JP2001056402A - Production of microlens substrate and microlens substrate obtained by the same and liquid crystal display element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microlens substrate which allows the exact bonding to a drive substrate. SOLUTION: A protective film of chromium is deposited on the surface of a glass substrate 1 and is patterned with circular openings 2 by which an opening mask 3 is formed. Also, superposition markers X4 are formed in the same staged as for this stage. Next, an etching resistant film 5 is brought into tight contact therewith so as to cover the superposition markers X4 and is subjected to wet process etching, by which hemispherical recessed parts 6 are formed. Further, the opening mask 3 and the etching resistant film 5 are successively peeled. Finally, a high-refractive index material 7 is packed into the recessed parts 6 and cover glass 8 is bonded thereto, by which the microlens substrate 9 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a microlens substrate having microlenses arranged on a surface, and a microlens substrate obtained by the method, and a microlens substrate used for the purpose of improving light use efficiency. The present invention relates to a liquid crystal display element using a lens substrate, and particularly to a method for manufacturing a microlens substrate that requires a step of superimposing a driving circuit formed in a pixel shape on a driving circuit, and a microlens substrate obtained thereby, The present invention relates to a liquid crystal display device using the microlens substrate.

[0002]

2. Description of the Related Art In general, as a liquid crystal display device, a TFT (Thin Film Transistor; TFT) which can obtain a high contrast and is excellent in high image quality and high definition.
A thin-film transistor) driving method has become mainstream. The liquid crystal display element has a structure in which TFTs for controlling a voltage applied to a pixel are arranged in a matrix corresponding to each pixel, and the TFT and the signal wiring are covered with a metal light shielding film called a black matrix. Since the black matrix is opaque, light incident on this portion is absorbed or reflected and is lost. In particular, when increasing the number of pixels to achieve higher definition,
Since it is difficult to reduce the size of a TFT or a signal wiring below a certain limit, an effective portion through which light passes is relatively small, and the aperture ratio is significantly reduced.

[0003] In order to solve this problem, there has been known a method of improving the effective aperture ratio by condensing illumination light at the opening of each pixel of a liquid crystal display element using a microlens. A conventional method of manufacturing such a microlens is disclosed in, for example, Japanese Patent Application Laid-Open No. 60-155552. In the method of manufacturing a microlens described in JP-A-60-15552, first, an acid-resistant metal such as chromium is formed as a protective film on a surface of a transparent substrate such as glass by vapor deposition or sputtering. Next, using a photolithography technique, a circular opening is patterned on the protective film so as to correspond to the pixel arrangement of the liquid crystal display element (the protective film provided with the openings is hereinafter referred to as an opening mask). Next, using a glass etching solution mainly composed of hydrofluoric acid, wet etching is performed through an opening mask. Since wet etching proceeds isotropically, a hemispherical concave portion is obtained at a position corresponding to the opening by etching for a certain period of time. Lastly, the concave portion is filled with a transparent material having a higher refractive index than that of the glass substrate. In this case, the portion filled with the transparent material becomes a micro lens that functions as a convex lens.

Japanese Patent Application Laid-Open No. 8-136704 discloses that, when a microlens is formed by filling a concave portion provided on a transparent substrate with a transparent material, similarly to the technique disclosed in Japanese Patent Application Laid-Open No. 60-15552. A method is disclosed in which an alignment marker is provided on a glass substrate on which a lens is formed, so that a post-process bonding operation with another substrate is facilitated. FIGS. 7A and 7B show a conventional example of a glass substrate having a concave portion to be a microlens obtained by such a manufacturing method, wherein FIG. 7A is a plan view and FIG. 7B is a cross-sectional view.
7B is a cross-sectional view taken along the line XII-XII of FIG. 7A.
FIG. Here, an alignment marker X48 is also formed on the glass substrate in the same process as that for forming the hemispherical concave portion 36 of the prior art described above. That is, the alignment marker X48 is wet-etched similarly to the concave portion 36, and becomes a depression on the glass substrate as shown in FIG. Thus, the concave portion forming glass substrate 47 is completed.

FIG. 8 is a sectional view showing a liquid crystal display device using the glass substrate 47 having the concave portion formed thereon. In this liquid crystal display device, a high refractive index material 37 is embedded in the concave portion 36 of the concave portion forming glass substrate 47 to form a micro lens, and a cover glass 38 is bonded to the concave portion forming glass substrate 47 to form a micro lens substrate 39. The driving substrate 40 is bonded on the microlens substrate 39. The cover glass 38 includes the above-described micro lens,
Although not shown, it is used to keep the distance of the black matrix, and its thickness is determined so that the microlens functions most effectively.

