Processing water supply device

Abstract

To provide a processing water supply device capable of suppressing power consumption and shortening time until processing water reaches desired temperature.SOLUTION: A processing water supply device 2 further includes: a first path 22 for guiding processing water sent out from a processing water source 4 to an external path 16b; a second path 24 for guiding the processing water flowing out from the external path 16b to an electric heater 10; and a third path 26 for guiding the processing water flowing out from the electric heater to a processing device. A control unit 12 operates the electric heater to heat the processing water to desired temperature until the processing water guided to the external path takes heat from refrigerant and reaches the desired temperature.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a processing water supplying device that supplies processing water to a processing device including a holding means for holding a workpiece and a processing means for processing the workpiece held by the holding means while supplying processing water to the workpiece. [Background technology]

[0002] A wafer has multiple devices such as ICs and LSIs formed on its surface, separated by planned dividing lines. The back side is ground by a grinding machine to a specified thickness, and then the wafer is divided into individual device chips by a dicing machine. Each of these device chips is used in electrical equipment such as mobile phones and personal computers.

[0003] The grinding device is generally composed of a holding means for holding the wafer, a grinding means having a rotatably mounted grinding wheel with a ring-shaped grinding stone for grinding the wafer held by the holding means, a grinding water supply means for supplying grinding water (e.g., pure water) to the grinding wheel, and a cleaning means for cleaning the wafer, and is capable of grinding the wafer with high precision (see, for example, Patent Document 1).

[0004] A dicing device is generally composed of a holding means for holding a wafer, a cutting means having a rotatably mounted cutting blade for cutting the wafer held by the holding means, a cutting water supply means for supplying cutting water (e.g., pure water) to the cutting blade, and a cleaning means for cleaning the wafer, and is capable of dividing the wafer into individual device chips with high precision (see, for example, Patent Document 2).

[0005] In addition, processing water, including grinding water, cutting water, cleaning water, and cooling water for adjusting the grinding means and cutting means to a constant temperature, used in the grinding device and dicing device, is sent from a processing water source to a temperature adjustment means, where it is adjusted to the desired temperature before being supplied to processing equipment such as the grinding device and dicing device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-158768 [Patent Document 2] Japanese Patent Application Publication No. 2019-145583 Summary of the Invention [Problem to be solved by the invention]

[0007] When grinding or dicing equipment is used in cold regions, the temperature of the processing water from the processing water source may drop below the specified temperature. In such cases, it is necessary to use an electric heater to heat the processing water to the desired temperature. However, the heating capacity of an electric heater corresponds to the power consumption, and the coefficient of performance (heating capacity / power consumption) is a small 1.

[0008] On the other hand, the coefficient of performance of a heat exchanger that exchanges heat by circulating a refrigerant is better than that of an electric heater. However, in a heat exchanger, it takes time for the processing water to reach the desired temperature, which results in poor productivity.

[0009] An object of the present invention is to provide a processing water supply device that can reduce power consumption and shorten the time it takes for processing water to reach a desired temperature. [Means for solving the problem]

[0010] According to the present invention, there is provided the following processing water supply device that solves the above problems. "A processing water supply device that supplies processing water to a processing device including a holding means for holding a workpiece and a processing means for processing the workpiece held by the holding means while supplying processing water to the workpiece, The apparatus comprises a processing water source and a heating control means for heating the processing water delivered from the processing water source and adjusting the temperature to a desired value; The heating control means a refrigerant circulation unit including a compressor that compresses a refrigerant, a condenser that condenses the refrigerant and is provided with an external path that releases heat of the compressed refrigerant to the outside, a variable expansion valve that adjusts the flow rate of the condensed refrigerant, and an evaporator that evaporates the refrigerant and removes heat from the outside; An electric heater and a control unit, a first path for guiding the processing water sent out from the processing water source to the external path, a second path for guiding the processing water flowing out from the external path to the electric heater, and a third path for guiding the processing water flowing out from the electric heater to the processing device, The control unit operates the electric heater to heat the processing water to the desired temperature until the processing water introduced into the external path absorbs heat from the refrigerant and reaches the desired temperature.

