JP6963183B2 - Manufacturing method of light emitting module - Google Patents

Description

The present disclosure relates to a method for manufacturing a light emitting module.

A light emitting device using a light emitting element such as a light emitting diode is widely used as a backlight of a liquid crystal display or various light sources such as a display.
For example, the light source device disclosed in Patent Document 1 is composed of a plurality of light emitting elements mounted on a mounting substrate, a hemispherical lens member that seals each of the plurality of light emitting elements, and a light emitting element arranged on the hemispherical lens member. It is provided with a diffusing member to which the light of the above is incident.

JP-A-2015-323373

However, in a light source device such as Patent Document 1, it is necessary to make the distance between the mounting substrate and the diffuser plate larger than the thickness of the lens member, and there is a possibility that sufficient thinning cannot be achieved.

Therefore, an object of the present disclosure is to provide a light emitting module including a light guide plate and a light emitting element, which can be made thinner.

The method for manufacturing a light emitting module according to the present disclosure includes the following configurations.
The method for manufacturing a light emitting module according to the present disclosure includes the following configurations. A step of preparing a light emitting element including a semiconductor laminate and an electrode, and a step of preparing a light guide plate including a first main surface to be a light emitting surface and a second main surface opposite to the first main surface. A step of arranging a plurality of joining members on the second main surface of the light guide plate, a step of aligning the heights of the upper surfaces of the plurality of joining members, and a step of placing a light emitting element on each joining member with the electrodes facing up. A step of arranging a coating member for covering a light emitting element including an electrode, a step of removing the covering member until the electrode is exposed, and a step of forming a conductive member for electrically connecting a plurality of light emitting elements. A method of manufacturing a light emitting module including.

This makes it possible to provide a light emitting module including a light guide plate and a light emitting element, which can be made thinner.

It is a schematic plan view of the light emitting module which concerns on embodiment. It is a partially enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is a partially enlarged schematic plan view and a partially enlarged schematic side view which shows an example of the optical function part and the positioning part of the light guide plate which concerns on embodiment. It is a partially enlarged schematic cross-sectional view of the modification of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view of the modification of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view of the modification of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is a partially enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, terms indicating a specific direction or position (for example, "upper", "lower", and other terms including those terms) are used as necessary, but the use of these terms is used. This is for facilitating the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Further, the parts having the same reference numerals appearing in a plurality of drawings indicate the same or equivalent parts or members. In addition, the same name shall be used for each member even if the state, shape, etc. are different before and after curing, before and after cutting, and the like.

Further, the embodiments shown below exemplify a light emitting module for embodying the technical idea of the present invention, and do not limit the present invention to the following. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention to the specific description, but are exemplified. It was intended. Further, the contents described in one embodiment and the embodiment can be applied to other embodiments and the examples. In addition, the size and positional relationship of the members shown in the drawings may be exaggerated in order to clarify the explanation.

(Light emitting module)
The configuration of the light emitting module of this embodiment is shown in FIGS. 1A and 1B.
FIG. 1A is a schematic plan view of the light emitting module 100 according to the present embodiment. FIG. 1B is a partially enlarged schematic cross-sectional view showing a light emitting module 100 according to the present embodiment. FIG. 1C is a partially enlarged schematic plan view and a partially enlarged schematic cross-sectional view showing an example of the optical functional unit 111 of the first main surface 11 of the light guide plate 10 and the positioning unit 121 of the second main surface 12 according to the embodiment. Is.

The light emitting module 100 includes a light guide plate 10 and a plurality of light emitting elements 30 joined to the plurality of light guide plates 10. The plurality of light emitting elements 30 are arranged in a matrix on the second main surface 12 of the light guide plate 10. The light guide plate 10 of the light emitting module 100 includes a first main surface 11 that serves as a light emitting surface, and a second main surface 12 that is opposite to the first main surface 11. The light emitting element 30 is joined to the second main surface 12 by the joining member 20. In the example shown in FIG. 1B, the light guide plate 10 is provided with a recess as a positioning portion 121 on the second main surface 12, and a wavelength conversion member 60 is further provided inside the recess.

