JP5549523B2 - Electrophoretic display device manufacturing method, electrophoretic display device, and electronic apparatus - Google Patents

Description

  The present invention relates to a method for manufacturing an electrophoretic display device, an electrophoretic display device, and an electronic device.

  As an electrophoretic display (EPD), a space between two substrates arranged opposite to each other is partitioned for each pixel by a partition, and an electrophoretic dispersion is sealed between the two substrates for each pixel. Is known (see, for example, Patent Documents 1 and 2). Such an electrophoretic display device is generally prepared separately from a substrate on which a circuit for driving a plurality of pixel electrodes of two substrates is formed (hereinafter referred to as “circuit substrate” as appropriate). It is manufactured by pasting together the partition walls.

JP 2010-20003 A JP 2010-44114 A

  However, in the manufacturing method in which the circuit substrate and the partition wall are bonded together as described above, the pixel electrode formed on the circuit substrate and the partition wall need to be aligned (that is, aligned), and the pixel electrode and the partition wall are misaligned. There is a technical problem that may occur. When such misalignment occurs, the display performance of the electrophoretic display device may be degraded.

  The present invention has been made in view of the above-described problems, for example. An electrophoretic display device manufacturing method and an electrophoretic display device capable of preventing the occurrence of misalignment between a pixel electrode and a partition, and such an electrophoresis. It is an object to provide an electronic device including a display device.

  In order to solve the above problems, a method of manufacturing an electrophoretic display device according to the present invention includes a pixel electrode forming step of forming a plurality of pixel electrodes from a non-translucent material on a translucent substrate; A resist film forming step of forming a resist film made of a negative resist so as to cover the plurality of pixel electrodes, and a back surface side of the substrate opposite to the surface on which the plurality of pixel electrodes are formed via the substrate. An exposure step of exposing the resist film, and a development step of developing the exposed resist film to form partition walls separating adjacent pixel electrodes from among the plurality of pixel electrodes.

  According to the method for manufacturing an electrophoretic display device of the present invention, the pixel electrode forming step, the resist film forming step, the exposure step, and the developing step are performed in this order.

  In the pixel electrode forming step, a plurality of pixel electrodes are formed from a non-translucent material such as aluminum (Al) on a substrate such as a translucent resin substrate or a glass substrate. Typically, in the pixel electrode formation step, a plurality of pixel electrodes are arranged in a matrix.

  The resist film forming step is a resist film made of a negative resist so as to cover a plurality of pixel electrodes on the substrate (that is, a resist whose solubility in a developing solution is reduced when exposed and whose exposed portion remains after development). Form.

  In the exposure step, the resist film is exposed through the substrate from the back surface side of the substrate (that is, the surface opposite to the surface on which the plurality of pixel electrodes are formed). Here, since the plurality of pixel electrodes are formed of a non-translucent material, only a portion of the resist film that does not overlap with the pixel electrodes when viewed in plan on the substrate can be exposed.

  That is, in the exposure step, the resist film is exposed from the back side of the substrate using a plurality of non-transparent pixel electrodes as a mask. As a result, only a portion of the resist film located in a gap region (in other words, a gap) between adjacent pixel electrodes can be exposed.

  In the development step, the resist film exposed in the exposure step is developed to form a partition that separates adjacent pixel electrodes among the plurality of pixel electrodes. Here, only the portion of the resist film located in the gap region between adjacent pixel electrodes is exposed by the exposure process, so the partition is reliably formed in the gap region between adjacent pixel electrodes by the development process. can do.

  That is, according to the present invention, the resist film is exposed from the back surface side of the substrate using a plurality of pixel electrodes as a mask, and the partition wall composed of the exposed portion of the resist film (that is, the portion of the resist film irradiated with the exposure light) is formed. Since it is formed in a self-aligned manner, for example, when the substrate on which the pixel electrode is formed and the partition are bonded, the alignment between the pixel electrode and the partition is unnecessary, and the positional deviation between the pixel electrode and the partition is not necessary. Can be prevented. In addition, for example, it is possible to avoid a situation in which bubbles are generated between the substrate and the partition, which may occur when the substrate on which the pixel electrode is formed and the partition are bonded together.

  Furthermore, according to the present invention, since the resist film is exposed from the back side of the substrate, for example, the resist film is exposed from the upper side of the substrate (that is, the side opposite to the side where the resist film faces the substrate) through a photomask. Compared with the case where it does, the exposure intensity | strength of the side in which the partition contacts the board | substrate becomes strong, and can improve the adhesiveness of a partition and a board | substrate.

  As described above, according to the method for manufacturing an electrophoretic display device according to the present invention, it is possible to prevent the occurrence of displacement between the pixel electrode and the partition wall.

  In one aspect of the method for manufacturing an electrophoretic display device according to the present invention, the exposure step includes a plurality of oblique exposure steps of exposing the resist film from oblique directions that are oblique to the normal direction of the back surface. The oblique directions in each of the plurality of oblique exposure steps are different from each other.

  According to this aspect, for example, the exposure light to the resist film is blocked by wiring such as scanning lines and signal lines (or also called “data lines”) formed on the substrate, thereby reducing gaps in the partition walls. Or it can be prevented.

  In another aspect of the method for manufacturing an electrophoretic display device according to the present invention, in the exposure step, the resist film is exposed such that the wall thickness of the partition wall increases as the distance from the portion in contact with the substrate increases. To do.

