JP7539625B2 - Surface Light Source - Google Patents

Description

The present invention relates to a surface light source.

For example, Patent Document 1 discloses an optical module having a connection structure that connects a circuit board and an optical subassembly using a flexible circuit board. Patent Document 1 also discloses that the flexible circuit board is folded near the mounting land portion that is connected to the circuit board, and that the folded portion has at least a coverlay.

JP 2007-294561 A

The present invention aims to provide a surface light source that can increase the reliability of electrical connections.

According to one aspect of the present invention, a surface light source includes a first wiring member having a first substrate having a first surface and a second surface located opposite the first surface, a first wiring layer arranged on the second surface side, a light source arranged on the first surface side or the second surface side and electrically connected to the first wiring layer, a light guide member arranged on the side of the first surface side or the second surface side on which the light source is arranged, a third surface and a fourth surface located opposite the third surface, a second substrate having a second wiring layer arranged on the third surface side, a protective layer arranged on the surface of the second wiring layer opposite the surface facing the third surface, and a first insulating member arranged on the fourth surface side, and a conductive member arranged between the first wiring layer and the second wiring layer and electrically connecting the first wiring layer and the second wiring layer. The surface of the second wiring layer opposite to the surface facing the third surface has a connection portion connected to the first wiring layer via the conductive member, a covering portion covered by the protective layer, and a first exposed portion exposed from the protective layer and located between the connection portion and the covering portion, and the first insulating member is disposed in a position overlapping the first exposed portion and the conductive member in a plan view.

The present invention provides a surface light source that can increase the reliability of electrical connections.

FIG. 2 is a schematic plan view of a surface light source according to the embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. FIG. 3 is a schematic plan view of the portion shown in FIG. 2 . 2 is a schematic plan view of a portion where a light guide member and a light source of the surface light source of the embodiment are arranged. FIG. FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. 4 . FIG. 11 is a schematic cross-sectional view of a surface light source according to another embodiment.

The surface light source of the embodiment will be described below with reference to the drawings. Unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in the embodiment are not intended to be limiting, but are merely illustrative examples. Note that the sizes and positional relationships of the components shown in each drawing may be exaggerated to clarify the explanation. In the following explanation, the same names and symbols indicate the same or similar components, and detailed explanations will be omitted as appropriate. In addition, as a cross-sectional view, an end view showing only the cut surface may be shown.

In the following description, terms indicating a specific direction or position (e.g., "upper", "lower", and other terms including these terms) may be used. However, these terms are merely used to make the relative direction or position in the referenced drawings easier to understand. As long as the relative direction or position relationship of terms such as "upper" and "lower" in the referenced drawings is the same, the arrangement in drawings other than this disclosure, in actual products, etc., does not have to be the same as in the referenced drawings. In this specification, the positional relationship expressed as "upper (or lower)" includes, for example, when there are two members, a case in which the two members are in contact with each other, and a case in which the two members are not in contact with each other and one member is located above (or below) the other member. In addition, unless otherwise specified, a member covering an object to be covered includes a case in which the member is in contact with the object to be covered and directly covers the object to be covered, and a case in which the member indirectly covers the object to be covered without contacting the object to be covered.

In the diagrams shown below, directions may be indicated by the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are mutually orthogonal. The light-emitting surface of the surface light source is parallel to the XY plane, and the Z-axis is orthogonal to the XY plane. For example, in this specification, the direction along the X-axis is the first direction X, the direction along the Y-axis is the second direction Y, and the direction along the Z-axis is the third direction Z. Furthermore, in this specification, unless otherwise specified, the thickness of each member is the value when the distance from the upper surface to the lower surface of each member in the third direction Z is maximum. Furthermore, in this specification, the direction inclined from the X direction at an angle of 0° or more and less than 360° in the XY plane is the horizontal direction.

The surface light source 300 of the embodiment will be described with reference to Figures 1 to 5.

As shown in FIG. 1, the surface light source 300 has a light-emitting module 100 and a wiring member 500. In a plan view, the light-emitting module 100 has a rectangular light-emitting surface 400 surrounded by four outer edges including a first outer edge 100A and a second outer edge 100B extending in a first direction X, and a third outer edge 100C and a fourth outer edge 100D extending in a second direction Y. As shown in FIG. 5, the light-emitting module 100 has a light source 10 and a light-guiding member 50. The light source 10 of the light-emitting module 100 is electrically connected to an external circuit via the wiring member 500.

Figure 2 is a schematic cross-sectional view taken along line II-II in Figure 1. The wiring member 500 has a first wiring member 40, a second wiring member 70, and a conductive member 80.

[First wiring member]
5, the first wiring member 40 is disposed below the light emitting module 100 and supplies power to the light source 10. As shown in Fig. 1, a part of the first wiring member 40 extends from, for example, 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 substrate 41 and a first wiring layer 42. The first substrate 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 substrate 41 is made of an insulating material, for example, a resin material. For example, a polyimide resin can be used as the resin material of the first substrate 41. The first substrate 41 may be made of glass fiber or paper impregnated with resin, or may be ceramic.

The first wiring layer 42 is disposed on the second surface 41b side of the first substrate 41. For example, a metal layer containing copper can be used as the first wiring layer 42. The first wiring layer 42 has a surface 42a facing the second surface 41b of the first substrate 41. The surface 42a is in contact with the second surface 41b of the first substrate 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 substrate 41. The first wiring layer 42 also 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 disposed 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. For example, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP) can be used as the conductive member 80. The ACF has, for example, a thermosetting resin and conductive particles contained in the thermosetting resin. The ACP has, 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 surface light source 300, and is connected to a connector of an external circuit. The second wiring member 70 has a second base material 71, a second wiring layer 72, a protective layer 75, and a first insulating member 76.

