JP2023077114A - Grinding device - Google Patents

Abstract

To provide a grinding device capable of efficiently cleaning a workpiece held on a chuck table and suppressing scattering of cleaning water around.SOLUTION: This grinding device for grinding the surface of a workpiece comprises: a grinding unit provided with a grinding wheel having an annularly disposed grindstone at the tip of a spindle; a chuck table having a holding surface on which the workpiece can be held; a process-feeding mechanism for moving the chuck table and the grinding unit relative to each other in a process-feeding direction; and a nozzle which is connected to a liquid supply source and a gas supply source and through which grinding water can be supplied to the workpiece held on the chuck table. Through the nozzle, water supplied from the liquid supply source and a mixed fluid mixing the water supplied from the liquid supply source and a gas supplied from the gas supply source can be switched to be injected.SELECTED DRAWING: Figure 1

Description

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

In the process of manufacturing device chips, a wafer is used in which devices are formed in a plurality of areas partitioned by a plurality of streets (division lines) that intersect with each other. A plurality of device chips each having a device is obtained by dividing the wafer along the streets. Device chips are incorporated into various electronic devices such as mobile phones and personal computers.

In recent years, along with the miniaturization of electronic devices, there is a demand for thinner device chips. Therefore, a process of thinning the wafer by grinding it with a grinding machine may be carried out before splitting. A grinding apparatus includes a chuck table including a holding surface for holding a workpiece, and a grinding unit for grinding the workpiece. The grinding unit has a spindle, and a grinding wheel containing a plurality of grinding wheels is attached to the tip of the spindle.

When grinding a workpiece such as a wafer using a grinding device, the positional relationship between the chuck table and the grinding unit is adjusted so that the center of the workpiece held by the chuck table overlaps the track of the grinding wheel. be done. Then, while rotating the chuck table and the grinding wheel, the grinding wheel is lowered along the processing feed direction (vertical direction) substantially parallel to the rotation axis of the spindle. As a result, the lower surface of the grinding wheel comes into contact with the upper surface of the workpiece, and the workpiece is ground. Such a grinding method is called infeed grinding.

On the other hand, a grinding method called creep feed grinding is sometimes used for grinding the workpiece. In creep feed grinding, the positional relationship between the chuck table and the grinding unit is adjusted so that the grinding wheel is positioned outside the workpiece and the lower surface of the grinding wheel is positioned below the upper surface of the workpiece. be. Then, while rotating the grinding wheel, the chuck table is moved along the processing feed direction (horizontal direction) substantially perpendicular to the rotation axis of the spindle. As a result, the side surface of the grinding wheel comes into contact with the workpiece, and the upper part of the workpiece is ground (see Patent Document 1).

When the grinding wheel is in contact with the workpiece and the workpiece is ground, the grinding wheel and the workpiece are worn and debris is produced. In addition, processing heat is generated at the contact point between the grinding wheel and the workpiece. Therefore, the grinding apparatus is equipped with a nozzle for injecting a liquid called grinding water near the contact point between the grinding wheel and the workpiece, and by injecting the grinding water from the nozzle to the vicinity of the contact point, the grinding waste is removed. and removes processing heat.

Further, the grinding apparatus has a box-shaped cover member called a water case for preventing the grinding water sprayed onto the workpiece or the like from splashing around. The water case covers the area where grinding of the workpiece is performed. In the grinding apparatus, a chuck table holding a workpiece is sent inside the water case, the workpiece is ground inside the water case, and then the chuck table is sent outside the water case.

JP-A-2005-28550

If the grinding water that has taken in the machining waste remains on the surface of the workpiece, the workpiece may dry outside the water case and the machining debris may adhere to the workpiece. Therefore, it is conceivable that the grinding apparatus is provided with a nozzle for spraying cleaning water on the workpiece held by the chuck table in the vicinity of the outer edge in the water case. In this case, the workpiece can be cleaned by injecting cleaning water from the nozzle onto the workpiece when the chuck table advances from the inside of the water case to the outside.

However, it is not easy to dispose nozzles capable of injecting cleansing water into the limited space inside the water case. In addition, installing the nozzle itself is costly. Also, the water case is open at least along the path along which the chuck table moves. Since the workpiece held by the chuck table is sprayed with the cleaning water while advancing from the water case to the outside, it is different from the grinding water supplied to the area steadily covered by the water case. Water easily scatters outside.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a grinding apparatus capable of efficiently cleaning a workpiece held by a chuck table while suppressing scattering of cleaning water around the workpiece. do.

