JP2017177194A - Laser processing device and laser processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser processing device and a laser processing method capable of securing a high processing quality, without requiring a protective coating film, by restraining separation of a film, debris and an influence of heat caused accompanied with laser processing.SOLUTION: A processing unit 30 of a laser processing device 10 comprises: a polarization beam splitter 36 for branching a processing laser beam L1 emitted from a laser beam source 12 into a first processing beam L1s and a second processing beam L1p; branching/condensing means 40 for condensing the first processing beam L1s in both-side outer edge parts in a Y direction among a processing scheduled area along an X direction with respect to a workpiece W which relatively moves in the X direction to the processing unit 30; and a processing head 60 for injecting a pressurized liquid using a liquid jet J to the workpiece W which relatively moves in the X direction to the processing unit 30 and irradiating an inside area of the processing scheduled area with the second processing beam L1p by using the liquid jet J as a waveguide.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser processing apparatus and a processing method for processing a workpiece using laser light.

  Conventionally, in order to divide a wafer on which semiconductor devices, electronic parts, etc. are formed into individual chips, a blade dicing machine that cuts by grinding a wafer by rotating a thin grinding wheel at high speed, or condensing a laser inside the wafer Then, a laser dicing apparatus that cuts by forming a modified region has been used.

  In recent years, wafers with inorganic or organic films and metal patterns have been put into practical use, and when they are processed by the above-mentioned dicing apparatus, there has been a problem in that the quality deteriorates. Yes.

  In order to eliminate the peeling, a laser processing apparatus for removing various films and metal patterns in advance prior to dicing is used.

  As such a laser processing apparatus, a direct condensing method (Patent Document 1) that condenses and irradiates laser light directly on a workpiece, or a pressurized liquid is jetted as a liquid jet, and the laser is used as a waveguide. A liquid jet method (Patent Document 2) that irradiates a workpiece with light is known.

Japanese Patent No. 4777783 Japanese Patent No. 5072691

  By the way, the above two methods of the laser processing apparatus have the following merits and demerits, respectively, and the current situation is that they are properly used according to the application.

  FIG. 11 is a diagram illustrating the merits and demerits of the direct focusing method and the liquid jet method of the laser processing apparatus.

  As shown in FIG. 11, in the direct condensing method, there is a degree of freedom in the size of the condensing spot (condensing point), and the work can be processed by concentrating energy in an arbitrary region. The problem of peeling off various films and metal patterns can be solved by, for example, preliminarily cutting the both ends of the planned processing region. However, a part of the processed workpiece that has been heated to a high temperature is scattered, welded, and adhered as debris to the surroundings, resulting in a problem of reducing the quality. This can be avoided by applying a protective film to the surface of the workpiece, but this results in a decrease in throughput and an increase in cost due to the application process and removal process. In addition, heat generated during processing may propagate from the processing region to the outer peripheral portion, which may cause unintended thermal effects such as the device surface and the inside of the substrate.

  On the other hand, in the liquid jet method, since it is covered with liquid at the same time as processing, scattering of debris can be suppressed. Further, since the heat of the processing region and the debris is cooled by the liquid jet, it is possible to suppress the debris welding and the thermal influence on the outer peripheral portion. However, depending on the material and structure of the workpiece, there is a problem that the surface layer film is peeled off from the outer peripheral portion of the processing region, and the quality is deteriorated.

  The present invention has been made in view of such circumstances, suppresses the influence of film peeling, debris, and heat generated by laser processing, does not require a protective coating, and ensures high processing quality. An object is to provide a laser processing apparatus and a laser processing method.

  In order to achieve the above object, a laser processing apparatus according to a first aspect of the present invention includes a laser light source that emits a processing laser beam, a processing unit that laser-processes a workpiece using the processing laser beam, A laser processing apparatus having a moving unit that relatively moves a processing unit and a workpiece, wherein the processing unit converts a processing laser beam emitted from a laser light source into a first laser beam and a second laser beam. A light branching unit that branches into a first direction and a workpiece that is moved relative to the processing unit in the first direction by the moving unit, and is orthogonal to the first direction in the planned processing region along the first direction. The direct condensing means for condensing the first laser light on the outer edge portions on both sides in the direction 2 and the work piece moved relative to the processing unit in the first direction by the moving means Injected with a liquid jet Comprising a processing head that irradiates a second laser beam by using a liquid jet as a waveguide in the inner area sandwiched between the outer edge of each side of the planned processing region.

  In the laser processing apparatus according to the second aspect of the present invention, in the first aspect, the direct condensing means has branch condensing means for branching and condensing the first laser light at the outer edge portions on both sides of the processing scheduled region.

  The laser processing apparatus according to a third aspect of the present invention is the laser processing apparatus according to the second aspect, wherein the branching and condensing means includes two of the first laser beams branched and condensed according to the width of the processing scheduled region in the second direction. It is comprised so that adjustment of the distance of the 2nd direction of a condensing point is possible.

  In the laser processing apparatus according to the fourth aspect of the present invention, in the second aspect, the branching and condensing means comprises a spatial light modulator.

  The laser processing apparatus according to a fifth aspect of the present invention is the laser processing apparatus according to the first aspect, wherein the direct focusing means alternately scans the outer edge portions on both sides of the processing scheduled area at a timing shifted in time. As described above, it has an optical deflecting means for deflecting the first laser beam.

  In the laser processing apparatus according to the sixth aspect of the present invention, in the fifth aspect, the light deflector comprises an acousto-optic element.

