Pure water generation device

Abstract

To provide a pure water production device which solves a problem of having to frequently replace a precision filter.SOLUTION: A pure water production device comprises at least: a drainage tank 21 which reserves drainage; a filtration part 22 which filters the drainage sent out of the drainage tank 21; a clear water tank 23 which reserves clear water produced by the filtration part 22; an ultraviolet irradiation part 24 which irradiates the clear water sent out of the clear water tank 23 with ultraviolet light to destroy organic matter; an ion-exchange resin part 25 which purifies the clear water sent out of the ultraviolet irradiation part 24 into pure water; a precision filter part 26 which filters the pure water purified by the ion-exchange resin part 25 with high precision; and a pure water supplying channel which is connected to the precision filter part 26 to supply the pure water filtered in the precision filter part 26 to a processing device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pure water generating apparatus for generating pure water from wastewater. [Background technology]

[0002] A wafer has a number of devices such as ICs and LSIs formed on its front surface, separated by planned dividing lines. The back surface is ground by a grinding machine to form the wafer into the desired thickness. The wafer is then divided into individual device chips by a dicing machine for use in electrical devices such as mobile phones and personal computers.

[0003] Since grinding equipment and dicing equipment use pure water as processing water, the applicant has already developed and proposed a pure water generating device that generates and circulates pure water from contaminated wastewater discharged from processing equipment (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-214193 A Summary of the Invention [Problem to be solved by the invention]

[0005] The pure water generating apparatus described in the above-mentioned Patent Document 1 is configured to include at least a drainage tank for storing wastewater, a filtration section for filtering the wastewater discharged from the drainage tank, a fresh water tank for storing fresh water purified by the filtration section, an ultraviolet irradiation section for irradiating the fresh water discharged from the fresh water tank with ultraviolet rays to destroy organic matter, an ion exchange resin section for purifying the fresh water discharged from the ultraviolet irradiation section into pure water, a precision filter section for filtering the pure water purified by the ion exchange resin section, and a pure water supply path for supplying the pure water discharged from the precision filter section to a processing device.

[0006] However, when wastewater exceeding the allowable amount is fed into the above-mentioned pure water generating apparatus, the wastewater that is not sufficiently filtered by the filtration section passes through the ion exchange resin section and reaches the precision filter section, which necessitates frequent replacement of the relatively expensive precision filter, which is uneconomical.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its main technical object is to provide a pure water generating apparatus which eliminates the problem of having to frequently replace the precision filter portion. [Means for solving the problem]

[0008] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a pure water generating device which generates pure water from wastewater discharged from a processing device and supplies the pure water to the processing device, the pure water generating device comprising: a wastewater tank which stores wastewater; a filtration section which filters the wastewater discharged from the wastewater tank; a fresh water tank which stores fresh water generated by the filtration section; an ultraviolet irradiation section which irradiates ultraviolet light onto the fresh water discharged from the fresh water tank to destroy organic matter; an ion exchange resin section which purifies the fresh water discharged from the ultraviolet irradiation section into pure water; a precision filter section which filters the pure water purified by the ion exchange resin section with high precision; and a filter section connected to the precision filter section which filters the pure water filtered by the precision filter section. and a pure water supply channel for supplying the pure water to the processing device, the pure water supply channel being provided with a pure water supply channel valve for opening and closing the pure water supply channel, a waste water drain being connected to a bottom of the precision filter section, and a waste water drain valve for opening and closing the waste water drain being provided in the waste water drain, the pure water supply channel valve being opened when pure water is generated from waste water discharged from the processing device and supplied to the processing device, and closed when the precision filter section is washed, and the waste water drain valve being closed when pure water is generated from waste water discharged from the processing device and supplied to the processing device, and opened when the precision filter section is washed. When the precision filter section is to be washed, the pure water that has passed through the fresh water tank, the ultraviolet ray irradiation section, and the ion exchange resin section is introduced into the precision filter section while the drain valve is opened. A pure water generating apparatus is provided. Effect of the Invention

