A semiconductor laser and a manufacturing method thereof

Abstract

The present invention provides a semiconductor laser, comprising: a bar array including a plurality of bars, wherein adjacent bars are connected by solder pads; a ceramic substrate array including a plurality of ceramic substrates, the top surface of the ceramic substrate being in contact with the rear cavity end face of the bar in a one-to-one correspondence; an end heat sink provided at both ends of the bar array; an electrode portion provided at both ends of the end heat sink; and a base provided below the ceramic substrate array and in contact with the bottom surface of the ceramic substrate. According to the semiconductor laser of the present invention, adjacent bars in the bar array are directly connected by solder pads, eliminating the intermediate heat sink, so that the physical gap between adjacent bars is greatly reduced, the coincidence degree of the light beams emitted by each bar is higher, and the uniformity and power density of the finally synthesized light spot are improved.

Description

Technical Field

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

[0002] A semiconductor laser is a device that uses a certain semiconductor material as a gain medium to generate stimulated emission. Semiconductor lasers have the advantages of small size, low power consumption, long life, fast modulation, and integration, and are widely used in optical communication, material processing, etc.

[0003] In the prior art, in high-power lasers, multiple bars are combined together in a vertical or horizontal stacking manner to achieve higher output power. In a conventional semiconductor laser, whether it is a microchannel structure or a macrochannel structure, the semiconductor laser includes multiple bars and a transition heat sink that are alternately connected in the same direction. The role of the transition heat sink is to effectively guide the heat generated by each bar to an external cooling system, thereby avoiding 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 existence of a transition heat sink between the bars, there is an obvious physical gap between them, and there is a dark area between the light beams emitted from each bar, which affects the uniformity of the finally synthesized light spot. At the same time, due to the interval between the bars, the total beam width will increase, and even if the total output power remains unchanged, the power density of the light spot will decrease. Summary of the Invention

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

[0006] To this end, an 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, a first aspect of the present invention provides a semiconductor laser, comprising:

[0008] A bar array, including a plurality of bars, wherein adjacent bars are connected by solder pads;

[0009] A ceramic substrate array, including a plurality of ceramic substrates, the top surface of the ceramic substrate being in one-to-one contact with the rear cavity end surface of the bar;

[0010] An end heat sink, provided at both ends of the bar array;

[0011] An electrode part, provided at both ends of the end heat sink;

[0012] A base, provided below the ceramic substrate array and welded to the bottom surface of the ceramic substrate.

[0013] In the semiconductor laser according to the present invention, adjacent bars in the bar array are directly connected by solder pads, eliminating the intermediate heat sink. Therefore, the physical gap between adjacent bars is greatly reduced, enabling a higher degree of overlap of the light beams emitted by each bar, and improving the uniformity and power density of the final combined light spot.

[0014] According to an embodiment of the present invention, the ceramic substrate includes an upper section, a middle section, and a lower section connected in sequence from top to bottom. Metal layers are plated on both end faces of the upper section along a first direction. The thickness of the middle section is less than that of the upper section. The upper sections of adjacent ceramic substrates are connected by the solder pads.

[0015] According to an embodiment of the present invention, the end heat sink is connected to the bar and the upper section by the solder pads at the inner end face close to the bar array.

[0016] According to an embodiment of the present invention, at least one terminal connection hole is provided on the electrode portion, and the electrode portion is insulated from the base.

[0017] According to an embodiment of the present invention, a groove is provided on the base, and the depth of the groove is less than or equal to the height of the ceramic substrate.

[0018] According to an embodiment of the present invention, the base is made of metal.

[0019] According to an embodiment of the present invention, an insulating heat-conducting plate is further included. Metal layers are plated on both the upper and lower surfaces of the insulating heat-conducting plate. The bottom surface of the insulating heat-conducting plate is connected to the base, and the top surface of the insulating heat-conducting plate is connected to the end heat sink and the electrode portion.

[0020] According to an embodiment of the present invention, a gap is left between the end heat sink and the electrode portion.

[0021] According to an embodiment of the present invention, the two end faces of the bar array, the ceramic substrate array, the end heat sink, the electrode portion, and the base are flush along a second direction.

