JP2018006351A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device including a curved light-emitting surface, and to provide a highly reliable light-emitting device.SOLUTION: A plastic substrate is used, and a light-emitting element is formed in a state where the substrate is made flat. Subsequently, the substrate on which the light-emitting element is formed is placed, while being bent, on the surface of a support including the curved surface. Thereafter, a protective layer for protecting the light-emitting element, as it is, thus manufacturing a light-emitting device, such as a lighting device or a display device, including a curved light-emitting surface.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light emitting device and a manufacturing method thereof. In particular, the present invention relates to a light emitting device having a curved surface.

Research and development of organic EL (Electroluminescence) elements are actively conducted. The basic structure of an organic EL element (hereinafter also referred to as an EL element or a light-emitting element) is one in which a layer containing a light-emitting organic compound is sandwiched between a pair of electrodes. Light emission can be obtained from the light-emitting organic compound by applying a voltage to this element.

Examples of the light emitting device to which the organic EL element is applied include an illumination device and an image display device in which a thin film transistor is combined.

Since the organic EL element can be formed in a film shape, a large-area element can be easily formed, and the utility value as a surface light source that can be applied to illumination or the like is high. For example, Patent Document 1 discloses a lighting fixture using an organic EL element.

In addition, since an image display device to which an organic EL element is applied does not require a backlight that is necessary for a liquid crystal display device or the like, a thin, lightweight, high-contrast display device with low power consumption can be realized.

Examples of a method for forming a layer containing a light-emitting organic compound on a lower electrode formed on a substrate having an insulating surface when forming an organic EL element include a vacuum evaporation method and a coating method. Further, as a method for forming the lower electrode and the upper electrode, there are a coating method, a printing method and the like in addition to a vacuum deposition method and a sputtering method.

In recent years, diversification of the shape of the light emitting device has been demanded. One of them is a light-emitting device having a curved surface. By providing the light emitting device with a curved surface, the design and versatility are enhanced, and the degree of freedom in the place of installation and the shape of a member to be incorporated is increased. For example, a lighting device or a display device can be incorporated along a curved surface of a building or an automobile. Further, it can be used for various applications such as a wearable lighting device or display device such as a wristband, or a mobile terminal such as a mobile phone or a tablet terminal provided with a display portion having a curved surface.

JP 2009-130132 A

Here, when the lower electrode constituting the EL element, the layer containing a light-emitting organic compound, and the upper electrode are sequentially stacked, it is necessary to make each thickness uniform within the substrate surface. If these thicknesses are non-uniform in the substrate surface, the light emission luminance may be distributed in the substrate surface. In particular, where the thickness of the layer containing a light-emitting organic compound sandwiched between the electrodes is small, the luminance may increase due to electric field concentration, or a short circuit may occur. As a result, the voltage required for the above increases, and the luminance decreases or a non-light-emitting region is formed.

However, when an EL element is formed over a substrate having a curved surface, it has been difficult to uniformly form the thicknesses of the lower electrode, the layer containing a light-emitting organic compound, and the upper electrode that constitute the EL element. In the case of using a vacuum evaporation method or a sputtering method, the film formation rate of the film formed varies depending on the distance or angle between the evaporation source or target and the surface to be formed. In addition, the coating method and the printing method are extremely difficult to apply to a substrate having a curved surface due to the configuration of the apparatus.

The present invention has been made under such a technical background. Therefore, an object of the present invention is to provide a light-emitting device including a curved light-emitting surface. Another object is to provide a light-emitting device with high reliability.

  One embodiment of the present invention solves at least one of the above problems.

In order to solve the above problems, the present invention focuses on the material of the substrate on which the light emitting element is formed. A substrate having plasticity is used as a substrate, a light emitting element is formed in a state where the substrate is flat, and then the substrate on which the light emitting element is formed is curved and arranged on the surface of a support having a curved surface. . After that, a protective layer that protects the light-emitting element may be formed in that state.

In addition, the curved surface in this specification etc. means the curved surface obtained by deform | transforming without expanding and contracting a plane. In other words, it refers to a curved surface that can be in contact with a plane at any point on the curved surface. Here, the curved surface in this specification and the like does not include a curved surface (a so-called three-dimensional curved surface) that cannot be obtained by deforming a plane without expanding or contracting.

  Further, the “curved surface” in this specification and the like is synonymous with the curved surface.

By such a method, a light-emitting device such as an illumination device or a display device including a curved light-emitting surface can be manufactured.

The manufactured light-emitting device can maintain its form by a plastic substrate even if it is separated from the support after forming the protective layer. Therefore, the light emitting device can be used as a light emitting device including a curved light emitting surface similar to the curved surface of the support.

That is, a light-emitting device of one embodiment of the present invention includes a substrate having a curved surface and having plasticity, a light-emitting element which is formed over the surface of the substrate and includes a light-emitting layer between a pair of electrodes, and covers the light-emitting element. A sealing layer; and a protective layer in contact with the sealing layer.

The light-emitting device having such a configuration includes a curved light-emitting surface and a sealing layer that covers the light-emitting element;
By the protective layer in contact with the sealing layer, diffusion of impurities such as water from the outside is suppressed, so that a highly reliable light-emitting device is obtained.

According to another embodiment of the present invention, a light-emitting device includes a substrate having a curved surface, a plastic substrate, a light-emitting element and a transistor formed over the surface of the substrate and including a light-emitting layer between a pair of electrodes. A plurality of pixels; a sealing layer that covers the light-emitting element; and a protective layer that is in contact with the sealing layer.

In addition, the present invention can also be applied to an image display device provided with a plurality of pixels in which a transistor and a light emitting element are combined. Such a light-emitting device can be used by being attached to a curved wall or ceiling of a building or a vehicle, for example, and can realize an electronic device such as a portable terminal with high design.

The light-emitting device of another embodiment of the present invention is any of the above light-emitting devices, in which the substrate is
It is characterized by containing a metal or an alloy.

The light-emitting device of another embodiment of the present invention is any of the above light-emitting devices, in which the substrate is
It contains at least one selected from aluminum, copper, iron, nickel, titanium, and magnesium.

In this manner, heat dissipation can be increased by using a metal material or an alloy material with high thermal conductivity for the substrate over which the light-emitting device is provided. Therefore, since the heat generation of the light-emitting device can be suppressed even when used for a long time, a highly reliable light-emitting device can be obtained.

Another embodiment of the light-emitting device of the present invention is any of the above light-emitting devices, further including a planarization layer between the light-emitting element and the substrate.

In addition, in this manner, it is preferable to provide a planarization layer on the substrate side of the light-emitting element because uniformity of the thickness of the layer included in the light-emitting element is increased. In particular, a substrate including a metal or an alloy material often has a large undulation on the surface, and thus it is particularly effective to provide a planarization layer.

Another embodiment of the light-emitting device of the present invention is any one of the above light-emitting devices, in which the planarization layer includes a thermally conductive material.

The light-emitting device according to another embodiment of the present invention is any of the above light-emitting devices, wherein the planarization layer includes a resin in which particles of metal or an alloy are dispersed.

Further, by using a thermally conductive material for the planarization layer closer to the light emitting element as described above, heat generation from the light emitting element can be suppressed. In particular, when a heat conductive substrate containing a metal material or an alloy material is used, heat generated from the light emitting element can be transmitted to the substrate through the planarization layer, and thus heat generation of the light emitting device is further suppressed. be able to.

Another embodiment of the light-emitting device of the present invention is any one of the above light-emitting devices, in which the protective layer includes a glass layer.

In addition, it is preferable to apply a glass layer to the protective layer that protects the light-emitting element because diffusion of impurities such as water and oxygen can be extremely suppressed.

The light-emitting device according to another embodiment of the present invention is any of the above light-emitting devices, wherein the protective layer is a stacked body in which a glass layer, an adhesive layer, and a resin layer are sequentially stacked. .

