KR20130057135A - Material changing wavelength - Google Patents

Abstract

PURPOSE: A wavelength conversion material has a uniform size of phosphor powder and to improve photoluminescence brightness and photoluminescence excitation performance. CONSTITUTION: A wavelength conversion material comprises A_(3-x)Si_6O_3N_8Cl_y:B^(2+)_z where 0<x<3, 0<y<10, 0.001<z<0.3, A is alkali earth metal element, and B is rare earth element. A base material is represented by A_(3-x)Si_6O_3N_8Cl_y and an activating material is represented by B6^(2+)_z. The wavelength conversion material consists of phosphor powder of which size is 10-20 micron. A is at least one of Be, Mg, Ca, Sr, Ba, and Ra, and B is at least one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. [Reference numerals] (AA) Light emitting wavelength; (BB) About 40% enhancement

Description

Material changing wavelength

An embodiment provides a wavelength converting material.

BACKGROUND ART Light emitting devices such as a light emitting diode (LD) or a laser diode using semiconductor materials of Group 3-5 or 2-6 group semiconductors are widely used for various colors such as red, green, blue, and ultraviolet And it is possible to realize white light rays with high efficiency by using fluorescent materials or colors, and it is possible to realize low energy consumption, semi-permanent life time, quick response speed, safety and environment friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps .

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting, automotive headlights, and traffic lights.

The light emitting device emits light having energy determined by an energy band inherent in a material in which electrons injected through the first conductive semiconductor layer and holes injected through the second conductive semiconductor layer meet each other to form an active layer (light emitting layer). do. In the light emitting device package, the phosphor is excited by the light emitted from the light emitting device to emit light having a longer wavelength region than the light emitted from the active layer.

YAG phosphors or Silicate phosphors having excellent color reproducibility are widely used as phosphors, and the phosphor powder may have an uneven size and the luminance of the excitation light source may not be sufficient, thereby degrading PL and PLE characteristics.

The embodiment is to provide a wavelength conversion material having a uniform phosphor powder and improved PL luminance and PLE characteristics even at high temperatures.

Examples are A _{3- x} Si ₆ O ₃ N ₈ Cl _y : B ²⁺ _z (0 <x <3, 0 <y <10, 0.001 <z <0.3, A is an alkaline earth metal element, B is a rare earth Element) is provided.

Another example is A _{3-x- z} Si ₆ O ₃ N ₈ Cl _y : B ²⁺ _x (0 <x <3, 0 <y <10, 0.001 <x + z <3, where A is an alkaline earth metal element) And B is a rare earth element).

The activator may be B ²⁺ _z or B ²⁺ _x and the parent may be A _{3- x} Si ₆ O ₃ N ₈ Cl _y or A _{3-x- z} Si ₆ O ₃ N ₈ Cl _y .

The wavelength converting material may comprise phosphor powder having a size of 10 to 20 micrometers.

A is at least one of Be, Mg, Ca, Sr, Ba, and Ra, and B is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu It may be at least one of.

A may be (Sr, Ba), and B may be Eu.

The phosphor according to an embodiment is in particular a matrix _{(Sr, Ba) 3 Si 6} O 3 N 8 uses using Cl _2, and the case of using Eu ^{2 +} body activity, the 450-nm wavelength of the light as compared to other phosphor with an excitation light source In this case, the luminance may be improved by about 40%, and the PLE characteristic may be improved in a wide range of wavelengths.

1 is a view showing an embodiment of a light emitting device package,
2 is a flowchart of an embodiment of a method of manufacturing a phosphor of the light emitting device package of FIG.
3 compares the PL characteristics of the phosphors according to the embodiment with other phosphors,
Figure 4 compares the PLE characteristics of the phosphor according to the embodiment with other phosphors,
5 shows an embodiment of a phosphor;
6 shows another phosphor,
7 is a view showing an embodiment of a head lamp including a light emitting device package,
8 is a diagram illustrating an embodiment of a display device including a light emitting device package.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, when described as being formed on the "on or under" of each element, the (up) or down (on) or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. In addition, the size of each component does not necessarily reflect the actual size.

