JP2002336775A - Ultrasonic torsional vibration type blade drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic torsional vibration type blade drive unit, the vibration body of which has high rigidity and which can process hard brittle material with high accuracy. SOLUTION: This ultrasonic torsional vibration type blade drive unit has a structure wherein a blade and a torsional vibration horn are fastened to each other through a washer with a torsional resonance frequency detuned from a deflective resonance frequency, and the diameter of the washer is made equal to or smaller than the difference between the diameter of the blade and the value 20 times the thickness of the blade.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing blade used for processing hard and brittle materials such as ceramics, sapphire and semiconductor wafers.
The present invention relates to an ultrasonic torsional vibration type blade drive device.

[0002]

2. Description of the Related Art Heretofore, as an ultrasonic driving device for a disk-shaped blade, a device utilizing bending vibration of the blade is known.

[0003] In the prior art, a longitudinal vibration ultrasonic horn and a blade are connected so that their combined body forms an axisymmetric shape, and the blade is driven at its bending resonance frequency to perform ultrasonic processing.

A conventional ultrasonic bending vibration type blade driving device will be described with reference to the drawings.

FIG. 2 is a sectional view showing an example of the prior art, in which a longitudinal vibration horn 1 and a blade 2 are fastened by bolts 3. When the longitudinal vibration horn 1 is fastened to the longitudinal vibration ultrasonic vibrator (not shown) by the connection screw 4 and excited, the longitudinal vibration mode of the horn 1 becomes 5 and the blade 2 becomes the bending vibration mode 6.

The bending vibration 6 generates concentric repetitive stresses at nodes (indicated by arrows) of the vibration of the disk blade 2,
This causes damage such as fatigue fracture and chipping of the blade 2.

Bolt 3 and longitudinal vibration horn 1 and blade 2
The contact surface diameter Dl must be set to a smaller diameter (DlＤλb / 2) than the half wavelength (λb / 2) of the bending vibration so as not to suppress the bending vibration of the blade 2. For this reason, the blade 2 is set to lack rigidity.

[0008]

In the prior art, the blade is damaged due to the use of the bending vibration of the blade. In addition, in order to realize highly efficient bending vibration of the blade, the diameter of the contact surface between the blade and the longitudinal vibration horn is small, and there is a disadvantage that the blade lacks rigidity. For this reason, there has been a long-felt need for a blade ultrasonic drive device that does not rely on flexural vibration means.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultrasonic drive device for a blade for processing a hard and brittle material, which has high rigidity and can prevent damage.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made by finding that a disk-shaped blade can be connected to an ultrasonic torsional vibration horn so as to be axially symmetrical, and a bending vibration mode of the blade can be suppressed. .

According to a first aspect of the present invention, an ultrasonic torsional vibration horn and a blade are coupled so that their combined body forms an axisymmetric shape, and the torsional vibration resonance frequency of the horn is detuned with the flexural vibration resonance frequency of the blade. This is an ultrasonic torsional vibration type blade driving device having a structure having a frequency adjusted as described above.

According to a second aspect of the present invention, in the first aspect of the present invention, the ultrasonic torsional vibration horn and the blade are further bolted via a washer having a diameter equal to the tip diameter of the horn. The diameter of the washer is equal to or smaller than a value obtained by subtracting a value of 20 times the thickness of the blade from the diameter of the blade.

[0013]

By setting the torsional vibration resonance frequency of the ultrasonic torsional vibration horn for driving the blade to a frequency detuned from the bending vibration resonance frequency of the blade, the bending vibration of the blade can be suppressed.

By connecting the blade and the ultrasonic torsional vibration horn via a washer having a constant diameter condition, an ultrasonic dicing process can be realized in which the blade is rich in rigidity and the bending vibration of the blade is suppressed.

[0015]

FIG. 1 is a schematic diagram showing an ultrasonic torsional vibration type blade driving device and a vibration mode according to the present invention.

As shown in the sectional view of FIG. 1, the ultrasonic torsional vibration type blade driving device 10 of the present invention
1 and the blade 12 are fastened by bolts 14 through washers 13 so that their combined body is axially symmetric.

When the torsional vibration horn 11 is fastened to the torsional vibration ultrasonic vibrator (not shown) by the connection screw 15 and excited, the torsional vibration mode of the horn 11 becomes 16 and the vibration mode of the blade 12 becomes 17 Becomes Vibration mode 17
Indicates that the blade 12 is vibrating in a torsional vibration mode on a plane perpendicular to the horn axis.

The primary and secondary bending vibration resonance frequencies of the blade 12 having a diameter of 50 mm and a thickness of 1 mm or less are as follows:
It becomes 22.7KHz or less by the simulation by the finite element method. Therefore, the resonance frequency of the torsional vibration horn 11
By setting the frequency to 27 KHz detuned from 22.7 KHz, the bending vibration of the blade 12 can be suppressed.

Generally, a dicing blade (diameter Dt)
It is ideal that the blade extension amount is 10 times the thickness (d).

Therefore, the diameter Dw of the washer 13 is set as follows: Dw ≦ Dt
When it is set to -20d, the blade 12 and the horn 11 are fastened with high rigidity, and it is recognized that the bending drive is suppressed.

Resin blade 12 having a diameter of 50 mm and a thickness of 1 mm
In the case of, good processing was obtained by setting the diameter of the washer 13 to 30 mm under the above conditions. In the case of resin blades 12 of the same type and the same diameter, even the blades 12 having a thickness of 0.3 mm can be machined by employing the same washers 13.

[0022]

As described above, according to the present invention, the blade is made capable of torsional vibration on a plane perpendicular to the torsional vibration axis,
When this blade is applied to hard and brittle material processing, it is possible to obtain an ultrasonic torsional vibration type blade drive device that can perform highly accurate groove width processing and minimize the occurrence of microcracks in a work.

That is, according to the present invention, it is possible to obtain an ultrasonic drive device for a blade capable of preventing a blade for processing hard and brittle material from having high rigidity and causing damage.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an ultrasonic torsional vibration type blade driving device of the present invention and a vibration mode of each part.

FIG. 2 is a schematic diagram showing a conventional ultrasonic bending vibration type blade driving device and vibration modes of respective parts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Torsional vibration horn 12 Blade 13 Washer 14 Fastening bolt 15 Connection screw 16, 17 Torsional vibration mode of horn and blade

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C069 AA01 BA04 BB00 BC01 CA02 CA03 CA05 EA02 EA05 5D107 AA11 BB01 CC10 DD11 FF03

Claims (2)

[Claims] 1. A structure in which an ultrasonic torsional vibration horn and a blade are coupled so that their combined body forms an axially symmetrical shape, and the torsional vibration resonance frequency of the horn is detuned from the flexural vibration resonance frequency of the blade. An ultrasonic torsional vibration type blade driving device, characterized in that: 2. The ultrasonic torsional vibration horn and the blade are connected via a washer having a diameter equal to the tip diameter of the horn,
2. The ultrasonic torsional vibration blade driving device according to claim 1, wherein the bolt is tightened, and the diameter of the washer is equal to or smaller than a value obtained by subtracting a value of 20 times the thickness of the blade from the diameter of the blade.