KR20070033507A - Flexible printed circuit film and liquid crystal display comprising the same - Google Patents

Abstract

A flexible printed circuit film and an LCD including the same are provided to prevent malfunction of an apparatus by reducing EMI(electromagnetic interference). A line pattern(120) having a plurality of signal lines is formed on a base film(110). An insulating passivation layer(150) is formed on the line pattern. A conductive tape(160) is disposed on the insulating passivation layer and is electrically connected with a ground line of the line pattern. The conductive tape is electrically connected with the ground line by partially removing the insulating passivation layer that is formed on the ground line. A connection part is formed at one end of the base film and is electrically connected with a printed circuit board through a connecter.

Description

Flexible printed circuit film and liquid crystal display comprising the same

1 is a partial perspective view showing a portion of a liquid crystal panel unit using a flexible printed circuit film according to an embodiment of the present invention.

FIG. 2 is an enlarged view of part II of FIG. 1.

3 is a cross-sectional view taken along line III-III ′ of FIG. 2.

4 is a partial perspective view of a liquid crystal display including the liquid crystal panel unit of FIG. 1.

(Explanation of symbols for the main parts of the drawing)

1: first display panel 3: second display panel

5: liquid crystal panel 6: gate drive IC

7: Gate Drive Signal Input Pads 8: Data Drive IC

9: data drive signal input pads 10: liquid crystal panel unit

20: printed circuit board 100: flexible printed circuit film

110: base film 120: wiring pattern

130: connection portion 140: pad portion

150: insulating protective film 160: conductive tape

The present invention relates to a flexible printed circuit film and a liquid crystal display including the same, and more particularly, to a flexible circuit board capable of reducing interference characteristics caused by electromagnetic waves and a liquid crystal display including the same.

In general, a liquid crystal display device includes a liquid crystal panel including a first display panel, a second display panel facing the first display panel, and a liquid crystal injected between the two substrates, and using light modulation by a change in optical characteristics of the liquid crystal. It is a device for displaying information

In the first display panel, a plurality of gate lines and a plurality of data lines cross each other, and thin film transistors and pixel electrodes, which are switching elements, are formed in the crossed regions, respectively.

Here, in order to apply a driving signal to the data line and the gate line, a printed circuit board (PCB) having various semiconductor elements and components mounted thereon, and a driving IC transferring the driving signal to the gate line and the data line And the liquid crystal panel displaying the information must be interconnected.

A method of interconnecting a liquid crystal panel, a printed circuit board, and a driving IC is largely classified into a chip on glass (COG) mounting method and a tape automated bonding (TAB) mounting method.

The COG mounting method is a method of mounting a driving IC on a liquid crystal panel and connecting a liquid crystal panel and a printed circuit board using a connector such as a flexible printed circuit film (FPC).

At this time, the flexible printed circuit film has a number of lines formed in a very narrow width for the electrical connection with the liquid crystal panel.

In addition, since most of the driving devices mounted on the printed circuit board are operated by high frequency, it causes electromagnetic waves (Electro Magnetic Interference) or electrostatic discharge (ESD). In addition, the electromagnetic waves not only interfere with electrical signals transmitted to the liquid crystal panel, but also are emitted to the outside of the liquid crystal display to cause malfunction of other peripheral devices.

Therefore, a method for reducing the interference characteristics caused by electromagnetic waves is required.

It is an object of the present invention to provide a flexible printed circuit film capable of reducing interference characteristics caused by electromagnetic waves.

Another object of the present invention is to provide a liquid crystal display device including the flexible printed circuit film.

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

A flexible printed circuit film according to an embodiment of the present invention for achieving the above technical problem, a wiring pattern having a base film, a plurality of signal lines formed on the base film, and the wiring pattern is formed on the wiring An insulating protective film for protecting the pattern, and a conductive tape positioned on the insulating protective film, and electrically connected to the ground wiring of the wiring pattern.

