KR102288404B1 - Light emitting device - Google Patents

Abstract

A light emitting device is disclosed. The light emitting device includes a light emitting diode that emits light having a peak wavelength within a range of 415 to 430 nm, and a wavelength converter positioned on the light emitting diode, wherein the wavelength converter emits light having a peak wavelength of a cyan light band. and a red phosphor emitting light having a peak wavelength in the red light band, wherein the red phosphor includes at least two types of phosphors having different peak wavelengths, and light emitted from the light emitting device has a CRI value of 90 or more.

Description

Light Emitting Device {LIGHT EMITTING DEVICE}

The present invention relates to a light emitting device, and more particularly, to a light emitting device having high reliability and high color rendering.

Recently, light emitting diodes have been used as new solid-state light sources in various fields such as lighting, display, and medicine. Such a light emitting diode may be applied to a light emitting device processed in the form of a light emitting diode package or a light emitting diode module to be suitable for the application field.

Since light emitting diodes generally emit light having a narrow peak wavelength at half maximum width, a plurality of active layers emitting light in various wavelength bands are required in one light emitting diode to implement white light with one light emitting diode. However, manufacturing a light emitting diode having such a plurality of active layers is very inefficient for technical and process reasons.

Accordingly, in order to implement a white light emitting device using a light emitting diode, a light emitting device including a light emitting diode and a phosphor that excites light emitted from the light emitting diode into light of a different wavelength band is generally used. In this case, white light may be realized by mixing the light emitted from the light emitting diode and the light excited by the phosphor.

Specifically, white light may be obtained by applying a phosphor emitting yellow green or yellow by absorbing a portion of blue light as excitation light on a blue light emitting diode chip. Referring to Korean Patent Application Laid-Open No. 10-2004-0032456, a phosphor that emits yellow-green to yellow light as an excitation source is attached to a light-emitting diode chip that emits blue light as an excitation source, so that blue light emission of the light-emitting diode and yellow-green to yellow light emission of the phosphor are applied. Accordingly, a light emitting diode emitting white light is disclosed. However, since the white light emitting diode package using this method utilizes the light emission of the yellow phosphor, color rendering and color reproducibility are low due to the lack of spectrum in the green and red regions of the emitted light. Accordingly, this type of light emitting device has limitations in application to lighting or display fields.

In order to solve this problem, a light emitting diode is manufactured using a blue light emitting diode chip and green and red phosphors using blue light as excitation light. That is, white light having high color rendering can be realized through a mixture of blue light and green light and red light excited by blue light. However, in a light emitting device using a blue light emitting diode chip, since the intensity of blue light is relatively strong, when it is used as lighting, there is a high possibility that various side effects, for example, sleep disturbance, etc. may occur in the human body.

Meanwhile, in order to realize white light, an ultraviolet light emitting diode chip may be used instead of the blue light emitting diode chip. However, since the ultraviolet light emitting diode chip emits light of a wavelength having a relatively high energy, a decomposition phenomenon of the encapsulant may occur, and problems such as discoloration and deterioration of the lead frame may occur. In addition, the encapsulant may be manufactured using a material having relatively high resistance to UV rays (eg, methyl silicone), but these materials have high hardness and thus have poor mechanical reliability. Therefore, the reliability of the light emitting device including the ultraviolet light emitting diode chip is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a light emitting device having improved reliability and color rendering.

A light emitting device according to an aspect of the present invention includes: a light emitting diode emitting light having a peak wavelength within a range of 415 to 430 nm; and a wavelength converter positioned on the light emitting diode, wherein the wavelength converter comprises a blue phosphor emitting light having a peak wavelength of a blue light band, a cyan phosphor emitting light having a peak wavelength of a cyan light band, and a red light band. and a red phosphor emitting light having a peak wavelength, wherein light emitted from the light emitting device has a CRI value of 90 or more.

Accordingly, a light emitting device having excellent color rendering can be provided.

The cyan phosphor may include at least one of LuAG, YAG, nitride, and silicate-based phosphors.

