JP6878142B2 - Electronics - Google Patents

Description

The present invention relates to electronic devices.

As a method of suppressing electromagnetic wave noise radiated from the outside world, there is a method of shielding electromagnetic wave noise by installing a metal plate facing a printed circuit board mounted on an electronic device. Further, as a countermeasure against electrostatic noise, there is a method of providing a metal frame (shell) in the connector for external connection of the electronic device.

When both the metal plate and the shell are connected to the ground, a large electric charge such as electrostatic noise applied to the shell also flows toward the metal plate. When the electric charge generated on the metal plate is electrostatically coupled to the integrated circuit on the printed circuit board, the integrated circuit may malfunction. In the technique described in Japanese Patent Application Laid-Open No. 2012-94897 (Patent Document 1), a hole is provided in a portion of a metal plate facing the integrated circuit. As a result, the electrostatic coupling between the integrated circuit and the metal plate is weakened, and the malfunction of the integrated circuit is suppressed.

Japanese Unexamined Patent Publication No. 2012-94897

However, in the technique described in Japanese Patent Application Laid-Open No. 2012-94897, since the metal plate facing the integrated circuit is provided with a hole, the influence of electrostatic noise is suppressed to some extent, but electromagnetic noise on the integrated circuit is suppressed. The effect of shielding is weakened. As a result, the influence of electromagnetic noise radiated from the outside world on the integrated circuit cannot be suppressed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an electronic device capable of suppressing the influence of electrostatic noise while blocking electromagnetic waves radiated from the outside world. is there.

The electronic device according to the present invention includes a printed circuit board, a metal frame, a first metal plate portion, and a second metal plate portion. The printed circuit board is provided with an integrated circuit and a connector for external connection. The metal frame covers the connector for external connection. The first metal plate portion covers the integrated circuit and faces at least a part of the printed circuit board. The second metal plate portion is electrically connected to the metal frame and extends in a direction perpendicular to the printed circuit board. Both the first metal plate portion and the second metal plate portion are configured to be electrically connectable to the frame ground. The printed circuit board is provided with a signal ground connected to the integrated circuit. The distance between the signal ground and the second metal plate portion in the direction parallel to the printed circuit board is equal to or greater than the distance between the signal ground and the first metal plate portion in the direction perpendicular to the printed circuit board.

According to the electronic device according to the present invention, it is possible to provide an electronic device capable of suppressing the influence of electrostatic noise while blocking electromagnetic waves radiated from the outside world.

It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 1. FIG. It is a plan schematic diagram which shows the structure of the electronic device which concerns on Embodiment 1. FIG. It is a schematic view of the end face of the cut portion along the line III-III of FIG. It is a schematic view of the end face of the cut portion along the line IV-IV of FIG. It is a figure which shows the relationship between the electric field strength and the distance in the near field. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 2. FIG. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 3. FIG. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 4. FIG. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 5. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 6. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 7. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 8. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 9. FIG. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 10. It is an exploded perspective schematic diagram which shows the structure of the electronic device which concerns on Embodiment 11. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings below, the same or corresponding parts are given the same reference numbers, and the explanations are not repeated.

(Embodiment 1)
First, the configuration of the electronic device 100 according to the first embodiment of the present invention will be described.

As shown in FIGS. 1 and 2, the electronic device 100 according to the first embodiment includes a printed circuit board 1, an integrated circuit 10, an external connection connector 2, a metal frame 9, a signal ground 6, and the like. It mainly has a first metal plate portion 3, a second metal plate portion 4, and an earth pattern 5. The integrated circuit 10, the signal ground 6, the external connection connector 2, and the ground pattern 5 are provided on the printed circuit board 1. The signal ground 6 is provided near the center of the printed circuit board 1. The integrated circuit 10 is electrically connected to the signal ground 6. The integrated circuit 10 is provided on the signal ground 6. The external connection connector 2 is provided, for example, near the end of the printed circuit board 1. The ground pattern 5 is provided near the corners of the printed circuit board 1, for example.

As shown in FIG. 2, the outer shape of the printed circuit board 1 is, for example, a quadrangle in a plan view (a field of view viewed from a direction perpendicular to the printed circuit board 1). The printed circuit board 1 has a first side portion 1a, a second side portion 1b, a third side portion 1c, and a fourth side portion 1d. The first side portion 1a faces the third side portion 1c. The second side portion 1b faces the fourth side portion 1d. The first side portion 1a is connected to the second side portion 1b. The second side portion 1b is connected to the third side portion 1c. The third side portion 1c is connected to the fourth side portion 1d. The fourth side portion 1d is connected to the first side portion 1a. The first metal plate portion 3 is arranged along each of the third side portion 1c and the fourth side portion 1d, for example. The second metal plate portion 4 is arranged along each of the first side portion 1a and the second side portion 1b, for example. The first metal plate portion 3 is separated from, for example, the second metal plate portion 4. The external connection connector 2 is provided on, for example, the first side portion 1a. The earth pattern 5 is provided at a corner formed by, for example, the second side portion 1b and the third side portion 1c.

As shown in FIG. 2, the first metal plate portion 3 covers the integrated circuit 10. The first metal plate portion 3 faces at least a part of the printed circuit board 1. The first metal plate portion 3 faces at least a part of the signal ground 6. The first metal plate portion 3 may cover the entire signal ground 6. The first metal plate portion 3 covers a part of the earth pattern 5. In other words, in a plan view, a part of the earth pattern 5 is exposed from the first metal plate portion 3. In a plan view, the signal ground 6 is located inside the outer edge of the printed circuit board 1. In other words, the signal ground 6 is separated from each of the first side portion 1a, the second side portion 1b, the third side portion 1c, and the fourth side portion 1d. The signal ground 6 is separated from the metal frame 9. The signal ground 6 is separated from the ground pattern 5. The signal ground 6 is separated from the second metal plate portion 4.

