Laser Focusing control method in material processingInvention field
The present invention relates to the Laser Focusing in the Laser Processing of material, more particularly to a kind of processing of materialControl method.
Background technology
Using cold laser, such as do not produce thermal effect when processing such as fragile material using ultrashort pulse laserShould, there is no heat affected area (HAZ).Ultrashort pulse laser material is processed has two ways with treatment：Material modification and material ablation (ablation).Material modification is refraction after material local absorption femtosecond laserRate is changed, and retrofit is realized using mechanism such as two-photon polymerized and photochemical reactions.Material disappearsIt is that cold laser ablation target produces HTHP plasma to melt (ablation).Plasma formed whenBetween less than incident pulse energy to be transferred to time of periphery material, therefore thermal diffusion effect will not be caused.Absorbed using the Multi-photon Nonlinear in micro Process region and ionization can be realized without heat transfer to any materialMicrofabrication.
The laser technology of fragile material cutting is using ultrashort pulse laser in fragile material such as glass and indigo plantThe cutting path of required defect array definition is produced in diamond material, then using in fragile materialStress is voluntarily discharged along cutting path or is propagated along cutting path using the crack that extraneous method is produced and producedThe separation or division of raw fragile material.Fragile material cutting can also directly using laser ablation come or swashLight realizes the cutting of fragile material into silk.
Prior art is produced in fragile material such as glass and sapphire material using ultrashort pulse laserThe cutting path of raw required defect array definition, or directly using laser ablation come or laser intoSilk realizes the cutting of fragile material, and such cutting speed is all slow.
For example, Fig. 1 a show a laser-processing system for typical prior art.Laser 11 is producedRaw LASER Light Source is by optics module 12 and including the focusing including condenser lens or scanning focused galvanometerOptical element 13 is focused on workpiece 14.Fig. 1 b show the optics of the Laser Processing of prior artFocused view, as shown in Figure 1 b, the size of conventional focal beam spot 15 is by focusing optic 13, incidenceThe size and wavelength of light source are together decided on.Common focusing optic 13 includes condenser lens, focuses onLens group and scanning focused galvanometer.The beam waist radius of the common focal beam spot for laser machiningGenerally several microns to hundreds of microns, depending on concrete application and light path design.Therefore, no matterBe produced in the fragile material such as glass and sapphire material using ultrashort pulse laser required by it is scarceBreak through enemy lines the cutting path of row definition, or directly using laser ablation come or laser filament realize fragilityThe cutting of material, cutting speed is all slow.Because in defect array generating region, or swashLight is melted or laser filament region, it is necessary to which the high intensity laser beam produced using high NA focus mirror is gatheredBurnt hot spot is reaching defect, ablation or critical intensity required by silk.For a certain size focusingHot spot, the focusing of high-NA is limited along the depth of focus of direction of beam propagation.Depth of focus and beam waistSize directly determine defect, ablation or into the size of silk.Therefore, focus lamp and/or fragile materialMust move repeatedly or scan along direction of beam propagation, so as to (separate or divide in direction of beam propagationBroken face direction) form defect array, laser ablation or the laser filament for repeating.It is larger for thicknessThe cutting of fragile material, the number of times for moving repeatedly or scanning is more, and such method causes fragile materialThe operating time of cutting becomes very long.For spherical surface focusing mirror, beam waist is with aspherical commonThe increase of burnt parameter and increase.This surface for any spherical surface focusing mirror, for limited light beamWith a tight waist, depth of focus has basic limitation.
The content of the invention
It is an object of the invention to provide the Laser Focusing control method in a kind of processing of material.
According to an aspect of the present invention, there is provided the Laser Focusing control method in a kind of material processing, bagInclude：
One diffraction optical element and focusing optic are combined, the combination can increase materialEffective depth of focus of processing, without focus spot size and beam waist required by sacrifice；
Make laser beam incident from the diffraction optical element, after being focused on through the focusing optic, shinePenetrate on workpiece；
Make the laser beam that hot spot or focusing surface with effective depth of focus are formed on the workpiece.
Method as described above, wherein, the diffraction optical element is many focal length diffraction optical elements of radial direction,Methods described includes：
The many focal length diffraction optical elements of the radial direction are combined with the focusing optic；
Make laser beam incident from many focal length diffraction optical elements of the radial direction, through the focusing opticAfter focusing, it is radiated on workpiece；
Make the laser beam that radially many focal length focal beam spots are formed on the workpiece.