The positioning portion (recess) 121 and the wavelength conversion member 60 may be omitted. For example, in the light emitting module 100A shown in FIG. 1D, the second main surface 12A of the light guide plate 10A is a flat surface without a recess. Therefore, the side surface of the wavelength conversion member 60 is covered with the covering member 40A. Further, in the light emitting module 100B shown in FIG. 1E, the light guide plate 10A does not have a recess as in the example shown in FIG. 1D, the second main surface 12A is flat, and further, the wavelength conversion member is not provided. Therefore, only the joining member 20 exists between the light emitting element 30 and the light guide plate 10A.

Such a light emitting module can be obtained by a manufacturing method including the following steps.
The manufacturing method of the light emitting module is
(1) Step of preparing a light emitting element including a semiconductor laminate and an electrode (2) Preparing a light guide plate including a first main surface to be a light emitting surface and a second main surface opposite to the first main surface. (3) A process of arranging a plurality of joining members on the second main surface of the light guide plate (4) A step of aligning the heights of the upper surfaces of the plurality of joining members (5) An electrode is placed on each joining member. (6) A step of arranging a covering member for covering the light emitting element including the electrode (7) A step of removing the covering member until the electrode is exposed (8) Electrically connecting a plurality of light emitting elements A step of forming a conductive member to be connected to is provided.

Since the light emitting module according to the present disclosure has a light emitting element bonded to the light guide plate, it can be made thinner. Further, since the light emitting element is mounted on the light guide plate and adhered to each other, the position shift between the light emitting element and the light guide plate is less likely to occur as compared with the case where the light emitting element is mounted on the substrate and the light guide plate is combined. This makes it possible to obtain a light emitting module having good optical characteristics. Further, by making the heights of the joining members uniform, it is possible to reduce the height variation of the light emitting element. Therefore, even when the light guide plate is warped, the electrodes can be reliably exposed in the step of exposing the electrodes by removing the covering member.

Each step of the method for manufacturing the light emitting module 100 according to the present embodiment will be described in detail below. 2A to 2K show an example of the method for manufacturing the light emitting module of the present embodiment.

(1) Step of Preparing a Light Emitting Element with a Semiconductor Laminated Body and Electrodes The light emitting element 30 is a light source of a light emitting module 100. A plurality of light emitting elements 30 are joined to one light guide plate 10. Necessary light emitting elements are prepared according to the size of the light emitting module 100 and the target optical characteristics. The light emitting element can be prepared by undergoing a part or all of the manufacturing process, such as through a process such as semiconductor growth, or may be prepared by purchase or the like.

(2) Step of preparing a light guide plate including a first main surface serving as a light emitting surface and a second main surface opposite to the first main surface As shown in FIG. 2A, the light guide plate 10 is prepared. The light guide plate 10 is a member that spreads the light from the light emitting element 30 in a planar shape, and has a substantially plate shape including a first main surface 11 which is a light extraction surface and a second main surface 12 located on the opposite side thereof. It is a member of.

As shown in FIG. 2A, the light guide plate 10 may include an optical function unit 111 recessed in a conical shape on the first main surface 11. Further, the light guide plate 10 may be provided with a recess (positioning portion) 121 having a substantially quadrangular opening on the second main surface 12.

When a diffusion member or a wavelength conversion member is provided, as shown in FIG. 2B, a step of arranging the diffusion member 60 in the recess 121 of the second main surface 12 of the light guide plate 10 is provided. The diffusion member 60 is a member that diffuses the light from the light emitting element. The diffusion member 60 is, for example, a mixed material of a light diffusing substance and a resin material. The diffusing member 60 may be a wavelength conversion member including a phosphor that absorbs light from a light emitting element and converts it into light having a different wavelength.

As a method of arranging the diffusion member 60, for example, a method of arranging the material of the liquid diffusion member on the second main surface 12 or in the recess 121 provided in the second main surface 12 by potting, printing, spraying or the like can be mentioned. Be done. In this case, if there is an extra material for the diffusion member that did not enter the recess 121, the material for the diffusion member outside the recess 121 may be removed from the second main surface 12. In the example shown in FIG. 2B, the material of the diffusion member arranged on the second main surface 12 is arranged in the recess 121 by using the squeegee 80. Then, by curing the material of the liquid diffusion member, as shown in FIG. 2B, the diffusion member 60 is formed in each of the positioning portions 121.

