KR20170063019A - Liquid crystal display device - Google Patents

Abstract

The liquid crystal display device according to the present invention can be applied to an LED flexible circuit board connected to a backlight unit and an LCD flexible circuit board for connecting a main driver circuit to a structure in which a copper layer of a cross-sectional layer is formed. Accordingly, the material cost can be reduced as compared with the case where the copper layer of the double-sided layer is used. Accordingly, since the soldering can be performed by utilizing both sides of the LCD flexible circuit board, the number of processes is reduced, The thickness of the liquid crystal display device can be reduced.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of reducing the number of processes and reducing manufacturing cost by improving the bonding structure of a flexible circuit board connecting portion connecting a backlight unit and a main driving circuit.

As the era of informationization becomes full-scale, the display field for visually displaying electrical information signals is rapidly developing. Accordingly, studies are being continued to develop performance such as thinning, lightening, and low power consumption for various flat display devices.

Typical examples of such flat panel display devices include a liquid crystal display device (LCD), a plasma display panel (PDP), a field emission display (FED) An electro-luminescence display device (ELD), an electro-wetting display device (EWD), and an organic light emitting display device (OLED).

These flat panel display devices display an image using a unique light emitting material or a polarizing material interposed between a pair of substrates which are bonded to each other.

Further, the liquid crystal display device includes a liquid crystal panel that displays an image using the optical anisotropy and polarization properties of the liquid crystal. The liquid crystal panel includes a pair of substrates and a liquid crystal layer injected therebetween, and adjusts the light transmittance of each pixel region by adjusting the alignment direction of the liquid crystal. That is, the liquid crystal panel does not generate light by itself, but controls the amount of light emitted from the outside in each pixel region to display an image. Therefore, the liquid crystal display device includes a backlight unit that emits light to the liquid crystal panel.

Such a liquid crystal display device can be mounted as a component of another electronic device. That is, the liquid crystal display device is implemented as a device for displaying an image, or a device equipped with a user interface in various electronic devices such as navigation, notebook or household appliances.

FIG. 1 is a plan view showing a general liquid crystal display device, and FIG. 2 is a cross-sectional view taken along line A-A 'of the liquid crystal display device shown in FIG.

As shown in Fig. 1, the liquid crystal display includes a liquid crystal module, a backlight unit, and a connection unit for connecting the liquid crystal module and the backlight unit to each other with a flexible circuit board.

The liquid crystal module includes a plurality of liquid crystal panels that adjust the light transmittance of each pixel region by adjusting the arrangement direction of the liquid crystal, and the backlight unit includes a light source mounted in the bottom cover, an optical sheet, a light guide plate, .

The connecting portion is provided with an LED flexible circuit board connected to the backlight unit and a connection terminal for connecting the LCD flexible circuit board connected to the main driving circuit provided in the liquid crystal module.

However, since the flexible flexible printed circuit board has relatively few components mounted thereon compared to the flexible flexible printed circuit board, a copper layer is formed on both sides of the Flexible Flexible Circuit Board for bonding by soldering, There is a problem that the material cost of the material is increased.

In addition, in order to bond the LED flexible circuit board and the LCD flexible circuit board to each other, a drilling process must be further performed on the LED flexible circuit board, and a process of copper plating the inside of the drilled hole is additionally required, .

In addition, such a liquid crystal display device still has a limitation in that the overall thickness of the connection part can not be increased due to the copper plating process accompanying the LED flexible circuit board.

The present invention can be applied to a flexible printed circuit board connecting a backlight unit of a liquid crystal display device and a main drive circuit in a structure in which a copper cover layer is formed on a single surface of a flexible circuit board, The present invention provides a liquid crystal display device capable of reducing the number of process steps and reducing the thickness of a flexible circuit board by eliminating an additional plating process since solder bonding can be performed using both sides of the substrate.

According to an aspect of the present invention, there is provided a backlight unit comprising: a first connection part provided with a first connection terminal on an LED flexible circuit board connected to a backlight unit; and a second connection part provided with a second connection terminal on an LCD flexible circuit board connected to the main drive circuit The second connection terminal and the first connection terminal of the LCD flexible printed circuit board are disposed on the same plane as the junction surface of the light source so that the first connection terminal is disposed on the same plane as the plane on which the light source is disposed, .

