JP7477782B2 - Surface Light Source - Google Patents

Surface Light Source Download PDF

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JP7477782B2
JP7477782B2 JP2022033667A JP2022033667A JP7477782B2 JP 7477782 B2 JP7477782 B2 JP 7477782B2 JP 2022033667 A JP2022033667 A JP 2022033667A JP 2022033667 A JP2022033667 A JP 2022033667A JP 7477782 B2 JP7477782 B2 JP 7477782B2
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light
light source
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JP2023128961A (en
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大典 岩倉
康志 岡本
政樹 米澤
裕樹 渋谷
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Nichia Corp
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Nichia Corp
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Description

本開示は、面状光源に関する。 This disclosure relates to a surface light source.

それぞれがＬＥＤを含む複数の光源を二次元に配置した直下型の発光装置が知られている。例えば下記の特許文献１、２は、複数の光源が実装された基板と、基板上に配置された導光板とを含む発光装置を開示している。特許文献１の図６および図７Ａは、導光板に複数の貫通孔を設け、それら貫通孔の内部に位置するように光源を基板上に配置した構成を開示している。特許文献２の図３は、導光板の貫通孔の内部にＬＥＤを配置し、ＬＥＤを覆うようにして貫通孔を接着部材で充填した構成を開示している。 Direct-type light-emitting devices in which multiple light sources, each of which includes an LED, are arranged two-dimensionally are known. For example, the following Patent Documents 1 and 2 disclose light-emitting devices that include a substrate on which multiple light sources are mounted and a light guide plate arranged on the substrate. Figures 6 and 7A of Patent Document 1 disclose a configuration in which multiple through-holes are provided in the light guide plate, and light sources are arranged on the substrate so as to be located inside the through-holes. Figure 3 of Patent Document 2 discloses a configuration in which LEDs are arranged inside the through-holes of the light guide plate, and the through-holes are filled with an adhesive member so as to cover the LEDs.

特開２０１１－２１１０８５号公報JP 2011-211085 A 韓国公開特許第１０－２００９－０１１７４１９号公報Korean Patent Publication No. 10-2009-0117419

面状光源の分野、特に薄型の直下型バックライトの分野では、輝度ムラ低減の要求がある。 In the field of surface light sources, especially in the field of thin direct-type backlights, there is a demand for reduced brightness unevenness.

本開示の実施形態による面状光源は、上面を有する配線基板と、前記配線基板の前記上面側に位置する導光部材であって、第１主面、前記第１主面の反対側に位置する第２主面、および、前記第１主面から前記第２主面に達する第１貫通孔を規定する少なくとも１つの内側面を有する導光部材と、前記第１貫通孔内に位置し、前記配線基板に接続された光源と、前記第１貫通孔内において前記光源を覆う第１透光性部材であって、前記第１貫通孔の前記内側面に部分的に接する第１透光性部材とを備え、前記第１透光性部材の表面は、前記第１貫通孔内に、前記第１貫通孔の前記内側面および前記配線基板の前記上面から離れている第１領域を含む。 A surface light source according to an embodiment of the present disclosure includes a wiring board having an upper surface, a light guide member located on the upper surface side of the wiring board, the light guide member having a first main surface, a second main surface located opposite the first main surface, and at least one inner side surface defining a first through hole extending from the first main surface to the second main surface, a light source located in the first through hole and connected to the wiring board, and a first translucent member covering the light source in the first through hole, the first translucent member being in partial contact with the inner side surface of the first through hole, and the surface of the first translucent member includes a first region within the first through hole that is away from the inner side surface of the first through hole and the upper surface of the wiring board.

本開示の実施形態によれば、輝度ムラを効果的に低減し得る面状光源を提供できる。 According to an embodiment of the present disclosure, a surface light source that can effectively reduce brightness unevenness can be provided.

本開示の実施形態による面状光源の外観の一例を示す模式的な上面図である。FIG. 2 is a schematic top view illustrating an example of the appearance of a surface light source according to an embodiment of the present disclosure. 図１に示すII－II線断面図である。2 is a cross-sectional view taken along line II-II of FIG. 1. 図２中に破線で示す円に囲まれた領域を拡大して示す模式的な断面図である。3 is a schematic cross-sectional view showing an enlarged area surrounded by a circle indicated by a dashed line in FIG. 2. 第１貫通孔内の空隙の形状の一例を示す模式的な断面図である。5 is a schematic cross-sectional view showing an example of the shape of a gap in a first through hole. FIG. 第１貫通孔内の空隙の形状の他の一例を示す模式的な断面図である。11 is a schematic cross-sectional view showing another example of the shape of a gap in a first through hole. FIG. 第１貫通孔内の空隙の配置の一例を示す模式的な上面図である。FIG. 11 is a schematic top view showing an example of an arrangement of gaps in a first through hole. 第１貫通孔内の空隙の配置の他の一例を示す模式的な上面図である。13 is a schematic top view showing another example of the arrangement of gaps in the first through hole. FIG. 本開示の実施形態による面状光源に適用可能な光源の外観の一例を示す模式的な底面斜視図である。1 is a schematic bottom perspective view illustrating an example of the appearance of a light source applicable to a surface light source according to an embodiment of the present disclosure. 図８に示す平面Σで光源を切断したときに現れる断面を模式的に示す図である。9 is a diagram showing a schematic cross section that appears when the light source is cut along a plane Σ shown in FIG. 8 . 本実施形態による面状光源の例示的な製造方法を説明するための模式的な断面図である。5A to 5C are schematic cross-sectional views for explaining an exemplary method for manufacturing the surface light source according to the present embodiment. 本実施形態による面状光源の例示的な製造方法を説明するための模式的な図である。5A to 5C are schematic diagrams for explaining an exemplary method for manufacturing the surface light source according to the present embodiment. 本実施形態による面状光源の例示的な製造方法を説明するための模式的な図である。5A to 5C are schematic diagrams for explaining an exemplary method for manufacturing the surface light source according to the present embodiment. 本実施形態による面状光源の例示的な製造方法を説明するための模式的な図である。5A to 5C are schematic diagrams for explaining an exemplary method for manufacturing the surface light source according to the present embodiment. 本実施形態による面状光源の例示的な製造方法を説明するための模式的な図である。5A to 5C are schematic diagrams for explaining an exemplary method for manufacturing the surface light source according to the present embodiment. 本実施形態による面状光源の例示的な製造方法を説明するための模式的な断面図である。5A to 5C are schematic cross-sectional views for explaining an exemplary method for manufacturing the surface light source according to the present embodiment. 本実施形態による面状光源の例示的な製造方法を説明するための模式的な断面図である。5A to 5C are schematic cross-sectional views for explaining an exemplary method for manufacturing the surface light source according to the present embodiment.

以下、図面を参照しながら、本開示の実施形態を詳細に説明する。以下の実施形態は、例示であり、本開示による面状光源は、以下の実施形態に限られない。例えば、以下の実施形態で示される数値、形状、材料、工程、その工程の順序などは、あくまでも一例であり、技術的に矛盾が生じない限りにおいて種々の改変が可能である。以下に説明する各実施形態は、あくまでも例示であり、技術的に矛盾が生じない限りにおいて種々の組み合わせが可能である。 Below, the embodiments of the present disclosure will be described in detail with reference to the drawings. The following embodiments are merely examples, and the surface light source according to the present disclosure is not limited to the following embodiments. For example, the numerical values, shapes, materials, processes, and the order of the processes shown in the following embodiments are merely examples, and various modifications are possible as long as no technical contradictions arise. Each embodiment described below is merely an example, and various combinations are possible as long as no technical contradictions arise.

図面が示す構成要素の寸法、形状などは、分かりやすさのために誇張されている場合があり、実際の面状光源における寸法、形状および構成要素間の大小関係を反映していない場合がある。また、図面が過度に複雑になることを避けるために、一部の要素の図示を省略することがある。なお、切断面のみを示す端面図を断面図として示す場合がある。 The dimensions and shapes of components shown in the drawings may be exaggerated for clarity and may not reflect the dimensions, shape, and size relationships between components in an actual surface light source. Also, to avoid overly complicating the drawings, some elements may be omitted. Note that end views showing only the cut surface may be shown as cross-sectional views.

以下の説明において、実質的に同じ機能を有する構成要素は共通の参照符号で示し、説明を省略することがある。以下の説明では、特定の方向または位置を示す用語（例えば、「上」、「下」、「右」、「左」およびそれらの用語を含む別の用語）を用いる場合がある。しかしながら、それらの用語は、参照した図面における相対的な方向または位置を分かりやすさのために用いているに過ぎない。参照した図面における「上」、「下」などの用語による相対的な方向または位置の関係が同一であれば、本開示以外の図面、実際の製品、製造装置などにおいて、参照した図面と同一の配置でなくてもよい。本開示において「平行」とは、特に他の言及がない限り、２つの直線、辺、面などが０°から±５°程度の範囲にある場合を含む。また、本開示において「垂直」または「直交」とは、特に他の言及がない限り、２つの直線、辺、面などが９０°から±５°程度の範囲にある場合を含む。 In the following description, components having substantially the same functions are indicated by common reference symbols, and descriptions may be omitted. In the following description, terms indicating a specific direction or position (for example, "up", "down", "right", "left" and other terms including these terms) may be used. However, these terms are merely used for the sake of clarity of the relative direction or position in the referenced drawings. As long as the relationship of the relative direction or position by terms such as "up" and "down" in the referenced drawings is the same, the arrangement in drawings other than this disclosure, actual products, manufacturing equipment, etc. may not be the same as in the referenced drawings. In this disclosure, "parallel" includes cases where two straight lines, sides, faces, etc. are in the range of about 0° to ±5°, unless otherwise specified. In addition, in this disclosure, "perpendicular" or "orthogonal" includes cases where two straight lines, sides, faces, etc. are in the range of about 90° to ±5°, unless otherwise specified.

（面状光源の実施形態）
図１は、本開示の実施形態による面状光源の外観の一例を示す。図１には、説明の便宜のために、互いに直交するＸ方向、Ｙ方向およびＺ方向を示す矢印をあわせて図示している。本開示の他の図面においてもこれらの方向を示す矢印を図示することがある。図１に示す面状光源１０００は、概略的には、配線基板１１００と、配線基板１１００に支持された導光部材１２００とを含む。 (Embodiments of Planar Light Source)
Fig. 1 shows an example of the appearance of a surface light source according to an embodiment of the present disclosure. For convenience of explanation, Fig. 1 also shows arrows indicating mutually orthogonal X, Y, and Z directions. Arrows indicating these directions may also be shown in other drawings of the present disclosure. The surface light source 1000 shown in Fig. 1 generally includes a wiring board 1100 and a light guide member 1200 supported by the wiring board 1100.

配線基板１１００は、例えばフレキシブルプリント基板をその一部に含み得る。図１に例示する構成において、配線基板１１００は、導光部材１２００の配置されている領域から延びる延伸部１１０ｔを含んでいる。この例では、延伸部１１０ｔの数は、４つである。延伸部１１０ｔのそれぞれは、外部の電源などへの接続のための端子を有する。 The wiring board 1100 may include, for example, a flexible printed circuit board as a part thereof. In the configuration illustrated in FIG. 1, the wiring board 1100 includes an extension portion 110t extending from the area where the light-guiding member 1200 is arranged. In this example, the number of extension portions 110t is four. Each of the extension portions 110t has a terminal for connection to an external power source or the like.

導光部材１２００は、配線基板１１００の上面１１００ａ側に配置され、全体として概ね板状の形状を有する。導光部材１２００は、配線基板１１００の上面１１００ａの法線方向（ここでは図のＺ方向に一致）に見た上面視において、典型的には、矩形状の外形を有する。図１に示す例において、導光部材１２００は、Ｙ方向と比較してＸ方向に長い長方形状を有している。すなわち、ここでは、導光部材１２００の長方形状の長辺は、Ｘ方向に平行であり、短辺は、Ｙ方向に平行である。後述するように、導光部材１２００と、配線基板１１００との間には、導光部材１２００を配線基板１１００の上面１１００ａに固定するための接着層などの他の部材が介在され得る。 The light guide member 1200 is disposed on the upper surface 1100a side of the wiring board 1100 and has a generally plate-like shape as a whole. The light guide member 1200 typically has a rectangular shape in a top view seen in the normal direction of the upper surface 1100a of the wiring board 1100 (here, the Z direction in the figure). In the example shown in FIG. 1, the light guide member 1200 has a rectangular shape that is longer in the X direction than in the Y direction. That is, here, the long side of the rectangular shape of the light guide member 1200 is parallel to the X direction, and the short side is parallel to the Y direction. As will be described later, between the light guide member 1200 and the wiring board 1100, other members such as an adhesive layer for fixing the light guide member 1200 to the upper surface 1100a of the wiring board 1100 may be interposed.

図１に例示する構成において、導光部材１２００は、それぞれがＸ方向またはＹ方向に延びる複数の溝部２０ｇを有する。また、導光部材１２００は、複数の貫通孔２０ｈ（以下、「第１貫通孔２０ｈ」と呼ぶ）を有する。図１中に拡大して模式的に示すように、各第１貫通孔２０ｈ内には、光源１３０が配置される。すなわち、面状光源１０００は、複数の光源１３０を含んでいる。なお、図１に示す例では、第１貫通孔２０ｈを覆う形状の光調整部材１４０が導光部材１２００の上面１２００ａ上に配置されている。 In the configuration illustrated in FIG. 1, the light guide member 1200 has a plurality of grooves 20g each extending in the X direction or the Y direction. The light guide member 1200 also has a plurality of through holes 20h (hereinafter referred to as "first through holes 20h"). As shown enlarged and schematic in FIG. 1, a light source 130 is disposed in each of the first through holes 20h. That is, the surface light source 1000 includes a plurality of light sources 130. In the example illustrated in FIG. 1, a light adjustment member 140 shaped to cover the first through holes 20h is disposed on the upper surface 1200a of the light guide member 1200.

