JP7293574B2 - Planar light source and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD Embodiments relate to a planar light source and a manufacturing method thereof.

A planar light source, which includes a wiring board, a light source arranged on the wiring board, and a light guide member arranged on the wiring board and surrounding the light source, is widely used, for example, as a backlight for a liquid crystal display. ing.

As for the wiring board, there is known a configuration having an insulating layer and two wiring layers provided under the insulating layer and corresponding to two electrodes in the light source. As a structure for electrically connecting each wiring layer and an electrode corresponding to each wiring layer in such a wiring board, two through holes are provided in an insulating layer, and a conductive member is arranged in each through hole. Structures connected to corresponding electrodes and corresponding wiring layers are known.

JP 2015-192095 A

An object of the present embodiment is to provide a planar light source capable of suppressing the occurrence of poor connection in an electrical connection structure between a wiring layer on a wiring substrate and an electrode of the light source, and a method of manufacturing the same.

A planar light source according to an embodiment includes an insulating layer provided with a first through hole and a second through hole separated from each other; a wiring board having a first wiring layer and a second wiring layer separated from each other; a light source arranged on the wiring board and having a first electrode and a second electrode separated from each other; arranged on the wiring board; a light guide member surrounding the light source; a first portion filling the first through hole and electrically connected to the first electrode; and the first portion disposed under the insulating layer. a first wiring member having a second portion connected to the first wiring layer and in contact with the first wiring layer; a third portion filling the second through hole and electrically connected to the second electrode; a second wiring member disposed under the insulating layer, connected to the third portion, and having a fourth portion in contact with the second wiring layer; Two wiring layers are arranged so as to sandwich the first through hole and the second through hole.

A planar light source according to an embodiment includes an insulating layer provided with a first through hole and a second through hole separated from each other; In the lower surface of the insulating layer, the periphery of the first through hole and the second through hole is formed so that the separated first wiring layer and second wiring layer, and the first through hole and the second through hole are exposed. a wiring board covering and exposing a part of the first wiring layer and the second wiring layer; and a first electrode and a second electrode arranged on the wiring board and separated from each other. a light source, a light guide member disposed on the wiring board and surrounding the light source, a first portion filling the first through hole and electrically connected to the first electrode, a second wiring member connected to one part and in contact with a portion of the first wiring layer exposed from the covering layer via a lower surface of the covering layer; a third portion filled and electrically connected to the second electrode; and a second wiring member having a contacting fourth portion.

A method for manufacturing a planar light source according to an embodiment includes an insulating layer provided with a first through hole and a second through hole separated from each other; a first wiring layer and a second wiring layer separated from the through-hole, and the first wiring layer and the second wiring layer sandwich the first through-hole and the second through-hole when viewed from above. arranging a light guide member and a light source on the wiring substrate; filling the first through hole, arranged under the insulating layer, a first wiring member in contact with one wiring layer and electrically connected to the first electrode of the light source; forming a second wiring member in contact with the second wiring layer and electrically connected to the second electrode of the light source.

According to this embodiment, it is possible to provide a planar light source capable of suppressing the occurrence of poor connection in the electrical connection structure between the wiring layer of the wiring board and the electrode of the light source, and a method of manufacturing the same.

1 is a schematic top view showing a planar light source according to a first embodiment; FIG. FIG. 4 is a schematic top view showing an enlarged view of one light emitting region and its surroundings in the planar light source; FIG. 3 is a schematic cross-sectional view taken along line III-III of FIG. 2; FIG. 3 is a schematic top view showing an enlarged part of the wiring board; It is a typical bottom view which expands and shows a part of wiring board. 4 is a schematic cross-sectional view showing an enlarged light source in FIG. 3; FIG. 4 is a schematic top view showing an enlarged light source in FIG. 3; FIG. FIG. 3 is a schematic top view showing an enlarged view of part of the wiring board, part of the sheet laminate, and a light source; It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical bottom view which shows the manufacturing method of a planar light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. FIG. 4 is a schematic bottom view showing an enlarged central portion of the wiring board and end portions of the wiring board; It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical bottom view which shows the manufacturing method of a planar light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. FIG. 4 is a schematic cross-sectional view showing another example of the shapes of the first wiring member, the second wiring member, and the covering layer; FIG. 4 is a schematic cross-sectional view showing another example of the shapes of the first wiring member, the second wiring member, and the covering layer; It is a typical sectional view showing an enlarged part of a planar light source according to a second embodiment. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. FIG. 11 is a schematic top view showing an enlarged view of part of a wiring board, part of a sheet laminate, and a light source of a planar light source according to a third embodiment; It is a typical sectional view showing a planar light source concerning a 4th embodiment. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source concerning a 5th embodiment. It is a typical sectional view showing a planar light source concerning a 6th embodiment. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. FIG. 21 is a schematic bottom view showing an enlarged part of a light source and a wiring board in a planar light source according to a seventh embodiment; FIG. 31 is a schematic cross-sectional view taken along line XXXI-XXXI of FIG. 30; It is a typical bottom view showing other examples of a light source and a wiring board. It is a typical sectional view showing a manufacturing method of a plane light source. It is a typical sectional view showing a manufacturing method of a plane light source. FIG. 21 is a schematic bottom view showing an enlarged part of a wiring board in a planar light source according to an eighth embodiment; FIG. 21 is a schematic top view showing a planar light source according to a ninth embodiment; FIG. 35 is a schematic top view showing an enlarged area surrounded by broken line XXXV in FIG. 34 in the light-emitting module according to the ninth embodiment; FIG. 36 is a schematic cross-sectional view taken along line XXXVI-XXXVI of FIG. 35; FIG. 35 is a schematic top view showing an enlarged area surrounded by XXXV in FIG. 34 and showing the wiring pattern in the light-emitting module according to the ninth embodiment. 35 is a schematic bottom view showing an enlarged portion surrounded by broken line XXXVIII in FIG. 34; FIG. FIG. 39 is a schematic bottom view showing an enlarged portion surrounded by broken line XXXIX in FIG. 38 in the wiring board according to the ninth embodiment; FIG. 39 is a schematic bottom view showing an enlarged portion surrounded by broken line XXXIX in FIG. 38 in the wiring board and the light emitting module according to the ninth embodiment; FIG. 41 is a schematic cross-sectional view along the XLI-XLI line in FIG. 40; FIG. 4 is a schematic bottom view showing another example of a wiring board; It is a typical bottom view which expands and shows some wiring boards in a modification.

<First Embodiment>
First, the first embodiment will be described.
FIG. 1 is a schematic top view showing a planar light source according to this embodiment.
FIG. 2 is a schematic top view showing an enlarged view of one light emitting region and its surroundings in the planar light source.
FIG. 3 is a schematic cross-sectional view taken along line III--III in FIG.
As shown in FIG. 3, the planar light source 100 according to the present embodiment includes a wiring board 110, a light source 120 arranged on the wiring board 110, and a light source 120 arranged on the wiring board 110. and a surrounding light guide member 130 . Each part of the planar light source 100 will be described in detail below.

Note that the XYZ orthogonal coordinate system is used in the following description. A direction from the wiring board 110 toward the light source 120 is defined as a "Z direction". One direction orthogonal to the Z direction is defined as the "X direction", and one direction orthogonal to the X direction and the Z direction is defined as the "Y direction". Also, the "Z direction" is also called the "upward direction", and the opposite direction is also called the "downward direction", but these expressions are for convenience and have nothing to do with the direction of gravity. In addition, viewing the object member directly with the naked eye from above, or viewing the target member through appropriate transmission is referred to as “top view”. In addition, viewing the target member directly with the naked eye from below or viewing through appropriate transmission is referred to as “bottom view”.

In addition, in the present embodiment, the light guide member 130 is provided with a plurality of light source arrangement portions 131 in the X direction and the Y direction, as shown in FIG. Each light source 120 is arranged in each light source arrangement portion 131 . However, the number of light sources to be arranged is not particularly limited as long as it is one or more. In addition, the light guide member 130 is provided with partition grooves 132 that partition the light emitting regions R of the light sources 120 when viewed from above. In the following, a portion positioned within one light emitting region R when viewed from the top will be mainly described, but portions positioned within another light emitting region R when viewed from the top can be configured in the same manner unless otherwise specified. .

As shown in FIG. 3 , the wiring board 110 includes a base layer 111 , a first covering layer 112 arranged on the base layer 111 , and a first covering layer 112 arranged below the base layer 111 corresponding to one light source 120 . It has a first wiring layer 113 , a second wiring layer 114 , and a second covering layer 115 provided under the base layer 111 .

The base layer 111 is made of an insulating material. Examples of the insulating material forming the base layer 111 include resin materials such as epoxy, silicone, liquid crystal polymer, polyimide (PI), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

The first covering layer 112 is made of an insulating material. Examples of the insulating material forming the first coating layer 112 include resin materials such as epoxy, silicone, liquid crystal polymer, polyimide (PI), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

In this specification, an insulating layer positioned above the first wiring layer and the second wiring layer in the wiring board is referred to as an "insulating layer". Therefore, in this embodiment, the base layer 111 and the first covering layer 112 correspond to the "insulating layer 116". However, the configuration of the insulating layer is not limited to the above. For example, an insulating adhesive layer may be arranged between the base layer and the first covering layer in the wiring board. In this case, the base layer, the first covering layer, and the adhesive layer correspond to the insulating layer. Also, for example, the first covering layer may not be provided on the base layer. In this case, only the base layer corresponds to the insulating layer. Also, the first wiring layer and the second wiring layer may be arranged under the second covering layer. In this case, the first covering layer, the base layer, and the second covering layer correspond to the insulating layer. An insulating adhesive layer may be arranged between the first covering layer and the base layer and between the base layer and the second covering layer.

The insulating layer 116 is provided with a first through hole 116a and a second through hole 116b that are separated from each other. Each through hole 116a, 116b penetrates the insulating layer 116 in the Z direction (vertical direction). The inner surface of each through-hole 116a, 116b is substantially parallel to the Z direction, for example.

FIG. 4A is a schematic top view showing an enlarged part of the wiring board.
FIG. 4B is a schematic bottom view showing an enlarged portion of the wiring board.
As shown in FIG. 4A, each through-hole 116a, 116b has a circular shape when viewed from above. However, the shape of each through-hole when viewed from above is not limited to the above, and may be, for example, a polygon such as a square, a polygon with rounded corners, or a shape other than a circle such as an ellipse. The first through holes 116a and the second through holes 116b are arranged in the X direction. However, the first through holes and the second through holes may be arranged in the Y direction, or may be arranged in a direction crossing the X direction and the Y direction.

Each of the first wiring layer 113 and the second wiring layer 114 is made of a metal material such as copper (Cu). The first wiring layer 113 and the second wiring layer 114 are separated from each other. Each of the first wiring layer 113 and the second wiring layer 114 is separated from the first through hole 116a and the second through hole 116b.

The first wiring layer 113 has a tip portion 113a located on the light source 120 side, an intermediate portion 113b connected to the tip portion 113a, and an external connection portion located on the opposite side of the tip portion 113a in the intermediate portion 113b. Similarly, the second wiring layer 114 includes a tip portion 114a located on the light source 120 side, an intermediate portion 114b connected to the tip portion 114a, an external connection portion located on the opposite side of the tip portion 114a in the intermediate portion 114b, have The planar light source 100 is lit by power supply to the external connection portion.

The wiring board 110 may have a projecting region that projects outward from the end of the wiring board 110 in plan view, and the external connection portion may be arranged in the projecting region.

The external connection portion may be electrically connected to another member (for example, a substrate including a drive circuit). When electrically connecting the external connection portion to another member, a connector may be used, or a conductive sheet may be used from the viewpoint of thinning.

When viewed from above, the first wiring layer 113 and the second wiring layer 114 are arranged so as to sandwich the first through hole 116a and the second through hole 116b. In this specification, "the first wiring layer and the second wiring layer are arranged so as to sandwich the first through hole and the second through hole when viewed from the top" means that the first wiring layer and the second wiring layer are arranged when viewed from the top. means that the first through hole and the second through hole are arranged between and and the first wiring layer and the second wiring layer are not arranged between the first through hole and the second through hole . In this embodiment, the tip portion 113a of the first wiring layer 113 and the tip portion 114a of the second wiring layer 114 are arranged so as to sandwich the first through hole 116a and the second through hole 116b.

The top view shape of the tip portion 113a of the first wiring layer 113 is arcuate in this embodiment. As shown in FIG. 3, the front end portion 113a has a top surface 113c in contact with the insulating layer 116, a bottom surface 113d located on the opposite side of the top surface 113c, a side surface 113e located between the top surface 113c and the bottom surface 113d, including.

The side surface 113e is parallel to the Z direction. However, the side surface may be curved instead of being parallel to the Z direction. As shown in FIG. 4A, the side surface 113e includes a first region 113s1 facing the first through hole 116a in top view, a second region 113s2 located on the opposite side of the first region 113s1, and a first region 113s1 and the first region 113s1. and a third region 113s3 located between the second region 113s2.

The shape of the first region 113s1 when viewed from above is concave in a direction away from the first through hole 116a, and is, for example, an arc shape. The shape of the second region 113s2 when viewed from above is a shape curved in the same direction as the first region 113s1, and is, for example, an arc shape. The shape of the third region 113s3 in a top view is linear parallel to the Y direction. However, the shape of the first region, the shape of the second region, and the shape of the third region in top view are not limited to the above. For example, the shape of the first region and the shape of the second region may be linear parallel to the Y direction, and the shape of the third region may be linear parallel to the X direction.

The top view shape of the tip portion 114a of the second wiring layer 114 is arcuate in this embodiment. As shown in FIG. 3, the tip portion 114a has a top surface 114c in contact with the insulating layer 116, a bottom surface 114d opposite to the top surface 114c, a side surface 114e located between the top surface 114c and the bottom surface 114d, including.

The side surface 114e is parallel to the Z direction. However, the side surface may be curved instead of being parallel to the Z direction. As shown in FIG. 4A, the side surface 114e includes a first region 114s1 facing the second through hole 116b in top view, a second region 114s2 located on the opposite side of the first region 114s1, and a first region 114s1 and the first region 114s1. and a third region 114s3 located between the second region 114s2.

The shape of the first region 114s1 when viewed from above is concave in a direction away from the second through hole 116b, and is, for example, an arc shape. The shape of the second region 114s2 when viewed from above is curved in the same direction as the first region 114s1, and is, for example, an arc shape. The shape of the third region 114s3 in a top view is linear parallel to the Y direction. However, the shape of the first region, the shape of the second region, and the shape of the third region in top view are not limited to the above. For example, the shape of the first region and the shape of the second region may be linear parallel to the Y direction, and the shape of the third region may be linear parallel to the X direction.

Each of the intermediate portion 113b of the first wiring layer 113 and the intermediate portion 114b of the second wiring layer 114 extends in the Y direction. However, the direction in which each intermediate portion extends is not limited to the above. You may Also, the direction in which the first wiring layer extends may be different from the direction in which the second wiring layer extends.

The second coating layer 115 covers part of the lower surface of the base layer 111, as shown in FIG. 4B. Further, the second coating layer 115 is provided with a through hole 115a. The through hole 115a penetrates the second covering layer 115 in the Z direction (vertical direction). From the through hole 115a, another part of the base layer 111, a part of the front end portion 113a and the middle portion 113b of the first wiring layer 113, a part of the front end portion 114a and the middle portion 114b of the second wiring layer 114, which will be described later. A part of the first wiring member 151 and a part of the second wiring member 152 are exposed. As shown in FIG. 4A, the through hole 115a has an oval shape when viewed from above. However, the shape of the through hole when viewed from above is not limited to the above, and may be, for example, a polygon such as a quadrangle, or a circle.

The thickness of the wiring board 110 is, for example, 50 μm or more and 250 μm or less. When the thickness of the wiring board 110 is within the above range, deformation such as contraction or expansion of the insulating layer of the wiring board is likely to occur due to environmental changes such as temperature or humidity.

