WO2012039057A1 - レーザ加工装置 - Google Patents

レーザ加工装置 Download PDF

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Publication number
WO2012039057A1
WO2012039057A1 PCT/JP2010/066560 JP2010066560W WO2012039057A1 WO 2012039057 A1 WO2012039057 A1 WO 2012039057A1 JP 2010066560 W JP2010066560 W JP 2010066560W WO 2012039057 A1 WO2012039057 A1 WO 2012039057A1
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WO
WIPO (PCT)
Prior art keywords
light
laser
processing
condensing
workpiece
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Application number
PCT/JP2010/066560
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English (en)
French (fr)
Japanese (ja)
Inventor
望月　学
満 板持
浩義 廣田
Original Assignee
パイオニア株式会社
株式会社パイオニアＦａ
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パイオニア株式会社, 株式会社パイオニアＦａ filed Critical パイオニア株式会社
Priority to JP2011517708A priority Critical patent/JP4803566B1/ja
Priority to CN201080003896.9A priority patent/CN102612419B/zh
Priority to PCT/JP2010/066560 priority patent/WO2012039057A1/ja
Publication of WO2012039057A1 publication Critical patent/WO2012039057A1/ja

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/0604—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/50—Working by transmitting the laser beam through or within the workpiece
    • B23K26/53—Working by transmitting the laser beam through or within the workpiece for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/50—Working by transmitting the laser beam through or within the workpiece
    • B23K26/57—Working by transmitting the laser beam through or within the workpiece the laser beam entering a face of the workpiece from which it is transmitted through the workpiece material to work on a different workpiece face, e.g. for effecting removal, fusion splicing, modifying or reforming

Definitions

  • the present invention relates to a technical field of a laser processing apparatus that performs processing by, for example, forming a condensing part of a laser beam on the surface of a material to cause a change in the structure of the material in the vicinity of the condensing part.
  • the laser light emitted from the laser light source is condensed on the surface of the material placed on the stage, and a chemical or physical change due to heat treatment is caused in the minute volume near the condensing part. Processing with.
  • the material surface is not necessarily flat, and the positional relationship between the condensing part of the laser beam and the material surface changes as appropriate during processing, and thus condensing control is required to follow the change in the positional relationship.
  • a prior art document to be described later describes a configuration in which laser light emitted from a laser light source is split into two, and one is processed laser light and the other is distance measuring laser light.
  • the condensing position of the processing laser beam is controlled by calculation based on an electric signal generated from the reflected light of the ranging laser beam. For this reason, it is supposed that the condensing part of the laser beam for processing can be moved following the change in the positional relationship between the condensing part of the laser beam and the material surface.
  • the present invention has been made in view of, for example, the above-described problems, and can accurately perform high-precision and high-speed processing by appropriately following the focusing position of the laser beam for processing with respect to the structure of the material surface. It is an object to provide a laser processing apparatus.
  • a laser processing apparatus of the present invention is a laser processing apparatus that performs processing by condensing laser light on a processing target, and is a first processing unit that performs processing on the processing target.
  • a first condensing unit that performs processing by forming a first condensing unit; and a second condensing unit that forms a second condensing unit that is a condensing unit of the second laser light at a predetermined position of the object to be processed.
  • the light receiving means Based on the light collecting means, the light receiving means for receiving the reflected light of the second laser light reflected by the workpiece, the second light based on the reflected light of the second laser light received by the light receiving means.
  • a focus servo means for determining a position of the light collecting portion; and Control means for controlling the operation of the first light condensing means so as to form the first light condensing part at a position determined based on the position, and the numerical aperture of the first light condensing means is the second It is larger than the numerical aperture of the light collecting means.
  • An embodiment of a laser processing apparatus of the present invention is a laser processing apparatus that performs processing by condensing laser light on a processing object, and irradiates the first laser light for processing the processing object.
  • a first condensing unit that performs processing by forming a second condensing unit that forms a second condensing unit that is a condensing unit of the second laser light at a predetermined position of the processing target; Based on the light receiving means for receiving the reflected light of the second laser light reflected by the workpiece and the reflected light of the second laser light received by the light receiving means, the position of the second condensing unit A focus servo means for determining the position and the position of the second light collecting section. Control means for controlling the operation of the first light collecting means so as to form the first light collecting portion at a position where the first light collecting means is formed, and the numerical aperture of the first light collecting means is the opening of the second light collecting means. Greater than the number.
  • a first laser beam for processing a processing object such as a glass substrate having a film structure on the surface or an opaque material
  • a second laser beam for focus control for operating the focus servo means for adjusting the focus for example, a first laser beam for processing a processing object such as a glass substrate having a film structure on the surface or an opaque material, and the first laser beam.
  • a second laser beam for focus control for operating the focus servo means for adjusting the focus.
  • the first irradiation means is a laser light source that irradiates the processing object with the first laser light for processing.
  • the first condensing means includes, for example, a condensing lens that can move in the optical axis direction of the first laser light, and condenses the first laser light at a predetermined position on the front surface or the back surface of the workpiece. A condensing part is formed.
  • the surface of the object to be processed indicates a surface relatively close to the first emitting means serving as the light source of the first laser light, among the surfaces of the object to be processed by the first laser light. It is.
