JP2001305519A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance bonding accuracy of a pixel electrode substrate and a microlens substrate, and to eliminate an inspection process which is complicated and requires cost when the pixel electrode substrate and microlens substrate which composes a liquid crystal display panel are stuck together. SOLUTION: In a method manufacturing a liquid crystal display device including a process for positioning and sticking together the pixel electrode substrate 2 on which a pixel electrode pattern 1 is formed, and the microlens substrate 4 on which a microlens pattern 3 corresponding to the pixel electrode pattern 1 is formed, an alignment reference point 1b in the pixel in the pixel electrode pattern 1 of the electrode substrate 2 and an alignment reference point 3b in the microlens in the microlens pattern 3 of the microlens substrate 4 are positioned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a step of aligning and bonding a pixel electrode substrate on which a pixel electrode pattern is formed and a microlens substrate on which a microlens pattern corresponding to the pixel electrode pattern is formed. The present invention relates to a method for manufacturing a liquid crystal display device and a bonding device.

[0002]

2. Description of the Related Art A type of liquid crystal display panel is widely used in which a pixel electrode substrate on which a pixel electrode pattern is formed and a microlens substrate on which a microlens pattern corresponding to the pixel electrode pattern are formed are bonded. I have.

Conventionally, when a pixel electrode substrate and a microlens substrate are bonded to each other, an alignment mark provided before the pixel electrode pattern of the pixel electrode substrate and an alignment mark provided outside the microlens pattern of the microlens substrate are provided. And the two are pasted together. In this case, since a microlens substrate is used, very high positioning accuracy is required. Specifically, the pixel electrode substrate is held on a surface plate, while the microlens substrate is held on a holder,
Each alignment mark is irradiated with light from a light source installed in a hole formed in the surface plate, and the transmitted light is detected by a mark detection means including a microscope and a camera provided above the holder, Based on the obtained detection data, the surface plate and the holder are relatively moved in the vertical direction, the front-rear left-right direction, and the θ direction by a positioning mechanism such as a ball screw mechanism or a rotary eccentric cam provided on one of the surface plate and the holder. The substrates are moved and aligned, and then both substrates are pressed and bonded with a resin-based fixing agent.

[0004]

However, in the conventional case of bonding a pixel electrode substrate and a microlens substrate, each alignment mark is detected, and the detected alignment mark is set within a predetermined error range by a positioning mechanism. After the two substrates are matched with each other, the two substrates are pressurized, and the substrates are fixed together by applying pressure to the platen and holder, causing elastic deformation in the alignment mechanism, twisting of the drive system, and the drive system. There is a problem that a position shift based on a deformation or the like in the power transmission system and a position shift based on an error in forming an alignment mark on the substrate itself occur. Further, a positional shift due to external vibration during pressurization also occurs. For this reason, in the liquid crystal display panel after the bonding, there is a case where a deviation occurs even at the pixel level for the display pattern. Therefore, a complicated and costly inspection process for inspecting the state of bonding of the two substrates after the bonding is indispensable, and there are not a few liquid crystal display panels which are determined to be defective in this inspection process.

An object of the present invention is to solve the problems of the prior art. When a pixel electrode substrate and a microlens substrate are bonded to each other, the accuracy of the bonding is improved, and a complicated and costly inspection is performed. The purpose is to be able to omit the process.

[0006]

SUMMARY OF THE INVENTION The present inventor has proposed that the conventional alignment is not based on the pixel electrode pattern and the microlens pattern to be most aligned, but the alignment mark and the microlens outside the pixel electrode pattern on the pixel electrode substrate. The present inventors have found that a problem arises in the accuracy of the alignment mark based on the alignment mark outside the microlens pattern on the substrate, and have completed the present invention.

