High-power laser module and packaging method thereof

Abstract

The invention relates to a high-power laser module and a packaging method thereof, belongs to the technical field of lasers, and solves the technical problems of high thermal resistance and short service life caused by welding flux aging of the laser module, and the packaging method comprises the steps of sandwich sintering, first ceramic chip welding, welding assembly installation, second ceramic chip welding and packaging. The high-power laser module comprises a welding assembly, a water passing block, a second ceramic chip, a wire and a shell. The welding assembly comprises a sandwich, an electrode lap joint block and a first ceramic wafer. And the electrode lapping blocks are connected with electrodes of the sandwich. The sandwich comprises a chip and electrodes, the electrodes are located on the two faces of the chip, and the chip and the electrodes are sintered and combined. The electrode lap joint block, the electrode and the chip are all connected with the first ceramic chip and the second ceramic chip. The first ceramic chip is a radiating fin and comprises a bottom surface and a fin. The bottom face of the fin is connected with a row of sandwich bodies with electrode lap joint blocks in a welded mode, and the fin is formed by grooving and used for heat dissipation. The invention is used for the high-power laser module and the packaging thereof.

Description

Technical Field

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

[0002] With the development of laser technology, lasers have been fully applied in various fields. In particular, semiconductor lasers have been widely used in material processing, medical cosmetology, laser radar, aerospace and other fields due to their small size, high efficiency, easy integration and maintenance-free.

[0003] To ensure that the energy of the semiconductor laser meets the use requirements, the laser has multiple bar chips that are connected in parallel and series to increase the power. When the laser is working, the power density is high and the heat is serious, which leads to a high temperature rise of the chip. The chip and solder working at high temperature for a long time can easily cause chip failure.

[0004] The main process of traditional laser module packaging is as follows: (1) welding the laser chip and the tungsten copper heat sink with gold-tin solder; (2) welding the tungsten copper bottom surface and the secondary heat sink ceramic with tin-silver-copper solder; (3) welding the ceramic heat sink and the water-permeable heat dissipation component with soft solder; such a packaging structure determines the heat dissipation path of the chip. First, the chip transfers the waste heat to the tungsten copper, then the tungsten copper bottom surface transfers the heat to the ceramic, and then the ceramic transfers the heat to the water-permeable heat dissipation component. Finally, the cooling circulating water takes away the heat to complete the heat dissipation.

[0005] This packaging structure will cause the chip heat to be unable to be transmitted to the cooling circulating water through the shortest path, which will increase the thermal resistance of the entire product and cause the chip temperature to be too high, resulting in chip failure. The ceramic bottom and heat dissipation components are welded with soft solder. The welding quality determines the thermal resistance of the product. Soft solder will age during long-term operation, causing product failure. Summary of the invention

[0006] In order to overcome the shortcomings of laser module packaging, such as large thermal resistance and short life due to solder aging, the present invention proposes a high-power laser module and a packaging method thereof.

[0007] The technical solution adopted by the present invention to solve the technical problem is:

[0008] A high-power laser module packaging method comprises the following steps:

[0009] Step 1: Sandwich sintering

[0010] Sintered solder is placed between the high-power laser chip and the electrode, and the chip and the electrode are sintered and bonded by a sintering process. The electrodes are located on both sides of the chip to obtain a sandwich of electrode-chip-electrode sintering bonding.

[0011] Step 2: First Ceramic Plate Welding

[0012] The electrode overlapping block is connected to two electrodes of the sandwich, so that several sandwiches with electrode overlapping blocks are arranged in sequence to form a row of sandwiches with electrode overlapping blocks.

[0013] A row of sandwiches with electrode overlap blocks are welded to the first ceramic sheet by welding. The electrode overlap blocks, electrodes, and chips are all connected to the first ceramic sheet to form a welded assembly in which a row of sandwiches with electrode overlap blocks and the first ceramic sheet are combined.

[0014] Step 3, welding assembly installation

[0015] Install the welding assembly on the water block, with the sandwich of the welding assembly outside the water block. Place a waterproof gasket between the welding assembly and the water block. During installation, the first ceramic sheet positioning hole, the waterproof gasket positioning hole, and the water block positioning hole correspond to each other.

[0016] Step 4: Welding the second ceramic sheet

[0017] The two second ceramic sheets are respectively welded to the two sides of a sandwich with a row of electrode overlap blocks by welding technology. The electrode overlap blocks, electrodes, and chips are all connected to the second ceramic sheet. The second ceramic sheet is perpendicular to the first ceramic sheet.