Also, as described above, by adopting a structure in which a resin layer is laminated on a glass layer as a protective layer,
Generation of cracks and cracks in the glass layer can be suppressed, and a light emitting device with high strength can be obtained. At this time, it is particularly preferable that the glass layer be provided so as to face the light emitting element because diffusion of impurities from the resin layer can be suppressed.

In addition, in a method for manufacturing a light-emitting device of one embodiment of the present invention, a substrate having plasticity is arranged so that one surface is flat, and a first electrode, a light-emitting layer, The surface opposite to the one surface on which the light emitting element is formed on the support having a curved surface on the substrate on which the light emitting element is formed by laminating the two electrodes in order and forming the light emitting element So that it faces the support
A step of placing the substrate along a curved surface of the support, a step of dropping a curable material on one surface of the substrate, and a region of the substrate where no light emitting element is provided. In the region where the protective layer and the curable material are in contact with each other, the protective layer is arranged so that the material and part of the end portion are in contact
Fixing the protective layer, and bending the protective layer along one surface of the substrate so that the surface of the protective layer facing the substrate is in contact with the curable material in the region where the light-emitting element is provided; Curing a curable material and forming a sealing layer.

By such a method, a light-emitting device including a curved light-emitting surface can be manufactured. Further, when the light-emitting element is formed, the surface to be formed is in a flat state, whereby the uniformity of the thickness of the layers constituting the light-emitting element is increased, and the light emission luminance within the substrate surface can be made uniform. Moreover, when forming the protective layer, only the end portion is first bonded, and then curved along the substrate surface,
By adhering to a thermosetting material to be a later sealing layer, mixing of bubbles and the like between the protective layer and the sealing layer is suppressed, and a highly reliable light-emitting device can be manufactured.

In addition, in a method for manufacturing a light-emitting device of another embodiment of the present invention, a substrate having plasticity is arranged so that one surface is flat, and a first electrode, a light-emitting layer, and the like are formed on one surface of the substrate. The step of laminating the second electrode in order to form the light emitting element and the substrate on which the light emitting element is formed are opposite to the one surface on which the light emitting element is formed on a support having a curved surface. A step of bending and arranging a curved surface of the support so that the surface of the substrate faces the support, a step of dropping a photocurable material on one surface of the substrate, and a light-emitting element of the substrate Place the protective layer so that the photocurable material and a part of the edge are in contact with each other on the area where the protective layer is not provided, and irradiate the area where the protective layer and the photocurable material are in contact with each other. A step of curing a part of the conductive material to form a part of the sealing layer for bonding the protective layer and a part of the substrate; Bending the protective layer along one surface of the substrate so that the surface of the protective layer facing the substrate is in contact with the photocurable material in the region where the light emitting element is provided; and Irradiating the uncured part with light to form a sealing layer;
Have

In addition, such a method does not require a fixture for fixing a part of the protective layer and the substrate, so that a light-emitting device having a curved light-emitting surface can be easily manufactured.

In addition, in a method for manufacturing a light-emitting device of another embodiment of the present invention, a layer to be peeled is formed on a flat surface of a supporting substrate having a flat surface, and the light-emitting layer is formed between a pair of electrodes on the layer to be peeled. A step of forming a plurality of pixels each including a light emitting element and a transistor, and a layer on which the pixel is formed is peeled from the supporting substrate, and the pixel is formed on one surface of the plastic substrate. The step of transferring the release layer and the substrate including the pixel on the curved surface of the support so that the surface opposite to the one surface including the pixel faces the support on the support including the curved surface. And a step of dropping a curable material on one surface of the substrate, and a portion of the end portion of the curable material and the end portion on the region where the pixel of the substrate is not provided. A protective layer is placed in contact with the protective layer and the area where the protective layer is in contact with the curable material. Fixing the protective layer, and bending the protective layer along one surface of the substrate so that the surface of the protective layer facing the substrate is in contact with the curable material in the region where the pixels are provided. And a step of curing a curable material to form a sealing layer.

Further, by such a method, it is possible to form an image display device that includes a display portion that is curved and includes a plurality of pixels. In addition to a light-emitting element, a formation surface can be flat when a transistor is formed, so that it can be easily formed, and variation in electric characteristics of the transistor is suppressed, so that a highly reliable display device is obtained. be able to.

In addition, in a method for manufacturing a light-emitting device of another embodiment of the present invention, a layer to be peeled is formed on a flat surface of a supporting substrate having a flat surface, and the light-emitting layer is formed between a pair of electrodes on the layer to be peeled. A step of forming a plurality of pixels each including a light emitting element and a transistor, and a layer on which the pixel is formed is peeled from the supporting substrate, and the pixel is formed on one surface of the plastic substrate. The step of transferring the release layer and the substrate including the pixel on the curved surface of the support so that the surface opposite to the one surface including the pixel faces the support on the support including the curved surface. And a step of dropping a photocurable material on one surface of the substrate, and a region of the substrate where the pixels are not provided. Place the protective layer so that the part touches, and the area where the protective layer and the photocurable material touch By irradiating light, the cured part of the photocurable material,
A step of forming a part of a sealing layer for bonding the protective layer and a part of the substrate, and a surface of the protective layer facing the substrate is in contact with a photocurable material in a region where the pixel is provided As described above, the method includes a step of bending along one surface of the substrate, and a step of irradiating the uncured portion of the photocurable material with light to form a sealing layer.

  Further, in this way, it is preferable to fix a part of the protective layer using a photocurable material.

Further, after the light emitting device is manufactured, it may be used by being removed from the support, or may be used while being held on the support. For example, a member that serves as a casing of the lighting device or the electronic device may be used as a support, and the light emitting device may be manufactured over the support and then incorporated into the lighting device or the electronic device as it is.

Another embodiment of the method for manufacturing a light-emitting device of the present invention is characterized in that in any of the above-described methods for manufacturing a light-emitting device, a substrate containing a metal or an alloy is used.

Further, a method for manufacturing a light-emitting device according to another embodiment of the present invention is the method for manufacturing a light-emitting device according to any one of the above, wherein the substrate includes at least one selected from aluminum, copper, iron, nickel, titanium, and magnesium. It is characterized by using a substrate including the same.

As described above, when a metal material or an alloy material with high thermal conductivity is used as the substrate, a light-emitting device with improved heat dissipation can be manufactured. Further, a planarizing film on the surface on which the element of the substrate is formed,
Alternatively, a planarization film including a material having thermal conductivity may be used.

Another embodiment of the method for manufacturing a light-emitting device of the present invention is characterized in that, in any of the above-described methods for manufacturing a light-emitting device, the protective layer includes a glass layer.

A method for manufacturing a light-emitting device according to another embodiment of the present invention is the method for manufacturing a light-emitting device according to any one of the above, in which a laminate in which a glass layer, an adhesive layer, and a resin layer are sequentially stacked on a protective layer is provided. It is characterized by using.

Further, by such a manufacturing method, diffusion of impurities such as water and oxygen is suppressed, so that a highly reliable light-emitting device can be manufactured. Furthermore, a light-emitting device with improved mechanical strength can be manufactured by using a laminate of glass and resin.

Note that in this specification, an EL layer refers to a layer including at least a light-emitting organic compound (also referred to as a light-emitting layer) or a stacked body including a light-emitting layer provided between a pair of electrodes of a light-emitting element. .

Note that in this specification, a light-emitting device refers to an image display device, a light-emitting device, or a light source (including a lighting device). Further, a connector such as an FPC (Flexi) is connected to the light emitting device.
ble printed circuit) or TAB (Tape Automat)
ed Bonding) tape or TCP (Tape Carrier Packa)
ge), COG (Chip On Gla) on a substrate on which a printed wiring board is provided at the end of a TAB tape or TCP, or a substrate on which a light emitting element is formed.
It is assumed that all modules on which IC (integrated circuit) is directly mounted by the ss) method are included in the light emitting device.