[0009] The pure water generating apparatus of the present invention includes at least a drainage tank for storing wastewater, a filtration section for filtering the wastewater discharged from the drainage tank, a fresh water tank for storing fresh water generated by the filtration section, an ultraviolet irradiation section for irradiating the fresh water discharged from the fresh water tank with ultraviolet light to destroy organic matter, an ion exchange resin section for purifying the fresh water discharged from the ultraviolet irradiation section into pure water, a precision filter section for filtering the pure water purified by the ion exchange resin section with high precision, and a pure water supply line connected to the precision filter section for supplying the pure water filtered by the precision filter section to a processing device, A pure water supply channel valve for opening and closing the pure water supply channel is disposed in the water supply channel, a waste water drain is connected to the bottom of the precision filter section, and a waste water drain valve for opening and closing the waste water drain is disposed in the waste water drain, the pure water supply channel valve is opened when pure water is generated from waste water discharged from a processing device and supplied to the processing device, and closed when the precision filter section is washed, and the waste water drain valve is closed when pure water is generated from waste water discharged from a processing device and supplied to the processing device, and opened when the precision filter section is washed. When the precision filter section is to be washed, the pure water that has passed through the fresh water tank, the ultraviolet ray irradiation section, and the ion exchange resin section is introduced into the precision filter section while the drain valve is opened. Therefore, the precision filter portion can be washed periodically or at any timing, and frequent replacement of the precision filter portion is no longer necessary, which solves the problem of wastefulness. [Brief description of the drawings]

[0010] [Figure 1] 1 is an overall perspective view of a pure water generating apparatus and a dicing apparatus according to an embodiment of the present invention; [Diagram 2] 2 is an exploded perspective view showing a schematic configuration accommodated in the pure water generating apparatus shown in FIG. 1. [Diagram 3] FIG. 3(a) is a cross-sectional view showing a state in which the precision filter unit shown in FIG. 2 is normally used, and FIG. 3(b) is a cross-sectional view showing a state in which the precision filter unit is used during cleaning. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a pure water generating apparatus constructed based on the present invention will be described in detail with reference to the accompanying drawings.

[0012] FIG. 1 shows an example in which a pure water generating device 20 of this embodiment is applied to a known dicing device 1.

[0013] The dicing device 1 includes a substantially rectangular parallelepiped device housing 2, a chuck table mechanism 3 for holding a wafer 12, which is a workpiece, and a cutting means 4 equipped with a cutting blade 41 for cutting the wafer 12 held by the chuck table mechanism 3. The dicing device 1 includes a cassette 5 (indicated by a two-dot chain line) for accommodating a plurality of wafers 12, a temporary placement table 6 for carrying out and temporarily placing the wafers 12 accommodated in the cassette 5, a carrying in / out means 7 for carrying out the wafers 12 to the temporary placement table 6, a transport means 8 for rotating and transporting the wafers 12 carried out to the temporary placement table 6 onto the chuck table mechanism 3, a cleaning means 9 (details of which are omitted) for cleaning the wafers cut by the cutting means 4, a cleaning transport means 10 for transporting the cut wafers 12 from the chuck table mechanism 3 to the cleaning means 9, an imaging means 11 for imaging the wafers 12 on the chuck table mechanism 3, and a control means (not shown). The cassette 5 is placed on a cassette table 5a arranged so as to be movable up and down by a lifting means (not shown), and when the wafer 12 is removed from the cassette 5 by the loading / unloading means 7, the height of the cassette 5 is appropriately adjusted.

[0014] The device housing 2 is provided with an X-axis feed means (not shown) for moving the chuck table 30 disposed on the chuck table mechanism 3 in the X-axis direction indicated by the arrow X, which is the cutting feed direction, a Y-axis feed means (not shown) for moving the cutting means 4 in the Y-axis direction indicated by the arrow Y perpendicular to the X-axis direction, and a Z-axis feed means (not shown) for moving the cutting means 4 in the Z-axis direction indicated by the arrow Z perpendicular to the X-axis direction and the Y-axis direction. The cutting means 4 is provided with a cutting water supply nozzle 42 for supplying pure water (cutting water) to the cutting site when cutting the wafer held by suction on the chuck table 30.

[0015] The cutting water supplied from the cutting supply nozzle 42 is supplied to the cutting position when cutting is performed, and then collected by a collection path (not shown) arranged in the dicing apparatus 1, and sent as wastewater L1 from the apparatus housing 2 to the pure water generator 20 arranged adjacently via a path 101. The wastewater L1 sent to the pure water generator 20 is purified by the pure water generator 20 to pure water L8, and is introduced again into the dicing apparatus 1 via a path 108 as cutting water.

[0016] The pure water generating apparatus 20 will be described in more detail with reference to Fig. 2 in addition to Fig. 1. Fig. 2 shows a perspective view of the schematic configuration of the pure water generating apparatus 20 housed inside a housing 20A.

