JP2024015712A - Planar light source - Google Patents

Abstract

An object of the present invention is to provide a planar light source that can increase the reliability of electrical connections. [Solution] A planar light source includes a first wiring member having a first base material and a first wiring layer, a light source electrically connected to the first wiring layer, a second base material and a second wiring layer. a second wiring member having a protective layer and a first insulating member; and a conductive member electrically connecting the first wiring layer and the second wiring layer. The surface of the second wiring layer opposite to the third surface of the second base material includes a connecting portion connected to the first wiring layer via a conductive member and a covering portion covered with a protective layer. and a first exposed portion exposed from the protective layer and located between the connection portion and the covering portion. The first insulating member is disposed at a position overlapping the first exposed portion and the conductive member in plan view. [Selection diagram] Figure 2

Description

The present invention relates to a planar light source.

For example, Patent Document 1 discloses an optical module having a connection structure in which a circuit board and an optical subassembly are connected using a flexible circuit board. Further, Patent Document 1 discloses that a flexible circuit board is bent near a mounting land portion connected to the circuit board, and has at least a coverlay on the bent portion.

Japanese Patent Application Publication No. 2007-294561

An object of the present invention is to provide a planar light source that can improve the reliability of electrical connections.

According to one aspect of the present invention, the planar light source includes a first base material having a first surface and a second surface located on the opposite side of the first surface, and a first base material disposed on the second surface side. a first wiring member having a first wiring layer; a light source disposed on the first surface side or the second surface side and electrically connected to the first wiring layer; a second base material having a light guide member disposed on a side of the second surface where the light source is disposed, a third surface, and a fourth surface located on the opposite side of the third surface; a second wiring layer disposed on the third surface side; a protective layer disposed on a surface of the second wiring layer opposite to the surface facing the third surface; and a protective layer disposed on the fourth surface side. a second wiring member disposed between the first wiring layer and the second wiring layer and electrically connecting the first wiring layer and the second wiring layer; and a conductive member. A surface of the second wiring layer opposite to the surface facing the third surface includes a connecting portion connected to the first wiring layer via the conductive member and a covering portion covered with the protective layer. and a first exposed part exposed from the protective layer and located between the connecting part and the covering part, and the first insulating member includes the first exposed part and the covering part in a plan view. It is arranged at a position overlapping the conductive member.

According to the present invention, it is possible to provide a planar light source that can improve the reliability of electrical connection.

FIG. 2 is a schematic plan view of a planar light source according to an embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a schematic plan view of the portion shown in FIG. 2. FIG. It is a schematic plan view of the part where the light guide member and light source of the planar light source of embodiment are arrange|positioned. FIG. 5 is a schematic cross-sectional view taken along the line V-V in FIG. 4. FIG. FIG. 7 is a schematic cross-sectional view of a planar light source according to another embodiment.

Hereinafter, a planar light source according to an embodiment will be described with reference to the drawings. The dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to be limiting unless specifically stated, and are merely illustrative examples. Note that the sizes, positional relationships, etc. of members shown in each drawing may be exaggerated for clarity of explanation. In addition, in the following description, the same names and symbols indicate the same or homogeneous members, and detailed descriptions will be omitted as appropriate. Moreover, as a sectional view, an end view showing only a cut surface may be shown.

In the following description, terms that indicate a particular direction or position (eg, "above", "below", and other terms including those terms) may be used. However, these terms are used only for clarity of relative orientation or position in the referenced drawings. If the relative directions or positional relationships using terms such as "upper" and "lower" in the referenced drawings are the same, the arrangement may not be the same in drawings other than this disclosure, actual products, etc. as in the referenced drawings. You can. In this specification, the positional relationship expressed as "above (or below)" means, for example, assuming that there are two members, there are cases where the two members are in contact with each other, and cases where the two members are not in contact with each other and one with the other. This includes cases where one member is located above (or below) the other member. Also, unless there is a specific description, a component covers the target to be covered, either when the component comes into contact with the target and directly covers the target, or when the component indirectly covers the target without contacting the target. including.

In the figures shown below, directions may be indicated by the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are orthogonal to each other. The light emitting surface of the planar light source is parallel to the XY plane, and the Z axis is perpendicular to the XY plane. For example, in this specification, the direction along the X axis is referred to as a first direction X, the direction along the Y axis is referred to as a second direction Y, and the direction along the Z axis is referred to as a third direction Z. Further, in this specification, unless otherwise specified, the thickness of each member is the value when the distance from the top surface to the bottom surface of each member in the third direction Z is maximum. Further, in this specification, a direction that is inclined from the X direction at an angle of 0° or more and smaller than 360° in the XY plane is defined as a lateral direction.

A planar light source 300 according to an embodiment will be described with reference to FIGS. 1 to 5.

As shown in FIG. 1, the planar light source 300 includes a light emitting module 100 and a wiring member 500. In plan view, the light emitting module 100 is surrounded by four outer edges including a first outer edge 100A and a second outer edge 100B extending in the first direction X, and a third outer edge 100C and a fourth outer edge 100D extending in the second direction Y. The light emitting surface 400 has a rectangular shape. The light emitting module 100 includes a light source 10 and a light guide member 50, as shown in FIG. The light source 10 of the light emitting module 100 is electrically connected to an external circuit via the wiring member 500.

FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. The wiring member 500 includes a first wiring member 40, a second wiring member 70, and a conductive member 80.

[First wiring member]
The first wiring member 40 is arranged below the light emitting module 100, as shown in FIG. 5, and supplies power to the light source 10. As shown in FIG. 1, a part of the first wiring member 40 extends, for example, from the first outer edge 100A side of the light emitting module 100 to the outside of the light emitting surface 400 in a plan view.

The first wiring member 40 has a first base material 41 and a first wiring layer 42. The first base material 41 has a first surface 41a and a second surface 41b located on the opposite side of the first surface 41a in the third direction Z. The first base material 41 is made of an insulating material, for example, a resin material. As the resin material of the first base material 41, for example, polyimide resin can be used. The first base material 41 may be glass fiber or paper impregnated with resin, or ceramic.

The first wiring layer 42 is arranged on the second surface 41b side of the first base material 41. As the first wiring layer 42, for example, a metal layer containing copper can be used. The first wiring layer 42 has a surface 42a facing the second surface 41b of the first base material 41. The surface 42a is in contact with the second surface 41b of the first base material 41. Alternatively, an adhesive layer may be disposed between the surface 42a of the first wiring layer 42 and the second surface 41b of the first base material 41. Further, the first wiring layer 42 has a surface 42b located on the opposite side of the surface 42a in the third direction Z. A portion 42b1 of the surface 42b is connected to the conductive member 80.

[Conductive member]
The conductive member 80 is arranged between the first wiring member 40 and the second wiring member 70 and electrically connects the first wiring member 40 and the second wiring member 70. As the conductive member 80, for example, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP) can be used. ACF includes, for example, a thermosetting resin and conductive particles contained in the thermosetting resin. The ACP includes, for example, a thermosetting resin and a conductive member contained in the thermosetting resin.

[Second wiring member]
The second wiring member 70 functions as an external connection terminal of the planar light source 300 and is connected to a connector of an external circuit. The second wiring member 70 includes a second base material 71, a second wiring layer 72, a protective layer 75, and a first insulating member 76.

The second base material 71 has a third surface 71a and a fourth surface 71b located on the opposite side of the third surface 71a in the third direction Z. The second base material 71 is made of an insulating material, and for example, the same material as the first base material 41 can be used.

The second wiring layer 72 is arranged on the third surface 71a side of the second base material 71. As the second wiring layer 72, for example, a metal layer containing the same material as the first wiring layer 42 can be used. The second wiring layer 72 has a surface 72b facing the third surface 71a of the second base material 71. The surface 72b is in contact with the third surface 71a of the second base material 71. Alternatively, an adhesive layer may be disposed between the surface 72b of the second wiring layer 72 and the third surface 71a of the second base material 71. Note that in the embodiment, the second wiring member 70 does not have a wiring layer on the fourth surface 71b side of the second base material 71.

