JPH08174416A - Fine cutting device - Google Patents

Abstract

PURPOSE: To provide the fine cutting device, which can accurately detect the quantity of abrasion of a blade even in the case where thermal distortion is generated in a cutting unit, in which a blade is installed. CONSTITUTION: This fine cutting device is provided with a chuck table for holding a material to be worked, a cutting unit 14 including a rotary blade 1, and a position detecting sensor 2 for detecting position of the rotary blade 1. In this fine cutting device, a piece 16 to be detected by the position detecting sensor 2 is arranged at the required position of the cutting unit 14. The piece 16 to be detected is arranged adjacent to the blade 1. Quantity of abrasion of the blade 1 is detected by detecting the piece 16 to be detected and the blade 1 with the position detecting sensor 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision cutting device for cutting a semiconductor wafer or the like.

[0002]

2. Description of the Related Art Generally, a wafer attached to a frame via a tape is divided into individual chips by a dicing device. Since this dividing step is performed by cutting only the wafer and not cutting the tape or by cutting the tape slightly, the cutting direction (Z-axis direction) of the blade must be controlled with high precision. For this Z-axis direction control, the dicing device is usually provided with a position detection sensor 2 for detecting the position of the outer peripheral end of the blade 1 as shown in FIG. As shown in FIG. 5, the position detection sensor 2 has a concave cross-section, and a light-emitting element 2a and a light-receiving element 2b are provided opposite to each other with a groove 2c interposed therebetween. It is inserted so that its position can be detected optically. When the position detecting sensor 2 detects the outer peripheral end of the blade 1, the position is detected as shown in FIG.
The position is confirmed by reading the linear scale 3 shown in FIG. 3, and the confirmed position serves as a reference position for controlling the blade 1 in the Z-axis direction, and the cutting depth is controlled. (Instead of the linear scale 3, the number of pulses of the pulse motor is counted and Z
In some cases, axial control is performed. ) The position detection of the outer peripheral end of the blade 1 is periodically performed because it changes over time due to wear, and the wear amount of the blade 1 can be detected by accumulating the change over time of the reference position of the blade 1. Also, it is possible to know when to replace the blade.

[0003]

However, the position of the Z axis of the blade 1 is controlled by the linear scale 3 or the like, but the thermal expansion of the cutting unit or the like equipped with the blade 1 causes the reading of the linear scale 3 and the actual blade. There may be an error with the position of. That is, the change of the position of the blade 1 with time does not only depend on the wear of the blade 1 but also the thermal strain of the cutting unit. Under such a situation, the position detection sensor 2 detects the position of the blade 1. Even if it is detected, it cannot be accurately grasped whether it is solely due to the wear of the blade 1 or is also affected by the thermal strain of the cutting unit. In other words, there is a problem that the wear amount of the blade cannot be accurately detected even if the reference position for controlling the blade 1 in the Z-axis direction can be detected. Therefore, an object of the present invention is to provide a precision cutting device capable of accurately detecting the wear amount of a blade even if it is affected by the thermal strain of the cutting unit.

[0004]

As a means for technically solving the above problems, the present invention provides a chuck table for holding a workpiece, a cutting unit including a rotary blade, and a position of the rotary blade. In the precision cutting device including at least the position detecting sensor, a precise cutting device is provided, in which a detected piece detected by the position detecting sensor is arranged at a required position of the cutting unit. Further, the gist is that the detected piece is disposed adjacent to the blade, and the wear amount of the blade is detected by the position detection sensor detecting the detected piece and the blade.

[0005]

[Operation] Since the detected piece does not contribute to cutting like a blade, it does not wear and the position of the lower end is always kept at a predetermined position. Therefore, the position of the detected piece is detected by the position detecting sensor, the outer peripheral end of the blade is detected by the position detecting sensor, and the amounts of wear of the blade can be accurately detected by comparing these. That is, even if thermal distortion occurs in the cutting unit, the effect is affected by the outer peripheral edge of the blade and the detected piece at the same level at the same time, so an accurate blade can be obtained by determining the difference between the detected values. It is possible to know the wear amount of. Further, the amount of thermal strain of the cutting unit can be known by detecting the detected piece.

