JP4151689B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

  The present invention relates to a method for manufacturing a liquid crystal display device and a liquid crystal display device. The present invention relates to a manufacturing method of a liquid crystal display device for manufacturing the device and a liquid crystal display device on which a confirmation mark is formed.

For example, a method described in Japanese Patent Laid-Open No. 6-186515 is conventionally known as a method of manufacturing a liquid crystal display device that forms a positioning mark for a sealing agent. In this method of manufacturing a liquid crystal display device, before the step of printing the sealing agent, a positioning mark is formed on at least a part of the sealing position on the glass substrate where the sealing agent is to be printed. The sealant is printed after the positioning of the mask for printing the agent. In this case, in the sealing agent printing step, generally, the sealing agent is rubbed at a predetermined pressure using a spatula-shaped squeegee after the sealing agent is deposited on the aligned sealing agent printing mask. Is printed on a glass substrate with a predetermined thickness. Next, the glass substrate on which the sealing agent is printed and the other glass substrate are brought into close contact with each other, and in this state, the sealing agent is cured by irradiating ultraviolet rays to bond the two glass substrates together. Thereafter, the air in the space between the two substrates is evacuated through the liquid crystal filling port to be in a vacuum state, and the space is filled with liquid crystal while maintaining this state. Next, the both glass substrates are cut into a predetermined size to complete the liquid crystal display device.

  However, this conventional method for manufacturing a liquid crystal display device has the following problems.

  That is, the positioning mark used in the conventional method for manufacturing a liquid crystal display device only functions as a reference for positioning one end of the seal width on which the sealant is to be printed. It does not work to print to the width. That is, the actual seal width after printing the sealant depends on the viscosity of the sealant and the pressure of the squeegee. Therefore, even if the positioning mark is formed, when the viscosity of the sealant is high or when the pressure of the squeegee is low, the sealant is printed on the glass substrate with less than the appropriate amount through the mask, When the viscosity of the sealant is low or when the pressure of the squeegee is high, the sealant is printed on the glass substrate more than the appropriate amount. Further, the seal width in a state where both glass substrates are bonded is generally about two to three times larger than the seal width at the time of printing, but the extent of this expansion also depends on the viscosity of the sealant.

  In this case, if the sealant is printed in a small amount, the seal may be broken. In such a state, the liquid crystal leaks or the air cannot be sufficiently exhausted, so that a predetermined amount of liquid crystal cannot be filled. In addition, when the amount of the sealing agent is small, the shielding property between the space portion of the glass substrate and the outside air is lowered, so that the display quality is deteriorated due to the moisture in the outside air entering the liquid crystal, or the glass substrate is bonded The glass substrate may be peeled off due to a decrease in strength.

  On the other hand, if the sealing agent spreads to the cutting part of the glass substrate by printing a large amount of the sealing agent, it becomes difficult to cut the glass substrate. A situation occurs in which cutting with high accuracy is impossible. In addition, for example, when a black part is provided as a display frame of a glass substrate, the sealing agent may not be cured even when irradiated with infrared rays. In such a case, the sealing agent leaks into the liquid crystal. Display quality may be degraded.

  For this reason, in the conventional method of manufacturing a liquid crystal display device, even if the positioning mark for the sealant is formed, this is not sufficient. In addition, the viscosity of the sealant is controlled and the squeegee pressure is controlled. At present, the amount of sealing agent printed on the glass substrate is adjusted by sufficiently performing control and the like. Therefore, when the viscosity of the sealant and the squeegee pressure are not sufficiently controlled in the conventional method for manufacturing a liquid crystal display device, an appropriate amount of the sealant cannot be printed, resulting in a decrease in the yield of the liquid crystal display device. There is a problem of letting it.

  The present invention has been made to solve the above problems, and provides a method for manufacturing a liquid crystal display device and a liquid crystal display device capable of managing the coating amount of a sealant in the manufacturing process of the liquid crystal display device to an appropriate amount. The main purpose is to provide.

