KR20080014391A - Back light unit and liquid crystal display having the same - Google Patents

Abstract

A backlight unit and an LCD having the same are provided to connect connection terminals formed on facing lateral surfaces of neighboring power supply boards through an anisotropic conductive film, thereby facilitating electric connection of the power supply boards. A backlight unit comprises a plurality of power supply boards(200) and an anisotropic conductive film(500). At least one light emitting chip is mounted on each of the power supply boards. A plurality of connection terminals(216) are formed on each of lateral surfaces of the power supply board. The anisotropic conductive film is disposed between neighboring power supply boards to connect the connection terminals of the neighboring power supply boards electrically.

Description

BACK LIGHT UNIT AND LIQUID CRYSTAL DISPLAY HAVING THE SAME}

1 is an exploded perspective view illustrating a backlight unit according to an exemplary embodiment of the present invention.

FIG. 2 is a perspective view illustrating a portion of the power applying boards shown in FIG. 1.

3 is an enlarged perspective view illustrating a connection terminal portion of the power applying board shown in FIG. 2.

4 is a plan view of a portion of the backlight unit illustrated in FIG. 1 as viewed from above.

FIG. 5 is a cross-sectional view taken along the line II ′ of FIG. 3.

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

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

100: backlight unit 200: power supply board

214: power supply terminal 216: connection terminal

218: authorization line 300: light emitting chip

400: power supply 410: power line

500: anisotropic conductive film 510: binder

520: conductive particles 530: light diffusing particles

600: storage container 700: liquid crystal display panel

800 driving circuit portion 850 diffuser plate

860 optical sheet 900 liquid crystal display device

The present invention relates to a backlight unit and a liquid crystal display device having the same, and more particularly, to a backlight unit and a liquid crystal display device having the same that can simplify the electrical connection of the power supply boards.

In general, the liquid crystal display device includes a backlight unit for supplying light since the liquid crystal display panel for displaying an image cannot generate light by itself.

Liquid crystal displays generate light using various kinds of light emitting chips. In particular, the liquid crystal display device has recently used three light emitting chips that emit red light, green light, and blue light in order to improve color reproducibility in a large liquid crystal display device such as a TV.

These light emitting chips are supplied with a driving voltage from a power supply through separate power supply boards. In this case, the power supply boards are divided into a plurality of power supply boards in order to flexibly correspond to the large liquid crystal display, and use a method of electrically connecting the respective power supply boards. Specifically, the power applying boards are electrically connected to each other by forming connection terminals on the surface and screwing the wiring board thereto.

However, such electrical connection of the power supply boards has a problem that the operation is complicated by screwing the wiring board. In addition, since the connection terminal is formed on the surface of the power application board, the position where the light emitting chips are arranged is also limited.

Accordingly, the present invention has been made in view of such a problem, and the present invention provides a backlight unit and a liquid crystal display having the same, which can simplify the electrical connection of the power supply boards.

The backlight unit according to an aspect of the present invention includes a light emitting chip, power applying boards, and an anisotropic conductive film. At least one light emitting chip is disposed on the power applying boards, and a plurality of power supply boards are formed on each side thereof. The anisotropic conductive film is disposed between the power applying boards to electrically connect the connection terminals.

The anisotropic conductive film includes a binder having adhesion and conductive particles disposed in the binder and having conductivity. In addition, the anisotropic conductive film may further include light diffusing particles in the binder. The light diffusing particles may include polycarbonite.

Meanwhile, at least one of the power applying boards is formed with a power terminal to which driving power is applied from a power supply. In addition, a plurality of light emitting chips may be disposed in a grid form on the power applying boards.

According to an aspect of the present invention, a liquid crystal display device includes a backlight unit for supplying light and a liquid crystal display panel disposed on the backlight unit to display an image. The backlight unit may include a light emitting chip, at least one light emitting chip, and a plurality of power supply boards having connection terminals formed on respective side surfaces thereof, and disposed between the power supply boards to electrically connect the connection terminals. It includes an anisotropic conductive film.

According to such a backlight unit and a liquid crystal display having the same, by connecting connection terminals formed on opposite sides of the power applying boards to be electrically connected through a separate anisotropic conductive film, electrical connection of the power applying boards can be simplified. have.

