JPH10173348A - Electronic equipment having case body containing circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic equipment capable of enhancing the shield effect of electromagnetic noise, while sufficiently securing the contact area between the ground layer of a circuit board and a case body. SOLUTION: This electronic equipment is provided with a circuit board 40 having an insulating layer 44, signal wiring layers 45a, 45b and a ground layer 46, arranged inside the insulating layer 44 as well as a conductive case body 24 containing the circuit board 40, also having a wall surface opposite to the circuit board 40. The circuit board 40 has a recessed part 52 passing through the circuit board 40 in the thickness direction thereof. A ground layer is exposed in the inner surface of this recession, while a conductive layer 54 electrically connected to the ground layer is formed on the outer periphery of the circuit board, including this recessed part. Furthermore, a conductive projection 56 to be inserted into the recession 52 is formed on the wall surface of the case body 24, while the projection 56 is in contact with the conductive layer of the circuit board 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic apparatus such as a portable computer having a housing for housing a circuit board, and more particularly to a structure for grounding the circuit board to the housing.

[0002]

2. Description of the Related Art In recent years, the performance of portable computers has been remarkably improved, and particularly, the clock frequency of CPUs has exceeded 100 MHz. This type of CPU is mounted on a circuit board, and this circuit board is housed inside the casing of the portable computer.

It is known that sources of electromagnetic noise in portable computers are mainly high-frequency clock circuits and signal circuits. Therefore, as CPU performance improves, EMI (electromagnetic interfere)
The demand for countermeasures tends to increase, and this EM
Countermeasure I is an important issue in securing the performance and reliability of the portable computer.

In a conventional portable computer, in order to suppress leakage of electromagnetic noise, the inner surface of the housing is subjected to electroless plating, and the inner surface is covered with a conductive plating layer. Connecting layers has been performed.

FIGS. 8 and 9 disclose an example of EMI measures for a conventional portable computer. In FIG. 8, reference numeral 1 denotes a housing of the portable computer. The housing 1 is made of a synthetic resin material, and a columnar boss 3 is integrally formed on a bottom wall 2 of the housing 1. The boss portion 3 has a screw hole 3a.
“a” is opened at the tip end surface of the boss 3. The inner surface of the housing 1 is covered with a conductive plating layer 4. The plating layer 4 continuously covers the boss 3.

A circuit board 5 on which a CPU is mounted is housed in the housing 1. The circuit board 5 includes an insulating layer 6 and
A solid ground layer 7 laminated inside the insulating layer 6
And a plurality of signal wiring layers 8a and 8b.

[0007] Ground patterns 9a and 9b are formed on the front surface 5a and the back surface 5b of the circuit board 5, respectively. These ground patterns 9a and 9b are
Are formed in quadrangular shapes each having a size substantially corresponding to the tip end surface of the boss portion 3.

The circuit board 5 includes ground patterns 9a, 9
A plurality of through holes 10 and a single screw insertion hole 11 are provided at a position corresponding to b. The through hole 10 and the screw insertion hole 11 are opened on the front surface 5a and the back surface 5b of the circuit board 5, and
Are arranged to penetrate the ground layer 7.

The inner surface of the through hole 10 is covered with a conductive plating layer 12. The plating layer 12 is in contact with the ground layer 7 and the ground patterns 9a and 9b. Therefore, the ground layer 7 is
Are electrically connected to the ground patterns 9a and 9b via the.

The circuit board 5 is arranged in parallel with the bottom wall 2. The back surface 5b of the circuit board 5 is overlaid on the tip surface of the boss 3. The screw hole 3 a of the boss 3 is continuous with the screw insertion hole 11 of the circuit board 5. This screw insertion hole 1
1, a metal screw 13 is inserted from above.
The insertion end of the screw 13 is screwed into the screw hole 3a, and the screwing fixes the circuit board 5 to the housing 1.

When the circuit board 5 is fixed to the housing 1, the head 13a of the screw 13 is in contact with the ground pattern 9a, and the plating layer 4 is in contact with the ground pattern 9b. For this reason, the ground layer 7 of the circuit board 5 is grounded to the housing 1 so that leakage of electromagnetic noise from the housing 1 is suppressed.

[0012]

According to the conventional portable computer, the ground pattern 9 of the circuit board 5 is
a, 9b are electrically connected to the plating layer 4 of the housing 1 through a contact portion with the tip end surface of the boss portion 3 and a contact portion with the head 13a of the screw 13.

However, the boss 3 of the housing 1 needs to avoid interference with various circuit components mounted on the circuit board 5 and the CPU, so that its diameter is as small as several millimeters. Since the screw hole 3a is opened at the tip end surface of the circuit board 3, a sufficient contact area with the ground pattern 8b of the circuit board 5 cannot be secured.

