JP3747269B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween, and a method of manufacturing the liquid crystal display device.
[0002]
[Prior art]
In general, a liquid crystal panel, which is a main component of a liquid crystal display device, is often manufactured from a large glass substrate by a multi-cavity technique. For example, Japanese Patent Laid-Open No. 54-157642 discloses an example of a method for manufacturing such a liquid crystal panel. In this type of manufacturing method, first, a pair of glass substrates having a large area are stacked and bonded to form a large glass substrate frame, and then a primary scribe process is performed using diamond or a super steel alloy. Cutting scratches are made at appropriate positions on both glass substrates, and the large area glass substrate frame is divided into several intermediate glass substrate frames with these scratches as a boundary. Then, liquid crystal is injected into each of the plurality of liquid crystal panels included in the intermediate glass substrate frame, and each injection port is sealed. Thereafter, a secondary scribing process is performed on each of the intermediate glass substrate frames to make cuts corresponding to the individual liquid crystal panels, and further, the intermediate glass substrate frame is cut using these scratches as a boundary. The individual LCD panels are divided.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional liquid crystal panel manufacturing method, when the glass substrate is cut from the cutting scratch formed by the primary scribe process and the secondary scribe process, a small chip is not formed on the end face of the cut glass substrate. Cracks, that is, cracks often occurred. If such a crack occurs on the end face of the substrate, there is a problem that when the liquid crystal panel is dropped, the liquid crystal panel surface cracks from the crack and the liquid crystal panel breaks. In particular, when a liquid crystal panel is used as an information display unit of a mobile phone, there is a high possibility that the mobile phone, and thus the liquid crystal panel, will drop, and therefore the liquid crystal panel is broken due to the drop.
[0004]
Although it is not known whether or not the purpose is to prevent the liquid crystal panel from cracking, according to Japanese Patent Laid-Open No. 5-281568, the outer edge portion of the liquid crystal panel and the circuit board provided at the outer edge portion are molded resin. A technique for protecting them by coating is disclosed.
[0005]
However, this publication does not specifically disclose how the mold resin is formed in relation to cracks generated on the end face of the liquid crystal substrate. In addition, in FIG. 3 of the same publication, it is judged from the idea that a mold case is created at an appropriate interval on the outer edge of the liquid crystal panel, and cracks existing on the end face of the liquid crystal substrate are broken. It can be easily understood that the mold resin is not formed for the purpose of preventing the development.
[0006]
The present invention has been made in view of the above prior art, and even when a large impact is applied to the liquid crystal display device due to dropping or other causes, the liquid crystal panel in the liquid crystal display device is reliably cracked. An object of the present invention is to provide a liquid crystal display device that can be prevented.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first liquid crystal display device according to the present invention is a liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween, and an input terminal pattern formed on the glass substrate. The side end surfaces of the pair of glass substrates including those other than the side end surfaces of the glass substrate adjacent to the input terminal pattern are subjected to a heat treatment for dissolving cracks generated on the side end surfaces. . The first method for manufacturing a liquid crystal display device according to the present invention is to manufacture a liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween and an input terminal pattern formed on the glass substrate. In the manufacturing method, the pair of glass substrates including a step of cutting a glass substrate having a large area to form a glass substrate constituting the liquid crystal display device, and other than a side end face of the glass substrate adjacent to the input terminal pattern And a substrate end face heat treatment step for dissolving cracks generated on the respective side end faces. As the heat treatment here, for example, laser light irradiation can be considered.
[0008]
According to this liquid crystal display device and its manufacturing method, even when a plurality of liquid crystal panels are indexed from a large glass substrate, even if cracks, that is, small chippings, occur on the side end surfaces of the glass substrates of the individual liquid crystal panels. By applying heat treatment to the side end face of the glass substrate using laser light or the like, the end face is melted and cracks are eliminated. As a result, it is possible to reliably prevent cracking of the liquid crystal panel, which has conventionally occurred when a large impact is applied to the liquid crystal panel due to dropping or the like, that is, a crack that is a starting point of the crack.
