JP2018146633A - Display device and line of sight induction sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that improves visibility of the contents of display by attracting the line of sight of a viewer.SOLUTION: A display device comprises: a display body 5a that performs display through vision; a light transmissive base material layer 1 that is arranged opposite to the display body; a plurality of LED dies 3 that are mounted on the light transmissive base material layer; and a wiring pattern 2 that is provided on a surface of the light transmissive base material layer 1 and joined to the LED dies 3. The light transmissive base material layer 1 consists of a plurality of overlappingly-arranged layers 1a, 1b, and 1c, and the plurality of layers have the LED dies mounted thereon and are provided with wiring patterns 2a, 2b, and 2c, respectively. The wiring pattern 2 is obtained by sintering conductive particles with an electromagnetic wave, and the LED dies 3 are joined to the wiring pattern through electromagnetic wave sintering.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a display device that performs visual display.

  As a display body that performs visual display, signs such as roads, license plates such as automobiles, liquid crystal display panels, and the like are widely used. These displays are devised to enhance the visibility of what is seen. For example, in the case of a liquid crystal display panel, visibility is improved by devising the structure and display content, and the road sign has a structure that enhances visibility by illuminating the whole with lights at night. Specifically, Patent Document 1 proposes a structure that prevents the end of the glass substrate from being shined by inclining the peripheral end surface of the liquid crystal display panel and prevents the display quality from being deteriorated. Further, Patent Document 2 discloses a sign illumination apparatus that attaches an illumination device to an upper part of a road sign to irradiate light on the entire display surface, and increases the irradiation luminance of the sign when a disaster occurs.

JP 2013-068895 A JP, 2006-196773, A

  However, in the liquid crystal display panel, since the light intensity of each pixel is small, even if the display contents are devised in order to improve the visibility, it is difficult to avoid a decrease in visibility during backlighting. Further, road signs normally illuminate the entire sign at night, but the display is blurred due to light reflection and scattering, and it is difficult to improve visibility.

  An object of the present invention is to improve the visibility of display contents by attracting the line of sight of what is seen.

  In order to achieve the above object, a display device of the present invention includes a display body that performs visual display, a light-transmitting base material layer that is disposed so as to face the display body, and a light-transmitting base material layer. A plurality of LED dies mounted, and a wiring pattern provided on the surface of the light-transmitting base material layer and bonded to the LED dies. The light transmissive substrate layer is composed of a plurality of layers arranged in an overlapping manner, and an LED die is mounted on each of the plurality of layers, and a wiring pattern is provided. The wiring pattern is obtained by sintering conductive particles with electromagnetic waves, and the LED die is bonded to the wiring pattern by electromagnetic wave sintering.

  The display device of the present invention can enhance the visibility of display contents by attracting the line of sight of what is seen.

It is a front view of the display device of 1st Embodiment, (a) is at the time of light extinction, (b) shows at the time of lighting. FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. Sectional drawing of the example which changed the mounting surface of the LED die of the display device of 1st Embodiment. Sectional drawing which shows another example of arrangement | positioning of the LED die of the display device of 1st Embodiment. (A) And (b) Sectional drawing which shows another example of arrangement | positioning of the LED die of the display device of 1st Embodiment. (A) And (b) Sectional drawing which shows another example of arrangement | positioning of the LED die of the display device of 1st Embodiment. (A) And (b) Sectional drawing which shows the example which sealed the some interlayer of the display device of 1st Embodiment by the intermediate | middle layer. (A)-(d) Sectional drawing which shows the manufacturing process of the wiring pattern of the display device of 1st Embodiment. Sectional drawing which shows the hole of the wiring pattern of 1st Embodiment. It is a front view of the display device of 2nd Embodiment, (a) is at the time of light extinction, (b) shows at the time of lighting. B-B 'sectional drawing of FIG. (A)-(c) The circuit diagram of the LED die and wiring pattern of 2nd Embodiment. FIG. 11 is a B-B ′ cross-sectional view when the arrangement of the LED die of FIG. 10 is shifted in an in-plane direction. Sectional drawing of the display device of 3rd Embodiment.

  A display device according to an embodiment of the present invention will be described with reference to the drawings.

<First Embodiment>
The display device according to the first embodiment includes a display body 5 that performs visual display as shown in FIGS. 1A and 1B and a cross-sectional view in FIG. The light-transmitting substrate layer 1 disposed so as to face the plurality of LED dies 3 mounted on the light-transmitting substrate layer 1, and the LED die 3 provided on the surface of the light-transmitting substrate layer 1. And a wiring pattern 2 bonded to the substrate. The light transmissive substrate layer 1 is composed of a plurality of layers 1a, 1b, and 1c arranged in an overlapping manner, and an LED die 3 (3a, 3b, 3c) is mounted on each of the plurality of layers 1a, 1b, and 1c, A wiring pattern 2 (2a, 2b, 2c) is provided. The wiring pattern 2 is obtained by sintering conductive particles with electromagnetic waves. The LED die 3 is bonded to the wiring pattern 2 by electromagnetic wave sintering. The electromagnetic wave referred to here includes those in the wavelength range of ultraviolet light, visible light, infrared light, and microwave.

