KR102569655B1 - Flexible Cable - Google Patents

Abstract

The present embodiments relate to a flexible cable, which is divided into a line area and a terminal area, signal lines and ground lines are disposed, each ground line includes first to third pattern portions, and the first to third patterns The parts have different widths and lengths. According to these embodiments, ground lines are arranged on both sides of the area where the signal lines are arranged, thereby preventing noise defects caused by an external electric field (signal).

Description

Flexible Cable {Flexible Cable}

The present embodiment relates to a flexible cable, and more specifically, to a flexible cable that is resistant to noise and has excellent impedance characteristics.

In general, display devices such as Organic Emitting Display Diodes (OLEDs) and Liquid Crystal Displays (LCDs) have a display panel disposed inside a case, and a main printed circuit board outside the case ( Printed Circuit Board: PCB) and sub PCB are arranged.

The display panel is electrically connected to the main PCB or sub PCBs, and may be connected by, for example, a cable such as LVDS (Low Voltage Differential Signaling).

However, since the manufacturing cost of the LVDS cable connecting the display panel and the main PCB or sub-PCB is high, a flexible cable such as a flexible flat cable (FFC) or a flexible printed circuit (FPC), which is cheaper, has recently been widely used.

The flexible cable as described above includes a plurality of signal lines, each of which includes a terminal on one side (for example, a terminal connected to a display device) and a terminal on the other side (eg, a terminal connected to a PCB). Terminals of the flexible cable have a structure in which terminals of a device to be connected are connected in a 1:1 manner.

Accordingly, the flexible cable includes terminals for connection and a plurality of corresponding signal lines, which are spaced apart from each other within an insulating film. As described above, since a plurality of signal lines for signal transmission are disposed on an insulating film, the conventional flexible cable is vulnerable to noise caused by an external electric field.

In particular, signal lines disposed on both edges of the flexible cable do not have other signal lines in an adjacent area, causing problems such as signal distortion due to noise.

In addition, when a flexible cable connecting the display panel and the PCB is vulnerable to noise, as a result, signals supplied to the display device are distorted, resulting in deterioration in image quality.

An object of the present embodiment is to provide a flexible cable in which noise defects due to an external electric field (signal) are prevented by disposing ground lines on both sides of an area where signal lines are disposed.

In addition, another object of the present embodiment is to provide a flexible cable having improved impedance characteristics by forming ground lines disposed on both sides of the signal lines into pattern portions having different widths and lengths.

In the present embodiments, in a flexible cable divided into a line area and a terminal area and having signal lines and ground lines disposed thereon, each ground line includes first to third pattern portions, and the first to third pattern portions are Flexible cables having different widths and lengths may be provided.

The present embodiments may provide a flexible cable in which signal lines are spaced apart at predetermined intervals and ground lines are respectively disposed on both sides of the signal lines.

In the present embodiments, the signal lines may provide a flexible cable connected to any one of gate lines, data lines, power lines, and common lines disposed on the display panel.

In the present embodiments, the first to third pattern parts of the ground line may be integrally formed with each other to provide a flexible cable.

In the present embodiments, the first and third pattern portions of the ground line may provide a flexible cable parallel to the signal lines.

In the present embodiments, the second pattern part of the ground line is disposed between the first pattern part and the third pattern part, and a streamlined flexible cable having a predetermined curvature may be provided.

In the present embodiments, each ground line may provide a flexible cable in which total impedance of the flexible cable is adjusted according to the width and length of the first to third pattern portions.

The present embodiments may provide a flexible cable in which signal lines and ground lines are electrically insulated from each other by a film layer composed of a plurality of laminated protective layers.

The present embodiments may provide a flexible cable in which the film layer includes first and second protective layers, and signal lines and ground lines are disposed between the first and second protective layers.

In the present embodiments, the film layer includes first to third protective layers stacked, signal lines are disposed between the first and second protective layers, and ground lines are disposed between the second protective layer and the third protective layer. It is possible to provide a flexible cable disposed on.

