Semiconductor laser surface electrogilding equipment and process thereof

Abstract

The invention relates to semiconductor laser surface electrogilding equipment and a process thereof, and relates to the technical field of semiconductor gilding, the equipment comprises a rack, a gold wire feeding device, a power supply module, an electrode shell and a feeding device, a nozzle is fixed in the electrode shell, and the electrode shell is provided with a nozzle used for forming a plasma area; an argon channel communicated with the nozzle is arranged in the electrode shell; the feeding device is used for placing a wafer, and the wafer is covered with a shielding plate. According to the method, a spraying mode is used for replacing traditional electroplating on the surface of the wafer, a gold layer with the thickness of several microns is formed on the surface of the wafer, the working mode is under the atmospheric condition, the surface is clean, the technological process is simple, liquid electroplating is not needed, and efficiency is improved; the spraying efficiency can be improved by improving the power supply power and the feeding speed at the same time. The mask plate and the wafer are very convenient to install, and the mask plate is automatically positioned through magnetic attraction, so that the efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor gold plating, and particularly relates to a semiconductor laser surface electroplating gold device and its process. Background Art

[0002] In the process of semiconductor laser chips, there is a process called P - surface plating, which is translated into electroplating in Chinese; the purpose is to form a gold layer with a thickness of about several micrometers in a specific area on the chip surface.

[0003] The process steps of traditional plating are: coating, developing, electroplating process, removing the glue, post - cleaning, drying, etc.

[0004] Regarding the above - mentioned related technologies, the inventor believes that the traditional plating process itself involves steps such as yellow light, wet process, electroplating, etc., which are relatively cumbersome. Electroplating uses special liquid medicine, and the monitoring of the liquid medicine concentration is required. The liquid medicine concentration is detected by a professional institution, and the use of materials is also relatively troublesome, with low efficiency. Summary of the Invention

[0005] The present application provides a semiconductor laser surface electroplating gold device and its process, which operates in an atmospheric environment, has a clean surface, a simple process, does not require liquid for electroplating, and improves efficiency.

[0006] The semiconductor laser surface electroplating gold device provided by the present application adopts the following technical solutions: A semiconductor laser surface electroplating gold device includes a frame, a gold wire feeding device, a power supply module, an electrode housing, and a feeding device. A nozzle is fixed inside the electrode housing. The electrode housing is provided with a nozzle for forming a plasma region, and an argon gas channel communicating with the nozzle is provided inside the electrode housing; the feeding device is used to place a wafer, and a mask plate is covered on the wafer.

[0007] By adopting the above - mentioned technical solutions, this working method works by forming local plasma under atmospheric conditions. High - pressure argon gas forms a stable air flow and forms plasma protection. The high - energy plasma melts the gold wire into a liquid state. The liquid - state gold is driven by the high - speed argon gas flow and sprayed on the surface of the wafer to be coated. The mask plate covers the parts of the wafer that do not need to be plated with gold.

[0008] Optionally, the gold wire feeding device includes a servo motor, a feeding wheel driven by the servo motor to rotate, and an auxiliary wheel rotatably connected to the frame. The feeding wheel and the auxiliary wheel clamp the gold wire.

[0009] By adopting the above - mentioned technical solutions, the servo motor drives the feeding wheel to rotate, and the auxiliary wheel rotates passively, thereby conveying the gold wire towards the nozzle direction, and the conveying speed of the gold wire is adjustable.

[0010] Optionally, the feeding device includes a conveyor belt mechanism. A soft magnetic ring is fixed on the inner belt surface of the conveyor belt mechanism. An iron ring is fixed at the bottom of the mask plate, and the diameter of the iron ring corresponds to that of the soft magnetic ring.

[0011] By adopting the above technical solution, after the mask plate is placed on the upper belt surface of the conveyor belt, the iron ring can be automatically positioned with the soft magnetic ring through magnetic attraction, and the stability of the mask plate on the conveyor belt is ensured.