Therefore, since the first connection terminal and the second connection terminal can be bonded by soldering on the same surface, the LED flexible printed circuit board can be used as a single layer of copper layer.

The surface of the LED flexible circuit board on which the light source is disposed and the surface on which the first connection terminal and the second connection terminal are soldered are arranged in the same manner.

Since the copper layer of the double layer of the LCD flexible circuit board is used when the first connecting portion and the second connecting portion are joined by soldering, a portion where the first connecting portion and the second connecting portion are overlapped, So that soldering bonding can be performed.

According to the liquid crystal display device according to the present invention,

First, since the LED flexible circuit board in which the light source is mounted in the backlight unit can be used as a single layer having only one connection terminal, the manufacturing cost can be reduced,

Second, in order to use the LED flexible circuit board as a double layer, a drilling process is added and a copper plating process is required. However, by providing a through hole or a cutting portion in the LCD flexible circuit board, the LED flexible circuit board and the LCD flexible circuit board It is possible to perform the joining process by overlapping and using soldering so that the joining process can be easily performed without any additional process,

Third, since the ELD flexible circuit board can be used as a single layer, the plating process is not required, and the effect of reducing the thickness of the LED flexible circuit board can be expected.

1 is a plan view showing a general liquid crystal display device.
2 is a cross-sectional view of the liquid crystal display device shown in FIG. 1, taken along the line AA '.
3 is a cross-sectional view illustrating a liquid crystal display device according to a first embodiment of the present invention.
Fig. 4 is a perspective view showing a state in which the first connecting portion and the second connecting portion of the liquid crystal display shown in Fig. 3 are connected. Fig.
5 is a cross-sectional view illustrating a liquid crystal display device according to a second embodiment of the present invention.
Fig. 6 is a perspective view showing a state in which the first connecting portion and the second connecting portion of the liquid crystal display shown in Fig. 5 are connected. Fig.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be noted that the drawings denoted by the same reference numerals in the drawings denote the same reference numerals whenever possible, in other drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. And certain features shown in the drawings are to be enlarged or reduced or simplified for ease of explanation, and the drawings and their components are not necessarily drawn to scale. However, those skilled in the art will readily understand these details.

FIG. 3 is a cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention, and FIG. 4 is a perspective view showing a state where a first connection part and a second connection part of the liquid crystal display device shown in FIG.

3 and 4, a liquid crystal display 100 according to a first embodiment of the present invention includes a liquid crystal panel 110, a backlight unit 120 that emits light toward the liquid crystal panel, A first connection part 130 connected to the unit 120 and provided with a first connection terminal 131 and a second connection part 130 connected to the main drive circuit and having a second connection terminal 141 and connected to the first connection part 130, 2 connection unit 140. [

The liquid crystal panel 110 includes an upper substrate 112 and a lower substrate 113. A liquid crystal layer (not shown) may be provided between the upper substrate 112 and the lower substrate 113, And an alignment layer (not shown) disposed on one side of the upper and lower surfaces of the liquid crystal panel 110 and for initially aligning the liquid crystal inside the liquid crystal layer may be provided, A polarizing layer (not shown) may be provided.

The liquid crystal panel 110 displays an image by selectively turning on and off the plurality of transistors to form an electric field for changing the arrangement direction of the liquid crystal in each pixel region, thereby adjusting the light transmittance of each pixel region.

Although not shown in the drawing, the liquid crystal display device 100 includes a liquid crystal panel 110, a bottom cover (not shown) for supporting the periphery of the backlight unit 120 disposed below the liquid crystal panel 110, A top cover (not shown), and a support main (not shown).

Here, the liquid crystal panel 110 and the backlight unit 120 are accommodated between the bottom cover and the top cover, which are fastened to each other, and the support main body supports the liquid crystal panel to prevent the liquid crystal panel from flowing.