[0011] Preferably, a temperature sensor is disposed in the third path, and the control unit determines the temperature difference between the temperature of the processing water detected by the temperature sensor and the desired temperature, operates the electric heater and the refrigerant circulation unit so as to eliminate the temperature difference, and controls the compressor and the variable expansion valve so that the output of the electric heater converges to zero or an arbitrarily small output, ultimately heating the processing water led to the external path to the desired temperature using the heat of the refrigerant. [Effects of the Invention]

[0012] The processing water supply device of the present invention is A processing water supplying device that supplies processing water to a processing device including a holding means for holding a workpiece and a processing means for processing the workpiece held by the holding means while supplying processing water to the workpiece, The apparatus comprises a processing water source and a heating control means for heating the processing water delivered from the processing water source and adjusting the temperature to a desired value; The heating control means a refrigerant circulation unit including a compressor that compresses a refrigerant, a condenser that condenses the refrigerant and is provided with an external path that releases heat of the compressed refrigerant to the outside, a variable expansion valve that adjusts the flow rate of the condensed refrigerant, and an evaporator that evaporates the refrigerant and removes heat from the outside; An electric heater and a control unit, a first path for guiding the processing water sent out from the processing water source to the external path, a second path for guiding the processing water flowing out from the external path to the electric heater, and a third path for guiding the processing water flowing out from the electric heater to the processing device, The control unit operates the electric heater to heat the processing water to the desired temperature until the processing water guided to the external path absorbs heat from the refrigerant and reaches the desired temperature, thereby reducing power consumption and shortening the time it takes for the processing water to reach the desired temperature. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a circuit diagram of a processing water supply device according to the present invention. [Figure 2] 2 is a perspective view of a processing device to which processing water can be supplied from the processing water supply device shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a processing water supplying apparatus according to the present invention will now be described with reference to the drawings.

[0015] (Processing water supply device 2) The processing water supply device 2 shown in Fig. 1 includes a processing water source 4 and a heating control means 6 that heats the processing water delivered from the processing water source 4 and adjusts it to a desired temperature. The processing water source 4 may be composed of a tank that stores processing water such as pure water. The heating control means 6 includes a refrigerant circulator 8, an electric heater 10, and a control unit 12.

[0016] (Refrigerant circulation section 8) The refrigerant circulation unit 8 uses a refrigerant to heat the processing water sent from the processing water source 4. The refrigerant circulation unit 8 includes a compressor 14 that compresses the refrigerant, a condenser 16 that condenses the refrigerant and has an external path that releases the heat of the compressed refrigerant to the outside, a variable expansion valve 18 that adjusts the flow rate of the condensed refrigerant, and an evaporator 20 that evaporates the refrigerant to remove heat from the outside.

[0017] (Compressor 14) Compressor 14 compresses the refrigerant (e.g., an alternative chlorofluorocarbon gas such as R407C) circulating through refrigerant circulation unit 8. As shown in FIG. 1, motor 14a that drives compressor 14 is provided with inverter 14b. Inverter 14b changes the frequency of the power supplied to motor 14a within a predetermined range (e.g., 20 Hz to 120 Hz). This changes the rotation speed of motor 14a, and also changes the rotation speed of compressor 14 within an allowable rotation speed range (between a lower limit and an upper limit). Inverter 14b is electrically connected to control unit 12 and is controlled by control unit 12.

[0018] (Condenser 16) The condenser 16 condenses the refrigerant compressed by the compressor 14. The condenser 16 is formed with a refrigerant passage 16a through which the refrigerant passes and an external passage 16b through which processing water sent from the processing water source 4 passes. The condenser 16 performs heat exchange between the refrigerant in the refrigerant passage 16a and the processing water in the external passage 16b, thereby dissipating heat from the refrigerant compressed by the compressor 14 to the processing water in the external passage 16b, thereby heating the processing water. The refrigerant is condensed by the heat exchange.

[0019] (Variable Expansion Valve 18) The variable expansion valve 18 adjusts the flow rate of the refrigerant circulating through the refrigerant circulation unit 8, and expands the refrigerant condensed by the condenser 16. A motor 18a, which adjusts the opening degree of the variable expansion valve 18, is electrically connected to the control unit 12, and the opening degree of the variable expansion valve 18 is adjusted by the motor 18a based on instructions from the control unit 12.

[0020] (Evaporator 20) The evaporator 20 evaporates the refrigerant expanded by the variable expansion valve 18. The evaporator 20 is formed with a refrigerant passage 20a through which the refrigerant passes, and a heat exchange liquid passage 20b through which a heat exchange liquid such as industrial water supplied from outside the refrigerant circulation unit 8 passes. The evaporator 20 performs heat exchange between the refrigerant in the refrigerant passage 20a expanded by the variable expansion valve 18 and the heat exchange liquid in the heat exchange liquid passage 20b. As a result, the refrigerant absorbs heat from the heat exchange liquid supplied from outside and evaporates.

