KR20090070944A - Liquid crystal display device - Google Patents

Abstract

A liquid crystal display in which the heat radiation efficiency of a driver IC is remarkably improved is provided to improve the device reliability and extend the lifetime of the driver IC. A plurality of driver ICs(Integrated Circuits) is connected to a liquid crystal panel. First and second heat radiating members including a thermal expansion coefficient is adhered to both side of the driver IC. A top cover is contacted with the first heat radiating member. A top cover surrounds the upper side of the liquid crystal panel. The first and second heat radiating members include the coating layer of the synthetic resin for protecting the metal layer at the upper part of the metal layer. An FPC assembly(300) is formed according to coat of the heat radiating member which is connected to a data PCB(Printed Circuit Board).

Description

Liquid crystal display device

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device in which the heat dissipation effect of the driver IC is remarkably improved.

A liquid crystal display device displays an image using the optical anisotropy and polarization property of the liquid crystal. Since the liquid crystal has a thin and long molecular structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

Therefore, if the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and the polarization state of light is changed in the molecular arrangement direction of the liquid crystal due to optical anisotropy, thereby displaying an image.

Accordingly, a liquid crystal display device includes a liquid crystal panel in which a pair of first and second substrates having a transparent field generating electrode formed on a surface facing each other with a liquid crystal layer interposed therebetween, and a backlight for supplying light thereto. backlight), and by controlling the electric field between two field generating electrodes of the liquid crystal panel to artificially adjust the direction of the liquid crystal molecules to generate a difference in transmittance and to pass the light generated from the backlight through such a liquid crystal panel difference in the transmittance Is displayed to the outside to display various images.

1 is a perspective view of such a liquid crystal display device, wherein the liquid crystal panel 10 having the above-described configuration includes a first substrate 12 and a second substrate 14 having a liquid crystal layer (not shown) therebetween. It is in a state of facing together. In addition, a backlight 20, which is a dimming means, is provided on the rear surface of the liquid crystal panel 10.

At this time, since the first substrate 12 has a larger area than the second substrate 14, two adjacent edges of the first substrate 12 are exposed to the outside when they are bonded together, although they are not clearly shown in the drawings. There are a plurality of data pads and gate pads at the two edges, respectively, and data lines and gate lines are connected to each other.

Each of the plurality of data pads and the gate pads is connected to an external printed circuit board 18 through the FPC 16. The printed circuit board 18 supplies various signals necessary for displaying an image of the liquid crystal panel 10. The driving circuit (not shown) to generate is mounted, and the FPC 16 scans the image signal and the gate line to the data line of the liquid crystal panel 10 through signals transmitted from the printed circuit board 18. Data and gate driver ICs 15 for generating and outputting signals are mounted.

On the other hand, in the general liquid crystal display device having the above-described configuration, when the image is displayed, high temperature heat is gradually generated from the respective driver ICs 15, which greatly shortens the lifespan of the driver ICs 15 as well as deteriorates reliability. Distortion or the like occurs.

This results in a problem of deterioration of the image quality of the liquid crystal display device.

Disclosure of Invention The present invention is to solve the above problems, and proposes a structure capable of dissipating high temperature heat generated from the driver IC quickly and effectively, thereby extending the life of the driver IC and improving device reliability. The purpose.

For this reason, the second object is to prevent the deterioration of the image quality of the liquid crystal display device.

In order to achieve the above object, the present invention is a liquid crystal panel; A plurality of driver ICs connected to the liquid crystal panel; First and second heat dissipation members attached to both outer surfaces of the driver IC and having different thermal expansion coefficients; A liquid crystal display (LCD) includes a top cover in contact with the first heat dissipation member, the top cover having edges surrounding upper and side surfaces of the liquid crystal panel.

In this case, the first heat dissipation member attached to one surface of the driver IC facing the top cover has a larger coefficient of thermal expansion than the second heat dissipation member attached to the other surface of the driver IC. The member may be restored to its original state when the temperature is lowered.

In addition, the first and second heat dissipation member is characterized in that the metal film, the first and second heat dissipation member is characterized in that it further comprises a coating layer of synthetic resin for protecting the metal film on the upper portion of the metal film. .

At this time, the thickness of the first and second heat dissipation member is characterized in that 0.1 ~ 0.2mm, the first heat dissipation member is an alloy of nickel (Ni), manganese (Mn), iron (Fe), nickel (Ni) An alloy of molybdenum (Mo), iron (Fe), an alloy of nickel (Ni), manganese (Mn), copper (Cu), and the second heat dissipation member is compared with the first heat dissipation member. It is characterized by consisting of an alloy of nickel (Ni) and iron (Fe) low thermal expansion coefficient.

