KR101908502B1 - Liquid crystal display device - Google Patents

Abstract

The present invention eliminates a line on glass (LOG) line, directly contacts a flexible printed circuit board (FPCB) and a drive IC, prevents cracking of the FPCB, and reduces EMI (Electro Magnetic Interference) The present invention relates to a liquid crystal display device and a method of manufacturing the same. In the liquid crystal display device of the present invention, a first substrate and a second substrate are bonded to each other and a liquid crystal display panel; A drive IC connected to the pad portion; And a flexible printed circuit board directly connected to the drive IC and positioned below the drive IC to supply a signal to the drive IC, one side of which is attached to the first substrate.

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 removing a line on glass (LOG) line to prevent cracking of a flexible printed circuit board (FPCB) And a manufacturing method thereof.

The liquid crystal display device displays an image by adjusting the light transmittance of liquid crystal having dielectric anisotropy using an electric field. The liquid crystal display device includes a liquid crystal display panel in which a first substrate on which a thin film transistor is formed and a second substrate on which a color filter is formed are adhered to each other to form a plurality of pixel regions arranged in a matrix, And a driving circuit unit connected to the unit and the liquid crystal display panel to drive the liquid crystal display panel.

In the liquid crystal display panel, a plurality of pixel regions display images by adjusting the light transmittance of the backlight unit according to the pixel signals. The driving circuit includes a gate driver IC for driving the gate lines of the liquid crystal display panel, a data driver IC for driving the data lines, a timing controller for controlling the driving timing of the gate driver IC and the data driver IC, A power supply unit for supplying power supply signals necessary for driving the driving circuits, and the like.

At this time, the data driver IC and the gate driver IC are separated into a plurality of integrated circuits and fabricated in a chip form. A method of mounting the integrated drive IC on a liquid crystal display panel includes a TAB (Tape Automated Bonding) method in which a TAB (Tape Carrier Package) is mounted and connected to a liquid crystal display panel, a COG Glass) method.

The COG method is connected to a printed circuit board (PCB) through a flexible printed circuit (FPC) to provide a signal to the drive IC, and a timing control unit and a power supply An additional mounting is performed. In particular, recently, a timing control unit, a power supply unit, and the like are provided on a flexible printed circuit board (FPCB), so that the FPCB can be directly connected to the drive IC.

Hereinafter, a typical liquid crystal display device will be described in detail.

FIG. 1A is a plan view of a general liquid crystal display device, and FIG. 1B is a cross-sectional view of a general liquid crystal display device.

As shown in Figs. 1A and 1B, the liquid crystal display panel 10 and the backlight unit 31 are supported by the support main body 32. Specifically, the liquid crystal display panel 10 includes a first substrate 10a on which a thin film transistor (not shown) is formed and a second substrate 10b on which a color filter (not shown) is formed, And a liquid crystal layer (not shown) filled between the substrates. A thin film transistor (not shown) is formed on the first substrate 10a in a pixel region defined by vertically crossing the gate line GL and the data line DL, and is connected to one end of the gate line GL, One end of the line DL is connected to the gate pad and the data pad through the gate link line 11b and the data link line 11a, respectively, and the gate pad and the data pad are connected to the drive IC 20.

At this time, the drive IC 20 is connected to the FPCB 25 through the LOG line 21. The FPCB 25 is provided with a timing controller for providing various control signals for driving the liquid crystal display panel 10, and a power supply unit for providing a driving voltage. At this time, the FPCB 25 is folded so as to surround the lateral edge of the liquid crystal display panel 10 and fixed to the back surface of the support main body 32.

However, when the signal of the FPCB 25 is applied to the drive IC 20, since the signal transfer characteristic is applied through the LOG line 21 which is not good, the signal may be distorted by the resistance of the LOG line 21 . As a result, the quality of the image displayed on the liquid crystal display panel 10 is lowered, and EMI (Electro Magnetic Interference) occurs.

Cracks may occur in the FPCB 25 during the pressing process for bonding the drive IC 20, the FPCB 25, the gate pad (not shown), the data pad (not shown) have. Particularly, in a liquid crystal display device having a small liquid crystal display panel such as a mobile, since the FPCB 25 is folded so as to surround the side edge of the first substrate 10a, a risk of cracking is increased because the FPCB 25 performs a pressing process. Further, when the FPCB 25 is folded so as to surround the lateral edge of the liquid crystal display panel 10 so as to fix the FPCB 25 on the back surface of the liquid crystal display panel 10, the crack of the FPCB 25 can further proceed.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems and it is an object of the present invention to simplify the process and simplify the process by removing the LOG (Line On Glass) line and connecting the flexible printed circuit board (FPCB) The present invention provides a liquid crystal display device and a method of manufacturing the same that can improve noise caused by electro-magnetic interference.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a liquid crystal display panel including a first substrate and a second substrate facing each other and having a pad portion formed on the first substrate; A drive IC connected to the pad portion; And a flexible printed circuit board directly connected to the drive IC and positioned below the drive IC to supply a signal to the drive IC, the flexible printed circuit board having one side attached to the first substrate.

