JP2006106087A - Method for manufacturing transflective display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing a transflective display element with excellent visibility by reducing occurrence of air bubbles in sticking of a base layer. <P>SOLUTION: The method for manufacturing the transflective display element, having a transmissive region and a reflective region arranged inside a pixel, is provided with: a sticking step to stick the light transmitting base layer 104 with an uneven surface formed on the surface thereof to a rectangular transparent substrate 1000; and a film forming step to form a reflection diffusing film 105 on a region of the uneven surface corresponding to the reflective region. In particular, the sticking step is conducted by sticking the base layer 104 to the transparent substrate 1000 while pressing the surface of the base layer 104 by moving a pressing region from any one of corners (for example, the corner E) of the transparent substrate 1000. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a transflective display element.

Conventionally, liquid crystal display elements have been used as display means for mobile phones and the like.
For example, a reflective liquid crystal display element performs display by reflecting light incident from the outside toward the front side of the liquid crystal display element. In a reflective liquid crystal display element, in order to obtain a bright display by efficiently using external light, a structure for emitting uniform light in a direction perpendicular to the display screen with respect to incident light from all angles is required.

  Conventionally, for example, the following manufacturing method of a reflective liquid crystal display element has been proposed. That is, after the base layer (thermosetting / photosensitive resin) is attached to the substrate, the thermosetting / photosensitive resin is photocured by exposing the thermosetting / photosensitive resin, and the inclination angle is less than a predetermined angle. A plurality of irregularities are formed. Then, after baking the base layer, a diffuse reflection film is formed on the uneven surface using a metal thin film made of aluminum or silver. In addition, since the metal thin film is formed on the uneven surface, the metal thin film has a diffusion function in addition to the reflection function (for example, Non-Patent Document 1).

  However, in recent years, in addition to the light reflection function of the reflective liquid crystal display element, a cellular phone or the like has a light transmission function for transmitting the light of the backlight arranged on the back side of the liquid crystal display element to the front side of the liquid crystal display element. There has been a demand for a transflective liquid crystal display element having the same. The transflective liquid crystal display element has, for example, a reflective region that reflects light input using a reflective film for each pixel and a transmissive region that transmits light input without a reflective film. There is one in which a region and a transmission region are each formed as a continuous region (for example, Patent Document 1).

Here, when the technique described in Non-Patent Document 1 is also applied to the technique described in Patent Document 1 (semi-transmissive liquid crystal display element), for example, the base layer described in Non-Patent Document 1 is light-transmitted. A method of additionally forming a transmissive region by removing a part of the diffuse reflection film (metal film) formed on the concavo-convex surface of the base layer surface for each pixel is considered.
Tsuruoka Yasuo, Shimazaki Toshikatsu, Yoshida Ken, “Reflective Base Film Material for Reflective Color LCD”, Hitachi Chemical Technical Report, Hitachi Chemical Co., Ltd., January 2002, No. 38, p. 15-18 JP 2001-281648 A (FIG. 1)

However, the inventor has discovered that when the base layer and the substrate are bonded together, air is trapped between the base layer and the substrate, resulting in bubbles.
In addition, when a bubble exists between the base layer and the substrate in the transmissive region, light passes through the base layer in the transmissive region, so that the bubble looks like a pinhole, for example, and the visibility of the liquid crystal display element is reduced. It was found that it would greatly decrease.
The present invention has been made in order to solve such problems, and reduces the generation of bubbles generated when a base layer is attached, and efficiently produces a transflective display element with good visibility. An object is to provide a method for manufacturing a display element.

A method of manufacturing a transflective display device according to the present invention is a method of manufacturing a transflective display device in which a transmissive region and a reflective region are provided in a pixel, and a light-transmitting underlayer having an uneven surface is provided. A step of attaching to a rectangular light-transmitting substrate, and a step of forming a reflective diffusion film on the uneven surface and corresponding to the reflective region. The base layer is pressed and pasted while moving the pressing region from any one corner of the substrate.
By such a method, it is possible to provide a method for manufacturing a transflective display element that can reduce the generation of bubbles generated when the base layer is attached and can efficiently manufacture a transflective display element with high visibility.

