KR102660071B1 - Vertical-cavity surface-emitting laser package and automatic focusing device - Google Patents

Abstract

The surface light-emitting laser package includes a surface light-emitting laser element disposed on a substrate, a housing disposed around the surface light-emitting laser element, a diffusion portion disposed on the surface light-emitting laser element, and a surface light-emitting laser element. It includes a wavelength limiting member disposed in.
The surface light emitting laser device may emit light having a first wavelength band. The wavelength limiting member may block wavelengths outside the first wavelength band of light.

Description

Vertical-cavity surface-emitting laser package and automatic focusing device}

The embodiment relates to a surface light emitting laser package and an autofocus device.

Semiconductor devices containing compounds such as GaN and AlGaN have many advantages, such as having a wide and easily adjustable band gap energy, and can be used in a variety of ways, such as light emitting devices, light receiving devices, and various diodes.

In particular, surface light emitting laser packages using semiconductor group 3-5 or group 2-6 compound semiconductor materials can be used in optical communication, sensors, autofocus devices, proximity sensors, and autofocus devices.

When heat is generated due to over-operation or malfunction of the driving circuit that drives the surface light-emitting laser package, the wavelength band of light of the surface light-emitting laser element of the surface light-emitting laser package may be shifted to a longer wavelength range. This long wavelength range can cause damage to the user's eyes, so a solution to this problem is needed.

The embodiments aim to solve the above-described problems and other problems.

Another object of the embodiment is to provide a surface light emitting laser package and an autofocus device having a new structure.

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

According to one aspect of the embodiment to achieve the above or other objects, a surface light emitting laser package includes: a substrate; A surface light emitting laser device disposed on the substrate; a housing disposed around the surface light emitting laser element; a diffusion portion disposed on the surface light-emitting laser device; 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 wavelengths of light outside the first wavelength band.

According to another aspect of the embodiment, an autofocus device includes the surface light emitting laser package; And it may include a light receiving unit that receives reflected light from the surface light emitting laser package.

The effects of the surface light emitting laser package and autofocus device according to the embodiment will be described as follows.

According to at least one of the embodiments, a wavelength limiting member is provided on the expansion unit and the housing to block light having a second wavelength band emitted from the surface light emission laser element due to abnormal operation, thereby preventing damage to the user's eyes. There is an advantage in being able to avoid this.

According to at least one of the embodiments, the wavelength limiting member is attached to the housing as well as the diffusion unit, thereby preventing the diffusion unit from leaving and preventing the light from the surface light-emitting laser device from being provided directly to the outside and damaging the user's eyes. There is an advantage in that it can be done.

Additional scope of applicability of the embodiments will become apparent from the detailed description that follows. However, since various changes and modifications within the spirit and scope of the embodiments may be clearly understood by those skilled in the art, the detailed description and specific embodiments, such as preferred embodiments, should be understood as being given by way of example only.

1 is a cross-sectional view showing a surface light-emitting laser package according to a first embodiment.
Figure 2 is a plan view of a surface light emitting laser device according to the first embodiment.
FIG. 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.
Figure 4 shows how the peak wavelength of light shifts depending on the current.
Figure 5 shows the change in bandgap energy according to temperature.
Figure 6 shows the peak wavelength according to the wavelength of the wavelength limiting member.
Figure 7 is a cross-sectional view showing a surface light emitting laser package according to a second embodiment.
Figure 8 is a cross-sectional view showing a surface light-emitting laser package according to a third embodiment.
Figure 9 is a cross-sectional view showing a surface light emitting laser package according to a fourth embodiment.
Figure 10 is a perspective view of a mobile terminal to which an autofocus device including a surface light-emitting laser package according to an embodiment is applied.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves. Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the embodiments, It should be understood to include equivalents or substitutes.

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

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

The substrate 110 can support all components placed on the substrate 110 . For example, the substrate 110 may support the surface light emitting laser element 200, housing 130, diffusion unit 140, and wavelength limiting member 150 disposed thereon. The surface light emitting laser device 200, housing 130, diffusion unit 140, wavelength limiting member 150, and 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 with high thermal conductivity. The substrate 110 may be made of a material with good heat dissipation properties so that heat generated by the surface light emitting laser device 200 can be efficiently dissipated 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 co-fired low temperature co-fired ceramic (LTCC) or high temperature co-fired ceramic (HTCC).

