JP2009029078A - Wire saw device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire-saw device capable of controlling a temperature of slurry, wherein dimensional accuracy of a wafer can be improved by adjusting temperatures in each part of a wire and a guide roller to those suitable to a highly accurate processing. <P>SOLUTION: The wire-saw device 1 is installed with guide rollers 2 and 3, a wire 4 and a device 5 for supplying slurry. The device 5 for supplying slurry is installed with a primary and secondary controlling parts 11 and 12 for controlling temperature of slurry, a primary pipe arrangement 13 through which slurry having temperature controlled by the primary controlling part 11 for controlling temperature of slurry is flown, the secondary pipe arrangement 14 through which slurry having temperature controlled by the secondary controlling part 12 for controlling temperature of slurry is flown, a primary discharging nozzle 15 for discharging the primary slurry which is connected to a down flow site of the primary pipe arrangement 13 and a secondary discharging nozzle 16 for discharging the secondary slurry which is connected to a down flow site of the secondary piper arrangement 14, wherein a temperature of slurry supplied from the primary discharging nozzle 15 for discharging the primary slurry and a temperature of slurry supplied from the secondary discharging nozzle 16 for discharging the secondary slurry can be changed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wire saw device used when a wafer is obtained by cutting an ingot.

Conventionally, when a wafer is obtained by cutting a semiconductor ingot, a quartz ingot, or the like to a predetermined thickness, for example, a wire saw device as disclosed in Patent Document 1 has been used. The wire saw device of Patent Document 1 includes a plurality of guide rollers around which a wire is wound, and a slurry supply device that supplies a slurry obtained by mixing abrasive particles in a liquid such as oil. The slurry supply device includes a heat exchanger that cools the slurry in the tank, a pipe that guides the slurry in the tank to above the guide roller and the wire, and a plurality of discharge nozzles connected to the pipe. These discharge nozzles are respectively arranged toward the portion of the wire before cutting the ingot, the portion after cutting the ingot, and the guide roller. Therefore, according to this wire saw device, when the ingot is pressed against the wire sent by the rotation of the guide roller and cut, the slurry whose temperature is controlled by the heat exchanger is supplied to each part of the wire and the guide roller, respectively. Will be. As a result, it is intended to suppress the deterioration of the dimensional accuracy of the wafer due to the influence of frictional heat generated between the wire and the ingot during cutting.
Japanese Patent No. 29967896

  By the way, when controlling the temperature of slurry like the wire saw apparatus of patent document 1, it becomes possible to supply and cool a slurry with low temperature to the wire whose temperature is increased by frictional heat. However, in this wire saw apparatus, since the slurry of the same temperature is supplied to a wire and a guide roller, each part of a wire and the temperature of a guide roller cannot be controlled independently. Therefore, it is difficult to set the temperature of each part of the wire and the guide roller to a predetermined temperature suitable for high-precision processing, and the dimensional accuracy of the wafer may be lowered.

  The present invention has been made in view of such a point, and the object of the present invention is to separately supply slurry set to a plurality of temperatures in a wire saw apparatus that controls the temperature of the slurry. By doing so, the temperature of each part of the wire and the temperature of the guide roller can be set to a predetermined temperature suitable for high-precision processing, thereby improving the dimensional accuracy of the wafer.

  In order to achieve the above object, according to the present invention, the first and second slurry discharges connected to these pipes by flowing the slurry whose temperature is controlled by the first and second slurry temperature control units to the first and second pipes. Each nozzle was discharged.

  Specifically, the first invention includes a plurality of guide rollers arranged at intervals from each other, a wire wound around these guide rollers, and a slurry supply device for supplying slurry to at least the wire, In the wire saw apparatus configured to obtain a wafer by cutting an ingot with the wire sent by rotating a roller, the slurry supply apparatus includes first and second slurry temperature control units that control the temperature of the slurry. A first pipe through which the slurry controlled by the first slurry temperature control unit flows, a second pipe through which the slurry controlled by the second slurry temperature control unit flows, and a downstream side of the first pipe The first slurry discharge nozzle to be connected and the second slurry discharge nozzle connected to the downstream side of the second pipe A configuration that includes and.

