JPH1015790A - Working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent adhesion of a working tool due to static electricity by executing working while static elimination is performed for the atmosphere of the periphery including a working area by a static electricity eliminating means to prevent adhesion of contamination caused by working chips. SOLUTION: A working area is a part which is under a drum part 17 and includes a chuck table 12, and in which a spindle 19 projected from the drum part 17, a wheel 20 and a grinding wheel 21 are positioned. Air ionized by a static eliminator 36 is supplied to the working area through a hose 35 to overall eliminate the static electricity of the atmosphere of the working area. In the actual grinding process, static electricity produced by friton of a dynamic part such as a spindle 19 or the like is removed positively and let flow away without adhesion to be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a grinder apparatus for grinding a material such as a semiconductor wafer using a grinding wheel, or a dicing apparatus for cutting a plurality of dies using a diamond blade. The processing method to be performed.

[0002]

2. Description of the Related Art A grinder or dicing apparatus of this type is well known. For example, a dicing apparatus has a configuration as shown in FIG.

In this conventional apparatus, at least the apparatus main body 1 is provided with a chuck table 3 for dicing a semiconductor wafer 2 and a spindle shaft 5 equipped with a diamond blade 4. The chuck table 3 is configured to be horizontally movable in a direction perpendicular to the blade 4 via a predetermined moving mechanism. Further, the semiconductor wafer 2 is supplied in a state of being stuck and placed on a predetermined frame 7 through an sticking tape 6. And
A processing area where the chuck table 3 and the diamond blade 4 are located, and a periphery including the processing area are covered with a cover 8 formed of a so-called acrylic plate made of, for example, a transparent acrylic resin.

A semiconductor wafer 2 mounted on a chuck table 3 is cut into a chip size by a blade 4 while supplying a processing liquid such as cutting water. Is generated, and the cutting powder adheres to the wafer surface as an impurity. The reason for this is that the supply of cutting water is not sufficient, or even if the supply of cutting water is sufficient, pure water with a high specific resistance is used to prevent contamination of the wafer by impurities. There is a problem that the cutting powder is electrostatically attached to the wafer surface due to the generation of the particles.

In order to solve these problems, various kinds of cutting water supply nozzles have been proposed, and carbon dioxide has been added to pure water in order to lower the pure specific resistance and prevent the electrostatic adhesion of chips. It is common practice to lower the specific resistance by mixing.

[0006]

However, when a wafer is cut into small chips, a machining fluid is supplied to the cut portion and its vicinity.
In addition, since the processing time is long, the possibility of contamination of the processed portion and the unprocessed portion is increased, and it is difficult to substantially cope with the contamination only by modifying the supply nozzle of the grinding water. Also, if the amount of carbon dioxide (carbon dioxide) is increased, the effect of preventing electrostatic adhesion is increased.
The mixing of carbon dioxide turns pure water into carbonated water, which lowers the pH and corrodes the patterns formed on the wafer and corrodes the blades, causing serious problems in processing results. Will be.

Further, in a grinder apparatus as a conventional example, ultrapure water is used as a processing liquid for grinding a wafer. Since this ultrapure water is an insulator,
High-speed rotation of the wheel during grinding generates static electricity.
Due to the action of the static electricity, the grinding powder, which is the processing dust of the wafer, adheres to the grinding portion and the peripheral device side, and the grinding powder adhered to the cement portion by the operation of the device for a long time becomes a state of cement. .

[0008] When the grinding powder is fixed as described above, not only does it hinder the replacement of the wheel, but when the fixed cutting powder grows to a certain size, it drops into the apparatus and causes the chuck table to fall. It may contaminate or fall on the wafer being ground, adversely affecting the grinding.
Therefore, in general, there has been no countermeasure for preventing contamination except for periodic cleaning and inspection.

Therefore, the prior art has a problem to be solved in the prevention of the attachment of cutting chips or cutting chips made of cutting powder due to static electricity in wafer cutting or grinding.

[0010]

As a specific means for solving the problems of the conventional example, the present invention relates to a processing method for performing processing with a grindstone while supplying a processing liquid to a workpiece such as a semiconductor wafer. And a processing method for performing processing while removing static electricity by a static electricity removing means in a surrounding atmosphere including a processing area in order to prevent adhesion of contamination due to processing waste. Is grinding, the grindstone used is a grinding wheel, and the processing of the workpiece is dicing,
This includes that the grindstone used is a diamond blade, and that the means for removing static electricity is ionized air supplied through an ion generator.

In the processing method of the present invention, since the processing is performed while removing the static electricity generated in the processing area, the processing waste does not adhere to the workpiece or the periphery of the processing portion due to the static electricity. Contamination is avoided and cleaning and inspection are significantly easier.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the illustrated embodiments. First, a first embodiment shown in FIGS. 1 and 2 shows a semiconductor wafer grinder apparatus, in which a chuck table 12 is provided at a predetermined position of a machine body of an apparatus body 10, that is, a table 11, and the chuck table 12 is provided. The table 12 is supported by a support member 13 and is rotatably provided by a servomotor 14. The rotational drive of the servo motor 14 is controlled by an encoder 15, and the encoder 15 is controlled by a computer described later.

