JP2009151955A - Surface emitting light source and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface emitting light source with high light utilization efficiency. <P>SOLUTION: The surface emitting light source includes a cathode electrode 17, a luminous layer 11, and an anode electrode layer 15 formed in this order on a substrate 14. The luminous layer 11 is demarcated into a plurality of regions, and a cathode electrode layer 12 having a reflecting surface is formed on a surface opposed to the end face of the luminous layer 11. Thereby, light emitted from the end face of the luminous layer 11 is reflected by the cathode electrode layer 12 and led to an irradiation face. Thereby, light leaked from the end part of the surface emitting light source 1 is utilized as an illumination light to improve utilization efficiency of light. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a surface-emitting light source using a self-luminous light-emitting element such as an organic EL, and a manufacturing method thereof.

  There is an organic EL element as a light emitting element which has been attracting attention in recent years. As shown in FIG. 22, this element generally has a cathode electrode 103, a light emitting layer 104 and an anode electrode layer 105 made of a transparent electrode sequentially laminated on a substrate 102 such as a glass substrate, or vice versa. It is constructed by stacking in order. This type of organic EL element can emit light by applying a voltage between electrodes and injecting carriers into the organic EL layer, and can also be used as a surface-emitting light source.

  The following patent document discloses a structure in which a display surface is divided for each pixel using an organic EL as a display device.

Japanese Patent No. 3846819

  However, when an organic EL element is used as a surface-emitting light source, in general, most of the emitted light is repeatedly reflected inside the light-emitting layer and propagates to the end face of the peripheral portion, not the front, Since it is emitted to the outside from there, a loss of light amount occurs. The amount of light loss depends on the element structure, but generally it may reach 80%.

  In addition, it is known that when a defect exists on the light emitting surface, the defect grows in the surface direction of the light emitting surface over time due to the properties of the light emitting layer formed using an organic material. For this reason, a panel with even a few defects cannot be used. Therefore, if an attempt is made to increase the size with a single panel, the yield will be significantly reduced as long as the production is performed on a production line (of a quality level) equivalent to that of a normal small panel. This tendency becomes more pronounced as the panel size increases.

  In order to cope with this problem, a method of obtaining a surface emitting light source having a large area by connecting small panels having no defect is conceivable. However, in this method, since the number of joints and the number of panels increase with an increase in size, a reduction in productivity is inevitable. As another measure, a method of producing a large panel using a production line with a high quality level (low defect occurrence rate) is also conceivable, but in this case, there is a risk of increasing the cost required to construct the production line. is there.

  Further, in the surface emitting light source, as the size is increased, the temperature distribution and the resistance of the transparent electrode cannot be ignored.

  The present invention is intended to solve the above-described problems of the prior art, and its object is to provide a surface-emitting light source capable of improving the utilization rate of emitted light and improving the yield, a manufacturing method thereof, and In addition, an object of the present invention is to provide a surface-emitting light source capable of suppressing the occurrence of luminance unevenness and a method for manufacturing the same.

  A surface-emitting light source according to the present invention includes a light-emitting layer partitioned into a plurality of light-emitting regions and a reflective structure that is formed in a region between adjacent light-emitting regions and reflects light emitted from the light-emitting layer. It is.

  In the surface emitting light source of the present invention, since the light emitting layer is partitioned into a plurality of light emitting regions, defects generated in some light emitting regions do not affect other light emitting regions. In addition, the component of the light emitted from a certain light-emitting layer toward the adjacent light-emitting region is reflected by the reflecting structure, so that the light propagates one after another through the light-emitting layer and leaks from the outermost end surface to the outside. It is suppressed.

  In particular, when the reflecting structure has a reflecting surface extending in a direction intersecting the laminated surface of the light emitting layer, at least part of the light traveling from one light emitting region to the next light emitting region is the direction of the original light emitting region. Or in a direction intersecting the laminated surface of the light emitting layer (direction of irradiated surface).

  Furthermore, in particular, when the light emitting layer is sandwiched between the transparent electrode and the metal electrode from above and below, a top emission type surface emitting light source can be obtained. In this case, the light emitted from the end face of the light emitting layer in each light emitting region is reflected by the reflecting surface of the reflecting structure, and finally passes through the upper transparent electrode to irradiate the original irradiated surface. On the other hand, when the substrate is made of a transparent substrate and the light emitting layer is sandwiched between the metal electrode and the transparent electrode from above and below, a bottom emission surface emitting light source can be obtained. In this case, the light emitted from the end face of the light emitting layer in each light emitting region is reflected by the reflecting surface of the reflecting structure, and finally passes through the lower transparent electrode and the transparent substrate to irradiate the original irradiated surface.

  In addition, when an auxiliary electrode made of metal is additionally provided so as to be in contact with the transparent electrode, or a metal partition as a reflective structure is provided so as to be in contact with the transparent electrode, the wiring resistance of the transparent electrode is reduced. The As a result, even in the case of a surface emitting light source having a large area, the voltage drop is reduced, and the applied voltage between the electrodes is prevented from being different between the light emitting regions.

In addition, a light emitting layer is formed on the transparent electrode layer formed on the transparent substrate, and a transparent insulating layer is erected on the transparent electrode layer so as to surround the light emitting layer in contact with the outer peripheral end face of the light emitting layer in each light emitting region. When the metal electrode layer is formed so as to cover the surfaces of the light emitting layer and the transparent insulating layer, and a part of the metal electrode layer also serves as a reflection structure, a bottom emission type surface emitting light source can be obtained. . In this case, it is not necessary to separately provide a partition (metal partition) as a reflective structure.

The first surface-emitting light source manufacturing method according to the present invention includes a step of forming a metal electrode layer on a substrate, a plurality of spaced apart regions in the metal electrode layer to a predetermined depth, and a plurality of recesses. Forming a metal partition that separates the recesses of the metal, a step of forming a transparent insulating layer so as to cover from the upper surface of the metal partition to the side wall, and forming a light emitting layer on the bottom surface of each recess of the metal electrode layer And a step of forming a transparent electrode layer so as to cover from the light emitting layer to the transparent insulating layer.
In this method for manufacturing a surface light source, a plurality of recesses are formed in a metal electrode layer formed on a substrate, and a light emitting layer is formed on the bottom surface of each recess. A metal electrode layer portion between adjacent recesses becomes a metal partition. The transparent electrode layer is formed to be in contact with the light emitting layer and to extend on the metal partition via a transparent insulating layer. As a result, a top emission type surface emitting light source having a metal partition functioning as a reflecting structure is obtained.