The liquid crystal panel 110 is bonded to the upper substrate 112 and the lower substrate 113 so as to face each other, and a liquid crystal layer may be disposed therebetween.

3, when the liquid crystal panel 110 is driven in an active matrix manner, the liquid crystal panel 110 may include any one of the upper substrate 112 and the lower substrate 113 (for example, the lower substrate 113). And may further include a plurality of thin film transistors (TFTs) 114 corresponding to a plurality of pixel regions. When the liquid crystal panel 110 displays a color image, the liquid crystal panel 110 further includes a color filter layer 115 for filtering hues corresponding to the respective pixel regions.

The backlight unit 120 is disposed on the lower side of the liquid crystal panel 110 and emits light toward the liquid crystal panel 110 side.

For example, the backlight unit 120 includes a plurality of light sources 122 for emitting light, an LED flexible printed circuit board (LED FPCB) 121 on which the plurality of light sources 122 are mounted, A plurality of optical sheets 124 disposed between the light guide plate 123 and the liquid crystal panel 110 and a plurality of reflection sheets disposed under the light guide plate 123, And a sheet (Reflector) 125.

Each of the plurality of light sources 122 may be an LED (Light Emitting Diode) emitting white light.

The light source 122 is mounted on one end of the LED flexible circuit board 121 disposed inside the backlight unit 120 and the first connection unit 130 is connected to the other end extending to the outside.

A first connection terminal 131 electrically connected to the first connection unit 130 is formed on a surface of the flexible printed circuit board 121 on which the first connection terminal 131 is formed, Is formed on the same surface.

Accordingly, since the light source is soldered to one surface of the LED flexible circuit board 121 and the first connection terminal 131 is soldered to the same surface as the surface of the light source 122, It can be applied as a copper layer. Therefore, it is generally effective to reduce the material cost as compared with the use of a double layer copper layer.

Of course, the LED flexible circuit board 121 has been used as a double-sided layer for soldering bonding, and if the problem of soldering bonding is solved because the number of components to be mounted is smaller than that of an LCD flexible printed circuit board (LCD FPCB) It is possible to apply the copper layer of FIG.

In addition, the use of the flexible printed circuit board 121 as a single surface reduces the material cost as well as the thickness of the copper layer. Further, when the double-sided layer is used, the problem of involving the drilling process and the copper plating process The effect that can be solved is expected. In addition, a copper plating process is not required, and the thickness of the LED flexible circuit board 121 is also reduced.

The LCD drive circuit board 111 is provided with a main driving circuit for supplying power or control signals to the liquid crystal panel 110 or the backlight unit 120. A second connection part 140 are provided.

At this time, the second connection terminal 140 is provided with a second connection terminal 141, and the second connection terminal 141 is connected to the first connection terminal 131 by soldering.

3 and 4, the first connection part 130 and the second connection part 140 are joined to each other to electrically connect the LED flexible circuit board 131 and the LCD flexible circuit board 121. [

The first connection terminal 131 is located at a lower position and the second connection terminal 141 is located at an upper position and are connected to the first connection part 130 of the LED flexible circuit board 121, The second connecting portions 140 of the circuit board 111 are arranged so as to overlap with each other. That is, the second connection terminal 141 connected to the first connection part 130 is positioned so as to correspond to the soldering position of the first connection terminal 131 for the soldering process. In order to bond the first connection part 130 and the second connection part 140 together with the soldering process of the light source 122 of the LED flexible circuit board 121, The terminal 141 is also located on the same plane as the surface on which the light source 122 is soldered.

The upper surface of the first connection terminal 131 is partially exposed when the first connection part 130 and the second connection part 140 are partially overlapped and the upper surface of the second connection terminal 141 is entirely exposed Respectively. The second connection terminal 141 is a part of the second connection part 140 and the second connection part 140 is a component provided in a part of the LCD flexible circuit board 111, The second connection terminal 141 is disposed adjacent to the peripheral edge of the LCD flexible printed circuit board 111 and the cutting part 142 is formed on the remaining LCD flexible printed circuit board 111 at the peripheral part, .

