KR20070116371A - Flexible printed circuit and method for fabricating the same, display having the same - Google Patents

Abstract

A FPC(Flexible Printed Circuit), a method for fabricating the same, and a display having the same are provided to enhance the use efficiency of the space in a system, and to prevent the deterioration of an output and shortening of a life due to the deterioration of an illuminating diode. An FPC includes first and second terminal units(130,140), and a wiring unit(120). The first and second terminal units have a plurality of connection terminals and the wiring unit includes a plurality of metal wires corresponding to the plurality of connection terminals. The width of the area in which the wiring unit is formed is narrower than that of the area in which the first and second terminal units are formed. The wiring unit is formed between an insulating and flexible base film and a cover film. A connector is installed on at least one of the first and second terminal units.

Description

FLEXIBLE PRINTED CIRCUIT AND METHOD FOR FABRICATING THE SAME, DISPLAY HAVING THE SAME

1 is a plan view showing an FPC according to a first embodiment of the present invention.

2 is a cross-sectional view taken along the line AA ′ of FIG. 1.

3 is a plan view showing a modification of the FPC according to the first embodiment of the present invention.

4 is a plan view showing an FPC according to a second embodiment of the present invention.

5 is a cross-sectional view taken along the line BB ′ of FIG. 4.

6 is an exploded perspective view of a liquid crystal display device with an FPC according to the present invention.

FIG. 7 is a perspective view illustrating the liquid crystal display shown in FIG. 6 in combination. FIG.

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

110: base film 120: wiring portion

130, 140: terminal 145: connector

150: cover film 160: insulating film

610: upper chassis 620: liquid crystal display panel

630: data PCB 640: gate PCB

650: upper frame 660: backlight assembly

670: lower frame 680: lower chassis

690: heat sink 700: control PCB

710: flexible printed circuit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit (FPC), a method of manufacturing the same, and a display device having the same. In particular, a flexible printed circuit having a narrow central portion as compared to both ends thereof in order to improve air flow in a system; A manufacturing method thereof and a display device having the same.

As one of the display devices, a liquid crystal display is a display device that realizes an image by controlling the amount of light incident from a light source by using optical anisotropy of liquid crystal molecules and polarization characteristics of a polarizing plate. It is possible to realize the reduction in power consumption and the power consumption is small, and its application range is rapidly expanding in recent years.

In general, a liquid crystal display device includes a liquid crystal display panel for displaying an image, a back light assembly for providing light to the liquid crystal display panel, and a control printed circuit for generating various electrical signals required for driving the liquid crystal display panel. It consists of a board (Control Printed Circuit Board; control PCB) and the like.

Recently, a light emitting diode package having high power saving and long life and excellent economic efficiency has been spotlighted as a backlight assembly. In the case of the liquid crystal display, since a plurality of light emitting diodes are integrated, heat generated during an operation process is reduced. A heat sink is essential for rapid release.

Since the heat sink is mainly air-cooled, that is, the heat sink and the heat sink of the heat sink are in contact with each other to radiate heat, effective heat dissipation is possible only when a smooth air flow in the system is maintained. However, the liquid crystal display panel disposed on the top of the heat sink and the control PCB disposed on the bottom of the heat sink are electrically connected by a flexible printed circuit (FPC) having a wide width. This was inhibited and there was a problem that the heat radiation effect by the heat sink is reduced. If the heat generated from the light emitting diode package is not effectively radiated, the accumulated heat degrades the light emitting diode, resulting in a decrease in output and a shortened life, and a rise in temperature in the entire system, causing malfunctions of various electrical elements. Since it causes a problem, it is urgent to secure effective heat dissipation technology in the case of the liquid crystal display.

Accordingly, an object of the present invention is to provide a new structure of FPC, a method of manufacturing the same, and a display device having the same, which can achieve heat dissipation in a system by minimizing the width of the FPC to improve the air flow in the system.

