JP7798511B2 - Jig and workpiece processing method - Google Patents

Description

The present invention relates to a jig for suction-holding a workpiece on the suction surface of a chuck table, and a method for processing a workpiece using the jig to suction-hold the workpiece on the suction surface of a chuck table and process the workpiece.

The device chip manufacturing process uses a disk-shaped wafer with devices formed in multiple areas defined by multiple intersecting streets (planned division lines). By dividing this wafer along the streets, multiple device chips, each equipped with a device, are obtained. The device chips are incorporated into various electronic devices such as mobile phones and personal computers.

A cutting device is used to divide the wafers. The cutting device is equipped with a chuck table that holds the workpiece and a processing unit (cutting unit) that performs the cutting process on the workpiece, and an annular cutting blade is attached to the cutting unit. The cutting blade is rotated and cuts into the workpiece, cutting and dividing the workpiece.

In recent years, the miniaturization of electronic devices has led to a demand for thinner device chips. To address this, a process is sometimes carried out in which wafers before being divided are ground using a grinding device. The grinding device is equipped with a chuck table that holds the workpiece and a processing unit (grinding unit) that performs the grinding process on the workpiece. A grinding wheel containing multiple grinding stones is attached to the grinding unit. The workpiece is ground and thinned by bringing the grinding stones into contact with the workpiece while rotating the grinding wheel.

Processing equipment such as cutting machines and grinding machines are highly versatile and can process workpieces of various sizes, shapes, and materials. For example, Patent Document 1 discloses a grinding machine that can grind rectangular, plate-shaped workpieces.

JP 2016-150421 A

The chuck table mounted on the processing device has a suction surface that attracts the workpiece. When processing a workpiece with the processing device, the workpiece is placed on the chuck table so that it covers the suction surface. In this state, suction force is applied to the suction surface, and the workpiece is held by suction on the suction surface.

To ensure that the workpiece is reliably held by suction on the chuck table, it is preferable that the overlapping area between the workpiece and the suction surface be as large as possible, and that the entire suction surface be covered by the workpiece. Therefore, the dimensions and shape of the suction surface of the chuck table are set according to the dimensions and shape of the workpiece to be processed.

When processing various types of workpieces with different dimensions or shapes using a single processing device, a chuck table with a suction surface suitable for suction holding of the workpieces must be manufactured in advance for each type of workpiece. This requires time and cost to prepare the chuck table. Furthermore, if the type of workpiece is changed while the processing device is in operation, processing must be interrupted and the chuck table replaced each time. This reduces the operating efficiency of the processing device.

The present invention was made in consideration of these problems, and aims to provide a jig that enables various types of workpieces to be held on a chuck table, and a method for processing workpieces using the jig.

According to one aspect of the present invention, there is provided a jig for suction-holding a workpiece , which includes a first surface, a second surface, and side surfaces connected to the first surface and the second surface , on a suction surface of a chuck table, the jig comprising a covering member and a plurality of covers each including an elastic member that contacts the side surface of the workpiece and deforms to conform to the shape of the side surface of the workpiece, the plurality of covers being arranged so that the covering member contacts an exposed area of the suction surface that is not covered by the workpiece and the elastic member contacts the side surface of the workpiece and the covering member of another cover, and when the workpiece is processed while being sucked by the suction surface, the entire area is covered by the plurality of covers .

Preferably, the thickness of the covering member and the elastic member is less than the thickness of the workpiece. Also, preferably, the elastic member is a sponge with liquid-absorbent properties.

According to another aspect of the present invention, there is provided a method for machining a workpiece using a jig to suction-hold a workpiece, the workpiece including a first surface, a second surface, and side surfaces connected to the first surface and the second surface, on a suction surface of a chuck table to machine the workpiece, the jig having a plurality of covers including a covering member and an elastic member that contacts the side surfaces of the workpiece and deforms to follow the shape of the side surfaces of the workpiece, the method comprising: a placing step of placing the workpiece on the suction surface; a holding step of arranging the plurality of covers so that the covering member contacts an exposed area of the suction surface that is not covered by the workpiece and the elastic member contacts the side surfaces of the workpiece and the covering members of other covers , and applying suction force to the suction surface with the workpiece and the plurality of covers covering the suction surface, thereby suction-holding the workpiece and the plurality of covers on the chuck table; and a machining step of machining the workpiece with the workpiece being sucked by the suction surface and the entire area covered by the plurality of covers .

