KR20070079484A - Flexible printed circuit film and backlight assembly including the same and liquid crystal display including the same - Google Patents

Abstract

A flexible printed circuit film, a backlight assembly including the same and an LCD(Liquid Crystal Display) including the film and the assembly are provided to form the length of terminals in the flexible printed circuit film differently, thereby improving the badness of the LCD. A base film(142) is made of insulating materials. A terminal member(145) includes the first terminal formed at a side of the base film. The second terminal is formed at the other side of the base film and electrically connected with the first terminal. The length of the first and second terminals is different from each other. A wire pattern(143) is formed on the base film and connected with the terminal member. A light source is mounted on a flexible printed circuit film and generates the light beam. A PCB(Printed Circuit Board) generates the driving signal of the light source and has a pad connected with the flexible printed circuit film. A light guide panel is located adjacent to a side of the light source and transmits uniformly the light beam upwardly. A receiving container receives the flexible printed circuit film, the light source and the light guide panel.

Description

Flexible printed circuit film and backlight assembly including the same and liquid crystal display including the same}

1 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is an enlarged perspective view of the flexible circuit film used in FIG. 1.

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

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

100: liquid crystal display 110: liquid crystal panel

111: second display panel 113: first display panel

115: drive IC 117: flexible printed circuit board

120: liquid crystal panel assembly 130: backlight assembly

140: light source unit 141: flexible circuit film

142: base film 143: wiring pattern

144: insulating protective film 145: terminal portion

145a: first terminal 145b: second terminal

146: via hole 147: light source

151: optical sheets 152: light guide plate

153: reflective sheet 160: upper storage container

170: lower housing 180: printed circuit board

181: pad

The present invention relates to a flexible circuit film, a backlight assembly including the same, and a liquid crystal display including the same, and more particularly, to a flexible circuit film, a backlight assembly including the same, and a liquid crystal display including the same. It is about.

In recent years, with the rapid development of information technology and mobile communication technology, the development of display devices that can visually display information has also been made remarkably. Such display devices are projected, direct view, virtual image, and hologram according to their driving type. The direct view display is classified into a light emitting display which can emit light due to external factors and a light emitting display having a light emitting property.

In general, the liquid crystal display itself is a light-receiving element that emits light and does not form an image, but receives light from the outside to form an image, so that a separate light source, for example, a backlight, allows an image to be observed in a dark place. .

As a light source of the backlight assembly for the liquid crystal display device, a cold cathode fluorescent lamp (ELC), an electroluminescence (EL), a light emitting diode (LED), and the like are employed. Complementing the problems of cold cathode fluorescent lamps that require power or short-lived EL, they are relatively small, such as mobile phones, due to the advantages of low power consumption, uniform brightness, semi-permanent life, various colors, and miniaturization. It is adopted as the backlight of the display.

The light emitting diode light source is mounted on a flexible circuit film and positioned adjacent to one side of the light guide plate. In this case, the flexible printed circuit film is connected to a printed circuit board of the liquid crystal display to receive the driving signal of the light source. Such a flexible circuit film has a structure in which a wiring pattern and a terminal portion are formed on a base film, an insulating protective film is formed on the wiring pattern, and an insulating protective film is not formed on the terminal portion, thereby being exposed to the outside.

Here, the conventional flexible circuit film is formed to have the same length of the terminal portion exposed to the outside up and down, and thus disconnection of the terminal portion may occur due to the characteristics of the flexible circuit film that is bent, which causes defects in the liquid crystal display device. .

Therefore, a method for preventing disconnection of the flexible circuit film is required.

The technical problem to be achieved by the present invention is to provide a flexible circuit film capable of preventing disconnection.

Another technical problem to be achieved by the present invention is to provide a backlight assembly including such a flexible circuit film.

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

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.

The flexible circuit film according to an embodiment of the present invention for achieving the above technical problem is formed on the other surface of the base film of the insulating material, the first terminal formed on one surface of the base film, and the base film opposite to one surface And a terminal part electrically connected to the first terminal, the terminal part including a second terminal having a different length from the first terminal, and a wiring pattern formed on the base film and connected to the terminal part.