The red phosphor may include at least one of CASN, CASON, and SCASN-based phosphors.

The blue phosphor emits light having a peak wavelength in the range of 450 to 480 nm, the cyan phosphor emits light having a peak wavelength in the range of 500 to 540 nm, and the red phosphor emits light having a peak wavelength in the range of 610 to 630 nm. can be released

The blue phosphor may include a phosphor represented by the formula (Sr,Ba) _x (PO _y ) _z Cl _w : Eu, and the cyan phosphor may include Lu _x Al _y O _z : Ce and/or Lu _x (Al, Ga) _y O _z : may include a phosphor represented by the formula Ce, and the red phosphor may include a phosphor represented by the formula (Sr,Ca) _x Al _y Si _z N _w : Eu.

Furthermore, the phosphors disposed in the wavelength converter are, (Sr,Ba) _x (PO _y ) _z Cl _w :Eu : (Lu _x Al _y O _z :Ce and/or Lu _x (Al,Ga) _y O _z A mass ratio of :Ce) : (Sr,Ca) _x Al _y Si _z N _w :Eu = (1 to 4) : (6 to 9) : (0.2 to 1) may be satisfied.

In addition, the blue phosphor may _{include a phosphor represented by the formula (Sr,Ba) 10} (PO ₄ ) ₆ Cl ₂ :Eu, and the cyan phosphor may include Lu ₃ Al ₅ O ₁₂ : Ce and/or Lu ₃ ( Al,Ga) ₅ O ₁₂ : may include a phosphor represented by the formula Ce, and the red phosphor may include a phosphor represented by the formula (Sr,Ca) ₁ Al ₁ Si ₁ N ₃ : Eu.

In some embodiments, the light emitting device may emit light having a CRI value of 95 or higher.

In addition, the blue phosphor may _{include a phosphor represented by the formula (Sr,Ba) x} (PO _y ) _z Cl _w : Eu, and the cyan phosphor may include Lu _x Al _y O _z : Ce and/or Lu _x ( A phosphor represented by the formula Al,Ga) _y O _z : Ce may be included, and the red phosphor may include a phosphor represented by the formula Ca _x Al _y Si _z (ON) _w : Eu.

The phosphors disposed in the wavelength converter are, (Sr,Ba) _x (PO _y ) _z Cl _w :Eu : (Lu _x Al _y O _z :Ce and/or Lu _x (Al,Ga) _y O _z :Ce ) : Ca _x Al _y Si _z (ON) _w : Eu = (1 to 6) : (2 to 7): A mass ratio of (0.5 to 4) may be satisfied.

Further, the blue phosphor may _{include a phosphor represented by the formula (Sr,Ba) 10} (PO ₄ ) ₆ Cl ₂ :Eu, and the cyan phosphor may include Lu ₃ Al ₅ O ₁₂ : Ce and/or Lu ₃ ( Al,Ga) ₅ O ₁₂ : A phosphor represented by the formula of Ce may be included, and the red phosphor may include a phosphor represented by the formula: Ca ₁ Al ₁ Si ₁ (ON) ₃ : Eu.

The wavelength converter may cover at least a portion of the light emitting diode.

The wavelength converter may be spaced apart from the light emitting diode.

The light emitting device according to the present invention can emit light of high color rendering. In addition, a light emitting device having high thermal and mechanical reliability can be provided, and a light emitting device can be provided in which reliability of the light emitting device does not deteriorate due to ultraviolet light, so that color rendering does not deteriorate according to the use of the light emitting device.

1 is a cross-sectional view for explaining a light emitting device according to an embodiment of the present invention.
2 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.
3 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.
4 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.
5 is a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention.
6 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art to which the present invention pertains. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. In addition, when one component is described as being “on” or “on” another component, each component is different from each component, as well as when each component is “immediately above” or “directly on” the other component. It includes the case where another component is interposed between them. Like reference numerals refer to like elements throughout.

1 is a cross-sectional view for explaining a light emitting device according to an embodiment of the present invention.

Referring to FIG. 1 , the light emitting device includes a light emitting diode 120 and a wavelength converter 130 , and may further include a base 110 .

