JP4934277B2 - Pixel structure of display device using fiber substrate and manufacturing method thereof - Google Patents

Description

The present invention relates to a pixel structure of a display device using a fiber substrate and a manufacturing method thereof, and more particularly to an element such as an electronic device and a light emitting element formed using a fiber on a substrate and a manufacturing method thereof.

  The current mainstream active matrix flat panel display device is a flat panel display composed of a pixel drive switch composed of TFT (Thin Film Transistor) and a pixel display medium on the display surface, and the starting substrate is a transparent glass plate such as soda lime. . Attempts have been made to use a plastic film as the substrate, but it has not yet been put to practical use, liquid crystal as the display medium, and a-Si TFT (Amorphous-Silicon-TFT) as the active matrix are currently mainstream, 10 "to 20" diagonal displays are mass-produced for PCs, monitors and the like.

  LCD (Liquid Crystal Display) as a display medium has problems in display performance of television moving images, particularly white, white peak, and responsiveness, compared with CRT (Cathode Ray Tube). In contrast, organic LEDs (Organic Light-Emitting-Diodes) (OLEDs) that have recently been developed and commercialized are self-luminous and can achieve better image quality than LCDs, such as white and white peak responsiveness. .

  On the other hand, the development and commercialization of polycrystalline Si (p-Si), which is a low-temperature process, has been rapidly advanced recently. This is because p-Si TFT performance is high and peripheral circuits can be built in, which has the advantage of cost reduction. In addition to this, it is difficult to drive an OLED with an a-Si TFT in terms of drive current density, and the TFT tends to shift to low-temperature p-Si as a whole, including application to LCD.

  The market requirements for all display devices including active matrix flat display devices are always three points: increase in display size, higher definition, and lower cost. In response to these requirements, the current mainstream a-Si TFT-LCD has little room for performance improvement, with a 40 "diagonal television for large size and a display of 20" or less for high definition. In terms of cost, the only way to deal with costs is to increase the size of the glass substrate. Further, the glass substrate is required to have high precision flatness, and it is difficult to use a substrate having a curved surface.

  On the other hand, Patent Document 1 below describes that a display device is configured by arranging fibers formed with OLED elements on a substrate. According to this, it is possible to form the display device by arranging the fibers along the curved surface of the substrate.

The OLED element is formed along one side of a fiber having a quadrangular cross section, a transparent electrode formed in the longitudinal direction of the fiber, an OLED layer formed thereon, and further spaced along the longitudinal direction on the OLED layer. And a plurality of upper electrodes formed at a distance from each other.
Japanese translation of PCT publication No. 2002-538502

  However, according to the element having such a structure, the transparent electrode or OLED protruding on the fiber is formed when the fiber is wound, cut, or placed on the substrate after the OLED element is formed on the fiber. Since the layer and the upper electrode are liable to be damaged by coming into contact with a jig or the like, it causes a decrease in yield.

An object of the present invention is to provide a pixel structure of a display device using a fiber substrate having a structure that is not easily damaged from the outside, and a manufacturing method thereof.

A pixel structure of a display device using a fiber substrate according to the first aspect of the present invention is formed on a light emitting element formed on an outer peripheral surface of a fiber, and on the fiber and beside the light emitting element. a protective insulating film that, the, in a region where the light emitting element is formed, the insulation layer and the bottom of the light emitting element is characterized in that recess is formed to the wall surface.

According to a second aspect of the present invention, in the first aspect, the light-emitting element includes a transparent electrode formed on the outer peripheral surface of the fiber, a light-emitting layer formed on the transparent electrode, and the light-emitting element. And an upper electrode formed on the layer.

According to a third aspect of the present invention, in any one of the first and second aspects, the upper surface of the light emitting element is formed at a position lower than the upper surface of the protective insulating film with respect to the surface of the fiber. It is characterized by that.

According to a fourth aspect of the present invention, there is provided a pixel structure manufacturing method for a display device using a fiber substrate, the step of forming a protective insulating film having an opening on the outer peripheral surface of the fiber, and light emission in the opening and a step of forming an element, in a region where the light emitting element is formed, the insulation layer and the bottom of the light emitting element is characterized in that recess is formed to the wall surface.

According to a fifth aspect of the present invention, in the fourth aspect, after forming a transparent conductive film to be the light emitting element on the fiber, the protective insulating film is formed on the fiber, and from the opening, The method includes a step of exposing the transparent conductive film, and a step of sequentially forming a light emitting layer to be the light emitting element and an upper electrode on the transparent conductive film exposed from the opening .