[0009]
A second liquid crystal display device according to the present invention is a liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween, and a protective member for covering cracks present on the side end surfaces of the pair of glass substrates. It is provided on the side end face. The second manufacturing method of the liquid crystal display device according to the present invention is a manufacturing method for manufacturing a liquid crystal display device having a pair of glass substrates opposed to each other with a liquid crystal interposed therebetween. The substrate is overhanging from the other, and has a substrate end surface processing step for providing a protective member for covering a crack existing on the side end surfaces of the pair of glass substrates on the side end surface including the overhanging region. And
[0010]
As said protection member, it can be set as resin for shaping | molding apply | coated to the area | region including the side end surface of a glass substrate, for example. As the molding resin, for example, an epoxy resin that is a thermosetting resin, an acrylic resin that is an ultraviolet (UV) curable resin, or the like can be used. A ceramic material can also be used as a protective member.
[0011]
According to the liquid crystal display device and the method of manufacturing the liquid crystal display device, even when cracks occur on the side end surfaces of the glass substrates of individual liquid crystal panels when a plurality of liquid crystal panels are indexed from a large glass substrate, those cracks are generated. Is filled with a protective member, for example, various resins or ceramic materials, and even if it is dropped, cracks can be prevented from growing and progressing to cracks.
[0012]
It is desirable that the protective member is applied substantially only to the side end surface of the glass substrate and not applied to the information display surface of the glass substrate. This is because if the information display surface is provided, the area of the information display surface is reduced. The term “substantially” means that the protective member partially and slightly protrudes from the information display surface due to work errors and the nature of the protective member.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 shows a liquid crystal panel which is a main component of a liquid crystal display device according to the present invention as set forth in claim 1 and one main process in manufacturing the liquid crystal panel. The liquid crystal panel 1 shown here has a pair of glass substrates 2 a and 2 b bonded to each other by a sealant 3. Liquid crystal 4 is sealed in a space formed between both glass substrates 2a and 2b, that is, a so-called cell gap. Transparent electrodes (not shown) having a stripe shape or an appropriate pattern are formed on the inner surfaces of the glass substrates 2a and 2b, that is, the opposing surfaces, and an input terminal pattern 5 leading to these electrodes is formed on the inner surface of one glass electrode 2b ( It is formed on the upper surface in the figure.
[0014]
A polarizing plate (not shown) is bonded to the outer surface of each of the glass substrates 2a and 2b of the liquid crystal panel 1, and heat seal or flexible printed circuit (FPC) equipped with a driving IC or the like is used as an adhesive, ACF (Anisotropic Conductive). The liquid crystal display device is manufactured by connecting to the input terminal pattern 5 by soldering or the like, and attaching a backlight, a reflector, and other accessory parts to one glass substrate. .
[0015]
The liquid crystal panel 1 is manufactured as shown in FIGS. 2 and 3, for example. That is, first, two glass substrates 2 c and 2 d having a large area are bonded to each other by the sealant 3. Then, a primary scribing process is performed using diamond or a super steel alloy to form primary cutting flaws 6a on the glass substrates 2c and 2d. Then, both glass substrates 2c and 2d are individually pressed by the pressing element 7 with a predetermined pressure, and the glass substrates 2c and 2d are cut from the cutting scratches 6a. A plurality of intermediate glass substrate frames 2e including five liquid crystal panels 1 in the case of the embodiment (five in the case of the present embodiment) are produced.
[0016]
Thereafter, the liquid crystal 4 is sealed in the cell gap G formed between the glass substrates 2c and 2d for each of the produced intermediate glass substrate frames 2e. After that, a secondary scribing process is performed using diamond or a super steel alloy, and a cutting flaw 6b is formed at a planned cutting position corresponding to the size of one liquid crystal panel with respect to each intermediate glass substrate frame 2e. Further, the glass substrates 2c and 2d are individually pressed with a predetermined pressure by the presser 7, and the intermediate glass substrate frame 2e is cut from the scratch 6b to divide the liquid crystal panel 1 one by one.
