KR20050110747A - Flexible printed circuit film - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit film, wherein a wiring structure formed by being printed on the flexible printed circuit film is divided into a wiring in a long axis direction and a wiring in a short axis direction and disposed on different layers, and flexible printing. At the connecting portion of the circuit film, the wires in the long axis direction and the wires in the short axis direction have an angle of 90 ° to each other. As a result, it is possible to form a flexible circuit printed film suitable for miniaturization, light weight, and high density of electronic devices, and not only various characteristics of adhesion, heat resistance, and electrical insulation according to the advancement of electronic devices, but also wiring of flexible printed circuit films It is possible to form a flexible printed circuit film in which interference between signals transmitted through is minimized.

Description

Flexible Printed Circuit Film {FLEXIBLE PRINTED CIRCUIT FILM}

The present invention relates to a flexible printed circuit film.

Conventionally, flexible printed circuit film (FPC) has been used mainly in a form folded in a narrow space inside the camera to take advantage of the flexibility (flexibility) easily. However, printed circuit boards (PCBs), which are recently used in driving parts of floppy disk drives, hard disk drives, copiers, printers, and the like, are also being used in liquid crystal displays (LCDs), which are in the spotlight as display devices for information display. ) Is used as a means of connecting the display panel and the display panel.

An LCD is opposed to a thin film transistor array panel on which gate lines, data lines, thin film transistors, and pixel electrodes are formed, and a color filter display panel on which color filters and a common electrode are formed, and between the thin film transistor array panel and a color filter display panel. It consists of a liquid crystal layer etc. which were filled. The thin film transistor is a switching element that transfers or blocks an image signal transmitted along a data line to a pixel electrode by a scan signal transmitted along a gate line. The gate line and the data line receive scan signals and image signals from the gate driving chip and the data driving chip, respectively. The gate driving chip and the data driving chip are connected to the thin film transistor array panel in various ways. Among them, a tape carrier package (TCP) method and a chip on glass (COG) method are mainly used.

The tape carrier package (TCP) method is a method of separately attaching a tape having a driving chip to a thin film transistor array panel, and a chip on glass (COG) method is a method of directly attaching a driving chip on an insulating substrate of a thin film transistor array panel.

Among the above methods, the conventional TCP (tape carrier package) method has been mainly used, but at present, the chip on glass (COG) method is mainly used due to the reduction of the area occupied by the chip and the cost reduction.

The signal applied to the driving chip is generated by a control unit on a separate printed circuit board (PCB) and transmitted to the driving chip through a flexible printed circuit film.

Such a flexible printed circuit film is a cover lay formed on a flexible printed wiring film produced by integrating an adhesive into an electrically insulating film or by directly integrating a metal film, and laminated on a base film and an adhesive. lay) It is based on what laminated | stacked the film further.

As miniaturization, light weight, and high density of electronic devices have progressed in recent years, high quality corresponding to them has been further demanded in the characteristics of flexible printed circuit boards.

As the situation progresses, the flexible printed circuit film requires not only various properties of adhesiveness, heat resistance, and electrical insulation, but also no interference between signals transmitted through the wiring of the flexible printed circuit film.

The conventional flexible printed circuit film has a structure in which a plurality of wirings are dense at the input end portion of the flexible printed circuit film so that the wiring starting from the input end of the flexible printed circuit film is connected to the output side. In addition, the wiring in the long axis direction and the wiring in the short axis direction are mixed in the same layer. There are two layers in the flexible printed circuit film. In the past, the wiring in the long axis direction and the wiring in the short axis direction were mixed and arranged in one layer, and as a result, the wiring density of the input end portion of the flexible printed circuit film was mixed. This was even worse.

Since the wiring in the long axis direction and the wiring in the short axis direction are arranged irrespective of the layers, twisting may occur between the wirings, and due to the wiring density at the input end portion of the flexible printed circuit film, Problems will arise. That is, the signal shakes due to the noise of the power signal, and the frequency margin is also less than the margin recorded in the specification (SPEC) of the flexible printed circuit film.