  Further, in the attaching step, the base layer may be pressed and attached while moving the pressing region from any one corner of the substrate to a diagonal corner.

  Moreover, you may perform the said sticking process using a roller.

  According to the present invention, it is possible to provide a method for manufacturing a transflective display element that can reduce the generation of bubbles generated when the base layer is attached and can efficiently manufacture a transflective display element with high visibility.

Embodiment 1 of the Invention
Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a transflective liquid crystal display element.
In FIG. 1, a transflective liquid crystal display element 10 is configured by sandwiching a liquid crystal 103 between two transparent substrates 101 and 102. The transparent substrates 101 and 102 are formed in a rectangular shape using, for example, light transmissive glass, polycarbonate, acrylic resin, or the like.
On the front surface of the transparent substrate 102 of the liquid crystal display element 10, a base layer 104, a reflection diffusion film 105, a color filter layer 106, a planarization film 106a, a transparent electrode 107, and an alignment film 108 are sequentially stacked.

The underlayer 104 is an underlayer for forming the reflective diffusion film 105, and is formed of a light transmissive thermosetting / photosensitive material. The ground layer 104 has a concavo-convex surface 104a formed with a plurality of concavo-convex surfaces on the front surface and a flat surface on the back surface.
The reflection diffusion film 105 is formed by depositing a metal having high reflectivity such as aluminum or silver on the surface of the base layer 104 by a metal sputtering method or a vacuum evaporation method. The reflective diffusion film 105 is removed at a portion corresponding to the transmissive region 150 so that the transmissive region 150 and the reflective region 160 are formed in the pixel.

  The transparent electrode 107 is formed of, for example, a transparent conductive thin film (ITO: Indium Tin Oxide) by photolithography. The alignment film 108 is formed of, for example, an organic thin film such as a polyimide thin film that is a polymer material, and plays a role of aligning the molecules of the liquid crystal 103 in a predetermined direction.

  A transparent electrode 109 and an alignment film 110 are laminated on the back surface of the transparent substrate 101 of the liquid crystal display element 10. The transparent electrode 109 is formed so as to be orthogonal to the transparent electrode 107. The polarizing plates 111 and 112 are optical members having a function of transmitting only a specific polarization component with respect to incident light. The polarizing plate 111 is attached to the front surface of the transparent substrate 101 via the optical compensation plate 115. The polarizing plate 112 is attached to the back surface of the transparent substrate 102 via the optical compensation plate 116. The spacers 113 are resin particles that control the height (cell gap) of the liquid crystal 103 between the transparent substrates 101 and 102, and are spread over the entire range between the transparent substrates 101 and 102. The sealant 114 is an adhesive for bonding the rectangular transparent substrates 101 and 102 around.

  As shown in FIG. 1, in the transmissive region 150, light incident from the back side of the liquid crystal display element 10 (for example, backlight light) passes along the path indicated by the arrow M. Is transmitted to the front side of the screen. Further, in the reflection region 160, light (for example, natural light) incident from the front surface of the liquid crystal display element 10 is diffusely reflected by the diffuse reflection film 105 along the path indicated by the arrow N, and the front side of the liquid crystal display element 10. Is injected into.

Next, a method for manufacturing the transflective liquid crystal display element 10 according to the present invention will be described with reference to the drawings.
FIG. 2 is a diagram showing a method for manufacturing a transflective liquid crystal display element according to the present invention.
In FIG. 2, the integrated base film 104b and base layer 104 are attached to the front surface of the cleaned transparent substrate 102 by thermocompression bonding while removing the protective sheet 104c (FIG. 2 (a)).
Specifically, the base layer 104 attachment process corresponding to FIG. 2A will be described with reference to FIGS. 3 and 4.

