JP3102322B2 - Substrate processing method and apparatus using carbon dioxide laser light - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing method and apparatus using a carbon dioxide laser beam, and more particularly, to suppressing the rise in the temperature of cooling water and keeping the output of the carbon dioxide laser beam constant. The present invention relates to a substrate processing method using a carbon dioxide laser beam and a processing apparatus therefor.

[0002]

2. Description of the Related Art Recently, glass material substrates, magnetic material substrates,
The development of device products in which an electronic circuit, an optical circuit, and the like are mounted on a semiconductor material substrate and a dielectric material substrate has been actively performed.

[0003] As shown in FIG.
Is in the above-described substrate 41 or on the front (or back)
Several to several thousand are formed on the surface. Therefore, the substrate 41 must be cut in the last step to separate the respective devices 42. As the cutting / separating method, there is a method of performing dicing with a diamond blade along the cutting lines 43 and 44 on the substrate 41, or a method of performing scribing by irradiating a laser beam.

FIG. 7 shows a carbon dioxide gas laser device prototyped by the present inventor for cutting a substrate.

[0005] As shown in FIG.
1 is a carbon dioxide laser tube 2, a cooling means 23, and a light guide tube 1.
And 3. The carbon dioxide laser tube 2 housed in the box 3 has a double tube structure with one end closed, and a mixed gas (for example, CO ₂ :
N ₂ : He = gas mixed at a ratio of 8:18:74) G
_M is enclosed. Further, internal mirrors 4a and 4b as resonators are provided at both ends of the inner tube. Further, on the inner wall of the inner tube, electrodes 5a for discharge connected to the power supply circuit 6,
5b are provided at intervals. Cooling water W is introduced into the outer tube from a water circulator 8 as cooling means 23 via a cooling water introducing pipe 9a. The carbon dioxide gas laser tube 2 is cooled by the cooling water W, and thereafter, the cooling water W is circulated to the water circulator 8 through the cooling water discharge pipe 9b.

A part of the carbon dioxide laser light A oscillated between the internal mirrors 4a and 4b by applying a voltage between the electrodes 5a and 5b from the power supply circuit 6 is output from the internal mirror 4b. . The carbon dioxide laser light A output from the inner mirror 4b is
The propagation direction is bent by 90 degrees by the total reflection mirror 16 provided inside the light guide tube 13 at an angle of 45 degrees with respect to the optical axis. The carbon dioxide laser light A whose propagation direction is bent by 90 degrees is supplied to the condenser lens 1 provided at the end of the light guide tube 13.
The light is collected at 7. A carbon dioxide laser light irradiation port 18 is connected to an end of the light guide tube 13. Condensed carbon dioxide laser light A, the gas introduction pipe 18a formed in the carbon dioxide laser light irradiation port 18 is blown assist gas G _A from 18a, it is irradiated on the substrate 19 placed on the fixed base 20 . The fixed base 20 is placed on an XY moving device 21 and is moved in the X direction or the Y direction.

[0007]

However, when the carbon dioxide laser device 51 shown in FIG. 7 is used to cut or cut a glass substrate, a ceramic substrate, or the like, or to form a slit or a hole, the following problem occurs. The following problems occur.

(1) Since the exact output power of the carbon dioxide laser beam A cannot be known in advance or during operation, the reproducibility of processing is poor. That is, there are cases where cutting is possible and cases where cutting is not possible even when the cutting (or cutting) speed is kept constant. Also, even if cutting was possible, reproducibility such as smoothness of the cut surface and suppression of microcracks was extremely poor.

(2) Since reproducibility is extremely poor, processing costs are high.

[0010] A factor that deteriorates the reproducibility is a change in the output power of the carbon dioxide gas laser beam A due to a change in the temperature of the cooling water W that cools the carbon dioxide gas laser tube 2. Therefore, the relationship between the temperature rise of the cooling water W in the cooling water introduction pipe 9a and the output power of the carbon dioxide gas laser light A when the temperature control of the water circulator 8 was not performed was measured. The result is shown in FIG. Note that a in the figure indicates an output power curve of the carbon dioxide gas laser light A, and b in the figure indicates a temperature curve of the cooling water W.