Alternatively, a method may be used in which a molded product of the diffusion member 60 molded into a plate shape or the like is prepared in advance and placed on the positioning portion 121. Examples of the method for forming the molded product of the diffusion member 60 include a method of individualizing a large-area plate-shaped or sheet-shaped diffusion member by cutting, punching, or the like. Alternatively, a molded product of the small piece diffusion member 60 can be formed by a method such as injection molding, transfer molding, or compression molding using a mold or the like. The molded product of the diffusion member 60 can be adhered to the inside of the positioning portion (recess) 121 or the second main surface 12 of the light guide plate 10 by using an adhesive or the like.

(3) Step of arranging a plurality of joining members on the second main surface of the light guide plate Next, as shown in FIG. 2C, a liquid joining member 20 is applied onto each of the diffusion members 60. The joining member 20 can be applied by a method such as potting, transfer, or printing. FIG. 2C illustrates a case where the joining member 20 is applied by potting using the dispense nozzle 81, and the upper surface 21 of the applied joining member 20 has a convex curved surface shape.

(4) Step of Aligning the Heights of the Upper Surfaces of a plurality of Joining Members Next, as shown in FIG. 2D, the heights of the upper surfaces of the plurality of joining members are aligned. Here, the joining member is ground using a grinding member 82 such as a grindstone. As a result, as shown in FIG. 2E, the heights of the upper surfaces 21 of the joining members 20 are made uniform. The "height" here does not refer to the thickness of the joining member 20, but to the position of the upper surface 21. Further, the height of the upper surface thereof may be made uniform by pressing the joining member 20.

(5) Step of placing the light emitting element on each joining member with the electrode facing up Next, as shown in FIG. 2F, the light emitting element 30 is placed on the upper surface 21 of each joining member 20. At this time, the light emitting element 30 is placed on the electrode 32 (electrode forming surface 312). That is, the main light emitting surface 311 is placed so as to face the upper surface 21 of the joining member 20. After that, the joining member is cured, and the light emitting element 30 and the light guide plate 10 are joined.

The plurality of light emitting elements 30 are arranged two-dimensionally in the plan view of the light guide plate 10. Preferably, as shown in FIG. 1A, the plurality of light emitting elements 30 are arranged two-dimensionally along two orthogonal directions, that is, the x direction (horizontal direction) and the y direction (longitudinal direction). The arrangement pitch in the x direction and the arrangement pitch in the y direction of the plurality of light emitting elements 30 arranged so as to correspond to the plurality of optical function units 111 may be the same or different. Also, the two directions of the array do not have to be orthogonal. Further, the arrangement pitch in the x-direction or the y-direction is not limited to equal intervals, and may be unequal intervals. For example, the light emitting elements 30 may be arranged so that the distance between the light guide plate 10 is widened from the center to the periphery. The pitch between the light emitting elements 30 is the distance between the optical axes of the light emitting elements 30. The pitch between the light emitting elements 30 can be, for example, about 0.05 mm to 20 mm, preferably about 1 mm to 10 mm.

(6) Step of Arranging the Covering Member that Covers the Light Emitting Element Containing the Electrode Next, as shown in FIG. 2G, the covering member 40 that covers the second main surface 12 of the light guide plate 10 and the plurality of light emitting elements 30 is formed. Form. The covering member 40 can be formed by a method such as transfer molding, potting, printing, or spraying. At this time, the covering member 40 is thickly formed so as to completely cover the upper surface of the electrode 32 of the light emitting element 30.

(7) Step of Removing Covering Member Until The Electrode Is Exposed Next, as shown in FIG. 2H, a part of the covering member 40 is ground to expose the electrode 32 of the light emitting element 30. As a grinding method, the covering member 40 is ground in a planar shape using a grinding member such as a grindstone. Since the joining member 20 is ground to have the same height, the electrodes 32 of the plurality of light emitting elements 30 are exposed.