The high-refractive-index material 37 is, for example, an epoxy-based resin, and also serves as an adhesive between the glass substrate 47 and the cover glass 38. Although not shown in the drawing, a drive circuit for driving a liquid crystal such as a TFT is formed in the drive substrate 40 in a pixel shape. The drive substrate 40 is provided with an alignment marker Y49 corresponding to the alignment marker X48, and the microlens substrate 39 and the drive substrate 40 can be bonded together while adjusting the positions of both. As described above, in the microlens substrate of the conventional example shown in FIG. 7, the alignment marker X48 is formed in the same step as the concave portion 36 serving as the microlens, so that the microlens substrate 39 and the driving substrate 40 are bonded. Can be facilitated.

[0007]

The problem of the prior art described above is that the bonding accuracy between the microlens substrate 39 and the driving substrate 40 is low for the following two reasons.
First, the first reason will be described. An alignment marker X48 is formed on the microlens substrate 39 by wet etching simultaneously with the concave portion 36 serving as a microlens. This method obtains the hemispherical concave portion 36 by utilizing the fact that wet etching proceeds isotropically with respect to glass as a material of the microlens substrate. The same phenomenon is caused by the alignment marker X48. Also happens to.
As a result, the alignment pattern 48 has an unintended shape.

FIG. 9A shows a pattern 50 of an alignment marker X before wet etching, and FIG.
(C) shows the position of the alignment marker X actually obtained after the end of the wet etching.
48 shows the shape of the forty-eighth. In the figure, hatched portions represent protective films such as chrome. That is, even if the protective film is patterned as shown in (a), it is enlarged and deformed into a distorted shape as shown in (c) by the isotropic action of wet etching. Therefore, when bonding with the drive substrate 40 by combining with the alignment marker Y49 shown in FIG.
It becomes difficult to perform accurate alignment. Further, since the alignment marker X48 is a depression on the glass substrate, it has high transparency, and its shape can be recognized mainly only at the edge of the depression, and there is a problem in visibility. In order to prevent the alignment pattern 48 from becoming an unintended shape, it is conceivable to adjust the pattern 50 of the alignment marker X in consideration of the influence before wet etching. Therefore, every time the wet etching condition is changed, the size and shape of the pattern 50 of the alignment marker X must be changed according to the condition, which is inefficient and impractical. In FIG. 9A, the pattern 50 of the alignment marker X before the wet etching is performed as a white pattern. However, a pattern of a black background obtained by inverting the pattern 50 is similarly deformed by the wet etching. . However, in this case, the alignment marker X48 after the etching becomes thin.

Next, the second reason will be described. FIG.
As shown in (1), the alignment marker X48 of the microlens substrate 39 and the alignment marker Y49 of the drive substrate 40 face each other via the cover glass 38. Usually, the superposition of the microlens substrate 39 and the driving substrate 40 is performed by enlarging the positioning marker X48 and the positioning marker Y49 with a microscope or a CCD camera, so that the microlens substrate 39 and the driving substrate 40 are exactly overlapped. This is performed while moving any one of 40. Therefore, the alignment marker X
48 and the alignment marker Y49 need to be observed simultaneously, but the thickness of the cover glass 38 is 50 to 100 μm.
In this case, a general microscope or CCD camera cannot simultaneously focus. Therefore, when performing the bonding operation manually, it is necessary to adjust the positions of the microlens substrate 39 and the driving substrate 40 while observing each of the alignment markers by gradually shifting the focus or the like. As described above, in the related art, there is a problem that not only the bonding operation is complicated and difficult, but also the bonding accuracy is reduced. In addition, there is a high possibility that the automatic device cannot cope with the problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a microlens substrate which has high bonding accuracy with a driving substrate and can easily perform the bonding operation, and has been obtained in view of the above-mentioned problems of the prior art. An object of the present invention is to provide a microlens substrate and a liquid crystal display device using the microlens substrate.