ADVANTAGE OF THE INVENTION According to this invention, a light-emitting device provided with the curved light emission surface can be provided. In addition, a highly reliable light-emitting device can be provided.

6A and 6B illustrate a method for manufacturing a light-emitting device of one embodiment of the present invention. 6A and 6B illustrate a method for manufacturing a light-emitting device of one embodiment of the present invention. 6A and 6B illustrate a light-emitting device of one embodiment of the present invention. 6A and 6B illustrate a light-emitting device of one embodiment of the present invention. 6A and 6B illustrate a method for manufacturing a light-emitting device of one embodiment of the present invention. 6A and 6B illustrate a method for manufacturing a light-emitting device of one embodiment of the present invention. 4A and 4B each illustrate an application example of a light-emitting device of one embodiment of the present invention. The measurement result of the temperature characteristic which concerns on Example 1. FIG. 4 is a photographic image of a light emitting device according to Example 2. FIG.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below. Note that in structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated.

Note that in each drawing described in this specification, the size of each component, the thickness of a layer, or a region is
May be exaggerated for clarity. Therefore, it is not necessarily limited to the scale.

(Embodiment 1)
In this embodiment, a light-emitting device of one embodiment of the present invention and a manufacturing method thereof will be described with reference to drawings.

[Example of manufacturing method of light-emitting device]
Hereinafter, a method for manufacturing the light-emitting device of one embodiment of the present invention is described with reference to FIGS. 1 (A) to 1 (D) and FIGS. 2 (A) to 2 (E) are a schematic top view at each stage and a schematic cross-sectional view cut along a cutting line AB shown in the schematic top view. .

First, the substrate 101 is prepared. For the substrate 101, a plastic material is used, and at least a substrate having a flat surface is used.

In addition, it is preferable to use a metal or an alloy material for the substrate 101 because heat dissipation against heat generated from a light-emitting element formed later is increased. As a material used for the substrate 101, a metal material such as aluminum, copper, iron, nickel, titanium, or magnesium, or an alloy material including the metal material can be used. Stainless steel or duralumin may also be used.

In addition, it is preferable to use a substrate that has been subjected to an insulating treatment by oxidizing the surface of the conductive substrate or forming an insulating film on the surface. For example, an insulating film may be formed by using an electrodeposition method, a coating method such as a spin coating method or a dip method, a vapor deposition method, or a sputtering method, or it may be left in an oxygen atmosphere or heated. An oxide film may be formed on the surface of the substrate 101 by a known method such as an anodic oxidation method.

Subsequently, a planarization layer 113 is formed on the formation surface of the substrate 101. The planarization layer 113 is formed for the purpose of covering and planarizing the uneven shape on the surface of the substrate 101. As the planarization layer 113, an insulating material can be used. For example, an organic material such as polyimide, acrylic, epoxy, or benzocyclobutene can be used.

The planarization layer 113 can be formed by a coating method such as a spin coating method or a dip method, a discharge method such as an inkjet method or a dispensing method, a printing method such as screen printing, or the like.

Alternatively, an organic resin in which particles made of a metal or an alloy material are dispersed can be used for the planarization layer 113. By using the planarization layer 113 in which a conductive material is dispersed in this manner, heat generated from a light-emitting element to be formed later can be efficiently conducted to the substrate 101, so that heat dissipation can be further improved. . Further, in order to improve flatness or insulating properties, an organic resin may be further stacked on the organic resin in which conductive particles are dispersed.

When the surface of the substrate 101 is insulated and the flatness thereof is high, the planarizing layer 1
13 may not be provided.

  Subsequently, the first electrode layer 103 and the wiring 111 are formed over the planarization layer 113.

Part of the first electrode layer 103 serves as one electrode constituting the light-emitting element. Also wiring 1
Reference numeral 11 denotes a wiring for supplying electric power to a second electrode constituting a light emitting element to be formed later. Here, each of the first electrode layer 103 and the wiring 111 also functions as an extraction electrode for supplying power from the outside.

The first electrode layer 103 and the wiring 111 may be formed using the same material or different materials. In at least a region where the light-emitting element is formed over the first electrode layer 103,
A material having reflectivity with respect to light emission from the EL layer 105 to be formed later is used. Alternatively, a material having high light reflectivity may be stacked in a region where the light-emitting element is formed over the first electrode layer 103.

Examples of the material used for the first electrode layer 103 and the wiring 111 include aluminum, gold,
A metal such as platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy containing these metals can be used. Further, lanthanum, neodymium, germanium, or the like may be added to a metal or alloy containing these metal materials. In addition, an alloy containing aluminum such as an alloy of aluminum and titanium, an alloy of aluminum and nickel, an alloy of aluminum and neodymium (aluminum alloy), an alloy containing silver such as an alloy of silver and copper, or an alloy of silver and magnesium is used. You can also An alloy of silver and copper is preferable because of its high heat resistance. Furthermore, by stacking a metal film or a metal oxide film in contact with the aluminum alloy film, oxidation of the aluminum alloy film can be suppressed. Examples of the material for the metal film and metal oxide film include titanium and titanium oxide. Alternatively, a film formed using the light-transmitting material and a film formed using a metal material may be stacked. For example, a laminated film of silver and indium tin oxide, a laminated film of an alloy of silver and magnesium and indium tin oxide, or the like can be used.

The first electrode layer 103 and the wiring 111 can be formed by a sputtering method, a vacuum evaporation method, a printing method such as a screen printing method, a discharge method such as an inkjet method or a dispensing method, a plating method, or the like. In particular, it is preferable to form these simultaneously using a screen printing method.

  A schematic top view and a schematic cross-sectional view at this stage correspond to FIG.

Subsequently, the first electrode layer 103 and part of the ends of the wiring 111 are covered, and the first electrode layer 1 is covered.
03 and an insulating layer 115 having an opening exposing a part of the wiring 111 are formed.

The insulating layer 115 can be formed by a discharge method such as an inkjet method or a dispense method, a printing method such as screen printing, or the like. Further, a photolithography method may be used.

The insulating layer 115 has a curved surface having a radius of curvature (0.2 μm to 3 μm) at the upper end or the lower end of the insulating layer 115 in order to improve the coverage of the second electrode layer 107 to be formed later. Is preferred. Further, as a material of the insulating layer 115, in addition to the same material as the planarization layer 113, a negative photosensitive resin that becomes insoluble in an etchant by light irradiation, or becomes soluble in an etchant by light irradiation. An organic compound such as a positive photosensitive resin or an inorganic compound such as silicon oxide or silicon oxynitride can be used.

  A schematic top view and a schematic cross-sectional view at this stage correspond to FIG.

Subsequently, the EL layer 105 is formed over the first electrode layer 103. The EL layer 105 is formed by a vacuum evaporation method, a discharge method such as an inkjet method or a dispense method, or a coating method such as a spin coat method.

The EL layer 105 may include at least a layer containing a light-emitting organic compound (hereinafter also referred to as a light-emitting layer), and may be a single layer or a plurality of layers. As an example of a configuration composed of a plurality of layers, a configuration in which a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are stacked from the anode side can be given as an example. Note that these layers other than the light-emitting layer are not necessarily provided in the EL layer 105. Further, these layers can be provided in an overlapping manner. Specifically, a plurality of light emitting layers may be provided to overlap with the EL layer 105, or a hole injection layer may be provided to overlap with the electron injection layer. In addition to the charge generation layer, other configurations such as an electronic relay layer can be added as appropriate as an intermediate layer. For example, it is good also as a structure which laminates | stacks the light emitting layer which exhibits a different luminescent color. For example, white light emission can be obtained by laminating two or more light emitting layers having a complementary color relationship.

  A schematic top view and a schematic cross-sectional view at this stage correspond to FIG.

Subsequently, a second electrode layer 107 that covers the EL layer 105 and is electrically connected to the wiring 111 is used.
Form.