[0011] As shown in FIG.
There is a relationship between the curve a and the curve b from about 2 hours 30 minutes after the start of operation of No. 1 that the output power of the carbon dioxide laser light A decreases as the temperature of the cooling water W increases. That is, the output power of the carbon dioxide gas laser beam A decreases by about 3.3 W with respect to the temperature rise of the cooling water W of 1 ° C., and a remarkable fluctuation of the output power of the carbon dioxide gas laser beam A is observed.

As described above, since the temperature rise of the cooling water W due to the continuous operation of the carbon dioxide gas laser device 51 greatly affects the decrease in the output power of the carbon dioxide gas laser light A, the temperature rise of the cooling water W is suppressed, and Means and method for keeping the output power of the gas laser light A constant are required.

Accordingly, an object of the present invention is to solve the above-mentioned problems, suppress the temperature rise of the cooling water, and maintain a constant output of the carbon dioxide laser beam. An object of the present invention is to provide a processing device.

[0014]

According to a first aspect of the present invention, a resonator is provided at both ends of a carbon dioxide laser tube in which a mixed gas containing carbon dioxide is sealed, and is provided in the carbon dioxide laser tube. A laser is oscillated between the above-mentioned resonators by applying a voltage between the electrodes to discharge, and a part of the laser-oscillated carbon dioxide laser light is output from one side of the above-mentioned resonator and irradiated on the substrate through the condenser lens. And
In the method of processing a substrate using a carbon dioxide laser beam for processing the substrate, 4 to 20% of the carbon dioxide laser beam output from the output-side resonator is irradiated between the resonator and the condenser lens. The light is reflected by a monitor light detection mirror provided at an angle to the axis, and the carbon dioxide laser reflected light reflected by the surface of the monitor light detection mirror is constantly monitored by monitor light detection means. Cooling water is circulated through cooling means provided around the outer periphery of the resonator or a part thereof, and the temperature of the cooling water is controlled to ± 0.1 ° C. or less with respect to a set value, and
The carbon dioxide laser reflected light detected by the
A control signal is sent to the cooling means so that the
The substrate is processed under feedback control .

According to a second aspect of the present invention, feedback control is performed by sending a control signal to a power supply circuit for applying a voltage between the electrodes so that the reflected carbon dioxide laser beam detected by the monitor light detecting means becomes constant. A method for processing a substrate using a carbon dioxide laser beam according to claim 1.

According to a third aspect of the present invention, the substrate is irradiated with the carbon dioxide laser light passing through the condenser lens while keeping the gas atmosphere of N ₂ , Ar, O ₂ , air or the like.
A substrate processing method using the carbon dioxide gas laser light according to claim 2 .

According to a fourth aspect of the present invention, resonators are provided at both ends of a carbon dioxide laser tube filled with a mixed gas containing carbon dioxide,
By applying a voltage between the electrodes provided in the carbon dioxide laser tube and discharging, laser oscillation occurs between the resonators, and a part of the laser-oscillated carbon dioxide laser light is output from one side of the resonator, In a substrate processing apparatus using a carbon dioxide laser beam for irradiating a substrate through a condenser lens and processing the substrate, a substrate is inclined at θ _{A with} respect to an optical axis between an output side resonator and the condenser lens. Monitor light detection mirror, and a part of the carbon dioxide gas laser light reflected on the surface of the monitor light detection mirror, and a monitor light detection means for outputting the detected signal,
A control unit for feeding back a signal output from the monitor light detection unit to a power supply circuit for applying a voltage between the electrodes, and an outer peripheral portion of the carbon dioxide laser tube and the resonator, or a portion surrounding the outer peripheral portion thereof; The cooling water circulating inside the cooling means is controlled to ± 0.1 ° C. or less with respect to the set value of the temperature of the cooling water.
The carbon dioxide gas detected by the monitor light detecting means.
Control signal to the cooling means so that the laser reflected light is constant.
The signal is sent and feedback controlled .

According to a fifth aspect of the present invention, a Brewster window is provided at a Brewster angle θ on the opposite side of the output side resonator, and the Brewster window is provided outside the Brewster window and on an extension of the optical axis. 5. A substrate processing apparatus using a carbon dioxide gas laser beam according to claim 4, wherein the substrate is provided with a grating.

According to a sixth aspect of the present invention, an optical shutter is provided between the output side resonator and the monitor light detecting mirror, or between the monitor light detecting mirror and the condenser lens, or both. A substrate processing apparatus using a carbon dioxide gas laser beam according to claim 4 provided.

