Nickel plating equipment and nickel plating method for semiconductor wafer

Abstract

The invention relates to the field of nickel plating, in particular to nickel plating equipment and a nickel plating method.The nickel plating equipment comprises a plating solution box used for containing plating solution and two guide rollers transversely rotating in the plating solution box, the two guide rollers are sleeved with a plurality of carrier tapes side by side, and a transverse frame is arranged at the upper end of the middle of the plating solution box; the transverse frame is connected with a plurality of limiting rails through a connecting frame, the limiting rails correspond to the carrier tapes one to one up and down, and a rail groove is formed in the lower end of each limiting rail; the method comprises the following steps: S1, adding a plating solution into a plating solution box; s2, the carrier tape is driven to rotate, and the disc-shaped semiconductor wafers are vertically arranged between the limiting track and the carrier tape in sequence, so that the disc-shaped semiconductor wafers can continuously roll from front to back along the limiting track in sequence; and S3, the nickel-plated semiconductor wafer is taken out behind the space between the limiting track and the carrier tape. The nickel plating device can solve the problem that continuous nickel plating processing cannot be carried out on a semiconductor wafer in a circular sheet shape.

Description

Technical Field

[0001] This invention relates to the field of nickel plating, and in particular to a nickel plating apparatus and method for semiconductor wafers. Background Technology

[0002] Semiconductor wafers are typically in the form of thin, circular wafers. They come in various diameters, commonly 4 inches, 6 inches, 8 inches, and 12 inches. Their thickness varies depending on the application, generally ranging from several hundred micrometers to one millimeter. To ensure excellent conductivity, reduce contact resistance, and isolate the semiconductor wafer from air, moisture, and corrosive substances, preventing oxidation or chemical damage to the internal circuitry and extending chip life, a uniform layer of nickel is usually deposited on the surface of the semiconductor wafer. Because of the circular, thin wafer shape, most existing nickel plating equipment cannot perform continuous nickel plating on these wafers, affecting plating efficiency. Summary of the Invention

[0003] To address the problem that existing technologies cannot perform continuous nickel plating on circular thin-film semiconductor wafers, this invention proposes a nickel plating apparatus and method for semiconductor wafers.

[0004] The present invention adopts the following technical solution: A nickel plating apparatus for semiconductor wafers includes a plating bath tank for holding plating solution and two guide rollers that rotate laterally within the plating bath tank. Multiple carrier belts are mounted side-by-side on the two guide rollers. A crossbeam is located at the upper center of the plating bath tank, and the crossbeam is connected to multiple limiting tracks via a connecting frame. Each limiting track corresponds one-to-one with a carrier belt, and each limiting track has a groove at its lower end. During nickel plating, circular semiconductor wafers to be plated are sequentially placed at the front end of the limiting tracks, thereby continuously rolling backward between the limiting tracks and the carrier belts, resulting in continuous nickel plating of the semiconductor wafers. Furthermore, the limiting tracks and carrier belts ensure that the semiconductor wafers roll vertically in the plating solution, guaranteeing complete and sufficient contact between the semiconductor wafer surface and the plating solution, and ensuring uniform deposition of the nickel metal layer. Preferably, the plating bath has cylindrical cavity shells on both the left and right sides, and a rotating screw frame is installed inside each cylindrical cavity shell. The rotating screw frame can push the plating bath towards the center of the plating bath, so that the plating bath in the plating bath flows towards the center, ensuring complete and sufficient contact between the semiconductor wafer surface and the plating bath. At the same time, it ensures the uniformity of the temperature, pH value and concentration of the plating bath in the plating bath, thereby ensuring the quality of nickel plating.

[0005] Preferably, the plating bath tank has rotating disks on both the left and right sides, and two cylindrical shells rotate at the eccentric points of the two rotating disks, with the two cylindrical shells being relatively staggered. This causes the position of the auger pushing the plating bath towards the center to constantly change, further improving the fluidity of the plating bath. By staggering the two cylindrical shells, the plating bath pushed by the two augers can be prevented from colliding and canceling each other out, instead forming a staggered flow cycle in the center, further improving the fluidity of the plating bath.

