JP2010182809A - Semiconductor light-emitting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To radiate white light with small color tone unevenness to an irradiated surface, in a semiconductor light-emitting apparatus having a cavity structure package, which seals a semiconductor light-emitting element mounted in the cavity with a sealing resin which disperses one or more phosphors. <P>SOLUTION: In a semiconductor light-emitting apparatus, a red phosphor layer 7 is arranged so as to cover a blue LED element 5 mounted in a cavity 2. A green phosphor layer 8, a binder resin 9, and a second resin member 11 are sequentially arranged on the red phosphor layer. In addition, a relationship of a distance (a) from an upper surface 5a of the LED element 5 to an upper surface 10a of the first sealing resin 10, a thickness (b) of the second resin member 11, and a distance (c) from a light axis X to a periphery 11c, is set so that an angle θ between the light axis X of the LED element 5 and a line C crossing with the light axis X on the upper surface 5a of the LED element 5 and crossing with the periphery 11c of the upper surface 11a of the second resin member 11 becomes smaller than a critical angle τ of light ray incoming from the second resin member 11 to an air layer 12 (θ<τ). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor light emitting device, and more particularly to a semiconductor light emitting device comprising a combination of a semiconductor light emitting element and one or more kinds of phosphors.

  A semiconductor light-emitting device that uses a semiconductor light-emitting element as a light source and emits light having a color tone different from the emission color of the semiconductor light-emitting element generally has a light emission peak wavelength in the short wavelength side of the visible light region or in the ultraviolet region. It is comprised by the combination of a semiconductor light emitting element and 1 or more types of fluorescent substance.

  For example, when the semiconductor light emitting element is a blue LED element that emits blue light, the blue LED element is obtained by using a yellow phosphor that is wavelength-converted to yellow light that is excited by blue light emitted from the blue LED element and becomes a complementary color of blue. White light can be obtained by additive color mixing of yellow light, which is part of the blue light emitted from the light, and wavelength-converted by exciting the yellow phosphor, and a part of the blue light emitted from the blue LED element. .

  Similarly, when the semiconductor light emitting element is a blue LED element that emits blue light, two types of green phosphor and red phosphor that are excited by the blue light emitted by the blue LED element and convert the wavelength to green light and red light, respectively. By using a mixed phosphor made of a phosphor, a part of the blue light emitted from the blue LED element is emitted from the blue LED element and green light and red light whose wavelengths are converted by exciting the mixed phosphor. White light can be obtained by additive color mixing with a part of the blue light.

  Also, when the semiconductor light emitting device is an ultraviolet LED device that emits ultraviolet light, blue phosphor, green phosphor, and red fluorescence that are excited by the ultraviolet light emitted by the ultraviolet LED device and converted into blue light, green light, and red light, respectively. By using a mixed phosphor composed of three types of phosphors, an additive color mixture of blue light, green light and red light in which ultraviolet light emitted from an ultraviolet LED element is wavelength-converted by exciting the mixed phosphor Can produce white light.

  Furthermore, light of various color tones other than white light can be obtained by appropriately combining light of various color tones emitted from the LED element and a phosphor that is excited by the light and converts the wavelength to various wavelengths.

  As a specific semiconductor light emitting device 50, for example, one having a configuration as shown in FIG. 6 has been conventionally proposed.

  This is because a blue LED element 52 is mounted on the bottom surface of a package 51 having a cavity structure, and a mixed phosphor of a red phosphor and a green phosphor is filled in a light-transmitting thermosetting binder resin. The blue LED element 52 is resin-sealed with a sealing resin in which is dispersed.

  In this case, the red phosphor and the green phosphor have a specific gravity larger than that of the binder resin, and the median diameter of the red phosphor is larger than the median diameter of the green phosphor. Therefore, the red phosphor has a faster precipitation rate than the green phosphor in the binder resin, and a red color is preferentially provided in the vicinity of the blue LED element 52 below the binder resin 53 by providing a sufficient settling time after filling with the sealing resin. A phosphor is deposited to form a red phosphor layer 54, and a green phosphor is deposited thereon to form a green phosphor layer 55.