1 is a view showing an embodiment of a light emitting device package.

The light emitting device package 100 according to the embodiment includes a package body 110, a first lead frame 121 and a second lead frame 122 installed on the package body 110, and the package body 110. A light emitting device 130 installed and electrically connected to the first lead frame 121 and the second lead frame 122, and a molding part 150 covering the surface or the side surface of the light emitting device 130. do.

The package body 110 may include a silicon material, a synthetic resin material, or a metal material. An inclined surface may be formed around the light emitting device 130 to increase light extraction efficiency.

The first lead frame 121 and the second lead frame 122 are electrically separated from each other, and provide power to the light emitting device 130. In addition, the first lead frame 121 and the second lead frame 122 may increase light efficiency by reflecting light generated from the light emitting device 130, and heat generated from the light emitting device 130. It may also play a role in discharging it to the outside.

The light emitting device 130 may be a horizontal light emitting device, a vertical light emitting device, or the like, and one or two or more light emitting devices may be mounted on the package body 110 or the first lead frame 121 or the like. The second lead frame 122 is disposed on the first lead frame 121 through the conductive adhesive layer 135 in FIG. 1.

The light emitting device 130 may be electrically connected to the first lead frame 121 and the second lead frame 122 by any one of a wire method, a flip chip method, or a die bonding method. In FIG. 1, the light emitting device 130 is connected to the first lead frame 121 and the conductive adhesive layer 135 and is bonded to the second lead frame 122 and the wire 140.

The molding part 150 may surround and protect the light emitting device 130. In addition, the molding unit 150 includes a wavelength conversion material such as a phosphor 155 and is excited by the light of the first wavelength region emitted from the light emitting device 130 to emit light of the second wavelength region having a longer wavelength. can do.

As an example of the phosphor 155, a wavelength converting material having a chemical formula of A _{3 -x} Si ₆ O ₃ N ₈ Cl _y : B ²⁺ _z may be used, where 0 <x <3, 0 <y <10. , 0.001 <z <0.3. The above-mentioned wavelength conversion material may be _{denoted as an} active material of B ²⁺ _z , a parent of A _{3- x} Si ₆ O ₃ N ₈ Cl _y, and A _{3- x} Si ₆ O ₃ N ₈ Cl _y : B ²⁺ _z . , A is an alkaline earth metal element, B may be a rare earth element, which will be described later. The phosphor 155 according to another embodiment may use a wavelength converting material having a chemical formula of A _{3-x- z} Si ₆ O ₃ N ₈ Cl _y : B ²⁺ _x , where 0 <x <3, 0 <y <10, 0.001 <x + z <3. The phosphor 155 according to another embodiment may use a wavelength conversion material having a chemical formula of A _{3-x- z} Si ₆ O ₃ N ₈ Cl _y C _z : B ²⁺ _x , where 0 <x <3, 0 <y <10, 0.001 <x + z <3.

The above-mentioned phosphors have a wide wavelength range of about 300 nanometers to 450 nanometers of the excitation light source, and thus may be used in various ways such as Blue LED and UV LED. In the light emitting device package according to the present embodiment, when blue light is emitted from the light emitting device, the above-mentioned phosphor is excited by the blue light to emit yellow light, and thus white light may be realized in the entire package.

FIG. 2 is a flowchart of an embodiment of a method of manufacturing a phosphor of the light emitting device package of FIG. 1. Hereinafter, a method of manufacturing the above-described phosphor will be described with reference to FIG. 2.

Phosphor according to the present embodiment can be prepared by the solid phase reaction method, first prepare a raw material (S110).

As raw materials, alkaline earth metals, silicon (Si), oxygen (O), nitrogen (N), chlorine (Cl) and rare earth elements are prepared. The alkaline earth metals are beryllium (Be), magnesium (Mg) and calcium (Ca). ), Strontium (Sr), barium (Ba) and radium (Ra) may be at least one, and the rare earth element is lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), pro Methium (Pm), Samarium (Sm), Europium (Eu), Gadullium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Tolium (Tm), Ytterbium (Tm) Yb) and ruthenium (Lu).