  According to this configuration, the slurry set at different temperatures by the first and second slurry temperature control units flows through the first and second pipes and is discharged from the first and second slurry discharge nozzles. Therefore, depending on the positions of the first and second slurry discharge nozzles, it is possible to supply slurry at a predetermined temperature suitable for each of the portion of the wire after cutting the ingot, the portion before cutting, or the guide roller.

  In 2nd invention, in 1st invention, a 1st slurry discharge nozzle is arrange | positioned so as to correspond to the part after the ingot cutting | disconnection in a wire, and a 2nd slurry discharge nozzle respond | corresponds to the part before the ingot cutting | disconnection in a wire. It is set as the structure arrange | positioned.

  According to this configuration, it is possible to supply the slurry whose temperature is set so that the temperature of the portion of the wire before cutting the ingot becomes a predetermined temperature from the second slurry discharge nozzle. On the other hand, a slurry having a temperature lower than that of the slurry supplied from the second slurry discharge nozzle is supplied from the first slurry discharge nozzle to the portion of the wire after the ingot cutting, and the portion after the cutting can be quickly cooled. It becomes possible.

  In a third invention, in the first invention, the first slurry discharge nozzle is disposed so as to correspond to a portion of the wire after the ingot is cut, and the second slurry discharge nozzle is wound around the portion of the wire after the ingot is cut. It is set as the structure arrange | positioned corresponding to the guide roller to be hung.

  According to this configuration, the portion of the wire after cutting the ingot can be cooled by the slurry supplied from the first slurry discharge nozzle. Moreover, it becomes possible to suppress the temperature rise of the guide roller around which the portion of the wire after the ingot cutting is wound by the slurry supplied from the second slurry discharge nozzle.

  According to a fourth aspect, in the third aspect, a plurality of first slurry discharge nozzles are connected to the first pipe, and a plurality of second slurry discharge nozzles are connected to the second pipe. At least one of the discharge nozzles is disposed so as to correspond to a portion of the wire before the ingot is cut, and at least one of the second slurry discharge nozzles is a roller around which the portion of the wire before the ingot is cut is wound. It is set as the structure arrange | positioned so that it may respond | correspond.

  According to this configuration, the temperature of the portion of the wire before cutting the ingot can be adjusted by the slurry supplied from the first slurry discharge nozzle. Moreover, it becomes possible to adjust the temperature of the guide roller around which the portion of the wire before cutting the ingot is wound by the slurry supplied from the second slurry discharge nozzle.

  According to the first invention, the slurry whose temperature is separately controlled by the first and second slurry temperature control units can be discharged from the first and second slurry discharge nozzles via the first and second pipes, respectively. it can. Thereby, the temperature of each part of a wire and the temperature of a guide roller can be made into the predetermined temperature suitable for a highly accurate process, As a result, the dimensional accuracy of a wafer can be improved.

  According to the second aspect of the invention, the slurry whose temperature is set so that the temperature of the portion of the wire before cutting the ingot becomes a predetermined temperature is supplied from the second slurry discharge nozzle, so that the portion of the wire before cutting the ingot is cut. The temperature can be a predetermined temperature. Moreover, the part after the ingot cutting | disconnection in a wire can be rapidly cooled with the slurry supplied from a 1st slurry discharge nozzle, and the temperature rise of a guide roller can be suppressed. By these things, the dimensional accuracy of a wafer can be improved further.

  According to the third invention, the portion of the wire after the ingot cutting can be quickly cooled by the slurry supplied from the first slurry discharge nozzle, and the guide roller can be cooled by the slurry supplied from the second slurry discharge nozzle. Temperature rise can be suppressed. Thereby, the dimensional accuracy of the wafer can be further improved.

  According to the fourth invention, the temperature of the wire before the ingot cutting can be adjusted by the slurry supplied from the first slurry discharge nozzle, and before the ingot cutting in the wire by the slurry supplied from the second slurry discharge nozzle. It is possible to adjust the temperature of the guide roller around which the portion is wound. Thereby, the dimensional accuracy of the wafer can be further improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

Embodiment 1 of the Invention
FIG. 1 is a schematic configuration diagram of a wire saw device 1 according to Embodiment 1 of the present invention. The wire saw device 1 includes first and second guide rollers 2 and 3, a wire 4 wound around the guide rollers 2 and 3, and a slurry supply device 5 that supplies slurry to the wires 4 and the guide rollers 2 and 3. And a holding mechanism 6 that holds the ingot I above the guide rollers 2 and 3. The ingot I is a cylindrical semiconductor ingot.

