JP2017118010A - Bandsaw cutting device and cutting method of silicon crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bandsaw cutting device excellent in cutting accuracy when cutting a workpiece such as a silicon crystal, and capable of prolonging the life of the bandsaw.SOLUTION: In a bandsaw cutting device having a biaxial bandsaw pulley including a resin layer on the outer peripheral surface, and a bandsaw rotary driven by the bandsaw pulley, the bandsaw pulley includes a groove having a width of 4-10 mm, a depth of 3 mm or more and the thickness of 70% or less that of the resin layer, in a region including the center position in the width direction of a region where the bandsaw pulley and bandsaw come into contact.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a band saw cutting apparatus and a silicon crystal cutting method.

  When the silicon crystal (ingot) produced by the Czochralski (CZ) method, etc. is cut into cone-shaped ends (top portion and tail portion) to make a block, or when a wafer sample is taken from the block A band saw cutting device or the like is used for cutting processing.

  Here, FIG. 10 shows an outline of an example of a conventional general band saw cutting device. As shown in FIG. 10, the band saw cutting apparatus 101 includes an endless belt-shaped band saw (blade) 102 composed of a blade abrasive grain portion 105 formed by gluing diamond abrasive grains to the end of a thin base metal 106. It is stretched between the band saw pulleys 103 and 103 ′. The band saw 102 is driven by the rotation of the band saw pulleys 103 and 103 ′, and the ingot 108 is cut by the blade abrasive grain portion 105 of the band saw 102. Usually, mechanisms (static pressure pads 104, 104 ') for guiding the traveling direction of the band saw are provided at both ends of the band saw pulleys 103, 103'.

  Patent Document 1 describes that a belt drive, particularly a pulley of a band saw, is provided with a plurality of circumferential grooves parallel to the traveling direction of the band saw along the outer peripheral surface of the pulley in order to perform traveling stably. ing. This circumferential groove is effective to some extent for stabilizing the traveling direction, but it is sufficient to receive external force like a band saw and to deflect the belt etc. in the axial direction of the pulley by this external force. It is described as not valid. Furthermore, there is no description of any conditions for defining the shape and size such as the width and depth of the circumferential groove.

  Further, in the band saw cutting device, in order to obtain a good sharpness and high cutting accuracy, it is necessary to suppress the fluctuation of the base metal during the ingot cutting. For this purpose, in Patent Document 2, a base plate having a concave pattern provided on one surface of the two surfaces of the base metal and a convex pattern provided at a position corresponding to the concave pattern is provided on the other surface. Used. According to the uneven pattern, the base metal has excellent rigidity and the vibration is reduced. In Patent Document 2, the depth and height of the unevenness are both about 5 to 500 μm.

  However, as shown in Patent Document 3, since the distance between the static pressure pad and the band saw is adjusted to 10 to 50 μm, if the base metal has unevenness extending to several tens to several hundreds of μm, It is difficult to adjust the gap between the pressure pad and the band saw. For this reason, it is difficult to sufficiently adjust the static pressure pad, and it is difficult to obtain a straight running stability at the time of cutting the silicon crystal. Here, the straightness is a property that the traveling direction of the band saw is maintained when cutting a work such as silicon crystal, and if the straightness is good, high cutting accuracy can be realized.

Japanese Patent Laid-Open No. 11-82691 JP 2006-320983 A JP 2009-154346 A Japanese Patent No. 2681106 JP 2004-160579 A

  Band saws (electrodeposited band saws) are made of thin steel, such as SUS, and are placed into the endless band by cutting into a predetermined length after joining, back-staking, etc., and joining the ends by plasma welding. ing. Further, a curvature is given in the longitudinal direction of the band saw. Waisting is performed to remove distortion of the base metal, but it is difficult to averagely stabilize the base metal having the entire circumference of 2000 mm to 6000 mm. For this reason, the conventional electrodeposition band saw processing is used for cutting small workpieces, and there is a problem that cutting accuracy cannot be obtained with large workpieces (see Patent Documents 4 and 5). ).