The second substrate 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 substrate 71 is made of an insulating material, and may be made of, for example, the same material as the first substrate 41.

The second wiring layer 72 is disposed on the third surface 71a side of the second substrate 71. For example, a metal layer containing the same material as the first wiring layer 42 can be used as the second wiring layer 72. The second wiring layer 72 has a surface 72b facing the third surface 71a of the second substrate 71. The surface 72b is in contact with the third surface 71a of the second substrate 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 substrate 71. In the embodiment, the second wiring member 70 does not have a wiring layer on the fourth surface 71b side of the second substrate 71.

The second wiring layer 72 also 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 connection 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 has 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. The protective layer 75 may have a single-layer structure. The protective layer 75 is made of an insulating material. The first surface layer 75b may be made of the same material as the first substrate 41, for example. The material of the first adhesive layer 75a may be, for example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin.

The connection 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 a conductive member 80. FIG. 3 is a schematic plan view of the surface side on which the protective layer 75 is disposed in the wiring member 500 shown in FIG. 2. In FIG. 3, the conductive member 80 is represented as a shaded area.

For example, the conductive member 80, which is an ACF, is placed between the connection portion 72a1 of the second wiring layer 72 and the part 42b1 of the surface 42b of the first wiring layer 42 while the thermosetting resin of the conductive member 80 is in an uncured state. After that, the thermosetting resin of the conductive member 80 is thermally cured while applying a pressing force to the connection portion 72a1 of the second wiring layer 72 and the part 42b1 of the first wiring layer 42 in the direction in which the conductive member 80 is sandwiched. As a result, the first wiring layer 42 and the second wiring layer 72 are bonded 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 electrically connect the first wiring layer 42 and the second wiring layer 72. The conductive particles that are not sandwiched between the first wiring layer 42 and the second wiring layer 72 do not contribute to the electrical connection.

On the surface 72a of the second wiring layer 72, the connection portion with other members (for example, the connection portion 72a1 and the second exposed portion 72a4 described later) needs to be exposed from the protective layer 75. On the surface 72a of the second wiring layer 72, all parts other than the connection portion with other members are preferably covered with the protective layer 75. However, in order to allow for a margin in the alignment in the second direction Y when connecting the first wiring layer 42 and the second wiring layer 72 via the conductive member 80 and to facilitate the connection, the first exposed portion 72a2 is secured near the connection portion 72a1 side. The first exposed portion 72a2 is exposed from the conductive member 80 and the protective layer 75, and is located between the connection portion 72a1 and the covered portion 72a3 in the second direction Y.

The second wiring member 70 has, for example, flexibility. This allows the second wiring member 70 to be treated as a flexible wiring, allowing for a high degree of freedom in the connection position and direction with an external circuit, and facilitating connection.

According to this embodiment, the first insulating member 76 is disposed on the fourth surface 71b side of the second substrate 71. The first insulating member 76 has a second adhesive layer 76a disposed on the fourth surface 71b of the second substrate 71, and a second surface layer 76b adhered to the fourth surface 71b of the second substrate 71 by the second adhesive layer 76a. The first insulating member 76 may have a single-layer structure. As shown in FIG. 3, in a plan view, 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 a plan view, the first insulating member 76 is disposed 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 substrate 41 can be used as the material of the second surface layer 76b. For example, the same material as the material of the first adhesive layer 75a can be used as the material of the second adhesive layer 76a.

If the stress generated when the second wiring member 70 is bent is concentrated on the first exposed portion 72a2, this may cause the conductive member 80 and the second wiring layer 72 to peel off. By disposing the first insulating member 76, the thickness of the connection portion 72a1 with the conductive member 80, the first exposed portion 72a2, and the portion where the boundary between the conductive member 80 and the first exposed portion 72a2 is located in the second wiring member 70 can be increased, and the strength against the stress when the second wiring member 70 is bent in these portions can be increased. As a result, when the second wiring member 70 is bent, it is possible to make it difficult for the conductive member 80 and the second wiring layer 72 to peel off, and the reliability of the electrical connection between the first wiring member 40 and the second wiring member 70 can be increased.

According to this embodiment, the second wiring layer 72 has 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 described later. In addition, 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 that is exposed from the second metal layer 74 and covered by the protective layer 75. On the surface 72a of the second wiring layer 72, the first exposed portion 72a2 and the connection portion 72a1 are the surface of the second metal layer 74.

The second metal layer 74 is made of a material different 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 that is more corrosion-resistant than the material of the first metal layer 73. For example, the second metal layer 74 includes gold, which is more corrosion-resistant than copper, at least on the outermost surface. The second metal layer 74 also includes a metal material that functions as a binder between the copper of the first metal layer 73, which is the base, and the gold of the outermost surface. The metal material as this 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. The rigidity 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 boundary between the surface of the hard metal material (e.g., nickel) contained in the second metal layer 74 and the surface of the soft metal material (e.g., copper) contained in the first metal layer 73 with low rigidity. At the boundary between such surfaces with different rigidity (hardness), stress is likely to concentrate when the second wiring member 70 is bent.

According to this embodiment, as shown in FIG. 3, in a plan view, the first insulating member 76 is arranged at a position that further overlaps with the protective layer 75. In a plan view, the first insulating member 76 is arranged at a position that further overlaps with the boundary between the surface of the second metal layer 74 of the first exposed portion 72a2 and the surface of the first metal layer 73 in the covered portion 72a3. This makes it possible to increase the strength against stress when the second wiring member 70 is bent at the boundary between the first exposed portion 72a2 and the covered portion 72a3. As a result, when the second wiring member 70 is bent, it is possible to make it difficult for cracks to occur in the second metal layer 74 of the first exposed portion 72a2, and to increase the reliability of the second wiring layer 72.

