JP2022156547A - Pure water generator - Google Patents

Abstract

To provide a pure water generator that can solve the problem of toxic gases without requiring extensive additional equipment.SOLUTION: A pure water generator includes at least: a drainage tank 21 for storing wastewater L0; a filtration part 22 for filtering the wastewater L1 pumped out from the drainage tank 21; a fresh water tank 23 for storing fresh water L4 generated by the filtration part 22; an ultraviolet irradiation part 24 for decomposing organic matter by irradiating the fresh water L4 pumped out of the fresh water tank 23 with ultraviolet rays; an ion exchange resin part 25 for purifying fresh water L5 pumped out of the ultraviolet irradiation part 24 into pure water; and a pure water supply part 27 for supplying pure water L6 purified by the ion exchange resin part 25 to a processing device. Detoxification means 50 is installed in the drainage tank 21 to inhale a toxic gas G1 generated from the drainage L0 and supply it to a scrubber 52 to detoxify and exhaust the toxic gas G1 by dissolving toxic components in water.SELECTED DRAWING: Figure 2

Description

The present invention relates to a pure water generator that produces pure water from waste water.

A wafer having a plurality of devices such as ICs, LSIs, etc. formed on a surface partitioned by division lines is ground by a grinding machine to form a back surface to a desired thickness, and then divided into individual device chips by a dicing machine. , cell phones, and personal computers.

Grinding equipment and dicing equipment use pure water as processing water. Therefore, the present applicant has developed and proposed a device for purifying waste water discharged from the processing equipment into pure water and circulating it (patent See reference 1).

JP 2009-214193 A

The pure water generating apparatus described in Patent Document 1 above includes a drain tank for storing waste water, a filtering unit for filtering the waste water sent out from the drain tank, and a clean water for storing fresh water generated by the filtering unit. a tank, an ultraviolet irradiation section for irradiating the fresh water sent from the fresh water tank with ultraviolet rays to destroy organic matter, an ion exchange resin section for purifying the fresh water sent from the ultraviolet irradiation section into pure water, and the ion exchange. It includes a precision filter section for filtering the pure water purified by the resin section, and a pure water supply section for supplying the pure water sent from the precision filter section to the processing equipment.

When the workpiece to be processed in the above processing equipment (grinding equipment, dicing equipment, etc.) is a wafer made of GaAs (gallium arsenide), the wastewater discharged from the processing equipment and stored in the drainage tank may cause damage to the human body. Potentially harmful toxic arsine gas is produced. However, since the conventional pure water generator cannot treat the toxic gas, an exhaust port is provided in the upper part of the drain tank to suck the gas and send it to a purifying device provided as a separate device. After detoxifying it, it is discharged out of the clean room in which the processing equipment is installed. However, when such a purifier is installed, the equipment becomes large-scaled and uneconomical, which is a problem.

The present invention has been made in view of the above facts, and its main technical problem is to provide a pure water generator that can solve the problem of toxic gases without the need for adding large-scale equipment. .

In order to solve the main technical problems described above, according to the present invention, there is provided a pure water generating apparatus for generating pure water from waste water, comprising a waste water tank for storing waste water, and a filter for filtering the waste water sent out from the waste water tank. a fresh water tank for storing fresh water generated by the filtration unit; an ultraviolet irradiation unit for irradiating the fresh water sent from the fresh water tank with ultraviolet rays to destroy organic matter; and fresh water sent from the ultraviolet irradiation unit. and a pure water supply unit for supplying the pure water purified by the ion exchange resin unit to a processing device, and the waste water tank stores the water generated from the waste water. Provided is a pure water generator provided with a detoxifying means for drawing in poisonous gas, supplying it to a scrubber, and dissolving the poisonous component in water to detoxify and exhaust the poisonous gas.

Preferably, the water supplied to the scrubber is any one of waste water stored in a waste water tank, fresh water filtered by the filtering section, and pure water purified by the ion exchange resin section. More preferably, the water containing the toxic component is purified into pure water in the ion exchange resin section.

