JP2008083807A - Electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electronic equipment allowing further improvement of reliability in ground connection. <P>SOLUTION: Reduction of a value of electric resistance between a boss 25 for connecting a hinge metal fitting 10b and a boss 15 for connecting a circuit board 12 is effective so as to stably lead noise current generated from a display panel to ground. There is a method increasing a surface area between the boss 15 and the boss 25, for example, so as to reduce the electric resistance between the boss 15 and the boss 25. That is, by providing a recessed and projecting part 30 in a part of an internal face 9a of a lower case 9, a surface applied with metal plating can be increased. Because the noise current generated from the display panel can be stably led to the ground of the circuit board 12 when an area applied with the plating between the boss 15 and the boss 25 increases to reduce the electric resistance, it is effective in EMI measures. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to electronic equipment, and more particularly to EMI countermeasure technology.

  With miniaturization and high integration of electronic devices, countermeasures against electromagnetic wave noise generated from the inside of electronic devices are becoming increasingly important. The radiated electromagnetic noise may lead to malfunction of peripheral devices and malfunction of the device itself that is a noise generation source. As a countermeasure against electromagnetic wave noise, one method is to use a metal such as iron or aluminum for the casing to shield electromagnetic waves emitted from electronic devices. Since portable electronic devices such as laptop computers are required to be lighter, a conductive layer is provided on a resin casing by metal plating, and an electromagnetic wave shielding layer is formed. A boss is formed on the housing having the electromagnetic shielding layer formed on the inner surface, and a printed circuit board having a ground plane as an inner layer is fixed to the boss with a screw.

Japanese Patent Application Laid-Open No. H10-228561 describes a technique for reducing electromagnetic waves radiated to space by forming a resistor pattern on a boss. A current flows between the ground of the printed circuit board and the shield layer of the housing via the boss. Since the resistor pattern formed on the boss acts as a resistor that allows a predetermined amount of current to flow, the resonance current is consumed to reduce the resonance energy. As a result, it is possible to suppress electromagnetic waves radiated to the space due to resonance.
Japanese Patent Laid-Open No. 2002-359489

  In addition to the above-described shield technology that prevents outflow and intrusion of electromagnetic noise, it is also important to secure a return path for guiding the noise current to the ground. In order to strengthen the ground, it is desirable to connect the component that generates the noise current and the ground of the printed circuit board to directly guide the noise current to the ground. However, a component that generates noise current may not be directly connected to the printed circuit board due to restrictions on the mounting space in the casing and the convenience of component arrangement.

  Accordingly, an object of the present invention is to provide an electronic apparatus capable of further improving the reliability of ground connection.

  In order to achieve the above object, an electronic apparatus according to the present invention includes a casing having an upper case and a lower case, a conductive coating applied to the inner surface of the lower case, and a first provided on the inner surface of the lower case. And a second boss provided on the inner surface of the lower case so as to be separated from the first boss, and the inner surface of the lower case includes the first boss and the second boss. An uneven portion is provided between them.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic device which can improve the reliability of a ground connection can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view showing an electronic apparatus according to an embodiment of the present invention. In the present embodiment, a notebook computer will be described as an example of an electronic device. The computer 1 includes a main body 2, and a display unit 3 is rotatably attached to the main body 2 via a hinge portion 4. A touch pad 5 is attached to the front upper surface 2 a of the main body 2. A keyboard 6 is attached to the rear upper surface 2 b of the main body 2. The main body 2 has an upper case 8 and a lower case 9 made of resin or a metal such as magnesium alloy, and a circuit board (described later) on which a plurality of electronic components are mounted is accommodated in the main body 2.

  FIG. 2 is a diagram showing an outline of a connection state between a circuit board provided in the electronic apparatus and the display panel. FIG. 2 shows the inside of the main body 2 of the computer 1 and the inside of the display unit 3. The upper case 8 of the computer 1 is removed and the circuit board 12 is exposed. Further, the display unit 3 is open with respect to the main body 2.

  A display panel 3 a such as a liquid crystal is provided inside the display unit 3. The display unit 3 is provided with hinge fittings 10a and 10b. The hinge fittings 10 a and 10 b have a bent portion 11 so that the hinge fitting 10 a and 10 b can be bent in accordance with the rotation of the display unit 3. The noise current generated from the display panel 3a is introduced to the ground of the circuit board 12 through the hinge fittings 10a and 10b.

  The inner surface 9a of the lower case 9 is subjected to metal plating with, for example, copper or nickel in order to shield electromagnetic waves radiated from electronic components on the circuit board 12. A plurality of bosses, which will be described later, are provided on the inner surface 9a of the lower case 9, and the lower case 9 and the circuit board 12 are screwed with screws 14 through the bosses. The hinge metal fitting 10a and the circuit board 12 are screwed to the lower case 9 with screws 13a via bosses. The hinge fitting 10a provided on the display unit 3 is fixed so as to be grounded to the ground of the circuit board 12. The other hinge fitting 10b provided on the display unit 3 is screwed with a screw 13b so as to be connected to a boss provided on the lower case 9.