The diameter of the head 13a of the screw 13 in contact with the ground pattern 9a is often equal to or smaller than the diameter of the tip surface of the boss 3. Therefore, the contact area between the screw 13 and the ground pattern 9a is smaller than the contact area between the ground pattern 9b and the boss 3.

Therefore, according to the above-described conventional ground connection structure, the contact area between the ground layer 7 of the circuit board 5 and the housing 1 may be insufficient, and the electromagnetic noise shielding effect may not be sufficiently exerted. obtain.

In order to ensure a sufficient contact area between the circuit board 5 and the housing 1, it is conceivable to increase the number of bosses 3 and the number of ground patterns 9a and 9b. However, since a large number of circuit components are mounted on the circuit board 5 at high density and the mounting space on the circuit board 5 is already saturated, a large number of ground patterns 9a and 9b are provided on the circuit board 5. Is virtually impossible and cannot be an effective solution.

The present invention has been made in view of such circumstances, and it is possible to sufficiently secure a contact area between a ground layer of a circuit board and a housing, and to enhance an electromagnetic noise shielding effect. The purpose is to provide electronic equipment.

[0018]

According to an aspect of the present invention, there is provided an electronic apparatus comprising: an insulating layer; a signal wiring layer laminated on the insulating layer; and an electronic device disposed inside the insulating layer. A circuit board having a ground layer provided therein; and a conductive housing having a wall surface facing the circuit board for accommodating the circuit board. And
A concave portion penetrating the circuit board in the thickness direction is formed in an outer peripheral portion of the circuit board, and the ground layer is exposed on an inner surface of the concave portion. A conductive layer electrically connected to the layer is formed, and a conductive protrusion fitted into the recess is formed on a wall surface of the housing, and the protrusion is formed on the conductive layer of the circuit board. It is characterized by contact with

According to this structure, the conductive layer connected to the ground layer comes into contact with the convex portion of the housing when the concave portion of the circuit board is fitted to the convex portion of the housing. The ground layer of the substrate is grounded to the housing.

In this case, since the concave portion of the circuit board is located at the outer peripheral portion of the circuit board, the concave portion is formed along the outer peripheral portion of the circuit board, so that the conductive layer connected to the ground layer is formed. Can be arranged over a wide range of the outer peripheral portion of the circuit board. For this reason, compared with the conventional ground connection using the boss portion, the contact area between the ground layer of the circuit board and the housing can be sufficiently ensured, and the electromagnetic noise shielding effect can be enhanced.

Further, since the outer peripheral edge of the circuit board is covered with the conductive layer, it is possible to prevent electromagnetic noise from the outside of the housing from entering the outer peripheral edge of the circuit board, and the noise resistance of the circuit board against external noises Is improved.

Moreover, when the circuit board is accommodated in the housing, the projections and the recesses fit together, so that the projections and the recesses function as positioning guides for the circuit board with respect to the housing. Therefore, the position of the circuit board inside the housing is accurately determined, and the conductive layer of the circuit board can be reliably brought into contact with the housing.

According to a second aspect, the case described in the first aspect is made of a synthetic resin, and the wall surface and the projection of the case are covered with a conductive plating layer. The conductive layer of the circuit board is in contact with the plating layer.

According to this configuration, the electromagnetic shielding effect of the housing can be enhanced while reducing the weight of the housing.
This is particularly advantageous for an electronic device such as a portable computer that requires portability.

According to a third aspect, in the first or second aspect, the concave portion is disposed at a plurality of locations on an outer peripheral edge of the circuit board, and the convex portion is disposed at a plurality of locations on the wall surface. ing.

According to this configuration, the conductive layer of the circuit board and the projection of the housing can be brought into contact at a plurality of locations. Therefore, the contact area between the conductive layer of the circuit board and the housing is further increased, and the electrical connection between the ground layer of the circuit board and the housing is ensured.

According to a fourth aspect, the casing according to the first aspect has a seat for receiving the circuit board, and the circuit board is fixed to the seat via a screw, and The recess of the circuit board is disposed at a position adjacent to the seat, and the conductive layer covering the recess has an extension extending to a position corresponding to the seat, and the extension is When the circuit board is fixed to the seat, it is in contact with the seat.

According to this configuration, since the conductive layer is interposed in the fixed portion between the circuit board and the seat, the contact area between the conductive layer of the circuit board and the housing can be further increased. In addition, since the extension of the conductive layer is pressed against the seat when the screw is tightened, the contact state between the conductive layer and the housing is improved.

According to another aspect of the present invention, there is provided an electronic apparatus comprising: an insulating layer; a signal wiring layer laminated on the insulating layer; a ground layer disposed inside the insulating layer; And a conductive housing that houses the circuit board and has an inner surface facing the circuit board. Then, at least a part of the ground layer is exposed on an outer peripheral surface of the circuit board, and a conductive layer electrically connected to the ground layer is formed on an outer peripheral edge of the circuit board including the outer peripheral surface. The conductive layer is in contact with the inner surface of the housing.

