CN113540963A

CN113540963A - Laser assembly

Info

Publication number: CN113540963A
Application number: CN202010319194.7A
Authority: CN
Inventors: 田有良; 周子楠; 张昕; 卢云琛
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2020-04-21
Filing date: 2020-04-21
Publication date: 2021-10-22
Anticipated expiration: 2040-04-21
Also published as: CN113540963B

Abstract

The application discloses laser subassembly belongs to the photoelectric technology field. The laser assembly includes: the heat sink is attached to the bottom plate, and the light-emitting chip is attached to the other side, far away from the bottom plate, of the heat sink; the light emitting chip is sequentially provided with a first electrode, a light emitting structure and a second electrode along the direction far away from the bottom plate, the first electrode is provided with a convex-concave surface, and the heat sink is in contact with the convex-concave surface. This application can improve the heat conduction efficiency of emitting chip.

Description

Laser assembly

Technical Field

The application relates to the field of photoelectric technology, in particular to a laser assembly.

Background

With the development of the optoelectronic technology, the laser is widely used.

As shown in fig. 1, a laser assembly in a laser may include a base plate 001, a heat sink 002 attached to the base plate 001, and a light emitting chip 003 attached to a side of the heat sink 002 away from the base plate 001. Heat generated by the light emitting chip 003 during light emission can be conducted to the outside through the heat sink 002, so that the light emitting chip 003 is prevented from being damaged by the heat accumulation.

However, the current light emitting chip has poor heat conduction effect, thereby affecting the light emitting power.

Disclosure of Invention

The application provides a laser assembly, can solve the relatively poor problem of luminous chip heat conduction effect in the laser assembly.

In one aspect, there is provided a laser assembly comprising: .

The heat sink is attached to the bottom plate, and the light-emitting chip is attached to the other side, far away from the bottom plate, of the heat sink; the light emitting chip is sequentially provided with a first electrode, a light emitting structure and a second electrode along the direction far away from the bottom plate, the first electrode is provided with a convex-concave surface, and the heat sink is in contact with the convex-concave surface.

The beneficial effect that technical scheme that this application provided brought includes at least:

in the laser subassembly that this application provided, in the luminescence chip with the heat sink the contact surface be convex-concave surface, the area of contact surface is great when making the heat transfer, thereby the luminescence chip can be through great area heat conduction heat to the heat sink, can improve heat conduction speed, improve luminescence chip heat conduction efficiency, and, because first electrode is more close to the luminous region in the light-emitting structure, can carry out the heat transfer with shorter route, also can accelerate heat conduction, do benefit to the heat dissipation of luminescence chip.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a laser module provided in the related art;

fig. 2 is a schematic structural diagram of a laser module according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a light emitting chip provided in an embodiment of the present application;

fig. 4 is a schematic structural diagram of another light emitting chip provided in the embodiment of the present application;

fig. 5 is a schematic structural diagram of another light emitting chip provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of a further laser assembly provided in an embodiment of the present application;

fig. 7 is a schematic partial structural diagram of a laser module according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of another laser assembly provided in embodiments of the present application;

fig. 9 is a schematic structural diagram of another laser assembly provided in an embodiment of the present application;

fig. 10 is a schematic structural diagram of a laser according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

With the development of the optoelectronic technology, the application of the laser with larger output power is wider and wider, for example, the laser can be applied to the aspects of welding process, cutting process, laser projection and the like. The light emitting chip in the laser usually generates much heat during the light emitting process, and the heat is an important factor causing the light emitting chip to be damaged, so how to quickly conduct the heat to the outside becomes a research focus in the field of the laser at present. The embodiment of the application provides a laser assembly, which can improve the heat conduction rate of a light-emitting chip and further ensure the service life of the laser assembly.

Fig. 2 is a schematic structural diagram of a laser module according to an embodiment of the present disclosure. As shown in fig. 2, the laser assembly 10 includes: the LED lamp comprises a bottom plate 101, a heat sink 102 and a light emitting chip 103, wherein the heat sink 102 is attached to the bottom plate 101, and the light emitting chip 103 is attached to the side, away from the bottom plate 101, of the heat sink 102. The contact surface of the light emitting chip 103 with the heat sink 102 is non-planar, and for example, the contact surface is a convex-concave surface or a rough surface.

In summary, in the laser device assembly provided by the embodiment of the present application, the contact surface between the light emitting chip and the heat sink is non-planar and is convex-concave, so that the contact area between the surface and other interfaces is relatively large, and the contact area between the light emitting chip and the heat sink is relatively large. Furthermore, the light emitting chip can conduct heat to the heat sink through a large area, so that the heat conduction speed can be increased, and the effect of conducting heat through the heat sink by the light emitting chip is improved.