A light reflective sheet 117 is arranged on the wiring board 110 as shown in FIG. The light reflective sheet 117 is attached to the wiring board 110 with an adhesive sheet 118a. Light reflective sheet 117 reflects part of the light emitted from light source 120 . If the light reflecting sheet 117 is not arranged, part of the light from the light source 120 may be absorbed by the base layer 111 of the wiring board 110 and the base layer 111 may deteriorate. Therefore, by arranging the light reflective sheet 117 on the wiring board 110 , it is possible to suppress the light from the light source 120 from reaching the wiring board 110 . As a result, the absorption of light by the base layer 111 of the wiring substrate 110 can be suppressed, and deterioration of the base layer 111 can be suppressed. The light reflective sheet 117 is preferably arranged on the upper surface of the wiring substrate 110 except for the first through holes 116a and the second through holes 116b. Accordingly, since the light reflecting sheet 117 is arranged below the light source 120, light reaching the wiring substrate 110 can be further suppressed. In addition, since the light from the light source 120 is reflected by the light-reflecting sheet 117, the light from the light source 120 propagates farther from the light source 120 in the light guide member 130, thereby suppressing the luminance unevenness in the light emitting region R. can do. The light reflective sheet 117 can be composed of a resin sheet containing a large number of air bubbles (for example, a foamed resin sheet) or a resin sheet containing a light diffusing material. As the resin used for the light reflective sheet 117, for example, a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate (PET) or polyester, or a thermosetting resin such as epoxy or silicone can be used. . Titanium oxide, silica, alumina, zinc oxide, glass, or the like can be used as the light diffusing material.

The wiring members 151 and 152 may be made of a thermosetting material as a main component, and the light-reflecting sheet 117 may be made of a thermoplastic resin as a main component. At this time, the melting point of the light reflective sheet 117 is preferably higher than the curing temperature of the wiring members 151 and 152 . As a result, even when the wiring members 151 and 152 reach a temperature at which they harden, the light reflective sheet 117 does not melt, so that the light reflectivity of the light reflective sheet 117 can be prevented from deteriorating. If the main component of the wiring member is epoxy resin, the curing temperature of the wiring member is about 120 to 130 degrees. Moreover, if the main component of the light reflective sheet 117 is polyethylene terephthalate, the melting point of the light reflective sheet is approximately 220 degrees.

A light guide member 130 is arranged on the light reflective sheet 117 . The light guide member 130 is attached to the light reflective sheet 117 with an adhesive sheet 118b. The light reflective sheet 117 and the two adhesive sheets 118a and 118b are referred to as a "sheet laminate 119".

The sheet laminate 119 covers the upper surface of the wiring board 110 and exposes the first through holes 116a and the second through holes 116b. Specifically, the sheet stack 119 is provided with a third through-hole 119a positioned directly above the first through-hole 116a and a fourth through-hole 119b positioned directly above the second through-hole 116b. there is

The shape of the third through-hole 119a in top view is the same shape as the first through-hole 116a, for example, circular. The inner surface of the third through hole 119a is, for example, flush with the inner surface of the first through hole 116a and substantially parallel to the Z direction. The shape of the fourth through hole 119b in a top view is the same shape as the second through hole 116b, for example circular. The inner surface of the fourth through hole 119b is, for example, flush with the inner surface of the second through hole 116b and substantially parallel to the Z direction. That is, one substantially cylindrical through hole is formed by the first through hole 116a and the third through hole 119a, and one substantially cylindrical through hole is formed by the second through hole 116b and the fourth through hole 119b. A through hole is formed.

However, the configuration of the sheet laminate is not limited to the above. For example, instead of providing two through holes corresponding to the first through hole and the second through hole in the sheet laminate as described above, one through hole is provided directly above the first through hole and the second through hole. The single through hole may expose both the first through hole and the second through hole. Further, the planar light source may not be provided with the sheet laminate.

5A is a schematic cross-sectional view showing an enlarged light source in FIG. 3. FIG.
5B is a schematic top view showing an enlarged light source in FIG. 3. FIG.
FIG. 6 is a schematic top view enlarging a portion of the wiring board, a portion of the sheet laminate, and the light source.
The light source 120 has a light emitting element 124, a translucent member 125, a first light adjusting member 126, a covering member 127, a first terminal 122, and a second terminal 123, as shown in FIG. 5A. .

The light-emitting element 124 has a light-emitting portion 124a, and a first electrode 124b and a second electrode 124c arranged under the light-emitting portion 124a and separated from each other.

The light emitting part 124a has, for example, a semiconductor growth substrate and a semiconductor laminated structure arranged under the semiconductor growth substrate. The semiconductor laminated structure is configured to emit visible light or ultraviolet light, and any composition can be used according to the desired emission peak wavelength. The semiconductor laminated structure includes, for example, an In _x Al _y Ga _1-x-y N (0≦x, 0≦y, x+y≦1) layer, and blue light is emitted from the light emitting portion 124a. However, the color of the light emitted by the light emitting section is not limited to blue.

The semiconductor laminated structure includes an n-type semiconductor layer, a p-type semiconductor layer, and a light-emitting layer sandwiched therebetween. The light-emitting layer may have a structure such as a double heterojunction or a single quantum well (SQW), or may have a structure with a group of active layers such as a multiple quantum well (MQW). good.
In addition, the semiconductor laminated structure may have a structure including one or more light emitting layers between the n-type semiconductor layer and the p-type semiconductor layer, or the n-type semiconductor layer, the light emitting layer and the p-type semiconductor layer. You may have a structure in which a structure containing and in order is repeated multiple times. When the semiconductor laminated structure includes a plurality of light-emitting layers, it may include light-emitting layers with different emission peak wavelengths, or may include light-emitting layers with the same emission peak wavelength. In addition, the same emission peak wavelength includes the case where there is a variation of about several nanometers. A combination of emission peak wavelengths between a plurality of light-emitting layers can be selected as appropriate. For example, if the semiconductor stack includes two light-emitting layers, blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or , a combination of green light and red light, etc., to select the light-emitting layer. Each light-emitting layer may include a plurality of active layers with different emission peak wavelengths, or may include a plurality of active layers with the same emission peak wavelength.

The first electrodes 124b and the second electrodes 124c are arranged in the X direction. The shape of each of the electrodes 124b and 124c when viewed from the top is a substantially triangular shape with rounded corners, as shown in FIG. 5B. However, the shape of each electrode in top view is not limited to the above, and may be, for example, other polygonal shape such as square, circular shape, or elliptical shape.

As shown in FIG. 6, the distance D1 between the center c1 of the first through hole 116a and the center c2 of the second through hole 116b in top view is the distance between the center c3 of the first electrode 124b and the center c4 of the second electrode 124c. longer than the distance D2 (D1>D2). However, the distance between the center of the first through hole and the center of the second through hole may be equal to the distance between the center of the first electrode and the center of the second electrode. When the first electrode 124b is triangular, the center c3 of the first electrode 124b is the intersection of three lines connecting each vertex of the triangle and the midpoint of the side opposite to each vertex. be. The same applies to the center c4 of the second electrode 124c.

As shown in FIG. 5A, the translucent member 125 covers the upper and side surfaces of the light emitting section 124a. The translucent member 125 has translucency with respect to the light emitted from the light emitting section 124a. The translucent member 125 includes a base material made of a translucent material and a plurality of wavelength conversion particles dispersed in the base material. As the material of the base material, for example, silicone, epoxy, glass, or the like can be used. Phosphors, for example, can be used as the wavelength conversion particles. Examples of phosphors include yttrium-aluminum-garnet-based phosphors (e.g., YAG phosphor), lutetium-aluminum-garnet-based phosphors (e.g., Lu ₃ (Al, Ga) ₅ O ₁₂ :Ce), terbium- aluminum garnet-based phosphors (e.g., _Tb3 (Al, Ga) _{5O12 :} Ce), CCA-based phosphors (e.g., _Ca10 ( _PO4 ) _{6Cl2 :} Eu), SAE-based phosphors (e.g., Sr ₄ Al ₁₄ O ₂₅ :Eu), chlorosilicate-based phosphors (eg, Ca ₈ MgSi ₄ O ₁₆ Cl ₂ :Eu), β-sialon-based phosphors (eg, (Si, Al) ₃ (O, N) ₄ :Eu), α-sialon-based phosphors (for example, Mz(Si,Al) ₁₂ (O,N) ₁₆ :Eu (where 0<z≦2, and M is Li, Mg, Ca, Y, and La and lanthanide elements excluding Ce)), SLA phosphors (e.g. SrLiAl ₃ N ₄ :Eu), CASN phosphors (e.g. CaAlSiN ₃ :Eu) or SCASN phosphors (e.g. (Sr, Ca)AlSiN ₃ :Eu) and other nitride-based phosphors, KSF-based phosphors (e.g., K ₂ SiF ₆ :Mn), KSAF-based phosphors (e.g., K ₂ (Si, Al)F ₆ :Mn), or MGF-based phosphors Fluoride-based phosphors such as solids (e.g., _{3.5MgO.0.5MgF2.GeO2} :Mn), phosphors having _a perovskite structure (e.g., CsPb(F,Cl,Br,I) ₃ ), or quantum Dot phosphors (eg, CdSe, InP, AgInS ₂ or AgInSe ₂ ) or the like can be used. Translucent member 125 may contain multiple types of phosphors.

Also, the wavelength conversion sheet containing the phosphor described above may be arranged on the planar light source. The wavelength conversion sheet can be a planar light source that absorbs part of the blue light from the light source 120, emits yellow light, green light and/or red light, and emits white light. For example, white light can be obtained by combining a light source capable of emitting blue light and a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, a light source capable of emitting blue light may be combined with a wavelength conversion sheet containing a red phosphor and a green phosphor. Also, a light source capable of emitting blue light may be combined with a plurality of wavelength conversion sheets. As the plurality of wavelength conversion sheets, for example, a wavelength conversion sheet containing a phosphor capable of emitting red light and a wavelength conversion sheet containing a phosphor capable of emitting green light can be selected. Also, a light source having a light emitting element capable of emitting blue light, a translucent member containing a phosphor capable of emitting red light, and a wavelength conversion sheet containing a phosphor capable of emitting green light are combined. may

The light source 120 emits mixed light of light emitted from the wavelength conversion particles in the translucent member 125 and light emitted from the light emitting section 124a, and the color of the mixed light is white, for example. However, the translucent member may not be provided with the wavelength converting particles. In this case, the light source may emit only blue light emitted from the light emitting section.

The first light adjusting member 126 covers the top surface of the translucent member 125 . The first light adjusting member 126 reflects part of the light emitted from the light emitting section 124a and transmits another part of the light emitted from the light emitting section 124a. The first light adjustment member 126 is, for example, resin containing a light reflective material. Specifically, as the first light adjusting member 126, a resin such as silicone containing titanium oxide or epoxy can be used as a light reflecting material.

The covering member 127 covers the lower surface of the translucent member 125 and the lower surface of the light emitting section 124a. The covering member 127 is, for example, resin containing a light reflecting material. Specifically, as the coating member 127, resin such as silicone containing titanium oxide or epoxy can be used as a light-reflecting material.

The first terminal 122 and the second terminal 123 are made of metal material such as copper (Cu). The first terminal 122 is in contact with the lower end of the first electrode 124b, as shown in FIG. 5A. The second terminal 123 is in contact with the lower end of the second electrode 124c. The first terminal 122 and the second terminal 123 are separated from each other.

Hereinafter, the portion of the light source 120 excluding the two terminals 122 and 123 (the light emitting element 124, the translucent member 125, the first light adjusting member 126, and the covering member 127) will be referred to as a "main body portion 121".

As shown in FIG. 5B, the shape of the main body 121 in top view is, for example, a quadrangle. The body portion 121 is arranged such that one diagonal line L1 of the body portion 121 is parallel to the X direction and the other diagonal line L2 is parallel to the Y direction. That is, the main body part 121 is arranged such that four sides forming the outer periphery in top view are inclined at 45 degrees with respect to the X direction and the Y direction.

The two electrodes 124b and 124c are arranged so as to be substantially symmetrical with respect to the diagonal line L2 when viewed from above. As shown in FIG. 6, the two electrodes 124b, 124c and the two terminals 122, 123 are positioned on the diagonal line L1. The dimension of the main body portion 121 in top view is maximum on the diagonal line L1. Therefore, by arranging the two terminals 122 and 123 on the diagonal line L1, it is possible to prevent the two terminals 122 and 123 from approaching each other even when the light emitting element 124 has a small area when viewed from above. The two through holes 116 a and 116 b of the wiring board 110 are provided according to the positions of the two terminals 122 and 123 . Therefore, by suppressing the two terminals 122 and 123 from approaching each other, it is possible to suppress the two through holes 116a and 116b from approaching each other. As a result, the p-type semiconductor layer and the n-type semiconductor layer in the light emitting element 124 can be prevented from being electrically connected and short-circuited. However, the main body may be arranged such that each diagonal line is inclined with respect to the X direction and the Y direction when viewed from above. Also, the shape of the main body of the light source when viewed from above is not limited to the above, and may be, for example, a polygon other than a quadrangle such as a pentagon, or a circle. Also, the positions of the two electrodes are not limited to the above.

A portion of the first electrode 124b overlaps the first through hole 116a in the present embodiment when viewed from above. As a result, the distance between the first electrode 124b and a first wiring member 151, which will be described later, can be shortened, and the resistance between the first electrode 124b and the first wiring member 151 can be reduced. The same applies to the second electrode 124c. However, each electrode may cover the entire area of the corresponding through hole when viewed from above. Further, each electrode does not have to overlap the corresponding through hole when viewed from above.

The shape of the first terminal 122 in top view is triangular as shown in FIG. 5B. Thereby, the connection area between the first terminal 122 and the first wiring member 151 described later can be increased. The shape of the second terminal 123 when viewed from above is a shape obtained by cutting out a part of a triangle that is symmetrical with the first terminal 122 with respect to the diagonal line L2. This makes it easy to distinguish between the positive electrode and the negative electrode. However, the shape of each terminal is not limited to the above. Also, the shape of the first terminal and the shape of the second terminal may be the same.

The area of the first terminal 122 in top view is larger than the area of the first electrode 124b. Similarly, the area of the second terminal 123 in top view is larger than the area of the second electrode 124c. However, the area of the first terminal in top view may be equal to the area of the first electrode, and the area of the second terminal in top view may be equal to the area of the second electrode.

As shown in FIG. 6, in top view, the first terminal 122 covers the first through hole 116a, and the second terminal 123 covers the second through hole 116b. Specifically, as shown in FIG. 3, the first terminal 122 closes the upper opening of the third through-hole 119a located directly above the first through-hole 116a, and the second terminal 123 closes the second through-hole 119a. It closes the upper opening of the fourth through hole 119b located directly above 116b. However, if the planar light source is not provided with the sheet laminate, the first terminal may close the upper opening of the first through hole, and the second terminal may close the upper opening of the second through hole.

Note that the configuration of the light source is not limited to the above. For example, the light source may not be provided with terminals. When the light source is not provided with the first terminal, the first electrode is electrically connected to the first wiring member, and the second electrode is electrically connected to the second wiring member. Also, the number of light emitting elements constituting the light source may be two or more. In this case, the positive electrode of each light emitting element may be electrically connected to the same wiring layer in the wiring substrate, or may be electrically connected to different wiring layers. The same applies to the negative electrode of each light emitting element. Alternatively, the light source may be composed only of light emitting elements.

The first wiring layer 113 and the first electrode 124 b are electrically connected by the first terminal 122 and the first wiring member 151 . The second wiring layer 114 and the second electrode 124 c are electrically connected by the second terminal 123 and the second wiring member 152 .

Each of the wiring members 151 and 152 includes a base material made of a resin material and at least one kind of metal particles provided in the base material in this embodiment. A plurality of metal particles are in contact with each other in the base material, and electrically connect the terminals 122 and 123 to the wiring layers 113 and 114 . The resin material used for each of the wiring members 151 and 152 is the same in this embodiment, and examples thereof include thermosetting resins such as epoxy. In this embodiment, the metal particles used for the wiring members 151 and 152 are composed of a core made of a first metal material such as copper (Cu) and a second metal material such as gold (Au). and a coating layer for coating. However, the metal particles used for each wiring member may consist of only one type of metal material such as copper (Cu), silver (Ag), or gold (Au), or may consist of two or more types of metal particles. may

The first wiring member 151 has a first portion 151a and a second portion 151b.
The first portion 151a fills the first through hole 116a and the third through hole 119a. In this specification, "filling the inside of the through hole" does not mean filling the inside of the through hole completely, but means substantially filling the inside of the through hole. Voids may exist within the holes. The shape of the first portion 151a is a shape corresponding to the shapes of the first through hole 116a and the third through hole 119a, and is, for example, a substantially cylindrical shape.

