Laser machining apparatus, method for operating the same, and method for machining

Abstract

Numerous specific examples are disclosed. Many of them relate to methods of forming a through hole in a workpiece such as a printed circuit board. Some embodiments relate to techniques for indirectly ablating an electrical conductor structure, such as a printed circuit board, by distributing laser energy spatially through the region of the electrical conductor prior to indirectly ablating the region. Other embodiments relate to techniques for temporally dividing laser pulses, modulating optical power within laser pulses, and the like.

Description

[0001] This application is a divisional application of the invention patent application with application number 202080029432.9, application date May 29, 2020, priority date June 10, 2019, and invention name “Laser processing equipment, operation method thereof, and method for processing workpieces using the same”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application No. 62 / 859,572, filed on June 10, 2019, U.S. Provisional Application No. 62 / 930,287, filed on November 4, 2019, U.S. Provisional Application No. 62 / 970,648, filed on February 5, 2020, and U.S. Provisional Application No. 63 / 026,564, filed on May 18, 2020, each of which is incorporated herein by reference in its entirety. Technical Field

[0004] Embodiments of the present invention relate to apparatus and techniques for laser processing of workpieces. Background Art

[0005] Laser processes are often used to form blind vias and through-holes (typically <150 μm diameter) in workpieces such as printed circuit boards (both rigid and flexible varieties). To form the through-holes, the laser processes that may be used are so-called "punching" processes, "trepanning" processes, or some combination thereof. During the punching process, a laser energy beam is directed onto the workpiece, held stationary, while the through-hole is formed. In contrast, during the trepanning process, the laser energy beam is moved relative to the workpiece to form the through-hole. Conventionally, during the trepanning process, the laser energy beam is moved so that the points on the workpiece are irradiated by the laser energy beam in a spiral or circular pattern. Summary of the invention

[0006] One embodiment may be characterized as a method of forming a feature in a workpiece comprising a first structure and a second structure, wherein the feature comprises an opening formed in the first structure. The method may include scanning a beam of laser energy directed onto the workpiece such that the beam of laser energy is incident on the first structure to sequentially deliver the laser energy to a plurality of spatially distinct spot locations in a scan pattern. The scanning may include the following actions: a) delivering the laser energy to at least two of the plurality of spatially distinct spot locations to distribute the laser energy within a region of the workpiece where the feature is to be formed; and b) after a), delivering the laser energy to at least two of the plurality of spatially distinct spot locations to form the opening by indirectly ablating the first structure within the region.

[0007] Another embodiment can be characterized as an apparatus for forming a feature in a workpiece including a first structure and a second structure, wherein the feature comprises an opening formed in the first structure. The apparatus can include: a laser source operable to generate a laser energy beam, wherein the laser energy beam can propagate along a beam path to be incident on the first structure of the workpiece; a positioner operable to deflect the beam path; and a controller communicatively coupled to the positioner. The controller can be configured to control an operation of the positioner to implement the scanning process described in the above paragraph.

[0008] Another embodiment can be characterized as an apparatus comprising a laser source, an acousto-optic deflector (AOD) system, and a controller. The laser source is operable to generate a laser energy beam having at least one laser pulse, wherein the laser energy beam can propagate along a beam path to a workpiece. The AOD system is operable to deflect the beam path and includes a first AOD operable to deflect the beam path along a first axis in response to a first RF signal applied thereto. The controller is communicatively coupled to the AOD system and is configured to control the operation of the AOD system, whereby the frequency of the first RF signal is changed at least twice to temporally divide a common laser pulse incident on the AOD system into a plurality of pulse segments, wherein the frequency of the first RF signal is changed at a rate greater than or equal to 20 kHz.

[0009] Yet another embodiment can be characterized as an apparatus comprising: a laser source; a first scanning head having a scanning lens; a second scanning head having a scanning lens; a positioner; and a controller. The laser source is operable to generate a laser energy beam having at least one laser pulse, wherein the laser energy beam is propagable along a beam path to a workpiece. The positioner is operable to selectively deflect the beam path between the first scanning head and the second scanning head. The controller is communicatively coupled to the positioner and configured to control operation of the positioner to temporally divide a common laser pulse incident on the positioner into a plurality of pulse segments comprising a first pulse segment group and a second pulse segment group. The controller is further configured to control operation of the positioner to: deflect the first pulse segment group to the first scanning head; and deflect the second pulse segment group to the second scanning head, wherein at least one pulse segment in the second pulse segment group temporally exists between two consecutive pulse segments in the first pulse segment group. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 and Fig.31 Laser processing equipment according to some specific examples of the present invention are schematically illustrated.

[0011] Figure 2 A multi-axis AOD system that may be incorporated into a first positioner according to one specific example is schematically illustrated.

[0012] Figure 3 and Figure 4 Techniques for implementing pulse slicing according to some specific examples are schematically illustrated.

[0013] Figure 5 The cross-sectional view schematically illustrates a specific example of a workpiece that can be processed by a laser processing device.

[0014] Figure 6 and Figure 7 To schematically illustrate the use of laser processing equipment to form Figure 5 Cross-sectional views of specific examples of features in the workpiece being discussed.

[0015] Figures 8 to 22 and Fig.24 (a) is a diagram illustrating an exemplary embodiment of a scanning pattern, wherein a plurality of scanning patterns may be scanned along the plurality of scanning patterns from a guide to a Figure 5 The processing light spot of the laser energy beam irradiating on the workpiece discussed is formed as follows Figure 6 and Figure 7 The characteristics of these are discussed.

[0016] Fig.23 , Fig.24 (b) Fig.25 and Fig.26 are respectively along the Fig.14 , Fig.24 (a) Fig.16 and Fig.15 The scanning pattern shown in FIG. 1 is formed on the workpiece (for example, Figure 6 A micrograph of a blind via in FIG. Fig.23 and Fig.24 In (b), the diameter d of the blind via is about 100 μm. Fig.25 In the example, the diameter d of the blind via is about 75 μm. Fig.26 In the embodiment, the diameter d of each blind via hole is about 180 μm.

[0017] Fig. 27 A diagram schematically illustrating a plan view of the shape of a through-hole opening formed by scanning a processing spot along a second type scanning pattern.

[0018] Fig.28 To illustrate the generation of an elliptical opening (such as Fig. 27 FIG. 4 is a diagram of an exemplary circular configuration of point locations of through holes (exemplarily shown in FIG. 4 ).

[0019] Fig.29 To illustrate the opening shape ratio produced by scanning with a laser energy beam Fig. 27 FIG. 4 is a diagram of an exemplary elliptical arrangement of the point positions of through holes having a high degree of roundness of the opening shape shown in FIG.

[0020] Fig.30 A set of diagrams illustrating a technique for implementing pulse slicing during blind via formation according to one specific example.

[0021] Figures 32 to 45 A diagram illustrating techniques for implementing pulse slicing during the formation of various features according to some specific examples.

[0022] Fig.46 , Fig.48 and Fig.49 are micrographs of via openings formed according to some specific examples of the present invention.

[0023] Fig.47 , Fig.50 and Fig.51 To illustrate the use of forming a Fig.48 The technique of opening a through hole is shown in FIG. DETAILED DESCRIPTION

[0024] Exemplary embodiments are described herein with reference to the accompanying drawings. Unless expressly stated otherwise, in the drawings, the size, position, etc. of components, features, elements, etc., and any distances therebetween are not necessarily to scale, but are exaggerated for clarity. In the drawings, the same numbers refer to the same elements throughout. Therefore, the same or similar numbers may be described with reference to other drawings, even if the multiple numbers are not mentioned or described in the corresponding drawings. Also, even elements not indicated by reference numbers may be described with reference to other drawings.

[0025] The terms used herein are only for the purpose of describing specific examples, and are not intended to be limiting. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meanings as generally understood by those skilled in the art. As used herein, unless the context clearly indicates otherwise, the singular forms "a / an" and "the" are intended to include multiple forms. It should be recognized that the term "comprising" specifies the existence of stated features, wholes, steps, operations, elements and / or components when used in this specification, but does not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their groups. Unless otherwise specified, when describing a value range, the value range includes both the upper and lower limits of the range and any sub-ranges therebetween. Unless otherwise indicated, terms such as "first", "second" and the like are only used to distinguish one element from another. For example, a node may be referred to as a "first node", and similarly, another node may be referred to as a "second node", or vice versa.

[0026] Unless otherwise indicated, the terms "about," "approximately," and the like mean that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller as necessary, reflecting tolerances, conversion factors, rounding, measurement errors, and the like, as well as other factors known to those skilled in the art. For ease of description, spatially relative terms such as "below," "beneath," "lower," "above," and "upper," and the like, may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the accompanying drawings. It should be recognized that the plurality of spatially relative terms are intended to encompass different orientations in addition to the orientation depicted in the accompanying drawings. For example, if the objects in the figures are flipped, an element described as "below" or "beneath" other elements or features will then be oriented "above" the other elements or features. Thus, the exemplary term "below" may encompass both the above and below orientations. Objects may be otherwise oriented (eg, rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0027] The section headings used herein are for organizational purposes only, and unless expressly stated otherwise, the section headings should not be construed as limiting the subject matter described. It should be understood that many different forms, embodiments, and combinations are possible without departing from the spirit and teachings of the invention, and therefore, the invention should not be considered limited to the example embodiments set forth herein. Rather, the examples and embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0028] I. Overview

[0029] Embodiments described herein generally relate to methods and apparatus for laser processing (or, more simply, "processing") a workpiece. Generally speaking, the processing is accomplished in whole or in part by irradiating the workpiece with laser radiation to heat, melt, vaporize, ablate, crack, discolor, polish, roughen, carbonize, foam, or otherwise modify one or more properties or characteristics (e.g., in terms of chemical composition, atomic structure, ionic structure, molecular structure, electronic structure, microstructure, nanostructure, density, viscosity, refractive index, magnetic permeability, relative permittivity, texture, color, hardness, electromagnetic radiation transmittance, or the like, or any combination thereof) of one or more materials forming the workpiece. The material to be processed may be external to the workpiece before or during processing, or may be completely within the workpiece (i.e., not external to the workpiece) before or during processing.

[0030] Specific examples of processes that may be performed by the disclosed apparatus for laser processing and described in more detail below include through-hole drilling or other hole formation. It will be appreciated that the specific examples described herein may be extended to performing or otherwise facilitating cutting, perforating, welding, scribing, engraving, marking (e.g., surface marking, subsurface marking, etc.), laser-induced forward transfer, cleaning, bleaching, bright pixel repair (e.g., color filter darkening, modifying OLED materials, etc.), removing coatings, surface texturing (e.g., roughening, smoothing, etc.), the like, or any combination thereof. Thus, as a result of processing, one or more features that may be formed on or in a workpiece may include openings, slots, through-holes or other holes, recesses, grooves, scribe lines, saw cuts, recessed areas, conductive traces, ohmic contacts, photoresist patterns, artificial or machine-readable markings (e.g., consisting of one or more regions in or on a workpiece having one or more visually or texturally distinguishable characteristics), or the like, or any combination thereof. Features such as openings, slots, through holes, holes, etc. can have any suitable or desirable shape (e.g., circular, oval, square, rectangular, triangular, annular, or the like, or any combination thereof) when viewed from a top plan view. In addition, features such as openings, slots, through holes, holes, etc. can extend completely through the workpiece (e.g., to form a so-called "through via", "through hole", etc.) or only partially through the workpiece (e.g., to form a so-called "blind via", "blind hole", etc.).

[0031] The workpieces that can be processed can generally be characterized as being formed from one or more metals, polymers, ceramics, composites, or any combination thereof (e.g., whether alloys, compounds, mixtures, solutions, composites, etc.). Examples of workpieces specifically described herein include panels of printed circuit boards (PCBs) (also referred to herein as "PCB panels"), PCBs, flexible printed circuits (FPCs), integrated circuits (ICs), and IC packages (ICPs). However, it will be appreciated that other types of workpieces may also be beneficially processed, such as light emitting diodes (LEDs), LED packages, semiconductor wafers, electronic or optical device substrates (e.g., made of Al2O3, AlN, BeO, Cu, GaAS, GaN, Ge, InP, Si, SiO2, SiC, Si 1-x Ge x etc. or any combination or alloy thereof), lead frames, lead frame blanks, articles formed of plastic, unstrengthened glass, heat-strengthened glass, chemically strengthened glass (e.g., via an ion exchange process), quartz, sapphire, plastic, silicon, etc., components of electronic displays (e.g., substrates having TFTs, color filters, organic LED (OLED) arrays, quantum dot LED arrays, etc., or any combination thereof formed thereon), lenses, mirrors, screen protectors, turbine blades, powders, films, foils, plates, molds (e.g., wax molds, molds for injection molding, overmolding processes, etc.), fabrics (woven, felt, etc.), surgical instruments, medical implants, consumer packaged goods, shoes, bicycles, automobiles, automotive or aviation parts (e.g., frames, body panels, etc.), appliances (e.g., microwave ovens, ovens, refrigerators, etc.), device housings (e.g., for watches, computers, smart phones, tablet computers, wearable electronic devices, etc., or any combination thereof).

[0032] Thus, processable materials include: one or more metals, such as Al, Ag, Au, Cu, Fe, In, Mg, Pt, Sn, Ti, etc., or any combination thereof (e.g., as alloys, composites, etc.); conductive metal oxides (e.g., ITO, etc.); transparent conductive polymers; ceramics; waxes; resins; inorganic dielectric materials (e.g., used as interlayer dielectric structures, such as silicon oxide, silicon nitride, silicon oxynitride, etc., or any combination thereof); low-k dielectric materials (e.g., methyl silsesquioxane (MSQ), silane trioxide (HSQ), tetraethyl orthosilicate (FTEOS), etc., or any combination thereof); organic dielectric materials (e.g., SILK, benzocyclobutene, Nautilus (all manufactured by Dow); polytetrafluoroethylene (manufactured by DuPont); FLARE (manufactured by Allied Chemical), or any combination thereof); glass fiber; polymer materials (polyamide, polyimide, polyester, polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyphenylene sulfide, polyethersulfone, polyetherimide, polyetheretherketone, liquid crystal polymer, acrylonitrile butadiene styrene, and any compound, composite or alloy thereof); leather; paper; build-up materials (e.g., ANJINOMOTO build-up film, also known as "ABF", etc.); glass-reinforced epoxy resin laminates (e.g., FR4); prepregs; solder resists, etc.; or any composites, laminates or other combinations thereof.

[0033] II. System Overview

[0034] Figure 1 A laser processing device according to a specific example of the present invention is schematically illustrated.

[0035] refer to Figure 1 , a laser processing apparatus 100 (also referred to herein simply as an "apparatus") for processing a workpiece 102 can be characterized as including a laser source 104 for generating a laser energy beam, a first positioner 106, a second positioner 108, a third positioner 110, and a scan lens 112. It should be noted that each of the second positioner 108, the third positioner 110, and the scan lens 112 is optional and can be omitted from the apparatus 100. The scan lens 112 and the second positioner 108 can be integrated into a common housing or "scan head" 120 as appropriate.

[0036] As discussed in more detail below, the first positioner 106 is operable to diffract the laser energy beam so as to deflect the beam path 114 to any of the second positioners 108. As used herein, the term "beam path" refers to the path along which the laser energy in the laser energy beam travels when propagating from the laser source 104 to the scan lens 112. When deflecting the beam path 114 to the second positioner 108, the beam path 114 may be deflected to any angle within a first angular range (also referred to herein as a "primary angular range 116") (e.g., as measured relative to the beam path 114 incident on the first positioner 106).

[0037] The second positioner 108 is operable to diffract, reflect, refract, etc., or any combination thereof, the laser energy beam generated by the laser source 104 and deflected (i.e., to "deflect") the laser energy beam by the first positioner 106 so as to deflect the beam path 114 to the scan lens 112. When deflecting the beam path 114 to the scan lens 112, the second positioner 108 can deflect the beam path 114 by any angle (e.g., as measured relative to the optical axis of the scan lens 112) within a second angular range (also referred to herein as the "auxiliary angular range 118").

[0038] The laser energy deflected to the scan lens 112 is typically focused by the scan lens 112 and transmitted to propagate along the beam axis for delivery to the workpiece 102. The laser energy delivered to the workpiece 102 can be characterized as having a Gaussian spatial intensity profile or a non-Gaussian (i.e., "shaped") spatial intensity profile (e.g., a "top-hat" spatial intensity profile, a super-Gaussian spatial intensity profile, etc.).

[0039] As used herein, the term "spot size" refers to the diameter or maximum spatial width of a delivered laser energy beam at the location where the beam axis intersects the area of ​​the workpiece 102 to be at least partially processed by the delivered laser energy beam (also referred to as a "process spot", "spot location", or simply "spot"). For purposes of discussion herein, spot size is measured as the optical intensity from the beam axis to the beam axis drops to at least 1 / e of the optical intensity. 2. In general, the spot size of the laser energy beam will reach a minimum at the beam waist. Once delivered to the workpiece 102, the laser energy within the beam may be characterized as irradiating the workpiece 102 with a spot size ranging from 2 μm to 200 μm. However, it should be understood that the spot size can be less than 2 μm or greater than 200 μm. Therefore, the laser energy beam delivered to the workpiece 102 may have a spot size greater than, less than, or equal to 2 μm, 3 μm, 5 μm, 7 μm, 10 μm, 15 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 80 μm, 100 μm, 150 μm, 200 μm, etc., or between any of the values.

[0040] The device 100 may also include one or more other optical components (for example, a beam dump, a beam expander, a beam shaper, a beam splitter, an aperture, a filter, a collimator, a lens, a mirror, a prism, a polarizer, a phase retarder, a diffractive optical element (commonly referred to in the art as DOE), a refractive optical element (commonly referred to in the art as ROE), etc. or any combination thereof) to focus, expand, collimate, shape, polarize, filter, split, combine, trim, absorb or otherwise modify, adjust, guide, etc. the laser energy beam as it propagates along the beam path 114 so as to guide the laser energy beam to the aforementioned first positioner 106, the second positioner, etc. or any combination thereof.

[0041] A. Laser source

[0042] In one embodiment, the laser source 104 is operable to generate laser pulses. Thus, the laser source 104 may include a pulsed laser source, a CW laser source, a QCW laser source, a burst mode laser, or the like, or any combination thereof. In the case where the laser source 104 includes a QCW or CW laser source, the laser source 104 may be operated in a pulsed mode, or may be operated in a non-pulsed mode but further includes a pulse gating unit (e.g., an acousto-optic (AO) modulator (AOM), a chopper, etc.) to temporally modulate the laser radiation beam output from the QCW or CW laser source. Although not illustrated, the apparatus 100 may optionally include one or more harmonic generation crystals (also referred to as "wavelength conversion crystals") configured to convert the wavelength of light output by the laser source 104. However, in another embodiment, the laser source 104 may be provided as a QCW laser source or a CW laser source and does not include a pulse gating unit. Thus, the laser source 104 may be characterized broadly as being operable to produce a laser energy beam, which may manifest itself as a series of laser pulses or as a continuous or quasi-continuous laser beam, which may thereafter propagate along the beam path 114. Although many of the specific examples discussed herein refer to laser pulses, it should be recognized that a continuous or quasi-continuous beam may alternatively or additionally be used whenever appropriate or desired.