  According to this aspect, for example, compared with the case where exposure is performed only along the normal direction of the back surface of the substrate, the upper surface of the partition wall (that is, the surface of the partition opposite to the side in contact with the substrate, in other words, the partition wall The area of the surface on the side opposite to the side facing the substrate can be increased. Therefore, for example, when the upper surface side of the partition wall is sealed with a sealing film, the area where the partition wall and the sealing film are in close contact with each other can be increased, and the adhesion between the partition wall and the sealing film can be improved. . Therefore, for example, it is possible to reduce or prevent the sealing film from being peeled off from the partition wall.

  In another aspect of the method for manufacturing an electrophoretic display device according to the present invention, the partition wall has a reverse-tapered cross section in which the wall thickness increases as the distance from the portion in contact with the substrate increases.

  According to this aspect, for example, when the upper surface side of the partition wall (that is, the side opposite to the side in contact with the substrate of the partition wall) is sealed with the sealing film, the area where the partition wall and the sealing film are in close contact with each other is increased. It is possible to improve the adhesion between the partition wall and the sealing film. Therefore, for example, it is possible to reduce or prevent the sealing film from being peeled off from the partition wall.

  In another aspect of the method for manufacturing an electrophoretic display device according to the present invention, the peripheral edge of each of the plurality of pixel electrodes has a zigzag shape.

  According to this aspect, the partition walls can be formed so as to have a zigzag shape along the periphery of the pixel electrode when viewed in plan on the substrate. Therefore, for example, the strength against the force of pushing the partition along the normal direction of the front surface (or the back surface) of the substrate and the strength of the partition such as the adhesion between the partition and the substrate or the sealing film can be improved.

  In another aspect of the method for manufacturing an electrophoretic display device according to the present invention, the pixel electrode forming step includes a plurality of first gap regions extending along the first direction on the substrate and the plurality of pixel electrodes, Including a wiring formation step of arranging a plurality of second gap regions extending along a second direction intersecting with the first direction in a matrix form, and forming a wiring along the first direction on the substrate; The wiring forming step includes a first intersecting portion where the wiring intersects one second gap area of the plurality of second gap areas, and the wiring includes the first second of the plurality of second gap areas. The wiring is formed such that a second intersection portion intersecting with another second gap region adjacent to the gap region is displaced from each other along the second direction, and the partition includes the first intersection portion. Corresponding gap and gap corresponding to the second intersection There are formed so as to shift from each other in the second direction.

  According to this aspect, in the pixel electrode forming step, the plurality of pixel electrodes are arranged in a matrix with the plurality of first gap regions and the plurality of second gap regions being separated, and in the developing step, the partition walls For example, a lattice shape is formed along the first gap region and the plurality of second gap regions. Further, in the exposure process, exposure light is blocked by first and second intersecting portions of wiring (eg, scanning lines, signal lines, etc.) typically formed of a non-translucent material. For this reason, a gap corresponding to the first intersecting portion and a gap corresponding to the second intersecting portion are generated in the partition formed by the developing process. Here, since the wiring is formed so that the first and second intersecting portions are shifted from each other along the second direction, the gap corresponding to the first intersecting portion generated in the partition and the second intersecting portion are formed. Are spaced from each other along the second direction. Therefore, for example, the gap corresponding to the first intersecting portion and the gap corresponding to the second intersecting portion generated in the partition wall are not shifted from each other along the second direction, but compared with a case where they are aligned linearly along the first direction. Thus, it is possible to reduce the migration of the electrophoretic particles through the gaps between the plurality of pixels on the substrate.

  In another aspect of the method for manufacturing an electrophoretic display device according to the present invention, the pixel electrode forming step includes a plurality of first gap regions extending along the first direction on the substrate and the plurality of pixel electrodes, A signal line forming step of arranging signal lines on the substrate along the first direction by arranging a plurality of second gap regions extending along a second direction intersecting the first direction with a plurality of second gap regions spaced apart from each other; A scanning line forming step of forming a scanning line on the substrate along the second direction, and a portion of the signal line that intersects the plurality of second gap regions and the plurality of the scanning lines. At least one of the portions intersecting with the first gap region is formed from a light transmissive material.

  According to this aspect, it is possible to reduce or prevent the exposure light to the resist film from being blocked by the scanning line or the signal line formed on the substrate and causing a gap in the partition wall.

  In another aspect of the method for manufacturing an electrophoretic display device according to the present invention, the method includes a step of forming a wiring on the substrate before the exposure step, and the partition wall is irradiated with the resist film in the exposure step. A gap is formed by the exposure light being blocked by the wiring.

  According to this aspect, since the gap is formed in the partition wall, for example, it is possible to easily fill the space surrounded by the partition wall with the electrophoretic dispersion liquid through the gap or to reduce bubbles. You can make a profit.

  In order to solve the above problems, the electrophoretic display device of the present invention is manufactured by the above-described method for manufacturing an electrophoretic display device according to the present invention (including various aspects thereof).

  Since the electrophoretic display device of the present invention is manufactured by the above-described method for manufacturing an electrophoretic display device according to the present invention, there is no displacement between the pixel electrode and the partition wall, and high-quality display can be performed. .