The backlight assembly according to an embodiment of the present invention for achieving the above another technical problem is formed on the other surface of the base film of the insulating material, the first terminal formed on one surface of the base film, and the base film opposite to one surface A terminal portion including a second terminal electrically connected to the first terminal and having a different length from the first terminal, a flexible circuit film including a wiring pattern formed on the base film and connected to the terminal portion, and on the flexible circuit film A printed circuit board having a light source mounted on the light source and generating a light signal, a driving signal of the light source, and having a pad connected to the flexible circuit film, and positioned adjacent to one side of the light source, and uniformly transmitting light from the light source. It includes a light guide plate for transmitting a light, a flexible circuit film, a light source and a storage container for receiving the light guide plate.

The liquid crystal display according to the exemplary embodiment of the present invention for achieving the another technical problem includes such a backlight assembly.

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.

In addition, liquid crystal displays used in the present invention include a portable multimedia player (PMP), a personal digital assistant (PDA), a digital versatile disk (DVD) player, a cellular phone, and the like. Hereinafter, for convenience of explanation, the display device of the present invention will be described using a mobile phone. However, the present invention is not limited thereto and includes the aforementioned display devices.

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

1 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the liquid crystal display 100 includes a liquid crystal panel assembly 120 and a backlight assembly 130 as a whole.

The liquid crystal panel assembly 120 may include a first liquid crystal panel 110 including a first display panel 113 and a second display panel 111, and a liquid crystal layer interposed between the first display panel 113 and the second display panel 111. Not shown) and the driving IC 115.

The first display panel 113 includes a plurality of gate lines, data lines, and pixel electrodes. The gate line extends in the row direction to transfer the gate signal, and the data line extends in the column direction to transfer the data signal. The pixel is connected to the gate line and the data line and includes a switching element and a storage capacitor.

Here, the switching element is formed at the intersection of the gate line and the data line, and the sustain capacitor and the liquid crystal capacitor are connected to the output terminal of the switching element. In addition, the switching element is implemented as a thin film transistor including amorphous silicon and poly-silicon as a channel layer.

The second display panel 111 is disposed on the first display panel 113 and includes a red, green, or blue color filter in a region corresponding to the pixel electrode so that colors can be displayed for each pixel. The color filter may be formed above or below the pixel electrode. In addition, a common electrode made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is formed on the color filter.

The liquid crystal layer (not shown) is interposed between the first display panel 113 and the second display panel 111 and has a dielectric anisotropy. The thickness of the liquid crystal layer is about 5㎛ and TN (Twisted Nematic) arrangement. In addition, the alignment direction is changed by a voltage applied from the outside to control the transmittance of light passing through the liquid crystal layer.

The driving IC 115 receives a gate control signal, a data control signal, a data signal related thereto, and the like from the printed circuit board 180 through an input terminal, and transmits the gate driving signal and the data driving signal to the first display panel through an output terminal. 113 is an integrated circuit for providing to the gate line and the data line formed on each. As a result, a desired image may be implemented on the liquid crystal panel 110. The driving IC 115 is mounted on the first display panel 113 other than the image display region formed by the bonding of the first display panel 113 and the second display panel 111, and the output terminal extends from the recall display region. It is mounted by a chip on glass (COG) method so as to be connected to the gate line and the data line, respectively. Accordingly, as described above, the gate driving signal and the data driving signal generated by the driving IC 115 are transmitted to each pixel formed in the image display area of the first display panel 113.

In addition, an input terminal of the driving IC 115 is connected to one end of the flexible printed circuit board 117, and the other end of the flexible printed circuit board 117 is connected to the printed circuit board 180. The printed circuit board 180 is mounted with a plurality of electronic components, and generates driving and control signals of the liquid crystal panel 110. The driving and control signals generated as described above are transferred to the driving IC 115 through the flexible printed circuit board 117 as described above. The printed circuit board 180 is bent along the sidewall of the lower receiving container 170 to be located at the rear of the lower receiving container 170.

In addition, the printed circuit board 180 is formed with a plurality of pads 181 to which the flexible circuit film 141 extending from the backlight assembly 130 may be attached. The printed circuit board 180 provides the light source driving signal to the backlight assembly 130 through the pad 181 and the flexible circuit film 141 attached to the pad 181.

The backlight assembly 130 is positioned below the liquid crystal panel 110 to supply light to the liquid crystal panel 110. The backlight assembly 130 includes the optical sheets 151, the light source unit 140, the light guide plate 152, the reflective sheet 153, and upper and lower storage containers 160 and 170 for storing them.

The light source unit 140 is positioned adjacent to one side of the light guide plate 152 and provides light to the liquid crystal panel 110. The light source unit 140 includes a light source 147 for generating light and a flexible circuit film 141 on which the light source 147 is mounted and supplies a voltage for driving the light source 147.

