JP6000119B2 - Processing waste liquid treatment equipment - Google Patents

Description

  The present invention relates to a processing waste liquid processing apparatus that is attached to a processing apparatus and processes processing waste liquid generated by processing.

  For example, in a semiconductor device manufacturing process, a plurality of circuit elements such as ICs and LSIs are formed on the surface of a semiconductor wafer, and then the back surface of the wafer is ground with a grinding device to a predetermined thickness, and the thinned wafer is cut. Individual semiconductor devices are manufactured by cutting with an apparatus.

  In these grinding devices and cutting devices, processing is performed while supplying processing water for the purpose of removing processing waste generated by processing, the purpose of cooling processing heat generated by processing, and the like. Even if a very small amount of impurities remain on the semiconductor device, the quality of the semiconductor device is seriously affected. For this reason, pure water is also used as processing water in these grinding apparatuses and cutting apparatuses.

  Pure water is generated by passing city water through a filter, an activated carbon filter, an ion exchange resin, or a reverse osmosis membrane. For example, the pure water is generated using a pure water production apparatus as disclosed in JP-A-9-29245. The

  Since pure water is generally expensive, the used pure water used in the processing apparatus or the like is collected and recycled for use. However, a large amount of processing waste is mixed in the used pure water used in the processing equipment, and when these processing waste is removed and pure water is generated again, the filter or ion of the pure water production equipment is used. There is a problem that exchange resins, reverse osmosis membranes and the like are clogged immediately.

  In view of this, the present applicant has disclosed a processing waste liquid treatment apparatus that removes processing waste from the processing waste liquid by filtering the processing waste liquid generated by the processing with a filter in order to assist the generation of pure water in these pure water production apparatuses. Proposed in Japanese Patent Publication No. 2009-95941.

  This processing waste liquid treatment apparatus includes two filters, and even when one filter is clogged, the processing waste liquid is supplied to the other filter to continuously perform a filtering operation. An operator replaces the clogged filter with a new one.

  In the processing waste liquid treatment apparatus disclosed in Japanese Patent Application Laid-Open No. 2009-95941, the processing waste liquid fed to the filtering means passes through the filtering means, whereby the fine particle powder introduced into the filter paper adheres to the inner surface of the filter paper. By filtering the processing waste liquid by the fine particle powder and the filter paper, it is possible to reliably separate the processing waste contained in the processing waste liquid even with a relatively coarse filter paper.

JP 2009-95941 A JP 2009-190128 A

  However, in the new filtration means, it is necessary that the processing waste liquid once fed before the fine particle powder adheres to the inner surface of the filter paper, and before the fine particle powder sufficiently adheres to the inner surface of the filter paper. In addition, the degree of filtration is inferior to the state in which the fine particle powder is sufficiently adhered to the inner surface of the filter paper, and the processing waste may not be sufficiently separated.

  The present invention has been made in view of these points, and the object of the present invention is to provide a processing waste liquid that stores only fresh water from which processing waste has been sufficiently separated even in a new filtering means in a fresh water tank. It is to provide a processing device.

  According to the present invention, a processing waste liquid treatment apparatus that is attached to a processing apparatus and processes the processing waste liquid generated in the processing apparatus, the waste liquid tank that stores the processing waste liquid generated in the processing apparatus, and the waste liquid tank that is stored in the waste liquid tank A pump for feeding processing waste liquid, a cylindrical filter paper for filtering the processing waste liquid fed by the pump, a cylindrical body covering the outer periphery of the cylindrical filter paper and having a plurality of openings on the side surface, and the cylindrical filter paper A bottom plate that closes the lower end of the cylindrical filter paper, a top plate that closes the upper end of the cylindrical filter paper and has a waste liquid inlet for introducing processing waste liquid fed by the pump, and fine particle powder charged into the cylindrical filter paper A fresh water receiving portion that receives the liquid filtered by the filtering means, a fresh water tank that stores fresh water that has flowed out of the fresh water receiving portion, and one end that is selective to the fresh water receiving portion. And the other end is connected to the fresh water tank. A first outflow path, a second outflow path having one end selectively connected to the fresh water receiving portion and the other end connected to the waste liquid tank, and a second outflow path disposed on the second outflow path. Turbidity detection means for detecting the turbidity of the liquid flowing through the water, switching means for switching the connection of the first outflow path and the second outflow path to the fresh water receiving portion, and one end of the second outflow path When the turbidity of the liquid flowing through the second outflow passage detected by the turbidity detecting means in a state connected to the fresh water receiving portion becomes below a predetermined value, the switching means is operated to operate the second outflow There is provided a processing waste liquid treatment apparatus comprising: a control means for cutting off the connection of the passage to the fresh water receiving portion and connecting one end of the first outflow passage to the fresh water receiving portion.

