JP3473376B2 - Display panel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive material that electrically connects between two substrates of a display panel, particularly a display panel having an electro-optical material such as liquid crystal.

[0002]

2. Description of the Related Art A liquid crystal display panel is one in which liquid crystal is sealed between a device substrate and a counter substrate which is arranged so as to face the device substrate via a square annular seal material. The inside of the overlapped portion is the liquid crystal display area. In addition, at four corners on the outer side of the sealing material, there are usually disposed conductive materials that are interposed between the element substrate and the counter substrate to electrically connect the two substrates.

As the conductive material, for example, a photocurable adhesive, a conductive material such as a cylindrical glass fiber or spherical glass beads whose surface is plated with gold, and a silver powder are mixed and kneaded. After forming the sealing material on the element substrate, dot it on the four corners on the outside of the sealing material with a syringe or the like, then bond the opposing substrates and temporarily press-bond with a predetermined pressure, and then irradiate with light to cure. It is designed to let you. After the curing, the columnar glass fibers or the spherical glass beads ensure electrical conduction between the two substrates and a uniform cell gap.

[0004]

By the way, in recent years, the conductive material is shifting from a cylindrical glass fiber to a spherical glass bead, and in this case, the spherical glass bead keeps a predetermined cell gap uniform after pressure bonding of both substrates. Therefore, a material with low elasticity is used.

However, if spherical glass beads having low elasticity are used, the spherical glass beads cannot follow the deformation due to thermal expansion / contraction or external force after the product is completed. As a result, both spherical glass beads and There may be a case where contact failure occurs between the substrates and the electrical continuity between the two substrates may not be established, resulting in inconvenience of lacking reliability of vertical electrical conduction.

The present invention has been made in order to eliminate such inconvenience, and an object of the present invention is to provide a display panel capable of maintaining a uniform cell gap and improving the reliability of vertical conduction. And

[0007]

In order to achieve the above object, a display panel according to the present invention comprises an electro-optical material sandwiched between a first substrate and a second substrate, In a display panel provided with a conducting material electrically conducting between the second substrate and the second substrate, the conducting material is
The surface is plated with gold to follow the deformation of the display panel.
The first spherical glass for maintaining the contact between the two substrates.
Sub beads and gold plating are applied, and the sergi between both substrates is
In order to keep the cap uniform, the first spherical glass beads
Second spherical glass beads having a smaller elasticity than
Seen, the second of spherical glass and the first of spherical glass beads
The mixing ratio of the Subizu 6: 4 to 9: the first range, the
The diameter of the first spherical glass beads is the same as that of the second spherical glass.
It is characterized in that the diameter is larger than the diameter of the beads .

According to this means, the second spherical glass beads having a small elasticity keep the cell gap between both substrates uniform, and the first spherical glass beads having a large elasticity are subjected to thermal expansion / contraction or external force. Following the deformation of the panel, the contact state between both substrates is maintained and the reliability of vertical conduction is secured. Also, since many spherical glass beads have large elasticity, it is possible to improve the followability to panel deformation due to heat or external force.

The display panel according to the present invention is characterized in that the diameter of the spherical glass beads having a large elasticity is made larger than the diameter of the spherical glass beads having a small elasticity in the range of 0.1 to 0.2 μm.

According to this means, since the diameter of the spherical glass beads having a large elasticity is larger than the diameter of the spherical glass beads having a small elasticity, the spherical glass beads having a large elasticity and the spherical glass beads having a large elasticity when both substrates are pressure-bonded to each other. The reliability of the vertical conduction can be further improved by closely contacting the substrate.

In the liquid crystal panel according to the present invention, in the conductive material, the photocurable adhesive, the silver powder, the spherical glass beads having high elasticity and the spherical glass beads having low elasticity are mixed in a weight ratio. And about 5 (photocurable adhesive): 2 (silver powder): 0.4 (glass beads having high elasticity and spherical glass beads having low elasticity), and the first spherical glass beads having high elasticity and the above The mixing ratio with the second spherical glass beads having a small elasticity is 6: 4 to 9: 1.
The range is set to.

According to this means, since spherical glass beads having a large elasticity are often used, it is possible to improve the followability to panel deformation due to heat or external force.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It demonstrates with reference to FIG.