Further, the second wiring layer 72 has a surface 72a located on the opposite side of the surface 72b in the third direction Z. The surface 72a of the second wiring layer 72 has a connecting portion 72a1, a covering portion 72a3, and a first exposed portion 72a2.

The protective layer 75 is disposed on the covering portion 72a3 on the surface 72a of the second wiring layer 72, and covers and protects the covering portion 72a3. The protective layer 75 includes a first adhesive layer 75a disposed on the surface 72a of the second wiring layer 72, and a first surface layer 75b adhered to the surface 72a of the second wiring layer 72 by the first adhesive layer 75a. . Note that the protective layer 75 may have a single layer structure. The protective layer 75 is made of an insulating material. For example, the same material as the first base material 41 can be used for the first surface layer 75b. As the material of the first adhesive layer 75a, for example, thermoplastic resin such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, or polyester resin, or thermosetting resin such as epoxy resin or silicone resin can be used. can.

The connecting portion 72a1 on the surface 72a of the second wiring layer 72 is connected to a portion 42b1 on the surface 42b of the first wiring layer 42 via the conductive member 80. FIG. 3 is a schematic plan view of the wiring member 500 shown in FIG. 2, looking at the side on which the protective layer 75 is arranged. In FIG. 3, the conductive member 80 is represented as a shaded area.

For example, when the thermosetting resin of the conductive member 80, which is ACF, is in an uncured state, the conductive member 80 connects the connection portion 72a1 of the second wiring layer 72 and the part 42b1 of the surface 42b of the first wiring layer 42. placed between. Thereafter, while applying a pressing force to the connecting portion 72a1 of the second wiring layer 72 and the part 42b1 of the first wiring layer 42 in the direction sandwiching the conductive member 80, the thermosetting resin of the conductive member 80 is heated. Let it harden. As a result, the first wiring layer 42 and the second wiring layer 72 are bonded together via the conductive member 80 and are electrically connected by the conductive particles contained in the conductive member 80. The conductive particles of the conductive member 80 are sandwiched between the first wiring layer 42 and the second wiring layer 72 in the third direction Z, which is the film thickness direction of the conductive member 80, and are sandwiched between the first wiring layer 42 and the second wiring layer 72. The wiring layer 72 is electrically connected. Conductive particles that are not sandwiched between the first wiring layer 42 and the second wiring layer 72 do not contribute to electrical connection.

On the surface 72 a of the second wiring layer 72 , connection portions with other members (for example, a connection portion 72 a 1 and a second exposed portion 72 a 4 to be described later) need to be exposed from the protective layer 75 . It is preferable that all portions of the surface 72a of the second wiring layer 72 other than the connection portions with other members be covered with the protective layer 75. However, from the viewpoint of providing a margin for positioning in the second direction Y when connecting the first wiring layer 42 and the second wiring layer 72 via the conductive member 80 and facilitating the connection, the connection portion 72a1 side The first exposed portion 72a2 is secured in the vicinity of the first exposed portion 72a2. The first exposed portion 72a2 is exposed from the conductive member 80 and the protective layer 75, and is located between the connecting portion 72a1 and the covering portion 72a3 in the second direction Y.

The second wiring member 70 has flexibility, for example. As a result, the second wiring member 70 can be treated as a flexible wiring, and the degree of freedom in connection position and orientation with an external circuit is high, and connection can be made easily.

According to this embodiment, the first insulating member 76 is arranged on the fourth surface 71b side of the second base material 71. The first insulating member 76 includes a second adhesive layer 76a disposed on the fourth surface 71b of the second base material 71, and a second adhesive layer 76a disposed on the fourth surface 71b of the second base material 71. It has a surface layer 76b. Note that the first insulating member 76 may have a single layer structure. As shown in FIG. 3, the first insulating member 76 is disposed at a position overlapping the first exposed portion 72a2 of the second wiring layer 72 and the conductive member 80 in plan view. In plan view, the first insulating member 76 is arranged at a position overlapping the boundary between the conductive member 80 and the first exposed portion 72a2. For example, the same material as the first base material 41 can be used as the material for the second surface layer 76b. For example, the same material as the first adhesive layer 75a can be used as the material for the second adhesive layer 76a.

If stress when the second wiring member 70 is bent is concentrated on the first exposed portion 72a2, it may cause separation between the conductive member 80 and the second wiring layer 72. By arranging the first insulating member 76, in the second wiring member 70, the connection portion 72a1 with the conductive member 80, the first exposed portion 72a2, and the boundary between the conductive member 80 and the first exposed portion 72a2 are located. It is possible to increase the thickness of the parts where the wiring member 70 is bent, and to increase the strength against stress when the second wiring member 70 is bent in those parts. Thereby, when the second wiring member 70 is bent, peeling between the conductive member 80 and the second wiring layer 72 can be prevented, and the electrical connection between the first wiring member 40 and the second wiring member 70 can be maintained. can increase reliability.

According to this embodiment, the second wiring layer 72 includes a first metal layer 73 and a second metal layer 74 that covers the surface of the first metal layer 73. The second metal layer 74 covers the surface of the first metal layer 73 except for the covering portion 72a3 covered with the protective layer 75 on the surface 72a of the second wiring layer 72. That is, the second metal layer 74 covers the surface of the first metal layer 73 at the connection portion 72a1, the first exposed portion 72a2, and the second exposed portion 72a4, which will be described later. Further, the second metal layer 74 covers the end face of the first metal layer 73 in the second direction Y. For example, after disposing the protective layer 75 on the surface of the first metal layer 73, the second metal layer 74 is formed on the portion of the surface of the first metal layer 73 that is exposed from the protective layer 75.

On the surface 72a of the second wiring layer 72, the covering portion 72a3 is the surface of the first metal layer 73 exposed from the second metal layer 74 and covered with the protective layer 75. On the surface 72a of the second wiring layer 72, the first exposed portion 72a2 and the connecting portion 72a1 are the surface of the second metal layer 74.

The second metal layer 74 is made of a different material from the first metal layer 73. The first metal layer 73 is, for example, a copper layer. The second metal layer 74 includes, for example, a material with higher corrosion resistance than the material of the first metal layer 73. For example, the second metal layer 74 includes gold, which has higher corrosion resistance than copper, at least on the outermost surface. Further, the second metal layer 74 includes a metal material that functions as a binder between the copper of the first metal layer 73 serving as the base and the gold on the outermost surface. The metal material used as the binder is, for example, nickel. The rigidity of the metal material (for example, nickel) included in the second metal layer 74 is higher than the rigidity of the metal material (for example, copper) included in the first metal layer 73. Stiffness is expressed, for example, by Young's modulus. Therefore, at the boundary between the first exposed portion 72a2 and the covered portion 72a3, there is a surface of a highly rigid and hard metal material (for example, nickel) included in the second metal layer 74 and a surface of a hard metal material (for example, nickel) included in the first metal layer 73. A boundary with a surface of a soft metallic material (eg copper) is located. Stress tends to concentrate at the boundary between surfaces having different rigidities (hardnesses) when the second wiring member 70 is bent.

According to this embodiment, as shown in FIG. 3, the first insulating member 76 is arranged at a position that further overlaps the protective layer 75 in plan view. In plan view, the first insulating member 76 is arranged at a position that further overlaps the boundary between the surface of the second metal layer 74 in the first exposed portion 72a2 and the surface of the first metal layer 73 in the covering portion 72a3. Thereby, the strength against stress when the second wiring member 70 is bent can be increased at the boundary between the first exposed portion 72a2 and the covering portion 72a3. As a result, when the second wiring member 70 is bent, the second metal layer 74 of the first exposed portion 72a2 is less likely to be cracked, and the reliability of the second wiring layer 72 can be increased.