  • the back surface of the object to be processed is intended to indicate a surface existing on the side opposite to the surface through the object to be processed among the surfaces of the object to be processed by the first laser beam.
  • the first laser light is incident on the inside of the processing object from the front surface, passes through the processing object, and forms a first condensing portion on the back surface.
  • the second irradiation means is a laser light source that irradiates the workpiece with a second laser beam different from the first laser beam.
  • the wavelength of the second laser light is preferably different from the wavelength of the first laser light, but may be the same.
  • the second condensing unit includes, for example, a condensing lens that can move in the optical axis direction of the second laser light, and condenses the second laser light onto the object to be processed to form a second condensing unit.
  • the second condensing means may condense the second laser light on the surface of the processing object, may condense it inside the processing object, or may condense it at other positions. May be.
  • the first irradiating means and the second irradiating means are preferably arranged at a predetermined interval in a plane in which the optical axes of the first laser light and the second laser light are parallel and orthogonal to the optical axis.
  • the predetermined interval is an interval in which the light beam of the first laser light irradiated from the first irradiation unit and the light beam of the second laser beam irradiated from the second irradiation unit do not overlap each other. It is set according to the luminous flux angle of light.
  • the first laser beam and the second laser beam are spaced apart from each other within a plane orthogonal to the optical axis direction of each laser beam.
  • the light is condensed at separate positions.
  • the return light reflected by the workpiece enters the light receiving means after passing through the optical path through which the second laser light has passed.
  • the light receiving means uses, for example, an astigmatism method to focus an electric signal indicating whether or not the second laser beam is focused on a desired position on the object to be processed and, if not focused, an amount of defocus. Input to servo means. Further, the light receiving means may detect the amount of focus deviation by some other method such as a knife edge method based on the return light of the second laser light.
  • the focus servo means is a servo mechanism for focusing the second laser beam on the workpiece.
  • the focus servo unit moves, for example, the second condensing unit so as to correct the focus shift amount of the second laser light grasped from the electric signal input from the light receiving unit. Therefore, for example, even when the surface of the workpiece has irregularities or warpage, and the optical path length from the second irradiation means changes, it is possible to readjust the focus with high accuracy and high speed.
  • the control means moves the focus position of the first laser light in the optical axis direction in accordance with the movement of the focus position of the second laser light by the focus servo means.
  • the control means moves the focus position of the first laser light in synchronization with the movement of the focus position of the second laser light by the focus servo means.
  • the control unit receives an electric signal indicating the focus shift of the second laser beam similar to that received by the focus servo unit, or an electric signal indicating the movement amount of the focus position based on the focus shift amount, and the like.
  • the first condensing means is moved in the optical axis direction of the first laser light according to the input. For this reason, the focus of the first laser beam can be readjusted with high accuracy and high speed in accordance with the unevenness and warpage of the surface of the workpiece. As a result, high-precision laser processing of the workpiece is possible.
  • the numerical aperture of the first light converging means is set larger than the numerical aperture of the second light converging means. Specifically, this is to indicate that the first laser light is condensed by a condensing lens having a larger numerical aperture than the condensing lens that condenses the second laser light.
  • Such a configuration leads to stabilization of the operation of the focus servo means, such as reducing the influence on the focus servo due to disturbances such as vibration of the apparatus.
  • the numerical aperture of the second condensing means is a value determined based on the thickness between the front surface and the back surface of the processing object and the refractive index. That's it.
  • the first laser light for processing is applied to the front surface or the back surface of the processing object by the focus servo control based on the reflected light from the processing object of the second laser light. Focus on accuracy.
  • the processing object is a transparent material having a certain degree of transparency to the laser light
  • the light receiving means for detecting the defocus of the second laser light is from the surface of the processing object.
  • the reflected light and the reflected light from the back surface that has passed through the workpiece are incident.
  • astigmatism method which is a general defocus detection method
  • astigmatism is generated for such reflected light.
  • the astigmatic difference based on astigmatism in the reflected light from the front surface and the back surface of the workpiece may interfere with each other.
  • Such astigmatism appears as a phase difference of the reflected light of the second laser light incident on the light receiving means, for example, as a scale indicating the defocus of the second laser light.
  • the astigmatic difference in the reflected light from the front and back surfaces of the workpiece interferes with each other, it is possible to detect an appropriate defocus of the second laser light from the reflected light of the second laser light received by the light receiving means. This leads to a malfunction of the focus servo means. Therefore, it is preferable that the astigmatic difference in the reflected light of the second laser light is set to be small for focus control by a suitable focus servo means.
  • the case where the astigmatism from the front and back surfaces of the processing object interferes with each other means, for example, that the astigmatism in reflected light from each of the front and back surfaces of the processing object is the front and back surfaces of the processing object. (That is, the optical path length of the second laser light between the front surface and the back surface of the workpiece) becomes relatively larger than a predetermined reference.
  • the astigmatic difference relates to the detectable range of the focus shift of the second laser beam in the light receiving means, setting it extremely small leads to narrowing the operating range of the focus servo means. This can also hinder accurate focus control by the focus servo means.
  • the astigmatic difference changes according to the numerical aperture of a condensing lens that is an example of the second condensing means, and in a predetermined region of the numerical aperture, the reciprocal of the numerical aperture. And the astigmatic difference are related by a quadratic function. Therefore, in order to operate the focus servo means appropriately, the numerical aperture of the second light collecting means is set within an appropriate range with respect to the optical path length of the second laser light between the front surface and the back surface of the workpiece. It is preferable. Note that the optical path length between the front surface and the back surface of the workpiece is determined by the thickness and refractive index between the front surface and the back surface of the workpiece.