According to one aspect of the present invention, there is provided a grinding apparatus for grinding the surface of a workpiece, comprising: a grinding unit having a grinding wheel having grinding wheels arranged in an annular shape at the tip of a spindle; a chuck table having a holding surface capable of being held; a machining feed mechanism for relatively moving the chuck table and the grinding unit in the machining feed direction; a nozzle capable of supplying a fluid to the held workpiece, the nozzle comprising water supplied as the fluid from the liquid supply, water supplied from the liquid supply and the gas supply. There is provided a grinding apparatus characterized by being able to switch between and jet a mixed fluid of gas supplied from .

Preferably, the machining feed direction is parallel to the holding surface. Alternatively, the processing feed direction is a direction perpendicular to the holding surface.

Preferably, while the workpiece held by the chuck table is being ground by the grinding unit, grinding water is jetted as the fluid from the nozzle so that the workpiece is ground by the grinding unit. The mixed fluid is jetted from the nozzle toward the holding surface when the workpiece is not being held to wash the workpiece or the holding surface.

More preferably, the nozzle is further capable of injecting the gas supplied from the gas supply, the gas being ejected from the nozzle when the workpiece held by the chuck table is not being ground by the grinding unit. A gas is injected onto the workpiece to dry the workpiece.

Also, preferably, the nozzle is arranged outside the grinding unit. Also, preferably, the nozzle has a jetting port arranged along a direction intersecting with the processing feed direction.

Further preferably, the apparatus further comprises an elevating mechanism for elevating the grinding unit, operating the elevating mechanism to lower the grinding unit to move the grinding wheel in front of the nozzle, and from the nozzle to the grinding wheel. The grinding wheel can be cleaned by injecting the liquid or the mixed fluid, and the grinding wheel can be dried by injecting the gas from the nozzle to the grinding wheel.

A grinding apparatus according to one aspect of the present invention includes a nozzle coupled to a liquid supply and a gas supply and capable of supplying grinding water to a workpiece held by a chuck table. And this nozzle can switch and jet water and the mixed fluid of water and gas. Therefore, when the workpiece is ground, grinding water can be supplied to the workpiece or the like by injecting the grinding water from the nozzle. Further, after the grinding of the work piece is completed, the work piece can be washed on the spot by supplying the mixed fluid of water and gas to the work piece.

In this case, there is no need to newly provide a nozzle only for injecting the mixed fluid in addition to the nozzle for supplying the grinding water, and no extra cost is incurred. Also, the space inside the water case is not compressed. Further, the mixed fluid can be jetted from the nozzle to the workpiece in the area where grinding is performed in the water case. That is, since the mixed fluid is jetted in a region that is steadily covered with the water case, the water contained in the mixed fluid is less likely to scatter outside the water case.

Therefore, according to one aspect of the present invention, there is provided a grinding apparatus capable of efficiently cleaning a workpiece held by a chuck table and suppressing splashing of cleaning water to the surroundings.

It is a perspective view which shows a grinding apparatus typically. It is a cross-sectional side view which shows a part of grinding apparatus typically. FIG. 4 is a side view schematically showing a chuck table and a grinding unit before grinding; FIG. 4 is a side view schematically showing a grinding unit that grinds a workpiece; FIG. 5A is a side view schematically showing a nozzle that injects a mixed fluid onto a workpiece, and FIG. 5B schematically shows a nozzle that injects a gas onto the workpiece. is a side view shown in FIG. FIG. 6A is a side view schematically showing a nozzle that injects the mixed fluid onto the holding surface of the chuck table, and FIG. 6B shows the nozzle that injects the mixed fluid onto the grinding wheel. It is a side view shown typically.

An embodiment according to one aspect of the present invention will be described below with reference to the accompanying drawings. First, a configuration example of a grinding apparatus according to this embodiment will be described. In particular, a grinding apparatus capable of performing creep feed grinding on a workpiece will be described as an example, but the grinding apparatus according to the present embodiment is not limited to this, and a grinding apparatus capable of performing infeed grinding on a workpiece will also be used. good.

FIG. 1 is a perspective view showing a grinding device 2. FIG. In FIG. 1, the X-axis direction (processing feed direction, first horizontal direction, front-rear direction) and the Y-axis direction (second horizontal direction, left-right direction) are perpendicular to each other. Also, the Z-axis direction (vertical direction, vertical 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 component constituting the grinding device 2 . The upper surface of the base 4 is provided with a rectangular parallelepiped opening 4a whose longitudinal direction is along the X-axis direction. A rectangular parallelepiped support structure 6 is provided along the Z-axis direction at the rear end portion of the upper surface side of the base 4 .

A chuck table (holding table) 8 for holding a workpiece to be machined by the grinding device 2 is provided inside the opening 4a. The upper surface of the chuck table 8 is a flat surface substantially parallel to the horizontal plane (XY plane), and constitutes a holding surface 8a for holding the workpiece. A processing feed mechanism (moving unit) 10 is connected to the chuck table 8 to move the chuck table 8 along the processing feed direction (X-axis direction).