[0018] Step 5: Packaging

[0019] The wires are welded on the welding assembly, and the assembled welding assembly, water-passing block, waterproof gasket 6, second ceramic sheet and wires are installed in the housing to obtain a high-power laser module.

[0020] In the above high-power laser module packaging method, in step 1, the sintering process is carried out in a eutectic furnace.

[0021] In the above-mentioned high-power laser module packaging method, in step 1, the sintering solder used in the sintering process is gold-tin solder, and the electrode is a tungsten-copper electrode.

[0022] In the above high-power laser module packaging method, in step 2, the first ceramic sheet is a heat dissipation fin, including a bottom surface and a fin. The bottom surface is a welding surface, connected to the electrode lap block, the electrode, and the chip, and the fin is formed by grooves for heat dissipation. The material of the first ceramic sheet is aluminum nitride.

[0023] In the above-mentioned high-power laser module packaging method, in step 2 and step 4, the welding process is solder welding, and the solder is tin-silver-copper solder.

[0024] A high-power laser module comprises a welding assembly, a water-passing block, two second ceramic sheets, a wire and a shell.

[0025] The welding assembly, the water passing block and the second ceramic sheet are located in the outer shell.

[0026] The welding assembly includes a sandwich, an electrode overlapping block, and a first ceramic sheet.

[0027] The electrode overlap block is connected to the electrodes of the sandwich. A row of sandwiches with electrode overlap blocks is welded and connected to the first ceramic sheet.

[0028] The electrode bridging block, the electrode and the chip are all connected to the first ceramic sheet.

[0029] The sandwich comprises a chip and electrodes. The electrodes are located on two sides of the chip, and the chip and the electrodes are sintered and combined.

[0030] The two second ceramic sheets are respectively welded to two sides of a sandwich with a row of electrode overlap blocks, and the electrode overlap blocks, electrodes and chips are all connected to the second ceramic sheets. The second ceramic sheets are perpendicular to the first ceramic sheets.

[0031] The lead is connected to the electrode and led out from the shell.

[0032] The above-mentioned high-power laser module also includes a waterproof gasket.

[0033] The first ceramic sheet is a heat dissipation fin, including a bottom surface and fins. The bottom surface is welded to a row of sandwiches with electrode overlap blocks, and the fins are formed by grooves for heat dissipation. The first ceramic sheet is provided with a first ceramic sheet positioning hole for installation and positioning of the welding assembly on the water flow block.

[0034] The water block is used for heat dissipation of the first ceramic sheet, and is provided with a water inlet, a water outlet, and a water block positioning hole. The water inlet and the water outlet are used for the inlet and outlet of cooling water, and the water block positioning hole is used for the installation of the welding assembly on the water block.

[0035] In the above high-power laser module, the waterproof gasket is located between the welding assembly and the water block, and is used for sealing the welding assembly and the water block. The waterproof gasket is provided with a waterproof gasket positioning hole, which is used for installing and positioning the welding assembly on the water block.

[0036] In the above-mentioned high-power laser module, the chip is a high-power laser chip, and the electrode is a tungsten-copper electrode.

[0037] The sintering solder used in the sintering of the chip and the electrode is gold-tin solder. The first ceramic sheet material is aluminum nitride.

[0038] In the above-mentioned high-power laser module, the row of sandwiches with electrode overlapping blocks are welded to the first ceramic sheet and the second ceramic sheet, and the solder for the welding connection is tin-silver-copper solder.

[0039] The beneficial effects of the present invention are:

[0040] A high-power laser module packaging method reduces the soft solder welding process of the ceramic bottom and the heat dissipation component, reduces the thermal resistance of the laser module, and prevents the laser module from failing due to excessive operating temperature rise.

[0041] A high-power laser module packaging method includes slotting the bottom of the ceramic. Since the laser module operates in a pulsed mode, slotting the bottom of the ceramic can effectively alleviate the damage to the chip caused by thermal stress.

[0042] A high-power laser module packaging method performs ceramic welding on the tungsten-copper cross section at the edge of a chip for heat dissipation, which can increase the heat dissipation path of the chip and reduce failure of the chip edge due to excessive temperature rise. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a front view of the sandwich structure of Example 1 of the present invention;

[0044] Figure 2 is a side view of the sandwich structure of Example 1 of the present invention;

[0045] Figure 3 is a three-dimensional diagram of the first ceramic sheet of Example 1 of the present invention;

[0046] Figure 4 is a bottom view of the first ceramic sheet of Example 1 of the present invention;

[0047] Figure 5 is a side view of the first ceramic sheet of Example 1 of the present invention;

