JP2005153031A - Wire saw and working fluid feed method of wire saw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire saw, efficiently making a working fluid adhere to a wire to sufficiently feed the fluid to a work piece and a working point, and efficiently cooling the wire and a groove roller to improve the working accuracy of the work piece. <P>SOLUTION: In this wire saw 1, while the working fluid 10 is fed to the reciprocating wire 2, the work piece 8 is vertically pressed to the wire 2 to cut the work piece. The wire saw includes a driving means 20 for periodically moving the wire 2 or the work piece 8 in the vertical direction in cutting the work piece 8, thereby feeding the working fluid 10 to the working point. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wire saw that reciprocates a wire while supplying a machining fluid to cut a workpiece having a high hardness, and a method for supplying a machining fluid for the wire saw.

  For example, a semiconductor wafer is manufactured by thinly cutting a silicon crystal material as a member to be processed, or a wire saw that uses a wire and a processing liquid (slurry) as means for cutting crystal, sapphire, or the like. As shown in FIG. 3, the wire saw 1 of the up-cut method is to slicing the wire 2 fed from a new wire reel (not shown) into three groove rollers 3, 4 and 5 with a predetermined pitch (to be sliced). The workpiece (hereinafter referred to as “workpiece”) 8 wound around each groove with a thickness of (plate thickness + cutting allowance) and placed and fixed on a table 7 disposed below the plurality of rows of wires 2 is pressed from below the wires 2. The table 7 is moved upward, and the groove roller 3 is driven by the drive motor 6 so that each wire 2 is horizontally aligned in a linear direction indicated by an arrow so that a predetermined wire speed (reciprocating speed) + wire feed (new line feed amount) is obtained. As shown in FIG. 4, the machining liquid 10 is supplied to each wire 2 from the machining liquid supply device 9 disposed above the workpiece 8 as shown in FIG. 4, and the abrasive grains dispersed in the machining liquid 10 by the wire 2 are supplied. Wrapping action Cause, and performs the cutting of the workpiece 8 by the wrapping action. The wire 2 exiting the roller 5 is wound up on a take-up reel (not shown) (see, for example, Patent Document 1).

The machining liquid supply device 9 includes a nozzle 11 that supplies the machining liquid 10, a tank 12 that stores the machining liquid 10 supplied from the nozzle 11, and a filter 13 that is provided at the left and right corners of the bottom surface of the tank 12. The machining liquid 10 in the tank 12 is made to flow down in a curtain shape as indicated by arrows from the left and right filters 13 and is supplied to both sides of the workpiece 8 of each wire 2.
Japanese Patent No. 2656719 (FIG. 1)

  However, in the wire saw having the above-described configuration, the reciprocating wire 2 only crosses the machining liquid 10 flowing down in a curtain shape, so that the machining liquid 10 cannot be efficiently attached to the wire 2. Most of the machining fluid 10 adhered to the workpiece 8 and carried to the workpiece 8 falls on the surface of the workpiece 8 because the gap between the wire 2 and the workpiece 8 is narrow, and the amount of the machining fluid 10 brought into the machining point becomes small. 10 cannot be sufficiently supplied to the processing point. For this reason, the sharpness of the wire 2 is poor and the processing accuracy is poor. Further, the heat generated by the cutting (hereinafter referred to as “processing heat”) heats the groove rollers 4 and 5 via the wire 2, and the heat expansion of these groove rollers 4 and 5 causes warping of the workpiece 8 in the processing direction. There is a problem that waviness increases and machining accuracy deteriorates.

  The present invention has been made in view of the above-described points. The machining liquid is efficiently attached to the wire so that it can be sufficiently supplied to the machining point with the workpiece, and the wire and the groove roller are efficiently cooled. It is an object of the present invention to provide a wire saw and a processing fluid supply method for the wire saw that can improve the processing accuracy of a workpiece.

In order to achieve the above object, according to the first aspect of the present invention, in a wire saw for cutting a workpiece by pressing the workpiece in a direction perpendicular to the wire while supplying a machining fluid to the reciprocating wire, A driving means for periodically moving the wire or the workpiece in the vertical direction is provided.
According to a second aspect of the present invention, in the wire saw according to the first aspect, the wire saw further comprises control means for changing a reciprocating speed of the wire in accordance with a cutting position of the workpiece.

According to a third aspect of the present invention, in the wire saw according to the first aspect, the wire saw according to the first aspect further comprises control means for changing a tension of the wire in accordance with a cutting position of the workpiece.
According to a fourth aspect of the present invention, in the wire saw according to any one of the first to third aspects, a working fluid receiving plate is provided along the wire to the vicinity of both sides of the workpiece under the wire, and the working fluid receiving plate is provided with the working fluid receiving plate. It is characterized in that a machining fluid is supplied and brought into contact with the wire.