The second electrode layer 107 is formed using a material that transmits light emitted from the EL layer 105.

As the light-transmitting material, indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide to which gallium is added, or the like can be used. Alternatively, graphene may be used. As the conductive layer, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or an alloy containing any of these materials can be used. Alternatively, nitrides of these metal materials (for example, titanium nitride) may be used. Note that in the case where a metal material (or a nitride thereof) is used, it may be thinned so as to have translucency. In addition, a stacked film of the above materials can be used as a conductive layer. For example, the use of a laminated film of an alloy of silver and magnesium and indium tin oxide is preferable because the conductivity can be increased.

The second electrode layer 107 is formed by an evaporation method, a sputtering method, or the like. others,
It can be formed using a discharge method such as an inkjet method, a printing method such as a screen printing method, or a plating method.

Note that when the above-described conductive oxide having a light-transmitting property is formed by a sputtering method,
When the conductive oxide is formed in an atmosphere containing argon and oxygen, the light-transmitting property can be improved.

In the case where the conductive oxide film is formed over the EL layer, the first conductive oxide film formed in an atmosphere containing argon with a reduced oxygen concentration and the atmosphere containing argon and oxygen are formed. A stacked film of the second conductive oxide film is preferable because film formation damage to the EL layer can be reduced. Here, it is particularly preferable that the purity of the argon gas used when forming the first conductive oxide film is high. For example, an argon gas having a dew point of −70 ° C. or lower, preferably −100 ° C. or lower is preferably used. .

In this manner, the light-emitting element 120 in which the first electrode layer 103, the EL layer 105, and the second electrode layer 107 are stacked is formed. Here, the configuration formed on the substrate 101 is collectively referred to as a light emitting device 110.

In each step of forming the light emitting device 110, the substrate 101 is formed so as to have a flat surface. Therefore, the thickness of each layer constituting the light emitting device 110,
Controllability such as shape and position can be improved. In particular, since the thicknesses of the first electrode layer 103, the EL layer 105, and the second electrode layer 107 included in the light-emitting element 120 can be uniform, a light-emitting device with improved uniformity of light emission luminance is manufactured. can do.

Further, a protective film may be formed over the second electrode layer 107. By forming the protective film, diffusion of impurities such as water and oxygen into the light-emitting element 120 is suppressed, so that a highly reliable light-emitting device can be obtained. As the protective film, a material having translucency and a barrier property against water and oxygen is used. For example, a semiconductor such as silicon or a metal oxide or nitride such as aluminum may be used.

  A schematic top view and a schematic cross-sectional view at this stage correspond to FIG.

Subsequently, as illustrated in FIG. 2A, the substrate 101 on which the light emitting device 110 is formed is placed over the support 121. For the sake of clarity, the light-emitting device 110 is shown in a simplified manner in the following drawings.

The support 121 has a curved surface. Moreover, it is preferable that the cross section is comprised by the continuous curve. Although FIG. 2A shows the support 121 having a convex arcuate surface shape, it can take various shapes other than this. For example, the cross-sectional shape may be an arc shape having a concave shape, or a wave shape.

The substrate 101 is disposed along the curved surface of the support 121. Here, since the substrate 101 has plasticity, the substrate 101 can be kept in its shape after being arranged along the curved surface of the support 121.

Further, the support 121 and the substrate 101 may be fixed using an adhesive material or a fixture. Note that when the light emitting device 100 is used after being detached from the support 121, it is fixed with a weakly viscous adhesive material or a detachable fixture.

Here, the radius of curvature of the support 121 to be used can be a radius of curvature that is large enough to prevent cracks and cracks from occurring in each layer of the light emitting device 110 when the substrate 101 is curved. Further, a support having a smaller radius of curvature can be used as each layer constituting the light emitting device 110 is formed thinner.

Subsequently, a sealing material 122 is applied over the curved substrate 101 (FIG. 2B). Sealing material 1
22 is formed by, for example, dropping on a region covering at least the light emitting element 120 and a region where a protective layer is formed later. At this time, the substrate 1 of the first electrode layer 103 and the wiring 111 is also shown.
The sealing material 1 is exposed so that a region functioning as an extraction electrode provided on the outer peripheral side of 01 is exposed.
22 is applied.

As the sealing material 122, a photocurable organic resin is used. For the sealing material 122, a material having a light-transmitting property against at least light emitted from the light-emitting element after being cured by light irradiation is used.

For example, PVC (polyvinyl chloride), acrylic, polyimide, epoxy resin, silicone resin, PVB (polyvinyl butyral), or EVA (ethylene vinyl acetate) can be used as the sealing material 122.

  Subsequently, the protective layer 125 is provided in contact with part of the sealing material 122 (FIG. 2C).

The protective layer 125 is formed using a material that transmits at least light emitted from the light-emitting element 120. For example, a sheet-like organic resin or a flexible glass material can be used.

The protective layer 125 can be used by stacking a plurality of layers. In particular, when the glass layer is used, the barrier property against water and oxygen can be improved and a highly reliable light-emitting device can be obtained.

In particular, as the protective layer 125, a sheet in which a glass layer, an adhesive layer, and an organic resin layer are stacked from the side close to the light emitting element is preferably used. The thickness of the glass layer is 20 μm or more and 20
The thickness is 0 μm or less, preferably 25 μm or more and 100 μm or less. The glass layer having such a thickness can simultaneously realize a high barrier property and flexibility against water and oxygen. The thickness of the organic resin layer is 10 μm or more and 200 μm or less, preferably 20 μm or more and 50 μm or less. By providing such an organic resin layer outside the glass layer, it is possible to suppress breakage and cracking of the glass layer and improve mechanical strength. By applying such a composite material of glass material and organic resin to the protective layer 125, a highly reliable and curved light-emitting device can be obtained.

First, the protective layer 125 is provided on the substrate 101 at least in a region outside the region where the light emitting element 120 is provided so that the end portion thereof is in contact with the sealing material 122. At this time, as illustrated in FIG. 2C, it is preferable that portions other than the end portion of the protective layer 125 are not in contact with the sealing material 122.

Subsequently, the region where the protective layer 125 and the sealing material 122 are in contact with each other is irradiated with light 127, the sealing material 122 in the region is cured, and the substrate 101 and the protective layer 125 are bonded. At this time, a part of the region where the sealing material 122 is cured becomes the sealing layer 123.

Thereafter, the protective layer 125 is brought into close contact with the protective layer 125 gradually being curved with the region where the protective layer 125 and the sealing layer 123 are bonded as a fulcrum. In this manner, after the end portions of the protective layer 125 are once bonded, the bonding is gradually performed from the bonded portion toward the outside, whereby bubbles are suppressed from being taken in, and a highly reliable light-emitting device is obtained. be able to.

For this bonding, it is preferable that the protective layer 125 and the sealing material 122 are brought into close contact with each other by using, for example, a roller-shaped pressing member so as to roll the bonded portion to the starting point. At this time, it is preferable to control the distance between the protective layer 125 and the substrate 101 to be constant.

Subsequently, as illustrated in FIG. 2D, light 1 is applied to the sealing material 122 from above the protective layer 125.
27, the sealing material 122 is cured, and the sealing layer 123 is formed.

At this time, the light 127 may be irradiated to the sealing material 122 in a state where the protective layer 125 is fixed so as not to be peeled off.

Through the above steps, the light-emitting device 100 including a curved light-emitting surface can be formed on the support 121.

In the above, a photocurable organic resin is used as the material used for the sealing material 122. However, the present invention is not limited to this, and a cured resin that cures at room temperature, such as a thermosetting organic resin or a two-component mixed resin. Can also be used.

In the case where a thermosetting resin is used for the sealing material 122, a part of the protective layer 125 is part of the sealing material 122.
Then, the contact portion may be locally heated and cured. Then protective layer 1
25 is bent and brought into close contact with the sealing material 122, and then heated and cured as a whole. As a method of locally heating, the light from the lamp may be locally irradiated or a heat source such as a heater may be brought closer. As a method for heating the whole, a hot plate, an oven, or the like may be used in addition to a lamp or a heater.