  Preferably, the fresh water receiving portion is connected to one end of the first outflow passage to discharge the liquid to the fresh water tank, and connected to one end of the second outflow passage to supply the liquid. A second drainage hole for discharging to the waste liquid tank is formed, and the drainage surface of the first drainage hole is formed above the drainage surface of the second drainage hole.

  Preferably, when the supply of the processing waste liquid from the pump to the filtering unit is stopped, the control unit operates the switching unit to cut off the connection of the first outflow path to the fresh water receiving portion. At the same time, one end of the second outflow passage is connected to the fresh water receiving portion.

  When the turbidity detected by the turbidity detecting means is not more than a predetermined value, the processing waste liquid treatment apparatus of the present invention cuts off the connection of the second outflow passage to the fresh water receiving portion and passes the first outflow passage through the clear water. Connect to the receiver. That is, when the fine particle powder is not sufficiently adhered to the inner surface of the filter paper and the liquid filtered by the filtering means contains processing waste, the liquid filtered by the filtering means flows out to the waste liquid tank.

  When the liquid filtered by the filtering means becomes below a predetermined turbidity, the liquid filtered by the filtering means is discharged to the fresh water tank for the first time. Therefore, processing waste does not enter the fresh water tank, and only fresh water from which the processing waste has been sufficiently separated is stored in the fresh water tank.

  When the second drainage hole leading to the drainage tank is formed on the lower surface than the first drainage hole leading to the fresh water tank as in claim 2, filtration is performed when filtration by the filtering means is insufficient. Impurities flowing out from the means can be retained in the fresh water receiving portion without flowing out into the fresh water tank through the first drain hole.

  If the liquid containing processing waste accidentally flows out into the fresh water tank, there is a problem that the inside of the fresh water tank is contaminated. However, the drainage surface of the first drainage hole is higher than the drainage surface of the second drainage hole. Since it is formed, the processing waste is prevented from flowing into the fresh water tank.

It is an external appearance perspective view of a processing waste liquid processing apparatus. It is a disassembled perspective view of a processing waste liquid processing apparatus. It is a block diagram of the configuration of the processing waste liquid treatment apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, an external perspective view of a processing waste liquid treatment apparatus 2 according to an embodiment of the present invention is shown. FIG. 2 is an exploded perspective view of the processing waste liquid treatment apparatus of FIG.

  The processing waste liquid treatment apparatus 2 is fed by a waste liquid tank 4 for storing the processing waste liquid, a fresh water tank 5 for storing the fresh water, a pump 6 for feeding the processing waste liquid stored in the waste liquid tank 4, and the pump 6. A filtering means 44 is provided for filtering the processing waste liquid. The waste liquid tank 4 has a processing waste liquid return port 4a on the upper wall, and the fresh water tank 5 has a fresh water inlet 5a on the upper wall.

  The waste liquid tank 4 includes a waste liquid inlet 10 on an end wall, and the waste liquid inlet 10 is connected to a processing waste liquid outlet of a processing apparatus such as a cutting apparatus (not shown). A pump 6 for supplying processing waste liquid to the upper wall of the waste liquid tank 4 is disposed. The waste liquid tank 4 and the fresh water tank 5 are disposed on the upper surface of the support base 12.

  The filtering means 44 includes a first filter unit 8 a and a second filter unit 8 b for filtering the processing waste liquid fed by the pump 6. The first filter unit 8 a and the second filter unit 8 b each block a filter paper (cylindrical filter paper) 14 formed in a cylindrical shape, a cylindrical body 16 covering the outer periphery of the filter paper 14, and a lower end of the cylindrical filter paper 14. It consists of a bottom plate 18 and a top plate 20 that closes the upper end of the cylindrical filter paper 14.

  The cylindrical filter paper 14 is formed by being radially folded and configured to increase the filtration area. As the cylindrical filter paper 14, for example, a relatively inexpensive filter paper having a large mesh size through which particles having a particle size of 0.3 to 0.4 μm or less can pass is used. A fine particle powder 15 such as silica is put in a cylindrical filter paper 14.

