JP7744863B2 - Display and optical semiconductor element encapsulation sheets - Google Patents

Description

The present invention relates to a display body and a sheet for encapsulating optical semiconductor elements. More specifically, the present invention relates to a display body in which an optical semiconductor element, for example, of a self-luminous display device, is encapsulated, and a sheet suitable for use in encapsulating an optical semiconductor element.

In recent years, self-emitting display devices, such as mini/micro LED (Mini/Micro Light-Emitting Diode) displays, have been devised as next-generation display devices. Mini/micro LED displays basically use a substrate on which numerous tiny optical semiconductor elements (LED chips) are densely arranged as a display panel. The optical semiconductor elements are encapsulated with an encapsulant, and a cover member such as a resin film or glass plate is laminated on the outermost surface.

Display units equipped with self-luminous display devices such as mini/micro LED display devices have wiring (metal wiring) made of metal or metal oxides such as ITO arranged on the display panel substrate. Such display devices have the problem that, for example, when the lights are off, the metal wiring reflects light, making the screen look unattractive and reducing design appeal. For this reason, technology is being adopted that uses an anti-reflection layer to prevent reflections from the metal wiring as an encapsulant for sealing optical semiconductor elements.

In addition, displays using self-luminous display devices have the problem of uneven brightness (luminance unevenness) caused by the light source of the optical semiconductor element. When uneven brightness occurs, a phenomenon known as "color shift" occurs, in which the color changes when viewed from the front of the display and when viewed from an angle.

Patent Document 1 discloses an adhesive sheet capable of suppressing brightness unevenness, which is a laminate of a colored adhesive layer and a colorless adhesive layer, with the colorless adhesive layer positioned so as to come into contact with an optical semiconductor element. When this adhesive sheet is brought into contact with and conforms to the uneven shape formed by a substrate and an optical semiconductor element mounted on the substrate, the colorless adhesive layer comes into contact with the unevenness, and the unevenness is absorbed to some extent by the colorless adhesive layer, preventing compression or deformation of the colored adhesive layer. It is described as thereby suppressing unevenness in transmittance in the adhesive layer and suppressing brightness unevenness.

Japanese Patent Application Laid-Open No. 2020-169262

However, while adhesive sheets with colored adhesive layers are expected to prevent reflections from metal wiring and reduce brightness unevenness when encapsulating optical semiconductor elements, they have the problem of reducing the transmittance of light emitted by the optical semiconductor elements, resulting in reduced front brightness of the display. Reduced front brightness increases power consumption in order to increase brightness. Furthermore, the adhesive sheet in Patent Document 1 has the problem that the colored adhesive layer is unable to sufficiently absorb light emitted from the side of the optical semiconductor elements, resulting in strong interference between the light emitted by adjacent optical semiconductor elements and making it prone to color shift. For this reason, there is a demand for displays that are less prone to color shift and have high brightness.

The present invention was conceived in light of these circumstances, and its purpose is to provide a display that is less likely to undergo color shift and has high brightness. Another purpose of the present invention is to provide a sheet for encapsulating optical semiconductor elements that can be used to encapsulate optical semiconductor elements, thereby producing a display that is less likely to undergo color shift and has high brightness.

As a result of extensive research to achieve the above-mentioned objective, the inventors discovered that when multiple optical semiconductor elements arranged on a substrate are encapsulated with an encapsulating resin layer including a colored layer and a non-colored layer from the optical semiconductor element side, a display device in which the distance between the colored layers at a specific angle on the side of the optical semiconductor element at the end of a pixel adjacent to another pixel has a specific relationship with the distance between the colored layers on the front side of the optical semiconductor element, and in which the height of the optical semiconductor element and the thickness of the colored layer between pixels have a specific relationship, results in less color shift and higher brightness. The present invention was completed based on these findings.

That is, the present invention provides a display comprising a substrate, a plurality of optical semiconductor elements arranged on the substrate, and a sealing resin layer that seals the plurality of optical semiconductor elements,
the plurality of optical semiconductor elements are arranged for each pixel including a plurality of optical semiconductor elements,
the encapsulating resin layer has a colored layer and a non-colored layer in this order from the optical semiconductor element side,
In a vertical cross section with respect to the surface of the substrate, the cross section passes through the center of gravity of a first optical semiconductor element located at an end of a first pixel and the center of gravity of a second optical semiconductor element located at an end of a second pixel adjacent to the first pixel on the side of the first optical semiconductor element,
The substrate surface is the baseline,
A straight line parallel to the baseline and passing through the center of gravity of the first optical semiconductor element is called Line 1.
A straight line passing through the center of gravity of the first optical semiconductor element and pointing in the front direction at an angle of 15° from the line 1 is called a line 2;
When a straight line passing through the center of gravity of the first optical semiconductor element and in a front direction at an angle of 90° from the line 1 is defined as line 3,
The distance D1 at which the line 2 overlaps with the colored layer and the distance D2 at which the line 3 overlaps with the colored layer satisfy the following formula (1):
A display device is provided in which the distance D3 from the surface of the substrate to the front end of the first optical semiconductor element and the thickness D4 of the colored layer at the midpoint between the center of gravity of the first optical semiconductor element and the center of gravity of the second optical semiconductor element satisfy the following formula (2):
D1>D2 (1)
D3>D4 (2)

In the display device, the encapsulating resin layer that encapsulates the optical semiconductor element includes the colored layer, thereby preventing light reflection from metal wiring and the like provided on the substrate. Distance D1 corresponds to the thickness of the colored layer at a 75° angle relative to the front direction of the optical semiconductor element, and distance D2 corresponds to the thickness of the colored layer located in front of the optical semiconductor element. Distance D1 being greater than distance D2 means that the transmittance of light emitted by the optical semiconductor element in the front direction is higher than the transmittance of light emitted by the optical semiconductor element in a 75° angle toward adjacent pixels. Distance D3 corresponds to the height of the optical semiconductor element mounted on the substrate, and distance D4 corresponds to the thickness of the colored layer between pixels. Distance D3 being greater than thickness D4 means that light emitted by the optical semiconductor element in a front oblique direction can be adequately transmitted while suppressing interference between light emitted by the optical semiconductor element between pixels, thereby increasing front brightness. For this reason, a display that satisfies D1>D2 and D3>D4 has light emitted from the optical semiconductor element that is highly transparent in the front direction (e.g., 150° field of view) while maintaining low transparency in the lateral direction, making the display less susceptible to color shift and having high front brightness.

The encapsulating resin layer preferably includes a diffusion layer on the optical semiconductor element side of the colored layer. This configuration allows light emitted laterally by the optical semiconductor element to be diffused within the diffusion layer, further increasing front brightness.

It is preferable that the display be a self-luminous display device.

The display is preferably an image display device.

The present invention also provides a sheet for encapsulating a plurality of optical semiconductor elements arranged on a substrate for pixels each including a plurality of optical semiconductor elements, the sheet comprising:
the sheet includes a sealing resin layer including a colored layer and a non-colored layer;
When the plurality of optical semiconductor elements are encapsulated with the encapsulating resin layer so that the colored layer side faces the optical semiconductor elements, an encapsulating resin layer is formed,
In a vertical cross section with respect to the surface of the substrate, the cross section passes through the center of gravity of a first optical semiconductor element located at an end of a first pixel and the center of gravity of a second optical semiconductor element located at an end of a second pixel adjacent to the first pixel on the side of the first optical semiconductor element,
The substrate surface is the baseline,
A straight line parallel to the baseline and passing through the center of gravity of the first optical semiconductor element is called Line 1.
A straight line passing through the center of gravity of the first optical semiconductor element and pointing in the front direction at an angle of 15° from the line 1 is called a line 2;
When a straight line passing through the center of gravity of the first optical semiconductor element and in a front direction at an angle of 90° from the line 1 is defined as line 3,
A distance D1 at which the line 2 and the colored layer overlap, and a distance D2 at which the line 3 and the colored layer overlap, may satisfy the following formula (1):
The present invention provides a sheet for encapsulating optical semiconductor elements, in which a distance D3 from the surface of the substrate to the front end of the first optical semiconductor element and a thickness D4 of the colored layer at the midpoint between the center of gravity of the first optical semiconductor element and the center of gravity of the second optical semiconductor element satisfy the following formula (2):
D1>D2 (1)
D3>D4 (2)

The sealing resin layer preferably has a diffusion function layer on the side of the colored layer opposite the non-colored layer.

