JP5330306B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light source in which a light emitting element is sealed with glass, a manufacturing method thereof, and a light emitting device including the light source.

  Conventionally, a light source is known in which a GaN-based LED element is mounted on an element mounting substrate made of ceramic, and the LED element is sealed with a glass material on the element mounting substrate (see Patent Document 1). This light source is manufactured by mounting a plurality of LED elements on an element mounting substrate, sealing each LED element together with a plate-like glass material, and then cutting the element mounting substrate and the glass material by dicing. Is done. The light source manufactured in this way is in a state where the LED element is sealed by a rectangular parallelepiped glass sealing portion.

International Publication No. 2004/82036

  By the way, in the light source of patent document 1, since the shape of the glass sealing part was a rectangular parallelepiped shape, it was not easy to change the light distribution characteristic of a light source.

  The present invention has been made in view of the above circumstances, and its object is to provide a light source capable of easily and easily changing the light distribution characteristics even when the light emitting element is sealed with glass, and An object of the present invention is to provide a manufacturing method and a light emitting device including the light source.

In order to achieve the object, in the present invention, an element mounting substrate for mounting an LED element, a glass sealing portion for sealing the LED element on the element mounting substrate, and an upper surface of the glass sealing portion are formed. A light source made of a reflective layer; and a light guide plate having a hole in which the light source is accommodated, and the light source is mounted on an element mounting substrate provided on a lower surface of the light guide plate, and the hole of the light guide plate A light emitting device is provided in which the hole portion of the light guide plate has an inner surface parallel to a range in which light of the light source enters with respect to a thickness direction of the light guide plate .

In the light-emitting device , the glass sealing portion may be bonded to the element mounting substrate .

In the light emitting device , the reflective layer may be bonded to the glass sealing portion .

In the above light emitting device , the light emitting device may be formed of a polycrystalline Al ₂ O ₃ , Ag, or Al layer .

  According to the present invention, the light distribution characteristic can be easily and easily changed even when the light emitting element is sealed with glass.

FIG. 1 is a plan view of a light-emitting device showing a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the light emitting device. FIG. 3 is a cross-sectional view of the light source. FIG. 4 is an explanatory diagram when the light source is manufactured. FIG. 5 is an explanatory diagram when the light source is manufactured. 6A is a plan view of the light-emitting device, and FIG. 6B is a cross-sectional view of the light-emitting device. FIG. 7A is a partial cross-sectional view of the light emitting device. FIG. 7B is a table showing α satisfying the expressions (1) and (2) for each refractive index n of the light guide plate. FIG. 8 is a partial cross-sectional view of a light emitting device showing a modification. FIG. 9 is a partial cross-sectional view of a light emitting device showing a modification. FIG. 10 is a cross-sectional view of an intermediate body showing a modification. FIG. 11 is a cross-sectional view of a light source showing a modification. FIG. 12 is a cross-sectional view of a light source showing a modification.

  1 to 5 show a first embodiment of the present invention, FIG. 1 is a plan view of a light emitting device, and FIG. 2 is a sectional view of the light emitting device.

  As shown in FIG. 1, the light emitting device 1 includes a frame body 2 having a quadrangular shape in plan view and having an opening 21 on the upper side, and a plurality of light sources 3 arranged in the frame body 2. Each light source 3 is mounted on a plate-shaped mounting substrate 4, and the mounting substrate 4 is fixed to the frame 2 with screws 41 at four corners. In addition, the light emitting device 1 includes a diffusion plate 5 provided in the opening 21 of the frame 2, and each light source 3 is concealed by the diffusion plate 5. Each light source 3 is arranged in a lattice point on the mounting substrate 4 at equal intervals in the vertical direction and the horizontal direction.

  As shown in FIG. 2, the frame body 2 has a bottom portion 22 and a side wall 23, and a female screw portion 24 that is screwed into a screw 41 is provided on the bottom portion 22. The female screw portion 24 is provided so as to protrude upward from the bottom portion 22, and the mounting substrate 4 is placed on the female screw portion 24, so that the mounting substrate 4 is spaced apart from the bottom portion 22. Thereby, the heat of the mounting substrate 4 is not directly transmitted to the bottom 22.