  In order to solve the above-described problems, an electronic apparatus according to the present invention includes the electrophoretic display device according to the present invention described above (including various aspects thereof).

  Since the electronic device of the present invention includes the electrophoretic display device of the present invention described above, high-quality display can be performed, such as a wristwatch, electronic paper, an electronic notebook, a mobile phone, and a portable audio device. Various electronic devices can be realized.

  The effect | action and other gain of this invention are clarified from the form for implementing invention demonstrated below.

1 is a block diagram illustrating an overall configuration of an electrophoretic display device according to a first embodiment. FIG. 3 is an equivalent circuit diagram illustrating an electrical configuration of a pixel of the electrophoretic display device according to the first embodiment. 3 is a plan view of a plurality of adjacent pixels of the electrophoretic display device according to the first embodiment. FIG. FIG. 4 is a cross-sectional view taken along line A-A ′ of FIG. 3. It is sectional drawing which shows the pixel electrode process which concerns on 1st Embodiment. It is sectional drawing which shows the resist film formation process which concerns on 1st Embodiment. It is sectional drawing which shows the exposure process which concerns on 1st Embodiment. It is sectional drawing which shows the image development process which concerns on 1st Embodiment. It is a top view which shows the planar shape of the partition which concerns on 1st Embodiment. It is a top view which shows the planar shape of the several pixel electrode and partition of the electrophoretic display device which concerns on 2nd Embodiment. It is a top view of a plurality of adjacent pixels of an electrophoretic display device concerning a 3rd embodiment. It is sectional drawing which shows the exposure process which concerns on 4th Embodiment. It is sectional drawing which shows the exposure process which concerns on 5th Embodiment. It is sectional drawing which shows the image development process which concerns on 5th Embodiment. It is sectional drawing which shows the process of providing an electrophoretic dispersion liquid and a sealing film after the image development process in 5th Embodiment. It is a perspective view which shows the structure of the electronic paper which is an example of the electronic device to which the electrophoretic display apparatus is applied. It is a perspective view which shows the structure of the electronic notebook which is an example of the electronic device to which the electrophoretic display apparatus is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
The electrophoretic display device and the manufacturing method thereof according to the first embodiment will be described with reference to FIGS.

  First, the overall configuration of the electrophoretic display device according to the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a block diagram showing the overall configuration of the electrophoretic display device according to this embodiment.

  In FIG. 1, the electrophoretic display device 1 according to the present embodiment includes a display unit 3, a controller 10, a scanning line driving circuit 60, a data line driving circuit 70, and a common potential supply circuit 220.

  In the display unit 3, m rows × n columns of pixels 20 are arranged in a matrix (in a two-dimensional plane). The display unit 3 includes m scanning lines 40 (that is, scanning lines Y1, Y2,..., Ym) and n data lines 50 (that is, data lines X1, X2,..., Xn). It is provided so as to cross each other. Specifically, the m scanning lines 40 extend in the row direction (that is, the X direction), and the n data lines 50 extend in the column direction (that is, the Y direction). Pixels 20 are arranged corresponding to the intersections of the m scanning lines 40 and the n data lines 50. The data line 50 is an example of the “signal line” according to the present invention.

  The controller 10 controls operations of the scanning line driving circuit 60, the data line driving circuit 70, and the common potential supply circuit 220. For example, the controller 10 supplies timing signals such as a clock signal and a start pulse to each circuit.

  Based on the timing signal supplied from the controller 10, the scanning line driving circuit 60 sequentially supplies a scanning signal in a pulse manner to each of the scanning lines Y1, Y2,.

  The data line driving circuit 70 supplies image signals to the data lines X1, X2,..., Xn based on the timing signal supplied from the controller 10. The image signal takes a binary potential of a high potential VH (for example, 15 V) or a low potential VL (for example, 0 V).

  The common potential supply circuit 220 supplies the common potential Vcom to the common potential line 93. Note that the common potential Vcom may be a constant potential, or may vary depending on, for example, the gradation to be written.

  Various signals are input / output to / from the controller 10, the scanning line driving circuit 60, the data line driving circuit 70, and the common potential supply circuit 220. However, those not particularly related to the present embodiment are not described here. .

  FIG. 2 is an equivalent circuit diagram illustrating the electrical configuration of the pixel.

  In FIG. 2, the pixel 20 includes a transistor 24, a pixel electrode 21, a common electrode 22, an electrophoretic dispersion liquid 23, and a storage capacitor 27.

  The transistor 24 is composed of, for example, an N-type transistor. The transistor 24 has a gate electrically connected to the scanning line 40, a source electrically connected to the data line 50, and a drain electrically connected to the pixel electrode 21 and the storage capacitor 27. ing. The transistor 24 is supplied with an image signal supplied from the data line driving circuit 70 (see FIG. 1) via the data line 50 in a pulse manner from the scanning line driving circuit 60 (see FIG. 1) via the scanning line 40. Is output at a timing corresponding to the scanning signal.

  An image signal is supplied to the pixel electrode 21 from the data line driving circuit 70 via the data line 50 and the transistor 24. The pixel electrode 21 is disposed so as to face the common electrode 22 with the electrophoretic dispersion liquid 23 interposed therebetween.

  The common electrode 22 is electrically connected to a common potential line 93 to which a common potential Vcom is supplied.

