JP5258029B2 - Electronics - Google Patents

Description

  The present invention relates to a shield gasket provided between objects for preventing propagation and radiation of electromagnetic wave noise between both objects.

  Referring to FIG. 1A, this type of shield gasket has a core material 1 having elasticity such as urethane foam and rubber, and a conductive layer 2 such as a conductor cloth and metal foil formed around the core material 1. doing. This shield gasket is disposed between the object 10 and the object 20.

  In addition, the technique regarding this kind of shield gasket is disclosed by patent documents 1-3, for example.

JP 2001-197686 A JP 2002-058170 A JP 2006-0676759 A

  If both of the objects 10 and 20 shown in FIG. 1 (a) are conductive and both objects have different potentials, as shown in FIG. 1 (b), the object 10 and the object 20 is short-circuited by the conductive layer 2, and the operation of the electric circuit including both objects is hindered. Further, even when at least one of the objects 10 and 20 is a circuit board, and there are a plurality of pattern wirings having different potentials in a region on the surface of the circuit board that is in contact with the shield gasket, Is short-circuited by the conductive layer 2, which hinders the operation of the electric circuit.

  As a countermeasure, insulation treatment is applied to the surface of the object or a region in contact with the conductive layer of the shield gasket among a plurality of pattern wirings having different potentials, or a plurality of pattern wirings having different potentials to each other are electrically connected to the gasket. It was necessary to arrange in a position where it did not touch the layer.

  These measures need to be taken over a wide range considering the deformation of the shield gasket in practical use, and the shield gasket needs to be precisely placed (pasted) in a limited position, improving workability. Inferior.

  Therefore, the problem of the present invention is that even if two objects to be applied are conductive and have different potentials from each other, or even if the object has a plurality of pattern wirings having different potentials from each other, It is an object of the present invention to provide a shield gasket that can be easily arranged without the risk of a short circuit.

According to the present invention, in a shield gasket provided between the first and second objects for preventing the propagation and radiation of electromagnetic wave noise between the two objects , the conductive material having a string shape and having flexibility and elasticity. And a flexible insulating layer formed in an annular shape around the main body in a cross-sectional shape perpendicular to the longitudinal direction of the string .

According to the present invention, and the shield gasket, a first object, a first component electrical signal to at least a portion is passed through a second object, an electrical signal to at least partially An electronic device having a second component to be flowed is obtained.

  The shield gasket according to the present invention is a short circuit between different potential parts even if two objects to be applied are conductive and have different potentials from each other, or even if the object has a plurality of pattern wirings having different potentials from each other. There is no fear of this, and it can arrange easily.

Shield gasket according to the invention is provided between the first and second objects, electromagnetic noise between both objects propagate in shielding gasket to prevent radiation exhibits a string-like, conductive having flexibility and elasticity And a flexible insulating layer formed in an annular shape around the main body in a cross-sectional shape perpendicular to the longitudinal direction of the string .

  The present inventor believes that electromagnetic wave noise is a kind of AC electric signal, and thus by having the insulating layer as described above, the first object and the second object are capacitively coupled rather than in direct contact. It has been found that the propagation and radiation of electromagnetic noise between both objects can be prevented. By providing the insulating layer, it is assumed that the first object and the second object are electrically conductive and have different potentials from each other, or have a plurality of pattern wirings having different potentials from each other. Even if it exists, there is no possibility of a short circuit between parts of different electric potential, and this shield gasket can be arranged easily.

Hereinafter, reference examples 1 and 2 will be described with reference to the drawings, and then examples of the present invention will be described.

[ Reference Example 1]
Referring to FIG. 2 and FIG. 3A, the shield gasket according to Reference Example 1 of the present invention includes a first object 10 as a first part through which an electric signal flows through at least a part of an electronic device (not shown), This is a shield gasket that is provided between the second object 20 as a second part through which an electric signal flows through at least a part of the electronic device, and prevents propagation and radiation of electromagnetic wave noise between the two objects.

  As shown in FIG. 2, the shield gasket has a string shape so that a necessary amount (length) can be cut and used. Further, it has at least one of flexibility and elasticity, and at least has a conductive portion extending from the first object 10 to the second object 20. More specifically, the shield gasket includes a core material 1 having an elastic string shape such as urethane foam and rubber, and a conductor cloth in which a cross-sectional shape perpendicular to the longitudinal direction of the string is formed around the core material 1 in an annular shape. And a conductive layer 2 such as a metal foil. Here, the conductive layer 2 functions as the conductive portion described above.

  Further, the present shield gasket is an insulating layer having at least one of flexibility and elasticity formed on at least one of a surface in contact with the first object 10 and a surface in contact with the second object 20 among the conductive portions. 3. More specifically, the insulating layer 3 has an annular cross section around the conductive layer 2.