The manufacturing method of the 2nd surface emitting light source of this invention selects the process of forming a transparent electrode layer on a transparent substrate, the process of forming a metal layer on a transparent electrode layer, and a metal layer until it reaches a transparent electrode layer Etching to form a plurality of regions where the transparent electrode layer is exposed and a metal partition separating the regions, and forming a transparent insulating layer so as to cover from the upper surface to the side wall of the metal partition A step, a step of forming a light emitting layer in the exposed region, and a step of forming a metal electrode layer so as to cover from the light emitting layer to the transparent insulating layer.
In this method for manufacturing a surface-emitting light source, a metal partition is selectively formed on a transparent electrode layer formed on a transparent substrate, and a transparent electrode in a region surrounded by the metal partition and a transparent insulating layer covering the metal partition A light emitting layer is formed on the layer. The metal electrode layer is formed so as to be in contact with the light emitting layer and to extend on the metal partition via a transparent insulating layer. As a result, a bottom emission type surface emitting light source having a metal partition functioning as a reflecting structure is obtained.

The third surface-emitting light source manufacturing method of the present invention includes a step of forming a transparent electrode layer on a transparent substrate, and a transparent surface on the transparent electrode layer so as to surround a plurality of regions separated from each other on the transparent electrode layer. Including a step of forming an insulating layer, a step of forming a light emitting layer in each of a plurality of regions on the transparent electrode layer, and a step of forming a metal electrode layer so as to cover from the light emitting layer to the transparent insulating layer. The insulating layer has a larger thickness than the light emitting layer and surrounds each of the plurality of regions, and the insulating layer has a smaller thickness than the light emitting layer and surrounds the outer periphery of the first portion. And a second portion forming an integral part.
In this method of manufacturing a surface light source, a transparent insulating layer is selectively formed on a transparent electrode layer formed on a transparent substrate, and a light emitting layer is formed on the transparent electrode layer in a region surrounded by the transparent insulating layer. Is formed. The metal electrode layer is formed to be in contact with the light emitting layer in the light emitting region and to extend on the transparent insulating layer between the light emitting regions. The transparent insulating layer is formed so as to include an inner portion (first portion) surrounding the light emitting layer with a thickness greater than that of the light emitting layer, and an outer portion (second portion) thinner than the light emitting layer. As a result, a bottom emission type surface emitting light source is obtained in which the metal electrode layer as the upper electrode also serves as a reflection structure.

The fourth surface emitting light source manufacturing method of the present invention includes a step of forming a metal electrode layer on a substrate, a step of forming an opaque insulating layer on the metal electrode layer, and a metal layer on the opaque insulating layer. A step of selectively etching the metal layer until it reaches the opaque insulating layer to form a plurality of regions where the opaque insulating layer is exposed and a metal partition separating the regions; and Removing the exposed opaque insulating layer to expose the metal electrode layer; forming a transparent insulating layer so as to cover the side wall surface of the metal partition; and the metal electrode layer in the region where the opaque insulating layer is removed The method includes a step of forming a light emitting layer thereon and a step of forming a transparent electrode layer so as to cover the metal partition through the transparent insulating layer from the light emitting layer.
In this surface emitting light source manufacturing method, a metal layer is formed on a metal electrode layer formed on a transparent substrate via an insulating layer, and the metal layer is selectively etched using the insulating layer as an etching stopper. . The remaining part of the metal layer after etching becomes a metal partition. Thereafter, the exposed insulating layer is removed to expose the metal electrode layer, and the side wall surface of the metal partition wall is covered with the transparent insulating layer, and then a light emitting layer is formed on the exposed metal electrode layer. The transparent electrode layer is formed to be in contact with the light emitting layer in the light emitting region and to extend on the transparent insulating layer and the metal partition between the light emitting regions. As a result, a top emission type surface emitting light source having a metal partition functioning as a reflecting structure is obtained. In this case, since the metal partition also functions as a metal wiring that contacts the transparent electrode layer, the wiring resistance of the transparent electrode is reduced.

  According to the surface emitting light source of the present invention, since the light emitting layer is partitioned into a plurality of light emitting regions, defects generated in some of the light emitting regions do not expand to other light emitting regions. In addition, since the reflection structure is provided in the region between the light emitting regions adjacent to each other, the light use efficiency of the emitted light can be increased.

  In particular, when an auxiliary electrode made of metal is additionally provided so as to be in contact with the transparent electrode, or a metal partition as a reflective structure is provided so as to be in contact with the transparent electrode, the wiring resistance of the transparent electrode is reduced. Therefore, even if it is a surface emitting light source with a large area, the light emission luminance unevenness can be reduced.

  Further, when the lens layer is formed on the light emitting surface side (transparent electrode side), the light emitted from the light emitting surface can be efficiently guided to the irradiated surface, and the light utilization efficiency can be further increased.

  In addition, a transparent insulating layer is erected on the transparent electrode layer so as to surround the light emitting layer in each light emitting region, and the metal electrode layer is formed so as to cover the surfaces of the light emitting layer and the transparent insulating layer. When the portion also serves as a reflection structure, it is not necessary to separately provide a partition (metal partition) as the reflection structure, so that the process is simplified.

According to the first to fourth surface emitting light source manufacturing methods of the present invention, a light emitting layer partitioned into a plurality of light emitting regions, and a reflective structure (metal partition wall or metal electrode layer) surrounding the light emitting layers of each light emitting region, Is obtained. For this reason, it is possible to increase the manufacturing yield by suppressing the defects generated in the light emitting layer in a part of the light emitting region from spreading to the entire surface emitting light source, and the generated light propagates inside the light emitting layer to the outside. It is possible to increase the light use efficiency by suppressing the loss.

  In particular, according to the fourth method for manufacturing a surface emitting light source, a metal layer is formed on a metal electrode layer formed on a transparent substrate via an insulating layer, and the metal layer is selectively used as an etching stopper. Etching was performed to form a metal barrier in the non-etched region, and then the etching stopper (insulating layer) was removed to expose the metal electrode layer, so that the thickness of the metal electrode layer and the height of the metal barrier Can be controlled with high accuracy. In addition, the metal partition wall also functions as a metal wiring that comes into contact with a transparent electrode layer that will be formed later, so that the wiring resistance of the transparent electrode layer is reduced, and uneven emission luminance in the entire surface emitting light source can be suppressed.