  In the laser processing method according to the seventh aspect of the present invention, the first direction among the planned processing regions along the first direction with respect to the workpiece that moves relative to the direct focusing means in the first direction. A first laser processing step of condensing the first laser beam directly on the outer edge portions on both sides in a second direction orthogonal to the workpiece, and a workpiece to be moved relative to the processing head in the first direction A pressurized liquid is ejected from the processing head to the object by a liquid jet, and the second laser beam is applied to the inner region sandwiched between the outer edges on both sides of the region to be processed by using the liquid jet as a waveguide. Irradiating a second laser processing step.

  A laser processing method according to an eighth aspect of the present invention includes, in the seventh aspect, a light branching step that branches the processing laser light emitted from the laser light source into the first laser light and the second laser light.

  In the laser processing method according to the ninth aspect of the present invention, in the eighth aspect, the first laser processing step includes a branching and condensing step of branching and condensing the first laser beam on the outer edge portions on both sides of the processing scheduled region. Have.

  The laser processing method according to a tenth aspect of the present invention is the laser processing method according to the ninth aspect, wherein the branching and condensing step includes two of the first laser beams branched and condensed according to the width in the second direction of the processing scheduled region. An adjusting step of adjusting the distance of the condensing point in the second direction;

  In the laser processing method according to the eleventh aspect of the present invention, in the ninth aspect, the branching and condensing step branches and condenses the first laser light using a spatial light modulator.

  In the laser processing method according to the twelfth aspect of the present invention, in the seventh aspect, the first laser processing step is alternately performed at a timing when the first laser beam is shifted in time at the outer edge portions on both sides of the processing scheduled region. A light deflection step of deflecting the first laser beam so as to scan is provided.

  In the laser processing method according to the thirteenth aspect of the present invention, in the twelfth aspect, the light deflection step deflects the first laser light using an acoustooptic device.

  According to the present invention, the influence of film peeling, debris, and heat caused by laser processing can be suppressed, a protective coating is not required, and high processing quality can be ensured.

Schematic which shows the structure of the laser processing apparatus of 1st Embodiment. Schematic showing a state when the workpiece is irradiated with the first machining light in the direct focusing method machining in the first embodiment The figure for demonstrating the effect when rotating a branch condensing means to (theta) direction Schematic showing a state when a liquid jet is ejected onto a workpiece in the liquid jet processing in the first embodiment Schematic showing the state after the workpiece is processed by the second processing light guided using the liquid jet as a waveguide The figure for demonstrating the effect of the laser processing method in 1st Embodiment. The flowchart which showed the laser processing method using the laser processing apparatus of 1st Embodiment Schematic showing the laser processing apparatus of the second embodiment Schematic showing the laser processing apparatus of the third embodiment Schematic showing the laser processing apparatus of the fourth embodiment Diagram showing the merits and demerits of the direct focusing method and liquid jet method of laser processing equipment

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
First, the first embodiment will be described.

  FIG. 1 is a schematic diagram illustrating a configuration of a laser processing apparatus 10 according to the first embodiment.

  As shown in FIG. 1, the laser processing apparatus 10 according to the first embodiment includes a laser light source 12, an Xθ stage 14, a liquid supply unit 16, a processing unit 30, an autofocus device (AF device) 70, And a control unit 72.

  The laser light source 12 emits a processing laser beam L1 for processing the workpiece W. As the processing laser beam L1, a laser beam having a wavelength region that is difficult to be absorbed by water is used. In this embodiment, preferable conditions of the processing laser beam L1 include a wavelength in the UV wavelength range (less than 400 nm), a pulse width of 1 μm or less, a repetition frequency greater than 1 kHz, an average output of 0.1 to 10 W, The spot diameter at the condensing point is 0.23 to 10 μm.

  The Xθ stage 14 is configured to suck and fix the workpiece W, move in the X direction by a stage drive mechanism (not shown), and rotate in the θ direction. The stage driving mechanism is controlled based on a control signal from the control unit 72. A stage moving mechanism and a processing unit driving mechanism described later are examples of moving means.

  In FIG. 1, the X, Y, and Z directions are orthogonal to each other, the X direction is the horizontal direction, the Y direction is the horizontal direction orthogonal to the X direction, and the Z direction is the vertical direction. The X direction is an example of a first direction, and the Y direction is an example of a second direction. The θ direction is the rotation direction around the Z direction. In addition, the workpiece W includes a base material layer 20, an intermediate layer 21, and a surface film 22 in order from the Xθ stage 14 side (see FIG. 2).

  The liquid supply means 16 supplies pressurized liquid into a processing head 60 (liquid chamber 66) described later. There is no restriction | limiting in particular as the liquid supply means 16, A well-known means, a well-known apparatus, etc. can be used. For example, pure water stored in a tank may be supplied by a high pressure pump.

  The machining unit 30 is disposed above the Xθ stage 14 and is configured to be movable in the Y direction and the Z direction by a machining unit drive mechanism (not shown). The machining unit drive mechanism is controlled based on a control signal output from the control unit 72.

  The processing unit 30 is configured by a hybrid method that uses both a direct condensing method and a liquid jet method. According to this configuration, as will be described in detail later, it is possible to enjoy the respective merits of the direct condensing method and the liquid jet method and improve the processing quality.

  The processing unit 30 includes a light amount adjusting unit 32, a polarization adjusting unit 34, a polarization beam splitter 36, a dichroic mirror 38, a branching and focusing unit 40, a mirror 42, a beam shape shaping unit 44, and a processing head 60. It has. In the present embodiment, the laser light source 12 and the AF device 70 are provided in the processing unit 30. However, the laser light source 12 and the AF device 70 may be provided separately from the processing unit 30.

  The processing laser light L1 emitted from the laser light source 12 sequentially passes through the light amount adjusting unit 32 and the polarization adjusting unit 34 and enters the polarizing beam splitter 36.