  In order to strengthen the ground, it is desirable to connect the hinge fittings 10a and 10b of the display unit 3 to the ground of the circuit board 12 and to directly introduce the noise current to the ground. However, the hinge fittings 10a and 10b and the circuit board 12 may not be directly connected depending on the restrictions on the mounting space in the circuit board 12 and the main body 2 and the convenience of component arrangement. In order to stably guide the noise current generated from the display panel 3a to the ground, the value of the electrical resistance between the boss for connecting the hinge fitting 10b and the boss for connecting the circuit board 12 should be reduced. validate. In order to reduce the electrical resistance between the boss and the boss, for example, there is a method of increasing the surface area between the boss and the boss. That is, by providing unevenness on a part of the inner surface 9a of the lower case 9, it is possible to increase the number of surfaces that have been subjected to metal plating. If unevenness is provided in the region A between the bosses, the area where the plating between the bosses and the bosses is increased increases, so that the electrical resistance is lowered. If the electric resistance in the region A can be lowered, the noise current generated from the display panel 3a can be stably guided to the ground of the circuit board 12, which is effective for EMI countermeasures.

FIG. 3 is an exploded perspective view showing the connection relationship between the case of the electronic device and the circuit board.
On the inner surface 9 a of the lower case 9 of the main body 2, a boss 15 protrudes upward and is provided integrally with the lower case 9. The boss 15 has a boss hole 16. A metal insert nut 17 is inserted into the boss hole 16. An internal screw (not shown) is formed in the inside 17 a of the insert nut 17. An external screw 17 b is formed outside the insert nut 17. After the insert nut 17 is inserted into the boss hole 16, the external screw 17b and the inner surface 15a of the boss 15 are integrally attached by welding or the like. The circuit board 12 is provided with a through hole 12a. The circuit board 12 is fixed to the lower case 9 by the screw 14 being screwed into an internal screw formed in the inside 17a of the insert nut 17 through the through hole 12a.

  On the other hand, the boss 25 protrudes upward like the boss 15 and is provided integrally with the lower case 9. The boss 25 has a boss hole 26 and is used to connect the hinge fitting 10 b and the lower case 9. As the insert nut 17 for connecting the hinge metal fitting 10b and the lower case 9, the same one as that for connecting the lower case 9 and the circuit board 12 can be adopted. The insert nut 17 is inserted into the boss hole 26, and the outer screw 17b of the insert nut 17 and the inner surface 25a of the boss 25 are integrally attached by welding or the like. The hinge fitting 10b is provided with a through hole 10c, and the screw 13b is screwed into an inner screw formed in the inside 17a of the insert nut 17 through the through hole 10c, whereby the hinge fitting 10b is attached to the lower case 9. Fixed.

  As described above, in order to stably lead the noise current to the ground of the circuit board 12, the electric resistance between the boss 25 for connecting the hinge fitting 10 b and the boss 15 for connecting the circuit board 12 is reduced. It is effective to reduce the value. In order to reduce the electrical resistance between the boss 15 and the boss 25, for example, there is a method of increasing the surface area of the plating surface formed between the boss 15 and the boss 25. That is, by providing the uneven portion 30 on a part of the surface 9a of the lower case 9, the plated area can be increased as compared with the case where the surface 9a is flat. When the concavo-convex portion 30 is provided, the area of the plating surface in the region between the boss 15 and the boss 25 increases, so that the electrical resistance is lowered. By reducing the electrical resistance value between the boss 15 and the boss 25, the lower case 9 and the circuit board 12 can be connected to the ground with a lower resistance value, which is effective for EMI countermeasures.

  FIG. 4 is a view showing the shape of the concavo-convex portion according to the embodiment of the present invention. Various shapes of the concavo-convex portion 30 provided between the boss 15 and the boss 25 can be considered. For example, as shown in FIG. 4, it can be set as the shape where a rectangular parallelepiped was continuously arrange | positioned through a space | interval. The uneven portion 30 has an upper surface 31, a side wall 32, and a bottom surface 33. The side walls 32 are formed so as to rise from the bottom surface 33, and the side walls 32 are provided so as to face each other. The upper surface 31 is formed so as to extend from one side wall 32 to the other side wall 32. The bottom surface 33 may be formed so as to be integrated with the inner surface 9 a of the lower case 9.

  By adopting such a shape, since the area of the plating surface between the boss 15 and the boss 25 is increased, the resistance value between the boss 15 and the boss 25 is decreased.

