Semiconductor laser and manufacturing method thereof

Abstract

The invention provides a semiconductor laser which comprises a bar array which comprises a plurality of bars arranged along a first direction, and the adjacent bars are connected through soldering lugs; the end heat sinks are arranged at the two ends of the bar array in the first direction; the first base is arranged below the bar array, the top of the first base is provided with insulating heat-conducting grease, and the insulating heat-conducting grease is in contact with the bottom of the bar array; and the electrode parts are arranged at the two ends of the end heat sink. According to the semiconductor laser, the adjacent bars in the bar array are directly connected through the soldering lugs, and a transition heat sink is omitted, so that the physical gap between the adjacent bars is greatly reduced, the overlap ratio of light beams emitted by the bars is higher, and the uniformity and the power density of finally synthesized light spots are improved. The invention further provides a manufacturing method of the semiconductor laser.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a semiconductor laser and a manufacturing method thereof. Background Art

[0002] Semiconductor lasers are core components of optical communications, laser sensing, laser processing, and laser pumping, and can be directly used in laser radar, laser ranging, and other fields. Currently, they have been widely used in material processing, surface treatment, medical treatment, and scientific research.

[0003] In the prior art, in high-power lasers, multiple bars are combined together by vertical or horizontal stacking to achieve higher output power. Conventional semiconductor lasers, whether microchannel or macrochannel, include multiple bars and transition heat sinks connected alternately in the same direction. The function of the transition heat sink is to effectively guide the heat generated by each bar to the external cooling system to avoid local overheating.

[0004] In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art: due to the presence of transition heat sinks between the bars, there are obvious physical gaps between them, and there are dark areas between the light beams emitted from each bar, which affects the uniformity of the final synthesized light spot. At the same time, due to the spacing between the bars, the total beam width will increase, which will cause the power density of the light spot to decrease even if the total output power remains unchanged. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] Therefore, the object of the present invention is to provide a semiconductor laser with uniform light spot and high power density and a manufacturing method thereof.

[0007] To achieve the above object, the present invention provides a semiconductor laser in a first aspect, comprising:

[0008] A bar array, the bar array comprising a plurality of bars arranged along a first direction, wherein adjacent bars are connected by welding sheets;

[0009] End heat sinks, arranged at two ends of the bar array along the first direction;

[0010] A first base is disposed below the bar array, wherein insulating thermal grease is disposed on the top of the first base, and the insulating thermal grease contacts the bottom of the bar array;

[0011] The electrode parts are arranged at two ends of the end heat sink.

[0012] According to the semiconductor laser of the present invention, adjacent bars in the bar array are directly connected by welding pieces, eliminating the transition heat sink, so that the physical gap between adjacent bars can be greatly reduced, so that the overlap of the light beams emitted by each bar is higher, and the uniformity and power density of the final synthetic light spot are improved.

[0013] According to an embodiment of the present invention, the cross section of the end heat sink is L-shaped.

[0014] According to one embodiment of the present invention, it further includes a second base and a fastener, the middle portion of the second base has an opening, and the second base is connected to the first base by using the fastener.

[0015] According to one embodiment of the present invention, a groove is provided at the top of the first base, the insulating thermal grease is provided at the bottom of the groove, the groove is opposite to the opening, and the length of the groove in the first direction is greater than the length of the bar array.

[0016] According to one embodiment of the present invention, a first groove portion is provided on both sides of the upper end of the second base along the first direction, the top surface of the first groove portion is plated with a metal layer, the first groove portion is connected to the end heat sink and the electrode portion, and there is a gap between the end heat sink and the electrode portion.

[0017] According to an embodiment of the present invention, second grooves are provided on both sides of the lower end of the second base along the second direction, and the second grooves are complementary in shape to both ends of the first base along the second direction.

[0018] According to an embodiment of the present invention, the groove is defined by a surrounding first side wall and a second side wall, the number of the first side wall and the number of the second side wall are both 2, the second side wall is arranged along the first direction, and the first side wall is arranged along the second direction.