In this embodiment, the light emitting diode 120 may be disposed on the base 110 . The base 110 may be, for example, a housing as shown.

The housing may include a cavity opened upward, and the light emitting diode 120 may be mounted in the cavity. The side surface of the cavity may be formed to be inclined, so that light emitted from the light emitting diode 120 is reflected to improve the light emitting efficiency of the light emitting device of the present embodiment. Furthermore, a reflective material may be further disposed on the inner side surface of the cavity.

When the base 110 is formed as a housing, the housing is a general plastic including a polymer, acrylonitrile butadiene styrene (ABS), liquid crystalline polymer (LCP), polyamide (PA), polyphenylene sulfide (IPS), or thermoplastic elastomer (TPE). ), etc., or may be formed of metal or ceramic. However, the present invention is not limited thereto.

Also, the base 110 may include at least two lead terminals, and the lead terminals and the light emitting diode 120 may be electrically connected to each other. The lead terminal may allow the light emitting device to be connected to an external power source. The light emitting diode 120 may be positioned on the lead terminal.

Meanwhile, the base 110 is not limited thereto, and is not limited as long as it can support the light emitting diode 120 , and may include various well-known configurations. For example, the base 110 may include a conductive or insulating substrate and a PCB on which the light emitting diode 120 is mounted, and may further include a heat sink for emitting heat generated from the light emitting diode 120 . there is.

The light emitting diode 120 may include an n-type semiconductor layer and a p-type semiconductor layer to have a structure capable of emitting light through a combination of holes and electrons. The light emitting diode 120 may have a structure such as a horizontal type, a vertical type, or a flip chip type, and the configuration and shape of the light emitting diode 120 are not limited.

The light emitting diode 120 may emit light having a peak wavelength in the visible region, and in particular, may emit light having a peak wavelength located in a range of 415 to 430 nm. In addition, a full width half maximum (FWHM) of a peak wavelength of light emitted by the light emitting diode 120 may be less than or equal to 40 nm, but the present invention is not limited thereto. The light emitting device of this embodiment includes the light emitting diode 120 that emits light having a peak wavelength in the above-described range, so that the reliability and luminous efficiency of the light emitting device can be prevented from being deteriorated by ultraviolet rays emitted from the light emitting diode. Also, it is possible to minimize the harm to the human body by minimizing the light in the wavelength band of about 450nm.

The wavelength converter 130 may be positioned on the light emitting diode 120 , and further, may at least partially cover the light emitting diode 120 , and further encapsulate the light emitting diode 120 . That is, the wavelength converter 130 may be located on the light emission path of the light emitting diode 120 .

The wavelength converter 130 may include a support part 131 , a cyan phosphor 133 , a red phosphor 135 , and a blue phosphor 137 irregularly dispersed in the support part 131 .

The supporting part 131 is not limited as long as it is a material capable of supporting the first and red phosphors 133 and 135 , and may have a transparent or translucent characteristic. The supporting part 131 is formed of, for example, a polymer including at least one of a silicone-based, an epoxy-based, a PMMA (polymethyl methacrylate)-based, a PE (polyethylene)-based, and a PS (polystyrene) series. It may also be formed of an inorganic material such as glass.

When the supporting unit 131 is formed of a polymer material, the wavelength converting unit 130 may serve as an encapsulant for encapsulating the light emitting diode 120 in addition to converting the wavelength of light emitted from the light emitting diode 120 . there is. In addition, the wavelength conversion unit 130 may be located on the base 110 , and as in this embodiment, when the base 110 includes a cavity, the wavelength conversion unit 130 may be disposed within the cavity. . Furthermore, the upper surface of the wavelength conversion unit 130 may be formed in various shapes, such as a convex lens shape, a flat plate shape (not shown), and a shape having predetermined irregularities on the surface. According to this embodiment, the wavelength converter 130 has been disclosed as having a convex lens shape, but is not limited thereto.

The cyan phosphor 133 , the red phosphor 135 , and the blue phosphor 137 may be irregularly dispersed and disposed in the support unit 131 .