  Hereinafter, the best mode for carrying out the present invention (hereinafter simply referred to as an embodiment) will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 shows a planar structure of a surface-emitting light source according to the first embodiment of the present invention, and FIG. 2 shows an AA arrow of one light-emitting cell (light-emitting region) in this surface-emitting light source. The cross-sectional structure (represents a surface emission light source 1) is configured as a top emission type (top emission type) surface emission light source, and has a plurality of light emitting cells as shown in FIG. 2, the surface-emitting light source 1 has a structure in which a cathode electrode layer 12, a light-emitting layer 11, and an anode electrode layer 15 are sequentially laminated on a substrate 14. A central portion of the cathode electrode layer 12 ( In the light emitting region, a concave portion is formed, and a light emitting layer 11 is formed at the bottom of the concave portion.A portion of the cathode electrode layer 12 surrounding the light emitting layer 11 (region between the adjacent light emitting region) is The partition 16 is formed as a reflective structure. A transparent insulating layer 13 is formed between the light emitting layer 11 and the partition 16. The transparent insulating layer 13 extends to the partition 16. On the upper surfaces of the light emitting layer 11 and the transparent insulating layer 13, the transparent insulating layer 13 is formed. The anode electrode layer 15 is formed, that is, the light emitting layer 11 is partitioned into a plurality of light emitting cells by the partition walls 16 and the transparent insulating layer 13.

  The substrate 14 is made of, for example, a transparent (light transmissive) material such as glass, but is not limited thereto. For example, an opaque substrate such as a resin substrate or a ceramic substrate can be used.

  The cathode electrode layer 12 is one electrode for applying a voltage to the light emitting layer 11 and extends in common to all the light emitting cells. The cathode electrode layer 12 can be made of a conductive material having a high light reflectivity, for example, a metal material such as aluminum (Al), silver (Ag), or titanium (Ti). The recessed area of the cathode electrode layer 12 has a film thickness of, for example, about 1 μm.

  The light emitting layer 11 emits light according to a voltage applied between the anode electrode layer 15 and the cathode electrode layer 12 from the outside, and can be configured using, for example, an organic EL (Organic Electro-Luminescence) material. It is. However, it is not limited to this, In addition, for example, an inorganic EL material can be used. Moreover, although the shape of the light emitting layer 11 is circular in FIG. 1, it is not limited to this, For example, according to the shape of the partition 16, you may make it a triangle, a square, a hexagon, etc. In addition, it is preferable that the light emitting layer 11 has a film thickness of about 200 nm, for example. Further, the distance d between the centers of the light emitting cells adjacent to each other can be, for example, about 1 mm, but is not limited thereto.

  The anode electrode layer 15 is the other electrode for applying a voltage to the light emitting layer 11 and is made of a transparent conductive material such as indium tin oxide (ITO). The anode electrode layer 15 is disposed on the entire light emitting surface so as to cover the light emitting layer 11 and the insulating layer 13 of all the light emitting cells. The anode electrode layer 15 preferably has a sufficient film thickness so that the wiring resistance does not increase in order to ensure that a uniform voltage is simultaneously applied to the entire light emitting region.

  The partition wall 16 forms a part of the anode electrode layer 15, partitions the light emitting layer 11 into individual light emitting cells, and reflects the light generated in the light emitting layer 11 to guide it in a predetermined direction. The height of the partition wall 16 is preferably higher (thicker) than the height (film thickness) of the light emitting layer 11, and is formed to have a film thickness of about 1 μm, for example. The partition wall 16 is formed in a regular hexagonal shape as shown in FIG. Thereby, the light emitting layer 11 formed in a circle can be accommodated at a relatively high density (high efficiency). The wall thickness l of the partition wall 16 is, for example, about 3 μm.

The insulating layer 13 ensures an insulating state between the cathode electrode layer 12 and the anode electrode layer 15. The insulating layer 13 can be made of, for example, an insulating material such as silicon dioxide (SiO ₂ ) or silicon nitride (SiN), or a coating type photosensitive insulating material such as photosensitive SOG (Spin-On-Glass).

  Next, the operation of the surface emitting light source 1 will be described with reference to FIG.

Most of the light emitted by the light emitting layer 11 (front direction component t ₁ ) passes through the anode electrode layer 15 and is emitted to the irradiated surface side. On the other hand, the other part (end surface direction component t ₂ ) is emitted from the end surface of the light emitting layer 11, reflected by the side surface (reflecting surface 18 A) of the partition wall 16, and then transmitted through the anode electrode layer 15 to pass through the irradiated surface. Irradiate. That is, the end face direction component t ₂ of the emitted light propagates up to the outermost peripheral portion of the surface-emitting light source 1, it is prevented from leaking from the end. Thereby, the light use efficiency can be increased and the light emission luminance can be improved.

In addition, since the light emitting layer is divided into a plurality of light emitting regions and is separated for each light emitting region, even if a defect occurs in the light emitting layer of any one of the light emitting cells, that is the case with other light emitting cells. And the growth of defects in the surface direction of the surface-emitting light source 1 is suppressed. Therefore, even when using a production line of a normal quality level for producing small organic EL elements,
The production yield of a large surface emitting light source can be increased.

  Hereinafter, modifications of the present embodiment will be described.

(Modification 1-1)
In the present modification, as shown in FIG. 4, the partition 16A forming a part of the cathode electrode layer 12 has a gradient. Other configurations are the same as those in FIG. Since the partition wall 16A has a gradient, the light reflected by the partition wall 16A easily travels toward the irradiated surface, and the light use efficiency is increased. The “irradiated surface” refers to a surface to which the surface emitting light source 1 emits light, and is a surface facing the anode electrode layer 15 in the example of FIG.

