JP6850569B2 - Polishing method - Google Patents

Description

The present invention relates to a polishing method in which an annular polishing grindstone is rotated to polish a rectangular side surface of a work piece.

As the chip to be the test piece, for example, an Altic (alumina / titanium / carbide composite ceramics) substrate formed in a wafer shape is cut and divided into predetermined dimensions. Since the hardness of such an altic substrate is as high as about 2000 in Vickers hardness, it is cut into chips having a predetermined size by a cutting blade in which diamond abrasive grains are hardened with a bonding agent. When the cut chip is used as a test piece, it may be required that the surface roughness of the side surface formed by the cutting process be set to a surface accuracy of several tens of nm or less. In order to realize such surface accuracy, for example, as disclosed in Patent Document 1, a processing method of polishing a side surface to be a cut surface using a tip as a workpiece has been proposed.

In the processing method of Patent Document 1, an annular polishing wheel rotatably mounted on the spindle is used. In Patent Document 1, the polished surface of the rotating polishing wheel is made to act on the side surface of the chip for polishing. In this polishing, the relative movement direction between the polishing wheel and the chip is set to be the width direction of the chip, in other words, the direction orthogonal to the thickness direction of the side forming edges of the chip.

Japanese Unexamined Patent Publication No. 2001-277110

However, the processing method of Patent Document 1 has a problem that when the width direction dimension of the chip is large, the relative movement amount between the polishing wheel and the chip during polishing is also large, and the time for polishing the side surface of the chip is long. It was.

The present invention has been made in view of such a point, and an object of the present invention is to provide a polishing method capable of efficiently polishing a rectangular side surface of a work piece.

The polishing method of the present invention includes a holding means having a horizontal holding surface for holding an object to be worked, a processing means having a spindle at the tip of which rotatably mounts a processing tool on a rotation axis parallel to the holding surface. A work piece held on the holding surface of the holding means by mounting a polishing tool on the spindle using a processing device including a moving means for moving the holding means and the processing means in a direction of relatively approaching and separating. A polishing method for polishing a rectangular side surface of a rectangular shape. The workpiece is held on the holding surface of the holding means with the rectangular side surface protruding from the outer peripheral edge of the holding means, and the polishing tool is held around a rotation axis. A polishing grindstone having an annular polishing surface on the circumference of the workpiece is provided, and the annular polishing grindstone is formed with an inner diameter that accommodates the entire rectangular side surface of the workpiece, and the polishing tool is the lower surface of the workpiece. Is held on the holding surface, and the center of rotation is accommodated in the inner diameter of the polishing grindstone in the direction perpendicular to the holding surface of the holding means and from the upper side of the rectangular side surface of the workpiece to the entire rectangular side surface. It is characterized by moving relative to the position and polishing the rectangular side surface.

According to this configuration, polishing is performed so that the entire rectangular side surface of the work piece is accommodated inside the annular polishing grindstone, so that the work piece is perpendicular to the holding surface of the holding means in the thickness direction of the work piece. The polishing tool can be moved relative to polish the rectangular side surface. As a result, the relative movement amount can be reduced and the polishing time can be shortened as compared with the conventional case where the work piece is relatively moved in the width direction of the rectangular side surface for polishing.

According to the present invention, since the polishing tool can be relatively moved in the thickness direction of the workpiece to polish the rectangular side surface of the workpiece, the rectangular side surface can be efficiently polished in a short time.

It is a schematic perspective view of the processing apparatus which concerns on this embodiment. It is a schematic perspective view of the main part of a processing apparatus. It is a schematic perspective view of the main part of a holding means. It is a schematic perspective view which shows the state which the compound tool is attached to the spindle. It is explanatory drawing which shows the cutting process of this embodiment. It is explanatory drawing which shows the polishing process of this embodiment. It is explanatory drawing which shows the polishing process of this embodiment. It is explanatory drawing which shows the polishing method in the comparative example. It is explanatory drawing which shows the polishing process of the modification.

