JP2006163038A - Manufacturing method of particle movement type display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a particle transfer type display element with which the frequency of photolithography is reduced, and patterning of a three-dimensional structure is made easy. <P>SOLUTION: Partition walls 3 disposed in a gap between a first substrate 1 and a second substrate 2 disposed at a prescribed interval from the first substrate 1 are formed by a partition wall forming step. The frequency of photolithography is reduced by obliquely depositing an electrode layer on the partition walls 3 to coat the partition walls 3 and forming a second electrode 7 to be disposed on the partition wall side by an electrode forming step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a particle movement type display element that performs display by moving particles.

  2. Description of the Related Art In recent years, research on particle moving display devices that perform display based on moving particles by applying voltage has been actively conducted. Among them, the electrophoretic display device has a particularly high degree of attention.

  The electrophoretic display device includes a pair of substrates arranged in a state where a predetermined gap is opened, particles arranged in a gap between the substrates, and a pair of electrodes arranged so as to face the gap. The electrophoretic display element has a display contrast higher than that of a liquid crystal display element, a wide viewing angle, a memory property for display, a backlight and a polarizing plate are unnecessary, etc. It has various features.

  As a manufacturing method of such an electrophoretic display element, generally, as with a liquid crystal display element or the like, display of various electrodes, insulating layers, partitions, etc. is generally performed by repeating film formation and photolithography on a substrate. There is one that forms a part (see Patent Document 1).

JP-A-9-101510

  By the way, in such a conventional method for manufacturing an electrophoretic display element, the number of times of photolithography greatly affects the manufacturing cost. Therefore, it is required to reduce the number of times as much as possible. However, it is usually difficult to reduce the number of times that the film patterning by one photolithography is necessary for one film formation.

  Further, when the surface of an object having a three-dimensional structure is covered with an electrode layer, patterning by photolithography is difficult.

  Therefore, the present invention has been made in view of such a situation, and an electrophoretic display element (particle movement type display element) that can reduce the number of times of photolithography and can easily pattern a three-dimensional structure. ) Is intended to provide a manufacturing method.

  As in the present invention, the first and second substrates arranged with a gap therebetween, the partition wall holding the gap constant and partitioning the gap to define pixels, and the particles arranged in the gap In the method for manufacturing a particle movement type display device, comprising: a first electrode disposed in a pixel along the first substrate or the second substrate; and a second electrode disposed on a side surface of the partition wall. A partition formation step of forming the partition on one substrate or the second substrate; and an electrode formation step of forming the second electrode by obliquely depositing an electrode layer on the partition to cover the partition. It is characterized by.

  As in the present invention, the second electrode on the partition wall side is formed by obliquely depositing an electrode layer on the partition wall to cover the partition wall, thereby reducing the number of times of photolithography. Thereby, the manufacturing cost can be reduced. Further, by controlling the position where the electrode layer is formed while changing the deposition angle, patterning of a three-dimensional structure called a partition becomes easy.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of an electrophoretic element manufactured by an electrophoretic display element manufacturing method which is an example of a method for manufacturing a particle movement type display element according to an embodiment of the present invention. The element is arranged with a predetermined gap from the first substrate 1, the second substrate 2 arranged on the observer side, and the gap between the first and second substrates 1 and 2 is constant. A partition wall 3 that holds and partitions the gaps to define the pixels 4a and 4b, particles 9 disposed in the gaps, a first electrode 5 disposed in the pixels 4a and 4b along the first substrate 1, and a partition wall 3 and a second electrode 7 formed so as to cover the surface of 3.

  Here, the first electrode 5 also functions as a reflective layer. A scattering layer 6 for scattering incident light is disposed at the center of the pixels 4a and 4b. In the present embodiment, the particles 9 are charged electrophoretic particles, and the charged electrophoretic particles 9 are dispersed in the insulating liquid 8.

