JP4264627B2 - Manufacturing method of flat panel display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
[0002]
The present invention relates to a method for producing a flat panel display in which so-called point light sources are arranged in a matrix, such as a light emitting diode display, a plasma display, a liquid crystal display, and an organic electroluminescence display.
[Prior art]
This type of flat panel display is expected to realize a high-performance and compact display. In particular, an LED display with excellent luminous efficiency can realize a high-brightness, high-contrast display by arraying red, green, and blue packaged LEDs in a two-dimensional array, such as various electronic devices. It can be used as a large-screen full-color display in the field.
[0003]
[Problems to be solved by the invention]
By the way, if a point light source with high luminous efficiency is used, the light source can be miniaturized. However, if the area of the light emitting region is made small in this way, the light source looks like a dot when the display is viewed nearby. On the contrary, there is a problem that the image becomes rough.
[0004]
For this reason, it has been studied to appropriately diffuse light emitted from a point light source. For example, in Patent Document 1, a light-absorbing binder in which fine light-transmitting beads are dispersed is applied to a light-transmitting sheet such as glass or resin and dried to diffuse light emitted from the display. It is disclosed to obtain a light diffusion sheet.
[0005]
However, the light diffusing sheet obtained from Patent Document 1 has a multi-step manufacturing process, and it is difficult to manage the process of uniformly dispersing fine beads.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-298205
[Means for Solving the Problems]
The present invention provides a manufacturing method of a flat panel display that can exhibit excellent light diffusibility by a simple manufacturing process and that enables miniaturization of light emitting elements by suitably dispersing light emitted from a point light source. Objective.
(1) According to the present invention, in a method of manufacturing a flat panel display in which dot-like light emitting elements are provided in a matrix on a substrate, pressure expansion / contraction is performed so as to directly or indirectly cover the dot-like light emitting elements. A step of forming a light diffusion layer by applying a functional resin, and a step of maintaining the substrate including the light diffusion layer in a low or high pressure environment with respect to the atmospheric pressure of the film formation step. A featured flat panel display manufacturing method is provided.
[0008]
In the present invention, a pressure-expandable resin is applied so as to directly or indirectly cover the point light emitting element, and the substrate is held in a low-pressure environment or a high-pressure environment before the resin is cured. Thereby, fine unevenness | corrugation is formed in the surface of the obtained light-diffusion layer. The light emitted from the point light-emitting element is appropriately diffused by the fine unevenness, and the image does not look rough even if the light-emitting element is miniaturized. In particular, since the fine irregularities are formed simply by forming the light diffusion layer and holding it in a reduced pressure environment or an increased pressure environment, the manufacturing process can be greatly simplified.
[0009]
In the present invention, the pressure-expandable resin constituting the light diffusion layer may be applied so as to directly cover the point light emitting element, or may be applied indirectly via another layer. . In short, the light diffusion layer of the present invention may be formed at a position where the emitted light passes through the light diffusion layer.
[0010]
In the present invention, the atmospheric pressure for holding the substrate including the light diffusion layer may be either a low pressure or a high pressure relative to the atmospheric pressure in the film forming process of the pressure-expandable resin. When pressure fluctuation is caused with respect to the atmospheric pressure during coating, irregularities are formed on the surface of the light diffusion layer.
[0011]
The pressure-expandable resin used in the present invention is a resin having a property of expanding or contracting in response to pressure fluctuation, and is not particularly limited, but examples thereof include cardo type polymers. As shown in FIG. 5, a cardo type polymer is a polymer having a structure in which a main chain M and a bulky side chain S are connected by one element (this corresponds to a cardo (latin meaning of a hinge)). It is a generic name. When a pressure-expandable resin typified by such a cardo type polymer is held in a low-pressure environment or a high-pressure environment, fine irregularities appear on the surface, and this can be cured or maintained in a low-pressure environment or a high-pressure environment. By curing it, a light diffusion layer having fine irregularities on the surface can be obtained.
