JP7680262B2 - Dresser Board - Google Patents

Description

The present invention relates to a dresser board.

Chips for devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are essential components in various electronic devices such as mobile phones and personal computers. Such chips are manufactured, for example, by dividing a wafer on which a large number of devices are formed into areas containing individual devices.

One example of a device used to divide a wafer is a cutting device. This cutting device has a chuck table that holds the wafer, and a cutting unit that includes a spindle with a cutting blade attached to its tip. Furthermore, this cutting blade has an annular cutting edge with abrasive grains dispersed in it. In the cutting device, the cutting blade is rotated and the outer circumferential surface of the cutting edge is brought into contact with the wafer, cutting and dividing the wafer.

However, in unused cutting blades, the outer peripheral surface of the cutting edge may not be perfectly round and/or the abrasive grains may not be sufficiently exposed on the outer peripheral surface of the cutting edge. Furthermore, when cutting chips produced by cutting adhere to the outer peripheral surface of the cutting edge, the abrasive grains may not be sufficiently exposed on this outer peripheral surface (the surface may become clogged). Furthermore, repeated cutting may cause the abrasive grains exposed on the outer peripheral surface of the cutting edge to wear down (become dull).

For this reason, cutting devices often perform a process (dressing) at an appropriate timing to grind the outer peripheral surface of the cutting edge of the cutting blade to prepare it for cutting. This dressing is performed, for example, in the following order. First, a plate-shaped dresser board (dressing board) with abrasive grains dispersed therein is held on a sub-chuck table (dressing board support table) provided near the chuck table. Then, the sub-chuck table is moved linearly so that the rotating cutting blade cuts into the surface side of the dresser board (see, for example, Patent Document 1).

JP 2011-16175 A

When the above-mentioned dressing is performed, the surface side of the dresser board is scraped. Therefore, this dressing is performed by shifting the position of the cutting blade each time the cutting blade cuts into the dresser board so that the outer peripheral surface of the cutting edge of the cutting blade comes into contact with the area of the dresser board that has not been scraped.

For example, when an area parallel to a first edge of the rectangular surface of a dresser board is to be dressed, an area slightly inside this first edge is first dressed. Then, in each subsequent dressing, an area further inside than the area previously dressed is first dressed.

However, such dressing is performed on the cutting edge of an unused cutting blade or on the cutting edge of a cutting blade that has become clogged and/or worn out from cutting a large number of wafers, and is not performed continuously. Therefore, when dressing is performed, it is necessary to re-identify the area of the dresser board to be used for dressing, taking into account the usage status of the dresser board.

Currently, this identification is performed manually by an operator of the cutting device. Specifically, the operator measures the distance between the first side of the surface of the dresser board and the desired area using a tape measure or the like, and inputs the measured distance value into the cutting device, thereby identifying this area as the area of the dresser board to be used for dressing.

However, the task of using a tape measure or the like to identify the area is cumbersome. In view of this, the object of the present invention is to provide a dresser board that can simplify the task of identifying the area of the dresser board to be used for dressing.

According to the present invention, there is provided a dresser board having a rectangular surface, in which a plurality of marks indicating the distance from a first side of the surface are displayed in an area along a second side of the surface perpendicular to the first side, each of the plurality of marks being a line segment extending from the second side along a direction parallel to the first side, and the plurality of marks being classified into two types according to their length .

In the dresser board of the present invention, a mark indicating the distance from the first side of the rectangular surface is displayed in an area along a second side perpendicular to the first side. This makes it easy to measure the distance between the area of the dresser board that can be used for the next dressing and the first side. As a result, the task of identifying the area of the dresser board to be used for dressing can be simplified.

FIG. 1 is a perspective view illustrating an example of a dresser board. FIG. 2 is a perspective view illustrating an example of a cutting device. FIG. 3(A) is a top view showing a schematic diagram of the sub-chuck table holding a new (unused) dresser board, and FIG. 3(B) is a front view showing a schematic diagram of the sub-chuck table holding a new (unused) dresser board. FIG. 4(A) is a top view showing a schematic diagram of the sub-chuck table holding a reusable second-hand (used) dresser board, and FIG. 4(B) is a front view showing a schematic diagram of the sub-chuck table holding a reusable second-hand (used) dresser board. FIG. 5 is a perspective view showing a typical modification of the dresser board.

An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a typical example of a dresser board. The dresser board 1 shown in FIG. 1 has a rectangular parallelepiped shape with a width and length that are 10 times or more larger than the thickness.