The present embodiments can provide a flexible cable having an effect of preventing noise defects caused by an external electric field (signal) by disposing ground lines on both sides of an area where signal lines are disposed.

In the present embodiments, the ground line disposed on both sides of the signal lines is formed with pattern parts having different widths and lengths, thereby providing a flexible cable having an effect of improving impedance characteristics.

In the present embodiments, in a flexible cable divided into a line area and a terminal area and having signal lines and ground lines arranged therein, the signal lines are spaced apart at predetermined intervals, and the ground lines are arranged on both sides of the signal lines, respectively. Each ground line may include first and second pattern portions, and the first and second pattern portions may provide a flexible cable having different widths and lengths.

The flexible cable according to the present embodiment has an effect of preventing noise defects caused by an external electric field (signal) by disposing ground lines on both sides of an area where signal lines are disposed.

In addition, the flexible cable according to the present embodiment has an effect of improving impedance characteristics by forming the ground lines disposed on both sides of the signal lines into pattern portions having different widths and lengths.

1 is a plan view illustrating a flat flexible cable board.
FIG. 2 is a plan view illustrating a flexible cable separated from the flat flexible cable plate of FIG. 1;
FIG. 3 is a diagram illustrating the occurrence of noise defects in a flexible cable due to an external electric field.
4 is a view showing a flat flexible cable plate according to the first embodiment.
5 is a plan view illustrating a flexible cable separated from the flat flexible cable plate of FIG. 4;
FIG. 6 is a view showing how an external electric field is shielded in the flexible cable according to the first embodiment.
7A and 7B are diagrams for explaining impedance characteristics according to the width and length of each pattern part of the ground line of FIG. 4 .
8 and 9 are cross-sectional views taken along line II' of FIG. 5 .
10 is a view showing a flat flexible cable plate according to a second embodiment.
11 is a plan view illustrating a flexible cable separated from the flat flexible cable plate of FIG. 10;
12A and 12B are diagrams for explaining impedance characteristics according to the width and length of each pattern part of the ground line of FIG. 11 .

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, when a temporal precedence relationship is described as 'after', 'continue to', 'after ~', 'before', etc., 'immediately' or 'directly' As long as ' is not used, non-continuous cases may also be included.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. may be

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. And in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numbers indicate like elements throughout the specification.

1 is a plan view showing a flat flexible cable plate, and FIG. 2 is a plan view showing a flexible cable separated from the flat flexible cable plate of FIG.

Referring to FIGS. 1 and 2 , the flexible cable 200 may be formed by cutting (separating) a predetermined unit from the flat flexible cable plate 100 . The flat flexible cable board 100 includes a mother film layer (OFL) on which a plurality of protective layers and adhesive layers are stacked, and signal lines (SL) and ground lines (GL) disposed in the mother film layer (OFL).

In addition, the flat flexible cable board 100 is partitioned into the first and second terminal areas TA1 and TA2 and the line area LA between the first and second terminal areas TA1 and TA2, and the signal lines ( SL) and the ground line GL are disposed on the line area LA and the first and second terminal areas TA1 and TA2.

As shown in FIG. 1, if the separation process (cutting process) is performed along the cutting line CL for the flat flexible cable plate 100, the flexible cable 200 shown in FIG. 2 is completed. . Thus, the plurality of flexible cables 200 can be separated from the flat flexible cable plate 100 .

Accordingly, the flexible cable 200 has a structure in which a plurality of signal lines SL and ground lines GL are electrically spaced apart from each other in a film layer FL composed of a plurality of protective layers and adhesive layers.

The flexible cable 200 shown in FIG. 2 shows one separated into a plurality based on the cutting line CL of the flat flexible cable plate 100. Accordingly, the flexible cable 200 is divided into a line area LA and a terminal area (first and second terminal areas TA1 and TA2), as in the flat flexible cable board 100. Parts of the signal lines and ground lines disposed at positions corresponding to the first and second terminal regions TA1 and TA2 may be referred to as first and second terminal portions TP1 and TP2.

