JPH0756185A - Liquid crystal display device and its assembly - Google Patents

Abstract

PURPOSE:To secure bonding strength between a liquid crystal panel and a surface type connector member. CONSTITUTION:The liquid crystal panel 1 is constituted by sticking a couple of substrates 3 and 4 on each other and holding liquid crystal between the body. The surface type connector member 2 is bonded to an exposed electrode 5 formed on the inside surface of one substrate 3 of the liquid crystal panel 1 and also extends outwardly from an end surface 7 of the substrate 3. At the corner part where the outside surface 8 of the substrate 3 intersects the end surface 7, a ground surface 9 is provided. Resin 10 for reinforcement is provided continuously over the ground surface 9, end surface 7, and the top surface 6 of the surface type connector member 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method for assembling the same. More specifically, it relates to a joint portion reinforcing structure between a liquid crystal panel and a planar connector member.

[0002]

2. Description of the Related Art FIG. 4 is a schematic perspective view showing an example of a conventional active matrix type liquid crystal panel. As shown in the figure, the liquid crystal panel has a structure in which a lower drive substrate 21 and an upper counter substrate 22 are bonded together by a spacer 23, and liquid crystal is held between both substrates. Drive substrate 21
A liquid crystal display section 26 including pixel electrodes 24 arranged in a matrix and switching elements 25 for driving the pixel electrodes 24 and a peripheral drive circuit section 27 connected to the liquid crystal display section 26 are provided on the inner surface of the liquid crystal display panel. Has been formed. The switching element 25 is composed of a thin film transistor. The peripheral drive circuit section 27 is also composed of thin film transistors. On the other hand, a counter electrode and a color filter are formed on the inner surface of the counter substrate 22. The peripheral portion of the surface of the lower drive substrate 21 is exposed from the upper counter substrate 22, and an electrode 28 for external connection is formed in that portion.

[0003]

FIG. 5 is a schematic perspective view showing an example of a conventional liquid crystal display device. As shown in the figure, the liquid crystal display device has a structure in which the liquid crystal panel 20 and the planar connector member 29 are joined to each other. Liquid crystal panel 20
Has the structure shown in FIG. 4, and the drive substrate 21 and the counter substrate 22 are attached to each other and liquid crystal is held between them. It should be noted that the liquid crystal panel 20 is drawn upside down with respect to FIG. The planar connector member 29 is joined to the exposed electrode 28 formed on the peripheral portion of the inner surface of the drive substrate 21 and extends outward from the end surface 30 of the drive substrate 21. The planar connector member 29 is made of, for example, a flexible printed circuit board and is connected to an external circuit. Further, a reinforcing resin 32 is provided over the end surface 30 of the drive substrate 21 and the one surface 31 of the planar connector member 29.

The exposed electrode 28 formed on the drive substrate 21 and the wiring pattern 33 formed on one surface 31 of the planar connector member 29 are joined to each other by, for example, thermocompression bonding. Reinforcing resin 32 to protect this joint and maintain mechanical strength
Has been applied. However, this reinforcing resin 32
Has a problem that it is not always possible to secure sufficient mechanical strength because the adhesive strength to the end surface 30 of the drive substrate 21 varies. The liquid crystal panel 20 has gone through various steps up to the step of joining the planar connector member 29, and the end surface 30 of the drive substrate 21 is not necessarily in a clean state and may be contaminated. Resin 32
There is a large variation in the adhesive strength with respect to. Conventionally, the cleaning process is performed using an organic solvent or the like to remove the contamination of the end face 30, but this is not always sufficient, and the cleanliness of the end face may not be recovered in some cases. Therefore, when the tensile strength test of the planar connector member is carried out at the shipping stage, defects occur depending on the lot, which is a problem.

[0005]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, an object of the present invention is to improve the bonding strength between a liquid crystal panel and a planar connector member. The following measures have been taken in order to achieve this object. That is, the liquid crystal display device according to the present invention has a liquid crystal panel and a planar connector member as basic components. A liquid crystal panel is one in which a pair of substrates are attached to each other and liquid crystal is held between them. The planar connector member is joined to the exposed electrode formed on one substrate of the liquid crystal panel and extends outward from the end face of the substrate. In such a structure, a grinding surface is provided at the corner where the outer surface and the end surface of the one substrate intersect. further,
Reinforcing resin is provided over the ground surface, the end surface, and one surface of the planar connector member.