[0011]

According to the method of manufacturing a microlens substrate of the present invention, a plurality of concave portions are formed in a first transparent substrate, and a material having a different refractive index from the first transparent substrate in the plurality of concave portions. Filling a second transparent substrate thinner than the first transparent substrate, a method of manufacturing a microlens substrate, comprising: After forming the plurality of recesses on the transparent substrate in the same process and covering the overlay marker with an erosion-resistant protective film, the wet etching is performed through the opening mask to complete the wet etching. Thereafter, the protective coating and the erosion-resistant protective film are peeled in this order, and then the first
A material having a different refractive index from that of the transparent substrate is filled, and finally, the second transparent substrate is bonded.

In the method of manufacturing a microlens substrate according to the present invention having the above-described structure, a visual marker for indicating the position of the overlay marker is formed on the first transparent substrate in the same step as that for the opening mask. Is preferred.

In the method of manufacturing a microlens substrate according to the present invention, a plurality of recesses are formed in a first transparent substrate, and the plurality of recesses are filled with a material having a different refractive index from that of the first transparent substrate. In a method for manufacturing a microlens substrate in which a second transparent substrate thinner than the first transparent substrate is bonded,
An opening mask made of a protective coating in which a plurality of openings are arranged;
Forming an exposure position adjustment marker on the first transparent substrate in the same step, covering the exposure position adjustment marker with an erosion-resistant protective film, and performing wet etching through the opening mask to form the plurality of exposure position adjustment markers. After forming the concave portion and after the wet etching, the protective film and the erosion-resistant protective film are peeled off in this order, and then the concave portions are filled with a material having a different refractive index from the first transparent substrate. And the second
After laminating the transparent substrate, a thin film is formed on the second transparent substrate, and finally, the thin film is exposed and patterned by an exposing machine using the exposure position adjustment marker for positioning to form an overlay marker. It may be characterized in that

In the method of manufacturing a microlens substrate according to the present invention having such a configuration, when forming the thin film on the second transparent substrate, the thin film is not formed above the exposure position adjustment marker. It is preferable to use means for making As a means for preventing the thin film from being formed above the exposure position adjustment marker, a mask that covers the exposure position adjustment marker may be used.

In the method of manufacturing a microlens substrate according to the present invention having the above-described structure, the first transparent substrate may be provided with:
It is preferable that a visual recognition marker that clearly indicates the position of the exposure position adjustment marker is formed in the same step as the opening mask.

Further, in the method of manufacturing a microlens substrate according to the present invention having one of the above structures, the visual recognition marker is a frame surrounding the overlay marker or the exposure position adjustment marker. There may be.

A microlens substrate according to the present invention is characterized by being manufactured by the method for manufacturing a microlens substrate according to the present invention having any one of the above structures.

The liquid crystal display device of the present invention comprises a transparent electrode, an alignment film and, if necessary, a black matrix on a microlens substrate manufactured by the method of manufacturing a microlens substrate of the present invention having any one of the above-mentioned structures. Is formed, and is bonded to the macro lens substrate. On the drive substrate on which the drive circuit is arranged in a pixel shape, an alignment film and, if necessary, a black matrix, and another overlay corresponding to the overlay marker The alignment marker is formed, and a liquid crystal is sandwiched between the microlens substrate and the driving substrate.

Further, the liquid crystal display element of the present invention has a step of forming an opening mask made of a protective film in which a plurality of openings are arranged and an exposure position adjusting marker on the first transparent substrate in the same step. A transparent electrode, an alignment film, and a black matrix are formed on the microlens substrate manufactured by the microlens substrate manufacturing method of the present invention, and a driving circuit to be bonded to the microlens substrate is arranged in a pixel shape. On the drive substrate, an alignment film, and another overlay marker corresponding to the overlay marker are formed,
The liquid crystal may be sandwiched between the microlens substrate and the driving substrate, and the black matrix may be formed in the same process as the overlay marker. .

[0020]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a sectional view showing steps in a first embodiment of a method for manufacturing a microlens substrate according to the present invention. In the description of the embodiment of the present invention, the term “overlay marker” is used, and this overlay marker corresponds to a conventional alignment marker.