According to this embodiment, the surface 72a of the second wiring layer 72 further has 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.

The second wiring member 70 further includes a second insulating member 77 disposed on the fourth surface 71b side of the second substrate 71 and disposed at a position overlapping the second exposed portion 72a4 in a plan view. The second insulating member 77 has a third adhesive layer 77a disposed on the fourth surface 71b of the second substrate 71 and a third surface layer 77b adhered to the fourth surface 71b of the second substrate 71 by the third adhesive layer 77a. The second insulating member 77 may have a single-layer structure. The material of the third surface layer 77b may be, for example, the same material as that of the first substrate 41. The material of the third adhesive layer 77a may be, for example, the same material as that of the first adhesive layer 75a.

In the second wiring member 70, the portion where the second exposed portion 72a4, the second substrate 71, and the second insulating member 77 are laminated is inserted into an external connector. The second insulating member 77 thickens the portion of the second wiring member 70 where the second exposed portion 72a4 is located, making it less likely to bend, and thus facilitating insertion of the second exposed portion 72a4 into the connector.

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

On the fourth surface 71b side of the second substrate 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 substrate 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, the fourth surface 71b of the second substrate 71 is exposed between the first insulating member 76 and the second insulating member 77.

In the second wiring member 70, the portion where the first insulating member 76 and the second insulating member 77 are not arranged can be made thinner than the portion 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 in the portion where the first insulating member 76 and the second insulating member 77 are not arranged, the stress applied to the boundary between the conductive member 80 and the first exposed portion 72a2 can be reduced, and peeling between the conductive member 80 and the second wiring layer 72 can be made less likely to occur. In addition, the stress applied to the boundary between the first exposed portion 72a2 and the covering portion 72a3 can be reduced, and cracks can be made less likely to occur in the second metal layer 74 of the first exposed portion 72a2. In addition, the stress applied to the boundary between the second exposed portion 72a4 and the covering portion 72a3 can be reduced, and cracks can be made less likely to occur in the second metal layer 74 of the second exposed portion 72a4.

A protective layer 75 is disposed on the opposite side in the third direction Z to the portion where the first insulating member 76 and the second insulating member 77 are not disposed. In a 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 disposed.

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. In addition, by making the second insulating member 77 thicker than the first insulating member 76, the strength of the connection portion of the second wiring member 70 with the connector can be increased. For example, the thickness of the first insulating member 76 can be made 10 μm or more and 25 μm or less, and the thickness of the second insulating member 77 can be made 100 μm or more and 500 μm or less.

By making the area of the first insulating member 76, which is thinner than the second insulating member 77 in a plan view, smaller than the area of the second insulating member 77, it becomes easier to thin the second wiring member 70 except for the portion where the second insulating member 77 is located.

By making the rigidity of the second insulating member 77 greater than the rigidity of the first insulating member 76, the strength of the connection portion between the second wiring member 70 and 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 is more likely to bend at the portion where the protective layer 75 is arranged than at the portion where the first insulating member 76 is arranged, making it less likely that peeling will occur between the conductive member 80 and the second wiring layer 72. Also, by making the rigidity of the first insulating member 76 higher than the rigidity of the protective layer 75, the second wiring member 70 is more likely to bend at the portion where the protective layer 75 is arranged than at the portion where the first insulating member 76 is arranged, making it less likely that peeling will occur between the conductive member 80 and the second wiring layer 72.

The length in the second direction Y of the second wiring member 70 is, for example, 10 mm or more and 100 m or less. The length in the second direction Y of the first insulating member 76 and the length in the second direction Y of the second insulating member 77 are, for example, 2 mm or more and 5 mm or less. The length in the second direction Y of the protective layer 75 can be longer than the length in the second direction Y of the first insulating member 76 and the length in the second direction Y of the second insulating member 77. The length in the second direction Y of the protective layer 75 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 can be longer than the length in the second direction Y of the first insulating member 76 and the length in the second direction Y of the second insulating member 77. 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 in the second direction Y of the first exposed portion 72a2 is, for example, greater than 0 mm and less than 2 mm.

2, the first wiring layer 42 of the first wiring member 40 has a third metal layer 43 and a fourth metal layer 44 covering the surface of the third metal layer 43. A part of the surface of the fourth metal layer 44 is a part 42b1 of the surface 42b of the first wiring layer 42 that is connected to the conductive member 80. The fourth metal layer 44 also 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. The third metal layer 43 can be made of the same metal material as the first metal layer 73. The fourth metal layer 44 can be made of the same metal material as the second metal layer 74.

The surface of the third metal layer 43 is the surface of the third metal layer 43 except for the portion 42b1 on the surface 42b of the first wiring layer 42. The surface of the third metal layer 43 is covered with the first insulating layer 47. The first insulating layer 47 has a fourth adhesive layer 47a arranged 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. The first insulating layer 47 may have a single-layer structure. The material of the fourth surface layer 47b may be, for example, the same material as the first base material 41. The material of the fourth adhesive layer 47a may be, for example, the same material as the first adhesive layer 75a.

The first wiring member 40, which is also arranged in the region where the light source 10 is arranged, has a structure having wiring on both sides, for example. This makes it possible to accommodate an increase in the number of light sources 10. A third wiring layer 45 is arranged on the first surface 41a opposite to the second surface 41b on which the first wiring layer 42 is arranged in the first substrate 41. The third wiring layer 45 is made of, for example, the same metal material as the third metal layer 43 of the first wiring layer 42. 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 substrate 41. The first wiring member 40 may have a multilayer wiring structure with three or more layers of wiring.

