JP2011011261A - Cooling system for machining apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system for a machining apparatus, capable of economically cooling a spindle assembly of a machining apparatus.SOLUTION: The cooling system includes: reverse osmotic membrane modules 4A, 4B for separating the water supplied from a water supply source 6 into condensed drainage and pure water; a pressurizing pump 14 for pressurizing the water supplied to the reverse osmotic membrane modules 4A, 4B from the water supply source 6, a drainage path 26 for draining condensed drainage from the reverse osmotic membrane modules 4A, 4B; a drainage return path 36 connected to the upstream side from the pressurizing pump 14; a pure water outflow path 18 for flowing out pure water generated by the reverse osmotic membrane modules 4A, 4B; a switching valve 30 disposed at a branch point of the drainage path 26 and the drainage return path 36; a cooling water guide path 58 that is branched from the upstream side of the switching valve 30 or branched from the drainage return path 36 to guide cooling water for cooling the spindle assembly 46; and a cooling water drainage path 60 for returning the cooling water discharged from the spindle assembly 46 to the drainage path 26.

Description

  The present invention relates to a cooling system for a processing apparatus connected to a pure water generator that can easily generate pure water.

  For example, in a semiconductor device manufacturing process, a semiconductor wafer having a plurality of semiconductor devices such as ICs and LSIs formed on the surface thereof is ground to a desired thickness by grinding the back side thereof with a grinding device. Thereafter, the thinned semiconductor wafer is divided into individual semiconductor devices by a cutting apparatus, whereby a plurality of semiconductor devices are manufactured.

  The grinding apparatus includes a holding table that holds a workpiece such as a semiconductor device, a grinding wheel that grinds the workpiece held on the holding table, and a spindle assembly that includes a spindle that rotates the grinding wheel. The workpiece is ground by contacting the workpiece held by the holding table while the grinding wheel rotates at about 6000 rpm.

  On the other hand, the cutting device includes a holding table for holding a workpiece such as a semiconductor wafer, a cutting blade for cutting the workpiece held on the holding table, and a spindle assembly including a spindle for rotating the cutting blade. . The workpiece is cut by cutting into the workpiece held on the holding table while the cutting blade rotates at a high speed of about 30000 rpm.

  In these grinding apparatuses and cutting apparatuses, grinding or cutting is performed while supplying machining water for the purpose of removing machining wastes associated with machining or cooling the heat generated by machining.

  Even if a trace amount of impurities remains on the semiconductor device, the quality of the semiconductor device is seriously affected. Therefore, pure water is used as cleaning water or processing water in the manufacturing process of semiconductor devices, and pure water is also used as processing water in these grinding apparatuses and cutting apparatuses.

  Pure water refers to water having a specific resistance value of about 1 to 10 MΩ · cm. Pure water is produced by passing city water through a filter, activated carbon filter, ion exchange resin or reverse osmosis membrane. A pure water production apparatus as disclosed in Japanese Patent No. 189760 is used.

JP 2000-189760 A

  On the other hand, the spindle that rotates the grinding wheel of the grinding device and the spindle that rotates the cutting blade of the cutting device are rotated at a high speed. A cooling water passage for circulating the cooling water is formed, and pure water is generally used as the cooling water for the spindle assembly.

  However, pure water is very expensive, and it is not economical to use pure water as cooling water for the spindle assembly.

  The present invention has been made in view of these points, and an object of the present invention is to provide a cooling system for a machining apparatus capable of economically cooling the spindle assembly of the machining apparatus.

  According to the present invention, there is provided a cooling system for a processing apparatus including a spindle assembly, a water supply source, a reverse osmosis membrane module that separates water supplied from the water supply source into concentrated waste water and pure water, A water supply path for supplying water from the water supply source to the reverse osmosis membrane module, a pressure pump provided on the water supply path for pressurizing water supplied to the reverse osmosis membrane module, and the reverse osmosis membrane A drainage path for draining the concentrated drainage from the module, a drainage return path branched from the drainage path and connected to the upstream side of the pressure pump of the water supply path, and a pure osmotic membrane generated by the reverse osmosis membrane module A pure water outflow path through which water flows out, an open / close valve disposed on the drainage path downstream from the branch point of the drainage path and the drainage return path, and an upstream side of the open / close valve in the drainage path Branch or the drain return path A cooling water introduction path that is branched and connected to the spindle assembly, introduces cooling water for cooling the spindle assembly, and is connected to the spindle assembly and the drainage path upstream of the opening / closing valve. There is provided a cooling system for a processing apparatus, comprising a cooling water discharge path for returning cooling water discharged from the assembly to the drainage path.