図１中に拡大して示すように、複数の第１貫通孔２０ｈのそれぞれは、溝部２０ｇによって四方を囲まれる。言い換えれば、複数の溝部２０ｇは、それぞれが１つの第１貫通孔２０ｈを有する複数の単位に導光部材１２００を区画している。 As shown enlarged in FIG. 1, each of the multiple first through holes 20h is surrounded on all four sides by a groove portion 20g. In other words, the multiple groove portions 20g divide the light-guiding member 1200 into multiple units, each of which has one first through hole 20h.

図１に例示する面状光源１０００は、それぞれが光源１３０を含む複数の単位構造１００の集合体であるといえる。面状光源１０００は、このような単位構造１００が複数の行および列に配列された構成を有する。各単位構造１００は、それ自身が発光可能な構造を有する。図１に示す例では、面状光源１０００は、２５行４０列に配列された合計１０００個の単位構造１００を含む。本開示の実施形態において、面状光源１０００中の単位構造１００の数およびそれらの配置は、任意である。以下、単位構造１００を発光領域１００と呼ぶことがある。 The surface light source 1000 illustrated in FIG. 1 can be said to be an assembly of a plurality of unit structures 100, each of which includes a light source 130. The surface light source 1000 has a configuration in which such unit structures 100 are arranged in a plurality of rows and columns. Each unit structure 100 has a structure capable of emitting light by itself. In the example illustrated in FIG. 1, the surface light source 1000 includes a total of 1000 unit structures 100 arranged in 25 rows and 40 columns. In the embodiment of the present disclosure, the number of unit structures 100 in the surface light source 1000 and their arrangement are arbitrary. Hereinafter, the unit structures 100 may be referred to as light-emitting regions 100.

図２は、面状光源１０００中の発光領域１００を導光部材１２００の上面１２００ａに垂直に切断したときの断面を模式的に示す。図２は、図１に示すII－II線断面図に相当する。図２に示すように、発光領域１００は、配線基板１１００の一部と、導光部材１２０と、光源１３０と、光調整部材１４０とを含む。導光部材１２０は、図１に示す導光部材１２００の一部であり、ここでは、導光部材１２０と配線基板１１００との間に接着層（後述の第２接着層１８０）が配置されている。 Figure 2 shows a schematic cross section of the light-emitting region 100 in the surface light source 1000 when cut perpendicularly to the upper surface 1200a of the light-guiding member 1200. Figure 2 corresponds to the cross section taken along line II-II in Figure 1. As shown in Figure 2, the light-emitting region 100 includes a part of the wiring board 1100, the light-guiding member 120, the light source 130, and the light adjustment member 140. The light-guiding member 120 is a part of the light-guiding member 1200 shown in Figure 1, and here, an adhesive layer (second adhesive layer 180 described below) is disposed between the light-guiding member 120 and the wiring board 1100.

導光部材１２０は、上面１２０ａ（第１主面）と、上面１２０ａの反対側に位置する下面１２０ｂ（第２主面）とを有する。導光部材１２０の下面１２０ｂは、導光部材１２０の２つの主面のうち、配線基板１１００の上面１１００ａのより近くに位置する側の面である。 The light-guiding member 120 has an upper surface 120a (first main surface) and a lower surface 120b (second main surface) located opposite the upper surface 120a. The lower surface 120b of the light-guiding member 120 is the surface located closer to the upper surface 1100a of the wiring substrate 1100, of the two main surfaces of the light-guiding member 120.

導光部材１２０は、上面視における中央付近に、導光部材１２０の上面１２０ａから下面１２０ｂまで達する第１貫通孔２０ｈを有する。第１貫通孔２０ｈは、導光部材１２０の上面１２０ａに位置する開口２０ａと、下面１２０ｂに位置する開口２０ｂとを含む。 The light-guiding member 120 has a first through-hole 20h near the center when viewed from above, which reaches from the upper surface 120a to the lower surface 120b of the light-guiding member 120. The first through-hole 20h includes an opening 20a located on the upper surface 120a of the light-guiding member 120 and an opening 20b located on the lower surface 120b.

導光部材１２０は、第１貫通孔２０ｈの形状を規定する少なくとも１つの内側面を有する。図１において破線で描かれているように、ここでは、第１貫通孔２０ｈの２つの開口２０ａ、２０ｂは、上面視において円形状を有する。したがって、この例では、１つの内側面２０ｃが第１貫通孔２０ｈを規定している。第１貫通孔２０ｈを規定する内側面の数は、３以上であってもよい。例えば第１貫通孔２０ｈの開口２０ａ、２０ｂが多角形状を有する場合、第１貫通孔２０ｈは、３以上の内側面によって規定され得る。 The light guide member 120 has at least one inner side surface that defines the shape of the first through hole 20h. As depicted by dashed lines in FIG. 1, here, the two openings 20a, 20b of the first through hole 20h have a circular shape when viewed from above. Therefore, in this example, one inner side surface 20c defines the first through hole 20h. The number of inner sides that define the first through hole 20h may be three or more. For example, when the openings 20a, 20b of the first through hole 20h have a polygonal shape, the first through hole 20h may be defined by three or more inner sides.

上述したように、第１貫通孔２０ｈ内には光源１３０が位置する。図２に模式的に示すように、光源１３０は、少なくとも発光素子３２をその一部に含む。発光素子３２は、例えば青色の光を出射する発光ダイオード（青色ＬＥＤ）であり、後に図面を参照しながら詳しく説明するように、下面側に一対の電極を有する。光源１３０は、第１貫通孔２０ｈ内の開口２０ｂ側において配線基板１１００に接続される。 As described above, the light source 130 is located in the first through hole 20h. As shown in FIG. 2, the light source 130 includes at least a light-emitting element 32 as a part thereof. The light-emitting element 32 is, for example, a light-emitting diode (blue LED) that emits blue light, and has a pair of electrodes on the underside, as will be described in detail later with reference to the drawings. The light source 130 is connected to the wiring board 1100 on the opening 20b side in the first through hole 20h.

図２に示すように、発光領域１００は、導光部材１２０の第１貫通孔２０ｈ内に位置する第１透光性部材１５０をさらに含んでいる。第１透光性部材１５０は、第１貫通孔２０ｈ内において光源１３０を覆う。図２に示す例では、第１透光性部材１５０の上面１５０ａは、概ね平坦であり、かつ、導光部材１２０の上面１２０ａに整合している。図２に例示する構成において、第１透光性部材１５０の上面１５０ａおよび導光部材１２０の上面１２０ａの全体は、発光領域１００の発光面を構成するといってよい。 2, the light-emitting region 100 further includes a first translucent member 150 located in the first through-hole 20h of the light-guiding member 120. The first translucent member 150 covers the light source 130 in the first through-hole 20h. In the example shown in FIG. 2, the upper surface 150a of the first translucent member 150 is generally flat and is aligned with the upper surface 120a of the light-guiding member 120. In the configuration shown in FIG. 2, the upper surface 150a of the first translucent member 150 and the upper surface 120a of the light-guiding member 120 as a whole constitute the light-emitting surface of the light-emitting region 100.

図３は、図２中に破線で示す円ＣＱに囲まれた領域を拡大して示す。本開示の実施形態において、第１透光性部材１５０は、第１貫通孔２０ｈ内の空間のうち光源１３０以外の領域の大部分を占有し得るものの、第１貫通孔２０ｈ内の空間のうち光源１３０以外の領域の全体を占有することはない。 Figure 3 shows an enlarged view of the area surrounded by the dashed circle CQ in Figure 2. In an embodiment of the present disclosure, the first light-transmissive member 150 may occupy most of the area of the space in the first through-hole 20h other than the light source 130, but does not occupy the entire area of the space in the first through-hole 20h other than the light source 130.

図３に模式的に示すように、第１透光性部材１５０は、第１貫通孔２０ｈの内側面２０ｃの全体に接してはおらず、内側面２０ｃに部分的に接する。言い換えれば、第１透光性部材１５０の表面は、第１貫通孔２０ｈの内側面２０ｃに接していない領域を含んでいる。ここで、本明細書において、第１透光性部材１５０の「表面」とは、第１透光性部材１５０の外形を規定する、第１透光性部材１５０の外部に位置する他の部材または媒質との間の境界のうち、導光部材１２０の上面１２０ａ側に位置する開口２０ａの内側に表れた上面１５０ａを除いた部分を指す。 As shown in FIG. 3, the first light-transmissive member 150 does not contact the entire inner surface 20c of the first through hole 20h, but only partially contacts the inner surface 20c. In other words, the surface of the first light-transmissive member 150 includes an area that does not contact the inner surface 20c of the first through hole 20h. Here, in this specification, the "surface" of the first light-transmissive member 150 refers to the boundary between the first light-transmissive member 150 and other members or media located outside the first light-transmissive member 150, which defines the outer shape of the first light-transmissive member 150, excluding the upper surface 150a that appears on the inside of the opening 20a located on the upper surface 120a side of the light-guiding member 120.

すなわち、面状光源１０００中の発光領域１００は、第１貫通孔２０ｈ内に、導光部材１２０の材料および第１透光性部材１５０の材料のいずれにも占有されない空隙ＧＰを有している。空隙ＧＰは、第１貫通孔２０ｈの、導光部材１２０の上面１２０ａ側の開口２０ａよりも下面１２０ｂ側の開口２０ｂの近くに位置し得る。本開示の典型的な実施形態において、面状光源１０００は、第１貫通孔２０ｈの下側の隅部に１以上の空隙ＧＰを有する少なくとも１つの発光領域１００を含む。 That is, the light-emitting region 100 in the surface light source 1000 has a gap GP in the first through hole 20h that is not occupied by either the material of the light-guiding member 120 or the material of the first light-transmissive member 150. The gap GP may be located closer to the opening 20b on the lower surface 120b side of the first through hole 20h than the opening 20a on the upper surface 120a side of the light-guiding member 120. In a typical embodiment of the present disclosure, the surface light source 1000 includes at least one light-emitting region 100 having one or more gaps GP in the lower corner of the first through hole 20h.

本開示の実施形態では、第１透光性部材１５０の表面は、第１貫通孔２０ｈ内に、第１貫通孔２０ｈの内側面２０ｃ、配線基板１１００の上面１１００ａのいずれからも離れている第１領域Ｒ１を含んでいる。第１透光性部材１５０の表面の一部である第１領域Ｒ１は、第１貫通孔２０ｈの内側面２０ｃから配線基板１１００の上面１１００ａと平行な第１方向（例えばＸ方向）に離れており、かつ、配線基板１１００の上面１１００ａからも、配線基板１１００の上面１１００ａと垂直な第２方向（例えばＺ方向）に離れている。別の言い方をすれば、図３に示す例において、第１領域Ｒ１は、第１貫通孔２０ｈの内側面２０ｃと第１方向に対向し、かつ、第２接着層１８０の上面１８０ａと第２方向に対向している。第１領域Ｒ１が、第１貫通孔２０ｈの内側面２０ｃと第１方向に対向し、かつ、配線基板１１００の上面１１００ａと第２方向に対向することもあり得る。すなわち、第１領域Ｒ１は、第１貫通孔２０ｈの内側面２０ｃおよび配線基板１１００の上面１１００ａのいずれとも接していない。 In the embodiment of the present disclosure, the surface of the first translucent member 150 includes a first region R1 in the first through hole 20h that is separated from both the inner side surface 20c of the first through hole 20h and the upper surface 1100a of the wiring board 1100. The first region R1, which is a part of the surface of the first translucent member 150, is separated from the inner side surface 20c of the first through hole 20h in a first direction (e.g., X direction) parallel to the upper surface 1100a of the wiring board 1100, and is also separated from the upper surface 1100a of the wiring board 1100 in a second direction (e.g., Z direction) perpendicular to the upper surface 1100a of the wiring board 1100. In other words, in the example shown in FIG. 3, the first region R1 faces the inner side surface 20c of the first through hole 20h in the first direction, and faces the upper surface 180a of the second adhesive layer 180 in the second direction. The first region R1 may face the inner surface 20c of the first through hole 20h in the first direction and face the upper surface 1100a of the wiring substrate 1100 in the second direction. That is, the first region R1 does not contact either the inner surface 20c of the first through hole 20h or the upper surface 1100a of the wiring substrate 1100.

図３に示す例において、第１貫通孔２０ｈ内の空隙ＧＰは、導光部材１２０の第１貫通孔２０ｈの内側面２０ｃ、第２接着層１８０の上面１８０ａおよび第１透光性部材１５０の表面の第１領域Ｒ１に囲まれた空間である。空隙ＧＰの内部には、第１透光性部材１５０の材料とは異なる媒質（例えば空気）が位置する。そのため、光源１３０から出射された光のうち、第１透光性部材１５０の表面の特に第１領域Ｒ１に入射した成分の少なくとも一部は、第１領域Ｒ１の位置で反射され得る。すなわち、光源１３０から出射されて第１透光性部材１５０内を進行する光の一部を、第１透光性部材１５０と、配線基板１１００の上面１１００ａ近傍に位置する空隙ＧＰとの界面で反射させることができる。 3, the gap GP in the first through hole 20h is a space surrounded by the inner surface 20c of the first through hole 20h of the light-guiding member 120, the upper surface 180a of the second adhesive layer 180, and the first region R1 of the surface of the first translucent member 150. Inside the gap GP, a medium (e.g., air) different from the material of the first translucent member 150 is located. Therefore, at least a portion of the component of the light emitted from the light source 130 that is incident on the surface of the first translucent member 150, particularly the first region R1, can be reflected at the position of the first region R1. That is, a portion of the light emitted from the light source 130 and traveling through the first translucent member 150 can be reflected at the interface between the first translucent member 150 and the gap GP located near the upper surface 1100a of the wiring board 1100.

