Laser processing apparatus, method for operating the same, and method for processing a workpiece using the same.

Abstract

To provide methods of forming vias in workpieces such as printed circuit boards.SOLUTION: Some embodiments relate to techniques for indirectly ablating a region of an electrical conductor structure of a printed circuit board by spatially distributing laser energy throughout the region of the electrical conductor structure before the electrical conductor structure is indirectly ablated. Other embodiments relate to techniques for temporally dividing laser pulses and modulating the optical power within laser pulses, and the like.SELECTED DRAWING: Figure 1

Description

Cross-reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 859,572, filed Jun. 10, 2019; U.S. Provisional Patent Application No. 62 / 930,287, filed Nov. 4, 2019; U.S. Provisional Patent Application No. 62 / 970,648, filed Feb. 5, 2020; and U.S. Provisional Patent Application No. 63 / 026,564, filed May 18, 2020, each of which is incorporated herein by reference in its entirety. Background

[0002] I.Technical field Embodiments of the present invention relate to an apparatus and method for laser processing a workpiece.

[0003] II. Explanation of Related Technologies Laser processes are often used to form blind vias and through vias (typically less than 150 μm in diameter) in workpieces such as printed circuit boards (both different types of rigid and flexible). To form vias, laser processes that can be used are so-called "punch" processes, "trepan" processes, or combinations thereof. During the punch process, a laser energy beam is irradiated onto a workpiece that is stationary while the via is being formed. In contrast, during the trepan process, the laser energy beam is moved relative to the workpiece to form a via. Conventionally, during the trepan process, the laser energy beam is moved so as to scan the spot irradiated on the workpiece by the laser energy beam in a spiral or circular pattern. Summary

[0004] One embodiment can be characterized as a method for forming a feature within a workpiece comprising a first structure and a second structure. The feature includes an opening formed in the first structure. In this method, a laser energy beam irradiated onto the workpiece can be scanned such that the laser energy beam is incident on the first structure and sequentially irradiates the laser energy onto a plurality of spatially distinct spots of a scan pattern. The scan may include a) irradiating the laser energy onto 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 formed, and b) after a) irradiating the laser energy onto at least two of the plurality of spatially distinct spot locations to indirectly ablate the first structure within the region, thereby forming the opening.

[0005] Other embodiments can be characterized as an apparatus for forming features within a workpiece comprising a first structure and a second structure. The features include an opening formed in the first structure. The apparatus may include a laser source capable of generating a laser energy beam that can propagate along a beam path incident on the first structure of the workpiece, a positioner capable of deflecting the beam path, and a controller communicatively coupled to the positioner. The controller may be configured to control the operation of the positioner to perform the scanning process described in the paragraph above.

[0006] Further embodiments can be characterized as an apparatus comprising a laser source, an acousto-optic deflector (AOD) system, and a controller. The laser source is capable of generating a laser energy beam having at least one laser pulse, the laser energy beam being capable of propagating along a beam path to a workpiece. The AOD system is capable of deflecting the beam path and includes a first AOD capable of deflecting the beam path along a first axis in response to a given first RF signal. The controller is communicatively coupled to the AOD system and configured to control the operation of the AOD system such that the frequency of the first RF signal changes at least twice to temporally divide a common laser pulse incident on the AOD system into multiple pulse slices, the frequency of the first RF signal changing at a rate of 20 kHz or more.

[0007] Further embodiments can be characterized as an apparatus comprising a laser source, a first scan head having a scanning lens, a second scan head having a scanning lens, a positioner, and a controller. The laser source is capable of generating a laser energy beam having at least one laser pulse, and the laser energy beam is capable of propagating to a workpiece along the beam path. The positioner is configured to connect the first scan head and the second scan head. Scan head The beam path can be selectively deflected between the positioner and the positioner. The controller is communicatively connected to the positioner and is configured to control the operation of the positioner to temporally divide a common laser pulse incident on the positioner into a plurality of pulse slices, including a first pulse slice set and a second pulse slice set. The controller is further configured to control the operation of the positioner to deflect the first pulse slice set to the first scan head and the second pulse slice set to the second scan head, wherein at least one pulse slice in the second pulse slice set is temporally located between two consecutive pulse slices in the first pulse slice set. [Brief explanation of the drawing]

[0008] [Figure 1] Figures 1 and 31 schematically show a laser processing apparatus according to one embodiment of the present invention. [Figure 2] Figure 2 schematically shows a multi-axis AOD system that can be incorporated into a first positioner in one embodiment. [Figure 3-4] Figures 3 and 4 schematically illustrate a method for performing pulse slicing in one embodiment. [Figure 5] Figure 5 is a schematic cross-sectional view showing an embodiment of a workpiece that can be processed by a laser processing device. [Figure 6-7] Figures 6 and 7 are schematic cross-sectional views illustrating embodiments of features that can be formed on the workpiece described in relation to Figure 5 using a laser processing apparatus. [Figure 8-22] Figures 8 to 22 and 24(a) show examples of embodiments of scan patterns in which process spots irradiated by a laser energy beam, as described in Figure 5, are scanned to form features as described in Figures 6 and 7. [Figure 23] Figures 23, 24(b), 25, and 26 are micrographs of non-penetrating vias formed in a workpiece (for example, as shown in Figure 6) when a process spot is scanned along the scan patterns shown in Figures 14, 24(a), 16, and 15, respectively. In Figures 23 and 24(b), the diameter d of the non-penetrating via is approximately 100 μm. In Figure 25, the diameter d of the non-penetrating via is approximately 75 μm. In Figure 26, the diameter d of each non-penetrating via is approximately 180 μm. [Figure 24(a)] Figures 8 to 22 and 24(a) show examples of embodiments of scan patterns in which process spots irradiated by a laser energy beam, as described in Figure 5, are scanned to form features as described in Figures 6 and 7. [Figure 24(b)]Figures 23, 24(b), 25, and 26 are micrographs of non-penetrating vias formed in a workpiece (for example, as shown in Figure 6) when a process spot is scanned along the scan patterns shown in Figures 14, 24(a), 16, and 15, respectively. In Figures 23 and 24(b), the diameter d of the non-penetrating via is approximately 100 μm. In Figure 25, the diameter d of the non-penetrating via is approximately 75 μm. In Figure 26, the diameter d of each non-penetrating via is approximately 180 μm. [Figure 25] Figures 23, 24(b), 25, and 26 are micrographs of non-penetrating vias formed in a workpiece (for example, as shown in Figure 6) when a process spot is scanned along the scan patterns shown in Figures 14, 24(a), 16, and 15, respectively. In Figures 23 and 24(b), the diameter d of the non-penetrating via is approximately 100 μm. In Figure 25, the diameter d of the non-penetrating via is approximately 75 μm. In Figure 26, the diameter d of each non-penetrating via is approximately 180 μm. [Figure 26] Figures 23, 24(b), 25, and 26 are micrographs of non-penetrating vias formed in a workpiece (for example, as shown in Figure 6) when a process spot is scanned along the scan patterns shown in Figures 14, 24(a), 16, and 15, respectively. In Figures 23 and 24(b), the diameter d of the non-penetrating via is approximately 100 μm. In Figure 25, the diameter d of the non-penetrating via is approximately 75 μm. In Figure 26, the diameter d of each non-penetrating via is approximately 180 μm. [Figure 27] Figure 27 schematically shows a plan view of the shape of a via opening formed by scanning a process spot along a second type scan pattern. [Figure 28] Figure 28 shows an exemplary circular arrangement of spot locations that, when scanned by a laser energy beam, generate vias with elliptical apertures as illustrated in Figure 27. [Figure 29] Figure 29 shows an exemplary elliptical arrangement of spot locations that, when scanned by a laser energy beam, generate vias with a more circular aperture shape than the aperture shape shown in Figure 27. [Figure 30] Figure 30 is a set of diagrams illustrating a method for performing pulse slicing during the formation of non-penetrating vias in one embodiment. [Figure 31] Figures 1 and 31 schematically show a laser processing apparatus according to one embodiment of the present invention. [Figure 32-45] Figures 32 to 45 illustrate a method for performing pulse slicing during the formation of various features in one embodiment. [Figure 46] Figures 46, 48, and 49 are micrographs of via apertures formed in one embodiment of the present invention. [Figure 47] Figures 47, 50, and 51 illustrate a method for forming a via with an opening similar to that shown in Figure 48. [Figure 48] Figures 46, 48, and 49 are micrographs of via apertures formed in one embodiment of the present invention. [Figure 49] Figures 46, 48, and 49 are micrographs of via apertures formed in one embodiment of the present invention. [Figure 50] Figures 47, 50, and 51 illustrate a method for forming a via with an opening similar to that shown in Figure 48. [Figure 51] Figures 47, 50, and 51 illustrate a method for forming a via with an opening similar to that shown in Figure 48. Detailed explanation

[0009] The following describes examples of embodiments with reference to the attached drawings. Unless explicitly stated, the sizes, positions, and distances between components, features, and elements in the drawings are not necessarily to scale and are exaggerated for ease of understanding. Similar numbers throughout the drawings represent similar elements. Therefore, identical or similar numbers may be mentioned by reference to other drawings even if they are not mentioned or described in the corresponding drawings. Furthermore, elements without reference numbers may also be mentioned by reference to other drawings.

[0010] The terms used in the specification are for the purpose of describing particular exemplary embodiments only and are not intended to be limiting. Unless specifically defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. As used herein, unless the content clearly indicates otherwise, the singular form is intended to include the plural form. Further, the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise indicated, when a range of values is recited, that range includes not only the sub-ranges between the upper and lower limits thereof, but also the upper and lower limits. Unless otherwise indicated, terms such as "first" and "second" are used only to distinguish elements from each other. For example, a certain node can be referred to as "the first node," and similarly, another node can be referred to as "the second node," or vice versa.

[0011] Unless otherwise indicated, terms such as "about" and "around" mean that the quantity, size, formulation, parameter, and other quantities and characteristics are approximate, not exact, and need not be exact, and may be approximate, further / alternatively larger or smaller, as appropriate or to reflect tolerances, conversion factors, rounding, measurement errors, and other factors known to those skilled in the art. In this specification, spatially relative terms such as "downward", "below", "lower", "upward", and "upper" may be used to facilitate description when stating the relationship of one element or feature to another element or feature as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations in addition to the orientation shown in the figures. For example, an element described as being "downward" or "below" another element or feature will face "upward" of another element or feature when the object in the figure is inverted. Thus, the exemplary term "downward" can include both upward and downward orientations. When the object faces a different orientation (e.g., rotated 90 degrees or in another orientation), the spatially relative descriptors used in this specification can be interpreted accordingly.

[0012] The section headings used in this specification are for organization purposes only and should not be construed as limiting the subject matter described, unless otherwise specifically referred to. It will be understood that many different forms, embodiments, and combinations are possible without departing from the spirit and teachings of the present disclosure, and the present disclosure should not be construed as limited to the examples of embodiments described herein. Rather, these examples and embodiments are provided so that the present disclosure is complete and inclusive and conveys the scope of the present disclosure to those skilled in the art.

[0013] I. Overview The embodiments described herein generally relate to methods and apparatus for laser processing (or more simply, “processing”) a workpiece. Generally, the processing is carried out entirely or partially by irradiating the workpiece with laser radiation to heat, melt, evaporate, ablate, scratch, decolorize, polish, roughen, carbonize, foam, or modify one or more properties or characteristics (e.g., chemical composition, atomic structure, ionic structure, molecular structure, electronic structure, microstructure, nanostructure, density, viscosity, refractive index, permeability, relative permittivity, texture, color, hardness, transmittance to electromagnetic radiation, or any combination thereof) of one or more materials forming the workpiece. The material to be processed may be located outside the workpiece before or during processing, or it may be located entirely inside the workpiece before or during processing (i.e., not outside the workpiece).

[0014] Specific examples of processes that can be performed by the disclosed laser processing apparatus, which will be described in more detail below, include via drilling or other hole formation. It will be understood that the embodiments described herein can be extended to perform or facilitate cutting, punching, welding, scribing, engraving, marking (e.g., surface marking, sub-surface marking, etc.), laser-induced forward transfer, cleaning, bleaching, repair of high-luminance pixels (e.g., color filter darkening, modification of OLED materials, etc.), film removal, surface texturing (e.g., roughening, smoothing, etc.), or similar, or any combination thereof. Thus, one or more features that may be formed on or within a workpiece as a result of machining may include openings, slots, vias or other holes, grooves, trenches, scribe lines, grooves, recesses, conductive traces, ohmic contacts, resistance patterns, human-readable or machine-readable marks (e.g., comprising one or more areas within or on a workpiece having one or more distinguishable characteristics visually or tactilely), or similar features, or any combination thereof. Features such as openings, slots, vias, and holes may have any preferred or desirable shape in a top view (e.g., circular, elliptical, square, rectangular, triangular, tubular, or similar, or any combination thereof). Furthermore, features such as openings, slots, vias, and holes may extend completely through the workpiece (e.g., to form a so-called "through via," "through hole," etc.) or only partially within the workpiece (e.g., to form a so-called "non-through via," "non-through hole," etc.).

[0015] Workpieces that can be processed can be collectively characterized as being formed from one or more metals, polymers, ceramics, composites, or any combination thereof (for example, whether alloys, compounds, mixtures, solutions, composites, etc.). Examples of workpieces specifically described herein include printed circuit board (PCB) panels (also referred to herein as "PCB panels"), PCBs, flexible printed circuits (FPCs), integrated circuits (ICs), and IC packages (ICPs). However, light-emitting diodes (LEDs), LED packages, semiconductor wafers, and electronic or optical device substrates (e.g., Al2O3, AlN, BeO, Cu, GaAS, GaN, Ge, InP, Si, SiO2, SiC, Si 1-x Ge x Substrates formed from such materials (or any combination thereof or any combination of these alloys), lead frames, lead frame blanks, plastics, untempered glass, heat-tempered glass, chemically strengthened glass (e.g., via ion exchange processes), quartz, sapphire, plastics, silicon, etc., components of electronic displays (e.g., TFTs, color filters, organic LED (OLED) arrays, quantum dot LED arrays, etc., or substrates on which any combination thereof is formed), lenses, mirrors, screen protectors, turbine blades, powders, films, foils, plates, molds (for example) It can be seen that other types of workpieces can also be profitably processed, such as wax molds, molds for injection molding processes and investment casting processes, fabrics (textiles, felt, etc.), surgical instruments, medical implants, packaged products, shoes, bicycles, automobiles, automotive or aerospace parts (e.g., frames, body panels, etc.), household electrical appliances (e.g., microwave ovens, ovens, refrigerators, etc.), and device housings (for example, watches, computers, smartphones, tablet computers, wearable electronic devices, etc., or any combination thereof).

[0016] Therefore, the materials that can be processed include one or more metals such as Al, Ag, Au, Cu, Fe, In, Mg, Pt, Sn, Ti, or any combination thereof (whether alloy or composite, for example), conductive metal oxides (e.g., ITO), transparent conductive polymers, ceramics, waxes, resins, inorganic dielectric materials (e.g., used in interlayer dielectric structures; silicon oxide, silicon nitride, silicon oxynitride, or any combination thereof), low-k dielectric materials (methylsilsesquioxane (MSQ), hydrogen silsesquioxane (HSQ), tetraethyl orthosilicate fluoride (FTEOS), or any combination thereof), organic dielectric materials (e.g., SILK, benzocyclobutene, Nautilus (all manufactured by Dow), polyfluorotetraethylene (manufactured by DuPont), FLARE (Allied This includes glass fibers, polymer materials (such as those manufactured by Chemical Co., Ltd., or any combination thereof), polyamides, polyimides, polyesters, polyacetals, polycarbonates, modified polyphenylene ethers, polybutylene terephthalates, polyphenylene sulfides, polyethersulfones, polyetherimides, polyetheretherketones, liquid crystal polymers, acrylonitrile butadiene styrene, or any compounds, composites, or alloys thereof), leather, paper, assemblers (e.g., Ajinomoto Build-Up Film, also known as "ABF"), glass fiber reinforced epoxy laminates (e.g., FR4), prepregs, solder resists, or any composites, laminates, or other combinations thereof.

[0017] II. System Overview Figure 1 schematically shows a laser processing apparatus according to one embodiment of the present invention.

[0018] Referring to the embodiment shown in Figure 1, a laser processing apparatus 100 (hereinafter also simply referred to as the “apparatus”) for processing a workpiece 102 can be characterized as comprising a laser source 104 that generates 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 the second positioner 108, the third positioner 110, and the scan lens 112 are optional and may 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 needed.