Specifically, the cyan phosphor 133 may excite incident light to emit cyan light, the red phosphor 135 may excite the incident light to emit red light, and the blue phosphor 137 may emit red light. may excite the incident light to emit blue light. Accordingly, in the light emitting device of the present invention, violet light emitted from the light emitting diode 120, cyan light excited by the cyan phosphor 133, red light excited by the red phosphor 135, and blue phosphor ( 137) may emit white light by mixing blue light excited by it.

Meanwhile, white light emitted by the light emitting device of the present embodiment may have a CRI value of 90 or more, and further, may have a CRI value of 95 or more. The CRI value in the above range can be achieved by adjusting the mixing ratio of the cyan phosphor 133, the red phosphor 135, and the blue phosphor 137, which will be described in detail below.

A peak wavelength of cyan light emitted from the cyan phosphor 133 may be located within a wavelength range of 500 to 540 nm. The cyan phosphor 133 may include at least one of a LuAG series, a YAG series, a beta-SiAlON series, a nitride series, and a silicate series, but is not limited thereto. A peak wavelength of red light emitted by the red phosphor 135 may be located within a wavelength range of 600 to 650 nm, and the red phosphor 135 includes at least two different types of phosphors emitting light having different peak wavelengths. can do. The red phosphor 135 may include a nitride-based phosphor represented by CASN, CASON, and SCASN, but is not limited thereto. A peak wavelength of blue light emitted from the blue phosphor 137 may be located within a wavelength range of 450 to 480 nm. The blue phosphor 137 may include at least one of an SBCA series, a Ba-Al-Mg (BAM) series, a silicate series, and a nitride series, but is not limited thereto.

First, the light emitting device according to the present embodiment may have a CRI value of 90 or more.

In this case, the blue phosphor 137 may include a phosphor that emits light having a peak wavelength within a range of 450 to 480 nm. For example, the blue phosphor 137 may include _{a phosphor represented by the formula (Sr,Ba) x} (PO _y ) _z Cl _w : Eu, and more specifically, the blue phosphor 137 may include (Sr,Ba ) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu may include a phosphor represented by the chemical formula.

The cyan phosphor 133 may include a LuAG-based phosphor, and the LuAG-based phosphor includes a phosphor expressed by the formula _{Lu x} Al _y O _z : Ce and/or Lu _x (Al,Ga) _y O _{z: Ce.} can do. More specifically, the LuAG-based phosphor may include Lu ₃ Al ₅ O ₁₂ :Ce and/or Lu ₃ (Al,Ga) ₅ O ₁₂ :Ce.

The red phosphor 135 may include a phosphor emitting light having a peak wavelength within the range of 610 to 650 nm, and further, may include a phosphor emitting light having a peak wavelength within the range of 610 to 630 nm. For example, the red phosphor 135 may include a phosphor expressed by the formula _{(Sr,Ca) x} Al _y Si _z N _w : Eu that emits light having a peak wavelength within a range of 610 to 630 nm. More specifically, the red phosphor 135 may include a phosphor represented by the formula _{(Sr,Ca) 1} Al ₁ Si ₁ N _{3 :Eu.}

The mixing ratio of the cyan phosphor 133 , the red phosphor 135 , and the blue phosphor 137 may be adjusted so that the light emitting device of this embodiment has a CRI value of 90 or more. For example, the mixing ratio between the cyan phosphor 133, the red phosphor 135, and the blue phosphor 137 is a mass ratio, and the blue phosphor 137: the cyan phosphor 133: the red phosphor 135 = (1 to 4). ) : (6 to 9): (0.2 to 1).

Furthermore, the light emitting device according to the present embodiment may have a CRI value of 95 or more.

In this case, the blue phosphor 137 may include a phosphor that emits light having a peak wavelength within a range of 450 to 480 nm. For example, the blue phosphor 137 may include _{a phosphor represented by the formula (Sr,Ba) x} (PO _y ) _z Cl _w : Eu, and more specifically, the blue phosphor 137 may include (Sr,Ba ) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu may include a phosphor represented by the chemical formula.

