JP2001100164A - Liquid crystal panel, its production and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily inspect the appearance of a panel because the form of a sealing agent on an opening after applied is important to completely seal a liquid crystal in the panel. SOLUTION: The method of producing a liquid crystal panel 5 includes an assembling process to assemble a panel having an inner flat space and an opening 4 connecting the flat space to the outside, a process to inject a liquid crystal from the outside through the opening 4 into the inner flat space, a sealing process to supply a sealing agent 6 consisting of a hardening resin on the opening 4 to close the opening 4 and to seal the liquid crystal, and an inspection process to inspect the supplied state of the hardening resin to the opening 4 from the appearance. In the sealing process, an opaque hardening resin having <=50%/mm transmittance for light is used so as to make the succeeding inspection process easy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel, a method of manufacturing the same, and a method of inspecting the same. More specifically, the present invention relates to a visual inspection technique for a curable resin used for sealing an opening after injecting liquid crystal from an opening formed in an empty panel.

[0002]

2. Description of the Related Art FIG. 5 is a schematic sectional view showing an example of a conventional liquid crystal panel. As shown, the liquid crystal panel 5
Has a structure in which a pair of glass substrates 1 and glass substrates 2 on which electrodes and an alignment film (not shown) are formed in advance are bonded with a sealing material 3. In order to keep the gap between the two substrates 1 and 2 constant, spacers 7 are sprayed on the surface of one substrate before bonding. A part of the sealing material 3 is cut out in a plan view to form an opening. The liquid crystal 8 is applied to the substrate 1 through the opening.
2 and sealed with a sealant 6. The sealant 6 is made of a curable resin. As described above, the liquid crystal panel 5 is assembled through the assembling process of assembling a panel having an inner flat space surrounded by the pair of glass substrates 1 and 2 and an opening communicating from the flat space to the outside. It is manufactured by a process of injecting the liquid crystal 8 from the outside into the inside flat space, and a sealing process of supplying an agent 6 made of a curable resin to the opening to seal the opening and seal the liquid crystal.

[0003]

Among the above-described steps, the step of applying the sealing agent 6 has a great effect on the reliability of the liquid crystal panel 5. Therefore, the sealant 6 for the liquid crystal panel is used.
The development of materials has been promoted in order to meet requirements such as not adversely affecting the liquid crystal 8, high bonding strength after sealing, good moisture resistance, and heat resistance. or,
Since the liquid crystal 8 is completely sealed in the panel, the shape of the opening after the application of the sealant 6 is important, so that the viscosity of the sealant 6 can be optimally controlled and a dispenser capable of precise application. Has also been developed. However, it has not been sufficiently studied from the viewpoint of facilitating the appearance inspection of the shape of the sealant 6 after application. Conventionally, the sealant 6 is generally made of a transparent curable resin, and there has been little difference in brightness or color tone between the sealant and a transparent substrate such as a glass plate or a plastic plate. For this reason, it is difficult to inspect the appearance of the sealant after application, which not only reduces the work efficiency of the inspection but also causes a defective product to be overlooked. Also, in order to automate the sealing process, it is desired to replace the visual inspection of the shape of the sealant, which had been manually performed, with an automatic inspection combining a video camera and a computer. Since there is little difference in brightness or color tone between the substrate and the encapsulant, image recognition is difficult and full automation has not been achieved.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems of the prior art, the following measures have been taken. That is, an assembling step of assembling a panel having an internal flat space and an opening communicating with the outside from the flat space, a step of injecting liquid crystal from the outside into the internal flat space through the opening, and sealing the opening. A method of manufacturing a liquid crystal panel, comprising: a sealing step of supplying a curable resin to the opening to stop and seal the liquid crystal; and an inspection step of visually inspecting a supply state of the curable resin to the opening. In the sealing step, an opaque curable resin having a light transmittance of 50% / mm or less is used in order to facilitate a subsequent inspection step. Preferably, the sealing step uses a colored curable resin. Further, in the sealing step, the curable resin is supplied to an opening formed in a portion where the sealing material is lost on an end face of a panel made of a pair of glass substrates joined to each other by a sealing material.
In the inspection step, the image of the opaque curable resin captured by the camera is recognized and processed by a computer, and the supply state of the curable resin to the opening is inspected.

[0005] The present invention includes a method for inspecting a liquid crystal panel. That is, assembling a panel having an inner flat space and an opening communicating with the outside from the flat space, injecting liquid crystal from the outside into the inner flat space through the opening, and supplying a curable resin to the opening. A method for inspecting a liquid crystal panel in which the opening is sealed, wherein when the supply state of the curable resin to the opening is visually inspected, an opaque curable resin having a light transmittance of 50% / mm or less is used in advance. It is characterized in that the inspection is facilitated by using it.

Further, the present invention includes the structure of the liquid crystal panel itself. That is, an internal flat space and an opening communicating from the flat space to the outside, a liquid crystal injected into the internal flat space from the outside through the opening, and a curable resin sealing the opening. , The curable resin is an opaque curable resin having a light transmittance of 50% / mm or less.