[0019] As will be described in more detail below, the first positioner 106 is capable of diffracting the laser energy beam to deflect the beam path 114 to one of the second positioners 108. As used herein, the term “beam path” means the path through which the laser energy in the laser energy beam travels as it propagates 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 can be deflected at any angle within the first angular range (also referred herein as the “primary angular range 116”) (for example, this is measured with respect to the beam path 114 incident on the first positioner 106).

[0020] The second positioner 108 is capable of diffracting, reflecting, refracting, or similarly performing any combination thereof (i.e., "deflecting" the laser energy beam) generated by the laser source 104 and deflected by the first positioner 106, so as to deflect the beam path 114 toward the scan lens 112. When deflecting the beam path 114 toward the scan lens 112, the second positioner 108 can deflect the beam path 114 at any angle within a second angular range (also referred to herein as the "secondary angular range 118") (for example, this is measured with respect to the optical axis of the scan lens 112).

[0021] The laser energy deflected by the scan lens 112 is typically focused by the scan lens 112 to irradiate the workpiece 102 and transmitted to propagate along the beam axis. The laser energy irradiated onto 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.).

[0022] As used herein, the term “spot size” means the diameter or maximum spatial width of the laser energy beam irradiating a region of the workpiece 102 that is at least partially processed by the irradiated laser energy beam at the point where the beam axes intersect (also called the “process spot,” “spot position,” or simply “spot”). For the purposes of this specification, the spot size is defined as the optical intensity from the beam axis being 1 / e of the optical intensity at the beam axis. 2It is measured as the radial or transverse distance to where it drops down to. Generally, the spot size of a laser energy beam is smallest at the beam waist. When irradiated onto the workpiece 102, the laser energy in the beam can be characterized as hitting the workpiece 102 with a spot size in the range of 2 μm to 200 μm. However, it can be understood that the spot size can be smaller than 2 μm or larger than 200 μm. Thus, a laser energy beam irradiated onto the workpiece 102 can have a spot size greater than, smaller 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 any value between these values.

[0023] Furthermore, the apparatus 100 may include one or more other optical components (e.g., beam traps, beam expanders, beam shapers, beam splitters, apertures, filters, collimators, lenses, mirrors, prisms, polarizers, phase retarders, diffractive optical elements (commonly known as DOEs in the art), refractive optical elements (commonly known as ROEs in the art), etc., or any combination thereof) for focusing, expanding, collimating, shaping, polarizing, filtering, splitting, combining, cropping, absorbing, or modifying and adjusting the laser energy beam as it propagates along the beam path 114, so as to direct the laser energy beam towards the first positioner 106, the second positioner, etc., or similar, or any combination thereof.

[0024] A. Laser source In one embodiment, the laser source 104 can generate laser pulses. Therefore, the laser source 104 may include a pulsed laser source, a CW laser source, a QCW laser source, a burst-mode laser, or any combination thereof. If the laser source 104 includes a QCW laser source or a CW laser source, the laser source 104 may operate in pulsed mode or in non-pulsed mode, but may further include a pulse gating unit (e.g., an acousto-optic (AO) modulator (AOM), a beam chopper, etc.) that temporally modulates the beam of laser radiation output from the QCW laser source or CW laser source. Although not shown, the apparatus 100 may optionally include one or more harmonic generating crystals (also known as "wavelength conversion crystals") configured to convert the wavelength of light output by the laser source 104. However, in other embodiments, the laser source 104 may be provided as a QCW laser source or a CW laser source and may not include a pulse gating unit. Thus, the laser source 104 can be broadly characterized as capable of generating a laser energy beam that can be represented as a series of laser pulses that can then propagate along the beam path 114, or as a continuous or quasi-continuous laser beam. Although many embodiments described herein refer to laser pulses, it should be understood that a continuous or quasi-continuous beam can be used as an alternative or additional method where appropriate or necessary.

[0025] The laser energy output by the laser source 104 may have one or more wavelengths in the ultraviolet (UV), visible, or infrared (IR) regions of the electromagnetic spectrum. The laser energy in the UV region of the electromagnetic spectrum may have one or more wavelengths in the range of 10 nm (or around) to 385 nm (or around), such as 100 nm, 121 nm, 124 nm, 157 nm, 200 nm, 334 nm, 337 nm, 351 nm, 380 nm, or wavelengths between any of these values. The laser energy in the visible green region of the electromagnetic spectrum may have one or more wavelengths in the range of 500 nm (or around) to 560 nm (or around), such as 511 nm, 515 nm, 530 nm, 532 nm, 543 nm, 568 nm, or wavelengths between any of these values. The laser energy in the IR region of the electromagnetic spectrum may have one or more wavelengths in the range of 750 nm (or around) to 15 μm (or around), 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, or wavelengths in any of these values.

[0026] When the laser energy beam is represented 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 with respect to time) in the range of 10 fs to 900 ms. However, it can be understood that the pulse duration may be shorter than 10 fs or longer than 900 ms. Thus, at least one laser pulse output by the laser source 104 is 10fs, 15fs, 30fs, 50fs, 100fs, 150fs, 200fs, 300fs, 500fs, 600fs, 750fs, 800fs, 850fs, 900fs, 950fs, 1ps, 2ps, 3ps, 4ps, 5ps, 7ps, 10ps, 15ps, 25ps, 50ps, 75ps, 100ps, 200ps, 500ps, 1ns, 1.5ns, 2ns, 5ns, 10ns, 20ns, 50ns, 10 The pulse duration can be shorter than, longer than, or equal to, a value between these values, such as 0ns, 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.

[0027] The laser pulses output by the laser source 104 can have an average power in the range of 5mW to 50kW. However, it can be understood that the average power may be lower than 5mW or higher than 50kW. Thus, the laser pulses output by the laser source 104 can have an average power of 5mW, 10mW, 15mW, 20mW, 25mW, 50mW, 75mW, 100mW, 300mW, 500mW, 800mW, 1W, 2W, 3W, 4W, 5W, 6W, 7W, 10W, 15W, 18W, 25W, 30W, 50W, 60W, 100W, 150W, 200W, 250W, 500W, 2kW, 3kW, 20kW, 50kW, etc., or an average power lower than, higher than, or equal to any of these values.

[0028] Laser pulses can be output by the laser source 104 at pulse repetition rates in the range of 5 kHz to 5 GHz. However, it can be understood that the pulse repetition rate may be lower than 5 kHz or higher than 5 GHz. Thus, laser pulses can be output by the laser source 104 at pulse repetition rates lower than, higher than, or equal to, values ​​in the range of 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 values ​​in between these values.

[0029] In addition to wavelength, average power, and pulse duration and pulse repetition rate when the laser energy beam is expressed as a series of laser pulses, the laser energy beam irradiated onto the workpiece 102 can be characterized by one or more other properties such as pulse energy and peak power. Such properties include sufficient light intensity (W / cm²) to process the workpiece 102 (for example, to form one or more features). 2 (measured in) and fluence (J / cm²) 2 The process spot on the workpiece 102 is irradiated with a process spot (measured by, for example, a pulse duration, average power, pulse repetition rate, spot size, etc.) to process the workpiece 102 (for example, to form one or more features), and can be selected (for example, based on one or more other characteristics as needed, such as wavelength, pulse duration, average power, pulse repetition rate, spot size, etc.).

[0030] Examples of laser types that may characterize the laser source 104 include gas lasers (e.g., carbon dioxide 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, passive mode-locked solid bulk or fiber lasers, dye lasers, mode-locked diode lasers, pulsed lasers (e.g., ms pulsed lasers, ns pulsed lasers, ps pulsed lasers, fs pulsed lasers), CW lasers, QCW lasers, etc., or any combination thereof. Depending on the configuration, a gas laser (e.g., a carbon dioxide laser, etc.) may be configured to operate in one or more modes (e.g., CW mode, QCW mode, pulsed mode, or any combination thereof). Specific examples of laser sources that may be provided as laser source 104 include BOREAS, HEGOA, SIROCCO, or CHINOOK series lasers manufactured by EOLITE, PYROFLEX series lasers manufactured by PYROPHOTONICS, PALADIN Advanced 355 or DIAMOND series (e.g., DIAMOND E series, G series, J-2 series, J-3 series, J-5 series), FLARE NX series, MATRIX QS DPSS series, MEPHISTO Q series, AVIA LX series, AVIA NX series, RAPID NX series, HYPERRAPID NX series, RAPID series, HELIOS series, FIDELITY series, MONACO series, OPERA series, or RAPID FX series lasers, SPECTRA ASCEND series, EXCELSIOR series, EXPLORER series, FEMTOTRAIN series, HIGHQ-2 series, HIPPO series, ICEFYRE series, NAVIGATOR series, QUANTA-RAY series, QUASAR series, SOLSTICS, manufactured by PHYSICS.Lasers from the ACE series, SPIRIT series, TALON series, VANGUARD series, or VGEN series; lasers from the PULSTAR series or FIRESTAR series manufactured by SYNRAD; lasers from the TRUFLOW series manufactured by TRUMPF (e.g., TRUFLOW 2000, 2600, 3000, 3200, 3600, 4000, 5000, 6000, 6000, 8000, 10000, 12000, 15000, 20000); lasers from the TRUCOAX series (e.g., TRUCOAX 1000); lasers from the TRUDISK series, TRUPULSE series, TRUDIODE series, TRUFIBER series, or TRUMICRO series; lasers from the FCPAμJEWEL or FEMTOLITE series manufactured by IMRA AMERICA; AMPLITUDE Lasers manufactured by SYSTEMES (TANGERINE and SATSUMA series, and oscillators of MIKAN and T-PULSE series), and lasers manufactured by IPG PHOTONICS (CL series, CLPF series, CLPN series, CLPNT series, CLT series, ELM series, ELPF series, ELPN series, ELPP series, ELR series, ELS series, FLPN series, FLPNT series, FLT series, GLPF series, GLPN series, GLR series, HLPN series, HLPP series, RFL series, TLM series, TLPN series, TLR series, ULPN series, ULR series, ULM series) Examples of laser sources include lasers from the Leeds, VLM series, VLPN series, YLM series, YLPF series, YLPN series, YLPP series, YLR series, YLS series, FLPM series, FLPMT series, DLM series, BLM series, or DLR series (including, for example, GPLN-532-100-M, GPLN-532-200, GPLN-532-500, ULR / ULM-355-200, etc.), or similar lasers, or any combination thereof, one or more laser sources.

[0031] B. First positioner Generally, the first positioner 106 is (for example) 、1 By deflecting the beam path 114 within the following angular range 116, the beam axis can be moved relative to the workpiece 102 along the X-axis (or X direction), the Y-axis (or Y direction), or a combination thereof. Although not shown, the Y-axis (or Y direction) can be understood to mean an axis (or direction) perpendicular to the shown X-axis (or X direction) and Z-axis (or Z direction).

[0032] The movement of the beam axis relative to the workpiece 102 performed by the first positioner 106 is generally limited so that the process spot can be scanned, moved, or positioned within a first scan area projected by the scan lens 112. Generally, 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, and the beam size of the laser energy beam incident on the first positioner 106, the first scan area may extend to a distance shorter than, longer 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, or any of these values. As used herein, the term “beam size” means the diameter or width of a laser energy beam, where the optical intensity is 1 / e of the optical intensity along the propagation axis along the beam path 114, from the beam axis. 2 It can be measured as a radial or transverse distance down to the point where it drops down. The maximum dimension of the first scan area (for example, in a plane containing the X and Y axes (hereinafter referred to as the "XY plane")) may be greater than, equal to, or less than the corresponding maximum dimension (measured in the XY plane) of a feature (e.g., an opening, a recess, a via, a trench, etc.) formed on the workpiece 102.

[0033] Generally, the first positioner 106 is provided as an AO deflector (AOD) system, which comprises one or more AODs having AO cells formed from materials such as crystalline germanium (Ge), gallium arsenide (GaAs), chalcite (PbMoO4), tellurium dioxide (TeO2), quartz, glassy SiO2, arsenic trisulfide (As2S3), lithium niobate (LiNbO3), or any combination thereof. In one embodiment, the AOD system comprises at least one single-element AOD (e.g., one, two, three, four, five, six, etc.), at least one multi-element AOD (e.g., one, two, three, four, five, six, etc.), or any combination thereof. In this specification, an AOD system containing only one AOD is referred to as a “single-cell AOD system,” and an AOD system containing more than one AOD is referred to as a “multi-cell AOD system.” As used herein, a “single-element” AOD means an AOD having only one ultrasonic converter acoustically coupled to an AO cell, and a “multi-element” AOD contains two or more ultrasonic converters acoustically coupled to a common AO cell. An AOD system may be provided as a single-axis AOD system (for example, capable of deflecting the beam axis along a single axis) or as a multi-axis AOD system (for example, capable of deflecting the beam axis along one or more axes, such as the X-axis, or the Y-axis, or any combination thereof) by deflecting the beam path 114 in a corresponding manner. Generally, a multi-axis AOD system may be provided as a single-cell AOD system or a multi-cell AOD system. A multi-cell multi-axis AOD system typically includes multiple AODs, each capable of deflecting the beam axis along a different axis. For example, a multi-cell multi-axis system may include a first AOD (e.g., a single-element or multi-element AOD system) capable of deflecting the beam axis along one axis (e.g., along the X-axis) and a second AOD (e.g., a single-element or multi-element AOD) capable of deflecting the beam axis along a second axis (e.g., along the Y-axis).A single-cell multi-axis system typically includes a single AOD capable of deflecting the beam axis along two axes (e.g., along the X and Y axes). For example, a single-cell multi-axis system may include two or more ultrasonic converters acoustically coupled to orthogonally arranged planes, faces, or sides of a common AO cell.

[0034] As will be understood by those skilled in the art, optical optical (AO) technology (e.g., AOD, AOM, etc.) utilizes the diffraction effect caused by one or more sound waves propagating through the AO cell (along the "diffraction axis" of the AOD) to diffract an incident light wave (i.e., a laser energy beam in the context of this application) simultaneously propagating through the AO cell (along the "optical axis" within the AOD). Diffraction of the incident laser energy beam produces a diffraction pattern that typically includes zero-order and first-order diffraction peaks, and may also include other higher-order (e.g., second-order, third-order, etc.) diffraction peaks. As is known in the art, the portion of the laser energy beam diffracted at the zero-order diffraction peak is called the "zero-order" beam, and the portion of the laser energy beam diffracted at the first-order diffraction peak is called the "first-order" beam, and so on. Generally, the zero-order beam and other-order beams (e.g., the first-order beam) propagate along different beam paths as they exit the AO cell (e.g., through the optical output side of the AO cell). For example, the zero-order beam propagates along the zero-order beampath, and the primary beam propagates along the primary beampath.

[0035] Sound waves are typically input to the AO cell by applying an RF drive signal (e.g., from one or more drivers of the first positioner 106) to an ultrasonic converter element. The characteristics of the RF drive signal (e.g., amplitude, frequency, phase, etc.) can be controlled (based on one or more control signals output by controller 122, component-specific controllers, or any combination thereof) to adjust how the incident light wave is diffracted. For example, the frequency of a given RF drive signal determines 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 can be calculated as follows:

number

[0036] The primary beam path exiting the AO cell can typically be considered as a beam path 114 rotated or deflected within the AO cell. Unless otherwise specified herein, the beam path 114 exiting the AO cell corresponds to the primary beam path. The central axis (also referred to herein as the “rotation axis”) around which the beam path 114 exiting the AO cell is rotated (for example, with respect to the beam path 114 when incident on the AO cell) is orthogonal to both the diffraction axis of the AO cell and the optical axis along the direction in which the incident laser energy beam propagates within the AO cell when the AOD is operated or driven to diffract the incident laser energy beam. Thus, the AOD deflects the incident beam path 114 within a plane (also referred to herein as the “deflection plane”) that includes (or otherwise substantially parallel to) the diffraction axis of the AO cell and the optical axis within the AO cell. In this specification, the spatial range in which the AOD can deflect the beam path 114 within the deflection plane is referred to as the “scan region” of the AOD. Therefore, the first scan region of the first positioner 106 can be considered to correspond to the scan region of a single AOD (for example, when the first positioner 106 includes a single AOD), and can be considered to correspond to the combined scan region of multiple AODs (for example, when the first positioner 106 includes multiple AODs).

