JP3453029B2 - Ground terminal structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground terminal structure for electronic equipment having an electronic circuit.

[0002]

2. Description of the Related Art In a conventional electronic device or the like, for example, as a ground terminal structure having a high frequency circuit, as shown in FIG. 5, a shield case 11 is made of a metal plate and has an opening 12 for opening up and down. And four side plates 13 on each side.
Boxes 14, 15 and 16 are formed. The end portions of the side plates 13, 14, 15, 16 are fixed by caulking or the like. The upper and lower sides of the side plate 13 are end faces 13a.
A rectangular shape sandwiched between 13b, two cutouts 13c, 13d are formed on the end face 13a side, a ground terminal 17 is formed in the cutout 13c, and a side plate 15 is formed.
A claw portion 13e is formed by bending toward the inside of the shield case 11 on the flat surface close to it.

The one notch portion 13c is
As shown in FIG. 6, one end has a stepped step 13f.
, The tongue-shaped ground terminal 17 is provided on the other end of the side plate 13.
Is formed by extending in a direction parallel to the end surfaces 13a and 13b and cutting out a hatched portion by press working or the like. Then, the tongue-shaped ground terminal 17 with its periphery cut out
Is cut and raised from a bending line B orthogonal to the end surface 13a of the side plate 13, and the flat surface portion 17a is formed toward the outside of the shield case 11 in a direction orthogonal to the end surface 13a. Further, stepped step portions 13g are formed on both sides of the cutout portion 13d at the same height as the stepped portion 13f of the cutout portion 13c. A side plate 14 is formed on the opposite side of the side plate 13 with the opening 12 interposed therebetween, and a plurality of claw portions 14a are formed on the flat surface of the side plate 14 to form a claw portion 13e of the side plate 13. It is formed by bending toward the inside of the shield case 11 at the same height as. The opening 1 is provided on one side of the side plates 13 and 14.
2 has a side plate 15 provided with a grounding portion 15a outside, and the other side has a side plate 1 provided with a grounding portion 16a outside the opening 12.
6 is attached to form a box shape, and a shield case 1
1 is configured.

However, the ground terminal 17 is connected to the side plate 13.
Since one cutout portion 13c is cut and raised from the bending line B orthogonal to the end surface 13a, and the flat portion 17a is formed toward the outside of the shield case 11 in the direction orthogonal to the end surface 13a, 2 in the notch 13c
Even if the individual ground terminals 17 are provided, as shown in FIG. 7, the distance between the two ground terminals 17b and 17c is made smaller than the dimension C in which the lengths of the two ground terminals 17b and 17c are combined. It is not possible. Therefore, the two ground terminals 17a and 17b could not be closer than the dimension C. In addition, the ground terminal 17 could not be provided near the center of the cutout 13c.

As an electronic device using the shield case 11 having such a structure, a high frequency device having a printed circuit board 18 as shown in FIG. 8 will be described as an example. A circuit on which high-frequency components and the like are mounted is configured on the printed circuit board 18 of FIG. 8, a part of the circuit is mounted on the stepped steps 13f and 13g of the side plate 13, and the other part is a nail. Part 1
3e and the plurality of claw portions 14a on the side plate 14 side are inserted with through holes (not shown) of the printed circuit board 18, and the conductive patterns formed around the through holes and the respective claw portions 13e and 14a are formed. Shield case 1 by soldering, etc.
1 is attached to the opening 12. Various circuits (not shown) are formed on the printed circuit board 18, and a plurality of circuit terminals 19a, 19b, 19c, ... For taking out the circuits to the outside of the shield case 11 are projected to the outside of the shield case 11. The high-frequency equipment is configured by being provided. The high-frequency device having the above-described configuration is mounted on a mother board 20 of a set device such as a VTR or TV (not shown) as shown in the schematic view of FIG. 9 and attached by soldering or the like.

[0006] In such a high-frequency device, for example, if an unnecessary signal such as noise or pulse is included in a power supply circuit, an AGC circuit or the like, the performance of the set device such as the VTR or the TV deteriorates. As a countermeasure against this, as shown in the schematic view of FIG. 9, an earth pattern 20a that is electrically connected to the earth terminal 17 on the motherboard 20 on the set device side.
A capacitor (bypass capacitor) 21 is connected by soldering or the like between the power supply circuit pattern 20b and the circuit terminal 19a of the power supply circuit of the high-frequency device to connect the unnecessary signal to the ground. Also in the AGC circuit, AGC that is electrically connected to the circuit terminal 19b if example embodiment
The capacitor 20 is also connected between the circuit pattern 20c and the ground pattern 20a to drop the unnecessary signal to the ground to prevent the performance of the set device from deteriorating.

