KR102512806B1 - Light emitting device and preparation method thereof - Google Patents

Abstract

An embodiment of the present invention includes a hybrid type wavelength conversion member including a first wavelength conversion member in which a first phosphor powder is dispersed in a glass matrix and a second wavelength conversion member in which a second phosphor powder is dispersed in a resin. , It is possible to realize not only various colors, but also uniform wavelength conversion and improve optical characteristics and reliability.

Description

Light emitting device and manufacturing method of the light emitting device {LIGHT EMITTING DEVICE AND PREPARATION METHOD THEREOF}

The present invention relates to a light emitting device and a method for manufacturing the light emitting device, and more particularly, to a light emitting device including two or more types of wavelength conversion members and a method for manufacturing the same.

Existing display devices or light emitting devices used for lighting purposes emit light using blue light emitting diodes (hereinafter referred to as LEDs) or near-ultraviolet LEDs based on gallium nitride-based compound semiconductors of visible light sources. device can be used.

Such a light emitting device can obtain white or other visible light emission by using a phosphor material that absorbs part or all of the light emitted by the LED as excitation light and converts the wavelength from visible light having a longer wavelength.

Among them, a light emitting device using white light emission is recently used in various ways such as various indicators, light sources, display devices, and backlights of liquid crystal displays, and is used for various purposes such as automobile headlamps and general lighting.

Generally, a light emitting device includes a wavelength conversion member in which phosphor powder is dispersed in an organic or inorganic matrix.

Specifically, Japanese Patent Laid-open Publication No. 2018-31829 discloses a method for manufacturing a wavelength conversion member in which phosphor powder is dispersed in a glass matrix. However, some phosphors deteriorate at the sintering temperature of the wavelength conversion member using a glass matrix, resulting in deterioration in optical properties and discoloration, which limits the use of phosphors, making it impossible to produce a wavelength conversion member with high color rendering.

In order to solve this problem, a light emitting device including a wavelength conversion member in which phosphor powder is dispersed in a silicon matrix has been studied, but there are problems in that mechanical properties are deteriorated and luminance of the light emitting device is low.

In particular, when using a wavelength conversion member in which manganese-activated fluoride-based phosphor powder is dispersed as a red phosphor powder in a silicon matrix, it is vulnerable to moisture, thereby deteriorating optical properties, resulting in low reliability.

To solve this problem, a light emitting device in which a glass protective layer is disposed on a wavelength conversion member has been studied. However, there is a problem in that optical properties deteriorate because blue or green light does not pass through the glass protective layer smoothly, and there are still limitations in improving various color implementation, optical properties, and high reliability at the same time.

Japanese Laid-open Patent No. 2018-31829

The present invention was devised to solve the problems of the prior art, and the technical problem to be solved by the present invention is to provide a light emitting device capable of uniform wavelength conversion and improving optical characteristics and reliability as well as implementing various colors. is to do

Another technical problem to be solved by the present invention is to provide a manufacturing method of the light emitting device.

In order to achieve the above object, one embodiment of the present invention is a light emitting device; at least one or more layers of first wavelength conversion members in which a first phosphor powder is dispersed in a glass matrix; and at least one or more layers of second wavelength conversion members in which second phosphor powder is dispersed in resin between the light emitting element and the first wavelength conversion member.

Another embodiment includes preparing a first wavelength conversion member of at least one layer including a glass matrix and a first phosphor powder; preparing a second wavelength conversion member of at least one layer including a resin and a second phosphor powder; manufacturing a wavelength conversion member layer by bonding the first wavelength conversion member and the second wavelength conversion member; and arranging a second wavelength conversion member in the wavelength conversion member layer so that one surface faces the light emitting element.

The light emitting device according to the above embodiment includes a hybrid type wavelength conversion member including a first wavelength conversion member in which a first phosphor powder is dispersed in a glass matrix and a second wavelength conversion member in which a second phosphor powder is dispersed in a resin. By including it, not only various color implementations but also uniform wavelength conversion is possible and optical characteristics and reliability can be improved.

Hereinafter, the present invention will be described in more detail through the accompanying drawings.
1 is a side cross-sectional view of a light emitting device according to an embodiment of the present invention.
2 is a side cross-sectional view of a light emitting device according to another embodiment of the present invention.

The present invention is not limited to the contents disclosed below, and may be modified in various forms as long as the gist of the invention is not changed.

"Including" in this specification means that it may further include other components unless otherwise specified.

In addition, it should be understood that all numbers and expressions representing amounts of components, reaction conditions, etc. described in this specification are modified by the term "about" in all cases unless otherwise specified.

Further, in this specification, when a part such as a layer or film is said to be “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where another part is present in the middle.

[light emitting device]

Hereinafter, with reference to FIGS. 1 and 2, the light emitting device of the present invention will be described in detail.

1 and 2, a light emitting device 100 according to an embodiment of the present invention includes a light emitting element 110; at least one or more first wavelength conversion members 130 in which the first phosphor powder 160 is dispersed in the glass matrix 140; and at least one layer of second wavelength conversion members 120 in which second phosphor powder 170 is dispersed in resin 150 between the light emitting element 110 and the first wavelength conversion member 130. . The light emitting device 110 may include a substrate 190 and a light emitting diode (LED) chip 180 disposed on the substrate 190 .

Specifically, the light emitting device 100 according to an embodiment of the present invention, as shown in Figure 1, the light emitting element 110; a first wavelength conversion member 130; and a second wavelength conversion member 120 between the light emitting element 110 and the first wavelength conversion member 130, wherein the light emitting element 110, the second wavelength conversion member 120, and the first wavelength conversion member 130 may have a sequentially stacked structure. In this case, the problem of deterioration of the phosphor can be minimized, and a stable light emitting device can be provided. For example, the second wavelength conversion member 120 including the resin 150 and the second phosphor powder 170 is disposed on one surface of the light emitting element 110, specifically, in the light emitting element 110. It may be disposed so as to be in contact with the upper surface of the LED chip 180 as a whole.

In particular, due to a specific structure in which the second wavelength conversion member 120 including the resin is laminated between the light emitting element 110 and the first wavelength conversion member 130, scattering of light can be minimized, The luminous efficiency can be further improved.

As shown in Figure 2, the light emitting device 100 according to another embodiment of the present invention, the light emitting element 110; a first wavelength conversion member 130; and a second wavelength conversion member 120 between the light emitting element 110 and the first wavelength conversion member 130, wherein the light emitting element 110 and the second wavelength conversion member 120 may exist in isolation.

Specifically, an empty space 125 may exist between the light emitting element 110 and the second wavelength conversion member 120 . The empty space 125 may be formed using, for example, a barrier rib.

For example, after molding the polymer resin-based barrier rib through a mold, a light emitting device 110 including a substrate 190 and a light emitting diode (LED) chip 180 is inserted into the lower portion of the barrier rib, An empty space 125 is formed between the light emitting element 110 and the second wavelength conversion member 120 by sequentially disposing the second wavelength conversion member 120 and the first wavelength conversion member 130 on the top. can form

In addition, after disposing a polymer resin-based barrier rib on the light emitting element 110, by sequentially disposing the second wavelength conversion member 120 and the first wavelength conversion member 130 on the barrier rib, An empty space 125 may be formed between the light emitting element 110 and the second wavelength conversion member 120 .

At this time, the thickness of the empty space 125 between the light emitting element 110 and the second wavelength conversion member 120, that is, the distance between the light emitting element 110 and the second wavelength conversion member 120 is, for example, 0.5 mm to 5 mm. In addition, in order to secure the empty space, a conventional polymer resin-based barrier rib material and structure used in a light emitting device may be employed.

When the light emitting device includes only the first wavelength conversion member, it may be difficult to implement red light having sufficient luminance, and color rendering index (CRI) cannot be increased. there is

In addition, when the light emitting device includes only the second wavelength conversion member, durability or heat resistance of the wavelength conversion member may deteriorate.

A light emitting device according to an embodiment of the present invention is a hybrid type wavelength conversion device including a first wavelength conversion member in which a first phosphor powder is dispersed in a glass matrix and a second wavelength conversion member in which a second phosphor powder is dispersed in a resin. By including the member, not only various color implementations but also uniform wavelength conversion is possible and optical characteristics and reliability can be improved. In particular, due to a specific structure in which the second wavelength conversion member including the resin is stacked between the light emitting element and the first wavelength conversion member, scattering of light may be minimized and luminous efficiency may be further improved.