  Therefore, the relationship between cutting accuracy and band saw shape was investigated for the purpose of application to large workpieces. First, an unused band saw 102 is set in the band saw cutting apparatus 101, and the shape of the base metal 106 of the band saw 102 is measured with a measuring instrument (measuring element) such as a pick gauge without the static pressure pads 104 and 104 ′. Measured up and down along the base metal (measured without being affected by the static pressure pad). FIG. 11 shows a band saw cutting apparatus without a static pressure pad, and FIG. 12 shows a shape measuring portion of the band saw 102 in the vertical direction. After measuring the base metal shape of the band saw without the static pressure pad, the static pressure pads 104 and 104 'were set and the ingot 108 was cut, and the displacement of the band saw 102 at the time of cutting was measured.

  In a situation where no static pressure pad is provided, the measurement surface for measuring the shape of the base metal 106 of the band saw 102 is outside the ring of the band saw 102 as shown in FIG. As a result of the measurement, it was found that the shape of the base metal 106 of the band saw 102 has two types as shown in FIGS. Based on the rear surface 115 of the static pressure pad, the shape shown in FIG. 13 is a concave shape (concave surface), and the shape shown in FIG. 14 is a convex shape (convex surface).

  The static pressure pads 104 and 104 ′ were attached to the band saw cutting device 101 to adjust the gap between the static pressure pad and the band saw 102 for each of the case where the base metal 106 of the band saw 102 was concave and convex. Further, as shown in FIG. 15, a blade sensor (displacement sensor) 30 is attached to position the band saw 102 and the blade sensor 30, and the distance L between the band saw 102 and the blade sensor 30 when the ingot 108 is cut is determined by the blade sensor 30. Measured with Then, the interval in the state where positioning was performed was set to displacement = 0, and the increase / decrease in the interval during ingot cutting was expressed as blade displacement.

  First, FIG. 16 shows an outline of the relationship between the number of cuttings of the ingot 108 and the blade displacement when the shape of the base metal 106 of the band saw 102 is concave. 16-20, one peak or valley represents the blade displacement during one cut. FIG. 17 schematically shows the blade displacement at each stage of the life of the band saw 102. As shown in FIG. 17, the blade displacement is relatively small at the beginning of life, and it is possible to correct the blade displacement direction (positive or negative) by performing blade edge dressing, but the displacement amount gradually increases, At the end of life, blade displacement increases, cutting accuracy deteriorates, and eventually the band saw breaks.

  Next, FIG. 18 shows an outline of the relationship between the number of cuts of the ingot 108 and the blade displacement when the shape of the base metal 106 of the band saw 102 is a convex shape. FIG. 19 schematically shows the blade displacement at each stage of the life of the band saw 102. As shown in FIG. 18, when the shape of the base metal 106 of the band saw 102 is a convex shape, it has been found that the blade displacement is relatively small compared to the concave shape. Furthermore, as shown in FIG. 19, the blade displacement is not always negative in all stages of life, but the blade displacement is maintained almost positive.

  However, even if the shape of the base metal 106 of the band saw 102 is initially a convex shape, it tends to become a concave shape during the life, and once it becomes a concave shape, the concave shape is likely to be maintained thereafter. This is shown in FIG. In b3 of FIG. 20, the base metal 106 has a concave shape, and as a result, the blade displacement tends to be negative.

  Then, comparing the case of the concave shape and the convex shape, it was found that the convex shape has better straightness at the time of cutting the ingot and the life of the band saw 102 is extended. On the other hand, in the concave shape, the straightness at the time of cutting the ingot is poor, and the cut sample tends to be thick. Further, it was found that even in the case of the convex band saw 102 in the initial stage, when the number of times of cutting increases, it becomes easy to form a concave shape, and the straightness at the time of ingot cutting also deteriorates.

  These are shown schematically in FIG. 21 (in the case of a concave shape) and FIG. 22 (in the case of a convex shape). In the case of the convex shape shown in FIG. 22, when the distance between the front surface 114 and the rear surface 115 of the static pressure pad 104 is appropriately adjusted, the shape of the band saw 102 is convex as shown in FIGS. 22 (a) and 22 (b). The cutting edge becomes a substantially straight state, the cutting edge also faces the direction of zero displacement (FIG. 22C), and the ingot can be cut with high cutting accuracy. In addition, the life of the band saw is extended.

  On the other hand, in the case of the concave shape shown in FIG. 21, as shown in FIGS. 21 (a), (b) and (c), even if the static pressure pad is adjusted appropriately, the cutting edge is in the negative displacement direction. The cutting of the ingot tends to become unstable, the cutting accuracy is lowered, and the life of the band saw is also shortened.