Both the first metal plate portion 3 and the second metal plate portion 4 are configured to be electrically connectable to an external frame ground (not shown). Specifically, the earth pattern 5 is in contact with both the first metal plate portion 3 and the second metal plate portion 4. Both the first metal plate portion 3 and the second metal plate portion 4 are electrically connected to the frame ground via the earth pattern 5. As shown in FIGS. 1 and 2, the second metal plate portion 4 has a first flat plate portion 4a and a second flat plate portion 4b. The first flat plate portion 4a is arranged along the second side. The first flat plate portion 4a has a first connecting portion 4a1 and a first region 4a2. The first connecting portion 4a1 extends along the first region 4a2. The first connection portion 4a1 is electrically connected by being in contact with the ground pattern 5. The first metal plate portion 3 has a third connecting portion 3a and a third flat plate portion 3b. The third connecting portion 3a is bent substantially perpendicular to the third flat plate portion 3b. The third connection portion 3a is electrically conducted by being in contact with the ground pattern 5. Each of the first connecting portion 4a1 and the third connecting portion 3a may be inserted into a hole provided in the ground pattern 5 and connected to the ground pattern 5 by a method such as soldering or screwing. Each of the first connection portion 4a1 and the third connection portion 3a may be pressed against the earth pattern 5 by the leaf spring portions formed in each of the first connection portion 4a1 and the third connection portion 3a.

The second flat plate portion 4b is arranged along the first side portion 1a. The second flat plate portion 4b is connected to the first flat plate portion 4a. The second flat plate portion 4b is bent substantially perpendicular to the first flat plate portion 4a. The second flat plate portion 4b has a second region 4b1, a third region 4b2, and a fourth region 4b3. The second region 4b1 is connected to the first flat plate portion 4a. The third region 4b2 is connected to the second region 4b1. The third region 4b2 is located on the side opposite to the first flat plate portion 4a with respect to the second region 4b1. The fourth region 4b3 is connected to the third region 4b2. The fourth region 4b3 is located on the opposite side of the third region 4b2 from the second region 4b1. The third region 4b2 is located between the second region 4b1 and the fourth region 4b3. The external connection connector 2 is located between the second region 4b1 and the fourth region 4b3 in the direction parallel to the printed circuit board 1. The external connection connector 2 is located between the third region 4b2 and the printed circuit board 1 in the direction perpendicular to the printed circuit board 1.

FIG. 3 is a schematic view of the end face of the cut portion along the line III-III of FIG. As shown in FIG. 3, the metal frame 9 covers the external connection connector 2. The metal frame 9 is provided, for example, in contact with the upper surface and the side surface of the external connection connector 2. The second metal plate portion 4 is electrically connected to the metal frame 9. Specifically, the second metal plate portion 4 has a leaf spring portion formed by, for example, being spring-processed and bent. By pressing the leaf spring portion of the second metal plate portion 4 against the metal frame 9, the second metal plate portion 4 and the metal frame 9 are electrically connected. The leaf spring portion may be in contact with only the upper surface of the metal frame 9, may be in contact with only the side surface, or may be in contact with both the upper surface and the side surface. The tip of the metal frame 9 may be provided so as to penetrate the printed circuit board 1. The tip of the metal frame 9 may be fixed to the printed circuit board 1 by soldering or the like.

FIG. 4 is a schematic view of the end face of the cut portion along the line IV-IV of FIG. As shown in FIG. 4, the second metal plate portion 4 extends in a direction perpendicular to the printed circuit board 1. Here, the direction perpendicular to the printed circuit board 1 may be a direction substantially perpendicular to the printed circuit board 1. That is, the second metal plate portion 4 may be inclined from a direction perpendicular to the printed circuit board 1 by an angle of about a manufacturing error. Considering the manufacturing error, the angle of the second metal plate portion 4 with respect to the printed circuit board 1 may be, for example, about 85 ° or more and about 95 ° or less.

_{As shown in FIG. 4, the distance y 2} between the signal ground 6 and the second metal plate portion 4 in the direction A parallel to the printed circuit board 1 is for the signal in the direction C perpendicular to the printed circuit board 1. The distance between the ground 6 and the first metal plate portion 3 is z or more. _{The distance y 2} between the signal ground 6 and the second metal plate 4 in the direction A parallel to the printed substrate 1 is the second metal from the end of the second metal plate 4 facing the signal ground 6. This is the distance to the end of the signal ground 6 facing the plate 4. Similarly, the distance z between the signal ground 6 and the first metal plate portion 3 in the direction C perpendicular to the printed substrate 1 is the first from the end of the first metal plate portion 3 facing the signal ground 6. 1 The distance to the end of the signal ground 6 facing the metal plate portion 3. _{The distance y 2} between the signal ground 6 and the second metal plate portion 4 in the direction A parallel to the printed substrate 1 is the signal ground 6 and the first metal plate portion 4 in the direction C perpendicular to the printed substrate 1. It may be larger than the distance z with 3.

_{The distance y 2} between the signal ground 6 and the second metal plate 4 in the direction parallel to the printed substrate 1 is the signal ground 6 and the first metal plate 3 in the direction perpendicular to the printed substrate 1. When the distance z is the same, the distance between the upper end portion of the second metal plate portion 4 and the end portion of the signal ground 6 is (y ₂ ² + x ₁ ² ) ^1/2 . This distance is larger than the distance z between the signal ground 6 and the first metal plate portion 3 in the direction perpendicular to the printed circuit board 1. That is, the effective distance between the signal ground 6 and the second metal plate portion 4 is larger than the effective distance between the signal ground 6 and the first metal plate portion 3. The noise radiated by the first metal plate portion 3 and the second metal plate portion 4 can be regarded as a dipole antenna at the open ends of these metal plate portions, so that the electric and magnetic fields in the near field generated by the dipole antenna can be regarded as the dipole antenna. Become. The electric and magnetic fields in the near field are inversely proportional to the cube and square of the distance, respectively. Therefore, the larger the distance z between the signal ground 6 and the first metal plate portion 3 and the distance y ₂ between the signal ground 6 and the second metal plate portion 4, the more the influence of electromagnetic waves on the integrated circuit 10 is suppressed. Can be done.

