KR20190133314A - Vertical-cavity surface-emitting laser package and automatic focusing device - Google Patents

Abstract

A surface light emitting laser package capable of protecting eyes of a user comprises: a surface light emitting laser element disposed on a substrate; a housing disposed around the surface light emitting laser element; a diffusion unit disposed on the surface light emitting laser element; and a wavelength limiting member disposed on the surface light emitting laser element. The surface light emitting laser element may emit light with a first wavelength band. The wavelength limiting member may block wavelength outside the first wavelength band.

Description

Surface-emitting laser package and automatic focusing device

Embodiments relate to surface emitting laser packages and autofocus devices.

A semiconductor device including a compound such as GaN, AlGaN, etc. has many advantages, such as having a wide and easy-to-adjust band gap energy, and can be used in various ways as a light emitting device, a light receiving device, and various diodes.

In particular, surface light emitting laser packages using semiconductors of Group 3-5 or Group 2-6 compound semiconductor materials may be employed in optical communications, sensors, auto focus devices, proximity sensors, auto focus devices.

When heat is generated by the over-operation or malfunction of the driving circuit for driving the surface light emitting laser package, the wavelength band of the light of the surface light emitting laser element of the surface light emitting laser package can be shifted to a longer wavelength range. Since the long wavelength range may damage the eyes of the user, a solution for this situation is required.

The embodiment aims to solve the above and other problems.

Another object of the embodiment is to provide a surface light emitting laser package and an autofocusing apparatus having a novel structure.

Another object of the embodiment is to provide a surface light emitting laser package and an autofocusing device that can protect the eyes of the user.

According to an aspect of the embodiment to achieve the above or another object, the surface light emitting laser package, the substrate; A surface light emitting laser element disposed on the substrate; A housing disposed around the surface light emitting laser element; A diffusion unit disposed on the surface light emitting laser element; And a wavelength limiting member disposed on the surface light emitting laser element. The surface light emitting laser device may emit light having a first wavelength band. The wavelength limiting member may block a wavelength outside the first wavelength band of the light.

According to another aspect of an embodiment, the auto focus device comprises: the surface light emitting laser package; And it may include a light receiving unit for receiving the reflected light of the light emitted from the surface light emitting laser package.

The effects of the surface light emitting laser package and the autofocusing apparatus according to the embodiment are as follows.

According to at least one of the embodiments, the wavelength limiting member is provided on the enlarged portion and the housing, thereby blocking the light having the second wavelength band emitted from the surface light emitting laser element by abnormal operation so that the user's eyes are not damaged. The advantage is that it can be avoided.

According to at least one of the embodiments, the wavelength limiting member is attached to the housing as well as the diffusing portion, thereby preventing the deviation of the diffusing portion so that the light of the surface light emitting laser element is directly provided to the outside to prevent damaging the eyes of the user. There is an advantage that it can.

Further scope of the applicability of the embodiments will become apparent from the detailed description below. However, various changes and modifications within the spirit and scope of the embodiments can be clearly understood by those skilled in the art, and therefore, specific embodiments, such as the detailed description and the preferred embodiments, are to be understood as given by way of example only.

1 is a cross-sectional view showing a surface light emitting laser package according to the first embodiment.
2 is a plan view of the surface light emitting laser device according to the first embodiment.
3 is a cross-sectional view taken along line II ′ of the surface light emitting laser device according to the first embodiment shown in FIG. 2.
4 shows a state in which the peak wavelength of light is shifted according to the current.
5 shows the change of bandgap energy with temperature.
6 shows the peak wavelength according to the wavelength of the wavelength limiting member.
7 is a cross-sectional view showing a surface light emitting laser package according to the second embodiment.
8 is a sectional view showing a surface light emitting laser package according to the third embodiment.
9 is a sectional view showing a surface light emitting laser package according to the fourth embodiment.
10 is a perspective view of a mobile terminal to which an autofocusing apparatus including a surface light emitting laser package according to an embodiment is applied.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same or similar components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or mixed in consideration of ease of specification, and do not have distinct meanings or roles from each other. In addition, in describing the embodiments disclosed herein, when it is determined that the detailed description of the related known technology may obscure the gist of the embodiments disclosed herein, the detailed description thereof will be omitted. In addition, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, but are not limited to the technical spirit disclosed herein by the accompanying drawings, all changes included in the spirit and scope of the embodiments, It should be understood to include equivalents and substitutes.

1 is a cross-sectional view showing a surface light emitting laser package according to the first embodiment.

Referring to FIG. 1, the surface light emitting laser package 100 according to the first embodiment may provide a substrate 110.

Substrate 110 may support all components disposed on substrate 110. For example, the substrate 110 may support the surface light emitting laser device 200, the housing 130, the diffusion unit 140, and the wavelength limiting member 150 disposed thereon. The surface light emitting laser device 200, the housing 130, the diffusion unit 140, the wavelength limiting member 150, and the substrate 110 may be modular modules. One or more such modules may be mounted on the circuit board 160.

 The substrate 110 may include a material having high thermal conductivity. The substrate 110 may be formed of a material having a good heat dissipation property so as to efficiently radiate heat generated from the surface light emitting laser device 200 to the outside. The substrate 110 may include an insulating material.

For example, the substrate 110 may include a ceramic material. The substrate 110 may include a low temperature co-fired ceramic (LTCC) or a high temperature co-fired ceramic (HTCC) that is co-fired.

In addition, the substrate 110 may include a metal compound. The substrate 110 may include a metal oxide having a thermal conductivity of 140 W / mK or more. For example, the substrate 110 may include aluminum nitride (AlN) or alumina (Al 2 O 3).

As another example, the substrate 110 may include a resin-based insulating material. The substrate 110 may be made of a silicone resin, an epoxy resin, a thermosetting resin including a plastic material, or a high heat resistant material.

The substrate 110 may include a conductive material. When the substrate 110 is made of a conductive material, such as a metal, an insulating layer 27 for electrical insulation between the substrate 110 and the surface light emitting laser device 200 may be provided.

The surface light emitting laser package 100 according to the first embodiment may provide the surface light emitting laser device 200.

