Silicon wafer polishing solution recovery buffer device

Abstract

The invention discloses a silicon wafer polishing solution recovery buffer device which is provided with a box body, a guide plate, a spoiler and a filter screen, and the box body is provided with a liquid inlet pipeline connector and a liquid outlet pipeline connector; a fragment collecting tank communicated with the box body is arranged below the box body close to the liquid inlet pipeline interface, and the fragment collecting tank is provided with a liquid discharge pipeline interface; a guide plate and more than two groups of spoilers are sequentially arranged in the box body along the direction from the liquid inlet pipeline interface to the liquid outlet pipeline interface; the guide plate is arranged between two opposite side walls of the box body, and a gap is formed between the guide plate and the bottom of the box body; each group of spoilers comprises two spoilers which are parallel to each other and a filter screen which is arranged between the two spoilers; every two adjacent groups of spoilers are arranged in a staggered mode, and the inner wall of the box body, the spoilers and the filter screen form a snake-shaped channel for the polishing solution to flow through. The problems of process abnormality, downtime and the like caused by the fact that silicon wafer disintegrating slag enters a polishing solution recovery system due to fragments in the polishing process can be effectively avoided.

Description

Technical Field

[0001] The present invention relates to a buffer device for recycling silicon wafer polishing liquid, belonging to the technical field of silicon wafer production and processing. Background Art

[0002] During the processing of silicon wafers in the polishing process, due to reasons such as the polishing cloth or polishing pad approaching the end of its service life, changes in polishing process parameters, and quality problems of the silicon wafers themselves, fragmentation may occur. Especially during the polishing process on the machine, if the fragments are not detected in time, the fragments will be ground into fine slag in a short time, and these fragments and fine slag will enter the polishing liquid recycling system through the polishing liquid recycling pipeline. According to the actual processing situation at the production site, even if a filter screen has been added to the polishing liquid recycling system, there will still be fine slag entering the polishing liquid recycling system. If these fine slag are not cleaned up, it will cause processing abnormalities such as scratches and fragmentation of the silicon wafers, resulting in process abnormalities, forced shutdown of the equipment, and directly affecting the production and processing progress. Summary of the Invention

[0003] The purpose of the present invention is to provide a buffer device for recycling silicon wafer polishing liquid, which can effectively avoid problems such as process abnormalities and shutdown caused by silicon wafer fragments entering the polishing liquid recycling system during the polishing process.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions: A buffer device for recycling silicon wafer polishing liquid, the device includes a box body, a flow guide plate, a flow blocking plate, and a filter screen. Among them, The box body is provided with an inlet pipeline interface and an outlet pipeline interface; a debris collection tank communicated with the box body is provided below the box body near the inlet pipeline interface, and the debris collection tank is provided with a drain pipeline interface; Inside the box body, a flow guide plate and two or more groups of flow blocking plates are arranged in sequence from the inlet pipeline interface to the outlet pipeline interface; the flow guide plate is installed between the opposite side walls of the box body, and a gap is formed between the flow guide plate and the bottom of the box body; Each group of flow blocking plates includes two parallel flow blocking plates and a filter screen arranged between the two flow blocking plates; adjacent groups of flow blocking plates are arranged in a staggered manner, and a serpentine channel for the polishing liquid to flow through is formed by the inner wall of the box body, the flow blocking plates, and the filter screen.

[0005] Further, the filter screen is pre-installed in a filter screen fixture to form a filter screen assembly, and the filter screen assembly is vertically inserted into the filter screen assembly installation slots of the two flow blocking plates.

[0006] Further, the filter screen assembly is assembled by two filter screen fixtures and a filter screen sandwiched between the two filter screen fixtures through countersunk head bolts.

[0007] Further, the inlet pipeline interface and the outlet pipeline interface are arranged at the upper ends of the opposite side walls of the box body, and the drain pipeline interface is arranged at the bottom of the debris collection tank.

[0008] Further, the flow guide plate is composed of a straight plate part and an inclined plate part. The inclined plate part is connected to the lower end of the straight plate part, and the gap between the flow guide plate and the bottom of the box body forms a polishing liquid flow guide port.

[0009] Further, there are two sets of baffle plates.

[0010] Further, the box body is of a cuboid structure, and the inlet pipeline interface and the outlet pipeline interface are arranged at the upper ends of the opposite short side walls of the box body.

[0011] Further, a box cover is arranged on the top of the box body, and four support legs are arranged at the bottom.

[0012] Further, two grab ears are arranged above the box cover, and two clamping blocks for clamping with the box body are arranged below.

[0013] Further, the box body, the box cover and the filter screen fixture are made of clean PVC material, and the filter screen is made of nylon material.