  Here, the display in the electrophoretic display element configured as described above is performed by applying a voltage between the first electrode 5 and the second electrode 7 to move the charged electrophoretic particles 9 between both electrodes. For example, as shown in the left pixel 4a in FIG. 1, the color of the charged electrophoretic particles 9 can be displayed by arranging the charged electrophoretic particles 9 on the first electrode 5, as shown in the right pixel 4b in FIG. In addition, by collecting the charged electrophoretic particles 9 on the second electrode 7 side, incident light can be reflected by the first electrode surface and scattered by the scattering layer 6 to display white.

  In order to perform black and white display using such an electrophoretic display element, the charged electrophoretic particles 9 may be black, and the charged electrophoretic particles 9 may be driven by a shutter. 9 may be colored or other members may be appropriately colored. For example, color display is possible by using black electrophoretic particles as the electrophoretic particles 9 and forming a color filter layer on the first electrode surface.

  Next, a method for manufacturing such an electrophoretic display element will be described.

  First, as shown in FIG. 2A, a switching element 10 such as a thin film transistor (TFT) and a wiring (not shown) are formed on a first substrate, and then each switching element 10 is interposed via an insulating layer. The first electrode 5 is formed. Next, the scattering layer 6 is formed on the first electrode, and the partition wall 3 is disposed above the scattering layer 6.

  Next, as shown in FIG. 2B, the second electrode 7 is formed by vapor-depositing metal particles on the surface of the partition 3 formed on the first substrate. In addition, this vapor deposition is performed from the diagonal direction with respect to the 1st board | substrate 1, as shown in FIG. Here, the partition walls 3 are installed at equal intervals on the first substrate. When vapor deposition is performed in such an oblique direction, each partition wall 3 creates a shadow on the vapor deposition source 11. No vapor deposition is deposited on the shadowed portion of the first substrate.

  Therefore, in the case of such vapor deposition, by appropriately taking the vapor deposition direction, it is possible to almost eliminate the deposition of the vapor deposition material on the first electrode formation surface on the first substrate, and the vapor deposition layer, that is, the electrode layer 7A is separated from the partition wall. It is possible to form a film only on the side surface 3.

  In addition, since it is desirable that the vapor deposition particles 12 reach the first substrate 1 linearly from the vapor deposition source 11, this vapor deposition is preferably performed by a vapor deposition method having a high degree of vacuum such as an electron beam vapor deposition method. . Further, when the vapor deposition layer (electrode layer 7A) is formed on both surfaces of the partition wall 3, vapor deposition is performed sequentially or simultaneously from the opposite direction, and the partition wall 3 is formed so as to surround the pixel 4. In this case, vapor deposition is performed sequentially or simultaneously from different directions.

  Alternatively, the vapor deposition particles 12 may be used as a convergent beam to form a film on the side wall of the partition wall, and a shutter or a baffle may be installed until the vapor deposition particles 12 reach the first substrate 1 from the vapor deposition source 11. Also good. Furthermore, the formation position of the 2nd electrode 7 with respect to the partition 3 can be adjusted with the vapor deposition angle at the time of electrode layer 7A film-forming. For example, as shown in FIG. 4, when it is desired to form the second electrode 7 only on the upper part of the partition wall, the deposition angle is made shallower. These film forming positions are determined by element characteristics.

  Next, after the electrode layer is formed by such vapor deposition, the entire surface of the electrode layer 7A is etched, and after this step, the surface of the partition wall 3 is covered with an insulating layer. Next, as shown in FIG. 2 (c), the pixels 4a and 4b are filled with the insulating liquid 8 and the charged electrophoretic particles 9, and then the pixels 4a and 4b are sealed by the second substrate 2, and thereafter A voltage application circuit (not shown) is connected to form a display element.

  In the present embodiment, the first substrate 1 and the second substrate 2 are made of plastic film such as polyethylene terephthalate (PET), polycarbonate (PC), polyethersulfone (PES), glass, quartz or the like. Can be used. Further, when the electrophoretic display element is of a reflective type, it is necessary to use a transparent material for the second substrate 2 and the base material arranged on the viewer side, but for the other substrate 1, polyimide is used. Colored ones such as (PI) may be used.

