JP2012185788A - Manufacturing method of color filter substrate with touch panel electrode, color filter substrate with touch panel electrode and transparent substrate having inner marker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter substrate with a touch panel electrode by enabling easy and accurate positioning in providing the touch panel electrode composed of plural layers including a pattern and the color filter layer on mutually opposing side surfaces of a transparent substrate.SOLUTION: There is provided a method for forming a touch panel electrode on one surface of a transparent substrate and forming a color filter on the other surface. Before forming the touch panel electrode and the color filter, inner markers are formed inside the transparent substrate using a laser source. Then, the touch panel electrode and the color filter are formed with the inner markers as indices.

Description

  The present invention relates to a color filter substrate with a touch panel electrode used for a liquid crystal display device with a touch panel and the like.

  The touch panel is a component of an input device that allows the operator to touch a transparent surface on the display screen with a finger or a pen to detect a touched position and input data. In recent years, it has been widely used in an input / output device combined with a display device such as a liquid crystal display device.

  There are various types of touch panel detection methods such as resistance type, capacitance type, ultrasonic type, optical type, etc. Among them, the capacitive type touch panel without moving parts has high optical characteristics (transmittance) and durability. In terms of performance and operating temperature characteristics, the resistance type is superior to that of the resistance type. Therefore, development is progressing especially for high reliability applications such as in-vehicle use.

  Capacitive touch panels can be broadly classified into surface types and projection types. The surface type is used for large products of 10 type (25.4 cm size) or more, and the projection type is used for small items of 6 types or less for portable devices. Often. As an electrode plate for a capacitive touch panel, a surface type that does not require a complicated pattern and has a simple structure is composed of a transparent substrate, a transparent conductive film, a simple terminal electrode pattern, and an insulating film. It is difficult to simultaneously detect contact points that are greater than or equal to a point. On the other hand, the structure of the electrode plate for the capacitive touch panel is such that the first transparent electrode pattern layer, the first insulating layer, the second transparent electrode pattern layer, and the metal electrode pattern layer serving as the terminal electrode are formed on the transparent substrate. There is also a projection type in which each layer is generally formed in this order in a laminated structure with two insulating layers. The projection type has a complicated structure and is suitable for a small size, but can detect two or more contact points simultaneously.

  In order to produce an electrode plate for a touch panel, in particular, in the case of a capacitive projection type having a complicated structure, it is particularly important to accurately align positions between patterns of layers sequentially formed on a transparent substrate. Usually, even when alignment is performed by an alignment mechanism of an exposure machine in a photolithographic process, or when alignment is performed by a non-exposure process in printing or the like, The pattern position of the upper layer to be formed later is determined using the layer pattern as an index.

  On the other hand, in order to avoid that the whole panel becomes thick by disposing an independent touch panel on the front surface of the liquid crystal display device or the like, as shown in Patent Document 1, the outer surface of the observation side substrate and the observation side substrate of the liquid crystal display panel are used. It has been proposed to provide an electrode structure for a touch panel between the polarizing plate disposed on the outer surface of the touch panel. Furthermore, in order to achieve the same thinning effect as described above and to shorten the manufacturing process, a touch panel electrode plate and a color filter substrate essential for a color liquid crystal display device are formed as an integral part, and a color filter with a touch panel electrode Attempts have also been made to supply it as a substrate.

To make the color filter substrate with a touch panel electrode, first, a touch panel electrode pattern consisting of the above-mentioned multiple layers is laminated on one surface of a transparent substrate, usually using glass, and then on the other surface of the transparent substrate. A method of forming a color filter layer comprising a black matrix pattern and a transparent colored layer pattern of each color is generally used.
As an index for alignment when forming the color filter substrate with the touch panel electrode, for example, the first layer of the capacitive projection type touch panel electrode pattern is used as a metal film patterning step, and an alignment mark is simultaneously formed. Form. In the following steps, each layer pattern is formed using this alignment mark as a reference, and each layer pattern of the color filter on the opposite surface is also formed using the alignment mark as a reference that will be positioned on the back surface when forming the color filter. it can.

