JP6400394B2 - Gasket, and circuit board laminate and electronic device using the same - Google Patents

Description

  The present invention relates to a gasket that is sandwiched between a plurality of conductors and used to electrically connect the plurality of conductors to each other.

  Conventionally, in order to ensure electrical continuity (hereinafter simply referred to as “conduction”) such as ground (GND) between conductors with gaps, such as between substrates and between a substrate and a metal cabinet. In addition, gaskets (conductors for electronic devices) are widely used.

  For example, the gasket described in Patent Document 1 is a periphery of a member to be compressed in which a cushion material that is a high compression layer and a core material that is a low compression layer having a higher elastic modulus than the cushion material are laminated in the compression direction. Is provided with a conductive sheet. By sandwiching the above-mentioned gasket between conductors that require conduction, the gaskets are compressed, and the conductive sheet is pressed against the conductor by the drag of the cushion material (the conductive sheet is pressed against the conductor). Mutual conduction between the conductors is ensured.

JP 2007-335820 A (released on December 27, 2007)

  However, the gasket described in Patent Document 1 has a problem that when the conductor is pressed from both ends of the gasket, the conductor is distorted to the outside of the gasket. Details will be described with reference to FIG. FIG. 10A is a schematic cross-sectional view showing a conventional gasket 100, and FIG. 10B is a view for explaining a state in which a metal plate is pressed from both ends of the gasket 100. FIG. As shown in FIG. 10A, the gasket 100 includes a core material 101 and a conductive layer 103. The core material 101 has cushioning properties. The conductive layer 103 is provided around the core material 101. One surface 103a of the gasket 100 and a surface 103b facing the surface 103a are in contact with the metal plate 104, respectively. In this state, when a force is applied to the two metal plates 104 in the opposing direction indicated by the arrows 105 and 106, that is, when the metal plate 104 is pressed against the gasket 100, as shown in FIG. In addition, a drag 107 that pushes back the metal plate 104 by the gasket 100 is generated by the cushioning property of the core material 101. The drag 107 is locally generated with respect to the metal plate 104 having an area larger than the surfaces 103 a and 103 b of the gasket 100, so that the metal plate 104 is distorted (swells) outside the gasket 100 by the drag 107. Various problems occur due to the distortion of the metal plate 104. For example, when the liquid crystal display is arranged on the opposite side of the gasket 100 of the metal plate 104, yellowing and pooling of the liquid crystal display occurs, and when the metal plate 104 is a substrate, peeling of mounted components or the like occurs. Occur.

  The present invention has been made in view of the above-described problems, and the object thereof is to suppress the distortion of a conductor that is caused by conducting a conductor such as a metal plate to each other through a gasket, and the distortion of the conductor. It is an object of the present invention to provide a gasket that can prevent the occurrence of problems.

  In order to solve the above-described problem, a gasket according to one embodiment of the present invention is configured such that the first conductor and the second conductor are mutually held by being sandwiched between a first conductor and a second conductor that are electrically conductive. In the gasket to be conducted, at least a part of the gasket is formed of a magnetic material having a property of a magnet, and the magnetic material has a magnetic force to attract the first conductor and the second conductor. .

  According to one aspect of the present invention, there is an effect that it is possible to suppress the distortion of a conductor that is generated due to the conduction of conductors through a gasket.

(A) And (b) is typical sectional drawing which shows the gasket which concerns on Embodiment 1 of this invention. It is typical sectional drawing which shows the gasket which concerns on Embodiment 2 of this invention. It is typical sectional drawing which shows the gasket which concerns on the modification of Embodiment 2 of this invention. (A) And (b) is typical sectional drawing which shows the gasket which concerns on Embodiment 3 of this invention. It is typical sectional drawing which shows the gasket which concerns on the modification of Embodiment 3 of this invention. 1 is an exploded view of a circuit board laminate using a gasket according to the present invention. FIG. It is a disassembled assembly drawing of the laminated body of the said circuit board. It is a disassembled assembly drawing of the laminated body of the said circuit board. It is a perspective view which shows the laminated body of the said circuit board. (A) And (b) is typical sectional drawing which shows the conventional gasket.