According to this embodiment, the surface 72a of the second wiring layer 72 further includes a second exposed portion 72a4 exposed from the protective layer 75. The covering portion 72a3 is located between the first exposed portion 72a2 and the second exposed portion 72a4 in the second direction Y. The second exposed portion 72a4 is inserted into an external connector and electrically connected to an electrode terminal of the connector. The second exposed portion 72a4 is the surface of the second metal layer 74, and the outermost surface of the second exposed portion 72a4 contains, for example, gold, and the second exposed portion 72a4 has high corrosion resistance.

Further, the second wiring member 70 further includes a second insulating member 77 that is disposed on the fourth surface 71b side of the second base material 71 and is disposed at a position overlapping the second exposed portion 72a4 in plan view. The second insulating member 77 includes a third adhesive layer 77a disposed on the fourth surface 71b of the second base material 71, and a third adhesive layer 77a disposed on the fourth surface 71b of the second base material 71. It has a surface layer 77b. Note that the second insulating member 77 may have a single layer structure. For example, the same material as the first base material 41 can be used as the material for the third surface layer 77b. For example, the same material as the first adhesive layer 75a can be used as the material for the third adhesive layer 77a.

In the second wiring member 70, a portion where the second exposed portion 72a4, the second base material 71, and the second insulating member 77 are stacked is inserted into an external connector. The second insulating member 77 makes the portion of the second wiring member 70 where the second exposed portion 72a4 is located thicker and less likely to bend, thereby making it easier to insert the second exposed portion 72a4 into the connector.

The second insulating member 77 is arranged at a position that further overlaps the boundary between the surface of the second metal layer 74 in the second exposed portion 72a4 and the surface of the first metal layer 73 in the covering portion 72a3 in plan view. Thereby, the strength against stress when the second wiring member 70 is bent can be increased at the boundary between the second exposed portion 72a4 and the covering portion 72a3. As a result, when the second wiring member 70 is bent, the second metal layer 74 of the second exposed portion 72a4 is less likely to be cracked, and the reliability of the second wiring layer 72 can be increased.

On the fourth surface 71b side of the second base material 71, the second insulating member 77 is located away from the first insulating member 76 in the second direction Y. On the fourth surface 71b side of the second base material 71, a portion where the first insulating member 76 and the second insulating member 77 are not arranged is located between the first insulating member 76 and the second insulating member 77. For example, between the first insulating member 76 and the second insulating member 77, the fourth surface 71b of the second base material 71 is exposed.

In the second wiring member 70, the part where the first insulating member 76 and the second insulating member 77 are not arranged can be made thinner than the part where the first insulating member 76 and the second insulating member 77 are arranged, and can be easily bent. . By bending the second wiring member 70 at a portion where the first insulating member 76 and the second insulating member 77 are not arranged, stress applied to the boundary between the conductive member 80 and the first exposed portion 72a2 can be reduced, and the This makes it difficult to cause separation between the flexible member 80 and the second wiring layer 72. Furthermore, stress applied to the boundary between the first exposed portion 72a2 and the covering portion 72a3 can be reduced, making it difficult for cracks to occur in the second metal layer 74 of the first exposed portion 72a2. Moreover, the stress applied to the boundary between the second exposed portion 72a4 and the covering portion 72a3 can be reduced, making it difficult for the second metal layer 74 of the second exposed portion 72a4 to be cracked.

A protective layer 75 is arranged on the opposite side in the third direction Z of the portion where the first insulating member 76 and the second insulating member 77 are not arranged. In plan view, the protective layer 75 is disposed at a position overlapping the portion where the first insulating member 76 and the second insulating member 77 are not disposed. By making the thickness of the protective layer 75 thinner than the thickness of the second insulating member 77, the second wiring member 70 can be easily bent in the portion where the first insulating member 76 and the second insulating member 77 are not arranged. .

By making the thickness of the first insulating member 76 thinner than the thickness of the second insulating member 77, the thickness of the portion where the first wiring member 40 and the second wiring member 70 are connected can be made thinner. Furthermore, the second insulating member 77, which is thicker than the first insulating member 76, can increase the strength of the connection portion of the second wiring member 70 with the connector. For example, the thickness of the first insulating member 76 can be 10 μm or more and 25 μm or less, and the thickness of the second insulating member 77 can be 100 μm or more and 500 μm or less.

In plan view, the second insulating member 77 is arranged in the second wiring member 70 by making the area of the first insulating member 76, which is thinner than the second insulating member 77, smaller than the area of the second insulating member 77. It becomes easier to reduce the thickness of parts other than the parts.

By making the rigidity of the second insulating member 77 higher than the rigidity of the first insulating member 76, the strength of the connection portion of the second wiring member 70 with the connector can be increased.

By making the thickness of the first insulating member 76 thicker than the thickness of the protective layer 75, the second wiring member 70 can be used in the part where the protective layer 75 is arranged more than in the part where the first insulating member 76 is arranged. This makes the conductive member 80 and the second wiring layer 72 less likely to separate from each other. Furthermore, by making the rigidity of the first insulating member 76 higher than the rigidity of the protective layer 75, the second wiring member 70 has a higher rigidity in the area where the protective layer 75 is arranged than in the area where the first insulating member 76 is arranged. The conductive member 80 and the second wiring layer 72 are less likely to separate from each other.

The length of the second wiring member 70 in the second direction Y is, for example, 10 mm or more and 100 m or less. The length of the first insulating member 76 in the second direction Y and the length of the second insulating member 77 in the second direction Y are, for example, 2 mm or more and 5 mm or less. The length of the protective layer 75 in the second direction Y can be longer than the length of the first insulating member 76 in the second direction Y and the length of the second insulating member 77 in the second direction Y. The length of the protective layer 75 in the second direction Y is, for example, 10 mm or more. The length of the portion where the first insulating member 76 and the second insulating member 77 are not arranged is longer than the length of the first insulating member 76 in the second direction Y and the length of the second insulating member 77 in the second direction Y. It can be made longer. The length of the portion where the first insulating member 76 and the second insulating member 77 are not arranged is, for example, 10 mm or more. The length of the first exposed portion 72a2 in the second direction Y is, for example, greater than 0 mm and less than or equal to 2 mm.

As shown in FIG. 2, the first wiring layer 42 of the first wiring member 40 includes a third metal layer 43 and a fourth metal layer 44 that covers the surface of the third metal layer 43. A portion of the surface of the fourth metal layer 44 is a portion 42b1 of the surface 42b of the first wiring layer 42 that is connected to the conductive member 80. Further, the fourth metal layer 44 covers the end face of the third metal layer 43 in the second direction Y. The conductive member 80 is in contact with the fourth metal layer 44 of the first wiring layer 42 and the second metal layer 74 of the second wiring layer 72 . As the material of the third metal layer 43, the same metal material as the first metal layer 73 can be used. As the material of the fourth metal layer 44, the same metal material as the second metal layer 74 can be used.

The surface of the surface 42b of the first wiring layer 42 other than the portion 42b1 is the surface of the third metal layer 43. The surface of the third metal layer 43 other than a portion 42b1 on the surface 42b of the first wiring layer 42 is covered with a first insulating layer 47. The first insulating layer 47 includes a fourth adhesive layer 47a disposed on the surface of the third metal layer 43, and a fourth surface layer 47b adhered to the surface of the third metal layer 43 by the fourth adhesive layer 47a. . Note that the first insulating layer 47 may have a single layer structure. For example, the same material as the first base material 41 can be used as the material for the fourth surface layer 47b. For example, the same material as the first adhesive layer 75a can be used as the material for the fourth adhesive layer 47a.