  From these facts, it was found that a means for controlling the shape of the band saw to a convex shape is necessary in a state where the band saw 102 is set on the band saw pulleys 103 and 103 '. In addition, in this specification, the shape of a band saw and the shape of a base metal are consent.

  The present invention has been made in view of the above-mentioned problems, and is a band saw cutting device that has excellent cutting accuracy when cutting a workpiece such as a silicon crystal and can extend the life of the band saw, and so on. An object of the present invention is to provide a silicon crystal cutting method using a simple band saw cutting device.

In order to achieve the above object, the present invention is a band saw cutting device having a biaxial band saw pulley provided with a resin layer on the outer peripheral surface, and a band saw driven by the band saw pulley.
The band saw pulley has a width of 4 mm to 10 mm, a depth of 3 mm and a depth of 70 mm relative to the thickness of the resin layer in a region including a center position in a width direction of a region where the band saw pulley and the band saw contact. Provided with a band saw cutting device characterized by comprising a groove portion that is not more than%.

  By making the band saw convex outward by the band saw pulley provided with such a groove, the cutting accuracy when cutting silicon crystal or the like is improved, and the life of the band saw can be extended.

  At this time, it is preferable that the band saw pulley is provided with a blade abrasive grain relief step having a width of 6 mm to 10 mm and a depth of 100 μm to 800 μm on the outer peripheral surface.

  By providing the blade abrasive grain relief step having such a shape, the vertical swing of the band saw can be suppressed, and the cutting accuracy and the life of the band saw can be further improved.

  At this time, it is preferable to have a mechanism for tilting the rotation axis of the band saw pulley outward or inward from the vertical direction.

  By providing such a mechanism, it is possible to easily adjust the tip of the blade portion of the band saw and the bottom of the bottom surface of the band saw pulley to coincide with each other. Thereby, the up-and-down swing of the band saw can be suppressed, the life of the band saw can be extended, and the cutting accuracy is further improved.

  At this time, it is preferable that the shape of the band saw during the circular drive is convex outward with respect to the contact surface between the band saw pulley and the band saw.

  Thus, if the shape of the band saw is convex outward, the blade displacement is stable and the straightness of the cutting is improved, so that the cutting accuracy is further improved and the life of the band saw is further prolonged.

In order to achieve the above object, the present invention is a silicon crystal cutting method using a band saw cutting device having a biaxial band saw pulley having a resin layer on the outer peripheral surface and a band saw driven by the band saw pulley. And
A groove part having a width of 4 mm or more and 10 mm or less, a depth of 3 mm or more and a thickness of the resin layer of 70% or less in a region including a center position in a width direction of a region where the band saw pulley contacts the band saw There is provided a method for cutting a silicon crystal, characterized in that the silicon crystal is cut using the band saw pulley formed with.

  By using the band saw pulley provided with such a groove, the band saw has a convex shape to the outside, so that the cutting accuracy when cutting the silicon crystal is improved and the life of the band saw can be extended.

  At this time, it is preferable to cut the silicon crystal by forming a blade abrasive relief step having a width of 6 mm to 10 mm and a depth of 100 μm to 800 μm on the outer peripheral surface of the band saw pulley.

  By forming such a blade abrasive grain relief step, the vertical swing of the band saw can be suppressed, and the cutting accuracy and the life of the band saw can be further improved.

  At this time, the tip of the blade portion of the band saw and the bottom position of the bottom surface of the band saw pulley can be adjusted to coincide with each other by tilting the rotation axis of the band saw pulley outward or inward from the vertical direction. .

  In this way, by adjusting the tip of the band saw blade and the bottom of the bottom of the band saw pulley so as to match, the vertical swing of the band saw is suppressed, and the life of the band saw can be further extended and cut. The accuracy is also improved.

  At this time, depending on the width of the formed groove portion, the shape of the band saw that is cutting the silicon crystal is convex outward with respect to the contact surface between the band saw pulley and the band saw. It is preferable to adjust the tension pressure on the band saw.

  Thus, if the shape of the band saw is adjusted so as to be convex outward, the blade displacement is stabilized and the straightness of cutting is improved, so that the cutting accuracy is further improved and the life of the band saw is also extended.

  As described above, according to the band saw cutting device and the silicon crystal cutting method of the present invention, the band saw is provided with a groove on the outer peripheral surface of the band saw pulley, and the band saw is deformed into a convex shape in the outer peripheral direction, thereby cutting the band saw. The displacement at the time is stabilized, the cutting accuracy is improved, and the life of the band saw can be extended. Furthermore, since the displacement at the time of cutting the band saw is stabilized, a thinner blade can be used than before, and the loss of the sample per cut can be greatly reduced.