The surface light emitting laser device 200 may be disposed on the substrate 110. The surface light emitting laser device 200 may generate a laser beam and emit the laser beam in a direction perpendicular to the upper surface of the surface light emitting laser device 200. The surface light emitting laser device 200 may emit, for example, a laser beam having an angle of view of 15 ° to 25 ° in an upward direction. The surface light emitting laser device 200 may include a plurality of emitters (E1, E2, E3, and E4 of FIG. 2) that emit circular beams. An example of the surface light emitting laser element 200 will be described later.

The surface light emitting laser package 100 according to the first embodiment may provide a first electrode 181 and a second electrode 182.

The first electrode 181 and the second electrode 182 may be disposed on the substrate 110. The first electrode 181 and the second electrode 182 may be spaced apart from each other on the substrate 110.

One electrode of the first electrode 181 and the second electrode 182 may be disposed around the surface light emitting laser device 200.

The surface light emitting laser device 200 may be disposed on the first electrode 181. In this case, the second electrode 182 may be disposed around the surface light emitting laser device 200.

The surface light emitting laser device 200 may be provided on the first electrode 181 by, for example, a die bonding method. The surface light emitting laser device 200 may be electrically connected to the second electrode 182. For example, the surface light emitting laser device 200 and the second electrode 182 may be electrically connected by the wire 191. The surface light emitting laser device 200 may be electrically connected to the second electrode 182 by a plurality of wires. The surface light emitting laser device 200 may be electrically connected to the second electrode 182 by a wire 191.

The number and connection positions of the wires connecting the surface light emitting laser device 200 and the second electrode 182 are the size of the surface light emitting laser device 200 or the degree of current diffusion required in the surface light emitting laser device 200. Or the like.

The surface light emitting laser package 100 according to the first embodiment may provide a first bonding portion 183 and a second bonding portion 184.

The first bonding part 183 and the second bonding part 184 may be disposed under the substrate 110. For example, first and second recesses spaced apart from each other are formed on the bottom surface of the substrate 110, a first bonding portion 183 is disposed in the first recess, and a second bonding portion 185 in the second recess. Can be deployed

For example, a lower surface of the first bonding unit 183 and a lower surface of the second bonding unit 184 may be in surface contact with a signal line (not shown) of the circuit board 160 to be electrically connected to each other. The substrate 110 may be referred to as a first substrate, and the circuit board 160 may be referred to as a second substrate.

The first bonding part 183 and the second bonding part 184 may be spaced apart from each other under the substrate 110. The first bonding part 183 and the second bonding part 184 may have a circular pad but are not limited thereto.

The first bonding part 183 may be disposed on the bottom surface of the substrate 110. The first bonding part 183 may be electrically connected to the first electrode 181. The first bonding unit 183 may be electrically connected to the first electrode 181 through the first connection line 185. For example, the first connection line 185 may be disposed in the first via hole provided in the substrate 110. The first bonding part 183 and the first connection wiring 185 may be integrally formed using the same metal material.

The second bonding part 184 may be disposed on the bottom surface of the substrate 110. The second bonding part 184 may be electrically connected to the second electrode 182. The second bonding unit 184 may be electrically connected to the second electrode 182 through the second connection line 186. For example, the second connection line 186 may be disposed in the second via hole provided in the substrate 110. The second bonding part 184 and the second connection wiring 186 may be integrally formed using the same metal material.

For example, the first connection wire 185 and the second connection wire 186 may include tungsten (W), but are not limited thereto. Tungsten (W) may be melted at a high temperature of 1000 ° C. or higher, injected into the first and second via holes, and cured to form a first connection line 185 and a second connection line 186. A portion of the tungsten (W) may be cured under the substrate 110 to be formed of the first and second bonding portions 183 and 184, but is not limited thereto.

According to the first embodiment, driving power may be provided to the surface light emitting laser device 200 through the circuit board 160.

In the surface light emitting laser package 100 according to the first embodiment described above, the surface light emitting laser device 200 is connected to the first electrode 181 by a die bonding method and wire bonded to the second electrode 182. It has been described on the basis of the case where the connection is made in a manner.

However, the way in which the driving power is supplied to the surface light emitting laser device 200 may be variously modified and applied. For example, the surface light emitting laser device 200 may be electrically connected to the first electrode 181 and the second electrode 182 by a flip chip bonding method. In addition, the surface light emitting laser device 200 may be electrically connected to both the first electrode 181 and the second electrode 182 by a wire bonding method.

The surface light emitting laser package 100 according to the first embodiment may provide a housing 130. The housing 130 may be disposed on the substrate 110. The housing 130 may be disposed along the peripheral area of the substrate 100. For example, the substrate 110 may include a first region (center region) and a second region (peripheral region) surrounding the first region. In this case, the surface light emitting laser device 200 may be disposed on a portion of the first region of the substrate 110, and the housing 130 may be disposed on the second region of the substrate 120. The second electrode 182 may be positioned between the first electrode 181 and the housing 130 on the substrate 110. The housing 130 may be disposed around the surface light emitting laser device 200. The outer surface of the housing 130 may coincide with the outer surface of the substrate 110 in a vertical line.

The height of the housing 130 may be greater than the height of the surface light emitting laser device 200. The housing 130 may include a material having high thermal conductivity. The housing 130 may be provided with a material having a good heat dissipation property so that the heat generated from the surface light emitting laser device 200 may be efficiently emitted to the outside. The housing 130 may include an insulating material.

For example, the housing 130 may include a ceramic material. The housing 130 may include a low temperature co-fired ceramic (LTCC) or a high temperature co-fired ceramic (HTCC) that is co-fired.

For example, the housing 130 may include a metal compound. The housing 130 may include a metal oxide having a thermal conductivity of 140 W / mK or more. For example, the housing 130 may include aluminum nitride (AlN) or alumina (Al 2 O 3).

For example, the housing 130 may include a resin-based insulating material. Specifically, the housing 130 may be made of a silicone resin, an epoxy resin, a thermosetting resin including a plastic material, or a high heat resistant material.

The housing 130 may be made of a conductive material such as metal.