Method as described above, wherein, further by horizontal many focal length diffraction optical elements and the footpathCombined to many focal length diffraction optical elements, the laser beam is formed on the workpieceLaterally with radially many focal length spot arrays.
Method as described above, wherein, further by transverse focusing extension diffraction optical element with it is describedRadially many focal length diffraction optical elements are combined, and make laser beam shape on the workpieceFocusing extension is open into radially many focal length spot arrays.
Method as described above, wherein, it is further that a radial direction dispersive optical elements are multifocal with the radial directionCombined away from diffraction optical element, the laser beam is formed on the workpiece radially poly-Jiao's extension spot array.
Method as described above, wherein, it is further that a radial direction dispersive optical elements are multifocal with the radial directionCombined away from diffraction optical element and transverse focusing extension diffraction optical element, made described sharpLight light beam forms transverse focusing extension with radially many focal length dispersion focal beam spot arrays on the workpiece.
Method as described above, wherein, the diffraction optical element is radial convergence extension diffraction optics unitPart, methods described includes：
Radial convergence extension diffraction optical element is combined with the focusing optic；
Make laser beam incident from radial convergence extension diffraction optical element, through the focusing optics unitAfter part is focused on, it is radiated on workpiece；
Make the laser beam that radially extension focal beam spot is formed on the workpiece.
Method as described above, wherein, further by horizontal many focal length diffraction optical elements and the footpathCombined to extension diffraction optical element is focused on, make laser beam shape on the workpieceExtension is radially focused on laterally many focal length spot arrays.
Method as described above, wherein, further by transverse focusing extension diffraction optical element with it is describedRadial convergence extension diffraction optical element is combined, and makes the laser beam on the workpieceForm transverse focusing extension and extend focusing surface with radial convergence.
Method as described above, wherein, further by a radial direction dispersive optical elements and the transverse focusingExtension diffraction optical element and radial convergence extension diffraction optical element are combined, and are made describedLaser beam forms horizontal radial convergence extension dispersion focusing surface on the workpiece.
Method as described above, wherein, the diffraction optical element is horizontal many focal length diffraction optical elements,Methods described includes：
The many focal length diffraction optical elements of the transverse direction are combined with the focusing optic；
Make laser beam incident from many focal length diffraction optical elements of the transverse direction, through the focusing opticAfter focusing, it is radiated on workpiece；
Make the laser beam that horizontal multi-focus hot spot is formed on the workpiece.
Method as described above, wherein, further by many focal length diffraction optical elements of radial direction and radiallyDispersive optical elements are combined with many focal length diffraction optical elements of the transverse direction, make the laser lightBeam forms laterally many focal lengths on the workpiece, and radially many focal length dispersions focus on array.
Method as described above, wherein, the diffraction optical element is transverse focusing extension diffraction optics unitPart, methods described includes：
Transverse focusing extension diffraction optical element is combined with the focusing optic；
Make laser beam incident from transverse focusing extension diffraction optical element, through the focusing optics unitAfter part is focused on, it is radiated on workpiece；
Make the laser beam that extending transversely focal beam spot is formed on the workpiece.
According to another aspect of the present invention, there is provided the Laser Focusing control method in a kind of material processing, bagInclude：
One radial direction dispersive optical elements are combined with focusing optic, the combination can increaseEffective depth of focus of material processing, without focus spot size and beam waist required by sacrifice；
Make laser beam incident from the focusing optic, footpath is increased through the radial direction dispersive optical elementsTo being radiated on workpiece after focal length；
Make the laser beam that the dispersion focal beam spot that radially extension is focused on is formed on the workpiece.
Method as described above, wherein, laser filament technology, the shape on the workpiece can also be usedInto a laser filament array.
Raising material (including metal, semiconductor, ceramics and fragile material) according to present invention description addsThe method of the Laser Focusing control of work speed, based on by increasing effective depth of focus without required by sacrificeFocus spot size or beam waist are realized improving such as fragile material process velocity.This can pass throughDiffraction optical element is realized, it is also possible to realized by dispersive optical elements.The method is proposed simultaneouslyThe method of introducing space focal length array further improves such as fragile material process velocity.