This dresser board 1 is manufactured by, for example, mixing green carborundum (GC) abrasive grains made of silicon carbide (SiC) or white alundum (WA) abrasive grains made of aluminum oxide (Al ₂ O ₃ ) with a binder made of resin and then firing the mixture.

The surface 3 of the dresser board 1 has a rectangular shape with a first side 3a and a second side 3b perpendicular to the first side 3a. In the area along the second side 3b of the surface 3, a number of marks 5 are displayed that function as a scale indicating the distance from the first side 3a.

Specifically, each of the multiple marks 5 is a line segment extending from the second side 3b along a direction parallel to the first side 3a. Furthermore, each of the multiple marks 5 is displayed at approximately equal intervals along a direction parallel to the second side 3b so that the distance from the first side 3a is 5 x k (k is a natural number equal to or less than 13) mm.

Furthermore, the multiple marks 5 are classified into two types according to the length of the line segment (the length in the width direction of the dresser board 1). Specifically, of the multiple marks 5, the marks (the former marks) that are approximately 5×l (l is a positive even number not exceeding 12) mm away from the first side 3a are longer than the marks that are approximately 5×m (m is a positive odd number not exceeding 13) mm away from the first side 3a.

In addition, in an area of the surface 3 located on the opposite side of the second side 3b from the former mark, a number 7 is displayed indicating the distance from the first side 3a. The marks 5 and the number 7 are applied to the surface 3 of the dresser board 1 by, for example, laser marking.

Figure 2 is a perspective view showing a schematic example of a cutting device in which dressing is performed using a dresser board 1. Note that the X-axis direction (front-back direction) and the Y-axis direction (left-right direction) shown in Figure 2 are directions perpendicular to each other on a horizontal plane, and the Z-axis direction (up-down direction) is a direction (vertical direction) perpendicular to the X-axis and Y-axis directions.

The cutting device 2 shown in FIG. 2 has a base 4 that supports each structure. A rectangular opening 4a is formed in the front corner of the base 4, and a cassette support table 6 that can rise and fall is provided within this opening 4a. A cassette 8 that contains multiple wafers 11 is placed on the upper surface of the cassette support table 6. Note that, for ease of explanation, only the outline of the cassette 8 is shown in FIG. 1.

The wafer 11 is made of a semiconductor material such as silicon, and its surface side is divided into a central device region and a peripheral surplus region surrounding the device region. This device region is further divided into multiple regions by planned division lines (streets) arranged in a grid pattern, and devices 15 such as ICs and LSIs are formed in each region.

A dicing tape 17 with a diameter larger than that of the wafer 11 is attached to the back side of the wafer 11. The outer periphery of the dicing tape 17 is fixed to an annular frame 19. In other words, the wafer 11 is supported by the frame 19 via the dicing tape 17.

A rectangular opening 4b that is long in the X-axis direction is formed on the side of the cassette support base 6. Inside this opening 4b, there are provided an X-axis moving table 10, an X-axis moving mechanism (not shown) that moves the X-axis moving table 10 along the X-axis direction, and a dustproof and drip-proof cover 12 that covers the X-axis moving mechanism.

A chuck table 14 for holding the wafer 11 is provided above the X-axis moving table 10. Four clamps 16 are arranged around the chuck table 14 to secure the annular frame 19 that supports the wafer 11 from all four sides.

The chuck table 14 is connected to a rotary drive source (not shown) such as a motor, and rotates about a straight line roughly parallel to the Z-axis direction as its axis of rotation. The chuck table 14 also moves along the X-axis direction together with the X-axis moving table 10.

The upper surface of the chuck table 14 is a holding surface 14a that holds the wafer 11. This holding surface 14a is connected to a suction source (not shown) through a suction passage or the like formed inside the chuck table 14.

A transport unit (not shown) is provided in the vicinity of the opening 4b to transport the wafer 11 to the chuck table 14. The wafer 11 is transported by the transport unit onto the holding surface 14a of the chuck table 14 so that, for example, the front side is exposed upward.

A gate-shaped support structure 24 for supporting the two cutting units 22 is disposed on the upper surface of the base 4 so as to straddle the opening 4b. Two cutting unit movement mechanisms 26 for moving each cutting unit 22 along the Y-axis and Z-axis directions are provided on the upper front surface of the support structure 24.

Each cutting unit movement mechanism 26 is fixed to the front surface of the support structure 24 and shares a pair of guide rails 28 extending along the Y-axis direction. A movement plate 30 is connected to the front surface of the pair of guide rails 28 in a manner that allows it to slide along the pair of guide rails 28.