FIG. 2 is a partial cross-sectional side view showing the grinding device 2. As shown in FIG. 2, illustration of some components of the grinding device 2 is omitted. As shown in FIG. 2, the processing feed mechanism 10 is provided inside the opening 4a of the base 4. As shown in FIG.

The processing feed mechanism 10 includes a flat moving plate 12 that supports the chuck table 8 . A nut portion 14 is provided on the back side (lower side) of the moving plate 12 . A ball screw 16 arranged along the X-axis direction is screwed into the nut portion 14 . A pulse motor 18 for rotating the ball screw 16 is connected to the end of the ball screw 16 . A chuck table 8 is mounted on the surface side (upper surface side) of the moving plate 12 . When the ball screw 16 is rotated by the pulse motor 18, the chuck table 8 and the moving plate 12 move along the X-axis direction.

The grinding apparatus 2 may move a grinding unit 36, which will be described later, along the X-axis direction instead of the chuck table 8. FIG. In other words, the grinding device 2 has a processing feed mechanism that relatively moves the chuck table 8 and the grinding unit 36 in the processing feed direction (X-axis direction).

Further, the chuck table 8 is connected to a rotary drive source (not shown) such as a motor that rotates the chuck table 8 around a rotation axis that is substantially perpendicular to the holding surface 8a (a rotation axis that is substantially parallel to the Z-axis direction). may be In this case, the rotation axis of the chuck table 8 is set along the direction perpendicular to the holding surface 8a.

As shown in FIG. 1, a table cover 20 surrounding the chuck table 8 is provided around the chuck table 8 . Accordion-shaped dust and drip proof covers 22 that are extendable along the X-axis direction are provided in front and rear of the table cover 20 . The table cover 20 and the dust/splash proof cover 22 cover the components of the processing feed mechanism 10 provided inside the opening 4a.

A lifting mechanism (moving unit) 24 is provided on the front side of the support structure 6 . The lifting mechanism 24 includes a pair of guide rails 26 arranged along the Z-axis direction. A flat plate-like moving plate 28 is attached to the pair of guide rails 26 so as to be slidable along the guide rails 26 .

A nut portion (not shown) is provided on the back side (rear side) of the moving plate 28 . A ball screw 30 arranged along the Z-axis direction between the pair of guide rails 26 is screwed into the nut portion. A pulse motor 32 for rotating the ball screw 30 is connected to the end of the ball screw 30 . When the ball screw 30 is rotated by the pulse motor 32, the moving plate 28 moves (lifts) along the guide rail 26 in the Z-axis direction.

A support member 34 that protrudes forward from the surface (front surface) of the moving plate 28 is fixed to the moving plate 28 . The support member 34 supports a grinding unit 36 that grinds the workpiece 11 . Grinding unit 36 includes a cylindrical housing 38 supported by support member 34 . Further, the housing 38 accommodates a columnar spindle 40 arranged generally along the Z-axis direction.

A tip (lower end) of the spindle 40 protrudes downward from the lower surface of the housing 38 . A disk-shaped mount 42 made of metal or the like is fixed to the tip of the spindle 40 . A base end (upper end) of the spindle 40 is connected to a rotation drive source (not shown) such as a motor for rotating the spindle 40 .

An annular grinding wheel 44 for grinding the workpiece 11 is attached to the lower surface of the mount 42 . For example, grinding wheel 44 is secured to mount 42 by fasteners (not shown) such as bolts. A grinding wheel 44 is thereby attached to the distal end of the spindle 40 via the mount 42 .

Grinding wheel 44 includes an annular wheel base 46 and a plurality of grinding wheels 48 fixed to wheel base 46 . The wheel base 46 is made of metal such as stainless steel or aluminum, resin, or the like, and is formed to have approximately the same diameter as the mount 42 . A plurality of grinding wheels 48 each having, for example, a rectangular parallelepiped shape are arranged on the lower surface side of the wheel base 46 along the outer peripheral edge of the wheel base 46 at approximately equal intervals.

The grinding wheel 48 includes abrasive grains made of diamond, cBN (cubic boron nitride), or the like, and a binding material (bonding material) that fixes the abrasive grains. A metal bond, a resin bond, a vitrified bond, or the like can be used as the binder. However, the material, shape, structure, size, etc. of the grinding wheel 48 are not limited, and the number of grinding wheels 48 fixed to the wheel base 46 can be set arbitrarily.

Grinding wheel 44 rotates around a rotation axis generally parallel to the Z-axis direction by power transmitted from a rotational drive source via spindle 40 and mount 42 . That is, the rotation axis of the grinding wheel 44 is set along a direction parallel to the rotation axis of the spindle 40 .