[0019] According to an embodiment of the present invention, a top surface of the first side wall is higher than a top surface of the second side wall.

[0020] According to an embodiment of the present invention, first connection holes are provided at two ends of the first base along the second direction, and the first connection holes are used to connect with the fasteners.

[0021] A second aspect of the present invention provides a method for manufacturing a semiconductor laser, comprising:

[0022] Sintering a bar array, wherein the bar array includes a plurality of bars arranged along a first direction, and welding sheets are provided between adjacent bars;

[0023] Encapsulating end heat sinks at both ends of the bar array;

[0024] The end heat sink is welded to the second base, wherein the contact surface of the second base for contacting with the bottom of the end heat sink is plated with a metal layer;

[0025] Encapsulating the electrode portion onto the metal layer, wherein the electrode portion is separated from the end heat sink;

[0026] Insulating thermal grease is injected into the groove of the first base to connect the first base with the second base, wherein the insulating thermal grease contacts the bottom of the bar array.

[0027] According to the method for manufacturing a semiconductor laser of the present invention, adjacent bars in a bar array are directly connected by welding sheets, thereby eliminating the transition heat sink, thereby greatly reducing the physical gap between adjacent bars, making the light beams emitted by each bar have a higher degree of overlap, thereby improving the uniformity and power density of the final synthetic light spot; the insulating thermal grease can quickly conduct the heat generated by the bar array into the first base and the second base, thereby preventing electrical short circuits, improving heat dissipation efficiency, and enabling the semiconductor laser to operate safely and stably.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. Among them:

[0030] Figure 1 It is a schematic diagram of the structure of a semiconductor laser proposed in one embodiment of the present invention.

[0031] Figure 2 It is a schematic structural diagram of the bottom of a semiconductor laser according to an embodiment of the present invention.

[0032] Figure 3 It is a schematic diagram of the exploded structure of a semiconductor laser proposed in one embodiment of the present invention.

[0033] Figure 4 yes Figure 3 A local enlarged schematic diagram of point A in the middle.

[0034] Figure 5 It is a schematic flow chart of a method for manufacturing a semiconductor laser according to an embodiment of the present invention.

[0035] Description of reference numerals:

[0036] 10-bar array, 11-bar, 12-soldering piece, 20-end heat sink, 30-electrode part, 31-third connecting hole, 40-first base, 41-first side wall, 42-second side wall, 43-first connecting hole, 44-groove, 50-second base, 51-second connecting hole, 52-second groove part, 53-first groove part, 60-fastener, 100-semiconductor laser. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limitations of the present invention. On the contrary, embodiments of the present invention include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0038] Reference below Figures 1 to 4 , describing a semiconductor laser according to an embodiment of the present invention.

[0039] Combination Figures 1 to 4 As shown, an embodiment of the present invention provides a semiconductor laser 100 , including a bar array 10 , an end heat sink 20 , an electrode portion 30 and a first base 40 .

[0040] The bar array 10 includes a plurality of bars 11 arranged along a first direction, wherein adjacent bars 11 are connected by welding sheets 12. The end heat sinks 20 are arranged at both ends of the bar array 10 along the first direction. The electrode parts 30 are arranged at both ends of the end heat sinks 20. The electrode parts 30 are connected to the end heat sinks 20. The first base 40 is arranged below the bar array 10, and the top of the first base 40 is provided with insulating thermal grease, which contacts the bottom of the bar array 10.