In the flexible printed circuit according to the present invention for achieving the above object, the flexible printed circuit comprising a first and a second terminal portion formed on both ends and a wiring portion connecting the first and second terminal portion, the first, The width of the area | region in which the said wiring part was formed compared with the area | region in which the 1st, 2nd terminal part was formed, and the 2nd terminal part is provided with the some connection terminal, and the said wiring part is provided with the some metal wiring corresponding to the said some connection terminal. It is characterized by being narrowly formed.

It is preferable that the said wiring part is formed between the base film and cover film which have insulation and flexibility.

The plurality of metal wires may be formed in the same layer, or may be formed in another layer with an insulating film interposed therebetween.

A connector may be mounted on at least one side of the first and second terminal units.

The method for manufacturing a flexible printed circuit according to the present invention for achieving the above object comprises the steps of forming a metal thin film on a base film, patterning the metal thin film and disposed at a wide area at both ends of the base film. Forming a plurality of metal wires so as to be disposed in a narrow area in the central portion, laminating a cover film on the metal wires, and removing the outer regions of the base film and the cover film on which the metal wires are not formed. It characterized in that it comprises a step of forming a narrow width of the central portion as compared to both ends.

It is preferable to form the said base film by any one of a polyimide film, a polyester film, and a polyparavinic acid film.

The forming of the metal wiring may include forming a multilayer by repeating a process of forming an upper metal wiring through an insulating film and then again forming the lower metal wiring.

A display device according to the present invention for achieving the above object is a display panel for outputting an image, a heat sink provided for heat dissipation, a circuit board for generating an electrical signal for driving the display panel and the display panel And a flexible printed circuit electrically connecting the circuit board, wherein the flexible printed circuit includes first and second terminal portions formed at both ends and a wiring portion connecting the first and second terminal portions. The second terminal portion includes a plurality of connection terminals, and the wiring portion includes a plurality of metal wires corresponding to the plurality of connection terminals, and a width of an area in which the wiring portion is formed compared to a region in which the first and second terminal portions are formed. It is characterized by being narrowly formed.

The display panel uses a liquid crystal display panel, and further comprises a backlight assembly for providing light to the liquid crystal display panel.

And a data PCB electrically connected to the data line of the liquid crystal display panel and a gate PCB connected to the gate line, wherein the flexible printed circuit is electrically connected to at least one of the data PCB and the gate PCB. .

The backlight assembly may include a light emitting diode package having a plurality of light emitting diodes and a reflective surface formed thereon, an operating circuit of the light emitting diode embedded therein, and a heat radiation pad attached to the bottom thereof.

The heat sink may further include a heat sink in contact with the atmosphere and a heat radiating fan forcibly circulating the atmosphere.

It is preferable that the said wiring part is formed between the base film and cover film which have insulation and flexibility.

The plurality of metal wires may be formed in the same layer, or may be formed in another layer with an insulating film interposed therebetween.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention;

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art the scope of the invention. It is provided for complete information. Like reference numerals in the drawings refer to like elements.

<First Embodiment>

1 is a plan view showing an FPC according to a first embodiment of the present invention, Figure 2 is a cross-sectional view taken along the line AA 'of Figure 1, Figure 3 is a modification of the FPC according to a first embodiment of the present invention It is a top view which showed the example.

Referring to FIG. 1, the FPC includes a base film 110 having flexibility and insulation, first and second terminal parts 130 and 140 formed at both ends of the base film 110, and the first and second terminal parts ( 130 and 140 may be electrically connected to each other, and the width of the region in which the wiring portion 120 is formed is narrower than the region in which the first and second terminal portions 130 and 140 are formed. Is formed.

The wiring portion 120 includes a plurality of metal wirings, for example, the first and second metal wirings 121 and 122 in the present embodiment. The wiring unit 120 may include a dummy wiring for a test in addition to the signal wiring for signal transmission. The metal wires 121 and 122 may be formed by patterning a conductive material.