In order to achieve the above object, a method for manufacturing a liquid crystal display device according to the present invention is a method for manufacturing a liquid crystal display device in which a pair of substrates are bonded to each other with a sealant. Forming a first seal width confirmation mark and a pair of second seal width confirmation marks spaced apart from each other, and forming the first seal width confirmation mark along the four sides of the one substrate A step of applying the sealant between the pair of second seal width confirmation marks, a width of the sealant after application, and a width of the first seal width confirmation mark while overlapping and confirming Confirming step, adhering the one substrate and the other of the pair of substrates, confirming the width of the sealant after adhering the pair of substrates, and confirming the second seal width Check mark separation length A second confirmation step, wherein the first seal width confirmation mark is formed at a corner of the one substrate, and the second seal width confirmation mark is formed on four sides of the one substrate. It is characterized by being formed along any one side .
Further, the first and second seal width confirmation marks are each formed of a light shielding material.
In the first and second confirmation steps, the first and second seal width confirmation mark widths and the width of the sealant are confirmed through fluoroscopy, respectively.
The first seal width confirmation mark may be formed to have the same width as the sealant after application.
Further, the second seal width confirmation mark is formed so that a separation length thereof is the same as a seal width after bonding the pair of substrates.

  In this method of manufacturing a liquid crystal display device, immediately after performing the sealant application process, the sealant application amount is confirmed by checking the seal width of the applied sealant using the post-application seal width confirmation mark. It becomes possible to do. For this reason, for example, it becomes possible to feed back the confirmation result to the pressure management of the squeegee.

The manufacturing method of the liquid crystal display device according to the reference invention of the present invention includes a sealing agent application step of applying a sealing agent to at least one of a pair of glass substrates, and an adhesion step of bonding the pair of glass substrates to each other via the sealing agent. And a liquid crystal filling process for sequentially filling a liquid crystal between a pair of glass substrates, in order to confirm the seal width of the sealant after the adhesion process before the sealant application process A post-bonding seal width confirmation mark may be formed on at least one glass substrate.

  By confirming the seal width of the sealant after application using the post-application confirmation mark, it is possible to confirm the application amount of the sealant before bonding the pair of glass substrates. On the other hand, the seal width after bonding depends on the viscosity of the sealant. Therefore, even if the seal width after application is constant, the seal width after bonding is naturally different if the viscosity is different. In this method for manufacturing a liquid crystal display device, it is possible to confirm the seal width after bonding a pair of glass substrates by using the post-bonding seal width confirmation mark. For this reason, for example, the confirmation result can be fed back to the viscosity management of the sealant.

The manufacturing method of the liquid crystal display device according to the reference invention of the present invention includes a sealing agent application step of applying a sealing agent to at least one of a pair of glass substrates, and an adhesion step of bonding the pair of glass substrates to each other via the sealing agent. And a liquid crystal filling process for sequentially filling a liquid crystal between a pair of glass substrates, a seal width of the sealant after the sealant application process is confirmed before the sealant application process A post-application seal width confirmation mark and a post-adhesion seal width confirmation mark for confirming the seal width after the adhesion step may be formed on at least one glass substrate.

In the manufacturing method of the liquid crystal display device according to the reference invention of the present application, the post-application seal width confirmation mark may be formed at a substantially central position of a predetermined seal width.

In the manufacturing method of the liquid crystal display device according to the reference invention of the present invention, either one or both of the confirmation marks may be formed in at least two corners of the glass substrate.

In the method for manufacturing a liquid crystal display device according to the present invention, either one or both of the confirmation marks may be formed in a key shape or an arc shape.

In the method for manufacturing a liquid crystal display device according to the present invention, either one or both of the confirmation marks may be formed using a light-shielding material.

In the manufacturing method of the liquid crystal display device according to the reference invention of the present invention, either or both of the confirmation marks may be formed using any one of tantalum, ITO, chromium, aluminum, and a color filter material.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a method for manufacturing a liquid crystal display device and a liquid crystal display device according to the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, a liquid crystal display device 1 according to this embodiment includes a transparent glass substrate 2 on which MIM (Metal Insulator Metal) is formed, and a glass substrate 31 on which color filters are formed (FIG. 6 (a)). Are bonded to each other via a sealant 5. At the four corners of the glass substrate 2, a key-shaped mark (corresponding to the post-application seal width confirmation mark in the present invention) 3, 3,. Rectangular marks (corresponding to the post-adhesion seal width confirmation marks in the present invention) 4, 4... For confirming the seal width of the sealant 5 after the substrates 2 and 31 are adhered are, for example, tantalum or the like Each is formed using a light shielding material. In the figure, the seal width of the sealant 5 after bonding both the glass substrates 2 and 31 is indicated by a broken line, and the sealant 5 is not particularly limited, but an epoxy resin is used. Further, the sealant 5 is applied along the periphery of the glass substrate 2, but the portion not applied on the left side of the figure functions as a liquid crystal filling port 6 when filling the liquid crystal.