For example, the housing 130 may include the same material as the substrate 110. When the housing 130 is formed of the same material as the substrate 110, the housing 130 may be integrally formed with the substrate 110.

In addition, the housing 130 may be formed of a material different from that of the substrate 110. Substrate 110 may be referred to as a housing. In this case, the substrate 110 may be referred to as a first housing, and the housing 130 may be referred to as a second housing. Alternatively, the housing 130 may be referred to as a substrate. In this case, the substrate 110 may be referred to as a first substrate, and the housing 130 may be referred to as a second substrate.

According to the first embodiment, the substrate 110 and the housing 130 may be made of a material having excellent heat radiation characteristics. Accordingly, heat generated from the surface light emitting laser device 200 may be effectively released to the outside.

According to the first embodiment, when the substrate 110 and the housing 130 are provided and coupled as separate components, an adhesive layer may be provided between the substrate 110 and the housing 130.

For example, the adhesive layer may include an organic material. The adhesive layer may include an epoxy-based resin. In addition, the adhesive layer may include a silicone-based resin.

On the other hand, a step may be provided in contact with the inner side in the upper region of the housing 130. For example, a recess region 142 may be provided in an upper region of the housing 130. By way of example, the width and / or depth of the recessed area 142 may be provided in hundreds of micrometers.

The surface light emitting laser package 100 according to the first embodiment may provide the diffuser 140.

The diffusion unit 140 may be disposed on the surface light emitting laser device 200. The diffusion unit 140 may be spaced apart from the surface light emitting laser device 200. The diffusion unit 140 may be disposed in the recess region 142 of the housing 130. The diffusion part 140 may be supported by the recess region 142 of the housing 130.

An adhesive layer (not shown) may be provided between the diffusion portion 140 and the recess region 142 of the housing 130. For example, the adhesive layer may be provided on the bottom surface and the side surface of the diffusion portion 140 in contact with the inner surface of the recess region 142. For example, the adhesive layer may include an organic material. The adhesive layer may include an epoxy-based resin. Alternatively, the adhesive layer may include a silicone resin.

The diffusion unit 140 may extend the angle of view of the laser beam emitted from the surface light emitting laser device 200.

The diffusion unit 140 may include an anti-reflective function. For example, the diffuser 140 may include an antireflection layer disposed on one surface of the diffuser 140 facing the surface light emitting laser device 200. The antireflective layer may be formed separately from the diffusion part 140. The diffusion unit 140 may include an antireflection layer disposed on a bottom surface of the diffuser 140 facing the surface light emitting laser device 200. The anti-reflective layer may prevent the laser beam incident from the surface light emitting laser device 200 from being reflected from the surface of the diffuser 140 and transmit the light into the diffuser 140 to improve light loss due to reflection.

The antireflective layer may be formed of, for example, an antireflective coating film and attached to the surface of the diffusion part 140. The antireflective layer may be formed on the surface of the diffusion part 140 by spin coating or spray coating. As an example, the antireflective layer may be formed of a single layer or multiple layers including at least one of a group comprising TiO 2, SiO 2, Al 2 O 3, Ta 2 O 3, ZrO 2, MgF 2.

The surface light emitting laser package 100 according to the first embodiment may provide a circuit board 160 including at least one signal line. The substrate 110 including the surface light emitting laser device 200 may be mounted on the circuit board 160. For example, the circuit board 180 may include first and second signal lines. In this case, the first bonding part 183 disposed below the substrate 100 is electrically connected to the first signal line of the circuit board 160, and is disposed below the substrate to be connected to the first bonding part 183. The second bonding parts 184 spaced apart in the horizontal direction may be electrically connected to the second signal line of the circuit board 160.

As described above, the substrate 110 and the housing 130 may be manufactured by a wafer level package process. According to the first embodiment, the diffusion 140 may also be attached onto the housing 130 by a wafer level package process.

That is, after the surface light emitting laser device 200 and the housing 130 are attached to the substrate 110 at the wafer level, and the diffusion unit 140 is attached to the housing 130, a cutting method by dicing or the like is performed. A plurality of surface light emitting laser packages in which the surface light emitting laser device 200, the housing 130, and the diffusion unit 140 are coupled to the substrate 110 may be provided.

As such, when the surface light emitting laser package 100 including the substrate 110, the housing 130, and the diffusion 140 is manufactured by a wafer level package process, the outer surface and the housing ( The outer surface of 130 may be disposed on the same plane. That is, there is no step between the outer surface of the substrate 110 and the outer surface of the housing 130.

According to the first embodiment, there is no step between the outer surface of the substrate 110 and the outer surface of the housing 130, so that the damage caused by moisture permeation and external friction due to the step structure in the conventional surface light emitting laser package, etc. Can be fundamentally prevented.

According to the first embodiment, the substrate 110 and the housing 130 are manufactured by a wafer level package process, and the diffusion unit 140 may be attached onto the housing 130 in a separate process.

According to the first embodiment, the diffusion part 140 may be stably fixed to the housing 130 by an adhesive layer provided between the diffusion part 140 and the recess region 142 of the housing 130.

Hereinafter, the surface light emitting laser device 200 will be described in detail. 2 is a plan view of the surface light emitting laser device according to the first embodiment, and FIG. 3 is a cross-sectional view taken along the line II ′ of the surface light emitting laser device according to the first embodiment shown in FIG. 2.

The surface light emitting laser device 200 according to the first embodiment may emit light having a peak wavelength of 940 nm and a full width at half maximum (FWHM) of about 2 nm, for example. This light may have a wavelength band of, for example, 940 ± 2 nm, but is not limited thereto.

2, the surface light emitting laser device 200 according to the first embodiment may include a light emitting area 245 and a non-light emitting area 247. The non-light emitting area 247 is a region where the laser beam is not emitted, and for example, the pad electrode 290 may be disposed. The light emitting region 245 is a region where the laser beam is emitted, and for example, the light emitting structure E may be disposed.