[0022] A second aspect of the present invention provides a method for manufacturing a semiconductor laser, including:

[0023] Connecting a bar array and a ceramic substrate array together with solder pads to form a stacked array, where the bar array includes a plurality of bars, the ceramic substrate array includes a plurality of ceramic substrates, and the bottom surface of the ceramic substrate is in one-to-one contact with the rear cavity end face of the bar during sintering;

[0024] Placing the ceramic substrate array below the bar array and connecting the end heat sink to both ends of the bar array with solder pads;

[0025] Encapsulate the insulating heat-conducting plate on the raised parts at both ends of the base, where the middle part of the base has a groove;

[0026] Encapsulate the stack array with end heat sinks on the base, where the ceramic substrate array is welded to the groove, and the end heat sinks are welded to the insulating heat-conducting plate;

[0027] Weld the electrode part to the insulating heat-conducting plate, where there is a gap between the electrode part and the end heat sink.

[0028] According to the manufacturing method of the semiconductor laser of the present invention, by directly connecting adjacent bars in the bar array with solder pads, the transition heat sink is eliminated. Therefore, the physical gap between adjacent bars is greatly reduced, making the beam coincidence degree of each bar higher, improving the uniformity and power density of the final synthesized light spot; the ceramic substrate array quickly conducts the heat generated by the bar array into the base, improving the heat dissipation efficiency and enabling the semiconductor laser to operate safely and stably.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0030] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. Among them:

[0031] Figure 1 is a schematic structural diagram of a semiconductor laser proposed in an embodiment of the present invention.

[0032] Figure 2 is an exploded structural diagram of a semiconductor laser proposed in an embodiment of the present invention.

[0033] Figure 3 is a schematic structural diagram of a ceramic substrate in a semiconductor laser proposed in an embodiment of the present invention.

[0034] Figure 4 is Figure 2 a partial enlarged schematic diagram at A in

[0035] Figure 5 is a schematic flow diagram of the manufacturing method of a semiconductor laser proposed in an embodiment of the present invention.

[0036] Description of the Reference Numerals in the Drawings:

[0037] 10 - bar array, 11 - bar, 12 - solder tab, 20 - ceramic substrate array, 21 - ceramic substrate, 30 - end heat sink, 40 - electrode section, 41 - terminal connection hole, 50 - insulating heat conducting plate, 60 - base, 61 - groove, 100 - semiconductor laser, 211 - upper section, 212 - middle section, 213 - lower section. Detailed implementation mode

[0038] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention. On the contrary, the embodiments of the present invention include all variations, modifications and equivalents falling within the spirit and scope of the appended claims.

[0039] Refer to the following Figures 1 to 4 , and describe a semiconductor laser according to an embodiment of the present invention.

[0040] In combination with Figures 1 to 4 As shown, an embodiment of the present invention provides a semiconductor laser 100, including a bar array 10, a ceramic substrate array 20, an end heat sink 30, an electrode section 40 and a base 60.

[0041] The bar array 10 includes a plurality of bars 11, and adjacent bars 11 are connected by solder tabs 12. The ceramic substrate array 20 includes a plurality of ceramic substrates 21, and the top surface of the ceramic substrate 21 is in contact with the rear cavity end surface of the bar 11 in one-to-one correspondence. The end heat sink 30 is provided at both ends of the bar array 10. The electrode section 40 is provided at both ends of the end heat sink 30. The base 60 is provided below the ceramic substrate array 20 and is welded to the bottom surface of the ceramic substrate 21.

[0042] A bar 11 is essentially a semiconductor laser chip. Each bar 11 is connected in series. The solder tab 12 is a preformed solder tab, and the type of the solder tab 12 is selected according to actual needs. The thickness of the solder tab 12 is less than the thickness of the bar 11. Exemplarily, a gold-tin solder tab is selected for the solder tab 12 to achieve highly reliable welding. The size of the solder tab 12 is equal to the side area of the bar 11 along the first direction to avoid insufficient or excessive solder.