The first and second terminal units TP1 and TP2 may be connected to terminals of a display panel (or electronic device) and PCB terminals, respectively.

However, in the flexible cable 200 shown in FIG. 2 , the ground line GL is disposed only on one side of the area where the signal lines SL are disposed, so that signal interference is prevented in the area where the ground line GL is not disposed. There is a problem that noise defect (Noise) occurs due to

FIG. 3 is a diagram illustrating the occurrence of noise defects in a flexible cable due to an external electric field.

Referring to FIG. 3 , the flexible cable 200 is located on one side of the signal lines SL, that is, in the drawing, since the ground line GL is disposed only on the left side of the signal lines SL, the ground line GL is disposed in the left area. An applied external electric field is shielded by the ground line GL.

However, since the ground line GL adjacent to the edge signal line SL does not exist in the right area of the signal lines SL, there is a noise defect in which signals supplied to the signal lines SL are distorted by an external electric field. occurs

Also, since the flexible cable 200 of FIG. 2 only considers a 1:1 electrical connection between terminals, the signal lines SL and the ground line GL are formed to have the same width and length. That is, the flexible cable 200 manufactured through a cutting process may be manufactured in various sizes (for example, different numbers of signal lines) according to areas of use.

However, since the impedance characteristics of the flexible cable required in the use area (signals transmitted in the use area, or fastening device) are not considered at all, there is a disadvantage in that it is vulnerable to distortion (voltage drop, etc.) of the transmission signal.

In the present embodiments, noise defects caused by an external electric field (signal) are prevented by disposing ground lines on both sides of an area where signal lines are disposed.

In addition, in the present embodiments, the ground line disposed on both sides of the signal lines is adjusted to have various resistance values, so that the flexible cable has the most suitable impedance value for the area where the flexible cable is used, so that defects such as signal distortion are prevented. there is.

4 is a view showing a flat flexible cable plate according to the first embodiment, and FIG. 5 is a plan view showing a flexible cable separated from the flat flexible cable plate of FIG. 4 .

Referring to FIGS. 4 and 5 , the flexible cable 400 of the first embodiment is formed by cutting along the cutting line CL of the flat flexible cable plate 300 shown in FIG. 4 .

The flat flexible cable board 300 includes first and second terminal areas TA1 and TA2 connected to terminals of a display device (display panel or electronic device) and a PCB, and first and second terminal areas TA1 and TA2 ), including the line area LA between.

A plurality of signal lines SL and ground lines GL are disposed on the flat flexible cable board 300, and the ground line GL is composed of first to third pattern parts 320a, 320b, and 320c. and they are connected in a pair form before being separated by the flexible cable 400.

That is, the ground lines GL are arranged in pairs between predetermined signal line groups, and the two ground lines GL are commonly connected to the first pattern portions 320a.

Accordingly, a pair of ground lines GL are disposed between a plurality of signal line groups in the flat flexible cable board 300, and the pair of ground lines GL share the first pattern portion 320a while , the second pattern parts 320b are branched from each other, and the third pattern parts 320b and 32c are branched from each of the second pattern parts 320b.

When the flexible cable 400 is separated from the flat flexible cable plate 300, as shown in FIG. 5, one flexible cable 400 connects the terminal areas (first and second terminal areas, TA1 and TA2) and the line Ground lines GL are disposed on both sides of each of the signal lines SL, which are partitioned into an area LA and spaced apart at predetermined intervals.

The signal lines SL may be lines connected to any one of terminals of gate lines, data lines, power lines, and common lines disposed on the display panel.

The ground line GL includes first to third pattern portions 320a, 320b, and 320c, and the first to third pattern portions 320a, 320b, and 320c have different widths (W) and lengths (L). It can be patterned to have.