In the conventional ground terminal 17 structure as described above, the tongue-shaped ground terminal 17 extending in the direction parallel to the end face 13a of the side plate 13 is cut and raised to form the ground terminal 17 and the high frequency wave. The positional relationship with the plurality of circuit terminals 19 attached to the printed circuit board 18 of the device is shown in FIG.
, The ground terminal 17 and the circuit terminal 19a are adjacent to each other and located at the shortest distance.
1 through the power circuit pattern 20b, the circuit terminal
It was possible to connect to the earth pattern 20a at a position at the shortest distance from 19a. Therefore, power supply circuit pattern 2
0b can be connected to the earth pattern 20a with a sufficiently low earth impedance, and even if the power circuit includes an unnecessary signal, the unnecessary signal can be grounded via the earth pattern 20a. However, since the circuit terminal 19b of the AGC circuit is located away from the ground terminal 17 with the circuit terminal 19a of the power supply circuit interposed therebetween, as shown in FIG. 9, the AGC circuit pattern 20c is replaced with the power supply circuit pattern 20b. The capacitor 21 is formed in a detour in an L shape so as not to come into contact with, and the capacitor 21 is connected to the ground pattern 20a via the AGC circuit pattern 20c at a remote position away from the circuit terminal 19b of the AGC circuit. Therefore, the distance of the AGC circuit pattern 20c from the circuit terminal 19b of the AGC circuit to the position where the capacitor 20 is connected becomes long, and an inductance component is generated in the long AGC circuit pattern 20c, so that the AG
Even if the C circuit contains an unnecessary signal or the like, the unnecessary signal cannot be sufficiently grounded through the ground pattern 20a, and the sufficient electrical performance of the AGC circuit cannot be obtained.

[0008]

In the conventional grounding terminal structure, the tongue-shaped grounding terminal 17 extending in the direction parallel to the end faces 13a and 13b of the side plate 13 was cut and raised outside the opening 12. Therefore, the ground terminal 17 is located at the shortest distance adjacent to the circuit terminal 19a of the printed circuit board 18, but far from the circuit terminal 19b adjacent to the circuit terminal 19a. Therefore, when the conventional ground terminal structure is used for a high-frequency device or the like and mounted on a set device or the like, for example, an AGC circuit pattern 20c that is conductive with the circuit terminal 19b of the AGC circuit and a ground pattern 20a that is conductive with the ground terminal 17 are provided. As shown in FIG. 9, since the capacitor 21 was connected at a distant position away from the circuit terminal 19b of the AGC circuit via the AGC circuit pattern 20c detoured in an L shape, the circuit terminal of the AGC circuit was An inductance component is generated in the AGC circuit pattern 20c from 19b to the position where the capacitor 21 is connected, and
Even if the circuit includes an unnecessary signal, the unnecessary signal cannot be sufficiently grounded via the ground pattern 20a, and the AGC circuit cannot have sufficient electrical performance, so that the VTR, TV, etc. Could not improve the performance of the set equipment. Further, in the conventional ground terminal structure of the shield case, the ground terminal 17 cannot be provided in the vicinity of the central portion of the cutout portion 13c of the side plate 13, and can only be provided in the vicinity of the end portion of the cutout portion 13c. Therefore, the power supply circuit or the AGC circuit must always be arranged near the end of the cutout portion 13c, so that the range of circuit design on the high frequency device and the set device side is limited, There was little freedom in design.

[0009]

As a first means for solving the above problems, a shield case formed of a side plate made of a metal plate , a cutout portion provided in the side plate, and the cutout portion are provided. and a ground terminal provided on the sea
Printed circuit board inside the case and the notch
Protruding outside of the shield case while being positioned
A plurality of circuit terminals provided on the printed circuit board, the shield case being located in the cutout portion.
State that the tip has a part of the end of the side plate
Cut and raised from a fold line parallel to the end face of the side plate.
The state of being rubbed and connected to the flat surface of the side plate
A ground terminal is provided, and the ground terminal is the circuit end.
Projected outside the shield case while facing the child
It was made into the composition. In addition, the second for solving the above problems
As means, said ground terminal, and a configuration of forming two or more the notch of the side plate.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a ground terminal structure of the present invention will be described below with reference to FIGS. In addition,
The same parts as those described in the related art will be described with the same numbers. The ground terminal structure of the present invention is
For example, as shown in FIG. 1, a shield case 1 made of a metal plate has openings 2 that open at the top and bottom, and has a four-sided opening.
Having one side plate 3, 4, 5, 6 and the side plate 3, 4, 5, 6
Has a box shape with its corners fixed by caulking or the like. And, the side plate 3 has upper and lower end faces 3a, 3
In the rectangular shape sandwiched by b, cutout portions 3c and 3d are formed on the end face 3a side, and as shown in FIG. 2, the cutout portion 3c has stepped step portions 3f at both end portions. Form,
A tongue-shaped ground terminal 7 is provided between the step portions 3f, 3f on both sides.
a. 7b, with its tip having a part of the end face 3a in the longitudinal direction of the side plate 3 and extending in the direction orthogonal to the end face 3a, cut out the hatched portion by press working or the like, Bending line A parallel to the end face 3a in the longitudinal direction
It is formed by cutting and raising from the outside of the shield case 1. Therefore, a plurality of the tongue-shaped ground terminals 7 can be formed in the cutout portion 3c, the intervals thereof can be arbitrarily formed, and the tongue-shaped ground terminals 7 can be freely formed at respective required positions.