  • the astigmatism difference from the front surface and the back surface of the workpiece has a predetermined distance. It is preferable that they are separated from each other. For example, it is preferable that the distance between the front surface and the back surface of the workpiece is at least one time as large as the astigmatic difference. Under the condition, the condition that the astigmatic difference is less than half of the quotient obtained by dividing the thickness of the workpiece by the refractive index is derived. The permissible condition of the numerical aperture of the second condensing means having a quadratic function relation is determined for the astigmatic difference thus conditioned.
  • the focus servo means can be suitably operated even on the workpiece having transparency to the second laser light, and appropriate focus control can be performed.
  • the appropriate numerical aperture of the second light collecting means changes according to the thickness of the workpiece.
  • a thickness of about 0.5 mm is often adopted as the thickness of the processing target.
  • the numerical aperture of the second light collecting means may be set to be 0.1 or more.
  • the first condensing means is located at a position determined based on the position of the second condensing unit on the front surface or the back surface of the processing object. 1 Condensing part is formed.
  • the first condensing unit is configured to be able to move the first condensing part of the first laser light between the front surface and the back surface of the workpiece.
  • the first condensing unit includes a condensing lens that condenses the first laser light and an actuator that moves the condensing lens in the optical axis direction of the first laser light.
  • the actuator moves the first condensing unit by moving the condensing lens in the optical axis direction of the first laser light by a predetermined movement amount determined according to the thickness of the workpiece.
  • the predetermined movement amount corresponds to the optical distance between the front surface and the back surface in the optical axis direction of the first laser light, which is determined by the thickness and refractive index of the workpiece.
  • the first and second irradiation means when the first and second irradiation means irradiate laser light, the first and second irradiation means irradiate laser light.
  • the apparatus further includes moving means for relatively moving the first laser beam and the workpiece.
  • the moving means is, for example, an actuator that can move or rotate the stage on which the workpiece is fixed in a plane orthogonal to the optical axis direction of the first laser beam.
  • the moving means moves the stage relative to the first laser beam by moving the stage during the irradiation of the first laser beam and the second laser beam.
  • the modified region is intermittently or continuously formed along the movement of the processing object on the front surface or the back surface of the processing object by the first laser light irradiated intermittently or continuously. For this reason, it becomes possible to process a desired position on the front surface or the back surface of the processing object.
  • the moving means may be an actuator or the like that moves the first irradiation means for irradiating the first laser light as another aspect.
  • the actuator moves or rotates, for example, a laser light source, which is an example of the first irradiation means, in a plane perpendicular to the optical axis direction of the first laser light during irradiation of the first laser light and the second laser light.
  • the processing object and the first laser beam are moved relative to each other. Even if such a configuration is adopted, it is possible to receive the same effects as those described above.
  • an actuator that moves the first condensing means that condenses the first laser light on the object to be processed may be employed. According to such an actuator, it is possible to change the optical path of the first laser light by moving the first condensing means, and to move the first laser light relatively with respect to the workpiece, and the same effect as described above. Can enjoy.
  • the present invention is not limited to the above-described configuration, and other configurations that can realize the relative movement between the first laser beam and the workpiece by any mechanical or optical means may be similarly employed.
  • the second condensing means is spaced a predetermined distance from the surface of the processing object in the optical axis direction of the second laser light in the processing object.
  • the second light collecting part is formed at a predetermined position.
  • the second laser light is collected not at the surface but at a position separated in the depth direction with respect to the workpiece that is transparent to the second laser light, such as a transparent material.
  • the size of the beam spot of the second laser beam at the second focusing point formed on the surface of the workpiece is larger than that when the second laser beam is focused on the surface of the workpiece.
  • the size of the beam spot on the surface of the workpiece is relatively large, the influence of the defocus of the second laser beam due to the surface surface of the workpiece and the minute irregularities such as the structure is relatively To drop. For this reason, it is possible to suppress the influence on the operation of the focus servo means due to such minute unevenness.
  • the range of the position of the second light collecting portion formed in this aspect is that the above-described focus control can be appropriately performed, and the influence on the focus control due to the unevenness of the surface of the workpiece is eliminated as much as possible.
  • the purpose is to indicate a possible range.
  • position adjustment by a servo is performed so that the second light collecting unit is positioned at a predetermined position appropriately determined from within such a range.
  • the laser processing apparatus includes the first irradiation unit, the second irradiation unit, the first light collecting unit, the second light collecting unit, the light receiving unit, and the focus servo. Means and control means.
  • the laser processing apparatus 1 is a laser beam L1 for processing and a focus of the laser light L1 on a processing target object 50 such as a glass substrate having a film structure or an opaque material.
  • a laser beam L2 for focus control for operating a focus servo for adjustment is emitted.
  • FIG. 1 is a schematic diagram showing the overall configuration of the laser processing apparatus 1.
  • the laser processing apparatus 1 includes a control unit 11, a stage 12, a focus control optical system 2 mainly related to emission of a laser beam L ⁇ b> 2 for focus servo control, and a main processing tool.