The upper end of the first portion 151a is in contact with the lower end of the first terminal 122, and the first portion 151a is electrically connected via the first terminal 122 to the first electrode 124b. Thus, in this specification, two members are “electrically connected” means that the two members are directly connected and can conduct between the two members; and that two members are indirectly connected through another member that is electrically conductive, allowing electrical continuity between the two members.

The second portion 151b is a thin film portion positioned below the lower opening of the first through hole 116a in the first wiring member 151 . The second portion 151 b is continuous with the first portion 151 a , is arranged under the insulating layer 116 , and is in contact with the first wiring layer 113 . The second portion 151b covers part of the lower opening of the first through hole 116a and part of the lower surface 113d of the tip portion 113a of the first wiring layer 113, as shown in FIG. 4B. Specifically, the second portion 151b exposes a region of the lower opening of the first through hole 116a located on the second through hole 116b side in the X direction. However, the second portion may cover the entire lower opening of the first through hole.

Similarly, the second wiring member 152 has a third portion 152a and a fourth portion 152b, as shown in FIG.

The third portion 152a fills the inside of the second through hole 116b and the inside of the fourth through hole 119b. The shape of the third portion 152a is a shape corresponding to the shapes of the second through hole 116b and the fourth through hole 119b, and is, for example, a substantially cylindrical shape. The upper end of the third portion 152a is in contact with the lower end of the second terminal 123, and the third portion 152a is electrically connected via the second terminal 123 to the second electrode 124c.

The fourth portion 152b is a thin film-like portion located below the lower opening of the second through hole 116b in the second wiring member 152 . The fourth portion 152b continues to the third portion 152a, is arranged under the insulating layer 116, and is in contact with the second wiring layer 114. As shown in FIG. The fourth portion 152b covers part of the lower opening of the second through hole 116b and part of the lower surface 114d of the tip portion 114a of the second wiring layer 114, as shown in FIG. 4B. Specifically, the fourth portion 152b exposes a region of the lower opening of the second through hole 116b located on the first through hole 116a side in the X direction. As a result, contact between the second portion 151b and the fourth portion 152b can be suppressed. However, the fourth portion may cover the entire lower opening of the second through hole.

The lower surfaces of the first wiring member 151 and the second wiring member 152 are covered with a covering layer 153 as shown in FIG. Specifically, the covering layer 153 is arranged to cover the through hole 115 a of the second covering layer 115 . Thus, the covering layer 153 covers the exposed portions of the first wiring layer 113 , the second wiring layer 114 , the first wiring member 151 , and the second wiring member 152 from the second covering layer 115 . The covering layer 153 is made of an insulating material. Examples of insulating materials used for the coating layer 153 include resin materials such as polyimide (PI), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

Light guide member 130 has translucency to light emitted from light source 120 . As a material of the light guide member 130, for example, acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate (PET), thermoplastic resin such as polyester, thermosetting resin such as epoxy or silicone, glass, or the like can be used. .

The light guide member 130 is configured by a plate-like member. However, the light guide member may be composed of one or more light-transmitting layers instead of the plate-like member. When the light guide member is composed of a plurality of light-transmitting layers, the adjacent light-transmitting layers may be bonded together with a light-transmitting adhesive sheet. As the material of the light-transmitting adhesive sheet, it is preferable to use the same material as that of the light-transmitting layer so as to reduce the occurrence of an interface between the light-transmitting layer and the adhesive sheet.

Each light source arrangement portion 131 provided in the light guide member 130 is a through hole penetrating the light guide member 130 in the Z direction (vertical direction). The shape of the light source arrangement portion 131 in a top view is circular as shown in FIG. However, the shape of the light source arrangement portion when viewed from above is not limited to the above, and may be a polygon such as a square, a polygon with rounded corners, or an ellipse. Further, the light source placement portion may be a recess provided on the lower surface of the light guide member.

As shown in FIG. 3, a translucent member 133 is provided inside the light source arrangement portion 131 . In the present embodiment, the translucent member 133 has a two-layer structure, a first layer 133a provided in the gap between the light source 120 and the side surface of the light source arrangement portion 131, and a and a second layer 133b. However, the translucent member may have a single-layer structure, or may have a structure of three or more layers.

The first layer 133a seals the light source 120 in this embodiment. However, the first layer is provided only in the gap between the light source and the side surface of the light source arrangement portion, and does not need to seal the light source. The top surface of the first layer 133 a is located below the top surface of the light guide member 130 . The upper surface of the first layer 133a is concavely curved downward. However, the top surface of the first layer may be a flat surface parallel to the X direction and the Y direction.

The upper surface of the second layer 133b is a flat surface parallel to the X direction and the Y direction, and substantially flush with the upper surface of the light guide member 130. As shown in FIG. However, the upper surface of the second layer may be concavely curved downward, or may be positioned below the upper surface of the light guide member.

The first layer 133 a and the second layer 133 b have translucency with respect to light emitted from the light source 120 . The first layer 133a and the second layer 133b contain translucent material. Examples of translucent materials used for the first layer 133a and the second layer 133b include thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate (PET), and polyester, and thermosetting resins such as epoxy and silicone. etc. can be used. The second layer 133b may further include wavelength converting particles. However, the translucent member may not be provided in the light source arrangement portion, and the inside of the light source arrangement portion may be an air layer.

A second light adjusting member 134 is arranged on the translucent member 133 . As shown in FIG. 2, the second light adjustment member 134 is arranged so as to cover the light source 120 and partially expose the light source arrangement portion 131 when viewed from above. However, the second light adjustment member may be arranged so as to cover the entire area of the light source arrangement portion when viewed from above. The second light adjusting member 134 reflects part of the light emitted from the light source 120 and transmits another part of the light emitted from the light source 120 . The second light adjustment member 134 is, for example, resin containing a light reflective material. Specifically, as the second light adjustment member 134, a resin such as silicone containing titanium oxide or epoxy can be used as a light reflective material. The shape of the second light adjustment member 134 when viewed from above is quadrangular, as shown in FIG. However, the shape of the second light adjustment member in top view is not limited to the above, and may be circular, for example.

The dividing grooves 132 provided in the light guide member 130 are, as shown in FIG. 1, in a lattice shape extending in the X direction and the Y direction. However, the shape of the partitioning grooves is not limited to a lattice shape, and it is sufficient that each light emitting region can be optically partitioned to a practically sufficient extent. For example, the partition grooves may not be provided at the intersections of the lattice.

As shown in FIG. 3, the dividing groove 132 penetrates the light guide member 130 in the Z direction (vertical direction). The side surfaces of the dividing grooves 132 are parallel to the Z direction. However, the configuration of the dividing grooves is not limited to the above. For example, the side surfaces of the dividing grooves may be inclined or curved with respect to the Z direction. Further, the dividing groove may be a recess provided on the upper surface of the light guide member, or may be a recess provided on the lower surface of the light guide member, and may not reach the upper surface and the lower surface of the light guide member. It may be hollow. Also, a part of the dividing groove may be closed. Moreover, the dividing groove may be provided not only in the light guide member but also in the sheet laminate.

A partitioning member 135 is arranged in the partitioning groove 132 . The partitioning member 135 is, for example, a resin containing a light reflective material. Specifically, as the partition member 135, resin such as silicone containing titanium oxide or epoxy can be used as a light-reflecting material.

The partitioning member 135 is filled in the partitioning groove 132 , and the upper surface of the partitioning member 135 is flush with the upper surface of the light guide member 130 . However, the configuration of the partition member is not limited to the above. For example, the partitioning member may be formed in layers along the inner surface of the partitioning groove, or the upper portion of the partitioning member may protrude above the upper surface of the light guide member. Moreover, the partitioning member may not be provided in the partitioning groove, and the inside of the partitioning groove may be an air layer.

Next, a method for manufacturing the planar light source 100 according to this embodiment will be described.
FIG. 7 is a schematic cross-sectional view showing a method of manufacturing a planar light source.
FIG. 8A is a schematic cross-sectional view showing a method of manufacturing a planar light source.
FIG. 8B is a schematic cross-sectional view showing the manufacturing method of the planar light source.
FIG. 9 is a schematic cross-sectional view showing a method of manufacturing a planar light source.
FIG. 10A is a schematic cross-sectional view showing a method of manufacturing a planar light source.
FIG. 10B is a schematic bottom view showing the manufacturing method of the planar light source.
FIG. 11A is a schematic cross-sectional view showing the manufacturing method of the planar light source.
FIG. 11B is a schematic cross-sectional view showing the manufacturing method of the planar light source.

First, as shown in FIG. 7, a wiring board 110 is prepared. The wiring board 110 prepared here includes an insulating layer 116 provided with a first through hole 116a and a second through hole 116b separated from each other, and an insulating layer 116, which is disposed under the first through hole 116a and the second through hole 116b. It has a first wiring layer 113 and a second wiring layer 114 separated from the through hole 116b. A sheet laminate 119 is attached to the upper surface of the wiring board 110 . The sheet stack 119 is provided with a third through-hole 119a located directly above the first through-hole 116a and a fourth through-hole 119b located directly above the second through-hole 116b.

The first through-holes 116a and the third through-holes 119a can be formed at once by, for example, punching, drilling, laser irradiation, or the like after the sheet laminate 119 is placed on the wiring board 110 . Similarly, the second through-hole 116b and the fourth through-hole 119b can be formed at once by a similar method after the sheet laminate 119 is arranged on the wiring substrate 110, for example. However, the sheet laminate having the third and fourth through holes formed in advance may be arranged on the wiring substrate having the first through holes and the second through holes formed in advance.

Next, as shown in FIG. 8A, the light guide member 130 provided with the light source arrangement portion 131 on which the light source 120 is arranged is arranged on the wiring substrate 110 . The light guide member 130 is arranged such that the third through hole 119 a and the fourth through hole 119 b are exposed from the light source arrangement portion 131 . The light guide member 130 is attached to the sheet laminate 119 with the adhesive sheet 118b.
Next, as shown in FIG. 8B, dividing grooves 132 are formed in the light guide member 130 .

Next, as shown in FIG. 9, the light source 120 is arranged on the wiring substrate 110. Next, as shown in FIG. The light source 120 is arranged in the light source placement portion 131 so that the first terminal 122 covers the first through hole 116a and the second terminal 123 covers the second through hole 116b in top view. As a result, the first terminal 122 closes the opening of the third through hole 119a on the light source 120 side, and the second terminal 123 closes the opening of the fourth through hole 119b on the light source 120 side.

At this time, part of the lower surface of the first terminal 122 and part of the lower surface of the second terminal 123 are attached to the adhesive sheet 118 b of the sheet stack 119 . Thereby, the light source 120 can be temporarily fixed to the wiring board 110 .

Next, as shown in FIG. 10A , a translucent first adhesive is placed in the gap between the side surface of the light source arrangement portion 131 and the light source 120 so as to reinforce the temporary fixation of the light source 120 to the wiring substrate 110 by the adhesive sheet 118b. A resin member 133Fa is arranged. In the present embodiment, the translucent first resin member 133Fa is arranged such that the top surface thereof is located below the top surface of the light guide member 130 while sealing the light source 120 . However, the amount of the first resin member for reinforcing the temporary fixation of the light source may be such that the gap between the side surface of the light source placement portion and each terminal is closed and the light source is not sealed.

Next, in this embodiment, the first resin member 133Fa is cured. A cured product of the first resin member 133Fa corresponds to the first layer 133a of the translucent member 133 . However, the first resin member may be cured after disposing the conductive pastes 151F and 152F, which will be described later.

At this time, as shown in FIG. 10B, from the through hole 115a provided in the second covering layer 115 of the wiring substrate 110, the first through hole 116a, the second through hole 116b, the tip portion 113a of the first wiring layer 113 and the A portion of the intermediate portion 113b and a portion of the tip portion 114a and the intermediate portion 114b of the second wiring layer 114 are exposed to the outside.

Next, as shown in FIGS. 11A and 11B, a first wiring member 151 and a second wiring member 152 are formed.

Specifically, first, as shown in FIG. 11A, an intermediate body having a wiring board 110, a sheet laminate 119, a light source 120, and a light guide member 130 is placed in a direction from the wiring board 110 toward the light source 120. (Z direction) is arranged so as to approximately match the gravity direction G.

Next, the first conductive paste 151F is arranged so as to fill the insides of the first through holes 116a and the third through holes 119a and contact the insulating layer 116 and the first wiring layer 113 . Further, the second conductive paste 152F is arranged so as to fill the insides of the second through hole 116b and the fourth through hole 119b and contact the insulating layer 116 and the second wiring layer 114 .

The first conductive paste 151F arranged in this way continues to the first portion 151Fa filled in the first through hole 116a and the third through hole 119a, the first portion 151Fa, the insulating layer 116 and the first wiring layer. and a thin film-like second portion 151Fb in contact with 113 . The second portion 151Fb exposes part of the first portion 151Fa. As a result, voids existing in the first portion 151Fa can be easily released from the surface of the first portion 151Fa exposed from the second portion 151Fb until the first conductive paste 151F is cured. . As a result, voids included in the cured product of the first conductive paste 151F can be reduced.

Similarly, the second conductive paste 152F arranged in this way continues to the third portion 152Fa filled in the second through hole 116b and the fourth through hole 119b, the third portion 152Fa, and the insulating layer 116 and the third portion 152Fa. and a thin-film fourth portion 152Fb in contact with the second wiring layer 114 . The fourth portion 152Fb exposes part of the third portion 152Fa. As a result, voids existing in the third portion 152Fa can be easily released from the surface of the third portion 152Fa exposed from the fourth portion 152Fb until the second conductive paste 152F hardens. As a result, voids included in the cured product of the second conductive paste 152F can be reduced.

The conductive pastes 151F and 152F may be placed simultaneously or sequentially. Each conductive paste 151F, 152F includes an uncured resin material and one or more metal particles dispersed in the resin material. Thermosetting resin such as epoxy can be used as a resin material forming each of the conductive pastes 151F and 152F. Materials of the metal particles used for each of the conductive pastes 151F and 152F include, for example, a core made of a first metal material such as copper (Cu) and a second metal material such as gold (Au) in the present embodiment. and a covering layer made of a material and covering the core. However, the metal particles used for each wiring member may consist of only one type of metal material such as copper (Cu), silver (Ag), or gold (Au). Each of the conductive pastes 151F and 152F may further contain a volatile solvent.

As described above, the opening of the third through hole 119 a on the light source 120 side is blocked by the first terminal 122 , and the opening of the fourth through hole 119 b on the light source 120 side is blocked by the second terminal 123 . ing. Therefore, it is possible to prevent the conductive pastes 151F and 152F from leaking into the light source placement portion 131 of the light guide member 130 .

Furthermore, at this time, the gap between the side surface of the light source arrangement portion 131 and the light source 120 is filled with the cured material of the first resin member 133Fa (the first layer 133a of the translucent member 133). Therefore, when the through holes 119a and 119b corresponding to the terminals 122 and 123 are not completely blocked, the conductive pastes 151F and 152F leak into the light source arrangement portion 131 due to the cured material of the first resin member 133Fa. can be further suppressed.

Next, as shown in FIG. 11B, the first conductive paste 151F and the second conductive paste 152F are cured. When the resin material forming the conductive pastes 151F and 152F is a thermosetting resin, the conductive pastes 151F and 152F are cured by being heated. A cured product of the first conductive paste 151F corresponds to the first wiring member 151, and a cured product of the second conductive paste 152F corresponds to the second wiring member 152. FIG.

FIG. 12 is a schematic bottom view showing an enlarged central portion of the wiring board and end portions of the wiring board.
In FIG. 12, the through holes 116a and 116b at the end of the wiring board 110 before their positions change are indicated by two-dot chain lines.
Compared to the first wiring layer 113 and the second wiring layer 114, the insulating layer 116 is more likely to undergo deformation such as contraction or expansion due to environmental changes such as temperature or humidity. The deformation of the insulating layer 116 may occur, for example, depending on the environment such as temperature or humidity when the wiring board 110 is transported from the place where the wiring board 110 is manufactured to the place where the planar light source 100 is assembled. Further, the deformation of the insulating layer 116 may occur due to, for example, an increase in temperature when curing the first resin member 133Fa during manufacturing of the planar light source 100 . Due to the deformation of the insulating layer 116, the positions of the two through holes 116a and 116b with respect to the two wiring layers 113 and 114 may change as indicated by the arrows. The influence of such deformation of the insulating layer 116 differs depending on each position on the wiring board 110 in the X direction and the Y direction.