The display of the present invention is less likely to undergo color shift due to light emitted by the optical semiconductor element, and has high brightness. Therefore, the display can be viewed with the same color from a wide field of view. Furthermore, the display is bright and looks good without increasing power consumption. Furthermore, the sheet for encapsulating optical semiconductor elements of the present invention can encapsulate optical semiconductor elements, thereby providing a display that is less likely to undergo color shift and has high brightness.

FIG. 1 is a partial top view of an optical member in which a plurality of optical semiconductor elements are arranged on a substrate in pixel units. 1 is a partial cross-sectional view showing an embodiment of a display of the present invention. FIG. 3 is a partial enlarged view of the display shown in FIG. 2 . 3 is a partial cross-sectional view showing how an optical semiconductor element of the display shown in FIG. 2 emits light. FIG. FIG. 10 is a partial cross-sectional view showing how an optical semiconductor element of a conventional display emits light. FIG. 10 is a partial cross-sectional view showing another embodiment of the display of the present invention. FIG. 10 is a partial cross-sectional view showing still another embodiment of the display of the present invention. 1 is a cross-sectional view showing one embodiment of a sheet for encapsulating an optical semiconductor element of the present invention. 9 is a partial cross-sectional view showing a step of encapsulating an optical semiconductor element using the optical semiconductor element encapsulation sheet shown in FIG. 8. FIG.

[Display]
The display of the present invention includes at least a substrate, a plurality of optical semiconductor elements arranged on the substrate, and an encapsulating resin layer encapsulating the plurality of optical semiconductor elements. The display is a device for displaying information using light emitted by the optical semiconductor elements.

Examples of the optical semiconductor elements include light-emitting diodes (LEDs), such as blue light-emitting diodes, green light-emitting diodes, red light-emitting diodes, and ultraviolet light-emitting diodes.

The multiple optical semiconductor elements are arranged within one pixel (picture element) on the substrate, and multiple pixels are arranged. That is, the multiple optical semiconductor elements are arranged for each pixel, which includes multiple optical semiconductor elements. Figure 1 shows a partial top view of an optical element in which multiple optical semiconductor elements are arranged for each pixel on a substrate. In the optical element 11 shown in Figure 1, three optical semiconductor elements 3a-3c are arranged closely together on the substrate 2, and the three optical semiconductor elements 3a-3c form one pixel (pixel 3). Furthermore, three optical semiconductor elements 3d-3f are arranged closely together on the substrate 2, and the three optical semiconductor elements 3d-3f form one pixel (pixel 3'). Multiple pixels, such as pixel 3 and pixel 3', are arranged on the substrate 2.

The display of the present invention has an uneven shape formed by the substrate and the optical semiconductor elements, with the substrate surface between two optical semiconductor elements in the area where no optical semiconductor elements are located forming a recess and the optical semiconductor elements forming a protrusion.

The height of the optical semiconductor element on the substrate (the height from the substrate surface to the front edge of the optical semiconductor element) is preferably 500 μm or less. A height of 500 μm or less provides superior conformability of the encapsulating resin layer to the uneven shape.

The encapsulating resin layer preferably contacts the multiple optical semiconductor elements and conforms to the uneven shape. It is also preferable that the encapsulating resin layer collectively encapsulates the multiple optical semiconductor elements. In this specification, "encapsulating the optical semiconductor elements" refers to embedding at least a portion of the optical semiconductor elements in the encapsulating resin layer, or conforming to and covering the optical semiconductor elements with the encapsulating resin layer.

The encapsulating resin layer includes at least a colored layer and a non-colored layer, with the colored layer and the non-colored layer being arranged in this order from the optical semiconductor element side. In the encapsulating resin layer, the colored layer and the non-colored layer may be laminated directly or via another layer.

In a cross section perpendicular to the substrate surface, the cross section passes through the center of gravity of a first optical semiconductor element located at an end of a first pixel disposed on the substrate and the center of gravity of a second optical semiconductor element located at an end of the first optical semiconductor element in a second pixel adjacent to the first pixel, and the substrate surface is defined as a baseline. A straight line parallel to the baseline and passing through the center of gravity of the first optical semiconductor element is defined as Line 1. A straight line passing through the center of gravity of the first optical semiconductor element and extending in a front direction at an angle of 15° from Line 1 is defined as Line 2. A straight line passing through the center of gravity of the first optical semiconductor element and extending in a front direction at an angle of 90° from Line 1 is defined as Line 3. When the distance over which Line 2 overlaps with the colored layer is defined as D1 and the distance over which Line 3 overlaps with the colored layer is defined as D2, the display of the present invention satisfies the following formula (1) for D1 and D2: Furthermore, when the distance from the substrate surface to the front end of the first optical semiconductor element is D3 and the thickness of the colored layer at the midpoint between the center of gravity of the first optical semiconductor element and the center of gravity of the second optical semiconductor element is D4, the display of the present invention satisfies the following formula (2) for D3 and D4.
D1>D2 (1)
D3>D4 (2)

In the display device, the encapsulating resin layer that encapsulates the optical semiconductor element includes the colored layer, thereby preventing light reflection from metal wiring and the like provided on the substrate. Distance D1 corresponds to the thickness of the colored layer at a 75° angle relative to the front direction of the optical semiconductor element, and distance D2 corresponds to the thickness of the colored layer located in front of the optical semiconductor element. Distance D1 being greater than distance D2 means that the transmittance of light emitted by the optical semiconductor element in the front direction is higher than the transmittance of light emitted by the optical semiconductor element in a 75° angle toward adjacent pixels. Distance D3 corresponds to the height of the optical semiconductor element mounted on the substrate, and distance D4 corresponds to the thickness of the colored layer between pixels. Distance D3 being greater than distance D4 means that light emitted by the optical semiconductor element in a front oblique direction can be adequately transmitted while suppressing interference between light emitted by the optical semiconductor element between pixels, resulting in high front brightness. For this reason, a display that satisfies D1>D2 and D3>D4 has light emitted from the optical semiconductor element that is highly transparent in the front direction (e.g., 150° field of view) while maintaining low transparency in the lateral direction, making the display less susceptible to color shift and having high front brightness.

In this specification, "front" refers to the side from which the display is viewed, and is, for example, the upward direction in Figure 2 described below.

The display of the present invention will be described using the display shown in Figure 2, which is one embodiment of the display. The display 1 shown in Figure 2 comprises a substrate 2, multiple optical semiconductor elements 3b, 3c, 3d, and 3e arranged on the substrate 2, an encapsulating resin layer 4 that encapsulates these optical semiconductor elements 3b-3e, and a base material 5 bonded to the surface of the encapsulating resin layer 4 opposite the optical semiconductor elements 3b-3e. Figure 2 is an enlarged view of a vertical cross section with respect to the substrate 2, passing through the center of gravity of the optical semiconductor elements 3b-3e.

Each of the optical semiconductor elements 3b-3e is fixed to one substrate 2 by a support 31. The display unit 1 has an uneven shape formed by the substrate 2 and the optical semiconductor elements 3b-3e, with the surface of the substrate 2 in areas between the optical semiconductor elements 3b-3e where no optical semiconductor elements are arranged being recessed portions N and the optical semiconductor elements 3b-3e being protruding portions P.

Optical semiconductor elements 3b and 3c in Figure 2 are optical semiconductor elements 3b and 3c shown in Figure 1, and optical semiconductor elements 3a to 3c are located within the same pixel 3. Optical semiconductor elements 3d and 3e in Figure 2 are optical semiconductor elements 3d and 3e shown in Figure 1, and optical semiconductor elements 3d to 3f are located within the same pixel 3'. Pixel 3 and pixel 3' are adjacent pixels, and when pixel 3 is the first pixel, pixel 3' is the second pixel. Optical semiconductor element 3c is the first optical semiconductor element located at the end of pixel 3, and optical semiconductor element 3d is the second optical semiconductor element located at the end of pixel 3' and adjacent to optical semiconductor element 3c.