In addition, the upper surface of the top cover is characterized in that the embossed (embo) is formed to protrude toward the liquid crystal panel, the liquid crystal panel includes a first and second substrate bonded to face the liquid crystal layer between The plurality of driver ICs may be connected along at least one edge of the first substrate.

In this case, the driver IC is a gate and a data driver, wherein the first and second heat dissipation members are attached to both outer surfaces of the data driver, and the first and second heat dissipation members are both outer surfaces of the gate driver. It is characterized in that attached to.

As described above, the first and second heat dissipation members having different thermal expansion coefficients are coated on both outer surfaces of the FPC mounted with the driver IC according to the present invention, and the FPC is actively bent when high temperature heat is generated from the driver IC. By making contact with the emboss of the top cover, the high temperature heat generated from the driver IC can be dissipated quickly and effectively.

As a result, not only the life of the driver IC can be extended, but also the device reliability can be greatly improved, and the quality of the liquid crystal display device can be improved.

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

2 is a perspective view of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 3 is a perspective view of a part of a liquid crystal panel.

As shown in FIG. 2, the LCD device includes a liquid crystal panel 110 including first and second substrates 112 and 114 bonded to each other with a liquid crystal layer interposed therebetween and driver ICs 115a and 115b. ) Includes data and gate printed circuit boards 118a and 118b connected to two adjacent edges of the liquid crystal panel 110 via a plurality of FPCs 116 mounted thereon.

At this time, both outer surfaces of the FPC 116 connected to the data printed circuit board 118a are coated with heat dissipation members 160a and 160b covering the driver IC 115a to form the FPC assembly 300.

Here, this will be described in more detail with reference to FIG. 3, which is an exploded perspective view of the liquid crystal panel 110.

In the liquid crystal panel 110, a plurality of data lines 212 and gate lines 216 vertically cross each other on one surface of the first substrate 112 called a lower substrate or an array substrate to define the pixel area P. do. Thin film transistors T are provided at the intersections of these two lines to correspond one-to-one with the transparent pixel electrodes 220 provided in the pixel regions P. FIG.

In addition, the second substrate 114 facing the liquid crystal layer 225 therebetween is called an upper substrate or a color filter substrate, and one surface thereof has a data line 212 of the first substrate 112. A grid-like black matrix 232 is formed around the pixel region P to cover only the pixel electrode 220 while covering the non-display elements such as the gate line 216 and the thin film transistor T.

In addition, as an example, the R, red, G, and B color filters 234 are sequentially and repeatedly arranged corresponding to each pixel region P in the lattice. 236).

In addition, although not clearly shown in the drawings, the upper and lower alignment layers for determining the initial molecular alignment direction of the liquid crystal are interposed between the two substrates 112 and 114 and the liquid crystal layer 225, and the liquid crystal filled therebetween. Seal patterns are formed along the edges of both substrates 112 and 114 to prevent leakage of the layer 225, and only specific light is selectively selected as an outer surface of the first and second substrates 112 and 114. A polarizing plate to transmit through may be attached.

In addition, since the first substrate 112 has a larger area than the second substrate 114, one side edge of the first substrate 112 is exposed to the outside when the two substrates 114 are bonded to each other. A plurality of data pads 214 connected to each other and a plurality of gate pads (not shown) connected to the plurality of gate lines 216 are positioned.

Each of the plurality of gates and data pads 214 is connected to external data and gate printed circuit boards 118a and 118b through a tape automated bonding (TAB) method, respectively. , 118b is mounted with a driving circuit for generating various signals required for image expression of the liquid crystal panel 110.

Here, the TAB method is used in a broad sense including a tape carrier package (TCP), a chip on film (COF), and a chip on glass (COG). In the present invention, driver ICs 115a and 115b are mounted as shown. Flexible printed circuit board 116 may be used.

At this time, first and second wiring patterns (not shown) drawn from the driver ICs 115a and 115b are aligned at both edges of the FPC 116, and both edges of the FPC 116 are formed at the edges of the liquid crystal panel 110. 1 is bonded and connected to the substrate 112 and the data and gate printed circuit boards 118a and 118b through ACF (not shown), respectively.

Accordingly, the gate and the data pad (not shown) 214 of the first substrate 112 are connected to the data and gate via the first and second wiring patterns (not shown) of the FPC 116 and the driver ICs 115a and 115b. It is electrically connected to the drive circuits of the printed circuit boards 118a and 118b.