The first pattern part 320a of the ground line GL is disposed to overlap the first terminal area TA1 and part of the line area LA of the flexible cable 400, and the second pattern part 320b has a first The pattern portion 320a extends and is disposed in the line area LA, and the third pattern portion 320c extends from the second pattern portion 320b and is disposed in the line area LA.

Also, the first to third pattern portions 320a, 320b, and 320c are integrally formed with each other to form one ground line GL.

In addition, the first pattern part 320a and the third pattern part 320c of the ground line GL are disposed parallel to the signal lines SL, and the second pattern part 320b has the first pattern part 320a ) and the third pattern portion 320c to form a streamlined shape having a predetermined curvature.

The streamlined structure of the second pattern part 320b is due to the third pattern part 320c of the ground line GL after the ground lines GL connected to each other as a pair in the flat flexible cable board are cut by a cutting process. This is to ensure that is disposed parallel to the adjacent signal lines SL.

As described above, the flexible cable 400 according to the first embodiment has the ground line GL disposed on both sides of the signal line SL group as a center, so that an electric field applied from the outside can be shielded, resulting in poor noise. can prevent

FIG. 6 is a view showing how an external electric field is shielded in the flexible cable according to the first embodiment.

Referring to FIG. 6 , in the flexible cable 400 according to the first embodiment, ground lines GL are disposed on both sides (left and right edges) of a plurality of signal lines SL, respectively.

Therefore, when an external electric field is applied from both edges of the flexible cable 400, all of them are shielded by the ground line GL, so distortion or noise defect of signals transmitted through the signal lines does not occur.

In addition, when manufacturing the flat flexible cable plate for forming the flexible cable 400 as in the first embodiment, a pair of ground lines can be connected in common with the first pattern portion 320a, thereby reducing the number of terminal portions of the ground line. There are possible effects.

7A and 7B are diagrams for explaining impedance characteristics according to the width and length of each pattern part of the ground line of FIG. 4 .

Referring to FIGS. 7A and 7B together with FIG. 5 , the ground line GL disposed in the flexible cable 400 according to the first embodiment is composed of first to third pattern portions 320a, 320b, and 320c. , Their widths (W1, W2, W3) and lengths (L1, L2, L3) can be formed with various design values.

Since the pair of ground lines disposed on the flat flexible cable plate have a cutting line CL centered on the first pattern portion 320b (see FIG. 4), the width W1 of the first pattern portion 320a is It is reduced by half compared to when placed on a flat flexible cable plate.

Accordingly, as shown in FIG. 7A, the widths W1, W2, and W3 and the lengths L1, L2, and L3 of the first to third pattern portions 320a, 320b, and 320c of the ground line GL may vary. value, and because of this, the value of the resistance R of the ground line GL can also be set to various values.

In general, resistance (R) decreases in inverse proportion to the width (W) of the wiring pattern and changes in proportion to the length (L). Resistance can change.

More specifically, when looking at the structure of each pattern part 320a, 320b, 320c of the ground line GL shown in FIG. 7A and each pattern part of the ground line GL shown in 7B, since they are formed in different shapes, FIG. The resistance value R1 of the ground line of FIG. 7a and the resistance value R2 of the ground line of FIG. 7b are different from each other.

In this way, when the resistance of the ground line disposed on the flexible cable is changed, the entire impedance (including the signal lines) of the flexible cable including the signal line can be adjusted.

Accordingly, the widths W1, W2, and W3 and the lengths L1, L2, and L3 of the first to third pattern portions 320a, 320b, and 320c of the ground line are considered in consideration of signal characteristics or use areas transmitted by the flexible cable. Therefore, the impedance characteristics of the flexible cable can be improved.

As described above, in the first embodiment, the flexible cable can be designed to have the most appropriate impedance value according to the signal to be transmitted or the region of use, so that the deterioration of the image quality of the display device due to signal distortion can be prevented.

8 and 9 are cross-sectional views taken along line II' of FIG. 5 .