First, the TFT liquid crystal display panel 120 will be described with reference to FIGS. As shown in FIG. 2, a sealing material 101 is provided on the TFT array substrate (first substrate) 20 along the edge thereof, and in parallel to the inside thereof, a light shielding film such as a black matrix. 1
A light-blocking peripheral partition 102 made of the same material as or a material different from that of 09 is provided. When the TFT array substrate 20 is put in a light-shielding case in which an opening is provided corresponding to the screen display area later, the peripheral parting 102 causes the screen display area to be opened due to a manufacturing error or the like. At least 500 μm around the screen display area so as not to be hidden by the edge, that is, to allow a shift of about several hundred μm with respect to the case of the TFT array substrate 20, for example.
It is formed of a band-shaped light-shielding material having a width of about m or more. The light-shielding peripheral partition 102 is
For example, it is formed on the counter substrate by sputtering using a metal material such as chromium or nickel, fogolithography and etching. Alternatively, it is formed from a material such as resin black in which carbon or titanium is dispersed in a photoresist. A data line driving circuit 103 and a mounting terminal 104 are provided along an edge of the TFT array substrate 20 in a region outside the sealing material 101.
05 is provided along two sides adjacent to this one side. Further, on the remaining one side of the TFT array substrate 20, a plurality of wirings 106 for connecting between the scanning line driving circuits 105 provided on both sides of the screen display area 113 are provided.

Further, at the four outer corners of the sealing material 101,
TFT array substrate 20 and counter substrate (second substrate) 108
A conductive material 107 is provided for electrical conduction between the and. In the figure, reference numeral 205 denotes the mounting terminal 10.
4 is an FPC (flexible printed circuit board).

As shown in FIG. 3, the sealing material 1 is formed smaller than the TFT array substrate 20 shown in FIG.
A rectangular counter substrate 108 having substantially the same contour as 01 is bonded to the TFT array substrate 20 via a sealant 101. At the time of bonding, the inside of the peripheral partition 102 at the portion where the TFT array substrate 20 and the counter substrate 108 overlap each other is the screen display region 113.

The data line driving circuit 103 and the scanning line driving circuit 105 are electrically connected to a data line as a source electrode and a scanning line as a gate electrode (both not shown) via wiring. Data line drive circuit 10
An image signal converted into a format that can be immediately displayed is input from a control circuit (not shown) to the scanning line driving circuit 3.
The data line driving circuit 103 sends a signal voltage corresponding to an image signal to the data line (source electrode) in accordance with the pulse voltage 05 sent to the scanning lines in sequence.

Particularly in this embodiment, since the TFT 111 is a p-Si (polysilicon) type TFT,
The data line driving circuit 1 is formed in the same process when the TFT 111 is formed.
03 and the scanning line drive circuit 105 can be formed, which is advantageous in manufacturing.

An example of a process of assembling the TFT liquid crystal display panel 120 will be briefly described with reference to FIG. 4. After receiving and cleaning the TFT array substrate 20 and the counter substrate 108 as element substrates, both substrates 20, 108 are provided. An alignment film of polyimide, polyvinyl alcohol, or the like is formed on the surface of each of these, and then the surface of the alignment film is rubbed with a cloth material such as rayon or nylon. It should be noted that you may wash after rubbing.

Next, after the above-mentioned sealing material 101 is formed on the TFT array substrate 20 side by screen printing or the like, an aluminum pad 200 arranged at four outer corners of the sealing material 101 is electrically connected between both substrates 20, 108. A conductive material 107 that conducts to the above is applied.

The conductive material 107 is obtained by mixing a photocurable adhesive with spherical glass beads as a conductive material having a gold-plated surface and silver powder (granular silver ground) and kneading these. The aluminum pad 200 is spotted by air pressure using a syringe or the like.

Next, the two substrates 20 and 108 are sealed with the sealing material 10.
After laminating via 1 (in the case of photo-curing property) and performing alignment of the cell gap and the like, a certain amount of pressure is applied to press the substrates 20 and 108 under pressure.

Then, the conductive material 107 and the sealing material 101 are cured by irradiating light, and after the curing, both substrates 20,
The liquid crystal 112 is injected between 108, and after the injection is completed, the injection port is sealed with the sealing material 110. This completes the assembly of the TFT liquid crystal display panel 120. After the completion of the assembling, the TFT liquid crystal display panel 120 is washed and then subjected to a predetermined inspection.

Here, in this embodiment, the spherical glass beads contained in the above-mentioned conductive material 107 are improved as follows.

FIG. 1 is an explanatory view for explaining an example of the embodiment according to the present invention, and schematically shows a cross section of the conductive material 107.

In this embodiment, as the conductive material 107, a mixture 300 of a photo-curable adhesive and silver powder, in which spherical glass beads 301 with small elasticity and spherical glass beads 302 with large elasticity are mixed is used. ing. Both the spherical glass beads 301 and 302 have their surfaces plated with gold as described above, and the diameter of the spherical glass beads 301 having a small elasticity varies depending on the model, but is generally 3.3.
It is set to ˜3.5 μm. Incidentally, the sealing material 10
3.0μ by mixing 2.5μm spherical glass beads with 1
In order to achieve a cell gap of m, the spherical glass beads 301 have a diameter (including the gold plating thickness) of 3.3 μm. On the other hand, spherical glass beads 302 with high elasticity
The diameter may be the same as that of the spherical glass beads 301, but the aluminum pad 200 on the element substrate 20 side and the ITO (Indium-Tin-O) on the counter substrate 108 side may be used.
xide) In order to improve the adhesion to the film 201, the diameter is preferably larger than the diameter of the spherical glass beads 301 in the range of 0.1 to 0.2 μm.