[0043] The laser energy output by the laser source 104 may have one or more wavelengths in the ultraviolet (UV), visible light, or infrared (IR) range of the electromagnetic spectrum. The laser energy in the UV range of the electromagnetic spectrum may have one or more wavelengths in the range of 10 nm (or around 10 nm) to 385 nm (or around 385 nm), such as 100 nm, 121 nm, 124 nm, 157 nm, 200 nm, 334 nm, 337 nm, 351 nm, 380 nm, etc., or between any of the values. The laser energy in the visible green range of the electromagnetic spectrum may have one or more wavelengths in the range of 500 nm (or around 500 nm) to 560 nm (or around 560 nm), such as 511 nm, 515 nm, 530 nm, 532 nm, 543 nm, 568 nm, etc., or between any of the values. Laser energy in the IR range of the electromagnetic spectrum may have one or more wavelengths in the range of 750 nm (or around 750 nm) to 15 μm (or around 15 μm), such as 600 nm to 1000 nm, 752.5 nm, 780 nm to 1060 nm, 799.3 nm, 980 nm, 1047 nm, 1053 nm, 1060 nm, 1064 nm, 1080 nm, 1090 nm, 1152 nm, 1150 nm to 1350 nm, 1540 nm, 2.6 μm to 4 μm, 4.8 μm to 8.3 μm, 9.4 μm, 10.6 μm, etc., or between any of the values.

[0044] When the laser energy beam is presented as a series of laser pulses, the laser pulses output by the laser source 104 may have a pulse width or pulse duration (i.e., based on the full-width at half-maximum (FWHM) of the optical power in the pulse versus time) in the range of 10 fs to 900 ms. However, it will be appreciated that the pulse duration may be less than 10 fs or greater than 900 ms. Therefore, at least one laser pulse output by the laser source 104 may have a speed less than, greater than or equal to 10 fs, 15 fs, 30 fs, 50 fs, 100 fs, 150 fs, 200 fs, 300 fs, 500 fs, 600 fs, 750 fs, 800 fs, 850 fs, 900 fs, 950 fs, 1 ps, 2 ps, 3 ps, 4 ps, 5 ps, 7 ps, 10 ps, ​​15 ps, 25 ps, 50 ps, ​​75 ps, 100 ps, ​​200 ps, ​​500 ps, ​​1 ns, 1.5 ns, s, 2ns, 5ns, 10ns, 20ns, 50ns, 100ns, 200ns, 400ns, 800ns, 1000ns, 2μs, 5μs, 10μs, 15μs, 20μs, 25μs, 30μs, 40μs, 50μs, 100μs, 300μs, 500μs, 900μs, 1ms, 2ms, 5ms, 10ms, 20ms, 50ms, 100ms, 300ms, 500ms, 900ms, 1s, etc., or a pulse duration between any of the values.

[0045] The laser pulses output by the laser source 104 may have an average power in the range of 5 mW to 50 kW. However, it should be understood that the average power can be less than 5 mW or greater than 50 kW. Therefore, the laser pulses output by the laser source 104 may have an average power less than, greater than, or equal to the following values: 5 mW, 10 mW, 15 mW, 20 mW, 25 mW, 50 mW, 75 mW, 100 mW, 300 mW, 500 mW, 800 mW, 1 W, 2 W, 3 W, 4 W, 5 W, 6 W, 7 W, 10 W, 15 W, 18 W, 25 W, 30 W, 50 W, 60 W, 100 W, 150 W, 200 W, 250 W, 500 W, 2 kW, 3 kW, 20 kW, 50 kW, etc., or a value between any of the values.

[0046] Laser pulses may be output by the laser source 104 at a pulse repetition rate in the range of 5 kHz to 5 GHz. However, it will be appreciated that the pulse repetition rate may be made less than 5 kHz or greater than 5 GHz. Thus, laser pulses may be output by the laser source 104 at a pulse repetition rate less than, greater than, or equal to 5 kHz, 50 kHz, 100 kHz, 175 kHz, 225 kHz, 250 kHz, 275 kHz, 500 kHz, 800 kHz, 900 kHz, 1 MHz, 1.5 MHz, 1.8 MHz, 1.9 MHz, 2 MHz, 2.5 MHz, 3 MHz, 4 MHz, 5 MHz, 10 MHz, 20 MHz, 50 MHz, 60 MHz, 100 MHz, 150 MHz, 200 MHz, 250 MHz, 300 MHz, 350 MHz, 500 MHz, 550 MHz, 600 MHz, 900 MHz, 2 GHz, 10 GHz, etc., or a value between any of the values.

[0047] In addition to wavelength, average power, and (when the laser energy beam is embodied as a series of laser pulses) pulse duration and pulse repetition rate, the laser energy beam delivered to the workpiece 102 may be characterized by one or more other characteristics, such as pulse energy, peak power, etc., which may be selected (e.g., based on one or more other characteristics, such as wavelength, pulse duration, average power and pulse repetition rate, spot size, etc., as appropriate) to irradiate the workpiece 102 at a processing spot to process the workpiece 102 (e.g., to form one or more features).

[0048] Examples of laser types for the laser source 104 may be characterized as gas lasers (e.g., CO2 lasers, carbon monoxide lasers, excimer lasers, etc.), solid state lasers (e.g., Nd:YAG lasers, etc.), rod lasers, fiber lasers, photonic crystal rod / fiber lasers, passively mode-locked solid state bulk or fiber lasers, dye lasers, mode-locked diode lasers, pulsed lasers (e.g., ms, ns, ps, fs pulsed lasers), CW lasers, QCW lasers, or the like, or any combination thereof. Depending on the configuration of the plurality of lasers, a gas laser (e.g., CO2 laser, etc.) may be configured to operate in one or more modes (e.g., in CW mode, QCW mode, pulsed mode, or any combination thereof). Specific examples of laser sources that may be provided as laser source 104 include one or more laser sources such as: a BOREAS, HEGOA, SIROCCO, or CHINOOK series laser manufactured by EOLITE; a PYROFLEX series laser manufactured by PYROPHOTONICS; a PALADIN Advanced 355, DIAMOND series (e.g., DIAMOND E, G, J-2, J-3, J-5 series), FLARE NX, MATRIX QSDPSS, MEPHISTOQ, AVIA LX, AVIA NX, RAPID NX, HYPERRAPID NX, RAPID, HELIOS, FIDELITY, MONACO, OPERA, or RAPID FX series laser manufactured by COHERENT; a laser source such as a VIZIONE, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX, a VIZIONE NX ASCEND, EXCELSIOR, EXPLORER, FEMTOTRAIN, HIGHQ-2, HIPPO, ICEFYRE, NAVIGATOR, QUANTA-RAY, QUASAR, SOLSTICS ACE, SPIRIT, TALON, VANGUARD, or VGEN series lasers manufactured by PHYSICS; PULSTAR or FIRESTAR series lasers manufactured by SYNRAD; TRUFLOW series lasers (e.g., TRUFLOW 2000, 2600, 3000, 3200, 3600, 4000, 5000, 6000, 6000, 8000, 10000, 12000, 15000, 20000), TRUCOAX series lasers (e.g., TRUCOAX 1000) or TRUDISK, TRUPULSE, TRUDIODE, TRUFIBER or TRUMICRO series lasers, all manufactured by TRUMPF; FCP APJEWEL or FEMTOLITE series lasers manufactured by IMRA AMERICA;TANGERINE and SATSUMA series lasers manufactured by AMPLITUDE SYSTEMES (and MIKAN and T oscillators); CL, CLPF, CLPN, CLPNT, CLT, ELM, ELPF, ELPN, ELPP, ELR, ELS, FLPN, FLPNT, FLT, GLPF, GLPN, GLR, HLPN, HLPP, RFL, TLM, TLPN, TLR, ULPN, ULR, ULM, VLM, VLPN, YLM, YLPF, YLPN, YLPP, YLR, YLS, FLPM, FLPMT, DLM, BLM or DLR series lasers manufactured by IPG PHOTONICS (e.g., including GPLN-532-100, GPLN-532-200, GPLN-532-500, ULR / ULM ULM 355-200, etc.), etc., or any combination thereof. ;

[0049] B. First locator

[0050] In general, the first positioner 106 is operable to impart movement of the beam axis relative to the workpiece 102 along an X axis (or direction), a Y axis (or direction), or a combination thereof (e.g., by deflecting the beam path 114 within the first primary angular range 116). Although not illustrated, the Y axis (or Y direction) is understood to refer to an axis (or direction) orthogonal to the illustrated X and Z axes (or directions).

[0051] Movement of the beam axis relative to the workpiece 102 is generally limited when imparted by the first positioner 106 so that the processing spot can be scanned, moved, or otherwise positioned within the first scan field projected by the scan lens 112. Generally speaking, and depending on one or more factors such as the configuration of the first positioner 106, the position of the first positioner 106 along the beam path 114, the beam size of the laser energy beam incident on the first positioner 106, the spot size, etc., the first scan field can extend in either the X or Y direction to a distance less than, greater than, or equal to 0.01 mm, 0.04 mm, 0.1 mm, 0.5 mm, 1.0 mm, 1.4 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.2 mm, 5 mm, 10 mm, 25 mm, 50 mm, 60 mm, etc., or between any of the values. As used herein, the term "beam size" refers to the diameter or width of the laser energy beam and can be measured as 1 / e of the optical intensity at the beam axis from the beam axis to the optical intensity drop to the propagation axis along the beam path 114. 2The maximum dimension of the first scanning field (e.g., in a plane containing the X-axis and the Y-axis (referred to herein as the "XY plane")) can be greater than, equal to, or less than the maximum dimension of a feature (e.g., an opening, a recess, a through hole, a trench, etc.) to be formed in the workpiece 102 (as measured in the XY plane).

[0052] In general, the first positioner 106 is provided as an AO deflector (AOD) system that includes one or more AODs having AO cells formed of materials such as: crystalline germanium (Ge), gallium arsenide (GaAs), molybdenum lead ore (PbMoO4), tellurium dioxide (TeO2), crystalline quartz, glassy SiO 2、 Arsenic trisulfide (As2S3), lithium niobate (LiNbO3), etc., or any combination thereof. In a specific example, the AOD system includes at least one (e.g., one, two, three, four, five, six, etc.) single-element AOD, at least one (e.g., one, two, three, four, five, six, etc.) multi-element AOD, etc., or any combination thereof. An AOD system that includes only one AOD is referred to herein as a "single-cell AOD system", and an AOD system that includes more than one AOD is referred to herein as a "multi-cell AOD system". As used herein, a "single-element" AOD refers to an AOD that has only one ultrasonic transducer element acoustically coupled to an AO unit, while a "multi-element" AOD includes at least two ultrasonic transducer elements acoustically coupled to a common AO unit. The AOD system may be provided as a single-axis AOD system (e.g., operable to deflect the beam axis along a single axis) or as a multi-axis AOD system (e.g., operable to deflect the beam axis along one or more axes, such as along the X-axis, along the Y-axis, or any combination thereof) by deflecting the beam path 114 in a corresponding manner. In general, the multi-axis AOD system may be provided as a single-unit or multi-unit AOD system. A multi-unit multi-axis AOD system typically includes a plurality of AODs, each of which is operable to deflect the beam axis along a different axis. For example, a multi-unit multi-axis system may include a first AOD (e.g., a single element or a multi-element AOD system) operable to deflect the beam axis along one axis (e.g., along the X-axis), and a second AOD (e.g., a single element or a multi-element AOD) operable to deflect the beam axis along a second axis (e.g., along the Y-axis). A single-unit multi-axis system typically includes a single AOD operable to deflect the beam axis along two axes (e.g., along the X and Y axes). For example, a single-unit multi-axis system may include at least two ultrasonic transducer elements acoustically coupled to orthogonal configuration planes, facets, sides, etc. of a common AO unit.

[0053] As will be appreciated by those of ordinary skill in the art, AO technology (e.g., AOD, AOM, etc.) utilizes the diffraction effect produced by one or more acoustic waves that propagate through the AO unit (i.e., along the "diffraction axis" of the AOD) to diffract an incident light wave (i.e., in the context of the present application, a laser energy beam) while propagating through the AO unit (i.e., along the "optical axis" within the AOD). The incident laser energy beam is diffracted to produce a diffraction pattern that typically includes zero-order and first-order diffraction peaks, and may also include other higher-order diffraction peaks (e.g., second-order, third-order, etc.). As is known in the art, the portion of the diffracted beam of laser light that is in the zero-order diffraction peak is referred to as the "zero-order" beam, the portion of the diffracted beam of laser light that is in the first-order diffraction peak is referred to as the "first-order" beam, and so on. In general, the zero-order beam and other diffracted order beams (e.g., first-order beam, etc.) propagate along different beam paths after exiting the AO unit (e.g., passing through the optical output side of the AO unit). For example, a zero-order beam propagates along a zero-order beam path, a first-order beam propagates along a first-order beam path, and so on.

[0054] Acoustic waves are typically emitted into the AO unit by applying an RF drive signal (e.g., from one or more drivers of the first positioner 106) to the ultrasonic transducer element. Characteristics of the RF drive signal (e.g., amplitude, frequency, phase, etc.) may be controlled (e.g., based on one or more control signals output by the controller 122, a component-specific controller, or the like, or any combination thereof) to adjust the manner in which incident light waves are diffracted. For example, the frequency of the applied RF drive signal will determine the angle at which the beam path 114 is deflected. As is known in the art, the angle θ at which the beam path 114 is deflected may be calculated as follows:

[0055]

[0056] Where λ is the optical wavelength of the laser energy beam (measured in nm), f is the frequency of the applied RF drive signal (measured in Hz), and v is the speed of the acoustic wave in the AO unit (measured in m / s). If the frequency of the applied RF drive signal is composed of multiple frequencies, the beam path 114 will be deflected by multiple angles simultaneously.

[0057] The first-order beam path exiting the AO unit can typically be considered as the beam path 114 that has been rotated or deflected within the AO unit. Unless otherwise explicitly stated herein, the beam path 114 exiting the AO unit corresponds to the first-order beam path. When the AOD is operated or driven to diffract an incident laser energy beam, the axis (also referred to herein as the "rotation axis") about which the beam path 114 exiting the AO unit is rotated (e.g., relative to the beam path 114 when incident on the AO unit) is orthogonal to both the diffraction axis of the AO unit and the optical axis along which the incident laser energy beam propagates within the AO unit. Therefore, the AOD deflects the incident beam path 114 in a plane (also referred to herein as the "deflection plane") containing (or otherwise substantially parallel to) the diffraction axis of the AO unit and the optical axis within the AO unit. The spatial range across which the AOD can deflect the beam path 114 in the deflection plane is referred to herein as the "scanning field" of that AOD. Therefore, the first scanning field of the first positioner 106 can be considered to correspond to the scanning field of a single AOD (for example, when the first positioner 106 includes a single AOD), or to the combined scanning field of multiple AODs (for example, when the first positioner 106 includes multiple AODs).

[0058] The first positioner 106 may be characterized as having a "first positioning rate", which refers to the rate at which the first positioner 106 positions the processing spot at any location within the first scan field (thus moving the beam axis). For example, the first positioning rate may be greater than, equal to, or less than 8kHz, 10kHz, 20kHz, 30kHz, 40kHz, 50kHz, 75kHz, 80kHz, 100kHz, 250kHz, 500kHz, 750kHz, 1MHz, 5MHz, 10MHz, 20MHz, 40MHz, 50MHz, 75MHz, 100MHz, 125MHz, 150MHz, 175MHz, 200MHz, 225MHz, 250MHz, etc., or between any of the values. This range is also referred to herein as the first positioning bandwidth. During operation of the first positioner 106, the RF drive signal is repeatedly applied to one or more ultrasonic transducers of the first positioner 106, and the first positioning bandwidth corresponds to (e.g., is equal to, or at least substantially equal to) the rate at which the RF drive signal is applied. The rate at which the drive signal is applied is also referred to as the "update rate" or "refresh rate." The inverse of the first positioning rate is referred to herein as the "first positioning period," and thus refers to the minimum amount of time that passes before the position of the processing spot changes from one position within the first scan field to another position within the first scan field. Therefore, the first locator 106 may be characterized as having a first positioning period greater than, equal to, or less than 200μs, 125μs, 100μs, 50μs, 33μs, 25μs, 20μs, 15μs, 13.3μs, 12.5μs, 10μs, 4μs, 2μs, 1.3μs, 1μs, 0.2μs, 0.1μs, 0.05μs, 0.025μs, 0.02μs, 0.013μs, 0.01μs, 0.008μs, 0.0067μs, 0.0057μs, 0.0044μs, 0.004μs, etc., or between any of the values.

[0059] It will be appreciated that the material from which the AO unit is formed will depend on the wavelength of the laser energy propagating along the beam path 114 so as to be incident on the AO unit. For example, materials such as crystalline germanium may be used, wherein the wavelength of the laser energy to be deflected is in the range of 2 μm (or around 2 μm) to 20 μm (or around 20 μm), materials such as gallium arsenide and arsenic trisulfide may be used, wherein the wavelength of the laser energy beam to be deflected is in the range of 1 μm (or around 1 μm) to 11 μm (or around 11 μm), and materials such as glassy SiO2, quartz, lithium niobate, wulfenite, and tellurium dioxide may be used, wherein the wavelength of the laser energy to be deflected is in the range of 200 nm (or around 200 nm) to 5 μm (or around 5 μm).

[0060] When the laser energy beam output by the laser source 104 is embodied as a series of laser pulses, the first positioner 106 can be operated to deflect the beam path 114 to different angles within the main angle range 116. In one embodiment, the first positioning period is greater than or equal to the pulse duration of each of the laser pulses. Therefore, when the AOD is driven at a fixed RF drive frequency (or a set of fixed RF drive frequencies), the laser pulses can pass through the AO unit of the AOD. Maintaining the fixed RF drive frequency (or a set of fixed RF drive frequencies) applied to the AOD as the laser pulses pass through the AO unit of the AOD generally results in uniform deflection of the laser pulses throughout the entire pulse duration of the laser pulses, and therefore may also be referred to as "full pulse deflection". However, in another embodiment, the first positioning period may be less than the pulse duration of the laser pulse; therefore, the laser pulses can pass through the AO unit of the AOD when the RF drive frequency (or a frequency within a set of RF drive frequencies) changes. Changing the RF drive frequency applied to the AOD as the laser pulse passes through the AO unit of the AOD can result in temporal division of the laser pulse, and thus may also be referred to as "partial pulse deflection" or "pulse slicing". Certain aspects of pulse slicing are described in more detail below. Although pulse slicing techniques are described herein as being applied to temporal division of laser pulses, it will be appreciated that the techniques may be equally applicable to temporal division of a laser energy beam embodied as a continuous or quasi-continuous laser beam.

[0061] C. Second locator

[0062] Generally speaking, the second positioner 108 is operable to impart movement of the beam axis relative to the workpiece 102 along the X-axis (or direction), the Y-axis (or direction), or a combination thereof (e.g., by deflecting the beam path 114 within the first auxiliary angular range 118a or within the second auxiliary angular range 118b).

[0063] Movement of the beam axis as imparted by the second positioner 108 relative to the workpiece 102 is generally restricted so that the processing spot can be scanned, moved, or otherwise positioned within the second scan field projected by the scan lens 112. Generally speaking, and depending on one or more factors such as the configuration of the second positioner 108, the position of the second positioner 108 along the beam path 114, the beam size of the laser energy beam incident on the second positioner 108, the spot size, etc., the second scan field can extend in either the X or Y direction to a distance greater than the corresponding distance of the first scan field. In view of the above, the second scan field can extend in either the X or Y direction to a distance less than, greater than, or equal to 1 mm, 25 mm, 50 mm, 75 mm, 100 mm, 250 mm, 500 mm, 750 mm, 1 cm, 25 cm, 50 cm, 75 cm, 1 m, 1.25 m, 1.5 m, etc., or between any of the values. The maximum dimension of the second scanning field (e.g., in the XY plane) may be greater than, equal to, or less than the maximum dimension (as measured in the XY plane) of a feature (e.g., an opening, a recess, a via, a groove, a cutting path, a conductive trace, etc.) to be formed in the workpiece 102.