[0006] Preferably, the bottom plate at the lower end of the plating tank is provided with two bottom pipes, and the lower side of each of the two cylindrical cavity shells is provided with a side pipe. The bottom pipe and the side pipe on the same side are connected by a corrugated pipe. This allows each cylindrical cavity shell to form a large circulation flow of the plating solution, which, together with the small circulation formed by the relative staggered arrangement of the two cylindrical cavity shells, further improves the overall fluidity of the plating solution.

[0007] Preferably, the bottom plate of the plating tank is equipped with a rotating spiral fan; the fan blades can be tilted at an angle to push the plating solution towards the bottom pipe during rotation, ensuring the large-scale circulation of the plating solution.

[0008] Preferably, the connecting frame includes a horizontal plate fixed to the limiting track, with two slide rods vertically fixed on the horizontal plate. Both slide rods are slidably connected to the horizontal frame through the plate. An adjusting screw is rotatably mounted in the middle of the horizontal plate and is threadedly connected to the horizontal frame. Rotating the adjusting screw changes the distance between the limiting track and the carrier belt to accommodate nickel plating of circular semiconductor wafers of different diameters.

[0009] Preferably, the limiting track includes an inclined section and a horizontal section. The horizontal section is fixedly connected to the connecting frame, and both ends of the horizontal section are inclined upwards. Due to the upward inclination of the inclined sections, an opening structure is formed, which facilitates the placement of a circular semiconductor wafer between the limiting track and the carrier tape. At the same time, the opening at the rear end facilitates the removal of the nickel-plated semiconductor wafer.

[0010] Preferably, each carrier belt has two tensioning frames that slide through it at the bottom of the plating bath. Each tensioning frame has a tensioning wheel rotating at its upper end. A spring is provided between the lower end of the two tensioning frames and the bottom of the plating bath to pull the tensioning wheel downwards to tighten the carrier belt. This prevents the semiconductor wafer from contacting the plating bath during placement and removal, thus avoiding contamination of the plating bath. The spring force allows the tensioning wheel to pull downwards to tighten the carrier belt, ensuring that the circular semiconductor wafer is completely immersed in the plating bath.

[0011] Preferably, the carrier tape includes two edges and an elastically deformable middle tape, with the two edges respectively disposed on both sides of the middle tape. This forms a limiting position for the circular semiconductor wafer in contact with the middle tape, preventing the circular semiconductor wafer from rolling off the middle tape. Through its elastic deformation characteristics, it ensures that the circular semiconductor wafer stands stably between the middle tape and the limiting track.

[0012] A method for nickel plating on a semiconductor wafer, comprising: S1. Add the plating solution into the plating solution tank; S2. The transmission belt rotates, and the disc-shaped semiconductor wafers are vertically placed between the limiting track and the transmission belt in sequence, so that the disc-shaped semiconductor wafers can roll continuously from front to back along the limiting track in sequence. S3. Remove the nickel-plated semiconductor wafer from between the limiting track and the carrier belt.

[0013] The beneficial effects of this invention are as follows: 1. The circular semiconductor wafers to be nickel plated are placed sequentially at the front end of the limiting track, thereby forming a continuous rolling motion of the circular semiconductor wafers between the limiting track and the carrier tape, thus forming a continuous nickel plating process for the semiconductor wafers. 2. By using a limiting track and a carrier belt, the semiconductor wafer is rolled vertically in a single state in the plating solution, ensuring complete and sufficient contact between the semiconductor wafer surface and the plating solution, and ensuring uniform deposition of the nickel metal layer. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a nickel plating device for semiconductor wafers; Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure; Figure 3 This is a schematic diagram of the plating bath tank; Figure 4 This is a structural diagram of the guide roller, carrier belt, rotating disk, and cylindrical cavity shell; Figure 5 This is a schematic diagram of the guide roller, carrier belt, and tensioner structure; Figure 6 This is a schematic diagram of the cross-sectional structure of the carrier belt; Figure 7 This is a structural diagram of the guide roller, rotating disk, and cylindrical cavity shell; Figure 8 This is a structural diagram of the rotating disk, cylindrical cavity shell, side tube, and screw frame; Figure 9 It is a structural diagram of the limiting track, inclined section, horizontal section and track groove.