That is, the present invention provides a liquid crystal display including a step of aligning and bonding a pixel electrode substrate on which a pixel electrode pattern is formed and a microlens substrate on which a microlens pattern corresponding to the pixel electrode pattern is formed. A method of manufacturing a device, comprising: aligning an alignment reference point in a pixel in a pixel electrode pattern of a pixel electrode substrate with an alignment reference point in a microlens in a microlens pattern of a microlens substrate. I do. In this manner, since the alignment reference point in the pixel in the pixel electrode pattern to be most aligned and the alignment reference point in the microlens in the microlens pattern are directly aligned, highly accurate alignment is possible. Further, if the pixel electrode substrate and the microlens substrate are fixed while repeating the alignment, the alignment accuracy can be further improved, and the inspection step after the fixing can be omitted.

In the present invention, the alignment reference point in the pixel is an intersection of diagonal lines formed from four pixel electrodes (preferably the respective center points) at the four corners of the pixel electrode pattern. It is preferable that the intersection of diagonal lines formed by four microlenses (preferably, the respective center points) at the four corners of the microlens pattern is used in order to make the overall accuracy uniform. In this case, the pixel center point of each of the four pixels at the four corners of the pixel electrode pattern can be easily obtained by image edge processing, and the micro lens center point can be easily obtained by image bright point processing using a cross filter. be able to.

When the alignment reference point in the pixel and the alignment reference point in the microlens are obtained, the center point and the center point of a predetermined one electrode pixel are selected without selecting the four pixel electrodes at the four corners or the four microlenses at the four corners. The center point of one predetermined micro lens may be set as the reference point.

Before the alignment reference point in the pixel in the pixel electrode pattern region of the pixel electrode substrate and the alignment reference point in the microlens in the microlens pattern of the microlens substrate are aligned, the alignment accuracy of the microlens pattern must be adjusted. Preliminarily aligning the extra-pixel alignment mark outside the pixel electrode pattern area of the pixel electrode substrate with the microlens alignment mark outside the microlens pattern of the microlens substrate with coarse accuracy, thereby facilitating the alignment operation. It becomes possible.

Further, the present invention provides a bonding apparatus suitable for carrying out the above-described manufacturing method, a platen for holding a pixel electrode substrate on which an electrode pattern is formed, and a microplate corresponding to the pixel electrode pattern. A holder for holding a microlens substrate on which a lens pattern is formed, an alignment mark for alignment between the pixel electrode substrate and the microlens substrate, or a mark detecting means such as a microscope for confirming the pixel electrode or the microlens; An image processing means for obtaining an alignment reference point in a pixel in a pixel electrode pattern region of a pixel electrode substrate and an alignment reference point in a microlens in a microlens pattern of a microlens substrate from information obtained by the mark detection means; Position the alignment reference point and the alignment reference point in the macro lens And a positioning mechanism that relatively moves the platen and holder in the up, down, front, back, left and right directions and the θ direction so that the pixel electrode substrate and the microlens substrate are aligned by the positioning mechanism. Provided is a device for bonding a pixel electrode substrate and a microlens substrate, the device including a pressurizing means capable of pressing. In this case, it is preferable to provide a light source for irradiating the alignment mark for alignment or the pixel electrode or the microlens from inside or below the surface plate. Further, it is preferable that a mark filter is provided with a cross filter for obtaining a micro lens center point of the micro lens.

[0012]

FIG. 1 is an example of a conceptual diagram of a manufacturing method according to the present invention.

First, a pixel electrode substrate 2 on which a pixel electrode pattern 1 is formed (FIG. 1A) and a microlens substrate 4 on which a microlens pattern 3 corresponding to the pixel electrode pattern 1 is formed (FIG. 1B )) And prepare. Outside pixel alignment marks 2a are formed at four corners outside the pixel electrode pattern 1, and pixel electrodes 1a for alignment are selected at the four corners within the pixel electrode pattern 1. Further, alignment marks 4a outside the microlens are formed at the four corners outside the microlens pattern 3, and the microlens 3a for alignment is selected at the four corners inside the microlens pattern 3.