  Thus, by arranging the red phosphor layer 54 on the side of the blue LED element 52 that is the excitation light source, the red phosphor layer 54 is used for the red light emitted from the red phosphor excited by the blue light emitted from the blue LED element 52. Re-absorption and secondary excitation are not performed in the green phosphor layer 55 located above, and the luminance of the light emitting device is increased and the color tone of the light emitted from the light emitting device is shifted to the red side (warm color side) (spectrum distribution). It is possible to prevent the shift to the long wavelength side (see, for example, Patent Document 1).

JP 2005-277127 A

  Incidentally, as can be seen from the drawing, the light emitting surface 56 of the binder resin 53 is formed in a substantially flat shape, and the light emitting surface 56 has a refractive index lower than that of the binder resin 53. An interface with the air layer 57 outside the semiconductor light emitting device 50 is formed.

  Therefore, part of the blue light emitted from the blue LED element 52 excites the red phosphor layer 54 located in the vicinity of the blue LED element 52 to emit red light, and part of the blue light emits the red phosphor layer 54. The green phosphor layer 55 that is transmitted therethrough is excited to emit green light, and part of the light passes through the red phosphor layer 54 and the green phosphor layer 55 as blue light.

  Then, white light by the mixed light of red light, green light, and blue light is guided through the binder resin 53 and reaches the light emitting surface 56.

Of the white light that has reached the light exit surface 56, the angle L (intersection angle) θ formed with the normal N of the light exit surface 56 at the arrival point of the light exit surface 56 is smaller than the critical angle τ (θ <τ). _α is refracted by the light emitting surface 56 and emitted toward the air layer 57, and the light beam L _β whose intersection angle θ is the same as the critical angle τ (θ = τ) travels parallel to the light emitting surface 56.

On the other hand, the light beam L _γ having the intersection angle θ larger than the critical angle τ (θ> τ) is reflected (totally reflected) by the light emitting surface 56 and returns to the binder resin 53 side again, so that the air layer 57 from the light emitting surface 56. It is not emitted toward

Therefore, the light beam L _γ that has been totally reflected by the light emitting surface 56 and returned again to the binder resin 53 side is guided toward the bottom surface of the package 51, and the light beam L _{γ that} has reached the bottom surface is reflected by the bottom surface and re-executed again. Returning to the binder resin 53 side, the light is guided toward the light emitting surface 56, refracted by the light emitting surface 56, and emitted toward the air layer 57.

At this time, the light ray L _γ is red during the period from when it is totally reflected by the light emitting surface 56 to when it is reflected by the bottom surface of the package 51 and emitted from the light emitting surface 56 toward the air layer 57 (while the optical path is traveling). Each passes through the phosphor layer 54 and the green phosphor layer 55 twice.

Then, each time the light beam L _γ passes through each phosphor layer 54, 55, the amount of blue light that excites the phosphor layers 54, 55 is reduced, and the green light emitted from the green phosphor layer 55 is reduced. When the red phosphor layer 54 is excited (secondary excitation), the amount of red light increases and the amount of green light that serves as excitation light for the red phosphor layer 54 decreases.

  As a result, in the semiconductor light emitting device 50 that emits white light, as the reflection on the bottom surface of the package 51 is repeated, the color tone of the irradiated light shifts to the red side (warm color side) (shift to the long wavelength side of the spectrum distribution). ) Becomes partly large, resulting in a light emitting device having uneven color tone in the irradiated light.

  Therefore, in order to reduce the total reflection at the light exit surface, it is conceivable to make the light exit surface of the binder resin convex spherical or aspherical to the air layer side. Forming a spherical surface or an aspherical surface with resin filled in is difficult to realize in manufacturing, and even if it is realized, it is difficult to support automatic mounting on a wiring board because it is difficult to attract by an automatic machine.

  Accordingly, the present invention was devised in view of the above problems, and the object of the present invention is to disperse one or more kinds of phosphors in a semiconductor light emitting device having a cavity structure package and mounted in the cavity. An object of the present invention is to realize a semiconductor light emitting device capable of irradiating white light with little color tone unevenness on an irradiated surface in a semiconductor light emitting device sealed with a sealing resin.

In order to solve the above problems, the invention described in claim 1 of the present invention includes a package having a concave cavity,
A semiconductor light emitting device mounted on the bottom surface of the cavity;
One or more phosphor layers located on the bottom side of the cavity so as to cover the semiconductor light emitting element;
A binder resin which is located on the phosphor layer and forms a first sealing resin with the phosphor constituting the phosphor layer;
A second resin member disposed on the binder resin,
The upper surface of the second resin member is a method at the intersection of a straight line passing through the center of the upper surface of the semiconductor light emitting element and intersecting the upper surface of the second resin member, and the straight line of the upper surface of the second resin member. The angle formed with the line is set to be smaller than the critical angle with respect to the incident light from the center of the upper surface of the semiconductor light emitting device.