第１透光性部材１５０内を進行する光の一部を、第１透光性部材１５０と、空隙ＧＰとの界面で反射させることにより、第１貫通孔２０ｈ内で第１貫通孔２０ｈの上方（例えば開口２０ａの近傍）に向かう光を増大させ得る。その結果、発光領域１００の発光面において、光源１３０の光軸上の領域と、その周囲の領域との間の輝度差を低減することが可能になる。ＬＥＤに代表される発光素子から発せられる光の強度は、光軸上において最も大きい傾向にある。光源１３０の光軸上の領域と、その周囲の領域との間の輝度差が低減されることにより、発光領域１００の発光面において、光源１３０の光軸の直上から外側に向かっての輝度変化をなだらかにすることができる。言い換えれば、発光面の輝度ムラを低減し得る。 By reflecting a portion of the light traveling through the first translucent member 150 at the interface between the first translucent member 150 and the gap GP, the amount of light traveling toward the upper side of the first through hole 20h (for example, near the opening 20a) in the first through hole 20h can be increased. As a result, it is possible to reduce the luminance difference between the area on the optical axis of the light source 130 and the surrounding area on the light-emitting surface of the light-emitting region 100. The intensity of light emitted from a light-emitting element, such as an LED, tends to be greatest on the optical axis. By reducing the luminance difference between the area on the optical axis of the light source 130 and the surrounding area, the luminance change from directly above the optical axis of the light source 130 to the outside on the light-emitting surface of the light-emitting region 100 can be made smooth. In other words, the luminance unevenness of the light-emitting surface can be reduced.

なお、複数の発光領域１００の配列を含む面状光源１０００において、すべての発光領域１００が空隙ＧＰを有することは、必須ではない。空隙ＧＰを有する発光領域１００と、空隙ＧＰを有しない発光領域１００とが面状光源１０００に混在していることもあり得る。また、空隙ＧＰを有する発光領域１００の間で、空隙ＧＰの配置および形状が一致していることも必須ではない。複数の発光領域１００の間で、空隙ＧＰの配置、形状および数などが異なることもあり得る。 In addition, in a surface light source 1000 including an arrangement of a plurality of light-emitting regions 100, it is not essential that all of the light-emitting regions 100 have a gap GP. It is possible that light-emitting regions 100 having a gap GP and light-emitting regions 100 having no gap GP are mixed in the surface light source 1000. It is also not essential that the arrangement and shape of the gap GP are consistent among the light-emitting regions 100 having the gap GP. The arrangement, shape, number, etc. of the gap GP may differ among the plurality of light-emitting regions 100.

本開示の典型的な実施形態において、第１透光性部材１５０の表面のうち第１領域Ｒ１は、第１透光性部材１５０よりも小さな屈折率を有する媒質と、第１透光性部材１５０との間の境界面を構成する。空隙ＧＰの内部に位置する媒質が第１透光性部材１５０の材料よりも低い屈折率を示すことにより、第１透光性部材１５０との界面での全反射を利用して、第１貫通孔２０ｈの上方に向かう光を増大させ得る。すなわち、より効果的に発光面の輝度ムラを低減し得る。 In a typical embodiment of the present disclosure, the first region R1 of the surface of the first light-transmissive member 150 constitutes an interface between the first light-transmissive member 150 and a medium having a smaller refractive index than the first light-transmissive member 150. By making the medium located inside the gap GP exhibit a lower refractive index than the material of the first light-transmissive member 150, the light directed upward through the first through-hole 20h can be increased by utilizing total reflection at the interface with the first light-transmissive member 150. In other words, the brightness unevenness of the light-emitting surface can be more effectively reduced.

第１透光性部材１５０よりも小さな屈折率を有する媒質の典型例は、空気である。第１貫通孔２０ｈの内側面２０ｃ、配線基板１１００の上面１１００ａおよび第１透光性部材１５０の表面の第１領域Ｒ１に囲まれた空間に空気が位置することにより、空隙ＧＰの内部を他の媒質で満たした場合と比較して、空隙ＧＰの内部の媒質と、第１透光性部材１５０との間の屈折率差を拡大できる。空隙ＧＰの内部に位置する媒質は、空気に加えて、樹脂材料から発生するガスなどを含有していてもよい。 A typical example of a medium having a smaller refractive index than the first translucent member 150 is air. By having air located in the space surrounded by the inner surface 20c of the first through hole 20h, the upper surface 1100a of the wiring substrate 1100, and the first region R1 on the surface of the first translucent member 150, the refractive index difference between the medium inside the gap GP and the first translucent member 150 can be increased compared to when the inside of the gap GP is filled with another medium. The medium located inside the gap GP may contain, in addition to air, gas generated from the resin material, etc.

図４は、面状光源１０００を配線基板１１００の上面１１００ａに垂直に切断したときの断面のうち第１貫通孔２０ｈ内の空隙ＧＰとその周囲とを模式的に示す。図４は、第１貫通孔２０ｈ内の空隙ＧＰの形状の一例を示している。図４に示す例において、第１透光性部材１５０の表面の第１領域Ｒ１は、凹状を有している。言い換えれば、この例では、配線基板１１００の上面１１００ａに垂直な断面における第１領域Ｒ１の形状は、光源１３０に向かって凸の曲線状となっている。第１領域Ｒ１の断面形状が、光源１３０に向かって凸の曲線状を有することにより、光源１３０からの光を第１貫通孔２０ｈの上方から効率良く取り出すことができる。 Figure 4 shows a schematic diagram of the gap GP in the first through hole 20h and its surroundings in a cross section of the surface light source 1000 cut perpendicular to the upper surface 1100a of the wiring substrate 1100. Figure 4 shows an example of the shape of the gap GP in the first through hole 20h. In the example shown in Figure 4, the first region R1 on the surface of the first light-transmitting member 150 has a concave shape. In other words, in this example, the shape of the first region R1 in a cross section perpendicular to the upper surface 1100a of the wiring substrate 1100 is a curved shape that is convex toward the light source 130. By having the cross-sectional shape of the first region R1 have a curved shape that is convex toward the light source 130, light from the light source 130 can be efficiently extracted from above the first through hole 20h.

空隙ＧＰの、Ｘ方向に沿った長さ（空隙ＧＰの幅と言ってもよい）Ｗ１は、例えば１０μｍ以上１５０μｍ以下、より好ましくは７０μｍ以上７５μｍ以下の範囲である。空隙ＧＰの、図のＺ方向に沿った長さ（空隙ＧＰの高さと言ってもよい）Ｈ１は、例えば１０μｍ以上１５０μｍ以下、より好ましくは５０μｍ以上７０μｍ以下の範囲である。図４に示す例では、断面視における第１領域Ｒ１の形状は、概ね円弧状に描かれている。ただし、これはあくまでも第１領域Ｒ１の形状を模式的に表したに過ぎず、断面視における第１領域Ｒ１の形状は、図４に示す形状に限定されない。 The length W1 of the gap GP along the X direction (which may be referred to as the width of the gap GP) is, for example, in the range of 10 μm to 150 μm, and more preferably, 70 μm to 75 μm. The length H1 of the gap GP along the Z direction in the figure (which may be referred to as the height of the gap GP) is, for example, in the range of 10 μm to 150 μm, and more preferably, 50 μm to 70 μm. In the example shown in FIG. 4, the shape of the first region R1 in cross-section is depicted as being roughly arc-shaped. However, this is merely a schematic representation of the shape of the first region R1, and the shape of the first region R1 in cross-section is not limited to the shape shown in FIG. 4.

図５は、第１貫通孔２０ｈ内の空隙ＧＰの形状の他の一例を示す。図５に示す例では、第１透光性部材１５０の表面の第１領域Ｒ１は、図４に示す例とは逆に、配線基板１１００の上面１１００ａに垂直な断面において、光源１３０から離れる方向に膨らんだ凸状を有している。第１領域Ｒ１の断面形状が、光源１３０から離れる方向に膨らんだ凸状を有することにより、光源１３０からの光を横方向に伝播させつつ、第１貫通孔２０ｈの上方にも取り出すことができる。断面視における第１領域Ｒ１の形状は、図４および図５に例示する形状に限定されず、これらの図に示す形状を組み合わせた形状、あるいは、不定形状などであってもよい。 Figure 5 shows another example of the shape of the gap GP in the first through hole 20h. In the example shown in Figure 5, the first region R1 on the surface of the first translucent member 150 has a convex shape that bulges away from the light source 130 in a cross section perpendicular to the upper surface 1100a of the wiring board 1100, opposite to the example shown in Figure 4. By having the cross-sectional shape of the first region R1 have a convex shape that bulges away from the light source 130, the light from the light source 130 can be extracted above the first through hole 20h while propagating laterally. The shape of the first region R1 in cross section is not limited to the shapes exemplified in Figures 4 and 5, and may be a shape that combines the shapes shown in these figures, or may be an indefinite shape.

図４および図５に例示する構成において、配線基板１１００の上面１１００ａの法線方向（ここでは図のＺ方向に一致）における、第１貫通孔２０ｈ内の空隙ＧＰのサイズは、導光部材１２０の下面１２０ｂから光源１３０の上面１３０ａまでの最大距離（図５中に実線の両矢印Ｄ２で示す距離）よりも小さい。Ｚ方向において空隙ＧＰのサイズが導光部材１２０の下面１２０ｂから光源１３０の上面１３０ａまでの最大距離よりも小さいと、配線基板１１００の上面１１００ａに平行な面内（横方向といってもよい）に光を広げながらも、第１貫通孔２０ｈ内で第１貫通孔２０ｈの上方（例えば開口２０ａの近傍）に向かう光を増大させやすい。また、配線基板１１００の上面１１００ａの法線方向における、第１貫通孔２０ｈ内の空隙ＧＰのサイズが、導光部材１２０の下面１２０ｂから発光素子３２の上面３２ａまでの最大距離よりも小さいと有益である。 4 and 5, the size of the gap GP in the first through hole 20h in the normal direction of the upper surface 1100a of the wiring board 1100 (here, the Z direction in the figure) is smaller than the maximum distance from the lower surface 120b of the light guide member 120 to the upper surface 130a of the light source 130 (the distance indicated by the solid double arrow D2 in FIG. 5). If the size of the gap GP in the Z direction is smaller than the maximum distance from the lower surface 120b of the light guide member 120 to the upper surface 130a of the light source 130, it is easy to increase the light that is directed upward from the first through hole 20h (for example, near the opening 20a) in the first through hole 20h while spreading the light in a plane parallel to the upper surface 1100a of the wiring board 1100 (which may be called the horizontal direction). It is also beneficial if the size of the gap GP in the first through hole 20h in the normal direction of the upper surface 1100a of the wiring substrate 1100 is smaller than the maximum distance from the lower surface 120b of the light-guiding member 120 to the upper surface 32a of the light-emitting element 32.

ここで、上面１１００ａの法線方向における空隙ＧＰのサイズとは、導光部材１２０の下面１２０ｂの位置を基準として、第１透光性部材１５０の表面の第１領域Ｒ１のうち上面１１００ａの法線方向において導光部材１２０の下面１２０ｂから最も遠い点までの距離、すなわち、導光部材１２０の下面１２０ｂから第１領域Ｒ１までの最大距離（図５中に実線の両矢印Ｄ１で示す距離）を指す。本開示の典型的な実施形態において、第１透光性部材１５０の表面の第１領域Ｒ１は、光源１３０の上面１３０ａよりも低い位置にある。 Here, the size of the gap GP in the normal direction to the upper surface 1100a refers to the distance to the point in the first region R1 on the surface of the first light-transmissive member 150 that is farthest from the lower surface 120b of the light-guiding member 120 in the normal direction to the upper surface 1100a, based on the position of the lower surface 120b of the light-guiding member 120, i.e., the maximum distance from the lower surface 120b of the light-guiding member 120 to the first region R1 (the distance indicated by the solid double-headed arrow D1 in FIG. 5). In a typical embodiment of the present disclosure, the first region R1 on the surface of the first light-transmissive member 150 is located lower than the upper surface 130a of the light source 130.

図６および図７は、導光部材１２０の第１貫通孔２０ｈ内の空隙ＧＰの、上面視における配置の例を模式的に示す。なお、これらの図では、理解の容易のために、発光領域１００の発光面上に位置する光調整部材１４０を除いて、配線基板１１００の上面１１００ａの法線方向に見たときの発光領域１００の外観を模式的に示している。図６および図７では、第１貫通孔２０ｈ内において空隙の位置する部分を網掛けにより模式的に示している。 6 and 7 show schematic examples of the arrangement of the gap GP in the first through hole 20h of the light-guiding member 120 when viewed from above. For ease of understanding, these figures show a schematic appearance of the light-emitting region 100 when viewed in the normal direction of the upper surface 1100a of the wiring substrate 1100, excluding the light adjustment member 140 located on the light-emitting surface of the light-emitting region 100. In FIGS. 6 and 7, the portion in the first through hole 20h where the gap is located is shown typically by shading.

図６に示す例では、第１貫通孔２０ｈ内において、第１貫通孔２０ｈの円筒状の内側面２０ｃに沿って空隙ＧＰが切れ目なく配置されている。言い換えれば、この例では、第１透光性部材１５０の表面の第１領域Ｒ１の上面視形状は、第１貫通孔２０ｈの開口２０ａ、２０ｂの円形状にしたがった円環状を有している。 In the example shown in FIG. 6, the gap GP is arranged seamlessly within the first through hole 20h along the cylindrical inner surface 20c of the first through hole 20h. In other words, in this example, the top view shape of the first region R1 on the surface of the first translucent member 150 has a circular ring shape that conforms to the circular shape of the openings 20a, 20b of the first through hole 20h.

他方、図７に示す例では、複数の空隙が、第１貫通孔２０ｈの内側面２０ｃに沿って第１貫通孔２０ｈ内に配置されている。より具体的には、図７に示す例では、それぞれが第１貫通孔２０ｈの開口２０ａ、２０ｂの円形状にしたがった円弧状の第１～第４の空隙ＧＰ１～ＧＰ４が、第１貫通孔２０ｈ内に配置されている。 On the other hand, in the example shown in FIG. 7, multiple voids are arranged within the first through hole 20h along the inner surface 20c of the first through hole 20h. More specifically, in the example shown in FIG. 7, first to fourth voids GP1 to GP4, each of which is arc-shaped according to the circular shape of the openings 20a, 20b of the first through hole 20h, are arranged within the first through hole 20h.