As shown in Figure 2, the encapsulating resin layer 4 contacts the multiple optical semiconductor elements 3b-3e and conforms to the uneven shape, encapsulating the multiple optical semiconductor elements 3b-3e collectively.

The encapsulating resin layer 4 is constructed by directly laminating a non-colored layer 41, a colored layer 42, and a non-colored layer 43 in this order, and encapsulates the optical semiconductor elements 3b-3e so that the non-colored layer 41 faces the optical semiconductor elements 3b-3e. The non-colored layer 41, which comes into contact with the optical semiconductor elements 3b-3e, conforms to the above-mentioned uneven shape, and the non-colored layer 41 and the colored layer 42 in the display unit 1 also have uneven shapes. Meanwhile, one surface of the non-colored layer 43 conforms to the uneven shape of the colored layer 42, resulting in an uneven shape that is the opposite of the uneven shape of the colored layer 42, and the other surface is flat. Note that the non-colored layer 41 and the non-colored layer 43 may each independently be a diffusion functional layer, as described below, or a non-diffusion functional layer.

FIG. 3 shows an enlarged view of the area between the optical semiconductor elements 3c and 3d of the display 1 shown in FIG. 2. In the display 1 shown in FIG. 3, the surface of the substrate 2 is defined as baseline B, and a line parallel to baseline B and passing through the center of gravity _G of the first optical semiconductor element 3c is line 1L1. A line passing through the center of gravity _G of the first optical semiconductor element 3c and extending forward at an angle of 15° from line 1L1 is line 2L2. A line passing through the center of gravity _G of the first optical semiconductor element 3c and extending forward at an angle of 90° from line 1L1 is line 3L3. Line 3L3 is a perpendicular line to baseline B that passes through the center of gravity _G. That is, θ1 in FIG. ₃ is 15°, and _θ2 is 90°. The distance at which line 2L2 and the colored layer 42 overlap is D1, and the distance at which line 3L3 and the colored layer 42 overlap is D2. The front end of the optical semiconductor element 3c is _TA . T _A is the portion of optical semiconductor element 3 c located closest to the front. The midpoint between the center of gravity G _C of optical semiconductor element 3 c and the center of gravity G _D of optical semiconductor element 3 d is C. The distance from the surface of substrate 2 to T _A is D3, and the thickness of colored layer 42 at midpoint C is D4. In display 1, D1 and D2 satisfy D1 > D2, and D3 and D4 satisfy D3 > D4.

In the display unit 1, the sealing resin layer 4 includes a colored layer 42, which prevents light reflection from metal wiring and the like provided on the substrate 2. Furthermore, by satisfying the relationship D1 and D2, the transmittance of light in the front direction is higher than the transmittance of light emitted by the optical semiconductor element 3c in a 75° oblique direction toward adjacent pixels. Furthermore, by satisfying the relationship D3 and D4, which satisfy the relationship D3 > D4, interference between the lights emitted by the optical semiconductor elements 3c and 3d is suppressed while allowing a moderate amount of light emitted by the optical semiconductor element 3c in a front oblique direction to be transmitted, resulting in high front brightness. Therefore, the light emitted by the optical semiconductor element has excellent transmittance in the front direction while maintaining low transmittance in the lateral direction, making the display unit less susceptible to color shift and having high front brightness.

Note that while Figure 3 illustrates a case in which the optical semiconductor element 3c located at the edge of a pixel satisfies the above formulas (1) and (2), the optical semiconductor element 3d located at the edge of an adjacent pixel may also satisfy the above formulas (1) and (2) together with or instead of the optical semiconductor element 3c.

4, the transmittance of light F _A emitted by optical semiconductor element 3 c toward the front and light F _B emitted by optical semiconductor element 3 d toward the front is excellent, resulting in high front brightness. On the other hand, the transmission of light R _A toward the right and light L _A toward the left emitted by optical semiconductor element 3 c, and light R _B toward the right and light L _B toward the left emitted by optical semiconductor element 3 d, is prevented by colored layer 42, which makes it difficult for the lights emitted by optical semiconductor elements 3 c and 3 d in adjacent pixels to interfere with each other, thereby suppressing color shift.

On the other hand, Figure 5 shows one embodiment of a conventional display. In the display shown in Figure 5, the thickness of the colored layer 42 between the optical semiconductor elements 3c and 3d is greater than the height of the optical semiconductor element 3c, such that D3 < D4. The transmission of light _RA to the right and light _LA to the left emitted by the optical semiconductor element 3c, and light RB to the right and light _LB to the left emitted by the optical semiconductor element _3d , is not easily impeded by the colored layer 42. This causes interference between the light emitted by the optical semiconductor elements 3c and 3d in adjacent pixels, making color shifts more likely. Furthermore, light emitted from the optical semiconductor elements 3c and 3d in a front-to-front oblique direction is less likely to pass through the colored layer 42, resulting in insufficient front brightness. In the embodiment shown in Figure 5, increasing the thickness of the colored layer 42 reduces the amount of light _FA and _FB emitted by the optical semiconductor elements 3c and 3d. Furthermore, decreasing the thickness of the colored layer 42 increases the transmittance of light in a front-to-front oblique direction, making color shifts more likely to occur. In contrast, the display of the present invention can provide high front luminance, prevention of color shift, and excellent anti-reflection properties.

In this way, in the display of the present invention, D1 and D2 satisfy D1 > D2, and D3 and D4 satisfy D3 > D4, so that the light emitted by the optical semiconductor element has excellent transmittance in the front direction while keeping transmittance in the lateral direction low, making color shift less likely to occur and providing high front brightness.

The center of gravity of an optical semiconductor element is determined by the three-dimensional shape of the optical semiconductor element. There are no particular limitations on the three-dimensional shape of the optical semiconductor element, and examples include rectangular prisms such as cubes and rectangular parallelepipeds, truncated pyramids, cylinders, truncated cones, and shapes with dome-shaped tops. When the three-dimensional shape of an optical semiconductor element is a regular prism, the center of gravity is the center of the optical semiconductor element.

The display unit 1 does not necessarily have to include the substrate 5. Furthermore, the number of optical semiconductor elements within one pixel does not have to be three, and is not particularly limited.

Another embodiment of the display of the present invention is shown in Figure 6. The display 1 shown in Figure 6 is similar to the display 1 shown in Figure 2, except that it does not include the non-colored layer 41. Specifically, in the display 1 shown in Figure 6, the encapsulating resin layer 4 is configured by directly laminating a colored layer 42 and a non-colored layer 43, in this order, from the optical semiconductor elements 3b-3e side, sealing the optical semiconductor elements 3b-3e so that the colored layer 42 faces the optical semiconductor elements 3b-3e. The colored layer 42 in contact with the optical semiconductor elements 3b-3e conforms to the above-mentioned uneven shape, while one surface of the non-colored layer 43 conforms to the uneven shape of the colored layer 42, resulting in an uneven shape that is the opposite of the uneven shape of the colored layer 42, and the other surface is flat. The display 1 shown in Figure 6 satisfies the above formulas (1) and (2). The non-colored layer 43 may be a diffusion functional layer, as described below, or a non-diffusion functional layer. In this way, the display of the present invention does not need to have a non-colored layer on the optical semiconductor element side of the colored layer.

Yet another embodiment of the display body of the present invention is shown in Figure 7. The display body 1 shown in Figure 7 is similar to the display body 1 shown in Figure 2, except that the front interface of the colored layer 42 is flat. Specifically, in the display body 1 shown in Figure 7, the encapsulating resin layer 4 is constructed by directly stacking a non-colored layer 41, a colored layer 42, and a non-colored layer 43 in this order from the optical semiconductor elements 3b-3e side, encapsulating the optical semiconductor elements 3b-3e so that the non-colored layer 41 side faces the optical semiconductor elements 3b-3e. The non-colored layer 41 in contact with the optical semiconductor elements 3b-3e conforms to the above-mentioned uneven shape, and the colored layer 42 in the display body 1 also has an uneven shape. Meanwhile, one surface of the colored layer 42 conforms to the uneven shape of the non-colored layer 41, thereby having an uneven shape that is the opposite of the uneven shape of the non-colored layer 41, and the other surface is flat. Both surfaces of the non-colored layer 43 are flat. The display element 1 shown in Figure 7 satisfies the above formulas (1) and (2). Note that the non-colored layer 41 and the non-colored layer 43 may each independently be a diffusion functional layer (described below) or a non-diffusion functional layer.