  In the present invention, the cross-sectional shape of the string is not limited to a square shape, and may be a circle or an oval. However, when the cross section is circular or oval, there is a possibility of twisting when sandwiched between objects, and the conductive layer may contact the object without passing through the insulating layer, or conductive to the object. It is possible that the layers do not face each other with sufficient area. Therefore, when the cross section of the string is circular or oval so that the conductive layer faces the object with a sufficient area through the insulating layer regardless of the situation, the conductive layer and the insulating layer In both cases, the cross-sectional shape is preferably annular. In the present invention, the shield gasket may not have a string shape but may have a short cylindrical shape, a rectangular parallelepiped shape, or a substantially spherical shape. In this case, it is used as a spacer with a shielding function for maintaining the distance between objects. However, in the case of a substantially spherical shape, there is a possibility that it will be greatly deformed when sandwiched between objects, and the conductive layer may contact the object without going through the insulating layer, or the conductive layer may contact the object. It is possible that they do not face each other with a sufficient area. For this reason, in the case of a substantially spherical shape, both the conductive layer and the insulating layer are formed on the entire surface of the sphere so that the conductive layer faces the object with a sufficient area through the insulating layer regardless of the situation. It is preferred that

  Here, even if both of the objects 10 and 20 shown in FIG. 3A are conductive and both objects have different potentials, the shield gasket has the insulating layer 3. Therefore, the objects 10 and 20 having different potentials are not short-circuited. Therefore, the operation of the electric circuit including both objects is not hindered. In addition, as shown in FIG. 3B, the object 10 and the conductive layer 2 opposed thereto function as a capacitor C1 sandwiching the insulating layer 3 as a dielectric, and the object 20 and the conductive layer 2 opposed thereto are insulated. It functions as a capacitor C2 that sandwiches the layer 3 as a dielectric. Therefore, the object 10 and the object 20 are capacitively coupled by the capacitors C1 and C2 connected in series. Therefore, electromagnetic wave noise which is an AC electric signal is decoupled, and propagation and radiation of electromagnetic wave noise between both objects are prevented.

  Further, as shown in FIG. 4, at least one of the objects 10 and 20 (in this example, the object 20) is a circuit board, and different potentials are mutually within a region of the circuit board surface in contact with the shield gasket. Even if there are a plurality of pattern wirings 21a to 21c, since the shield gasket has the insulating layer 3, the plurality of pattern wirings are not short-circuited. Therefore, the operation of the electric circuit including both objects is not hindered. Moreover, when viewed as a distributed constant circuit, each of the pattern wirings 21a to 21c and the conductive layer 2 facing them function as a plurality of capacitors sandwiching the insulating layer 3 as a dielectric. Therefore, a plurality of pattern wirings are capacitively coupled by a plurality of capacitors. Therefore, electromagnetic noise that is an AC electrical signal is decoupled, and propagation and radiation of electromagnetic noise between a plurality of pattern wirings are prevented. In the present invention, the pattern wiring includes vias for connecting the front and back of the circuit board.

  Furthermore, as shown in FIG. 5, at least one of the two objects (in this example, the object 20) is a circuit board, and the other of the two objects is an arbitrary object regardless of whether it is conductive or non-conductive. Even though there are a plurality of pattern wirings 21a to 21c having different potentials in a region of the circuit board surface in contact with the shield gasket, the shield gasket is provided with the insulating layer 3 Therefore, a plurality of pattern wirings are not short-circuited. Therefore, the operation of the electric circuit including both objects is not hindered. Moreover, when viewed as a distributed constant circuit, each of the pattern wirings 21a to 21c and the conductive layer 2 facing them function as a plurality of capacitors sandwiching the insulating layer 3 as a dielectric. Therefore, a plurality of pattern wirings are capacitively coupled by a plurality of capacitors. Therefore, electromagnetic noise that is an AC electrical signal is decoupled, and propagation and radiation of electromagnetic noise between a plurality of pattern wirings are prevented.

  In addition, this shield gasket specifies the capacitance of the capacitor by specifying the material, thickness, and area of the conductive layer 2 facing the object, the relative dielectric constant of the insulating layer 3, etc. It is possible to take EMC measures suitable for the frequency band, or to apply to high voltage equipment with a high breakdown voltage.

[ Reference Example 2]
The shield gasket according to Reference Example 2 of the present invention is different from Reference Example 1 in the configuration of the insulating layer. For this reason, the description of the same or similar parts as in Reference Example 1 is omitted.

Referring to FIG. 6 (a), the shield gasket according to the reference example 2 of the present invention has a first object (FIG. 6) in addition to the insulating layer 3 which is an insulating coating having an annular shape in a cross-sectional shape perpendicular to the longitudinal direction. It further has an insulating adhesive or insulating adhesive tape 4 applied or affixed to the surface in contact with (not shown).

FIGS. 6B and 6C and FIGS. 7A to 7C are Modifications 1 to 5 of Reference Example 2. FIG.