The flexible printed circuit board overlaps the input terminal of the drive IC.

The flexible printed circuit board is overlapped with an input terminal and an output terminal of the drive IC so as to be connected to the pad portion.

An area where the drive IC and the flexible printed circuit board are connected and an area where the first substrate and the flexible printed circuit board are connected overlap each other.

And the output terminal of the drive IC is connected to the flexible printed circuit board and the pad portion.

A timing control unit and a power supply unit are provided on the flexible printed circuit board.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including: preparing a liquid crystal display panel including a pad portion formed on a first substrate and a first substrate and a second substrate facing each other; Aligning a flexible printed circuit board on the first substrate; Aligning the drive IC on the flexible printed circuit board to directly connect the pad portion and the flexible printed circuit board; And pressing the drive IC so that the pad portion, the drive IC, and the flexible printed circuit board and the drive IC are electrically connected.

Further comprising forming a conductive contact resin between the first substrate and the flexible printed circuit board, between the pad portion and the drive IC, and between the flexible printed circuit board and the drive IC, and when pressing the drive IC, A conductive contact resin formed between the first substrate and the flexible printed circuit board, a conductive contact resin formed between the pad portion and the drive IC, and a conductive contact resin formed between the flexible printed circuit board and the drive IC are simultaneously pressed.

The liquid crystal display of the present invention and its manufacturing method as described above have the following effects.

First, by eliminating the line on glass (LOG) line, connecting the flexible printed circuit board (FPCB) and the drive IC directly, it is possible to improve the bonding strength and prevent cracking of the FPCB have. In particular, the FPCB has better signal transmission characteristics than the LOG line, and can reduce noise due to EMI (Electro Magnetic Interference).

Second, since the FPCB and the drive IC are bonded in the region where the FPCB and the first substrate are bonded, the compression process is simultaneously performed at the upper and lower portions based on the FPCB, and the bonding strength is improved.

1A is a plan view of a typical liquid crystal display device.
1B is a cross-sectional view of a typical liquid crystal display device.
2A is a plan view of a liquid crystal display device according to a first embodiment of the present invention.
2B is a cross-sectional view of a liquid crystal display device according to the first embodiment of the present invention.
2C is a cross-sectional view of the region A of FIG. 2B enlarged.
FIG. 3A is a plan view of a liquid crystal display device according to a second embodiment of the present invention. FIG.
3B is a sectional view of a liquid crystal display device according to a second embodiment of the present invention.
3C is a cross-sectional view of the region A of FIG. 3B enlarged.
4A to 4D are process sectional views showing a method of manufacturing the liquid crystal display device of the present invention.

Hereinafter, the liquid crystal display device of the present invention will be described in detail.

* First Embodiment *

FIG. 2A is a plan view of a liquid crystal display device according to a first embodiment of the present invention, and FIG. 2B is a sectional view of a liquid crystal display device according to a first embodiment of the present invention.

2A and 2B, a liquid crystal display according to a first embodiment of the present invention includes a liquid crystal display panel 100 including first and second substrates 100a and 100b opposed to each other, a liquid crystal display panel 100 A backlight unit 131 provided on the back surface of the liquid crystal display panel 100 to supply light to the liquid crystal display panel 100 and a driving circuit unit connected to the liquid crystal display panel 100 to drive the liquid crystal display panel 100. [ At this time, the liquid crystal display panel 100 and the backlight unit 131 are supported by the support main body 132, which is a double-sided tape or plastic fixing member.

Specifically, on the first substrate 100a, a gate line GL and a data line DL perpendicular to each other define a pixel region, and a thin film transistor is formed in the pixel region. The thin film transistor supplies a data voltage supplied from the data line DL to the pixel region in response to a scan signal provided from the gate line GL. A color filter is formed on the second substrate 100b which is adhered to the first substrate 100a and a liquid crystal layer (not shown) is formed between the first and second substrates 100a and 100b.

In the liquid crystal display panel 100 as described above, the light incident from the backlight unit 131 and passing through the liquid crystal layer (not shown) according to the arrangement of the liquid crystal molecules of the liquid crystal layer (not shown) Emits light to express an image.