The first and second terminal portions 130 and 140 include a plurality of connection terminals, for example, the first, second, third and fourth connection terminals 131, 132, 141 and 142 in this embodiment. The connection terminals 131, 132, 141, and 142 are formed at both ends of the metal wires 121 and 122 to be electrically connected to the metal wires 121 and 122. The connection terminals 131, 132, 141, and 142 may be formed by exposing a part of the metal wires 121 and 122, or may form a via hole or a contact hole connected to the metal wires 121 and 122, and may be plated therein. It can also form by implementing.

The first signal transmission path for electrically connecting both external circuits includes a first connection terminal 131, a first metal wire 121, and a third connection terminal 141, and the second signal transmission path includes a second connection. The terminal 132 includes a second metal wire 122 and a fourth connection terminal 142. The signal transmission paths are preferably formed in the same number corresponding to the number of both external circuits connected thereto. Here, although the case in which the signal transmission path is formed in a 2: 2 connection structure has been illustrated, the present invention is not limited thereto, and the signal transmission path may be formed in various connection structures. For example, it may be formed as a multi-connected structure such as 3: 3, 4: 4, and the like.

A connector 145 may be mounted on at least one side of the first and second terminal parts 130 and 140 to facilitate connection with an external circuit. That is, a corresponding connector 145 that can be connected to a connector mounted on an external circuit is prepared and placed in a predetermined mounting position, and mounted using a conductive material such as an anisotropic conductive film (ACF), or a wire. It is mounted by bonding (soldering) or soldering (wire bonding).

 Referring to FIG. 2, metal lines 121 and 122 are formed between a base film 110 and a cover film 150. The base film 110 serves as a base material on which the metal wires 121 and 122 are formed, and the cover film 150 is coupled to face the base film 120 so that the metal wires 121 and 122 are contaminated by foreign matter or air. To be oxidized by

Referring to the manufacturing method of the FPC according to this embodiment as follows.

First, the base film 110 which has insulation and flexibility is prepared. As the base film 110, a polyimide film, a polyester film, a polyparavinic acid film, or the like can be used.

Subsequently, a patterning process is formed by applying an adhesive on the base film 110 to attach a metal thin film, then applying a photoresist on the metal thin film, and a series of processes such as exposure, development, and etching. Next, metal wirings 121 and 122 having a predetermined pattern are formed. In this case, the metal wires 121 and 122 may be formed in a wide area at both ends of the base film 110 and in a narrow area at the center part. In addition, the adhesive may be epoxy resin, NBR-phenol resin, phenol-butalal resin, epoxy-NBR resin, epoxy-phenol resin, epoxy-nylon resin, epoxy-polyester resin, epoxy-acrylic Thermosetting resins such as resins, acrylic resins, polyamide-epoxy-phenolic resins, polyimide resins, and silicone resins can be used, and copper, aluminum, iron, nickel and the like can be used as the metal thin film.

Subsequently, a cover film 150 is attached onto the metal wires 121 and 122. As the cover film 150, a material formed by applying an adhesive to a lower portion of the base film having the above-described insulation and flexibility may be used.

Subsequently, a predetermined area of the cover film 150 is removed using a grinder to expose the metal wires 121 and 122, or an area of the cover film 150 is etched using an etchant to form the metal wire ( Connection terminals 131, 132, 141, and 142 are formed in such a manner as to expose 121 and 122. In this case, via holes or contact holes may be formed on the cover film 150, and the connection terminals 131, 132, 141, and 142 may be formed by plating the via holes or contact holes.

Subsequently, an outer region of the base film 110 and the cover film 150 in which the metal wirings 121 and 122 and the connection terminals 131, 132, 141, and 142 are not formed is removed, thereby manufacturing an FPC having a structure having a narrow width at the center thereof compared to both ends. Accordingly, when the connector 145 for easy connection with an external circuit is mounted on some connection terminals 141 and 142, the FPC according to the present embodiment is manufactured.

The FPC according to the present embodiment has an advantage of minimizing the occupied space in the system because the width of the center portion is narrower than both ends. In particular, when the FPC is used in a system having a heat sink therein, the heat dissipation effect can be enhanced since the FPC is not inhibited.

