KR101730847B1

KR101730847B1 - chip on film and liquid crystal display device module including the same

Info

Publication number: KR101730847B1
Application number: KR1020100114069A
Authority: KR
Inventors: 조재형; 박승철
Original assignee: 엘지디스플레이 주식회사
Priority date: 2010-11-16
Filing date: 2010-11-16
Publication date: 2017-04-27
Also published as: KR20120052764A

Abstract

The present invention relates to a liquid crystal display device, comprising: a liquid crystal panel; A COF connected to the liquid crystal panel, on which a source driver IC having a long side and a short side is mounted; And a printed circuit board connected to the COF and having a connector and a resistor and a capacitor mounted thereon, wherein the source driver IC is mounted on the COF perpendicularly to the longitudinal direction of the long side.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a chip-on film and a liquid crystal display device including the chip-

The present invention relates to a COF for a liquid crystal display and a liquid crystal display using the same.

2. Description of the Related Art [0002] With the development of an information society, demands for a display device for displaying images have been increasing in various forms. Recently, a liquid crystal display (LCD), a plasma display panel (PDP) Various flat display devices such as an organic light emitting diode (OLED) have been utilized.

Of these flat panel display devices, liquid crystal display devices are widely used today because they have advantages of miniaturization, weight reduction, thinness, and low power driving.

In recent years, various products using the concept of an e-skin in which a display part covers the entire or a part of the entire surface of an electronic product are being released. For this purpose, studies have been actively made on a curved display with ductility so that the liquid crystal panel can be bent in various forms. Accordingly, in the semiconductor package field used for the flexible display, a new mounting method Semiconductor packages are emerging.

Conventionally, a micro-ball grid array (μ-BGA) type semiconductor package has been mainly used for a liquid crystal display device. At this time, the microvision AG is not ductile and can only be formed in a flat shape.

There are the following problems when using this in a soft display device (hereinafter, the problem will be described with reference to Fig. 1).

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view of a general liquid crystal display device 10; As shown in FIG. 1, the liquid crystal panel 20 is in a state in which the first substrate 21 and the second substrate 22 are bonded to each other with a liquid crystal layer (not shown) therebetween.

The first substrate 21 of the liquid crystal panel 20 has a plurality of data pads and gate pads at two edges, respectively, though not clearly shown in the drawing. The plurality of data pads and the gate pads are connected to the external printed circuit board 40 via the COF 30, respectively.

A timing controller, a power supply, a gamma voltage generator, and the like are mounted on the printed circuit board 40 for generating signal voltages necessary for image display by primarily processing various signal information input from external devices such as a computer. To this end, a connector 41 for receiving and transmitting signal information and a plurality of resistors and a capacitance 42 are mounted on the printed circuit board 40.

A gate driver IC (not shown) and a source driver IC 31 are mounted on the COF 30.

At this time, as shown in FIG. 1, the connector 41, the plurality of resistors and the capacitance 42, and the source driver IC 31 are arranged in the lateral direction.

However, as shown in Fig. 2, in the case of the flexible display, as the printed circuit board 40 and the COF 30 are warped, a large number of parts mounted on these films are wrinkled, wiring is broken, . That is, components that can not withstand the curvature are separated, resulting in defective products and signals, which may degrade the image quality of the liquid crystal display.

According to the present invention, the arrangement of the components of the COF and the printed circuit board used in the soft display is positioned in the normal direction of the curvature, thereby preventing component departure.

In addition, since the printed circuit board and the COF component are stably maintained, the electrical signal can be stably supplied.

In order to achieve the above-described object, the present invention provides a liquid crystal display comprising: a liquid crystal panel; A COF connected to the liquid crystal panel, on which a source driver IC having a long side and a short side is mounted; And a printed circuit board connected to the COF and having a connector and a resistor and a capacitor mounted thereon, wherein the source driver IC is mounted on the COF perpendicularly to the longitudinal direction of the long side.

Wherein the COF includes an input / output wiring pattern including a chip input region in which a chip mounting region in which the source driver IC is mounted is defined and formed around an edge of the chip mounting region, It is turned toward the long side of the IC.

The COF uses polyimide.

The printed circuit board uses an FPC having a thickness of 0.5 t or less.

And the long side of the connector and the resistance and the capacitance are mounted on the printed circuit board perpendicularly to the longitudinal line direction.

