Solid-liquid separation apparatus and solid-liquid separation method using the same

Abstract

To provide a solid-liquid separation apparatus capable of easily and fully automatically separating and recovering solids contained in a liquid such as semiconductor wafer scraps.SOLUTION: A solid-liquid separation apparatus 100 according to the present invention comprises: a liquid-permeable conveyor belt 10; a solid-liquid supply section 20 that supplies a liquid containing solids onto the conveyor belt 10; a roller 30 located downstream of the solid-liquid supply section 20 in the conveying direction of the conveyor belt 10 and supporting the conveyor belt 10 from below; a pressurized gas supply section 40 that supplies pressurized gas to a portion of the conveyor belt 10 supported by the roller 30; and a solid recovery section 50 located downstream of the roller 30 in the conveying direction of the conveyor belt 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a solid-liquid separation device and a solid-liquid separation method using the same. [Background technology]

[0002] In the semiconductor manufacturing process, a semiconductor wafer is processed to a predetermined thickness by grinding the back surface thereof with a grinding device, and then the wafer is divided into individual devices with a dicing device (cutting device).

[0003] Semiconductor wafers are usually circular, and the peripheral portion of the wafer is discarded as scrap after devices are diced. A large amount of water is used in the dicing process, and the scrap semiconductor wafer is discarded together with the waste liquid.

[0004] Patent Document 1 discloses a method for recovering scraps of semiconductor wafers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-93004 Summary of the Invention [Problem to be solved by the invention]

[0006] The scraps of semiconductor wafers collected together with the wastewater are difficult to handle because they are sharp and can damage resin pipes and filters. Furthermore, scraps are not always generated in the semiconductor manufacturing process, but are only generated during the dicing process.

[0007] Therefore, when separating and recovering scraps from waste liquid, humans manually recover the scraps as they accumulate, but it can sometimes be difficult to determine when to recover the scraps.

[0008] Therefore, an object of the present invention is to provide a solid-liquid separation device that can easily separate and recover solids contained in liquids such as semiconductor wafer scraps in a fully automatic manner, and a solid-liquid separation method using the same. [Means for solving the problem]

[0009] The present inventors have found that the above problems can be solved by the present invention, which includes the following embodiments.

[0010] In one embodiment, the solid-liquid separation apparatus of the present invention is Liquid-permeable conveyor belt, a solid-liquid supplying section that supplies a liquid containing a solid onto the conveyor belt; a roller positioned downstream of the solid-liquid supply unit in the conveying direction of the conveyor belt and supporting the conveyor belt from below; a pressurized gas supply unit that supplies pressurized gas to the portion of the conveyor belt supported by the roller; and a recovery section for the solid material, the recovery section being located downstream of the roller in the conveying direction of the conveyor belt; It is equipped with:

[0011] In one embodiment, in the solid-liquid separation device of the present invention, the conveyor belt is made of a metal mesh.

[0012] In one embodiment, in the solid-liquid separation device of the present invention, the pressurized gas supply unit is located at a distance of 10 cm or less from the conveyor belt.

[0013] In one embodiment, in the solid-liquid separation device of the present invention, the pressurized gas supply unit supplies the pressurized gas to substantially the entire width of the conveyor belt.

[0014] In one embodiment, the solid-liquid separation device of the present invention includes two or more combinations of the pressurized gas supply unit and the roller.

[0015] In one embodiment, in the solid-liquid separation device of the present invention, the conveyor belt is folded back at an acute angle at an end portion thereof, and the recovery section is located below the end portion of the conveyor belt.

[0016] In one embodiment, the solid-liquid separator of the present invention has a pressurized gas supply unit for solid separation on the back side of the conveyor belt folded back at an acute angle.

[0017] In one embodiment, the solid-liquid separator of the present invention has a pressurized gas supply unit for solid separation on the back side of the conveyor belt folded back at an acute angle.

[0018] In one embodiment, the solid-liquid separation device of the present invention includes a solid recovery baffle plate downstream of the solid peeling pressurized gas supply unit in the conveying direction of the conveyor belt.

[0019] In one embodiment, the solid-liquid separation device of the present invention is a device for separating semiconductor wafer scraps from water.

