High-power semiconductor laser array and packaging method thereof

Abstract

The invention discloses a high-power semiconductor laser array which is formed by sequentially and alternately placing and welding n semiconductor laser chips and n + 1 tungsten copper heat sinks, the width of each tungsten copper heat sink is larger than that of each semiconductor laser chip, and the upper surface and the lower surface of each semiconductor laser chip are wrapped by the tungsten copper heat sinks to form a sandwich structure. The emergent end face of the semiconductor laser chip extends out of the edge of the tungsten copper heat sink by 10-20 microns. The invention also discloses a packaging method. The current injection density of the laser module at the laser emitting end is low, so that the optical power density of the emitting end is reduced, the reliability of a device is improved, and the service life of the device is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor lasers, and in particular relates to a high-power semiconductor laser array and a packaging method thereof. Background Art

[0002] High-power semiconductor lasers have many advantages such as high brightness, long life, small size, strong stability, and easy integration. Therefore, they are widely used in application industries such as solid-state laser pumping, material processing and lithography, scientific research instruments and sensors, medical and beauty.

[0003] The output power of a single semiconductor laser chip is limited. In order to obtain higher laser power output, it is usually necessary to package several semiconductor laser chips together to form an array module. However, during the reflow soldering process, the solder between the two is easy to overflow in a molten state and climb along the chip output end face, eventually causing local contamination and shielding of the light output cavity surface, resulting in a decrease in the output light power.

[0004] In addition, when the laser is emitting light, the heat will be more concentrated at the cavity surface contamination, which can easily exceed the maximum heat threshold that the cavity surface film layer can withstand, making it easier to cause the laser chip to be damaged and fail. At the same time, because the surface of the laser chip is completely covered by a metal heat sink, the injected current is large and the optical power density at the output end is high, which can easily cause the laser end face to overheat and reduce the reliability of the device.

[0005] Therefore, in response to the above problems, the industry urgently needs a new type of high-power semiconductor laser array and a corresponding packaging method. Summary of the invention

[0006] One of the purposes of the present invention is to provide a high-power semiconductor laser array to solve the problem of excessively high optical power density at the output end of the high-power semiconductor laser array, thereby improving the reliability and service life of the semiconductor laser array.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a high-power semiconductor laser array, which is composed of n semiconductor laser chips and n+1 tungsten-copper heat sinks which are alternately placed and welded in sequence, the width of the tungsten-copper heat sink is larger than the semiconductor laser chip, the upper and lower surfaces of each semiconductor laser chip are wrapped by the tungsten-copper heat sink to form a sandwich structure, and the edge of the tungsten-copper heat sink is extended 10 to 20 μm in front of the emission end of the semiconductor laser chip.

[0008] Furthermore, all the emission end faces of the semiconductor laser chips are aligned.

[0009] Furthermore, the length of all tungsten copper heat sinks is slightly larger than that of the semiconductor laser chip by 1 to 2 mm.

[0010] A second object of the present invention is to provide a packaging method for a high-power semiconductor laser array to solve the problem of solder overflowing from the end surface during reflow soldering of a high-power semiconductor laser chip, thereby improving the packaging yield of the semiconductor laser array.

[0011] The technical solution adopted by the present invention to solve the technical problem is: a packaging method for a high-power semiconductor laser array, the steps are: S1, selecting a cube with a V-shaped groove on the upper surface, and opening an inclined groove with a width between the length of the semiconductor laser chip and the tungsten copper heat sink on one surface of the groove to obtain a packaging fixture; S2, stack the semiconductor laser chip and the tungsten copper heat sink in sequence on the packaging fixture, so that the emission end surface of the semiconductor laser chip protrudes into the inclined groove of the packaging fixture. Since the length of the tungsten copper heat sink is greater than the length of the semiconductor laser chip, the tungsten copper heat sink will be stacked outside the inclined groove of the packaging fixture. The distance the emission end surface of the semiconductor laser chip protrudes is the depth of the inclined groove. Then the semiconductor laser chip and the tungsten copper heat sink are packaged.

[0012] Furthermore, all the surface connections between the semiconductor laser chip and the tungsten copper heat sink are formed by metal solder reflow soldering.

[0013] The beneficial effects of the present invention are: The output end face of the laser chip in the present invention has a certain forward extension distance relative to the edge of the tungsten copper heat sink. Compared with the semiconductor laser array in which the traditional chip is flush with the front end face of the heat sink, the problem of solder overflow and climbing can be effectively solved during reflow soldering, thereby avoiding contamination of the laser output cavity surface and greatly improving the packaging yield of the device.

[0014] In the present invention, the front edge of the output end of the laser chip is not directly covered by the tungsten copper heat sink, and the current injection of the laser module is along a direction perpendicular to the contact surface. Compared with the traditional semiconductor laser array in which the chip is flush with the front end of the heat sink, under the same current injection conditions.

[0015] The laser module of the present invention has a low current injection density at the laser output end, thereby reducing the optical power density at the output end and improving the reliability and service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of a semiconductor laser array according to an embodiment of the present invention; Figure 2 A schematic diagram of a semiconductor laser array packaging fixture provided by an embodiment of the present invention.