According to the above-described method and apparatus, the following effects can be obtained.

According to the first aspect of the present invention, the mirror for detecting the monitor light capable of reflecting and extracting 4 to 20% of the carbon dioxide laser light is provided in the propagation path of the carbon dioxide laser light so as to be inclined. Monitoring can be performed at all times without reducing the output power of light. Also,
By keeping the temperature of the cooling water constant, laser oscillation
Long-period fluctuations of carbon dioxide laser light
Can be reduced, so
And the reproducibility when processing is improved. Furthermore,
Change the voltage applied to the electrodes and the temperature of the cooling water.
And the long-term fluctuation of the output power of the carbon dioxide laser light
Control and easily control short-term fluctuations due to disturbance
Can improve the reproducibility when processing.
Wear.

According to the second aspect of the present invention, by changing the voltage applied to the electrodes, it is possible to control the long-period fluctuation of the output power of the carbon dioxide laser beam and easily control the short-period fluctuation due to disturbance. Therefore, the reproducibility when processing can be improved.

According to the third aspect of the present invention, it is possible to keep the processed surface of the substrate clean and prevent adhesion of impurities.

According to the configuration of the fourth aspect of the present invention, the monitor light detecting mirror is provided in the propagation path of the carbon dioxide laser light at an angle, so that a part of the carbon dioxide laser light can be reflected and taken out. Since it is possible to constantly monitor, the output of the carbon dioxide laser light can be kept constant.

According to the structure of the fifth aspect of the present invention, the Brewster window is formed at a Brewster angle θ on the side opposite to the resonator on the output side, so that the carbon dioxide laser tube and the internal mirror are separated. Can be provided. Further, by providing the grating outside the Brewster window and on an extension of the optical axis, it is possible to reflect only light of at least one wavelength or light of a desired narrow wavelength band.

According to the sixth aspect of the present invention, an optical shutter is provided between the output-side resonator and the monitor light detecting mirror, or between the monitor light detecting mirror and the condenser lens, or both. Is provided and is controlled to be opened or closed by an electric control signal, whereby the propagation of the carbon dioxide gas laser light can be controlled.

[0027]

FIG. 1 is a block diagram showing an embodiment of the present invention.
Will be described. The same members as those in FIG. 7 are denoted by the same reference numerals.

As shown in FIG. 1, the carbon dioxide laser device 1
Are the carbon dioxide laser tube 2, the cooling means 23, and the light guide tube 13.
It is composed of The carbon dioxide laser tube 2 housed in the box 3 has a double tube structure with one end closed. At both ends of the inner tube of the carbon dioxide laser tube 2, internal mirrors 4a and 4b as resonators are provided. Further, discharge electrodes 5a and 5b connected to the power supply circuit 6 are provided at intervals on the inner wall of the inner tube. The outer tube of the carbon dioxide laser tube 2 and the water circulator 8, which is a cooling means 23 provided outside the box 3, are connected via a cooling water introduction pipe 9a and a cooling water discharge pipe 9b. The water circulator 8 is connected to the water temperature controller 7.

The opening side of the carbon dioxide laser tube 2 is connected to one end of the light guide tube 13. Inside the light guide tube 13,
A total reflection mirror 16 is provided at an angle of 45 degrees with respect to the optical axis of the carbon dioxide laser light A.
3 is provided at a right angle. At the other end of the light guide tube 13, a condenser lens 17 is provided, and a carbon dioxide gas laser beam irradiation port 18 having gas introduction tubes 18a, 18a.
Is connected.

A monitor light detection mirror 10 is provided between the output side internal mirror 4b and the total reflection mirror 16 at an angle (eg, 45 degrees) with respect to the optical axis of the carbon dioxide laser light A. The monitor light detection mirror 10 and the total reflection mirror 16
An optical shutter 14 connected to the optical shutter adjusting mechanism 15 is provided perpendicular to the optical axis of the carbon dioxide laser light D (the transmitted light of the carbon dioxide laser light A by the monitor light detection mirror 10).

A monitor light detecting means 11 is provided to monitor a part of the carbon dioxide laser light R reflected by the monitor light detecting mirror 10, and controls a detection signal B _O output by the monitor light detecting means 11. Control means 1
2 are provided.

