JP2004363581A - Circuit board module, circuit board housing, and electromagnetic shield plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board module and a circuit board housing which maintain a stable, reliable electromagnetic shielding effect over an extended time period, and an electromagnetic shield plate used for them. <P>SOLUTION: This electromagnetic shield plate consists of an electromagnetic shielding member having electrical conductivity and a front panel which is provided on one end portion of the electromagnetic shielding member and has electrical conductivity. The front panel is secured to a grounded housing while securing electrical conductivity so as to securely ground the electromagnetic shield plate. In addition, the board insertion opening in the housing is sealed to provide electromagnetic shielding between the circuit boards and between the outside of the housing and the circuit boards. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a circuit board container capable of mounting a plurality of circuit boards in a housing in parallel, a circuit board module having a plurality of circuit boards mounted thereon, and an electromagnetic shield plate for shielding the circuit board from electromagnetic waves.

  As an example of a technique related to electromagnetic shielding of a circuit board, a configuration in which an electromagnetic shielding plate is provided on the front surface of a circuit board housing is known, but no consideration is given to electromagnetic shielding between a plurality of substrates inside the housing ( For example, see Patent Document 1).

  Further, there is known a configuration in which a conductive plate-shaped member is attached to a lower portion of a circuit board in parallel with a spacer interposed therebetween for the purpose of shielding electromagnetic noise between the circuit boards (for example, see Patent Document 2). In this configuration, since the electromagnetic shielding member and the housing are electrically connected via the conductive guide rail, VME (Versa Module Europe, IEEE standard) configured with an insulating guide rail. It is difficult to apply a housing that conforms to the standards such as, because it must be replaced with a conductive guide rail or provided with a claw called a shield finger for electrically connecting the plate-shaped member and the guide rail. There was a problem that it became expensive. Also, at this time, the electrical connection between the plate-shaped member and the grounded housing depends on the contact with the shield finger. There was a problem in terms of gender. Also, a circuit board mounted in a slot of a housing compliant with a standard such as a generally-available VME must be modified to make a hole for attaching a spacer for fixing a plate-shaped member, which is more expensive. There was also the problem of becoming.

JP-A-3-88396

JP-A-8-250886

  An object of the present invention is to provide a circuit board module having a stable and reliable electromagnetic shielding effect over a long period of time, a circuit board container, and an electromagnetic shield plate used for the circuit board module.

  In order to achieve the above object, an embodiment of the present invention provides a circuit board container having a guide rail and a housing for holding a circuit board, and a plurality of electromagnetic shields alternately arranged between the plurality of circuit boards. And a plate.

  Also, the electromagnetic shield plate is constituted by an electromagnetic shielding member having conductivity and a front panel having conductivity provided at an end thereof, and the front panel is secured to a grounded housing by securing electrical conduction. The electromagnetic shield plate is securely grounded, and the board insertion opening of the housing is sealed to perform electromagnetic shielding between the circuit boards and electromagnetic shielding between the circuit board and the outside of the housing.

  According to the present invention, it is possible to provide a circuit board module, a circuit board housing, and an electromagnetic shield plate having a stable and reliable electromagnetic shielding effect for a long time.

  Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a perspective view of an electromagnetic shield plate, and FIG. 2 is a perspective view of a circuit board container.

  As shown in FIG. 1, the electromagnetic shield plate 4 includes an electromagnetic shield member 1 and a conductive front panel 3 attached to an end of the electromagnetic shield member 1. The front panel 3 is provided for the effect of preventing electromagnetic noise from entering the circuit board 7 and radiating the electromagnetic noise from the circuit board 7 and for reinforcement. A mounting member 14 for attaching the front panel 3 to the electromagnetic shielding member 1 is made of a conductive material, so that the electromagnetic shielding member 1 and the front panel 3 are electrically connected. Further, handles 2 are provided above and below the front panel 3 so that the handle 2 can be easily inserted into and removed from the housing 6 shown in FIG. Reference numeral 2 denotes a handle for handling the electromagnetic shield plate 4.

  In FIG. 2, the circuit board housing has a housing 6, an upper wall, a bottom wall, two side walls, and a backboard 8, and a rectangular space is formed. The housing 6 is a metal box on which circuit boards 7 are mounted in parallel, and a back board 8 is connected to the rear part. A wiring pattern is formed on the back board 8, and a connector for connecting the circuit board 7 is provided. The circuit board 7 forms an electric circuit using electronic components on the board, and a connector for connection to the back board 8 is provided at the rear end. Guide rails 9 for guiding the insertion of the circuit board 7 are attached to the upper and lower portions inside the housing 6 so as to face each other. When the circuit board is inserted along the guide rails 9, the connector of the back board 8 and the circuit The connector of the substrate 7 is electrically connected. As shown in FIG. 2, the electromagnetic shield plate 5 is inserted along the guide rail 9 so as to sandwich the circuit board 7 in a board slot adjacent to both sides of the circuit board 7, which is a source of electromagnetic noise or easily affected. After the electromagnetic shield plate 4 is inserted, the front panel 3 is fixed to the housing 6 with screws. Thus, a circuit board module is constituted by attaching a plurality of circuit boards and a plurality of electromagnetic shield plates to the circuit board container.

