JP4608074B2 - Vacuum generation mechanism of processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum generation mechanism equipped in a processing apparatus such as a grinding apparatus for grinding a workpiece such as a semiconductor wafer or a cutting apparatus for cutting a workpiece.
[0002]
[Prior art]
2. Description of the Related Art Processing devices such as a grinding device for grinding a workpiece such as a semiconductor wafer and a cutting device for cutting a workpiece include a chuck table that sucks and holds the workpiece. The chuck table is connected to a vacuum generation mechanism that applies a suction force to a workpiece to be held. In the vacuum generation mechanism, a water-sealed vacuum pump that operates in a non-contact state between a casing and an impeller is generally used as a vacuum pump that generates vacuum.
[0003]
[Problems to be solved by the invention]
Thus, the above-described water-sealed vacuum pump needs to constantly supply cold water of about 20 ° C. as sealed water and discharge the amount of sealed water corresponding to the supply amount. The cold water supplied to the water-sealed vacuum pump as sealed water requires an amount of about 5 liters (5 liters / minute) per minute and is consumed in a considerably large amount. Therefore, by circulating and using the sealed water discharged from the water-sealed vacuum pump, the consumption of cold water can be saved. However, when the discharged sealed water is used by circulation, the sealed water is circulated. Since the temperature rises by 2 ° C to 3 ° C per minute, the critical temperature (50 ° C) at which the water-sealed vacuum pump operates normally will be reached in less than 10 minutes, making it difficult to operate continuously for a long time. Become. In order to solve such a problem, a heat exchanger for cooling the sealed water circulating in the circulation path may be disposed. However, the sealed water circulating through the water-sealed vacuum pump evaporates. It is necessary to always supply cold water to make up for the evaporation.
[0004]
The present invention has been made in view of the above-described facts, and a main technical problem thereof is to provide a vacuum generation mechanism of a processing apparatus that can be configured as a complete circulation type without the need to supply cold water.
[0005]
[Means for Solving the Problems]
In order to solve the main technical problem, according to the present invention, in a vacuum generation mechanism of a processing apparatus that applies a suction force to a chuck table that holds a workpiece,
A water-sealed vacuum pump having a suction port, a discharge port and a water supply port;
A suction path that communicates the suction port and the chuck table, and sucks a part of the air and work water supplied to the workpiece through the chuck table;
A drainage tank that communicates with the outlet and stores sealed water and processing water discharged from the outlet;
A circulation path that communicates with the drainage tank and the water supply port and circulates the mixed water in which the sealed water stored in the drainage tank and the processed water are mixed as sealed water in the water-sealed vacuum pump;
A circulating water feed pump disposed in the circulation path;
A heat exchanger for cooling the mixed water that is disposed in the circulation path and circulates to the water-sealed vacuum pump;
A water supply path that communicates with the water supply port and supplies cold water as sealed water to the water-sealed vacuum pump;
An on-off valve disposed in the water supply path ,
When the water-sealed vacuum pump is started, the on-off valve is opened and the water-sealed vacuum pump is operated to supply cold water from the water supply path,
When a predetermined amount of cold water is supplied as sealed water from the water supply path, the on-off valve is closed and the circulating water feed pump is operated, and the mixed water in the drainage tank is supplied to the circulation path and the A vacuum generation mechanism of a processing apparatus is provided, wherein the vacuum supply mechanism is supplied as sealed water to the water supply port of the water-sealed vacuum pump through a heat exchanger .
[0006]
In addition, according to the present invention, the cooling water of the heat exchanger is configured such that the processing water supplied to the workpiece flows into the heat exchanger as a cooling medium. A vacuum generation mechanism of the processing apparatus according to 1 is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a vacuum generation mechanism of a machining apparatus configured according to the present invention will be described in detail with reference to the accompanying drawings.
[0008]
FIG. 1 shows a perspective view of a dicing apparatus as a processing apparatus provided with a vacuum generating mechanism configured according to the present invention.