  The first guide roller 2 has a columnar main body 2a made of urethane rubber or the like, and a rotary shaft 2b extending substantially horizontally through the center of the main body 2a. Similarly, the second guide roller 3 has a main body 3a and a rotating shaft 3b. The first and second guide rollers 2 and 3 are arranged such that the rotation shafts 2b and 3b are substantially parallel to each other on the same horizontal plane. The first and second guide rollers 2 and 3 are rotationally driven by a driving device (not shown). In addition, a large number of wire guide grooves extending in the circumferential direction are formed on the outer peripheral surfaces of the main body portions 2a and 3a of the guide rollers 2 and 3 at predetermined intervals in the axial direction, although not shown. The wire 4 is fitted in these wire guide grooves. The thickness of the wafer to be obtained is set according to the distance between the wire guide grooves.

  As the wire 4, for example, a piano wire with a predetermined plating can be used, and the diameter is about 120 μm to 180 μm. The wire 4 is supplied from a wire supply reel (not shown), wound spirally so as to fit into the wire guide grooves of the first and second guide rollers 2 and 3, and a wire take-up reel (not shown). Z)).

  The holding mechanism 6 is arranged immediately above the intermediate portion between the first and second guide rollers 2 and 3 and is configured to move the ingot I in the vertical direction.

  The slurry supply device 5 is controlled by a tank 10 for storing slurry, first and second slurry temperature controllers 11 and 12 for controlling the temperature of the slurry, and first and second slurry temperature controllers 11 and 12. First and second pipes 13 and 14 through which the slurry flows, and first and second slurry discharge nozzles 15 and 16 connected to the downstream sides of the first and second pipes 13 and 14, respectively. . The slurry is a well-known one in which abrasive grains are mixed with oil.

  The tank 10 is provided with a stirrer 22 including a screw 20 and a motor 21 that rotationally drives the screw 20. A drain port 10 a is formed at the bottom of the tank 10, and a moving caster 10 b is attached. First and second pumps 23 and 24 are attached to the upper wall portion of the tank 10. The slurry in the tank 10 is sucked up by the first and second pumps 23 and 24.

  The first slurry temperature control unit 11 includes a heat exchanger 30, a temperature sensor 31, and a control unit 32. Water as a heat exchange medium is supplied to the heat exchanger 30 through a water supply pipe 30a, and the water circulated through the heat exchanger 30 is discharged through a drain pipe 30b. Water having a temperature lower than normal temperature is supplied to the water supply pipe 30a. A heater 33 for heating water is provided in the middle of the water supply pipe 30a. The heater 33 is connected to the control unit 32, and can be switched on and off by the control unit 32. Around the heat exchanger 30, a slurry flow pipe 34 through which the slurry flows is provided in contact with the outer surface of the heat exchanger 30. The downstream end of the discharge pipe 23 a extending from the discharge port of the first pump 23 is connected to the upstream side of the slurry circulation pipe 34. The upstream end of the first pipe 13 is connected to the downstream side of the slurry circulation pipe 34. Therefore, the slurry discharged from the first pump 23 changes its temperature by flowing heat with water flowing in the heat exchanger 30 and flows into the first pipe 13. The heat exchange medium supplied to the heat exchanger 30 can be a fluid other than water.

  The temperature sensor 31 is provided in the vicinity of the heat exchanger 30 of the first pipe 13 and is configured to detect the temperature of the slurry flowing through the first pipe 13. The temperature sensor 31 is connected to the control unit 32. A flow meter 36 for measuring the flow rate of the slurry is provided on the downstream side of the temperature sensor 31 of the first pipe 13.