The light source 147 may include a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), and the like. The light source 147 using the light emitting diode will be described as an example.

In addition, a terminal portion 145 connected to the pad 181 of the printed circuit board 180 is formed at the end of the flexible circuit film 141. The terminal unit 145 may include a first terminal formed on one surface of the flexible circuit film 141 and a second terminal formed on the other surface opposite to one surface. In this case, the second terminal is in direct contact with the pad 181 of the printed circuit board 180, and the first terminal is in contact with the pad 181 of the printed circuit board 180 by soldering using solder. This flexible circuit film 141 will be described in detail later with reference to FIGS. 2 and 3.

The light guide plate 152 serves to guide the light emitted from the light source unit 140. The light guide plate 152 is formed of a pattern of a plastic-based transparent material such as acrylic to propagate light generated from the light source unit 140 toward the liquid crystal panel 110 seated on the light guide plate 152. Accordingly, various patterns for changing the traveling direction of light incident into the light guide plate 152 toward the liquid crystal panel 110 may be printed on the rear surface of the light guide plate 152.

The reflective sheet 153 is installed on the bottom surface of the light guide plate 152 to reflect light emitted to the bottom of the light guide plate 152 to the top of the light guide plate 152. The reflective sheet 153 is disposed on the lower surface of the light guide plate 152, and reflects light, which is not reflected by the minute dot pattern formed on the rear surface of the light guide plate 152, toward the exit surface of the light guide plate 152. While reducing the light loss of the light incident on the (110) and at the same time serves to improve the uniformity of the light transmitted to the exit surface of the light guide plate 152.

The optical sheets 151 are mounted on the upper surface of the light guide plate 152 to diffuse and collect light transmitted from the light guide plate 152. Such optical sheets 151 include a diffusion sheet, a prism sheet, a reflective polarizer sheet, and the like.

The liquid crystal panel assembly 120 is installed on the optical sheets 151 and is mounted on the light guide plate 152 together with the optical sheets 151.

The upper accommodating container 160 has sidewalls formed along edges of rectangular openings, and predetermined locking protrusions (not shown) are formed in the sidewalls to form the liquid crystal panel assembly 120, the optical sheets 151, and the light source unit ( 140, and serves to fix and accommodate the light guide plate 152 and the reflective sheet 153, and prevents the plurality of sheets from being bent. The liquid crystal panel 110, the optical sheets 151, the light source unit 140, the light guide plate 152, and the reflective sheet 153 may be accommodated in the upper storage container 160 according to a method of accommodating the upper storage container 160. The shape may be variously modified.

In addition, the upper container 160 may be hooked with the lower container 170, for example, the hook 165 is formed along the outer surface of the side wall of the upper container 160, the hook 165 And a hook insertion hole 175 corresponding to the lower storage container 170 may be formed on the side surface thereof. Therefore, the lower storage container 170 is lifted up and coupled from the bottom of the upper storage container 160, so that the hook 165 formed in the upper storage container 160 enters the hook insertion hole 175 of the lower storage container 170. The upper receiving container 160 and the lower receiving container 170 may be fastened. Here, the combination of the upper storage container 160 and the lower storage container 170 is not limited thereto, and the combination of the upper storage container 160 and the lower storage container 170 may be modified in various forms.

Hereinafter, a flexible circuit film according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 and 3.

FIG. 2 is an enlarged perspective view of the flexible circuit film used in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III ′ of FIG. 2.

2 and 3, the flexible circuit film 141 is formed by forming a conductor pattern on a film having flexibility and insulation, for example, a base film 142 having a polyimide material. The wiring pattern 143 constituting a predetermined circuit with a plurality of signal lines that can transmit the and a terminal portion 145 is formed at the end of the base film 142, and connected to the wiring pattern 143 Is done.

Here, the wiring pattern 143 is formed to a thickness of about 5 to 20 μm, and generally a metal material such as copper foil (Cu) is used, and preferably, plating of tin, gold, nickel or solder on the surface of the copper foil. Is carried out.

A method of forming copper foil, which is one example of such a wiring pattern 143, includes casting, laminating, electroplating, and the like. Here, casting is a method of thermal curing by spraying a liquid base film on a rolled copper foil, laminating is a method of placing a rolled copper foil on a base film and thermocompression bonding. In addition, electroplating is a method of forming a copper foil by depositing a copper seed layer on the base film and then putting the base film into an electrolyte in which copper is melted and flowing electricity. Here, the wiring patterned on the copper foil is formed to constitute a predetermined circuit by performing a photo / etching process on the copper foil and selectively etching the copper foil.