[0064] In view of the configurations described herein, it will be appreciated that the movement of the beam axis imparted by the first positioner 106 may be superimposed with the movement of the beam axis imparted by the second positioner 108. Thus, the second positioner 108 may be operable to scan the first scan field within the second scan field.

[0065] In general, the positioning rate at which the second positioner 108 is capable of positioning the processing spot at any position within the second scanning field (thus moving the beam axis within the second scanning field and / or scanning the first scanning field within the second scanning field) spans a range less than the first positioning bandwidth (also referred to herein as the "second positioning bandwidth"). In one specific example, the second positioning bandwidth is in the range of 500 Hz (or around 500 Hz) to 8 kHz (or around 8 kHz). For example, the second positioning bandwidth may be greater than, equal to, or less than 500 Hz, 750 Hz, 1 KHz, 1.25 KHz, 1.5 KHz, 1.75 KHz, 2 KHz, 2.5 KHz, 3 KHz, 3.5 KHz, 4 KHz, 4.5 KHz, 5 KHz, 5.5 KHz, 6 KHz, 6.5 KHz, 7 KHz, 7.5 KHz, 8 KHz, etc., or between any of the values.

[0066] In one embodiment, the second positioner 108 may be provided as a galvanometer mirror system including two galvanometer mirror components, namely, a first galvanometer mirror component configured to impart movement of the beam axis relative to the workpiece 102 along the X-axis (e.g., an X-axis galvanometer mirror component), and a second galvanometer mirror component configured to impart movement of the beam axis relative to the workpiece 102 along the Y-axis (e.g., a Y-axis galvanometer mirror component). However, in another embodiment, the second positioner 108 may be provided as a galvanometer mirror system including only a single galvanometer mirror component configured to impart movement of the beam axis relative to the workpiece 102 along both the X-axis and the Y-axis. In still other embodiments, the second positioner 108 may be provided as a rotating polygon mirror system, etc. It should therefore be appreciated that, depending on the particular configuration of the second positioner 108 and the first positioner 106, the second positioning bandwidth may be greater than or equal to the first positioning bandwidth.

[0067] D. The third locator

[0068] The third positioner 110 is operable to impart movement of the workpiece 102 (e.g., workpieces 102a and 102b) relative to the scan lens 112, and thus to impart movement of the workpiece 102 relative to the beam axis. The movement of the workpiece 102 relative to the beam axis is generally limited so that the processing spot can be scanned, moved, or otherwise positioned within the third scan field. Depending on one or more factors such as the configuration of the third positioner 110, the third scan field may extend to a distance greater than or equal to the corresponding distance of the second scan field in the X direction, the Y direction, or any combination thereof. However, in general, the maximum dimension of the third scan field (e.g., in the XY plane) will be greater than or equal to the corresponding maximum dimension of any feature to be formed in the workpiece 102 (as measured in the XY plane). Optionally, the third positioner 110 is operable to move the workpiece 102 relative to the beam axis within a scan field that extends in the Z direction (e.g., in a range between 1 mm and 50 mm). Thus, the third scan field may extend along the X, Y, and / or Z directions.

[0069] In view of the configurations described herein, it should be appreciated that movement of the processing spot relative to the workpiece 102 (e.g., as imparted by the first positioner 106 and / or the second positioner 108) may overlap with movement of the workpiece 102 as imparted by the third positioner 110. Thus, the third positioner 110 may be operable to scan the first scanning field and / or the second scanning field within the third scanning field. In general, the third positioner 110 is capable of positioning the workpiece 102 at any location within the third scanning field (thereby moving the workpiece 102, scanning the first scanning field within the third scanning field, and / or scanning the second scanning field within the third scanning field) at a positioning rate that spans a range that is less than the second positioning bandwidth (also referred to herein as the "third positioning bandwidth"). In one specific example, the third positioning bandwidth is less than 500 Hz (or about 500 Hz). For example, the third positioning bandwidth may be equal to or less than 500 Hz, 250 Hz, 150 Hz, 100 Hz, 75 Hz, 50 Hz, 25 Hz, 10 Hz, 7.5 Hz, 5 Hz, 2.5 Hz, 2 Hz, 1.5 Hz, 1 Hz, etc., or between any of the values.

[0070] In one embodiment, the third positioner 110 is provided as one or more linear platforms (e.g., each capable of imparting translational movement of the workpiece 102 along the X, Y, and / or Z directions), one or more rotational platforms (e.g., each capable of imparting rotational movement of the workpiece 102 about an axis parallel to the X, Y, and / or Z directions), or the like or any combination thereof. In one embodiment, the third positioner 110 includes an X-platform for moving the workpiece 102 along the X direction, and a Y-platform supported by the X-platform (and thus movable along the X direction by the X-platform) for moving the workpiece 102 along the Y direction.

[0071] As described so far, the apparatus 100 may use a so-called "stacked" positioning system as the third positioner 110 that enables the workpiece 102 to move while the positions of other components, such as the first positioner 106, the second positioner 108, the scan lens 112, etc., remain stationary relative to the workpiece 102 within the apparatus 100 (e.g., via one or more supports, frames, etc., as known in the art). In another embodiment, the third positioner 110 may be configured and operable to move one or more components, such as the first positioner 106, the second positioner 108, the scan lens 112, or the like, or any combination thereof, and the workpiece 102 may remain stationary.

[0072] In yet another embodiment, the third positioner 110 may be provided as a so-called "split-axis" positioning system, in which one or more components such as the first positioner 106, the second positioner 108, the scan lens 112, or the like, or any combination thereof, are carried by one or more linear or rotary stages (e.g., mounted on a frame, gantry, etc.) and the workpiece 102 is carried by one or more other linear or rotary stages. In such embodiments, the third positioner 110 includes one or more linear or rotary stages configured and operable to move one or more components such as a scan head (e.g., including the second positioner 108 and the scan lens 112), and one or more linear or rotary stages configured and operable to move the workpiece 102. For example, the third positioner 110 may include a Y stage for imparting movement to the workpiece 102 in the Y direction and an X stage for imparting movement to the scan head in the X direction. Some examples of split-axis positioning systems that may be beneficially or advantageously used in device 100 include any of the systems disclosed in: U.S. Patent Nos. 5,751,585, 5,798,927, 5,847,960, 6,606,999, 7,605,343, 8,680,430, 8,847,113, or U.S. Patent Application Publication No. 2014 / 0083983, or any combination thereof, each of which is incorporated herein by reference in its entirety.

[0073] In one embodiment where the third positioner 110 includes a Z stage, the Z stage may be configured and arranged to move the workpiece 102 in the Z direction. In this case, the Z stage may be carried by one or more of the other aforementioned stages for moving or positioning the workpiece 102, may carry one or more of the other aforementioned stages for moving or positioning the workpiece 102, or any combination thereof. In another embodiment where the third positioner 110 includes a Z stage, the Z stage may be configured and arranged to move the scan head in the Z direction. Thus, where the third positioner 110 is provided as a separate stage positioning system, the Z stage may carry or be carried by the X stage. Moving the workpiece 102 or the scan head in the Z direction may result in a change in the spot size at the workpiece 102.

[0074] In yet another embodiment, one or more components such as the first positioner 106, the second positioner 108, the scan lens 112, etc. may be carried by an articulated multi-axis robotic arm (e.g., a 2-axis, 3-axis, 4-axis, 5-axis, or 6-axis arm). In this embodiment, the second positioner 108 and / or the scan lens 112 may be carried by the end effector of the robotic arm as appropriate. In yet another embodiment, the workpiece 102 may be carried directly on the end effector of the articulated multi-axis robotic arm (i.e., without the third positioner 110). In yet another embodiment, the third positioner 110 may be carried on the end effector of the articulated multi-axis robotic arm.

[0075] D. Scanning lens

[0076] The scan lens 112 (e.g., provided as a simple lens or a compound lens) is generally configured to focus the laser energy beam directed along the beam path, typically so as to produce a beam waist that can be positioned at or near the desired processing spot. The scan lens 112 can be provided as an f-theta lens (as shown), a telecentric f-theta lens, an axicon lens (in which case a series of beam waists are produced, resulting in multiple processing spots displaced from each other along the beam axis), or the like or any combination thereof.

[0077] In one embodiment, the scan lens 112 is provided as a fixed focal length lens and is coupled to a scan lens positioner (e.g., a lens actuator, not shown) operable to move the scan lens 112 (e.g., so as to change the position of the beam waist along the beam axis). For example, the lens actuator may be provided as a voice coil operable to linearly translate the scan lens 112 in the Z direction. In this case, the scan lens 112 may be formed of materials such as fused silica, optical glass, zinc selenide, zinc sulfide, germanium, gallium arsenide, magnesium fluoride, etc. In another embodiment, the scan lens 112 is provided as a variable focal length lens (e.g., a zoom lens, or a so-called "liquid lens" incorporating technology currently provided by COGNEX, VARIOPTIC, etc.) that can be actuated (e.g., via a lens actuator) to change the position of the beam waist along the beam axis. Changing the position of the beam waist along the beam axis may result in a change in the spot size at the workpiece 102.

[0078] In an embodiment where the apparatus 100 includes a lens actuator, the lens actuator can be coupled to the scan lens 112 (e.g., to enable movement of the scan lens 112 within the scan head relative to the second positioner 108). Alternatively, the lens actuator can be coupled to the scan head 120 (e.g., to enable movement of the scan head itself, in which case the scan lens 112 and the second positioner 108 will move together). In another embodiment, the scan lens 112 and the second positioner 108 are integrated into different housings (e.g., so that the housing in which the scan lens 112 is integrated can move relative to the housing in which the second positioner 108 is integrated).

[0079] F. Controller

[0080] In general, the device 100 includes one or more controllers, such as the controller 122, to control or facilitate the control of the operation of the device 100. In one embodiment, the controller 122 is communicatively coupled to one or more components of the device 100, such as the laser source 104, the first positioner 106, the second positioner 108, the third positioner 110, the lens actuator, the scan lens 112 (when provided as a variable focus lens), etc. (e.g., via one or more wired or wireless, serial or parallel communication links, such as USB, RS-232, Ethernet, Firewire, Wi-Fi, RFID, NFC, Bluetooth, Li-Fi, SERCOS, MARCO, EtherCAT, or the like or any combination thereof), and the one or more components can thus operate in response to one or more control signals output by the controller 122.

[0081] For example, the controller 122 may control the operation of the first positioner 106, the second positioner 108, or the third positioner 110, or any combination thereof, to impart relative movement between the beam axis and the workpiece so as to cause relative movement between the processing spot and the workpiece 102 along a path or trajectory (also referred to herein as a “process trajectory”) within the workpiece 102. It will be appreciated that any two of the positioners or all three of the positioners may be controlled such that two positioners (e.g., the first positioner 106 and the second positioner 108, the first positioner 106 and the third positioner 110, or the second positioner 108 and the third positioner 110) or all three positioners simultaneously impart relative movement between the processing spot and the workpiece 102 (thereby imparting “compound relative movement” between the beam axis and the workpiece). Of course, at any time, it is possible to control only one positioner (e.g., the first positioner 106, the second positioner 108, or the third positioner 110) to impart relative movement between the processing light spot and the workpiece 102 (thereby imparting "non-compound relative movement" between the beam axis and the workpiece).

[0082] In one embodiment, the controller 122 can control the operation of the first positioner 106 to deflect the beam path 114 within the primary angular range 116 in a manner that imparts a compound relative motion (e.g., coordinated with the second positioner 108, coordinated with the third positioner 110, or any combination thereof) or a non-compound relative motion between the beam axis and each workpiece 102 to cause relative motion between the processing spot and the workpiece 102 along a process trajectory within the workpiece 102. In another embodiment, the controller 122 can control the operation of the first positioner 106 to deflect the beam path 114 within each primary angular range 116 in a manner that compensates for tracking errors introduced by the second positioner 108.

[0083] Some other examples of operations that may be controlled to be performed by one or more of the aforementioned components include any operations, functions, processes, methods, etc., as disclosed in the aforementioned U.S. Patent Nos. 5,751,585, 5,847,960, 6,606,999, 8,680,430, 8,847,113, or as disclosed in U.S. Patent Nos. 4,912,487, 5,633,747, 5,638,267, 5,917,300, No. 6,314,463, No. 6,430,465, No. 6,600,600, No. 6,606,998, No. 6,816,294, No. 6,947,454, No. 7,019,891, No. 7,027,199, No. 7,133,182, No. 7,133,186, No. 7,133,187, No. 7,133,188, No. 7,244,906, No. 7,245,412 No. 7,259,354, No. 7,611,745, No. 7,834,293, No. 8,026,158, No. 8,076,605, No. 8,288,679, No. 8,404,998, No. 8,497,450, No. 8,648,277, No. 8,896,909, No. 8,928,853, No. 9,259,802, or disclosed in U.S. Patent Application Publication No. 2014 / 0026351, 2014 / 0196140, 2014 / 0263201, 2014 / 0263212, 2014 / 0263223, 2014 / 0312013, or in German Patent No. DE102013201968B4, or in International Patent Publication No. WO2009 / 087392, each of which is incorporated herein by reference in its entirety. In another example, the controller 122 may control the operation of any positioner (e.g., in some embodiments, the first positioner 106, the second positioner 108, or a combination thereof) including one or more AODs to change the spot shape or spot size of the laser energy beam delivered to the processing spot (e.g., by chirping the RF signal applied to one or more ultrasonic transducer elements of the one or more AODs, by applying a spectrally shaped RF signal to one or more ultrasonic transducer elements of the one or more AODs, or the like or any combination thereof), as disclosed, for example, in International Patent Publication No. WO2017 / 044646A1, which is incorporated herein by reference in its entirety. The applied RF signal may be chirped linearly or nonlinearly in any desired or suitable manner. For example, the applied RF signal may be chirped at a first rate and then at a second rate to diffract the laser energy beam to deliver the AO unit in two different ways.In this case, the first rate may be slower or faster than the second rate.

[0084] In general, the controller 122 includes one or more processors operable to generate the aforementioned control signals after executing instructions. The processor may be provided as a programmable processor operable to execute instructions (e.g., including one or more general-purpose computer processors, microprocessors, digital signal processors, or the like, or any combination thereof). The instructions executable by the processor may be implemented as software, firmware, etc., or as any suitable form of circuit system, including a programmable logic device (PLD), a field-programmable gate array (FPGA), a field-programmable object array (FPOA), an application-specific integrated circuit (ASIC) - including digital, analog, and mixed analog / digital circuit systems, or the like or any combination thereof. The execution of instructions may be performed on one processor, distributed among multiple processors, performed in parallel across processors within a device or across a network of devices, or the like or any combination thereof.

[0085] In one embodiment, the controller 122 includes a tangible medium such as a computer memory that can be accessed by the processor (e.g., via one or more wired or wireless communication links). As used herein, "computer memory" includes magnetic media (e.g., tapes, hard drives, etc.), optical disks, volatile or non-volatile semiconductor memories (e.g., RAM, ROM, NAND flash, NOR flash, SONOS memory, etc.), etc., and can be accessed locally, remotely (e.g., across a network), or a combination thereof. In general, instructions can be stored as computer software (e.g., executable code, files, instructions, etc., library files, etc.) that can be easily authorized by a technician based on the description provided herein, for example, written in C, C++, Visual Basic, Java, Python, Tel, Perl, Scheme, Ruby, assembly language, hardware description language (e.g., VHDL, VERILOG, etc.), etc. Computer software is typically stored in one or more data structures transmitted by computer memory.

[0086] Although not shown, one or more drivers (e.g., RF drivers, servo drivers, line drivers, power supplies, etc.) may be communicatively coupled to inputs of one or more components for controlling the components, such as the laser source 104, the first positioner 106, the second positioner 108, the third positioner 110, the lens actuator, the scan lens 112 (when provided as a variable focus lens), etc. Thus, one or more components such as the laser source 104, the first positioner 106, the second positioner 108, the third positioner 110, the lens actuator, the scan lens 112 (when provided as a variable focus lens), etc. may be considered to also include any suitable drivers, as known in the art. Each of the drivers will typically include an input communicatively coupled to the controller 122, and the controller 122 may be operable to generate one or more control signals (e.g., trigger signals, etc.), which may be transmitted to one or more drivers associated with one or more components of the apparatus 100. Components such as the laser source 104 , the first positioner 106 , the second positioner 108 , the third positioner 110 , the lens actuator, the scan lens 112 (when provided as a variable focus lens), etc. are therefore responsive to control signals generated by the controller 122 .

[0087] Although not shown, one or more additional controllers (e.g., component-specific controllers) may optionally be communicatively coupled to an input of a driver that is communicatively coupled to (and therefore associated with) a component such as the laser source 104, the first positioner 106, the second positioner 108, the third positioner 110, the lens actuator, the scan lens 112 (when provided as a variable focus lens), etc. In this embodiment, each component-specific controller may be communicatively coupled to the controller 122 and may be operable to generate one or more control signals (e.g., trigger signals, etc.) in response to one or more control signals received from the controller 122, which may then be transmitted to an input of the driver to which the controller is communicatively coupled. In this embodiment, the component-specific controllers may operate in a manner similar to that described with respect to the controller 122.

[0088] In another embodiment providing one or more component-specific controllers, a component-specific controller associated with one component (e.g., laser source 104) can be communicatively coupled to a component-specific controller associated with one component (e.g., first positioner 106, etc.) In this embodiment, one or more of the component-specific controllers can be operable to generate one or more control signals (e.g., trigger signals, etc.) in response to one or more control signals received from one or more other component-specific controllers.

[0089] III. Additional Discussion on Multi-Axis AOD Systems

[0090] In many of the specific examples discussed herein, the first positioner 106 is provided as a multi-axis AOD system. Depending on the configuration of the AOD within the AOD system, the AOD may be characterized as a longitudinal mode AOD or a shear mode AOD, and may be operable to diffract a linearly polarized or circularly polarized laser energy beam. Thus, depending on the wavelength of the laser energy beam and the material forming the AO unit of the AOD in the AOD system, the AOD may be oriented such that the diffraction axis of the AO unit in the AOD is parallel or perpendicular to (or at least substantially parallel or perpendicular to) the polarization plane of the laser energy beam incident into the AO. For example, if the wavelength of the laser energy beam is in the ultraviolet or visible green range of the electromagnetic spectrum and the AO unit of the AOD is formed of a material such as quartz, the AOD may be oriented such that the diffraction axis of the AO unit is perpendicular to (or at least substantially perpendicular to) the polarization plane of the laser energy beam incident into the AO unit. In another example, if the wavelength of the laser energy beam is within the so-called mid-wavelength or long-wavelength infrared range of the electromagnetic spectrum (i.e., wavelengths spanning the range of 3 μm (or around 3 μm) to 15 μm (or around 15 μm)) and the AO unit of the AOD is formed of a material such as crystalline germanium, the AOD can be oriented so that the diffraction axis of the AO unit is parallel to (or at least substantially parallel to) the polarization plane of the laser energy beam incident into the AO unit.

