Acid tank structure for chained BSG removing machine table and use method of acid tank structure

Abstract

The invention discloses an acid tank structure for a chained BSG removing machine and a using method, and relates to the technical field of silicon wafer cleaning, the acid tank structure comprises a roller, the bottom of the roller is provided with a first water film area, a first acid tank, a second water film area, a second acid tank, a water tank and a drying tank, and overflow areas are arranged between the tank bodies. The overflow area comprises a first overflow groove, a second front overflow groove, a second rear overflow groove, a third front overflow groove and a third rear overflow groove, water guide assemblies are arranged in the second front overflow groove and the second rear overflow groove, and each water guide assembly comprises a trapezoidal support and a straight acrylic plate; the trapezoidal brackets are symmetrically arranged on the two sides of the second acid tank and are fixed in the corresponding overflow tanks, and the straight acrylic plates are fixed on the trapezoidal brackets and are obliquely arranged. According to the invention, only the specific overflow tank needs to be locally modified, the mounting operation can be carried out only by dismounting the rollers in the overflow area, the modified structure is made of an acrylic material, large expenditure is not generated, and the dilution degree of the solution in the acid tank can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon wafer cleaning, and particularly relates to an acid tank structure for a chain BSG removal machine and a use method. BACKGROUND

[0002] The basic structure of the chain BSG removal machine is: water film -> acid tank 1 -> water film -> acid tank 2 -> water tank -> discharging, there is an overflow area between each tank body, a roller is arranged on the tank body, and the silicon wafer is conveyed from the feeding area to the discharging area through the self-rotation of the roller, one third to one half of the roller in the acid tank and the water tank is immersed in the liquid, the roller structure between the area is lubricated by the liquid, and the operation is stable, and the roller structure in the overflow area between the tank bodies is suspended and does not contact the liquid, and the long-term dry grinding will cause wear and deformation, the out-of-round roller will shake abnormally when rotating, and then the silicon wafer will shake when passing through, so that the water film on the surface of the silicon wafer will fall off under the shaking, if the water falls into the acid tank overflow area at this time, the water will enter the acid tank overflow area, thereby diluting the acid tank solution, in order to ensure the cleaning effect, more acid must be supplemented to maintain the concentration, thereby increasing the consumption of acid, in addition, if the water entering the tank body is not fully mixed and uniform, the solution concentration in the partial area will be low, and the cleaning effect of the silicon wafer in the area will be affected.

[0003] Based on this, the acid tank structure for the chain BSG removal machine and the use method can eliminate the disadvantages of the prior art. SUMMARY

[0004] The purpose of the present application is to provide an acid tank structure for a chain BSG removal machine and a use method to solve the problem that the falling water in the background art will affect the concentration of the acid tank solution and the water that is not fully mixed and uniform will affect the cleaning effect of the silicon wafer.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: An acid tank structure for a chain BSG removal machine, comprising a roller for conveying a silicon wafer body, a first water film area, a first acid tank, a second water film area, a second acid tank, a water tank and a drying tank are sequentially arranged on the bottom of the roller along the advancing direction of the silicon wafer body, an overflow area is arranged between each tank body, the overflow area comprises a first overflow tank, a second front overflow tank, a second rear overflow tank, a third front overflow tank and a third rear overflow tank which are sequentially arranged along the advancing direction of the silicon wafer body, the second front overflow tank is located between the second water film area and the second acid tank, the second rear overflow tank and the third front overflow tank are located between the second water film area and the second acid tank, the third rear overflow tank is located between the water tank and the drying tank, the first overflow tank is located between the first acid tank and the water film area, and a water guide assembly for water saving and flow guiding is arranged in the second front overflow tank and the second rear overflow tank. The water guiding component includes a trapezoidal bracket and a flat acrylic plate. The trapezoidal bracket is symmetrically arranged on both sides of the second acid tank and fixed inside the corresponding overflow tank. The flat acrylic plate is fixed on the trapezoidal bracket and is inclined. The inclined direction is downward from the second acid tank to the water tank or the second water film area.