(Modification 1-2)
As shown in FIG. 5A, the surface-emitting light source 1A of this modification includes an auxiliary electrode 19 made of a metal such as aluminum or silver between the transparent insulating layer 13 and the anode electrode layer 15A. Other configurations are the same as those in FIG. Since the auxiliary electrode 19 is a low-resistance metal wiring electrically connected to the anode electrode layer 15, the auxiliary electrode 19 acts to reduce the wiring resistance of the anode electrode layer 15A. For this reason, the fall of the voltage applied between a cathode electrode layer and an anode electrode layer can be suppressed, the loss of the voltage applied to the center part of the surface emitting light source 1 is suppressed, and light emission in the light emission surface is carried out. The brightness can be made uniform.
As shown in FIG. 5B, the same effect can be obtained by forming the auxiliary electrode 19A on the upper surface of the anode electrode layer 15 excluding the upper portion of the light emitting layer 11 (light emitting portion).

(Modification 1-3)
In this modification, a mechanism for controlling the emission direction is added to the surface-emitting light source 1. As illustrated in FIG. 6A, the surface light source 1 </ b> B includes a microlens 20 that controls the emission direction on the upper surface of the anode electrode layer 15. By providing the microlens 20 on the upper portion (light extraction portion) of the light emitting layer 11, the emitted light can be condensed on the irradiation surface, and the light utilization efficiency can be improved.

  Further, the microlens 20 of the present modification and the auxiliary electrode 19 of the modification 2 may be combined. As shown in FIG. 6B, the auxiliary electrode 19 is formed between the transparent insulating layer 13 and the anode electrode layer 15A, and the microlens 20 is formed on the upper surface of the anode electrode layer 15A. In this case, it is possible to increase the light use efficiency of the surface emitting light source and to ensure the uniformity of the light emission luminance over the entire light emitting surface.

(Modification 1-4)
In this modification, the substrate itself also serves as a cathode electrode and a reflection structure. As illustrated in FIG. 7, the surface-emitting light source 1 </ b> C of this modification includes a substrate 24, a light emitting layer 11, a transparent insulating layer 13, and an anode electrode layer 15. The substrate 24 also serves as the cathode electrode 17 and the partition wall 16, and is formed of the same material as the cathode electrode of the above embodiment (FIG. 2). Thus, by making the substrate 24 also serve as the cathode electrode 17 and the partition wall 16, the film forming process can be reduced and simplified.

  Next, a method for manufacturing the surface-emitting light source 1 shown in FIG. 2 will be described with reference to FIG.

  First, as shown in FIG. 8A, an Al layer having a thickness of about 1 μm serving as a cathode electrode is formed on the substrate 14 by, for example, PVD (Physical Vapor Deposition). Subsequently, the recess 28 and the partition 16 are formed by removing a part of the Al layer (a part necessary for forming the light emitting layer 11) by an etching technique such as photolithography or a fine processing technique such as laser processing. . The height of the partition 16 is made larger than the film thickness of the light emitting layer 13 to be described later. For the formation of the Al layer, a CVD (Chemical Vapor Deposition) method can be used in addition to the PVD, although the manufacturing method is different.

Next, as shown in FIG. 8B, an SiO ₂ layer (transparent insulating layer 13) having a thickness of about 150 nm is formed on the partition wall 16 by, for example, a CVD method or a PVD method. Subsequently, the surface of the concave portion 28 is exposed by removing a part of the transparent insulating layer 13 by an etching technique such as a photolithography method or a fine processing technique such as laser processing.

  Next, as shown in FIG. 8C, the light emitting layer 11 having a thickness of about 200 nm is formed on the bottom surface of the recess of the cathode electrode layer 12 (region surrounded by the transparent insulating layer 13) by, for example, ink jet or laser transfer. Form.

  Next, as shown in FIG. 8D, the anode electrode layer 15 is formed on the top surfaces (entire light emitting surfaces) of the light emitting layer 11 and the transparent insulating layer 13.

  The surface emitting light source 1 can be formed by the above steps. Although not described, a plurality of light emitting areas are formed in the surface emitting light source 1 by the above method. At this time, the distance d between adjacent light emitting regions is, for example, about 1 mm.

  In the method for manufacturing the surface-emitting light source according to the present embodiment, the light-emitting surface of the surface-emitting light source 1 is formed by dividing it into a plurality of light-emitting regions, so that a defect occurs in a part of the surface-emitting light source 1. Even if it is a case, the growth in the surface direction of the defect can be suppressed, and the manufacturing yield can be increased.

  In particular, when the area of the surface emitting light source is increased, it is not necessary to produce a plurality of small light source panels in consideration of the occurrence of defects and to connect them, thereby increasing productivity.

  Further, since the cathode electrode 12 is formed on the lower surface of the light emitting layer 11 and the anode electrode layer 15 is formed on the upper surface thereof, a top emission type surface emitting light source can be formed.

[Second Embodiment]
Then, the structure of the surface emitting light source of the 2nd Embodiment of this invention is demonstrated. The surface emitting light source of this embodiment is configured as a bottom emission type (bottom emission type) surface emitting light source, and an anode electrode and a cathode electrode are provided on opposite sides, and a partition wall and a cathode electrode are provided. It is a separate body. The same parts as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  The planar configuration of the surface emitting light source according to the present embodiment is the same as that shown in FIG. FIG. 9 illustrates a cross-sectional configuration of the surface-emitting light source according to the present embodiment taken along the line AA. The surface emitting light source 2 includes a substrate 34, an anode electrode layer 15B, a partition wall 16B, a light emitting layer 11, a transparent insulating layer 13, and a cathode electrode 17A. On the substrate 34, an anode electrode layer 15B is formed. On the anode electrode layer 15B, the light emitting layer 11 and the partition 16B are formed in a state of being separated from each other. A transparent insulating layer 13 is formed on the side surface and the upper surface of the partition wall 16B. A cathode electrode 17 </ b> A is formed on the light emitting layer 11 and the transparent insulating layer 13. The light emitting layer 11 and the partition wall 16B, and the anode electrode layer 15B and the cathode electrode 17A are separated from each other by the transparent insulating layer 13.

  The partition wall 16B is the same quality as the partition wall 16 described above. The film thickness is larger than the film thickness of the light emitting layer 11 and is, for example, about 1 μm. The light emitting layer 11 is provided so as to surround the end surface of the light emitting layer 11 in order to guide the side direction component of the light emitted by the light emitting layer 11 to the irradiation surface (substrate 34 side). In addition, since it is bonded to the anode electrode layer 15B, it also has a function as an auxiliary wiring of the anode electrode layer 15B.