The liquid crystal display device having the above structure is assembled by the following method. First, a step of making a liquid crystal panel by adhering a pair of substrates to each other and enclosing a liquid crystal between them is performed. Next, a step of joining the planar connector member to the exposed electrode provided in the portion close to the end surface of one substrate is performed. Then, a step of processing a corner portion where the outer surface of one of the substrates and the end surface intersect to provide a ground surface is performed. Finally, the step of supplying the reinforcing resin over the ground surface, the end surface, and one surface of the planar connector member is performed.

[0007]

According to the present invention, the ground surface is provided at the corner where the outer surface and the end surface of the substrate intersect. Even if dirt or the like is attached to the end surface of the substrate, a new grinding surface can be exposed by the polishing process and the dirt is physically removed. Further, this ground surface has a larger roughness and a larger surface area than the end surface. In the present invention, the reinforcing resin is applied not only to one surface of the planar connector member and the end surface of the substrate, but also to the ground surface. In particular, since the bonding strength between the ground surface and the reinforcing resin is increased, the bonding strength between the liquid crystal panel and the planar connector member is increased as a whole.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic side view showing an embodiment of a liquid crystal display device according to the present invention. As shown,
The present liquid crystal display device has a liquid crystal panel 1 and a planar connector member 2 joined together, and basically has a structure similar to that of the conventional example shown in FIG. The liquid crystal panel 1 is formed by sticking a pair of upper and lower glass substrates to each other and holding liquid crystal between them. In this example, the upper drive substrate 3 and the lower counter substrate 4 are bonded together to form an active matrix type liquid crystal panel. However, the present invention is not limited to this, and can be applied to, for example, a simple matrix type liquid crystal panel. A peripheral portion of the inner surface of the drive substrate 3 is partially exposed, and an exposed electrode 5 for connection is formed on the surface. In addition, one surface 6 of the planar connector member 2
An electrode pattern corresponding to is also formed. This electrode pattern and the above-mentioned exposed electrode 5 are bonded to each other by thermocompression bonding or the like. The planar connector member 2 extends outward from the end surface 7 of the drive substrate 3. This planar connector member 2
Is composed of, for example, a flexible printed circuit board and can be directly connected to an external circuit.

As a feature of the present invention, a grinding surface 9 is provided at the corner where the outer surface 8 of the drive substrate 3 and the end surface 7 intersect. The reinforcing resin 10 is provided over the ground surface 9, the end surface 7, and the one surface 6 of the planar connector member 2. In this example, the reinforcing resin 10 is made of an ultraviolet curable adhesive. Alternatively, instead of this, a normal adhesive that is thermoset at a relatively low temperature may be used.

FIG. 2 is an enlarged sectional view of the joint portion of the liquid crystal display device shown in FIG. As illustrated, the reinforcing resin 10 is continuously applied along the ground surface 9, the end surface 7, and the one surface 6 of the planar connector member 2 to mechanically reinforce the joint portion 11. The ground surface 9 is formed by grinding with a diamond file or the like. Therefore, its surface state is rougher and has a larger surface area than the scribe-broken end face 7. Since the surface is rough, the adhesive strength to the reinforcing resin 10 is extremely high. For the purpose of reinforcement, it is sufficient to provide the ground surface 9 having a width of about 0.1 mm along the corner of the drive substrate 3, for example, and there is no fear of damaging the appearance of the liquid crystal panel. Also, the grinding process is extremely easy.

Since the inside of the drive substrate 3 is newly exposed and the grinding surface 9 is a clean surface, sufficient bonding strength to the reinforcing resin 10 can be secured. Even if the end surface 7 of the drive substrate 3 is contaminated with foreign matter in the previous process or the like, the newly formed clean ground surface 9 can ensure the necessary adhesive strength.