  In this way, the wiring pattern 2 (2a, 2b, 2c) is constituted by conductive particles obtained by electromagnetic wave sintering, and the LED die 3 (3a, 3b, 3c) is formed by wiring pattern 2 (2a, 2b, 2c) by electromagnetic wave sintering. ), When the wiring pattern 2 (2a, 2b, 2c) is formed and when the LED die 3 (3a, 3b, 3c) is joined, the electromagnetic wave is focused to the wiring pattern forming portion and the joining portion. Irradiation is sufficient, and it is not necessary to apply heat to the entire surface of the light-transmitting substrate layer 1 (1a, 1b, 1c). For this reason, the heating region at the time of forming and joining the wiring pattern 2 (2a, 2b, 2c) becomes extremely local, about the spot diameter of the focused electromagnetic wave. The local heat can be conducted to the surrounding light-transmitting base material layer 1 and radiated to the air. Therefore, the wiring pattern 2 having a large thickness ratio (aspect ratio) to the width of the wiring can be formed while suppressing the temperature rise of the light transmissive substrate layer 1 (1a, 1b, 1c). Damage to the light-transmitting substrate layer 1 (1a, 1b, 1c) by the wiring pattern 2 (2a, 2b, 2c) having a small area covering the display body 5 and an electrically low resistance. It can be formed without. Further, the LED die 3 (3a, 3b, 3c) can be directly bonded to the wiring pattern 2 (2a, 2b, 2c) of the light transmissive substrate layer 1 (1a, 1b, 1c).

  Further, the wavelength of the electromagnetic wave that can be absorbed by the ink material used for the wiring pattern 2 part is selected, and the light-transmitting base material layer 1 absorbs the electromagnetic wave by using a material that transmits the electromagnetic wave having the wavelength. When the wiring pattern 2 (2a, 2b, 2c) is formed, the wiring pattern 2 (2a, 2b, 2c) is irradiated without focusing the electromagnetic wave, heat is not applied to the entire light-transmitting base material layer 1, It is also possible to heat only the part 2b, 2c).

  Thus, in this embodiment, since it is not necessary to heat the whole surface of the light-transmitting base material layer 1 (1a, 1b, 1c), the light transmission of the light-transmitting base material layer 1 (1a, 1b, 1c). The wiring pattern 2 (2a, 2b, 2c) can be formed without impairing the properties, and the LED die 3 (3a, 3b, 3c) can be directly connected to the wiring pattern 2 (2a, 2b, 2c), respectively. Therefore, the light transmissive substrate layer 1 (1a, 1b, 1c) of the present embodiment has high light transmittance, and when the LED die 3 is lit, the LED die 3 (3a, 3b, The light emitted by 3c) can be emitted, and the line of sight of the viewer can be attracted by the brightness and color of the light emitted by the LED die 3. By arranging such a light-transmitting base material layer 1 so as to face the display body 5, the visibility of the display content 5 a of the display body 5 at the position where the LED die 3 is disposed can be improved, and what is seen The line of sight can be guided to the display content 5a of the display body 5 at the position where the LED die 3 is disposed.

  Moreover, in this embodiment, the LED dies 3a, 3b, and 3c are mounted on the plurality of layers 1a, 1b, and 1c of the light-transmitting base material layer 1 that are arranged in an overlapping manner. When viewed from the front (normal direction), the LED dies 3a, 3b, 3c of the respective layers 1a, 1b, 1c of the light transmissive substrate layer 1 can be seen in a plane, and what is seen is the light transmissive substrate. When the layer 1 is viewed from the oblique direction of the display body 5, the display body 5 becomes difficult to see, but the LED dies 3a, 3b, 3c of the layers 1a, 1b, 1c emit light at different positions in the thickness direction. By seeing, it looks three-dimensional. Thereby, even if it is a case where it sees from the diagonal direction from which the display body 5 becomes difficult to see, the line of sight of what is seen can be attracted and visibility can be improved by guiding to the display content 5a of the display body 5.

  The display body 5 in FIG. 1 is configured to display the display content 5a in a fixed manner, such as a sign, a license plate, or a map. The plurality of LED dies 3 a, 3 b, 3 c are arranged at positions corresponding to the display contents 5 a of the display body 5. Specifically, in the example of FIGS. 1A and 2, the LED dies 3a, 3b, and 3c are arranged at intervals along the outline of the display content 5a and do not overlap each other in the in-plane direction. Are arranged as follows. By arranging the LED dies 3a, 3b and 3c in this way, when the LED dies 3a, 3b and 3c are turned on, the brightness increases along the contour of the fixed display content 5a as shown in FIG. The contour can be emphasized. In addition, when the object to be viewed is viewed from an oblique direction, the LED die 3a, 3b, and 3c are viewed in a three-dimensional manner because the positions of the LED dies 3a, 3b, and 3c are different in the thickness direction. be able to. Further, by selecting the light emission wavelength of the LED die 3, the outline of the display content 5a can be emphasized by a desired light emission color.

