JP2009212977A - Ground contact structure of circuit board, and electronic apparatus - Google Patents

Abstract

The present invention provides a ground contact structure for a circuit board in which conduction between the circuit board and a sheet metal is stabilized, and an electronic device using the same.
A circuit board 33, a case 4a surrounding the circuit board 33, a contact spring terminal 32 mounted on the circuit board 33, and a sheet metal integrally formed with a part exposed inside the case 4a. 31, and a ground contact structure of the circuit board 33 in which the contact spring terminal 32 and a part of the sheet metal 31 are arranged to be in contact with each other.
[Selection] Figure 8

Description

  The present invention relates to a circuit board ground contact structure and an electronic device capable of stably obtaining electrical conduction between a circuit board and a sheet metal (shield metal sheet) without causing an increase in contact resistance.

In portable terminals such as mobile phones and PHS (Personal Handy-phone System) that are required to be lighter and thinner, in general, in order to achieve contact conduction between the circuit board in the housing and the shield sheet metal, a conductive tape A material with a small thickness such as (copper foil tape) is used. When this conductive tape was used, the contact conduction between the circuit board and the shield metal plate was taken only by the adhesive force of the tape.
For example, Patent Document 1 discloses that a ground contact portion is formed by adhering a conductive adhesive tape or applying a conductive adhesive between a circuit board and a sheet metal frame.
JP 2006-84969 A

However, in the conventional ground contact structure between the circuit board and the shield sheet metal using the conductive tape or conductive adhesive, conduction was obtained only with the adhesive force of the tape or adhesive, so the positional relationship between the two was slightly shifted. However, the contact state becomes unstable and the contact resistance may increase.
In addition, there is a problem that the conductive tape or the like has to be affixed manually, and the assembly work is complicated and the number of work steps is increased. Furthermore, it was difficult to confirm whether or not it was correctly attached.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a ground contact structure of a circuit board and an electronic device in which conduction between the circuit board and the sheet metal is stabilized.

The circuit board ground contact structure and electronic apparatus according to the present invention employ the following means in order to solve the above problems.
A ground contact structure for a circuit board according to a first aspect of the present invention includes a circuit board, a case surrounding the circuit board, a contact spring terminal mounted on the circuit board, and a part exposed inside the case. The contact spring terminal and a part of the sheet metal are arranged to face each other and come into contact with each other.

  By adopting such a configuration, even if the positional relationship between the circuit board and the sheet metal is slightly deviated, conduction is ensured by the elastic force of the spring, and a stable low ground contact resistance can be ensured.

The contact spring terminals are provided in a plurality on the circuit board.
By adopting such a configuration, it is possible to ensure conduction with the circuit board even in a narrow contact region, and to ensure a stable low ground contact resistance.

Further, the case is characterized in that a claw portion for locking and fixing the circuit board is provided.
By adopting such a configuration, the case can be securely held by the case and the elastic reaction force of the contact spring terminal can be suppressed by the claw portion.

Further, the case is characterized in that claw portions for locking and fixing the circuit board are provided at positions corresponding to both ends in the width direction of the circuit board.
By adopting such a configuration, it is possible to reliably hold the circuit board with the claw portion and appropriately press the sheet metal against the contact spring terminal to obtain stable conduction.

Further, the claw portion and the contact spring terminal are arranged on a straight line.
By adopting such a configuration, it is possible to obtain stable conduction by pressing the metal plate against the contact spring terminal in a balanced manner.

  A second invention includes a circuit board, a casing made up of a front case and a rear case surrounding the circuit board, and a sheet metal integrally formed by exposing a part inside the front case. In the electronic apparatus, the circuit board ground contact structure according to the first invention is used as a ground contact structure between the circuit board and the sheet metal.

  By adopting such a configuration, it is possible to ensure conduction between the circuit board and the sheet metal and to secure a stable low ground contact resistance. Moreover, the workability | operativity in an assembly process can be aimed at.

According to the present invention, the following effects can be obtained.
Even if the positional relationship between the circuit board and the sheet metal is slightly deviated, it is possible to ensure conduction by the elasticity of the spring and ensure a stable low ground contact resistance.
Moreover, the workability | operativity in an assembly process can be aimed at.
Furthermore, since the contact spring terminal is received by the front case integrally formed with the sheet metal, it is possible to prevent the case from being deformed by the reaction force of the spring.