According to this configuration, the conductive layer connected to the ground layer comes into contact with the inner surface of the housing when the circuit board is housed inside the housing, and this contact causes the ground layer of the circuit board to be in contact with the housing. Grounded to body.

In this case, since the conductive layer is located at the outer peripheral edge of the circuit board, the conductive layer can be arranged over a wide range of the outer peripheral edge of the circuit board. For this reason, compared with the conventional ground connection using the boss portion, the contact area between the ground layer of the circuit board and the housing can be sufficiently ensured, and the electromagnetic noise shielding effect can be enhanced.

Further, since the outer peripheral edge of the circuit board is covered with the conductive layer, it is possible to prevent electromagnetic noise from outside the housing from entering the outer peripheral edge of the circuit board. Therefore, the noise resistance of the circuit board against external noise is improved.

According to the sixth aspect, the case described in the fifth aspect is made of a synthetic resin, and the inner surface of the case is covered with a conductive plating layer. The conductive layer of the circuit board is in contact with the layer.

According to this configuration, the electromagnetic shielding effect of the housing can be enhanced while reducing the weight of the housing.
This is particularly advantageous for an electronic device such as a portable computer that requires portability.

According to another aspect of the present invention, there is provided an electronic apparatus comprising: an insulating layer; a signal wiring layer laminated on the insulating layer; a ground layer disposed inside the insulating layer; And a conductive housing that houses the circuit board and has a wall facing the outer peripheral surface of the circuit board. Then, at least a part of the ground layer is exposed on an outer peripheral surface of the circuit board, and a conductive layer electrically connected to the ground layer is formed on an outer peripheral edge of the circuit board including the outer peripheral surface. A conductive member separate from the housing is interposed between the conductive layer and the wall surface of the housing, and the conductive layer and the housing are electrically connected to each other through the conductive member. It is characterized by that.

According to this configuration, the conductive layer connected to the ground layer comes into contact with the wall surface of the housing via the conductive member when the circuit board is housed in the housing.
The ground layer of the circuit board is grounded to the housing.

In this case, since the conductive layer is located at the outer peripheral edge of the circuit board, the conductive layer can be arranged along the outer peripheral edge of the circuit board, and the conductive layer can be disposed over a wide area of the circuit board. Can be exposed. For this reason, compared with the conventional ground connection using the boss portion, the contact area between the ground layer of the circuit board and the housing can be sufficiently ensured, and the electromagnetic noise shielding effect can be enhanced.

Further, since the outer peripheral edge of the circuit board is covered with the conductive layer, it is possible to prevent electromagnetic noise from outside the housing from entering the outer peripheral edge of the circuit board. Therefore, the noise resistance of the circuit board against external noise is improved.

According to the eighth aspect, the circuit board according to the seventh aspect has a concave portion penetrating the circuit board in a thickness direction at an outer peripheral edge portion including an outer peripheral surface thereof, and the inner surface of the concave portion has The ground layer is exposed, and the outer peripheral edge of the circuit board including the concave portion is covered with the conductive layer, and the conductive member is fitted in the concave portion, and is connected to the conductive layer. In contact.

In this configuration, when the circuit board is housed in the housing, the conductive members fit into the recesses, and the conductive members contact the conductive layer covering the recesses. Therefore, the recess functions as a guide for positioning the conductive member with respect to the circuit board, and the conductive layer of the circuit board can be reliably brought into contact with the conductive member.

According to a ninth aspect, in the seventh or eighth aspect, the conductive member is soldered to a conductive layer of the circuit board. According to this configuration, the conductive member is integrated with the circuit board, and electrical conduction between the conductive member and the conductive layer is ensured.

According to the tenth aspect, the circuit board according to the seventh aspect is supported by a metal frame, is housed in the housing via the frame, and is mounted on the frame. The conductive member is formed integrally. According to this configuration, the positions of the conductive layer and the conductive member of the circuit board are accurately determined, and the ground layer of the circuit board can be reliably grounded to the frame.

[0043]

FIG. 1 to FIG. 3 in which a first embodiment of the present invention is applied to a portable computer.
It will be described based on the following. FIG. 1 discloses a book-type portable computer 21. This computer 2
1 includes a computer main body 22 and a display unit 23 supported by the computer main body 22.

The computer main body 22 has a housing 24 made of synthetic resin. The housing 24 has a lower housing 25 and an upper housing 26 detachably connected to the lower housing 25, and has a flat box shape as a whole.

As shown in FIG. 1 to FIG.
Has a flat bottom wall 27, front, rear, left and right peripheral walls 28 continuous with the peripheral edge of the bottom wall 27, and an upper wall 29 facing the bottom wall 27.