A source driver IC comprising a long side and a short side; And an input / output wiring pattern including a chip input region in which a source driver IC is mounted, the chip input region being defined around an edge of the chip mounting region, To provide a chip-on film that tilts toward the surface.

The liquid crystal display device according to the present invention provides a liquid crystal display device suitable for a soft display, and accordingly, an electric signal can be stably supplied through prevention of departure of a source driver IC or the like.

FIG. 1 schematically shows a conventional liquid crystal display. FIG.
FIG. 2 is a photograph showing deviation and warpage of a component of a COF and a printed circuit board in a conventional liquid crystal display device. FIG.
3 is a view schematically showing a liquid crystal display device according to an embodiment of the present invention.
4 is a partial perspective view of a liquid crystal panel according to an embodiment of the present invention.
5 is a photograph showing a printed circuit board used in an embodiment of the present invention.
6 illustrates an arrangement of source driver ICs in a COF according to an embodiment of the present invention.
7 is a view showing the arrangement of a source driver IC in a conventional COF.
8 is a view showing a wiring pattern of a COF according to an embodiment of the present invention.
9 is a view showing a wiring pattern of a conventional COF.

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

4 is a partially exploded perspective view of a liquid crystal panel according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view illustrating a liquid crystal display according to an embodiment of the present invention. Referring to FIG. 3, A photograph of a circuit board.

As shown in the drawing, the liquid crystal panel 200 including the first and second substrates 210 and 220 which are bonded together with the liquid crystal layer (not shown) interposed therebetween, and a plurality of COFs A printed circuit board 400 connected to one edge of the liquid crystal panel 200 via a light source 300 and a backlight (not shown) for supplying light from the back surface of the liquid crystal panel 200.

Here, these will be specifically described.

4, a plurality of data lines 212 and a plurality of gate lines (not shown) are formed on one surface of a first substrate 210 called a lower substrate or an array substrate, 216 define a pixel P in a crosswise direction. A thin film transistor T is provided at the intersection of these two lines and connected in a one-to-one correspondence with the transparent pixel electrode 211 provided in each pixel region P.

The second substrate 220 facing the first substrate 210 with the liquid crystal layer 225 therebetween is called an upper substrate or a color filter substrate. Shaped black matrix 232 covering the pixel region P so as to expose only the pixel electrode 211 while covering the non-display elements such as the gate line 216, the thin film transistor T and the like.

Green, and blue color filters 234a, 234b, and 234c, which are sequentially and repeatedly arranged in correspondence to the respective pixel regions P within these lattices, And a transparent common electrode 236.

Although not clearly shown in the drawings, the upper and lower alignment films for determining the initial alignment direction of the liquid crystal are interposed at the boundaries between the first and second substrates 210 and 220 and the liquid crystal layer 225, A seal pattern is formed along the edges of the first and second substrates 210 and 220 to prevent leakage of the liquid crystal layer 225 filled therebetween and the first and second substrates 210 and 220 ) May be attached to the outer surface of the polarizing plate for selectively transmitting only the specific light.

The first substrate 210 has a larger size than the second substrate 220. At least one side edge of the first substrate 210 is exposed to the outside when the first substrate 210 and the second substrate 220 are attached to each other. A plurality of data pads 214 connected to the plurality of data lines 212 and a plurality of gate pads (not shown) connected to the plurality of gate lines 216 are located.

The plurality of data pads 214 and the gate pads (not shown) are connected to the external printed circuit board 400 through the COF 300.

Here, the printed circuit board 400 is mounted with a timing controller, a power supply, a gamma voltage generator, and the like, which primarily processes various signal information input from an external device such as a computer to generate a signal voltage necessary for image display.

To this end, although not shown in the printed circuit board 400, a connector for receiving and transmitting signal information, and a plurality of resistances and capacitances are mounted.

As the printed circuit board 400, for example, a flexible print circuit (FPC) can be used. The FPC is characterized in that, for example, a pitch for forming a copper wiring pattern is somewhat smaller than that of a flexible film package, but can be bent and a through hole can be formed therein. The flexible film package will be described later in more detail.

This is because the degree of miniaturization of the copper wiring pattern connected to the COF 300 from the printed circuit board 400 is smaller than that of the copper wiring pattern connected from the COF 300 to the liquid crystal panel 200, And can be used as the printed circuit board 400.