In addition, by adjusting the concentration (content) and type of the first phosphor powder and the second phosphor powder included in the first wavelength conversion member and the second wavelength conversion member, the emission color can be easily adjusted.

A total thickness of the first wavelength conversion member and the second wavelength conversion member may be 40 to 1500 μm. Specifically, the total thickness of the first wavelength conversion member and the second wavelength conversion member may be preferably 50 to 1500 μm, more preferably 100 to 1000 μm, and still more preferably 100 to 800 μm.

If the total thickness of the first wavelength conversion member and the second wavelength conversion member is too thick, light scattering or absorption becomes too large, and thus the luminous efficiency of the phosphor may decrease. On the other hand, if the total thickness of the first wavelength conversion member and the second wavelength conversion member is too thin, it may be difficult to obtain sufficient luminous intensity and to realize satisfactory mechanical strength of the wavelength conversion member. In particular, the total thickness of the first wavelength conversion member and the second wavelength conversion member may be controlled so that excitation light and fluorescence are in an appropriate ratio to obtain white light emission.

In addition, the total number of layers of the first wavelength conversion member and the second wavelength conversion member may be preferably 2 to 20 layers, more preferably 2 to 10 layers, and still more preferably 2 to 6 layers.

By easily controlling the total thickness and the number of layers of the wavelength conversion member, it is possible to minimize an imbalance in light emitting characteristics among manufactured LED packages or products.

Hereinafter, the configuration of the light emitting device will be described in detail.

light emitting element

The light emitting element 110 included in the light emitting device 100 according to an embodiment of the present invention may include a substrate 190 and a light emitting diode (LED) chip 180 disposed on the substrate 190. there is.

The substrate 190 may use a printed circuit board (PCB). The substrate 190 may use a heat slug type PCB in which a chip mounting area is made of a metal material in consideration of heat dissipation characteristics.

A plurality of lead frames (not shown) are formed on the substrate 190, and a reflective material may be coated in areas other than the bonding area and the LED chip mounting area of the lead frame. In this case, light efficiency can be improved.

Meanwhile, the LED chip 180 may be fixed on the substrate 190 using an adhesive member (not shown), and may be electrically connected to the lead frame of the substrate using a wire.

The wavelength range of the light emitted from the LED chip may be an ultraviolet wavelength range, a blue wavelength range, or a green wavelength range, and the ultraviolet, blue and green wavelength ranges, or blue and green wavelength ranges in which these wavelength ranges are widely distributed, Or it may be in the ultraviolet and blue wavelength regions. The LED chip may be shaped to provide white light as final light.

According to an embodiment of the present invention, the LED chip may be a UV or blue LED chip having a peak wavelength of 380 nm to 500 nm.

First wavelength conversion member

The first wavelength conversion member included in the light emitting device according to an embodiment of the present invention has a structure in which first phosphor powder is dispersed in a glass matrix, which is an inorganic material, and may have at least one layer.

Specifically, the first wavelength conversion member may have a structure in which the first phosphor powder and the glass matrix are almost uniformly mixed.

For example, the structure of the first wavelength conversion member may be a sea-island structure in which one of the first phosphor powder and the glass matrix is dispersed in an island shape within the other. In this case, it is preferable because uniform wavelength conversion can be performed in the first wavelength conversion member. It may have a structure in which the first phosphor powder and the glass matrix are almost uniformly mixed.

Specifically, it may be a structure in which the first phosphor powder is dispersed in a glass matrix in an island shape. In addition, the glass matrix may have a structure in which the glass matrix is dispersed in the first phosphor powder in an island shape.

In addition, for uniform wavelength conversion, in the island-in-the-sea structure, the diameter of an island may be, for example, 1 to 50 μm, preferably 1 to 20 μm. At this time, the diameter of the island means the particle diameter of the first phosphor powder in the shape of an island.

According to an embodiment of the present invention, since the first wavelength conversion member has high hardness and low water permeability, a covering member may not be used.

The hardness of the first wavelength conversion member may be 400 HV to 800 HV when measuring Vickers hardness (MVK H2000).

Also, the first wavelength conversion member may have a lower moisture transmittance than the second wavelength conversion member. When the first wavelength conversion member and the second wavelength conversion member are bonded and used according to an embodiment of the present invention, the first wavelength conversion member can protect the second wavelength conversion member by preventing moisture penetration from the outside, As a result, excellent reliability can be achieved under high temperature and high humidity at 125 ° C., 0.14 MPa, and 100% humidity using PCT (Pressure Cooking Tester) autoclave equipment. Therefore, it is possible not to use a generally used covering member to prevent moisture permeation.

Meanwhile, according to an embodiment of the present invention, the thickness of the first wavelength conversion member may be controlled in order to minimize an imbalance in light emitting characteristics among manufactured LED packages or products.

The thickness of the first wavelength conversion member may be preferably 30 to 500 μm. The thickness of the first wavelength conversion member may be more preferably 50 to 450 μm or more preferably 100 to 400 μm. When the thickness of the first wavelength conversion member satisfies the above range, a desired chromaticity may be implemented.

If the thickness of the first wavelength conversion member is too thick, light scattering or absorption in the first wavelength conversion member may be too large, and thus luminous efficiency may decrease. In addition, if the thickness of the first wavelength conversion member is too thin, sufficient luminous intensity cannot be obtained and it may be difficult to implement satisfactory mechanical strength.

Since the first wavelength conversion member has less internal scattering, a ratio of wavelength conversion of light from the light emitting element tends to be lower than that of the second wavelength conversion member. Therefore, in order to perform sufficient wavelength conversion by the first wavelength conversion member, it may be desirable to make the first wavelength conversion member thick to some extent. Specifically, the thickness of the first wavelength conversion member may be greater than that of the second wavelength conversion member. For example, the thickness ratio of the first wavelength conversion member and the thickness of the second wavelength conversion member may be 1:0.3 to 0.99, 1:0.5 to 0.9, or 1:0.6 to 0.9.

For the reasons described above, it is preferable that the concentration of the first phosphor powder in the first wavelength conversion member is higher than the concentration of the second phosphor powder in the second wavelength conversion member. Here, concentrations of the first phosphor powder and the second phosphor powder in the first wavelength conversion member and the second wavelength conversion member may be weights of the first and second phosphor powders per unit volume.

Also, the number of layers of the first wavelength conversion member may be 1 to 10 layers, 1 to 5 layers, or 1 to 3 layers.

The first wavelength conversion member mainly converts the wavelength of light emitted from the lower surface of the light emitting device, and at the same time, it may serve as a protective layer on the wavelength conversion member to block moisture from entering from the outside. Specifically, since the second wavelength conversion member is disposed under the first wavelength conversion member, the first wavelength conversion member protects the second wavelength conversion member from moisture, so that various colors can be implemented and high reliability can be obtained.

<Glass Matrix>

According to an embodiment of the present invention, the glass matrix included in the first wavelength conversion member includes glass powder, and the glass powder is P ₂ O ₅ , ZnO, SiO ₂ , B ₂ O ₃ , SnO ₂ , and Al. ₂ O ₃ may be included.

Specifically, the P ₂ O ₅ is a component that forms a glass skeleton and improves water resistance, and the content of P ₂ O ₅ is 0.5 to 15 mol%, 2 to 10 mol%, or 3 to 10 mol% based on the total number of moles of the glass powder. 10 mol %.

If the content of P ₂ O ₅ is less than 0.5 mol%, it may be difficult to vitrify, and if it exceeds 15 mol%, the thermal characteristic temperature tends to rise, so that the first wavelength conversion member including glass is sintered at a low temperature. You may have difficulty doing this.

The ZnO is a component that increases the freedom of the composition of the glass powder and lowers the glass transition temperature by increasing the refractive index, and the content of ZnO is 20 to 50 mol%, 25 to 45 mol%, or 30 to 40 mol%.

If the content of ZnO is less than 20 mol%, the softening temperature is high and the effect of lowering the melting point is insignificant, so it may be difficult to secure water resistance and heat resistance. can increase

The SiO ₂ is a component constituting the glass skeleton, and the content of the SiO ₂ is based on the total number of moles of the glass powder, 8 to 40 mol%, 10 to 30 mol% or 12 to 28 mol%,

If the content of SiO ₂ is less than 8 mol%, the structure of the glass may become unstable and may easily crystallize, and if it exceeds 40 mol%, the refractive index may be lowered and the glass transition temperature may be increased.