The first wiring member 40, which is also arranged in the area where the light source 10 is arranged, has, for example, a structure in which wiring is provided on both sides. Thereby, it is possible to cope with an increase in the number of light sources 10. A third wiring layer 45 is arranged on the first surface 41a of the first base material 41, which is opposite to the second surface 41b on which the first wiring layer 42 is arranged. The third wiring layer 45 is made of the same metal material as the third metal layer 43 of the first wiring layer 42, for example. The third wiring layer 45 is electrically connected to the first wiring layer 42 via a conductive wiring connection portion 46 that penetrates from the first surface 41a to the second surface 41b of the first base material 41. Note that the first wiring member 40 may have a multilayer wiring structure including three or more layers of wiring.

The first surface 41a of the first base material 41 and the surface of the third wiring layer 45 are covered with a second insulating layer 48. The second insulating layer 48 includes a fifth adhesive layer 48a disposed on the first surface 41a of the first base material 41 and the surface of the third wiring layer 45; It has a surface 41a and a fifth surface layer 48b bonded to the surface of the third wiring layer 45. Note that the second insulating layer 48 may have a single layer structure. For example, the same material as the first base material 41 can be used as the material of the fifth surface layer 48b. As the material of the fifth adhesive layer 48a, for example, the same material as the first adhesive layer 75a can be used.

Next, the light emitting module 100 included in the planar light source 300 will be described with reference to FIGS. 4 and 5.

[Light-emitting module]
The light emitting module 100 includes a light source 10 that is disposed on the first surface 41 a side of the first base material 41 of the first wiring member 40 and electrically connected to the first wiring layer 42 .

<Light source>
The light emitting module 100 includes, for example, a plurality of light sources 10. Further, the light emitting module 100 may include one light source 10. Light source 10 includes a light emitting element 11. Light emitting element 11 includes a semiconductor structure. The semiconductor structure includes, for example, a substrate made of sapphire or gallium nitride, an n-type semiconductor layer disposed on the substrate, a p-type semiconductor layer, and a light-emitting layer sandwiched between the n-type semiconductor layer and the p-type semiconductor layer. including. Furthermore, the light emitting element 11 includes an n-side electrode electrically connected to the n-type semiconductor layer and a p-side electrode electrically connected to the p-type semiconductor layer. The n-side electrode and the p-side electrode constitute a part of the lower surface of the light emitting element 11. Furthermore, the light source 10 includes a pair of positive and negative electrodes 12. The pair of positive and negative electrodes 12 constitute a part of the lower surface of the light source 10 . One of the pair of electrodes 12 is electrically connected to the p-side electrode, and the other is electrically connected to the n-side electrode. Note that the light source 10 does not need to include the electrode 12. When the light source 10 does not include the electrode 12, the n-side electrode and the p-side electrode of the light emitting element 11 constitute a part of the lower surface of the light source 10. Further, the light source 10 does not need to include a substrate such as sapphire or gallium nitride. This makes it easier to downsize the light source 10 in the third direction Z.

The structure of the light emitting layer may be a structure with a single active layer such as a double heterostructure or a single quantum well structure (SQW), or a structure with a group of active layers such as a multiple quantum well structure (MQW). A structure with . The light emitting layer is capable of emitting visible light or ultraviolet light. The light emitting layer is capable of emitting visible light ranging from blue to red. A semiconductor structure including such a light emitting layer can include, for example, In _x Al _y Ga _1-x-y N (0≦x, 0≦y, x+y≦1). The semiconductor structure can include at least one light-emitting layer capable of emitting light as described above. For example, the semiconductor structure may include one or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may include an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer. It may be a structure in which the structures included in this order are repeated multiple times. When the semiconductor structure includes a plurality of light-emitting layers, the semiconductor structure may include light-emitting layers with different light-emitting peak wavelengths, or may contain light-emitting layers with the same light-emitting peak wavelength. Note that the same emission peak wavelength may mean, for example, a variation of several nanometers. Such combinations of light-emitting layers can be selected as appropriate. For example, when the semiconductor structure includes two light-emitting layers, combinations of blue light and blue light, green light and green light, red light and red light, and ultraviolet light and The light-emitting layer can be selected using a combination of ultraviolet light, blue light and green light, blue light and red light, or green light and red light. Further, the light emitting layer may include a plurality of active layers having different emission peak wavelengths, or may include a plurality of active layers having the same emission peak wavelength.

One light source 10 includes one light emitting element 11. One light source 10 may include a plurality of light emitting elements 11. The light emission peak wavelengths of the plurality of light emitting elements included in one light source 10 may be the same or different. For example, when one light source 10 includes two light emitting elements, blue light and green light, blue light and red light, ultraviolet light and blue light, ultraviolet light and green light, ultraviolet light and red light, or green light and red light. The emission peak wavelength of the light emitting element can be selected by combining lights. For example, when one light source 10 includes three light emitting elements, blue light, green light, and red light, ultraviolet light, green light, and red light, ultraviolet light, blue light, and green light, ultraviolet light, blue light, and red light. , the emission peak wavelength of the light emitting element can be selected by a combination of ultraviolet light, green light, red light, etc.

In the example shown in FIG. 5, the light source 10 can further include a translucent member 13 (hereinafter referred to as a light source translucent member). The light source transparent member 13 covers the top and side surfaces of the light emitting element 11 . The light-emitting element 11 can be protected by the light source transparent member 13. The light source transparent member 13 may be arranged so as to expose at least a portion of the upper surface of the light emitting element 11. This makes it easier to downsize the light source 10 in the third direction Z.

The light source translucent member 13 has translucency to light emitted by the light emitting element 11 . For example, the light source translucent member 13 may contain a translucent resin and may further contain a phosphor. As the transparent resin, for example, silicone resin or epoxy resin can be used. Further, as the phosphor, yttrium-aluminum-garnet-based phosphor (for example, (Y,Gd) ₃ (Al, Ga) ₅ O ₁₂ :Ce), lutetium-aluminum-garnet-based phosphor (for example, Lu ₃ ( Al, Ga) ₅ O ₁₂ :Ce), terbium aluminum garnet phosphor (e.g. Tb ₃ (Al, Ga) ₅ O ₁₂ :Ce), CCA phosphor (e.g. Ca ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu), SAE phosphor (e.g. Sr ₄ Al ₁₄ O ₂₅ :Eu), chlorosilicate phosphor (e.g. Ca ₈ MgSi ₄ O ₁₆ Cl ₂ :Eu), silicate phosphor (e.g. (Ba, Sr, Ca, Mg) ₂ SiO ₄ :Eu), β-sialon phosphor (e.g. (Si, Al) ₃ (O,N) ₄ :Eu) or α-sialon phosphor (e.g. Ca( Oxynitride-based phosphors such as Si, Al) ₁₂ (O, N) ₁₆ :Eu), LSN-based phosphors (e.g., (La, Y) ₃ Si ₆ N ₁₁ :Ce), BSESN-based phosphors (e.g. , (Ba,Sr) ₂ Si ₅ N ₈ :Eu), SLA-based phosphor (e.g., SrLiAl ₃ N ₄ :Eu), CASN-based phosphor (e.g., CaAlSiN ₃ :Eu), or SCASN-based phosphor (e.g., Nitride-based phosphors such as (Sr,Ca)AlSiN ₃ :Eu), KSF-based phosphors (e.g., K ₂ SiF ₆ :Mn), KSAF-based phosphors (e.g., K ₂ (Si _1-x Al _x )) F _6-x :Mn (where x satisfies 0<x<1) or a fluoride-based phosphor such as MGF-based phosphor (for example, 3.5MgO・0.5MgF ₂・GeO ₂ :Mn) , a quantum dot with a perovskite structure (for example, (Cs, FA, MA) (Pb, Sn) (F, Cl, Br, I) ₃ where FA and MA represent formamidinium and methylammonium, respectively. ), II-VI group quantum dots (e.g. CdSe), III-V group quantum dots (e.g. InP), or quantum dots with a chalcopyrite structure (e.g. (Ag,Cu)(In,Ga)(S, Se) ₂ ) etc. can be used. As the phosphor added to the light source transparent member 13, one type of phosphor may be used, or multiple types of phosphor may be used.