Accordingly, even if the thermal expansion coefficient and durability of the printed circuit board 400 are lowered rather than a flexible film package such as polyimide, which is expensive, the FPC is used because the cost is low and the reliability is not problematic. Can be lowered.

In addition, when a flexible FPC is used, as shown in Fig. 5, the printed circuit board 400 can be flexible and bent in various forms.

Here, the printed circuit board 400 may have a thickness of, for example, 0.5 t or less so as to have greater ductility. The conventional printed circuit board had a thickness of 0.8 t or more, and thus it was limited to have greater ductility. Therefore, in the embodiment of the present invention, by making the thickness of the printed circuit board 400 less than 0.5t, the flexibility of the printed circuit board 400 is increased, and thus it can be more suitably used for the flexible display product. Here, t is a unit representing the thickness of the printed circuit board 400, and 1 t is 1000 m.

The COF 300 is mounted with a source driver IC 310 for generating and outputting an image signal transmitted to the data line 212 of the liquid crystal panel 200 through a signal voltage transmitted from the printed circuit board 400 .

The source driver IC 310 is mounted on the tape wiring substrate by a flip chip bonding method and the both ends of the COF 300 are connected to the anisotropic conductive film ACF And are attached to the liquid crystal panel 200 and the printed circuit board 400, respectively.

Although not shown, a gate driver IC, which is transmitted to the gate line 216 and generates and outputs a scan signal including an on / off signal for the thin film transistor T, is mounted on the COF 300, .

Accordingly, when the selected thin film transistor T for each gate line 216 is turned on by the ON / OFF signals of the thin film transistor T which has been transferred to the gate line 216, the liquid crystal panel 200 is turned on And the alignment direction of the liquid crystal molecules is changed by the electric field between the pixel electrode 211 and the common electrode 236 which is generated due to the change in the transmissivity.

At this time, the source driver IC 310 and the gate driver IC (not shown) may each include a semiconductor device packaged in a chip form.

As the COF 300, for example, a flexible film package may be used.

The flexible film package is a semiconductor package having a shape that can be bent so as to drive a semiconductor chip directly mounted on a thin tape-shaped film and to reduce a mounting area.

In such a flexible film package, for example, a copper wiring formed on the film is directly attached to the COF 300 with an anisotropic conductive adhesive (ACF: anti-isoprotropic conductive film). Here, the flexible film package can use polyimide, which is a material having excellent coefficient of thermal expansion (CTE) and durability. It is also known to those skilled in the art that synthetic resins such as acrylic, polyether nitrile, polyether sulfone, polyethylene terephthalate, and polyethylene naphthalate may be used It is obvious.

That is, by configuring the COF 300 as a flexible film package, an electric signal can be stably transmitted, and the COF 300 can be more ductile and can be used more efficiently in a flexible display product.

Hereinafter, the COF 300 according to the embodiment of the present invention will be described in more detail with reference to FIG.

6 is a view showing a mounting form of the source driver IC 310 in the COF 300 according to the embodiment of the present invention.

First, as shown in FIG. 6, the source driver IC 310 according to the embodiment of the present invention is arranged in the COF 300 such that the long side of the source driver IC 310 is perpendicular to the longitudinal direction.

In the embodiment of the present invention, the printed circuit board 400 and the COF 300 are mounted on the printed circuit board 400 and the COF 300 for more efficient use in the flexible display, as described above. Can be bent into various shapes with ductility. For this purpose, for example, a flexible film package is used as the printed circuit board 400 and the COF 300.

As shown, the liquid crystal panel 200, the COF 300, and the printed circuit board 400 have a curvature. That is, it forms a curved surface.

Here, for convenience of explanation, the center direction of the curved surface is defined as the curvature direction (CD). A part of the curved line is defined as a tangential direction TD and a direction perpendicular to both the curvature direction CD and the tangential direction TD is defined as a normal direction PD.

Further, the source driver IC 310 may be configured with, for example, a long side and a short side.

At this time, the source driver IC 310 is configured in the COF 300 such that the long sides of the source driver IC 310 are directed in the normal direction PD of the curvature direction CD. Thus, as shown in Fig. 6, the source driver IC 310 is arranged in the COF 300 vertically in the longitudinal direction, for example.