  Further, when the first electrode 5 is also used as a reflective layer as in the present embodiment, the first electrode 5 is preferably formed of a highly light reflective material such as silver or Al. The scattering layer 6 may be a resin in which fine particles having different refractive indexes are dispersed in a resin. When the scattering layer 6 is not provided, the first electrode 5 is provided with irregularities to scatter reflected light. You may make it make it.

  As the insulating liquid 8, it is preferable to use a nonpolar solvent such as isoparaffin, silicone oil, xylene, and toluene, which is transparent. As the electrophoretic particles 9, it is preferable to use a material that is colored and has good positive or negative charge characteristics in the insulating liquid 8, for example, various inorganic pigments, organic pigments, carbon black, It is preferable to use a resin containing them. In addition, although the particle diameter of a particle | grain can use the thing of about 0.01 micrometer-50 micrometers normally, Preferably it is good to use a thing of about 0.1-10 micrometers.

  In addition, a charge control agent for controlling and stabilizing the charge of the charged electrophoretic particles 9 may be added to the insulating liquid 8 or the charged electrophoretic particles 9. Examples of the charge control agent include monoazo dyes. Metal complex salts, salicylic acid, organic quaternary ammonium salts, nigrosine compounds, and the like may be used.

  Further, in the insulating liquid 8, a dispersing agent for preventing aggregation of the charged electrophoretic particles and maintaining a dispersed state may be added. Examples of the dispersing agent include calcium phosphate and magnesium phosphate. Phosphoric acid polyvalent metal salts, carbonates such as calcium carbonate, other inorganic salts, inorganic oxides, or organic polymer materials can be used. Further, the insulating liquid 8 and the charged electrophoretic particles 9 may be arranged in each of the pixels 4a and 4b after being microencapsulated. In that case, one or more microcapsules are arranged in each pixel.

  For the member of the partition 3, the same material as the first substrate 1 may be used, or a photosensitive resin such as acrylic may be used. In addition, any method may be used for forming the partition wall 3, for example, by applying a photosensitive resin layer, and then performing exposure and wet development, or a method of bonding a separately created barrier, or a printing method. A forming method or the like can be used.

  As described above, the second electrode 7 on the partition wall side is formed by covering the partition wall 3 by obliquely vapor-depositing an electrode layer on the partition wall 3 as in the present embodiment. The number of lithography can be reduced, and the manufacturing cost can be reduced. In addition, by controlling the position where the electrode layer is formed while changing the deposition angle, patterning of a three-dimensional structure called a partition structure is facilitated.

  Examples of the present invention will be described below.

Example 1
In this example, the electrophoretic display element having the structure shown in FIG. 1 was manufactured as follows.

  First, the first electrode 5 is formed on the first substrate 1 on which the thin film transistor (TFT) 10 and wirings are formed. Here, the first electrode 5 is formed by depositing an aluminum film, forming a resist pattern by photolithography, and etching the exposed surface. The first electrode 5 also serves as a reflective layer, and is arranged at the center of each pixel 4. After removing the resist, the scattering layer 6 is formed above the first electrode 5. The scattering layer 6 is made of an acrylic resin in which titanium oxide fine particles are dispersed.

  Next, in the partition formation step, the partition 3 is disposed at the boundary between the pixels 4 a and 4 b on the first substrate 1. The width of the partition 3 is 5 μm and the height is 15 μm.

  Next, in the electrode forming step, an electrode layer (metal layer) is formed on the surface of the partition 3. For this film formation, an electron beam evaporation method is used, and the film formation is performed obliquely with respect to the first substrate surface. Thereby, the vapor deposition particles 12 evaporated from the vapor deposition source 11 (see FIG. 3) hit only the side surfaces of the partition walls 3 and are deposited. And while performing this vapor deposition from 4 directions, the 2nd electrode 7 is formed in the partition surface by the process of etching the whole surface of an electrode layer.