According to another aspect of the present invention, there is provided a liquid crystal display device including a first display panel on which a driving IC is mounted, and a liquid crystal display including a second display panel coupled through a liquid crystal between the first display panel. A wiring pattern having a panel, a backlight unit for providing light to the liquid crystal panel, a printed circuit board for generating driving and control signals for the liquid crystal panel, a base film, and a plurality of signal lines formed on the base film; A flexible printed circuit film comprising: an insulating protective film formed on the wiring pattern to protect the wiring pattern; and a conductive tape positioned on the insulating protective film and electrically connected to the ground wiring of the wiring pattern. And a flexible printed circuit film connecting the panel and the printed circuit board.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Examples of the liquid crystal display used in the present invention include a portable multimedia player (PMP), a personal digital assistant (PDA), a portable digital player (DVD) player, a mobile phone, a notebook computer, and a digital TV. For convenience of explanation, the liquid crystal display of the present invention will be described using a TV. However, the present invention is not limited thereto and may be applied to various liquid crystal display devices.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a partial perspective view showing a part of a liquid crystal panel unit using a flexible printed circuit film according to an embodiment of the present invention, FIG. 2 is an enlarged view of part II of FIG. 1, and FIG. 3 is III of FIG. 2. It is sectional drawing of the ~ III 'part.

Referring to FIG. 1, a liquid crystal panel unit 10 of a liquid crystal display device receives an electrical signal from an external liquid crystal panel 5 for displaying information and a printed circuit board transferring driving and control signals to the liquid crystal panel 5. And a flexible printed circuit film 100, which is a signal transmission film that connects the liquid crystal panel 5 and the printed circuit board 20 to drive the liquid crystal panel 5.

The liquid crystal panel 5 is composed of a first display panel 1, a second display panel 3 attached to the first display panel 1, and a liquid crystal (not shown) injected between both display panels 1 and 3. . Here, the second display panel 3 is formed to be smaller than the size of the first display panel 1 so that a predetermined region of one end in the width direction and the longitudinal direction of the first display panel 1 is exposed to the outside of the second display panel 3.

A plurality of gate lines (not shown) are arranged in a line along the width direction on the first display panel 1, and a plurality of data lines (not shown) are arranged in a line along the length direction so as to cross the gate lines. . Thin film transistors and pixel electrodes (not shown), which are switching elements, are formed in the intersection regions of the gate lines and the data lines, respectively.

Liquid crystal injected between the pixel electrode and the common electrode (not shown) of the second display panel by driving gate lines and data lines in a predetermined region of the first display panel 1 exposed by the second display panel 3. A gate drive IC 6 and a data drive IC 8 that control the arrangement of the arrays are formed. In addition, gate driving signal input pads 7 and data driving signal input pads 9 are formed adjacent thereto.

In the second display panel 3, red, green, and blue pixels, in which color is expressed as light passes, are formed, and indium tin oxide (ITO) or indium is formed on the entire surface of the second display panel 3. A common electrode made of indium zinc oxide (IZO) is formed.

The printed circuit board 20 is composed of a gate printed circuit board electrically connected to the gate drive signal input pads 7 and a data printed circuit board electrically connected to the data drive signal input pads 9. Gate and data printed circuit boards are typically formed of a multilayer printed circuit board in which a plurality of substrates having conductor patterns formed thereon are stacked in a plurality of layers and the conductor patterns of each layer are electrically interconnected by via holes (not shown). do.

In addition, a plurality of electronic components 21 are mounted to generate driving and control signals of the liquid crystal panel 5. Here, the plurality of electronic components 21 are mostly operated by high frequency signals, which causes electromagnetic waves (Electro Magnetic Interference). In order to solve this problem, it is possible to use a method of grounding the storage container.

The flexible printed circuit film 100 electrically connects the printed circuit board 20, the gate driving signal input pads 7 and the data driving signal input pads 9 of the first display panel 1.

The present invention is limited to the case where the gate printed circuit board and the flexible printed circuit film 100 is connected for convenience of description, but it can be applied to the data printed circuit board.

Hereinafter, the flexible printed circuit film will be described in detail with reference to FIGS. 2 and 3.

The flexible printed circuit film 100 is formed by forming a conductor pattern on a film having flexibility and insulation, for example, a base film 110 having a polyimide material, and a plurality of signal lines capable of transmitting electrical signals. The wiring pattern 120 is formed of a structure including a connection portion 130 and a pad portion 140 formed at one end and the other end of the base film 110 around the wiring pattern 120, respectively.

In addition, the insulating protection film 150 is formed on the wiring pattern 120, and the insulating protection film 150 further includes a conductive tape 160 electrically connected to the ground wire of the wiring pattern 120.

The wiring pattern 120 is formed to a thickness of about 5 to 20 μm, and generally a metal material such as copper foil (Cu) is used. Preferably, the surface of the copper foil is plated with tin, gold, nickel or solder. Conduct.

