Semiconductor laser, method for manufacturing semiconductor laser, and manufacturing apparatus for semiconductor laser

Abstract

The application discloses a semiconductor laser, a preparation method and a preparation device thereof. The semiconductor laser comprises a substrate and a plurality of laser chips. The plurality of laser chips are arranged on the same substrate. The plurality of laser chips are electrically connected to the substrate through at least one electrode transition structure. The cavity length directions of the plurality of laser chips are parallel to each other and parallel to the substrate. The fast axis directions of at least two laser chips are arranged at different angles with the substrate. The single-substrate multi-laser-chip integrated packaging is realized, and the single-direction packaging mode is avoided.

Description

Technical Field

[0001] This invention relates to the field of laser manufacturing, and more particularly to a semiconductor laser, a method for preparing a semiconductor laser, and an apparatus for preparing a semiconductor laser. Background Technology

[0002] Pump laser sources are core components of optoelectronic systems such as fiber lasers and fiber amplifiers, and are widely used in semiconductor fields such as optical communication and industrial processing. Pump lasers typically use semiconductor laser chips as light-emitting elements. The semiconductor laser chip is mounted on a substrate and coupled to an optical fiber to output pump light of a specific wavelength, thereby exciting the gain fiber.

[0003] In traditional pump laser modules, a single-chip, single-substrate packaging structure is typically used. A single semiconductor laser chip is mounted on a single substrate. After processes such as eutectic bonding and gold wire bonding, the single laser beam is coupled into a single optical fiber through an optical fiber and a lens to form an independent pump laser module.

[0004] However, with the continuous increase in the power of fiber lasers and the growing demand for multi-channel pumping, such as the need for multiple pump lights of different or the same wavelength to be injected into the gain fiber simultaneously, the limitations of traditional single-chip modules have become more apparent.

[0005] With low integration and large size, each additional pump light requires an additional complete module. When 2, 4 or even 8 pump light channels are needed, the entire system will be composed of multiple independent modules stacked or spliced ​​together, occupying a large space and hindering the integration, miniaturization and dense port arrangement of the equipment.

[0006] High power consumption and low efficiency mean that each independent module requires its own power supply, driver, and temperature control and heat dissipation components. When multiple modules work simultaneously, power consumption increases exponentially, and the independent heat dissipation paths between modules make it difficult to achieve global heat balance management, resulting in a decrease in the system's energy efficiency ratio.

[0007] The light output positions of multiple independent modules are scattered, making it difficult to centrally coil and protect multiple optical fibers, and the multi-path optical coupling alignment is complicated. Summary of the Invention

[0008] One of the objectives of this invention is to provide a semiconductor laser to solve the technical problem of the limitations of single substrate and single chip in the prior art.

[0009] One of the objectives of this invention is to provide a method for fabricating a semiconductor laser.

[0010] One of the objectives of this invention is to provide an apparatus for fabricating a semiconductor laser.

[0011] To achieve one of the above-mentioned objectives, one embodiment of the present invention provides a semiconductor laser, including a substrate and a plurality of laser chips. The plurality of laser chips are disposed on the same substrate, and the plurality of laser chips are electrically connected to the substrate through at least one electrode transition structure. The cavity length directions of the plurality of laser chips are parallel to each other and respectively parallel to the substrate, and the fast axis directions of at least two of the laser chips are arranged at different angles to the substrate.

[0012] As a further improvement of one embodiment of the present invention, the light-emitting points of the plurality of laser chips are distributed around a central point. The semiconductor laser includes an optical fiber bundle, the optical fiber bundle includes multiple optical fibers, the multiple optical fibers are arranged in a concentrated manner toward a central line, the central line is parallel to the cavity length direction and passes through the central point; the multiple optical fibers and the light-emitting points of the plurality of laser chips are arranged in a one-to-one correspondence, and the center of each optical fiber is aligned and coupled with the center of the light-emitting point.

[0013] As a further improvement of one embodiment of the present invention, the laser chip includes at least one first laser chip and at least one second laser chip, wherein the fast axis direction of the first laser chip is disposed perpendicular to the substrate, the fast axis direction of the second laser chip is disposed parallel to the substrate, and the second laser chip is located on the side of the first laser chip along its slow axis direction.

[0014] As a further improvement of one embodiment of the present invention, the electrode transition structure includes at least one first electrode transition structure, the first electrode transition structure being used to electrically connect the first laser chip and the substrate, and / or, the first electrode transition structure being used to electrically connect two adjacent first laser chips.

[0015] The semiconductor laser includes at least one thermally conductive insulating layer, at least one of the thermally conductive insulating layers is disposed on one side of the first laser chip, and the second laser chip is disposed on the side of the thermally conductive insulating layer opposite to the first laser chip.

[0016] As a further improvement of one embodiment of the present invention, the laser chip includes at least two first laser chips, the first electrode transition structure is located between two adjacent first laser chips, the thermally conductive insulating layer covers both sides of the first electrode transition structure, and extends from the first electrode transition structure along a direction parallel to the fast axis of the first laser chip toward the two first laser chips located at the ends, so as to at least cover portions of the two first laser chips located at the ends.

[0017] As a further improvement of one embodiment of the present invention, the electrode transition structure includes at least one second electrode transition structure, the second electrode transition structure being located on the side of the thermally conductive insulating layer away from the first laser chip and located between the thermally conductive insulating layer and the second laser chip, the thermally conductive insulating layer being insulatingly connected to the first electrode transition structure and the second electrode transition structure.

[0018] As a further improvement of one embodiment of the present invention, the semiconductor laser includes a first solder layer and a second solder layer. The first solder layer is located between the first laser chip and the substrate, which are closest to the substrate. The second solder layer is located between the second electrode transition structure and the substrate. The melting point of the first solder layer is higher than that of the second solder layer.

[0019] As a further improvement of one embodiment of the present invention, when multiple laser chips are electrically connected to the substrate through the same electrode transition structure, the same electrode transition structure is a third electrode transition structure; the third electrode transition structure is a polygonal columnar structure, the length direction of the third electrode transition structure is parallel to the cavity length direction of the laser chip, and the third electrode transition structure includes multiple side surfaces extending along the length direction; multiple laser chips are respectively disposed on multiple side surfaces of the same third electrode transition structure; one of the laser chips is disposed on the substrate.

[0020] As a further improvement of one embodiment of the present invention, the semiconductor laser includes multiple solder connection layers, and multiple laser chips are connected to the third electrode transition structure through multiple solder connection layers. The multiple solder connection layers are configured such that the multiple solder connection layers melt simultaneously at the same preset temperature.

[0021] As a further improvement of one embodiment of the present invention, a groove is provided on the surface of the substrate facing the laser chip, and the beam of the laser chip has an orthographic projection on the substrate along the fast axis direction. The orthographic projection is located in the groove and does not exceed the groove. The groove extends along the cavity length direction parallel to the laser chip. And / or, the electrode transition structure is provided with a groove facing the surface of the laser chip, the laser beam of the laser chip has an orthographic projection on the electrode transition structure along the fast axis direction, the orthographic projection is located in the groove and does not exceed the groove, and the groove extends along the cavity length direction parallel to the laser chip.

[0022] To achieve one of the above-mentioned objectives, one embodiment of the present invention provides a method for manufacturing a semiconductor laser, comprising the following steps: A substrate, multiple laser chips, and at least one electrode transition structure are provided; The plurality of laser chips are electrically connected to the substrate through at least one electrode transition structure; The cavity lengths of the plurality of laser chips are parallel to each other and parallel to the substrate, and the fast axis directions of at least two of the laser chips are set at different angles to the substrate.

[0023] As a further improvement of one embodiment of the present invention, the laser chip includes a first laser chip and a second laser chip, and the electrode transition structure includes a first electrode transition structure and a second electrode transition structure. The method for fabricating the semiconductor laser includes the following steps: The first laser chip is disposed on the substrate at an angle with its fast axis direction perpendicular to the substrate. The first electrode transition structure is disposed on the side of the first laser chip away from the substrate; A thermally conductive insulating layer is provided on at least one side of the combined structure formed by the first laser chip and the first electrode transition structure; The second laser chip and the second electrode transition structure are connected, and the combined structure formed by the second laser chip and the second electrode transition structure is set such that the fast axis direction of the second laser chip is parallel to the substrate. The second electrode transition structure is attached to the side of the thermally conductive insulating layer away from the first laser chip, and the second electrode transition structure is connected to the substrate. The second laser chip is located on the side of the second electrode transition structure away from the thermally conductive insulating layer.

