TW202300288A - Machining apparatus removes grinding debris attached to machining chamber cover so as to clean machining chamber cover at wider range by comparing with a fluid injection from a nozzle - Google Patents

Abstract

Cleaning the machining chamber cover has a wider range by comparing with a fluid injection from a nozzle. A machining apparatus is provided and comprises: a chuck table holding a workpiece; a machining unit having a spindle and machining the workpiece attracted and held by the chuck table through a machining tool mounted on the lower end portion of the spindle; a machining chamber cover having a top plate and a side wall and covering the sides and the top direction of the chuck table and the machining tool; and a vibration imposing unit having a vibration element and imposing vibration to the side wall and the top plate of the machining chamber cover.

Description

Processing device

The present invention relates to a processing device, which has: a chuck table; a processing unit, which is equipped with a processing tool for processing a workpiece attracted and held by the chuck table; and a processing chamber cover, which covers the chuck table and the processing unit. tool.

Assembling component wafers in electronic devices such as mobile phones. For example, a component wafer is formed by setting a plurality of grid-shaped dividing lines (dicing lines) on the front surface and forming components such as IC (Integrated Circuit, integrated circuit) in each area divided by the plurality of dicing lines. After the back side of the wafer is ground, the wafer is divided along each dicing line to manufacture.

In grinding of a wafer, a grinding apparatus having a rough grinding unit and a finish grinding unit is used (for example, refer to Patent Document 1). Each of the rough grinding unit and the finish grinding unit has a cylindrical spindle housing.

A part of the columnar spindle is rotatably accommodated in the spindle housing. The lower end of the main shaft protrudes below the bottom of the main shaft housing, and an annular grinding wheel is mounted on the lower end of the main shaft.

A rough grinding wheel is installed on the lower end of the main shaft of the rough grinding unit, and a finishing wheel is installed on the lower end of the main shaft of the fine grinding unit. The back side of the wafer is thinned to a predetermined thickness through rough grinding and finish grinding.

A chuck table is arranged directly under the rough grinding unit, and another chuck table is arranged directly under the finish grinding unit. A chuck table and a rough grinding wheel, and another chuck table and a finish grinding wheel train are covered by the processing chamber cover (for example, refer patent document 2).

The processing chamber cover restricts the scattering range of grinding chips generated during grinding and mist formed by atomizing grinding water supplied during grinding. However, as a result of the processing chamber cover restricting the scattering of grinding chips, grinding water, etc., the grinding chips adhere to and accumulate on the inner surfaces of the top plate, side plate, etc. of the processing chamber cover.

If the accumulated grinding chips fall to the back of the wafer during grinding, the grinding accuracy will be adversely affected, and if they fall to the back of the wafer after grinding, the wafer will also be adversely affected in the processing steps after grinding. Influence. In order to prevent this problem, the inside of the processing chamber cover is cleaned.

For example, it is known that a plurality of nozzles are provided on the inner surface side of the top plate of the processing chamber cover, and a gas-liquid mixed fluid formed by spraying mixed water and air from each nozzle is known to clean the inside of the processing chamber cover (for example, refer to Patent Document 2 ). [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-288881 [Patent Document 2] Japanese Unexamined Patent Publication No. 2010-247272

[Problems to be Solved by the Invention] However, it is difficult to completely spread the gas-liquid mixed fluid inside the top plate and the side plate of the processing chamber cover. The present invention has been made in view of this problem, and an object thereof is to clean a wider range of the processing chamber cover than the fluid jet from the nozzle.

[Technical means to solve the problem] According to one aspect of the present invention, there is provided a processing device comprising: a chuck table holding an object to be processed; a processing unit having a main shaft, and a processing tool mounted on the lower end of the main shaft is clamped by the chuck. The processed object is sucked and held by the disc table for processing; the processing chamber cover has a top plate and side walls, and covers the sides and the top of the chuck table and the processing tool; and the vibration applying unit has a vibration element, and Vibration is applied to the side wall and the top plate of the processing chamber cover.

Preferably, the oscillating element has an ultrasonic oscillator. More preferably, the processing chamber cover is supported on the base supporting the processing unit through a buffer material.

[Efficacy of the invention] A processing device according to an aspect of the present invention includes an oscillation applying unit having an oscillation element. Vibration is applied to the side wall and ceiling constituting the processing chamber cover by the vibration applying unit, thereby removing the grinding chips adhering to the processing chamber cover. Therefore, a wider range of the processing chamber cover can be cleaned than the fluid jet from the nozzle.