  In the invention described in claim 2 of the present invention, in claim 1, the upper surface of the second resin member is any one of a planar shape, a frustum shape, and a three-dimensional curved shape. It is characterized by being.

  According to a third aspect of the present invention, there is provided the semiconductor light emitting device according to any one of the first or second aspect, wherein the upper surface of the second resin member depends on the thickness of the second resin member. The angle formed by the normal line at the intersection of the straight line passing through the center of the upper surface of the second resin member and the straight line of the upper surface of the second resin member is the upper surface of the semiconductor light emitting element. It is characterized by being set to be smaller than the critical angle with respect to the incident light beam from the center.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the semiconductor light emitting element is a blue LED element, and the phosphor layer is from the bottom side of the cavity. A red phosphor layer and a green phosphor layer are arranged in this order.

  According to a fifth aspect of the present invention, in any one of the first to third aspects, the semiconductor light emitting element is an ultraviolet LED element, and the phosphor layer is formed from the bottom side of the cavity. A red phosphor layer, a green phosphor layer, and a blue phosphor layer are arranged in this order.

  In the semiconductor light emitting device of the present invention, one or a plurality of phosphor layers are arranged on the bottom surface side of the cavity so as to cover the semiconductor light emitting element mounted on the bottom surface in the cavity, and two kinds of resin layers are formed thereon. Arranged. And the angle formed by the normal line at the intersection of the straight line passing through the center of the upper surface of the semiconductor light emitting element and intersecting the upper surface of the upper resin layer with the straight line of the upper surface of the upper resin layer, the upper surface of the upper resin layer, It set so that it might become smaller than the critical angle with respect to the incident light from the resin layer side.

  By configuring the semiconductor light emitting device in such a manner, the light emitted from the semiconductor light emitting element and reaching the upper surface of the upper resin layer serving as a light emitting surface to the outside and the phosphor excited by the light from the semiconductor light emitting element Both of the light emitted and reaching the upper surface of the upper resin layer are irradiated to the outside without being reflected (total reflection) on the surface.

  As a result, the irradiation light from the semiconductor light emitting device is less likely to cause secondary excitation of the phosphor due to total reflection on the upper surface of the first sealing resin, and irradiates white light with less color shift and uneven color tone. It becomes possible to do.

  In addition, the irradiation light from the semiconductor light emitting device does not partially shift the color tone to the red side (warm color side) (shift to the long wavelength side of the spectrum distribution), and there is little color tone unevenness on the irradiated surface. It became possible to irradiate white light.

It is explanatory drawing which concerns on Example 1 of this invention. It is explanatory drawing which concerns on Example 2 of this invention. It is explanatory drawing of the application example which concerns on Example 2 of this invention. It is explanatory drawing which concerns on Example 3 of this invention. Similarly, it is explanatory drawing which concerns on Example 3 of this invention. It is explanatory drawing which concerns on a prior art example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIG. 1 to FIG. 5 (the same reference numerals are given to the same portions). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is an explanatory view of Example 1 according to the semiconductor light emitting device of the present invention.

  In the semiconductor light emitting device 30 of this embodiment, a plurality of conductor patterns 4a and 4b that are separated and independent from each other are positioned on the upper surface side of the bottom 3a of the package 3 having the concave cavity 2, and the side surfaces of the semiconductor light emitting device 30 penetrate through the package 3 respectively. It extends to the lower surface of the bottom 3a. The package 3 is made of a resin material such as glass epoxy resin.

  A blue LED element (hereinafter abbreviated as an LED element) 5 that emits blue light as a semiconductor light emitting element serving as a light emitting source is provided on a conductive pattern 4a located on the upper surface side of the bottom 3a of the package 3 with a conductive bonding member ( The lower electrode of the LED element 5 and the conductor pattern 4a are electrically connected. On the other hand, the upper electrode of the LED element 5 is connected to the conductor pattern 4b through the bonding wire 6 so that the upper electrode of the LED element 5 and the conductor pattern 4b are electrically connected.