A keyboard 31 is arranged in the front half of the upper wall 29 of the housing 24. At the rear end of the upper wall 29, a projection 32 is arranged. The protrusion 32 extends along the width direction of the housing 24. The convex portion 32 has a pair of display support portions 33a and 33b. These display support parts 33a and 33b are arranged apart from each other in the width direction of the housing 24.

The display unit 23 has a flat box-shaped casing 35 and a liquid crystal display 36 housed inside the casing 35. The casing 35 has a display opening 35a, and the display screen 36a of the liquid crystal display device 36 is exposed to the opening 35a.

The casing 35 includes a pair of support legs 38.
a, 38b. These support legs 38a, 38
b denotes the display support portions 33a, 33 of the housing 24.
b, and are respectively connected to the housing 24 via hinge devices (not shown).

Therefore, the display unit 23
The housing 24 is rotatably supported over a closed position that covers the keyboard 31 and an open position that exposes the keyboard 31.

As shown in FIGS. 2 and 3, a circuit board 40 is housed inside the housing 24. Circuit board 40
Are arranged in parallel with the bottom wall 27 of the housing 24, and at a corner defined by the bottom wall 27 and the peripheral wall 28, a plurality of seats 41 for receiving the circuit board 40 are integrally formed. I have. The seats 41 are arranged at positions corresponding to the corners of the circuit board 40, and each seat 41 has a screw hole 4.
A metal nut 42 having 2a is inserted.

The circuit board 40 includes an insulating layer 44 and a plurality of signal wiring layers 45a and 45 laminated inside the insulating layer 44.
5b and a solid ground layer 46. The signal wiring layers 45a and 45b and the ground layer 46 are arranged in parallel with an interval therebetween.
Then, the front surface 40a and the back surface 40 of the circuit board 40
A CPU and other semiconductor chips (not shown) are mounted on b. These CPUs and semiconductor chips are electrically connected to the signal wiring layers 45a and 45b and the ground layer 46. Therefore, the signal wiring layers 45a, 45
A high-speed signal flows through b.

A screw insertion hole 48 is formed at a corner of the circuit board 40.
Are formed. A metal screw 49 is inserted into the screw insertion hole 48 from above. The screw 49 passes through the screw insertion hole 48 and is screwed into the screw hole 42a of the seat 41. By this screwing, the corners of the circuit board 40 are sandwiched between the head 49 a of the screw 49 and the seat 41, and the circuit board 40 is fixed to the housing 24.

As shown in FIG. 2, the circuit board 40 includes a first outer peripheral edge 50 and a second outer peripheral edge 5 orthogonal to each other.
And 1. First and second outer peripheral edges 50, 5
1 includes an outer peripheral surface 40c (shown in FIG. 3A) continuous with the front surface 40a and the back surface 40b of the circuit board 40. The first and second outer peripheral edges 50 and 51 extend along the inner wall surface of the peripheral wall 28 of the housing 24 and are adjacent to the inner wall surface of the peripheral wall 28.

A plurality of recesses 52 are formed in the first and second outer peripheral edges 50 and 51, respectively. Recess 52
Penetrates the circuit board 40 in the thickness direction at positions separated in the longitudinal direction of the first and second outer peripheral edges 50 and 51. The concave portion 52 has the first and second outer peripheral edge portions 5.
0, 51 has an elongated shape like a notch along the longitudinal direction, and in the present embodiment, is adjacent to a corner of the circuit board 40.

As shown in FIGS. 3A and 3B, the recess 5
2 has a flat inner surface 52a. The inner surface 52a
The end portion of the ground layer 46 is exposed to the outer surface 40c of the circuit board 40, and the inner surface 52a is exposed.

As shown in FIGS. 2 and 3 (A) and (B),
An inner surface 52a of the concave portion 52 is provided with a plating layer 54 as a conductive layer.
Covered by The plating layer 54 is connected to the ground layer 46. This plating layer 54 is
2 as well as the front surface 40a, the back surface 40b, and the outer peripheral surface 4 of the circuit board 40 connected to the inner surface 52a.
0c is continuously covered.

The peripheral wall 28 of the housing 24 faces the first and second outer peripheral edges 50 and 51 of the circuit board 40. A plurality of protrusions 56 are formed integrally on the inner surface of the peripheral wall 28. The convex portion 56 is provided in the concave portion 52 of the circuit board 40.
And are fitted in the concave portions 52, respectively.

The inner surfaces of the bottom wall 27 and the peripheral wall 28 of the housing 24 are covered with a plating layer 57 as a conductive layer. The plating layer 57 is formed of the seat portion 41 of the bottom wall 27 or the peripheral wall 2.
8 are continuously covered. Therefore, the protrusion 5
When 6 is fitted in the concave portion 52 of the circuit board 40, the plating layer 57 covering the convex portion 56 is in contact with the plating layer 54 covering the inner surface 52 a of the concave portion 52. By this contact, the ground layer 46 of the circuit board 40 is electrically connected to the plating layer 57 of the housing 24, and the circuit board 40 is grounded to the housing 24.