As described above, the FPC of the X-shaped shape and the monolayer structure is illustrated in the first embodiment, but the FPC according to the present invention is not limited thereto and may be modified in various shapes and structures. For example, as shown in FIG. 3, it may be formed in an I-shape that is not separated at both ends, and the metal wiring may be formed in a multilayer structure. Hereinafter, one example of such a possibility will be described with reference to the drawings. In this case, description overlapping with the foregoing embodiment will be omitted.

Second Embodiment

4 is a plan view showing an FPC according to a second embodiment of the present invention, Figure 5 is a cross-sectional view taken along the line BB 'of FIG.

4 and 5, the FPC also has a base film 110 having flexibility and insulation, first and second terminal parts 130 and 140 formed at both ends of the base film 110, and the first and second parts. And wiring portions 121 and 122 electrically connecting the two terminal portions 130 and 140, and the width of the region in which the wiring portions 121 and 122 are formed is narrower than the region in which the first and second terminal portions 130 and 140 are formed. It is formed in X-shape.

However, in the FPC, the wiring parts 121 and 122 are formed in multiple layers. That is, the first metal wire 121 and the second metal wire 122 are electrically insulated by the insulating film 160, and both surfaces of the insulating film 160 are formed of the base film 110 and the cover film 150. Covered

Referring to the manufacturing method of the FPC according to this embodiment as follows. In this case, the content overlapping with the above-described content in the above embodiment will be briefly described.

First, the base film 110 is prepared, a metal thin film is attached onto the base film 110, and then patterned to form the first metal wire 121. Subsequently, the insulating film 160 is attached on the first metal wire 121, the metal thin film is attached on the insulating film 160, and then patterned to form the second metal wire 122. Subsequently, the cover film 150 is attached on the second metal wire 122, and predetermined regions, that is, both end regions of the first and second metal wires 121 and 122 are exposed to form the connection terminals 131, 132, 141, and 142. In this case, via holes or contact holes may be formed on the cover film 150 or the cover film 150 and the insulating film 160, and the connection terminals 131, 132, 141 and 142 may be formed by plating the via holes or the contact holes. It may be. Subsequently, the outer regions of the base film 110, the insulation film 160, and the cover film 150 on which the first and second metal wires 121 and 122 and the connection terminals 131, 132, 141, and 142 are not formed are removed, and thus the center portions of the center and the second If the FPC of a narrow structure is manufactured, and the connector 145 for easy connection with an external circuit is mounted in some connection terminals 141 and 142 as needed, the FPC which concerns on this embodiment is manufactured.

The FPC according to the present exemplary embodiment has the advantage of minimizing the occupied space of the FPC in the system since the metal wirings 121 and 122 are formed in a multi-layer, so that the width of the center portion can be made narrower than both ends. .

Third Embodiment

6 is an exploded perspective view of a liquid crystal display device with an FPC according to the present invention, and FIG. 7 is a combined perspective view of the liquid crystal display device shown in FIG. 6.

6 and 7, the liquid crystal display includes a liquid crystal display panel 620 for displaying an image, a backlight assembly 660 for providing light to the liquid crystal display panel 620, and the backlight assembly ( A heat sink 690 for dissipating heat generated by the heat sink 660 and a control PCB 700 for generating an electrical signal for driving the liquid crystal display panel 620.

Although not shown, the liquid crystal display panel 620 includes a liquid crystal layer interposed between the upper substrate and the lower substrate disposed to face each other. The upper substrate is a transparent substrate in which a plurality of RGB color filters that implement color by coloring light incident in the pixel region and a plurality of black matrices that block light incident on the non-pixel region are arranged in a matrix form. A common electrode formed of a transmissive conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is formed on an opposite surface of the upper substrate. The lower substrate is a transparent substrate in which a plurality of thin film transistors (TFTs), which are switching elements, are arranged in a matrix form. A data line is connected to a source electrode of the thin film transistors, a gate line is connected to a gate electrode, and a pixel electrode formed of a light transmissive conductive material such as ITO or IZO is connected to a drain electrode.

The backlight assembly 660 includes a light source unit 663 that generates light, a diffusion sheet 662 and an optical sheet 661 disposed above the light source unit 663.