Hereinafter, the processing apparatus used in the polishing method of the present embodiment will be described with reference to the attached drawings. FIG. 1 is a schematic perspective view of a processing apparatus according to the present embodiment. FIG. 2 is a schematic perspective view of a main part of the processing apparatus according to the present embodiment. The processing apparatus according to the present embodiment is not limited to the configuration shown in FIGS. 1 to 4. The configuration of the processing apparatus may be changed as long as the side surface of the workpiece can be polished as described later.

As shown in FIG. 1, the machining apparatus 10 is configured to machine a workpiece held on a chuck table 31 by mounting a composite tool 52 having both a cutting tool and a polishing tool as a machining tool. There is. Here, examples of the workpiece include a rectangular workpiece W1 formed in a wafer shape and having a Vickers hardness of approximately 2000, and a rectangular workpiece W2 formed from the altic disk substrate W1. A plurality of cutting lines (not shown) are formed on the Altic disk substrate W1. The processing apparatus 10 cuts the Altic disk substrate W1 mounted on the frame F by the tape T along the cutting line to form a rectangular work W2 having a rectangular shape, and polishes the side surface of the rectangular work W2.

The processing device 10 includes a substantially rectangular parallelepiped housing 11. The housing 11 is provided with a base 2, a chuck table 31, a chuck table moving mechanism 4, a processing means 5, and a processing means moving mechanism (moving means) 6 shown in FIG.

The chuck table 31 constitutes the holding means 3, and a suction surface 311 is horizontally formed on the upper surface of the chuck table 31 by a porous ceramic material. The suction surface 311 is connected to a suction source (not shown) through a flow path in the chuck table 31, and the Altic disk substrate W1 is sucked and held by the negative pressure generated on the suction surface 311.

FIG. 3 is a schematic perspective view of a main part of the holding means. As shown in FIG. 3, the holding means 3 further includes a removable workpiece holding portion 32 (not shown in FIGS. 1 and 2) on the chuck table 31. The workpiece holding portion 32 includes a substrate 321 and a first fixing member 322 and a second fixing member 323 arranged on the substrate 321. The substrate 321 is mounted on the chuck table 31 via suction holding or a fixing means (not shown). The shape of the substrate 321 is not particularly limited, and may be rectangular or may be formed in a circular shape to have the same shape as the chuck table 31.

The first fixing member 322 is formed in a rectangular parallelepiped shape, and has a horizontal holding surface 322a on its upper surface for sucking and holding the lower surface of the rectangular work W2. The holding surface 322a is provided with a suction port (not shown) so as to open, and this suction port is connected to the suction surface 311 or a suction means (not shown), and the rectangular work W2 is sucked and held by the negative pressure generated on the holding surface 322a. Rectangle.

The second fixing member 323 is formed in a rectangular parallelepiped shape, and is provided so as to be movable relative to the first fixing member 322 via a moving means including an air cylinder or the like (not shown). The second fixing member 323 has a holding surface 323a on the side surface that sucks and holds the side surface of the rectangular work W2 that is sucked and held by the first fixing member 322 in a state where the second fixing member 323 is arranged side by side with the first fixing member 322. .. A suction port (not shown) is provided on the holding surface 323a so as to open, and this suction port is also connected to the suction surface 311 or a suction means (not shown), and the rectangular work W2 is sucked and held by the negative pressure generated on the holding surface 323a. To.

Returning to FIG. 2, the chuck table moving mechanism 4 is provided on the base 2 and moves the chuck table 31 in the X direction. The chuck table moving mechanism 4 has a pair of guide rails 41 arranged on the base 2 parallel to the X direction and a motor-driven X-axis table 42 slidably installed on the pair of guide rails 41. ing. A chuck table 31 is rotatably provided on the upper part of the X-axis table 42 via a θ table 43. A nut portion (not shown) is formed on the back side of the X-axis table 42, and a ball screw 44 is screwed into the nut portion. Then, the drive motor 45 connected to one end of the ball screw 44 is rotationally driven, so that the chuck table 31 is moved in the X direction along the guide rail 41.