The driver IC 115b of the FPC 116 connecting the gate pad (not shown) and the gate printed circuit board 118b at one edge of the liquid crystal panel 110 forms a gate driver and transmits various signals transmitted from the driving circuit. The driver of the FPC 116 generates a gate signal that is scanned and transferred to the gate line 216 based on the data line, and connects the data pad 214 and the data printed circuit board 118a to the other edge of the liquid crystal panel 110 adjacent thereto. The IC 115a configures a data driver to generate a data signal transmitted to the data line 212 based on various signals transmitted from the driving circuit.

In this case, the gate signal controls the on / off of the thin film transistor T of each gate line 216, and the data signal is a substantially liquid crystal that is transmitted to the pixel electrode 220 of each gate line 216. (225) acts as the driving voltage.

Accordingly, the liquid crystal panel 110 is turned on by the on / off signal of the thin film transistor T that is scanned and transferred to the gate line 216. When turned on, the image signal of the data line 212 is transmitted to the pixel electrode 220, and is changed in the arrangement direction of the liquid crystal molecules by the electric field between the pixel electrode 220 and the common electrode 236. The difference in transmittance is shown.

On the other hand, the outer surface of the FPC 116 connected to the data printed circuit board 118a is characterized in that the heat radiation member (160a, 160b) for quickly dissipating heat generated from the driver IC (115a) is coated. .

The heat dissipation members 160a and 160b are divided into first and second heat dissipation members according to the attachment positions of both outer surfaces of the FPC 116. The first and second heat dissipation members 160a and 160b have different coefficients of thermal expansion. .

The rear surface of the liquid crystal display device is provided with a backlight for supplying light from the rear surface thereof so that the difference in transmittance of the liquid crystal panel 110 is expressed to the outside and integrally modularized.

4 is an exploded perspective view showing a liquid crystal display module according to an embodiment of the present invention.

Here, the driver IC 115a is mounted and adjacent to the data printed circuit board 118a via the FPC assembly 300 having the first and second heat dissipation members 160a and 160b coated on both outer surfaces thereof. The liquid crystal panel 110 is connected to the gate printed circuit board 118b via the FPC 116 on which the gate driver 115b is mounted, and the backlight unit 120 supplies light to the liquid crystal panel 110 on the rear surface thereof. This is located.

The backlight unit 120 includes a lamp 124 arranged along at least one edge length direction of the support main 130, a reflecting plate 122, a light guide plate 126 mounted on the reflecting plate 122, and an upper portion thereof. It includes a plurality of interposed optical sheet 128.

At this time, the lamp guide 125 for guiding the lamp 124 is further provided.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the top cover 140, the support main 130, and the cover bottom 150. The top cover 140 is the top and side surfaces of the liquid crystal panel 110. Configure to cover the edges.

In addition, the liquid crystal panel 110 and the backlight unit 120 are surrounded by edges through the support main 130 having a rectangular frame shape.

In addition, the cover bottom 150 on which the liquid crystal panel 110 and the backlight unit 120 are surrounded by the support main 130 is seated in a rectangular plate-shaped bottom surface and its edges are bent upwards. Consists of three aspects.

Meanwhile, the top cover 140 may be referred to as a case top or a top case, the support main 130 may be referred to as a guide panel or a main support, and a mold frame, and the cover bottom 150 may be referred to as a bottom cover.

At this time, although not shown in the drawing, the upper surface of the top cover 140 is characterized in that it further comprises an emboss (embo) concave toward the liquid crystal panel 110.

The emboss is in contact with the FPC 116, thereby radiating heat generated from the driver IC 115a mounted in the FPC 116 to the outside.

That is, the printed circuit boards 118a and 118b are folded and adhered to the side or the rear surface of the liquid crystal panel 110 by using the bending characteristics of the FPC 116. In this case, the FPC 116 connected to the data printed circuit board 118a is closely attached. And the emboss of the top cover 140 are in contact with each other.

At this time, when the image of the liquid crystal panel 110 is represented, the high temperature heat generated from the driver IC 115a is conducted to the top cover 140 to be emitted to the outside. Therefore, the high temperature heat generated from the driver IC 115a can be dissipated quickly and effectively, thereby extending the life of the driver IC 115a and greatly improving the device reliability.

In addition, there is an effect of improving the image quality of the liquid crystal display device.

At this time, the FPC 116 is in contact with the emboss only at a high temperature, which is due to the first and second heat dissipation member (160a, 160b) coated on both outer surfaces of the FPC 116, with reference to FIG. Let's take a closer look.

5 is a perspective view illustrating a state in which the heat dissipation member is attached to both outer surfaces of the FPC.