It is the schematic which shows an example of the band saw cutting device of this invention. It is a cross-sectional schematic diagram which shows the outer peripheral part of the band saw pulley of the band saw cutting device of this invention. It is a schematic diagram which shows the shape of the band saw of the groove part by this invention. It is a graph which shows the relationship between the shape (width, depth) of a groove part, and an improvement effect. It is the schematic which shows the position of a groove part. It is the schematic which shows a blade abrasive grain escape level | step difference. It is the schematic which shows the band saw pulley inclined outside. It is a schematic diagram which shows adjusting a band saw to convex shape. It is a graph which shows the relationship between the width | variety of a groove part, and tension pressure. It is the schematic which shows an example of the conventional band saw cutting device. It is the schematic which shows the band saw cutting device which has not provided the static pressure pad. It is a figure which shows the shape measurement location of a band saw. It is the schematic which shows the shape (concave shape) of the measured base metal. It is the schematic which shows the shape (convex shape) of the measured base metal. It is a schematic diagram which shows the relationship between a blade sensor and a static pressure pad rear surface. It is a figure which shows the relationship between the frequency | count of cutting of an ingot, and a blade displacement in case a base metal is concave shape. It is a figure which shows the blade displacement in each stage of a life in case a base metal is concave shape. It is a figure which shows the relationship between the frequency | count of cutting of an ingot, and a blade displacement in case a base metal is convex shape. It is a figure which shows the blade displacement in each stage of a life in case a base metal is convex shape. It is a figure which shows the blade displacement in each stage of a life including the case where a base metal changes from a convex shape to a concave shape. It is a schematic diagram which shows the cutting | disconnection direction in case a base metal is concave shape. It is a schematic diagram which shows the cutting | disconnection direction in case a base metal is convex shape. It is the cross-sectional schematic which shows the outer peripheral part of the band saw pulley of the conventional band saw cutting device. It is a schematic diagram which shows the shape of the band saw by a prior art.

  As described above, in a band saw cutting apparatus, an apparatus having a long band saw life and high cutting accuracy is required.

As a result of intensive studies to achieve the above object, the present inventors have found a band saw cutting device having a biaxial band saw pulley having a resin layer on the outer peripheral surface and a band saw driven by the band saw pulley. And
The band saw pulley has a width of 4 mm to 10 mm, a depth of 3 mm and a depth of 70 mm relative to the thickness of the resin layer in a region including a center position in a width direction of a region where the band saw pulley and the band saw contact. The band saw cutting device characterized in that it is provided with a groove portion that is less than or equal to%, the shape of the band saw can be reliably projected outward, and the above-mentioned problems can be solved, and the present invention has been completed. .

  Hereinafter, the present invention will be described in detail as an example of an embodiment with reference to the drawings, but the present invention is not limited thereto.

  First, the band saw cutting device of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic view showing an example of a band saw cutting apparatus according to the present invention. As shown in FIG. 1, the band saw cutting apparatus 1 of the present invention has an endless belt-shaped band saw 2 composed of a blade abrasive grain portion 5 formed by gluing diamond abrasive grains to the end of a thin base metal 6. The band saw pulleys 3 and 3 'having a resin layer on the outer peripheral surface are stretched. The band saw 2 is driven around by the rotation of the band saw pulleys 3 and 3 ′, and the ingot 8 is cut by the blade abrasive grain portion 5 of the band saw 2. In addition, static pressure pads 4, 4 'for guiding the traveling direction of the band saw are provided at the ends of the band saw pulleys 3, 3'. The above is substantially the same as the conventional band saw cutting device. In the band saw pulleys 3 and 3 ′ of the band saw cutting device 1 of the present invention, the width is 4 mm or more and 10 mm or less in the region including the center position in the width direction of the region where the band saw pulleys 3 and 3 ′ and the band saw 2 are in contact with each other. Is provided with grooves 16 and 16 'that are 3 mm or more and 70% or less with respect to the thickness of the resin layer.