  The mounting substrate 4 is based on aluminum and is provided in parallel with the bottom 22 of the frame 2. In the present embodiment, the mounting substrate 4 is disposed at a distance from each side wall 23. For example, the mounting substrate 4 includes a substrate body made of aluminum, an insulating layer provided on the substrate body, a circuit pattern provided on the insulating layer, and a white resist layer provided on the circuit pattern. It can be configured. With this configuration, the heat generated by the light source 3 is spread over the entire substrate by the mounting substrate 4, and the localization of the heat can be prevented.

  The diffusing plate 5 is provided at a distance from the light source 3 and the mounting substrate 4, and forms a light mixing space 6 of light emitted from each light source 3 between the light source 3 and the mounting substrate 4. Since the diffusion plate 5 diffuses the light emitted from each light source 3, the light is mixed also in the diffusion plate 5.

FIG. 3 is a cross-sectional view of the light source.
As shown in FIG. 3, the light source 3 includes an LED element 32 made of a flip-chip GaN-based semiconductor material, an element mounting substrate 33 on which the LED element 32 is mounted, an LED element 32 being sealed and an element mounting substrate 33. And a glass sealing portion 34 as an inorganic sealing portion to be bonded. In addition, a circuit pattern 35 that electrically connects the LED element 32 and the mounting substrate 4 is formed on the element mounting substrate 33. The circuit pattern 35 has a surface pattern formed on the surface of the element mounting substrate 33, a back surface pattern formed on the back surface of the element mounting substrate 33, and a via pattern connecting the surface pattern and the back surface pattern. .

The element mounting substrate 33 is made of a polycrystalline sintered material of alumina (Al ₂ O ₃ ) and has a thickness of 250 μm and a 1000 μm square. The LED element 32 is 100 μm thick and 346 μm square. That is, as shown in FIG. 2, the distance from the side edge of the LED element 32 to the side surface 34b of the glass sealing portion 34 is 327 μm, and the distance from the upper end of the LED element 32 to the upper surface 34a of the glass sealing portion 34 is 500 μm. It has become.

The glass sealing portion 34 covers the LED element 32 mounting surface side of the element mounting substrate 33 together with the LED element 32, and has a thickness of 0.6 mm. It has an upper surface 34a parallel to the element mounting substrate 33, and a side surface 34b extending downward from the outer edge of the upper surface 34a and perpendicular to the element mounting substrate 3. The glass sealing part 34 can be made of, for example, ZnO—B ₂ O ₃ —SiO ₂ glass, and the refractive index in this case is 1.7. Further, this glass is a heat-sealed glass fused to the element mounting substrate 33 by heating, and is different from a glass formed by utilizing a sol-gel reaction. The composition and refractive index of the glass are not limited to these.

  Further, the glass sealing portion 34 includes a phosphor 39 that converts the wavelength of light emitted from the LED element 32. As the phosphor 39, for example, a YAG (Yttrium Aluminum Garnet) phosphor, a silicate phosphor, or the like can be used. In the present embodiment, white light is obtained from the blue LED element 32 and the yellow phosphor 39. In addition, you may make it obtain white light by the combination of the LED element which emits blue light, a green fluorescent substance, and a red fluorescent substance.

A reflective layer 38 having a thickness of 0.1 mm is formed on the upper surface 34 a of the glass sealing portion 34. The reflection layer 38 only needs to reflect at least a part of the light emitted from the light source 3 and may not transmit at all or may be semi-transmissive. In the present embodiment, the reflective layer 38 is an inorganic material and is the same material as the element mounting substrate 33. Specifically, the reflective layer 38 is made of a polycrystalline sintered material of alumina (Al ₂ O ₃ ). That is, the reflective layer 38 is semi-transmissive to reflect some light and transmit some light.

  The light source 3 emits blue light from the LED element 32 when a voltage is applied to the LED element 32. Part of the blue light emitted from the LED element 32 is emitted to the outside after being converted into yellow by the phosphor 39. The light source 3 is perpendicular to the element mounting substrate 33, and an axis passing through the center of the upper surface 34a is an optical axis. Even if the reflective layer 38 is not formed, the light source 3 does not have the maximum light intensity on the optical axis, and the light intensity in a direction inclined by about 30 ° to 45 ° with respect to the optical axis. Has the maximum light distribution characteristic.