Specifically, for example, as shown in FIG. 12, in the central portion of the wiring board 110, the influence of the deformation of the insulating layer 116 is small, and the distance E1 between the first through hole 116a and the first wiring layer 113 in the X direction Also, the distance E2 in the X direction between the second through hole 116b and the second wiring layer 114 is approximately equal to the design value, for example, the distance E1 is approximately equal to the distance E2. On the other hand, the edge of the wiring board 110 is greatly affected by the deformation of the insulating layer 116, and the two through holes 116a and 116b are displaced in the X direction. As a result, the distance E1 in the X direction between the first through-hole 116a and the first wiring layer 113 and the distance E2 in the X-direction between the second through-hole 116b and the second wiring layer 114 are different from the design values. E1 is longer than distance E2.

In such a case, at each position on the wiring board 110, the first conductive paste 151F is such that the dimension F1 in the X direction of the portion located outside the first through hole 116a and the third through hole 119a corresponds to the distance E1. are arranged as follows. Similarly, at each position on the wiring board 110, the second conductive paste 152F is applied such that the dimension F2 in the X direction of the portions located outside the second through holes 116b and the fourth through holes 119b corresponds to the distance E2. placed. Therefore, for example, at the central portion of the wiring board 110, the dimension F1 of the first wiring member 151 and the dimension F2 of the second wiring member 152 are approximately equal. On the other hand, the dimension F1 of the first wiring member 151 is larger than the dimension F2 of the second wiring member 152 at the end of the wiring board 110 .

In this manner, the dimension F1 of each first conductive paste 151F is set according to the distance E1 in the X direction between the corresponding first wiring layer 113 and the first through hole 116a. Similarly, the dimension F2 of each second conductive paste 152F is set according to the distance E2 in the X direction between the corresponding second wiring layer 114 and the second through hole 116b. Thus, the first electrodes 124b and the first wiring layers 113 can be electrically connected one-to-one, and the second electrodes 124c and the second wiring layers 114 can be electrically connected one-to-one. That is, in the electrical connection structure between the two wiring layers 113, 114 and the two electrodes 124b, 124c, it is possible to suppress the occurrence of connection failures such as short circuits or open circuits. A short circuit is, for example, a state in which at least one of the two wiring layers 113 and 114 is connected to a wiring member other than the corresponding wiring member. Open means, for example, a state in which at least one of the two wiring layers 113 and 114 is not connected to any wiring member.

Moreover, due to the deformation of the insulating layer 116, as shown in FIG. 12, the two through holes 116a and 116b are displaced in a direction intersecting the arrangement direction (X direction) of the two through holes 116a and 116b, such as the Y direction. Sometimes. On the other hand, the two wiring layers 113 and 114 are arranged so as to sandwich the two through holes 116a and 116b when viewed from above. As a result, even if the two through holes 116a and 116b are displaced in any of the direction in which the two through holes 116a and 116b are arranged and the direction that intersects the direction in which the two through holes 116a and 116b are arranged, the first Separation of the through hole 116 a from the first wiring layer 113 and separation of the second through hole 116 b from the second wiring layer 114 can be suppressed. In addition, since the first wiring layer 113 and the second wiring layer 114 are not arranged between the first through hole 116a and the second through hole 116b when viewed from above, the first through hole 116a is located in the second wiring layer 114. The proximity and the proximity of the second through hole 116b to the first wiring layer 113 can be suppressed. As a result, in the electrical connection structure between the wiring layers 113 and 114 on the wiring substrate 110 and the electrodes 124b and 124c on the light source 120, it is possible to suppress the occurrence of connection failures such as short circuits or open circuits.

FIG. 13A is a schematic cross-sectional view showing a method of manufacturing a planar light source.
FIG. 13B is a schematic bottom view showing the manufacturing method of the planar light source.
Next, as shown in FIGS. 13A and 13B, a covering layer 153 is arranged to cover the first wiring member 151 and the second wiring member 152 .
Specifically, the covering layer 153 is arranged so as to cover the through hole 115 a provided in the second covering layer 115 . As a result, portions of the first wiring member 151 , the second wiring member 152 , the first wiring layer 113 , and the second wiring layer 114 exposed to the outside are covered with the covering layer 153 . A gap may exist between the covering layer 153 and the first wiring member 151 and between the covering layer 153 and the second wiring member 152 . Further, there may be no gap between the covering layer 153 and the first wiring member 151 and between the covering layer 153 and the second wiring member 152 .

14A and 14B are schematic cross-sectional views showing a method for manufacturing a planar light source.
FIG. 15A is a schematic cross-sectional view showing a method of manufacturing a planar light source.

Next, as shown in FIG. 14, in the light source arrangement portion 131, on the cured product of the first resin member (the first layer 133a of the translucent member 133), a second resin member having translucency is formed. 133Fb is deposited and cured. The second resin member 133Fb may contain wavelength conversion particles. A cured product of the second resin member 133Fb corresponds to the second layer 133b of the translucent member 133 . Thereby, the translucent member 133 composed of the first layer 133a and the second layer 133b is formed.

Next, as shown in FIG. 15A , the second light adjustment member 134 is arranged on the translucent member 133 and the partitioning member 135 is arranged in the partitioning groove 132 . A region of the lower surface of the first wiring member 151 located directly below the first through hole 116a is flat. In addition, the area of the lower surface of the second wiring member 152 that is located directly below the second through hole 116b is flat. As described above, the planar light source 100 is formed.

FIG. 15B is a schematic cross-sectional view showing another example of the shapes of the first wiring member, the second wiring member, and the covering layer.
Of the lower surface of the first wiring member 151, a region 151s located directly below the first through hole 116a may be recessed upward. In addition, of the lower surface of the second wiring member 152, a region 152s located directly below the second through hole 116b may be recessed upward. In the example shown in FIG. 15B, the lower surface of covering layer 153 is generally flat. However, in the lower surface of the coating layer 153, the area directly below the light source 120 may swell downward. In addition, on the lower surface of the covering layer 153 , the regions directly under the regions 151 s and 152 s may be recessed upward along the lower surfaces of the wiring members 151 and 152 .

For example, when the conductive pastes 151F and 152F are cured, diluents such as solvents contained in the conductive pastes 151F and 152F are removed, thereby forming the wiring members 151 and 152 having the shapes described above.

FIG. 15C is a schematic cross-sectional view showing another example of shapes of the first wiring member, the second wiring member, and the covering layer.
A region 151s of the lower surface of the first wiring member 151, which is positioned directly below the first through hole 116a, may swell downward. In addition, of the lower surface of the second wiring member 152, a region 152s located directly below the second through hole 116b may swell downward. In the example shown in FIG. 15C, the lower surface of covering layer 153 is generally flat. However, in the lower surface of the coating layer 153, the area directly below the light source 120 may swell downward. Further, on the lower surface of the covering layer 153 , regions located directly under the regions 151 s and 152 s may swell downward along the lower surfaces of the wiring members 151 and 152 .

For example, by arranging the conductive pastes 151F and 152F with a dispenser so that the portions of the conductive pastes 151F and 152F located directly above the through holes 116a and 116b swell upward, the above shape can be obtained. Wiring members 151 and 152 are formed. Further, for example, by printing the conductive pastes 151F and 152F a plurality of times so that the portions located directly above the through holes 116a and 116b swell upward, the wiring members 151 and 152 having the shapes described above are formed. It is formed.

When the regions 151s and 152s are flat or protrude downward, a force in the direction of pressing the wiring members 151 and 152 against the wiring board 110 is likely to act. Therefore, each wiring member 151 and 152 can be firmly fixed to the wiring board 110 .
Further, when the planar light source 100 is driven, the temperature of the planar light source 100 rises or falls depending on whether each light source 120 is lit or not. As a result, the wiring substrate 110, the sheet laminate 119, the light guide member 130, and the wiring members 151 and 152 that constitute the planar light source 100 may be deformed. At this time, since the coefficients of thermal expansion are different from each other, stress is applied to the wiring members 151 and 152, and cracks may occur. In this embodiment, as described above, by firmly fixing the wiring members 151 and 152 to the wiring substrate 110, the stress acting on the wiring members 151 and 152 can be alleviated. As a result, the occurrence of cracks in the wiring members 151 and 152 can be suppressed.

The material of the light reflective sheet 117 is preferably a material with a smaller thermal expansion coefficient than the light guide member 130 . Furthermore, it is preferable that the material of the light reflective sheet 117 is a material having a higher coefficient of thermal expansion than the wiring board 110 . Thereby, the difference in thermal expansion coefficient between the light guide member 130 and the wiring board 110 can be reduced. If the light guide member 130 is polycarbonate, the coefficient of thermal expansion is approximately 60 ppm/°C. If the main component of the light reflective sheet 117 is polyethylene terephthalate, the coefficient of thermal expansion is approximately 25 ppm/°C. If the wiring substrate 110 contains polyimide and copper, the coefficient of thermal expansion is approximately 17 ppm/°C.
As described above, the intensity of the planar light source 100 can be improved.

However, the manufacturing method of the planar light source is not limited to the above. For example, the first resin member for reinforcing temporary fixation of the light source in the light source arrangement portion may be arranged so as to fill the light source arrangement portion, and the step of arranging the second resin member may be omitted. Moreover, it is not necessary to arrange the first resin member for reinforcing the temporary fixation of the light source in the light source arrangement portion before arranging each conductive paste. Further, the step of forming the dividing grooves and the step of arranging the second light adjustment member and the dividing member may be performed before the step of forming the first wiring member and the second wiring member. Moreover, the step of arranging the light guide member may be performed after the step of arranging the light source.

Next, operation of the planar light source 100 according to this embodiment will be described.
The first wiring layer 113 is electrically connected to the first electrode 124b of the light source 120 via the first wiring member 151 and the first terminal 122, and the second wiring layer 114 is connected to the second wiring member 152 and the first terminal 122. It is electrically connected to the second electrode 124 c of the light source 120 via two terminals 123 . Therefore, by supplying power to the light source 120 from an external power supply through the first wiring layer 113 and the second wiring layer 114, the light source 120 can be lit.

The planar light source 100 can be applied, for example, as a backlight for a liquid crystal display. In the backlight in which the light emitting region R is divided for each of the plurality of light sources 120, local dimming can be performed with high accuracy by adjusting the output of each light source 120 individually.

Next, the effects of this embodiment will be described.
A planar light source 100 according to this embodiment includes a wiring substrate 110 , a light source 120 , a light guide member 130 , a first wiring member 151 and a second wiring member 152 . The wiring substrate 110 is disposed under an insulating layer 116 having a first through hole 116a and a second through hole 116b separated from each other, and the insulating layer 116, and is separated from the first through hole 116a and the second through hole 116b. and a first wiring layer 113 and a second wiring layer 114 . The light source 120 is disposed on the wiring board 110 and has a first electrode 124b and a second electrode 124c separated from each other. Light guide member 130 is arranged on wiring board 110 and surrounds light source 120 . The first wiring member 151 has a first portion 151a and a second portion 151b. The first portion 151a fills the first through hole 116a and is electrically connected to the first electrode 124b. The second portion 151 b is arranged under the insulating layer 116 , connected to the first portion 151 a and in contact with the first wiring layer 113 . The second wiring member 152 has a third portion 152a and a fourth portion 152b. The third portion 152a fills the inside of the second through hole 116b and is electrically connected to the second electrode 124c. The fourth portion 152 b is arranged under the insulating layer 116 , continues to the third portion 152 a, and contacts the second wiring layer 114 . When viewed from above, the first wiring layer 113 and the second wiring layer 114 are arranged so as to sandwich the first through hole 116a and the second through hole 116b.

In this way, the first through hole 116 a and the first wiring layer 113 that are separated from each other are electrically connected by the first wiring member 151 provided according to the positions of the first through hole 116 a and the first wiring layer 113 . The second through hole 116b and the second wiring layer 114, which are separated from each other, are electrically connected by a second wiring member 152 provided according to the positions of the second through hole 116b and the second wiring layer 114. there is Further, when viewed from above, the first wiring layer 113 and the second wiring layer 114 are arranged so as to sandwich the first through hole 116a and the second through hole 116b. That is, in top view, the first through hole 116a and the second through hole 116b are arranged between the first wiring layer 113 and the second wiring layer 114, while the first through hole 116a and the second through hole 116b The first wiring layer 113 and the second wiring layer 114 are not arranged between them. Therefore, even if the positions of the through holes 116a and 116b are misaligned with respect to the wiring layers 113 and 114 when forming the wiring members 151 and 152, the wiring layers 113 and 114 on the wiring substrate 110 and the electrodes 124b and 124c on the light source 120 are not aligned. In the electrical connection structure with, it is possible to suppress the occurrence of connection failure such as short circuit or open circuit.

Further, when viewed from above, the distance D1 between the center c1 of the first through hole 116a and the center c2 of the second through hole 116b is longer than the distance D2 between the center c3 of the first electrode 124b and the center c4 of the second electrode 124c. (D1>D2). Therefore, when the insulating layer 116 is deformed during manufacturing of the planar light source 100 or the like, the first wiring member 151 and the second wiring member 152 can be prevented from approaching or coming into contact with each other.

Further, of the side surface 113e of the first wiring layer 113, a region (first region 113s1) facing the first through hole 116a when viewed from above is concave in a direction away from the first through hole 116a, and is recessed in a direction away from the first through hole 116a. Of the side surface 114e of 114, a region (first region 114s1) facing the second through hole 116b in top view is concave in a direction away from the second through hole 116b.

Therefore, compared to the case where the regions 113s1 and 114s1 are linear in shape when viewed from above, as shown in FIG. The maximum value of the distance D3 and the maximum value of the distance D4 between each position of the first region 114s1 and the center c2 of the third portion 152a in top view can be reduced. As a result, the internal resistance of the first wiring member 151 and the second wiring member 152 can be reduced.

Further, the shape of the first through hole 116a and the shape of the second through hole 116b in top view are circular, and the side surface 113e of the first wiring layer 113 faces the first through hole 116a in top view. The shape of the region (first region 113s1) and the shape of the region (first region 114s1) of the side surface 114e of the second wiring layer 114 facing the second through hole 116b when viewed from the top are arc-shaped. be. In this way, by forming the first region 113s1 of the first wiring layer 113 into a shape corresponding to the shape of the first through hole 116a, each position of the first region 113s1 in top view and the center c1 of the first portion 151a The distance D3 can be kept substantially constant. The same applies to the second wiring layer 114 . As a result, the internal resistance of the first wiring member 151 and the second wiring member 152 can be reduced.

In addition, the light source 120 is arranged under the first electrode 124b, is in contact with the upper end of the first portion 151a, and has a first terminal 122 whose area in top view is equal to or larger than the area of the first electrode 124b, and the second electrode 124c. It further has a second terminal 123 disposed below, in contact with the upper end of the third portion 152a, and having an area as viewed from above that is equal to or larger than the area of the second electrode 124c. Therefore, according to the positions of the first terminal 122 and the second terminal 123, the first through hole 116a and the second through hole 116b that are separated from each other can be provided.

The first terminal 122 covers the first through hole 116a in top view, and the second terminal 123 covers the second through hole 116b in top view. Therefore, the contact areas between the terminals 122 and 123 and the wiring members 151 and 152 can be increased. Thereby, the connection between the terminals 122 and 123 and the wiring members 151 and 152 can be strengthened.

Moreover, the planar light source 100 further includes a covering layer 153 that covers the first wiring member 151 and the second wiring member 152 . Therefore, it is possible to prevent the wiring members 151 and 152 from being exposed to the outside.

Also, each of the first wiring member 151 and the second wiring member 152 has a base material made of a resin material and at least one kind of metal particles provided in the base material. Thus, each wiring member 151, 152 is made of conductive paste 151F, 152F. Therefore, even if the relative positions of the two through-holes 116a and 116b and the two wiring layers 113 and 114 change due to deformation of the insulating layer 116 during manufacturing of the planar light source 100, each conductive paste 151F , 152F, the first wiring member 151 and the second wiring member 152 can be easily formed according to the relative positions of the two through holes 116a and 116b and the two wiring layers 113 and 114. FIG.