In the above example, when the alignment mark and the processing layer to be patterned are on the opposite side of the transparent substrate, when reading the alignment mark with an exposure machine in the photolithography method, reading errors are likely to occur frequently and manufacture smoothly. It is difficult to proceed with the process. Further, even when alignment is performed by a non-exposure process in printing or the like, the alignment visual recognition accuracy becomes much more difficult than in the case of alignment in the same plane.
Furthermore, by using the reference marks on the same surface separately for the patterns formed on different surfaces of the transparent substrate, the alignment between multiple layers on the same surface is improved, but each pattern on the opposite surface It is difficult to centrally manage the positional accuracy and total pitch between them, and it is difficult to obtain high manufacturing quality.

JP 2008-9750 A

  The present invention is proposed in view of the above-mentioned problems, and the problem to be solved by the present invention is that a touch panel electrode composed of a plurality of layers including a pattern and a color filter layer are arranged on opposite sides of a transparent substrate. It is to provide a color filter substrate with a touch panel electrode by easily enabling accurate positioning when it is provided on the surface.

  As means for solving the above-mentioned problems, the invention according to claim 1 is a method of forming a touch panel electrode on one surface of a transparent substrate and forming a color filter on the other surface. Prior to forming the color filter, an inner marker is formed inside the transparent substrate using a laser light source, and a touch panel electrode and a color filter are formed using the inner marker as an index. A method for manufacturing a substrate.

  According to a second aspect of the present invention, in the method for producing a color filter substrate with a touch panel electrode according to the first aspect, an alignment mark and a vernier for positional accuracy management are provided as a plurality of locations as inner markers. is there.

  The invention according to claim 3 is the method for producing a color filter substrate with a touch panel electrode according to claim 1 or 2, wherein the inner marker is used and formed by photolithography.

  The invention according to claim 4 is the color filter substrate with a touch panel electrode manufactured by the manufacturing method according to any one of claims 1 to 3, wherein the transparent substrate is a glass substrate.

  In addition, the invention according to claim 5 has an inner marker inside the transparent substrate, and makes it possible to use the inner marker uniformly as an alignment index of a plurality of patterns formed on both the front and back surfaces of the substrate. A transparent substrate having an inner marker as a feature.

  In the present invention, an inner marker is formed inside a transparent substrate, and the inner marker is used as a common indicator, so that touch panel electrodes and color filters are formed on different surfaces of the transparent substrate. The color filter substrate with a touch panel electrode of excellent quality can be provided by enabling the matching easily.

It is a partial cross-sectional schematic diagram for demonstrating the structural example of the color filter substrate with a touch-panel electrode of this invention. It is a partial cross-sectional schematic diagram for demonstrating the structural example of the liquid crystal display device using the color filter substrate with a touch-panel electrode of this invention. It is a schematic diagram for demonstrating the alignment method by an alignment mark, Comprising: (a) is a perspective schematic diagram which shows the whole alignment method, (b1), (b2) reads the mark part of each board | substrate with a camera. (C) is a schematic diagram showing the alignment state of the read image on the monitor screen. It is a schematic diagram for demonstrating the management method of the positional accuracy by a vernier.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 2 is a partial cross-sectional schematic view for explaining a structural example of a liquid crystal display device using the color filter substrate with a touch panel electrode of the present invention.

  The internal structure of the liquid crystal display cell 10 shown in this example is a liquid crystal molecule control method of a vertical electric field method such as a TN method, an active matrix method using a TFT (thin film transistor) as a pixel driving element, and what is a TFT? Although a CF bonded structure in which a CF (color filter) colored layer is provided on another substrate is displayed, the liquid crystal display cell to which the color filter substrate with a touch panel electrode of the present invention is applied is not limited thereto. In this example, a black matrix 3 and a color filter coloring layer 7 are formed on one surface of the first transparent substrate 1, and an insulating layer 4, a transparent counter electrode 12 and a liquid crystal alignment film 9 are formed to cover them. A display side substrate from which the display light 15 of the liquid crystal display cell 10 is emitted, and a liquid crystal driving circuit (TFT element and wiring layer) 5, a pixel electrode 8, and a liquid crystal alignment film 9 are formed on one surface of the second transparent substrate 2. The backlight side substrate on which the backlight illumination light 14 is incident, and the liquid crystal layer 11 is sandwiched between the liquid crystal alignment films 9 of the display side substrate and the backlight side substrate, While constituting the liquid crystal display cell 10, the polarizing layer 13 can be provided on the two outer planes of the liquid crystal display cell 10.

