JPH06169013A - Dicing device and cutting control method in the dicing device - Google Patents

Abstract

PURPOSE:To cover a dicing device which is definitely excellent in terms of grooving work, and what is more, to embody a dicing device which has upgraded cutting speed and a cutting control method in the dicing device. CONSTITUTION:In terms of a dicing device which provides a spindle motor 2 which rotates a wheel blade 1 at a high speed, a mobile mechanism 3 which moves a work piece to the wheel blade 1 and a control section 6 which controls the rotation of the spindle motor 2 and the feed of the mobile mechanism 3, a load detection means 5 is installed to detect an electric power value of the spindle motor 2. The control section 6 forces at least one of the feed speed of the mobile mechanism 3 and the rotary speed of the spindle motor 2 to be changed based on the electric power value thus detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing machine and a cutting control method for improving machining efficiency while performing good machining in a dicing machine.

[0002]

2. Description of the Related Art A dicing apparatus for rotating a grindstone blade, which is formed by binding diamond or the like with a metal such as nickel, at high speed to perform groove processing is used for separating each chip from a semiconductor wafer. FIG. 3 is a perspective view showing the basic configuration of the dicing device. In FIG. 3, 31 is a grindstone blade, and 300 is a semiconductor wafer to be processed.
321 is a spindle motor that rotates the blade 31 at high speed, and 322 and 323 are support members for the spindle motor. 331 is a stage on which the wafer 300 is placed and fixed by vacuum suction. The stage 331 needs to be movable in three axis directions, and is provided in the XYZ moving mechanism. Reference numerals 332 and 333 denote moving bases in the X and Y directions.

The blade is formed by binding abrasive grains such as diamond with a metal such as nickel, and is gradually worn away during processing. In the case of processing a semiconductor wafer, pure water is supplied during the processing. A blade with a predetermined thickness is selected according to the shape of the groove to be processed, and the depth of cut is determined.However, in order to perform good processing, the blade rotation speed, feed speed during processing, and cutting water supply It is necessary to set various cutting conditions such as quantity to appropriate values. Therefore, for the material of the workpiece and the shape of the groove to be machined, the above cutting conditions are actually changed to various conditions for cutting, the condition of the processed groove is inspected, and the cutting conditions are set. Had decided. At this time,
The conditions are determined so as to obtain a cutting speed as high as possible within a range in which a groove with sufficient accuracy can be processed.

[0004]

However, in reality, the cutting conditions are affected by factors such as variations in blade manufacturing and pH concentration of cutting water, but it is difficult to manage these factors sufficiently. Is the current situation. The blade itself also changes according to the processing. Therefore, there is a problem in that sufficient groove processing cannot be sufficiently stably performed only with the cutting conditions determined as described above.

Therefore, in general, it is easy to perform good groove processing by decreasing the feed rate, and therefore, it is possible to always perform good groove processing by decreasing the feed rate. However, this causes a problem that the processing speed (throughput) is reduced. Further, when the conditions largely change, the problem that the processing failure is likely to occur beyond the set allowable range remains as it is.

The present invention has been made in view of the above problems, and it is an object of the present invention to improve the processing speed as much as possible without reducing the processing condition in a dicing device.

[0007]

A dicing apparatus of the present invention has a spindle motor for rotating an attached grindstone blade at a high speed and a stage for mounting the workpiece, and moves the workpiece with respect to the grindstone blade. In order to achieve the above-mentioned object, a load detecting means for detecting the power value of the spindle motor is provided, and the control section detects the moving mechanism and the control section for controlling the rotation of the spindle motor and the feeding of the moving mechanism. At least one of the feed speed of the moving mechanism and the rotation speed of the spindle motor is controlled based on the electric power value.

[0008]

As described above, until now, the feed speed of the work piece and the rotation speed of the spindle motor have been kept constant, and the feed speed has been set to a slow speed with a certain amount of allowance so that good machining can be performed. It was The cutting conditions fluctuate due to factors such as variations in blade manufacturing and the pH value of the cutting water. However, when the feed speed of the work piece and the spindle motor rotation speed are constant as described above, there are almost no fluctuations in the cutting conditions. Correspondingly, it was found that the load of the spindle motor, that is, the electric power value of the spindle motor fluctuates. Therefore, it can be said that if the electric power value of the spindle motor is detected, the variation of the cutting condition can be known, and conversely, if the electric power value is within a predetermined range, good machining can be performed.

Therefore, if the electric power value of the spindle motor is detected and the feed speed of the work piece and the rotation speed of the spindle motor are controlled so that the electric power value is close to the upper limit value within a predetermined range, good machining can be achieved. It can be said that machining can be performed most efficiently within the range that can be performed. Of course, there is a predetermined permissible range for the feed speed of the work piece and the rotation speed of the spindle motor, and these must be within the permissible range.