The B ₂ O ₃ is a component constituting the glass skeleton, and the content of the B ₂ O ₃ may be 10 to 30 mol%, 10 to 25 mol%, or 12 to 22 mol% based on the total number of moles of the glass powder. .

If the content of B ₂ O ₃ is less than 10 mol%, the structure of the glass may become unstable and may easily crystallize, and if it exceeds 30 mol%, the refractive index may be lowered and the glass transition temperature may be increased. .

The SnO ₂ is a component capable of forming a glass skeleton and lowering the temperature of thermophysical properties such as a glass transition temperature, a yield point, and a softening point, and the content of the SnO ₂ is preferably 0.05 based on the total number of moles of the glass powder. to 10 mol%, more preferably 0.05 to 8 mol%, more preferably 0.1 to 6 mol%.

If the SnO ₂ content is too small, such as less than 0.05 mol%, the thermophysical temperature may increase. As a result, it is difficult to sinter the wavelength conversion material containing the glass of the present invention at a low temperature, and the phosphor powder may easily deteriorate. On the other hand, when the content of SnO ₂ exceeds 10 mol%, devitrification (in particular, tetravalent tin) due to Sn is precipitated in the glass during melting, and the transmittance tends to decrease , as a result, it may be difficult to obtain a wavelength conversion member having high luminous efficiency, and it may become difficult to vitrify by melting separation.

The Al ₂ O ₃ is a component that improves chemical durability, and the content of the Al ₂ O ₃ may be 1 to 12 mol%, 1 to 10 mol%, or 1 to 5 mol% based on the total number of moles of the glass powder. .

If the Al ₂ O ₃ content is less than 1 mol%, the effect of improving chemical durability may be insignificant, and if the Al ₂ O ₃ content exceeds 12 mol%, the meltability of the glass may tend to deteriorate. there is.

The glass powder may further include at least one selected from BaO, SrO, CaO, K ₂ O, Na ₂ O, and Li ₂ O components.

The BaO is a component that improves the meltability of glass and inhibits the reaction between the glass and the phosphor, and the content of BaO is 0.5 to 8 mol%, 0.5 to 5 mol%, or 1 to 8 mol% based on the total number of moles of the glass powder. 5 mol%.

If the BaO content is less than 0.5 mol%, the effect of inhibiting the reaction with the phosphor powder may decrease, and if the BaO content exceeds 8 mol%, chemical durability may tend to deteriorate.

SrO is a component that improves the meltability of glass, and the content of SrO may be 1 to 8 mol%, 1 to 6 mol%, or 1 to 5 mol% based on the total number of moles of the glass powder.

If the content of SrO is less than 1 mol%, the effect of improving the meltability of the glass may be insignificant, and if it exceeds 8 mol%, chemical durability may be reduced.

CaO is a component that improves the meltability of glass, and the content of CaO may be 1 to 8 mol%, 1 to 6 mol%, or 1 to 5 mol% based on the total number of moles of the glass powder.

If the CaO content is less than 1 mol%, the effect of improving the meltability of the glass may be insignificant, and if the CaO content exceeds 8 mol%, chemical durability may be reduced.

K ₂ O is a component that can slightly lower the thermophysical temperature and improve the luminous efficiency of the wavelength conversion member, and the content of K ₂ O is based on the total number of moles of the glass powder, preferably 1 to 7 mol%, more preferably Preferably it may be 1 to 6 mol%, and even more preferably 1 to 5 mol%.

If the content of K ₂ O is less than 1 mol%, the effect may be insignificant, and if the content of K ₂ O exceeds 7 mol%, the glass becomes unstable and may be difficult to vitrify.

Na ₂ O is a component that lowers the thermophysical temperature and promotes glass powder phase, and the content of Na ₂ O is preferably 1 to 10 mol%, more preferably 3 to 10 mol%, based on the total number of moles of the glass powder. , even more preferably 4 to 8 mol%.

If the content of Na ₂ O is less than 1 mol%, the effect may be insignificant, and if the content of Na ₂ O exceeds 10 mol%, chemical durability may be lowered, and glass phase promotion may be excessively increased, making it difficult to vitrify. can

Li ₂ O is a component that significantly lowers the thermophysical temperature and improves the luminous efficiency of the wavelength conversion member, and the content of Li ₂ O is preferably 1 to 10 mol%, based on the total number of moles of the glass powder, and more It may be preferably 1 to 8 mol%, and even more preferably 1 to 7 mol%.

If the content of Li ₂ O is less than 1 mol%, the effect may be insignificant, and if the content of Li ₂ O exceeds 10 mol%, chemical durability may be lowered, and glass phase promotion may be excessively increased, making it difficult to vitrify. can

According to an embodiment, the glass powder is P ₂ O ₅ , ZnO, SiO ₂ , B ₂ O ₃ , SnO ₂ , Al ₂ O ₃ , BaO, CaO, K ₂ O, Na ₂ O and Li ₂ O can include

According to an embodiment, the glass powder includes P ₂ O ₅ , ZnO, SiO ₂ , B ₂ O ₃ , SnO ₂ , Al ₂ O ₃ , BaO, K ₂ O, Na ₂ O and Li ₂ O. can do.

According to an embodiment, the glass powder includes P ₂ O ₅ , ZnO, SiO ₂ , B ₂ O ₃ , SnO ₂ , Al ₂ O ₃ , CaO, K ₂ O, Na ₂ O and Li ₂ O can do.

According to an embodiment, the glass powder is P ₂ O ₅ , ZnO, SiO ₂ , B ₂ O ₃ , SnO ₂ , Al ₂ O ₃ , BaO, SrO, CaO, K ₂ O, Na ₂ O and Li ₂ O.

The glass powder may have an average particle diameter (D50) of 1 to 10 μm. In addition, the glass powder may have an average particle diameter (D50) of 2 to 8 μm or 3 to 8 μm.

Meanwhile, the glass matrix may be obtained by molding, compressing, and firing the glass powder. Specifically, the glass matrix may be obtained by putting the glass powder into a molding mold, compression molding, and firing at, for example, 500 to 700 °C.

The glass matrix may have a refractive index of 1.4 to 1.7. Specifically, the glass matrix may preferably have a refractive index of 1.45 to 1.65, more preferably 1.45 to 1.60. For this reason, scattering of light by the first phosphor powder in the first wavelength conversion member is reduced, and light glare to the light emitting element can be suppressed. In addition, the glass matrix has a higher hardness than organic materials such as resins and can be processed at high temperatures.

Meanwhile, a difference in refractive index between the glass matrix and the first phosphor powder may be small. In this case, scattering of light by the first phosphor powder in the first wavelength conversion member is small, and light returning to the light emitting element can be suppressed. If the refractive index of the glass powder is too high, the light reflectance of the surface of the first wavelength conversion member increases, so that it may be difficult for the excitation light to be irradiated to the first phosphor powder in the first wavelength conversion member. Accordingly, the difference in refractive index between the glass powder and the first phosphor powder may be 0.3 or less, specifically 0.2 or less or 0.1 or less.

In addition, in the first wavelength conversion member, a difference in refractive index between the glass matrix and the first phosphor powder may be smaller than a difference in refractive index between a resin included in the second wavelength conversion member, for example, a light transmitting resin and the second phosphor powder. . In this case, light scattering by the first wavelength conversion member may be reduced to prevent a decrease in luminous efficiency.

Meanwhile, the glass matrix may have a softening point (Ts) of 400 to 700 °C, specifically 500 to 700 °C or 550 to 650 °C.

The glass matrix may have a glass transition temperature (Tg) of 400 to 700 °C, 400 to 600 °C, or 400 to 550 °C.

The glass matrix may have a glass expansion softening point (Tdsp) of 400 to 650 °C, 400 to 600 °C, or 450 to 550 °C.

In addition, the glass matrix (inorganic material) has superior hardness compared to organic materials such as resins, and may be processed at high temperatures.

<First phosphor powder>

According to an embodiment of the present invention, the first phosphor powder included in the first wavelength conversion member may be uniformly dispersed in the glass matrix. When the first phosphor powder is uniformly dispersed in the glass matrix, a wavelength conversion member having excellent heat resistance may be provided.

According to an embodiment of the present invention, the first phosphor powder included in the first wavelength conversion member is excited in the above wavelength range to emit near-ultraviolet light or visible light in order to be used with a near-ultraviolet LED or a blue LED chip of 350 to 480 nm. A phosphor that emits light can be used.