[0043] The number of ceramic substrates 21 and bars 11 is selected according to actual needs. The ceramic substrate 21 has a high thermal conductivity and can be made of a variety of materials, such as aluminum nitride (AlN) and silicon carbide (SiC). The ceramic substrate 21 has good thermal expansion matching with the bar 11 in a high-temperature environment, reducing stress and deformation caused by thermal expansion differences. Moreover, the ceramic substrate 21 has high strength and hardness and can withstand large mechanical stresses without being easily damaged. The thickness of the ceramic substrate 21 in the first direction is set according to actual needs. Exemplarily, the thickness of the ceramic substrate 21 is equal to the thickness of the bar 11, which helps to reduce local hot spots and enables heat to be evenly conducted between the bar and the ceramic substrate.

[0044] The end heat sink 30 can be made of tungsten copper material, and the end heat sink 30 can absorb and dissipate the heat generated when the bar array works. The shape of the end heat sink 30 is selected according to actual needs, such as a cuboid, a cylinder, etc. The side area of the end heat sink 30 in the first direction is not less than the side area of the bar 11, which is beneficial to better heat dissipation. The electrode part 40 is a component of the semiconductor laser 100 for connecting to an external power supply, and the manufacturing material can be metal, such as copper. The base 60 is used to support the bar array 10, the ceramic substrate array 20, and conduct heat to the outside. The manufacturing material of the base 60 is metal. In one example, the material of the base 60 is copper, which has high thermal conductivity, excellent mechanical properties, and high-temperature stability, effectively reducing thermal stress and extending the service life of the bar.

[0045] The electrode part 40 is connected to an external power supply, and the semiconductor laser 100 starts to work, and the bar array 10 emits laser beams 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. The wavelength bands of the bars can be the same wavelength band or different wavelength bands, and multi-wavelength laser output can be achieved under different wavelength bands.

[0046] In the semiconductor laser according to the embodiment of the present invention, adjacent bars in the bar array are directly connected by solder chips, and the transition heat sink is cancelled. Therefore, the physical gap between adjacent bars is greatly reduced, so that the beam coincidence degree of each bar is higher, improving the uniformity and power density of the final synthesized light spot.

[0047] Combined Figures 1 to 4 As shown, in some embodiments, the ceramic substrate 21 includes an upper section 211, a middle section 212, and a lower section 213 that are sequentially connected from top to bottom. Metal layers are plated on both end faces of the upper section 211 in the first direction, and the metal layers can provide good electrical connection for the solder chip 12. The upper sections 211 of adjacent ceramic substrates 21 are connected by the solder chip 12. In other words, the solder chip 12 can connect adjacent bars 11 and the ceramic substrate array 20 together, improving their mechanical strength.

[0048] The thickness of the middle section 212 is less than that of the upper section 211. The middle section 212 has no metal plating layer, and the middle sections 212 are separated from each other. Both end faces of the lower section 213 along the first direction are plated with metal layers. The middle section 212 can block the electrical connection between the upper section 211 and the lower section 213 to avoid bar short - circuit. In addition, the bottom surface of the lower section 213 is also plated with a metal layer. The lower section 213 and the base 60 can also use solder pads, but it should be noted that the melting point of the solder pads here is lower than that of the solder pad 12.

[0049] The end heat sink 30 is connected to the bar 11 and the upper section 211 by a solder pad 12 at the inner end face close to the bar array 10. The end heat sink 30 clamps the bar array 10 and the ceramic substrate array 20 at the same time, preventing the ceramic substrate array from shifting and improving the reliability of the semiconductor laser.

[0050] The base 60 is provided with a groove 61, and the depth of the groove 61 is less than or equal to the height of the ceramic substrate 21, so that the ceramic substrate 21 is firmly welded in the groove 61.

[0051] In some embodiments, the electrode part 40 is provided with at least one terminal connection hole 41, and the electrode part 40 is insulated from the base 60. The terminal connection hole 41 can fix the wiring terminal for connection with an external power cable. The insulation between the electrode part 40 and the base 60 can be achieved by using an insulating material.

[0052] In an example, the semiconductor laser includes an insulating heat - conducting plate 50. Both the upper and lower surfaces of the insulating heat - conducting plate 50 are plated with metal layers. The bottom surface of the insulating heat - conducting plate 50 is connected to the base 60, and the top surface of the insulating heat - conducting plate 50 is connected to the end heat sink 30 and the electrode part 40. There is a gap between the end heat sink 30 and the electrode part 40. Having a gap between the end heat sink 30 and the electrode part 40 can relieve the stress of the bar 11 in the bar array, avoid damaging the bar, and improve the service life of the bar.