In the vertical cross section, D3 is preferably longer than the distance from the substrate surface to the substrate-side interface of the colored layer on a line perpendicular to the substrate surface that passes through the midpoints of the first and second optical semiconductor elements. In this case, the substrate-side interface of the colored layer is likely to be located close to the substrate on the side of the optical semiconductor element, and light emitted by the optical semiconductor element in the lateral direction is absorbed by the colored layer, reducing transmittance and making color shift less likely to occur. In the display 1 shown in Figures 2, 6, and 7, D3 is longer than the distance from the substrate surface to the substrate-side interface of the colored layer on a line perpendicular to the substrate surface that passes through the midpoints of the first and second optical semiconductor elements.

In the vertical cross section, D3 is preferably longer than the distance from the substrate surface to the front interface of the colored layer on a line perpendicular to the substrate surface that passes through the midpoints of the first and second optical semiconductor elements. In this case, the light emitted from the optical semiconductor elements in the lateral direction is absorbed by the colored layer, reducing transmittance and making color shift less likely to occur. In the display 1 shown in Figures 2 and 6, D3 is longer than the distance from the substrate surface to the front interface of the colored layer on a line perpendicular to the substrate surface that passes through the midpoints of the first and second optical semiconductor elements.

The cross-sectional views of the display body shown in Figures 2 to 7 can be obtained, for example, by exposing the cross section by cutting the display body in a cooled state perpendicular to the substrate surface so as to pass through the center of gravity of multiple optical semiconductor elements. Cooling the display body can prevent the encapsulating resin layer from melting or deforming due to the heat generated during cutting. Cutting can be performed using known or conventional cutting devices such as laser beam or ion beam irradiators. After cutting, the exposed cross section may be milled to expose a cross section with a lower degree of deformation. The cooling temperature is set appropriately within a range that prevents the degree of deformation of the encapsulating resin layer and cracking of the display body.

<Sealing resin layer>
The encapsulating resin layer includes at least the colored layer and the non-colored layer. Each layer (the colored layer and the non-colored layer) constituting the encapsulating resin layer may be a single layer within the encapsulating resin layer, or multiple layers having the same or different compositions. When multiple colored layers and non-colored layers are included, the multiple layers may be stacked in contact with each other or may be stacked separately (e.g., two colored layers stacked with one non-colored layer interposed therebetween). When the encapsulating resin layer includes one or more colored layers and non-colored layers, for at least one combination of colored layer and non-colored layer, the colored layer and non-colored layer must be in this order from the optical semiconductor element side, and these colored layers and non-colored layers must satisfy D1 > D2 and D3 > D4. Furthermore, the total number of layers constituting the encapsulating resin layer is two or more, including the colored layer and the non-colored layer, and may be three or more. From the viewpoint of reducing the thickness of the display, the total number of layers may be, for example, 10 or less, 5 or less, or 4 or less.

The encapsulating resin layer preferably includes a diffusion layer. This configuration allows light emitted by the optical semiconductor element to be diffused within the diffusion layer, further increasing the front brightness. The diffusion layer is preferably a layer that corresponds to the non-colored layer in this specification. In Figure 2, the non-colored layer 41 is preferably a diffusion layer. In Figures 2, 6, and 7, the non-colored layer 43 may be a diffusion layer or a non-diffusion layer.

When the encapsulating resin layer includes the diffusion layer, it is preferable that the encapsulating resin layer include, in this order from the optical semiconductor element side, the diffusion layer, the colored layer, and the non-colored layer. The non-colored layer may be either a diffusion layer or a non-diffusion layer. This configuration can further increase the front brightness while improving the appearance of the display both when the light is off and when the light is on. In Figures 2 and 7, the encapsulating resin layer 4 includes, in this order from the optical semiconductor element side, the non-colored layer 41, which is a diffusion layer, the colored layer 42, and the non-colored layer 43. The non-colored layer 43 may be either a diffusion layer or a non-diffusion layer.

In the display of the present invention, it is preferable that at least one surface of the colored layer (particularly the surface facing the optical semiconductor element) has an uneven shape that follows the uneven shape. In this case, the display of the present invention is more likely to satisfy the above formulas (1) and (2). The colored layer may also have an uneven shape on the front surface that follows the uneven shape. In the display 1 shown in Figures 2 and 6, the colored layer 42 has an uneven shape on both the front surface and the optical semiconductor element side. In the display 1 shown in Figure 7, the colored layer 42 has an uneven shape on the front surface.

In the display of the present invention, the non-colored layer located closer to the front than the colored layer preferably has a flat front surface. In this case, diffuse reflection of external light is less likely to occur on the surface of the sealing resin layer, improving the appearance of the display both when the light is off and when it is on. In the display 1 shown in Figures 2, 6, and 7, the non-colored layer 43 has a flat front surface.

In the display member of the present invention, the non-colored layer may be provided on the optical semiconductor element side of the colored layer. That is, the encapsulating resin layer may include the non-colored layer and the colored layer in this order, starting from the optical semiconductor element side. Furthermore, when the non-colored layer is provided on the optical semiconductor element side of the colored layer, it is preferable that both surfaces of the non-colored layer have an uneven shape that follows the uneven shape. This configuration makes it easier for the colored layer to have an uneven shape. In the display member 1 shown in Figures 2 and 7, the encapsulating resin layer 4 includes the non-colored layer 41 and the colored layer 42, starting from the optical semiconductor element 3b-3e side, in this order, and the non-colored layer 41 has an uneven shape that follows the uneven shape on both surfaces.

The non-colored layer provided on the optical semiconductor element side of the colored layer is preferably a diffusion layer. This configuration allows light emitted from the optical semiconductor element in the lateral direction to be diffused within the diffusion layer, thereby increasing the front brightness.

Each layer (the colored layer and the non-colored layer) constituting the encapsulating resin layer may or may not independently have adhesive properties. Adhesive properties are preferred. This configuration allows the encapsulating resin layer to easily encapsulate the optical semiconductor element, and provides excellent adhesion between the layers, resulting in superior encapsulation of the optical semiconductor element. In particular, it is preferred that at least the layer in contact with the optical semiconductor element be adhesive. This configuration provides excellent conformability and embedding of the optical semiconductor element by the encapsulating resin layer. As a result, excellent design is achieved even when the step caused by the optical semiconductor element is high. Note that layers other than the layer in contact with the optical semiconductor element do not need to be adhesive. In this case, adhesion between adjacent encapsulating resin layers is low in a tiling state, and when adjacent small-sized stacks (stacks in which encapsulating resin layers encapsulate optical semiconductor elements arranged on a substrate) are separated from each other, damage to the encapsulating resin layer and adhesion of adjacent encapsulating resin layers are unlikely to occur.

(colored layer)
The colored layer in the display of the present invention is a layer intended to prevent light reflection from metal wiring or the like provided on the substrate of the display. The colored layer contains at least a colorant. The colored layer is preferably a resin layer composed of a resin. The colorant may be a dye or a pigment as long as it is soluble or dispersible in the colored layer. Dyes are preferred because they can achieve low haze even with a small amount of addition, do not tend to settle like pigments, and are easily distributed uniformly. Pigments are also preferred because they provide high color expression even with a small amount of addition. When a pigment is used as a colorant, it is preferable that it has low or no conductivity. One or more of the colorants may be used.

The above-mentioned colorant is preferably a black colorant. Known or commonly used colorants (pigments, dyes, etc.) for producing black can be used as the black colorant. Examples include carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, pine soot, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (non-magnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complexes, anthraquinone-based colorants, and zirconium nitride. It is also possible to use a colorant that functions as a black colorant by combining colorants that produce colors other than black.