[0024] As a further improvement to one embodiment of the present invention, the method includes the following steps: A first solder layer and a second solder layer are provided on the substrate. The first solder layer is heated, and the first laser chip is connected to the substrate through the molten first solder layer. After the first laser chip is connected to the substrate, a third solder layer is provided on the side of the first laser chip away from the substrate. When the third solder layer is heated, the first electrode transition structure is connected to the first laser chip through the molten third solder layer. The second laser chip or the second electrode transition structure is provided with a fourth solder layer. The fourth solder layer is heated, and the second laser chip is connected to the second electrode transition structure through the molten fourth solder layer. The second solder layer is heated, and the second electrode transition structure is connected to the substrate through the molten second solder layer.

[0025] As a further improvement of one embodiment of the present invention, the electrode transition structure includes a third electrode transition structure, which is a polygonal columnar structure and includes multiple side surfaces extending along its length direction. The multiple side surfaces are pre-set with solder connection layers. The multiple solder connection layers melt simultaneously at a preset temperature. The method for fabricating the semiconductor laser includes the following steps: The third electrode transition structure is placed on the heating platform of the semiconductor laser fabrication apparatus, and several laser chips are respectively fixed to multiple nozzles of the semiconductor laser fabrication apparatus; wherein, the length direction of the third electrode transition structure is perpendicular to the heating platform, the multiple laser chips correspond one-to-one with the multiple side surfaces, and the fast axis direction of each laser chip is perpendicular to the corresponding side surface. The system controls multiple suction nozzles to move simultaneously toward multiple sides, and controls the heating platform to heat to the preset temperature. Multiple laser chips are connected to multiple sides through the molten solder connection layer. A combined structure consisting of multiple laser chips and the third electrode transition structure is disposed on the substrate.

[0026] To achieve one of the above-mentioned objectives, an embodiment of the present invention provides a semiconductor laser fabrication apparatus, applicable to the semiconductor laser fabrication method in the above-mentioned technical solution, comprising a heating platform and a plurality of suction nozzles, wherein the plurality of suction nozzles are movably disposed relative to the heating platform.

[0027] Compared with the prior art, the present invention provides a semiconductor laser in which multiple laser chips are integrated and packaged on the same substrate, and at least two laser chips are arranged at different angles relative to the substrate along their fast axis. The multiple laser chips result in a higher concentration of emitted light beams, which enhances the luminous efficiency of the semiconductor laser per unit area. This avoids the stress concentration caused by unidirectional packaging and avoids the need for more installation space due to unidirectional packaging. It also improves the structural stability and packaging integration of the semiconductor laser, which is beneficial for the integration, miniaturization, and high efficiency of the semiconductor laser. The electrode transition structure is not only used to electrically connect the laser chips and the substrate, but also to fix the laser chips to the substrate, so that the fast axis directions of different laser chips can be arranged at different angles relative to the substrate. Attached Figure Description

[0028] Figure 1 , Figure 2 , Figure 3 This is a schematic diagram of the semiconductor laser at different angles in the first embodiment of the present invention.

[0029] Figure 4 , Figure 5 This is a schematic diagram of wire bonding of a semiconductor laser in the first embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of a semiconductor laser in the second embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram of a semiconductor laser in the third embodiment of the present invention.

[0032] Figure 8 This is a schematic diagram of a semiconductor laser with a heat dissipation path in the first embodiment of the present invention.

[0033] Figure 9 This is a schematic diagram of different combinations of upright and flip-chip mounting of multiple laser chips in the first embodiment of the present invention.

[0034] Figure 10 , Figure 11 , Figure 12 This is a schematic diagram of the semiconductor laser at different angles in the fourth embodiment of the present invention.

[0035] Figure 13 This is a schematic diagram of a semiconductor laser in the fifth embodiment of the present invention.

[0036] Figure 14 This is a schematic diagram of a semiconductor laser fabrication apparatus in one embodiment of the present invention. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.

[0038] It should be noted that the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Furthermore, the terms "first," "second," "third," "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] The terms “connection,” “connected to,” or any other variations are intended to encompass various relative positions where a connection exists, including both direct and indirect connections. A direct connection can be formed through a pneumatic conduit, while an indirect connection can be formed through devices such as valves or sensors, through pneumatic components such as brake control units, or through any other medium such as air.

[0040] Please see Figure 1 This is a schematic diagram of the structure of a semiconductor laser 1 provided in the first embodiment of the present invention. The semiconductor laser 1 is also called a pump laser.

[0041] The semiconductor laser 1 includes a substrate 10 and a plurality of laser chips 20. The plurality of laser chips 20 are disposed on the same substrate 10. The plurality of laser chips 20 are electrically connected to the substrate 10 through at least one electrode transition structure 30. The cavity length directions of the plurality of laser chips 20 are parallel to each other and parallel to the substrate 10. The fast axis directions of at least two laser chips 20 are set at different angles to the substrate 10.

[0042] In this way, multiple laser chips 20 can be integrated and packaged on the same substrate 10, and at least two laser chips 20 are set at different angles relative to the substrate 10 in the fast axis direction. The multiple laser chips 20 emit a high concentration of light beams, which enhances the luminous efficiency of the semiconductor laser 1 per unit area. This avoids the stress concentration caused by single-direction packaging and avoids single-direction packaging occupying more installation space. It also improves the structural stability and packaging integration of the semiconductor laser 1, which is beneficial to the integration, miniaturization and high efficiency of the semiconductor laser 1. The electrode transition structure 30 is not only used to electrically connect the laser chip 20 and the substrate 10, but also to fix the laser chip 20 to the substrate 10, so that the fast axis direction of different laser chips 20 can be set at different angles relative to the substrate 10.

[0043] The substrate 10 can be made of high thermal conductivity materials such as AlN or SiC. Several pads are disposed on the surface of the substrate 10. The pads are made of metallic material and are electrically insulated from each other. These pads are used to electrically connect to the positive or negative electrodes of different laser chips 20, or to the electrode transition structure 30. The electrodes of the laser chips 20 are electrically connected to the pads via solder and / or via wires, depending on actual requirements or spatial layout. Similarly, the electrode transition structure 30 is electrically connected to the pads via solder and / or via wires, depending on actual requirements or spatial layout.

[0044] The fact that multiple laser chips 20 are electrically connected to the substrate 10 through at least one electrode transition structure 30 means that multiple laser chips 20 are electrically connected to the same substrate 10 through different electrode transition structures 30, or that multiple laser chips 20 are electrically connected to the same substrate 10 through the same electrode transition structure 30.

[0045] refer to Figure 1 , Figure 6 , Figure 7These are the first, second, and third embodiments of the first type of implementation of this application. In the first type of implementation of this application, multiple laser chips 20 are sequentially disposed on the substrate 10. Specifically, multiple laser chips 20 are sequentially eutectic-attached to the substrate 10 through different electrode transition structures 30.

[0046] refer to Figure 10 , Figure 13 These are the fourth and fifth embodiments in the second type of implementation of this application. In the second type of implementation of this application, multiple laser chips 20 are simultaneously disposed on the substrate 10. Specifically, multiple laser chips 20 are simultaneously eutectic-attached to the same electrode transition structure 30 and then jointly disposed on the substrate 10.

[0047] The cavity length of each laser chip 20 corresponds to the length of its active region. The light-emitting point 201 of the laser chip 20 is located at one end of the laser chip 20 along its cavity length. The light-emitting point 201 is used to emit a light beam, and ideally, the beam propagates parallel to the cavity length. The fast axis of the laser chip 20 corresponds to the thickness of its active region, and the slow axis corresponds to the width of its active region. In practical applications, the light beam has a divergence angle along both the fast and slow axes of the laser chip 20.

[0048] In one specific embodiment, the plurality of laser chips 20 are all elongated strips, the cavity length direction of the laser chip 20 indicates the length direction of the laser chip, the fast axis direction of the laser chip 20 indicates the thickness direction of the laser chip, and the slow axis direction of the laser chip 20 indicates the width direction of the laser chip 20.

[0049] It is understood that, with the substrate 10 as a reference, the semiconductor laser 1 also defines a first direction and a second direction. The first direction is perpendicular to the substrate 10, also known as the vertical direction, and the second direction is parallel to the substrate 10, also known as the horizontal direction. In different embodiments, the cavity length direction of the laser chip 20 remains parallel to the first direction, but the fast axis direction of the laser chip 20 can be set to be parallel to either the first direction or the second direction.