In the case where a resin that cures at room temperature is used for the sealing material 122, first, the resin is applied to a region outside the region where the light-emitting element 120 is provided in advance, and is in close contact with a part of the protective layer 125. Cure in the wet state. After that, a resin may be applied again to a region overlapping with the light-emitting element 120, and the protective layer 125 may be in close contact with the resin while being bent and cured.

In the above description, the method for curing the sealing material 122 in close contact with the protective layer 125 and bonding the protective layer 125 and the substrate 101 in a region outside the region where the light emitting element 120 is provided has been described. However, at least when the protective layer 125 is curved, it is only necessary to fix the protective layer 125 so that the position of the protective layer 125 does not shift in the region, and the method is not limited to this method.

For example, after the sealing material 122 is applied over the substrate 101, the protective layer 125 is disposed in close contact with the sealing material 122 in a region outside the region where the light emitting element 120 is provided. The protective layer 125 may be bent in a state where the portion is fixed to the substrate 101 and adhered to the sealing material 122, and then the entire sealing material 122 may be cured. The end of the protective layer 125 is placed on the substrate 10.
As a method of fixing to 1, a method of pressing from above the protective layer 125 using a pressing member, a method of fixing the end of the protective layer 125 using a fixing tool such as a tape or the like directly to the support 121 or the substrate 101, etc. There is.

When such a method is used, the kind of the curable material used for the sealing material 122 is not limited, and a photocurable resin, a thermosetting resin, a curable resin that cures at room temperature, or the like can be used as appropriate. .

Note that the light-emitting device 100 may be used in a state of being supported by the support 121 as illustrated in FIG. 2D, or may be used by being detached from the support 121 as illustrated in FIG. 2E. May be.

As a case where the light emitting device 100 is used while being supported by the support 121, for example, a member that becomes a housing of an illumination device or an electronic device is used as the support 121, and the light emitting device 100 is manufactured on the support 121. Alternatively, it may be incorporated in a lighting device or an electronic device as it is.

In this manner, by using a material having plasticity for the substrate 101, the process of forming the light emitting device 110 on the substrate 101 can be performed in a state where the formation surface is flat, and thus the luminance distribution is improved. A light-emitting device can be obtained.

Further, since the step of bonding the substrate 101 and the protective layer 125 can be performed in a curved state, stress due to the protective layer 125 generated after the bonding can be reduced. Here, for example, when the entire light-emitting device 100 is bent after the protective layer 125 is bonded in a flat state, the protective layer 125 itself or a sealing layer or a light-emitting device fixed to the protective layer 125 is used. Since a large stress is generated, cracks and cracks are generated in these. By bonding the protective layer in such a curved state, such stress can be relieved, so that a highly reliable light-emitting device can be obtained.

In particular, in the case where a material including a glass layer is used as the sealing layer, if the sealing layer itself is flexible if the substrate is bonded in a flat state and then largely curved, the sealing layer itself is flexible. Since the stop layer is bonded to the substrate, the stress applied to the glass layer is increased, and there is a high possibility that a crack will occur. On the other hand, in the case of using the above method, since the sealing layer and the substrate are not bonded at the time of bending the sealing layer, there is no risk of cracking even if the sealing layer is greatly bent, and as a result, the light emitting surface with a small curvature radius. And a highly reliable light-emitting device in which the diffusion of impurities is suppressed by the glass layer.

[Modification]
In addition, by changing the shape of the support 121, light emitting devices having various shapes can be easily manufactured. For example, as shown in FIG. 3, a wave-shaped light emitting device 100 can be obtained.

In this embodiment mode, the top surface shape of the light emitting device 110 is a square, but the present invention is not limited to this, and light emitting devices having various shapes may be used. A variety of shapes such as a circle including an ellipse, a polygon, a figure surrounded by curves with different curvatures, and a figure enclosed by curves and straight lines can be used, so high design can be realized.

Further, since a sheet-like material can be used for the substrate 101 and the protective layer 125, R
Suitable for the all To Roll method, a light emitting device having a large area can be easily manufactured.

This embodiment can be implemented in combination with any of the other embodiments and examples described in this specification as appropriate.

(Embodiment 2)
In this embodiment, the case where an image display device is used as the light-emitting device in the method for manufacturing the light-emitting device exemplified in the above embodiment will be described with reference to drawings.

In the following description, the description overlapping with the contents described in Embodiment 1 will be omitted or simplified.

An image display device formed over the substrate 101 having plasticity includes a plurality of pixels each including at least one light emitting element. As an image display device, a passive matrix type image display device in which one pixel is composed of one light emitting element, or an active matrix type element composed of a light emitting element and at least one transistor in one pixel. There is an image display device.

Hereinafter, an active matrix image display device will be described as an example of an image display device that can be used in the method for manufacturing a light-emitting device of one embodiment of the present invention.

[Configuration example]
FIG. 4A shows a part of a pixel of the image display device 150, and FIG.
It is the cross-sectional schematic in the cross section cut | disconnected by the cutting line CD in A).

In the image display device 150 illustrated in FIG. 4A, a plurality of source wirings 151 are arranged in parallel with each other and spaced apart from each other, and a plurality of gate wirings 15 intersecting the source wiring 151.
2 are arranged parallel to each other and spaced apart from each other. An area surrounded by the source wiring 151 and the gate wiring 152 becomes one pixel of the image display device 150, which is arranged in a matrix.

Each pixel includes a transistor 153, a transistor 154, and a transistor 15
4 is formed.

  As the substrate 101, a substrate similar to that in Embodiment 1 can be used.

In FIG. 4B, the substrate 101, the adhesive layer 161 provided over the substrate 101, and the adhesive layer 1
6 is a schematic cross-sectional view including an insulating layer 163 provided over the transistor 61, a transistor 154 formed over the insulating layer 163, and the light-emitting element 120 electrically connected to the transistor 154.

The transistor 154 includes a gate electrode layer, a gate insulating layer, a semiconductor layer, and a source electrode layer and a drain electrode layer.

The structure of the transistor constituting the image display device 150 is not particularly limited. For example, a staggered transistor or an inverted staggered transistor may be used. Also,
Either a top-gate or bottom-gate transistor structure may be employed.

As a semiconductor material used for the transistor, a semiconductor material such as silicon or germanium may be used, or an oxide semiconductor material containing at least one of indium, gallium, and zinc may be used. There is no particular limitation on the crystallinity of the semiconductor used for the transistor, and the semiconductor is a noncrystalline semiconductor or a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having part of a crystalline region). Either may be used. The use of a crystalline semiconductor is preferable because deterioration of transistor characteristics is suppressed.

The light-emitting element 120 can have a structure similar to that of Embodiment 1 and the first electrode layer 103.
The EL layer 105 and the second electrode layer 107 are sequentially stacked. In addition, the first electrode 103 is formed over the source electrode layer or the drain electrode layer of the transistor 154 with the insulating layer 165.
And through an opening provided in the insulating layer 167.

In addition, an insulating layer 166 covering the light emitting element 120 is formed. The insulating layer 166 is provided to prevent impurities such as water and oxygen from diffusing into the light-emitting element. For example, an inorganic insulating material such as an oxide or nitride of a semiconductor such as silicon or an oxide or nitride of a metal such as aluminum can be used.

A light emitting element 120 of an adjacent pixel includes an EL layer 105 that exhibits different emission colors. For example, by using the light-emitting element 120 including the EL layer 105 that emits red (R), green (G), and blue (B), the image display device 150 capable of full-color display can be obtained. In addition to the above three colors, a light-emitting element 120 including an EL layer 105 that emits yellow (Y) or white (W) may be provided.