From the viewpoint of imparting appropriate anti-reflection properties to the display, the content of the colorant in the colored layer is preferably 0.2% by mass or more, and more preferably 0.4% by mass or more, relative to the total amount (100% by mass) of the colored layer. The content of the colorant is, for example, 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less. The content may be set appropriately depending on the type of colorant, the color tone and light transmittance of the display, etc. The colorant may be added to the composition as a solution or dispersion dissolved or dispersed in an appropriate solvent.

The haze value (initial haze value) of the colored layer is not particularly limited, but from the viewpoint of ensuring front luminance and visibility of the display, it is preferably 50% or less, more preferably 40% or less, even more preferably 30% or less, and particularly preferably 20% or less. Furthermore, from the viewpoint of efficiently reducing luminance unevenness in the display, the haze value of the colored layer is preferably 1% or more, more preferably 3% or more, even more preferably 5% or more, and particularly preferably 8% or more, and may even be 10% or more. The haze value is the value at the thickest part of the colored layer in the display.

The total light transmittance of the colored layer is not particularly limited, but from the viewpoint of further improving the anti-reflection function of metal wiring and the contrast of the display, it is preferably 40% or less, more preferably 30% or less, even more preferably 25% or less, and particularly preferably 20% or less. Furthermore, from the viewpoint of ensuring the brightness of the display, the total light transmittance of the colored layer is preferably 0.5% or more, more preferably 1% or more, even more preferably 1.5% or more, and particularly preferably 2% or more, and may even be 2.5% or more, or 3% or more. The total light transmittance is the value at the thickest part of the colored layer in the display.

The haze value and total light transmittance of the colored layer are each values for a single layer and can be measured using the methods specified in JIS K7136 and JIS K7361-1. They can be controlled by the type and thickness, the type and amount of colorant, etc.

(Non-colored layer)
The non-colored layer is a layer different from the colored layer and is not intended to prevent light reflection by metal wiring or the like provided on a substrate in a display device. The non-colored layer may be a colorless layer or may be slightly colored. Furthermore, the non-colored layer may be, for example, a diffusion functional layer intended to perform the function of diffusing light, or a non-diffusion functional layer intended not to perform the function of diffusing light. The non-colored layer may be transparent or non-transparent. The non-colored layer is preferably a resin layer made of resin.

The colorant content in the non-colored layer is preferably less than 0.2% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.05% by mass, relative to 100% by mass of the total amount of the non-colored layer, and may be less than 0.01% by mass or less than 0.005% by mass.

The total light transmittance of the non-colored layer is not particularly limited, but from the viewpoint of ensuring the brightness of the display, it is preferably 40% or more, more preferably 60% or more, even more preferably 70% or more, and particularly preferably 80% or more. Furthermore, the upper limit of the total light transmittance of the non-colored layer is not particularly limited, but it may be less than 100%, or may be 99.9% or less, or 99% or less. The total light transmittance is the value at the thickest part of the non-colored layer in the display.

The total light transmittance of the above-mentioned non-colored layer is a value for a single layer and can be measured using the methods specified in JIS K7136 and JIS K7361-1. It can be controlled by the type and thickness of the non-colored layer.

The diffusion layer is a layer intended to diffuse light. When the encapsulating resin layer includes the diffusion layer, light emitted from the optical semiconductor element is diffused within the diffusion layer. For example, light emitted from the side of the optical semiconductor element is emitted toward the front of the display, improving the front brightness of the display. The diffusion layer is preferably a resin layer made of resin. The diffusion layer is not limited, but preferably contains light-diffusing fine particles. That is, the diffusion layer preferably contains light-diffusing fine particles dispersed in the resin layer. Only one type of light-diffusing fine particles may be used, or two or more types may be used.

The light-diffusing microparticles have an appropriate refractive index difference from the resin that makes up the diffusion layer, and impart diffusion properties to the diffusion layer. Examples of light-diffusing microparticles include inorganic microparticles and polymeric microparticles. Examples of inorganic microparticle materials include silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, and metal oxides. Examples of polymeric microparticle materials include silicone resins, acrylic resins (including polymethacrylate resins such as polymethyl methacrylate), polystyrene resins, polyurethane resins, melamine resins, polyethylene resins, and epoxy resins.

The polymeric fine particles are preferably fine particles made of silicone resin. Furthermore, the inorganic fine particles are preferably fine particles made of metal oxide. The metal oxide is preferably titanium oxide or barium titanate, more preferably titanium oxide. This configuration provides the diffusion functional layer with superior light diffusion properties and further reduces brightness unevenness.

The shape of the light-diffusing microparticles is not particularly limited and may be, for example, spherical, flat, or irregular.

From the viewpoint of providing appropriate light diffusion performance, the average particle diameter of the light-diffusing microparticles is preferably 0.1 μm or more, more preferably 0.15 μm or more, even more preferably 0.2 μm or more, and particularly preferably 0.25 μm or more. Furthermore, from the viewpoint of preventing the haze value from becoming too high and displaying high-resolution images, the average particle diameter of the light-diffusing microparticles is preferably 12 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less. The average particle diameter can be measured, for example, using a Coulter counter.

The refractive index of the light-diffusing fine particles is preferably 1.2 to 5, more preferably 1.25 to 4.5, even more preferably 1.3 to 4, and particularly preferably 1.35 to 3.

The absolute value of the refractive index difference between the light-diffusing microparticles and the resin constituting the diffusion function layer (the resin layer in the diffusion function layer excluding the light-diffusing microparticles) is preferably 0.001 or more, more preferably 0.01 or more, even more preferably 0.02 or more, and particularly preferably 0.03 or more, and may be 0.04 or more, or even 0.05 or more, from the viewpoint of more efficiently reducing brightness unevenness in the display. Furthermore, the absolute value of the refractive index difference between the light-diffusing microparticles and the resin is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less, from the viewpoint of preventing the haze value from becoming too high and displaying high-resolution images.

From the viewpoint of imparting appropriate light diffusion performance to the encapsulating resin layer, the content of the light-diffusing microparticles in the diffusion function layer is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and particularly preferably 0.15 parts by mass or more, per 100 parts by mass of the resin constituting the diffusion function layer. Furthermore, from the viewpoint of preventing the haze value from becoming too high and displaying high-resolution images, the content of the light-diffusing microparticles is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, per 100 parts by mass of the resin constituting the diffusion function layer.

The haze value (initial haze value) of the diffusion functional layer is not particularly limited, but from the perspective of efficiently reducing brightness unevenness, it is preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, and particularly preferably 60% or more. It may be 70% or more, 80% or more, 90% or more, 95% or more, or 97% or more, and a value around 99.9% is preferable as it has a superior effect of improving brightness unevenness. The upper limit of the haze value of the diffusion functional layer is not particularly limited, and may be 100%. The haze value is the value at the thickest part of the diffusion functional layer in the display.

The total light transmittance of the diffusion function layer is not particularly limited, but from the perspective of ensuring brightness, it is preferably 40% or more, more preferably 60% or more, even more preferably 70% or more, and particularly preferably 80% or more. Furthermore, the upper limit of the total light transmittance of the diffusion function layer is not particularly limited, but it may be less than 100%, or may be 99.9% or less, or 99% or less. The total light transmittance is the value at the thickest part of the diffusion function layer in the display.

The haze value and total light transmittance of the above-mentioned diffusion functional layer are each values for a single layer and can be measured using the methods specified in JIS K7136 and JIS K7361-1. They can be controlled by the type and thickness of the diffusion functional layer, the type and amount of light-diffusing microparticles, etc.

The haze value (initial haze value) of the non-diffusion functional layer is not particularly limited, but from the perspective of achieving excellent brightness in the display, it is preferably less than 30%, more preferably 10% or less, even more preferably 5% or less, and particularly preferably 1% or less, and may even be 0.5% or less. There is no particular limit to the lower limit of the haze value of the non-diffusion functional layer. The haze value is the value at the thickest part of the non-diffusion functional layer in the display.