The substrate 19 is placed on the fixed base 20, and the fixed base 2 is brought into close contact with the fixed base 20.
At 0, a substrate suction vacuum device 22 is formed. Fixed stand 2
An XY moving stage 21 is provided below the fixed base 20 so as to freely control 0 in the X direction and the Y direction.

Next, the method of the present invention will be described.

First, the electrodes 5a connected to the power supply circuit 6,
A voltage is applied to 5b to cause laser oscillation between the internal mirrors 4a and 4b, and the carbon dioxide laser light A is output from the internal mirror 4b on the output side. 4 to 20% of the carbon dioxide laser light A
Is reflected at a constant rate by the monitor light detecting mirror 10, and the carbon dioxide laser light R is monitored by the monitor light detecting means 11. The propagation of the carbon dioxide laser light D transmitted through the monitor light detection mirror 10 stops at the position of the optical shutter 14.

Next, the carbon dioxide laser light R monitored by the monitor light detecting means 11 is output as a detection signal B _O ,
Input to the control means 12. Further, the control means 12 has a reference signal _BF corresponding to the output power value of the carbon dioxide laser light A.
Enter The control means 12 compares and calculates the detection signal B _O and the reference signal _BF. If the output power of the carbon dioxide laser reflected light R is smaller than the reference signal _BF , the control signal C for increasing the voltage is fed back to the power supply circuit 6. Conversely, if the output power of the carbon dioxide laser reflected light R is large, the control signal C for lowering the voltage is fed back to the power supply circuit 6.

This process is repeated, and when the carbon dioxide laser beam A reaches a predetermined output power, the optical shutter adjusting mechanism 15 is controlled again to open the optical shutter 14 and the substrate 19 is irradiated with the carbon dioxide laser beam D. When irradiating the substrate 19 with the carbon dioxide laser beam D, the carbon dioxide laser beam
Blown gas inlet 18a, an assist gas G _A from 18a simultaneously. With keeping the blowing of the assist gas G _A the processed surface of the substrate 19 to clean, prevent adhesion of impurities.

By continuously irradiating the substrate 19 with the carbon dioxide laser beam D, the carbon dioxide laser tube 2 and the inner mirrors 4a, 4
A temperature fluctuation occurs due to the heat generation of b, and this temperature fluctuation causes a long-period fluctuation of the output power of the carbon dioxide gas laser beam D. Therefore, by using the water temperature controller 7, the output power of the carbon dioxide gas laser beam D is kept constant while the temperature fluctuation due to the heat generation of the carbon dioxide laser tube 2 and the internal mirrors 4a and 4b is kept constant.

Further, since the control signal C output from the control means 12 is always fed back to the power supply circuit 6, this feedback further suppresses the long-term fluctuation of the output power of the carbon dioxide laser light D.

The features of the carbon dioxide laser device of the present invention will be described below.

The first feature is that the water temperature of the cooling water W circulated from the water circulator 8 for cooling the outer periphery of the carbon dioxide gas laser tube 2 and the outer periphery of the inner mirrors 4a and 4b is controlled to a constant temperature by the water temperature controller 7. That's what we do.

By using the water temperature controller 7, the water temperature of the cooling water W is controlled to a set temperature ± 0.1 ° C. or less. Cooling water W
By controlling the water temperature to be equal to or lower than the set temperature ± 0.1 ° C., a long-period variation of the output power of the carbon dioxide laser light A can be suppressed. The set temperature of the cooling water W is 20 to 28
C. is desirable. According to an experimental study, when the set temperature of the cooling water W is controlled to 25 ° C. ± 0.1 ° C., for example, for a continuous oscillation output value of 100 W, the steady-state variation of the output power of the carbon dioxide gas laser beam is ± It can be reduced to 1W. On the other hand, the set temperature of the cooling water W is set to 20 ° C. ± 0.1
° C, the steady-state variation of the output power of the carbon dioxide laser beam is ±
It became 1.4W. That is, it is most desirable that the temperature be higher in the range of 20 to 28 ° C.

A second feature is that a monitor light detection mirror 10 for monitoring the output power of the carbon dioxide laser light A output from the internal mirror 4b is provided, and the monitor light detection mirror 10 generates the carbon dioxide laser light A. That is, the output power of the carbon dioxide laser reflected light R is monitored by the monitor light detecting means 11.

As described above, important points in monitoring the output power of the carbon dioxide laser reflected light R are (1) that the carbon dioxide laser light D and the carbon dioxide laser reflected light R are in a proportional relationship.