[0037] The first positioner 106 can be characterized as having a “first positioning speed,” which means the speed at which the first positioner 106 positions (and thereby moves the beam axis) a process spot to any position within the first scan area. For example, the first positioning speed may be greater than or less than 8 kHz, 10 kHz, 20 kHz, 30 kHz, 40 kHz, 50 kHz, 75 kHz, 80 kHz, 100 kHz, 250 kHz, 500 kHz, 750 kHz, 1 MHz, 5 MHz, 10 MHz, 20 MHz, 40 MHz, 50 MHz, 75 MHz, 100 MHz, 125 MHz, 150 MHz, 175 MHz, 200 MHz, 225 MHz, 250 MHz, or any value between these values. In this specification, this range is also referred to as the first positioning bandwidth. During the operation of the first positioner 106, an RF drive signal is repeatedly supplied to one or more ultrasonic transducers of the first positioner 106, and the first positioning bandwidth corresponds to (e.g., equal to, or at least substantially equal to) the rate at which the RF drive signal is supplied. The rate at which the RF drive signal is supplied is also called the “update rate” or “refresh rate”. In this specification, the reciprocal of the first positioning rate is called the “first positioning period”, and means the shortest time it takes for the position of a process spot to change from one location in the first scan area to another location in the first scan area. Therefore, the first positioner 106 can be characterized as having a first positioning period that is longer than or less than a value between any of these values, such as 200 μs, 125 μs, 100 μs, 50 μs, 33 μs, 25 μs, 20 μs, 15 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.

[0038] It is understandable that the material forming the AO cell depends on the wavelength of the laser energy propagating along the beam path 114 to enter the AO cell. For example, if the wavelength of the deflected laser energy is in the range of 2 μm (or around) to 20 μm (or around), a material such as crystalline germanium can be used; if the wavelength of the deflected laser energy is in the range of 1 μm (or around) to 11 μm (or around), a material such as gallium arsenide or arsenic trisulfide can be used; and if the wavelength of the deflected laser energy is in the range of 200 nm (or around) to 5 μm (or around), a material such as glassy SiO2, quartz, lithium niobate, chalcite, and tellurium dioxide can be used.

[0039] If the laser energy beam output by the laser source 104 is represented as a series of laser pulses, the first positioner 106 can be operated to change the beam path 114 at different angles within the primary angle range 116. In one embodiment, the first positioning period is longer than the pulse duration of each laser pulse. Thus, when the AOD is driven at a fixed RF drive frequency (or a set of fixed RF drive frequencies), the laser pulses pass through the AO cells of the AOD. By maintaining the fixed RF drive frequency (or a set of fixed RF drive frequencies) applied to the AOD while the laser pulses are passing through the AO cells of the AOD, the laser pulses can generally be deflected uniformly over the entire pulse duration of the laser pulses, and for this reason is sometimes called "full pulse deflection". However, in other embodiments, the first positioning period may be shorter than the pulse duration of the laser pulses, so that the laser pulses can pass through the AO cells of the AOD when the RF drive frequency (or a frequency within a set of RF drive frequencies) is changed. By changing the RF drive frequency applied to the AOD as the laser pulse passes through the AOD's AO cell, the laser pulse can be temporally divided, a technique sometimes referred to as "partial pulse deflection" or "pulse slicing." Aspects of pulse slicing are described in more detail below. While the pulse slicing technique is applied herein to temporally divide a laser pulse, it will be understood that these techniques can similarly be applied to temporally divide a laser energy beam represented as a continuous or quasi-continuous laser beam.

[0040] C. Second position Generally, the second positioner 108 is (for example) 、2 Next angle range 118 By deflecting the beam path 114 within the system, it is possible to move the beam axis relative to the workpiece 102 along the X-axis (or X direction), the Y-axis (or Y direction), or a combination thereof.

[0041] The movement of the beam axis relative to the workpiece 102 by the second positioner 108 is generally limited so that the process spot can be scanned, moved, or positioned within a second scan area projected by the scan lens 112. Generally, 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, and the spot size, the second scan area may extend to a distance longer than the corresponding distance of the first scan area in either the X or Y direction. From the above perspective, the second scan area may extend in either the X or Y direction to a distance shorter than, longer 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, or any of the values ​​between these. The maximum dimension of the second scan area (for example, in the XY plane) may be greater than, equal to, or less than the maximum dimension (measured in the XY plane) of the features (e.g., openings, recesses, vias, trenches, scribe lines, conductive traces, etc.) formed on the workpiece 102.

[0042] In terms of the configuration described herein, the beam axis movement performed by the first positioner 106 can be superimposed on the beam axis movement performed by the second positioner 108. Therefore, the second positioner 108 can scan the first scan area within the second scan area.

[0043] Generally, the positioning speed at which the second positioner 108 can position a process spot at any position within the second scan area (thus moving the beam axis within the second scan area and / or scanning the first scan area within the second scan area) is smaller than the range of the first positioning bandwidth (also referred to herein as the "second positioning bandwidth"). In one embodiment, the second positioning bandwidth is in the range of 500 Hz (or around there) to 8 kHz (or around there). For example, the second positioning bandwidth may be higher than, equal to, or lower 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, or any of these values ​​or between them.

[0044] In one embodiment, the second positioner 108 may be provided as a galvanometer mirror system including two galvanometer mirror components: a first galvanometer mirror component (e.g., an X-axis galvanometer mirror component) configured to move the beam axis along the X-axis relative to the workpiece 102, and a second galvanometer mirror component (e.g., a Y-axis galvanometer mirror component) configured to move the beam axis along the Y-axis relative to the workpiece 102. However, in other embodiments, the second positioner 108 may be provided as a galvanometer mirror system including only a single galvanometer mirror component configured to move the beam axis along both the X-axis and the Y-axis relative to the workpiece 102. In yet another embodiment, the second positioner 108 may be provided as a rotating polyhedron mirror system, etc. Thus, it can be understood that, depending on the specific 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.

[0045] D. Third position The third positioner 110 moves the workpiece 102 (e.g., workpieces 102a and 102b) relative to the scan lens 112, thereby moving the workpiece 102 relative to the beam axis. The movement of the workpiece 102 relative to the beam axis is generally limited to enable scanning, moving, or positioning of process spots within the third scan region. Depending on one or more factors, such as the configuration of the third positioner 110, the third scan region may extend to a distance longer than or equal to the corresponding distance of the second scan region in the X direction, the Y direction, or any combination thereof. However, generally, the maximum dimension of the third scan region (e.g., in the XY plane) is greater than or equal to the corresponding maximum dimension (measured in the XY plane) of the features formed on the workpiece 102. If necessary, the third positioner 110 may be able to move the workpiece 102 relative to the beam axis within a scan area extending in the Z direction (for example, over a range of 1 mm to 50 mm). Thus, the third scan area may extend along the X, Y, and / or Z directions.

[0046] In terms of the configurations described herein, it should be understood that the movement of the process spot on the workpiece 102 (performed, for example, by the first positioner 106 and / or the second positioner 108) can be superimposed on the movement of the workpiece 102 performed by the third positioner 110. For this reason, the third positioner 110 can scan the first scan area and / or the second scan area within the third scan area. Generally, the positioning speed at which the third positioner 110 can position the workpiece 102 at any position within the third scan area (thus moving the workpiece 102, scanning the first scan area within the third scan area, and / or scanning the second scan area within the third scan area) is smaller than the second positioning bandwidth (also referred to herein as the "third positioning bandwidth"). In one embodiment, the third positioning bandwidth is less than 500 Hz (or around that). For example, the third positioning bandwidth may be 500Hz, 250Hz, 150Hz, 100Hz, 75Hz, 50Hz, 25Hz, 10Hz, 7.5Hz, 5Hz, 2.5Hz, 2Hz, 1.5Hz, 1Hz, or equal to or lower than any of these values.

[0047] In one embodiment, the third positioner 110 is provided as one or more linear stages (each capable of providing translational movement to the workpiece 102 along the X, Y, and / or Z directions), one or more rotary stages (each capable of providing rotational movement to the workpiece 102 about axes parallel to the X, Y, and / or Z directions), or any combination thereof. In one embodiment, the third positioner 110 includes an X stage for moving the workpiece 102 along the X direction, and a Y stage supported by the X stage (making it movable along the X direction by the X stage) for moving the workpiece 102 along the Y direction.

[0048] As described above, the apparatus 100 may use a so-called "stacked" positioning system as the third positioner 110. This "stacked" positioning system allows the workpiece 102 to move while the positions of components other than the workpiece, such as the first positioner 106, the second positioner 108, and the scan lens 112, are stationary within the apparatus 100 (for example, via one or more supports, frames, etc., as known in the art). In other embodiments, the third positioner 110 may be arranged and operated to move one or more components, such as the first positioner 106, the second positioner 108, the scan lens 112, or any combination thereof, while keeping the workpiece 102 stationary.

[0049] 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 a first positioner 106, a second positioner 108, a scan lens 112, or any combination thereof, are transported by one or more linear or rotary stages (e.g., mounted on a frame or gantry), and the workpiece 102 is transported by one or more other linear or rotary stages. In such an embodiment, the third positioner 110 includes one or more linear or rotary stages that are arranged and operable to move one or more components, such as a scan head (e.g., including a second positioner 108 and a scan lens 112), and one or more linear or rotary stages that are arranged and operable to move the workpiece 102. For example, the third positioner 110 may include a Y-stage that moves the workpiece 102 along the Y-direction and an X-stage that moves the scan head along the X-direction. Examples of split-axis positioning systems that may be usefully or conveniently used in apparatus 100 include any of those disclosed in U.S. Patents No. 5,751,585, 5,798,927, 5,847,960, 6,606,999, 7,605,343, 8,680,430, 8,847,113, or in U.S. Patent Application Publication 2014 / 0083983, or any combination thereof. Each of these documents is incorporated herein by reference in its entirety.

[0050] In one embodiment, the third positioner 110 includes a Z-stage, where the Z-stage may be positioned and configured to move the workpiece 102 along the Z-direction. In this case, the Z-stage may be transported by one or more of the other stages described above for moving or positioning the workpiece 102, or transport one or more of the other stages described above for moving or positioning the workpiece 102, or any combination thereof. In another embodiment, the third positioner 110 includes a Z-stage, where the Z-stage may be positioned and configured to move the scan head along the Z-direction. Thus, when the third positioner 110 is provided as a split-axis positioning system, the Z-stage may transport the X-stage, or be transported by the X-stage. By moving the workpiece 102 or the scan head along the Z-direction, the spot size on the workpiece 102 can be changed.

[0051] In yet another embodiment, one or more components, such as the first positioner 106, the second positioner 108, and the scan lens 112, may be transported by a multi-axis articulated robot arm (e.g., a 2-axis, 3-axis, 4-axis, 5-axis, or 6-axis arm). In such an embodiment, the second positioner 108 and / or the scan lens 112 may be transported by the end effector of the robot arm, if necessary. In yet another embodiment, the workpiece 102 may be transported directly on the end effector of the multi-axis articulated robot arm (i.e., without the third positioner 110). In yet another embodiment, the third positioner 110 may be transported on the end effector of the multi-axis articulated robot arm.

[0052] E. Scan Lens Generally, the scan lens 112 (for example, provided as either a simple lens or a composite lens) is typically configured to focus a laser energy beam directed along the beam path to generate a beam waist that may be located at or near a desired process spot. The scan lens 112 may be provided as an f-theta lens, a telecentric lens, an axicon lens (in which case a series of beam waists are generated, resulting in multiple process spots offset from each other along the beam axis), or any combination thereof. The scan lens 112 may be provided as a non-telecentric lens (as illustrated), a f-theta lens, a telecentric lens, an axicon lens (in which case a series of beam waists are generated, resulting in multiple process spots offset from each other along the beam axis), or any combination thereof.

[0053] In one embodiment, the scan lens 112 is provided as a fixed focal length lens and is connected to a movable scan lens positioner (e.g., a lens actuator, not shown) to change the position of the beam waist along the beam axis. For example, the lens actuator may be provided as a voice coil capable of linearly translating the scan lens 112 along the Z direction. In this case, the scan lens 112 may be formed from a material such as fused silica, optical glass, zinc selenide, zinc sulfide, germanium, gallium arsenide, or magnesium fluoride. 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 offered by COGNEX, VARIOPTIC, etc.) that can be operated (e.g., via a lens actuator) to change the position of the beam waist along the beam axis. By changing the position of the beam waist along the beam axis, the spot size on the workpiece 102 can be changed.

[0054] In embodiments where the device 100 includes a lens actuator, the lens actuator may be connected to the scan lens 112 (for example, to allow the scan lens 112 to move relative to the second positioner 108 within the scan head). Alternatively, the lens actuator may be connected to the scan head 120 (for example, to allow the scan head itself to move when the scan lens 112 and the second positioner 108 move together). In other embodiments, the scan lens 112 and the second positioner 108 are integrated into different housings (for example, so that the housing into which the scan lens 112 is integrated is movable relative to the housing into which the second positioner 108 is integrated).

[0055] F. Controller Generally, the device 100 includes one or more controllers, such as a controller 122, for controlling or facilitating the control and operation of the device 100. In one embodiment, the controller 122 is communicatively connected (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 any combination thereof) to one or more components of the device 100, such as a laser source 104, a first positioner 106, a second positioner 108, a third positioner 110, a lens actuator, a scanning lens 112 (if provided as a variable focal length lens), and fixtures, so that these components operate in response to one or more control signals output by the controller 122.

[0056] 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 perform relative movement between the beam axis and the workpiece, and to generate relative motion between the process spot and the workpiece 102 along a path or trajectory (also referred to herein as the “process trajectory”) within the workpiece 102. It will be understood that any two or all three of these positioners may be controlled so that two positioners (e.g., the first positioner 106 and the second positioner 108, the first positioner 106 and the third positioner 110, the second positioner 108 and the third positioner 110) or three positioners simultaneously generate relative movement between the process spot and the workpiece 102 (thus generating a “composite relative movement” between the beam axis and the workpiece). Of course, it is also possible to control only one positioner (e.g., a first positioner 106, a second positioner 108, or a third positioner 110) to cause a relative movement between the process spot and the workpiece 102 at any given time (thus causing a "non-compound relative movement" between the beam axis and the workpiece).

[0057] In one embodiment, the controller 122 may control the operation of the first positioner 106 to deflect the beam path 114 within the primary angular range 116 in such a way that a composite relative movement or non-composite relative movement occurs between the beam axis and each workpiece 102 (for example, in conjunction with the second positioner 108, or the third positioner 110, or any combination thereof) to cause a relative movement between the process spot and the workpiece 102 along the process trajectory within the workpiece 102. In another embodiment, the controller 122 may control the operation of the first positioner 106 to deflect the beam path 114 within each primary angular range 116 in such a way that it compensates for tracking errors introduced by the second positioner 108.

[0058] Other examples of operations that can be controlled to perform on one or more of the above-mentioned components include those disclosed in U.S. Patents No. 5,751,585, 5,847,960, 6,606,999, 8,680,430, and 8,847,113, or U.S. Patents No. 4,912,487, 5,633,747, 5,638,267, 5,917,300, and 6,3 No. 14,463, 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, As disclosed in U.S. Patent Publications No. 745, 7,834,293, 8,026,158, 8,076,605, 8,288,679, 8,404,998, 8,497,450, 8,648,277, 8,896,909, 8,928,853, and 9,259,802, or in U.S. Patent Publications No. 2014 / 0026351, 2014 / 0196140, and 2 Examples include operations, functions, processes, and methods disclosed in Patent Nos. 014 / 0263201, 2014 / 0263212, 2014 / 0263223, 2014 / 0312013, or in German Federal Patent No. DE102013201968B4, or in International Patent Publication No. WO2009 / 087392, or any combination thereof. Each of these documents is incorporated herein by reference in its entirety.In other examples, the controller 122 may control the operation of any positioner, including one or more AODs (e.g., in one embodiment, a first positioner 106, a second positioner 108, or a combination thereof), for changing the spot shape or spot size of the laser energy beam irradiated onto the process spot (e.g., by chirpening an RF signal applied to one or more ultrasonic converters of one or more AODs, by applying a spectrally shaped RF signal to one or more ultrasonic converters of one or more AODs, or by similar methods, or by any combination thereof), as disclosed in, for example, International Patent Publication WO2017 / 044646A1. The above publication is incorporated herein by reference in its entirety. The applied RF signal may be chirp linearly or nonlinearly in a desired or preferred manner. For example, the applied RF signal may be chirp at a first speed and then chirp at a second speed to diffract the laser energy beam passing through the AO cell in two different ways. In this case, the first speed may be slower or faster than the second speed.

[0059] Generally, the controller 122 includes one or more processors capable of generating the aforementioned control signals when executing instructions. The processors may be provided as programmable processors capable of executing instructions (e.g., one or more general-purpose computer processors, microprocessors, digital signal processors, or any combination thereof). Instructions executable by the processors may be implemented as software, firmware, or in any preferred form of circuitry, including programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), field-programmable object arrays (FPOAs), application-specific integrated circuits (ASICs) (including digital circuits, analog circuits, and mixed analog / digital circuits), or any combination thereof. Instruction execution may occur on a single processor, distributed across multiple processors, in parallel across multiple processors within a single device or across a network of devices, or in similar manner, or in any combination thereof.

