KR20140015958A

KR20140015958A - Light emitting device package

Info

Publication number: KR20140015958A
Application number: KR1020120082494A
Authority: KR
Inventors: 이치우; 박민정; 박종원; 우나리; 윤창번; 윤철수; 한옥식
Original assignee: 삼성전자주식회사
Priority date: 2012-07-27
Filing date: 2012-07-27
Publication date: 2014-02-07

Abstract

The present invention relates to a light emitting device package, an aspect of the present invention,
A first wavelength conversion portion having a light emitting element, a package body on which the light emitting element is mounted, and a concave portion formed on an upper surface thereof, and a first wavelength conversion material converting the wavelength of light emitted from the light emitting element into light having a first wavelength; And a second wavelength conversion unit formed in the concave portion and having a second wavelength conversion material converting a wavelength of light emitted from the light emitting device into light having a second wavelength.

Description

Light Emitting Device Package

The present invention relates to a light emitting device package.

In general, the phosphor material for wavelength conversion is used as a material for converting specific wavelength light of various light sources into the desired wavelength light. In particular, since light emitting diodes among various light sources can be advantageously applied as LCD backlights, automobile lights, and home lighting devices due to low power driving and excellent light efficiency, phosphor materials have recently been spotlighted as a core technology for manufacturing white light emitting devices.

In particular, many researches and patents on light emitting device packages using quantum dots having color reproducibility and high quantum efficiency have been recently conducted. However, currently, a light emitting device using quantum dots or a light emitting device directly applying quantum dots to silicon has low reliability due to deterioration and disappearance of the quantum dots and thus has many problems in commercialization.

That is, when the phosphor is applied alone, the problem of color nonuniformity, reabsorption of light, and light scattering, which are inherent problems of powder phosphors, still remain. In addition, when the quantum dot is applied, the quantum dot is very vulnerable to oxygen moisture because it is mixed with the organic material, and also the phenomenon that the quantum dot disappears or discolors due to excessive heat generated from the light emitting device chip.

The present invention improves the problems of the quantum dot and the phosphor, and in order to take advantage of the two materials at the same time to produce a cup-shaped phosphor layer containing the quantum dot after blocking oxygen moisture to improve the structure and implement color reproducibility and high brightness white A light emitting device package.

One object of the present invention is to provide a novel light emitting device package having a light emitting area in the entire visible light region and excellent in high brightness, color rendering, and color reproducibility.

One aspect of the present invention to solve the above problems,

A first wavelength conversion portion having a light emitting element, a package body on which the light emitting element is mounted, and a concave portion formed on an upper surface thereof, and a first wavelength conversion material converting the wavelength of light emitted from the light emitting element into light having a first wavelength; And a second wavelength conversion unit formed in the concave portion and having a second wavelength conversion material converting a wavelength of light emitted from the light emitting device into light having a second wavelength.

In one embodiment of the present invention, the first wavelength converting material may include an inorganic phosphor, and the second wavelength converting material may include a quantum dot phosphor.

In this case, it may further include a protective layer formed on the first wavelength conversion portion to seal the recess,

The protective layer may be a glass plate or a light transmissive polymer compound.

In this case, the first wavelength converter may be a ceramic structure made of the inorganic phosphor.

In this case, the first wavelength conversion part may be made of a transparent resin containing the inorganic phosphor.

In this case, the second wavelength converter may be made of a transparent resin containing the quantum dot phosphor.

In this case, the light emitting device may emit blue light, the first wavelength converting material may be a red phosphor, and the second wavelength converting material may be a green phosphor.

In this case, the light emitting device may emit blue light, the first wavelength conversion material may be a green phosphor, and the second wavelength conversion material may be a red phosphor.

In one embodiment of the present invention, the package body includes a cavity providing a mounting area of the light emitting device, the first wavelength conversion portion may be formed to cover the upper surface of the cavity.

In one embodiment of the present invention, the first wavelength conversion portion may be formed in a cup shape.

In one embodiment of the present invention, at least a portion of the first wavelength conversion portion may be formed to correspond to the shape of the inner wall of the cavity may be inserted into the cavity.

In one embodiment of the present invention, the first wavelength conversion portion may be formed spaced apart from the bottom surface of the cavity.

In one embodiment of the present invention, at least one of the first and second wavelength conversion portion may further contain a diffusion material for smooth diffusion of light in addition to the fluorescent material.

In one embodiment of the present invention, the cavity may be a plurality of layer structure with an inner side stepped.

In this case, the cavity may include a third wavelength conversion part formed in at least one of the plurality of layer structures of the cavity and having a different material from the first and second wavelength conversion parts.