[0041] A bar 11 is essentially a semiconductor laser chip. Each bar 11 is connected in series. The soldering sheet 12 is a preformed soldering sheet, and its size is adapted to the size of the adjacent bar 11. The type of soldering sheet 12 is selected according to actual needs. The thickness of the soldering sheet 12 is less than the thickness of the bar 11. Exemplarily, the soldering sheet 12 uses a gold-tin soldering sheet to achieve high-reliability welding. The end heat sink 20 is also connected to the bar array 10 by the soldering sheet 12. The end heat sink 20 can be made of tungsten copper material, and the end heat sink 20 can absorb and dissipate the heat generated when the bar array is working. The shape of the end heat sink 20 is selected according to actual needs, such as a cuboid, a cylinder, etc. Exemplarily, the cross-section of the end heat sink 20 is L-shaped, that is, it is stepped. The L-shaped end heat sink 20 increases the total heat dissipation area by expanding in both vertical and horizontal directions, thereby improving the heat dissipation efficiency. The electrode part 30 is a component of the semiconductor laser 100 for connecting an external power supply. The first base 40 is used to support the bar array 10 and the end heat sink 20 for efficient heat dissipation. In one example, the material of the first base 40 is copper, which has high thermal conductivity, excellent mechanical properties and high temperature stability, effectively reduces thermal stress and prolongs the service life of the bar.

[0042] The insulating thermal grease is opposite to the bottom of the bar array 10, and the projected area of ​​the bar array 10 on the first base 40 is less than or equal to the area of ​​the insulating thermal grease. The insulating thermal grease prevents the bars from short-circuiting, and at the same time, the heat generated by the bar array 10 is evenly transferred to the first base 40, thereby improving the heat dissipation efficiency. The number of bars 11 can be set according to actual needs, and there is no limitation on this.

[0043] The electrode part 30 is connected to an external power source, the semiconductor laser 100 starts to work, and the bar array 10 emits a laser beam upward. It should be noted that the semiconductor laser in this embodiment is a pulsed laser, and the peak power generated under a narrow pulse width is relatively high.

[0044] According to the semiconductor laser of the embodiment of the present invention, adjacent bars in the bar array are directly connected by welding pieces, eliminating the transition heat sink, so that the physical gap between adjacent bars can be greatly reduced, so that the overlap of the light beams emitted by each bar is higher, thereby improving the uniformity and power density of the final synthetic light spot.

[0045] Combination Figures 1 to 4As shown, in some embodiments, the semiconductor laser 100 further includes a second base 50 and a fastener 60, the middle portion of the second base 50 has an opening, and the second base 50 is connected to the first base 40 by means of the fastener 60. The specific type of the second base 50 is set according to actual needs. Exemplarily, the second base 50 is an integrally formed part made of ceramic, which can further expand the heat dissipation area after being connected to the first base 40. A plurality of second connecting holes 51 are provided at the bottom of the second base 50, and the external liquid cooling plate can be combined with the second base 50 by the cooperation of the external fastener and the second connecting hole 51, so as to further expand the heat dissipation area and improve the heat dissipation capacity.

[0046] In one example, the wavelength bands of the bars may be the same wavelength band or different wavelength bands to achieve multi-band laser output.

[0047] A groove 44 is provided at the top of the first base 40, and insulating thermal grease is provided at the bottom of the groove 44. The groove 44 is opposite to the opening of the second base 50. The length of the groove 44 in the first direction is greater than the length of the bar array 10, so that the groove 44 can accommodate the bar array 10 and the vertical part of the L-shaped end heat sink 20. The groove 44 is defined by the surrounding first side wall 41 and the second side wall 42. The number of the first side wall 41 and the second side wall 42 are both 2, and the second side wall 42 is arranged along the first direction, and the first side wall 41 is arranged along the second direction. The specific height of the first side wall 41 and the second side wall 42 should be that the groove 44 has enough depth to accommodate the insulating thermal grease. Optionally, the second direction is perpendicular to the first direction. The specific types of the first direction and the second direction can be set according to actual needs, and there is no limitation on this. For example, the first direction is the width direction of the bar array, and the second direction is the length direction of the bar array.

[0048] In one example, the top surface of the first side wall 41 is higher than the top surface of the second side wall 42. When the semiconductor laser 100 is assembled, the first side wall 41 is located at both ends of the bar array 10 along the second direction. The first side wall 41 can extend into the space between the bar array 10 and the second base 50 for filling, thereby preventing external impurities from entering the bar array 10 and improving the reliability of the semiconductor laser 100. In addition, the electrode portion 30 is provided with a plurality of third connection holes 31, which can fix the connection terminal so as to be connected to the external power cable.