In addition, the method for manufacturing the planar light source 100 according to the present embodiment includes the insulating layer 116 provided with the first through hole 116a and the second through hole 116b separated from each other, and the insulating layer 116 arranged below the first through hole 116, The first wiring layer 113 and the second wiring layer 114 are separated from the through hole 116a and the second through hole 116b. A step of preparing the wiring substrate 110 arranged so as to sandwich the second through hole 116b, and arranging the light guide member 130 provided with the light source arrangement portion 131 on which the light source 120 is arranged on the wiring substrate 110. a step of arranging the light source 120 on the wiring substrate 110; A first wiring member 151 and a second wiring member 151 that is separated from the first wiring member 151 , fills the second through hole 116 b , is in contact with the second wiring layer 114 , and is electrically connected to the second electrode 124 c of the light source 120 . and forming the wiring member 152 .

As described above, when the positions of the two through holes 116a and 116b with respect to the two wiring layers 113 and 114 are changed due to deformation of the insulating layer 116 during manufacturing of the planar light source 100, the two wiring layers 113 and 114 and Wiring members 151 and 152 are formed according to the positions of the two through holes 116a and 116b. Further, when viewed from above, the first wiring layer 113 and the second wiring layer 114 are arranged so as to sandwich the first through hole 116a and the second through hole 116b. Therefore, even if the positions of the through holes 116a and 116b are misaligned with respect to the wiring layers 113 and 114 when forming the wiring members 151 and 152, the wiring layers 113 and 114 on the wiring substrate 110 and the electrodes 124b and 124c on the light source 120 are not aligned. In the electrical connection structure with, it is possible to suppress the occurrence of connection failure such as short circuit or open circuit.

In the step of forming the first wiring member 151 and the second wiring member 152, the first conductive paste 151F is filled in the first through hole 116a and arranged so as to be in contact with the first wiring layer 113. filling the second through hole 116b with the second conductive paste 152F and placing it in contact with the second wiring layer 114; and curing the first conductive paste 151F and the second conductive paste 152F. and a step of causing In this way, the conductive pastes 151F and 152F are arranged according to the distances between the through holes 116a and 116b and the wiring layers 113 and 114 in the wiring substrate 110, respectively. Therefore, even if the relative positions of the two through holes 116a and 116b and the two wiring layers 113 and 114 change due to the deformation of the insulating layer 116, the two wiring layers 113 and 114 and the two electrodes 124b and 124c can be connected one-to-one. As a result, in the electrical connection structure between the wiring layers 113 and 114 on the wiring board 110 and the electrodes 124b and 124c on the light source 120, the occurrence of poor connection can be suppressed.

In addition, in the method of manufacturing the planar light source 100 according to the present embodiment, after the step of arranging the light guide member 130 and the light source 120 and before the step of forming the first wiring member 151 and the second wiring member 152, and placing a translucent resin member (first resin member 133Fa) in the gap between the light guide member 130 and the light source 120 within the light source placement portion 131 . Therefore, the resin member (first resin member 133Fa) can prevent the conductive pastes 151F and 152F from leaking into the light source arrangement portion 131. FIG.

In addition, the light source 120 further has a first terminal 122 arranged under the first electrode 124b and a second terminal 123 arranged under the second electrode 124c. The first terminal 122 is arranged to cover the first through hole 116a, and the second terminal 123 is arranged to cover the second through hole 116b. Therefore, it is possible to prevent the conductive pastes 151F and 152F from leaking from the openings of the through holes 116a and 116b on the light source 120 side.

<Second embodiment>
Next, a second embodiment will be described.
FIG. 16 is a schematic cross-sectional view showing an enlarged part of the planar light source according to this embodiment.
In the planar light source 200 according to the present embodiment, the shape of the peripheral portion 212a of the first through hole 216a and the peripheral portion 212b of the second through hole 216b of the insulating layer 216, and the shape of the third through hole 219a of the sheet laminate 219 The shapes of the peripheral portion 219c and the peripheral portion 219d of the fourth through hole 219b are different from those of the planar light source 100 according to the first embodiment. Details will be described below.
In addition, in the following description, in principle, only differences from the first embodiment will be described. Except for the matters described below, this embodiment is the same as the first embodiment. The same applies to other embodiments described later.

The wiring substrate 210 includes a base layer 211, a first covering layer 212 arranged on the base layer 211, a first wiring layer 213 and a second wiring layer 214 arranged below the base layer 211, and a base layer 211. and a second coating layer 215 positioned below 211 . The base layer 211 and the first covering layer 212 correspond to the insulating layer 216 .

The insulating layer 216 is positioned around the first peripheral portion 212a surrounding the first through hole 216a, the second peripheral portion 212b surrounding the second through hole 216b, and the first peripheral portion 212a and the second peripheral portion 212b, and a flat portion 212c generally parallel to the X and Y directions.

The upper and lower surfaces of the first peripheral portion 212a are curved downward. Similarly, the upper and lower surfaces of the second peripheral portion 212b are curved downward. By curving the upper surface of the first peripheral portion 212a and the upper surface of the second peripheral portion 212b downward, the conductive pastes 151F and 152F filled in the third through holes 219a and the fourth through holes 219b in a cross-sectional view , the connection area between the light emitting element and the conductive pastes 151F and 152F can be increased.

The sheet laminate 219 has a light reflective sheet 217 and two adhesive sheets 218a and 218b.

The sheet stack 219 is positioned around the first peripheral portion 219c surrounding the third through hole 219a, the second peripheral portion 219d surrounding the fourth through hole 219b, and the first peripheral portion 219c and the second peripheral portion 219d. , and a flat portion 219e generally parallel to the X and Y directions.

The upper and lower surfaces of the first peripheral portion 219c are curved downward as they approach the center of the third through hole 219a. Similarly, the upper and lower surfaces of the second peripheral portion 219d are curved downward toward the center of the fourth through hole 219b. In other words, the first peripheral portion 219 c and the second peripheral portion 219 d sink into the insulating layer 216 .

The first peripheral portion 219 c is separated from the first terminal 122 . Similarly, the second peripheral portion 219 d is separated from the second terminal 123 . The flat portion 219 e is in contact with the outer peripheral portion of the lower surface of the first terminal 122 and the outer peripheral portion of the lower surface of the second terminal 123 of the light source 120 . Therefore, a first gap S1 is provided between the first peripheral portion 219c and the first terminal 122, and a second gap S2 is provided between the second peripheral portion 219d and the second terminal 123. It is

A part of the first wiring member 251 is provided in the first gap S1, and fills the first gap S1, for example. Similarly, part of the second wiring member 252 is provided within the second gap S2, and fills the second gap S2, for example. Therefore, the contact area between the first wiring member 251 and the first terminal 122 and the contact area between the second wiring member 252 and the second terminal 123 can be increased. Thereby, the connection between the first wiring member 251 and the first terminal 122 and the connection between the second wiring member 252 and the second terminal 123 can be strengthened.

Next, a method for manufacturing the planar light source 200 according to this embodiment will be described.
17A and 17B are schematic cross-sectional views showing a method for manufacturing a planar light source.
18A and 18B are schematic cross-sectional views showing a method for manufacturing a planar light source.
19A and 19B are schematic cross-sectional views showing a method of manufacturing a planar light source.
FIG. 20 is a schematic cross-sectional view showing a method of manufacturing a planar light source.

First, as shown in FIG. 17, the sheet laminate 219 is arranged on the wiring board 210 .
Next, as shown in FIG. 18 , the drill 900 is moved from the upper surface side of the sheet laminate 219 toward the lower surface side of the insulating layer 216 to penetrate the sheet laminate 219 and the insulating layer 216 . As a result, the wiring substrate 210 is formed with a first through hole 216a and a second through hole 216b, and the sheet laminate 219 is formed with a third through hole 219a and a fourth through hole 219b. At this time, depending on the processing conditions or the hardness of the sheet laminate 119 and the insulating layer 216, the portion of the sheet laminate 219 in contact with the drill 900 may be pushed into the insulating layer 216 by the downward movement of the drill 900. be As a result, a first peripheral portion 219 c and a second peripheral portion 219 d that are embedded in the insulating layer 216 are formed in the sheet laminate 219 .

Next, the light guide member 130 provided with the light source arrangement portion 131 is arranged on the wiring board 210 and the sheet laminate 219 .
Next, dividing grooves 132 are formed in the light guide member 130 .
Next, the light source 120 is arranged inside the light source arrangement portion 131 . The light source 120 is arranged such that the outer peripheral portion of the first terminal 122 and the outer peripheral portion of the second terminal 123 are in contact with the flat portion 219 e of the sheet stack 219 .
Next, the first resin member 133Fa is placed inside the light source placement portion 131 and cured.

Next, as shown in FIG. 19, a first conductive paste 251F is filled in the first through hole 216a, the third through hole 219a, and the first gap S1, and the lower surface of the insulating layer 216 and the first gap S1 are filled with the first conductive paste 251F. It is arranged so as to be in contact with the wiring layer 213 . In addition, the second conductive paste 252F is arranged to fill the second through hole 216b, the fourth through hole 219b, and the second gap S2 and to be in contact with the lower surface of the insulating layer 216 and the second wiring layer 214. do.

Next, as shown in FIG. 20, the first conductive paste 251F and the second conductive paste 252F are cured. A cured product of the first conductive paste 251F corresponds to the first wiring member 251, and a cured product of the second conductive paste 252F corresponds to the second wiring member 252. FIG.

Since subsequent steps are the same as those of the manufacturing method of the planar light source 100 according to the first embodiment, description thereof is omitted.

<Third Embodiment>
Next, a planar light source according to the third embodiment will be described.
FIG. 21 is a schematic top view showing an enlarged view of part of the wiring board, part of the sheet laminate, and the light source of the planar light source according to this embodiment.
A planar light source 300 according to this embodiment differs from the planar light source 100 according to the first embodiment in the shapes of two electrodes 324 b and 324 c and two terminals 322 and 323 in the light source 320 . Details will be described below.

The light source 320 has a body portion 321 , a first terminal 322 and a second terminal 323 . The shape of the first electrode 324b in a top view is a rectangle having two long sides parallel to each other and two short sides parallel to each other. Each long side of the first electrode 324b is parallel to two of the four sides of the main body 321 that are parallel to each other when viewed from above. Each short side of the first electrode 324b is perpendicular to each long side of the first electrode 324b when viewed from above.

The shape of the second electrode 324c in top view is symmetrical with the first electrode 324b with respect to an axis L3 passing through the center of the main body 321 and parallel to the two long sides of the first electrode 324b.

The shape of the first terminal 322 in top view is a rectangle having two long sides parallel to each other and two short sides parallel to each other. When viewed from above, each long side of the first terminal 322 is substantially parallel to the two long sides of the first electrode 324b. Each short side of the first terminal 322 is perpendicular to each long side of the first terminal 322 when viewed from above.

The shape of the second terminal 323 when viewed from above is a shape obtained by cutting out a part of a rectangle that is symmetrical with the first terminal 322 with respect to the axis L3.

The area of the first terminal 322 in top view is larger than the area of the first electrode 324b, and the area of the second terminal 323 in top view is larger than the area of the second electrode 324c.

When viewed from above, the first terminal 322 covers the first through hole 116a, and the second terminal 323 covers the second through hole 116b.

As described above, the shape of the first electrode 324b and the shape of the second electrode 324c in top view may be rectangular. Also, the shape of the first terminal 322 and the shape of the second terminal 323 in top view may be rectangular.

<Fourth Embodiment>
Next, a fourth embodiment will be described.
FIG. 22 is a schematic cross-sectional view showing a planar light source according to this embodiment.
A planar light source 400 according to this embodiment differs from the planar light source 100 according to the first embodiment in the configuration of the first wiring member 451 and the second wiring member 452 . Details will be described below.

The first wiring member 451 fills the insides of the first through hole 116a and the third through hole 119a, connects the first portion 451a in contact with the first terminal 122, the first portion 451a, the lower surface of the insulating layer 116 and the third through hole 119a. and a thin film-like second portion 451 b in contact with one wiring layer 113 .

The second wiring member 452 fills the insides of the second through hole 116b and the fourth through hole 119b, is connected to the third portion 452a in contact with the second terminal 123, and extends from the lower surface of the insulating layer 116 and the third portion 452a. and a thin-film fourth portion 452 b in contact with the second wiring layer 114 .

The resin material forming the first portion 451a and the resin material forming the third portion 452a are the same, and the metal particles forming the first portion 451a and the metal particles forming the third portion 452a are the same. The resin material forming the second portion 451b and the resin material forming the fourth portion 452b are the same, and the metal particles forming the second portion 451b and the metal particles forming the fourth portion 452b are the same.

On the other hand, the resin material forming the first portion 451a is different from the resin material forming the second portion 451b. Also, the metal particles forming the first portion 451a are different from the metal particles forming the second portion 451b. However, at least one of the resin material and the metal particles may be the same. In this way, by using different materials for the first portion 451a and the second portion 451b of the first wiring member 451, the first portion 451a and the second portion 451b can be mechanically improved in terms of flexibility, etc. Properties such as properties or electrical properties such as conductivity may be different. The same applies to the second wiring member 452 as well.

Next, a method for manufacturing the planar light source 400 according to this embodiment will be described.
23A to 23C are schematic cross-sectional views showing a method for manufacturing a planar light source.
FIG. 24 is a schematic cross-sectional view showing a method of manufacturing a planar light source.
FIG. 25 is a schematic cross-sectional view showing a method of manufacturing a planar light source.

After the first resin member 133Fa is arranged in the light source arrangement portion 131 and cured, as shown in FIG. , the second through holes 116b and the fourth through holes 119b are filled with the second conductive paste 452Fa. Each of the conductive pastes 451Fa and 452Fa is made of the same material, and similar to the conductive pastes 151F and 152F in the first embodiment, an uncured resin material and one or more metals dispersed in the resin material. particles. Anticipating that the conductive pastes 451Fa and 452Fa will shrink when cured, the conductive pastes 451Fa and 452Fa may be arranged to protrude from the through holes 116a and 116b.

Next, as shown in FIG. 24, the first conductive paste 451Fa and the second conductive paste 452Fa are cured. A cured product of the first conductive paste 451Fa corresponds to the first portion 451a of the first wiring member 451, and a cured product of the second conductive paste 452Fa corresponds to the third portion 452a of the second wiring member 452.

Next, the third conductive paste 451Fb is placed in contact with the insulating layer 116, the first portion 451a, which is a cured product of the first conductive paste 451Fa, and the first wiring layer 113, and the fourth conductive paste 452Fb is applied. , the insulating layer 116, the third portion 452a which is the cured product of the second conductive paste 452Fa, and the second wiring layer 114. As shown in FIG.

Next, as shown in FIG. 25, the third conductive paste 451Fb and the fourth conductive paste 452Fb are cured. A cured product of the third conductive paste 451Fb corresponds to the second portion 451b of the first wiring member 451, and a cured product of the fourth conductive paste 452Fb corresponds to the fourth portion 452b of the second wiring member 452.

Since subsequent steps are the same as those of the manufacturing method of the planar light source 100 according to the first embodiment, description thereof is omitted.

As described above, in the method of manufacturing the planar light source 400 according to the present embodiment, the step of forming the first wiring member 451 and the second wiring member 452 includes applying the first conductive paste 451Fa into the first through hole 116a. filling the second through hole 116b with the second conductive paste 452Fa; curing the first conductive paste 451Fa and the second conductive paste 452Fa; Arranged so as to be in contact with the cured first conductive paste 451Fa and the first wiring layer 113, and arrange the fourth conductive paste 452Fb so as to be in contact with the cured second conductive paste 452Fa and the second wiring layer 114. and curing the third conductive paste 451Fb and the fourth conductive paste 452Fb. Thus, the first portion 451a and the second portion 451b of the first wiring member 451 do not have to be formed at the same time. Also, the third portion 452a and the fourth portion 452b of the second wiring member 452 may not be formed at the same time. According to such a method, the materials of the first conductive paste 451Fa and the second conductive paste 452Fa can be made different from the materials of the third conductive paste 451Fb and the fourth conductive paste 452Fb.