First, as shown in FIG. 1A, a protective film made of chromium is formed on the surface of a glass substrate (first transparent substrate) 1, and a circular opening 2 is patterned to form an opening mask 3. I do. At this time, overlapping markers X4 are formed at four corners of the glass substrate 1 or at two places on both ends on the center line. The formation of the opening mask 3 and the overlay marker X4 is performed by general photolithography. That is, after a protective film made of chromium is formed on the entire surface of the glass substrate 1 by sputtering, a photoresist is applied, and the opening 2 and the marker X are superimposed using a photomask.
After the pattern 4 is exposed, the photoresist is developed, and the protective film made of chromium is further etched.
The opening mask 3 and the overlay marker X4 are patterned. Thus, the opening mask 3 and the overlay marker X4 are formed in the same step. In the figure, the opening mask 3 and the superimposition marker X4 are shown for easy understanding.
Although it is described to have a certain thickness, it is actually about 1000 to 2000 angstroms (0.1 to 0.2 μm) thick, which is extremely thin compared to the glass substrate 1 and the cover glass 38 to be bonded later. .

Next, as shown in FIG. 1B, an etching-resistant film (corrosion-resistant protective film) 5 is adhered so as to cover the overlay marker X4. It is preferable that the etching resistant film 5 has erosion resistance to an acidic solution such as hydrofluoric acid and has adhesiveness. For example, a surface protection film SPV (trade name) manufactured by Nitto Denko is used. Next, as shown in FIG. 1C, wet etching is performed using a mixed solution mainly containing hydrofluoric acid. Thus, a hemispherical concave portion 6 is formed. Next, as shown in FIG. 1D, the opening mask 3, which is a protective film made of chromium, is peeled off.
Next, as shown in FIG. 1E, the etching resistant film 5 is peeled off.

Finally, as shown in FIG.
Is filled with a high-refractive-index material 7 and a cover glass (second transparent substrate) 8 is bonded to form a microlens substrate 9. At this time, the high refractive index material 7 includes the glass substrate 1 and the cover glass 8.
Also works as an adhesive. The high refractive material 7 is a glass substrate 1
A material having a higher refractive index than that used is used. Cover glass 8
Has a thickness of about 50 to 100 micrometers.
As described above, since the thickness of the overlay marker X4 is 0.1 to 0.2 micrometers, no trouble occurs when the cover glass 8 is bonded to the glass substrate 1.

FIG. 2 is a plan view showing a stage after the step of FIG. Since the overlay marker X4 is covered with the etching resistant film 5, it is not affected by the wet etching process shown in FIG. Further, even in the step of peeling the opening mask 3 which is the protective film made of chromium shown in FIG. 1D, the chromium forming the overlay marker X4 is not peeled. Therefore, finally, the shape of the superposition marker X4 is maintained as it was originally formed, and enlargement or reduction accompanying deformation cannot occur.

FIG. 3 is a sectional view showing a driving substrate to be bonded to the microlens substrate 9 described above. The drive substrate 10 is not shown in the figure, but is the same as the conventional example.
A driving circuit such as a TFT for driving liquid crystal is formed in a pixel shape. Further, an overlay marker Y11 corresponding to the overlay marker X4 is provided, and the microlens substrate 9 and the drive substrate 10 can be bonded together while adjusting the positions of both. At this time, as described above, the overlay marker X4 is not deformed by wet etching and remains in a perfect shape (with high dimensional accuracy), so that more accurate bonding can be performed as compared with the conventional example. As described above, the first reason in the conventional example, that is, the problem that the accuracy of bonding the microlens substrate and the driving substrate due to the deformation of the alignment marker is reduced, can be solved.

(Second Embodiment) A second embodiment of the method for manufacturing a microlens substrate according to the present invention will be described with reference to the drawings. The manufacturing process in the second embodiment is almost the same as the manufacturing process in the first embodiment, except that the overlay marker X4 in FIG. 1 is replaced with the exposure position adjustment marker. here,
A stepper which is a projection type exposure apparatus is used as an exposure machine for performing exposure patterning. Hereinafter, the exposure position adjustment marker is specifically referred to as a stepper alignment marker.
The stepper alignment marker is used for relative positioning between the first exposure by the stepper and the second exposure performed thereafter, and its accuracy is generally about 1 micrometer or less.

In the method of manufacturing a microlens substrate according to the second embodiment, first, a stepper alignment marker (exposure position adjustment marker) is formed simultaneously with a circular opening mask on a glass substrate similar to the first embodiment. The necessary number of stepper alignment markers are provided at predetermined positions on the glass substrate. The location and number are determined by the manufacturer, type, model, and the like of the stepper, and are in accordance therewith. Then, after the etching resistant film is adhered to cover the stepper alignment marker, wet etching, peeling of the opening mask which is a protective film made of chromium,
The etching resistant film is peeled off in order. Next, a high refractive index material is filled and a cover glass is attached. Up to this point, only the superposition marker X has been replaced by the stepper alignment marker, and this is the same process as in the first embodiment.