  • a control unit 11 a stage 12
  • a focus control optical system 2 mainly related to emission of a laser beam L ⁇ b> 2 for focus servo control
  • a main processing tool a main processing tool.
  • Two optical systems including a processing optical system 3 related to emission of the laser light L1 are provided.
  • the control unit 11 is an arithmetic unit, and controls the operation by supplying a control signal to each unit of the laser processing apparatus 1.
  • the control unit 11 further includes memory storage means for storing an operation program, performs an operation according to an electric signal from each unit, and supplies a control signal based on the operation result to each unit.
  • the stage 12 is a member on which the workpiece 50 is fixed and placed.
  • the stage 12 is supported by a stage actuator 12a.
  • the stage actuator 12a includes a drive amplifier that supplies current in accordance with a control signal supplied from the control unit 11, and includes an actuator that moves the stage 12 in response to supply of current from the drive amplifier.
  • the stage actuator 12 typically moves or rotates the stage 12 in a plane orthogonal to the optical axes of the laser beam L1 and laser beam L2 for processing (that is, in the XY plane in FIG. 1). By such movement or rotation of the stage 12, the workpiece 50 placed on the stage 12 moves relative to the condensing part F1 of the laser light L1.
  • the processing laser light L 1 is scanned linearly, for example, by moving the stage 12 in a state where the laser light L 1 is focused on the surface of the processing target object 50, and the surface of the processing target object 50.
  • a modified region is formed in a desired region.
  • the focus control optical system 2 includes a focus light source 21, a beam splitter 22, a quarter-wave plate 23, a focusing condenser lens 24, a cylindrical lens 25, and a quadrant PD (Photo (Detector: light receiving element). 26 and a calculation unit 27.
  • the focus light source 21 is an example of the second emission means of the present invention, and includes, for example, a laser diode for generating laser light and an application means for applying a high-frequency superimposed pulse to the generated laser light.
  • the laser beam L2 for focus control is emitted.
  • the laser beam L2 is an example of the second laser beam of the present invention, and is, for example, a laser beam having a wavelength of about 680 nm on which high frequency superimposition has been performed.
  • the laser light L2 emitted from the focusing light source 21 passes through the beam splitter 22 and the quarter wavelength plate 23 and enters the focusing condenser lens 24.
  • the beam splitter 22 is disposed on the optical path of the laser beam L2, and emits the incident laser beam L2 in the direction of the focusing condenser lens 24, and returns the laser beam L2 incident through the focusing condenser lens 24.
  • L3 is reflected and emitted in the direction of the cylindrical lens 25.
  • the quarter-wave plate 23 is a quartz plate or the like having a refractive index corresponding to the wavelength of the laser beam L2, which is disposed on the optical path of the laser beam L2 that has passed through the beam splitter 22.
  • the quarter-wave plate 23 causes a phase difference in the passing laser beam L2, and converts linearly polarized light into circularly polarized light or elliptically polarized light.
  • the focusing condenser lens 24 will be described by referring to the upper surface S1 of the workpiece 50 placed on the stage 12 (the surface above the Z axis in FIG. 1, hereinafter simply referred to as “upper surface S1”.
  • the surface below the axis is a lens that focuses the laser light L2 on the surface (simply referred to as “lower surface S2”) to form a condensing portion F2.
  • the focusing condenser lens 24 is supported by a focusing lens block 24a.
  • the numerical aperture of the focusing condenser lens 24 is determined based on the thickness of the workpiece 50 in the Z direction, as will be described later.
  • the numerical aperture of the focusing condenser lens 24 is preferably determined in consideration of the influence of the reflected light of the laser light L2 from the lower surface S2 of the workpiece 50.
  • the numerical aperture of the focusing condenser lens 24 is set to be larger than 0.1.
  • the focusing lens block 24a supports the focusing condenser lens 24, and moves to move the focusing condenser lens 24 together with the supporting member in the optical axis direction of the laser light L2 (that is, the Z direction in FIG. 1).
  • the moving member is, for example, an actuator such as a voice coil that can move the focusing lens 24 with a thrust according to a focus shift and a focus error signal FE voltage supplied from the calculation unit 27.
  • the focus lens block 24a moves the focus position of the laser beam L2 in the Z direction by moving the focus condenser lens 24 in the Z direction.
  • the focusing lens 24 and the focusing lens block 24a include a linear scale 24b for detecting the position of the focusing lens 24 (typically, the position of the laser light L2 in the optical axis direction).
  • the linear scale 24b is a device capable of detecting the position of the focusing condenser lens 24 moved by the focusing lens block 24a by optical, magnetic, or some other means.
  • the linear scale 24 b outputs the detected position data of the focusing condenser lens 24 to the calculation unit 27.
  • a part of the laser beam L2 that forms the condensing part F2 is reflected on the upper surface S1 of the workpiece 50.
  • a part of the laser beam L2 that passes through the workpiece 50 is reflected on the lower surface S2 of the workpiece 50.
  • These reflected lights are emitted upward as the return light L3.
  • the return light L3 enters the beam splitter 22 through the focusing condenser lens 24 and the 1 ⁇ 4 reflector 23, is reflected by the beam splitter 22, and enters the quadrant PD 26 through the cylindrical lens 25.
  • the cylindrical lens 25 is a semi-cylindrical lens which is an example of a component of the light receiving means in the present embodiment.