In addition, conventionally, the wiring between the same signal components during the input is connected to the wiring on the output side by interconnecting at the input side. At this time, there is a case where a cross phenomenon with components of other signals occurs while connecting the input wiring.

In addition, in the conventional wiring structure, there is a case in which the wiring on the input side has a wiring structure that is seamlessly connected to the output terminal through the end of the flexible printed circuit film, and this wiring structure has a ground signal between the right and left wires of the seamless wiring. There is a disadvantage that the separation of.

The technical problem to be solved by the present invention is a flexible printed circuit having a wiring structure that minimizes signal interference between wirings because wirings on the flexible printed circuit film are closely located with each other according to the miniaturization, light weight, and high density of electronic devices as described above. To provide a film.

In order to solve this problem, in the present invention, a wiring structure formed by being printed on the flexible printed circuit film 10 is divided into a wiring 17 in a long axis direction and a wiring 15 in a short axis direction, which are different layers. And the wiring 17 in the long axis direction and the wiring 15 in the short axis direction are at an angle of 90 ° to each other at the connection portion of the flexible printed circuit film 10 to minimize interference between the wiring signals. Present a printed circuit film.

In addition, the present invention provides a flexible printed circuit film which is formed at the input end of the flexible printed circuit film so that wiring is not crowded with each other.

Specifically, a connection part including a wire formed in a predetermined pattern and a flexible insulating film surrounding the wire, and connecting an input terminal, an output terminal, and the input terminal and the output terminal according to a transmission direction of a signal input to the wiring. In the flexible printed circuit film including the respective portions defined as, when the longitudinal direction and the width direction of the connecting portion, respectively, the long axis direction and the short axis direction, the input end is formed in the short axis direction and formed by different layers from each other The first short wiring and the second short wiring are formed, and in the output terminal, the third short wiring is formed in the short direction and is formed in the same layer as the first short wiring. It is formed in the long axis direction and is formed by different layers from the first single-axis wiring A second long-axis wiring, which is an extension line of the first long-axis wiring and the second short-circuit wiring, is formed, and a portion of the first short-axis wiring and the third short-circuit wiring extend to connect with at least one of the first long-axis wiring. The invention relates to a flexible printed circuit board.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

A flexible printed circuit film according to an embodiment of the present invention will now be described in detail with reference to the drawings.

1 is a view showing the overall structure and wiring of a flexible printed circuit film according to an embodiment of the present invention, Figure 2 is a view showing in detail the central portion of the flexible printed circuit film according to an embodiment of the present invention; 3 is a view showing only one layer of the wiring structure of FIG. 2 showing a central portion of the flexible printed circuit film according to the embodiment of the present invention, and FIG. 4 is a flexible according to the embodiment of the present invention. FIG. 5 is a view illustrating only one layer of the wiring structure of FIG. 2 showing the central portion of the flexible printed circuit film, and FIG. 5 illustrates the wiring structure of an end portion of the flexible printed circuit film according to the embodiment of the present invention. Figure is shown.

Referring to Figure 1, the wiring of the flexible printed circuit film is formed in the short axis direction from the input end is connected to the wiring in the long axis direction. Thereafter, it has a wiring structure which is connected from the wiring in the long axis direction to the short direction wiring in the output terminal again.

2 to 5 will be described in detail below.

Although the flexible printed circuit film 10 is not shown in the figure, the layer on which the wiring is formed is formed of a double layer (hereinafter referred to as a double layer structure). In the flexible printed circuit film, the long-axis wiring 17 and the short-axis wiring 15 are disposed in each layer in the double layer structure, and are electrically connected through the through hole 16 to be connected to the wiring of the other layer.

In order to examine in detail, the flexible printed circuit film 10 is divided into an input end 20, an output end 30, and a connection part connecting the input end 20 and the output end 30.