  The cylindrical body 16 that covers the outer periphery of the cylindrical filter paper 14 has a plurality of openings 17 on the side surface. The top plate 20 that closes the upper end of the cylindrical filter paper 14 is provided with a waste liquid inlet 22 at the center.

  The first filter unit 8 a and the second filter unit 8 b configured as described above are disposed on a filter rack 24 disposed on the upper side of the waste liquid tank 4 disposed on the support base 12.

  The filter rack 24 includes a rectangular bottom wall 26, side walls 28 and 30 erected from both side surfaces of the bottom wall 26, and end walls 32 and 34 erected from both ends of the bottom wall 26. It is configured, is supported by four support columns 36, and is disposed on the upper side of the waste liquid tank 4 disposed on the support base 12.

  The filter rack 24 is a filtered processing liquid (fresh water) from which processing waste is separated by the first filter unit 8a and the second filter unit 8b by the bottom wall 26, the side walls 28 and 30, and the end walls 32 and 34. The fresh water receiving part 38 to accommodate is formed.

  A first drain hole 40 and a second drain hole 41 are formed in the bottom wall 26 of the filter rack 24, that is, the fresh water receiving portion 38. As best shown in FIG. 3, the drainage surface of the first drainage hole 40 is formed above the drainage surface of the second drainage hole 41.

  The first drain hole 40 is connected to the fresh water inlet 5a of the fresh water tank 5 through the first outflow path 40a. The second drain hole 41 is connected to the processing waste liquid return port 4a of the drain tank 4 via the second outflow passage 41a.

  Turbidity detecting means 43 is disposed in the second outflow passage 41a. The turbidity detecting means 43 is connected to the controller 54. 47 is a switching means comprising a plug 43 and an air cylinder 45 connected to the plug 43. By selectively closing the second drainage hole 41, fresh water is received by the first outflow path 40a and the second outflow path 41a. The connection to the unit 38 is switched.

  A first support base 42 a and a second support base 42 b for supporting the first filter unit 8 a and the second filter unit 8 b are disposed on the bottom wall 26 of the filter rack 24. The first filter unit 8a is placed on the first support base 42a, and the second filter unit 8b is placed on the second support base 42b.

  As shown in FIG. 3, the filtering means 44 includes a first filter and a first filter unit 8 a and 8 b that are detachably disposed, and a feed destination to which the processing waste liquid is fed by the feed pump 6. A switching valve (switching means) 46 for selectively switching between the unit 8a and the second filter unit 8b, a first pressure detecting means 48a for detecting the pressure of the processing waste liquid fed to the first filter unit 8a, Second pressure detecting means 48b for detecting the pressure of the processing waste liquid fed to the second filter unit 8b is included.

  The switching valve 46 is composed of an electromagnetic switching valve. When the switching valve 46 is off, communication between the pipe 50, the pipe 50a, and the pipe 50b is interrupted, and when one electromagnetic coil 52a is excited (turned on), the pipe 50 and the pipe 50a communicate with each other and when the other electromagnetic coil 52b is excited (turned on), the pipe 50 and the pipe 50b communicate with each other.

  The pipe 50a is provided with first pressure detecting means 48a for detecting the pressure of the processing waste liquid supplied to the first filter unit 8a, and the pipe 50b is provided with the processing waste liquid supplied to the second filter unit 8b. The second pressure detecting means 48b for detecting the pressure is provided. The pressure detected by the first pressure detection means 48 a and the pressure detected by the second pressure detection means 48 b are sent to the controller 54.

  Hereinafter, the operation of the above-described processing waste liquid treatment apparatus 2 will be described. When processing the processing waste liquid stored in the waste liquid tank 4, the controller 54 first operates the pump 6, and the switching control unit 56 of the controller 54 excites (turns on) one electromagnetic coil 52 a of the electromagnetic switching valve 46. . As a result, the processing waste liquid fed by the pump 6 is introduced into the first filter unit 8 a via the pipe 50, the electromagnetic switching valve 46, the pipe 50 a and the waste liquid inlet 22.

  The processing waste liquid introduced into the first filter unit 8 a is filtered by the cylindrical filter paper 14, but when the first filter unit 8 a is new, the charged particulate powder 15 is sufficiently adhered to the inner surface of the filter paper 14. Not done.

