JP3751515B2 - Circuit board shield structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit board shield structure used in a high-frequency unit or the like built in a high-frequency device such as a tuner.
[0002]
[Prior art]
In the shield structure of a circuit board such as a high-frequency unit built in a high-frequency device such as a tuner, the role of the shield case attached to the circuit board on which the electronic component is mounted is a circuit constituted by the electronic component on the circuit board. In addition to preventing the influence of an external electric field, the mechanical strength of the circuit board is strengthened and the influence of mechanical external forces such as vibrations is prevented from reaching the circuit composed of electronic components on the circuit board. And so on.
[0003]
As the attachment of the shield case to such a circuit board, attachment by dipping has become the mainstream. In order to attach the shield case and the circuit board by dipping, it is necessary to fix the circuit board to the shield case. For example, when inserting the protrusion of the shield case into the insertion part of the circuit board, It is necessary to prevent the circuit board from falling off after insertion.
[0004]
Here, with reference to FIGS. 6 to 10, description will be given of how to prevent insertion and removal of a circuit board in a conventional shield structure of a circuit board.
[0005]
As shown in FIGS. 6 and 7, the shield case b is formed with a tongue piece c between a pair of a and a formed with a slight gap. Then, when attaching the shield case b to the circuit board d, as shown in FIG. 8, the circuit board d is fitted inside the shield case b, and the tongue c is placed inside the case using a processing jig or the like. Defeat to prevent falling out.
[0006]
This drop-off preventing tongue piece c corresponds to K in FIG. In addition, as a shape of the drop-off preventing tongue piece, there is a shape as shown in J of FIG. And as a tongue piece for insertion stop of a circuit board, there exists a thing of the shape like H and I of FIG.
[0007]
That is, as shown in FIG. 10, the insertion-preventing tongues H and I are designed to prevent insertion by stopping a part of the side wall of the shield case b toward the inside of the shield case b. , K are formed in the vicinity of the lower edge of the side wall portion of the shield case b, and fall to the inside of the shield case b to prevent it from falling off.
[0008]
Moreover, as a modification of what is shown in FIG. 6, as shown in FIG. 10, a part of the side wall of the shield case b is cut up and bent into a substantially L shape to form an attachment piece e. In some cases, an insertion hole g corresponding to the protrusion f is formed in the circuit board d.
[0009]
[Problems to be solved by the invention]
However, the above prior art has the following problems.
[0010]
Each of the tongue piece c shown in FIGS. 6 to 8, the tongue pieces H, I, J, and K shown in FIG. 9 and the attachment piece e shown in FIG. 10 is formed on a part of the side wall portion of the shield case b. Therefore, in the portion where the tongue pieces c, H, I, J, K and the attachment piece e are tilted inside the shield case b, a hole is formed in the side wall portion of the shield case b. Then, according to the quantity which forms such tongue pieces c, H, I, J, K, and the attachment piece e, the mechanical strength of the shield case b will fall.
[0011]
Further, when bending the tongue pieces c, H, I, J, K and the mounting pieces e inside the shield case b, the shape of the shield case b may be distorted. When the number of c, H, I, J, K and the mounting piece e increases, such a shape distortion is likely to occur.
[0012]
However, the circuit board insertion stop and drop-off prevention are indispensable when dipping, and the current state of the art is that the above-described prior art is employed even at the expense of the above-described problems.
[0013]
The present invention has been made in order to solve the above-described problems, and with a simple configuration, the mechanical strength of the shield case is prevented from being lowered and the distortion of the shape is prevented. It is an object of the present invention to provide a shield structure for a circuit board that can be stopped.
[0014]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a circuit board shield structure in which a frame-shaped shield case is attached to a circuit board, and the side wall portion of the shield case is opposite to the side to which the circuit board is connected. An extension piece extending in the L-shape to the side to which the circuit board is connected is formed at the edge of the extension piece , a first projection is formed at the tip of the extension piece , and the first projection is The circuit board includes a key-shaped stopper for preventing insertion and falling off protruding sideways, and the circuit board has a first insertion hole formed at a position corresponding to the first protrusion, and the first And the extension piece is formed at a corner portion of the shield case, and a side projection is provided at a side edge of the extension piece. And the side protrusions facing each other On the other side wall portion which is provided perpendicularly to the side wall of the case, it is characterized in that the insertion hole for locking by fitting the lateral projection portion is provided.