Specifically, the first phosphor powder may include at least one selected from blue, green, and yellow light emitting particles.

The first phosphor powder may be a phosphor powder having a visible light wavelength range, for example, a light emission wavelength range of 380 nm to 780 nm.

The blue light-emitting particles include a phosphor powder having an emission wavelength range of 420 nm to 480 nm, the green light-emitting particles include a phosphor powder having an emission wavelength range of 500 nm to 570 nm, and the yellow light-emitting particles include a phosphor powder having an emission wavelength range of more than 570 nm to 590 nm or less, and the red light-emitting particles may include phosphor powder having an emission wavelength range of 610 nm to 750 nm.

The blue light-emitting particles include at least one selected from the group consisting of nitride phosphor powder, oxynitride phosphor powder, oxide phosphor powder, silicon phosphor powder, sulfide phosphor powder, sulfate phosphor powder, halide phosphor powder, and aluminate phosphor powder. can include

Specifically, the blue light-emitting particles include SrMg ₃ Si ₄ O ₁₂ :Eu, Sr ₂ PO ₄ Cl:Eu, (Ca,Sr)Mg ₃ Si ₄ O ₁₂ :Eu, BaMaAl ₁₂ O ₁₇ :Eu and Sr ₅ (PO ₄ ) at least one selected from the group consisting of ₃ Cl:Eu.

The green to yellow light emitting particles are one selected from the group consisting of nitride phosphor powder, oxynitride phosphor powder, oxide phosphor powder, silicon phosphor powder, sulfide phosphor powder, sulfate phosphor powder, halide phosphor powder, and aluminate phosphor powder. may contain more than

Specifically, the green to yellow light-emitting particles are Y ₃ Al ₅ O ₁₂ :Ce (yellow), Lu ₃ Al ₅ O ₁₂ :Ce (green-yellow), Tb ₃ Al ₅ O ₁₂ :Ce (yellow), (Sr ,Ba) ₂ SiO ₄ :Eu(green-yellow), Ca ₈ Mg(SiO ₄ ) ₄ Cl ₂ :Eu,Mn(green), β-SiAlON:Eu(green), (Sr,Ca)Ga ₂ Si ₄ Eu (green), Ca ₃ Sc ₂ Si ₃ O ₁₂ :Ce (green), CaSc ₂ O ₄ :Ce (green), SrSi ₂ O ₂ N ₂ :Eu (green), Sr ₄ Al ₄ O ₂₅ :Eu( cyan) and BaSi ₇ N ₁₀ :Eu (cyan).

In addition, when the emission wavelength of the light emitting element is a short wavelength, the first wavelength conversion member may include two or more types of phosphor powder.

It is also possible to excite and emit light of one type of phosphor by primary light from the light emitting element, and excite and emit light of another type of phosphor by secondary light emitted by the phosphor. In particular, when two types of phosphors having different chromaticities are used, by adjusting the amount of the two types of phosphors, the chromaticity points of the two types of phosphors and the light emitting element are successively connected on the chromaticity diagram. It is possible to obtain light emission corresponding to an arbitrary chromaticity point within a region to be created.

Further, according to an embodiment of the present invention, a white LED is obtained by combining a blue light emitting element or a near-ultraviolet light emitting element and the phosphor powder, but its color tone can be arbitrarily adjusted by the combination of the light emitting element and the phosphor powder.

In addition, a green LED may be obtained by combining a blue light emitting element other than white with green light emitting particles of phosphor powder, or a pastel color may be implemented by combining other phosphor powders.

According to an embodiment of the present invention, when the light emitting device is a blue light emitting device and a white light emitting device is to be implemented, phosphor particles that are excited in blue and emit broad yellow light may be used.

According to one embodiment of the present invention, the first phosphor powder may include a phosphor having an emission wavelength range of 380 to 780 nm, which is a visible wavelength region. Specifically, the first phosphor powder may include at least one selected from blue, green, and yellow light emitting particles.

For example, the first phosphor powder may include blue light-emitting particles (blue phosphor) having a light emission wavelength range of 420 to 480 nm, green light-emitting particles (green phosphor) having a light emission wavelength range of 500 to 570 nm, greater than 570 nm to It may include at least one selected from among yellow light emitting particles (yellow phosphors) having an emission wavelength range of 590 nm or less. In addition, the first phosphor powder may have, for example, 520 to 560 nm in terms of a color mixing relationship with light from other light sources.

Meanwhile, the first phosphor powder has an average primary particle diameter (DSEM) of 3 to 50 μm obtained from image analysis using a scanning electron microscope (SEM). Specifically, when the particle sizes at which the cumulative volume concentration (%) in the particle size distribution measured by laser diffraction is 10%, 50% and 90% are respectively D10, D50 and D90, the D50 is preferably It may be 3 to 50 μm, more preferably 5 to 30 μm.

In addition, the first phosphor powder may have a span value of 0.5 to 1.5 in Equation 1 below.

[Equation 1]

SPAN = (D90-D10)/D50.

In addition, the first phosphor powder may have a DSPAN value of 0.5 to 2.0 in Equation 2 below.

[Equation 2]

Dispan (DSPAN) = D50/DSEM

In Equation 2 above,

DSEM is the average particle diameter of primary particles of phosphor powder. The average particle diameter of the primary particles of the phosphor powder can be obtained from image analysis using a scanning electron microscope (SEM).

In addition, the content of the first phosphor powder is preferably 5 to 95% by weight, more preferably 5 to 80% by weight, or still more preferably 5 to 95% by weight based on the total weight of the first phosphor powder and the glass powder. 60% by weight.

In this way, by adjusting the content and type of the first phosphor powder, the emission color can be easily controlled.

For example, the content ratio (weight ratio of phosphor powder per unit volume) of the first phosphor powder and the second phosphor powder is 1:0.1 to 1.5, preferably 1:0.2 to 1.4, more preferably 1:0.3 to 1.4.

Meanwhile, the refractive index of the first phosphor powder may be preferably 1.6 to 1.9, more preferably 1.65 to 1.85. Accordingly, the difference in refractive index between the first phosphor powder and the glass powder can be adjusted to be preferably 0.3 or less, more preferably 0.2 or less, and even more preferably 0.1 or less.

Second wavelength conversion member

The second wavelength conversion member included in the light emitting device according to an embodiment of the present invention may have a structure in which second phosphor powder is dispersed in a resin, which is an organic material.

Specifically, the second wavelength conversion member may have a structure in which second phosphor powder is uniformly dispersed in a resin, for example, a light-transmitting resin so that light can be scattered therein.

In addition, the second wavelength conversion member is disposed between the light emitting element and the first wavelength conversion member, and may have at least one layer.

According to an embodiment of the present invention, as shown in FIG. 1, the second wavelength conversion member 120 including the resin 150 and the second phosphor powder 170 is in full contact with the upper surface of the LED chip 180, By being arranged, it is possible to provide a sufficient light conversion effect.

In particular, when the second phosphor powder includes red light emitting particles (eg, manganese-activated fluoride-based phosphor powder), a second wavelength conversion member including red is disposed between the light emitting element and the first wavelength conversion member, Since it is possible to solve the conventional problem of deterioration of optical characteristics due to vulnerability of moisture, it is possible to improve various color implementation, optical characteristics, and high reliability at the same time.

Further, in order to provide a light emitting device with less speckle, it is preferable to form the second wavelength conversion member so that the length through which light passes from the light emitting element is substantially uniform. To this end, according to one embodiment of the present invention, the difference in refractive index between the resin and the second phosphor powder may be 0.3 or more, specifically 0.4 or more. Specifically, the second phosphor powder may have a structure dispersed in a resin having a refractive index difference from the second phosphor powder of 0.3 to 0.5, preferably 0.4 to 0.5.

Meanwhile, according to an embodiment of the present invention, the thickness of the second wavelength conversion member may be controlled in order to minimize an imbalance in light emitting characteristics among manufactured LED packages or products.

The second wavelength conversion member may have a thickness of 5 μm to 700 μm. Specifically, the thickness of the second wavelength conversion member may be 5 to 600 μm or 10 to 500 μm.

Also, the number of layers of the second wavelength conversion member may be 1 to 10 layers, 1 to 5 layers, or 1 to 3 layers.

<Suzy>

According to an embodiment of the present invention, the resin included in the second wavelength conversion member may be a light transmitting resin.

In this specification, "light transmittance" means that the light transmittance in the wavelength of the emission peak is 60% or more, 70% or more, or 80% or more.