One end of the gate line GL and the data line DL are connected to a gate pad (not shown), a data pad (not shown) formed at the edge of the first substrate 100a via the gate link line 111b and the data link line 111a, Respectively. And, the pad portion including the gate pad and the data pad is connected to the drive IC 120. Generally, the pad portion is formed at the edge of the first substrate exposed by the second substrate. The drive IC 120 is directly connected to a flexible printed circuit board (FPCB) 125.

The FPCB 125 is provided with a timing controller for providing various control signals for driving the liquid crystal display panel 100 and a power supply unit for supplying a driving voltage. At this time, the FPCB 125 is folded so as to surround the lateral edge of the liquid crystal display panel 100 and fixed to the back surface of the support main body 132.

However, as described above, since a signal applied to a drive IC connected to a pad unit is applied through a LOG (Line On Glass) line having poor signal transmission characteristics, a signal is distorted by a LOG line resistance . As a result, noise due to EMI (Electro Magnetic Interference) may be generated and the image quality of the liquid crystal display panel may be deteriorated. Also, during the pressing process, a crack of the FPCB occurs, and the signal can not be transmitted to the pad portion accurately. Particularly, in a liquid crystal display device having a small liquid crystal display panel such as a mobile, the FPCB is folded so as to surround the side edge of the first substrate, and then subjected to a pressing process.

Accordingly, in order to prevent cracking of the FPCB and improve signal transmission characteristics, the liquid crystal display according to the first embodiment of the present invention may be manufactured by removing the LOG line and extending the FPCB 125, 120 and the FPCB 125 are directly connected.

2C is a cross-sectional view of the area A of FIG. 2B enlarged.

2C, the FPCB 125 is positioned below the drive IC 120 and directly connected to the drive IC 120, and the drive IC 120 is connected to the pad portion PAD. The FPCB 125 includes a base film 125b and an input / output pad 125a formed on the base film 125b. The signal of the FPCB 125 is transferred to the drive IC 120 through the input / output pad 125a of the FPCB 125 and the transferred signal is transferred to the pad portion PAD.

One side of the input / output pad 125a of the FPCB 125 is connected to a timing controller and a power supply unit that provides a driving voltage and the other side is connected to the input terminal 120b of the drive IC 120 to form conductive contact resin 400 ). The pad portion PAD is also connected to the output terminal 120a of the drive IC 120 through the conductive contact resin 400. [ The signal of the FPCB 125 is transferred to the drive IC 120 through the input / output pad 125a of the FPCB 125 and the transferred signal is transferred to the pad portion PAD.

At this time, the conductive contact resin 400 is preferably an anisotropic conductive film (hereinafter referred to as ACF) including conductive balls. In addition, the FPCB 125 is also attached on the first substrate 100a through the conductive contact resin 400. Fig.

The LOG line is removed and the FPCB 125 and the drive IC 120 are directly connected to each other so that the FPCB 125 and the drive IC 120 are connected to each other The FPCB 125 and the first substrate 100a are connected to each other to perform a process of bonding the first substrate 100a and the FPCB 125 and a process of bonding the FPCB 125 and the drive IC 120 The process can be simplified.

Therefore, since the FPCB 125 and the drive IC 120 are bonded to each other in the region where the FPCB 125 and the first substrate 100a are bonded, the compression process occurs simultaneously at the upper and lower sides with respect to the FPCB 125, . In addition, the LOG line having poor signal transfer characteristics is removed, and the drive IC 120 and the FPCB 125 are directly connected to each other to improve the signal transfer characteristics. As a result, it is possible to reduce noise due to EMI (Electro Magnetic Interference).

* Second Embodiment *

FIG. 3A is a plan view of a liquid crystal display device according to a second embodiment of the present invention, and FIG. 3B is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention.

3A and 3B, a liquid crystal display device according to a second embodiment of the present invention includes a liquid crystal display panel 200 including first and second substrates 200a and 200b opposed to each other, a liquid crystal display panel A backlight unit 231 provided on a back surface of the liquid crystal display panel 200 to supply light to the liquid crystal display panel 200 and a driving circuit unit connected to the liquid crystal display panel 200 to drive the liquid crystal display panel 200. At this time, the liquid crystal display panel 200 and the backlight unit 231 are supported by the support main 232, which is a double-sided tape or plastic fixing member.