Laser Focusing control method in being processed to material of the invention below in conjunction with drawings and Examples is enteredThe detailed description of row.Other purposes of the invention, advantage and effect are below in conjunction with accompanying drawing and implementationWill become clearer and understand in the description of example.
Brief description of the drawings
Fig. 1 a show a laser-processing system for typical prior art.
Fig. 1 b show the optical focus figure of the Laser Processing of prior art.
Fig. 2 to Figure 14 is respectively to represent the laser in material processing according to an embodiment of the inventionThe schematic diagram of focusing controlling method.
Figure 15 is to represent that fragility material can be realized using laser filament technology in an embodiment of the present inventionThe schematic diagram of the cutting of material.
Figure 16 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.
Specific embodiment
The raising material specifically described according to present invention below is (including metal, semiconductor, ceramic and crispProperty material) process velocity Laser Focusing control method, based on by increasing effective depth of focus without sacrificialFocus spot size or beam waist required by domestic animal realize improving the process velocity of such as fragile material,This can be realized by diffraction optical element, it is also possible to be realized by dispersive optical elements.For example,The scheme realized by diffraction optical element is that a diffraction optical element is combined with focusing opticTogether, the combination can increase effective depth of focus of material processing, without the focus light required by sacrificeSpot size and beam waist；Make laser beam incident from the diffraction optical element, through the focusing lightLearn after element is focused on and be radiated on workpiece；The laser beam is formed on the workpiece hasThe hot spot or focusing surface of effective depth of focus.
Fig. 2 is to represent the Laser Focusing control method in material processing according to an embodiment of the inventionSchematic diagram.Referring to Fig. 2, the method can realize footpath using a kind of many focal length diffraction optical elements of radial directionTo many focal lengths (" radial direction " here is often referred to the direction in the direction or light path main shaft along beam transmission).Footpath is formed when many focal length diffraction optical elements 21 of the radial direction are combined with the focusing optic 23 of routineTo many focal length focal beam spots 25, these radial direction focal lengths are replicated and substantially equally spaced each other.Using theseRadially many focal lengths increase effective depth of focus without the focus beam waist spot size required by sacrifice to realize improvingFragile material process velocity.Relative to traditional single focal length optics, many focal length diffraction optics of radial directionElement 21 can realize radially many focal length numbers：Such as 2 to 10 (being illustrated as 5).
Fig. 3 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Fig. 3, the method uses a kind of radial convergence extension diffraction optical element can be withRealize radially extending away from Jiao, when radial convergence extension diffraction optical element 31 and the focusing light of routineLearn and radially extension focal beam spot 35 is formed when element 33 is combined.This radially extends to focus on not sacrifice wantsThe horizontal focus beam waist spot size asked, so as to realize improving fragile material process velocity.Relative to biographySingle focal length optics of system, radial convergence extension diffraction optical element can realize radial direction Rayleigh range(Rayleigh range) increases.
Fig. 4 is to represent the Laser Focusing controlling party in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Fig. 4, the method can be realized using a kind of many focal length diffraction optical elements of transverse directionHorizontal many focal lengths (" transverse direction " here is often referred to along the direction vertical with beam transmission direction),Formed when many focal length diffraction optical elements 41 of the transverse direction are combined with the focusing optic 43 of routineHorizontal many focal length focal beam spots 45, these horizontal focal lengths are replicated and substantially equally spaced each other.These are horizontalIncrease effective depth of focus without the sagittal focus beam waist spot size required by sacrifice to many focal lengths to improve materialExpect the process velocity of (including metal, semiconductor, ceramics and fragile material).
Fig. 5 is to represent the Laser Focusing controlling party in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Fig. 5, the method can be real using a kind of transverse focusing extension diffraction optical elementExisting transverse focusing extension, when transverse focusing extension diffraction optical element 51 and the focusing optics of routineExtending transversely focal beam spot 55 is formed when element 53 is combined.This extending transversely is focused on does not sacrifice requiredSagittal focus beam waist spot size, so as to realize improving material (including metal, semiconductor, ceramicsAnd fragile material) process velocity.