  The electrophoretic dispersion liquid 23 is a dispersion liquid in which a plurality of electrophoretic particles are dispersed in a dispersion medium. The storage capacitor 27 is composed of a pair of electrodes arranged opposite to each other with a dielectric film interposed therebetween, and one electrode is electrically connected to the transistor 24 and the pixel electrode 21, and the other electrode is electrically connected to the common potential line 93. It is connected to the. According to the storage capacitor 27, the image signal can be maintained for a certain period.

  Next, a specific configuration of the pixel of the electrophoretic display device according to the present embodiment will be described with reference to FIGS.

  FIG. 3 is a plan view of a plurality of adjacent pixels of the electrophoretic display device according to this embodiment. 4 is a cross-sectional view taken along line A-A ′ of FIG. 3. In FIGS. 3 and 4, the scale of each layer / member is different for each layer / member so that each layer / member can be recognized on the drawing. 3 and 4 show only members that are directly related to the present invention for convenience of explanation. In FIG. 3, for convenience of explanation, the illustration of the partition wall 88 shown in FIG. 4 is omitted.

  In FIG. 4, an electrophoretic dispersion liquid 23 is sandwiched between the pixel electrode 21 formed on the circuit substrate 28 and the common electrode 22 formed on the counter substrate 29.

  The circuit board 28 has a flat board 28a. On the substrate 28a, the transistor 24, the scanning line 40, the data line 50, the common potential line 93, and the storage capacitor 27 described above with reference to FIGS. 1 and 2 are formed.

  The substrate 28a is, for example, a substrate (that is, a resin substrate) made of an insulating resin material such as polycarbonate (PC) or polyethylene terephthalate (PET), or a glass substrate.

  The pixel electrode 21 is made of a non-translucent conductive material such as Al.

  The counter substrate 29 is, for example, a substrate made of an insulating resin material such as polycarbonate or polyethylene terephthalate (that is, a resin substrate), a glass substrate, or the like, similarly to the substrate 28a.

  The counter electrode 22 is made of a light-transmitting conductive material such as indium tin oxide (ITO).

  The electrophoretic dispersion liquid 23 is a dispersion liquid in which a plurality of electrophoretic particles 81 are dispersed in a dispersion medium 82.

  The electrophoretic particles 81 are, for example, pigment particles, resin particles, or composite particles thereof. Examples of the pigment constituting the pigment particles include black pigments such as aniline black and carbon black, and white pigments such as titanium oxide and antimony oxide. Examples of the resin material constituting the resin particles include acrylic resin, urethane resin, urea resin, epoxy resin, polystyrene, polyester, and the like. Examples of composite particles include those in which the surface of pigment particles is coated with a resin material or rice field pigment, in which the surface of resin particles is coated with a pigment, or a mixture of pigment and resin material mixed in an appropriate composition ratio. There are particles and so on. The electrophoretic particles 81 made of these various materials are dispersed in the dispersion medium 82 in a positively or negatively charged state, for example.

  The dispersion medium 82 is a lipophilic hydrocarbon solvent, and includes, for example, Isopar (registered trademark). That is, the dispersion medium 82 is a liquid containing any one of Isopar E, Isopar G, Isopar H, and Isopar L, a liquid in which two or more of these are mixed, or any one of these. It is a liquid in which more than one kind and other kinds of hydrocarbon solvents are mixed.

  A partition wall 88 that separates adjacent pixel electrodes 21 is formed between the circuit substrate 28 and the counter substrate 29. A sealing film 90 is provided between the common electrode 22 and the partition wall 88. The sealing film 90 is a film for enclosing the electrophoretic dispersion liquid 23 in a space surrounded by the partition walls 88 on the circuit board 28. The sealing film 90 is a film containing a water-soluble polymer, for example, a film containing polyvinyl alcohol (PVA). The water-soluble polymer contained in the sealing film 90 may be a water-soluble polymer other than polyvinyl alcohol. For example, amino acids, gum arabic, gum arabic, alginic acid derivatives, albumin, carboxymethyl cellulose, cellulose derivatives, gelatin, poly Ethylene oxide, polystyrene sulfonic acid, polyvinyl pyrrolidone, polyvinyl phenol, polyvinyl acetate derivatives and lecithin may be used.

  In FIG. 3, the scanning line 40 extends in the X direction, and the data line 50 extends in the Y direction intersecting the extending direction of the scanning line 40. A pixel electrode 21 is arranged corresponding to the intersection of the scanning line 40 and the data line 50. A plurality of pixel electrodes 21 are provided in a matrix on a circuit board 28 (see FIG. 4). That is, the plurality of pixel electrodes 21 are arranged in a matrix with a plurality of gap regions R1 extending along the X direction and a plurality of gap regions R2 extending along the Y direction, respectively. The partition walls 88 described above with reference to FIG. 4 are formed in the plurality of gap regions R1 and the plurality of gap regions R2, and are substantially latticed when viewed from the normal direction of the circuit board 28 (that is, the Z direction in FIG. 4). It has a planar shape.

  3 and 4, one transistor 24 and one storage capacitor 27 are provided corresponding to each of the plurality of pixel electrodes 21.