  In addition, since the reflective layer 38 is formed on the upper surface 34 a of the glass sealing portion 34, part of the light incident on the upper surface 34 a is reflected into the glass sealing portion 34. Further, since the reflective layer 38 is semi-transmissive, a part of the light is transmitted through the reflective layer 38 and emitted from the upper surface of the reflective layer 38 to the outside. As a result, the amount of light emitted upward from the light source 3 decreases, and the amount of light emitted laterally increases. The light source 3 of the present embodiment has a light distribution characteristic that maximizes the light intensity in a direction inclined by approximately 45 ° to 90 ° with respect to the optical axis. Thus, by providing the reflective layer 38, the light distribution characteristic can be widened laterally, and the amount of light emitted from above can be reduced. This light source 3 is manufactured through the following steps.

  First, the glass component oxide powder and phosphor powder are heated to 1200 ° C. and stirred in a molten state. And after solidifying glass, it slices so that it may correspond to the thickness of the glass sealing part 34, and the glass 34c before sealing is processed into plate shape.

  On the other hand, a circuit pattern is formed on the flat element mounting substrate 33. For example, the circuit pattern 35 is obtained by screen-printing a metal paste and heat-treating the element mounting substrate 33 at a predetermined temperature (for example, 1000 ° C. or more) to burn the metal on the element mounting substrate 33, and then apply another metal to the metal. It can form by performing plating of. Thereafter, the plurality of LED elements 32 are mounted on the element mounting substrate 33 by flip chip connection at equal intervals in the vertical and horizontal directions. In addition, the circuit pattern of the element mounting substrate 33 may be only formed by heat treatment of a metal paste, or may be formed by other methods such as a metal plating after metal sputtering.

  Then, as shown in FIG. 4, the element mounting board 33 on which the LED elements 32 are mounted is set on the lower mold 91, and the upper mold 92 is arranged to face the mounting surface of the element mounting board 33. A pre-sealing glass 34c is disposed between the element mounting substrate 33 and the upper mold 92 so as to cover the mounting area of each LED element 32, and the alumina that forms the reflective layer 38 above the pre-sealing glass 34c. Place the board.

Thereafter, as shown in FIG. 5, the lower mold 91 and the upper mold 92 are pressurized, and hot pressing of the glass material softened by heating in a nitrogen atmosphere is performed. The pre-sealing glass 34c can be heated and softened by hot pressing to be bonded to the element mounting substrate 33, and the pre-sealing glass 34c can be bonded to the reflective layer 38. In this way, on the element mounting substrate 33 mounted with a plurality of LED elements 32 and made of an inorganic material, the LED elements 32 are collectively sealed with a glass material to produce the intermediate 36. The reflective layer forming step of forming the reflective layer 38 on the upper surface of the glass material of the intermediate body 36 is simultaneously performed. The sealing step and the reflective layer forming step need not be performed at the same time. For example, when the element mounting substrate 33 and the reflective layer 38 are made of different materials or have different bonding states with glass, the first step is performed. Alternatively, the intermediate body 36 can be manufactured under the first condition, and the reflective layer 38 can be manufactured under the second hot press condition later. The processing conditions at this time can be arbitrarily changed according to the temperature, pressure, etc. of the glass, but if an example is given, for example, using a sol-gel glass in which an oxide or the like serving as a reflective material is dispersed, The first condition may be a temperature of 150 ° C. and no pressure, the second hot press condition may be a glass temperature of 600 ° C. and a glass pressure of 25 kgf / cm ² .

  Through the above steps, the intermediate body 36 in which the plurality of light emitting devices 1 are connected in the vertical direction and the horizontal direction, and the reflective layer 38 on the intermediate body 36 are formed. Thereafter, the element mounting substrate 33 integrated with the glass sealing portion 34 is set in a dicing apparatus, and the glass sealing portion 34 and the element mounting substrate 33 are diced by the dicing blade so that each LED element 32 is divided. To do. That is, a dividing step is performed in which the intermediate body 36 on which the reflective layer 38 is formed is divided in the thickness direction of the element mounting substrate 33 so that the side surface 34b of the glass material is exposed while the upper surface 34a of the glass material is covered. The light source 3 is completed.