[0091] refer to Figure 2 , the multi-axis AOD system can be provided as a multi-unit multi-axis AOD system 200 including a first AOD 202 and a second AOD 204. Both the first AOD 202 and the second AOD 204 can be provided in any manner as described above. The first AOD 202 is configured and operable to rotate an incident laser energy beam (e.g., propagating along the beam path 114) about a first rotation axis at any angle within a first angular range (also referred to herein as a "first AOD angular range 206") (e.g., as measured relative to the beam path 114 incident on the first AOD 202) so as to transmit a first-order beam propagating along the deflected beam path 114. Similarly, the second AOD 204 is configured and operable to rotate an incident laser energy beam transmitted by the first AOD 202 about a second rotation axis at any angle within a second angular range (also referred to herein as the "second AOD angular range 208") (e.g., as measured relative to the beam path 114' incident on the second AOD 204) so ​​as to transmit a first-order beam propagating along a deflected beam path 114". As will be appreciated, each of the beam paths 114' and 114" represents a specific instance of a path along which a laser energy beam may propagate; therefore, each of the beam paths 114' and 114" may also be generally referred to herein as a "beam path 114".

[0092] Generally speaking, the second AOD 204 is oriented relative to the first AOD 202 so that the second rotation axis is different from the first rotation axis. For example, the second rotation axis may be orthogonal to the first rotation axis or tilted relative to the first rotation axis. In view of the fact that the diffraction axis of the AOD is orthogonal to the rotation axis of the AOD, the diffraction axis of the second AOD 204 (also referred to as the "second diffraction axis") may therefore be orthogonal or tilted relative to the diffraction axis of the first AOD 202 (also referred to as the "first diffraction axis"). However, in another specific example, the second AOD 204 is oriented relative to the first AOD 202 so that the second rotation axis is parallel to (or at least substantially parallel to) the first rotation axis. In this case, one or more optical components may be configured in the beam path 114' to rotate the deflection plane of the first AOD 202 (e.g., 90 degrees or above) so that when projected onto the second AOD 204, the deflection plane of the first AOD 202 is rotated relative to the orientation of the deflection plane of the second AOD 204 (e.g., 90 degrees or above), and the second diffraction axis may be parallel to (or at least substantially parallel to) the first diffraction axis. For examples of how the deflection plane can be rotated (as discussed above), see, for example, International Publication No. WO 2019 / 060590 A1. When the deflection plane of the first AOD 202 is rotated in the manner described above, when projected onto the second AOD 204, the first diffraction axis is rotated relative to the orientation of the second diffraction axis (e.g., 90 degrees or above).

[0093] In general, the AO cells in the first AOD 202 are formed of a material that can be the same or different than the AO cells in the second AOD 204. Additionally, the type of acoustic wave used by the first AOD 202 to deflect the incident laser energy beam (i.e., shear mode or longitudinal mode) can be the same or different than the type of acoustic wave used by the second AOD 204 to deflect the incident laser energy beam.

[0094] It will be appreciated that the AOD system 200 may be operated at any time such that only the first AOD 202 produces a first-order beam, only the second AOD 204 produces a first-order beam, or both the first AOD 202 and the second AOD 204 produce a first-order beam. Thus, the deflection of the beam path 114 produced by the first positioner 106 may be considered to be caused only by the deflection obtained from the beam path 114', only by the deflection obtained from the beam path 114", or by the superposition of the deflections obtained from the beam paths 114' and 114". Similarly, the main angular range 116 may be considered only as the first AOD angular range 206, only as the second AOD angular range 208, or as the superposition of the first AOD angular range 206 and the second AOD angular range 208. When the first positioner 106 is provided as an AOD system (such as, AOD system 200), the first positioner 106 may optionally include one or more other additional optical components, such as a beam dump, a beam expander, a beam shaper, an aperture, a filter, a collimator, a lens, a mirror, a phase retarder, a polarizer, or the like, or any combination thereof.

[0095] IV. Discussion on Diffraction Efficiency in AOD Systems

[0096] As used herein, the term "diffraction efficiency" refers to the proportion of energy in a laser energy beam incident on an AOD that is diffracted into a first-order beam within the AO unit of the AOD. The diffraction efficiency can therefore be expressed as the ratio of the optical power in the first-order beam generated by the AOD to the optical power of the incident laser energy beam incident on the AOD. In general, the amplitude of the applied RF drive signal can have a nonlinear effect on the diffraction efficiency of the AOD, and the diffraction efficiency of the AOD can also vary with the frequency of the RF drive signal applied to drive the AOD. In view of the above, and in the specific example of the AOD system 200 provided as the first positioner 106, the first RF drive signal applied to drive the first AOD 202 can be characterized as having an amplitude (also referred to as "first amplitude" herein), and the second RF drive signal applied to drive the second AOD 204 can be characterized as having an amplitude (also referred to as "second amplitude" herein).

[0097] In general, the first amplitude may be selected or otherwise set based on one or more factors, such as a first drive frequency of the first RF drive signal, a desired diffraction efficiency of the first AOD 202 to be driven by the first RF drive signal, a peak optical power of the laser energy beam to be deflected during a period when the first AOD 202 is to be driven by the first RF drive signal, an average optical power of the laser energy beam to be deflected during a period when the first AOD 202 is to be driven by the first RF drive signal, etc., or any combination thereof. Similarly, the second amplitude may be selected or otherwise set based on one or more factors, such as a second drive frequency of the second RF drive signal, a desired diffraction efficiency of the second AOD 204 to be driven by the second RF drive signal, a peak optical power of the laser energy beam to be deflected during a period when the second AOD 204 is to be driven by the second RF drive signal, an average optical power of the laser energy beam to be deflected during a period when the second AOD 204 is to be driven by the second RF drive signal, etc., or any combination thereof.

[0098] V. Specific Examples of Pulse Slicing

[0099] As discussed above, whether provided as a single-axis AOD system or a multi-axis AOD system (such as AOD system 200), the first positioner 106 can be operated to implement pulse slicing, that is, temporally dividing a common laser pulse (also referred to herein as a "mother laser pulse") into at least two laser pulses. The temporally divided portions of the common mother laser pulse are also referred to herein as "pulse segments". As will be appreciated, pulse segments can be considered a type of laser pulse.

[0100] Figure 3 illustratively illustrates a specific example of pulse slicing, in which a mother laser pulse 300 is temporally divided into two pulse segments. Specifically, during a first segment period p1, the mother laser pulse 300 is divided into a first pulse segment 300a, and during a second segment period p2, the mother laser pulse 300 is divided into a second pulse segment 300b. As will be appreciated, the pulse duration of the pulse segments generally corresponds to the duration of the segment period temporally divided from the mother laser pulse. Thus, for example, the first pulse segment 300a may be characterized as having a pulse duration equal to the first segment period p1, and the second pulse segment 300b may be characterized as having a pulse duration equal to the second segment period p2. In addition, as will be appreciated, the pulse duration of the pulse segments may correspond to (e.g., be equal to, or at least substantially equal to) the update rate of the first locator 106 during pulse slicing, an integer multiple of the update rate of the first locator 106 during pulse slicing, or a combination thereof.

[0101] The consecutive segment periods may occur continuously (i.e., where one segment period begins immediately after the previous segment period), may occur intermittently (i.e., where one segment period begins after a delay immediately after the previous segment period), or a combination thereof. Where the consecutive segment periods occur intermittently, it will be appreciated that the duration of the delay may be characterized as an integer multiple of the positioning period of the first locator 106 (where the integer may be any integer, such as 1, 2, 3, 4, 5, 10, 20, 50, 100, etc., or between any of the values). Figure 3 The specific example shown in is an example where the consecutive segment periods p1 and p2 occur intermittently. In view of the foregoing, it will be appreciated that the pulse segments output by the AOD system 200 may constitute a laser energy beam having a pulse repetition rate equal to the update rate of the AOD system 200 (when the AOD system 200 operates to implement pulse slicing) or a multiple thereof.

[0102] The total amount of time between the start of the initial segment period and the end of the last segment period to be applied to the common mother laser pulse is less than or equal to the pulse duration of the mother laser pulse (i.e., based on the full-width at half-maximum (FWHM) of the optical power of the pulse over time). The mother laser pulse can be generally characterized as having a pulse duration that is greater than the positioning period of the first positioner 106. In some specific examples, the pulse duration of the mother laser pulse is greater than, equal to, or less than 1 μs, 2 μs, 5 μs, 10 μs, 15 μs, 20 μs, 25 μs, 30 μs, 40 μs, 50 μs, 100 μs, 300 μs, 500 μs, 900 μs, 1 ms, 2 ms, 5 ms, 10 ms, 20 ms, 50 ms, 100 ms, 300 ms, 500 ms, 900 ms, 1 s, etc., or between any of the values.

[0103] In one specific example, the duration of each segment period (and therefore, the pulse duration of each pulse segment) is an integer multiple of the positioning period of the first locator 106 (e.g., where the integer is 1, 2, 3, 5, 10, etc., or between any of the values, etc.). In some embodiments, the duration of each segment period is greater than, equal to, or less than 200 μs, 125 μs, 100 μs, 50 μs, 33 μs, 25 μs, 20 μs, 13.3 μs, 12.5 μs, 10 μs, 4 μs, 2 μs, 1.3 μs, 1 μs, 0.2 μs, 0.1 μs, 0.05 μs, 0.025 μs, 0.02 μs, 0.013 μs, 0.01 μs, 0.008 μs, 0.0067 μs, 0.0057 μs, 0.0044 μs, 0.004 μs, etc., or between any of the values. In general, the duration of one or more segment periods of a mother laser pulse may be equal to or different from the duration of one or more other segment periods of the same laser pulse. For example, although Figure 3 The first segment period p1 is illustrated as being equal to the second segment period p2 , but the duration of the first segment period p1 may be greater or less than the duration of the second segment period p2 .

[0104] although Figure 3 The mother laser pulse 300 is described as being divided temporally into only two pulse segments (i.e., a first pulse segment 300a and a second pulse segment 300b), but it will be appreciated that the mother laser pulse 300 may be divided temporally into more than two pulse segments (e.g., into 3 pulse segments, 5 pulse segments, 8 pulse segments, 10 pulse segments, 25 pulse segments, 30 pulse segments, 50 pulse segments, etc., or the like or between any of the values, etc.). For example, and with reference to Figure 4 , the laser pulse 300 may be temporally divided into four pulse segments 400a, 400b, 400c, and 400d. In one specific example, the operation of the first positioner 106 is controlled so that the pulse segments within at least one pair of consecutive divided pulse segments are deflected at different angles within the main angle range 116. For example, the pulse segment 400a may be deflected within the main angle range 116 (e.g., a first angle), and then the pulse segment 400b may be deflected within the main angle range 116 (e.g., a second angle), and then the pulse segment 400c may be deflected within the main angle range 116 (e.g., a third angle), and then the pulse segment 400d may be deflected within the main angle range 116 (e.g., a fourth angle). In another specific example, the operation of the first positioner 106 is controlled so that the pulse segments within at least one pair of consecutive divided pulse segments are deflected at the same angle within the main angle range 116.

[0105] Outside of the segment period, the first positioner 106 may be operated in any manner known in the art to attenuate the incident laser energy beam such that the laser energy beam propagating along the beam path 114 (as ultimately deflected by the first positioner 106) does not have sufficient energy to process the workpiece 102. Additionally or alternatively, outside of the segment period, the first positioner 106 may be operated to deflect the beam path 114 to a beam dump, a beam dump system, the like, or any combination thereof. Additionally or alternatively, outside of the segment period, operation of the first positioner 106 may be stopped to permit transmission of the incident laser energy beam through the AOD of the first positioner 106 to a beam dump, a beam dump system, the like, or any combination thereof.

[0106] Although pulse slicing has been discussed above with respect to a single mother laser pulse (i.e., laser pulse 300), it will be appreciated that the first positioner 106 can be operated to implement pulse slicing with respect to a sequence of continuously propagating mother laser pulses. In the sequence, the consecutive mother laser pulses can be divided in time in any desired manner, and two consecutive mother laser pulses can be divided in time in the same manner or in different manners.

[0107] A. Additional Discussion on Diffraction Efficiency

[0108] During the segment period, the first positioner 106 can be operated to attenuate the incident laser energy beam such that the optical power of the pulse segment is constant over time, varies over time, or any combination thereof. For example, the AOD (e.g., the first AOD 202, the second AOD 204, or a combination thereof) can be driven to attenuate the incident laser energy beam by maintaining and / or varying the amplitude of the RF drive signal applied to the AOD during the segment period (e.g., while keeping the frequency of the applied RF drive signal constant). Thus, for example, the optical power of the first pulse segment 300a can be constant or variable over the duration of the first segment period p1. Similarly, the optical power of the second pulse segment 300b can be constant or variable over the duration of the second segment period p2.

[0109] Over successive segment periods in which a common mother laser pulse is temporally divided into a plurality of pulse segments, the first positioner 106 may be operable to attenuate (e.g., by maintaining and / or varying the amplitude of an RF drive signal applied to the AOD over successive segment periods) the incident laser energy beam so that the average optical power and / or peak optical power of both are constant or variable. Thus, for example, the average optical power or peak optical power of the first pulse segment 300a during the first segment period p1 may be greater than, equal to, or less than the average optical power or peak optical power of the second pulse segment 300b during the second segment period p2. In another example, the average optical power or peak optical power of pulse segment 400a may be greater than, equal to, or less than the average optical power or peak optical power of any one of pulse segments 400b, 400c, and 400d; the average optical power or peak optical power of pulse segment 400b may be greater than, equal to, or less than the average optical power or peak optical power of any one of pulse segments 400c and 400d; and the average optical power or peak optical power of pulse segment 400c may be greater than, equal to, or less than the average optical power or peak optical power of pulse segment 400d.

[0110] Although the above discussion relates to operating the first positioner 106 to set or change the optical power of a pulse segment (i.e., when the first positioner 106 operates to achieve partial pulse deflection), it will be understood that the first positioner 106 can be similarly operated to set or change the optical power of a deflected pulse of laser energy when the first positioner 106 operates to achieve full pulse deflection.

[0111] VI. Specific Examples of Beam Branching

[0112] although Figure 1 The laser processing apparatus 100 is described as including an embodiment of a single second positioner 108, but it will be appreciated that many embodiments disclosed herein may be applied to laser processing apparatuses including multiple (ie, two or more) second positioners 108. For example, and with reference to Fig.31, the laser processing equipment 3100 can be provided in the same manner as the aforementioned laser processing equipment 100, but may include multiple second positioners (e.g., second positioners 108a and 108b, each collectively referred to as a "second positioner 108") and multiple scanning lenses (e.g., scanning lenses 112a and 112b, each collectively referred to as a "scanning lens 112"). As with the laser processing equipment 100, the scanning lens 112 and the corresponding second positioner 108 may be integrated into a common housing or "scanning head" as appropriate. Therefore, the scanning lens 112a and the corresponding second positioner 108 (i.e., the second positioner 108a) may be integrated into a common scanning head 120a. Similarly, the scanning lens 112b and the corresponding second positioner 108 (i.e., the second positioner 108b) may be integrated into a common scanning head 120b. As used herein, each of the scanning head 120a and the scanning head 120b is also collectively referred to herein as a "scanning head 120."

[0113] When incorporated into the laser processing apparatus 3100, the first positioner 106 can be operated to diffract, reflect, refract, or otherwise deflect the laser energy beam so as to deflect the beam path 114 to any of the second positioners 108. When the beam path 114 is deflected to the second positioner 108a, the beam path 114 can be deflected by any angle within a first angular range (also referred to herein as the "first primary angular range 116a") (e.g., as measured relative to the beam path 114 incident on the first positioner 106). Similarly, when the beam path 114 is deflected to the second positioner 108b, the beam path 114 can be deflected by any angle within a second angular range (also referred to herein as the "second primary angular range 116b") (e.g., as measured relative to the beam path 114 incident on the first positioner 106). As used herein, each of the first main angular range 116a and the second main angular range 116b may also be collectively referred to herein as "main angular range 116". Generally speaking, the first main angular range 116a does not overlap and is not adjacent to the second main angular range 116b. The first main angular range 116a may be greater than, less than, or equal to the second main angular range 116b. As used herein, the action of deflecting the beam path 114 within one or more of the main angular ranges 116 is referred to herein as "beam branching".

[0114] In one specific example, the operation of the first positioner 106 can be controlled to deflect the beam path 114 to the second positioner 108a (e.g., during a first branching period) and then deflect the beam path 114 to the second positioner 108b (e.g., during a second branching period after the first branching period), or vice versa, or any combination thereof. In another example, the operation of the first positioner 106 can be controlled to deflect the beam path 114 to the second positioner 108a and the second positioner 108b simultaneously. In the specific examples discussed herein, the duration of the first branching period can be greater than, less than, or equal to the duration of the second branching period. The duration of each of the first branching period and the second branching period can be greater than, equal to, or less than the positioning period of the first positioner 106. In one specific example, the duration of each of the first branching period and the second branching period can be characterized as an integer multiple of the positioning period of the first positioner 106 (wherein the integer can be any integer such as 1, 2, 3, 4, 5, 10, 20, 50, 100, etc. or between any of the values). See this section below for further discussion of the “positioning period” of the first positioner 106. In some embodiments, the duration of each branch period is greater than, equal to, or less than 200 μs, 125 μs, 100 μs, 50 μs, 33 μs, 25 μs, 20 μs, 13.3 μs, 12.5 μs, 10 μs, 4 μs, 2 μs, 1.3 μs, 1 μs, 0.2 μs, 0.1 μs, 0.05 μs, 0.025 μs, 0.02 μs, 0.013 μs, 0.01 μs, 0.008 μs, 0.0067 μs, 0.0057 μs, 0.0044 μs, 0.004 μs, etc., or between any of the values.

[0115] When the laser energy beam output by the laser source 104 is embodied as a series of laser pulses, each branching period may have a duration greater than or equal to the pulse duration of the laser pulses within the laser energy beam. However, in another embodiment, one or more branching periods may have a duration less than the pulse duration of the laser pulses within the laser energy beam. In such embodiments (or in embodiments where the laser energy beam output by the laser source 104 is embodied as a continuous or quasi-continuous laser beam), the act of beam branching may result in pulse fragmentation, thereby generating one or more pulse segments.

[0116] VII. Feature Formation

[0117] Generally speaking, the first locator 106 (whether provided in Figure 1 or Fig.31Any of the laser processing apparatuses discussed above, or any other laser processing apparatus) may be operable to rapidly scan or otherwise place a processing spot within a first scanning range (e.g., as discussed above) to form features (e.g., openings, vias, trenches, slots, scribe lines, recessed areas, etc.) in the workpiece 102. In some specific examples, the workpiece 102 may be provided as a PCB panel, a PCB, an FPC, an IC, an ICP, a semiconductor device, etc. Thus, the workpiece 102 may include one or more constituent structures, such as: an electrical conductor structure (e.g., such as a film, a foil, etc., which may be formed of copper, a copper alloy; an interconnect or wiring structure, which includes one or more metals, such as copper, titanium, titanium nitride, tantalum, etc., or any combination thereof); a dielectric structure (e.g., a build-up film, a glass-reinforced epoxy laminate, an interlayer dielectric material, a low-k dielectric material, a solder resist, a polymeric material, etc., or any combination thereof), etc., or any combination thereof. Any electrical conductor structure or dielectric structure of the workpiece 102 may have a thickness in the range of 5 μm (or 5 μm or less) to 500 μm (or 500 μm or less). Thus, the thickness of the electrical conductor structure or dielectric structure may be greater than, less than, or equal to 0.5 μm, 0.1 μm, 1 μm, 3 μm, 5 μm, 10 μm, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 50 μm, 70 μm, 80 μm, 100 μm, 110 μm, 120 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 550 μm, 600 μm, etc., or between any of the values.