  Before the fine particle powder 15 adheres to the inner surface of the filter paper 14, it is necessary for the processing waste liquid once supplied to pass through the first filter unit 8 a, compared to a state where the fine particle powder 15 is sufficiently adhered to the inner surface of the filter paper 14. Therefore, the degree of filtration is poor, and there is a risk that the processing waste cannot be separated sufficiently.

  The processing waste liquid filtered by the filter paper 14 flows out to the fresh water receiving portion 38 of the filter rack 24 through a plurality of openings 17 formed on the side surface of the cylindrical body 16 covering the outer periphery of the filter paper 14. The processing waste liquid that has flowed out into the fresh water receiving portion 38 falls into the waste liquid tank 4 from the processing waste liquid return port 4a of the drainage tank 4 via the second drain hole 41 and the second outflow passage 41a, and enters the waste liquid tank 4. Be contained.

  Since the second outflow passage 41 a is provided with the turbidity detecting means 49, the turbidity in the waste liquid is detected by the turbidity detecting means 49. As described above, when the first filter unit 8a is new, the fine particle powder 15 is not sufficiently adhered to the inner surface of the filter paper 14, so that the degree of filtration is smaller than the state in which the fine particle powder 15 is adhered to the inner surface of the filter paper 14. Is inferior.

  Therefore, in the initial state of operation of the processing waste liquid treatment apparatus 2, the processing waste liquid that has fallen into the fresh water receiving portion 38 is accommodated in the drainage tank 4 through the second drain hole 41. When the filtering operation is continued with the first filter unit 8 a, the fine particle powder 15 is sufficiently adhered to the inner surface of the filter paper 14. Therefore, the processing waste liquid filtered by the filter paper 14 is close to fresh water.

  Therefore, when the turbidity detecting means 49 provided in the second outflow passage 41a detects that the turbidity of the processing waste liquid has become a predetermined value or less, the controller 54 operates the switching means 47, and the second outflow passage 41a. The connection to the fresh water receiving portion 38 is cut off. That is, the air cylinder 45 is driven and the plug 43 closes the second drain hole 41.

  As a result, the fresh water filtered by the first filter unit 8a accumulates in the fresh water receiving portion 38. When the level of the fresh water rises to the level of drainage of the first drainage hole 40, the fresh water stored in the fresh water receiving part 38 passes through the first drainage hole 40, the first outlet channel 40a, and the fresh water inlet 5a. It falls into the tank 5 and is accommodated in the fresh water tank 5.

  The fresh water accommodated in the fresh water tank 5 is discharged from a fresh water discharge port (not shown) and recirculated by a processing liquid supply means provided in a processing apparatus (not shown) or discarded through a disposal means.

  When the processing waste liquid is processed by the first filter unit 8a as described above, processing waste accumulates inside the cylindrical filter paper 14 of the first filter unit 8a. If processing waste accumulates inside the filter paper 14, the processing liquid will not easily pass through the tubular filter paper 14, and the function as a filter will be lost.

  When processing waste accumulates inside the cylindrical filter paper 14, the pressure in the cylindrical filter paper 14, that is, the pressure in the pipe 50a increases. Therefore, when the pressure in the pipe 50a detected by the first pressure detection means 48a reaches a predetermined value set in advance, for example, 2 atm, the controller 54 determines that the first filter unit 8a is clogged.

  Then, the switching control unit 56 of the controller 54 excites (turns on) the electromagnetic coil 52b of the electromagnetic switching valve 46, moves the spool of the electromagnetic switching valve 46 leftward, and connects the pipe 50 to the pipe 50b. As a result, the processing waste liquid fed by the pump 6 is introduced into the second filter unit 8b through the pipe 50, the electromagnetic switching valve 46, the pipe 50b, and the processing waste liquid inlet 22.

  When the pressure in the pipe 50a exceeds a predetermined value, warning means connected to the controller 54 issues a warning and prompts the operator to replace the first filter unit 8a. This warning can be performed by lighting a lamp or a buzzer.

  While filtering the processing waste liquid with the second filter unit 8b, the operator replaces the first filter unit 8a with a new filter unit. During this time, the processing of the processing waste liquid is performed by the second filter unit 8b, so that it is not necessary to interrupt the processing apparatus.

  Simultaneously with the switching of the electromagnetic switching valve 46, the controller 54 operates the switching means 47 to pull out the plug 43 from the second drain hole 41 and connect the closed second outflow path 41 a to the fresh water receiving portion 38.