  According to the light emitting device 1 configured as described above, the light distribution characteristics of the light source 3 are wide in the lateral direction, and the amount of light emitted from above the light source 3 is small, so the distance between the diffuser plate 5 and the light source 3 is small. Even if it does, the brightness nonuniformity of the light radiated | emitted from the diffusion plate 5 does not arise, and uniform surface light emission is realizable.

  Further, since the intermediate body 36 is divided by dicing after forming the reflective layer 38 on the upper surface of the intermediate body 36, the reflective layers 38 of the respective light sources 3 can be collectively formed, and mass production of the light sources 3 can be performed. Sex is not impaired. Furthermore, since the reflective layer 38 is bonded to the glass sealing portion 34 by hot pressing, the bonding strength of the reflective layer 38 can be made relatively high. Furthermore, the light distribution characteristics and the upper luminance of the light source 3 can be adjusted by changing the material, thickness, and the like of the reflective layer 38, and the light distribution characteristics and the luminance can be easily adjusted.

6 and 7 show a second embodiment of the present invention. FIG. 6A is a plan view of the light emitting device, and FIG. 6B is a cross-sectional view of the light emitting device.
6A and 6B, the light emitting device 101 includes a light guide plate 102, a plurality of through holes 121 formed in the light guide plate 102, a light source 3 accommodated in the through holes 121, and And a mounting substrate 104 electrically connected to the light source 3. Since the light source 3 is the same as that of the first embodiment, it will not be described in detail here. The light guide plate 102 is made of a material that is transparent to the light emitted from the light source 3, and the light emitted from the light source 3 in the through hole 121 is incident thereon.

  In the present embodiment, the light guide plate 102 is formed in a flat plate shape having a constant thickness throughout. The material of the light guide plate 102 is arbitrary as long as it is transparent to the light of the light source 3, but may be acrylic resin, for example. Here, in this specification, one surface of the light guide plate 102 is described as the upper surface 122 and the other surface is described as the lower surface 123. A scattering surface is formed on the lower surface 123 by white paint, surface roughening, prism formation, or the like.

  The through-hole 121 serving as a hole is parallel to the thickness direction of the light guide plate 102 in a range where light from the light source 3 is incident on the inner surface 124. In the present embodiment, the through-hole 121 has a square shape with a corner cut in plan view, and has the same cross section in the upper and lower sides. Specifically, the corner of the through hole 121 is curved with a predetermined radius of curvature. As described above, light is emitted upward and laterally from the light source 3, and the light from the light source 3 enters the entire range of the inner surface 124 of the through hole 121. In the present embodiment, the plurality of through holes 121 are regularly formed in the light guide plate 102 in plan view. Specifically, the through-holes 121 are arranged in a lattice point form on the entire surface of the planar light emitting device 101 at equal intervals in the vertical and horizontal directions.

  The light source 3 of 1.0 mm square in plan view is mounted at the center of the 1.5 mm square through hole 121 in plan view. In addition, the corner | angular part of the through-hole 121 is rounded so that a curvature radius may be set to 0.25. The light source 3 is accommodated in the through hole 121 so that the element mounting substrate 33 is on the lower surface 123 side of the light guide plate 102, and the optical axis is parallel to the thickness direction of the light guide plate 102.

FIG. 7A is a partial cross-sectional view of the light emitting device.
As shown in FIG. 7A, the mounting substrate 104 is based on aluminum and is provided along the lower surface 123 of the light guide 102. In the present embodiment, the mounting substrate 104 is provided so as to close the lower side of each through hole 121. The mounting substrate 104 includes a substrate body 141 made of aluminum, an insulating layer 142 provided on the substrate body 141, a circuit pattern 143 provided on the insulating layer 142, and a white resist layer provided on the circuit pattern 143. 144.

  As a result, the heat generated by the light source 3 spreads over the entire substrate by the mounting substrate 104, and the heat can be prevented from being localized and heat radiation to the outside can be promoted. At this time, the mounting substrate 104 along the light guide plate 102 should not be affected by the shape, such as being thick enough to impair the design of the planar light emitting device 101 while having a heat dissipation function. Can do. Further, as in the prior art, when a plurality of cylindrical hole-shaped or concave incident portions are arranged in parallel to the side surface portion on the back surface portion in the vicinity of at least one side surface portion of the light guide plate, the light source is localized and sufficient heat dissipation is achieved. When no countermeasure is taken, there is a problem that the light guide plate bends due to the localized heat. On the other hand, in the light emitting device 101 of the present embodiment, the light sources 3 are dispersedly arranged, and the heat of each light source 3 is distributed to the planar mounting substrate 104, so that external heat radiation is possible from a large area. The bending of the light guide plate 102 due to heat can be suppressed.