このように、第１透光性部材１５０の表面の第１領域Ｒ１は、上面視において、それぞれが第１貫通孔２０ｈの内側面２０ｃに沿って延びる複数の部分を含んでいてもよい。第１領域Ｒ１は、図７に例示する構成のように４つの部分を含んでいてもよいし、より少ない数またはより多い数の複数の部分を含んでいてもよい。第１領域Ｒ１に含まれる複数の部分の形状が、これらの間で相似である必要はない。第１領域Ｒ１が複数の部分を含む場合、これら複数の部分は、光源１３０の光軸を中心として回転対称性を有する配置を有していてもよい。 In this way, the first region R1 on the surface of the first translucent member 150 may include multiple portions each extending along the inner surface 20c of the first through hole 20h in a top view. The first region R1 may include four portions as in the configuration illustrated in FIG. 7, or may include a smaller or larger number of portions. The shapes of the portions included in the first region R1 do not need to be similar to each other. When the first region R1 includes multiple portions, these portions may have an arrangement that has rotational symmetry around the optical axis of the light source 130.

次に、本開示の実施形態の面状光源１０００に適用可能な光源１３０の例を説明する。図２を参照しながら説明したように、光源１３０は、少なくとも発光素子３２をその一部に含む。 Next, an example of a light source 130 that can be applied to the surface light source 1000 of the embodiment of the present disclosure will be described. As described with reference to FIG. 2, the light source 130 includes at least a light-emitting element 32 as a part thereof.

図８および図９は、面状光源１０００に適用可能な光源１３０の例示的な構成を示す。図８は、光源１３０を上面１３０ａとは反対側から見たときの外観の一例を示す。図９は、図８に示す、上面１３０ａに垂直な平面Σで光源１３０を切断したときに現れる断面を模式的に示す。 Figures 8 and 9 show an exemplary configuration of the light source 130 applicable to the surface light source 1000. Figure 8 shows an example of the appearance of the light source 130 when viewed from the side opposite the top surface 130a. Figure 9 shows a schematic cross-section of the light source 130 when cut along a plane Σ perpendicular to the top surface 130a shown in Figure 8.

図９に例示する構成において、光源１３０は、発光素子３２と、第２透光性部材３４と、第２透光性部材３４上に位置する第１光反射層３６と、発光素子３２の下面３２ｂ側に位置する第２光反射層３８とを含む。 In the configuration illustrated in FIG. 9, the light source 130 includes a light-emitting element 32, a second translucent member 34, a first light-reflecting layer 36 located on the second translucent member 34, and a second light-reflecting layer 38 located on the lower surface 32b side of the light-emitting element 32.

発光素子３２は、配線基板１１００の上面１１００ａ側に位置する下面３２ｂに一対の電極３２ｅを有する。電極３２ｅは、複数の層を含む積層構造を有し得る。図９に示す例では、電極３２ｅは、銅などから形成された柱状の第１導電部材３と、第１導電部材３のうち第２光反射層３８から露出された部分を覆う金属層４とを含んでいる。金属層４は、例えばニッケルおよび金の積層膜である。 The light-emitting element 32 has a pair of electrodes 32e on the lower surface 32b located on the upper surface 1100a side of the wiring board 1100. The electrodes 32e may have a laminated structure including multiple layers. In the example shown in FIG. 9, the electrodes 32e include a columnar first conductive member 3 made of copper or the like, and a metal layer 4 that covers the portion of the first conductive member 3 exposed from the second light reflecting layer 38. The metal layer 4 is, for example, a laminated film of nickel and gold.

図８に示す例では、光源１３０の下面に相当する、第２光反射層３８の下面３８ｂに電極３２ｅの金属層４が現れている。言い換えれば、電極３２ｅの下面３２ｅｂは、第２光反射層３８から露出されている。 In the example shown in FIG. 8, the metal layer 4 of the electrode 32e appears on the lower surface 38b of the second light reflecting layer 38, which corresponds to the lower surface of the light source 130. In other words, the lower surface 32eb of the electrode 32e is exposed from the second light reflecting layer 38.

発光素子３２は、下面３２ｂとは反対側の上面３２ａを有する。第２透光性部材３４は、発光素子３２の上面３２ａと、側面３２ｃの少なくとも一部とを覆う。第１光反射層３６は、第２透光性部材３４の上面３４ａ上に配置されることにより、発光素子３２の上面３２ａの上方に位置する。第１光反射層３６の上面３６ａは、光源１３０の上面１３０ａを構成する。ここでは、光源１３０の上面１３０ａとしての上面３６ａは、上面視において矩形状を有する。上面３６ａの矩形状の一辺の長さは、例えば８５０μｍ程度であり得る。 The light-emitting element 32 has an upper surface 32a opposite to the lower surface 32b. The second translucent member 34 covers the upper surface 32a of the light-emitting element 32 and at least a part of the side surface 32c. The first light reflecting layer 36 is disposed on the upper surface 34a of the second translucent member 34, and is thereby positioned above the upper surface 32a of the light-emitting element 32. The upper surface 36a of the first light reflecting layer 36 constitutes the upper surface 130a of the light source 130. Here, the upper surface 36a as the upper surface 130a of the light source 130 has a rectangular shape when viewed from above. The length of one side of the rectangular shape of the upper surface 36a may be, for example, approximately 850 μm.

発光素子３２の上面３２ａの上方に第１光反射層３６を配置することにより、発光素子３２から上方に向けて出射された光の少なくとも一部を第１光反射層３６で反射させることができる。第１光反射層３６と第２透光性部材３４との界面での反射により、主に光源１３０の側方に光を取り出すことが可能になり、面状光源１０００の発光面のうち光源１３０の直上の領域における輝度（特に発光素子３２の光軸上の輝度）を抑えることができる。また、光源１３０のこのような構成は、空隙ＧＰの表面での反射を有効に利用する観点からも有利である。 By disposing the first light reflecting layer 36 above the upper surface 32a of the light emitting element 32, at least a portion of the light emitted upward from the light emitting element 32 can be reflected by the first light reflecting layer 36. Reflection at the interface between the first light reflecting layer 36 and the second translucent member 34 makes it possible to extract light mainly to the side of the light source 130, and the brightness in the area directly above the light source 130 on the light emitting surface of the planar light source 1000 (particularly the brightness on the optical axis of the light emitting element 32) can be suppressed. In addition, such a configuration of the light source 130 is advantageous from the viewpoint of effectively utilizing the reflection on the surface of the gap GP.

光源１３０は、導光部材１２０の第１貫通孔２０ｈ内に配置され、その周囲には、第１透光性部材１５０が配置される。なお、図２に示す例では、発光領域１００は、第１透光性部材１５０上に位置する光調整部材１４０をさらに有している。この例では、光調整部材１４０は、第１透光性部材１５０の上面１５０ａの全体を覆っている。 The light source 130 is disposed in the first through hole 20h of the light-guiding member 120, and the first translucent member 150 is disposed around it. In the example shown in FIG. 2, the light-emitting region 100 further includes a light adjustment member 140 located on the first translucent member 150. In this example, the light adjustment member 140 covers the entire upper surface 150a of the first translucent member 150.

光調整部材１４０を光源１３０の上方に配置することにより、発光素子３２から上方に向けて出射された光の少なくとも一部を光調整部材１４０で反射させることができる。したがって、発光領域１００の発光面のうち発光素子３２から離れた位置にある領域と比較して、発光素子３２の直上に位置する領域の輝度が極端に高くなることを抑制し得る。すなわち、上面視において、第１貫通孔２０ｈとその周囲との間に輝度の急峻な変化が生じることをより効果的に低減することが可能になる。 By disposing the light adjustment member 140 above the light source 130, at least a portion of the light emitted upward from the light emitting element 32 can be reflected by the light adjustment member 140. Therefore, it is possible to prevent the brightness of the area located directly above the light emitting element 32 from becoming extremely high compared to an area of the light emitting surface of the light emitting region 100 that is located away from the light emitting element 32. In other words, it is possible to more effectively reduce the occurrence of abrupt changes in brightness between the first through hole 20h and its surroundings when viewed from above.

図２に例示するように、光調整部材１４０は、第１透光性部材１５０の上面１５０ａだけでなく導光部材１２０の上面１２０ａのうち第１透光性部材１５０の上面１５０ａの周囲に位置する領域にまで位置していてもよい。なお、光調整部材１４０が第１透光性部材１５０の上面１５０ａの全体を覆っていることは、必須ではない。光調整部材１４０は、第１透光性部材１５０の上面１５０ａの一部が露出された形状を有していてもよい。 As illustrated in FIG. 2, the light adjustment member 140 may be located not only on the upper surface 150a of the first translucent member 150 but also on the upper surface 120a of the light guide member 120 in a region surrounding the upper surface 150a of the first translucent member 150. It is not essential that the light adjustment member 140 covers the entire upper surface 150a of the first translucent member 150. The light adjustment member 140 may have a shape in which a portion of the upper surface 150a of the first translucent member 150 is exposed.

次に、導光部材１２０を支持する配線基板１１００の概略を説明する。図２に例示する構成において、配線基板１１００は、上面１１０ａおよび下面１１０ｂを有する支持体１１０と、支持体１１０の下面１１０ｂ上に配置された配線層１１６と、支持体１１０を貫通する導電部１６０と、支持体１１０の下面１１０ｂ側に位置する絶縁層１７０とを含む。 Next, an outline of the wiring board 1100 that supports the light-guiding member 120 will be described. In the configuration illustrated in FIG. 2, the wiring board 1100 includes a support 110 having an upper surface 110a and a lower surface 110b, a wiring layer 116 disposed on the lower surface 110b of the support 110, a conductive portion 160 that penetrates the support 110, and an insulating layer 170 located on the lower surface 110b side of the support 110.

配線基板１１００の支持体１１０の典型例は、フレキシブルプリント基板である。ここでは、支持体１１０は、それぞれが支持体１１０の上面１１０ａの法線方向に貫通する複数の貫通孔１０ｈ（以下、「第２貫通孔１０ｈ」と呼ぶ）を有している。１つの発光領域１００に注目すると、支持体１１０は、発光素子３２の一対の電極３２ｅに対応して一対の第２貫通孔１０ｈを有する。 A typical example of the support 110 of the wiring board 1100 is a flexible printed circuit board. Here, the support 110 has a plurality of through holes 10h (hereinafter referred to as "second through holes 10h") that each penetrate in the normal direction of the upper surface 110a of the support 110. Focusing on one light-emitting region 100, the support 110 has a pair of second through holes 10h corresponding to a pair of electrodes 32e of the light-emitting element 32.

図２に模式的に示すように、各第２貫通孔１０ｈ内には導電部１６０が配置される。各導電部１６０の一方の端部は、発光素子３２の電極３２ｅのうち対応する１つの下面３２ｅｂに接することにより、その電極との間に電気的接続を有する。第２貫通孔１０ｈ内の導電部１６０のそれぞれは、支持体１１０の下面１１０ｂ側において配線層１１６まで延び、配線層１１６に電気的に接続される。 As shown in FIG. 2, a conductive portion 160 is disposed in each second through hole 10h. One end of each conductive portion 160 is in contact with the lower surface 32eb of a corresponding one of the electrodes 32e of the light-emitting element 32, thereby establishing an electrical connection with that electrode. Each of the conductive portions 160 in the second through holes 10h extends to the wiring layer 116 on the lower surface 110b side of the support 110, and is electrically connected to the wiring layer 116.

配線層１１６は、配線基板１１００の延伸部１１０ｔの端子部（図１参照）まで延びる。このような導電構造を有することにより、配線基板１１００は、支持体１１０の下面１１０ｂ側の配線層１１６と、第２貫通孔１０ｈ内の導電部１６０とを介して、外部の電源から発光素子３２に所定の電流を供給可能である。この例では、導電部１６０の一部および配線層１１６を覆う絶縁層１７０が支持体１１０の下面１１０ｂ側にさらに配置されている。 The wiring layer 116 extends to the terminal portion (see FIG. 1) of the extension portion 110t of the wiring substrate 1100. By having such a conductive structure, the wiring substrate 1100 can supply a predetermined current from an external power source to the light emitting element 32 via the wiring layer 116 on the lower surface 110b side of the support 110 and the conductive portion 160 in the second through hole 10h. In this example, an insulating layer 170 that covers a part of the conductive portion 160 and the wiring layer 116 is further disposed on the lower surface 110b side of the support 110.

次に、支持体１１０の上面１１０ａ側に注目すると、図２に示す例では、支持体１１０の上面１１０ａ上に第１接着層１１２が配置されている。また、この例では、第１接着層１１２上に光反射性シート１１４が配置されている。すなわち、この例では、配線基板１１００は、支持体１１０に加えて第１接着層１１２および光反射性シート１１４を含んでいる。ここでは、光反射性シート１１４の上面が配線基板１１００の上面１１００ａを構成している。 Next, looking at the upper surface 110a of the support 110, in the example shown in FIG. 2, a first adhesive layer 112 is disposed on the upper surface 110a of the support 110. Also, in this example, a light-reflecting sheet 114 is disposed on the first adhesive layer 112. That is, in this example, the wiring board 1100 includes the first adhesive layer 112 and the light-reflecting sheet 114 in addition to the support 110. Here, the upper surface of the light-reflecting sheet 114 constitutes the upper surface 1100a of the wiring board 1100.

さらにこの例では、導光部材１２０と光反射性シート１１４との間に第２接着層１８０が配置されている。導光部材１２０は、第２接着層１８０によって配線基板１１００に固定される。図２に示すように、上述の導電部１６０は、第１接着層１１２、光反射性シート１１４および第２接着層１８０を貫通して発光素子３２の電極３２ｅの下面３２ｅｂに達する。 Furthermore, in this example, a second adhesive layer 180 is disposed between the light guide member 120 and the light reflecting sheet 114. The light guide member 120 is fixed to the wiring board 1100 by the second adhesive layer 180. As shown in FIG. 2, the conductive portion 160 described above penetrates the first adhesive layer 112, the light reflecting sheet 114, and the second adhesive layer 180 to reach the lower surface 32eb of the electrode 32e of the light emitting element 32.

以下、面状光源１０００の各構成要素をより詳細に説明する。 The components of the surface light source 1000 are described in more detail below.