[0060] In one embodiment, the controller 122 includes a tangible medium such as computer memory accessible by the processor (e.g., via one or more wired or wireless communication links). As used herein, “computer memory” includes magnetic media (e.g., magnetic tape, hard disk drives, etc.), optical disks, volatile or non-volatile semiconductor memory (e.g., RAM, ROM, NAND flash memory, NOR flash memory, SONOS memory, etc.), and may be locally accessible, remotely accessible (e.g., via a network), or a combination thereof. Generally, instructions may be stored as computer software (e.g., executable code, files, instructions, library files, etc.). Such computer software can be written in, for example, C, C++, Visual Basic, Java, Python, Tel, Perl, Scheme, Ruby, assembly language, hardware description languages ​​(e.g., VHDL, VERILOG, etc.) and can be easily created by those skilled in the art from the descriptions provided herein. Computer software is typically stored in one or more data structures transmitted by computer memory.

[0061] Although not shown in the figures, one or more drivers (e.g., RF drivers, servo drivers, line drivers, power supplies, etc.) may be communicatively coupled to the inputs of 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, and (if provided as a variable focal length lens) the scan lens 112, to control such components. 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, and (if provided as a variable focal length lens) the scan lens 112, can also be considered to include any suitable drivers known in the art. Each driver typically includes an input to which a controller 122 is communicatively coupled, and the controller 122 is capable of generating one or more control signals (e.g., trigger signals). These control signals may be transmitted to the inputs of one or more drivers associated with one or more components of the device 100. Thus, components such as the laser source 104, the first positioner 106, the second positioner 108, the third positioner 110, the lens actuator, and (if provided as a variable focal length lens) the scan lens 112 are configured to respond to control signals generated by the controller 122.

[0062] Although not shown, one or more additional controllers (e.g., component-specific controllers) may, as needed, be communicably connected to the inputs of drivers communicably connected to (and associated with) components such as the laser source 104, the first positioner 106, the second positioner 108, the third positioner 110, the lens actuator, and (if provided as a variable focal length lens) the scan lens 112. In this embodiment, each component-specific controller may be communicably connected to controller 122 and capable of generating one or more control signals (e.g., trigger signals) in response to one or more control signals received from controller 122. These one or more control signals may then be transmitted to the inputs of drivers communicably connected to it. In this embodiment, the component-specific controllers may be operable in the same manner as described with respect to controller 122.

[0063] In other embodiments where one or more component-specific controllers are provided, a component-specific controller associated with a component (e.g., a laser source 104) may be communicatively connected to a component-specific controller associated with another component (e.g., a first positioner 106). In this embodiment, one or more of the component-specific controllers may generate one or more control signals (e.g., trigger signals) in response to one or more control signals received from one or more other component-specific controllers.

[0064] III. Additional discussion on multi-axis AOD systems In many embodiments described 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 can be characterized as a longitudinal-mode AOD or a shear-mode AOD and may be capable of diffracting linearly polarized or circularly polarized laser energy beams. Thus, depending on the wavelength of the laser energy beam and the material forming the AO cells of the AOD in the AOD system, the internal AOD can be directed such that the diffraction axes of the AO cells within the AOD are parallel or perpendicular (or at least substantially parallel or perpendicular) to the plane of polarization of the incident laser energy beam. For example, the wavelength of the laser energy beam may be in the ultraviolet or visible-green region of the electromagnetic spectrum, and the AO cells of the AOD may be formed from a material such as quartz, and the AOD can be directed such that the diffraction axes of the AO cells are perpendicular (or at least substantially perpendicular) to the plane of polarization of the incident laser energy beam. In other examples, if the wavelength of the laser energy beam is in the mid-wavelength infrared or long-wavelength infrared region of the so-called electromagnetic spectrum (i.e., wavelengths ranging from 3 μm (or around) to 15 μm (or around)), and the AOD's AO cell is formed from a material such as crystalline germanium, the AOD can be directed such that the diffraction axis of the AO cell is parallel (or at least substantially parallel) to the polarization plane of the incident laser energy beam.

[0065] With respect to Figure 2, the multi-axis AOD system may be provided as a multi-cell 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 may be provided in the manner described above. The first AOD 202 is positioned and can be operated to rotate an incident laser energy beam (e.g., propagating along beam path 114) by any angle (e.g., measured with respect to beam path 114 incident on the first AOD 202) within a first angular range (also referred to herein as the "first AOD angular range 206") about a first axis of rotation, thereby transmitting a primary beam propagating along the deflected beam path 114'. Similarly, the second AOD204 is positioned and operated to rotate the incident laser energy beam that has passed through the first AOD202 by an arbitrary angle (for example, measured with respect to the beam path 114' incident on the second AOD204) within a second angular range (also referred to in this specification as the "second AOD angular range 208") about a second axis of rotation, thereby transmitting the primary beam propagating along the deflected beam path 114”. To make it clear, beam path 114' and beam path 114” each represent specific examples of paths through which the laser energy beam can propagate. Thus, in this specification, beam path 114' and beam path 114” can also be collectively referred to as "beam path 114".

[0066] Generally, the second AOD204 is oriented relative to the first AOD202 such that its second axis of rotation is different from that of the first axis of rotation. For example, the second axis of rotation may be perpendicular to the first axis of rotation, or it may be oblique to the first axis of rotation. If the diffraction axis of the AOD is perpendicular to the axis of rotation of the AOD, the diffraction axis of the second AOD204 (also called the "second diffraction axis") may be perpendicular to the diffraction axis of the first AOD202 (also called the "first diffraction axis"), or it may be oblique to the diffraction axis of the first AOD202. However, in other embodiments, the second AOD204 is oriented relative to the first AOD202 such that its second axis of rotation is parallel (or at least substantially parallel) to the first axis of rotation. In this case, one or more optical components can be positioned in the beam path 114' such that the deflection plane of the first AOD202 rotates (for example, by 90 degrees or slightly) with respect to the direction of the deflection plane of the second AOD204 when projected onto the second AOD204, and that the deflection plane of the first AOD202 rotates (for example, by 90 degrees or slightly) so that the second diffraction axis is parallel (or at least substantially parallel) to the first diffraction axis. For example, see International Publication WO2019 / 060590A1 for an example of a method by which the deflection plane can be rotated as described above. When the deflection plane of the first AOD202 is rotated by the method described above, the first diffraction axis projected onto the second AOD204 is rotated (for example, by 90 degrees or slightly) with respect to the direction of the second diffraction axis.

[0067] Generally, the AO cell in the first AOD202 is formed from the same or different material as the AO cell in the second AOD204. Furthermore, the type of sound wave used by the first AOD202 to polarize the incident laser energy beam may be the same or different from the type of sound wave used by the second AOD204 to polarize the incident laser energy beam.

[0068] It can be understood that the AOD system 200 may be operated at any given time so that only the first AOD202 generates the primary beam, or only the second AOD204 generates the primary beam, or both the first AOD202 and the second AOD204 generate the primary beam. Therefore, the deflection of the beam path 114 produced by the first positioner 106 can be considered to result from the deflection obtained from beam path 114' alone, or from the deflection obtained from beam path 114'' alone, or from a superposition of the deflections obtained from beam paths 114' and 114''. Similarly, the primary angular range 116 can be considered to be only the first AOD angular range 206, or only the second AOD angular range 208, or a superposition of the first AOD angular range 206 and the second AOD angular range 208. If 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 beam traps, beam expanders, beam shapers, apertures, filters, collimators, lenses, mirrors, phase retarders, polarizers, or any combination thereof.

[0069] IV. Discussion on diffraction efficiency in AOD systems As used herein, the term “diffraction efficiency” means the proportion of energy in the laser energy beam incident on the AOD that is diffracted into the primary beam within the AO cell of the AOD. Thus, diffraction efficiency can be expressed as the ratio of the optical power of the primary beam generated by the AOD to the optical power of the incident laser energy beam incident on the AOD. Generally, 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 as a function of the frequency of the RF drive signal applied to drive the AOD. From this viewpoint, in embodiments in which the first positioner 106 is provided as the AOD system 200 described above, the first RF drive signal applied to drive the first AOD 202 can be characterized as having a certain amplitude (also referred to herein as the “first amplitude”), and the second RF drive signal applied to drive the second AOD 204 can be characterized as having a certain amplitude (also referred to herein as the “second amplitude”).

[0070] Generally, the first amplitude can be selected or set based on one or more factors, such as the first drive frequency of the first RF drive signal, the desired diffraction efficiency when the first AOD202 is driven by the first RF drive signal, the peak optical power of the deflected laser energy beam during the period the first AOD202 is driven by the first RF drive signal, the average optical power of the deflected laser energy beam during the period the first AOD202 is driven by the first RF drive signal, or any combination thereof. Similarly, the second amplitude can be selected or set based on one or more factors, such as the second drive frequency of the second RF drive signal, the desired diffraction efficiency when the second AOD204 is driven by the second RF drive signal, the peak optical power of the deflected laser energy beam during the period the second AOD204 is driven by the second RF drive signal, the average optical power of the deflected laser energy beam during the period the second AOD204 is driven by the second RF drive signal, or any combination thereof.

[0071] V. Embodiments relating to pulse slicing As described above, whether the first positioner 106 is 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 perform pulse slicing, that is, to temporally divide a common laser pulse (also referred to herein as the “mother laser pulse”) into at least two laser pulses. As can be understood, pulse slicing can be thought of as a type of laser pulse.

[0072] One embodiment of pulse slicing is illustrated in Figure 3, in which a mother laser pulse 300 is temporally divided into two pulse slices. Specifically, the mother laser pulse 300 is divided into a first pulse slice 300a during a first slice period p1, and the mother laser pulse 300 is divided into a second pulse slice 300b during a second slice period p2. As can be understood, the pulse duration of a pulse slice generally corresponds to the length of the slice period from which it is temporally divided from the mother laser pulse. For example, the first pulse slice 300a can be characterized as having a pulse duration equal to the first slice period p1, and the second pulse slice 300b can be characterized as having a pulse duration equal to the second slice period p2. Furthermore, as can be understood, the pulse duration of a pulse slice may correspond to the update rate of the first positioner 106 during pulse slicing, an integer multiple of the update rate of the first positioner 106 during pulse slicing, or a combination thereof (for example, equal to or at least substantially equal to this).

[0073] The sequential slicing periods may occur continuously (i.e., one slicing period begins immediately after a preceding slicing period), or intermittently (i.e., one slicing period begins after a delay immediately following a preceding slicing period), or a combination of both. If the sequential slicing periods occur intermittently, it can be understood that the length of the delay can be characterized as an integer multiple of the positioning period of the first positioner 106 (this integer can be any integer such as 1, 2, 3, 4, 5, 10, 20, 50, 100, or a value in between). The embodiment shown in Figure 3 is an example in which the sequential slicing periods p1 and p2 occur intermittently. From the above viewpoint, it can be understood that the pulsed slices output by the AOD system 200 can constitute a laser energy beam having a pulse repetition rate equal to or a multiple of the update rate of the AOD system 200 when the system 200 is operated to perform pulsed slicing.

[0074] The total time applied to a common mother laser pulse from the start of the first slicing period to the end of the last slicing period is less than or equal to the pulse duration of the mother laser pulse (based on the full width at half maximum (FWHM) of the optical power with respect to time). The mother laser pulse can generally be characterized as having a pulse duration longer than the positioning period of the first positioner 106. In some embodiments, the pulse duration of the mother laser pulse is 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 longer than, equal to, or shorter than values ​​in between these.

[0075] In one embodiment, the length of each slice period (and thus the pulse duration of each pulse slice) is an integer multiple of the positioning period of the first positioner 106 (for example, this integer is 1, 2, 3, 5, 10, or a value in between these). In one embodiment, the length of each slice period may be 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 longer than, equal to, or shorter than, values ​​in between these. Generally, the length of one or more slice periods of a mother laser pulse may be the same as, or different from, the length of one or more other slice periods of the same mother laser pulse. For example, Figure 3 shows the first slicing period p1 as being equal to the second slicing period p2, but the length of the first slicing period p1 may be longer or shorter than the second slicing period p2.

[0076] Figure 3 shows that the mother laser pulse 300 is temporally divided into only two pulse slices (i.e., a first pulse slice 300a and a second pulse slice 300b), but it can be seen that the mother laser pulse 300 may be temporally divided into more than two pulse slices (for example, into three pulse slices, five pulse slices, eight pulse slices, ten pulse slices, twenty-five pulse slices, thirty pulse slices, fifty pulse slices, etc., or similar pulse slices, or pulse slices with values ​​in between). Referring to Figure 4, for example, the laser pulse 300 may be temporally divided into four pulse slices 400a, 400b, 400c, and 400d. In one embodiment, the operation of the first positioner 106 is controlled such that the pulse slices in at least one pair of pulse slices that are sequentially divided are deflected within different primary angular ranges 116. For example, pulse slice 400a can be deflected within the primary angle range 116 (e.g., by a first angle only), then pulse slice 400b can be deflected within the primary angle range 116 (e.g., by a second angle only), then pulse slice 400c can be deflected within the primary angle range 116 (e.g., by a third angle only), then pulse slice 400d can be deflected within the primary angle range 116 (e.g., by a fourth angle only). In other embodiments, the operation of the first positioner 106 is controlled such that pulse slices in at least one pair of pulse slices that are subsequently divided are deflected by the same angle within the primary angle range 116.

[0077] Outside of the slicing period, the first positioner 106 can be operated by any method known in the art to attenuate the incident laser energy beam so that when the laser energy beam propagating along the beam path 114 is finally deflected by the first positioner 106, it has insufficient energy to process the workpiece 102. In addition to or instead of this, outside the slicing period, the first positioner 106 can be operated to deflect the beam path 114 toward a beam trap, beam dump system, or any combination thereof. In addition to or instead of this, outside the slicing period, the operation of the first positioner 106 can be stopped so that the incident laser energy beam can be transmitted through the AOD of the first positioner 106 and directed toward a beam trap, beam dump system, or any combination thereof.

[0078] While pulse slicing has been described above in relation to a single mother laser pulse (i.e., laser pulse 300), it can be understood that the first positioner 106 may be operated to perform pulse slicing with respect to a series of mother laser pulses that propagate sequentially. In this series of pulses, the sequentially propagating mother laser pulses may be temporally divided in any desired manner, and two sequentially propagating mother laser pulses may be temporally divided in the same or different manner.

[0079] A. Additional discussion on diffraction efficiency During the slicing period, the first positioner 106 can be operated to attenuate the incident laser energy beam such that the optical power of the pulsed slices becomes constant over time, changes over time, or is 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 changing the amplitude of the RF drive signal supplied to the AOD during the slicing period (e.g., while keeping the frequency of the given RF drive signal constant). Thus, for example, the optical power of the first pulsed slice 300a may be constant or change during the first slicing period p1. Similarly, the optical power of the second pulsed slice 300b may be constant or change during the second slicing period p2.

[0080] The first positioner 106 can be operated to attenuate the incident laser energy beam (for example, by maintaining and / or changing the amplitude of the RF drive signal supplied to the AOD over consecutive slice periods) such that two average optical powers and / or peak optical powers remain constant or change over consecutive slice periods in which a common mother laser pulse is temporally divided into multiple pulse slices. Thus, for example, the average optical power or peak optical power of the first pulse slice 300a during the first slice period p1 may be greater than, equal to, or less than the average optical power or peak optical power of the second pulse slice 300b during the second slice period p2. In another example, the average optical power or peak optical power of pulse slice 400a may be greater than, equal to, or less than the average optical power or peak optical power of any of the pulse slices 400b, 400c, or 400d. The average or peak optical power of pulse slice 400b may be greater than, equal to, or less than the average or peak optical power of either pulse slice 400c or 400d. The average or peak optical power of pulse slice 400c may be greater than, equal to, or less than the average or peak optical power of pulse slice 400d.

[0081] The above discussion regarding the operation of the first positioner 106 is to set or change the optical power of the pulse slice (i.e., to operate the first positioner 106 to perform partial pulse deflection), but it can be seen that the first positioner 106 can be similarly operated to set or change the optical power of the deflection pulse of the laser energy when the first positioner 106 performs full pulse deflection.