With continued reference to fig. 2, the laser assembly 10 may further include at least one reflective prism 104 attached to the base plate 101, each reflective prism 104 may correspond to one or more light emitting chips 103, and each reflective prism 104 is located at the light emitting side of the corresponding light emitting chip 103. The light emitting chips 103 are configured to emit light to the corresponding reflection prisms, and each reflection prism 104 is configured to emit the light emitted from the corresponding light emitting chip 103 in a direction away from the bottom plate 101. For example, a surface of each of the reflection prisms facing the corresponding light emitting chip may be a light reflection surface for reflecting light emitted from the light emitting chip.

It should be noted that the laser assembly 10 may include a plurality of heat sinks 102, a plurality of light emitting chips 103, and a plurality of reflecting prisms 104, and fig. 2 shows only two heat sinks 102, two light emitting chips 103, and two reflecting prisms 104. Alternatively, the number of the heat sink, the light emitting chip, and the reflection prism may be 6, 10, 20, or other numbers. Alternatively, the heat sinks and the light emitting chips in the laser assembly may correspond one to one, and each light emitting chip may be attached to one heat sink. Alternatively, the reflecting prisms and the light emitting chips may also correspond one to one.

Optionally, in the embodiment of the present application, each heat sink may also correspond to at least two light emitting chips. The arrangement direction of the at least two light-emitting chips is perpendicular to the arrangement direction of the at least two light-emitting chips and the corresponding reflecting prisms, and the at least two light-emitting chips are adjacent to each other. Optionally, each reflection prism may correspond to at least two light emitting chips. The at least two light emitting chips may be located at the same side of the corresponding reflection prism, and the at least two light emitting chips are adjacent. The arrangement direction of the at least two light emitting chips is perpendicular to the light emitting direction (x direction in fig. 2) of the light emitting chips. Therefore, the reflecting prism is close to the reflecting surface of the corresponding light-emitting chip and can be used for reflecting the laser emitted by the at least two light-emitting chips. Optionally, the at least two light emitting chips may also be located on different sides of the reflective prism. For example, the reflecting surface of the reflecting prism located on each of the two sides can be used for reflecting the laser emitted by the light emitting chip on the side.

The contact surface comprises a plurality of depressed areas depressed in a direction away from the heat sink and a plurality of raised areas outside the depressed areas, thereby making the contact surface non-planar. It should be noted that the concave region and the convex region on the surface are opposite, the concave region is a region concave relative to the convex region, and the convex region is a region convex relative to the concave region. For example, as shown in fig. 2, a surface of the light emitting chip 103 close to the bottom plate 101 (i.e., a contact surface of the light emitting chip 103 with the heat sink 102) may include a plurality of concave regions, and accordingly, the contact surface may further include a plurality of convex regions. The individual concave regions and the individual convex regions may be uniformly distributed or may also be randomly distributed, or the concave regions or the groove regions may form a specific pattern, which is not limited in the embodiments of the present application.

Optionally, the absolute value of the height difference between the concave area and the convex area in the contact surface of the light-emitting chip and the heat sink can be in a range of 0.5-10 micrometers.

With continued reference to fig. 2, the light emitting chip 103 may include a first electrode 1031, a light emitting structure 1032 and a second electrode 1033 sequentially stacked in a direction away from the bottom plate 101 (e.g., y direction in fig. 2), and the first electrode 1031 and the second electrode 1033 may be connected to an external power source to excite the light emitting structure 1032 to emit light. A surface of the light emitting structure 1032 near the base plate 101 may have a plurality of grooves, and the first electrode 1031 may be laid on the surface of the light emitting structure 1032 near the base plate. Since the first electrode is deposited on the structure by a thin metal film, the surface of the first electrode 1031 close to the bottom plate 101 may be a convex-concave surface. The surface of the first electrode 1031 close to the bottom plate 101, that is, the surface of the first electrode 1031 far from the light emitting structure 1032, that is, the contact surface with the heat sink in the light emitting chip.

Illustratively, the plurality of grooves may include a plurality of grooves F1. Each of the grooves F1 may be used to form a recessed region in the surface of the first electrode 1031 proximate to the bottom plate 101, and correspondingly, regions other than the grooves F1 may be used to form raised regions in the surface. For example, the light emitting structure 1032 may be formed first, and then a plurality of grooves F1 may be formed on one surface of the light emitting structure 1032. Then, the first electrode 1031 is laid on the surface having the groove F1, a region of the first electrode 1031 contacting with the groove F1 is recessed toward the light emitting structure 1032, and further, the region of the surface of the first electrode 1031 away from the light emitting structure 1032 may be a recessed region, and a region other than the recessed region may be a convex region. Alternatively, the groove F1 may be formed by roughening the surface of the light emitting structure, for example, by using an etching process.

