KR100659478B1 - Laser processing method and processing device - Google Patents

Abstract

The laser which passed this through-hole so that the cross section of a laser beam may be shape | molded with the mask 5 which has a through-hole, and the through-hole of this mask forms on the surface of the to-be-processed object 12 The beam is focused on the lens 6 and is incident on the surface of the workpiece. By operating the laser beam passing through the lens so that the incidence position of the laser beam moves on the surface of the workpiece, and forming the through hole on the surface of the workpiece during scanning of the laser beam. This object is processed. Thereby, high quality laser processing can be performed efficiently.

Description

Laser processing method and processing device

The present invention relates to a laser processing method and a laser processing apparatus for performing processing by irradiating a laser beam to a processing object.

9 is a schematic view showing a conventional laser processing apparatus for forming grooves.

The pulsed laser beam is emitted from the laser light source 51 at a frequency of 1 Hz, for example. The laser beam becomes homogeneous (top flat) in the pulse energy density of the beam cross section in the homogenizer 52, and then, for example, in the mask 53 having a circular through hole, the cross-sectional shape becomes circular. It is structured. The light is reflected by the reflecting mirror 54 and enters the substrate 56 via the condenser lens 55. The substrate 56 is, for example, a substrate on which an ITO film is formed on a glass substrate. The laser beam is incident on the ITO film of the substrate 56. The beam spot of the laser beam on the surface of the ITO film is circular, for example, having a diameter of 0.2 mm. The substrate 56 is placed on the XY stage 57. The XY stage 57 can move the incident position of a pulsed laser beam in the surface on the board | substrate 56 by moving the board | substrate 56 in a two-dimensional plane.

First, the XY stage 57 is moved so that a pulse laser beam is irradiated to the board | substrate 56 at a 50% overlap rate, and a groove | channel is formed in the ITO film | membrane of the board | substrate 56. FIG. Here, the overlap ratio means the ratio of the moving distance in the radial direction of the circle per one shot of the pulse laser beam to the diameter of the circle.

10A is a schematic plan view of a substrate 56 in which a continuous hole is made by a laser beam irradiated at a 50% redundancy, and a groove is formed in the ITO film. The opening of the groove is shown by the thick line. Grooves are formed as a result of successive openings of the shape depending on the beam spot of the laser beam incident on the ITO film. For this reason, the perimeter of the opening along the longitudinal direction of the groove has irregularities due to a part of the outer circumference of the circular beam spot. In addition, when the frequency of the laser beam irradiated is 1 Hz and the beam spot of the laser beam on the ITO film | membrane of the board | substrate 56 is circular with a diameter of 0.2 mm, a processing speed will be 100 mm / s. Mainly regulated and constrained by the operation speed of the XY stage 57 to increase the processing speed by more than this cannot be adopted in consideration of the uniformity of the processing shape.

In order to make the periphery of the opening of the groove | channel formed in an ITO film | membrane close to linear form, the method of increasing an overlap rate is used. For example, a groove is formed on the ITO film of the substrate 56 by moving the XY stage 57 so that a pulse laser beam is irradiated at a 90% overlap rate.

10B is a schematic plan view of a substrate 56 in which a continuous hole is made by a laser beam irradiated at a 90% redundancy and a groove is formed in the ITO film. Similarly to Fig. 10A, the openings of the grooves are indicated by thick lines. The perimeter of the opening along the longitudinal direction of the groove is close to a straight line. However, since the laser beam is irradiated at a 90% redundancy, the processing speed is 1/5, that is, 20 mm / s when the redundancy is 50%. Although the shape of the opening can be improved, the time efficiency of processing is deteriorated.

FIG. 11 is a schematic cross-sectional view of the substrate 56 cut along the PQ line in FIG. 10A. Grooves are formed in the ITO film formed on the glass substrate. The side surface of the groove is inclined with respect to the surface of the substrate 56. It is preferable that the groove has a side shape that stands up more straight.

An object of the present invention is to provide a laser processing method and a laser processing apparatus which can perform high quality processing with high time efficiency.

According to the consistent point of this invention, the laser beam which passed this through-hole was formed so that the cross section of a laser beam may be shape | molded with the mask which has a through-hole, and the through-hole of this mask forms on the surface of a to-be-processed object. A process of condensing with a lens and making it incident on the surface of the workpiece, scanning the laser beam that has passed through the lens so that the incident position of the laser beam moves on the surface of the workpiece; There is also provided a laser processing method having a step of processing the object by forming the through-holes on the surface of the object during scanning of the beam.

By scanning the laser beam so that the through-holes of the mask are always formed on the surface of the object to be processed, high quality processing can be performed with high time efficiency. Deterioration of the processing quality due to blurring caused by scanning of the laser beam can be prevented.

According to another aspect of the present invention, the laser beam focused by the lens is incident on the surface of the object to be processed, and the laser beam is scanned so that the incident position of the laser beam moves on the surface of the object to be processed. As a step of processing the object to be processed, there is provided a laser processing method having a step of scanning the laser beam such that the optical path length of the laser beam from the lens to the surface of the object is not changed.

By maintaining a constant optical path length from the lens to the processing position on the object to be processed, scanning a laser beam, for example, always focuses on the object to be processed, enables high quality laser processing with high time efficiency.

Furthermore, according to another aspect of the present invention, a mask having a laser light source for emitting a laser beam, a support for supporting the object to be processed, a through hole for shaping the cross section of the laser beam emitted from the laser light source, A condenser lens for condensing the laser beam whose cross section is shaped by the mask, the through-holes of the mask to form an image on the surface of the object to be supported by the support, and a laser beam condensed by the condenser lens from outside A beam scanner which is controlled to scan in the at least one dimensional direction on the surface of the object, a moving mechanism which moves the mask and the condenser lens under control from the outside, scanning by the beam scanner, A laser processing apparatus having a control device for synchronizing movement of the mask and the condenser lens by the moving mechanism is provided.

By using this laser processing apparatus, high quality laser processing can be performed with high time efficiency by displacing the mask and the condenser lens in synchronization with the scanning of the beam.

According to another aspect of the invention, (e) the step of condensing the laser beam with a lens and incident on the surface of the object, and (f) the position of the object when the incident position of the laser beam to the object is moved Moving the incident position of the laser beam within the surface of the workpiece while moving the lens so as to suppress the variation caused by the movement of the incident position of the pulse energy density or power density of the laser beam on the surface of the laser beam; There is provided a laser processing method comprising a.

By moving the lens to equalize the pulse energy density or power density of the laser beam irradiated to the surface to be processed, constant processability is maintained over a large area of the surface to be processed.

According to another aspect of the invention, the laser beam is focused on the lens to be incident on the surface of the workpiece, and when the incident position of the laser beam on the workpiece is moved, the beam on the surface of the workpiece There is provided a laser processing method comprising the step of moving the incident position of a laser beam within the surface of the workpiece while moving the lens so as to suppress the area of the spot from fluctuating due to the movement of the incident position.

By shifting the lens to equalize the area of the beam spot of the laser beam irradiated onto the surface to be processed, the uniformity of the pulse energy density or the power density on the substrate is attained, so that a constant processability is maintained over a large area of the surface to be processed.

According to another aspect of the present invention, a laser light source for emitting a laser beam, a support mechanism for supporting a workpiece, a lens for condensing a laser beam emitted from the laser light source, and a direction in which the laser beam is emitted from the lens The laser beam is incident on the surface of the object to be supported by the support mechanism, the beam scanner moves the incident position of the laser beam within the surface of the object, receives a control signal from the outside, The lens so as to suppress the change in the pulse energy density or the power density of the laser beam on the surface of the workpiece when the moving mechanism for moving and the beam scanner move the incident position of the laser beam on the surface of the workpiece; A laser processing apparatus having a control device for controlling the moving mechanism to move the position of is provided.

By moving the lens to equalize the pulse energy density or power density of the laser beam irradiated to the surface to be processed, constant processability is maintained over a large area of the surface to be processed.

According to another aspect of the present invention, a laser light source for emitting a laser beam, a support mechanism for supporting a workpiece, a lens for condensing a laser beam emitted from the laser light source, and a direction in which the laser beam is emitted from the lens The laser beam is incident on the surface of the object to be supported by the support mechanism, the beam scanner moves the incident position of the laser beam within the surface of the object, receives a control signal from the outside, When the moving mechanism and the beam scanner move the incident position of the laser beam on the surface of the object to be processed, the position of the lens is moved so as to suppress the variation of the area of the beam spot on the surface of the object to be changed. A laser processing apparatus having a control device for controlling the moving mechanism is provided.

By shifting the lens to equalize the area of the beam spot of the laser beam irradiated onto the surface to be processed, the uniformity of the pulse energy density or the power density on the substrate is attained, so that a constant processability is maintained over a large area of the surface to be processed.

According to another aspect of the invention, (g) the step of condensing the laser beam with a lens and incident on the surface of the workpiece, and (h) when the position of incidence of the laser beam on the workpiece is moved, The incident position of the laser beam is adjusted while adjusting the power of the laser beam with a variable attenuator so as to suppress the variation due to the movement of the incident position of the pulse energy density or power density of the laser beam on the surface of the laser beam. There is provided a laser processing method comprising the step of moving within the surface of a.

By uniformizing the pulse energy density or power density of the laser beam irradiated to the surface to be processed using a variable attenuator, constant workability is maintained over a large area of the surface to be processed.

According to another aspect of the present invention, a laser light source for emitting a laser beam, a support mechanism for supporting a workpiece, a lens for condensing a laser beam emitted from the laser light source, and a direction in which the laser beam is emitted from the lens The laser beam is incident on the surface of the object to be supported by the support mechanism, the beam scanner moves the incident position of the laser beam within the surface of the object, and receives a control signal from the outside. A variable attenuator for attenuating power at a variable attenuation rate and a pulse energy density or power density of the laser beam on the surface of the workpiece change when the beam scanner moves the incident position of the laser beam on the surface of the workpiece. To control the variable attenuator to adjust the power of the laser beam to suppress The laser processing apparatus is provided.

By uniformizing the pulse energy density or power density of the laser beam irradiated to the workpiece surface by using a variable attenuator, constant machinability is maintained over a large area of the workpiece surface.

According to another aspect of the present invention, there is provided a laser light source for emitting a laser beam, a support mechanism for supporting an object, a first lens for converging or diverging the laser beam emitted from the laser light source; And a laser beam supported by the support mechanism by changing the advancing direction of the second lens into which the laser beam passing through the first lens is incident and condensing the incident laser beam, and the laser beam emitted from the second lens. A beam scanner for entering the surface of the processed object and moving the incident position of the laser beam within the surface of the object, a moving mechanism for receiving the control signal from the outside and moving the first lens, and the beam scanner When the incident position of the laser beam is moved on the surface of the workpiece, the pulse energy density or power density of the laser beam on the surface of the workpiece changes. NA1 has a control device for controlling the moving mechanism to move the position of the first lens so as to be suppressed, and the numerical aperture of this second lens with respect to the laser beam incident on the second lens is NA1. When the numerical aperture of the second lens with respect to the laser beam passing through the second lens is NA2, a laser processing apparatus having NA1 / NA2 of 2 or more is provided.

By moving the first lens to equalize the pulse energy density or power density of the laser beam irradiated to the surface to be processed, constant processability is maintained over a large area of the surface to be processed. Furthermore, by shortening the moving distance of the first lens, it is possible to speed up processing and to increase high precision.

According to another aspect of the present invention, a laser light source that emits a laser beam, a support mechanism for supporting a processing object, a through hole, and a laser beam emitted from the laser light source enters the through hole, and the A beam end face shaping machine capable of changing the length in one direction of the laser beam end face passing through the through hole, a lens for condensing the laser beam emitted from the beam end face shaping machine, and a light emitted from the lens A beam scanner for changing the advancing direction of the laser beam, causing the laser beam to enter the surface of the workpiece supported by the support mechanism, and moving the incident position of the laser beam within the surface of the workpiece; When the position of incidence of the laser beam is shifted on the surface of the surface, the beam cross-sectional shaper changes the shape of the beam spot on the surface of the object The laser processing apparatus having a control device for controlling the beam shaper is provided with a cross-section, so as to suppress.

Since the beam spot shape is suppressed from fluctuating when the machining position moves, constant machinability is maintained over a large area of the workpiece surface.

According to another aspect of the present invention, a laser light source for emitting a laser beam, a support mechanism for supporting a workpiece, a lens for condensing a laser beam emitted from the laser light source, and a direction in which the laser beam is emitted from the lens The laser beam is incident on the surface of the object to be supported by the support mechanism and the incident position of the laser beam is moved within the surface of the object, and the laser beam exiting the beam scanner is There is provided a laser processing apparatus, which is arranged in an optical path until incident on and has a through hole, and has a proximity mask for injecting a laser beam passing through the through hole into a workpiece.

By performing a laser processing using a proximity mask using a beam scanner that changes the traveling direction of the laser beam, high precision processing can be performed at high speed.