(8) Step of Forming a Conductive Member for Electrically Connecting a plurality of Light Emitting Elements Next, as shown in FIG. 2I, the conductive member 50 is formed on substantially the entire surface of the electrode 32 of the light emitting element 30 and the covering member 40. Form a metal film. The metal film may have, for example, a laminated structure in which Cu / Ni / Au are laminated in this order from the light guide plate 10 side. Examples of the method for forming the metal film include sputtering, plating, and the like, and it is preferable to form the metal film by sputtering.

Next, as shown in FIG. 2J, the metal film is irradiated with laser light, and patterning is performed by laser ablation to remove the metal film of the irradiated portion to form the conductive member 50.

Next, as shown in FIG. 2K, the conductive member 50 and the wiring layer 72 of the wiring board 70 prepared separately are crimped and joined with an adhesive sheet in between. At this time, the conductive member 50 and the wiring layer 72 are electrically connected by partially melting the conductive material filled in a part (for example, via) of the wiring layer 72 by pressurization and heating.
In this way, the light emitting module 100 of the present embodiment can be obtained.

The plurality of light emitting elements 30 may be wired so as to be driven independently of each other. Further, the light guide plate 10 is divided into a plurality of ranges, and the plurality of light emitting elements 30 mounted in one range are grouped into one group, and the plurality of light emitting elements 30 in one group are electrically connected in series or in parallel. It may be connected to the same circuit by connecting to, and a plurality of such light emitting element groups may be provided. By performing such grouping, it is possible to obtain a light emitting module capable of local dimming.

One of the light emitting modules 100 of the present embodiment may be used as a backlight of one liquid crystal display device. Further, a plurality of light emitting modules 100 may be arranged side by side and used as a backlight of one liquid crystal display device. By making a plurality of small light emitting modules 100 and inspecting each of them, the yield can be improved as compared with the case of making a light emitting module 100 having a large number of light emitting elements 30 mounted large.

One light emitting module 100 may be bonded to one wiring board 70. Further, a plurality of light emitting modules 100 may be joined to one wiring board 70. As a result, the electrical connection terminals (for example, connectors) to the outside can be integrated (that is, it is not necessary to prepare each light emitting module), so that the structure of the liquid crystal display device can be simplified.

Further, a plurality of one wiring board 70 to which the plurality of light emitting modules 100 are joined may be arranged side by side to serve as a backlight of one liquid crystal display device. At this time, for example, a plurality of wiring boards 70 can be placed on a frame or the like and each can be connected to an external power source by using a connector or the like.

Each member constituting the light emitting module will be described in detail below.

(Light emitting element)
As the light emitting element 30, a known semiconductor light emitting element can be used. In this embodiment, a light emitting diode is exemplified as the light emitting element 30. The light emitting element has a main light emitting surface 311 that mainly takes out light emission, and a pair of electrodes 32 on an electrode forming surface 312 on the opposite side of the main light emitting surface 311. The pair of electrodes 32 are arranged to face the wiring board 70 described later, and are optionally electrically connected to the wiring layer 72 of the wiring board 70 via a conductive member 50 or the like.

The light emitting element 30 includes, for example, a semiconductor laminate including a translucent substrate such as sapphire and a semiconductor layer laminated on the translucent substrate. The semiconductor laminate 31 includes a light emitting layer, an n-type semiconductor layer and a p-type semiconductor layer sandwiching the light emitting layer, and the n-side electrode and the p-side electrode are electrically connected to the n-type semiconductor layer and the p-type semiconductor layer, respectively. Will be done. In the light emitting element 30, for example, a main light emitting surface 311 provided with a translucent substrate is arranged so as to face the light guide plate, and the light emitting element 30 has a pair of electrodes 32 on an electrode forming surface 312 opposite to the main light emitting surface 311.