The first surface 41a of the first substrate 41 and the surface of the third wiring layer 45 are covered with a second insulating layer 48. The second insulating layer 48 has a fifth adhesive layer 48a arranged on the first surface 41a of the first substrate 41 and the surface of the third wiring layer 45, and a fifth surface layer 48b adhered to the first surface 41a of the first substrate 41 and the surface of the third wiring layer 45 by the fifth adhesive layer 48a. The second insulating layer 48 may have a single layer structure. The material of the fifth surface layer 48b may be, for example, the same material as the first substrate 41. The material of the fifth adhesive layer 48a may be, for example, the same material as the first adhesive layer 75a.

Next, the light-emitting module 100 provided in the surface light source 300 will be described with reference to Figures 4 and 5.

[Light emitting module]
The light emitting module 100 includes a light source 10 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. The light emitting module 100 may also include one light source 10. The light source 10 includes a light emitting element 11. The light emitting element 11 includes a semiconductor structure. The semiconductor structure includes, for example, a substrate such as 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. The light emitting element 11 also 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 form 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 form 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. The light source 10 does not need to include the electrodes 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 form part of the lower surface of the light source 10. In addition, the light source 10 does not need to include a substrate such as sapphire or gallium nitride. This makes it easier to reduce the size of the light source 10 in the third direction Z.

The structure of the light emitting layer may be a structure having a single active layer such as a double heterostructure or a single quantum well structure (SQW), or a structure having a group of active layers such as a multiple quantum well structure (MQW). The light emitting layer can emit visible light or ultraviolet light. The light emitting layer can emit visible light from blue to red. An example of a semiconductor structure including such a light emitting layer may include In _x Al _y Ga _1-x-y N (0≦x, 0≦y, x+y≦1). The semiconductor structure may include at least one light emitting layer capable of emitting the above-mentioned light. 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 a structure in which a structure including an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer in order is repeated multiple times. When the semiconductor structure includes multiple light emitting layers, the semiconductor structure may include light emitting layers having different emission peak wavelengths, or may include light emitting layers having the same emission peak wavelength. The same emission peak wavelength may vary by, for example, about several nm. Such a combination of light-emitting layers can be appropriately selected, and for example, when the semiconductor structure includes two light-emitting layers, the light-emitting layers can be selected from combinations of blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light, etc. Furthermore, 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 multiple light-emitting elements 11. The emission peak wavelengths of the multiple 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, the emission peak wavelengths of the light-emitting elements can be selected from combinations such as 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. For example, when one light source 10 includes three light-emitting elements, the emission peak wavelengths of the light-emitting elements can be selected from combinations such as blue light and green light and red light, ultraviolet light and green light and red light, ultraviolet light and blue light and green light, ultraviolet light and blue light and red light, ultraviolet light and green light and red light.

In the example shown in FIG. 5, the light source 10 may further include a light-transmissive member 13 (hereinafter referred to as the light-source light-transmissive member). The light-source light-transmissive member 13 covers the upper and side surfaces of the light-emitting element 11. The light-source light-transmissive member 13 can protect the light-emitting element 11. The light-source light-transmissive 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 miniaturize the light source 10 in the third direction Z.

The light source translucent member 13 has translucency to the light emitted by the light emitting element 11. For example, the light source translucent member 13 includes a translucent resin and may further include a phosphor. As the translucent resin, for example, a silicone resin, an epoxy resin, or the like can be used. Examples of phosphors include yttrium aluminum garnet phosphors (e.g., (Y,Gd) ₃ (Al,Ga) _5O12 :Ce), lutetium aluminum garnet phosphors (e.g., _Lu3 (Al,Ga) _{5O12 :} Ce), terbium aluminum garnet phosphors (e.g., _Tb3 (Al,Ga _{)5O12:Ce), CCA phosphors (e.g., Ca10(PO4)6Cl2 : Eu ) , SAE} phosphors (e.g., _{Sr4Al14O25 :} Eu ₎ , chlorosilicate phosphors (e.g. _{, Ca8MgSi4O16Cl2 :} Eu ₎ , silicate phosphors (e.g., (Ba, _Sr ,Ca,Mg) _{2SiO 4} :Eu), β-sialon phosphor (for example, (Si,Al) ₃ (O,N) ₄ :Eu) or α-sialon phosphor (for example, Ca(Si,Al) ₁₂ (O,N) ₁₆ :Eu), nitride phosphors such as LSN phosphor (for example, ₍ La,Y) _{3Si6N11 :} Ce), BSESN phosphor (for example, (Ba,Sr) _{2Si5N8 : Eu} ), SLA phosphor (for example, _SrLiAl3N4 :Eu), CASN phosphor (for example, _{CaAlSiN3 :} Eu) or SCASN phosphor (for example, (Sr,Ca) _AlSiN3 :Eu), _KSF phosphor (for example, _K2SiF6 Fluoride-based phosphors such as KSAF-based phosphors (e.g., _K2 ( _{Si1-xAlx )} F6 _-x :Mn, where x satisfies 0<x<1) or MGF-based phosphors (e.g., _{3.5MgO.0.5MgF2.GeO2} :Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I) ₃ , where FA and MA represent formamidinium and _{methylammonium} , respectively), II-VI quantum dots (e.g., CdSe), III-V quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se) ₂ ), etc., can be used. The phosphor added to the light source transmissive member 13 may be one type of phosphor or a plurality of types of phosphors.