Further, a wavelength conversion sheet containing the above-mentioned phosphor may be placed on the light emitting module 100. The wavelength conversion sheet absorbs a part of the blue light from the light source 10 and emits yellow light, green light, and/or red light, and can emit white light as the planar light source 300. For example, white light can be obtained by combining the light source 10 capable of emitting blue light and a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, the light source 10 capable of emitting blue light and a wavelength conversion sheet containing a red phosphor and a green phosphor may be combined. Further, the light source 10 capable of emitting blue light may be combined with a plurality of wavelength conversion sheets. As the plurality of wavelength conversion sheets, for example, a wavelength conversion sheet containing a phosphor capable of emitting red light and a wavelength conversion sheet containing a phosphor capable of emitting green light can be selected. Further, the light source 10 includes a light emitting element 11 capable of emitting blue light, a light source transparent member 13 containing a phosphor capable of emitting red light, and a wavelength conversion sheet containing a phosphor capable of emitting green light. and may be combined.

As the phosphor capable of emitting yellow light used in the wavelength conversion sheet, it is preferable to use, for example, the above-mentioned yttrium-aluminum-garnet-based phosphor. Further, as the phosphor capable of emitting green light and used in the wavelength conversion sheet, examples of the phosphor having a narrow half-width of the emission peak wavelength, such as the above-mentioned quantum dots having a perovskite structure, III-V quantum dots, or chalcopyrite, can be used. Preferably, quantum dots having a structure are used. In addition, as for the phosphor capable of emitting red light used in the wavelength conversion sheet, similar to the phosphor capable of emitting green light, the half width of the emission peak wavelength is narrow, such as the above-mentioned KSF-based phosphor, KSAF-based phosphor, etc. It is preferable to use a phosphor, a III-V group quantum dot, or a quantum dot having a chalcopyrite structure.

The light source 10 can further include a covering member 15. Covering member 15 is arranged on the lower surface of light emitting element 11 . The covering member 15 is arranged so that the lower surface of the electrode 12 of the light source 10 is exposed from the covering member 15. The covering member 15 is also arranged on the lower surface of the light source transparent member 13 that covers the side surface of the light emitting element 11 .

The covering member 15 has reflectivity for light emitted by the light emitting element 11. For the covering member 15, for example, a resin member containing gas such as nitrogen or oxygen, a resin member containing light scattering particles, or the like can be used. As the resin member of the covering member 15, for example, thermoplastic resin such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, or polyester resin, or thermosetting resin such as epoxy resin or silicone resin can be used. can. Examples of the light scattering particles of the coating member 15 include titania, silica, alumina, zinc oxide, magnesium oxide, zirconia, yttria, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, and barium sulfate. Alternatively, particles such as glass can be used. Covering member 15 may contain both gas and light scattering particles.

The light source 10 may include a light adjustment member 14 (hereinafter referred to as a light source light adjustment member). The light source light adjustment member 14 constitutes at least a portion of the upper surface of the light source 10. The light source light adjustment member 14 is arranged above the light emitting element 11 . The light source light adjustment member 14 and the light emitting element 11 overlap in plan view, and the light source light adjustment member 14 is located above the light emitting element 11 in the overlapping portion. The light source light adjusting member 14 is disposed above the light source transparent member 13 and adjusts the amount and direction of light emitted from the upper surface of the light source transparent member 13. The light source light adjusting member 14 has a reflective property and a translucent property for the light emitted by the light emitting element 11. A part of the light emitted from the upper surface of the light source light transmitting member 13 is reflected by the light source light adjusting member 14, and the other part is transmitted through the light source light adjusting member 14. The transmittance of the light source light adjustment member 14 with respect to the peak wavelength of the light emitting element 11 is, for example, preferably 1% or more and 50% or less, and more preferably 3% or more and 30% or less. Since the light source 10 includes the light source adjustment member 14, it is possible to prevent the area directly above the light source 10 from becoming too bright. This reduces uneven brightness of the light emitting module 100.

The light source light adjusting member 14 can be made of, for example, a resin member containing light scattering particles. As the resin member of the light source light adjustment member 14, the same material as the resin member of the covering member 15 can be used. As the light scattering particles of the light source light adjustment member 14, the same material as the light scattering particles of the covering member 15 can be used. Further, the light source light adjustment member 14 may be, for example, a metal member such as aluminum or silver, or a dielectric multilayer film.

The light source 10 is not limited to the form shown in FIG. Other forms of the light source 10 will be described below.

The light source 10 may not include the light source adjustment member 14. This makes it easier to downsize the light source 10 in the third direction Z than when the light source 10 includes the light source light adjustment member 14 disposed above the light emitting element 11.

The light source 10 may not include the covering member 15. For example, the lower surface of the light source 10 may be configured by the lower surface of the light emitting element 11, the lower surface of the pair of electrodes 12, and the lower surface of the light source transparent member 13.

The light source 10 may include only the light emitting element 11 alone.

The light source 10 may not include the covering member 15 and the light source translucent member 13, and may have a light source light adjustment member 14 disposed on the upper surface of the light emitting element 11.

The light source 10 may have a configuration in which the light source light adjusting member 14 is disposed on the upper surface of the light emitting element 11 and the covering member 15 is disposed on the lower surface of the light emitting element 11 without including the light source transparent member 13.

The shape of the light source 10 in plan view is not particularly limited. The shape of the light source 10 in plan view can be, for example, circular, triangular, quadrangular, hexagonal, or octagonal. When the shape of the light source 10 in plan view is a quadrilateral, a pair of mutually parallel outer edges of the light source 10 may be parallel to the first direction X, or may be inclined with respect to the first direction X. In this embodiment, a pair of mutually parallel outer edges of the light source 10 are inclined at 45 degrees with respect to the first direction X, as shown in FIG.

<Light guide member>
The light emitting module 100 further includes a light guide member 50 disposed on the side where the light source 10 is disposed of the first surface 41a side and the second surface 41b side of the first base material 41. In this embodiment, the light guide member 50 is arranged on the first surface 41a side of the first base material 41. The light guide member 50 has translucency for the light emitted by the light source 10. The transmittance of the light guide member 50 for the light emission peak wavelength of the light source 10 is higher than the transmittance of the light adjustment member 30 described later for the light emission peak wavelength of the light source 10. The transmittance of the light guide member 50 with respect to the emission peak wavelength of the light source 10 is preferably 60% or more, and more preferably 80% or more, for example.

As shown in FIG. 5, the light guide member 50 has a fifth surface 51 and a sixth surface 52 located on the opposite side of the fifth surface 51 in the third direction Z. The fifth surface 51 constitutes a light emitting surface of the light emitting module 100 together with the upper surface of the light adjustment member 30 . Further, the light guide member 50 has a housing portion 53 that penetrates from the fifth surface 51 to the sixth surface 52. The light source 10 is arranged in the housing section 53 .

As shown in FIG. 4, the light guide member 50 continuously surrounds the light source 10 in plan view. The accommodating portion 53 is, for example, circular in plan view. The accommodating portion 53 may have an ellipse or a polygonal shape such as a triangle, a quadrangle, a hexagon, or an octagon in plan view. Note that the accommodating portion 53 may be a recessed portion that opens only on the sixth surface 52 side of the light guide member 50. When the accommodating part 53 is a recessed part, the accommodating part 53 has a bottom surface formed by the light guide member 50. When the accommodating portion 53 is a recessed portion, the first translucent member 21, which will be described later, covers at least the side surface of the light source 10 within the recessed portion.

As the material of the light guide member 50, the same material as the resin member of the covering member 15 can be used. Further, as the material of the light guide member 50, glass or the like may be used. The light guide member 50 may contain fluorescent material or light scattering particles.