The light emitting element 30, an element that emits light of an arbitrary wavelength can be selected. For example, blue, as the device for emitting green light, a nitride-based semiconductor _{(In x Al y Ga 1-} x-y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) light emitting device using or GaP Can be used. Further, as the element that emits red light, a light emitting element containing a semiconductor such as GaAlAs or AlInGaP can be used. Further, a semiconductor light emitting device made of a material other than these can also be used. Various emission wavelengths can be selected depending on the material of the semiconductor layer and its mixed crystalliteness. The composition, emission color, size, number, etc. of the light emitting element to be used may be appropriately selected according to the purpose. When the light emitting module 100 includes a wavelength conversion member, the light emitting element 30 is a nitride semiconductor (In _x Al _y Ga _1-xy N) capable of emitting short wavelength light capable of efficiently exciting the wavelength conversion member. , 0 ≦ X, 0 ≦ Y, X + Y ≦ 1).

The size of the light emitting element 30 is, for example, preferably 1000 μm or less in the vertical and horizontal dimensions in a plan view, more preferably 500 μm or less in the vertical and horizontal dimensions, and further preferably 200 μm or less in the vertical and horizontal dimensions. Is. When such a light emitting element is used, a high-definition image can be realized when the liquid crystal display device is locally dimmed.

(Light guide plate)
The light guide plate 10 is a translucent plate-shaped member that emits light in a planar manner when light from a light emitting element is incident on the light guide plate 10. The light guide plate 10 includes a first main surface 11 that serves as a light emitting surface, and a second main surface 12 that is opposite to the first main surface 11.

The size of the light guide plate 10 can be, for example, about 1 cm to 200 cm on a side, and is preferably about 3 cm to 30 cm. The thickness can be about 0.1 mm to 5 mm, preferably 0.5 mm to 3 mm. The "thickness" here means, for example, the thickness when it is assumed that the first main surface 11 and the second main surface 12 have recesses and protrusions, which are not present. ..
The planar shape of the light guide plate 1 can be, for example, a substantially rectangular shape, a substantially circular shape, or the like.

As the material of the light guide plate 10, a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate and polyester, a resin material such as a thermosetting resin such as epoxy and silicone, and an optically transparent material such as glass are used. be able to. In particular, a thermoplastic resin material is preferable because it can be efficiently produced by injection molding. Of these, polycarbonate, which has high transparency and is inexpensive, is preferable. In the manufacturing method of the light emitting device of the present embodiment in which the wiring board is attached after the light emitting element 30 is bonded to the light guide plate 10, the step of applying a high temperature such as solder reflow can be omitted, so that the light emitting device is thermoplastic like polycarbonate. Even a material having low heat resistance can be used.

The light guide plate 10 can be molded by, for example, injection molding, transfer molding, thermal transfer, or the like. When the light guide plate 10 includes an optical function unit 111 and a positioning unit 121, these can also be collectively formed by a mold. As a result, it is possible to reduce the molding position deviation between the optical function unit 111 and the positioning unit 121.

The light guide plate 10 may be formed of a single layer, or may be formed by stacking a plurality of translucent layers. When a plurality of translucent layers are laminated, layers having different refractive indexes, such as an air layer, may be provided between arbitrary layers. As a result, it becomes easier to diffuse the light, and it is possible to obtain a light emitting module with reduced brightness unevenness. Such a configuration can be realized, for example, by providing a spacer between any plurality of translucent layers to separate them and providing an air layer.

(Optical function unit)
The light guide plate 10 may be provided with an optical function unit 111 on the first main surface 11 side. The optical function unit 111 can have, for example, a function of spreading light in the plane of the light guide plate 10. For example, a material having a refractive index different from that of the light guide plate 10 is provided. Specifically, the optical function unit 111 is a recess such as a cone, a quadrangular pyramid, or a hexagonal pyramid provided on the first main surface 11 side, and has a refractive index different from that of the light guide plate 10 ( For example, one that reflects the light emitted at the interface between the air) and the inclined surface of the recess in the lateral direction of the light emitting element 30 can be used. Further, the optical function unit can be a truncated cone or a polygonal pyramid such as a quadrangular pyramid. In the light emitting module 100C shown in FIG. 1F, the light guide plate 10B includes an optical functional unit 111A of a truncated cone, and such an optical functional unit 111A is trapezoidal in cross-sectional view. In the case of the cone-shaped optical functional unit 111A, for example, a light-reflecting material (for example, a reflective film such as metal or a white resin) may be provided in a recess having an inclined surface. The inclined surface of the optical function unit 111 may be a straight line or a curved line in a cross-sectional view.
As will be described later, the optical function unit 111 is preferably provided at a position corresponding to each light emitting element 30, that is, at a position opposite to the light emitting element 30 arranged on the second main surface 12 side. In particular, it is preferable that the optical axis of the light emitting element 30 and the optical axis of the optical functional unit 111 substantially coincide with each other.