[0049] In one example, a gap is left between the first side wall 41 and the bar array 10 to prevent the bar from short-circuiting. In another example, an insulating sheet is provided between the first side wall 41 and the bar array 10 to also prevent the bar from short-circuiting.

[0050] In some embodiments, the upper end of the second base 50 is provided with a first groove portion 53 on both sides along the first direction, the top surface of the first groove portion 53 is plated with a metal layer, and the first groove portion 53 is connected to the end heat sink 20 and the electrode portion 30, wherein there is a gap between the end heat sink 20 and the electrode portion 30. Since the second base 50 is a ceramic material, the metal layer can make the end heat sink 20 and the electrode portion 30 form an electrical connection. A welding sheet is provided on the metal layer to connect the end heat sink 20 and the electrode portion 30 to the metal layer. The welding sheet on the metal layer can be an indium welding sheet with high thermal conductivity. There is a gap between the end heat sink 20 and the electrode portion 30, which can relieve the stress of the bar 11 in the bar array, avoid damaging the bar, and increase the service life of the bar. In one example, the length of the first groove portion 53 along the second direction is the same as the length of the end heat sink 20 along the same direction. The depth of the first groove 53 is the same as the height of the horizontal portion of the L-shaped end heat sink 20 . After assembly, the top surface of the second base 50 is flush with the top surface of the end heat sink 20 , which has a beautiful appearance and saves space.

[0051] The lower end of the second base 50 is provided with second grooves 52 on both sides along the second direction, and the second grooves 52 are complementary in shape to the two ends of the first base 40 along the second direction. In other words, the semiconductor laser 100 after the first base 40, the second base 50, the bar array 10, the end heat sink 20 and the electrode part 30 are assembled is in the shape of a rectangular parallelepiped as a whole, with a flat surface, a compact structure and a high degree of integration.

[0052] In addition, first connection holes 43 are provided at two ends of the first base 40 along the second direction, and the first connection holes 43 are used to connect with the fasteners 60 .

[0053] Combination Figures 1 to 5 As shown, the embodiment of the present invention further provides a method for manufacturing a semiconductor laser, comprising:

[0054] In step S102 , the bar array 10 is sintered, wherein the bar array 10 includes a plurality of bars 11 arranged along a first direction, and welding sheets 12 are disposed between adjacent bars 11 .

[0055] In this embodiment, the number of the bars 11 is set according to actual needs and is not specifically limited. The soldering pads 12 are made of gold-tin soldering pads to achieve high reliability welding.

[0056] Step S104 , packaging the end heat sinks 20 onto the two ends of the bar array 10 .

[0057] In this embodiment, the end heat sink 20 and the bar array 10 are also connected by welding pieces 12 .

[0058] Step S106 , welding the end heat sink 20 to the second base 50 , wherein a contact surface of the second base 50 for contacting the bottom of the end heat sink 20 is plated with a metal layer.

[0059] In this embodiment, the second base 50 is made of ceramic, which has high hardness and high melting point. A welding sheet is provided on the metal layer to realize electrical connection with the end heat sink 20.

[0060] Step S108 , packaging the electrode portion 30 onto the metal layer, wherein the electrode portion 30 is separated from the end heat sink 20 .

[0061] In this embodiment, the electrode portion 30 is connected to the metal layer by a welding sheet, so that the current on the electrode portion 30 can supply power to the bar array 10 through the end heat sink.

[0062] In step S110 , insulating thermal grease is injected into the groove 44 of the first base 40 to connect the first base 40 to the second base 50 , wherein the insulating thermal grease contacts the bottom of the bar array 10 .

[0063] In this embodiment, the upper surface area of ​​the insulating thermal grease is not less than the bottom surface area of ​​the bar array 10. The insulating thermal grease can quickly conduct the heat generated by the bar array into the first base and the second base, prevent electrical short circuits, improve heat dissipation efficiency, and ensure safe and stable operation of the semiconductor laser.