[0053] In addition, the two end faces of the bar array 10, the ceramic substrate array 20, the end heat sink 30, the electrode part 40 and the base 60 along the second direction are flush. The specific types of the first direction and the second direction can be set according to actual needs and are not limited in this regard. 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. The second direction is perpendicular to the first direction. Thus, the whole semiconductor laser has a compact structure and is easy to arrange.

[0054] Combined Figures 1 to 5 As shown, the embodiment of the present invention also provides a manufacturing method of a semiconductor laser, including:

[0055] Step S102: Connect the bar array 10 and the ceramic substrate array 20 together with solder chips 12 to form a stacked array. The bar array 10 includes a plurality of bars 11, and the ceramic substrate array 20 includes a plurality of ceramic substrates 21. During sintering, the bottom surface of the ceramic substrate 21 is in one-to-one contact with the end face of the rear cavity of the bar 11.

[0056] In this embodiment, the rear cavity is an end face of the bar, usually a highly reflective end face, which is used to reflect light waves back to the active region. The numbers of the bars 11 and the ceramic substrates 21 are set according to actual needs, and no specific limitation is made for comparison. The solder chips 12 are selected as gold-tin solder chips to achieve high-reliability welding. During sintering, the bottom surface of the ceramic substrate 21 is in contact with the end face of the rear cavity of the bar 11, which can prevent the solder chips 12 from flowing downward continuously after melting and keep the appearance clean.

[0057] Step S104: Place the ceramic substrate array 20 below the bar array 10, and connect the end heat sinks 30 to both ends of the bar array 10 with solder chips 12.

[0058] In this embodiment, the end heat sinks 30 clamp the bar array 10 and the ceramic substrate array 20, so that the heat generated during operation can also be conducted out through the end heat sinks 30. At the same time, the position of the ceramic substrate array 20 is accurately fixed through the clamping effect.

[0059] Step S106: Package the insulating heat-conducting plates 50 on the raised parts at both ends of the base 60, where the middle part of the base 60 has a groove 61.

[0060] In this embodiment, metal layers are plated on the upper and lower end faces of the insulating heat-conducting plates 50, which can be better connected to the base 60 with solder chips.

[0061] Step S108: Package the stacked array with the end heat sinks 30 on the base 60, where the ceramic substrate array 20 is welded to the groove 61, and the end heat sinks 30 are welded to the insulating heat-conducting plates 50.

[0062] In this embodiment, the ceramic substrate array 20 is welded to the groove 61 with solder chips, and the upper end face of the end heat sink 30 is connected to the insulating heat-conducting plate 50 with solder chips. It should be noted that the melting points of the solder chips at these two places are lower than the melting point of the solder chips 12 in step S102.

[0063] Step S110: Weld the electrode part 40 to the insulating heat-conducting plate 50, where there is a gap between the electrode part 40 and the end heat sink 30.

[0064] In this embodiment, there is a gap between the electrode part 40 and the end heat sink 30, which can relieve the stress of the bars 11 in the bar array, avoid damaging the bars, and improve the service life of the bars.

[0065] According to the manufacturing method of a semiconductor laser according to an embodiment of the present invention, by directly connecting adjacent bars in a bar array with solder pads, the transition heat sink is eliminated. Therefore, the physical gap between adjacent bars is greatly reduced, making the beam coincidence degree of each bar higher, improving the uniformity and power density of the finally synthesized light spot; the ceramic substrate array can quickly conduct the heat generated by the bar array into the base, improving the heat dissipation efficiency and enabling the semiconductor laser to operate safely and stably. The semiconductor laser has the advantages of uniform light spot and high integration degree, and meets the requirements of fields such as surface treatment, medical treatment, and scientific research.

[0066] 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 "a plurality of" is two or more.

[0067] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or communicable with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be 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, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0069] In the description of the present invention, the orientation or positional relationship indicated by the terms "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0070] Any process or method description, whether in a flowchart or otherwise described herein, can be understood to represent a module, segment, or portion of code including one or more executable instructions for implementing a specific logical function or process. The scope of the preferred embodiments of the present invention includes additional implementations where functions may be executed in a substantially simultaneous manner or in the reverse order according to the functions involved, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0071] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do 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.