A columnar nozzle 50 for supplying a liquid (grinding water) such as pure water to the grinding unit 36 is provided in front of the grinding unit 36 . The nozzle 50 is positioned above the opening 4 a of the base 4 so as to overlap the moving path of the chuck table 8 .

The nozzle 50 is composed of, for example, a pipe, a tube, or the like having a length approximately equal to the diameter of the holding surface 8a of the chuck table 8, and extends generally in the width direction (Y-axis direction) of the opening 4a (the direction intersecting the processing feed direction). ). However, the nozzle 50 does not have to be strictly parallel to the Y-axis direction, nor does it have to be linear. The nozzle 50 may be along a direction that does not coincide with the Y-axis direction, and may be curved or arcuate. In particular, if the shape of the nozzle 50 is an arc that surrounds a portion of the outer periphery of the mount 42 at equal distances, the fluid can be uniformly supplied to a predetermined area.

The nozzle 50 has an ejection port 50d on the side facing the grinding unit 36 . The ejection ports 50d are arranged at predetermined intervals along a direction intersecting the feed direction, and are configured by a plurality of fine holes or slits provided in the nozzle 50, for example. Alternatively, the ejection port 50d may be configured by a linear opening elongated in the direction intersecting the feed direction. The shape and configuration of the ejection port 50d are not particularly limited as long as the shape and configuration allow the fluid ejected from the ejection port 50d to travel in the air with a predetermined force. Also, the position of the ejection port 50d is not particularly limited.

The fluid is jetted in a belt-like or columnar shape from the jet port 50d. As a result, as will be described later with reference to FIG. 4, the grinding water 50a is supplied from the outside of the grinding wheel 44 to the region (processing region) where the workpiece 11 and the grinding wheel 48 come into contact. Then, the workpiece 11 and the grinding wheel 48 are cooled, and scraps (processing scraps) generated by the grinding process are washed away.

Moreover, there is no restriction on the installation method of the nozzle 50 . For example, the nozzle 50 is fixed to the upper surface of the base 4 or the grinding unit 36 via a predetermined connection member (not shown). Alternatively, the nozzle 50 need not be provided outside the grinding unit 36 and may have injection holes located in an area inside the annularly arranged grinding wheels 48 and facing the grinding wheels 48 . An example in which the nozzle 50 is arranged outside the grinding unit 36 will be described below.

Nozzle 50 is connected to liquid supply 54 via valve 52 . For example, an electromagnetic valve is used as the valve 52 . The liquid supply source 54 is, for example, factory equipment (liquid supply equipment) installed in a factory where the grinding apparatus 2 is installed, and supplies liquid such as pure water used as grinding water. The liquid supplied from the liquid supply source 54 may contain an additive or the like having a predetermined function. By controlling the opening/closing or opening degree of the valve 52, the flow rate of the liquid supplied from the liquid supply source 54 to the nozzle 50 is adjusted.

Nozzle 50 is also connected to gas supply 58 via valve 56 . For example, an electromagnetic valve is used as the valve 56 . The gas supply source 58 is, for example, factory equipment (gas supply equipment) such as a pump and a cylinder installed in the factory where the grinding device 2 is installed, and is a high-pressure gas such as air, dry air, nitrogen, rare gas, or the like. of gas. By controlling the opening/closing or opening degree of the valve 56, the flow rate of the gas supplied from the gas supply source 58 to the nozzle 50 is adjusted.

When only the valve 52 is opened, only the liquid supplied from the liquid supply source 54 to the nozzle 50 reaches the nozzle 50 and is ejected from the ejection port 50d. Also, when only the valve 56 is opened, only the gas supplied from the gas supply source 58 to the nozzle 50 reaches the nozzle 50 and is ejected from the ejection port 50d. Furthermore, when the valves 52 and 56 are opened, the mixed fluid of the liquid supplied from the liquid supply source 54 and the gas supplied from the gas supply source 58 reaches the nozzle 50, and the mixed fluid is ejected from the ejection port 50d. do.

Next, a specific example of a method of grinding a workpiece using the grinding device 2 will be described. As an example, creep feed grinding, in which the workpiece is ground by relatively moving the chuck table 8 and the grinding wheel 44 along the direction (X-axis direction) parallel to the holding surface 8a, will be described below.

First, the workpiece 11 is held by the chuck table 8 (holding step). FIG. 3 is a side view showing the chuck table 8 and grinding unit 36 in the holding step.

For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as silicon, and has a front surface 11a and a back surface 11b that are substantially parallel to each other. The workpiece 11 is partitioned into a plurality of rectangular regions by a plurality of streets (planned division lines) arranged in a lattice so as to intersect each other. In addition, devices such as IC (Integrated Circuit), LSI (Large Scale Integration), LED (Light Emitting Diode), MEMS (Micro Electro Mechanical Systems) devices, etc. formed.