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

1 is an exploded perspective view showing a backlight unit according to an embodiment of the present invention, FIG. 2 is a perspective view showing a part of the power applying boards shown in FIG. 1, and FIG. 3 is a connection of the power applying board shown in FIG. 4 is an enlarged perspective view of the terminal portion, and FIG. 4 is a plan view of a portion of the backlight unit illustrated in FIG.

1, 2, 3, and 4, the backlight unit 100 according to an embodiment of the present invention may include power supply boards 200, a light emitting chip 300, and a power supply 400. It includes.

The driving voltages are applied to the power applying boards 200 from the power supply unit 400. The power applying boards 200 have a plate shape in which the light emitting chips 300 generate light on the same plane. In addition, the power applying boards 200 are further provided with an application terminal 212 for applying a driving voltage to the light emitting chips (300).

A plurality of light emitting chips 300 are arranged in a lattice form along a first axis x and a second axis y perpendicular to the first axis x on the power applying boards 200. The light emitting chip 300 has a structure in which the first, second, and third light emitting chips 310, 320, and 330 that emit red light, green light, and blue light are collected one by one.

In detail, the light emitting chip 300 may have a triangular shape in which the first and third light emitting chips 310 and 330 are disposed at both ends of the bottom side with the second light emitting chip 320 as a vertex.

The light emitting chips 300 are alternately disposed above and below the first and third light emitting chips 310 and 330 corresponding to the bottom of the second light emitting chip 320 along the first axis x. That is, as the light emitting chips 300 move along the first axis x, only the position of the second light emitting chip 320 is changed.

In addition, the light emitting chips 300 may be disposed such that the first and third light emitting chips 310 and 330 alternate with each other about the second light emitting chip 320 along the second axis y. That is, as the light emitting chips 300 move along the second axis y, only the positions of the first and third light emitting chips 310 and 330 are changed.

The power supply unit 400 is electrically connected to the power applying boards 200 to supply the driving voltage. That is, the power supply unit 400 is electrically connected to the power terminal 214 formed on at least one of the power applying boards 200 of the power applying boards 200 including the power lines 410.

As a result, the driving voltage supplied from the power supply unit 400 is applied to the light emitting chip 300 through the power applying boards 200 so that the first, second and third light emitting chips 310, 320, and 330 emit light. do.

For example, the power supply unit 400 may be an inverter for converting the voltage input from the outside into the first, second, and third light emitting chips 310, 320, and 330, or may be the first, second, and third devices. The battery may generate a voltage suitable for the light emitting chips 310, 320, and 330.

On the other hand, a predetermined number of light emitting chips 300 are arranged on the power applying boards 200, and they form a plate shape. For example, nine light emitting chips 300 may be disposed on the power applying board 200.

As such, the idler which collects the power applying boards 200 into a single plate shape may increase the size of the liquid crystal display device on which the backlight unit 100 of the present invention is mounted. To reduce maintenance costs.

In other words, if the plate is not divided like the power applying boards 200, the operation is inconvenient as the size of the liquid crystal display device increases, and the sag failure rate increases, and even if the light emitting chip 300 is defective. This may be due to the need for replacement and maintenance.

The power applying boards 200 are electrically connected to each other to supply a driving voltage to all the light emitting chips 300. That is, connection terminals 216 are formed on side surfaces of the power applying boards 200 that face each other. The connection terminals 216 are electrically connected by the applying terminals 212 and the applying lines 218.

Here, the driving voltages for emitting the first, second, and third light emitting chips 310, 320, and 330 typically require pairs of connection terminals 216, as a positive electrode and a negative electrode are required. Accordingly, the power supply terminal 214 and the applying terminal 212 are also formed in pairs.

In addition, the connection terminals 216 serve to input and output a driving voltage in one power applying board 200. That is, a driving voltage is input from some of the connection terminals 216 to pass through the light emitting chips 300 and then output from other connection terminals 216.

The pair of connection terminals 216 are formed on one side of the power applying board 200. On the other hand, when it is determined that the connection terminal 216 has a large driving voltage, a plurality of pairs may be formed on the side surface.