[0012] Optionally, a positioning groove for wafer positioning is provided in the mask plate, and the positioning groove penetrates through the mask plate downward.

[0013] By adopting the above technical solution, the positioning of the mask plate and the wafer can be completed by covering the mask plate on the wafer, and the installation of the mask plate is simple and convenient.

[0014] Optionally, it further includes a testing device. The testing device includes a metal coil, a driving roller and a driven roller rotatably connected to the frame. The driving roller is driven to rotate by a second motor, and both ends of the metal coil are wound around the driving roller and the driven roller respectively.

[0015] By adopting the above technical solution, it is necessary to determine the ejection state and concentration of the gold material before formal spraying. During testing, the metal coil is first sprayed. As the metal coil moves, a long strip-shaped spraying trace is formed on the metal coil, and the operator observes whether the spraying trace is stable and whether the color depth meets the requirements.

[0016] Optionally, the metal coil is located beside the feeding device, and the top surface of the straightened metal coil is at the same height as the top surface of the wafer.

[0017] By adopting the above technical solution, through the position setting of the metal coil and spraying while the metal coil is moving, the formal spraying scenario is well simulated, which is convenient for the operator to determine the state of the gold material and reduce errors.

[0018] Optionally, a linear module is fixed on the frame, and the electrode shell is fixed on the sliding seat of the linear module.

[0019] By adopting the above technical solution, the electrode shell is driven to move by the linear module, so as to realize the switching movement of the spray nozzle above the metal coil and above the wafer.

[0020] In a second aspect, the present application provides a semiconductor laser surface gold plating process, adopting the following technical solution: A semiconductor laser surface gold plating process uses the above-mentioned semiconductor laser surface gold plating equipment, and includes the following steps: Step S1: Place the wafer to be sprayed on the feeding device, and align the invalid area with the nozzle first; Step S2: Cover the mask plate on the surface of the wafer, closely attach the mask plate to the wafer and fix the mask plate; Step S3: Turn on the argon gas, and the argon gas passes through the argon gas channel, so that the air pressure increases from small to large to the process requirement, and the pressure is selected from 0.2 MPa to 0.6 MPa; Step S4: Turn on the gold wire feeding device and the power supply module; Observe the state of the gold material under the nozzle and gradually increase the power until the process requirement is met; Step S5: Move the nozzle above the wafer and move the wafer uniformly for spraying operation; Step S6: After completing the gold plating spraying of the wafer, move the nozzle to the invalid area; Step S7: Turn off the power supply and turn off the argon gas supply; Step S7: Remove the mask plate and take away the wafer.

[0021] By adopting the above technical solution, through the above process, spraying is used to replace traditional electroplating on the surface of the wafer, and a gold layer with a thickness of several micrometers is formed on the surface of the wafer. This process operates in an atmospheric environment, with a clean surface, a simple process, no need for liquid electroplating, and improved efficiency.

[0022] Optionally, the gold wire feeding device and the power supply module are linked, and when the power supply power increases, the feeding speed increases.

[0023] By adopting the above technical solution, by simultaneously increasing the power supply power and the feeding speed, the spraying efficiency can be improved.

[0024] Optionally, a collection plate is fixed on the rack. The collection plate is located at the end of the conveyor belt mechanism and closely adheres to the upper belt surface of the conveyor belt. A material taking device for taking materials is provided between the electrode shell and the collection plate, and the material taking device is a manipulator or a pushing cylinder.