  The control unit 32 is configured to control the heater 33 according to a predetermined program based on the output signal of the temperature sensor 31. That is, when it is necessary to raise the temperature of the slurry, the heater 33 is turned on. Thereby, the hot water heated by the heater 33 flows into the heat exchanger 30, the slurry flowing around the heat exchanger 30 is heated, and the temperature of the slurry flowing through the first pipe 13 rises. On the other hand, when it is necessary to lower the temperature of the slurry, the heater 33 is turned off. As a result, the water supplied to the water supply pipe 30a flows into the heat exchanger 30 while it is cold, the slurry flowing around the heat exchanger 30 is cooled, and the temperature of the slurry flowing through the first pipe 13 decreases. To do. Further, the temperature of the slurry is arbitrarily changed by controlling the amount of water having a temperature lower than the normal temperature flowing into the heater 33 and the water supply pipe 30a.

  The second slurry temperature control unit 12 includes a heat exchanger 40, a temperature sensor 41, and a control unit 42, similar to the first slurry temperature control unit 11. A slurry flow path 44 is provided around the heat exchanger 40. The second pipe 14 is also provided with a temperature sensor 41 and a flow meter 46 as in the first pipe 13.

  The downstream side of the flowmeter 36 of the first pipe 13 is composed of two branch pipes 37 and 38 that extend in two branches. Valves 39 and 39 are provided in the middle of these branch pipes 37 and 38, respectively. By these valves 39, 39, the flow rate of the slurry in the branch pipes 37, 38 can be adjusted independently. The first slurry discharge nozzles 15 and 15 are provided at the downstream ends of the branch pipes 37 and 38, respectively. Both the first slurry discharge nozzles 15, 15 are disposed above the guide wire 4 between the first and second guide rollers 2, 3. The first slurry discharge nozzle 15 of one branch pipe 37 is close to the first guide roller 2 side of the ingot I, and the discharge port is directed to the wire 4. The first slurry discharge nozzle 15 of the other branch pipe 38 is close to the second guide roller 3 side of the ingot I, and the discharge port is directed to the wire 4. That is, the slurry that has circulated through the first pipe 13 is supplied to a portion of the wire 4 before cutting the ingot and a portion after cutting the ingot.

  The downstream side of the flow meter 46 of the second pipe 14 is composed of two branch pipes 47 and 48, similar to the first pipe 13. A valve 49 is provided in the middle of the branch pipes 47 and 48, and second slurry discharge nozzles 16 and 16 are provided in the downstream ends. The second slurry discharge nozzle 16 of one branch pipe 47 is disposed immediately above the first guide roller 2, and the discharge port is directed to the outer peripheral surface of the first guide roller 2. Further, the second slurry discharge nozzle 16 of the other branch pipe 48 is disposed immediately above the second guide roller 3, and the discharge port thereof is directed to the outer peripheral surface of the second guide roller 3.

  A slurry receiver 50 is provided below the first and second guide rollers 2 and 3. The slurry discharged from the first and second slurry discharge nozzles 15, 16 is received by the slurry receiver 50, and then circulates through the return pipe 51 and is returned to the tank 10.

  Next, operation | movement of the wire saw apparatus 1 comprised as mentioned above is demonstrated. When the first and second guide rollers 2 and 3 are rotated clockwise (clockwise in FIG. 1), the wire 4 is sent. On the other hand, when the first pump 23 is operated, the slurry in the tank 10 is sucked up and flows into the slurry distribution pipe 34 of the first slurry temperature controller 11 through the discharge pipe 23a. After the temperature of the slurry flowing into the slurry distribution pipe 34 is adjusted by the heat exchanger 30, the slurry flows through the first pipe 13 and flows through the branch pipes 37 and 38. The slurry that has flowed through one branch pipe 37 is supplied from the first slurry discharge nozzle 15 to the first guide roller 2 side of the traveling wire 4 (the portion after the ingot is cut). The slurry that has flowed through the other branch pipe 38 is supplied from the first slurry discharge nozzle 15 to the second guide roller 3 side of the wire 4 (part before cutting the ingot). The temperature of the slurry at this time is set so that the temperatures of the guide rollers 2 and 3 and the wire 4 are suitable for highly accurate processing.