The pure water generator of the present invention is a pure water generator for generating pure water from waste water, and comprises a waste water tank for storing waste water, a filtration unit for filtering the waste water sent out from the waste water tank, and the filtration unit. a fresh water tank for storing fresh water produced by the above; an ultraviolet irradiation unit for irradiating the fresh water sent from the fresh water tank with ultraviolet rays to destroy organic matter; and a clean water sent from the ultraviolet irradiation unit for purifying pure water. At least an ion exchange resin part and a pure water supply part for supplying pure water purified by the ion exchange resin part to a processing device, and the waste water tank is provided with a scrubber for sucking toxic gas generated from the waste water. and dissolving the toxic component in water to detoxify and exhaust the toxic gas. The water generator can detoxify the toxic gas and solve the problem of being uneconomical.

1 is an overall perspective view of a pure water generator and a dicing device according to this embodiment; FIG. 2 is an exploded perspective view showing a schematic configuration housed inside the pure water generating apparatus shown in FIG. 1. FIG. FIG. 3 is a conceptual diagram showing an outline of detoxifying means arranged in the pure water generator shown in FIG. 2;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pure water generator constructed based on the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an example in which a pure water generator 20 of this embodiment is applied to a known dicing machine 1. As shown in FIG.

A dicing apparatus 1 of this embodiment includes a substantially rectangular parallelepiped apparatus housing 2, a chuck table mechanism 3 that holds a wafer 12 as a workpiece, and a cutting blade that cuts the wafer 12 held by the chuck table mechanism 3. and a cutting means 4 provided with 41 . The dicing apparatus 1 includes a cassette 5 (indicated by a chain double-dashed line) accommodating a plurality of wafers 12, a temporary placement table 6 for unloading and temporarily placing the wafers 12 accommodated in the cassette 5, and a wafer on the temporary placement table 6. a loading/unloading means 7 for loading/unloading the wafer 12 carried out onto the temporary placement table 6; Means 9 (details are omitted), cleaning transport means 10 for transporting the cut wafer 12 from the chuck table mechanism 3 to the cleaning means 9, and imaging means 11 for imaging the wafer 12 on the chuck table mechanism 3. and control means (not shown). The cassette 5 is placed on a cassette table 5a which is vertically movable by a lifting means (not shown). is adjusted accordingly. The wafer 12 processed in this embodiment is a wafer made of a gallium arsenide (GaAs) substrate.

In the apparatus housing 2, there is means for relatively moving the chuck table mechanism 3 and the cutting means 4 for processing and feeding. X-direction feeding means for moving the cutting means 4 in the X direction indicated by X, Y-direction feeding means for moving the cutting means 4 in the Y direction indicated by the arrow Y perpendicular to the X direction, and cutting means 4 perpendicular to the X and Y directions. Z-direction feeding means (both not shown) for moving in the Z-direction indicated by arrow Z is provided. Further, the cutting means 4 is provided with a cutting water supply nozzle 42 for supplying pure processing water (cutting water) to the cutting position when cutting the wafer sucked and held on the chuck table 30 . there is

The cutting water supplied from the cutting supply nozzle 42 is supplied to the cutting position when cutting is performed, and then is recovered by a recovery path (not shown) provided in the dicing device 1, and is recovered by the device housing 2. , is sent as waste water L0 to the pure water generator 20 of the present embodiment, which is arranged adjacently via the path 100. As shown in FIG. The waste water L0 sent to the pure water generator 20 is purified by the pure water generator 20 to become pure water L8, which is again supplied to the dicing machine 1 as cutting water via the path 108 .

The pure water generator 20 will be described more specifically with reference to FIG. 2 in addition to FIG. FIG. 2 shows a perspective view of a schematic configuration housed inside the housing 20A of the pure water generator 20. As shown in FIG.