Fig. 6 is to represent the Laser Focusing controlling party in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Fig. 6, the method is more with radial direction using a kind of many focal length diffraction optical elements of transverse directionFocal length diffraction optical element combination 61 can realize the horizontal and many focal length spot arrays of radial direction, wherein, it is horizontalTo many focal length diffraction optical elements with radially many focal length diffraction optical elements in the optical path can be with sequence (noGradation sequence), it is also possible to will laterally many focal length diffraction optical elements and radially many focal length diffraction optical elementsFor example it is integrated on one piece of substrate.Formed when it combine with conventional focusing optic 63 laterally andRadially many focal length spot arrays 65.This does not sacrifice laterally required with radially many focal length spot arraysSagittal focus beam waist spot size, so as to realize improving fragile material process velocity.
Fig. 7 is to represent the Laser Focusing controlling party in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Fig. 7, the method is using a kind of transverse focusing extension diffraction optical element and radial directionMany focal length diffraction optical element combinations 71 can realize transverse focusing extension and radially many focal length spot arrays,Wherein, transverse focusing extension diffraction optical element in the optical path may be used with radially many focal length diffraction optical elementsWith sequence (regardless of order), it is also possible to by transverse focusing extension diffraction optical element and radially many focal lengthsDiffraction optical element is for example integrated on one piece of substrate.When it is combined with conventional focusing optic 73When form transverse focusing extension with radially many focal length spot arrays 75.This transverse focusing extends and radial directionMany focal length spot arrays do not sacrifice required sagittal focus beam waist spot size, so as to realize improving crispProperty material process velocity.
Fig. 8 is to represent the Laser Focusing controlling party in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Fig. 8, the method extends diffraction optical element and transverse direction using a kind of radial convergenceMany focal length diffraction optical element combinations 81 can realize radial convergence extension with laterally many focal length spot arrays85.Radial convergence extends diffraction optical element and laterally many focal length diffraction optical elements in the optical path can be withSequence (regardless of order), it is also possible to which radial convergence extension diffraction optical element spreads out with laterally many focal lengthsOptical element is penetrated for example to be integrated on one piece of substrate.When it is combined with conventional focusing optic 83Radial convergence extension is formed with laterally many focal length spot arrays 85.This radial convergence extends many with horizontalFocal length spot array does not sacrifice required horizontal focus beam waist spot size, so as to realize improving fragilityMaterial process velocity.
Fig. 9 is to represent the Laser Focusing controlling party in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Fig. 9, the method is using a kind of transverse focusing extension diffraction optical element and radial directionFocusing extension diffraction optical element combination 91 can realize that transverse focusing extension is focused on radial convergence extensionFace.Wherein, transverse focusing extension diffraction optical element extends diffraction optical element in light with radial convergenceLu Zhongke is with sequence (regardless of order), it is also possible to by transverse focusing extension diffraction optical element and radial directionExtension diffraction optical element is focused on for example to be integrated on one piece of substrate.When itself and conventional focusing optics are firstTransverse focusing extension is formed when part 93 is combined and extends focusing surface 95 with radial convergence.This transverse focusing prolongsIt is long to realize improving fragile material process velocity with radial convergence extension focusing surface.
Additionally, realizing that the scheme that radial direction focal length extends is by a footpath crossed disperstion by radial direction dispersive optical elementsOptical element is combined with focusing optic, and the combination can increase the effective of material processingDepth of focus, without focus spot size and beam waist required by sacrifice；Laser beam is set to gather from describedBurnt optical element is incident, and workpiece is radiated at after increasing radial direction focal length through the radial direction dispersive optical elementsOn；Make the laser beam that hot spot or focusing surface with effective depth of focus are formed on the workpiece..
Figure 10 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Figure 10, for example, increase radially burnt by adjusting spherical dispersion (aberration)Away from.This dispersive optical elements 101 can be with certain thickness transparent material, dispersing optics unitPart 101 for example may be located at the rear of focusing optic 103, when itself and conventional focusing optics are firstThe dispersion focal beam spot 105 of radially extension is formed when part 103 is combined.This radially extends to focus on does not sacrificeRequired horizontal focus beam waist spot size, so as to realize improving fragile material process velocity.