[0015] In the picture: 1. Plating bath tank; 2. Horizontal frame; 3. Bottom tube; 4. Guide roller; 5. Carrier belt; 501. Edge; 502. Middle belt; 6. Tensioning frame; 7. Tensioning wheel; 8. Spring; 9. Rotary disc; 10. Cylindrical cavity shell; 11. Side tube; 12. Spiral frame; 13. Limiting track; 1301. Inclined section; 1302. Horizontal section; 14. Track groove; 15. Horizontal plate; 16. Slide rod; 17. Adjusting screw; 18. Spiral fan. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] Reference Figure 1-9 A nickel plating apparatus for semiconductor wafers includes a plating solution tank 1 for holding plating solution, and two guide rollers 4 that rotate laterally inside the plating solution tank 1. Multiple carrier belts 5 are mounted side by side on the two guide rollers 4. A crossbeam 2 is provided at the upper middle part of the plating solution tank 1. The crossbeam 2 is connected to multiple limiting rails 13 through a connecting frame. The multiple limiting rails 13 correspond one-to-one with the multiple carrier belts 5. Each limiting rail 13 has a rail groove 14 at its lower end. During nickel plating, the plating solution is first added to the plating solution tank 1. In this embodiment, the height of the plating solution needs to submerge the carrier belt 5 and approach the limiting track 13. At the same time, the first motor installed on the side of the plating solution tank 1 is started to drive one of the guide rollers 4, thereby causing the carrier belt 5 to rotate. When rotating, the carrier belt 5 located above moves from front to back. Then, a circular semiconductor wafer is taken and vertically placed between the limiting track 13 and the corresponding carrier belt 5, so that the upper part of the circular semiconductor wafer is in contact with the upper wall of the track groove 14, and the lower part of the circular semiconductor wafer is in contact with the carrier belt 5. Then, it is kept in an upright state. At this time, most of the circular semiconductor wafer is in the plating solution. As the carrier belt 5 moves, the circular semiconductor wafer rolls backward along the track groove 14. During the rolling process, the entire surface of the circular semiconductor wafer is submerged in the plating solution, thereby enabling the surface of the semiconductor wafer to undergo a chemical reaction with the plating solution, so that the nickel metal layer is uniformly deposited on the surface of the semiconductor wafer. Finally, at the rear end of the limiting track 13, the nickel-plated semiconductor wafer is taken out, and the nickel plating is completed. When placing the circular semiconductor wafer, as the circular semiconductor wafer placed at the front end of the limiting track 13 rolls backward, the circular semiconductor wafers to be nickel plated can be placed sequentially at the front end of the limiting track 13. This forms a continuous backward rolling of the circular semiconductor wafers between the limiting track 13 and the carrier belt 5, forming a continuous nickel plating process for the semiconductor wafers. Moreover, by using the limiting track 13 and the carrier belt 5 to make the semiconductor wafer roll in the plating solution in a vertical single state, the complete and sufficient contact between the surface of the semiconductor wafer and the plating solution is ensured, and the uniform deposition of the nickel metal layer is guaranteed. By setting up multiple limiting tracks 13 and multiple carrier belts 5, multiple circular semiconductor wafers can be placed and nickel plated simultaneously, further improving the nickel plating efficiency. It should be noted that the plating bath 1 is equipped with a heating device to ensure the temperature of the plating bath, as well as a monitoring device for parameters such as pH value and concentration of the plating bath to ensure that the pH value and concentration of the plating bath are normal; the guide roller 4 is provided with multiple ring ridges to form an axial limit on the carrier belt 5, so as to avoid lateral deviation during the movement of the carrier belt 5 and affect the continuous rolling of the circular semiconductor wafer.