Further illustratively, the plurality of projections may include a plurality of projections F2. Each protrusion F2 may be used to form a raised region in the surface of the first electrode 1031 proximate to the bottom plate 101, and correspondingly, regions other than the protrusion F2 may be used to form recessed regions in the surface. For example, the light emitting structure 1032 may be formed first, and then a plurality of protrusions F2 may be formed on one surface of the light emitting structure 1032. Then, the first electrode 1031 is laid on the surface having the protrusion F2, a region of the first electrode 1031 in contact with the protrusion F2 protrudes in a direction away from the light emitting structure 1032, a region of the first electrode 1031 not in contact with the protrusion F2 is recessed toward the light emitting structure, and thus the surface of the first electrode 1031 away from the light emitting structure 1032 has a recessed region and a protruding region. Alternatively, the protrusions F2 may be formed by a coating process, such as spraying micro-particles onto the light emitting structure. It should be noted that micro-scale may refer to micron-scale dimensions, and micro-particles may refer to particles having a diameter on the micron-scale.

As another example, the plurality of protrusions may include a plurality of grooves and a plurality of protrusions. For example, a plurality of grooves may be formed on the light emitting structure, and then a plurality of protrusions may be formed on the surface on which the grooves are formed, or a plurality of protrusions may be formed on the light emitting structure, and then a plurality of grooves may be formed on the surface on which the protrusions are formed. The manner of forming the grooves and the protrusions may refer to the above description of the grooves F1 and the protrusions F2, and the description of the embodiments of the present application is omitted.

It should be noted that, in the embodiment of the present application, the first electrode covers the entire surface of the light emitting structure close to the bottom plate, and the second electrode covers the entire surface of the light emitting structure far from the bottom plate. Alternatively, the first electrode may cover only a partial region of the surface of the light emitting structure close to the base plate, and the second electrode may cover only a partial region of the surface of the light emitting structure far from the base plate, such as a middle region of the surface.

Optionally, the thickness of the first electrode may be in a range of 50 nm to 300 nm, for example, the thickness of the first electrode is 200 nm. Optionally, when the plurality of protrusions include a plurality of grooves, such as a plurality of grooves formed on the light emitting structure, the depth of the grooves may range from 0.5 micrometers to 10 micrometers. Because the thickness of the first electrode is thin, the first electrode cannot fill the groove smoothly, the region of the first electrode corresponding to the groove is recessed towards the light-emitting structure, and the surface of the first electrode away from the light-emitting structure is a convex-concave surface. Optionally, when the plurality of protrusions includes a plurality of protrusions, such as when the plurality of protrusions are formed on the light emitting structure, the height of the protrusions may range from 0.5 micrometers to 10 micrometers. Because the thickness of the first electrode is smaller than the absolute depth of the groove or the recess, the recess between the protrusions cannot be filled smoothly by the first electrode, the region of the first electrode corresponding to the recess is recessed toward the light emitting structure, and the surface of the first electrode away from the light emitting structure is a convex-concave surface.

Optionally, the absolute value of the thickness difference of each position of the first electrode may be less than or equal to a thickness threshold, so that the first electrode is ensured to be a thin film with a relatively uniform thickness, and the current conduction efficiency of the first electrode is ensured. For example, the thickness threshold may be 5 nm or 10 nm or other values; or the thickness threshold is 0 nm, that is, the thickness of each position of the first electrode is the same.

Fig. 3 is a schematic structural diagram of a light emitting chip provided in an embodiment of the present application, and the light emitting chip shown in fig. 3 may be a left side view of the light emitting chip shown in fig. 2. As shown in fig. 3, the light emitting chip 103 may include a first electrode 1031, a light emitting structure 1032 and a second electrode 1033 sequentially stacked in a direction away from the bottom plate (e.g., y direction in fig. 3). Note that the base plate is not illustrated in fig. 3, and the z direction in fig. 3 is perpendicular to the x direction and the y direction. For example, the z direction may be an arrangement direction of at least two chips adjacent to each other and corresponding to the same reflection prism. The light emitting structure 1032 may include: a substrate 1032a, a second semiconductor layer 1032b, an active layer 1032c, a first semiconductor layer 1032d, and an insulating layer 1032e, which are stacked in this order in a direction away from the bottom plate, the insulating layer 1032e covering a part of a region in the first semiconductor layer 1032 d. A surface of the first semiconductor layer 1032d remote from the substrate 1032a may have a protrusion T, a thickness of the insulating layer 1032e may be smaller than a height of the protrusion T, and the insulating layer 1032e may not cover the surface of the protrusion T remote from the substrate 1032 a. The light emitting structure 1032 includes a substrate 1032a in contact with the first electrode 1031, that is, the substrate 1032a may be disposed near the bottom plate, and a surface of the substrate 1032a near the bottom plate may have a plurality of protrusions or a plurality of grooves. The light emitting chip shown in fig. 3 is attached to the heat sink in such a manner that the substrate is close to the bottom plate, and the light emitting chip may be referred to as a light emitting chip of a front-mount structure.

It should be noted that fig. 3 illustrates that the protrusions are distributed on the entire surface of the substrate 1032a close to the bottom plate, and thus the entire surface of the first electrode 1031 close to the bottom plate is non-planar. Alternatively, the protrusions may be only distributed in a partial area of the surface of the substrate close to the bottom plate, and an orthogonal projection of the partial area on the bottom plate may cover an orthogonal projection of another partial area of the first semiconductor layer on the bottom plate, where the another partial area is an area not covered by the insulating layer in the first semiconductor layer.