[0012]
When maintaining the pressure-expandable resin in a low-pressure or high-pressure environment, the pressure difference and the arrival time are important, but depending on the characteristics of the pressure-expandable resin used and the surface roughness of the desired light diffusion layer, It is preferable to appropriately determine the pressure difference and the arrival time. In a preferred embodiment of the present invention, a pressure-expandable resin is applied under atmospheric pressure, and the pressure is reduced from atmospheric pressure to at least 1 × 10 ⁻³ Pa at an exhaust speed within 2 minutes. Thereby, fine irregularities having a surface roughness of 1 μm to 10 μm are formed on the surface of the light diffusion layer.
[0013]
The flat panel display according to the production method of the present invention is applicable to all flat panel displays in which so-called point light sources are arranged in a matrix, such as a light emitting diode display, a plasma display, a liquid crystal display, and an organic electroluminescence display. Can do.
(2) In particular, a point-like light emitting device having excellent luminous efficiency such as a light emitting diode display has a problem that an image looks rough when the light emitting device is miniaturized. It is preferable to do.
[0014]
That is, as an embodiment of the present invention, a step of arranging point light emitting elements on a substrate in a matrix, a step of forming an interlayer insulating layer on the substrate and the point light emitting elements, and a step of forming on the interlayer insulating layer a step of forming a light diffusion layer by coating and forming a wiring layer electrically connected to said point-like light emitting element, the pressure inflation and deflation resin in the interlayer insulating layer and the wiring layer, wherein And a step of holding a substrate including a light diffusing layer in a low or high pressure environment with respect to the atmospheric pressure of the film forming step.
[0015]
As another embodiment of the present invention, a step of arranging point light emitting elements on a substrate in a matrix form, and applying a pressure-expandable resin having insulation on the substrate and the point light emitting elements are applied. A step of forming a light diffusion layer, a step of forming a wiring layer electrically connected to the point light emitting element on the light diffusion layer, and a substrate including the light diffusion layer at an atmospheric pressure of the film formation step. method of manufacturing a flat panel display having the steps of holding the environment of low or high pressure is provided for.
[0016]
In the manufacturing method of the flat panel display according to these embodiments, in the former manufacturing method, a light diffusion layer made of a pressure-expandable resin is formed on the wiring layer and the interlayer insulating layer, whereas in the latter manufacturing method, Since the interlayer insulating layer for insulating the point light emitting element and the wiring layer is a light diffusion layer, the manufacturing method of the latter method becomes shorter.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
First Embodiment FIG. 1 is a process diagram showing a method for manufacturing a flat panel display according to the first embodiment of the present invention, and FIG. 2 shows a method for manufacturing a flat panel display according to the first embodiment of the present invention. It is a panel sectional view shown. In this example, the present invention will be described by taking an LED color display using red (R), blue (B) and green (G) light emitting diodes (hereinafter also referred to as LEDs) as point light emitting elements.
[0019]
One unit of the LED color display 1 according to this example is shown in FIG. 2 (F). On a substrate 11 made of glass or the like, any one of three LEDs 12 of red, blue and green, and this LED A drive circuit element 13 for driving is mounted using an adhesive or the like. The three color LEDs 12 are arranged vertically and horizontally in this order, and the LEDs 12 are arranged in a matrix as the entire substrate 11. A region in which the set of red, blue, and green LEDs 12 and their drive circuit elements 13 are mounted constitutes one pixel in the display 1.
[0020]
On the surface of the substrate 11 on which the LED 12 and the drive circuit element 13 are mounted, an interlayer insulating layer 14 for ensuring insulation from the LED 12 and the drive circuit element 13 is formed. The interlayer insulating layer 14 can be made of an insulating polymer or the like.
[0021]
A wiring layer 16 is formed on the surface of the interlayer insulating layer 14 via a connection hole (via hole) 15 for electrical connection with the contact of the LED 12 and the contact of the drive circuit element 13.
