KR20120016696A - Light emitting device package and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A light emitting device package and a method for manufacturing the same are provided to improve light extraction efficiency by forming an incline around a light emitting device. CONSTITUTION: A light emitting structure(120) including a first conductivity type semiconductor layer(122), an active layer(124), and a second conductivity type semiconductor layer(126) is formed on a substrate. An ohmic layer(140) and a reflecting layer(150) are formed on the light emitting structure. The conductivity type supporting substrate(170) is formed on the reflecting layer. A first electrode(180) is formed on the first conductivity type semiconductor layer. A mask(190) is arranged on the first electrode.

Description

Light emitting device package and method for manufacturing the same

The embodiment relates to a light emitting device package and a method of manufacturing the same.

A light emitting device such as a light emitting diode or a laser diode using a group 3-5 or 2-6 compound semiconductor material of a semiconductor can realize various colors such as red, green, blue, and ultraviolet rays by developing thin film growth technology and device materials. Efficient white light can be realized by using fluorescent materials or combining colors.

With the development of these technologies, LED backlights, fluorescent lamps or incandescent bulbs, which replace not only display elements but also cold cathode fluorescent lamps (CCFLs), which form the backlight of optical communication means, transmission modules, and liquid crystal display (LCD) displays. Applications are expanding to white light emitting diode lighting devices, automotive headlights and traffic lights that can be substituted for them.

Here, in the structure of the LED, since the P electrode, the active layer, and the N electrode are sequentially stacked on the substrate, and the substrate and the N electrode are wire bonded, currents may be energized with each other.

At this time, when a current is applied to the substrate, since current is supplied to the P electrode and the N electrode, holes (+) are emitted from the P electrode to the active layer, and electrons (-) are emitted from the N electrode to the active layer. Therefore, as the holes and electrons are combined in the active layer, the energy level is lowered, and the energy emitted at the same time as the energy level is lowered is emitted in the form of light.

The embodiment is intended to easily form the phosphor layer of the light emitting device package.

Embodiments include a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; First and second electrodes on the first conductive semiconductor layer and the second conductive semiconductor layer, respectively; And a phosphor layer including a silicon-based polymer and a phosphor powder on the light emitting structure.

Here, the phosphor layer may not be formed around the light emitting structure.

In addition, the phosphor layer may have a constant thickness.

Another embodiment includes growing a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer; Providing a first electrode and a second electrode on the first conductive semiconductor layer and the second conductive semiconductor layer, respectively; Applying a phosphor material including PDMS and phosphor powder on the second conductivity type semiconductor layer; And dicing the phosphor material, the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer.

Here, the phosphor material may be applied by spin coating.

The phosphor material may be spin coated at 2000-3000 rpm.

In addition, the method of manufacturing the light emitting device package may further include the step of heat-treating the phosphor material at 200 ~ 300 ℃.

The light emitting device package and the method of manufacturing the same according to the embodiment may uniformly apply the phosphor layer to the plurality of packages.

1A to 1I illustrate an embodiment of a method of manufacturing a light emitting device package.

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

In the description of the above embodiments, each layer (region), region, pattern or structures may be "on" or "under" the substrate, each layer (layer), region, pad or pattern. In the case of what is described as being formed, "on" and "under" include both being formed "directly" or "indirectly" through another layer. In addition, the criteria for the top or bottom of each layer will be described with reference to the drawings.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not necessarily reflect the actual size.

1A to 1I illustrate an embodiment of a method of manufacturing a light emitting device package. Hereinafter, an embodiment of a method of manufacturing a light emitting device package will be described with reference to FIGS. 1A to 1I.

First, the substrate 110 is prepared as shown in FIG. 1A. The substrate 110 may include a conductive substrate or an insulating substrate, for example, at least one of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ 0 ₃ . Can be used. An uneven structure may be formed on the substrate 110, but is not limited thereto. Impurities on the surface may be removed by wet cleaning the substrate 110.

In addition, a light emitting structure 120 including a first conductive semiconductor layer 122, an active layer 124, and a second conductive semiconductor layer 126 may be formed on the substrate 110.