[0050] Combination Figure 1 , Figure 6 , Figure 7 , Figure 10As shown, the semiconductor laser 1 integrates multiple laser chips 20. Each laser chip 20 includes at least one horizontally positioned laser chip and at least one vertically positioned laser chip. In a specific embodiment, the horizontally positioned laser chip 20 means that its cavity length direction is parallel to the substrate 10 and its fast axis direction is parallel to the substrate 10. The vertically positioned laser chip 20 means that its cavity length direction is parallel to the substrate 10 and its fast axis direction is perpendicular to the substrate 10. The horizontally positioned laser chip is located beside the vertically positioned laser chip, avoiding stacking along a single horizontal or vertical direction, reducing side packaging stress, and balancing the use of horizontal and vertical space.

[0051] Combination Figure 13 As shown, the fast axis direction of at least one laser chip 20 is perpendicular to the substrate 10, and the fast axis direction of at least another laser chip 20 is set at an acute angle to the substrate 10.

[0052] The laser chip 20 includes at least one first laser chip 20a and at least one second laser chip 20b. The fast axis of the first laser chip 20a is perpendicular to the substrate 10, and the fast axis of the second laser chip 20b is parallel to the substrate 10. The second laser chip 20b is located on the side of the first laser chip 20a along its slow axis to reduce lateral stress. The laser chip 20 is horizontally or vertically arranged relative to the substrate 10. The process is simple and easy to operate, and the overall structure is square, which can ensure a stable electrical connection.

[0053] It is understood that each laser chip 20 includes a positive electrode and a negative electrode, with the positive and negative electrodes located on opposite surfaces along the fast axis of their respective laser chips. When the first laser chip 20a is disposed perpendicular to the substrate 10, the surfaces of the first laser chip 20a where the positive and negative electrodes are disposed are parallel to the substrate 10. When the second laser chip 20b is disposed parallel to the substrate 10, the surfaces of the second laser chip 20b where the positive and negative electrodes are disposed are perpendicular to the substrate 10.

[0054] refer to Figure 1 , Figure 6 , Figure 7 As shown, at least one first laser chip 20a is vertically positioned in the fast axis direction, and at least one second laser chip 20b is horizontally positioned in the fast axis direction. The process is simple and makes balanced use of horizontal and vertical space.

[0055] Specifically, the first laser chip 20a and the second laser chip 20b are formed by sequentially mounting them together. The first laser chip 20a is mounted on the substrate 10 at an angle perpendicular to its fast axis direction; this is also called a vertical mounting. When there are multiple first laser chips 20a, they can be stacked vertically. The second laser chip 20b is rotated 90° so that it is positioned on the substrate 10 at an angle parallel to its fast axis direction; this is also called a horizontal mounting. It is understandable that if the angle of the fast axis direction of the laser chip 20 relative to the substrate 10 is unpredictable during sequential mounting, it will be inconvenient for process operation and will not be able to guarantee a stable electrical connection between multiple laser chips 20.

[0056] refer to Figure 10 As shown, the first laser chip 20a and the second laser chip 20b can also be formed simultaneously and in one piece. In this case, the arrangement direction of the multiple laser chips 20 depends on the shape of the electrode transition structure 30, which will be described in detail below.

[0057] The light-emitting points 201 of multiple laser chips 20 are distributed around a central point. The semiconductor laser 1 includes an optical fiber bundle 70, which includes multiple optical fibers 71. The multiple optical fibers 71 are arranged in a concentrated manner toward the central line, which is parallel to the cavity length direction and passes through the central point. The multiple optical fibers 71 and the light-emitting points 201 of the multiple laser chips 20 are arranged in a one-to-one correspondence. The center of each optical fiber 71 is aligned and coupled with the center of the light-emitting point 201. This is to couple a single laser beam from one laser chip 20 into the optical fiber bundle 70. Specifically, the optical fiber 71 and the light-emitting point 201 can be fixed by dispensing adhesive coupling.

[0058] In the above, multiple optical fibers 71 are coupled into an optical fiber bundle 70. The multiple optical fibers 71 are arranged in a concentrated manner towards the center line, which facilitates the integration of multiple optical fibers 71, and is beneficial for the overall coiling and protection of multiple optical fibers 71, avoiding cross-friction and movement of multiple optical fibers, and avoiding damage to optical fibers during testing, transportation and application.

[0059] The semiconductor laser 1 has a monolithic substrate 10 that integrates multiple laser chips 20, which are coupled with multiple optical fibers 71 to meet the growing demand for multi-channel pump lasers. For example, the semiconductor laser 1 requires multiple pump lasers of different or the same wavelength to be simultaneously injected into the gain fiber. The monolithic substrate 10 is independently powered, reducing power consumption and saving costs.

[0060] In one specific embodiment, the light-emitting points 201 of multiple laser chips are arranged to form a polygon, with the center point being the center of the polygon. Combined with... Figure 6 , Figure 7 , Figure 13As shown, the semiconductor laser 1 includes three laser chips 20, and the three light-emitting points 201 corresponding to the three laser chips 20 are arranged in a triangle. The center point of the triangle extends along the cavity length to form a center line, and multiple optical fibers 71 are concentrated near this center line, which is beneficial for the integration of multiple optical fibers 71 and the formation of an optical fiber bundle 70. Specifically, Figure 6 In the first laser chip 20a, the fast axis direction is perpendicular to the substrate 10, and the fast axis direction of the two second laser chips 20b is parallel to the substrate 10. The two second laser chips 20b are located on both sides of the first laser chip 20a. Figure 7 In the process, two first laser chips 20a are arranged along their fast axis direction, and a second laser chip 20b is located on one side of the first laser chip 20a. Figure 13 In the center, three laser chips are arranged in a circle.

[0061] Combination Figure 1 , Figure 10 As shown, the semiconductor laser 1 includes four laser chips 20. There are two first laser chips 20a and two second laser chips 20b. The four laser chips 20 are arranged in a quadrilateral shape, and the four light-emitting points corresponding to the four laser chips 20 are arranged in a rhombus shape. The structure is compact and symmetrical. The center point of the rhombus extends along the cavity length to form a center line, which is beneficial for the integration of multiple optical fibers, the centralized arrangement after coupling, and the protection of multiple optical fibers.

[0062] It is understood that in other embodiments, when the semiconductor laser 1 includes more laser chips 20, the light-emitting points of the multiple laser chips 20 can be arranged in a polygonal pattern to facilitate the formation of an optical fiber bundle, which is within the protection scope of this application.

[0063] In the above-mentioned first and second type of implementations, multiple light-emitting points 201 can be arranged in a polygonal pattern, which is beneficial to forming an optical fiber bundle 70 and to the centralized arrangement and integration of multiple optical fibers 71.

[0064] In other specific embodiments, for example, in the first type of embodiment of this application, combined with Figure 1 As shown, three or more first laser chips 20a are stacked sequentially, and three or more second laser chips 20b are stacked sequentially on both sides of the first laser chip 20a, so that all the laser chips 20 cannot form a regular polygon. It can be understood that all the laser chips can also be considered to be arranged roughly around a central point, so that the fiber bundle 70 can be concentrated towards the central line formed by the central point.

[0065] Similarly, in the second type of implementation of this application, combined with Figure 10 , Figure 13As shown, if more laser chips 20 are superimposed on a single laser chip 20 on any side, all the laser chips 20 cannot form a regular polygon. It can be understood that, at least, all the laser chips 20 can be considered to be arranged roughly around a central point, so that the fiber bundle 70 can be concentrated towards the central line formed by that central point.

[0066] The electrode transition structure 30 includes at least one first electrode transition structure 30a, which is used to electrically connect the first laser chip 20a and the substrate 10, and / or, the first electrode transition structure 30a is used to electrically connect two adjacent first laser chips 20a; it is understood that the number of first electrode transition structures 30a depends on the number of first laser chips 20a.

[0067] The semiconductor laser 1 includes at least one thermally conductive insulating layer 40, which is disposed on one side of a first laser chip 20a, and a second laser chip 20b is disposed on the side of the thermally conductive insulating layer 40 away from the first laser chip 20a. The thermally conductive insulating layer 40 is used to provide electrical insulation between the first laser chip 20a and the second laser chip 20b and to enhance the heat dissipation performance of the semiconductor laser 1.

[0068] The number of thermally conductive insulating layers 40 depends on the number of second laser chips 20b, combined with Figure 1 , Figure 6 As shown, when two second laser chips 20b are disposed on both sides of the first laser chip 20a, both second laser chips 20b need to be electrically insulated from the first laser chip 20a. Therefore, two thermally conductive insulating layers 40 are disposed on both sides of the first laser chip 20a, respectively located between the first laser chip 20a and the second laser chip 20b. When more second laser chips 20b are stacked, adjacent second laser chips 20b can also be electrically insulated by providing thermally conductive insulating layers 40.