As illustrated, the heat dissipation members 160a and 160b are coated on both outer surfaces of the FPC 116 in which the driver IC 115a is mounted, and the upper side of the one side on which the driver IC 115a of the FPC 116 is mounted is shown. If the other side, which is called the surface and the other side is the lower surface, the first surface of the heat dissipation member (160a) is coated on the upper surface of the FPC 116, the second surface of the heat dissipation member (160b).

At this time, the first heat dissipation member 160a and the second heat dissipation member 160b are flexible thin metal films, and may be formed of a coating layer of synthetic resin coated on the surface thereof to protect the metal films.

In particular, the first heat dissipation member 160a and the second heat dissipation member 160b have different coefficients of thermal expansion, whereby the first and second heat dissipation members 160a and 160b have the same effect as a bimetal. .

Here, bimetal is a part made of one sheet by superimposing two kinds of thin metal plates having very different thermal expansion coefficients, and controls the device according to the temperature by using the bending property when heat is applied. That is, when the temperature increases, the side with the higher coefficient of thermal expansion expands more and bends to the opposite side. When the temperature decreases, the bimetal returns to its original state.

Therefore, the first heat dissipation member 160a made of a metal film having a larger thermal expansion coefficient is coated on the upper surface on which the driver IC 115a of the FPC 116 is mounted, and the thermal expansion coefficient is higher than that of the first heat dissipation member 160a. By coating a second heat dissipation member 160b made of a low metal film on the lower surface of the FPC 116, when a high temperature heat is generated from the driver IC 115a, the first heat dissipation member 160a is formed by the second heat dissipation member 160b. While being bent significantly compared to the a) it comes into contact with the emboss of the top cover (140 of FIG. 4).

Through this, the heat generated from the driver IC 115a can be easily conducted to the top cover (140 of FIG. 4) to be discharged.

In addition, when the temperature of the driver IC 115a is lowered by dissipating high temperature heat from the driver IC 115a, the FPC 116 returns to its original state.

In this way, if the FPC 116 is restored to its original state, it is possible to prevent the occurrence of a crack in the driver IC 115a when an external vibration or shock is applied.

At this time, the first heat dissipation member 160a is an alloy of nickel (Ni), manganese (Mn), iron (Fe) having a high coefficient of thermal expansion, an alloy of nickel (Ni), molybdenum (Mo), iron (Fe), and nickel ( One of an alloy of Ni), manganese (Mn), and copper (Cu) is formed, and the second heat dissipation member 160b has a lower thermal expansion coefficient than nickel (Ni) and iron (Fe) than the first heat dissipation member 160a. It is preferable to use an alloy of.

In addition, when the thickness of the first and second heat dissipation members 160a and 160b is increased, more excellent heat dissipation effect may be obtained, but it may interfere with the liquid crystal display module modularization process, so that about 0.1 to 0.2 mm is preferable.

6 is a cross-sectional view schematically showing how the FPC is in contact with the emboss of the top cover.

As illustrated, the reflective plate 122, the light guide plate 126, a lamp (124 of FIG. 4) positioned on one side of the light guide plate 126, and a plurality of optical sheets 128 are stacked on the light guide plate 126. The support unit 130 covering the backlight unit, the edges of the backlight unit and the liquid crystal panel 110 disposed thereon, and the cover bottom 150 are coupled to the rear surface thereof, and the top and side edges of the liquid crystal panel 110 are combined. The top cover 140 surrounding the support main 130 and the cover bottom 150 is coupled.

In this case, an emboss 142 protrudes concave toward the liquid crystal panel 110 is formed inside the upper surface of the top cover 140, and the liquid crystal panel 110 has a first substrate and a second substrate ( 112 and 114, a printed circuit board 118 is connected to the first substrate 112 via an FPC 116 in which a driver IC (115a in FIG. 5) is mounted.

The printed circuit board 118 is folded and adhered to the side of the support main 130 through the FPC assembly 300 having flexibility, and the thermal expansion coefficients of the FPC assembly 116 are different from each other on the outer surface of the FPC assembly 300. First and second heat dissipation members 160a and 160b are attached.

Here, the thermal expansion coefficient of the first heat dissipation member 160a is greater than the thermal expansion coefficient of the second heat dissipation member 160b, and the first and second heat dissipation members 160a and 160b have a bimetal effect.

At this time, when high temperature heat is generated from the driver IC mounted on the FPC 116 (115a in FIG. 5), the first heat dissipation member 160a having a large thermal expansion coefficient expands more than the second heat dissipation member 160b. As it is bent, the FPC assembly 300 comes into contact with the emboss 142 of the top cover 140.

