JP6774747B2 - Luminous module - Google Patents

Description

The present invention relates to a light emitting module.

Conventionally, a white light source using an LED has been devised. For example, a blue light emitting diode mounted on the bottom surface of a cup-shaped recess and a transparent resin portion in which two or more kinds of phosphors filled in the recess and excited by blue light to emit visible light other than blue are dispersed. A light emitting device having a light emitting device has been devised (see Patent Document 1). The transparent resin portion of this light emitting device has at least two or more layers containing different phosphors, and among those layers, the lower layer provided on the bottom surface side of the recess contains a red phosphor having a relatively wide excitation spectrum. A yellow phosphor having a relatively narrow excitation spectrum is contained in the upper layer provided on the opening side of the recess.

Further, the light emitting device includes a light emitting element that emits excitation light in the wavelength range of 370 nm to 420 nm on a substrate, and a wavelength conversion layer that converts the excitation light formed so as to cover the light emitting element into visible light. In the wavelength conversion layer, a blue phosphor that fluoresces from 430 nm to 490 nm, a green phosphor that fluoresces from 500 nm to 560 nm, a yellow phosphor that fluoresces from 540 nm to 600 nm, and fluorescence from 590 nm to 700 nm. A light emitting device containing a red phosphor that emits light has been devised (see Patent Document 2). In this light emitting device, the yellow phosphor and the red phosphor are contained in the second layer closer to the light emitting element than the first layer containing the blue phosphor and the green phosphor.

In addition, three types of phosphor layers are arranged on the light extraction side of the ultraviolet light emitting element and emit red light and wavelength conversion light of green light and blue light by being excited by receiving the light emitted from the ultraviolet light emitting element. A plate member for wavelength conversion in which at least two types of phosphor layers are laminated from the light emitting element side along the light extraction side, and red light as wavelength conversion light among the three types of phosphor layers is emitted. A light emitting device has been devised in which the emitted red phosphor layer is arranged at a position closer to the ultraviolet light emitting element than other phosphor layers (see Patent Document 3).

JP-A-2007-81090 JP-A-2007-103512 JP-A-2007-134656

However, the above-mentioned light emitting device has room for further improvement from the viewpoint of chromaticity, color rendering, and the like.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a new light emitting module having high color rendering properties.

In order to solve the above problems, the light emitting module of an embodiment of the present invention includes a light emitting element that emits ultraviolet rays or short wavelength visible light, and a light wavelength conversion layer that is excited by the light emitted by the light emitting element and emits visible light. .. The optical wavelength conversion layer has a first layer and a second layer provided on the opposite side of the light emitting element with the first layer interposed therebetween. The first layer and the second layer include a red phosphor, a green phosphor, a yellow phosphor and a blue phosphor. The first layer contains at least one of a red phosphor and a green phosphor. The second layer contains at least one of a yellow fluorophore and a blue fluorophore.

According to this aspect, since four phosphors having different colors of excitation light are included, a new light emitting module having high color rendering properties can be realized. Further, since the red phosphor or the green phosphor whose excitation spectrum exists up to the relatively long wavelength side is contained in the first layer close to the light emitting element, the yellow light or blue light excited in the second layer is emitted. Reabsorption in the first layer is suppressed, and color shift and reduction in light emission are reduced.

The first layer may contain a red fluorophore and a green fluorophore. The second layer may contain yellow and blue fluorophore. As a result, since the red phosphor and the green phosphor whose excitation spectrum exists up to the relatively long wavelength side are contained in the first layer close to the light emitting element, the yellow light and blue light excited in the second layer are included. Is suppressed from being absorbed in the first layer, and color shift and reduction in light emission are reduced.

The first layer may contain a red fluorophore. The second layer may contain a green fluorophore, a yellow fluorophore and a blue fluorophore. As a result, since the red phosphor having the excitation spectrum up to the relatively long wavelength side is included in the first layer close to the light emitting element, the yellow light and blue light excited in the second layer are the first. Reabsorption by the layer is suppressed, and color shift and reduction of light beam are reduced.

A substrate on which the light emitting element is mounted and a lead wire for electrically connecting the light emitting element and the substrate may be further provided. The first layer is a first resin layer in which a red phosphor and a green phosphor are dispersed and having an elastic modulus of 10 ⁴ to 10 ⁵ Pa at at least one of the temperatures in the range of -40 to 100 ° C. You may have. The first resin layer may be provided so as to seal the lead wire. As a result, the stress acting on the conducting wire can be relaxed.

The second layer may have a second resin layer having a Shore A hardness of 30 to 80 in which a yellow phosphor and a blue phosphor are dispersed. This protects the light emitting element.

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems and the like are also effective as aspects of the present invention.

According to the present invention, a novel light emitting module having high color rendering properties can be realized.