  According to a fifth aspect of the present invention, in a wire saw machining fluid supply method for cutting a workpiece by pressing the workpiece in a direction perpendicular to the wire while supplying the machining fluid to a reciprocating wire, the wire or workpiece is cut when the workpiece is cut. A workpiece is periodically moved in the vertical direction to form a gap between the wire and the workpiece, and the machining liquid is fed into the gap.

  According to the first aspect of the present invention, it is possible to open a gap between the wire and the workpiece by periodically moving the wire or the workpiece in a direction perpendicular to the wire, and the wire or the workpiece is attached to the wire. The machining fluid can be drawn in, and the machining fluid can be supplied to the machining point of the wire. Thereby, it becomes possible to improve the machining capability of the workpiece, improve the machining accuracy, and the like.

According to the invention of claim 2, by changing the reciprocating speed of the wire in accordance with the cutting position of the workpiece, the processing start position of the workpiece can be accurately positioned. The processing accuracy is improved.
In the invention of claim 3, by changing the tension of the wire according to the cutting position of the workpiece, it becomes possible to suppress an increase in processing capability, warpage and undulation in the processing direction of the workpiece, Processing accuracy can be improved.

  In the invention of claim 4, the working fluid can be sufficiently supplied between the wire and the workpiece, thereby increasing the pressing force between the wire and the workpiece and increasing the machining capability. In addition, the processing speed increases, the sharpness improves, and the processing accuracy improves. In addition, since the machining fluid can be sufficiently adhered to the wire, the machining fluid adhered to the wire can be supplied to the groove roller that reciprocates the wire, and thermal expansion of the wire and the groove roller due to machining heat is suppressed. As a result, warpage and undulation in the machining direction are reduced, and machining accuracy is improved.

  In the invention of claim 5, when the workpiece is cut, the machining liquid can be sufficiently supplied to the gap between the wire and the workpiece, thereby increasing the pressing force between the wire and the workpiece. The processing capability increases, the processing speed increases, the sharpness improves, and the processing accuracy improves. Further, the machining fluid can be sufficiently adhered to the wire, and the machining fluid adhered to the wire can be supplied to the groove roller for reciprocating the wire, and the wire and the groove roller are thermally expanded by machining heat. Is suppressed, warping and undulation in the machining direction are reduced, and machining accuracy is improved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a schematic configuration of a wire saw according to the present invention. The same members as those shown in FIGS. 3 and 4 are denoted by the same reference numerals. The wire saw 1 winds a wire 2 fed from a new wire reel (not shown) around each groove at a predetermined pitch (plate thickness to be sliced + cutting allowance) around three groove rollers 3, 4 and 5. The table 7 is moved up and down while pressing the work 8 placed and fixed on the table 7 arranged below the plurality of rows of wires 2 from below the wire 2, and the groove roller 3 is driven by a drive motor to obtain a predetermined wire speed. Each wire 2 is horizontally reciprocated in the linear direction indicated by arrows A and B so that (reciprocating speed) + wire feed (new line feed amount), and from the machining fluid supply device 9 disposed above the workpiece 8 The machining liquid 10 is supplied to each wire 2, and a lapping action of abrasive grains dispersed in the machining liquid 10 is generated by the wire 2, and the workpiece 8 is cut by this lapping action. Further, tension adjusting means (not shown) is provided on the feeding side of the wire 2 so that the tension of the wire 2 can be adjusted to a predetermined value.

  The processing liquid supply device 9 includes a nozzle 11 that supplies the processing liquid 10, a tank 12 that stores the processing liquid 10 supplied from the nozzle 11, and filters 13 and 13 that are provided at the left and right corners of the bottom surface of the tank 12. Thus, the machining liquid 10 in the tank 12 flows down in a curtain shape from these left and right filters 13 and 13 and is supplied to both sides of the workpiece 8 of each wire 2.

  Work fluid receiving plates 15 and 15 are provided on the left and right sides of the workpiece 8 with a slight gap (1 to 8 mm) below the plurality of rows of wires 2. These left and right machining fluid receiving plates 15 and 15 have substantially the same length (width) as the length of the groove rollers 4 and 5 (perpendicular to the paper surface). Are disposed horizontally along the wire 2 up to a position near both side portions of the base plate, and both side portions on the base end side are fixed to the support plate 16 via brackets (not shown), and the support plate 16 is not shown. It is fixed to the frame. A sufficient gap is provided between the upper surface of the working fluid receiving plate 15 and the lower end of the support plate 16, and the wire 2 is allowed to reciprocate freely. The working fluid receiving plate 15 may be a wide flat plate, or may be formed into a bowl shape by bending both side portions parallel to the wire 2 upward.