[0015]
In the present invention, as described above, since the first protrusion of the extension piece of the shield case side wall is inserted into the first insertion hole of the circuit board and attached, the stopper of the first protrusion of the extension piece is attached. The first insertion hole of the circuit board is locked between the portion and the edge of the distal end portion of the extension piece around it, and the circuit board can be inserted and stopped. Here, since the extension piece can be formed by utilizing a portion that has been discarded at the time of forming the shield case, it can be realized with a simple configuration without incurring an increase in cost, and the tongue piece and the attachment piece as in the prior art described above. As described above, since a part of the side wall portion of the shield case is not formed by processing, there is no possibility that the mechanical strength of the shield case is lowered or the shape of the shield case is distorted.
[0016]
Therefore, according to the present invention, it is possible to perform dipping by preventing the circuit board from being inserted and coming off, and with a simple configuration, the mechanical strength of the shield case can be enhanced compared to that of the above prior art, Distortion of the shape of the shield case can be prevented.
[0017]
Furthermore, the present invention is characterized in that, in the shield structure of the circuit board, the extension piece is formed at a corner portion of the shield case.
[0018]
According to the present invention, since the extension piece is formed at the corner portion of the shield case, it is possible to satisfactorily prevent the circuit board from being inserted and removed by, for example, forming extension pieces at four corner portions. it can.
[0019]
According to the present invention, in the shield structure of the circuit board, the first protrusion is formed at an intermediate position of a tip portion of the extension piece.
[0020]
According to the present invention, since the first protrusion is formed at an intermediate position of the distal end portion of the extension piece, the first protrusion portion of the first protrusion portion is compared with that formed at the end position of the extension piece distal end portion. The first insertion holes of the circuit board can be locked using the edges of the distal end portions of the extension pieces on both sides, and the circuit board can be more reliably prevented from being inserted and dropped off.
[0021]
In the shield structure of the circuit board described above, at least one edge of the circuit board extends outward from the shield case, and the circuit board extends to the outside of the shield case. A second protrusion is formed on the side wall of the shield case, a second insertion hole is formed in the circuit board at a position corresponding to the second protrusion, and the second protrusion is the second protrusion. It is inserted into the insertion hole and is attached.
[0022]
In the present invention, as described above, in the type in which at least one edge of the circuit board extends outward from the shield case, the second protrusion is provided on the side wall of the shield case. Since the portion is inserted into and attached to the second insertion hole of the circuit board, the circuit board can be more stably fixed to the shield case, and the circuit board can be more reliably prevented from being inserted and dropped off.
[0023]
According to the present invention, in the shield structure for the circuit board, a land is formed at least at a part of a contact portion between the shield case and the circuit board.
[0024]
According to the present invention, since the land is formed at least at a part of the contact portion between the shield case and the circuit board, dipping or the like can be easily performed by solder or the like. The fixing strength between the case and the circuit board can be strengthened.
[0025]
In the shield structure for a circuit board according to the present invention, the shield case is provided with a shield plate provided on a side wall portion.
[0026]
According to the present invention, since the shield case is provided on the side wall portion of the shield case, the mechanical strength of the intermediate portion of the shield case can be reinforced, and the circuit blocks on the circuit board can be shielded. As a result, the shielding effect can be improved.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0028]
FIG. 1 is an exploded perspective view showing a shield structure of a circuit board according to the present embodiment, FIG. 2 is a development view of a shield case used in the present embodiment, and FIG. 3 is the vicinity of an extension piece of the shield case shown in FIG. 4 is a partially enlarged view of the vicinity of the shield plate shown in FIG. 2, and FIG. 5 is a plan view of the circuit board used in the present embodiment.