In this case, a buffer layer (not shown) may be grown between the light emitting structure 120 and the substrate 110 to mitigate the difference in lattice mismatch and thermal expansion coefficient of the material. The material of the buffer layer may be formed of at least one of Group III-V compound semiconductors such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. An undoped semiconductor layer may be formed on the buffer layer, but is not limited thereto.

In addition, the light emitting structure 120 may be grown by vapor deposition such as metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and hydraulic vapor phase epitaxy (HVPE).

The first conductivity type semiconductor layer 122 may be implemented as a group III-V compound semiconductor doped with a first conductivity type dopant, and the first conductivity type semiconductor layer 122 is an N-type semiconductor layer. The first conductive dopant may be an N-type dopant and may include Si, Ge, Sn, Se, or Te, but is not limited thereto.

The first conductive semiconductor layer 122 may be formed of a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). It may include. The first conductive semiconductor layer 122 may be formed of any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP. have.

The first conductivity type semiconductor layer 122 may be formed using a chemical vapor deposition method (CVD), molecular beam epitaxy (MBE), sputtering or hydroxide vapor phase epitaxy (HVPE). For example, the first conductive semiconductor layer 122 includes n-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and silicon (Si) in the chamber. Silane gas (SiH ₄ ) may be injected to form an N-type GaN layer.

The active layer 124 has an energy band inherent in the active layer (light emitting layer) material because electrons injected through the first conductive semiconductor layer 122 and holes injected through the second conductive semiconductor layer 126 formed thereafter meet each other. It is a layer that emits light with energy determined by.

The active layer 124 may be formed of at least one of a single quantum well structure, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure. For example, the active layer 124 may be formed by injecting trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) to form a multi-quantum well structure. It is not limited to this.

The well layer / barrier layer of the active layer 124 may be formed of one or more pair structures of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAS) / AlGaAs, GaP (InGaP) / AlGaP. But it is not limited thereto. The well layer may be formed of a material having an energy band gap lower than the energy band gap of the barrier layer.

A conductive cladding layer (not shown) may be formed on or under the active layer 124. The conductive clad layer may be formed of an AlGaN-based semiconductor, and may have a higher band gap than the band gap of the active layer 124.

The second conductive type semiconductor layer 126 is a second conductive type dopant is doped III-V compound semiconductor, for example _{-5, In x Al y Ga 1 -x-} y N (0≤x≤1, 0≤y≤ And 1, 0 ≦ x + y ≦ 1). When the second conductive semiconductor layer 126 is a P-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, Ba, and the like as a P-type dopant.

The second conductivity type semiconductor layer 126 is a bicetyl cyclone containing p-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and magnesium (Mg) in the chamber. Pentadienyl magnesium (EtCp ₂ Mg) {Mg (C ₂ H ₅ C ₅ H ₄ ) ₂ } may be injected to form a p-type GaN layer, but is not limited thereto.

In an embodiment, the first conductive semiconductor layer 122 may be a P-type semiconductor layer, and the second conductive semiconductor layer 126 may be an N-type semiconductor layer. In addition, an N-type semiconductor layer (not shown) may be formed on the second conductive semiconductor layer 126 when the semiconductor having a polarity opposite to that of the second conductive type, for example, the second conductive semiconductor layer is a P-type semiconductor layer. have. Accordingly, the light emitting structure 120 may be implemented as any one of an N-P junction structure, a P-N junction structure, an N-P-N junction structure, and a P-N-P junction structure.

In addition, a first electrode and a second electrode may be provided on the first conductive semiconductor layer 122 and the second conductive semiconductor layer 126, respectively, and include chromium (Cr), nickel (Ni), and gold (Au). , Aluminum (Al), titanium (Ti), platinum (Pt) may be made of any one metal or an alloy of the metals.

As shown in FIG. 1B, an ohmic layer 140 and a reflective layer 150 are formed on the light emitting structure 120.

The ohmic layer 140 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), and indium gallium tin (IGTO). oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf It may be formed to include at least one of, and is not limited to these materials.

In addition, the reflective layer 150 may be formed of a metal layer including aluminum (Al), silver (Ag), or an alloy containing Al or Ag. Aluminum or silver may effectively reflect light generated from the active layer 124 to greatly improve the light extraction efficiency of the light emitting device.