The thickness of the light guide member 50 in the third direction Z is preferably, for example, 150 μm or more and 800 μm or less. The light guide member 50 may be composed of a single layer in the third direction Z, or may be composed of a laminate of a plurality of layers. When the light guide member 50 is composed of a laminate, a translucent adhesive may be placed between each layer. Each layer of the laminate may use a different type of base material.

In the light emitting module 100 of the embodiment, as shown in FIG. 4, the light guide member 50 is partitioned into a plurality of light emitting regions 50A by partition grooves 54 extending in the first direction X and the second direction Y. One light emitting region 50A can be used as a drive unit for local dimming. FIG. 4 shows a portion of the light emitting surface of the light emitting module 100 where, for example, four light emitting regions 50A are arranged. Note that the light emitting module 100 is not limited to having a plurality of light emitting regions 50A, but may have a configuration including one light emitting region 50A.

It is preferable that the partition groove 54 penetrates from the fifth surface 51 to the sixth surface 52 of the light guide member 50. As a result, the light guide member 50 can be separated into a plurality of parts, so that, for example, the support member 200 may warp due to a difference in thermal expansion coefficient between the light guide member 50 and a support member 200, which will be described later, that supports the light guide member 50. can be reduced. By reducing the warpage of the support member 200, it is possible to reduce the occurrence of cracks in the connection member 67, which will be described later. Further, the dividing groove 54 may be a recess that opens only on the fifth surface 51 side of the light guide member 50, or may be a recess that opens only on the sixth surface 52 side of the light guide member 50. When the dividing groove 54 is a concave portion, the dividing groove 54 has a bottom surface formed by the light guide member 50.

A member having a reflective property for the light emitted by the light source 10 may be arranged in the partition groove 54 . Thereby, the contrast ratio between the light-emitting region 50A in the light-emitting state and the light-emitting region 50A in the non-light-emitting state can be improved.

A recess can be provided on either the fifth surface 51 or the sixth surface 61 of the light guide member 50. The recess may be provided on both the fifth surface 51 and the sixth surface 61. Examples of the shape of the recess in a plan view include a straight line, a curved line, and a point. By providing the light guide member 50 with the recess, the light extraction efficiency can be increased.

The light emitting module 100 can further include a first translucent member 21, a second translucent member 22, and a light adjustment member 30.

<First translucent member>
The first translucent member 21 has translucency to the light emitted by the light source 10. The transmittance of the first transparent member 21 with respect to the emission peak wavelength of the light source 10 is preferably 60% or more, and more preferably 80% or more, for example.

The first translucent member 21 is arranged in the housing portion 53 of the light guide member 50. As shown in FIG. 5, the first translucent member 21 is located between the side surface of the light source 10 and the light guide member 50 in cross-sectional view. The first translucent member 21 is in contact with the side surface of the light source 10 . This makes it easier for light from the light source 10 to enter the first translucent member 21. The light from the light source 10 that has entered the first transparent member 21 propagates laterally within the first transparent member 21 . The light guide member 50 makes it easier to propagate the light from the light source 10 over a wider area in the lateral direction. It is preferable that the light guide member 50 be in contact with the side surface of the first light-transmitting member 21 . Thereby, the light from the light source 10 propagates within the first translucent member 21 and becomes easier to enter the light guide member 50.

In plan view, the first translucent member 21 continuously surrounds the light source 10 . This makes it easier for light from the light source 10 to enter the first translucent member 21 in 360° directions around the light source 10 .

It is preferable that the first translucent member 21 is arranged so as to expose at least a portion of the upper surface of the light source 10. This makes it easier to downsize the light emitting module 100 in the third direction Z than when the first translucent member 21 covers the entire upper surface of the light source 10. The first translucent member 21 may be arranged so as to expose the entire upper surface of the light source 10.

The first translucent member 21 may cover the entire upper surface of the light source 10. By covering the entire upper surface of the light source 10 with the first translucent member 21, it becomes easy to adjust the brightness in the area directly above the light source 10. For example, by changing the thickness of the portion of the first translucent member 21 that covers the upper surface of the light source 10, the brightness in the area directly above the light source 10 can be adjusted. By making it easier to adjust the brightness in the area directly above the light source 10, it becomes easier to reduce uneven brightness of the light emitting module 100.

The first translucent member 21 may be composed of a single layer in the third direction Z, or may be composed of a laminate of a plurality of layers. Further, the first light-transmitting member 21 may contain fluorescent material or light-scattering particles. When the first translucent member 21 is a laminate, each layer may or may not contain phosphor and/or light scattering particles. For example, the first light-transmitting member 21 may be composed of a layer containing a phosphor and a layer not containing a phosphor. As the material of the first translucent member 21, for example, the same material as the resin member of the covering member 15 can be used.

<Second translucent member>
The second translucent member 22 has translucency to the light emitted by the light source 10. The transmittance of the second transparent member 22 with respect to the emission peak wavelength of the light source 10 is preferably 60% or more, and more preferably 80% or more, for example.

As shown in FIG. 5, the second translucent member 22 is arranged between the light source 10 and the light adjustment member 30 and between the first translucent member 21 and the light adjustment member 30 in cross-sectional view. Ru. The second light-transmitting member 22 bonds the light source 10 and the light adjustment member 30 together, and bonds the first light-transmission member 21 and the light adjustment member 30 together. The second translucent member 22 is in contact with the upper surface of the light source 10 , the upper surface of the first translucent member 21 , and the lower surface of the light adjustment member 30 .

The maximum thickness of the second translucent member 22 in the third direction Z is thinner than the maximum thickness of the first translucent member 21 in the third direction Z.

When forming the first light-transmitting member 21, the upper surface of the first light-transmitting member 21 may become a concave surface due to contraction of the resin. In this case, the second light-transmitting member 22 can easily make the surface on which the light adjustment member 30 is arranged (the upper surface of the second light-transmitting member 22) flat. This makes it easier to form the light adjustment member 30.

As the material of the second translucent member 22, for example, the same material as the resin member of the first translucent member 21 can be used. In this case, the difference in refractive index between the first light-transmitting member 21 and the second light-transmitting member 22 can be reduced. Thereby, reflection of light at the interface between the first light-transmitting member 21 and the second light-transmitting member 22 can be reduced, and the amount of light extracted upward can be improved. The second light-transmitting member 22 may contain phosphor or light-scattering particles.

<Light adjustment member>
The light emitting surface of the light emitting module 100 includes the upper surface of the light adjustment member 30. The light adjustment member 30 has reflective properties and translucency for the light emitted by the light source 10. Part of the light emitted from the light source 10 is reflected by the light adjustment member 30, and the other part is transmitted through the light adjustment member 30. The transmittance of the light adjustment member 30 with respect to the peak wavelength of the light source 10 is, for example, preferably 1% or more and 50% or less, and more preferably 3% or more and 30% or less.

The light adjustment member 30 can be configured by, for example, a resin member (hereinafter referred to as a light adjustment resin member) and a reflector included in the light adjustment resin member (hereinafter referred to as a light adjustment reflector). As the material of the light adjustment resin member, the same material as the resin member of the covering member 15 can be used. As the material of the light adjusting reflector, the same material as the light scattering particles of the covering member 15 can be used. Gases such as nitrogen and oxygen may be used as the light adjusting reflector. The light adjustment member 30 may include both light scattering particles and gas. The light adjustment member 30 may be composed of a single layer or a laminate of a plurality of layers.

The light adjustment member 30 is arranged above the light source 10. As shown in FIG. 4, the light adjustment member 30 and the light source 10 overlap in plan view. By positioning the light adjustment member 30 above the light source 10, it is possible to prevent the area directly above the light source 10 from becoming too bright, and it is possible to reduce uneven brightness on the light emitting surface of the light emitting module 100.

The light adjustment member 30 is arranged on the first light-transmitting member 21 with the second light-transmitting member 22 in between. In plan view, the light adjustment member 30, the second light-transmitting member 22, and the first light-transmitting member 21 overlap. By positioning the light adjustment member 30 on the first translucent member 21, it is possible to reduce the area directly above the first translucent member 21 (the area around the light source 10) from becoming too bright, and to prevent light emission. Luminance unevenness on the light emitting surface of the module 100 can be reduced.