  FIG. 5 is a diagram showing the shape of the concavo-convex portion according to another embodiment of the present invention. As shown in FIG. 5, the concavo-convex portion 40 may be formed in a shape in which triangular prisms are continuously connected. The concavo-convex portion 40 has side walls 41 and 42 extending from the bottom surface 43, and the side wall 41, the side wall 42, and the bottom surface 43 form a triangular prism. Even if such a shape is adopted for the concavo-convex portion 40, since the area of the plating surface is increased, the resistance value between the boss 15 and the boss 25 can be reduced. Like the uneven part 40 shown in FIG. 5, it is good also as a shape where it arrange | positioned through the space | interval not only in what a triangular prism continues continuously.

  FIG. 6 is a view showing the shape of the concavo-convex portion according to another embodiment of the present invention. As shown in FIG. 6, the concavo-convex portion 50 may have a corrugated shape having a periodic gradient in cross section. FIG. 7 is a view showing a cross section taken along the line CC ′ in FIG. 6. A bottom surface portion 51 and a top surface portion 52 having a curvature are formed. The bottom surface portion 51 may be formed so as to be integrated with the inner surface 9 a of the lower case 9. Even if such a shape is adopted for the concavo-convex portion 50, since the area of the plating surface is increased, the resistance value between the boss 15 and the boss 25 can be reduced. Various shapes other than those shown in FIGS. 4 to 6 can be adopted as the shape of the concavo-convex portion.

  In the above-described embodiment, the case where the concavo-convex portion is provided between the boss connecting the hinge metal fitting and the boss connecting the circuit board has been described as an example. For example, when the first circuit board and the second circuit board having the ground layer cannot be connected with a cable, unevenness is formed between the boss connecting the first circuit board and the boss connecting the second circuit board. A part can also be provided. With such a configuration, the noise current generated from the first circuit board can be more stably guided to the ground of the second circuit board.

  As described above, when the present invention is implemented, it is possible to provide an electronic device that can further improve the reliability of ground connection.

  The present invention is not limited to the above embodiment as long as it does not depart from the gist of the present invention, and various modifications are possible.

1 is an external perspective view showing an electronic apparatus according to an embodiment of the present invention. The figure which shows the outline of the connection state of the circuit board provided in the electronic device, and a display panel. The disassembled perspective view which shows the connection relationship between the case of an electronic device, and a circuit board. The figure which showed the shape of the uneven | corrugated | grooved part which concerns on embodiment of this invention. The figure which showed the shape of the uneven | corrugated | grooved part which concerns on other embodiment of this invention. The figure which showed the shape of the uneven | corrugated | grooved part which concerns on other embodiment of this invention. The figure which shows the cross section cut along CC 'line in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Computer, 2 ... Main body, 3 ... Display unit, 4 ... Hinge part, 5 ... Touch pad, 6 ... Keyboard, 8 ... Upper case, 9 ... Lower case, 10a ... Hinge bracket, 10b ... Hinge bracket, 10c ... Through Hole: 11 ... Bent part, 12 ... Circuit board, 13a ... Screw, 13b ... Screw, 14 ... Screw, 15 ... Boss, 16 ... Boss hole, 17 ... Insert nut, 25 ... Boss, 26 ... Boss hole, 30 ... Uneven Part

Claims (7)

A housing having an upper case and a lower case;
Conductive coating applied to the inner surface of the lower case;
A first boss provided on the inner surface of the lower case;
A second boss provided on the inner surface of the lower case and spaced apart from the first boss,
An electronic device, wherein an uneven portion is provided on the inner surface of the lower case between the first boss and the second boss. A housing having an upper case and a lower case;
Conductive coating applied to the inner surface of the lower case;
A first boss provided on the inner surface of the lower case;
A second boss provided on the inner surface of the lower case and spaced apart from the first boss;
A first circuit board having a through hole and connected to the first boss via a first screw;
A second circuit board having a through hole, connected to the second boss via a second screw, and having a ground layer inside,
An electronic device, wherein an uneven portion is provided on the inner surface of the lower case between the first boss and the second boss. A housing having an upper case and a lower case;
A display housing rotatably attached to the housing;
A hinge fitting provided on the display housing and having a screw hole;
Conductive coating applied to the inner surface of the lower case;
A first boss provided on the inner surface of the lower case;
A first circuit board having a through hole, connected to the first boss via a first screw, and having a ground layer inside;
A second boss provided on the inner surface of the lower case so as to be spaced apart from the first boss and connected to the hinge bracket via a second screw;
An electronic device, wherein an uneven portion is provided on the inner surface of the lower case between the first boss and the second boss.   The electronic device according to claim 1, wherein a cube extending from the first boss to the second boss is formed in the uneven portion.   A first prism that extends in a direction from the first boss toward the second boss and a second prism that extends to face the first prism are formed in the uneven portion. The electronic device according to claim 1.   The protrusions and recesses are formed with protrusions extending in a direction from the first boss toward the second boss, and the protrusions have a triangular cross section. Electronic equipment. 4. The electronic device according to claim 1, wherein the uneven portion is formed with a wave-like convex portion extending in a direction from the first boss toward the second boss. 5.

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