Note that the third conductive paste and the fourth conductive paste may be arranged before curing the first conductive paste and the second conductive paste. That is, the step of forming the first wiring member and the second wiring member includes filling the first conductive paste into the first through hole and filling the second conductive paste into the second through hole; placing a conductive paste in contact with the first conductive paste and the first wiring layer, and placing a fourth conductive paste in contact with the second conductive paste and the second wiring layer; curing the conductive paste, the second conductive paste, the third conductive paste, and the fourth conductive paste.

<Fifth Embodiment>
Next, a fifth embodiment will be described.
26A and 26B are schematic cross-sectional views showing a method for manufacturing a planar light source according to the fifth embodiment.
In the method for manufacturing the planar light source according to the present embodiment, the shape of the cured product of the first resin member 533Fa that reinforces the temporary fixing of the light source 120 to the wiring board 110 is changed from that of the planar light source 100 according to the first embodiment. It differs from the manufacturing method. Details will be described below.

After arranging the sheet laminate 119, the light guide member 130, and the light source 120 on the wiring substrate 110, the side surface of the light source arrangement portion 131 and the light source arrangement portion 131 are arranged so as to reinforce the temporary fixing of the light source 120 to the wiring substrate 110 by the adhesive sheet 118b. A translucent first resin member 533Fa is placed in the gap with the light source 120 and cured.

In the present embodiment, the translucent first resin member 533Fa is arranged such that the top surface thereof is located below the top surface of the light guide member 130 while sealing the light source 120 . The cured product of the first resin member 533Fa corresponds to the first layer of the translucent member. In addition, on the upper surface of the first resin member 533Fa, a region 533Fc positioned between the side surface of the light source placement portion 131 and the light source 120 is recessed downward. A portion of the region 533Fc is positioned below the top surface of the light source 120 .

Next, conductive pastes 151F and 152F are arranged in the same manner as in the first embodiment. At this time, the gap between the side surface of the light source arrangement portion 131 and the light source 120 is closed by the first resin member 533Fa. Therefore, it is possible to prevent the conductive pastes 151F and 152F from leaking into the light source placement portion 131 . Since the subsequent procedure is the same as that of the planar light source 100 according to the first embodiment, the explanation thereof is omitted.

<Sixth Embodiment>
Next, a sixth embodiment will be described.
FIG. 27 is a schematic cross-sectional view showing a planar light source according to this embodiment.
A planar light source 600 according to this embodiment differs from the planar light source 100 according to the first embodiment in the configurations of a light source 620 and a light guide member 630 .

The light source 620 has a light emitting element 621 , a wavelength conversion member 622 , a translucent member 623 and a coating layer 624 .

The light-emitting element 621 has a light-emitting portion 621a, and a first electrode 621b and a second electrode 621c arranged under the light-emitting portion 621a and separated from each other. A wavelength conversion member 622 is provided on the light emitting element 621 .

The translucent member 623 is provided below the wavelength converting member 622 and around the light emitting section 621a. The covering layer 624 is provided around the translucent member 623 and under the light emitting portion 621a. The outer surface of the translucent member 623 may be an inclined surface.

The light guide member 630 is provided with a light source arrangement portion 631 in which the light source 620 is arranged. The light source arrangement portion 631 is a concave portion provided on the lower surface of the light guide member 630 in this embodiment.

Further, the light guide member 630 is provided with partition grooves 632 so as to surround each light source 620 . The dividing grooves 632 are recesses provided on the lower surface of the light guide member 630 in this embodiment.

A partitioning member 633 is provided on the lower surface of the light guide member 630 and in the partitioning groove 632 . The partitioning member 633 is provided with a through hole 633 a that communicates with the light source arrangement portion 631 of the light guide member 630 . A translucent member 634 is provided in the light source arrangement portion 631 and the through hole 633a. The partition member 633 is attached to the wiring board 110 with an adhesive sheet 618 .

The adhesive sheet 618 is provided with a third through hole 618a and a fourth through hole 618b. The third through hole 618a is located directly above the first through hole 116a. The fourth through hole 618b is located directly above the second through hole 116b.

A plurality of concave portions 635 are provided on the upper surface of the light guide member 630 . Each recess 635 is positioned directly above each light source 620 . A light adjustment member 636 is provided in each recess 635 .

Next, a method for manufacturing the planar light source 600 according to this embodiment will be described.
FIG. 28 is a schematic cross-sectional view showing a method of manufacturing a planar light source.
FIG. 29 is a schematic cross-sectional view showing a method of manufacturing a planar light source.
First, as shown in FIG. 28, a wiring board 110 is prepared.

Next, the light guide member 630 and the light source 620 are arranged on the wiring board 110 . In this embodiment, the light source 620 , the light guide member 630 , the partition member 633 , the translucent member 634 , and the light adjustment member 636 are previously integrated as a light emitting module before being arranged on the wiring board 110 . , is attached to the wiring board 110 with an adhesive sheet 618 . However, the light adjustment member 636 may be provided on the light guide member 630 after the light source 620 and the light guide member 630 are arranged on the wiring board 110 .

Next, as shown in FIG. 29, a first conductive paste 151F is placed so as to fill the first through hole 116a and the third through hole 618a and contact the insulating layer 116 and the first wiring layer 113. do. Further, the second conductive paste 152F is arranged so as to fill the second through holes 116b and the fourth through holes 618b and contact the insulating layer 116 and the second wiring layer 114 .

Since the subsequent steps are the same as those of the manufacturing method of the planar light source 100 according to the first embodiment, description thereof will be omitted.

As described above, the light source arrangement portion 631 may be a concave portion provided on the lower surface of the light guide member 630 . Further, when manufacturing the planar light source 600 , the light source 620 and the light guide member 630 may be integrated and then arranged on the wiring board 110 .

Although the light source 620 does not have the first terminal and the second terminal in this embodiment, the light source 620 may further have the first terminal and the second terminal.

Also, in the present embodiment, the case where the first through hole 116a and the second through hole 116b of the wiring board 110 are positioned below the light source 620 has been described, but the present invention is not limited to this. That is, the first through hole 116a and the second through hole 116b of the wiring board 110 do not need to be positioned below the light source 620. FIG. In this case, a conductive layer electrically connected to the electrodes 621 a and 621 b of the light source is provided on the upper surface of the wiring substrate 110 or the lower surface of the partitioning member 633 , and the conductive layer is provided on the first wiring member 151 and the second wiring member 152 . may be connected.

<Seventh Embodiment>
Next, a seventh embodiment will be described.
FIG. 30 is a schematic bottom view showing an enlarged part of the light source and the wiring board in the planar light source according to this embodiment.
31A is a schematic cross-sectional view taken along line XXXI-XXXI of FIG. 30. FIG.
A planar light source 700 according to this embodiment differs from the planar light source 100 according to the first embodiment in the configuration of a wiring board 710 .

The wiring substrate 710 includes a base layer 711, a first covering layer 712 arranged on the base layer 711, and a first wiring layer 713 arranged below the base layer 711, as shown in FIGS. 30 and 31A. and a second wiring layer 714 and a second covering layer 715 provided under the base layer 711 . The base layer 711 and the first covering layer 712 correspond to the insulating layer 716 .

The insulating layer 716 is provided with a first through hole 716a and a second through hole 716b that are separated from each other. Each through hole 716a, 716b penetrates the insulating layer 716 in the Z direction.

As shown in FIG. 30, the first wiring layer 713 and the second wiring layer 714 are not arranged so as to sandwich the first through hole 716a and the second through hole 716b, and the first through hole 716a and the second through hole 716b 716a and the second through hole 716b. Each wiring layer 713, 714 extends in the Y direction in this embodiment. The distance D5 between the tip portion 713a of the first wiring layer 713 and the tip portion 714a of the second wiring layer 714 is longer than the distance D6 between the first through hole 716a and the second through hole 716b. However, the size relationship between the distance between the tip of the first wiring layer and the tip of the second wiring layer and the distance between the first through hole and the second through hole is not limited to the above.

The second covering layer 715 covers the lower surface of the insulating layer 716 around the first through holes 716a and the second through holes 716b so that the first through holes 716a and the second through holes 716b are exposed. . Also, the second covering layer 715 partially exposes the first wiring layer 713 and the second wiring layer 714 .

Specifically, the second covering layer 715 is provided with a first opening 715a exposing the first through hole 716a and a second opening 715b exposing the second through hole 716b. The first opening 715a is positioned directly below the first through hole 716a. The second opening 715b is positioned directly below the second through hole 716b. The shape of the first opening 715a and the second opening 715b in top view is substantially the same as the first through hole 716a and the second through hole 716b, for example, and is polygonal such as circular or triangular. However, the shapes of the first opening and the second opening when viewed from above are not limited to the above. The opening diameter of the first opening 715a matches the opening diameter of the first through hole 716a, as shown in FIGS. 30 and 31A. Similarly, the opening diameter of the second opening 715b matches the opening diameter of the second through hole 716b, as shown in FIGS. 30 and 31A.

Further, the second cover layer 715 is provided with a third opening 715c exposing the tip portion 713a of the first wiring layer 713 and a fourth opening 715d exposing the tip portion 713b of the second wiring layer 714. there is The shape of each of the openings 715c and 715d in top view is circular. However, the shape of the third opening and the fourth opening when viewed from above may be a polygon such as a semicircle or a rectangle. Moreover, one opening may expose a part of the first wiring layer and the second wiring layer.

The third opening 715c and the fourth opening 715d are separated from the first opening 715a and the second opening 715b. A distance D7 between the third opening 715c and the fourth opening 715d is longer than a distance D6 between the first through hole 716a and the second through hole 716b. However, the size relationship between the distance between the third opening and the fourth opening and the distance between the first through hole and the second through hole is not limited to the above.

As shown in FIG. 31A, the first wiring member 751 passes through the first through hole 716a, the third through hole 119a, the first portion 751a filling the first opening 715a, and the lower surface of the second coating layer 715. and a second portion 751 b in contact with a portion of the first wiring layer 713 exposed from the second covering layer 715 .

The first portion 751a is in contact with the first terminal 122 and electrically connected to the first electrode 124b via the first terminal 122 . The second portion 751b is in contact with the tip portion 713a of the first wiring layer 713 in this embodiment.

The second wiring member 752 extends through the second wiring layer 714 via a third portion 752a filling the insides of the second through holes 716b, the fourth through holes 119b, and the second openings 715b, and the lower surface of the second covering layer 715. and a fourth portion 752b in contact with the portion exposed from the second covering layer 715 at the .

The third portion 752a is in contact with the second terminal 123 and electrically connected to the second electrode 124c via the second terminal 123 . The fourth portion 752b is in contact with the tip portion 714a of the second wiring layer 714 in this embodiment.

In addition, the planar light source 700 further includes a covering layer that covers portions of the first wiring member 751, the second wiring member 752, the first wiring layer 713, and the second wiring layer 714 exposed from the second covering layer 715. may be

In this embodiment, as shown in FIG. 30, the third opening 715c and the fourth opening 715d are located on the -Y direction side of the first opening 715a and the second opening 715b, but the present invention is not limited to this. For example, the third opening 715c and the fourth opening 715d may be located on the +Y direction side from the first opening 715a and the second opening 715b. Further, the third opening 715c is located on the -Y direction side from the first opening 715a and the second opening 715b, and the fourth opening 715d is located on the +Y direction side from the first opening 715a and the second opening 715b. may On the contrary, the fourth opening 715d is located on the -Y direction side from the first opening 715a and the second opening 715b, and the third opening 715c is located on the +Y direction side from the first opening 715a and the second opening 715b. good too. Also, the third opening 715c and the fourth opening 715d may be arranged on a virtual line passing through the first opening 715a and the second opening 715b so as to sandwich the first opening 715a and the second opening 715b.

FIG. 31B is a schematic bottom view showing another example of the light source and wiring board;
As shown in FIG. 31B, the light source 120 may be arranged such that the two electrodes 124b and 124c are arranged in a direction intersecting the X direction and the Y direction. In this case, the third opening 715c is located on the +Y direction side of the first opening 715a and the second opening 715b, and the fourth opening 715d is located on the -Y direction side of the first opening 715a and the second opening 715b. good too. The third opening may be located on the -Y direction side of the first and second openings, and the fourth opening may be located on the +Y direction side of the first and second openings.

Next, a method for manufacturing the planar light source 700 according to this embodiment will be described.
FIG. 32A is a schematic cross-sectional view showing a method of manufacturing a planar light source;
FIG. 32B is a schematic cross-sectional view showing the manufacturing method of the planar light source.

First, the wiring board 710 is prepared. In the wiring board 710 prepared here, the second covering layer 715 is formed in the lower surface of the insulating layer 716 so that the first through holes 716a and the second through holes 716b are exposed so that the first through holes 716a and the second through holes 716b are exposed. , and part of the first wiring layer 713 and the second wiring layer 714 are exposed.

Next, the light guide member 130 and the light source 120 are arranged on the wiring board 710 in the same manner as in the first embodiment.

Next, a first wiring member 751 and a second wiring member 752 are formed. Specifically, as shown in FIG. 32A, the first conductive paste 751F is filled in the first through hole 716a, the third through hole 119a, and the first opening 715a, and the second coating layer 715 is filled with the first conductive paste 751F. It is arranged so as to be in contact with the first wiring layer 713 via the lower surface. Similarly, as shown in FIG. 32B, the second conductive paste 752F is filled in the second through hole 716b, the fourth through hole 119b, and the second opening 715b, and the lower surface of the second coating layer 715 is It is arranged so as to be in contact with the second wiring layer 714 via the second wiring layer 714 . The first conductive paste 751F and the second conductive paste 752F may be placed simultaneously or separately.

The conductive pastes 751F and 752F are arranged on the wiring board 710 by printing with a squeegee or a pressing machine, for example. As described above, the second covering layer 715 is provided on the lower surface of the insulating layer 716 around the first through hole 716a. Therefore, it is easy to press the first conductive paste 751F into the first through-hole 716a, the third through-hole 119a, and the first opening 715a with a pressing machine M such as a printing machine. The same applies to the second conductive paste 752F. The press M can have rollers inside. By rotating this roller, the conductive paste filled in the pressing machine M is supplied in a pressed state. This makes it easier to push the first conductive paste 751F into the first through hole 716a, the third through hole 119a, and the first opening 715a. The same applies to the second conductive paste 752F.

Since the subsequent steps are the same as those of the manufacturing method of the planar light source 100 according to the first embodiment, description thereof will be omitted. A cured product of the first conductive paste 751</b>F corresponds to the first wiring member 751 . A cured product of the second conductive paste 752</b>F corresponds to the second wiring member 752 . However, after placing the first conductive paste that becomes the first portion 751a and the second conductive paste that becomes the third portion 752a when cured, the third conductive paste and the fourth portion 752b that become the second portion 751b when cured are placed. You may arrange|position the 4th conductive paste which becomes.

The first through-hole 716a, the third through-hole 719a, and the first opening 715a may be completely aligned and overlapped, or may be overlapped while being offset from each other. Similarly, the second through-hole 716b, the fourth through-hole 719b, and the second opening 715b may be completely coincident and overlapped, or they may be offset from each other.

As described above, in the planar light source 700 according to the present embodiment, the wiring substrate 710 has the first through holes 716a formed on the lower surface of the insulating layer 716 so that the first through holes 716a and the second through holes 716b are exposed. and a second covering layer 715 covering the periphery of the second through hole 716 b and exposing a part of the first wiring layer 713 and the second wiring layer 714 . The second portion 751b of the first wiring member 751 continues to the first portion 751a and contacts the exposed portion of the first wiring layer 713 from the second covering layer 715 via the lower surface of the second covering layer 715. ing. Further, the fourth portion 762b of the second wiring member 752 continues to the third portion 752a and is in contact with the portion of the second wiring layer 714 exposed from the second covering layer 715 via the lower surface of the second covering layer 715. ing.