  In the present invention, when a liquid crystal display device with a touch sensor function in which the display side substrate of the liquid crystal display cell 10 is provided with a touch sensor function is configured, the touch sensor function portion is externally attached after the liquid crystal display cell 10 is completed. Instead, before the liquid crystal display cell 10 is completed, the touch panel electrode 20 that imparts the touch sensor function to the surface opposite to the color filter coloring layer 7 of the first transparent substrate 1 constituting the display side substrate. The color filter substrate with a touch panel electrode is formed as a component capable of manufacturing a thin display device by simplifying the assembly process.

FIG. 1 is a partial cross-sectional schematic view for explaining a structural example of a color filter substrate with a touch panel electrode of the present invention.
In the present invention, the touch panel electrode 20 is formed on one surface (the lower surface in the figure) of the transparent substrate 30, and the black matrix 3 and the color filter coloring layer 7 are formed on the other surface (the upper surface in the figure). In the method of forming the color filter including the touch panel electrode and the color filter, the inner marker 31 is formed inside the transparent substrate 30 using a laser light source, and the touch panel is used as an index by using the inner marker as an index. Electrode and color filter patterns are formed at appropriate positions.

As a means for providing the inner marker 31 inside the transparent substrate 30, a laser light source for processing, for example, an LD-excited solid laser such as an Nd: YAG laser or an Nd: YVO ₄ laser is generally used, and a fundamental wave having a wavelength of 1064 nm. Alternatively, a second harmonic (SHG laser) having a wavelength of 532 nm and a third harmonic (THG laser) having a wavelength of 355 nm that have been subjected to wavelength conversion by a nonlinear optical crystal can be used. In addition, a CO ₂ laser is also used for high output.

  The spot light from the laser light source is irradiated to the appropriate position of the transparent substrate as the object, and the irradiation position of the laser light is arbitrarily selected by changing the relative position of the light source and the substrate by driving the light source or the substrate Can be drawn. By the above method, an inner marker that defines a certain position from a specific point of the transparent substrate can be formed, and can also be defined as the origin in the transparent substrate.

  The details of the mechanism by which the inside of the transparent layer is processed by the laser light are unknown, but by adjusting the convergence angle and focus of the laser light of a specific wavelength according to the material and optical characteristics of the target, It is possible to create a damage or property value change region corresponding to “baking” at the depth point. When illumination light is given to the processing part after laser processing, it becomes a set of white spots due to light scattering and looks different from other surrounding areas, so that the whole can be captured as an image. In this processing method, since the processing is performed inside the transparent substrate, it is possible to obtain clean marking that does not generate any particles that often cause problems in the fine processing step.

  As the transparent substrate 30, a glass substrate excellent in transparency, flatness, and chemical resistance such as alkali-free glass is often used, and the thickness is often about 0.5 mm or 0.7 mm. Not.

  In addition, in the case of the capacitive projection type as the touch panel electrode 20, a complicated structure having a multilayer pattern may be required, and the first layer has a sandwich structure of, for example, molybdenum-aluminum-molybdenum. Using a metal pattern, accuracy control marks called verniers for positional accuracy management, which will be described later, are also formed at a plurality of locations, guaranteeing the absolute position of the layer on the substrate with respect to the inner marker, and the following lamination It is desirable to use for accuracy management with patterns. In the first layer on the color filter side, for the same reason as described above, it is desirable to form the pattern of the light-shielding black matrix 3 as the first layer and to form verniers at a plurality of locations at the time of formation.

  The method for manufacturing a color filter substrate with a touch panel electrode according to the present invention forms a color filter including the touch panel electrode 20, the black matrix 3, and the color filter coloring layer 7 using the inner marker 31 formed inside the transparent substrate 30 as an index. However, how to use the inner marker 31 as an index is not particularly limited. However, it is most desirable in terms of accuracy to form the touch panel electrode and the color filter by a known photolithography method, and it is desirable to align using an exposure machine with an alignment mechanism.