As shown in FIG. 2, the pure water generator 20 includes a drain tank 21 for storing waste water L0 discharged from the dicing machine 1 through a path 100, and a pump P1 from the drain tank 21 to drain the waste water through a path 102. A filtering unit 22 for filtering the waste water L1 discharged by the filter unit 22, a fresh water tank 23 for storing fresh water L3 filtered by the filtering unit 22 and sent via the path 103, and a pump P2 arranged on the path 104. UV irradiation unit 24 that irradiates the fresh water L4 discharged from the fresh water tank 23 with ultraviolet rays to destroy the organic matter contained in the fresh water L4, and the fresh water L5 after the organic matter is destroyed by the ultraviolet irradiation unit 24. is introduced via a path 105 to refine the pure water L5 into pure water L6, and the pure water L6 introduced via a path 106 connected to the ion exchange resin section 25 is filtered with high accuracy. and a pure water supply unit 27 for supplying pure water L7 filtered by the precision filter unit 26 and introduced through a path 107 to the dicing apparatus 1. The wastewater tank 21 of the water generator 20 is provided with a detoxifying means 50 for sucking the toxic gas G1 generated from the wastewater L0 contained in the wastewater tank 21, detoxifying the toxic gas G1, and discharging it as a harmless exhaust gas G2. are arranged.

In the illustrated embodiment, the filtration unit 22 includes a first filtration filter 221 and a second filtration filter 222. A channel switching valve V1 is provided. When clogging is detected while one filter is in use, the channel switching valve V1 is actuated to direct the flow of the waste water L1 guided from the path 102 to the other non-clogged filter, Replace the clogged filter with a new filter. It should be noted that clogging of the filtration filter of the filtration unit 22 can be determined by detecting the pressure in the path 102 with the pressure sensor M1 arranged on the path 102 .

The ion-exchange resin part 25 includes a first ion-exchange resin part 251 and a second ion-exchange resin part 252, and is configured so that the operation of the ion-exchange resin part 25 can be continued without stopping the operation of the pure water generator 20. is provided with a flow path switching valve V2. For example, when exhaustion of the second ion-exchange resin part 252 is detected, by operating the channel switching valve V2, fresh water L5 guided from the path 105 is during which 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 specific resistance value sensor M2 that detects the specific resistance value of the pure water L6 flowing through the path 106. FIG.

The pure water L6 produced by the ion exchange resin section 25 is sent to the precision filter section 26 via the path 106. As shown in FIG. The pure water L7 is produced by removing the impurities remaining in the pure water L6 in the precision filter section 26 . It should be noted that clogging of the precision filter section 26 can be determined by detecting pressure with the pressure sensor M3 arranged on the path 106 .

The pure water supply unit 27 includes a pump (not shown), stores the pure water L7 discharged from the precision filter unit 26, adjusts the temperature of the pure water L7 appropriately, and supplies temperature-controlled pure water. L8 is supplied to the dicing machine 1 via path 108. FIG.

The detoxification means 50 of this embodiment will be described more specifically with reference to FIGS. 2 and 3. FIG. The detoxification means 50 is arranged in the drainage tank 21 . The detoxifying means 50 has a fan 51 and a scrubber 52 . As shown in FIG. 3, waste water L0 is stored in the waste water tank 21, and the upper space in the waste water tank 21 is filled with toxic gas G1 generated from the waste water L0. The fan 51 is arranged in a path 101 connected to the upper space in the drain tank 21 so as to suck the poisonous gas G1 that fills the drain tank 21 . By operating the fan 51 , the toxic gas G 1 filling the drain tank 21 is sucked and sent to the scrubber 52 . The scrubber 52 of this embodiment is, as shown in the figure, a so-called wet scrubber system, and the toxic gas G1 sent from the fan 51 is introduced into the lower space 54 of the scrubber case 53 .