According to one embodiment of the present invention, a semiconductor light emitting device and a light emitting device can be obtained by forming a reflective layer between the substrate and the semiconductor layer to increase the light extraction efficiency and at the same time improve the reliability of the device.

In addition, by applying a quantum dot wavelength conversion portion, the half width of the wavelength is narrow and excellent color reproducibility can be utilized. In addition, by using a cup-shaped phosphor layer to lower the temperature received by the quantum dot, by using a spacer to block the oxygen / moisture, it is possible to ensure a stable life of the light emitting device package.

1 is a cross-sectional view schematically showing a light emitting device package according to an embodiment of the present invention.
2 is a cross-sectional view schematically showing a light emitting device package according to an embodiment of the present invention.
3 is a cross-sectional view schematically showing a light emitting device package according to an embodiment of the present invention.
4 is a cross-sectional view schematically showing a light emitting device package according to an embodiment of the present invention.
5 is a graph showing light emitting performance according to time change in the light emitting device package according to the related art.
6 is a graph showing a change in light wavelength with time variation in the light emitting device package according to the prior art.
7 is a graph showing light emitting performance according to time variation in a light emitting device package according to an exemplary embodiment of the present invention.
8 is a graph showing a change in light wavelength with time variation in a light emitting device package according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

1 is a cross-sectional view schematically showing a light emitting device package according to an embodiment of the present invention. Referring to FIG. 1, the light emitting device package according to the present exemplary embodiment includes a light emitting device 11, a package body 12 on which the light emitting device chip is mounted, and an upper portion of the light emitting device 11 and the package body 12. It may be provided in the form including the first and second wavelength converter 13, 14 disposed in the.

Hereinafter, the components of the semiconductor light emitting device according to the present embodiment will be described in detail. However, in this specification, terms such as 'top', 'bottom', and 'side' are based on the drawings and may actually vary depending on the direction in which the device is disposed.

As long as the light emitting element 11 can be used as a light source in the present embodiment, any one can be employed. However, it is preferable to employ a light emitting diode in terms of miniaturization and high efficiency of the light source.

In this case, the light emitting diode is a light source that generates light by applying a voltage, and is mainly used where a white light source is required, such as a backlight unit. A white light emitting diode chip is mainly used as the light emitting diode, but if necessary, a red, green, or blue light emitting diode chip may be collected and configured to selectively emit light of these three colors. In addition, the mixture of the three colors can express white light, and by installing all the LED chips of each color and varying the applied voltage of each chip, the desired specific color can also be expressed.

The package body 12 mainly uses a high heat dissipation ceramic material that can easily dissipate heat generated during operation of the light emitting device 11 due to high thermal conductivity, but the scope of the present invention is not limited thereto. .

That is, the package body 12 is formed of an organic resin material and other organic resin material containing epoxy, triazine, silicon, polyimide and the like, in addition to the above examples, or a ceramic material such as AlN and Al ₂ O ₃ , or a metal and It may be formed using a metal compound or the like.

The package body 12 provides a space in which the light emitting device 11 can be installed, and allows the top and bottom surfaces of the package body 12 or the first sub-substrate and the second substrate to transmit electrical signals to the light emitting device 11. Various shapes of electrodes (not shown) may be formed at various locations, such as between sub-substrates.

The light emitting element 11 is electrically connected to the electrode by a connecting means such as a wire. In addition to the wire, the light emitting device 11 may be connected to an electrode installed on the package body 12 by flip chip bonding, and the like, and the electrical connection method is not limited to this method and may be applied in various forms.

On the other hand, the package body 12 is formed of a single body and can be used to form a cavity 121 after the hole processing in the vertical direction using a drill or the like, in the present embodiment to secure a variety of conductive patterns and the cavity 121 The second substrate (not shown) having a hollow portion is laminated on the first substrate (not shown) having a flat top surface to be easier to form a), and then fixed using an adhesive or the like to form a package body having a cavity. It may be.

The shape of the cavity 121 of the package body 12 is determined according to the shape of the hollow part formed on the second substrate, and most of the package body 12 is formed in a circular shape which is easy to process, but the present invention is not limited thereto. It may be manufactured in various forms in consideration of the type and shape of the light emitting device.

On the other hand, the inner wall of the cavity 121 may be formed vertically, the light reflected forward in consideration of the fact that the illumination area of the light emitted from the light emitting element 11 is different according to the inclination of the inner wall of the cavity 121. The inner wall may be formed to be inclined to efficiently adjust the amount of light scattered to and from the side.