FIG. 5 is a diagram showing the relationship between the electric field strength and the distance in the near field. Generally, the ground pattern 5 and the signal pattern with the signal ground 6 as the reference ground are divided into a primary side and a secondary side when viewed from the power supply system. In consideration of safety, the space distance between the primary side and the secondary side is generally set to 2 mm or more in a device operating with an AC of 100 V. In FIG. 5, the relationship between the electric field strength and the distance is shown, where 1 is the electric field strength when the space distance between the primary side and the secondary side is 2 mm. As mentioned above, the electric field strength is attenuated in inverse proportion to the cube of the distance. As shown in FIG. 5, in order to make the electric field strength 1/10 or less of the electric field strength when the space distance is 2 mm, it is desirable that the space distance is 5 mm or more. When the earth pattern 5, the first metal plate portion 3 and the second metal plate portion 4 are regarded as the primary side, and the signal ground 6 is regarded as the secondary side, the distance z and the distance from each to the signal ground 6 By _{setting y 2} to 5 mm or more, the influence of the electric field can be further suppressed.

_{As shown in FIGS. 2 and 4, the distance y 2} between the second metal plate portion 4 and the signal ground 6 in the direction A parallel to the first side portion 1a is, for example, 5 mm or more. Similarly, the distance y ₁ of the metal frame 9 and the signal ground 6 in the second side portion 1b in a direction parallel B is, for example 5mm or more. The earth pattern 5 and the signal ground 6 may partially overlap when viewed from the direction A parallel to the first side portion 1a. Distance y ₄ of the ground pattern 5 and the signal ground 6 in a direction parallel A and the first side portion 1a is, for example 5mm or more. Similarly, the earth pattern 5 and the signal ground 6 may partially overlap when viewed from the direction B parallel to the second side portion 1b. Distance y ₃ of the metal frame 9 and the signal ground 6 in the second side portion 1b in a direction parallel B is, for example 5mm or more.

The second metal plate portion 4 mainly has a function of bypassing the electrostatic noise applied to the external connection connector 2 to the ground. From the viewpoint of suppressing the resonance of the electrostatic noise applied to the second metal plate portion 4, it is desirable to set the length of the second metal plate portion 4 as follows. The maximum frequency of static electricity is, for example, 700 MHz. _{The wavelength λ 1} of the radio wave having a frequency of 700 MHz is 300 (Mm / s) / 700 (MHz) = about 0.429 (m). When the length of the second metal plate portion 4 _{becomes equal to λ 1/2} , noise is likely to be emitted. Therefore, it is desirable that the length of the second metal plate portion 4 is 0.429 / 2 = less than about 0.2 m. _{Specifically, the length x 1} of the second metal plate portion 4 in the direction C perpendicular to the printed circuit board 1 is, for example, less than 0.2 m (see FIGS. 1 and 4). _{The length x 1} of the second metal plate portion 4 in the direction perpendicular to the printed circuit board 1 may be, for example, less than 0.18 m or less than 0.16 m. The length of the second metal plate portion 4 in the direction perpendicular to the printed circuit board 1 is, for example, the length of the boundary line between the first flat plate portion 4a and the second flat plate portion 4b.

The length of the second metal plate portion 4 in a plane parallel to the printed circuit board 1 is, for example, less than 0.2 m. The length of the second metal plate portion 4 in the plane parallel to the printed circuit board 1 may be, for example, less than 0.18 m or less than 0.16 m. The length of the second metal plate portion 4 in the plane parallel to the printed substrate 1 is, for example, the length x ₂ of the first flat plate portion 4a in the direction parallel to the second side portion 1b, and the first It is the total length of the length _{x 3} of the second flat plate portion 4b in the direction parallel to the side portion 1a (see FIG. 1). As used herein, the term "distance" means the shortest spatial distance between two points. On the other hand, "length" means the shortest distance from one position of a member to another, which is measured along the shape of the surface of the member, and is the shortest spatial distance from one position of the member to another. Distinguished from distance.

Next, the operation and effect of the electronic device 100 according to the first embodiment will be described.
According to the electronic device 100 according to the first embodiment, the first metal plate portion 3 covers the integrated circuit 10. As a result, the first metal plate portion 3 can shield the electromagnetic wave noise and suppress the influence of the electromagnetic wave noise on the integrated circuit. Further, the second metal plate portion 4 is electrically connected to the metal frame 9. Therefore, the electrostatic noise applied to the metal frame 9 provided in the external connection connector 2 can be passed to the ground by the second metal plate portion 4 to bypass the electrostatic noise. Further, the second metal plate portion 4 extends in a direction perpendicular to the printed circuit board 1. Compared with the case where the second metal plate portion 4 faces the printed circuit board 1, when the second metal plate portion 4 extends in the direction perpendicular to the printed circuit board 1, the second metal plate portion 4 extends. The area where the portion 4 faces the signal ground 6 on the printed circuit board 1 becomes smaller. Therefore, it is possible to suppress the influence of electrostatic noise on the integrated circuit 10 via the signal ground 6. Further, the distance between the signal ground 6 and the second metal plate portion 4 in the direction parallel to the printed substrate 1 is the distance between the signal ground 6 and the first metal plate portion 3 in the direction perpendicular to the printed substrate 1. It is more than a distance. As a result, it is possible to further suppress the influence of electrostatic noise on the integrated circuit 10 via the signal ground 6.

Further, according to the electronic device 100 according to the first embodiment, the printed circuit board 1 is provided with an earth pattern 5 in contact with both the first metal plate portion 3 and the second metal plate portion 4. Both the first metal plate portion 3 and the second metal plate portion 4 are electrically connected to the frame ground via the earth pattern 5. As a result, the noise of the first metal plate portion 3 and the second metal plate portion 4 can flow to the frame ground via the earth pattern 5.

Further, according to the electronic device 100 according to the first embodiment, the length of the second metal plate portion 4 in the direction perpendicular to the printed circuit board 1 is less than 0.2 m and parallel to the printed circuit board 1. The length of the second metal plate portion 4 in the plane is less than 0.2 m. This makes it possible to suppress the resonance of electrostatic noise in particular. As a result, by suppressing the influence of electrostatic noise on the integrated circuit 10, it is possible to suppress the occurrence of malfunction of the integrated circuit 10.

Further, according to the electronic device 100 according to the first embodiment, the first metal plate portion 3 is separated from the second metal plate portion 4. As a result, it is possible to suppress the electrostatic noise applied from the external connection connector 2 to the first metal plate portion 3 from flowing to the second metal plate portion 4.