(2) If the carbon dioxide laser reflected light R is reflected too much, the output power of the carbon dioxide laser light D is reduced.

There are two points.

Therefore, a monitor light detecting mirror 10 in which the optical power reflectance is variously changed from 2 to 25% is manufactured, and the optical power reflectance satisfying both (1) and (2) is determined by using the apparatus shown in FIG. It was determined using The same members as those in FIG. 1 are denoted by the same reference numerals.

As a result, when the reflectivity is less than 4%, the output power of the carbon dioxide laser beam A is extremely small. Therefore, when the output power of the carbon dioxide laser beam A is changed from 40 to 140 W, the carbon dioxide laser beam D It was found that the proportional relationship with the gas laser reflected light R was not established. When the reflectance is 4% or more, the carbon dioxide laser light D
It has been found that a substantially proportional relationship holds between the laser beam and the carbon dioxide laser reflected light R. When the reflectivity is larger than 20%, the output power of the carbon dioxide gas laser reflected light R is increased, but the output power of the carbon dioxide gas laser light D is correspondingly reduced, which hinders the processing of the substrate 19.

In the case where the reflectance is larger than 20%, if the monitor light detecting mirror 10 is used for a long time, the monitor light detecting mirror 10 gradually generates heat due to the heat energy of the carbon dioxide laser light A. There is a problem that the inclination angle of the monitor light detecting mirror 10 is shifted, or the optical guide tube 13 is distorted and the optical axis of the carbon dioxide laser light A is shifted.

Therefore, it was found that the reflectance of the monitor light detecting mirror 10 is preferably in the range of 4 to 20%. For example, when the output power of the carbon dioxide laser light A is 140 W,
As a result of 5% of the reflected light being reflected by the monitor light detecting mirror 10, there is a proportional relationship between the output power (133 W) of the carbon dioxide laser light D and the carbon dioxide laser reflected light R. Also,
Even when the output power of the carbon dioxide laser light D is changed from 50 to 133 W by changing the voltage of the power supply circuit 6, the output power of the carbon dioxide laser light D and the output power of the carbon dioxide laser reflected light R are proportional. Have a relationship.

The third feature is that a reference signal _BF corresponding to the output power of the carbon dioxide gas laser beam D and a monitor light detection signal are provided so that the output power of the carbon dioxide gas laser beam D can always be controlled to be constant even with disturbance changes. That is, the output signal B _O of the means 11 is input to the control means 12, and the control signal C of the control means 12 is fed back to the power supply circuit 6.

As described above, the output power of the carbon dioxide laser light D is constantly kept constant by controlling the water temperature of the cooling water W to the set temperature ± 0.1 ° C. or less by the water temperature controller 7. . Further, the carbon dioxide laser light D
In order to suppress the fluctuation of the output power of the laser beam, the reflected power R of the carbon dioxide gas laser is detected and fed back to the power supply circuit 6 so that the value becomes constant, so that the total output power of the carbon dioxide laser light D is kept constant. It is.

Next, another embodiment will be described with reference to FIG. The same members as those in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 2, the basic configuration of the carbon dioxide laser device 31 of the present embodiment, which is completely the same as that of the carbon dioxide laser device 1 of the present invention, is different from that of the first embodiment.
Is fed back to the water temperature controller 7 and the power supply circuit.

The operation of the present embodiment will be described.

The control signal C of the control means 12 is transmitted to the water temperature controller 7.
Feedback to As a result, the control signal C of the control means 12 decreases the temperature of the cooling water W when the output power of the carbon dioxide laser reflected light R decreases with respect to the reference signal _BF corresponding to the desired output power value of the carbon dioxide laser light A. A signal to increase the water temperature of the cooling water W is sent to the water temperature controller 7 when the output power of the carbon dioxide laser reflected light R increases. That is, the carbon dioxide laser light A can be kept at a desired output power.

Alternatively, the control signal C of the control means 12 is fed back to both the water temperature controller 7 and the power supply circuit 6. As a result, the control signal C of the control means 12 decreases the temperature of the cooling water W when the output power of the carbon dioxide laser reflected light R decreases with respect to the reference signal _BF corresponding to the desired output power value of the carbon dioxide laser light A. Water temperature controller 7
To the power supply circuit 6
Conversely, when the output power of the carbon dioxide laser reflected light R increases, a signal for raising the water temperature of the cooling water W is sent to the water temperature controller 7 and a signal for lowering the voltage is sent to the power supply circuit 6.