Additionally, 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 (Al2O3).

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

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

The surface light-emitting laser package 100 according to the first embodiment can provide a 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. For example, the surface light emitting laser device 200 may emit a laser beam having an angle of view of 15° to 25° upward. The surface light emitting laser device 200 may include a plurality of emitters (E1, E2, E3, and E4 in FIG. 2) that emit circular beams. An example of the surface light emitting laser device 200 will be described again 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 disposed on the substrate 110 to be spaced apart from each other.

One 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 a wire 191. The surface light emitting laser device 200 may be electrically connected to the second electrode 182 through 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 position of the wires connecting the surface light-emitting laser device 200 and the second electrode 182 are determined by 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. It can be selected by etc.

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 below the substrate 110 . For example, first and second recesses spaced apart from each other are formed on the lower surface of the substrate 110, the first bonding portion 183 is disposed in the first recess, and the second bonding portion 185 is disposed in the second recess. ) can be placed

For example, the lower surface of the first bonding part 183 and the lower surface of the second bonding part 184 may each be electrically connected by surface contact with a signal line (not shown) of the circuit board 160. 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 arranged to be spaced apart from each other under the substrate 110 . The first bonding part 183 and the second bonding part 184 may have circular pads, but this is not limited.

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

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

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

According to the first embodiment, driving power can 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 element 200 is connected to the first electrode 181 by die bonding and to the second electrode 182 by wire bonding. It was explained based on the case where it is connected in this way.

However, the method by which driving power is supplied to the surface light-emitting laser device 200 may be modified and applied in various ways. 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. Additionally, 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. Housing 130 may be disposed on 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 area (center area) and a second area (peripheral area) surrounding the first area. 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 a second region of the substrate 120. The second electrode 182 may be positioned between the first electrode 181 on the substrate 110 and the housing 130. The housing 130 may be disposed around the surface light emitting laser device 200. The outer surface of the housing 130 may be aligned 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. Housing 130 may include a material with high thermal conductivity. The housing 130 may be made of a material with good heat dissipation properties so that heat generated by the surface light emitting laser device 200 can be efficiently dissipated to the outside. Housing 130 may include an insulating material.

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

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 (Al2O3).

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

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

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

Additionally, the housing 130 may be formed of a different material from the substrate 110. Substrate 110 may also 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 also 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 with excellent heat dissipation characteristics. Accordingly, heat generated from the surface light emitting laser device 200 can be effectively emitted to the outside.

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

By way of example, the adhesive layer may include an organic material. The adhesive layer may include an epoxy-based resin. Additionally, the adhesive layer may include silicone-based resin.

Meanwhile, a step may be provided in the upper area of the housing 130 in contact with the inside. For example, a recess area 142 may be provided in the upper area of the housing 130. By way of example, the width and/or depth of recessed region 142 may be provided in the hundreds of micrometers.

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

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

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

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

The diffusion portion 140 may include an anti-reflective function. For example, the diffusion unit 140 may include an anti-reflection layer disposed on one surface opposite to the surface light emitting laser device 200. The anti-reflection layer may be formed separately from the diffusion portion 140. The diffusion portion 140 may include an anti-reflective layer disposed on a lower surface facing the surface light emitting laser device 200. The anti-reflection layer prevents the laser beam incident from the surface light-emitting laser device 200 from being reflected on the surface of the diffusion unit 140 and allows it to transmit into the diffusion unit 140, thereby improving light loss due to reflection.

For example, the anti-reflection layer may be formed of an anti-reflection coating film and attached to the surface of the diffusion unit 140. The anti-reflective layer may be formed on the surface of the diffusion portion 140 through spin coating or spray coating. As an example, the anti-reflective layer may be formed as a single layer or multiple layers containing at least one of the group including TiO2, SiO2, Al2O3, Ta2O3, ZrO2, and MgF2.

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 portion 183 disposed at the lower portion of the substrate 100 is electrically connected to the first signal line of the circuit board 160, and is disposed at the lower portion of the substrate to form the first bonding portion 183 and the first bonding portion 183. The second bonding portion 184 spaced apart in the horizontal direction may be electrically connected to the second signal line of the circuit board 160.

Meanwhile, as described above, the substrate 110 and the housing 130 may be manufactured through a wafer level package process. According to the first embodiment, the diffusion portion 140 may also be attached to the housing 130 through a wafer level package process.