Embodiment 1
Hereinafter, the gasket 10 which concerns on Embodiment 1 of this invention is demonstrated in detail based on FIG. The gasket 10 is opposed to each other with a gap in a mobile phone or the like, and is sandwiched between a plurality of conductors that are electrically conductive, whereby the conductors are electrically connected to each other to have the same potential (for example, ground potential). Used for Here, the plurality of conductors are formed of a material that is attracted to the magnetic material when entering the magnetic field of the magnetic material. In other words, the plurality of conductors are conductors attracted by the magnet. In the present embodiment, the gasket 10 is sandwiched between the metal plate 50a (first conductor) and the metal plate 50b (second conductor) which are attracted to the magnetic material when entering the magnetic field of the magnetic material and are electrically conductive. By doing this, a form in which the metal plates 50a and 50b are electrically connected to each other is illustrated. However, the conductor is not limited to a metal plate.

[Gasket structure]
The structure of the gasket 10 is demonstrated below based on (a) of FIG. FIG. 1A is a schematic cross-sectional view showing a gasket 10 according to Embodiment 1 of the present invention. As shown in FIG. 1A, the gasket 10 is composed of a core material 1. Further, the core material 1 is composed of a magnetic material 2. The magnetic material 2 has the property of a magnet and attracts the metal plates 50a and 50b to the gasket 10 side. In other words, the magnetic material 2 can be paraphrased as an attraction portion having the properties of a magnet.

  In the present embodiment, the core material 1 is composed of the same magnetic material 2 as a whole, but is not limited thereto. The core material 1 only needs to be able to attract the metal plates 50a and 50b to the gasket 10 side by the magnetic field of the magnetic material 2, and at least a part of the core material 1 only needs to be made of the magnetic material 2 having the properties of a magnet. . For example, only the center part of the core material 1 may be comprised with the magnetic material 2 according to a use, and the core material 1 may be comprised by laminating | stacking the different magnetic material 2. FIG. Although the magnitude of the magnetic force of the magnetic material 2 is not particularly limited, specifically, a hard magnetic material (hard ferrite) such as a permanent magnet can be used as the magnetic material 2. The height, width, and depth of the magnetic material 2 may be appropriately set according to the gap between the metal plates 50a and 50b that conduct each other and the required electrical performance (contact resistance), and are not particularly limited. Absent.

[Gasket manufacturing method]
A method for manufacturing the gasket 10 will be described below. The gasket 10 is manufactured by cutting a rectangular magnetic material 2 having a predetermined thickness into a necessary width and depth. The width and depth to be cut are appropriately changed according to the gap between the metal plates 50a and 50b. For example, the gasket 10 can be a rectangular parallelepiped having a height of 4.5 mm, a depth of 6.80 mm, and a width of about 3.00 mm. Therefore, since the gasket 10 can be easily manufactured by cutting the magnetic material 2, the manufacturing cost of the gasket 10 can be reduced.

  In addition, it is preferable that the roughness of the upper surface (surface 11a) and the lower surface (surface 11b) of the magnetic material 2 in contact with the metal plates 50a and 50b is smaller because the contact area becomes larger and the contact resistance can be reduced. On the other hand, when a film formed by chemical conversion treatment, an oxide film, or the like is formed on the surfaces of the metal plates 50a and 50b for the purpose of preventing corrosion, for the purpose of breaking through the insulating film and bringing it into contact with the metal. In some cases, it is effective to increase the roughness of the upper surface (surface 11a) and the lower surface (surface 11b) of the magnetic material 2.

[Conduction of metal plate]
The mutual conduction | electrical_connection of the metal plates 50a and 50b in the gasket 10 is demonstrated below based on (a) of FIG. 1, and (b) of FIG. FIG. 1B is a diagram illustrating a state in which the metal plates 50 a and 50 b are attracted to the gasket 10. As described above, the gasket 10 is disposed in the gap between the metal plate 50a and the metal plate 50b that conduct each other. Specifically, as shown in FIG. 1A, the gasket 10 is disposed such that one surface 11a of the gasket 10 is in contact with the metal plate 50a and a surface 11b opposite to the surface 11a is in contact with the metal plate 50b. .