[0020] In one embodiment, the solid-liquid separation method of the present invention is a method for separating semiconductor wafer scraps from water using the solid-liquid separation device. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a solid-liquid separation device that can easily separate and recover solids contained in liquid, such as semiconductor wafer scraps, in a fully automatic manner, and a solid-liquid separation method using the same. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 shows a schematic diagram of the device of the present invention. [Figure 2] FIG. 2 is a photograph of the pressurized gas supply of one embodiment of the device of the present invention. [Figure 3] FIG. 3 is a photograph of rollers that support the conveyor belt from below in one embodiment of the device of the present invention. [Figure 4] FIG. 4 is a photograph of the end of the conveyor belt of one embodiment of the apparatus of the present invention. [Figure 5] FIG. 5 is a photograph of a pressurized gas supply unit for solid peeling located on the back side of the conveyor belt of one embodiment of the apparatus of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be specifically described using the following embodiments as examples, but the present invention is not limited thereto. Unless a specific description is given of each device, mechanism, means, etc. in this specification, those skilled in the art can use mechanical devices, mechanisms, means, etc. that are well known to those skilled in the art. Each embodiment can be combined based on the ordinary knowledge of those skilled in the art, and configurations not specifically described in each embodiment can have the same configuration as other embodiments or a configuration appropriate for that embodiment.

[0024] FIG. 1 shows a schematic diagram of one embodiment of the apparatus of the present invention.

[0025] The solid-liquid separation apparatus 100 of the present invention comprises a liquid-permeable conveyor belt 10; a solid-liquid supply section 20 that supplies a liquid containing solids onto the conveyor belt 10; rollers 30 that are located downstream of the solid-liquid supply section 20 in the conveying direction of the conveyor belt 10 and support the conveyor belt 10 from below; a pressurized gas supply section 40 that supplies pressurized gas to the portion of the conveyor belt 10 supported by the rollers 30; and a solid recovery section 50 that is located downstream of the rollers 30 in the conveying direction of the conveyor belt 10.

[0026] When attempting to recover solids by supplying a liquid containing solids onto the conveyor belt 10 of the solid-liquid separator 100, the presence of liquid at the interface between the solids and the conveyor belt 10 can make it difficult to separate the solids from the conveyor belt 10, making recovery of the solids difficult. In particular, semiconductor wafer scraps are extremely flat because they have undergone a CMP process, and can adhere strongly to the conveyor belt 10, making separation extremely difficult.

[0027] In response to this problem, the present inventors attempted to dry the liquid by blowing high-temperature hot air onto the conveyor belt 10 of the solid-liquid separator 100, or to remove the liquid by blowing high-pressure air onto the conveyor belt 10. However, the liquid penetrated the liquid-permeable interior of the conveyor belt 10, making it extremely difficult to remove the liquid from the conveyor belt 10. However, after further intensive research, the present inventors discovered that if the conveyor belt 10 is supported from below by rollers 30 and pressurized gas is supplied from above to the area supported by the rollers 30, the liquid present on the conveyor belt 10 moves toward the rollers 30, and a large amount of liquid is removed from the conveyor belt 10. Furthermore, with this solid-liquid separator 100, substantially only solids remain on the conveyor belt 10, making it easy to recover solids that are difficult to recover, such as semiconductor wafer scraps.

[0028] In this specification, "upper" and "lower" may be interpreted in a general sense, with the direction of gravity being "down." For example, "upper side" and "front side" refer to the surface of the conveyor belt 10 to which the solid-containing liquid is supplied from the solid-liquid supply unit 20. Furthermore, "lower side" and "rear side" refer to the surface of the conveyor belt 10 opposite to the upper side and front side.

[0029] The conveyor belt 10 is not particularly limited as long as it is liquid-permeable, and can be, for example, a porous belt, particularly a mesh belt. The material of the conveyor belt 10 is also not particularly limited as long as it is a material for a normal conveyor belt used in a belt conveyor, and can be, for example, metal, particularly stainless steel. As shown in FIG. 2, the conveyor belt 10 can be made of a metal mesh. The conveyor belt 10 can be operated continuously, rotating like a belt conveyor, to enable continuous conveyance.

[0030] The solid-liquid supply unit 20 is not particularly limited as long as it can supply a liquid containing a solid. The solid may be a plate-like body that easily sticks to the conveyor belt 10, such as scraps of semiconductor wafers. The liquid is not particularly limited and may be water.