That is, the surface light-emitting laser element 200 and the housing 130 are attached to the substrate 110 at the wafer level, and the diffusion part 140 is attached to the housing 130, and then cut using a cutting method such as dicing. A plurality of surface light-emitting laser packages may be provided in which a surface light-emitting laser device 200, a housing 130, and a diffusion unit 140 are combined with the substrate 110.

As such, when the surface light emitting laser package 100 including the substrate 110, the housing 130, and the diffusion portion 140 is manufactured by a wafer level package process, the outer surface of the substrate 110 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, since there is no step between the outer surface of the substrate 110 and the outer surface of the housing 130, damage occurs due to moisture permeation and external friction due to the step structure in the conventional surface light-emitting laser package. can be fundamentally prevented.

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

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

Below, the surface light emitting laser device 200 will be described in detail. FIG. 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 line II' of the surface light-emitting laser device according to the first embodiment shown in FIG. 2.

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

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

The light emitting structure (E) may include a plurality of emitters (E1, E2, E3, E4). Each emitter (E1, E2, E3, E4) may be arranged to be spaced apart from each other. The light emitting structure (E) may include a second electrode 280. The light emitting area 245 may include a first area and a second area. A plurality of first areas may be defined, and an area between these first areas may be defined as a second area. In this case, each emitter E1, E2, E3, and E4 may be placed in the first area, and the second electrode 280 may be placed in the second area. Each emitter E1, E2, E3, and E4 may be surrounded by a second electrode 280. The second electrode 280 may be formed integrally with the pad electrode 290, but this is not limited. The second electrode 280 may extend from the pad electrode 290 to the light-emitting area 245 and be disposed in the light-emitting area 245 . As will be explained later, the second electrode 280 can electrically connect a 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 includes 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 area 230 may include an active layer (not shown) and a cavity (not shown), which will be described in detail below. The insulating area 242 includes a first insulating area 242a disposed in the first emitter E1, a second insulating area 242b disposed in the second emitter E2, and a third emitter E3. It may include, but is not limited to, a third insulating area 242c disposed in .

<Substrate, first electrode>

In the first embodiment, the substrate 210 may be a conductive substrate or a non-conductive substrate. When using a conductive substrate, a metal with excellent electrical conductivity can be used, and the heat generated when the surface light-emitting laser device 200 operates must be sufficiently dissipated, so a GaAs substrate or metal substrate with high thermal conductivity, or silicon ( Si) substrate, etc. can be used.

When using a non-conductive substrate, an AlN substrate, sapphire (Al ₂ O ₃ ) substrate, or ceramic-based substrate can be used.

In an embodiment, the first electrode 215 may be disposed under the substrate 210, and the first electrode 215 may be made of a conductive material in a single layer or multiple layers. For example, the first electrode 215 may be a metal and includes at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). By forming a single-layer or multi-layer structure, the electrical properties can be improved and the light output can be increased.

<First reflective layer>

A 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, etc.

Additionally, 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 first and second layers 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 made of a semiconductor material with a composition formula of Al _x Ga _(1-x) As (0<x<1). Here, as Al in the first or second layer increases, the refractive index of each layer may decrease, and as 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 the wavelength of light generated in the cavity region 230, and n may be the refractive index of each layer with respect to light of the above-mentioned wavelength. Here, λ may be 650 to 980 nm, and n may be the refractive index of each layer. The first reflective layer 220 of this structure may have a reflectance of 99.999% for light in a wavelength range of about 940 nm.

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

<Cavity area, insulation area, aperture>

In the first embodiment, a cavity area 230, an insulating area 242, and an aperture 241 may be disposed on the first reflective layer 220. Specifically, the cavity area 230 may be placed on the first reflective layer 220, and the insulating area 242 and the aperture 241 may be placed on the cavity area 230.

The cavity area 230 may include an active layer (not shown), a first cavity (not shown) disposed below 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 the two.

The cavity area 230 may be disposed between the first reflective layer 220 and the second reflective layer 250. An active layer may be disposed in the cavity region 230 of the embodiment, and the active layer may have a single well structure (Double Hetero Structure), a multi-well structure, a single quantum well structure, a multi-quantum well (MQW) structure, a quantum dot structure, or It may include any one of quantum wire structures.