FIG. 3 is a diagram for explaining a general bonding process of the underlayer in order to clarify the difference from the present invention.
In FIG. 3, an example in which the transparent substrate 102 is multi-faceted will be described. A mother substrate (transparent substrate) 1000 arranges a plurality of transparent substrates 102. The underlayer 104 is formed in a rectangular shape that is smaller than the outer shape of the mother substrate 1000. In addition, the base layer 104 is attached to the inner side of the outer periphery of the mother substrate 1000.

The base layer 104 is attached to the mother substrate 1000 by thermocompression using the roller 200 in an environment at a temperature of 100 ° C. to 140 ° C. At that time, the mother substrate 1000 is preheated to about 50 ° C.
As shown in FIG. 3A, the roller 200 is arranged in parallel with one side (for example, the side EF) of the rectangular mother substrate 1000. While moving the pressing area (the contact area between the roller 200 and the base film 104b) from the side EF toward the side GH (the B direction in FIG. 3A), the roller 200 moves through the base film 104b. The base layer 104 is pressed to attach the base layer 104 and the mother substrate 1000.
As shown in FIG. 3B, the protective film 104c is peeled off in accordance with the movement of the roller 200.

  In this case, after the protective film 104c is peeled off, when the base layer 104 is first pressed against the mother substrate 1000 by the roller 200 in the vicinity of the side EF, there is air between the mother substrate 1000 and the base layer 104 in the pressing region. The trapped air bubbles are generated between the mother substrate 1000 and the base layer 104. In FIG. 3A, the region where bubbles are generated is such that when L1 = about 20 mm to about 30 mm, bubbles are generated in a region corresponding to the length of EF × L1 (shaded portion in FIG. 3A). At this time, for example, if the mother substrate 1000 has a size of, for example, 480 mm × 360 mm, and the number of the transparent substrates 102 is 10 (one row) × 10 (one line), the number of the transparent substrates 102 is at least 10 on the transparent substrate 102. In this case, bubbles are generated in a part of the display area. Therefore, the general pasting process of the underlayer shown in FIG. 3 is too inefficient to obtain more transflective liquid crystal display elements with no air bubbles and good visibility.

Therefore, the base layer 104 is attached by the method shown in FIG.
FIG. 4 is a diagram for explaining the base layer pasting process of the transflective liquid crystal display device according to the present invention.
4 differs from FIG. 3 in the way the roller 200 moves. 4 has a configuration similar to that of FIG. 3B.
In FIG. 4, the base layer 104 is pasted from any one of the corners of the mother substrate 1000 (the corner E in FIG. 4 includes the corner peripheral portion) to all the sides (the EF side and the FG in FIG. 4). The base layer 104 is pressed by the roller 200 through the base film 104b while moving the pressing region (the contact region between the roller 200 and the base film 104b) in a direction that is not parallel to the side, the GH side, and the HE side. Then, the base layer 104 and the mother substrate 1000 are attached.
Here, the moving direction of the roller 200 is a direction perpendicular to the rotation axis of the roller 200. In addition, when the base layer 104 is first pressed by the roller 200, the rotation axis of the roller 200 is set to be oblique with respect to the side EF, that is, not to be parallel, and the moving direction of the roller 200 is , It is assumed that the direction is oblique to the side EF, that is, the direction is not parallel to the side EF.
Note that the base layer 104 is cut to be smaller than the outer shape of the mother substrate 1000.
Further, instead of the roller 200, a non-rotating member may be used.

In this case, after the protective film 104c is peeled off, when the base layer 104 is first pressed against the mother substrate 1000 with the roller 200 at the corner E, air is interposed between the mother substrate 1000 and the base layer 104 in the pressing region. Is trapped and bubbles are generated. The region where bubbles are generated is different from the general pasting process of the underlayer 104, and is a triangular region around the corner E where L2 = about 20 mm to about 30 mm shown in FIG. 4 (shaded portion in FIG. 4). It becomes only. At this time, since the generation of bubbles can be suppressed only to the triangular region around the corner E, for example, 10 (one row) × 10 (one row) transparent substrates 102 are formed on the mother substrate (transparent substrate) 1000. Assuming that multiple surfaces can be obtained, the number of transparent substrates 102 in which bubbles are generated in a part of the display area can be reduced to about one or two. As described above, the generation of bubbles generated when the base layer 104 is attached can be reduced.
In addition, preferably, the base film 104b is moved using the roller 200 while moving the pressing region from the periphery of any corner (for example, the corner E) of the mother substrate 1000 toward the diagonal corner (for example, the corner H). Then, the base layer 104 is pressed to attach the base layer 104 and the mother substrate 1000 to each other.
Further, after the pressing operation of the roller 200 is completed, the pressing force is released, but bubbles may also be generated at this time. If the end point of the press is a corner, there is an advantage that the bubble generation area at the end point is reduced.