Between the pair of guide rails 28, a screw shaft 32 extending along the Y-axis direction is disposed. A motor 34 for rotating the screw shaft 32 is connected to one end of the screw shaft 32. In addition, a nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 32 is provided on the surface of the screw shaft 32 on which the helical groove is formed, forming a ball screw.

In other words, when the screw shaft 32 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Y-axis direction. The nut portion is also fixed to the rear side of the moving plate 30. Therefore, when the screw shaft 32 is rotated by the motor 34, the moving plate 30 moves along the Y-axis direction together with the nut portion.

A pair of guide rails 36 extending along the Z-axis direction is fixed to the front surface of each moving plate 30. A moving plate 38 is connected to the front surface of the pair of guide rails 36 in a manner that allows it to slide along the pair of guide rails 36.

Between the pair of guide rails 36, a screw shaft 40 is disposed, which extends along the Z-axis direction. A motor 42 for rotating the screw shaft 40 is connected to one end of the screw shaft 40. In addition, a nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 40 is provided on the surface of the screw shaft 40 on which the helical groove is formed, forming a ball screw.

In other words, when the screw shaft 40 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Z-axis direction. The nut portion is also fixed to the rear side of the moving plate 38. Therefore, when the screw shaft 40 is rotated by the motor 42, the moving plate 38 moves along the Z-axis direction together with the nut portion.

A cutting unit 22 that cuts the wafer 11 is provided below each moving plate 38. The cutting unit 22 has a cylindrical spindle housing that extends along the Y-axis direction. A spindle that extends in the Y-axis direction is housed in this spindle housing. This spindle is supported by the spindle housing in a rotatable state.

The tip of the spindle is exposed outside the spindle housing, and a cutting blade 44 with an annular cutting edge is attached to this tip. The spindle housing also contains a rotational drive source (not shown) such as a motor that is connected to the base end of the spindle. Therefore, when the spindle is rotated by this rotational drive source, the cutting blade 44 rotates around a straight line along the Y-axis direction as its axis of rotation.

The cutting blade 44 is, for example, a hub-type cutting blade. A hub-type cutting blade is composed of an annular base made of metal or the like and an annular cutting edge formed along the outer periphery of the base. The cutting edge of this cutting blade is composed of an electroformed grinding wheel in which abrasive grains made of diamond or cubic boron nitride (cBN) or the like are fixed with a binder such as nickel.

Alternatively, the cutting blade 44 may be a washer-type cutting blade. A washer-type cutting blade is composed of an annular cutting edge with abrasive grains fixed by a binder such as metal, ceramic, or resin.

An imaging unit 46 is provided in front of the cutting unit 22. The imaging unit 46 has, for example, a light source such as an LED (Light Emitting Diode), an objective lens, and an imaging element such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

A circular opening 4c is formed in the front corner of the base 4, opposite the corner where the opening 4a is formed. A cleaning unit 48 is provided in this opening 4c for cleaning the wafer 11 etc. after cutting.

The X-axis moving table 10 of the cutting device 2 is provided with two sub-chuck tables 50. The sub-chuck tables 50 move along the X-axis direction together with the X-axis moving table 10. The upper surface of the sub-chuck table 50 serves as a holding surface that holds the dresser board 1.

This holding surface is connected to a suction source (not shown) through a suction path formed inside the sub-chuck table 50. FIG. 3(A) is a top view showing the sub-chuck table 50 in a state where it holds a new (unused) dresser board 1, and FIG. 3(B) is a front view showing the sub-chuck table 50 in a state where it holds a new (unused) dresser board 1.

The sub-chuck table 50 is supported by the X-axis moving table 10 via a support 52 fixed to the lower end of the front side of the sub-chuck table 50. The holding surface 50a of the sub-chuck table 50 is rectangular, with a pair of short sides extending along the X-axis direction and a pair of long sides extending along the Y-axis direction. The length of the short sides of the holding surface 50a is approximately equal to the width of the dresser board 1.

Furthermore, a pair of set screws 54 aligned along the X-axis direction are inserted in an area adjacent to one of the pair of short sides of the holding surface 50a. The distance between the other of the pair of short sides of the holding surface 50a and the pair of set screws 54 is approximately equal to the length of the dresser board 1.

The dresser board 1 is placed on the holding surface of the sub-chuck table 50 so that the side of the surface 3 opposite the first side 3a contacts the pair of set screws 54 and the second side 3b overlaps the long side of the holding surface 50a of the sub-chuck table 50. Then, by operating the suction source connected to this holding surface 50a, the dresser board 1 is suction-held to the sub-chuck table 50.