  The LED dies 3a, 3b, 3c mounted on each of the plurality of layers 1a, 1b, 1c may have different emission colors for each layer.

  The wiring patterns 2a, 2b, and 2c provided in the multiple layers 1a, 1b, and 1c, respectively, are desirably arranged so as to overlap when the display body 5 is viewed from the front. This is because the area where the wiring patterns 2a, 2b, 2c cover the display body 5 can be reduced.

  In the present embodiment, the LED die 3 (3a, 3b, 3c) can be directly bonded to the wiring pattern 2 (2a, 2b, 2c) on the light transmissive substrate layer 1 (1a, 1b, 1c). Therefore, compared with the case where the LED package in which the LED die 3 is mounted in advance on a submount substrate or the like is mounted on the light-transmitting base material layer 1, the area where the LED package covers the display body 5 is reduced. It can be made thin. Therefore, the area where the LED die 3 covers the display body 5 can be minimized, and the visibility of the display content 5a when turned off can be prevented from being lowered.

  Further, it is desirable that the thickness of the wiring pattern 2 (2a, 2b, 2c) is larger than the width. As a result, the area of the wiring pattern 2 covering the display body 5 can be reduced, and the electrical resistance can be reduced.

  In the configuration of FIG. 2, the light emitting surfaces of the LED dies 3a, 3b, and 3c may be directed to the light-transmitting base material layers 1a, 1b, and 1c on which the LED dies 3a, 3b, and 3c are mounted. It may be directed to the 5 side. When the light emitting surfaces of the LED dies 3a, 3b, 3c are directed to the light transmissive substrate layers 1a, 1b, 1c, the light emitted from the LED dies 3a, 3b, 3c is light transmissive. The light is emitted through the base material layers 1a, 1b, and 1c. When the light emitting surfaces of the LED dies 3a, 3b, and 3c are directed toward the display body 5, the light emitted from the LED dies 3a, 3b, and 3c is reflected by the surface of the display body 5 and is light transmissive. The light is emitted through the base material layers 1a, 1b, and 1c.

  In addition, LED die 3a, 3b, 3c is not restricted to the structure mounted in the surface at the side of the display body 5 of the transparent base material layer 1a, 1b, 1c like FIG. Thus, you may arrange | position on the surface of the outer side (opposite side to the display body 5) of the light transmissive base material layers 1a, 1b, and 1c. Also in this case, the light emitting surfaces of the LED dies 3a, 3b, 3c may be directed to the light-transmitting base material layer 1 side, or may be directed to the display body 5 side. Further, in order to protect the LED die 3, a protective layer can be disposed on the LED die 3 of the light transmissive substrate layer 1.

  Moreover, in this embodiment, since the LED die 3 and the wiring pattern are joined by electromagnetic wave sintering, the joint portion is broken or broken even if strain stress is applied when the light-transmitting base material layer 1 is curved. It is difficult to cause peeling, and durability can be improved.

  Moreover, since the wiring pattern 2 can conduct heat to the light-transmitting substrate layer 1 by efficiently conducting heat generated when the LED die 3 emits light, the heat radiation performance of the LED die 2 can be improved.

  2 and 3 show an example in which all the wiring patterns 2a, 2b and 2c are formed on the mounting surfaces of the LED dies 3a, 3b and 3c of the light-transmitting base material layers 1a, 1b and 1c. However, a part of the wiring patterns 2 a, 2 b, 2 c may be arranged on the surface on the opposite side of the light transmissive substrate layer 1.

  In the configuration of FIG. 2 described above, the LED dies 3a, 3b, and 3c arranged in the layers 1a, 1b, and 1c are arranged so as not to overlap each other in the in-plane direction, but overlap each other as shown in FIG. You may arrange as follows. In this case, the LED dies 3a, 3b, and 3c arranged in the layers 1a, 1b, and 1c may be arranged so as to have a combination of different colors such as red, green, and blue as the respective emission colors. In this case, the positions where all of the LED dies 3a, 3b, 3c are lit are white light, and the positions where one or two of the LED dies 3a, 3b, 3c are lit are the respective single colors. Alternatively, since the colors are mixed, the outline of the display content 5a can be emphasized with different colors.