According to the present invention, since the protective insulating film is formed in the pixel structure of the display device using the fiber substrate other than the region where the element is formed, the protrusion of the element is reduced or the element is placed above the protective insulating film. It can be made not to protrude. In addition, according to the present invention, since the concave portion is formed in the fiber substrate and the element is formed in the concave portion, it is possible to prevent the element from protruding from the fiber or to reduce the protruding amount of the element from the fiber. it can. Therefore, the element formed on the fiber is prevented from being damaged due to contact with the jig or the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 are cross-sectional views showing a manufacturing process of a display device using a fiber according to the first embodiment of the present invention.

  First, a light-transmitting fiber 1 made of quartz or the like having a substantially rectangular shape as shown in FIG. 1A wound around a reel (not shown) is prepared and used as a substrate for forming an element. The cross section has a size of about 0.3 mm × 0.3 mm, for example.

  In addition, as a light transmissive fiber, in addition to quartz, glass fiber such as borosilicate or soda lime glass, sapphire, and other suitable glass materials, or methyl methacrylate (PMMA), polycarbonate, acrylic, mylar Plastic fibers made of polyester, polyimide, other suitable plastic materials, or the like may be used.

Next, the fiber 1 is pulled out from the reel and guided into a film forming apparatus (not shown). As shown in FIG. 1B, the first, second and third surfaces 1a, 1b, A transparent electrode 2 is formed to a thickness of about 100 nm by sequentially depositing indium tin oxide (ITO), zinc oxide (ZnO), and tin oxide (SnO ₂ ) on 1c by sputtering. The transparent conductive material is deposited in a substantially vertical direction on each of the first to third surfaces of the fiber 1.

  Next, as shown in FIG. 1C, reflecting films 3 and 4 are formed on the transparent electrodes 2 on the first and third surfaces 1a and 1c on both sides of the second surface 1b of the fiber 1 by a sputtering method. Form to thickness. The reflective films 3 and 4 are composed of a two-layer structure conductive film in which chromium (Cr) and aluminum (Al) are sequentially formed, and a two-layer structure conductive film in which titanium (Ti) and aluminum are sequentially formed.

Further, as shown in FIG. 1D, a light-transmitting protective insulating film 5 made of silicon dioxide (SiO ₂ ) is formed on the fiber 1, the transparent electrode 2, and the reflective films 3 and 4 by a CVD (chemical vapor deposition) method. A predetermined thickness is formed thereon. Thereafter, a resist 6 is applied on the protective insulating film 5.

  Next, as shown in FIG. 1E, the resist 6 is exposed and developed and patterned to form an opening 6a in the pixel region on the second surface 1b of the fiber 1. A plurality of the openings 6a are formed at intervals along the longitudinal direction of the fiber 1, and the size of these planes is, for example, 50 μm × 50 μm or less. In addition, since the exposure light irradiated to the resist 6 is also irradiated to the resist 6 on the fourth surface 1d on the opposite side through the fiber 1, the resist on the fourth surface where the transparent electrode 2 is not formed. 6 also has an opening 6b.

  Next, as shown in FIG. 1F, the protective insulating film 5 is etched through the openings 6a and 6b of the resist 6 by dry etching using a chlorine-based gas to form the openings 5a and 5b. Thereby, a part of the transparent conductive film 2 is exposed through the opening 5a on the second surface 1b of the fiber 1, and a part of the fiber 1 is exposed through the opening 5b on the fourth surface 1d.

  Furthermore, as shown in FIG. 2A, an OLED film 7 is formed on the transparent conductive film 2 by vapor deposition through the opening 5a of the protective insulating film 5 and the opening 6a of the resist 6, and then magnesium (Mg) The upper electrode 8 having a two-layer structure formed by sequentially forming silver (Ag) or a two-layer structure formed by sequentially forming calcium (Ca) and aluminum is formed by a vapor deposition method.

  Thereafter, as shown in FIG. 2B, when the resist 6 is removed by wet or dry, the OLED film 7 and the upper electrode 8 deposited on the resist 6 are removed, so that the OLED film 7 and the upper electrode 8 are It is selectively left in the opening 5a of the protective insulating film 5. The upper electrode 8, the OLED film 7 and the transparent electrode 2 constitute a light emitting element.

  Further, after the fiber 1 is cut into a predetermined length, the upper electrode 8 is applied to the solder bump 13 on the conductive data line segment wiring 12 formed on the insulating substrate 11 as shown in FIG. Connect. Thus, pixels for one row or one column of the display device are arranged on the insulating substrate 10.