According to the present invention, in order to improve the workability of the appearance inspection of the applied state of the sealant in the step of sealing the opening for injecting the liquid crystal into the flat space of the panel, it is opaque and excellent in visibility. The curable resin composition is used as a sealant for the injection opening. Because there is a remarkable difference in lightness or color between the substrate made of glass and the sealant, not only the visual appearance inspection is made easy, but also the visual inspection using a video camera and a computer is automated. Will be possible.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic view illustrating an example of a method for manufacturing a liquid crystal panel according to the present invention. First, as shown in (A), two transparent substrates 1 and 2 made of glass or the like are used.
Are formed on each of them, for example, a transparent electrode made of ITO or the like, and an alignment film made of polyimide or the like is formed thereon. Thereafter, a sealing material 3 is applied to the surface of one glass substrate 1 by screen printing or the like. The sealing material 3 is, for example, a material obtained by filling a filler in an ultraviolet curable or thermosetting resin. At this time, an opening 4 for injecting a liquid crystal in a later step is provided so as to cut out a part of the sealing material 3. The two transparent substrates 1 and 2 are arranged in parallel so that the surfaces on which the alignment films are formed are on the inside, and a spacer (not shown) is sprayed on at least one of the substrates. To bond the two substrates 1 and 2 together. In this state, by curing the sealing material 3, the two substrates 1 and 2 are joined to each other, and a flat space is formed inside.

Subsequently, as shown in FIG. 2B, after the flat internal space of the pair of glass substrates 1 and 2 joined to each other is evacuated, the liquid crystal is pressured into the internal flat space through an opening communicating with the outside. Add and inject. Thereby, the liquid crystal is filled in the flat space inside, and the liquid crystal panel 5 is completed. Then, after wiping off excess liquid crystal attached to the opening, a sealant 6 is applied. As a feature of the present invention, this sealant 6
Uses an opaque curable resin having a light transmittance of 50% / mm or less. In some cases, the opaque curable resin may be colored by adding a dye or pigment. After the application of the sealant 6, the application state is inspected visually or by image recognition using a camera. If an abnormality is found in the application state and the opening is not sufficiently sealed, correction is made before the curing process. At the stage when the appearance inspection is completed, the sealing agent 6 is cured, and the sealing of the liquid crystal panel 5 is completed. The main component of the sealant 6 can be an acrylic ultraviolet curing resin or an epoxy thermosetting resin. However, the present invention is not limited to these materials. In order to make the sealant 6 opaque, it is effective to add an inorganic filler such as titanium oxide, alumina, and silica, a pigment, and a light scattering agent. Although the optimum amount of addition varies depending on the size and shape of the particles, the light transmittance of the sealant 6 can be controlled within 50% / mm by adding the additive.

FIG. 2 is a schematic block diagram showing an example of an automatic appearance inspection apparatus used for automatic appearance inspection of the sealant of the liquid crystal panel shown in FIG. This inspection device basically includes a camera 14 and a computer 15. The camera 14 is mounted above the stage 12 via a post 14A. On the stage 12, a liquid crystal panel 5 stored in a transport tray 13 is placed. The end face of the liquid crystal panel 5 is in a state where the sealing agent is applied. Tray 13
Moves sequentially below the camera 14 while being mounted on the stage 12. In synchronization with this, the camera 14 captures an image of the application state of the sealant on each liquid crystal panel 5 and sends the obtained image data to the computer 15. Computer 1
Numeral 5 analyzes the image data and compares it with a predetermined criterion to determine the quality of each liquid crystal panel 5. Stage 1
2, the camera 14 and the computer 15
6.

FIG. 3 is a table showing the results of visual inspection and automatic inspection performed while changing the light transmittance of the sealant. The sealant was based on an ultraviolet-curable acrylic resin, and titanium oxide fine particles were dispersed to adjust the transmittance. Sealant 1
The content of titanium oxide is controlled such that its light transmittance becomes 95% / mm. Since the sealant 1 is almost transparent, visual inspection is difficult, and image recognition using a camera is impossible. Sealant 2 has a light transmittance of 60% / m
Although the content of titanium oxide was increased so as to be m, visual inspection was still somewhat difficult, and image recognition by a camera was impossible. The sealing agent 3 is further adjusted so that the light transmittance becomes 50% / mm by further increasing the content of titanium oxide. This sealant 3 is considerably opaque, which facilitates visual inspection and image recognition using a camera. Further, the sealing agent 4 has a light transmittance adjusted to 30% / mm by increasing the content of titanium oxide. Not only becomes more opaque, visual inspection becomes easier, but also image recognition using a camera is possible.