  Further, as shown in FIG. 1B, the metal plates 50 a and 50 b are attracted to the magnetic material 2 by the attractive force 30 due to the magnetic field of the magnetic material 2. In other words, the gasket 10 attracts the metal plates 50 a and 50 b toward the gasket 10 by the magnetic field of the magnetic material 2. For this reason, since the gasket 10 can sufficiently increase the contact pressure between the surface 11a and the metal plate 50a and the contact pressure between the surface 11b and the metal plate 50b, the contact resistance on the surface 11a and the surface 11b is reduced. be able to. As a result, the metal plates 50a and 50b can stably conduct each other between the metal plates 50a and 50b only by sandwiching the gasket 10 between the metal plates 50a and 50b. Therefore, mutual conduction between the metal plates 50a and 50b can be stably secured without pressing the metal plates 50a and 50b against the gasket. Moreover, since it is not necessary to press the metal plates 50a and 50b having a larger area than the surface 11a and the surface 11b of the gasket 10 against the gasket 10, distortion (swelling) of the metal plates 50a and 50b can be suppressed. As a result, the occurrence of problems due to the distortion of the metal plates 50a and 50b can be prevented. In the metal plates 50a and 50b, the conductor (metal plate) portion and the portion of the material attracted to the magnetic material 2 when entering the magnetic field of the magnetic material 2 may be configured as separate parts. Specifically, for example, the metal plates 50a and 50b are (1) a metal that is not attracted to the magnetic material 2, and (2) the outer side of (1) (on the side opposite to the surface facing the surface 11a in the metal plate 50a). And a material (metal, permanent magnet, or the like) that is disposed so as to be in contact with the surface) and is attracted to the magnetic material 2. Even in the case of the metal plate 50a having such a configuration, the metal plate 50a and the magnetic material 2 can be brought into contact with each other by being attracted by the attraction force 30 due to the magnetic field of the magnetic material 2 so as to be conductive. it can. Further, when the magnetic material 2 having a low resistance value is used as the magnetic material 2, the conduction between the metal plates 50a and 50b can be more stably performed.

[Fastening gasket]
The fixing of the gasket 10 will be described below with reference to FIG. Since the gasket 10 can attract the metal plates 50a and 50b to the gasket 10 side by the magnetic material 2, the gasket 10 can be fixed to the metal plates 50a and 50b without using an adhesive or the like. Thereby, compared with the case where an adhesive material is used for fixing the gasket 10, the man-hour and the adhesive material can be reduced, and the cost can be reduced.

  Further, for example, when it is desired to securely fix the gasket 10 to the metal plate 50b, it is possible to fix the gasket 10 to the metal plate 50b by applying a double-sided tape or the like to the surface 11b. In that case, the double-sided tape may increase the contact resistance on the surface 11b. At this time, by using a conductive double-sided tape for fixing the gasket 10, it is possible to prevent the contact resistance on the surface 11b from increasing. Furthermore, it is possible to prevent the contact resistance on the surface 11b from increasing by sticking the double-sided tape to the surface 11b so that a part of the surface 11b is exposed instead of sticking the double-sided tape to the entire surface 11b. .

[Embodiment 2]
The second embodiment of the present invention will be described below with reference to FIG. FIG. 2 is a schematic cross-sectional view showing a gasket 10A according to Embodiment 2 of the present invention. The gasket 10 </ b> A is different from the gasket 10 in that the conductive layer 3 is provided around the core material 1, and the others are the same. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

[Gasket structure]
The structure of the gasket 10A will be described below with reference to FIG. As shown in FIG. 2, the gasket 10 </ b> A includes a core material 1 and a conductive layer 3. The core material 1 is composed of a magnetic material 2. The conductive layer 3 is for establishing electrical connection between the metal plate 50a and the metal plate 50b. The conductive layer 3 is formed around the core material 1, that is, the magnetic material 2. In the present embodiment, the conductive layer 3 is formed on all surfaces except one surface other than the surface facing the metal plates 50a and 50b of the core material 1 and the surface facing the one surface. Not limited to. The conductive layer 3 only needs to be formed so as to connect both ends of the core material 1 on the metal plate 50a side and the metal plate 50b side, and it is only necessary that the metal plate 50a and the metal plate 50b can conduct each other.

  In the present embodiment, the conductive layer 3 has a conductive thin film formed on a non-metallic substrate. As the substrate, not only a polymer film including a PET (polyethylene terephthalate) film and a polyimide resin film but also a cloth woven with fibers can be used. Further, as the conductive thin film, copper foil, Ni (nickel) foil, gold foil, and aluminum foil generated by plating, etching, or the like can be used. As another method of forming the conductive layer 3, plating (copper, nickel, gold, etc.) is formed on the surface of the core material 1, or a conductive pattern is formed by a printing technique using a conductive paint. The conductive layer 3 may be formed.