That is, according to the carbon dioxide gas laser device 31 of the present embodiment, the carbon dioxide gas laser light A is set to a desired output power in a shorter time as compared with the case where the control signal C is fed back only to the power supply circuit 6. be able to.

The control means 12 is preferably a simple proportional control circuit or a proportional-integral circuit. Note that the output power of the carbon dioxide laser light A has a relatively slow and long-period fluctuation, so that the configuration of the control means 12 described above may be employed.

The carbon dioxide laser device 3 of the present embodiment
1 and the internal mirror 4a of the carbon dioxide laser device 1 of the present invention have a wavelength of 10.6 μm
μm) or a band-rejection mirror having a characteristic of selectively reflecting an optical signal in a desired narrow wavelength band of 10.6 μm. .

Further, another embodiment will be described with reference to FIG. The same members as those in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 3, the basic structure of the carbon dioxide laser device 32 of the present embodiment is exactly the same as that of the carbon dioxide laser device 1 of the present invention. Is provided. That is, the carbon dioxide laser device 32 of the present embodiment
Is provided with a Brewster window 25 at a Brewster angle θ on the opposite side of the internal mirror 4b.
Grating 26 outside the optical axis and on an extension of the optical axis.
Is provided. The grating 26 is connected to a grating adjusting mechanism 27.

The operation of this embodiment will be described.

First, by operating the power supply circuit 6 and applying a voltage to the electrodes 5 a and 5 b connected to the power supply circuit 6, laser oscillation occurs between the internal mirror 5 a and the Brewster window 25. The carbon dioxide laser light E ₁ generated by the laser oscillation has a variety of wavelengths, and a composite light polarized. The carbon dioxide gas laser beam E ₁ is incident on a Brewster window 25 provided at a Brewster angle θ at which the reflectance for the p-polarized component becomes zero.

The carbon dioxide laser beam E ₁ has various wavelengths and transmits through the Brewster window 25, and is a composite carbon dioxide laser beam E having only a p-polarized component.
It becomes ₂ . This carbon dioxide laser light E is incident on the grating 26 connected to the grating adjusting mechanism 27.

By adjusting the grating adjusting mechanism 27, one or a desired number of lights of various wavelengths are reflected. That is, the carbon dioxide laser light E
Numeral ₂ is reflected by the grating 26 and becomes light of one wavelength with only the p-polarized component or carbon dioxide laser light E that is a composite light of several desired wavelengths with only the p-polarized component.

The carbon dioxide laser light E passes through the monitor light detecting mirror 10 and becomes the carbon dioxide laser light F. By irradiating the substrate 19 with the carbon dioxide laser light F, the processing accuracy when cutting or cleaving the substrate 19 made of a nonmetallic material such as plastic, glass, or ceramics can be greatly improved. In addition, this makes it possible to smooth the cut surface or the fractured surface of the substrate 19 and to suppress the occurrence of microcracks.

An example of processing a glass substrate and a ceramic substrate using the carbon dioxide laser device shown in FIG. 1 will be described.

(Processing Example 1) Thickness 1 mm, length 80 m
m, alumina substrate of width 80 mm, length 8 by evaporative cutting
An experiment was performed in which a plate having a width of 0 mm and a width of 5 mm was processed. In the cutting process, the carbon dioxide laser beam D condensed by the condenser lens 17 is kept focused on the surface of the substrate, and N ₂ gas is supplied from the gas inlets 18a, 18a at a gas pressure of 3 kg / cm.
^The temperature of the cooling water W is kept at 25 ° C. by the water temperature controller 7 and the output power of the carbon dioxide gas laser light A is 5
% As the carbon dioxide laser reflected light R
1 and the feedback to the power supply circuit 6 was performed based on the monitor signal. As a result, cutting speed 8m
At m / sec, an alumina plate having a very smooth cut surface could be obtained with good reproducibility.

(Working Example 2) As in Working Example 1, the thickness 1
An experiment was conducted in which a wormlite substrate having a length of 50 mm and a width of 50 mm was cut into a 50 mm long and 5 mm wide plate by evaporative cutting. As a result, a very uniform and smooth cut surface could be obtained at a cutting speed of 5 to 8 mm / sec.