According to another aspect of the invention, the process of adjusting the spreading angle of the laser beam emitted from the laser light source, and while changing the advancing direction of the laser beam adjusted to have the predetermined spreading angle, in parallel with the surface of the workpiece The shape of the through-hole is arranged by a predetermined distance from the surface, irradiates the laser beam to a proximity mask having a through-hole, and enters the laser beam passing through the through-hole into the surface of the object to be processed. The process of transferring the surface of the object to be processed, the precision at which the shape of the through hole is transferred to the surface of the object, and the spread of the laser beam are performed at least one of the predetermined spreading angle and the predetermined distance. And a step of setting on the basis of a relationship obtained in advance with respect to an angle and a distance between the proximity mask and the surface of the workpiece. This ball method is provided.

By performing a laser processing using a proximity mask using a beam scanner that changes the direction in which the laser beam travels, high-precision processing can be performed at high speed. Furthermore, based on the previously obtained numerical relationship between the transfer accuracy and the spread angle and the proximity gap of the laser beam, the proximity gap and the spread angle can be easily selected when the machining is to be performed with the desired transfer accuracy. .

According to another aspect of the present invention, a laser beam source that emits a continuous wave laser beam, a support mechanism for supporting an object to be processed, and a laser beam emitted from the laser beam source enter and are given from the outside. On the basis of the signal, a laser beam having an optical system capable of switching whether or not the incident laser beam is emitted or not emitted, and a rectangular through hole, and the optical beam emitted in the traveling direction to the through hole is provided to the through hole. A lens which enters and forms a cross section of the laser beam, a lens that condenses the laser beam emitted from the mask, and forms a rectangular through hole of the mask on the surface of the object to be supported by the support mechanism; Based on a control signal given from the outside, the support mechanism is moved, and the laser beam exiting the lens A axis parallel to the optical axis of the laser beam passing through the through hole of the mask, based on a moving mechanism capable of moving the position incident on the water within the surface of the workpiece and a control signal given from the outside. A mask rotating mechanism for rotating the circumference, and controlling the optical system so that the optical system emits the laser beam in a predetermined direction at a predetermined timing, and the moving mechanism moves the incident position of the laser beam into the object to be processed in the first direction; The mask rotating mechanism rotates the mask to process the rectangular through hole before the moving mechanism is controlled to move, and the moving mechanism moves the incident position of the laser beam on the object to be processed in this first direction. The mask rotation mechanism is arranged so that the side with the image on the surface of the object is parallel to the first direction. A laser processing apparatus having a controlling device for controlling is provided.

The surface of the object can be irradiated with a continuous wave laser beam to form a linear pattern (line), and a pulsed laser beam is cut out from the continuous wave laser beam and irradiated to easily detect a discrete pattern of dots. Can be formed. By moving the irradiation position of the laser beam parallel to any side of the rectangular beam spot of the laser beam on the surface of the object to be processed, the shape of the line and the dot can be formed into a rectangle.

According to another aspect of the present invention, (i) a step of injecting a laser beam of a continuous wave emitted from a laser light source into an optical system which can switch in which traveling direction the incident laser beam is emitted or not emitted; and (j A process of forming a cross section by injecting a laser beam emitted from the optical system in a traveling direction into a mask having a rectangular through hole, condensing it with a lens, and forming an image of the through hole on the surface of the workpiece. And (k) a step of moving the image of the through-hole on the surface of the object in a direction parallel to the side where the image is present. In forming a suitable pattern, in the step (i), the laser beam is intermittently emitted from a certain traveling direction from the optical system, and the surface of the object is processed. When forming a pattern of shapes, In the above step (i), the laser processing method of the laser beam in a direction which proceeds from the optical system is to continuously emitted in is provided.

The surface of the object can be irradiated with a continuous wave laser beam to form a linear pattern (line), and a pulsed laser beam is cut out from the continuous wave laser beam and irradiated to easily detect a discrete pattern of dots. Can be formed. By moving the irradiation position of the laser beam parallel to any side of the rectangular beam spot of the laser beam on the surface of the object to be processed, the shape of the line and the dot can be formed into a rectangle.

According to another aspect of the present invention, there is provided a support mechanism for supporting a workpiece, a first laser light source for emitting a pulsed laser beam, a second laser light source for emitting a continuous wave laser beam, and a workpiece for being supported by the support mechanism. An optical system for irradiating a surface with a pulsed laser beam emitted from the first laser light source and a continuous wave laser beam emitted from the second laser light source so that the beam spot of the pulsed laser beam is included inside the beam spot of the continuous wave laser beam; A laser processing apparatus having a moving mechanism for moving a beam spot of a pulsed laser beam and a continuous wave laser beam on a surface of a workpiece supported by the support mechanism is provided.

A continuous wave laser beam is first irradiated with preheating to a certain to-be-processed area on the surface of the object to be processed, and then the pulse laser beam is irradiated. It becomes easy to selectively process the surface layer of the said process area | region.

According to another aspect of the present invention, there is provided a step of (n) emitting a pulsed laser beam from a first laser light source, and emitting a continuous wave laser beam from a second laser light source, and (o) a base layer and a base layer. The above-mentioned workpiece is formed on the surface of the workpiece to be defined on the surface of the object to be formed on the surface and having a surface layer formed of a material which is harder to be processed by laser irradiation than the material of the underlying layer. Irradiating the continuous wave laser beam emitted from the laser light source to give preheating, and then irradiating the pulsed laser beam emitted from the first laser light source to the processing point to form holes in the surface layer of the object to be processed. A laser processing method is provided.

A continuous wave laser beam is first irradiated with preheating, and then a pulse laser beam is irradiated to perform any processing on the surface of the object to be processed, thereby making it easier to selectively process the surface layer of the processing area. .

1 is a schematic diagram of a laser processing apparatus for performing a laser processing method according to a first embodiment of the present invention.

2 is a schematic view showing an optical path of a laser beam in the laser processing apparatus for performing the laser processing method according to the first embodiment.

3 (A) and 3 (B) are plan views showing an outline of a substrate processed by irradiation of a laser beam.

Fig. 4A is an example of the through-hole of the mask, and Fig. 4B is a schematic diagram showing the hole drilled in the substrate when the through-hole shown in Fig. 4A is formed on the substrate.

FIG. 5A is a schematic graph showing the energy density per pulse in the cross section of the pulsed laser beam emitted from the laser light source, and FIG. 5B shows that the pulse energy density distribution is converted by the conical optical system. It is a schematic graph which shows the energy density per pulse in the cross section of the completed pulse laser beam, FIG. 5 (C) shows the hole processed by the pulse laser beam which has the pulse energy density distribution shown in FIG. 5 (B). A schematic cross section of the.

6 is a schematic view of a laser processing apparatus that performs a laser processing method according to a modification of the first embodiment.

7 is a schematic view showing an optical path adjusting mechanism.

8 (A) and 8 (B) are schematic diagrams showing a conveyance mechanism.

9 is a schematic diagram of a conventional laser scribing apparatus.

10 (A) and 10 (B) are schematic plan views of a substrate processed with a conventional laser scribing apparatus.

11 is a schematic cross-sectional view of a substrate processed with a conventional laser scribing apparatus.

12 (A) is a schematic diagram of a laser processing apparatus for performing the laser processing method according to the second embodiment, and FIG. 12 (B) is a schematic diagram of a laser processing apparatus for performing a laser processing method according to the modification of the second embodiment. to be.

Fig. 13 is a schematic diagram showing an optical path of a laser beam in the laser processing apparatus for performing the laser processing method according to the second embodiment.

14 is a schematic view showing an optical path of a laser beam in a laser processing apparatus that performs a laser processing method according to a modification of the second embodiment.

Fig. 15A is a schematic diagram of a laser processing apparatus for performing the laser processing method according to the third embodiment, and Fig. 15B is a schematic diagram showing another configuration example of the primary condensing lens.

16 is a schematic view showing a configuration example of a secondary condensing lens.

17 is a schematic diagram of a laser processing apparatus that performs the laser processing method according to the fourth embodiment.

Fig. 18A is a schematic view of the aperture rotated by the aperture inclination mechanism as seen from the rotation axis direction of the aperture inclination mechanism, and Fig. 18B shows the aperture rotated by the aperture inclination mechanism. Fig. 18C is a schematic view of the aperture rotated by the aperture inclination mechanism and the aperture rotating mechanism as seen from the optical axis direction of the laser beam.

19 is a schematic diagram of a laser processing apparatus that performs the laser processing method according to the fifth embodiment.

20 is a plan view of a substrate on which an image of a through hole is projected, showing a result of a simulation regarding transfer accuracy in a laser processing method using a proximity mask.

Fig. 21 is a graph schematically showing the relationship that the spread angle and the proximity gap of the laser beam satisfy when processing is performed at a certain transfer accuracy.

Fig. 22A is a schematic diagram of a laser processing apparatus for performing the laser processing method according to the sixth embodiment, and Fig. 22B is a schematic sectional view of the substrate.

FIG. 23 is an example of a timing chart of an instrument signal and a laser beam in the case of performing laser processing using the laser processing apparatus according to the sixth embodiment.

FIG. 24A is a schematic plan view of a substrate on which lines are formed, and FIG. 24B is a schematic plan view of a substrate on which dots are formed.

25 is a schematic view showing a mask rotating mechanism supporting a mask.

Fig. 26 is a schematic plan view of a substrate on which lines are formed using a mask rotating mechanism.

FIG. 27A is a schematic diagram of a laser processing apparatus for performing the laser processing method according to the seventh embodiment, and FIG. 27B is a schematic cross-sectional view of the substrate.

28A, 28B, and 28C are plan views of the substrate for explaining the positional relationship between the processing point and the beam spot.

29 is a schematic plan view of a substrate on which lines are formed without using a mask rotating mechanism.

1 is a schematic diagram of a laser processing apparatus for performing a laser processing method according to a first embodiment of the present invention.

From the Nd: YAG laser oscillator including the laser light source 1, for example, a wavelength conversion unit, triple harmonics (wavelength 355 nm) of the Nd: YAG laser are emitted at a pulse energy of 1 mJ / pulse and a pulse width of 50 ns. The laser beam enters the conical optical system 4 via the variable attenuator 2 for adjusting the pulse energy, and the expander 3 for expanding the beam diameter and outputting as parallel light. The conical optical system 4 includes a pair of conical lenses 4a and 4b. The pair of conical lenses 4a and 4b are, for example, homogeneous, and are arranged so that the bottom faces thereof face each other. The laser beam is incident on the conical lens 4a from the axial direction of the staff weight so that the center of the beam cross section overlaps the apex of the staff weight portion, and exits from the cone lens 4b. The conical optical system 4 converts the beam profile of the incident laser beam so that the intensity is weak at the center of the beam cross section and strong at the periphery. This will be described later. As for the conical optical system 4, a convex lens may be used instead of the conical lens 4b on the emitting side of the laser beam.

The laser beam emitted from the conical optical system 4 passes through, for example, a mask 5 having a rectangular through hole and an objective lens 6 for forming a rectangular through hole of the mask 5 on the substrate 12. The mask 5 and the objective lens 6 are moved in a direction parallel to the advancing direction of the laser beam by the voice coil mechanisms 9 and 10 (which may be replaced by a drive mechanism such as a piezo drive mechanism), respectively. Can be. The movement by the voice coil mechanisms 9 and 10 is performed by the signal transmitted from the controller 11. And the board | substrate 12 is provided on the support stand 8.

The laser beam focused by the objective lens 6 enters the galvano scanner 7. The galvano scanner 7 includes an X scanner 7a and a Y scanner 7b, and scans the laser beam at high speed in the two-dimensional direction. The X scanner 7a and the Y scanner 7b are each configured to include a reflecting mirror capable of swinging. When the X direction and the Y direction orthogonal to each other are defined on the substrate 12 supported by the support 8, the X scanner 7a and the Y scanner 7b are each an objective lens. The laser beam is scanned so that the incidence point of the laser beam focused at (6) moves on the surface of the substrate 12 in the X and Y directions. The galvano scanner 7 can scan a laser beam in a two-dimensional direction by combining the X scanner 7a and the Y scanner 7b.

The substrate 12 as the object to be processed is, for example, a substrate having an ITO film formed on a glass substrate, and the laser beam is incident on the ITO film of the substrate 12 at a processing energy of about 1 J / cm 2.

FIG. 2 is a schematic diagram showing an optical path of a laser beam that scans the substrate 12 through the mask 5, the objective lens 6, and the galvano scanner 7.

When the laser beam is incident on the incident position M on the substrate 12, the through hole of the mask 5 is formed in M. As shown in FIG. The optical path length from the mask 5 to the objective lens 6 is a, the optical path length from the objective lens 6 to the incident position on the substrate 12 is b, and the focal length of the objective lens 6 is f. In order for the through-holes of the mask to form on the substrate 12, the following relational expression must be satisfied.

By the operation of the galvano scanner 7, the incident position of the laser beam changes from the incident position M on the substrate 12 to N. If the incident angle to the incident position M and the incident angle to the incident position N are different, and the mask 5 and the objective lens 6 are fixed, the optical path length from the objective lens 6 to the incident position M is fixed. Since the optical path length from the objective lens 6 to the incident position N is different (these differences are Δb), the through hole of the mask 5 is not formed in N.

