Cleaning line for slicing silicon wafers

Abstract

The utility model aims to provide the cleaning line for slicing the silicon wafer, which is simple in structure, energy-saving, environment-friendly and low in cost. According to the utility model, the cleaning part comprises the bubble water generator, the cleaning part comprises the plurality of cleaning tanks, and the silicon wafer slices are sequentially placed in the plurality of cleaning tanks to be cleaned; the plurality of cleaning tanks are sequentially a primary cleaning tank (1), an ultrasonic normal-temperature cleaning tank (2), a normal-temperature bubble water cleaning tank (3), a bubble water soaking cleaning tank (4), a first weak base water cleaning tank (5), a second weak base water cleaning tank (6) and a plurality of pure water rinsing cleaning tanks which are sequentially arranged; the bubble water generator inputs bubble water into the normal-temperature bubble water cleaning tank (3) and the bubble water soaking cleaning tank (4), and quantitative weak base water is added into the first weak base water cleaning tank (5) and the second weak base water cleaning tank (6). The utility model is applied to the field of cleaning equipment.

Description

Technical Field

[0001] The utility model relates to the field of cleaning equipment, in particular to a cleaning line for silicon wafer slicing. Background Art

[0002] At present, the surface atoms of silicon-based slices become dangling bonds due to the destruction of chemical bonds perpendicular to the slice direction, forming a free force field near the surface, which is very easy to adsorb various impurity surfaces, such as various organic matter, inorganic compounds, natural oxide layers, dust and other particles. In the past, various wet cleaning technologies were used for cleaning silicon-based slices. However, since the wet process uses a large amount of acidic and alkaline solutions and harmful chemicals, there are problems with the cost of acid and alkali consumables, wastewater treatment costs, and environmental supervision. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a cleaning line for silicon wafer slicing which is simple in structure, energy-saving, environmentally friendly and low-cost.

[0004] The technical solution adopted by the utility model is that the utility model includes a cleaning part, the cleaning part includes a bubble water generator, the cleaning part includes a plurality of cleaning tanks, silicon wafer slices are sequentially placed in the plurality of cleaning tanks for cleaning, the plurality of cleaning tanks are sequentially a preliminary cleaning tank, an ultrasonic room temperature cleaning tank, a room temperature bubble water cleaning tank, a bubble water immersion cleaning tank, a first weak alkaline water cleaning tank, a second weak alkaline water cleaning tank and a plurality of pure water rinsing cleaning tanks arranged in sequence, the bubble water generator inputs bubble water into the room temperature bubble water cleaning tank and the bubble water immersion cleaning tank respectively, and a quantitative amount of weak alkaline water is added to the first weak alkaline water cleaning tank and the second weak alkaline water cleaning tank.

[0005] The cleaning line also includes an ozone generator, which provides ozone gas to the bubble water generator.

[0006] The preliminary cleaning tank, the ultrasonic room temperature cleaning tank and the plurality of pure water rinsing cleaning tanks are filled with pure water, and an ultrasonic generator is arranged at the bottom of each cleaning tank.

[0007] Sodium hydroxide solution or potassium hydroxide solution is input into the first weak alkaline water cleaning tank and the second weak alkaline water cleaning tank.

[0008] The number of the pure water rinsing tanks is set to 2 to 4.

[0009] The cleaning line also includes a loading section arranged at the front end of the cleaning section and a drying unit arranged at the rear end of the cleaning section. The loading section transports the silicon wafer slices to the cleaning section. After the cleaning section completes cleaning of the silicon wafer slices, the silicon wafer slices are transported to the drying unit for drying and finally discharged.

[0010] The loading part includes a loading station and a slice inserting station, and the loading station and the slice inserting station transfer workpieces through a conveyor belt device. The slice inserting station is provided with a slice placing rack, and a plurality of slice fixing grooves are arranged at intervals on the slice placing rack. The slice placing rack is transported to the cleaning part for cleaning through a conveyor belt device.