[0069] Combination Figure 7 As shown, when a second laser chip 20b is disposed on one side of the first laser chip 20a, only a thermally conductive insulating layer 40 can be disposed to electrically insulate the second laser chip 20b and the first laser chip 20a.

[0070] The thermally conductive insulating layer 40 is a non-volatile adhesive with high thermal conductivity and insulating properties. Materials with high thermal conductivity such as AlN and SiC can be selected. The thermally conductive insulating layer 40 is coated and formed on the side of the combined structure of the first laser chip 20a and the first electrode transition structure 30a.

[0071] Combination Figure 6As shown, the semiconductor laser 1 includes a first laser chip 20a. A first electrode transition structure 30a is located on the side of the first laser chip 20a facing away from the substrate 10. The positive electrode of the first laser chip 20a is connected to the substrate 10, and the negative electrode is connected to the first electrode transition structure 30a. The first electrode transition structure 30a is then connected to the substrate 10 via a wire. Alternatively, the negative electrode of the first laser chip 20a is connected to the substrate 10, and the positive electrode is connected to the first electrode transition structure 30a. The first electrode transition structure 30a is then connected to the substrate 10 via a wire.

[0072] It is understood that in this application, the orientation of the positive and negative poles of any laser chip 20 does not affect its electrical connection, and the positive and negative poles can be connected to the substrate 10. Therefore, the specific connection method of the positive and negative poles of each laser chip 20 will not be described in detail.

[0073] The orientation of the positive and negative electrodes of each laser chip 20 is related to whether it is a flip-chip or a regular-chip. Specifically, when the positive electrode of the first laser chip 20a faces away from the substrate 10 and the negative electrode faces the substrate 10, its light-emitting point 201 is away from the substrate 10, and the first laser chip 20a is a regular-chip. When the positive electrode of the first laser chip 20a faces the substrate 10 and the negative electrode faces away from the substrate 10, its light-emitting point 201 is close to the substrate 10, and the first laser chip 20a is a flip-chip. In different embodiments, the orientation of the first laser chip 20a can be set according to actual needs.

[0074] Combination Figure 1 , Figure 7 As shown, the semiconductor laser 1 includes two first laser chips 20a, and a first electrode transition structure 30a is disposed between the two first laser chips 20a for electrically connecting the two first laser chips 20a or electrically connecting them to the substrate 10 respectively. Both first laser chips 20a can be optionally mounted upright or flip-chip. The first electrode transition structure 30a is not only used for the electrical connection of the first laser chips 20a, but also for fixing and supporting the first laser chip 20a located above it, so that the first laser chip 20a located above it can be fixed at an angle with its fast axis direction perpendicular to the substrate 10.

[0075] Combination Figure 1 , Figure 6 , Figure 7 As shown, after the first laser chip 20a and the first electrode transition structure 30a are attached, they are formed into a combined structure. A thermally conductive insulating layer 40 is provided on one or both sides of the combined structure of the first laser chip 20a and the first electrode transition structure 30a to increase the side heat dissipation path of the first laser chip 20a and the first electrode transition structure 30a and to electrically insulate the first laser chip 20a and the second laser chip 20b.

[0076] The electrode transition structure 30 includes at least one second electrode transition structure 30b. The second electrode transition structure 30b is located on the side of the thermally conductive insulating layer 40 away from the first laser chip 20a and between the thermally conductive insulating layer 40 and the second laser chip 20b. The thermally conductive insulating layer 40 provides an insulating connection between the first electrode transition structure 30a and the second electrode transition structure 30b, assisting in heat dissipation and improving thermal performance.

[0077] The second electrode transition structure 30b is used not only for the electrical connection of the second laser chip 20b, but also for the fixed connection of the second laser chip 20b, fixing it relative to the substrate 10, and keeping the fast axis direction of the second laser chip 20b parallel to the substrate 10. The thermally conductive insulating layer 40 insulatingly connects the first electrode transition structure 30a and the second electrode transition structure 30b, which is equivalent to electrically insulating the first laser chip 20a and the second laser chip 20b.

[0078] The laser chip 20 includes at least two first laser chips 20a. A first electrode transition structure 30a is located between two adjacent first laser chips 20a. A thermally conductive insulating layer 40 covers both sides of the first electrode transition structure 30a and extends from the first electrode transition structure 30a along a direction parallel to the fast axis of the first laser chip 20a toward the two first laser chips 20a located at the ends, so as to at least cover a portion of the two first laser chips 20a located at the ends; thereby enhancing the heat dissipation performance of the semiconductor laser 1.

[0079] The two first laser chips 20a located at the ends mean that, along the fast axis direction of the first laser chip 20a, the two first laser chips 20a located at the top and bottom respectively. It can be understood that the bottom first laser chip 20a is the first laser chip 20a closest to the substrate 10, while the top first laser chip 20a is the first laser chip 20a furthest from the substrate 10.

[0080] The thermally conductive insulating layer 40 is provided to cover the first laser chip 20a at the end, which is equivalent to covering all the first laser chips 20a and the first electrode transition structure 30a stacked along the direction parallel to the fast axis, thereby adding a side heat dissipation path for all the first laser chips 20a.

[0081] Combination Figure 1 , Figure 7 , Figure 8 As shown, Figure 8 The direction of the middle arrow indicates the heat dissipation path. The thermally conductive insulating layer 40 completely covers both sides of the first electrode transition structure 30a and covers the two adjacent first laser chips 20a respectively. It can guide some of the heat of the two first laser chips 20a to the side and then guide it towards the substrate 10 by the second electrode transition structure 30b, ensuring that the heat generated in the middle will not diffuse to the sides to the second laser chips 20b.

[0082] In this way, most of the heat from the first laser chip 20a in the middle diffuses downwards, and a small portion diffuses to both sides simultaneously. However, after diffusing to the sides, the heat is further guided to diffuse downwards, thus not affecting the second laser chip 20b on the side. Meanwhile, the heat from the second laser chip 20b diffuses downwards while simultaneously diffusing away from the first laser chip 20a. The heat diffusion paths of the first laser chip 20a and the second laser chip 20b do not affect each other.

[0083] The number of the second electrode transition structure 30b is related to the number of the second laser chip 20b, and is combined with Figure 3 As shown, the semiconductor laser 1 includes a second laser chip 20b and a second electrode transition structure 30b. After the second laser chip 20b and the second electrode transition structure 30b are connected, the second electrode transition structure 30b and the substrate 10 are then connected.

[0084] Combination Figure 1 , Figure 6 As shown, there are at least two second laser chips 20b and at least two second electrode transition structures 30b. The two second laser chips 20b are disposed on both sides of the first laser chip 20a and are electrically connected to the substrate 10 through the second electrode transition structures 30b, respectively. The second electrode transition structures 30b are connected to two thermally conductive insulating layers 40, forming downward and lateral heat dissipation paths.

[0085] Similar to the first laser chip 20a, the orientation of the positive and negative electrodes of the second laser chip 20b does not affect its electrical connection, and both can ensure that the positive and negative electrodes can be connected to the substrate 10. Therefore, the specific connection method of the positive and negative electrodes of the second laser chip 20b will not be described in detail.

[0086] The orientation of the positive and negative electrodes of the second laser chip 20b is related to whether it is a flip-chip or a regular-chip mount. Specifically, when the positive electrode of the second laser chip 20b faces away from the second electrode transition structure 30b and the negative electrode faces the second electrode transition structure 30b, its light-emitting point 201 is away from the second electrode transition structure 30b, and the second laser chip 20b is a regular-chip mount. When the positive electrode of the second laser chip 20b faces the second electrode transition structure 30b and the negative electrode faces away from the second electrode transition structure 30b, its light-emitting point 201 is close to the second electrode transition structure 30b, and the second laser chip 20b is a flip-chip mount. In different embodiments, the mounting method of the second laser chip 20b can be set according to actual needs.

[0087] The first laser chip 20a and the second laser chip 20b can be arbitrarily switched between upright and flip-chip mounting without affecting the electrical connection between them and the substrate 10, thus improving the flexibility of the semiconductor laser 1 layout. Figure 9As shown in the specific embodiment, when there are two of each of the first laser chip 20a and the second laser chip 20b, there are multiple patch combination methods between the first laser chip 20a and the second laser chip 20b.