  As described above, the OLED film 7 and the upper electrode 8 constituting each pixel on the fiber 1 are formed in the opening 5a of the protective insulating film 5 and do not protrude from the upper surface of the protective insulating film 5 or are protected. Since the upper electrode 8 can be protruded by a necessary amount by adjusting the thickness of the film 5, the upper electrode 8 and the OLED film 7 are prevented from coming into contact with a jig or the like when the fiber 1 is wound or cut. It is difficult to be damaged and the yield is improved.

  Further, if the thickness of the protective insulating film 5 is adjusted so that the upper electrode 8 does not protrude from the upper surface of the protective insulating film 5, a recess is formed in the upper electrode 8 and its periphery. It becomes possible to allow a part of the fiber 1 to enter, and positioning of the fiber 1 with respect to the insulating substrate 11 becomes easy.

  By the way, since the transparent electrode 2 formed along the longitudinal direction of the fiber 1 is connected to a selection line signal wiring (not shown) at an end thereof, it is preferable to electrically reduce the resistance value. In the above structure, since the reflection films 3 and 4 are made of a conductive metal, the resistance value of the transparent conductive film 2 is substantially reduced. However, in order to further reduce the resistance, as shown in FIG. 3, the lower layer portion 2a of the transparent conductive film 2 made of a transparent conductive material is formed on the first surface 1a and the third surface 1c of the fiber 1 by vapor deposition. The transparent conductive film 2, the reflective films 3 and 4, the protective insulating film 5, the OLED film 7, and the upper electrode 8 may be formed in advance through the above-described steps.

  Note that an amorphous, polycrystalline, or single crystal silicon film may be formed on the fiber 1 and a transistor may be formed on the silicon film.

(Second Embodiment)
FIG. 4 is a perspective view showing a fiber used for forming an element according to the second embodiment of the present invention, and FIGS. 5 and 6 are steps for forming a light emitting element using the fiber according to the second embodiment of the present invention. FIG.

  First, the fiber 21 shown in FIG. 4 is used as a substrate and has a substantially square shape with a cross section of, for example, 0.3 mm × 0.3 mm, and the first surface 21a has a length direction. Concave portions 20 are formed at regular intervals and wound around a reel (not shown). The recess 20 has a planar shape of, for example, 50 μm × 50 μm or less. When the fiber 21 is made of quartz, the recess 20 is formed by a lithography method using a resist mask and etching.

Next, the fiber 21 is pulled out from the reel and guided into a film forming apparatus (not shown). As shown in FIG. 5A, the outer surface of the fiber 21 is sputtered onto the first surface 21a on which the recess 20 is formed. A transparent electrode 22 made of a three-layer transparent conductive material formed by sequentially forming ITO, ZnO, and SnO ₂ is formed to a thickness of about 100 nm. According to the sputtering, a transparent conductive material is deposited in a direction substantially perpendicular to the first surface 21a of the fiber 21, and a part of the transparent conductive material is one of the second surface 21b and the third surface 21c on both sides of the first surface 21a. It is formed around the part.

  Next, as shown in FIG. 5B, conductive reflective films 23 and 24 are formed on the second surface 21b and the third surface 21c on both sides of the first surface 21a of the fiber 21 by sputtering. The reflective films 23 and 24 are formed, for example, in a two-layer structure in which Cr and Al are formed in order, or in a two-layer structure in which Ti and Al are formed in order. In this case, since the reflection films 23 and 24 are formed so as to wrap around the first surface of the fiber 21, a part thereof is electrically connected to the transparent electrode 2.

Further, as shown in FIG. 5C, a light-transmitting protective insulating film 25 made of SiO ₂ is formed by a CVD method so as to cover the fiber 21, the transparent electrode 22, and the reflective films 23 and 24.

  Subsequently, after applying a resist 26 on the protective insulating film 25, as shown in FIG. 5D, the resist 26 is patterned by exposure and development, and the recesses 20 of the first surface 21a of the fiber 21 are formed. An opening 26a is formed on the top. The opening 26a is formed for each recess 20 along the longitudinal direction of the fiber 1 and has a planar shape of, for example, 50 μm × 50 μm or less. Since the exposure light for exposing the resist 26 passes through the fiber 21 and is also irradiated to the resist 26 on the fourth surface 21d on the opposite side, the resist 26 on the surface where the transparent electrode 22 is not formed is also irradiated. An opening 26b is formed.