In order to prepare a photomask in advance, it is excellent in transparency and flatness with respect to the exposure wavelength, on a substrate such as glass or synthetic quartz that is not easily distorted or scratched, by a metal thin film having good light shielding properties and pattern forming suitability, A main pattern and alignment marks and vernier are formed in advance in an appropriate positional relationship. An inner marker 31 is formed in advance in the transparent substrate and a transparent substrate 30 to be processed having a photosensitive layer on at least the outermost surface is placed on an exposure stage. The photomask is used as an exposure mask, and usually several tens from the exposure surface. Proximity exposure is performed while maintaining an exposure gap of .about.hundreds of .mu.m. Of the photomask pattern, the positions where the alignment marks are projected onto the exposure surface are represented by 32 and 33 on the front and back surfaces of the transparent substrate 30 in FIG. That is, the substrate projection position 32 of the mark on the photomask to the touch panel electrode pattern side and the substrate projection position 33 of the mark on the photomask to the color filter pattern side are sequentially performed, but are collectively expressed in FIG. . By aligning the substrate projection position 32 and the substrate projection position 33 with the position of the substrate surface corresponding to the inner marker 31, the alignment mechanism of the exposure machine is used.

  FIG. 3 is a schematic diagram for explaining the alignment method using the alignment marks described above. As shown in the perspective view of (a), with a transparent substrate 30 as an exposure target, a photomask 40 is placed close to the exposure surface of the transparent substrate and exposed from the upper side of the figure. Use the alignment mechanism by observing in the direction of the dotted arrow in the figure. The reading camera 50 and its control mechanism (not shown) recognize the alignment mark 43 of the photomask 40 in the visual field indicated by the dotted circle in (b1) by image processing, and the visual field indicated by the dotted circle in (b2). The position of the inner marker 31 inside the transparent substrate 30 is adjusted so as to be recognized by the image processing, and both figures recognized by the image processing are superimposed so that the correct positional relationship is obtained on the monitor screen of the read image of (c). As described above, a signal for finely adjusting the positional relationship between the transparent substrate 30 and the photomask 40 is transmitted to finely move the mutual positional relationship between a substrate stage or a photomask holder (not shown).

  Needless to say, in order for the inner marker 31 to be recognized by the mark reading camera 50, it is necessary that the light shielding film does not cover the surface of the transparent substrate 30 in the camera field on the exposure surface side. Similarly to the conventional alignment mechanism, the reading position with respect to the alignment mark can be easily performed including angle correction on a plane by providing two positions for both the transparent substrate 30 and the photomask 40.

  Next, a position accuracy management method using an inner marker and a vernier in the present invention will be described with reference to FIG. FIG. 4 is a schematic diagram for explaining a position accuracy management method using vernier.

  As described above, the main pattern 35 formed on the front surface of the transparent substrate 30 is multi-layered on both the front and back surfaces of the transparent substrate 30 and needs to be aligned at the center position or the average position between the respective layers. At the same time, if the change in the total pitch due to expansion / contraction of the substrate at the time of exposure is not constant, there is a problem that an interlayer alignment failure occurs in a part of the pattern, so quality control over the entire surface of the substrate is important. Become. In order to detect and avoid the above-described defect situation during the process and to easily check the finished quality of the product to prevent the shipment of defective products, the position accuracy management pattern set 36 by vernier is used for the transparent substrate 30. It is desirable to provide at a plurality of locations.

  The position accuracy management pattern set 36 by vernier is shown in the area surrounded by the dotted circles at the four corners of the substrate in the figure, but is not limited to this, and the effective area of the main pattern 35 is removed and provided arbitrarily. Can do. The position accuracy management pattern set 36 by the vernier is, for example, a combination of a vernier 37 inside the substrate and a vernier 38 on the surface of the substrate, and can be used for alignment in the same process as the reading method at the time of alignment by the alignment mark. . However, in that case, the region of the position accuracy management pattern set 36 by vernier on the exposure surface of the transparent substrate at the time of alignment needs to be at least semi-transmissive. In addition, as a mark representative of the pattern actually printed by the exposure machine, the degree of alignment between the vernier 38 on the surface of the substrate and the vernier 37 inside the substrate provided in advance, which should be positioned immediately below, is shown in each substrate. By verifying the position, quality control over the entire surface of the substrate becomes possible. When the position accuracy management pattern set 36 by vernier is used only for the purpose of the latter post-verification, a light shielding film can be previously present in the corresponding area of the exposure surface of the transparent substrate.