In addition, as illustrated in FIG. 1C, the conductive support substrate 170 may be formed on the reflective layer 150. The conductive support substrate 170 may be copper (Cu), gold (Au), copper alloy (Cu Alloy), nickel (Ni-nickel), copper-tungsten (Cu-W), carrier wafers (eg, GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O _3, etc.) may be optionally included. The conductive support substrate 170 may be formed using an electrochemical metal deposition method or a bonding method using a eutectic metal.

In addition, for the coupling between the reflective layer 150 and the conductive support substrate 170, the above-described reflective layer 150 functions as a bonding layer, or may use nickel (Ni) or gold (Au) or the like. As shown, the bonding layer 160 may be formed. The conductive support substrate 170 having the above-described structure may act as the second electrode.

Then, the substrate 110 is removed as shown in FIG. 1D. The substrate 110 may be removed by a laser lift off (LLO) method using an excimer laser or the like, or may be a method of dry and wet etching.

When the substrate 110 is removed by a laser lift-off method, when the excimer laser light having a predetermined wavelength is irradiated onto the substrate 110, the substrate 110 and the first conductivity type are irradiated. Thermal energy is concentrated on the interface of the semiconductor layer 122, so that the interface of the first conductivity-type semiconductor layer 122 is separated into gallium and nitrogen molecules, and the substrate 110 is instantaneously separated at the portion where the laser light passes.

1E, a first electrode 180 is formed on the first conductivity type semiconductor layer 122. The first electrode 180 is made of any one metal selected from chromium (Cr), nickel (Ni), gold (Au), aluminum (Al), titanium (Ti), and platinum (Pt) or an alloy of the metals. .

In addition, a mask 190 may be disposed on the first electrode 180. The mask 190 is to be connected to the electrode on the package body by wire bonding and the like so that the first electrode 180 is not covered in the phosphor coating process described below.

Although not shown, a PEC method or a mask is formed on the surface of the first conductivity-type semiconductor layer 122 and then irregularities are formed through etching of a fine size, thereby reducing the surface area of the first conductivity-type semiconductor layer 122. Can be increased.

And, as shown in Figure 1e to prepare a phosphor material, it is made by mixing the phosphor powder 195 in PDMS (Polydimethylsiloxane). That is, in the active layer of the light emitting device, electrons emitted from the n-type conductive semiconductor layer and holes emitted from the p-type conductive semiconductor layer combine to emit light. In the active layer, blue light may be emitted. The white can be realized by enclosing.

That is, blue light emitted from the active layer excites a yellow phosphor, and yellow light emitted from the yellow phosphor may implement white light together with blue light. At this time, YAG: Ce, TAG: Ce or silicate phosphor may be used as the yellow phosphor material. The phosphor powder 195 including the above-mentioned material is mixed in polydimethylsiloxane (PDMS). In this case, the weight of the phosphor powder 195 may be 5% to 20% of the weight of the phosphor material.

At this time, if the PDMS (Polydimethylsiloxane) is used, the precipitation problem that occurs when using a conventional epoxy or the like may not occur. If the weight ratio of the phosphor powder is too small, it is not sufficient to convert the light wavelength, and if too large, the luminous efficiency of the light emitting device may be reduced. The polydimethylsiloxane (PDMS) is an embodiment of a silicon-based polymer, and other silicon-based polymers may be used.

In addition, as illustrated in FIG. 1G, a phosphor material is coated on the first conductive semiconductor layer 122 so that the phosphor material completely covers the upper portion of the light emitting device. In this case, the phosphor material may be applied through a mechanism such as an eyedropper.

In addition, as shown in FIG. 1H, the phosphor material may be spin coated at about 2,000 to 3,000 rpm. Through the above-described spin coating process, the phosphor material may be applied to the light emitting structure 120 with a uniform thickness, and the above-described spin coating may last at least 30 seconds. In addition, the phosphor material may be applied onto the light emitting structure by a process such as dip coating, spray coating, screen printing, or the like. In addition, as shown, the phosphor material may be advantageous in a process such as wire bonding, which will be described later, when a portion of the first electrode 180 is coated to be exposed.