  The diameter of the band saw pulleys 3 and 3 ′ can be set to, for example, 500 mm to 700 mm. The band saw pulleys 3 and 3 ′ may be installed in parallel to the floor surface on which the band saw cutting device 1 is installed. The thickness of the base metal 6 of the band saw 2 can be 0.2 mm to 0.5 mm, the width of the band saw 2 can be 50 mm to 80 mm, and the thickness of the blade abrasive grain portion 5 can be 0.50 mm to 1.20 mm.

  The groove part provided in the band saw pulleys 3 and 3 'will be described. FIG. 2 is a cross-sectional view of the outer peripheral portion of the band saw pulley 3 provided with the groove 16 used in the band saw cutting device of the present invention. The band saw pulley 3 includes a resin layer (pulley rubber) 12 on the outer peripheral surface, and a groove portion 16 is formed in the resin layer 12. The groove 16 is provided in a region including the center position in the width direction of a region where the band saw pulley 3 and the band saw 2 are in contact with each other. In addition, as described in Patent Document 1, a plurality of circumferential grooves 20 having a narrower width than the groove portion 16 may be formed in the resin layer 12.

  A description will be given of the fact that the band saw 2 is convex outwardly by the groove 16. FIG. 3 is a schematic diagram showing the shape of the band saw 2 at a portion B (corresponding to a groove) in FIG. 2 when the band saw 2 is driven to rotate using the band saw pulley 3 shown in FIG. In the B portion, the band saw 2 and the band saw pulley 3 do not come into contact with each other, so that the A portion and the C portion serve as fulcrums during rotation, and the B portion rises into a convex shape.

  For comparison, FIG. 23 shows a cross-sectional view of the outer peripheral portion of a general band saw pulley 103 used in a conventional band saw cutting apparatus. As shown in FIG. 23, a resin layer 112 is provided on the outer peripheral portion of the band saw pulley 103, and a plurality of circumferential grooves 120 are provided therein, but the above-described groove portion 16 is not formed. FIG. 24 is a schematic diagram showing the shape of the band saw 102 at the portion B in FIG. 23 when the band saw 102 is driven to rotate using the band saw pulley 103 shown in FIG. Basically, the shape of the band saw 102 in the portion B of FIG. 23 can be a convex shape or a concave shape depending on individual differences of the band saw 102, but when the band saw 102 comes into strong contact with the B portion, it becomes a concave shape.

Here, the relationship between the width and depth of the groove 16 provided in the band saw pulley 3 and the improvement effect such as the life of the band saw 2 and (blade) runout will be described. FIG. 4 is a graph in which the horizontal axis represents the groove depth, the vertical axis represents the groove width, and the conditions where the improvement effect was great are plotted with black circles, and the conditions where the improvement effect was small are plotted with black triangles. The thickness of the resin layer 12 is 7 mm, and 70% of the thickness is about 5 mm. The diameter of the band saw pulley 3 is 700 mm, the material of the resin layer 12 is urethane rubber, the thickness of the base metal 6 is 0.3 mm, and the tension pressure (tension) applied to the band saw 2 is 1.0 t / cm ^2. (Ingot) was cut.

  As shown in FIG. 4, when the width of the groove 16 is 4 mm or more and 10 mm or less and the depth is 3 mm or more and 5 mm or less (corresponding to 70% of the thickness of the resin layer), the life of the band saw 2 is increased and the band saw 2 No particular fluctuation was observed. Specifically, under the conditions in which the black circles in FIG. 4 are plotted, the life of the band saw is improved by 1.8 times or more compared to the conventional band saw cutting apparatus. In addition, the life of the band saw was slightly improved as compared with the conventional band saw cutting apparatus even under the conditions where black triangle marks were plotted in FIG.

  On the other hand, when the width of the groove portion 16 is less than 4 mm, the band saw 2 does not have a convex shape. When the width exceeds 10 mm, the band saw 2 is shaken, and the life of the band saw does not extend much. If the depth of the groove 16 is less than 3 mm, the band saw 2 does not have a convex shape, and if it exceeds 70% of the thickness of the resin layer, the resin layer of the groove 16 becomes too thin and peels from the main body of the band saw pulley. It becomes easy.

  Next, the position of the groove part 16 provided in the band saw pulley 3 will be described. A band saw pulley having a diameter of 700 mm and a width of 80 mm was prepared by changing the position of the groove portion having a width of 5 mm and a depth of 4 mm in three ways. FIG. 5 is a schematic diagram showing the position of the groove 16. The case where the center of the width of the groove 16 is 15 mm below the upper end of the band saw 2 is the D position, the case where it coincides with the center of the width of the band saw 2 is the E position, and the case where it is 15 mm above the lower end of the band saw 2 is the F position. expressed. Further, the band saw 2 having a width of 60 mm was used, and the produced three types of band saw pulleys were rotated by the band saw 2 to evaluate the runout of the blade edge.

