JP3544930B2 - Flexible printed circuit board and electronic device using the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flexible printed circuit board (hereinafter, simply referred to as FPC), and more particularly to an FPC for a two-part electronic device, such as a portable electronic device, connected by a hinge and an electronic device using the same.
[0002]
[Prior art]
2. Description of the Related Art There are various types of portable electronic devices such as a notebook personal computer, a portable information terminal, a mobile phone, and a video camera, each of which has a configuration in which a device case is connected with a hinge, for example, a display portion and a main body. The hinge has a mechanical connection structure and a built-in FPC for electrical connection. This constitutes a small and lightweight hinge.
[0003]
[Problems to be solved by the invention]
In this case, there is a method of using two single-sided FPCs and arranging them in an overlapping manner so as not to widen the plane.
[0004]
However, in the method of using two single-sided FPCs, two connectors are required for the mating substrate to be connected, and the number of components increases, and the assembling time is required. Therefore, there is a method of using a double-sided FPC having a wiring pattern on both sides. However, double-sided FPC is less flexible than single-sided FPC. This is due to the structure of the double-sided FPC. Since the through-hole plating is applied, the wiring patterns on both sides are pulled through the insulating base portion every time it bends, and disconnection due to repeated stress occurs. not many.
[0005]
There is a problem that the required number of times of bending cannot be realized even with a device that performs through-hole plating only on the inner wall of the through-hole and the through-land.
[0006]
The present invention has been made in consideration of the above points, and an object of the present invention is to provide an FPC which has a single structure, can secure a required number of wires, and has excellent flexibility.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention provides:
A flexible printed circuit board comprising a pair of terminals provided at each end of the flexible substrate and a wiring portion connecting between these terminals, wherein the flexible substrate is configured to be bendable.
The wiring portion is formed as two portions having a space therebetween, and has a bent fold in a direction crossing a direction in which the wiring extends,
The folded fold includes peaks and valleys as viewed from one surface of the flexible printed board, and is configured to be foldable along the folded fold,
A flexible printed circuit board, wherein the wiring portion on the bending outer peripheral side is configured to be longer in the bending circumferential direction than the wiring portion on the bending inner peripheral side,
Is provided.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 and 2 are explanatory views of an FPC to which the present invention is applied. FIGS. 3 to 6 are front views showing the form of the two embodiments of the present invention when the FPC is deployed and when the FPC is bent. FIGS. 3 and 4 show a first embodiment, and FIGS. 5 and 6 show a second embodiment, respectively.
[0009]
FIG. 1 has terminals 11 and 12 at the upper end and the lower end in the drawing, and the two terminals are connected to each other by two wiring portions 21 and 22 having a detour shape with a space between them. Although not shown, the wiring pattern is formed so as to connect the terminal portions 11 and 12 to each other. Folded folds 31 and 32 are formed at a substantially intermediate position between the wiring portions 21 and 22 in a direction intersecting the direction in which the wirings extend, and the folds 31 and 32 are bent so that the folds 31 and 32 become valleys. The wiring portions 21 and 22 are folded along the folds 31 and 32 so as to overlap each other.
[0010]
FIG. 2 shows a state after the FPC shown in FIG. 1 is bent. In this state, another wiring portion 22 is hidden behind the wiring portion 21 and is in a state of being incorporated into an electronic device. That is, the detour shape and the space shape of the wiring portions 21 and 22 are determined so as to conform to the shape in the state of being incorporated into the electronic device, in other words, to avoid other components.
[0011]
In the case shown in the figure, there is another component immediately below the upper terminal 11, and a large detour is performed to avoid the component, and then the component is turned toward the lower terminal 12. The outline after bending is formed by the terminals 11 and 12 and the wiring portion 21, and the back side of the folded folds 31 and 32 between the wiring portion 21 and the wiring portion 22 (not shown) can be seen.
[0012]
The wiring portion 21 (22) is used so as to be wound about one turn in the vertical direction in the figure to form a loop in the middle. At this time, the wiring portions 21 (22) are formed in a meandering shape so that the wiring portions do not interfere with each other. At this time, the wiring portions 21 and 22 are subjected to an elongating action if they are outside the wrapping, and are subjected to a reducing action if they are inside the wrapping.
[0013]
Since it is not preferable that the bent portions 31 and 32 provided in the middle of the wiring portions 21 and 22 receive their action, it is necessary to consider the position of the bent portions 31 and 32 in the wiring portions 21 and 22. There is.
