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

Abstract

The present invention provides a solid-liquid separation device that can easily separate and recover solids contained in liquid, such as semiconductor wafer scraps, in a fully automated manner. [Solution] The solid-liquid separation device 100 of the present invention comprises a liquid-permeable conveyor belt 10; a solid-liquid supplying section 20 that supplies a liquid containing solids onto the conveyor belt 10; a roller 30 that is located downstream of the solid-liquid supplying section 20 in the conveying direction of the conveyor belt 10 and supports the conveyor belt 10 from below; a pressurized gas supplying section 40 that supplies pressurized gas to the portion of the conveyor belt 10 supported by the roller 30; and a solid recovery section 50 that is located downstream of the roller 30 in the conveying direction of the conveyor belt 10.

Description

[Technical field]

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

[0002] In the semiconductor manufacturing process, The back surface of the semiconductor wafer is ground by a grinding device to a predetermined thickness, and then the semiconductor wafer is separated into individual devices by a dicing device (cutting device).

[0003] A semiconductor wafer is usually circular, and the circumference 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 of the 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] JP 2010-93004 A Summary of the Invention [Problem to be solved by the invention]

[0006] The scraps of semiconductor wafers collected together with the waste liquid are difficult to handle because they are sharp and can damage resin pipes or filters. In addition, scraps are not always generated in the semiconductor manufacturing process, but are generated only when the dicing process is performed.

[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 decide when to recover the scraps.

[0008] Furthermore, at sites such as metal processing, machining, and plating, highly flat burrs can be generated. Similar to semiconductor wafer scraps, these burrs can also pose issues such as damaging plastic piping with their sharp edges.

[0009] Therefore, an object of the present invention is to provide a solid-liquid separation device that can easily separate and recover solids contained in liquid, such as semiconductor wafer scraps and plate-shaped burrs, in a fully automated manner, and a solid-liquid separation method using the same. [Means for solving the problem]

[0010] The present inventors have found that the above problems can be solved by the present invention, which includes the following embodiments.

[0011] In one embodiment, the solid-liquid separation apparatus of the present invention comprises: Liquid-permeable conveyor belt, a solid-liquid supplying section for supplying 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 for supplying 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; Equipped with:

[0012] In one embodiment, in the solid-liquid separation device of the present invention, the conveyor belt is made of a metal mesh.

[0013] In one embodiment, in the solid-liquid separation device of the present invention, the pressurized gas supply part is located at a distance of 10 cm or less from the conveyor belt.

[0014] In one embodiment, in the solid-liquid separation device of the present invention, the pressurized gas supplying unit supplies the pressurized gas to approximately the entire conveyor belt in the width direction.

[0015] 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.

[0016] 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, and the recovery section is located below the end portion of the conveyor belt.

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

[0019] In one embodiment, the solid-liquid separation device of the present invention has a baffle plate for recovering solids downstream of the solid peeling pressurized gas supply unit in the conveying direction of the conveyor belt.

[0020] In one embodiment, the solid-liquid separation apparatus of the present invention is an apparatus for separating semiconductor wafer scraps from water.

[0021] 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. Effect of the Invention

[0022] According to the present invention, it is possible to provide a solid-liquid separation device and a solid-liquid separation method using the same that can easily separate and recover solids contained in liquid, such as semiconductor wafer scraps and plate-shaped burrs, in a fully automated manner. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 shows a schematic diagram of an apparatus according to the invention. [Diagram 2]FIG. 2 is a photograph of the pressurized gas supply of one embodiment of the device of the present invention. [Diagram 3] FIG. 3 is a photograph of rollers supporting from below the conveyor belt of one embodiment of the device of the present invention. [Figure 4] FIG. 4 is a photograph of the end of a conveyor belt of one embodiment of the device of the present invention. [Diagram 5] FIG. 5 is a photograph of a pressurized gas supply section for peeling solid matter, which is provided on the rear side of the conveyor belt of one embodiment of the apparatus of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present invention will be specifically described using the following embodiments as examples, but the present invention is not limited thereto. Unless otherwise specified in this specification, each device, mechanism, means, etc., a person skilled in the art can use a mechanical device, mechanism, means, etc. that is well known to those skilled in the art. Each embodiment can be combined based on ordinary knowledge by a person skilled in the art, and a configuration that is not specifically described in each embodiment can have the same configuration as other embodiments or a configuration suitable for that embodiment.