The light adjustment member 30 may further include a plurality of through holes 32. The through hole 32 penetrates from the upper surface to the lower surface of the light adjustment member 30. The second light-transmitting member 22 is exposed in the through-hole 32 . The light from the light source 10 is more easily transmitted through the through-hole 32 than through the portion of the light adjustment member 30 where the through-hole 32 is not located. Depending on the position, lateral size (diameter or width), number, etc. of the through holes 32, the brightness of the area directly above the light adjustment member 30 can be easily adjusted. This makes it easier to reduce brightness unevenness on the light emitting surface of the light emitting module 100.

[Support member]
The planar light source 300 of the embodiment further includes a support member 200. The support member 200 includes the first wiring member 40 described above. The light emitting module 100 is placed on a support member 200, and the support member 200 supports the light emitting module 100. The light guide member 50 is arranged on the support member 200 with the sixth surface 52 facing the upper surface of the support member 200.

The support member 200 further includes a sixth adhesive layer 63, a reflective member 64, and a seventh adhesive layer 65. The sixth adhesive layer 63 is arranged on the second insulating layer 48 of the first wiring member 40. The reflective member 64 is arranged on the sixth adhesive layer 63. The seventh adhesive layer 65 is arranged on the reflective member 64.

The sixth adhesive layer 63 is disposed between the first wiring member 40 and the reflective member 64 and bonds the first wiring member 40 and the reflective member 64 together. The sixth adhesive layer 63 can be made of, for example, a resin member containing light scattering particles. As the resin member of the sixth adhesive layer 63, for example, the same material as the resin member of the covering member 15 can be used. As the light scattering particles of the sixth adhesive layer 63, for example, the same material as the light scattering particles of the covering member 15 can be used. As the sixth adhesive layer 63, a sheet-shaped optical transparent adhesive may be used.

The reflective member 64 is arranged below the light guide member 50, below the light source 10, below the first translucent member 21, and below the partition groove 54. The reflective member 64 has reflectivity for the light emitted by the light source 10. The reflective member 64 can be configured by a resin member and a reflector contained in the resin member. As the resin member of the reflective member 64, for example, the same material as the resin member of the covering member 15 can be used. As the material of the reflector of the reflective member 64, the same material as the light scattering particles of the covering member 15 can be used. A gas such as nitrogen or oxygen may be used as the reflector of the reflective member 64. Further, the reflecting member 64 may include both light scattering particles and gas as a reflector.

The refractive index of the resin member of the sixth adhesive layer 63 is preferably lower than the refractive index of the resin member of the reflective member 64. By making the refractive index of the resin member of the sixth adhesive layer 63 lower than the refractive index of the resin member of the reflective member 64, a part of the light that travels from the reflective member 64 to the sixth adhesive layer 63 is transmitted to the reflective member 64. Total reflection is likely to occur at the interface with the sixth adhesive layer 63. As a result, the light passing downward from the light emitting module 100 can be reduced, so that the light extraction efficiency of the light emitting module 100 is improved.

The refractive index of the reflector of the reflective member 64 is preferably lower than the refractive index of the resin member of the reflective member 64. By setting the refractive index of the reflector of the reflective member 64 to be lower than the refractive index of the resin member of the reflective member 64, a part of the light from the light source 10 that is incident on the reflective member 64 is transmitted to the resin member of the reflective member 64. Total reflection is likely to occur at the interface between the reflective member 64 and the reflector. This can reduce light passing downward from the reflecting member 64, thereby improving the light extraction efficiency of the light emitting module 100.

When the refractive index of the reflector of the reflective member 64 is lower than the refractive index of the resin member of the reflective member 64, it is preferable that the refractive index of the resin member of the reflective member 64 is higher than the refractive index of the light guide member 50. This makes it easier to increase the difference in refractive index between the resin member of the reflective member 64 and the reflector of the reflective member 64, so that a part of the light from the light source 10 that has entered the reflective member 64 is reflected by the resin member of the reflective member 64. Total reflection is likely to occur at the interface between the member 64 and the reflector.

The seventh adhesive layer 65 is disposed between the reflective member 64 and the sixth surface 52 of the light guide member 50 and bonds the reflective member 64 and the light guide member 50 together. The light source 10 is disposed on the seventh adhesive layer 65 within the accommodating portion 53 of the light guide member 50 . The seventh adhesive layer 65 can be made of, for example, a resin member containing light scattering particles. As the resin member of the seventh adhesive layer 65, for example, the same material as the resin member of the covering member 15 can be used. As the light scattering particles of the seventh adhesive layer 65, for example, the same material as the light scattering particles of the covering member 15 can be used. As the seventh adhesive layer 65, a sheet-shaped optical transparent adhesive may be used.

The refractive index of the resin member of the seventh adhesive layer 65 is preferably lower than the refractive index of the light guide member 50. By making the refractive index of the resin member of the seventh adhesive layer 65 lower than the refractive index of the light guide member 50, a part of the light that travels from the light guide member 50 to the seventh adhesive layer 65 is transferred to the light guide member 50. Total reflection is likely to occur at the interface with the seventh adhesive layer 65. This makes it possible to reduce the amount of light that passes through the light emitting module 100 downward, thereby improving the light extraction efficiency of the light emitting module 100.

The refractive index of the resin member of the seventh adhesive layer 65 is preferably lower than the refractive index of the first translucent member 21 . By making the refractive index of the resin member of the seventh adhesive layer 65 lower than the refractive index of the first transparent member 21, a part of the light that travels from the first transparent member 21 to the seventh adhesive layer 65 is , total reflection is likely to occur at the interface between the first transparent member 21 and the seventh adhesive layer 65. As a result, the light passing downward from the light emitting module 100 can be reduced, so that the light extraction efficiency of the light emitting module 100 is improved.

Support member 200 further includes a connection member 67. The connection member 67 has electrical conductivity. The connection member 67 includes, for example, resin and metal particles contained in the resin. As the resin for the connecting member 67, for example, epoxy resin or phenol resin can be used. As the metal particles of the connecting member 67, for example, copper or silver particles can be used.

The connecting member 67 has a first portion 67a and a second portion 67b. The first portion 67a penetrates the seventh adhesive layer 65, the reflective member 64, the sixth adhesive layer 63, the second insulating layer 48, the first base material 41, and the first insulating layer 47 in the third direction Z. . The second portion 67b is arranged on the second surface 41b side of the first base material 41 on which the first wiring layer 42 is arranged, and is connected to the first wiring layer 42. The first portion 67a and the second portion 67b are connected to each other. For example, the first portion 67a and the second portion 67b can be integrally formed from the same material.

A pair of connecting members 67 are arranged apart from each other, corresponding to a pair of positive and negative electrodes 12 of the light source 10. Of the pair of connection members 67, the first portion 67a of one connection member 67 is connected to the positive electrode 12 below the light source 10, and the second portion 67b of the other connection member 67 is connected below the light source 10. It is connected to the negative side electrode 12 at. The electrode 12 of the light source 10 is electrically connected to the first wiring layer 42 of the first wiring member 40 via the connection member 67.

As shown in FIG. 6, the light emitting module 100 may be arranged on the second surface 41b side of the first base material 41 of the first wiring member 40. The position of the first wiring member 40 in the third direction Z shown in FIG. 6 is opposite to the position of the first wiring member 40 in the third direction Z shown in FIG.

In the form of FIG. 5, the light source 10 and the light guide member 50 are arranged on the first surface 41a side of the first base material 41, and on the second surface 41b side of the first base material 41 opposite to the first surface 41a. , the first wiring layer 42 is connected to the second wiring layer 72 of the second wiring member 70 via a conductive member 80.