  The transistor 24 includes a semiconductor layer 24a. The source region of the semiconductor layer 24 a is electrically connected to the data line 50, and the drain region of the semiconductor layer 24 a is electrically connected to the pixel electrode 21 via the upper electrode 27 a of the storage capacitor 27. The gate electrode of the transistor 24 is formed as a part of the scanning line 40. When the scanning signal is supplied from the scanning line 40, the transistor 24 is turned on for a certain period (that is, the source region and the drain region of the semiconductor layer 24a are electrically connected). Thereby, the image signal supplied from the data line 50 is written to the pixel 20 at a predetermined timing (that is, a voltage corresponding to the image signal is applied between the pixel electrode 21 and the common electrode 22).

  The storage capacitor 27 includes an upper electrode 27a, a lower electrode 27b, and an insulating film 111.

  The upper electrode 27 a is electrically connected to the drain region of the semiconductor layer 24 a and is also electrically connected to the pixel electrode 21 through a contact hole 121 formed in the insulating film 112.

  The lower electrode 27b is provided on the substrate 28a so as to face the upper electrode 27a through the insulating film 111, and is electrically connected to a common potential line 93 extending in the X direction.

  Next, a manufacturing method of the electrophoretic display device 1 configured as described above will be described with reference to FIGS. In the following description, processes related to the formation of the partition wall 88 (for example, a pixel electrode formation process, a resist film formation process, an exposure process, and a development process) that are characteristic of the present embodiment in the manufacturing process of the electrophoretic display device 1 will be described. Mainly explained.

  FIG. 5 is a cross-sectional view showing a pixel electrode process according to this embodiment. FIG. 6 is a cross-sectional view showing a resist film forming process according to this embodiment. FIG. 7 is a cross-sectional view showing an exposure process according to the present embodiment. FIG. 8 is a cross-sectional view showing a developing process according to this embodiment. 5 to 8 are shown corresponding to the cross-sectional view shown in FIG.

  First, in the pixel electrode formation step shown in FIG. 5, a plurality of pixel electrodes 21 are formed on the circuit board 28 from a non-translucent material such as Al. At this time, the plurality of pixel electrodes 21 are separated from each other by a plurality of gap regions R1 (see FIG. 3) extending along the X direction and a plurality of gap regions R2 (see FIG. 3) extending along the Y direction. Arranged in a shape. Here, from the viewpoint of reducing the area of the gap regions R1 and R2 (in other words, a portion where a partition wall 88 to be described later is formed) that is a portion that does not contribute to display (that is, a non-display portion) in the display unit 3, The width of each of the regions R1 and R2 is preferably 5 um to 20 um, for example.

  Note that various elements and wirings such as the transistor 24, the storage capacitor 27, the scanning line 40, and the data line 50 formed on the circuit board 28 are connected to the pixel electrode 21 when viewed in plan on the circuit board 28 as much as possible. It is preferable to form so that it may overlap. Accordingly, in the exposure process described later with reference to FIG. 7, the exposure light is blocked in the gap regions R <b> 1 and R <b> 2 by various elements and wirings such as the transistor 24, the storage capacitor 27, the scanning line 40, and the data line 50. Can be suppressed or prevented.

  Next, in the resist film forming step shown in FIG. 6, a resist film 500 is formed by applying a negative resist so as to cover the plurality of pixel electrodes 21 on the circuit substrate 28. At this time, the resist film 500 is formed to have a predetermined film thickness of, for example, 20 μm to 100 μm. In this embodiment, since the partition wall 88 is formed from the resist film 500, the thickness of the resist film 500 is determined according to the height of the partition wall 88 to be formed. Moreover, as a negative resist, it is possible to use a general photosensitive material. For example, polyacrylate, polyvinyl compound, polyurethane, polyester, epoxy compound, polyamide, polyimide, novolac resin, fluorene resin, etc. A resin composition comprising a radically polymerizable compound such as a binder resin, a polyfunctional acrylate and a polyfunctional methacrylate, a photopolymerization initiator, and the like, and a mixture thereof can be used.

  In the resist film forming step, a process for improving the adhesion between the circuit board 28 and the negative resist may be performed before applying the negative resist on the circuit board 28. As such a treatment, for example, a surface treatment using a surface modifier such as hexamethyldisilazane, cyclohexane, octadecyltrichlorosilane or a self-assembled monolayer, an organic cleaning treatment using acetone, propyl alcohol, or the like, Acids such as hydrochloric acid, sulfuric acid, acetic acid, alkali treatment such as sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, UV ozone treatment, fluorination treatment, plasma treatment such as oxygen or argon, Langmuir Blodgett film formation treatment May be performed, or an adhesive layer for improving adhesion may be formed, or one or two or more of these treatments may be used.

  In the resist film forming step, the resist film 500 may be formed by attaching a film resist made of a negative resist on the circuit board 28 so as to cover the plurality of pixel electrodes 21.

  Next, in the exposure step shown in FIG. 7, the resist film 500 is exposed through the circuit substrate 28 from the back surface S2 side opposite to the front surface S1 on which the plurality of pixel electrodes 21 of the circuit substrate 28 are formed. At this time, the exposure light is blocked by the pixel electrode 21 formed of a non-translucent material. Therefore, the exposure light is not irradiated on the portion of the resist film 500 that overlaps the pixel electrode 21 when viewed in plan on the circuit substrate 28, but is irradiated on the portion of the resist film 500 that is located in the gap regions R1 and R2. The

  That is, in the exposure step, the resist film 500 is exposed from the back surface S2 side of the circuit board 28 using the nontranslucent pixel electrodes 21 as a mask. As a result, only the portions of the resist film 500 located in the gap regions R1 and R2 between the adjacent pixel electrodes 21 can be exposed.