A plurality of device chips each having a device are manufactured by dividing the workpiece 11 along the streets by cutting, laser processing, or the like. Further, if the workpiece 11 is ground and thinned by the grinding device 2 before the workpiece 11 is divided, a thinned device chip can be obtained.

However, the type, material, size, shape, structure, etc. of the workpiece 11 are not limited. For example, the workpiece 11 may be a disk-shaped wafer (substrate) made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), glass, ceramics, resin, metal, or the like. Moreover, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the device, and the workpiece 11 does not have to be formed with the device.

For example, the workpiece 11 is arranged on the chuck table 8 so that the front surface 11a side faces the holding surface 8a and the back surface 11b side is exposed upward. The holding surface 8a of the chuck table 8 is connected to a suction source (not shown) such as an ejector through a flow path (not shown) formed inside the chuck table 8, a valve (not shown), and the like. there is When the suction force (negative pressure) of the suction source is applied to the holding surface 8 a, the workpiece 11 is suction-held by the chuck table 8 .

Devices and the like formed on the surface 11a side of the workpiece 11 may be protected by attaching a protective member to the surface 11a side of the workpiece 11 . In this case, the workpiece 11 is held by the chuck table 8 via the protective member.

For example, as the protective member, a circular tape (protective tape) having approximately the same diameter as the workpiece 11 is used. The masking tape includes a film-like base material and an adhesive layer (glue layer) provided on the base material. The base material is made of resin such as polyolefin, polyvinyl chloride, polyethylene terephthalate. Also, the adhesive layer is made of an epoxy-based, acrylic-based, or rubber-based adhesive or the like. An ultraviolet curable resin that is cured by irradiation with ultraviolet rays can also be used for the adhesive layer.

Next, the workpiece 11 is ground by the grinding wheel 48 of the grinding wheel 44 (grinding step). In the grinding step, first, the workpiece 11 held by the chuck table 8 and the grinding wheel 48 are separated from each other in the processing feed direction (X-axis direction), and the lower surface of the grinding wheel 48 is the upper surface of the workpiece 11 . The positional relationship between the chuck table 8 and the grinding unit 36 is adjusted so that the chuck table 8 and the grinding unit 36 are positioned below the (rear surface 11b) by a predetermined distance.

Specifically, the position of the chuck table 8 in the X-axis direction is adjusted so that the workpiece 11 is arranged in front of the grinding wheel 44 (on the left side of the paper surface in FIG. 3) without overlapping the grinding wheel 44. (see FIGS. 1 and 2). Also, the position of the grinding unit 36 in the Z-axis direction is adjusted by the lifting mechanism 24 (see FIG. 1) so that the lower surface of the grinding wheel 48 is positioned below the upper surface of the workpiece 11 . At this time, the difference ΔH in the height position (position in the Z-axis direction) between the upper surface of the workpiece 11 and the lower surface of the grinding wheel 48 is the amount of grinding of the workpiece 11 (the thickness of the workpiece 11 before and after grinding). difference).

Next, while rotating the grinding wheel 44, the chuck table 8 and the grinding unit 36 are relatively moved along the processing feed direction (X-axis direction), and the grinding wheel 48 moves the workpiece 11 from one end to the other end. Grind to the side. Specifically, first, by rotating the spindle 40 , the grinding wheel 44 is rotated around the rotation axis of the spindle 40 . As a result, each of the plurality of grinding wheels 48 rotates along an annular track (moving path). The number of revolutions of the grinding wheel 44 is set to, for example, 1000 rpm or more and 3000 rpm or less.

Then, while the grinding wheel 44 is rotating and the chuck table 8 is not rotating, the chuck table 8 is moved along the X-axis direction at a predetermined speed by the processing feed mechanism 10 (see FIGS. 1 and 2). Let As a result, the chuck table 8 and the grinding wheel 44 move relative to each other at a predetermined processing feed rate along the processing feed direction perpendicular to the rotating shaft of the spindle 40 and approach each other. The moving speed (processing feed speed) of the chuck table 8 is set to, for example, 1 mm/s or more and 20 mm/s or less.

FIG. 4 is a side view showing the grinding unit 36 for grinding one end of the workpiece 11. As shown in FIG. When the chuck table 8 moves and one end of the workpiece 11 (the front end of the workpiece 11 in the movement direction, the right edge of the paper surface in FIG. 4) reaches the track of the grinding wheel 48, the one end of the workpiece 11 is scraped off by the grinding wheel 48 .

As the chuck table 8 moves, each region of the workpiece 11 hits the grinding wheel 48 one after another, and the grinding of the workpiece 11 progresses. Then, the workpiece 11 is ground from one end side to the other end side by the grinding wheel 48, and the entire workpiece 11 is thinned.