  When the band saw pulley having the groove portion formed at the E position was used, the blade edge of the band saw 2 was not shaken at all. On the other hand, when a band saw pulley having grooves at the D position and the F position was used, the vibration of the blade edge of the band saw 2 was confirmed.

  Therefore, a band saw pulley was produced in which the position of the groove 16 having a width of 5 mm and a depth of 4 mm was changed in the vertical direction from the center position of the width of the band saw 2, and the vibration of the blade edge of the band saw 2 was evaluated. As a result, when the center position of the width of the groove portion 16 is within the range of 5 mm vertically (that is, 10 mm width) from the center position of the width of the band saw 2, at least the vibration of the blade edge did not occur. For this reason, in the band saw cutting device 1 of the present invention, the groove 16 needs to be provided at a substantially central position in the width direction of the region where the band saw pulley 3 and the band saw 2 are in contact, and the position of the groove 16 is the band saw pulley and the band saw. It is set as the area | region including the center position of the width direction of the area | region which contacts.

  Moreover, it is preferable that the band saw pulley 3 is provided with a blade abrasive relief step having a width of 6 mm to 10 mm and a depth of 100 μm to 800 μm on the outer peripheral surface. FIG. 6 shows a schematic view of the blade abrasive grain relief step formed on the band saw pulley 3. The blade abrasive relief 18 is generally formed for relief of the cutting edge (abrasive grain). And by setting it as the above-mentioned shape (size), even if it raises and rotates the band saw 2 to a normal driving speed, a shake does not generate | occur | produce up and down. For this reason, the cutting accuracy and the life of the band saw 2 are improved. In addition, if the thickness of the abrasive grain portion is increased, there is no meaning of thinning the blade, and therefore the depth of the blade abrasive grain relief step 18 is preferably 800 μm or less.

  The band saw cutting device 1 may include a mechanism for tilting the rotation axis of the band saw pulleys 3 and 3 ′ from the vertical direction to the outside or the inside. Thus, by providing a mechanism for tilting the rotation axis of the band saw pulleys 3 and 3 ′, the tip of the blade part (blade abrasive grain part 5) of the band saw 2 and the bottom of the bottom surface of the band saw pulleys 3 and 3 ′ are aligned. Adjustments can be made. FIG. 7 is a schematic view showing the band saw pulley tilted outward, which shows this. Adjustment can be performed so that the position of the line connecting the bottoms of the bottom surfaces of the band saw pulleys 3 and 3 ′ shown in the lower diagram of FIG. 7 coincides with the tip of the blade portion of the band saw 2. By adjusting in this way, it is possible to suppress vertical deflection when the band saw is run.

  Further, it is preferable that the shape of the band saw 2 during the circular drive is convex outward with respect to the contact surface between the band saw pulleys 3, 3 ′ and the band saw 2. By providing the band saw pulleys 3 and 3 'with the groove portions as described above, the band saw 2 is formed in a convex shape, and the band saw 2 is floated at a high portion of the convex portion with respect to the rear surface of the static pressure pad. It is more preferable to adjust so. FIG. 8 is a schematic diagram showing that the band saw 2 is adjusted to a convex shape. In FIG. 8, the floating height is preferably 20 to 50 μm with respect to the rear surface 25 of the static pressure pad.

  Next, a silicon crystal cutting method using the band saw cutting apparatus of the present invention will be described with reference to the drawings.

  In the silicon crystal cutting method of the present invention, as shown in FIGS. 1 and 2, in the region including the center position in the width direction of the region where the band saw pulley and the band saw 2 are in contact, the width is 4 mm or more and 10 mm or less, the depth The silicon crystal is cut using the band saw pulleys 3 and 3 ′ in which the groove 16 having a thickness of 3 mm or more and 70% or less with respect to the thickness of the resin layer is formed. By setting it as such a cutting method, the cutting | disconnection precision at the time of cut | disconnecting the silicon crystal 8 improves, and the lifetime of the band saw 2 can be lengthened.