First, the unidirectional wiring 15 is formed in the input terminal 20. The unidirectional wiring 15 of the input terminal 20 may be divided into two types. One is located at the center of the input terminal 20, and has a wiring structure (first single direction wiring) arranged in the short axis direction at the connection part, and the other is located at both sides of the input terminal 20, and the diagonal direction and the long axis direction at the connection part. Has a wiring structure (second unidirectional wiring) arranged.

 The first short-directional wiring is electrically connected to the long-axis wiring (first long-axis wiring) and the through hole 16 at the connection portion. In addition, the first short-directional wiring is formed in a layer different from the first long-axis wiring.

As shown in FIG. 3 and FIG. 4, the first short-directional wiring is formed to cross the connecting portion through the short-axis wiring at the center of the input terminal 20. However, it is not formed in one layer, but is formed to cross the connecting portion while being connected to the unidirectional wiring of another layer through the through hole 16 in order to prevent twisting with the long-axis wiring of the connecting portion. do. The crosswise first short-directional wiring is connected to the first long-axis wiring of the connecting portion through the through hole 16. As shown in FIGS. 2 and 4, the first long-axis direction wiring connected to the first short-directional direction wiring is formed at a position closer to the output terminal 30 than the input terminal 20.

However, the second short-directional wiring is directly connected to the long-axis wiring (the second long-axis wiring) and is formed on the same layer as the second long-axis wiring.

As shown in FIG. 4, the second short-directional wiring is connected to the second long-axis wiring in one layer. The second short-axis wiring and the second long-axis wiring are connected via diagonal lines.

Although the wiring of the layer shown in FIG. 3 includes only unidirectional wiring, the layer shown in FIG. 4 is connected to the unidirectional wiring (strictly the second unidirectional wiring) at the input terminal 20 and connected thereto. It includes oblique wiring, and all are formed of long-axis wiring (strictly second long-axis wiring). The layer shown in FIG. 4 includes the second short-axis wiring and the diagonal wiring in addition to the second long-axis wiring, for the following reasons.

First, since the input terminal can have only short-directional wiring, in order to connect with the long-axis wiring (second long-axis wiring) in the connecting part, the short-axis wiring and the long-axis wiring with different layers are formed and then through the through hole. Should be connected. However, since this multilayer structure only complicates the manufacturing process, it was formed as a structure including the second short axis direction wiring and the second long axis direction wiring in one layer as in this embodiment.

In addition, since the wiring is prevented from being concentrated in the portion where the input terminal 20 and the connecting portion are connected to each other through the wiring in the diagonal direction, the structure is formed to include the wiring in the diagonal direction as in the present embodiment.

It does not matter which of the layers shown in Figs. 3 and 4 should be located on the upper layer.

FIG. 5 illustrates an end portion of the flexible printed circuit film 10 shown in FIG. 1.

Long-axis wiring (first long-axis wiring and second long-axis wiring) connected from the input terminal 20 is connected to the wiring of the output terminal (30). The wires of the output terminal 30 are all formed by short-axis wiring (third short-axis wiring), and the wiring of the output terminal 30 includes the long-axis wiring (first long-axis wiring and the second long-axis wiring) and the through hole of the connecting portion. Electrically connected via 16. In addition, the long-axis wiring (the first long-axis wiring and the second long-axis wiring) and the short-axis wiring (the third short-axis wiring) are formed in different layers.

By forming the wiring structure of the flexible printed circuit film 10 as described above, the wiring is not dense at the input terminal 20 portion of the flexible printed circuit film 10. In addition, by arranging the long-axis wiring and the short-directional wiring in different layers, it is possible to minimize the interference between the signals of the wiring, to prevent the separation of the ground signal and the intersection between the signal components. In addition, it operates with low voltage and low current, and is suitable for use in home appliances that are miniaturized.