Embodiments of a ground contact structure for a circuit board and an electronic apparatus according to the present invention will be described below with reference to the drawings.
In the following description, a portable terminal such as a PHS terminal will be described as an example of an electronic device.

FIG. 1 is a perspective view showing an appearance of a PHS terminal A according to an embodiment of the present invention.
The PHS terminal A is of a folding type in which the display side main body 1 and the operation side main body 2 are connected by a hinge structure 3.
In the following description, the surfaces where the PHS terminal A is folded by the hinge structure 3 and the display-side main body 1 and the operation-side main body 2 are in contact with or face each other will be described as the display-side facing surface 1a and the operation-side facing surface 2a, respectively. There is a case.

The display-side body 1 is the same as the display unit 5, the display-side housing 4 that forms the exterior of the display-side body, the display unit 5 that is provided on one surface (display-side facing surface 1 a) of the display-side housing 4. The earpiece 6 is provided above the display unit 5 on the surface.
The display-side housing 4 forms the exterior of the display-side main body 1, and constitutes the back side of the display-side main body 1 with respect to the front case 4a that constitutes the display-side facing surface 1a and the display-side facing surface 1a. Rear case 4b.
The front case 4a and the rear case 4b can be coupled to each other in the thickness direction of the display-side main body 1.

The display unit 5 is formed of, for example, a liquid crystal display or an organic EL (Electro Luminescence), and displays a desired image, character, or the like, and is provided by being fitted to a substantially central portion of the display-side housing 4. .
The earpiece 6 is disposed above the display unit 5 and communicates with a speaker (not shown) provided in the display-side housing 4 and the outside.

  The operation side main body 2 includes an operation side housing 7 that forms an exterior of the operation side main body 2, an operation unit 8 provided on one surface of the operation side housing 7 (operation side facing surface 2a), and an operation unit. 8 and a mouthpiece 9 provided on the same plane and below the operation unit.

The operation-side casing 7 forms an exterior of the operation-side main body 2, and the opposite surface side of the operation-side main body 2 with respect to the front case 7 a constituting the operation-side facing surface 2 a and the operation-side facing surface 2 a. The rear case 7b is configured.
The front case 7a and the rear case 7b can be coupled to each other in the thickness direction of the operation-side main body 2. The operation unit 8 includes a power key, a numeric keypad, and various function keys, and is configured to receive various operation instructions from the user. The mouthpiece 9 is arranged below the operation unit 8 and is configured to communicate with a microphone (not shown) provided in the operation-side casing 7.

FIG. 2 is a functional block diagram showing a main functional configuration of the PHS terminal A according to the embodiment of the present invention.
Here, the PHS terminal A has a communication unit 10 having an antenna (antenna element) 20 connected therein and a control unit 11, and the communication unit 10, the operation unit 8, and the display unit 5 are the control unit 11. It is configured to be connected to.

  The communication unit 10 is configured to transmit / receive various control signals and data signals to / from a base station (not shown) via the antenna 20 and output received information to the control unit 11 under the control of the control unit 11. Yes. The antenna 20 is a built-in antenna that is provided inside the operation-side main body 2 and includes an antenna conductor that transmits and receives radio waves and a dielectric.

  The control unit 11 inputs and outputs signals to and from the internal memory including a CPU (Central Process Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and the communication unit 10, the operation unit 8, and the display unit 5. Each of them is composed of an interface circuit and the like, and is configured to control the overall operation of the PHS terminal A based on a control program stored in the ROM. For example, the control unit 11 can receive a signal input from the operation unit 8 and cause the display unit 5 to display a predetermined image or cause the communication unit 10 to start operations such as data transmission / reception.

3 is an exploded perspective view showing members constituting the display-side main body 1 of the PHS terminal A of the present invention, and FIG. 4 is an exploded perspective view of the members constituting the display-side main body 1 as seen from the reverse direction.
3 and 4, for convenience of explanation, the front case 4a and the sheet metal 31 are described as separate bodies. However, as shown in FIGS. 5 and 6, the front case 4a and the sheet metal 31 are actually It is integrally formed by insert molding.