[0118] In one specific example, and with reference to Figure 5, the workpiece 102 includes a dielectric structure 500 that contacts or is otherwise attached to a first electrical conductor structure 502 at a first side thereof. The dielectric structure 500 may be provided as a material such as FR4, polyimide, liquid crystal polymer, ABF, etc., and has a thickness (t1) in the range of 15 μm (or so) to 120 μm (or so). The first electrical conductor structure 502 may be provided as a copper or copper alloy foil, which may have an exposed surface treated, for example, by a chemical reaction, by a laser darkening process, etc., to increase absorption of laser energy, or not darkened. A second electrical conductor structure 504 (e.g., a pad, trace, foil, etc. formed of copper or a copper alloy, etc.) may contact or be otherwise attached to a second side of the dielectric structure 500 opposite the first side. The first electrical conductor structure 502 may have a thickness (t2) equal to (or approximately equal to) 5 μm, 7 μm, 9 μm, 12 μm, 18 μm, 35 μm, 70 μm, 105 μm, etc., or between any of the values. If present, the second electrical conductor structure may have a thickness (t3) that is less than, greater than, or equal to the thickness (t1) of the first electrical conductor structure 502. Optionally, the workpiece 102 may include one or more additional structures, such as partially in Figure 5 , which contacts or is otherwise adhered to the second electrical conductor structure 504 (eg, such that the second electrical conductor structure 504 is interposed between the dielectric structure 500 and the dielectric structure 508).

[0119] In general, features (e.g., openings, vias, trenches, slots, scribe lines, recessed areas, etc.) may be characterized as being formed by removing material from one or more constituent structures of the workpiece 102 by means of ablation. Unless expressly stated otherwise, the term "ablation" may refer to "direct ablation," "indirect ablation," or any combination thereof. Direct ablation of material in the workpiece 102 occurs when the primary cause of ablation is decomposition of the material due to absorption (e.g., linear absorption, nonlinear absorption, or any combination thereof) of energy within a beam of laser energy delivered by the material. Indirect ablation (also referred to as "stripping") of a target material (e.g., a first electrical conductor) in the workpiece 102 occurs when the primary cause of ablation is melting and vaporization due to heat generated in and transported from adjacent materials (e.g., dielectric structures 500) that absorb energy within the laser energy beam, which is ultimately delivered to the workpiece 102. Removal of the target material (e.g., first electrical conductor 502) occurs when the pressure within a vaporized material pocket between the target material and the adjacent material (e.g., formed when the adjacent material vaporizes) is sufficient to dislodge the target material from the workpiece 102. Considerations regarding removal of material by indirect ablation are known in the art and are discussed in more detail in International Publication No. WO2017 / 044646 A1.

[0120] A. Feature formation using scanning patterns

[0121] To form a structure such as a through hole (e.g., such as a Figure 6 The blind through hole 600 shown in the example, or Figure 7 The first positioner 106 may be provided as a multi-axis AOD system (e.g., the AOD system 200) and operated to scan a machining spot (i.e., a spot on the workpiece 102 illuminated by a laser energy beam directed onto the workpiece 102) along a machining trajectory defining a scanning pattern. Figure 5 5. When the laser energy beam delivered to the workpiece 102 is embodied as a plurality of pulses, the scan pattern may be characterized as a pattern of light spot locations distributed over an area of ​​the workpiece 102 where a feature (e.g., a through hole) is to be formed. During feature formation, the first positioner 106 may be operated to implement full pulse deflection or partial pulse deflection (e.g., as discussed above), or a combination of full pulse deflection and partial pulse deflection.

[0122] In general, the maximum dimension of the scan pattern (as measured in the XY plane) is less than or equal to the maximum dimension of the first scan field (as measured in the XY plane). In addition, the spot size of the processing spot scanned along the scan pattern used to form the through hole will be smaller than the maximum dimension of the through hole itself (as formed in the first electrical conductor structure 502 and measured in the XY plane). Therefore, the maximum dimension of the through hole can be equal to (or approximately equal to) 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, etc., or between any of the values. The maximum dimension of a through hole as formed in the dielectric structure (e.g., at the bottom of the through hole, or at or near the interface between the dielectric structure and the second electrical conductor structure, as measured in the XY plane) may be greater than, less than, or equal to the maximum dimension of a through hole as formed in the first electrical conductor structure 502.

[0123] The characteristics of the scan pattern may include the number of spot locations in the scan pattern, the configuration of the spot locations in the scan pattern, the order or sequence of addressing the spot locations in the scan pattern, the distance between consecutively addressed spot locations, etc. In general, the spot locations are addressed when a single laser pulse or a single series of consecutively delivered laser pulses is delivered to the workpiece 102 at the spot locations. According to specific examples described herein, one or more of the scan pattern characteristics may be selected or otherwise set taking into account one or more or all of the aforementioned characteristics (e.g., wavelength, average power, pulse duration, pulse repetition rate, pulse energy, peak power, temporal optical power profile, spot size, etc.) of the laser energy beam delivered to the workpiece 102 so that the laser energy can be evenly distributed (or at least somewhat evenly distributed) over the area of ​​the workpiece 102 where the through hole is to be formed, and then ultimately ablating the first electrical conductor structure 502 (i.e., due to indirect ablation, or a combination of direct and indirect ablation). Thereby, before all the spot positions in the scan pattern have been addressed, the region of the first electrical conductor structure 502 where the through hole is to be formed can be uniformly (or at least uniformly to some extent) heated to a temperature at or near the processing threshold temperature of the first electrical conductor structure 502. Therefore, according to the specific examples described herein, the process of forming a through hole in the workpiece 102 can be characterized as comprising the following process: forming an opening in the first electrical conductor structure 502, whereby the opening is formed in the first electrical conductor structure 502 by first addressing a plurality of spot positions in the scan pattern to uniformly (or at least uniformly to some extent) heat the region of the first electrical conductor structure 502 where the opening is to be formed (i.e., to a temperature at or near the processing threshold temperature of the first electrical conductor structure 502); and, thereafter, addressing one or more other spot positions in the scan pattern to vaporize a portion of the dielectric structure 500 below the heated region of the first electrical conductor structure 502 to expel the heated region of the first electrical conductor structure 502 from the workpiece 102 (i.e., by indirect ablation).

[0124] In view of the above, it will be appreciated that one or more of the aforementioned scanning pattern characteristics and characteristics of the laser energy beam (e.g., average power, pulse duration, pulse repetition rate, pulse energy, peak power, spot size, etc., or any combination thereof) may be selected or otherwise set such that all (at least substantially all) portions of the first electrical conductor structure 502 located within the region of the workpiece 102 where the through hole is located (including a region of the first electrical conductor structure 502 located at the center of the region of the workpiece 102 where the through hole is to be formed, also referred to herein as the "central region of the first electrical conductor 502") are melted prior to ablating the first electrical conductor structure 502 (e.g., due to indirect ablation). However, one or more of the aforementioned characteristics of the scanning pattern, the laser energy beam, or a combination thereof may be modified such that the central region of the first electrical conductor 502 is not melted, but such that a portion of the first electrical conductor 502 surrounding the central region is melted prior to ablating the first electrical conductor structure 502. In this case, the unmelted central region of the first electrical conductor 502 may still be removed by indirect ablation (eg, when the dielectric structure below the unmelted central region of the first electrical conductor 502 is vaporized).

[0125] One or more of the scan pattern characteristics may also be selected or otherwise set in consideration of the rate at which successive addressed light spot positions in the addressing scan pattern are addressed. The rate at which different light spot positions in the addressing scan pattern are addressed may be equal to (or at least substantially equal to) the update rate of the first positioner 106 during the formation of the vias, an integer multiple of the update rate of the first positioner 106 during the formation of the vias, or a combination thereof. Thus, the rate at which different light spot positions in the addressing scan pattern are addressed may correspond to the update rate of the first positioner 106 during the formation of the vias. Thus, the total amount of time required to scan the processing light spot along the scan pattern (also referred to herein as the "exposure time") may correspond to the product of the number of light spot positions in the scan pattern multiplied by the first positioning period of the first positioner 106 (i.e., when the first positioner 106 is operating to scan the processing light spot along the scan pattern).

[0126] As noted above, during the process of forming the via, the laser energy is evenly distributed (or at least somewhat evenly distributed) over the area of ​​the workpiece 102 where the via is to be formed, and then the first electrical conductor structure 502 is ablated (e.g., due to direct ablation, indirect ablation, or a combination thereof). Thus, before ablating the first electrical conductor structure 502, at least two spot locations (e.g., two, three, four, five, six, seven, eight, nine, ten, etc.) of the scan pattern are addressed. For example, simulations performed by the present inventors indicate that when a laser energy beam embodied as a series of laser pulses (i.e., wavelength such as 9.4 μm or 10.6 μm, spot size of 70 μm, pulse duration of 1 μs, and peak power up to about 1.3 kW) is directed onto a workpiece 102 provided as a PCB having a dielectric structure formed of 50 μm thick FR4, a first electrical conductor structure 502 formed of 12 μm thick copper foil (treated to increase absorption of laser energy), and a second electrical conductor structure formed of 35 μm thick copper foil (i.e., such that the laser energy beam is incident on the first electrical conductor structure 502), ablation of the first electrical conductor structure 502 begins within a period of 6 μs to 8 μs (or 6 μs to 8 μs or more) after the initial scanning of the processing spot. Thus, according to this simulation, about six to eight spot locations can be addressed by the laser energy beam before ablation of the first electrical conductor structure 502.

[0127] i. Example Embodiments of Scanning Patterns

[0128] The following is Figures 8 to 22 and Fig.24Discussion of the scan pattern illustrated in (a), which was developed by the present inventors to form a circular (or at least substantially circular) blind via hole in a workpiece 102 (e.g., provided as described above) using a laser energy beam as delivered to the workpiece 102, the laser energy beam having a wavelength in the range of 9 μm (or around 9 μm) to 11 μm (or around 11 μm) (e.g., a wavelength of 9.4 μm (or around 9.4 μm), 10.6 μm (or around 10.6 μm), etc.), a peak power in the range of 250 W (or around 250 W) to 2 kW (or around 2 kW) and a spot size in the range of 60 μm (or around 60 μm) to 90 μm (or around 90 μm). However, it should be understood that the spot size may be less than 60 μm, such as in the range of 30 μm (or around 30 μm) to 60 μm (or around 60 μm). Thus, the spot size of the machining spot scanned along the exemplary scan pattern as discussed below may be, for example, 40 μm (or above or below 40 μm), 50 μm (or above or below 50 μm), 70 μm (or above or below 70 μm), or 85 μm (or above or below 85 μm), etc., or between any of the values. Generally speaking, the pulses in the laser energy beam as delivered to the workpiece 102 have a pulse duration of 1 μs (or above or below 1 μs). Nevertheless, it will be appreciated that the scan patterns described below may be used to form features other than blind vias (e.g., through holes, trenches, grooves, or other recesses or openings), and that the scan patterns may be modified to form features other than through holes.

[0129] It should also be understood that the wavelength of the laser energy beam delivered to the workpiece 102 may be below 9 μm (e.g., in the ultraviolet or green visible range of the electromagnetic spectrum), provided that other characteristics of the laser energy beam delivered to the workpiece 102 (e.g., pulse duration, pulse repetition rate, peak power, temporal optical power profile, flux, etc.) are sufficient to process the workpiece 102. For example, the laser source 104 may be provided as a laser, such as a ULR / ULM-355-200 series laser manufactured by IPG PHOTONICS. The laser is a high power QCW fiber laser capable of producing a laser energy beam at a wavelength of 355 nm and an average power of 200 W, wherein the beam is composed of laser pulses having a pulse duration of approximately 1.4 ns and output at a pulse repetition rate of 80 MHz. In another example, the laser source 104 can be provided as a laser such as the GPLN-532 series lasers manufactured by IPG PHOTONICS (e.g., GPLN-532-200, GPLN-532-500, etc.), which can be operated in pulsed or QCW mode and is capable of generating a laser energy beam at a wavelength of 532 nm and an average power of 200 W or greater, wherein the beam is composed of laser pulses having a pulse duration of about 1.2 ns and output at a pulse repetition rate of about 50 MHz or greater.

[0130] Finally, it will be appreciated that regardless of the wavelength of the laser energy beam delivered to the workpiece 102, the laser energy beam delivered to the workpiece 102 may have any suitable or desired characteristics (e.g., in terms of spot size, pulse duration, peak power, pulse energy, average power, pulse repetition rate, etc.) based on one or more factors (such as the material construction of the workpiece 102 being processed, acceptable quality and throughput standards, etc.).

[0131] exist Figures 8 to 22 and Fig.24 In (a), the spot positions of any scan pattern are distributed in a circular configuration (e.g., on or along a common circumference of an imaginary circle). In the figure, the center of each spot position is designated by a dot or circle. The illustrated horizontal and vertical orientation axes are provided for reference, with the numbers at each axis indicating distance or position (measured in μm). Thus, Figures 8 to 22 and Fig.24 The scan pattern illustrated in (a) may be characterized as having a radius in the range of 10 μm (or so) to 60 μm (or so).

[0132] In one embodiment, the scanning pattern used to form the through-holes can be a "furthest neighbor" type scanning pattern. In a furthest neighbor type scanning pattern, the second or subsequent spot position to be addressed is as far away as possible from any other previously addressed spot position. Figure 8 and Fig. 9 Some examples of the furthest neighbor type scanning patterns are described in FIG.

[0133] refer to Figure 8 , a farthest neighbor type scanning pattern is composed of eight light spot positions (where the center of each light spot position is represented by a point such as point 800), each of which is addressed only once. As illustratively illustrated, the eight light spot positions are provided in a circular configuration (e.g., configured on or along a common circumference of an imaginary circle). Lines connecting light spot positions and numbers "1", "2", ... "8" near the light spot positions indicate the order in which the light spot positions in the scanning pattern 800 are addressed (e.g., by a laser energy beam, deflected by at least the first locator 106). Thus, light spot position 1 is the first light spot position in the scanning pattern 800 to be addressed, light spot position 2 is the second light spot position in the scanning pattern 800 to be addressed, and so on, and light spot position 8 is the last light spot position in the scanning pattern 800 to be addressed.

[0134] refer to Fig. 9 , the furthest neighbor type scanning pattern consists of sixteen light spot positions provided in a circular configuration (e.g., arranged on or along a common circumference of an imaginary circle). Fig. 9In the scan pattern shown in , each spot position overlaps another spot position. Thus, the identifiers "1, 12", "2, 11", "3, 9" ... "5, 16" near the dots specify the spot positions, and the lines connecting the spot positions indicate the order in which the spot positions in the scan pattern are addressed (e.g., by a laser energy beam, deflected by at least the first positioner 106). Thus, in Fig. 9 In the scanning pattern shown in , the point designated by "1, 12" represents the position of the first light spot position in the scanning pattern 800 to be addressed and the position of the twelfth light spot position in the scanning pattern 800 to be addressed; the point designated by "2, 11" represents the position of the second light spot position in the scanning pattern to be addressed and the position of the eleventh light spot position in the scanning pattern to be addressed; and so on.

[0135] It will be appreciated that the furthest neighbor type scanning pattern may be modified (e.g., so that the second or subsequent spot location to be addressed is not located as far away from any other previously addressed spot location) and still be suitable for forming vias. Some examples of modified furthest neighbor type scanning patterns are described in Figures 10 to 22 middle. Figures 10 to 22 The scan pattern shown in (and Figure 8 and Fig. 9 ) can generally be characterized as one of two types: a first type of scanning pattern (also referred to herein as a "first type scanning pattern"), in which the midpoints between specific pairs of consecutive addressed light spot positions are co-located (for example, at the center of an imaginary circle); and a second type of scanning pattern (also referred to herein as a "second type scanning pattern"), in which no midpoints between consecutive pairs of addressed light spot positions are co-located. Figures 8 to 16 , Figure 20 to Figure 22 and Fig.24 (a) illustrates an example of a first type of scanning pattern; Figures 17 to 19 An example of the second type of scanning pattern is described.

[0136] The second type of scanning pattern can be characterized as a scanning pattern that continuously addresses adjacent light spot locations (e.g., as shown in FIG. Fig.17 and Fig.19 ) or a scanning pattern that does not continuously address adjacent spot positions (e.g., as shown in Fig.18 ). Such as Fig.17 and Fig.19 The scanning patterns of those scanning patterns shown in are called "continuously addressed second type scanning patterns", and such as Fig.18 The scanning patterns shown in FIG. 1 are referred to as “non-continuous addressing second type scanning patterns”.

[0137] exist Fig.17 and Fig.19 In FIG. 1 , spot positions 1 and 2 are examples of spot positions that are adjacent to each other and are addressed consecutively. Fig.18 In FIG. 1 , spot positions 1 and 7 are examples of spot positions that are adjacent to each other but not continuously addressed. Fig.18 In , spot positions 1 and 2 are not adjacent to each other, but are addressed consecutively. Fig.18 In the example scan pattern shown in , spot position 7 exists (eg, along the circumference of an imaginary circle) between the successively addressed spot positions 1 and 2. Fig.18 As shown in , spot positions 12 and 1 exist (e.g., along the circumference of an imaginary circle) between the successively addressed spot positions 6 and 7. It will be appreciated that Figures 17 to 19 The scan pattern shown in can be modified so that any number of spot positions can exist (eg, along the circumference of an imaginary circle) between any two consecutive addressed spot positions in the same scan pattern.

[0138] although Figures 8 to 22 and Fig.24 The example scanning pattern illustrated in (a) is shown as having a set of a number of light spot positions (e.g., 4, 8, 12, 16, 18, or 20 light spot positions) arranged on or along a common circumference of an imaginary circle, but it will be appreciated that any scanning pattern (whether illustrated or not) may have a different number of light spot positions (e.g., 2, 3, 5, 6, 10, 15, 22, 25, 28, 30, 32, 40, 50, 60, 70, 75, 80, 100, etc., or between any of the recited values) arranged on or along a common circumference of an imaginary circle, and the light spot positions may be addressed in any suitable or desired order or sequence. For example, although Figure 8 , Figures 10 to 13 and Figures 15 to 20 The example scanning patterns illustrated in FIG. 1 are shown with multiple light spot positions that are addressed only once in sequence, but it will be appreciated that the light spot positions of any of the scanning patterns may be addressed multiple times in sequence (e.g., 2 times, 3 times, 4 times, 5 times, etc.). It should also be appreciated that the light spot positions within the common scanning pattern may be arranged on or along any other line, perimeter, segment, etc., thereby describing any desired or suitable shape (e.g., a triangle, square, rectangle, hexagon, oval, star, etc., or any combination thereof).

[0139] When scanning the machining spots along the second type scanning pattern so that non-adjacent spot positions are addressed consecutively, any number of spot positions may exist (e.g., along the circumference of an imaginary circle) between a pair of consecutively addressed spot positions. The number of such spot positions that may exist between a pair of consecutively addressed spot positions may be in the range of 3 spot positions to 10 spot positions (e.g., in the range of 4 spot positions to 6 spot positions).

[0140] ii. Additional Discussion on Characteristic Shape Distortion

[0141] It has been discovered that a through hole produced by operating the first positioner 106 (e.g., a multi-axis AOD system such as the AOD system 200) to scan the machining spot along the second type of scanning pattern as discussed above can have an elliptical opening (i.e., at the surface of the workpiece 102), such as Fig. 27 This is true even if the positions of the light spots in the second type of scanning pattern are arranged on or along a common circumference of an imaginary circle, such as Fig.28 To compensate for this distortion of the through-hole opening shape, the configuration of the light spot positions in the second type of scanning pattern may be modified (e.g., so that the light spot positions are arranged on or along a common perimeter of an imaginary ellipse, as shown in Fig.29 ). Fig.29 The modified second type scanning pattern shown in FIG. 1 can be generally characterized as an elliptical shape, wherein the major axis of the elliptical shape is Fig. 27 Any second type scanning pattern (including the aforementioned second type scanning pattern) may be modified so that the light spot positions are arranged on or along the perimeter of the common ellipse rather than on or along the circumference of the common circle. When the machining light spot is scanned along such a modified scanning pattern, the opening of the through hole finally produced will have a larger diameter than that of the common ellipse. Fig. 27 The oval shape illustrated in the figure is a more rounded shape.