[0082] VI. Embodiments relating to beam splitting Figure 1 shows an embodiment in which the laser processing apparatus 100 includes a single second positioner 108, but it will be understood that many of the embodiments disclosed herein can be applied to laser processing apparatuses including multiple (i.e., two or more) second positioners 108. Referring to Figure 31, the laser processing apparatus 3100 may be provided in a similar manner to the laser processing apparatus 100 described above, but may include multiple second positioners (e.g., second positioners 108a and 108b, each collectively referred to as “second positioner 108”) and multiple scan lenses (e.g., scan lenses 112a and 112b, each collectively referred to as “scan lens 112”). Similar to the laser processing apparatus 100, the scan lenses 112 and the corresponding second positioners 108 may be integrated into a common housing or “scan head” as needed. Therefore, the scan lens 112a and the corresponding second positioner 108 (i.e., the second positioner 108a) can be integrated into a common scan head 120a. Similarly, the scan lens 112b and the corresponding second positioner 108 (i.e., the second positioner 108b) can be integrated into a common scan head 120b. As used herein, each of the scan heads 120a and 120b is also collectively referred to as "scan head 120".

[0083] If the first positioner 106 is integrated into the laser processing apparatus 3100, the first positioner 106 may be capable of diffracting, reflecting, refracting, or deflecting the laser energy beam in order to deflect the beam path 114 towards one of the second positioners 108. When deflecting the beam path 114 to the second positioner 108a, the beam path 114 can be deflected at any angle within the first angular range (also referred to herein as the "first primary angular range 116a") (for example, this is measured relative to the beam path 114 incident on the first positioner 106). Similarly, when deflecting the beam path 114 to the second positioner 108b, the beam path 114 can be deflected at any angle within the second angular range (also referred to herein as the "second primary angular range 116b") (for example, this is measured relative to the beam path 114 incident on the first positioner 106). As used herein, the first primary angular range 116a and the second primary angular range 116b are collectively referred to herein as the "primary angular range 116". Generally, the first primary angular range 116a does not overlap with or touch the second primary angular range 116b. The first primary angular range 116a may be greater than, less than, or equal to the second primary angular range 116b. As used herein, deflecting the beam path 114 within one or more primary angular ranges of the primary angular range 116 is referred to as "beam splitting".

[0084] In one embodiment, the operation of the first positioner 106 may be controlled to deflect the beam path 114 to the second positioner 108a (for example, during the first branching period) and to deflect the beam path 114 to the second positioner 108b (for example, during the second branching period after the first branching period), or vice versa, or a combination thereof. In other examples, the operation of the first positioner 106 may be controlled to deflect the beam path 114 to both the second positioner 108a and the second positioner 108b simultaneously. In the embodiments described herein, the length of the first branching period may be longer than, shorter than, or equal to the length of the second branching period. The lengths of the first branching period and the second branching period, respectively, may be longer than, shorter than, or equal to the positioning period of the first positioner 106. In one embodiment, the lengths of the first branching period and the second branching period can be characterized as integer multiples of the positioning period of the first positioner 106 (this integer may be an integer such as 1, 2, 3, 4, 5, 10, 20, 50, 100, or any integer between these values). See the following section for a further explanation of the “positioning period” of the first positioner 106. In one embodiment, the length of each branching period may be 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 longer than, shorter than, or equal to any of these values.

[0085] When the laser energy beam output by the laser source 104 is represented as a series of laser pulses, each branching period may have a duration longer than or equal to the pulse duration of the laser pulse in the laser energy beam. However, in other embodiments, one or more branching periods may have a duration shorter than the pulse duration of the laser pulse in the laser energy beam. In such embodiments (or embodiments in which the laser energy beam output by the laser source 104 is represented as a continuous or semi-continuous laser beam), beam branching results in pulse slicing, which can generate one or more pulse slices.

[0086] VII. Feature Formation Generally, regardless of whether it is provided in the laser processing apparatus described with respect to Figure 1 or Figure 31 or any other laser processing apparatus, the first positioner 106 can be operated and used to rapidly scan or position process spots within a first scan range (as described above, for example) in order to form features (e.g., openings, vias, trenches, slots, scribe lines, recesses, etc.) within the workpiece 102. In some embodiments, the workpiece 102 may be provided as a PCB panel, PCB, FPC, IC, ICP, semiconductor device, etc. Thus, the workpiece 102 may include one or more constituent structures such as conductive structures (e.g., films, foils, etc. that may be formed from copper, copper alloys, etc., wiring or conductive wire structures containing one or more metals such as copper, titanium, titanium nitride, tantalum, etc., or any combination thereof), dielectric structures (e.g., build-up films, glass fiber reinforced epoxy laminates, interlayer dielectric materials, low-k dielectric materials, solder resists, polymer materials, etc., or any combination thereof), or any combination thereof. The conductive or dielectric structure of the workpiece 102 can have a thickness ranging from 5 μm (or around that) to 500 μm (or around that). Thus, the thickness of the conductive 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, or any value between these values.

[0087] In one embodiment, referring to Figure 5, the workpiece 102 includes a dielectric structure 500 that contacts or is attached to the first conductive structure 502 on its first surface side. The dielectric structure 500 is provided as a material such as FR4, polyimide, liquid crystal polymer, or ABF, and may have a thickness (t1) in the range of 15 μm (or around) to 120 μm (or around). The first conductive structure 502 may be provided as a copper or copper alloy foil that is treated, for example, by a chemical reaction or by a laser darkening process to increase the absorption of laser energy, or may have an undarkened exposed surface. A second conductive structure 504 (e.g., a pad, trace, foil, etc. formed of copper or a copper alloy) may contact or be attached to a second surface of the dielectric structure 500 opposite to the first surface. The first conductive structure 502 may have a thickness (t2) equal to (or approximately equal to) a value between 5 μm, 7 μm, 9 μm, 12 μm, 18 μm, 35 μm, 70 μm, 105 μm, etc. If a second conductive structure is present, the second conductive structure may have a thickness (t3) that is less than, greater than, or equal to the thickness (t1) of the first conductive structure 502. If necessary, the workpiece 102 may include one or more additional structures, such as the additional dielectric structure 508 partially shown in Figure 5, which the second conductive structure 504 contacts or is attached to the second conductive structure 504 (for example, such that the second conductive structure 504 is located between the dielectric structure 500 and the dielectric structure 508).

[0088] Generally, features (e.g., openings, vias, trenches, slots, scribe lines, recesses, etc.) can be characterized as being formed by ablation, which removes material from one or more constituent structures of the workpiece 102. Unless otherwise explicitly stated, the term “ablation” may mean “direct ablation,” “indirect ablation,” or any combination thereof. Direct ablation of material within the workpiece 102 occurs when the primary cause of ablation is the decomposition of the material due to its absorption of energy in the irradiated laser energy beam (e.g., linear absorption, nonlinear absorption, or any combination thereof). Indirect ablation (also known as “lift-off”) of the target material within the workpiece 102 (e.g., the first conductor) occurs when the primary cause of ablation is melting and evaporation due to heat transferred from adjacent material that absorbs energy in the laser energy beam that ultimately irradiates the workpiece 102. The removal of the target material (e.g., the first conductor 502) occurs when the pressure in the pocket of evaporated material between the target material and the adjacent material (e.g., generated during the evaporation of the adjacent material) is sufficient to eject the target material from the workpiece 102. Considerations regarding material removal by indirect ablation are known in the art and are described in more detail in International Publication WO2017 / 044646A1.

[0089] A. Feature generation using scan patterns To form features such as vias in the workpiece 102 (for example, configured as described above) (e.g., the non-penetrating via 600 illustrated in Figure 6 and the penetrating via 700 illustrated in Figure 7), the first positioner 106 may be provided as a multi-axis AOD system (e.g., AOD system 200) and may be operated to scan process spots (i.e., spots on the workpiece 102 to which a laser energy beam directed towards the workpiece 102 is irradiated, as indicated by arrow 506 in Figure 5) along a process trajectory that defines a scan pattern. If the laser energy beam irradiated onto the workpiece 102 is represented as multiple pulses, the scan pattern may be characterized as a pattern of spot locations distributed within the region of the workpiece 102 where features (e.g., vias) are formed. During feature formation, the first positioner 106 may be operated to achieve full pulse deflection, partial pulse deflection, or a combination of full and partial pulse deflection (e.g., as described above).

[0090] Generally, the maximum dimension of a scan pattern (measured in the XY plane) is less than or equal to the maximum dimension of a first scan region (measured in the XY plane). Furthermore, the spot size of a process spot scanned along the scan pattern used to form a via is less than the maximum dimension (measured in the XY plane) of the via itself (formed in the first conductive structure 502). Therefore, the maximum dimension of a via can be equal to (or approximately equal to) a value between 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, etc. The maximum dimensions (measured in the XY plane) of a via formed in the dielectric structure (for example, at the bottom of a via, or at or near the interface between the dielectric structure and the second conductive structure) may be greater than, less than, or equal to the maximum dimensions of a via formed in the first conductive structure 502.

[0091] The characteristics of the scan pattern may include the number of spot positions in the scan pattern, the arrangement of spot positions in the scan pattern, the order or sequence in which spot positions are specified in the scan pattern, and the distance between consecutively specified spot positions. Generally, a spot position is specified when a single laser pulse or a set of consecutively emitted laser pulses irradiates the workpiece 102 at the spot position. According to the embodiments described herein, one or more of these scan pattern characteristics can be selected or set, taking into account one or more of the above characteristics of the laser energy beam irradiated onto the workpiece 102 (e.g., wavelength, average power, pulse duration, pulse repetition rate, pulse energy, peak power, temporal optical power profile, spot size, etc.), so that the laser energy can be distributed uniformly (or at least somewhat uniformly) over the area of ​​the workpiece 102 where vias are formed before the first conductive structure 502 is finally ablated (by indirect ablation or a combination of direct and indirect ablation). By doing so, the region of the first conductive structure 502 on which vias are formed can be heated uniformly (or at least somewhat uniformly) to the processing threshold temperature or near thereto of the first conductive structure 502 before all spot positions in the scan pattern are specified. For this reason, according to embodiments described herein, the process of forming vias in the workpiece 102 can be characterized as including a process of forming an opening in the first conductive structure 502. This is done by first specifying a number of spot positions in the scan pattern to heat the region of the first conductive structure 502 on which openings are formed uniformly (or at least somewhat uniformly) to the processing threshold temperature or near thereto of the first conductive structure 502, and then specifying one or more other spot positions in the scan pattern to evaporate a portion of the dielectric structure 500 below the heated region of the first conductive structure 502 and eject the heated region of the first conductive structure 502 from the workpiece 102 (i.e., by indirect ablation), thereby forming an opening in the first conductive structure 502.

[0092] From the above perspective, it will be understood that, in addition to the characteristics of the laser energy beam (e.g., average power, pulse duration, pulse repetition rate, pulse energy, peak power, spot size, or any combination thereof), one or more of the scan pattern characteristics described above can be selected or set so that all (or at least substantially all) of the portion of the first conductive structure 502 located within the region of the workpiece 102 where vias are formed (including the region of the first conductive structure 502 located in the center of the region of the workpiece 102 where vias are formed (hereinafter also referred to as the "central region of the first conductor 502")) is melted before the first conductive structure 502 is ablated (e.g., by indirect ablation). However, the scan pattern characteristics, the characteristics of the laser energy beam, or one or more of these can be modified so that, before the first conductive structure 502 is ablated, the central region of the first conductor 502 is not melted, but the portion of the first conductor 502 surrounding the central region is melted. In this case, the unmelted central region of the first conductor 502 can still be removed by indirect ablation (for example, during evaporation of the dielectric structure below the unmelted central region of the first conductor 502).

[0093] Furthermore, one or more scan pattern specifications can be selected or set, taking into account the rate at which consecutively specified spot positions in the scan pattern are specified. The rate at which different spot positions in the scan pattern are specified may be equal to (or at least substantially equal to) the update rate of the first positioner 106 during via formation, an integer multiple of the update rate of the first positioner 106 during via formation, or a combination thereof. Thus, the rate at which different spot positions in the scan pattern are specified may correspond to the update rate of the first positioner 106 during via formation. For this reason, the total time required to scan the process spots along the scan pattern (also referred to herein as "exposure time") may correspond to the product of the number of spot positions in the scan pattern multiplied by the first positioning period of the first positioner 106 (when operating the first positioner 106 to scan the process spots along the scan pattern).

[0094] As described above, during the via formation process, laser energy is distributed uniformly (or at least somewhat uniformly) across the region of the workpiece 102 where the vias are formed, before the first conductive structure 502 is ablated (for example, by direct ablation, indirect ablation, or a combination thereof). Therefore, at least two spot positions of the scan pattern (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.) are designated before the first conductive structure 502 is ablated. For example, a simulation performed by the inventors showed that when a laser energy beam, represented as a series of laser pulses (i.e., having wavelengths such as 9.4 μm or 10.6 μm, a spot size of 70 μm, a pulse duration of 1 μs, and a peak power of up to approximately 1.3 kW), is irradiated onto a workpiece 102 provided as a PCB having a dielectric structure formed from 50 μm thick FR4, a first conductive structure 502 formed from 12 μm thick copper foil treated to increase laser energy absorption, and a second conductive structure formed from 35 μm thick copper foil, the ablation of the first conductive structure 502 begins within a period of 6 μs to 8 μs (or around that) after the process spot is first scanned. Therefore, according to this simulation, approximately 6 to 8 spot positions can be designated by the laser energy beam before the first conductive structure 502 is ablated.

[0095] i. Example of a scan pattern embodiment The scan patterns shown in Figures 8 to 22 and Figure 24(a) are described below. These were performed by the inventors to form circular (or at least generally circular) non-penetrating vias on the workpiece 102 (provided, for example, as described above) by irradiating the workpiece 102 with a laser energy beam having a wavelength in the range of 9 μm (or around) to 11 μm (or around) (e.g., wavelengths such as 9.4 μm (or around), 10.6 μm (or around)), a peak power in the range of 250 W (or around) to 2 kW (or around) and a spot size in the range of 60 μm (or around) to 90 μm (or around). However, it will be understood that the spot size may be smaller than 60 μm, for example, in the range of 30 μm (or around) to 60 μm (or around). Therefore, process spots scanned along the exemplary scan patterns described below may have spot sizes of, for example, 40 μm (or around), 50 μm (or around), 70 μm (or around), or 85 μm (or around), or values ​​in between these values. Generally, the pulses in the laser energy beam irradiated onto the workpiece 102 have a pulse duration of 1 μs (or around). However, it will be understood that the scan patterns described below may be used to form features other than non-through vias (e.g., through via trenches, slots, or other recesses or openings), and the scan patterns may be modified to form features other than vias.

[0096] Furthermore, assuming that other characteristics of the laser energy beam irradiated onto the workpiece 102 (e.g., pulse duration, pulse repetition rate, peak power, temporal optical power profile, fluence, etc.) are sufficient for processing the workpiece 102, it can be understood that the laser energy beam irradiated onto the workpiece 102 may have a wavelength of 9 μm or less (e.g., the ultraviolet or green region of the electromagnetic spectrum). For example, the laser source 104 may be provided as a laser such as the ULR / ULM-355-200 series lasers manufactured by IPG PHOTONICS. These lasers are high-power QCW fiber lasers capable of generating a laser energy beam with a wavelength of 355 nm and an average power of 200 W. This beam consists of laser pulses output with a pulse duration of approximately 1.4 ns and a pulse repetition rate of 80 MHz. In another example, the laser source 104 may 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.). This laser can operate in pulsed mode or QCW mode and can generate a laser energy beam with a wavelength of 532 nm and an average power of 200 W or more. This beam consists of laser pulses output with a pulse duration of approximately 1.2 ns and a pulse repetition rate of approximately 50 MHz or more.

[0097] Finally, it will be understood that regardless of the wavelength of the laser energy beam irradiated onto the workpiece 102, the laser energy beam irradiated onto the workpiece 102 may have any suitable or desired characteristics (e.g., spot size, pulse duration, peak power, pulse energy, average power, pulse repetition rate, etc.) based on one or more factors such as the material composition of the workpiece 102 being processed, acceptable quality, and throughput criteria.

[0098] In Figures 8 to 22 and Figure 24(a), the spot locations of the scan pattern are distributed in a circular arrangement (for example, on or along the common perimeter of a virtual circle). In these figures, the center of each spot location is indicated by a dot or circle. The horizontal and vertical axes shown are for reference only, and the numbers on each axis indicate distance or position (measured in μm). Therefore, the scan patterns shown in Figures 8 to 22 and Figure 24(a) can be characterized as having radii ranging from 10 μm (or around) to 60 μm (or around).

[0099] In one embodiment, the scan pattern used to form vias may be an adjacent farthest-to-next-spot scan pattern. In an adjacent farthest-to-next-spot scan pattern, the designated second or subsequent spot location is located as far away as possible from any previously designated spot location. Examples of adjacent farthest-to-next-spot scan patterns are shown in Figures 8 and 9.