The processing means 5 is configured by mounting the composite tool 52 on the tip of the spindle 51. The spindle 51 is rotationally driven by a rotation drive mechanism (not shown) in the spindle housing 53 extending in the Y direction to rotate the composite tool 52. The center of rotation of the spindle 51 is oriented in the Y direction and is parallel to the above-mentioned horizontal holding surface 322a (see FIG. 3).

Next, the composite tool 52 will be described with reference to FIG. FIG. 4 is a perspective view showing a state in which the compound tool is mounted on the spindle. The compound tool 52 includes a cylindrical base (hub) 521, an annular cutting blade 522 provided on the outer peripheral portion of one side surface of the base 521, and an annular polishing wheel provided on the other side surface of the base 521. Polishing tool) 523. In the composite tool 52 configured in this way, the base 521 is fitted to the mounter 54 attached to the spindle 51, and the tightening nut 55 is screwed into the screw formed on the outer peripheral surface of the end portion of the mounter 54. Is attached to the spindle 51. As the cutting blade 522, for example, an electroformed blade in which diamond abrasive grains are hardened with an electroformed bond to form a circle is selected.

The polishing wheel 523 includes a large number of grinding wheels 524 arranged in an annular shape, and as the grinding wheel 524, for example, a resin bond grindstone in which diamond abrasive grains are bonded by a resin bond or the like is used. The grinding wheel 524 has an annular polishing surface 524a on the circumference centered on the rotation axis of the spindle 51 on the tip end side thereof. Here, as shown in FIG. 7, the inner diameter dimension D of the annular polishing wheel 524 is formed to be larger than the width of the rectangular side surface W2a of the rectangular work W2 to be the workpiece. Therefore, the polishing wheel 524 is formed to have an inner diameter that accommodates the entire surface of the rectangular side surface W2a.

Returning to FIG. 2, the processing means moving mechanism 6 is provided on the base 2 and moves the processing means 5 in the Y direction and the Z direction above the chuck table 31, and the chuck table 31 and the processing means 5 are relative to each other. Move in the direction of approaching and separating from. The processing means moving mechanism 6 has a pair of guide rails 61 arranged on the base 2 parallel to the Y direction and a motor-driven Y-axis table 62 slidably installed on the pair of guide rails 61. ing. The Y-axis table 62 is formed in a rectangular shape when viewed from above, and a side wall portion 63 is erected on the upper surface of the Y-axis table 62.

Further, the cutting means moving mechanism 6 has a pair of guide rails 64 (only one is shown) parallel to the Z direction installed on the wall surface of the side wall portion 63 and a Z axis slidably installed on the pair of guide rails 64. It has a table 65. Nut portions (not shown) are formed on the back side of the Y-axis table 62 and the Z-axis table 65, respectively, and ball screws 66 and 67 are screwed into these nut portions. Then, the drive motors 68, 69 connected to one end of the ball screws 66, 67 are rotationally driven, so that the processing means 5 is moved in the Y direction and the Z direction along the guide rails 61, 64.

Returning to FIG. 1, when cutting the altic disk substrate W1, the processing apparatus 10 has a cassette 12 for stocking the altic disk substrate W1, a workpiece carrying out means 13, a workpiece transporting means 14, and a cleaning means 15. The cleaning and transporting means 16 and the alignment means 17 including a microscope, a CCD camera, and the like are provided. The Altic disk substrate W1 is housed in the cassette 12 while being mounted on the frame F. Further, the cassette 12 is placed on a cassette table 121 arranged so as to be movable up and down by an elevating means (not shown).