Preferably, the thickness of the covering member and the thickness of the elastic member are less than the thickness of the workpiece, and in the placing step, the workpiece is placed on the suction surface so that the first surface of the workpiece is exposed and the second surface of the workpiece faces the suction surface, and in the processing step, the entire first surface side of the workpiece is ground with a grinding wheel. Also, preferably, the elastic member is a sponge having liquid absorption properties, and in the processing step, the workpiece is processed while supplying processing fluid to the workpiece and the elastic member.

A jig according to one aspect of the present invention comprises multiple covers, including a covering member that covers the exposed area of the suction surface of the chuck table and an elastic member that deforms to fit the shape of the side surface of the workpiece. By placing the jig on the suction surface when holding a workpiece on the chuck table, a strong suction force can be applied to various types of workpieces with different dimensions or shapes, allowing the workpiece to be securely held by the chuck table. This eliminates the need to manufacture a different chuck table for each type of workpiece, reducing the time and cost required to prepare chuck tables. It also eliminates the need to replace chuck tables, preventing a decrease in the operating efficiency of the processing equipment.

FIG. FIG. 2 is a perspective view showing a chuck table. FIG. 3A is a perspective view showing the chuck table and the jig, and FIG. 3B is a cross-sectional view showing the chuck table and the jig. FIG. 4A is a perspective view showing a workpiece and a jig held by suction on the chuck table, and FIG. 4B is a cross-sectional view showing the workpiece and a jig held by suction on the chuck table. FIG. 2 is a partial cross-sectional side view showing the grinding device and the workpiece in a processing step. FIG. 6A is a perspective view showing a chuck table according to a modified example, and FIG. 6B is a cross-sectional view showing a workpiece and a jig that are suction-held by the chuck table according to the modified example.

An embodiment of the present invention will now be described with reference to the accompanying drawings. First, an example configuration of a processing device capable of processing a workpiece using a jig according to this embodiment will be described. Figure 1 is a perspective view showing a grinding device 2. Note that in Figure 1, the X-axis direction (first horizontal direction, front-to-back direction) and the Y-axis direction (second horizontal direction, left-to-right direction) are mutually perpendicular. Furthermore, the Z-axis direction (vertical direction, up-down direction, height direction) is a direction perpendicular to the X-axis direction and the Y-axis direction.

The grinding device 2 includes a base 4 that supports or houses each of the components that make up the grinding device 2. A rectangular parallelepiped opening 4a is provided on the top surface of the base 4, with its longitudinal direction aligned with the X-axis direction. Furthermore, a rectangular parallelepiped support structure 6 is provided at the rear end of the top surface of the base 4, aligned with the Z-axis direction.

A chuck table (holding table) 8 is provided inside the opening 4a to hold the workpiece 11, which is the object to be machined by the grinding device 2. The upper surface of the chuck table 8 is a flat surface that is roughly parallel to the horizontal plane (XY plane), and forms a holding surface 8a that holds the workpiece 11. A movement mechanism (moving unit) 10 that moves the chuck table 8 along the X-axis direction is connected to the chuck table 8.

For example, the movement mechanism 10 is a ball screw type movement mechanism and includes a flat movement plate (not shown). A nut portion is provided on the back surface (lower surface) of the movement plate, and a ball screw (not shown) arranged along the X-axis direction is threadedly engaged with this nut portion. A pulse motor (not shown) is connected to the end of the ball screw. A chuck table 8 is mounted on the front surface (upper surface) of the movement plate. When the ball screw is rotated by the pulse motor, the chuck table 8 moves along the X-axis direction together with the movement plate.

The chuck table 8 is also connected to a rotational drive source (not shown), such as a motor, that rotates the chuck table 8 around a rotation axis that is generally perpendicular to the holding surface 8a of the chuck table 8 (generally parallel to the Z-axis direction). In other words, the rotation axis of the chuck table 8 is set along a direction perpendicular to the holding surface 8a.

A table cover 12 is provided around the chuck table 8, surrounding it. Additionally, accordion-shaped dust-proof and drip-proof covers 14 that are extendable and contractible along the X-axis direction are provided in front and behind the table cover 12. The table cover 12 and dust-proof and drip-proof covers 14 cover the components of the movement mechanism 10 (moving plate, ball screw, pulse motor, etc.) that are provided inside the opening 4a.

A movement mechanism (movement unit) 16 is provided on the front side of the support structure 6. The movement mechanism 16 has a pair of guide rails 18 arranged along the Z-axis direction. A flat movement plate 20 is attached to the pair of guide rails 18 so that it can slide along the guide rails 18.

