JP2001284743A - Flexible printed board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of the electrical connection of first and second casings, which constitute communication equipment. SOLUTION: In a flexible printed board, the first casing and the second casing are electrically connected in communication equipment constituted of the first casing and the second casing connected to the first casing through a hinge. The board is provided with an electric wiring pattern which is installed on the flexible printed board and is constituted of a plurality of linear patterns where at least a part of the electric wiring pattern is formed along a prescribed direction and with a plurality of linear slits which pass through the flexible printed board and are formed along the prescribed direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a flexible printed circuit (Flex PCB).
oard), in particular, the first device and the second
The present invention relates to a flexible printed circuit board for electrically connecting first and second devices in a communication device to which the devices are coupled.

[0002]

2. Description of the Related Art FIG.
1 shows a partial schematic view of a general folding communication device 100. FIG. 2 is a partial exploded view for explaining the internal state of the portion shown in FIG. This type of communication device is an LCD
Device 11 having a display unit 108 (FIG. 1) composed of
0 and a second device 114 coupled to the first device 110 via a hinge 112. The second device 114 includes an operation unit 116 typified by a keyboard, a microcontroller, and other control units (not shown). The hinge portion 112 mechanically connects the first device 110 and the second device 114 rotatably. The hinge 112 allows the first device to be in the open and closed positions. Further, the first device 110 and the second
To electrically couple the device 114, the first device 110,
A flexible printed circuit board 118 (FIG. 2) is provided inside the hinge section 112 and the second device 114.

In such a communication device 100, in order to perform a desired operation, first, the first device 110 is rotated to an open position, and a desired operation is performed by the operation unit 116 on the second device 114. When the desired operation is completed, the first device 11
Rotate 0 to the closed position. Such a rotating operation is performed very frequently. For example, when the communication device 100 is a mobile phone, the desired operations include a call operation, an e-mail transmission operation, a message reception confirmation operation, a memory content correction, and the like. Needs to rotate the hinge part 112 at any time.

When the number of times of opening and closing the first device 110 increases,
That is, when the hinge 112 rotates frequently, stress is generated in the flexible printed circuit board 118 accommodated in the hinge 112 due to the rotation.
Even if the stress itself is small, if the number of times of opening and closing of the first device 110 becomes extremely large, there is a concern that the flexible printed circuit board may cause a disconnection failure or deteriorate the durability. You. That is, according to the related art, there is a problem that sufficient reliability cannot always be obtained due to the stress generated in the hinge portion 112.

[0005] The hinge portion 112 is flexible.
Since it is necessary to accommodate a part of the printed circuit board, it is necessary to increase the diameter of the hinge portion or to reduce the width of the accommodated flexible printed circuit board. For this reason, according to the related art, there is a problem that the degree of freedom in design regarding the thickness of the wiring, the arrangement of the wiring, and the width of the substrate is restricted.

Further, there is a demand to increase the number of signal lines from the viewpoint of improving the display capability of the communication device, and it is difficult to uniformly reduce the width of the flexible printed circuit board to be accommodated in the hinge portion. There are also problems.

[0007] Such a problem is particularly serious in a communication device that needs to be small.

[0008]

The above-mentioned problems can be solved by using a flexible printed circuit board described below. The flexible printed circuit board is provided with an electric wiring pattern composed of a plurality of linear patterns formed at least partially along a predetermined direction, and further penetrates the flexible printed circuit board, and is provided in the predetermined direction. A plurality of linear slits are formed along the groove.

[0009]

FIG. 3 is an exploded view of a flexible printed circuit board 300 according to the present invention. This flexible printed circuit board 300 is a communication device in which a first device and a second device are rotatably connected by a hinge portion.
This is for electrically connecting the first device and the second device. An electric wiring pattern 310 is provided on the flexible printed circuit board 300. At least a part of the electric wiring pattern 310 forms a plurality of linear patterns 312 parallel to a predetermined direction 320. The linear pattern 312 includes various signal lines for electrically connecting the first device and the second device of the communication device. In this embodiment, a ground line 315 is included in these linear patterns. Further, a plurality of groove-shaped linear slits 314 penetrating the flexible printed board 300 and parallel to a predetermined direction are formed in the flexible printed board 300. The linear pattern 312 is located at a place where these linear slits 314 are not formed. This linear slit can be formed by various methods, for example, it can be formed by punching. Also,
The length and width of the linear slit and the interval between the linear slits are appropriately determined depending on the flexibility and thickness of the flexible printed circuit board 300, the inner diameter of the hinge 612 (FIG. 6), and the like. One end of the linear pattern 312 is connected to the first device connection portion 322, and the other end is connected to the second device connection portion 324. The first device connection section 322 includes:
A plurality of linear patterns 312 arranged on one plane are
It is for electrically connecting to the device. Similarly, the second device connection portion 324 is for electrically connecting the plurality of linear patterns 312 arranged on one plane to the second device.