  The conductive layer 3 is preferably thin, but preferably has a thickness that does not break even when the metal plates 50a and 50b are attracted to the gasket 10A.

[Gasket manufacturing method]
A method for manufacturing the gasket 10A will be described below. The core material 1 is formed by cutting a rectangular magnetic material 2 having a predetermined thickness into a required width. Thereafter, the conductive layer 3 is formed around the core material 1. The conductive layer 3 is formed by, for example, winding a sheet-like conductive material around the core material 1 and bonding it. As a specific example of the bonding method, a thermosetting adhesive is applied to one end of a sheet-like conductive material, the conductive material is wound around the core material 1, and then the portion where the adhesive is applied is heated. . Thereby, the both ends of an electrically-conductive material are adhere | attached in the state which covered the core material 1. FIG.

  Another method for forming the conductive layer 3 is to apply a thermosetting adhesive on the entire inner surface (side facing the core material 1) or at least a part of the sheet-like conductive material, After winding around the core material 1, the whole is heated. Thereby, the core material 1 and the conductive material are bonded.

  The core material 1 on which the conductive layer 3 is formed is cut according to the required depth. The width and depth to be cut are appropriately changed according to the gap between the metal plates 50a and 50b that conduct each other.

[Conduction of metal plate]
The mutual conduction | electrical_connection of the metal plates 50a and 50b in the gasket 10A is demonstrated below based on FIG. Since the conductive layer 3 is formed around the core material 1, the metal plates 50 a and 50 b can be electrically connected to each other through the conductive layer 3. Therefore, the metal plates 50a and 50b can be stably connected to each other regardless of the resistance value of the magnetic material 2.

[Modification of Embodiment 2]
A modification of the second embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a schematic cross-sectional view showing a gasket 10B according to a modification of the second embodiment of the present invention. The gasket 10B is different from the gasket 10A in that the magnetic material 2 has a cavity 4 inside, and the others are the same. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

[Gasket structure]
The structure of the gasket 10B will be described below based on FIG. As shown in FIG. 3, the gasket 10 </ b> B includes a core material 1 </ b> B and a conductive layer 3. The core material 1B is composed of a magnetic material 2, and the magnetic material 2 further has a cavity 4 in the center of the inside.

  The cavity 4 can be deformed and allows elastic deformation of the magnetic material 2. Specifically, for example, when the metal plates 50a and 50b are attracted perpendicular to the gasket 10B, the cavity 4 is compressed in a direction in which the metal plates 50a and 50b face each other. Further, when an external force is applied so as to press the metal plates 50a and 50b obliquely (in a direction other than the vertical direction) against the gasket 10B, the periphery of the cavity 4 is deformed so as to crush the cavity 4. Therefore, by providing the cavity 4 inside the magnetic material 2, the cavity 4 exhibits cushioning properties against the magnetic material 2, and the magnetic material 2 is in the height direction (the direction in which the metal plate 50a and the metal plate 50b face each other). ), For example, can also be deformed in the width direction (direction perpendicular to the height direction) and the depth direction (direction perpendicular to the height direction and the width direction). As a result, since the gasket 10B has flexibility at least in the height direction, the gasket 10B can have an allowance for a dimensional deviation in the height direction of the gasket 10B. Here, the dimension deviation indicates a deviation due to manufacturing tolerances of the gasket 10B and the like. Further, even when the metal plates 50a and 50b are obliquely pressed against the gasket 10B, the gasket 10B has flexibility in the width direction and the depth direction, so the dimensions on the metal plates 50a and 50b. It can have tolerance for deviation.

  For the magnetic material 2, it is desirable to use a flexible magnetic material 2 such as a magnet sheet in which a magnetic material is mixed with a flexible synthetic rubber to form a plate. Since the magnetic material 2 has flexibility, the flexibility of the gasket 10B is further increased.

[Gasket manufacturing method]
An example of a method for manufacturing the gasket 10B will be described below. First, the magnetic material 2 is formed with a predetermined thickness around a rod-shaped jig, and the magnetic material 2 is cured by heating or the like. After the magnetic material 2 is cured, the jig is extracted from the magnetic material 2. Thereby, the magnetic material 2 (core material 1B) which has a cavity in the center is formed. Thereafter, the conductive layer 3 is formed around the core material 1B, and the core material 1B on which the conductive layer 3 is formed is cut according to the gap between the metal plates 50a and 50b.