The light emitting structure E may include a plurality of emitters E1, E2, E3, and E4. Each emitter E1, E2, E3, E4 may be spaced apart from each other. The light emitting structure E may include a second electrode 280. The emission area 245 may include a first area and a second area. The first area may be defined in plural, and an area between the first areas may be defined as a second area. In this case, each of the emitters E1, E2, E3, and E4 may be disposed in the first region, and the second electrode 280 may be disposed in the second region. Each emitter E1, E2, E3, E4 may be surrounded by a second electrode 280. The second electrode 280 may be formed integrally with the pad electrode 290, but is not limited thereto. The second electrode 280 may extend from the pad electrode 290 to the light emitting region 245 and be disposed in the light emitting region 245. As will be described later, the second electrode 280 may electrically connect the plurality of emitters E1, E2, E3, and E4 to the pad electrode 290.

Referring to FIG. 3, the surface light emitting laser device 200 according to the first embodiment may include a first electrode 215, a substrate 210, a first reflective layer 220, a cavity region 230, and an aperture 241. ), An insulating region 242, a second reflective layer 250, a second electrode 280, a passivation layer 270, and a pad electrode 290.

The cavity region 230 may include an active layer (not shown) and a cavity (not shown), which will be described below. The insulating region 242 includes a first insulating region 242a disposed in the first emitter E1, a second insulating region 242b and a third emitter E3 disposed in the second emitter E2. It may include a third insulating region 242c disposed in, but is not limited thereto.

<Substrate, first electrode>

In the first embodiment, the substrate 210 may be a conductive substrate or a non-conductive substrate. In the case of using a conductive substrate, a metal having excellent electrical conductivity may be used, and since the heat generated when operating the surface light emitting laser device 200 should be sufficiently dissipated, a GaAs substrate having a high thermal conductivity, a metal substrate, or silicon ( Si) substrate etc. can be used.

In the case of using a non-conductive substrate, an AlN substrate, a sapphire (Al ₂ O ₃ ) substrate, or a ceramic substrate may be used.

In an embodiment, the first electrode 215 may be disposed below the substrate 210, and the first electrode 215 may be disposed in a single layer or multiple layers with a conductive material. For example, the first electrode 215 may be a metal and include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). As a single layer or a multi-layer structure can be formed to improve the electrical characteristics to increase the light output.

<1st reflective layer>

The first reflective layer 220 may be disposed on the substrate 210.

The first reflective layer 220 may be doped with a first conductivity type dopant. For example, the first conductivity type dopant may include an n type dopant such as Si, Ge, Sn, Se, Te, or the like.

In addition, the first reflective layer 220 may include a gallium-based compound, for example, AlGaAs, but is not limited thereto. The first reflective layer 220 may be a distributed bragg reflector (DBR). For example, the first reflective layer 220 may have a structure in which a first layer and a second layer made of materials having different refractive indices are alternately stacked at least once.

The first layer and the second layer may include AlGaAs, and in detail, may be formed of a semiconductor material having a compositional formula of Al _x Ga _(1-x) As (0 <x <1). Herein, when Al in the first layer or the second layer increases, the refractive index of each layer may decrease, and when Ga increases, the refractive index of each layer may increase.

The thickness of each of the first layer and the second layer is λ / 4n, λ may be a wavelength of light generated in the cavity region 230, and n may be a refractive index of each layer with respect to light of the above-described wavelength. Here, λ may be 650 to 980 nm, n may be the refractive index of each layer. The first reflective layer 220 having such a structure may have a reflectance of 99.999% for light in a wavelength region of about 940 nm.

The thickness of the first layer and the second layer may be determined according to respective refractive indices and the wavelength λ of the light emitted from the cavity region 230.

<Cavity area, insulation area, aperture>

In the first embodiment, the cavity region 230, the insulating region 242, and the aperture 241 may be disposed on the first reflective layer 220. In detail, the cavity region 230 may be disposed on the first reflective layer 220, and the insulating region 242 and the aperture 241 may be disposed on the cavity region 230.

The cavity region 230 may include an active layer (not shown), a first cavity (not shown) disposed under the active layer, and a second cavity (not shown) disposed above. The cavity area 230 of the embodiment may include both the first cavity and the second cavity, or may include only one of them.

The cavity region 230 may be disposed between the first reflective layer 220 and the second reflective layer 250. In an embodiment, an active layer may be disposed in the cavity region 230, and the active layer may include a single well structure, a multi well structure, a single quantum well structure, a multi quantum well structure, a quantum dot structure, or the like. It may include any one of the quantum wire structure.

The active layer may be formed using a pair structure of a well layer and a barrier layer, for example, AlGaInP / GaInP, AlGaAs / AlGaAs, AlGaAs / GaAs, GaAs / InGaAs, using a compound semiconductor material of a group III-V element. It doesn't work. The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer.

The first cavity and the second cavity may be formed of Al _y Ga _(1-y) As (0 <y <1) material, but are not limited thereto.

In the first embodiment, the insulating region 242 and the aperture 241 may be disposed on the cavity region 230.

For example, the first emitter E1 includes a first insulating region 242a and a first aperture 241a, and the second emitter E2 includes a second insulating region 242b and a second upper. It may include a location 241b. In addition, the third emitter E3 includes a third insulating region 242c and a third aperture 241c, and the fourth emitter E4 includes a fourth insulating region (not shown) and a fourth aperture. (Not shown).

The insulating region 242 is an insulating layer made of an insulating material, for example, aluminum oxide, and may serve as a current blocking layer. Each of the apertures 241a, 241b, and 241c positioned in the central region of each insulating region may be a non-insulating layer, that is, a conductive layer.

The insulating region 242 may surround the aperture 241. The size of the aperture 241 may be adjusted by the insulating region 242. For example, as the area of the insulating region 242 occupied on the cavity region 230 becomes larger, the area of the aperture 241 may be smaller.

For example, the first aperture 241a may be defined by the first insulating region 242a, and for example, the second aperture 241b may be defined by the second insulating region 242b. have. In addition, the third aperture 241c may be defined by the third insulating region 242c, and the fourth aperture may be defined by the fourth insulating region. In detail, each insulating region 242 may include aluminum gallium arsenide. For example, the insulating region 242 may form an insulating region 242 as AlGaAs reacts with H ₂ O and the edge is changed to aluminum oxide (Al ₂ O ₃ ), and does not react with H ₂ O. In the central region, each aperture made of AlGaAs may be formed.