[0006] Preferably, the trapezoidal bracket is welded to the bottom of the second front overflow trough and the second rear overflow trough, and the flat acrylic plate is detachably mounted on the trapezoidal bracket by a number of screws.

[0007] Preferably, the side of the flat acrylic plate away from the second acid tank extends to the edge of the corresponding overflow tank, and the side of the flat acrylic plate near the second acid tank is completely separated from the edge of the second acid tank. The bottom of each overflow tank is provided with a conveying channel connected to the corresponding tank body.

[0008] Preferably, the first water film area and the second water film area are provided with pure water nozzles, which are used to spray pure water onto the surface of the silicon wafer to form a water film to protect the front side of the silicon wafer and prevent it from being corroded by hydrofluoric acid solution.

[0009] Preferably, the drying tank is equipped with a heating fan, which is used to generate hot air and dry the moisture on the surface of the silicon wafer after cleaning.

[0010] A method for using an acid tank structure for a chain-type BSG removal machine includes the following steps: Step S1: The silicon wafer body passes through the first water film area, the first acid tank, the second water film area, the second acid tank, the water tank and the drying tank in sequence along the forward direction to complete the BSG removal, cleaning and drying process; Step S2: During the transfer of the silicon wafer body, the water droplets generated by the rotation of the roller in the overflow area fall onto the flat acrylic plate of the water guiding component. Through the inclined guiding effect of the flat acrylic plate, the water droplets on the surface of the silicon wafer body are guided to the second water film area or the inside of the water tank.

[0011] Preferably, before step S1, a modification step for the overflow area is included, which specifically includes the following steps: Step 1: Customize several rectangular flat acrylic sheets and several trapezoidal supports; Step 2: Empty all tanks and overflow tanks, and clean the inside of the tanks, overflow tanks and rollers to ensure that there is no hydrofluoric acid solution residue in the tanks and overflow tanks. Step 3: Remove the rollers from the overflow area and place them flat on one side according to their different positions in the overflow area to avoid deformation. Step 4: Wipe the inside of the overflow tank and use a welding torch to weld the trapezoidal bracket into the corresponding overflow tank, with the inclined side of the trapezoidal bracket facing upwards towards the side of the second acid tank. Step 5: Install the flat acrylic sheet onto the surface of the trapezoidal bracket with several screws, so that one side of the flat acrylic sheet is separated from the second acid tank and the other side extends to the outside of the overflow tank. Step 6: Reinstall the rollers one by one according to the different locations of the overflow area; Step 7: Prepare hydrofluoric acid solution according to the ratio and resume production operation.

[0012] Preferably, the thickness of the flat acrylic sheet in step 1 is 1cm, the length is 120cm, and the width is 20cm.

[0013] Preferably, the rollers located at the top of the first acid tank and the second acid tank are both provided with threads, and the rollers are immersed in hydrofluoric acid solution according to a preset ratio, the preset ratio being 1 / 3 to 1 / 2.

[0014] Preferably, the concentration of hydrofluoric acid solution in the first acid tank is higher than the concentration of hydrofluoric acid solution in the second acid tank.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides an acid tank structure for a chain-type BSG removal machine. Only a partial modification to a specific overflow tank is required. The main operations are limited to disassembling and installing rollers and adding water guiding components. No modification to the main machine frame is necessary; installation can be performed simply by removing the rollers from the overflow area and reinstalling them after installation. The modified structure is made of acrylic, minimizing costs and improving the dilution of the acid tank solution by dripping water, reducing the probability of water falling into the acid tank, and thus improving the cleaning effect of the chain-type BSG removal machine. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the acid tank structure of the present invention.

[0017] Figure 2 For the present invention Figure 1 A schematic diagram of point A in the middle.