Next, a machining processing operation for cutting from the Altic disk substrate W1 into the rectangular workpiece W2 by the machining apparatus 10 in the present embodiment will be described. Here, the Altic disk substrate W1 mounted on the frame F (hereinafter, the Altic disk substrate W1 mounted on the frame F is simply referred to as the Altic disk substrate W1) is housed in a predetermined position of the cassette 12. The accommodated Altic disk substrate W1 is conveyed onto the chuck table 31 via the workpiece unloading means 13 and the workpiece conveying means 14, and is sucked and held. After that, the chuck table 31 is positioned directly under the alignment means 17, and the alignment means 17 detects and aligns the cutting line formed on the Altic disk substrate W1.

After such alignment, the cutting blade 522 of the composite tool 52 is moved and adjusted in the Y direction, which is the indexing direction, and the Z direction, which is the cutting direction, and is positioned, and the composite tool 52 is rotationally driven. In this state, the chuck table 31 is moved in the X direction, which is the cutting feed direction, and the altic disk substrate W1 held by the chuck table 31 is cut along a predetermined cutting line by the cutting blade 522 of the composite tool 52. Each time cutting along the cutting line as described above, the composite tool 52 indexes and feeds in the Y direction to repeat the cutting, and when all the cutting lines extending in the X direction are cut by the Altic disk substrate W1, the chuck table is used. 31 is rotated 90 °. After this rotation, cutting is performed in the same manner as described above along each cutting line extending in the X direction, and a plurality of rectangular workpieces W2 (see FIG. 3) are divided and formed from the Altic disk substrate W1. The divided rectangular work W2 does not fall apart due to the action of the tape T, and the state of the artic disk substrate W1 mounted on the frame F is maintained.

After the cutting of the Altic disk substrate W1 is completed, the Altic disk substrate W1 is conveyed to the cleaning means 15 by the cleaning and conveying means 16 for cleaning. Then, after cleaning, the artic disk substrate W1 is conveyed via the workpiece unloading means 13 and the workpiece conveying means 14, and is stored in a predetermined position of the cassette 12. After that, the rectangular work W2 is obtained by peeling off the rectangular work W2 from the tape T attached to the frame F.

Subsequently, a polishing method for polishing the rectangular side surface W2a (see FIG. 5) having a rectangular shape in the rectangular work W2 by the processing apparatus 10 in the present embodiment will be described.

First, as shown in FIG. 3, a holding step of holding the rectangular work W2 by the holding means 3 is performed. In this holding step, the substrate 321 of the workpiece holding portion 32 is mounted on the chuck table 31. By this mounting, the suction surface 311 of the chuck table 31 and the holding surface 322a of the first fixing member 322 and the holding surface 323a of the second fixing member 323 communicate with each other so that negative pressure is generated on each holding surface 322a and 323a. Become. Subsequently, the lower surface of the rectangular work W2 is placed on the holding surface 322a of the first fixing member 322 and is attracted and held, while the left side surface of the rectangular work W2 in FIG. 3 contacts the holding surface 323a of the second fixing member 323. And is adsorbed and held. At this time, the rectangular work W2 protrudes to the left side in FIG. 3 and is held from the outer peripheral edge of the first fixing member 322.

FIG. 5 is an explanatory diagram of a cutting process in the present embodiment. As shown in FIG. 5, a cutting step is performed after the holding step. In the cutting step, the cutting blade 522 of the composite tool 52 is moved and adjusted in the Y direction and the Z direction to be positioned at the cutting position of the rectangular work W2, and the composite tool 52 is rotationally driven. In this state, the rectangular work W2 held on the chuck table 31 via the fixing members 322 and 323 is moved in the X direction. As a result, the portion of the rectangular work W2 held by the fixing members 322 and 323 that protrudes from the outer edge of the first fixing member 322 is cut by the cutting blade 522 of the composite tool 52.