  Another example of a method for forming a cavity in the magnetic material 2 will be described below. First, the magnetic material 2 is formed with a predetermined thickness around a member having a low melting point such as a resin. Further, a sheet-like conductive material is wound around the magnetic material 2. Thereafter, by heating to bond the sheet-like conductive material, the member having a low melting point covered with the magnetic material 2 melts and flows due to the heating, so that a space can be created inside the magnetic material 2. . Further, the cavity 4 may be formed in the magnetic material 2 using a mold.

  Furthermore, also in the gasket 10 according to the first embodiment, a cavity can be provided in the magnetic material 2 to make the gasket 10 flexible. In addition, in the gasket 10 according to the first embodiment, when a plastic magnet having conductivity is adopted as the magnetic material 2, the plastic magnet has flexibility, so that the gasket 10 can be provided without providing a cavity in the magnetic material 2. Can be made flexible.

[Embodiment 3]
Embodiment 3 of the present invention will be described below with reference to FIG. The gasket 10 </ b> C is different from the gasket 10 in that the core material 1 </ b> C further includes an elastic layer 5, and the conductive layer 3 is provided around the core material 1 </ b> C. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

[Gasket structure]
The structure of the gasket 10C will be described below with reference to FIG. FIG. 4A is a schematic cross-sectional view showing a gasket 10C according to Embodiment 3 of the present invention. As shown in FIG. 4A, the gasket 10 </ b> C includes a core material 1 </ b> C and a conductive layer 3. The core material 1 </ b> C includes a magnetic material 2 and an elastic layer 5. The conductive layer 3 is formed around the core material 1C.

  The elastic layer 5 is formed around the magnetic material 2, that is, between the magnetic material 2 and the conductive layer 3. The elastic modulus of the elastic layer 5 is smaller than the elastic modulus of the magnetic material 2. Therefore, the elastic layer 5 allows elastic deformation of the core material 1C. The elastic layer 5 has the same cushioning property as the cavity 4 described above. Therefore, the gasket 10C has flexibility in the height direction and other directions, similarly to the gasket 10B, and therefore can have tolerance for dimensional deviation in the height direction and other directions. As a material of the elastic layer 5, a polyurethane foam, a polyethylene foam, a rubber foam, or the like can be used. Specifically, foamed materials such as NBR latex sponge, SBR latex sponge, and polyolefin can be used. Rubber may also be used.

  In the present embodiment, the elastic layer 5 is formed around the magnetic material 2, but is not limited thereto. It suffices that at least a part of the core material 1 </ b> C includes the elastic layer 5 having an elastic modulus smaller than that of the magnetic material 2. For example, the elastic layer 5 is provided on the metal plate 50 a side and the metal plate 50 b side of the magnetic material 2. You may form in one or both of both surfaces.

[Gasket manufacturing method]
An example of a method for manufacturing the gasket 10C will be described below. First, the rectangular magnetic material 2 having a predetermined thickness is cut into a necessary width. Next, the elastic layer 5 having a predetermined thickness is wound around the magnetic material 2 to form the core material 1C. For example, the elastic layer 5 may be formed by bonding a sheet-like foam material around the magnetic material 2 with an adhesive. Thereafter, the conductive layer 3 is formed around the core material 1C, and the core material 1C on which the conductive layer 3 is formed is cut according to the gap between the metal plates 50a and 50b.

[Suppression of metal plate distortion]
The suppression of the distortion of the metal plates 50a and 50b will be described below with reference to FIG. FIG. 4B is a diagram illustrating a state where the metal plates 50a and 50b are attracted to the gasket 10C. When the metal plates 50a and 50b are attracted by the magnetic force of the gasket 10C, as shown in FIG. 4B, the metal plates 50a and 50b are attracted to the gasket 10C by the drag 31 due to the cushioning property of the elastic layer 5 provided in the core material 1C. Pushed back. However, in the gasket 10C, as shown in FIG. 4B, the drag 31 and the suction force 30 that attracts the metal plates 50a and 50b to the magnetic material 2 are equal, and the gasket 10C of the metal plates 50a and 50b No external force is applied to the surrounding area. Therefore, even if the drag 31 is generated by the metal plates 50a and 50b being attracted to the gasket 10C, the metal plates 50a and 50b are not distorted to the outside of the gasket 10C. As a result, the gasket 10C can suppress the metal plates 50a and 50b from being distorted to the outside of the gasket 10C.