[0029]
1 to 5, 1 is a shield case, 2 is a circuit board, A 1, A 2, B, and C are side walls of the shield case 1, and C 6 and C 7 are protrusions of the side wall C (second protrusions). ), D, D1 are shield plates of the shield case 1, E2, E11, E12, E13, E14 are extension pieces, E1 is a projection (first projection) of the extension piece, and E4 is on the side of the projection E1. The formed protruding stoppers B1 ′, C6 ′, C7 ′, D31 ′, D32 ′, D33 ′, E11 ′, E12 ′, E13 ′, and E14 ′ are insertion holes (C6 ′, C7) of the circuit board 2. ′ Is a second insertion hole, and E11 ′, E12 ′, E13 ′, and E14 ′ are first insertion holes).
[0030]
First, the shield case 1 in this embodiment is demonstrated.
[0031]
As shown in the developed view of FIG. 2, the shield case 1 is made of a single metal plate and is manufactured by punching using a mold or the like. Then, the shield case 1 shown in the developed view of FIG. 2 is bent, and as shown in FIG. 1, a pair of long side wall portions A1 having a substantially rectangular shape in plan view and facing each other. , C and the short side wall portions A2 and B facing each other in a direction perpendicular to them, the plan view is a substantially rectangular frame shape.
[0032]
As shown in FIG. 1, the shield case 1 is provided with a shield plate D installed on the side wall portions A1 and C.
[0033]
Further, as shown in the developed view of FIG. 2, the side wall portions A1, A2, B, and C are connected to each other by the rectangular connection portion at the corner portion between the side walls adjacent to each other, and the shield plate D is also connected to the side wall portions A1, A1. It is connected to C by a similar rectangular connection.
[0034]
In the shield case 1 of the present embodiment, the side walls A1, A2, B, and C are laterally formed by bending from the developed view of FIG. 2 into a frame shape as shown in FIG. The protrusions F are inserted into the insertion holes F ′ and are fitted together so that the side wall portions adjacent to each other are locked and coupled. At this time, as shown in FIG. 4, the shield plate D (D1) is also provided with a side projection D2, which is inserted into the insertion hole D2 'in the side wall and fitted to the side wall. I try to stop.
[0035]
Furthermore, in the shield case 1 of the present embodiment, extension pieces E11, E12, E13 extending to the side to which the circuit board 2 is connected in a substantially L shape at the edge opposite to the side to which the circuit board 2 is connected. , E14 are formed by being connected to a rectangular connecting portion at the corner portion.
[0036]
Each of the extension pieces E11, E12, E13, E14 is formed with a first protrusion having a stopper at the tip.
[0037]
As an example of the protruding portion of the extension piece, E11 will be described with reference to FIG. Here, the extension piece E11 is taken as an example, but the following description is the same for the other extension pieces E12, E13, E14.
[0038]
As shown in FIG. 3, the extension piece E2 has a protrusion E1 at the tip, and the protrusion E1 has a stopper E4 that protrudes to the side of the protrusion E1. The protrusion E1 has a key shape. This stopper portion E4 is subjected to R processing at the corners on both sides, and when assembled with a circuit board 2 described later (when inserting insertion holes E11 ′, E12 ′, E13 ′, E14 ′ of the circuit board 2), Insertion can be made smooth. The distance from the tip of the extension piece E2 to the stopper E4 in the protrusion E1 is set to a dimension (size) substantially equal to the plate thickness of the circuit board 2 so that the circuit board 2 can be stably fixed. it can.
[0039]
Further, in FIG. 3A, the protrusion E1 is formed at the end position of the tip of the extension piece E2. As shown in FIG. 3B, the protrusion E1 is extended to the extension piece. It is preferable to form it at a substantially middle position of the tip end portion of E2. That is, by using the edges of the ends of the extension pieces E2 on both sides of the protrusion E1, the insertion holes E11 ′, E12 ′, E13 ′, E14 ′ of the circuit board 2 are locked to stabilize the circuit board 2. This is because the circuit board 2 can be fixed and the insertion and removal of the circuit board 2 can be better prevented.
[0040]
2 is bent to form a frame shape as shown in FIG. 1, a side projection E6 is provided on the extension piece E2 as shown in FIG. It is inserted into the insertion hole E6 ′ of the part and fitted to be engaged with the side wall part.