FIG. 4 shows the subsequent steps. FIG. 4 (a)
As shown in (1), a thin film 12 made of chromium is formed on the cover glass 8 of the glass substrate 1 on which the stepper alignment marker (exposure position adjustment marker) 13 is formed. Next, as shown in FIG. 4 (b), the thin film 1 is
2 is exposed and patterned to form an overlay marker W14. As described above, by using the stepper, the overlay marker W14 is extremely accurately positioned at a desired position.

FIG. 5A shows the state before the thin film 12 is formed.
That is, a plan view showing a stage before FIG.
2B is a plan view of a mask 15 used when forming the thin film 12. FIG. For relative positioning between the first exposure by the stepper and the second exposure performed thereafter, high-precision measurement using reflected light or diffracted light from the stepper alignment marker 13 is used. Therefore, if reflected light or diffracted light is blocked, positioning becomes impossible. The mask 15 is shaped so as to cover the stepper alignment marker 13. If the mask 15 is placed on the glass substrate at the stage of FIG. The thin film 12 is not formed. Therefore, stepper alignment marker 1
The reflected light and the diffracted light from 3 can pass through the cover glass 8 and can be accurately positioned. However, ITO
When forming a transparent thin film such as (Indium Tin Oxide), it is not necessary to use the mask 15 in particular.

FIG. 6 shows a stepper alignment marker 13.
FIG. 3 is a plan view showing a marker 16 for visual recognition. In the figure, the stepper alignment marker 13 is enlarged for easy understanding, but actually, the stepper alignment marker 13 is much smaller than the visual recognition marker 16. The shape of the stepper alignment marker 13 varies depending on the manufacturer, type, model, and the like of the stepper, and the example shown in the figure is an example.

However, in general, the size is about several hundred micrometers in total, and it is difficult to recognize with the naked eye. For example, the stepper alignment marker 13 shown in FIG.
Several to several tens of them are arranged vertically and horizontally at an interval of 0 micrometers. In the figure, W ₁ is the width of the square-shaped ones. As described above, since the stepper alignment marker 13 is difficult to see with the naked eye, when the step of covering the stepper alignment marker 13 with the above-described etching resistant film 5 is performed artificially, the operation becomes very difficult. Here, as shown in the figure, if the frame-shaped visual marker 16 surrounding the stepper alignment marker 13 is formed in the same step as the opening mask 3 which is a protective film made of chromium, it can be easily formed. The position of the stepper alignment marker 13 can be grasped, and the operation can be performed efficiently. Visual marker 16 is, as here shown, a stepper alignment markers 13 substantially the length of one side arranged in the center L ₁ of about 5 mm, a width L ₂ is preferred if a frame of about 1 mm.

The microlens substrate 9 on which the overlay marker W14 manufactured as described above is formed is bonded to a drive substrate similar to the drive substrate 10 described in the first embodiment. The drive substrate is provided with an overlay marker Z corresponding to the overlay marker W14, and the microlens substrate 9 and the drive substrate can be bonded together while adjusting the positions of both. At this time, the overlay marker W14
Is subjected to exposure and patterning by a stepper after the completion of the wet etching step, so that the deformation due to the wet etching unlike the conventional example cannot occur.

Further, as shown in FIG.
While the positioning marker X48 of the microlens substrate and the positioning marker Y49 of the driving substrate 40 face each other via the cover glass 38 of about 100 μm, in the present embodiment, the overlay marker W14 of the microlens substrate 9
And the overlay marker Z of the drive board are almost in close contact. Therefore, it is possible to focus on both at the same time for observation and to perform high-precision bonding, thereby improving work efficiency.

Strictly speaking, there is a gap of about 5 micrometers into which liquid crystal is injected between the microlens substrate 9 and the driving substrate. However, this gap is sufficiently included in the depth of focus of the microscope, and thus affects the bonding. There is no. As described above, in the present embodiment, the first problem in the conventional example, that is, the problem of lowering the bonding accuracy between the microlens substrate and the driving substrate due to the deformation of the alignment marker, is of course the second problem. In addition, it is possible to solve the problem that the bonding accuracy is lowered due to the defocus of both the alignment markers of the microlens substrate and the driving substrate. Further, the lamination can be performed easily, and the work efficiency can be improved. In addition, it is possible to cope with an automatic device.