  Further, the arrangement is not limited to the arrangement shown in FIG. 4, and as shown in FIG. 5A, when the light-transmitting base material layer 1 is composed of only two layers 1 a and 1 b, the light emission colors are LED dies 3 a and 3 b, respectively. It is also possible to arrange red and blue so that they overlap in the in-plane direction. Further, as shown in FIG. 5B, when the light-transmitting base material layer 1 is composed of three layers 1a, 1b, and 1c, the emission colors are green, red, and blue as LED dies 3a, 3b, and 3c, respectively. It is also possible to use one and arrange it so as to be alternately shifted in the in-plane direction.

  Further, as shown in FIGS. 6A and 6B, the arrangement of the LED dies 3 similar to that shown in FIGS. 5A and 5B may be constituted by the LED dies 3 having one emission color.

  As shown in FIGS. 4 and 5A, when the LED dies 3a and 3b (and 3c) having different emission colors overlap in the in-plane direction, the color mixture of the emission colors can be improved. Further, as shown in FIG. 5B, when LED dies 3a, 3b, and 3c having different emission colors are mounted shifted in the in-plane direction by the element outer size of the LED die 3 or more, the light that is lost due to overlapping is lost. It is possible to obtain a light emission color that is small and has good color mixing. Also, as shown in FIG. 6B, when LED dies 3a, 3b, and 3c having the same emission color are mounted with a shift of the element outer size or more, a large luminance can be obtained and a display device with improved visibility can be realized. It becomes.

  Moreover, you may seal the space between the several layers which comprise the transparent base material layer 1 with the intermediate | middle layers 7, such as a liquid or resin. FIGS. 7A and 7B show a configuration example in which the configurations of FIGS. 5A and 5B and FIGS. 6A and 6B are sealed with the intermediate layer 7. The intermediate layer 7 is made of a color (for example, epoxy or silicone) that is transparent to at least light emitted from the LED die 3 and does not interfere with the visual recognition of the display body 5. When the display body 5 emits light, the display body 5 that transmits the luminescent color of the display body 5 is used. When the intermediate layer 7 is disposed, the rigidity of the light-transmitting base material layer 1 can be increased, and when the display body 5 emits light by appropriately designing the refractive index of the intermediate layer 7. The light extraction efficiency can be improved. Further, as the intermediate layer 7, it is also possible to add a material that reflects light, such as titanium oxide or glass, to a light transmitting resin (epoxy, silicone, etc.) to enhance the scattering property of light emitted from the LED die 3. On the contrary, in the region where the light extraction efficiency is desired to be lowered, it is also possible to add a material that blocks light, such as carbon black, to the intermediate layer 7.

  In the configuration described above, the light-transmitting base material layer 1 is desirably a light-transmitting substrate, and the material thereof is glass, PS (polystyrene), PP (polypropylene), PC (polycarbonate), PET ( Polyethylene terephthalate), PEN (polyethylene naphthalate), polyimide, and the like can be used. The thickness of the light transmissive substrate layer 1 is, for example, 25 to 100 μm.

  The wiring pattern 2 is obtained by sintering ink containing conductive particles by electromagnetic waves. As the conductive particles, one or more of conductive metals and conductive metal oxides such as Au, Ag, Cu, Pd, ITO, Ni, Pt, and Fe can be used. In order to efficiently perform the sintering by electromagnetic waves, it is desirable to improve the electromagnetic wave absorption characteristics of the ink containing the conductive particles, and it is desirable that some or all of the conductive particles have a nano-sized shape. The included particle size is, for example, 10 to 150 nm.

  As LED die 3, what emits the light of the desired wavelength suitable for visibility improvement is used.

<Method for Manufacturing First Display Device>
Next, a method for manufacturing the display device of the first embodiment will be described. First, the process of forming the wiring pattern 2 on the light transmissive substrate layer 1 and bonding the LED die 3 will be described with reference to FIGS. Here, an example in which light is used as an electromagnetic wave will be described.

  First, as shown in FIG. 8A, a solution (ink) in which conductive particles and an insulating material are dispersed, or a solution in which conductive particles coated with an insulating material layer are dispersed is used as a light-transmitting group. It is applied to the surface of the material layer 1 in a desired shape. As a coating method, methods such as ink jet, dispensing, flexo, gravure, gravure offset, and screen printing can be used. As a result, a film 21 of conductive particles coated with an insulating material is formed on the surface of the light transmissive substrate layer 1. If necessary, the membrane 21 is heated to evaporate the solvent and dry it. Conductive nanoparticles are dispersed in the film 21, and the periphery of the conductive nanoparticles is covered with an insulating material. Therefore, in this step, the film 21 is non-conductive when the conductive nano particles are completely covered with the insulating material, but has conductivity when there is a portion not covered with the insulating material. That is, the conductivity can be controlled by the type and amount of the insulating material. The film 21 may be applied so as to have the shape of the wiring pattern 2 to be formed, or may be a uniform film. In the case of a uniform film, the region other than the wiring pattern 2 is removed in a subsequent process.