[0021] (Electric heater 10) The electric heater 10 heats the processing water delivered from the processing water source 4, similar to the refrigerant circulating unit 8. The electric heater 10 is electrically connected to the control unit 12, and the operation of the electric heater 10 is controlled by the control unit 12. That is, the control unit 12 controls the ON / OFF of the electric heater 10 and the amount of heat added from the electric heater 10 to the processing water.

[0022] As shown in Figure 1, processing water delivered from the processing water source 4 is guided to the external path 16b of the condenser 16 via a first path 22. The processing water flowing out from the external path 16b is guided to the electric heater 10 via a second path 24. The processing water flowing out from the electric heater 10 is guided to the processing device via a third path 26. The first path 22 is provided with an on-off valve 28 for opening and closing the first path 22, and the operation of the on-off valve 28 is controlled by the control unit 12. The third path 26 is provided with a temperature sensor 30 for detecting the temperature of the processing water passing through the third path 26, and the detection result of the temperature sensor 30 is sent to the control unit 12.

[0023] (Control unit 12) The control unit 12 is composed of a computer having a processor and memory. The control unit 12 operates the electric heater 10 to heat the processing water to the desired temperature until the processing water guided to the external path 16b of the condenser 16 absorbs heat from the refrigerant and reaches the desired temperature. The control unit 12 also calculates the temperature difference between the processing water temperature detected by the temperature sensor 30 and the desired temperature, operates the electric heater 10 and the refrigerant circulating unit 8 to eliminate the temperature difference, and controls the compressor 14 and the variable expansion valve 18 so that the output of the electric heater 10 converges to zero or an arbitrarily small output, ultimately heating the processing water guided to the external path 16b to the desired temperature using the heat of the refrigerant.

[0024] (Processing equipment 32) 2 shows a processing device 32 to which processing water can be supplied from the processing water supply device 2. The processing device 32 includes a holding means 34 for holding a workpiece such as a wafer W, and a processing means 36 for processing the workpiece held by the holding means 34 while supplying processing water to the workpiece. The wafer W shown in FIGS. 1 and 2 is attached to a dicing tape T whose periphery is fixed to an annular frame F. As shown in FIG. 1, the front surface Wa of the wafer W is partitioned into a plurality of rectangular regions by grid-like planned division lines L, and devices D such as ICs and LSIs are formed in each rectangular region.

[0025] (Holding means 34) As shown in FIG. 2, the holding means 34 has a chuck table 38 that is movable in the X-axis direction and rotatable about the Z-axis direction. Although not shown, the chuck table 38 is processed and fed in the X-axis direction by a ball screw-type X-axis feed means. The chuck table 38 is also rotated about the Z-axis direction by a motor (not shown). The X-axis direction is the direction indicated by the arrow X in FIG. 2, and the Z-axis direction is the direction indicated by the arrow Z in FIG. 2, which is an up-down direction perpendicular to the X-axis direction. The Y-axis direction indicated by the arrow Y in FIG. 2 is a direction perpendicular to the X-axis and Z-axis directions. The XY plane defined by the X-axis and Y-axis directions is substantially horizontal.

[0026] A circular suction chuck 40 is disposed on the upper end portion of the chuck table 38 of the holding means 34. The suction chuck 40 is formed from a porous material such as porous ceramics. The suction chuck 40 is connected to a suction means (not shown). In the holding means 34, the suction means generates a suction force on the upper surface of the suction chuck 40, thereby suction-holding the workpiece placed on the upper surface of the suction chuck 40. A plurality of clamps 42 for fixing the annular frame F are disposed at intervals in the circumferential direction on the periphery of the chuck table 38.

[0027] (Processing means 36) 1, the processing means 36 includes a spindle housing 44 configured to be movable in the Y-axis direction and the Z-axis direction, a spindle 46 rotatably supported by the spindle housing 44, an annular cutting blade 48 attached to the tip of the spindle 46, and a blade cover 50 that covers the cutting blade 48. Although not shown, the spindle housing 44 is indexed and fed in the Y-axis direction by a ball screw type Y-axis feed means, and is cut and fed in the Z-axis direction by a ball screw type Z-axis feed means.