In the laser processing apparatus shown in FIG. 1, the controller 11 supplies a signal for moving the mask 5 and the objective lens 6 in synchronization with the operation of the galvano scanner 7, respectively. , Spend 10). This signal is, for example, a mask (so that the optical path length a from the mask 5 to the objective lens 6 and the optical path length b from the objective lens 6 to the incident position on the substrate 12 are kept constant. 5) and the objective lens 6 are moved. The voice coil mechanisms 9 and 10 receive a signal from the controller 11 and move the mask 5 and the objective lens 6 in directions parallel to the advancing direction of the laser beam, respectively.

As shown in FIG. 2, when the incident position changes from M to N, the distance that the mask 5 and the objective lens 6 are moved by the voice coil mechanisms 9 and 10 is Δb. The mask 5 and the objective lens 6 are displaced by the same distance Δb in the same direction. By doing so, Equation 1 is satisfied, and the through hole of the mask 5 is imaged at the incident position N. FIG.

Not only at two points between the incident position M and the incident position N, but also during the scanning of the laser beam, the optical path length a from the mask 5 to the objective lens 6, for example, and the objective If the optical path length b from the lens 6 to the incident position on the substrate 12 is kept constant, the through hole of the mask 5 is always imaged on the surface of the substrate 12. The mask 5 and the objective lens 6 are moved so that the optical path length a and the optical path length b are always constant in synchronization with the scanning of the laser beam by the galvano scanner 7. In this case, the imaging magnification (reduction ratio) of the through-holes of the mask 5 is always constant.

For example, the focal length f of the objective lens 6 is 833 mm, and the optical path length a from the mask 5 to the objective lens 6 is 5000 mm, and from the objective lens 6 to the substrate 12. In the case where the optical path length b to the incident position is kept at a constant value of 1000 mm, the imaging magnification (reduction ratio) of the through hole of the mask 5 is 1/5.

Fig. 3A is a schematic diagram of a substrate 12 in which a pulse laser beam is irradiated one shot to form an image of a through hole of a mask 5 on a surface thereof, and a hole is formed at an image formation position. It is a plan view. On the board | substrate 12, the rectangular beam spot in which the through-hole was formed is formed, and a hole is made in the ITO film | membrane in that position.

Fig. 3 (B) shows the groove in the irradiation position by irradiating four pulse laser beams by moving the incident position of the beam while forming a rectangular through hole of the mask 5 at a constant imaging magnification (reduction ratio). It is a top view of the board | substrate 12 in which the was formed. The galvano scanner 7 scans the pulsed laser beam in the long side direction of the beam spot formed into a rectangular shape. In addition, the beam is irradiated at a 50% redundancy, the holes made in each shot are continued to form grooves.

A groove having a predetermined width can be formed by forming a beam spot of a rectangular shape having a constant size and scanning the laser beam in a direction parallel to a pair of parallel sides (long sides in FIG. 3B). . When using a pulsed laser beam as in the present embodiment, a part of a pair of parallel sides of the beam spot (long side in FIG. 3 (B)) is parallel to the beam spot of the previous shot. The laser beam is scanned so as to overlap part of the pair of sides. Since the periphery of the groove opening is formed by the straight portion of the rectangular beam spot, the periphery of the groove opening has a straight shape without any unevenness.

From the standpoint of ease of control and the like, it is preferable to form a beam spot on the substrate 12 so that the direction of a pair of parallel sides of the beam spot is parallel to the X direction or the Y direction.

In addition, the through hole of the mask 5 to form on the board | substrate 12 may not be rectangular. When the beam spot is formed into a shape having a pair of parallel sides, and a laser beam is scanned in a direction parallel to the pair of parallel sides, a groove having a predetermined width without processing irregularities around the opening is processed. can do.

4A is a diagram illustrating an example of the through hole of the mask 5. The through hole of the mask 5 is formed in the shape which has a pair of parallel sides. The other pair of sides connecting the pair of sides is curved inward. When the cross section of the laser beam is shaped using a mask having such a through hole, a beam spot having a shape having a pair of parallel sides can be formed on the substrate 12.

FIG. 4B is a schematic diagram showing a hole formed in the substrate 12 when the through hole shown in FIG. 4A is formed on the substrate 12. By continuously forming holes having the same shape as the holes in a direction parallel to a pair of parallel sides, a groove having a predetermined width can be processed without having irregularities around the opening. Furthermore, since the cumulative energy density of the laser beam incident in the vicinity of the groove is larger than the cumulative energy density of the laser beam incident in the center of the groove, the side surface of the groove can be made closer to the vertical.

In addition, when laser-processing only the groove | channel extended in one direction as shown to FIG. 3 (B), you may use the 1-dimensional galvano scanner or polygon scanner which has one oscillation reflecting mirror. At this time, the scanning direction of a scanner and the direction of a pair of parallel sides of a beam spot should just match.

With reference to Figs. 5A to 5C, the conical optical system 4 will be described. As described above, the conical optical system 4 converts the beam profile of the incident laser beam so as to be weak at the center of the beam cross section and strong at the periphery.

FIG. 5A is a schematic graph showing the energy density per pulse in the cross section of the pulsed laser beam emitted from the laser light source 1. Pulsed laser beams generally have a higher pulse energy density at the center of the cross section and a lower pulse energy density toward the periphery. The conical optical system 4 inverts the center part and the peripheral part of the incident laser beam by two conical lenses 4a and 4b and emits them. Therefore, the beam profile of the laser beam emitted from the conical optical system 4 is weak at the center of the beam cross section and has a strong distribution at the periphery.

FIG. 5B is a schematic graph showing the energy density per pulse in the cross section of the pulsed laser beam emitted from the conical optical system 4 and shaped by the mask 5. The beam is weak at the center and has a strong pulse energy density distribution at the periphery.

FIG. 5C is a schematic cross-sectional view of the substrate 12 cut along the line C5-C5 in FIG. 3B. The laser beam having the beam profile shown in FIG. 5B is condensed by the objective lens 6 and is incident on the substrate 12 so that the inclination angle of the side surface of the ITO film of the substrate 12 is close to 90 °. Can be. Therefore, the groove shown in FIG. 3B is a groove having a side that stands upright in addition to being formed in a straight line in the circumference of the opening.

In synchronization with the operation of the galvano scanner 7, the pulse energy of the pulsed laser beam can be adjusted to perform higher quality processing. When the incident angle of the laser beam incident on the substrate 12 increases, the area of the beam spot at the incident position increases. Therefore, when the pulse energy of the laser beam scanned by the galvano scanner 7 is fixed at a constant value, as the incident angle becomes larger, the pulse energy density of the laser beam at the incident position becomes smaller, resulting in a change in workability. In order to maintain a constant workability, it is sometimes necessary to keep the pulse energy density of the laser beam at the incident position constant.

The variable attenuator 2 changes the pulse energy of the laser beam emitted from the laser light source 1 in synchronization with the operation of the galvano scanner 7. On the basis of the synchronization signal transmitted from the controller 11, when the laser beam enters the substrate 12 at a large angle of incidence, the attenuation rate of the pulse energy is reduced to increase the pulse energy of the beam emitted from the variable attenuator 2. Let's do it. By doing this, the pulse energy density at the incident position of the laser beam can be kept constant even during scanning of the beam.

In addition, when the angle of incidence of the laser beam to the substrate 12 is varied even when not kept constant, the attenuation rate of the pulse energy by the variable attenuator 2 is varied so as to reduce the variation in the pulse energy density at the incident position. , Can improve the quality of processing.

When the laser beam is incident on the substrate 12 and scanned, the laser beam is changed while synchronizing with the operation of the galvano scanner 7 while changing the imaging magnification (reduction ratio) of the through hole of the mask 5. The pulse energy density at the incident position may be kept constant.

Δ ₁ and Δ depending on the angle of incidence θ of the laser beam on the substrate 12 (the angle formed by the normal of the substrate 12 and the incident light) so as to satisfy the relationship between two equations (2) and (3). ₂ is set so that the optical path length from the mask 5 to the objective lens 6 is a + Δ ₂ , and the optical path length from the objective lens 6 to the incident position on the substrate 12 is b − Δ _1. What is necessary is just to move (5) and the objective lens 6 corresponding to incident angle (theta). Here, a and b are the optical path lengths from the mask 5 to the objective lens 6 when θ is 0, and the optical path lengths from the objective lens 6 to the incident position on the substrate 12, respectively. to be. In addition, f is the focal length of the objective lens 6. Even if the equations (2) and (3) are not strictly satisfied, the quality of laser processing can be improved by changing the imaging magnification so as to reduce the variation of the beam spot area when the incident angle varies. If the incident angle becomes large, the imaging magnification (reduction ratio) may be reduced.

FIG. 6 is a schematic diagram of a laser processing apparatus according to a modification of the first embodiment, provided with an optical path adjusting mechanism 20 for changing the optical path length b from the objective lens 6 to the incident position on the substrate 12. The voice coil mechanisms 9 and 10 are removed from the laser processing apparatus shown in FIG. 1, and the optical path adjusting mechanism 20 is joined. The other structure is the same as that of the laser processing apparatus shown in FIG. In the laser processing apparatus shown in FIG. 6, the optical path length a from the mask 5 to the objective lens 6 is constant. By the optical path adjusting mechanism 20, for example, in synchronization with the operation of the galvano scanner 7, the optical path length b from the objective lens 6 to the incidence position on the substrate 12 is always detected during scanning of the laser beam. You can keep it constant. By doing so, the through-hole of the mask 5 is always imaged on the board | substrate 12 at a constant image formation magnification (reduction rate), and the groove | channel shown in FIG. 3 (B) can be processed.

7 is a schematic diagram of the optical path adjusting mechanism 20. The optical path adjusting mechanism 20 includes four reflecting mirrors, for example, 21a to 21d. Each of the four reflection mirrors changes the advancing direction of the incident laser beam by 90 degrees, and the optical path adjusting mechanism 20 emits the laser beam in a direction parallel to the advancing direction of the incident laser beam. Two of the reflection mirrors 21a and 21b form the moving part 22. The moving part 22 can move in the direction of an arrow in a figure. The optical path length b from the objective lens 6 to the substrate 12 is adjusted by displacing the moving part 22. When the angle of incidence of the laser beam on the substrate 12 increases, the moving part 22 moves upward in FIG. 7 to shorten the optical path length of the laser beam in the optical path adjusting mechanism 20, thereby reducing the optical path length b. Keep constant The movement of the moving part 22 is performed by receiving the signal from the controller 11. The controller 11 keeps the optical path length b from the objective lens 6 shown in FIG. 6 to the substrate 12 constant by synchronizing the operation of the galvano scanner 7 and the movement of the moving part 22. .

In the laser processing apparatus shown in FIG. 6, the optical path adjusting mechanism 20 is joined to adjust the optical path length b. However, in order to adjust the optical path a, the optical path adjusting mechanism 20 is inserted between the mask 5 and the objective lens 6. You may. By using the two optical path adjusting mechanisms 20, the optical path length a and the optical path length b can be adjusted so as to satisfy the equation (1) even during scanning of the laser beam.

In addition, depending on the processing to be performed, only one of the mask 5 and the objective lens 6 may be moved in order to adjust the optical path length a or the optical path length b. For example, only the mask 5 may be moved to fix the objective lens 6 and satisfy the equation (1).

Although the substrate in which the ITO film | membrane was formed on the glass substrate was considered as a to-be-processed object, you may process a polyimide membrane part using the board | substrate with which the polyimide film | membrane was formed on the silicon substrate. These are used as solar cell substrates and liquid crystal substrates. In addition, a touch panel having an ITO film formed on the polyimide film, a semiconductor film, or the like can also be processed. Moreover, you may process a film object to be processed.

FIG. 8A is a schematic diagram of a conveyance mechanism 31 that conveys the film 30. The film 30 is conveyed by the conveyance mechanism 31. The vacuum chuck 32 fixes the predetermined processing position on the conveyed film 30, and defines the processing surface. The laser beam scanned by the galvano scanner 7 is incident on the film 30 fixed by the vacuum chuck 32, thereby processing the predetermined processing position. When the processing of the predetermined position is completed, the conveyance mechanism 31 conveys the film 30, and the other processing position is fixed by the vacuum chuck 32, and the processing is performed.

Conventionally, the film 30 fixed by the vacuum chuck 32 was moved to the XY stage, and the process was performed by irradiating a beam using a fixed optical system. In this embodiment, since the beam is scanned by the galvano scanner 7 and the beam is incident on the machining position, the machining speed can be increased.

FIG. 8B is a schematic diagram of a conveyance mechanism 31 provided with a rotary encoder 33. The rotary encoder 33 detects the speed of the film 30 conveyed by the conveyance mechanism 31. The detection result is sent to the controller 11, and the controller 11 calculates the conveyance amount of the film 30 from the conveyance speed of the film 30. The control signal created from the conveyance speed of the film 30, the conveyed quantity, and the data of the predetermined processing position defined on the film 30 is transmitted from the controller 11 to the galvano scanner 7. The galvano scanner 7 receives a control signal, scans a laser beam, and irradiates a beam to a predetermined processing position on the film 30 to perform processing.

Since the processing can be performed without the need for an XY stage and the film 30 is conveyed, the processing speed can be increased.