  According to the present embodiment, the front panel 3 is provided on the electromagnetic shield plate 5 and the front panel 3 is fixed to the housing 6 by screws, so that the electromagnetic shield plate 4 is electrically secured to the grounded housing 6. , It is possible to obtain a stable and reliable electromagnetic shielding effect over a long period of time. Further, since the front panel 3 is grounded, an effect of shielding electromagnetic noise incident on the circuit board 7 through the board insertion opening and electromagnetic noise radiated from the circuit board 7 can be obtained. In addition, although the fixing method by screwing was used for both the purpose of fixing and electrical conduction, it is not necessary to use screwing as long as these fixing methods, such as rivets and clips, can achieve these objects.

  In addition, since the electromagnetic shield plate 5 is grounded via the front panel, the electromagnetic shield plate 4 is inserted into a slot between boards on which arithmetic elements and the like that handle a high-frequency clock that may cause interference of electromagnetic noise are mounted. By inserting, it is possible to shield electromagnetic noise radiated from above the circuit board.

  Further, since the electromagnetic shield plate 5 is grounded via the front panel, the present invention can be applied to a case where an insulating guide rail 9 such as a housing conforming to a standard such as a commercially available VME is used. Modification such as replacement with a conductive guide rail is not required, so that it can be easily applied at low cost.

  Further, since the electromagnetic shield plate 5 can be inserted and removed independently, an effect such as excellent maintainability such as measurement, adjustment or repair of the circuit board can be obtained. Further, if a plurality of electromagnetic shield plates 5 are added between circuit boards, a higher electromagnetic shielding effect can be obtained.

  Further, since the electromagnetic shield plate 5 can be inserted and removed independently, even if the shielding of electromagnetic noise was not considered at the beginning of the design, the electromagnetic shield plate 5 can be added to the empty slot to provide electromagnetic shield. An effect can be obtained.

  A second embodiment of the present invention will be described. FIG. 3 is a perspective view of the electromagnetic shield plate, in which a plate-like member 10 having mesh holes is used as the electromagnetic shield member. At this time, the size of the mesh holes is set to a hole diameter of １ ／ or less of the wavelength of electromagnetic noise to be shielded. As is well known, when an electromagnetic wave enters a metal plate, an eddy current is generated in the metal plate. At this time, by providing a large number of mesh-shaped holes like the plate-shaped member 10, a higher electromagnetic shielding effect can be obtained because of the action of canceling the generated eddy current. Further, since heat generated on the substrate is easily released through the mesh-shaped holes, the influence of the heat on the electronic components can be reduced. Furthermore, there is an effect that the electromagnetic shielding member can be reduced in weight by providing a large number of mesh holes.

  A third embodiment of the present invention will be described. FIG. 4 is a perspective view of the electromagnetic shield plate. As the electromagnetic shield member, a metal-plated metal or non-metal plate member 11 is used. In particular, a non-metallic plate member such as a resin is subjected to a metal plating process having a high conductivity, such as copper, for example, so that an electromagnetic shielding plate equivalent to the electromagnetic shield plate 5 composed of a single metal plate member is obtained. It is possible to configure the lightweight electromagnetic shield plate 5 while maintaining the noise shielding effect. In addition, by applying a metal plating process such as copper with high conductivity to a metal plate member having high magnetic permeability such as iron, a more effective electromagnetic shielding effect can be obtained.

  A fourth embodiment of the present invention will be described. FIG. 5 is a perspective view of the electromagnetic shielding plate. As an electromagnetic shielding member, an electromagnetic shielding sheet 12 is attached to a metal-plated metal or non-metallic plate-like member 11 to provide an electromagnetic noise shielding effect. Can be provided. In this case, if an electromagnetic shielding sheet having high electromagnetic shielding performance is used, a higher electromagnetic shielding effect can be obtained.

  In particular, when the electromagnetic shielding sheet 12 is attached to a nonmetallic plate member such as a resin, the electromagnetic shielding plate 5 can be made lightweight.

  As described above, the electromagnetic shield plate is provided with the front panel, and the front panel and the housing are screwed together, so that the electromagnetic shield plate can be reliably connected to the ground, so that the electromagnetic shield plate can be reliably grounded. Thus, a stable and reliable electromagnetic shielding effect can be obtained for a long time.