(Embodiment 2)
Next, the configuration of the electronic device 100 according to the second embodiment of the present invention will be described. The electronic device 100 according to the second embodiment is different from the electronic device 100 according to the first embodiment in a configuration in which the first metal plate portion 3 and the second metal plate portion 4 are mainly integrated. Other configurations are substantially the same as those of the electronic device 100 according to the first embodiment. Hereinafter, a configuration different from that of the electronic device 100 according to the first embodiment will be mainly described.

As shown in FIG. 6, in the electronic device 100 according to the second embodiment, the first metal plate portion 3 and the second metal plate portion 4 are integrally configured. The first metal plate portion 3 and the second metal plate portion 4 form a metal body 7. In other words, the first metal plate portion 3 is connected to the second metal plate portion 4. Specifically, the first metal plate portion 3 is connected to both the first flat plate portion 4a and the second flat plate portion 4b. The first metal plate portion 3 may cover the entire printed circuit board 1. When viewed from a direction perpendicular to the printed circuit board 1, the outer shape of the first metal plate portion 3 is, for example, a quadrangle, specifically a rectangle or a square. When the long side and the length of the short side of the outline of the first metal plate portion 3, respectively, and x ₄ and x _5, the length of the diagonal line of the outer shape of the first metal plate 3 x ₆ is, (X 4 ₂ ⁺ X ₅ ² ) It becomes ^1/2.

As described above, from the viewpoint of suppressing the resonance of the electrostatic noise applied to the metal plate portion, it is desirable that the length of the metal plate portion is set to less than half of the wavelength of the maximum frequency of static electricity. Specifically, the length x ₆ diagonal first metal plate portion 3, the sum of the length x ₁ of the second metal plate 4 in the direction perpendicular to the printed circuit board 1, for example less than 0.2m is there. Length x ₆ diagonal first metal plate portion 3, the sum of the length x ₁ of the second metal plate 4 in the direction perpendicular to the printed circuit board 1, for example, may be less than 0.18m , May be less than 0.16 m.

According to the electronic device 100 according to the second embodiment, the first metal plate portion 3 is connected to the second metal plate portion 4. As a result, the first metal plate portion 3 and the second metal plate portion 4 can be integrally formed.

Further, according to the electronic device 100 according to the second embodiment, the outer shape of the first metal plate portion 3 is a quadrangle when viewed from a direction perpendicular to the printed circuit board 1. The total of the diagonal length of the first metal plate portion 3 and the length of the second metal plate portion 4 in the direction perpendicular to the printed circuit board 1 is less than 0.2 m. As a result, it is possible to suppress the resonance of electrostatic noise in the integrated first metal plate portion 3 and the second metal plate portion 4. As a result, by suppressing the influence of electrostatic noise on the integrated circuit 10, it is possible to suppress the occurrence of malfunction of the integrated circuit 10.

(Embodiment 3)
Next, the configuration of the electronic device 100 according to the third embodiment of the present invention will be described. The electronic device 100 according to the third embodiment is different from the electronic device 100 according to the first embodiment in a configuration mainly having a plurality of external connection connectors 2, and the other configurations are carried out. It is almost the same as the electronic device 100 according to the first embodiment. Hereinafter, a configuration different from that of the electronic device 100 according to the first embodiment will be mainly described.

As shown in FIG. 7, the external connection connector 2 of the electronic device 100 according to the third embodiment may have two or more connector portions. The external connection connector 2 has, for example, a first connector portion 2a and a second connector portion 2b. The fourth region 4b3 of the second metal plate portion 4 has a fifth region 4b4, a sixth region 4b5, and a seventh region 4b6. The fifth region 4b4 is connected to the third region 4b2. The sixth region 4b5 is connected to the fifth region 4b4. The sixth region 4b5 is located on the side opposite to the third region 4b2 with respect to the fifth region 4b4. The seventh region 4b6 is connected to the sixth region 4b5. The seventh region 4b6 is located on the opposite side of the sixth region 4b5 from the fifth region 4b4. The sixth region 4b5 is located between the fifth region 4b4 and the seventh region 4b6. The first connector portion 2a is located between the second region 4b1 and the fifth region 4b4 in the direction parallel to the printed circuit board 1. The second connector portion 2b is located between the fifth region 4b4 and the seventh region 4b6 in the direction parallel to the printed circuit board 1. The first connector portion 2a is located between the third region 4b2 and the printed circuit board 1 in the direction perpendicular to the printed circuit board 1. The second connector portion 2b is located between the sixth region 4b5 and the printed circuit board 1 in the direction perpendicular to the printed circuit board 1.

(Embodiment 4)
Next, the configuration of the electronic device 100 according to the fourth embodiment of the present invention will be described. The electronic device 100 according to the fourth embodiment mainly has a configuration in which each of the first metal plate portion 3 and the second metal plate portion 4 has a plurality of connecting portions, and the electronic device 100 according to the first embodiment. The other configurations are substantially the same as those of the electronic device 100 according to the first embodiment. Hereinafter, a configuration different from that of the electronic device 100 according to the first embodiment will be mainly described.

As shown in FIG. 8, in the electronic device 100 according to the fourth embodiment, the ground pattern 5 is provided along each of the second side portion 1b, the third side portion 1c, and the fourth side portion 1d. There is. The first flat plate portion 4a of the second metal plate portion 4 has a first connecting portion 4a1, a first region 4a2, and a second connecting portion 4a3. The second connecting portion 4a3 is separated from the first connecting portion 4a1. The first connection portion 4a1 is in contact with the ground pattern 5 at a corner portion formed by the second side portion 1b and the third side portion 1c. The second connecting portion 4a3 is in contact with the ground pattern 5 at a corner portion formed by the first side portion 1a and the second side portion 1b. Each of the first connecting portion 4a1 and the second connecting portion 4a3 is connected to the first region 4a2. Each of the first connecting portion 4a1 and the second connecting portion 4a3 extends along the first region 4a2. Both the first connecting portion 4a1 and the second connecting portion 4a3 are electrically connected to the frame ground via the ground pattern 5.