In addition, the openings provided in the insulating layer 165 and the insulating layer 167, and the first electrode layer 10
3, an insulating layer 115 is formed. The structure of the insulating layer 115 can be the same as that of Embodiment 1.

The insulating layer 165 functions as a planarization layer for suppressing the influence of the uneven shape by a transistor or the like provided below. By providing the insulating layer 165, a short circuit or the like of the light-emitting element 120 can be suppressed. The insulating layer 165 can be formed using a photosensitive organic resin or the like.

The insulating layers 168 and 169 in contact with the semiconductor layer of the transistor and the insulating layer 167 covering the transistor preferably suppress diffusion of impurities into the semiconductor included in the transistor. For these insulating layers, for example, an oxide or nitride of a semiconductor such as silicon, or an oxide or nitride of a metal such as aluminum can be used. Alternatively, a stacked film of such an inorganic insulating material or a stacked film of an inorganic insulating material and an organic insulating material may be used.

Here, an insulating material can be used for the adhesive layer 161. The adhesive layer 161 is
Similar to the planarization layer 113 exemplified in Embodiment 1, the surface of the substrate 101 has a function of covering the uneven shape. In addition, when a structure including an organic resin in which particles made of a metal or an alloy material are dispersed, heat generated from the light-emitting element 120 can be efficiently conducted to the substrate 101, and thus heat dissipation can be further improved.

  The above is the description of the configuration example of the image display device 150.

[Example of production method]
Hereinafter, a method for manufacturing the image display device 150 will be described with reference to the drawings.

First, the separation layer 173 and the insulating layer 163 are stacked over the supporting substrate 171 (FIG. 5).
(A)). The insulating layer 163 is preferably formed continuously after being formed without being exposed to the air after the release layer 173 is formed, because mixing of impurities can be suppressed.

As the support substrate 171, a substrate having a flat surface is used. For example, a substrate made of glass, quartz, sapphire, ceramic or metal can be used. In addition, an organic resin substrate such as a plastic may be used in the case where it has heat resistance with respect to the temperature required for the manufacturing process. Here, in the case of using a plastic substrate, the peeling layer 173 may be unnecessary.

In this embodiment mode, the separation layer 173 is formed in contact with the support substrate 171, but when a glass substrate is used as the support substrate 171, a silicon oxide film or an oxidation film is formed between the support substrate 171 and the separation layer 173. By forming an insulating layer such as a silicon nitride film, a silicon nitride film, or a silicon nitride oxide film, contamination from the glass substrate can be prevented, which is more preferable.

The peeling layer 173 includes tungsten, molybdenum, titanium, tantalum, niobium, nickel,
It is a single layer or a laminated layer made of an element selected from cobalt, zirconium, ruthenium, rhodium, palladium, osmium, iridium and silicon, an alloy material containing the element, or a compound material containing the element. The crystal structure of the layer containing silicon may be any of amorphous, microcrystalline, and polycrystalline.

The peeling layer 173 can be formed by a sputtering method, a plasma CVD method, a coating method, a printing method, or the like. Note that the coating method includes a spin coating method, a droplet discharge method, and a dispensing method.

In the case where the separation layer 173 has a single-layer structure, a tungsten layer, a molybdenum layer, or a layer containing a mixture of tungsten and molybdenum is preferably formed. Alternatively, a layer containing tungsten oxide or oxynitride, a layer containing molybdenum oxide or oxynitride, or a layer containing an oxide or oxynitride of a mixture of tungsten and molybdenum is formed. Note that the mixture of tungsten and molybdenum corresponds to, for example, an alloy of tungsten and molybdenum.

In the case where a stacked layer structure including a layer containing tungsten and a layer containing tungsten oxide is formed as the separation layer 173, a layer containing tungsten is formed, and an insulating layer formed using an oxide is formed thereover. Thus, the fact that a layer containing an oxide of tungsten is formed at the interface between the tungsten layer and the insulating layer may be utilized. Alternatively, the surface of the layer containing tungsten may be subjected to thermal oxidation treatment, oxygen plasma treatment, treatment with a solution having strong oxidizing power such as ozone water, or the like to form the layer containing tungsten oxide. The plasma treatment and the heat treatment may be performed in an atmosphere of oxygen, nitrogen, nitrous oxide alone, or a mixed gas atmosphere of the gas and other gases. By changing the surface state of the release layer 173 by the plasma treatment or the heat treatment,
The adhesion between the peeling layer 173 and the insulating layer 163 to be formed later can be controlled.

Next, the insulating layer 163 is formed over the separation layer 173. The insulating layer 163 is preferably formed using a single layer or multiple layers of silicon nitride, silicon oxynitride, silicon nitride oxide, or the like.

The insulating layer 163 can be formed by a sputtering method, a plasma CVD method, a coating method, a printing method, or the like. For example, the film formation temperature is 250 ° C. or higher by the plasma CVD method.
By forming the film at 00 ° C. or lower, a dense and extremely low water-permeable film can be obtained. Note that the insulating layer 163 has a thickness of 10 nm to 3000 nm, and more preferably 200 nm to 15 nm.
00 nm or less is preferable.

Subsequently, a transistor 153 (not shown), a transistor 154, and the like are formed over the insulating layer 163.
A source wiring 151, a gate wiring 152 (not shown), and the like are formed. Here, a bottom-gate transistor is manufactured.

First, after forming a conductive film to be a gate electrode layer, unnecessary portions of the conductive film are removed using a known photolithography method, and a gate electrode layer is formed. Note that a wiring formed of the same layer as the gate electrode layer is formed at the same time.

The gate electrode layer is formed of a single layer or stacked layers using a metal material such as molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, neodymium, scandium, or an alloy material containing these elements. Can do.

Next, an insulating layer 169 to be a gate insulating layer is formed over the gate electrode layer. The insulating layer 169 can be formed using a single layer or a stack of silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or aluminum oxide by a plasma CVD method, a sputtering method, or the like. For example, plasma CVD using SiH ₄ or N ₂ O as a film forming gas
A silicon oxynitride film may be formed by a method.

  Next, a semiconductor film is formed, and an island-shaped semiconductor layer is formed using a photolithography method.

The semiconductor film can be formed using a silicon semiconductor or an oxide semiconductor. As the silicon semiconductor, single crystal silicon, polycrystalline silicon, microcrystalline silicon, or the like can be given. As the oxide semiconductor, for example, an oxide semiconductor containing at least one of In, Ga, and Zn can be used. Typically, an In—Ga—Zn—O-based metal oxide can be given. However, as the semiconductor layer, an oxide semiconductor that is an In—Ga—Zn—O-based metal oxide is used to form a semiconductor layer with a low off-state current, so that a leakage current when the light-emitting element to be formed later is off Can be suppressed, which is preferable.

Subsequently, after an insulating film covering the semiconductor layer is formed, an insulating layer 168 in which an opening exposing a part of the semiconductor layer is formed by photolithography.

Then, after forming a conductive film, a source electrode and a drain electrode are formed using a photolithography method. At the same time, a wiring formed in the same layer as the source electrode and the drain electrode is formed.

As the conductive film used for the source electrode and the drain electrode, for example, Al, Cr, Cu, T
A metal film containing an element selected from a, Ti, Mo, and W, or a metal nitride film (a titanium nitride film, a molybdenum nitride film, or a tungsten nitride film) containing the above-described elements can be used. Further, a refractory metal film such as Ti, Mo, W or the like or a metal nitride film thereof (titanium nitride film, molybdenum nitride film, tungsten nitride film) is provided on one or both of the lower side or the upper side of a metal film such as Al or Cu. It is good also as a structure which laminated | stacked. The conductive film used for the source and drain electrode layers may be formed using a conductive metal oxide. Examples of conductive metal oxides include indium oxide (such as In ₂ O ₃ ), tin oxide (such as SnO ₂ ), zinc oxide (ZnO),
Indium tin oxide (such as In ₂ O ₃ —SnO ₂ ), indium zinc oxide (In ₂
O ₃ —ZnO or the like), or a metal oxide material containing silicon oxide can be used.