Here, in this embodiment, the compounding ratio of the photocurable adhesive, the silver powder, and the spherical glass beads 301, 302 is about 5 (photocurable adhesive): 2 (silver powder): by weight.
0.4 (spherical glass beads 301, 302),
The mixing ratio of the spherical glass beads 301 having low elasticity and the spherical glass beads 302 having high elasticity is preferably 4: 6 to.
The range is 1: 9 (that is, the spherical glass beads having a large elasticity are larger), and more preferably 3: 7. If the mixing ratio of the spherical glass beads 302 having high elasticity is too large, a uniform cell gap may not be ensured, and if too small, the followability to panel deformation due to heat or external force may deteriorate.

As is apparent from the above description, in this embodiment, as the conducting material 107, the spherical glass beads 3 having a small elasticity are added to the mixture 300 of the photocurable adhesive and the silver powder.
01 and the spherical glass beads 302 having a large elasticity are mixed, the spherical glass beads 301 having a small elasticity keeps the cell gap between the substrates 20 and 108 uniform, and the spherical glass beads has a large elasticity. The glass beads 302 follow the deformation of the panel due to thermal expansion / contraction or external force, and the contact state between the substrates 20 and 108 is maintained in a good condition, and the reliability of vertical conduction is ensured.

Further, spherical glass beads 30 having high elasticity
2 diameter of spherical glass beads with small elasticity 301
By increasing the diameter in the range of 0.1 to 0.2 μm, the adhesion between the spherical glass beads 302 and the substrates 20 and 108, which have large elasticity when the substrates 20 and 108 are pressure bonded, is improved. The reliability of vertical conduction can be further improved.

In the above embodiment, the TFT liquid crystal display panel 120 is used as an example of the display panel. However, the display panel is not limited to this. A liquid crystal display panel other than the TFT liquid crystal display panel 120 or an electro-optical material other than liquid crystal is used. It goes without saying that the present invention can be applied to a display panel having.

[0031]

As is apparent from the above description, in the inventions of claims 1 and 2, both the securing of a uniform cell gap between both substrates and the securing of the vertical conduction of both substrates are simultaneously achieved. The effect that can be obtained is obtained.

According to the invention of claim 3, in addition to the invention of claim 1, the adhesion between the spherical glass beads and the both substrates, which have a large elasticity when the two substrates are pressure-bonded, improves the reliability of the vertical conduction. The effect that it can be raised more is acquired.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view for explaining an example of an embodiment according to the present invention.

FIG. 2 is a schematic plan perspective view of a TFT liquid crystal panel.

3 is a sectional view taken along line HH of FIG.

FIG. 4 is a flow chart diagram for explaining a process of assembling the liquid crystal display panel.

[Explanation of symbols]

20 ... TFT array substrate (first substrate) 107 ... Conductive material 108 ... Counter substrate (second substrate) 113 ... Image display area (electro-optical display area) 120 ... TFT liquid crystal display panel (display panel) 200 ... Aluminum pad 201 ... ITO film 300 ... Mixture of photocurable adhesive and silver filler 301 ... Spherical glass beads with low elasticity 302 ... spherical glass beads with high elasticity

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Claims (3)

(57) [Claims] 1. An electro-optic material between a first substrate and a second substrate.
Between the first substrate and the second substrate
A table equipped with a conductive material that electrically connects the two boards between them.
In the display panel,The conductive material has a gold-plated surface, and the display panel
To maintain contact between the two substrates by following the deformation of the board.
First spherical glass beads, Gold plating is applied to make the cell gap between both substrates uniform.
More elastic than the first spherical glass beads to keep in
Includes a second spherical glass bead having a small The first spherical glass beads and the second spherical glass beads
The mixing ratio with the dose is in the range of 6: 4 to 9: 1, The diameter of the first spherical glass beads is the same as that of the second spherical glass beads.
Table with a diameter larger than the diameter of the glass beads
Show panel. 2. The display panel according to claim 1, wherein the conductive material contains a photo-curable adhesive and silver powder. 3. The diameter of the spherical glass beads having a large elasticity is set to 0.1 to less than the diameter of the spherical glass beads having a small elasticity.
The display panel according to claim 1, wherein the display panel has a large diameter in the range of 0.2 μm.