Further, the other notch portion 3 of the side plate 3
In step d, stepped steps 3g are formed at the ends on both sides at the same height as the steps 3f of the one notch 3c. A claw portion 3e is formed near the side plate 5 on the side of the side plate 3. Side plates 4 are formed on opposite sides of the side plate 3 with the opening 2 sandwiched therebetween, and a plurality of claws 4a are formed on the flat surface of the side plate 4, and the opening 2 of the shield case 1 is formed.
3e of the side plate 3 is bent toward the inside of the
It is formed with the same height as. Also, the side plates 3 and 4
A side plate 5 having a ground portion 5a outside the opening 2 is provided on one side, and a side plate 6 is provided on the other side outside the opening 2 and the ground portion 5a of the side plate 5 is provided outside the opening 2. The box-shaped shield case 1 is formed by being attached with the directional earth portion 6a, and the earth terminal structure of the present invention is provided in the shield case 1.

An example in which the shield case 1 having the earth terminal structure having the above-mentioned structure is used will be described by taking a high frequency device having a printed circuit board 18 as shown in FIG. 3 as an example. The printed circuit board 18 shown in FIG. 3 is configured with a circuit on which high frequency components and the like are mounted. A part of the printed circuit board 18 is provided with the cutout portion 3 of the side plate 3.
It is placed on the stepped steps 3f and 3g of c and 3d, the other part is on the claw portion 3e, the side plate 4 side is on the plurality of claw portions 4a, and through holes (not shown) of the printed circuit board 18 are provided. The conductive pattern formed around the through hole and each of the claw portions 3e and 4a are inserted and attached to the opening 2 of the shield case 1 by soldering or the like. Then, various circuits (not shown) are formed on the printed circuit board 18, the circuits are taken out of the shield case 1, and the circuit of the mother board on the set side of the VTR, TV, etc.
A plurality of circuit terminals 19 for connecting to the pattern are attached to the outside of the shield case 1 so as to project in the same direction as the ground portion 5a of the side plate 5 or the ground portion 6a of the side plate 6 to form a high-frequency device. There is. The high-frequency device having the above-described configuration is mounted on a motherboard 10 of a set device such as a VTR or TV (not shown) as shown in the schematic view of FIG. 4 and attached by soldering or the like.

As shown in the schematic view of FIG. 4, the mother board 10 on the side of the set equipment, on which the high-frequency equipment using the earth terminal structure of the present invention is mounted, has a ground terminal 7 as shown in FIG.
Since the plane a and the plane of the circuit terminal 19a of the power supply circuit face each other at a short distance, the capacitor 21
Can be connected to the ground pattern 10a via the power supply circuit pattern 10b at the shortest distance from the circuit terminal 19a. Therefore, since the power supply circuit pattern 10b can be grounded with a sufficiently low ground impedance, even if the power supply circuit contains an unnecessary signal, the unnecessary signal can be dropped to the ground via the ground pattern 10a. It is possible to improve the performance of a set device such as a TV or a TV. Also, the circuit terminal 19b of the AGC circuit
Since the plane of the capacitor 21 is also located parallel to and facing the plane of the ground terminal 7b at a short distance,
It can be connected to the earth pattern 10a via the circuit pattern 10c at the shortest distance from the circuit terminal 19b of the C circuit. Therefore, the circuit pattern 10c of the AGC circuit can be grounded with a sufficiently low ground impedance, so that even if the AGC circuit includes an unnecessary signal, the unnecessary signal can be grounded via the ground pattern 10a. , The performance of set devices such as VTRs and TVs can be improved.