A nut portion (not shown) is provided on the back (rear) side of the movable plate 20. A ball screw 22, which is arranged along the Z-axis direction between a pair of guide rails 18, is threadedly engaged with this nut portion. A pulse motor 24 that rotates the ball screw 22 is connected to the end of the ball screw 22. When the ball screw 22 is rotated by the pulse motor 24, the movable plate 20 moves (raises and lowers) in the Z-axis direction along the guide rails 18.

A support member 26 is fixed to the surface (front) side of the movable plate 20. The support member 26 supports a processing unit (grinding unit) 28 that performs grinding on the workpiece 11. The processing unit 28 has a cylindrical housing 30 supported by the support member 26. The housing 30 also contains a cylindrical spindle 32 arranged along the Z-axis direction.

The tip (lower end) of the spindle 32 protrudes downward from the underside of the housing 30. A disk-shaped mount 34 made of metal or the like is fixed to the tip of the spindle 32. A rotational drive source (not shown), such as a motor, that rotates the spindle 32 is connected to the base (upper end) of the spindle 32.

An annular grinding wheel 36 that grinds the workpiece 11 is attached to the underside of the mount 34. For example, the grinding wheel 36 is fixed to the mount 34 with a fastener (not shown) such as a bolt. This allows the grinding wheel 36 to be attached to the tip of the spindle 32 via the mount 34.

The grinding wheel 36 comprises an annular wheel base 38 and multiple grinding stones 40 fixed to the wheel base 38. The wheel base 38 is made of a metal such as stainless steel or aluminum, and is formed to have roughly the same diameter as the mount 34. On the underside of the wheel base 38, multiple grinding stones 40, each shaped like a rectangular parallelepiped, are arranged at roughly equal intervals along the outer periphery of the wheel base 38.

The grinding wheel 40 contains abrasive grains made of diamond, cBN (cubic boron nitride), or the like, and a bonding material (bond material) that secures the abrasive grains. Bond materials that can be used include metal bonds, resin bonds, and vitrified bonds. However, there are no restrictions on the material, dimensions, shape, etc. of the grinding wheel 40. The number of grinding wheels 40 can also be set as desired.

The grinding wheel 36 rotates around a rotation axis that is generally perpendicular to the holding surface 8a of the chuck table 8 (generally parallel to the Z-axis direction) by power transmitted from the rotation drive source via the spindle 32 and mount 34. In other words, the rotation axis of the grinding wheel 36 is set along a direction perpendicular to the holding surface 8a of the chuck table 8.

The grinding device 2 also includes a control unit (control unit, control device) 42 connected to each component of the grinding device 2 (chuck table 8, movement mechanism 10, movement mechanism 16, processing unit 28, etc.). The control unit 42 generates control signals that control the operation of the components of the grinding device 2.

For example, the control unit 42 is configured by a computer and includes a calculation unit that performs calculations to operate the grinding device 2, and a storage unit that stores various information (data, programs, etc.) used to operate the grinding device 2. The calculation unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as a ROM (Read Only Memory) and RAM (Random Access Memory).

The grinding device 2 grinds the workpiece 11. For example, the workpiece 11 is a rectangular, plate-shaped member (plate-like object) made of glass (quartz glass, borosilicate glass, soda-lime glass, alkali-free glass, etc.). Specifically, the workpiece 11 includes a front surface (first surface) 11a and a back surface (second surface) 11b that are generally parallel to each other, and four side surfaces (outer peripheral surfaces) 11c connected to the front surface 11a and back surface 11b. By processing the workpiece 11, various items (optical components, etc.) are manufactured.

However, there are no restrictions on the type, material, dimensions, shape, structure, etc. of the workpiece 11. For example, the workpiece 11 may be a wafer (substrate) made of a semiconductor (Si, GaAs, InP, GaN, SiC, etc.), ceramic, resin, metal, etc. The workpiece 11 may also be a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate. For example, a package substrate is formed by sealing devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) mounted on a base substrate with a resin layer (mold resin).

When grinding the workpiece 11 with the grinding device 2, the workpiece 11 is held by the chuck table 8. Figure 2 is a perspective view showing the chuck table 8.

The chuck table 8 has a cylindrical frame (main body) 50 made of metal such as SUS (stainless steel), glass, ceramics, resin, etc. A cylindrical recess (groove) 50b is provided in the center of the top surface 50a of the frame 50. The diameter of the recess 50b is smaller than the diameter of the frame 50, and the recess 50b is provided concentrically with the frame 50.