  In order to sinter the fine particles of the formed unsintered film 21, only the wiring portion is locally heated by irradiating electromagnetic waves to sinter the fine particles. As the electromagnetic wave, a pulse wave of light like a flash lamp, a continuous wave like laser light, or an electromagnetic wave with a long wavelength like microwaves can be used. Here, first, as shown in FIG. 8B, the LED die 3 is mounted on the unsintered wiring pattern 2 so that the electrode 31 a contacts the film 21. Next, as shown in FIGS. 8C and 8D, the film 21 is irradiated with the light beam 12 through the light-transmitting base material layer 1. In this method, for example, the formation of the wiring pattern 2 and the connection between the light emitting element 30 and the wiring pattern 2 can be performed simultaneously or successively by irradiation with the light flux 12. Specifically, as shown in FIG. 8C, the light flux 12 is applied to the region between the electrode 31 and the light transmissive substrate layer 1 from the side where the film 21 is not formed on the light transmissive substrate layer 1. Irradiation is performed to photo-sinter the conductive particles of the film 21 to form the wiring pattern 2 to be an electrode connection region. Further, as shown in FIG. 8D, the light flux 12 is irradiated to form another wiring pattern 2. As for the formation order, the wiring pattern 2 to be the electrode connection region of the LED die 3 may be formed after another wiring pattern is formed.

  Further, after the wiring pattern 2 is formed, unsintered conductive particle-containing ink is further applied between the wiring pattern 2 and the electrode 31a, and after the electrode 31a of the LED die 3 is mounted, the light flux 12 is further irradiated. It is also possible to form an electrode connection region.

  In the region of the film 21 irradiated with the light beam 12, the conductive particles absorb the energy of light and the temperature rises. As a result, the conductive particles melt at a temperature lower than the bulk melting point of the material constituting the particles, and with the increase in the temperature of the conductive particles, much of the surrounding insulating material layer evaporates, and some of them Even if it remains, it softens. Therefore, the melted conductive nanoparticles are fused directly with the adjacent particles, or are fused with the adjacent particles through the softened insulating material layer. Thereby, the conductive particles are sintered, and the conductive wiring pattern 2 is formed on the upper surface of the light-transmitting base material layer 1. At this time, the melted conductive particles adhere to the light-transmitting substrate layer 1. In particular, by irradiating the light beam 12 from the surface of the light transmissive substrate layer 1 where the film 21 is not formed, the fixing strength at the interface between the light transmissive substrate layer 1 and the wiring pattern 2 can be increased. .

  As described above, the temperature of the conductive particles in the region of the film 21 that has been irradiated with the light flux 12 rises when irradiated with light, and this heat is used for sintering of the conductive particles, It is conducted to the surrounding film 21 and the light-transmitting base material layer 1 to be radiated. Therefore, only the region of the film 21 that has been irradiated with the light beam 12 or only the region that has been irradiated with the light beam 12 and its neighboring region reaches the temperature at which the conductive particles are sintered, and its outer region. The temperature of the film 21 and the light-transmitting substrate layer 1 do not reach the temperature at which the materials constituting them are melted or altered. That is, in this embodiment, by irradiating only a partial region of the film 21 with the light flux 12, the temperature rise of the light transmissive base material layer 1 can be suppressed, and the light transmissive base material layer 1 can be photo-fired. Deformation such as deformation, distortion and cloudiness due to ligation can be prevented. Moreover, when the light transmissive base material layer 1 is flexible, the flexibility can be maintained.

  In the steps of FIGS. 8C and 8D, it is desirable to form the wiring pattern 2 to be porous. That is, as shown in FIG. 9, adjacent conductive particles are not completely melted and mixed together, but are sintered at the contact interface, and at least a part between the sintered conductive particles. It is desirable to perform photo-sintering at such a temperature that the pores 40a are formed. For example, by using a laser beam as the light beam 12 and irradiating the film 21 with an irradiation intensity that does not melt the light-transmitting base material layer 1 that passes through, the region of the film 21 irradiated with the light beam 12 is irradiated in a short time. Relatively large energy can be input, the conductive particles can be heated and melted and sintered, and the irradiation of the laser light beam 12 is stopped to heat the surrounding film 21 and the light transmissive substrate layer 1. Since it can cool rapidly by conduction, a porous wiring pattern can be formed. In other words, when the film 21 is sintered with the laser beam 12, the porous wiring pattern 2 can be formed by adjusting the irradiation intensity of the beam 12 so that the film 21 has an appropriate temperature. As a specific example, a stretched polyethylene terephthalate (PET) film (melting point: about 250 ° C., heat resistant temperature: about 150 ° C.) is used as the light transmissive substrate layer 1, and the shape of the light transmissive substrate layer 1 is maintained. When the intensity of the laser light beam 12 is adjusted so that the film 21 is irradiated from the back surface of the light transmissive base layer 1 and the conductive particles of the film 21 are sintered, the porous wiring pattern 2 is formed. can do.