［発光素子３２］
上述したように、発光素子３２の典型例は、ＬＥＤである。発光素子３２は、サファイアまたは窒化ガリウムなどの透光性の支持基板と、支持基板上の半導体積層体と、半導体積層体に電気的に接続された一対の電極３２ｅとを有し得る。発光素子３２が支持基板を有する場合、支持基板の主面のうち、半導体積層体が配置された主面とは反対側の主面が、発光素子３２の上面３２ａを構成する。 [Light-emitting element 32]
As described above, a typical example of the light-emitting element 32 is an LED. The light-emitting element 32 may have a light-transmitting support substrate such as sapphire or gallium nitride, a semiconductor laminate on the support substrate, and a pair of electrodes 32e electrically connected to the semiconductor laminate. When the light-emitting element 32 has a support substrate, the main surface of the support substrate opposite to the main surface on which the semiconductor laminate is disposed constitutes the upper surface 32a of the light-emitting element 32.

半導体積層体は、ｎ型半導体層およびｐ型半導体層と、これらに挟まれた発光層とを含む。発光層は、ダブルヘテロ接合または単一量子井戸(ＳＱＷ)などの構造を有していてもよいし、多重量子井戸(ＭＱＷ)のようにひとかたまりの活性層群をもつ構造を有していてもよい。半導体積層体は、可視光または紫外光を発光可能に構成されている。このような発光層を含む半導体積層体は、例えばＩｎxＡｌyＧａ1-x-yＮ（０≦ｘ、０≦ｙ、ｘ＋ｙ≦１）を含み得る。 The semiconductor laminate includes an n-type semiconductor layer, a p-type semiconductor layer, and a light-emitting layer sandwiched between them. The light-emitting layer may have a structure such as a double heterojunction or a single quantum well (SQW), or may have a structure having a group of active layers such as a multiple quantum well (MQW). The semiconductor laminate is configured to be capable of emitting visible light or ultraviolet light. Such a semiconductor laminate including a light-emitting layer may include, for example, In x Al y Ga 1-xy N (0≦x, 0≦y, x+y≦1).

半導体積層体は、ｎ型半導体層とｐ型半導体層との間に１つ以上の発光層を含む構造を有していてもよいし、ｎ型半導体層と発光層とｐ型半導体層とを順に含む構造が複数回繰り返された構造を有していてもよい。半導体積層体が複数の発光層を含む場合、半導体積層体は、発光ピーク波長が異なる発光層を含んでいてもよいし、発光ピーク波長が同じ発光層を含んでいてもよい。なお、発光ピーク波長が同じとは、数ｎｍ程度のばらつきがある場合も含む。各発光層は、発光ピーク波長が異なる複数の活性層を含んでいてもよいし、発光ピーク波長が同じ複数の活性層を含んでいてもよい。 The semiconductor laminate may have a structure including one or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may have a structure in which a structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in that order is repeated multiple times. When the semiconductor laminate includes multiple light-emitting layers, the semiconductor laminate may include light-emitting layers having different emission peak wavelengths, or may include light-emitting layers having the same emission peak wavelength. Note that the same emission peak wavelength includes cases where there is a variation of about several nm. Each light-emitting layer may include multiple active layers having different emission peak wavelengths, or may include multiple active layers having the same emission peak wavelength.

［第２透光性部材３４］
第２透光性部材３４は、発光素子３２の上面３２ａ上と、側面３２ｃの少なくとも一部上とに位置する。発光素子３２が複数の側面３２ｃを有する場合、第２透光性部材３４は、各側面３２ｃ（例えば４つの側面３２ｃのそれぞれ）の一部または全部を覆う。 [Second light-transmissive member 34]
The second light-transmissive member 34 is located on the upper surface 32a and on at least a part of the side surfaces 32c of the light-emitting element 32. When the light-emitting element 32 has a plurality of side surfaces 32c, the second light-transmissive member 34 covers a part or all of each of the side surfaces 32c (e.g., each of the four side surfaces 32c).

第２透光性部材３４の材料には、透明な樹脂を母材として含む樹脂材料を適用できる。第２透光性部材３４の母材として、エポキシ樹脂、シリコーン樹脂、シリコーン変性樹脂、フェノール樹脂、ポリカーボネート樹脂、アクリル樹脂、ポリメチルペンテン樹脂もしくはポリノルボルネン樹脂、または、これらの２種以上を含む材料を用いてもよい。 The material of the second translucent member 34 can be a resin material containing a transparent resin as a base material. The base material of the second translucent member 34 can be an epoxy resin, a silicone resin, a silicone modified resin, a phenol resin, a polycarbonate resin, an acrylic resin, a polymethylpentene resin, a polynorbornene resin, or a material containing two or more of these.

第２透光性部材３４は、発光素子３２の発光ピーク波長を有する光に対して、例えば６０％以上の透過率を有する。光の取出し効率を高める観点から、発光素子３２の発光ピーク波長における第２透光性部材３４の透過率が７０％以上であると有益であり、８０％以上であるとより有益である。 The second translucent member 34 has a transmittance of, for example, 60% or more for light having the emission peak wavelength of the light-emitting element 32. From the viewpoint of increasing the light extraction efficiency, it is beneficial for the transmittance of the second translucent member 34 at the emission peak wavelength of the light-emitting element 32 to be 70% or more, and it is even more beneficial for the transmittance to be 80% or more.

第２透光性部材３４は、蛍光体などの波長変換材料を含有し得る。例えば、発光素子３２に青色ＬＥＤを用い、発光素子３２からの青色光の一部を波長変換して黄色光を発する波長変換材料を第２透光性部材３４に含有させ得る。この場合、第２透光性部材３４を通過した青色光と、第２透光性部材３４に含まれる波長変換材料から発せられた黄色光との混色によって、白色光が得られる。 The second translucent member 34 may contain a wavelength conversion material such as a phosphor. For example, a blue LED may be used as the light-emitting element 32, and the second translucent member 34 may contain a wavelength conversion material that converts the wavelength of part of the blue light from the light-emitting element 32 to emit yellow light. In this case, white light is obtained by mixing the blue light that has passed through the second translucent member 34 with the yellow light emitted from the wavelength conversion material contained in the second translucent member 34.

第２透光性部材３４に含有させる波長変換材料には、公知の蛍光体を適用できる。蛍光体の例は、ＫＳＦ系蛍光体（例えばＫ２ＳｉＦ６：Ｍｎ）、ＫＳＡＦ系蛍光体（例えばＫ２（Ｓｉ，Ａｌ）Ｆ６：Ｍｎ）などのフッ化物系蛍光体およびＣＡＳＮなどの窒化物系蛍光体（例えばＣａＡｌＳｉＮ３：Ｅｕ、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３：Ｅｕ）、ＹＡＧ系蛍光体（例えばＹ３（Ａｌ，Ｇａ）５Ｏ１２：Ｃｅ）、βサイアロン蛍光体（例えば（Ｓｉ，Ａｌ）３（Ｏ，Ｎ）４：Ｅｕ）などである。ＫＳＦ系蛍光体、ＫＳＡＦ系蛍光体およびＣＡＳＮは、青色光を赤色光に変換する波長変換材料の例であり、ＹＡＧ系蛍光体は、青色光を黄色光に変換する波長変換材料の例である。βサイアロン蛍光体は、青色光を緑色光に変換する波長変換材料の例である。蛍光体は、ペロブスカイト構造を有する蛍光体（例えばＣｓＰｂ（Ｆ，Ｃｌ，Ｂｒ，Ｉ）３）、または、量子ドット蛍光体（例えばＣｄＳｅ、ＩｎＰ、ＡｇＩｎＳ２またはＡｇＩｎＳｅ２）であってもよい。第２透光性部材３４は、二酸化チタン、酸化ケイ素の粒子などの光拡散材をさらに含有していてもよい。 Known phosphors can be applied to the wavelength conversion material contained in the second light-transmissive member 34. Examples of phosphors include fluoride phosphors such as KSF phosphors (e.g., K 2 SiF 6 :Mn) and KSAF phosphors (e.g., K 2 (Si, Al) F 6 :Mn), and nitride phosphors such as CASN (e.g., CaAlSiN 3 :Eu, (Sr, Ca)AlSiN 3 :Eu), YAG phosphors (e.g., Y 3 (Al, Ga) 5 O 12 :Ce), and β-sialon phosphors (e.g., (Si, Al) 3 (O, N) 4 :Eu). KSF phosphors, KSAF phosphors, and CASN are examples of wavelength conversion materials that convert blue light to red light, and YAG phosphors are examples of wavelength conversion materials that convert blue light to yellow light. The β-sialon phosphor is an example of a wavelength conversion material that converts blue light to green light. The phosphor may be a phosphor having a perovskite structure (e.g., CsPb(F,Cl,Br,I) 3 ) or a quantum dot phosphor (e.g., CdSe, InP, AgInS2 , or AgInSe2 ). The second light-transmitting member 34 may further contain a light diffusing material such as titanium dioxide or silicon oxide particles.

［第１光反射層３６］
第１光反射層３６は、第２透光性部材３４の上面３４ａ上に配置され、典型的には、上面３４ａの全体を覆う。第１光反射層３６の材料には、例えば、白色の樹脂材料を用いることができる。白色の樹脂材料は、典型的には、母材と、光反射性のフィラーとを含む。 [First light reflecting layer 36]
The first light reflecting layer 36 is disposed on the upper surface 34a of the second light-transmitting member 34, and typically covers the entire upper surface 34a. For example, a white resin material can be used as the material of the first light reflecting layer 36. The white resin material typically includes a base material and a light-reflective filler.

本明細書において、「光反射性」とは、発光素子３２の発光ピーク波長における反射率が６０％以上であることを指す。第１光反射層３６の反射率は、面状光源１０００の用途によって適宜に調整され得る。第１光反射層３６は、発光素子３２から出射された光を適度に反射させ、発光素子３２直上の輝度を適度に低下できればよい。第１光反射層３６が発光素子３２からの光を完全に遮蔽することは、必須ではない。 In this specification, "light reflectivity" refers to a reflectance of 60% or more at the emission peak wavelength of the light-emitting element 32. The reflectance of the first light reflecting layer 36 can be adjusted appropriately depending on the application of the surface light source 1000. It is sufficient for the first light reflecting layer 36 to appropriately reflect the light emitted from the light-emitting element 32 and appropriately reduce the luminance directly above the light-emitting element 32. It is not essential that the first light reflecting layer 36 completely blocks the light from the light-emitting element 32.

第１光反射層３６の母材の例は、シリコーン樹脂、フェノール樹脂、エポキシ樹脂、ＢＴレジン、ポリフタルアミド（ＰＰＡ）などである。光反射性のフィラーとしては、金属の粒子、または、母材よりも高い屈折率を有する無機材料もしくは有機材料の粒子を用いることができる。光反射性のフィラーの例は、銀もしくはアルミニウムなどの金属の粒子、二酸化チタン、酸化ケイ素、二酸化ジルコニウム、チタン酸カリウム、酸化亜鉛、酸化アルミニウム、酸化マグネシウム、窒化アルミニウム、窒化ホウ素、ムライト、酸化ニオブ、フッ化カルシウム、フッ化マグネシウムもしくは硫酸バリウムの粒子、または、酸化イットリウムおよび酸化ガドリニウムなどの各種希土類酸化物の粒子などである。 Examples of the base material of the first light reflecting layer 36 include silicone resin, phenolic resin, epoxy resin, BT resin, polyphthalamide (PPA), etc. As the light reflecting filler, metal particles, or particles of inorganic or organic materials having a higher refractive index than the base material can be used. Examples of the light reflecting filler include particles of metals such as silver or aluminum, titanium dioxide, silicon oxide, zirconium dioxide, potassium titanate, zinc oxide, aluminum oxide, magnesium oxide, aluminum nitride, boron nitride, mullite, niobium oxide, calcium fluoride, magnesium fluoride, or barium sulfate, or particles of various rare earth oxides such as yttrium oxide and gadolinium oxide.

第１光反射層３６は、白色の樹脂層に限定されない。第１光反射層３６は、Ａｇ膜もしくはＡｌ膜などの金属膜または誘電体多層膜などの反射膜であってもよい。第１光反射層３６は、白色の樹脂層と反射膜との複合体であってもよい。例えば、第１光反射層３６は、白色の樹脂層と金属膜との複合体であってもよい。 The first light reflecting layer 36 is not limited to a white resin layer. The first light reflecting layer 36 may be a metal film such as an Ag film or an Al film, or a reflective film such as a dielectric multilayer film. The first light reflecting layer 36 may be a composite of a white resin layer and a reflective film. For example, the first light reflecting layer 36 may be a composite of a white resin layer and a metal film.

［第２光反射層３８］
第２光反射層３８は、発光素子３２の下面３２ｂ側に位置し、発光素子３２の下面３２ｂのうち電極３２ｅの配置された領域以外の領域と、第２透光性部材３４の下面とを覆う。第２光反射層３８は、例えば、第１光反射層３６と同様に、母材と、光反射性のフィラーとを含有する。光源１３０が第２光反射層３８を有することにより、発光素子３２の下面３２ｂ側からの光の漏れを低減でき、光の取出し効率の低下を回避し得る。 [Second light reflecting layer 38]
The second light reflecting layer 38 is located on the lower surface 32b side of the light emitting element 32, and covers the area of the lower surface 32b of the light emitting element 32 other than the area where the electrode 32e is arranged, and the lower surface of the second light-transmissive member 34. The second light reflecting layer 38 contains a base material and a light-reflective filler, similar to the first light reflecting layer 36, for example. By having the second light reflecting layer 38 in the light source 130, it is possible to reduce leakage of light from the lower surface 32b side of the light emitting element 32, and to avoid a decrease in light extraction efficiency.

なお、面状光源１０００に適用される光源が、第２透光性部材３４、第１光反射層３６および第２光反射層３８のすべてを有していることは、本開示の実施形態において必須ではない。例えば、発光素子３２の下面３２ｂ側に位置する第２光反射層３８が省略されることがあり得る。光源１３０から第２透光性部材３４が省略されてもよい。この場合、第１光反射層３６は、発光素子３２の上面３２ａ上に直接に接する。さらにこの場合において、第２光反射層３８が省略されてもよい。すなわち、発光素子３２と、発光素子３２の上面３２ａ上の第１光反射層３６とから構成される光源を面状光源１０００に適用してもよい。あるいは、第２透光性部材３４、第１光反射層３６および第２光反射層３８のいずれをも有しない発光素子３２単体を光源１３０として利用することも可能である。 Note that, in the embodiment of the present disclosure, it is not essential that the light source applied to the surface light source 1000 has all of the second translucent member 34, the first light reflecting layer 36, and the second light reflecting layer 38. For example, the second light reflecting layer 38 located on the lower surface 32b side of the light emitting element 32 may be omitted. The second translucent member 34 may be omitted from the light source 130. In this case, the first light reflecting layer 36 is in direct contact with the upper surface 32a of the light emitting element 32. Furthermore, in this case, the second light reflecting layer 38 may be omitted. That is, a light source composed of the light emitting element 32 and the first light reflecting layer 36 on the upper surface 32a of the light emitting element 32 may be applied to the surface light source 1000. Alternatively, it is also possible to use a single light emitting element 32 that does not have any of the second translucent member 34, the first light reflecting layer 36, and the second light reflecting layer 38 as the light source 130.