  Explaining with the enlarged view of the position accuracy management pattern set 36 by the vernier shown in FIG. 4, the position accuracy management pattern set 36 by the vernier at a specific position in the substrate is obtained by the mark reading camera 50 or after the process, or It can be taken out from the process and separately observed with a microscope. Next, the planar distances a, b, c and d between the vernier 37 inside the substrate as a kind of inner marker and the vernier 38 formed on the surface of the substrate are measured with a video micrometer from the read observation image. be able to. Ideally, a = b and c = d at each position including the four corners of the substrate. However, in accordance with the allowable limit of the positional accuracy and total pitch accuracy of the photomask pattern transfer onto the substrate, And the control value of the quality control standard including the shipping standard can be determined.

If the target value or the management value is A μm in the X direction and B μm in the Y direction, the management values A and B are set according to the following two formulas:
| A−b | ≦ A (1)
| C−d | ≦ B (2) (A and B are arbitrary positive numbers)
Thus, the pattern formation quality on both the front and back surfaces of the transparent substrate 30 can be centrally managed. That is, management is performed based on (1) the absolute value of the difference between a and b does not exceed A, and (2) the absolute value of the difference between c and d does not exceed B. Note that A and B can be set to the same value.

As described above, according to the present invention, it is possible to easily provide accurate alignment and provide a color filter substrate with a touch panel electrode. However, the present invention is not limited to a color filter substrate with a touch panel electrode, but on both front and back surfaces of a transparent substrate. The present invention can be similarly applied to other cases where a plurality of patterns are formed. That is, a transparent substrate having an inner marker characterized in that the inner marker is provided inside the transparent substrate and the inner marker can be used uniformly as an alignment index for a plurality of patterns formed on both the front and back surfaces of the substrate. Can be provided.
Further, by using the transparent substrate having the inner marker, the color filter substrate with a touch panel electrode can be easily provided with high quality.

DESCRIPTION OF SYMBOLS 1 ... 1st transparent substrate 2 ... 2nd transparent substrate 3 ... Black matrix 4 ... Insulating layer 5 ... Circuit for liquid crystal drive (TFT element and wiring layer)
6 ... Passivation layer 7 ... Color filter coloring layer 8 ... Pixel electrode 9 ... Liquid crystal alignment film 10 ... Liquid crystal display cell 11 ... Liquid crystal layer 12 ... Counter electrode 13 ... Polarizing layer 14 ... Backlight illumination light 15 ... Display light 20 ... Touch panel electrode 30 ... Transparent substrate 31 ... Inner marker 32 ... Substrate projection position of mark on photomask (touch panel electrode) Pattern side)
33 ... Substrate projection position of mark on photomask (color filter pattern side)
35 ... Main pattern formed on substrate surface 36 ... Vernier position accuracy control pattern set 37 ... Vernier 38 inside substrate ... Vernier 40 on substrate surface ... Photo mask 43 ... Photo Mask alignment mark 50 ... Mark reading camera

Claims (5)

  A method of forming a touch panel electrode on one surface of a transparent substrate and forming a color filter on the other surface, prior to the formation of the touch panel electrode and the color filter, using a laser light source, A method for producing a color filter substrate with a touch panel electrode, wherein a marker is formed and a touch panel electrode and a color filter are formed using the inner marker as an index.   2. The method for manufacturing a color filter substrate with a touch panel electrode according to claim 1, wherein an alignment mark and a position accuracy management vernier are provided as inner markers at a plurality of locations.   The method for producing a color filter substrate with a touch panel electrode according to claim 1, wherein the color filter substrate is formed by photolithography using an inner marker.   A transparent substrate is a glass substrate, The color filter substrate with a touch-panel electrode manufactured by the manufacturing method in any one of Claims 1-3 characterized by the above-mentioned.   A transparent substrate having an inner marker, wherein the transparent substrate has an inner marker, and the inner marker can be used uniformly as an alignment index for a plurality of patterns formed on both front and back surfaces of the substrate.