JPH09307258A - Shielding case of high-frequency equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shielding case of high-frequency equipment capable of surely suppressing any locally transmitted signal from a circuit part on a substrate without providing any protruding part out of a cover surface. SOLUTION: In an shielding case provided with a substrate 1 packaged with a circuit part, a frame body 2 containing this substrate 1 and the inside of the frame body 2 divided into a plurality of partition boards 2 as well as an upper cover 11 electrically shielding this frame body by covering an aperture part of the frame body 2, the upper cover 11 has a slope tapering off downward from the surface thereof in the direction of the substrate 1 while a pair of protruding pieces 15 are formed by boring a through hole 14 in the bottom of said slope 12, so that the partition boards 3 and the upper cover 11 may be electrically connected by engaging the protruding pieces 15 with a protrusion 3a protruding from the partition board 3 as well as positioning the protrusion 3a in the space inside the slope 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield case for a high frequency device such as a tuner for a television receiver which uses a high frequency circuit.

[0002]

2. Description of the Related Art Generally, in a high-frequency device using a high-frequency circuit, a plurality of insides of a frame body are provided in order to obtain circuit characteristics and at the same time prevent an adverse effect due to leakage of a local oscillation signal (OSC signal) to other circuits. The partition plate is divided, and the opening surface of the frame is covered with a cover to electrically shield the frame.

FIG. 9 is a plan view showing a main part of a shield case of a conventionally known high-frequency device, and FIG. 10 is an A of FIG.
It is a cross-sectional view taken along line A, which is described in Japanese Utility Model Laid-Open No. 59-81088. In these figures, 1 is a substrate on which circuit components (not shown) are mounted, 2 is this substrate 1
A partition for partitioning the interior of the frame 2 into a plurality of rooms, 4 an upper cover for covering the upper opening of the frame 2, 5 a lower cover for covering the lower opening of the frame 2, 6 It is solder that connects the substrate 1 and the partition plate 3. By cutting and raising a part of the upper cover 4 inward, a tongue piece 7 elastically contacting the end of the partition plate 3 is integrally formed, and a cut-and-raised hole 8 is formed around the tongue piece 7. Has been drilled. The outer periphery of the tongue piece 7 except the root portion 7a is cut off and inclined toward the substrate 1 side, and the tip end portion 7b of the tongue piece 7 abuts on the end portion of the partition plate 3. In the shield case of the high-frequency device configured in this way, the upper cover 4
When the top opening of the frame body 2 is covered with the tongue piece 7, the tip end portion 7b of the tongue piece 7 is elastically contacted with the end portion of the partition plate 3 to be grounded, so that the local transmission signal emitted from the high frequency device is transmitted through the upper cover 4. It is possible to suppress reaching other electronic components.

FIG. 11 is a plan view showing a main part of a shield case of a high-frequency device known as another conventional example, and FIG.
11 is a sectional view taken along the line BB of FIG. 11, in which the same parts as those shown in FIGS. 9 and 10 described above are designated by the same reference numerals.

In the shield case shown in FIG. 11, a cross-shaped cut hole 10 is formed in the upper cover 9, and a projection 3a projecting from the upper end of the partition plate 3 is fitted into the cut hole 10. These points are different from those shown in FIG. 9 described above. Even in the shield case of the high-frequency device configured as described above, when the upper cover 9 is covered on the upper opening of the frame body 2 while aligning the position of the upper cover 9, the partition plate 3
Since the protrusion 3a is fitted into the cutout hole 10 of the upper case 9 to be grounded, it is possible to suppress the local transmission signal emitted from the high-frequency device from reaching the other electronic components via the upper cover 4.

