Laser-based material processing apparatus and methods
First Claim
1. A method of scribing, dicing, or cutting to remove material from a region of a workpiece having a composite material comprising at least two non-metallic materials having different optical properties, said method comprising:
- directing laser pulses toward said composite material of said workpiece to scribe, dice, or cut to remove material from the region of the workpiece having said composite material, the composite material comprising at least one portion of matrix and at least one portion of reinforcement in which the matrix surrounds and supports the reinforcement, said composite material comprising reinforced fiber, the laser pulses having at least one pulse width in the range from 10 fs to 500 picoseconds and a pulse repetition rate in the range from 10 kHz to 10 MHz;
focusing said laser pulses into laser spots to scribe, dice, or cut to remove material from the region of the workpiece having said composite material, said laser spots having spot sizes (1/e2) in a range from 1 micron to 100 μ
m, wherein at least one said laser pulse provides a power density above a threshold for nonlinear absorption in said reinforced fiber of said composite material at a wavelength of said at least one laser pulse, wherein said power density is in a range from 1012 W/cm2 to 1014 W/cm2; and
positioning said laser spots relative to said workpiece to scribe, dice, or cut to remove material from the region of the workpiece having said composite material, said positioning such that a spatial overlap between adjacent focused spots (1/e2) for removal of said composite material is sufficient for scribing, dicing, or cutting said workpiece at said wavelength, pulse width, repetition rate, and power density,wherein said method controls heat accumulation within one or more materials of said workpiece region, while limiting accumulation of unwanted material about said region,wherein said scribing, dicing, or cutting said workpiece comprises depthwise removing at least 25 μ
m up to 150 μ
m of composite material with said laser pulses in a single pass of laser processing pulses relative to said composite material, with said power density and operation in the nonlinear absorption regime in said composite material.
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Accused Products
Abstract
Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse width sufficiently short so that material is efficiently removed by nonlinear optical absorption from the region and a quantity of heat affected zone and thermal stress on the material within the region, proximate to the region, or both is reduced relative to a quantity obtainable using a laser with longer pulses. In at least one embodiment, an ultrashort pulse laser system may include at least one of a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a composite material.
120 Citations
31 Claims
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1. A method of scribing, dicing, or cutting to remove material from a region of a workpiece having a composite material comprising at least two non-metallic materials having different optical properties, said method comprising:
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directing laser pulses toward said composite material of said workpiece to scribe, dice, or cut to remove material from the region of the workpiece having said composite material, the composite material comprising at least one portion of matrix and at least one portion of reinforcement in which the matrix surrounds and supports the reinforcement, said composite material comprising reinforced fiber, the laser pulses having at least one pulse width in the range from 10 fs to 500 picoseconds and a pulse repetition rate in the range from 10 kHz to 10 MHz; focusing said laser pulses into laser spots to scribe, dice, or cut to remove material from the region of the workpiece having said composite material, said laser spots having spot sizes (1/e2) in a range from 1 micron to 100 μ
m, wherein at least one said laser pulse provides a power density above a threshold for nonlinear absorption in said reinforced fiber of said composite material at a wavelength of said at least one laser pulse, wherein said power density is in a range from 1012 W/cm2 to 1014 W/cm2; andpositioning said laser spots relative to said workpiece to scribe, dice, or cut to remove material from the region of the workpiece having said composite material, said positioning such that a spatial overlap between adjacent focused spots (1/e2) for removal of said composite material is sufficient for scribing, dicing, or cutting said workpiece at said wavelength, pulse width, repetition rate, and power density, wherein said method controls heat accumulation within one or more materials of said workpiece region, while limiting accumulation of unwanted material about said region, wherein said scribing, dicing, or cutting said workpiece comprises depthwise removing at least 25 μ
m up to 150 μ
m of composite material with said laser pulses in a single pass of laser processing pulses relative to said composite material, with said power density and operation in the nonlinear absorption regime in said composite material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A method of processing a workpiece having a composite material comprising at least two different materials with different properties and functionalities, said different materials comprising at least one of a dielectric material or a metal material, said method comprising:
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irradiating said composite material of said workpiece with a series of laser pulses to remove at least a portion of said composite material of said workpiece, the composite material comprising at least one portion of matrix and at least one portion of reinforcement in which the matrix surrounds and supports the reinforcement, said composite material comprising reinforced fiber, at least two pulses of the series having different characteristics that are applied to different materials of said workpiece, said series of laser pulses comprising at least one pulse providing a power density above a threshold for nonlinear absorption in said reinforced fiber of said composite material at a wavelength of said at least one laser pulse, said power density in a range from 1012 W/cm2 to 1014 W/cm2; and controlling heat-affected zone (HAZ) during processing of said workpiece such that at least one HAZ generated during removal of at least one of the dielectric material or the metal material is increased depthwise relative to at least one HAZ generated during removal of a portion of said composite material of said workpiece, wherein said processing said workpiece comprises depthwise removing at least 25 μ
m up to 150 μ
m of composite material with said laser pulses in a single pass of laser processing pulses relative to said composite material, with said power density and operation in the nonlinear absorption regime in said composite material.
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31. A laser-based system for scribing, dicing, or cutting a workpiece having a composite material comprising at least two different materials with different properties and functionalities, the laser-based system comprising:
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said workpiece, wherein said composite material of said workpiece comprises at least one portion of matrix and at least one portion of reinforcement in which the matrix surrounds and supports the reinforcement, said composite material comprising reinforced fiber; a source of optical pulses, at least one pulse having a wavelength longer than a linear absorption edge of said composite material of said workpiece; an optical amplification system configured to amplify a pulse from said source to a pulse energy of at least 1 μ
J and to generate output optical pulses having at least one pulse width in a range from 10 fs to 500 ps;a modulation system, comprising at least one optical modulator, configured to adjust a repetition rate of said output optical pulses to be within a range from 10 kHz to 10 MHz; a beam delivery system configured to focus and deliver pulsed laser beams to the workpiece to scribe, dice, or cut the workpiece having the composite material, wherein a pulsed beam is focused into a spot size (1/e2) in a range from 1 μ
m to 100 μ
m, said focused beam providing a peak power density above a threshold for nonlinear absorption in said reinforced fiber of said composite material at a wavelength of said laser pulse, said peak power density in a range from 1012 W/cm2 to 1014 W/cm2;a positioning system configured to position said beams relative to said workpiece at a rate in a range from 1 mm/sec to 20 m/sec; and a controller configured to be coupled to at least said positioning system, said controller configured to control a spatial overlap between adjacent focused beams during scribing, dicing, or cutting of the workpiece at said repetition rate, wherein said laser-based system is configured to depthwise remove at least 25 μ
m up to 150 μ
m of composite material with said pulsed laser beams in a single pass of said pulsed laser beams relative to said composite material, with said power density and operation in the nonlinear absorption regime in said composite material.
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Specification