  When the wiring pattern 2 is porous, as described above, since the wiring pattern 2 itself has followability (flexibility), even when the flexible light-transmitting substrate layer 1 is deformed, Accordingly, since the wiring pattern 2 follows, the wiring pattern 2 is hardly peeled off from the light-transmitting base material layer 1, and cracks are hardly generated. Therefore, it is possible to provide a flexible substrate that is less likely to be disconnected.

  In the steps of FIGS. 8C and 8D, the shape of the light beam 12 when irradiating the film 21 may be irradiated after being shaped into the shape of the wiring pattern 2 by passing through a mask. Alternatively, the wiring pattern 2 may be drawn by scanning the light beam 12 whose irradiation spot is circular or rectangular.

  Through the above steps, one layer (for example, 1a) of the light transmissive substrate layer 1 on which the wiring pattern 2 and the LED die 3 are mounted can be formed. This is repeated for each of the necessary multiple layers 1a, 1b (and 1c).

  A plurality of layers 1a, 1b (and 1c) of the light-transmitting base material layer 1 are stacked and disposed so as to face the display body 5 as shown in FIG. Can do.

  When the intermediate layer 7 is not disposed and the space between the plurality of layers 1a, 1b, and 1c of the light transmissive base material layer 1 is an air layer, for example, the light transmissive base material layer 1 side and the periphery of the display 5 The parts can be fixed by bonding using an adhesive. Moreover, when it is not desired to interpose an adhesive, it is also possible to fix the light transmissive substrate layer 1 and the display body 5 by a technique such as fitting.

  In the case where a light-transmitting resin is disposed as the intermediate layer 7, the space between the plurality of layers 1 a, 1 b, and 1 c of the light-transmitting base material layer 1 is filled with the light-transmitting resin by a desired method and then bonded. It is possible to use a method in which a plurality of layers are arranged at a predetermined interval, and then a resin is filled through a vacant gap by capillary action, or a resin is filled by a vacuum injection technique. After the injection, the resin is cured by a desired method as necessary. In addition, you may change the material of an intermediate | middle layer for every layer of multiple layers 1a, 1b, 1c.

  In the manufacturing process of FIG. 8, it is of course possible to irradiate the light beam 12 from the surface on the side where the film 21 of the light transmissive substrate layer 1 is provided. In this case, although it cannot be used for the connection portion of the electrode on which the LED die 3 is mounted, other wiring pattern portions can be sintered, so that the electrode connection portion and the wiring pattern forming process can be performed in parallel.

  In addition, the wavelength absorbed by the conductive particles contained in the film 21 is used as the wavelength of the irradiated light beam 12. Irradiation light may be ultraviolet, visible, or infrared light, or may be microwaves. For example, when Ag, Cu, Au, Pd or the like is used as the conductive particles, visible light of 400 to 600 nm can be used.

  When there is a region of the film 21 that is not irradiated with light, sintering does not occur, and therefore, it may be removed in a subsequent step. For example, the film 21 can be removed using an organic solvent or the like. Further, the film 21 can be sintered by additionally irradiating light or heating.

  The ink containing conductive fine particles used in the process of forming the wiring pattern 2 is a solution in which nano-sized conductive particles of 1 μm or less and an insulating material are dispersed, or conductive particles coated with an insulating material layer are dispersed. Solution. As the conductive particles, one or more of conductive metals and conductive metal oxides such as Au, Ag, Cu, Pd, ITO, Ni, Pt, and Fe can be used. The particle diameter of the conductive particles may be only nanoparticles of less than 1 μm, or nanoparticles of less than 1 μm and microparticles of 1 μm or more may be mixed. As the solvent of the solution, an organic solvent or water is used. Additives (polymer component, etc.) that improve dispersibility may be added to the solvent, and resin components (epoxy, silicone, urethane, etc.) may be added to improve the adhesion.

As the insulating material contained at least in the film 21 or the insulating material covering the conductive particles of the film 21, organic materials such as styrene resin, epoxy resin, silicone resin, and acrylic resin, and SiO ₂ , Al One or more of inorganic materials such as ₂ O ₃ and TiO ₂ and organic and inorganic hybrid materials can be used. In addition, the thickness of the insulating material layer covering the conductive particles in the film 21 varies depending on the conductivity control. For example, when the film 21 has an insulating property, the thickness is preferably about 1 nm to 10 μm.

The wiring pattern 2 can be formed to have a size of, for example, 1 μm or more and a thickness of about 1 nm to 50 μm. The electrical resistance value of the wiring pattern 2 is preferably 10 ⁻⁴ Ω / cm ² or less, and particularly preferably a low resistance of the order of 10 ⁻⁶ Ω / cm ² or less.

  In order to protect the LED die 3, it is also possible to provide a protective layer so as to cover the LED die 3 or at a predetermined interval from the LED die 3. It is desirable to use a light transmissive resin material such as an epoxy resin, a silicone resin, a urethane resin, or an acrylic resin as the protective layer.