[0006]

Problems to be Solved by the Invention
In the case of the conventional shield case for high-frequency equipment, the tongue piece 7
By elastically contacting the end portion 7b of the partition 7 with the end portion of the partition plate 3,
Although it is possible to suppress the local transmission signal emitted from the high frequency device to some extent, since the tongue piece 7 is gradually inclined from the root portion 7a toward the substrate 1 side and the cut and raised hole 8 is considerably large, the cut and raised hole 8 is formed. There is a concern that the local transmission signal may leak through. Further, when the substrate 1 and the partition plate 3 are connected by the solder 6, the flux adheres to the upper end of the partition plate 3 due to surface tension, and an insulating flux film is formed on the surface of the partition plate 3. However, in this case, there is a problem in that the electrical connection between the tongue pieces 7 becomes uncertain simply by simply elastically contacting the end portions of the partition plate 3.

On the other hand, in the shield case of the other high-frequency equipment shown in FIGS. 11 and 12, the opening area of the cut hole 10 of the upper cover 9 is small, and the partition plate 3 is provided in the cut hole 10. Since the flux film adhering to the surface of the partition plate 3 is scraped off when the protrusion 3a is fitted, the partition plate 3
The advantage is that the electrical connection between the upper cover 9 and the upper cover 9 can be secured. However, there is a concern that the projection 3a of the partition plate 3 may project from the surface of the upper cover 9, catch the projection 3a in the production process or the transportation process, or the projection 3a may hit another electronic device. . Further, there is a problem that a die punch for shearing is required to form the cross-shaped cut hole 10, and the die punch is significantly worn.

[0008]

According to the present invention, a downwardly constricted slope is provided inside a cover that covers the opening surface of a frame, and a projecting piece formed at the bottom of the slope engages the end of a partition plate. By so doing, electrical connection between the partition plate and the cover is obtained, and the end portion of the partition plate is positioned in the space inside the slope. By doing this, the end of the partition plate need not be projected outward from the cover surface, and the opening area of the cover is reduced when the end of the partition plate is projected from the protruding piece, so It is possible to reliably suppress the local oscillation signal emitted from the circuit component.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In a shield case for a high-frequency device according to the present invention, a board on which circuit components are mounted, a frame body that houses this board and is divided into a plurality of parts by a partition plate,
And a cover that electrically shields the frame body by covering the opening surface of the frame body. A downward constricted slope is formed on the cover in the direction of the substrate. A projecting piece directed toward the partition plate is formed, and an end portion of the partition plate is projected from the projecting piece to be positioned in a space inside the slope.

Further, when the projecting piece is formed so as to have an upwardly constricted slope that extends upward from the bottom of the downwardly constricted slope, the positioning can be easily performed when the frame is covered with the cover.

If a through hole is formed around the protruding piece, the protruding piece can be formed by punching.
Compared with the conventional example in which the cut holes are formed by shearing, the die punch wear can be significantly reduced.

Further, the slope of the lower constriction is a conical surface which is tapered from the surface of the cover toward the substrate, and the slope of the upper constriction is tapered outward from the bottom of the slope of the lower constriction. With the conical surface, the cover can be easily processed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to the drawings. FIG. 1 is a plan view of a main part of a shield case of a high frequency device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line CC of FIG. Figure, Figure 3
Is a cross-sectional view showing a state before assembly of an upper cover provided in the shield case, FIG. 4 is a plan view showing a modified example of the upper cover provided in the shield case, and FIGS. The same components as those shown in 12 are designated by the same reference numerals.

The shield case of this embodiment shown in FIG.
The difference from the conventional one shown in FIGS. 9 to 12 is that the upper cover 11 has a downwardly constricted slope 12 from the surface thereof toward the substrate 1, and the bottom 1 of the slope 12 is different.
3 has a through hole 14 for receiving the projection 3a projecting from the upper end of the frame 3 and a pair of projecting pieces 15 extending from the bottom 13 of the slope 12 toward the center, and other configurations are basically the same. Is equivalent to

The slope 12 of the lower constriction has an upper cover 11
Is a conical surface that tapers from the surface toward the substrate 1, and the slope 12 and the bottom 13 are concentrically formed. As shown in FIG. 3, the bottom portion 13 is integrally processed in parallel with the surface of the upper cover 11, and the through hole 14 is punched in the central portion of the bottom portion 13 to form the pair of protrusions. Each piece 15 is formed in a tapered shape.