  The light amount adjusting means 32 is disposed on the emission side of the laser light source 12 and adjusts the light amount of the processing laser light L1 emitted from the laser light source 12. As the light amount adjusting means 32, for example, an aperture in which the size of the light passage range is variable, a combination of a half-wave plate (λ / 2 plate) and a polarizing element, or a variable ND filter having different light transmission efficiency, etc. It can be set as the structure using.

  The polarization adjusting unit 34 adjusts the polarization direction of the processing laser beam L1, and is composed of, for example, a half-wave plate.

  The polarization beam splitter 36 splits the incident processing laser light L1 with a deflection separation surface (joint surface) 36a. As a result, the processing laser light L1 incident on the polarization beam splitter 36 includes the first processing light L1s (S-polarized light) reflected by the polarization separation surface 36a and the second processing light (P-polarized light) transmitted through the polarization separation surface 36a. The light is branched to L1p (light branching step). The polarization beam splitter 36 is an example of an optical branching unit. The first processing light L1s is an example of the first laser light, and the second processing light L1p is an example of the second laser light.

  The first processed light L1s emitted from the polarization beam splitter 36 passes through the dichroic mirror 38 and enters the branching and condensing means 40.

  The dichroic mirror 38 transmits light in the first wavelength range and reflects light in a second wavelength range different from the first wavelength range. In this example, the first wavelength region includes the wavelength (less than 400 nm) of the processing laser light L1 emitted from the laser light source 12, and the second wavelength region is the wavelength (400 nm or more) of the AF light L2 emitted from the AF device 70. )including. Thus, the first processed light L1s emitted from the polarization beam splitter 36 passes through the dichroic mirror 38 and enters the branching and condensing means 40. Then, the first processing light L1s is condensed by the branching and condensing means 40 and irradiated onto the workpiece W. Further, the AF light L2 emitted from the AF device 70 is reflected by the dichroic mirror 38, condensed by the branching and condensing means 40, irradiated to the workpiece W, and reflected by the workpiece W. The reflected light of L2 is returned to the AF device 70 via the reverse path and detected.

  The branching and condensing means 40 is configured to include, for example, a diffraction grating and a lens, and condenses the incident first processing light L1s at a predetermined height position (Z direction position), and a plurality of condensing points. Branch. That is, the branch condensing means 40 branches and condenses the first processing light L1s. In the present embodiment, as will be described later, the branching and condensing unit 40 branches and condenses the first processed light L1s at two condensing points P1 and P2 (see FIG. 2). The number of condensing points to be branched and condensed may be three or more. The branch condensing means 40 is an example of a direct condensing means.

  The branch condensing means 40 is configured to be rotatable in the θ direction and movable in the Z direction with respect to the optical axis by a rotational movement mechanism (not shown). The rotational movement mechanism is controlled based on a control signal output from the control unit 72 and drives the branch condensing means 40 to rotate in the θ direction or to move in the Z direction (vertical direction). As a result, as will be described later, it becomes possible to move the branch condensing means 40 in the Z direction in accordance with a change in the relative distance between the workpiece W and the machining unit 30, and thereby the workpiece W and the workpiece are processed. It becomes possible to keep the relative distance to the unit 30 constant. Further, by rotating the branch condensing means 40 in the θ direction, the branch concentrating means 40 is divided according to the processing width (width in the Y direction) of the processing target region R (see FIG. 2) along the X direction of the workpiece W. It is possible to adjust the distance (distance in the Y direction) between the two condensing points P1 and P2 branched and condensed by the light means 40.

  On the other hand, the second processing light L1p emitted from the polarization beam splitter 36 is reflected by the mirror 42, shaped into a desired beam shape by the beam shape shaping means 44, and then incident on the machining head 60.

  The beam shape shaping unit 44 includes, for example, an aperture (rectangular aperture, circular aperture), an axicon lens, a beam homogenizer, a diffraction grating, a lens, and the like, and the beam shape, size, intensity distribution, and the like of the second processing light L1p, Shape the beam angle etc.

  The processing head 60 ejects the pressurized liquid supplied from the liquid supply means 16 by the liquid jet J, and uses the liquid jet J as a waveguide to apply the second processing light L1p to the processing scheduled region of the workpiece W. Irradiate R. The specific configuration of the machining head 60 is as follows.

  The processing head 60 includes a condenser lens 62, a transmission glass 64, a liquid chamber 66, and a liquid jet injection nozzle 68.

  The condensing lens 62 condenses the second processing light L1p incident on the processing head 60 to the orifice (nozzle hole) of the liquid jet injection nozzle 68.

  The transmission glass 64 is disposed between the condenser lens 62 and the liquid chamber 66 and is configured as a partition wall that seals the pressurized liquid supplied from the liquid supply unit 16 inside the liquid chamber 66. The transmissive glass 64 is formed of a light transmissive member (for example, quartz glass) that transmits the second processing light L1p. Thereby, the second processing light L1p emitted from the condenser lens 62 is transmitted through the transmission glass 64 and guided to the inside of the liquid chamber 66.

  The liquid chamber 66 is a liquid container for sealing the pressurized liquid supplied from the liquid supply means 16, and the wall surface on the incident surface side (upper surface side in FIG. 1) of the second processing light L1p is formed by the transmission glass 64 described above. It is configured.

  The liquid jet nozzle 68 is disposed at a position facing the workpiece W in the processing head 60 and communicates with the liquid chamber 66. Thereby, the pressurized liquid stored in the liquid chamber 66 is ejected from the liquid jet ejection nozzle 68 toward the workpiece W as the liquid jet J. Further, since the second processing light L1p is condensed on the orifice of the liquid jet injection nozzle 68 through the condenser lens 62 and the transmission glass 64, the second processing light is injected into the liquid jet J injected from the liquid jet injection nozzle 68. L1p is guided. As a result, the second processing light L1p is guided by the liquid jet J and applied to the workpiece W.