The insulating protective layer 144 is formed on the wiring pattern 143 formed to protect the wiring pattern 143 from external impact or corrosion. In this case, the insulating protection film 144 is not formed in the terminal portion 145, and thus the terminal portion 145 is exposed to the outside. Solder resist may be representatively used as the insulating protective film 144.

The terminal portion 145 formed at the end of the base film 142 is a portion for electrical connection with the outside. The terminal unit 145 includes a first terminal 145a formed on one surface of the base film 142 and a second terminal 145b formed on the other surface of the base film 142 opposite to one surface. The first and second terminals 145a and 145b may be formed of a conductive material, for example, the same material as the wiring pattern 143. In addition, the first terminal 145a and the second terminal 145b are electrically connected to each other by the via hole 146. In other words, a predetermined via hole 146 is formed from a predetermined portion of the first terminal 145a through the base film 142 to the second terminal 145b, and due to the via hole 146, the first terminal 145a is formed. And the second terminal 145b are electrically connected to each other. Here, the conductive material is formed in the via hole 146.

In addition, the first and second terminals 145b may be formed to have different lengths. This is to prevent the disconnection of the terminal portion 145 generated when the flexible circuit film 141 is bent to the rear side of the lower housing in combination with the printed circuit board. Here, the difference d between the lengths of the first terminal 145a and the second terminal 145b is preferably about 0.4 to 0.6 mm. In this case, the first terminal 145a may be longer than the second terminal 145b.

In addition, the second terminal 145b is in direct contact with the pad formed on the printed circuit board, and the first terminal 145a is soldered by solder to contact the pad of the printed circuit board so that the flexible circuit film 141 is printed circuit board. May be connected to the substrate. The terminal unit 145 including the first and second terminals 145a and 145b may be formed on one side or both sides of the base film 142, respectively.

In the present exemplary embodiment, the first terminal of the flexible circuit film is formed to be longer than the second terminal, but the present invention is not limited thereto, and the second terminal of the flexible circuit film may be formed longer than the first terminal. have.

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 circuit film, the backlight assembly including the same, and the liquid crystal display device including the same, the defect of the liquid crystal display device due to the disconnection of the flexible circuit film is changed by varying the length of the terminal portion of the flexible circuit film. It can be improved.

Claims (6)

Base film of insulating material; A first terminal formed on one surface of the base film, and a second terminal formed on the other surface of the base film opposite to the one surface, and electrically connected to the first terminal, and having a different length from the first terminal. A terminal unit; And A flexible circuit film formed on the base film, and comprising a wiring pattern connected to the terminal portion. According to claim 1, The length difference between the first terminal and the second terminal is approximately 0.4 ~ 0.6mm flexible circuit film. A base film of an insulating material, a first terminal formed on one surface of the base film, and a second length formed on the other surface of the base film opposite to the one surface and electrically connected to the first terminal, and different lengths from the first terminal. A flexible circuit film including a terminal portion including a second terminal formed of the second terminal and a wiring pattern formed on the base film and connected to the terminal portion; A light source mounted on the flexible circuit film and generating light; A printed circuit board generating a driving signal of the light source and having a pad connected to the flexible circuit film; A light guide plate positioned adjacent to one side of the light source and uniformly transmitting light transmitted from the light source; And And a storage container accommodating the flexible circuit film, the light source, and the light guide plate. The method of claim 3, wherein And a difference in length between the first terminal and the second terminal is approximately 0.4 to 0.6 mm. A base film of an insulating material, a first terminal formed on one surface of the base film, and a second length formed on the other surface of the base film opposite to the one surface and electrically connected to the first terminal, and different lengths from the first terminal. A flexible circuit film including a terminal portion including a second terminal formed of the second terminal, a wiring pattern formed on the base film and connected to the terminal portion, a light source mounted on the flexible circuit film, and generating light; A printed circuit board generating a driving signal of a light source and having a pad connected to the flexible circuit film, a light guide plate positioned adjacent to one side of the light source, and uniformly transferring light transmitted from the light source to the top; A backlight assembly including a flexible circuit film, a storage container for storing the light source and the light guide plate; And a liquid crystal panel positioned above the backlight assembly and configured to display an image by the light supplied from the backlight assembly. The method of claim 5, And a difference in length between the first terminal and the second terminal is approximately 0.4 to 0.6 mm.

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