  In addition, the silicon crystal 8 can be cut by forming a blade abrasive relief step 18 having a width of 6 mm or more and 10 mm or less and a depth of 100 μm or more and 800 μm or less on the outer peripheral surface of the band saw pulleys 3 and 3 ′. By forming such a blade abrasive relief 18, the cutting accuracy and the life of the band saw are further improved.

  Further, by tilting the rotation axis of the band saw pulleys 3 and 3 ′ from the vertical direction to the outside or the inside, the tip of the band saw blade part (blade abrasive grain part 5) and the bottom part of the bottom surface of the band saw pulleys 3 and 3 ′ are arranged. The position can be adjusted to match. By adjusting in this way, the vertical swing of the band saw 2 is suppressed, and the cutting accuracy and the life of the band saw are further improved.

  Further, the band saw 2 depends on the width of the groove 16 so that the shape of the band saw 2 cutting the silicon crystal 8 is convex outward with respect to the contact surface between the band saw pulleys 3, 3 ′ and the band saw 2. The tension pressure can be adjusted.

FIG. 9 shows the relationship between the width of the groove 16 of the band saw pulley and the optimum tension pressure of the band saw. As the width of the groove portion 16 increases, the optimum tension pressure also tends to increase. The hatched portion is a region where the convex shape can be formed particularly well, but even if it is not within this range, the width of the groove 16 is 4 mm or more and 10 mm or less, the depth is 3 mm or more, and the thickness of the resin layer If the value is 70% or less, a convex shape can be formed on the band saw 2, and the effect of improving the life of the band saw can be obtained. Further, the tension pressure is preferably 0.8 to 4.0 t / cm ² .

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated more concretely, this invention is not limited to these.

Example 1
Using the band saw cutting apparatus 1 of the present invention described above, a number of silicon ingots having a diameter of about 300 mm manufactured by the CZ method were cut, and the life of the band saw 2 and straight cutting performance were examined. Here, straight cutting performance represents cutting accuracy. The band saw pulleys 3 and 3 ′ had a diameter of 700 mm, a urethane rubber resin layer 12 provided on the outer peripheral portion, and a groove portion 16 having a width of 3 to 11 mm and a depth of 2 to 6 mm. The thickness of the base metal 6 was 0.3 mm. The thickness of the resin layer 12 is 7 mm, 70% of which is about 5 mm. The tension pressure was 1 t / cm ^{2 in} all cases. The results are shown in Table 1 (Conditions 1 to 5) and Table 2 (Conditions 6 to 10). In the following table, the life of the band saw is shown as a relative value, assuming that the life of a conventional band saw cutting device is 1.0.

  In Tables 1 and 2, in the conditions (Conditions 2 to 4 and Conditions 7 to 9) using the band saw cutting device 1 of the present invention, the life of the band saw is 1.8 and the conventional band saw cutting device is used. In addition, the straightness of cutting was good, and no vibration of the band saw 2 was observed. On the other hand, under the conditions 1, 5, and 6 described as reference, the life of the band saw 2 was slightly extended, and the band saw 2 was shaken. In addition, although shake did not occur under the condition 10, there is a concern that the resin layer 12 may be peeled off.

(Example 2)
Next, by changing the shape of the blade abrasive relief 18, a number of about 300 mm diameter silicon ingots manufactured by the CZ method were cut with the band saw cutting device 1 of the present invention, and the life and straightness of cutting of the band saw 2 were investigated. It was. The width of the blade abrasive grain relief step 18 was changed from 5 to 12 mm, and the depth was 200 μm. The diameters of the band saw pulleys 3 and 3 ′ are 700 mm, the outer peripheral portion is provided with a resin layer 12 made of urethane rubber, the width of the groove 16 is 5 mm, and the depth is 4 mm. The thickness of the base metal 6 was 0.3 mm, and the thickness of the resin layer 12 was 7 mm. The results are shown in Table 3 (Conditions 11 to 15).

  In any of the conditions 11 to 15, the band saw cutting device 1 of the present invention using the band saw pulleys 3 and 3 ′ provided with the blade abrasive relief step 18 improved the life of the band saw and the straightness of cutting. In particular, when the width of the blade abrasive grain relief step 18 was 6 mm or more and 10 mm or less (conditions 12, 13, and 14), the life of the band saw was greatly improved to 1.8 and the straightness of cutting was extremely good.