Specifically, a gate line GL and a data line DL, which are perpendicular to each other, define a pixel region on the first substrate 200a, a thin film transistor is formed in the pixel region, and the thin film transistor is provided from the gate line GL And supplies the data voltage supplied from the data line DL to the pixel region in response to the scan signal. A color filter is formed on the second substrate 200b, and a liquid crystal layer (not shown) is formed between the first and second substrates 200a and 200b. In the liquid crystal display panel 200, the light incident on the backlight unit 231 and passing through the liquid crystal layer (not shown) according to the arrangement of the liquid crystal molecules of the liquid crystal layer (not shown) Emits light to express an image.

One end of each of the gate line GL and the data line DL may be connected to the gate pad formed at the edge of the first substrate 200a through the gate link line 211b and the data link line 211a, And the pad portion including the gate pad and the data pad is connected to the drive IC 220. [ At this time, the drive IC 220 is directly connected to the FPCB 225.

The FPCB 225 is provided with a timing control unit for providing various control signals for driving the liquid crystal display panel 200 and a power supply unit for providing a driving voltage. At this time, the FPCB 225 is folded so as to surround the lateral edge of the liquid crystal display panel 200, and the FPCB 225 is fixed to the back surface of the support main 232.

Particularly, in the liquid crystal display according to the second embodiment of the present invention, the LOG line is removed and the FPCB 225 is extended from the first embodiment so that the drive IC 220 contacts the pad portion (not shown) The drive IC 220 and the FPCB 225 are directly connected. That is, the FPCB according to the first embodiment is spaced apart from the pad portion, but the FPCB 225 according to the second embodiment is extended to be connected to the pad portion.

3C is an enlarged cross-sectional view of the region A in FIG. 3B.

3C, the FPCB 225 is located below the drive IC 220 and is directly connected to the drive IC 220, and the drive IC 220 is connected to the pad portion PAD. The FPCB 225 includes a base film 225b and an input / output pad 225a formed on the base film 225b. Therefore, the signal of the FPCB 225 is transmitted to the drive IC 220 through the input / output pad 225a, and the transferred signal is transmitted to the pad portion PAD.

One side of the input / output pad 225a of the FPCB 225 is connected to a power supply unit or the like for providing a control voltage and a driving voltage while the other side is connected to the input terminal 220b of the drive IC 220, Lt; / RTI > The pad portion PAD is connected to the output terminal 220a of the drive IC 220 through the conductive contact resin 400 as well.

At this time, it is preferable that the conductive contact resin 400 is an ACF including conductive balls. The FPCB 225 is also attached to the first substrate 200a through the conductive contact resin 400. In the figure, the conductive contact resin 400 between the FPCB 225 and the first substrate 200a is separated However, the conductive contact resin 400 may be a structure to which the conductive contact resin 400 is connected.

Particularly, as described above, in the second embodiment of the present invention, the FPCB 225 is extended to be in contact with the pad portion PAD so that the FPCB 225 is overlapped with the output terminal 220a of the drive IC 220 . Therefore, it is preferable that the input / output pads 225a are separately formed to prevent the signal of the FPCB 225 from being directly transmitted to the pad portion PAD. Specifically, the input / output pad 225a is separated between the input terminal 220b and the output terminal 220a of the drive IC 220, and the input / output pad 225a connected to the pad portion PAD is separated from the dummy Pattern.

That is, the output terminal 220b of the drive IC 220 is connected to the pad portion PAD and the input / output pad 225a functioning as a dummy pattern through the conductive contact resin 400, The output pad 225a reduces the level difference between the pad portion PAD and the base film 225b of the FPCB 225 so that the conductive contact resin 400 and the pad portion PAD or between the conductive contact resin 400 And the output terminal 120a of the drive IC 120 can be prevented.

Hereinafter, a method for manufacturing a liquid crystal display device of the present invention will be described in detail.

4A to 4D are process cross-sectional views illustrating a method of manufacturing the liquid crystal display device of the present invention.

First, as shown in FIG. 4A, a first substrate 100a on which a pad portion (PAD), a thin film transistor (not shown), and the like are formed and a second substrate on which a color filter And the conductive contact resin 400 is coated on the first substrate 100a on which the pad portion PAD is formed. At this time, it is preferable that the conductive contact resin 400 is an ACF including conductive balls. The conductive contact resin 400 is for attaching the FPCB to be described later to the first substrate 100a. Next, as shown in FIG. 4B, the FPCB 125 is aligned on the first substrate 100a including the conductive contact resin 400. Next, as shown in FIG. At this time, the FPCB 125 includes a base film and an input / output pad 125a formed on the base film.

