JP3065472U - Printed circuit board shield structure - Google Patents

Abstract

(57) Abstract: To provide a shield structure of a printed circuit board having a shield structure for a board unit or a predetermined circuit portion on the board, wherein stable shield contact between shield members is obtained. A peripheral wall shield plate that shields at least a predetermined circuit portion to be shielded and that partitions a predetermined periphery of the circuit portion, and a flat component that covers and shields a component mounting surface of a printed circuit board. A surface shield plate, a shield structure of a printed circuit board comprising a flat bottom shield plate that covers and shields the bottom surface side of the printed circuit board, wherein the component surface side peripheral wall shield plate upper periphery and the component surface shield plate, A predetermined gap in which a conductive elastic material can be interposed so that the conductive elastic material can elastically contact therewith, the conductive elastic material is provided, and the conductive elastic material is a conductive elastic material; The shield structure of the printed circuit board, which is adhered to the peripheral wall shield plate and adheres to the area that comes into contact with the periphery.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a shield structure of a printed circuit board having a shield structure for a substrate or a predetermined circuit portion on the substrate.

[0002]

[Prior art]

 Some printed circuit boards mounted on equipment have a shield box structure for each circuit board or a predetermined circuit part on the circuit board to prevent leakage or intrusion of electromagnetic waves between adjacent circuit boards or circuits. In some cases, accurate shielding is required. The prior art will be described below with reference to an external view of a shield structure for a predetermined circuit portion of a printed circuit board in FIG. 2 and a partial side sectional view in which a main part of the shield structure in FIG. 3 is enlarged. The main components are a printed circuit board 10 having peripheral wall shield plates 31 and 32, a component surface shield plate 12, and a bottom surface shield plate 13. The shield structure may be partially applied to a circuit portion to be shielded on the print substrate 10, divided into a plurality of portions, or applied to the entire surface. FIG. 2 shows an example in which the invention is applied to a part of a printed circuit board.

[0003] The peripheral wall shield plates 31 and 32 shown in FIG. 3A are shield plates that partition the periphery of the circuit part in a predetermined manner. One of the component side peripheral wall shield plates 31 is a metal plate material that covers the upper surface of the substrate, and is formed with convex terminals 35 (see FIG. 3B) at a predetermined pitch. The convex terminals 35 are pressed into the substrate. After that, it is solder-dipped and fixed to the circuit ground. The height of the component surface side peripheral wall shield plate 31 is a predetermined height that is higher than the components of the mounted components. The bottom side peripheral wall shield plate 32 is a metal plate material that covers the lower surface side of the substrate, and the convex terminal 35 is pressed into the substrate in the same manner as described above and fixed by soldering using a plate material of a predetermined height.

The component-side shield plate 12 is a flat plate having four sides bent and reinforced, and is a plate-like shield plate that covers the upper part of the component mounting surface of the printed board 10. For example, metal bosses 22 are attached at four places, for example. The metal boss 22 is a spacer having a predetermined height so that the component surface shield plate 12 does not hit a component of a mounted component. One end is attached to the component surface shield plate 12 by caulking, and the other end is a printed board. A screw hole is formed to abut the earth electrode surface and screw it. A ground electrode surface and a mounting hole are formed in the printed circuit board 10 at the corresponding position. As a result, the upper surface of the printed circuit board 10 is electrically shielded and grounded. There is also a mode in which a large number of punching holes are formed partially or a mesh-shaped shield plate is used in consideration of air permeability and heat radiation.

The bottom shield plate 13 is also a flat plate having four sides bent and reinforced, and is a plate-shaped shield plate that covers the lower surface of the printed circuit board 10. At the corresponding position where the ground electrode surface of the printed circuit board 10 is formed, as shown in FIG. 3 (a), a projection is formed by pressing to form a projection 26 having a height of about several millimeters. A stop hole is formed in the center of the. The case of this figure is an example of taper processing corresponding to a countersunk screw. The mounting method is an example of a structure in which the component surface shield plate 12 and the bottom surface shield plate 13 are located at the same hole position, and are fastened together with a countersunk screw 24. Incidentally, instead of forming the convex portion 26, there is also a form in which the above-mentioned boss is crimped. The bottom shield plate 13 may be a punched hole or a mesh-shaped shield plate in consideration of air permeability and heat radiation. There is also a form in which a steel sheet subjected to electrical insulation treatment is used on the surface approaching the pattern surface, or an insulating sheet is attached.

By the way, although the upper end of the component-side peripheral wall shield plate 31 shown in the position of FIG. 3A and the component-side shield plate 12 are designed to be in electrical contact with each other, the component-surface-side peripheral wall shield plate is designed. Due to variations in the soldering of the substrate 31 and variations in the arrangement such as height deviation, deviation, inclination and the like due to the warpage of the substrate itself, the two may not always be able to electrically contact accurately. In this case, the predetermined shielding effect cannot be expected depending on the gap between the non-contact portions, and the contact is unstable. This is not preferable in practical use. On the other hand, in the case where the metal bosses 22 are provided at many locations, although a predetermined shielding effect is obtained as a result of being electrically connected to each boss point, it is not possible to provide the metal bosses 22 at many locations. However, this is not practical because it limits the number of components that can be mounted and limits the placement.