Embodiments of one aspect of the present invention will be described with reference to the accompanying drawings. First, a grinding device (processing device) 2 according to a first embodiment will be described with reference to FIG. 1 . The grinding device 2 has a base 4 supporting each component.

Cassette mounting stands 6 a and 6 b are provided on the front side of the base 4 . For example, a cassette 8 a containing a wafer (processed object) 11 before grinding is placed on the cassette mounting table 6 a, and a cassette 8 b containing, for example, a wafer 11 after grinding is mounted on the cassette mounting table 6 b.

A wafer transfer robot 10 that is adjacent to the cassette mounting tables 6 a and 6 b and that transfers a wafer 11 is provided on the base 4 . Furthermore, a positioning table 12 for determining the position of the wafer 11 is provided behind the cassette mounting table 6a.

A base end portion of a loading arm 18 is provided behind the positioning table 12 . A first suction and holding unit for suctioning the wafer 11 by negative pressure is provided at the front end of the loading arm 18 .

The loading arm 18 carries the wafer 11 into the disk-shaped turntable 14 provided behind the base end of the loading arm 18 . The base end portion of the unloading arm 20 is provided laterally adjacent to the base end portion of the loading arm 18 .

A second suction and holding unit for suctioning the wafer 11 by negative pressure is provided at the front end of the unloading arm 20 . The unload arm 20 unloads the wafer 11 from the turntable 14 .

The turntable 14 is configured to be rotatable around a predetermined rotation axis. On the upper surface of the turntable 14 , three chuck stands 16 are arranged at substantially equal intervals along the circumferential direction of the turntable 14 .

The upper surface side of the turntable 14 is divided into three fan-shaped areas by a plurality of linear partition plates (not shown) arranged radially. The fan-shaped area closest to the respective base ends of the loading arm 18 and the unloading arm 20 serves as a loading/unloading area A for loading or unloading the wafer 11 to/from the turntable 14 .

The fan-shaped area that advances approximately 120 degrees clockwise from the loading and unloading area A in a plan view becomes the rough grinding area B for rough grinding of the wafer 11, and the fan-shaped area that advances approximately 120 degrees counterclockwise from the loading and unloading area A in a plan view It becomes the finish grinding area C where the finish grinding of the wafer 11 is performed.

A chuck table 16 is provided in each sector. The upper surface of the chuck table 16 functions as a holding surface 16 a for sucking and holding the wafer 11 . A rotary driving source (not shown) such as a motor for rotating the chuck table 16 around a predetermined rotation axis is provided at a lower portion of the chuck table 16 .

A wall portion 4 a is provided behind the turntable 14 . Ball screw type grinding feed mechanisms 22a, 22b are provided on the front surface of the wall portion 4a. The grinding feed mechanism 22 a moves a rough grinding unit (machining unit) 24 a in the Z-axis direction. The rough grinding unit 24a is supported by the base 4 through the grinding feeding mechanism 22a.

Directly below the rough grinding unit 24a corresponds to the rough grinding area B described above. The rough grinding unit 24 a has a cylindrical spindle housing 26 . Part of the cylindrical spindle 28 is rotatably housed inside the spindle housing 26 .

A rotational drive source 30 such as a motor is provided at an upper end portion of the main shaft 28 . The lower end of the main shaft 28 protrudes below the bottom of the main shaft housing 26 , and a rough grinding wheel (processing tool) 34 a is attached to the lower end of the main shaft 28 through a disc-shaped attachment 32 .

The rough grinding wheel 34a has an annular wheel base formed of metal such as aluminum alloy. On one side of the wheel base, a plurality of rough grinding stones each having a grinding tooth shape are arranged at approximately equal intervals along the circumferential direction of the wheel base.

The rough grinding unit 24a performs rough grinding (processing) on the back side of the wafer 11 sucked and held by the chuck table 16 arranged in the rough grinding area B. The side and upper side of the chuck table 16 and the rough grinding wheel 34a arranged in the rough grinding area B are covered by the rough grinding chamber cover 38 of the processing chamber cover 36 formed of metal such as stainless steel.

Like the grinding feed mechanism 22a, the grinding feed mechanism 22b moves the finish grinding unit (machining unit) 24b along the Z-axis direction. The finish grinding unit 24b is supported by the base 4 through the grinding feeding mechanism 22b. Directly below the finish grinding unit 24b corresponds to the finish grinding area C described above.