  The LED element does not necessarily need to be of a type in which the electrode of the LED element and the conductor pattern are connected via a bonding wire, and may be of a flip chip type connected via a bump electrode.

  In the lower part of the cavity 2 where the LED element 5 is disposed, two types of phosphors, a red phosphor 7a that emits red light when excited by excitation light, and a green phosphor 8a that emits green light are translucent. Filled with a first sealing resin 10 which is dispersed in a thermosetting binder resin 9 having the following. At this time, the upper surface 10a of the first sealing resin 10 is formed in a planar shape.

  The first sealing resin 10 is provided with a sufficient settling time after filling into the cavity 2, whereby the red phosphor 7 a is preferentially deposited near the LED element 5 below the binder resin 9 and the red phosphor layer. 7 is formed and a green phosphor 8a is deposited thereon to form a green phosphor layer 8.

  In other words, a phosphor layer having a long emission wavelength (fluorescence wavelength) is deposited in order from the emission source side, and various methods are conceivable, but as described in “Background Art”, fluorescence that emits long-wavelength fluorescence. By increasing the median diameter of the body compared to the phosphor emitting short wavelength fluorescence, the stacking order can be controlled by the difference in the precipitation rate.

  A second resin member 11 made of a translucent resin is filled on the first sealing resin 10 in the cavity 2, and the upper surface 11 a is formed in a flat shape and the side wall portion of the package 3. It is located above the upper end 3d of 3b.

  The binder resin 9 and the second resin member 11 constituting the first sealing resin 10 may be different types of resin or the same type of resin. However, the binder resin 9 and the second resin member 11 differ depending on the difference in thermal expansion coefficient. In order to prevent total reflection or refraction of light at the interface between the binder resin 9 and the second resin member 11 due to separation at the interface with the resin member 11 and a difference in refractive index, the same type of resin is preferable.

  In that case, both the binder resin 9 and the second resin member 11 are preferably a silicone resin or an epoxy resin. When the nearby binder resin 9 is thermally expanded due to heat generated when the LED element 5 is turned on, the LED element 5 On the other hand, a silicone resin that is less affected by stress due to thermal expansion is more preferable.

Further, when both the refractive index of the binder resin 9 and the second resin member 11 are n, and the refractive index of the air layer 12 in contact with the upper surface 11a of the second resin member 11 is 1, the air from the second resin member 11 becomes air. The critical angle τ of the light incident on the layer 12 has a relationship of τ = sin ⁻¹ (1 / n).

Therefore, the distance from the upper surface 5a serving as the main light emitting surface of the LED element 5 to the upper surface 10a of the first sealing resin 10 is a, the thickness of the second resin member 11 is b, and the upper surface 5a of the LED element 5 is. If the distance from the optical axis X passing through the center to the outer periphery 11c of the upper surface 11a of the second resin member 11 is c, the relationship between a, b, c and τ is τ> tan ⁻¹ (c / (a + b) ).

  In other words, an angle θ formed by a straight line C passing through the center of the upper surface 5a of the LED element 5 and the outer periphery 11c of the upper surface 11a of the second resin member 11 passing through the center of the upper surface 5a of the LED element 5 is a critical angle. The relationship between a, b, and c is set so as to be smaller than τ (θ <τ).

  Therefore, the shape of the upper surface 11a of the second resin member 11 is not particularly limited as long as the relationship among a, b, c, and τ is satisfied. For example, the shape may be rectangular or circular. In the case of a circular shape, the LED element 5 has a circular shape with a radius c centered on the optical axis X.

  Moreover, it is preferable that the upper surface 10a of the first sealing resin 10 and the lower surface 11b of the second resin member 11 have the same shape and dimension and overlap each other to form an interface. The upper surface 11a of the second resin member preferably has the same shape.

  That is, the inner peripheral surface 3c of the side wall 3b of the package 3 that forms the cavity 2 filled with the first sealing resin 10 and the second resin member 11 is directed to the cylindrical shape or the irradiation direction of the LED element 5. It is preferable that the LED element 5 is composed of a continuous inclined surface opened in a direction away from the optical axis X.

  The filling of the first sealing resin 10 and the second resin member 11 into the cavity 2 is performed by a potting mold. On the package 3 filled with the first sealing resin 10 and cured at room temperature, 2 resin members 11 are filled and cured at room temperature. As a result, the upper surface 11a of the second resin member 11 can be made substantially flat, and the upper surface 11a can be used as a suction surface to enable automatic mounting on the wiring board, thereby improving production efficiency. it can.