[0006]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, reference numeral 4 is a precision cutting device (dicer), and a plurality of wafers W (attached to a frame F via an adhesive tape N), which are workpieces, are placed in a cassette mounting area 5 which moves up and down. The accommodated cassette 6 is placed, and the wafer W in the cassette 6 is unloaded to the standby area 8 by the loading / unloading means 7. The wafer W with the frame F carried out to the standby area 8 is carried onto the chuck table 10 by the carrying means 9 having a swing arm, sucked and held by the chuck table 10 and moved directly below the alignment means 11 to perform alignment. After that, it is diced by the cutting means 12 having the blade 1.

As shown in FIG. 2, the cutting means 12 has a spindle inside and a cutting unit 14 having a blade cover 13 attached to the tip thereof. The blade 1 is attached to the tip of the spindle. Nozzle tube 15 for supplying cutting fluid so as to sandwich the blade 1
Is disposed on the blade cover 13, and a plate-shaped detected piece 16 is fixed to a side portion of the blade cover 13.

The detected piece 16 is a blade cover 13
The chuck table so as to project downward from the lower end of the blade 1, preferably such that the lower end thereof is located above the lower end of the outer periphery of the blade 1 (a position where it does not come into contact with the workpiece during cutting). The position of the detection target piece 16 can be detected by the position detection sensor 2 attached to the corner of the support substrate 17 when the position 10 is moved.

The precision cutting device according to the present invention is constructed as described above, and in order to detect the wear amount of the blade 1, the position detecting sensor 2 first detects the lower end position of the piece 16 to be detected, and then the blade 1 By detecting the lower end position, the wear amount of the blade 1 can be accurately detected by the difference between the lower end position of the detected piece 16 and the lower end position of the blade 1.

This is because the detected piece 16 does not wear because it does not contribute to cutting, and its lower end position is always held at a predetermined position, which serves as a reference position for the amount of wear of the blade 1. Further, since the detected piece 16 is attached to the blade cover 13, even when thermal distortion occurs in the cutting unit 14, the influence of the thermal distortion on the outer peripheral end portion of the blade 1 and the detected piece 1 is affected.
6 receives the same level at the same time, and as described above, the difference between the lower end position detection values is obtained, so that the accurate wear amount of the blade 1 can be known. Further, the amount of thermal strain of the cutting unit 14 can be known by detecting the detected piece 16.

As a result, even if thermal distortion occurs in the cutting unit 14 due to heat during the cutting work, the wear amount of the blade 1 can always be accurately detected because the detected piece 16 is always at the reference position. Therefore, the control of the blade 1 in the Z-axis direction is perfect, the cutting process of the workpiece such as the wafer is precisely performed, and the blade 1 is properly replaced.

[0012]

As described above, according to the present invention,
The wear amount of the blade can always be detected accurately with the detected piece as the reference position, and the cutting direction (Z-axis direction) of the blade can be controlled with high accuracy, which guarantees precise cutting of the workpiece such as a wafer. It is possible to obtain an excellent effect that the blade replacement time can be properly recognized.

[Brief description of drawings]

FIG. 1 is an external view of a precision cutting device showing an embodiment of the present invention.

FIG. 2 is a schematic perspective view of the same part.

FIG. 3 is an explanatory diagram showing a Z-axis control mechanism of a blade.

FIG. 4 is a perspective view showing a conventional blade wear amount detecting means.

FIG. 5 is an explanatory diagram of a main part of the same.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Blade 2 ... Position detection sensor 3 ... Linear scale 4 ... Precision cutting device 5 ... Cassette mounting area 6 ... Cassette 7 ... Carrying-in / out means 8 ... Standby area 9 ... Conveying means 10 ... Chuck table 11
Alignment means 12 ... Cutting means 13 ... Blade cover 14 ... Cutting unit 15 ... Cutting fluid supply nozzle tube 16 ... Detected piece 1
7 ... Support substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/301

Claims (3)

[Claims] 1. A precision cutting device including at least a chuck table for holding a workpiece, a cutting unit including a rotary blade, and a position detection sensor for detecting a position of the rotary blade, wherein the cutting unit is provided at a required position. A precision cutting device having a piece to be detected detected by a position detection sensor. 2. The precision cutting device according to claim 1, wherein the detected piece is disposed adjacent to the blade. 3. The precision cutting device according to claim 1, wherein a wear amount of the blade is detected by a position detection sensor detecting the piece to be detected and the blade.