[0017] As shown in FIG. 2, the pure water generating apparatus 20 includes at least a drainage tank 21 for storing drainage water L1 discharged from the dicing apparatus 1 via a path 101, a filtration section 22 for filtering and purifying drainage water L2 discharged from the drainage tank 21 via a path 102 by the action of a pump P1, a fresh water tank 23 for storing fresh water L3 purified by the filtration section 22 and sent via a path 103, an ultraviolet irradiation section 24 for irradiating ultraviolet light onto fresh water L4 sent from the fresh water tank 23 via a path 104 by the action of a pump P2 arranged on the path 104 to destroy organic matter contained in the fresh water L4, an ion exchange resin section 25 for generating pure water L6 from the fresh water L5 generated by the ultraviolet irradiation section 24 and sent via a path 105, and a precision filter section 26 for removing impurities and the like after the organic matter remaining in the pure water L6 purified by the ion exchange resin section 25 and sent via a path 106 is destroyed. Furthermore, in this embodiment, in addition to the above configuration, there are provided a pure water storage tank 27 that stores the pure water L7 filtered by the precision filter unit 26 and discharged through a path 107, and a temperature controller 28 that adjusts the temperature of the pure water stored in the pure water storage tank 27 to an appropriate temperature for use as cutting water to produce pure water L8 and supplies the pure water L8 to the dicing device 1 through a path 108. The pure water storage tank 27 and the temperature controller 28 are configured to be set arbitrarily as required, and the paths 107 and 108 form a pure water supply path that supplies the pure water filtered by the precision filter unit 26 of this embodiment to the dicing device 1.

[0018] In the illustrated embodiment, the filtration unit 22 includes a first filter 221 and a second filter 222, and includes a flow path switching valve V1 so that the operation of the filtration unit 22 can be continued without stopping the operation of the pure water generating apparatus 20. When clogging of one filter is detected, the flow path switching valve V1 is operated to guide the flow of the wastewater L2 guided from the path 102 to the other filter that is not clogged, and the filter in which clogging has been detected is replaced with a new filter. Note that clogging of the filter of the filtration unit 22 can be determined by detecting the pressure in the path 102 with a pressure sensor M1 disposed on the path 102. The ion exchange resin unit 25 includes a first ion exchange resin unit 251 and a second ion exchange resin unit 252, and includes a flow path switching valve V2 so that the operation of the ion exchange resin unit 25 can be continued without stopping the operation of the pure water generating apparatus 20. For example, when consumption of the second ion exchange resin part 252 is detected, the flow path switching valve V2 is operated to guide the fresh water L5 guided from the path 105 to the unconsumed first ion exchange resin part 251, while the second ion exchange resin part 252 is replaced with new ion exchange resin. The degree of consumption of the ion exchange resin can be determined based on the detection value detected by the resistivity sensor M2 that detects the resistivity of the pure water L6 flowing through the path 106.

[0019] The pure water L6 produced by the ion exchange resin section 25 is sent to the precision filter section 26 via a path 106. Impurities are collected in the precision filter section 26, and the pure water L7 is produced from the pure water L6 with the impurities remaining therein removed. Clogging of the precision filter section 26 can be determined by detecting the pressure using a pressure sensor M3 disposed on the path 106.

[0020] 2, a path 109 is connected to the fresh water tank 23, and a drain valve V3 is disposed on the path 109. When cleaning the inside of the fresh water tank 23, the drain valve V3 is opened to allow the fresh water L3 stored in the fresh water tank 23 to flow into the path 109 and be discharged to the outside of the pure water generating apparatus 20 via a drain path 111 connected to the path 109.

[0021] The precision filter section 26 will be described in more detail with reference to FIG. 3(a). FIG. 3(a) shows a vertical cross section of a cylindrical filter case 261 constituting the outer surface of the precision filter section 26, and also shows a precision filter 262 housed in the filter case 261. The precision filter 262 can be made of, for example, polypropylene, polyurethane, etc., and is a filter that has finer meshes than the first filtration filter 221 and the second filtration filter 222 arranged in the filtration section 22 and filters out impurities D that are finer than those in the filtration section 22 with higher precision. It is a rod-shaped filter formed at the axial center of the filter case 261 and extending in the longitudinal direction. A path 106 and a path 107 are connected to the upper end of the precision filter section 26, and the pure water L6 introduced through the path 106 is led to a space S1 between the filter case 261 and the outer periphery of the precision filter 262. Furthermore, the pure water L6 passes through the precision filter 262 from the space S1 side, and is filtered and purified to produce pure water L7, which passes through the center of the precision filter 262 and is discharged from the upper end of the precision filter 262 to a path 107 constituting a pure water supply path. A drain 110 is connected to the bottom of the precision filter section 26, i.e., the bottom 263 of the filter case 261, and the drain 110 is connected to the above-mentioned drain path 111. A pure water supply path valve V4 is disposed on the path 107, and a drain valve V5 is disposed in the drain 110.