The fine grinding unit 24 b also has a spindle housing 26 , a spindle 28 , a rotary drive source 30 and a mount 32 . A finishing wheel (processing tool) 34b is attached to the lower end of the main shaft 28 of the finishing unit 24b through a mount 32 .

On the one surface side of the wheel base of the finishing wheel 34b, a plurality of finishing grindstones each having a grinding tooth shape are arranged at approximately equal intervals along the circumferential direction of the wheel base. The finishing grindstone has abrasive grains whose average particle size is smaller than that of the rough grinding grindstone; and a binder which fixes the abrasive grains.

The finish grinding unit 24 b performs finish grinding (processing) on the back side of the wafer 11 sucked and held by the chuck table 16 arranged in the finish grinding area C. The side and upper side of the chuck table 16 and the finishing wheel 34b disposed in the finishing area C are covered by the finishing chamber cover 40 constituting the processing chamber cover 36 .

Next, the machining chamber cover 36 (rough grinding chamber cover 38 and finish grinding chamber cover 40 ) will be described in more detail. FIG. 1 is a perspective view of the grinding device 2 with the processing chamber cover 36 removed, and FIG. 2 is a perspective view of the grinding device 2 with the processing chamber cover 36 installed.

As shown in FIG. 1 , the rough grinding chamber cover 38 has a boundary side wall 36a, a front side wall 38a, a rear side wall 38b, an outer side wall 38c, a top plate 38d, etc., and a predetermined space is formed by these components.

A cylindrical portion 38e surrounding the outer peripheral portion of the spindle housing 26 is provided on the upper surface of the top plate 38d. Furthermore, a door portion 38f for allowing an operator to enter and exit the interior of the rough grinding chamber cover 38 is provided on the top plate 38d near the cylindrical portion 38e.

The finishing chamber cover 40 similarly has a boundary side wall 36a, a front side wall 40a, a rear side wall 40b, an outer side wall 40c, a top plate 40d, etc., and forms a predetermined space by these components.

A cylindrical portion 40e surrounding the outer peripheral portion of the spindle housing 26 is provided on the upper surface of the top plate 40d. And the door part 40f for allowing an operator to enter and leave the inside of the finishing chamber cover 40 is provided in 40 d of top plates near the cylindrical part 40e.

In this embodiment, the rough grinding chamber cover 38 and the finish grinding chamber cover 40 are integrally formed. That is, the top plates 38d and 40d are connected near the boundary side wall 36a at the boundary between the rough grinding chamber cover 38 and the finish grinding chamber cover 40 .

The front side walls 38a and 40a are connected near the boundary side wall 36a, and similarly, the rear side walls 38b and 40b are connected near the boundary side wall 36a.

In addition, the gap between the front side walls 38a, 40a and the upper surface of the turntable 14 is fixed to the turntable 14 so that grinding chips and the like do not scatter from the inside of the processing chamber cover 36 to the loading and unloading area A. A partition (not shown) on the upper surface is substantially closed.

In this embodiment, one vibration applying unit 42 is installed on the outer side of the outer side wall 40c. The vibration applying unit 42 includes a rectangular plate-shaped ultrasonic oscillator (oscillating element) 44 (see FIG. 3 ) made of piezoelectric ceramics such as lead zirconate titanate (PZT).

FIG. 3 is a partial sectional side view showing the interior of the processing chamber cover 36. As shown in FIG. As shown in FIG. 3 , an AC voltage of a predetermined frequency at which the ultrasonic oscillator 44 resonates is applied to the ultrasonic oscillator 44 from a high-frequency power generator 46 such as an oscillator.

The ultrasonic oscillator 44 is arranged such that its polarization direction is substantially perpendicular to the outer side wall 40c. When the ultrasonic vibrator 44 oscillates at a predetermined frequency of ultrasonic vibration of about 100 kHz to 1 MHz (see the double arrow in FIG. 3 ), the vibration of the outer side wall 40 c is transmitted to the entire processing chamber cover 36 .

In this way, ultrasonic vibration is applied to the front side wall 38a, the rear side wall 38b, the outer side wall 38c, the top plate 38d, the front side wall 40a, the rear side wall 40b, the outer side wall 40c, the top plate 40d and the boundary side wall 36a.

