JP2002141618A - Flexible printed board and folding portable telephone terminal comprising it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shield a flexible printed board inexpensively by holding a conductor pattern between shield conductors without bonding the shield conductors to other insulating sheet. SOLUTION: The flexible printed board 1 comprises a first insulating sheet 12, a second insulating sheet 13, a conductor pattern 11 provided between the insulating sheets 12 and 13, and shield conductors bonded to the second insulating sheet 13 wherein the second insulating sheet 13 is folded along a crease so that the conductor pattern 11 is held between the shield conductors 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foldable portable device having a flexible printed board having a conductor for preventing noise fixed to an insulating sheet, and a flexible printed board having a conductor for preventing noise fixed to an insulating sheet. Regarding telephone terminals.

[0002]

2. Description of the Related Art Flexible printed circuit boards are widely used for moving parts of electronic equipment because of their excellent flexibility.

However, since a device using a digital circuit uses a clock pulse, it tends to emit pulse noise to the outside and thus tends to be a noise source. There are two types of noise propagation paths: radiated propagation in the air and conduction propagation in power and signal lines.When wiring is performed using a flexible printed circuit board, noise is conducted between the printed circuit boards by the flexible printed circuit board. Otherwise, there is a possibility that the flexible printed circuit board itself becomes an antenna, receives noise transmitted in the air, and propagates the noise to the printed circuit board.

[0004]

As a countermeasure against noise, there is a shielding method, but it is not easy to shield a flexible printed circuit board which is bent.

[0005]

SUMMARY OF THE INVENTION In view of the foregoing, a flexible printed circuit board according to the present invention has a first insulating sheet, a second insulating sheet, and a conductor provided between the two insulating sheets. A pattern and a shield conductor fixed to the second insulation sheet, wherein the second insulation sheet is bent so that the conductor pattern is disposed between the shield conductors Has folds.

Further, a foldable portable telephone terminal having a flexible printed circuit board according to the present invention comprises: a transmitting section; a receiving section;
A hinge section for rotatably connecting the transmitting section and the receiving section, and a first insulating sheet, a second insulating sheet, and both insulating sheets for electrically connecting the control section and the input section; And a flexible printed circuit board having a conductive pattern provided on the second insulating sheet and a conductor for shielding fixed to the second insulating sheet. Wherein the second insulating sheet is bent so that the conductor pattern is disposed on the flexible printed circuit board.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the front surface of the flexible printed circuit board (1) before bending before shielding, and FIG. 2 is a plan view showing the front surface after shielding. FIG. 3 is a plan view showing the back surface before bending. FIG. 4 is a plan view showing the bent flexible printed circuit board (1), and FIG. 5 is a right side view thereof.

In the flexible printed circuit board (1) before bending shown in FIG. 1, a conductor pattern (11) is vacuum-deposited on a first insulating sheet (12), and a contact and a contact are formed by a second insulating sheet (13). It is insulated except for a portion (described later).

The conductor pattern (11) has a thickness of about 40 μm.
And comprises a first pattern for ground (111), a second pattern for signal (112), and a third pattern for signal (113).

First and second insulating sheets (12) and (13)
Is a polyimide or polyester having a thickness of about 12.5 μm (half mill). Second insulating sheet (13:
The insulation by the diagonally shaded portions in FIGS. 1, 2, and 4) is achieved by the flexible printed circuit board (1) being a connector (2a in FIG. 6)
Tabs (111a) (111) connected to (3a in FIG. 6)
b) (112a) (112b) (113a) (113
b) and ground part for shield (111C) (111D)
Done.

As shown in FIG. 2, a second insulating sheet (1
Aluminum (14: a hatched portion in the lower right portion of FIGS. 2 and 4) is vacuum-deposited on the surface of 3). This aluminum (1
4) is for shielding, and the ground is grounded (11
1C) (111D) to form a first pattern (1
11) is electrically connected. Ground part (111C)
The position of (111D) is a tab (111) which is less affected by bending.
a) Two places are provided near (111b).

As shown in FIG. 3, an adhesive (double-sided tape) (15) is applied only to one tab side. And FIG.
The first insulating sheet (12) is folded inward along the fold line shown in FIG. When folded, the adhesive (15) makes it difficult for one tab side to be displaced in the direction perpendicular to the fold. First pattern for grounding (111)
The central part of the area occupied by the second pattern for signal (112) and the third pattern for signal (113) with respect to the fold
Are symmetrical with the center of the area occupied by. Therefore, in the folded state (FIG. 4), the central portions of these regions overlap. Thereby, the position of the center part of the conductor pattern (11) is set between the shielding aluminum (14) without depositing the shielding aluminum (14) on the first insulating sheet (12). Can be.