[0088] The semiconductor laser 1 includes a first solder layer 61 and a second solder layer 62. The first solder layer 61 is located between the first laser chip 20a and the substrate 10, which are closest to the substrate. The second solder layer 62 is located between the second electrode transition structure 30b and the substrate 10. The melting point of the first solder layer 61 is higher than that of the second solder layer 62, which reduces the impact of high temperature on the first solder layer 61 and the first laser chip 20a that have been completed in the previous process during the sequential bonding process, thereby improving the reliability of the semiconductor laser 1.

[0089] Combination Figure 1 , Figure 6 , Figure 7 As shown, in the first embodiment of this application, the first laser chip 20a and the second laser chip 20b are sequentially eutectic-mounted onto the substrate 10. Specifically, the first laser chip 20a, which is closest to the substrate, is first mounted onto the substrate 10 via a first solder layer 61, and the second electrode transition structure 30b is mounted onto the substrate 10 via a second solder layer 62. If the melting point of the second solder layer 62 is greater than or equal to the melting point of the first solder layer 61, the first solder layer 61 will melt and diffuse during the mounting of the second electrode transition structure 30b onto the substrate 10, resulting in an unstable connection between the first laser chip 20a and the substrate 10.

[0090] It is understandable that, considering that the first laser chip 20a can be connected to the substrate 10 via the first solder layer 61 with either a positive or negative electrode, and the second laser chip 20b can be connected to the substrate 10 via the second solder layer 62 with either a positive or negative electrode, the first solder layer 61 and the second solder layer 62 can be connected as a whole or as spaced apart. When the first solder layer 61 and the second solder layer 62 correspond to the positive or negative electrode respectively, the first solder layer 61 and the second solder layer 62 are in a spaced apart form.

[0091] Combination Figure 1 As shown, in the first specific embodiment, the first laser chip 20a closest to the substrate is first attached to the substrate 10 via a first solder layer 61, and the first electrode transition structure 30 is attached to the first laser chip 20a via a third solder layer 63. It can be understood that more first laser chips 20a and first electrode transition structures 30 can be sequentially stacked and attached along the vertical direction. The second laser chip 20b and the second electrode transition structure 30b are first connected via a fourth solder layer 64, then rotated as a whole so that the fast axis direction of the second laser chip 20b is parallel to the substrate 10, and then the second electrode transition structure 30b is connected to the substrate 10 via a second solder layer 62.

[0092] Any of the above solder layers can be gold-tin, tin-silver-copper, silver-tin, bismuth-tin-silver, tin-copper, indium-silver, etc., and any solder layer can be a solder sheet or a pre-plated solder.

[0093] It is understandable that the multiple solder layers involved in the above process involve sequential preparation steps. By configuring the melting points of multiple solder layers, ensuring that the earlier prepared solder layers have higher melting points and the later prepared solder layers have lower melting points, the impact of multiple high-temperature processes during eutectic bonding on the solder layers already completed in the preceding processes can be reduced. Combined with... Figure 1 As shown, specifically, the melting points of the first solder layer 61, the third solder layer 63, and the second solder layer 62 decrease sequentially, and the melting point of the fourth solder layer 64 is higher than that of the second solder layer 62.

[0094] In other embodiments, considering the complexity of configuring different solder layers with multiple melting points, it is also possible to optionally configure at least the first solder layer 61 and the third solder layer 63 to have the same melting point, ensuring that the process parameter settings between the first laser chip 20a and the first electrode transition structure 30a are completely identical. Alternatively, in different application scenarios, considering the complexity of adjusting process parameters, it is also possible to optionally configure all the first solder layer 61, the second solder layer 62, the third solder layer 63, and the fourth solder layer 64 to be identical. In this way, the same placement temperature is set during the mounting process of the same semiconductor laser 1, without the need for repeated temperature adjustments.

[0095] A groove 11 is provided on the surface of the substrate 10 facing the laser chip 20. The beam of the laser chip 20 has an orthographic projection on the substrate 10 along the fast axis direction. The orthographic projection is located in the groove 11 and does not exceed the groove 11. The groove 11 extends along the cavity length direction parallel to the laser chip 20. The groove 11 is used to avoid the beam and prevent interference with the normal light emission of the first laser chip 20a on its upper side. The groove 11 is also used to avoid the coupling between the optical fiber 71 and the light emission point 201.

[0096] Combination Figure 1 , Figure 2 , Figure 3 As shown, in one embodiment, the laser chip 20 includes a first laser chip 20a located on the bottom side closest to the substrate. The emitting surface of the first laser chip 20a, whose light-emitting point 201 is located, is aligned with the side of the groove 11, and the bottom surface of the groove 11 extends along the cavity length. The light-emitting point 201 of the first laser chip 20a is positioned close to the positive electrode. When the first laser chip 20a is a flip-chip, the light-emitting point 201 is close to the substrate 10, and the beam typically has a divergence angle. The groove 11 is used to avoid the beam and not block the light emission path. When the light-emitting point 201 is used to couple the optical fiber 71, if the surface distance between the light-emitting point 201 and the substrate 10 is too small, it is not conducive to the coupling of the optical fiber 71.

[0097] It is understandable that the distance between the light-emitting point 201 of the second laser chip 20b and the first laser chip 20a which is biased towards the upper side of the substrate and the substrate 10 is relatively large. Therefore, the substrate 10 will not block its light emission or affect its fiber coupling.

[0098] The electrode transition structure 30 has a groove 11 on its surface facing the laser chip 20. The beam of the laser chip 20 has an orthographic projection on the electrode transition structure 30 along the fast axis direction. The orthographic projection is located in the groove 11 and does not exceed the groove 11. The groove 11 extends along the cavity length direction parallel to the laser chip 20. Similarly, the groove 11 is used to avoid the light and to avoid the coupling between the optical fiber 71 and the light-emitting point 201.

[0099] In one embodiment, when the first laser chip 20a closest to the substrate 10 is mounted upright, its light-emitting point 201 is close to the first electrode transition structure 30a above it. The surface distance between the light-emitting point 201 and the first electrode transition structure 30a is too small, which will block the light-emitting path and is not conducive to the coupling of the optical fiber 71. Setting the light beam of the first laser chip 20a closest to the substrate 10 can diverge into the groove 11 to avoid the light-emitting path and provide coupling space with the optical fiber 71.

[0100] Understandably, in combination Figure 2 As shown, in order to adapt to any mounting method of the first laser chip 20a, grooves 11 can be simultaneously fabricated on both the substrate 10 and the first electrode transition structure 30a to provide redundant clearance space.

[0101] It is understandable that, in order to accommodate any mounting method of the second laser chip 20b, the surface of the second electrode transition structure 30b facing the second laser chip 20b may also be selectively provided with a groove 11 to provide clearance space for the second laser chip 20b.

[0102] The above is a detailed description of different embodiments in the first type of implementation of this application. The following will elaborate on the distinguishing features of the second type of implementation of this application from the first type of implementation.

[0103] It should be emphasized that the common features of the first type of implementation and the second type of implementation are at least as follows: the fast axis direction of at least two laser chips 20 is set at an angle to the substrate 10 to avoid a single-direction packaging method; and the light-emitting points 201 of the multiple laser chips 20 are arranged in a polygonal shape to facilitate the formation of an optical fiber bundle.

[0104] The difference between the first and second implementation methods lies at least in the different electrical connection methods between the laser chip 20 and the electrode transition structure 30 due to the different mounting methods. Specifically, in the first implementation method, due to sequential mounting, different laser chips 20 need to be electrically connected to the substrate 10 via different electrode transition structures 30. In the second implementation method, due to simultaneous mounting in one step, different laser chips 20 can be electrically connected to the same electrode transition structure 30 before being mounted to the substrate 10.

[0105] When multiple laser chips 20 are electrically connected to the substrate 10 through the same electrode transition structure 30, the same electrode transition structure 30 is a third electrode transition structure 30c; the third electrode transition structure 30c is a polygonal columnar structure, the length direction of the third electrode transition structure 30c is parallel to the cavity length direction of the laser chip 20, and the third electrode transition structure 30c includes multiple side surfaces 301 extending along its length direction; multiple laser chips 20 are disposed on multiple side surfaces 301 of the same third electrode transition structure 30c; one of the laser chips 20 is disposed on the substrate 10; the process is simple and the mounting efficiency is high.

[0106] Combination Figure 10 As shown, the third electrode transition structure 30c is a square pillar with four sides 301 and two end faces, and four laser chips 20 are respectively attached to the four sides 301. Combined with... Figure 13 As shown, the third electrode transition structure 30c is a triangular prism with three sides 301 and two end faces, and the three laser chips 20 are respectively attached to the three sides 301. It can be understood that when a larger number of laser chips 20 need to be integrated, a polygonal prism structure with a corresponding number of sides 301 can be provided, so that multiple laser chips 20 can be attached to the corresponding sides 301 one by one.

