JP2008052091A - Method of manufacturing liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To technically easily and inexpensively provide a liquid crystal display comprising a film base material of high display quality in a method of manufacturing the liquid crystal display panelizing the film liquid crystal display comprising at least a color filter, a TFT element and a liquid crystal by supplying two roll film base materials. <P>SOLUTION: The method of manufacturing the liquid crystal display includes aligning the color filter and the TFT element to laminate on one roll film base material, laminating opposite electrodes on the other roll film base material, and bonding to sandwich the liquid crystal by each roll film base material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a liquid crystal display device using a roll film substrate.

  Conventionally, a structure of a liquid crystal display device using an electrode plate for an active matrix liquid crystal display device in which switching elements such as thin film transistors and element drive electrodes (hereinafter abbreviated as TFT elements) are regularly arranged is a color filter ( (Hereinafter abbreviated as CF) having a structure in which a counter electrode substrate having a TFT element and a liquid crystal are sandwiched and bonded under accurate alignment.

  However, in recent years, higher definition has been developed even for mobile applications, and a precise and bright high-quality display has been demanded. The accuracy of bonding of two substrates constituting a panel has been demanded more and more. A slight deviation causes a situation where the display quality is greatly lowered.

  For this reason, a method has been proposed in which a CF defining a display area of a TFT element and a pixel is formed on a single glass substrate (see, for example, Patent Document 1). In this method, a color filter is provided on a glass substrate and a switching element and a pixel driving transparent electrode are formed through an overcoat. By using glass as a base material, the process temperature may be 220 ° C. or higher. It is a premise.

  In recent years, liquid crystal display devices using a plastic substrate have begun to be developed in order to meet the demand for a light, thin display device that does not break. Plastic substrates can be transported in the form of a film due to their flexibility, but there are many problems such as low heat resistance, large thermal expansion coefficient, internal distortion, etc. Although it has been planned, it does not have the characteristics that exceed glass. For this reason, in producing a high-quality and precise display device using a plastic substrate, a countermeasure more than the process using a glass substrate is required.

  In the manufacturing process using a glass substrate, positioning and bonding between the opposing substrates is easy because of the single wafer conveyance. On the other hand, the use of film base material enables the formation of CF and TFT elements by continuous conveyance. However, when aligning and bonding films, the effect of the base material stretches between the screens of each film. Since the pitch is not stable and difficult to control, one or both of the base materials are cut and processed into single wafers, and the advantages of using a roll film base material are lost.

  In addition, the formation of an electrode including CF and a TFT element on a roll film substrate by a photolithographic method is also being studied. However, there is a process of fading or deterioration of CF due to a chemical solution used for forming a TFT element or a heat treatment process. It is necessary to clear issues such as yield reduction due to the longer period.

  As described above, when a liquid crystal display device is manufactured using a roll film substrate, it is required to use a technique different from a manufacturing process using a conventional glass substrate.

Known documents are described below.
Japanese Patent Laid-Open No. 10-239680

The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display device comprising a film base material having a high display quality technically easily and inexpensively.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the invention of claim 1 is to form a film liquid crystal display device comprising at least a color filter, a TFT element, and liquid crystal by supplying two roll film substrates. A method of manufacturing a liquid crystal display device, wherein a color filter and a TFT element are aligned and laminated on one roll film substrate, a counter electrode is laminated on the other roll film substrate, and each of the roll films The liquid crystal display device is manufactured by sandwiching and bonding liquid crystal with a base material.

The invention of claim 2 of the present invention comprises a step of laminating a color filter and a TFT element on a roll film substrate.
(1) First step of forming a color filter on a roll film substrate (2) Second step of forming a TFT element on a glass substrate via a release layer (3) First step of forming a TFT element On the formed roll film substrate, peel and laminate directly at the interface between the TFT element and the release layer, or peel off the TFT element at the interface with the release layer and reversely transfer to a separately prepared roll film substrate, The method for manufacturing a liquid crystal display device according to claim 1, comprising a third step of laminating on the roll film substrate formed in the first step.

The invention of claim 3 of the present invention is the step of laminating a color filter and a TFT element on a roll film substrate.
(1) First step of forming a color filter on a roll film substrate (2) Second step of forming a TFT element on a roll film substrate separately formed with a release layer (3) In the first step 2. The liquid crystal display device according to claim 1, comprising a step of peeling the formed color filter and the TFT element formed in the second step at the interface with the peeling layer, and laminating the transparent insulating layer. This is a manufacturing method.