It is sectional drawing which shows the outline of the light emitting module which concerns on Example 1. It is a figure which shows an example of the excitation spectrum and the emission spectrum of the red phosphor used in an Example. It is a figure which shows an example of the excitation spectrum and the emission spectrum of the green phosphor used in an Example. It is a figure which shows an example of the excitation spectrum and the emission spectrum of the yellow phosphor used in an Example. It is a figure which shows an example of the excitation spectrum and the emission spectrum of the blue phosphor used in an Example. It is a side view which shows the outline of the light emitting module which concerns on Example 2. FIG. 6 is a sectional view taken along the line AA of the light emitting module shown in FIG. It is a figure which shows the emission spectrum of the light emitting module which concerns on Example 1, and the emission spectrum of the light emitting module which concerns on Comparative Example 1. It is a figure which shows the emission spectrum of the light emitting module which concerns on Example 2. FIG. It is sectional drawing which shows the outline of the light emitting module which concerns on Example 3. FIG. It is a figure which shows the change of the emission spectrum in the emission module which concerns on Example 3. FIG.

Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments. The same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and redundant description will be omitted as appropriate. Moreover, the embodiment is not limited to the invention but is an example, and all the features and combinations thereof described in the embodiment are not necessarily essential to the invention.

(Light emitting module)
The light emitting module according to the present embodiment includes a light emitting element that emits ultraviolet rays or short wavelength visible light, and a light wavelength conversion layer that is excited by the light emitted by the light emitting element and emits visible light. The optical wavelength conversion layer has a first layer and a second layer provided on the opposite side of the light emitting element with the first layer interposed therebetween. The first layer and the second layer include a red phosphor, a green phosphor, a yellow phosphor and a blue phosphor. The first layer contains at least one of a red phosphor and a green phosphor. The second layer contains at least one of a yellow fluorophore and a blue fluorophore.

(Light emitting element)
The emission spectrum of the light emitting element according to the present embodiment is not particularly limited as long as it emits at least ultraviolet rays or short wavelength visible light, but the emission spectrum peaks from the viewpoint of the luminous efficiency of the light emitting device and the like. Is preferably in the wavelength range of 350 nm to 430 nm.

Further, as specific examples of the light emitting element, for example, semiconductor light emitting elements such as LEDs, LDs, and ELs, light sources for obtaining light emission from vacuum discharge or thermal light emission, and various light sources such as electron beam excitation light emitting elements can be used. it can. By using a semiconductor light emitting element as the light emitting element, a compact, power-saving, long-life light emitting device can be obtained. As a preferable example of such a semiconductor light emitting device, an InGaN-based LED or LD having good light emitting characteristics in the wavelength region around 400 nm can be mentioned.

(Light wavelength conversion layer)
The light wavelength conversion layer according to the present embodiment is composed of a plurality of layers having different types and amounts of phosphors contained therein. The first layer close to the light emitting element may contain at least one of a red phosphor and a green phosphor. Further, the second layer provided on the side opposite to the light emitting element with the first layer interposed therebetween may contain at least one of a yellow phosphor and a blue phosphor.

As a whole, the first layer and the second layer contain at least four phosphors (for example, a red phosphor, a green phosphor, a yellow phosphor, and a blue phosphor) having different colors of excitation light, and thus color rendering. It is possible to realize a new light emitting module with high color rendering. Further, since the red phosphor or the green phosphor having the excitation spectrum up to the relatively long wavelength side is contained in the first layer close to the light emitting element, the first layer is farther from the light emitting element than the first layer. It is suppressed that the yellow light and blue light excited in the second layer are reabsorbed in the first layer, and the color shift and the decrease in the light beam are reduced.

(First layer)
The first layer contains (i) mainly red and green phosphors, (ii) mainly contains red phosphors, (iii) mainly contains green phosphors, and (iv) mainly contains red phosphors. , When containing green and yellow phosphors, (v) mainly containing red, green and blue phosphors, (vi) mainly containing red and yellow phosphors, (vi) mainly When it contains a green fluorescent substance and a yellow fluorescent substance, is mentioned. Each phosphor is dispersed in a sealing resin such as silicone or a matrix phase of glass. In the light wavelength conversion layer according to the present embodiment, the second layer may contain a phosphor having the same color as the phosphor contained in the first layer. For example, among the phosphors of a certain color contained in the entire light wavelength conversion layer, 90% or more may be contained in the first layer and 10% or less may be contained in the second layer. Alternatively, the first layer may contain 95% or more, and the second layer may contain 5% or less. Alternatively, the first layer may contain 98% or more, and the second layer may contain 2% or less.