Also, 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 as the planar light source 300, it can emit white light. For example, white light can be obtained by combining a light source 10 capable of emitting blue light with a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, a light source 10 capable of emitting blue light may be combined with a wavelength conversion sheet containing a red phosphor and a green phosphor. Also, a light source 10 capable of emitting blue light may be combined with multiple wavelength conversion sheets. As the multiple 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. Also, a light source 10 having a light emitting element 11 capable of emitting blue light and a light source translucent member 13 containing a phosphor capable of emitting red light may be combined with a wavelength conversion sheet containing a phosphor capable of emitting green light.

As the phosphor capable of emitting yellow light used in the wavelength conversion sheet, for example, the above-mentioned yttrium aluminum garnet phosphor is preferably used. As the phosphor capable of emitting green light used in the wavelength conversion sheet, it is preferable to use quantum dots having a narrow half-width of the emission peak wavelength, for example, quantum dots having a perovskite structure, III-V group quantum dots, or quantum dots having a chalcopyrite structure, as the above-mentioned. As the phosphor capable of emitting red light used in the wavelength conversion sheet, it is preferable to use quantum dots having a narrow half-width of the emission peak wavelength, for example, the above-mentioned KSF phosphor, KSAF phosphor, III-V group quantum dots, or quantum dots having a chalcopyrite structure, as the same as the phosphor capable of emitting green light.

The light source 10 may further include a covering member 15. The covering member 15 is disposed on the underside of the light-emitting element 11. The covering member 15 is disposed so that the underside of the electrode 12 of the light source 10 is exposed from the covering member 15. The covering member 15 is also disposed on the underside of the light source translucent member 13 that covers the side surface of the light-emitting element 11.

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

The light source 10 may include a light adjustment member 14 (hereinafter referred to as the light source light adjustment member). The light source light adjustment member 14 constitutes at least a part of the upper surface of the light source 10. The light source light adjustment member 14 is disposed above the light emitting element 11. In a plan view, the light source light adjustment member 14 and the light emitting element 11 overlap, and the light source light adjustment member 14 is located above the light emitting element 11 at the overlapping portion. The light source light adjustment member 14 is disposed above the light source translucent member 13 and adjusts the amount and emission direction of light emitted from the upper surface of the light source translucent member 13. The light source light adjustment member 14 has reflectivity and translucency with respect to the light emitted by the light emitting element 11. A part of the light emitted from the upper surface of the light source translucent member 13 is reflected by the light source light adjustment member 14, and the other part is transmitted through the light source light adjustment 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% to 50%, and more preferably 3% to 30%. By including the light source light adjustment member 14 in the light source 10, it is possible to prevent the area directly above the light source 10 from becoming too bright. This reduces uneven brightness in the light-emitting module 100.

The light source light adjustment member 14 can be made of, for example, a resin member containing light scattering particles. The resin member of the light source light adjustment member 14 can be made of the same material as the resin member of the covering member 15. The light scattering particles of the light source light adjustment member 14 can be made of the same material as the light scattering particles of the covering member 15. The light source light adjustment member 14 can also be made of, 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. 5. Other forms of the light source 10 are described below.

The light source 10 does not need to include the light source light adjustment member 14. This makes it easier to make the light source 10 smaller in size in the third direction Z than when the light source 10 includes the light source light adjustment member 14 arranged above the light emitting element 11.

The light source 10 does not need to include the covering member 15. For example, the bottom surface of the light source 10 may be formed by the bottom surface of the light-emitting element 11, the bottom surfaces of the pair of electrodes 12, and the bottom surface of the light source translucent member 13.

The light source 10 may consist of only a single light-emitting element 11.

The light source 10 may not include a covering member 15 and a 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 not include a 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 and a covering member 15 disposed on the lower surface of the light emitting element 11.

The shape of the light source 10 in a planar view is not particularly limited. The shape of the light source 10 in a planar view can be, for example, a circle, a triangle, a rectangle, a hexagon, or an octagon. When the shape of the light source 10 in a planar view is a rectangle, a pair of 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, as shown in FIG. 4, a pair of parallel outer edges of the light source 10 are inclined at 45° with respect to the first direction X.

<Light guiding member>
The light emitting module 100 further includes a light guide member 50 arranged on the first surface 41a side or the second surface 41b side of the first base material 41 on which the light source 10 is arranged. 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 light emitted by the light source 10. The transmittance of the light guide member 50 for the emission peak wavelength of the light source 10 is higher than the transmittance of the light adjustment member 30 described later for the emission peak wavelength of the light source 10. The transmittance of the light guide member 50 for 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-guiding 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, together with the upper surface of the light adjustment member 30, constitutes the light-emitting surface of the light-emitting module 100. The light-guiding member 50 also has a housing portion 53 that penetrates from the fifth surface 51 to the sixth surface 52. The light source 10 is disposed in the housing portion 53.

As shown in FIG. 4, the light guide member 50 continuously surrounds the periphery of the light source 10 in a plan view. The storage section 53 is, for example, circular in a plan view. The storage section 53 may be elliptical or polygonal, such as triangular, rectangular, hexagonal, or octagonal, in a plan view. The storage section 53 may be a recess that opens only on the sixth surface 52 side of the light guide member 50. When the storage section 53 is a recess, the storage section 53 has a bottom surface formed by the light guide member 50. When the storage section 53 is a recess, the first light-transmissive member 21 described later covers at least the side surface of the light source 10 within the recess.

The light-guiding member 50 may be made of the same material as the resin member of the covering member 15. The light-guiding member 50 may also be made of glass or the like. The light-guiding member 50 may contain phosphors or light-scattering particles.