Thus, the second covering layer 715 is provided on the lower surface of the insulating layer 716 around the first through holes 716a and the second through holes 716b. When the first opening 715a and the second opening 715b of the second coating layer 715 have the same opening diameter as the first through hole and the second through hole, the force pushing the conductive paste when printing the conductive paste is increased, the first portion 751a of the first wiring member 751 can be easily arranged to the depth of the first through hole 716a (that is, the light source side of the first through hole). Similarly, it is easy to arrange the third portion 752a of the second wiring member 752 to the depth of the second through hole 716b (that is, the light source side of the second through hole). Therefore, in the electrical connection structure between the wiring layers 713 and 714 on the wiring board 710 and the electrodes 124b and 124c on the light source 120, the occurrence of poor connection can be suppressed.

In addition, the second covering layer 715 has a third opening 715c that is separated from the first through hole 716a and exposes a part of the first wiring layer 713, and a third opening 715c that is separated from the second through hole 716b and has a second wiring layer 714. A fourth opening 715d that exposes a part of is provided. That is, the second covering layer 715 exposes the first wiring layer 713 and the second wiring layer 714 separately. Therefore, electrical connection between the first wiring layer 713 and the second wiring layer 714 can be suppressed.

Also, the distance D7 between the third opening 715c and the fourth opening 715d is longer than the distance D6 between the first through hole 716a and the second through hole 716b. Therefore, short-circuiting between the first wiring layer 713 and the second wiring layer 714 can be suppressed.

<Eighth embodiment>
Next, an eighth embodiment will be described.
FIG. 33 is a schematic bottom view showing an enlarged part of the wiring board in the planar light source according to this embodiment.
The planar light source 800 according to this embodiment differs from the planar light source 700 according to the seventh embodiment in the configuration of the first wiring layer 813, the second wiring layer 814, and the second covering layer 815 in the wiring substrate 810. do.
In addition, in the following description, in principle, only differences from the seventh embodiment will be described. Except for the matters described below, this embodiment is the same as the seventh embodiment.

The first wiring layer 813 and the second wiring layer 814 are arranged so as to sandwich the first through hole 716a and the second through hole 716b. The shapes of the first wiring layer 813 and the second wiring layer 814 are substantially the same as the shapes of the first wiring layer 113 and the second wiring layer 114 in the first embodiment.

In the second covering layer 815, the third opening 815a and the fourth opening 815b are arranged so as to sandwich the first opening 715a and the second opening 715b. The shape of the third opening 815a and the fourth opening 815b in top view is semicircular. However, the shapes of the third opening and the fourth opening are not limited to the above.

In this manner, the third opening 815a and the fourth opening 815b may be arranged so as to sandwich the first opening 715a and the second opening 715b. As a result, even if the positions of the through holes 716a and 716b with respect to the wiring layers 813 and 814 are misaligned when forming the wiring members 751 and 752, the wiring layers 813 and 814 in the wiring substrate 810 and the electrodes 124b and In the electrical connection structure with 124c, the occurrence of poor connection can be suppressed.

<Ninth Embodiment>
Next, a ninth embodiment will be described.
FIG. 34 is a schematic top view showing a planar light source according to this embodiment.
A planar light source 1000 according to this embodiment includes a wiring board 910 and a light emitting module 920 arranged on the wiring board 910 .

In the present embodiment, the wiring board 910 includes a body portion 910a having a substantially rectangular shape when viewed from above, and a plurality of projecting portions 910b that are connected to the ends of the body portion 910a in the Y direction and project in the Y direction. . A light-emitting module 920 is arranged on the body portion 910a. However, the shape of the wiring board is not limited to the above shape, and may be a polygon or a quadrangle other than a rectangle (for example, a substantially trapezoid). Also, the number of projecting portions 910b provided on the wiring board 910 is not limited to four as shown in FIG. 34, and may be less than four or more than four.

FIG. 35 is a schematic top view showing an enlarged area surrounded by broken lines XXXV in FIG. 34 in the light-emitting module according to this embodiment.
36 is a schematic cross-sectional view taken along line XXXVI-XXXVI of FIG. 35. FIG.
As in the sixth embodiment, the light emitting module 920 includes a plurality of light sources 620, a light guide member 630 provided with a plurality of recesses 635, a partition member 633, a translucent member 634, and a light adjustment member 636. and have The light-emitting module 920 further includes a plurality of wiring layers 921 arranged under the partition member 633 and a covering layer 922 provided under the plurality of wiring layers 921 .

A plurality of light sources 620 are arranged in the X direction and the Y direction, as shown in FIG.
The same material as the wiring layers 113 and 114 in the first embodiment can be used for the wiring layer 921 . Each wiring layer 921 is electrically connected to one of the plurality of light sources 620, as shown in FIG.
An insulating resin can be used for the coating layer 922 . The covering layer 922 covers at least part of each wiring layer 921 .

The wiring patterns of the plurality of wiring layers 921 in the light emitting module 920 will be described below.
FIG. 37 is a schematic top view of the light-emitting module according to the present embodiment, enlarging the region surrounded by XXXV in FIG. 34 and showing the wiring pattern through the wiring pattern.
In addition, in FIG. 37, the area in which the wiring layer 921 is provided is indicated by dots for easy understanding of the explanation. Also, in FIG. 37, the concave portion 635 and the light adjustment member 636 provided in the light guide member 630 are omitted in order to make the wiring pattern easier to understand.
The plurality of wiring layers 921 form a wiring layer group 921S every five. Each wiring layer group 921S connects four light sources 620 in series in this embodiment. These four light sources 620 are arranged in a matrix with two columns in the X direction and two rows in the Y direction. That is, each wiring layer group 921S corresponds to a current path connecting four light sources 620 in series. However, the number of light sources connected to each wiring layer group is not limited to the above number.

A plurality of wiring layer groups 921S are arranged in the X direction and the Y direction. A plurality of wiring layer groups 921S arranged in the X direction are hereinafter referred to as "rows MT". That is, in the present embodiment, multiple rows MT are arranged in the Y direction. Hereinafter, as shown in FIG. 34, among the plurality of rows MT, the row MT closest to the projecting portion 910b of the wiring board 910 is also referred to as "first row MT1". Further, among the plurality of rows MT, a row MT adjacent to the first row MT1 in the Y direction is also referred to as a “second row MT2”. Further, among the plurality of rows MT, the row MT farthest from the projecting portion 910b of the wiring board 910 is also referred to as the “last row MTn”.

The wiring pattern of the wiring layer group 921S belonging to the first row MT1 will be described below.
Hereinafter, as shown in FIG. 37, the five wiring layers 921 constituting the wiring layer group 921S belonging to the first row MT1 are designated as "first wiring layer 921a,""second wiring layer 921b," and "third wiring layer."921c","fourth wiring layer 921d", and "fifth wiring layer 921e". One light source 620 of the four light sources 620 connected in series by the wiring layer group 921S is also referred to as a "first light source 620a", and the light source 620 adjacent to the first light source 620a in the X direction is referred to as a "second light source 620b". , the light source 620 that is adjacent to the first light source 620a in the Y direction is also referred to as a “third light source 620c,” and is adjacent to the second light source 620b in the Y direction and to the third light source 620c in the X direction. 620 is also referred to as "fourth light source 620d".

The first wiring layer 921a has a pad portion P1 at least partially exposed from an opening 922a of the covering layer 922, one end connected to the pad portion P1, and the other end connected to the first electrode 621b of the first light source 620.
(see FIG. 36) and an extension P2 electrically connected to the . The shape of the pad part P1 is substantially rectangular in this embodiment. However, the shape of the pad portion may be polygonal, circular, elliptical, or the like other than square. The same applies to the shapes of pad portions P3, P5, and P7, which will be described later. The extending portion P2 is covered with a covering layer 922 .

The second wiring layer 921b has one end electrically connected to the second electrode 621c (see FIG. 36) of the first light source 620a and the other end electrically connected to the first electrode 621b of the second light source 620b. ing.

The third wiring layer 921c has one end electrically connected to the second electrode 621c of the second light source 620b and the other end electrically connected to the first electrode 621b of the third light source 620c.

The fourth wiring layer 921d has one end electrically connected to the second electrode 621c of the third light source 620c and the other end electrically connected to the first electrode 621b of the fourth light source 620d.

The second wiring layer 921 b, the third wiring layer 921 c, and the fourth wiring layer 921 d are covered with a covering layer 922 .

The fifth wiring layer 921e has one end connected to the pad portion P3 at least partially exposed from the opening 922b of the covering layer 922 and the pad portion P3, and the other end electrically connected to the second electrode 621c of the fourth light source 620d. and an extension P4. The pad portion P3 is adjacent to the pad portion P1 of the first wiring layer 921a in the X direction. The extending portion P4 is covered with a covering layer 922 .

The pad portions P1 and P3 are further apart from the projecting portion 910b than the four light sources 620a, 620b, 620c and 620d in the Y direction. In addition, the pad portions P1 and P3 have four light sources 620 to which the wiring layer group 921S belonging to the first row MT1 are connected in series and four light sources 620 to which the wiring layer group 921S belonging to the second row MT2 are connected in series in a bottom view. between the two light sources 620 and . Therefore, the pad portions P1 and P3 of the wiring layer group 921S belonging to the first row MT1 can be separated from the outer edge of the main body portion 121 of the wiring substrate on the side of the projecting portion 910b in the Y direction. In this case, the distance from the pad portions P1 and P2 of the wiring layer group 921S belonging to the first row MT1 according to the present embodiment to the outer edge of the main body portion 121 of the wiring substrate on the side of the projecting portion 910b in the Y direction is When the pad portion P3 is positioned between the light source 620b and the light source 620d and the pad portion P1 and P2 are positioned between the light source 620a and the light source 620c and the pad portion P3 is positioned between the light source 620b and the light source 620d, the projection portion 910b side of the body portion 121 of the wiring substrate in the Y direction It can be greater than the distance to the outer edge.

Next, the wiring pattern of the wiring layer group 921S belonging to the second row MT2 will be described.
The wiring layer group 921S belonging to the second row MT2 includes, similarly to the wiring layer group 921S belonging to the first row MT1, a first wiring layer 921f, a second wiring layer 921g, a third wiring layer 921h, a fourth wiring layer 921i, and a fifth wiring layer 921j. Similarly to the wiring layer group 921S belonging to the first row MT1, the wiring layer group 921S belonging to the second row MT2 includes the first light source 620e, the second light source 620f, the third light source 620g, and the fourth light source 620h connected in series. connected to. Only the difference between the second row MT2 and the first row MT1 will be described below.

The pad portion P5 of the first wiring layer 921f is positioned between the first light source 620e and the third light source 620g in bottom view. Also, the pad portion P7 of the fifth wiring layer 921j is located between the second light source 620f and the fourth light source 620h in bottom view. Further, the pad portion P5 of the first wiring layer 921f and the pad portion P7 of the fifth wiring layer 921j are arranged so as to sandwich the third wiring layer 921h in the X direction when viewed from below.

Therefore, compared to the case where the wiring pattern of the wiring layer group 921S belonging to the first row MT1 is the same as the wiring pattern of the wiring layer group 921S belonging to the second row MT2, the wiring layer group 921S belonging to the first row MT1 and the pad portion P5 of the wiring layer group 921S belonging to the second row MT2 can be shortened.

Further, the extending portion P6 of the first wiring layer 921f is connected to the pad portion P5 and electrically connected to the first light source 621e which is more distant from the protruding portion 910b than the pad portion P5. Further, the extending portion P8 of the fifth wiring layer 921j is connected to the pad portion P7 and electrically connected to the fourth light source 620h closer to the projecting portion 910b than the pad portion P7. The Y-direction length of the extension portion P8 is shorter than the Y-direction length of the extension portion P4 in the first row MT1.

However, the wiring pattern of the wiring layer group 921S belonging to the second row MT2 may be the same as the wiring pattern of the wiring layer group 921S belonging to the first row MT1. The wiring pattern of the wiring layer group 921S belonging to the rows MT from the second row MT2 to the last row MTn may be the same as the wiring pattern of the wiring layer group 921S belonging to the first row MT1. The wiring pattern may be the same as the wiring pattern of the wiring layer group 921S belonging to MT2.

In this embodiment, the pad portions P1 and P5 function as anodes, and the pad portions P3 and P7 function as cathodes.

Next, a connection structure between the wiring board 910 and the light emitting module 920 will be described.
38 is a schematic bottom view showing an enlarged portion surrounded by broken line XXXVIII in FIG. 34. FIG.
FIG. 39 is a schematic bottom view showing an enlarged portion surrounded by broken line XXXIX in FIG. 38 in the wiring board according to the present embodiment.
FIG. 40 is a schematic bottom view showing an enlarged portion of the wiring board and the light emitting module in this embodiment, which is surrounded by the dashed line XXXIX in FIG.
41 is a schematic cross-sectional view along line XLI-XLI in FIG. 40. FIG.
The wiring board 910 includes an insulating layer 911, a plurality of first wiring layers 912 provided under the insulating layer 911 and electrically connected to the pad portions P3 and P7, and a wiring board 910 provided under the insulating layer 911 and the pads. and a plurality of second wiring layers 917 electrically connected to the portions P1 and P5. Moreover, the wiring board 910 further has an identification display 913 provided on the insulating layer 911, as shown in FIG. Moreover, the wiring board 910 may further have a covering layer (not shown) provided under the plurality of first wiring layers 912 and the second wiring layers 917 .

The insulating layer 911 is made of the same material as the insulating layer 116 in the first embodiment. The insulating layer 911 may be attached to the light emitting module 920 with an adhesive sheet or the like. The insulating layer 911 may consist of one layer or may consist of a plurality of layers. As shown in FIGS. 40 and 41, in the insulating layer 911, through holes 911a are provided directly below the pad portions P1, P3, P5, and P7. Each through hole 911a penetrates the insulating layer 911 in the Z direction. The shape of each through-hole 911a in the top view is circular in this embodiment. However, the shape of each through-hole is not limited to the shape described above, and may be polygonal such as quadrangular, elliptical, or the like. A wiring member 930 is provided in each through hole 911a.

Each wiring member 930 is electrically connected to one of the plurality of pad portions P1, P3, P5, and P7, which is located directly above. In addition, in FIGS. 38, 39, and 40, the regions in which the wiring members 930 are provided are indicated by dots in order to facilitate the explanation. Each wiring member 930 is formed by curing a conductive paste.

As shown in FIG. 38, each first wiring layer 912 has one end located on the protruding portion 910b of the wiring substrate 910 and extending over the main body portion 910a of the wiring substrate 910 . That is, one ends of the plurality of first wiring layers 912 are concentrated on the projecting portion 910b. Each first wiring layer 912 is in contact with one or more wiring members 930 connected to the pad portions P3 and P7, as shown in FIG. Thereby, the plurality of first wiring layers 912 and the cathodes of the plurality of wiring layer groups 921S of the light emitting module 920 are electrically connected. One ends of the plurality of first wiring layers 912 gathered on the protruding portion 910b are electrically connected to an external drive substrate or the like that drives the planar light source 1000. FIG.

Each second wiring layer 917 extends over the main body portion 910 a of the wiring substrate 910 . Each second wiring layer 917 is in contact with one or more wiring members 930 connected to the pad portions P1 and P5. Thereby, the plurality of second wiring layers 917 and the anodes of the plurality of wiring layer groups 921S of the light emitting module 920 are electrically connected.

Thus, the wiring substrate 910 is provided with a plurality of first wiring layers 912 . Then, the end portions of the plurality of first wiring layers 912 are collected at the projecting portion 910b. At this time, in a region in the vicinity of the projecting portion 910b in the main body portion 910a, some of the plurality of first wiring layers 912 are concentrated so as to be aligned in the Y direction. In addition, in the plurality of first wiring layers 912, the portions that are concentrated so as to be aligned in the Y direction on the main body portion 910a are closer to each other than the wiring member 930 electrically connected to the wiring layer group 921S belonging to the first row MT1. , on the side of the protrusion 910b in the Y direction.