In this cutting, the cutting surface of the cutting blade 522 located on the right side in FIG. 5 is formed as a rectangular side surface W2a having a rectangular shape. Further, the portion of the rectangular work W2 separated to the second fixing member 323 side by cutting in the cutting step becomes a rod-shaped portion W3, and the rod-shaped portion W3 is attracted to the second fixing member 323 together with the second fixing member 323. It moves to a position away from the first fixing member 322 and is retracted.

6 and 7 are explanatory views of the polishing process in the present embodiment. As shown in FIG. 6, in the polishing step performed after the cutting step, the composite tool 52 is positioned in the Z direction so as to be located above the rectangular work W2. Further, in the Y direction, the rectangular work W2 is moved and positioned so that the polishing surface 524a of the polishing wheel 524 acts on the rectangular side surface W2a of the rectangular work W2. Further, as shown in FIG. 7, in the X direction, the center position O1 of the annular polishing wheel 523 is positioned so that the center position O2 of the rectangular side surface W2a of the rectangular work W2 in the width direction (X direction) coincides with the center position O1. ..

In this position, the compound tool 52 is lowered in the direction perpendicular to the holding surface 322a of the first fixing member 322 (Z direction), and the polishing wheel 524 is moved relative to the rectangular work W2. Then, the polishing wheel 524 is moved from the upper side of the rectangular side surface W2a of the rectangular work W2 to a position where the entire surface of the rectangular side surface W2a is accommodated in the inner diameter of the polishing wheel 524 indicated by the alternate long and short dash line in FIG. During this movement, the rectangular side surface W2a passes through the rotating polishing surface 524a while being in contact with the rotating polishing surface 524a to be polished. By this polishing, the surface roughness of the rectangular side surface W2a becomes a predetermined accuracy, and the lowering of the compound tool 52 is stopped in a state where the entire surface of the rectangular side surface W2a is contained inside the polishing grindstone 524.

After polishing in this way, the polishing wheel 524 is moved in the Y direction so as to be separated from the rectangular work W2, and then the polishing wheel 523 is moved upward, and then the suction by the first fixing member 322 is released to release the rectangular work. W2 will be obtained.

In the polishing step of the present embodiment, the movement amount of the polishing grindstone 524 from immediately before polishing the rectangular side surface W2a to immediately after the completion of polishing is the movement amount L1 shown in FIG. 7, which is smaller than the inner peripheral radius of the polishing grindstone 524. Here, in order to compare and explain the movement amount L1 of the present embodiment, the polishing method shown in FIG. 8 will be examined as a comparative example.

FIG. 8 is an explanatory diagram of the polishing method in the comparative example. In FIG. 8, the same reference numerals are given to the same configurations as those in the above embodiment for convenience. In the comparative example, the moving direction of the polishing grindstone 524 when polishing the rectangular side surface W2a is changed with respect to the above embodiment. The moving direction of the polishing grindstone 524 in the comparative example is set to the width direction of the rectangular side surface W2a, in other words, the direction (X direction) in which the side orthogonal to the thickness direction extends on the rectangular side surface W2a. Further, at the time of polishing, the position of the polishing wheel 524 in the Z direction is set to a position where the lowermost portion of the inner circumference of the polishing wheel 524 is slightly higher than the lower surface of the rectangular side surface W2a. At this time, the movement amount of the polishing grindstone 524 from immediately before polishing the rectangular side surface W2a to immediately after the completion of polishing is the movement amount L2 shown in FIG. 8, which is larger than the outer peripheral diameter of the polishing grindstone 524.

As described above, when comparing the present embodiment and the comparative example, it can be understood that the amount of movement of the polishing grindstone 524 for polishing the rectangular side surface W2a is smaller in the present embodiment. Therefore, it is possible to shorten the polishing time and efficiently carry out the polishing process by moving the polishing grindstone 524 in the thickness direction of the rectangular work W2 and polishing as in the embodiment.