The cyan phosphor 133 may include a LuAG-based phosphor, and the LuAG-based phosphor includes a phosphor expressed by the formula _{Lu x} Al _y O _z : Ce and/or Lu _x (Al,Ga) _y O _{z: Ce.} can do. More specifically, the LuAG-based phosphor may include Lu ₃ Al ₅ O ₁₂ :Ce and/or Lu ₃ (Al,Ga) ₅ O ₁₂ :Ce.

The red phosphor 135 may include a phosphor emitting light having a peak wavelength within a range of 610 to 650 nm, and further, may include a phosphor emitting light having a peak wavelength within a range of 630 to 640 nm. For example, the red phosphor 135 may include a phosphor expressed by the formula _{Ca x} Al _y Si _z (ON) _w : Eu, which emits light having a peak wavelength within a range of 630 to 640 nm. More specifically, the red phosphor 135 may include a phosphor represented by the formula _{Ca 1} Al ₁ Si ₁ (ON) _{3 :Eu.}

The mixing ratio of the cyan phosphor 133 , the red phosphor 135 , and the blue phosphor 137 may be adjusted so that the light emitting device of this embodiment has a CRI value of 90 or more. For example, the mixing ratio between the cyan phosphor 133, the red phosphor 135, and the blue phosphor 137 is a mass ratio, and the blue phosphor 137: the cyan phosphor 133: the red phosphor 135 = (1 to 6). ) : (2 to 7): (0.5 to 4).

According to embodiments of the present invention, it is possible to provide a light emitting device emitting white light having a CRI value of 90 or more, and furthermore, 95 or more by adjusting a compounding ratio of the phosphors included in the wavelength converter 130 of the light emitting device. In addition, since the wavelength-converted light emitted from the light emitting diode 120 emitting light having a peak wavelength of 415 to 430 nm into phosphors to emit white light, damage to the light emitting device by ultraviolet light can be prevented. Accordingly, as the driving time of the light emitting device increases, it is possible to prevent the light emitting intensity and color rendering properties of the light emitting device from being deteriorated.

2 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.

The light emitting device of FIG. 2 is different from the light emitting device of FIG. 1 in that it further includes a buffer unit 140 . Hereinafter, the light emitting device of the present embodiment will be described focusing on the differences, and detailed description of the same configuration will be omitted.

Referring to FIG. 2 , the light emitting device includes a base 110 , a light emitting diode 120 , a wavelength conversion unit 130 , and a buffer unit 140 .

The buffer unit 140 may be disposed between the light emitting diode 120 and the wavelength conversion unit 130 . Accordingly, the light emitting diode 120 and the wavelength converter 130 may be spaced apart.

The buffer unit 140 may be formed of a transparent or translucent insulating material, and may include a polymer material including silicone, epoxy, PMMA, PE, PS, or the like. The buffer unit 140 may serve to protect the light emitting diode 120 from the external environment, and furthermore, it may prevent the wavelength conversion unit 130 from being damaged due to heat generated when the light emitting diode 120 is driven. .

In addition, the hardness of the wavelength conversion unit 130 may be higher than the hardness of the buffer unit 140 . Accordingly, the light emitting diode 120 can be effectively protected by the wavelength conversion unit 130 positioned outside the light emitting device and having a relatively high hardness. In addition, since the hardness of the buffer unit 140 in contact with the light emitting diode 120 is formed to be relatively low, the probability of cracks occurring in the buffer unit 140 is reduced. Accordingly, it is possible to more effectively prevent the light emitting diode 120 from being contaminated or damaged by external factors due to cracks occurring in the buffer unit 140 .

3 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.

In the light emitting device of FIG. 3 , as compared with the light emitting device of FIG. 1 , the wavelength conversion unit 130 includes a first wavelength conversion unit 130a , a second wavelength conversion unit 130b , and a third wavelength conversion unit 130c . There is a difference in inclusion. Hereinafter, the light emitting device of the present embodiment will be described focusing on the differences, and detailed description of the same configuration will be omitted.