[Modification of Embodiment 3]
A modification of the third embodiment of the present invention is described below with reference to FIG. FIG. 5 is a schematic cross-sectional view showing a gasket 10D according to a modification of the third embodiment of the present invention. The gasket 10D is different from the gasket 10C in that two layers of the magnetic material 2 and the elastic layer 6 are provided between the two layers of the magnetic material 2, and the others are the same. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

[Gasket structure]
The structure of the gasket 10D will be described below with reference to FIG. As shown in FIG. 5, the gasket 10 </ b> D includes a core material 1 </ b> D and a conductive layer 3. The core material 1 </ b> D is composed of two layers of magnetic material 2 and an elastic layer 6. The conductive layer 3 is formed around the core material 1D.

  The magnetic material 2 has two layers in a direction in which the metal plate 50a or the metal plate 50b extends (a direction parallel to the in-plane direction), and the two layers are laminated along a direction in which the metal plate 50a and the metal plate 50b face each other. The elastic layer 6 is formed between the two magnetic materials 2. The elastic modulus of the elastic layer 6 is smaller than the elastic modulus of the magnetic material 2. Therefore, the elastic layer 6 allows elastic deformation of the core material 1D. As in the third embodiment, the core material 1D is provided with an elastic layer 6 having a smaller elastic modulus than the magnetic material 2 between the magnetic materials 2, so that the elastic layer 6 exhibits cushioning properties with respect to the core material 1D. The core material 1D can be deformed in the width direction and the depth direction, for example, in addition to the height direction. As a result, since the gasket 10D has flexibility at least in the height direction, the gasket 10D can have tolerance for dimensional deviation in the height direction. Moreover, since it has flexibility also in the width direction and the depth direction, it can have tolerance to the dimensional deviation on the metal plates 50a and 50b. Furthermore, since the elastic layer 6 is not provided between the conductive layer 3 and the magnetic material 2 as in the gasket 10C, the attractive force 30 that attracts the metal plates 50a and 50b is more strongly maintained. As the material of the elastic layer 6 of this modification, the same material as that of the elastic layer 5 described in the third embodiment can be used.

[Gasket manufacturing method]
An example of a method for manufacturing the gasket 10D will be described below. First, the magnetic material 2 having a predetermined thickness is bonded to both surfaces of the elastic layer 6 having a predetermined thickness with an adhesive or the like to form the core material 1D. Thereafter, the conductive layer 3 is formed around the layered core material 1D, and the core material 1D on which the conductive layer 3 is formed is cut according to the gap between the metal plates 50a and 50b.

[Example of application to circuit board laminates]
An application example of the gasket 10 according to the first embodiment to the circuit board laminate 20 will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those described in the above embodiment and processes similar to those described in the above embodiment are denoted by the same reference numerals as those in the above embodiment. Is omitted. In addition, although only the gasket 10 will be described in this application example, the same applies to the gaskets 10A, 10B, 10C, and 10D.

  The circuit board laminate 20 of this application example includes the gasket 10 shown in FIG. FIG. 6 shows an exploded circuit board laminate 20. As shown in the figure, the circuit board laminate 20 includes a main board 7a that is one circuit board, a board holder 8, a gasket 10, and a sub board 7b that is the other circuit board. The substrate holder 8 is provided with a gasket installation portion 9 for installing a gasket. Here, in the laminate 20 of circuit boards, the main board 7a and the sub board 7b are a pair of circuit boards that are stacked (assembled) with each other. The metal plate 50a shown in the first embodiment is a constituent member of the main board 7a, and the metal plate 50b is a constituent member of the sub board 7b. The main board 7a and the sub board 7b are stacked on each other with the gasket 10 sandwiched between the metal plates 50a and 50b.

  7 to 9 show the process of assembling the circuit board laminate 20. When assembling the laminate 20 of circuit boards, as shown in FIG. 7, first, the board holder 8 is mounted on the main board 7a. Further, as shown in FIG. 8, a gasket 10 is fitted in the gasket installation portion 9. Finally, as shown in FIG. 9, the sub-board 7b is mounted on the board holder 8, and the circuit board laminate 20 is completed. In the circuit board laminate 20, the metal plates 50 a and 50 b are not distorted even when the metal plates 50 a and 50 b in the main board 7 a and the sub board 7 b are electrically connected to each other. Therefore, it is possible to manufacture the circuit board laminate 20 in which the problem due to the distortion does not occur.