[0100] Referring to Figure 8, the adjacent furthest scanning pattern consists of eight spot positions (the center of each spot position is represented by a point such as point 800), and each spot position is specified only once. As illustrated illustrative, the eight spot positions are arranged in a circular configuration (e.g., on or along the common perimeter of a virtual circle). The lines connecting the spot positions and the numbers "1", "2", ... "8" near the spot positions indicate the order in which the spot positions in the scanning pattern 800 are specified (e.g., by the laser energy beam deflected at least by the first positioner 106). Thus, spot position 1 is the first spot position specified in the scanning pattern 800, spot position 2 is the second spot position specified in the scanning pattern 800, and so on, with spot position 8 being the last spot position specified in the scanning pattern 800.

[0101] Referring to Figure 9, the adjacent furthest scanning pattern consists of 16 spot positions arranged in a circular pattern (for example, on or along the common perimeter of a virtual circle). In the scanning pattern shown in Figure 9, each spot position overlaps with another spot position. Therefore, the identifiers "1,12", "2,11", "3,9", ... "5,16" for each section of the point indicate the spot positions, and the lines connecting the spot positions indicate the order in which the spot positions in the scanning pattern are designated (for example, by a laser energy beam deflected at least by the first positioner 106). Thus, in the scanning pattern shown in Figure 9, the points indicated by "1,12" represent the positions of the first and twelfth spot positions designated in the scanning pattern 800, the points indicated by "2,11" represent the positions of the second and eleventh spot positions designated in the scanning pattern, and so on.

[0102] It will be understood that adjacent farthest scanning patterns can be modified (for example, so that the second or subsequent spot location to be designated is not as far away as possible from any previously designated spot location) to still be suitable for use in forming vias. Examples of modified adjacent farthest scanning patterns are shown in Figures 10 to 22. The scanning patterns shown in Figures 10 to 22 (in addition to the scanning patterns shown in Figures 8 and 9) can generally be characterized as one of two types. In the first type of scanning pattern (also referred to herein as the “first type scanning pattern”), the midpoints between pairs of consecutively designated spot locations are located in the same place (e.g., the center of a virtual circle). In the second type of scanning pattern (also referred to herein as the “second type scanning pattern”), the midpoints between pairs of consecutively designated spot locations are not located in the same place. Figures 8 to 16, Figures 20 to 22, and Figure 24(a) show examples of first type scanning patterns, and Figures 17 to 19 show second type scanning patterns.

[0103] Type 2 scan patterns can be characterized as scan patterns in which adjacent spot positions are specified continuously (for example, as shown in Figures 17 and 19), or as scan patterns in which adjacent spot positions are not specified continuously (for example, as shown in Figure 18). Scan patterns like those shown in Figures 17 and 19 are called "continuously specified Type 2 scan patterns," and scan patterns like those shown in Figure 18 are called "non-continuously specified Type 2 scan patterns."

[0104] In Figures 17 and 19, spot positions 1 and 2 are examples of adjacent and consecutively designated spot positions. In Figure 18, spot positions 1 and 7 are examples of adjacent but not consecutively designated spot positions. Rather, in Figure 18, spot positions 1 and 2 are not adjacent but are consecutively designated. In the example scan pattern shown in Figure 18, spot position 7 is located between spot positions 1 and 2, which are consecutively designated (for example, along the circumference of a virtual circle). Also, as shown in Figure 18, spot positions 12 and 1 are located between spot positions 6 and 7, which are consecutively designated (for example, along the circumference of a virtual circle). It can be seen that the scan patterns shown in Figures 17 to 19 can be modified so that any number of spot positions can be located between any two consecutively designated spot positions within the same scan pattern (for example, along the circumference of a virtual circle).

[0105] The scan pattern examples shown in Figures 8 to 22 and Figure 24(a) are shown to have a predetermined number of spot positions (e.g., 4, 8, 12, 16, 18, or 20 spot positions) arranged on or along the common perimeter of a virtual circle. However, it will be understood that any scan pattern (whether illustrated or not) can have a different number of spot positions (e.g., 2, 3, 5, 6, 10, 15, 22, 25, 28, 30, 32, 40, 50, 60, 70, 75, 80, 100, etc., or any value between these) arranged on or along the common perimeter of a virtual circle, and that the spot positions may be specified in any preferred or desired order or sequence. For example, the scan pattern examples shown in Figures 8, 10 to 13, and 15 to 20 are shown to have multiple spot locations that are specified sequentially only once, but it will be understood that any spot location in these scan patterns may be specified sequentially multiple times (e.g., two, three, four, five times, etc.). It will also be understood that spot locations within a common scan pattern may be placed on or along other lines, edges, line segments, etc., that draw any desired or preferred shape (e.g., triangles, squares, rectangles, hexagons, ellipses, stars, etc., or any combination thereof).

[0106] When scanning process spots along a Type 2 scan pattern such that non-adjacent spot locations are specified consecutively, any number of spot locations may lie between pairs of consecutively specified spot locations (for example, along the circumference of a virtual circle). The number of spot locations that may lie between such pairs of consecutively specified spot locations can range from 3 to 10 spot locations (for example, from 4 to 6 spot locations).

[0107] ii. Additional discussion on feature shape distortion It has been found that vias generated by operating a first positioner 106 (e.g., a multi-axis AOD system such as AOD system 200) to scan process spots along the second type scan pattern described above may have elliptical openings (on the surface of workpiece 102), for example, as shown in Figure 27, even if the spot positions in the second type scan pattern are arranged on or along the common circumference of a virtual circle, for example, as shown in Figure 28. To compensate for this distortion in the shape of the via openings, the arrangement of spot positions in the second type scan pattern can be modified (for example, as shown in Figure 29, as the spot positions are arranged on or along the common circumference of a virtual ellipse). The modified second type scan pattern shown in Figure 29 can generally be characterized as having an elliptical shape. The major axis of this elliptical shape is orthogonal to the major axis of the via opening shape shown in Figure 27. Any second type scan pattern (including the second type scan pattern described above) can be modified so that the spot positions are arranged on or along the circumference of a common ellipse rather than on or along the circumference of a common circle. When the process spot is scanned along such a modified scan pattern, the resulting via opening will have a more circular shape compared to the elliptical shape shown in Figure 27.

[0108] iii. Additional discussion on scan patterns, via roundness, and pulse slicing It should be noted that in Figures 8 to 22 and Figure 24(a), the horizontal and vertical axes do not necessarily represent the direction of the diffraction axis of the AOD in a multi-axis AOD system (e.g., AOD system 200) operating to scan process spots along a scan pattern to form vias. Generally, process spots can be scanned along any scan pattern as described herein while operating the AOD system 200 to perform full pulse deflection, partial pulse deflection (i.e., pulse slicing) (as described above), or a combination thereof. When operating a multi-axis AOD system (e.g., AOD system 200) to perform partial pulse deflection, it has been found that the roundness of the final via opening may depend on one or more factors such as the direction of the scan pattern (i.e., the direction of the "jumps" between continuously specified spot positions in the scan pattern relative to the direction of the diffraction axis of the AOD in the multi-axis AOD system), the distance between continuously specified spot positions in the scan pattern, and the update rate of the multi-axis AOD system while the process spots are being scanned. While not wishing to be bound by any particular theory, the inventors believe that when the RF drive frequency supplied to the AOD is changed while the laser pulse passes through the AOD's AO cell during pulse slicing, the resulting sonic transient changes within the AO cell cause the incident laser energy beam to diffract in an undesirable manner. This diffraction phenomenon caused by sonic transient changes can sometimes produce unacceptable distortion of the process spot on the workpiece 102. It has been observed that the distortion of the process spot is most severe when the difference in the RF drive frequency supplied to a particular AOD is large between two consecutive first positioning periods of the AOD. It has also been observed that operating multiple AODs in a multi-axis AOD system to continuously specify different spot positions within the scan pattern can reduce the distortion of the process spot to some extent.

[0109] For example, in the scan pattern shown in Figure 14, 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 a multi-axis AOD system (e.g., the first diffraction axis of the first AOD 202 in 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 a multi-axis AOD system (e.g., the second diffraction axis of the second AOD 204 in AOD system 200). Therefore, the distance between consecutively designated spots aligned in diagonal directions (each parallel to the diffraction axis of the AOD in a multi-axis AOD system such as AOD system 200) is longer than the distance between consecutively designated spots aligned horizontally or vertically as shown in the figure. Therefore, when process spots are scanned along the scan pattern shown in Figure 14, the shape of the process spots on the workpiece 102 may be distorted, resulting in via openings with relatively low circularity (for example, as shown in Figure 23). However, by rotating the direction of the scan pattern shown in Figure 14 with respect to the AOD diffraction axis in a multi-axis AOD system (for example, by 45 degrees as shown in Figure 24(a)) so that the direction of relatively large "jumps" (i.e., 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 any of the AOD diffraction axes, the circularity of the resulting via openings can be improved as shown in Figure 24(b). As shown in Figure 14, only a single AOD is operated to scan process spots 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).However, as shown in Figure 24(a), multiple AODs must be operated to scan the process spot 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. Similarly, the direction of the "jumps" between the continuously specified spot positions in the scan pattern shown in Figure 16 is not parallel to any of the diffraction axes of any of the AODs in the multi-axis AOD system. As a result, when scanning the process spot along the scan pattern shown in Figure 16, the resulting vias have apertures with relatively high roundness (e.g., as shown in Figure 25).

[0110] Note that within the AOD, each given RF drive frequency corresponds to the effective phase gradient applied to the incident laser energy beam. In particular, the phase gradient (in μradians) can be calculated as follows.

number

[0111] For example, the direction of the "jump" between spot positions 1 and 2 in the scan pattern shown in Figure 8 is parallel to one diffraction axis of the AOD (e.g., the first diffraction axis of the first AOD202 in 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 AOD204 in AOD system 200). Therefore, the longest jump achievable by a single AOD is equal to a slope of approximately 300 μradians, which corresponds to a phase slope of approximately 4.5 μm across the diameter of the laser energy beam passing through the AOD (which can be approximately 15 mm, or approximately 50% of its 9.4 μm wavelength). Thus, the jumps from spot position 1 to spot position 2 and from spot position 3 to spot position 4 are relatively large jumps.

[0112] When the AOD system 200 is operated to perform partial pulse deflection to scan process spots along the scan pattern shown in Figure 8 at an update rate of 1 MHz (corresponding to a first positioning period of 1 μs), vias with acceptablely rounded openings can be formed. However, when the update rate is doubled to 2 MHz (corresponding to a first positioning period of 0.5 μs), the process spots become distorted as they were scanned along the scan pattern shown in Figure 8, forming vias with openings that are more square-like in shape. In contrast, the jump distances between continuously specified spot positions in scan patterns such as those shown in Figures 17 to 19 can be much shorter than the jump distances between continuously specified spot positions in scan patterns such as the one shown in Figure 8. For example, the jumps between continuously specified spot positions in the scan pattern shown in Figure 19 can be less than 10 μm (less than three times that of the scan pattern shown in Figure 8). As a result, when the AOD in a multi-axis AOD system is driven at a refresh rate of 2 MHz, and even when driven at a refresh rate of 8 MHz (corresponding to a first positioning period of 0.125 μs), the distortion of process spots on the workpiece 102 can be very small.

[0113] From the above perspective, the number of spot positions having a relatively large number (e.g., 40 or more) (e.g., 45, 50, 60, 75, 80, 90, 100, 124 spot positions, or a number of spot positions between any of these values) is such that the continuously specified spot positions are spatially separated by up to 6 spot positions, and / or the distance between jumps in the continuously specified spot positions is less than 15 μm (e.g., 13 μm, 11 μm, 10 μm, 9 μm, 8 μm, 7 μm, etc., or a number of spot positions between any of these values). Vias can be formed (for example, on the workpiece 102 described above) by operating the first positioner 106 (e.g., a multi-axis AOD system such as AOD system 200) at an update rate higher than 1 MHz (e.g., 2 MHz, 5 MHz, 8 MHz, 12 MHz, 25 MHz, 50 MHz, or an update rate greater than or equal to any of these values) to scan process spots (e.g., having spot sizes within the range described above) along a type 2 scan pattern (e.g., provided by any method described herein).

[0114] iv. Additional discussion on localized heat storage Depending on one or more factors such as the wavelength, pulse duration, pulse repetition rate, and average power of the laser pulse irradiated onto the workpiece 102, the linear absorption of the material at the spot location (for example, with respect to the wavelength of the laser pulse irradiated onto the spot location), the thermal conductivity, thermal diffusivity, and specific heat capacity of the material at or near the spot location, the scan pattern along which the process spot is scanned, or any combination thereof, the heat generated as a result of irradiating one or more spot locations with a laser pulse may diffuse from the irradiated spot location and accumulate in the region of the workpiece 102 outside the process spot, causing the temperature of the workpiece 102 in the region outside the process spot to rise.

[0115] The accumulated heat will raise the temperature of the area of ​​the workpiece 102 located at or near the spot where the process spot is irradiated, and if this temperature rise exceeds a threshold temperature (i.e., the "processing threshold temperature"), it can have a positive effect on the efficiency of subsequent processing of the workpiece 102 (e.g., by direct ablation, indirect ablation, or any combination thereof). Generally, the processing threshold temperature associated with the material being processed is above the melting point or glass transition temperature of the material being processed, but below its vaporization temperature. However, in other embodiments, the processing threshold temperature may be lower than the melting point or glass transition temperature of the material being processed (e.g., 98%, 95%, 93%, 90%, 89%, 87%, 85%, 80%, 75%, 70%, 65%, 50%, 40%, etc., or any value between these values).

[0116] In some cases, accumulated heat can raise the temperature in areas of workpiece 102 that are not intended to be processed (each of which is also referred to herein as a “non-feature area” of workpiece 102). If the temperature is sufficiently high, the non-feature areas of workpiece 102 may be susceptible to undesirable damage (e.g., undesirable scratching, melting, delamination, or annealing). Thus, it may be preferable to process workpiece 102 in a way that avoids the accumulation of undesirable heat in the non-feature areas of workpiece 102. As used herein, the temperature at which an area of ​​workpiece 102 is susceptible to undesirable damage is referred to as the “damage threshold temperature.” It should be understood that the damage threshold temperature of any non-feature area of ​​workpiece 102 may depend on one or more factors, such as the thickness, thermal conductivity, thermal diffusivity, specific heat capacity, and absorbance (to the irradiated laser energy beam) of the material at or near the spot location or in the non-feature area, as well as the thermal conductivity, thermal diffusivity, specific heat capacity, size, and dimensions of structures located near the non-feature area, or any combination thereof.

[0117] a. Avoid undesirable damage It has been found that when forming non-penetrating vias 600 in the workpiece 102 by scanning the laser energy beam (for example, along the scan patterns exemplified above with respect to Figures 8 to 29 or other scan patterns) (for example, as described above with respect to Figures 5 and 6), the workpiece 102 may delaminate in layers. Examples of regions in which the workpiece 102 may delaminate in layers include the peripheral region of the exposed second conductive structure 504 or its vicinity (for example, within the region specified by circle "A"), the interface region between the second conductive structure 504 and one or both of the dielectric structure 500 and the dielectric structure 508, the central region of the exposed second conductive structure 504 or its vicinity (for example, within the region specified by circle "B"), and any combination thereof. Experiments conducted by the applicant suggest that delamination occurs when the laser pulse irradiated onto the workpiece 102 has a relatively high peak power. As the process of forming the non-penetrating via 600 nears completion, the irradiated laser pulses heat the second conductive structure 504 to a considerable extent, and this heat is transferred from the second conductive structure 504 to non-feature regions (for example, within the regions specified by circles "A" and / or "B") of the dielectric structure 500 and / or dielectric structure 508 adjacent to the heated second conductive structure 504. The accumulated heat can raise the temperature of the adjacent regions of the dielectric structure 500 above its glass transition temperature (and possibly above its thermal decomposition temperature), causing delamination within the workpiece 102 or making the workpiece 102 more susceptible to delamination.

[0118] To prevent delamination during the process of forming the non-penetrating via 600, the applicant discovered that as the process nears its end, the peak power of the laser pulses irradiating the workpiece 102 can be lower than the peak power of the laser pulses irradiating the workpiece 102 earlier. It was found that the combination of lowering the peak power of the irradiated laser pulses and spatially distributing the irradiated laser pulses (for example, along the scan patterns exemplified above with respect to Figures 8 to 29) prevents the second conductive structure 504 from heating to a considerable extent, thus preventing an undesirable accumulation of heat in the adjacent region of the dielectric structure 500 that could contribute to delamination.