According to the first embodiment, the laser beam emitted from the cavity region 230 through the apertures 241a, 241b, and 241c may be emitted toward the upper region, compared with the insulating regions 242a, 242b, and 242c. Therefore, the light transmittance of the apertures 241a, 241b, and 241c may be excellent.

<Second reflective layer>

The second reflective layer 250 may be disposed on the cavity region 230.

The second reflective layer 250 may include a gallium-based compound, for example, AlGaAs, and the second reflective layer 250 may be doped with a second conductive dopant. For example, the second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, Ba, or the like. Meanwhile, the first reflective layer 220 may be doped with a p-type dopant, and the second reflective layer 250 may be doped with an n-type dopant.

The second reflective layer 250 may be a distributed Bragg reflector (DBR). For example, the second reflective layer 250 may have a structure in which a first layer (not shown) and a second layer (not shown) made of materials having different refractive indices are alternately stacked at least once.

The first layer and the second layer may include AlGaAs, and in detail, may be formed of a semiconductor material having a compositional formula of Al _x Ga _(1-x) As (0 <x <1). Herein, when Al increases, the refractive index of each layer may decrease, and when Ga increases, the refractive index of each layer may increase. In addition, the thickness of each of the first and second layers may be λ / 4n, λ may be a wavelength of light emitted from the active layer, and n may be a refractive index of each layer with respect to light having the aforementioned wavelength.

The second reflective layer 250 having such a structure may have a reflectance of 99.9% with respect to light in a wavelength region of 940 nm.

The second reflective layer 250 may be formed by alternately stacking the third and fourth layers, and the number of pairs of the first layer and the second layer in the first reflective layer 220 is the second reflective layer 250. ) May be greater than the number of pairs of the third layer and the fourth layer, and as described above, the reflectance of the first reflecting layer 220 may be greater than 99.9% of reflectance of the second reflecting layer 250 by 99.999%. have. For example, the number of pairs of the first layer and the second layer in the first reflective layer 220 may be 20 to 50 times, and the number of pairs of the third layer and the fourth layer in the second reflective layer 250 may be 10 times. To 30 times.

Passivation layer, second electrode

The passivation layer 270 is disposed on the side and top surfaces of the emitters E1, E2, E3, and E4 and the top surface of the first reflective layer 220 exposed between the emitters E1, E2, E3, and E4. Can be. The passivation layer 270 is disposed on the side of each of the emitters E1, E2, E3, and E4 separated in units of segments to protect and insulate the emitters E1, E2, E3, and E4. have. The passivation layer 270 may be made of an insulating material, for example, nitride or oxide.

The second electrode 280 may be disposed to be electrically connected to the second reflective layer 250. That is, the second electrode 280 extends from the pad electrode 290 and contacts a portion of the second reflective layer 250 via the passivation layer 270 surrounding each of the emitters E1, E2, E3, and E4. Can be. The second electrode 280 may be disposed on the passivation layer 270.

The second electrode 280 may be made of a conductive material, for example, may be a metal. For example, the second electrode 280 may include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It can be formed as.

As shown in FIG. 2, the surface light emitting laser device 200 may include a light emitting region 245 in which a laser beam is emitted, and a non-light emitting region 247 in contact with the light emitting region 245 in which the laser beam is not emitted. Can be.

The non-light emitting area 247 is an area where the pad electrode 290 as a bonding pad for electrical connection with the outside is disposed, and no laser beam is generated in the non-light emitting area 247. The light emitting region 245 may include a light emitting structure E, and the light emitting structure E may include a plurality of emitters E1, E2, E3, and E4. A laser beam is generated in each of the plurality of emitters E1, E2, E3, E4, and the generated laser beam can be emitted, for example, toward the upper direction. Accordingly, the emission area 245 may be an area where the laser beams generated by the emitters E1, E2, E3, and E4 are emitted.

While the surface light emitting laser device 200 including the light emitting area 245 and the non-light emitting area 247 has a square shape, the light emitting area 245 of the surface light emitting laser device 200 may have a rectangular shape. However, this is not limitative. The emission region 245 may have a first width W1 in the x-axis direction (hereinafter referred to as a first direction) and a second width W2 in the y-axis direction (hereinafter referred to as a second direction). have. The second width W2 may be larger than the first width W1. Therefore, the emission region 245 may have a rectangular shape longer in the second direction than in the first direction.

Referring back to FIG. 1, the surface light emitting laser package 100 according to the first embodiment may provide the wavelength limiting member 150.

The wavelength limiting member 150 may be disposed on the diffusion part 140. The wavelength limiting member 150 may be disposed on the housing 130. The area (size) of the wavelength limiting member 150 may be larger than the area (size) of the diffusion unit 140. In this case, the wavelength limiting member 150 may be disposed on the housing 130 as well as the diffusion unit 140.

The wavelength limiting member 150 may be in contact with the entire area of the upper surface of the diffusion unit 140 and in contact with the upper surface of the housing 130. The wavelength limiting member 150 may be attached to the diffusion part 140 and the housing 130 by using an adhesive (not shown). The adhesive material may include a silicone resin.

The wavelength limiting member 150 may have a thickness of 0.1 mm to 0.5 mm. The wavelength limiting member 150 may have a thickness of about 0.3 mm, but is not limited thereto. If the wavelength limiting member 150 is less than 0.1 mm, it may be difficult to block the wavelength. When the wavelength limiting member 150 is greater than 0.5 mm, the absorption of light is increased to reduce the amount of light output from the wavelength limiting member 150, thereby lowering the light output efficiency.

The wavelength limiting member 150 may pass at least the wavelength band of the light of the surface light emitting laser device 200. For example, when the surface light emitting laser device 200 emits light in a wavelength band of 940 ± 2 nm, the wavelength limiting member 150 may pass light in a wavelength band larger than a wavelength band of at least 940 ± 2 nm.