Then, as shown in FIG. 4C, the conductive contact resin 400 is applied on the pad portion PAD and the FPCB 125. 4D, after aligning the drive IC 120 on the FPCB 125 and the pad portion PAD, a high pressure is applied to the FPCB 125 and the first substrate 100a, the FPCB 125 The drive IC 120, the drive IC 120, and the pad portion PAD.

Specifically, the drive IC 120 includes an input terminal 120b and an output terminal 120a. The input terminal 120b is connected to the input / output pad 125a of the FPCB 125, and the output terminal 120a Is connected to the pad portion PAD. In particular, when the FPCB is extended to the pad portion so as to be directly connected to the pad portion as in the second embodiment (see FIG. 3C), the input / output pads of the FPCB are connected to the input / The input / output pads connected to the pad portion function as a dummy pattern.

That is, the output terminal of the drive IC is connected to the pad portion and the input / output pad functioning as a dummy pattern through the conductive contact resin so that the input / output pad functioning as the dummy pattern reduces the step of the base film of the pad portion and the FPCB It is possible to prevent a defect between the conductive contact resin and the pad portion or between the conductive contact resin and the output terminal of the drive IC during the pressing process.

Thereafter, an aging process for leaving the liquid crystal display device at a high temperature may be further performed. The aging process may be performed simultaneously with the pressing process.

As described above, the FPCB 125 and the first substrate 100a are also bonded by using a bonding process. In a typical liquid crystal display device, a process of bonding an FPCB and a substrate, a process of bonding an FPCB and a drive IC It can not be performed at the same time. This is because the FPCB is not directly connected to the drive IC but connected to the drive IC through the LOG, so that the region to be bonded is different.

However, since the LOG line of the present invention is removed and the FPCBs 125 and 225 and the drive ICs 120 and 220 are directly connected, the FPCBs 125 and 225 and the first substrate 100a The process of bonding the FPCBs 125 and 225 and the drive ICs 120 and 220 and the process of the drive ICs 120 and 220 and the pad portion PAD are simultaneously performed . Therefore, since the FPCBs 125 and 225 and the drive ICs 120 and 220 are bonded to the FPCBs 125 and 225 and the first substrate 100a and 200a, As a result, the bonding strength can be improved.

Also, as described above, the liquid crystal display of the present invention eliminates the LOG line having poor signal transmission characteristics, and the drive IC and the FPCB are directly connected to improve the signal transmission characteristic. As a result, it is possible to reduce noise due to EMI (Electro Magnetic Interference). In particular, the present invention is applicable not only to a liquid crystal display device but also to a flat panel display device having a pad portion.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

100, 200: liquid crystal display panels 100a, 200a: first substrate
100b, 200b: second substrate 111a, 211a: data link line
111b, 211b: gate link line 120, 220: drive IC
120a, 220a: output terminal 120b, 220b: input terminal
125, 225: FPCB 125a, 225a: input / output pad
125b, 225b: base film 131, 231: backlight unit
132, 232: Support main 400: Conductive contact resin

Claims (8)

A liquid crystal display panel including a first substrate and a second substrate facing each other and having a pad portion formed on the first substrate;
A backlight unit provided on a rear surface of the liquid crystal display panel to supply light to the liquid crystal display panel;
A support main body for supporting the liquid crystal display panel and the backlight unit;
A drive IC connected to the pad portion;
A flexible printed circuit board (PCB), which is located at a lower portion of the drive IC and is directly connected to the driver IC to supply a signal to the drive IC and is folded so as to surround a lateral edge of the liquid crystal display panel, Comprising a printed circuit board,
The flexible printed circuit board includes a base film and an input / output pad formed on the base film,
Wherein one end of the input and output pads of the flexible printed circuit board is connected to a timing control unit and a power supply unit formed on the flexible printed circuit board and the other end is connected to the input of the drive IC in a region where the flexible printed circuit board and the first substrate are bonded, Terminal and is connected via a conductive contact resin,
Wherein the pad portion is connected to the output terminal of the driver IC through the conductive contact resin, the flexible printed circuit board is attached onto the first substrate via the conductive contact resin,
The input and output pads of the flexible printed circuit board are separated from the input terminal and the output terminal of the driver IC and the input and output pads of the flexible printed circuit board connected to the pad portion function as dummy patterns . delete The method according to claim 1,
Wherein the flexible printed circuit board is overlapped with an input terminal and an output terminal of the drive IC so as to be connected to the pad portion. The method according to claim 1,
Wherein a region to which the drive IC and the flexible printed circuit board are connected and an area to which the flexible printed circuit board and the first substrate are connected overlap each other. The method of claim 3,
And an output terminal of the drive IC is connected to the flexible printed circuit board and the pad portion. delete delete delete

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