(Processing Example 3) As in Processing Example 1, a borosilicate glass substrate having a thickness of 1.1 mm, a length of 550 mm and a width of 650 mm was cut by evaporation to a length of 550 mm and a width of 50 mm.
An experiment for processing into a mm plate was conducted. As a result, at a cutting speed of 5 mm / sec, little variation in the cutting of the borosilicate glass substrate was observed, and the cut surface was smooth and the borosilicate glass plate without micro cracks could be cut with good linearity. Also, the fluctuation of the output power of the carbon dioxide gas laser reflected light R during the cutting for about 2 hours is as follows.
The set value was ± 0.5 W or less.

An example of processing a glass substrate and a ceramic substrate using the carbon dioxide laser device shown in FIG. 3 will be described.

(Processing Example 4) Thickness 1.5 mm, length 50
An experiment was conducted in which an alumina substrate having a width of 150 mm and a width of 150 mm was processed into a plate having a length of 50 mm and a width of 5 mm by evaporative cleavage. The cleaving process is performed by setting the substrate 19 to a focal length F _O + an offset amount Fd.
(10 mm) apart from the condenser lens 17, N ₂ gas was blown in at a pressure of about 3 kg / cm ² as an assist gas, and the output power of the carbon dioxide gas laser light D was set to 120 W. As a result, the cutting speed is 25 to 30 mm / sec.
In the range of c, the alumina plate having a smooth cross section and no microcracks was able to be cut with good linearity. Further, the fluctuation of the output power of the carbon dioxide gas laser reflected light R during the cutting for about 1 hour 30 minutes is set to ± 1
Since it was controlled to be W or less, the cutting could be performed with extremely high reproducibility.

(Processing Example 5) As in Processing Example 4, an alkali-free glass substrate having a thickness of 1.1 mm, a length of 550 mm, and a width of 650 mm was cut by evaporation to a length of 550 mm and a width of 50 mm.
An experiment for processing into a mm plate was conducted. However, N ₂ gas as an assist gas was blown at a pressure of about 0.5 kg / cm ² . As a result, in the range of the cutting speed of 28 to 34 mm / sec, it was possible to cut the alkali-free glass plate having a smooth cut surface and no micro cracks.

Although the embodiment of FIGS. 1, 2 and 3 has been described with reference to a single carbon dioxide laser tube 1, the number of carbon dioxide laser tubes 1 is not limited to one. That is, the multi-mixed gas G _M is sealed a carbon dioxide laser tube 1 will be placed in a straight line in the cascade, or the total reflection mirror 16 provided to be inclined by 45 ° relative to the optical axis into two combined U-shaped They may be arranged so as to form a path, or may be arranged by forming a longer multipath by combining U-shaped multipaths. By connecting the carbon dioxide gas laser tubes 1 in a cascade as described above, the output power of the carbon dioxide laser light D can be further increased, and an output power of several tens of watts to several hundreds of watts can be easily obtained.

In the embodiments shown in FIGS. 1, 2 and 3, the optical shutter 14 is disposed between the monitor light detecting mirror 10 and the condenser lens 17; It may be provided between the monitor light detection mirror 10 or both.

Further, in the embodiments shown in FIGS. 1, 2 and 3, the monitor light detecting mirror 10 is a band-rejection type mirror so as to extract 4 to 20% of the output power of the carbon dioxide gas laser light A. May be. Thus, the monitor light detecting mirror 10, the total reflection mirror 1
6. Since the influence of the characteristics due to the wavelength dependence of the condenser lens 17 is greatly suppressed, the proportional relationship between the output power of the carbon dioxide laser light A and the carbon dioxide laser reflected light R becomes extremely good.

[0077]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) Since the monitor light detecting mirror is provided in the propagation path of the carbon dioxide laser light at an angle, a part of the carbon dioxide laser light can be reflected at a constant rate and can be constantly monitored.

(2) By controlling the power supply circuit and / or the water temperature controller so that the output power of the carbon dioxide laser reflected light reflected by the monitor light detecting mirror is constant, the carbon dioxide laser light is controlled. The output power can be controlled to be constant.

[Brief description of the drawings]

FIG. 1 is a diagram showing a carbon dioxide laser device of the present invention.

FIG. 2 is a view showing another embodiment of the carbon dioxide laser device of the present invention.

FIG. 3 is a diagram showing still another embodiment of the carbon dioxide laser device of the present invention.