Referring to FIGS. 5 and 8 , the flexible cable 400 includes a film layer FL, and a plurality of signal lines SL and ground lines GL disposed in the film layer FL.

More specifically, the film layer FL has a structure in which at least one protective layer and an adhesive layer are stacked, and the signal lines SL and gate lines GL are disposed between the protective layers.

Referring to FIG. 8 , a plurality of signal lines SL and a ground line GL are disposed on the first protective layer 600a of the film layer FL, and both sides of the signal lines SL have ground lines ( GL) of the third pattern portion 320c is disposed.

A second protective layer 600b is disposed on the signal lines SL and the ground line GL (here, the third pattern portion 320c), and a cover layer 610 is disposed on the second protective layer 600b. do.

Accordingly, the plurality of signal lines SL disposed on the flexible cable 400 generate an external electric field (signal) by the ground lines GL disposed on both sides, that is, the third pattern portion 320c of the ground line GL. The back is shielded to prevent noise defects.

5 and 9, in the flexible cable 400, a plurality of signal lines SL are disposed on a first protective layer 600a, and a second protective layer ( 600b) is placed.

The ground line GL is disposed on the second passivation layer 600b corresponding to both sides of the signal lines SL. In FIG. 9 , it can be seen that the third pattern portion 320c of the ground line GL is disposed.

A third protective layer 600c is disposed on the second protective layer 600b and the third pattern portion 320c, and a cover layer 610 is disposed on the third protective layer 600c.

That is, the ground line GL 320c and the signal lines SL are spaced apart from each other with the second passivation layer 600b interposed therebetween.

Therefore, the plurality of signal lines SL disposed on the flexible cable 400 are shielded from an external electric field by the ground lines GL disposed on both sides, that is, the third pattern portion 320c of the ground line GL. (Shield) to prevent noise defects.

In addition, in FIG. 9, the signal lines SL and the ground line GL (third pattern portion 320c) are separated by the second passivation layer 600b, so that the signal lines SL and the ground line GL ) can prevent short-circuit defects, etc.

FIG. 10 is a view showing a flat flexible cable plate according to the second embodiment, and FIG. 11 is a plan view showing a flexible cable separated from the flat flexible cable plate of FIG. 10 .

Referring to FIGS. 10 and 11 , the flexible cable 900 of the second embodiment is formed by cutting along the cutting line CL of the flat flexible cable plate 800 shown in FIG. 10 .

The flat flexible cable board 800 includes first and second terminal areas TA1 and TA2 connected to terminals of a display device (display panel or electronic device) and a PCB, and first and second terminal areas TA1 and TA2 ), including the line area LA between.

In the flat flexible cable board 800, a pair of ground lines GL are separately disposed between the groups of the plurality of signal lines SL, and the ground lines GL are separated from the first pattern part 820a. It is composed of two pattern parts 820b.

When the flexible cable 900 is separated from the flat flexible cable plate 800, as shown in FIG. 11, one flexible cable 900 has a plurality of signal lines DL and ground lines on both sides thereof ( GL) is placed.

The ground line GL includes first and second pattern portions 820a and 820b, which are integrally formed with each other. Also, the width W4 and length L4 of the first pattern portion 820a and the width W5 and length L5 of the second pattern portion 820b may be patterned differently.

The first pattern portion 820a of the ground line GL is disposed to overlap the first terminal area TA1 and part of the line area LA of the flexible cable 900, and the second pattern portion 820b has a first It extends from the pattern portion 820a and is disposed in the line area LA parallel to the signal lines DL.

As described above, in the flexible cable 900 according to the second embodiment, since the ground lines GL are disposed on both sides of the signal lines DL as a center, noise defects can be prevented by an electric field applied from the outside. .

12A and 12B are diagrams for explaining impedance characteristics according to the width and length of each pattern part of the ground line of FIG. 11 .