  In the semiconductor light emitting device 30 having the above-described configuration, the conductive patterns 4a and 4b extended from the package 3 and the circuit patterns 13a and 13b formed on the wiring substrate 13 are connected to the wiring substrate 13 with a conductive bonding member 14 such as solder. Thus, the semiconductor light emitting module 1 is formed.

  Therefore, in the semiconductor light emitting module 1 of the present example configured as described above, the light beam L1 emitted from the LED element 5 toward the upper surface 11a of the second resin member 11 constitutes the first sealing resin 10. The red phosphor layer 7, the green phosphor layer 8, the binder resin 9 and the second resin member 11 are sequentially passed to reach the upper surface 11 a of the second resin member 11.

Light L1 that has reached the upper surface 11a of the second resin member 11 is incident at a small angle theta _L than the critical angle τ with respect to the upper surface 11a. Therefore, most of the light beam L reaching the upper surface 11a of the second resin member 11 is emitted as it is to the air layer 12 without being totally reflected by the upper surface 11a.

  Also, the light beam L2 emitted from the LED element 5 through the red phosphor layer 7, the green phosphor layer 8, the binder resin 9 and the second resin member 11 constituting the first sealing resin 10 in sequence is The portion is totally reflected by the side surface of the second resin member 11 and is emitted from the upper surface 11a.

  Therefore, almost all the light emitted from the LED element 5 toward the upper surface 11a of the second resin member 11 excites each of the red phosphor layer 7 and the green phosphor layer 8 only once, and the blue light There is no secondary excitation in which the red phosphor layer 7 is excited by the green light emitted by the green phosphor layer 8 that is excited by the blue light and the light amount is reduced.

  As a result, the irradiation light from the semiconductor light emitting module 1 does not partially shift the color tone to the red side (warm color side) (shift to the long wavelength side of the spectrum distribution), and uneven color tone on the irradiation surface. It is possible to irradiate with less white light.

  FIG. 2 is an explanatory view of Example 2 according to the semiconductor light emitting device of the present invention.

  The semiconductor light emitting device 30 according to the present embodiment is different from the first embodiment in that the upper surface of the second resin member is emitted to the air layer as it is without being totally reflected from the light beams emitted from the LED elements. The area is larger than that of the first embodiment.

  As a result, the semiconductor light emitting device 30 can irradiate the irradiated surface with white light with less uneven color tone as in the first embodiment, and the irradiation area of the light emitted from the LED element is larger than that in the first embodiment. Thus, the utilization efficiency of light is improved.

  Specifically, the upper surface 10a of the first sealing resin 10 is formed in a flat shape and is substantially flush with the upper end portion 3d of the side wall portion 3b of the package 3, and the first sealing resin 10 The upper surface 11a of the second resin member 11 located above the flat surface portion 11d having a plane intersecting the optical axis X and the outer periphery 11e of the flat surface portion 11d is directed in the direction opposite to the irradiation direction of the LED element 5. It consists of an inclined surface portion 11 f that opens in a direction away from the optical axis X of the LED element 5.

Among them, the flat surface portion 11d has both the refractive index of the binder resin 9 constituting the first sealing resin 10 and the second resin member 11 positioned on the first sealing resin 10 as in the first embodiment. n, the refractive index of the air layer 12 in contact with the upper surface 11a of the second resin member 11 is 1, and the distance from the upper surface 5a that is the main light emitting surface of the LED element 5 to the upper surface 10a of the first sealing resin 10 Is a, the distance from the lower surface 11b of the second resin member 11 to the flat surface portion 11d is b, and the second resin member from above the optical axis X passing through the center of the upper surface 5a serving as the main light emitting surface of the LED element 5. When the distance to the outer periphery 11e of the 11 flat portions 11d is c, the relationship between a, b, c, and τ is set to satisfy τ> tan ⁻¹ (c / (a + b)).

  In other words, the angle θ1 formed by the straight line C passing through the center of the upper surface 5a of the LED element 5 and the outer periphery 11e of the planar portion 11d of the second resin member 11 passing through the center of the upper surface 5a of the LED element 5 is critical. The relationship between a, b, and c is set so as to be smaller than the angle τ (θ1 <τ).