[0025] FIG. 1 shows a schematic diagram of one embodiment of the device of the present invention.

[0026] The solid-liquid separation apparatus 100 of the present invention comprises a liquid-permeable conveyor belt 10; a solid-liquid supplying section 20 that supplies a liquid containing solids onto the conveyor belt 10; rollers 30 that are located downstream of the solid-liquid supplying section 20 in the conveying direction of the conveyor belt 10 and support the conveyor belt 10 from below; a pressurized gas supplying 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.

[0027] When attempting to recover solids by supplying a liquid containing solids onto the conveyor belt 10 of the solid-liquid separation device 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, scraps of semiconductor wafers are extremely flat because they have undergone a CMP process, and can adhere strongly to the conveyor belt 10, making removal extremely difficult.

[0028] In response to this, the present inventors tried to blow high-temperature hot air onto the conveyor belt 10 of the solid-liquid separation device 100 to dry the liquid, or to blow air at high pressure to remove the liquid, but the liquid penetrated into the liquid-permeable conveyor belt 10, making it extremely difficult to discharge the liquid from the conveyor belt 10. However, as the present inventors further pursued their studies, they found that when the conveyor belt 10 is supported from below by the rollers 30 and pressurized gas is supplied from above to the location 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 discharged from the conveyor belt 10. Then, with such a solid-liquid separation device 100, since substantially only solids remain on the conveyor belt 10, it was found that even if the solid is difficult to recover, such as a scrap of a semiconductor wafer, only the solid can be easily recovered.

[0029] In this specification, the terms "upper" and "lower" may be interpreted in a general sense with the direction of gravity being the lower side. For example, the terms "upper side" and "upper surface" refer to the surface of the conveyor belt 10 to which the solid-containing liquid is supplied from the solid-liquid supply unit 20. The terms "lower side" and "reverse side" refer to the surface of the conveyor belt 10 opposite to the upper side and the upper surface.

[0030] The conveyor belt 10 is not particularly limited as long as it is liquid-permeable, and may be, for example, a porous belt, and may be, in particular, a mesh belt. The material of the conveyor belt 10 is not particularly limited as long as it is a material for a normal conveyor belt used in a belt conveyor, and may be, for example, a metal, and may be, in particular, stainless steel. As shown in FIG. 2, the conveyor belt 10 may be made of a metal mesh. The conveyor belt 10 may be continuously operated in a circular motion like a belt conveyor so as to be capable of continuous conveyance.

[0031] The solid-liquid supplying section 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, for example, a scrap of a semiconductor wafer. The liquid is not particularly limited and may be water. In addition, in metal processing, machining, plating, and other sites, burrs with high flatness may be generated, and an example of the solid may be a plate-like burr member generated by removing the burr. Similar to the scrap of a semiconductor wafer, these also have the problem of damaging the resin pipes.

[0032] 1 and 2, the solid-liquid supplying unit 20 may further have a cover 21 for preventing the solid and liquid supplied from the solid-liquid supplying unit 20 from scattering from the conveyor belt 10. In addition, the position of the solid falling onto the conveyor belt 10 may be limited to a part of the width of the conveyor belt 10 by using the cover 21, so that the pressurized gas may be supplied from the pressurized gas supplying unit only to that width.

[0033] The rollers 30 support the conveyor belt 10 from below, so that when pressurized gas is supplied, water can move toward the rollers 30. The solid-liquid separation device 100 can be equipped with a plurality of sets of rollers 30 and pressurized gas supply units 40, so that the liquid on the conveyor belt 10 can be reliably discharged toward the rollers 30.

[0034] The liquid discharged to the roller 30 side can be collected by the waste liquid collecting section 80 located at the bottom of the device 100. The waste liquid collecting section 80 is located below the solid-liquid supply section 20, so that the discharged liquid can be widely collected.

[0035] 3 is a photograph of the roller 30 during actual operation of the solid-liquid separation device 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 substantially no water, and water is attached to the roller 30. This phenomenon did not occur with the roller 30 alone, and also did not occur with the pressurized gas supply unit 40 alone, so it was found that the combination of the roller 30 and the pressurized gas supply unit 40 is important.