_{(Sr, Ba) 3 Si 6} O 3 N 8 Cl 2: When using the Ba and Sr In the manufacture of Eu ^{2 +,} the above-described raw materials, such as for example the alkaline earth metal BaCO _3, SrCO _3, Si ₃ Prepare N ₄ , NH ₄ Cl, Eu ₂ O ₃ . That is, BaCO ₃ is used as a raw material for barium, SrCO ₃ is used as a raw material for strontium, Si ₃ N ₄ is used as a raw material for silicon, NH ₄ Cl is used as a raw material for chlorine, and Eu is used as a raw material for europium. ₂ O ₃ can be used. Such raw materials may be referred to as precursors.

In the present embodiment, as a raw material of chlorine, BaCl ₂ , SrCl ₂ , MgCl _2, etc. may be used in addition to NH ₄ Cl. The precursors described above may be other materials containing ions of elements to be used, such as barium, strontium, silicon, chlorine, and europium.

Then, the above-described raw material is mixed (S120).

Phosphor to prepare the above-described raw materials, in the case of this embodiment is improved according to the composition ratio of (Sr, Ba) ₃ Si ₆ O ₃ N ₈ Cl ₂ : Eu ²⁺ and then mixed with agate induction using acetone solvent . At this time, ethanol or pure water can be used as a solvent other than acetone.

Then, the phosphor is synthesized from the mixed raw materials (S130).

Synthesis of the phosphor synthesizes the above-described raw materials in an atmosphere of a mixed gas of hydrogen (H 2) and nitrogen (N 2) at a temperature of about 1300 ° C. to 1500 ° C. The mixing ratio (%) of hydrogen and nitrogen gas can be changed within the range of 5 to 95 to 20 to 80, and the flow rate of the mixed gas can be 1000 cc to 2000 cc per minute.

In addition, a ball mill and a washing process of the phosphors in which mixing and firing are completed are performed (S140), and the phosphors in which the firing is completed are subjected to a ball mill process and a washing process.

The ball mill process is described in detail below.

In order to uniformly mix the precursor, which is a raw material of the phosphor, it is injected into a high energy ball milling machine, a ball and precursor are put into the mill using a high energy ball mill, and the precursors are rotated at a constant speed. It can be pulverized mechanically and mixed uniformly.

When the raw material is pulverized by a high energy ball mill, the particle size decreases to a size of micrometer or less, and the direct contact area of the reaction particles increases, and the temperature rises due to the collision of balls, which may cause a solid phase reaction to the precursor. The temperature inside the mill rises sharply and the raw materials can react with each other.

In the ball mill process, balls made of zirconia, alumina, glass or metal may be used, and the sizes of the balls may be the same or different from each other. Then, the size of the ball, the milling time, the rotation speed per minute of the ball mill, etc. can be adjusted to grind to the size of the target phosphor powder.

As described above, raw materials may be crystallized in the phosphor by mechanical polishing by a ball in a ball mill and chemical reaction by a solid phase reaction, followed by drying at about 70 to 100 ° C. for 10 to 15 hours. You can.

Photoluminescence (PL) and photoluminescence excitation (PLE) of the phosphors of which the manufacturing process was completed were analyzed, and particles were photographed with a scanning electron microscope (SEM).

3 is to compare the PL characteristics of the phosphor according to the embodiment with other phosphors, 4 is to compare the PLE characteristics of the phosphor according to the embodiment with other phosphors, Figure 5 shows an embodiment of the phosphor, Figure 6 represents another phosphor.