[0018] Figure 3 This is a schematic diagram illustrating the steps of the method of using the present invention.

[0019] Figure 4 This is a schematic diagram of the modification steps of the present invention.

[0020] Figure 5 This is a schematic diagram illustrating the trend of hydrofluoric acid BOM in this invention.

[0021] Figure reference numerals: 1. Silicon wafer body; 2. Roller; 3. First water film area; 4. First acid tank; 5. Second water film area; 6. Second acid tank; 7. Water tank; 8. Drying tank; 9. First overflow tank; 10. Second front overflow tank; 11. Second rear overflow tank; 12. Third front overflow tank; 13. Third rear overflow tank; 14. Trapezoidal support; 15. Flat acrylic plate; 16. Conveying channel. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Example 1 In this embodiment, as Figure 1 and Figure 2 As shown, an acid tank structure for a chain-type BSG removal machine includes rollers 2 for conveying silicon wafer bodies 1. The bottom of the rollers 2, along the forward direction of the silicon wafer body 1, is sequentially arranged with a first water film zone 3, a first acid tank 4, a second water film zone 5, a second acid tank 6, a water tank 7, and a drying tank 8. The water tank 7 ensures that the surface of the silicon wafer body 1 is clean and residue-free after discharge. The drying tank 8 ensures that the surface of the silicon wafer body 1 is dry after discharge. Each tank has an overflow area, which is a transition area connecting adjacent process tanks, used to collect and guide liquid that may overflow / splash from the tank or the silicon wafer surface. The overflow area includes sections arranged along the forward direction of the silicon wafer body 1. The system consists of a first overflow trough 9, a second front overflow trough 10, a second rear overflow trough 11, a third front overflow trough 12, and a third rear overflow trough 13. The second front overflow trough 10 is located between the second water film area 5 and the second acid tank 6. The second rear overflow trough 11 and the third front overflow trough 12 are located between the second water film area 5 and the second acid tank 6. The third rear overflow trough 13 is located between the water tank 7 and the drying tank 8. The first overflow trough 9 is located between the first acid tank 4 and the water film area. The interior of the second front overflow trough 10 and the second rear overflow trough 11 is equipped with a water guiding component for water conservation and flow guidance. The water guiding component is located in the two overflow troughs in front and behind the second acid tank 6 along the transmission direction of the silicon wafer body 1. The water guiding assembly includes a trapezoidal bracket 14 and a flat acrylic plate 15, wherein the trapezoidal bracket 14 and the flat acrylic plate 15 are... Figure 2 In the red area, trapezoidal brackets 14 are symmetrically arranged on both sides of the second acid tank 6 and fixed inside the corresponding overflow tank. Flat acrylic plate 15 is fixed on trapezoidal brackets 14 and is inclined. The inclined direction is downward from the second acid tank 6 to the water tank 7 or the second water film area 5. Flat acrylic plate 15 does not contact the roller 2, but is placed below the roller 2, which plays the role of saving water and guiding flow. Among them, such as Figure 1 and Figure 2As shown, the trapezoidal bracket 14 is welded to the bottom of the second front overflow channel 10 and the second rear overflow channel 11. The flat acrylic plate 15 is detachably installed on the trapezoidal bracket 14 by several screws, so that the entire flat acrylic plate 15 is in an inclined state. Among them, such as Figure 1 and Figure 2 As shown, the side of the flat acrylic plate 15 away from the second acid tank 6 extends to the edge of the corresponding overflow tank, guiding water droplets on the surface of the silicon wafer body 1 to the second water film area 5 or the interior of the water tank 7. The side of the flat acrylic plate 15 near the second acid tank 6 is completely separated from the edge of the second acid tank 6 to prevent the acid solution from being guided out. The bottom of the overflow tank is provided with a conveying channel 16 connected to the corresponding tank body. When water droplets fall, they are directly blocked by the flat acrylic plate 15 and flow into the second water film area 5 or the interior of the water tank 7 along the slope, instead of falling into the second acid tank 6, thus avoiding dilution of the solution. In this embodiment, a pure water nozzle is provided in the first water film area 3 and the second water film area 5. The pure water nozzle is used to spray pure water onto the surface of the silicon wafer body 1 to form a water film to protect the front side of the silicon wafer body 1 and prevent it from being corroded by hydrofluoric acid solution. The water film is a layer of pure water that covers the surface of the silicon wafer body 1 after it is sprayed by the pure water nozzle. In this embodiment, a heating fan is provided in the drying tank 8. The heating fan is used to generate hot air and dry the moisture on the surface of the silicon wafer body 1 after cleaning. Example 2 The difference from Example 1 is that, as in Example 1, Figures 3-5 As shown, the present invention also provides a method for using an acid tank structure for a chain-type BSG removal