FIG. 4 is a perspective view of the flexible printed circuit board 300 shown in FIG.
FIG. 2 is a schematic view showing a state where the sheet is folded so as to be wound around a circle. In this embodiment, the sheet is first folded along the first linear slit 314 at the top in FIG. 3, and is successively folded along the second, third, etc. linear slits. The portion indicated by reference numeral 450 is the reference numeral 3 in the developed view of FIG.
It corresponds to the portion indicated by 50. When bending the flexible printed circuit board 300, it is possible to appropriately change which side is the inner side depending on the application.
In this manner, the flexible printed circuit board 300 is bent along the predetermined axis 321 so that the linear slit 314 is located at the bent portion. In other words, the flexible printed circuit board 30 is arranged such that every other linear slit 314 in the developed view of FIG.
0 is bent. In this embodiment, the flexible printed circuit board 300 is bent so as to be wound around a predetermined axis. However, various bending methods can be considered. . This is because the plurality of slits 314 may be overlapped with each other finally (after folding).

FIG. 5 shows a flexible printed circuit board 30.
The flexible printed circuit board 3 is bent as shown in FIG.
FIG. 4 shows a schematic diagram of a further modified version of 00. The portion indicated by reference numeral 450 in FIG. 4 is deformed into a U-shape as shown in FIG. The stress in the flexible printed circuit board 300 generated due to this deformation processing is extremely small. If the linear slit 314
Fig. 4 shows a flexible printed circuit board without
If it is bent around a predetermined axis as shown in FIG. 5 and further deformed into a U-shape as shown in FIG. 5, the stress generated by this deformation will be extremely large. If the internal stress is large, there is a concern that the reliability of the electrical connection is adversely affected. However, in this embodiment, since the linear slits 314 are provided so as to overlap each other (FIG. 4), the flexible printed circuit board can be deformed as shown without applying excessive stress. is there.

FIG. 6 is a partial schematic diagram of the case where the flexible printed circuit board 300 deformed as shown in FIG. The communication device 600 includes a first device 610 having a display unit 608 composed of an LCD or the like and a speaker 609,
A second device 614 coupled to the device 610 via a hinge 612. The second device 614 includes an operation unit (not shown) typified by a keyboard, a microcontroller and other control units (not shown), and the like. The hinge 612 rotatably mechanically couples the first device 610 and the second device 614. This hinge part 6
12 allows the first device 610 to be in the open and closed positions. First device 610 and second device 614
Is electrically connected to the flexible printed circuit board 300 according to the present invention. In the hollow area inside the hinge part 612, a folded and deformed flexible
A part of the printed circuit board 300 is inserted. As shown, the predetermined axis 321 of the flexible printed circuit board 300 is arranged so as to coincide with the rotation axis of the hinge 612. The respective devices are electrically coupled via the first device connection portion 322, the electric wiring pattern 310, and the second device connection portion 324.

When opening and closing the first device 610, the U-shaped portion of the flexible printed circuit board 300 remains fixed. Therefore, the first
The effects such as the slack of the flexible printed circuit board 300 which may be caused by the opening and closing of the device 610 are indicated by reference numeral 460.
It is possible to absorb by giving a margin to the size of the portion shown in FIG. 6 and FIG.

As a specific example of the dimensions of the flexible printed circuit board, when the inner diameter of the hinge is about 6 mm, the thickness of the flexible printed circuit board 300 is about 0.1 mm.
The length and width of the linear slit 314 are each 60 mm
And about 1 mm, the interval between the linear slits 314 is 5 m
m, the width of the first and second device connecting portions 322, 324 can be about 20 mm, and the length of the portion indicated by the reference numeral 450 can be about 50 mm. Thus, the flexible printed circuit board 300 can be folded very small.

By the way, when the flexible printed circuit board 300 folded as shown in FIG. 5 is employed, there is a concern that signal noise may occur between signal lines in an electric wiring pattern. One technique for solving this problem is a signal line (linear pattern) that generates signal noise.
Between the ground lines. FIG. 7 is a partial cross-sectional view of a wound flexible printed circuit board 300 when such a method is employed. In this figure, linear slits 314 are located in the left and right regions of each signal line. Each signal line includes a ground line 710, a noise-generating signal line 712, and a ground line
Line 714, signal line 71 that is susceptible to noise
6,718 and the ground line 720. By thus sandwiching the signal line between the ground lines, it is possible to suppress the influence of signal noise. In order to realize such a signal line arrangement, in the developed view of FIG.
At least two of the plurality of linear patterns 312 may be ground lines 315, and two or more linear slits 314 may be formed between these two ground lines 315. The specific numbers of the ground lines and the linear slits can be appropriately selected depending on the use of the flexible printed circuit board 300, the bending method, and the like.
The reason is that it is only necessary that the signal line is finally sandwiched between the ground lines.