In the form of FIG. 6, the light source 10 and the light guide member 50 are arranged on the second surface 41b side of the first base material 41, and the first wiring layer 42 is connected to the second wiring member through the conductive member 80. It is connected to the second wiring layer 72 of 70. In the form of FIG. 6, the first insulating member 76 and the second insulating member 77 are located on the same side as the light guide member 50. As a result, the light emitting module can be made thinner.

Embodiments of the present invention include the following planar light sources.

[Section 1]
a first wiring member having a first base material having a first surface and a second surface located on the opposite side of the first surface; and a first wiring layer disposed on the second surface side;
a light source disposed on the first surface side or the second surface side and electrically connected to the first wiring layer;
a light guide member disposed on the side where the light source is disposed of the first surface side and the second surface side;
a second base material having a third surface and a fourth surface located on the opposite side of the third surface; a second wiring layer disposed on the third surface side; a second wiring member having a protective layer disposed on a surface opposite to the third surface, and a first insulating member disposed on the fourth surface side;
a conductive member disposed between the first wiring layer and the second wiring layer and electrically connecting the first wiring layer and the second wiring layer;
Equipped with
The surface of the second wiring layer opposite to the surface facing the third surface is
a connection portion connected to the first wiring layer via the conductive member;
a covering portion covered with the protective layer;
a first exposed part exposed from the protective layer and located between the connecting part and the covering part;
has
The first insulating member is a planar light source disposed at a position overlapping the first exposed portion and the conductive member in plan view.
[Section 2]
The second wiring layer includes a first metal layer and a second metal layer that covers the surface of the first metal layer and is made of a different material from the first metal layer,
The covering portion is a surface of the first metal layer that is exposed from the second metal layer and covered with the protective layer, among the surfaces of the second wiring layer opposite to the surface facing the third surface. can be,
The first exposed portion and the connection portion are a surface of the second metal layer among the surfaces of the second wiring layer opposite to the surface facing the third surface,
Item 2. The planar light source according to Item 1, wherein the first insulating member is disposed at a position that further overlaps the protective layer in plan view.
[Section 3]
3. The planar light source according to Item 2, wherein the second metal layer includes a metal material having a higher rigidity than the metal material included in the first metal layer.
[Section 4]
4. The planar light source according to item 3, wherein the metal material included in the second metal layer is nickel.
[Section 5]
5. The planar light source according to any one of Items 2 to 4, wherein the second metal layer has a thickness thinner than the first metal layer.
[Section 6]
The surface of the second wiring layer opposite to the surface facing the third surface is a second exposed portion exposed from the protective layer, and further includes a second exposed portion that is a surface of the second metal layer. have,
The covering portion is located between the first exposed portion and the second exposed portion,
6. The planar light source according to any one of Items 2 to 5, further comprising a second insulating member placed on the fourth surface side and placed in a position overlapping the second exposed portion in plan view.
[Section 7]
7. The planar light source according to item 6, wherein the first insulating member has a thickness thinner than the second insulating member.
[Section 8]
The thickness of the first insulating member is 10 μm or more and 25 μm or less,
8. The planar light source according to item 7, wherein the second insulating member has a thickness of 100 μm or more and 500 μm or less.
[Section 9]
9. The planar light source according to any one of Items 6 to 8, wherein the area of the first insulating member is smaller than the area of the second insulating member in plan view.
[Section 10]
10. The planar light source according to any one of Items 6 to 9, wherein the second insulating member has a higher rigidity than the first insulating member.
[Section 11]
11. The planar light source according to any one of Items 1 to 10, wherein the first insulating member is thicker than the protective layer.
[Section 12]
12. The planar light source according to any one of Items 1 to 11, wherein the first insulating member has a higher rigidity than the protective layer.
[Section 13]
11. The planar light source according to any one of Items 6 to 10, wherein the thickness of the protective layer is thinner than the thickness of the second insulating member.

The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. All forms that can be implemented by appropriately modifying the design based on the above-described embodiments of the present invention by those skilled in the art also belong to the scope of the present invention as long as they encompass the gist of the present invention. In addition, those skilled in the art will be able to come up with various changes and modifications within the scope of the present invention, and these changes and modifications also fall within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10... Light source, 21... First translucent member, 22... Second translucent member, 30... Light adjustment member, 40... First wiring member, 41... First base material, 41a... First surface, 41b... Second surface, 42... First wiring layer, 45... Third wiring layer, 46... Wiring connection part, 50... Light guide member, 64... Reflection member, 67... Connection member, 70... Second wiring member, 71... Third surface 2 base material, 71a...Third surface, 71b...Fourth surface, 72...Second wiring layer, 72a1...Connection portion, 72a2...First exposed portion, 72a3...Covering portion, 72a4...Second exposed portion, 73...th 1 metal layer, 74... second metal layer, 75... protective layer, 76... first insulating member, 77... second insulating member, 80... conductive member, 100... light emitting module, 200... support member, 300... planar shape Light source, 400... Light emitting surface, 500... Wiring member

Claims (13)

a first wiring member having a first base material having a first surface and a second surface located on the opposite side of the first surface; and a first wiring layer disposed on the second surface side;
a light source disposed on the first surface side or the second surface side and electrically connected to the first wiring layer;
a light guide member disposed on the side where the light source is disposed of the first surface side and the second surface side;
a second base material having a third surface and a fourth surface located on the opposite side of the third surface; a second wiring layer disposed on the third surface side; a second wiring member having a protective layer disposed on a surface opposite to the third surface, and a first insulating member disposed on the fourth surface side;
a conductive member disposed between the first wiring layer and the second wiring layer and electrically connecting the first wiring layer and the second wiring layer;
Equipped with
The surface of the second wiring layer opposite to the surface facing the third surface is
a connection portion connected to the first wiring layer via the conductive member;
a covering portion covered with the protective layer;
a first exposed part exposed from the protective layer and located between the connecting part and the covering part;
has
The first insulating member is a planar light source disposed at a position overlapping the first exposed portion and the conductive member in plan view. The second wiring layer includes a first metal layer and a second metal layer that covers the surface of the first metal layer and is made of a different material from the first metal layer,
The covering portion is a surface of the first metal layer that is exposed from the second metal layer and covered with the protective layer, among the surfaces of the second wiring layer opposite to the surface facing the third surface. can be,
The first exposed portion and the connection portion are a surface of the second metal layer among the surfaces of the second wiring layer opposite to the surface facing the third surface,
The planar light source according to claim 1, wherein the first insulating member is disposed at a position that further overlaps the protective layer in plan view. The planar light source according to claim 2, wherein the second metal layer includes a metal material having higher rigidity than the metal material contained in the first metal layer. The planar light source according to claim 3, wherein the metal material included in the second metal layer is nickel. The planar light source according to claim 2, wherein the second metal layer is thinner than the first metal layer. The surface of the second wiring layer opposite to the surface facing the third surface is a second exposed portion exposed from the protective layer, and further includes a second exposed portion that is a surface of the second metal layer. have,
The covering portion is located between the first exposed portion and the second exposed portion,
The planar light source according to claim 2, further comprising a second insulating member disposed on the fourth surface side and in a position overlapping with the second exposed portion in plan view. The planar light source according to claim 6, wherein the first insulating member is thinner than the second insulating member. The thickness of the first insulating member is 10 μm or more and 25 μm or less,
The planar light source according to claim 7, wherein the second insulating member has a thickness of 100 μm or more and 500 μm or less. The planar light source according to claim 6, wherein the area of the first insulating member is smaller than the area of the second insulating member in plan view. The planar light source according to claim 6, wherein the second insulating member has a higher rigidity than the first insulating member. The planar light source according to claim 1, wherein the first insulating member is thicker than the protective layer. The planar light source according to claim 1, wherein the first insulating member has a higher rigidity than the protective layer. The planar light source according to claim 6, wherein the thickness of the protective layer is thinner than the thickness of the second insulating member.

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