The dicing apparatus in the illustrated embodiment includes a device housing 2 having a substantially rectangular parallelepiped shape. In the apparatus housing 2, a chuck table 3 for holding a workpiece is disposed so as to be movable in a direction indicated by an arrow X that is a cutting feed direction. The chuck table 3 includes a suction chuck support 31 and a suction chuck 32 mounted on the suction chuck support 31, and is a workpiece on a mounting surface that is a surface of the suction chuck 32. For example, a disk-shaped semiconductor wafer is held by a suction action of a vacuum generated by a vacuum generation mechanism described later. The chuck table 3 is configured to be rotatable by a rotation mechanism (not shown). The specific configurations of the chuck table 3 and the vacuum generation mechanism will be described later in detail.
[0009]
The dicing apparatus in the illustrated embodiment includes a spindle unit 4 as cutting means. The spindle unit 4 is mounted on a moving base (not shown) and is adjusted to move in a direction indicated by an arrow Y that is an indexing direction and a direction indicated by an arrow Z that is a cutting direction. A rotary spindle 42 supported and rotated by a rotary drive mechanism (not shown) is provided, and a cutting blade 43 attached to the rotary spindle 42 is provided. A machining water supply nozzle 44 is provided on both sides of the cutting blade 43, and the machining water is supplied from the machining water supply nozzle 44 to the workpiece that is sucked and held by the suction chuck 32. ing.
[0010]
The dicing apparatus in the illustrated embodiment images the surface of the workpiece held on the surface of the suction chuck 32 that constitutes the chuck table 3, detects the region to be cut by the cutting blade 43, and cuts the groove. The image pickup mechanism 5 for confirming the state is provided. The imaging mechanism 5 is composed of optical means such as a microscope and a CCD camera. In addition, the dicing apparatus includes a display unit 6 that displays an image captured by the imaging mechanism 5.
[0011]
The dicing apparatus in the illustrated embodiment includes a cassette 7 for stocking a semiconductor wafer 8 as a workpiece. The semiconductor wafer 8 is supported on the support frame 9 by the tape 10 and is accommodated in the cassette 7 while being supported by the support frame 9. The cassette 7 is placed on a cassette table 71 arranged so as to be movable up and down by lifting means (not shown).
[0012]
The dicing apparatus in the illustrated embodiment is a workpiece that carries a semiconductor wafer 8 (a state supported by a support frame 9 with a tape 10) as a workpiece housed in a cassette 7 to a workpiece placement region 11. The unloading means 12, the workpiece conveying means 13 for conveying the semiconductor wafer 8 unloaded by the workpiece unloading means 12 onto the chuck table 3, and the semiconductor wafer 8 cut by the chuck table 3 are cleaned. The cleaning means 14 and the cleaning / conveying means 15 for conveying the semiconductor wafer 8 cut by the chuck table 3 to the cleaning means 14 are provided.
[0013]
Next, the processing operation of the above-described dicing apparatus will be briefly described.
A semiconductor wafer 8 supported by a support frame 9 accommodated in a predetermined position of the cassette 7 via a tape 10 (hereinafter, a semiconductor wafer 8 supported by the support frame 9 by the tape 10 is simply referred to as a semiconductor wafer 8). ) Is positioned at the unloading position when the cassette table 71 moves up and down by a lifting means (not shown). Next, the workpiece unloading means 12 is advanced and retracted to unload the semiconductor wafer 8 positioned at the unloading position to the workpiece placement region 11. The semiconductor wafer 8 transported to the workpiece mounting area 11 is transported to the mounting surface of the suction chuck 32 constituting the chuck table 3 by the turning operation of the workpiece transporting means 13, and is subjected to a vacuum generating mechanism described later. It is sucked and held by the suction chuck 32 by the suction action of the generated vacuum. The chuck table 3 that sucks and holds the semiconductor wafer 8 in this way is moved to a position immediately below the imaging mechanism 5. When the chuck table 3 is positioned immediately below the image pickup mechanism 5, a cutting line formed on the semiconductor wafer 8 is detected by the image pickup mechanism 5, and is moved and adjusted in the arrow Y direction, which is the indexing direction of the spindle unit 4, so as to have a precise position. Matching work is performed.