[0041]
The extension pieces E11, E12, E13, and E14 as described above do not necessarily have to be formed at the corner portion, but are arranged at four locations at each corner portion as in the shield case 1 of the present embodiment. Is preferred.
[0042]
This is because when the circuit board 2 is attached to the shield case 1, it is possible to prevent the circuit board 2 from being unstablely fixed such as the circuit board 2 being pushed and tilted during the work. is there. Furthermore, if the extension pieces 11, E12, E13, and E14 are arranged at the corner portion of the shield case 1, as shown in FIG. 3, the side projection portion E6 of the extension piece E2 and the insertion hole E6 ′ in the side wall portion are formed. By the locking, the extension piece is coupled to the two side wall portions and is more firmly fixed, and the circuit board 2 can be stably fixed by the shield case 1.
[0043]
The extension pieces E11, E12, E13, and E14 of the present embodiment are made of the same metal plate material as the side wall portions A1, A2, B, and C of the shield case 1, and thus are made of metal that constitutes the shield case. It can be realized with a simple configuration by effectively utilizing the previously discarded part of the plate material.
[0044]
Next, each side wall part of the shield case 1 of the present embodiment will be described. In the shield case 1 of the present embodiment, the side wall portions A1 and A2 have the tongue pieces c shown in FIGS. 6 to 8 and the tongue pieces H, I, J, and K shown in FIG. The attachment piece e shown in FIG. 10 can be abolished.
[0045]
And since the side wall part B is a part to which an input / output terminal is attached and connected, strong intensity | strength is required. Therefore, in the present embodiment, the protrusion B1 is formed in a slight space in the substantially middle portion of the side wall B, and the protrusion B1 is inserted into the insertion hole B1 ′ of the circuit board 2 and locked to reinforce it. It is configured.
[0046]
In addition, this projection part B1 is good also as a projection part provided with the stover part like projection part E1 of extension piece E2 shown in FIG. 3, and can fix circuit board 2 more firmly and stably then. .
[0047]
In addition, as shown in FIG. 1, this embodiment is a type in which the edge of the circuit board 2 extends outward from the shield case 1 side wall portion C in the direction of the shield case 1 side wall portion C in a plan view. Is.
[0048]
In this configuration, a pin header or the like is arranged on the side wall C side, and a signal, a power source, or the like is output or input from the outside through the pin header or the like to the inner part of the shield case 1 of the circuit board 2. This is because. Therefore, as shown in FIG. 2, C1, C2, and C3 are formed in the side wall C as passages for such signals and power sources. In the present embodiment, the size of the passage portions C1, C2, and C3 is minimized to prevent the mechanical strength from being lowered at the side wall portion C.
[0049]
In the case of the type of this embodiment, it is preferable to fix the shield case 1 and the circuit board 2 also on the side wall portion C. Therefore, in the present embodiment, portions C4 and C5 having the same height as the side wall portions A1, A2 and B are formed on the side of the side wall portion C of the shield case 1, and the circuit board 2 is provided at positions corresponding thereto. Cuts C4 ′ and C5 ′ are formed, and the side parts C4 and C5 of the side wall part C are fitted into the cuts C4 ′ and C5 ′ of the circuit board 2. Furthermore, projections C6 and C7 are formed in portions other than the passage portions C1, C2 and C3 at the lower end edge of the side wall C, and insertion holes C6 ′ and C7 ′ are formed in the circuit board 2 at positions corresponding thereto, By inserting the projections C6 and C7 into the insertion holes C6 ′ and C7 ′ and locking them, the circuit board 2 is fixed also at the side wall C.
[0050]
Note that the projections C6 and C7 of the side wall C may be projections having a stubber portion, like the projection E1 of the extension piece E2 shown in FIG. The circuit board 2 can be fixed.
[0051]
Next, the shield plate D (D1) of this embodiment will be described with reference to FIG.
[0052]
The shield plate D (D1) of the present embodiment is installed between the shield case 1 side walls A1 and C, can reinforce the mechanical strength of the shield case 1, and is further extended with the extension pieces E11, E12, E13, E14. Similarly, it is made of the same metal plate material as the side wall portions A1, A2, B, and C of the shield case 1, and thus effectively utilizes the conventionally discarded portion of the metal plate material constituting the shield case. It can be realized with a simple configuration.
