JP2024040571A - grinding wheel - Google Patents

Abstract

To provide a grinding wheel facilitating easy confirmation of a state inside the grinding wheel during grinding a workpiece.SOLUTION: The grinding wheel for grinding a workpiece includes: an annular wheel base; and a plurality of grinding stones provided on one surface of the wheel base; wherein the wheel base is made of a transparent material. The grinding wheel is characterized in that the wheel base is made of a transparent material, which, when this grinding wheel is used, facilitates confirmation of a state inside the grinding wheel during grinding a workpiece, for example, an amount of a grinding fluid supplied to a grinding point.SELECTED DRAWING: Figure 1

Description

The present invention relates to a grinding wheel for grinding a workpiece.

2. Description of the Related Art Device chips such as ICs (Integrated Circuits) are essential components in various electronic devices such as mobile phones and personal computers. Such chips are manufactured, for example, by dividing a workpiece, such as a wafer, on which a plurality of devices are formed on the front side along boundaries between the plurality of devices.

Further, the workpiece is often thinned before being divided in order to make the chip smaller and lighter. A method for thinning the workpiece includes grinding the back side of the workpiece using a grinding device. A grinding device generally includes a chuck table that holds the surface side of a workpiece, and a spindle that is provided above the chuck table and has a grinding wheel attached to its lower end.

A grinding wheel generally includes an annular wheel base having one surface with an annular groove formed therein, and a plurality of grinding wheels each having one end secured in the groove. Furthermore, a flow path may be formed inside the grinding wheel to supply grinding fluid such as pure water to the contact interface (processing point) between multiple grinding wheels and the workpiece (for example, (See Reference 1).

In the grinding device, for example, a grinding fluid is supplied to the back side of the workpiece while both the chuck table that holds the front side of the workpiece and the grinding wheel attached to the lower end of the spindle are rotating. At the same time, a plurality of grinding wheels are brought into contact with the back surface of the workpiece. As a result, the back side of the workpiece is ground while the grinding fluid is supplied to the processing point, thereby thinning the workpiece.

Japanese Patent Application Publication No. 2014-124690

The wheel base of a grinding wheel is generally made of a metal material such as aluminum. Therefore, while grinding a workpiece, it is difficult to check the inside of the grinding wheel, for example, the amount of grinding fluid supplied to the processing point. In view of this point, it is an object of the present invention to provide a grinding wheel that makes it easy to check the inside of the grinding wheel while grinding a workpiece.

According to the present invention, a grinding wheel for grinding a workpiece includes one surface, an opposite surface that is the back surface of the one surface, and an inner surface and an outer surface connecting the one surface and the opposite surface. The grinding wheel is provided with a grinding wheel made of a transparent material, and the wheel base is provided with a grinding wheel made of a transparent material.

Furthermore, in the present invention, it is preferable that a metal layer is provided on the opposite surface.

Further, in the present invention, it is preferable that a screw hole for screwing a bolt is formed on the opposite surface, and the side wall of the screw hole is made of a metal material.

Further, in the present invention, it is preferable that the inner surface includes a first sloped portion, and the outer surface includes a second sloped portion parallel to the first sloped portion in a longitudinal section.

In the grinding wheel of the present invention, the wheel base is made of a transparent material. Therefore, when using this grinding wheel, it is easy to check the inside of the grinding wheel while grinding a workpiece, for example, the amount of grinding fluid supplied to a processing point.

FIG. 1(A) is a top view schematically showing an example of a grinding wheel, FIG. 1(B) is a cross-sectional view schematically showing an example of a grinding wheel, and FIG. 1(C) is a top view schematically showing an example of a grinding wheel. FIG. 2 is a bottom view schematically showing an example of a wheel. FIG. 2 is a partially sectional side view schematically showing how a workpiece is ground in the grinding device. FIG. 3 is a cross-sectional view schematically showing another example of the grinding wheel. FIG. 4 is a cross-sectional view schematically showing still another example of the grinding wheel. FIG. 5 is a cross-sectional view schematically showing still another example of the grinding wheel.