The second connection portion 4a3 is located closer to the external connection connector 2 than the first connection portion 4a1. The distance between the second connection portion 4a3 and the external connection connector 2 is shorter than the distance between the first connection portion 4a1 and the external connection connector 2. As described above, from the viewpoint of suppressing the resonance of the electrostatic noise applied to the metal plate portion, it is desirable that the length of the metal plate portion is set to less than half of the wavelength of the maximum frequency of static electricity. _{The length x 2} of the second metal plate portion 4 in the direction from the first connecting portion 4a1 to the second connecting portion 4a3 is, for example, less than 0.2 m. _{The length x 2} of the second metal plate portion 4 in the direction from the first connecting portion 4a1 to the second connecting portion 4a3 may be, for example, less than 0.18 m or less than 0.16 m. _{The length x 31} of the second metal plate portion 4 in the direction from the first connection portion 4a1 to the external connection connector 2 is, for example, less than 0.2 m. _{The length x 31} of the second metal plate portion 4 in the direction from the first connection portion 4a1 to the external connection connector 2 may be, for example, less than 0.18 m or less than 0.16 m.

As shown in FIG. 8, the first metal plate portion 3 has a third flat plate portion 3b, a third connecting portion 3a, a fourth connecting portion 3a2, and a fifth connecting portion 3a3. The fourth connecting portion 3a2 is separated from each of the third connecting portion 3a and the fifth connecting portion 3a3. Each of the third connecting portion 3a, the fourth connecting portion 3a2, and the fifth connecting portion 3a3 is bent substantially perpendicular to the third flat plate portion 3b. The third connection portion 3a is in contact with the ground pattern 5 at a corner portion formed by the second side portion 1b and the third side portion 1c. The fourth connection portion 3a2 is in contact with the ground pattern 5 at a corner portion formed by the third side portion 1c and the fourth side portion 1d. The fifth connection portion 3a3 is in contact with the ground pattern 5 at a corner portion formed by the fourth side portion 1d and the first side portion 1a. Both the third connection portion 3a and the fourth connection portion 3a2 are electrically connected to the frame ground via the ground pattern 5. Similarly, the fifth connection portion 3a3 is electrically connected to the frame ground via the ground pattern 5.

The first metal plate portion 3 mainly has a function of shielding electromagnetic wave noise radiated from the outside world. From the viewpoint of suppressing the resonance of electromagnetic noise radiated from the outside world, it is desirable to set the length of the first metal plate portion 3 as follows. The maximum frequency of radiated emissions is, for example, 1 GHz. _{The wavelength λ 2} of the radio wave having a frequency of 1 GHz is 300 (Mm / s) / 1000 (MHz) = 0.3 (m). The length of the first metal plate portion 3, becomes equal to lambda _2/2, the noise is likely to be emitted. Therefore, it is desirable that the length of the first metal plate portion 3 is less than 0.3 / 2 = 0.15 m. _{Specifically, the length x 4} of the first metal plate portion 3 in the direction from the third connecting portion 3a to the fourth connecting portion 3a2 is, for example, less than 0.15 m. _{The length x 4} of the first metal plate portion 3 in the direction from the third connecting portion 3a to the fourth connecting portion 3a2 may be, for example, less than 0.135 m, or may be, for example, less than 0.12 m. .. _{Similarly, the length x 5} of the first metal plate portion 3 in the direction from the fourth connecting portion 3a2 to the fifth connecting portion 3a3 is, for example, less than 0.15 m. _{The length x 5} of the first metal plate portion 3 in the direction from the fourth connecting portion 3a2 to the fifth connecting portion 3a3 may be, for example, less than 0.135 m, or may be, for example, less than 0.12 m. ..

According to the electronic device 100 according to the fourth embodiment, the second metal plate portion 4 includes a first connecting portion 4a1 and a second connecting portion 4a3 separated from the first connecting portion 4a1. Both the first connecting portion 4a1 and the second connecting portion 4a3 are electrically connected to the frame ground. The length of the second metal plate portion 4 in the direction from the first connecting portion 4a1 to the second connecting portion 4a3 is less than 0.2 m. As a result, the resonance of electrostatic noise can be further suppressed.

Further, according to the electronic device 100 according to the fourth embodiment, the second connection portion 4a3 is located closer to the external connection connector 2 than the first connection portion 4a1. The length of the second metal plate portion 4 in the direction from the first connection portion 4a1 to the external connection connector 2 is less than 0.2 m. As a result, the resonance of electrostatic noise can be further suppressed.

Further, according to the electronic device 100 according to the fourth embodiment, the first metal plate portion 3 includes a third connecting portion 3a and a fourth connecting portion 3a2 separated from the third connecting portion 3a. Both the third connecting portion 3a and the fourth connecting portion 3a2 are electrically connected to the frame ground. The length of the first metal plate portion 3 in the direction from the third connecting portion 3a to the fourth connecting portion 3a2 is less than 0.15 m. This makes it possible to suppress the resonance of electromagnetic noise radiated from the outside world. As a result, the influence of electromagnetic noise on the integrated circuit 10 can be reduced.

(Embodiment 5)
Next, the configuration of the electronic device 100 according to the fifth embodiment of the present invention will be described. The electronic device 100 according to the fifth embodiment mainly has a configuration in which the first metal plate portion 3 and the second metal plate portion 4 are directly connected to the frame ground 8 without passing through the earth pattern 5. It is different from the electronic device 100 according to the above, and other configurations are substantially the same as the electronic device 100 according to the first embodiment. Hereinafter, a configuration different from that of the electronic device 100 according to the first embodiment will be mainly described.

As shown in FIG. 9, the electronic device 100 according to the fifth embodiment has a frame ground 8. The frame ground 8 is, for example, a metal housing of the electronic device 100 itself. As shown in FIG. 9, the frame ground 8 may be a board-shaped metal housing on which an electronic device 100 such as a printed circuit board 1 is mounted. The frame ground 8 supports, for example, the printed circuit board 1. The frame ground 8 may be located on the opposite side of the printed circuit board 1 from the signal ground 6. The ground pattern 5 is not provided on the printed circuit board 1. The third connection portion 3a of the first metal plate portion 3 is directly connected to the frame ground 8 without passing through the ground pattern 5. The first metal plate portion 3 may be supported by the frame ground 8. Similarly, the first connecting portion 4a1 of the second metal plate portion 4 is directly connected to the frame ground 8 without passing through the ground pattern 5. The second metal plate portion 4 may be supported by the frame ground 8.