As shown in FIG. 6, the wavelength limiting member 150 may emit light having a peak wavelength of 940 nm and a half width (FWHM) of approximately 10 nm. Accordingly, the wavelength limiting member 150 may transmit light having a wavelength band of 940 ± 5 nm and block light having a wavelength band outside the wavelength band of 940 ± 5 nm. For example, when the surface light emitting laser device 200 emits light having a peak wavelength of 948 nm, it is blocked by the wavelength limiting member 150 according to the first embodiment to output any light through the wavelength limiting member 150. Can't be.

The peak wavelength of the light allowed by the wavelength limiting member 150 may be the same as the peak wavelength of the light emitted from the surface light emitting laser device 200. That is, the peak wavelength of the light allowed by the wavelength limiting member 150 and the peak wavelength of the light emitted from the surface light emitting laser device 200 may be 940 nm. The full width at half maximum (FWHM) of the light allowed by the wavelength limiting member 150 may be equal to or larger than the full width at half maximum of the light emitted from the surface light emitting laser device 200. That is, the full width at half maximum (FWHM) of the light allowed by the wavelength limiting member 150 may be 1 to 3 times the full width at half maximum of the light emitted from the surface light emitting laser device 200. When the full width at half maximum (FWHM) of the light allowed by the wavelength limiting member 150 is less than 1 times the full width at half maximum of the light emitted from the surface light emitting laser device 200, the wavelength limiting member 150 is applied to the surface light emitting laser device 200. Blocking part of the wavelength band of the emitted light does not emit the desired color light. When the full width at half maximum (FWHM) of the light allowed by the wavelength limiting member 150 is more than three times the full width at half maximum of the light emitted from the surface light emitting laser device 200, the wavelength limiting member 150 is the surface light emitting laser device 200. A portion of the wavelength band outside the wavelength band of the light emitted from is also passed by the wavelength limiting member 150, thereby degrading the performance of the wavelength limiting member 150.

The wavelength limiting member 150 may be, for example, a filter or a film having a single layer or a multilayer structure. For example, the filter may be an infrared light passing filter that transmits light having a wavelength band of 940 ± 5 nm. For example, the film may be a multilayer thin film having different refractive indices. The multilayer thin film may be made of an insulating material, for example, an organic material or an inorganic material. A thin film film in which inorganic materials having different refractive indices are stacked on each other may be formed, or a thin film film in which organic materials and inorganic materials having different refractive indices are stacked on each other may be formed.

Larger currents may flow in the surface light emitting laser device 200 due to a malfunction or an overoperation of a driving circuit for driving the surface light emitting laser package 100. For example, in the normal operation, a current of, for example, 1000 mA may flow through the surface light emitting laser device 200. In an abnormal operation in which a malfunction or an overaction occurs, a current of, for example, 3000 mA may flow in the surface light emitting laser device 200. As such, when a larger current flows to the surface light emitting laser device 200 due to abnormal operation, heat is generated in the surface light emitting laser device 200, and the heat is emitted from the surface light emitting laser device 200 by the heat. The wavelength band of the light to be shifted can be shifted. This may be due to a change in the band gap energy of the semiconductor material of the surface light emitting laser device 200 by heat.

As shown in FIG. 5, the bandgap energy of InP is 1.35 eV at room temperature (23 ° C., 300 K in absolute temperature), but the band gap energy of InP may be smaller than 1.35 eV as the temperature is increased. Since the wavelength is inversely proportional to the bandgap energy, the inherent wavelength band of the light of the semiconductor device made of InP can be shifted to a larger wavelength band as the temperature is increased.

Other semiconductor materials, such as GaN, Si, Ge may also change in a similar manner to InP. That is, GaN, Si, and Ge may also be shifted to a larger wavelength band of light.

Similarly, the surface light emitting laser device 200 according to the first embodiment may also be shifted to a larger wavelength band inherent in accordance with temperature. The inherent wavelength band of the surface light emitting laser device 200 may be 940 ± 2 nm.

4 shows a state in which the peak wavelength of light is shifted according to the current. Specifically, FIG. 4A shows a state in which the peak wavelength changes according to the current, FIG. 4B shows a state in which the output power changes according to the current, and FIG. 4C shows a state in which the wavelength and light intensity change according to the current.

As shown in FIG. 4A, when, for example, 1000 mA flows to the surface light emitting laser device 200 during normal operation, the surface light emitting laser device 200 may emit light having a wavelength band of approximately 940 ± 2 nm. Can be. When, for example, 3000 mA flows to the surface light emitting laser device 200 during abnormal operation, the surface light emitting laser device 200 may emit light having a wavelength band of approximately 946 ± 4 nm. From this, as the current increases due to abnormal operation, the temperature increases, and as the temperature increases, the bandgap energy decreases, so that the wavelength band of the light of the surface light emitting laser element 200 shifts to a larger wavelength band. Can be.

As shown in FIG. 4B, as the current increases, the output power may also increase. For example, when 1000 mA flows in the surface light emitting laser device 200 in a normal operation, the output power Po output from the surface light emitting laser device 200 may be 1.3W. When 3000 mA flows in the surface light emitting laser device 200 during abnormal operation, the output power Po output from the surface light emitting laser device 200 may be 2.5W.

As shown in FIG. 4C, as the current is increased, not only the wavelength band is shifted but also the light intensity may be increased. The intensity of light has the same meaning as the output power shown in FIG. 4B, which is a normalized output power.

In normal operation, that is, when a current of 1000 mA flows in the surface light emitting laser device 200, the light having a wavelength band of 940 ± 2 nm may be emitted at the light intensity of 0.4 in the surface light emitting laser device 200. In an abnormal operation, that is, when a current of 3000 mA flows in the surface light emitting laser device 200, light having a wavelength band of 946 ± 4 nm may be emitted at the light intensity of 0.5 in the surface light emitting laser device 200. From this, a larger current flows in the surface light emitting laser element 200 during abnormal operation, and heat is generated in the surface light emitting laser element 200 by this current, so that not only the wavelength band of the light shifts but also the intensity of the light. It can also be increased.