The total light transmittance of the non-diffusion functional layer is not particularly limited, but from the perspective of ensuring the brightness of the display, it is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more. Furthermore, the upper limit of the total light transmittance of the non-diffusion functional layer is not particularly limited, but it may be less than 100%, or may be 99.9% or less, or 99% or less. The total light transmittance is the value at the thickest part of the non-diffusion functional layer in the display.

The haze value and total light transmittance of the non-diffusion functional layer are values for a single layer and can be measured using the methods specified in JIS K7136 and JIS K7361-1. They can be controlled by the type and thickness of the non-diffusion functional layer.

From the viewpoint of achieving excellent brightness of the display, the content of colorant and/or light-diffusing fine particles in the non-diffusion functional layer is preferably less than 0.01 parts by mass, and more preferably less than 0.005 parts by mass, per 100 parts by mass of the resin constituting the non-diffusion functional layer.

(Resin layer)
When the colored layer and the non-colored layer are resin layers, the resin constituting the resin layer may be a known or commonly used resin, such as an acrylic resin, a urethane acrylate resin, a urethane resin, a rubber resin, an epoxy resin, an epoxy acrylate resin, an oxetane resin, a silicone resin, a silicone acrylic resin, a polyester resin, a polyether resin (such as polyvinyl ether), a polyamide resin, a fluorine-containing resin, a vinyl acetate/vinyl chloride copolymer, or a modified polyolefin. One or more of the resins may be used. The resins constituting each layer of the encapsulating resin layer may be the same or different.

When the resin layer is an adhesive layer (adhesive layer), a known or commonly used pressure-sensitive adhesive can be used as the resin. Examples of such adhesives include acrylic adhesives, rubber adhesives (natural rubber, synthetic rubber, and mixtures thereof), silicone adhesives, polyester adhesives, urethane adhesives, polyether adhesives, polyamide adhesives, and fluorine adhesives. One or more of the above adhesives may be used.

The resin layer may contain other components in addition to the components described above, as long as the effects of the present invention are not impaired in each layer. Examples of such other components include curing agents, crosslinking accelerators, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), oligomers, antioxidants, fillers (metal powders, organic fillers, inorganic fillers, etc.), antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, UV absorbers, polymerization inhibitors, granular materials, and foil-like materials. Only one of the above other components may be used, or two or more may be used.

Examples of the laminate structure of the encapsulating resin layer include [colored layer/diffusion functional layer], [colored layer/non-diffusion functional layer], [colored layer/diffusion functional layer/non-diffusion functional layer], [colored layer/non-diffusion functional layer/diffusion functional layer], [diffusion functional layer/colored layer/non-diffusion functional layer], [non-diffusion functional layer/colored layer/diffusion functional layer], [diffusion functional layer/colored layer/diffusion functional layer], and [non-diffusion functional layer/colored layer/non-diffusion functional layer] (all in order from the optical semiconductor element side).

<Base material part>
The display of the present invention may or may not include a substrate. When the substrate is provided on the front side of the encapsulating resin layer in the display, the surface of the encapsulating resin layer can be made flat, thereby reducing the occurrence of diffused reflection of light and improving the appearance of the display both when the light is off and when the light is on. Furthermore, by forming an anti-glare layer or an anti-reflection layer described below on the substrate, the display can be imparted with anti-glare properties or anti-reflection properties. Furthermore, the substrate serves as a support for the encapsulating resin layer in the sheet for encapsulating optical semiconductor elements described below, and by providing the substrate, the sheet for encapsulating optical semiconductor elements has excellent handleability.

The substrate portion may be a single layer, or may be multiple layers that are the same or have different compositions, thicknesses, etc. When the substrate portion is multiple layers, each layer may be bonded to another layer such as an adhesive layer. Note that the substrate layer used in the substrate portion is the part that is attached to the substrate that includes the optical semiconductor element together with the encapsulating resin layer; the "substrate portion" does not include release liners that are peeled off when the optical semiconductor element encapsulation sheet is used (attached), or surface protection films that merely protect the surface of the substrate portion.

Examples of the substrate layer constituting the substrate portion include glass and plastic substrates (particularly plastic films). Resins constituting the plastic substrate include, for example, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, very low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ionomers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester (random, alternating) copolymers, ethylene-vinyl acetate copolymers (EVA), ethylene-propylene copolymers, cyclic olefin polymers, ethylene-butene copolymers, and ethylene-hexene copolymers. Examples of suitable resins include polyolefin resins, polyurethanes, polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, and polybutylene terephthalate (PBT); polycarbonates, polyimide resins, polyether ether ketones, polyetherimides, polyamides such as aramids and wholly aromatic polyamides, polyphenyl sulfides, fluororesins, polyvinyl chloride, polyvinylidene chloride, cellulose resins such as triacetyl cellulose (TAC), silicone resins, acrylic resins such as polymethyl methacrylate (PMMA), polysulfones, polyarylates, and polyvinyl acetates. These resins may be used singly or in combination. The substrate layer may be an anti-reflection (AR) film, a polarizing plate, a retardation plate, or any of a variety of other optical films.

The thickness of the plastic film is preferably 20 to 300 μm, and more preferably 40 to 250 μm. If the thickness is 20 μm or more, the supportability and handleability of the optical semiconductor element encapsulation sheet will be improved. If the thickness is 300 μm or less, the display body can be made thinner.

The surface of the substrate on the side bearing the encapsulating resin layer may be subjected to surface treatments such as physical treatments such as corona discharge treatment, plasma treatment, sand matting treatment, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, and ionizing radiation treatment; chemical treatments such as chromate treatment; and adhesion-enhancing treatments using a coating agent (primer) in order to improve adhesion and retention with the encapsulating resin layer. Surface treatments to improve adhesion are preferably applied to the entire surface of the substrate on the side facing the encapsulating resin layer.

The thickness of the substrate is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of excellent support function and surface scratch resistance. The thickness of the substrate is preferably 300 μm or less, more preferably 250 μm or less, from the viewpoint of excellent transparency.

<Display body>
The display may include a layer having antiglare and/or antireflection properties. Such a configuration can suppress the gloss and light reflection of the display, improving its appearance. An example of the layer having antiglare properties is an antiglare-treated layer. An example of the layer having antireflection properties is an antireflection-treated layer. The antiglare treatment and the antireflection treatment can be performed by known or conventional methods. The antiglare layer and the antireflection layer may be the same layer or different layers. The display may have only one layer having antiglare and/or antireflection properties, or two or more layers.

The haze value (initial haze value) of the encapsulating resin layer or of the laminate having the encapsulating resin layer and the substrate portion as both end faces is not particularly limited, but from the perspective of achieving a superior effect in suppressing brightness unevenness and designability, it is preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, and particularly preferably 95% or more. There is no particular upper limit to the haze value.

The total light transmittance of the encapsulating resin layer or the laminate having the encapsulating resin layer and the substrate portion as both end faces is not particularly limited, but from the viewpoint of further improving the anti-reflection function of metal wiring and the like and contrast, it is preferably 40% or less, more preferably 30% or less, and even more preferably 20% or less. Furthermore, from the viewpoint of ensuring brightness, the total light transmittance is preferably 0.5% or more.

The haze value and total light transmittance can be measured by the methods specified in JIS K7136 and JIS K7361-1, respectively, and can be controlled by the stacking order, type, and thickness of the layers that make up the encapsulating resin layer and the base material.

The thickness of the encapsulating resin layer, or the laminate having the encapsulating resin layer and the substrate as both end faces, is preferably 10 to 600 μm, more preferably 20 to 550 μm, even more preferably 30 to 500 μm, even more preferably 40 to 450 μm, and particularly preferably 50 to 400 μm, from the perspective of improving the anti-reflection function and contrast of metal wiring and the like while more efficiently reducing color shift. Note that the release liner is not included in the above thickness.

The display of the present invention preferably includes a self-luminous display device. The self-luminous display device can be combined with a display panel, if necessary, to form an image display device. In this case, the optical semiconductor elements are LED elements. Examples of the self-luminous display device include LED displays, backlights, and organic electroluminescence (organic EL) display devices. The backlight is preferably a full-surface direct backlight. The backlight includes, as at least a portion of its components, a laminate comprising the substrate and multiple optical semiconductor elements arranged on the substrate. For example, in the self-luminous display device, a metal wiring layer is laminated on the substrate for sending light-emission control signals to each LED element. The LED elements emitting red (R), green (G), and blue (B) light are alternately arranged on the substrate via the metal wiring layer. The metal wiring layer is made of a metal such as copper, and adjusts the light emission intensity of each LED element to display each color.