Referring to FIG. 3 , the light emitting device according to the present embodiment includes a base 110 , a light emitting diode 120 , and a wavelength converter 130 . The wavelength converter 130 may include a first wavelength converter 130a, a second wavelength converter 130b, and a third wavelength converter 130c.

The first wavelength conversion unit 130a may include a supporting unit 131 and a red phosphor 135 , and the second wavelength conversion unit 130b may include a supporting unit 131 and a cyan phosphor 133 . In addition, the third wavelength conversion unit 130c may include a support unit 131 and a blue phosphor 137 . In addition, the second wavelength converter 130b may be positioned on the first wavelength converter 130a , and the third wavelength converter 130c may be positioned on the second wavelength converter 130b . Furthermore, the light incident to the second wavelength conversion unit 130b may be incident after passing through the first wavelength conversion unit 130a, and the light incident to the third wavelength conversion unit 130c may be applied to the first and second wavelength conversion units 130c. It may be loaded after passing through the wavelength conversion units 130a and 130b.

Accordingly, when the light emitting device is driven, light excited by the red phosphor 135 is first emitted by the first wavelength converter 130a, and the light passing through the first wavelength converter 130a is converted to the cyan phosphor 133 ) is excited and emitted, and is excited and emitted by the blue phosphor 137 of the third wavelength converter 130c by light passing through the first and second wavelength converters 130a and 130b. That is, the wavelength of the light converted by the red phosphor 135 of the first wavelength conversion unit 130a is a longer wavelength than the wavelength of the light converted by the cyan phosphor 133 of the second wavelength conversion unit 130b, The wavelength of the light converted by the cyan phosphor 133 of the second wavelength converter 130b is longer than the wavelength of the light converted by the blue phosphor 137 of the fourth wavelength converter 130c. Accordingly, it is possible to prevent the wavelength-converted light by one phosphor from being absorbed again by another phosphor or from being lost.

The first wavelength conversion unit 130a may cover the light emitting diode 120 , the second wavelength conversion unit 130b may cover the first wavelength conversion unit 130a , and the third wavelength conversion unit 130c may include The second wavelength conversion unit 130b may be covered. The first to third wavelength converters 130a, 130b, and 130c may be formed of materials having substantially the same hardness as each other, or alternatively, may be formed of materials having different hardnesses. The hardness of the first wavelength conversion unit 130a may be lower than that of the third wavelength conversion unit 130c, and in this case, similar to the buffer unit 140 of the above-described embodiment of FIG. 2 , the light emitting diode 120 . It is possible to prevent damage to the light emitting device due to thermal and mechanical factors generated in the .

4 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention. The light emitting device of FIG. 4 is different from the light emitting device of FIG. 1 in that the wavelength converter 130 ′ is spaced apart from the light emitting diode 120 . Hereinafter, the light emitting device of the present embodiment will be described focusing on the differences, and detailed description of the same configuration will be omitted.

Referring to FIG. 4 , the light emitting device includes a base 110 , a light emitting diode 120 , and a wavelength converter 130 ′. Furthermore, the light emitting device may further include a buffer unit 140 .

The wavelength converter 130 ′ may be positioned to be spaced apart from the light emitting diode 120 . In addition, the wavelength conversion unit 130 ′ may be formed in a plate shape, and the plate-shaped wavelength conversion unit 130 ′ includes a cyan phosphor 133 , a red phosphor 135 and a blue phosphor in the carrier 137 . (137) may be formed in an irregularly dispersed arrangement. The plate-shaped wavelength converter 130 ′ may be separately manufactured and disposed on the light emitting diode 120 , or alternatively, it may be manufactured during the manufacturing process of the light emitting device. In addition, the plate-shaped wavelength converter 130 ′ may be provided on the light emitting diode 120 by being mounted on the base 110 and attached thereto.

On the other hand, the spaced region between the light emitting diode 120 and the wavelength converter 130 ′ may be formed in a cavity, or alternatively, may be filled by the buffer unit 140 .