  The display-side main body 1 is formed of a liquid crystal display, an organic EL, or the like, and includes a display unit 5 that displays images, characters, and the like, a storage recess 30 that stores the display unit 5, and a sheet metal 31 that is insert-molded. A case 4a; a circuit board 33 that contacts the sheet metal 31 through a contact spring terminal 32 to establish conduction; and a rear case 4b that fits the front case 4a and surrounds the circuit board 33 and the like. It has a configuration.

  The display unit 5 includes a liquid crystal panel 51 and a frame 52 for fixing the liquid crystal panel, and a locking claw 53 for attachment is provided on the frame 52. The display unit 5 is mounted in the storage recess 30 of the front case 4a, and a locking claw 53 is locked in a locking hole 41 formed in the front case 4a.

  The front case 4a has a hinge structure 3 at the lower end, is formed so as to be rotatable with the operation side main body 2, and a sheet metal 31 is integrally formed by insert molding.

FIG. 5 is a three-side view showing the front case 4a constituting the display-side main body. FIG. 6 is a perspective view of the front case 4a as seen from the front view side.
The sheet metal 31 is a member having conductivity, and suppresses interference between electronic articles due to noise, electromagnetic waves, or the like generated from the electronic article. The sheet metal 31 is formed integrally with the front case 4a to improve the mechanical strength of the thin display-side main body 1.
Further, the sheet metal 31 is formed with a housing recess 30 in accordance with the shape of the display unit 5, and the periphery rises to form a wall-shaped portion 31 b. In addition, the wall-like portions 31b at the upper and lower ends in the longitudinal direction of the sheet metal 31 form a receding portion 31a that extends horizontally and recedes in a direction away from the adjacent circuit board 33. Is assembled between the upper and lower ends of the circuit board 33, and an enclosure space for the contact spring terminal 32 is formed.
The front case 4a includes claw portions 34 for locking the circuit board 33 at positions corresponding to both left and right (width direction) ends of the circuit board 33. Further, the front case 4a corresponds to each of the contact spring terminals 32 in order to bring the contact spring terminal 32 into contact with the circuit board 33 to a part (the contact portion 31c) of the receding portion 31a of the sheet metal 31. A protruding hole 40 is formed at the position.

On the circuit board 33, a graphic controller, a light source driver, a semiconductor element for driving liquid crystal, and the like (not shown) are mounted, and a pair of contact spring terminals 32 are mounted on the side facing the sheet metal 31.
The mounting position of the contact spring terminal 32 is a position facing the retreating portion 31 a (contact portion 31 c) of the sheet metal 31 and outside the enclosed space. Moreover, the nail | claw part 34 and the spring terminal 32 for contact are arrange | positioned on the straight line (refer FIG. 8).

FIG. 7 is an explanatory view showing a state where the circuit board 33 is attached to the front case 4 a of the display-side main body 1.
The circuit board 33 is locked and fixed on both sides by a claw portion 34 erected from the front case 4a. Therefore, even if the repulsive force of the contact spring terminal 32 is applied to the circuit board 33, the circuit board 33 can be stably held.
Further, the claw portion 34 formed at the upper end of the front case 4 a and the contact spring terminal 32 mounted on the circuit board 33 side are arranged in a straight line, so that the circuit board 33 is located with respect to the contact spring terminal 32. Can be pressed in a well-balanced manner and good conduction can be obtained.

FIG. 8 is a view showing the relationship between the contact spring terminal 32 mounted on the circuit board 33 and the sheet metal 31, and is a cross-sectional view taken along line AA and BB in FIG.
The contact spring terminal 32 mounted on the circuit board 33 with the flat base end portion 32a is brought into conduction by the contact portion 32c rising in a semicircular shape and the retreating portion 31a (abutting portion 31c) of the sheet metal 31 coming into contact therewith. be able to.
Here, since the circuit board 33 and the receding portion 31a (abutting portion 31c) of the sheet metal 31 are arranged at an interval narrower than the thickness of the contact spring terminal 32, the contact portion 32c is caused by an appropriate elastic force. If the positional relationship between the circuit board 33 and the sheet metal 31 is shifted, the contact failure does not occur.

FIG. 9 is an enlarged perspective view showing the contact spring terminal 32.
The contact spring terminal 32 includes a flat base end portion 32a attached to the circuit board 33, a folded portion 32b rising from the base end portion 32a in a U-shape, and a contact rising further semicircularly from the folded portion 32b. Part 32c. The contact spring terminal 32 is made of a member having elasticity and conductivity such as metal.
Therefore, when the base end portion 32a is fixed on the substrate, the folded portion 32b and the contact portion 32c are elastically deformed to obtain an appropriate contact pressure.