In addition, the connection terminals 216 have a structure exposed to the outside of the power applying board 200 like the applying terminals 212. In contrast, the applying lines 218 have a structure that is electrically protected in the power applying board 200. That is, the power applying board 200 may include a protective layer covering the applying lines 218. Unlike this, the application line 218 may have a structure exposed to the outside of the power application board 200.

Thus, the light emitting chips 300 may form a connection terminal 216 on the side of the power applying boards 200 for electrical connection of the power applying boards 200, thereby preventing positional interference.

In addition, a separate anisotropic conductive film 500 for electrically connecting the connection terminals 216 is disposed on the side of the power applying board 200 while adhering the power applying board 200. Since the power applying board 200 has a thickness t of about 0.75 mm, the anisotropic conductive film 500 also preferably has a width w of about 0.75 mm. That is, the power supply board 200 and the anisotropic conductive film 500 has a very thin thickness (t) and a narrow width (w), respectively, for the worker to attach by hand.

Accordingly, the power applying boards 200 may use separate fixing jigs (not shown). Here, when the fixing jig does not match the parallel state of the power applying boards 200, the parallel state of the light emitting chips 300 may be poor, which may cause a problem in the direction of light travel and the thickness change of the power applying boards 200. Therefore, the horizontal state necessarily needs to be corrected.

Therefore, the power supply boards 200 are electrically connected through the anisotropic conductive film 500 by forming connection terminals 216 on the side surface, so that the electric connection of the power supply boards 200 may be more simply performed. have.

FIG. 5 is a cross-sectional view taken along the line II ′ of FIG. 3.

Referring to FIGS. 3 and 5, the anisotropic conductive film 500 is disposed in the binder 510 and the binder 510 having adhesiveness to electrically adhere each side of the power applying boards 200 to have conductivity. Conductive particles 520.

The binder 510 is partially melted by external heat and thus has adhesiveness. That is, heat is applied to the surface to be bonded or optionally, heat is applied to the anisotropic conductive film 500 to be partially melted and bonded, and then cooled to room temperature to be bonded. The binder 510 is made of, for example, a thermosetting resin.

The conductive particles 520 are irregularly distributed in the binder 510. The conductive particles 520 include metal balls coated with insulating elastic bodies on their surfaces. That is, the anisotropic conductive film 500 is broken at the connection terminal 216 to which the elastic body of the conductive particles 520 are to be electrically connected to conduct the connection terminals 216. The metal ball may include, for example, gold (Au).

Meanwhile, when the connection terminals 216 are formed on the side surfaces of the power applying boards 200 and bonded by the anisotropic conductive film 500, a distance of about 0.1 mm to about 0.9 mm is provided between the respective power applying boards 200. (d) is formed. This is substantially a small value, but since the liquid crystal display device on which the power supply boards 200 of the present invention are mounted is a very precise display device, the above-mentioned distance d may be visually recognized on the screen.

Accordingly, the anisotropic conductive film 500 may further include light diffusing particles 530 reflecting light generated from the light emitting chips 300 in the binder 510. The light diffusing particles 530 are literally made of a material having high light reflectance. For example, the light diffusing particles 530 may include polycarbonate (PC).

Alternatively, the light diffusing particles 530 may include silver (Ag) or aluminum (Al). Accordingly, the light diffusing particles 530 may also be made of a conductive metal material. That is, the light diffusion particles 530 may assist electrical connection of the connection terminals 216 serving as the conductive particles 520. In this case, the light diffusing particles 530 preferably have a diameter similar to that of the conductive particles 520.

On the other hand, if the distance between the connection terminals 216 is very short and a short circuit possibility is detected by the light diffusing particles 530, the diameter of the light diffusing particles 530 may affect the electrical connection of the connection terminals 216. It may be formed to be relatively smaller than the diameter of the conductive particles 520 to the extent that it does not extend.

On the other hand, the anisotropic conductive film 500 is formed of a metal ball, such as silver (Ag) or aluminum (Al) that can reflect light to the metal ball of the conductive particles 520, a transparent material that can transmit the elastic body light The conductive particles 520 themselves may be electrically connected to the connection terminals 216 and reflect light.