In the above scheme, the first electrode 1031 is attached to the substrate 1032a, and the first electrode is an N-pole. The active layer is a light emitting area of the laser chip and can generate a large amount of heat in the light emitting process, in the scheme, the heat generated by the light emitting of the active layer is transferred towards the direction of the second semiconductor layer and the direction of the substrate, finally the heat is transferred to the heat sink through the substrate and is conducted to the bottom plate through the heat sink, and the bottom plate is usually made of metal copper materials and has good heat conducting performance.

Fig. 4 is a schematic structural diagram of another light emitting chip provided in an embodiment of the present application, and the light emitting chip shown in fig. 4 may be a left side view of the light emitting chip shown in fig. 2. As shown in fig. 4, the light emitting chip 103 may include a first electrode 1031, a light emitting structure 1032 and a second electrode 1033 sequentially stacked in a direction away from the bottom plate (e.g., y direction in fig. 4). The structure of the light emitting structure 1032 in fig. 4 is the same as the structure of the light emitting structure 1032 in fig. 3, and the description of the embodiment of the present application is omitted. The insulating layer 1032e in the light emitting structure 1032 of the light emitting chip 103 shown in fig. 4 is in contact with the first electrode 1031, that is, the insulating layer 1032e is disposed near the bottom plate, and the other partial region of the first semiconductor layer 1032d, that is, the region of the first semiconductor layer 1032d not covered by the insulating layer 1032e, has a plurality of protrusions on the surface near the bottom plate 101. If the surface of the first semiconductor layer 1032d having the projections T away from the substrate 1032a is not covered with the insulating layer 1032e, the surface may have a plurality of projections. The light emitting chip shown in fig. 4 is attached to the heat sink in such a manner that the insulating layer is close to the bottom plate, and the light emitting chip may be referred to as a flip-chip light emitting chip.

It should be noted that in fig. 4, the surface of another partial region of the first semiconductor layer 1032d close to the bottom plate has a plurality of grooves, and then a partial region of the surface of the first electrode 1031 close to the bottom plate forms a convex-concave surface. Optionally, a surface of the insulating layer away from the substrate may also have a protrusion, and then the entire surface of the first electrode close to the bottom plate may be a non-planar surface, which is not illustrated in this embodiment of the application. The light emitting chips in fig. 3 and 4 may be referred to as ridge type light emitting chips.

In the above embodiment, the first electrode 1031 is attached to a surface region of the first semiconductor 1032d close to the bottom plate and not covered by the insulating layer 1032e, the first semiconductor is a P-type semiconductor, and the first electrode is a P-electrode.

In the above solution, heat generated by light emission of the active layer is transferred along the first semiconductor layer and the insulating layer, and finally the heat is transferred to the heat sink in contact with the first electrode 1031 and is conducted to the bottom plate through the heat sink, and the bottom plate is usually made of a metal copper material and has a good thermal conductivity. In addition, in the embodiment, since the P-type semiconductor layer and the P-electrode are closer to the active layer 1032c, the heat generated by the active layer 1032c can be conducted away by a shorter heat conduction path, which is more beneficial to heat dissipation.

Optionally, fig. 5 is a schematic structural diagram of another light emitting chip provided in this embodiment of the present application, and fig. 6 is a schematic structural diagram of another light emitting chip provided in this embodiment of the present application. The light emitting chip shown in fig. 5 may be arranged in the same manner as the respective film layers in the light emitting chip shown in fig. 3, and the light emitting chip shown in fig. 6 may be arranged in the same manner as the respective film layers in the light emitting chip shown in fig. 4, but the thickness of the insulating layer 1032e in the light emitting structure 1032 of the light emitting chip shown in fig. 5 may be equal to the height of the bump T. The light emitting chips shown in fig. 5 and 6 may be referred to as gain waveguide stripe light emitting chips.

It should be noted that the arrangement manner of the protrusions in the light emitting structure in fig. 5 may be the same as the arrangement manner of the protrusions in fig. 3, and the arrangement manner of the protrusions in the light emitting structure in fig. 6 may be the same as the arrangement manner of the protrusions in fig. 4, which is not described again in this embodiment of the present application. In the laser assembly, the light emitting chip 103 in fig. 3 and the light emitting chip 103 in fig. 5 may be replaced with each other, and the light emitting chip 103 in fig. 4 and the light emitting chip 103 in fig. 6 may also be replaced with each other, and the arrangement of the light emitting chips in fig. 5 and fig. 6 in the laser assembly is not described in detail in this embodiment of the present application.

Optionally, in the embodiment of the present application, the protrusion of the first semiconductor layer in the light emitting chip may be in a frustum shape or a quadrangular prism shape, and fig. 3 and 4 take the frustum shape of the protrusion as an example, and fig. 5 and 6 take the quadrangular prism shape of the protrusion as an example.