  Next, as shown in FIG. 6A, the protective insulating film 25 is etched through the openings 26a and 26b of the resist 26 by dry etching using a chlorine-based gas to form the openings 25a and 25b. Thereby, a part of the transparent conductive film 22 is exposed through the opening 25 a on the first surface of the fiber 21.

  Thereafter, as shown in FIG. 6B, the OLED film 27 is formed on the transparent electrode 22 through the opening 25a of the protective insulating film 25 formed on the first surface 21a of the fiber 21 and the opening 26a of the resist 26. Then, an upper electrode 28 having a two-layer structure in which Mg and Ag are sequentially formed, or a two-layer structure in which Ca and Al are sequentially formed is evaporated on the OLED film 27.

  Thereafter, as shown in FIG. 6C, when the resist 26 is removed by wet or dry, the OLED film 27 and the upper electrode 28 on the resist 26 are also removed, so that the OLED film 27 and the upper electrode 28 are protected and insulated. It remains selectively in the opening 25a of the membrane 25. The OLED film 27 and the upper electrode 28 can be left in the opening 25 a of the protective insulating film 25 so as not to protrude from the protective insulating film 25. As a result, a light emitting element including the transparent electrode 22, the OLED film 27, and the upper electrode 28 is formed in the pixel region.

  Further, after the fiber 21 is cut to a predetermined length, the upper electrode 28 is applied to the solder bump 33 on the conductive data line segment wiring 32 formed on the insulating substrate 31 as shown in FIG. By connecting, one column or one row of pixels in the display device is formed.

  Since the light emitting element having the OLED film 27 in the present embodiment has a small protruding amount from the fiber 21 due to the recess 20 formed in the fiber 21, the thickness of the protective insulating film 25 for protecting the light emitting element is reduced. It becomes possible to make it thinner than the protective insulating film 5 of 1st Embodiment, and the film | membrane formed around the fiber 21 can be made thin, and it can contribute to thickness reduction of a display apparatus by this.

  Similarly to the first embodiment, the upper electrode 28 is prevented from protruding from the protective insulating film 25, or the upper electrode 28 is made lower than the protective insulating film 25 with respect to the fiber 21. A depression can be formed on the top.

(Third embodiment)
FIG. 7 is a cross-sectional view illustrating a manufacturing process of a pixel structure in a display device using a fiber substrate according to the third embodiment of the present invention.

  First, a light-transmitting fiber 41 made of elliptical quartz or the like having a cross section shown in FIG. The major axis diameter of the ellipse is, for example, 800 μm or less that can be wound. As the transparent fiber 41, in addition to quartz, the glass material or plastic material shown in the first embodiment may be used.

Next, the fiber 41 is pulled out from the reel and guided into a film forming apparatus (not shown). As shown in FIG. 7B, a transparent electrode 42 made of a transparent conductive material is sputtered on the outer periphery to a thickness of about 100 nm. To form. As the transparent conductive material, for example, a three-layer structure formed by sequentially forming ITO, ZnO ₂ , and SnO ₂ is formed. The sputtering is performed while rotating the fiber 41 in the circumferential direction.

  Next, as shown in FIG. 7C, reflection films 43 and 44 separated left and right around the long axis of the cross section of the fiber 41 are formed by sputtering. The reflective films 43 and 44 are deposited in the minor axis direction of an ellipse that is the cross-sectional shape of the fiber 41. As the reflection films 43 and 44, for example, a two-layer structure film is formed as in the first embodiment.

Further, as shown in FIG. 7D, transparent protective insulating films 45a and 45b made of SiO ₂ are formed on the reflective films 43 and 44 by an electron cyclotron resonance (ECR) sputtering method or the like. The protective insulating films 45 a and 45 b are deposited in the minor axis direction of an ellipse that is the cross-sectional shape of the fiber 41. When the left and right protective insulating films 45a and 45b are continuous, a resist is used in the same manner as in the first embodiment to partially cover the top of the elliptical long axis and the surrounding protective insulating films 45a and 45b. To remove.

  Subsequently, as shown in FIG. 7E, an OLED film 47 is formed by vapor deposition on the transparent conductive film 42 exposed between the protective insulating films 45a and 45b in the two regions, and then the first embodiment. An upper electrode 48 made of the same two-layer structure conductive film as that of the embodiment is formed. Thereafter, as shown in FIG. 7 (f), the OLED film 47 and the upper electrode 48 are patterned using a resist pattern (not shown), and between the protective insulating films 45a and 45b formed in the two regions. Leave in the area.