[0022]
The connection hole 15 is filled with a conductor at the same time when the wiring layer 16 is formed after forming a small hole in the interlayer insulating layer 14 using a laser beam or the like or by forming a small hole by a technique such as patterning.
[0023]
The wiring layer 16 is formed with a wiring pattern for supplying power to the LED 12 and the drive circuit element 13 and sending a control signal, and is formed by sputtering or patterning a conductor.
[0024]
In particular, in the display 1 of this example, a light diffusion layer 17 made of a cardo type polymer is formed on the surfaces of the interlayer insulating layer 14 and the wiring layer 16. The surface of the light diffusion layer 17 has fine irregularities with a surface roughness of 1 μm to 10 μm by a manufacturing method according to the present invention described later.
[0025]
Next, the manufacturing method of the LED color display 1 of this example is demonstrated.
First, as shown in FIG. 2A, the LEDs 12 and the drive circuit elements 13 are mounted on the upper surface of the glass substrate 11 in a matrix using an adhesive or the like (LED mounting step 101). Next, as shown in FIG. 2B, an insulating resin is applied to the upper surface of the substrate 11 on which the LED 12 and the drive circuit element 13 are mounted so as to cover the LED 12 and the drive circuit element 13, and is cured. The interlayer insulating layer 14 is formed (interlayer insulating layer forming step 102).
[0026]
Next, as shown in FIG. 3C, a connection hole 15 is opened at a predetermined position of the interlayer insulating layer 14 using a laser beam to expose the contact point between the LED 12 and the drive circuit element 13 (connection hole forming step 103). .
[0027]
Next, as shown in FIG. 4D, metal is deposited by sputtering on a predetermined position (position corresponding to the wiring pattern) on the surface of the interlayer insulating layer 14 and the connection hole 15, and the predetermined wiring pattern is formed by patterning. (Wiring layer forming step 104). Thereby, the connection hole 15 is filled with the metal and the wiring layer 16 is formed, and the LED 12 and the drive circuit element 13 are electrically connected to the wiring layer 16.
[0028]
Next, as shown in FIG. 5E, a cardo type polymer is applied by spin coating or the like on the upper surface of the interlayer insulating layer 14 on which the wiring layer 16 is formed to form a light diffusion layer 17 (light diffusion layer). Film forming step 105). In this state, the cardo type polymer is uncured. Moreover, the above process is performed in an atmospheric pressure environment.
[0029]
When the light diffusion layer forming step 105 is completed, the cardo type polymer constituting the light diffusion layer 17 is cured (light diffusion layer curing step 106). This curing step gives the amount of heat (temperature x time) required for curing the polymer when the cardo polymer used is a thermosetting polymer, and the cardo polymer used is a photocurable polymer. Gives the amount of light (intensity x time) required to cure the polymer.
[0030]
Finally, after the light diffusion layer 17 is cured, the substrate 11 in the state shown in FIG. 5E is put into a vacuum apparatus (not shown), and the exhaust speed within 2 minutes from atmospheric pressure to at least 1 × 10 ⁻³ Pa. The pressure is reduced and the state is maintained for a predetermined time (depressurized holding step 107). By this rapid pressure reduction, the surface of the uncured light diffusion layer 17 contracts as shown in FIG.
[0031]
In the display 1 obtained by the above steps, fine irregularities of about 1 μm to 10 μm are formed on the surface of the light diffusion layer 17, so that the emitted light emitted from the LED 12 passes through the light diffusion layer 17. This fine unevenness diffuses, and as a result, the area where the point light source of the LED 12 is visually recognized becomes large. Therefore, when the LED is miniaturized, for example, the conventional problem that the image looks rough even when the display is viewed nearby is solved.
[0032]
Although this inventor produced the LED display manufactured by the above process, the conventional LED display which does not form the light-diffusion layer 17, and visually evaluated the visual recognition state of the light source, the LED display of this example is There was no problem that the image became rough, and it was very good compared to the conventional LED display produced at the same time.