In this case, the inclination inclination of the inner wall of the cavity 121 may be changed within various ranges in consideration of the characteristics and the orientation angle of the light emitting device 11, and may be selected and used to exhibit desired optical properties according to the product used. . In consideration of this, the inclination inclination of the inner wall of the cavity 121 may be configured to be preferably 30-60 °, more preferably about 45 °.

In addition, the cavity 121 may be configured to have a width and a height of a bottom surface in consideration of the size of the light emitting device 11 and the thicknesses of the first and second wavelength conversion parts 13 and 14.

That is, in general, since the light emitting diode chip used as the light emitting element 11 in the present embodiment is a regular hexagonal light source, light may be generated from each side. Among them, since the amount of light generated on the side of the light emitting diode chip is large, in order to reduce light loss, the reflecting means is positioned on the side of the light emitting element 11 to change the direction of the light generated on the side of the light emitting element 11. It is desirable to. To this end, the height of the inner wall of the cavity 121 is adjusted according to the light emitting device 11 to be installed, and may serve as a light reflection surface on which light emitted from the side surface of the light emitting device 11 is reflected to the upper part of the cavity. That is, since the light emitted from the light emitting element 11 is reflected to the inner wall of the cavity 14 so that the light path is changed to the front, the light loss can be minimized.

The first wavelength converter 13 is installed to cover the cavity 121 of the package body 12, and converts the light emitted from the light emitting element 11 into another wavelength.

In addition, the light emitting device 11 may be formed at a predetermined interval. That is, an empty space surrounded by the side wall of the cavity 121 and the first wavelength converter 13 may be formed. The space may be filled with air, and a material of high transparency, for example, silicon, may be filled to reduce the difference in refractive index between the material constituting the light emitting device 11 and the outside and improve light extraction efficiency. .

In addition, the first wavelength conversion part 13 may be formed with a recess inwardly concave on the surface opposite to the cavity 121. The concave portion may be formed in various forms without limitation, for example, may be formed in a circular shape that is easy to process, and may be provided in a form of accommodating the second wavelength conversion portion inside as described below.

In this case, the first wavelength converter 13 may be formed by mixing a light-transmissive resin and a fluorescent material, and serves to protect the light emitting device 11. In addition, the gap between the second wavelength converter 14 and the light emitting element 11, which is weak to heat, serves to prevent the second wavelength converter 14 from being damaged by the heat during operation of the light emitting element 11. do.

The first wavelength conversion unit 13 is emitted from the resin and the light emitting element 11, such as silicon, polymer, epoxy or silica of high transparency so as to pass while minimizing the loss of light generated from the light emitting element 11 Inorganic fluorescent materials for converting the wavelength of light to convert monochromatic light into white light may be combined.

In particular, the first wavelength conversion unit 13 may be formed by mixing the phosphor and the polymer to be injected and formed of a transparent resin containing an inorganic phosphor, or may be sintered to form a ceramic structure. However, the present embodiment is not limited to such an example, and may have various shapes as long as it has a concave portion and durability enough to accommodate the second wavelength converting portion inside the concave portion.

In addition, the first wavelength converter 13 may further include an ultraviolet absorber to absorb ultraviolet rays emitted from the light emitting element 11.

The second wavelength converter 14 is formed inside the concave portion, and is positioned on the optical path of the light emitted from the light emitting element 11 and is generated from the light emitting element 11 to generate 1. The secondary transformed light can be converted back to secondary. That is, the light emitted from the light emitting element 11 may be provided to be emitted to the upper portion of the light emitting device package through the first wavelength conversion portion 13 and the second wavelength conversion portion 14 in sequence.

The second wavelength converter 14 may include a quantum dot phosphor, for example, may be made of a transparent resin containing a quantum dot phosphor, and silicon may be used as the transparent resin.

In general, the quantum dot phosphor has a small half width of the emission wavelength, which is very advantageous for color reproducibility. However, on the contrary, since it has a weak disadvantage in heat, there is a side that is denatured by heat emitted during operation of the light emitting device 11 and thus it is difficult to exhibit performance.

In the present embodiment, since the second wavelength conversion portion 14 is not directly in contact with the light emitting element 11 but is spaced apart by a predetermined distance through the first wavelength conversion portion 13, it is relatively heat resistant and has a long lifetime. It can have

In addition, the second wavelength conversion unit 14 is generally configured to provide a flat upper surface, but if necessary, the upper surface is concave to the lower side in consideration of the light directivity angle or the like, or the upper surface is convex upward. It may also be configured as a protruding shape.

In this case, the radius of curvature of the second wavelength converter 14 may be set in consideration of the amount of light emitted from the light emitting element 11 and the size of the cavity 121.