[0014]
Thereafter, while rotating the cutting blade 43 in a predetermined direction, the processing water is supplied from the processing water supply nozzle 44, and the chuck table 3 that sucks and holds the semiconductor wafer 8 is shown in the direction indicated by the arrow X (the cutting blade). The semiconductor wafer 8 held on the chuck table 3 is cut along a predetermined cutting line (street) by the cutting blade 43 by moving at a predetermined cutting feed rate in a direction orthogonal to the rotation axis 43. That is, the cutting blade 43 is mounted on the spindle unit 4 that is moved and adjusted in the direction indicated by the arrow Y that is the indexing direction and the direction indicated by the arrow Z that is the cutting direction, and is rotationally driven. Is moved in the cutting feed direction along the lower side of the cutting blade 43, so that the semiconductor wafer 8 held on the chuck table 3 is cut along a predetermined cutting line by the cutting blade 43. When cut along the cutting line, the semiconductor wafer 8 is divided into individual semiconductor chips. The divided semiconductor chips are not separated by the action of the tape 10, and the state of the semiconductor wafer 8 supported by the frame 9 is maintained. After the semiconductor wafer 8 has been cut in this manner, the chuck table 3 holding the semiconductor wafer 8 is first returned to the position where the semiconductor wafer 8 is sucked and held, and is generated by a vacuum generation mechanism described later. The vacuum action is cut off, and the suction holding of the semiconductor wafer 8 is released. Next, the semiconductor wafer 8 is transferred to the cleaning unit 14 by the cleaning transfer unit 15 and cleaned there. The semiconductor wafer 8 cleaned in this way is carried out to the workpiece placement area 11 by the workpiece conveying means 13. Then, the semiconductor wafer 8 is stored in a predetermined position of the cassette 7 by the workpiece unloading means 12.
[0015]
Next, an embodiment of the above-described chuck table 3 and vacuum generation mechanism will be described with reference to FIG.
The suction chuck support 31 that constitutes the chuck table 3 is formed in a disk shape from a metal material such as stainless steel, and a rotary shaft 311 protrudes from the center of the lower surface thereof. A circular recess 312 having an open top is formed on the upper surface of the suction chuck support 31, and the recess 312 communicates with a communication path 313 provided in the rotary shaft 311. The suction chuck 32 constituting the chuck table 3 is formed of a porous ceramic disk and is fitted in a recess 312 formed on the suction chuck support base 31. In the chuck table 3 configured as described above, a communication path 313 provided in the rotary shaft portion 311 is communicated with the vacuum generation mechanism 100. On both sides of the movement path of the chuck table 3, trays 45 for receiving the processing water supplied from the processing water supply nozzle 44 to the semiconductor wafer 8, which is a workpiece held on the chuck table 3, are arranged. It is installed.
[0016]
The vacuum generation mechanism 100 in the illustrated embodiment includes a water-sealed vacuum pump 110 as a vacuum generation source. The water-sealed vacuum pump 110 includes a suction port 111, a discharge port 112, and a water supply port 113, and introduces sealed water from the water supply port 113, and air and a workpiece to be processed through the chuck table 3 from the suction port 111. A part of the processed water supplied to the object is sucked, and the sealed water, sucked air and processed water are discharged from the discharge port 112. The suction port 111 of the water-sealed vacuum pump 110 configured as described above is communicated with the communication path 313 provided in the rotation shaft portion 311 of the suction chuck support base 31 via the suction path 120. The suction path 120 is provided with a check valve 121 that allows flow from the communication passage 313 side to the suction port 111 side but blocks flow from the suction port 111 side to the communication passage 313 side. Further, the discharge port 112 of the water-sealed vacuum pump 110 communicates with the drain tank 140 via the drain path 130. The drainage tank 140 introduces the sealed water discharged from the discharge port 112 of the water-sealed vacuum pump 110, the sucked air and the processed water, separates the sealed water, the processed water and the air, and releases the air to the atmosphere. At the same time, the mixed water of the sealed water and the processed water is stored. A discharge pipe 141 is connected to the lower portion of the drain tank 140, and an open / close valve 142 is disposed in the discharge pipe 141. Further, one end of an overflow pipe 143 is connected to the upper side from the central portion of the drain tank 140, and the other end of the overflow pipe 143 is connected to the discharge side from the on-off valve 142 in the discharge pipe 141.
[0017]
The water supply port 113 of the water-sealed vacuum pump 110 communicates with a water supply tank 160 that stores cold water such as city water via a water supply path 150. An electromagnetic on-off valve 151 is disposed in the water supply path 150. The electromagnetic on-off valve 151 is closed as shown in the figure when deenergized, and is opened when energized.
