Polygonal quasi-continuous semiconductor laser stack array and packaging method thereof

Abstract

The invention relates to a polygonal quasi-continuous semiconductor laser stack array and a packaging method thereof, and belongs to the technical field of lasers. The laser stack array comprises laser modules, an upper base, a lower base and laser crystals, the laser modules are arranged on the upper side of the lower base, the laser crystals are arranged on the lower side of the upper base, and the upper base is fixed to the lower base; the laser module comprises bar arrays, connecting electrodes, insulating sheets, a base heat sink, circuit boards and electrode sheets, a penetrating groove is formed in the middle of the base heat sink, the bar arrays are fixed in the groove through the insulating sheets, the connecting electrodes are arranged between the adjacent bar arrays, the circuit boards are arranged at the two ends of the base heat sink respectively, and the electrode sheets are arranged on the circuit boards. The circuit board is connected with a bar array on the side through an electrode plate. The semiconductor laser stack array is concentric, part of the side pumping laser crystal, the laser bar and the laser crystal are in large-area contact with the heat sink, generated heat can be dissipated in a conduction cooling mode, and packaging is convenient and fast.

Description

Technical Field

[0001] The invention relates to a polygonal quasi-continuous semiconductor laser stack array and a packaging method thereof, belonging to the technical field of lasers. Background Art

[0002] All-solid-state lasers pumped by semiconductor lasers have the advantages of compact structure, high conversion efficiency, high power, high beam quality, high stability, and long life, and have been widely used in military, material processing, space communications, laser display, atmospheric detection and other fields. The emission spectrum of semiconductor lasers can be well matched with the absorption band of crystal materials through temperature control, which effectively improves the absorption efficiency of laser crystals for pump light while reducing heat generation. It is the core component of all-solid-state lasers.

[0003] Commonly used semiconductor laser stacks are mostly planar stacks or are evenly distributed around the crystal rod in the shape of an equilateral triangle, equilateral pentagon, equilateral heptagon, etc. This stack structure is mostly used as a continuous or high duty cycle pump source. Its cooling structure and integration structure are relatively complex, installation is cumbersome, and the volume is large. For example, the Chinese patent document CN118040445A discloses a device and method for improving the performance of a semiconductor side pump module. The pump source is a linear array evenly distributed around the crystal rod in the shape of an equilateral triangle. The heat dissipation method is to cool the laser crystal and the laser bar separately through water. The water channel structure is complex, not easy to integrate, and there is a risk of water leakage. In practical applications, for small-volume, low-duty-cycle quasi-continuous pump source solid lasers, complex cooling structures and integration methods are not required, and heat can be dissipated by conduction cooling or a combination of conduction cooling and simple liquid cooling. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a polygonal quasi-continuous semiconductor laser stack array, which is applied to a solid laser with a small volume and low duty cycle quasi-continuous pump source. The semiconductor laser stack array is concentric, and some side pumps the laser crystal. The laser bars and the laser crystal are in contact with a heat sink over a large area. The heat generated can be dissipated by conduction cooling, and the packaging is convenient.

[0005] The present invention also provides a packaging method for the polygonal quasi-continuous semiconductor laser array.

[0006] The technical solution of the present invention is as follows:

[0007] A polygonal quasi-continuous semiconductor laser stack array comprises a laser module, an upper base, a lower base and a laser crystal, wherein a plurality of laser modules are arranged on the upper side of the lower base, a laser crystal is arranged on the lower side of the upper base, and the upper base is fixed to the lower base;

[0008] The laser module includes a bar array, a connecting electrode, an insulating sheet, a base heat sink, a circuit board and an electrode sheet, wherein a through groove is provided in the middle of the base heat sink, and several bar arrays are fixed in the groove through the insulating sheet, and connecting electrodes are provided between adjacent bar arrays. Circuit boards are provided at both ends of the base heat sink, and the circuit boards are connected to the side bar arrays through the electrode sheets.

[0009] According to a preferred embodiment of the present invention, the bar array includes laser bars and tungsten copper heat sinks, and tungsten copper heat sinks are fixedly arranged on both sides of the laser bars. The tungsten copper heat sinks are used for heat conduction of the laser bars.

[0010] Preferably according to the present invention, the wavelength range of the laser bar is 450nm-1064nm, and the peak power range is 50W-500W.

[0011] Preferably according to the present invention, the insulating sheet is an aluminum nitride ceramic sheet.

[0012] Preferably according to the present invention, the groove is a polygonal groove, such as a triangle, a pentagon, a hexagon, a enneagon, etc., to facilitate fixing the bar array.

[0013] Preferably, according to the present invention, a water channel is provided in the upper base. In addition to fixing the overall package, the upper base is also used for heat dissipation of the laser crystal. For laser modules with a duty cycle of less than 1%, conduction heat dissipation can be adopted. For laser modules with a duty cycle between 1% and 3%, water can be used to dissipate heat through a water channel, and the water temperature is between 18°C ​​and 25°C, so as to improve the heat dissipation efficiency.