[0022] As shown in FIG. 1, the pure water generating apparatus 20 is provided with an operation panel 30 that is integral with a control device (not shown). The control device is configured by a computer, and the pumps P1 to P3, the flow path switching valves V1 and V2, the drain valve V3, the pure water supply channel valve V4, and the drain drain valve V5 are connected to the control device. The operation panel 30 is equipped with a display means that indicates the operating state of the pure water generating apparatus 20, operation buttons, etc. When an operator operates the operation buttons, the operator's instructions are sent to the control device, and the operation of the pumps P1 to P3, the flow path switching valves V1 and V2, the drain valve V3, the pure water supply channel valve V4, the drain drain valve V5, etc. is controlled by an instruction signal from the control device. Note that the pure water supply channel valve V4 and the drain drain valve V5 can also be operated manually, as described later.

[0023] The pure water generating apparatus 20 of this embodiment and the dicing apparatus 1 to which the pure water generating apparatus 20 is applied are generally configured as described above, and the functions and actions of the pure water generating apparatus 20 will be described below.

[0024] The workpiece to be processed in this embodiment is, for example, a substantially disk-shaped wafer 12, which is partitioned by a division line and formed on its surface, as shown in FIG. 1, and is supported by an annular frame F via an adhesive tape T. In the dicing device 1, during normal cutting of the wafer 12, the above-mentioned loading / unloading means 7, transporting means 8, etc. are operated to transport the wafer 12 from the cassette 5 and place it on the holding surface of the chuck table 30. Next, the suction means (not shown) is operated to supply a suction negative pressure to the holding surface of the chuck table 30, so that the wafer 12 is suction-held on the chuck table 30 and fixed by a clamp 32 arranged on the outer periphery of the chuck table 30. Once the wafer 12 is held on the chuck table 30, the X-axis feed means (not shown) is operated to position the chuck table 30 directly under the above-mentioned imaging means 11 to image the wafer 12, and an alignment step is performed to detect the processing positions of the division lines, etc. Next, based on the processing position information of the wafer 12 detected in the alignment process, the chuck table 30 is positioned directly below the cutting means 4, and while spraying cutting water supplied from the pure water generating device 20 from the cutting water supply nozzle 42, the above-mentioned Y-axis feed means and Z-axis feed means are operated together with the X-axis feed means to cut the intended division line of the wafer 12 with the cutting blade 41 of the cutting means 4, thereby dividing the wafer 12 into individual device chips.

[0025] Here, the cutting water ejected from the cutting water supply nozzle 42 becomes wastewater L1 containing cutting chips and the like generated by the cutting process, and flows out into a recovery path (not shown) formed in the dicing device 1. The wastewater L1 flowing out into the recovery path is sent from the dicing device 1 through a path 101 to the pure water generating device 20 and stored in the wastewater tank 21. As described based on FIG. 2, the wastewater L1 stored in the wastewater tank 21 passes through the filtration section 22, the clean water tank 23, the ultraviolet ray irradiation section 24, and the ion exchange resin section 25 to become pure water L6, and the pure water L6 is introduced into the precision filter section 26. Here, as shown in FIG. 3(a), the pure water supply path valve V4 is a valve that is opened when pure water L7 is generated from the wastewater L1 discharged from the dicing device 1 and supplied to the dicing device 1, and at this time, the wastewater drain valve V5 is a valve that is closed. Therefore, during normal operation when wastewater is discharged from the dicing apparatus 1 and pure water is generated in the pure water generator 20, pure water L6 containing impurities D and the like generated by the destruction of organic matter in the ultraviolet irradiation section 24 is filtered with high precision by the precision filter 262 of the precision filter section 26 to become pure water L7 and is discharged from the path 107. The pure water L7 discharged from the precision filter section 26 is temporarily stored in the above-mentioned pure water storage tank 27, and is appropriately temperature-adjusted by the temperature controller 28 before being fed back into the dicing apparatus 1 via the path 108.