  • the cylindrical lens 25 adds astigmatism by changing the spot shape of the return light L3 that passes therethrough.
  • the return light L3 passing through the cylindrical lens 25 is in a first direction (for example, the X direction in FIG. 1) orthogonal to the optical axis direction of the return light L3 (for example, the Y direction in FIG. 1).
  • the optical axis direction and the second direction (for example, the Z direction in FIG. 1) orthogonal to the first direction have different light collection characteristics.
  • the quadrant PD 26 is an example of a component of the light receiving means in the present embodiment, and is arranged at the focus position of the return light L3 when the laser light L2 is focused on the upper surface S1 of the workpiece 50.
  • the 4-split PD 26 includes four light receiving elements that receive the return light L3 and output a voltage corresponding to the amount of light, and a calculation unit that measures and calculates the voltage supplied from each light receiving element.
  • the return light L3 forms a circular beam spot in the quadrant PD 26 at the focus position due to a change in the condensing characteristic of the cylindrical lens 25, and when the focus position is deviated, the return light L3 is in the first direction or the second direction.
  • An elliptical beam spot having one of the major axes is formed.
  • the sum of the voltages output from the light-receiving elements A and C and the voltage output from the light-receiving elements B and D are as follows.
  • a focus error signal FE having a voltage corresponding to the difference from the sum of the two is generated and input to the calculation unit 27.
  • the laser beam L2 When the laser beam L2 is appropriately focused on the upper surface S1 of the workpiece 50 (that is, when the condensing unit F2 is the focal point of the laser beam L2), the laser beam L2 enters the quadrant PD 26 via the cylindrical lens 25.
  • the light spot shape is circular.
  • the sum of the voltages output from the light receiving elements A and C is equal to the sum of the voltages output from the light receiving elements B and D, and the voltage of the focus error signal FE is “0”.
  • the spot shape of the return light incident on the quadrant PD 26 is elliptical.
  • the sum of the voltages output from the light receiving elements A and C or the sum of the voltages output from the light receiving elements B and D becomes greater than the other depending on the direction in which the focus is shifted.
  • the voltage of the error signal FE is “0>” or “0 ⁇ ”.
  • the 4-split PD 26 is connected to the PD actuator 26a, and can move within a predetermined range in the optical axis direction of the return light L3 by the operation of the PD actuator 26a.
  • the PD actuator 26a has a drive amplifier that supplies a drive current according to a control signal indicating the Z-axis target value supplied from the control unit 11, for example, and moves the quadrant PD 26 according to the drive current.
  • the calculation unit 27 Based on the focus error signal FE supplied from the 4-split PD 26, the calculation unit 27 detects whether or not the focus of the light condensing unit F2 is deviated and, if it is deviated, detects the deviation amount.
  • the calculation unit 27 supplies a control signal including the detected focus shift amount to the focus lens block 24a and the processing lens block 33a.
  • the configuration of the processing optical system 3 of the laser processing apparatus 1 will be described.
  • the processing optical system 3 includes a processing light source 31 that emits a processing laser beam L1, a diverging lens 32, and a processing condensing lens 33.
  • the processing light source 31 is an example of the first emitting means of the present invention, and includes a laser generation unit, a concentrating element, a phase modulator, a resonator, and the like (not shown), and directs the laser light L1 toward the diverging lens 32.
  • the laser beam L1 is an example of the first laser beam of the present invention, and is, for example, an ultraviolet laser.
  • the diverging lens 32 is a lens that adjusts the light beam angle of the incident laser light L1 and emits it in the direction of the processing condenser lens 33.
  • the diverging lens 32 is supported by the D lens block 32a.
  • the D lens block 32a supports the diverging lens 32 and the diverging lens 32 together with the support member in accordance with the control signal supplied from the control unit 11 in the optical axis direction of the laser beam L1 (that is, FIG. 1).
  • a moving member that moves in the Z direction).
  • the moving member is, for example, an actuator such as a voice coil that is driven according to a control signal.
  • the D lens block 32a moves the diverging lens 32 in the Z direction, thereby changing the light beam angle of the laser light L1 to an arbitrary angle, so that the laser light L1 collected by the processing condenser lens 33 is collected. Move the focus position in the Z direction.
  • the D lens block 32a sets the position of the diverging lens 32 according to the control signal from the control unit 11 so that the laser light L1 incident on the processing condenser lens 33 becomes parallel light.
  • the processing condensing lens 33 is a lens that condenses the laser light L1 on the upper surface S1 or the lower surface S2 of the workpiece 50 placed on the stage 12 to form the condensing part F1.
  • the processing condensing lens 33 is supported by a processing lens block 33a.
  • the numerical aperture of the processing condenser lens 33 is set to be at least larger than the numerical aperture of the focusing condenser lens 24.
  • the processing lens block 33a supports the processing condensing lens 33, and moves to move the processing condensing lens 33 together with the supporting member in the optical axis direction of the laser beam L1 (that is, the Z direction in FIG. 1).
  • the moving member is, for example, an actuator such as a voice coil that can move the processing condensing lens 33 with a thrust according to the focus shift and focus error signal FE voltage supplied from the calculation unit 27.
  • the processing lens block 33a moves the focus position of the laser light L1 in the Z direction by moving the processing condenser lens 33 in the Z direction.