A wiring member 930 electrically connected to the wiring layer group 921S belonging to the first row MT1 is positioned directly below the pad portion P3 in the first row MT1. Therefore, the closer the pad portion P3 is to the outer edge of the light-emitting module 920 on the side of the projecting portion 910b in the Y direction, the more the portions of the plurality of first wiring layers 912 that are aligned in the Y direction on the main body portion 910a are gathered. It is necessary to shift to the protrusion 910b side in the Y direction. In this case, it is necessary to increase the dimension of the body portion 910a in the Y direction so that the plurality of first wiring layers 912 can be accommodated inside the outer edge of the body portion 910a. On the other hand, in the present embodiment, the pad portion P3 of the wiring layer group 921S belonging to the first row MT1 is more distant from the projecting portion 910b in the Y direction than the plurality of light sources 620 to which the wiring layer group 921S is connected in series. isolated. Therefore, the pad portion P3 can be separated from the outer edge of the light emitting module 920 on the side of the projecting portion 910b in the Y direction. Accordingly, the plurality of first wiring layers 912 can be formed inside the outer edge of the wiring substrate 910 without increasing the dimension of the main body portion 910a in the Y direction. Therefore, the wiring board 910 can be made compact.

The identification display 913 is, for example, a display for identifying product lots. The identification display 913 is, for example, a two-dimensional code such as a data matrix, a one-dimensional code such as a bar code, or a character code made up of a combination of letters, numbers, symbols, or the like. The identification display 913 is made of a metal material such as copper. The identification display 913 is arranged on the upper surface of the projecting portion 910b as shown in FIG. 34 in this embodiment. The insulating layer 911 described above is interposed between the plurality of wiring layers 912 and the identification display 913 . A display 913 for identification is exposed from the insulating layer 911 . However, the identification mark may be arranged on the lower surface of the protrusion or on the surface of the main body. In addition, the wiring substrate may not have an identification mark.

A metal layer such as copper arranged on the base layer 111 so as to be insulated from the wiring layers 113 and 114 can be used for the indication 913 for identification. In this case, the identification mark 913 can be formed by irradiating the metal layer with a laser or etching the metal layer to partially remove the metal layer.

As another example, the first coating layer 112 is placed on the upper surface of the metal layer described above, the first coating layer 112 is irradiated with a laser or the first coating layer 112 is etched, and the first coating layer 112 is partially removed. By doing so, a display 913 for identification can be formed. The removed regions in the first covering layer 112 may or may not be penetrating. The first coating layer 112 may be a transparent material, and from the viewpoint of enhancing visibility, it is preferably a white material or a colored material such as green or blue. In addition, when the metal layer is arranged on the lower surface of the base layer, the second coating layer 115 is arranged on the surface of the metal layer, and the second coating layer 115 is irradiated with a laser or etched by etching the second coating layer 115. , the second covering layer 115 is partially removed.

As yet another example, the identifying indicia 913 can be formed by applying or printing a white or colored resin, or by applying a sticker.

Note that the configuration of the wiring board 910 is not limited to the above. For example, the thickness of the distal end portion of the projecting portion 910b in the Y direction may be thicker than the thickness of the proximal end portion (the portion connected to the main body portion 910a) of the projecting portion 910b in the Y direction. Such a tip portion can be formed, for example, by providing a sheet made of a resin material such as polyimide on the tip portion of the projecting portion 910b.

FIG. 42 is a schematic bottom view showing another example of the wiring board in this embodiment.
Further, for example, as shown in FIG. 42, the wiring substrate 910 may be provided with an anisotropic conductive film 910d, and the plurality of first wiring layers 912 may be collected in the anisotropic conductive film 910d. In FIG. 42, the anisotropic conductive film 910d is provided on the projecting portion 910b. A terminal 910c for connecting to an external driving substrate may be connected to the protrusion 910b so as to be electrically connected to the anisotropic conductive film 910d. That is, the plurality of first wiring layers 912 may be electrically connected to the terminal 910c through the anisotropic conductive film 910d. Also, the wiring substrate may not be provided with a plurality of projecting portions. In this case, a plurality of anisotropic conductive films may be provided on the lower surface of the main body, and a plurality of wirings may be concentrated on each anisotropic conductive film. A terminal may be electrically connected to each anisotropic conductive film.

Also, the wiring layer group 921S may be provided not on the light emitting module 920 but on the upper surface of the wiring substrate 910, for example, on the insulating layer 911. FIG. At least the portions of the wiring layers 912 and 917 in contact with the wiring member 930 should be located under the insulating layer 911 . Therefore, for example, the wiring layers 912 and 917 have a first portion provided under the insulating layer 911 and in contact with the wiring member 930 , a second portion provided above the insulating layer 911 , and a portion penetrating the insulating layer 911 . , and a third portion connecting the first portion and the second portion. Also, the wiring layers 912 and 917 may be separated from the through hole 911 a provided in the insulating layer 911 . The wiring member 930 has a first portion that fills the inside of the through hole 911a, and a second portion that is arranged under the insulating layer 911, continues to the first portion, and is in contact with the wiring layers 912 and 917. may The wiring layer group 921S can also have a wiring pattern in which the wiring pattern shown in FIG. 37 is inverted with respect to the axis extending in the Y direction.

Next, the effects of this embodiment will be described.
In the planar light source 1000 according to the present embodiment, in the wiring layer group 921S belonging to the first row MT1, the pad portion P3 protrudes in the Y direction from the plurality of light sources 620 to which the wiring layer group 921S is connected in series. 910b. Accordingly, the plurality of first wiring layers 912 can be formed inside the outer edge of the wiring board 910 without increasing the dimension of the main body 910a in the Y direction. Therefore, the wiring board 910 can be made compact.

In addition, in the present embodiment, in the wiring layer group 921S adjacent to the wiring layer group 921S belonging to the second row MT2 in the bottom view, the pad portions P5 and P7 are connected in series with the wiring layer group 921S. Located between light sources 620 . Thereby, the distance between the pad portions P1 and P3 in the first row MT1 and the pad portions P5 and P7 in the second row MT2 can be shortened. As a result, the distance between the through holes 911a in the insulating layer 911 located directly under the pads P1 and P3 and the through holes 911a in the insulating layer 911 located directly under the pads P5 and P7 can be shortened. When the planar light source 1000 is driven, the temperature of the planar light source 1000 rises or falls depending on whether each light source 620 is lit or not. As a result, the wiring board 910, the adhesive sheet, the light emitting module 920, and the wiring member 930 that constitute the planar light source 1000 may be deformed. At this time, since the coefficients of thermal expansion are different from each other, stress is applied to the wiring member 930, and cracks may occur. In the present embodiment, as described above, the distance between the through hole 911a in the insulating layer 911 located directly under the pad portions P1 and P3 and the through hole 911a in the insulating layer 911 located directly under the pad portions P5 and P7 is By shortening , the stress acting on the wiring member 930 can be relaxed. As a result, the occurrence of cracks in the wiring member 930 can be suppressed.

<Modification>
Next, a modification of the ninth embodiment will be described.
FIG. 43 is a schematic bottom view showing an enlarged part of the wiring board in this modification.
As shown in FIG. 43, part of the outer periphery of the wiring board 910 may have a shape that conforms to the shape of the outermost first wiring layer 912 a among the plurality of first wiring layers 912 . For example, in FIG. 43, in the body portion 910a, the side surface 910s to which the projecting portion 910b is connected extends in the X direction along the outer periphery of the light emitting module 920 and part of the first wiring layer 912a. Further, for example, in FIG. 43, the side surface of the projecting portion 910b has two steps along the first wiring layer 912a. As a result, the dimension of the body portion 910a of the wiring board 910 in the Y direction can be reduced.

In the above embodiments, the planar light source includes the light guide member, the partition member, the translucent member, the light adjustment member, and the like. However, the planar light source does not have to include the light guide member, the partition member, the translucent member, the light adjustment member, and the like. That is, the planar light source may be composed of a wiring board and a plurality of light sources.

The present invention can be used, for example, in backlights.

100, 200, 300, 400, 600, 700, 800, 1000: planar light source 110, 210, 710, 910: wiring board 111, 211, 711: base layer 112, 212, 712: first coating layer 113, 213 , 713: first wiring layer 113a, 713a: tip portion 113b: intermediate portion 113c: upper surface 113d: lower surface 113e: side surface 113s1: first region (region facing the first through hole)
113s2: second region 113s3: third region 114, 214: second wiring layer 114a, 714a: tip portion 114b: intermediate portion 114c: upper surface 114d: lower surface 114e: side surface region)
114s2: second region 114s3: third region 115, 215, 715, 815: second coating layer 115a: through hole 116, 216, 716, 911: insulating layer 116a, 216a, 716a: first through hole 116b, 216b, 716b: Second through hole 117, 217: Light reflective sheet 118a, 218a, 718: Adhesive sheet 118b, 218b: Adhesive sheet 119, 219: Sheet laminate 119a, 219a, 718a: Third through hole 119b, 219b, 718b : fourth through hole 120, 320, 620: light source 121, 321: body portion 122, 322: first terminal 123, 323: second terminal 124, 624: light emitting element 124a, 624a, 621a: light emitting portion 124b, 324b, 624b, 621b: first electrode 124c, 324c, 624c, 621c: second electrode 125, 623: translucent member 126: first light adjusting member 127, 624: covering member 130, 630: light guiding member 131, 631: Light source arrangement part 132, 632: partition groove 133, 634: translucent member 133a: first layer 133b: second layer 133Fa, 533Fa: first resin member 133Fb: second resin member 134: second light adjustment member 135, 633: Partition member 151, 251, 451, 751: First wiring member 151a, 451a, 751a: First part 151b, 451b, 751b: Second part 151F, 251F, 451Fa, 751F: First conductive paste 152, 252 , 452, 752: second wiring member 152a, 452a, 752a: third portion 152b, 452b, 752b: fourth portion 152F, 252F, 452Fa, 752F: second conductive paste 153: coating layer 451Fb: third conductive Paste 452Fb: Fourth conductive paste First opening: 715a
Second opening: 715b
Third opening: 715c, 815c
Fourth opening: 715d, 815d
900: Drill D1-D7: Distance E1, E2: Distance F1, F2: Dimension G: Direction of gravity L1, L2: Diagonal L3: Axis R: Light-emitting area S1: First gap S2: Second gap c1-c4: Center

Claims (18)

An insulating layer provided with a first through hole and a second through hole separated from each other; and a first wiring layer and a second wiring layer arranged under the insulating layer and separated from the first through hole and the second through hole. a wiring layer;
a wiring board having
a light source disposed on the wiring substrate and having a first electrode and a second electrode separated from each other;
a light guide member disposed on the wiring board and surrounding the light source;
a first portion filling the first through-hole and electrically connected to the first electrode; a first wiring member having two portions;
a third portion filling the inside of the second through hole and electrically connected to the second electrode; a second wiring member having four portions;
with
The first wiring layer and the second wiring layer are arranged so as to sandwich the first through hole and the second through hole when viewed from above,
A region of the side surface of the first wiring layer, which is in contact with the second portion and faces the first through hole when viewed from above, is concave in a direction away from the first through hole,
A planar light source, wherein a region of a side surface of the second wiring layer, which is in contact with the fourth portion and faces the second through hole when viewed from above, is concave in a direction away from the second through hole. 2. The planar shape according to claim 1, wherein the distance between the center of the first through hole and the center of the second through hole in top view is longer than the distance between the center of the first electrode and the center of the second electrode. light source. Each of the shape of the first through hole and the shape of the second through hole in a top view are circular,
The shape of the region that contacts the second portion and faces the first through hole when viewed from the top, and the shape of the region that contacts the fourth portion and faces the second through hole when viewed from the top 2. The planar light source of claim 1 , wherein each is arcuate. The light source is
a first terminal disposed under the first electrode, in contact with the upper end of the first portion, and having an area in top view equal to or larger than the area of the first electrode;
a second terminal disposed under the second electrode, in contact with the upper end of the third portion, and having an area in top view equal to or larger than the area of the second electrode;
The planar light source according to any one of claims 1 to 3 , further comprising The first terminal covers the first through hole in top view,
5. The planar light source according to claim 4 , wherein the second terminal covers the second through hole when viewed from above. 6. The planar light source according to claim 1, further comprising a coating layer covering said first wiring member and said second wiring member. Each of the first wiring member and the second wiring member has a base material made of a resin material, and at least one kind of metal particles provided in the base material. The planar light source according to 1. An insulating layer provided with a first through hole and a second through hole separated from each other; and a first wiring layer and a second wiring layer arranged under the insulating layer and separated from the first through hole and the second through hole. covering the periphery of the first through-hole and the second through-hole on the lower surface of the insulating layer so that the wiring layer, the first through-hole and the second through-hole are exposed; a wiring board having a covering layer exposing a part of the second wiring layer;
a light source disposed on the wiring substrate and having a first electrode and a second electrode separated from each other;
a light guide member disposed on the wiring board and surrounding the light source;
a first portion filling the first through hole and electrically connected to the first electrode; a first wiring member having a second portion in contact with the portion exposed from the layer;
a third portion filling the second through hole and electrically connected to the second electrode; a second wiring member having a fourth portion in contact with the portion exposed from the layer;
with
The covering layer includes a third opening that is separated from the first through hole and exposes a portion of the first wiring layer, and a third opening that is separated from the second through hole and exposes a portion of the second wiring layer. and a planar light source provided with a fourth aperture . 9. The planar light source according to claim 8 , wherein the covering layer is provided with a first opening exposing the first through hole and a second opening exposing the second through hole. 9. The planar light source according to claim 8 , wherein the distance between the third opening and the fourth opening is longer than the distance between the first through hole and the second through hole. 11. The planar light source according to any one of claims 1 to 10 , further comprising a light-reflecting sheet disposed on the wiring board in areas other than the first through holes and the second through holes. a material of the first wiring member and the second wiring member is a material containing a thermosetting material as a main component;
The main component of the light reflective sheet is a thermoplastic resin,
12. The planar light source according to claim 11 , wherein the melting point of the light reflective sheet is higher than the curing temperatures of the first wiring member and the second wiring member . An insulating layer provided with a first through hole and a second through hole separated from each other; and a first wiring layer and a second wiring layer arranged under the insulating layer and separated from the first through hole and the second through hole. a wiring layer, wherein the first wiring layer and the second wiring layer are arranged so as to sandwich the first through hole and the second through hole when viewed from above;
disposing a light guide member and a light source on the wiring substrate;
a first wiring member that fills the first through hole, is arranged under the insulating layer, is in contact with the first wiring layer, and is electrically connected to a first electrode of the light source; a second wiring member spaced apart from, filling the second through hole, disposed under the insulating layer, in contact with the second wiring layer, and electrically connected to the second electrode of the light source; forming;
with
In the step of arranging the light guide member and the light source on the wiring board, after the light guide member is arranged on the wiring board, the light source is arranged in a light source arrangement portion provided on the light guide member. A method for manufacturing a planar light source. The step of forming the first wiring member and the second wiring member includes:
A first conductive paste is filled in the first through hole and arranged to be in contact with the first wiring layer, a second conductive paste is filled in the second through hole, and the second conductive paste is arranged to be in contact with the first wiring layer. arranging so as to be in contact with two wiring layers;
curing the first conductive paste and the second conductive paste;
14. The method for manufacturing a planar light source according to claim 13 . The step of forming the first wiring member and the second wiring member includes:
filling a first conductive paste into the first through hole and filling a second conductive paste into the second through hole;
curing the first conductive paste and the second conductive paste;
A third conductive paste is placed in contact with the cured first conductive paste and the first wiring layer, and a fourth conductive paste is placed in contact with the cured second conductive paste and the second wiring. placing in contact with the layer;
curing the third conductive paste and the fourth conductive paste;
14. The method for manufacturing a planar light source according to claim 13 . The step of forming the first wiring member and the second wiring member includes:
filling a first conductive paste into the first through hole and filling a second conductive paste into the second through hole;
A third conductive paste is arranged so as to be in contact with the first conductive paste and the first wiring layer, and a fourth conductive paste is arranged so as to be in contact with the second conductive paste and the second wiring layer. and
curing the first conductive paste, the second conductive paste, the third conductive paste, and the fourth conductive paste;
14. The method for manufacturing a planar light source according to claim 13 . After the step of arranging the light guide member and the light source and before the step of forming the first wiring member and the second wiring member, in a light source arrangement portion provided in the light guide member, 17. The method of manufacturing a planar light source according to any one of claims 14 to 16 , further comprising placing a translucent resin member in a gap between the light guide member and the light source. the light source further comprises a first terminal located under the first electrode and a second terminal located under the second electrode;
18. The light source according to any one of claims 14 to 17 , wherein the light source is arranged such that the first terminal covers the first through hole and the second terminal covers the second through hole when viewed from above. A method for manufacturing a planar light source.

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