(Example 3)
The silicon crystal 8 was cut using the band saw cutting device 1 having the groove portion of the present invention and the conventional band saw cutting device 101, and the relationship between the uneven shape of the band saw 2, the life of the band saw 2, and the vibration of the band saw 2 was evaluated. The results are shown in Table 4 (Conditions 16 to 22). In Table 4, when the numerical value of the band saw uneven shape column is positive, it indicates a convex shape, and when it is negative, it indicates a concave shape. The numerical value represents the height of the convex portion or the depth of the concave portion.

  As shown in Table 4, when the shape of the band saw 2 during the circular drive is convex outward, the life of the band saw is extended, and the vibration of the band saw is not generated or very little. On the other hand, when the band saw 2 has a concave shape, the life of the band saw has not been extended, and vibration has occurred.

  As described above, by cutting the silicon crystal using the band saw cutting apparatus of the present invention, the life of the band saw and the straightness of cutting can be improved compared to the case of using the conventional band saw cutting apparatus. It was. In addition, the blade displacement is stable, the straightness of cutting is improved, and the cutting accuracy is improved, so that the sample loss at the time of cutting the sample is improved. Furthermore, a thinner blade can be used than before, and the cutting loss of silicon crystal per cut can be reduced by 24% compared to the case of using a conventional band saw that is not a thin blade.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

DESCRIPTION OF SYMBOLS 1 ... Band saw cutting device of this invention, 2 ... Band saw,
3, 3 '... band saw pulley with groove, 4, 4' ... static pressure pad,
5 ... Blade abrasive part, 6 ... Base metal, 8 ... Ingot (silicon crystal),
12 ... Resin layer (pulley rubber) 16, 16 '... Groove,
18 ... blade abrasive relief step, 20 ... circular groove, 25 ... rear surface of hydrostatic pad,
30 ... Blade sensor 101 ... Conventional band saw cutting device,
102 ... Band saw 103, 103 '... Band saw pulley,
104, 104 '... static pressure pad, 105 ... blade abrasive grain part, 106 ... base metal,
108 ... Ingot (silicon crystal) 112 ... Resin layer,
114: Front surface of static pressure pad, 115: Rear surface of static pressure pad, 120 ... Circumferential groove,
L: Distance between the band saw and the blade sensor.

Claims (8)

A band saw cutting device having a biaxial band saw pulley having a resin layer on the outer peripheral surface, and a band saw driven by the band saw pulley,
The band saw pulley has a width of 4 mm to 10 mm, a depth of 3 mm and a depth of 70 mm relative to the thickness of the resin layer in a region including a center position in a width direction of a region where the band saw pulley and the band saw contact. A band saw cutting device comprising a groove portion that is less than or equal to%.   2. The band saw cutting apparatus according to claim 1, wherein the band saw pulley includes a blade abrasive grain relief step having a width of 6 mm to 10 mm and a depth of 100 μm to 800 μm on an outer peripheral surface.   The band saw cutting device according to claim 1 or 2, further comprising a mechanism for tilting a rotation axis of the band saw pulley outward or inward from a vertical direction.   4. The shape of the band saw during circular driving is a convex shape outwardly with respect to the contact surface between the band saw pulley and the band saw. 5. Band saw cutting device. A silicon crystal cutting method by a band saw cutting device having a biaxial band saw pulley having a resin layer on an outer peripheral surface and a band saw driven by the band saw pulley,
A groove part having a width of 4 mm or more and 10 mm or less, a depth of 3 mm or more and a thickness of the resin layer of 70% or less in a region including a center position in a width direction of a region where the band saw pulley contacts the band saw A method for cutting a silicon crystal, wherein the silicon crystal is cut using the band saw pulley formed with.   6. The silicon crystal according to claim 5, wherein a blade abrasive relief step having a width of 6 mm to 10 mm and a depth of 100 μm to 800 μm is formed on the outer peripheral surface of the band saw pulley to cut the silicon crystal. Crystal cutting method.   The tip of the band saw blade and the bottom of the bottom of the band saw pulley are adjusted to coincide with each other by tilting the rotation axis of the band saw pulley outward or inward from the vertical direction. Item 7. The method for cutting a silicon crystal according to Item 5 or Item 6.   Depending on the width of the formed groove, the band saw is shaped to protrude outwardly with respect to the contact surface between the band saw pulley and the band saw while cutting the silicon crystal. The method for cutting a silicon crystal according to any one of claims 5 to 7, wherein a tension pressure is adjusted.

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