Although the embodiment has been described above by exemplifying a glass substrate as the transparent substrate, it is not particularly limited to glass. Various materials such as general soda glass, non-alkali glass, and quartz glass can be used for the glass. Further, the superposition marker may be a river shape, a square, or a more complicated shape other than the cross shape shown in the above embodiment.

On the surface of the microlens substrate 9 manufactured by the method of manufacturing a microlens substrate according to the above-described two embodiments, a transparent electrode, an alignment film, and, if necessary, a black matrix are formed. . Further, on the surface of the drive substrate to be bonded thereto, a drive circuit arranged in a pixel shape, an alignment film, and, if necessary, a black matrix, and another overlay marker corresponding to the overlay marker are formed. . The liquid crystal display device of this embodiment has a structure in which liquid crystal is sandwiched between the microlens substrate of the first or second embodiment and the drive substrate. In particular, in the microlens substrate according to the second embodiment, if the black matrix provided on the microlens substrate 9 is formed in the same step as the overlay marker W14 on the cover glass 8, the efficiency of the manufacturing process is improved. be able to. As described above, in the liquid crystal display device using the microlens substrate of the present embodiment, optical loss is extremely reduced by accurate bonding. Therefore, it is possible to realize a high brightness display device such as a liquid crystal projector incorporating the liquid crystal display element.

[0037]

As described above, in the method of manufacturing a microlens substrate according to the present invention, the overlay marker is protected by the erosion-resistant protective film before performing the wet etching. The correct shape is maintained without deformation. As a result, accurate bonding of the microlens substrate and the drive substrate becomes possible. Further, in a method of protecting the exposure position adjustment marker with an erosion-resistant protective film in the same manner, and then patterning the overlay marker on a cover glass by an exposure machine, the conventional problem of defocus is solved. be able to. As a result, accurate bonding of the microlens substrate and the drive substrate becomes possible. Therefore, according to the method for manufacturing a microlens substrate of the present invention, it is possible to provide a microlens substrate that has high bonding accuracy with a driving substrate and can easily perform a bonding operation.

Further, since the liquid crystal display element of the present invention uses the microlens substrate manufactured by the method of manufacturing a microlens substrate of the present invention, optical loss is extremely reduced by accurate bonding. Therefore,
High brightness of a liquid crystal display device such as a liquid crystal projector incorporating the liquid crystal display element of the present invention can be realized. As described above, the liquid crystal display device using the microlens substrate manufactured by the method for manufacturing a microlens substrate of the present invention is extremely useful in industry.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing steps in a first embodiment of a method for manufacturing a microlens substrate of the present invention.

FIG. 2 is a plan view showing a stage after a specific step in the first embodiment of the method for manufacturing a microlens substrate of the present invention.

FIG. 3 is a cross-sectional view showing a driving substrate to be bonded to the microlens substrate obtained by the first embodiment of the method for manufacturing a microlens substrate of the present invention.

FIG. 4 is a cross-sectional view showing a step in a second embodiment of the method for manufacturing a microlens substrate of the present invention.

FIG. 5A is a plan view showing a stage after a specific step in the second embodiment of the method for manufacturing a microlens substrate of the present invention, and FIG. 5B is a plan view showing an example of a mask used there. is there.

FIG. 6 is a plan view showing an example of a stepper alignment marker and a visual recognition marker used in a second embodiment of the method for manufacturing a microlens substrate of the present invention.

FIGS. 7A and 7B are diagrams showing a conventional example of a glass substrate having a concave portion serving as a microlens, in which FIG.
(B) is a sectional view taken along line XII-XII of (a).

8 is a cross-sectional view showing a conventional liquid crystal display device using a glass substrate having a concave portion shown in FIG.