[0142] iii. Additional Discussion on Scan Pattern, Via Circularity, and Pulse Slicing

[0143] It should be noted that Figures 8 to 22 and Fig.24In (a), the horizontally and vertically oriented axes do not necessarily represent the orientation of the diffraction axis of the AOD in a multi-axis AOD system (e.g., AOD system 200, which operates to scan the processing light spot along a scan pattern to form a through hole). In general, the processing light spot can be scanned along any scan pattern such as the scan pattern described herein, while the AOD system 200 operates to achieve full pulse deflection, partial pulse deflection (as discussed above, i.e., pulse slicing), or a combination thereof. When the multi-axis AOD system (e.g., AOD system 200) operates to achieve partial pulse deflection, it has been found that the roundness of the resulting through hole opening can depend on one or more factors, such as the orientation of the scan pattern (i.e., the "jump" between consecutive addressed light spot positions in the scan pattern relative to the orientation of the directional diffraction axis of the AOD in the multi-axis AOD system), the distance between consecutive addressed light spot positions in the scan pattern, and the update rate of the multi-axis AOD system when scanning the processing light spot. While not wishing to be bound by any particular theory, the inventors believe that when the RF drive frequency applied to the AOD changes while the laser pulse passes through the AO unit of the AOD during pulse slicing, there are acoustic transients in the AO unit, thereby diffracting the incident laser energy beam in an undesirable manner. The diffraction event caused by the acoustic transient may sometimes cause unacceptable distortion of the processing light spot at the workpiece 102. It has been observed that the processing light spot distortion is most severe when the difference in the RF drive frequency applied to any particular AOD is large between two consecutive first positioning cycles of the AOD. It has also been observed that if multiple AODs in a multi-axis AOD system are operated to continuously address different light spot locations in a scan pattern, the processing light spot distortion can be reduced to some extent.

[0144] For example, in Fig.14 In the scanning pattern shown in , the direction of the "jump" between spot positions 1 and 2 (and between spot positions 7 and 8, and between spot positions 9 and 10) is parallel to one diffraction axis of the AOD in the multi-axis AOD system (e.g., the first diffraction axis of the first AOD 202 of the AOD system 200), and the direction of the "jump" between spot positions 3 and 4 (and between spot positions 5 and 6, and between spot positions 11 and 12) is parallel to another diffraction axis of the AOD in the multi-axis AOD system (e.g., the second diffraction axis of the second AOD 204 of the AOD system 200). Therefore, the distance between consecutive addressed light spots aligned along the diagonally illustrated directions (each of which is parallel to the diffraction axis of the AOD in a multi-axis AOD system such as the AOD system 200) is greater than the distance between consecutive addressed light spots aligned along the horizontal or vertical directions illustrated in the figure. Therefore, in the scanning pattern shown in FIG. 1 , the direction of the "jump" between spot positions 1 and 2 (and between spot positions 7 and 8, and between spot positions 9 and 10) is parallel to another diffraction axis of the AOD in the multi-axis AOD system (e.g., the second diffraction axis of the second AOD 204 of the AOD system 200). Therefore, the distance between consecutive addressed light spots aligned along the diagonally illustrated directions (each of which is parallel to the diffraction axis of the AOD in the multi-axis AOD system such as the AOD system 200) is greater than the distance between consecutive addressed light spots aligned along the horizontal or vertical directions illustrated in the figure. Therefore, in the scanning pattern shown in FIG. 1 , the direction of the "jump" between spot positions 1 and 2 (and between spot positions 5 and 6, and between spot positions 11 and 12) is parallel to another diffraction axis of the Fig.14 When the machining spot is scanned with the scanning pattern shown in FIG. , the shape of the machining spot at the workpiece 102 may be distorted to produce a through hole opening with relatively poor roundness (e.g., as shown in FIG. 1 ). Fig.23However, if Fig.14 The orientation of the scan pattern shown in FIG. 1 is rotated relative to the diffraction axis of the AOD in a multi-axis AOD system (e.g., 45 degrees, as shown in FIG. 2 ). Fig.24 (a)), so that the direction of the relatively large "jumps" (i.e., the jumps between spot positions 1 and 2, between spot positions 3 and 4, between spot positions 5 and 6, between spot positions 7 and 8, between spot positions 9 and 10, and between spot positions 11 and 12) is not parallel to the diffraction axis of any AOD, the roundness of the resulting through-hole opening can be improved, such as Fig.24 (b) shows that only a single AOD is operated to scan the processing spot between spot positions 1 and 2 (and between spot positions 7 and 8 and between spot positions 9 and 10) or between spot positions 3 and 4 (and between spot positions 5 and 6 and between spot positions 11 and 12), as shown in FIG. Fig.14 However, it is necessary to operate multiple AODs to scan the processing spots between spot positions 1 and 2, between spot positions 3 and 4, between spot positions 5 and 6, between spot positions 7 and 8, between spot positions 9 and 10, and between spot positions 11 and 12, as shown in FIG. Fig.24 (a). Similarly, Fig.16 None of the directions of the "jumps" between consecutive addressed spot positions in the scan pattern shown in is parallel to the diffraction axis of any AOD in the multi-axis AOD system. Fig.16 When the processing spot is scanned with the scanning pattern shown in , the resulting through hole has an opening with relatively good roundness (e.g., Fig.25 ).

[0145] It should be noted that within the AOD, each applied RF drive frequency corresponds to an effective phase tilt applied to the incident laser energy beam. In detail, the phase tilt (in μrad) can be calculated as follows:

[0146] Phase tilt = λ*Δf / v

[0147] Where λ is the optical wavelength of the laser energy beam passing through the AOD (measured in nm), Δf is the deviation of the applied RF drive frequency applied to the AOD from the center frequency of the AOD (measured in Hz), and v is the speed of the acoustic wave in the AO cell (measured in m / s). If the incident laser energy beam is subjected to multiple phase tilt angles (also referred to as multiple phase tilt angle segments) with significantly different magnitudes when the AOD system is operated to achieve pulse slicing, the distortion may be severe, depending on, for example, the update rate at which the AOD system 200 is operated. However, if pulse slicing is performed so that the multiple tilt angle segments differ in magnitude by a small fraction of the wavelength of the laser energy beam, the distortion effect that would otherwise be observed can be reduced. This can also help guide the selection and orientation of the scanning pattern to be used and the update rate of a multi-axis AOD system (e.g., AOD system 200) when the multi-axis AOD system is operated to achieve partial pulse deflection when drilling a through hole.

[0148] For example, Figure 8 The direction of the "jump" between spot positions 1 and 2 in the scan pattern shown in is parallel to one diffraction axis of the AOD (e.g., the first diffraction axis of the first AOD 202 of the AOD system 200), and the direction of the "jump" between spot positions 3 and 4 is parallel to the other diffraction axis of the AOD (e.g., the second diffraction axis of the second AOD 204 of the AOD system 200). Therefore, the longest jump achieved by a single AOD is equal to about 300 μrad of tilt, which is equivalent to a phase tilt of about 4.5 μm on the diameter of the laser energy beam passing through the AOD (which can be about 15 mm, or approximately 50% of its 9.4 μm wavelength). Therefore, the jumps from spot position 1 to spot position 2 and from spot position 3 to spot position 4 are relatively large jumps.

[0149] In another example, the AOD system 200 is operated to achieve partial pulse deflection along Figure 8 The scanning pattern shown in FIG. 1 can form a through hole with an acceptable circular opening when the processing light spot is scanned at an update rate of 1 MHz (corresponding to a first positioning period of 1 μs). However, when the update rate is doubled to 2 MHz (corresponding to a first positioning period of 0.5 μs), the processing light spot is Figure 8 The scan pattern shown in becomes distorted as it is scanned, resulting in the resulting through-hole having an opening that has a shape more like a square. In contrast, a scan pattern such as Figures 17 to 19 The distance between the jumps between the positions of the consecutive addressed light spots in the scanning pattern described in the example is comparable to that of Figure 8 The distance between the jumps between consecutive addressed light spot positions in the scanning pattern described in is much smaller. For example, Fig.19 The jumps between the positions of consecutive addressed light spots in the scanning pattern shown in FIG. 1 can be less than 10 μm (compared to Figure 8The scanning pattern shown in is approximately 3 times smaller), and as a result, the distortion of the processing light spot at the workpiece 102 can be very low when the AOD in a multi-axis AOD system is driven at an update rate of 2 MHz and, additionally, even when the AOD is driven at an update rate of 8 MHz (corresponding to a first positioning period of 0.125 μs).

[0150] In view of the above, a through hole may be formed (e.g., in the aforementioned workpiece 102) by operating a first positioner 106 (e.g., a multi-axis AOD system such as the AOD system 200) at an update rate greater than 1 MHz (e.g., at an update rate greater than or equal to 2 MHz, 5 MHz, 8 MHz, 12 MHz, 25 MHz, 50 MHz, etc., or between any of the values) to move along a plurality of axes having a relatively large number (e.g., at least 40) of spot locations (e.g., 45, 50, 60, 75, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 710, 720, 730, 740, 750 The processing light spots (e.g., having a spot size within the range described above) are scanned with a second type of scanning pattern (e.g., provided in any manner as described herein) such that consecutively addressed light spot positions are spatially separated from each other by up to six light spot positions and / or such that the distance between jumps of consecutively addressed light spot positions is less than 15 μm (e.g., 13 μm, 11 μm, 10 μm, 9 μm, 8 μm, 7 μm, etc., or between any of the values).

[0151] iv. Additional Discussion on Localized Heat Accumulation

[0152] Depending on one or more factors such as the wavelength of the laser pulses delivered to the workpiece 102, the pulse duration, the pulse repetition rate, the peak power, the average power, etc., the linear absorption of the material at the spot location (for example, relative to the wavelength of the laser pulses delivered to the location), the thermal conductivity, thermal diffusivity, specific heat capacity, etc. of the material at or near the spot location, the scanning pattern along which the processing spot is to be scanned, etc., or any combination thereof, the heat generated by delivering the laser pulses to one or more spot locations may diffuse from the irradiated spot locations and accumulate in a region of the workpiece 102 outside the processing spot, thereby increasing the temperature of the workpiece 102 at the region outside the processing spot.

[0153] If the accumulated heat results in an elevated temperature at a region of the workpiece 102 located at or near the location of the spot to be irradiated by the processing spot, and if the elevated temperature is above a threshold temperature (i.e., the "processing threshold temperature"), the efficiency with which the workpiece 102 can be subsequently processed (e.g., by direct ablation, indirect ablation, or any combination thereof) can be positively affected. Generally, the processing threshold temperature associated with the material to be processed is greater than or equal to the melting point or glass transition temperature of the material to be processed, but less than its vaporization temperature. However, in another embodiment, the processing threshold temperature can be less than the melting point or glass transition temperature of the material to be processed (e.g., 98%, 95%, 93%, 90%, 89%, 87%, 85%, 80%, 75%, 70%, 65%, 50%, 40%, etc., of the melting point or glass transition temperature of the material to be processed, or between any of the values).

[0154] In some cases, the accumulated heat may increase the temperature within areas of the workpiece 102 that are not intended to be processed (each also referred to herein as a "non-feature area" of the workpiece 102). If the temperature is high enough, the non-feature area of ​​the workpiece 102 may be undesirably damaged (e.g., undesirably cracked, melted, peeled off, annealed, etc.). Therefore, it may be preferred to process the workpiece 102 in a manner that avoids undesirable accumulation of heat within the non-feature area of ​​the workpiece 102. As used herein, the temperature at which an area of ​​the workpiece 102 will be undesirably damaged is referred to as the "damage threshold temperature." It should be recognized that the damage threshold temperature of any non-feature area of ​​the workpiece 102 may depend on one or more factors, such as the thickness, thermal conductivity, thermal diffusivity, specific heat capacity, etc., optical absorptivity (relative to the beam of laser energy delivered), etc. of any material at or near the spot location or in the non-feature area, and the thermal conductivity, thermal diffusivity, specific heat capacity, size and shape, etc. of structures located near the non-feature area, or any combination thereof.

[0155] a. Avoid unwanted damage

[0156] It has been found that by scanning a laser energy beam (e.g., along the above relative to Figures 8 to 29 illustratively described scanning pattern, or otherwise) to form a blind via 600 in the workpiece 102 (e.g., as described above with respect to Figure 5 and Figure 6102 ). Example areas where the workpiece 102 may delaminate include an area at the interface between the second electrical conductor structure 504 and one or both of the dielectric structure 500 and the dielectric structure 508 at or near a peripheral area of ​​the exposed second electrical conductor structure 504 (e.g., within an area identified by circle “A”), an area at the interface between the second electrical conductor structure 504 and the dielectric structure 508 at or near a central area of ​​the exposed second electrical conductor structure 504 (e.g., within an area identified by circle “B”), etc., or any combination thereof. Experiments performed by the applicant indicate that delamination occurs when the laser pulses delivered to the workpiece 102 have relatively high peak powers. Near the end of the process of forming the blind via 600, the delivered laser pulse heats the second electrical conductor structure 504 to a significant degree, and heat is then transferred from the second electrical conductor structure 504 to non-feature regions of the dielectric structure 500 and / or the dielectric structure 508 (e.g., in regions such as the regions identified by circles “A” and / or “B”) adjacent to the heated second electrical conductor structure 504. The accumulated heat can raise the temperature of adjacent regions of the dielectric structure 500 to above its glass transition temperature (and in some cases, above its decomposition temperature), thereby causing delamination within the workpiece 102 or making the workpiece 102 more susceptible to delamination.

[0157] To prevent delamination during the process of forming the blind via 600, the applicant has discovered that the peak power of the laser pulses directed to the workpiece 102 near the end of the process can be lower than the peak power of the laser pulses previously directed to the workpiece 102. It has been discovered that reducing the peak power of the delivered laser pulses and spatially distributing the delivered laser pulses (e.g., along the axis described above relative to the workpiece 102) can be effective. Figures 8 to 29 The combination of the illustratively described scanning patterns prevents the second electrical conductor structure 504 from heating up significantly, thereby preventing adjacent areas of the dielectric structure 500 from undesirably accumulating heat that could cause delamination.

[0158] For example, and refer to Fig.30 The plurality of laser pulses to be delivered to the workpiece 102 to form the blind via 600 may be provided as pulse segments temporally divided from a common mother laser pulse 3000 by the first positioner 106 and may be provided along any suitable or desired scanning pattern (e.g., as described above with respect to Figures 8 to 29 The wavelength of the mother laser pulse 3000 may be in the range of 9 μm (or around 9 μm) to 11 μm (or around 11 μm) (for example, the wavelength is 9.4 μm (or around 9.4 μm), 10.6 μm (or around 10.6 μm), etc.), and the peak power or average power is in the range of 250 W (or around 250 W) to 2 kW (or around 2 kW).

[0159] In this case, the pulse segments may include first pulse segments 3002 and second pulse segments 3004, wherein a plurality of first pulse segments 3002 are delivered to the workpiece 102 during a first time period (e.g., which may be a total time period from the beginning of the first segment period p1 to the end of the m-th segment period pm), and thereafter, a plurality of second pulse segments 3004 are delivered to the workpiece 102 during a second time period (e.g., which may be a total time period from the beginning of the m+1-th segment period pm+1 to the end of the n-th segment period pn). Although Fig.30 Only two first pulse segments 3002 are illustrated (ie, corresponding to segment periods p1 and pm), but it will be appreciated that any number of first pulse segments 3002 may be temporally divided from the mother laser pulse 3000 between the first segment period p1 and the mth segment period pm. Fig.30 Only two second pulse segments 3004 are illustrated (i.e., corresponding to segment periods pm+1 and pn), but it will be appreciated that any number of second pulse segments 3004 may be temporally divided from the mother laser pulse 3000 between the m+1 segment period and the n segment period pn. The consecutive segment periods that temporally divide the pulse segments from the mother laser pulse 3000 during the first time period may occur continuously, intermittently, or any combination thereof, as discussed above. Likewise, the consecutive segment periods that temporally divide the pulse segments from the mother laser pulse 3000 during the second time period may occur continuously, intermittently, or any combination thereof, as discussed above. Additionally, although the mth segment period pm and the m+1th segment period pm+1 are temporally divided from the mother laser pulse 3000 during the second time period, the mth segment period pm+1 may be temporally divided from the mother laser pulse 3000 during the second time period. Fig.30 1 is described as occurring intermittently (i.e., with a delay intervening after the mth segment period pm and before the m+1th segment period pm+1), but it will be understood that the mth segment period pm and the m+1th segment period pm+1 may occur consecutively (i.e., the m+1th segment period pm+1 starts immediately after the mth segment period pm).

[0160] The first pulse segment 3002 can be characterized as having a substantially constant first optical power P1, and the second pulse segment 3004 can be characterized as having a substantially constant second optical power P2 that is less than the first optical power P1. In general, the optical power of the pulse segment can be set (e.g., to the first optical power P1 or the second optical power P2) by maintaining or changing the amplitude of the RF drive signal applied to the AOD during each segment period (as described above). In one specific example, the first optical power P1 can be in the range of 150W (or around 150W) to 300W (or around 300W) (e.g., 200W or around 200W). The second optical power P2 can be in the range of 75% to 25% of the first optical power P1 (e.g., 50% or around 50%).

[0161] The laser pulses ultimately delivered to the workpiece during the formation of the blind via hole 600 may have a spot size in the range of 60 μm (or around 60 μm) to 90 μm (or around 90 μm). However, it should be appreciated that the spot size may be less than 60 μm, such as in the range of 30 μm (or around 30 μm) to 60 μm (or around 60 μm). Thus, the machining spot scanned along the exemplary scan pattern as discussed below may have a spot size of, for example, 40 μm (or around 40 μm), 50 μm (or around 50 μm), or 85 μm (or around 85 μm).

[0162] In one specific example, the first time period is less than the second time period. For example, the first time period may be in the range of 4 μs (or 4 μs or less) to 8 μs (or 8 μs or less), and the second time period may be in the range of 8 μs (or 8 μs or less) to 12 μs (or 12 μs or less). In another specific example, the first time period may be equal to or greater than the second time period.

[0163] In one specific example, the pulse duration of each of the first pulse segments 3002 is equal to (or at least substantially equal to) the pulse duration of each of the second pulse segments 3004. For example, the first pulse segments 3002 and the second pulse segments 3004 may each have a pulse duration of 1 μs (or less than or equal to 1 μs). However, in another specific example, the pulse duration of any of the first pulse segments 3002 is greater than or less than the pulse duration of any of the second pulse segments 3004.

[0164] although Fig.30 The pulse slicing technique involving two groups of pulse segments having different optical powers (i.e., first pulse segments 3002 and second pulse segments 3004) is described, but it will be appreciated that the aforementioned pulse slicing technique may be modified to include one or more additional groups of pulse segments. Each additional group of pulse segments may include one or more pulse segments having an optical power different from the first optical power P1 or the second optical power P2, or may have an optical power different from the optical power of the immediately preceding group of pulse segments.