machine, specifically including the following steps: Step S1: The silicon wafer body 1 passes through the first water film area 3, the first acid tank 4, the second water film area 5, the second acid tank 6, the water tank 7 and the drying tank 8 in sequence along the forward direction to complete the BSG removal, cleaning and drying process. Specifically: Step 1: The silicon wafer body 1 passes through the pure water nozzle of the first water film zone 3, and a layer of water film is covered on the surface of the silicon wafer body 1. Step 2: The first acid tank 4 contains hydrofluoric acid solution, and the threaded roller 2 is half-submerged in the acid solution to achieve the effect of removing BSG. Step 3: The silicon wafer body 1 passes through the pure water nozzle of the second water film zone 5, and the pure water nozzle replenishes the water film of the silicon wafer body 1. Step 4: The second acid tank 6 contains hydrofluoric acid solution, and the secondary reaction ensures the BSG removal effect; Step 5: Water tank 7 cleans the surface of the silicon wafer body 1 after the acid pickling reaction; Step 6: The drying tank 8 dries the surface moisture of the cleaned silicon wafer body 1 under the action of hot air; Step S2: During the transfer of the silicon wafer body 1, the water droplets generated by the rotation of the roller 2 located in the overflow area fall onto the flat acrylic plate 15 of the water guiding component. Through the inclined guiding effect of the flat acrylic plate 15, the water droplets on the surface of the silicon wafer body 1 are guided to the second water film area 5 or the inside of the water tank 7. Among them, such as Figure 4 As shown, before step S1, there is also a modification step for the overflow area, which specifically includes the following steps: Step 1: Customize several rectangular flat acrylic sheets 15 and several trapezoidal supports 14. The flat acrylic sheets 15 in this step are 1cm thick, 120cm long, and 20cm wide. The tilt angle of the flat acrylic sheets 15 is designed to ensure that water droplets can slide off their surface quickly, and the tilt direction is directed towards the liquid surface or internal space of the second water film area 5 or the water tank 7 to achieve effective flow guidance. Step 2: Empty all tanks and overflow tanks, and clean the inside of the tanks, overflow tanks and rollers 2 to ensure that there is no hydrofluoric acid solution residue in the tanks and overflow tanks. Step 3: Remove roller 2 from the overflow area and place roller 2 flat on one side according to the different positions of the overflow area to avoid deformation of roller 2; Step 4: Wipe the inside of the overflow tank and use a welding torch to weld the trapezoidal bracket 14 into the corresponding overflow tank, with the inclined side of the trapezoidal bracket 14 facing upward towards the side of the second acid tank 6. Step 5: Install the flat acrylic plate 15 onto the surface of the trapezoidal bracket 14 with several screws, so that one side of the flat acrylic plate 15 is separated from the second acid tank 6, and the other side extends to the outside of the overflow tank. Step 6: Install rollers 2 back in sequence according to the different locations of the overflow area; Step 7: Prepare hydrofluoric acid solution according to the specified ratio and resume production operation; In this embodiment, the rollers 2 located at the top of the first acid tank 4 and the second acid tank 6 are both provided with threads, and the rollers 2 are immersed in the hydrofluoric acid solution according to a preset ratio of 1 / 3 to 1 / 2. The concentration of the hydrofluoric acid solution in the first acid tank 4 is higher than the concentration of the hydrofluoric acid solution in the second acid tank 6. Specifically, in the prior art, the dry grinding and shaking of the roller 2 causing water droplets to splash and dilute the acid solution is a specific problem that has long been neglected or not effectively solved. However, the present invention uses a low-cost flat acrylic plate 15 to guide the water droplets away from the second acid tank 6, reducing the amount of acid replenishment and lowering the risk of uneven concentration. Comparative Example 1 The difference between this comparative example and Examples 1 and 2 is that this comparative example is a process flow of conventional technology, specifically including: the silicon wafer body 1 passes through the first water film area 3, the first acid tank 4, the second water film area 5, the second acid tank 6, the water tank 7 and the drying tank 8 in sequence along the forward direction to complete the BSG removal, cleaning and drying process. Compared to Example 2, this comparative example did not perform step S2, and the chain-type BSG removal machine did not undergo any modification to the water guiding component. The specific effects before and after the improvement are as follows: Figure 5 The figure shows a comparison of the hydrofluoric acid consumption trend per 10,000 silicon wafers before and after the application of this invention (the modification period is from the beginning of May to the end of June). The specific hydrofluoric acid consumption is shown in the figure. It can be clearly seen from the figure that the hydrofluoric acid consumption has decreased significantly, which indicates that this invention has an improved effect and has good application prospects.