As described above, in the present embodiment, light is converted into two stages through two stages of wavelength converting portions of the first and second wavelength converting portions 13 and 14. The light emitted finally in this process may be white light, but is not limited thereto.

In this case, when the light emitting device 11 is a blue light emitting device that emits blue light, the first wavelength conversion unit 13 converts the green phosphor into a second wavelength conversion unit so that the light emitting device package finally emits white light. (14) can contain a red phosphor. Alternatively, on the contrary, the first wavelength converter 13 may include a red phosphor, and the second wavelength converter 14 may include a green phosphor.

First, when the first wavelength converter 13 has a green phosphor, and the second wavelength converter 14 contains a red phosphor, the first wavelength converter 13 has a high luminance, which is an advantage of the inorganic phosphor contained in the first wavelength converter 13. In addition, there is an effect that can utilize the characteristics of high color reproducibility which is an advantage of the quantum dot phosphor contained in the second wavelength conversion part 14.

In contrast, when the first wavelength converter 13 includes a red phosphor and the second wavelength converter 14 includes a green phosphor, the first wavelength converter 13 may prevent reabsorption of light from short wavelengths to long wavelengths. Taking advantage of the quantum dot phosphor contained in the two-wavelength conversion unit 14, there is an effect that can obtain a high color reproducibility in the green wavelength range.

2 is a cross-sectional view schematically showing a light emitting device package according to another embodiment of the present invention. Referring to FIG. 2, in the present exemplary embodiment, the reflective part 25 is disposed on the inner wall of the cavity 221, and the light-transmissive protective layer 26 is disposed on the first and second wavelength conversion parts 23 and 24. Except that, the basic configuration is the same as the embodiment shown in FIG.

The reflector 25 is made of a highly reflective material, and the inner wall of the cavity 221 may be formed of a coating film of a metal material, such as aluminum, so as to further increase the reflectance of the light transmitted from the light emitting device 21. have.

The protective layer 26 may be formed to completely cover the second wavelength converter 24 and seal the recess to cover at least a portion of the first wavelength converter 23. This is to protect the second wavelength converter 24 including the quantum dot phosphor relatively vulnerable to moisture and heat. Therefore, it is preferable that the protective layer 26 and the second wavelength conversion part 24 be completely in contact with each other without a space.

In this case, since the protective layer 26 serves to protect the second wavelength converter 24 and is also the final light exit surface of the light emitting device package, it is preferable to have sufficient light transmittance. Therefore, the protective layer 26 may be a glass plate, and may be made of a light transmissive polymer resin.

3 is a cross-sectional view schematically showing a light emitting device package according to another embodiment of the present invention. Referring to FIG. 3, in the present embodiment, the basic configuration of the first wavelength conversion unit 33 includes a protrusion 331 formed by protruding a part of the first wavelength conversion part and inserted into a portion of the inner wall of the cavity 321. It is the same as the embodiment shown in FIG.

That is, the first wavelength conversion unit 33 is not a horizontal configuration as shown in Figure 3, the projection 331 is formed at a predetermined depth in the center of the lower surface, so as to be fitted to a portion of the inner wall of the cavity 321 Can be configured.

Meanwhile, another region in which the protrusion of the first wavelength converter 33 is not formed may have a flat lower surface as shown in FIGS. 1 and 2. In this way, the coupling with the first wavelength conversion unit 33 can be more firmly and stably secured in both the region where the cavity 321 of the package body 32 is formed and the region where the cavity 321 is not formed.

4 is a cross-sectional view schematically showing a light emitting device package according to another embodiment of the present invention. Referring to FIG. 4, the present embodiment differs from the embodiment illustrated in FIGS. 1 and 2 in that a stepped portion 422 is formed inside the cavity to have a multi-layer structure.

In this case, the cavity may be formed to have a stepped multi-layer structure by using a plurality of sub-substrates having hollow portions that increase in diameter from bottom to top. Details similar to those of the foregoing embodiment will be omitted.

In the present embodiment, an embodiment in which the third wavelength conversion part 48 having a different material from the first and second wavelength conversion parts is formed in the stepped part 422 formed in the cavity is illustrated. As such, the stepped portion 422 may be utilized as a space in which the wavelength conversion portion may be separately disposed. In addition, the stepped portion 422 may be formed in plural, and each of the plurality of formed stepped portions may be formed one by one by selectively applying wavelength converting materials such that different constituent materials, different colors, or the same colors overlap each other. Implementation would be possible. At this time, if necessary, one wavelength conversion unit may be configured by mixing a plurality of color fluorescent materials, and in the case of forming a wavelength conversion unit having a different color for each of the plurality of stepped portions, there is an advantage of improving luminous flux and CRI.