[0165] b. Facilitates the removal of relatively thin layers

[0166] It has been found that by scanning a laser energy beam (e.g., along the above relative to Figures 8 to 29 The scanning pattern illustratively described, or otherwise) forms a through hole in the workpiece 102 (e.g., as described above with respect to Figure 5 and Figure 6 As described above, if the thickness of the first electrical conductor structure 502 is relatively thin, if along the Figures 8 to 22 and Fig.24(a) The scanning pattern described scans the processing spot illuminated by the laser energy beam, and the through-hole opening formed in the first electrical conductor of the workpiece 102 may have poor roundness. For the purpose of discussion, if a thickness of the first electrical conductor structure 502 is less than 5 μm (or thereabouts), it can be considered "relatively thin". For example, the thickness of the relatively thin first electrical conductor structure 502 is less than or equal to 4.5 μm, 4 μm, 3 μm, 2.5 μm, 2 μm, 1.5 μm, 1 μm, etc., or is between any of the values.

[0167] In fact, as pointed out above, along the lines of Figures 8 to 22 and Fig.24 (a) When a processing spot illuminated by a laser energy beam having a set of characteristics is scanned by any of the scanning patterns described in the present invention to remove a first electrical conductor structure 502 having a thickness greater than 5 μm (e.g., greater than 5 μm, 7 μm, 9 μm, 12 μm, 18 μm, 35 μm, etc., or between any of the values), the laser energy may be uniformly distributed (or at least uniformly to some extent) over the area of ​​the workpiece 102 where the through hole is to be formed, followed by ablation of the first electrical conductor structure 502. However, simulations performed by the present applicant have shown that when the same laser energy beam (e.g., characterized by the same set of characteristics) is scanned along the same scanning pattern, if the first electrical conductor structure 502 is relatively thin (as discussed above), the first electrical conductor structure 502 will be ablated before the processing spot is scanned along the entire scanning pattern. The results of the simulations have been confirmed by experiments performed by the present applicant.

[0168] To improve the roundness of a via opening formed in the relatively thin first electrical conductor structure 502 (eg, during a process of forming a via (eg, a blind via 600 or a through-hole 700)), such as described above with respect to Figures 8 to 22 and Fig.24 The scanning pattern of any of the scanning patterns described in (a) may be modified to include a scanning pattern at or near the geometric centroid of the scanning pattern (e.g., at Figures 8 to 22 or Fig.24 (a) or more light spot positions at or near coordinates 0, 0 as described in any one of (a). In this context, Figures 8 to 22 or Fig.24 The spot positions of the scan pattern actually illustrated in (a) are referred to herein as "heating spot positions", and the one or more spot positions at or near the geometric centroid of the scan pattern are referred to herein as "removing spot positions". The heating spot positions are heated by a laser energy beam as described above with respect to Figures 8 to 22 or Fig.24(a) is addressed in any suitable manner as described above, and thereafter one or more removal spot locations are addressed. However, when addressing heating spot locations, the laser energy beam delivered to the workpiece 102 is characterized by a set of characteristics (e.g., in terms of peak power, pulse duration, pulse energy, etc.) sufficient to uniformly (or at least somewhat uniformly) heat the area of ​​the first electrical conductor structure 502 where the through hole is to be formed to a temperature at or near the processing threshold temperature of the first electrical conductor structure 502, but insufficient to cause the heated first electrical conductor structure 502 to be ablated. Thereafter, one or more removal spot locations of the modified scan pattern are addressed using a laser energy beam characterized by a set of characteristics (e.g., in terms of peak power, pulse duration, pulse energy, etc.) sufficient to ablate (e.g., by indirect ablation, direct ablation, or a combination thereof) the heated area of ​​the first electrical conductor structure 502.

[0169] In one specific example, the peak power in one or more pulses of the laser energy beam used to address the removal spot location is higher than the peak power in one or more pulses of the laser energy beam used to address each of the heating spot locations. It will be appreciated that the peak power of each laser pulse (regardless of whether it addresses a removal spot location or a heating spot location) may depend on the thickness of the first electrical conductor structure 502 (i.e., as the thickness of the first electrical conductor structure 502 decreases, the required peak power is less). For example, for a first electrical conductor structure 502 having a thickness of 2 μm, any removal spot location may be addressed by a laser pulse having a peak power in the range of 1 kW (or above) to 2 kW (or above), and a heating spot location may be addressed by a laser pulse having a peak power in the range of 250 W (or above) to 350 W (or above). When the thickness of the first conductor structure 502 is 1.5 μm, any removal spot position can be addressed by a laser pulse with a peak power in the range of, for example, 300 W (or around 300 W) to 500 W (or around 500 W), and the heating spot position can be addressed by a laser pulse with a peak power in the range of, for example, 150 W (or around 150 W) to 250 W (or around 250 W).

[0170] In another embodiment, the pulse duration of one or more pulses of the laser energy beam used to address the removal spot location is greater than or equal to the pulse duration of each pulse used to address the heating spot location. However, in general, the total amount of time for addressing the heating spot location will be greater than the total amount of time for addressing the one or more removal spot locations. For example, the total amount of time for addressing the one or more removal spot locations may be in the range of 10% (or 10% or more) to 25% (or 25% or more) of the total amount of time for addressing the heating spot location. It will be appreciated that the one or more removal spot locations may be addressed within greater than 25% (or 25% or more) of the total amount of time for addressing the heating spot location (e.g., 30% to 60% of the total amount of time for addressing the heating spot location). In this case, the energy in the laser pulses delivered during the removal step will also be used to remove a portion of the dielectric structure 500.

[0171] In some embodiments, characteristics such as peak power, pulse duration of the laser energy beam delivered to the workpiece 102 during heating and removal of the first electrical conductor structure 502 may be appropriately modified by operating the first positioner 106 as discussed above.

[0172] v. Further Discussion on Characteristic Shape Distortion

[0173] As discussed above, Figures 8 to 22 and Fig.24 The scan pattern illustrated in (a) may be characterized as having a radius in the range of 10 μm (or so) to 60 μm (or so). It will be appreciated that the radius of the scan pattern may be increased, subject to the constraints that the scan pattern characteristics (e.g., the number of spot locations in the scan pattern, the configuration of the spot locations in the scan pattern, the order or sequence of addressing the spot locations in the scan pattern, the distance between consecutively addressed spot locations, etc., or any combination thereof) and the characteristics of the laser energy beam delivered to the workpiece 102 (e.g., average power, pulse duration, pulse repetition rate, pulse energy, peak power, spot size, etc., or any combination thereof) are maintained or modified so as to be sufficient to form a via having desirable characteristics, such as the shape (e.g., roundness) of the via opening formed in the first electrical conductor 502.

[0174] For example, if Fig.17 or Fig.19, is modified to have a radius greater than about 60 μm (e.g., 70 μm or greater), the modified continuously addressed second type scanning pattern may, for example, include more spot positions (e.g., to maintain a desired spacing between adjacent spot positions, between continuously addressed spot positions, etc.). Optionally, one or more characteristics of the laser energy beam delivered to the workpiece 102 (e.g., average power, pulse duration, pulse repetition rate, pulse energy, peak power, spot size, etc.) may also be modified to form a through hole having desirable characteristics, such as the shape (e.g., roundness) of the through hole opening formed in the first electrical conductor 502. However, when modifying the continuously addressed second type scanning pattern, it may be necessary not to simply include more spot positions (e.g., to maintain a desired spacing between adjacent spot positions, between continuously addressed spot positions, etc.) because a portion of the first electrical conductor between the first spot position and the last spot position in the scanning pattern may still remain, thereby producing a through hole opening with poor roundness.

[0175] An example of a via opening having poor roundness formed in a first electrical conductor (eg, copper layer) of the workpiece 102 is shown in FIG. Fig.46 in the micrographs. Fig.46 The through hole opening shown in FIG. Fig.17 and Fig.19 The second type of scanning pattern scans the processing light spots on the workpiece 102 (for example, by the characteristics falling into the above relative to Fig.17 and Fig.19 The scanning pattern shown in FIG. 1 is formed by irradiating a laser energy beam within the range described by the scanning pattern shown in FIG. However, it is worth noting that the radius of the scanning pattern is increased to 70 μm. Fig.46 In the micrograph shown in , the "protrusion" located within the dashed area is responsible for the poor roundness of the via opening. While not wishing to be bound by any particular theory, it is believed that, prior to the time when the last spot position is addressed, the temperature of a portion of the first electrical conductor 502 at or near the first spot position of the scan pattern is below the processing threshold temperature of the first electrical conductor 502. Therefore, when the last spot position is addressed, there is not enough thermal energy within the first electrical conductor 502 at or near the first spot position to facilitate its removal.

[0176] In one embodiment, the roundness of the via opening in the first electrical conductor 502 can be improved by addressing one or more of the initially addressed light spot positions in the scan pattern after all other light spot positions have been addressed. Fig.47, after having addressed the first to the twenty-fourth light spot positions 1 to 24, the positions in the scanning pattern designated by the first light spot position 1 are again addressed (thus, the points designated by "1, 25" represent the positions of the first light spot position and the twenty-fifth light spot position in the scanning pattern). Optionally, other previously addressed light spot positions may be addressed after the twenty-fifth light spot position. For example, and again referring to Fig.47 , after addressing spot position 25, spot position 2 is addressed (thus, the point designated by "2, 26" indicates the positions of the second spot position and the twenty-sixth spot position that overlap each other), and spot position 3 may be addressed after addressing spot position 26 (thus, the point designated by "3, 27" indicates the positions of the third spot position and the twenty-seventh spot position that overlap each other). As used herein, spot positions that overlap each other (e.g., as discussed above) are referred to herein as "continuously addressed second type scanning pattern overlapping spot positions." For any continuously addressed second type scanning pattern overlapping spot positions, the last addressed spot position is referred to as the "last addressed overlapping spot position." Therefore, at the spot position designated by "1, 25," spot position 25 may be referred to as the "last addressed overlapping spot position," at the spot position designated by "2, 26," spot position 26 may be referred to as the "last addressed overlapping spot position," and so on.

[0177] In the context of maintaining a desirable roundness of the through-hole opening in the first electrical conductor, an appropriate continuously addressed second type scanning pattern provides a first light spot position as a continuously addressed second type scanning pattern overlapping light spot position, and one or more continuously addressed light spot positions subsequent to the first light spot position may also be provided as continuously addressed second type scanning pattern overlapping light spot positions. Thus, the number of continuously addressed second type scanning pattern overlapping light spot positions that may be included in the second type scanning pattern may be equal to 1, 2, 3, 4, 5, etc. Instead of specifying the number of continuously addressed second type scanning pattern overlapping light spot positions included in the second type scanning pattern, the number of continuously addressed second type scanning pattern overlapping light spot positions that may be included in the second type scanning pattern may be expressed as a percentage of the total number of light spot positions in the second type scanning pattern. In this case, the continuously addressed second type scanning pattern overlapping light spot positions may constitute up to 12% (or 12% or so) of the total number of light spot positions in the second type scanning pattern. For example, the percentage may be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, etc., or between any of the values. Ultimately, however, the number of consecutively addressed second type scanning pattern overlapping spot positions to be included in the second type scanning pattern may depend on one or more factors, such as any of the aforementioned scanning pattern characteristics, any of the characteristics of the laser energy beam delivered to the workpiece 102 (e.g., wavelength, average power, pulse duration, pulse repetition rate, pulse energy, peak power, optical intensity, flux, spot size, etc.), characteristics of the workpiece 102 (e.g., thickness of the first electrical conductor, etc.), etc., or any combination thereof. By providing the above-described Fig.47 By continuously addressing the second type scanning pattern as described, the area of ​​the first electrical conductor at or near the first light spot position (i.e., light spot position 1) can accumulate sufficient thermal energy to promote its removal, thereby obtaining a through-hole opening with good roundness in the first electrical conductor (e.g., as Fig.48 It should be noted that if too many spot positions are provided to continuously address overlapping spot positions of the second type scanning pattern, the first electrical conductor may be over-processed, thereby again obtaining a through-hole opening with a poor roundness in the first electrical conductor, such as Fig.49 as shown in .

[0178] So far, such as about Fig.17 and Fig.19 The distance between each pair of consecutively addressed light spot positions in any of the described scanning patterns is the same (or at least approximately the same) as in the consecutively addressed second type scanning pattern. Fig.17 or Fig.19 The distance between the light spot positions 3 and 4 in any one of the above is the same as the distance between the light spot position 1 and the last light spot position (ie, Fig.17 The light spot position in is 12, and Fig.19 In the context of maintaining a desired roundness of the through-hole opening in the first electrical conductor, an appropriate sequentially addressed second type scanning pattern may be configured such that the distance between the sequentially addressed light spot position pairs containing the last light spot position to be addressed may be lower than the separation distances of the remaining sequentially addressed light spot position pairs. For example, referring to Fig.50 , the distance between spot positions 24 and 25 may be lower than the distance between spot positions 1 and 2, between spot positions 10 and 11, etc. In general, the distance between the last two spot positions to be addressed (e.g., between spot positions 24 and 25) may be in the range between 30% (or around 30%) and 99% (or around 99%) of the distance between any other pair of consecutively addressed spot positions. Fig.50 With the described continuously addressed second type scanning pattern, the region of the first electrical conductor at or near the first light spot position (ie, light spot position 1) can accumulate sufficient thermal energy to facilitate its removal, thereby obtaining a via opening with good roundness in the first electrical conductor.

[0179] In another specific example, the continuously addressed second type scanning pattern may be modified to include one or more light spot positions between at least one pair of continuously addressed light spot positions. Thus, continuously addressed light spot positions in one portion of the second type scanning pattern may be adjacent to each other (e.g., as in a continuously addressed second type scanning pattern), and continuously addressed light spot positions in another portion of the second type scanning pattern may not be adjacent to each other (e.g., as in a non-continuously addressed second type scanning pattern). This type of second type scanning pattern is referred to herein as a "hybrid second type scanning pattern." An example of a hybrid second type scanning pattern is shown in Fig.51 Reference Fig.51 , the hybrid second type scanning pattern may include a spot position 25 (which is addressed consecutively after spot position 24) arranged between spot positions 1 and 2, with a distance between spot positions 24 and 25. Fig.51 Only one spot position (i.e., spot position 25) between spot positions 1 and 2 is illustrated, but it will be appreciated that multiple spot positions may be arranged between spot positions 1 and 2 or any other pair of consecutively addressed spot positions. Optionally, the hybrid second type scanning pattern may further include one or more additional spot positions, such as spot position 26 (which is addressed consecutively after spot position 25) arranged between one or more additional pairs of consecutively addressed spot positions (such as between spot positions 2 and 3). By providing the above description of the spot positions, the hybrid second type scanning pattern may further include one or more additional spot positions, such as spot position 26 (which is addressed consecutively after spot position 25), which is arranged between one or more additional pairs of consecutively addressed spot positions (such as between spot positions 2 and 3). Fig.51 With the hybrid second type scanning pattern described, a region of the first electrical conductor at or near the first light spot position (i.e., light spot position 1) can accumulate sufficient thermal energy to facilitate its removal, thereby obtaining a through-hole opening with good roundness in the first electrical conductor (e.g., Fig.48 ). However, ultimately, the number of light spot positions to be added between a pair of consecutive addressed light spot positions or the number of consecutive addressed light spot position pairs with light spot positions therebetween may depend on one or more factors, such as any of the aforementioned scanning pattern characteristics, any of the characteristics of the laser energy beam delivered to the workpiece 102 (e.g., wavelength, average power, pulse duration, pulse repetition rate, pulse energy, peak power, optical intensity, flux, spot size, etc.), characteristics of the workpiece 102 (e.g., thickness of the first electrical conductor, etc.), etc., or any combination thereof. It should be noted that if too many light spot positions are set between a pair of consecutive addressed light spot positions or if too many pairs of consecutive addressed light spot positions have one or more light spot positions between them, the first electrical conductor may be over-processed, thereby obtaining a through-hole opening with poor roundness in the first electrical conductor (e.g., as Fig.49 ).

[0180] Although the second type of scanning pattern of a through hole having a relatively large radius and used to produce an opening with good roundness has been described above with respect to Fig.47 , Fig.50 and Fig.51 Discussed separately, it will be appreciated that the characteristics unique to each type of second type scanning pattern may be combined in any suitable or desired manner.

[0181] B. Formed by the characteristics of stamping

[0182] To form a through hole (e.g., a blind via 600, such as a through hole ... Figure 6 As exemplarily shown in FIG. 1 , or perforation 700, as Figure 7 102 ), the first positioner 106 may be provided as a multi-axis AOD system (e.g., AOD system 200) and operated to repeatedly generate a processing spot at the same (or substantially the same) location at the workpiece 102. As used herein, the term "punching process" refers to the action of delivering a set of laser pulses to the same (or substantially the same) spot location at the workpiece 102 to form a feature (e.g., a through hole or other opening). During the punching process (e.g., to form a feature such as a through hole or other opening), the first positioner 106 may be operated to achieve full pulse deflection or partial pulse deflection (e.g., as discussed above, i.e., pulse slicing), or a combination of full pulse deflection and partial pulse deflection.

[0183] The first positioner 106 may be operated during a stamping process (e.g., to form a feature such as a through hole or other opening) to prevent material of the workpiece 102 (e.g., dielectric structure 500) from being excessively heated (i.e., due to irradiation by the laser pulses) or otherwise prevent the workpiece 102 (or one or more constituent structures of the workpiece 102) from being undesirably warped, delaminated, or otherwise modified. As will be discussed in more detail below, the first positioner 106 may be operated during a stamping process to ensure that laser pulses within at least one pair of consecutive laser pulses in a set of laser pulses are delivered intermittently (i.e., one laser pulse starts immediately after a previous laser pulse after a certain delay), to modify the optical power of one laser pulse relative to another laser pulse in a set of laser pulses, to modify the pulse duration of one laser pulse relative to another laser pulse in a set of laser pulses, etc., or any combination thereof.

[0184] i. Exemplary Specific Examples Regarding Pulse Slicing

[0185] refer to Fig.32 , the first positioner 106 can be operated during the stamping process to temporally divide the mother laser pulse (e.g., mother laser pulse 3201) into multiple pulse segments. Therefore, the first positioner 106 can be operated to deflect the pulse segments within at least one pair of consecutive divided pulse segments to the same angle (or at least substantially the same angle) within the main angle range 116. It will be understood that the multiple pulse segments themselves can be grouped into multiple groups of pulse segments (e.g., pulse segment groups 3200a and 3200b, each collectively referred to as "pulse segment groups 3200"). In this case, the first positioner 106 can be operated to deflect the pulse segments within the common pulse segment group 3200 to the same angle (or at least substantially the same angle) within the main angle range 116, and to deflect the pulse segments within different pulse segment groups 3200 to different angles (or at least substantially different angles) within the main angle range 116. For example, the first positioner 106 can be operated to deflect the pulse segments within the pulse segment group 3200a at Figure 1 A first angle (or a first angle) within the primary angular range 116 shown in Fig.31 ), and deflect the pulse segments in the pulse segment group 3200b by an angle within the first main angular range 116a shown in FIG. Figure 1 A second angle (or Fig.31). However, it should be understood that the pulse segments within pulse segment groups 3200a and 3200b can be considered a common pulse segment group, and therefore, all pulse segments of pulse segment groups 3200a and 3200b can be deflected to the same (or at least substantially the same) angle within the main angular range 116. As illustratively illustrated, at a given point in time, the power of a pulse segment is less than the power of the mother laser pulse 3201 from which it is temporally divided. The power difference between the mother laser pulse 3201 and the pulse segment can be the result of the diffraction efficiency of one or more AODs in the first positioner 106 when the first positioner 106 operates to generate pulse segments, inherent optical losses associated with the use of AODs in the first positioner 106, etc., or any combination thereof.