The active layer may be formed in a pair structure of a well layer and a barrier layer, for example, AlGaInP/GaInP, AlGaAs/AlGaAs, AlGaAs/GaAs, and GaAs/InGaAs, using a compound semiconductor material of group III-V elements, but is limited to this. It doesn't work. The well layer may be formed of a material having an energy band gap smaller than that 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, an insulating area 242 and an aperture 241 may be disposed on the cavity area 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 wife (241b). In addition, the third emitter E3 includes a third insulating area 242c and a third aperture 241c, and the fourth emitter E4 includes a fourth insulating area (not shown) and a fourth aperture. (not shown) may be included.

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

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

For example, the first aperture 241a may be defined by the first insulating area 242a, and for example, the second aperture 241b may be defined by the second insulating area 242b. there is. Additionally, the third aperture 241c may be defined by the third insulating area 242c, and the fourth aperture may be defined by the fourth insulating area. Specifically, each insulating region 242 may include aluminum gallium arsenide. For example, the insulating region 242 may be formed as AlGaAs reacts with H ₂ O and its edges change to aluminum oxide (Al ₂ O ₃ ), and the insulating region 242 may be formed as AlGaAs reacts with H ₂ O and its edges change into aluminum oxide (Al 2 O 3 ). In the central region, each aperture made of AlGaAs may be formed.

According to the first embodiment, the laser beam emitted from the cavity area 230 may be emitted toward the upper area through each aperture 241a, 241b, and 241c, and compared to the insulating areas 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 area 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 conductivity type dopant. For example, the second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, Ba, etc. 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 first layers (not shown) and second layers (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 made of a semiconductor material with a composition formula of Al _x Ga _(1-x) As (0<x<1). Here, as Al increases, the refractive index of each layer decreases, and as Ga increases, the refractive index of each layer increases. In addition, the thickness of each of the first layer and the second layer is λ/4n, λ may be the wavelength of light emitted from the active layer, and n may be the refractive index of each layer for light of the above-mentioned wavelength.

The second reflective layer 250 of this structure may have a reflectance of 99.9% for light in the wavelength range of 940 nm.

The second reflective layer 250 may be formed by alternately stacking 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 more than the number of pairs of the third and fourth layers, and in this case, as described above, the reflectance of the first reflective layer 220 may be approximately 99.999%, which may be greater than the reflectance of the second reflective layer 250, which is 99.9%. there is. 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, and the number of pairs of the third layer and the fourth layer in the second reflective layer 250 may be 10. It may be from 30 to 30 times.

<Passivation layer, second electrode>

A passivation layer 270 is disposed on the side and top surfaces of the emitters (E1, E2, E3, E4) and on the top surface of the first reflective layer 220 exposed between each emitter (E1, E2, E3, E4). It can be. The passivation layer 270 is disposed on the side of each emitter (E1, E2, E3, E4) separated in segments to protect and insulate each emitter (E1, E2, E3, E4). there is. 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 emitter (E1, E2, E3, and E4). It 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, metal. For example, the second electrode 280 has a single-layer or multi-layer structure including 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 area 245 from which a laser beam is emitted and a non-emission area 247 that does not emit a laser beam and is in contact with the light-emitting area 245. You can.

The non-emission area 247 is an area where a pad electrode 290 as a bonding pad for electrical connection to the outside is disposed, and no laser beam is generated in this non-emission area 247. The light emitting area 245 includes 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 from each of the plurality of emitters E1, E2, E3, and E4, and the generated laser beam may be emitted, for example, toward the top. Accordingly, the light-emitting area 245 may be an area where laser beams generated by the plurality of 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, there is no limitation to this. The light emitting area 245 may have a first width W1 in the x-axis direction (hereinafter referred to as the first direction) and a second width W2 in the y-axis direction (hereinafter referred to as the second direction). there is. The second width W2 may be larger than the first width W1. Accordingly, the light emitting area 245 may have a rectangular shape that is longer in the second direction than in the first direction.

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

The wavelength limiting member 150 may be disposed on the diffusion portion 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 portion 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 contact the entire upper surface of the diffusion unit 140 and may contact the upper surface of the housing 130. The wavelength limiting member 150 may be attached to the diffusion portion 140 and the housing 130 using an adhesive (not shown). The adhesive may include silicone-based 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 approximately 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 larger than 0.5 mm, absorption of light increases and the amount of light output from the wavelength limiting member 150 decreases, which may reduce light output efficiency.