The display of the present invention may be a display that is used by folding, such as a foldable image display device (flexible display) (particularly a foldable image display device (foldable display)). Specific examples include displays equipped with a foldable backlight and displays equipped with a foldable self-luminous display device.

In the display of the present invention, the encapsulating resin layer has excellent conformability and embeddability for optical semiconductor elements, so the optical semiconductor elements may be mini LED elements or micro LED elements.

The display of the present invention is less susceptible to color shift due to the light emitted by the optical semiconductor element and has high brightness. Therefore, the display can be viewed with the same color from a wide field of view. The display also has a bright and attractive appearance without increasing power consumption. Furthermore, the display of the present invention suppresses light reflection from metal wiring on the substrate, resulting in a beautiful appearance even when the optical semiconductor element is not lit.

[Display body manufacturing method]
The display member of the present invention can be produced by laminating a sheet for encapsulating an optical semiconductor element, which includes an encapsulating resin layer, to a substrate on which an optical semiconductor element is arranged, and encapsulating the optical semiconductor element with the encapsulating resin layer.

(Optical semiconductor element encapsulation sheet)
The optical semiconductor element encapsulation sheet is a sheet for encapsulating a plurality of optical semiconductor elements arranged on a substrate. The optical semiconductor element encapsulation sheet includes at least an encapsulating resin layer including a colored layer and a non-colored layer. The optical semiconductor element encapsulation sheet is a sheet that can satisfy the above formulas (1) and (2) when the encapsulating resin layer is formed by encapsulating the plurality of optical semiconductor elements with the encapsulating resin layer so that the colored layer side faces the optical semiconductor elements. The optical semiconductor element encapsulation sheet of the present invention can provide a display that is less likely to undergo color shift and has high brightness by encapsulating optical semiconductor elements.

The optical semiconductor element encapsulation sheet includes at least an encapsulating resin layer including a colored layer and a non-colored layer. The encapsulating resin layer is a layer that can form the encapsulating resin layer in the display of the present invention. Specifically, the colored layer in the encapsulating resin layer is a layer that can form the colored layer in the display of the present invention, and the non-colored layer in the encapsulating resin layer is a layer that can form the non-colored layer in the display of the present invention. Specifically, the colored layer in the encapsulating resin layer may be a layer that has the same composition (components and their blending ratios) and physical properties (haze, total light transmittance, etc.) as the colored layer in the display of the present invention, or may be a layer that becomes the colored layer in the display of the present invention upon curing. Furthermore, the non-colored layer in the encapsulating resin layer may be a layer that has the same composition (components and their blending ratios) and physical properties (haze, total light transmittance, etc.) as the non-colored layer in the display of the present invention, or may be a layer that becomes the non-colored layer in the display of the present invention upon curing.

The encapsulating resin layer is designed appropriately depending on the structure of the encapsulating resin layer in the display of the present invention. For example, if the display of the present invention includes the diffusion layer, the encapsulating resin layer in the optical semiconductor element encapsulation sheet also includes a diffusion layer. The diffusion layer in the encapsulating resin layer may be a layer having the same composition (constituent components and their blending ratio) and physical properties (haze, total light transmittance, etc.) as the diffusion layer in the display of the present invention, or it may be a layer that becomes the diffusion layer in the display of the present invention upon curing. Furthermore, the encapsulating resin layer preferably comprises the diffusion layer, the colored layer, and the non-colored layer in this order. The diffusion layer is a layer that corresponds to either the colored layer or the non-colored layer.

Each layer (the colored layer and the non-colored layer) constituting the encapsulating resin layer may or may not independently have tackiness and/or adhesiveness. Among these, tackiness and/or adhesiveness are preferred. This configuration allows the encapsulating resin layer to be easily attached to the substrate and the optical semiconductor element, and provides excellent adhesion between the layers, resulting in superior encapsulation of the optical semiconductor element. In particular, it is preferred that at least the layer in contact with the optical semiconductor element has tackiness and/or adhesiveness. This configuration provides excellent conformability and embedding of the optical semiconductor element by the encapsulating resin layer. As a result, excellent design is achieved even when the step caused by the optical semiconductor element is high.

Each layer constituting the encapsulating resin layer (the colored layer and the non-colored layer) may independently be a resin layer that has the property of being cured by irradiation with radiation (a radiation-curable resin layer), or a resin layer that does not have the property of being cured by irradiation with radiation (a non-radiation-curable resin layer). Examples of the radiation include electron beams, ultraviolet rays, alpha rays, beta rays, gamma rays, and X-rays. When the colored layer is a radiation-curable resin layer, the colorant contained in the colored layer preferably absorbs visible light and is transparent to light of a wavelength that can cure the radiation-curable resin layer.

The optical semiconductor element encapsulation sheet may include the substrate portion. When the substrate portion is included, the encapsulating resin layer may be provided on at least one surface of the substrate portion. The surface of the encapsulating resin layer that comes into contact with the substrate portion is the surface opposite to the side of the encapsulating resin layer that comes into contact with the optical semiconductor element. When the optical semiconductor element encapsulation sheet includes the substrate portion, the optical semiconductor element encapsulation sheet, together with the substrate portion, is attached to the optical semiconductor element and the substrate, and the substrate portion of the optical semiconductor element encapsulation sheet becomes the substrate portion of the display of the present invention.

The encapsulating resin layer may also be formed on a release-treated surface of a release liner. When the optical semiconductor element encapsulation sheet is formed on the release liner, the side of the encapsulating resin layer that contacts the optical semiconductor element becomes the side that comes into contact with the release liner. When the substrate portion is not present, both sides of the encapsulating resin layer may come into contact with the release liner. The release liner is used as a protective material for the optical semiconductor element encapsulation sheet and is peeled off when the optical semiconductor element is encapsulated. The substrate portion and release liner are not necessarily provided.

The release liner is an element that covers and protects the surface of the optical semiconductor element encapsulation sheet, and is peeled off from the sheet when the optical semiconductor element encapsulation sheet is attached to a substrate on which an optical semiconductor element is disposed.

Examples of the release liner include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, and plastic films and papers whose surfaces are coated with release agents such as fluorine-based release agents and long-chain alkyl acrylate release agents.

The thickness of the release liner is, for example, 10 to 200 μm, preferably 15 to 150 μm, and more preferably 20 to 100 μm. If the thickness is 10 μm or more, the release liner is less likely to break due to cuts during processing. If the thickness is 200 μm or less, the release liner is more easily peeled from the optical semiconductor element encapsulation sheet during use.

One embodiment of the optical semiconductor element encapsulation sheet will be described using Figure 8. Figure 8 is a cross-sectional view of the optical semiconductor element encapsulation sheet capable of forming the display shown in Figure 2. As shown in Figure 8, the optical semiconductor element encapsulation sheet 10 can be used to encapsulate one or more optical semiconductor elements arranged on a substrate, and includes a substrate 5 and an encapsulating resin layer 7 formed on the substrate 5. The encapsulating resin layer 7 is formed from a laminate of a non-colored layer 71, a colored layer 72, and a non-colored layer 73. The non-colored layer 71, the colored layer 72, and the non-colored layer 73 are adhesive and directly laminated to one another. A release liner 6 is attached to the surface of the non-colored layer 71 of the encapsulating resin layer 7, and the substrate 5 is attached to the surface of the non-colored layer 73.