[0024] In summary, the acid tank structure and usage method of the chain-type BSG removal machine provided by the present invention effectively intercepts and guides water droplets splashed from the surface of the silicon wafer body 1 due to the vibration of the roller 2 by setting an inclined acrylic guide plate in the overflow tank adjacent to the second acid tank 6, preventing them from entering the dilution solution of the second acid tank 6. The above method has a simple structure, low modification cost, and is easy to implement, which facilitates the reduction of hydrofluoric acid consumption, improves the stability of acid tank solution concentration, and thus achieves the purpose of improving the silicon wafer cleaning effect.

[0025] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An acid tank structure for a chain-type BSG removal machine, characterized in that, The system includes rollers (2) for conveying the silicon wafer body (1). The bottom of the rollers (2) is sequentially provided with a first water film area (3), a first acid tank (4), a second water film area (5), a second acid tank (6), a water tank (7), and a drying tank (8) along the forward direction of the silicon wafer body (1). Each tank has an overflow area, which includes a first overflow trough (9), a second front overflow trough (10), a second rear overflow trough (11), a third front overflow trough (12), and a third rear overflow trough, all sequentially arranged along the forward direction of the silicon wafer body (1). The second front overflow trough (10) is located between the second water film area (5) and the second acid tank (6), the second rear overflow trough (11) and the third front overflow trough (12) are located between the second water film area (5) and the second acid tank (6), the third rear overflow trough (13) is located between the water tank (7) and the drying tank (8), the first overflow trough (9) is located between the first acid tank (4) and the water film area, and the interior of the second front overflow trough (10) and the second rear overflow trough (11) is provided with water guiding components for water saving and guiding; The water guiding component includes a trapezoidal bracket (14) and a flat acrylic plate (15). The trapezoidal bracket (14) is symmetrically arranged on both sides of the second acid tank (6) and fixed inside the corresponding overflow tank. The flat acrylic plate (15) is fixed on the trapezoidal bracket (14) and is inclined. The inclined direction is downward from the second acid tank (6) towards the water tank (7) or the second water film area (5).

2. The acid tank structure for a chain-type BSG removal machine according to claim 1, characterized in that, The trapezoidal bracket (14) is welded to the bottom of the second front overflow trough (10) and the second rear overflow trough (11), and the flat acrylic plate (15) is detachably installed on the trapezoidal bracket (14) by a number of screws.