  Under the support plate 16, a guide plate 17 is provided below the filters 13 and 13 of the machining liquid supply device 9 and above the wire 2. The upper end of the guide plate 17 is fixed to the lower portion of the support plate 16 and extends obliquely downward to the workpiece 8 side to near the center of the machining liquid receiving plate 15, and the tip is slightly above the wire 2 (1 to 1). 5mm) apart. The guide plate 17 guides and supplies the machining liquid flowing down from the filter 13 in a curtain shape to the upper surface of the machining liquid receiving plate 15.

  The table 7 can be vertically moved (moved up and down) vertically as indicated by arrows C and D by the driving means 20. A feed nut 21 is arranged and fixed on the base 7a of the table 7 with the axial direction being vertical (vertical direction), and a feed screw 22 is vertically screwed to the feed nut 21. A gear 23 is fixed to the proximal end of the feed screw 22, and meshes with a gear 25 fixed to the shaft of the drive motor 26 via a timing belt 24. The drive motor 26 drives the feed screw 22 through the gears 25 to 23 to move the table 7 upward (upward) or downward (downward) to press the wire 2 against the workpiece 8 when the workpiece 8 is cut. A gap is formed between the wire 2 and the workpiece 8.

  The control device 28 includes a computer, and according to a predetermined program, a cycle for opening a gap between the wire 2 and the workpiece 8 according to a cutting position (processing position) of the workpiece 8, a gap interval, a workpiece, that is, the table 7. The drive motor 26 is controlled to control the speed (table speed) for lowering or raising the speed. Further, the control device 28 controls the motor 6 to control the speed of the wire 2 (reciprocating speed), the wire feed (new line feed amount), and the like. The cycle of opening the gap between the wire 2 and the workpiece 8, the gap interval, the table speed, and the like are controlled to optimum values according to the shape, material, and the like of the workpiece 8.

The operation will be described below.
As shown in FIG. 2, when the workpiece 8 is cut, the machining liquid 10 is supplied from the nozzle 11 to the tank 12, and the machining liquid 10 flows down from the left and right filters 13, 13 in a curtain shape as indicated by arrows, and guides The plate 17 is supplied onto the machining liquid receiving plate 15 and flows on the machining liquid receiving plate 15 in the longitudinal direction (left-right direction). The wire 2 reciprocates horizontally in the left-right direction indicated by the arrow A or B in the machining liquid 10 supplied onto the machining liquid receiving plate 15. Therefore, the processing liquid 10 adheres to the surface of the wire 2 over substantially the entire length of the processing liquid receiving plate 15. Note that the wire 2 can sufficiently supply the machining liquid to the machining point even if the lower portion of the wire 2 comes into contact with the machining liquid 10 on the machining receiving plate 15.

  The control device 28 drives the drive motor 26 when the wire 2 moves to the right indicated by the arrow A, and slightly lowers the table 7 to open a gap between the wire 2 and the processing point. Most of the machining liquid adhering to both sides of the machining liquid 10 adhering to the surface of the wire 2 is scraped off by the surface of the work 8 and drops because the gap between the wire 2 and the work 8 is small. The machining liquid adhering to the lower side of the wire 2 is drawn in a large amount from the left into the gap between the wire 2 and the machining point of the workpiece 8 as shown in the figure. As a result, a sufficient amount of machining fluid is supplied to the machining points of the wire 2 and the workpiece 8. At the same time, chips are efficiently discharged from the processing point to the right.

  Next, the control device 28 raises the table 27 and moves the wire 2 to the left as shown by the arrow B while pressing the machining point of the workpiece 8 against the wire 2, and the workpiece 8 is moved by the large amount of machining fluid supplied. Disconnect. The control device 28 lowers or raises the cycle of opening the gap between the wire 2 and the workpiece 8 according to the cutting position (machining position) of the workpiece 8 based on the control program, the gap interval, the workpiece 8, that is, the table 7. The speed to be pressed (table speed), the time for pressing the workpiece 8 against the wire 2, and the like are controlled to optimum values. Thereby, the force which presses the workpiece | work 8 to the wire 2 can be increased, processing capability increases, a processing speed becomes high, sharpness improves, and processing precision improves.

  When the reciprocating wire 2 moves in the direction of arrow A, the machining fluid 10 on the left machining fluid receiving plate 15 is conveyed in the direction of the workpiece 8 as described above, but on the right machining fluid receiving plate 15. The machining liquid 10 adheres to the wire 2 and is carried in the direction of the groove roller 5 to cool the wire 2 and the groove roller 5 efficiently. On the contrary, when the wire 2 moves in the direction of arrow B, the wire 2 and the groove roller 4 are cooled efficiently in the same manner. Thereby, the thermal expansion of the groove rollers 4 and 5 due to the processing heat is suppressed, the warp and the undulation in the processing direction of the workpiece 8 are reduced, and the processing accuracy is improved.