[0014] Preferably according to the present invention, the laser crystal is columnar in shape, and is made of crystals such as Nd:YAG, Yb:YAG, Nd:YVO4, Tm:YAG or Tm:YLF.

[0015] The packaging method of the polygonal quasi-continuous semiconductor laser array comprises the following steps:

[0016] (1) The tungsten copper heat sink is welded to both sides of the laser bar through the primary solder (such as AuSn solder) to form a bar array. The bar array can be in the range of 1 bar to 10 bar. The bar array is welded to the insulating sheet through the secondary solder (such as SnInAg solder);

[0017] (2) The insulating sheet is placed in the groove of the base heat sink, and connecting electrodes are arranged between the bar arrays. A third-level solder is placed between the insulating sheet and the groove of the base heat sink, and a third-level solder is placed at the contact position between the connecting electrode and the insulating sheet. The welding is heated to fix the relative positions of the connecting electrode, the insulating sheet and the heat sink base. The electrode sheet is welded to the tungsten copper heat sink of the side bar array by the fourth-level solder. The electrode sheet is welded to the circuit board by Sn solder. The circuit board and the base heat sink can be fixed by welding or bolts to form a laser module.

[0018] (3) The laser modules assembled in step (2) are fixed to the lower base by bolts. The laser crystal is welded to the lower side of the upper base by indium solder. The upper base is bolted to the lower base. The laser crystal is located in the space surrounded by the grooves of the heat sinks of each base, thereby completing the packaging.

[0019] Preferably according to the present invention, the melting points of the primary solder, the secondary solder, the tertiary solder and the quaternary solder decrease in sequence.

[0020] The beneficial effects of the present invention are:

[0021] The present invention is applied to a solid-state laser with a quasi-continuous pump source of small size and low duty cycle. The semiconductor lasers are stacked concentrically, and the laser crystals are partially pumped from the side. The laser bars and the laser crystals are in contact with a large area of ​​the heat sink. The generated heat can be dissipated by conduction cooling. The packaging is convenient and has the advantages of compact structure, small size, simple heat dissipation method, easy integration, low cost, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the laser module of the present invention;

[0023] Figure 2 This is a schematic diagram of the laser module fixing structure of the present invention;

[0024] Figure 3 It is a schematic diagram of the upper base structure of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the present invention;

[0026] Figure 5 It is a temperature simulation diagram of the present invention.

[0027] Among them: 1. Laser bar; 2. Tungsten copper heat sink; 3. Connecting electrode; 4. Insulating sheet; 5. Base heat sink; 6. Circuit board; 7. Electrode sheet A; 8. Electrode sheet B; 9. Laser module; 10. Lower base; 11. Fixing screw hole; 12. Laser crystal; 13. Upper base; 14. Indium solder; 15. Water channel. DETAILED DESCRIPTION

[0028] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings, but is not limited thereto.

[0029] Embodiment 1:

[0030] like Figure 1-4As shown, this embodiment provides a polygonal quasi-continuous semiconductor laser stack array, including a laser module 9, an upper base 13, a lower base 10 and a laser crystal 12, wherein a plurality of laser modules 9 are arranged on the upper side of the lower base 10, a laser crystal 12 is arranged on the lower side of the upper base 13, and the upper base 13 is fixed to the lower base 10;

[0031] The laser module 9 includes a bar array, a connecting electrode 3, an insulating sheet 4, a base heat sink 5, a circuit board 6, an electrode sheet A7 and an electrode sheet B8, wherein a through groove is provided in the middle of the base heat sink 5, and a plurality of bar arrays are fixed in the groove through the insulating sheet 4, and a connecting electrode 3 is provided between adjacent bar arrays. Circuit boards 6 are provided at both ends of the base heat sink 5, and circuit boards 6 are provided on both adjacent sides of one end of the base heat sink 5. The side bar arrays are connected to the circuit board through the electrode sheet A7, and the two circuit boards are connected through the electrode sheet B8. The power supply contact position is moved to the side of the base heat sink through the circuit board and the two electrode sheets to facilitate subsequent power-on. The circuit board plays the role of insulation from the base heat sink and connection of the electrode sheet with the external power supply for conductivity.

[0032] The bar array includes a laser bar 1 and a tungsten copper heat sink 2. Tungsten copper heat sinks 2 are fixedly arranged on both sides of the laser bar 1. The tungsten copper heat sink is used for heat conduction of the laser bar.

[0033] The wavelength range of the laser bar 1 is 450nm~1064nm.

[0034] The insulating sheet 4 is an aluminum nitride ceramic sheet.

[0035] The groove is a polygonal groove, such as a triangle, a pentagon, a hexagon, a enneagon, etc., which is convenient for fixing the bar array.

[0036] A water channel 15 is provided in the upper base 13. In addition to fixing the overall package, the upper base is also used for heat dissipation of the laser crystal. For laser modules with a duty cycle of less than 1%, conduction heat dissipation can be used. For laser modules with a duty cycle between 1% and 3%, water can be used to dissipate heat through the water channel. The water temperature is between 18°C ​​and 25°C to improve the heat dissipation efficiency.

[0037] The laser crystal 12 is in the shape of a column.