  Although details are omitted, it is known that processing performance is improved by supplying a gas fluid so as to include the liquid jet J (see Japanese Patent No. 54337578).

  The AF device 70 includes an autofocus light source (AF light source) (not shown) that emits light in a wavelength region (second wavelength region) different from the processing laser light L1 as AF light. In the present embodiment, light having a wavelength of 400 nm or more is used as AF light. The AF light L2 emitted from the AF light source is reflected by the dichroic mirror 38, condensed by the branching and condensing means 40, and irradiated onto the workpiece W. Then, the reflected light of the AF light L2 from the workpiece W enters the AF device 70 via the reverse path. The AF apparatus 70 detects the reflected light of the AF light L2 from the workpiece W with a photodetector having a plurality of light receiving elements, and sets the relative distance (height) between the workpiece W and the machining unit 30. A corresponding detection signal (autofocus signal) is output to the control unit 72. Since the configuration of such an AF device 70 is well known, detailed description thereof is omitted.

  The control unit 72 includes a CPU, a memory, an input / output circuit unit, various control circuit units, and the like, and controls the operation of each unit of the laser processing apparatus 10. That is, the control unit 72 performs various controls of the laser processing apparatus itself such as light emission control of the laser light source 12, movement control of the Xθ stage 14 and the processing unit 30, liquid supply control of the liquid supply means 16, and the like.

  Further, the control unit 72 performs condensing point control (focus control) of the branch condensing unit 40. Specifically, based on the detection signal output from the AF device 70, the control unit 72 sets the branch condensing unit 40 so that the relative distance (height) between the workpiece W and the processing unit 30 is constant. Controls the rotational movement mechanism. Further, the control unit 72 determines the two condensing points P1 and P2 branched and condensed by the branching and condensing means 40 based on the processing conditions (including the processing width of the planned processing region) input from an input unit (not shown). The branch condensing unit 40 is rotated in the θ direction by controlling the rotational movement mechanism of the branch condensing unit 40 so that the interval (distance in the Y direction) becomes an interval corresponding to the processing width of the planned processing region R.

  With the above configuration, in the laser processing method using the laser processing apparatus 10 of the first embodiment, the workpiece W is processed by the direct condensing method using the first processing light L1s (direct condensing method processing). ) Is performed, processing using the liquid jet method (liquid jet processing) is performed using the second processing light L1p.

  FIG. 2 is a schematic view showing a state when the workpiece W is irradiated with the first machining light L1s in the direct condensing method machining in the first embodiment. It is assumed that the planned processing region R of the workpiece W is formed along the X direction.

  As shown in FIG. 2, in the direct condensing method processing in the first embodiment, the first processing light L1s incident on the branch condensing means 40 while processing and feeding the workpiece W in the X direction by the Xθ stage 14. Is branched and condensed at two condensing points P1 and P2 different from each other on the surface of the workpiece W by the branching and condensing means 40. Specifically, the two condensing points P <b> 1 and P <b> 2 are branched and condensed on the outer edge portions on both sides in the Y direction in the planned processing region R of the workpiece W by the branching and condensing means 40. As a result, cuts 24a and 24b having a predetermined depth are formed in the surface film 22 on the outer edge portions on both sides of the planned processing region R. In addition, the light quantity of the 1st process light L1s shall be adjusted by the light quantity adjustment means 32 so that it may become a desired light quantity (light quantity which can remove only the surface film 22).

  FIG. 3 is a diagram for explaining the effect when the branch condensing means 40 is rotated in the θ direction.

  When the branch condensing means 40 is rotated in the θ direction, as shown in FIG. 3, two condensing points of the first processed light L1s that are branched and condensed by the branch condensing means 40 (not shown in FIG. 3). The positional relationship between P1 and P2 changes. Accordingly, the interval (width) M in the Y direction between the two condensing points P1 and P2 changes. As shown in FIG. 3A, the condition in which the interval M in the Y direction is relatively wide, as shown in FIG. As shown in b), a condition where the interval M in the Y direction is relatively narrow can be created.

  In the direct condensing method processing in the first embodiment, the interval M in the Y direction between the two condensing points P1 and P2 is set to the processing width of the processing region R by rotating the branch condensing unit 40 in the θ direction. It is possible to adjust accordingly. Thereby, even when the processing widths of the planned processing regions R are different, the branch condensing means 40 is rotated in the θ direction to change the interval M in the Y direction between the two condensing points P1 and P2, thereby obtaining the result shown in FIG. As shown, it is possible to form notches 24a and 24b having a predetermined depth in the surface film 22 on the outer edge portions on both sides of the planned processing region R.

  FIG. 4 is a schematic diagram illustrating a state in which the liquid jet J is ejected onto the workpiece W in the liquid jet processing in the first embodiment. FIG. 5 is a schematic diagram illustrating a state after the workpiece W is processed by the second processing light L1p induced by the liquid jet J.

  As shown in FIG. 4, the liquid jet processing in the first embodiment is performed after the direct condensing processing described above is performed. That is, after forming notches 24a and 24b having a predetermined depth in the surface film 22 on the outer edge portions on both sides of the planned processing region R by direct condensing method processing, the workpiece W is processed and fed in the X direction by the Xθ stage 14. However, the liquid jet J is ejected from the processing head 60 toward the inner region sandwiched between the outer edge portions on both sides of the processing scheduled region R. Accordingly, the second processing light L1p induced by the liquid jet J is irradiated to the inner region of the processing scheduled region R. As a result, as shown in FIG. 5, the surface film 22 and the intermediate layer 21 in the inner region of the planned processing region R are removed, and the workpiece W has a predetermined depth (base material layer 20) along the planned processing region R. The depth of the processed groove 26 is formed.