The size of the optical function unit 111 can be appropriately set. The optical function unit 111 shown in FIG. 1B is a conical recess having a circular opening on the first main surface 11, and shows an example in which the diameter of the opening is larger than that of the wavelength conversion member 60.

(Positioning part (recess))
The light guide plate 10 may be provided with a positioning portion 121 on the second main surface 12 side. The positioning portion 121 is a target portion at a position where the light emitting element 30 is arranged, and may be, for example, a concave portion, a convex portion, a groove, or the like as shown in FIG. 1B or the like.
The size of the positioning unit 121 in a plan view can be, for example, 0.05 mm to 10 mm, preferably 0.1 mm to 1 mm. The depth can be 0.05 mm to 4 mm, preferably 0.1 mm to 1 mm. The distance between the optical function unit 111 and the positioning unit 121 can be appropriately set within a range in which the optical function unit 111 and the positioning unit 121 are separated from each other.

The plan-view shape of the positioning unit 121 can be, for example, a substantially rectangular shape or a substantially circular shape, and can be selected depending on the arrangement pitch of the positioning unit and the like. When the arrangement pitch of the positioning portions (the distance between the two closest positioning portions) is substantially equal, a substantially circular shape or a substantially square shape is preferable. Above all, by making it substantially circular, the light from the light emitting element 30 can be satisfactorily spread.

(Diffusion member)
The diffusing member arranged on the second main surface side of the light guide plate is a member containing a light diffusing substance that diffuses the light from the light emitting element 30. Further, the diffusion member may be a wavelength conversion member containing a phosphor that converts the wavelength of light from the light emitting element 30 into light having a different wavelength. Further, it may be a diffusion member in which a phosphor-containing layer containing a phosphor and a phosphor-free layer containing no phosphor are laminated. Alternatively, it may be a diffusion member in which a phosphor-containing layer containing a phosphor and a diffusion layer containing a light diffusing substance that does not convert a wavelength are laminated.

The diffusion member and the wavelength conversion member are provided between the light emitting element 30 and the light guide plate 10, and are arranged on the second main surface 12 side of the light guide plate 10. The diffusing unit and the wavelength conversion member diffuse and equalize the light emitted from the light emitting element 30. As shown in FIG. 1B, the diffusion member (wavelength conversion member) can be arranged in the positioning portion (recess) 121 of the light guide plate 10. Alternatively, as shown in FIG. 1D, it may be arranged on the second main surface 12 of the flat light guide plate 10 and provided so as to project from the second main surface 12.

The size and shape of the diffusion member 60 can be, for example, about the same as the recess when the positioning portion is provided with the recess. Further, the height of the diffusion member 60 is preferably about the same as the depth of the recess when the positioning portion is provided.

The light guide plate 10 may have a process for causing light diffusion, reflection, or the like to a portion other than the optical functional unit 111. For example, a fine unevenness may be provided in a portion separated from the optical functional unit 111, or a rough surface may be provided. This makes it possible to further diffuse the light and reduce the uneven brightness.

The diffusion member 60 is preferably made of a material having a higher refractive index than the material of the light guide plate 10. For example, as the material of the base material, an epoxy resin, a silicone resin, a resin in which these are mixed, or a translucent material such as glass can be used. From the viewpoint of light resistance and moldability of the diffusion member 60, it is beneficial to select a silicone resin as the base material of the diffusion member 60.