  Then, the holding mechanism 6 lowers the ingot I and presses it against the wire 4. Then, frictional heat is generated between the wire 4 and the ingot I. In response to this, the temperature of the slurry supplied to the wire 4 is set to a lower temperature by the first slurry temperature control unit 11. Thereby, the temperature of the wire 4 can be quickly lowered.

  At the time of cutting the ingot I, since the ingot I has a cylindrical shape, the contact area between the wire 4 and the ingot I is small in the initial stage of cutting, so the amount of frictional heat is small, and the wire is directed toward the middle of the cutting. The contact area between 4 and the ingot I gradually increases, and the amount of frictional heat generated increases. And from the middle of the cutting to the end, conversely, the contact area between the wire 4 and the ingot I gradually decreases, and the amount of frictional heat generated decreases. In order to correspond to the change in the generation amount of the frictional heat, the first slurry temperature control unit 11 performs control so that the temperature of the slurry is lowered from the initial stage of cutting toward the middle stage. The position of the ingot I by the holding mechanism 6 is used to detect whether the current cutting stage is in the initial stage, middle stage, or final stage.

  Moreover, since the wire 4 cooled by the slurry discharged from the first slurry discharge nozzle 15 is wound around the first guide roller 2, the temperature of the first guide roller 2 does not increase so much. Therefore, the temperature of the slurry discharged from the second slurry discharge nozzle 16 is set higher than the temperature of the slurry discharged from the first slurry discharge nozzle 15 by the second slurry temperature control unit 12. Thereby, the temperature of the 1st guide roller 2 does not fall too much, and becomes temperature suitable for a highly accurate process. Further, the temperature of the second guide roller 3 can be maintained at a similar temperature.

  As described above, according to the wire saw device 1 according to the first embodiment, the portion after the ingot cutting in the wire 4 is cooled by the slurry supplied from the first slurry discharge nozzle 15 and is suitable for high-precision processing. Temperature. Moreover, the temperature of the 1st guide roller 2 and the temperature of the 2nd guide roller 3 can be made into the temperature suitable for a highly accurate process with the slurry supplied from the 2nd slurry discharge nozzle 16. FIG. Thereby, the dimensional accuracy of the wafer can be improved.

  The amount of frictional heat generated at the time of cutting and the temperature change of the first and second guide rollers 2 and 3 vary depending on the size of the ingot I, the feed speed of the wire 4, and the type of slurry. Depending on the condition, the temperature of the slurry can be changed.

  Further, the rotation directions of the first and second guide rollers 2 and 3 may be counterclockwise.

<< Embodiment 2 of the Invention >>
FIG. 2 is a schematic configuration diagram of a wire saw device 1 according to Embodiment 2 of the present invention. Since the wire saw device 1 according to the second embodiment and that of the first embodiment are the same except for the positions of the first and second slurry discharge nozzles 15 and 16, the following embodiments will be described. The same reference numerals are given to the same parts as 1 and the description thereof is omitted, and different parts will be described in detail.

  That is, the first slurry discharge nozzle 15 connected to one branch pipe 37 of the first pipe 13 is disposed immediately above the first guide roller 2, and its discharge port is formed on the outer peripheral surface of the first guide roller 2. Is directed. The first slurry discharge nozzle 15 connected to the other branch pipe 38 is close to the first guide roller 2 side of the ingot I above the guide wire 4 between the first and second guide rollers 2 and 3. The discharge port is directed to the wire 4.

  The second slurry discharge nozzle 16 connected to one branch pipe 47 of the second pipe 14 is disposed immediately above the second guide roller 3, and the discharge port is formed on the outer peripheral surface of the second guide roller 3. Is directed. The second slurry discharge nozzle 16 connected to the other branch pipe 48 is close to the second guide roller 3 side of the ingot I above the guide wire 4 between the first and second guide rollers 2 and 3. The discharge port is directed to the wire 4.

  Next, operation | movement of the wire saw apparatus 1 comprised as mentioned above is demonstrated. When the first and second guide rollers 2 and 3 are rotated clockwise (clockwise in FIG. 2) and the wire 4 is sent to cut the ingot I, the wire 4 is moved to the right side of the ingot I (after the ingot is cut). The temperature rises at (part). In response to this, the first slurry temperature controller 11 lowers the temperature of the slurry. This makes it possible to quickly reduce the temperature of the portion of the wire 4 after cutting the ingot and to increase the temperature of the first guide roller 2 around which the wire 4 having a higher temperature than the second guide roller 3 is wound. It becomes possible to suppress.