FIG. 4 is a diagram showing an example of an apparatus for explaining the present invention.

FIG. 5 is a diagram showing the relationship between the temperature of cooling water and the output power of carbon dioxide laser light.

FIG. 6 is a diagram illustrating a method of cutting and separating a substrate.

FIG. 7 is a view showing a conventional carbon dioxide laser device.

[Explanation of symbols]

 2 Carbon dioxide laser tube 4a, 4b Internal mirror (resonator) 5a, 5b Electrode 6 Power supply circuit 10 Mirror for monitor light detection 11 Monitor light detection means 12 Control means 14 Optical shutter 17 Condensing lens 19 Substrate 23 Cooling means 25 Brewster window 26 Grating A, D Carbon dioxide laser light C Control signal R Carbon dioxide laser reflected light W Cooling water θ Brewster angle

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 26/00-26/42 H01S 3/00-3/30

Claims (6)

(57) [Claims] 1. A resonator is provided at both ends of a carbon dioxide laser tube in which a mixed gas containing carbon dioxide gas is sealed, and a voltage is applied between electrodes provided in the carbon dioxide laser tube to cause discharge. A laser is oscillated, and a part of the laser-oscillated carbon dioxide laser light is output from one side of the resonator and irradiated to the substrate through a condenser lens, and the substrate is processed using the carbon dioxide laser light to process the substrate. 4-20% of the carbon dioxide laser light output from the output side resonator is reflected by a monitor light detection mirror provided between the resonator and the condenser lens and inclined with respect to the optical axis. The reflected light of the carbon dioxide gas laser reflected by the surface of the monitor light detecting mirror is constantly monitored by the monitor light detecting means, and the outer periphery of the carbon dioxide laser tube and the resonator, or The part of the cooling water is circulated in the internal cooling means provided by surrounding the controls below ± 0.1 ° C. The temperature of the cooling water with respect to the set value, the monitoring light detection
The reflected carbon dioxide laser light detected by the
Control signal to the cooling means
A method of processing a substrate using carbon dioxide laser light, wherein the substrate is processed while performing back control . 2. A feedback control by sending a control signal to a power supply circuit for applying a voltage between the electrodes so that the reflected carbon dioxide laser light detected by the monitor light detecting means becomes constant. A method for processing a substrate using carbon dioxide laser light. 3. The carbon dioxide gas passing through the condenser lens.
Laser light in a gas atmosphere such as N ₂ , Ar, O ₂ , air, etc.
3. The method of processing a substrate using a carbon dioxide gas laser beam according to claim 1, wherein the substrate is irradiated with the carbon dioxide gas laser beam. 4. Carbon dioxide containing a mixed gas containing carbon dioxide gas.
Resonators were provided at both ends of the gas laser tube, and
Discharge by applying voltage between electrodes provided in the tube
Laser oscillation between the resonators,
A part of the oscillated carbon dioxide laser light is
And irradiates the substrate through a condenser lens.
Substrate processing equipment using carbon dioxide laser light
Between the output side resonator and the condenser lens.
Monitor light detection mirror provided at θ _A
And the above reflected on the surface of the monitor light detection mirror
While detecting a portion of the carbonated gas laser light, and the detection
Monitor light detection means for outputting a detected signal, and the monitor light detection means.
Applying a signal output from the output means and applying a voltage between the electrodes
Control means for feeding back to a power supply circuit for
The outer peripheral portion of the acid gas laser tube and the resonator, or
Cooling means provided so as to surround a part of the
The cooling water circulating inside the cooling means depends on the temperature of the cooling water.
The temperature is controlled to ± 0.1 ° C or less with respect to the
The CO2 laser reflected light detected by the detection means is constant
Control signal is sent to the cooling means so that
Carbon dioxide gas, characterized in that it is controlled by feedback
Substrate processing equipment using the light. 5. A blue light-emitting device on the opposite side of the output side resonator.
A blue star window is provided at a star angle θ, and
Outside the blue star window and on the extension of the above optical axis
The substrate processing apparatus using a carbon dioxide laser beam according to claim 4, further comprising a grating . 6. The output side resonator and the monitor light detection.
Between the monitor mirror or the monitor light detection mirror and
An optical shutter between the condenser lens or both
A substrate processing apparatus using a carbon dioxide laser beam according to claim 4 .