Next, in the circuit board ground contact structure configured as described above, the display-side main body 1 is assembled as follows.
First, the display unit 5 is attached and fixed to the storage recess 30 of the front case 4a from the front side by a locking claw 53 erected on the frame 52.
Subsequently, the circuit board 33 is locked by a claw portion 34 erected on the inner side of the front case 4a. At this time, the insulating sheet 50 is disposed between the sheet metal 31 and the circuit board 33 which are integrally fixed to the inside of the front case 4a. However, the insulating sheet 50 is not disposed at the portion where the contact spring terminal 32 of the circuit board 33 is mounted.

Moreover, the area | region corresponding to the site | part in which the contact spring terminal 32 of the circuit board 33 is mounted in the sheet metal 31 becomes the retreat part 31a, the folding | returning part 32b of the contact spring terminal 32, and a semicircle contact The part 32c is elastically deformed moderately to ensure conduction.
Furthermore, since the sheet metal 31 has the retracted portions 31a at the upper and lower ends so as to wrap the display portion 5, the stroke of the contact spring terminal 32 can be ensured while the display-side main body 1 is thinned.
In addition, no conductive tape is required for assembly, and the number of work steps can be reduced.

Finally, the rear case 4b is attached to the front case 4a to complete the display-side body 1.
Furthermore, the PHS terminal A is completed by connecting the display side main body 1 and the operation side main body 2 via the hinge structure 3.

  In the above embodiment, an example in which a pair of contact spring terminals 32 are disposed at close positions has been described. However, the contact spring terminals 32 may be disposed at positions away from the circuit board 33. Good.

  In addition, a portable terminal such as a PHS terminal has been described as an example of the electronic device, but the present invention is not limited to this. Any electronic device that requires conduction between the circuit board and the sheet metal (shield sheet metal) may be used. In particular, the present invention can be applied to portable portable electronic devices such as PDAs (Personal Digital Assistants), digital cameras, digital video cameras, and notebook personal computers.

It is a perspective view which shows the external appearance of the PHS terminal in one embodiment of this invention. It is a functional block diagram which shows the principal part function structure of a PHS terminal. It is a disassembled perspective view which shows the member which comprises a display side main body. It is the disassembled perspective view which looked at the member which comprises a display side main body from the reverse direction. It is a three-view figure which shows a front case. It is a front perspective view which shows a front case. It is explanatory drawing which shows the state which attached the circuit board to the front case. It is a figure which shows the relationship between the spring terminal for a contact mounted in the circuit board, and a sheet metal. It is an expansion perspective view which shows the spring terminal for contact.

Explanation of symbols

A ... PHS terminal (electronic equipment)
DESCRIPTION OF SYMBOLS 1 ... Display side main body 4 ... Display side housing | casing (casing)
4a ... Front case (case)
4b ... Rear case 5 ... Display part 30 ... Storage recess 31 ... Sheet metal 31a ... Retraction part 31c ... Abutting part 32 ... Contact spring terminal 33 ... Circuit board 34 ... Nail part

Claims (6)

A circuit board;
A case surrounding the circuit board;
A contact spring terminal mounted on the circuit board;
A sheet metal integrally formed with a part exposed inside the case, and
A ground contact structure for a circuit board, wherein the contact spring terminal and a part of the sheet metal are disposed to face each other.   2. The circuit board ground contact structure according to claim 1, wherein a plurality of the contact spring terminals are provided on the circuit board.   The ground contact structure for a circuit board according to claim 1, wherein the case includes a claw portion for locking and fixing the circuit board.   The said case provided the nail | claw part which latches and fixes the said circuit board in the position corresponding to the width direction both ends of the said circuit board, The Claim 1 characterized by the above-mentioned. Circuit board ground contact structure.   5. The circuit board ground contact structure according to claim 3, wherein the claw portion and the contact spring terminal are arranged on a straight line. 6. In an electronic apparatus comprising: a circuit board; a housing formed of a front case and a rear case surrounding the circuit board; and a sheet metal integrally formed by exposing a part inside the front case.
6. An electronic apparatus using the circuit board ground contact structure according to claim 1 as a ground contact structure between the circuit board and the sheet metal.

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