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

In the light-emitting module 100 of the embodiment, as shown in FIG. 4, the light-guiding 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 driving unit for local dimming. FIG. 4 shows a portion on 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 a plurality of light-emitting regions 50A, and may be configured with one light-emitting region 50A.

The partition groove 54 preferably penetrates from the fifth surface 51 to the sixth surface 52 of the light guide member 50. This allows the light guide member 50 to be separated into a plurality of parts, so that, for example, warping of the support member 200 caused by the difference in thermal expansion coefficient between the light guide member 50 and the support member 200 described below that supports the light guide member 50 can be reduced. By reducing the warping of the support member 200, it is possible to reduce the occurrence of cracks in the connection member 67 described below. In addition, the partition 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 partition groove 54 is a recess, the partition groove 54 has a bottom surface formed by the light guide member 50.

A member that is reflective to the light emitted by the light source 10 may be disposed within the partition groove 54. This can improve 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.

A recess can be provided on either the fifth surface 51 or the sixth surface 61 of the light-guiding 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 curve, and a point. Providing a recess in the light-guiding member 50 can increase the light extraction efficiency.

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

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

The first light-transmissive member 21 is disposed in the housing 53 of the light-guiding member 50. As shown in FIG. 5, the first light-transmissive member 21 is located between the side of the light source 10 and the light-guiding member 50 in a cross-sectional view. The first light-transmissive member 21 is in contact with the side of the light source 10. This makes it easier for light from the light source 10 to enter the first light-transmissive member 21. The light from the light source 10 that enters the first light-transmissive member 21 propagates laterally within the first light-transmissive member 21. The light-guiding member 50 makes it easier for the light from the light source 10 to propagate to a wider area in the lateral direction. It is preferable that the light-guiding member 50 be in contact with the side of the first light-transmissive member 21. This makes it easier for light from the light source 10 to propagate through the first light-transmissive member 21 and enter the light-guiding member 50.

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

The first translucent member 21 is preferably arranged so as to expose at least a portion of the upper surface of the light source 10. This makes it easier to reduce the size of 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 having the first translucent member 21 cover the entire upper surface of the light source 10, it becomes easier to adjust the brightness in the area directly above the light source 10. For example, the brightness in the area directly above the light source 10 can be adjusted by changing the thickness of the portion of the first translucent member 21 that covers the upper surface of the light source 10. By making it easier to adjust the brightness in the area directly above the light source 10, it becomes easier to reduce brightness unevenness in the light-emitting module 100.

The first light-transmissive member 21 may be composed of a single layer in the third direction Z, or may be composed of a laminate of multiple layers. The first light-transmissive member 21 may also contain phosphors and light-scattering particles. When the first light-transmissive member 21 is a laminate, each layer may or may not contain phosphors and/or light-scattering particles. For example, the first light-transmissive member 21 may be composed of a layer containing phosphors and a layer not containing phosphors. For example, the same material as the resin member of the covering member 15 can be used as the material of the first light-transmissive member 21.

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

As shown in FIG. 5, the second translucent member 22 is disposed 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 a cross-sectional view. The second translucent member 22 bonds the light source 10 and the light adjustment member 30, and bonds the first translucent member 21 and the light adjustment member 30. The second translucent member 22 contacts 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 translucent member 21, the upper surface of the first translucent member 21 may become concave due to the shrinkage of the resin. In this case, the second translucent member 22 makes it easier to flatten the placement surface of the light adjustment member 30 (the upper surface of the second translucent member 22). This makes it easier to form the light adjustment member 30.

The material of the second translucent member 22 can be, for example, the same material as the resin material of the first translucent member 21. In this case, the difference in refractive index between the first translucent member 21 and the second translucent member 22 can be reduced. This can reduce the reflection of light at the interface between the first translucent member 21 and the second translucent member 22, and can improve the amount of light extracted upward. The second translucent member 22 may contain phosphors or light scattering particles.

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

The light adjustment member 30 can be composed of, for example, a resin member (hereinafter referred to as the light adjustment resin member) and a reflector (hereinafter referred to as the light adjustment reflector) contained in the light adjustment resin member. The material of the light adjustment resin member can be the same as that of the resin member of the covering member 15. The material of the light adjustment reflector can be the same as that of the light scattering particles of the covering member 15. A gas such as nitrogen or oxygen may be used as the light adjustment reflector. The light adjustment member 30 may contain both light scattering particles and a gas. The light adjustment member 30 may be composed of a single layer, or may be composed of a laminate of multiple layers.

The light adjustment member 30 is disposed above the light source 10. As shown in FIG. 4, the light adjustment member 30 and the light source 10 overlap in a 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 to reduce uneven brightness on the light-emitting surface of the light-emitting module 100.

The light adjustment member 30 is disposed on the first translucent member 21 via the second translucent member 22. In a plan view, the light adjustment member 30, the second translucent member 22, and the first translucent member 21 overlap. By positioning the light adjustment member 30 on the first translucent member 21, it is possible to prevent the area directly above the first translucent member 21 (the area surrounding the light source 10) from becoming too bright, and it is possible to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

The light adjustment member 30 may further have a plurality of through holes 32. The through holes 32 penetrate the light adjustment member 30 from the upper surface to the lower surface. The second light-transmissive member 22 is exposed in the through holes 32. Light from the light source 10 is more likely to pass through the through holes 32 than through the portions of the light adjustment member 30 where the through holes 32 are not located. The position, lateral size (diameter or width), number, etc. of the through holes 32 make it easier to adjust the brightness of the area directly above the light adjustment member 30. This makes it easier to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[Support member]
The surface light source 300 of the embodiment further includes a support member 200. The support member 200 has the above-mentioned first wiring member 40. The light emitting module 100 is disposed on the support member 200, and the support member 200 supports the light emitting module 100. The light guiding member 50 is disposed on the support member 200 with the sixth surface 52 facing an 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 disposed on the second insulating layer 48 of the first wiring member 40. The reflective member 64 is disposed on the sixth adhesive layer 63. The seventh adhesive layer 65 is disposed 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. The sixth adhesive layer 63 can be made of, for example, a resin member containing light scattering particles. For example, the same material as the resin member of the covering member 15 can be used as the resin member 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 light scattering particles of the sixth adhesive layer 63. A sheet-shaped optical transparent adhesive can be used as the sixth adhesive layer 63.