According to such a configuration, the recess 52 of the circuit board 40 extends along the longitudinal direction of the first and second outer peripheral edges 50 and 51 of the circuit board 40, Ground layer 46 and this ground layer 46
Can be exposed over a wide range of the first and second outer peripheral edges 50 and 51 of the circuit board 40.

For this reason, compared to the conventional ground connection using the boss, the ground layer 46 of the circuit board 40 and the housing 2
4 can secure a sufficient contact area, and the electromagnetic noise shielding effect can be enhanced.

In particular, the concave portion 52 and the convex portion 5 which fit each other
6 are formed over a plurality of portions of the first and second outer peripheral edges 50 and 51 of the circuit board 40 and the peripheral wall 28 of the housing 24, respectively. Of the circuit board 40, and the electrical connection between the ground layer 46 of the circuit board 40 and the housing 24 can be ensured.

Further, since the first and second outer peripheral edges 50 and 51 of the circuit board 40 are covered with the conductive plating layer 54, electromagnetic noise from outside the housing 24 is protected from the outside of the circuit board 40. Intrusion into the peripheral edges 50 and 51 can be prevented. Therefore, the noise resistance of the circuit board 40 against external noise is improved, and a malfunction of the circuit can be avoided.

Further, in the case of the above configuration, when the circuit board 40 is accommodated in the housing 24,
Fit into the convex portion 56 of the housing 24,
The projection 56 functions as a positioning guide for the circuit board 40 with respect to the housing 24. As a result, the position of the circuit board 40 inside the housing 24 is accurately determined, and the circuit board 4
The zero plating layer 54 can be reliably brought into contact with the plating layer 57 on the housing 24 side.

In addition, the bottom wall 27 and the peripheral wall 2 of the housing 24
8 is formed with a plating layer 57 on the inner surface thereof, so that the synthetic resin housing 24 is made conductive.
The electromagnetic shielding effect of the housing 24 can be enhanced while reducing the weight of the housing 24. This is particularly advantageous for an electronic device that requires portability, such as the portable computer 21.

The present invention is not limited to the first embodiment, and FIG. 4 shows a second embodiment of the present invention. The second embodiment differs from the first embodiment in the configuration of the ground connection portion between the circuit board 40 and the housing 24, and the other configurations are the same as those in the first embodiment. The same is true. Therefore, in the second embodiment, the same components as those in the first embodiment are described.
The same reference numerals are given and the description is omitted.

As shown in FIG.
The plating layer 54 that covers 2 has extensions 61 a and 61 b that extend to positions corresponding to the corners of the circuit board 40. The extension portions 61a and 61b are provided on the surface 40 of the circuit board 40.
a and the back surface 40b.
The screw insertion holes 48 are opened on 1a and 61b.

Extension 61a of surface 40a of circuit board 40
When the screw 49 is tightened, the head 4
9a. The extension 61 b of the back surface 40 b of the circuit board 40 is in contact with the plating layer 57 that covers the seat 41 when the screw 49 is tightened. For this reason, the ground layer 46 of the circuit board 40 is also grounded to the housing 24 at a portion where the circuit board 40 is fixed to the housing 24.

According to such a configuration, since the extension portions 61a and 61b are formed in the plating layer 54, the ground layer 4 of the circuit board 40 is formed by the extension portions 61a and 61b.
The contact area between the housing 6 and the housing 24 increases. With it,
Since the extension 61b of the plating layer 54 is pressed against the seat 41 when the screw 49 is tightened, the contact between the extension 61b of the plating layer 54 and the plating layer 57 on the housing 24 side is improved.

Therefore, the ground layer 4 of the circuit board 40
6 can be reliably brought into contact with the housing 24, and the reliability of the ground connection is improved. FIGS. 5A and 5B disclose a third embodiment of the present invention.

The third embodiment differs from the first embodiment in the configuration of the ground connection portion between the circuit board 40 and the housing 24. Other configurations are the same as those in the first embodiment. This is the same as the embodiment. Therefore, also in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 5A, the circuit board 40
The first and second outer peripheral edges 50 and 51 have a linear shape along the peripheral wall 28 of the housing 24. The ground layer 46 of the circuit board 40 is exposed on the outer peripheral surface 40c of the circuit board 40 at a plurality of locations of the first and second outer peripheral edges 50 and 51. The exposed portion of the ground layer 46 extends along the longitudinal direction of the first and second outer peripheral edges 50, 51.