The semiconductor wafer 2 to be subjected to grinding is mounted on the chuck table 12 as it is, and is suction-fixed by an appropriate suction means or the like.

Above the chuck table 12, a polishing means 16 is provided. The polishing means 16 comprises a cylindrical body 17 and a motor 18 mounted on the upper part of the body.
A spindle 19 driven by the motor and projecting downward from the body, a wheel 20 attached to the spindle, and a grindstone 21 detachably attached to the wheel.

The body 17 is vertically movably attached to a wall 22 provided upright from the table 11. That is, the pair of rails 2
3 is provided, and a slide plate 24 that moves up and down along the rail is provided. A support plate 25 attached to the body 17 is fixed to the slide plate 24 by appropriate fixing means such as bolts, and the polishing means 16 is vertically moved by the vertical movement of the slide plate 24. .

The vertical movement of the slide plate 24 is performed by a drive unit provided on the back side of the wall 22. That is, the shaft portion 27 is integrally attached to the rear surface side of the slide plate 24, and the shaft portion penetrates the groove-shaped through hole 26 provided in the wall body 22 and projects to the rear surface side of the wall body 22. It is attached by being engaged with a screw rod 28 arranged in a direction perpendicular to the protruding shaft portion, that is, in a vertical direction.

The upper and lower ends of the screw rod 28 are supported, and a driving section 29 such as a pulse motor is connected to the upper end side. The driving of the driving section 29 causes the screw rod 28 to rotate. Is moved up and down, so that the slide plate 24 and the polishing means 16 move up and down.

The slide plate 24 and the polishing means 16
The degree of vertical movement is finely adjusted according to the scale of the linear scale 30 provided on the back side of the wall 22. That is, the sensor 2 is made to protrude from the shaft portion 27 and
7a is provided, and the linear scale 3 is
The scale of 0 is read, and the vertical movement is adjusted based on the read scale information.

The grinder apparatus 10 is controlled by a so-called computer 31. The servo motor 14 for driving the chuck table 12 is driven by a servo driver 32. The driving state is taken out as information by an encoder 15, and The computer 31 drives the servo driver 32 based on the information. Accordingly, the chuck table 12 is substantially controlled by the computer 31.

The driving of the driving unit 29 for moving the grinding means 16 up and down is controlled by a pulse motor driver 33, which is controlled by a computer 31. Therefore, the cutting means 16
Is substantially controlled by the computer 31.

In the grinder apparatus 10 having such a structure, a wheel cover 34 is attached to a lower portion of the body 17 so as to surround a processing area of the grinding means 16, and one end of an air supply hose 35 is attached to the wheel cover. The other end of the hose is connected to a static eliminator (ionizer) 36.

The processing region in this case is a portion below the body 17, including the chuck table 12, where the spindle 19, the wheel 20, and the grindstone 21 projecting from the body 17 are located. Then, the air ionized by the static eliminator 36 is supplied to the processing area via the hose 35, and the atmosphere in the processing area is completely discharged.

In the actual grinding process, the spindle 1
Static electricity generated by friction of dynamic parts such as 9 is positively removed, and when a semiconductor wafer or the like set on the chuck table 12 is ground by the grindstone 21, most of the processing waste is cut. Processing chips that are removed by flowing on the table 11 together with the liquid are scattered or floated around, are received by the wheel cover 34, and are also disposed on the lower surface of the body 17 in the processing area, the peripheral surface of the spindle 19, and the wheel. 20 will come into contact with the outer peripheral surface,
Since the static electricity has been removed, almost all of them are removed by flowing down without adhering.

In the above-described embodiment, the description has been given of the case where the surrounding atmosphere is eliminated in the processing area. However, in the grinder device, for example, the processing area and its periphery are formed of a transparent acrylic plate made of acrylic resin or the like. 37, and its cover 3
It suffices if the atmosphere in 7 is completely discharged. Therefore, the air supply hose 35 may be connected to an appropriate position on the cover 37 to supply ionized air into the cover. Incidentally, a plurality of hoses 35 may be connected from different directions.

In any case, it is important that the atmosphere in the processing area is neutralized, and when the processing area is surrounded by a predetermined enclosure, the surrounding atmosphere including the inside of the enclosure is removed. Can be called.

Therefore, in the processing area, since the static electricity in the surrounding atmosphere including the processing area is continuously removed during the grinding operation, the processing waste does not adhere to the peripheral portion. It is.

The second embodiment shown in FIGS. 3 and 4 shows a cut portion of a main part in a dicing apparatus similar to the conventional example. Also in this dicing device,
A workpiece such as a semiconductor wafer is cut by a blade 38, which is attached to a spindle 39, which is rotatably supported by a bearing 40.

The portion where the blade 38 is located is referred to as a so-called head portion 41 and is referred to as a blade monitoring means 4.
2. A lid 44 and the like provided with a processing liquid supply means 43 are attached, and the whole is in an enclosed state. Therefore, in the dicing apparatus having the blade 38,
The portion where the head section 41 including the chuck table (not shown) is located corresponds to a so-called processing area.