The concentration of the entire phosphor contained in the first layer may be 0.2 vol% or more, preferably 0.5 vol% or more, and more preferably 0.8 vol% or more. When the concentration of the entire phosphor is 0.2 vol% or more, visible light having a sufficient luminous flux can be generated by the light emitted by the light emitting element. The concentration of the entire phosphor contained in the first layer may be 1.5 vol% or less, preferably 1.3 vol% or less, and more preferably 1.1 vol% or less. When the concentration of the entire phosphor is 1.5 vol% or less, the ratio of visible light excited by the phosphor being scattered and blocked by other phosphors is reduced, and the decrease in luminous efficiency of the light emitting module is suppressed. ..

(Second layer)
The second layer contains (i) mainly blue and yellow phosphors, (ii) mainly blue, yellow and green phosphors, and (iii) mainly blue and yellow fluorescence. Examples include the case where the body and the red fluorescent substance are contained, (iv) the case where the blue fluorescent substance is mainly contained, and (v) the case where the yellow fluorescent substance is mainly contained. Each phosphor is dispersed in a sealing resin such as silicone or a matrix phase of glass. In the light wavelength conversion layer according to the present embodiment, the first layer may contain a phosphor having the same color as the phosphor contained in the second layer. For example, among the phosphors of a certain color contained in the entire light wavelength conversion layer, 90% or more may be contained in the second layer and 10% or less may be contained in the first layer. Alternatively, the second layer may contain 95% or more, and the first layer may contain 5% or less. Alternatively, the second layer may contain 98% or more, and the first layer may contain 2% or less.

The concentration of the entire phosphor contained in the second layer may be 0.6 vol% or more, preferably 0.8 vol% or more, and more preferably 0.9 vol% or more. When the concentration of the entire phosphor is 0.6 vol% or more, visible light having a sufficient luminous flux can be generated by the light emitted by the light emitting element. On the other hand, when the concentration of the entire phosphor is less than 0.6 vol%, the second layer (fluorescent layer) becomes large (thick) in order to secure sufficient conversion performance, and a large amount of the matrix phase is used. The cost is high because the material is required. The concentration of the entire phosphor contained in the second layer may be 2.0 vol% or less, preferably 1.5 vol% or less, and more preferably 1.2 vol% or less. When the concentration of the entire phosphor is 2.0 vol% or less, the ratio of visible light excited by the phosphor being scattered and blocked by other phosphors is reduced, and the decrease in luminous efficiency of the light emitting module is suppressed. ..

(First resin layer)
The first resin layer is a matrix phase in which various phosphors contained in the first layer are dispersed. Specifically, the first resin layer, a storage elastic modulus at least one of temperature within the scope of -40 to 100 ° C. is preferably ¹⁰ 4 ^{to 10} 5 Pa silicone resin. Further, the first resin layer may be provided so as to seal the conducting wire (bonding wire). As a result, the stress acting on the conducting wire can be relaxed.

(Second resin layer)
The second resin layer is a matrix phase in which various phosphors contained in the second layer are dispersed. Specifically, the second resin layer is preferably a silicone resin having a shore A hardness of 30 to 80. As a result, the light emitting element is protected in the light emitting module covered with the second resin layer.

(Red phosphor)
The red phosphor emits light having a peak wavelength in the emission spectrum in the range of 620 nm to 750 nm, for example.
(I) (Ca _1-x Sr _x ) AlSiN ₃ : Eu ²⁺ (0 ≦ x <0.4)
(Ii) Sr ₂ Si ₅ N ₈ : Eu ²⁺
(Iii) (Ca, Sr, Ba) ₃ SiO ₅ : Eu ²⁺
Examples of the substance represented by the composition formula of.

(Green fluorescent substance)
The green phosphor emits light having a peak wavelength in the emission spectrum in the range of 495 nm to 570 nm, for example.
(I) (Ba, Sr, Ca) ₂ SiO ₄ : Eu ²⁺
(Ii) (Ba, Sr) ₂ SiO ₄ : Eu ²⁺
(Iii) Sr ₂ SiO ₄ : Eu ²⁺
(Iv) Live β Sialon with Eu (v) Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺
(Vi) SrGa ₂ S ₄ : Eu ²⁺
(Vii) SrSi ₂ O ₂ N ₂ : Eu ²⁺
(Viii) (Ba, Sr) Si ₂ O ₂ N ₂ : Eu ²⁺
(Ix) SrAlO ₄ : Eu ²⁺
(X) (Sr, Ba) Al ₂ Si ₂ O ₈ : Eu ²⁺
(Xi) (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu ²⁺
(Xii) Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu ²⁺
Examples of the substance represented by the composition formula of.

