LCD panel

Abstract

To provide a liquid crystal display panel that can suppress decreased productivity, increased production costs, and degradation of image quality. [Solution] A liquid crystal panel 1 is formed by bonding a first substrate 2 having a first electrode (pixel electrode 14) for applying voltage to the liquid crystal 12 and a second substrate 3 having a second electrode (common electrode 11) for applying voltage to the liquid crystal 12 via a peripheral seal 4 so that the first electrode (pixel electrode 14) and the second electrode (common electrode 11) face each other, thereby enclosing the liquid crystal 12 in a space, and the first substrate 2 and the second substrate 3 are electrically connected via a conductive adhesive 6, the conductive adhesive 6 being made of a material in which conductive nanopowder 9 is mixed with the same material as the peripheral seal 4.

Description

Technical Field

[0001] The present invention relates to a liquid crystal panel.

Background Art

[0002] FIG. 4 is (a) a top view and (b) an A-A' cross-sectional view showing a liquid crystal panel in the prior art. In the liquid crystal panel 1 of the prior art, the pixel electrode 14 is formed on the first substrate 2 among the two substrates, the alignment film 10 is formed on the pixel electrode 14, the common electrode 11 corresponding to the pixel electrode 14 is formed on the other second substrate 3, the alignment film 10 is formed on the common electrode 11, a peripheral seal 4 containing a spacer 15 is provided so as to surround the pixel electrode 14, the first substrate 2 and the second substrate 3 are aligned and bonded to each other by the peripheral seal 4, and liquid crystal 12 is injected into the space inside the peripheral seal 4 formed thereby. The liquid crystal 12 is injected from a liquid crystal injection port 16 provided in a part of the peripheral seal 4, and is sealed inside the peripheral seal 4 by sealing the liquid crystal injection port 16 with a sealing material (not shown) made of the same material as the peripheral seal 4.

[0003] The first substrate 2 and the second substrate 3 are electrically connected to each other via a conductive adhesive 6. Specifically, inside the conductive adhesive 6, for example, conductive spheres 7 having a diameter of about 2.5 μm are arranged, through which the electrode 13 on the first substrate 2 and the common electrode 11 on the second substrate 3 are electrically connected. In addition, the electrode 13 on the first substrate 2 is electrically connected to the electrode 13 on the circuit board 5 via a wire 8.

[0004] The technique of electrically connecting the first substrate 2 and the second substrate 3 via a conductive adhesive as described above is a well-known technique (for example, see Patent Document 1). In addition, the technique of electrically connecting the second substrate 3 and the circuit board 5 via a conductive adhesive without going through the first substrate 2 is also a well-known technique (for example, see Patent Document 2).

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-045470 [Patent Document 2] Japanese Patent Publication No. 2009-192858 [Overview of the project] [Problems that the invention aims to solve]

[0006] In conventional liquid crystal panels, as shown in Figure 4, conductive spheres of a size that fits the gaps between substrates must be prepared each time, which can lead to a decrease in the productivity of the liquid crystal panels. Furthermore, since conductive spheres are generally expensive, this can lead to an increase in the production cost of the liquid crystal panels. In addition, the gaps between the substrates of the liquid crystal panel may change due to the expansion and contraction of the conductive adhesive, which can lead to a decrease in image quality.

[0007] This invention has been made in view of the above problems, and aims to provide a liquid crystal panel that can suppress a decrease in productivity, an increase in production costs, and a decrease in image quality. [Means for solving the problem]

[0008] A liquid crystal panel comprising a first substrate having a first electrode for applying voltage to the liquid crystal and a second substrate having a second electrode for applying voltage to the liquid crystal, wherein the first electrode and the second electrode are bonded together via a peripheral seal so that they face each other, and liquid crystal is sealed in a space formed therein, and the first substrate and the second substrate are electrically connected via a conductive adhesive, wherein the conductive adhesive is made of a material in which conductive nanopowder is mixed with the same material as the peripheral seal.

[0009] The particle size of the nanopowder is 10 to 50 nm, and the liquid crystal display panel may also be one such panel.

[0010] The nanopowder may be a liquid crystal display panel composed of an alloy of tungsten and nickel.

[0011] The main components of the conductive adhesive and the peripheral seal may be the same resin, and the liquid crystal display panel may also be one such panel. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a liquid crystal panel that can suppress a decrease in productivity, an increase in production costs, and a decrease in image quality. [Brief explanation of the drawing]

[0013] [Figure 1] (a) Top view and (b) Cross-sectional view of the liquid crystal panel in the present invention along A-A'. [Figure 2] Partially enlarged view of the A-A' cross-sectional view of the liquid crystal panel in the present invention. [Figure 3] Magnified view of the nanopowder mixed into the conductive adhesive in the present invention. [Figure 4] (a) Top view and (b) Cross-sectional view of a liquid crystal display panel in the conventional technology. [Modes for carrying out the invention]