It is also possible to perform focusing by using the laser processing apparatus except the conical optical system 4, the mask 5, and the voice coil mechanism 9 from the laser processing apparatus shown in FIG. The laser beam is focused by the objective lens 6 so as to focus on the substrate 12. When the laser beam scans the substrate 12 by the operation of the galvano scanner 7 and the incidence position of the beam on the substrate 12 changes, the objective lens 6 becomes a voice coil mechanism ( 10), the optical path length b of the laser beam from the objective lens 6 to the substrate 12 is maintained in a direction parallel to the traveling direction of the beam passing through the objective lens. By this movement, the laser beam always focuses on the substrate 12. For this reason, high quality processing can be realized.

In this embodiment, a pulsed laser beam is used, but a continuous wave laser beam may be used depending on the processing to be performed. As the laser light source, although the tripled harmonics of the Nd: YAG laser were emitted using an Nd: YAG laser oscillator including a wavelength conversion unit, the fundamental to fifth harmonics of the solid state laser can be used. It is also possible to use a CO ₂ laser or the like.

In this embodiment, although the galvano scanner is used as the high speed scanning optical system, a high speed scanning optical system using a polygon mirror may be used. By moving the object to be processed on the XY stage, instead of changing the incident position of the laser beam, the beam is scanned using a high-speed scanning optical system and the incident position of the laser beam is changed, so that the processing speed can be improved.

By the way, in the above-mentioned focusing method, the laser beam always focuses on the substrate surface. Next, a method of performing high quality processing by adjusting the positional relationship between the focus of the laser beam and the substrate surface in accordance with the position of incidence of the laser beam on the substrate surface will be described.

12 (A), the laser processing apparatus according to the second embodiment excludes the conical optical system 4, the mask 5 and the voice coil mechanism 9 from the laser processing apparatus shown in FIG. Further, the variable attenuator 2 is excluded, and an aperture 5a is disposed between the expander 3 and the objective lens 6 having a circular through hole and adjusting the beam diameter. It is not necessary to form the through-holes of the aperture 5a on the surface of the substrate 12.

By using the voice coil mechanism 10, the objective lens 6 is moved in parallel with the advancing direction of the laser beam passing through the objective lens 6 to bring the focus of the laser beam closer to the surface of the substrate 12. By making it fall, the pulse energy density of the laser beam irradiated to the substrate surface is adjusted.

By the control signal transmitted from the controller 11, the galvano scanner 7 changes the laser beam in a desired travel direction at a desired timing. By operating the voice coil mechanism 10 in synchronism with the galvano scanner 7 according to the control signal transmitted from the controller 11, the laser is lasered at a desired pulse energy density to the substrate 12 in accordance with the incident position of the laser beam. Can be investigated.

With reference to FIG. 13, an example of the laser processing method using the laser processing apparatus of FIG. 12 (A) is demonstrated. The image side of FIG. 13 schematically shows the optical path of the pulsed laser beam scanned on the substrate 12 via the objective lens 6 and the galvano scanner 7.

The laser beam L1b enters the incidence position M1 perpendicular to the substrate surface. The laser beams L1a and L1c respectively enter the incident positions N1a and N1c at the incident angle α1. The incident position M1 is located at the midpoint of the line segment having the incident positions N1a and N1c at both ends.

The lower side of FIG. 13 shows the substrate surface viewed from the galvano scanner 7 side. Beam spots 91a, 91b, 91c represent beam spots (i.e., at incident positions N1a, M1, N1c) on the substrate surface of the laser beams L1a, L1b, L1c, respectively.

Irradiation of the pulsed laser beam is repeated while changing the traveling direction of the laser beam from the optical path of the laser beam L1a to the optical path of the laser beam L1c, and as shown in Figs. 10 (A) and 10 (B), The holes 101 are formed in the substrate surface so that the holes formed at the respective laser irradiation positions are continuous.

First, when the laser beam L1a forming the viewpoint of the groove 101 is irradiated, the position of the objective lens 6 is set so that the laser beam L1a is focused at the incident position N1a. do. Here, the point where the size of the beam spot becomes the minimum is called the focus of the laser beam.

When the laser beam L1c forming the end point of the groove 101 is irradiated, the position of the objective lens 6 is set so that the laser beam L1c focuses at the incident position N1c. do. Since the optical path lengths from the objective lens 6 to the incidence positions N1a and N1c are almost the same, the position of the objective lens 6 may be considered to be the same at the start and end of the groove processing. Incidentally, the laser beams L1a and L1c may have the same incident angle, and the beam spots 91a and 91c may have the same area.

Here, first, what problems arise when the groove is formed by scanning the laser beam while the objective lens 6 is fixed at this position.

When the objective lens 6 is fixed at the same position where the laser beam L1a is focused at the incident position N1a (or the laser beam L1c is focused at the incident position N1c), the galvano is fixed. A condensed surface 81a is a virtual surface on which the trajectory of the focal point of the laser beam whose traveling direction is changed by the scanner 7 is drawn. The point R on the light collecting surface 81a indicates the focal position of the laser beam L1b.

At the incidence positions on the grooves 101 other than the incidence positions N1a and N1c, the laser beam enters the substrate while focusing on the focal point. As the distance from the incident position to the focal point becomes longer, the beam diameter at the incident position becomes larger than the beam diameter at the focal point. The distance between the incident position and the focus is the maximum with respect to the laser beam L1b irradiated to the center of the groove.

The pulse energy density of the laser beam is usually higher in the center than in the vicinity of the outer circumference of the beam cross section. As the beam diameter increases, the pulse energy density at each position in the beam cross section decreases. Therefore, even if the beam diameter is large, the area that becomes the pulse energy density above the threshold at which the substrate can be processed is limited to the vicinity of the center of the beam cross section.

In the vicinity of the incidence positions N1a and N1c, which are the ends of the grooves 101, the laser beam whose beam diameter is small, but the pulse energy density becomes greater than or equal to the processing threshold to the outer circumference of the beam cross section is irradiated with a high pulse energy density, and thus the width This wide groove is formed. On the other hand, in the vicinity of the incident position M1, which is the center of the groove, the laser beam whose pulse energy density is greater than or equal to the processing threshold is irradiated with a low pulse energy density only in a region where the beam diameter is large but the center of the beam cross section is narrow. A narrow groove is formed. In this way, the width of the grooves varies depending on the place.

The distance from the incident position M1 of the laser beam L1b to the point R on the condensing surface 81a becomes longer as the incident angle α1 becomes larger. Therefore, as the incident angle α1 becomes larger, the difference between the beam diameter of the laser irradiated to the incident positions N1a and N1c and the beam diameter of the laser irradiated to the incident position M1 becomes larger. That is, the difference in width between the end of the groove and the center becomes remarkable. The incidence angle α1 is the incidence angle of the laser beam forming the end of the groove, and therefore becomes large, for example, when a long groove is to be formed in a large substrate.

Next, a method of forming a groove by scanning a laser beam while adjusting the focal position by moving the position of the objective lens 6 will be described. By adjusting the focal position of the laser beam, the beam diameter of the laser beam irradiated onto the substrate is adjusted, so that the pulse energy density on the surface of the substrate is adjusted.

Consider where the focus of the laser beam L1b incident on the incident position M1 may be focused. By setting the focus to a position closer to the incidence position M1 than the point R on the condensing surface 81a, the beam diameter can be reduced to correct the pulse energy density at the incidence position M1 to be increased. However, when the focus is brought closer to the incident position M1, the pulse energy density at the incident position M1 becomes higher than the pulse energy density at the incident positions N1a and N1c.

Since the laser beam L1b is incident perpendicularly to the substrate surface, the beam spot at the time of focusing at the incident position M1 becomes circular. On the other hand, since the laser beams L1a and L1c are obliquely incident on the substrate surface at an angle of incidence α1, the beam spots 91a and 91c have an elliptical shape. That is, the pulse energy density in the beam spot 91b when the laser beam L1b is focused at the incident position M1 becomes higher than the pulse energy density in the beam spots 91a and 91c.

Thus, by adjusting the focus of the laser beam L1b to a position slightly deeper than the incident position M1 (far from the incident position M1 toward the inside of the substrate), the area of the beam spot 91b is the incident position N1a. It is equal to the area of the beam spot (91a, 91c). In this manner, the laser beam can be irradiated to the incident position N1a or the incident position N1c and the incident position M1 at the same pulse energy density to perform processing.

Even at other incidence positions on the grooves 101, the area of the beam spot may be kept constant, the pulse energy density may be adjusted, and the processing may be performed. The locus of focus when the groove 101 is scanned on the condition that the area of the beam spot is not changed is the light collecting surface 81b. The focal position of the laser beam L1b is the point Q on the condensing surface 81b.

How to adjust the position of the objective lens 6 when moving the focus along the light collecting surface 81b. First, when the laser beam L1a is irradiated, the objective lens 6 is set at the same position as the focus at the incident position N1a. This position is called a reference position.

When scanning the laser beam from the incidence position N1a toward the incidence position M1, the objective lens 6 is gradually moved from the reference position toward the laser light source, thereby bringing the focus closer to the substrate surface than the condensing surface 81a. By moving along the condensing surface 81b, the area of the beam spot becomes large and the decrease in pulse energy density is suppressed. The moving distance from the reference position of the objective lens is zero with respect to the laser beam L1a incident on the incident position N1a, and increases as the laser faces the incident position M1, and the incident position ( The laser beam L1b incident on M1) is maximized.

Subsequently, when scanning the laser beam from the incidence position M1 toward the incidence position N1c, the objective lens 6 may be gradually brought closer to the reference position. The movement distance from the reference position of the objective lens decreases as the laser is directed toward the incident position N1c, and is set to zero for the laser beam L1c incident on the incident position N1c.

In this way, the laser beam is scanned while adjusting the position of the objective lens 6 so that the focal point of the laser beam irradiated to each incident position moves along the condensing surface 81b, thereby suppressing the change of the width depending on the place. The groove 101 can be formed.

The moving method of the objective lens is summarized. If scanning continues without moving the position of the objective lens, if the pulse energy density on the substrate surface decreases, the objective lens is moved so that the focal point of the laser beam is close to the incident position, so as to suppress the decrease in the pulse energy density. do. If scanning continues without moving the position of the objective lens, if the pulse energy density on the substrate surface rises, on the contrary, the objective lens is moved so that the focal position of the laser beam is far from the incident position, thereby increasing the pulse energy density. This can be suppressed.

As an example of the processing, a method of focusing on the substrate surface at the incidence positions of both ends of the grooves has been described, but may be focused on other incidence positions. If the beam spot of each incident position is kept to a substantially constant area, the pulse energy density can be adjusted and processed, so that a constant workability can be maintained at any incident position.

Even if the pulse energy density of the laser beam to be irradiated is not kept strictly constant at each incidence position, when the incidence position changes, the pulse energy density at the incidence position can be suppressed from fluctuating, so that processing can be satisfactorily performed. I can do it.

Although groove processing (scribing processing) has been described as an example, punching processing or the like may be performed. Although the example which scans a galvano scanner in the 1-dimensional direction was demonstrated, you may perform the process like scanning over the whole board | substrate by scanning in a 2-dimensional direction. Although processing using a pulsed laser beam has been described as an example, the laser beam may be a continuous fire. When processing with a continuous wave laser beam, it is made to suppress that the power density in a to-be-processed surface changes for every incident position.

The pulse energy density of the laser beam irradiated onto the substrate may be adjusted using a variable attenuator instead of moving the objective lens 6.

The variable attenuator 2 is added to the laser processing apparatus shown in FIG. 12 (A) to the laser processing apparatus according to the modification of the second embodiment shown in FIG. 12 (B). The variable attenuator 2 attenuates the power of the pulsed laser beam irradiated to the substrate 12 at a desired attenuation rate in synchronization with the operation of the galvano scanner 7 based on the control signal transmitted from the controller 11. You can.

With reference to FIG. 14, an example of the laser processing method using a variable attenuator is demonstrated. FIG. 14 schematically shows an optical path of a pulsed laser beam that scans the substrate 12 via the objective lens 6 and the galvano scanner 7 in the laser processing apparatus shown in FIG. 12B.

The laser beam L2b enters the incidence position M2 perpendicular to the substrate surface. The laser beams L2a and L2c respectively enter the incident positions N2a and N2c at the incident angle α2. The incidence position M2 is located at the midpoint of the line segment having the incidence positions L2a and L2c at both ends.

The objective lens 6 is fixed to a position at which the laser beam L2b is focused at the incident position M2. The condensing surface 82 is a virtual surface on which the trajectory of the focal point of the laser beam whose traveling direction is changed by the galvano scanner 7 is drawn.

As described with reference to FIG. 13, the irradiation of the pulsed laser beam is repeated while changing the traveling direction of the laser beam from the optical path of the laser beam L2a to the optical path of the laser beam L2c to form a groove on the substrate surface. .

As the incidence position of the laser beam is separated from the incidence position M2, the distance from the time the laser beam is focused to enter the substrate becomes longer. Since the laser beam after passing through the focus becomes a diverging beam of light, the longer the distance from the focus to the incident position, the larger the beam spot on the substrate surface.