  The gasket 10 is suitable for use in a mobile phone, but can also be applied to electronic devices such as notebook PCs, liquid crystal displays, car navigation systems, and hard disks. Further, if the electronic device is provided with the gasket 10, the metal plate 50a, 50b is not distorted when the metal plates 50a, 50b are electrically connected to each other through the gasket 10, similarly to the laminate 20 of the circuit board. It is possible to provide an electronic device capable of preventing the occurrence of the problem due to the distortion. The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

[Summary]
The gasket (10, 10A, 10B, 10C, 10D) according to the first aspect of the present invention is sandwiched between the first conductor (metal plate 50a) and the second conductor (metal plate 50b) that are electrically conductive. In the gasket for electrically connecting the first conductor and the second conductor to each other, at least a part of the gasket is formed of a magnetic material (2) having a magnet property, and the magnetic material is formed of the first conductor and the second conductor. Has magnetic force to attract two conductors.

  According to the said structure, it forms with the magnetic material (2) which has the property of the magnet which can attract a 1st conductor and a 2nd conductor to at least one part of a gasket. Therefore, when the gasket is sandwiched between the first conductor and the second conductor, the first conductor and the second conductor are attracted to the gasket side by the attractive force due to the magnetic force. By this suction force, the contact pressure between the gasket and the first conductor and the second conductor can be sufficiently increased. As a result, since the contact resistance at the contact surface between the first conductor and the second conductor and the gasket can be reduced, the mutual conduction between the first conductor and the second conductor can be stably secured. In addition, since the mutual conduction between the first conductor and the second conductor can be stably ensured without pressing the first conductor and the second conductor against the gasket, the gasket attaches the first conductor and the second conductor to the gasket. It is possible to suppress distortion (bulge) of the first conductor and the second conductor that occurs when pressed against the first conductor. As a result, it is possible to prevent the occurrence of problems due to the distortion of the first conductor and the second conductor.

  In addition, since the first conductor and the second conductor can be attracted to the gasket, the gasket is fixed to the first conductor and the second conductor without using an adhesive or the like only by sandwiching the gasket between the first conductor and the second conductor. can do.

  The gasket (10A, 10B, 10C, 10D) according to aspect 2 of the present invention is the above-described aspect 1, and the magnetic material (2) is included in the core material (1 · 1B · 1C · 1D) constituting the gasket. The core material is sandwiched between the first conductor (metal plate 50a) and the second conductor (metal plate 50b), and both ends of the core material on the first conductor side and the second conductor side. You may provide the conductive layer (3) which connected the part.

  According to the above configuration, since the gasket is provided with the conductive layer that connects both the first conductor side and the second conductor side of the core material including the magnetic material, the first conductor and the second conductor are provided. Can be conducted to each other through a conductive layer. Therefore, the first conductor and the second conductor can be stably conducted to each other regardless of the resistance values of the magnetic material and the core material.

  The gasket (10B, 10C, 10D) according to aspect 3 of the present invention is the above aspect 1 or 2, wherein at least the first conductor (metal plate 50a) and the second conductor (metal plate 50b) face each other. You may have flexibility.

  According to the above configuration, since the gasket has flexibility in a direction in which at least the first conductor and the second conductor face each other, the direction in which the first conductor and the second conductor face each other is determined by the gasket. In the case of the height direction, the gasket can be deformed in the height direction. Therefore, the gasket can have at least tolerance for a dimensional deviation in the height direction. Further, even when an external force is applied such that the first conductor and the second conductor are obliquely pressed against the gasket, the gasket has flexibility in directions other than the height direction. In some cases, it can have tolerance for dimensional deviations in directions other than the height direction.

  The gasket (10B) according to aspect 4 of the present invention is the above aspect 3, wherein the magnetic material (2) may have a cavity (4) formed therein.

  According to the above configuration, the cavity formed in the magnetic material allows elastic deformation of the magnetic material. Specifically, when the gasket attracts the first conductor and the second conductor by magnetic force, at least the cavity is compressed in the direction in which the first conductor and the second conductor face each other. In other words, when the direction in which the first conductor and the second conductor face each other is the height direction of the gasket, the gasket can be deformed at least in the height direction. Thereby, the gasket can have the tolerance with respect to the dimension shift | offset | difference of a height direction at least.

  In the gasket (10C) according to the fifth aspect of the present invention, in the second aspect, the core material (1C) may include an elastic layer (5) having a smaller elastic modulus than the magnetic material (2).