  The light source 3 having a height of 0.85 mm is mounted on the mounting substrate 104 via the solder 31. Thereby, the light source 3 is arranged at a height of 0.85 mm from the lower end of the through-hole 121 whose vertical length is 3 mm. That is, the end portion of the light source 3 on the element mounting substrate 33 side (in this embodiment, the back surface of the element mounting substrate 33) and the lower surface 123 of the light guide plate 102 have the same height position in the thickness direction of the light guide plate 102. It has become. As a result, the surface of the glass sealing portion 34 serving as the light emitting surface of the light source 3 is positioned higher than the lower surface 123 of the light guide plate 102 by the amount of the solder 31 and the element mounting substrate 33. Even in the case of being scattered and radiated from the three glass sealing portions 34, a lot of light comes directly into the inner surface 124 of the through hole 121.

Further, when the angle of the inner surface 124 of the through hole 121 with respect to the lower surface 123 of the light guide plate 102 is α and the refractive index of the light guide plate 102 is n,
90 ° −Sin ⁻¹ [{sin (90 ° −α)} / n] + α ≧ Sin ⁻¹ (1 / n) (1)
When all of the light traveling in the thickness direction of the light guide plate 102 is satisfied, all the light that has entered the light guide plate 102 from the inner surface 124 becomes propagation light in the light guide plate 102. In this embodiment, since α = 90 ° and n = 1.5, the condition of the above formula (1) is satisfied.

In addition to this,
α ≦ 90 ° −2 × Sin ⁻¹ [sin {(90 ° −α) / n}] (2)
If all of the light traveling along the inner surface 124 of the light guide plate 102 is satisfied, all the light that has entered the light guide plate 102 from the inner surface 124 becomes propagation light in the light guide plate 102. In this embodiment, since α = 90 ° and n = 1.5, the condition of the above formula (2) is satisfied.

  The solid angle β of the inner surface 124 of the through hole 121 with respect to the center of the upper surface 34a of the light source 3 of the inner surface 124 of the through hole 121 is 90% (5.65 steradian) or more with respect to 2πsteradian of the upper hemisphere. . The ratio of the solid angle of the inner surface 124 of the through-hole 121 to the center of the side surface 34b (target πsteradian on the upper side of the hemisphere on the side surface) is larger than the upper surface 34a. It can be said that the ratio is at least 90% or more. The direction in which the light intensity of the light source 3 is maximum is about 45 °, and the inner surface 124 exists in this direction.

  According to the light emitting device 1 configured as described above, the angle α of the inner surface 124 of the through hole 121 with respect to the lower surface 123 of the light guide plate 102 and the light guide plate 102 so as to satisfy the expressions (1) and (2). Therefore, most of the light incident from the inner surface 124 of the through hole 121 becomes the propagation light. As a result, special optics that controls the light emitted upward from the light source 3 to be in the in-plane direction of the light guide plate 102 even though the optical axis of the light source 3 is in the thickness direction of the light guide plate 102. Without using the automatic control unit for the light source 3 and the light guide plate 102, it is possible to obtain a function and effect that is contrary to technical common sense that light can be accurately incident into the light guide plate 102 to be propagated light of the light guide plate 102. be able to. Therefore, the number of parts can be reduced by omitting the optical control unit, and the light emitting device 101 can be manufactured easily and easily. Further, since at least 90% or more of the light emitted from the light source 3 is incident on the inner surface 124 of the light guide plate 102, the light emitted from the light source 3 can be used without waste. The propagating light that enters the through-hole 121 from the inside of the light guide plate 102 is incident again into the light guide plate 102 from the inner surface 124 at an angle that spreads more widely due to refraction.