[0107] The third electrode transition structure 30c is used not only to electrically connect the laser chip 20 to the substrate 10, but also to fix and support the laser chip 20, so that multiple laser chips 20 are fixed at different angles relative to the substrate 10. For example, when three laser chips 20 are fixed to the triangular prism-shaped third electrode transition structure 30c, the fast axis direction of the two upper laser chips 20 forms an acute angle with the substrate 10. For example, when four laser chips 20 are fixed to the square prism-shaped third electrode transition structure 30c, the fast axis direction of two laser chips 20 is parallel to the substrate, while the fast axis direction of the other two laser chips is perpendicular to the substrate 10.

[0108] It is understood that the second type of implementation of this application can also be extended to a combination of one-time application and sequential application, for example, in Figure 10 Based on this, more laser chips 20 are sequentially attached to the existing laser chip 20 in either a horizontal or vertical direction.

[0109] A groove 11 is provided on the surface of the substrate 10 facing the laser chip 20. The beam of the laser chip 20 has an orthographic projection on the substrate 10 along the fast axis direction. The orthographic projection is located in the groove 11 and does not exceed the groove 11. The groove 11 extends along the cavity length direction parallel to the laser chip 20. And / or, the electrode transition structure 30 has a groove on its surface facing the laser chip 20, and the laser beam of the laser chip has an orthographic projection on the electrode transition structure 30 along the fast axis direction. The orthographic projection is located within the groove 11 and does not extend beyond the groove 11. The groove 11 extends along the cavity length direction parallel to the laser chip 20; it is used to avoid light and fiber coupling. It is understood that the specific arrangement and structure of the groove 11 are the same as in the first type of embodiment.

[0110] Combination Figure 10 , Figure 13 As shown, in the second embodiment of this application, the electrode transition structure is a third electrode transition structure 30c, and a groove 11 is provided on the top surface of the substrate 10 and / or the bottom side surface of the third electrode transition structure 30c. Combined with... Figure 11 , Figure 12 As shown, a groove 11 is provided on the top surface of the substrate 10 or the bottom side surface of the third electrode transition structure 30c, depending on whether it is a flip-chip or a standard-mount chip. Alternatively, the substrate 10 and the third electrode transition structure 30c may both be provided with grooves 11 to increase the redundant clearance space.

[0111] Alternatively, grooves 11 can be selectively combined on multiple sides of the third electrode transition structure 30c to avoid the emission of multiple laser chips 20 and fiber coupling.

[0112] The number of laser chips 20 is equal to the number of sides 301 of the third electrode transition structure 30c. In a preferred embodiment, multiple laser chips 20 are used to simultaneously attach to multiple sides 301 of the third electrode transition structure 30c, thereby improving the utilization rate of the third electrode transition structure 30c. For example, three laser chips 20 are attached to a triangular prism, and four laser chips 20 are attached to a square prism.

[0113] The semiconductor laser 1 includes multiple solder connection layers 65. Multiple laser chips 20 are connected to a third electrode transition structure 30c through the multiple solder connection layers 65. The multiple solder connection layers 65 are configured to melt simultaneously at the same preset temperature. It is understood that for multiple laser chips 20 to be simultaneously attached to the third electrode transition structure 30c, it is necessary to ensure that the multiple solder connection layers 65 are within the same melting temperature window. If the melting point of one of the solder connection layers 65 is too low or too high, premature melting or insufficient melting will lead to mounting failure or unstable electrical connections after mounting.

[0114] Multiple solder connection layers 65 preferably use the same structural composition to ensure that the melting points of the multiple solder connection layers 65 are consistent, so that the multiple solder connection layers 65 melt simultaneously at the same preset temperature. The solder connection layer 65 can be gold-tin, tin-silver-copper, silver-tin, bismuth-tin-silver, tin-copper, indium-silver, etc. The solder connection layer 65 can be a solder sheet or a pre-plated solder.

[0115] After multiple laser chips 20 are connected to the same third electrode transition structure 30c, one of the laser chips 20 is then attached to the substrate 10, which is equivalent to placing all the laser chips 20 and the third electrode transition structure 30c on the substrate 10.

[0116] This application also protects a method for fabricating a semiconductor laser 1, applicable to the fabrication of the semiconductor laser 1 described above. The fabrication method includes the following steps: S1: Provides a substrate 10, a plurality of laser chips 20 and at least one electrode transition structure 30; S2: Connect multiple laser chips 20 to the substrate 10 through at least one electrode transition structure 30; In this configuration, the cavity length directions of multiple laser chips 20 are parallel to each other and parallel to the substrate 10, and the fast axis directions of at least two laser chips 20 are set at different angles to the substrate 10, thereby avoiding a single-direction packaging method, reducing packaging stress, and improving space utilization.

[0117] Connecting multiple laser chips 20 to the substrate 10 via at least one electrode transition structure 30 means that the multiple laser chips 20 are sequentially connected to the same substrate 10 via different electrode transition structures 30, or that the multiple laser chips 20 are simultaneously connected to the same electrode transition structure 30.

[0118] Understandably, in combination Figure 1 , Figure 6 , Figure 7 As shown, multiple laser chips 20 are sequentially electrically connected to the same substrate 10 through different electrode transition structures 30. This is the first type of embodiment of this application, and can also be simply referred to as sequential patching; combined with Figure 10 , Figure 13 As shown, multiple laser chips 20 are simultaneously electrically connected to the same electrode transition structure 30, and then the multiple laser chips 20 and the same electrode transition structure 30 are electrically connected to the substrate 10. This is the second type of implementation of this application, which can also be simply referred to as simultaneous, one-time surface mounting. As mentioned above, in different types of implementations, at least two laser chips 20 can be mounted perpendicularly to each other or at an angle in the fast axis direction, in short, surface mounting and packaging in different directions can be achieved.

[0119] Laser chip 20 includes a first laser chip 20a and a second laser chip 20b; electrode transition structure 30 includes a first electrode transition structure 30a and a second electrode transition structure 30b; the fabrication method of semiconductor laser 1 includes the following steps: The first laser chip 20a is disposed on the substrate 10 at an angle with its fast axis direction perpendicular to the substrate 10; The first electrode transition structure 30a is disposed on the side of the first laser chip 20a away from the substrate 10; A thermally conductive insulating layer 40 is provided on at least one side of the combined structure formed by the first laser chip 20a and the first electrode transition structure 30a; The second laser chip 20b and the second electrode transition structure 30b are connected, and the combined structure formed by the second laser chip 20b and the second electrode transition structure 30b is set to an angle in which the fast axis direction of the second laser chip is parallel to the substrate. The second electrode transition structure 30b is attached to the side of the thermally conductive insulating layer 40 away from the first laser chip, and the second electrode transition structure 30b is connected to the substrate 10. The second laser chip 20b is located on the side of the second electrode transition structure 30b away from the thermally conductive insulating layer 40. This achieves the sequential mounting of the first laser chip 20a and the second laser chip 20b, with the fast axis directions of the first laser chip 20a and the second laser chip 20b at different angles to the substrate 10. Specifically, combined with... Figure 6 As shown, when there is only one first laser chip 20a, one first laser chip 20a is disposed on the substrate 10, and then the first electrode transition structure 30a is disposed on the first laser chip.

[0120] Combination Figure 1 , Figure 7 As shown, when there are two first laser chips 20a, one of the first laser chips 20a is sequentially placed on the substrate 10, the first electrode transition structure 30a is placed on the attached first laser chip 20a, and finally the other first laser chip 20a is placed on the first electrode transition structure 30a.

[0121] It is understood that in other embodiments, when the semiconductor laser 1 needs to be provided with a larger number of first laser chips 20a and first electrode transition structures 30a, the first laser chips 20a and first electrode transition structures 30a can be alternately provided in sequence according to the above steps.

[0122] The thermally conductive insulating layer 40 is a thermally conductive insulating adhesive. The thermally conductive insulating adhesive is applied to the side of the already completed combination structure of the first laser chip 20a and the first electrode transition structure 30a. The thermally conductive insulating layer 40 should cover the side of the first electrode transition structure 30a, or cover the side of multiple first electrode transition structures 30a at the same time, to ensure the heat dissipation of the overall structure and the insulation between it and the subsequently mounted second laser chip 20b.