  Moreover, since the part before the ingot cutting | disconnection in the wire 4 is wound around the 2nd guide roller 3, the temperature of the 2nd guide roller 3 hardly changes. Moreover, the temperature of the part before the ingot cutting | disconnection in the wire 4 is not so high. Corresponding to this, the temperature of the slurry discharged from the second slurry discharge nozzle 16 is set higher than the temperature of the slurry discharged from the first slurry discharge nozzle 15 by the second slurry temperature control unit 12. .

  As described above, according to the wire saw device 1 according to the second embodiment, the slurry whose temperature is set so that the temperature of the portion of the wire 4 before cutting the ingot becomes a predetermined temperature is used as the second slurry discharge nozzle 16. On the other hand, a slurry having a temperature lower than that of the slurry supplied from the second slurry discharge nozzle 16 is supplied from the first slurry discharge nozzle 15, so that the portion of the wire 4 after cutting the ingot can be quickly cooled. Thereby, the temperature of each part of the wire 4 and the temperature of the guide rollers 2 and 3 can be made into the temperature suitable for a highly accurate process, As a result, the dimensional accuracy of a wafer can be improved.

  In the case where the wire 4 is fed with the rotation directions of the first and second guide rollers 2 and 3 being reversed, the temperature of the slurry supplied from the second slurry discharge nozzle 16 is set to be opposite to the above case. The temperature may be set lower than the temperature of the slurry supplied from one slurry discharge nozzle 15.

  In the first and second embodiments, the case where the semiconductor ingot I is cut by the wire saw device 1 has been described. However, the present invention is not limited to this, and the present invention can also be applied to a case where a quartz ingot is cut.

  Further, the number of each of the first and second slurry discharge nozzles 15 and 16 may be one, or may be three or more.

  As described above, the wire saw device according to the present invention can be applied, for example, when a semiconductor ingot is cut to obtain a wafer.

It is a schematic block diagram of the wire saw apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is a view corresponding to FIG. 1 according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wire saw apparatus 2 1st guide roller 3 2nd guide roller 4 Wire 5 Slurry supply apparatus 11 1st slurry temperature control part 12 2nd slurry temperature control part 13 1st piping 14 2nd piping 15 1st slurry discharge nozzle 16 1st 2 Slurry discharge nozzle I Ingot

Claims (4)

A plurality of guide rollers arranged at intervals from each other, a wire wound around these guide rollers, and a slurry supply device for supplying slurry to at least the wire, and the wire fed by rotating the roller In a wire saw device configured to cut an ingot to obtain a wafer,
The slurry supply apparatus includes:
First and second slurry temperature control units for controlling the temperature of the slurry;
A first pipe through which the slurry controlled by the first slurry temperature control unit flows;
A second pipe through which the slurry controlled by the second slurry temperature control unit flows;
A first slurry discharge nozzle connected to the downstream side of the first pipe;
A wire saw device comprising: a second slurry discharge nozzle connected to the downstream side of the second pipe. The wire saw device according to claim 1,
The first slurry discharge nozzle is disposed so as to correspond to a portion of the wire after cutting the ingot,
The 2nd slurry discharge nozzle is arrange | positioned so that it may correspond to the part before the ingot cutting | disconnection in a wire, The wire saw apparatus characterized by the above-mentioned. The wire saw device according to claim 1,
The first slurry discharge nozzle is disposed so as to correspond to a portion of the wire after cutting the ingot,
The second slurry discharge nozzle is disposed so as to correspond to a guide roller around which a portion of the wire after cutting the ingot is wound. The wire saw device according to claim 3,
A plurality of first slurry discharge nozzles are connected to the first pipe,
A plurality of second slurry discharge nozzles are connected to the second pipe,
At least one of the first slurry discharge nozzles is disposed so as to correspond to a portion of the wire before cutting the ingot,
At least one of the second slurry discharge nozzles is disposed so as to correspond to a roller around which a portion of the wire before ingot cutting is wound.

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