  The processing waste liquid introduced into the second filter unit 8b is filtered by the cylindrical filter paper 14 and passed through the openings 17 formed on the side surface of the cylindrical body 16 covering the outer periphery of the filter paper 14 to the fresh water receiving portion 38 of the filter rack 24. leak.

  At this time, since the second filter unit 8b is new, the fine particle powder 15 is not sufficiently adhered to the inner surface of the filter paper. Therefore, the processing waste liquid discharged to the fresh water receiving portion 38 at the initial filtration stage of the second filter unit 8b has a poor filtration degree. This processing waste liquid falls into the drainage tank 4 through the second drainage hole 41, the second outflow passage 41a, and the processing waste liquid return port 4a and is stored in the drainage tank 4.

  When the turbidity detecting means 49 disposed in the second outflow passage 41a detects turbidity below a predetermined value, the plug 43 of the switching means 47 closes the second drainage hole 41. Therefore, when the fresh water stored in the fresh water receiving portion 38 rises to the drainage surface (upper end) of the first drainage hole 40, the fresh water stored in the fresh water receiving portion 38 is discharged into the first drainage hole 40, the first outflow. It falls into the fresh water tank 5 through the path 40a and the fresh water inlet 5a and is accommodated in the fresh water tank 5.

  Similarly to the switching of the electromagnetic switching valve 46, when the supply of the processing waste liquid from the pump 6 to the filtering means 44 is stopped, the controller 54 operates the switching means 47 so that the plug 43 is connected to the second drain hole 41. The second outflow passage 41 a that has been pulled out and closed is connected to the fresh water receiving portion 38.

2 Processing Waste Liquid Treatment Device 4 Waste Liquid Tank 5 Fresh Water Tank 6 Pump 8a First Filter Unit 8b Second Filter Unit 14 Cylindrical Filter Paper 15 Fine Particle Powder 24 Filter Rack 40 First Drain Hole 40a First Outflow Path 41 Second Drain Hole 41a Second outflow passage 44 Filtration means 46 Electromagnetic switching valve 47 Switching means 49 Turbidity detection means 54 Controller

Claims (3)

A processing waste liquid treatment apparatus attached to a processing apparatus for processing a processing waste liquid generated in the processing apparatus,
A waste liquid tank for storing processing waste liquid generated in the processing apparatus;
A pump for feeding processing waste liquid stored in the waste liquid tank;
A cylindrical filter paper for filtering the processing waste liquid fed by the pump, a cylindrical body covering the outer periphery of the cylindrical filter paper and having a plurality of openings on the side surface, a bottom plate for closing the lower end of the cylindrical filter paper, A top plate having a waste liquid inlet for closing the upper end of the cylindrical filter paper and introducing the processing waste liquid fed by the pump; and a fine particle powder charged into the cylindrical filter paper; ,
A fresh water receiving portion for receiving the liquid filtered by the filtering means;
A fresh water tank for storing fresh water discharged from the fresh water receiving portion;
A first outflow passage having one end selectively connected to the fresh water receiving portion and the other end connected to the fresh water tank;
A second outflow passage having one end selectively connected to the fresh water receiving portion and the other end connected to the waste liquid tank;
Turbidity detection means for detecting the turbidity of the liquid disposed on the second outflow path and flowing in the second outflow path;
Switching means for switching the connection of the first outflow path and the second outflow path to the fresh water receiving portion;
When the turbidity of the liquid flowing through the second outflow passage detected by the turbidity detecting means is not more than a predetermined value with one end of the second outflow passage connected to the fresh water receiving portion, the switching is performed. A control means for operating the means to cut off the connection of the second outflow path to the fresh water receiving section and to connect one end of the first outflow path to the fresh water receiving section;
A processing waste liquid treatment apparatus characterized by comprising: The fresh water receiving portion is connected to one end of the first outflow passage to discharge the liquid to the fresh water tank, and connected to one end of the second outflow passage to send the liquid to the waste liquid tank. A second drainage hole is formed to discharge to
2. The processing waste liquid treatment apparatus according to claim 1, wherein the drainage surface of the first drainage hole is formed above the drainage surface of the second drainage hole.   The control means operates the switching means to shut off the connection to the fresh water receiving portion of the first outflow path when the supply of the processing waste liquid from the pump to the filtration means is stopped, The processing waste liquid treatment apparatus according to claim 1 or 2, wherein one end of the second outflow passage is connected to the fresh water receiving portion.

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