  Further, the light-transmitting base material layer 1 on which the LED die 3 and the wiring pattern 2 are mounted can be integrated with the display body 5 by bonding and bonding. Examples of the bonding / bonding method include a sheet-like adhesive, a resin material containing an adhesive component such as an epoxy resin, a silicone resin, and a fitting method using screws, caulking, hooks, or the like.

<Second Embodiment>
A display device according to the second embodiment will be described with reference to FIGS. FIGS. 10A and 10B are front views of the display device according to the second embodiment, and FIG. 11 is a cross-sectional view taken along the line BB ′.

  In the present embodiment, the LED dies 3a, 3b, and 3c on the plurality of layers 1a, 1b, and 1c of the light transmissive substrate layer 1 are arranged in a matrix (in a matrix) at intervals. Thereby, the visibility of the display content of the display body 5 at a desired position can be improved by causing the LED dies 3a, 3b, 3c at the desired positions to emit light. Therefore, the display body 5 is not limited to a display that performs fixed display, and displays a two-dimensional display in which pixels are arranged in a matrix and the desired contents are sequentially displayed like a liquid crystal display device or an EL display device. It can be used as the body 5. For example, a car navigation system can be suitably used as the display body 5. It is also possible to use an exhibition of a show window or a showcase (jewels in FIGS. 10A and 10B) as the display body 5a and use the show window or the entire showcase as a display device. In this case, the light transmissive base material layer 1 is disposed on the outer surface or the inner surface of the transparent body in front of the show window or the showcase.

  In order to emit light only from an arbitrary LED die 3 of the plurality of LED dies 3a, 3b, 3c arranged in a matrix of the layers 1a, 1b, 1c of the light transmissive substrate layer 1, the wiring pattern 2 is arranged in the vertical direction. Wiring pattern 2-1 and horizontal wiring pattern 2-2. As an example, in the case of the layer 1a, the LED die 3a is arranged at a position where the vertical wiring pattern 2a-1 and the horizontal wiring pattern 2a-2 intersect or in the vicinity thereof, and currents are individually supplied to the plurality of LED dies 3a. Can be supplied. For example, as shown in FIG. 11, one of the vertical wiring pattern 2a-1 and the horizontal wiring pattern 2a-2 is mainly arranged on one side of the layer 1a, and the other is on the other side of the layer 1a. Place mainly on the surface. The wiring pattern 2a-2 arranged on the surface opposite to the mounting surface of the LED die 3a of the layer 1a is drawn out in the vicinity of the LED die 3a through the via 2a-3 provided in the layer 1a. Connected to the electrode 31a of the LED die 3a. The wiring pattern 2a-1 arranged on the mounting surface side of the LED die 3a of the layer 1a is directly connected to the other electrode 31a of the LED die 3a. Thereby, a matrix circuit as shown in FIG. 12 can be formed, and the LED dies 3a can be individually lit.

  Similarly, the layers 1b and 1c of the light-transmitting base material layer 1 are configured in the same manner to form a matrix circuit as shown in FIGS.

  As shown in FIG. 11, here, the LED dies 3a, 3b, 3c are arranged so as to overlap in the in-plane direction.

  In this manner, the LED dies 3a, 3b, 3c are arranged in a matrix, and the desired LED dies 33a, 3b, 3c can be selectively lit, so that an exhibit (e.g., jewelry) ) The LED die 3 at that position can be turned on so as to guide the line of sight to 5a (FIG. 10 (b)). At this time, since a plurality of light emitting colors of the LED die 3 are arranged at the same point, the light emitting colors of the LED dies 3a, 3b, 3c (in this case, red) By selecting (blue), the visibility can be further improved.

  When the display body 5 is a display body such as a liquid crystal panel that can change the display content every moment, the LED dies 3a, 3b, 3c at positions corresponding to the display to be emphasized in the display content 5a. By turning on, visibility can be improved.

  Further, the LED dies 3a, 3b, and 3c of the multiple layers 1a, 1b, and 1c do not necessarily overlap in the in-plane direction, and the LED dies 3a, 3b, and 3c are mutually in the in-plane direction as shown in FIG. Alternatively, the matrix may be arranged in a shifted manner.

<Third Embodiment>
A display device according to a third embodiment will be described with reference to FIG. FIG. 14 is a cross-sectional view of the display device of the third embodiment.

  The display device according to the third embodiment uses a mirror including a reflective surface 50 and a transparent body 51 that supports the reflective surface 50 as the display body 5. Note that the transparent body 51 is not necessarily provided. A plurality of light-transmitting substrate layers 1 including the plurality of LED dies 3a of the first embodiment or the matrix-like LED dies 3a, 3b, 3c of the second embodiment facing the mirror. A plurality of light-transmitting base material layers 1 provided are arranged.