The wavelength limiting member 150 can pass at least the wavelength band of 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 can at least pass light in a wavelength band larger than the wavelength band of 940 ± 2 nm.

As shown in FIG. 6, the wavelength limiting member 150 can emit light with a peak wavelength of 940 nm and a full width at half maximum (FWHM) of approximately 10 nm. Therefore, the wavelength limiting member 150 can transmit light having a wavelength band of, for example, 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 with a peak wavelength of 948 nm, it is blocked by the wavelength limiting member 150 according to the first embodiment, so that no light is output through the wavelength limiting member 150. It can't be.

The peak wavelength of light allowed by the wavelength limiting member 150 may be the same as the peak wavelength of light emitted from the surface light emitting laser device 200. That is, the peak wavelength of light allowed by the wavelength limiting member 150 and the peak wavelength of light emitted from the surface light emitting laser device 200 may be 940 nm. The full width at half maximum (FWHM) of light allowed by the wavelength limiting member 150 may be equal to or greater 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 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 light allowed by the wavelength limiting member 150 is less than 1 time the half maximum width of the light emitted from the surface light emitting laser device 200, the wavelength limiting member 150 is Part of the wavelength band of the emitted light is blocked, preventing the desired color light from being emitted. When the full width at half maximum (FWHM) of light allowed by the wavelength limiting member 150 is more than 3 times the half width of the light emitted from the surface light emitting laser device 200, the wavelength limiting member 150 is connected to the surface light emitting laser device 200. Some wavelength bands outside the wavelength band of the light emitted from may also be passed by the wavelength limiting member 150, thereby deteriorating the performance of the wavelength limiting member 150.

The wavelength limiting member 150 may be, for example, a filter or film having a single-layer or multi-layer structure. For example, the filter may be an infrared pass filter that transmits light with a wavelength band of 940 ± 5 nm. For example, the film may be a multilayer thin film having different refractive indices. This multilayer thin film may be made of an insulating material, such as an organic material or an inorganic material. A thin film may be formed by stacking inorganic materials with different refractive indices, or a thin film can be formed by stacking organic and inorganic materials with different refractive indices.

A larger current may flow to the surface light emitting laser device 200 due to malfunction or overoperation of the driving circuit that drives the surface light emitting laser package 100. For example, in normal operation, a current of, for example, 1000 mA may flow through the surface light-emitting laser device 200. In abnormal operation where malfunction or overoperation occurs, a current of, for example, 3000 mA may flow through the surface light-emitting laser device 200. In this way, when a larger current flows through the surface light-emitting laser device 200 due to abnormal operation, heat is generated in the surface light-emitting laser device 200, and this heat is emitted from the surface light-emitting laser device 200. The wavelength band of light may be shifted. This may be due to changes in the bandgap energy of the semiconductor material of the surface light emitting laser device 200 due to heat.

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

Other semiconductor materials, such as GaN, Si, and Ge, can also be transformed into modes similar to InP. That is, for GaN, Si, and Ge, the unique wavelength band of light can be shifted to a larger wavelength band.

Likewise, the surface light emitting laser device 200 according to the first embodiment may also have its own wavelength band shifted to a larger wavelength band depending on temperature. The unique wavelength band of the surface light emitting laser device 200 may be 940 ± 2 nm.

Figure 4 shows how the peak wavelength of light shifts depending on the current. Specifically, Figure 4a shows the peak wavelength changing according to the current, Figure 4b shows the output power changing according to the current, and Figure 4c shows the wavelength and light intensity changing according to the current.

As shown in FIG. 4A, when, for example, 1000 mA flows through the surface light-emitting laser device 200 during normal operation, the surface light-emitting laser device 200 emits light having a wavelength band of approximately 940 ± 2 nm. You can. When, for example, 3000 mA flows through 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 band gap energy decreases, so the wavelength band of the light of the surface light emitting laser device 200 will shift to a larger wavelength band. You can.

As shown in Figure 4b, as the current increases, the output power can also increase. For example, when 1000 mA flows through the surface light-emitting laser device 200 during normal operation, the output power (Po) output from the surface light-emitting laser device 200 may be 1.3W. When 3000 mA flows through 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 increases, not only does the wavelength band shift, but the intensity of light may also increase. The intensity of light has the same meaning as the output power shown in FIG. 4B and is a quantified (normalized) output power.