3. The acid tank structure for a chain-type BSG removal machine according to claim 1, characterized in that, The flat acrylic plate (15) extends from the side away from the second acid tank (6) to the edge of the corresponding overflow tank. The side of the flat acrylic plate (15) close to the second acid tank (6) is completely separated from the edge of the second acid tank (6). The bottom of the overflow tank is provided with a conveying channel (16) connected to the corresponding tank body.

4. The acid tank structure for a chain-type BSG removal machine according to claim 1, characterized in that, The first water film area (3) and the second water film area (5) are provided with pure water nozzles. The pure water nozzles are used to spray pure water onto the surface of the silicon wafer body (1) to form a water film to protect the front of the silicon wafer body (1) and prevent it from being corroded by hydrofluoric acid solution.

5. The acid tank structure for a chain-type BSG removal machine according to claim 1, characterized in that, The drying tank (8) is equipped with a heating fan, which is used to generate hot air and dry the moisture on the surface of the silicon wafer body (1) after cleaning.

6. A method of using the acid tank structure for a chain-type BSG removal machine according to any one of claims 1-5, characterized in that, Specifically, the following steps are included: Step S1: The silicon wafer body (1) passes through the first water film area (3), the first acid tank (4), the second water film area (5), the second acid tank (6), the water tank (7) and the drying tank (8) in sequence along the forward direction to complete the BSG removal, cleaning and drying process; Step S2: During the transfer of the silicon wafer body (1), the water droplets generated by the rotation of the roller (2) located in the overflow area fall onto the flat acrylic plate (15) of the water guiding component. Through the inclined guiding effect of the flat acrylic plate (15), the water droplets on the surface of the silicon wafer body (1) are guided to the second water film area (5) or the inside of the water tank (7).

7. The method of using the acid tank structure for the chain-type BSG removal machine according to claim 6, characterized in that, Prior to step S1, a modification step for the overflow area is included, which specifically includes the following steps: Step 1: Customize several rectangular flat acrylic sheets (15) and several trapezoidal supports (14). Step 2: Empty all tanks and overflow tanks, and clean the inside of the tanks, the inside of the overflow tanks and the rollers (2) to ensure that there is no hydrofluoric acid solution residue in the tanks and overflow tanks. Step 3: Remove the roller (2) from the overflow area and place the roller (2) flat on one side according to the different positions of the overflow area to avoid deformation of the roller (2); Step 4: Wipe the inside of the overflow tank and use a welding torch to weld the trapezoidal bracket (14) into the corresponding overflow tank. The inclined side of the trapezoidal bracket (14) faces upward toward the side of the second acid tank (6). Step 5: Install the flat acrylic sheet (15) on the surface of the trapezoidal bracket (14) with several screws, so that one side of the flat acrylic sheet (15) is separated from the second acid tank (6) and the other side extends to the outside of the overflow tank. Step 6: Install the rollers (2) back in sequence according to the different positions of the overflow area; Step 7: Prepare hydrofluoric acid solution according to the ratio and resume production operation.

8. The method of using the acid tank structure for the chain-type BSG removal machine according to claim 7, characterized in that, The flat acrylic sheet (15) in step 1 has a thickness of 1cm, a length of 120cm, and a width of 20cm.

9. The method of using the acid tank structure for the chain-type BSG removal machine according to claim 6, characterized in that, The rollers (2) located at the top of the first acid tank (4) and the second acid tank (6) are both provided with threads, and the rollers (2) are immersed in hydrofluoric acid solution according to a preset ratio of 1 / 3 to 1 / 2.

10. The method of using the acid tank structure for the chain-type BSG removal machine according to claim 6, characterized in that, The concentration of hydrofluoric acid solution in the first acid tank (4) is higher than the concentration of hydrofluoric acid solution in the second acid tank (6).

Images