In the light emitting chip of the embodiment of the application, the second semiconductor layer may be made of an N-type semiconductor (also referred to as an electronic semiconductor); the first semiconductor layer may be a P-type semiconductor (also referred to as a hole-type semiconductor). An electrode in the light-emitting chip, which is in contact with the second semiconductor layer, is an N electrode, namely a negative electrode; the electrode in contact with the first semiconductor layer is a P electrode, i.e., a positive electrode. The light emitting structure may further include an N-type cladding layer between the second semiconductor layer and the active layer, and a P-type cladding layer between the first semiconductor layer and the active layer, which may also be referred to as a bound photon (wave guide) layer.

It should be noted that the light emitting chip is an optoelectronic device that emits coherent radiation light by current injection. The light emitting chip shown in fig. 3 is taken as an example, and the light emitting principle of the light emitting chip will be described.

For example, in the light emitting chip shown in fig. 3, the first electrode is an N-electrode, and the second electrode is a P-electrode. The first electrode may be connected to a positive electrode of an external power source, and the second electrode may be connected to a negative electrode of the external power source to inject current into the light emitting structure. Under the action of the current, electrons in the second semiconductor layer move to the active layer, and holes in the first semiconductor layer move to the active layer so as to increase the density of the electrons and the holes in the active layer, and then the electrons and the holes in the active layer are recombined to excite photons. The photons are oscillated and reflected between the P-type cladding layer and the N-type cladding layer on both sides of the active layer, so that the radiation energy of the photons is increased, and further, laser light is output from the side surface of the active layer. Since the second electrode only covers the other partial region in the first semiconductor layer, holes can be injected into the active layer only in the other partial region in the first semiconductor layer, and then the partial region corresponding to the other partial region in the active layer can emit light. The orthographic projection of the partial area in the active layer on the bottom plate is positioned in the orthographic projection of the other partial area in the first semiconductor layer on the bottom plate, and the actual light-emitting area in the light-emitting chip is the partial area in the active layer.

The actual light-emitting area in the light-emitting chip generates heat when emitting light, and the heat is conducted in the arrangement direction of the film layer in the light-emitting chip, so that the heat can be conducted to the heat sink through the partial area of the first electrode corresponding to the actual light-emitting area. The orthographic projection of the partial area in the first electrode on the base plate may coincide with the orthographic projection of the actual light emitting area on the base plate. In the embodiment of the present application, the protrusions may be distributed only in the partial region of the light emitting structure (e.g., the arrangement manner of the protrusions in fig. 4 and 6), and then only the partial region of the first electrode is non-planar, so that the heat dissipation area of the light emitting chip may be ensured to be large, and the conduction speed of the heat generated by the light emitting chip may be increased. Because the heat can be conducted in other directions, in the embodiment of the present application, the protrusions can be distributed on the entire surface of the light emitting structure close to the bottom plate (e.g., the protrusion arrangement manner in fig. 3 and 5), and further, each region in the first electrode is non-planar, so that the heat dissipation area of the light emitting chip can be further increased, and the conduction speed of the heat generated by the light emitting chip can be increased.

It should be noted that, as can be seen from the structures of the light emitting chips in fig. 3 to 6, the actual light emitting region of the light emitting chip is located in the active layer, and the electrode located on the side of the insulating layer away from the substrate among the two electrodes of the light emitting chip is closer to the active layer; therefore, the electrode is contacted with the heat sink (namely, the light-emitting chip adopting the inverted structure shown in figure 3 or figure 5), so that the heat generated by the actual light-emitting area during light emitting can be conducted to the heat sink through a smaller distance, the heat can be more timely and rapidly conducted to the outside through the heat sink, and the effect of the heat conduction of the light-emitting chip through the heat sink can be further improved.

Alternatively, as shown in fig. 5 and 6, the surface of the first semiconductor layer 1032d away from the substrate may have two protrusions T thereon, and a region of the first semiconductor layer 1032d not covered by the insulating layer 1032e may include two independent regions, which may be the surfaces of the two protrusions T away from the substrate 1031a, respectively. Thus, the light emitting chip 103 may have two actual light emitting areas, and the light emitting chip may emit two laser beams. Alternatively, each actual light emitting region may have a width of 75 micrometers in the z-direction. The spacing of the two actual light emitting areas may be 120 microns. The first semiconductor layer in the light emitting chip shown in fig. 5 and 6 may also have only one bump, and the embodiment of the present application is not limited. It should be noted that the first semiconductor layer in the light emitting chip shown in fig. 3 and 4 may also have two protrusions, and surfaces of the two protrusions away from the substrate may not be covered by the insulating layer, so that the light emitting chip has two actual light emitting areas to emit two beams of laser light, which is not limited in the embodiment of the present application.

The laser module may include a light emitting chip for emitting red light, a light emitting chip for emitting green light, and a light emitting chip for emitting blue light. Generally, each laser beam emitted by the laser assembly needs to be mixed into white light, and when the white light is obtained by mixing red light, green light and blue light, the proportion of the red light needs to be larger, for example, the proportion of the red light, the green light and the blue light in the white light is 2:1: 1. Therefore, the light emitting chip for emitting red light in the laser assembly provided by the embodiment of the present application may have two actual light emitting areas, and the light emitting chip for emitting blue light and the light emitting chip for emitting green light may have one actual light emitting area.