In this embodiment, the vibration applying unit 42 applies ultrasonic frequency vibrations to the side wall and the top plate constituting the processing chamber cover 36, so that the grinding chips adhering to the processing chamber cover 36 fall down, and the grinding chips are removed from the processing chamber cover 36. .

On the other hand, when the inside of the processing chamber cover 36 is cleaned by spraying the fluid from the nozzle, a dead space where the fluid cannot reach is formed. However, by oscillating the process chamber cover 36 directly, a wider area of the process chamber cover 36 can be cleaned than by a fluid jet from a nozzle.

In addition, since the vibration of the ultrasonic frequency is transmitted to the entire processing chamber cover 36, when the grinding water adheres to the processing chamber cover 36, not only the grinding chips but also the grinding water can be dropped and removed.

Next, a method of using the grinding device 2 will be described. First, a predetermined number of wafers 11 accommodated in the cassette 8a are sequentially loaded into the chuck table 16 located in the loading/unloading area A.

Although the first wafer 11 is roughly ground in the rough grinding region B, it is finely ground in the fine grinding region C, but during this fine grinding, the second wafer 11 will be roughly ground, and the third wafer 11 will be roughly ground. The wafer 11 is loaded into the chuck table 16 in the loading/unloading area A. As shown in FIG.

When the first wafer 11 returns to the loading/unloading area A, the second wafer 11 is finish ground in the finish grinding area C, and the third wafer 11 is rough ground in the rough grinding area B. Between the finish grinding of the second wafer 11 and the rough grinding of the third wafer 11 , the first wafer 11 is carried out from the loading and unloading area A, and the fourth wafer 11 is loaded in instead.

The wafer 11 after finish grinding is carried out from the loading/unloading area A to the spin cleaning device 48 , and after the surface to be ground (that is, the back surface) is mainly cleaned by the spinning cleaning device 48 , the wafer 11 is dried (processing step).

The dried wafer 11 is transferred to the cassette 8 b by the wafer transfer robot 10 . In this way, all the wafers 11 in the cassette 8a are sequentially ground and cleaned, and then transferred to the cassette 8b.

After the processing step, the vibration applying unit 42 is operated to apply vibration of ultrasonic frequency to the processing chamber cover 36 . Thereby, the grinding chips and grinding water adhering to the processing chamber cover 36 are dropped and removed from the processing chamber cover 36 (cleaning step). In addition, at this time, the wafer 11 shown by the dotted line in FIG. 3 is not on the holding surface 16a.

Grinding chips may also fall down to the holding surface 16a. However, the grinding chips falling on the holding surface 16a are cleaned and removed by a cleaning unit (not shown) installed near the loading and unloading area A. As shown in FIG. The cleaning unit includes, for example, a nozzle that sprays cleaning water such as pure water, and a leveling stone that is formed of alumina or the like and has a predetermined hardness.

In this embodiment, vibration is applied to the processing chamber cover 36 by means of the vibration applying unit 42 having the ultrasonic oscillator 44, thereby removing the grinding chips adhering to the processing chamber cover 36. Therefore, compared with using fluid from the nozzle In the case of cleaning the processing chamber cover 36 by spraying, a wider range of the processing chamber cover 36 can be cleaned.

In addition, during the processing step, the processing chamber cover 36 can also be vibrated at an ultrasonic frequency. Thereby, grinding chips and grinding water become less likely to adhere to the machining chamber cover 36 . Therefore, in the cleaning step after the grinding step, grinding chips and the like can be more reliably removed from the processing chamber cover 36 .

Next, a second embodiment will be described. FIG. 4 is a partial sectional side view showing the inside of the processing chamber cover 36 in the second embodiment. In the second embodiment, the processing chamber cover 36 is supported on the upper surface of the base 4 through the buffer material 50 .

The cushioning material 50 is, for example, general anti-vibration rubber or anti-vibration rubber used in machine tools, but it may also be made of elastic members such as rubber and resin. By providing the buffer material 50, the transmission of the vibration of the ultrasonic frequency to the base 4 can be reduced.

Therefore, even if the vibration applying unit 42 is operated in the middle of the processing step of the wafer 11, the vibration of the ultrasonic frequency becomes difficult to be transmitted to the rough grinding unit 24a, the fine grinding unit 24b, and the chuck table 16, so it can be reduced by The impact of the vibration of the vibration applying unit 42 on the machining accuracy.