(Yellow phosphor)
The yellow phosphor emits light having a peak wavelength in the range of 570 nm to 590 nm in the emission spectrum. For example, the general formula is (M ² _x , M ³ _y , M ⁴ _z ) _m M ¹ O ₃ X ₍ M M ¹ O ₃ X ₍ M ² _x , M ³ _y , M ⁴ _z )). _{2 / n)}
(Here, M ¹ is at least one element containing at least Si selected from the group consisting of Si, Ge, Ti, Zr and Sn, and M ² is at least Ca selected from the group consisting of Ca, Mg, Ba and Zn. One or more elements including, M ³ is one or more elements including at least Sr selected from the group consisting of Sr, Mg, Ba and Zn, X is at least one halogen element, M ⁴ is a rare earth element and Mn. Indicates one or more elements including at least Eu ²⁺ selected from the group consisting of. In addition, m is in the range of 0.11 ≦ m ≦ 8/6 and n is in the range of 5 ≦ n ≦ 7. Also, x and y. , Z is a range that satisfies x + y + z = 1, 0 <x <1, 0 <y <1, 0.01 ≦ z ≦ 0.3).

(Blue phosphor)
The blue phosphor emits light having a peak wavelength in the emission spectrum in the range of 435 nm to 495 nm, for example.
(I) BaMgAl ₁₀ O ₁₇ : Eu ²⁺
(Ii) (Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺
(Iii) Ba ₃ MgSi ₂ O ₈ : Eu ²⁺
(Iv) Sr ₃ MgSi ₂ O ₈ : Eu ₂₊
(V) SiO _2- CaI ₂ : Eu ²⁺
(Vi) Sr ₄ Al ₁₄ O ₂₄ : Eu ²⁺
(Vii) (Ba, Sr, Ca) ₂ (B ₅ O ₉ ) X ₂ : Eu ²⁺ (X is a halogen element)
(Viii) (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu ²⁺
(Ix) Ca _5-x-y Mg _x (PO ₄ ) ₃ Cl: Eu ²⁺ _y
(X) Sr _5-y (PO ₄ ) ₃ Cl: Eu ²⁺ _y
(Xi) Ca _5-xy Sr _x (PO ₄ ) ₃ Cl: Eu ²⁺ _y
Examples of the substance represented by the composition formula of.

(Other phosphors)
In addition to the above-mentioned phosphors, or in place of some phosphors, orange phosphors or phosphors of other colors may be used. The orange phosphor emits light having a peak wavelength in the emission spectrum in the range of 590 nm to 620 nm.

(Manufacturing method of light emitting module)
Next, an example of a method for manufacturing a light emitting module according to the present embodiment will be described. First, one or a plurality of LED chips that emit near-ultraviolet rays or short-wavelength visible light are mounted on a substrate made of alumina, aluminum, glass-reinforced epoxy resin, or the like having a circuit pattern formed in advance. The mounting method includes a method of packaging the LED chip in advance and then solder mounting, a chip-on-board mounting method in which the LED chip is die-bonded to the substrate with a die-bonding material and then bonded to a gold wire.

Immediately above each mounted LED chip, a silicone resin containing a phosphor that absorbs light emitted from the LED chip and converts it into green light and a phosphor that also converts light into red light is mounted.

To mount the silicone resin as the first layer, (1) the phosphor-containing silicone resin is molded into a sheet in advance and the silicone resin is adhered to the substrate, or (2) the above-mentioned phosphor-containing silicone is used as an LED chip. It is carried out by applying a fixed amount of drops on top and then curing. In this case, the resin in contact with the LED chip (adhesion of (1), dripping of (2)) has a storage elastic modulus of 10 ⁴ to 10 ⁵ Pa at at least any temperature included in the range of -40 to 100 ° C. A resin having a low elastic modulus is preferable.

Next, a silicone resin (second layer) in which a blue phosphor or a yellow phosphor is dispersed is mounted. In particular,
(1) A silicone resin in which a blue phosphor or a yellow phosphor is dispersed is applied onto a substrate on which the above-mentioned first layer is mounted so as to have an appropriate thickness in the range of 3 to 15 mm, and at 150 ° C. for 1 h. Heat cure.
(2) A silicone resin in which a blue phosphor or a yellow phosphor is dispersed is filled in a mold, and a substrate on which the above-mentioned first layer is mounted is placed in the opening of the mold and cured by heating.
(3) A silicone resin in which a blue phosphor or a yellow phosphor is dispersed is filled in a mold and cured by heating. Then, the cured molded product is bonded to the substrate on which the above-mentioned first layer is mounted by using a transparent resin.

[Example 1]
FIG. 1 is a cross-sectional view schematically showing an outline of a light emitting module according to the first embodiment. The light emitting module 10 shown in FIG. 1 includes a ceramic substrate 12, an nUV-LED chip 14 mounted on the substrate 12 via a resin, a circuit pattern formed on the substrate 12, and electrodes of the nUV-LED chip 14. A pure gold wire 16 for connecting the above and an optical wavelength conversion layer 18 are provided. The nUV-LED chip 14 is an LED chip that emits short-wavelength visible light having a peak near 405 nm.