Further, the earth terminal structure of the present invention is not limited to the two earth terminals 7a and 7b as shown in FIG. 4, but is opposed to the circuit terminal 19c adjacent to the circuit terminal 19a of the power supply circuit, for example. Although not shown, a ground terminal having the same structure as that of the ground terminals 7a and 7b can be formed at the position to be formed. Also, the circuit terminal 19b of the AGC circuit
It is also possible to form a grounding terminal of the same structure at a position where the circuit terminal 19d next to the above is opposed. Therefore, even if the circuit terminal 19a of the power supply circuit and the circuit terminal 19b of the AGC circuit are not adjacent to each other for the convenience of design, the ground terminals 7a and 7b should be connected to the circuit terminals 19a, 19b, and 19c.
It can be formed at the position of the shortest distance at any position of 19d. Therefore, since the capacitor 21 can be connected to the position of the shortest distance from the respective circuit terminals through the respective circuit patterns, the capacitor 21 is always connected.
Since the grounding can be performed with a low ground impedance by the effect of, the performance of set equipment such as a VTR and a TV can be improved. Also, the circuit terminal 19a of the power supply circuit,
Even if the circuit terminals 19b of the AGC circuit and the circuit terminals 19b of the AGC circuit are arranged at positions distant from each other, in the case of the ground terminal structure of the present invention, the circuit terminals 19a and 19b arranged at the positions distant from each other, respectively, Since the ground terminal 7 is provided, the degree of freedom in circuit design is improved.

[0015]

As described above, in the grounding terminal structure of the present invention, a part of the shield case is cut and raised in parallel with the end face of the side plate, and the grounding terminal protruding to the outside of the shield case is provided. Since the ground terminal can be formed at the shortest distance from the respective circuit terminals of the power supply circuit and the AGC circuit, the circuit pattern of the capacitor can be formed at the shortest distance from the respective circuit terminals. Since it can be connected to the ground pattern via
Even if the power supply circuit or the AGC circuit contains an unnecessary signal or the like, the unnecessary signal or the like can be surely grounded by the capacitor, so that the performance of a set device such as a VTR or a TV can be improved. .

Further, since two or more of the ground terminals are formed in the cutout portion of the side plate, the circuit terminal of the power supply circuit and the circuit terminal of the AGC circuit are not adjacent to each other but separated for the convenience of design. Even if they are arranged, at the position of the shortest distance between the respective circuit terminals arranged apart from each other,
Since more than one ground terminal can be provided, the power supply circuit or the AGC circuit can be provided at a convenient position, so that the degree of freedom in circuit design is improved and the VT
It is possible to improve the performance of set devices such as R and TV.

Since the planes of the plurality of circuit terminals and the plane of the ground terminal are opposed to each other, the circuit terminals of the power supply circuit and the circuit terminals of the AGC circuit are equidistant from each other.
Moreover, since the ground terminal can be formed at the position of the shortest distance, the capacitor can be connected to the ground pattern at the position of the shortest distance from each of the circuit terminals, so that even if the power supply circuit or the AGC circuit includes an unnecessary signal or the like. Since the unnecessary signal can be reliably grounded by the capacitor, the performance of set equipment such as a VTR or a TV can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a shield case using the ground terminal structure of the present invention.

FIG. 2 is a schematic view of a side plate for explaining the ground terminal structure of the present invention.

FIG. 3 is a schematic side view of a high-frequency device using the ground terminal structure of the present invention.

FIG. 4 is an explanatory diagram in which a high-frequency device using the ground terminal structure of the present invention is attached to a motherboard on the set device side.

FIG. 5 is a perspective view of a shield case using a conventional ground terminal structure.

FIG. 6 is a schematic view of a side plate for explaining a conventional ground terminal structure.

FIG. 7 is a schematic view of a side plate for explaining a conventional ground terminal structure.

FIG. 8 is a schematic side view of a high-frequency device using a conventional ground terminal structure.

FIG. 9 shows a high-frequency device using a conventional ground terminal structure,
Explanatory drawing attached to the motherboard on the set device side.

[Explanation of symbols]

1 shield case 2 openings 3-6 side plate 7 ground terminal 10 motherboard 11 shield case 12 openings 13 to 16 side plates 17 Ground terminal 18 Printed circuit board 19 circuit terminals 20 motherboard 21 capacitor

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Claims (2)

(57) [Claims] 1. A shield case formed of a side plate made of a metal plate , a cutout portion provided in the side plate, a ground terminal provided in the cutout portion, and the shield case.
The printed circuit board inside the slot and the cutout.
When it is placed, it protrudes to the outside of the shield case,
And a plurality of circuit terminals provided on the printed circuit board, the switching
A part of the shield case located in the recess is
With the tip of the side plate having a part of the end of the side plate,
Cut and raised from a fold line parallel to the end face of the plate,
The ground terminal connected to the flat surface of the side plate
Is provided, and the ground terminal faces the circuit terminal.
The ground terminal structure, which is projected outside the shield case in a closed state . Wherein said ground terminal, the ground terminal structure according to claim 1, wherein the forming at least two said cut-out portion of the side plate.