[0053]
Then, in the shield plate D (D1) of the present embodiment, as shown in FIG. 4, a side protrusion D2 is provided, and is inserted into the insertion hole D2 ′ in the side wall and fitted to the side wall. By engaging, the mechanical strength of the shield case 1 is further strengthened.
[0054]
Further, as shown in FIG. 4, protrusions D31, D32, D33 are formed on the lower edge of the shield plate D1 (D), and insertion holes D31 ′, D32 ′, D33 are formed at positions corresponding to the protrusions D31, D32, D33. ′, And the protrusions D31, D32, D33 are inserted into the insertion holes D31 ′, D32 ′, D33 ′ and locked so that the circuit board 2 is fixed also on the shield plate D1 (D). ing.
[0055]
Note that the projections D31, D32, and D33 of the shield plate D1 (D) may be projections having a stubber portion, similarly to the projection E1 of the extension piece E2 shown in FIG. The circuit board 2 can be fixed firmly and stably.
[0056]
Next, the circuit board 2 of the present embodiment will be described with reference to FIG.
[0057]
As shown in FIG. 5, the circuit board 2 includes projections of the extension pieces E11, E12, E13, and E14 of the shield case 1, the projection B1 of the side wall B, and the projections C6 and C7 of the side wall C. The insertion holes E11 ′, E12 ′, E13 ′, E14 ′, B1 ′, C6 ′, C7 ′, D31 ′, D32 are provided at positions corresponding to the protrusions D31, D32, D33 of the shield plate D1 (D). ', D33' are formed. Further, the cuts C4 ′ and C5 ′ are formed at positions corresponding to the side portions C4 and C5 of the side wall C of the shield case 1.
[0058]
The hatched portion in FIG. 5 is a part of the portion that contacts the shield case 1 on the surface of the circuit board 2 when the circuit board 2 is attached to the shield case 1. Forming a land.
[0059]
Next, attachment of the circuit board 2 to the shield case 1 as described above will be described.
[0060]
In the present embodiment, as shown in FIG. 1, the protruding portions E11, E12, E13, and E14 of the shield case 1, the protruding portion B1 of the side wall portion B, the protruding portions C6 and C7 of the side wall portion C, and the shield plate D1. The protrusions D31, D32, D33 of (D) are respectively inserted into the insertion holes E11 ′, E12 ′, E13 ′, E14 ′, B1 ′, C6 ′, C7 ′, D31 ′, D32 ′, D33 ′ of the circuit board 2. While inserting, the side parts C4 and C5 of the side wall part C of the shield case 1 are fitted into the cuts C4 ′ and C5 ′ of the circuit board 2. Then, as described with reference to FIG. 3, the protrusion (E1) having the stopper (E4) is formed at the tip of the extension pieces E11, E12, E13, E14 of the shield case 1 in particular. The circuit board 2 can be easily attached to the shield case 1, and the circuit board 2 can be prevented from being inserted and removed.
[0061]
In this way, it is possible to perform good soldering by dipping while the circuit board 2 is attached and fixed to the shield case 1.
[0062]
At this time, a land made of a conductor film is appropriately formed around the insertion holes E11 ′, E12 ′, E13 ′, E14 ′, B1 ′, C6 ′, C7 ′, D31 ′, D32 ′, and D33 ′ of the circuit board 2. If this is done, it can be electrically connected by soldering to the protrusions inserted therein.
[0063]
Further, in the present embodiment, as described with reference to FIG. 5, since the land (the hatched portion in FIG. 5) is formed on the surface of the circuit board 2, the insertion hole and the shield of the circuit board 2 are used at the time of dipping. The solder is sucked up to the bumps of the case 1 and the shield case 1 and the circuit board 2 are soldered to the land. Accordingly, since the area to be soldered between the shield case 1 and the circuit board 2 is enlarged, the circuit board 2 can be more firmly fixed to the shield case 1 after dipping.