(Embodiment 6)
Next, the configuration of the electronic device 100 according to the sixth embodiment of the present invention will be described. The electronic device 100 according to the sixth embodiment has a structure in which the characteristics of the electronic device 100 according to the third embodiment are applied to the electronic device 100 according to the second embodiment.

As shown in FIG. 10, in the electronic device 100 according to the sixth embodiment, the first metal plate portion 3 and the second metal plate portion 4 are integrally configured. In other words, the first metal plate portion 3 is connected to the second metal plate portion 4. Specifically, the first metal plate portion 3 is connected to both the first flat plate portion 4a and the second flat plate portion 4b. The first metal plate portion 3 may cover the entire printed circuit board 1. When viewed from a direction perpendicular to the printed circuit board 1, the outer shape of the first metal plate portion 3 is, for example, a quadrangle, specifically a rectangle or a square. When the short side and the length of the long side of the outer shape of the first metal plate portion 3, respectively, and x ₄ and x _5, the length of the diagonal line of the outer shape of the first metal plate 3 x ₆ is, (X 4 ₂ ⁺ X ₅ ² ) It becomes ^1/2. The total of the diagonal length of the first metal plate portion 3 and the length of the second metal plate portion 4 in the direction perpendicular to the printed circuit board 1 is, for example, less than 0.2 m.

As shown in FIG. 10, the external connection connector 2 of the electronic device 100 according to the sixth embodiment may have two or more connector portions. The external connection connector 2 has, for example, a first connector portion 2a and a second connector portion 2b. The fourth region 4b3 has a fifth region 4b4, a sixth region 4b5, and a seventh region 4b6. The fifth region 4b4 is connected to the third region 4b2. The sixth region 4b5 is connected to the fifth region 4b4. The sixth region 4b5 is located on the side opposite to the third region 4b2 with respect to the fifth region 4b4. The seventh region 4b6 is connected to the sixth region 4b5. The seventh region 4b6 is located on the opposite side of the sixth region 4b5 from the fifth region 4b4. The sixth region 4b5 is located between the fifth region 4b4 and the seventh region 4b6. The first connector portion 2a is located between the second region 4b1 and the fifth region 4b4 in the direction parallel to the printed circuit board 1. The second connector portion 2b is located between the fifth region 4b4 and the seventh region 4b6 in the direction parallel to the printed circuit board 1. The first connector portion 2a is located between the third region 4b2 and the printed circuit board 1 in the direction perpendicular to the printed circuit board 1. The second connector portion 2b is located between the sixth region 4b5 and the printed circuit board 1 in the direction perpendicular to the printed circuit board 1.

(Embodiment 7)
Next, the configuration of the electronic device 100 according to the seventh embodiment of the present invention will be described. The electronic device 100 according to the seventh embodiment has a structure in which the characteristics of the electronic device 100 according to the fourth embodiment are applied to the electronic device 100 according to the second embodiment.

As shown in FIG. 11, in the electronic device 100 according to the seventh embodiment, the ground pattern 5 is provided along each of the second side portion 1b, the third side portion 1c, and the fourth side portion 1d. There is. The first flat plate portion 4a of the second metal plate portion 4 has a first connecting portion 4a1, a first region 4a2, and a second connecting portion 4a3. The second connecting portion 4a3 is separated from the first connecting portion 4a1. The first connection portion 4a1 is in contact with the ground pattern 5 at a corner portion formed by the second side portion 1b and the third side portion 1c. The second connecting portion 4a3 is in contact with the ground pattern 5 at a corner portion formed by the first side portion 1a and the second side portion 1b. Each of the first connecting portion 4a1 and the second connecting portion 4a3 is connected to the first region 4a2. Each of the first connecting portion 4a1 and the second connecting portion 4a3 extends along the first region 4a2. Both the first connecting portion 4a1 and the second connecting portion 4a3 are electrically connected to the frame ground via the ground pattern 5.

The second connection portion 4a3 is located closer to the external connection connector 2 than the first connection portion 4a1. The distance between the second connection portion 4a3 and the external connection connector 2 is shorter than the distance between the first connection portion 4a1 and the external connection connector 2. As described above, from the viewpoint of suppressing the resonance of the electrostatic noise applied to the metal plate portion, it is desirable that the length of the metal plate portion is set to less than half of the wavelength of the maximum frequency of static electricity. _{The length x 2} of the second metal plate portion 4 in the direction from the first connecting portion 4a1 to the second connecting portion 4a3 is, for example, less than 0.2 m. _{The length x 2} of the second metal plate portion 4 in the direction from the first connecting portion 4a1 to the second connecting portion 4a3 may be, for example, less than 0.18 m or less than 0.16 m. _{The length x 31} of the second metal plate portion 4 in the direction from the first connection portion 4a1 to the external connection connector 2 is, for example, less than 0.2 m. _{The length x 31} of the second metal plate portion 4 in the direction from the first connection portion 4a1 to the external connection connector 2 may be, for example, less than 0.18 m or less than 0.16 m.

As shown in FIG. 11, the first metal plate portion 3 has a third flat plate portion 3b, a third connecting portion 3a, a fourth connecting portion 3a2, and a fifth connecting portion 3a3. The fourth connecting portion 3a2 is separated from each of the third connecting portion 3a and the fifth connecting portion 3a3. Each of the third connecting portion 3a, the fourth connecting portion 3a2, and the fifth connecting portion 3a3 is bent substantially perpendicular to the third flat plate portion 3b. The third connection portion 3a is in contact with the ground pattern 5 at a corner portion formed by the second side portion 1b and the third side portion 1c. The fourth connection portion 3a2 is in contact with the ground pattern 5 at a corner portion formed by the third side portion 1c and the fourth side portion 1d. The fifth connection portion 3a3 is in contact with the ground pattern 5 at a corner portion formed by the fourth side portion 1d and the first side portion 1a. Both the third connection portion 3a and the fourth connection portion 3a2 are electrically connected to the frame ground via the ground pattern 5. Similarly, the fifth connection portion 3a3 is electrically connected to the frame ground via the ground pattern 5.