  In this liquid crystal display device 1, when the sealing agent 5 is applied through a mask in which a cutout hole corresponding to the application position of the sealing agent 5 is formed, the viscosity of the sealing agent 5 and the pressure of the squeegee are normally managed. In FIG. 2, the sealant 5 is applied on the same straight line as the mark 3 as shown in FIG. In this case, since the mark 3 is formed at the center position of the seal width of the sealant 5 defined in advance with the same width as the seal width, the seal width of the sealant 5 is the mark of the mark 3 after application of the sealant 5. It can be easily confirmed by fluoroscopy whether or not it is applied on the same straight line as the width. Further, after the substrates 2 and 31 are bonded to each other, the seal width of the sealant 5 is the same as the separation length of the marks 4 and 4, and the long sides on the opposite sides of the marks 4 and 4 Similarly, it can be easily confirmed by fluoroscopy whether the coating is applied to the extended line segments.

  The shapes and positions of the marks 3 and 4 are not limited to the example shown in FIG. 1 and can be formed in various shapes. For example, the marks 3 and 4 may be formed by broken lines, or, as shown in FIG. May be formed respectively. The mark 7 corresponds to the mark 3 and the mark 8 corresponds to the mark 4. When all the marks 7, 8, 8 are thus formed at the corners of the glass substrate 2, there is no risk of contact with an electrode such as an ITO film formed on the glass substrate 2. The surface area of the glass substrate 2 can be used effectively.

  Furthermore, the mark for confirming the seal width of the sealant 5 after bonding is not limited as long as the seal width of the sealant 5 can be confirmed. As shown in FIG. , 9... In this case, the seal width of the sealant 5 after bonding can be measured with high accuracy without depending on the feeling of the inspector. Further, instead of the mark 9, as shown in FIG. 5B, rectangular marks 10, 10,... With very short sides can be used. Also in this case, the seal width can be confirmed with high accuracy.

  Next, a manufacturing process of the liquid crystal display device 1 will be described with reference to FIGS.

  Initially, the manufacturing process of the glass substrate 2 is demonstrated with reference to FIG. First, as shown in FIG. 2A, for example, a tantalum film 22 is formed on a glass plate 21 that is a base of the glass substrate 2. Next, a resist 23 is applied on the tantalum film 22 as shown in FIG. Next, the resist 23 is exposed to a positive type by irradiating light from the direction indicated by the arrow in FIG. Thereafter, by developing the glass substrate 2, as shown in FIG. 4D, the portions of the resist 25, 25 that are shielded from light by the photomask 24 are left behind. Next, etching is performed to remove the unnecessary portion of the tantalum film 22 while leaving the tantalum film 22 corresponding to the remaining portions of the resists 25 and 25 as shown in FIG. Next, by removing the resists 25 and 25, the glass substrate 2 on which the MIM pattern 26 and the pattern 27 corresponding to the mark 3 and the mark 4 are formed is completed. In this case, since the material of the pattern 27 is a material for forming the glass substrate 2, the number of processes is not increased at all. Therefore, the marks 3 and 4 can be formed without increasing the manufacturing cost of the liquid crystal display device 1.

  Next, a manufacturing process of the liquid crystal display device 1 using the glass substrates 2 and 31 will be described with reference to FIG. First, as shown in FIG. 2A, a coating process for forming an alignment film 32 on the glass substrate 2 on which the MIM pattern 26 and the marks 3 and 4 are formed and the glass substrate 31 on which the color filter is formed is performed. Do. Next, as shown in FIG. 2B, rubbing is performed by rubbing the alignment film 32 using a roller 33. Next, as shown in FIG. 2C, the sealant 5 is applied using a squeegee and a mask not shown. When the application process of the sealant 5 is completed, it is confirmed by fluoroscopy whether the seal width of the sealant 5 matches the mark width of the mark 3. At this time, if the seal width is too thick or too thin, the sealing agent 5 is applied again after the sealing agent 5 is peeled off.

  Next, as shown in FIG. 4D, spacers 34 formed of plastic balls or glass balls are sprayed. Next, as shown in FIG. 5E, after the glass substrate 2 and the glass substrate 31 are overlaid, both glass substrates are pressed by pressing from above the glass substrate 31 as shown in FIG. 2 and 31 are bonded. Thereafter, it is confirmed by fluoroscopy whether the sealant 5 is applied to the line segments extending the long sides of the marks 4 and 4 facing each other. If the sealing agent 5 is not applied in an appropriate amount at this time, the glass substrates 2 and 31 are reused or discarded without performing a subsequent process. Thereby, the manufacturing cost required for a subsequent process can be reduced.