Conventionally, as shown in Fig. 7, the long side of the source driver IC is positioned in the tangential direction (TD). That is, the long side of the source driver IC is arranged in the COF in the lateral direction. When the source driver IC thus formed is applied to the soft display, there is a problem that the source driver IC can not withstand the curvature as the COF is warped.

However, in the case of the present invention, the long side of the source driver IC 310 is configured in the COF 300 in the normal direction PD of the curvature direction CD, and is designed to minimize the resistance of the curvature. Accordingly, even if the COF 300 has a curvature, the COF 300 is stably maintained in the COF 300, and the signal failure is also reduced.

Although not shown, like the source driver IC 310, a connector for receiving and transmitting signal information, for example, mounted on the printed circuit board 400, and a plurality of resistors and capacitances, May be mounted on the printed circuit board 400 so as to face the normal direction PD of the direction CD.

That is, the connector and a plurality of resistors and capacitances are disposed on the printed circuit board 400 in the vertical direction.

As a result, the elements mounted on the printed circuit board 400 receive the minimum resistance of ductility, so that they are stably maintained, thereby reducing signal defects.

8 is a view showing a wiring pattern of the COF 300 according to the embodiment of the present invention.

First, as described above, the source driver IC 310 is flip-chip bonded to the upper surface of the tape wiring substrate 320 via an electrode bump (not shown), and the bonded portion is connected to the source driver IC 310 (Not shown) filled between the wiring substrate 320 and the tape wiring substrate 320.

The tape wiring substrate 320 may include an input wiring pattern 322a and an output wiring pattern 322b formed by patterning the upper metal layer and the base film 321 have.

The base film 321 is provided with a chip mounting area A in which a source driver IC 310 is mounted at a central portion of the base film 321. Sprocket holes 323 are formed.

At this time, the chip mounting area A is preferably formed in a direction parallel to the direction in which the sprocket holes 323 are arranged.

This is because, as described above, in the embodiment of the present invention, the long side of the source driver IC 310 is mounted on the COF 300 so as to be positioned along the normal direction PD of the curvature direction CD. Specifically, conventionally, when the source driver IC is mounted on the COF, the long side of the source driver IC is positioned along the tangential direction (TD) of the transverse direction, that is, the curvature direction (CD) There is a problem that the driver IC deviates. That is, in order to solve this problem, in the present invention, the source driver IC 310 is vertically mounted on the COF 300, for example, as described above.

Here, as the base film 321, an insulating synthetic resin may be used. Specifically, for example, polyimide may be used as a flexible film package. It is apparent to those skilled in the art that synthetic resins such as acrylic, polyether nitrile, polyethersulfone, polyethylene terephthalate, polyethylene naphthalate, and polyvinyl chloride can be used.

The input / output wiring patterns 322a and 322b are preferably formed by attaching a copper foil as a metal layer to the upper surface of the base film 321 and then patterning the copper foil by a photolithography process. Nickel (Ni), gold (Au), solder or an alloy of these materials, which have electrical conductivity, as well as the like.

The input / output wiring patterns 322a and 322b are flip-chip bonded at one end via electrode bumps, and the other ends connected to the ends extend out of the chip mounting area A, though not shown in the figure. At this time, one end of the input / output wiring patterns 322a and 322b is formed around the edge of the chip mounting area A so that the electrode bumps can be bonded.

The other end of the input wiring pattern 322a extends to one side of the base film 321 with the source driver IC 310 as a center and the other end of the output wiring pattern 322b extends to the other side of the base film 321 .

More specifically, the other ends of the input wiring patterns 322a are bonded to the printed circuit board 400 (FIG. 6), and the other ends of the output wiring patterns 322b are bonded to the liquid crystal panel 200 (FIG. At this time, both ends of the COF 300 are attached to the liquid crystal panel 200 and the printed circuit board 400 via an anisotropic conductive film (ACF), which is a conductive adhesive material.

One end of the one end of the input / output wiring patterns 322a and 322b according to the embodiment of the present invention, that is, one end formed around the periphery of the chip mounting area A will be described in more detail. Here, for convenience of explanation, one end formed around the periphery of the chip mounting area A of the input / output wiring patterns 322a and 322b is referred to as a chip inputting portion B.

First, as described above, as shown in FIG. 8, the source driver IC 310 is disposed in the COF 300 vertically in the longitudinal direction, for example.