[0025] By adopting the above technical solution, generally, the automatic material taking of the wafer and the mask plate after spraying is realized by the material taking device, realizing automation. When the material taking device does not work, the wafer and the mask plate slide onto the collection plate for temporary storage. By adding a discharge position through the collection plate, it is convenient for inspection and centralized collection.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. Spraying is used to replace traditional electroplating on the surface of the wafer, and a gold layer with a thickness of several micrometers is formed on the surface of the wafer. This working method is under atmospheric conditions, with a clean surface, a simple process, no need for liquid electroplating, and improved efficiency; 2. By setting a metal coil as a test device, the formal spraying scenario is well simulated, which is convenient for personnel to determine the state of the gold material; 3. The installation of the mask plate and the wafer is very convenient, and the mask plate is automatically positioned by magnetic attraction, improving the efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of an embodiment; Figure 2 is a top view of a semiconductor laser surface gold plating device according to an embodiment; Figure 3 is a perspective view of the feeding device according to an embodiment; Figure 4 is a perspective view of the testing device and the linear module according to an embodiment.

[0028] Description of the reference numerals: 1. Gold wire feeding device; 2. Power supply module; 3. Electrode housing; 4. Feeding device; 31. Nozzle; 32. Spray port; 33. Argon gas channel; 5. Wafer; 51. Mask plate; 11. Servo motor; 12. Feeding wheel; 13. Auxiliary wheel; 41. Conveyor belt mechanism; 42. Soft magnetic ring; 52. Iron ring; 43. Pad; 53. Positioning groove; 6. Testing device; 61. Metal coil; 62. Driving roller; 63. Driven roller; 64. Second motor; 7. Linear module; 44. Collection plate; 8. Material taking device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following further describes the present application in detail with reference to the accompanying drawings.

[0030] Embodiment 1:

[0031] Referring to Figure 1 , this embodiment discloses a semiconductor laser surface gold plating device, including a frame, a gold wire feeding device 1, a power supply module 2, an electrode housing 3, and a feeding device 4. The frame serves as a reference frame fixed to the ground and does not move. A nozzle 31 is fixed inside the electrode housing 3. The nozzle 31 is made of alumina ceramic material and has a hollow structure, forming functions of good insulation, heat resistance, and smooth material supply. The electrode housing 3 is also called a ground electrode. The electrode housing 3 is grounded as the cathode. The electrode housing 3 is provided with a spray port 32 for forming a plasma region. An argon gas channel 33 communicating with the spray port 32 is provided inside the electrode housing 3. The argon gas channel 33 is used to connect high-pressure argon gas, so as to eject a high-speed air flow outward at the spray port 32. The feeding device 4 is used to place a wafer 5, and a mask plate 51 is covered on the wafer 5.

[0032] The gold wire feeding device 1 includes a servo motor 11, a feeding wheel 12 driven to rotate by the servo motor 11, and an auxiliary wheel 13 connected to the frame for rotation. The feeding wheel 12 and the auxiliary wheel 13 clamp the gold wire. The feeding wheel 12 is driven to rotate by the servo motor 11, and the auxiliary wheel 13 is driven, thereby conveying the gold wire toward the nozzle 31. The feeding wheel 12 is made of metal, and the power supply end of the power supply module 2 is in sliding contact with the feeding wheel 12. The power supply module 2 directly applies electricity to the feeding wheel 12, thereby electrifying the gold wire. It should be noted that the servo motor 11 and the feeding wheel 12 are connected by an insulator, and the auxiliary wheel 13 is also an insulator to prevent the voltage applied by the power supply module 2 from being transmitted to other objects.

[0033] Since the electrode shell 3 is grounded as a cathode, a large voltage is generated between the gold wire and the electrode shell 3 in the local space of the gold wire and the argon gas at the nozzle 32, forming a local plasma. Since the distance between the gold wire and the electrode shell 3 is very small, the range of the plasma is very small, and it is basically maintained near the gold wire. Such high-energy plasma will melt the gold wire into a liquid state, and the liquid gold will be sprayed on the surface of the wafer 5 to be coated under the drive of the high-speed argon gas flow. Subsequent gold wires are continuously transported to the plasma area to continuously replenish the gold that has been sprayed away, and the operation continues.