  In this way, the light guide plate 102 is entirely formed by a very simple configuration in which a plurality of through holes 121 are regularly formed in two predetermined directions in the light guide plate 102 and the light source 3 is disposed in each through hole 121. Can emit light in white. At this time, the light sources 3 are arranged uniformly over the entire light guide plate 102, whereby a uniform light emission state of the light guide plate 102 can be realized. Accordingly, the light emitting device 1 can be reduced in thickness and size while reducing the manufacturing cost.

  In addition, since the through-hole 121 has a square shape with a curved corner when viewed in plan, and the square-shaped light source 3 is disposed on the inner side, the through-hole 121 is made smaller while being smaller than the circular through-hole. The amount of light incident on the hole 121 can be increased. On the other hand, in the present embodiment, refraction at the time of incidence of the light guide plate 102 is utilized, but refracted light is emitted only in a direction less than 45 ° with respect to the normal of each incident surface. The direction where light is not emitted will arise. On the other hand, by forming the corners in a square shape, it is possible to prevent the occurrence of a direction in which light is not emitted. In addition, although a corner is chamfered instead of forming a curve, a direction in which light is not emitted can be prevented from occurring, but a curved surface can smoothen the radiation intensity distribution.

  In addition, since the light source 3 having a wide light distribution characteristic is accommodated in such a light guide plate 102, variations in the light amount, color, and the like of each light source 3 can be averaged. In addition, since the amount of light emitted upward from the light source 3 is reduced, the light directly emitted from the through-hole 121 to the outside can be reduced to prevent direct light glare. Further, since the amount of light emitted from the side is increasing, the light coupling efficiency to the light guide plate 102 is good.

  Note that the ratio of the solid angle on the inner surface 124 of the through hole 121 to the center of the upper surface 34a of the light source 3 is not necessarily 90% or more with respect to 2πsteradian of the upper hemisphere, but it is 70% or more for optical efficiency. Is desirable. Furthermore, it is desirable that the inner surface 124 of the through hole 121 exists in the direction in which the light intensity of the light source 3 is maximized.

Here, the angle α of the inner surface of the through hole with respect to the other surface of the light guide plate will be described in detail with reference to FIGS. 7A and 7B.
When the light guide plate 102 is formed by injection molding, it may be preferable to form a slight taper (inclination) in the through hole 121 as shown in FIG. 7A. Here, FIG. 7B shows, for each refractive index n of the light guide plate 102, how much the inner surface 124 is smaller than 90 ° to satisfy the propagation conditions of the above formulas (1) and (2). As shown in FIG. 7B, when n is 1.45 or less, both formulas (1) and (2) may be 2.8 ° or less. When n is 1.50 or less, the condition of propagation is satisfied if the expression (1) is 6.7 ° or less, and the condition of propagation is satisfied if the expression (2) is 6.4 ° or less. When n is 1.55 or less, the propagation condition is satisfied if the expression (1) is 10.4 ° or less, and the propagation condition is satisfied if the expression (2) is 9.6 ° or less. When n is 1.60 or less, the condition for propagation is satisfied if the expression (1) is 13.9 ° or less, and the condition for propagation is satisfied if the expression (2) is 12.6 ° or less. Further, when n is 1.65 or less, the propagation condition is satisfied if the expression (1) is 17.3 ° or less, and the propagation condition is satisfied if the expression (2) is 15.4 ° or less. However, considering the flatness of the surface of the light guide plate 102 and the refractive index inside the light guide plate 102 is not strictly constant, basically, the inner surface 124 may be a vertical surface and the inclination angle may be less than 5 °. desirable.

  In the second embodiment, the light sources 3 are not limited to those arranged in the form of lattice points on the planar light emitting device 101, but may be those in which the central part is arranged densely or sparsely. . If the light source 3 is the light emitting device 101 arranged in the whole including the central portion, the light is propagated in the 360 ° direction in the surface of the light guide plate 102 using the refraction of the light guide plate, particularly with a small light source, and the light source is Unobtrusive features can be produced. Further, even when the light source is arranged only around the light guide plate, the feature that the light source is not conspicuous can be obtained.

  For example, as shown in FIG. 8, the upper surface 34 a of the light source 3 and the upper surface 122 of the light guide plate 102 may be at the same position. In this case, the thickness of the light guide plate 102 can be reduced, and the amount of light directly emitted from the through-hole 121 to the outside can be increased, so that the light source 3 portion can be accented by design.