Next, the extra-pixel alignment mark 2a and the extra-microlens alignment mark 4a are detected by mark detecting means such as a microscope, and the pixel electrode substrate 2 and the micro lens substrate 4 are relatively positioned based on the detected information. To align the out-of-pixel alignment mark 2a and the out-of-pixel alignment mark 4a (FIG. 1).
(C)). In this case, alignment with relatively coarse accuracy of about ± 1.0 μm may be performed.

Next, the four pixel electrodes 1a at the four corners in the pixel electrode pattern 1 are detected by a microscope as mark detection means,
A diagonal line is drawn from the four pixel electrodes 1a by image processing, and the intersection is set as an intra-pixel alignment reference point 1b (FIG. 1 (c)). In this case, the center point of the pixel electrode 1a can be obtained by image edge processing. Further, four micro lenses 3a at the four corners in the micro lens pattern 3 are detected by mark detecting means such as a microscope, a diagonal line is drawn from the four micro lenses 3a by image processing, and the intersection is defined as an alignment reference point 3b in the micro lens. (FIG. 1C). In this case, the center point of the microlens 3a can be obtained as the brightest bright spot in the observed image (FIG. 2A) by installing a cross filter before the mark detecting means. More specifically, as shown in FIG.
The center line of (interval) may be the Y axis, the same center line in the X direction may be the X axis, and the XY intersection may be the center point of the microlens 3a.

Next, the alignment reference point 1b in the pixel and the alignment reference point 3b in the microlens are overlapped by image processing (FIG. 1D). In this case, ± 0.1
The alignment is performed with relatively high accuracy of about μm.

In this state, the pixel electrode substrate 2 and the microlens substrate 4 are pressurized around the periphery thereof with a sealant or the like, and the alignment reference point 1b in the pixel and the alignment reference point 3b in the microlens are again processed by image processing. Overlap and press again. After the pressurization is completed, it is fixed with a resin fixing agent or the like.

Next, FIG. 3 shows an example of a bonding apparatus suitable for carrying out the manufacturing method of the present invention. This apparatus comprises a surface plate 32 for holding a pixel electrode substrate 31 on which a pixel electrode pattern is formed, and a microlens substrate 3 on which a microlens pattern corresponding to the pixel electrode pattern is formed.
3 and a pixel electrode substrate 31
And an alignment mark (not shown) for aligning the microlens substrate 33 or a microscope 35 as mark detection means for confirming a pixel electrode or a microlens, and a pixel electrode substrate 31 based on information obtained by the mark detection means. Image processing means (not shown) such as a personal computer for obtaining an intra-pixel alignment reference point in the pixel electrode pattern region and an in-microlens alignment reference point in the microlens pattern of the microlens substrate;
A positioning mechanism (not shown) that relatively moves the platen 32 and the holder 34 in the up-down direction, the front-rear left-right direction, and the θ direction so that the alignment reference point in the pixel and the alignment reference point in the macro lens can be aligned. And a pressing means (not shown) capable of pressing the pixel electrode substrate and the microlens substrate in a state where they are aligned by an alignment mechanism. Further, a light source 37 for irradiating light to an alignment mark for alignment or a pixel electrode or a microlens is provided in the back of a hole 36 formed in the surface plate 32.

In this device, light from a light source 37 passes through a pixel electrode substrate 31 and a microlens substrate 33, passes through a hole 38 formed in a holder 34, passes through two prisms 39 and 40, and then passes through a microscope. It is incident on 35 and detected. In this case, a cross filter 41 can be provided between the prism 40 and the microscope 35 as a component of the mark detecting means. Two mirrors may be used instead of two prisms.

Further, a movable microscope 35 may be used as shown in FIG. 4 instead of the prism and the mirror.

[0021]

According to the present invention, when the pixel electrode substrate and the microlens substrate are aligned, pressurized, fixed and bonded at the pixel level, high precision is achieved. Can be bonded, and a high-quality liquid crystal display device can be manufactured. In addition, it is possible to correct misalignment in the pressing stage and misalignment in forming the alignment mark on the pixel electrode substrate or the microlens substrate, so that occurrence of a product defect due to misalignment after bonding can be suppressed. Therefore, the inspection step after the bonding step can be omitted.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a manufacturing method of the present invention.