[0034] Reference Figure 2 and Figure 3 The feeding device 4 includes a conveyor belt mechanism 41, a soft magnetic ring 42 is fixed on the inner belt surface of the conveyor belt mechanism 41, and an iron ring 52 is fixed on the bottom of the mask plate 51. The diameter of the iron ring 52 corresponds to the soft magnetic ring 42. After the mask plate 51 is placed on the upper belt surface of the conveyor belt, the iron ring 52 can automatically position with the soft magnetic ring 42 through magnetic attraction, and ensure the stability of the mask plate 51 on the conveyor belt. It should be noted that the soft magnetic ring 42 is embedded in the interior of the conveyor belt for installation, and the soft magnetic ring 42 will not affect the bending operation of the conveyor belt. The rollers at both ends of the conveyor belt mechanism 41 are made of aluminum and will not attract the soft magnetic ring 42. The frame is fixed with a pad 43, which is located below the upper belt surface of the conveyor belt and contacts the conveyor belt, and the pad 43 is located directly below the electrode shell 3. The pad 43 is used to support the wafer 5 and the mask plate 51 during spraying to prevent the wafer 5 and the mask plate 51 from moving up and down. After the mask plates 51 are placed on the conveyor belt in sequence, the mask plates 51 adjacent to each other are just fitted together to prevent the sprayed gold material from falling onto the conveyor belt as much as possible.

[0035] Reference Figure 1, a positioning groove 53 for positioning the wafer 5 is provided inside the mask plate 51. The positioning groove 53 penetrates downward through the mask plate 51. The mask plate 51 masks the top surface edge of the wafer 5 and also masks the area on the wafer 5 that needs to be masked. With this structure, covering the mask plate 51 on the wafer 5 can complete the positioning of the mask plate 51 and the wafer 5. In addition, positioning is carried out by the convex structure on the inner wall of the mask plate 51 fitting with the surface shape of the wafer 5, avoiding relative rotation between the mask plate 51 and the wafer 5.

[0036] Refer to Figure 2 and Figure 4 , this device further includes a testing device 6. The testing device 6 includes a metal coil 61, a driving roller 62 rotatably connected to the frame, and a driven roller 63. The frame is fixed with a second motor 64, and the driving roller 62 is driven to rotate by the second motor 64. Both ends of the metal coil 61 are wound around the driving roller 62 and the driven roller 63 respectively. The metal coil 61 is located beside the feeding device 4, and the top surface of the straightened metal coil 61 is at the same height position as the top surface of the wafer 5.

[0037] A rotational resistance is provided between the rotating shaft of the driven roller 63 and the frame, thus preventing the driven roller 63 from rotating due to inertia. When the driving roller 62 winds up the metal coil 61, the driven roller 63 simultaneously releases the metal coil 61. The metal coil 61 between the driving roller 62 and the driven roller 63 is straightened and in a horizontal state. The metal coil 61 is located at a position close to the side wall of the belt surface of the conveyor belt structure.

[0038] The frame is fixed with a linear module 7, and the electrode shell 3 is fixed on the slide of the linear module 7. The slide of the linear module 7 and the electrode shell 3 are separated by an insulator. The linear module 7 drives the electrode shell 3 to move, and the motor shell can be moved to be directly above the conveyor belt mechanism 41 or directly above the metal coil 61 through the movement.

[0039] The metal coil 61 will not burn and can withstand high temperatures. The testing device 6 is used to supply gold material for spraying at the initial stage of spraying. By observing the state of the gold material on the metal coil 61 by personnel, it is determined whether to start spraying the wafer 5. When spraying on the metal coil 61, the driving roller 62 rotates to wind up the metal coil 61. As the metal coil 61 moves, a long strip-shaped spraying trace is formed on the metal coil 61. Personnel observe whether the spraying trace is stable and whether the color depth meets the requirements. The observation can be realized through a camera. When the sprayed gold material meets the requirements, the electrode shell 3 is moved by the linear module 7, and the spray nozzle 32 is moved directly above the wafer 5 for formal spraying.