  Through the above process, the transistor 154 is formed.

Next, the insulating layer 167 is formed over the semiconductor layer, the source electrode, and the drain electrode. As the insulating layer 167, an inorganic insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film can be used.

  Next, the insulating layer 165 is formed over the insulating layer 167 (see FIG. 5B).

As the insulating layer 165, an insulating film having a planarization function is preferably selected in order to reduce surface unevenness due to the transistor. For example, an organic material such as polyimide, acrylic, or benzocyclobutene can be used. In addition to the above organic materials, low dielectric constant materials (l
ow-k material) or the like can be used. Note that the insulating layer 165 may be formed by stacking a plurality of insulating films formed using these materials.

Next, an opening reaching the source electrode or the drain electrode is formed in the insulating layer 165 and the insulating layer 167 by photolithography. The opening method may be selected as appropriate, such as dry etching or wet etching. Alternatively, a photosensitive material is used for the insulating layer 165, and
After the insulating layer 165 having an opening is formed by a photolithography method, the opening may be formed by etching part of the insulating layer 167 using the insulating layer 165 as a mask. Or insulating layer 1
After forming 67, an opening may be formed, and then an insulating layer 165 including the opening may be formed.

Next, a conductive film is formed over the insulating layer 165, and the first electrode layer 103 that is electrically connected to the source electrode or the drain electrode of the transistor 154 is formed by a photolithography method.

Next, an insulating layer 115 is formed to cover an end portion of the first electrode layer 103 and an opening formed in the insulating layer 165 (see FIG. 5C).

Subsequently, an EL layer 105 is formed over the first electrode layer 103. Here, the EL layer 105 that exhibits different emission colors in adjacent pixels is selectively formed by a vapor deposition method using a metal mask.

Note that an EL layer that emits white light in common as the EL layer 105 may be used, and a color filter that transmits different light may be provided above the light-emitting elements 120 of adjacent pixels to display full color. . In that case, a color filter is formed over the insulating layer 166 or formed over one surface of the protective layer 125 in advance. It is preferable to use a white light-emitting EL layer in common because a metal mask for separately painting pixels is not necessary.

  Subsequently, a second electrode layer 107 is formed over the EL layer 105.

Note that one of the first electrode layer 103 and the second electrode layer 107 is the light-emitting element 1.
20 functions as an anode, and the other functions as a cathode of the light emitting element 120. A material having a high work function is preferable for the electrode functioning as the anode, and a material having a low work function is preferable for the electrode functioning as the cathode.

  Through the above steps, the light emitting element 120 is formed.

  Finally, an insulating layer 166 that covers the second electrode layer 107 is formed (see FIG. 5D).

Through the above process, the transistor, the wiring, and the light-emitting element 120 can be formed over the supporting substrate 171.

Subsequently, separation (separation) is performed between the insulating layer 163 and the separation layer 173 (see FIG. 6A).
. Various methods can be used for the peeling method.

For example, the metal oxide film is formed at the interface between the separation layer 173 and the insulating layer 163 by heating the separation layer 173 and the insulating layer 163 during the formation process of the transistor. A groove reaching the peeling layer 173 is formed (not shown), and the metal oxide film becomes brittle due to the groove, and peeling occurs at the interface between the peeling layer 173 and the insulating layer 163.

The peeling method may be performed by applying a mechanical force (a process of peeling with a human hand or a jig, a process of separating while rotating a roller, or the like). Further, a liquid is dropped into the groove, and the liquid is allowed to permeate the interface between the separation layer 173 and the insulating layer 163, so that the separation layer 173 to the insulating layer 16
3 may be peeled off. Also, a fluorinated gas such as NF ₃ , BrF ₃ , ClF ₃ is introduced into the groove,
A method may be used in which the peeling layer 173 is removed by etching with a fluorinated gas, and the insulating layer 163 is peeled from the supporting substrate 171 having an insulating surface.

As another peeling method, when the peeling layer 173 is formed of tungsten, peeling can be performed while etching the peeling layer with a mixed solution of ammonia water and hydrogen peroxide water.

Further, a film containing nitrogen, oxygen, hydrogen, or the like (eg, an amorphous silicon film containing hydrogen, a hydrogen-containing alloy film, an oxygen-containing alloy film, or the like) is used as the separation layer 173, and the supporting substrate 171 has a light-transmitting property. In the case of using a substrate, the support substrate 171 and the release layer 173 are irradiated with laser light from the support substrate 171 to vaporize nitrogen, oxygen, and hydrogen contained in the release layer.
A method of peeling between the two can be used.

Next, the insulating layer 163 and the substrate 101 are bonded to each other using the adhesive layer 161 (see FIG. 6B). This process is also called transcription.

As the adhesive layer 161, various curable adhesives such as a photocurable adhesive such as an ultraviolet curable adhesive, a reactive curable adhesive, a thermosetting adhesive, or an anaerobic adhesive can be used. As materials for these adhesives, epoxy resins, acrylic resins, silicone resins, phenol resins, and the like can be used.

Through the above steps, the image display device 150 can be formed over the plastic substrate 101 (see FIG. 6C).

By applying the substrate 101 over which such an image display device 150 is formed to the method for manufacturing a light-emitting device illustrated in Embodiment Mode 1, an image display device including a curved light-emitting surface can be manufactured. In that case, the image display device 150 may be replaced with the light-emitting device 110 exemplified in the first embodiment.

This embodiment can be implemented in combination with any of the other embodiments and examples described in this specification as appropriate.

(Embodiment 3)
In this embodiment, examples of an electronic device or a lighting device to which the light-emitting device of one embodiment of the present invention is applied will be described with reference to drawings.

As an electronic apparatus to which a light-emitting device having a curved light-emitting surface is applied, for example, a television device (also referred to as a television or a television receiver), a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone Examples thereof include a large game machine such as a telephone (also referred to as a mobile phone or a mobile phone device), a portable game machine, a portable information terminal, a sound reproducing device, and a pachinko machine.

It is also possible to incorporate lighting and display devices along the inner or outer wall of a house or building, or along the curved surface of the interior or exterior of an automobile.

FIG. 7A illustrates an example of a mobile phone. A mobile phone 7400 includes a housing 7401.
In addition to the display portion 7402 incorporated in the mobile phone, an operation button 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like are provided. Note that the cellular phone 7400 is manufactured using the light-emitting device for the display portion 7402.

Information can be input to the cellular phone 7400 illustrated in FIG. 7A by touching the display portion 7402 with a finger or the like. In addition, any operation such as making a call or inputting characters can be performed by touching the display portion 7402 with a finger or the like.

Further, by operating the operation button 7403, the power can be turned on and off, and the type of image displayed on the display portion 7402 can be switched. For example, the mail creation screen can be switched to the main menu screen.

Here, the display portion 7402 incorporates the light-emitting device of one embodiment of the present invention. Therefore, a highly reliable mobile phone including a curved display portion can be provided.

FIG. 7B illustrates an example of a wristband display device. Portable display device 7100
Includes a housing 7101, a display portion 7102, operation buttons 7103, and a transmission / reception device 7104.

The portable display device 7100 can receive a video signal by the transmission / reception device 7104 and can display the received video on the display portion 7102. Also, the audio signal can be transmitted to another receiving device.

Further, the operation button 7103 can be used to perform power ON / OFF operation, switching of a video to be displayed, or adjusting an audio volume.

Here, the display portion 7102 incorporates the light-emitting device of one embodiment of the present invention. Therefore, the portable display device can be provided with a curved display portion and high reliability.

7C to 7E illustrate an example of a lighting device. Lighting devices 7200, 7210,
Each of the 7220 includes a base portion 7201 including an operation switch 7203 and a light emitting portion supported by the base portion 7201.