[0011] The bubble water generator includes a shell, in which a liquid-gas mixing pump and at least one primary mixing tank channel are arranged, each of the primary mixing tank channels includes a primary pressure regulating valve and a primary mixing tank, the pressure in the primary mixing tank in each of the primary mixing tank channels is regulated by the primary pressure regulating valve in the channel, the input ends of all the primary mixing tank channels are connected to the output ends of the liquid-gas mixing pump, and a gas-liquid outlet assembly is arranged in the inner tank bottoms of the normal temperature bubble water cleaning tank and the bubble water immersion cleaning tank, the output end of each of the primary mixing tank channels is connected to the gas-liquid outlet assembly, and the gas-liquid outlet assembly injects bubble water into the normal temperature bubble water cleaning tank and the bubble water immersion cleaning tank, respectively.

[0012] The cleaning time of each silicon wafer slice in each cleaning tank is 80 to 120 seconds, the capacity of each cleaning tank is 150 to 300L, the liquid replacement time of the first weak alkaline water cleaning tank and the second weak alkaline water cleaning tank is 10 to 12 hours per time; the materials of the cleaning tank, the bubble water generator, and the pipes connecting the bubble water generator to the cleaning tanks are all 316 stainless steel, fluororesin material or fluorine-plated material; the diameter of the pipe connecting the bubble water generator to the cleaning tanks is φ15 to 30mm.

[0013] A closed cover is arranged above the cleaning part, and the closed cover covers the cleaning part in a relatively closed space. A waste gas treatment device is arranged above the space. The discharge port of the waste gas treatment device is connected to an exhaust device connected to the peripheral space. The exhaust device keeps the space in the closed cover in a negative pressure state. A number of ozone concentration monitors are also arranged in the space.

[0014] A closed outer enclosure box is arranged on the periphery of the ozone generator, and the closed outer enclosure box is connected to the relatively closed space covered by the closed cover in a normally closed manner, and an ozone concentration monitor is arranged in the closed outer enclosure box; when the ozone concentration monitor detects ozone leakage from the ozone generator, the connecting interface between the closed outer enclosure box and the relatively closed space is opened, and the gas in the relatively closed space is directly decomposed and discharged through the exhaust device.

[0015] The beneficial effects of the utility model are:

[0016] (1) In the utility model, a bubble water generator is used to generate bubble water, which is respectively introduced into the normal temperature bubble water cleaning tank and the bubble water immersion cleaning tank of the cleaning part. The cleaning part can be used as an independent module to transform the chemical reagent cleaning line in the prior art, and can be directly embedded or replaced; the cleaning part can also be used as an independent device; it has good applicability;

[0017] (2) Through the redox ability of the large amount of gas (ozone) in the bubble water, organic matter is removed from the surface of the product during cleaning. The generation of bubbles increases the solubility of ozone per unit volume, thus achieving industrially applicable cleaning applications.

[0018] (3) Each bubble in the bubble water has an electric charge on its surface. The surface charge of the bubble continues to concentrate as the bubble shrinks. When the bubble shrinks and bursts in the water, the pressure and electric potential stored in the bubble are released. The energy produces strong oxidative activity, and hydroxyl radicals (strong oxidants) are used to oxidize organic matter, inorganic matter, particulate matter, etc. on the surface of the product, thereby stripping and eliminating it.

[0019] (4) The specific surface area of ​​the bubbles themselves is large, which can increase the contact area between the bubbles and the cleaning product object and accelerate the cleaning speed;

[0020] (5) Some bubbles can produce Brownian motion in water, achieving rapid removal of particles on the product surface;

[0021] (6) Compared with the existing traditional technology, the cleaning line of the utility model maximizes the redox ability of ozone and utilizes the stripping ability of hydroxyl radicals to reduce the use of traditional chemical agents. Only a small amount of low-concentration weak alkaline water is added to the first weak alkaline water cleaning tank and the second weak alkaline water cleaning tank, or even no weak alkaline water is used, thus achieving green and environmentally friendly cleaning;