  In this case, in the region between the protective insulating films 45a and 45b formed in the two regions on the fiber 41, the recess is formed by the film thickness of the protective insulating films 45a and 45b, so the OLED film 47 and the upper electrode 48 is sandwiched from the left and right by the protective insulating films 45a and 45b, and does not protrude from the surface of the protective insulating films 45a and 45b, or the amount thereof is small.

  Further, after the fiber 41 is cut to a predetermined length, the upper electrode 48 is connected to the solder bump 53 on the conductive data line segment wiring 52 formed on the insulating substrate 51 as shown in FIG. Pixels on a straight line of the display device are arranged.

  The OLED film 47 constituting the pixel on the fiber 41 as described above is formed in the recess between the protective insulating films 45a and 45b and does not protrude from the protective insulating films 45a and 45b, or the protruding amount of the upper electrode 48 is increased. Since the upper electrode 48 and the OLED film 47 are less likely to come into contact with the outside, the light-emitting element made of the OLED film 47 can be removed when winding on a reel, cutting the fiber 41, or attaching to the insulating substrate 51. It is less susceptible to damage and improves yield. As shown in FIG. 9, the cross-sectional shape of the fiber 41a may be circular.

In each of the above-described embodiments, the cross section of the fiber is approximately rectangular, elliptical, or circular, but is not limited thereto, and may be polygonal, cylindrical, or other shapes.
Moreover, although the light emitting element which has OLED was demonstrated in said embodiment, the light emitting element which has another light emitting layer may be sufficient. Further, an active element such as a transistor may be used instead of the light emitting element.

FIGS. 1A to 1F are sectional views (No. 1) showing a process of forming a light emitting element on a fiber according to the first embodiment of the present invention. FIGS. 2A to 2C are cross-sectional views (part 2) showing a step of forming a light emitting element on the fiber according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing another example of the light emitting element formed in the fiber according to the first embodiment of the present invention. FIG. 4 is a perspective view showing a fiber in which the light emitting device according to the second embodiment of the present invention is formed. FIGS. 5A to 5D are sectional views (No. 1) showing a process of forming a light emitting element on a fiber according to the second embodiment of the present invention. FIGS. 6A to 6D are cross-sectional views (part 2) showing a process of forming a light emitting element on the fiber according to the second embodiment of the present invention. FIGS. 7A to 7F are cross-sectional views showing a process of forming a light emitting element on the fiber according to the third embodiment of the present invention. FIG. 8 is a side view showing a state in which the light emitting element and the wiring on the insulating substrate are connected to the fiber according to the third embodiment of the present invention. FIG. 9 is a cross-sectional view showing another example of the light emitting element formed in the fiber according to the third embodiment of the present invention.

Explanation of symbols

1: Fiber 2: Transparent electrode 3, 4: Reflective film 5: Protective insulating film 7: OLED film 8: Upper electrode 20: Recess 21: Fiber 22: Transparent electrode 23, 24: Reflective film 25: Protective insulating film 27: OLED Film 28: Upper electrode 41, 41a: Fiber 42: Transparent electrode 43, 44: Reflective film 45a, 45b: Protective insulating film 47: OLED film 48: Upper electrode

Claims (5)

A light emitting element formed on the outer peripheral surface of the fiber;
A protective insulating film formed on the fiber and next to the light-emitting element,
A pixel structure of a display device using a fiber substrate, wherein a recess having the light emitting element as a bottom and the protective insulating film as a wall is formed in a region where the light emitting element is formed. The light emitting device includes a transparent electrode formed on the outer peripheral surface of the fiber, a light emitting layer formed on the transparent electrode, and an upper electrode formed on the light emitting layer. A pixel structure of a display device using the fiber substrate according to claim 1. The display using the fiber substrate according to claim 1, wherein an upper surface of the light emitting element is formed at a position lower than an upper surface of the protective insulating film with respect to a surface of the fiber. The pixel structure of the device. Forming a protective insulating film having an opening on the outer peripheral surface of the fiber;
Forming a light emitting element in the opening,
A method for manufacturing a pixel structure of a display device using a fiber substrate, wherein a recess having the light emitting element as a bottom and the protective insulating film as a wall surface is formed in a region where the light emitting element is formed. Forming a transparent conductive film to be the light emitting element on the fiber and then forming the protective insulating film on the fiber and exposing the transparent conductive film from the opening;
5. The fiber substrate according to claim 4, further comprising a step of sequentially forming a light emitting layer to be the light emitting element and an upper electrode on the transparent conductive film exposed from the opening . A method for manufacturing a pixel structure of a display device.

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