During normal operation, that is, when a current of 1000 mA flows through the surface light-emitting laser device 200, light having a wavelength band of 940 ± 2 nm may be emitted from the surface light-emitting laser device 200 with a light intensity of 0.4. During abnormal operation, that is, when a current of 3000 mA flows through the surface light-emitting laser device 200, light having a wavelength band of 946 ± 4 nm may be emitted from the surface light-emitting laser device 200 with a light intensity of 0.5. From this, during abnormal operation, a larger current flows through the surface light-emitting laser device 200, and this current radiates heat to the surface light-emitting laser device 200, which not only shifts the wavelength band of the light but also shifts the intensity of the light. It can also be increased.

If light that is shifted to a larger wavelength band and has increased intensity is left unattended, the user's eyes may be damaged by this light.

In the above description, the wavelength band of 940 ± 2 nm of light emitted from the surface light-emitting laser device 200 during normal operation is referred to as the unique wavelength band (first wavelength band), and during abnormal operation, the surface light-emitting laser device 200 The wavelength band (second wavelength band) of 946 ± 4 nm emitted at (200) may be referred to as the 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 to block wavelengths outside the wavelength band of light emitted from the surface light-emitting laser device 200 due to abnormal operation. This can prevent damage to the user's eyes.

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

Figure 7 is a cross-sectional view showing a surface light emitting laser package according to a 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 portion 140. Accordingly, features 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 includes a substrate 110, a surface light-emitting laser element 200, a housing 130, a diffusion portion 140, and a wavelength limiting member ( 150) may be included. The substrate 110, surface light emitting laser device 200, housing 130, diffusion unit 140, and 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 portion 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 upper surface of the diffusion unit 140. That is, the wavelength limiting member 150 may be attached to the upper surface of the diffusion unit 140 using an adhesive. The adhesive may include silicone-based 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 surroundings can 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.

Figure 8 is a cross-sectional view showing a surface light-emitting laser package according to a 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 portion 140. Additionally, the third embodiment is the same as the second embodiment except for the arrangement position of the diffusion unit 140. Accordingly, 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 includes a substrate 110, a surface light-emitting laser element 200, a housing 130, a diffusion portion 140, and a wavelength limiting member ( 150) may be included. The substrate 110, surface light emitting laser device 200, housing 130, diffusion unit 140, and 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 more modules are mounted, but is not limited thereto.

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

The area (size) of the wavelength limiting member 150 may be smaller than the area (size) of the diffusion portion 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 portion 140. In this case, the peripheral area of the wavelength limiting member 150 disposed below the diffusion portion 140 may be disposed in the recess area of the housing 130.

Meanwhile, the top surface of the diffusion unit 140 may be horizontally aligned with the top surface of the housing 130. Since the upper surface of the diffusion unit 140 does not protrude above the housing 130, attachment and detachment of the diffusion unit 140 due to friction with surroundings can be prevented.

Figure 9 is a cross-sectional view showing a surface light emitting laser package according to a 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 portion 140. Additionally, 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 part 140 is disposed below the pattern 145 provided in the diffusion part 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 includes a substrate 110, a surface light-emitting laser element 200, a housing 130, a diffusion portion 140, and a wavelength limiting member ( 150) may be included. The substrate 110, surface light emitting laser device 200, housing 130, diffusion unit 140, and 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 more modules are mounted, but is not limited thereto.

The diffusion portion 140 may include a body 141 and a plurality of patterns 145. The pattern 145 may be disposed on the lower part of the body 141.

The body 141 may be made of a material with excellent durability and strength, for example, glass. The pattern 145 may be made of a material that is easy to process, such as 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 polymer resin base substrate 141 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 lower surface of the body 141 of the diffusion portion 140 (140) to face the surface light emitting laser device 200.

For example, the pattern 145 may include a micro lens, a concave-convex pattern, etc. 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 different random shapes.

The thickness (or height) of each pattern 145 may be the same. Alternatively, the thickness (or height) of each pattern 145 may be different. The pattern 145 may have a protruding area that protrudes from the body 141, for example, in a downward direction. The lowest point of this protruding area may be the same or different for each pattern 145. The lowest point of the protruding area may have a vertex, but this is not limited. The surface of each pattern 145 may have a round shape, a straight shape, etc. Each pattern 145 may have a bumpy shape. Some patterns may be placed in contact with each other, and other patterns may be placed spaced apart from each other.