The first and second outer peripheral edges 50 and 51 including the outer peripheral surface 40c of the circuit board 40 are covered with a conductive plating layer 54. The plating layer 54 is formed at a position corresponding to the exposed portion of the ground layer 46, and is connected to the ground layer 46. And
The plating layer 54 is formed not only on the outer peripheral surface 40c of the circuit board 40, but also on the surface 4 of the circuit board 40 connected to the outer peripheral surface 40c.
0a and a part of the back surface 40b are continuously covered.

The housing 24 has a plurality of contact portions 71 on the inner surface of the peripheral wall 28. The contact portion 71 is connected to the circuit board 40
And is slightly projected from the inner wall surface of the peripheral wall 28 toward the inside of the housing 24. The contact portion 71 is covered with the plating layer 57.

The plating layer 57 covering the contact portion 71 is in contact with the plating layer 54 covering the first and second outer peripheral edges 50 and 51 when the circuit board 40 is accommodated in the housing 24. By this contact, the ground layer 4 of the circuit board 40 is
6 is grounded to the housing 24.

According to this configuration, the plating layer 54 on the circuit board 40 side is formed by the first and second plating layers of the circuit board 40.
The plating layer 54 extends along the longitudinal direction of the outer peripheral edges 50 and 51 of the circuit board 40.
Can be exposed over a wide range of the outer peripheral portions 50 and 51.

For this reason, the ground layer 46 of the circuit board 40 and the housing 2 are compared with the ground connection using the conventional boss.
4 can secure a sufficient contact area, and the electromagnetic noise shielding effect can be enhanced.

Further, since the first and second outer peripheral edges 50 and 51 of the circuit board 40 are covered with the conductive plating layer 54, electromagnetic noise from outside the housing 24 is protected from the outside of the circuit board 40. Intrusion into the peripheral edges 50 and 51 can be prevented. Therefore, the noise resistance of the circuit board 40 against external noise is improved, and a malfunction of the circuit can be avoided.

In the third embodiment, the plating layer 54 connected to the ground layer 46 is partially disposed on the first and second outer peripheral edges 50 and 51 of the circuit board 40. The present invention is not limited to this, and the plating layer 54 may be disposed over the entire length of the first and second outer peripheral portions 50 and 51.

In the first to third embodiments, a conductive plating layer is formed on the inner surface of a synthetic resin case to impart conductivity to the case. However, the present invention is not limited to this, and the housing itself may be made of a conductive metal material such as an aluminum alloy.

FIGS. 6 and 7 show a fourth embodiment of the present invention. In the fourth embodiment,
The circuit board 40 is housed in the housing 24 via a dedicated frame 81, and the housing 24 and the circuit board 4
The basic configuration of 0 is the same as that of the first embodiment. Therefore, in the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 6, the circuit board 40 in the present embodiment has a rectangular shape extending in the width direction of the housing 24. Therefore, the circuit board 40 has a front edge 80a and a rear edge 80b extending in the width direction of the housing 24. These edges 80a and 80b are linear and arranged in parallel with each other.

The front edge 80a has a single recess 82, and the rear edge 80b has a pair of recesses 83a, 83a.
3b. The recesses 82, 83a, 83b have the same configuration as each other. FIG. 7B shows the concave portion 83a.
As a representative example, the ground layer 46 of the circuit board 40 is
Are exposed on the inner surface 84 of the recess 83a. And
The inner surface 84 of the concave portion 83a is covered with the same plating layer 54 as in the first embodiment.

The frame 81 supporting the circuit board 40
Is made of a conductive metal material such as an aluminum alloy or a magnesium alloy. The frame 81 has such a size that it fits tightly inside the lower housing 25 of the housing 24.
1 itself is in contact with the plating layer 57 of the housing 24.

As shown in FIG. 6, the frame 81 has a substrate support 86. The substrate support 86 extends in the rear half of the frame 81 along the width direction of the housing 24, and the circuit board 40 is mounted on the upper surface of the substrate support 86. At four corners of the circuit board 40, screw insertion holes 87 are formed, respectively.
7, a screw 88 is inserted from above. Screw 88
Is screwed into the board supporting portion 86 of the frame 81, and the screwing fixes the circuit board 40 to the frame 81.

The board supporting portion 86 includes a front wall portion 90a extending along the front edge portion 80a of the circuit board 40 and a rear edge portion 80a.
b along the rear wall 90b. The front wall portion 90a and the rear wall portion 90b extend upward from the upper surface of the board support portion 86, and the inner wall faces the front edge portion 80a and the rear edge portion 80b of the circuit board 40.

A single conductive projection 91 is formed integrally with the front wall 90a. A pair of conductive protrusions 92a and 92b are integrally formed on the inner surface of the rear wall 90b. The conductive protrusions 91, 92a, and 92b constitute a conductive member separate from the housing 24, and have a thickness substantially equal to that of the circuit board 40.

