provided in the upper portion 14a of the shield plate 14 shown in FIG. 2 are press-fitted and fixed by four peripheral slits. In this way, the shield cover 3
When the shield cover 3 is attached to the chassis 2 with the shield plate 14 fixed inside, the end of the lower portion 14b of the shield plate 14 is connected to the ground pattern 6c on the circuit board 6.
Elastically abut.

In this case, the ground pattern 6c is connected to the ground pattern 6a on the back surface through the through hole 6d. That is, the transmission circuit device 8a on the circuit board 6
And the receiving circuit device 8b are shielded. Further, the lower portion 14b is provided with slits 18a to 18d, and by the slits 18a to 18d,
The lower portion 14b is subtly displaced corresponding to the unevenness of the ground pattern 6c, and the lower portion 14b surely contacts the ground pattern 6c. In this case, the slits 18a to 1
It is advisable to change the width of 8d according to the unevenness of the ground pattern 6c.

Next, a modification of the shield plate 14 will be described. FIG. 4 shows a shield plate 20 having an L-shaped portion.
5 is a perspective view showing the configuration of FIG. 5, and FIG. 5 is a perspective view showing the configuration of the shield plate 24 having a dogleg-shaped portion. Figure 4
In, the shield plate 20 is formed with two L-shaped sections in cross section from the upper section 21a to the lower section 21b. The upper portion 21a has through-holes 22a and 22b in which four slotted portions are provided in the shape of a dozen.
Are provided in a straight line. Further, the lower portion 21b is provided with slits 23a and 23b for ensuring contact with the ground pattern 6c shown in FIG. The function of the shield plate 20 is similar to that of the shield plate 14.

In FIG. 5, the shield plate 24 is formed with a substantially V-shaped cross section from the upper part 24a to the lower part 24b. The upper portion 24a has a through-hole 2 in which four slotted portions are provided in a dove shape.
5a and 25b are linearly provided. Further, the lower portion 24b is provided with a slit 26a for ensuring contact with the ground pattern 6c shown in FIG. The function of the shield plate 24 is similar to that of the shield plate 14.

Although the shield plates 14, 20, 21 are formed in a linear shape, the present invention is not limited to this, and the area of the transmission system circuit device 8a and the reception system circuit device 8b in FIG. It may be modified according to the arrangement position and the like. That is, the shield cover 3 and the circuit board 6
With a variety of mounting states such as U-shape and L-shape, the desired device and circuit can be shielded with a space-saving and simple structure. In this case, the arrangement can be freely changed by changing the intervals between the through holes 16a to 16d and the slits 18a to 18d.

[0022]

As described above, according to the high frequency shield device of the present invention, the through hole of the one side portion of the shield member using the elastic member is press-fitted into the protrusion of the cover and the other end of the shield member is inserted. , When the circuit board and the cover are attached, the circuit board is shielded by abutting against the ground pattern of the circuit board or the cover, so that it is not necessary to fix it by conventional screwing or riveting or soldering. A shield structure that is complicatedly divided by a simple configuration is possible, and a reliable shield effect can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing a partial cross-section of the configuration of an embodiment of a high-frequency shield device of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a main part in FIG.

3 is a perspective view showing a detailed configuration of a shield plate in FIG. 1. FIG.

FIG. 4 is a perspective view showing a configuration of a shield plate having an L-shaped portion of a modified example in the embodiment.

FIG. 5 is a perspective view showing a configuration of a shield plate having a dogleg-shaped portion of a modified example in the embodiment.

[Explanation of symbols]

 2 chassis 3 shield cover 3a protrusions 6a, 6c ground pattern 6b ground portion 6d through hole 12 shield portion 14 shield plate 14a upper portion 14b lower portion 16a to 16d through hole 18a to 18d slit

Claims (4)

[Claims] 1. A high frequency shield device for shielding between a plurality of electronic components by disposing a shield member between a circuit board on which a plurality of electronic components are mounted and a metal cover that covers the circuit board, Providing a protrusion on the ground pattern or cover of the circuit board,
A through hole in one side of the shield member using an elastic member is press-fitted into this protrusion, and the other end of the shield member is attached to the ground pattern or cover of the circuit board when the circuit board and the cover are attached. A high-frequency shield device, which abuts and shields the circuit board. 2. A protrusion is provided inside the cover to press-fit a through hole in one side portion of the shield member, and the other end of the shield member elastically abuts a ground pattern on the circuit board, and a circuit. The high-frequency shield device according to claim 1, wherein the high-frequency shield device is connected to the entire-surface ground pattern provided on the opposite side surface of the circuit board through the ground pattern and the through hole of the board. 3. The slit according to claim 1, wherein the other end portion of the shield member elastically abutting against the ground pattern on the circuit board is provided with a slit perpendicular to the ground pattern surface on the circuit board. High frequency shield device. 4. The shield member is provided with a U-shaped portion, a U-shaped portion, an L-shaped portion, or a combination thereof from the end of the flat portion into which the projection is press-fitted, and a portion of this portion. The high-frequency shield device according to claim 1, wherein the end portion extends perpendicularly to the plane portion.