[0026] As described above, the pure water L7 is filtered with high precision by the precision filter unit 26, so that impurities D accumulate in the precision filter 262 disposed in the precision filter unit 26. Therefore, in the pure water generating apparatus 20 of this embodiment, a cleaning mode is performed periodically (for example, about once a day) or at any timing to clean the precision filter 262 disposed in the precision filter unit 26. FIG. 3(b) shows the states of the precision filter unit 26, the pure water supply channel valve V4, and the waste water drain valve V5 in the cleaning mode. As shown in FIG. 3(b), the pure water supply channel valve V4 is a valve that is closed when the cleaning mode for cleaning the precision filter unit 26 is performed, and the waste water drain valve V5 is a valve that is opened when the cleaning mode is performed. Then, when the cleaning mode is performed and the precision filter unit 26 is cleaned, the dicing device 1 is not operated, and the above-mentioned pump P2 is operated to introduce pure water L6 containing almost no impurities D that has passed through the fresh water tank 23, ultraviolet irradiation unit 24, and ion exchange resin unit 25 into the precision filter unit 26 via path 106. When this cleaning mode is performed and after the fresh water tank 23 has been cleaned, clean water W (tap water may be used) is introduced via the filtration unit 22 to replenish the amount of water stored in the fresh water tank 23, as shown in FIG.

[0027] 3(b), the pure water L6 introduced into the precision filter section 26 via the path 106 flows through the space S1 within the precision filter section 26, removing impurities D adhering to the surface of the precision filter 262, and is guided to the wastewater drain 110 connected to the bottom, where it is discharged as wastewater L10 containing the impurities D. By carrying out this cleaning mode operation for a predetermined time, the impurities D adhering to the surface of the precision filter 262 are removed, and the degree of clogging of the precision filter 262 is improved.

[0028] According to the embodiment described above, the precision filter section 26 can be cleaned periodically or at any timing, eliminating the need to frequently replace the precision filter section 26 and eliminating the problem of wastefulness.

[0029] In the above embodiment, the pure water supply line valve V4 and the waste water drain valve V5 are described as operating in response to an instruction signal output by a control device (not shown). However, the present invention is not limited to this, and the pure water supply line valve V4 and the waste water drain valve V5 may be opened and closed by operation by an operator.

[0030] In addition, in the above embodiment, an example is shown in which the pure water generating apparatus 20 of this embodiment is applied to a dicing apparatus 1, but the present invention is not limited to this, and can also be applied to other processing apparatuses that use pure water as processing water, such as grinding apparatuses, polishing apparatuses, etc. [Explanation of symbols]

[0031] 1: Dicing equipment 2: Device housing 3: Chuck table mechanism 30: Chuck table 32: Clamp 4:Cutting means 41: Cutting blade 42: Cutting water supply nozzle 5: Cassette 6: Temporary table 7: Carrying in / out means 8: Means of transportation 9: Cleaning method 10: Cleaning and transport means 11: Imaging means 20:Pure water generator 20A: Housing 21:Drainage tank 22:Filtration section 221: First filtration filter 222: Second filtration filter 23: Fresh water tank 24: UV irradiation unit 25: Ion exchange resin section 26: Precision filter section 262: Precision filter 27: Pure water storage tank 28: Temperature controller 30: Operation panel 101~109: Route 110: Drain 111:Drainage route V1, V2: Flow path switching valve V3: Drain valve V4: Pure water supply valve V5: Drain valve P1~P3: Pump

Claims

[Claim 1] A pure water generating apparatus that generates pure water from wastewater discharged from a processing device and supplies the pure water to the processing device, the system includes at least a drainage tank for storing wastewater, a filtration unit for filtering the wastewater discharged from the drainage tank, a fresh water tank for storing fresh water generated by the filtration unit, an ultraviolet irradiation unit for irradiating the fresh water discharged from the fresh water tank with ultraviolet light to destroy organic matter, an ion exchange resin unit for purifying the fresh water discharged from the ultraviolet irradiation unit into pure water, a precision filter unit for filtering the pure water purified by the ion exchange resin unit with high precision, and a pure water supply path connected to the precision filter unit for supplying the pure water filtered by the precision filter unit to a processing device, a pure water supply line valve for opening and closing the pure water supply line is disposed in the pure water supply line, a drain is connected to a bottom of the precision filter unit, and a drain valve for opening and closing the drain is disposed in the drain; the pure water supply channel valve is a valve that is opened when pure water is generated from wastewater discharged from a processing device and supplied to the processing device, and that is closed when the precision filter unit is cleaned; the wastewater drain valve is a valve that is closed when pure water is generated from wastewater discharged from a processing device and supplied to the processing device, and that is opened when the precision filter unit is cleaned; In the case of cleaning the precision filter section, the pure water generating apparatus opens the wastewater drain valve while introducing pure water which has passed through the clean water tank, the ultraviolet ray irradiation section and the ion exchange resin section into the precision filter section.

Images