  Preferably, the cooling system of the processing apparatus further includes pure water concentration measuring means for measuring the concentration of pure water disposed on any one of the drainage path, the drainage return path, and the pure water outflow path, Opening and closing of the open / close valve is controlled based on the pure water concentration measured by the pure water concentration measuring means.

  According to the present invention, since the waste water from the pure water generating apparatus can be used as the cooling water for the spindle assembly in the processing apparatus, it is not necessary to use new pure water as the cooling water for the spindle assembly, which is economical.

It is a schematic diagram of the cooling system of the processing apparatus which concerns on 1st Embodiment of this invention. It is a schematic diagram of the cooling system of the processing apparatus which concerns on 2nd Embodiment of this invention.

  Hereinafter, a cooling system for a machining apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a cooling system 42 for a processing apparatus according to a first embodiment of the present invention is schematically shown. The cooling system 42 of the processing apparatus is connected to the pure water generator 2.

  The pure water generating apparatus 2 includes two reverse osmosis membrane modules 4A and 4B arranged in parallel. Here, the reverse osmosis membrane is a kind of filtration membrane and refers to a membrane having a property of not allowing impurities other than water such as ions and salts to pass through water. The reverse osmosis membrane has a large number of pores having a size of approximately 2 nm or less.

  The structure of the reverse osmosis membrane needs to be able to withstand high pressure, and currently, a structure such as a hollow fiber membrane, a spiral membrane, or a tubular membrane is adopted. Moreover, as a material of the reverse osmosis membrane, cellulose acetate, aromatic polyamide, polyvinyl alcohol, polysulfone or the like is employed.

  For example, city water (tap water) is supplied from the water supply source 6 to the water supply path 8. The water supply path 8 is provided with an activated carbon filter 10 and a filter 12. The activated carbon filter 10 removes chlorine and the filter 12 removes dust and the like.

  The water supply path 8 is further provided with a pressurization pump 14 and a thermometer 16, and the reverse osmosis membrane is formed by pressurizing the water supplied from the water supply source 6 to a high pressure (for example, 60 atm) by the pressurization pump 14. Supply to modules 4A and 4B. The thermometer 16 measures the temperature of the supplied water.

  The pure water generated by the reverse osmosis membrane modules 4A and 4B is discharged to the pure water outflow path 18. In the pure water outflow path 18, a flow rate adjusting device 20, pure water concentration measuring means 22 for measuring the electrolyte concentration of pure water, and a filter 24 are disposed. The pure water concentration measuring means 22 measures the electrical resistivity or electrical conductivity of pure water.

  In the present embodiment, the pure water produced by the reverse osmosis membrane modules 4A and 4B has a specific resistance value of about 1 MΩ · cm. The filter 24 preferably has a fine mesh of about 0.2 μm, for example.

  Concentrated wastewater is discharged from the reverse osmosis membrane modules 4A and 4B to the drainage passage 26. A flow rate adjusting device 28 and an opening / closing valve 30 are provided in the drainage path 26.

  A pure water return path 32 is branched from the pure water outflow path 18, and this pure water return path 32 is connected upstream of the pressurizing pump 14 in the water supply path 8. Further, a drain return path 36 is provided that branches from the drain path 26, and the drain return path 36 is connected to the upstream side of the pressure supply pump 14 of the water supply path 8.

  The pure water return path 32 is provided with a check valve 34 that permits the passage of pure water from the pure water outflow path 18 and prevents the passage of water from the water supply path 8. Similarly, the drain return path 36 is provided with a check valve 38 that allows passage of drainage from the drainage path 26 and prevents passage of water from the water supply path 8.

  The drainage return path 36 is further provided with pure water concentration measuring means (concentrated wastewater concentration measuring means) 40 for measuring the electrolyte concentration of the concentrated wastewater. Similarly to the pure water concentration measuring means 22 provided in the pure water outflow path 18, the pure water concentration measuring means 40 also measures the electrical resistivity or electrical conductivity in the concentrated waste water and detects the electrolyte concentration in the concentrated waste water. To do.