The light transmitting resin may include at least one selected from the group consisting of silicone resins, epoxy resins, polycarbonate resins, acrylic resins, urethane resins, and modified resins thereof.

Specifically, the resin is an epoxy resin, modified epoxy resin, silicone resin, modified silicone resin, hybrid silicone resin, polyethylene terephthalate resin, polybutylene terephthalate (PBT), polycyclohexane terephthalate resin, polycarbonate (PC ), acrylic resin, polybutylene terephthalate (PBT) resin, urea resin, bismaleimide triazine (BT) resin, polyurethane resin, polyacetal (POM), a group consisting of fluorine-modified acrylic resin and fluorine-modified urethane resin One or more selected from may be mentioned. The modified epoxy resin may include a silicone-modified epoxy resin, and the modified silicone resin may include an epoxy-modified silicone resin.

On the other hand, the above-mentioned silicone resin has a main chain composed of siloxane bonds (-Si-O-Si-) and an alkyl group (eg, methyl group) or an alkoxyl group (eg, methoxy group) in the silicon atom (Si) of the main chain. A side chain to which an organic group such as a molecule is bonded may be included in the molecule.

Examples of the silicone resin may include at least one selected from the group consisting of an alkyl group-containing silicone resin and an alkoxy group-containing silicone resin.

The silicone resin or a modified resin thereof may be preferable because of its excellent heat resistance and light resistance.

Specifically, examples of the silicone resin include dehydration condensation type silicone resins, addition reaction type silicone resins, peroxide curing type silicone resins, wet curing type silicone resins, and curable silicone resins. Specifically, the silicone resin may be an addition reaction type silicone resin or the like.

The silicone resin may have a kinematic viscosity at 25° C. of, for example, 10 to 30 mm 2 /s. These resins may be used alone or in combination of two or more.

Meanwhile, in the epoxy resin, the epoxy equivalent may be, for example, 100 to 1200 g/eq. In addition, the viscosity of the epoxy resin at 25°C may be, for example, 800 to 6000 mPa·s.

On the other hand, the epoxy resin can be prepared as an epoxy resin composition by blending and using a curing agent.

The curing agent may be a latent curing agent (epoxy resin curing agent) capable of curing an epoxy resin by heating, and examples thereof include an imidazole compound, an amine compound, an acid anhydride compound, an amide compound, a hydrazide compound, and an imida compound. sleepy compounds; and the like.

As said imidazole compound, 2-phenyl imidazole, 2-methyl imidazole, 2-ethyl- 4-methyl, etc. are mentioned, for example.

Examples of the above amine compound include polyamines such as ethylene diamine, propylene diamine, diethylene triamine and triethylene tetramine, or amine adducts thereof, such as metaphenylene diamine and diamine. mino diphenyl methane and diamino diphenyl sulfone; and the like.

Examples of the acid anhydride compound include phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, methyl nadic anhydride, pyromellitic anhydride (PMDA), dodecenyl succinic anhydride, dichloro succinic anhydride, benzophenone tetracarboxylic anhydride, and chlorentic acid anhydride; and the like.

As said amide compound, dicyandiamide, polyamide, etc. are mentioned, for example.

As said hydrazide compound, adipic acid dihydrazide etc. are mentioned, for example.

Examples of the above imidazoline compounds include methyl imidazoline, 2-ethyl-4-methyl imidazoline, ethyl imidazoline, isopropyl imidazoline, 2,4-dimethyl imidazoline, and phenyl. Midazoline, undecyl imidazoline, heptadecyl imidazoline, 2-phenyl-4-methyl imidazoline, etc. are mentioned.

The curing agent may be used alone or in combination of two or more.

The content of the curing agent may vary depending on the equivalent ratio of the curing agent and the epoxy resin, but may be, for example, 1 to 80 parts by weight based on 100 parts by weight of the epoxy resin.

<Second phosphor powder>

According to an embodiment of the present invention, the second phosphor powder included in the second wavelength conversion member may be uniformly dispersed in the resin. When the second phosphor powder is uniformly dispersed in the resin, a wavelength conversion member having excellent heat resistance can be obtained.

According to an embodiment of the present invention, the second phosphor powder included in the second wavelength conversion member may be a phosphor powder having a visible light range, for example, a light emission wavelength range of 380 nm to 780 nm.

Specifically, the second phosphor powder may include at least one selected from red, blue, green, and yellow light emitting particles. In addition, the second phosphor powder may include red light emitting particles, and in this case, red light emission with high luminance may be implemented, CRI may be increased, and satisfactory durability and reliability may be implemented.

In addition, the second phosphor powder may include red, green, or yellow light-emitting particles and mixed light-emitting particles of red light-emitting particles.

The red light-emitting particles are phosphor powders having an emission wavelength range of 610 to 750 nm, and include nitride phosphor powder, oxynitride phosphor powder, oxide phosphor powder, silicon phosphor powder, sulfide phosphor powder, sulfate phosphor powder, halide phosphor powder, and It may include at least one selected from the group consisting of aluminate phosphor powder.

Specifically, the red light emitting particles are (Sr,Ca)AlSiN ₃ :Eu, K ₂ SiF ₆ :Mn, K ₂ TiF ₆ :Mn, BaTiF ₆ :Mn, K ₃ ZrF ₇ :Mn, (Sr,Ba) ₂ At least one selected from the group consisting of Si ₅ N ₈ :Eu, (Sr,Ca)S:Eu, α-SiAlON:Eu, and Sr ₃ SiO:Eu may be included.

The blue, green, and yellow light emitting particles may use the same phosphor as the first phosphor powder.

Meanwhile, the second phosphor powder has an average primary particle diameter of 3 to 50 μm obtained from image analysis using a scanning electron microscope (SEM). Specifically, when the particle sizes at which the cumulative volume concentration (%) in the particle size distribution measured by laser diffraction is 10%, 50%, and 90% are D10, D50, and D90, respectively, the D50 is 3 to 50 μm, preferably 5 or 30 μm.

In addition, the second phosphor powder may have a span value of 0.5 to 1.5 in Equation 1.

In addition, the second phosphor powder may have a DSPAN value of 0.5 to 2.0 in Equation 2.

Also, the content of the second phosphor powder may be 5 to 75 wt%, 5 to 70 wt%, or 5 to 65 wt% based on the total weight of the resin and the second phosphor powder.

In this way, by adjusting the content and type of the second phosphor powder, the CRI can be improved and the emission color can be easily controlled.

Meanwhile, in the case of the second wavelength conversion member, since the second phosphor powders having different refractive indices are dispersed into the resin, considerable scattering may occur. Therefore, it is preferable to use a phosphor having a high absorption rate so that white color can be obtained even when the amount of the second phosphor powder is small. That is, if the second phosphor powder having a low absorption rate is used, it is necessary to add a higher concentration of the second phosphor powder to obtain white color, and as a result, the scattering center increases, so the total light transmittance may decrease.

adhesive layer

In the light emitting device according to one embodiment of the present invention, an adhesive layer may be included between the first wavelength conversion member and the second wavelength conversion member, between the light emitting element and the second wavelength conversion member, or both.

The adhesive layer may be formed using an adhesive.

The adhesive may use a light-transmitting material. The adhesive may include at least one selected from the group consisting of an epoxy resin, a silicone resin, an organic adhesive, and an inorganic adhesive.

Specifically, in order to form an adhesive layer using an adhesive, at least one adhesive composition selected from the group consisting of an epoxy adhesive composition, a silicone adhesive composition, a urethane adhesive composition, and an acrylic adhesive composition may be used. More specifically, in order to form an adhesive layer using an adhesive, at least one selected from the group consisting of an epoxy adhesive composition and a silicone adhesive composition may be used. Alternatively, an epoxy adhesive composition may be used to form an adhesive layer using an adhesive.

The above epoxy adhesive composition may contain, for example, an epoxy resin and a curing agent.

The epoxy resin may include at least one selected from the group consisting of aliphatic epoxy resins and silicon-modified aliphatic epoxy resins.

The aliphatic epoxy resins include alicyclic epoxy resins such as hydrogenated bisphenol A type epoxy resins and dicyclocyclic epoxy resins; glycidyl ether type epoxy resins such as ethylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether; and at least one selected from the group consisting of nitrogen ring epoxy resins such as triepoxypropyl isocyanurate (triglycidyl isocyanurate) and hydantoin epoxy resin.