A disk-shaped holding member 52 made of a porous material such as porous ceramics is fitted and fixed in the recess 50b. The holding member 52 contains internal pores (flow paths) that connect the top surface to the bottom surface of the holding member 52. The top surface of the holding member 52 forms a circular suction surface 52a that sucks the workpiece 11. The suction surface 52a is connected to a suction source 56 such as an ejector via the pores contained in the holding member 52, a flow path (not shown) formed inside the frame 50, a valve 54, etc.

The depth of the recess 50b and the thickness of the holding member 52 are set to be approximately the same, and the upper surface 50a of the frame 50 and the suction surface 52a are positioned on approximately the same plane. The upper surface 50a of the frame 50 and the suction surface 52a form the holding surface 8a of the chuck table 8.

The workpiece 11 is placed on the chuck table 8 so that it overlaps with the suction surface 52a. When the suction force (negative pressure) of the suction source 56 is applied to the suction surface 52a in this state, the workpiece 11 is held by suction on the chuck table 8.

However, depending on the size and shape of the workpiece 11, when the workpiece 11 is placed on the suction surface 52a, part of the suction surface 52a may be exposed and not covered by the workpiece 11. For example, as shown in Figure 2, if the diagonal of the rectangular workpiece 11 is smaller than the diameter of the suction surface 52a, part of the suction surface 52a will be exposed outside the four sides of the workpiece 11. In this state, even if negative pressure from the suction source 56 is applied to the suction surface 52a, the negative pressure will leak from the exposed area of the suction surface 52a, and the suction force acting on the workpiece 11 will be insufficient.

In this embodiment, the workpiece 11 is held by the chuck table 8 using a cover that covers the exposed area of the suction surface 52a that is not covered by the workpiece 11. This prevents negative pressure from leaking from the suction surface 52a, even if the workpiece 11 cannot cover the entire suction surface 52a, and the workpiece 11 is reliably held by suction on the chuck table 8.

Figure 3(A) is a perspective view showing the chuck table 8 and jig 60, and Figure 3(B) is a cross-sectional view showing the chuck table 8 and jig 60. The jig 60 is a member for suction-holding the workpiece 11 on the suction surface 52a of the chuck table 8, and is equipped with multiple covers 62 that cover the suction surface 52a.

The multiple covers 62 close off the suction surface 52a by covering the exposed areas (exposed areas) of the suction surface 52a of the chuck table 8 that are not covered by the workpiece 11. For example, the jig 60 has four covers 62 (covers 62A, 62B, 62C, and 62D) that surround the rectangular workpiece 11 on all four sides.

Each of the multiple covers 62 includes a covering member 64 that covers the exposed area of the suction surface 52a. The covering member 64 includes a front surface (first surface) 64a and a back surface (second surface) 64b that are generally parallel to each other, and a first side surface 64c and a second side surface (outer peripheral surface) 64d connected to the front surface 64a and back surface 64b. The covering member 64 is a plate-like member that can cover the exposed area of the suction surface 52a, and is formed according to the dimensions and shape of the workpiece 11 and the suction surface 52a.

For example, the covering member 64 of the covers 62A and 62B is formed in an arch shape so that the first side surface 64c follows the side surface 11c of the workpiece 11 and the second side surface 64d follows the outer peripheral edge of the frame body 50. For example, the covering member 64 of the covers 62C and 62D is formed in a generally rectangular shape with one curved side so that the first side surface 64c follows the side surface 11c of the workpiece 11 and the second side surface 64d follows the outer peripheral edge of the frame body 50. The first side surface 64c of the covering member 64 provided on the covers 62A and 62B is longer than the side surface 11c of the workpiece 11. On the other hand, the length of the first side surface 64c of the covering member 64 provided on the covers 62C and 62D is approximately the same as the length of the side surface 11c of the workpiece 11.

The material of the covering member 64 is appropriately selected so that when the covering member 64 is placed on the suction surface 52a, the area of the suction surface 52a that overlaps with the covering member 64 is blocked. For example, the covering member 64 is a plate-like object made of a non-porous material (resin, metal, glass, ceramics, etc.) that blocks the pores of the holding member 52 that are exposed on the suction surface 52a. The thickness of the covering member 64 can be appropriately set within a range that allows the covering member 64 to be placed flat on the suction surface 52a. For example, the thickness of the covering member 64 is 3 mm or more and 30 mm or less.