[0040] Embodiment Two:

[0041] A semiconductor laser surface gold plating process uses a semiconductor laser surface gold plating device of Embodiment One, including the following steps: Step S1: Place the wafer 5 to be sprayed on the feeding device 4, and align the invalid area with the nozzle 31 first; the invalid area is the metal coil 61. Selection of gold wire: To ensure smooth feeding and stable atmospheric plasma, the diameter of the gold wire is selected to be 500 microns.

[0042] Step S2: Cover the mask plate 51 on the surface of the wafer 5, and the mask plate 51 is closely attached to the wafer 5 and fix the mask plate 51; position and fix the mask plate 51 through the magnetic attraction of the soft magnetic ring 42 and the iron ring 52.

[0043] Step S3: Turn on the argon gas, and the argon gas passes through the argon gas channel 33, so that the air pressure increases from small to large to the process requirement, and the pressure selection range is 0.2 MPa - 0.6 MPa.

[0044] Step S4: Turn on the gold wire feeding device 1 and the power supply module 2; observe the state of the gold material under the nozzle 31 (i.e., the state of the gold material on the metal coil 61). Initially, the power supply power is low, and the formed local plasma region is weak. Gradually increase the power until the process requirement is met. The power supply module 2 adopts a DC high-voltage power supply method or a DC pulsed high-voltage power supply method, with a power supply voltage of 10 kV - 20 kV; a DC pulse frequency of 12 kHz - 20 kHz; and a power supply power of 500 W - 2000 W.

[0045] The gold wire feeding device 1 and the power supply module 2 are linked. When the power supply power rises, the feeding speed increases (i.e., the rotation speed of the servo motor 11 increases). This linkage structure can be realized through the controller and will not be elaborated here. By simultaneously increasing the power supply power and the feeding speed, the spraying efficiency can be improved.

[0046] Step S5: Move the nozzle 31 above the wafer 5, and move the wafer 5 at a constant speed for spraying operation. The nozzle 31 and the electrode housing 3 move together, and the movement is realized by the linear module 7, and the movement of the wafer 5 is realized by the conveyor belt mechanism 41.

[0047] The frame is fixed with a collection plate 44. The collection plate 44 is located at the end of the conveyor belt mechanism 41 and is close to the upper belt surface of the conveyor belt. A material taking device 8 for taking materials is provided between the electrode housing 3 and the collection plate 44. The material taking device 8 is a manipulator or a pushing cylinder.

[0048] Generally, the material taking device 8 realizes the automatic material taking of the sprayed wafer 5 and the mask plate 51 to achieve automation. When the material taking device 8 does not work or fails, the wafer 5 and the mask plate 51 slide onto the collection plate 44 for temporary storage. During this process, the soft magnetic ring 42 moves away from the iron ring 52 along with the conveyor belt, thus canceling the magnetic attraction. The collection plate 44 adds a material discharging position, which is convenient for inspection and centralized collection.

[0049] Step S6: After the gold plating and spraying of the wafer 5 are completed, move the nozzle 31 to the invalid area, which is above the metal coil 61.

[0050] Step S7: Turn off the power supply and the argon gas supply.

[0051] Step S7: Remove the mask plate 51 and take away the wafer 5.

[0052] Through the above process, spraying is used to replace traditional electroplating on the surface of the wafer 5, and a gold layer with a thickness of several micrometers is formed on the surface of the wafer 5. This working method works by forming local plasma under atmospheric conditions, and high-pressure argon gas forms a stable airflow and forms plasma protection. This process operates in an atmospheric environment, with a clean surface, a simple process, no need for liquid electroplating, and improved efficiency.

[0053] By setting the metal coil 61 as the test device 6, the raw materials are easily obtained, and the metal coil 61 has a long length and can be used for a long time. The metal coil 61 is sprayed while moving, which well simulates the formal spraying scenario, facilitating personnel to determine the state of the gold material. The gold on the mask plate 51 and the gold on the metal coil 61 are also convenient for recycling.