[0072] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A semiconductor laser, characterized in that: include: A bar array (10) includes a plurality of bar strips (11), wherein adjacent bar strips (11) are directly connected by welding sheets (12); A ceramic substrate array (20) comprising a plurality of ceramic substrates (21), wherein the top surfaces of the ceramic substrates (21) are in one-to-one contact with the end surfaces of the rear cavities of the bar strips (11); End heat sinks (30) are arranged at two ends of the bar array (10); Electrode parts (40) are arranged at both ends of the end heat sink (30); A base (60) is disposed below the ceramic substrate array (20) and is welded to the bottom surface of the ceramic substrate (21); The ceramic substrate (21) comprises an upper section (211), a middle section (212) and a lower section (213) which are connected in sequence from top to bottom; the upper section (211) is plated with metal layers on both end surfaces along a first direction; the thickness of the middle section (212) is smaller than that of the upper section (211); the middle section (212) is not plated with a metal layer; the middle sections (212) are separated from each other; the lower section (213) is plated with metal layers on both end surfaces along the first direction; and the upper sections (211) of adjacent ceramic substrates (21) are connected by means of the welding sheet (12).

2. The semiconductor laser according to claim 1, characterized in that The end heat sink (30) is connected to the bar bar (11) and the upper section (211) by means of the welding sheet (12) at the inner end surface close to the bar bar array (10).

3. The semiconductor laser according to claim 1, characterized in that At least one terminal connection hole (41) is provided on the electrode portion (40), and the electrode portion (40) is insulated from the base (60).

4. The semiconductor laser according to claim 1, characterized in that The base (60) is provided with a groove (61), and the depth of the groove (61) is less than or equal to the height of the ceramic substrate (21).

5. The semiconductor laser according to claim 1, characterized in that The base (60) is made of metal.

6. The semiconductor laser according to claim 5, characterized in that It also comprises an insulating heat conducting plate (50), the upper and lower surfaces of the insulating heat conducting plate (50) being plated with metal layers, the bottom surface of the insulating heat conducting plate (50) being connected to the base (60), and the top surface of the insulating heat conducting plate (50) being connected to the end heat sink (30) and the electrode portion (40).

7. The semiconductor laser according to claim 6, characterized in that A gap is left between the end heat sink (30) and the electrode portion (40).

8. The semiconductor laser according to any one of claims 1 to 7, characterized in that: The two end surfaces of the bar array (10), the ceramic substrate array (20), the end heat sink (30), the electrode portion (40) and the base (60) along the second direction are flush.

9. A method for manufacturing a semiconductor laser, characterized in that: include: The bar array (10) and the ceramic substrate array (20) are directly connected together by welding sheets (12) to form a stacked array, wherein the bar array (10) includes a plurality of bar arrays (11), and the ceramic substrate array (20) includes a plurality of ceramic substrates (21). During sintering, the bottom surface of the ceramic substrate (21) contacts the end surface of the rear cavity of the bar (11) in a one-to-one correspondence. The ceramic substrate (21) includes an upper section (211), a middle section (212), and a lower section (213) connected in sequence from top to bottom. The two end surfaces of the upper section (211) along a first direction are plated with a metal layer. The thickness of the middle section (212) is less than that of the upper section (211). The middle section (212) is not plated with a metal layer. The middle sections (212) are separated from each other. The two end surfaces of the lower section (213) along the first direction are plated with a metal layer. The upper sections (211) of adjacent ceramic substrates (21) are connected by welding sheets (12); Placing a ceramic substrate array (20) below a bar array (10), and connecting end heat sinks (30) to two ends of the bar array (10) using welding sheets (12); The insulating heat-conducting plate (50) is encapsulated on the protrusions at both ends of the base (60), wherein the middle portion of the base (60) has a groove (61); The stacked array with the end heat sink (30) is packaged on a base (60), wherein the ceramic substrate array (20) is welded to the groove (61), and the end heat sink (30) is welded to the insulating heat conducting plate (50); The electrode part (40) is welded to the insulating heat conductive plate (50), wherein a gap is left between the electrode part (40) and the end heat sink (30).

Images