As an example in which the flexible printed circuit film 10 thus formed is used in home appliances, FIG. 6 illustrates a state of use in a liquid crystal display using a thin film transistor.

The liquid crystal display shown in FIG. 6 mounts the driving integrated circuits 410 and 510 on the lower display substrate 100 using the COG method, and the driving integrated circuits 410 and 510 are flexible printed circuit films 10. It is formed in connection with the output terminal 30 of. In addition, the input terminal 20 of the flexible printed circuit film 10 is connected to the PCB 650. The PCB 650 includes a controller (not shown) for controlling the liquid crystal display, and a control signal of the liquid crystal generated from the controller is input through the PCB 650 to the input terminal 20 of the flexible printed circuit film 10. The input signal is transmitted to the output terminal 30 along the wiring of the flexible printed circuit film 10.

The control signal from the output terminal 30 is input to the data driver integrated circuit 510 and the gate driver integrated circuit 410 to control the liquid crystal display.

The cross section of the flexible printed circuit film 10 as described above is as shown in FIG. That is, the wiring 17 in the major axis direction and the wiring 15 in the minor axis direction are formed and fixed by using the adhesive 12 for wiring on both sides of the flexible film 11, and the adhesive for insulating protective film 13 is formed thereon. Using the insulating protective film 14 is formed.

In detail, the flexible film 11 uses a flexible film made of a polymer, and generally uses a polyimide having excellent flexibility and heat resistance. The thickness of the flexible film 11 is generally about 12.5 μm to 75 μm, but the flexible film 11 having a thickness of more than 50 μm has a thickness of 12.5 μm to 50 μm because of poor flexibility. Film 11 is preferred.

The wiring adhesive 12 may be epoxy resin, phenol resin, or the like, and the thickness of the wiring adhesive 12 may be about 10 μm to 20 μm. It is preferable to form same as thickness.

The wirings 15 and 17 are mainly formed of copper, which is formed by bonding the flexible film 11 to the flexible film 11 using the wiring adhesive 12 and then wet etching the wiring. The wires are formed on both sides of the flexible film 11, and the wires 15 and 17 formed on both sides of the flexible film 11 are electrically connected through the through holes 16.

The wirings 15 and 17 on both sides are respectively covered with an insulating protective film 14 made of a polymer. Although not shown, the wirings 15 and 17 are formed to be exposed to and contact with the outside at the input terminal 20 and the output terminal 20.

In general, the insulating protective film 14 is preferably polyimide excellent in flexibility and heat resistance, and is adhered to the wirings 15 and 17 by the adhesive 13 for insulating protective film. As the adhesive 13 for insulating protective film, an epoxy adhesive, an acrylic adhesive, a polyester adhesive, etc. are used.

In general, the thickness of the adhesive protective layer 13 for insulating protective film is formed to a thickness of about 15㎛ ~ 30㎛, the thickness of the insulating protective film is not defined, but is generally formed in half of the thickness of the flexible film (11). .

In the present embodiment, as shown in FIG. 7, the wirings 15 and 17 are formed on the film by using an adhesive, thereby manufacturing the flexible printed circuit film 10. It can manufacture by a method.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, in forming the flexible printed circuit film, the wiring in the long axis direction and the wiring in the short axis direction are formed in different layers, and the wiring in the long axis direction and the wiring in the short axis direction are mutually 90 degrees. By forming the angles and forming the wiring so that the wiring is not crowded at the input end portion of the flexible printed circuit film, a flexible circuit printed film suitable for miniaturization, weight reduction, and high density of electronic equipment can be manufactured. In addition to satisfying various properties of adhesiveness, heat resistance, and electrical insulation according to advancement, a flexible printed circuit film capable of minimizing interference between signals transmitted through the wiring of the flexible printed circuit film may be formed.

1 is a view showing the overall structure and wiring of a flexible printed circuit film according to an embodiment of the present invention.