As a result, the chip input portion B of the input / output wiring patterns 322a and 322b is turned toward the long axis of the chip mounting area A. That is, the chip input section B is turned toward the long side of the source driver IC 310.

More specifically, as the source driver IC 310 is vertically mounted on the COF 300, the chip input portion B of the input / output wiring patterns 322a and 322b is formed in parallel with the sprocket holes 323 And is bent toward the chip mounting area A with increasing distance from the sprocket holes 323.

Conventionally, as shown in Fig. 9, the input / output wiring pattern is configured parallel to the sprocket holes. In the conventional configuration, the source driver IC is formed in a horizontal direction not suitable for the soft display, so that the input / output wiring pattern can be formed parallel to the sprocket holes.

However, in the present invention, the source driver IC 310 is formed in the vertical direction, for example, in the COF 300, and the formation of such a vertical direction causes the input / output wiring patterns 322a and 322b to be formed in the sprocket holes 323 It is formed so as to be bent toward the long axis of the chip mounting area A.

The input / output wiring patterns 322a and 322b formed on the upper surface of the base film 321 are protected by a protective layer (not shown) such as a solder resist.

When such a COF 300 is attached to the liquid crystal panel 200 (FIG. 6) and the printed circuit board (FIG. 6), the edge portion of the base film 321 on which the sprocket holes are formed is removed.

In the embodiment of the present invention, first, the printed circuit board 400 can be made flexible by using an FPC without using a conventional flat PCB (flat PCB) .

The arrangement relationship of the source driver IC 310 of the COF 300 can be determined by positioning the long side of the source driver IC 310 in the normal direction PD instead of the tangential direction TD of the curvature direction CD, To minimize the resistance. As a result, the chip input section B of the input / output wiring patterns 322a and 322b is bent toward the long axis of the source driver IC 310. [

Through such a configuration, the present invention can provide a liquid crystal display device suitable for a soft display, and can stably supply an electric signal through prevention of departure of the source driver IC 310 and the like.

Although the source driver IC 310 has been described above by way of example, it is applicable to a gate driver IC.

The embodiment of the present invention described above is an example of the present invention, and variations are possible within the spirit of the present invention. Accordingly, the invention includes modifications of the invention within the scope of the appended claims and equivalents thereof.

200: liquid crystal panel 300: COF 310: source driver IC
400: printed circuit board
CD: Curvature direction PD: Normal direction TD: Tangential direction

Claims

A liquid crystal panel;
And a source driver IC connected to the liquid crystal panel and having first and second long sides facing each other and first and second short sides connecting both ends of the first and second long sides, respectively, are mounted;
A printed circuit board connected to the COF and having a connector, a resistor, and a capacitance mounted thereon;
/ RTI >
The source driver IC is characterized in that the first and second long sides are mounted on the COF perpendicularly to the longitudinal direction,
Wherein the COF includes an input wiring pattern connecting an upper end of the COF and an upper end of the first and second long sides and an output wiring pattern connecting the lower end of the COF and the lower ends of the first and second long sides
Liquid crystal display device.

The method according to claim 1,
The COF,
A chip mounting region in which the source driver IC is mounted is defined,
And an input / output wiring pattern including a chip input portion formed around an edge of the chip mounting region,
Wherein the chip input section is configured to be turned on the first and second long sides of the source driver IC
Liquid crystal display device.

The method according to claim 1,
The COF is a polyimide-
Liquid crystal display device.

The method according to claim 1,
Wherein the printed circuit board is made of an FPC having a thickness of 0.5 t or less
Liquid crystal display

The method according to claim 1,
And the long side of the connector and the resistance and the capacitance are mounted on the printed circuit board perpendicularly to the longitudinal line direction
Liquid crystal display device.

A source driver IC formed of first and second short sides connecting first and second long sides facing each other and both ends of the first and second long sides, respectively;
A base film on which a source region of the source driver IC is defined in which the first and second long sides are vertically mounted in the longitudinal direction;
And an input / output wiring pattern including a chip input portion formed around an edge of the chip mounting region
/ RTI >
Wherein the chip input section is bent toward the long side of the source driver IC,
Wherein the input wiring pattern connects an upper end of the base film and an upper end of the first and second long sides, and the output wiring pattern is connected to the lower end of the base film and the lower end of the first and second long sides, film.