[0022] (7) Compared with the existing traditional technology, the utility model uses a small amount of or no chemical agents (low concentration), which reduces the secondary pollution or damage to the workpiece being cleaned, and also reduces the investment in chemical agents in the cleaning work, greatly reducing the cost. It also avoids the rework of damaged workpieces, shortens the process flow, and achieves the effect of reducing costs and increasing efficiency. According to experiments, compared with the existing technology, the utility model can reduce the investment in chemical cleaning agents by 80-90%;

[0023] (8) The utility model is simple to operate and easy to maintain, meeting the life requirements of standard equipment in the cleaning industry;

[0024] (9) In addition, the equipment of the utility model is easy to maintain and has low maintenance cost;

[0025] (10) The utility model operates under normal temperature conditions, avoiding the introduction of high temperature and improving the safety factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a simplified structural schematic diagram of the utility model from the first viewing angle;

[0027] Figure 2 It is a simplified structural schematic diagram of the utility model from a second viewing angle;

[0028] Figure 3 It is a simplified structural diagram of the cleaning unit from a top view angle;

[0029] Figure 4 is a simplified structural block diagram of the bubble water generator;

[0030] Figure 5 It is a simplified structural schematic diagram of the outlet portion of the gas-liquid outlet assembly. DETAILED DESCRIPTION

[0031] like Figures 1 to 5As shown, the utility model includes a cleaning part, the cleaning part includes a bubble water generator, the cleaning part includes a plurality of cleaning tanks, the silicon wafer slices are sequentially placed in the plurality of cleaning tanks for cleaning, the plurality of cleaning tanks are sequentially a preliminary cleaning tank 1, an ultrasonic normal temperature cleaning tank 2, a normal temperature bubble water cleaning tank 3, a bubble water immersion cleaning tank 4, a first weak alkaline water cleaning tank 5, a second weak alkaline water cleaning tank 6 and a plurality of pure water rinsing cleaning tanks arranged in sequence, the bubble water generator inputs bubble water into the normal temperature bubble water cleaning tank 3 and the bubble water immersion cleaning tank 4 respectively, and a quantitative weak alkaline water is added to the first weak alkaline water cleaning tank 5 and the second weak alkaline water cleaning tank 6. Here, only a small amount of weak alkaline water needs to be added to the cleaning tank, and the cleaning effect is better. In this embodiment, the transportation of silicon wafer slices between the cleaning tanks is realized by a mobile manipulator 19 arranged above the cleaning part. When the cleaning tank located in the previous one completes the work, the mobile manipulator 19 moves the material basket containing the silicon wafer slice materials to the cleaning tank located in the next one for cleaning. Each material basket can load 4 slice racks (the slice rack is a purchased part, its main function is to hold silicon wafer slices and ensure that there is a gap between the slices, and no two slices are overlapped), so as to ensure its cleaning efficiency.

[0032] The cleaning line also includes an ozone generator 11, which provides ozone gas for the bubble water generator. A closed cover 37 is provided above the cleaning part, and the closed cover 37 covers the cleaning part in a relatively closed space. An exhaust gas treatment device (to achieve ozone decomposition) is provided above the space. The exhaust port of the exhaust gas treatment device is connected to an exhaust device 38 (exhaust fan or exhaust blower) connected to the peripheral space. The exhaust device keeps the space in the closed cover 37 in a negative pressure state. Several ozone concentration monitors are also provided in the space. The ozone generator 11 is provided with a sealed outer enclosure box on its periphery, and the sealed outer enclosure box is connected to the relatively closed space covered by the sealed cover 37 in a normally closed manner, and an ozone concentration monitor is provided in the sealed outer enclosure box; when the ozone concentration monitor detects ozone leakage from the ozone generator, the connecting interface between the sealed outer enclosure box and the relatively closed space is opened, and the gas in the relatively closed space is directly decomposed and discharged through the exhaust device.