[0048] Figure 6 It is a schematic diagram of the combination of a sandwich, an electrode overlap block, and a first ceramic sheet according to Embodiment 1 of the present invention;

[0049] Figure 7 yes Figure 6 Enlarged view of point A in the middle;

[0050] Figure 8 This is a three-dimensional diagram of a water-passing block according to Embodiment 1 of the present invention;

[0051] Fig. 9 This is a top view of the water passing block in Embodiment 1 of the present invention;

[0052] Fig.10 This is a bottom view of the water-passing block of Embodiment 1 of the present invention;

[0053] Fig.11 is a stereogram of a waterproof gasket according to embodiment 1 of the present invention;

[0054] Fig.12 It is a three-dimensional diagram of the combination of the water-passing block, the sandwich, the electrode overlap block, and the first ceramic sheet in Example 1 of the present invention;

[0055] Fig.13 is a front view of the second ceramic sheet;

[0056] Fig.14 This is a top view summary diagram of a high-power laser module according to Embodiment 1 of the present invention;

[0057] Fig.15 yes Fig.14 Enlarged view of point B in the middle.

[0058] Figure numerals: 1. Sandwich, 2. Electrode overlapping block, 3. First ceramic sheet, 4. Water flow block, 5. Waterproof gasket, 6. Second ceramic sheet, 7. Sintered solder, 8. Sandwich edge, 11. Chip, 12. Electrode, 31. Bottom surface, 32. Fin, 33. First ceramic sheet positioning hole, 41. Water inlet, 42. Water outlet, 43. Water flow block positioning hole, 51. Waterproof gasket positioning hole. DETAILED DESCRIPTION

[0059] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] Example 1

[0061] A high-power laser module packaging method comprises the following steps:

[0062] 1. Use a eutectic furnace to sinter the laser chip, gold-tin solder, and tungsten-copper electrode. After sintering, it is called a "sandwich". Figure 1 , 2 .

[0063] 2. Weld multiple sandwiches 1 and electrode bridge blocks 2 on the first aluminum nitride ceramic sheet 3 ( Figure 3 , 4 , 5) upper surface, such as Figure 6 , 7 .

[0064] 3. Put the water block heat dissipation component ( Figure 8 , 9 , 10) Waterproof gasket ( Fig.11 ), sandwich and ceramic sheet welding assemblies ( Fig.12 ), fixed assembly through four positioning holes (such as Fig. 9 ), the ceramic sheet and the water block are sealed with a waterproof gasket to prevent water leakage.

[0065] 4. Use tin-silver-copper solder and the second ceramic sheet ( Fig.13 ) for welding, such as Fig.14 , 15 .

[0066] 5. Carry out wire welding, shell installation and other processes on the assembled products, and finally install the products in the laser control system.

[0067] According to the packaging characteristics of the laser module, the present invention cuts off the upper surface of the heat dissipation component with water passing through, allowing the ceramic bottom surface to directly contact the cooling circulating water, thereby reducing thermal resistance and reducing the soft solder welding process between the ceramic bottom and the surface of the heat dissipation component; the surface where the ceramic contacts the cooling water is grooved (grooved), and the grooves are formed to form fins 32, thereby increasing the heat exchange area and alleviating chip failure caused by thermal stress; the tungsten copper section at the edge of the laser chip is also welded with ceramic to increase the heat dissipation channel of the chip and reduce the thermal resistance of the product.

Claims

1. A high-power laser module packaging method, characterized in that: The following steps are involved: Step 1, sandwich sintering: A sintered solder (7) is placed between a high-power laser chip (11) and an electrode (12), and a sintering process is used to sinter the chip (11) and the electrode (12), wherein the electrode (12) is located on both sides of the chip (11), thereby obtaining a sandwich (1) of electrode-chip-electrode sintering bonding; Step 2, first ceramic sheet welding: Connecting the electrode overlapping block (2) to two electrodes (12) of the sandwich (1), so that a plurality of sandwiches (1) with the electrode overlapping blocks (2) are arranged in sequence to form a row of sandwiches (1) with the electrode overlapping blocks (2); A welding process is used to weld a row of sandwiches (1) with electrode overlap blocks (2) and a first ceramic sheet (3); the electrode overlap blocks (2), the electrodes (12), and the chip (11) are all connected to the first ceramic sheet (3); and a welded assembly is formed in which a row of sandwiches (1) with electrode overlap blocks (2) and the first ceramic sheet (3) are combined together. Step 3, welding assembly installation: The welding assembly is mounted on the water flow block (4), with the sandwich (1) of the welding assembly being outside the water flow block (4); a waterproof gasket (5) is placed between the welding assembly and the water flow block (4), and during installation, the first ceramic sheet positioning hole (33), the waterproof gasket positioning hole (51), and the water flow block positioning hole (43) correspond to each other; Step 4, welding of the second ceramic sheet: Using a welding process, two second ceramic sheets (6) are respectively welded to two sides of a sandwich (1) with a row of electrode overlap blocks (2); the electrode overlap blocks (2), the electrodes (12), and the chip (11) are all connected to the second ceramic sheets (6); the second ceramic sheets (6) are perpendicular to the first ceramic sheets (3); Step 5, packaging: The wires are welded on the welding assembly, and the assembled welding assembly, the water-passing block (4), the waterproof gasket 6, the second ceramic sheet (6), and the wires are installed in a housing to obtain a high-power laser module.