[0017] The reference numerals of the figures are: 1 - semiconductor laser chip, 2 - tungsten copper heat sink, 3 - inclined groove. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Example 1

[0019] Reference Figure 1 As shown, a high-power semiconductor laser array disclosed in the present invention is composed of n semiconductor laser chips 1 and n+1 tungsten-copper heat sinks 2 which are alternately placed and welded in sequence. The width of the tungsten-copper heat sink 2 is larger than the semiconductor laser chip 1. The upper and lower surfaces of each semiconductor laser chip 1 are wrapped by the tungsten-copper heat sink 2 to form a sandwich structure. The emission end of the semiconductor laser chip 1 extends outward from the edge of the tungsten-copper heat sink 2 by 10 to 20 μm.

[0020] In order to ensure good heat dissipation performance of the device, the semiconductor laser chip 1 and the tungsten copper heat sink 2 need to be alternately welded in sequence to form a stacked module, and the emission end face of the semiconductor laser chip 1 is aligned with the edge of the tungsten copper heat sink 2. All the emission end faces of the semiconductor laser chips 1 are aligned.

[0021] The high-power semiconductor laser array in the embodiment of the present invention includes 7 tungsten copper heat sinks 2 and 6 semiconductor laser chips 1, and the semiconductor laser chips 1 and the tungsten copper heat sinks 2 are stacked alternately in sequence. The length of the tungsten copper heat sink 2 is slightly greater than the length of the semiconductor laser chip 1 by about 1 to 2 mm, and the width of the laser chip is less than the width of the tungsten copper heat sink. All the emission end faces of the semiconductor laser chips 1 are aligned, and all the edges of the tungsten copper heat sinks 2 are aligned. Example 2

[0022] The present invention discloses a packaging method for a high-power semiconductor laser array, so as to achieve that the emission end face of a semiconductor laser chip 1 extends a certain length ahead of the edge of a tungsten copper heat sink 2, and the emission end faces of multiple semiconductor laser chips 1 and the edges of multiple tungsten copper heat sinks 2 can be aligned respectively; the steps are as follows.

[0023] S1, the packaging method of the present invention requires the use of a packaging fixture with a bevel groove 3, and the packaging fixture used during packaging is as follows Figure 2 As shown, there is a groove in the middle of the left inclined surface of the fixture, the width of the groove is larger than the width of the semiconductor laser chip 1 and smaller than the width of the tungsten copper heat sink 2, and the depth of the groove is between 10 and 20 μm.

[0024] S2, stack the semiconductor laser chip 1 and the tungsten copper heat sink 2 on the packaging fixture in sequence. When placing the semiconductor laser chip 1 and the tungsten copper heat sink 2, the front faces of both are perpendicular to the left bevel of the fixture, and their bottom faces are parallel to the right bevel of the fixture. The semiconductor laser chip 1 is placed in the groove, and the tungsten copper heat sink 2 is placed above the groove, so that the emission end face of the semiconductor laser chip 1 extends to the bevel groove 3 of the packaging fixture. Since the length of the tungsten copper heat sink 2 is greater than the length of the semiconductor laser chip 1, the tungsten copper heat sink 2 will be stacked outside the bevel groove 3 of the packaging fixture, and the distance before the emission end face of the semiconductor laser chip 1 extends is the depth of the bevel groove 3. Then the semiconductor laser chip 1 and the tungsten copper heat sink 2 are packaged.

[0025] All the surface connections between the semiconductor laser chips 1 and the tungsten copper heat sink 2 are formed by reflow soldering of metal solder.

[0026] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high power semiconductor laser array, characterized in that: The invention is composed of n semiconductor laser chips (1) and n+1 tungsten copper heat sinks (2) which are alternately placed and welded in sequence, wherein the width of the tungsten copper heat sink (2) is greater than that of the semiconductor laser chip (1), the upper and lower surfaces of each semiconductor laser chip (1) are wrapped by the tungsten copper heat sink (2), and the emission end of the semiconductor laser chip (1) protrudes 10 to 20 μm from the edge of the tungsten copper heat sink (2).

2. A high power semiconductor laser array according to claim 1, characterized in that: The emission end faces of all semiconductor laser chips (1) are aligned.

3. A high power semiconductor laser array according to claim 1 or 2, characterized in that: The length of all tungsten copper heat sinks (2) is 1 to 2 mm longer than that of the semiconductor laser chip (1).

4. A packaging method for a high-power semiconductor laser array as claimed in claim 1, characterized in that: The steps are: S1, selecting a cube with a V-shaped groove on its upper surface, and forming an inclined groove (3) with a width between the length of the semiconductor laser chip (1) and the length of the tungsten copper heat sink (2) on one surface of the groove, to obtain a packaging fixture; S2, placing a semiconductor laser chip (1) and a tungsten copper heat sink (2) on a packaging fixture in sequence, such that the emission end face of the semiconductor laser chip (1) extends into the inclined surface groove (3), the tungsten copper heat sink (2) is stacked outside the inclined surface groove (3), and the emission end face of the semiconductor laser chip (1) extends forward by a distance equal to the depth of the inclined surface groove (3), and then packaging the semiconductor laser chip (1) and the tungsten copper heat sink (2).

5. The packaging method of a high-power semiconductor laser array according to claim 4, characterized in that: All surface connections between the semiconductor laser chip (1) and the tungsten copper heat sink (2) are formed by metal solder reflow soldering.

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