[0031] 1 and 2, the solid-liquid supply unit 20 may further have a cover 21 for preventing the solid and liquid supplied from the solid-liquid supply unit 20 from scattering from the conveyor belt 10. In addition, by using the cover 21 to limit the position of the solid falling onto the conveyor belt 10 to a portion of the width of the conveyor belt 10, the pressurized gas can be supplied from the pressurized gas supply unit only to that width.

[0032] The rollers 30 support the conveyor belt 10 from below, thereby allowing water to move toward the rollers 30 when pressurized gas is supplied. The solid-liquid separator 100 can be equipped with a plurality of sets of rollers 30 and pressurized gas supply units 40, thereby ensuring that the liquid on the conveyor belt 10 is discharged toward the rollers 30.

[0033] The liquid discharged toward the roller 30 can be collected by a waste liquid collection unit 80 located at the bottom of the device 100. The waste liquid collection unit 80 is located below the solid-liquid supply unit 20, so that the discharged liquid can be widely collected.

[0034] 3 is a photograph of the roller 30 during actual operation of the solid-liquid separation apparatus 100. It is clear from the photograph that the conveyor belt 10 to the right of the roller 30 contains a large amount of water, while the conveyor belt 10 to the left of the roller 30 contains virtually no water, and it can be seen that water is adhering to the roller 30. This phenomenon does not occur with the roller 30 alone, nor does it occur with the pressurized gas supply unit 40 alone, indicating that the combination of the roller 30 and the pressurized gas supply unit 40 is important.

[0035] The roller 30 may be a roller having a metal surface as shown in the photograph of FIG. 3, but may also be a roller having a resin surface.

[0036] The pressurized gas supply unit 40 blows strong air from above onto the portion of the conveyor belt 10 supported by the rollers 30, thereby moving the moisture contained in the liquid-permeable conveyor belt 10 to the back side of the conveyor belt 10. As a result, the water contained in the conveyor belt 10 is discharged through the rollers 30.

[0037] The pressurized gas supply unit 40 can blow out gas at any pressure, for example, 0.1 to 1.0 MPa, 0.2 to 0.8 MPa, or 0.3 to 0.7 MPa, although the gas strength is not limited as long as it can move the moisture contained in the liquid-permeable conveyor belt 10 to the back side of the conveyor belt 10.

[0038] The pressurized gas supply unit 40 is preferably configured to supply pressurized gas as close as possible to the conveyor belt 10. For example, the pressurized gas supply unit 40 is preferably located within 10 cm from the conveyor belt 10. The closer the distance, the more moisture on the conveyor belt 10 can be moved to the back side of the conveyor belt 10, so this distance is preferably within 5 cm, 3 cm, or 1 cm. Here, the distance between the conveyor belt 10 and the pressurized gas supply unit 40 refers to the average distance from the surface of the conveyor belt 10 to the pressurized gas outlet of the pressurized gas supply unit 40.

[0039] The pressurized gas supply unit 40 is preferably configured to supply pressurized gas over substantially the entire width direction perpendicular to the traveling direction of the conveyor belt 10. Here, substantially the entire width direction may be substantially the same as the width of the range in which the solid and liquid supplied from the solid-liquid supply unit 20 are placed on the conveyor belt 10, and if a cover 21 is present, may be substantially the same as the dimension of the cover 21 in the width direction (the same report as the width direction of the conveyor belt 10).

[0040] The pressurized gas supplied from the pressurized gas supply unit 40 is preferably delivered from above directly below the conveyor belt 10. The angle between the conveying direction of the conveyor belt 10 and the direction in which the pressurized gas is delivered is preferably 60 to 120 degrees or 80 to 100 degrees, and most preferably about 90 degrees, or a nearly right angle.

[0041] It is preferable that the device 100 is provided with two or more combinations of rollers 30 and pressurized gas supply units 40. This allows more moisture to be removed from the conveyor belt 10 compared to a case where only one combination of rollers 30 and pressurized gas supply units 40 is provided. For example, three or more combinations of rollers 30 and pressurized gas supply units 40 may be provided as shown in FIG.