[0033] Each cleaning tank works independently. In this embodiment, a water collecting tank 26 is also connected to the rear ends of the normal temperature bubble water cleaning tank 3 and the bubble water soaking cleaning tank 4. The water collecting tank 26 collects waste water overflowing from the cleaning tank. The water collecting tank 26 is provided with a circulation pipe 27 connected to the liquid input end of the liquid-gas mixing pump 13. The circulation pipe 27 is provided with a filter device 28. In this embodiment, the filter device 28 uses a filter screen, and the screen is selected from a filter screen of 80 to 120 mesh.

[0034] The preliminary cleaning tank 1, the ultrasonic normal temperature cleaning tank 2 and the plurality of pure water rinsing cleaning tanks are filled with pure water, and an ultrasonic generator 25 is provided at the bottom of each cleaning tank. The ultrasonic generator is provided at the inner bottom of the cleaning tank, and the number of ultrasonic generators in each cleaning tank is not less than 2. In this embodiment, two ultrasonic generators 25 are provided at the bottom of each cleaning tank.

[0035] Sodium hydroxide solution or potassium hydroxide solution is input into the first weak alkaline water cleaning tank 5 and the second weak alkaline water cleaning tank 6. In the present embodiment, the concentration of the sodium hydroxide solution or the potassium hydroxide solution is 1-5%. The number of the pure water rinsing cleaning tanks is set to 2-4. In the present embodiment, the number of the pure water rinsing cleaning tanks is set to 4, which are the first pure water rinsing cleaning tank 7, the second pure water rinsing cleaning tank 8, the third pure water rinsing cleaning tank 9 and the fourth pure water rinsing cleaning tank 10 connected in sequence. Here, according to demand, the first weak alkaline water cleaning tank 5 and the second weak alkaline water cleaning tank 6 can also be replaced with a pure water ultrasonic cleaning tank, and the product surface is cleaned by a combination of pure water and ultrasonic waves.

[0036] The cleaning line also includes a loading section arranged at the front end of the cleaning section and a drying unit arranged at the rear end of the cleaning section. The loading section transports the silicon wafer slices to the cleaning section. After the cleaning section completes cleaning of the silicon wafer slices, the silicon wafer slices are transported to the drying unit for drying and finally discharged.

[0037] The loading part includes a loading station and a slice inserting station, and the loading station and the slice inserting station transfer workpieces through a conveyor belt device. The slice inserting station is provided with a slice placing rack, and a plurality of slice fixing grooves are arranged at intervals on the slice placing rack. The slice placing rack is transported to the cleaning part for cleaning through a conveyor belt device.

[0038] The bubble water generator includes a shell, in which a liquid-gas mixing pump 13 and at least one primary mixing tank channel are arranged, each of the primary mixing tank channels includes a primary pressure regulating valve 14 and a primary mixing tank 15, the pressure in the primary mixing tank 15 in each of the primary mixing tank channels is regulated by the primary pressure regulating valve 14 in the channel, the input ends of all the primary mixing tank channels are connected to the output ends of the liquid-gas mixing pump 13, a gas-liquid outlet assembly 16 is arranged in the inner tank bottom of the normal temperature bubble water cleaning tank 3 and the bubble water soaking cleaning tank 4, the output end of each of the primary mixing tank channels is connected to the gas-liquid outlet assembly 16, and the gas-liquid outlet assembly 16 injects bubble water into the normal temperature bubble water cleaning tank 3 and the bubble water soaking cleaning tank 4 respectively. In this embodiment, the number of the primary mixing tank channels is set to 6.