Accordingly, the anisotropic conductive film 500 further includes light diffusing particles 530 reflecting light generated from the light emitting chips 300 in addition to the conductive particles 520 for electrically connecting the connection terminals 216. Due to the separation distance d between the connection terminals 216 and the power applying boards 200 formed by the anisotropic conductive film 500, it is possible to prevent the dark portion from being generated on the screen.

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

In the present embodiment, since the backlight unit has the same structure as that shown in FIGS. 1, 2, 3, 4, and 5, the same reference numerals are used, and detailed description thereof will be omitted.

Referring to FIG. 6, the liquid crystal display device 900 according to an exemplary embodiment of the present invention includes a storage unit 600, a backlight unit 100 and a backlight unit 100 that are accommodated in the storage container 600 to supply light. And a liquid crystal display panel 700 disposed on the display to display an image.

The storage container 600 includes a bottom plate 610 and four sidewalls 620 extending vertically from an edge of the bottom plate 610. Meanwhile, the power supply unit 400 of the backlight unit 100 may be disposed on the rear surface of the storage container 600.

The liquid crystal display panel 700 includes a first substrate 710, a second substrate 720 coupled to face the first substrate 710, and a liquid crystal interposed between the first substrate 710 and the second substrate 720. Layer (not shown).

The first substrate 710 is a TFT substrate in which a thin film transistor (hereinafter, referred to as TFT), which is a switching element, is formed in a matrix form. The second substrate 720 is a color filter substrate in which RGB pixels for realizing color are formed in a thin film form.

In addition, the liquid crystal display device 900 further includes a driving circuit unit 800 for driving the liquid crystal display panel 700.

The driving circuit 800 includes a data printed circuit board 810 for supplying a data driving signal to the liquid crystal display panel 700, a gate printed circuit board 820 for supplying a gate driving signal to the liquid crystal display panel 700, and data printing. The data driving circuit film 830 connects the circuit board 810 to the liquid crystal display panel 700, and the gate driving circuit film 840 connects the gate printed circuit board 820 to the liquid crystal display panel 700. .

Meanwhile, the liquid crystal display device 900 is disposed between the backlight unit 100 and the liquid crystal display panel 700 to diffuse the light emitted from the light emitting chip 300 and the liquid crystal display panel 700. And an optical sheet 860 disposed between the diffuser plate 850 to improve characteristics of light emitted from the diffuser plate 850.

According to such a backlight unit and a liquid crystal display having the same, the power supply boards are electrically connected by forming connection terminals formed on opposite sides of the power supply boards and electrically connected thereto using an anisotropic conductive film. Can be.

In addition, the anisotropic conductive film further includes light diffusing particles that reflect light generated from the light emitting chips in addition to the conductive particles for electrically connecting the connection terminals, thereby providing a connection between the power supply boards formed by the connection terminals and the anisotropic conductive film. It is possible to prevent the dark portion from occurring on the screen due to the separation distance.

Although the detailed description of the present invention has been described with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art will have the idea of the present invention described in the claims to be described later. It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (7)

Light emitting chip; A plurality of power supply boards on which at least one light emitting chip is disposed, and connection terminals formed on respective side surfaces thereof; And And an anisotropic conductive film disposed between the power applying boards to electrically connect the connection terminals. The method of claim 1, wherein the anisotropic conductive film Binders having adhesive properties; And And a conductive particle disposed in the binder, the conductive particles having conductivity. The backlight unit of claim 2, wherein the anisotropic conductive film further comprises light diffusing particles in the binder. The backlight unit of claim 3, wherein the light diffusing particles comprise polycarbonite. The backlight unit of claim 3, wherein a power terminal to which driving power is applied is formed in at least one of the power applying boards. The backlight unit of claim 5, wherein a plurality of the light emitting chips are disposed in a grid shape on the power applying boards. A backlight unit for supplying light; A liquid crystal display panel disposed on the backlight unit to display an image; The backlight unit Light emitting chip, A plurality of power supply boards on which at least one light emitting chip is disposed, and connection terminals formed on respective side surfaces thereof; And an anisotropic conductive film disposed between the power applying boards to electrically connect the connection terminals.

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