Examples of the light diffusing substance include fine particles such as _{SiO 2} , TiO ₂ , Al ₂ O _{3, and ZnO.}

The diffusion member 60 can include a particulate phosphor as a wavelength conversion substance. Examples of the phosphor include a fluoride-based phosphor such as a YAG-based phosphor, a β-sialone phosphor, and a KSF-based phosphor. One diffusion member 60 may contain one or more types of phosphors. The plurality of types of phosphors may be used in a mixed manner, or may be used in a laminated manner. For example, a light emitting element 30 that emits blue light is used, and the phosphor includes a β-sialon phosphor that emits green light and a fluoride phosphor such as a KSF phosphor that emits red light. Can be done. By using these two types of phosphors, the color reproduction range of the light emitting module can be expanded. Further, the phosphor may be a quantum dot.

When the diffusing member 60 contains a phosphor, the phosphor may be arranged in any manner inside the diffuser 60. For example, it may be distributed substantially uniformly, or may be unevenly distributed in a part.

(Joining member)
The joining member 20 has a role of propagating the light emitted from the light emitting element 30 to the light guide plate 10. The joining member 20 is a member that directly or indirectly joins the light emitting element 30 and the light guide plate 10. Indirectly joining means that the diffusion member or wavelength conversion member 60 arranged on the light guide plate 10 and the light emitting element 30 are joined by the joining member 20.

The joining member 20 is translucent and transmits 60% or more, preferably 90% or more of the light emitted from the light emitting element 30. Therefore, the joining member 20 can include a diffusion member or the like, and may be composed of only a translucent resin material that does not include the diffusion member or the like.

The joining member 20 may cover the side surface of the light emitting element 30 (the surface connecting the main light emitting surface 311 and the electrode forming surface 312). As a result, the light emitted in the side surface direction of the light emitting element 30 can be efficiently taken out into the joining member 20, and the light emitting efficiency of the light emitting module 100 can be improved.

As the material of the joining member 20, a translucent thermosetting resin material such as an epoxy resin or a silicone resin can be used.

(Coating member)
The covering member 40 covers the side surfaces of the plurality of light emitting elements 30, the second main surface 12 of the light guide plate 10, and the side surface of the joining member 20. Thereby, the light emitting element 30 and the light guide plate 10 can be reinforced. Further, the covering member 40 is preferably a light reflecting member. By using the covering member 40 as a light reflecting member, the light emitted from the light emitting element 30 can be efficiently taken into the light guide plate 10. As shown in FIG. 1D, when the diffusion member (wavelength conversion member) 60 is provided on the second main surface of the light guide plate 10, and the side surface or the like of the diffusion member 60 is exposed from the light guide plate 10. It is preferable that the exposed portion is also covered with the covering member 40.

The coating member 40 of the light-reflecting member has a reflectance of 60% or more, preferably 90% or more, with respect to the light emitted from the light emitting element 30. The material of the coating member 40 of the light-reflecting member is preferably a resin material containing a white pigment or the like. In particular, a silicone resin containing titanium oxide is preferable. As a result, the light emitting module 100 can be made inexpensive by using a large amount of an inexpensive raw material such as titanium oxide as a material used in a relatively large amount to cover one surface of the light guide plate 10.

(Conductive member)
The light emitting module 100 may be provided with a conductive member 50 that is electrically connected to the electrodes 32 of the plurality of light emitting elements 30. The conductive member 50 is arranged so as to cover the lower surface of the covering member 40 and the lower surface of the electrode 32. By providing the conductive member 50, for example, a plurality of light emitting elements 30 can be electrically connected to each other, and a circuit necessary for local dimming of a liquid crystal display device or the like can be easily formed.

(Wiring board)
The light emitting module 100 may have a wiring board 70 as shown in FIG. 2K. The wiring board 70 is a board including an insulating base material 71, a wiring layer 72 electrically connected to a plurality of light emitting elements 30, and the like. By providing the wiring board 70, complicated wiring required for local dimming or the like can be easily formed. In this wiring board 70, after the light emitting element 30 is mounted on the light guide plate 10 and the covering member 40 and the conductive member 50 are arbitrarily formed, the wiring layer 72 of the wiring board 70 prepared separately and the conductive member 50 are joined. It can be formed by doing. Further, when the conductive member 50 to be connected to the light emitting element 30 is provided, the conductive member 50 has a shape larger than the planar shape of the electrode 32 of the light emitting element 30, so that the wiring board 70 and the light emitting element 30 are electrically connected. Joining can be done easily.