(Sealing process)
The method for producing a display member of the present invention using the optical semiconductor element encapsulation sheet includes an encapsulation step of laminating the optical semiconductor element encapsulation sheet to a substrate on which optical semiconductor elements are arranged and encapsulating the optical semiconductor elements with an encapsulating resin layer. Specifically, the encapsulation step first involves peeling the release liner from the optical semiconductor element encapsulation sheet to expose the encapsulating resin layer. Then, of a laminate (such as an optical member) including a substrate and optical semiconductor elements (preferably multiple optical semiconductor elements) arranged on the substrate, the encapsulating resin layer surface, which is the exposed surface of the optical semiconductor element encapsulation sheet, is laminated to the substrate surface on which the optical semiconductor elements are arranged. If the laminate includes multiple optical semiconductor elements, the encapsulating resin layer is further arranged to fill gaps between the multiple optical semiconductor elements, thereby encapsulating the multiple optical semiconductor elements collectively. Specifically, as shown in FIG. 9 , the non-colored layer 71 of the sheet 10 for encapsulating optical semiconductor elements from which the release liner 6 has been peeled off is placed facing the surface of the substrate 2 on which the optical semiconductor elements 3a to 3f are arranged, and the sheet 10 for encapsulating optical semiconductor elements is attached to the surface of the substrate 2 on which the optical semiconductor elements 3a to 3f are arranged, thereby embedding the optical semiconductor elements 3a to 3f in the encapsulating resin layer 7.

The temperature during the lamination is, for example, within a range from room temperature to 110°C. Furthermore, reduced pressure or pressure may be applied during the lamination. This reduces the formation of voids between the encapsulating resin layer and the substrate or optical semiconductor element. Furthermore, in the encapsulation step, it is preferable to laminate the optical semiconductor element encapsulation sheet under reduced pressure and then apply pressure. When reduced pressure is applied, the pressure is, for example, 1 to 100 Pa, and the depressurization time is, for example, 5 to 600 seconds. When pressurized, the pressure is, for example, 0.05 to 0.5 MPa, and the pressurization time is, for example, 5 to 600 seconds.

By appropriately setting the thicknesses of the colored and non-colored layers in the encapsulating resin layer, as well as the temperature and pressure during lamination, it is possible to adjust the conformability of the colored and non-colored layers to the optical semiconductor element in the resulting display, and the thicknesses of the colored and non-colored layers in each of the concave and convex regions in the uneven shape. This allows the resulting display to have a configuration that satisfies the above formulas (1) and (2).

(Radiation irradiation process)
When the encapsulating resin layer comprises a radiation-curable resin layer, the manufacturing method may further comprise a radiation irradiation step of irradiating a laminate comprising the substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element encapsulation sheet that encapsulates the optical semiconductor element with radiation to cure the radiation-curable resin layer and form a cured product layer. As described above, examples of the radiation include electron beams, ultraviolet rays, α rays, β rays, γ rays, and X-rays. Among these, ultraviolet rays are preferred. The temperature during radiation irradiation is, for example, within a range from room temperature to 100°C, and the irradiation time is, for example, 1 minute to 1 hour.

(Dicing process)
The manufacturing method may further include a dicing step of dicing a laminate including the substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element encapsulation sheet that encapsulates the optical semiconductor element. The dicing may be performed on the laminate that has undergone the radiation irradiation step. When the laminate includes a cured product layer formed by curing a radiation-curable resin layer by the radiation irradiation, the dicing step involves dicing and removing the cured product layer of the optical semiconductor element encapsulation sheet and the side edges of the substrate. This allows the surface of the cured product layer, which has been sufficiently cured and has reduced adhesion, to be exposed on the side. The dicing can be performed by a known or conventional method, such as a method using a dicing blade or laser irradiation.

(Tiling process)
The manufacturing method may further include a tiling step of arranging the plurality of display bodies obtained in the dicing step so that they are in contact with each other in a planar direction. In the tiling step, the plurality of stacked bodies obtained in the dicing step are tiled so that they are in contact with each other in a planar direction. In this manner, a single large display body can be manufactured.

The display member of the present invention can be manufactured in the above manner. When the encapsulating resin layer 7 in the sheet 10 for encapsulating optical semiconductor elements does not have a radiation-curable resin layer, the encapsulating resin layer 7 becomes the encapsulating resin layer 4 in the display member 1. On the other hand, when the encapsulating resin layer 7 in the sheet 10 for encapsulating optical semiconductor elements has a radiation-curable resin layer, for example, when the colored layer 72 and the non-colored layer 73 are radiation-curable resin layers, the colored layer 72 and the non-colored layer 73 are cured to form the colored layer 42 and the non-colored layer 43, which become the encapsulating resin layer 4.

DESCRIPTION OF SYMBOLS 1 Display body 2 Substrate 3a to 3f Optical semiconductor element 31 Support 3, 3' Pixel 4 Sealing resin layer 41 Non-colored layer 42 Colored layer 43 Non-colored layer 5 Base material portion 6 Release liner 7 Sealing resin layer 71 Non-colored layer 72 Colored layer 73 Non-colored layer 10 Optical semiconductor element sealing sheet 11 Optical member

Claims (6)

A display comprising a substrate, a plurality of optical semiconductor elements arranged on the substrate, and a sealing resin layer that seals the plurality of optical semiconductor elements,
the plurality of optical semiconductor elements are arranged for each pixel including a plurality of optical semiconductor elements,
the encapsulating resin layer has a colored layer and a non-colored layer in this order from the optical semiconductor element side,
In a vertical cross section with respect to the substrate surface, the cross section passes through the center of gravity of a first optical semiconductor element located at an end of a first pixel and the center of gravity of a second optical semiconductor element located at an end of a second pixel adjacent to the first pixel on the side of the first optical semiconductor element,
The substrate surface is a baseline,
A straight line parallel to the baseline and passing through the center of gravity of the first optical semiconductor element is called Line 1.
A straight line passing through the center of gravity of the first optical semiconductor element and pointing in the front direction at an angle of 15° from the line 1 is called a line 2;
When a straight line passing through the center of gravity of the first optical semiconductor element and in a front direction at an angle of 90° from the line 1 is defined as line 3,
The distance D1 at which the line 2 overlaps with the colored layer and the distance D2 at which the line 3 overlaps with the colored layer satisfy the following formula (1):
A display body, wherein a distance D3 from the surface of the substrate to the front end of the first optical semiconductor element and a thickness D4 of the colored layer at the midpoint between the center of gravity of the first optical semiconductor element and the center of gravity of the second optical semiconductor element satisfy the following formula (2):
D1>D2 (1)
D3>D4 (2) The display element described in claim 1, wherein the sealing resin layer includes a diffusion layer on the optical semiconductor element side of the colored layer. The display according to claim 1 or 2, which comprises a self-luminous display device. The display according to any one of claims 1 to 3 is an image display device. A sheet for sealing a plurality of optical semiconductor elements arranged on a substrate for each pixel including the plurality of optical semiconductor elements,
the sheet includes a sealing resin layer including a colored layer and a non-colored layer,
When the plurality of optical semiconductor elements are encapsulated with the encapsulating resin layer so that the colored layer side faces the optical semiconductor elements, an encapsulating resin layer is formed,
In a vertical cross section with respect to the substrate surface, the cross section passes through the center of gravity of a first optical semiconductor element located at an end of a first pixel and the center of gravity of a second optical semiconductor element located at an end of a second pixel adjacent to the first pixel on the side of the first optical semiconductor element,
The substrate surface is a baseline,
A straight line parallel to the baseline and passing through the center of gravity of the first optical semiconductor element is called Line 1.
A straight line passing through the center of gravity of the first optical semiconductor element and pointing in the front direction at an angle of 15° from the line 1 is called a line 2;
When a straight line passing through the center of gravity of the first optical semiconductor element and in a front direction at an angle of 90° from the line 1 is defined as line 3,
The distance D1 at which the line 2 overlaps with the colored layer and the distance D2 at which the line 3 overlaps with the colored layer may satisfy the following formula (1):
a distance D3 from the surface of the substrate to the front end of the first optical semiconductor element, and a thickness D4 of the colored layer at the midpoint between the center of gravity of the first optical semiconductor element and the center of gravity of the second optical semiconductor element, which satisfy the following formula (2):
D1>D2 (1)
D3>D4 (2) The optical semiconductor element encapsulation sheet according to claim 5, wherein the encapsulating resin layer has a diffusion functional layer on the side of the colored layer opposite the non-colored layer.