[0014] The advantages of the present invention are as follows: The silicon wafer polishing liquid recovery buffer device of the present invention has the characteristics of simple structure, convenient installation and use. When the machine has debris, it can play a role in timely filtering the debris and slag, and can effectively avoid problems such as process anomalies and machine downtime caused by the debris of the silicon wafer entering the polishing liquid recovery system during the polishing process of the silicon wafer, improve the processing efficiency during debris occurrence, reduce the frequency of process anomalies, and thus improve the processing productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the silicon wafer polishing liquid recovery buffer device of the present invention.

[0016] Figure 2 It is a top view of the silicon wafer polishing liquid recovery buffer device of the present invention without the box cover installed.

[0017] Figure 3 is Figure 1 a cross-sectional view along the up and down direction.

[0018] Figure 4 It is a schematic diagram of the structure of the filter screen assembly of the silicon wafer polishing liquid recovery buffer device of the present invention.

[0019] Figure 5 It is a schematic diagram of the structure of the box cover of the silicon wafer polishing liquid recovery buffer device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this does not mean any limitation to the protection scope of the present invention.

[0021] As Figures 1 to 3 shown, the polishing liquid recovery buffer device proposed by the present invention includes a box body 1, a box body cover 2, a filter screen fixture 31, a filter screen fixture 32, and a filter screen 4; the overall contour of the box body 1 is in a cuboid structure, and the box body cover 2 is arranged on the top of the box body 1 to ensure the cleanliness of the polishing liquid; four support legs are provided at the bottom of the box body 1, namely two long support legs 11 and two short support legs 12.

[0022] The box body 1 is provided with a liquid inlet pipeline interface 13, a liquid outlet pipeline interface 14, and a liquid discharge pipeline interface 15. Inside the box body 1, there are a debris collection groove 16, a diversion plate 17, a flow blocking plate 18, and a filter screen assembly installation card slot 19. Among them, the liquid inlet pipeline interface 13 and the liquid outlet pipeline interface 14 are arranged at the upper ends of the mutually opposite short side walls of the box body. The debris collection groove 16 is located below the box body near the liquid inlet pipeline interface and is communicated with the box body; the liquid discharge pipeline interface 15 is arranged at the bottom of the debris collection groove 16. Inside the box body, looking from the direction of the liquid inlet pipeline interface 13 towards the liquid outlet pipeline interface 14, the debris collection groove 16, the diversion plate 17, and two or more groups of flow blocking plates 18 are arranged in sequence. The diversion plate 17 is installed between the two opposite long side walls, and a gap is formed between the diversion plate 17 and the bottom of the box body as a polishing liquid diversion port. Each group of flow blocking plates 18 includes two spaced and parallel flow blocking plates and a filter screen assembly 5 arranged between the two flow blocking plates. Adjacent groups of flow blocking plates are arranged in a staggered manner, that is, one group of flow blocking plates is connected to one side wall of the box body and extends towards the opposite side wall, and the other group of flow blocking plates is connected to the other side wall of the box body and extends towards the opposite side wall. The space positions of adjacent groups of flow blocking plates partially overlap in the polishing liquid flow direction, and the flow blocking plates in the overlapping part are in contact with the filter screen of the adjacent group, so that a serpentine channel for the polishing liquid to flow is formed by the inner wall of the box body, the flow blocking plates, and the filter screen.

[0023] As Figure 4 shown, the filter screen assembly 5 can be assembled by 2 filter screen fixtures 31, a filter 32, and 1 filter screen 4. The filter screen fixtures 31 and 32 are respectively in a frame shape. The filter screen fixture 31 is provided with bolt holes, and the filter screen fixture 32 is provided with countersunk head bolt holes. The filter screen 4 is clamped between the two filter screen fixtures 31 and 32 and fixed by countersunk head bolts, which is convenient for disassembly and replacement. The filter screen assembly 5 is vertically inserted into the installation card slot 19 on the flow blocking plate 18.

[0024] As Figure 5 shown, 2 handle ears 21 are provided above the box body cover 2, and 2 clamping blocks 22 for engaging with the box body are provided below, which can conveniently cover the box body 1.

[0025] In the present invention, the box body 1, the box cover 2, the filter screen clamps 31 and 32 are made of clean PVC material, the filter screen 4 is made of nylon material, and the countersunk head bolts can be countersunk head bolts made of non-metallic materials such as PEEK.

[0026] During actual application, the operation process of the polishing liquid recovery buffer device of the present invention is as follows: The polishing liquid recovery buffer device is arranged at the polishing liquid return liquid switching device on the polishing table of the machine tool. The liquid inlet pipeline interface 13 of the box body 1 is connected to the outlet of the table polishing liquid return liquid switching device. The filter screen assembly 5 is arranged at the filter screen assembly installation slot 19 of the box body 1. The polishing liquid enters the box body 1 through the liquid inlet pipeline interface 13. First, it flows into the debris collection tank 16 under the guiding action of the guiding plate 17. After the polishing liquid fills the debris collection tank 16, it flows through the reserved gap between the lower part of the guiding plate 17 and the bottom of the box body 1 to the first baffle plate 18, and then successively passes through the first half and the second half of the first filter screen assembly 5, flows to the second baffle plate 18, then passes through the first half and the second half of the second filter screen assembly 5, flows out of the second baffle plate 18, and finally flows to the liquid outlet pipeline interface 14. The outlet pipeline 14 is connected to the pipeline of the machine tool polishing liquid recovery station. The liquid discharge pipeline interface 15 at the debris collection tank 16 is connected to the factory service liquid discharge pipeline.