The light wavelength conversion layer 18 has a first layer 20 and a second layer 22 provided on the opposite side of the nUV-LED chip 14 with the first layer 20 interposed therebetween. In the first layer 20, the red phosphor 24 and the green phosphor 26 are dispersed in the first resin layer 21. The second layer 22 is obtained by dispersing the yellow phosphor 30 and the blue phosphor 32 in the second resin layer 28.

In Example 1, the red phosphor 24 ((Ca, Sr) SiAlN ₃ ) was added to a relatively soft silicone resin (I) having a storage elastic modulus of 0.4 MPa so that the concentration of the entire phosphor was 1.0 vol%. : Eu ²⁺ ) and green phosphor 26 ((Ba, Sr) ₂ SiO ₄ : Eu ²⁺ ) were mixed at a weight ratio of 3: 1 and dispersed / vacuum defoamed to prepare a silicone resin (I) coating solution. The mixing ratio of the red phosphor 24 and the green phosphor 26 may be appropriately set in the range of red phosphor: green phosphor = 65: 35 to 85:15 (weight ratio).

Next, the silicone resin (I) coating liquid in which the amount of the contained phosphor is adjusted is applied using a dispenser so that the nUV-LED chip 14 and the wire 16 on the substrate 12 are sealed. This protects the wire 16. The coating amount is 0.010 to 0.015 g / chip. Then, it is heat-cured at 150 ° C. for 1 h to form the first layer 20.

Next, a blue phosphor 32 ((Ca, Sr) ₅ (PO) was added to a relatively hard silicone resin (II) having a storage elastic modulus of 5.5 MPa so that the concentration of the entire phosphor was 1.0 vol%. ₄ ) ₃ Cl: Eu ²⁺ ) and yellow phosphor 30 ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 3: 2 and dispersed / vacuum defoamed to make a silicone resin. (II) was prepared. The mixing ratio of the blue phosphor 32 and the yellow phosphor 30 may be appropriately set in the range of blue phosphor: yellow phosphor = 50:50 to 70:30 (weight ratio).

Next, the silicone resin (II) in which the amount of the contained phosphor is adjusted is filled in a mold having a hemispherical cavity of φ10 mm. At this time, vacuum filling may be performed so as not to entrain air. Then, the substrate 12 is placed so as to close the cavity opening surface of the mold filled with the silicone resin (II), and is cured and bonded by heat treatment at 150 ° C. for 1 hour.

FIG. 2 is a diagram showing an example of an excitation spectrum and an emission spectrum of the red phosphor used in the examples. FIG. 3 is a diagram showing an example of an excitation spectrum and an emission spectrum of the green phosphor used in the examples. FIG. 4 is a diagram showing an example of the excitation spectrum and the emission spectrum of the yellow phosphor used in the examples. FIG. 5 is a diagram showing an example of an excitation spectrum and an emission spectrum of the blue phosphor used in the examples.

As shown in FIG. 2, the peak wavelength λp of the emission spectrum L1 of the red phosphor according to Example 1 is in the range of 625 nm to 635 nm. The excitation end wavelength λe of the excitation spectrum L2 is in the range of 530 nm to 540 nm. Here, the excitation end wavelength λe indicates a wavelength at which the decrease in excitation intensity on the long wavelength side in the excitation spectrum L2 begins to decrease sharply. The half-value wavelength λh of the excitation spectrum L2 is in the range of 560 nm to 570 nm. Here, the half-value wavelength λh indicates a wavelength having an intensity Ih of 50% of the peak intensity Imax on the long wavelength side of the excitation spectrum L2.

As shown in FIG. 3, the peak wavelength λp of the emission spectrum L3 of the green phosphor according to Example 1 is in the range of 520 nm to 530 nm. The excitation end wavelength λe of the excitation spectrum L4 is in the range of 450 nm to 460 nm. The half-value wavelength λh of the excitation spectrum L4 is in the range of 470 nm to 480 nm.

As shown in FIG. 4, the peak wavelength λp of the emission spectrum L5 of the yellow phosphor according to Example 1 is in the range of 570 nm to 580 nm. The excitation end wavelength λe of the excitation spectrum L6 is in the range of 410 nm to 420 nm. The half-value wavelength λh of the excitation spectrum L6 is in the range of 435 nm to 445 nm.

As shown in FIG. 5, the peak wavelength λp of the emission spectrum L7 of the blue phosphor according to Example 1 is in the range of 455 nm to 465 nm. The excitation end wavelength λe of the excitation spectrum L8 is in the range of 390 nm to 400 nm. The half-value wavelength λh of the excitation spectrum L8 is in the range of 400 nm to 410 nm.

[Example 2]
FIG. 6 is a side view schematically showing an outline of the light emitting module according to the second embodiment. FIG. 7 is a sectional view taken along the line AA of the light emitting module shown in FIG.

The light emitting module 110 shown in FIG. 6 includes a ceramic substrate 112, a plurality of nUV-LED chips 14 mounted on the substrate 112 via a resin, and a circuit pattern and an nUV-LED chip 14 formed on the substrate 112. A pure gold wire 16 for connecting the electrodes of the above and an optical wavelength conversion layer 118 are provided.