  The anode electrode layer 15B and the cathode electrode 17A form a pair of electrodes for applying a voltage to the light emitting layer 14. The anode electrode layer 15B is a transparent electrode similar to the anode electrode layer 15 described above. The cathode electrode 17A is a metal electrode similar to the cathode electrode 17 described above.

Then, the effect | action of the surface emitting light source 2 is demonstrated with reference to FIG.

Most of the light emitted by the light emitting layer 11 (front direction component t ₃ ) passes through the anode electrode layer 15B and the substrate 34 and is emitted to the irradiation surface side. On the other hand, the other part (end surface direction component t ₄ ) is emitted from the end surface of the light emitting layer 11, and is a plurality of reflection surfaces, for example, the reflection surface 18B, the reflection surface 18C, the reflection surface 18D, or any one of them. After repeating this reflection, the irradiated surface is irradiated through the anode electrode layer 15B and the substrate 34.

  Hereinafter, modifications of the present embodiment will be described.

(Modification 2)
In this modification, the lower surface of the substrate is formed in a lens shape. As shown in FIG. 11, the lower surface of the substrate 34A is formed in a mechanism for controlling the light emission direction, for example, a lens shape. Thereby, the light emission direction can be controlled, and the light utilization efficiency can be increased.

  As described above, in the surface emitting light source according to the present embodiment, the partition wall 16B is provided so as to cover the end surface of the light emitting layer 11, so that the end surface direction component of the emitted light is from the end of the surface emitting light source 2. Leakage can be avoided, light utilization efficiency can be increased, and light emission luminance can be improved.

  In particular, by bonding the partition wall 16B and the anode electrode layer 15, the wiring resistance of the anode electrode layer 15B can be reduced, and uneven brightness in the light emitting surface can be suppressed.

  Further, when the shape of the lower surface of the substrate is formed in a lens shape, the light emission direction can be controlled, and the light utilization efficiency can be further improved.

  Next, with reference to FIG. 12, the manufacturing method of the surface emitting light source 2 shown in FIG. 9 is demonstrated.

  First, as shown in FIG. 12A, an anode electrode layer 15B having a film thickness of, for example, about 150 nm is formed on a substrate. Subsequently, for example, an Al layer 21 having a thickness of about 1 μm is formed. Here, the film thickness of the Al layer 21 is made thicker than the film thickness of the light emitting layer 11 described later.

  Next, as shown in FIG. 12B, a part of the Al layer 21 (a part necessary for forming the light emitting layer 11) is selectively removed to form the partition 16B. Subsequently, the transparent insulating layer 13 having a thickness of about 150 nm is formed on the anode electrode layer 15B including the partition wall 16B. Thereafter, a part of the transparent insulating layer 13 (a part necessary for forming the light emitting layer 11) is removed to expose a part of the anode electrode layer 15B.

  Next, as shown in FIG. 12C, the light emitting layer 11 having a thickness of about 200 nm is formed on the exposed upper surface of the anode electrode layer 15B by, for example, ink jet or laser transfer.

  Next, as illustrated in FIG. 12D, the cathode electrode 16 </ b> A is formed on the upper surfaces (the entire light emitting surface) of the light emitting layer 11 and the transparent insulating layer 13.

  Through the above steps, the surface emitting light source 2 can be formed. Similar to the surface-emitting light source 1, a plurality of light-emitting regions are formed simultaneously.

  In the method for manufacturing the surface light source according to the present embodiment, the partition wall 16B is formed so that the light emitting surface is divided into a plurality of light emitting regions, so that the manufacturing method of the first embodiment is performed. Similarly to the above, the production yield can be increased, and the productivity can be increased when the area of the surface emitting light source is increased.

  In particular, since the cathode electrode 17 is formed on the lower surface of the light emitting layer 11 and the anode electrode layer 15 is formed on the upper surface thereof, a bottom emission type surface emitting light source can be formed.

[Third Embodiment]
Then, the structure of the surface emitting light source of the 3rd Embodiment of this invention is demonstrated. The surface-emitting light source according to the present embodiment is configured as a bottom emission type surface-emitting light source, and uses a cathode electrode to cover the side surface of the light-emitting layer without using a partition wall. Parts that are the same as those in the first and second embodiments described above are denoted by the same reference numerals and description thereof is omitted.

  The planar configuration of the surface emitting light source according to the present embodiment is the same as that shown in FIG. FIG. 13 illustrates a cross-sectional configuration of the surface-emitting light source according to the present embodiment taken along the line AA. The surface light source 3 includes a substrate 34, an anode electrode layer 15B, a light emitting layer 11, a transparent insulating layer 13B, and a cathode electrode 27. On the substrate 34, an anode electrode layer 15B is formed. A light emitting layer 11 and a transparent insulating layer 13B are formed on the anode electrode layer 15B, and a cathode electrode 27 is formed on the light emitting layer 11 and the transparent insulating layer 13B.

The transparent insulating layer 13B insulates between the anode electrode layer 15B and the cathode electrode 27, and is an insulating material such as SiO ₂ , for example. The transparent insulating layer 13B includes a first portion 13C standing on the anode electrode layer 15B so as to face the outer peripheral end surface of the light emitting layer 11, and a second portion provided on the outer peripheral surface of the first portion. It is out. The film thickness of the first part is larger than the film thickness of the light emitting layer 11, for example, about 600 nm. The film thickness of the second part is thinner than the film thickness of the light emitting layer 11, for example, about 150 nm.

  The cathode electrode 27 is an electrode for pairing with the anode electrode layer 15B and applying a voltage to the light emitting layer. The cathode electrode 27 includes an upper surface portion 27 </ b> A provided on the upper surface of the light emitting layer 11 and an end surface portion 27 </ b> B provided so as to face the end surface of the light emitting layer 11. The end face portion 27B also has a function as a partition that partitions the light emitting layer for each light emitting region.

  Then, the effect | action of the surface emitting light source 3 is demonstrated with reference to FIG.