  Next, in the development step shown in FIG. 8, the resist film 500 exposed in the exposure step is developed to form the partition wall 88 that separates the pixel electrodes 21 adjacent to each other among the plurality of pixel electrodes 21. Here, as described above, only the portions of the resist film 500 located in the gap regions R1 and R2 between the adjacent pixel electrodes 21 are exposed by the exposure process. It can be reliably formed in the gap regions R1 and R2 between the adjacent pixel electrodes 21.

  As described above, according to the present embodiment, the resist film 500 is exposed from the back surface S2 side of the circuit substrate 28 using the plurality of pixel electrodes 21 as a mask, and the exposed portion of the resist film 500 (the gap region R1 and Since the partition wall 88 formed of the portion located at R2 is formed in a self-aligned manner, for example, the pixel electrode 21 is necessary when the circuit substrate 28 on which the pixel electrode 21 is formed and the separately formed partition wall 88 are bonded together. And alignment of the partition wall 88 is not necessary, and the occurrence of misalignment between the pixel electrode 21 and the partition wall 88 can be prevented. In addition, for example, it is possible to avoid a situation where bubbles are generated between the circuit board 28 and the partition wall 88, which may occur when the circuit substrate 28 on which the pixel electrode 21 is formed and the partition wall 88 are bonded together.

  Furthermore, according to the present embodiment, since the resist film 500 is exposed from the back surface S2 side of the circuit board 28, for example, the upper side of the circuit board 28 (that is, the side opposite to the side where the resist film 500 faces the circuit board 28). Compared with the case where the resist film 500 is exposed through a photomask, the adhesion between the partition wall 88 and the circuit board 28 can be improved.

  FIG. 9 is a plan view showing a planar shape of the partition wall 88.

  As shown in FIG. 9, according to the present embodiment, as described above, the partition wall 88 can be reliably formed in the gap regions R1 and R2 between the pixel electrodes 21 adjacent to each other. Here, in this embodiment, since the data line 50, the scanning line 40, and the common potential line 93 are formed of a non-translucent material, the data line 50 is formed in the partition 88 at a portion where it intersects the gap region R1. A corresponding gap 121, a gap 122 corresponding to a portion where the scanning line 40 intersects the gap region R2, and a gap 123 corresponding to a portion where the common potential line 93 intersects the gap region R2 are formed. By forming such gaps 121, 122, and 123, it is possible to easily fill the electrophoretic dispersion liquid 23 or reduce bubbles in all the pixels 20 of the display unit 3 through the gaps 121, 122, and 123. You can get practical benefits such as.

  As described above, according to the present embodiment, it is possible to prevent the positional deviation between the pixel electrode 21 and the partition wall 88. Further, the adhesion between the partition wall 88 and the circuit board 28 can be improved.

<Modification>
As a modification of the first embodiment described above, the scanning lines 40, the data lines 50, and the common potential lines 93 may be formed of a light-transmitting material such as ITO. In this case, in the exposure process, the exposure light for the resist film 500 is blocked by the scanning lines 40, the data lines 50, and the common potential lines 93 formed on the circuit board 28, and a gap (for example, see FIG. 9) is formed in the partition wall 88. Thus, the occurrence of the gaps 121, 122, and 123) described above can be reduced or prevented. The partition wall 88 can also be formed by forming a part of the scanning line 40, the data line 50, and the common potential line 93 including a portion intersecting at least one of the gap regions R1 and R2 from a light-transmitting material. The effect of reducing the occurrence of gaps can be obtained accordingly.

<Second Embodiment>
A method of manufacturing the electrophoretic display device according to the second embodiment will be described with reference to FIG.

  The manufacturing method of the electrophoretic display device according to the second embodiment is the electrophoresis according to the first embodiment described above in that each of the plurality of pixel electrodes 21 is formed to have a zigzag periphery in the pixel electrode forming step. Unlike the method for manufacturing the display device, the other points are substantially the same as the method for manufacturing the electrophoretic display device according to the first embodiment described above.

  FIG. 10 is a plan view showing a planar shape of the plurality of pixel electrodes 21 and the partition walls 88 of the electrophoretic display device according to the second embodiment.

  As shown in FIG. 10, in this embodiment, in particular, in the pixel electrode formation step, each of the plurality of pixel electrodes 21 is formed to have a zigzag-shaped periphery. That is, the periphery of each of the plurality of pixel electrodes 21 has a zigzag shape. Therefore, by performing the resist film formation process, the exposure process, and the development process similar to those of the first embodiment described above, the zigzag shape along the periphery of the pixel electrode 21 is obtained in plan view on the circuit board 28. A partition wall 88 can be formed. Therefore, the strength of the partition 88 can be improved along the normal direction of the circuit board 28 (that is, the Z direction in FIG. 4), for example, the strength against the pressing force of the partition 88 from the counter substrate 29 side.

<Third Embodiment>
A method of manufacturing the electrophoretic display device according to the third embodiment will be described with reference to FIG.