In addition, the adhesive layer may include a thermosetting resin and/or a photocurable resin. The thermosetting resin may include a resin that can be cured in a short time, for example, preferably a resin that is thermally cured at 100 °C to 180 °C, more preferably at 110 °C to 140 °C. Among these, a thermosetting type transparent epoxy resin and a thermosetting type silicone resin can be included, and a silicone type resin is preferable from the viewpoint of heat resistance and light resistance.

The silicone resin is not particularly limited as long as it is a silicone resin capable of forming a semi-cured state. For example, a condensation reaction type silicone resin and an addition reaction type silicone resin may be mentioned, and they can form a semi-cured state if the reaction is stopped before the fore-curing reaction is completed. Also, from the viewpoint of reaction control, a two-stage curing type silicone resin having two or more reaction systems is preferable. Specifically, for thermosetting resins containing (1) both terminal silanol-type silicone resins, (2) alkenyl group-containing silicon compounds, (3) organohydrogensiloxanes, (4) condensation catalysts, and (5) hydroxylation catalysts. The composition can be used, through which an adhesive layer made of a semi-cured silicone resin can be obtained at a relatively low temperature.

If necessary, the adhesive composition may be formulated with a solvent or reactive diluent such as carbitol acetate in an appropriate ratio to adjust the viscosity.

To control the viscosity of the epoxy resin adhesive according to the present invention, glycol ether oxirane prepared by reacting difunctional or higher functional glycols with epichlorohydrin may be further included as a reactive diluent. Specific examples of the reactive diluent include ethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and trimethylol. and at least one selected from the group consisting of propane triglycidyl ether and glycerin triglycidyl ether.

The adhesive composition may be applied using, for example, a printing method and a coating method. Specifically, the adhesive composition may be applied using a printing method, and an adhesive layer may be formed after removing the solvent by heating.

The adhesive layer may have a thickness of 0.1 to 10 μm, 0.3 to 5 μm, or 0.5 to 1 μm.

[Method of manufacturing light emitting device]

The present invention may provide a manufacturing method of the light emitting device.

Referring again to FIGS. 1 and 2 , a method of manufacturing a light emitting device according to an embodiment of the present invention includes at least one layer of a first wavelength conversion member 130 including a glass matrix 140 and a first phosphor powder 160 . ) preparing; preparing at least one layer of the second wavelength conversion member 120 including the resin 150 and the second phosphor powder 170; manufacturing a wavelength conversion member layer by bonding the first wavelength conversion member and the second wavelength conversion member; and arranging one surface of the second wavelength conversion member in the wavelength conversion member layer to face the light emitting element 110 .

Specifically, in the method of manufacturing a light emitting device according to an embodiment of the present invention, step 1) includes preparing at least one layer of a first wavelength conversion member including a glass matrix and a first phosphor powder.

Specifically, a slurry including glass powder capable of forming a glass matrix and first phosphor powder may be prepared.

The slurry may include a commonly used light-transmissive resin or solvent.

A green sheet can be formed by applying the prepared slurry on a supporting substrate and relatively moving a doctor blade installed at a predetermined interval from the supporting substrate with respect to the slurry. A plurality of green sheets can be obtained by cutting the produced green sheet. As the support substrate, a resin film such as polyethylene terephthalate can be used, for example.

Then, a green sheet laminate may be formed by thermally compressing the plurality of green sheets together. According to an embodiment of the present invention, for at least two green sheets of a plurality of green sheets, the moving directions of the doctor blades in the process of forming the green sheets (the green sheet forming direction) intersect with each other, A green sheet can be produced.

The total light transmittance of the first wavelength conversion member is preferably 40% or more, more preferably 60% or more, and most preferably 80% or more. According to an embodiment of the present invention, even when the total light transmittance of the first wavelength conversion member is too low, or less than 40%, in the present invention, since emitted light directed backward is efficiently guided in the light extraction direction by the diffusive reflection layer, Light generated from the phosphor is not particularly a big problem. However, with regard to the excitation light from the LED, if the total light transmittance is too low or the diffusivity is strong, there is a concern that the excitation light may be scattered back in the portion where the diffusive reflection layer is not formed. do.

In the method of manufacturing a light emitting device according to an embodiment of the present invention, step 2) includes preparing at least one layer of second wavelength conversion member including resin and second phosphor powder.

The total light transmittance of the second wavelength conversion member is preferably 40% or more, more preferably 60% or more, and still more preferably 80% or more, similarly to the first wavelength conversion member. However, in the case of the second wavelength conversion member, considerable scattering may occur because the second phosphor powder having a different refractive index is dispersed into the resin. Therefore, it is preferable to use a phosphor having a high absorption rate so that white color can be obtained even when the amount of the second phosphor powder is small. That is, if the second phosphor powder having a low absorption rate is used, it is necessary to add a higher concentration of the second phosphor powder to obtain white color, and as a result, the scattering center increases, so the total light transmittance may decrease.

A printing method, a spraying method, a casting method, a spin coating method, a roll coating method, or a sheet forming method may be selected as a method of forming the second wavelength conversion member. Specifically, as a molding method of the second wavelength conversion member, it may be manufactured by performing at least one method selected from a printing method and a spray method.

First, the molding method may include a method of molding by coating a solution in which the second phosphor powder is dispersed in a light-transmissive resin onto a sheet. The sheet may use a separator, for example, a polyethylene terephthalate (PET) sheet subjected to surface exfoliation. In addition, the sheet is cellophane, acetic cellulose, polyethylene (PE), polypropylene (PP), ethylene vinyl acetate, ionomer, polyvinyl chloride (PVC), polystyrene (PS), polycarbonate (PC), polyamide (PA) ), polyvinyl alcohol (PVAC), polyurethane (PU), fluorine resin (PTFE), and at least one selected from the group consisting of acrylic resins may be used.

Specifically, after dispersing the second phosphor powder in a light-transmitting resin or dispersing the second phosphor powder in a light-transmitting resin in an organic solvent, casting it on the surface-exfoliated polyethylene terephthalate (PET) film , can be applied to an appropriate thickness by spin coating or roll coating. In the case of using an organic solvent, it can be formed into a film by drying at a temperature at which the organic solvent can be removed and molded on a sheet. The drying temperature may vary depending on the type of resin or organic solvent used, but may be performed at, for example, 80 to 150 °C, specifically 90 to 150 °C.

The types and content ratios of the second phosphor powder are as described above.

The second wavelength converting member may be heat-pressed by stacking sheets in a plurality of layers. In addition, the second wavelength conversion member may be molded as a single sheet using a transparent adhesive.

When the second wavelength conversion member is laminated in a plurality of layers, a yellow light emitting layer and a red light emitting layer in the second wavelength conversion member are formed by laminating, for example, yellow phosphor powder and red phosphor powder in different sheets as the second phosphor powder. It may be a structure including a light emitting layer together.

In addition, when the second wavelength conversion member is made of a single layer, two or more types of second phosphor powders may be mixed and used in the single layer.

Meanwhile, in the printing method, a resin composition containing the second phosphor powder in which the second phosphor powder and the resin composition are mixed may be applied onto a substrate such as PET.

Meanwhile, a solvent such as toluene may be mixed in an appropriate ratio to the resin composition containing the second phosphor powder to adjust the viscosity, if necessary.

In the printing method, the resin composition containing the second phosphor powder may be printed through a screen by squeezing.

Thereafter, after removing the solvent by drying, if necessary, the second wavelength conversion member may be formed.

The total light transmittance of the second wavelength conversion member may be 60% or more or 80% or more like that of the first wavelength conversion member.

However, in the case of the second wavelength conversion member, considerable scattering may occur because the second phosphor powder having a difference in refractive index is dispersed in the resin. Therefore, it is preferable to use a phosphor powder having a high absorption rate so that white light can be obtained even when a small amount of the second phosphor powder is used. That is, when a phosphor having a low absorptance is used, it is necessary to add a high concentration of phosphor particles to obtain white color, and as a result, scattering increases and the total light transmittance may decrease.

Meanwhile, in the spray method, a slurry may be prepared by mixing the resin and the second phosphor powder in a solvent. In addition, the slurry may contain various additives having functions of arbitrary filling, light diffusion, and coloring within a range that does not impair the effects of the present invention.

The solvent used in the slurry may include a solvent capable of dissolving the resin. For example, one or more mixed solvents selected from the group consisting of aliphatic hydrocarbon-based solvents, aromatic hydrocarbon-based solvents, ketone-based solvents, alcohol-based solvents, and ester-based solvents may be included.