Most of the light emitted by the light emitting layer 11 (front direction component t ₅ ) passes through the anode electrode layer 15B and the substrate 34 and is emitted to the irradiation surface side. On the other hand, the other part (end surface direction component t ₆ ) is emitted from the end surface of the light emitting layer 11 and is repeatedly reflected on a plurality of reflecting surfaces, for example, the reflecting surface 18E, the reflecting surface 18F, and the reflecting surface 18G. The irradiated surface is irradiated through the anode electrode layer 15B and the substrate 34.

  As described above, in the surface emitting light source according to the present embodiment, a part of the cathode electrode 27 (end surface portion 27B) is formed so as to face the end surface of the light emitting layer 11, so It is possible to avoid leakage of a part of the emitted light from the end portion, increase the light use efficiency, and improve the light emission luminance.

  Next, with reference to FIG. 15, the manufacturing method of the surface emitting light source 3 shown in FIG. 13 is demonstrated.

First, as shown in FIG. 15A, an anode electrode layer 15B having a film thickness of, for example, about 150 nm is formed on the substrate.

Next, as shown in FIG. 15B, a transparent insulating layer 13B is formed. Specifically, a SiO ₂ layer having a thickness of about 600 nm is formed. Subsequently, the region 22A where the light emitting layer 11 is formed in the SiO ₂ layer is selectively removed to expose the anode electrode layer 15B. Further, a part of the remaining SiO ₂ layer (region where the end face portion 27B of the cathode electrode 27 is formed) 22B is selectively removed. Through the above steps, the transparent insulating layer 13B having the first portion 13C of the transparent insulating layer having a thickness of about 600 nm and the second portion 13D of the transparent insulating layer having a thickness of about 150 nm is formed. Incidentally, the film thickness of the SiO ₂ layer is present on top of the anode electrode layer 15B is reduced, followed by a method of removing the SiO ₂ layer is present together with a part 22B of the SiO ₂ layer on top of the anode electrode layer 15B, The transparent insulating layer 13B can also be formed.

  Next, as shown in FIG. 15C, the light emitting layer 11 having a thickness of about 200 nm is formed on the exposed upper surface of the anode electrode layer 15B by, for example, ink jet or laser transfer.

  Next, as shown in FIG. 15D, the cathode electrode 27 is formed on the upper surfaces (entire light emitting surfaces) of the light emitting layer 11 and the transparent insulating layer 13B by, for example, the PVD method.

  Through the above steps, the surface emitting light source 3 can be formed. Similar to the surface emitting light sources 1 and 2, a plurality of light emitting regions are formed simultaneously.

  In the method for manufacturing the surface emitting light source according to the present embodiment, a part of the transparent insulating layer 13 </ b> B (second portion 13 </ b> D) is formed thinner than the light emitting layer 11, and one of the cathode electrodes 27 is formed. Since the portion (end surface portion 27B) is formed so as to face the end surface of the light emitting layer 11, the end surface component of the emitted light can be guided to the irradiation surface, the light use efficiency can be improved, and the partition wall can be separately provided. The number of manufacturing steps can be reduced.

[Fourth Embodiment]
Then, the structure of the surface emitting light source of the 4th Embodiment of this invention is demonstrated. The surface-emitting light source of the present embodiment is configured as a top emission type surface-emitting light source, and a metal partition that also functions as an auxiliary electrode is disposed on the lower surface of the anode electrode layer, and the metal partition and the cathode electrode An interelectrode insulating film that also functions as an etching stopper layer is provided between the two layers. The same parts as those in the first and third embodiments described above are denoted by the same reference numerals and description thereof is omitted.

  The planar configuration of the surface emitting light source according to the present embodiment is the same as that shown in FIG. FIG. 16 illustrates a cross-sectional configuration of the surface-emitting light source according to the present embodiment taken along the line AA. The surface emitting light source 4 includes a substrate 14, a cathode electrode 17, an opaque insulating layer 23, a transparent insulating layer 13E, a light emitting layer 11, a partition wall 16C, and an anode electrode layer 15. A cathode electrode 17 is formed on the substrate 12. A light emitting layer 11 is formed on a part of the upper surface of the cathode electrode 17. A transparent insulating layer 13E is formed on the upper surface of the cathode electrode 17 and in contact with the outer peripheral end face of the light emitting layer 11. An opaque insulating layer 23 is formed on the upper surface of the cathode electrode 17 and in contact with the outer peripheral end surface of the transparent insulating layer 13E. In addition, a partition wall 16C is formed on the upper surface of the opaque insulating layer 23 so as to be in contact with the outer peripheral end surface of the transparent insulating layer 13E.

The opaque insulating layer 23 is for electrically insulating the cathode electrode 17 and the partition 16C, and also has a function of controlling the thickness of the partition 16C during the manufacture of the surface emitting light source. The opaque insulating layer 23 is, for example, AlN or Al ₂ O ₃ . Or it may be SiO ₂ or SiN. The opaque insulating layer 23 is thinner than the light emitting layer 11 and is, for example, about 100 nm.

  The transparent insulating layer 13E insulates between the anode electrode layer 15B and the cathode electrode 27, and is the same quality as the transparent insulating layer 13.

  The partition wall 16 </ b> C is the same quality as the partition wall 16. The film thickness is larger than the film thickness of the light emitting layer 11, for example, about 600 nm. The light emitting layer 11 is provided so as to surround the end surface of the light emitting layer 11 in order to guide the side direction component of the light emitted by the light emitting layer 11 to the irradiation surface (substrate 14 side). Further, the film thickness of the partition wall 16C and the transparent insulating layer 13E is made larger than the film thickness of the light emitting layer 11. The partition wall 16 </ b> C also has a function as an auxiliary wiring of the anode electrode layer 15 by being in contact with the anode electrode layer 15.

  Next, the operation of the surface emitting light source 4 will be described with reference to FIG.

Most of the light emitted from the light emitting layer 11 (front direction component t ₇ ) passes through the anode electrode layer 15 and is emitted to the irradiation surface side. On the other hand, the other part (end surface direction component t ₈ ) is emitted from the end surface of the light emitting layer 11, and is reflected by the reflection surface 18 H, for example, and then passes through the anode electrode layer 15 to irradiate the irradiation surface.

  As described above, in the surface emitting light source according to the present embodiment, the side wall 16C is formed so as to face the end surface of the light emitting layer 11, so that a part of the emitted light is emitted from the end of the light emitting surface. Leakage can be avoided, light utilization efficiency can be increased, and light emission luminance can be improved.