Dressing using the dresser board 1 in the cutting device 2 is performed, for example, in the following order. First, the cutting unit moving mechanism 26 adjusts the position of the cutting unit 22 in the Y-axis direction so that, in a top view, the area slightly inside the first side 3a of the surface 3 of the new (unused) dresser board 1 is positioned in the X-axis direction when viewed from the cutting edge of the cutting blade 44.

Then, the cutting unit moving mechanism 26 adjusts the position of the cutting unit 22 in the Z-axis direction so that the bottom end of the cutting edge of the cutting blade 44 is positioned lower than the surface 3 of the dresser board 1 and higher than the holding surface 50a of the sub-chuck table 50. Next, while rotating the cutting blade 44, the X-axis moving mechanism moves the sub-chuck table 50 together with the X-axis moving table 10 so that the cutting blade 44 passes over the dresser board 1 from one end to the other in the X-axis direction.

This completes the process (dressing) of grinding the outer peripheral surface of the cutting edge of the cutting blade 44 to make the cutting edge suitable for cutting (the outer peripheral surface becomes perfectly circular and/or the abrasive grains are sufficiently exposed on the outer peripheral surface). In addition, with this dressing, the front surface 3 side of the dresser board 1 is also ground, and a groove is formed along the X-axis direction in an area slightly inside the first edge 3a of the front surface 3.

Furthermore, if necessary, the same process may be repeated with the cutting blade 44 shifted in the Y-axis direction. In other words, multiple grooves may be formed in the surface 3 of the dresser board 1 by one dressing.

Figure 4(A) is a top view that shows a schematic of the sub-chuck table 50 holding a reusable second-hand (used) dresser board 1, and Figure 4(B) is a front view that shows a schematic of the sub-chuck table 50 holding a reusable second-hand (used) dresser board 1.

Specifically, Figures 4(A) and 4(B) show a dresser board 1 that has been dressed multiple times while shifting the area of the surface 3 that is subjected to dressing along the Y-axis direction. A number of grooves 3c are formed on the surface 3 of this dresser board 1 along the X-axis direction.

In the dresser board 1 shown in Figures 4(A) and 4(B), a number of marks 5 that indicate the distance from the first side 3a of the surface 3 are displayed in the area along the second side 3b. In addition, numbers indicating the distance from the first side 3a are displayed on the surface 3 of the dresser board 1.

This makes it easy to measure the distance (e.g., 17.5 mm) between the area of the dresser board 1 that can be used for the next dressing and the first side 3a of the dresser board 1. As a result, the task of identifying the area of the dresser board 1 that can be used for dressing can be simplified.

The above-mentioned dresser board 1 is one aspect of the present invention, and dresser boards having features different from those of the dresser board 1 are also included in the present invention. For example, the number of marks displayed on the surface of the dresser board of the present invention may be one.

The multiple marks displayed on the surface of the dresser board of the present invention only need to be an indication of the distance from the first side, and are not limited to lines parallel to this first side. Figure 5 is a perspective view showing a schematic example of a dresser board on which multiple marks different from the multiple marks 5 displayed on the surface 3 of the dresser board 1 are displayed.

The surface 23 of the dresser board 21 shown in FIG. 5 has a rectangular shape with a first side 23a and a second side 23b perpendicular to the first side 23a. In addition, a plurality of marks 25 that function as a scale indicating the distance from the first side 23a are displayed in the area along the second side 23b of the surface 23. Specifically, each of the plurality of marks 25 is polygonal, and is displayed at approximately equal intervals along a direction parallel to the second side 23b.

In addition, the structures and methods of the above-described embodiments can be modified as appropriate without departing from the scope of the present invention.

1: Dresser board 3: Surface (3a: first side, 3b: second side)
5: Mark 7: Number 2: Cutting device 4: Base (4a, 4b, 4c: opening)
6: Cassette support table 8: Cassette 10: X-axis moving table 11: Wafer 12: Dust-proof/water-proof cover 14: Chuck table (14a: holding surface)
15: Device 16: Clamp 17: Dicing tape 19: Frame 22: Cutting unit 24: Support structure 26: Cutting unit moving mechanism 28: Guide rail 30: Moving plate 32: Screw shaft 34: Motor 36: Guide rail 38: Moving plate 40: Screw shaft 42: Motor 44: Cutting blade 46: Imaging unit 48: Cleaning unit 21: Dresser board 23: Surface (23a: first side, 23b: second side)
25: Mark

Claims (1)

A dresser board having a rectangular surface,
a plurality of marks indicating distances from a first side of the surface are displayed in an area along a second side of the surface perpendicular to the first side ;
each of the plurality of marks is a line segment extending from the second side along a direction parallel to the first side;
The plurality of marks are classified into two types according to their lengths .

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