Furthermore, the grinding of the workpiece 11 is repeated until the thickness of the workpiece 11 reaches the final target value (finished thickness). The number of creep feed grinding operations (the number of grinding steps performed) can be appropriately set according to the material of the workpiece 11, the amount of grinding, and the like.

While the workpiece 11 is being ground, the grinding water 50a such as pure water is supplied from the ejection port 50d of the nozzle 50 to the workpiece 11 and the grinding wheel . Grinding dust and processing heat generated when the workpiece 11 is ground by the grinding wheel 48 are removed by the grinding water 50a. However, if the grinding water 50a supplied to the workpiece 11 or the like scatters inside and outside the grinding device 2, it causes contamination. Prepare.

The water case, for example, covers the grinding area where the grinding wheel 48 hits the workpiece 11 to be ground, and substantially closes the internal space except for the movement path of the chuck table 8 . A workpiece 11 to be ground is placed on a chuck table 8 outside the water case, and carried into the water case while being held by the chuck table 8 to be ground. The workpiece 11 that has been completely ground is carried out of the water case while being held by the chuck table 8 .

The workpiece 11 held and ground by the chuck table 8 is washed (washing step). However, since the grinding water containing grinding dust remains on the back surface 11b side of the workpiece 11 immediately after grinding, if the grinding water dries before the workpiece 11 is washed outside the water case, the grinding dust will be removed. adheres to the back surface 11b. Therefore, it is conceivable to provide a cleaning unit inside the water case to clean the workpiece 11 . However, it is not easy to provide a cleaning unit in a limited internal space.

For example, it is conceivable to provide a cleaning nozzle at the outer edge of the inner space of the water case and supply cleaning water from the cleaning nozzle to the workpiece 11 when the chuck table 8 advances from the inner space to the outside. However, when the cleaning water is sprayed at the outer edge of the inner space of the water case, the cleaning water is likely to scatter outside through the opening of the water case, causing contamination. In particular, cleaning water composed of a mixed fluid of water and high-pressure air is likely to scatter. Moreover, it is costly to add and install a cleaning nozzle inside the water case.

Therefore, the grinding apparatus 2 according to the present embodiment cleans the workpiece 11 held on the chuck table 8 using the nozzle 50 capable of injecting water as the grinding water 50a into the grinding area. A procedure (cleaning step) for cleaning the workpiece 11 held on the chuck table 8 will be described. FIG. 5A includes a side view schematically showing the workpiece 11 being cleaned.

As shown in FIG. 5A, when the grinding of the workpiece 11 is completed, the elevating mechanism (moving unit) 24 is operated to raise the grinding unit 36. As shown in FIG. Then, the valve 52 and the valve 56 (see FIG. 1) are opened, and the mixed fluid 50b of the liquid such as water supplied from the liquid supply source 54 and the gas supplied from the gas supply source 58 is used as the washing water, and the ejection port of the nozzle 50 Inject from 50d. After that, the processing feed mechanism (moving unit) 10 is operated to reciprocate the chuck table 8 along the processing feed direction, and the mixed fluid 50b is jetted onto the back surface 11b of the workpiece 11 .

When the mixed fluid 50b is vigorously jetted onto the back surface 11b of the workpiece 11, the grinding water containing grinding dust is removed from the back surface 11b. Therefore, even if the workpiece 11 dries after that, the grinding dust will not adhere to the back surface 11b of the workpiece 11 . Then, the injection of the mixed fluid 50b from the nozzle 50 to the workpiece 11 is in the vicinity of the grinding area where the grinding is performed. Since the grinding area is sufficiently covered with the water case, even if the mixed fluid 50b with strong force is sprayed onto the workpiece 11, the water contained in the mixed fluid 50b is less likely to scatter outside the water case.

Further, in the case where creep feed grinding is carried out step by step by passing the workpiece 11 under the rotating grinding wheel 44 while the grinding unit 36 is sequentially lowered in the grinding device 2, the workpiece 11 is gradually ground at each stage of grinding. may be washed with the mixed fluid 50b. That is, the workpiece 11 is ground while the chuck table 8 is fed forward in the processing feed direction, and the mixed fluid 50b is jetted to the workpiece 11 while the chuck table 8 is fed in the reverse direction of the processing feed direction. Clean item 11. The grinding unit 36 is then lowered to carry out the next step.