A filler 55 is mounted above the lower space 54 of the scrubber case 53 . The filling material 55 has air permeability, and the toxic gas G1 supplied from below and water supplied from above are brought into contact with each other to dissolve the toxic components of the toxic gas G1 in the water supplied to the filling material 55. It has a function of discharging water below the filler 55 . Further, the filler 55 is selected from materials that are not chemically changed by the toxic components contained in the toxic gas G1, such as porous ceramics, fiber aggregates, and the like. A nozzle portion 102b connected to a branch path 102a branched from the path 102 is provided in the upper space 56 above the filler 55 . Injection ports 102c are formed at regular intervals on the lower surface of the nozzle portion 102b, and the waste water L1 guided from the path 102 is sprayed downward from the injection ports 102c in the form of mist. The waste water L1 injected from the injection port 102c is supplied to the upper surface of the filler 55, permeates the entire inside of the filler 55, and is held therein. A drip-proof member 57 is arranged above the nozzle portion 102b. The drip-proof member 57 covers the top of the filler 55 and can be made of the same member as the filler 55 described above. The drip-proof member 57 functions to capture the liquid component contained in the exhaust gas G2 that escapes from the upper space 56 to the exhaust space 58 above the drip-proof member 57 and drop it onto the filler 55 side. The exhaust gas G2 passes through the exhaust space 58 and is discharged to the outside from the discharge portion 59 . On the lower surface of the scrubber case 53, a drainage channel 53a is provided that connects the lower space 54 and the area in the drainage tank 21 in which the drainage L0 is stored. The discharged waste water L2 is discharged to the waste water tank 21 side. Toxic components discharged into the drainage tank 21 together with the drainage L2 are removed in the ion exchange resin section 25 as described later. Further, when the dicing apparatus 1 and the pure water generator 20 are installed in a clean room, a duct for discharging the exhaust gas G2 to the outside of the clean room may be connected to the discharge section 59.

As shown in FIG. 1, the pure water generator 20 is provided with an operation panel 30 that is integrated with a control device (not shown). The control device is composed of a computer and is electrically connected to the pumps P1 and P2, the flow path switching valves V1 and V2, the fan 51 and the like. The operation panel 30 includes display means for indicating the operating state of the pure water generator 20, operation buttons, and the like. When the operator operates the operation button, the operator's instruction is generated by the control device, and the operation of the pumps P1, P2, the flow path switching valves V1, V2, the fan 51, etc. is performed by the instruction signal from the control device. controlled.

The dicing apparatus 1 and the pure water generator 20 of the present embodiment are generally configured as described above, and the functions and actions of the pure water generator 20 will be described below.

The workpiece to be processed in this embodiment is the wafer 12 made of a gallium arsenide (GaAs) substrate as described above, and as shown in FIG. , and is supported by an annular frame F with an adhesive tape T interposed therebetween. In the dicing apparatus 1, when cutting the wafer 12, the carrying-in/out means 7, the carrying means 8, etc. are operated to carry the wafer 12 from the cassette 5 and onto the holding surface of the chuck table 30. Place. Next, by operating a suction means (not shown), a suction negative pressure is supplied to the holding surface of the chuck table 30 to hold the wafer 12 by suction on the chuck table 30 and arrange it on the outer circumference of the chuck table 30 . clamp 32. After the wafer 12 is held on the chuck table 30, the X-direction feeding means (not shown) is operated to position the chuck table 30 directly below the imaging means 11, and the wafer 12 is imaged. An alignment step is performed to detect the processing position of the . Next, based on the processing position information of the wafer 12 detected by the alignment process, the chuck table 30 is positioned directly below the cutting means 4, and while cutting water is jetted from the cutting water supply nozzle 42, the X-direction feeding means and the above Then, the Y-direction feeding means and Z-direction feeding means are operated to cut the dividing lines of the wafer 12 with the cutting blade 41 of the cutting means 4 to divide the wafer 12 into individual device chips.