The cutting portion 142 corresponds to a portion of the LCD flexible printed circuit board 111 that is cut around the second connection terminal 141. When a part of the periphery of the second connection terminal 141 can be cut The cutting portion 142 can be applied. Alternatively, the second connection terminal 141 may be positioned at one end of the LCD flexible circuit board 111 so that the cutting unit 142 is not provided separately.

The solder paste or the solder cream is applied to the light source 122 and is coated on the first connection terminal 131 and the second connection terminal 141 so that soldering bonding can be performed on the same surface in one process have.

FIG. 5 is a cross-sectional view illustrating a liquid crystal display device according to a second embodiment of the present invention, and FIG. 6 is a perspective view illustrating a state in which a first connecting portion and a second connecting portion of the liquid crystal display device shown in FIG.

Referring to FIGS. 5 and 6, the liquid crystal display device 200 according to the second embodiment of the present invention is different in the junction structure of the first connection part 130 and the second connection part 140.

The first connection part 130 connected to the flexible printed circuit board 121 has the same structure and the second connection part 140 connected to the flexible printed circuit board 111 is connected to the edge of the flexible printed circuit board 111 Respectively. In other words, unlike the first embodiment, which is located around the edge of the LCD flexible printed circuit board, it is located far from the center or the edge of the LCD flexible circuit board 111.

The second connection terminal 141 provided in the second connection part 140 must be soldered to the first connection terminal 131 disposed at the lower side so that the through hole 243 is formed around the second connection terminal 141, Respectively.

The through hole 243 is formed by punching a part of the LCD flexible circuit board 111 and provides a function of exposing the first connection part 130 from the lower side of the second connection part 140 through the through hole 243 do.

When the first connection part 130 and the second connection part 140 are soldered to each other, the first connection terminal 131 is positioned below the second connection terminal 141 and the first connection terminal 131 is connected to the first connection terminal 131 through the through- The first connection part 130 and the second connection part 140 are soldered to each other by matching the joint part with the second connection terminal 141 on the same surface while the terminal 131 is exposed.

The bonding surface of the light source provided on the flexible printed circuit board 121 and the bonding surfaces of the first connection unit 130 and the second connection unit 140 are provided on the same surface as before, The bonding process of the first connection part 130 and the second connection part 140 can be performed simultaneously with the process.

The first connection part 130 can be used as a single layer by modifying the shape or the structure of the second connection part 140 so that the material cost of the LED flexible circuit board 121 is reduced, Or the thickness of the LED flexible circuit board 121 can be reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken in conjunction with the present invention. But can be carried out within a range that does not deviate. Accordingly, such modifications are also considered to be within the scope of the present invention, and the true scope of protection of the present invention should be determined by the technical idea of the following claims.

100, 200: liquid crystal display
111: LCD flexible circuit board 112: upper substrate
113: lower substrate 114: thin film transistor
115: Color filter 120: Backlight unit
121: LED flexible circuit board 122: light source
123: light guide plate 124: optical sheet
125: reflective sheet 130: first connection
131: first connection terminal 140: second connection part
141: second connection terminal 142:
243: Through hole

Claims (4)

A liquid crystal panel;
A backlight unit disposed below the liquid crystal panel and irradiating light toward the liquid crystal panel through a plurality of light sources provided therein;
A first connection part extending from the LED flexible circuit board mounted on one surface of the backlight unit and having a first connection terminal on the same surface as the first surface,
And a second connection terminal connected to the main driving circuit for supplying a power or a control signal to the liquid crystal panel or the backlight unit and extending from the LCD flexible circuit board connected to the main driving circuit, And a connection portion. The method according to claim 1,
Wherein the flexible flexible printed circuit board comprises a single layer as a connection terminal and the flexible flexible printed circuit board is provided as at least a double layer. The method according to claim 1,
And the second connection portion is provided with a through hole around the second connection terminal so that the first connection terminal is disposed so as to overlap the first connection terminal below the second connection terminal. The method according to claim 1,
And the second connection portion includes a cutting portion that cuts the periphery of the second connection terminal so that the first connection terminal is disposed so as to overlap the first connection terminal below the second connection terminal.

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