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1(A) is a top view schematically showing an example of a grinding wheel, FIG. 1(B) is a cross-sectional view schematically showing an example of a grinding wheel, and FIG. 1(C) is a top view schematically showing an example of a grinding wheel. FIG. 2 is a bottom view schematically showing an example of a wheel.

The grinding wheel 2 shown in FIGS. 1(A), 1(B), and 1(C) has an annular wheel base 4 made of a transparent material. Note that examples of the transparent material include acrylic resin and transparent ceramics.

The wheel base 4 has a generally flat upper surface (opposite surface) 4a and a lower surface (one surface) 4b having a narrower width (length along the radial direction of the wheel base 4) than the upper surface 4a. Moreover, the upper surface 4a and the lower surface 4b are connected via the inner surface 4c and the outer surface 4d.

This inner surface 4c includes an inclined portion having a shape corresponding to the side surface of a truncated cone. Further, the outer surface 4d has a shape corresponding to the side surface of a cylinder. Furthermore, a plurality of screw holes 4e are formed in the upper surface 4a at approximately equal angular intervals along the circumferential direction of the wheel base 4.

The grinding wheel 2 is attached to the tip (lower end) of a spindle provided in the grinding device using bolts that are screwed into each of the plurality of screw holes 4e. Further, on the lower surface 4b of the wheel base 4, an annular groove 4f having a rectangular cross section is formed.

The width of the groove 4f (the length along the radial direction of the wheel base 4) is, for example, 2.0 mm to 5.0 mm, and the depth is, for example, 2 mm. The upper end side (one end side) of a plurality of grinding wheels 6 are inserted into the groove 4f at approximately equal angular intervals along the circumferential direction of the wheel base 4.

The grinding wheel 6 has the shape of a rectangular parallelepiped curved with a curvature approximately equal to the curvature of the groove 4f. Further, the grinding wheel 6 includes a binder such as vitrified or resinoid, and abrasive grains such as diamond dispersed in the binder. Further, the width of the grinding wheel 6 (the length along the radial direction of the wheel base 4) is, for example, 1.6 mm to 4.0 mm.

Further, the lower end surfaces (grinding surfaces) of the plurality of grinding wheels 6 are located on approximately the same plane. Further, the plurality of grinding wheels 6 are fixed to the groove 4f via a hardened adhesive 8. The cured adhesive 8 is obtained, for example, by drying a highly viscous liquid adhesive whose main component is resin.

This liquid adhesive does not drip downward from the groove 4f when the groove 4f faces downward, and when the upper end side of the plurality of grinding wheels 6 is inserted into the groove 4f in this state, the plurality of grinding wheels 6 The viscosity is adjusted to a level that will hold the product without causing it to fall.

For example, the viscosity of this liquid adhesive at room temperature is 20 Pa·S to 100 Pa·S. Further, this liquid adhesive may contain a filler to increase viscosity. Examples of the filler material include materials containing alumina (Al ₂ O ₃ ) as a main component, such as white alundum (WA).

FIG. 2 is a partially sectional side view schematically showing a state in which a workpiece is ground in a grinding device including a spindle attached to the tip (lower end) of the grinding wheel 2. As shown in FIG. Note that in FIG. 2, the line of sight of the operator is indicated by an arrow for convenience.

The grinding apparatus 10 shown in FIG. 2 has a chuck table 12 that can hold a workpiece 11. The chuck table 12 has a disc-shaped frame 14 made of ceramics or the like, for example. This frame body 14 has a disk-shaped bottom wall 14a and a cylindrical side wall 14b that stands upright from the outer periphery of the bottom wall 14a.

That is, a disc-shaped recess defined by the bottom wall 14a and the side walls 14b is formed on the upper surface side of the frame 14. A disc-shaped porous plate 16 made of porous ceramics or the like is fixed in this recess.