Specifically, n-hexane, n-heptane, toluene, acetone, isopropyl alcohol, dimethyl carbonate, or solvents exhibiting solubility equivalent to these may be used alone or in combination of two or more. Among these, the solvent may include an ester-based solvent, and may specifically include a carbonic ester-based solvent.

The viscosity of the slurry may be 0.01 to 1000 mPa·s, 0.1 to 100 mPa·s, or 0.1 to 10 mPa·s. When the above viscosity range is satisfied, the second phosphor powder can be uniformly adhered on the light emitting device because it is easy to apply to the spray method.

In addition, the viscosity can be adjusted by selecting a suitable solvent and adjusting the amount. The solvent may be used in an amount of, for example, 10 to 200% by weight, 50 to 150% by weight, or 80 to 120% by weight based on the total weight of the resin and the second phosphor.

The concentration of the slurry may be used by mixing the first phosphor powder and the resin in a weight ratio of 5 to 30:1.

In the method of manufacturing a light emitting device according to an embodiment of the present invention, step 3) includes manufacturing a wavelength conversion member layer by bonding the first wavelength conversion member and the second wavelength conversion member.

A first wavelength conversion member may be bonded to the second wavelength conversion member.

Bonding of the first wavelength conversion member and the second wavelength conversion member may be performed using an adhesive. That is, an adhesive layer may be formed between the first wavelength conversion member and the second wavelength conversion member using an adhesive.

The adhesive and the method of forming the adhesive layer are as described above.

In addition, the present invention may not use an adhesive depending on the embodiment. In this case, adhesion without an adhesive may be performed by subjecting the surfaces of the first wavelength conversion member and the second wavelength conversion member to surface treatment by exposing them to normal pressure plasma, followed by laminating adhesion and curing treatment. At this time, the normal pressure plasma may use a conventional method.

In the manufacturing method of the light emitting device according to the embodiment of the present invention, step 4) includes arranging the second wavelength converting member in the wavelength converting member layer so that one surface faces the light emitting element.

One surface of the second wavelength conversion member may entirely contact one surface of the light emitting device.

In addition, the second wavelength conversion member and the light emitting element may be separated from each other.

When the second wavelength conversion member and the light emitting element are spaced apart from each other, an empty space may exist between the light emitting element and the second wavelength conversion member. The empty space may be formed using, for example, a barrier rib.

For example, after molding the polymer resin-based barrier rib through a mold, a light emitting device including a substrate and a light emitting diode chip is inserted into the lower portion of the barrier rib, and the second wavelength conversion member and the first By sequentially disposing the wavelength conversion members, an empty space may be formed between the light emitting element and the second wavelength conversion member.

Bonding of the second wavelength conversion member and the light emitting element may include an adhesive layer between the second wavelength conversion member and the light emitting element by being bonded using the adhesive. .

The adhesive and the method of forming the adhesive layer are as described above.

The present invention will be described in more detail through the following examples. However, the scope of the present invention is not limited to these examples.

[Example]

Preparation of the glass matrix

<Production Example 1>

Each component was mixed to have the composition shown in Table 1 below, and melted at 1200 to 1400 °C to prepare a glass material. The prepared glass material was pulverized to prepare a glass powder having an average particle diameter of 5.9 μm. The prepared glass powder was put into a molding mold, compressed and molded at a pressure of 5 tons for 5 minutes, and then put into a firing furnace and fired at 620° C. for 30 minutes. Thereafter, the mirror surface was abraded to have a surface roughness of 0.2 μm to prepare a glass matrix having a thickness of 200 μm.

<Preparation Examples 2 to 4>

A glass matrix was prepared in the same manner as in Preparation Example 1, except that the content of each component was adjusted to have the composition shown in Table 1 below.

Test Example 1

The physical properties of the glass matrices of Preparation Examples 1 to 4 were evaluated in the following manner, and the results are shown in Table 1.

(1-1) Thermal properties: glass transition temperature (Tg), softening temperature (Ts), expansion softening point temperature (Tdsp)

Using a thermal analyzer (SDT: Q600, TA Instruments, USA), the glass transition temperature, softening temperature, and expansion softening point were measured in the range from room temperature to 1,000 °C at a heating rate of 10 °C/min.

At this time, Tdsp (Temperature dilatometer softening point) means the dilatometer softening point temperature.

(1-2) Light transmittance (%)

The light transmittance of light with a reference wavelength of 550 nm was measured using a Hitachi company's magnetic spectrophotometer (U-350, Japan), and the state without a sample was taken as 100%.

(1-3) Refractive index

The measurement was performed using Professional Gemstone Refractometers (Kruess model ER601 LED, Germany). During measurement, the specimen was processed to a thickness of 1 mm (1T), and then a certain amount of refractory liquid was applied to the specimen measurement position so that it was completely adhered to the measurement part. The refraction gauge value was visually confirmed.

(1-4) average particle diameter (D ₅₀ ) measurement

The particle size was measured using Microtreac's S3500 equipment. D50 of the analysis value was measured as the particle diameter (D50) when the cumulative volume concentration (%) reached 50% in the particle size distribution measurement by the laser light diffraction method.

The results according to Test Example 1 are summarized in Table 1 below.

As shown in Table 1, the glass matrices of Preparation Examples 1 to 4 exhibited high light transmittance and excellent refractive index characteristics, and also exhibited appropriate softening characteristics in thermal characteristics.

Meanwhile, since the light transmittance and refractive index of the glass matrix affect the light characteristics of the light emitting device, light emitting devices including each of the glass matrices were manufactured and their physical properties were confirmed.

Manufacture of Light Emitting Devices

<Example 1>

Step 1): Preparing a first wavelength conversion member of at least one layer including a glass matrix and a first phosphor powder

As shown in Table 2, the glass matrix and the first phosphor powder obtained in Preparation Example 1 were mixed in amounts of 40% by weight and 60% by weight, respectively, and then molded and then sintered to obtain a first wavelength conversion member having a thickness of 200 μm. Got it.

Step 2): preparing at least one layer of second wavelength conversion member including resin and second phosphor powder

Silicone resin (DOW CORNING ^TM OE-7670A/B) and second phosphor powder were mixed in amounts of 80% by weight and 20% by weight, respectively, and then cast-molded to obtain a second wavelength conversion member having a thickness of 100 μm.

Step 3): manufacturing a wavelength conversion member layer by bonding the first wavelength conversion member and the second wavelength conversion member

After disposing the first wavelength conversion member on one surface of the second wavelength conversion member, an adhesive layer was formed using an adhesive.

The adhesive was sprayed onto one surface of the first wavelength conversion member using KCC Corporation's silicone-based primer (SL3111A/B). The silicone-based primer was subjected to temporary curing treatment at 80° C. for 5 minutes, and laminated and bonded to the second wavelength conversion member at 85° C. Thereafter, curing treatment was performed at 150° C. for 2 hours.

Step 4): Disposing a light emitting element on one surface of a second wavelength conversion member in the wavelength conversion member layer.

After disposing the light emitting device so as to entirely contact the other surface of the second wavelength conversion member, a silicon-based primer was sprayed to form an adhesive layer.

At this time, the light emitting device used a light emitting device including an LED chip on a substrate.

<Examples 2 to 4>

As shown in Table 2, a light emitting device was obtained in the same manner as in Example 1 except for changing the composition of the first wavelength conversion member and the second wavelength conversion member and their thickness.

<Example 5>

As shown in Table 2, the composition of the first wavelength conversion member and the second wavelength conversion member and their thickness are changed, and atmospheric pressure plasma is applied to the surfaces of the first wavelength conversion member and the second wavelength conversion member without using an adhesive. A light emitting device was obtained in the same manner as in Example 1, except that surface treatment was performed for 20 seconds, laminating was performed, and curing was performed at 150° C. for 2 hours.

<Comparative Example 1>

As shown in Table 3, a light emitting device was obtained in the same manner as in Example 1, except that only the first wavelength conversion member was used.

<Comparative Example 2>

As shown in Table 3, a light emitting device was obtained in the same manner as in Example 1, except that only the first wavelength conversion member composed of two layers was used.

<Comparative Examples 3 and 4>

As shown in Table 3, a light emitting device was obtained in the same manner as in Example 1, except that only the second wavelength conversion member composed of two layers was used.

On the other hand, in Comparative Example 4, as in Example 5, the second wavelength conversion member was laminated and bonded without using an adhesive.