  Next, a transparent insulating layer is formed on the surface of the partition wall having the second electrode 7 formed on the surface in this way. Thereafter, each pixel is filled with an insulating liquid 8 and charged electrophoretic particles 9, and each pixel 4 is sealed with the second substrate 2. And the voltage application circuit was connected to the particle movement type display element formed in this way, and it was set as the electrophoretic display device.

  By the above manufacturing method, the electrophoretic display element and the electrophoretic display element device can be manufactured stably and at a relatively low cost.

(Example 2)
As in Example 1, the first substrate 1 on which the thin film transistor (TFT) 10, wiring, and the like, the first electrode 5, the scattering layer 6, and the partition 3 are formed is manufactured.

  Next, in the electrode forming step, an electrode layer (metal layer) is formed on the surface of the partition 3. For this film formation, an electron beam evaporation method is used, and the film formation is performed at a lower angle than the oblique direction shown in FIG. Thereby, the vapor deposition particles 12 evaporated from the vapor deposition source 11 hit only the upper part of the partition wall 3, that is, the second substrate side, and are deposited (see FIG. 4). And while performing this vapor deposition from 4 directions, the 2nd electrode 7 is formed in the partition surface by the process of etching the whole surface of an electrode layer.

  Next, a transparent insulating layer is formed on the surface of the partition wall having the second electrode 7 formed on the surface in this way. Thereafter, each pixel is filled with an insulating liquid 8 and charged electrophoretic particles 9, and each pixel 4 is sealed with the second substrate 2. And the voltage application circuit was connected to the particle movement type display element formed in this way, and it was set as the electrophoretic display device.

  By the above manufacturing method, the electrophoretic display element and the electrophoretic display element device can be manufactured stably and at a relatively low cost.

  In the above description, the case where the first electrode 5 and the partition 3 are provided on the first substrate has been described. However, the present invention is not limited to this, and the first electrode 5 and the partition 3 are provided on the second substrate. You may make it provide the partition 3 grade | etc.,.

The figure which shows the structure of the electrophoretic element manufactured by the manufacturing method of the electrophoretic display element which is an example of the manufacturing method of the particle migration type display element which concerns on embodiment of this invention. The figure for demonstrating the manufacturing method of the said electrophoretic display device. The figure explaining the electrode formation process in the manufacturing method of the said electrophoretic display element. The figure explaining the other example of the electrode formation process in the manufacturing method of the said electrophoretic display element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 2nd board | substrate 3 Partition 4a, 4b Pixel 5 1st electrode 7 2nd electrode 8 Insulating liquid 9 Charged electrophoretic particle 11 Deposition source 12 Deposition particle

Claims (7)

First and second substrates arranged with a gap; partition walls that hold the gap constant and partition pixels to define pixels; particles arranged in the gap; and the first substrate or In a method for manufacturing a particle movement type display device, comprising: a first electrode disposed in a pixel along the second substrate; and a second electrode disposed on a side surface of the partition wall.
A partition formation step of forming the partition on the first substrate or the second substrate;
An electrode forming step of forming the second electrode by obliquely depositing an electrode layer on the partition wall to cover the partition wall;
A method for producing a particle movement type display element, comprising:   The method for manufacturing a particle movement type display element according to claim 1, wherein an evaporation angle with respect to the partition wall is variable.   3. The method of manufacturing a particle movement type display element according to claim 1, wherein the oblique vapor deposition is sequentially performed on the partition walls from different directions.   3. The method of manufacturing a particle movement type display element according to claim 1, wherein the oblique vapor deposition is simultaneously performed on the partition walls from different directions.   5. The method for manufacturing a particle movement type display device according to claim 1, wherein the electrode forming step includes a step of etching the entire surface of the electrode layer covering the partition wall. 6.   The particle moving display element according to claim 1, wherein the particle is a charged electrophoretic particle, and has a step of arranging the charged electrophoretic particle and an insulating liquid in the gap. Production method. 6. The particle according to claim 1, wherein the particle is a charged electrophoretic particle, and has a step of arranging a microcapsule containing the charged electrophoretic particle and an insulating liquid in the gap. A method for manufacturing a movable display element.

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