  The on-off valve 30 is connected to the pure water concentration measuring means 22, 40, and based on the pure water concentration measured by the pure water concentration measuring means 22 or the concentrated drainage measured by the pure water concentration measuring means 40. Based on the concentration, the degree of opening / closing of the opening / closing valve 30 is controlled. Thereby, the waste_water | drain from the pure water production | generation apparatus 2 can be controlled to required minimum.

  Moreover, the rise of the supplied water temperature is assumed depending on the kind of pressurizing pump 14. In this case, the water temperature is measured by the thermometer 16 provided on the downstream side of the pressurizing pump 14, and the open / close valve 30 is controlled according to the measured temperature.

  The flow rate adjusting devices 20 and 28 are composed of a flow meter and a flow rate adjusting valve. By adjusting these flow rate adjusting devices 20 and 28, the flow rate balance between the pure water and the concentrated drainage from the reverse osmosis membrane modules 4A and 4B is adjusted. Control.

  In the cooling system 42 for the processing apparatus according to the present embodiment, the concentrated waste water from the pure water generating apparatus 2 is used as cooling water for the processing apparatus. Reference numeral 44 schematically shows a cutting apparatus which is a kind of processing apparatus.

  The spindle assembly 46 of the cutting device 44 has a spindle 50 housed in a spindle housing 48, and a cutting blade 52 is attached to the tip of the spindle 50. 54 is a holding table of the cutting device 44, and 56 is a bellows.

  In the cooling system 42 of the present embodiment, a cooling water introduction path 58 for cooling the spindle assembly 46 and a cooling water discharge path 60 circulated through the spindle assembly 46 are upstream of the opening / closing valve 30 of the drainage path 26. Connected to the side.

  The cooling water introduction passage 58 is provided with a check valve 62 that allows passage of the cooling water from the drainage passage 26 and prevents passage in the reverse direction. The cooling water discharge passage 60 is provided with cooling from the spindle assembly 46. A check valve 64 that allows water to pass and prevents reverse passage is provided.

  In the embodiment shown in FIG. 1, the cooling water introduction path 58 and the cooling water discharge path 60 are connected to the drainage path 26 on the upstream side of the on-off valve 30, but the cooling water introduction path 58 and the cooling water discharge path 60. May be connected to the drain return path 36.

  Hereinafter, the operation of the cooling system 42 of the processing apparatus according to the present embodiment that uses the concentrated drainage of the pure water generation apparatus 2 configured as described above as cooling water for the spindle assembly 46 will be described together with the operation of the pure water generation apparatus 2. .

  The city water supplied from the water supply source 6 has chlorine removed by the activated carbon filter 10, dust is removed by the filter 12, and then pressurized to a high pressure by the pressure pump 14 and supplied to the reverse osmosis membrane modules 4A and 4B. Is done.

  In the reverse osmosis membrane modules 4A and 4B, only water molecules permeate from the high concentration side partitioned by the reverse osmosis membrane to the low side, and pure water is generated. The generated pure water is discharged to the pure water outflow path 18 and is used as processing water for these processing devices when processing devices such as a cutting device and a grinding device are operating.

  Pure water that is not used as processing water for the processing apparatus is returned to the water supply path 8 upstream of the pressurizing pump 14 through the pure water return path 32. Since the pure water return path 32 is thus provided, it is not necessary to provide a tank for storing the pure water generated by the pure water generator 2, and the pure water generator 2 can be operated continuously.

  On the other hand, the degree of opening and closing of the concentrated wastewater discharged from the reverse osmosis membrane modules 4A and 4B to the drainage path 26 is controlled according to the concentration of pure water and / or the water temperature supplied to the reverse osmosis membrane modules 4A and 4B. Drained through the opening / closing valve 30.

  A part of the concentrated drainage is returned to the water supply path 8 upstream of the pressurizing pump 14 via the drainage return path 36 and the other part is used as cooling water for the spindle assembly 46 of the cutting device 44. .

  That is, a part of the concentrated drainage discharged to the drainage path 26 is introduced into the spindle assembly 46 via the check valve 62 and the cooling water introduction path 58 to cool the heat generation of the spindle assembly 46 accompanying the high-speed rotation of the spindle 50. To do. The cooling water circulated through the spindle assembly 46 is returned to the drainage path 26 via the cooling water discharge path 60 and the check valve 64.

  On the other hand, the pure water returned through the pure water return path 32 and the concentrated waste water returned through the drain return path 36 are again pressurized by the pressure pump 14 and supplied to the reverse osmosis membrane modules 4A and 4B. The By circulating pure water and concentrated waste water in this way, it is possible to save water such as city water supplied from the water supply source 6.