  Further, since the front panel is grounded, it is possible to shield electromagnetic noise from entering the circuit board from the board insertion opening and radiation of electromagnetic noise from the circuit board. Furthermore, since the electromagnetic shield plate is grounded via the front panel, it can be applied to a case using an insulating guide rail, so that it can be applied at low cost and easily.

  In addition, since the electromagnetic shield plate can be inserted and removed by itself, it is possible to obtain an effect that the maintainability such as measurement, adjustment, and repair of the circuit board is excellent. Furthermore, since the electromagnetic shield plate can be inserted and removed independently, even if the shielding of electromagnetic noise was not considered at the beginning of the design, if there is an empty slot in the housing, the electromagnetic shield plate Is added, an electromagnetic shielding effect can be obtained.

FIG. 1 is a perspective view of an electromagnetic shield plate according to a first embodiment of the present invention. The perspective view of the circuit board container by an embodiment of the present invention. FIG. 9 is a perspective view of an electromagnetic shield plate according to a second embodiment of the present invention. FIG. 9 is a perspective view of an electromagnetic shield plate according to a third embodiment of the present invention. FIG. 14 is a perspective view of an electromagnetic shield plate according to a fourth embodiment of the present invention.

Explanation of reference numerals

  DESCRIPTION OF SYMBOLS 1 ... Electromagnetic shielding member, 2 ... Handle, 3 ... Front panel, 4 ... Electromagnetic shield plate, 6 ... Housing, 7 ... Circuit board, 8 ... Backboard, 9 ... Guide rail, 10 ... Plate member, 11 ... Plate Shaped member, 12: electromagnetic shielding sheet, 14: mounting bracket.

Claims (20)

  A circuit board module, comprising: a circuit board container having a guide rail for holding a circuit board and a housing; and a plurality of electromagnetic shield plates alternately arranged between the plurality of circuit boards.   2. The circuit board module according to claim 1, wherein the guide rail is provided on an inner wall of the housing.   2. The circuit board module according to claim 1, wherein the housing forms a rectangular space by an upper wall, a bottom wall, a pair of side walls, and a backboard.   4. The circuit board module according to claim 3, wherein the back board is provided with a connector for connecting the circuit board, the circuit board is inserted along the guide rail, and connected to the connector.   4. The circuit board module according to claim 3, wherein the electromagnetic shield plate is inserted along a guide rail so as to sandwich the circuit board on both sides of the circuit board attached to the backboard.   2. The circuit board module according to claim 1, wherein the electromagnetic shield plate includes a conductive electromagnetic shielding member and a front panel.   7. The circuit board module according to claim 6, wherein the electromagnetic shield plate is fixed to the electromagnetic shield member and the housing while securing electrical continuity via the front panel. 8.   7. The circuit board module according to claim 6, wherein the electromagnetic shielding member includes a plurality of openings having a length equal to or less than １ ／ of the wavelength of the electromagnetic noise to be shielded.   7. The circuit board module according to claim 6, wherein the electromagnetic shielding member is plated with a conductive material.   7. The circuit board module according to claim 6, wherein an electromagnetic shielding sheet is attached to the electromagnetic shielding member.   A circuit board container having a first guide rail for holding a plurality of circuit boards and a housing, comprising a second guide rail on which a plurality of electromagnetic shield plates are alternately arranged between the circuit boards. A circuit board container, characterized in that:   The circuit board container according to claim 11, wherein the first guide rail and the second guide rail are provided on an inner wall of the housing.   12. The circuit board container according to claim 11, wherein the housing forms a rectangular space by an upper wall, a bottom wall, a pair of side walls, and a backboard.   14. The circuit according to claim 13, wherein the backboard is provided with a connector for connecting the circuit board, the circuit board is inserted along the first guide rail, and is connected to the connector. Substrate container.   14. The circuit board container according to claim 13, wherein the electromagnetic shield plate is inserted along the second guide rail so as to sandwich the circuit board on both sides of the circuit board attached to the backboard. .   12. The electromagnetic shielding plate according to claim 11, wherein the electromagnetic shielding plate has an electromagnetic shielding member and a front panel, and the electromagnetic shielding member and the housing are fixed to each other through the front panel while ensuring electrical continuity. Circuit board container.   An electromagnetic shield plate comprising: a conductive electromagnetic shielding member; and a conductive front panel provided at an end of the electromagnetic shielding member.   18. The electromagnetic shielding plate according to claim 17, wherein the electromagnetic shielding member is provided with a plurality of openings each having a length of 1/4 or less of the wavelength of the electromagnetic noise to be shielded.   18. The electromagnetic shield plate according to claim 17, wherein the electromagnetic shield member is a plate-shaped member that has been subjected to a plating process having conductivity. The electromagnetic shielding plate according to claim 17, wherein the electromagnetic shielding member is a plate-like member to which a conductive sheet is attached.

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