The optical wavelength conversion layer 118 includes a first layer 120, a second layer 122 provided on the opposite side of the nUV-LED chip 14 with the first layer 120 interposed therebetween, and a first layer 120 and a second layer. It has a transparent layer 124 that joins the layer 122. The first layer 120 is a resin layer 21 in which the red phosphor 24 and the green phosphor 126 are dispersed. The second layer 122 is formed by dispersing the yellow phosphor 30 and the blue phosphor 32 in the second resin layer 28. The transparent layer 124 may contain a phosphor used for the first layer 120 and the second layer 122.

In Example 2, the red phosphor 24 ((Ca, Sr) SiAlN ₃ ) was added to a relatively soft silicone resin (I) having a storage elastic modulus of 0.4 MPa so that the concentration of the entire phosphor was 1.0 vol%. : Eu ²⁺ ) and green phosphor 126 (β-sialon) were mixed at a weight ratio of 4: 1 and dispersed / vacuum defoamed to prepare a silicone resin (I) coating solution. The mixing ratio of the red phosphor 24 and the green phosphor 126 may be appropriately set in the range of red phosphor: green phosphor = 65: 35 to 85:15 (weight ratio).

The substrate 112 according to the second embodiment is a ceramic substrate having a length of 200 mm, and 24 nUV-LED chips 14 are mounted on the mounting surface at a pitch of 8 mm. Next, a silicone resin (I) coating liquid in which the amount of the contained phosphor is adjusted is applied using a dispenser so that the nUV-LED chip 14 and the wire 16 on the substrate 112 are sealed. It is heat-cured at 150 ° C. for 1 h to form a first layer 20 having a height of 1 mm, a width of 3 mm, and a length of less than 200 mm. This protects the wire 16.

Next, a blue phosphor 32 ((Ca, Sr) ₅ (PO) was added to a relatively hard silicone resin (II) having a storage elastic modulus of 5.5 MPa so that the concentration of the entire phosphor was 1.0 vol%. ₄ ) ₃ Cl: Eu ²⁺ ) and yellow phosphor 30 ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 1: 1 and dispersed / vacuum defoamed to make a silicone resin. (II) was prepared. The mixing ratio of the blue phosphor 32 and the yellow phosphor 30 may be appropriately set in the range of blue phosphor: yellow phosphor = 50:50 to 90:10 (weight ratio).

Next, the silicone resin (II) in which the amount of the contained phosphor is adjusted is formed into a mold having a cavity having a substantially triangular columnar shape (see FIG. 7) having an opening width of 10 mm, a depth of 8 mm, and a length of 200 mm. Fill. At this time, vacuum filling may be performed so as not to entrain air.

Next, the above-mentioned cavity mold filled with the silicone resin (II) is used as the lower mold, and an upper mold that closes the cavity is prepared. The upper mold has a convex shape with a width of 4 to 8 mm and a height of 1 to 3 mm at the center. After these lower and upper molds are molded, they are placed in a heating furnace and heat-treated at 150 ° C. for 1 hour to cure the silicone resin, and the mold is removed to obtain a phosphor-containing silicone molded product.

Therefore, the silicone molded product has a groove having a width of 4 to 8 mm and a depth of 1 to 3 mm formed on the lower surface thereof. This groove is filled with an adhesive transparent resin (for example, dimethyl silicone resin is preferable) to be a transparent layer 124, and the substrate 112 on which the first layer 20 is formed is laminated on the transparent layer 124. The transparent resin is cured by heat treatment at 150 ° C. for 1 hour to produce a light emitting module 110.

[Comparative Example 1]
Blue phosphor 32 ((Ca, Sr) ₅ (PO ₄ ) ₃ ) so that the concentration of the entire phosphor is 1.0 vol% on a relatively hard silicone resin (II) having a storage elastic modulus of 5.5 MPa. Cl: Eu ²⁺ ) and yellow phosphor 30 ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 1: 1 and dispersed / vacuum defoamed to make a silicone resin (II). It was created.

Next, the silicone resin (II) in which the amount of the contained phosphor is adjusted is filled in a mold having a hemispherical cavity of φ10 mm. At this time, vacuum filling may be performed so as not to entrain air. Then, the substrate 12 is placed so as to close the cavity opening surface of the mold filled with the silicone resin (II), and is cured and bonded by heat treatment at 150 ° C. for 1 hour. The light emitting module according to Comparative Example 1 has almost the same configuration as the light emitting module 10 except that the light emitting module 10 according to the first embodiment does not include the first layer 20.

(Characteristic evaluation)
In the light emitting modules in Example 1, Example 2 and Comparative Example 1 described above, the average color rendering coefficient, the color temperature, and the chromaticity coordinates (cx, cy) were measured. The measurement results are shown in Table 1.