  For example, as illustrated in FIG. 9, the through hole 121 that penetrates the light guide plate 102 may not be used, but a hole 121 a that is formed partway in the thickness direction from the lower surface 123. In FIG. 9, the blocking surface 125 of the hole 121 located above the light source 103 is parallel to the upper surface 122 and the lower surface 123 of the light guide plate 102 and is formed flat. Even in this case, the angle α is set so as to satisfy the expressions (1) and (2).

  In FIG. 9, the reflection layer 138 of the light source 103 is formed of a metal material. As the metal of the reflective layer 138, for example, Ag, Al, or the like can be used. The reflective layer 138 can be formed on the upper surface 34a of the glass sealing portion 34 by vapor deposition, sputtering, or the like. In manufacturing the light source 103, as shown in FIG. 10, a plurality of LED elements 32 are collectively sealed by the glass sealing portion 34 on the element mounting substrate 33 by hot pressing, and then the reflective layer. 138 may be formed by vapor deposition, sputtering, or the like, and the intermediate 136 may be cut by dicing.

  In the above embodiment, the phosphor 39 is dispersed in the glass sealing portion 34. For example, as shown in FIG. 11, the phosphor is interposed between the glass sealing portion 34 and the reflective layer 38. A phosphor layer 37 made of glass in which 39 is dispersed may be formed. In the light source 203, a difference in chromaticity occurs between the light emitted upward and the light emitted laterally. However, since the light is mixed in the light guide plate 102, there is no particular problem. The light source 203 can integrally bond the element mounting substrate 33, the glass sealing portion 34, the phosphor layer 237, and the reflective layer 38 by hot pressing.

For example, as shown in FIG. 12, the reflective layer 338 may be formed by dispersing diffusion particles 39a in a ceramic base material. For the diffusing particles 39a, a material having a refractive index different from that of the base material of the reflective layer 338 is selected. For the base material of the reflective layer 338 and the diffusing particles 39a, different materials are selected from materials such as ZrO, Al ₂ O ₃ , and SiO ₂ , for example. In the light source 303, the phosphor layer 337 is configured by dispersing the phosphor 39 in a ceramic base material.

  In the above embodiments, the light sources 3, 103, 203, and 303 have one LED element 32, but the light source may of course have a plurality of light emitting elements. For example, a light source in which a plurality of LED elements aligned in the vertical direction and the horizontal direction are mounted on a square-shaped element mounting substrate may be used. In addition, for example, a light source in which a plurality of LED elements arranged in a row are mounted on a rectangular element mounting substrate can be used.

  Moreover, in the said embodiment, although the light-emitting device using a LED element was demonstrated as a light-emitting element, a light-emitting element is not limited to a LED element, In addition, a concrete detailed structure etc. can be changed suitably. Of course.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Frame 3 Light source 4 Mounting board 5 Diffusion plate 32 LED element 33 Element mounting board 34 Glass sealing part 34a Upper surface 34b Side surface 34c Glass before sealing 35 Circuit pattern 36 Intermediate 37 Phosphor layer 38 Reflective layer 39 Fluorescence Body 39a Diffusing particles 91 Lower mold 92 Upper mold 101 Light emitting device 102 Light guide plate 103 Light source 104 Mounting substrate 121 Through hole 121a Hole 138 Reflective layer 203 Light source 237 Phosphor layer 303 Light source 337 Phosphor layer 338 Reflective layer

Claims (4)

A light source comprising an element mounting substrate for mounting the LED element, a glass sealing portion for sealing the LED element on the element mounting substrate, and a reflective layer formed on an upper surface of the glass sealing portion ;
A light guide plate having a hole portion in which the light source is accommodated,
The light source is mounted on an element mounting substrate provided on a lower surface of the light guide plate and is accommodated in a hole of the light guide plate.
The light emitting device, wherein the hole portion of the light guide plate has an inner surface parallel to a range in which light of the light source is incident with respect to a thickness direction of the light guide plate. The light emitting device according to claim 1, wherein the glass sealing portion is bonded to the element mounting substrate. The light emitting device according to claim 1, wherein the reflective layer is bonded to the glass sealing portion. The reflective layer is made of polycrystalline Al ₂ O ₃ The light emitting device according to claim 1, wherein the light emitting device is formed of a layer of Ag, Ag, or Al.

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