As described above, it is possible to increase the table speed because sufficient machining fluid can be supplied to the machining point of the wire 2 with the workpiece 8 by raising and lowering the workpiece periodically (periodically). It is possible to shorten the total machining time required from the machining start to the machining end and improve the machining accuracy of the workpiece 8.
Note that the table 7 is lowered to create a gap between the wire 2 and the workpiece 8, and the machining fluid 10 that flows down the wire 2 in a curtain shape as shown in FIG. Even in this case, it is possible to supply the machining liquid 10 adhered to the lower side of the wire 2 to the machining point. However, by providing the machining fluid receiving plate 15 as described above, a large amount of machining fluid can be attached around the wire 2 and a sufficient amount of machining fluid can be supplied to the machining point. . Thereby, each effect mentioned above can be acquired.

  In the above-described embodiment, the case where the table speed is changed in accordance with the workpiece processing position (cutting position) has been described. However, the drive motor 6 (see FIG. The wire reciprocating speed may be changed by controlling 3). In this case, the processing position of the workpiece 8 can be accurately positioned by slowing down the speed of the wire 2 at the start (start) of the processing of the workpiece 8, and the processing accuracy of the workpiece 8 is also improved accordingly.

  Alternatively, the tension of the wire 2 may be changed according to the processing position of the workpiece 8 by the control device 28. In this case, by increasing the tension of the wire 2 at the start of machining, the wire 2 becomes difficult to bend even if the distance from the groove rollers 4 and 5 to the workpiece 8 is long, and the machining capability increases and the workpiece 8 warps in the machining direction. It becomes possible to suppress waviness and undulation, and the machining accuracy can be improved.

In the above embodiment, the case where the machining fluid is supplied from above the wire has been described. However, the present invention is not limited to this. Even when the machining fluid is supplied below or from the side of the wire, the machining fluid is received below the wire. A similar effect can be obtained by providing a plate.
In the above-described embodiment, the up-cut type wire saw that lifts the workpiece 8 from below the wire 2 that reciprocates horizontally and presses the workpiece 8 against the wire 2 for cutting is described. However, the table 7 is placed above the wire 2. With regard to a down-saw type wire saw in which the workpiece 8 is lowered and pressed against the wire 2 for cutting, the working fluid is applied to the upper portion of the wire 2 by adjusting the distance between the working fluid receiving plate 15 and the wire 2. As described above, the table 7 is periodically lifted to open a gap between the upper portion of the wire 2 and the workpiece 8, and a sufficient amount of machining liquid is supplied to the machining point by feeding the machining liquid into the gap. The same effect as in the case of a round-up wire saw can be obtained.

  Further, in the above-described embodiment, the case has been described in which the height position of the wire 2 is fixed and the table 7 is periodically moved up and down (lifted) to open a gap between the wire 2 and the workpiece 8. The same effect can be obtained even if the height position of 7 is kept constant and the wire 2 is periodically moved up and down (lifted).

It is principal part sectional drawing of the wire saw which concerns on this invention. It is explanatory drawing of the supply operation | movement of the process liquid at the time of a process of the wire saw shown in FIG. It is a principal part perspective view which shows an example of a structure of a wire saw. It is explanatory drawing of the processing liquid supply apparatus of the conventional wire saw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wire saw 2 Wire 3, 4, 5 Groove roller 6 Drive motor 7 Table 8 Work 9 Processing liquid supply apparatus 20 Drive means 21 Feed nut 22 Feed screw 23, 25 Gear 24 Timing belt 26 Drive motor 28 Control apparatus

Claims (5)

In a wire saw that cuts a workpiece by pressing the workpiece in a direction perpendicular to the wire while supplying a working fluid to the reciprocating wire,
A wire saw comprising driving means for periodically moving the wire or the workpiece in the vertical direction when the workpiece is cut.   2. The wire saw according to claim 1, further comprising control means for changing a reciprocating speed of the wire in accordance with a cutting position of the workpiece.   2. The wire saw according to claim 1, further comprising control means for changing a tension of the wire in accordance with a cutting position of the workpiece.   The processing liquid receiving plate is provided along the wire to the vicinity of both sides of the workpiece under the wire, and the processing liquid is supplied to the processing liquid receiving plate to be brought into contact with the wire. The wire saw according to 1 to 3. In a wire saw machining fluid supply method of cutting a workpiece by pressing the workpiece in a direction perpendicular to the wire while supplying the machining fluid to a reciprocating wire,
The wire or the workpiece is periodically moved in the vertical direction when the workpiece is cut to open a gap between the wire and the workpiece, and the machining liquid is fed into the gap. Wire saw machining fluid supply method.

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