Further, as the incidence position is separated from the incidence position M2, the incidence angle of the laser beam onto the substrate becomes larger. Even when a laser beam having the same beam diameter is irradiated, the larger the incident angle, the larger the beam spot on the surface of the substrate.

As described with reference to FIG. 13, the pulse energy density in the large beam spot is reduced over the entire beam cross section, and it is limited to the vicinity of the center of the beam cross section to be equal to or larger than a threshold capable of processing the substrate. For this reason, the width | variety of the groove | channel formed by irradiation of a large beam spot becomes narrow.

When a groove is formed by irradiating a laser with a constant pulse energy at any incidence position, the width of the groove is formed near the center of the groove, and the width of the groove is narrow.

Therefore, the power is adjusted by the variable attenuator 2 in accordance with the incident position so that the pulse energy density at the substrate surface becomes constant at any incident position. The amount of attenuation of power is minimized when the end of the groove is processed, and increases as it is directed toward the center of the groove, and maximum when the incident position M2, which is the center of the groove, is irradiated. In this way, it is possible to suppress the fluctuation of the width from place to place and to form a groove.

Then, in order to uniformize the pulse energy density of the laser beam irradiated onto the substrate, the objective position is moved by moving the objective lens 6 with the voice coil mechanism 10, and the pulsed laser beam with the variable attenuator 2 is used. It is also possible to use a combination of attenuating power.

The laser beam may be a continuous fire. When processing with a continuous wave laser beam, the power of a continuous wave laser beam is adjusted with a variable attenuator so that the power density in a to-be-processed surface may change for every incident position.

By the way, in the processing of the glass base material in which the ITO film | membrane was formed in the surface, for example, the board | substrate size tends to enlarge. When the substrate becomes large and the area to be processed increases, the amount of movement of the objective lens 6 increases in the processing performed by moving the objective lens 6 in accordance with the incident position of the laser beam as described with reference to FIG. 13. There is a case. From the viewpoint of ease of control, it is preferable that the movement amount of the objective lens 6 can be made small.

Next, referring to Fig. 15A, the laser processing apparatus according to the third embodiment can increase the moving distance of the focus position of the laser beam while suppressing the movement of the objective lens 6 at a short distance. Explain about.

In the laser processing apparatus shown in FIG. 15A, a secondary condenser lens 71 is added between the objective lens 6 and the galvano scanner 7 of the laser processing apparatus shown in FIG. 12A. . In the description of FIG. 15A, the objective lens 6 is referred to as a primary condensing lens 6.

The laser beam emitted from the aperture 5a enters the primary condensing lens 6. The primary condensing lens 6 condenses a laser beam on the virtual primary condensing surface 83. The laser beam passing through the primary condensing surface 83 becomes a diverging beam and enters the secondary condensing lens 71. The laser beam focused by the secondary condenser lens 71 changes in the traveling direction to the galvano scanner 7 and enters the substrate 12.

Next, the movement amount of the primary condensing lens 6 will be described. When the primary condensing surface 83 is brought close to the secondary condensing lens 71, the focus position of the laser beam focused on the secondary condensing lens 71 moves in the direction in which the laser beam travels. The moving distance of the primary light collecting surface 83 is d1, and the moving distance of the focal point of the laser beam is d2. Also, the numerical aperture of the secondary condenser lens 71 for the laser beam incident on the secondary condenser lens 71 is NA1, and the secondary condenser lens 71 for the condensed beam that has passed through the secondary condenser lens 71. Let numerical aperture be NA2. Magnification P,

P = NA1 / NA2

If you define as

d2 = d1 × P ²

This holds true.

As can be seen from the above equation, when the magnification P is increased, the moving distance d2 of the focus can be increased even if the moving distance d1 of the primary condensing surface 83 is shortened. For example, when the magnification P is 2, the focus of the laser beam can be shifted in the advancing direction of the 8 mm laser beam by bringing the primary condensing surface 83 close to the 2 mm secondary condensing lens.

The primary condensing surface 83 is moved by moving the primary condensing lens 6 in the optical axis direction. When the laser beam incident on the primary condensing lens 6 is a parallel light beam, the movement distance of the primary condensing lens 6 and the movement distance of the primary condensing surface 83 are the same. If the distance for moving the primary condenser lens 6 is about 2 mm or less, a linear mechanism using a piezo drive mechanism can be used. By using the linear motion mechanism using the piezoelectric drive mechanism instead of the voice coil mechanism 10, the primary condensing lens 6 can be moved at high speed and with high precision.

16 shows an example of the configuration of the secondary condensing lens 71. FIG. The secondary condensing lens 71 is composed of a plurality of lenses. So (So) and shop (Si) are in a similar relationship (the point of integrating and dividing one line segment at the same ratio). This object point So corresponds to the position of the beam spot on the primary condensing surface 83 shown in Fig. 15A. This imaging optical system is regarded as an infinite optical system. The secondary condensing lens 71 is divided into a front lens group 71a and a rear lens group 71b. The light beam emitted from the object point So becomes a parallel light beam in the front lens group 71a. This parallel light beam focuses on the shop Si by the rear lens group 71b. And although the secondary condensing lens 71 may not be physically divided, it is considered here that it is divided virtually.

Let Ff be the front focal length of the front lens group 71a and Fr be the rear focal length of the rear lens group 71b. At this time, the magnification P defined by the above-described formula is

P = Fr / Ff

It is expressed as

In the laser processing apparatus shown in Fig. 15A, the primary condensing lens 6 is formed of a convex lens, but as shown in Fig. 15B, the concave lens 6a may be formed. At this time, the primary condensing surface 83a becomes a virtual image and appears on the laser light source side rather than the concave lens 6a.

By increasing the magnification P in this manner, the focal position of the laser beam irradiated onto the substrate can be greatly changed while the movement distance of the primary condensing lens 6 is kept short. In order to achieve a beneficial effect, it is preferable to make magnification P 2 or more, and it is more preferable to set it as 4 or more.

By the way, since the beam spots 91a and 91c shown in FIG. 13 are beam spots of the laser beam which obliquely enter the substrate, they are elliptical. On the other hand, since the beam spot 91b is the beam spot of the laser which injects perpendicularly | vertically to a board | substrate, it became circular. In this way, the incident angle is different depending on the incident position of the laser beam, the phenomenon that the beam spot shape on the substrate is different.

The opening of the hole to be processed becomes oval if the beam spot is elliptical, and circular if it is circular. However, there may be a case where the openings of the holes have the same shape (for example, circular shape) at any incident position.

Next, with reference to FIG. 17, the laser processing apparatus by 4th Example which can correct the shape of a beam spot according to an incident position is demonstrated.

In the laser processing apparatus shown in FIG. 17, the laser processing apparatus shown in FIG. 12A includes an aperture inclination mechanism 60a for rotating the aperture 5a around an axis perpendicular to the optical axis of the laser beam, and upper. An aperture rotation mechanism 61a is added to rotate the chutes 5a around an axis parallel to the optical axis of the laser beam.

The aperture rotating mechanism 61a is a mechanism similar to that in which the mask rotating mechanism of the laser processing apparatus described later with reference to FIG. 22A rotates the mask. Rotate around an axis parallel to the optical axis of.

The aperture inclination mechanism 60a and the aperture rotation mechanism 61a are respectively synchronized with the operation of the galvano scanner 7 on the basis of the control signal transmitted from the controller 11, The inclination angle around the axis perpendicular to the optical axis of the laser beam and the rotation angle around the axis parallel to the optical axis of the laser beam are changed.

The beam cross-sectional shape perpendicular to the optical axis when the laser beam is obliquely incident on the substrate surface is compared with the beam cross-sectional shape on the substrate surface. The beam cross-sectional shape on the substrate surface is a shape in which the beam cross-sectional shape perpendicular to the optical axis is stretched in the cross direction of the substrate surface and the incident surface. For example, when a laser beam of circular cross section is obliquely incident on the substrate surface, the beam cross section on the substrate surface becomes long oval in the intersection direction of the substrate surface and the incident surface. As the incident angle increases, the beam spot on the surface of the substrate becomes longer in the cross direction.

Therefore, the cross section perpendicular to the optical axis is incident on the substrate surface at an angle so that the laser beam shaped into an ellipse having an appropriate long axis and short axis ratio is perpendicular to the incidence plane so that the substrate is inclined. The beam spot of the surface may be circular.

18A is a view of the aperture 5a rotated around an axis perpendicular to the optical axis of the laser beam by the aperture inclination mechanism 60a along the rotation axis direction of the aperture inclination mechanism 60a. Schematically. The laser beam 1b incident from the left side of the figure is shaped by the aperture 5a and exits to the right side of the figure.

As shown in Fig. 18B, the circular through hole 62a of the aperture 5a rotated by the aperture inclination mechanism 60a looks elliptical when viewed from the line of sight along the optical axis of the laser beam. That is, the cross section of the laser beam is shaped like an oval.

And when the surface where two other diameters of the circular through-hole of the aperture 5a extend is orthogonal to the optical axis of a laser beam, the cross section of a laser beam is circular shaped. The inclined upper aperture 5a increases the angle between the rotational center axis of the circular through hole and the optical axis of the laser beam, so that the elliptical short axis of the beam cross section after shaping becomes short. Thus, the aperture inclination mechanism 60a can change the aspect ratio of the beam cross section after shaping.

As shown in FIG. 18 (C), the aperture 5a is further rotated around an axis parallel to the optical axis of the laser beam by using the aperture rotating mechanism 61a.

The beam cross-sectional shape at a position where the beam spot of the laser beam is minimized (called the focus of the laser beam) is elliptical. The long axis direction of the beam cross section at the focal point corresponds to the short axis direction of the beam cross section at the position of the through hole of the aperture 5a.

Therefore, the aperture 5a is rotated by the aperture rotation mechanism 61a so that the long axis direction of the ellipse of the beam cross section at the position of the through hole coincides with this intersection direction. In this way, the shape of the beam spot on the substrate can be kept circular at any incident position.

And although the processing by the condensing method which does not need to form the through-hole of an aperture on the board | substrate surface was demonstrated, even if the process by the mask projection method which forms the image of a through-hole on the board | substrate surface is performed, The shape of the beam spot can be corrected. In the mask projection method, the major axis direction on the through hole formed on the substrate surface corresponds to the major axis direction of the beam cross section at the position of the through hole of the mask.

The same applies to the inclination of the mask having a circular through hole around an axis perpendicular to the optical axis of the laser beam. However, when the mask is rotated about an axis parallel to the optical axis of the laser beam, the elliptical short axis direction of the beam cross section when the through-hole is emitted is rotated so as to coincide with the intersection direction between the incident surface and the substrate surface.

Although the case where the shape of the through-hole is the cause has been described, the beam spot shape of the laser beam shaped by the through-hole of another shape may be corrected.

Next, with reference to FIG. 19, the laser processing apparatus by 5th Example which performs the laser processing method using a proximity mask is demonstrated. In the laser processing apparatus shown in FIG. 19, the proximity mask 63 is added to the laser processing apparatus shown in FIG. 12 (A).

The proximity mask 63 is supported by the proximity mask support mechanism 64 and is disposed directly above the substrate 12 in parallel with the surface of the substrate 12. In the proximity mask 63, a through hole having the same shape as the shape to be processed is formed in the substrate surface. The distance (proximal gap) dg between the proximity mask 63 and the surface of the substrate 12 can be adjusted by the proximity mask support mechanism 64.

The expander 3 enlarges the beam diameter of the laser beam which emitted the laser light source 1, and emits the laser beam of parallel light. The laser beam exiting the expander 3 has a spread angle β. By the expander 3, when the beam diameter of the laser beam is enlarged by 10 times, for example, the spread angle is reduced to 1/10. By the expander 3, the spread angle of the laser beam can be adjusted.

The laser beam is irradiated while scanning the proximity mask 63 on the galvano scanner 7. In the through-hole of the proximity mask 63, a laser beam passes and enters the board | substrate 12, and the board | substrate 12 is processed. In portions other than the through hole, the laser beam does not pass, and the substrate 12 is not processed. In this manner, the surface of the substrate can be processed by transferring the shape of the through hole of the proximity mask 63.

At this time, even if the incidence position of the laser beam is changed, the laser irradiation is performed while moving the position of the objective lens 6 in accordance with the incidence position of the laser beam on the substrate so that the variation in pulse energy density on the substrate surface is suppressed. Can be. The laser light source 1 may emit a continuous wave laser beam. In that case, the variation of the power density on the substrate surface is suppressed.

By the way, in order to perform high precision processing, the shape of the through hole which the proximity mask 63 has must be correctly transferred to the board | substrate. The accuracy of the transfer depends on the proximity gap dg and the spread angle of the laser beam irradiated to the proximity mask 63. The spread angle of the laser beam irradiated to the proximity mask may be considered to be the same as the spread angle β of the laser beam when passing through the expander.

FIG. 20 shows a simulation result of how the transfer accuracy changes depending on the proximity gap and the spread angle of the laser beam, for the proximity mask having the T-shaped through hole. The image 97 of the T-shaped through hole in the case where the spreading angle of the proximity gap and the laser beam is varied is shown in a line. In each drawing, the spreading angle of the laser beam is smaller as it is arranged on the right side, and the proximity gap is smaller as it is arranged on the lower side.