5 and 6 are cross-sectional views for explaining a light emitting device according to another embodiment of the present invention. Hereinafter, the light emitting device of the present embodiments will be described, and detailed description of the same configuration as described above will be omitted.

First, referring to FIG. 5 , the light emitting device includes a light emitting diode 120 , a wavelength conversion unit 130 , and a resin unit 210 .

The light emitting diode 120 includes an upper surface and a lower surface, and in particular, electrode pads (not shown) positioned on the lower surface. Since the light emitting diode 120 includes electrode pads positioned on the lower surface, there is no need to separately provide an electrode in the light emitting device, and the electrode pads can serve as electrodes of the light emitting device.

The light emitting diode 120 has electrode pads on its lower surface and is not limited as long as it is an element capable of emitting light, and may be, for example, a flip-chip type light emitting diode.

The wavelength converter 130 may cover the upper surface and the side surface of the light emitting diode 120 . The thickness of the wavelength converter 130 may be formed uniformly, but is not limited thereto, and the thickness of the side surface and the thickness of the top surface may be different from each other. For example, as shown, the wavelength converter 130 may be conformally coated to have substantially the same thickness.

Meanwhile, unlike shown in FIG. 5 , as shown in FIG. 6 , the wavelength converter 130 may be formed to cover only the upper surface of the light emitting diode 120 . In this case, the resin part 210 may be in contact with the side surface of the light emitting diode 120 .

Referring back to FIG. 5 , the resin part 210 is positioned on the side surface of the light emitting diode 120 and may be formed to cover the wavelength conversion part 130 positioned on the side surface of the light emitting diode 120 . Accordingly, the wavelength conversion unit 130 covering the side surface of the light emitting diode 120 may be interposed between the light emitting diode 120 and the resin unit 210 . On the other hand, when the wavelength conversion unit 130 is located only on the side surface of the light emitting diode 120 , the resin unit 210 may be in contact with the side surface of the light emitting diode 120 and the side surface of the wavelength conversion unit 130 .

The resin part 210 may be formed to surround the light emitting diode 120 , and may serve to support the light emitting diode 120 and the wavelength conversion unit 130 and to protect it from the outside. In addition, the upper surface of the resin unit 210 may be formed substantially parallel to the upper surface of the wavelength conversion unit 130 .

The resin part 210 may be formed of a light-transmitting, semi-transmissive, or reflective material. The directional angle of the light emitting device may be adjusted according to the degree to which the resin unit 210 transmits light. The resin part 210 may include a silicone resin, or a polymer resin such as an epoxy resin, a polyimide resin, or a urethane resin, and further include filler particles such as _{TiO 2 capable of reflecting or scattering light.} may be

According to the embodiments described with reference to FIGS. 5 and 6 , the light emitting diode 120 includes electrode pads positioned on a lower surface thereof, and the light emitting diode 120 is supported by the resin part 210 . Accordingly, in the light emitting device, a separate base can be omitted, and the light emitting device can be miniaturized.

(Experimental Example 1)

The following experimental results were obtained by measuring the CRI values of the light emitting devices according to the embodiments of the present invention. Samples 1 to 4 of a light emitting device including a wavelength converter having a mixing ratio of a cyan phosphor, a red phosphor, and a blue phosphor according to the above-described embodiments were prepared. The light emitting devices of Samples 1 to 4 are samples having different compounding ratios of phosphors, and the compounding ratio in this Experimental Example is a mass ratio.

Specifically, Sample 1 is a light emitting diode having a peak wavelength of about 425 nm, encapsulating the light emitting diode, Lu ₃ (Al,Ga) ₅ O ₁₂ : Ce as a cyan phosphor, (Sr,Ca) ₁ Al _{1 as a red phosphor} Si ₁ N ₃ : Eu, and a blue phosphor (Sr,Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : A light emitting device including a wavelength converter including Eu. At this time, the mixing ratio of the blue phosphor, the cyan phosphor and the red phosphor is (Sr,Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu : Lu ₃ (Al,Ga) ₅ O ₁₂ :Ce : (Sr,Ca) ₁ Al ₁ Si ₁ N ₃ :Eu = 1.0:8.55:0.45.