As such, when the light shifted to a larger wavelength band and the intensity is increased, the user's eyes may be damaged by the light.

In the above description, the wavelength band of 940 ± 2 nm of the light emitted from the surface light emitting laser element 200 in normal operation is referred to as a unique wavelength band (first wavelength band), and the surface light emitting laser element in abnormal operation. The wavelength band (second wavelength band) of 946 ± 4nm emitted from 200 may be referred to as a shift wavelength band (second wavelength band).

According to the first embodiment, the wavelength limiting member 150 is provided on the surface light emitting laser device 200, thereby blocking the wavelength outside the wavelength band of the light emitted from the surface light emitting laser device 200 by abnormal operation. This can prevent the user's eyes from being damaged.

According to the first embodiment, the wavelength limiting member 150 is attached to the housing 130 as well as the diffuser 140, thereby preventing the diffusion of the diffuser 140 to prevent light from the surface light emitting laser device 200. It can be provided directly to the outside to prevent damaging the user's eyes.

7 is a cross-sectional view showing a surface light emitting laser package according to the second embodiment.

The second embodiment is the same as the first embodiment except that the wavelength limiting member 150 is disposed only in the diffusion unit 140. Thus, features that are not described in the following description can be easily understood from the first embodiment already described above.

Referring to FIG. 7, the surface light emitting laser package 100A according to the second embodiment may include a substrate 110, a surface light emitting laser device 200, a housing 130, a diffusion unit 140, and a wavelength limiting member ( 150). The substrate 110, the surface light emitting laser device 200, the housing 130, the diffuser 140, and the wavelength limiting member 150 may be configured as a modular module. The surface light emitting laser package 100A according to the second embodiment may further include a circuit board 160 on which one or more modules are mounted, but is not limited thereto.

The area (size) of the wavelength limiting member 150 may be the same as the area (size) of the diffusion unit 140. The wavelength limiting member 150 may be disposed on the upper surface of the diffusion unit 140. The wavelength limiting member 150 may be in contact with the top surface of the diffusion unit 140. That is, the wavelength limiting member 150 may be attached to the upper surface of the diffusion part 140 using an adhesive. The adhesive material may include a silicone resin.

The upper surface of the wavelength limiting member 150 may be horizontally aligned with the upper surface of the housing 130. Since the upper surface of the wavelength limiting member 150 does not protrude above the housing 130, detachment of the wavelength limiting member 150 due to friction with the surroundings may be prevented. Accordingly, the depth of the recess of the housing 130 may be equal to the sum of the thickness of the diffusion portion 140 and the thickness of the wavelength limiting member 150.

8 is a sectional view showing a surface light emitting laser package according to the third embodiment.

The third embodiment is the same as the first embodiment except that the wavelength limiting member 150 is disposed only in the diffusion unit 140. In addition, the third embodiment is the same as the second embodiment except for the arrangement position of the diffusion unit 140. Thus, features not described in the following description can be easily understood from the first and second embodiments already described above.

Referring to FIG. 8, the surface light emitting laser package 100B according to the third embodiment may include a substrate 110, a surface light emitting laser device 200, a housing 130, a diffusion part 140, and a wavelength limiting member ( 150). The substrate 110, the surface light emitting laser device 200, the housing 130, the diffuser 140, and the wavelength limiting member 150 may be configured as a modular module. The surface light emitting laser package 100B according to the third embodiment may further include a circuit board 160 on which one or a plurality of modules are mounted, but is not limited thereto.

The wavelength limiting member 150 may be disposed on the bottom surface of the diffusion part 140. The wavelength limiting member 150 may be in contact with the bottom surface of the diffusion unit 140. That is, the wavelength limiting member 150 may be attached to the bottom surface of the diffusion part 140 using an adhesive. The adhesive material may include a silicone resin.

The area (size) of the wavelength limiting member 150 may be smaller than the area (size) of the diffusion unit 140. That is, the area (size) of the wavelength limiting member 150 may be equal to or smaller than the area (size) of the opening formed inside the housing 130. In this case, the wavelength limiting member 150 is not disposed in the recess area of the housing 130.

As another example, although not shown, the area (size) of the wavelength limiting member 150 may be the same as the area (size) of the diffusion unit 140. In this case, a peripheral region of the wavelength limiting member 150 disposed below the diffusion unit 140 may be disposed in the recess region of the housing 130.

On the other hand, the upper surface of the diffusion portion 140 may be horizontally matched with the upper surface of the housing 130. Since the upper surface of the diffusion unit 140 does not protrude above the housing 130, detachment of the diffusion unit 140 due to friction with the surroundings may be prevented.

9 is a sectional view showing a surface light emitting laser package according to the fourth embodiment.

The fourth embodiment is the same as the first embodiment except that the wavelength limiting member 150 is disposed only in the diffusion unit 140. In addition, the fourth embodiment is the same as the second embodiment except for the arrangement position of the diffusion unit 140. In addition, the fourth embodiment is the same as the third embodiment except that the diffusion unit 140 is disposed under the pattern 145 provided in the diffusion unit 140. Accordingly, features not described in the following description can be easily understood from the first to third embodiments already described above.

Referring to FIG. 9, the surface light emitting laser package 100C according to the fourth embodiment may include a substrate 110, a surface light emitting laser device 200, a housing 130, a diffusion unit 140, and a wavelength limiting member ( 150). The substrate 110, the surface light emitting laser device 200, the housing 130, the diffuser 140, and the wavelength limiting member 150 may be configured as a modular module. The surface light emitting laser package 100C according to the fourth embodiment may further include a circuit board 160 on which one or a plurality of modules are mounted, but is not limited thereto.

The diffuser 140 may include a body 141 and a plurality of patterns 145. The pattern 145 may be disposed under the body 141.

The body 141 may be made of a material having excellent durability and strength, such as glass. The pattern 145 may be made of a material that is easy to process, such as a polymer resin.

As another example, the pattern 145 and the body 141 may be made of the same material, glass, or polymer resin. For example, the surface of the base substrate 141 of the polymer resin may be surface treated to form a pattern 145 on the surface of the base substrate 141.