In Figure 3, respectively in the matrix using the _{(Sr, Ba) 3 Si 6} O 3 N 8 Cl 2 and active body with ^{Eu 2 + (Sr, Ba)} 3 Si 6 O 3 N 8 Cl 2: Eu 2 + phosphor and _{, (Sr, Ba) 3 Si} 6 O 3 N 8: compares the PL properties of Eu ^{2 +.} 450 when the nanometer wavelengths was used as the excitation light _{source, (Sr, Ba) 3 Si} 6 O 3 N 8 Cl 2: the luminance of _{^{Eu 2 (Sr, Ba) 3}} Si 6 O 3 N 8: Eu 2 + It can be seen that about 40% improvement.

In Figure _{4 (Sr, Ba) 3 Si} 6 O 3 N 8 Cl 2: Eu 2 + _{phosphor, (Sr, Ba) 3 Si} 6 O 3 N 8: compares the PLE properties of Eu ^{2 +.} 300 in the entire region of the wavelength range from nanometers to 500 nanometers _{(Sr, Ba) 3 Si 6} O 3 N 8 Cl 2: This PLE properties of _{^{Eu 2 (Sr, Ba) 3}} Si 6 O 3 N 82: Eu 2 It can be seen that the intensity of light absorbed by each phosphor powder is improved when being excited by light of the same wavelength better than ⁺ .

One embodiment of the phosphor shown in Figure 5, that is, (Sr, Ba) ₃ Si ₆ O ₃ N ₈ Cl ₂ : Eu ^{2 +} is a phosphor of 10 micrometers to 20 micrometers, but contains chlorine (Cl) Therefore, the size of one phosphor is relatively large, where the size means the diameter when the phosphor is spherical and the length of one side when the phosphor is hexahedron. Phosphors shown in FIG. 6, that is, (Sr, Ba) ₃ Si ₆ O ₃ N ₈₂ : Eu ²⁺ include that the size of one phosphor is larger than the embodiment shown in FIG. 5 and the size of each phosphor as a whole is uneven. not.

A plurality of light emitting device packages according to the embodiment may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, or the like, which is an optical member, may be disposed on an optical path of the light emitting device package. Such a light emitting device package, a substrate, and an optical member can function as a light unit.

Yet another embodiment may be implemented as a display device, an indicator device, or a lighting system including the semiconductor light emitting device or the light emitting device package described in the above embodiments, for example, the lighting system may include a lamp, a street lamp. . Hereinafter, a head lamp and a backlight unit will be described as an embodiment of an illumination system in which the above-described light emitting device package is disposed.

5 is a diagram illustrating an embodiment of a head lamp including a light emitting device package.

The light emitted from the light emitting device module 401 in which the light emitting device package is disposed is reflected by the reflector 402 and the shade 403 and then transmitted through the lens 404 to the front of the vehicle body You can head.

Headlamp according to the embodiment, that is, the phosphor containing the Cl to the light emitting element module (401), (Sr, Ba ) 3 Si 6 O 3 N 8 Cl 2: including Eu ^{2 +,} such as 450 nm as compared with other phosphors When the light of the meter wavelength is used as the excitation light source, the luminance can be improved by about 40%, and the PLE characteristic can be improved in the region of the wide wavelength range.

The light emitting device package included in the light emitting device module 401 may include a plurality of light emitting devices, but is not limited thereto.

6 is a diagram illustrating an embodiment of a display device including a light emitting device package.

As shown, the display device 500 according to the present exemplary embodiment includes a light source module, a reflector 520 on the bottom cover 510, and a light disposed in front of the reflector 520 and emitting light emitted from the light source module. In front of the light guide plate 540, the first prism sheet 550 and the second prism sheet 560 disposed in front of the light guide plate 540, and in front of the second prism sheet 560. And a color filter 580 disposed throughout the panel 570.

The light source module comprises a light emitting device package 535 on a circuit board 530. Here, a circuit board (PCB) may be used as the circuit board 530, and the light emitting device package 535 is as described with reference to FIG. 1.

The bottom cover 510 may accommodate components in the display device 500. The reflective plate 520 may be formed as a separate component as shown in the drawing, or may be provided on the rear surface of the light guide plate 540 or on the front surface of the bottom cover 510 with a highly reflective material.