2. The high-power laser module packaging method according to claim 1, characterized in that: In the step 1, the sintering process is carried out in a eutectic furnace.

3. The high-power laser module packaging method according to claim 1, characterized in that: In the step 1, the sintering solder (7) used in the sintering process is gold-tin solder, and the electrode (12) is a tungsten-copper electrode.

4. The high-power laser module packaging method according to claim 1, characterized in that: In step 2, the first ceramic sheet (3) is a heat dissipation fin, comprising a bottom surface (31) and fins (32); the bottom surface (31) is a welding surface, connected to the electrode bridging block (2), the electrode (12), and the chip (11); the fins (32) are formed by grooves for heat dissipation; The material of the first ceramic sheet (3) is aluminum nitride.

5. The high-power laser module packaging method according to claim 1, characterized in that: In step 2 and step 4, the welding process is solder welding, and the solder is tin-silver-copper solder.

6. A high-power laser module, characterized in that: It comprises a welding assembly, a water-passing block (4), two second ceramic sheets (6), a conductor, and a housing; The welding assembly, the water flow block (4), and the two second ceramic sheets (6) are located inside the outer shell; The welding assembly comprises a sandwich (1), an electrode overlapping block (2), and a first ceramic sheet (3); The electrode overlap block (2) is connected to the electrode (12) of the sandwich (1); a row of sandwiches (1) with the electrode overlap block (2) is welded and connected to the first ceramic sheet (3); The electrode overlapping block (2), the electrode (12), and the chip (11) are all connected to the first ceramic sheet (3); The sandwich (1) comprises a chip (11) and an electrode (12), wherein the electrode (12) is located on two sides of the chip (11), and the chip (11) and the electrode (12) are sintered and bonded; Two second ceramic sheets (6) are respectively welded to two sides of a sandwich (1) with a row of electrode overlap blocks (2); the electrode overlap blocks (2), the electrodes (12), and the chip (11) are all connected to the second ceramic sheets (6); the second ceramic sheets (6) are perpendicular to the first ceramic sheets (3); The wire is connected to the electrode (12) and is led out from the shell.

7. The high-power laser module according to claim 6, characterized in that: Also includes a waterproof gasket (5); The first ceramic sheet (3) is a heat dissipation fin, comprising a bottom surface (31) and fins (32); the bottom surface (31) is welded to a sandwich (1) with a row of electrode overlap blocks (2); the fins (32) are formed by grooves for heat dissipation; the first ceramic sheet (3) is provided with a first ceramic sheet positioning hole (33) for mounting and positioning the welding assembly on the water flow block (4); The water block (4) is used for heat dissipation of the first ceramic sheet (3), and is provided with a water inlet (41), a water outlet (42), and a water block positioning hole (43); the water inlet (41) and the water outlet (42) are used for the inlet and outlet of cooling water, and the water block positioning hole (43) is used for the installation of a welding assembly on the water block (4).

8. The high-power laser module according to claim 6 or 7, characterized in that: The waterproof gasket (5) is located between the welding assembly and the water flow block (4) and is used for sealing the welding assembly and the water flow block (4); the waterproof gasket (5) is provided with a waterproof gasket positioning hole (51) for installing and positioning the welding assembly on the water flow block (4).

9. The high-power laser module according to claim 6 or 7, characterized in that: The chip (11) is a high-power laser chip, and the electrode (12) is a tungsten-copper electrode; the sintering solder (7) used to sinter the chip (11) and the electrode (12) is a gold-tin solder; and the material of the first ceramic sheet (3) is aluminum nitride.

10. The high-power laser module according to claim 6 or 7, characterized in that: The sandwich (1) with a row of electrode overlapping blocks (2) is welded to the first ceramic sheet (3) and the second ceramic sheet (6), and the solder for the welding connection is tin-silver-copper solder.

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