When the work piece 11 is washed in this manner at each stage of the stepwise creep feed grinding, the grinding dust remaining on the back surface 11b of the work piece 11 is trapped between the grinding wheel 48 and the work piece 11. It is possible to avoid a situation in which the workpiece 11 is damaged due to Conventionally, the chuck table 8 has been reciprocated in the stepwise creep feed grinding, but in the grinding apparatus 2 according to the present embodiment, the workpiece 11 can be cleaned during this reciprocation. Therefore, the operation of the chuck table 8 does not increase, and the time required for grinding does not increase.

In addition, in the grinding apparatus 2 according to the present embodiment, the workpiece 11 can be cleaned efficiently at each stage of creep feed grinding without the workpiece 11 being sequentially carried out of the water case and cleaned. It is possible to grind with high quality while maintaining

Furthermore, using the nozzle 50, it is also possible to dry the cleaned work piece 11 (drying step). FIG. 5B includes a side view schematically showing the workpiece 11 being dried. In the drying step, only the valve 56 (see FIG. 1) is opened and the high-pressure gas 50c supplied from the gas supply source 58 is jetted from the nozzle 50d. After that, the processing feed mechanism (moving unit) 10 is operated to reciprocate the chuck table 8 along the processing feed direction, while injecting the gas 50c onto the back surface 11b of the workpiece 11 .

When the workpiece 11 is dried, the water contained in the mixed fluid 50b used for cleaning drips from the workpiece 11 when the workpiece 11 is carried out from the chuck table 8 outside the water case. not be a source of contamination. Moreover, it is not necessary to wash and dry the workpiece 11 outside the grinding apparatus 2 .

Summarizing the functions using the nozzle 50 of the grinding device 2 according to the present embodiment described so far, the grinding device 2 performs Water or the like is jetted from the nozzle 50 as grinding water.

Further, the grinding device 2 cleans the workpiece 11 by injecting the mixed fluid 50b from the nozzle 50 toward the holding surface 8a when the workpiece 11 is not ground by the grinding unit 36 . Furthermore, the grinding device 2 dries the workpiece 11 by injecting the gas 50c from the nozzle 50 to the workpiece 11 when the workpiece 11 held by the chuck table 8 is not ground by the grinding unit 36. .

In the grinding apparatus 2 according to the present embodiment, there is no need to newly provide a nozzle only for injecting the mixed fluid 50b in addition to the nozzle 50 for supplying grinding water, and no extra cost is incurred. Also, the space inside the water case is not compressed. According to one aspect of the present invention, there is provided a grinding apparatus 2 capable of efficiently cleaning the workpiece 11 held by the chuck table 8 and suppressing splashing of cleaning water to the surroundings.

In the above embodiment, the case where the fluids such as the grinding water 50a, the mixed fluid 50b, and the gas 50c jetted from the jet port 50d of the nozzle 50 is jetted onto the workpiece 11 held on the chuck table 8 has been described. , one aspect of the present invention is not limited to this. That is, the fluid ejected from the nozzle 50 may be supplied to the object of the workpiece 11 .

For example, the grinding device 2 may inject the mixed fluid 50b from the ejection port 50d of the nozzle 50 onto the holding surface 8a of the chuck table 8 that does not hold the workpiece 11 to clean the holding surface 8a. FIG. 6A is a side view schematically showing how the holding surface 8a of the chuck table 8 is cleaned.

When the grinding device 2 grinds the workpieces 11 one after another, grinding dust may accumulate on the outer peripheral portion of the holding surface 8 a that is not covered with the workpieces 11 . As the workpiece 11 is repeatedly carried in and out of the chuck table 8, the accumulated grinding dust may scatter toward the center of the holding surface 8a. In this case, grinding dust is sandwiched between the workpiece 11 and the holding surface 8a, and the workpiece 11 is held on the chuck table 8 in an inclined state. If the back surface 11b of the workpiece 11 is ground in this state, the back surface 11b is inclined inappropriately.

Therefore, periodic cleaning of the holding surface 8a of the chuck table 8 is required. The grinding apparatus 2 according to this embodiment can wash the holding surface 8 a by reciprocating the chuck table 8 by the processing feed mechanism 10 while injecting the mixed fluid 50 b from the nozzle 50 . Therefore, it is not necessary to provide a nozzle used only for cleaning the holding surface 8a of the chuck table 8. FIG.

Further, the grinding device 2 may jet the mixed fluid 50b from the ejection port 50d of the nozzle 50 to the grinding wheel 44 attached to the grinding unit 36 to wash the grinding wheel 44 . FIG. 6B is a side view schematically showing how the grinding wheel 44 is washed. In the grinding device 2 , the grinding wheel 48 is worn out while repeatedly grinding the workpiece 11 , so the grinding wheel 44 needs to be replaced periodically.

However, as grinding of the workpiece 11 is repeated, processing waste adheres between the plurality of grinding wheels 48 and on the wheel base 46 . In the process of removing the grinding wheel 44 with the adhering machining scraps from the grinding unit 36 and carrying it out of the grinding apparatus 2, machining scraps may drop off from the grinding wheel 44 and contaminate the inside and outside of the grinding apparatus 2.