An elastic member 66 that contacts the side surface 11c of the workpiece 11 is provided on the first side surface 64c of the covering member 64. The elastic member 66 is a flexible member that elastically deforms when an external force is applied, and is fixed to the covering member 64 so as to cover the first side surface 64c. For example, the elastic member 66 is formed in a generally triangular shape in cross section so that it becomes thinner toward the tip (see Figure 3(B)). Furthermore, the width of the elastic member 66 (the length in the direction perpendicular to the first side surface 64c of the covering member 64) is set to, for example, 3 mm or more and 15 mm or less.

There are no restrictions on the material of the elastic member 66, as long as it is deformable when it comes into contact with the side surface 11c of the workpiece 11. For example, resin, synthetic rubber, etc. can be used as the elastic member 66. Alternatively, a liquid-absorbent sponge (urethane foam, polyethylene foam, rubber sponge, etc.) can also be used as the elastic member 66.

Each of the multiple covers 62 is placed on the chuck table 8 so that the covering member 64 covers the suction surface 52a and the elastic member 66 contacts the side surface 11c of the workpiece 11. Specifically, covers 62A, 62B, 62C, and 62D are placed so as to surround the rectangular workpiece 11 on all four sides.

Figure 4(A) is a perspective view showing the workpiece 11 and jig 60 held by suction on the chuck table 8, and Figure 4(B) is a cross-sectional view showing the workpiece 11 and jig 60 held by suction on the chuck table 8. The covers 62A and 62B are arranged to sandwich the workpiece 11 in the Y-axis direction. The covers 62C and 62D are arranged to sandwich the workpiece 11 in the X-axis direction. As a result, the exposed area of the suction surface 52a is covered by the covering member 64, and the elastic member 66 comes into contact with the side surfaces 11c (four sides) of the workpiece 11. As a result, the exposed area of the suction surface 52a is blocked by the covers 62A, 62B, 62C, and 62D.

When the elastic member 66 comes into contact with the workpiece 11, the elastic member 66 deforms to conform to (follow) the shape of the side surface 11c of the workpiece 11. This improves the adhesion between the side surface 11c of the workpiece 11 and the elastic member 66. Furthermore, the deformation of the elastic member 66 prevents damage to the side surface 11c of the workpiece 11 when the workpiece 11 comes into contact with the elastic member 66. Furthermore, the elastic members 66 of the covers 62A and 62B also come into contact with and deform both ends of the covering members 64 of the covers 62C and 62D (side surfaces other than the first side surface 64c and second side surface 64d). This also improves the adhesion between the covers 62.

Then, with the suction surface 52a covered by the workpiece 11 and the multiple covers 62, the valve 54 is opened to apply the suction force of the suction source 56 to the suction surface 52a. This causes the workpiece 11 and the multiple covers 62 to be suction-held on the suction surface 52a. Note that if the elastic member 66 is a sponge, a small amount of the negative pressure acting on the suction surface 52a will leak through pores within the sponge, but because most of the suction surface 52a is covered by the workpiece 11 and covering member 64, this does not interfere with the suction-holding of the workpiece 11 and covers 62.

The above-mentioned jig 60 is manufactured for each type of workpiece 11, which has different dimensions or shapes. When the type of workpiece 11 to be ground by the grinding device 2 is changed, the jig 60 is replaced with one that is suitable for the new workpiece 11. This makes it possible for the chuck table 8 to suction-hold a variety of workpieces 11 with different dimensions or shapes without making any changes to the chuck table 8.

Furthermore, the time and cost required to manufacture the jig 60 is extremely small compared to the chuck table 8. For example, the jig 60 can be manufactured quickly and at low cost by forming a resin plate-like object (covering member 64) using a 3D printer or the like, and then fixing a sponge or the like (elastic member 66) to this plate-like object using adhesive or the like.

There are no restrictions on the number, size, or shape of the covers 62, as long as they can cover the entire exposed area of the suction surface 52a. For example, the jig 60 may be composed of two covers 62 that sandwich the workpiece 11.

Next, a specific example of a method for processing a workpiece using the jig 60 will be described. As an example, the following describes processing in which the surface 11a side of the workpiece 11 is ground to thin the workpiece 11. When grinding the surface 11a side of the workpiece 11, the cover 62 is designed so that the thickness Tc of the cover 62 (the thickness of the covering member 64 and elastic member 66) is smaller than the thickness Tw of the workpiece 11, as shown in Figure 4 (B).