The reflecting member 64 is disposed below the light guide member 50, below the light source 10, below the first light-transmissive member 21, and below the partition groove 54. The reflecting member 64 is reflective to the light emitted by the light source 10. The reflecting member 64 can be composed of a resin member and a reflector contained in the resin member. For example, the same material as the resin member of the covering member 15 can be used as the resin member of the reflecting member 64. The same material as the light scattering particles of the covering member 15 can be used as the material of the reflector of the reflecting member 64. A gas such as nitrogen or oxygen may be used as the reflector of the reflecting member 64. The reflecting member 64 may also contain both light scattering particles and a gas as the 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 portion of the light traveling from the reflective member 64 to the sixth adhesive layer 63 is more likely to be totally reflected at the interface between the reflective member 64 and the sixth adhesive layer 63. This makes it possible to reduce the amount of light that escapes downward from the light-emitting module 100, thereby improving the light extraction efficiency of the light-emitting module 100.

The refractive index of the reflector of the reflecting member 64 is preferably lower than the refractive index of the resin member of the reflecting member 64. By making the refractive index of the reflector of the reflecting member 64 lower than the refractive index of the resin member of the reflecting member 64, a portion of the light from the light source 10 that is incident on the reflecting member 64 is more likely to be totally reflected at the interface between the resin member of the reflecting member 64 and the reflector of the reflecting member 64. This reduces the amount of light that escapes downward from the reflecting member 64, improving the light extraction efficiency of the light-emitting module 100.

When the refractive index of the reflector of the reflecting member 64 is lower than the refractive index of the resin member of the reflecting member 64, it is preferable that the refractive index of the resin member of the reflecting member 64 is higher than the refractive index of the light-guiding member 50. This makes it easier to increase the refractive index difference between the resin member of the reflecting member 64 and the reflector of the reflecting member 64, and makes it easier for a portion of the light from the light source 10 that is incident on the reflecting member 64 to be totally reflected at the interface between the resin member of the reflecting member 64 and the reflector of the reflecting member 64.

The seventh adhesive layer 65 is disposed between the reflecting member 64 and the sixth surface 52 of the light guide member 50, and bonds the reflecting member 64 and the light guide member 50. The light source 10 is disposed on the seventh adhesive layer 65 in the housing portion 53 of the light guide member 50. The seventh adhesive layer 65 can be formed, for example, of a resin member containing light scattering particles. For example, the same material as the resin member of the covering member 15 can be used as the resin member 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 light scattering particles of the seventh adhesive layer 65. For example, a sheet-shaped optical transparent adhesive can be used as the seventh adhesive layer 65.

The refractive index of the resin member of the seventh adhesive layer 65 is preferably lower than that of the light-guiding member 50. By making the refractive index of the resin member of the seventh adhesive layer 65 lower than that of the light-guiding member 50, a portion of the light traveling from the light-guiding member 50 to the seventh adhesive layer 65 is more likely to be totally reflected at the interface between the light-guiding member 50 and the seventh adhesive layer 65. This reduces the amount of light that escapes downward from the light-emitting module 100, 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 that of the first translucent member 21. By making the refractive index of the resin member of the seventh adhesive layer 65 lower than that of the first translucent member 21, a portion of the light traveling from the first translucent member 21 to the seventh adhesive layer 65 is more likely to be totally reflected at the interface between the first translucent member 21 and the seventh adhesive layer 65. This reduces the amount of light that escapes downward from the light-emitting module 100, improving the light extraction efficiency of the light-emitting module 100.

The support member 200 further includes a connection member 67. The connection member 67 is conductive. The connection member 67 includes, for example, a resin and metal particles contained in the resin. For example, an epoxy resin or a phenolic resin can be used as the resin of the connection member 67. For example, copper or silver particles can be used as the metal particles of the connection member 67.

The connection 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 disposed on the second surface 41b side of the first base material 41 on which the first wiring layer 42 is disposed, 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 connection members 67 are arranged apart from each other in correspondence with the pair of positive and negative electrodes 12 of the light source 10. Of the pair of connection members 67, a first portion 67a of one connection member 67 is connected to the positive electrode 12 below the light source 10, and a second portion 67b of the other connection member 67 is connected to the negative electrode 12 below the light source 10. The electrodes 12 of the light source 10 are electrically connected to the first wiring layer 42 of the first wiring member 40 via the connection members 67.

As shown in FIG. 6, the light-emitting module 100 may be disposed on the second surface 41b side of the first substrate 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. 5.