The wiring board 70 includes, for example, a conductive member filled in a plurality of via holes provided in the insulating base material 71, and a wiring layer 72 electrically connected to the conductive member on both sides of the base material 71. And.

Any material may be used as the material of the base material 71 of the wiring board 70. For example, ceramics and resins can be used. A resin may be selected as the material of the base material 71 from the viewpoint of low cost and ease of molding. Examples of the resin include composite materials such as phenol resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), polyethylene terephthalate (PET), unsaturated polyester, and glass epoxy. Further, it may be a rigid substrate or a flexible substrate.

The wiring layer 72 is, for example, a conductive foil (conductor layer) provided on the base material 71, and is electrically connected to a plurality of light emitting elements 30. The material of the wiring layer 72 preferably has high thermal conductivity. Examples of such a material include a conductive material such as copper. Further, the wiring layer 72 can be formed by plating, coating of a conductive paste, printing, or the like, and the thickness of the wiring layer 72 is, for example, about 5 to 50 μm.

The wiring board 70 may be joined to the light guide plate 10 or the like by any method. For example, a sheet-shaped adhesive sheet can be joined by arranging it between the surface of the covering member 40 provided on the opposite side of the light guide plate 10 and the surface of the wiring board 70 and crimping it. Further, the wiring layer 72 of the wiring board 70 and the light emitting element 30 may be electrically connected by any method. For example, the conductive member, which is a metal embedded in the via hole, can be melted by pressurization and heating and joined to the conductive member 50.

The wiring board 70 may have a laminated structure. For example, as the wiring board 70, a metal plate provided with an insulating layer on the surface may be used. Further, the wiring board 70 may be a TFT board having a plurality of TFTs (Thin-Film Transistors).

The light emitting module according to the present disclosure can be used, for example, as a backlight of a liquid crystal display device.

100, 100A, 100B, 100C ... Light emitting module 10, 10A, 10B ... Light guide plate 11 ... First main surface (light extraction surface)
111, 111A ... Optical function unit 12, 12A ... Second main surface 121 ... Positioning unit (recess)
20 ... Joining member 21 ... Top surface of joining member 30 ... Light emitting element 31 ... Semiconductor laminate 311 ... Main light emitting surface 312 ... Electrode forming surface 32 ... Electrodes 40, 40A ... Coating member 50 ... Conductive member 60 ... Diffusion member (wavelength conversion member) )
70 ... Wiring board 71 ... Base material 72 ... Wiring layer 80 ... Squeegee 81 ... Dispens nozzle 82 ... Grinding member

Claims (7)

The process of preparing a light emitting element including a semiconductor laminate and electrodes,
A step of preparing a light guide plate including a first main surface serving as a light emitting surface and a second main surface opposite to the first main surface.
A step of arranging a plurality of joining members on the second main surface of the light guide plate, and
The process of aligning the heights of the upper surfaces of the plurality of joining members and
A step of placing the light emitting element with the electrode facing up on each of the joining members having the same height on the upper surface, and
The step of arranging the covering member for covering the light emitting element including the electrode, and
The step of removing the covering member until the electrode is exposed, and
A step of forming a conductive member that electrically connects the plurality of light emitting elements, and
A method of manufacturing a light emitting module comprising. The method for manufacturing a light emitting module according to claim 1, wherein the step of aligning the heights of the upper surfaces of the joining members includes a step of aligning the heights by grinding. The method for manufacturing a light emitting module according to claim 1, wherein the step of aligning the heights of the upper surfaces of the joining members includes a step of aligning the heights by pressing. The light guide plate has a recess on the second main surface side, and has a step of arranging a diffusion member in the recess.
The method for manufacturing a light emitting module according to any one of claims 1 to 3, wherein the joining member is arranged on the diffusion member. The method for manufacturing a light emitting module according to claim 4, wherein the size of the diffusion member is about the same as the size of the recess. The method for manufacturing a light emitting module according to claim 4 or 5, wherein the method for arranging the diffusion member includes a step of adhering a molded product of the diffusion member with an adhesive. The method for manufacturing a light emitting module according to any one of claims 4 to 6, wherein the diffusion member contains a phosphor.

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