[0038] The packaging method of the polygonal quasi-continuous semiconductor laser array comprises the following steps:

[0039] (1) The tungsten copper heat sink is welded to both sides of the laser bar through the primary solder (such as AuSn solder) to form a bar array. The bar array can be in the range of 1 bar to 10 bar. The bar array is welded to the insulating sheet through the secondary solder (such as SnInAg solder);

[0040] (2) The insulating sheet is placed in the groove of the base heat sink, and connecting electrodes are arranged between the bar arrays. A third-level solder is placed between the insulating sheet and the groove of the base heat sink, and a third-level solder is placed at the contact position between the connecting electrode and the insulating sheet. The welding is heated to fix the relative positions of the connecting electrode, the insulating sheet and the heat sink base. The electrode sheet A is welded on the tungsten copper heat sink of the side bar array by the fourth-level solder. The electrode sheet A and the electrode sheet B are welded to the circuit board by Sn solder. The circuit board and the base heat sink can be fixed by welding or bolts to form a laser module 9;

[0041] The melting points of primary solder, secondary solder, tertiary solder, and quaternary solder decrease in sequence;

[0042] (3) The laser modules assembled in step (2) are fixed to the lower base by bolts. The laser crystal is welded to the lower side of the upper base by indium solder 14. The upper base is bolted to the lower base. The laser crystal is located in the space surrounded by the grooves of the heat sinks of each base to complete the packaging.

[0043] The peak power of the laser bar is 100W, the duty cycle is 3%, the water flow rate of the water channel is 10L / min, the water temperature is 20℃, the water channel diameter is 4mm, and the laser crystal doping concentration is 0.6% Nd:YAG. The temperature of this embodiment is simulated. The simulation results are as follows Figure 5 As shown, the maximum temperature of the laser bar is about 28°C, the average temperature is about 25°C, the maximum temperature of the laser crystal is about 45°C, the average temperature is about 38°C, and the laser bar and laser crystal can work normally.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A polygonal quasi-continuous semiconductor laser array, characterized in that: It includes a laser module, an upper base, a lower base and a laser crystal, wherein a plurality of laser modules are arranged on the upper side of the lower base, a laser crystal is arranged on the lower side of the upper base, and the upper base is fixed to the lower base; The laser module includes a bar array, a connecting electrode, an insulating sheet, a base heat sink, a circuit board and an electrode sheet, wherein a through groove is provided in the middle of the base heat sink, and several bar arrays are fixed in the groove through the insulating sheet, and connecting electrodes are provided between adjacent bar arrays. Circuit boards are provided at both ends of the base heat sink, and the circuit boards are connected to the side bar arrays through the electrode sheets.

2. The polygonal quasi-continuous semiconductor laser array as claimed in claim 1, characterized in that: The bar array includes laser bars and tungsten-copper heat sinks, and tungsten-copper heat sinks are fixedly arranged on both sides of the laser bars.

3. The polygonal quasi-continuous semiconductor laser array as claimed in claim 2, characterized in that: The wavelength range of the laser bar is 450nm~1064nm, and the peak power range is 50W~500W.

4. The polygonal quasi-continuous semiconductor laser array as claimed in claim 1, characterized in that: The insulating sheet is an aluminum nitride ceramic sheet.

5. The polygonal quasi-continuous semiconductor laser array as claimed in claim 1, characterized in that: The groove is a polygonal groove.

6. The polygonal quasi-continuous semiconductor laser array as claimed in claim 1, characterized in that: A water channel is arranged in the upper base.

7. The polygonal quasi-continuous semiconductor laser array as claimed in claim 1, characterized in that: The laser crystal is columnar in shape and is made of Nd:YAG, Yb:YAG, Nd:YVO4, Tm:YAG or Tm:YLF.

8. The method for packaging a polygonal quasi-continuous semiconductor laser array as claimed in claim 2, characterized in that: Here are the steps: (1) The tungsten copper heat sink is welded to both sides of the laser bar through the primary solder to form a bar array, and the bar array is welded to the insulating sheet through the secondary solder; (2) The insulating sheet is placed in the groove of the base heat sink, and connecting electrodes are arranged between the bar arrays. A third-level solder is placed between the insulating sheet and the groove of the base heat sink, and a third-level solder is placed at the contact position between the connecting electrode and the insulating sheet. The heating and welding are performed to fix the relative positions of the connecting electrode, the insulating sheet and the heat sink base. An electrode sheet is welded on the tungsten copper heat sink of the side bar array by a fourth-level solder, and the electrode sheet is welded to the circuit board by Sn solder to form a laser module; (3) The laser modules assembled in step (2) are fixed to the lower base by bolts. The laser crystal is welded to the lower side of the upper base by indium solder. The upper base is bolted to the lower base. The laser crystal is located in the space surrounded by the grooves of the heat sinks of each base, thereby completing the packaging.

9. The method for packaging a polygonal quasi-continuous semiconductor laser array as claimed in claim 8, characterized in that: The melting points of primary solder, secondary solder, tertiary solder, and quaternary solder decrease in sequence.

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