A method of forming copper foil, which is an example of such a wiring pattern 120, includes casting, laminating, electroplating, and the like. Here, casting is a method of spraying a liquid base film on a rolled copper foil to perform thermal curing, and laminating is a method of placing a base film rolled copper foil and thermocompressing it. In addition, electroplating is a method of forming a copper foil by depositing a copper seed layer on the base film and putting the base film in an electrolyte in which copper is melted and flowing electricity. Here, the wiring patterned on the copper foil is formed to form a predetermined circuit by selectively etching the copper foil by performing a photo / etching process on the copper foil.

In addition, an insulating protective film 150 is formed on the wiring pattern 120 to protect the wiring pattern 120 from external impact or corrosion. Solder resist may be representatively used as the insulating protective film 150.

The connection part 130 formed at one end of the wiring pattern 120 of the flexible printed circuit film 100 is connected to the printed circuit board 20 and is a part for electrical connection. In addition, a driving signal is transmitted from the printed circuit board 20 through the connection unit 130. A connection method using the connector 25, a soldering connection method using bumps, or the like is used for the connection between the connection portion 130 and the printed circuit board 20. In the present embodiment, a connection method using a connector has been described as an example. However, the present invention is not limited thereto, and the connection method of the flexible printed circuit film and the printed circuit board may use all known techniques.

The pad part 140 formed at the other end of the wiring pattern 120 of the flexible printed circuit film 100 is connected to the first display panel 1 of the liquid crystal panel 5 and is an electrical connection part. The pad part 140 includes a conductive pattern part 145.

The conductive pattern part 145 is a part for electrical connection with the first display panel 1, and the driving ICs 6 mounted on the first display panel 1 to drive signals generated from the printed circuit board 20 are provided. 8) pass on. A plurality of conductive patterns are formed in the conductive pattern unit 145, and the conductive patterns are connected to the input patterns 7 and 9 on the first display panel 1. At this time, a connection method using an anisotropic conductive film (ACF) 200 or the like is used.

In addition, the conductive tape 160 is adhered to the top surface of the insulating protective film 150.

The conductive tape 160 is made of a composite weave of a normal fiber and a conductive fiber to make soft and flexible, and then an adhesive is coated on both sides to be attached to the flexible printed circuit film 100. The conductive tape 160 is in electrical contact with the ground wiring of the wiring pattern 120.

More specifically, referring to FIG. 3, the flexible printed circuit film 100 may have the base film 110, the wiring pattern 120, the insulating protective film 150, the conductive tape 160, and the like as described above. The conductive tape 160 is adhered to an upper surface of the insulating protective film 150. In addition, the ground wiring of the wiring pattern 120 is in electrical contact with the conductive tape 160, at which time the insulating protective film 150 is partially removed to connect the ground wiring and the conductive tape 160 (FIG. 3A). part). This may provide an effect of shielding electromagnetic waves emitted to the outside by the wiring pattern 120, and may also ground unnecessary components such as electromagnetic waves through the ground wiring.

4 is an exploded perspective view of a liquid crystal display including the liquid crystal panel unit of FIG. 1.

For convenience of description, members having the same functions as the members shown in the drawings shown in FIGS. 1 to 3 are denoted by the same reference numerals, and thus description thereof is omitted.

Referring to FIG. 4, the liquid crystal display device 400 according to the exemplary embodiment of the present invention generally has a liquid crystal panel unit 10, a backlight unit 30, an upper storage container 90, and a lower storage container 80. It includes.

As described above, the liquid crystal panel unit 10 includes a liquid crystal panel 5, a gate driving IC 6, a data driving IC 8, a printed circuit board 20, a flexible printed circuit film 100, and the like. do.

The backlight unit 40 is positioned below the liquid crystal panel unit 30 and includes the optical sheets 50, the lamp unit 60, the reflector 70, and the like. In addition, the lamp unit 60 is composed of a lamp 50 and the lamp holder 55.

The lamp 50 is an external electrode fluorescent lamp having an external electrode 53 formed at both ends of a rod-shaped lamp tube 51. In addition, a discharge gas is injected into the lamp tube 51, and the external electrode 53 is formed of a conductive material to surround the outside of the lamp tube 51. The lamp 50 generates light by the lamp driving voltage applied from the outside to the external electrode 53 of the lamp 50.

In addition, the lamps 50 are spaced at a uniform distance and connected in phase in parallel, and are configured in a direct type. Therefore, the light guide plate may be omitted because light is dimmed directly on the front surface of the liquid crystal panel 5.