  Accordingly, the shape of the flat surface portion 11d of the second resin member 11 is not particularly limited as long as the relationship among a, b, c, and τ is satisfied. For example, the shape may be rectangular or circular. In the case of a circular shape, the LED element 5 has a circular shape with a radius c centered on the optical axis X.

  On the other hand, the inclined surface portion 11f is a continuous inclined surface having the upper end as the outer periphery 11e of the flat surface portion 11d and the lower end as the upper end portion 3d of the side wall portion 3b of the package 3, and passes through the center of the upper surface 5a of the LED element 5 to the inclined surface portion 11f. The angle θ2 formed by the straight line D intersecting with the normal line N1 at the intersection of the inclined surface portion 11f is set to be smaller than the critical angle τ (θ2 <τ).

  Filling the cavity 2 with the first sealing resin 10 is performed by potting mold, and the second resin member 11 is formed by a mold on the package 3 which is filled with the first sealing resin 10 and cured at room temperature. Alternatively, the second resin member 11 formed in a predetermined shape in advance can be attached to the first sealing resin 10 through the same material.

  Therefore, in the semiconductor light emitting device 30 of the present example configured as described above, the light beam L1 emitted from the LED element 5 toward the flat surface portion 11d of the second resin member 11 causes the first sealing resin 10 to be emitted. The red phosphor layer 7, the green phosphor layer 8, the binder resin 9, and the second resin member 11 are sequentially passed to reach the flat portion 11 d of the second resin member 11.

Light L1 having reached the flat portion 11d of the second resin member 11 is incident at a small angle theta _L1 than the critical angle τ with respect to the flat surface portion 11d. Therefore, most of the light beam L1 that has reached the flat surface portion 11d of the second resin member 11 is emitted directly to the air layer 12 without being totally reflected by the flat surface portion 11d.

  Therefore, almost all the light emitted from the LED element 5 and traveling toward the flat surface portion 11d of the second resin member 11 excites each of the red phosphor layer 7 and the green phosphor layer 8 only once, and the blue light There is also no secondary excitation in which the red phosphor layer 7 is excited by the green light emitted from the green phosphor layer 8 that is excited by the blue light and the light amount is reduced.

  On the other hand, the light beam L2 emitted from the LED element 5 toward the inclined surface portion 11f of the second resin member 11 is the red phosphor layer 7, the green phosphor layer 8, and the binder resin that constitute the first sealing resin 10. 9 and the second resin member 11 are sequentially passed to reach the inclined surface portion 11 f of the second member resin 11.

Light L2 having reached the inclined surface portion 11f of the second resin member 11 is incident at a small angle theta _L2 than the critical angle τ with respect to the normal N2 of the inclined surface portion 11f. Therefore, most of the light beam L2 reaching the inclined surface portion 11f of the second resin member 11 is emitted to the air layer 12 as it is without being totally reflected by the inclined surface portion 11f.

  Therefore, almost all the light emitted from the LED element 5 and directed to the inclined surface portion 11f of the second resin member 11 excites each of the red phosphor layer 7 and the green phosphor layer 8 only once, and the blue light There is also no secondary excitation in which the red phosphor layer 7 is excited by the green light emitted from the green phosphor layer 8 that is excited by the blue light and the light amount is reduced.

  As a result, the irradiation light from the upper surface 11a composed of the flat surface portion 11d and the inclined surface portion 11f of the second resin member 11 of the semiconductor light emitting device 30 is partially shifted to the red color side (warm color system side). There is no (shift to the long wavelength side of the spectral distribution), and it is possible to irradiate the irradiated surface with white light with little uneven color tone over a wide range.

  After the package 3 cured by filling the cavity 2 with the first sealing resin 10 by potting mold and curing at room temperature is mounted on the wiring substrate 13, it is fixed on the first sealing resin 10 by a liquid dispensing device. An amount of the second resin member 11 can be dropped and cured at room temperature.

  In this case, as shown in FIG. 3, the upper surface portion 11g of the second resin member 11 is a surface corresponding to the flat surface portion 11d of the second resin member 11 of the second embodiment, but slightly protrudes upward from the second embodiment. It is formed into a curved shape. However, the upper surface portion 11g made of this curved surface is less likely to be totally reflected by the light beam reaching from the same direction as the flat surface portion 11d made of the plane of Example 2, and the optical performance of the upper surface portion 11g of the second resin member 11 is as follows. It is not inferior to the flat portion 11d of the second resin member 11 of the second embodiment.