[0039] like Figure 5 As shown, the outlet of the gas-liquid outlet assembly 16 adopts a nozzle structure capable of generating microbubbles, which includes a hollow and cylindrical shell 29, an input tube cavity 30 coaxially arranged with the shell 29 and tightly fitted at the end, the outer diameter of the input tube cavity 30 extending into the shell 29 is smaller than the inner diameter of the hollow part of the shell 29, the inside of the input tube cavity is hollow, and a first through hole 31 connecting the inside and outside of the input tube cavity 30 is arranged on the side wall of one end placed in the shell 29, and a first pressure release chamber 35 is formed in the input tube cavity 30 and in the area close to the first through hole 31. A plurality of second through holes 32 connecting the inside and outside of the shell 29 are arranged on the wall surface of the shell 29, and a second pressure release chamber 36 is formed in the shell 29 and in the area close to the second through holes 32. Four layers of porous plates 33 are arranged in the input tube cavity 30, and each layer of porous plates 33 is separated by a partition plate 34. The apertures of the four porous plates 33 are arranged in the order from the inlet of the input tube cavity 30 to the inside of the input tube cavity 30, and the apertures of the small holes on each porous plate are set to φ0.8mm, φ1.2mm, φ1.5mm, and φ1.2mm in sequence. The outer diameters of the porous plates and the partition plates are smaller than the inner diameter of the input tube cavity 30. In the superposition of the partition plates and the porous plates, there are gaps between the plates. Bubble water is input from the inlet of the input tube cavity 18, and after passing through the partition plates and the porous plates, the bubble water is divided by the porous plates; enters the first pressure release chamber 35, and then passes through the first through hole 31 to enter the second pressure release chamber 35. In the process of entering the second pressure release chamber from the first through hole, the bubble water is divided again to produce more bubble water; finally, the bubble water is scattered from the second through hole of the second pressure release chamber and enters the cleaning tank for cleaning.

[0040] The front end of the liquid-gas mixing pump 13 is provided with a pure liquid output tank 20 and a gas storage tank 21. The pure liquid output tank 20 controls the flow rate through a control valve 22 and is connected to the liquid input port of the liquid-gas mixing pump 13 to provide pure water for the liquid-gas mixing pump 13. The gas storage tank 21 is connected to the gas input port of the liquid-gas mixing pump 13 through a gas flow valve 23 and a gas switch 24 to provide gas for the liquid-gas mixing pump 13. In this embodiment, the pure liquid is pure water, and the injected gas is ozone.

[0041] The cleaning time of each silicon wafer in each cleaning tank is 80 to 120 seconds, and the capacity of each cleaning tank is 150 to 300L. The liquid replacement time of the first weak alkaline water cleaning tank 5 and the second weak alkaline water cleaning tank 6 is 10 to 12 hours per time (the specific time depends on the cleaning effect), which can ensure the cleaning effect. If it exceeds 12 hours, the cleaning effect will be reduced; the cleaning tank, the bubble water generator, and the pipe connecting the bubble water generator to the cleaning tank are all made of 316 stainless steel, fluororesin or fluorine-plated material; the diameter of the pipe connecting the bubble water generator to the cleaning tank is φ15 to 30mm.

[0042] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cleaning line for silicon wafer slicing, comprising a cleaning section, characterized in that: The cleaning section comprises a bubble water generator, and the cleaning section comprises a plurality of cleaning tanks. The silicon wafer slices are sequentially placed in the plurality of cleaning tanks for cleaning. The plurality of cleaning tanks are sequentially a preliminary cleaning tank (1), an ultrasonic room temperature cleaning tank (2), a room temperature bubble water cleaning tank (3), a bubble water immersion cleaning tank (4), a first weak alkaline water cleaning tank (5), a second weak alkaline water cleaning tank (6), and a plurality of pure water rinsing cleaning tanks arranged in sequence. The bubble water generator inputs bubble water into the room temperature bubble water cleaning tank (3) and the bubble water immersion cleaning tank (4), respectively, and a certain amount of weak alkaline water is added into the first weak alkaline water cleaning tank (5) and the second weak alkaline water cleaning tank (6).

2. A cleaning line for silicon wafer slicing according to claim 1, characterized in that: The cleaning line further comprises an ozone generator (11), wherein the ozone generator (11) provides ozone gas for the bubble water generator.

3. A cleaning line for silicon wafer slicing according to claim 1, characterized in that: The preliminary cleaning tank (1), the ultrasonic room temperature cleaning tank (2) and the plurality of pure water rinsing cleaning tanks are all filled with pure water, and an ultrasonic generator (25) is provided at the bottom of each cleaning tank.