  Next, as shown in FIG. 6G, after the liquid crystal 35 is filled through the liquid crystal filling port 6, the liquid crystal filling port 6 is sealed with a sealing agent 36 as shown in FIG. . Next, as shown in FIG. 6I, isotropic treatment is performed to make the orientation of the liquid crystal 36 uniform by heating. Thereafter, as shown in FIG. 3J, the liquid crystal display device 1 is completed by cutting into a predetermined size.

  Thus, according to the liquid crystal display device 1 according to this embodiment, the seal width after applying the sealing agent 5 is confirmed using the mark 3, and the sealing agent 5 after the bonding of the glass substrates 2 and 31 is confirmed. By confirming the seal width using the marks 4 and 4, it can be easily confirmed whether or not the sealant 5 is applied in an appropriate amount. Thus, the intermediate liquid crystal display device 1 can be reused or discarded when it is confirmed that the sealant 5 is not applied in an appropriate amount without waiting for completion of the liquid crystal display device 1. The manufacturing cost required for the process can be reduced. Thereby, the yield in the manufacturing process of the liquid crystal display device 1 can be substantially improved.

  The present invention is not limited to the above-described embodiment. For example, the marks 3 and 4 may indicate the seal width of the sealant 5 by arrows in addition to the above-described embodiment, and can be formed in various shapes. The formation positions of the marks 3 and 4 can also be formed at portions other than the four corners of the glass substrate 2. Further, the marks 3 and 4 can be formed at five or more locations, respectively. In such a case, the seal width of the sealant 5 can be confirmed with higher accuracy. Further, the material of the marks 3 and 4 is not limited to the material shown in the present embodiment, and various materials can be used. However, it is preferable that the coating process of the marks 3 and 4 can be performed simultaneously in the other processes, and for this purpose, it is necessary to form with the material used for the glass substrates 2 and 31.

  As described above, according to the method for manufacturing a liquid crystal display device and the liquid crystal display device according to the present invention, the application amount of the applied sealant can be easily confirmed by using the post-application seal width confirmation mark. . Thereby, the yield of the liquid crystal display device can be improved, and the pressure of the squeegee can be appropriately managed by feeding back the confirmation result to the sealant application process.

  Moreover, by using the post-bonding seal width confirmation mark, the seal width after bonding a pair of glass substrates can be easily confirmed. Thereby, for example, the viscosity of the sealing agent can be kept constant by feeding back the confirmation result to the viscosity management of the sealing agent.

It is an external view of the glass substrate in the liquid crystal display device which concerns on embodiment of this invention. It is the enlarged view to which a part of glass substrate in the liquid crystal display device which concerns on embodiment of this invention was expanded. It is a partially expanded view of the glass substrate which concerns on other embodiment. (A), (b) is a partially expanded view of the glass substrate which concerns on other embodiment, respectively. It is process drawing which shows the manufacturing process of a glass substrate. It is process drawing which shows the manufacturing process of a liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Glass substrate 3, 4, 7, 8, 9, 10 Mark 5 Sealant 31 Glass substrate

Claims (5)

In a manufacturing method of a liquid crystal display device in which a pair of substrates are bonded to each other with a sealant ,
Forming an island-shaped first seal width confirmation mark and a pair of second seal width confirmation marks spaced apart from each other on one of the pair of substrates ; and
Applying the sealant between the pair of second seal width confirmation marks and overlapping the first seal width confirmation marks along the four sides of the one substrate ;
A first confirmation step for confirming the width of the sealing agent after application and the width of the first seal width confirmation mark;
Bonding the one substrate to the other of the pair of substrates;
A second confirmation step of confirming a width of the sealant after bonding the pair of substrates and a separation length of the second seal width confirmation mark ;
The first seal width confirmation mark is formed at a corner of the one substrate, and the second seal width confirmation mark is formed along any one of the four sides of the one substrate. A method of manufacturing a liquid crystal display device. 2. The method of manufacturing a liquid crystal display device according to claim 1, wherein the first and second seal width confirmation marks are each formed of a light shielding material. 3. The liquid crystal display device according to claim 2, wherein in the first and second confirmation steps, the first and second seal width confirmation mark widths and the width of the sealant are confirmed through fluoroscopy. Production method. 4. The method of manufacturing a liquid crystal display device according to claim 1, wherein the first seal width confirmation mark is formed to have the same width as the sealant after application. . 4. The method according to claim 1 , wherein the second seal width confirmation mark is formed so that a separation length thereof is the same as a seal width after bonding the pair of substrates. A method for manufacturing a liquid crystal display device.

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