[0018]
The vacuum generation mechanism 100 in the illustrated embodiment includes a circulation path 170 that connects the lower part of the drainage tank 140 and the water supply port 113 through the electromagnetic on-off valve 151 in the water supply path 150. A circulating water feed pump 171 and a heat exchanger 180 are disposed in the circulation path 170. A circulation path 170 is connected to the cooled passage 181 of the heat exchanger 180, and the tray 45 receives one end of the processing water supplied to the workpiece held on the chuck table 3 in the cooling passage 182 of the heat exchanger 180. Is connected to the other end of the processed water discharge pipe 190. As described above, the heat exchanger 180 in the illustrated embodiment is configured such that the processing water supplied to the workpiece is introduced as a cooling medium. The water-sealed vacuum pump 110, the electromagnetic on-off valve 151, and the circulating water supply pump 171 are controlled by control means (not shown).
[0019]
The vacuum generation mechanism 100 in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
When the operation of the vacuum generation mechanism 100 is instructed by a control means (not shown), the electromagnetic on-off valve 151 is urged to open, and the water ring vacuum pump 110 is operated. As a result, the cold water in the water supply tank 160 is supplied as sealed water to the water supply port 113 of the water-sealed vacuum pump 110 through the water supply path 150. On the other hand, when the water-sealed vacuum pump 110 is activated, the water supply port 113 becomes negative pressure, and the air and the workpiece are passed through the suction path 120, the communication path 313 and the recess 312 of the chuck table 3, and the suction chuck 32 including a porous ceramic disk. A part of the supplied processing water is sucked. The sealed water, the processed water, and the air thus introduced into the water-sealed vacuum pump 110 are discharged from the discharge port 112 to the drain tank 140 through the drain path 130. Sealed water, processed water and air discharged to the drainage tank 140 are separated into gas and liquid here, the air is released to the atmosphere, and the sealed water and processed water are stored in the drainage tank 140 as mixed water.
[0020]
When a predetermined amount of cold water is supplied as sealed water by the above operation, the electromagnetic on-off valve 151 is de-energized and closed by a control means (not shown) and the circulating water feed pump 171 is operated. As a result, the mixed water of the sealed water in the drain tank 140 and the processed water is supplied as sealed water to the water supply port 113 of the water-sealed vacuum pump 110 through the circulation path 170 and the cooled passage 181 of the heat exchanger 180. . When the mixed water passes through the cooled passage 181 of the heat exchanger 180, the used processing water received by the tray 45 flows through the processing water discharge pipe 190 in the cooling passage 182 of the heat exchanger 180. Therefore, the mixed water is cooled by this processing water. As described above, the mixed water supplied as the sealed water to the water-sealed vacuum pump 110 is cooled by passing through the heat exchanger 180, so that the temperature rise of the circulating mixed water can be prevented. In the illustrated embodiment, since the processing water supplied to the workpiece held on the chuck table 3 is used as a cooling medium for cooling the mixed water in the heat exchanger 180, the cooling water is used. Since there is no need to provide the supply means or the air cooling means, the cost can be reduced. In addition, the mixed water evaporates while the mixed water is circulating through the water-sealed vacuum pump 110 as sealed water as described above, but in the illustrated embodiment, the processing supplied to the workpiece as described above. Part of the water is sucked into the water-sealed vacuum pump 110 and mixed into the mixed water in the drain tank 140, so that the above-mentioned evaporation can be supplemented. That is, the amount of processing water sucked into the water-sealed vacuum pump 110 is about 10 to 20 cc (10 to 20 cc / min) per minute, and can sufficiently compensate for the evaporation. Therefore, it is not necessary to supply cold water during the operation of the water-sealed vacuum pump 110 with the mixed water, and a complete circulation type can be configured. As described above, in the illustrated embodiment, the complete circulation type vacuum generation mechanism 100 can be configured, so that the cold water supplied by opening the electromagnetic on-off valve 151 is supplied at a predetermined amount when the water-sealed vacuum pump 110 is started. Since it only has to be replenished, the consumption of cold water can be greatly reduced.