  In the embodiment shown in FIG. 1, an example in which the concentrated drainage discharged to the drainage passage 26 is used for cooling the spindle assembly 46 of the cutting device 44 is shown, but the spindle assembly of another processing device such as a grinding device is used. You may comprise so that concentrated drainage may be utilized for cooling.

  In the above-described embodiment, the pure water concentration measuring means 22 and 40 are provided in the pure water outflow path 18 and the drain return path 36. However, the pure water concentration measuring means includes the pure water outflow path 18, the drainage path 26, It may be arranged on any one of the pure water return path 32 and the drainage return path 36.

  According to the embodiment described above, the pure water return path 32 for returning the pure water generated by the reverse osmosis membrane modules 4A and 4B to the water supply path 8 upstream from the pressurizing pump 14 is provided. Even when the amount of pure water flowing out to the processing device or the like is small or when the generated pure water is not used in the processing device or the like, it is possible to prevent an increase in water pressure in the pure water outflow path 18.

  As a result, it is possible to prevent a decrease in separability in the reverse osmosis membrane modules 4A and 4B. Moreover, even when the outflow amount of pure water varies, it is possible to prevent the pure water concentration (electrolyte concentration) of pure water generated by the reverse osmosis membrane modules 4A and 4B from deteriorating.

  Further, since a part of the concentrated drainage discharged to the drainage passage 26 is used as cooling water for the spindle assembly 46 of the cutting device 44, it is more economical than conventional cooling systems that use pure water as cooling water. It is.

  Referring to FIG. 2, there is shown a schematic diagram of a cooling system 42A of the processing apparatus according to the second embodiment of the present invention. In the cooling system 42A of the present embodiment, the configuration of the pure water generator 2A is different from that of the first embodiment described above.

  The pure water generator 2A of the present embodiment is different from the first embodiment described above in that the pure water return path 32 of the first embodiment is abolished and a pure water storage tank 66 is installed in the pure water outflow path 18. . In the present embodiment, the pure water generated by the pure water generator 2 </ b> A is stored in the pure water storage space tank 66. The pure water generating apparatus 2A of the present embodiment can simplify the configuration as compared with the first embodiment described above in that the pure water return path 32 is eliminated.

  Since the operation of the cooling system 42A of the processing apparatus of the present embodiment is the same as that of the cooling system 42 of the first embodiment described above, the description thereof is omitted to avoid duplication.

2 Pure water generators 4A, 4B Reverse osmosis membrane module 6 Water supply source 8 Water supply path 14 Pressure pump 18 Pure water outflow path 22, 40 Pure water concentration measuring means 26 Drain path 30 Open / close valve 32 Pure water return path 34, 38 Check valve 36 Drain return path 44 Cutting device 46 Spindle assembly 50 Spindle 52 Cutting blade 58 Cooling water introduction path 60 Cooling water discharge path

Claims (3)

A cooling system for a processing apparatus including a spindle assembly,
A water source,
A reverse osmosis membrane module for separating water supplied from the water supply source into concentrated drainage and pure water;
A water supply path for supplying water from the water supply source to the reverse osmosis membrane module;
A pressure pump provided on the water supply path and pressurizing water supplied to the reverse osmosis membrane module;
A drainage path for draining the concentrated drainage from the reverse osmosis membrane module;
A drain return path branched from the drain path and connected to the upstream side of the pressure pump of the water supply path;
A pure water outflow path through which pure water generated by the reverse osmosis membrane module flows out;
An on-off valve disposed on the drainage path downstream from the branch point of the drainage path and the drainage return path;
A cooling water introduction path branched from the upstream side of the open / close valve of the drainage path or branched from the drainage return path and connected to the spindle assembly to introduce cooling water for cooling the spindle assembly;
A cooling water discharge passage connected to the spindle assembly and upstream of the open / close valve of the drainage passage, and for returning the cooling water discharged from the spindle assembly to the drainage passage;
A cooling system for a processing apparatus, comprising: Further comprising pure water concentration measuring means for measuring the concentration of pure water disposed on any one of the drainage path, drainage return path, or pure water outflow path,
The processing system cooling system according to claim 1, wherein opening and closing of the on-off valve is controlled based on the pure water concentration measured by the pure water concentration measuring means.   The cooling system for a processing apparatus according to claim 1, wherein the processing apparatus is either a cutting apparatus or a grinding apparatus.

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