[0054] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A semiconductor laser surface gold plating device, characterized in that: It includes a frame, a gold wire feeding device (1), a power supply module (2), an electrode housing (3), and a feeding device (4). A nozzle (31) is fixed inside the electrode housing (3). The electrode housing (3) is provided with a nozzle opening (32) for forming a plasma region. An argon gas channel (33) communicating with the nozzle opening (32) is provided inside the electrode housing (3). The feeding device (4) is used to place a wafer (5), and a mask plate (51) covers the wafer (5).

2. The surface gold plating device for a semiconductor laser according to claim 1, wherein: The gold wire feeding device (1) includes a servo motor (11), a feeding wheel (12) driven by the servo motor (11) to rotate, and an auxiliary wheel (13) rotatably connected to the frame. The feeding wheel (12) and the auxiliary wheel (13) clamp the gold wire.

3. A semiconductor laser surface gold plating device according to claim 1, characterized in that: The feeding device (4) includes a conveyor belt mechanism (41). A soft magnetic ring (42) is fixed on the inner belt surface of the conveyor belt mechanism (41). An iron ring (52) is fixed at the bottom of the mask plate (51). The diameter of the iron ring (52) corresponds to that of the soft magnetic ring (42).

4. A semiconductor laser surface gold plating device according to claim 1, characterized in that: A positioning groove (53) for positioning the wafer (5) is provided inside the mask plate (51), and the positioning groove (53) penetrates downward through the mask plate (51).

5. A semiconductor laser surface gold plating device according to claim 1, characterized in that: It further includes a testing device (6). The testing device (6) includes a metal coil (61), a driving roller (62) and a driven roller (63) rotatably connected to the frame. The driving roller (62) is driven to rotate by a second motor (64). Both ends of the metal coil (61) are wound around the driving roller (62) and the driven roller (63) respectively.

6. The surface gold plating device for a semiconductor laser according to claim 5, wherein: The metal coil (61) is located beside the feeding device (4). The top surface of the straightened metal coil (61) is at the same height position as the top surface of the wafer (5).

7. A semiconductor laser surface gold plating device according to claim 1, characterized in that: A linear module (7) is fixed on the frame, and the electrode housing (3) is fixed on the slide of the linear module (7).

8. A surface electroplating gold process for semiconductor lasers, characterized in that: Using a semiconductor laser surface gold plating device according to any one of claims 1 - 7, it includes the following steps: Step S1: Place the wafer (5) to be sprayed on the feeding device (4), and align the invalid area with the nozzle (31) first; Step S2: Cover the mask plate (51) on the surface of the wafer (5), make the mask plate (51) closely fit the wafer (5) and fix the mask plate (51); Step S3: Turn on the argon gas. The argon gas passes through the argon gas channel (33), so that the air pressure increases from small to large to the process requirement, and the pressure is selected from 0.2 MPa to 0.6 MPa; Step S4: Turn on the gold wire feeding device (1) and the power supply module (2); Observe the state of the gold material under the nozzle (31), and gradually increase the power until the process requirement is met; Step S5: Move the nozzle (31) above the wafer (5), and move the wafer (5) at a constant speed for spraying operation; Step S6: After completing the gold plating spraying of the wafer (5), move the nozzle (31) to the invalid area; Step S7: Turn off the power supply and turn off the argon gas supply; Step S7: Remove the mask plate (51) and take away the wafer (5).

9. The semiconductor laser surface gold plating process according to claim 8, wherein: The gold wire feeding device (1) and the power supply module (2) are linked. When the power supply power rises, the feeding speed increases.

10. The surface gold plating process of the semiconductor laser according to claim 8, characterized in that: The frame is fixed with a collecting plate (44). The collecting plate (44) is located at the end of the conveyor belt mechanism (41) and is in close contact with the upper belt surface of the conveyor belt. A material taking device (8) for taking materials is arranged between the electrode shell (3) and the collecting plate (44). The material taking device (8) is a manipulator or a pushing cylinder.

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