Samples 2 to 4 each have a light emitting diode having a peak wavelength of about 425 nm, encapsulating the light emitting diode, Lu ₃ (Al,Ga) ₅ O _{12 :Ce as a cyan phosphor, Ca 1} Al ₁ Si ₁ (ON) as a red phosphor ) ₃ : Eu, and (Sr,Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu as a blue phosphor. In this case, the mixing ratio of the blue phosphor, the cyan phosphor, and the red phosphor was applied differently for each sample. The mixing ratio of Sample 2 is (Sr,Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu : Lu ₃ (Al,Ga) ₅ O ₁₂ :Ce : (Sr,Ca) ₁ Al ₁ Si ₁ N ₃ :Eu = 4.0: 3.9: 2.1, and the mixing ratio of Sample 3 is (Sr,Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu: Lu ₃ (Al,Ga) ₅ O ₁₂ :Ce: (Sr,Ca) ₁ Al ₁ Si ₁ N ₃ :Eu = 3.0: 4.5: 2.5, and the mixing ratio of Sample 4 is (Sr,Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu: Lu ₃ (Al,Ga) ₅ O ₁₂ :Ce: ( Sr,Ca) ₁ Al ₁ Si ₁ N ₃ :Eu = 2.0 : 5.3 : 2.7.

Samples 1 to 4 are light emitting device samples that are all substantially the same except for the compounding ratio of the above-described phosphors, and the results of driving the light emitting devices of Samples 1 to 4 with a current of 100 mA under the same conditions are shown in Table 1 below. indicated.

As such, according to embodiments of the present invention, a light emitting device having a CRI value of 90 or more, furthermore, 95 or more may be provided.

Above, the present invention is not limited to the various embodiments and features described above, and various modifications and changes are possible within the scope without departing from the spirit of the claims of the present invention.

Claims (13)

A white light emitting device comprising:
a light emitting diode emitting light having a peak wavelength in the range of 415 to 430 nm; and
It includes a wavelength conversion unit located on the light emitting diode,
The wavelength conversion unit includes a blue phosphor emitting light having a peak wavelength in the blue light band, a cyan phosphor emitting light having a peak wavelength in the cyan light band, and a red phosphor emitting light having a peak wavelength in the red light band,
The blue phosphor emits light having a peak wavelength within the range of 450 to 480 nm and includes a phosphor represented by the formula _{(Sr,Ba) x} (PO _y ) _z Cl _{w : Eu,}
The cyan phosphor emits light having a peak wavelength within the range of 500 to 540 nm and includes a phosphor represented by the formula _{Lu x} (Al,Ga) _y O _{z: Ce,}
The red phosphor emits light having a peak wavelength within the range of 610 to 630 nm and includes a phosphor represented by the formula _{(Sr,Ca) x} Al _y Si _z N _{w: Eu,}
(Sr,Ba) _x (PO _y ) _z Cl _w :Eu : (Lu _x (Al,Ga) _y O _z :Ce) : (Sr,Ca) _x Al _y Si _z N _w :Eu = (1 to 4) ): (3.9 to 8.55): satisfies the mass ratio of (0.45 to 2.7),
The light emitted from the light emitting device has a CRI value of 90 or more. delete delete delete delete delete The method according to claim 1,
The blue phosphor includes a phosphor represented by the formula (Sr,Ba) ₁₀ (PO ₄ ) ₆ Cl _{2 :Eu,}
The cyan phosphor includes a phosphor represented by the formula _{Lu 3} (Al,Ga) ₅ O _{12: Ce,}
The red phosphor is a light emitting device including a phosphor represented by the formula (Sr,Ca) ₁ Al ₁ Si ₁ N _{3 :Eu.} The method according to claim 1,
The light emitting device emits light having a CRI value of 95 or more. delete delete delete The method according to claim 1,
The wavelength converter covers at least a portion of the light emitting diode. The method according to claim 1,
The wavelength conversion unit is a light emitting device spaced apart from the light emitting diode.

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