  FIG. 6 is a diagram for explaining the effect of the laser processing method according to the first embodiment, and is a diagram showing a processing result when the direct condensing method processing and the liquid jet processing are combined. Here, in order to explain the effects of the laser processing method in the first embodiment in an easy-to-understand manner, a single condensing lens is used in place of the branch condensing means 40, and outer edge portions on both sides of the processing scheduled region R are used. A case in which the first processing light L1s is condensed only on one outer edge portion and the direct condensing method processing is performed will be described.

  As shown in FIG. 6A, after forming a notch 24a having a predetermined depth in the surface film 22 by direct condensing method processing only on one of the outer edges on both sides of the planned processing region R, When the liquid jet processing is performed on the inner region of the processing region R, a processing result as shown in FIG. 6B is obtained. That is, the side where the cut 24a is formed (the side with the edge cut) is edge-cut by the cut 24a, so that the film peeling outside the processing region R is blocked, but the opposite side (the side without the edge cut) ), There is no cut as described above, and the edge is not cut, so that peeling of the film on the outside of the planned processing region R is greatly spread.

  As can be seen from the processing results shown in FIG. 6, after forming notches 24 a and 24 b of a predetermined depth in the surface film 22 by direct condensing method processing on the outer edge portions on both sides of the processing region R, liquid jet processing Thus, by processing the inner region of the processing scheduled region R, it becomes possible to effectively suppress the influence of film peeling, debris, and heat generated by laser processing and improve the processing quality.

  FIG. 7 is a flowchart showing a laser processing method using the laser processing apparatus 10 of the first embodiment. Unless otherwise specified, each process is executed under the control of the control unit 72.

  First, before starting the processing of the workpiece W, an adjustment process for direct condensing method processing for performing direct condensing method processing is performed in the laser processing apparatus 10 (step S10). Here, it is assumed that the operation mode of the laser processing apparatus 10 is set to direct condensing method processing.

  In the adjustment step for the direct condensing method processing, the laser light source is operated by operating the light amount adjusting means 32 so that the first processing light L1s and the second processing light L1p polarized and separated by the polarization beam splitter 36 each have a desired light amount. 12 adjusts the amount of the processing laser beam L1 emitted from the laser beam 12 and operates the polarization adjusting unit 34 to adjust the polarization direction of the processing laser beam L1.

  Further, the interval M in the Y direction between the two condensing points P1 and P2 of the first processing light L1s collected by the branching and condensing means 40 is adjusted so as to correspond to the processing width of the processing region R. . For example, the control unit 72 determines that the interval M in the Y direction between the two condensing points P1 and P2 is the processing width of the processing planned region R based on the processing width of the processing planned region R input via an input unit (not shown). You may make it rotate the branch condensing means 40 to the (theta) direction with a rotational movement mechanism so that it may become a corresponding space | interval. Further, the branch condensing means 40 is manually rotated in the θ direction so that the interval M in the Y direction between the two condensing points P1 and P2 is adjusted so as to correspond to the processing width of the processing region R. It may be. Thereby, the interval M in the Y direction between the two condensing points P1 and P2 is set to an interval corresponding to the processing width of the processing scheduled region R.

  Next, the alignment process which performs relative position alignment of the to-be-processed object W and the processing unit 30 mounted on the X (theta) stage 14 with the alignment apparatus which is not shown in figure (step S12) is performed.

  Next, after the processing unit 30 is moved to a predetermined height position (Z-direction position) with respect to the workpiece W, the branch condensing means 40 of the processing unit 30 is opposed to the processing scheduled region R to be processed. Thus, the processing unit 30 is indexed and fed in the Y direction (step S14).

  Next, a direct condensing method machining process using the first machining light L1s is performed on the workpiece W while feeding the Xθ stage 14 in the X direction (step S16). The direct condensing method processing step is an example of a first laser processing step.

  In the direct condensing method processing step, the first processing light L1s reflected by the polarization separation surface 36a of the polarization beam splitter 36 enters the branch condensing means 40 via the dichroic mirror 38. Then, the first processing light L1s is condensed by the branching and condensing means 40 on two condensing points P1 and P2 that are different from each other in the Y direction on the surface of the workpiece W (branch condensing step). As a result, cuts 24a and 24b having a predetermined depth are formed in the surface film 22 on the outer edge portions on both sides of the planned processing region R. Thus, before the liquid jet processing is performed, the edge film processing is performed on the outer peripheral surface film 22 on both sides of the processing region R by the direct condensing method processing, which is a disadvantage in the liquid jet processing. It is possible to effectively suppress film peeling.

  In the present embodiment, the first processing light L1s is simultaneously condensed at two condensing points P1 and P2 that are different from each other in the Y direction by the branching and condensing means 40. Since it can process by (one process feed), processing efficiency can be improved.

  Further, in the present embodiment, at the same time as direct condensing method processing is performed, control is performed by the AF device 70 and the control unit 72 so that the relative distance between the processing unit 30 and the workpiece W is constant. . That is, the AF device 70 detects the reflected light of the AF light L2 irradiated to the workpiece W via the dichroic mirror 38 and the branching and focusing means 40, and the relative distance between the processing unit 30 and the workpiece W is detected. A detection signal corresponding to the signal is output to the control unit 72. The control unit 72 performs feedback control of the rotational movement mechanism of the branching and focusing unit 40 so that the relative distance between the processing unit 30 and the workpiece W is constant. Thereby, since the relative distance between the machining unit 30 and the workpiece W is constant, the first machining light L1s is constant without being affected by the change in the relative distance between the machining unit 30 and the workpiece W. Since the condensing state is maintained, high-precision and high-quality processing is possible in the direct condensing method.