[0021]
As mentioned above, although this invention was demonstrated based on embodiment of illustration, this invention is not limited only to embodiment. For example, in the embodiment, the example in which the circulating water supply pump 171 is disposed in the circulation path 170 has been described. However, when the capacity of the water ring vacuum pump 110 is large, this pump is not necessarily required. Moreover, although the example which applied this invention to the dicing apparatus as a cutting device was shown in embodiment, this invention is also applicable to the other processing apparatus which uses process water, such as a grinding device.
[0022]
【The invention's effect】
Since the vacuum generation mechanism of the machining apparatus according to the present invention is configured as described above, the following operational effects can be obtained.
[0023]
That is, according to the present invention, the heat exchanger is disposed in a circulation path for circulating the mixed water of the sealed water and the processing water stored in the drain tank to the water-sealed vacuum pump to cool the mixed water, Since a part of the processing water supplied to the workpiece is sucked, it is possible to compensate for the consumption due to evaporation of the sealed water, and a completely circulating vacuum generation mechanism that does not require replenishment of cold water during operation. Can be configured. Therefore, since a predetermined amount of cold water has only to be replenished when the water-sealed vacuum pump is activated, the consumption of cold water can be greatly reduced.
[0024]
According to the present invention, since the used processing water supplied to the workpiece held on the chuck table is used as the cooling medium introduced into the heat exchanger, the cooling water supply means or Since it is not necessary to provide an air cooling means, cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of a dicing apparatus as a processing apparatus to which a vacuum generating mechanism according to the present invention is applied.
FIG. 2 is a block diagram of a vacuum generation mechanism configured according to the present invention.
[Explanation of symbols]
2: Device housing 3: Chuck table 31: Adsorption chuck support base 32: Adsorption chuck 4: Spindle unit 41: Spindle housing 42: Spindle spindle 43: Cutting blade 5: Imaging mechanism 6: Display means 7: Cassette 71: Cassette table 8 : Semiconductor wafer 9: Support frame 10: Tape 11: Workpiece placement area 12: Workpiece unloading means 13: Workpiece conveying means 14: Cleaning means 15: Cleaning and conveying means 100: Vacuum generating mechanism 110: Water seal Vacuum pump 111: Water-sealed vacuum pump suction port 112: Water-sealed vacuum pump discharge port 113: Water-sealed vacuum pump water supply port 120: Suction route 121: Check valve 130: Drainage route 140: Drainage Tank 141: Discharge pipe 142: On-off valve 143: Overflow pipe 150: Supply Path 151: solenoid valve 160: water tank 170: circulation route 171: circulating water feed pump 180: heat exchanger 181: heat exchanger of the cooling passages 182: cooling passages of the heat exchanger 190: processing water discharge pipe

Claims (2)

In a vacuum generation mechanism of a processing apparatus that applies a suction force to a chuck table that holds a workpiece,
A water-sealed vacuum pump having a suction port, a discharge port and a water supply port;
A suction path that communicates the suction port and the chuck table, and sucks a part of the air and work water supplied to the workpiece through the chuck table;
A drainage tank that communicates with the outlet and stores sealed water and processing water discharged from the outlet;
A circulation path that communicates with the drainage tank and the water supply port and circulates the mixed water in which the sealed water stored in the drainage tank and the processed water are mixed as sealed water in the water-sealed vacuum pump;
A circulating water feed pump disposed in the circulation path;
A heat exchanger for cooling the mixed water that is disposed in the circulation path and circulates to the water-sealed vacuum pump;
A water supply path that communicates with the water supply port and supplies cold water as sealed water to the water-sealed vacuum pump;
An on-off valve disposed in the water supply path ,
When the water-sealed vacuum pump is started, the on-off valve is opened and the water-sealed vacuum pump is operated to supply cold water from the water supply path,
When a predetermined amount of cold water is supplied as sealed water from the water supply path, the on-off valve is closed and the circulating water feed pump is operated, and the mixed water in the drainage tank is supplied to the circulation path and the A vacuum generation mechanism for a processing apparatus, wherein the vacuum supply mechanism is supplied as sealed water to the water supply port of the water-sealed vacuum pump through a heat exchanger . The vacuum generation of the processing apparatus according to claim 1, wherein the processing water supplied to the workpiece is configured to flow into the heat exchanger as a cooling medium in the cooling passage of the heat exchanger. mechanism.

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