As shown by the arrow, a tensile force may act on the planar connector member 2 in a direction perpendicular to the joint surface 11. It should be noted that this pulling direction is the weakest direction in the structure of the joint portion 11, and the pulling inspection and the like are also performed in this state. When the planar connector member 2 is pulled in the vertical direction as shown by the arrow, stress is first concentrated on the bonded portion between the ground surface 9 and the reinforcing resin 10. However, since the strength of this adhesive portion is higher than that of the conventional one, the reinforcing resin 10 does not easily peel off. Further, since the grinding surface 9 is arranged obliquely with respect to the pulling direction, it is possible to disperse the stress concentration. On the other hand, in the conventional structure, since stress concentrates on the bonding portion between the end face of the substrate and the reinforcing resin 10, peeling occurs extremely easily.

FIG. 3 is a process chart showing an example of a method of assembling the liquid crystal display device according to the present invention. First, in step A, a pair of substrates 3 and 4 are attached to each other, and liquid crystal is sealed between them to form a panel. In the case of an active matrix type liquid crystal panel, the upper drive substrate 3 is made of quartz glass or the like, and the lower counter substrate 4 is made of ordinary glass or the like. An exposed electrode 5 is formed in advance around the inner surface of the drive substrate 3. Next, in step B, the planar connector member 2 is joined to the exposed electrode 5 which is provided in advance in a portion near the end surface 7 of the drive substrate 3. This joining process is performed by, for example, thermocompression bonding. Next, step C
At, the corner portion where the outer surface 8 of the drive substrate 3 and the end surface 7 intersect is processed to provide a grinding surface 9. This process is performed using, for example, a diamond file. Finally, process D
Then, the reinforcing resin 10 is continuously supplied over the ground surface 9, the end surface 7 of the substrate 3, and the upper surface 6 of the planar connector member.
In this example, an ultraviolet curable adhesive is used as the reinforcing resin 10 and is applied to a predetermined portion with a dispenser. After that, it is irradiated with ultraviolet rays to be cured.

[0014]

As described above, according to the present invention, a grinding surface is provided at the corner where the outer surface and the end surface of the liquid crystal panel substrate intersect, and the reinforcing resin extends to the grinding surface. Is being supplied. Therefore, the effect of increasing the bonding strength between the liquid crystal panel and the planar connector member can be obtained as compared with the conventional case. In particular, by newly exposing the ground surface, contaminants and the like remaining on the end surface of the substrate can be completely removed, and sufficient roughness can be secured because the roughness of the ground surface is rough. For this reason, the adhesive strength of the portion where the stress is most concentrated is increased, so that there is an effect that the peeling of the reinforcing resin that triggers the destruction of the joint can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a joint portion of the liquid crystal display device shown in FIG.

FIG. 3 is a process drawing showing the method of assembling the liquid crystal display device according to the present invention.

FIG. 4 is a schematic perspective view showing an example of a conventional liquid crystal panel.

FIG. 5 is a perspective view showing an example of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Planar connector member 3 Driving board 4 Counter substrate 5 Exposed electrode 6 One side of planar connector member 7 End surface 8 Outer surface 9 Grinding surface 10 Reinforcing resin 11 Joint part

Claims (2)

[Claims] 1. A panel in which a pair of substrates are adhered to each other and liquid crystal is held between the substrates and an exposed electrode formed on one of the substrates, and extend outward from an end face of the substrate. In a liquid crystal display device including a planar connector member, a grinding surface is provided at a corner where the surface and the end surface of the one substrate intersect, the grinding surface, the end surface, and one surface of the planar connector member. A liquid crystal display device characterized in that a reinforcing resin is provided over the entire area. 2. A step of adhering a pair of substrates to each other and enclosing a liquid crystal between them to form a panel, and a planar connector member on an exposed electrode provided in a portion close to an end face of one substrate. And a step of treating the corner where the surface of one of the substrates and the end face intersect to provide a ground surface, and a reinforcing resin over the ground surface, the end surface, and one surface of the planar connector member. And a step of supplying the liquid crystal display device.