When assembling the shield case of the high-frequency equipment constructed as described above, the upper cover 11 is put on the upper opening of the frame body 2 after the substrate 1, the frame body 2 and the partition plate 3 are integrated in advance. The projection 3a of the partition plate 3 is fitted into the through hole 14 of the upper cover 11, and the tip of the projection piece 15 is engaged with the projection 3a. At this time, the protrusion 3 of the partition plate 3
Since the flux film attached to the surface of a is scraped off by the projecting piece 15, the electrical continuity between the partition plate 3 and the upper cover 11 can be secured. As a result, since the ground is taken, the substrate 1
The local transmission signal emitted from the upper circuit component is the upper cover 1
It is possible to prevent the electronic component from reaching the other electronic component via 1.

In the above-described embodiment, since the projection 3a of the partition plate 3 can be housed inside the surface of the upper cover 11, the projection 3a does not project outward from the surface of the upper cover 11. Further, the projection 3a of the partition plate 3 is provided in the through hole 14.
In the state in which is inserted, the opening area of the upper cover 11 is extremely small, and therefore, the local oscillation signal emitted from the circuit component on the substrate 1 can be surely suppressed. Further, since the protruding piece 15 is formed by punching the through hole 14, it is possible to reduce the wear of the die punch for forming the through hole 14. Further, since the lower constricted slope 12 is formed of a conical surface, the upper cover 11 can be processed more easily than when it is formed of a pyramidal surface or the like.

In the above embodiment, the case where the pair of projecting pieces 15 are formed on the upper cover 11 has been described, but the shape and number of the projecting pieces 15 are not limited to this, and as shown in FIG. When the cross-shaped through hole 18 is punched in the cover 17, the four protrusion pieces 16 are formed on the upper cover 17.
It is also possible to form

FIG. 5 is a plan view of a main part of a shield case of a high frequency device according to another embodiment of the present invention, and FIG. 6 is a DD view of FIG.
FIG. 7 is a cross-sectional view taken along the line, FIG. 7 is a cross-sectional view showing a state before the shield case is assembled, and FIG. 8 is a plan view of an upper cover provided in the shield case, which are shown in FIGS. The same symbols are attached to the same items.

The shield case of this embodiment shown in FIG.
The difference from the embodiment shown in FIGS. 1 to 3 is that the upper cover 19 has a downwardly constricted slope 20 from its surface toward the substrate 1 and a bottom portion 21 of the downwardly constricted slope 20. And a slope 22 that is narrowed upward from above,
The rectangular projecting piece 24 is formed by punching out a U-shaped through hole 23 in the inclined surface 22, and other configurations are basically the same.

The slope 20 of the lower constriction is a conical surface which is tapered from the surface of the upper cover 19 toward the substrate 1, and the slope 22 of the upper constriction is outward from the bottom 21 of the slope 20 of the lower constriction. The conical surface is tapered toward both sides, and both of the slopes 20 and 21 are concentrically formed.

When assembling the shield case of the high-frequency equipment constructed as described above, the substrate 1, the frame 2 and the partition plate 3 are previously integrated as shown in FIG. When the upper opening is covered, the protrusion 3a of the partition plate 3 is guided along the protruding piece 24 having the upper narrowed slope 22 and then the protrusion 3a is inserted into the through hole of the upper cover 19 as shown in FIG. The projection 3 a is inserted into the projection 23, and the projection 3 a is sandwiched between the tip of the projection piece 24 and the edge of the through hole 23. At this time, the flux film adhering to the surface of the projection 3a of the partition plate 3 is scraped off by the projecting piece 24, so that the electrical continuity between the partition plate 3 and the upper cover 19 can be secured. As a result, since the ground is taken, it is possible to suppress the local transmission signal emitted from the circuit component on the substrate 1 from reaching the other electronic components via the upper cover 19.