  FIG. 11 is a plan view of a plurality of adjacent pixels of the electrophoretic display device according to the third embodiment.

  In FIG. 11, the manufacturing method of the electrophoretic display device according to the third embodiment is such that the data line 50 intersects one gap region R1a among the plurality of gap regions R1, and the data line 50 has a plurality of gaps. The first embodiment described above in that the data line 50 is formed so that the intersecting portion 52 intersecting with the other gap region R1b adjacent to the one gap region R1a in the region R1 is displaced from each other along the X direction. Unlike the method for manufacturing the electrophoretic display device according to the embodiment, the other points are substantially the same as the method for manufacturing the electrophoretic display device according to the first embodiment described above.

  In the present embodiment, in particular, the intersection 51 where the data line 50 intersects one gap area R1a among the plurality of gap areas R1, and the data line 50 adjacent to one gap area R1a among the plurality of gap areas R1. The data line 50 is formed so that the intersecting portion 52 intersecting with the gap region R1b is shifted from each other along the X direction. Therefore, the gap 121a corresponding to the intersecting portion 51 generated in the partition wall 88 and the gap 121b corresponding to the intersecting portion 52 are shifted from each other along the X direction. Accordingly, for example, when the plurality of gaps 121 generated in the partition wall 88 are not shifted from each other along the X direction and are linearly arranged along the Y direction (for example, in the first embodiment described above with reference to FIG. 9). Compared with the electrophoretic display device 1), it is possible to reduce the movement of the electrophoretic particles 81 through the gaps 121 of the partition walls 88 between the plurality of pixels 20 on the circuit board 28.

<Fourth embodiment>
A manufacturing method of the electrophoretic display device according to the fourth embodiment will be described with reference to FIG.

  FIG. 12 is a cross-sectional view showing an exposure process according to the fourth embodiment. FIG. 12A shows a step of exposing from the first oblique direction, and FIG. 12B shows a step of exposing from the second oblique direction.

  In FIG. 12, in the manufacturing method of the electrophoretic display device according to the fourth embodiment, the first oblique direction (in which the exposure step is oblique with respect to the normal direction (ie, the Z direction) of the back surface S2 of the circuit board 28 ( That is, the exposure process from the direction indicated by the block arrow P1 in FIG. 12 (hereinafter referred to as “oblique direction P1” as appropriate) and the normal direction of the back surface S2 of the circuit board 28 are oblique and the oblique direction P1. The electrophoretic display according to the first embodiment described above includes the step of exposing from a second oblique direction (ie, the direction indicated by the block arrow P2 in FIG. 12; hereinafter referred to as “oblique direction P2” as appropriate). Unlike the method for manufacturing the device, the other points are substantially the same as the method for manufacturing the electrophoretic display device according to the first embodiment described above.

  In the present embodiment, in particular, in the exposure step, the resist film 500 is exposed from the oblique direction P1 (see FIG. 12A) and the resist film 500 is exposed from the oblique direction P2 (see FIG. 12B). Therefore, it is possible to prevent the exposure light to the resist film 500 from being blocked by the data line 50 formed of the non-translucent material on the circuit board 28 and causing a gap in the partition wall 88. Therefore, the electrophoretic dispersion liquid 23 can be prevented from moving between the plurality of pixels 20 through the gaps of the partition walls 88. Thereby, for example, an electrophoretic dispersion liquid including red electrophoretic particles, an electrophoretic dispersion liquid including green electrophoretic particles, and an electrophoretic dispersion liquid including blue electrophoretic particles are provided in different predetermined pixels 20. High-quality color display can be performed.

<Fifth Embodiment>
A method for manufacturing an electrophoretic display device according to the fifth embodiment will be described with reference to FIGS.

  The manufacturing method of the electrophoretic display device according to the fifth embodiment is that in the exposure step, the resist film 500 is exposed so that the wall thickness of the partition wall 88 increases as the distance from the surface S1 of the circuit board 28 increases. Unlike the method for manufacturing the electrophoretic display device according to the first embodiment described above, the other points are substantially the same as the method for manufacturing the electrophoretic display device according to the first embodiment described above.

  FIG. 13 is a cross-sectional view showing an exposure process according to the fifth embodiment, and FIG. 14 is a cross-sectional view showing a development process according to the fifth embodiment. FIG. 15 is a cross-sectional view showing a process of providing the electrophoretic dispersion liquid 23 and the sealing film 90 after the development process in the fifth embodiment.

  As shown in FIG. 13, in the present embodiment, in particular, in the exposure process, the resist film 500 is circuitized so that the wall thickness d (see FIG. 16) of the partition wall 88 increases as the distance from the surface S1 of the circuit board 28 increases. Exposure is performed from the back surface S2 side of the substrate. That is, by exposing from the back surface S2 side of the circuit board 28, the exposure light is gradually diffused in the resist film 500 as the distance from the surface S1 of the circuit board 28 increases.

  Therefore, as shown in FIG. 14, as the distance from the surface S <b> 1 of the circuit board 28 increases (in other words, the distance from the portion in contact with the circuit board 28 increases), the wall thickness d increases as a result of the development process. 88 (that is, the partition wall 88 having a reverse tapered cross section) can be formed.