In addition, the structure, method, etc. of the above-mentioned embodiment can be changed suitably and implemented as long as it does not deviate from the scope of the object of this invention. In the above-mentioned embodiment, the example in which the vibration applying means 42 is provided outside the outer side wall 40c is demonstrated.

However, the vibration applying unit 42 can also be disposed on other side walls and top plates. In addition, the vibration applying unit 42 may be provided not outside the processing chamber cover 36 but inside.

In addition, in the above-mentioned example in which the rough grinding chamber cover 38 and the finish grinding chamber cover 40 are integrally formed, only one vibration applying unit 42 is required to be attached to the processing chamber cover 36, but a plurality of vibration applying units 42 may also be provided. Attached to the processing chamber cover 36 .

However, when a plurality of oscillation applying units 42 are attached to the processing chamber cover 36, the arrangement, oscillation frequency, and amplitude of each oscillation applying unit 42 are appropriately adjusted so that the oscillations do not interfere with each other and cancel each other out.

However, in the case where the rough grinding chamber cover 38 and the finish grinding chamber cover 40 are not connected to each other but are separated, one or more vibration applying units 42 are respectively provided in the rough grinding chamber cover 38 and the finish grinding chamber cover 40 .

2: Grinding device (processing device) 4: Abutment 4a: Wall 6a, 6b: Cassette loading table 8a, 8b: Cassette 10: Wafer transfer robot 11: Wafer (processed object) 12: Positioning platform 14:Rotary table 16: Chuck table 16a: Keeping surface 18: Loading arm 20: Unloading arm 22a, 22b: Grinding feed mechanism 24a: Rough grinding unit (machining unit) 24b: Finishing grinding unit (processing unit) 26: Spindle housing 28: Spindle 30: Rotary drive source 32: Mounting parts 34a: Rough grinding wheel (processing tool) 34b: Finishing grinding wheel (processing tool) 36: Processing chamber cover 36a: Junction side wall 38: Rough grinding chamber cover 40: Fine grinding chamber cover 38a, 40a: front side wall 38b, 40b: rear side wall 38c, 40c: Outer side wall 38d, 40d: top plate 38e, 40e: Cylindrical part 38f, 40f: doors 42: Shock applying unit 44: Ultrasonic oscillator (oscillating element) 46: High-frequency power generation device 48:Rotary cleaning device 50: buffer material A: Moving in and out area B: Rough grinding area C: Fine grinding area

Fig. 1 is a perspective view of a grinding device in a state where a processing chamber cover has been removed. Fig. 2 is a perspective view of the grinding device with the processing chamber cover installed. Fig. 3 is a partial sectional side view showing the interior of the processing chamber cover. Fig. 4 is a partial sectional side view showing the inside of a processing chamber cover in a second embodiment.

2: Grinding device (processing device)

4: Abutment

4a: Wall

6a, 6b: Cassette loading table

8a, 8b: Cassette

10: Wafer transfer robot

11: Wafer (processed object)

12: Positioning platform

14:Rotary table

16: Chuck table

16a: Keeping surface

18: Loading arm

20: Unloading arm

22a, 22b: Grinding feed mechanism

24a: Rough grinding unit (machining unit)

24b: Fine grinding unit (processing unit)

26: Spindle housing

28: Spindle

30: Rotary drive source

32: Mounting parts

34a: Rough grinding wheel (processing tool)

34b: Fine grinding wheel (processing tool)

36: Processing chamber cover

36a: Junction side wall

38: Rough grinding chamber cover

40: Fine grinding chamber cover

38a, 40a: front side wall

38b, 40b: rear side wall

38c, 40c: Outer side wall

38d, 40d: top plate

38e, 40e: Cylindrical part

38f, 40f: doors

42: Shock applying unit

48:Rotary cleaning device

A: Moving in and out area

B: Rough grinding area

C: Fine grinding area

Claims (3)

A processing device, characterized in that it has: chuck table, which holds the workpiece; a processing unit, which has a main shaft, and processes the workpiece attracted and held by the chuck table with a processing tool installed at the lower end of the main shaft; a processing chamber cover, which has a top plate and a side wall, and covers the sides and the top of the chuck table and the processing tool; and The vibration applying unit has a vibration element and applies vibration to the side wall and the top plate of the processing chamber cover. The processing device according to claim 1, wherein the oscillator has an ultrasonic oscillator. The processing device according to claim 1 or 2, wherein the processing chamber cover is supported on the base supporting the processing unit through a buffer material.

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