［導光部材１２０］
導光部材１２０は、配線基板１１００の上面１１００ａ側に位置する、透光性を有する概ね板状の部材である。導光部材１２０は、例えば１５０μｍ以上８００μｍ以下の範囲の厚さを有する。 [Light guiding member 120]
The light guide member 120 is a generally plate-like member having light transmissivity, located on the upper surface 1100a side of the wiring substrate 1100. The light guide member 120 has a thickness in the range of, for example, 150 μm or more and 800 μm or less.

導光部材１２０は、アクリル、ポリカーボネート、環状ポリオレフィン、ポリエチレンテレフタラート、ポリエステルなどの熱可塑性樹脂、または、エポキシ、シリコーンなどの熱硬化性樹脂で構成される。導光部材１２０の材料として、ガラスを用いてもよい。 The light-guiding member 120 is made of a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, or polyester, or a thermosetting resin such as epoxy or silicone. Glass may also be used as the material for the light-guiding member 120.

本明細書における「透光性」の用語は、入射した光に対して拡散性を示すことをも包含するように解釈され、「透明」であることに限定されない。母材とは異なる屈折率を有する光拡散材が分散させられることにより、導光部材１２０が光拡散機能を有していてもよい。 In this specification, the term "translucency" is interpreted to include the ability to diffuse incident light, and is not limited to being "transparent." The light guide member 120 may have a light diffusion function by dispersing a light diffusion material having a refractive index different from that of the base material.

導光部材１２０は、光源１３０からの光をその内部に伝播させて上面１２０ａから出射させる機能を有する。導光部材１２０の上面１２０ａは、典型的には、矩形状を有する。上面１２０ａの矩形状の一辺の長さは、８．６ｍｍ程度であり得る。図１に示す例においては、複数の導光部材１２０の上面１２０ａの集合が面状光源１０００の発光面を構成している。 The light guide member 120 has a function of propagating the light from the light source 130 inside and emitting it from the upper surface 120a. The upper surface 120a of the light guide member 120 typically has a rectangular shape. The length of one side of the rectangular shape of the upper surface 120a may be approximately 8.6 mm. In the example shown in FIG. 1, a collection of the upper surfaces 120a of the multiple light guide members 120 constitutes the light emitting surface of the surface light source 1000.

上述したように、導光部材１２０は、複数の溝部２０ｇを有し得る。溝部２０ｇは、例えば、面状光源１０００において、互いに隣接する２つの単位構造１００の境界に位置し、上面視において各単位構造１００の導光部材１２０の第１貫通孔２０ｈを取り囲む配置を有する。導光部材１２０が溝部２０ｇを有することにより、例えばローカルディミング駆動下において、互いに隣接する２つの単位構造１００の間におけるコントラスト比（光源が点灯させられた単位構造と、その単位構造に隣接し、かつ光源が消灯させられた単位構造との間における輝度変化の急峻さ）を有利に向上させ得る。 As described above, the light-guiding member 120 may have a plurality of grooves 20g. The grooves 20g are located, for example, at the boundary between two adjacent unit structures 100 in the planar light source 1000, and are arranged to surround the first through holes 20h of the light-guiding member 120 of each unit structure 100 in a top view. By having the grooves 20g in the light-guiding member 120, for example, under local dimming drive, the contrast ratio between two adjacent unit structures 100 (the steepness of the luminance change between a unit structure with a light source turned on and a unit structure adjacent to that unit structure with a light source turned off) can be advantageously improved.

図２に示す例では、各溝部２０ｇは、導光部材１２０の上面１２０ａに位置する開口を含み、その底は、第２接着層１８０の上面にまで達している。溝部２０ｇは、第２接着層１８０および光反射性シート１１４をも貫通して第１接着層１１２まで達していてもよい。支持体１１０に配線層１１６を形成したことに起因する、配線基板１１００の応力の緩和の観点からは、第１接着層１１２に達する深さで溝部２０ｇを形成すると有利である。 In the example shown in FIG. 2, each groove 20g includes an opening located on the upper surface 120a of the light-guiding member 120, and its bottom reaches the upper surface of the second adhesive layer 180. The groove 20g may also penetrate the second adhesive layer 180 and the light-reflective sheet 114 to reach the first adhesive layer 112. From the viewpoint of alleviating the stress of the wiring board 1100 caused by forming the wiring layer 116 on the support 110, it is advantageous to form the groove 20g to a depth that reaches the first adhesive layer 112.

溝部２０ｇの形状を規定する内側面は、断面視において、導光部材１２０の上面１２０ａに垂直であってもよいし、図２に例示するように上面１２０ａに対して傾いていてもよい。溝部２０ｇの内側面は、断面視において段差を有していてもよい。 The inner side surface that defines the shape of the groove portion 20g may be perpendicular to the upper surface 120a of the light guide member 120 in a cross-sectional view, or may be inclined with respect to the upper surface 120a as illustrated in FIG. 2. The inner side surface of the groove portion 20g may have a step in a cross-sectional view.

溝部２０ｇの内部に光反射性の区画部材が配置されることもある。区画部材は、例えば、母材としての樹脂と、光反射性のフィラーとを含有する樹脂材料で構成される。区画部材の材料としては、第１光反射層３６または第２光反射層３８と同様の材料を用い得る。区画部材は、白色の樹脂層であり得る。 A light-reflective partition member may be disposed inside the groove portion 20g. The partition member is made of, for example, a resin material containing a resin as a base material and a light-reflective filler. The material of the partition member may be the same as that of the first light-reflective layer 36 or the second light-reflective layer 38. The partition member may be a white resin layer.

区画部材の材料は、樹脂を母材とする材料に限定されない。区画部材は、金属膜（Ａｇ膜、Ａｌ膜など）、誘電体多層膜などの反射膜であってもよい。なお、区画部材は、その一部が導光部材１２０の上面１２０ａを覆う形状を有していてもよい。 The material of the partition member is not limited to materials having a resin as a base material. The partition member may be a metal film (Ag film, Al film, etc.) or a reflective film such as a dielectric multilayer film. The partition member may have a shape such that a part of it covers the upper surface 120a of the light-guiding member 120.

各溝部２０ｇの上面視における幅は、例えば２００μｍ以上１０００μｍ以下である。なお、導光部材１２００の外縁に位置する溝部２０ｇは、省略されることがあり得る。 The width of each groove 20g in top view is, for example, 200 μm or more and 1000 μm or less. Note that the groove 20g located on the outer edge of the light-guiding member 1200 may be omitted.

［第１透光性部材１５０］
第１透光性部材１５０は、導光部材１２０の第１貫通孔２０ｈ内に位置し、光源１３０を覆う。第１透光性部材１５０の材料には、樹脂を母材として含む材料を適用できる。第１透光性部材１５０の母材の典型例は、エポキシ樹脂、シリコーン樹脂などの熱硬化性樹脂である。光源からの光を導光部材１２０の内部に効率的に導入する観点からは、第１透光性部材１５０が導光部材１２０の材料と同等であるかあるいは導光部材１２０の材料よりも高い屈折率を有していると有利である。第１透光性部材１５０は、単層であってもよいし、後述するように、複数の層を含む積層構造を有していてもよい。 [First light-transmissive member 150]
The first light-transmissive member 150 is located in the first through-hole 20h of the light-guiding member 120 and covers the light source 130. The material of the first light-transmissive member 150 can be a material containing a resin as a base material. Typical examples of the base material of the first light-transmissive member 150 are thermosetting resins such as epoxy resin and silicone resin. From the viewpoint of efficiently introducing light from the light source into the inside of the light-guiding member 120, it is advantageous that the first light-transmissive member 150 has a refractive index equal to or higher than that of the material of the light-guiding member 120. The first light-transmissive member 150 may be a single layer, or may have a laminated structure including multiple layers as described later.

第１透光性部材１５０には波長変換材料を含有させることができる。また、波長変換材料に代えて、あるいは、波長変換材料に加えて、第１透光性部材１５０に光拡散材を含有させることもできる。なお、面状光源１０００の製造工程において、導電部１６０の形成後の動作確認の際に、光源１３０からの光の色度が所期の色度からずれていることが判明することがある。そのような場合であっても、動作確認の結果に基づき、単位構造１００ごとに第１透光性部材１５０中の波長変換材料の含有の有無および量を変えることにより、光源１３０を点灯させたときの第１透光性部材１５０の上面１５０ａの色度を、面状光源１０００中の複数の単位構造１００の間で揃えることができる。第１透光性部材１５０に波長変換材料を含有させることは、事後的な色補正を可能にする。すなわち、所期の色度からのずれが発見された光源自体を取り換えることなく、面状光源１０００の歩留まりを向上させ得る。 The first translucent member 150 can contain a wavelength conversion material. Alternatively, instead of or in addition to the wavelength conversion material, the first translucent member 150 can contain a light diffusing material. In the manufacturing process of the planar light source 1000, when the operation of the conductive portion 160 is confirmed after the formation of the conductive portion 160, it may be found that the chromaticity of the light from the light source 130 deviates from the desired chromaticity. Even in such a case, the chromaticity of the upper surface 150a of the first translucent member 150 when the light source 130 is turned on can be made uniform among the multiple unit structures 100 in the planar light source 1000 by changing the presence or absence and amount of the wavelength conversion material contained in the first translucent member 150 for each unit structure 100 based on the result of the operation confirmation. The inclusion of the wavelength conversion material in the first translucent member 150 enables subsequent color correction. In other words, the yield of the planar light source 1000 can be improved without replacing the light source itself in which a deviation from the desired chromaticity is found.

第１透光性部材１５０の上面１５０ａは、その少なくとも一部が導光部材１２０の上面１２０ａよりも低い位置にあってもよい。言い換えれば、第１透光性部材１５０の上面１５０ａは、導光部材１２０の上面１２０ａよりも配線基板１１００の上面１１００ａに近い部分を有していてもよい。第１透光性部材１５０の上面１５０ａが、導光部材１２０の上面１２０ａよりも低い位置にある部分を含む場合、第１透光性部材１５０の上面１２０ａ上に第３透光性部材を配置してもよい。すなわち、第１貫通孔２０ｈ内に位置する透光性部材は、積層構造を有していてもよい。第１貫通孔２０ｈ内に第３透光性部材を配置する場合、第３透光性部材の上面を概ね平坦とし、かつ、導光部材１２０の上面１２０ａに整合させてもよい。 At least a part of the upper surface 150a of the first light-transmissive member 150 may be located lower than the upper surface 120a of the light-guiding member 120. In other words, the upper surface 150a of the first light-transmissive member 150 may have a portion closer to the upper surface 1100a of the wiring board 1100 than the upper surface 120a of the light-guiding member 120. When the upper surface 150a of the first light-transmissive member 150 includes a portion located lower than the upper surface 120a of the light-guiding member 120, a third light-transmissive member may be disposed on the upper surface 120a of the first light-transmissive member 150. That is, the light-transmissive member located in the first through hole 20h may have a laminated structure. When the third light-transmissive member is disposed in the first through hole 20h, the upper surface of the third light-transmissive member may be made approximately flat and may be aligned with the upper surface 120a of the light-guiding member 120.

第３透光性部材の材料は、第１透光性部材１５０と同じであってもよいし、異なっていてもよい。例えば、第３透光性部材が、第１透光性部材１５０と同種の透光性樹脂を母材として含む場合、第３透光性部材および第１透光性部材１５０の屈折率をほぼ等しくし得る。第３透光性部材および第１透光性部材１５０の屈折率差の縮小により、第１透光性部材１５０と第３透光性部材との界面における反射が低減され、第１透光性部材１５０から第３透光性部材に光が効率的に導入されるようになる。第３透光性部材の屈折率を第１透光性部材１５０の屈折率よりも小さくしてもよい。この場合、第１透光性部材１５０中を伝播する光を第１透光性部材１５０と第３透光性部材との界面で反射させることができ、第３透光性部材の上面のうち光源１３０の直上の領域の輝度が高くなりすぎることを抑制し得る。 The material of the third translucent member may be the same as or different from that of the first translucent member 150. For example, when the third translucent member contains the same type of translucent resin as the first translucent member 150 as a base material, the refractive indexes of the third translucent member and the first translucent member 150 can be made approximately equal. By reducing the refractive index difference between the third translucent member and the first translucent member 150, reflection at the interface between the first translucent member 150 and the third translucent member is reduced, and light is efficiently introduced from the first translucent member 150 to the third translucent member. The refractive index of the third translucent member may be smaller than that of the first translucent member 150. In this case, the light propagating through the first translucent member 150 can be reflected at the interface between the first translucent member 150 and the third translucent member, and the brightness of the area directly above the light source 130 on the upper surface of the third translucent member can be prevented from becoming too high.

［光調整部材１４０］
面状光源１０００中の発光領域１００のそれぞれは、第１透光性部材１５０の上面１５０ａ上に位置する光調整部材１４０を有し得る。光調整部材１４０の材料には、第１光反射層３６または第２光反射層３８と同様の材料を用いることができる。光調整部材１４０に、第１光反射層３６または第２光反射層３８とは異なる材料を用いてもよい。光調整部材１４０は、例えば、多数の気泡を含む白色のポリエチレンテレフタラートの層であってもよい。 [Light adjustment member 140]
Each of the light-emitting regions 100 in the surface light source 1000 may have a light adjustment member 140 located on the upper surface 150a of the first light-transmissive member 150. The material of the light adjustment member 140 may be the same as that of the first light reflection layer 36 or the second light reflection layer 38. The light adjustment member 140 may be a material different from that of the first light reflection layer 36 or the second light reflection layer 38. The light adjustment member 140 may be, for example, a layer of white polyethylene terephthalate containing a large number of air bubbles.