The conductive convex portion 91 is provided in the concave portion 82 of the circuit board 40.
, And extends along the front edge 80a of the circuit board 40. The conductive convex portion 91 is fitted into the concave portion 82 of the circuit board 40 when the circuit board 40 is fixed to the board supporting portion 86. Conductive protrusion 92
a, 92b are arranged at positions corresponding to the concave portions 83a, 83b of the circuit board 40, and the rear edge 8
0b. These conductive projections 92a, 92
b, when the circuit board 40 is fixed to the board supporting portion 86,
The circuit board 40 is fitted into the concave portions 83a and 83b.

FIGS. 7B and 7C show the conductive projections 92.
As representatively shown as the fitting portion between the “a” and the concave portion 83a, the conductive convex portion 92a is tapered and has a projection 94 at its tip. The projection 94 abuts against the inner surface 84 of the concave portion 83a, and covers the inner surface 84 of the plating layer 5.
It touches 4.

The tip of the conductive projection 92a is
4 is soldered. The solder layer 93 obtained by this soldering is formed between the tip of the conductive projection 92a and the plating layer 54.
Is filled in the gap. Therefore, the conductive protrusion 9
2a is electrically connected to the plating layer 54,
Thus, the ground layer 46 of the circuit board 40 is grounded to the frame 81.

According to such a configuration, when the circuit board 40 is fixed to the board supporting portion 86 of the frame 81, the board supporting portion 86 is formed in the concave portions 82, 83a, 83b of the circuit board 40.
Of the conductive protrusions 91, 92a, and 92b are fitted. In this case, since the recesses 82, 83a, and 83b extend along the front edge 80a and the rear edge 80b of the circuit board 40, the plating layer 54 connected to the ground layer 46 of the circuit board 40 is The substrate 40 can be exposed over a wide range of the front edge 80a and the rear edge 80b.

Therefore, as compared with the conventional ground connection using the boss portion, the contact area between the ground layer 46 of the circuit board 40 and the frame 81 and thus the housing 24 can be sufficiently ensured, and the electromagnetic noise shielding can be achieved. The effect can be enhanced.

Since the front edge 80a and the rear edge 80b of the circuit board 40 are covered with the conductive plating layer 54, electromagnetic noise from outside the housing 24 is protected from electromagnetic noise from the outside of the circuit board 40. 80a and the rear edge 80b can be prevented from entering. Therefore, the noise resistance of the circuit board 40 against external noise is improved, and a malfunction of the circuit can be avoided.

Further, when the circuit board 40 is fixed to the board supporting portion 86 of the frame 81, the concave portions 82,
83a and 83b are conductive protrusions 91 and 92 of the substrate support 86.
a, 92b, these recesses 82, 83a,
The 83 b and the conductive projections 91, 92 a, 92 b function as positioning guides for the circuit board 40 with respect to the board support 86. As a result, the circuit board 40 can be accurately positioned on the board supporting portion 86 of the frame 81.

In the fourth embodiment, the conductive projection as the conductive member is formed integrally with the frame. However, the conductive member is not limited to the one formed integrally with the frame. For example, as seen in the first embodiment,
When the circuit board is directly fixed to the housing, one end of the conductive member is fitted into the recess of the circuit board, and the other end of the conductive member is brought into contact with the plating layer on the inner surface of the housing. good.

Further, in each of the above embodiments, the concave portion has an elongated shape along the outer peripheral portion of the circuit board. However, the present invention is not limited to this. A large number of recesses may be arranged at intervals, and a large number of recesses that fit into the recesses may be arranged at intervals on the housing or frame side.

Further, the electronic apparatus according to the present invention is not limited to a portable computer, but can be similarly applied to, for example, other home electric appliances equipped with a control circuit for generating electromagnetic noise.

[0097]

According to the electronic apparatus described in the first, fifth and seventh aspects, the conductive layer connected to the ground layer can be arranged over a wide range of the outer peripheral portion of the circuit board.
As compared with the conventional ground connection using the boss portion, a sufficient contact area between the ground layer of the circuit board and the housing can be secured. Therefore, the electromagnetic noise shielding effect is improved. In addition, the presence of the conductive layer can prevent electromagnetic noise from the outside of the housing from entering the outer peripheral portion of the circuit board, and improve the circuit board's noise resistance to external noise. In particular, according to the electronic device of the first aspect, the projections and the depressions function as positioning guides for the circuit board with respect to the housing, so that the position of the circuit board inside the housing is accurately determined, and The conductive layer can be reliably brought into contact with the housing.

[Brief description of the drawings]

FIG. 1 is an exemplary perspective view of a portable computer according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view showing a state where a circuit board is housed inside a housing in the first embodiment of the present invention.

FIG. 3A is a sectional view taken along line AA of FIG. 2;
(B) is sectional drawing which follows the BB line of FIG.