In addition, a pair of first and second wavelength converting portions are disposed in the stepped portion 422, and the first and second wavelength converting portions are repositioned thereon, so that the first and second wavelength converting portions are alternately stacked. It may be provided in a form.

5 is a graph showing light emitting performance according to time and temperature changes in a light emitting device package according to the prior art.

Referring to FIG. 5, when the luminescence performance at the start of the test was 100%, about 20% at room temperature, about 20% at room temperature, and 40% and 90% of the stiffness at a temperature of 85 ° and 60 °, respectively. It can be seen that there is a performance drop.

6 is a graph showing a change in light wavelength with time and temperature change in a light emitting device package according to the prior art.

Referring to FIG. 6, it can be seen that the light emission amount is significantly weakened over time, especially at wavelengths around 530 nm and 600 nm.

7 is a graph showing light emitting performance according to time and temperature changes in a light emitting device package according to an embodiment of the present invention.

Referring to FIG. 7, it can be seen that there is almost no deterioration in performance at room temperature and 60 degrees even after about 1000 hours after the start of the test. In addition, it can be seen that even under poor conditions of 85 ° C, the drop in light emission performance is only about 40%, which shows very excellent stability and lifespan compared to the above-described prior art.

8 is a graph showing a change in light wavelength according to time and temperature changes in a light emitting device package according to an embodiment of the present invention.

It can be seen that even after about 1000 hours, the same light output is shown in all light wavelength regions.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is defined by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims, As will be described below.

11, 21, 31, 41: light emitting elements 12, 22, 32, 42: package body
121, 122, 321: cavity 13, 23, 33, 43: the first wavelength conversion unit
14, 24, 34, 44: second wavelength conversion portion 25: reflective layer
26: protective layer 331: protrusion
422 step

Claims

A light emitting element;
A package body on which the light emitting element is mounted;
A first wavelength conversion unit having a concave portion formed on an upper surface thereof and having a first wavelength conversion material converting the wavelength of light emitted from the light emitting device into light having a first wavelength; And
A second wavelength conversion unit formed in the concave portion and having a second wavelength conversion material converting wavelengths of light emitted from the light emitting device into light having a second wavelength;
Emitting device package.

The method of claim 1,
The first wavelength converting material includes an inorganic phosphor, and the second wavelength converting material includes a quantum dot phosphor.

3. The method of claim 2,
Light emitting device package further comprises a protective layer formed on the first wavelength conversion portion to seal the recess.

The method of claim 3,
The protective layer is a light emitting device package, characterized in that the glass plate or a light transmitting polymer compound.

3. The method of claim 2,
The first wavelength conversion unit is a light emitting device package, characterized in that the ceramic structure consisting of the inorganic phosphor.

3. The method of claim 2,
The first wavelength conversion unit is a light emitting device package, characterized in that made of a transparent resin containing the inorganic phosphor.

3. The method of claim 2,
The second wavelength conversion unit is a light emitting device package, characterized in that made of a transparent resin containing the quantum dot phosphor.

3. The method of claim 2,
The light emitting device emits blue light,
The first wavelength conversion material is a red phosphor, the second wavelength conversion material is a light emitting device package, characterized in that the green phosphor.

3. The method of claim 2,
The light emitting device emits blue light,
The first wavelength converting material is a green phosphor, and the second wavelength converting material is a light emitting device package, characterized in that the red phosphor.

The method of claim 1, wherein
The package body includes a cavity that provides a mounting area of the light emitting device,
The first wavelength conversion unit is a light emitting device package, characterized in that formed to cover the upper surface of the cavity.

The method of claim 1, wherein
The first wavelength conversion unit is a light emitting device package, characterized in that formed in a cup shape.

The light emitting device package of claim 1, wherein at least a part of the first wavelength conversion part is formed to correspond to the shape of the inner wall of the cavity and is inserted into the cavity.

The method of claim 1,
The first wavelength conversion unit is a light emitting device package, characterized in that formed spaced apart from the bottom surface of the cavity.

The method of claim 1,
At least one of the first and the second wavelength conversion unit further comprises a diffusion material for smooth diffusion of light in addition to the fluorescent material.

The method of claim 1,
The cavity has a light emitting device package, characterized in that the inner surface has a plurality of layer structure stepped.

16. The method of claim 15,
And a third wavelength conversion unit formed in at least one of the plurality of layer structures of the cavity and having a different material from the first and second wavelength conversion units.