However, in order to realize the signal line arrangement as shown in FIG. 7 without folding one flexible printed circuit board 300 as in this embodiment, it is also conceivable to adopt a multilayer flexible printed circuit board from the beginning. Can be
Certainly, it is theoretically possible to suppress the influence of signal noise by using a multilayer flexible printed circuit board. However, when a multilayer flexible printed circuit board is adopted, the first device 610 and the second device 6
A dedicated connection portion (connector) for connecting each substrate to 14 is required. According to the present embodiment, such a dedicated connection is not required, and an inexpensive connection for connecting electric patterns arranged in parallel on one plane is employed, while the effect of signal noise is effectively suppressed. It is possible.

According to the flexible printed circuit board of the present embodiment, since a plurality of slits are formed through the board along a predetermined direction, the flexible printed circuit board is folded along the slits. The substrate can be deformed into a U-shape. Therefore, it is possible to solve the problem that the reliability of the electrical connection is not always sufficient due to the rotation of the hinge portion. Further, since the flexible printed circuit board according to the present embodiment can be folded and deformed in a small size, the degree of freedom in design, which is a problem in the related art, is reduced. Further, even if the number of signal lines requiring electrical connection increases, it is not necessary to immediately increase the width between the slits, so that it is possible to meet the demand for an increase in the number of signal lines.

Although the present invention has been described with reference to a particular embodiment, it is not intended that the invention be limited to that embodiment. INDUSTRIAL APPLICABILITY The present invention can be widely applied to a device having a first device and a second device, in which the first and second devices are mechanically connected rotatably and also electrically connected. It is possible. Such devices having first and second devices include cell phones, electronic organizers, notebook computers, and other electronic devices.

[Brief description of the drawings]

FIG. 1 is a partial schematic view of a foldable communication device.

FIG. 2 is a partial exploded view of a conventional folding communication device.

FIG. 3 is a development view of a flexible printed circuit board according to the present invention.

FIG. 4 is a schematic view showing a state in which a flexible printed board according to the present invention is folded.

FIG. 5 is a schematic diagram showing a state in which a further modification is performed from the state shown in FIG. 4;

FIG. 6 is a partial schematic view when a flexible printed circuit board according to the present invention is employed in a communication device.

FIG. 7 is a schematic cross-sectional view showing a signal line arrangement for preventing signal noise in the wound flexible printed circuit board.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Foldable communication device 108 Display 110 First device 112 Hinge part 114 Second device 116 Keyboard (operation unit) 118 Flexible printed board 300 Flexible printed board 310 Electric wiring pattern 312 Linear pattern 314 Linear slit 315 Ground Line 320 Arrow 321 indicating a predetermined direction 321 Arrow indicating a predetermined axis 322 First device connection 324 Second device connection 600 Foldable communication device 608 Display 609 Speaker 610 First device 612 Hinge 614 Second apparatus

Claims (7)

[Claims] 1. A flexible device for use in a communication device comprising a first device and a second device coupled to the first device via a hinge, and electrically connecting the first device and the second device. A printed circuit board, wherein an electric wiring pattern provided on the flexible printed circuit board, wherein at least a part of the electric wiring pattern includes a plurality of linear patterns formed along a predetermined direction; A flexible printed circuit board comprising: a wiring pattern; and a plurality of linear slits penetrating the flexible printed circuit board and formed along the predetermined direction. 2. The flexible printed circuit board according to claim 1, wherein, when the flexible printed circuit board is bent in parallel to the predetermined direction, the linear slit is located at the bent portion. 3. The flexible printed circuit board according to claim 1, wherein at least one of the plurality of linear patterns is a ground line. 4. The method according to claim 1, wherein at least two of the plurality of linear patterns are ground lines, and two or more linear slits are formed between the two ground lines. Item 7. A flexible printed circuit board according to item 1. 5. The flexible printed circuit according to claim 1, wherein the predetermined direction is parallel to a hinge axis of the hinge. 6. The flexible device according to claim 1, wherein the first device connecting portion connected to one end of the electric wiring pattern and the second device connecting portion connected to the other end of the electric wiring pattern.
2. The flexible printed circuit board according to claim 1, wherein the flexible printed circuit board is provided at a predetermined location around the printed circuit board. 7. The flexible printed circuit board according to claim 1, wherein at least one of the one end or the other end of the electric wiring pattern is formed of a plurality of linear patterns arranged on one plane. .