FIG. 6 is a partially transparent perspective view showing a state before assembling the flexible printed circuit board (1) into a portable telephone terminal, and FIG. 7 is a partially transparent perspective view showing a state after assembling.

A portable telephone terminal in which the flexible printed circuit board (1) is incorporated has a receiving section (4) and a transmitting section (5).
And a hinge type (6) for rotatably connecting the receiver (4) and the transmitter (5).

As shown in FIG. 6, the flexible printed circuit board (1) has the first connector (2a) of the first printed circuit board (2) and the second printed circuit board ( 3) is connected to the connector (3a). Then, as shown in FIG. 7, the flexible printed circuit board (1)
Is attached so that the spiral portion (rotated portion) of the mobile phone terminal enters the hinge portion (6) of the mobile phone terminal. As described above, by rotating the flexible printed circuit board (1) once at the hinge portion (6), the durability against opening and closing of the mobile phone terminal is improved (see Japanese Patent Application Laid-Open No. 1-89845).

By the way, when the mobile phone terminal is opened, the difference between the inner and outer radii of the spiral portion becomes larger, and when the mobile phone terminal is closed, the difference becomes smaller. Therefore, the flexible printed board (1) of the present invention does not have any folds in the hinge portion (6). As a result, the outside and the inside of the flexible printed circuit board (1) can relatively move in the hinge portion (6). Further, in order to prevent the folded flexible printed circuit board (1) from opening, a holding means is necessary. Since the flexible printed circuit board (1) of the present invention is bonded to only one tab side with an adhesive as a holding means, the difference between the inner and outer radii of the spiral portion at the time of opening and closing is determined by the other tab side. Can be somewhat absorbed.

Although the flexible printed circuit board of the above-described embodiment has one side, the present invention is not limited to this.

In the above embodiment, the conductor patterns overlap when the flexible printed circuit board is folded. However, in the present invention, it is not essential that the conductor patterns overlap, and the insulation on the side where the conductor is fixed is not essential. The sheet may be folded so that the position of the conductor pattern is between the conductors.

[0019]

As described above, in the flexible printed circuit board of the present invention, the conductor pattern can be positioned between the conductors without fixing the conductor for shielding to the other insulating sheet. Thereby, shielding can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a plan view showing a front surface of a flexible printed circuit board before bending according to an embodiment before a shielding process.

FIG. 2 is a plan view showing a front surface after shield processing.

FIG. 3 is a plan view showing a back surface of the flexible printed circuit board before bending.

FIG. 4 is a plan view showing the flexible printed circuit board in a bent state.

FIG. 5 is a right side view of FIG.

FIG. 6 is a partially transparent perspective view showing a state before a flexible printed circuit board is incorporated into a mobile phone terminal.

FIG. 7 is a partially transparent perspective view showing a state after being assembled in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible printed board 11 Conductor pattern 111 First conductor pattern 112 Second conductor pattern 113 Third conductor pattern 12 First insulating sheet 13 Second insulating sheet 14 Conductor 15 Adhesive 2 First printed board 3 Third printed circuit board 4 Receiver 5 Transmitter 6 Hinge

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Jiro Ozaki 3-201 Minamiyoshikata, Tottori-shi, Tottori Prefecture F-term in Tottori Sanyo Electric Co., Ltd. 5E321 AA17 BB23 BB44 GG05 5E338 AA02 AA12 AA16 BB54 CC01 CC05 CD12 CD23 CD40 EE13 EE32 5E348 AA03 AA18 AA28 EF36 5K023 AA07 DD08 LL01

Claims (2)

[Claims] 1. A first insulating sheet, a second insulating sheet, a conductor pattern provided between the two insulating sheets, and a shield conductor fixed to the second insulating sheet. A flexible printed circuit board comprising: a fold in which the second insulating sheet is bent so that the conductor pattern is disposed between the shield conductors. 2. A first insulating unit, comprising: a transmitting unit; a receiving unit; a hinge unit rotatably connecting the transmitting unit and the receiving unit; and a first insulating unit electrically connecting the control unit and the input unit. A foldable portable device including a sheet, a second insulating sheet, and a flexible printed board including a conductor pattern provided between the two insulating sheets and a shield conductor fixed to the second insulating sheet. A foldable portable telephone having a flexible printed circuit board, wherein the second insulating sheet is bent so that the conductor pattern is disposed between the shield conductors. Phone terminal.