  In addition, the bay bending portion 11h of the second resin member 11 is a portion corresponding to the outer periphery 11e of the flat surface portion 11d of the second resin member 11 of the second embodiment. Formed. However, in the region with the R, the light beam reaching from the same direction is less likely to be totally reflected than the vicinity of the outer periphery 11e of the flat surface portion 11d, and the optical performance of the second resin member 11 at the bent portion 11h is the embodiment. It is not inferior to the vicinity of the outer periphery 11e of the flat portion 11d of the second resin member 11 of the second.

  Furthermore, the inclined portion 11i of the second resin member 11 is a surface corresponding to the inclined surface portion 11f of the second resin member 11 of the second embodiment. The inclined portion 11i made of this curved surface is less likely to be totally reflected by the inclined portion 11i made of the curved surface than the inclined surface portion 11f made of the plane of the second embodiment, and the second resin member 11 is inclined. The optical performance in the part 11i is not inferior to the inclined surface part 11f of the second resin member 11 of the second embodiment.

  4 and 5 are explanatory views of Example 3 according to the semiconductor light emitting device of the present invention.

  The semiconductor light emitting device 30 of the present embodiment has the basic configuration of the semiconductor light emitting device 30 of the first embodiment, is mounted on the wiring board 13, and the first sealing resin 10 and the second resin member 11 are contained in the cavity 2. The entire semiconductor light emitting device 30 filled with the LED element 5 and sealed with resin is covered with a resin lens 21.

  Therefore, as shown in FIG. 4, the refractive index of the binder resin 9 constituting the first sealing resin 10 and the second resin member 11 positioned on the first sealing resin 10 are both n1, and the second When the refractive index of the resin lens 21 in contact with the upper surface 11a of the resin member 11 is n2, when the refractive index n2 is greater than or equal to the refractive index n1 (n1 ≦ n2), the upper surface 5a serving as the main light emitting surface of the LED element 5 The distance to the upper surface 10 a of the first sealing resin 10 is a, the thickness of the second resin member 11 is b, and the optical axis X passes through the center of the upper surface 5 a that is the main light emitting surface of the LED element 5. Assuming that the distance from the second resin member 11 to the outer periphery 11c of the upper surface 11a of the second resin member 11 is c, the light beam L reaching the upper surface 11a of the second resin member 11 from the second resin member 11 side is not totally reflected, The light enters the resin lens 21. Therefore, there is no restriction between a, b and c, and each can be set freely (shown when n1 <n2 in the figure).

On the other hand, when the refractive index n2 is smaller than the refractive index n1, the critical angle τ = sin ⁻¹ (n2 / n1) of the light ray incident on the resin lens 21 from the second resin member 11 is obtained as shown in FIG. . Therefore, the relationship between a, b, c, and τ is set so that τ> tan ⁻¹ (c / (a + b)).

  In other words, an angle θ formed by a straight line C passing through the center of the upper surface 5a of the LED element 5 and the outer periphery 11c of the upper surface 11a of the second resin member 11 passing through the center of the upper surface 5a of the LED element 5 is a critical angle. The relationship between a, b, and c is set so as to be smaller than τ (θ <τ).

  Therefore, in the semiconductor light emitting module 20 of the present example configured as described above, the light beam L emitted from the LED element 5 toward the upper surface 11a of the second resin member 11 constitutes the first sealing resin 10. The red phosphor layer 7, the green phosphor layer 8, the binder resin 9 and the second resin member 11 are sequentially passed to reach the upper surface 11 a of the second resin member 11.

Light L that has reached the upper surface 11a of the second resin member 11 is incident at a small angle theta _L than the critical angle τ with respect to the upper surface 11a. Therefore, most of the light beam L reaching the upper surface 11a of the second resin member 11 is directly incident on the resin lens 21 without being totally reflected by the upper surface 11a.