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

In the embodiment of FIG. 6, the light source 10 and the light guide member 50 are arranged on the second surface 41b side of the first substrate 41, and the first wiring layer 42 is connected to the second wiring layer 72 of the second wiring member 70 via the conductive member 80. In the embodiment 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 surface light sources:

[Item 1]
a first wiring member including a first base material having a first surface and a second surface located opposite to 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 one of the first surface side and the second surface side on which the light source is disposed;
a second wiring member including: a second base having a third surface and a fourth surface located opposite 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 a surface facing 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, 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 portion exposed from the protective layer and located between the connection portion and the covering portion;
having
The first insulating member is disposed at a position overlapping the first exposed portion and the conductive member in a planar view.
[Item 2]
the second wiring layer includes a first metal layer and a second metal layer covering a surface of the first metal layer and made of a material different from that of 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 by the protective layer on a surface of the second wiring layer opposite to a surface facing the third surface,
the first exposed portion and the connection portion are a surface of the second metal layer on a surface of the second wiring layer opposite to a surface facing the third surface,
2. The surface light source according to item 1, wherein the first insulating member is disposed at a position that further overlaps the protective layer in a plan view.
[Item 3]
3. The surface light source according to item 2, wherein the second metal layer contains a metal material having a higher rigidity than the metal material contained in the first metal layer.
[Item 4]
4. The surface light source according to item 3, wherein the metal material contained in the second metal layer is nickel.
[Item 5]
Item 5. The surface light source according to any one of items 2 to 4, wherein the second metal layer is thinner than the first metal layer.
[Item 6]
a surface of the second wiring layer opposite to a surface facing the third surface, the surface being a second exposed portion exposed from the protective layer, the second exposed portion being a surface of the second metal layer;
the covering portion is located between the first exposed portion and the second exposed portion,
Item 6. The surface light source according to any one of items 2 to 5, further comprising a second insulating member disposed on the fourth surface side and disposed at a position overlapping the second exposed portion in a plan view.
[Item 7]
7. The surface light source according to item 6, wherein the first insulating member is thinner than the second insulating member.
[Item 8]
The thickness of the first insulating member is 10 μm or more and 25 μm or less,
Item 8. The surface light source according to item 7, wherein the second insulating member has a thickness of 100 μm or more and 500 μm or less.
[Item 9]
Item 9. The surface light source according to any one of items 6 to 8, wherein an area of the first insulating member is smaller than an area of the second insulating member in a plan view.
[Item 10]
Item 10. The surface 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.
[Item 11]
Item 11. The surface light source according to any one of items 1 to 10, wherein the first insulating member has a thickness greater than a thickness of the protective layer.
[Item 12]
Item 12. The surface light source according to any one of items 1 to 11, wherein the first insulating member has a rigidity higher than a rigidity of the protective layer.
[Item 13]
Item 11. The surface light source according to any one of items 6 to 10, wherein a thickness of the protective layer is smaller than a thickness of the second insulating member.

The above describes the embodiments of the present invention with reference to specific examples. However, the present invention is not limited to these specific examples. All forms that a person skilled in the art can implement by appropriately modifying the design based on the above-described embodiments of the present invention also fall within the scope of the present invention as long as they include the gist of the present invention. In addition, a person skilled in the art can come up with various modifications and alterations within the scope of the concept of the present invention, and these modifications and alterations also fall within the scope of the present invention.

10...light source, 21...first translucent member, 22...second translucent member, 30...light adjustment member, 40...first wiring member, 41...first substrate, 41a...first surface, 41b...second surface, 42...first wiring layer, 45...third wiring layer, 46...wiring connection portion, 50...light guide member, 64...reflective member, 67...connection member, 70...second wiring member, 71...second substrate, 71a...third surface, 71b...third 4 surfaces, 72...second wiring layer, 72a1...connection portion, 72a2...first exposed portion, 72a3...covering portion, 72a4...second exposed portion, 73...first 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...surface light source, 400...light emitting surface, 500...wiring member

Claims (11)

a first wiring member including a first base material having a first surface and a second surface located opposite to 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 one of the first surface side and the second surface side on which the light source is disposed;
a second wiring member including: a second base having a third surface and a fourth surface located opposite 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 a surface facing 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, 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 portion exposed from the protective layer and located between the connection portion and the covering portion;
having
the first insulating member is disposed at a position overlapping the first exposed portion and the conductive member in a plan view ,
The second wiring layer further includes a first metal layer and a second metal layer covering a surface of the first metal layer and made of a material different from that of 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 by the protective layer on a surface of the second wiring layer opposite to a surface facing the third surface,
the first exposed portion and the connection portion are a surface of the second metal layer on a surface of the second wiring layer opposite to a surface facing the third surface,
the first insulating member is disposed at a position overlapping the protective layer in a plan view,
a surface of the second wiring layer opposite to a surface facing the third surface includes a second exposed portion exposed from the protective layer, the second exposed portion being a surface of the second metal layer;
the covering portion is located between the first exposed portion and the second exposed portion,
The surface light source further includes a second insulating member disposed on the fourth surface side and positioned so as to overlap the second exposed portion in a plan view . The surface light source according to claim 1 , wherein the second metal layer includes a metal material having a higher rigidity than the metal material included in the first metal layer. The surface light source according to claim 2 , wherein the metal material contained in the second metal layer is nickel. The surface light source according to claim 1 , wherein the second metal layer is thinner than the first metal layer. The surface light source according to claim 1 , 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 surface light source according to claim 5 , wherein the second insulating member has a thickness of 100 μm or more and 500 μm or less. The surface light source according to claim 1 , wherein an area of the first insulating member is smaller than an area of the second insulating member in a plan view. The surface light source according to claim 1 , wherein the second insulating member has a higher rigidity than the first insulating member. 7. The surface light source according to claim 1 , wherein the first insulating member is thicker than the protective layer. 7. The surface light source according to claim 1 , wherein the first insulating member has a rigidity higher than a rigidity of the protective layer. The surface light source according to claim 1 , wherein the protective layer is thinner than the second insulating member.

Images