[0033]
Second Embodiment FIG. 3 is a process diagram showing a method for manufacturing a flat panel display according to a second embodiment of the present invention, and FIG. 4 shows a method for manufacturing a flat panel display according to the second embodiment of the present invention. It is a panel sectional view shown. In this example, the present invention will be described by taking an LED color display using red (R), blue (B) and green (G) light emitting diodes (hereinafter also referred to as LEDs) as point light emitting elements.
[0034]
One unit of the LED color display 1 according to this example is shown in FIG. 4 (E). On a substrate 11 made of glass or the like, any one of three colors of red, blue and green LEDs 12 and this LED are connected. A drive circuit element 13 for driving is mounted using an adhesive or the like. The three color LEDs 12 are arranged vertically and horizontally in this order, and the LEDs 12 are arranged in a matrix as the entire substrate 11. A region in which the set of red, blue, and green LEDs 12 and their drive circuit elements 13 are mounted constitutes one pixel in the display 1.
[0035]
On the surface of the substrate 11 on which the LED 12 and the drive circuit element 13 are mounted, an insulating light diffusion layer 17 is formed in order to ensure insulation from the LED 12 and the drive circuit element 13. The light diffusion layer 17 has an insulating property and can be made of a polymer having pressure expansion / contraction as described later. In this example, the light diffusion layer 17 is made of a cardo type polymer. The surface of the light diffusion layer 17 has fine irregularities with a surface roughness of 1 μm to 10 μm by a manufacturing method according to the present invention described later.
[0036]
A wiring layer 16 is formed on the surface of the light diffusion layer 17 through a connection hole (via hole) 15 for electrical connection with the contact of the LED 12 and the contact of the drive circuit element 13.
[0037]
The connection hole 15 is filled with a conductor at the same time when the wiring layer 16 is formed after forming a small hole in the light diffusion layer 17 using a laser beam or the like or by forming a small hole by a technique such as patterning.
[0038]
The wiring layer 16 is formed with a wiring pattern for supplying power to the LED 12 and the drive circuit element 13 and sending a control signal, and is formed by sputtering or patterning a conductor.
[0039]
Next, the manufacturing method of the LED color display 1 of this example is demonstrated.
First, as shown in FIG. 4A, the LEDs 12 and the drive circuit elements 13 are mounted on the upper surface of the glass substrate 11 in a matrix using an adhesive or the like (LED mounting step 201). Next, as shown in FIG. 2B, a cardo type polymer is applied to the upper surface of the substrate 11 on which the LED 12 and the drive circuit element 13 are mounted by spin coating so as to cover the LED 12 and the drive circuit element 13, and light diffusion is performed. Layer 17 is formed (light diffusion layer formation 202). In this state, the cardo type polymer is uncured. Moreover, the above process is performed in an atmospheric pressure environment.
[0040]
Next, as shown in FIG. 3C, a connection hole 15 is opened using a laser beam at a predetermined position of the light diffusion layer 17 to expose the contact between the LED 12 and the drive circuit element 13 (connection hole forming step 203). .
[0041]
Next, as shown in FIG. 4D, metal is deposited by sputtering on a predetermined position (position corresponding to the wiring pattern) on the surface of the light diffusion layer 17 and the connection hole 15, and the predetermined wiring pattern is formed by patterning. (Wiring layer forming step 204). Thereby, the connection hole 15 is filled with the metal and the wiring layer 16 is formed, and the LED 12 and the drive circuit element 13 are electrically connected to the wiring layer 16.
[0042]
When the wiring layer forming step 204 is completed, the cardo type polymer constituting the light diffusion layer 17 is cured (light diffusion layer curing step 205). This curing step gives the amount of heat (temperature x time) required for curing the polymer when the cardo polymer used is a thermosetting polymer, and the cardo polymer used is a photocurable polymer. Gives the amount of light (intensity x time) required to cure the polymer.