光調整部材１４０は、典型的には、導光部材１２０の上面１２０ａ側において第１貫通孔２０ｈの全体を覆う。光調整部材１４０は、発光領域１００の発光面のうち、第１透光性部材１５０の上面１５０ａ上に選択的に配置されてもよいし、その一部が導光部材１２０の上面１２０ａ上に配置されてもよい。光調整部材１４０の上面視における形状は、第１貫通孔２０ｈの開口２０ａの形状に相似でなくてもよいし、相似であってもよい。 The light adjustment member 140 typically covers the entire first through hole 20h on the upper surface 120a side of the light-guiding member 120. The light adjustment member 140 may be selectively disposed on the upper surface 150a of the first translucent member 150, which is part of the light-emitting surface of the light-emitting region 100, or a part of the light adjustment member 140 may be disposed on the upper surface 120a of the light-guiding member 120. The shape of the light adjustment member 140 in a top view does not have to be similar to the shape of the opening 20a of the first through hole 20h, but may be similar.

［支持体１１０］
支持体１１０は、導光部材１２０の上面１２０ａとは反対側の下面１２０ｂ側に位置し、導光部材１２０を支持する。支持体１１０の例は、フレキシブルプリント基板である。支持体１１０は、両面プリント基板であってもよいし、片面プリント基板であってもよい。 [Support 110]
The support 110 is located on a lower surface 120b side of the light guide member 120 opposite to an upper surface 120a thereof, and supports the light guide member 120. An example of the support 110 is a flexible printed circuit board. The support 110 may be a double-sided printed circuit board or a single-sided printed circuit board.

支持体１１０は、光源１３０の電極３２ｅに対応する位置に第２貫通孔１０ｈを有する。第２貫通孔１０ｈ内には、光源の電極３２ｅを支持体１１０の下面１１０ｂ上の配線層１１６に電気的に接続する導電部１６０が配置される。 The support 110 has a second through hole 10h at a position corresponding to the electrode 32e of the light source 130. A conductive part 160 is disposed in the second through hole 10h, and electrically connects the electrode 32e of the light source to the wiring layer 116 on the lower surface 110b of the support 110.

図２に示す例では、支持体１１０の下面１１０ｂは、例えば樹脂から形成される絶縁層１７０で覆われている。絶縁層１７０は、支持体１１０の下面１１０ｂ上の配線層１１６と、導電部１６０の一部とを覆う。 In the example shown in FIG. 2, the lower surface 110b of the support 110 is covered with an insulating layer 170 made of, for example, resin. The insulating layer 170 covers the wiring layer 116 on the lower surface 110b of the support 110 and a part of the conductive portion 160.

［第１接着層１１２］
第１接着層１１２は、支持体１１０と光反射性シート１１４との間に配置され、光反射性シート１１４を支持体１１０の上面１１０ａに固定する。第１接着層１１２は、例えば、アクリルなどの樹脂材料で構成される接着層であり得る。ボンディングシートなどの、接着剤の層を有する公知の樹脂シートを第１接着層１１２として用いてもよい。後述の第２接着層１８０と同様に、第１接着層１１２は、光反射性を有していてもよい。 [First adhesive layer 112]
The first adhesive layer 112 is disposed between the support 110 and the light-reflecting sheet 114, and fixes the light-reflecting sheet 114 to the upper surface 110a of the support 110. The first adhesive layer 112 may be an adhesive layer made of a resin material such as acrylic. A known resin sheet having an adhesive layer, such as a bonding sheet, may be used as the first adhesive layer 112. Like the second adhesive layer 180 described below, the first adhesive layer 112 may have light reflectivity.

［光反射性シート１１４］
光反射性シート１１４は、支持体１１０と、光源１３０との間に位置し、導光部材１２０内部において支持体１１０側に向かって進行する光を導光部材１２０の上面１２０ａに向けて反射させることにより、光の取出し効率を向上させる。 [Light Reflecting Sheet 114]
The light-reflective sheet 114 is located between the support 110 and the light source 130, and improves the light extraction efficiency by reflecting light traveling inside the light-guiding member 120 toward the support 110 toward the upper surface 120a of the light-guiding member 120.

光反射性シート１１４は、例えば白色の部材であり、光反射性シート１１４の材料としては、光拡散材として光反射性のフィラーを含有する樹脂材料を適用できる。光反射性シート１１４は、例えば、ポリエチレンテレフタラートを母材として含む樹脂シートであり得る。光拡散材としては、例えば二酸化チタンの粒子を用いることができる。母材中に光拡散材を含有する材料で光反射性シート１１４を構成することに代えて、多数の気泡を含む白色のポリエチレンテレフタラートのシートを光反射性シート１１４として用いてもよい。 The light-reflective sheet 114 is, for example, a white member, and the material of the light-reflective sheet 114 can be a resin material containing a light-reflective filler as a light diffusion material. The light-reflective sheet 114 can be, for example, a resin sheet containing polyethylene terephthalate as a base material. The light diffusion material can be, for example, titanium dioxide particles. Instead of forming the light-reflective sheet 114 from a material containing a light diffusion material in the base material, a white polyethylene terephthalate sheet containing a large number of air bubbles can be used as the light-reflective sheet 114.

［第２接着層１８０］
第２接着層１８０としては、接着剤の層を有する公知の樹脂シートを用いることができる。例えば、シート状の光学用透明粘着剤（ＯＣＡ）を第２接着層１８０に適用できる。 [Second adhesive layer 180]
A known resin sheet having an adhesive layer can be used as the second adhesive layer 180. For example, a sheet-shaped optically clear adhesive (OCA) can be applied to the second adhesive layer 180.

第２接着層１８０は、例えば光反射性のフィラーを含有することにより、光反射性を有していてもよい。第２接着層１８０が光反射性を有することにより、光源から導光部材１２０に導入されて導光部材１２０の下面に向かう光を第２接着層１８０により導光部材１２０の上面１２０ａに向けて反射させることができ、光の取出し効率が向上する。 The second adhesive layer 180 may have light reflectivity, for example by containing a light-reflective filler. By making the second adhesive layer 180 light-reflective, light introduced from the light source into the light-guiding member 120 toward the lower surface of the light-guiding member 120 can be reflected by the second adhesive layer 180 toward the upper surface 120a of the light-guiding member 120, improving the light extraction efficiency.

（面状光源の製造方法）
以下、面状光源１０００の例示的な製造方法の概略を説明する。 (Method of manufacturing a surface light source)
An exemplary method for manufacturing the surface light source 1000 will now be outlined.

まず、図１０に示すように、下面１１０ｂ側に配線層１１６が配置された支持体１１０を準備する。配線層１１６は、銅などの導電材料から形成され得る。支持体１１０の上面１１０ａには、第１接着層１１２により光反射性シート１１４を接着する。図１０に示す例では、光反射性シート１１４上にさらに第２接着層１８０を配置している。支持体１１０は、購入によって準備されてもよい。 First, as shown in FIG. 10, a support 110 is prepared with a wiring layer 116 disposed on the lower surface 110b side. The wiring layer 116 may be formed of a conductive material such as copper. A light-reflective sheet 114 is adhered to the upper surface 110a of the support 110 by a first adhesive layer 112. In the example shown in FIG. 10, a second adhesive layer 180 is further disposed on the light-reflective sheet 114. The support 110 may be prepared by purchase.

次に、光源１３０の配置される領域ごとに一対の第２貫通孔１０ｈを支持体１１０に形成する。支持体１１０の上面１１０ａ側に複数の光源１３０を例えば複数の行および列に配置する場合には、支持体１１０に、第２貫通孔１０ｈの組が複数の行および列に設けられる。図１１に示す例では、第１接着層１１２、光反射性シート１１４および第２接着層１８０の積層体にも、支持体１１０の第２貫通孔１０ｈに連通する貫通孔を形成している。 Next, a pair of second through holes 10h are formed in the support 110 for each region where the light sources 130 are arranged. When multiple light sources 130 are arranged on the upper surface 110a side of the support 110, for example, in multiple rows and columns, pairs of second through holes 10h are provided in multiple rows and columns in the support 110. In the example shown in FIG. 11, a through hole that communicates with the second through hole 10h of the support 110 is also formed in the laminate of the first adhesive layer 112, the light reflective sheet 114, and the second adhesive layer 180.

第２貫通孔１０ｈは、パンチングまたはレーザ加工などにより形成できる。支持体１１０への第２貫通孔１０ｈの形成の際、第１接着層１１２、光反射性シート１１４および第２接着層１８０にも一括して貫通孔を形成してよい。貫通孔の開口の形状は、円形状に限定されず、任意の形状であってよい。例えば、貫通孔の開口の形状は、角部が丸みを帯びた三角形などの略多角形であってもよい。貫通孔の開口の形状は、電極３２ｅの下面３２ｅｂの外形にしたがった形状、例えば、下面３２ｅｂの外形に相似な形状であってもよい。 The second through-hole 10h can be formed by punching or laser processing. When forming the second through-hole 10h in the support 110, through-holes may also be formed in the first adhesive layer 112, the light-reflective sheet 114, and the second adhesive layer 180 at the same time. The shape of the opening of the through-hole is not limited to a circular shape and may be any shape. For example, the shape of the opening of the through-hole may be a substantially polygonal shape such as a triangle with rounded corners. The shape of the opening of the through-hole may be a shape that follows the outer shape of the lower surface 32eb of the electrode 32e, for example, a shape similar to the outer shape of the lower surface 32eb.

次に、透光性を有する、例えば樹脂シートを準備し、樹脂シートの所定の箇所に第１貫通孔２０ｈを形成することにより、導光部材１２００を得る。第１貫通孔２０ｈの形成方法に特に限定は無く、パンチングまたはレーザ加工などを適用し得る。導光部材１２００は、単層構造に限定されず、積層構造を有していてもよい。例えば、複数の透光性シートの積層後に第１貫通孔２０ｈを形成することにより、導光部材１２００を得てもよい。 Next, a light-transmitting sheet, for example a resin sheet, is prepared, and the first through-hole 20h is formed in a predetermined location of the resin sheet to obtain the light-guiding member 1200. There is no particular limitation on the method for forming the first through-hole 20h, and punching or laser processing may be applied. The light-guiding member 1200 is not limited to a single-layer structure, and may have a laminated structure. For example, the light-guiding member 1200 may be obtained by forming the first through-hole 20h after laminating multiple light-transmitting sheets.

導光部材１２００の準備後、第２接着層１８０によって導光部材１２００を光反射性シート１１４に接合する。このとき、図１２に示すように、支持体１１０に設けられた一対の第２貫通孔１０ｈが、支持体１１０の上面１１０ａの法線方向に見た上面視において導光部材１２００の第１貫通孔２０ｈの内側に位置するようにして、第２接着層１８０上に導光部材１２００を配置する。 After preparing the light guide member 1200, the light guide member 1200 is bonded to the light reflecting sheet 114 by the second adhesive layer 180. At this time, as shown in FIG. 12, the light guide member 1200 is placed on the second adhesive layer 180 so that a pair of second through holes 10h provided in the support 110 are positioned inside the first through holes 20h of the light guide member 1200 when viewed from above in the normal direction of the upper surface 110a of the support 110.

図１２に示す例では、導光部材１２００の上面１２００ａに表れた、第１貫通孔２０ｈの開口２０ａは、円形状を有している。また、第１貫通孔２０ｈの内側面２０ｃは、支持体１１０の上面１１０ａに対して垂直である。すなわち、この例では、第１貫通孔２０ｈは、円柱形状を有する。第１貫通孔２０ｈの形状は、円柱形状に限定されず、求める光学特性に応じて適宜変更され得る。 In the example shown in FIG. 12, the opening 20a of the first through hole 20h that appears on the upper surface 1200a of the light-guiding member 1200 has a circular shape. The inner surface 20c of the first through hole 20h is perpendicular to the upper surface 110a of the support 110. That is, in this example, the first through hole 20h has a cylindrical shape. The shape of the first through hole 20h is not limited to a cylindrical shape and can be changed as appropriate depending on the desired optical characteristics.

その後、必要に応じて、ダイシングブレード、超音波カッターなどを用いて導光部材１２００に複数の溝部２０ｇを形成する。図１３に示す例では、溝部２０ｇの形成により、導光部材１２００が複数の導光部材１２０に分割される。なお、この例では、溝部２０ｇは、第２接着層１８０まで達しており、複数の導光部材１２０は、互いに空間的に分離されている。あるいは、第１接着層１１２に達する深さで溝部２０ｇを形成することにより、導光部材１２００と同様に、第２接着層１８０および光反射性シート１１４のそれぞれを複数の部分に分割してもかまわない。なお、溝部２０ｇが第２接着層１８０まで達していることは、本開示の実施形態において必須ではない。複数の導光部材１２０が互いに空間的に分離されないこともあり得る。 After that, if necessary, a plurality of grooves 20g are formed in the light guide member 1200 using a dicing blade, an ultrasonic cutter, or the like. In the example shown in FIG. 13, the light guide member 1200 is divided into a plurality of light guide members 120 by forming the grooves 20g. In this example, the grooves 20g reach the second adhesive layer 180, and the plurality of light guide members 120 are spatially separated from each other. Alternatively, the second adhesive layer 180 and the light reflective sheet 114 may each be divided into a plurality of parts, similar to the light guide member 1200, by forming the grooves 20g to a depth that reaches the first adhesive layer 112. In addition, it is not essential in the embodiment of the present disclosure that the grooves 20g reach the second adhesive layer 180. The plurality of light guide members 120 may not be spatially separated from each other.