The clearer the circumference of the image 97, the higher the accuracy of the transfer. As can be seen from the figure, at the same spread angle, the accuracy of transfer deteriorates as the proximity gap increases. Also, in the same proximity gap, the greater the spread angle, the lower the accuracy of transfer. The smaller the proximity gap and the spread angle, the higher the transfer accuracy.

Fig. 21 schematically shows a graph of the relationship in which the spreading angle of the proximity gap and the laser beam must be satisfied when certain transfer accuracy is to be secured. When certain transfer accuracy is to be secured, when the proximity gap is large, the spread angle must be made smaller, and when the spread angle is large, the proximity gap must be made small.

For various transfer precisions, as shown in Fig. 21, when the relationship between the proximity gap and the laser beam spreading angle must be obtained in advance, the proximity gap and the spreading angle can be obtained when processing is performed with the desired transfer accuracy. It is easy to select.

The laser processing method using the proximity mask has the advantage that the processing can be performed with high transfer accuracy by setting the proximity gap and the spread angle small. In addition, high positioning accuracy can be obtained by arranging the through-holes of the proximity mask directly above the processing position of the substrate. In addition to the position to be processed, since the proximity mask covers the substrate surface, there is an advantage that the by-products generated by the substrate being scraped during processing are difficult to adhere to the substrate surface.

When the laser beam passing through the through-hole of the proximity mask is irradiated to the substrate, the substrate is moved by changing the advancing position of the laser beam with the galvano scanner. The speed of processing can be increased compared to the case where the incident position is moved by moving the mounted XY stage.

Next, with reference to FIG. 22A, the laser processing apparatus which concerns on 6th Example which has a laser light source which oscillates a laser beam of a continuous wave is demonstrated. As the laser light source 1 for oscillating a laser beam of continuous waves, for example, a semiconductor laser for oscillating a laser beam of a wavelength in the infrared region can be used.

The laser beam lb0 emitted from the laser light source 1 enters into the separation optical system 65. The separation optical system 65 separates the laser beam lb0 into a laser beam lb1 traveling along a certain optical axis at a certain time zone and a laser beam lb2 traveling along a different optical axis at another time zone. do.

The separation optical system 65 includes, for example, a half-wave plate 65a, an electro-optical element 65b having a Pockels effect, and a polarizing plate 65c. The half-wave plate 65a sets the laser beam lb0 emitted from the laser light source 1 to be linearly polarized light such that it becomes a P wave with respect to the polarizing plate 65c. This P wave is incident on the electro-optical element 65b.

The electro-optical element 65b rotates the polarization axis of the laser beam based on the instrument signal sig transmitted from the controller 11. When the electro-optical element 65b is in a voltage-free state, incident P waves are emitted as they are. When the electro-optical element 65b is in a voltage inductance state, the electro-optical element 65b rotates the polarization plane of the P wave by 90 degrees. As a result, the laser beam emitted from the electro-optical element 65b becomes S-wave with respect to the polarizing plate 65c.

The polarizing plate 65c transmits the P wave as it is and reflects the S wave. The S-beam laser beam lb1 reflected by the polarizing plate 65c enters the beam damper 66 which is the end of the laser beam lb1. The laser beam lb2, which is P-wave transmitted through the polarizing plate 65c, enters the expander 3.

The expander 3 expands the beam diameter, and the laser beam lb2 made of parallel light enters the mask 5 having a rectangular through hole. Here, processing by the mask projection method will be described as an example. That is, processing is performed by forming an image of the through hole of the mask 5 on the surface of the substrate 12.

The mask rotating mechanism 61 is used to rotate the mask 5 around an axis parallel to the optical axis of the laser beam. The mask rotating mechanism 61 includes, for example, a goniometer, and rotates the mask by a desired angle at a desired timing based on a control signal transmitted by the controller 11. The mask rotating mechanism 61 will be described later in detail. The voice coil mechanism 9 moves the position of the mask 5 in parallel with the advancing direction of the laser beam.

The laser beam lb2 emitted from the mask 5 is focused by the objective lens 6. The voice coil mechanism 10 moves the position of the objective lens 6 in parallel with the advancing direction of the laser beam. The laser beam which has exited the objective lens 6 enters the surface of the substrate 12 after passing through the galvano scanner 7.

With reference to FIG. 22B, the board | substrate 12 which is a to-be-processed object is demonstrated. The transfer layer 111 exists on the surface of the underlayer 110. The transfer layer 111 has a property of adhering to the surface of the base layer 110 when heat is applied.

For example, a part 111a of the transfer layer 111 is heated by laser irradiation and adhere | attached on the underlayer 110. FIG. When the unheated portion 110b of the transfer layer 111 is removed, only the heated portion 111a remains on the surface of the underlayer 110. This is similar to, for example, when performing thermal transfer printing, ink in the heated portion of the ink ribbon is transferred to paper.

Returning to Fig. 22A, the explanation will continue. The XY stage 8a is used as a support for the substrate 12. The XY stage 8a can move the board | substrate 12 in the two-dimensional surface parallel to the surface of the board | substrate 12. FIG. The XY stage 8a is controlled by the controller 11, and the board | substrate 12 is moved to a desired position at a desired timing.

In the example of the laser processing method described here, the laser beam from which the X scanner 7a and the Y scanner 7b of the galvano scanner 7 exits the galvano scanner 7 is perpendicular to the substrate 12. It is fixed at the same position as the incident light. By moving the substrate 12 on the XY stage 8a, the position of incidence of the laser beam on the substrate 12 is moved.

Using the voice coil mechanisms 9 and 10, the optical path length from the mask 5 to the objective lens 6 and the optical path length from the objective lens 6 to the incident position of the laser beam of the substrate 12 are the masks. The image of the through hole in (5) is set to image at a desired image formation magnification (reduction rate) on the surface of the substrate 12.

Referring to Fig. 23, the control method of the separation optical system will be described. Fig. 23 shows an example of the timing chart of the instrument signal sig and the laser beams lb0, lb1, lb2. At time t0, emission of the laser beam lb0 is started.

From time t0 to time t1, the instrument signal sig is not sent out from the controller. During this time, no voltage is applied to the electro-optical element, and the laser beam lb2 is always emitted from the separation optical system. The laser beam lb1 is not emitted. The laser beam lb2 during this time becomes a continuous wave.

From time t1 to time t2, a voltage is applied to the electro-optical element of the separation optical system in synchronization with the instrument signal sig periodically sent out by the controller.

While the instrument signal sig is being sent, the electro-optical element is in a voltage application state, and the laser beam lb0 is separated into the laser beam lb1. On the other hand, while the instrument signal sig is not being sent, the electro-optical element is in a voltage-free state, and the laser beam lb0 is separated into the laser beam lb2. The laser beam lb2 from the time t1 to the time t2 becomes a laser beam in which oscillation and stop are repeated periodically.

In this intermittently emitted laser beam lb2, the pulse width w1 and the period w2 can be set to an arbitrary length by adjusting the instrument signal sig. For example, the pulse width w1 is set to 10 s to 10 s, and the period w2 is set to several 100 s.

In this manner, when no instrument signal is input to the separation optical system, a laser beam lb2 that is continuously emitted is obtained. When the instrument signal is intermittently input to the separation optical system, a pulse laser beam lb2 that is intermittently emitted is obtained. Obtained.

By the way, since the laser beam lb2 emitted continuously can be irradiated to a board | substrate continuously, it is suitable for the process of forming a line (process which leaves a transfer layer in a line shape on a base layer), for example. On the other hand, the laser beam lb2 emitted intermittently can be irradiated onto the substrate intermittently, and thus is suitable for, for example, a process of forming a dot (a process of leaving the transfer layer in a dot shape on the underlying layer).

With reference to FIG. 24 (A), the method of line processing is demonstrated. Laser irradiation to the substrate 12 is started, and processing is started. At the start of processing, first, the area over the entire width of one end of the line 103 is irradiated by the rectangular beam spot 93. Thereafter, while irradiating the laser continuously, the XY stage is moved in one direction so that the beam spot faces the other end of the line 103. The moving direction of the XY stage is parallel to any side of the rectangular beam spot 93. The direction of movement of the beam spot on the substrate is indicated by an arrow.

When the beam spot reaches the other end of the line 103, the laser irradiation to the substrate is stopped to finish the processing. In this way, the line-shaped region on the substrate surface is heated by laser irradiation, whereby the line 103 in which the transfer layer remains in a line shape on the surface of the underlying layer is formed.

The outline of the formed line 103 becomes a rectangle parallel to a side of the longitudinal side beam spot 93 and parallel to a side of the width direction side perpendicular to a side of the beam spot 93. The width of the line 103 is equal to the length of the side orthogonal to any side of the beam spot 93.

With reference to FIG. 24 (B), the method of dot processing is demonstrated. In dot processing, the XY stage is moved in one direction while irradiating a laser beam to the substrate 12 intermittently. The moving direction of the XY stage is parallel to a certain side (called side p) of the rectangular beam spot 94a.

First, at the start of the first pulse laser irradiation, the area on the entire width of one end of the dot 104a is irradiated by the rectangular beam spot 94a. Since the XY stage moves, the beam spot moves on the substrate until the laser irradiation of the first pulse ends. The direction of movement of the beam spot is indicated by an arrow.

Thus, the dot-shaped area | region of the board | substrate surface is heated by laser irradiation, and the dot 104a in which the transfer layer remained in the dot form on the surface of a base layer is formed.

Thereafter, in the same manner, dots 104b, 104c, 104d and 104e are formed by laser irradiation at the second, third, fourth and fifth pulses, respectively. The area of the substrate surface irradiated by the beam spots 94b, 94c, 94d, and 94e at the start of irradiation at the second, third, fourth, and fifth pulses is an area of the substrate surface irradiated by the beam spot 94a. And the area moved parallel to the moving direction of the XY stage. Each dot is arranged on a straight line parallel to the moving direction of the XY stage.

The outline of each dot is a rectangle having a side parallel to the side p of the beam spot 94a and a side parallel to the side (referred to the side q) orthogonal to the side p of the beam spot 94a. do.

The length of the side orthogonal to the moving direction of the XY stage of each dot is the same as the length of the side q, For example, when the length q is 20 micrometers, it will be 20 micrometers.

The length of the side parallel to the movement direction of the XY stage of each dot depends on the length of the side p of the beam spot, the speed of the movement of the XY stage, and the irradiation time (pulse width) of the pulse.

For example, it is assumed that the length of the side p of the beam spot is 12 m, the speed of the movement of the XY stage is 800 mm / s, and the pulse width is 10 Hz. Since the distance at which the XY stage moves (i.e., the distance that the substrate moves) during the pulse width of 10 s is 8 m, the length of the side parallel to the moving direction of the XY stage of the dot is the length 12 of the side p of the beam spot. It becomes 20 micrometers which added 8 micrometers to the micrometer, and the moving distance.

The pitch d between adjacent dots coincides with the distance the XY stage moves during one period of the pulse. For example, when the period of the pulse is 375 Hz and the moving speed of the XY stage is 800 mm / s, the pitch d is 300 m.

In summary, the size of the beam spot is set to 12 µm in the length of the side (p) and 20 µm in the length of the side (q), and the laser beam is oscillated at a pulse width of 10 mW and a period of 375 mW, and the XY stage is 800. In the case of moving to mm / s, 20 micrometer square dots can be formed in 300 micrometer pitch.

By the way, it may be desired to process a plurality of lines each having a different direction on the substrate. However, when lines in other directions are formed while the beam spot on the substrate is made constant, problems such as the width of the line change depending on the direction of the line arise.

An example of such a situation will be described with reference to FIG. 29. By the method described with reference to Fig. 24A, first, a line 109a is formed. Next, a line 109b having a direction different from the line 109a is formed without changing the direction of the beam spot. At the start of laser irradiation, the beam spot 99 is irradiated to one end of the line 109b. The line 109b is formed by moving the beam spot to the other end of the line 109b while moving the XY stage in the longitudinal direction of the line 109b.

As shown in the figure, the width of the line 109a is equal to the length of the long side of the beam spot 99, but the width of the line 109b is not necessarily equal to the length of this long side. In addition, the edge of the end of the line 109b cannot be formed to be orthogonal to the longitudinal direction of the line. By using the mask rotating mechanism 61 shown in Fig. 22A, such a problem can be avoided.

25 is a schematic diagram showing a mask rotating mechanism 61 supporting the mask 5 having a rectangular through hole 62. The two diagonally extending surfaces of the rectangular through hole 62 are perpendicular to the optical axis of the laser beam. The mask rotating mechanism 61 rotates the mask 5 around an axis parallel to the optical axis of the laser beam, with the center of rotation of the diagonal of the rectangle of the through hole 62 as the center of rotation.

In response to the rotation of the mask 5, the image of the through hole 62 rotates in the surface of the substrate 12. The side of the rectangle of the through-hole 62 on a board | substrate can be made parallel to arbitrary directions in a board | substrate surface.

As described below, in order to change the direction of the line or the like to be processed, the mask 5 can be rotated by the mask rotating mechanism 61 before changing the moving direction of the incident position of the laser beam on the substrate.