Further, the upper surface of the side wall 14b of the frame body 14 and the upper surface of the porous plate 16 have a shape corresponding to the side surface of a cone, and function as a holding surface for the chuck table 12. Further, a channel 14c is formed in the bottom wall 14a, which opens at the bottom surface of the recess and passes through the bottom wall 14a.

Further, the flow path 14c is connected to a suction source (not shown) such as an ejector via a valve or the like. When the suction source operates with the workpiece 11 placed on the holding surface of the chuck table 12, the workpiece 11 is sucked and held on the chuck table 12.

Further, the chuck table 12 is connected to a rotation mechanism (not shown) including a servo motor, a pulley, and the like. When this rotation mechanism operates, the chuck table 12 rotates with a straight line passing through the center of the holding surface of the chuck table 12 as the rotation axis.

Furthermore, the chuck table 12 is connected to a tilt adjustment mechanism (not shown). This tilt adjustment mechanism includes two movable shafts and one fixed shaft that are arranged at approximately equal angular intervals along the circumferential direction of the chuck table 12. Then, when at least one of the two movable axes partially moves the chuck table 12 up and down, the inclination of the rotation axis of the chuck table 12 is adjusted.

A spindle 18 is provided above the chuck table 12 and has a base end (upper end) connected to a servo motor (not shown). When this servo motor operates, the spindle rotates with a straight line along the direction in which the spindle 18 extends as the rotation axis. Further, the tip (lower end) of the spindle 18 has a disc-like shape having a diameter approximately equal to the outer diameter of the grinding wheel 2, and functions as a mount 20 on which the grinding wheel 2 is mounted.

Further, a plurality of through holes (not shown) are formed in the outer peripheral portion of the mount 20 at intervals of approximately the same angle as the plurality of screw holes 4e formed in the upper surface 4a of the wheel base 4. The grinding wheel 2 is mounted on the mount 20 by inserting bolts 22 into each through hole and screwing each bolt 22 into the screw hole 4e.

A grinding fluid supply unit 24 is provided below the grinding wheel 2 . This grinding fluid supply unit 24 includes, for example, a nozzle 26 located inside the grinding wheel 2 in plan view, and a pump (not shown) that supplies liquid (grinding fluid) such as pure water to the nozzle 26.

When this pump operates, the grinding fluid is supplied from the nozzle 26 to the upper surface of the workpiece 11 held by the chuck table 12. Further, in the grinding device 10, the grinding liquid may be supplied through a flow path formed in the grinding wheel 2 instead of or in addition to the nozzle 26.

Further, the spindle 18 is connected to a lifting mechanism (not shown) including a ball screw, a stepping motor, and the like. When this elevating mechanism operates, the spindle 18, mount 20, and grinding wheel 2 move up and down.

When grinding the upper surface side of the workpiece 11 using the chuck table 12, first, the rotation mechanism connected to the chuck table 12 and the base end of the spindle 18 are connected to the chuck table 12 so as to rotate both the chuck table 12 and the grinding wheel 2. Operate the servo motor connected to the section.

Next, while keeping both the chuck table 12 and the grinding wheel 2 rotating, the lifting mechanism connected to the spindle 18 is operated so as to bring the plurality of grinding wheels 6 into contact with the workpiece 11. That is, while both the chuck table 12 and the grinding wheel 2 are kept rotating, the grinding wheel 2 is lowered until the workpiece 11 and the plurality of grinding wheels 6 come into contact with each other.

Further, the grinding liquid supply unit 24 is operated so that the grinding liquid L is supplied to the workpiece 11 immediately before the workpiece 11 and the plurality of grinding wheels 6 come into contact with each other. As a result, the upper surface side of the workpiece 11 is ground while the grinding liquid L is supplied to the contact interface (processing point) between the workpiece 11 and the plurality of grinding wheels 6.

Here, in the grinding wheel 2, the wheel base 4 is made of a transparent material. Therefore, when using this grinding wheel 2, it becomes easy to check the inside state of the grinding wheel 2 while grinding the workpiece 11, for example, the amount of grinding fluid L supplied to the processing point. .