[0028] (Processing water injection means 52) The blade cover 50 is provided with a processing water jetting means 52 that supplies processing water to the workpiece and the cutting blade 48. The processing water jetting means 52 includes a pair of supply ports 54 provided in the upper part of the blade cover 50 and a pair of jet nozzles 56 (only one side is shown) provided in the lower part of the blade cover 50. The pair of supply ports 54 are connected to the third passage 26 of the processing water supply device 2 and are also connected to the pair of jet nozzles 56 via a flow path (not shown) within the blade cover 50. The pair of jet nozzles 56 are spaced apart in the Y-axis direction across the cutting blade 48. The jet nozzles 56 have a plurality of jetting orifices (not shown) spaced apart in the X-axis direction. Processing water is supplied to the pair of supply ports 54 of the processing water jetting means 52 from the third passage 26 of the processing water supply device 2, and the processing water supplied to the pair of supply ports 54 is jetted toward the workpiece and the cutting blade 48 from the multiple jetting orifices of the pair of jet nozzles 56.

[0029] As shown in FIG. 2, the processing device 32 further includes a cassette stage 60 that can be raised and lowered and on which a cassette 58 containing a plurality of workpieces such as wafers W is placed, a carrying-in / out means 64 that pulls out the uncut workpieces from the cassette 58 and carries them out to the temporary storage table 62 and carries the cut workpieces positioned on the temporary storage table 62 into the cassette 58, a first transport means 66 that transports the uncut workpieces that have been carried out from the cassette 58 to the temporary storage table 62 to the chuck table 38 of the holding means 34, an imaging means 68 that images the workpieces held on the chuck table 38, a cleaning means 70 that cleans the cut workpieces, and a second transport means 72 that transports the cut workpieces from the chuck table 38 to the cleaning means 70. Although detailed explanation will be omitted, processing water (e.g., pure water) is also supplied to the cleaning means 70 as cleaning water from the third path 26 of the processing water supply device 2, and the cleaning water is sprayed from the cleaning water spray nozzle of the cleaning means 70 toward the processed workpiece.

[0030] Next, a method of cutting a wafer W as a workpiece using the above-described processing device 32 will be described.

[0031] (holding process) In this embodiment, first, a holding step is performed in which the wafer W is transferred from the cassette 58 to the chuck table 38 and the wafer W is held on the chuck table 38.

[0032] In the holding step, first, the uncut wafer W is carried out from the cassette 58 to the temporary placement table 62 by the carry-in / out means 64. Next, the wafer W is carried from the temporary placement table 62 to the chuck table 38, which is positioned at the transfer position (the position shown in FIG. 2), by the first carrying means 66, and the wafer W is placed on the upper surface of the chuck table 38. Next, a suction force is generated in the suction chuck 40 of the chuck table 38, causing the wafer W to be suction-held on the chuck table 38. In addition, the annular frame F, which supports the wafer W via the dicing tape T, is fixed with a plurality of clamps 42.

[0033] (cutting process) After the holding step, a cutting step is performed in which the wafer W is cut by the cutting blade 48 of the processing means 36.

[0034] In the cutting process, first, the planned dividing line L of the wafer W is aligned in the X-axis direction. At this time, the chuck table 38 is moved by the X-axis feed means to a position directly below the imaging means 68, and the imaging means 68 takes an image of the wafer W. Then, based on the image of the wafer W taken by the imaging means 68, the chuck table 38 is rotated as appropriate, thereby aligning the planned dividing line L of the wafer W in the X-axis direction.

[0035] After the dividing lines L are aligned in the X-axis direction, cutting is performed along the dividing lines L of the wafer W. To do this, the chuck table 38 is moved below the processing means 36 by the X-axis feed means. The cutting blade 48 is rotated in the direction indicated by arrow R1 in FIG. 1. The cutting blade 48 is then lowered by the Z-axis feed means, and the cutting edge of the cutting blade 48 is caused to cut into the wafer W from the top surface to a predetermined depth. At the same time, the chuck table 38 is moved in the X-axis direction by the X-axis feed means. In this manner, cutting is performed along the dividing lines L of the wafer W, forming cut grooves 74 in the wafer W. The cutting blade 48 is indexed and fed in the Y-axis direction by the Y-axis feed means, and the cutting process is repeated to cut all of the dividing lines L aligned in the X-axis direction. Thereafter, the chuck table 38 is rotated by 90 degrees, and cutting and indexing are repeated until all of the division lines L that are perpendicular to the division lines L that have been previously cut are cut.

[0036] When cutting, processing water is sprayed from processing water spraying means 52 onto the area where the wafer W is cut by the cutting blade 48. The processing water sprayed by processing water spraying means 52 is supplied from processing water supply device 2. The processing water is adjusted to a desired temperature in processing water supply device 2 before being supplied to processing water spraying means 52.