With reference to FIG. 26, the processing method of the line using a mask rotating mechanism is demonstrated. The line 103a is formed by the method described with reference to Fig. 24A. The length of the long side of the beam spot 93a is equal to the width of the line 103a, and the direction of the short side of the beam spot 93a is parallel to the longitudinal direction of the line 103a.

Before starting processing of the line 103b having a direction different from the line 103a, the mask is rotated by the mask rotating mechanism so that the short side of the beam spot 93b is parallel to the longitudinal direction of the line 103b. do. Then, the substrate is moved by the XY stage so that the beam spot is irradiated over the entire width of one end of the line 103b.

The irradiation of the laser beam is started, and the line 103b is formed while moving the XY stage in the longitudinal direction of the line 103b by the same process as described with reference to Fig. 24A. The width of the line 103b is equal to the length of the long side of the beam spot 93b. Moreover, the side of the width direction of the line 103b, and the side of the longitudinal direction are orthogonal.

In this manner, a plurality of lines each having a different direction can be formed to have the same width. And in order to form the some dot which has a different direction, without changing size and shape, you may use a mask rotation mechanism.

Although the example in which the separation optical system is controlled by a periodic instrument signal to pulse the laser beam has been described, the instrument signal may not be periodic. For example, when it is desired to form a plurality of dots with different pitches, a non-periodic instrument signal can be used. In addition, the pulse width of a laser beam does not need to be constant. What is necessary is just to set suitably according to the size etc. of the dot to form.

By changing the shape or size of the beam spot on the substrate, the width of the line, the size of the dots, and the like can be adjusted. By replacing the mask, the shape and size of the beam spot can be changed. In addition, the size of the beam spot can be changed by changing the imaging magnification (reduction ratio).

Although the processing in which the transfer layer remains in a line shape or a dot shape on the substrate surface has been described as an example, the processing may be performed such that the substrate surface is drilled in a line shape or dot shape by laser irradiation.

The shape of the through hole of the mask is not limited to the rectangle, and may be appropriately selected depending on the shape of the dot or line to be formed.

Although the example which moved the incidence position of the laser beam on a board | substrate with the XY stage was demonstrated, the incidence position can also be moved by changing the advancing direction of a laser beam with a galvano scanner.

Next, referring to Fig. 27A, the laser processing according to the seventh embodiment has two laser light sources, one laser light source emits a pulsed laser beam, and one laser light source emits a continuous wave laser beam. The apparatus will be described.

The laser light source 1a is, for example, an Nd: YAG laser oscillator including a wavelength conversion unit, and emits a pulsed laser beam of the fourth harmonic (wavelength 266 nm) of the Nd: YAG laser. The pulse width is 10 mW, for example. The pulsed laser beam emitted from the laser light source 1a enters the half-wave plate 69a and becomes linearly polarized light such that it becomes a P wave with respect to the polarizing plate 67.

The laser light source 1b is, for example, a semiconductor laser oscillator and emits a continuous wave laser beam having a wavelength of 808 nm. The continuous wave laser beam emitted from the laser light source 1b enters the half-wave plate 69b and becomes linearly polarized light such that it becomes an S wave with respect to the polarizing plate 67.

The pulsed laser beam that has emitted the half-wave plate 69a passes through an expander 3a which enlarges the beam diameter to form parallel light, and a mask 5 having a rectangular through hole, for example, and thus the front side of the polarizing plate 67 ( An incident angle of 45 ° is incident on the surface of the table.

The continuous wave laser beam emitted from the half-wave plate 69b passes through the expander 3b which enlarges the beam diameter and becomes parallel light, is reflected by the reflector 68, and is reflected on the surface of the back side of the polarizing plate 67. Incident at an incident angle of 45 °.

The polarizing plate 67 transmits a P-fine pulsed laser beam and reflects a S-wave continuous wave laser beam. The polarizing plate 67 superimposes the pulse laser beam radiate | emitted from the laser light source 1a, and the continuous wave laser beam radiate | emitted from the laser light source 1b on the same optical axis.

The pulsed laser beam passing through the polarizing plate 67 and the continuous wave laser beam reflected by the polarizing plate 67 are focused by the objective lens 6, pass through the galvano scanner 7, and enter the substrate 12. .

The XY stage 8a used as the support stand of the board | substrate 12 can move the board | substrate 12 in the two-dimensional plane parallel to the surface of the board | substrate 12. As shown in FIG. The XY stage 8a is controlled by the controller 11 to move the substrate 12 to a desired position at a desired timing.

In the example of the laser processing method described here, the laser beam from which the X scanner 7a and the Y scanner 7b of the galvano scanner 7 exits the galvano scanner 7 is perpendicular to the substrate 12. It is fixed at the same position as the incident light. By moving the substrate 12 to the XY stage 8a, the incident position of the laser beam on the substrate 12 is moved.

The voice coil mechanisms 9 and 10 respectively move the positions of the mask 5 and the objective lens 6 in parallel in the advancing direction of the pulsed laser beam emitted from the laser light source 1a. The image of the through hole of the mask 5 adjusts the positions of the mask 5 and the objective lens 6 to form an image on the surface of the substrate 12 at a desired image formation magnification (reduction ratio).

With reference to FIG. 27B, the board | substrate 12 which is a process object is demonstrated. On the surface of the base layer 120, the surface layer 121 is formed. The base layer 120 is, for example, a color filter of a liquid crystal display device, and is a resin layer made of polyimide resin, acrylic resin, or the like having a thickness of 1 μm. The surface layer 121 is, for example, an ITO film having a thickness of 0.5 m.

When only the surface layer 121 is removed by laser irradiation, since the underlayer 120 is more easily processed than the surface layer 121, it is difficult to process only the surface layer 121. For example, when the substrate is irradiated with a laser, while the surface layer 12 is not directly processed, the underlayer 120 explodes scattered under the influence of heat transmitted to the underlayer 120, and consequently the surface layer 121 is accompanied. This flies away.

This inventor discovered that it is easy to process only the surface layer 121 by performing laser irradiation after giving preheating to a board | substrate. In the laser processing apparatus shown in Fig. 27A, the substrate 12 is preheated by the continuous wave laser beam emitted from the laser light source 1b, and the holes and the like are made by the pulsed laser beam emitted from the laser light source 1a. Processing.

Next, with reference to FIGS. 28A to 28C, an example of a method of forming a hole by irradiating a pulsed laser after preheating the continuous point laser to a processing point on the substrate will be described.

As shown in Fig. 28A, the processing points 105a, 105b, and 105c are defined on the surface of the substrate 12 to which the continuous wave laser beam (represented by the circular beam spot 95) is irradiated. . The center of the beam spot 95 is located on a straight line connecting the work points 105a to 105c. The XY stage is moved in parallel with this straight line to move the processing points 105a, 105b, and 105c toward the beam spot 95.

As shown in FIG. 28 (B), when the processing point 105a reaches the circumference of the beam spot 95, a continuous wave laser is irradiated to the processing point 105a, and supply of preheating is started.

As shown in FIG. 28C, when the processing point 105a reaches the center of the beam spot 95, one shot of pulse laser is irradiated to the center of the beam spot 95. The beam spot of the pulse laser is shown by the beam spot 96.

The workpiece point 105a is preheated while moving from the circumference of the beam spot 95 to the center. By irradiating the preheated workpiece point 105a with a pulsed laser, processing of the underlying layer can be suppressed and holes can be formed in the surface layer of the substrate.

The substrate 12 is continuously moved to form holes in the processing points 105b and 105c similarly to the processing point 105a.

Irradiation conditions of the continuous wave laser beam used for preheating make a beam spot circular shape of diameter 20mm, and makes the power density on the surface of a board | substrate 0.1 W / cm <2>, for example. Irradiation conditions of the pulse laser beam used for a process make a beam spot a square of 20 micrometers angle, for example, and make the pulse energy density in the surface of a board | substrate into 0.1-0.4 J / cm <2>.

The time for which the processing point is preheated is almost equal to the time for which the processing point moves by the length of the radius of the beam spot of the continuous wave laser. This time becomes about 0.13 second, for example, when the radius of a beam spot is 10 mm and the moving speed of an XY stage is 800 mm / s. By irradiating a pulsed laser to the center of the beam spot of a continuous wave laser beam, even if the moving direction of an XY stage is changed variously, it becomes easy to process according to the preheating time.

Since the preheat applied to the surface of the substrate by irradiation of the continuous wave laser is transmitted to the underlayer, if the preheat applied is too much, the underlayer is processed. Therefore, it is necessary to supply preheating so that the temperature of a base layer may stay below the temperature which is not processed. For example, it is necessary to make the temperature of the underlayer stay below the melting point of the underlayer material.

The ITO film is transparent compared to visible light, but the absorption coefficient for near infrared rays having a wavelength of 808 nm, for example, is not zero. Therefore, light of this wavelength can be used for preheating the ITO film. When light of a wavelength having a larger absorption coefficient of ITO (for example, a wavelength near 1064 nm) is used, improvement in preheating efficiency is expected.

Although an example in which a pulsed laser beam and a continuous wave laser beam are superimposed on the same optical axis has been described, both laser beams may be absent on the same optical axis. When the beam spot of the pulsed laser beam is included in the beam spot of the continuous wave laser beam and both laser beams are irradiated to the substrate, the processing point reaches the circumference of the beam spot of the continuous wave laser beam and then the beam of the pulse laser beam. Preheating can be supplied to the workpiece until the spot is reached.

However, in order to give preheating, it is necessary to make the to-be-processed point reach the irradiation position of a pulsed laser beam after passing inside the beam spot of a continuous wave laser beam. Therefore, it is necessary to make sure that the irradiation position of the pulse laser beam does not coincide with the position of the processing point at the point when the processing point touches the outer circumference of the beam spot of the continuous wave laser beam.

Although the example which forms a hole was demonstrated, you may form a some hole so that a groove may be formed continuously.

Although the example which moved the incidence position of the laser beam on a board | substrate with the XY stage was demonstrated, the incidence position can also be moved by changing the advancing direction of a laser beam with a galvano scanner.

As mentioned above, although this invention was demonstrated along the Example, this invention is not limited to this. For example, it will be apparent to those skilled in the art that various changes, improvements, combinations, and the like are possible.

Claims (41)