[0018] Furthermore, cylindrical cavity shells 10 are provided on both the left and right sides of the plating tank 1, and a screw frame 12 rotates inside each of the two cylindrical cavity shells 10. The second motor installed on the outside of the cylindrical cavity shell 10 drives the screw frame 12. The rotating screw frame 12 can push the plating solution towards the middle of the plating solution tank 1, so that the plating solution in the plating solution tank 1 flows towards the middle, that is, towards the semiconductor wafer. This further ensures that the surface of the semiconductor wafer is in complete and sufficient contact with the plating solution. At the same time, it forms agitation of the plating solution in the plating solution tank 1, ensuring the uniformity of the temperature, pH value and concentration of the plating solution in the plating solution tank 1, thereby ensuring the quality of nickel plating.

[0019] Furthermore, the plating tank 1 has rotating disks 9 on both the left and right sides, and two cylindrical cavity shells 10 rotate at the eccentric points of the two rotating disks 9, and the two cylindrical cavity shells 10 are relatively staggered.

[0020] The two rotating disks 9 are connected to the drive wheels at both ends of the driven guide roller 4 via belt or chain drive. When the guide roller 4 rotates, it can drive the two rotating disks 9 to rotate, which in turn drives the cylindrical cavity shell 10 to rotate eccentrically. This ensures that the position of the cylindrical cavity shell 10 always rotates around the center of the rotating disk 9, and the position of the screw frame 12 pushing the plating solution towards the center is constantly changing, which further improves the fluidity of the plating solution and further ensures the quality of nickel plating. Moreover, by setting the two cylindrical cavity shells 10 relatively staggered, the plating solution pushed by the two screw frames 12 can be prevented from colliding and canceling each other out. Instead, a staggered flow cycle is formed in the middle, which further improves the fluidity of the plating solution.

[0021] Furthermore, the bottom plate at the lower end of the plating tank 1 is provided with two bottom pipes 3, and the lower side of the two cylindrical cavity shells 10 is provided with side pipes 11. The bottom pipes 3 and side pipes 11 on the same side are connected by a corrugated pipe. The connection between the bottom pipe 3, the side pipe 11, and the bellows allows the outer side of the cylindrical cavity shell 10 to be connected to the lower part of the plating solution tank 1. As the screw frame 12 rotates and pushes the plating solution inside the cylindrical cavity shell 10 toward the center, the plating solution located at the lower part of the plating solution tank 1 will replenish the plating solution inside the cylindrical cavity shell 10 through the bottom pipe 3, the bellows, and the side pipe 11. This allows each cylindrical cavity shell 10 to form a large circulation of plating solution, which, combined with the small circulation formed by the relative staggered arrangement of the two cylindrical cavity shells 10, further enhances the overall fluidity of the plating solution.

[0022] Furthermore, a spiral fan 18 is mounted on the bottom plate of the plating tank 1; The third motor drives the spiral fan 18 at the lower end of the plating solution tank 1. By adjusting the tilt angle of the fan blades, the plating solution is pushed to flow towards the bottom pipe 3 during rotation, ensuring the large-scale circulation of the plating solution.

[0023] Reference Figure 9 The connecting frame includes a horizontal plate 15 fixed to the limiting rail 13. Two sliding rods 16 are vertically fixed on the horizontal plate 15. Both sliding rods 16 are slidably connected to the horizontal frame 2. An adjusting screw 17 is rotatably mounted in the middle of the horizontal plate 15. The adjusting screw 17 is threadedly connected to the horizontal frame 2.