[0043]
Finally, when the light diffusion layer 17 is cured, the substrate 11 in the state shown in FIG. 4D is put into a vacuum apparatus (not shown), and the exhaust speed within 2 minutes from atmospheric pressure to at least 1 × 10 ⁻³ Pa. The pressure is reduced and the state is maintained for a predetermined time (depressurized holding step 206). As a result of this rapid pressure reduction, the surface of the uncured light diffusion layer 17 contracts as shown in FIG.
[0044]
In the display 1 obtained by the above steps, fine irregularities of about 1 μm to 10 μm are formed on the surface of the light diffusion layer 17, so that the emitted light emitted from the LED 12 passes through the light diffusion layer 17. This fine unevenness diffuses, and as a result, the area where the point light source of the LED 12 is visually recognized becomes large. Therefore, when the LED is miniaturized, for example, the conventional problem that the image looks rough even when the display is viewed nearby is solved.
[0045]
Moreover, since the manufacturing method of this example can omit an interlayer insulation layer formation process compared with 1st Embodiment mentioned above, an LED flat panel display can be obtained with a much simpler manufacturing process.
[0046]
Although this inventor produced the LED display manufactured by the above process, the conventional LED display which does not form the light-diffusion layer 17, and visually evaluated the visual recognition state of the light source, the LED display of this example is There was no problem that the image became rough, and it was very good compared to the conventional LED display produced at the same time.
[0047]
The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0048]
【The invention's effect】
As described above, according to the present invention, an excellent light diffusibility can be exhibited by a simple manufacturing process, and a flat panel display capable of miniaturizing a light emitting element by suitably dispersing light emitted from a point light source. A manufacturing method can be provided.
[Brief description of the drawings]
FIG. 1 is a process diagram showing a method of manufacturing a flat panel display according to a first embodiment of the present invention.
FIG. 2 is a panel cross-sectional view illustrating a method for manufacturing a flat panel display according to the first embodiment of the present invention.
FIG. 3 is a process diagram showing a method for manufacturing a flat panel display according to a second embodiment of the present invention.
FIG. 4 is a panel cross-sectional view illustrating a method for manufacturing a flat panel display according to a second embodiment of the present invention.
FIG. 5 is a schematic diagram showing the molecular structure of a cardo polymer according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Flat panel display 11 ... Board | substrate 12 ... LED element (point-like light emitting element)
DESCRIPTION OF SYMBOLS 13 ... Drive circuit element 14 ... Interlayer insulating layer 15 ... Connection hole 16 ... Wiring layer 17 ... Light diffusion layer

Claims (6)

In a method for manufacturing a flat panel display in which point light emitting elements are provided in a matrix on a substrate,
Applying a pressure-expandable resin so as to directly or indirectly cover the point light emitting element to form a light diffusion layer;
And a step of holding the substrate including the light diffusing layer in a low or high pressure environment relative to the atmospheric pressure of the film forming step.   The flat panel display manufacturing method according to claim 1, wherein the pressure-expandable resin is a cardo type polymer. Arranging the point light emitting elements in a matrix on the substrate; forming an interlayer insulating layer on the substrate and the point light emitting elements; and electrically connecting the point light emitting elements on the interlayer insulating layer. Forming a wiring layer to be connected; applying a pressure-expandable resin on the interlayer insulating layer and the wiring layer; forming a light diffusion layer; and forming a substrate including the light diffusion layer on the substrate. And a step of holding in a low or high pressure environment relative to the atmospheric pressure of the film process. Arranging a point light emitting element on a substrate in a matrix, applying a pressure-expandable resin having an insulating property on the substrate and the point light emitting element to form a light diffusion layer, and the light Forming a wiring layer electrically connected to the point light emitting element on the diffusion layer , and holding the substrate including the light diffusion layer in an environment of a low pressure or a high pressure relative to the atmospheric pressure of the film forming step; And a method of manufacturing a flat panel display.   The flat panel display manufacturing method according to claim 4, wherein the pressure-expandable resin is a cardo type polymer.   6. The method of manufacturing a flat panel display according to claim 4, wherein the point light emitting element is a light emitting diode.

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