  Referring to FIG. 6 (b), the shield gasket according to the first modification example has an insulating property formed across the surface in contact with the second object (not shown) and the two side surfaces in the cross-sectional shape orthogonal to the longitudinal direction. It has an insulating layer 3 that is a coating, and an insulating adhesive or an insulating adhesive tape 4 that is applied or pasted to a surface in contact with a first object (not shown).

  Referring to FIG. 6 (c), the shield gasket according to the modified example 2 is formed across the surface in contact with the second object (not shown) and each part of the two side surfaces in the cross-sectional shape orthogonal to the longitudinal direction. And an insulating layer 3 that is an insulating coating, and an insulating adhesive or insulating adhesive tape 4 applied or pasted on a surface in contact with a first object (not shown). The conductive layer 2 is exposed at the remaining portions of the two side surfaces.

  Referring to FIG. 7 (a), the shield gasket according to Modification 3 is an insulating layer that is an insulating coating formed on a surface in contact with a second object (not shown) in a cross-sectional shape orthogonal to the longitudinal direction. 3 and an insulating adhesive or insulating adhesive tape 4 applied or pasted on a surface in contact with a first object (not shown). Note that the conductive layer 2 is exposed on the two side surfaces.

  Referring to FIG. 7B, the shield gasket according to the modified example 4 is an insulating layer that is an insulating coating formed on a surface in contact with a first object (not shown) in a cross-sectional shape orthogonal to the longitudinal direction. In addition to 3, an insulating adhesive or insulating adhesive tape 4 applied or pasted on the insulating layer 3 is further provided. Note that the conductive layer 2 is exposed on the surface in contact with the second object (not shown) and the two side surfaces.

  Referring to FIG. 7C, the shield gasket according to the modified example 5 is an insulating layer that is an insulating coating formed on a surface in contact with a first object (not shown) in a cross-sectional shape orthogonal to the longitudinal direction. 3. The insulating layer 3 is extended at both ends of the cross section. Note that the conductive layer 2 is exposed on the surface in contact with the second object (not shown) and the two side surfaces.

[ Example]
Shield gasket according to embodiments of the present invention, the configuration of the site of conductive differs from the reference example 1. For this reason, the description of the same or similar parts as in Reference Example 1 is omitted.

Referring to FIG. 8, a shield gasket according to an embodiment of the present invention has a flexible conductive body 2 '. The main body 2 ′ functions as a conductive part. More specifically, the conductive layer 2 is made of a conductor string, a metal wire, or the like. Further, the present shield gasket is an insulating layer having at least one of flexibility and elasticity formed on at least one of a surface in contact with the first object 10 and a surface in contact with the second object 20 among the conductive portions. 3. More specifically, the insulating layer 3, the cross-sectional shape around the present body 2 'are formed annularly. The conductive main body 2 ′ may have elasticity in addition to flexibility. In this case, it functions as a spring gasket having a specific shape such as a U-shape, C-shape, or O-shape between objects.

  The present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible within the technical scope described in the claims.

It is a figure which shows the shield gasket by the technique relevant to this invention, (a) is sectional drawing, (b) is a conceptual diagram like an equivalent circuit. It is a perspective view which shows the shield gasket by the reference example 1 of this invention. It is a figure which shows the shield gasket shown by FIG. 2, (a) is sectional drawing, (b) is a conceptual diagram like an equivalent circuit. It is sectional drawing for demonstrating the application example of the shield gasket shown by FIG. It is sectional drawing for demonstrating the application example of the shield gasket shown by FIG. It is a figure which shows the shield gasket by the reference example 2 of this invention, (a) is sectional drawing of the reference example 2, (b) and (c) are sectional drawings of the modification of the reference example 2. FIG. (A)-(c) is sectional drawing which shows the modification of the reference example 2 of this invention. It is a sectional view showing a shielding gasket according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core material 2 Conductive layer 2 'Main body 3 Insulating layer 4 Adhesive or adhesive tape 10 1st object 20 2nd object 21a-21c Pattern wiring

Claims (1)

First and second objects spaced apart from each other;
And a shield gasket provided between said first and said second object,
At least one of the first and second objects is a circuit board, and the circuit board has a plurality of pattern wirings having different potentials from each other,
The shield gasket is in the form of a string, and has a flexible and elastic conductive body, and a flexible insulation formed in an annular shape around the body in a cross-sectional shape perpendicular to the longitudinal direction of the string. And the conductive body is disposed so as to face the plurality of pattern wirings of the circuit board,
When viewed as a distributed constant circuit, each of the plurality of pattern wirings on the circuit board and the conductive main body of the shield gasket facing them function as a plurality of capacitors sandwiching the insulating layer as a dielectric. Accordingly , an electronic apparatus characterized in that the plurality of pattern wirings are capacitively coupled by a plurality of capacitors, thereby preventing propagation and radiation of electromagnetic noise between the plurality of pattern wirings .

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