  The gasket (10C) according to the third aspect is characterized in that the magnetic material (2) includes at least the first conductor (metal plate 50a) and the second conductor (metal plate 50b) in the periphery of the magnetic material. An elastic layer (5) having an elastic modulus smaller than that of the magnetic material may be provided on the surface facing one of the above.

  According to the above configuration, the elastic layer having a smaller elastic modulus than the magnetic material formed on the core material allows elastic deformation of the gasket. In addition, an elastic layer having an elastic modulus smaller than that of the magnetic material formed on at least one surface of the periphery of the magnetic material facing the first conductor and the second conductor allows elastic deformation of the gasket. Specifically, when the first conductor and the second conductor are attracted to the gasket, the elastic layer is compressed at least in the direction in which the first conductor and the second conductor face each other. In other words, when the direction in which the first conductor and the second conductor face each other is the height direction of the gasket, the gasket can be deformed at least in the height direction. Thereby, the gasket can have the tolerance with respect to the dimension shift | offset | difference of a height direction at least.

  The gasket (10D) according to aspect 6 of the present invention is the above-described magnetic material (10D) according to the aspect 3 described above along the direction in which the first conductor (metal plate 50a) and the second conductor (metal plate 50b) face each other. 2) may be laminated in two layers, and an elastic layer (6) having an elastic modulus smaller than that of the magnetic material may be provided between the magnetic materials of the two layers.

  According to the above configuration, the elastic layer having an elastic modulus smaller than that of the magnetic material formed between the two layers of the magnetic material allows elastic deformation of the gasket. Specifically, when the first conductor and the second conductor are attracted to the gasket, the elastic layer is compressed at least in the direction in which the first conductor and the second conductor face each other. In other words, when the direction in which the first conductor and the second conductor face each other is the height direction of the gasket, the gasket can be deformed at least in the height direction. Thereby, the gasket can have the tolerance with respect to the dimension shift | offset | difference of a height direction at least. Further, since there is no elastic layer between the conductive layer and the magnetic material, the attractive force that attracts the first conductor and the second conductor to the gasket is maintained.

  In the laminated body (20) of the circuit board according to the seventh aspect of the present invention, the first conductor (metal plate 50a) and the second conductor (metal plate 50b) are as described in any one of the first to sixth aspects. It is a component of a pair of circuit boards (main board 7a, sub-board 7b) that are stacked on each other with a gasket (10, 10A, 10B, 10C, 10D) sandwiched between them, and includes at least one pair of the circuit boards. Also good.

  Moreover, the electronic device which concerns on aspect 8 of this invention may be provided with the gasket (10 * 10A * 10B * 10C * 10D) in any one of the said aspects 1-6.

  According to the said structure, since the said gasket is used, the laminated body of a circuit board and electronic device which show an effect similar to the aspect 1 can be provided.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used in the gasket of the present invention, and circuit board laminates and electronic devices using the gasket.

  1 · 1B · 1C · 1D Core material, 2 Magnetic material, 3 Conductive layer, 4 Cavity, 5 · 6 Elastic layer, 7a Main board (circuit board), 7b Sub board (circuit board), 10 · 10A · 10B · 10C 10D gasket, 20 laminate, 50a metal plate (first conductor), 50b metal plate (second conductor)

Claims (6)

In the gasket for electrically connecting the first conductor and the second conductor by being sandwiched between the first conductor and the second conductor that are electrically conductive,
At least a part of the gasket is formed of a magnetic material having the properties of a magnet,
The magnetic material is included in a core material constituting the gasket,
The core material is sandwiched between the first conductor and the second conductor,
A conductive layer connecting both ends of the core material on the first conductor side and the second conductor side;
The gasket, wherein the magnetic material has a magnetic force to attract the first conductor and the second conductor. The gasket according to claim 1, wherein the gasket has flexibility in a direction in which at least the first conductor and the second conductor face each other. The gasket according to claim 2 , wherein the magnetic material has a cavity formed therein. The gasket according to claim 1 , wherein the core material includes an elastic layer having a smaller elastic modulus than the magnetic material. The first conductor and the second conductor are constituent members of a pair of circuit boards that are stacked on each other with the gasket according to any one of claims 1 to 4 interposed therebetween,
A laminate of circuit boards, comprising at least a pair of the pair of circuit boards. An electronic apparatus comprising the gasket according to any one of claims 1 to 4 .

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