  In particular, since the anode electrode layer 15 and the partition wall 16C are provided in contact with each other, the wiring resistance of the anode electrode can be reduced, and the light emission luminance in the light emitting surface can be made uniform.

  Next, a method for manufacturing the surface-emitting light source 4 shown in FIG. 16 will be described with reference to FIGS. Will be described.

  First, as shown in FIG. 18A, the cathode electrode 17 having a thickness of about 600 nm is formed on the substrate 14 by, for example, the PVD method. Subsequently, the opaque insulating layer 23 having a thickness of about 100 nm is formed by, for example, the PVD method or the CVD method. Thereafter, for example, a metal auxiliary electrode layer 25 having a thickness of about 1 μm is formed by a PVD method.

  Next, as shown in FIG. 18B, part of the auxiliary electrode layer 25 is removed. Specifically, a resist layer 26 is formed on the upper surface of the region where the auxiliary electrode layer 25 is to remain, and then the exposed auxiliary electrode layer 25 is selectively etched under the condition of etching only the auxiliary electrode layer to form the partition 16C. And the opaque insulating layer 23 is exposed.

  Next, as shown in FIG. 18C, part of the opaque insulating layer 23 is removed. Specifically, the exposed opaque insulating layer 23 is selectively etched under the condition of etching only the opaque insulating layer 23 to expose the cathode electrode 17. At this time, the resist layer 26 is removed as post-processing. Note that these etching processes (FIGS. 18B and 18C) may be performed in the same process.

Next, as shown in FIG. 19A, a transparent insulating layer 13E is formed. Specifically, an SiO ₂ film is formed on the partition wall 16C and the cathode electrode 17 by, for example, a CVD method, and subsequently etched from above. Thereby, only the side surfaces of the partition walls 16C and the opaque insulating layer 23 remain, and the transparent insulating layer 13E is formed.

  Next, as shown in FIG. 19B, the light emitting layer 11 of about 1 μm is formed on the exposed upper surface of the cathode electrode 17 by, for example, ink jet or laser transfer.

  Next, as shown in FIG. 19C, the anode electrode layer 15 is formed on the light emitting layer 11, the transparent insulating layer 13E, and the upper surface (entire light emitting surface) of the partition 16C.

  The surface emitting light source 4 can be formed by the above process. Similar to the surface emitting light sources 1 to 3, a plurality of light emitting regions are formed simultaneously.

  In the method for manufacturing the surface-emitting light source according to the present embodiment, the light-emitting surface is divided into a plurality of light-emitting regions as in the method for manufacturing the surface-emitting light source 1. Even when a defect is partially generated, growth in the surface direction of the defect can be suppressed, and the manufacturing yield can be increased.

  In particular, since the opaque insulating layer 23 is formed between the cathode electrode 17 and the partition 16C, and the partition 16C and the opaque insulating layer 23 are etched by etching methods having different properties, the partition 16C and the cathode 17 Can be controlled with high accuracy.

  Although the present invention has been described with reference to the embodiment, the present invention is not limited to this embodiment, and various modifications can be made. For example, the shape of the light emitting region may be changed. For example, as shown in FIG. 20, a quadrangular shape may be used. In this case, the light emitting region can be easily formed. Moreover, as shown in FIG. 21, it may be a triangle.

It is a top view of the surface emitting light source which concerns on the 1st Embodiment of this invention. It is sectional drawing showing the principal part sectional structure of the surface emitting light source shown in FIG. It is a figure showing the emitted optical path of the surface emitting light source shown in FIG. It is a figure showing the modification which concerns on 1st Embodiment. It is a figure showing the other modification which concerns on 1st Embodiment. It is a figure showing the other modification which concerns on 1st Embodiment. It is a figure showing the other modification which concerns on 1st Embodiment. It is a figure showing the other modification which concerns on 1st Embodiment. It is a figure showing the other modification which concerns on 1st Embodiment. It is sectional drawing showing the manufacturing method of the surface emitting light source shown in FIG. It is sectional drawing showing the principal part sectional structure of the surface emitting light source which concerns on the 2nd Embodiment of this invention. It is a figure showing the emitted optical path of the surface emitting light source shown in FIG. It is a figure showing the modification which concerns on 2nd Embodiment. It is sectional drawing showing the manufacturing method of the surface emitting light source shown in FIG. It is sectional drawing showing the principal part sectional structure of the surface emitting light source which concerns on the 3rd Embodiment of this invention. It is a figure showing the emitted optical path of the surface emitting light source shown in FIG. It is sectional drawing showing the manufacturing method of the surface emitting light source shown in FIG. It is sectional drawing showing the principal part sectional structure of the surface emitting light source which concerns on the 4th Embodiment of this invention. It is a figure showing the emitted optical path of the surface emitting light source shown in FIG. It is sectional drawing showing the manufacturing method of the surface emitting light source shown in FIG. It is a figure following FIG. It is a figure showing the modification of the surface emitting light source which concerns on this invention. It is a figure showing the other modification of the surface emitting light source which concerns on this invention. It is sectional drawing showing the principal part sectional structure of the conventional surface emitting light source.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C, 2, 3, 4 ... Surface emitting light source, 11 ... Light emitting layer, 12 ... Cathode electrode layer, 13, 13B, 13E ... Transparent insulating layer, 13C ... 1st site | part of a transparent insulating layer, 13D ... 2nd part of transparent insulating layer, 14, 24, 34 ... substrate, 15, 15A, 15B ... anode electrode layer, 16, 16A, 16B, 16C ... partition wall, 17, 17A, 27 ... cathode electrode, 19, 19A ... Auxiliary electrode, 20... Micro lens, 23... Opaque insulating layer, 27 A.