  • the processing lens block 33a receives a control signal similar to that received by the focusing lens block 24a, and the processing lens block 33a is moved by the focusing lens block 24a.
  • the laser beam L1 is preferably focused on the upper surface S1 or the lower surface S2 of the workpiece 50 by moving the same amount in the Z direction.
  • the processing condenser lens 33 and the processing lens block 33a include a linear scale 33b for detecting the position of the processing condenser lens 33 (typically, the position of the laser light L2 in the optical axis direction).
  • the linear scale 33b is a device capable of detecting the position of the processing condenser lens 33 moved by the processing lens block 33a by optical, magnetic, or some other means.
  • the linear scale 33 b outputs the detected position data of the processing condenser lens 33 to the calculation unit 27.
  • the positional relationship of the processing optical system 3 with respect to the focusing optical system 2 is set so that the condensing part F1 is formed at a predetermined distance from the condensing part F2 in the XY plane.
  • the positional relationship between the focusing condenser lens 24 and the processing condenser lens 33 is kept constant.
  • the calculation unit 27 notifies the focus lens block 24 a of a change in the position of the processing condenser lens 33 input from the linear scale 33 b and synchronizes the focusing condenser lens 24 with the processing condenser lens 33. To move.
  • the calculation unit 27 notifies the processing lens block 33 a of a change in the position of the focusing condenser lens 24 input from the linear scale 24 b, and synchronizes the processing condenser lens 33 with the focusing condenser lens 24. To move.
  • astigmatism due to the cylindrical lens 25 is imparted to the return light L ⁇ b> 3 incident on the quadrant PD 26.
  • the computing unit 27 can set the focus error signal generation range to a desired value according to the astigmatism based on the astigmatism.
  • the astigmatic difference is the length of an elliptical beam spot incident on two directions orthogonal to the optical axis of the return light L3 in which the astigmatism occurs in the cylindrical lens 25 and perpendicular to each other (for example, the quadrant PD 26).
  • Axis and minor axis directions Differences in the optical axis direction between the respective beam waist positions.
  • FIG. 2 is a graph showing an S-shaped waveform with respect to the voltage of the time-series focus error signal FE corresponding to the return light L3.
  • the focus error signal generation range is, for example, a range of focus shift that can be detected by the four-divided PD 26, and is represented by a distance between ends of the S-shaped waveform on the horizontal axis.
  • the astigmatic difference is represented by the distance between peaks of the focus error signal FE voltage on the horizontal axis in the S-shaped waveform.
  • a focus error signal is generated by increasing the amount of astigmatism (and hence astigmatism) generated by the cylindrical lens 25 or by increasing the astigmatism difference by reducing the numerical aperture of the focusing condenser lens 24.
  • the range becomes wider.
  • the reflected light component reflected on the upper surface S1 of the workpiece 50 and the reflected light component reflected on the lower surface S2 of the laser light L2 enter the quadrant PD 26 as the return light L3.
  • the computing unit 27 preferably computes the amount of focus deviation from the focus error signal FE based on the reflected light component from the upper surface S1 of the workpiece 50 out of the return light L3 incident on the quadrant PD 26. Therefore, in the return light L3, it is preferable that the reflected light component reflected on the upper surface S1 of the workpiece 50 and the reflected light component reflected on the lower surface S2 can be appropriately distinguished.
  • the focus error signal FE shown in FIG. 2 the relationship between the reflected light component reflected on the upper surface S1 of the workpiece 50 incident on the quadrant PD 26 and the reflected light component reflected on the lower surface S2 is shown in FIG.
  • the return light L3 the reflected light component reflected on the upper surface S1 and the reflected light component reflected on the lower surface S2 of the workpiece 50 pass through the cylindrical lens 25, respectively.
  • a similar astigmatic difference is added.
  • the S-shaped waveform based on the reflected light component from the upper surface S ⁇ b> 1 of the workpiece 50 and the S-shaped waveform based on the reflected light component from the lower surface S ⁇ b> 2 are mutually the upper surface S ⁇ b> 1 of the workpiece 50.
  • the optical path length between the lower surface S2 that is, the distance between the upper surface S1 and the lower surface S2 determined by the Z-direction thickness T and the refractive index N of the workpiece 50).
  • the astigmatic difference of the reflected light component from the upper surface S1 and the astigmatic difference of the reflected light component from the lower surface S2 overlap, it is appropriate according to the focus shift of the laser light L2 on the upper surface S1 of the workpiece 50.
  • the focus error signal FE is not output, and an accurate focus operation may not be performed.
  • the astigmatic difference of the reflected light component from the upper surface S1 and the astigmatic difference of the reflected light component from the lower surface S2 are separated with a predetermined margin therebetween.
  • the margin is at least one time astigmatic difference or more. In the region where the numerical aperture of the focusing condenser lens 24 is low, the astigmatic difference between the reflected light component reflected on the upper surface S1 and the reflected light component reflected on the lower surface S2 is substantially the same. Become.
  • the astigmatic difference is preferably less than or equal to half of the optical path length between the upper surface S1 and the lower surface S2 of the workpiece 50. Is set. In other words, the astigmatic difference is set to be equal to or less than half of the interval T / N between the upper surface S1 and the lower surface S2 determined by the thickness T and the refractive index N of the workpiece 50.