[0007]

[Problems to be solved by the invention]

 As described above, in the related art, there is a case where a predetermined shielding effect cannot be stably expected due to variations in arrangement and contact instability, and there is a practical difficulty in this point. Therefore, the problem to be solved by the present invention is to provide a printed circuit board having a shield structure for a substrate unit or a predetermined circuit portion on the substrate, and the shield structure of the printed circuit board capable of obtaining a stable shield contact between the shield members. It is to provide.

[0008]

[Means for Solving the Problems]

 First, in order to solve the above-mentioned problems, in the configuration of the present invention, the peripheral wall shield plates 31 and 32 for shielding at least a predetermined circuit portion to be shielded and for shielding a predetermined periphery of the circuit portion are shielded. A flat component surface shield plate 12 that covers and shields the component mounting surface (component surface) of the printed circuit board 10; and a flat bottom shield plate 13 that covers and shields the bottom surface of the printed substrate 10. The peripheral wall shield plates 31 and 32 are shield plates for partitioning the periphery of the circuit portion in a predetermined manner, and the component side peripheral wall shield plate 31 for shielding the component surface side. And a bottom side peripheral wall shield plate 32 for shielding the bottom side. The component side peripheral wall shield plate 31 is surrounded by a predetermined uniform height higher than the component of the mounted component. A metal plate is used, and the side that is in circumferential contact with the substrate surface is provided with a convex terminal 35 and soldered and fixed at predetermined intervals to the circuit ground of the substrate, and the bottom side peripheral wall shield plate 32 is surrounded at a predetermined uniform height. A metal plate is provided, and a side which is in contact with the substrate surface is provided with a convex terminal 35 and is fixed to a circuit ground of the substrate at a predetermined interval by soldering. The component surface shield plate 12 is a flat plate which covers the upper surface of the printed circuit board 10. A plurality of metal bosses 22 having a length corresponding to the height of the peripheral wall shield plate 31 on the component surface side are caulked and attached to the component surface shield plate 12. The printed circuit board 10 has a stop hole in which a ground electrode surface is formed at the position of the printed circuit board 10 in contact with the other end of the printed circuit board 10. The printed circuit board 10 is screwed and fixed to electrically connect the upper surface of the substrate to the ground. Lower surface of printed circuit board 10 It is a flat shield plate that covers the printed circuit board 10. The printed circuit board 10 has a stop hole in which a ground electrode surface is formed at the position of the substrate surface to be in contact with, and a convex portion 26 and a stop hole are formed at a position facing the stop hole. In the shield structure of the printed circuit board provided with the shield structure, the lower surface of the substrate is electrically fixed and screwed, and the conductive structure is provided between the upper peripheral portion of the peripheral surface shield plate 31 on the component surface side and the shield plate 12 on the component surface. A predetermined gap in which the conductive elastic material 50 can be interposed so as to be elastically contactable; and a conductive elastic material 50. The conductive elastic material 50 is a conductive elastic material. A shield structure for a printed circuit board, which is adhered to a back surface and adhered to a portion that comes into contact with the periphery of the peripheral wall shield plate 31. According to the invention, in a printed circuit board having a shield structure for a substrate unit or a predetermined circuit part on the substrate, a printed circuit board in which a conductive elastic material is attached and a stable shield contact between the shield members is obtained. Shield structure can be realized.

The conductive sheet 56 is a protective sheet that protects the conductive elastic member 50. The conductive sheet 56 is adhered to the surface of the conductive elastic member 50 and is connected to the component surface side peripheral wall shield. There is the above-described shield structure for a printed circuit board, which is in electrical contact with the sharp edge at the upper periphery of the plate 31.

In addition, there is the above-mentioned shield structure of the printed circuit board, wherein the shield is applied to a part, the whole, or a plurality of portions of the printed circuit board 10.

[0011]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings together with examples.

The present invention will be described below with reference to FIG. Elements corresponding to those of the conventional configuration are denoted by the same reference numerals, and description of overlapping parts will be omitted. The essential components include the printed circuit board 10 having the peripheral wall shield plates 31 and 32, the component surface shield plate 12, the bottom surface shield plate 13, the conductive elastic material 50, and the conductive sheet 56. This is a configuration in which a conductive elastic material 50 and a conductive sheet 56 are added to the conventional configuration. Here, in the present invention, even if there is a variation in the arrangement such as soldering of the component-side peripheral wall shield plate 31 between the upper side of the component-side peripheral wall shield plate 31 and the component-side shield plate 12, the conductivity is maintained. A predetermined gap, for example, 2 mm, which can be appropriately pressed with the elastic material 50 interposed therebetween, is provided.