  When the direct condensing method processing for one processing planned region R is finished in this way, a determination step is performed to determine whether processing of all the processing scheduled regions R has been completed (step S18).

  If it is determined in step S18 that the machining of all scheduled machining areas R has not been completed, the machining unit 30 is indexed and fed in the Y direction by an index feed amount corresponding to the interval between the scheduled machining areas R. (Step S14), with the branching and condensing means 40 of the processing unit 30 positioned at a position facing the adjacent processing scheduled region R, direct condensing processing is performed while the Xθ stage 14 is processed and fed in the X direction. Performed (step S16). In this way, when the indexing feed in the Y direction and the machining feed in the X direction are alternately repeated, and the direct focusing method machining is performed on all the machining scheduled regions R parallel to the X direction, the Xθ stage 14 is moved. The condensing method processing is also performed in the same manner on the planned processing region R that is rotated 90 ° in the θ direction and orthogonal to the previous processing planned region R.

  On the other hand, when it is determined in the determination step of step S18 that the processing of all the planned processing regions R has been completed, the operation mode of the laser processing apparatus 10 is changed from the direct focusing method processing to the liquid jet processing. (Step S20).

  Next, after the processing unit 30 is moved to a predetermined height position (Z-direction position) with respect to the workpiece W, the processing head 60 (liquid jet spray nozzle 68) of the processing unit 30 is the processing target region R to be processed. The processing unit 30 is indexed and fed in the Y direction so as to face the position (step S22).

  Next, a liquid jet processing process using the second processing light L1p is performed on the workpiece W while processing and feeding the Xθ stage 14 in the X direction (step S24). The liquid jet processing step is an example of a second laser processing step.

  In the liquid jet processing step, the pressurized liquid in the liquid chamber 66 supplied from the liquid supply means 16 is ejected as a liquid jet J from the liquid jet ejection nozzle 68. Further, the second processing light L1p transmitted through the polarization separation surface 36a of the polarization beam splitter 36 enters the processing head 60 through the mirror 42 and the beam shape shaping means 44. The second processing light L1p incident on the processing head 60 enters the orifice of the liquid jet injection nozzle 68 via the condenser lens 62, the transmission lens 6b, and the liquid chamber 66. As a result, the second processing light L1p is guided to the liquid jet injection nozzle 68, and is guided to the workpiece W while repeating total reflection in the liquid jet J using the liquid jet J as a waveguide. Irradiation is performed on the inner region of the processing scheduled region R of the object W. As a result, as shown in FIG. 5, the surface film 22 and the intermediate layer 21 in the inner region of the processing planned region R are removed, and the workpiece W has a predetermined depth (base material layer) along the processing target region R. A processing groove 26 having a depth of up to 20 is formed.

  In this way, when the liquid jet system machining for one scheduled machining area R is completed, a determination process for determining whether or not machining for all the scheduled machining areas R is completed is performed (step S26).

  If it is determined in step S26 that the machining of all the planned machining areas R has not been completed, the machining unit 30 is indexed and fed in the Y direction by an index feed amount corresponding to the interval of the machining planned areas R. (Step S22), with the processing head 60 (liquid jet injection nozzle 68) of the processing unit 30 positioned at a position facing the adjacent processing scheduled region R, the liquid is transferred while processing the Xθ stage 14 in the X direction. Jet processing is performed (step S24). In this way, the index feed in the Y direction and the machining feed in the X direction are alternately repeated, and after the liquid jet system machining is performed on all the machining scheduled regions R parallel to the X direction, the Xθ stage 14 is moved. The liquid jet system machining is performed in the same manner on the planned machining area R that is rotated by 90 ° in the θ direction and orthogonal to the previous machining planned area R.

  On the other hand, when it is determined in the determination step of step S26 that the processing of all the planned processing regions R has been completed, this flowchart ends.

  Next, the effect of the first embodiment will be described.

  According to the first embodiment, the outer edge portions on both sides of the planned processing region R are processed by the direct condensing method, and then the inner region sandwiched between the outer edge portions on both sides of the processing planned region R is processed by the liquid jet method. To do. As a result, it is possible to effectively suppress the influence of film peeling, debris, and heat caused by laser processing and improve the processing quality.

  In the first embodiment, the processing laser light L1 emitted from the laser light source 12 is branched into the first processing light L1s and the second processing light L1p by the deflection beam splitter 36, and is directly collected by the first processing light L1s. The optical system processing and the liquid jet system processing by the second processing light L1p are realized by one apparatus. Therefore, it is possible to reduce the size and cost of the apparatus, and if alignment is performed only once in the direct condensing method processing, the alignment can be omitted in the subsequent liquid jet processing, thereby improving the overall throughput. Can be made.

  In the first embodiment, since the first processing light L1s is branched and condensed at the two condensing points P1 and P2 by the branching and condensing means 40, the edge portions on both sides of the processing scheduled region R are set to one. Processing can be performed with a pass, and processing efficiency can be improved.

  Further, in the first embodiment, the branch condensing unit 40 is configured to be rotatable in the θ direction (rotation direction around the optical axis), and two condensing points P1 branched and condensed by the branch condensing unit 40, The interval M in the Y direction of P2 can be adjusted to be an interval corresponding to the processing width of the planned processing region R. Thereby, it is possible to process an arbitrary scheduled processing region R in one pass without being affected by the processing width of the processing planned region R, and it is possible to increase the processing freedom as well as the processing efficiency.

  In the first embodiment, since the relative distance between the processing unit 30 and the workpiece W is controlled to be constant by the AF device 70 and the control unit 72, the processing quality is kept constant in the processing region. be able to.