Referring to FIGS. 12A and 12B together with FIG. 11 , the ground line GL disposed in the flexible cable 900 according to the second embodiment is composed of first and second pattern portions 820a and 820b, and The width W4 and length L4 of the first pattern portion 820a and the width W5 and length L5 of the second pattern portion 820a may be formed to be different from each other (see FIG. 12A ).

Also, as shown in FIG. 12B , a plurality of structures of the first pattern portion 820a and the second pattern portion 820b may be formed in one ground line GL.

Therefore, as shown in FIGS. 12A and 12B , the resistance R value of the ground line GL is variously changed according to the structure of the first and second pattern portions 820a and 820b of the ground line GL. It can be set (R3, R4).

As such, in the second embodiment, there is an effect of adjusting the entire impedance of the flexible cable (including signal lines) according to the resistance of the ground line disposed on the flexible cable.

Accordingly, in the second embodiment, it is possible to design a flexible cable having the most appropriate impedance value according to the signal to be transmitted or the area used, and thus, the deterioration of the image quality of the display device due to signal distortion can be prevented.

The above description and accompanying drawings are merely illustrative of the technical idea of the present invention, and those skilled in the art can combine the configuration within the scope not departing from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: flat flexible cable plate
200: flexible cable
600a: first protective layer
600b: second protective layer
600c: third protective layer
610: cover layer
SL: signal line
GL: ground line

Claims (11)

In a flexible cable partitioned into a line area and a terminal area and having signal lines and ground lines disposed thereon,
It is formed by cutting a flat flexible cable plate on which the signal lines and the ground lines are alternately arranged,
Each of the ground lines provided in the cut flexible cable includes first to third pattern portions;
The first to third pattern parts have different widths and lengths,
A signal line group having at least two or more signal lines is spaced apart from each other on the flat flexible cable plate, and a pair of ground lines are disposed between the signal line groups, and the pair of ground lines are the first The flexible cable is formed in a structure in which one pattern part is shared, the second pattern parts are branched from the first pattern part, and the third pattern part is extended and branched from each of the second pattern parts. According to claim 1,
The signal lines are spaced apart at predetermined intervals, and the ground lines are respectively disposed on both sides of the signal lines. According to claim 1,
The signal lines are flexible cables connected to any one of gate lines, data lines, power lines, and common lines disposed on a display panel. According to claim 1,
The first to third pattern portions are integrally formed with each other. According to claim 1,
The first and third pattern portions are parallel to the signal lines. According to claim 1,
The second pattern part is disposed between the first pattern part and the third pattern part, and has a streamlined shape having a predetermined curvature. According to claim 1,
A flexible cable wherein the total impedance of the flexible cable of each ground line is adjusted according to the width and length of the first to third pattern parts. According to claim 1,
The flexible cable of claim 1 , wherein the signal lines and the ground lines are electrically insulated from each other by a film layer composed of a plurality of laminated protective layers. According to claim 8,
The flexible cable of claim 1 , wherein the film layer includes first and second protective layers stacked thereon, and the signal lines and the ground lines are disposed between the first and second protective layers. According to claim 8,
The film layer includes stacked first to third protective layers, the signal lines are disposed between the first and second protective layers, and the ground lines are disposed between the second protective layer and the third protective layer. A flexible cable placed between them. In a flexible cable partitioned into a line area and a terminal area and having signal lines and ground lines disposed thereon,
formed by cutting a flat flexible cable plate on which the signal lines and the ground lines are alternately disposed;
The signal lines provided in the cut flexible cable are spaced apart at predetermined intervals, and the ground lines are disposed on both sides of the signal lines, respectively.
Each of the ground lines includes first and second pattern parts,
The first and second pattern parts have different widths and lengths,
A signal line group having at least two or more signal lines is spaced apart from each other on the flat flexible cable plate, and a pair of ground lines are disposed between the signal line groups, and the pair of ground lines are the first A flexible cable formed in a structure in which the second pattern parts are branched from the first pattern part while sharing one pattern part.

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