2 is a view illustrating in detail the central portion of the flexible printed circuit film according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating only one layer of the wiring structure of FIG. 2 showing the central portion of the flexible printed circuit film according to the embodiment of the present invention.

FIG. 4 is a diagram illustrating only another layer of the wiring structure of FIG. 2 showing a central portion of the flexible printed circuit film according to the embodiment of the present invention.

5 is a diagram illustrating a wiring structure of an end portion of a flexible printed circuit film according to an exemplary embodiment of the present invention.

FIG. 6 is a state diagram in which a flexible printed circuit film according to an embodiment of the present invention is used, and FIG. 6 is a state diagram used in a thin film transistor array panel.

FIG. 7 is a cross-sectional view taken along line XX 'of FIG. 9.

<Description of the symbols for the main parts of the drawings>

10: flexible printed circuit film 11: flexible film

12: Adhesive for wiring 13: Adhesive for insulating protective film

14: insulating protective film

15: single-axis wiring 17: long-axis wiring

16: through hole

20: input stage 30: output stage

100: lower display substrate 200: upper display substrate

410: gate driving integrated circuit 510: data driving integrated circuit

650: printed circuit board

Claims (11)

A wire formed in a predetermined pattern and a flexible insulating film surrounding the wire, and defined by an input end, an output end, and a connection part connecting between the input end and the output end according to a transmission direction of a signal input to the wire. In a flexible printed circuit film containing parts, When the longitudinal direction and the width direction of the connecting portion are called a major axis direction and a minor axis direction, respectively, The input terminal is formed with a first short wiring and a second short wiring formed in the short axis direction and formed with different layers from each other, The output terminal is formed with a third single-axis wiring formed in the short axis direction and formed of the same layer as the first single-axis wiring, The connection part is formed with a first long-axis wiring and a second long-axis wiring, which is an extension line of the second short-circuit wiring, which is formed in the long-axis direction and is formed by different layers from the first short-circuit wiring. And a portion of the third short-circuit wiring extending and connected to at least one of the first long-axis wiring. In claim 1, The first short wiring is formed in a central portion of the input terminal, and the second short wiring is formed on both sides of the first short wiring at the input terminal. In the flexible printed circuit film where the wiring is formed, The wiring is formed in double layers, The flexible printed circuit film which forms the wiring formed along the longitudinal direction of a flexible printed circuit film, and the wiring formed along the short axis of a flexible printed circuit film in different layers, respectively. Flexible film, First and second wiring layers formed on both sides of the flexible film, In the flexible printed circuit film comprising a first and a second insulating protective film to cover and insulate the first wiring layer and the second wiring layer, respectively, The first wiring layer includes only the wiring formed in the long axis direction of the flexible film, and the second wiring layer includes only the wiring formed in the short axis direction of the flexible film. In claim 4, A flexible printed circuit film, wherein the wirings forming the first wiring layer and the second wiring layer form an angle of 90 ° to each other. In claim 4, And the flexible film and the first and second wiring layers are attached to the flexible film using an adhesive for wiring. In claim 4, And the first and second insulating protective films are attached to the first and second wiring layers using an adhesive for insulating protective film. In claim 4, And the flexible film and the first and second insulating protective films are formed of polyimide. In the flexible printed circuit film where the wiring is formed, The wiring is formed in double layers, One layer of the double layer includes all the wires in the long axis direction, and includes wires connected to the wires in the long axis direction starting from an input terminal of the flexible printed circuit film. The other one of the double layer is a wiring except for the wiring included in the one layer, the flexible printed circuit film formed by including only unidirectional wiring. In claim 9, The flexible printed circuit film starting from the input terminal of the flexible printed circuit film and connected to the wiring in the long axis direction includes a short axis direction wire. The method of claim 9 or 10, The flexible printed circuit film starting from the input terminal of the flexible printed circuit film and connected to the wiring in the long axis direction includes diagonal wires.