(Second Embodiment)
Next, a second embodiment will be described.

  FIG. 8 is a schematic view showing a laser processing apparatus 10A according to the second embodiment. In FIG. 8, components that are the same as or similar to those in FIG.

  In the first embodiment, the first processing light L1s is branched and condensed at two different focusing points P1 and P2 by the branching and focusing means 40, whereas in the second embodiment, the branching and focusing is performed. Instead of the means 40, a single condenser lens 46 is provided.

  The laser processing apparatus 10A of the second embodiment is basically the same as that of the first embodiment except that a condensing lens 46 is provided instead of the branch condensing means 40.

  As shown in FIG. 8, the condenser lens 46 in the second embodiment is configured to be movable in the Z direction by a moving mechanism (not shown). The moving mechanism is controlled based on a control signal output from the control unit 72 and drives the condenser lens 46 so as to move in the Z direction (vertical direction). Thus, as in the first embodiment, the AF device 70 and the control unit 72 perform control so that the relative distance between the processing unit 30 and the workpiece W is constant.

  Moreover, the condensing lens 46 in 2nd Embodiment condenses the 1st process light L1s on one condensing point. Therefore, in the laser processing method using the laser processing apparatus 10 </ b> A of the second embodiment, when the direct focusing method processing is performed on the processing target region R, one of the outer edge portions on both sides of the processing target region R. After the condensing point of the condensing lens 46 is aligned with the outer edge portion to form the cut 24a, the condensing point of the condensing lens 46 needs to be aligned with the other outer edge portion to form the notch 24b.

  That is, in the second embodiment, in order to form the cuts 24a and 24b at the outer edge portions on both sides of the planned processing region R by direct condensing method processing, two passes instead of one pass are required. . However, also in the second embodiment, the notches 24a and 24b are formed in the outer edge portions on both sides of the planned processing region R by direct condensing method processing, and then the inner region of the processing planned region R is formed by liquid jet processing. Since the processing is performed, as in the first embodiment, it is possible to effectively suppress the influence of film peeling, debris, and heat caused by laser processing, and to improve the processing quality.

(Third embodiment)
Next, a third embodiment will be described.

  FIG. 9 is a schematic view showing a laser processing apparatus 10B of the third embodiment. In FIG. 9, components that are the same as or similar to those in FIG. 8 are given the same reference numerals, and descriptions thereof are omitted.

  The third embodiment further includes an AOD (acousto-optic element) 48 disposed between the polarization beam splitter 36 and the dichroic mirror 38 in addition to the configuration of the second embodiment.

  The AOD 48 deflects the incident first processing light L1s at a specific angle and a specific frequency. Since the AOD 48 can change the emission angle of light by modulating the input acoustic frequency, the first processing light L1s can be spatially moved and scanned at high speed. That is, the AOD 48 can deflect the first processing light L1s so that the first processing light L1s alternately scans the outer edge portions on both sides of the processing scheduled region R at a timing shifted in time. The AOD 48 is an example of a light deflecting unit.

  In the laser processing method using the laser processing apparatus 10B of the third embodiment, when the direct focusing method processing is performed on the processing target region R, the workpiece W is processed and fed in the X direction by the Xθ stage 14. However, while the AOD 48 scans the first processing light L1s at a specific frequency at a small angle in the Y direction at high speed, the condensing lens 46 leaves an interval corresponding to the scanning angle (the aforementioned minute angle) (Y direction). The first machining light L1s is condensed on the surface of the workpiece W (light deflection step). As a result, processing by the direct condensing method is performed while the condensing points of the first processing light L1s condensed by the condensing lens 46 alternately move at high speeds on the outer edge portions on both sides of the processing scheduled region R.

  Therefore, according to the third embodiment, the first focusing light L1s is spatially moved by the AOD 48, and the direct focusing process is performed while scanning at high speed. It is possible to perform direct condensing method processing on the outer edge portion, and the same effect as in the first embodiment can be obtained.

  In the third embodiment, the configuration including the AOD 48 is shown as an example of the light deflecting unit. However, the configuration is not limited to this. For example, an optical scanning unit such as a galvano scanner or a polygon scanner, or another optical element is used. It is good also as a structure.

(Fourth embodiment)
Next, a fourth embodiment will be described.

  FIG. 10 is a schematic view showing a laser processing apparatus 10C according to the fourth embodiment. In FIG. 10, the same or similar components as those in FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted.

  In addition to the second embodiment, the fourth embodiment further includes a spatial light modulator 50 and a plurality of mirrors 52A to 52C.

  As the spatial light modulator 50, for example, a reflective liquid crystal (LCOS) spatial light modulator (SLM) is used. The operation of the spatial light modulator 50 and the hologram pattern presented by the spatial light modulator 50 are controlled by the control unit 72. Note that a specific configuration of the spatial light modulator 50 and a hologram pattern presented by the spatial light modulator 50 are already known, and thus detailed description thereof is omitted here.

  The controller 72 controls the operation of the spatial light modulator 50 and causes the spatial light modulator 50 to present a predetermined hologram pattern. Specifically, the first processing light L1s is condensed on two different condensing points P1 and P2 (see FIG. 2) by the condensing lens 46 on the surface of the workpiece W. A hologram pattern for modulating the light L1s is presented to the spatial light modulator 50. The hologram pattern is derived in advance based on the wavelength of the first processing light L1s, the condensing lens 46, and the like, and is stored in the control unit 72.

  With this configuration, the first processing light L1s incident on the spatial light modulator 50 is modulated according to a predetermined hologram pattern presented on the spatial light modulator 50. At that time, the control unit 72 causes the first processing light L1s to be condensed on two condensing points P1 and P2 different from each other by the condensing lens 46 on the surface of the workpiece W. Control for causing the spatial light modulator 50 to present a hologram pattern for modulation is performed.