Therefore, the high temperature heat generated from the driver IC (115a in FIG. 5) can be dissipated quickly and effectively.

As described above, the FPC assembly 300 according to the present invention is bent actively when high temperature heat is generated from the driver IC (115a of FIG. 5) in contact with the emboss 142 of the top cover 140, the driver IC It is possible to quickly and effectively dissipate the high temperature heat generated from (115a in FIG. 5), thereby greatly improving the device reliability as well as extending the life of the driver IC (115a in FIG. 5). In addition, there is an effect of improving the image quality of the liquid crystal display device.

Meanwhile, in the description of the present invention and the accompanying drawings, the first and second heat dissipation members 160a and 160b are shown to be attached only to the FPC 116 connected to the data printed circuit board 118a. This is because the structure is relatively complicated and high temperature heat is generated when the image is expressed, and may be attached to the FPC 116 connected to the gate printed circuit board 118b depending on the purpose.

In addition, in the description of the present invention and the accompanying drawings, although the lamp 124 of FIG. 4 shows an edge type arrangement along the inner longitudinal direction of the support main 130, the upper front surface of the reflecting plate 122 is shown. As a result, a direct type in which a plurality of lamps 124 of FIG. 4 are arranged side by side may be possible. In the case of the direct type, the light guide plate 126 may be omitted.

FIG. 7 is an image representation of a liquid crystal display device having a first IC and a second heat dissipation member having different thermal expansion coefficients on both outer surfaces of the FPC as shown in the present invention. This is a graph showing the temperature of the driver IC at the time.

Referring to this, the maximum heat generation temperature of the conventional driver IC represents 90 ℃, while the maximum heat generation temperature of the driver IC according to an embodiment of the present invention represents 80 ℃, compared to the conventional maximum heat generation temperature of the driver IC It can be seen that is lowered by about 10 ℃.

Accordingly, it can be seen that by attaching the first and second heat dissipation members having different thermal expansion coefficients to both outer surfaces of the FPC according to the embodiment of the present invention, it is possible to effectively discharge the high temperature heat generated from the driver IC.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is a perspective view of a general liquid crystal display device.

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

3 is a perspective view of a part of a liquid crystal panel;

4 is an exploded perspective view showing a liquid crystal display module according to an embodiment of the present invention.

Figure 5 is a perspective view showing a state that the heat radiation member is attached to both outer surfaces of the FPC.

6 is a cross-sectional view schematically showing the FPC is in contact with the emboss of the top cover.

7 is a graph showing a comparison of the temperature of a conventional driver IC and the temperature of the driver IC with a heat radiation member according to an embodiment of the present invention.

Claims (11)

A liquid crystal panel; A plurality of driver ICs connected to the liquid crystal panel; First and second heat dissipation members attached to both outer surfaces of the driver IC and having different thermal expansion coefficients; A top cover in contact with the first heat dissipation member and having an edge around the top and side surfaces of the liquid crystal panel Liquid crystal display comprising a. The method of claim 1, And a first thermal radiation member attached to one surface of the driver IC facing the top cover of the driver IC has a larger thermal expansion coefficient than the second thermal radiation member attached to the other surface of the driver IC. The method of claim 2, And the first and second heat dissipation members are restored to their original state when the temperature is lowered. The method of claim 2, And the first and second heat dissipation members are metal films. The method of claim 4, wherein And the first and second heat dissipation members further include a coating layer of synthetic resin on the metal film to protect the metal film. The method of claim 4, wherein The thickness of the first and second heat dissipation member is 0.1 ~ 0.2mm characterized in that the liquid crystal display device. The method of claim 4, wherein The first heat dissipation member includes an alloy of nickel (Ni), manganese (Mn), iron (Fe), an alloy of nickel (Ni), molybdenum (Mo), iron (Fe), nickel (Ni), manganese (Mn), It is made of one metal of the alloy of copper (Cu), the second heat dissipation member is a liquid crystal display, characterized in that made of an alloy of nickel (Ni) and iron (Fe) having a lower coefficient of thermal expansion than the first heat dissipation member Device. The method of claim 1, And an embo in which an image protrudes toward the liquid crystal panel is formed inside the upper surface of the top cover. The method of claim 1, And the liquid crystal panel includes first and second substrates bonded to each other with a liquid crystal layer interposed therebetween, and a plurality of driver ICs are connected along at least one edge of the first substrate. The method of claim 9, Wherein the driver IC is a gate and a data driver, and the first and second heat dissipation members are attached to both outer surfaces of the data driver. The method of claim 10, And the first and second heat dissipation members are attached to both outer surfaces of the gate driver.

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