The light source unit 663 has a plurality of light emitting diodes 663a and a reflective surface 663b formed thereon, an operating circuit of the light emitting diodes 663a is embedded therein, and a heat radiation pad 663c has light emission attached thereto. Diode packages are available. Of course, the light source unit 663 may be configured by arranging a plurality of cold cathode lamps under the diffusion sheet 662 in various forms, for example, replacing the diffusion sheet 662 with a light guide plate and one side of the light guide plate. It is also possible to arrange the cold cathode tube lamp in the.

The heat sink 690 releases heat transferred from the light source unit 660 to the atmosphere to assist the light source unit 660 to operate at an appropriate temperature. The heat sink 690 includes a body 691 in contact with the heat source and a heat sink 692 in contact with the atmosphere. If the heat dissipation by natural convection is not sufficient, it is preferable to add a heat dissipation fan (not shown) to a predetermined region of the heat dissipation plate 692 to switch to forced convection.

The liquid crystal display panel 620 is accommodated in a storage space provided by the upper chassis 610 and the upper frame 650, and the backlight assembly 660 is a storage provided by the lower frame 670 and the lower chassis 680. It is housed in space and fixed respectively. In addition, the heat sink 690 is attached to and fixed to the rear surface of the lower chassis 680.

The upper chassis 610 includes an opening surface through which the liquid crystal display panel 620 is exposed and a side wall extending from an edge of the opening surface to provide an accommodation space in which the upper frame 650 is accommodated. In particular, a seating area of the liquid crystal display panel 620 is defined in the upper frame 650, and is formed to surround the liquid crystal display panel 620 so as to prevent the liquid crystal display panel 620 from being separated or damaged due to an external impact. do.

The lower chassis 680 includes a bottom surface to which the light source unit 663 is attached and a side wall extending from an edge of the bottom surface to provide an accommodation space in which the lower frame 670 is accommodated. In particular, the lower frame 670 is provided with a step 671, and the optical sheet 661 and the diffusion sheet 662 are seated on the upper step 671, and the light source unit 663 is disposed below the step 671. It is received and fixed at the designated position.

The data PCB 630 and the gate PCB 640 are connected to the liquid crystal display panel 620, and the data PCB 630 is electrically connected to the control PCB 700 through the FPCs 710; 710a and 710b. Receive a predetermined signal.

The data PCB 630 is electrically connected to a data line formed on the liquid crystal display panel 620 to transmit a gray voltage, and the gate PCB 640 is electrically connected to a gate line to transmit a driving signal. Of course, the data PCB 630 and the gate PCB 640 may be integrated into one.

The control PCB 700 includes a timing controller circuit, a voltage drop circuit, an AD converting circuit, and the like, and converts an image signal and a supply power applied from the outside into a drive signal and an operation power suitable for driving the liquid crystal display panel 620. The data is transferred to the PCB 630 and the gate PCB 640.

Various electrical signals generated by the control PCB 700 are transmitted to the data PCB 630 through the FPC 710. In this case, the FPC 710 includes first and second terminal portions formed at both ends and a wiring portion connecting the first and second terminal portions, and the first and second terminal portions include a plurality of connection terminals. The part includes a plurality of metal wires corresponding to the plurality of connection terminals, and has a narrower width than the area in which the first and second terminal parts are formed. That is, it is preferable to use FPCs according to the first and second embodiments described above. Of course, various electrical signals generated by the control PCB 700 may be connected to the gate PCB 640 through the FPC 710, and may be connected to both the gate PCB 640 and the data PCB 630.

In the liquid crystal display according to the present exemplary embodiment having the above configuration, heat generated in the light source unit 663 is transferred to the heat sink 690 through the lower chassis 680, and the heat sink 692 of the heat sink 690 is provided. Since the light source unit 663 may be operated at an appropriate temperature by being emitted into the atmosphere through the air, there is an advantage in that output reduction and life shortening due to deterioration of the light source unit 663 may be prevented. In particular, the FPC 710 disposed across one side of the heat sink 690 to connect the liquid crystal display panel 620 and the control PCB 700 is formed to have a narrow width so as not to disturb the air flow in the system. It does not cause a decrease in performance.