[0037] When processing water is supplied from the processing water supply device 2 to the processing device 32, the control unit 12 of the processing water supply device 2 operates the electric heater 10 to heat the processing water to the desired temperature until the processing water, which has been guided from the processing water source 4 to the external path 16b of the condenser 16, absorbs heat from the refrigerant in the refrigerant circulation unit 8 and reaches the desired temperature. The desired temperature of the processing water is registered in advance in the processing device 32 or input into the processing device 32 by the operator.

[0038] The time from when the processing water supplying apparatus 2 starts operating until the refrigerant circulating unit 8 can heat the processing water to the desired temperature is relatively long, and is longer than the time it takes for the electric heater 10 to heat the processing water to the desired temperature. Therefore, the electric heater 10 is operated together with the refrigerant circulating unit 8 to heat the processing water at least until the refrigerant circulating unit 8 can heat the processing water to the desired temperature. This shortens the time from when the processing water supplying apparatus 2 starts operating until the processing water reaches the desired temperature.

[0039] The control unit 12 determines the temperature difference between the temperature of the processing water in the third path 26 detected by the temperature sensor 30 and the desired temperature, and operates the electric heater 10 and the refrigerant circulating unit 8 to eliminate the temperature difference. The control unit 12 also controls the compressor 14 and the variable expansion valve 18 so that the output of the electric heater 10 converges to zero or an arbitrarily small output. The control unit 12 ultimately heats the processing water guided from the processing water source 4 to the external path 16b of the condenser 16 to the desired temperature primarily or solely using the heat of the refrigerant. As described above, the electric heater 10 requires less time to heat the processing water to the desired temperature than the refrigerant circulating unit 8, but the refrigerant circulating unit 8 has a better coefficient of performance than the electric heater 10. Therefore, once the processing water heating capacity of the refrigerant circulating unit 8 reaches a certain level after the processing water supply device 2 starts operating, the output of the electric heater 10 is reduced. This reduces power consumption.

[0040] As described above, in the processing water supply device 2 of this embodiment, the processing water introduced from the processing water source 4 to the external path 16b of the condenser 16 absorbs heat from the refrigerant in the refrigerant circulation unit 8 and reaches the desired temperature by operating the electric heater 10 to heat the processing water to the desired temperature, thereby shortening the time it takes for the processing water to reach the desired temperature. Furthermore, because the processing water is ultimately heated to the desired temperature by the heat of the refrigerant, power consumption can be reduced.

[0041] In the present embodiment, the processing apparatus 32 (dicing apparatus) equipped with a cutting blade 48 has been described as an example of the processing apparatus to which processing water is supplied from the processing water supply apparatus 2. However, the processing apparatus to which processing water can be supplied from the processing apparatus 32 is not limited to the above-described processing apparatus 32 (dicing apparatus), and may be, for example, a grinding apparatus that grinds a workpiece such as a wafer. [Explanation of symbols]

[0042] 2: Processing water supply device 4: Processing water source 6: Heating control means 8: Refrigerant circulation section 10: Electric heater 12: Control unit 14: Compressor 16: Condenser 16b: External Route 18: Variable expansion valve 20: Evaporator 22: First Route 24: Second Path 26: The Third Path 30:Temperature sensor 32: Processing equipment 34: Holding means 36: Processing means

Claims

1. A processing water supplying device that supplies processing water to a processing device including a holding means for holding a workpiece and a processing means for processing the workpiece held by the holding means while supplying processing water to the workpiece, The apparatus comprises a processing water source and a heating control means for heating the processing water delivered from the processing water source and adjusting the temperature to a desired value; The heating control means a refrigerant circulation unit including a compressor that compresses a refrigerant, a condenser that condenses the refrigerant and is provided with an external path that releases heat of the compressed refrigerant to the outside, a variable expansion valve that adjusts the flow rate of the condensed refrigerant, and an evaporator that evaporates the refrigerant and removes heat from the outside; An electric heater and a control unit, a first path for guiding the processing water sent out from the processing water source to the external path, a second path for guiding the processing water flowing out from the external path to the electric heater, and a third path for guiding the processing water flowing out from the electric heater to the processing device, The control unit of the processing water supply device operates the electric heater to heat the processing water to a desired temperature until the processing water guided to the external path absorbs heat from the refrigerant and reaches the desired temperature.

2. The processing water supply device of claim 1, wherein a temperature sensor is disposed in the third path, and the control unit determines the temperature difference between the temperature of the processing water detected by the temperature sensor and the desired temperature, operates the electric heater and the refrigerant circulation unit so as to eliminate the temperature difference, and controls the compressor and the variable expansion valve so that the output of the electric heater converges to zero or an arbitrarily small output, thereby ultimately heating the processing water led to the external path to the desired temperature using the heat of the refrigerant.

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