FIG. 4 is a sectional view showing a state in which a circuit board is housed inside a housing according to the second embodiment of the present invention.

FIG. 5A is a cross-sectional view showing a state where a circuit board is housed inside a housing in a third embodiment of the present invention. FIG. 6B is a cross-sectional view taken along the line CC of FIG.

FIG. 6 is an exploded perspective view showing a relationship between a frame and a circuit board in a fourth embodiment of the present invention.

FIG. 7A is a cross-sectional view showing a state where a circuit board is housed inside a housing. FIG. 8B is a cross-sectional view showing an enlarged part D of FIG. (C) is a perspective view showing a relationship between a concave portion of the circuit board and a convex portion of the frame.

FIG. 8 is a cross-sectional view showing a conventional circuit board ground connection structure.

9 is a view as seen from the direction of the line E in FIG. 8;

[Explanation of symbols]

24 ... housing 28 ... wall surface (peripheral wall) 40 ... circuit board 40c ... outer peripheral surface 44 ... insulating layer 45a, 45b ... signal wiring layer 46 ... ground layer 50, 51, 80a, 80b ... outer peripheral edge (first and second) 52 ... concave portion 54 ... conductive layer (plated layer) 56 ... convex portion 91, 92a, 92b ... conductive convex portion (conductive member)

Claims (10)

[Claims] 1. A circuit board comprising: an insulating layer; a signal wiring layer laminated on the insulating layer; and a ground layer disposed inside the insulating layer; A conductive housing having a wall surface facing the substrate; and a recess penetrating the circuit board in a thickness direction at an outer peripheral edge of the circuit board, and an inner surface of the recess formed on the inner surface of the recess. A conductive layer electrically connected to the ground layer is formed on an outer peripheral edge of the circuit board including the concave portion while exposing the ground layer, and is fitted into the concave portion on a wall surface of the housing. An electronic device, comprising: forming a conductive convex portion to be formed; and contacting the convex portion with a conductive layer of the circuit board. 2. The device according to claim 1, wherein the housing is
An electronic device made of synthetic resin, wherein a wall surface and a convex portion of the housing are covered with a conductive plating layer, and the conductive layer of the circuit board is in contact with the plating layer. . 3. The device according to claim 1, wherein the concave portions are arranged at a plurality of locations on an outer peripheral edge of the circuit board, and the convex portions are arranged at a plurality of locations on the wall surface. Electronic equipment. 4. The device according to claim 1, wherein the housing is
The seat has a seat for receiving the circuit board, and the circuit board is fixed to the seat via screws, and the recess of the circuit board is disposed at a position adjacent to the seat and covers the recess. The conductive layer has an extension extending to a position corresponding to the seat, and the extension is in contact with the seat when the circuit board is fixed to the seat. Electronics. 5. A circuit board, comprising: an insulating layer; a signal wiring layer laminated on the insulating layer; and a ground layer disposed inside the insulating layer; An electronic device comprising: a conductive casing having an inner surface facing the substrate; at least a part of the ground layer is exposed on an outer peripheral surface of the circuit board, and an outer peripheral edge of the circuit board including the outer peripheral surface; An electronic device, wherein a conductive layer electrically connected to the ground layer is formed in the portion, and the conductive layer is brought into contact with an inner surface of the housing. 6. The device according to claim 5, wherein the housing is
An electronic device comprising a synthetic resin, wherein an inner surface of the housing is covered with a conductive plating layer, and the conductive layer of the circuit board is in contact with the plating layer. 7. A circuit board having an insulating layer, a signal wiring layer laminated on the insulating layer, and a ground layer disposed inside the insulating layer; a circuit board containing the circuit board and A conductive housing having a wall surface facing the outer peripheral surface of the substrate; and a circuit board including at least a part of the ground layer exposed on the outer peripheral surface of the circuit board. A conductive layer electrically connected to the ground layer is formed on an outer peripheral edge of the housing, and a conductive member separate from the housing is interposed between the conductive layer and a wall surface of the housing. An electronic device, wherein the conductive layer is electrically connected to the housing via the conductive member. 8. The circuit board according to claim 7, wherein the circuit board has, on an outer peripheral edge portion including an outer peripheral surface thereof, a concave portion penetrating the circuit board in a thickness direction, and the ground layer is exposed on an inner surface of the concave portion. And the outer peripheral edge of the circuit board including the recess is covered with the conductive layer,
Further, the electronic device is characterized in that the conductive member is fitted in the recess and is in contact with the conductive layer. 9. The electronic device according to claim 7, wherein the conductive member is soldered to a conductive layer of the circuit board. 10. The circuit board according to claim 7, wherein the circuit board is housed in the housing via a metal frame, and the conductive member is formed integrally with the frame. Electronic equipment.