Therefore, by washing the grinding wheel 44 with the mixed fluid 50b before carrying out the grinding wheel 44 from the grinding device 2, contamination due to falling off of processing waste when the used grinding wheel 44 is carried out from the grinding device 2 is suppressed. can.

When cleaning the grinding wheel 44 , the lifting mechanism (moving unit) 24 is operated to lower the grinding unit 36 and move the grinding wheel 44 in front of the nozzle 50 . The grinding wheel 44 can be cleaned by spraying the liquid or mixed fluid 50b supplied from the liquid supply source 54 to the grinding wheel 44 from the nozzle 50 . At this time, by rotating the spindle 40 to rotate the grinding wheel 44 or by operating the elevating mechanism 24 to repeatedly move the grinding wheel 44 up and down, the entire grinding wheel 44 is uniformly cleaned.

Furthermore, the grinding apparatus 2 can dry the grinding wheel 44 by injecting the gas 50c supplied from the gas supply source 58 to the grinding wheel 44 from the nozzle 50 after cleaning the grinding wheel 44 . In this case, the problem that the water contained in the mixed fluid 50b remains on the surface of the grinding wheel 44 and falls from the grinding wheel 44 when the grinding wheel 44 is carried out from the grinding apparatus 2 and becomes a contamination source is suppressed. be.

Further, in the above embodiment, the grinding apparatus 2 that performs creep feed grinding in which the processing feed direction is parallel to the holding surface 8a of the chuck table 8 has been described as an example, but one aspect of the present invention is limited to this. not. That is, the grinding apparatus according to one aspect of the present invention may be a grinding apparatus that performs in-feed grinding in which the processing feed direction is a direction perpendicular to the holding surface 8 a of the chuck table 8 .

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

REFERENCE SIGNS LIST 11 Workpiece 11a Front surface 11b Back surface 2 Grinding device 4 Base 4a Opening 6 Support structure 8 Chuck table 8a Holding surface 10 Processing feed mechanism 12 Moving plate 14 Nut portion 16, 30 Ball screw 18, 32 Pulse motor 20 Table cover 22 Dust protection Drip-proof cover 24 Lifting mechanism 26 Guide rail 28 Moving plate 34 Supporting member 36 Grinding unit 38 Housing 40 Spindle 42 Mount 44 Grinding wheel 46 Wheel base 48 Grinding wheel 50 Nozzle 50a Grinding water 50b Mixed fluid 50c Gas 50d Spout 52,56 valve 54 liquid supply 58 gas supply

Claims (8)

A grinding device for grinding the surface of a workpiece,
a grinding unit having a grinding wheel at the tip of a spindle with grinding wheels arranged in an annular shape;
a chuck table having a holding surface capable of holding the workpiece;
a processing feed mechanism that relatively moves the chuck table and the grinding unit in a processing feed direction;
a nozzle connected to a liquid supply and a gas supply and capable of supplying fluid to the workpiece held by the chuck table;
The nozzle is characterized in that the fluid can be switched between a liquid supplied from the liquid supply source and a mixed fluid of the liquid supplied from the liquid supply source and the gas supplied from the gas supply source. and grinding equipment. 2. The grinding apparatus according to claim 1, wherein said processing feed direction is parallel to said holding surface. 2. The grinding apparatus according to claim 1, wherein said processing feed direction is a direction perpendicular to said holding surface. Grinding water is jetted as the fluid from the nozzle while the workpiece held by the chuck table is being ground by the grinding unit;
2. When the workpiece is not ground by the grinding unit, the mixed fluid is jetted from the nozzle toward the holding surface to clean the workpiece or the holding surface. 4. The grinding apparatus according to any one of claims 3 to 4. the nozzle is further capable of injecting the gas supplied from the gas source;
4. The method of claim 1, wherein the gas is jetted from the nozzle to the workpiece to dry the workpiece when the workpiece held by the chuck table is not ground by the grinding unit. 5. The grinding device according to 4. 6. The grinding apparatus according to claim 1, wherein said nozzle is arranged outside said grinding unit. 7. The grinding apparatus according to claim 6, wherein said nozzle has an ejection port arranged along a direction intersecting said feed direction. further comprising an elevating mechanism for elevating the grinding unit,
The lifting mechanism is operated to lower the grinding unit to move the grinding wheel in front of the nozzle, and the nozzle can spray the liquid or the mixed fluid onto the grinding wheel to wash the grinding wheel. 8. A grinding apparatus according to claim 6 or 7, wherein the grinding wheel can be dried by injecting the gas from the nozzle to the grinding wheel.

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