Here, the cutting water jetted from the cutting water supply nozzle 42 becomes the waste water L0 containing chips and the like generated by the cutting process, and flows out to a collection path (not shown) formed in the dicing apparatus 1 . The waste water L0 flowing out to the recovery path is sent from the dicing device 1 to the pure water generator 20 via the path 100 and stored in the waste water tank 21 . As described with reference to FIG. 2, the waste water L0 stored in the waste water tank 21 is sent to the filtration unit 22 through the path 102 by the action of the pump P1, filtered, and then discharged into the clean water tank 23 and the ultraviolet irradiation unit 24. , the ion-exchange resin portion 25 to become pure water L6, and the pure water L6 is introduced into the precision filter portion 26. As shown in FIG. The pure water L6 is filtered with high accuracy by the precision filter unit 26 to be pure water L7, which is stored in the pure water supply unit 27 described above, and becomes pure water L8 that has undergone appropriate temperature adjustment. 108, it is put into the dicing machine 1 again.

As described with reference to FIGS. 2 and 3, the drain tank 21 of the pure water generator 20 of the present embodiment is provided with the detoxification means 50, and the action of the fan 51 causes water to be stored in the drain tank 21. The toxic gas G1 generated from the discharged waste water L0 is sucked and supplied to the scrubber 52 . As shown in FIG. 3, the toxic gas G1 supplied to the scrubber 52 is introduced into the lower space 54 of the scrubber case 53. As shown in FIG. The toxic gas G1 introduced into the lower space 54 rises through the filling material 55 from the lower space 54 side. On the other hand, on the upper surface of the filler 55, as described above, the waste water L1 is injected from the injection port 102c of the nozzle portion 102b branched from the path 102, and held in the filler 55. The remaining waste water L1 drips into the lower space 54 side. In the filling material 55, the toxic gas G1, which is a gas, and the waste water L1 come into contact with each other, whereby the toxic components (arsine gas, etc.) contained in the toxic gas G1 are dissolved in the waste water L1, and the waste water L2 containing the toxic components such as arsine gas, It is discharged through the drainage channel 53 a and collected in the drainage tank 21 .

The exhaust gas G2 discharged to the upper space 56 passes through the drip-proof member 57 having air permeability and is discharged to the exhaust space 58 . When the exhaust gas G2 passes through the upper space 56 and rises, the water component contained in the exhaust gas G2 is removed and drips onto the filler 55 side. The detoxified exhaust G<b>2 discharged to the exhaust space 58 is discharged from the discharge portion 59 .

As described above, by introducing the waste water L2 discharged from the scrubber 52 into the waste water L0 stored in the waste water tank 21, the waste water L0 becomes waste water containing toxic components such as arsine gas. The waste water L0 stored in the waste water tank 21 is sucked and pumped from the strainer 21a connected to the pump P1, sent to the filtration unit 22 through the path 102, filtered, and then passed through the clean water tank 23. Then, it is sent to the ultraviolet irradiation section 24 and the ion exchange resin section 25 . In the ultraviolet irradiating section 24, the fresh water L4 introduced into the ultraviolet irradiating section 24 is irradiated with ultraviolet rays, thereby destroying the toxic component (arsine gas) and discharging the fresh water L5. Further, the fresh water L5 is introduced into the ion-exchange resin part 25, and the fresh water L5 is ion-exchanged, thereby removing the toxic components contained in the fresh water L5 and refining the fresh water L5 into the pure water L6. . Next, the pure water L 6 is introduced into the precision filter section 26 and the pure water L 7 that has been precisely filtered is sent to the pure water supply section 27 . The pure water supply unit 27 performs temperature control and the like on the introduced pure water L7, and supplies the pure water L8 to the processing apparatus, that is, the dicing apparatus 1 through the path .