The present invention is not limited to the above embodiment, and can be modified in various ways. In the above embodiment, the size, shape, direction, etc. shown in the attached drawings are not limited to this, and can be appropriately changed within the range in which the effects of the present invention are exhibited. In addition, it can be appropriately modified and implemented as long as it does not deviate from the scope of the object of the present invention.

For example, in the above embodiment, the case where the composite tool 52 is used has been described, but instead of this, polishing may be performed using a polishing tool provided with only the polishing wheel 523.

Further, during the polishing process, the direction in which the polishing wheel 524 is moved with respect to the rectangular work W2 may be upward. In this case, after the polishing wheel 524 is positioned at the positions in the X and Z directions shown by the two-point chain line in FIG. 7, the polishing surface 524a of the polishing wheel 524 acts on the rectangular side surface W2a of the rectangular work W2 in the Y direction. The rectangular work W2 is moved and positioned so as to do so. From this state, the rectangular side surface W2a is polished by moving the polishing wheel 524 upward to the position shown by the solid line in FIG. 7.

Further, in the above embodiment, the workpiece to be polished is a rectangular work W2, but instead, the rod-shaped portion W3 (see FIG. 5) is used as the workpiece, and the cut surface of the rod-shaped portion W3 has a rectangular shape. It may be polished as a rectangular side surface. In this case, the rod-shaped portion W3 is held and polished as shown in FIGS. 9A and 9B. 9A and 9B are explanatory views of a polishing process in a modified example, FIG. 9A shows a state during polishing, and FIG. 9B shows a state immediately after polishing. In the modified example, the surface of the rod-shaped portion W3 opposite to the rectangular side surface W3a is adhered to the plate-shaped jig 35 by an adhesive such as wax. Then, the lower surface of the jig 35 to which the rod-shaped portion W3 is adhered is placed on the holding surface 322a of the first fixing member 322 and held by suction, and the rod-shaped portion W3 is held so as to protrude from the outer edge of the first fixing member 322. To. Also in the modified example, by moving the polishing wheel 524 in the Z direction perpendicular to the holding surface 322a, the rectangular side surface W3a can be polished in the same manner as in the above embodiment.

As described above, the present invention has an effect that the rectangular side surface of the workpiece can be efficiently polished in a short time, and the side surface of the workpiece having high hardness such as a difficult-to-cut material is particularly good. It is useful for a polishing method that polishes with high surface accuracy.

10 Machining equipment 3 Holding means 31 Chuck table 322a Holding surface 5 Machining means 51 Spindle 52 Composite tool (machining tool)
523 Polishing wheel (polishing tool)
524 Grinding wheel 524a Polished surface 6 Machining means Moving mechanism (moving means)
W2 rectangular workpiece (workpiece)
W2a Rectangular side surface W3 Rod-shaped part (workpiece)
W3a rectangular side

Claims (1)

A machining means having a holding means having a horizontal holding surface for holding a work piece, a machining means having a spindle at the tip of which a machining tool is rotatably mounted on a rotation axis parallel to the holding surface, and the holding means and the machining. A rectangular shape of a workpiece held on the holding surface of the holding means by mounting a polishing tool on the spindle using a processing device including a moving means for moving the means in a direction of relatively approaching and separating. It is a polishing method that polishes the rectangular side surface of the shape.
The workpiece is held on the holding surface of the holding means with its rectangular side surface protruding from the outer peripheral edge of the holding means.
The polishing tool includes a polishing grindstone having an annular polishing surface on a predetermined circumference centered on the rotation axis, and the annular polishing grindstone accommodates the entire rectangular side surface of the workpiece. It is formed on the inner diameter and
In the polishing tool, the lower surface of the work piece is held by the holding surface, the axis of rotation is perpendicular to the holding surface of the holding means, and the upper side of the rectangular side surface of the work piece. A polishing method characterized in that the entire surface of the rectangular side surface is relatively moved from the side to a position accommodated in the inner diameter of the polishing grindstone to polish the rectangular side surface.

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