  • the processing lens block 33a of the processing optical system 3 processes the laser light L1 by operating the processing condensing lens 33 in synchronization with the focusing operation of the focusing lens 24 in the focus control optical system 2.
  • the object 50 is focused on the upper surface S1 or the lower surface S2.
  • stable focus control equivalent to the stable focus control performed in the focus control optical system 2 can be applied to the laser light L1, and the condensing unit F1 is placed on the upper surface of the workpiece 50 with high accuracy.
  • S1 or the lower surface S2 can be focused.
  • servo control is performed to control the thrust (and hence acceleration) for operating the focusing lens 24 in accordance with the focus shift of the focusing unit F2 of the laser beam L2.
  • the condensing part F1 of the laser light L1 can be switched between the upper surface S1 and the lower surface S2 of the processing object 50 by the operation of the processing lens block 33a.
  • the processing lens block 33a has an optical path in which the focus position of the laser beam L1 depends on the distance between the upper surface S1 and the lower surface S2 of the processing object 50, that is, the Z-direction thickness T and the refractive index N of the processing object 50.
  • the processing condensing lens 33 is moved in the Z direction so as to move by a long distance. This mode of movement is shown in the schematic diagram of FIG.
  • the processing lens block 33a moves the focus position of the laser beam L1 from the upper surface S1 to the lower surface S2 of the processing object 50
  • the processing lens block 33 is moved to the processing object 50 in the direction of the processing object 50 by an interval T between the upper surface S1 and the lower surface S2. Move / N minutes. With this movement, the focus position of the laser beam L1 moves from the upper surface S1 to the lower surface S2 of the workpiece 50.
  • the processing lens block 33a moves the processing condensing lens 33 following the focus control by the focus control optical system 2 in a state where the focus position is moved to the lower surface S2 of the processing object 50.
  • the condensing part F1 of the laser beam L1 can be suitably focused on the lower surface S2 of the workpiece 50.
  • the laser beam L1 causes a modification by vaporization or the like in a minute volume of about 10 cubic micrometers in the vicinity of the condensing portion F1 on the upper surface S1 or the lower surface S2 of the workpiece 50. Therefore, the numerical aperture of the processing condensing lens 33 is determined in accordance with the size of the condensing part F1 corresponding to the volume causing the modification, which is larger than the numerical aperture of the focusing condensing lens 24 as described above. It is preferred that Preferably, the size of the light collecting portion F1 formed at the focus position is adjusted to about 1 square micrometer.
  • the in-plane orthogonal to the optical axis direction of the laser light L1 That is, a minute modified region can be formed on the upper surface S1 and the lower surface S2) of the workpiece 50.
  • the laser processing apparatus 1 controls the processing condensing lens 33 to form the condensing portion F1 inside the processing object 50 such as transparent glass by the operation of the processing focus block 33a.
  • a minute modified region can be formed inside the object 50.
  • the laser beam L1 in the optical axis direction in addition to the improvement of the processing accuracy in the plane orthogonal to the optical axis direction of the laser light L1, the laser beam L1 in the optical axis direction (in other words, the depth inside the processing object 50). In the vertical direction, more modified regions can be formed.
  • a highly accurate cut surface can be obtained.
  • movement in the optical axis direction due to residual error after focus servo close can be suppressed to a minute region of about 10 nanometers, for example.
  • an error range of about 1 micrometer is allowed at the position of the modified region to be formed.
  • the servo gain in focus control is set low.
  • the modified region can be formed with sufficient accuracy.
  • the laser processing apparatus 1 performs focus control by focusing the focusing portion F2 of the focusing laser beam L2 on the upper surface S1 of the processing object 50, and performs the focus control.
  • the condensing part F1 of the processing laser beam L1 is focused on the upper surface S1 of the processing object 50.
  • the processing optical system 1 uses the laser light L1 to process the film structure formed on the upper surface S1 of the processing object 50 or to trim the upper surface S1. And so on.
  • the condensing part of the processing laser beam L1 suitably following the uneven structure formed on the upper surface S1 of the processing object 50 F1 can be focused on the upper surface S1. Therefore, high-precision and high-speed machining can be realized on the upper surface S1, the lower surface S2, or the inside of the workpiece 50 without being affected by the uneven structure due to wrinkles or the like on the upper surface S1 of the workpiece 50.
  • the processing optical system 1 moves the light condensing part F1 of the laser light L1 to the lower surface S2 of the workpiece 50, thereby forming a film structure formed on the lower surface S2.
  • the above processing and the trimming processing of the lower surface S2 can be performed in the same manner.
  • the focus control optical system 2 is configured so that the condensing part F2 of the laser light L2 is not the surface of the processing object 50, as shown in FIG. You may focus on the predetermined depth inside the workpiece 50.
  • the size of the beam spot of the laser beam L2 formed on the surface of the processing object 50 is larger than that in the case where the condensing unit F2 is focused on the surface of the processing object 50. For this reason, the influence on the focus control due to relatively small irregularities such as scratches and structures formed on the surface of the workpiece 50 can be suppressed.
  • FIG. 7 is a schematic diagram showing an overall configuration of the laser processing apparatus 1 ′.
  • the same number is attached
  • a lens block 24c is arranged instead of the focusing lens block 24a.