[0064] According to the method for manufacturing a semiconductor laser of an embodiment of the present invention, by directly connecting adjacent bars in a bar array with solder sheets, the transition heat sink is eliminated, so that the physical gap between adjacent bars can be greatly reduced, so that the overlap of the light beams emitted by each bar is higher, and the uniformity and power density of the final synthetic light spot are improved; the insulating thermal grease can quickly conduct the heat generated by the bar array into the first base and the second base, prevent electrical short circuits, improve heat dissipation efficiency, and enable the semiconductor laser to operate safely and stably. The semiconductor laser has the advantages of uniform light spot and high integration, and is suitable for surface treatment, medical treatment, scientific research and other fields.

[0065] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0066] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0068] In the description of the present invention, the directions or positional relationships indicated by the terms "left", "right", "front", "rear", etc. are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0069] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0071] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A semiconductor laser, characterized in that: include: A bar array (10), the bar array (10) comprising a plurality of bars (11) arranged along a first direction, wherein adjacent bars (11) are connected by welding sheets (12); End heat sinks (20) are arranged at two ends of the bar array (10) along the first direction; A first base (40) is disposed below the bar array (10), wherein insulating thermal grease is disposed on the top of the first base (40), and the insulating thermal grease is in contact with the bottom of the bar array (10); An electrode portion (30) is provided at two ends of the end heat sink (20).

2. The semiconductor laser according to claim 1, characterized in that The cross section of the end heat sink (20) is L-shaped.

3. The semiconductor laser according to any one of claims 1 or 2, characterized in that: It also includes a second base (50) and a fastener (60); the middle of the second base (50) has an opening; the second base (50) is connected to the first base (40) by means of the fastener (60).

4. The semiconductor laser according to claim 3, characterized in that A groove (44) is provided at the top of the first base (40), the insulating thermal grease is provided at the bottom of the groove (44), the groove (44) is opposite to the opening, and the length of the groove (44) in the first direction is greater than the length of the bar array (10).

5. The semiconductor laser according to claim 3, characterized in that The upper end of the second base (50) is provided with first grooves (53) on both sides along the first direction, the top surface of the first groove (53) is plated with a metal layer, the first groove (53) is connected to the end heat sink (20) and the electrode part (30), and there is a gap between the end heat sink (20) and the electrode part (30).

6. The semiconductor laser according to claim 4, characterized in that Second grooves (52) are provided on both sides of the lower end of the second base (50) along the second direction, and the second grooves (52) are complementary in shape to the two ends of the first base (40) along the second direction.

7. The semiconductor laser according to claim 6, characterized in that The groove (44) is defined by a surrounding first side wall (41) and a second side wall (42); the number of the first side wall (41) and the number of the second side wall (42) are both two; the second side wall (42) is arranged along the first direction; and the first side wall (41) is arranged along the second direction.

8. The semiconductor laser according to claim 7, characterized in that The top surface of the first side wall (41) is higher than the top surface of the second side wall (42).

9. The semiconductor laser according to claim 8, characterized in that The first base (40) is provided with first connection holes (43) at two ends along the second direction, and the first connection holes (43) are used to be connected to the fastener (60).

10. A method for manufacturing a semiconductor laser, characterized in that: include: Sintering a bar array (10), wherein the bar array (10) comprises a plurality of bars (11) arranged along a first direction, and welding sheets (12) are provided between adjacent bars (11); Encapsulating end heat sinks (20) at both ends of the bar array (10); The end heat sink (20) is welded to the second base (50), wherein a contact surface of the second base (50) for contacting the bottom of the end heat sink (20) is plated with a metal layer; Encapsulating the electrode portion (30) on the metal layer, wherein the electrode portion (30) is separated from the end heat sink (20); Insulating thermal grease is injected into the groove (44) of the first base (40) to connect the first base (40) to the second base (50), wherein the insulating thermal grease contacts the bottom of the bar array (10).

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