The conductive elastic material 50 is a conductive elastic material, and is, for example, a rubber rubber material or sponge material containing carbon. In addition, there is a rubber shield material in which a large number of needle-like metal wires are buried between upper and lower surfaces of a rubber rubber material in a penetrating state. The conductive elastic material 50 is attached to at least the periphery of the rear surface of the component surface shield plate 12 which is in contact with the upper peripheral portion (see FIG. 1A) of the component surface side peripheral wall shield plate 31 with a conductive adhesive or the like. Thereby, there is obtained an advantage that stable shield contact between the shield members of the component surface shield plate 12 and the component surface side peripheral wall shield plate 31 is possible.

The conductive sheet 56 is a sheet material having conductivity for protecting the rubber material, which is the conductive elastic material 50, from being cut or separated by the upper and peripheral edges of the component surface side peripheral wall shield plate 31. Then, this is surface-bonded to the surface of the conductive elastic material 50. When the conductive elastic material 50 having a strength that does not need to be practically protected is used, the conductive sheet 56 may be omitted.

[0015]

[Effect of the invention]

 The present invention has the following effects from the above description. As described above, according to the present invention, a predetermined gap is provided between the component side shield plate 31 on the component side and the component side shield plate 12, and a conductive elastic material is provided in the gap. Is provided, even if there is a variation in soldering of the peripheral surface shield plate 31 on the component side, a stable electrical elastic contact is obtained between the two, resulting in a long period of time. A great advantage is obtained in that a stable and good shielding effect can be obtained continuously.

[Brief description of the drawings]

FIG. 1 is an enlarged partial sectional side view of a main part of the present invention.

FIG. 2 is an external front view and a side view of a conventional shield structure example for a predetermined circuit portion of a printed circuit board.

FIG. 3 is a partial sectional side view in which a main part of a conventional shield structure is enlarged, and a perspective structure example of a peripheral wall shield plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Printed circuit board 12 Component surface shield plate 13 Bottom shield plate 22 Metal boss 24 Countersunk screw 26 Convex part 31 Component surface side peripheral wall shield plate 32 Bottom side peripheral wall shield plate 35 Convex terminal 50 Conductive elastic material 56 Conductive sheet

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[Procedure amendment]

[Submission date] August 24, 1999 (1999.8.2
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims for utility model registration

[Correction method] Change

[Correction contents]

[Utility model registration claims]

Claims (3)

[Utility model registration claims] 1. A peripheral wall shield plate for shielding at least a predetermined circuit portion to be shielded and for partitioning a predetermined periphery of the circuit portion, and covering a component mounting surface (component surface) of a printed circuit board. A shield structure of a printed circuit board including a flat component surface shield plate for shielding, and a flat bottom shield plate for covering and shielding the bottom side of the printed circuit board, wherein the peripheral wall shield plate surrounds the circuit portion. A shield plate for partitioning in a predetermined manner, comprising a component surface side peripheral wall shield plate for shielding the component surface side and a bottom surface peripheral wall shield plate for shielding the bottom surface side. A metal plate that surrounds the board at a high and uniform height is fixed to the circuit ground of the board by soldering at predetermined intervals on the side that is in contact with the board surface. The shield plate is a metal plate material surrounding the board at a predetermined uniform height, and a side that is in contact with the board surface is soldered and fixed to a circuit ground of the board at a predetermined interval. A plurality of metal bosses having a length corresponding to the height of the peripheral wall shield plate on the component surface side are caulked and attached to the component surface shield plate. The printed circuit board has a stop hole formed with a ground electrode surface at a position on the board surface in contact with the other end, and is screwed and fixed to electrically connect the upper surface of the board to the ground. A shield plate that covers the lower surface of the printed circuit board, and has a stop hole in which a ground electrode surface is formed at a board surface position of the printed board in contact with the shield board.
In a shield structure of a printed circuit board having the shield structure, a convex portion and a stop hole are formed at positions opposed thereto and screw-fixed to electrically ground the lower surface of the substrate. A predetermined gap in which a conductive elastic material can be interposed so as to be elastically contactable between the upper periphery and the component surface shield plate, the conductive elastic material being provided, wherein the conductive elastic material is a conductive elastic material A shield structure for a printed circuit board, which is adhered to a back surface of the component surface shield plate and is adhered to a portion that comes into contact with the periphery on the peripheral wall shield plate. 2. A conductive sheet, comprising: a protective sheet for protecting the conductive elastic material, wherein the conductive sheet is adhered to a surface of the conductive elastic material and is provided on an upper peripheral portion of the peripheral wall shield plate on the component side. The shield structure for a printed circuit board according to claim 1, wherein the shield structure electrically contacts the printed circuit board. 3. The shield structure for a printed circuit board according to claim 1, wherein the shield is applied to a part, all, or a plurality of portions of the printed circuit board.