9A is a diagram illustrating a pattern of an alignment marker before performing wet etching by a conventional method of manufacturing a microlens substrate, FIG. 9B is a diagram illustrating a shape of an alignment marker formed on a driving substrate, and FIG. FIG. 4 is a plan view showing the shape of an alignment marker obtained after wet etching.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 glass substrate (first transparent substrate) 2 opening 3 opening mask (protective coating) 4 overlay marker X 5 etching resistant film (erosion resistant protective film) 6 recess 7 high refractive index material 8 cover glass (second transparent) Substrate) 9 Microlens substrate 10 Driving substrate 11 Superposition marker Y 12 Thin film 13 Stepper alignment marker (exposure position adjustment marker) 14 Superposition marker W 15 Mask 16 Visual marker 36 Depression 37 High refractive index material 38 Cover glass 39 Micro lens Substrate 40 Drive substrate 47 Glass substrate with concave portion 48 Alignment marker X 49 Alignment marker Y

Continuation of the front page (72) Inventor Jin Matsushima 5-7-1 Shiba, Minato-ku, Tokyo F-term in NEC Corporation (reference) 2H091 FA29Y FA35Y FC10 FC26 FD12 FD15 GA03 GA06 LA12 4G059 AA11 AB06 AC01 AC30 BB04

Claims (10)

[Claims] 1. A plurality of recesses are formed in a first transparent substrate,
In the method for manufacturing a microlens substrate, in which the plurality of recesses are filled with a material having a different refractive index from the first transparent substrate and a second transparent substrate thinner than the first transparent substrate is bonded, An opening mask made of an array of protective coatings;
An overlay marker is formed on the first transparent substrate in the same step, and the overlay marker is covered with an erosion-resistant protective film. Then, the plurality of recesses are formed by performing wet etching through the opening mask. After the completion of the wet etching, the protective coating and the erosion-resistant protective film are peeled off in this order, and then the plurality of recesses are filled with a material having a different refractive index from the first transparent substrate. And bonding the second transparent substrate to the microlens substrate. 2. A plurality of recesses are formed in a first transparent substrate,
In the method for manufacturing a microlens substrate, in which the plurality of recesses are filled with a material having a different refractive index from the first transparent substrate and a second transparent substrate thinner than the first transparent substrate is bonded, An opening mask made of an array of protective coatings;
Forming an exposure position adjustment marker on the first transparent substrate in the same step, covering the exposure position adjustment marker with an erosion-resistant protective film, and performing wet etching through the opening mask to form the plurality of exposure position adjustment markers. After forming the concave portion and after the wet etching, the protective film and the erosion-resistant protective film are peeled off in this order, and then the concave portions are filled with a material having a different refractive index from the first transparent substrate. And the second
After laminating the transparent substrate, a thin film is formed on the second transparent substrate, and finally, the thin film is exposed and patterned by an exposing machine using the exposure position adjustment marker for positioning to form an overlay marker. A method of manufacturing a microlens substrate. 3. The microlens substrate according to claim 1, wherein a visual marker for clearly indicating the position of the overlay marker is formed on the first transparent substrate in the same step as the opening mask. Manufacturing method. 4. A means for preventing the thin film from being formed above the exposure position adjustment marker when the thin film is formed on the second transparent substrate. A method for manufacturing a microlens substrate. 5. A visual recognition marker for specifying the position of the exposure position adjustment marker is formed on the first transparent substrate in the same step as the step of forming the aperture mask.
Or the method for manufacturing a microlens substrate according to 4. 6. The method of manufacturing a microlens substrate according to claim 3, wherein the visual marker is a frame surrounding the overlay marker or the exposure position adjustment marker. 7. A mask for masking the exposure position adjustment marker when depositing the thin film on the second transparent substrate, the means for preventing the thin film from being deposited above the exposure position adjustment marker. 5. The method for manufacturing a microlens substrate according to claim 4, wherein: 8. A microlens substrate manufactured by the method of manufacturing a microlens substrate according to claim 1. Description: 9. The microlens substrate according to claim 1, wherein a transparent electrode, an alignment film and, if necessary, a black matrix are formed on the microlens substrate manufactured by the method for manufacturing a microlens substrate according to claim 1. An alignment film, and a black matrix as needed,
A liquid crystal display device having a structure in which another overlay marker corresponding to the overlay marker is formed, and a liquid crystal is sandwiched between the microlens substrate and the driving substrate. 10. A driving circuit, wherein a transparent electrode, an alignment film, and a black matrix are formed on a microlens substrate manufactured by the method for manufacturing a microlens substrate according to claim 2, and the driving circuit is bonded to the microlens substrate. On the drive substrate in which pixels are arranged, an alignment film and another overlay marker corresponding to the overlay marker are formed,
A liquid crystal display device having a structure in which liquid crystal is sandwiched between the microlens substrate and the driving substrate, wherein the black matrix is formed in the same step as the overlay marker.