  The invention of claim 4 of the present invention is characterized in that the structure of the counter electrode formed on the other roll film substrate is that the transparent film and the alignment film are formed of a solid film. 3. The method for producing a liquid crystal display device according to any one of 3 above.

The invention of claim 5 of the present invention is such that the difference in thermal expansion coefficient between the roll film substrate on which the color filter is formed, the roll film substrate on which the TFT element is formed, and the roll film substrate on which the counter electrode is formed is 6 × 10. It is a manufacturing method of the liquid crystal display device of any one of Claims 1-4 characterized by being ^-6 cm / cm / degrees C or less.

  The present invention relates to a liquid crystal display device comprising a roll film substrate, and a liquid crystal display device that facilitates bonding with a counter electrode by consolidating an image display function comprising CF and TFT elements on a substrate on one side. Is the method.

  According to the configuration of the present invention, various problems described in the conventional configuration using a roll film substrate, display defects, color unevenness, and the like do not occur.

  In addition, the number of steps required to improve the shape and accuracy of the conventional device and the maintenance of accuracy are reduced, and the process is simplified.

First, in the first aspect of the present invention, a liquid crystal display device comprising a film liquid crystal display device comprising at least a color filter, a TFT element, and a liquid crystal panel by supplying two roll film substrates is provided. The color filter and the TFT element are aligned and laminated on one roll film substrate, the counter electrode is laminated on the other roll film substrate, and the liquid crystal is formed by each roll film substrate. It is characterized by being sandwiched and bonded.

  In the method for manufacturing a liquid crystal display device of the present invention, the film substrate for the counter electrode has a configuration in which, for example, a barrier layer made of an inorganic film such as SiOx, a transparent conductive film made of a solid film, and an alignment film are laminated. There is no need to provide alignment marks for alignment. If the sealing material is formed and the liquid crystal material is applied to the roll film base material on which the CF and TFT elements are laminated before the two roll film base materials are bonded, the alignment processing of the two roll film base materials is necessary. It is possible to process continuously using a laminating device such as a roll laminator.

  It should be noted that a barrier layer made of an inorganic film such as SiOx to prevent the intrusion of moisture and gas into the liquid crystal layer is transparently insulated on the surface of the roll film substrate or the laminated surface of the CF and TFT elements before forming the CF. It is preferable to form a film having a functional organic or inorganic electrically insulating gas blocking function and an ionic impurity blocking function. By forming the transparent insulating film layer, the TFT element layer can be provided with a function of blocking ionic impurities from the CF layer.

Furthermore, a resin material made of a liquid or dry film thermosetting resin or photo-curing resin can be used for the transparent insulating layer as an adhesive layer between the CF layer and the TFT element layer.
CF is a pattern in which three colors of red, green, and blue, black as a light-shielding film, cyan, yellow, and magenta as complementary colors are patterned. The forming method is a method of patterning a photosensitive pigment-dispersed resist by photolithography processing, and printing. Or a method based on an ink jet method is possible.

  The TFT element may be patterned by forming a conductive film, a functional film, and an insulating film by a printing method or a low-temperature sputtering method. As the conductive film, a metal film or metal compound film made of an Al or Au film, a transparent conductive film made of a metal oxide film such as indium oxide or zirconium oxide, or ink dispersed in a conductive paste such as silver can be used. Copper fetalocyanine (CuPc) or the like can be used as the functional film. As the insulating film, an organic compound, an inorganic oxide film such as SiO2, an amorphous metal oxide film such as Ta2O5, or the like can be used.

  As the alignment film, a polyimide film can be formed by flexographic printing and rubbed, or a photocurable liquid crystal can be exposed and formed.

  According to the second and third aspects of the present invention, the roll film base material on which CF is formed and the TFT element formed separately are laminated, and the processing steps until bonding with the roll film base material on which the counter electrode is formed are concerned. In the second and third aspects, the base substrates on which the TFT elements are formed are different.

  Claim 2 is a process in which the base substrate for forming the TFT element is a glass substrate, with the transparent insulating film formed on the CF sandwiched therebetween, directly from the glass substrate or indirectly through the roll film substrate for transfer. In this method, the TFT element is transferred.

  A third aspect of the present invention is a process in which the base substrate for forming the TFT element is a roll film substrate, and the TFT element is directly transferred from the roll film substrate with a transparent insulating film formed on the CF interposed therebetween.