In FIG. 2, next, the base film 104b is photocured by irradiating the base film 104b with light with the base film 104b and the base layer 104 attached to the surface of the mother substrate 1000 (see FIG. 2). FIG. 2 (b)). At this time, the base layer 104 is also crosslinked.
Next, the photocured base film 104b is peeled off to expose the uneven surface 104a formed on the surface of the base layer 104 (FIG. 3C).
Next, the base layer 104 is baked (baked) at 200 ° C. or more and around 250 ° C. or less for about 30 minutes or more ((d) in the figure). The purpose of firing is to increase the crosslinking density by further curing after the photocuring of the underlayer 104.
Next, a reflective diffusion film 105 such as a silver thin film or an aluminum thin film is formed on the surface of the concavo-convex surface 104a formed on the surface of the underlayer 104 by, for example, a metal sputtering method or a vacuum evaporation method ((e) in the figure). .
Next, the portion of the reflective diffusion film 105 corresponding to the transmission region 150 is removed by, for example, etching ((f) in the figure).

Next, a color filter layer 106, a planarizing film 106a, a transparent electrode 107, and an alignment film 108 are formed on the surface of the reflective diffusion film 105. Further, the transparent electrode 109 and the alignment film 110 are formed on the back surface of the transparent substrate 101.
Next, the transparent substrate 101 and the transparent substrate 102 provided with the transparent electrodes 107 and 109, respectively, are dispersed on the entire surface of the transparent substrate 101 or 102, and then the transparent substrates 101 and 102 are bonded together with a sealant 114. . Then, after injecting the liquid crystal 103 from the liquid crystal injection port (not shown), sealing the liquid crystal injection port, and further attaching the optical compensators 115 and 116 and the polarizing plates 111 and 112 to the transparent substrates 101 and 102, The liquid crystal display element 10 is completed.
By the manufacturing method as described above, the generation of bubbles generated when the base layer 104 is attached can be reduced, and a transflective display element with high visibility can be efficiently manufactured.

It is a figure which shows the cross section of a transflective liquid crystal display element. It is a figure which shows the manufacturing method of the transflective liquid crystal display element which concerns on this invention. It is a figure explaining the general affixing process of a base layer. It is a figure explaining the affixing process of the base layer of the transflective liquid crystal display element which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Liquid crystal display element, 101,102 Transparent substrate, 103 Liquid crystal, 104 Underlayer, 104a Irregular surface, 104b Base film, 104c Protective sheet, 105 Reflection diffusion film, 106 Color filter layer, 107, 109 Transparent electrode, 108, 110 Orientation Membrane, 111, 112 Polarizing plate, 200 roller, 1000 Mother substrate (transparent substrate).

Claims (3)

A method of manufacturing a transflective display element in which a transmissive region and a reflective region are provided in a pixel,
An attaching step of attaching a light-transmitting underlayer having an uneven surface to a rectangular light-transmitting substrate;
And a film forming step of forming a reflection diffusion film on the uneven surface and corresponding to the reflection region,
The method for manufacturing a transflective display element, wherein the attaching step comprises pressing the base layer while moving the pressing region from any one corner of the substrate.   The said affixing process presses and affixes the said foundation | substrate layer, moving a press area | region to the direction of the corner | angular on a diagonal line from the corner of any one of the said board | substrates, It is characterized by the above-mentioned. Manufacturing method of transflective display element.   The method of manufacturing a transflective display device according to claim 1, wherein the attaching step is performed using a roller.

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