The following describes a method for manufacturing the light-emitting chip:

when the light emitting chip is manufactured, a substrate may be provided, and the material of the substrate is related to the color of the laser light emitted from the light emitting chip, for example, the material of the substrate may include gallium nitride, or other materials. And then an N-type semiconductor layer (namely, a second semiconductor layer), an active layer and a P-type semiconductor layer (namely, a first semiconductor layer) can be grown on the surface of the substrate in sequence by means of crystal growth. For example, the material of the first semiconductor layer may include Indium Tin Oxide (ITO) or other P-type semiconductor materials. Then, the first semiconductor layer may be etched, so that the surface of the etched first semiconductor layer, which is away from the substrate, has one or two protrusions. And then, forming an insulating layer on the first semiconductor layer with the protrusion, so that the insulating layer covers other areas except the surface of the protrusion far away from the substrate in the first semiconductor layer. For example, the insulating layer may comprise silicon dioxide or other insulating materials. Then, the surface of the projection far away from the substrate can be etched to form a groove on the surface; or coating micro-particles on the surface to form projections (such as micro-projections) on the surface, thereby obtaining the light emitting structure of the light emitting chip in fig. 3 or fig. 5. Or, the surface of the substrate far away from the second semiconductor layer can be etched to form a groove on the surface; or the surface is coated with micro-particles to form projections (e.g., micro-projections) on the surface, thereby obtaining the light emitting structure of the light emitting chip in fig. 4 or fig. 6. Finally, a metal film can be evaporated on the side of the protrusion far away from the substrate and the side of the substrate far away from the second semiconductor layer to form a first electrode and a second electrode, so that the light-emitting chip is manufactured. Optionally, the overall thickness of the light emitting chip may be in a range of 40 micrometers to 100 micrometers, such as 80 micrometers.

Heat sinks in laser assemblies are described below:

fig. 7 is a schematic partial structure diagram of a laser module according to an embodiment of the present disclosure, where the light emitting chip 103 in fig. 7 may be any one of the light emitting chips described above, and fig. 7 illustrates a non-planar surface of the light emitting chip 103 close to the base plate 101. As shown in fig. 7, the heat sink 102 includes: a heat dissipation substrate 1021, a solder resist layer 1022, a conductive layer 1023, and a solder layer 1024, which are stacked in this order in a direction away from the base plate (e.g., the y direction in fig. 7). The heat dissipation substrate 1021 has a high thermal conductivity, and is used for rapidly transferring heat generated by the light emitting chip 103 to the outside. The solder layer 1024 is used for soldering the light emitting chip 103. The conductive layer 1023 is used for electrical connection with the light emitting chip 103 through a solder layer 1024. For example, an external power source may be connected to the conductive layer through a wire, so that the first electrode is connected to the external power source through the solder layer and the conductive layer. The solder resist layer 1022 does not react with the heat dissipation substrate 1021 nor with the conductive layer 1023. The solder resist layer 1022 is used to prevent ions in the conductive layer 1023 from diffusing to the heat dissipation substrate 1021, and to avoid an influence on the characteristics of the heat dissipation substrate 1021.

Alternatively, the heat dissipation substrate may be made of a ceramic such as aluminum nitride or silicon carbide. It should be noted that the ceramic has good thermal conductivity, high heat dissipation efficiency and good thermal stability, and the heat sink prepared by using the ceramic can improve the effect of heat conduction of the heat sink to the light-emitting chip. Optionally, the material of the heat dissipation substrate may also include copper. Optionally, the material of the solder layer may include solder. Alternatively, the material of the conductive layer may include gold, silver, or other metals. Optionally, the material of the solder mask layer may include at least one of platinum, palladium, a titanium platinum mixture and a copper nickel gold mixture.

When assembling heat sink and luminescence chip, can place luminescence chip on the solder layer of heat sink, and then can heat the solder layer to make the solder layer melt and then fully contact with luminescence chip's first electrode. The melted solder layer can be contacted with the non-planar surface of the first electrode close to the bottom plate (namely, the contact surface of the light-emitting chip and the heat sink), and can also be filled into the concave area of the light-emitting chip. After the solder layer is solidified, the assembly of the heat sink and the light emitting chip can be completed.

Alternatively, with continued reference to fig. 2 or fig. 7, one end of the light emitting chip 103 near the reflective prism 104 may protrude out of one end of the heat sink 102 near the reflective prism 104. Alternatively, the length of the portion of the light emitting chip protruding from the heat sink in the arrangement direction of the light emitting chip and the corresponding reflection prism (e.g., x direction in fig. 2 and 7) may be less than 15 μm. It should be noted that, because the laser emitted by the light emitting chip has a divergence angle, the light emitting chip protrudes out of the heat sink, so that the distance between the light emitting chip and the reflection prism is short, and further, the light emitted by the light emitting chip is ensured to be emitted to the reflection prism more, and the light waste caused by the emission of the laser emitted by the light emitting chip to the bottom plate is avoided, so that the light brightness emitted by the laser assembly can be high.