[0042] The recovery section 50 is located downstream of the roller 30 and the pressurized gas supply section 40 in the conveying direction of the conveyor belt 10. In the vicinity of the recovery section 50, moisture is discharged from the conveyor belt 10, making it easy to recover solids from the conveyor belt 10.

[0043] The collecting section 50 may be located at the end of the conveyor-type transfer belt 10 and be capable of collecting solids that drop from the transfer belt 10.

[0044] In this case, it is preferable that the end of the conveyor belt 10 is folded back at an acute angle as shown in Fig. 1. In this case, the recovery unit 50 can be located below the end of the conveyor belt 10 as shown in Fig. 1.

[0045] Figure 4 is a photograph of semiconductor wafer scraps that have been transported to the end of the conveyor belt 10. At this stage, a large amount of water has been discharged from the conveyor belt 10, so the semiconductor wafer scraps fall directly onto the conveyor belt 10 and can be collected in the collection section 50.

[0046] However, even with this, some of the semiconductor wafer scraps may continue to adhere to the conveyor belt 10. For this reason, the apparatus 100 of the present invention may further include a pressurized gas supply unit 60 for solid separation on the back side of the conveyor belt 10. This allows the supply of pressurized gas when a solid does not separate from the conveyor belt 10, thereby separating the solid from the conveyor belt 10. FIG. 5 is a photograph of the pressurized gas supply unit 60 for solid separation located on the back side of the conveyor belt 10.

[0047] Similarly, the apparatus 100 may further include a second pressurized gas supply unit 61 for solid separation that supplies pressurized gas from the front side of the conveyor belt 10 .

[0048] Similar to the pressurized gas supply unit 40, the solid peeling pressurized gas supply unit 60 and the second solid peeling pressurized gas supply unit 61 can have the distance from the conveyor belt, the gas discharge pressure, and the like.

[0049] Furthermore, this apparatus 100 can have a solid recovery baffle plate 70 downstream of the solid peeling pressurized gas supply unit 60. This makes it possible to recover the last solids adhering to the conveyor belt 10. By taking these measures, it is possible to recover 95% or more, particularly 98% or more, of the solids discharged onto the conveyor belt 10, even if they are extremely difficult to recover, such as semiconductor wafer scraps. [Explanation of symbols]

[0050] 10...Conveyor belt 20...Solid-liquid supply section 21...Cover 30...Laura 40...Pressurized gas supply unit 50...Collection section 60...Pressurized gas supply unit for solid peeling 61...Second solid peeling pressurized gas supply unit 70...Solid recovery baffle 80...Waste liquid collection section 100...Solid-liquid separation equipment

Claims

1. Liquid-permeable conveyor belt, a solid-liquid supplying section that supplies a liquid containing a solid onto the conveyor belt; a roller positioned downstream of the solid-liquid supply unit in the conveying direction of the conveyor belt and supporting the conveyor belt from below; a pressurized gas supply unit that supplies pressurized gas to the portion of the conveyor belt supported by the roller; and a recovery section for the solid material, the recovery section being located downstream of the roller in the conveying direction of the conveyor belt; A solid-liquid separation device comprising:

2. The solid-liquid separator according to claim 1 , wherein the conveyor belt is made of a metal mesh.

3. The solid-liquid separator according to claim 1 , wherein the pressurized gas supply unit is located within 10 cm of the conveyor belt.

4. The solid-liquid separator according to claim 3 , wherein the pressurized gas supply unit supplies the pressurized gas over substantially the entire width of the conveyor belt.

5. The solid-liquid separation device according to claim 1 , comprising two or more combinations of the pressurized gas supply unit and the roller.

6. 2. The solid-liquid separator according to claim 1, wherein the conveyor belt is folded back at an acute angle at an end thereof, and the recovery section is located below the end of the conveyor belt.

7. 7. The solid-liquid separator according to claim 6, further comprising a pressurized gas supply section for solid separation on the back side of the conveyor belt folded back at an acute angle.

8. 8. The solid-liquid separator according to claim 7, further comprising a baffle plate for recovering solids downstream of the pressurized gas supply unit for separating solids in the conveying direction of the conveyor belt.

9. 2. The solid-liquid separator according to claim 1, which is an apparatus for separating semiconductor wafer scraps from water.

10. A solid-liquid separation method comprising separating semiconductor wafer scraps from water using the solid-liquid separation device according to any one of claims 1 to 8.

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