Note that the grinding wheel 2 is one aspect of the present invention, and the content of the present invention is not limited to the grinding wheel 2. 3 to 5 are cross-sectional views schematically showing other examples of the grinding wheel of the present invention. Note that in FIG. 5, the line of sight of the operator is indicated by an arrow for convenience.

The grinding wheel 28 shown in FIG. 3 has the same structure as the grinding wheel 2, except that an annular metal layer 30 is provided on the upper surface 4a of the wheel base 4. This metal layer 30 is made of a metal material having higher strength than the wheel base 4. Further, a plurality of through holes (not shown) are formed in the outer peripheral portion of the metal layer 30 so as to overlap with a plurality of screw holes 4e formed in the upper surface 4a of the wheel base 4.

Since this metal layer 30 has higher strength than the wheel base 4, more burrs occur on the upper surface of the grinding wheel 28 (the upper surface of the metal layer 30) than on the upper surface of the grinding wheel 2 (the upper surface 4a of the wheel base 4). It's hard to do. Therefore, when the grinding wheel 28 is attached to the tip (lower end) of the spindle 18, problems are less likely to occur than when the grinding wheel 2 is attached.

The grinding wheel 32 shown in FIG. 4 is capable of grinding, except that a side wall 34 defining a screw hole 4e formed in the upper surface 4a of the wheel base 4 is embedded in the upper surface 4a side of the wheel base 4. It has a similar structure to wheel 2. This side wall 34 is made of a metal material having higher strength than the wheel base 4.

Since this side wall 34 has higher strength than the wheel base 4, in the grinding wheel 32, compared to the grinding wheels 2 and 28, when a strong force is applied to the bolt 22 due to grinding of the workpiece 11, etc. Even so, the bolt 22 is difficult to separate from the wheel base 4. Therefore, when the workpiece 11 is ground using the grinding wheel 32, problems are less likely to occur compared to when the grinding is performed using the grinding wheels 2 and 28.

The grinding wheel 36 shown in FIG. 5 has a point that the outer surface 4g of the wheel base 4 includes an inclined portion (second inclined portion) parallel to the inclined portion (first inclined portion) included in the inner surface 4c in the longitudinal section. It has the same structure as the grinding wheel 2 except for.

In the grinding wheel 36, the width of the wheel base in the direction along the line of sight of the operator tends to be constant. Therefore, when the grinding wheel 36 is attached to the tip (lower end) of the spindle 18, it is easier to check the inside state compared to when the grinding wheels 2, 28, and 32 are attached. .

In addition, the structure, method, etc. according to the embodiments described above can be modified and implemented as appropriate without departing from the scope of the objective of the present invention.

2: Grinding wheel 4: Wheel base (4a: upper surface (opposite surface), 4b: lower surface (one surface), 4c inner surface)
(4d: outer surface, 4e: screw hole, 4f: groove, 4g: outer surface)
6: Grinding wheel 8: Adhesive 10: Grinding device 12: Chuck table 14: Frame (14a: bottom wall, 14b: side wall, 14c: channel)
16: Porous plate 18: Spindle 20: Mount 22: Bolt 24: Grinding fluid supply unit 26: Nozzle 28: Grinding wheel 30: Metal layer 32: Grinding wheel 34: Side wall 36: Grinding wheel

Claims (4)

A grinding wheel for grinding a workpiece,
An annular wheel base including one surface, an opposite surface that is the back surface of the one surface, and an inner surface and an outer surface connecting the one surface and the opposite surface;
A plurality of grinding wheels provided on the one surface,
The wheel base is a grinding wheel made of transparent material. Grinding wheel according to claim 1, wherein the opposite side is provided with a metal layer. A screw hole for screwing a bolt is formed on the opposite surface,
The grinding wheel according to claim 1, wherein the side wall of the screw hole is made of a metal material. the inner surface includes a first slope;
The grinding wheel according to any one of claims 1 to 3, wherein the outer surface includes a second sloped portion parallel to the first sloped portion in longitudinal section.

Images