<Comparative Example 5>

As shown in Table 3, the composition of the first wavelength conversion member and the second wavelength conversion member and their thickness are changed, except that the wavelength conversion member in contact with the LED chip is the first wavelength conversion member, Example 1 A light emitting device was obtained in the same manner as described above.

Test Example 2

The physical properties of the light emitting devices of Examples 1 to 5 and Comparative Examples 1 to 5 were measured in the following manner, respectively, and the results are shown in Tables 2 and 3 below.

(2-1) Optical characteristics (CIEx, CIEy, luminous flux (Φv, lumen (lm)) and color rendering index (Ra))

Chromaticity distribution was measured by placing the light emitting devices of Examples and Comparative Examples on a 445 nm excitation light source using an integrating sphere measuring instrument (LMS-200, J&C Tech.).

(2-2) Reliability test

Reliability was confirmed under high temperature and high humidity at 125 ° C., 0.14 MPa, and 100% humidity using PCT (Pressure Cooking Tester) autoclave equipment.

The results according to Test Example 2 are summarized in Tables 2 and 3 below.

As shown in Tables 2 and 3, it can be seen that the light emitting devices of Examples 1 to 5 according to the embodiment of the present invention generally have better light characteristics than the light emitting devices of Comparative Examples 1 to 5.

Specifically, in the case of the light emitting device in which the light emitting element, the second wavelength conversion member, and the first wavelength conversion member are sequentially stacked as in Examples 1 to 5, the color rendering index (Ra) is 65 or more and the optical properties are excellent, while the comparative As in Examples 1 to 5, when only the first wavelength conversion member is included, when only the second wavelength conversion member is included, and when the structure of the present invention is not included even though the wavelength conversion member of two or more layers is included, Examples 1 to 5 Compared to that, the optical properties were significantly reduced.

In particular, in the case of Comparative Examples 2 and 5 in which the wavelength conversion member bonded to the LED chip was not the second wavelength conversion member of the present invention, even though the wavelength conversion member included two or more layers, the color rendering index (Ra) was remarkably low.

In addition, even when the wavelength conversion member including two or more layers of wavelength conversion members and bonded to the LED chip is the second wavelength conversion member of the present invention, in Comparative Examples 3 and 4 not including the first wavelength conversion member, the light beam (Φv , Lumen (lm) is low, so it can be confirmed that the optical properties are deteriorated.

On the other hand, as a result of the reliability test under high temperature and high humidity, the light emitting devices of Examples 1 to 5 had a luminous flux (Φv, lumen (lm)) of 45 or more, and a significantly increased lm% change rate compared to the light emitting devices of Comparative Examples 1 to 5. Able to know.

100: light emitting device
110: light emitting element
120: second wavelength conversion member
125: empty space
130: first wavelength conversion member
140: glass matrix
150: Resin
160: first phosphor powder
170: second phosphor powder
180: light emitting diode (LED) chip
190: substrate

Claims (21)

light emitting device;
at least one or more layers of first wavelength conversion members in which a first phosphor powder is dispersed in a glass matrix; and
Between the light emitting element and the first wavelength conversion member, at least one or more layers of second wavelength conversion members in which a second phosphor powder is dispersed in a resin are included,
The thickness ratio of the first wavelength conversion member and the thickness of the second wavelength conversion member is 1:0.6 to 0.9,
The difference in refractive index between the glass matrix and the first phosphor powder is smaller than the difference in refractive index between the resin and the second phosphor powder;
The light emitting device, wherein the glass matrix comprises a glass powder having the following composition based on the total number of moles of glass powder:
0.5 to 15 mol% of P ₂ O ₅ ;
20 to 50 mol% ZnO;
SiO ₂ 8 to 40 mol%;
B ₂ O ₃ 10 to 30 mol%;
SnO ₂ 0.05 to 10 mol%;
Al ₂ O ₃ 1 to 12 mol%;
1 to 7 mol% of K ₂ O;
1 to 10 mol% of Na ₂ O, and
Li ₂ O 1 to 10 mol %.
According to claim 1,
The first phosphor powder includes at least one selected from blue, green, and yellow light emitting particles,
The light emitting device, wherein the second phosphor powder includes at least one selected from among red, blue, green and yellow light emitting particles.
According to claim 2,
The light emitting device, wherein the second phosphor powder includes red light emitting particles.
According to claim 2,
The red light-emitting particles include a phosphor having an emission wavelength range of 610 to 750 nm,
The blue light-emitting particles include a phosphor having an emission wavelength range of 420 to 480 nm,
The green light-emitting particles include a phosphor having a light emission wavelength range of 500 to 570 nm,
The light emitting device, wherein the yellow light emitting particles include a phosphor having a light emitting wavelength range of more than 570 nm and less than or equal to 590 nm.
According to claim 1,
The light emitting device, wherein the first wavelength conversion member has a thickness of 30 to 500 μm.
According to claim 1,
The light emitting device, wherein the second wavelength conversion member has a thickness of 5 to 700 μm.
According to claim 1,
The light emitting device, wherein the total thickness of the first wavelength conversion member and the second wavelength conversion member is 40 to 1500 μm.
According to claim 1,
and an adhesive layer between the first wavelength conversion member and the second wavelength conversion member.
According to claim 8,
The light emitting device, wherein the adhesive layer is formed of at least one adhesive composition selected from the group consisting of an epoxy adhesive composition, a silicone adhesive composition, a urethane adhesive composition, and an acrylic adhesive composition.
According to claim 8,
The light emitting device, wherein the adhesive layer has a thickness of 0.1 to 10 μm.
According to claim 1,
The first phosphor powder and the second phosphor powder,
When the particle sizes at which the cumulative volume concentration (%) in the particle size distribution measured by laser diffraction is 10%, 50%, and 90% are D10, D50, and D90, respectively, the D50 is 3 to 50 μm, respectively, ,
A light emitting device having a span value of 0.5 to 1.5 in Equation 1 below:
[Equation 1]
SPAN = (D90-D10)/D50.
delete According to claim 1,
A light emitting device in which the glass powder further comprises at least one selected from the following components:
BaO 0.5 to 8 mol%;
1 to 8 mol% SrO, and
CaO 1 to 8 mol %.
According to claim 1,
The light emitting device, wherein the glass matrix has a refractive index of 1.4 to 1.7 and a softening point (Ts) of 400 to 700 °C.
delete According to claim 1,
The light emitting device, wherein the glass powder has an average particle diameter (D50) of 1 to 10 μm.
According to claim 1,
The light emitting device, wherein the content of the first phosphor powder is 5 to 95% by weight based on the total weight of the first phosphor powder and the glass powder.
According to claim 1,
The light emitting device, wherein the content of the second phosphor powder is 5 to 75% by weight based on the total weight of the second phosphor powder and the resin.
According to claim 1,
The light emitting device, wherein the resin includes at least one selected from the group consisting of silicone resins, epoxy resins, polycarbonate resins, acrylic resins, urethane resins, and modified resins thereof.
preparing at least one layer of first wavelength conversion member including a glass matrix and a first phosphor powder;
preparing a second wavelength conversion member of at least one layer including a resin and a second phosphor powder;
manufacturing a wavelength conversion member layer by bonding the first wavelength conversion member and the second wavelength conversion member; and
arranging a surface of a second wavelength conversion member in the wavelength conversion member layer to face the light emitting element;
including,
The thickness ratio of the first wavelength conversion member and the thickness of the second wavelength conversion member is 1:0.6 to 0.9,
The difference in refractive index between the glass matrix and the first phosphor powder is smaller than the difference in refractive index between the resin and the second phosphor powder;
A method for manufacturing a light emitting device, wherein the glass matrix includes a glass powder having the following composition based on the total number of moles of the glass powder:
0.5 to 15 mol% of P ₂ O ₅ ;
20 to 50 mol% ZnO;
SiO ₂ 8 to 40 mol%;
B ₂ O ₃ 10 to 30 mol%;
SnO ₂ 0.05 to 10 mol%;
Al ₂ O ₃ 1 to 12 mol%;
1 to 7 mol% of K ₂ O;
1 to 10 mol % of Na ₂ O, and
Li ₂ O 1 to 10 mol%.
21. The method of claim 20,
One surface of the second wavelength conversion member entirely contacts one surface of the light emitting element, or
The method of manufacturing a light emitting device, wherein the second wavelength conversion member and the light emitting element exist apart from each other.

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