[0123] Combination Figure 1 , Figure 6 , Figure 7 As shown, in the actual process, on a horizontal worktable, the fast axis direction of the second laser chip 20b is perpendicular to the worktable, and the second laser chip 20b is connected to the second laser chip 20b as a whole through the fourth solder layer 64 and the second electrode transition structure 30b.

[0124] Then, the combined structure of the second laser chip 20b and the second electrode transition structure 30b is rotated 90° so that the fast axis of the second laser chip 20b is parallel to the worktable. The combined structure of the second laser chip 20b is then connected to the substrate 10 via the second solder layer 62. It is worth noting that the second electrode transition structure 30b is also bonded to the thermally conductive insulating layer 40.

[0125] When there is one second laser chip 20b, there is also one second electrode transition structure 30b. The two are combined and disposed on one side of the first laser chip 20a. When there are two second laser chips 20b, there are also two second electrode transition structures 30b. The two are combined and disposed on both sides of the first laser chip 20a.

[0126] It is understood that in more embodiments, when the semiconductor laser 1 needs to be provided with a larger number of second laser chips 20b, the second electrode transition structure 30b and the second laser chips 20b can be stacked and arranged outward along the slow axis direction of the first laser chip.

[0127] The method for fabricating a semiconductor laser 1 includes the following steps: a first solder layer 61 and a second solder layer 62 are disposed on a substrate 10; the first solder layer 61 is heated; and a first laser chip 20a is connected to the substrate 10 through the molten first solder layer 61. After the first laser chip 20a is connected to the substrate 10, a third solder layer 63 is provided on the side of the first laser chip 20a away from the substrate 10. When the third solder layer 63 is heated, the first electrode transition structure 30a is connected to the first laser chip 20a through the molten third solder layer 63. The second laser chip 20b or the second electrode transition structure 30b is provided with a fourth solder layer 64. The fourth solder layer 64 is heated, and the second laser chip 20b is connected to the second electrode transition structure 30b through the molten fourth solder layer 64. The second solder layer 62 is heated, and the second electrode transition structure 30b is connected to the substrate 10 through the molten second solder layer 62. In this application, the substrate 10, the first laser chip 20a and the first electrode transition structure 30a are eutectic bonded, the second laser chip 20b and the second electrode transition structure 30b are eutectic bonded, and the second electrode transition structure 30b and the substrate 10 are also eutectic bonded. It can be understood that the eutectic bonded connection is used to achieve electrical connection.

[0128] Specifically, the first solder layer 61 and the second solder layer 62 are both pre-formed on the substrate 10. The substrate 10 is usually placed on a heating platform, and the first laser chip 20a is placed on the first solder layer 61. When heated to the eutectic temperature required for the first solder layer 61, the first solder layer 61 melts, and the first laser chip 20a and the substrate 10 are connected.

[0129] It is understandable that the melting point of the first solder layer 61 is higher than that of the second solder layer 62 here, so as to ensure that when the second solder layer 62 melts at high temperature later, it will not cause the first solder layer 61 to melt and affect the connection between the first laser chip 20a and the substrate 10.

[0130] The first laser chip 20a, closest to the substrate 10, has a third solder layer 63 pre-formed on the side facing away from the substrate 10. The first electrode transition structure 30a is placed on the third solder layer 63 and heated to the eutectic temperature of the third solder layer 63, causing the third solder layer 63 to melt. The first electrode transition structure 30a then connects to the first laser chip 20a. The first solder layer 61 and the third solder layer 63 may have the same melting point, or the melting point of the first solder layer 61 may be higher than that of the third solder layer 63.

[0131] The second laser chip 20b or the second electrode transition structure 30b is separately pre-set with a fourth solder layer 64. The one located below and close to the heating platform is used to set the fourth solder layer 64. The fourth solder layer 64 is then heated to connect with the second electrode transition structure 30b. The above can be a separate high-temperature eutectic bonding process, which does not affect the connection between the already completed substrate 10, the first laser chip 20a and the first electrode transition structure 30a.

[0132] When the combined structure formed by the second laser chip 20b and the second electrode transition structure 30b is connected to the substrate 10 through the second solder layer 62, the second solder layer 62 needs to be melted at a high temperature. It is understood that at this time, the first laser chip 20a and the first electrode transition structure 30a have already been connected to the substrate 10. Optionally, the melting point of the second solder layer 62 is lower than that of the first solder layer 61, the third solder layer 63, and the fourth solder layer 64, ensuring that the high-temperature eutectic temperature of the subsequent bonding layer does not cause the solder layer of the preceding bonding layer to melt.

[0133] In other application scenarios, considering the priority of ensuring consistent process parameters, the melting points of the first solder layer 61, the second solder layer 62, the third solder layer 63, and the fourth solder layer 64 can also be selected to be consistent.

[0134] Understandably, both the positive and negative electrodes of the laser chip 20 need to be connected to the substrate 10. Besides electrical connection via eutectic bonding, wire bonding is also required. Either laser chip 20 can be mounted as a surface mount or flip-chip without affecting its electrical connection. Figure 1 , Figure 4 , Figure 5 As shown, this application provides a detailed connection method of eutectic patch combined with wire bonding in the first embodiment. Other embodiments will not be described in detail.

[0135] The positive electrode of the lower first laser chip 20a is eutectic bonded to the substrate 10 through the first solder layer 61. The negative electrode of the lower first laser chip 20a is connected to the first electrode transition structure 30a through a eutectic bond, and the first electrode transition structure 30a is wire-bonded to the substrate 10. The negative electrode of the upper first laser chip 20a is connected to the first electrode transition structure 30a through a eutectic bond, and the positive electrode of the upper first laser chip 20a is electrically connected to the pad of the substrate 10 through wire bonding. Thus, the positive and negative electrodes of both first laser chips 20a are connected to the substrate 10.

[0136] The negative electrode of any second laser chip 20b and the second electrode transition structure 30b are eutectic bonded together. The second electrode transition structure 30b is eutectic bonded to the substrate 10 through the second solder layer 62. The positive electrode of the second laser chip 20b is electrically connected to the substrate 10 through wire bonding. The positive and negative electrodes of the two second laser chips 20b on both sides can be connected to the substrate 10 in the above manner.

[0137] It is understood that in more embodiments, when the semiconductor laser 1 needs to be provided with a larger number of first and second laser chips 20b, the electrical connection with the substrate 10 can be achieved through eutectic bonding and wire bonding with the first and second electrode transition structures 30.

[0138] The above describes the specific fabrication steps of the semiconductor laser 1 in the first embodiment of this application.

[0139] The following describes the specific fabrication steps of the semiconductor laser 1 in the second embodiment of this application.

[0140] When multiple laser chips 20 are simultaneously electrically connected to the same electrode transition structure 30, the same electrode transition structure 30 is a third electrode transition structure 30c. The third electrode transition structure 30c is a polygonal columnar structure and includes multiple side surfaces 301 extending along its length direction. The multiple side surfaces 301 are pre-set with solder connection layers 65. The multiple solder connection layers 65 melt simultaneously at a preset temperature. The method for fabricating semiconductor laser 1 includes the following steps: The third electrode transition structure 30c is placed on the heating platform 100 of the semiconductor laser fabrication apparatus 1000, and several laser chips 20 are respectively fixed to multiple nozzles 200 of the semiconductor laser fabrication apparatus; wherein, the length direction of the third electrode transition structure 30c is perpendicular to the heating platform 100, and the multiple laser chips 20 correspond one-to-one with multiple side surfaces 301, and the fast axis direction of each laser chip 20 is perpendicular to the corresponding side surface 301; it can be understood that the steps of placing the third electrode transition structure 30c and fixing the laser chips 20 are not distinguished by their order. Multiple suction nozzles 200 are controlled to move simultaneously toward multiple sides 301, and the heating platform 100 is controlled to heat to a preset temperature. Multiple laser chips 20 are connected to multiple sides 301 through a molten solder bonding layer 65. It is understood that the steps of controlling the movement of the suction nozzles 200 and controlling the heating platform 100 to heat are not distinguished by their order. Specifically, the suction nozzles 200 can be controlled to move to the side 301, and the laser chips 20 can be brought into contact with the solder bonding layer 65 before the heating action is performed; alternatively, the laser chips 20 can be heated to a preset temperature before they come into contact with the solder bonding layer 65. Multiple laser chips 20 and a third electrode transition structure 30c are disposed on a substrate 10; the semi-finished product is further attached to the substrate 10 along one direction to form the overall structure of the semiconductor laser 1. Specifically, one of the laser chips 20 is further connected to the substrate 10 through a solder layer.