Optionally, there may also be a portion of the light emitting chips in the laser assembly, where one end of the light emitting chip close to the reflection prism is flush with one end of the heat sink close to the reflection prism, or one end of each light emitting chip in the laser assembly, where the one end of each light emitting chip close to the reflection prism is flush with one end of the heat sink close to the reflection prism, which is not limited in this embodiment of the application. When the one end that the chip of giving out light is close to reflection prism and the heat sink is close to reflection prism's one end parallel and level, the area of contact of the chip of giving out light and heat sink is great, and then has increased the regional area that is supported by the heat sink in the chip of giving out light, has improved the steadiness that sets up of the chip of giving out light. Moreover, the contact area between the light-emitting chip and the heat sink is large, so that the effect of heat conduction of the light-emitting chip through the heat sink can be further improved, and the heat dissipation effect of the light-emitting chip is improved.

Fig. 8 is a schematic structural diagram of another laser module provided in the embodiments of the present application. As shown in fig. 8, the laser assembly 10 may include: a bottom plate 101, a plurality of heat sinks 102, and a plurality of light emitting chips 103 arranged in an array. The plurality of heat sinks 102 can be attached to the bottom plate 101, the heat sink 102 corresponds to at least one light emitting chip 103, and the light emitting chip 103 is attached to one side of the corresponding heat sink 101, which is far away from the bottom plate; the contact surface of the light emitting chip 103 with the heat sink 102 is non-planar.

Optionally, fig. 2 may be a partial cross-sectional schematic view of a cross section a-a' of the laser assembly shown in fig. 8, and in fig. 8, the heat sink 102 and the light emitting chip 103 may both refer to the related descriptions of the heat sink 102 and the light emitting chip 103 in fig. 2 to 7, and the description of the embodiment of the present application is omitted. Fig. 8 illustrates an example in which the laser module includes 20 light emitting chips 103, and the 20 light emitting chips 103 are arranged in four rows and five columns, and the 20 light emitting chips 103 can all emit light in the x direction. The x direction in fig. 8 may be a column direction of the plurality of light emitting chips, the z direction may be a row direction of the plurality of light emitting chips, and the x direction is perpendicular to the z direction. Optionally, the number of the light emitting chips 203 in the laser assembly may also be 16, 25 or another number, and the embodiment of the present application is not limited.

Fig. 9 is a schematic structural diagram of another laser module according to an embodiment of the present disclosure. Fig. 9 may be a top view of a laser assembly. As shown in fig. 9, the laser assembly may include a plurality of light emitting chips 103 and corresponding heat sinks (heat sinks not shown in fig. 9), and at least one reflective prism 104. The reflection prism 104 may be located at a middle area of the base plate 101, and the light emitting chip 103 and the corresponding heat sink may be located at an edge area of the base plate 101, which surrounds the middle area. For example, the plurality of light emitting chips 103 in the laser assembly may enclose a rectangle and enclose the corresponding reflective prism 104. It should be noted that fig. 9 exemplifies that the laser assembly includes 16 light emitting chips 103, and each 4 light emitting chips 103 are located on one side of the rectangle. Optionally, the number of the light emitting chips on each side of the rectangle may also be 5 or 6 or other values, and the number of the light emitting chips on different sides of the rectangle may also be different, which is not limited in this embodiment of the application.

It should be noted that fig. 9 exemplifies that the laser assembly includes only one reflection prism, and the light emitting chips in the laser assembly all correspond to the same reflection prism. As shown in fig. 9, the reflecting prism is in a regular quadrangular frustum shape, and four side surfaces of the regular quadrangular frustum can be reflecting surfaces, and each reflecting surface is used for reflecting the laser light emitted by the light emitting chip to the reflecting surface and emitting the laser light in a direction away from the bottom plate. Optionally, each light emitting chip may also correspond to an independent reflection prism. At this time, each reflection prism may enclose a rectangle, and a light emitting chip and a corresponding reflection prism may be further disposed in an area enclosed by each reflection prism, which is not limited in the embodiment of the present application.

Optionally, the reflection prism may also be located in an edge area of the bottom plate, and the light emitting chip and the corresponding heat sink are located in a middle area of the bottom plate, which is not limited in the embodiment of the present application.

It should be noted that fig. 9 is only used to illustrate an optional arrangement manner of the light emitting chips in the laser assembly, and reference may be made to fig. 2 to fig. 7 for structures included in the laser assembly and features of any structure, which is not described in detail in this embodiment of the application.