  A highly moldable organic or inorganic film may be used.

  As a method of aligning the CF on the film substrate and the TFT element, after applying an adhesive material on the CF or TFT element, the layer to be adhered is overlapped while aligning the alignment marks, and fixed by photocuring reaction or thermosetting reaction. This enables high position control.

  In addition, when a roll film substrate is used for transferring a TFT element, lamination processing may be performed in the form of an unwound film. However, in order to facilitate alignment for each CF screen pattern, it is cut into a single wafer state. It is desirable to do so.

  In the invention of claim 4 of the present invention, it relates to the configuration of the counter electrode roll film base material to be bonded to the roll film base material on which CF and TFT elements are laminated, and the counter electrode roll film base material is SiOx or the like. It has a structure in which a barrier layer made of an inorganic film, a transparent conductive film made of a solid film, and an alignment film are laminated, and it is characterized by not having an alignment mark for alignment.

  In a conventional liquid crystal display device using a glass substrate, in order to control driving of TFT elements and color display by CF, the total pitch of CF and TFT elements is controlled by ± 3 microns or less. The CF forming substrate and the counter electrode forming substrate use a glass material having the same thermal expansion coefficient, and exposure is performed using a quartz photomask having a low thermal expansion coefficient, and the total pitch is controlled by temperature control.

  In order to improve the positional accuracy of the TFT element manufactured in a separate process from the CF layer formed on the roll film substrate, it is important to control the amount of deformation and temperature control of the base substrate and the roll film substrate for transfer when manufacturing the TFT element. It becomes. For controlling the deformation amount of the roll film substrate, it is desirable to use a material having a thermal expansion coefficient close to that of the roll film substrate used in the production process.

The thermal expansion coefficient of the roll film base material developed for the current liquid crystal display device is about 20 × 10 ⁻⁶ cm / cm / ° C., and the length of the 5 micron base material changes when the temperature of 1 ° C. changes with a screen size of 250 mm. Changes. In order to ensure the display quality of liquid crystal display devices, the difference in the total pitch between the CF layer and the TFT element must be controlled within ± 1.5 microns. It is desirable that it is 6 × 10 ⁻⁶ cm / cm / ° C. or less.

The roll film substrate for the counter electrode is alignment-free and does not require total pitch accuracy, but in order to reduce the amount of warpage of the liquid crystal display device due to the difference in elongation between the front and back layers after bonding, CF and TFT elements The difference in the coefficient of thermal expansion from the roll film substrate on the side where the film is formed is preferably 6 × 10 ⁻⁶ cm / cm / ° C. or less as in the case of the process material. As the roll film base material, any material other than a flexible material such as a glass plastic plate can be applied, but it may be selected according to the drying temperature in the production process of the present invention. Films or sheets of cycloolefin polymer, polyimide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, etc. can be used. Of these, heat-resistant polyether sulfone, cycloolefin polymer, polyimide and the like are preferable. Moreover, the base material which consists of material which added the inorganic filler to the said resin and improved heat resistance may be sufficient. The film and sheet may be stretched or unstretched.

  Hereinafter, the present invention will be described in detail by way of examples.

An example of a manufacturing process for laminating TFT elements on CF will be described with reference to FIG.
As shown in FIG. 1A, a roll film substrate provided with a barrier layer 12 made of SiOx.
On 11, pigment dispersion CF13 containing an acrylate resin as a resin component was formed.
A transparent coating layer 17 is provided on a glass substrate 14 on which a silane coupling agent is formed as an underlayer 15, and a TFT element 16 including a switching element and a pixel electrode is formed by a plasma CVD method and patterned (FIG. 1 ( b)).

The material for the transparent coating layer may be the same as the material for forming the gas barrier layer on a general film substrate. In order to reduce the gas permeability mainly of moisture and oxygen, a multilayer film including an acrylic resin, a polycarbonate resin, and an inorganic layer such as SiOx and SiN ₄ is raised.
The TFT element 16 is transferred to a film substrate PEN 18 coated with an adhesive, a photocurable adhesive 19 is applied on the CF 13, and the TFT element 16 is aligned with the TFT element 16, and then the adhesive 19 is photocured. Thus, the laminated substrate 10 was formed (FIGS. 1B, C, and D).
Thereafter, the spacer material was patterned by photolithography.
The obtained multilayer substrate could be controlled with a total pitch of ± 1.5 microns, and a roll film CF capable of continuous conveyance with high overlay accuracy between the CF pixel and the TFT element was obtained.