[0119] For example, referring to Figure 30, multiple laser pulses irradiated onto the workpiece 102 to form non-penetrating vias 600 may be provided as pulse slices temporally divided by a first positioner 106 from a common mother laser pulse 3000. The pulse slices may be scanned along any preferred or desired scan pattern (e.g., as exemplified above with respect to Figures 8 to 29, or otherwise). The mother laser pulse 3000 may have a wavelength in the range of 9 μm (or around) to 11 μm (or around) (e.g., wavelengths such as 9.4 μm (or around), 10.6 μm (or around)) and a peak or average power in the range of 250 W (or around) to 2 kW (or around).

[0120] In this case, the pulse slices may include a first pulse slice 3002 and a second pulse slice 3004. Multiple first pulse slices 3002 are irradiated onto the workpiece 102 during a first period (for example, this may be the total period from the start of the first slice period p1 to the end of the mth slice period pm), and then multiple second pulse slices 3004 are irradiated onto the workpiece 102 during a second period (for example, this may be the total period from the start of the m+1th slice period pm+1 to the end of the nth slice period pn). Although Figure 30 illustrates only two first pulse slices 3002 (corresponding to slice periods p1 and pm), it can be understood that any number of first pulse slices 3002 may be temporally divided from the mother laser pulse 3000 between the first slice period p1 and the mth slice period pm. Similarly, although Figure 30 illustrates only two second pulse slices 3004 (corresponding to slice periods pm+1 and pn), it can be understood that any number of second pulse slices 3004 may be temporally divided from the mother laser pulse 3000 between the (m+1)th slice period pm+1 and the nth slice period pn. The continuous slice periods in which pulse slices are temporally divided from the mother laser pulse 3000 during the first period may be continuous, intermittent, or a combination thereof, as described above. Similarly, the continuous slice periods in which pulse slices are temporally divided from the mother laser pulse 3000 during the second period may occur continuously, intermittently, or a combination thereof, as described above. Furthermore, although Figure 30 illustrates that the m-th slice period pm and the (m+1)th slice period pm+1 occur intermittently (i.e., a delay intervenes after the m-th slice period pm and before the (m+1)th slice period pm+1), it can be understood that the m-th slice period pm and the (m+1)th slice period pm+1 may also occur continuously (i.e., the (m+1)th slice period pm+1 begins immediately after the m-th slice period pm).

[0121] A first pulse slice 3002 can be characterized as having a substantially constant first optical power P1, and a second pulse slice 3004 can be characterized as having a substantially constant second optical power P2 that is lower than the first optical power P1. Generally, as described above, the optical power of a pulse slice can be set (for example, to the first optical power P1 or to the second optical power P2) by maintaining or changing the amplitude of the RF drive signal supplied to the AOD during each slice period. In one embodiment, the first optical power P1 may be in the range of 150 W (or around) to 300 W (or around) (e.g., 200 W or around). The second optical power P2 may be in the range of 75% to 25% of the first optical power P1 (e.g., 50% or around).

[0122] The laser pulses ultimately irradiated onto the workpiece during the formation of the non-penetrating via 600 may have a spot size in the range of 60 μm (or approximately) to 90 μm (or approximately). However, it will be understood that the spot size may be smaller than 60 μm, for example, in the range of 30 μm (or approximately) to 60 μm (or approximately). For this reason, process spots scanned along the exemplary scan patterns described below may have spot sizes of, for example, 40 μm (or approximately), 50 μm (or approximately), or 85 μm (or approximately).

[0123] In one embodiment, the first period described above is shorter than the second period described above. For example, the first period may be in the range of 4 μs (or around that) to 8 μs (or around that), and the second period may be in the range of 8 μs (or around that) to 12 μs (or around that). In other embodiments, the first period may be equal to the second period, or it may be longer.

[0124] In one embodiment, the pulse duration of each pulse in the first pulse slice 3002 is equal to (or at least substantially equal to) the pulse duration of each pulse in the second pulse slice 3004. For example, the first pulse slice 3002 and the second pulse slice 3004 may each have a pulse duration of 1 μs (or around that). However, in other embodiments, the pulse duration of any of the pulses in the first pulse slice 3002 is longer or shorter than the pulse duration of any of the pulses in the second pulse slice 3004.

[0125] Figure 30 illustrates a pulse slicing technique that includes two pulse slice sets with different optical powers (i.e., a first pulse slice 3002 and a second pulse slice 3004), but it can be seen that the pulse slicing technique described above may be modified to include one or more additional pulse slice sets. Each of the additional pulse slice sets may include one or more pulse slices 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 preceding pulse slice set.

[0126] b. Facilitating the removal of relatively thick layers When forming vias in a workpiece 102 by scanning a laser energy beam (for example, along the scan patterns described above with respect to Figures 8 to 29 or other scan patterns), if the thickness of the first conductive structure 502 is relatively thin, it has been found that if the process spot irradiated by the laser energy beam is scanned along the scan patterns described above with respect to Figures 8 to 22 and Figure 24(a), the via openings (formed in the first conductive material of the workpiece 102) may have relatively low roundness. For convenience of explanation, the first conductive structure 502 can be considered "relatively thin" if it has a thickness of less than 5 μm (or around that). For example, a relatively thin first conductive structure 502 may have a thickness of 4.5 μm, 4 μm, 3 μm, 2.5 μm, 2 μm, 1.5 μm, 1 μm, or any value in between these values.

[0127] In fact, as described above, when a process spot irradiated by a laser energy beam having a set of characteristics is scanned along the scan pattern described above with respect to Figures 8 to 22 and 24(a) in order to remove a first conductive 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 a value between any of these values), the laser energy -ga The process spots may be uniformly (or at least somewhat uniformly) distributed across the region of the workpiece 102 where the vias are formed before the first conductive structure 502 is ablated. However, simulations performed by the applicant showed that when the same laser energy beam (characterized, for example, by the same set of properties) is scanned along the same scan pattern, if the first conductive structure 502 is relatively thin (as described above), the first conductive structure 502 will be ablated before the process spots are scanned along the entire length of the scan pattern. The results of this simulation have been confirmed by experiments performed by the applicant.

[0128] To improve the roundness of via openings formed in a relatively thin first conductive structure 502 (for example, during the process of forming vias (e.g., non-through vias 600 or through vias 700)), the scan pattern can be modified as described above with respect to Figures 8 to 22 and 24(a) to include one or more spot locations at or near the geometric centroid of the scan pattern (e.g., at or near coordinates 0,0 shown in any of Figures 8 to 22 and 24(a)). Here, the spot locations of the scan pattern actually shown in Figures 8 to 22 and 24(a) are referred to herein as “heated spot locations”, and one or more spot locations at or near the geometric centroid of the scan pattern are referred to herein as “removed spot locations”. The heated spot locations are specified by a laser energy beam by any preferred method as described above with respect to Figures 8 to 22 and 24(a), and then one or more removed spot locations are specified. However, when specifying the heating spot locations, the laser energy beam irradiated onto the workpiece 102 is characterized by a set of characteristics (e.g., peak power, pulse duration, pulse energy, etc.) that are sufficient to uniformly (or at least somewhat uniformly) heat the region of the first conductive structure 502 where vias are formed to or near the processing threshold temperature of the first conductive structure 502, but are insufficient to ablate the heated first conductive structure 502. Subsequently, one or more removal spot locations of the modified scan pattern are specified using a laser energy beam characterized by a set of characteristics (e.g., peak power, pulse duration, pulse energy, etc.) that are sufficient to ablate the heated region of the first conductive structure 502 (e.g., by indirect ablation, direct ablation, or a combination thereof).

[0129] In one embodiment, the peak power of one or more pulses of the laser energy beam used to specify the removal spot location is higher than the peak power of one or more pulses of the laser energy beam used to specify each of the heating spot locations. Regardless of whether each laser pulse specifies a removal spot location or a heating spot location, it will be understood that the peak power of each laser pulse may depend on the thickness of the first conductive structure 502 (i.e., as the thickness of the first conductive structure 502 decreases, the required peak power decreases). For example, for a first conductive structure 502 having a thickness of 2 μm, any removal spot location may be specified by a laser pulse having a peak power in the range of 1 kW (or around) to 2 kW (or around), and a heating spot location may be specified by a laser pulse having a peak power in the range of 250 W (or around) to 350 W (or around). If the first conductive structure 502 has a thickness of 1.5 μm, for example, an arbitrary removal spot position can be specified by a laser pulse having a peak power in the range of 300 W (or around that) to 500 W (or around that), and a heating spot position can be specified by a laser pulse having a peak power in the range of 150 W (or around that) to 250 W (or around that).

[0130] In other embodiments, the pulse duration of one or more pulses of the laser energy beam used to designate the removal spot location is longer than or equal to the pulse duration of each pulse used to designate the heating spot location. However, generally, the total time for which heating spot locations are designated will be longer than the total time for which one or more removal spot locations are designated. For example, the total time for which one or more removal spot locations are designated may range from 10% (or around) to 25% (or around) of the total time for which heating spot locations are designated. It will be understood that one or more removal spot locations may be designated for a longer period than 25% (or around) of the total time for which heating spot locations are designated (e.g., 30% to 60% of the total time for which heating spot locations are designated). In this case, the energy of the laser pulses irradiated during the removal step will also be used to remove a portion of the dielectric structure 500.

[0131] In one embodiment, by operating the first positioner 106 as described above, characteristics such as the peak power and pulse duration of the laser energy beam irradiated onto the workpiece 102 during the heating and removal of the first conductive structure 502 can be suitably modified.

[0132] v. Further discussion on feature shape distortion As described above, the scan patterns shown in Figures 8 to 22 and Figure 24(a) can be characterized as having radii in the range of 10 μm (or around that) to 60 μm (or around that). It can be understood that the radius of the scan pattern can be increased if the characteristics of the scan pattern (e.g., the number of spot positions in the scan pattern, the arrangement of spot positions in the scan pattern, the order or sequence in which the spot positions in the scan pattern are specified, the distance between consecutively specified spot positions, or any combination thereof) and the characteristics of the laser energy beam irradiated onto the workpiece 102 (e.g., average power, pulse duration, pulse repetition rate, pulse energy, peak power, spot size, or any combination thereof) are maintained or modified to be sufficient to form vias having desired characteristics such as the shape of via openings (e.g., roundness) formed on the first conductor 502.

[0133] For example, when modifying a continuously specified type 2 scan pattern, as shown in Figure 17 or Figure 19, to have a radius greater than approximately 60 μm (e.g., 70 μm or more), the modified continuously specified type 2 scan pattern may include more spot positions (e.g., to maintain the desired pitch between adjacent spot positions, between continuously specified spot positions, etc.). If necessary, one or more properties of the laser energy beam irradiated onto the workpiece 102 (e.g., average power, pulse duration, pulse repetition rate, pulse energy, peak power, spot size, etc.) can also be modified to form vias with desired properties, such as the shape of the via openings formed in the first conductor 502 (e.g., roundness). However, when modifying a continuously specified type 2 scan pattern, it may be necessary to simply avoid including more spot positions (e.g., to maintain the desired pitch between adjacent spot positions, between continuously specified spot positions, etc.), because a portion of the first conductor between the first and last spot positions in the scan pattern may still remain, potentially generating via openings with low roundness.

[0134] An example of a via opening with low roundness formed in the first conductor (e.g., copper layer) of workpiece 102 is shown in the micrograph of Figure 46. The via opening shown in Figure 46 was formed by scanning process spots across workpiece 102 along a continuously specified second-type scan pattern similar to the scan patterns shown in Figures 17 and 19 (for example, irradiated with a laser energy beam having properties within the range described above with respect to the scan patterns shown in Figures 17 and 19). However, the radius of the scan pattern was increased to 70 μm in particular. In the micrograph shown in Figure 46, the "tabs" located within the dashed area are the cause of the low roundness of the via opening. Although we do not wish to be constrained to a specific ion, it is thought that by the time the last spot position was specified, the temperature of the portion of the first conductor 502 located at or near the first spot position of the scan pattern was below the processing threshold temperature of the first conductor 502. Therefore, when the final spot position was specified, there was not enough thermal energy in the first conductor 502 to promote its removal at or near the first spot position.

[0135] In one embodiment, the roundness of the via opening of the first conductor 502 can be improved by specifying one or more of the first spot locations specified in the scan pattern after all other spot locations have been specified. For example, referring to the sequentially specified second type scan pattern shown in Figure 47, after the 1st to 24th spot locations 1 to 24 have been specified, the location in the scan pattern specified by the 1st spot location 1 is specified again (therefore, the points indicated by "1,25" represent the locations of the 1st and 25th spot locations in the scan pattern). If necessary, other previously specified spot locations can be specified after the 25th spot location. For example, referring again to Figure 47, spot location 2 is specified after spot location 25 has been specified (therefore, the points indicated by "2,26" represent the locations of the 2nd and 26th spot locations which overlap). Spot location 3 may be specified after spot location 26 has been specified (therefore, the points indicated by "3,27" represent the locations of the 3rd and 27th spot locations which overlap). When used herein, overlapping spot locations (for example, as described above) are referred to herein as "continuously designated Type 2 scan pattern overlapping spot locations." With respect to any consecutively designated Type 2 scan pattern overlapping spot locations, the last designated spot location is referred to as the "final designated overlapping spot location." For example, in the spot location indicated by "1,25," spot location 25 can be called the "final designated overlapping spot location," and in the spot location indicated by "2,26," spot location 26 can be called the "final designated overlapping spot location."

[0136] In the sense of maintaining the desired roundness of the via opening in the first conductor, a suitable continuously specified Type 2 scan pattern provides the first spot position of the first as a continuously specified Type 2 scan pattern overlapping spot position. One or more continuously specified spot positions following the first spot position may also be provided as continuously specified Type 2 scan pattern overlapping spot positions. Thus, the number of continuously specified Type 2 scan pattern overlapping spot positions that may be included in a Type 2 scan pattern may be equal to 1, 2, 3, 4, 5, and so on. Instead of specifying the number of continuously specified Type 2 scan pattern overlapping spot positions included in a Type 2 scan pattern, the number of continuously specified Type 2 scan pattern overlapping spot positions that may be included in a Type 2 scan pattern can be expressed as a percentage of the total number of spot positions in the Type 2 scan pattern. In this case, the continuously specified Type 2 scan pattern overlapping spot positions may account for 12% (or around that) of the total number of spot positions in the Type 2 scan pattern. For example, this percentage could be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, or any value in between. However, ultimately, the number of consecutively designated Type 2 scan pattern overlapping spot locations included within the Type 2 scan pattern may depend on one or more factors, such as any of the scan pattern characteristics described above, any of the characteristics of the laser energy beam irradiated onto the workpiece 102 (e.g., wavelength, average power, pulse duration, pulse repetition rate, pulse energy, peak power, light intensity, fluence, spot size, etc.), or any combination thereof, such as the characteristics of the workpiece 102 (e.g., thickness of the first conductor, etc.). With respect to Figure 47, by providing the continuously specified second type scan pattern as described above, the region of the first conductor at or near the first spot location (i.e., spot location 1) accumulates enough thermal energy to facilitate its removal, thereby generating a via opening of high circularity in the first conductor (as shown, for example, in Figure 48).It should be noted that if there are too many spot locations provided as overlapping spot locations in a continuously specified type 2 scan pattern, the first conductor may be overworked, and low-roundness via openings, as shown in Figure 49, may be generated in the first conductor again.

[0137] Up to this point, the distances between each pair of sequentially designated spot positions in a sequentially designated Type 2 scan pattern, such as those described with respect to Figures 17 and 19, are the same (or at least approximately the same). For example, the distance between spot positions 3 and 4 in either Figure 17 or Figure 19 is the same (or approximately the same) as the distance between spot position 1 and the last spot position (i.e., spot position 12 in Figure 17 and spot position 18 in Figure 19). In the sense of maintaining the desired roundness of the via opening in the first conductor, a suitable sequentially designated Type 2 scan pattern can be constructed such that the distance between pairs of sequentially designated spot positions, including the last designated spot position, is shorter than the distance between the remaining pairs of sequentially designated spot positions. For example, referring to Figure 50, the distance between spot positions 24 and 25 may be shorter than the distance between spot positions 1 and 2, spot positions 10 and 11, etc. Generally, the distance between the last two designated spot locations (e.g., between spot locations 24 and 25) can be in the range of 30% (or around) to 99% (or around) of the distance between other pairs of continuously designated spot locations. By providing a continuously designated second-type scan pattern as described above with respect to Figure 50, the region of the first conductor at or near the first spot location (i.e., spot location 1) can accumulate enough thermal energy to facilitate its removal, thereby generating a via opening of high circularity in the first conductor.