FIG. 4 is a reference diagram showing an example of the actual configuration of a liquid crystal panel manufactured according to the present invention. This example has a configuration of a so-called active matrix type liquid crystal panel. However, for ease of illustration, a sealant and a sealant for bonding a pair of substrates are not illustrated. As shown, the liquid crystal panel includes a substrate 1 serving as a base, a substrate 2 facing the substrate 1, and an electro-optical material held between the two. Substrates 1 and 2 are made of glass or plastic.
Liquid crystal 8 is used as an electro-optical material. The lower substrate 1 serving as a base is provided with a pixel array unit 1 using a semiconductor technology.
04 and a drive circuit unit are formed integrally. The drive circuit section is divided into a vertical drive circuit 105 and a horizontal drive circuit 106. A terminal 107 for external connection is formed at the upper end of the peripheral portion of the substrate 1. The terminal 107 is a wiring 108
Are connected to the vertical drive circuit 105 and the horizontal drive circuit 106 via the. A row-shaped gate wiring 109 and a column-shaped signal wiring 110 are formed in the pixel array unit 104. A pixel electrode 111 and a thin film transistor 112 for driving the pixel electrode 111 are formed at the intersection of the two wirings, and constitute a pixel.

[0013]

As described above, according to the present invention,
To assemble a panel having an inner flat space and an opening communicating with the outside, to inject liquid crystal from the outside into the inner flat space through the opening, and to seal the opening to seal the liquid crystal In a method of manufacturing a liquid crystal panel including a sealing step of supplying a curable resin to the opening and an inspection step of visually inspecting a supply state of the curable resin to the opening,
The sealing process has a light transmittance of 5 to facilitate the subsequent inspection process.
An opaque curable resin of 0% / mm or less is used. As described above, by setting the light transmittance of the sealing agent to 50% / mm or less, the contrast with the transparent substrate was improved, and the inspection after injection sealing was facilitated. As a result, defects in the sealing step can be reliably found, and by performing correction before curing, the yield is improved and the cost is reduced. Further, image recognition by a camera became possible, and the inspection time was shortened by automating the inspection, thereby improving the productivity. Furthermore, cost reduction was achieved by reducing the number of inspection personnel.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a method for manufacturing a liquid crystal panel according to the present invention.

FIG. 2 is a schematic view showing an automatic inspection apparatus used for inspecting a liquid crystal panel according to the present invention.

FIG. 3 is a table showing the effects of the present invention.

FIG. 4 is a reference diagram showing an example of a liquid crystal panel manufactured according to the present invention.

FIG. 5 is a cross-sectional view illustrating an example of a conventional liquid crystal panel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Glass substrate, 3 ... Sealing material, 4 ... Opening, 5 ... Liquid crystal panel, 6 ...
Sealant, 7: spacer, 8: liquid crystal, 12:
Stage, 13 ... tray, 14 ... camera, 15
... Computer, 16 ... Electrical box

Claims (12)

[Claims] An assembling step of assembling a panel having an inner flat space and an opening communicating from the flat space to the outside; a step of injecting liquid crystal from the outside into the inner flat space through the opening; A liquid crystal panel including a sealing step of supplying a curable resin to the opening to seal the liquid crystal by sealing the opening, and an inspection step of visually inspecting a supply state of the curable resin to the opening. The method of manufacturing a liquid crystal panel according to claim 1, wherein the sealing step uses an opaque curable resin having a light transmittance of 50% / mm or less in order to facilitate a subsequent inspection step. 2. The method according to claim 1, wherein the sealing step uses a colored curable resin. 3. The sealing step includes supplying the curable resin to an opening formed in a portion of the panel made of a pair of glass substrates joined to each other by a seal material, where the seal material is missing. 2. The method for manufacturing a liquid crystal panel according to claim 1, wherein: 4. In the inspection step, an image of the opaque curable resin captured by a camera is recognized and processed by a computer.
2. The method according to claim 1, wherein the supply state of the curable resin to the opening is inspected. 5. A panel having an internal flat space and an opening communicating from the flat space to the outside is assembled, and liquid crystal is injected from the outside into the internal flat space through the opening, and a curable resin is injected into the opening. A method for inspecting a liquid crystal panel in which the opening is supplied and the opening is sealed, wherein when the supply state of the curable resin to the opening is visually inspected, an opaque cured material having a light transmittance of 50% / mm or less in advance. A method for inspecting a liquid crystal panel, wherein the inspection is facilitated by using a conductive resin. 6. The method for inspecting a liquid crystal panel according to claim 5, wherein a colored curable resin is used for sealing, and a supply state is visually inspected. 7. An external appearance inspection of a curable resin supplied to an opening formed in a portion where the sealing material is defective on an end face of a panel made of a pair of glass substrates joined to each other by a sealing material. The method for inspecting a liquid crystal panel according to claim 5, wherein: 8. An opaque curable resin image picked up by a camera is recognized and processed by a computer to check a supply state of the curable resin to the opening.
Inspection method of the liquid crystal panel described. 9. An internal flat space, and an opening communicating from the flat space to the outside, a liquid crystal injected into the internal flat space from the outside through the opening, and a hardening sealing the opening. A curable resin, wherein the curable resin is an opaque curable resin having a light transmittance of 50% / mm or less. 10. The liquid crystal panel according to claim 9, wherein said opaque curable resin is colored. 11. The method according to claim 9, wherein the curable resin seals an opening formed in a portion where the sealing material is lost at end surfaces of a pair of glass substrates joined to each other by a sealing material. LCD panel. 12. The liquid crystal panel according to claim 9, wherein the image of the opaque curable resin is captured by a camera and can be recognized by a computer.