[0141] Combination Figure 14 As shown, in the second embodiment of this application, a semiconductor laser fabrication apparatus 1000 is disclosed, applied to the fabrication method of the semiconductor laser 1 according to the above-described technical solution. The fabrication apparatus 1000 includes a heating platform 100 and a plurality of suction nozzles 200, which are movably disposed relative to the heating platform 100. Each of the plurality of suction nozzles 200 includes a vacuum channel for vacuum adsorption of laser chips 20. Thus, the plurality of suction nozzles 200 can simultaneously adsorb multiple laser chips 20, thereby driving the laser chips 20 and the third electrode transition structure 30c to complete the bonding process.

[0142] Specifically, the fabrication apparatus 1000 includes a horizontal heating platform 100 and four suction nozzles 200, which are arranged in pairs facing each other in a quadrilateral configuration. The third electrode transition structure 30c is a square pillar, which is placed vertically on the heating platform 100. The four sides 301 of the square pillar face the four suction nozzles 200 respectively. The four suction nozzles 200 can reach the corresponding sides 301 by moving in a straight line, and the four laser chips 20 and the solder connection layer 65 come into contact. The heating platform 100 is then heated to a preset temperature to melt the solder connection layer 65, thereby achieving the connection between the four laser chips 20 and the solder connection layer 65.

[0143] The beneficial effects of the present invention are as follows: multiple laser chips 20 are integrated and packaged on the same substrate 10, and at least two laser chips 20 are arranged at different angles relative to the substrate 10 in the fast axis direction. The multiple laser chips 20 emit a high concentration of light beams, which enhances the luminous efficiency of the semiconductor laser 1 per unit area. It avoids the stress concentration caused by the single-direction packaging method, avoids the single-direction packaging occupying more installation space, improves the structural stability and packaging integration of the semiconductor laser 1, and is conducive to the integration, miniaturization and high efficiency of the semiconductor laser 1. The electrode transition structure 30 is not only used to electrically connect the laser chip 20 and the substrate 10, but also to fix the laser chip 20 to the substrate 10, so that the fast axis direction of different laser chips 20 can be arranged at different angles relative to the substrate 10. The light-emitting points 201 of multiple laser chips 20 are distributed around a central point, and the multiple optical fibers 71 are coupled and arranged towards the central line, which facilitates the integration of multiple optical fibers 71, the formation of optical fiber bundles 70 and the protection of optical fibers; multiple laser chips 20 are coupled with multiple optical fibers 71 to meet the growing demand for multi-channel pump lasers.

[0144] This can be formed by referring to any of the technical solutions provided above, and will not be elaborated here.

[0145] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0146] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A semiconductor laser, comprising a substrate and a plurality of laser chips, wherein the plurality of laser chips are disposed on the same substrate, characterized in that, The plurality of laser chips are electrically connected to the substrate through at least one electrode transition structure. The cavity length directions of the plurality of laser chips are parallel to each other and respectively parallel to the substrate. The fast axis directions of at least two of the laser chips are set at different angles to the substrate. The laser chip includes at least one first laser chip and at least one second laser chip. The fast axis direction of the first laser chip is perpendicular to the substrate, and the fast axis direction of the second laser chip is parallel to the substrate. The second laser chip is located on the side of the first laser chip along its slow axis direction. The electrode transition structure includes at least one first electrode transition structure, which is used to electrically connect the first laser chip and the substrate, and / or, the first electrode transition structure is used to electrically connect two adjacent first laser chips. The electrode transition structure includes at least one second electrode transition structure, which is used to electrically connect the second laser chip and the substrate. The second electrode transition structure is located between the first laser chip and the second laser chip and is located on the common side of the first laser chip and the first electrode transition structure.

2. The semiconductor laser according to claim 1, characterized in that, The light-emitting points of multiple laser chips are distributed around a central point. The semiconductor laser also includes an optical fiber bundle, which includes multiple optical fibers. The multiple optical fibers are arranged in a concentrated manner toward a central line, which is parallel to the cavity length direction and passes through the central point. The multiple optical fibers and the multiple light-emitting points of the laser chips are arranged in a one-to-one correspondence, and the center of each optical fiber is aligned and coupled with the center of the light-emitting point.

3. The semiconductor laser according to claim 2, characterized in that, The light-emitting points of multiple laser chips are arranged to form a polygon, and the center point is the center of the polygon.

4. The semiconductor laser according to claim 1, characterized in that, The semiconductor laser includes at least one thermally conductive insulating layer, at least one of the thermally conductive insulating layers is disposed on one side of the first laser chip, and the second laser chip is disposed on the side of the thermally conductive insulating layer opposite to the first laser chip; The second electrode transition structure is located on the side of the thermally conductive insulating layer away from the first laser chip and between the thermally conductive insulating layer and the second laser chip. The thermally conductive insulating layer provides an insulating connection between the first electrode transition structure and the second electrode transition structure.

5. The semiconductor laser according to claim 4, characterized in that, The laser chip includes at least two first laser chips, the first electrode transition structure is located between two adjacent first laser chips, the thermally conductive insulating layer covers both sides of the first electrode transition structure, and extends from the first electrode transition structure along a direction parallel to the fast axis of the first laser chip toward the two first laser chips located at the ends, so as to at least cover portions of the two first laser chips located at the ends.

6. The semiconductor laser according to claim 1, characterized in that, The semiconductor laser includes a first solder layer and a second solder layer. The first solder layer is located between the first laser chip and the substrate, which are closest to the substrate. The second solder layer is located between the second electrode transition structure and the substrate. The melting point of the first solder layer is higher than that of the second solder layer.

7. The semiconductor laser according to claim 1, characterized in that, The substrate has a groove on its surface facing the laser chip. The laser beam of the laser chip has an orthographic projection on the substrate along its fast axis. The orthographic projection is located within the groove and does not extend beyond the groove. The groove extends along a direction parallel to the cavity length of the laser chip. And / or, the electrode transition structure is provided with a groove facing the surface of the laser chip, the laser beam of the laser chip has an orthographic projection on the electrode transition structure along its fast axis direction, the orthographic projection is located in the groove and does not extend beyond the groove, and the groove extends along a direction parallel to the cavity length of the laser chip.

8. A method for fabricating a semiconductor laser, characterized in that, Including the following steps: A substrate, multiple laser chips, and at least one electrode transition structure are provided; The plurality of laser chips are electrically connected to the substrate through at least one of the electrode transition structures; The cavity length directions of the plurality of laser chips are parallel to each other and respectively parallel to the substrate, and the fast axis directions of at least two of the laser chips are set at different angles to the substrate; The laser chip includes a first laser chip and a second laser chip, and the electrode transition structure includes a first electrode transition structure and a second electrode transition structure. The method for fabricating the semiconductor laser includes the step of: placing the first laser chip on the substrate at an angle where its fast axis direction is perpendicular to the substrate; The first electrode transition structure is disposed on the side of the first laser chip facing away from the substrate; the first laser chip and the first electrode transition structure form a combined structure; The second laser chip and the second electrode transition structure are connected, and the combined structure formed by the second laser chip and the second electrode transition structure is set such that the fast axis direction of the second laser chip is parallel to the substrate. The combined structure formed by the second laser chip and the second electrode transition structure is attached to the side of the combined structure formed by the first laser chip and the first electrode transition structure, and the second electrode transition structure is connected to the substrate.

9. The method for fabricating a semiconductor laser according to claim 8, characterized in that, The steps of placing the first electrode transition structure on the side of the first laser chip away from the substrate include: A thermally conductive insulating layer is provided on at least one side of the combined structure formed by the first laser chip and the first electrode transition structure; After the second laser chip and the second electrode transition structure are connected to form a combined structure, the following steps are included: The second electrode transition structure is attached to the side of the thermally conductive insulating layer away from the first laser chip, and the second laser chip is located on the side of the second electrode transition structure away from the thermally conductive insulating layer.

10. The method for fabricating a semiconductor laser according to claim 8, characterized in that, Including the following steps: A first solder layer and a second solder layer are provided on the substrate. The first solder layer is heated, and the first laser chip is connected to the substrate through the molten first solder layer. After the first laser chip is connected to the substrate, a third solder layer is provided on the side of the first laser chip away from the substrate. When the third solder layer is heated, the first electrode transition structure is connected to the first laser chip through the molten third solder layer. The second laser chip or the second electrode transition structure is provided with a fourth solder layer. The fourth solder layer is heated, and the second laser chip is connected to the second electrode transition structure through the molten fourth solder layer. The second solder layer is heated, and the second electrode transition structure is connected to the substrate through the molten second solder layer.

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