(a) A cross section of the laser beam is shaped by a mask having a through hole, and the laser beam passing through the through hole is focused by a lens so that the through hole of the mask is formed on the surface of the object to be processed. A process of making it enter the surface of the object, (b) scanning the laser beam that has passed through the lens so that the incident position of the laser beam moves on the surface of the workpiece, and the through-hole is formed on the surface of the workpiece during scanning of the laser beam; Has a process of processing this object by forming an image, In the step (a), the laser beam is scanned while the optical path length between the mask and the lens and the optical path length from the lens to the surface of the workpiece are kept constant. Processing method. delete The method according to claim 1, The step (b) causes the lens to be displaced in a direction parallel to the traveling direction of the laser beam passing through the lens, and the mask is displaced in a direction parallel to the traveling direction of the laser beam passing through the mask. A laser processing method comprising the step. The method according to claim 1, In the step (a), the laser beam having passed through the through hole is formed on the surface of the workpiece so that the beam spot on the surface of the workpiece has a pair of parallel sides. Incidentally, in the step (b), the laser beam is scanned so that the beam spot moves in a direction parallel to the pair of sides. The method according to claim 1, The intensity distribution on the surface of the workpiece of the laser beam incident on the surface of the workpiece is a distribution in which the intensity at the periphery of the beam spot is larger than the intensity at the center portion. Processing method. The method according to claim 1, The laser beam incident on the surface of the workpiece is a pulsed laser beam, and the step (b) changes the pulse energy so that the pulse energy of the laser beam increases when the incident angle on the surface of the workpiece increases. Laser processing method comprising a. The method according to claim 1, In the step (b), when the incident angle of the laser beam scanning the surface of the object to be processed is changed, the variation of the beam spot area of the laser beam on the surface of the object is small. A laser processing method characterized by displacing the mask and the lens. (c) injecting the laser beam focused on the lens onto the surface of the object; (d) scanning the laser beam so that the incident position of the laser beam moves on the surface of the workpiece, and processing the workpiece, wherein the laser beam from the lens to the surface of the workpiece is A laser processing method comprising the step of scanning the laser beam so that the optical path length does not change. The method according to claim 8, The step (d) includes a step of displacing the lens in the traveling direction of the laser beam passing through the lens such that the optical path length of the laser beam from the lens to the surface of the object is not changed. Laser processing method. The method according to claim 8, And a laser beam incident on the lens is a collimated beam, and the optical path length of the laser beam from the lens to the surface of the workpiece is equal to the focal length of the lens. A laser light source for emitting a laser beam, Support for supporting the object to be processed, A mask having a through hole for shaping a cross section of the laser beam emitted from the laser light source; A condenser lens for condensing a laser beam having a cross section in the mask so that the through hole of the mask is formed on the surface of the object to be supported by the support; A beam scanner which scans the laser beam collected by the condenser lens on the surface of the object under control from the outside; A moving mechanism for moving the mask and the condenser lens under control from the outside; And a control device for synchronizing the scanning by the beam scanner and the movement of the mask and the condenser lens by the moving mechanism, The moving lens is configured to maintain the optical path length between the mask and the condenser lens so that the optical path length from the condenser lens to the processing surface of the laser beam scanned by the beam scanner does not change. And the mask is moved in the traveling direction of the laser beam passing through the condensing lens, and the mask is moved in the traveling direction of the laser beam passing through the mask. delete The method according to claim 11, The moving mechanism has a variation in the area of the image of the through-hole on the surface of the workpiece when the incident angle of the laser beam scanning the surface of the workpiece is varied. And a moving mechanism for moving the mask and the condenser lens so as to reduce the size of the laser processing apparatus. The method according to claim 11, Further, when the laser beam is incident on the surface of the workpiece at a large incident angle, the laser processing apparatus includes a variable attenuator for adjusting the pulse energy of the laser beam emitted from the laser light source and reducing the attenuation rate of the pulse energy. . The method according to claim 11, Furthermore, when the said laser light source emits a pulsed laser beam, it has a pulse energy density converting apparatus which makes the pulse energy density in the beam cross section of the said pulsed laser beam larger in a peripheral part than a center part. The method according to claim 11, And a through hole of the mask having a pair of parallel sides. The method according to claim 16, When defining the X direction and the Y direction orthogonal to each other on the surface of the object to be supported by the support, the beam scanner uses the laser beam focused on the condenser lens on the surface of the object to be processed. An X-direction syringe for scanning in the X-direction and a Y-direction syringe for scanning in the Y-direction, wherein the condensing lens is parallel to the image of the through hole on the surface of the workpiece. A laser processing apparatus characterized by forming a pair of sides in parallel with the X direction. (e) condensing a laser beam with a lens and making it enter the surface of the object; (f) When the incidence position of the laser beam on the workpiece is moved, the variation caused by the shift of the incidence position of the pulse energy density or power density of the laser beam on the surface of the workpiece is suppressed. And moving the incident position of the laser beam within the surface of the workpiece while moving the lens. The method according to claim 18, In the step (f), when the pulse energy density or power density of the laser beam on the surface of the object is suppressed from increasing, the lens is moved so that the focal position of the laser beam is far from the incident position. And when the pulse energy density or power density of the laser beam on the surface of the object is reduced, the lens is moved so that the focal position of the laser beam is close to the incident position. Condensing a laser beam with a lens and making it enter the surface of a workpiece; Incident of the laser beam while moving the lens so as to suppress the variation of the area of the beam spot on the surface of the object to be changed due to the movement of the incidence position when the position of incidence of the laser beam in the object is moved. And moving the position within the surface of the workpiece. A laser light source for emitting a laser beam, A support mechanism for supporting the object, A lens for condensing the laser beam emitted from the laser light source; A beam scanner for changing the advancing direction of the laser beam emitted from the lens to cause the laser beam to enter the surface of the workpiece supported by the support mechanism, and to move the incident position of the laser beam within the surface of the workpiece; A moving mechanism which receives the control signal from the outside and moves the lens; When the beam scanner moves the position of incidence of the laser beam on the surface of the workpiece, the position of the lens is moved so that the change in the pulse energy density or the power density of the laser beam on the surface of the workpiece is suppressed. And a control device for controlling the moving mechanism. The method according to claim 21, When the control device suppresses an increase in the pulse energy density or the power density of the laser beam on the surface of the object to be processed, the control device moves the moving mechanism to move the lens so that the focal position of the laser beam is far from the incident position. And controlling the moving mechanism to move the lens so that the focal position of the laser beam is close to the incident position when suppressing the decrease in the pulse energy density or the power density of the laser beam on the surface of the workpiece. Laser processing apparatus, characterized in that. A laser light source for emitting a laser beam, A support mechanism for supporting the object, A lens for condensing the laser beam emitted from the laser light source; A beam scanner for changing the advancing direction of the laser beam emitted from the lens to cause the laser beam to enter the surface of the workpiece supported by the support mechanism, and to move the incident position of the laser beam within the surface of the workpiece; A moving mechanism which receives the control signal from the outside and moves the lens; When the beam scanner moves the position of incidence of the laser beam on the surface of the workpiece, the moving mechanism is moved to move the position of the lens so as to suppress the variation of the area of the beam spot on the surface of the workpiece. Laser processing apparatus having a control device for controlling. (g) condensing the laser beam with a lens and making it enter the surface of the object; (h) When the position of incidence of the laser beam is moved to the object to be processed, the laser is suppressed so as to suppress the variation due to the movement of the position of incidence of the pulse energy density or power density of the laser beam on the surface of the object to be processed. And moving the incident position of the laser beam within the surface of the object while adjusting the power of the beam using a variable attenuator. A laser light source for emitting a laser beam, A support mechanism for supporting the object, A lens for condensing the laser beam emitted from the laser light source; A beam scanner for changing the advancing direction of the laser beam emitted from the lens to cause the laser beam to enter the surface of the workpiece supported by the support mechanism, and to move the incident position of the laser beam within the surface of the workpiece; A variable attenuator which receives a control signal from the outside and attenuates the power of the laser beam at a variable attenuation rate, To adjust the power of the laser beam so as to suppress a change in the pulse energy density or the power density of the laser beam on the surface of the workpiece when the beam scanner moves the incident position of the laser beam on the surface of the workpiece, And a control device for controlling the variable attenuator. A laser light source for emitting a laser beam, A support mechanism for supporting the object, A first lens for converging or diverging the laser beam emitted from the laser light source, A second lens in which the laser beam passing through the first lens is incident and condenses the incident laser beam; A beam scanner for changing the advancing direction of the laser beam emitted from the second lens to cause the laser beam to enter the surface of the workpiece supported by the support mechanism, and to move the incident position of the laser beam within the surface of the workpiece; , A moving mechanism that receives the control signal from the outside and moves the first lens; When the beam scanner moves the position of incidence of the laser beam on the surface of the workpiece, the position of the first lens is moved so that the change in pulse energy density or power density of the laser beam on the surface of the workpiece is suppressed. To control the moving mechanism, When the numerical aperture of this second lens with respect to the laser beam incident on the second lens is NA1 and the numerical aperture of this second lens with respect to the laser beam passing through the second lens is NA2, NA1 Laser processing apparatus characterized in that / NA2 is two or more. A laser light source for emitting a laser beam, A support mechanism for supporting the object, A beam cross section having a through hole, in which a laser beam emitted from the laser light source enters the through hole, receives a control signal from the outside, and can change the length in one direction of the laser beam cross section passing through the through hole. Forming machine, A lens for condensing the laser beam emitted from the beam sectional shaper; A beam scanner for changing the advancing direction of the laser beam emitted from the lens to cause the laser beam to enter the surface of the workpiece supported by the support mechanism, and to move the incident position of the laser beam within the surface of the workpiece; A control device for controlling the beam cross-sectional shaper so that when the beam scanner moves the incident position of the laser beam on the surface of the object to be processed, the beam cross-section shaper suppresses the variation of the shape of the beam spot on the surface of the object. Laser processing apparatus having a. The method of claim 27, And the beam cross-sectional shaper inclines the through hole from a plane perpendicular to the direction in which the laser beam travels when the cross section of the laser beam is shaped into an elongated shape in one direction. The method according to claim 28, And the beam cross-sectional shaper is capable of rotating the through hole around an axis parallel to the traveling direction of the laser beam. A laser light source for emitting a laser beam, A support mechanism for supporting the object, A lens for condensing the laser beam emitted from the laser light source; A beam scanner for changing the advancing direction of the laser beam emitted from the lens to cause the laser beam to enter the surface of the workpiece supported by the support mechanism, and to move the incident position of the laser beam within the surface of the workpiece; The laser beam emitted from the beam scanner is disposed in the optical path until the laser beam is incident on the object to be processed, has a through hole, and has a proximity mask for incident the laser beam passing through the through hole to the object. Furthermore, A moving mechanism that receives the control signal from the outside and moves the lens; When the beam scanner moves the position of incidence of the laser beam on the surface of the workpiece, the position of the lens is shifted so that the change in the pulse energy density or the power density of the laser beam on the surface of the workpiece is suppressed. And a control device for controlling the moving mechanism. delete Adjusting the spread angle of the laser beam emitted from the laser light source, The laser beam is placed at a position away from the surface by a predetermined distance in parallel with the surface of the object to be processed while varying the direction in which the laser beam is adjusted to have the predetermined spreading angle. Irradiating a laser beam that has passed through the through hole to the surface of the workpiece, and transferring the shape of the through hole to the surface of the workpiece; At least one of the predetermined spreading angle and the predetermined distance, the accuracy of the shape of the through hole transferred to the surface of the workpiece, the spreading angle of the laser beam, and the distance between the proximity mask and the surface of the workpiece A laser processing method comprising the step of setting based on a previously obtained relationship. A laser light source for emitting a laser beam of continuous waves, A support mechanism for supporting the object, The laser beam emitted from the laser light source is incident, and based on the instrument signal supplied from the outside, it is possible to switch between the state in which the incident laser beam is emitted in the first direction and the state in which the laser beam is not emitted in the first direction. Optical system, A mask having a rectangular through-hole, the laser beam having exited the optical system in the first direction entering the through-hole, and shaping a cross section of the laser beam; A lens for condensing the laser beam emitted from the mask to form a rectangular through hole of the mask on the surface of the object to be supported by the support mechanism; A moving mechanism capable of moving the support mechanism on the basis of a control signal given from the outside to move the position at which the laser beam exiting the lens is incident on the object to be processed, within the surface of the object; A mask rotating mechanism for rotating the mask around an axis parallel to the optical axis of the laser beam passing through the through hole of the mask, based on a control signal supplied from the outside; The instrument signal is sent to the optical system, the moving mechanism controls the moving mechanism to move the position of incidence of the laser beam into the object to be processed in the second direction, and the moving mechanism is incident to the laser beam on the surface of the object to be processed. Before moving the position in this second direction, the mask rotating mechanism rotates the mask to parallel the second direction with the imaged side of the rectangular through hole on the surface of the object to be processed. And a control device for controlling the mask rotating mechanism. (i) injecting a laser beam of a continuous wave emitted from a laser light source into an optical system capable of switching between a state in which the incident laser beam is emitted in the first direction and a state in which the laser beam is not emitted in the first direction; (j) A laser beam emitted from the optical system in the first direction is incident on a mask having a rectangular through hole to shape a cross section, and is condensed with a lens to form an image of the through hole on the surface of the workpiece. Forming process, (k) including a step of moving the image of the through hole in a direction parallel to the side on which the image is located, on the surface of the workpiece; When forming a discrete pattern of dots on the surface of the object, in the step (i), the laser beam is intermittently emitted from the optical system in the first direction, When forming a linear pattern on the surface of a workpiece, in the step (i), the laser beam is emitted continuously from the optical system in the first direction. The method of claim 34, wherein Moreover, after the step (k), (l) rotating the mask around an axis parallel to the traveling direction of the laser beam such that the image of the through hole rotates on the surface of the workpiece; (m) The laser processing characterized by including the process of moving the image of the said through-hole rotated on the surface of a to-be-processed object in the direction parallel to the side with the image of the said through-hole rotated in the said process (l). Way. A support mechanism for supporting the object, A first laser light source for emitting a pulsed laser beam, A second laser light source for emitting a continuous wave laser beam, On the surface of the object to be supported by the support mechanism, a pulsed laser beam emitted from the first laser light source and a continuous wave laser beam emitted from the second laser light source are beams of a pulsed laser beam inside a beam spot of the continuous wave laser beam. An optical system that irradiates the spot to be included, And a moving mechanism for moving the beam spot of the pulsed laser beam and the continuous wave laser beam on the surface of the object to be supported by the support mechanism. The method of claim 36, The optical system changes at least one optical axis of the pulsed laser beam emitted from the first laser light source or the continuous wave laser beam emitted from the second laser light source so that the pulsed laser beam and the continuous wave laser beam travel along the same optical axis. And irradiating a laser beam to the surface of the object to be supported by the support mechanism. (n) emitting a pulsed laser beam from the first laser light source, and emitting a continuous wave laser beam from the second laser light source; (o) Defined on the surface of the object to be formed on the surface of the underlayer and the underlayer, and having a surface layer formed of a material that is less difficult to be processed by laser irradiation than the material of the underlayer. After the continuous wave laser beam emitted from the second laser light source is irradiated to the work point and preheated, the pulsed laser beam emitted from the first laser light source is irradiated to the work point, and the surface layer of the object is processed. A laser processing method comprising the step of forming a hole. The method of claim 38, In the step (o), the continuous wave laser beam emitted from the second laser light source is preheated to the object to be processed so that the temperature of the underlying layer remains below the melting point of the underlying layer. Way. The method of claim 38, In the step (o), the beam spot of the pulsed laser beam is included in the beam spot of the continuous wave laser beam, and the pulsed laser beam from the outside of the beam spot of the continuous wave laser beam within the surface of the workpiece. Laser processing characterized by moving the certain processing point toward the irradiation position of and passing the certain processing point to the irradiation position of the pulsed laser beam after passing inside the beam spot of the continuous wave laser beam. Way. The method of claim 40, In the step (o), the beam spot of the continuous wave laser beam on the surface of the workpiece is made circular, and the beam spot of the pulsed laser beam is placed at the center of the circle.

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