The first metal plate portion 3 mainly has a function of shielding electromagnetic wave noise radiated from the outside world. From the viewpoint of suppressing the resonance of electromagnetic noise radiated from the outside world, it is desirable to set the length of the first metal plate portion 3 as follows. Specifically, the diagonal length x ₆ of the first metal plate portion 3 is, for example, less than 0.15 m. _{The diagonal length x 6} of the first metal plate portion 3 may be, for example, less than 0.135 m, or may be, for example, less than 0.12 m.

According to the electronic device 100 according to the seventh embodiment, the second metal plate portion 4 includes a first connecting portion 4a1 and a second connecting portion 4a3 separated from the first connecting portion 4a1. The length of the second metal plate portion 4 in the direction from the first connecting portion 4a1 to the second connecting portion 4a3 is less than 0.2 m. As a result, the resonance of electrostatic noise can be further suppressed.

Further, according to the electronic device 100 according to the seventh embodiment, the second connection portion 4a3 is located closer to the external connection connector 2 than the first connection portion 4a1. The length of the second metal plate portion 4 in the direction from the first connection portion 4a1 to the external connection connector 2 is less than 0.2 m. As a result, the resonance of electrostatic noise can be further suppressed.

(Embodiment 8)
Next, the configuration of the electronic device 100 according to the eighth embodiment of the present invention will be described. The electronic device 100 according to the eighth embodiment has a structure in which the characteristics of the electronic device 100 according to the fifth embodiment are applied to the electronic device 100 according to the second embodiment.

As shown in FIG. 12, the electronic device 100 according to the eighth embodiment has a frame ground 8. The frame ground 8 is, for example, a metal housing of the electronic device 100 itself. As shown in FIG. 9, the frame ground 8 may be a board-shaped metal housing on which an electronic device 100 such as a printed circuit board 1 is mounted. The frame ground 8 supports, for example, the printed circuit board 1. The frame ground 8 may be located on the opposite side of the printed circuit board 1 from the signal ground 6. The ground pattern 5 is not provided on the printed circuit board 1. The first connecting portion 4a1 of the second metal plate portion 4 is directly connected to the frame ground 8 without passing through the ground pattern 5. The second metal plate portion 4 may be supported by the frame ground 8.

(Embodiment 9)
Next, the configuration of the electronic device 100 according to the ninth embodiment of the present invention will be described. The electronic device 100 according to the ninth embodiment is different from the electronic device 100 according to the second embodiment in the configuration in which the slit 11 is formed in the second metal plate portion 4, and the other configurations are the same as those in the second embodiment. It is almost the same as the electronic device 100 according to the second embodiment. Hereinafter, a configuration different from that of the electronic device 100 according to the second embodiment will be mainly described.

As shown in FIG. 13, a slit 11 is provided in the second metal plate portion 4 of the electronic device 100 according to the ninth embodiment. The slit 11 penetrates the second metal plate portion 4 in a direction parallel to the printed circuit board 1. Specifically, the slit 11 penetrates the second metal plate portion 4 in a direction parallel to the first side portion 1a. The slit 11 may be formed by being surrounded by the second metal plate portion 4, or may be formed by being surrounded by the second metal plate portion 4 and the first metal plate portion 3. As shown in FIG. 13, the width of the slit 11 in the direction parallel to the printed circuit board 1 may be larger than the width of the slit 11 in the direction perpendicular to the printed circuit board 1.

The heat generated from the integrated circuit 10 on the printed circuit board 1 covered with the metal plate in which the first metal plate portion 3 and the second metal plate portion 4 are integrated is dissipated through the slit 11. At this time, the noise of the integrated circuit 10 is radiated. In order to suppress the resonance of noise in the slit 11, it is desirable to set the length of the slit 11 as follows. The maximum frequency of radiated emissions is, for example, 1 GHz. _{The wavelength λ 2} of the radio wave having a frequency of 1 GHz is 300 (Mm / s) / 1000 (MHz) = 0.3 (m). The length of the slit 11, becomes equal to lambda _2/2, the noise is likely to be emitted. Therefore, it is desirable that the length of the slit 11 is less than 0.3 / 2 = 0.15 m.

_{Specifically, the width x 7} of the slit 11 in the direction parallel to the printed circuit board 1 is, for example, less than 0.15 m. _{The width x 7} of the slit 11 in the direction parallel to the printed circuit board 1 may be, for example, less than 0.135 m or less than 0.12 m. _{Similarly, the width x 8} of the slit 11 in the direction perpendicular to the printed circuit board 1 is, for example, less than 0.15 m. _{The width x 8} of the slit 11 in the direction perpendicular to the printed circuit board 1 may be, for example, less than 0.135 m or less than 0.12 m.

According to the electronic device 100 according to the ninth embodiment, the second metal plate portion 4 is provided with a slit 11 penetrating in a direction parallel to the printed circuit board 1. As a result, the heat generated from the integrated circuit 10 on the printed circuit board 1 can be dissipated through the slit 11.

Further, according to the electronic device 100 according to the ninth embodiment, the width of the slit 11 in the direction parallel to the printed circuit board 1 is less than 0.15 m, and the width of the slit 11 in the direction perpendicular to the printed circuit board 1 is. It is less than 0.15 m. This makes it possible to suppress the resonance of electromagnetic noise radiated from the outside world. As a result, the influence of electromagnetic noise on the integrated circuit 10 can be reduced.

(Embodiment 10)
Next, the configuration of the electronic device 100 according to the tenth embodiment of the present invention will be described. The electronic device 100 according to the tenth embodiment is different from the electronic device 100 according to the first embodiment mainly in a configuration in which the fourth region 4b3 is extended, and other configurations are described in the first embodiment. It is almost the same as the electronic device 100. Hereinafter, a configuration different from that of the electronic device 100 according to the first embodiment will be mainly described.

As shown in FIG. 14, in the electronic device 100 according to the tenth embodiment, the fourth region 4b3 is extended. As a result, radiation from the cable connected to the external connection connector 2 can be shielded. _{From the viewpoint of suppressing the resonance of electrostatic noise, the length x 2} of the first flat plate portion 4a in the direction parallel to the second side portion 1b and the length of the second flat plate portion 4b in the direction parallel to the first side portion 1a. the sum of x ₃ is desirably set to be less than half the wavelength of the maximum frequency of static electricity. The length of the first flat plate portion 4a _{x 2} and the sum of the length _{x 3} of the second flat plate portion 4b is, for example, less than 0.2 m. The length of the first flat plate portion 4a _{x 2} and the sum of the length _{x 3} of the second flat plate portion 4b may be, for example, be less than 0.18 m, it may be less than 0.16 m.