[0010]

1 is a diagram showing the configuration of an embodiment in which the present invention is applied to a semiconductor wafer dicing apparatus. In FIG. 1, 1 is a thin grindstone blade (blade), and 2 is a spindle motor for rotating the blade 1 at high speed. Reference numeral 3 denotes a moving mechanism including a stage for mounting and moving the semiconductor wafer 100. A high frequency motor driver 4 generates a drive signal for the spindle motor 2 in accordance with a control signal. A control unit 6 sends a signal for controlling the rotation speed of the spindle motor 2 to the high frequency motor driver 4 and also controls the feed speed of the stage. A power meter 5 detects the power value of the high frequency motor driver 4.

In the dicing device, the blade thickness of the blade 1 is automatically determined according to the shape of the groove to be machined.
The factors that can be controlled are the feed speed of the stage and the rotation speed of the spindle motor 2. The cutting water supply rate is also constant. Therefore, the feed speed and the rotation speed are combined to perform control so that optimum machining can be performed, but here, in order to simplify the description, a case where only the feed speed is controlled will be described first.

The higher the stage feed rate, the more the amount of machining per unit time increases, so the load on the spindle motor increases and the machining condition decreases. FIG. 2 is a diagram schematically showing the machining position in relation to the electric power value and feed rate of the spindle motor 2 in the embodiment, and the example of the conventional example is shown by a broken line. As shown in FIG. 2 (c), in the conventional dicing apparatus, the stage feed speed is constant, and the power value of the spindle motor 2 is shown in FIG. 2 (b).
Fluctuates like. At this time, if the electric power value exceeds the upper limit of the allowable range, the processing condition becomes insufficient, so the stage feed speed was set so as not to exceed the upper limit of the allowable range at the maximum electric power value. . Further, when the conditions largely fluctuate, the upper limit is exceeded, and processing defects are likely to occur.

On the other hand, in the dicing apparatus of the present invention, the power value of the spindle motor 2 is constantly detected by the power meter 5. The control unit 6 reads the electric power value and feedback-controls the stage feed speed so that the electric power value becomes a constant value close to the upper limit of the allowable range. Therefore, as shown in (b) of FIG. 2, the electric power value of the spindle motor 2 is constant at a high value within the allowable range, and the feed rate is as shown in FIG.
It changes like (c). As is clear from the figure, the feed rate is always higher than that in the conventional dicing apparatus, and therefore the time required to process one groove is shortened.
Moreover, since the power value is within the allowable range, good processing can be performed.

The case where the stage feed speed is controlled according to the electric power value of the spindle motor 2 has been described above. Next, the case where the rotation speed of the spindle motor 2 is controlled will be described. Although the machining speed does not change even if the rotation speed of the spindle motor 2 is changed, good machining can be generally performed by increasing the rotation speed. When the rotation speed is increased, the electric power value of the spindle motor 2 is increased accordingly. Therefore, in the actual machining, the rotation speed of the spindle motor is not set to the maximum value, but is set to an appropriate low rotation speed in consideration of the load actually applied.

Therefore, in the second control mode of the present embodiment, the feed rate of the stage is kept constant and the rotation speed of the spindle motor 2 is controlled in accordance with the electric power value to improve the processing condition. That is, when the detected electric power value is within the allowable range in the state where the feeding speed is constant,
The rotation speed of the spindle motor 2 is increased within the allowable range. As a result, the processing condition is improved, and the frequency of occurrence of defects is correspondingly reduced.

Further, not only one of the stage feed speed and the rotation speed of the spindle motor 2 may be controlled, but both may be controlled. For example, when the rotation speed is below a predetermined value, the feed speed is fixed to a low value and controlled so that the rotation speed is as high as possible, and when the rotation speed reaches a predetermined value, the rotation speed is fixed to that value and the feed Control to increase the speed as much as possible.

Further, based on the result of actual machining, the optimum control relationship between the electric power value of the spindle motor and the rotation speed and the feed speed of the stage is determined in advance, and this relationship is stored in the control unit. Alternatively, each parameter may be controlled according to the read power value.

[0018]

As described above, according to the present invention, it is possible to realize a dicing apparatus which can surely perform good processing and which has an improved processing speed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram schematically showing changes in electric power value and feed rate of a spindle motor according to the present invention.

FIG. 3 is a diagram showing a configuration of a dicing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Grinding stone blade (blade) 2 ... Spindle motor 3 ... Moving mechanism 4 ... High frequency motor driver 5 ... Load detection means 6 ... Control unit

Claims (2)

[Claims] 1. A spindle motor (2) for rotating an attached grindstone blade (1) at a high speed, and a stage for mounting a workpiece (100). The workpiece (100) includes a moving mechanism (3) for moving the workpiece (100) and a control unit (6) for controlling the rotation of the spindle motor (2) and the feeding of the moving mechanism (3). ) In the dicing device for performing thin groove processing, load control means (5) for detecting the electric power value of the spindle motor (2) is provided, and the control section (6) is based on the detected electric power value. At least one of the feed speed of 3) and the rotation speed of the spindle motor (2) is changed. 2. A cutting control method for a dicing device, comprising a spindle motor (2) for rotating a grindstone blade (1) at a high speed.
Is detected, and at least one of the feed rate of the workpiece (100) and the rotation speed of the spindle motor is changed based on the detected power value.