As shown in Table 1, the light emitting module 10 according to the first embodiment realizes light having a color rendering property from neutral white to daylight. Further, the light emitting module 110 according to the second embodiment realizes light having a light bulb color and high color rendering properties. On the other hand, the color rendering property of the light emitting module according to Comparative Example 1 remains at the same level as that of a ceiling light for a general house.

FIG. 8 is a diagram showing an emission spectrum of a light emitting module according to Example 1 and an emission spectrum of a light emitting module according to Comparative Example 1. As shown in FIG. 8, the light emitting module 10 according to the first embodiment has improved intensity in the green and red wavelength regions of the light emitting spectrum as compared with the light emitting module according to the comparative example 1.

FIG. 9 is a diagram showing an emission spectrum of the emission module according to the second embodiment. As shown in FIG. 9, in the light emitting module 110 according to the second embodiment, the intensity of the green and red wavelength regions of the emission spectrum is larger than the intensity of the yellow and blue wavelength regions, and the color rendering property is high and the light emitting module 110 is warm. It can be seen that a certain light bulb color is realized.

As described above, in the light emitting modules according to the first and second embodiments, the red phosphor and the green phosphor having the excitation spectrum up to the relatively long wavelength side are contained in the first layer 20 close to the nUV-LED chip. Therefore, the yellow light and blue light excited by the second layer are suppressed from being absorbed by the first layer, and the color shift and the decrease in the light beam are reduced.

The first layer may contain a red phosphor, and the second layer may contain a green phosphor, a yellow phosphor, and a blue phosphor. As a result, since the red phosphor having the excitation spectrum up to the relatively long wavelength side is included in the first layer close to the light emitting element, the yellow light and blue light excited in the second layer are the first. Reabsorption by the layer is suppressed, and color shift and reduction of light beam are reduced.

[Example 3]
The green fluorescent substance 26 ((Ba, Sr) ₂ SiO ₄ : Eu ²⁺ ) used in Example 1 is an orthosilicate-based fluorescent substance, and is an acid nitride such as the green fluorescent substance 126 used in Example 2. The cost is lower than that of the β-SiAlON-based phosphor. On the other hand, orthosilicate-based phosphors are ionic crystalline crystals, easily hydrated, and have low durability, and are therefore strongly affected by heat and light energy. Therefore, the green phosphor may deteriorate (decrease in emission intensity) even when it is lit at room temperature. In particular, when it is arranged in the first layer 20 closest to the nUV-LED chip 14 as in the green phosphor 26 shown in Example 1, it is more strongly affected by heat and light energy.

Therefore, the green phosphor 26 according to Example 3 is contained not in the first layer near the nUV-LED chip 14 but in the second layer farther from the first layer. In addition to the orthosilicate-based green phosphor, it is clear that the configuration shown in Example 3 is effective from the viewpoint of preventing deterioration as long as it is a green phosphor that is easily affected by heat and light energy.

FIG. 10 is a cross-sectional view schematically showing an outline of the light emitting module according to the third embodiment. The light emitting module 210 shown in FIG. 10 includes a ceramic substrate 112, a plurality of nUV-LED chips 114 mounted on the substrate 112 via a resin, a circuit pattern formed on the substrate 112, and an nUV-LED chip 14. A pure gold wire (not shown) for connecting the electrodes of the above and an optical wavelength conversion layer 218 are provided.

The light wavelength conversion layer 218 has a first layer 220 and a second layer 222 provided on the opposite side of the nUV-LED chip 14 with the first layer 220 interposed therebetween. The first layer 220 is a resin layer 221 in which the red phosphor 24 and the first yellow phosphor 30a are dispersed. The second layer 222 is obtained by dispersing the green phosphor 26, the second yellow phosphor 30b, and the blue phosphor 32 in the second resin layer 228.

Here, the first yellow phosphor 30a and the second yellow phosphor 30b may be the same type of phosphor, or may be different types of phosphors. Here, different types of phosphors include not only cases where the types of elements contained in the phosphors are different, but also cases where the types of elements contained are the same but the composition ratios are different.

In Example 3, the red phosphor 24 (Ca _1-x AlSiN ₃ : Eu ²⁺⁾ is formed on the first resin layer 221 such as a silicone resin so that the concentration of the entire phosphor is 0.2 to 1.5 vol%. _x ) and the first yellow phosphor 30a ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 80:20.

Then, a silicone resin coating liquid mixed with a phosphor is applied using a dispenser so that the nUV-LED chip 14 and the like on the substrate 112 are sealed, and heat-cured at 150 ° C. for 1 h to obtain the first. Layer 220 is formed.