[0017]
By the way, when the individual liquid crystal panels 1 are indexed from the large glass substrates 2c and 2d as described above, the cut surfaces of the glass substrates 2a and 2b of the liquid crystal panel 1, that is, the side end surfaces of the glass substrates 2a and 2b, respectively. Cracks may occur. If such cracks occur on the side end surfaces of the glass substrates 2a and 2b of the liquid crystal panel 1, and the cracks remain in the liquid crystal display device as the final product without being repaired, the cracks may fall on the liquid crystal display device. When a large impact is applied, the glass substrate may be cracked starting from the crack, making it impossible to use as a liquid crystal display device.
[0018]
With respect to the liquid crystal panel 1 of the present embodiment, in order to prevent the glass substrate from cracking due to cracks existing on the glass end face, when a crack occurs on the end face of the glass substrate, as shown in FIG. After the indexing and before mounting the polarizing plate (not shown), the glass substrate end surface is irradiated with laser light R from the laser irradiation system 8 to melt the glass substrate end surface by heat generation, thereby cracking. Annihilate. Thereby, a liquid crystal panel and a liquid crystal display device with high impact resistance can be manufactured.
[0019]
The laser light R may be applied uniformly to all side end faces of the glass substrates 2a and 2b, or side end faces that are considered to be easily shocked in view of the use form of electronic equipment using the liquid crystal panel 1. May be selected and the laser light R may be irradiated only on the side end face.
[0020]
In this embodiment, the laser irradiation system 8 includes a laser oscillator 9 that generates laser light, a lens system 11 that enlarges or reduces the cross-sectional diameter of the laser light as necessary, and a mirror 12 that reflects the laser light. Composed. By adjusting the angle of the mirror 12 as appropriate, it is possible to irradiate laser light to any desired position of the glass substrates 2a and 2b. In some cases, the entire surface of the side end surfaces of the glass substrates 2a and 2b can be irradiated with laser light by moving the mirror 12 in a continuous rotational scanning manner.
[0021]
(Second Embodiment)
In the embodiment described above, after the individual liquid crystal panels 1 are divided from the large glass substrates 2c and 2d, laser light is applied to the end faces of the individual liquid crystal panels 1 as shown in FIG. Irradiation eliminated the cracks. However, instead of such a method, in FIG. 3, after producing some intermediate glass substrate frames 2e by performing a primary scribe process, liquid crystal is injected into these glass substrate frames. Prior to this, a laser beam can be applied to the divided section of each intermediate glass substrate frame 2e to eliminate the cracks generated in the divided section.
[0022]
Then, after the laser treatment, liquid crystal is injected into each intermediate glass substrate frame 2e, each injection port is further sealed, and further, a secondary scribe process is performed to produce final individual liquid crystal panels 1. Thereafter, the laser beam is irradiated to the divided sections of the glass substrates 2a and 2b formed by the secondary scribe process, and the cracks in the divided sections can be eliminated.
[0023]
In this way, before the liquid crystal panels 1 are completely divided one by one, if the liquid crystal panels 1 are still connected to each other, and laser irradiation is performed on those divided sections, the work efficiency is improved. Will improve.
[0024]
(Third embodiment)
FIG. 4 shows a liquid crystal panel which is a main component of the liquid crystal display device according to the third aspect of the present invention and one process for manufacturing the liquid crystal panel. Since the liquid crystal panel 1 shown in this figure is the same as the liquid crystal panel 1 shown in FIG. 1, the description thereof is omitted. As described with reference to FIG. 1, cracks may occur on the side end surfaces of the glass substrates 2 a and 2 b of the liquid crystal panel 1. In the present embodiment, in order to repair the crack, the tube 13 is squeezed along the glass substrates 2a and 2b as indicated by an arrow A while the molding resin J is squeezed out from the tube 13 containing the molding resin as a protective member. The resin J is applied to the entire side end surfaces of the glass substrates 2a and 2b by being translated.