The reflector 520 can be made of a material having a high reflectance and can be used in an ultra-thin shape, and a polyethylene terephthalate (PET) can be used.

The light guide plate 540 scatters the light emitted from the light emitting device package module so that the light is uniformly distributed over the entire screen area of the LCD. Accordingly, the light guide plate 530 is made of a material having a good refractive index and transmittance. The light guide plate 530 may be formed of poly methylmethacrylate (PMMA), polycarbonate (PC), or polyethylene (PE). Also, if the light guide plate 540 is omitted, an air guide display device can be realized.

The first prism sheet 550 is formed on one side of the support film with a translucent and elastic polymer material. The polymer may have a prism layer in which a plurality of steric structures are repeatedly formed. Here, the plurality of patterns may be provided in the stripe type and the valley repeatedly as shown.

In the second prism sheet 560, a direction of a floor and a valley of one side of the supporting film may be perpendicular to a direction of a floor and a valley of one side of the supporting film in the first prism sheet 550. This is for evenly distributing the light transmitted from the light source module and the reflective sheet in all directions of the panel 570.

In this embodiment, the first prism sheet 550 and the second prism sheet 560 constitute an optical sheet, which may be made of other combinations, for example, a microlens array or a combination of a diffusion sheet and a microlens array Or a combination of one prism sheet and a microlens array, or the like.

A liquid crystal display panel may be disposed on the panel 570. In addition to the liquid crystal display panel, another type of display device that requires a light source may be provided.

In the panel 570, a liquid crystal is positioned between glass bodies, and a polarizing plate is placed on both glass bodies to utilize the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

A liquid crystal display panel used in a display device is an active matrix type, and a transistor is used as a switch for controlling a voltage supplied to each pixel.

A color filter 580 is provided on the front surface of the panel 570 so that only the red, green, and blue light is transmitted through the panel 570 for each pixel.

Exemplary backlight unit according to the example, that is, the phosphor containing the Cl to the light emitting device _{package, (Sr, Ba) 3 Si} 6 O 3 N 8 Cl 2: including Eu ^{2 +,} etc., of the 450-nm wavelength than the other phosphor When light is used as the excitation light source, the luminance can be improved by about 40%, and the PLE characteristic can be improved in the region of a wide wavelength range.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100: light emitting device package 110: package body
121 and 122: first and second lead frames 130: light emitting elements
135 conductive bonding layer 140 wire
150 molding part 155 phosphor
400: head lamp 401: light emitting device module
402: Reflector 403: Shade
404: Lens
800: display device 810: bottom cover
820: reflector 830: circuit board module
840: Light guide plate 850, 860: First and second prism sheet
870 panel 880 color filter

Claims (8)

A _{3- x} Si ₆ O ₃ N ₈ Cl _y : B ²⁺ _z (0 <x <3, 0 <y <10, 0.001 <z <0.3, A is an alkaline earth metal element, B is a rare earth element) A wavelength converting material comprising. A _{3-x- z} Si ₆ O ₃ N ₈ Cl _y : B ²⁺ _x (0 <x <3, 0 <y <10, 0.001 <x + z <3, A is an alkaline earth metal element, B is A rare earth element). The method according to claim 1,
A wavelength converting material whose mother is A _{3- x} Si ₆ O ₃ N ₈ Cl _y and the activator is B ²⁺ _z . The method of claim 2,
A wavelength converting material whose mother is A _{3-x- z} Si ₆ O ₃ N ₈ Cl _y and the activator is B ^{2+ x} _x . 3. The method according to claim 1 or 2,
A wavelength converting material consisting of phosphor powder having a size of 10 to 20 micrometers. The method according to claim 1 or 2,
A is at least one of Be, Mg, Ca, Sr, Ba and Ra. The method according to claim 1 or 2,
B is at least one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The method according to claim 1 or 2,
Wherein A is (Sr, Ba) and B is Eu.

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