The pattern 145 may be disposed on the bottom surface of the body 141 of the diffusion parts 140 and 140 to face the surface light emitting laser device 200.

For example, the pattern 145 may include a micro lens, an uneven pattern, or the like. The size of the pattern 145 may be uniform, but is not limited thereto.

The size of each pattern 145 may be the same. Alternatively, each pattern 145 may have a different random shape.

The thickness (or height) of each pattern 145 may be the same. Alternatively, the thickness (or height) of each pattern 145 may be different from each other. The pattern 145 may have a protruding region protruding from the body 141 in a lower direction, for example. The lowest point of the protruding region may be the same or different for each pattern 145. The lowest point of the protruding region may have a vertex, but is not limited thereto. The surface of each pattern 145 may have a round shape, a straight shape, or the like. Each pattern 145 may have a bumpy shape. Some patterns may be disposed to be in contact with each other and other patterns may be disposed to be spaced apart from each other.

The wavelength limiting member 150 may be disposed on the bottom surface of the diffusion part 140, specifically, on the bottom surface of the plurality of patterns 145. The wavelength limiting member 150 may be in contact with the bottom surface of the pattern 145 of the diffusion part 140. That is, the wavelength limiting member 150 may be attached to the bottom surface of the pattern 145 of the diffusion part 140 using an adhesive. The adhesive material may include a silicone resin.

In the above description, the light emitted from the surface light emitting laser device 200 is limited to have a wavelength range of 940 ± 2 nm. However, the embodiment is not limited thereto, and light of any wavelength band including ultraviolet light and visible light is not limited thereto. The same can be applied to the emitting surface light emitting laser device. For example, when the wavelength band of the light emitted from the surface light emitting laser element is 200 ± 2 nm and is the ultraviolet wavelength band, for example, a wavelength limiting member that passes only this ultraviolet wavelength band and blocks other wavelengths may be adopted.

On the other hand, the surface light emitting laser package (100, 100A, 100B, 100C) according to the embodiment described above may be applied to a proximity sensor, an auto focus device, and the like. For example, the autofocus apparatus according to the embodiment may include a light emitting unit for emitting light and a light receiving unit for receiving light. As an example of the light emitting unit, at least one of the surface light emitting laser packages 100, 100A, 100B, and 100C according to the embodiment described with reference to FIG. 1 may be applied. As an example of the light receiving portion, a photodiode may be applied. The light receiver may receive light reflected from an object from the light emitted from the light emitter.

The auto focus device may be variously applied to a mobile terminal, a camera, a vehicle sensor, and an optical communication device. The auto focus device may be applied to various fields for multi-position detection for detecting the position of the subject.

10 is a perspective view of a mobile terminal to which an autofocusing apparatus including a surface light emitting laser package according to an embodiment is applied.

As shown in FIG. 10, the mobile terminal 1500 of the embodiment may include a camera module 1520, a flash module 1530, and an auto focusing device 1510 provided at a rear surface thereof. Here, the auto focusing device 1510 may include one of the surface light emitting laser packages 100, 100A, 100B, and 100C according to the embodiment described with reference to FIG. 1 as a light emitting unit.

The flash module 1530 may include a light emitting device that emits light therein. The flash module 1530 may be operated by camera operation of a mobile terminal or control of a user. The camera module 1520 may include an image capturing function and an auto focus function. For example, the camera module 1520 may include an auto focus function using an image.

The auto focus device 1510 may include an auto focus function using a laser. The auto focus device 1510 may be mainly used in a condition in which the auto focus function using the image of the camera module 1520 is degraded, for example, in a proximity or dark environment of 10 m or less. The autofocus device 1510 may include a light emitting unit including a surface light emitting laser device, and a light receiving unit converting light energy such as a photodiode into electrical energy.

The above detailed description should not be construed as limiting in all respects but should be considered as illustrative. The scope of the embodiments should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the embodiments are included in the scope of the embodiments.

100: surface light emitting laser package
110: substrate
130: housing
140: diffusion part
141: body
145: pattern
150: wavelength limiting member
160: circuit board
181, 182: electrode
183, 184: bonding part
185, 186: connection wiring
191: wire
200: surface light emitting laser device
210: substrate
215, 280: electrode
220, 250: reflective layer
230: cavity area
241a, 241b, 241c: aperture
242: insulation area
245: light emitting area
247: non-emitting area
270: passivation layer
290: pad electrode
E: light emitting structure
E1, E2, E3: Emitter
W1, W2: Width

Claims (10)

Board;
A surface light emitting laser element disposed on the substrate;
A housing disposed around the surface light emitting laser element;
A diffusion unit disposed on the surface light emitting laser element; And
A wavelength limiting member disposed on said surface light emitting laser element,
The surface light emitting laser device emits light having a first wavelength band,
The wavelength limiting member,
And a surface light emitting laser package for blocking a wavelength outside the first wavelength band of the light. The method of claim 1,
The wavelength limiting member,
And a surface light emitting laser package transmitting only a second wavelength band larger than the first wavelength band. The method of claim 2,
The peak wavelength of the second wavelength band is the same as the peak wavelength of the first wavelength band,
And a half width of the second wavelength band is greater than a half width of the first wavelength band. The method of claim 3,
The full width at half maximum of the second wavelength band is one to three times the full width at half maximum of the first wavelength band. The method of claim 3,
The peak wavelength of the first wavelength band and the peak wavelength of the second wavelength band is 940nm surface light emitting laser package. The method of claim 3,
The full width at half maximum of the first wavelength band is 2 nm,
The half value width of the second wavelength band is 5nm surface-emitting laser package. The method of claim 1,
The wavelength limiting member,
Surface light emitting laser package disposed on the diffusion. The method of claim 1,
The wavelength limiting member,
Surface light emitting laser package disposed on the diffusion and the housing. The method of claim 1,
The wavelength limiting member,
And a surface light emitting laser package disposed between the surface light emitting laser element and the diffusion part. The surface light emitting laser package according to any one of claims 1 to 9; And
And a light receiving part receiving the reflected light of the light emitted from the surface light emitting laser package.

Images