In the above-configured embodiment, the projection 3a of the partition plate 3 is fitted into the through hole 23 of the upper cover 19 in addition to the effect similar to that of the embodiment shown in FIGS. At this time, since the projection 3a can be guided along the projection piece 24 having the upper narrowed slope 22, the position of the upper cover 19 can be easily aligned, and the assembling property can be improved. Further, as compared with the case where the protruding piece 24 is simply formed in a flat shape, since the protruding piece 24 has the inclined surface 22 formed by the conical surface of the upper constriction, the thrust force applied from the protruding portion 3a of the partition plate 3 In contrast, the strength of the protruding piece 24 can be improved.

[0024]

The present invention is embodied in the form described above, and has the following effects.

A downwardly constricted sloping surface is provided inside the cover that covers the opening surface of the frame body, and a projecting piece formed at the bottom of the sloping surface is engaged with the end of the partitioning plate to cover the partitioning plate and the cover. When the end portion of the partition plate is positioned in the space inside the slope while obtaining an electrical connection with the end portion of the partition plate, the end portion of the partition plate does not have to project outward from the cover surface, and the partition plate Since the opening area of the cover is reduced in a state where the end of the cover is projected from the projecting piece, it is possible to reliably suppress the local transmission signal generated from the circuit component on the board.

Further, when the projecting piece is formed so as to have an upwardly constricted slope that extends upward from the bottom of the downwardly constricted slope, the positioning can be easily performed when the frame is covered with the cover.

If a through hole is formed around the projecting piece, the projecting piece can be formed by punching.
Compared with the conventional example in which the cut holes are formed by shearing, the die punch wear can be significantly reduced.

Further, the slope of the lower constriction is a conical surface which is tapered from the surface of the cover toward the substrate, and the slope of the upper constriction is tapered outward from the bottom of the slope of the lower constriction. With the conical surface, the cover can be easily processed.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a shield case of a high-frequency device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line CC of FIG.

FIG. 3 is a cross-sectional view showing a state before assembly of an upper cover included in the shield case.

FIG. 4 is a plan view showing a modified example of an upper cover included in the shield case.

FIG. 5 is a plan view of a main part of a shield case of a high-frequency device according to another embodiment of the present invention.

FIG. 6 is a sectional view taken along line DD of FIG. 5;

FIG. 7 is a cross-sectional view showing a state before assembly of the shield case.

FIG. 8 is a plan view of an upper cover included in the shield case.

FIG. 9 is a plan view showing a main part of a shield case of a high-frequency device according to a conventional example.

10 is a cross-sectional view taken along the line AA of FIG.

FIG. 11 is a plan view showing a main part of a shield case of a high-frequency device according to another conventional example.

12 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 1 Substrate 2 Frame 3 Partition Plate 3a Projection 5 Lower Cover 6 Solder 11 Upper Cover 12 Lowered Slope 13 Bottom 14 Through Hole 15 Projecting Piece 16 Projecting Piece 17 Upper Cover 18 Through Hole 19 Upper Cover 20 Lowering Slope 21 Bottom 22 Upper constricted slope 23 Through hole 24 Projecting piece

Claims (4)

[Claims] 1. A board on which a circuit component is mounted, a frame that houses the board and is divided into a plurality of parts by a partition plate, and a cover that covers the opening surface of the frame to electrically shield the frame. And a downwardly constricted slope is formed on the cover from the surface toward the substrate, and a projecting piece toward the center is formed at the bottom of the slope, and the end of the partition plate is A shield case for a high-frequency device, characterized in that a protruding piece is protruded from and positioned in a space inside the slope. 2. The shield case for a high-frequency device according to claim 1, wherein the protruding piece has an upper constricted slope extending upward from a bottom portion of the lower constricted slope. 3. The shield case for a high-frequency device according to claim 1, wherein a through hole is formed around the projecting piece. 4. The inclined surface of the lower constriction according to claim 2 or 3, wherein the inclined surface of the lower constriction is a conical surface that tapers from the surface of the cover toward the substrate, and the inclined surface of the upper constriction is the lower constriction. A shield case for high-frequency equipment, characterized in that it consists of a conical surface that tapers outward from the bottom of the marino slope.