4. A cleaning line for silicon wafer slicing according to claim 1, characterized in that: Sodium hydroxide solution or potassium hydroxide solution is input into the first weak alkaline water cleaning tank (5) and the second weak alkaline water cleaning tank (6).

5. The cleaning line for silicon wafer slicing according to claim 1, characterized in that: The number of the pure water rinsing tanks is set to 2 to 4.

6. A cleaning line for silicon wafer slicing according to claim 1, characterized in that: The cleaning line also includes a loading section arranged at the front end of the cleaning section and a drying unit arranged at the rear end of the cleaning section. The loading section transports the silicon wafer slices to the cleaning section. After the cleaning section completes cleaning of the silicon wafer slices, the silicon wafer slices are transported to the drying unit for drying and finally discharged.

7. A cleaning line for silicon wafer slicing according to claim 6, characterized in that: The loading part includes a loading station and a slice inserting station, and the loading station and the slice inserting station transfer workpieces through a conveyor belt device. The slice inserting station is provided with a slice placing rack, and a plurality of slice fixing grooves are arranged at intervals on the slice placing rack. The slice placing rack is transported to the cleaning part for cleaning through a conveyor belt device.

8. A cleaning line for silicon wafer slicing according to claim 7, characterized in that: The bubble water generator comprises a shell, in which a liquid-gas mixing pump (13) and at least one primary mixing tank channel are arranged, each of the primary mixing tank channels comprises a primary pressure regulating valve (14) and a primary mixing tank (15), the pressure in the primary mixing tank (15) in each of the primary mixing tank channels is regulated by the primary pressure regulating valve (14) in the channel, the input ends of all the primary mixing tank channels are connected to the output ends of the liquid-gas mixing pump (13), a gas-liquid outlet assembly (16) is arranged in the inner tank bottoms of the normal temperature bubble water cleaning tank (3) and the bubble water soaking cleaning tank (4), the output end of each of the primary mixing tank channels is connected to the gas-liquid outlet assembly (16), and the gas-liquid outlet assembly (16) injects bubble water into the normal temperature bubble water cleaning tank (3) and the bubble water soaking cleaning tank (4), respectively.

9. A cleaning line for silicon wafer slicing according to claim 1, characterized in that: The cleaning time of each silicon wafer slice in each cleaning tank is 80 to 120 seconds, the capacity of each cleaning tank is 150 to 300 L, and the liquid replacement time of the first weak alkaline water cleaning tank (5) and the second weak alkaline water cleaning tank (6) is 10 to 12 hours per time; the materials of the cleaning tank, the bubble water generator, and the pipes connecting the bubble water generator to the cleaning tanks are all 316 stainless steel, fluororesin material or fluorine-plated material; the diameter of the pipe connecting the bubble water generator to the cleaning tanks is φ15 to 30 mm.

10. A cleaning line for silicon wafer slicing according to claim 2, characterized in that: A closed cover (37) is arranged above the cleaning section, and the closed cover (37) covers the cleaning section in a relatively closed space. An exhaust gas treatment device is arranged above the space, and the exhaust port of the exhaust gas treatment device is connected to an exhaust device connected to the peripheral space. The exhaust device keeps the space in the closed cover (37) in a negative pressure state. A plurality of ozone concentration monitors are also arranged in the space.

11. A cleaning line for silicon wafer slicing according to claim 10, characterized in that: The ozone generator (11) is provided with a sealed outer enclosure on its periphery, the sealed outer enclosure being connected to a relatively sealed space covered by the sealed cover (37) in a normally closed manner, and an ozone concentration monitor is provided in the sealed outer enclosure; when the ozone concentration monitor detects ozone leakage from the ozone generator, the connection interface between the sealed outer enclosure and the relatively sealed space is opened, and the gas in the relatively sealed space is directly decomposed and discharged through the exhaust device.

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