  Therefore, as shown in FIG. 15, when the electrophoretic dispersion liquid 23 is injected into the space surrounded by the partition wall 88 on the circuit substrate 28 and then the sealing film 90 is provided in close contact with the upper surface of the partition wall 88, The area where the sealing film 90 and the partition wall 88 are in close contact with each other can be increased as compared with the first embodiment described above with reference to FIG. As a result, the adhesion of the sealing film 90 to the partition wall 88 can be improved, and the peeling of the sealing film 90 from the partition wall 88 can be reduced or prevented.

<Electronic equipment>
Next, electronic devices to which the above-described electrophoretic display device is applied will be described with reference to FIGS. Below, the case where the electrophoretic display device described above is applied to electronic paper and electronic notebook is taken as an example.

  FIG. 16 is a perspective view illustrating a configuration of the electronic paper 1400.

  As illustrated in FIG. 16, the electronic paper 1400 includes the electrophoretic display device according to the above-described embodiment as a display unit 1401. The electronic paper 1400 has flexibility, and includes a main body 1402 formed of a rewritable sheet having the same texture and flexibility as conventional paper.

  FIG. 17 is a perspective view illustrating a configuration of the electronic notebook 1500.

  As shown in FIG. 17, an electronic notebook 1500 is one in which a plurality of electronic papers 1400 shown in FIG. 16 are bundled and sandwiched between covers 1501. The cover 1501 includes display data input means (not shown) for inputting display data sent from an external device, for example. Thereby, according to the display data, the display content can be changed or updated while the electronic paper is bundled.

  Since the electronic paper 1400 and the electronic notebook 1500 described above include the electrophoretic display device according to the above-described embodiment, high-quality image display can be performed.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and an electrophoretic display with such a change. A device manufacturing method, an electrophoretic display device, and an electronic apparatus including the electrophoretic display device are also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 21 ... Pixel electrode, 22 ... Common electrode, 23 ... Electrophoretic dispersion liquid, 24 ... Transistor, 27 ... Retention capacity, 28 ... Circuit board, 29 ... Opposite substrate, 40 ... Scan line, 50 ... Data line, 81 ... Electrophoresis Particles, 82 ... dispersion, 88 ... partition, 90 ... sealing film, 93 ... common potential line, 121, 122, 123 ... gap, 500 ... resist film, R1, R2 ... gap region, S1 ... surface, S2 ... back surface

Claims (9)

Forming a wiring on the light-transmitting substrate along the first direction on the substrate; and
Forming a plurality of pixel electrodes on the substrate from a non-translucent material; and
Forming a resist film made of a negative resist so as to cover the plurality of pixel electrodes on the substrate;
An exposure step of exposing the resist film through the substrate from the back side opposite to the surface on which the plurality of pixel electrodes of the substrate are formed;
By developing the exposed resist film, seen including a developing step of forming a partition wall separating between pixel electrodes adjacent to each other among the plurality of pixel electrodes,
A method for manufacturing an electrophoretic display device, wherein a gap is formed in the partition wall by blocking exposure light applied to the resist film in the exposure step by the wiring . The exposure step includes
A plurality of oblique exposure steps for exposing each of the resist films from oblique directions that are oblique to the normal direction of the back surface;
The method for manufacturing an electrophoretic display device according to claim 1, wherein the oblique directions in each of the plurality of oblique exposure steps are different from each other.   2. The electrophoretic display device according to claim 1, wherein in the exposing step, the resist film is exposed such that a wall thickness of the partition wall increases as a distance from a portion in contact with the substrate increases. Production method.   2. The method of manufacturing an electrophoretic display device according to claim 1, wherein the partition wall has a reverse-tapered cross section in which the wall thickness increases as the distance from the portion in contact with the substrate increases.   5. The method of manufacturing an electrophoretic display device according to claim 1, wherein the periphery of each of the plurality of pixel electrodes has a zigzag shape. 6. The pixel electrode forming step includes a plurality of first gap regions extending along a first direction on the substrate and a plurality of first gap regions extending along a second direction intersecting the first direction. 2 arranged in a matrix with a gap area,
The wiring forming step includes a first intersecting portion where the wiring intersects one second gap area of the plurality of second gap areas, and the wiring includes the first second of the plurality of second gap areas. Forming the wiring so that a second intersecting portion intersecting with another second gap region adjacent to the gap region is displaced from each other along the second direction;
The clearance gap corresponding to the said 1st cross | intersection part and the clearance gap corresponding to the said 2nd cross | intersection part are formed in the said partition so that it may mutually shift | deviate along the said 2nd direction. To 5. The method for producing an electrophoretic display device according to any one of claims 1 to 5. The pixel electrode forming step includes a plurality of first gap regions extending along a first direction on the substrate and a plurality of first gap regions extending along a second direction intersecting the first direction. 2 arranged in a matrix with a gap area,
The wiring forming step includes a signal line forming step for forming a signal line along the first direction on the substrate, and a scanning line forming step for forming a scanning line along the second direction on the substrate. Including
At least one of a portion of the signal line that intersects with the plurality of second gap regions and a portion of the scanning line that intersects with the plurality of first gap regions are formed of a translucent material. A method for manufacturing an electrophoretic display device according to any one of claims 1 to 5. The electrophoretic display device, characterized in that it is manufactured by the manufacturing method of the electrophoretic display device according to any one of claims 1 to 7. An electronic apparatus comprising the electrophoretic display device according to claim 8 .

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