[0064]
In addition, this invention is not limited to the said embodiment, For example, it applies to the thing of the type where the circuit board similar to the prior art demonstrated using FIG.6 and FIG.10 is accommodated in a shield case. It is possible.
[0065]
【The invention's effect】
As described above, according to the present invention, the first protrusion of the extension piece of the shield case side wall is inserted and attached to the first insertion hole of the circuit board. The first insertion hole of the circuit board is locked between the stopper portion and the edge of the distal end portion of the extension piece around the stopper portion, so that the circuit board can be prevented from being inserted and detached. Here, since the extension piece can be formed by utilizing a portion that has been discarded at the time of forming the shield case, it can be realized with a simple configuration without incurring an increase in cost, and the tongue piece and the attachment piece as in the prior art described above. As described above, since a part of the side wall portion of the shield case is not formed by processing, there is no possibility that the mechanical strength of the shield case is lowered or the shape of the shield case is distorted.
[0066]
Therefore, according to the present invention, it is possible to perform dipping by preventing the circuit board from being inserted and coming off, and with a simple configuration, the mechanical strength of the shield case can be enhanced compared to that of the above prior art, Distortion of the shape of the shield case can be prevented.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a shield structure of a circuit board according to an embodiment of the present invention.
FIG. 2 is a development view of the shield case of the embodiment.
3 is a partial enlarged view of a peripheral portion of an extension piece of the shield case of FIG. 2. FIG.
4 is a partially enlarged view of the periphery of a shield plate of the shield case of FIG. 2;
FIG. 5 is a plan view showing a circuit board according to the embodiment.
FIG. 6 is an exploded perspective view showing a shield structure of a conventional circuit board.
7 is a partially enlarged side view of the peripheral portion of the tongue piece of the shield case of FIG. 6;
8 is a view showing a support structure in the shield structure of the circuit board shown in FIG. 6;
FIG. 9 is a side perspective view showing a tongue piece for preventing insertion and falling-off of a circuit board in a conventional circuit board shield structure.
FIG. 10 is an exploded perspective view showing a shield structure of a conventional circuit board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shield case 2 Circuit board A1, A2, B, C Shield case side wall part C6, C7 Projection part (2nd projection part) of side wall part C
D, D1 Shield plate E2, E11, E12, E13, E14 Extension piece E1 Projection of extension piece (first projection)
E4 Protrusion stopper C6 ', C7' Circuit board insertion hole (second insertion hole)
E11 ′, E12 ′, E13 ′, E14 ′ Circuit board insertion hole (first insertion hole)

Claims (5)

In the circuit board shield structure in which a frame-shaped shield case is attached to the circuit board,
On the side wall portion of the shield case, an extension piece extending to the side to which the circuit board is connected is formed in an L-shape at the edge opposite to the side to which the circuit board is connected,
A first protrusion is formed at the distal end of the extension piece , and the first protrusion includes a key-shaped stopper for preventing insertion and falling off protruding sideways,
A first insertion hole is formed in the circuit board at a position corresponding to the first protrusion,
The first protrusion is inserted and attached to the first insertion hole ,
The extension piece is formed at a corner portion of the shield case,
In addition, a side projection is provided on a side edge of the extension piece, and the side projection is provided on the other side wall provided perpendicular to the side wall of the shield case, which is opposed to the side projection. A shield structure for a circuit board, characterized in that an insertion hole for fitting and locking is provided . The circuit board shield structure according to claim 1, wherein the first protrusion is formed at an intermediate position of a tip of the extension piece. At least one edge of the circuit board extends outward from the shield case, and a second protrusion is formed on a side wall of the shield case on the side where the circuit board extends outward from the shield case. The circuit board is formed with a second insertion hole at a position corresponding to the second protrusion, and the second protrusion is inserted and attached to the second insertion hole. Item 3. A circuit board shield structure according to Item 1 or 2 . 4. The circuit board shield structure according to claim 1, wherein a land is formed at least at a part of a contact portion between the shield case and the circuit board . The shield structure for a circuit board according to any one of claims 1 to 4, wherein the shield case is provided with a shield plate provided on a side wall portion .

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