First, as shown in FIG. 2, the workpiece 11 is placed on the suction surface 52a of the chuck table 8 (placement step). The workpiece 11 is placed on the suction surface 52a so that the front surface 11a (surface to be ground) is exposed upward and the back surface 11b faces the suction surface 52a. It is preferable that the workpiece 11 is positioned so that the entire back surface 11b overlaps the suction surface 52a. This increases the suction force acting on the workpiece 11. However, if the workpiece 11 does not fit inside the suction surface 52a, part of the workpiece 11 may be supported by the upper surface 50a of the frame 50.

A protective member for protecting the workpiece 11 may also be attached to the back surface 11b of the workpiece 11. In this case, the workpiece 11 is held by suction on the chuck table 8 via the protective member. For example, a rectangular tape (protective tape) formed in roughly the same shape as the back surface 11b of the workpiece 11 is used as the protective member.

Next, the workpiece 11 and jig 60 are suction-held on the chuck table 8 (holding step). In the holding step, first, the jig 60 is placed on the chuck table 8. Specifically, as shown in FIGS. 3(A) and 3(B), multiple covers 62 are placed to surround the workpiece 11. As a result, the exposed area of the suction surface 52a of the chuck table 8 that is not covered by the workpiece 11 is covered with the covering member 64. In addition, the elastic member 66 comes into contact with the side surface 11c of the workpiece 11, and the elastic member 66 deforms to conform to the side surface 11c of the workpiece 11. As a result, the exposed area of the suction surface 52a is blocked by the jig 60 (see FIGS. 4(A) and 4(B)).

Then, with the suction surface 52a blocked by the workpiece 11 and the multiple covers 62, the valve 54 is opened and the suction force of the suction source 56 is applied to the suction surface 52a. As a result, the workpiece 11 and the multiple covers 62 are held by suction on the chuck table 8. Note that the workpiece 11 and covers 62 may also be placed on the chuck table 8 with the suction force of the suction source 56 applied to the suction surface 52a.

Next, the workpiece 11 held by suction on the chuck table 8 is machined (machining step). Figure 5 is a partial side cross-sectional view showing the grinding device 2 and workpiece 11 during the machining step. The grinding device 2 is equipped with a liquid supply unit (liquid supply nozzle) 44 near the machining unit 28, which supplies a liquid (machining fluid) 46 such as pure water.

In the processing step, first, the chuck table 8 is moved along the X-axis direction by the movement mechanism 10 (see Figure 1) and positioned below the processing unit 28. At this time, the chuck table 8 is positioned so that the rotation axis of the workpiece 11 (the rotation axis of the chuck table 8) overlaps with the orbit (rotation path) of the grinding wheel 40.

Next, while rotating the chuck table 8 and spindle 32, the processing unit 28 is lowered by the movement mechanism 16 (see Figure 1). As a result, the rotating grinding wheel 36 descends toward the workpiece 11, and the multiple grinding stones 40 come into contact with the surface 11a of the workpiece 11. As a result, the entire surface 11a of the workpiece 11 is ground by the grinding stones 40, thinning the workpiece 11. Then, when the thickness of the workpiece 11 reaches the target value (finishing thickness), grinding of the workpiece 11 is stopped.

While the workpiece 11 is being ground, a liquid 46 such as pure water is supplied from the liquid supply unit 44 to the workpiece 11 and grinding wheel 40 at a predetermined flow rate. This cools the workpiece 11 and grinding wheel 40 and washes away any debris (processing debris) generated during the grinding process.

In addition, while the workpiece 11 is being ground, the liquid 46 is also continuously supplied to the elastic member 66. If the elastic member 66 is a sponge with liquid-absorbent properties, the sponge remains permeated with the liquid 46. For example, if the elastic member 66 is water-absorbent, pure water supplied as the liquid 46 will soak into the elastic member 66. As a result, the pores inside the sponge are blocked by the liquid 46. This improves the sealing performance of the suction surface 52a of the chuck table 8, and strengthens the suction force acting on the workpiece 11.

When thinning the workpiece 11 to a predetermined finishing thickness, it is preferable to set the thickness Tc of the cover 62 (see Figure 4(B)) to less than the finishing thickness. This prevents contact between the grinding wheel 40 and the cover 62 while grinding the workpiece 11, making it easier to grind the workpiece 11.