  The light beam L that has entered the resin lens 21 is guided through the resin lens 21 and reaches the light exit surface 21a. The light emitting surface 21a is formed in a substantially spherical shape so as to cover the LED element 5 serving as a light emitting source, and the light beam L reaching the light emitting surface 21a is emitted to the external air layer 12 as it is without being reflected. The

  Therefore, almost all the light emitted from the LED element 5 toward the upper surface 11a of the second resin member 11 excites each of the red phosphor layer 7 and the green phosphor layer 8 only once, and the blue light There is no secondary excitation in which the red phosphor layer 7 is excited by the green light emitted by the green phosphor layer 8 that is excited by the blue light and the light amount is reduced.

  As a result, the irradiation light emitted through the resin lens 21 of the semiconductor light emitting module 20 has a partial shift of the color tone to the red side (warm color side) (shift to the long wavelength side of the spectral distribution). No, it becomes possible to irradiate the irradiated surface with white light with little color tone unevenness.

  In the above embodiment, a blue LED element is used as a light source, and white light is obtained by using two types of mixed phosphors of a red phosphor and a green phosphor. As described above, it is possible to obtain white light by using an ultraviolet LED element as a light source and using a mixed phosphor composed of three kinds of phosphors of a blue phosphor, a green phosphor and a red phosphor.

  In that case, each phosphor layer deposited in the cavity is a phosphor layer having a longer emission wavelength (fluorescence wavelength) in order from the emission source side in order to prevent secondary excitation and tertiary excitation by the second-excited phosphor. Specifically, the red phosphor layer, the green phosphor layer, and the blue phosphor layer are laminated in this order from the light emitting source side.

  Furthermore, it can of course be applied to a device that obtains a white color by using a blue LED element as a light emitting source and using a yellow phosphor. In this case also, secondary excitation that totally reflects on the upper surface of the sealing resin and excites the phosphor again. In order to prevent this, color unevenness can be reduced.

DESCRIPTION OF SYMBOLS 1 Semiconductor light emitting module 2 Cavity 3 Package 3a Bottom part 3b Side wall part 3c Inner peripheral surface 3d Upper end part 4a, 4b Conductor pattern 5 Blue LED element 5a Upper surface 6 Bonding wire 7 Red fluorescent substance layer 7a Red fluorescent substance 8 Green fluorescent substance layer 8a Green Phosphor 9 Binder resin 10 First sealing resin 10a Upper surface 11 Second resin member 11a Upper surface 11b Lower surface 11c Outer periphery 11d Plane portion 11e Outer periphery 11f Inclined surface portion 11g Upper surface portion 11h Wrapped portion 11i Inclined portion 12 Air layer 13 Wiring substrate 13a, 13b Circuit pattern 14 Conductive bonding member 20 Semiconductor light emitting module 21 Resin lens 21a Light exit surface 30 Semiconductor light emitting device

Claims (5)

A package having a concave cavity;
A semiconductor light emitting device mounted on the bottom surface of the cavity;
One or more phosphor layers located on the bottom side of the cavity so as to cover the semiconductor light emitting element;
A binder resin which is located on the phosphor layer and forms a first sealing resin with the phosphor constituting the phosphor layer;
A second resin member disposed on the binder resin,
The upper surface of the second resin member is a method at the intersection of a straight line passing through the center of the upper surface of the semiconductor light emitting element and intersecting the upper surface of the second resin member, and the straight line of the upper surface of the second resin member. A semiconductor light emitting device characterized in that an angle formed with a line is set to be smaller than a critical angle with respect to incident light from the center of the upper surface of the semiconductor light emitting element.   2. The semiconductor light emitting device according to claim 1, wherein an upper surface of the second resin member is one of a planar shape, a frustum shape, and a three-dimensional curved surface shape.   Due to the thickness of the second resin member, the upper surface of the second resin member passes through the center of the upper surface of the semiconductor light emitting element and intersects the upper surface of the second resin member, and the second resin member The angle formed by the normal line at the intersection of the upper surface with the straight line is set to be smaller than the critical angle with respect to incident light from the center of the upper surface of the semiconductor light emitting device. 3. The semiconductor light emitting device according to any one of 2 above.   The semiconductor light emitting element is a blue LED element, and the phosphor layer is a red phosphor layer and a green phosphor layer in order from the bottom surface side of the cavity. The semiconductor light-emitting device described in 1.   4. The semiconductor light emitting device is an ultraviolet LED device, and the phosphor layer is a red phosphor layer, a green phosphor layer, and a blue phosphor layer in order from the bottom surface side of the cavity. The semiconductor light-emitting device of any one of these.

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