A lighting device 7200 illustrated in FIG. 7C includes a light-emitting portion 7202 having a wavy light-emitting surface. Therefore, the lighting device has high design.

A light emitting portion 7212 included in the lighting device 7210 illustrated in FIG. 7D has a structure in which two light emitting portions curved in a convex shape are arranged symmetrically. Accordingly, all directions can be illuminated with the lighting device 7210 as the center.

A lighting device 7220 illustrated in FIG. 7E includes a light-emitting portion 7222 that is curved in a concave shape. Therefore, since the light emitted from the light emitting unit 7222 is condensed on the front surface of the lighting device 7220, it is suitable for brightly illuminating a specific range.

Here, the display portion 7102 incorporates the light-emitting device of one embodiment of the present invention. Therefore, a highly reliable lighting device including a curved display portion can be provided.

Note that it is needless to say that the electronic device or the lighting device is not particularly limited as long as the light-emitting device of one embodiment of the present invention is included.

This embodiment can be implemented in combination with any of the other embodiments and examples described in this specification as appropriate.

In this example, light-emitting elements are manufactured over an insulating substrate and a conductive substrate, and the results of measuring temperature characteristics when the light-emitting elements emit light will be described.

[Preparation of sample]
First, an aluminum substrate having a thickness of 0.2 mm and a glass substrate having a thickness of 0.7 mm were prepared.

Subsequently, an epoxy resin layer having a thickness of about 6 μm was formed as a planarizing layer on each substrate by spin coating.

Subsequently, as the first electrode and wiring, a titanium film having a thickness of about 50 nm, an aluminum film having a thickness of about 200 nm, and a titanium film having a thickness of about 100 nm are stacked by sputtering using a shielding mask. did.

Subsequently, as an insulating layer covering the end of the first electrode and the like, the thickness is about 20 by screen printing.
A layer of μm epoxy resin was formed.

Thereafter, an EL layer exhibiting white light emission was formed by a vacuum evaporation method at a position overlapping with the first electrode. Subsequently, an alloy film of silver and magnesium having a thickness of about 30 nm was formed as a second electrode on the EL layer by vacuum deposition.

In this way, a length of about 56 mm and a width of about 42 m on the aluminum substrate and the glass substrate.
A light emitting device having m light emitting regions was formed. Here, a sample using an aluminum substrate is referred to as sample 1, and a sample using a glass substrate is referred to as sample 2. In this example, two samples 1 and two were prepared.

[Temperature characteristics evaluation]
Subsequently, the time dependency of the temperature on the light emitting surface when each sample was caused to emit light was evaluated.

In the evaluation, the sample was placed in contact with a stainless steel table and a thickness of 0.
A 7 mm glass plate was placed in contact, and a thermocouple was attached on the glass plate to measure the temperature. The temperature was measured at two points, a central portion of the light emitting surface and a region near the outer periphery.

FIGS. 8A and 8B are measurement results of temperature variation with respect to time from the start of light emission at each measurement point of each sample. FIG. 8A shows the measurement results at the center of the light emitting surface.
(B) shows measurement results in a region near the outer periphery of the light emitting surface. Hereinafter, the measurement results will be described.

First, in any sample, the heat generation temperature tended to be higher in the central portion than in the region near the outer periphery of the light emitting surface.

In Sample 1 using an aluminum substrate, focusing on the central portion, about 50 from the start of light emission.
Although the temperature rose sharply during the second, the temperature rise tended to be moderate after that. The temperature in the vicinity of the light emitting surface 300 seconds after the start of light emission was about 37 ° C. in the central portion and about 34 ° C. in the region near the outer periphery.

On the other hand, in sample 2 using a glass substrate, the temperature rise from the start of light emission was steeper than in sample 1 and the rate of temperature rise tended to be greater than that in sample 1 even after that. The temperature in the vicinity of the light emitting surface 300 seconds after the start of light emission was about 42 ° C. at the center and about 37 ° C. in the region near the outer periphery.

From the above results, it was confirmed that high heat dissipation can be realized by using a metal substrate as the substrate.

This example can be implemented in combination with any of the other embodiments and examples described in this specification as appropriate.

In this example, a light-emitting device manufactured by the method illustrated in Embodiment Mode 1 will be described.

First, like the sample 1 described in the first embodiment, a planarizing layer, a first layer is formed on an aluminum substrate.
The electrode layer, the insulating layer, the EL layer, and the second electrode layer are formed with a length of about 56 mm and a width of about 42 mm.
The light emitting element provided with the light emitting region was formed.

Subsequently, the aluminum substrate on which the light emitting element was formed was fixed to a support having a convex surface with a radius of curvature of 45 mm using a low viscosity adhesive.

  Subsequently, a photocurable epoxy resin was dropped on the aluminum substrate as a sealing material.

Subsequently, as a protective layer, a laminated body in which a glass layer having a thickness of about 50 μm, an adhesive layer having a thickness of about 20 μm, and a resin layer made of PET (Polyethylene terephthalate) having a thickness of about 38 μm are sequentially stacked, aluminum is used. In the region where the light emitting element is not provided on the substrate, the end portion of the protective layer was brought into close contact with the photo-curable epoxy resin. Subsequently, ultraviolet light having a wavelength of 365 nm was selectively irradiated from above the protective layer to the close contact portion to cure the epoxy resin, thereby bonding the protective layer and a part of the aluminum substrate.

Subsequently, using a roller-shaped member, while pressing this against the upper surface of the protective layer, rolling while pressing along the curved surface of the support starting from the above-mentioned contact point, the protective layer and the photocurable resin are in close contact with each other I let you.

Subsequently, the uncured region of the photo-curable resin was irradiated from above the protective layer to be cured by irradiating the ultraviolet ray, thereby completely bonding the aluminum substrate and the protective layer.

In this manner, a light emitting device having a curved light emitting portion on an aluminum substrate was manufactured.

  FIG. 9 shows a photographic image when the manufactured light-emitting device emits light.

In addition, the light emitting device manufactured in this example has been confirmed to emit favorable light even at a time exceeding 380 hours under normal temperature and humidity. In addition, about the sample which does not form a protective layer, the light emission defect was seen about 82 hours after preparation.

From the above results, it was confirmed that a light-emitting device including a curved light-emitting surface can be manufactured by the manufacturing method of one embodiment of the present invention without causing defects such as cracks and cracks. In addition, it was confirmed that the light-emitting device manufactured in this manner was a highly reliable light-emitting device with no sealing failure.

This example can be implemented in combination with any of the other embodiments and examples described in this specification as appropriate.

DESCRIPTION OF SYMBOLS 100 Light emitting device 101 Substrate 103 1st electrode layer 105 EL layer 107 2nd electrode layer 110 Light emitting device 111 Wiring 113 Planarization layer 115 Insulating layer 120 Light emitting element 121 Support body 122 Sealing material 123 Sealing layer 125 Protective layer 127 Optical 150 Image display device 151 Source wiring 152 Gate wiring 153 Transistor 154 Transistor 161 Adhesive layer 163 Insulating layer 165 Insulating layer 166 Insulating layer 167 Insulating layer 168 Insulating layer 171 Supporting substrate 173 Peeling layer 7100 Portable display device 7101 Housing 7102 Display unit 7103 Operation button 7104 Transmission / reception device 7200 Illumination device 7201 Base unit 7202 Light emission unit 7203 Operation switch 7210 Illumination device 7212 Light emission unit 7220 Illumination device 7222 Light emission unit 7400 Cellular phone 7401 Case 740 Display unit 7403 operation button 7404 an external connection port 7405 speaker 7406 microphone

Claims (1)

A substrate having a curved surface;
A light emitting device on the substrate;
A sealing layer having a region covering an upper surface and a side surface of the light emitting device;
A protective layer on the sealing layer,
The light emitting device includes a planarization layer and a light emitting element on the planarization layer,
The substrate has plasticity;
The light-emitting device, wherein the substrate does not have a flat upper surface.