[0024] Since circular semiconductor wafers come in different diameters, when dealing with circular semiconductor wafers of different sizes, the adjusting screw 17 can be rotated. Through the threaded engagement between the adjusting screw 17 and the crossbeam 2, the adjusting screw 17 moves axially on the crossbeam 2, thereby driving the cross plate 15 to rise and fall, and then driving multiple limit rails 13 to rise and fall, thereby changing the distance between the limit rails 13 and the carrier belt 5, so as to adapt to the nickel plating of circular semiconductor wafers of different diameters.

[0025] Furthermore, the limiting track 13 includes an inclined section 1301 and a horizontal section 1302. The horizontal section 1302 is fixedly connected to the connecting frame, and the front and rear ends of the horizontal section 1302 are both inclined upwards and formed with inclined sections 1301.

[0026] With the tilted section 1301 and the horizontal section 1302, when placing a circular semiconductor wafer, the tilted section 1301 is tilted upward to form an opening structure, which facilitates the placement of the circular semiconductor wafer between the limiting track 13 and the carrier belt 5 through this opening. At the same time, the opening at the rear end facilitates the removal of the nickel-plated semiconductor wafer.

[0027] Reference Figure 2 and 5 Each of the carrier belts 5 has two tensioning frames 6 that slide through the bottom plate of the plating tank 1 at the lower end of the carrier belt 5. Each of the two tensioning frames 6 has a tensioning wheel 7 that rotates at the upper end. A spring 8 is provided between the lower end of the two tensioning frames 6 and the bottom plate of the plating tank 1, so that the tensioning wheel 7 pulls the carrier belt 5 downward. To further facilitate the placement and removal of semiconductor wafers, in this embodiment, when adding plating solution to the plating tank 1, the surface of the plating solution can be made level with the upper surface of the carrier belt 5. Then, the adjusting screw 17 is rotated to control the limiting track 13 to descend until the lower end of the horizontal section 1302 contacts the upper end of the carrier belt 5. Then, the circular semiconductor wafer is placed at the opening of the inclined section 1301. As the carrier belt 5 rotates, the circular semiconductor wafer rolls from the inclined section 1301 to the horizontal section 1302, thereby squeezing the carrier belt 5 to move downward. This allows the circular semiconductor wafer to be completely immersed in the plating solution when it rolls to the horizontal section 1302, and rolls out of the plating solution when it rolls to the inclined section 1301 at the rear end. This avoids contact between the semiconductor wafer and the plating solution during placement and removal, thus preventing contamination of the plating solution. The tensioning wheel 7 is pulled downward by the elastic force of the spring 8 to form the carrier belt 5. When the circular semiconductor wafer is squeezed above the carrier belt 5, the lower end of the carrier belt 5 can overcome the elastic force of the spring 8 and move upward, ensuring that the circular semiconductor wafer can be completely immersed in the plating solution.

[0028] Reference Figure 6 The carrier belt 5 includes two edge edges 501 and a middle belt 502 capable of elastic deformation, with the two edge edges 501 respectively disposed on both sides of the middle belt 502.

[0029] The two edges 501 form a limit for the circular semiconductor wafer that contacts the middle strip 502, preventing the circular semiconductor wafer from rolling off the middle strip 502. At the same time, the elastic deformation of the middle strip 502 ensures that the circular semiconductor wafer is stably upright between the middle strip 502 and the limit track 13 when the middle strip 502 is engaged with the limit track 13.