  The first processed light L1s emitted from the spatial light modulator 50 is sequentially reflected by the mirrors 52A to 52C, then passes through the dichroic mirror 38 and is incident on the condenser lens 46. Then, the first processing light L1s incident on the condensing lens 46 is two condensing points P1 and P2 that are different from each other by the condensing lens 46 on the surface of the workpiece W by the condensing lens 46. It is condensed to.

  In the laser processing method using the laser processing apparatus 10 </ b> C of the fourth embodiment, two condensing points where the first processing light L <b> 1 s is different from each other by the condensing lens 46 on the surface of the workpiece W by the spatial light modulator 50. Since the light is focused on P1 and P2, it is possible to perform direct light focusing processing on the outer edge portions on both sides of the processing target region R in one pass, and the same effect as in the first embodiment can be obtained. .

  In each of the above-described embodiments, the configuration in which the workpiece W can be moved in the X direction and can be rotated in the θ direction by the Xθ stage 14 and the processing unit 30 can be moved in the Y direction and the Z direction has been described. As long as the workpiece W and the processing unit 30 are configured to be relatively movable or rotatable in the X direction, the Y direction, the Z direction, and the θ direction, other aspects different from the present embodiment may be appropriately used. Can be adopted.

  Moreover, although each embodiment mentioned above showed the structure which implement | achieved the direct condensing type | mold process and the liquid jet system process with one apparatus, these processes may be implement | achieved with another apparatus.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the scope of the present invention. .

  DESCRIPTION OF SYMBOLS 10 ... Laser processing apparatus, 12 ... Laser light source, 14 ... X (theta) stage, 16 ... Liquid supply means, 20 ... Base material layer, 21 ... Intermediate | middle layer, 22 ... Surface film, 24a, 24b ... Notch, 26 ... Process groove, 30 ... Processing unit, 32 ... Light quantity adjusting means, 34 ... Polarization adjusting means, 36 ... Polarized beam splitter, 38 ... Dichroic mirror, 40 ... Branch condensing means, 42 ... Mirror, 44 ... Beam shape shaping means, 46 ... Condensing lens 48 ... AOD, 50 ... Spatial light modulator, 52 ... Mirror, 60 ... Processing head, 62 ... Condensing lens, 64 ... Transmission glass, 66 ... Liquid chamber, 68 ... Liquid jet injection nozzle, 70 ... AF device, 72 ... Control part, L1 ... Processing laser light, L1s ... First processing light, L1p ... Second processing light, L2 ... AF light, J ... Liquid jet

Claims (13)

Laser processing comprising: a laser light source that emits a processing laser beam; a processing unit that laser-processes a workpiece using the processing laser beam; and a moving unit that relatively moves the processing unit and the workpiece. A device,
The processing unit is
Light branching means for branching the processing laser light emitted from the laser light source into a first laser light and a second laser light;
A second direction orthogonal to the first direction in the planned processing area along the first direction with respect to the workpiece that moves relative to the processing unit in the first direction by the moving means. Direct condensing means for condensing the first laser light on outer edge portions on both sides of
A pressurized liquid is ejected by a liquid jet to the workpiece that moves relative to the machining unit in the first direction by the moving means, and the liquid jet is used as a waveguide. A processing head that irradiates the inner region sandwiched between the outer edge portions on both sides of the processing scheduled region,
A laser processing apparatus comprising: The direct condensing means includes branch condensing means for branching and condensing the first laser light at outer edge portions on both sides of the processing planned area.
The laser processing apparatus according to claim 1. The branching and condensing means can adjust the distance in the second direction of the two condensing points of the first laser beam branched and condensed according to the width in the second direction of the planned processing region. Composed of,
The laser processing apparatus according to claim 2. The branch condensing means comprises a spatial light modulator.
The laser processing apparatus according to claim 2. The direct condensing means deflects the first laser light so that the first laser light alternately scans the outer edge portions on both sides of the processing scheduled area at a timing shifted in time. Having means,
The laser processing apparatus according to claim 1. The light deflection means comprises an acousto-optic element;
The laser processing apparatus according to claim 5. Outer edges on both sides of the second direction orthogonal to the first direction in the planned processing area along the first direction with respect to the workpiece that moves relative to the direct light collecting means in the first direction. A first laser processing step of condensing the first laser light on the part by the direct condensing means,
A second laser that ejects pressurized liquid from the processing head by a liquid jet to the workpiece that moves relative to the processing head in the first direction, and uses the liquid jet as a waveguide. A second laser processing step of irradiating the inner region sandwiched between the outer edge portions on both sides of the processing scheduled region;
A laser processing method comprising: A light branching step of branching the processing laser light emitted from the laser light source into the first laser light and the second laser light;
The laser processing method according to claim 7. The first laser processing step includes a branching and condensing step of branching and condensing the first laser light at outer edge portions on both sides of the processing planned region.
The laser processing method according to claim 8. In the branching and condensing step, the distance in the second direction between the two condensing points of the first laser beam branched and condensed is adjusted according to the width in the second direction of the planned processing region. Having an adjustment step,
The laser processing method according to claim 9. The branching and condensing step branches and condenses the first laser light using a spatial light modulator.
The laser processing method according to claim 9. In the first laser processing step, the first laser light is deflected so that the first laser light alternately scans the outer edge portions on both sides of the processing scheduled region at a timing shifted in time. Having a light deflection step,
The laser processing method according to claim 7. The light deflection step deflects the first laser beam using an acousto-optic element.
The laser processing method according to claim 12.