An example of a manufacturing process for laminating TFT elements on CF will be described with reference to FIG.
As shown in FIG. 2A, a pigment-dispersed CF 23 containing an acrylate resin as a resin component was formed on a roll film substrate 21 provided with a barrier layer 22 made of SiOx.
FIG. 2B shows a TFT element 26 formed by patterning by a low-temperature sputter film formation and printing method on a plastic substrate 24 formed with a silane coupling agent as a base layer 25. Further, a transparent coating layer 27 for preventing the impurity ions from bleeding from the CF 23 is formed on the TFT element as shown in FIG.
A photocurable adhesive 28 is applied on the TFT element 26, and FIG. 2 (d) is aligned and overlapped with the CF 23. Then, the adhesive 28 is photocured to form the laminated substrate 20 (FIG. 2). e).
Thereafter, the spacer material was formed by patterning by an ink jet method (FIG. 2F).
The obtained multilayer substrate could be controlled with a total pitch of ± 1.5 microns, and a roll film CF capable of continuous conveyance with high overlay accuracy between the CF pixel and the TFT element was obtained.

An example of a manufacturing process in which a roll film base material in which a TFT element is laminated on CF and a roll film base material on which a counter electrode is formed will be described with reference to FIG.
As shown in FIG. 3A, a PI alignment film 31 was applied on the roll film substrate 30 in which the TFT elements 33 were laminated on the CF 32, and a rubbing process was performed.
Next, FIG. 3B shows the sealant 34 formed by printing with a dispenser.
Next, after dropping the liquid crystal material 35 by the ODF method, FIG. 3C, the transparent electrode 36 and the counter electrode substrate 38 on which the PI alignment film 31 is formed are superposed and sealed to obtain a liquid crystal display device. E).
The obtained liquid crystal display device produced a high-quality screen image without causing display defects or color unevenness.

It is a fragmentary sectional view of the process of laminating a TFT element on CF concerning claim 2 of the present invention. It is a fragmentary sectional view of the process of laminating a TFT element on CF concerning the present invention claim 3. It is explanatory drawing of the bonding process of the present invention.

Explanation of symbols

11, 18, 21, 24, 30, 37 Roll film substrate 12, 22 Barrier layer 13, 23, 32 Color filter 14 Glass substrate 15, 25 Peeling layer 16, 26, 33 TFT element 17, 27 Transparent coating layer 19, 28 Adhesive 31 PI light distribution film 34 Sealant 35 Liquid crystal 36 Transparent electrode

Claims (5)

  A method of manufacturing a liquid crystal display device comprising a film liquid crystal display device comprising at least a color filter, a TFT element, and a liquid crystal panel by supplying two roll film base materials, on one roll film base material A color filter and a TFT element are aligned and laminated, a counter electrode is laminated on the other roll film substrate, and a liquid crystal is sandwiched and bonded by each of the roll film substrates. Production method. The process of laminating color filters and TFT elements on a roll film substrate
(1) First step of forming a color filter on a roll film substrate (2) Second step of forming a TFT element on a glass substrate via a release layer (3) First step of forming a TFT element After peeling and laminating directly on the formed roll film substrate at the interface between the TFT element and the peeling layer, or after peeling off the TFT element at the interface with the peeling layer and transferring to a roll film substrate prepared separately. 2. The method of manufacturing a liquid crystal display device according to claim 1, further comprising a third step of laminating on the roll film substrate formed in the first step. The process of laminating color filters and TFT elements on a roll film substrate
(1) First step of forming a color filter on a roll film substrate (2) Second step of forming a TFT element on a roll film substrate separately formed with a release layer (3) In the first step The formed color filter and the TFT element formed in the second step
The method for producing a liquid crystal display device according to claim 1, comprising a step of peeling at an interface with the peeling layer and laminating with a transparent insulating layer interposed therebetween.   4. The liquid crystal display device according to claim 1, wherein the counter electrode formed on the other roll film substrate has a solid film on the transparent electrode and the alignment film. Manufacturing method. The difference in coefficient of thermal expansion between the roll film substrate on which the color filter is formed, the roll film substrate on which the TFT element is formed, and the roll film substrate on which the counter electrode is formed is 6 × 10 ⁻⁶ cm / cm / ° C. or less. The manufacturing method of the liquid crystal display device of any one of Claims 1-4 characterized by the above-mentioned.