[0027] During actual application, when debris is generated during the polishing process, the debris and slag will first enter the polishing liquid recovery buffer device of the present invention along with the polishing liquid and will not directly enter the polishing liquid recovery circulation system. Larger debris and slag will precipitate in the debris collection tank 16 of the box body 1. The flow rate of the polishing liquid with fine slag will be reduced by the baffle plate 18, and at the same time, through the filtering action of the filter screen multiple times, the fine slag can be effectively filtered to ensure that the outflowing polishing liquid does not contain fine slag, and only the polishing liquid recovery buffer device needs to be cleaned. When cleaning the polishing liquid recovery buffer device, after removing the box cover 2, the filter screen assembly 5 can be removed, and the filter screen can be cleaned or replaced according to the usage condition of the filter screen 4. The debris and slag in the debris collection tank 16 can be cleaned by a vacuum cleaner, and finally, the inside of the entire box body 1 is rinsed with water, and the rinsing water is discharged through the liquid discharge pipeline interface 15.

[0028] The present invention can achieve the rapid treatment of debris and slag during the processing of the silicon wafer polishing machine, effectively filter the debris and slag in the polishing liquid, solve the problem that debris and slag are likely to enter the polishing liquid recovery system during the fragmentation of the polishing machine, improve the cleanliness of the polishing liquid, reduce the frequency of process anomalies, and thus improve the processing productivity.

Claims

1. A silicon wafer polishing liquid recovery buffer device, characterized in that: The device comprises a box, a guide plate, a baffle, and a filter, wherein: The box body is provided with a liquid inlet pipeline interface and a liquid outlet pipeline interface; a debris collection tank connected to the box body is provided below the box body near the liquid inlet pipeline interface, and the debris collection tank is provided with a liquid discharge pipeline interface; Inside the box, a guide plate and two or more groups of baffles are arranged in sequence along the direction from the inlet pipe interface to the outlet pipe interface; the guide plate is installed between the two opposite side walls of the box, and a gap is formed between the guide plate and the bottom of the box; Each set of baffles includes two parallel baffles and a filter screen arranged between the two baffles; two adjacent sets of baffles are arranged in a staggered manner, and the inner wall of the box, the baffles and the filter screen form a serpentine channel for the polishing liquid to flow.

2. The silicon wafer polishing liquid recovery buffer device according to claim 1, characterized in that: The filter screen is pre-installed on a filter screen fixture to form a filter screen assembly, and the filter screen assembly is vertically inserted into the filter screen assembly installation slots of the two spoilers.

3. The silicon wafer polishing liquid recovery buffer device according to claim 2, characterized in that: The filter assembly is assembled by two filter clamps and a filter clamped between the two filter clamps through countersunk bolts.

4. The silicon wafer polishing liquid recovery buffer device according to claim 1, characterized in that: The liquid inlet pipeline interface and the liquid outlet pipeline interface are arranged at the upper ends of the two side walls of the box body facing each other, and the liquid discharge pipeline interface is arranged at the bottom of the debris collection tank.

5. The silicon wafer polishing liquid recovery buffer device according to claim 1, characterized in that: The guide plate is composed of a straight plate part and an inclined plate part, the inclined plate part is connected to the lower end of the straight plate part, and the gap between the guide plate and the bottom of the box body constitutes a polishing liquid guide port.

6. The silicon wafer polishing liquid recovery buffer device according to claim 1, characterized in that: The spoiler is provided with two groups.

7. The silicon wafer polishing liquid recovery buffer device according to claim 1 or 4, characterized in that: The box body is in a rectangular parallelepiped structure, and the liquid inlet pipeline interface and the liquid outlet pipeline interface are arranged at the upper ends of the short side walls of the box body that are opposite to each other.

8. The silicon wafer polishing liquid recovery buffer device according to claim 1, characterized in that: The top of the box is provided with a box cover, and the bottom is provided with four supporting legs.

9. The silicon wafer polishing liquid recovery buffer device according to claim 8, characterized in that: The box cover is provided with two grab ears on the top and two clamping blocks for clamping with the box on the bottom.

10. The silicon wafer polishing liquid recovery buffer device according to claim 8, characterized in that: The box body, box cover and filter screen fixture are made of clean PVC material, and the filter screen is made of nylon material.

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