[0014] Figure 1 is (a) a top view and (b) a cross-sectional view along A-A' of the liquid crystal panel according to the present invention. Figure 2 is a partially enlarged view of the cross-sectional view along A-A' of the liquid crystal panel according to the present invention. The liquid crystal panel 1 shown in Figures 1 and 2 is one embodiment of the present invention. The liquid crystal panel 1 according to the present invention has the same basic configuration as the liquid crystal panel 1 in the prior art shown in Figure 4. In the liquid crystal panel 1 according to the present invention, a conductive adhesive 6 is used as the conductive adhesive 6 placed in the gap between the first substrate 2 and the second substrate 3, and is made of the same material as the peripheral seal 4, mixed with, for example, nickel (Ni) and tungsten (W) nanopowder 9. The position where this conductive adhesive 6 is placed is the same as in the liquid crystal panel 1 in the prior art, and is at the corners on both sides of the second substrate 3 located between the peripheral seal 4 and the wire 8. The conductive adhesive 6 is applied in a columnar shape to connect the electrode 13 of the first substrate 2 and the common electrode 11 of the second substrate 3. Inside the conductive adhesive 6, the nanopowder 9 come into contact with each other, for example as shown in Figure 2, thereby electrically connecting the first substrate 2 and the second substrate 3.

[0015] Figure 3 is a magnified view of the nanopowder mixed into the conductive adhesive in the present invention. The conductive adhesive 6 in the present invention is produced by uniformly mixing the nanopowder shown in Figure 3 with the same material as the surrounding seal 4 (for example, epoxy resin or acrylic resin). The nanopowder shown in Figure 3 is composed of an alloy of nickel (Ni) and tungsten (W), and its particle size is approximately 10 to 50 nm. Nickel has the characteristic of being resistant to rust, and tungsten has high heat resistance.

[0016] The conductive adhesive 6 is applied using an application device such as a dispenser. The amount applied is adjusted appropriately so that the gap between the first substrate 2 and the second substrate 3 is filled within the range of the electrode 13. The conductive adhesive 6 is cured after application. The curing method for the conductive adhesive 6 is appropriately selected depending on the material of the conductive adhesive 6, such as thermal curing, moisture curing, or photocuring.

[0017] In the liquid crystal panel 1 of the present invention, since a mixture of the same material as the peripheral seal 9 with nanopowder 9 mixed therein is used as the conductive adhesive 6, the physical properties (linear expansion coefficient, viscosity, hardness, elasticity, etc.) of the conductive adhesive 6 can be made close to the physical properties of the peripheral seal 4. Accordingly, it is possible to suppress the occurrence of various problems caused by the mutual difference in physical properties between the conductive adhesive 6 and the peripheral seal 4. For example, as the linear expansion coefficient of the conductive adhesive 6 approaches the linear expansion coefficient of the peripheral seal 4, a change in the gap between the first substrate 2 and the second substrate 3 caused by the difference in linear expansion coefficients can be suppressed.

[0018] Furthermore, the conductive adhesive 6 mixed with the nanopowder 9 does not require conventional conductive spheres 7, and can be directly used for various types of liquid crystal panels simply by appropriately adjusting the coating amount according to the size of the gap between the first substrate 2 and the second substrate 3, which contributes to cost reduction and productivity improvement of liquid crystal panels.

[0019] Furthermore, when a conventional metal paste (for example, silver paste) is used as the conductive adhesive 6, cracks or the like may occur at the interface with the substrate after curing. However, if the main component is composed of resin as in the conductive adhesive 6 of the present invention, the occurrence of such cracks and the like can be prevented.

[0020] The position of the conductive adhesive 6 can be appropriately changed according to the arrangement of each electrode of the liquid crystal panel 1. For example, when the electrode 13 on the first substrate 2 is provided directly below the peripheral seal 4, the conductive adhesive 6 is arranged inside the peripheral seal 4. When the electrode 13 on the first substrate 2 is provided in the region surrounded by the peripheral seal 4, the conductive adhesive 6 is arranged in the region surrounded by the peripheral seal 4.

[0021] The nanopowder 9 is not limited to being composed of an alloy of nickel (Ni) and tungsten (W), and may be composed of other materials.

[0022] The present invention is not limited to the above embodiments, and may take various other embodiments. [Explanation of symbols]

[0023] 1 LCD panel 2 First board 3 Second board 4. Peripheral seal 5 Circuit board 6. Conductive adhesive 7 Conductive spheres 8 wires 9 nanopowder 10. Orientation film 11 Common electrode 12 LCD 13 electrodes 14 Pixel electrodes 15 Spacers 16 LCD injection port

Claims

1. A liquid crystal panel comprising a first substrate having a first electrode for applying voltage to the liquid crystal and a second substrate having a second electrode for applying voltage to the liquid crystal, wherein the first electrode and the second electrode are bonded together via a peripheral seal so that they face each other, and liquid crystal is sealed in a space formed therein, and the first substrate and the second substrate are electrically connected via a conductive adhesive, The liquid crystal panel is characterized in that the conductive adhesive is made of a material in which conductive nanopowder is mixed with the same material as the surrounding seal.

2. The liquid crystal display panel according to claim 1, characterized in that the particle size of the nanopowder is 10 to 50 nm.

3. The liquid crystal panel according to claim 1, characterized in that the nanopowder is composed of an alloy of tungsten and nickel.

4. The liquid crystal panel according to claim 1, characterized in that the main components of the conductive adhesive and the peripheral seal are the same resin.

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