However, if only the area inside the outer periphery of the workpiece 11 is ground, the grinding wheel 36 does not overlap the cover 62 while the workpiece 11 is being ground, so there is no limit to the thickness of the cover 62. For example, if only the center of the workpiece 11 is ground using a small-diameter grinding wheel 36 whose diameter is less than the width of the workpiece 11, the thickness of the cover 62 may be equal to or greater than the thickness of the workpiece 11. Furthermore, if the covering member 64 and elastic member 66 are easily ground by the grinding wheel 40 and do not interfere with the grinding of the workpiece 11, there is no limit to the thickness of the cover 62.

As described above, the jig 60 according to this embodiment includes multiple covers 62, each including a covering member 64 that covers the exposed area of the suction surface 52a of the chuck table 8 and an elastic member 66 that deforms to fit the shape of the side surface 11c of the workpiece 11. By placing the jig 60 on the suction surface 52a together with the workpiece 11, a strong suction force can be applied to various types of workpieces 11 with different dimensions or shapes, allowing the workpieces 11 to be securely held by the chuck table 8. This eliminates the need to manufacture a different chuck table 8 for each type of workpiece 11, reducing the time and cost required to prepare the chuck table 8. Furthermore, the need to replace the chuck table 8 is eliminated, preventing a decrease in the operating efficiency of the grinding device 2.

Note that the chuck table mounted on the grinding device 2 is not limited to the chuck table 8 described above. Figure 6(A) is a perspective view showing a modified chuck table (holding table) 70, which has a different structure from the chuck table 8.

The chuck table 70 includes a cylindrical frame (main body) 72 made of metal such as SUS (stainless steel), glass, ceramics, resin, or the like. A cylindrical recess (groove) 72b is provided in the center of the upper surface 72a of the frame 72. The diameter of the recess 72b is smaller than the diameter of the frame 72, and the recess 72b is provided concentrically with the frame 72. The recess 72b is connected to the suction source 56 via a flow path (not shown) formed inside the frame 72, a valve 54, or the like.

The recess 72b is provided with multiple pins 74. For example, the pins 74 are cylindrical and are arranged from the bottom surface of the recess 72b toward the top surface. The depth of the recess 72b and the height of the pins 74 are set to be roughly the same, and the top surface 72a of the frame 72 and the top surfaces of the pins 74 are arranged on roughly the same plane. In other words, the top surface of the recess 72b corresponds to a circular plane that includes the top surfaces of the multiple pins 74. The top surface of the recess 72b also forms a suction surface 76 that sucks the workpiece 11. The top surface 72a of the frame 72 and the suction surface 76 form the holding surface 70a of the chuck table 70.

Figure 6(B) is a cross-sectional view showing the workpiece 11 and jig 60 held by suction on the chuck table 70. The workpiece 11 is placed on the chuck table 70 so that it overlaps the suction surface 76, and is supported by the upper surfaces of multiple pins 74. In addition, multiple covers 62 are placed to cover the exposed areas of the suction surface 76 that are not covered by the workpiece 11 (exposed areas), and are supported by the upper surfaces of the multiple pins 74. The specific method for arranging the covers 62 in this case is as described above (see Figures 3(A) and 4(A), etc.).

When the workpiece 11 and jig 60 are placed on the chuck table 70 and the recess 72b is depressurized by the suction source 56, a suction force acts on the suction surface 76, and the workpiece 11 and multiple covers 62 are held by suction on the suction surface 76. In this way, even on a chuck table 70 that holds the workpiece 11 with multiple pins 74, the use of the jig 60 makes it possible to properly hold the workpiece 11 by suction.

In addition, in the above embodiment, an example was described in which the jig 60 is used in the grinding device 2, but the jig 60 can also be used in other processing devices, cleaning devices, etc. For example, the jig 60 can also be used in a cutting device that cuts a workpiece, a polishing device that polishes a workpiece, a laser processing device that performs laser processing on a workpiece, etc.

The cutting device comprises a chuck table that holds the workpiece, and a processing unit (cutting unit) that cuts the workpiece. The cutting unit has a spindle, the tip of which is fitted with an annular cutting blade. The workpiece is cut by cutting the rotating cutting blade into the workpiece held by the chuck table. While the workpiece is being cut, a liquid (cutting fluid) such as pure water is supplied to the workpiece and the cutting blade.

The polishing apparatus comprises a chuck table that holds the workpiece, and a processing unit (polishing unit) that polishes the workpiece. The polishing unit has a spindle, the tip of which is fitted with a disc-shaped polishing pad. The workpiece held by the chuck table is polished by bringing the rotating polishing pad into contact with the workpiece. A liquid (processing fluid) such as slurry may be supplied to the workpiece and polishing pad while the workpiece is being polished.