[0025]
If the molding resin J is a thermosetting resin, for example, an epoxy resin, the resin applied to the end surface on the substrate side is cured by heating. Further, if the molding resin J is an ultraviolet (UV) curable resin, for example, an acrylic resin, after the application is completed, the applied resin is irradiated with ultraviolet rays to be cured. As shown in FIG. 5, the resin J is preferably applied to the entire side end surfaces of the glass substrates 2a and 2b except for the side end surfaces where the input terminal patterns 5 are formed. Resin J may be applied to the side end faces of the glass substrates 2a and 2b where the input terminal pattern 5 is to be formed. However, the side end faces are reinforced as a result of connecting a heat seal or the like to the part. In many cases, there is no problem even if the resin J is not applied. Further, as shown in FIG. 6, it is desirable that the molding resin J is applied only to the end surfaces of the glass substrates 2a and 2b and does not protrude from the information display surface 14a or 14b of the glass substrates 2a or 2b. This is because the information display area is narrowed so as to protrude, so that it can be avoided and the entire surface of the liquid crystal panel 1 can be used effectively.
[0026]
(Other embodiments)
As mentioned above, although this invention was demonstrated using preferable embodiment, this invention is not limited to those embodiment, It can change variously within the technical scope described in the claim.
[0027]
For example, the liquid crystal panel to which the present invention can be applied is not limited to the liquid crystal panel having the structure shown in FIGS. 1 and 4, and can be applied to a liquid crystal panel having an arbitrary structure in which a crack may occur on the side end surface of the glass substrate. In FIG. 1, the laser irradiation system 8 can have an arbitrary configuration other than that illustrated. In the embodiment shown in FIG. 3, the case where 5 × 5 = 25 liquid crystal panels 1 are taken out from one large glass substrate 2c and 2d is taken as an example, but how many liquid crystal panels are taken out. You can decide freely.
[0028]
【The invention's effect】
According to the liquid crystal display device according to claim 1 and the method for manufacturing the liquid crystal display device according to claim 6, it is possible to eliminate the cracks generated on the side end face of the glass substrate. It is possible to reliably prevent the liquid crystal panel from being cracked due to the crack when subjected to an impact.
[0029]
According to the liquid crystal display device of the second aspect, fine cracks, cracks with complicated shapes, and the like can be surely eliminated by simple operations.
[0030]
According to the liquid crystal display device according to claim 3 and the manufacturing method of the liquid crystal display device according to claim 7, since the crack generated on the side end surface of the glass substrate is covered and reinforced by the protective member, the liquid crystal panel is conventionally used. It is possible to reliably prevent the liquid crystal panel from being cracked due to the crack when subjected to an impact.
[0031]
According to the liquid crystal display device of the fourth aspect, the side end surface of the liquid crystal panel can be reliably reinforced and the information display surface of the liquid crystal panel can be effectively utilized.
[0032]
According to the liquid crystal display device of the fifth aspect, the protective member can be formed by a simple and reliable method.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a liquid crystal panel that is a component of a liquid crystal display device according to the present invention and a process of a manufacturing method for manufacturing the liquid crystal panel.
FIG. 2 is a cross-sectional view showing an example of a manufacturing method for manufacturing the liquid crystal panel shown in FIG.
FIG. 3 is a plan view showing a large glass substrate before being cut.
FIG. 4 is a perspective view showing an embodiment of a liquid crystal panel which is a component of a liquid crystal display device according to the present invention and one step of a manufacturing method for manufacturing the liquid crystal panel.
5 is a plan view of the liquid crystal panel of FIG. 4. FIG.
6 is a cross-sectional view showing a cross-sectional structure of a liquid crystal panel according to the line BB in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2a, 2b Glass substrate 2c, 2d Large glass substrate 2e before a cutting | disconnection Intermediate glass substrate frame 3 formed by a primary scribing process 3 Sealant 4 Liquid crystal 5 Input terminal pattern 6 Cutting flaw 7 Presser 8 Laser irradiation System 9 Laser oscillator 11 Lens system 12 Mirror 13 Resin tubes 14a and 14b Information display surface of liquid crystal panel

Claims (1)

In a manufacturing method for manufacturing a liquid crystal display device having a pair of glass substrates facing each other across the liquid crystal and an input terminal pattern formed on the glass substrate,
Each side of the pair of glass substrates including a step of cutting the glass substrate having a large area to form the glass substrate constituting the liquid crystal display device, and other than a side end face of the glass substrate adjacent to the input terminal pattern And a substrate end face heat treatment step for dissolving cracks generated on the end face.

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