(Embodiment 11)
Next, the configuration of the electronic device 100 according to the eleventh embodiment of the present invention will be described. The electronic device 100 according to the eleventh embodiment has a structure in which the characteristics of the electronic device 100 according to the fourth embodiment are applied to the electronic device 100 according to the tenth embodiment.

As shown in FIG. 15, in the electronic device 100 according to the eleventh embodiment, the ground pattern 5 is provided on both sides of the external connection connector 2 in a direction parallel to the first side portion 1a. The second metal plate portion 4 has a first flat plate portion 4a, a second flat plate portion 4b, and a sixth connecting portion 4c. The sixth connecting portion 4c is connected to the second flat plate portion 4b. The sixth connecting portion 4c is connected to the ground pattern 5 along the first side portion 1a. The sixth connection portion 4c is located between the external connection connector 2 and the fourth side portion 1d. _{As described above, from the viewpoint of suppressing the resonance of electrostatic noise, the length x 2} of the first flat plate portion 4a in the direction parallel to the second side portion 1b and the second flat plate portion in the direction parallel to the first side portion 1a. It is desirable that the sum of the length x ₃ of the part 4b is set to less than half the wavelength of the maximum frequency of static electricity. The length of the first flat plate portion 4a _{x 2} and the sum of the length _{x 3} of the second flat plate portion 4b is, for example, less than 0.2 m. The length of the first flat plate portion 4a _{x 2} and the sum of the length _{x 3} of the second flat plate portion 4b may be, for example, be less than 0.18 m, it may be less than 0.16 m.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include the meaning equivalent to the scope of claims and all modifications within the scope.

1 Printed circuit board, 1a 1st side, 1b 2nd side, 1c 3rd side, 1d 4th side, 2 External connection connector, 2a 1st connector, 2b 2nd connector, 3 1st metal Plate part, 3a 3rd connection part, 3a2 4th connection part, 3a3 5th connection part, 3b 3rd flat plate part, 4th metal plate part, 4a 1st flat plate part, 4a1 1st connection part, 4a2 1st region 4, 4a3 2nd connector, 4b 2nd flat plate, 4b1 2nd region, 4b2 3rd region, 4b3 4th region, 4b4 5th region, 4b5 6th region, 4b6 7th region, 4c 6th connector, 5 Earth pattern, 6 signal ground, 8 frame ground, 9 metal frame, 10 integrated circuits, 11 slits, 100 electronics.

Claims (13)

A printed circuit board equipped with integrated circuits and connectors for external connection,
A metal frame that covers the external connector and
A first metal plate portion that covers the integrated circuit and faces at least a part of the printed circuit board.
It is provided with a second metal plate portion that is electrically connected to the metal frame and extends in a direction perpendicular to the printed circuit board.
Both the first metal plate portion and the second metal plate portion are configured to be electrically connectable to the frame ground.
The printed circuit board is provided with a signal ground connected to the integrated circuit.
The distance between the signal ground and the second metal plate portion in the direction parallel to the printed substrate is the distance between the signal ground and the first metal plate portion in the direction perpendicular to the printed substrate. That's all for electronic devices. The printed circuit board is provided with an earth pattern in contact with both the first metal plate portion and the second metal plate portion.
The electronic device according to claim 1, wherein both the first metal plate portion and the second metal plate portion are electrically connected to the frame ground via the earth pattern. The length of the second metal plate portion in the direction perpendicular to the printed substrate is less than 0.2 m, and the length of the second metal plate portion in a plane parallel to the printed substrate is , The electronic device according to claim 1 or 2, which is less than 0.2 m. The electronic device according to any one of claims 1 to 3, wherein the first metal plate portion is separated from the second metal plate portion. The second metal plate portion includes a first connecting portion and a second connecting portion separated from the first connecting portion.
Both the first connection and the second connection are electrically connected to the frame ground.
The electronic device according to claim 4, wherein the length of the second metal plate portion in the direction from the first connecting portion to the second connecting portion is less than 0.2 m. The second connection portion is located closer to the external connection connector than the first connection portion, and is located closer to the external connection connector.
The electronic device according to claim 5, wherein the length of the second metal plate portion in the direction from the first connection portion to the external connection connector is less than 0.2 m. The first metal plate portion includes a third connecting portion and a fourth connecting portion separated from the third connecting portion.
Both the third connection and the fourth connection are electrically connected to the frame ground.
The electronic device according to claim 5 or 6, wherein the length of the first metal plate portion in the direction from the third connection portion to the fourth connection portion is less than 0.15 m. The electronic device according to any one of claims 1 to 3, wherein the first metal plate portion is connected to the second metal plate portion. The outer shape of the first metal plate portion is a quadrangle when viewed from a direction perpendicular to the printed circuit board.
The electronic device according to claim 8, wherein the total of the diagonal length of the first metal plate portion and the length of the second metal plate portion in the direction perpendicular to the printed circuit board is less than 0.2 m. The second metal plate portion includes a first connecting portion and a second connecting portion separated from the first connecting portion.
Both the first connection and the second connection are electrically connected to the frame ground.
The electronic device according to claim 8 or 9, wherein the length of the second metal plate portion in the direction from the first connecting portion to the second connecting portion is less than 0.2 m. The second connection portion is located closer to the external connection connector than the first connection portion, and is located closer to the external connection connector.
The electronic device according to claim 10, wherein the length of the second metal plate portion in the direction from the first connection portion to the external connection connector is less than 0.2 m. The electronic device according to any one of claims 8 to 11, wherein the second metal plate portion is provided with a slit penetrating in a direction parallel to the printed circuit board. The electron according to claim 12, wherein the width of the slit in the direction parallel to the printed circuit board is less than 0.15 m, and the width of the slit in the direction perpendicular to the printed circuit board is less than 0.15 m. machine.

Images