According to the above-described embodiment, there is no need to prepare a large-scale facility for detoxifying toxic gases, and toxic gases can be detoxified by the pure water generator, which solves the problem of being uneconomical. . In particular, in the present embodiment, the water that dissolves the toxic components in the scrubber 52 is part of the water (waste water L0 in this embodiment) that is circulated in the pure water generator 20, and the toxic components are dissolved. The water is irradiated with ultraviolet rays and ion-exchanged by the ion-exchange resin part to obtain pure water. Since it is destroyed and processed within 20, it is possible to efficiently utilize the existing pure water generator 20. FIG.

In the above-described embodiment, an example is shown in which the water supplied to the scrubber 52 of the detoxification means 50 is the waste water L0 discharged from the processing device 1 and stored in the waste water tank 21, but the present invention is limited to this. First, for example, as shown by the dashed line in FIG. 2, the fresh water L4 filtered by the filtering unit 22 is introduced into the pump P3 on the path 109 connected to the fresh water tank 23 so as to be supplied to the scrubber 52 of the detoxification means 50. The path 102d is connected, the introduction path 102d is connected to the scrubber 52, and the clean water L4 is supplied from the injection port 102c, which is connected to the nozzle portion 102b described with reference to FIG. You may make it inject. Alternatively, as indicated by a dashed line in FIG. 2, a path connected to path 106 is provided to supply pure water L6 ion-exchanged in ion exchange resin part 25 to scrubber 52 of detoxifying means 50. An introduction path 102e is connected to the pump P4 on 110, the introduction path 102e is connected to the scrubber 52, and is connected to the nozzle portion 102b described with reference to FIG. The fresh water L6 may be jetted from the jet port 102c. The present invention does not exclude city water as water to be supplied to the scrubber 52 of the detoxification means 50 .

In the embodiment described above, an example in which the pure water generator 1 is applied to the dicing device 1 is shown, but the present invention is not limited to this, and may be applied to, for example, a polishing device or a grinding device. In addition, in the above-described embodiment, an example is shown in which pure water is generated from waste water discharged after being used for processing a GaAs substrate, and arsine gas is generated from the waste water, but the present invention is limited to this. It can be applied to any pure water generator that needs to detoxify toxic gases containing toxic components that are not contaminated and can be dissolved in water.

1: Dicing device 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 placement table 7: Loading/unloading means 8: Transfer Means 9: Washing means 10: Washing and conveying means 12: Wafer 20: Pure water generator 20A: Housing 21: Drainage tank 22: Filtration section 23: Clear water tank 24: Ultraviolet irradiation section 25: Ion exchange resin section 26: Precision filter section 27: Pure water supply unit 50: Detoxifying means 51: Fan 52: Scrubber 53: Scrubber case 53a: Drainage channel 54: Lower space 55: Filling material 56: Upper space 57: Drip-proof member 58: Exhaust space 59: Discharge unit 100 to 110: Path 102a: Branch path 102b: Nozzle part 102c: Injection ports 102d, 102e: Introduction path G1: Poisonous gas G2: Exhaust gas

Claims (3)

A pure water generator for producing pure water from waste water,
A wastewater tank for storing wastewater, a filtering unit for filtering the wastewater sent out from the wastewater tank, a fresh water tank for storing fresh water generated by the filtering unit, and irradiating the fresh water sent from the fresh water tank with ultraviolet rays. an ultraviolet irradiating section that destroys organic matter by means of an ultraviolet ray irradiating section; an ion exchange resin section that purifies the clear water sent out from the ultraviolet ray irradiating section into pure water; at least a water supply;
A pure water generating apparatus in which a detoxifying means for sucking toxic gas generated from wastewater, supplying the toxic gas to the scrubber, dissolving the toxic component in water to detoxify the toxic gas, and exhausting the toxic gas is disposed in the drain tank. 2. Pure water generation according to claim 1, wherein the water supplied to the scrubber is any one of waste water stored in a waste water tank, fresh water filtered by the filtration unit, and pure water purified by the ion exchange resin unit. Device. 2. The pure water generator according to claim 1, wherein the water containing the toxic component is purified into pure water in the ion exchange resin section.

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