 Meanwhile, in the present exemplary embodiment, the liquid crystal display is described as an example of the display device. However, if the system requires heat dissipation due to a heat source therein, other display devices may include, for example, a plasma display panel (PDP), The present invention can also be applied to various display devices such as organic electroluminescence display (OLD).

As described above, the above embodiments are disclosed for purposes of illustration, and those skilled in the art will appreciate that various modifications, improvements, substitutions, and additions may be made without departing from the spirit of the present invention. Accordingly, the technical scope of the present invention is defined by the appended claims.

The present invention can improve the air flow in the system because it provides a narrow FPC in the center portion as compared to both ends. Incidentally, the space utilization in the system can be increased. In addition, in the case of a display device using a plurality of light emitting diodes as a backlight, effective heat dissipation is possible, thereby preventing output degradation and lifespan reduction due to deterioration of the light emitting diodes, and applying to manufacturing a larger display device. have.

Claims (16)

A flexible printed circuit comprising first and second terminal portions formed at both ends and a wiring portion connecting the first and second terminal portions, The first and second terminal units include a plurality of connection terminals, The wiring portion includes a plurality of metal wires corresponding to the plurality of connection terminals, And a width of a region where the wiring portion is formed is narrower than a region where the first and second terminal portions are formed. The method according to claim 1, And the wiring part is formed between the base film and the cover film having insulation and flexibility. The method according to claim 1, And the plurality of metal wires are formed in the same layer. The method according to claim 1, And the plurality of metal wires are formed in different layers with an insulating film interposed therebetween. The method according to claim 1, A flexible printed circuit, characterized in that a connector is mounted on at least one side of the first and second terminal portions. Forming a metal thin film on the base film; Patterning the metal thin film to form a plurality of metal wires so as to be disposed in a wide area at both ends of the base film and in a narrow area at the center part; Stacking a cover film on the metal wiring; And removing the outer regions of the base film and the cover film on which the metal wires are not formed to form a narrow width of the center portion relative to both ends thereof. The method according to claim 6, The base film is formed of any one of a polyimide film, polyester film, polyparavinic acid film. The method according to claim 6, Forming the metal wires, A method of manufacturing a flexible printed circuit comprising: forming a lower metal wiring, and then forming a multilayer by repeating a process of forming an upper metal wiring through an insulating film. A display panel for outputting an image, A heat sink provided for heat dissipation, A circuit board generating an electrical signal for driving the display panel; A flexible printed circuit electrically connecting the display panel and the circuit board; The flexible printed circuit includes first and second terminal portions formed at both ends and a wiring portion connecting the first and second terminal portions, the first and second terminal portions include a plurality of connection terminals, and the wiring portion is A display device comprising a plurality of metal wires corresponding to the plurality of connection terminals, wherein a width of a region where the wiring portion is formed is narrower than a region where the first and second terminal portions are formed. The method according to claim 9, The display panel uses a liquid crystal display panel, And a backlight assembly providing light to the liquid crystal display panel. The method according to claim 10, And a data PCB electrically connected to a data line of the liquid crystal display panel and a gate PCB connected to a gate line, wherein the flexible printed circuit is electrically connected to at least one of a data PCB and a gate PCB. Display device. The method according to claim 10, The backlight assembly, And a light emitting diode package having a plurality of light emitting diodes and reflecting surfaces formed thereon, an operating circuit of the light emitting diodes embedded therein, and a heat dissipation pad attached to the bottom thereof. The method according to claim 9, The heat sink is, And a heat sink in contact with the atmosphere, and a heat radiating fan forcibly circulating the atmosphere. The method according to claim 9, And wherein the wiring portion is formed between the base film and the cover film having insulation and flexibility. The method according to claim 9, And the plurality of metal wires are formed on the same layer. The method according to claim 9, And the plurality of metal wires are formed in different layers with an insulating film interposed therebetween.

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