The lamp holder 55 is located at both ends of the lamp 50 to support and fix the lamp 50. In addition, a predetermined driving voltage is applied to the external electrode 53 of the lamp 50, and voltage applying means (not shown) is provided to prevent the external electrode 53 from being separated.

The optical sheets 40 are positioned on the lamp 50.

The optical sheets 40 serve to diffuse and collect light transmitted from the lamp 50, and may be configured by a plurality of sheets, such as a diffusion sheet and a prism sheet. The diffusion sheet here prevents the light from being partially concentrated by dispersing the light incident from the lamp 50. In addition, the prism sheet has a triangular prism with a predetermined arrangement on the upper surface, and is usually composed of two sheets, and each prism arrangement is arranged so as to cross each other at a predetermined angle so that the light diffused from the diffusion sheet is liquid crystal. Condenses in a direction perpendicular to the panel. As a result, the light passing through the prism sheet almost runs vertically so that the luminance distribution on the protective sheet is uniformly obtained. The protective sheet formed on the prism sheet not only serves to protect the surface of the prism sheet, but also diffuses light in order to uniformize the distribution of light.

In addition, a reflector 70 is installed below the lamp 50.

The reflector 70 reflects light emitted to the bottom of the lamp 50 upwards. The reflective plate 70 may be integrally formed on the bottom surface of the lower storage container 80. That is, the lower receiving container 80 may be made of a material having high reflectivity such as aluminum (Al) or an aluminum alloy so that the lower receiving container 80 may perform a function of the reflecting plate 70.

The upper accommodating container 90 is fastened to the lower accommodating container 80 to fix the backlight unit 30 including the optical sheets 40, the lamp unit 60, the reflecting plate 70, and the like. In addition, a stepped portion on which the liquid crystal panel unit 10 is seated is formed on an upper surface of the upper storage container 90.

The upper receiving container 90 and the lower receiving container 80 may be coupled through a hook (not shown). For example, a hook is formed along the outer surface of the side wall of the lower receiving container 80. A corresponding hook insertion hole (not shown) may be formed on the side of the upper storage container 90. Therefore, as the upper storage container 90 descends from above the lower storage container 80, the hook formed in the lower storage container 80 enters the hook insertion hole of the upper storage container 90, thereby lowering the storage container 80. And the upper storage container 90 may be fastened. In addition, the combination of the upper container 90 and the lower container 80 may be modified in any known form.

In the present embodiment, the direct type backlight unit 30 has been described as an example, but the present invention is not limited thereto, and any known backlight unit may be used.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

As described above, according to the flexible printed circuit film and the liquid crystal display including the same, it is possible to reduce the interference of electromagnetic waves to prevent malfunction of the device.

Claims (8)

Base film; A wiring pattern having a plurality of signal lines formed on the base film; An insulating protective film formed on the wiring pattern; And And a conductive tape on the insulating protective layer, the conductive tape being electrically connected to the ground wiring of the wiring pattern. According to claim 1, And the insulating protective film formed on the ground wiring is partially removed to electrically connect the conductive tape and the ground wiring. According to claim 1, A flexible printed circuit film formed on one end of the base film, further comprising a connecting portion electrically connected by a printed circuit board and a connector. According to claim 1, And a pad portion formed at the other end of the base film and having a conductive pattern portion electrically connected by a liquid crystal panel and an anisotropic conductive film. A liquid crystal panel comprising a first display panel on which a driving IC is mounted, and a second display panel coupled through a liquid crystal between the first display panel; A backlight unit providing light to the liquid crystal panel; A printed circuit board generating driving and control signals of the liquid crystal panel; And A conductive film having a base film, a wiring pattern having a plurality of signal lines formed on the base film, an insulating protective film formed on the wiring pattern, and an insulating protective film and electrically connected to the ground wiring of the wiring pattern. A flexible printed circuit film comprising: a liquid crystal display device comprising a flexible printed circuit film connecting the liquid crystal panel and the printed circuit board. The method of claim 5, And the insulating protective film formed on the ground line is partially removed to electrically connect the conductive tape and the ground line. The method of claim 6, And a connecting portion formed at one end of the base film and electrically connected to the printed circuit board by a connector. The method of claim 6, And a pad portion formed at the other end of the base film and having a conductive pattern portion electrically connected to the liquid crystal panel by the anisotropic conductive film.

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