[0036] 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.

[0037] 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.

[0038] The pressurized gas supply unit 40 can blow out gas at a discharge pressure of, 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.

[0039] It is preferable that the pressurized gas supplying unit 40 is configured to supply the pressurized gas as close as possible to the conveyor belt 10. For example, it is preferable that the pressurized gas supplying unit 40 is located within 10 cm from the conveyor belt 10, and since the closer the distance is, the more moisture on the conveyor belt 10 can be moved to the back side of the conveyor belt 10, it is preferable that the distance is within 5 cm, within 3 cm, or within 1 cm. Here, the distance between the conveyor belt 10 and the pressurized gas supplying unit 40 refers to the average distance from the surface of the conveyor belt 10 to the pressurized gas outlet of the pressurized gas supplying unit 40.

[0040] 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 in the case where 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).

[0041] The pressurized gas supplied from the pressurized gas supply unit 40 is preferably delivered from above to directly below the conveyor belt 10. The conveying direction of the conveyor belt 10 and the direction in which the pressurized gas is delivered preferably form an angle of 60 degrees to 120 degrees or 80 degrees to 100 degrees, and most preferably have a substantially right-angled relationship of about 90 degrees.

[0042] It is preferable that the device 100 is provided with two or more combinations of the roller 30 and the pressurized gas supply unit 40. This allows a larger amount of moisture to be discharged from the conveyor belt 10 compared to a case where there is only one combination of the roller 30 and the pressurized gas supply unit 40. For example, three or more combinations of the roller 30 and the pressurized gas supply unit 40 may be provided as shown in FIG.

[0043] 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.

[0044] The recovery section 50 may be located at an end of the conveyor-type transfer belt 10 and be capable of recovering solids that drop from the transfer belt 10 .

[0045] In this case, it is preferable that the end portion of the conveyor belt 10 is folded back at an acute angle as shown in Fig. 1. In this case, the recovery section 50 can be located below the end portion of the conveyor belt 10 as shown in Fig. 1.

[0046] FIG. 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 to the bottom and can be collected at the collection section 50.

[0047] However, even with this, some of the semiconductor wafer scraps may continue to adhere to the conveyor belt 10. For this reason, the device 100 of the present invention may further include a pressurized gas supply unit 60 for removing solids on the rear side of the conveyor belt 10. This makes it possible to supply pressurized gas to remove solids from the conveyor belt 10 when the solids do not peel off from the conveyor belt 10. FIG. 5 is a photograph of the pressurized gas supply unit 60 for removing solids present on the rear side of the conveyor belt 10.

[0048] Similarly, the apparatus 100 may further include a second solid peeling pressurized gas supply unit 61 that supplies pressurized gas from the front side of the conveyor belt 10 .

[0049] Similarly 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 a distance from the conveyor belt, a gas discharge pressure, and the like.

[0050] Furthermore, the device 100 can have a baffle plate 70 for recovering solids downstream of the pressurized gas supply unit 60 for peeling off solids. This makes it possible to recover solids that remain on the conveyor belt 10 until the very end. 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 scraps of semiconductor wafers. [Explanation of symbols]

[0051] 10...Conveyor belt 20...Solid-liquid supply section 21…Cover 30…Laura 40...Pressurized gas supply section 50…Collection section 60: Pressurized gas supply for solid peeling 61...Second solid peeling pressurized gas supply unit 70...Solid recovery baffle plate 80...Waste liquid recovery section 100...Solid-liquid separation equipment

Claims

1. Liquid-permeable conveyor belt, a solid-liquid supplying section for supplying 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 for supplying 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; wherein the solid is a plate-shaped burr member.

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

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

4. The solid-liquid separation apparatus according to claim 3 , wherein the pressurized gas supplying unit supplies the pressurized gas to an area where the solid and liquid supplied from the solid-liquid supplying unit are placed on the conveyor belt.

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

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

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

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

9. 2. The solid-liquid separation apparatus according to claim 1, which is an apparatus for separating plate-shaped burrs from water.

10. A solid-liquid separation method comprising separating a plate-shaped burr member from water using the solid-liquid separation device according to any one of claims 1 to 8.

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