[0186] In the illustrated embodiment, the pulse segment set 3200a includes a primary pulse segment 3202a and a plurality of auxiliary pulse segments 3204a. Likewise, in the illustrated embodiment, the pulse segment set 3200b includes a primary pulse segment 3202b and a plurality of auxiliary pulse segments 3204b. As used herein, each of the primary pulse segments 3202a and 3202b may be collectively referred to as a "primary pulse segment 3202," and each of the auxiliary pulse segments 3204a and 3204b may be collectively referred to as an "auxiliary pulse segment 3204." In the illustrated embodiment, the pulse duration and pulse energy of the primary pulse segment 3202 are greater than the pulse duration and pulse energy of each auxiliary pulse segment 3204. However, in other embodiments, the pulse segment set 3200a may include a plurality of primary pulse segments 3202a and one or more auxiliary pulse segments 3204a. Likewise, in other embodiments, the pulse segment group 3200b may include a plurality of primary pulse segments 3202b and one or more secondary pulse segments 3204b.

[0187] In one specific example, the main pulse segment 3202 is generally used to ablate (i.e., via direct ablation, indirect ablation, or a combination thereof) the first electrical conductor structure 502 of the workpiece 102. In this case, the pulse duration and pulse energy of a single main pulse segment 3202 are sufficient to ablate the first electrical conductor structure 502 of the workpiece 102. In another case, the pulse duration and pulse energy of each of the plurality of main pulse segments 3202 in the common pulse segment set 3200 are sufficient to enable ablation of the first electrical conductor structure 502 by the plurality of main pulse segments 3202. However, in another specific example, if the first electrical conductor structure 502 is not present on the workpiece 102 at the desired spot location, one or more main pulse segments 3202 may be used to ablate (i.e., via direct ablation, indirect ablation, or a combination thereof) the dielectric structure 500 of the workpiece 102. It should be noted that the pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as by Fig.32 ) may be greater, less than, or the same as any other primary pulse segment 3202 in the same pulse segment group in terms of pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as shown by Fig.32 , as shown in the various pulse fragments in Figure 1).

[0188] In one specific example, each auxiliary pulse segment 3204 is generally used to remove the dielectric structure 500 of the workpiece 102 without significantly processing the second electrical conductor structure 504 (e.g., to form a blind via, such as the blind via 600). In this case, the pulse duration and pulse energy of each auxiliary pulse segment 3204 are sufficient to remove (e.g., via ablation, vaporization, melting, etc., or any combination thereof) the first electrical conductor structure 502 of the workpiece 102, and the pulse duration and / or pulse energy of at least the last auxiliary pulse segment 3204 are sufficient to remove the dielectric structure 500 of the workpiece 102 without significantly processing the second electrical conductor structure 504. Therefore, the pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as shown by Fig.32 ) may be greater, less than, or the same as any other auxiliary pulse segment 3204 in the same pulse segment group in terms of pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as shown by Fig.32 , as shown in the various pulse fragments in Figure 1).

[0189] In another specific example, one or more auxiliary pulse segments 3204 may be used to ablate (i.e., via direct ablation, indirect ablation, or a combination thereof) the second electrical conductor structure 504 of the workpiece 102. In this case, the one or more auxiliary pulse segments 3204 delivered to the workpiece 102 after the second electrical conductor structure 504 has been ablated may be used to remove (e.g., via ablation, vaporization, melting, etc., or any combination thereof) the dielectric structure 508 (e.g., to form a through-hole, such as the through-hole 700). Thus, the pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as indicated by the peak optical power profile) of at least one auxiliary pulse segment 3204 in the set of pulse segments may be substantially the same as the pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as indicated by the peak optical power profile) of at least one auxiliary pulse segment 3204 in the set of pulse segments. Fig.32 ) may be greater, less than, or the same as any other auxiliary pulse segment 3204 in the same pulse segment group in terms of pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as shown by Fig.32 , as shown in the various pulse fragments in Figure 1).

[0190] However, in yet another embodiment, the pulse segment groups 3200a and 3200b can be used to form a through hole (e.g., through hole 700). In this case, the pulse segment group 3200a can be used to sequentially remove material from the first electrical conductor structure 502 and the dielectric structure 500, and the pulse segment group 3200b can be used to sequentially remove material from the second electrical conductor structure 504 and the dielectric structure 508.

[0191] In yet another specific example, if the dielectric structure 500 is a non-homogeneous material (e.g., FR4, which is known as a glass-reinforced epoxy laminate containing, for example, woven fiberglass cloth within an epoxy matrix), and if the portion of the dielectric structure 500 at the desired spot location of the workpiece 102 contains a certain amount of glass material, then the pulse duration and pulse energy of at least one auxiliary pulse segment 3204 intended to remove the glass material may be modified relative to the pulse duration and pulse energy of at least one other auxiliary pulse segment 3204 intended only to remove epoxy, so that the glass material at the desired spot location may be efficiently removed (e.g., via ablation, vaporization, melting, etc., or any combination thereof). Thus, the pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as indicated by the pulse duration, peak optical power, peak optical power profile ... Fig.32 ) may be greater, less than, or the same as any other auxiliary pulse segment 3204 in the same pulse segment group in terms of pulse duration, pulse energy, peak optical power, temporal optical power profile (e.g., rectangular, as shown by Fig.32 , as shown in the various pulse fragments in Figure 1).

[0192] If continuous laser pulses are delivered intermittently during the stamping process, the first positioner 106 can be operated to ensure that the amount of time between the start of one laser pulse and the end of the previous laser pulse (also referred to herein as the "gap time") is sufficient to allow the material at or near the spot location to cool to some extent (e.g., to below the damage threshold temperature of the material) before the next laser pulse is delivered. For example, and with reference to Fig.32 , the first positioner 106 may be operable to ensure that the gap time Tg1a between the start of the first auxiliary pulse segment 3204a of the pulse segment group 3200a and the end of the main pulse segment 3202a of the pulse segment group 3200a is sufficient to allow the material of the dielectric structure 500 at or near the light spot location to cool to some extent before delivering the first auxiliary pulse segment 3204a, thereby avoiding undesirable modification of the material of the dielectric structure 500 at or near the light spot location. The gap time Tg1b between the start of the first auxiliary pulse segment 3204b of the pulse segment group 3200b and the end of the main pulse segment 3202b of the pulse segment group 3200b may be greater than, less than, or equal to the gap time Tg1a.

[0193] like Fig.32 As shown in , the first positioner 106 can also operate to ensure that the gap time Tg2 between the successively delivered auxiliary pulse segments 3204a of the pulse segment group 3200a is sufficient to maintain the material of the dielectric structure 500 at or near the light spot location at a temperature sufficient to allow suitable processing of the dielectric structure 500 without undesirably damaging the surrounding materials. The gap time between the successively delivered auxiliary pulse segments 3204b of the pulse segment group 3200b can be greater than, less than, or equal to the gap time Tg2.

[0194] a. Sequential and interleaved deflection of laser pulse groups

[0195] refer to Fig.32, the first positioner 106 can be operated during the stamping process to temporally divide the mother laser pulse 3201 into a plurality of pulse segment groups 3200, wherein the pulse segments within the laser pulse segment group 3200a are all deflected to the same (or at least substantially the same) angle within the main angular range 116 before the pulse segments within the laser pulse segment group 3200b are deflected to different angles. In this way, the first positioner 106 operates to deflect the laser pulse segment groups 3200a and 3200b according to a sequential deflection technique. In other embodiments, the first positioner 106 can be operated to deflect the laser pulse segment groups 3200a and 3200b according to an interleaved deflection technique. In the interleaved deflection technique, the first positioner 106 operates during the stamping process to temporally divide the mother laser pulse 3201 into multiple pulse segment groups 3200, wherein one or more pulse segments within the laser pulse segment groups 3200a and 3200b are alternately deflected between different angles within the main angle range 116.

[0196] For example, refer to Fig.33 , the first positioner 106 may operate according to an interleaved deflection technique, wherein the main pulse segment 3202a is deflected at Figure 1 A first angle (or a first angle) within the primary angular range 116 shown in Fig.31 ), and then the main pulse segment 3202b is deflected at Figure 1 A second angle (or Fig.31 ), and then the auxiliary pulse segment 3204a is deflected at a first angle within the second main angular range 116b shown in Figure 1 A first angle (or a first angle) within the primary angular range 116 shown in Fig.31 ), and then the auxiliary pulse segment 3204b is deflected at a first angle within the first main angular range 116a shown in Figure 1 A second angle (or Fig.31 116b).

[0197] In another example, and with reference to Fig.34 , the first locator 106 may be configured according to a method similar to that described with respect to Fig.33 The interleaved deflection technique described above operates in the same manner as described above, but the auxiliary pulse segments 3204a and 3204b are alternately placed in Figure 1 between the first angle and the second angle within the main angular range 116 shown in (or between Fig.31 The first main angular range 116a and the second main angular range 116b are deflected between the first angles shown in FIG.

[0198] Taking into account the aforementioned spacing times between the pulse segments in the pulse segment group, the total amount of time necessary to form a feature (e.g., a through hole or other opening) by stamping can vary depending on whether the first positioner 106 operates according to a sequential deflection technique or an interleaved deflection technique. For example, if the total amount of time necessary to form a feature using the pulse segment group 3200a is Ta, and the total amount of time necessary to form a feature using the pulse segment group 3200b is Tb (where Tb may be greater than, less than, or equal to Ta), then the first positioner 106 operates according to the sequential deflection technique (see, e.g., Fig.32 ), the total amount of time required to form two features using pulse segment groups 3200a and 3200b is Tt1. Fig.33 The total amount of time necessary to form the same two features using the pulse segment groups 3200a and 3200b is Tt2, which is less than Tt1. Fig.33 In the figure, the gap time Tglb' is shown as being greater than the gap time Tg1b, but can be made equal to the gap time Tg1b by, for example, adjusting the pulse duration and / or power of the auxiliary pulse segment 3204a, by adjusting the gap time between the main pulse segment 3202b and the first auxiliary pulse segment 3204a, by adjusting the gap time Tg2 between the auxiliary pulse segments 3204a, by adjusting the gap time between the last auxiliary pulse segment 3204a and the first auxiliary pulse segment 3204b, etc. or any combination thereof.

[0199] Likewise, using Fig.34 The total amount of time necessary to form the same two features using pulse segment groups 3200a and 3200b is Tt2. Fig.34 In the figure, the gap time Tg1b" is shown as being less than the gap time Tg1b, but can be made equal to the gap time Tg1b by, for example, adjusting the pulse duration and / or power of the first auxiliary pulse segment 3204a, by adjusting the gap time between the main pulse segment 3202b and the first auxiliary pulse segment 3204a, by adjusting the gap time Tg2 between the auxiliary pulse segments 3204a, etc. or any combination thereof.

[0200] Although embodiments have been discussed herein with respect to stamping, it will be appreciated that the embodiments are also applicable to the use of scanning patterns (by following the examples described herein, for example, with respect to Figures 8 to 29 , Fig.47 , Fig.50 or Fig.51 Any of the scanning patterns illustratively described may scan a machining spot, or otherwise) to form features.

[0201] b. Additional Embodiments Regarding Laser Pulse Groups

[0202] exist Figure 32 to Figure 34 In the specific example illustrated in , each of the pulse segments in the pulse segment group has a rectangular temporal power profile, and the peak optical power of any pulse segment in the pulse segment group is the same as the peak optical power of all other pulse segments in the pulse segment group. In another specific example, one or more pulse segments in the pulse segment group may have a temporal power profile of any other shape, the peak optical power of any pulse segment in the pulse segment group may be different from the peak optical power of any other pulse segment in the pulse segment group, or any combination thereof.

[0203] In addition, Figure 32 to Figure 34 It is described in that between different pulse segment groups, the characteristics of the pulse segments in one pulse segment group (i.e., in terms of pulse energy, pulse duration, time power profile, number of pulse segments, gap time, etc.) are the same (or substantially the same) as the characteristics of the corresponding pulse segments in another pulse segment group. Therefore, the pulse segment groups divided in time from a common mother pulse can be regarded as the same. In another specific example, at least one characteristic of at least one pulse segment in one pulse segment group (e.g., in terms of pulse energy, pulse duration, time power profile, number of pulse segments, gap time, etc.) is different from the characteristics of at least one corresponding pulse segment in another pulse segment group. Therefore, the pulse segment groups divided in time from a common mother pulse can be regarded as different.

[0204] Figure 35 to Figure 45 Other specific examples of illustrative pulse segment groups that may be generated by operating the first positioner 106 during a stamping process or during scanning a processing light spot (e.g., by scanning the processing light spot along any of the aforementioned scanning patterns as discussed herein, or otherwise) to form a feature (e.g., a through hole such as a blind via, a perforation, or other opening).

[0205] refer to Fig.42 , the temporal power profile of auxiliary pulse segment 3204 is continuously modulated (e.g., as shown by the downward sloping line). In this case, Fig.42 The auxiliary pulse segment 3204 shown in FIG. 1 may be deflected at a single angle within the primary angular range 116 or may be deflected at multiple angles within a common primary angular range 116 (e.g., over time). Fig.42 , reference numeral 3204' represents an alternative auxiliary pulse segment to an alternative auxiliary pulse segment 3204, wherein the temporal power profile is continuously modulated (eg, to increase rather than decrease over time). Fig.44 and Fig.45 An alternative embodiment is described in which the auxiliary pulse segments 3204 can have different continuously modulated time power profiles.

[0206] refer to Fig.43 , in a stepwise manner, modulates the temporal power profile of the auxiliary pulse segment 3204. In this case, Fig.43 The auxiliary pulse segments 3204 shown in FIG. 3 may be deflected at a single angle within the primary angular range 116, or may be deflected at multiple angles (e.g., over time) within a common primary angular range 116. Fig.42 In the embodiment shown in Fig.43 The auxiliary pulse segment 3204 shown in FIG. 3 may be flipped (eg, such that the auxiliary pulse segment 3204 has a relatively lower optical power before being modulated to have a relatively higher optical power).

[0207] IX. Conclusion

[0208] The foregoing describes the embodiments and examples of the present invention and should not be construed as limiting them. Although several specific embodiments and examples have been described with reference to the accompanying drawings, it will be readily understood by those skilled in the art that many modifications to the disclosed embodiments and examples and other embodiments are possible without significantly departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the claims. For example, a person with ordinary knowledge in the art will understand that the subject matter of any sentence, paragraph, example, or embodiment may be combined with some or all of the subject matter in other sentences, paragraphs, examples, or embodiments, unless the combinations are mutually exclusive. The scope of the present invention should therefore be determined by the claims, and the equivalents of the technical solutions are included in the scope of the present invention.

Claims

1. A laser processing device, comprising: a positioner for deflecting the beam of laser energy; a first scan head and a second scan head, each scan head comprising a second positioner and a scan lens; and Controller, configured as: controlling the positioner to temporally divide the beam of laser energy into a plurality of pulse segments, wherein the plurality of pulse segments include a first group of pulse segments and a second group of pulse segments, controlling the positioner to deflect the first set of pulse segments to the first scanning head, controlling the positioner to deflect the second set of pulse segments to the second scan head, and The positioner is controlled to alternately deflect the pulse segments within the first group of pulse segments and the second group of pulse segments.

2. The laser processing equipment according to claim 1, wherein: Each group of pulse segments includes a main pulse segment and one or more auxiliary pulse segments.

3. The laser processing equipment as claimed in claim 2, wherein: In at least one group of pulse segments, the optical power of the main pulse segment is higher than that of the one or more auxiliary pulse segments.

4. The laser processing equipment as claimed in claim 2, wherein: In at least one group of pulse segments, the main pulse segment has a lower optical power than the one or more auxiliary pulse segments.

5. The laser processing equipment according to claim 2, wherein: The controller is configured to: controlling the positioner to maintain a first gap time between the main pulse segment and the first auxiliary pulse segment; and The positioner is controlled to maintain a second gap time between consecutive auxiliary pulse segments, the second gap time being different from the first gap time. The laser processing equipment of claim 5 , wherein the second interval time is shorter than the first interval time.

7. The laser processing equipment of claim 1, wherein at least two pulse segments in at least one group of pulse segments have different temporal optical power distributions.

8. The laser processing apparatus of claim 1, wherein at least two pulse segments in at least one group of pulse segments have different pulse widths.

9. The laser processing apparatus of claim 1, wherein at least one laser pulse in the first set of pulse segments has substantially the same characteristics as a corresponding laser pulse in the second set of pulse segments.

10. The laser machining apparatus of claim 1, wherein at least one laser pulse within the first set of pulse slices has substantially different characteristics from a corresponding laser pulse within the second set of pulse slices.

11. The laser processing equipment of claim 1, wherein the controller is configured to control the positioner to stagger and deflect at least one pulse segment in the first group and the second group.

12. The laser processing apparatus of claim 1, wherein the positioner comprises an acousto-optic deflector (AOD).

13. A controller for laser processing equipment, the controller comprising: processor; as well as a memory storing instructions that, when executed by the processor, cause the controller to: controlling a positioner to temporally divide the beam of laser energy into a plurality of pulse segments, wherein the plurality of pulse segments include a first group of pulse segments and a second group of pulse segments, controlling the positioner to deflect the first group of pulse segments to a first scanning head, controlling the positioner to deflect the second set of pulse segments to a second scan head, and The positioner is controlled to alternately deflect the pulse segments within the first group of pulse segments and the second group of pulse segments.

14. The controller of claim 13, wherein each group of pulse segments comprises a primary pulse segment and one or more auxiliary pulse segments.

15. The controller of claim 14, wherein the instructions, when executed by the processor, further cause the controller to: controlling the positioner to maintain a first gap time between the main pulse segment and the first auxiliary pulse segment; and The positioner is controlled to maintain a second gap time between consecutive auxiliary pulse segments, the second gap time being different from the first gap time.

16. The controller of claim 13, wherein when the processor executes the instructions, the controller further controls the positioner to generate at least two pulse segments in at least one group of pulse segments with different temporal optical power distributions.

17. The controller of claim 13, wherein when the processor executes the instructions, the controller is further caused to control the positioner to generate at least two pulse segments in at least one group of pulse segments with different pulse widths.

18. The controller of claim 13, wherein when the processor executes the instructions, the controller is further caused to control the positioner to stagger deflect at least one pulse segment from the first group and the second group.

19. A non-transitory computer-readable storage medium, which, when the stored instructions are executed by a processor of a controller of a laser processing device, causes the controller to perform operations comprising: controlling a positioner to temporally divide the beam of laser energy into a plurality of pulse segments, wherein the plurality of pulse segments include a first group of pulse segments and a second group of pulse segments, controlling the positioner to deflect the first group of pulse segments to a first scanning head, controlling the positioner to deflect the second set of pulse segments to a second scan head, and The positioner is controlled to alternately deflect the pulse segments within the first group of pulse segments and the second group of pulse segments.

20. The non-transitory computer-readable storage medium of claim 19, wherein each group of pulse segments includes a primary pulse segment and one or more auxiliary pulse segments.

21. The non-transitory computer readable storage medium of claim 20, wherein the operations further comprise: controlling the positioner to maintain a first gap time between the main pulse segment and the first auxiliary pulse segment; as well as The positioner is controlled to maintain a second gap time between consecutive auxiliary pulse segments, the second gap time being different from the first gap time.

22. The non-transitory computer-readable storage medium of claim 19, wherein: The operations also include controlling the positioner to generate at least two pulse segments within at least one set of pulse segments having different temporal optical power distributions.

23. The non-transitory computer-readable storage medium of claim 19, wherein: The operations also include controlling the positioner to generate at least two pulse segments within at least one set of pulse segments having different pulse widths.

24. The non-transitory computer readable storage medium of claim 19, wherein the operations further comprise controlling the positioner to stagger deflect at least one pulse segment from the first group and the second group.

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