  In addition, the reflecting surface 50 can be configured to have not only a characteristic having complete reflection but also a characteristic of a half mirror.

  In the display device having such a structure, the LED die 3 emits light so as to correspond to the position at which the mirror image is projected, thereby enhancing the visibility of the mirror image or emphasizing a specific region of the image. Thus, the line of sight can be guided. In particular, the LED dies 3a, 3b, etc., such as the multiple layers 1a, 1b, etc., emit multiple rays at different positions in the thickness direction, so that the line of sight can be attracted by the three-dimensional emission, thereby improving visibility. In addition, it is possible to easily recognize the position of the mirror, and it is possible to prevent a collision or a collision with an object.

  For example, the human face is projected on a mirror (display body) 5 and the LED dies 3a and 3b in the region of the image of a specific part (for example, forehead) are caused to emit light so that the viewer's line of sight can be specified. Can be guided to.

  Further, for example, by arranging the light transmissive base material layer 1 in which the LED dies 3a, 3b and the like are arranged on the reflection mirror portion and the cover of the rear combination lamp (tail lamp) for a vehicle incorporating the reflection mirror, the display of the present embodiment The device can be configured. In this rear combination lamp, for example, when a sudden brake is applied, the LED die 3 is caused to emit light, so that not only the point light source of the LED die 3 but also the point light source generated by the reflection of the mirror surface, than in the case of normal braking. The display can be emphasized, and the effect that the visibility of the driver of the following vehicle can be improved can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Light transmissive base material layer, 1a, 1b, 1c ... Layer, 2 (2a, 2b, 2c) ... Wiring pattern, 3 (3a, 3b, 3c) ... LED die, 5 ... Display body, 5a ... Display content , 7 ... Intermediate layer

Claims (14)

A display body for visual display;
A light-transmitting base material layer disposed to face the display body;
A plurality of LED dies mounted on the light transmissive substrate layer;
Provided on the surface of the light transmissive substrate layer, and having a wiring pattern bonded to the LED die,
The light-transmitting substrate layer is composed of a plurality of layers arranged in an overlapping manner, and each of the plurality of layers is provided with the LED pattern and the wiring pattern,
The display device is characterized in that the wiring pattern is obtained by sintering conductive particles by electromagnetic waves, and the LED die is bonded to the wiring pattern by electromagnetic wave sintering.   The display device according to claim 1, wherein the wiring patterns provided in each of the plurality of layers are arranged so as to overlap when the display body is viewed from the front.   3. The display device according to claim 1, wherein the LED die mounted on each of the plurality of layers has a different emission color for each layer.   The display device according to claim 3, wherein the LED die mounted for each layer is arranged so as to overlap when the display body is viewed from the front. The display device according to any one of claims 1 to 4, wherein the display body is configured to display display content in a fixed manner.
The plurality of LED dies are arranged at positions corresponding to display contents of the display body.   5. The display device according to claim 1, wherein the plurality of LED dies are arranged vertically and horizontally with a space therebetween.   7. The display device according to claim 6, wherein the wiring patterns for each layer include a vertical wiring pattern and a horizontal wiring pattern, respectively, and the vertical wiring pattern and the horizontal wiring pattern. The display device is characterized in that the LED die is arranged at a position where the LED intersects or in the vicinity thereof, and current can be individually supplied to the plurality of LED dies.   The display device according to claim 7, wherein one of the vertical wiring pattern and the horizontal wiring pattern is arranged on one surface of the layer and the other is arranged on the other surface of the layer. A display device characterized by having   9. The display device according to claim 1, wherein the wiring pattern has a thickness larger than a width.   10. The display device according to claim 1, wherein the wiring pattern is directly fixed to a surface of the plurality of layers constituting the light-transmitting base material layer. 11. Display device.   11. The display device according to claim 1, wherein the LED die is mounted on the light-transmitting base material layer with a light emitting surface facing away from the display body. Display device characterized by.   12. The display device according to claim 1, wherein the LED die is mounted on the light-transmitting base material layer with a light emitting surface facing the display body. Display device.   The display device according to any one of claims 1 to 12, wherein the display body is one of a sign, a license plate, a two-dimensional display, a mirror, and an exhibit of a show window or a showcase. A display device characterized by being. A sheet that is arranged so as to overlap a display body that performs visual display, and guides the line of sight of what is seen,
A light-transmitting base material layer disposed to face the display body;
A plurality of LED dies mounted on the light transmissive substrate layer;
Provided on the surface of the light transmissive substrate layer, and having a wiring pattern bonded to the LED die,
The light-transmitting substrate layer is composed of a plurality of layers arranged in an overlapping manner, and each of the plurality of layers is provided with the LED pattern and the wiring pattern,
The line-of-sight induction sheet, wherein the wiring pattern is obtained by sintering conductive particles by light, and the LED die is bonded to the wiring pattern by light sintering.

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