Claims (24)

A light-emitting layer partitioned into a plurality of light-emitting regions;
A surface-emitting light source comprising: a reflection structure that is formed in a region between light-emitting regions adjacent to each other and reflects light emitted from the light-emitting layer. The surface-emitting light source according to claim 1, wherein the reflection structure has a reflection surface extending in a direction intersecting with the stacked surface of the light-emitting layers. A substrate,
A first electrode layer formed on the substrate and supporting the light emitting layer while being in contact therewith;
A second electrode layer formed in contact with the upper surface of the light emitting layer,
The reflective structure is a partition wall that stands on the first electrode layer so as to surround the light emitting layer so as to face the outer peripheral end face of the light emitting layer in each light emitting region and partition the light emitting layer into a plurality of light emitting regions. ,
The surface-emitting light source according to claim 2, wherein a side wall surface of the partition wall constitutes the reflection surface. The surface-emitting light source according to claim 3, wherein a transparent insulating layer is formed from a region between the outer peripheral end face of the light-emitting layer in each light-emitting region and the partition wall to an upper surface region of the partition wall. The surface-emitting light source according to claim 4, wherein the first electrode layer is a metal electrode, and the second electrode layer is a transparent electrode. The surface-emitting light source according to claim 5, wherein the partition wall and the first electrode layer are integrally formed of the same metal material. An auxiliary electrode layer made of metal is formed on the upper surface of the transparent insulating layer;
The surface-emitting light source according to claim 5, wherein the second electrode layer extends from the upper surface of the light-emitting layer to the upper surface of the auxiliary electrode layer. The second electrode layer extends from the top surface of the light emitting layer to the top surface of the transparent insulating layer;
The surface-emitting light source according to claim 5, wherein an auxiliary electrode layer made of metal is formed on an upper surface of the second electrode layer above the transparent insulating layer. The surface-emitting light source according to claim 5, further comprising a lens layer formed on the second electrode layer. The surface-emitting light source according to claim 4, wherein the first electrode layer is a transparent electrode, the second electrode layer is a metal electrode, and the substrate is a transparent substrate. The surface-emitting light source according to claim 10, wherein the partition wall and the first electrode layer are separately formed of different materials, and the partition wall is formed of a metal material. A transparent substrate;
A transparent electrode layer formed on the transparent substrate and supporting the light emitting layer while being in contact therewith,
A transparent insulating layer standing on the transparent electrode layer so as to surround the light emitting layer while being in contact with the outer peripheral end face of the light emitting layer in each light emitting region, and separating each light emitting region;
A metal electrode layer formed so as to cover the surface of the light emitting layer and the transparent insulating layer,
The surface emitting light source according to claim 2, wherein a part of the metal electrode layer also serves as the reflecting structure. The transparent insulating layer is
A first portion having a thickness greater than that of the light emitting layer and formed so as to surround the light emitting layer while being in contact with the outer peripheral end surface of the light emitting layer;
A second portion having a thickness smaller than that of the light emitting layer and formed integrally therewith so as to surround an outer periphery of the first portion;
The surface-emitting light source according to claim 12, wherein a surface of the metal electrode layer that contacts the side wall surface of the first portion constitutes the reflective surface. The surface-emitting light source according to any one of claims 10 to 13, wherein a lower surface of the substrate has a lens shape. The surface-emitting light source according to claim 3, wherein the partition wall has a film thickness larger than that of the light-emitting layer. A substrate,
A metal electrode layer formed on the substrate and supporting the light emitting layer in contact with the light emitting layer;
A transparent electrode layer formed so as to be in contact with the upper surface of the light emitting layer,
The reflective structure is erected on the first electrode layer via an insulating layer so as to surround the light emitting layer so as to oppose the outer peripheral end face of the light emitting layer in each light emitting region, and the light emitting layer is formed into a plurality of light emitting regions. A partition metal partition,
The surface-emitting light source according to claim 2, wherein a side wall surface of the metal partition wall constitutes the reflection surface. A transparent insulating layer formed in a region between the outer peripheral end face of the light emitting layer of each light emitting region and the metal partition,
The surface-emitting light source according to claim 16, wherein the transparent electrode layer is formed so as to cover the light-emitting layer, the transparent insulating layer, and the metal partition wall. Forming a metal electrode layer on the substrate;
Etching a plurality of regions spaced apart from each other in the metal electrode layer to a predetermined depth to form a plurality of recesses and metal partition walls separating the recesses;
Forming a transparent insulating layer so as to cover from the upper surface to the side wall surface of the metal partition;
Forming a light emitting layer on the bottom surface of each recess of the metal electrode layer;
Forming a transparent electrode layer so as to cover from the light emitting layer to the transparent insulating layer. The method for manufacturing a surface-emitting light source according to claim 18, wherein etching is performed such that a height of the metal partition wall is larger than a film thickness of the light-emitting layer. Forming a transparent electrode layer on the transparent substrate;
Forming a metal layer on the transparent electrode layer;
Selectively etching the metal layer until it reaches the transparent electrode layer to form a plurality of regions where the transparent electrode layer is exposed and metal partition walls separating these regions;
Forming a transparent insulating layer so as to cover from the upper surface to the side wall surface of the metal partition;
Forming a light emitting layer in the exposed region;
Forming a metal electrode layer so as to cover from the light emitting layer to the transparent insulating layer. The method for manufacturing a surface-emitting light source according to claim 18, wherein the metal layer is formed thicker than the light-emitting layer. Forming a transparent electrode layer on the transparent substrate;
Forming a transparent insulating layer on the transparent electrode layer so as to surround each of the plurality of spaced apart regions on the transparent electrode layer;
Forming a light emitting layer in each of the plurality of regions on the transparent electrode layer;
Forming a metal electrode layer so as to cover from the light emitting layer to the transparent insulating layer,
The transparent insulating layer is
A first portion having a larger film thickness than the light emitting layer and surrounding each of the plurality of regions;
A method of manufacturing a surface-emitting light source comprising: a second portion having a thickness smaller than that of the light-emitting layer and surrounding the outer periphery of the first portion so as to be integrated therewith. . Forming a metal electrode layer on the substrate;
Forming an opaque insulating layer on the metal electrode layer;
Forming a metal layer on the opaque insulating layer;
Selectively etching the metal layer until it reaches the opaque insulating layer to form a plurality of regions where the opaque insulating layer is exposed, and metal partition walls separating these regions;
Removing the opaque insulating layer exposed in the region to expose the metal electrode layer;
Forming a transparent insulating layer so as to cover a side wall surface of the metal partition;
Forming a light emitting layer on the metal electrode layer in the region where the opaque insulating layer has been removed;
Forming a transparent electrode layer so as to cover from the light emitting layer to the metal partition via the transparent insulating layer. The method for manufacturing a surface-emitting light source according to claim 23, wherein the metal layer is formed thicker than the light-emitting layer.

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