Fig. 10 is a schematic structural diagram of a laser according to an embodiment of the present application. As shown in fig. 10, the laser may include: any of the laser assemblies 10 described above, a package 105, a sealed light transmitting layer 106, a cover 107 and a collimating lens 108. Fig. 10 is a schematic view of the laser module 10 as an example of the laser module shown in fig. 2. The housing 105 may be annular and attached to the base plate 101. The upper cover 107 may have a ring shape, and a middle region of the upper cover 107 is recessed toward the base plate 101. The edge region of the upper cover 107 is fixed to the surface of the housing 105 remote from the base plate 101. The light-transmitting sealant 106 is located on the side of the middle region of the upper cover 107 away from the bottom plate 101, and the light-transmitting sealant 106 is fixed to the package 105 through the upper cover 107. The package 105, the light transmissive sealing layer 106, the upper cover 107, and the bottom plate 101 may form a sealed space, and the heat sink 102, the light emitting chip 103, and the reflection prism 104 may be located in the sealed space. Optionally, the sealed space may be filled with an inert gas, such as nitrogen, to protect the light emitting chip from being oxidized. Fig. 10 does not show the specific film layer and the non-planar form of the contact surface in the light emitting chip 103, the light emitting chip in fig. 10 may be any of the light emitting chips described above, and the heat sink may be the heat sink shown in fig. 7.

Alternatively, with continued reference to fig. 10, the collimating lenses 108 in the laser may correspond to the light emitting chips 103 one by one, and the collimating lenses 108 may be located on the surface of the light-transmitting sealing layer 106 away from the bottom plate 101. The light emitted by each light emitting chip 103 is reflected by the corresponding reflection prism 104 and then emitted to the corresponding collimating lens 108, and the collimating lens 108 can collimate the light and then emit the light out of the laser. Optionally, the plurality of collimating lenses may be integrally formed, or the plurality of collimating lenses may also be independent of each other, which is not limited in the embodiments of the present application. It should be noted that fig. 10 illustrates the plurality of collimating lenses 108 integrally formed and located on the side of the light-transmissive sealing layer 106 away from the base plate 101; optionally, the collimating lens may also be located in the sealed space, and the embodiment of the present application is not limited.

Alternatively, the edge of the light-transmitting sealant 106 may be adhered to the surface of the package 105 away from the substrate 101, so that only the package 105, the light-transmitting sealant 106, and the substrate 101 may form a sealed space, and the laser may not include the upper cover 107.

In summary, in the laser device assembly provided in the embodiment of the present application, the contact surface between the light emitting chip and the heat sink is not a plane, so the area of the contact surface is large, and the contact area between the light emitting chip and the heat sink is large. Furthermore, the light emitting chip can conduct heat to the heat sink through a large area, so that the heat conduction speed can be increased, and the effect of conducting heat through the heat sink by the light emitting chip is improved.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A laser assembly, comprising: the heat sink is attached to the bottom plate, and the light-emitting chip is attached to the other side, far away from the bottom plate, of the heat sink; the light emitting chip is sequentially provided with a first electrode, a light emitting structure and a second electrode along the direction far away from the bottom plate, the first electrode is provided with a convex-concave surface, and the heat sink is in contact with the convex-concave surface.

2. The laser assembly of claim 1,

the structure surface attached with the first electrode in the light-emitting structure is provided with a groove, the first electrode is a metal film and is attached to the surface in an evaporation mode, and the first electrode presents a convex-concave surface.

3. The laser assembly of claim 2,

the thickness range of the first electrode is 50-300 nanometers, and the depth of the groove is 0.5-10 micrometers.

4. The laser assembly of claim 2, wherein the light emitting structure comprises: the substrate, the second semiconductor layer, the active layer, the first semiconductor layer and the insulating layer are sequentially stacked along the direction close to the bottom plate, and the insulating layer covers a part of area in the first semiconductor layer;

the other partial area of the first semiconductor layer is provided with the plurality of grooves close to the surface of the bottom plate.

5. The laser assembly of claim 4, wherein the first electrode is attached to a surface area of the first semiconductor near the base plate and not covered by the insulating layer, the first semiconductor is a P-type semiconductor, and the first electrode is a P-electrode.

6. The laser assembly of claim 4, wherein heat generated by light emission from the active layer is transferred in the direction of the first semiconductor layer and the insulating layer.

7. The laser assembly of any of claims 2 to 6, wherein the plurality of trenches are formed by an etching process.

8. The laser assembly of any of claims 1 to 6, wherein the heat sink comprises: the heat dissipation substrate, the solder resist layer, the conducting layer and the solder layer are sequentially superposed along the direction far away from the bottom plate;

The solder layer is used for welding the light-emitting chip, and the conducting layer is used for being electrically connected with the light-emitting chip through the solder layer.

9. The laser assembly of claim 8, wherein the solder layer is soldered to the light emitting chip by heating, the solder layer being in contact with the first electrode.

10. The laser assembly of claim 8, wherein the heat sink substrate comprises a ceramic.

11. The laser assembly of claim 1, wherein the plurality of light emitting chips are arranged in an array.

12. The laser assembly of claim 11, wherein the heat sink corresponds to at least one of the light emitting chips.