The laser processing device includes a chuck table that holds the workpiece, and a processing unit (laser irradiation unit) that irradiates the workpiece with a laser beam. The laser irradiation unit includes a laser oscillator that emits a laser of a predetermined wavelength, and a condenser that focuses the laser beam emitted from the laser oscillator. Laser processing is performed on the workpiece 11 by irradiating the laser beam onto the workpiece held by the chuck table.

The jig 60 can also be used when suction-holding workpieces on the chuck tables mounted on the above-mentioned cutting devices, polishing devices, laser processing devices, etc. This makes it possible to suction-hold workpieces of various sizes and shapes in various processing devices.

In addition, the structures, methods, etc. related to the above embodiments can be modified as appropriate without departing from the scope of the present invention.

11 Workpiece 11a Surface (first surface)
11b Back side (second side)
11c Side surface (outer surface)
2 Grinding device 4 Base 4a Opening 6 Support structure 8 Chuck table (holding table)
8a Holding surface 10 Moving mechanism (moving unit)
12 table cover 14 dustproof/waterproof cover 16 moving mechanism (moving unit)
18 Guide rail 20 Moving plate 22 Ball screw 24 Pulse motor 26 Support member 28 Processing unit (grinding unit)
30 Housing 32 Spindle 34 Mount 36 Grinding wheel 38 Wheel base 40 Grinding stone 42 Control unit (control unit, control device)
44 Liquid supply unit (liquid supply nozzle)
46 Liquid (processing fluid)
50 Frame (main body)
50a Upper surface 50b Recess (groove)
52 Holding member 52a Suction surface 54 Valve 56 Suction source 60 Jig 62, 62A, 62B, 62C, 62D Cover 64 Covering member 64a Surface (first surface)
64b Back side (second side)
64c First side surface 64d Second side surface (outer peripheral surface)
66 Elastic member 70 Chuck table (holding table)
70a Holding surface 72 Frame (main body)
72a Upper surface 72b Recess (groove)
74 Pin 76 Suction surface

Claims (6)

A jig for suction-holding a workpiece, the workpiece including a first surface, a second surface, and a side surface connected to the first surface and the second surface, on a suction surface of a chuck table,
a plurality of covers including a covering member and an elastic member that comes into contact with the side surface of the workpiece and deforms to follow the shape of the side surface of the workpiece ;
each of the plurality of covers is arranged such that the covering member contacts an exposed region of the suction surface that is not covered by the workpiece, and the elastic member contacts the side surface of the workpiece and the covering member of another cover;
The jig is characterized in that when the workpiece is processed while being sucked by the suction surface, the entire area is covered by the plurality of covers . The jig described in claim 1, characterized in that the thickness of the covering member and the elastic member is less than the thickness of the workpiece. The jig described in claim 1 or 2, characterized in that the elastic member is a sponge with liquid absorption properties. A method for machining a workpiece, comprising: using a jig to suction-hold a workpiece, the workpiece including a first surface, a second surface, and a side surface connected to the first surface and the second surface, on a suction surface of a chuck table, and machining the workpiece;
the jig includes a plurality of covers including a covering member and an elastic member that comes into contact with the side surface of the workpiece and deforms to follow the shape of the side surface of the workpiece;
a placing step of placing the workpiece on the suction surface;
a holding step of arranging each of the plurality of covers so that the covering member contacts an exposed region of the suction surface that is not covered by the workpiece and the elastic member contacts the side surface of the workpiece and the covering member of another cover , and applying a suction force to the suction surface with the workpiece and the plurality of covers covering the suction surface, thereby suction-holding the workpiece and the plurality of covers on the chuck table;
a processing step of processing the workpiece while the workpiece is sucked by the suction surface and the entire area is covered by the plurality of covers . the thickness of the covering member and the thickness of the elastic member are less than the thickness of the workpiece;
In the placing step, the workpiece is placed on the suction surface so that the first surface of the workpiece is exposed and the second surface of the workpiece faces the suction surface;
5. The method for processing a workpiece according to claim 4, wherein in the processing step, the entire first surface side of the workpiece is ground with a grinding wheel. the elastic member is a sponge having liquid absorption properties,
6. The method for machining a workpiece according to claim 4, wherein in the machining step, the workpiece is machined while a machining fluid is supplied to the workpiece and the elastic member.