[0014]
FIG. 3 is a development view showing an embodiment of the present invention. In this embodiment, the folded fold 32 in FIGS. 1 and 2 is modified so as to reduce the folded shape of the FPC shown in FIGS. That is, the folded fold 32 'between the wiring portions 21 and 22 is formed in a mountain shape, while the folded fold 32 in FIGS. Then, valley-shaped bent folds 33a and 33b are formed diagonally on both sides of the folded fold 32 'so as to form a V-shape, so that a four-layer fold is possible.
[0015]
In this folding structure, by combining the folding of the mountain fold and the valley fold, there is a difference between the inner and outer circumferences of the flexible printed circuit board on the outside and the flexible printed circuit board on the inside at the time of assembling into the electronic device, thereby increasing the flexibility. be able to. This is based on the fact that the length of the flexible printed circuit board on the outside and the inside on the inside is changed by adjusting the bending position.
[0016]
FIG. 4 shows a state in which the folded folds 32 ', 33a, and 33b are folded. After being folded in this manner, the back side of the folded fold 33a is in a visible state, and the portions of the wiring portions 21 and 22 closer to the folded fold 32 'than the folded folds 33a and 33b are not seen as shown by broken lines.
[0017]
Here, only the lower folding fold has a four-layer folding structure, but the upper folding fold 31 may have a folding structure in the same manner. And the escape margin for other parts increases by the amount of folding.
[0018]
FIG. 5 realizes a folding structure in which wiring portions are obliquely overlapped with two valleys and two chevrons provided with diagonally folded folds.
[0019]
That is, the valley-shaped folds 34 and the mountain-shaped folds 35 are arranged in an obliquely parallel direction on the upper side of the figure, and the valley-shaped folds 36 and the mountain-shaped folds 37 are arranged in the obliquely parallel direction on the lower side of the figure.
[0020]
In this folding structure, as in the embodiment of FIG. 3, by combining the mountain fold and the valley fold, the flexibility can be increased by utilizing the difference between the inner and outer peripheries of the flexible printed circuit board. The same applies to the fact that the length of the flexible printed circuit board on the outside and the inside on the inside is changed by adjusting the bending position.
[0021]
FIG. 6 shows a state in which the folded folds 34, 35, 36, and 37 are folded and folded, and the wiring portions 21 and 22 are folded in a bent state almost in an S-shape. The projections respectively project left and right in the figure.
[0022]
With such a folded shape, other components can be avoided on the left and right of the wiring portion 21. Further, since the folding folds 34, 35, 36 and 37 are provided diagonally, the folding reduces the overall length and overall width of the FPC.
[0023]
【The invention's effect】
According to the present invention, as described above, the wiring portion of the flexible printed circuit board is formed as two portions sandwiching a space therebetween, and has a folding fold in a direction intersecting the direction in which the wiring extends, and the folding fold is Since it includes peaks and valleys when viewed from one side of the flexible printed circuit board, it is possible to take advantage of the characteristics of the single-sided FPC, which has good flexibility, and the direction of the fold is appropriate, and the wiring is hardly disconnected. In addition, since the wiring portion composed of two portions has a difference in length that absorbs the difference between the inner and outer circumferences at the time of bending, a more flexible FPC can be provided.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an application target of the present invention.
FIG. 2 is an explanatory view showing a folded shape of the FPC shown in FIG. 1;
FIG. 3 is an explanatory diagram showing the configuration of one embodiment of the present invention.
FIG. 4 is an explanatory view showing a folded state of the embodiment shown in FIG. 3;
FIG. 5 is an explanatory diagram showing a configuration of another embodiment according to the present invention.
FIG. 6 is an explanatory view showing a folded state of the embodiment shown in FIG. 5;
[Explanation of symbols]
11, 12 terminal portions 21, 22 wiring portions 31, 32, 33 folded folds

Claims (2)

A flexible printed circuit board comprising a pair of terminals provided at each end of the flexible substrate and a wiring portion connecting between these terminals, wherein the flexible substrate is configured to be bendable.
The wiring portion is formed as two portions having a space therebetween, and has a bent fold in a direction crossing a direction in which the wiring extends,
The folded fold includes peaks and valleys as viewed from one surface of the flexible printed board, and is configured to be foldable along the folded fold,
A flexible printed circuit board, wherein the wiring portion on the outer peripheral side of the bending is configured to be longer in the bending circumferential direction than the wiring portion on the inner peripheral side of the bending. In an electronic device in which a device case is divided into two parts and these two parts are joined by a hinge,
An electronic device, wherein the flexible printed circuit board according to claim 1 is provided on the hinge.

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