[0030] Reference Figure 1-9 A method for nickel plating on a semiconductor wafer, comprising: S1. Add the plating solution into plating solution tank 1; S2. The drive guide roller 4 rotates, and then the carrier belt 5 rotates, sequentially placing the disc-shaped semiconductor wafer vertically between the limiting track 13 and the carrier belt 5, so that the upper part of the circular semiconductor wafer is in contact with the upper wall of the track groove 14, and the lower part of the circular semiconductor wafer is in contact with the carrier belt 5, so that the disc-shaped semiconductor wafer can roll continuously from front to back along the limiting track 13. During the rolling process, the entire surface of the circular semiconductor wafer will be immersed in the plating solution, thereby enabling the semiconductor wafer surface to undergo a chemical reaction with the plating solution, so that the nickel metal layer is uniformly deposited on the semiconductor wafer surface. S3. The nickel-plated semiconductor wafer is removed from the rear between the limiting track 13 and the carrier belt 5.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A nickel plating apparatus for semiconductor wafers, characterized in that, It includes a plating solution tank (1) for holding plating solution, and two guide rollers (4) that rotate laterally in the plating solution tank (1). Multiple carrier belts (5) are mounted side by side on the two guide rollers (4). A cross frame (2) is provided at the upper middle part of the plating solution tank (1). Multiple limiting rails (13) are connected to the cross frame (2) through a connecting frame. The multiple limiting rails (13) correspond one-to-one with the multiple carrier belts (5). Each limiting rail (13) has a track groove (14) at its lower end.

2. The nickel plating equipment for semiconductor wafers according to claim 1, characterized in that, The plating tank (1) is provided with cylindrical cavity shells (10) on both the left and right sides, and a screw frame (12) rotates inside each of the two cylindrical cavity shells (10).

3. The nickel plating equipment for semiconductor wafers according to claim 2, characterized in that, The plating tank (1) has rotating disks (9) on both the left and right sides. Two cylindrical cavity shells (10) rotate at the eccentric points of the two rotating disks (9) respectively, and the two cylindrical cavity shells (10) are relatively misaligned.

4. A nickel plating apparatus for semiconductor wafers according to claim 2 or 3, characterized in that, The plating tank (1) has two bottom tubes (3) on the bottom plate at the lower end, and two side tubes (11) are provided on the lower side of the two cylindrical cavity shells (10). The bottom tubes (3) and side tubes (11) on the same side are connected by a corrugated pipe.

5. The nickel plating equipment for semiconductor wafers according to claim 1, characterized in that, A spiral fan (18) rotates at the bottom plate of the plating tank (1).

6. The nickel plating equipment for semiconductor wafers according to claim 1, characterized in that, The connecting frame includes a horizontal plate (15) fixed to the limiting rail (13). Two sliding rods (16) are vertically fixed on the horizontal plate (15). Both sliding rods (16) are slidably connected to the horizontal frame (2). An adjusting screw (17) is rotatably mounted in the middle of the horizontal plate (15). The adjusting screw (17) is threadedly connected to the horizontal frame (2).

7. The nickel plating equipment for semiconductor wafers according to claim 6, characterized in that, The limiting track (13) includes an inclined section (1301) and a horizontal section (1302). The horizontal section (1302) is fixedly connected to the connecting frame. Both the front and rear ends of the horizontal section (1302) are inclined sections (1301) formed upwards.

8. The nickel plating equipment for semiconductor wafers according to claim 7, characterized in that, Each carrier belt (5) has two tensioning frames (6) sliding through the bottom plate of the plating tank (1) at its lower end. Each tensioning frame (6) has a tensioning wheel (7) rotating at its upper end. A spring (8) is provided between the lower end of the two tensioning frames (6) and the bottom plate of the plating tank (1) to pull the tensioning wheel (7) downward to tighten the carrier belt (5).

9. The nickel plating equipment for semiconductor wafers according to claim 1, characterized in that, The carrier belt (5) includes two edge edges (501) and a middle belt (502) capable of elastic deformation, with the two edge edges (501) respectively disposed on both sides of the middle belt (502).

10. A method for nickel plating on a semiconductor wafer, characterized in that, include S1. Add the plating solution into the plating solution tank (1); S2, the transmission belt (5) rotates, and the disc-shaped semiconductor wafers are placed vertically between the limiting track (13) and the transmission belt (5) in sequence, so that the disc-shaped semiconductor wafers can roll continuously from front to back along the limiting track (13); S3. The nickel-plated semiconductor wafer is removed from the rear between the limiting track (13) and the carrier belt (5).

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