次に、図１４に示すように、別途に準備した光源１３０を、第２接着層１８０のうち導光部材１２０の第１貫通孔２０ｈ内に露出された部分上に配置する。光源１３０の配置に際しては、第２接着層１８０に形成された貫通孔、あるいは、導光部材１２０の第１貫通孔２０ｈの開口２０ａを位置合わせの基準に利用できる。具体的には、光源１３０に含まれる発光素子３２の電極３２ｅが上面視において支持体１１０の第２貫通孔１０ｈに重なるように光源１３０を第２接着層１８０上に配置する。支持体１１０の第２貫通孔１０ｈは、光源１３０の配置により閉塞される。 Next, as shown in FIG. 14, a separately prepared light source 130 is placed on a portion of the second adhesive layer 180 exposed in the first through hole 20h of the light guide member 120. When placing the light source 130, the through hole formed in the second adhesive layer 180 or the opening 20a of the first through hole 20h of the light guide member 120 can be used as a reference for alignment. Specifically, the light source 130 is placed on the second adhesive layer 180 so that the electrode 32e of the light emitting element 32 included in the light source 130 overlaps the second through hole 10h of the support 110 in a top view. The second through hole 10h of the support 110 is blocked by the placement of the light source 130.

支持体１１０の第２貫通孔１０ｈが光源１３０によって閉塞されていることを確認後、第２貫通孔１０ｈ内に導電部１６０を配置する。典型的には、導電部１６０の形成工程では、例えば、支持体１１０、第１接着層１１２、光反射性シート１１４および第２接着層１８０に設けられた貫通孔を導電ペーストで充填した後、加熱により導電ペーストを硬化させる。このとき、導電ペーストは、支持体１１０の下面１１０ｂに配置された配線層１１６に接触するように、配線層１１６上まで延ばされ得る。導電ペーストの硬化により、図１５に示すように、一端が光源１３０の電極３２ｅに接続された導電部１６０を得られる。 After confirming that the second through-hole 10h of the support 110 is blocked by the light source 130, the conductive portion 160 is placed in the second through-hole 10h. Typically, in the process of forming the conductive portion 160, for example, the through-holes provided in the support 110, the first adhesive layer 112, the light-reflective sheet 114, and the second adhesive layer 180 are filled with a conductive paste, and the conductive paste is then hardened by heating. At this time, the conductive paste can be extended onto the wiring layer 116 arranged on the lower surface 110b of the support 110 so as to contact the wiring layer 116. By hardening the conductive paste, a conductive portion 160 is obtained, one end of which is connected to the electrode 32e of the light source 130, as shown in FIG. 15.

次に、ポッティングなどにより、導光部材１２０の第１貫通孔２０ｈ内を透光性の樹脂材料で充填する。樹脂材料の硬化により、図１５に示すように、光源１３０を覆う第１透光性部材１５０を第１貫通孔２０ｈ内に形成できる。このとき、第１貫通孔２０ｈ内に配置される樹脂材料の粘度などをフィラーの含有量などによって調整することにより、例えば樹脂材料の硬化収縮を利用して、第１貫通孔２０ｈの下側の隅部に空隙ＧＰを形成し得る。第１貫通孔２０ｈ内に配置される樹脂材料は、例えば０．１Ｐａ・ｓ以上３．０Ｐａ・ｓ以下の範囲の粘度を有することが好ましい。ポッティングにより第１貫通孔２０ｈ内を樹脂材料で充填する場合、まず光源１３０の周囲に樹脂材料を付与し、続けて光源１３０の上方に樹脂材料を付与することが好ましい。 Next, the first through-hole 20h of the light-guiding member 120 is filled with a translucent resin material by potting or the like. As shown in FIG. 15, the first translucent member 150 covering the light source 130 can be formed in the first through-hole 20h by hardening the resin material. At this time, by adjusting the viscosity of the resin material placed in the first through-hole 20h by the filler content, for example, by utilizing the hardening shrinkage of the resin material, a gap GP can be formed in the lower corner of the first through-hole 20h. The resin material placed in the first through-hole 20h preferably has a viscosity in the range of, for example, 0.1 Pa·s to 3.0 Pa·s. When filling the first through-hole 20h with a resin material by potting, it is preferable to first apply the resin material around the light source 130, and then apply the resin material above the light source 130.

図１５に示す例では、第１透光性部材１５０の上面１５０ａは、導光部材１２０の上面１２０ａに整合している。第１透光性部材１５０の上面１５０ａは、概ね平坦な面であってもよいし、曲面であってもよい。第１透光性部材１５０の上面１５０ａは、導光部材１２０の上面１２０ａに対して盛り上がった形状、あるいは、導光部材１２０の上面１２０ａの位置から支持体１１０に向かって窪んだ形状であってもよい。 In the example shown in FIG. 15, the upper surface 150a of the first light-transmissive member 150 is aligned with the upper surface 120a of the light-guiding member 120. The upper surface 150a of the first light-transmissive member 150 may be a generally flat surface or a curved surface. The upper surface 150a of the first light-transmissive member 150 may be raised relative to the upper surface 120a of the light-guiding member 120, or may be recessed from the position of the upper surface 120a of the light-guiding member 120 toward the support 110.

第１透光性部材１５０の形成後、第１透光性部材１５０の上面１５０ａ上に光調整部材１４０を配置してもよい。図１６に示すように、光調整部材１４０は、第１透光性部材１５０の上面１５０ａだけでなく、導光部材１２０の上面１２０ａの一部をも覆っていてもよい。 After the first translucent member 150 is formed, the light adjustment member 140 may be disposed on the upper surface 150a of the first translucent member 150. As shown in FIG. 16, the light adjustment member 140 may cover not only the upper surface 150a of the first translucent member 150, but also a portion of the upper surface 120a of the light guide member 120.

さらに、図１６に示す例のように、導電部１６０のうち支持体１１０の下面１１０ｂ上に現れた部分と、配線層１１６とを覆う絶縁層１７０を支持体１１０の下面１１０ｂ側に配置してもよい。絶縁層１７０は、エポキシ樹脂、ウレタン樹脂またはアクリル樹脂などから例えば印刷および紫外線の照射により形成され、導電部１６０および配線層１１６を保護する機能を有する。なお、光調整部材１４０を形成する工程と、絶縁層１７０を形成する工程とは、いずれが先に実行されてもかまわない。絶縁層１７０の形成の後に光調整部材１４０が形成されることもあり得る。 Furthermore, as shown in the example of FIG. 16, an insulating layer 170 may be disposed on the lower surface 110b side of the support 110 to cover the portion of the conductive portion 160 that appears on the lower surface 110b of the support 110 and the wiring layer 116. The insulating layer 170 is formed from epoxy resin, urethane resin, acrylic resin, or the like, for example, by printing and irradiating with ultraviolet light, and has the function of protecting the conductive portion 160 and the wiring layer 116. It does not matter which of the process of forming the light adjustment member 140 and the process of forming the insulating layer 170 is performed first. The light adjustment member 140 may be formed after the insulating layer 170 is formed.

必要に応じ、導光部材１２００を支持する構造の外形を切断によって整え、延伸部１１０ｔを形成する。以上の工程により、図１に示す面状光源１０００を得られる。 If necessary, the outer shape of the structure supporting the light-guiding member 1200 is adjusted by cutting to form the extension portion 110t. Through the above steps, the surface light source 1000 shown in Figure 1 is obtained.

本開示の実施形態は、液晶表示装置用バックライトなどに有利に適用できる。本開示の実施形態は、厚さ低減の要求が厳しいモバイル機器の表示装置用のバックライト、ローカルディミングが要求される面発光装置などに好適に適用できる。 Embodiments of the present disclosure can be advantageously applied to backlights for liquid crystal display devices.Embodiments of the present disclosure can be suitably applied to backlights for display devices of mobile devices that have strict requirements for reducing thickness, and surface-emitting devices that require local dimming.

２０ａ、２０ｂ 第１貫通孔の開口
２０ｃ 第１貫通孔の内側面
２０ｈ 第１貫通孔
３２ 発光素子
３４ 第２透光性部材
３６ 第１光反射層
３８ 第２光反射層
１００ 発光領域
１１０ 支持体
１１２ 第１接着層
１１４ 光反射性シート
１１６ 配線層
１２０ 導光部材
１３０ 光源
１４０ 光調整部材
１５０ 第１透光性部材
１６０ 導電部
１７０ 絶縁層
１８０ 第２接着層
１０００ 面状光源
１１００ 配線基板
１２００ 導光部材
ＧＰ、ＧＰ１～ＧＰ４ 空隙
Ｒ１ 第１領域 20a, 20b Opening of first through hole 20c Inner surface of first through hole 20h First through hole 32 Light emitting element 34 Second light transmissive member 36 First light reflective layer 38 Second light reflective layer 100 Light emitting region 110 Support 112 First adhesive layer 114 Light reflective sheet 116 Wiring layer 120 Light guiding member 130 Light source 140 Light adjustment member 150 First light transmissive member 160 Conductive portion 170 Insulating layer 180 Second adhesive layer 1000 Planar light source 1100 Wiring board 1200 Light guiding member GP, GP1 to GP4 Gap R1 First region

Claims (9)

上面を有する配線基板と、
前記配線基板の前記上面側に位置する導光部材であって、第１主面、前記第１主面の反対側に位置する第２主面、および、前記第１主面から前記第２主面に達する第１貫通孔を規定する少なくとも１つの内側面を有する導光部材と、
前記第１貫通孔内に位置し、前記配線基板に接続された光源と、
前記第１貫通孔内において前記光源を覆う第１透光性部材であって、前記第１貫通孔の前記内側面に部分的に接する第１透光性部材と
を備え、
前記第１透光性部材の表面は、前記第１貫通孔内に、前記第１貫通孔の前記内側面および前記配線基板の前記上面から離れている第１領域を含み、
前記第１領域は、前記第１透光性部材の上面の反対側に位置する、面状光源。 A wiring substrate having an upper surface;
a light guiding member located on the upper surface side of the wiring board, the light guiding member having a first main surface, a second main surface located opposite to the first main surface, and at least one inner side surface defining a first through hole extending from the first main surface to the second main surface;
a light source located in the first through hole and connected to the wiring substrate;
a first light-transmitting member that covers the light source in the first through hole and is in partial contact with the inner surface of the first through hole;
a surface of the first light-transmissive member includes , within the first through hole, a first region that is spaced apart from the inner side surface of the first through hole and the top surface of the wiring substrate;
The first region is located on the opposite side of the upper surface of the first light-transmissive member . 前記第１透光性部材の表面の前記第１領域は、前記第１透光性部材よりも小さな屈折率を有する媒質と前記第１透光性部材との間の境界面を構成している、請求項１に記載の面状光源。 The surface light source according to claim 1, wherein the first region on the surface of the first translucent member constitutes an interface between the first translucent member and a medium having a smaller refractive index than the first translucent member. 前記配線基板と前記導光部材との間に配置された接着層をさらに備え、
前記媒質は、前記第１貫通孔の前記内側面、前記接着層の上面および前記第１透光性部材の表面の前記第１領域に囲まれた空間に位置する空気である、請求項２に記載の面状光源。 An adhesive layer is further provided between the wiring board and the light guide member,
The surface light source according to claim 2 , wherein the medium is air located in a space surrounded by the inner side surface of the first through hole, an upper surface of the adhesive layer , and the first region on the surface of the first light-transmissive member. 前記第１透光性部材の表面の前記第１領域は、前記配線基板の前記上面に垂直な断面において、凹状を有している、請求項１から３のいずれか１項に記載の面状光源。 The surface light source according to any one of claims 1 to 3, wherein the first region of the surface of the first light-transmitting member has a concave shape in a cross section perpendicular to the upper surface of the wiring board. 前記第１透光性部材の表面の前記第１領域は、前記配線基板の前記上面に垂直な断面において、凸状を有している、請求項１から３のいずれか１項に記載の面状光源。 The surface light source according to any one of claims 1 to 3, wherein the first region of the surface of the first light-transmitting member has a convex shape in a cross section perpendicular to the upper surface of the wiring board. 前記導光部材の前記第２主面は、前記第１主面よりも前記配線基板の前記上面の近くに位置し、
前記配線基板の法線方向において、前記導光部材の前記第２主面から前記第１透光性部材の表面の前記第１領域までの最大距離は、前記導光部材の前記第２主面から前記光源の上面までの最大距離よりも小さい、請求項１から５のいずれか１項に記載の面状光源。 the second main surface of the light guiding member is located closer to the top surface of the wiring substrate than the first main surface,
6. The surface light source according to claim 1, wherein in a normal direction of the wiring substrate, a maximum distance from the second main surface of the light guiding member to the first region of the surface of the first translucent member is smaller than a maximum distance from the second main surface of the light guiding member to an upper surface of the light source. 前記第１透光性部材の表面の前記第１領域は、前記配線基板の法線方向に見た上面視において、それぞれが前記第１貫通孔の前記内側面に沿って延びる複数の部分を含む、請求項１から６のいずれか１項に記載の面状光源。 The surface light source according to any one of claims 1 to 6, wherein the first region of the surface of the first light-transmissive member includes a plurality of portions each extending along the inner side surface of the first through hole in a top view seen in a normal direction of the wiring board. 前記光源は、
発光素子と、
前記発光素子の上面および側面を覆う第２透光性部材と、
前記第２透光性部材上の第１光反射層と
を含む、請求項１から７のいずれか１項に記載の面状光源。 The light source is
A light-emitting element;
a second light-transmitting member covering an upper surface and a side surface of the light-emitting element;
The surface light source according to claim 1 , further comprising: a first light reflecting layer on the second light-transmissive member. 前記第１透光性部材上に位置する光調整部材をさらに備える、請求項１から８のいずれか１項に記載の面状光源。
 The surface light source according to claim 1 , further comprising a light adjusting member located on the first light-transmissive member.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011035030A (en) 2009-07-30 2011-02-17 Kyocera Corp Light-emitting device
WO2012030085A1 (en) 2010-09-03 2012-03-08 Lg Innotek Co., Ltd. Backlight unit and method for manufacturing the same
JP2021192362A (en) 2020-06-04 2021-12-16 日亜化学工業株式会社 Planar light source and method for manufacturing planar light source

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011035030A (en) 2009-07-30 2011-02-17 Kyocera Corp Light-emitting device
WO2012030085A1 (en) 2010-09-03 2012-03-08 Lg Innotek Co., Ltd. Backlight unit and method for manufacturing the same
JP2021192362A (en) 2020-06-04 2021-12-16 日亜化学工業株式会社 Planar light source and method for manufacturing planar light source

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