FIG. 2 is an explanatory diagram when a cross filter is used.

FIG. 3 is a schematic view of a bonding apparatus suitable for performing the manufacturing method of the present invention.

FIG. 4 is a schematic view of a bonding apparatus suitable for carrying out the manufacturing method of the present invention.

[Explanation of symbols]

1 pixel electrode pattern, 1a alignment pixel electrode,
1b In-pixel alignment reference point, 2 pixel electrode substrate, 2a Non-pixel alignment mark, 2b In-pixel alignment reference point, 3 micro lens pattern, 3a
Microlens for alignment, 3b Reference point in microlens, 4 microlens substrate, 4
a Alignment mark outside micro lens

Claims (8)

[Claims] 1. A method for manufacturing a liquid crystal display device, comprising: aligning and bonding a pixel electrode substrate on which a pixel electrode pattern is formed and a microlens substrate on which a microlens pattern corresponding to the pixel electrode pattern is formed. 5. The manufacturing method according to claim 1, wherein an alignment reference point in the pixel in the pixel electrode pattern of the pixel electrode substrate is aligned with an alignment reference point in the microlens in the microlens pattern of the microlens substrate. 2. An intra-pixel alignment reference point is an intersection of diagonal lines formed from four pixel electrodes at four corners of a pixel electrode pattern, and an intra-microlens alignment reference point is four microlenses at four corners of a microlens pattern. 2. The method according to claim 1, wherein the intersection is a diagonal line formed from: 3. The pixel center point of each of the four pixels at the four corners of the pixel electrode pattern is determined by image edge processing, an intra-pixel alignment reference point is determined based on the obtained pixel center point, and the four corners of the microlens pattern are determined. 3. The microlens center point of each of the four microlenses is obtained by image bright spot processing using a cross filter, and the alignment reference point in the microlens is obtained based on the obtained microlens center point. Production method. 4. An alignment reference point in a pixel in a pixel electrode pattern area of a pixel electrode substrate and an alignment reference point in a microlens in a microlens pattern of a microlens substrate before alignment are adjusted. 4. The pre-alignment method according to claim 1, wherein coarse alignment marks outside the pixel electrode pattern area of the pixel electrode substrate and micro lens alignment marks outside the micro lens pattern of the micro lens substrate are roughly aligned. Manufacturing method. 5. After aligning the alignment reference point in the pixel with the alignment reference point in the microlens, the pixel electrode substrate and the microlens substrate are pressurized, and in that state, the alignment is performed again and the pressure is applied again. The method according to any one of claims 1 to 4. 6. A platen for holding a pixel electrode substrate on which a pixel electrode pattern is formed, a holder for holding a microlens substrate on which a microlens pattern corresponding to the pixel electrode pattern is formed, and a pixel electrode. A mark detecting means for confirming an alignment mark or a pixel electrode or a micro lens for alignment between the substrate and the microlens substrate, and an intra-pixel alignment in a pixel electrode pattern area of the pixel electrode substrate from information obtained by the mark detecting means. Image processing means for determining a reference point and an alignment reference point in a microlens in a microlens pattern of a microlens substrate, and a platen and a holder so that the alignment reference point in a pixel and the alignment reference point in a macrolens can be aligned. Relatively movable in up / down direction, front / rear / left / right direction and θ direction A pixel electrode substrate and a microlens substrate, wherein the pixel electrode substrate and the microlens substrate are pressurized in a state where the pixel electrode substrate and the microlens substrate are aligned by the positioning mechanism. Bonding equipment. 7. The bonding apparatus according to claim 6, wherein a light source for irradiating light to an alignment mark, a pixel electrode, or a microlens for alignment from inside or below the surface plate is provided. 8. The bonding apparatus according to claim 6, wherein the mark detecting means is provided with a cross filter for determining a center point of the micro lens.