The wavelength limiting member 150 may be disposed on the lower surface of the diffusion unit 140, specifically, on the lower surface of the plurality of patterns 145. The wavelength limiting member 150 may be in contact with the lower surface of the pattern 145 of the diffusion portion 140. That is, the wavelength limiting member 150 may be attached to the lower surface of the pattern 145 of the diffusion portion 140 using an adhesive. The adhesive may include silicone-based resin.

In the above description, the light emitted from the surface light emitting laser device 200 is limited to having a wavelength band of 940 ± 2 nm, but the embodiment is not limited to this and includes light of any wavelength band including ultraviolet rays and visible light. The same can be applied to a surface light emitting laser device that emits light. For example, if the wavelength band of light emitted from the surface light emitting laser device is 200 ± 2 nm, which 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.

Meanwhile, the surface light emitting laser package (100, 100A, 100B, 100C) according to the embodiment described above can be applied to a proximity sensor, an autofocus device, etc. For example, an autofocus device according to an embodiment may include a light emitting unit that emits light and a light receiving unit that receives 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. A photodiode may be applied as an example of a light receiving unit. The light receiving unit can receive light emitted from the light emitting unit and reflected from an object.

Autofocus devices can be applied to a variety of devices such as mobile terminals, cameras, vehicle sensors, and optical communication devices. Autofocus devices can be applied to various fields for multi-position detection, which detects the position of a subject.

Figure 10 is a perspective view of a mobile terminal to which an autofocus device 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 autofocus device 1510 provided at the rear. Here, the autofocus 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 inside that emits light. The flash module 1530 can be operated by operating a camera of a mobile terminal or by user control. The camera module 1520 may include an image capture function and an autofocus function. For example, the camera module 1520 may include an autofocus function using an image.

The autofocus device 1510 may include an autofocus function using a laser. The autofocus device 1510 can be mainly used in conditions where the autofocus function using the image of the camera module 1520 is deteriorated, for example, in close proximity of 10 m or less or in dark environments. The autofocus device 1510 may include a light emitting unit including a surface light emission laser element and a light receiving unit such as a photo diode that converts light energy into electrical energy.

The above detailed description should not be construed as restrictive in any respect and should be considered 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-emissive area
270: Passivation layer
290: Pad electrode
E: Light-emitting structure
E1, E2, E3: Emitters
W1, W2: Width

Claims (10)

Board;
A surface light emitting laser device disposed on the substrate;
a housing disposed around the surface light emitting laser element;
a diffusion portion disposed on the surface light-emitting laser device; and
It includes a wavelength limiting member disposed on the surface light emitting laser element,
The surface light emitting laser device,
When operating in the first mode, emitting first light having a first wavelength band,
When operating in the second mode, a second light is shifted from the first wavelength band and emits a second light having a second wavelength band larger than the first wavelength band,
The wavelength limiting member is,
Transmitting the first light having the first wavelength band,
Blocking the second light having at least the second wavelength band,
The intensity of the second light is greater than the intensity of the first light.
Surface light emitting laser package. According to paragraph 1,
The peak wavelength of the second wavelength band is the same as the peak wavelength of the first wavelength band,
A surface light emitting laser package wherein the half width of the second wavelength band is greater than or equal to the half width of the first wavelength band. According to paragraph 2,
A surface light emitting laser package wherein the half width of the second wavelength band is 1 to 3 times the half width of the first wavelength band. According to paragraph 2,
The peak wavelength of the first wavelength band and the peak wavelength of the second wavelength band are 940 nm,
The half width of the first wavelength band is 4 nm,
A surface light emitting laser package wherein the half width of the second wavelength band is 10 nm. According to paragraph 1,
The surface light emitting laser device,
When operating in the first mode, output a first light having a first output power,
A surface light emitting laser package that outputs a second light having a second output power greater than the first output power when operating in the second mode. According to paragraph 1,
The wavelength limiting member is a surface light emitting laser package including an infrared passing filter. According to paragraph 1,
The wavelength limiting member is a surface light emitting laser package including a multilayer thin film. According to paragraph 1,
A surface light emitting laser package wherein the wavelength limiting member is disposed on an upper side of the diffusion unit. According to paragraph 1,
A surface light emitting laser package wherein the wavelength limiting member is disposed on a lower side of the diffusion portion. The surface light emitting laser package according to any one of claims 1 to 9; and
An autofocus device including a light receiving unit that receives reflected light from the surface light emitting laser package.