  • the lens block 24 c includes a moving member that supports the focusing condenser lens 24 and the processing condenser lens 33 and that can move in synchronization with the focusing condenser lens 24 and the processing condenser lens 33 ( (See dashed line).
  • the moving member is an actuator such as a voice coil capable of moving the focusing condenser lens 24 and the processing condenser lens 33 with a thrust according to the focus shift and the focus error signal FE voltage supplied from the calculation unit 27.
  • the lens block 24c moves the focusing condenser lens 24 in the optical axis direction (that is, the Z direction) of the laser light L2 by the operation of the moving member, and at the same time, moves the condenser condenser lens 33 for processing by the same amount. It is moved in the optical axis direction of L1 (that is, the Z direction).
  • the lens block 24c supports and moves the processing condensing lens 33 together with the processing lens block 33a.
  • the processing condensing lens 33 is supported in a movable manner by the processing lens block 33a, and further supported by the lens block 24c in a movable manner along with the processing lens block 33a.
  • the processing lens block 33a moves the processing condensing lens 33 in the Z direction by an interval between the upper surface S1 and the lower surface S2 of the processing object 50 (for example, T / N). ) By moving, the focus position of the laser beam L1 is moved from the upper surface S1 of the workpiece 50 to the lower surface S2.
  • the processing lens block 33a moves the processing condensing lens 33 based on one data of the processing condensing lens 33 detected by the attached linear scale 33b.
  • the processing condenser lens 33 can be moved in synchronization with the movement of the focusing condenser lens 24 based on focus control. For this reason, the laser beam L1 for processing can be focused on the upper surface S1, the lower surface S1, or a desired position inside the processing object 50 without being affected by irregularities such as wrinkles on the upper surface S1 of the processing object 50. .
  • FIG. 8 is a schematic diagram showing an overall configuration of the laser processing apparatus 1 ′′.
  • the same number is attached
  • a lens block 24d is arranged instead of the focusing lens block 24a and the processing lens block 33a.
  • the lens block 24 d includes a moving member that supports the focusing condenser lens 24 and the processing condenser lens 33 and that can move in synchronization with the focusing condenser lens 24 and the processing condenser lens 33 ( (See dashed line).
  • the moving member is an actuator such as a voice coil capable of moving the focusing condenser lens 24 and the processing condenser lens 33 with a thrust according to the focus shift and the focus error signal FE voltage supplied from the calculation unit 27.
  • the lens block 24c moves the focusing condenser lens 24 in the optical axis direction (that is, the Z direction) of the laser light L2 by the operation of the moving member, and at the same time, moves the condenser condenser lens 33 for processing by the same amount. It is moved in the optical axis direction of L1 (that is, the Z direction).
  • the processing condenser lens 33 can be moved in synchronization with the movement of the focusing condenser lens 24 based on focus control. For this reason, the laser beam L1 for processing can be focused on the upper surface S1, the lower surface S1, or a desired position inside the processing object 50 without being affected by irregularities such as wrinkles on the upper surface S1 of the processing object 50. .
  • the processing condenser lens 33 is made independent of the focusing condenser lens 24 by a mechanism (not shown) or manually by an operator of the laser processing apparatus 1 ′′.
  • the focus position of the laser beam L1 can be moved to the upper surface S1, the lower surface S1, or a desired position inside the workpiece 50.
  • the operator moves the processing condensing lens 33 in the Z direction by an amount of movement (T / N) determined according to the thickness T and the refractive index N of the workpiece 50 in the Z direction.
  • the focus position of the laser beam L1 is moved from the upper surface S1 to the lower surface S2 of the workpiece 50.

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  • Physics & Mathematics (AREA)
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  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
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PCT/JP2010/066560 2010-09-24 2010-09-24 レーザ加工装置 WO2012039057A1 (ja)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016189498A (ja) * 2016-08-10 2016-11-04 国立大学法人埼玉大学 基板加工方法及び基板加工装置

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* Cited by examiner, † Cited by third party
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US10029396B2 (en) * 2014-10-30 2018-07-24 Shachihata Inc. Seal carving apparatus and thermal carving machine
CN107530831B (zh) * 2015-06-01 2019-08-09 松下知识产权经营株式会社 激光焊接方法、激光焊接条件决定方法以及激光焊接系统
JP6594680B2 (ja) * 2015-07-07 2019-10-23 日立オートモティブシステムズ株式会社 中空複合磁性部材の製造方法及び製造装置並びに燃料噴射弁

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06190578A (ja) * 1992-12-25 1994-07-12 Isuzu Motors Ltd レーザー加工装置
JPH08250021A (ja) * 1995-03-13 1996-09-27 Canon Inc レーザー光を用いた表面伝導型電子放出素子の製造方法及び製造装置

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5101073B2 (ja) * 2006-10-02 2012-12-19 浜松ホトニクス株式会社 レーザ加工装置
JP5199789B2 (ja) * 2008-08-25 2013-05-15 株式会社ディスコ レーザー加工装置及びレーザー加工方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06190578A (ja) * 1992-12-25 1994-07-12 Isuzu Motors Ltd レーザー加工装置
JPH08250021A (ja) * 1995-03-13 1996-09-27 Canon Inc レーザー光を用いた表面伝導型電子放出素子の製造方法及び製造装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016189498A (ja) * 2016-08-10 2016-11-04 国立大学法人埼玉大学 基板加工方法及び基板加工装置

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