In order to cure the phosphor layer, heat treatment may be performed at about 200 to 300 ° C. Then, after the coating and curing step of the phosphor, dicing is performed for each device unit to separate the light emitting device. At this time, since the phosphor material is applied, spin coated and cured before being separated into each light emitting device, a phosphor layer having a uniform thickness can be formed in each light emitting device in one step.

In addition, the wire 190 may be bonded to the first electrode 180 by removing the mask 190 on the first electrode 180 after the dicing process.

In addition, a passivation layer (not shown) may be formed on the side surface of the light emitting structure 120 to protect the light emitting structure 120. The light emitting structure 120 may be formed before or after the forming of the phosphor layer. have.

The light emitting device package is completed by connecting to a lead frame of the package by a wire bonding method.

The completed light emitting device package is shown in FIG.

As illustrated, the light emitting device package according to the embodiment may include a package body 220, a first electrode layer 211 and a second electrode layer 212 provided on the package body 220, and the package body 220. The light emitting device 200 according to the exemplary embodiment is installed and electrically connected to the first electrode layer 211 and the second electrode layer 212.

Here, the light emitting device 200 is a light emitting device manufactured according to the above process. Here, the phosphor layer may not be applied to the light emitting structure (see FIG. 1H, 120) of the light emitting device 200. In the case of the vertical light emitting device, since the light emitted to the side is very small, the phosphor layer is disposed on the side of the light emitting structure. Even if this is not formed, it is possible to implement the color temperature in the light emitting device package.

The side surface of the light emitting device 200 may be exposed to the outside air on the package body 220, but as shown in FIG. 1I, the lens 240 surrounds the light emitting device 200 together with the filler and protects the device. And light exit angle.

The package body 220 may include a silicon material, a synthetic resin material, or a metal material. An inclined surface may be formed around the light emitting device 200 to increase light extraction efficiency.

The first electrode layer 211 and the second electrode layer 212 are electrically separated from each other, and provide power to the light emitting device 200. In addition, the first electrode layer 211 and the second electrode layer 212 can increase the light efficiency by reflecting the light generated from the light emitting device 200, the heat generated from the light emitting device 200 May also act as a drain.

The light emitting device 200 may be installed on the package body 220 or on the first electrode layer 211 or the second electrode layer 212.

The light emitting device 200 may be electrically connected to the first electrode layer 211 and the second electrode layer 212 by any one of a wire method, a flip chip method, or a die bonding method.

The light emitting device package may mount at least one of the light emitting devices of the above-described embodiments as one or more, but is not limited thereto.

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. The light emitting device package, the substrate, and the optical member may function as a light unit. 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 and a street lamp. .

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

In addition, the above description has been made with reference to the embodiment, which is merely an example, and is not intended to limit the present invention. Those skilled in the art to which the present invention pertains will be illustrated as above without departing from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

100 substrate 120 light emitting structure
122: first conductive semiconductor layer 124: active layer
126: second conductive semiconductor layer 130: phosphor layer
200 light emitting element 211 first electrode layer
212: second electrode layer 220: package body
240: filling material

Claims (7)

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer;
First and second electrodes on the first conductive semiconductor layer and the second conductive semiconductor layer, respectively; And
On the light emitting structure, a light emitting device package comprising a phosphor layer containing a silicon-based polymer and phosphor powder. The method of claim 1,
The phosphor layer is not formed around the light emitting structure package. The method of claim 1,
The phosphor layer has a constant thickness light emitting device package. Growing a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer;
Providing a first electrode and a second electrode on the first conductive semiconductor layer and the second conductive semiconductor layer, respectively;
Applying a phosphor material including PDMS and phosphor powder on the second conductivity type semiconductor layer; And
And dicing the phosphor material, the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer. The method of claim 4, wherein
The phosphor material is a method of manufacturing a light emitting device package is applied by spin coating. The method of claim 5, wherein
The phosphor material is spin-coated at 2000 ~ 3000 rpm manufacturing method of the light emitting device package. The method of claim 4, wherein
The method of manufacturing a light emitting device package further comprising the step of heat-treating the phosphor material at 200 ~ 300 ℃.

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