In this dicing apparatus, one end of a hose 35 for supplying air is connected to the head portion 41 which is a processing region at at least one position, as in the first embodiment. The unit is connected to a static eliminator (not shown) similar to the above. In this case,
A communication hole 45 that communicates to the inside of the member constituting the head portion 41 and the lid 44 is formed in advance.
If the distal end of the hose 35 is inserted through 5, the connection can be made easily. In this case, the hose 35 is connected to the processing area at two locations.

In actual use, the blade 38 is rotated at a high speed (for example, 30,
00 RPM), and the cuttings generated by the cutting operation flow down together with the cutting fluid and are removed. However, the rotation of the blade 38 and the member supporting the blades still removes the cutting fluid and the cutting debris. The part scatters in the internal space of the head part 41 and tries to adhere to the wall surface of the internal space.

However, since the ionized air is continuously supplied to the processing area including the internal space of the head portion 41, static electricity generated by a dynamic portion in the processing area is positively removed. As a result, the processing fluid and the processing chips scattered inside are hardly charged, so that they flow down without being attached to the inner wall surface, and are removed, thereby substantially eliminating the adhesion due to static electricity.

Also in this dicing apparatus, the periphery including the processing area may be covered with a cover 8 (see FIG. 5) formed of a transparent acrylic plate, similarly to the above-mentioned conventional example. It is in the state that was done.
The inside of the partitioned area can be regarded as the surrounding atmosphere including the processing area, and the ionized air may be supplied to the partitioned area to remove the electricity. For this purpose, a hose 35 for supplying air may be connected to the cover or an appropriate portion.

Therefore, since the surrounding atmosphere including the processing area is neutralized, the cutting chips due to the static electricity are prevented from adhering and depositing on the wall surfaces of the members constituting the processing area and on the peripheral devices and members. Even if the processing operation is performed continuously, substantial contamination, that is, contamination, in the processing area and its surroundings is eliminated.

[0034]

As described above, the processing method according to the present invention is a processing method for performing processing with a grindstone while supplying a processing liquid to a workpiece such as a semiconductor wafer. In order to prevent the adhesion, the surrounding atmosphere including the processing area is processed while removing the static electricity by means of static electricity removing means, thereby eliminating the charging phenomenon due to the static electricity of the processing chips scattered in the processing area and thereby processing. Processing dust due to static electricity will not adhere to the surrounding members that make up the area and the walls of the device,
Even if the machining operation is continued for a long time, there is an excellent effect that the contamination of the workpiece due to the dropping of the processing waste, which has conventionally occurred, can be largely eliminated.

Further, since the static electricity removing means is ionized air supplied through an ion generator, it can be easily added to a conventional processing apparatus, and furthermore, it can be used in a surrounding atmosphere including a processing area. The positive effect of static elimination is not only able to completely eliminate the adverse effects of static electricity on the workpiece, but also has an excellent effect of eliminating the need to mix carbon dioxide.

Further, since the adhesion of the processing chips can be eliminated in the processing area, the solidification phenomenon of the processing chips is eliminated,
Not only does not cause any trouble when replacing the processing jig, etc., but also the solidified cutting powder falls into the equipment and contaminates the chuck table, or drops on the wafer being ground and is used for grinding. It has an excellent effect that adverse effects can be eliminated.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a main part of a grinder mounting according to a first embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a main part of the embodiment.

FIG. 3 is a perspective view schematically showing only a main part of a dicing apparatus according to a second embodiment of the present invention and partially exploded.

FIG. 4 is a perspective view schematically showing only a main part of the embodiment.

FIG. 5 is a perspective view showing a conventional dicing apparatus.

[Explanation of symbols]

Reference numeral 10: Device body, 11: Table, 12: Chuck table, 13: Support member, 14: Servo motor, 15: Encoder, 16: Polishing means,
17 ... body, 18 ... motor, 19 ... spindle, 20 ... wheel, 21 ... whetstone, 22 ...
Wall, 23 ... rail, 24 ... slide plate, 25
...... Support plate, 26 ... Through-hole, 27 ... Shaft, 27
a sensor, 28 screw rod, 29 drive unit, 30 linear scale, 31 computer, 32 servo motor, 33 pulse motor driver, 34 wheel cover, 35 Hose, 36 …… Static electricity removal device, 37 …… Cover,
38 ... blade, 39 ... spindle, 40 ...
Bearing part 41 head part 42 blade monitoring means 43 working fluid supply means 44 lid body 45
…… Communication hole.

Claims (4)

[Claims] 1. A processing method for performing processing with a grindstone while supplying a processing liquid to a workpiece such as a semiconductor wafer, wherein a surrounding atmosphere including a processing region is formed in order to prevent contamination from being caused by processing chips. A processing method characterized in that processing is performed while removing static electricity by static electricity removing means. 2. The processing method according to claim 1, wherein the processing of the workpiece is grinding, and the grindstone used is a grindstone. 3. The processing method according to claim 1, wherein the processing of the workpiece is dicing, and the grindstone used is a diamond blade. 4. The processing method according to claim 1, wherein the static electricity removing means is ionized air supplied through an ion generator.