Next, the addition polymerization type silicone resin (MS-1002 (A / B) manufactured by Toray Dow Corning Co., Ltd.) was mixed with the blue phosphor 32 ((Ca) so that the concentration of the entire phosphor was 0.5 to 5 vol%. , Sr) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ ), second yellow phosphor 30b ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ), green phosphor 26 ((Ba, Sr) ) ₂ SiO ₄ : Eu) was mixed at a weight ratio of 60:30:10. At that time, it is thoroughly mixed with a self-revolving stirring demethod mixing device.

After that, the mixture is poured into an aluminum cutting die to form a second layer 222, and a substrate 112 on which the nUV-LED chip 14 is sealed by the first layer 220 is placed on the second layer, and the whole is placed. Was heat-cured to prepare a white light emitting module 210.

A room temperature lighting test (If = 160 mA) was performed using this light emitting module 210, and the light emission spectra at the initial stage and after 200 hours were compared. FIG. 11 is a diagram showing changes in the emission spectrum in the emission module according to the third embodiment. As shown in FIG. 11, the light emitting module 210 has almost no change in the light emitting spectrum even when the lighting time is increased. In the evaluation at this time, the light emitting module 210 was energized at 100 mA, and the light emitting characteristics of the emitted light were evaluated by a spectrum measuring device (CAS140B) manufactured by Instrument Systems.

Although the present invention has been described above with reference to the above-described embodiments and examples, the present invention is not limited to the above-described embodiments, and the configurations of the embodiments are appropriately combined or substituted. Those are also included in the present invention. Further, it is also possible to appropriately rearrange the combination and the order of processing in the embodiment based on the knowledge of those skilled in the art, and to add modifications such as various design changes to the embodiment, and such modifications are added. Such embodiments may also be included in the scope of the present invention.

10 Light emitting module, 12 substrate, 14 nUV-LED chip, 16 wire, 18 light wavelength conversion layer, 20 first layer, 21 first resin layer, 22 second layer, 24 red phosphor, 26 green phosphor , 28 Second Resin Layer, 30 Yellow Fluorescent, 32 Blue Fluorescent, 110 Light Emitting Module, 112 Substrate, 118 Light Wavelength Conversion Layer, 120 First Layer, 122 Second Layer, 124 Transparent Layer, 126 Green Fluorescent body.

Claims (5)

A light emitting element that emits ultraviolet rays or short-wavelength visible light,
A light wavelength conversion layer that is excited by the light emitted by the light emitting element and emits visible light is provided.
The light wavelength conversion layer is
It has a first layer and a second layer provided on the side opposite to the light emitting element with the first layer interposed therebetween .
Before SL first layer may include a red phosphor, a first yellow phosphor, a,
The second layer may include a green phosphor, a blue phosphor, and a second yellow phosphor, a,
The first yellow fluorescent substance and the second yellow fluorescent substance are
The general formula is (M ² _x , M ³ _y , M ⁴ _z ) _m M ¹ O ₃ X _{(2 / n)} (where M ¹ is at least selected from the group consisting of Si, Ge, Ti, Zr and Sn. One or more elements containing Si, M ² is selected from the group consisting of Ca, Mg, Ba and Zn One or more elements containing at least Ca, M ³ is selected from the group consisting of Sr, Mg, Ba and Zn. one or more elements including at least Sr is, X is represents one or more elements including at least Eu ²⁺ at least one halogen element, M ⁴ is selected from the group consisting of rare earth elements and Mn. Further, m is 0.11 ≦ m ≦ 8/6, n is in the range of 5 ≦ n ≦ 7, and x, y, z are x + y + z = 1, 0 <x <1, 0 <y <1, 0.01. It is a phosphor represented by ≦ z ≦ 0.3).
The first yellow fluorescent substance and the second yellow fluorescent substance are
The peak wavelength of the emission spectrum is in the range of 570 nm to 580 nm .
The half-wavelength of the excitation spectrum is in the range of 435 nm to 445 nm.
The blue phosphor is
A light emitting module characterized in that the peak wavelength of the emission spectrum is longer than the half-value wavelength of the first yellow phosphor and the half-value wavelength of the second yellow phosphor . The substrate on which the light emitting element is mounted and
Further provided with a lead wire for electrically connecting the light emitting element and the substrate.
The first layer has a first resin layer having an elastic modulus of 10 ⁴ to 10 ⁵ Pa at at least any temperature included in the range of −40 to 100 ° C.
The light emitting module according to claim 1, wherein the first resin layer is provided so as to seal the lead wire. The second layer, the light emitting module according to claim 1 or 2 tio A A hardness and having a second resin layer of 30 to 80. In the first layer, the concentration of the entire phosphor is 0.2 vol% or more and 1.5 vol% or less.
The light emitting module according to any one of claims 1 to 3, wherein the second layer has a concentration of 0.6 vol% or more and 2.0 vol% or less as a whole. The light emitting module according to any one of claims 1 to 4, wherein light having an average color rendering index Ra of more than 85 is emitted.