Figure 11 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Figure 11, by a kind of many focal length diffraction optical elements 114 of radial direction and radial direction colorThe combination of dispersive optical element 111 can realize radially many focal length dispersion focal beam spot arrays.Radially many focal lengthsDiffraction optical element in the optical path can be with sequence with radial direction dispersive optical elements, it is also possible to will be radially multifocalFor example it is integrated on one piece of substrate away from diffraction optical element and radial direction dispersive optical elements.When itself and routineFocusing optic 113 form radially many focal length dispersion focal beam spot arrays 115 when combining.This footpathRequired horizontal focus beam waist spot size is not sacrificed to many focal length dispersion focal beam spot arrays, so thatRealize improving fragile material process velocity.
Figure 12 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Figure 12, by a kind of transverse diameter to many focal length diffraction optical elements 124 and radial directionThe combination of dispersive optical elements 121 can realize that laterally many focal length dispersions of many focal lengths radial directions focus on arrays.It is horizontalRadially many focal length diffraction optical elements in the optical path can be with sequence with radial direction dispersive optical elements, it is also possible toTransverse diameter is integrated on one piece of substrate to many focal length diffraction optical elements, it is also possible to by transverse diameter to many focal lengthsDiffraction optical element is integrated on one piece of substrate with radial direction dispersive optical elements.When itself and conventional focusingOptical element 123 forms laterally many focal lengths and radially many focal length dispersion focal beam spot arrays 125 when combining.Laterally many focal lengths and many focal length dispersion focal beam spot arrays of radial direction do not sacrifice required horizontal focus for thisBeam waist spot size, so as to realize improving fragile material process velocity.
Figure 13 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Figure 13, by a kind of extension of transverse focusing, radially many focal length diffraction optics are firstPart 134 is combined with radial direction dispersive optical elements 131 can realize transverse focusing extension with radially many focal lengthsDispersion focal beam spot array.Transverse focusing extension, radially many focal length diffraction optical elements and footpath crossed disperstionOptical element in the optical path can be with sequence, it is also possible to by transverse focusing extension and radially many focal length diffraction lightsLearn element to be integrated on one piece of substrate, it is also possible to by transverse focusing extension and radially many focal length diffraction opticsElement is integrated on one piece of substrate with radial direction dispersive optical elements.When itself and conventional focusing opticTransverse focusing extension is formed during 133 combination with radially many focal length dispersion focal beam spot arrays 135.This is horizontalCan realize improving fragile material processing speed with radially many focal length dispersion focal beam spot arrays to extension is focused onDegree.
Figure 14 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Figure 14, by a kind of horizontal radial convergence extension diffraction optical element 144 and footpathThe combination of crossed disperstion optical element 141 can realize horizontal radial convergence extension dispersion focusing surface.Transverse diameter is to poly-Jiao's extension diffraction optical element in the optical path can be with sequence with radial direction dispersive optical elements, it is also possible to by horizontal strokeRadial convergence extension diffraction optical element is integrated on one piece of substrate, it is also possible to by horizontal radial convergence extensionDiffraction optical element is integrated on one piece of substrate with radial direction dispersive optical elements.When itself and conventional focusingOptical element 143 forms horizontal radial convergence extension dispersion focusing surface 145 when combining.This horizontal radial convergenceExtension dispersion focusing surface can be realized improving fragile material process velocity.
Ultrashort pulse laser can also coordinate poly- in fragile material such as glass and sapphire material cuttingBurnt optical element 153 realizes the cutting of fragile material 158 using laser filament technology 154, such as schemesShown in 15.
Figure 16 is to represent the Laser Focusing control in material processing according to another embodiment of the inventionThe schematic diagram of method.Referring to Figure 16, using laterally many focal length diffraction optical elements, radially many focal lengths spread outPenetrate in optical element, horizontal focal length extension diffraction optical element and radial direction focal length extension diffraction optical elementAny diffraction optical element 161 or its combination can realize lateral/radial laser filament array.When itLateral/radial laser filament array 164 is formed when being combined with conventional focusing optic 163, theseLateral/radial laser filament is replicated and substantially equally spaced each other.These lateral/radial laser filaments battle arrayRow can realize being greatly enhanced the process velocity of fragile material 168.
The above is only some implementations of the Laser Focusing control method in material processing of the inventionExample, above-mentioned design of the invention, those skilled in the art can also various changes can be made to thisAnd conversion, but these changes and conversion belong to the scope of the present invention.