[0138] In other embodiments, a continuously specified Type II scan pattern can be modified to include one or more spot positions between at least one pair of continuously specified spot positions. Thus, continuously specified spot positions in one portion of the Type II scan pattern may be adjacent to each other (for example, as in a continuously specified Type II scan pattern), while continuously specified spot positions in other portions of the Type II scan pattern may not be adjacent to each other (for example, as in a discontinuously specified Type II scan pattern). This type of Type II scan pattern is referred to herein as a "hybrid Type II scan pattern." An example of a hybrid Type II scan pattern is shown in Figure 51. Referring to Figure 51, the hybrid Type II scan pattern includes a spot position 25 located between spot positions 1 and 2 (specified consecutively after spot position 24). )ofIt may include. Although Figure 51 illustrates that there is only one spot position (i.e., spot position 25) between spot positions 1 and 2, it will be understood that multiple spot positions may be located between spot positions 1 and 2 or between any other pair of consecutively designated spot positions. If necessary, the hybrid type 2 scan pattern may further include one or more additional spot positions, such as spot position 26 (specified consecutively after spot position 25), located between one or more additional pairs of consecutively designated spot positions, such as between spot positions 2 and 3. By providing the hybrid type 2 scan pattern as described above with respect to Figure 51, the first spot position (i.e., spot position 1) or the region of the first conductor in its vicinity accumulates enough thermal energy to facilitate its removal, thereby generating a highly circular via opening in the first conductor (e.g., as shown in Figure 48). However, ultimately, the number of spot positions added between a pair of consecutively designated spot positions, or the number of pairs of consecutively designated spot positions between which spot positions are located, may depend on one or more factors, such as any of the scan pattern characteristics described above, any of the characteristics of the laser energy beam irradiated onto the workpiece 102 (e.g., wavelength, average power, pulse duration, pulse repetition rate, pulse energy, peak power, light intensity, fluence, spot size, etc.), the characteristics of the workpiece 102 (e.g., thickness of the first conductor, etc.), or any combination thereof. It should be noted that if there are too many spot positions provided between a pair of consecutively designated spot positions, or if there are too many pairs of consecutively designated spot positions between which one or more spot positions are located, the first conductor may be overworked, resulting in the creation of via openings with low roundness (e.g., as shown in Figure 49) in the first conductor.

[0139] While second-type scan patterns useful for generating vias with relatively large radii and highly circular openings have been described separately with respect to Figures 47, 50, and 51, it should be recognized that the characteristics specific to each type of second-type scan pattern may be combined in any preferred or desired manner.

[0140] B. Feature formation by punching process To form features such as vias (e.g., a non-penetrating via 600 as illustrated in Figure 6 or a penetrating via 700 as illustrated in Figure 7) on the workpiece 102 (for example, configured as described above), the first positioner 106 may be provided as a multi-axis AOD system (e.g., AOD system 200) and operated to repeatedly generate process spots at the same (or substantially the same) locations on the workpiece 102. As used herein, the term “punching process” means irradiating the workpiece 102 with a set of laser pulses at the same (or substantially the same) spot locations to form features (e.g., vias or other apertures). During the punching process (e.g., to form features such as vias or other apertures), the first positioner 106 may be operated to perform full pulse deflection, partial pulse deflection (i.e., pulse slicing as described above), or a combination of full and partial pulse deflection.

[0141] During a punching process (for example, to form a feature such as a via or other opening), the first positioner 106 can be operated to prevent the material of the workpiece 102 (e.g., dielectric structure 500) from being excessively heated (as a result of irradiation with laser pulses), or to prevent the workpiece 102 (or one or more constituent structures of the workpiece 102) from being undesirably warped, delaminated, or modified. As will be described in more detail below, during the punching process, the first positioner 106 can be operated to ensure that the laser pulses in at least one consecutive pair of laser pulses in the laser pulse set are irradiated intermittently (i.e., one laser pulse starts immediately after a delay following the previous laser pulse), or to modify the optical power of one laser pulse in the laser pulse set relative to other laser pulses, or to modify the pulse duration of one laser pulse in the laser pulse set relative to other laser pulses, or to combine these as desired.

[0142] i. Examples of embodiments relating to pulse slicing Referring to Figure 32, the first positioner 106 can be operated to temporally divide a mother laser pulse (e.g., mother laser pulse 3201) into multiple pulse slices during the punching process. Thus, the first positioner 106 can be operated to deflect pulse slices by the same angle (or at least substantially the same angle) within the primary angle range 116 within at least one continuously divided pair of pulse slices. It can be seen that multiple pulse slices themselves can be grouped into multiple pulse slice sets (e.g., pulse slice sets 3200a and 3200b, collectively referred to as "pulse slice set 3200"). In this case, the first positioner 106 can be operated to deflect pulse slices in a common pulse slice set 3200 by the same angle (or at least substantially the same angle) within the primary angle range 116, and pulse slices in different pulse slice sets 3200 by different angles (or at least substantially different angles) within the primary angle range 116. For example, the first positioner 106 can be operated to deflect the pulse slice in pulse slice set 3200a by a first angle within the primary angle range 116 shown in Figure 1 (or by an angle within the first primary angle range 116a shown in Figure 31), and the pulse slice in pulse slice set 3200b by a second angle within the primary angle range 116 shown in Figure 1 (or by an angle within the second primary angle range 116b shown in Figure 31). However, the pulse slices in pulse slice sets 3200a and 3200b can be considered as a common pulse slice set, and it will be understood that all pulse slices in pulse slice sets 3200a and 3200b can be deflected to the same (or at least substantially the same) angle within the primary angle range 116. As illustrated, at a given time, the power of the pulse slice is lower than the power of the mother laser pulse 3201 from which the pulse slice is time-divided.The power difference between the mother laser pulse 3201 and the pulse slice may be the result of the diffraction efficiency of one or more AODs in the first positioner 106 when the first positioner 106 is operated to generate the pulse slice, the intrinsic optical loss associated with the use of AODs within the first positioner 106, or any combination thereof.

[0143] In the illustrated embodiment, pulse slice set 3200a includes a primary pulse slice 3202a and a plurality of secondary pulse slices 3204a. Similarly, in the illustrated embodiment, pulse slice set 3200b includes a primary pulse slice 3202b and a plurality of secondary pulse slices 3204b. As used herein, primary pulse slices 3202a and 3202b are collectively referred to as "primary pulse slice 3202," and secondary pulse slices 3204a and 3204b are collectively referred to as "secondary pulse slice 3204." In the illustrated embodiment, the pulse duration and pulse energy of the primary pulse slice 3202 are greater than the pulse duration and pulse energy of each secondary pulse slice 3204. However, pulse slice set 3200a may include a plurality of primary pulse slices 3202a and one or more secondary pulse slices 3204a. Similarly, in other embodiments, the pulse slice set 3200b may include a plurality of primary pulse slices 3202b and one or more secondary pulse slices 3204b.

[0144] In one embodiment, a primary pulse slice 3202 is used to ablate the first conductive structure 502 of the workpiece 102 (via direct ablation, indirect ablation, or a combination thereof). In this case, the pulse duration and pulse energy of a single primary pulse slice 3202 are sufficient to ablate the first conductive structure 502 of the workpiece 102. In another case, the pulse duration and pulse energy of each of the multiple primary pulse slices 3202 in a common pulse slice set 3200 are sufficient to ablate the first conductive structure 502 by the multiple primary pulse slices 3202. However, in other embodiments, if the first conductive structure 502 is not present at a desired spot location on the workpiece 102, one or more primary pulse slices 3202 can be used to ablate the dielectric structure 500 of the workpiece 102 (via direct ablation, indirect ablation, or a combination thereof). It should be noted that the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of at least one primary pulse slice 3202 in the pulse slice set may be greater than, less than, or the same as, the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of other primary pulse slices 3202 in the same pulse slice set.

[0145] In one embodiment, each secondary pulse slice 3204 is generally used to remove the dielectric structure 500 of the workpiece 102 without significantly altering the second conductive structure 504 (for example, to form non-penetrating vias such as non-penetrating vias 600). In this case, the pulse duration and pulse energy of each secondary pulse slice 3204 are sufficient to remove the first conductive structure 502 of the workpiece 102 (for example, via ablation, evaporation, melting, or any combination thereof), and at least the pulse duration and / or pulse energy of the last secondary pulse slice 3204 are sufficient to remove the dielectric structure 500 of the workpiece 102 without significantly altering the second conductive structure 504. Therefore, the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of at least one secondary pulse slice 3204 in a single pulse slice set may be greater than, less than, or the same as, the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of other secondary pulse slices 3204 in the same pulse slice set.

[0146] In other embodiments, one or more secondary pulse slices 3204 can be used to ablate the second conductive structure 504 of the workpiece 102 (via direct ablation, indirect ablation, or a combination thereof). In this case, one or more secondary pulse slices 3204 can be irradiated onto the workpiece 102 after the second conductive structure 504 has been ablated to remove the dielectric structure 508 (for example, via ablation, evaporation, melting, or any combination thereof) (for example, to form through vias such as through vias 700). Therefore, the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of at least one secondary pulse slice 3204 in a given pulse slice set may be greater than, less than, or the same as, the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of other secondary pulse slices 3204 in the same pulse slice set.

[0147] However, in yet another embodiment, pulse slice sets 3200a and 3200b can be used to form through vias (e.g., through via 700). In this case, pulse slice set 3200a can be used to sequentially remove material from the first conductive structure 502 and dielectric structure 500, and pulse slice set 3200b can be used to sequentially remove material from the second conductive structure 504 and dielectric structure 508.

[0148] In further embodiments, if the dielectric structure 500 is made of a heterogeneous material (for example, FR4, known as a glass fiber reinforced epoxy laminate containing a fibrous glass fabric within an epoxy resin matrix), and if a portion of the dielectric structure 500 at a desired spot location on the workpiece 102 contains glass material, the pulse duration and pulse energy of at least one secondary pulse slice 3204 intended to remove glass material can be modified relative to the pulse duration and pulse energy of at least one other secondary pulse slice 3204 intended solely to remove epoxy resin, so that the glass material can be efficiently removed at the desired spot location (for example, via ablation, evaporation, melting, or any combination thereof). Therefore, the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of at least one secondary pulse slice 3204 in a given pulse slice set may be greater than, less than, or the same as, the pulse duration, pulse energy, peak optical power, and temporal optical power profile (e.g., a rectangular shape as shown by the various pulse slices in Figure 32) of other secondary pulse slices 3204 in the same pulse slice set.

[0149] If a series of laser pulses are intermittently irradiated during the punching process, the first positioner 106 can be operated to ensure that the 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 cool the material at or near the spot location to some extent (for example, to a temperature below the material’s damage threshold temperature) before the next laser pulse is irradiated. For example, referring to Figure 32, the first positioner 106 can be operated to ensure that the gap time Tg1a between the start of the first secondary pulse slice 3204a of pulse slice set 3200a and the end of the primary pulse slice 3202a of pulse slice set 3200a is sufficient to cool the material of the dielectric structure 500 at or near the spot location to some extent before the first secondary pulse slice 3204a is irradiated, thereby avoiding undesirable modification of the material of the dielectric structure 500 at or near the spot location. The gap time Tg1b between the start of the first secondary pulse slice 3204b of pulse slice set 3200b and the end of the primary pulse slice 3202b of pulse slice set 3200b may be longer than, shorter than, or equal to the gap time Tg1a.

[0150] As shown in Figure 32, the first positioner 106 can be operated to ensure that the gap time Tg2 between the continuously irradiated secondary pulse slices 3204a of the pulse slice set 3200a is sufficient to maintain the material of the dielectric structure 500 at or near the spot location at a temperature sufficient to enable suitable processing of the dielectric structure 500 without causing undesirable damage to the surrounding material. The gap time between the continuously irradiated secondary pulse slices 3204b of the pulse slice set 3200b may be longer than, shorter than, or equal to the gap time Tg2.

[0151] a. Sequential and interleaved deflection of laser pulse sets Referring to Figure 32, the first positioner 106 can be operated to temporally divide the mother laser pulse 3201 into multiple pulse slice sets 3200 during the punching process. The pulse slices in laser pulse slice set 3200a are all deflected to the same (or at least substantially the same) angle within the primary angle range 116 before the pulse slices in laser pulse slice set 3200b are deflected to different angles. Thus, the first positioner 106 is operated to deflect the laser pulse slice sets 3200a and 3200b using a sequential deflection method. In other embodiments, the first positioner 106 can be operated to deflect the laser pulse slice sets 3200a and 3200b using an interleaved deflection method. In the interleaved deflection method, during the punching process, the first positioner 106 is operated to temporally divide the mother laser pulse 3201 into multiple pulse slice sets 3200, so that one or more pulse slices in the laser pulse slice sets 3200a and 3200b are alternately deflected between different angles within the primary angle range 116.

[0152] For example, referring to Figure 33, the primary pulse slice 3202a is deflected by a first angle within the primary angle range 116 shown in Figure 1 (or by a first angle within the first primary angle range 116a shown in Figure 31), then the primary pulse slice 3202b is deflected by a second angle within the primary angle range 116 shown in Figure 1 (or by a first angle within the second primary angle range 116b shown in Figure 31), and then the secondary pulse slice The first positioner 106 can be operated by an interleaved deflection method in which 3204a is deflected by a first angle within the primary angle range 116 shown in Figure 1 (or by a first angle within the first primary angle range 116a shown in Figure 31), and then the secondary pulse slice 3204b is deflected by a second angle within the primary angle range 116 shown in Figure 1 (or by a first angle within the second primary angle range 116b shown in Figure 31).

[0153] In other examples, referring to Figure 34, the first positioner 106 can be operated by an interleaved deflection method, similar to the method described with respect to Figure 33, in which the secondary pulse slices 3204a and 3204b are alternately deflected between a first angle and a second angle within the primary angle range 116 shown in Figure 1 (or between the first angle of the first primary angle range 116a and the first angle of the second primary angle range 116b shown in Figure 31).

[0154] Considering the aforementioned gap time between pulse slices in a pulse slice set, the total time required to form a feature (e.g., a via or other opening) by the punching process can vary, regardless of whether the first positioner 106 is operated by a sequential deflection method or an interleaved deflection method. For example, if the total time required to form a feature using pulse slice set 3200a is Ta, and the total time required to form a feature using pulse slice set 3200b is Tb (Tb may be longer than, shorter than, or equal to Ta), then the total time required to form two features using pulse slice sets 3200a and 3200b is Tt1 when the first positioner 106 is operated by a sequential deflection method (see, for example, Figure 32). However, using the interleaved deflection method shown in Figure 33, the total time required to form the same two features using pulse slice sets 3200a and 3200b is Tt2, which is shorter than Tt1. In Figure 33, the gap time Tg1b' is shown as being longer than the gap time Tg1b. However, it should be noted that the gap time can be made equal to the gap time Tg1b by adjusting the pulse duration and / or power of the secondary pulse slice 3204a, by adjusting the gap time between the primary pulse slice 3202b and the first secondary pulse slice 3204a, by adjusting the gap time Tg2 between the secondary pulse slices 3204a, by adjusting the gap time between the last secondary pulse slice 3204a and the first secondary pulse slice 3204b, or by any combination of these.

[0155] Similarly, using the interleaved deflection method shown in Figure 34, the total time required to form two features using pulse slice sets 3200a and 3200b is Tt2. In Figure 34, the gap time Tg1b'' is shown as being shorter than the gap time Tg1b. However, it should be noted that the gap time Tg2 between the secondary pulse slices 3204a can be adjusted by, for example, adjusting the pulse duration and / or power of the first secondary pulse slice 3204a, adjusting the gap time between the primary pulse slice 3202b and the first secondary pulse slice 3204a, or by any combination of these, so that it is equal to the gap time Tg1b.

[0156] While embodiments of the punching process have been described herein, it will be understood that these embodiments can also be applied to forming features using scan patterns (for example, by scanning process spots along the scan patterns described herein with respect to Figures 8 to 29, 47, 50, or 51, or by other means).

[0157] b. Additional examples regarding laser pulse sets In the embodiments shown in Figures 32 to 34, each pulse slice in the pulse slice set has a rectangular temporal power profile, and the peak optical power of any pulse slice in the pulse slice set is the same as the peak optical power of all other pulse slices in that pulse slice set. In other embodiments, one or more pulse slices in the pulse slice set may have temporal power profiles of other shapes, and the peak optical power of any pulse slice in the pulse slice set may be different from, or a combination of, the peak optical power of, other pulse slices in the pulse slice set.

[0158] Furthermore, in the examples shown in Figures 32 to 34, the characteristics of pulse slices within one pulse slice set (i.e., pulse energy, pulse duration, temporal power profile, number of pulse slices, gap time, etc.) are identical (or substantially identical) to the characteristics of corresponding pulse slices within other pulse slice sets. Therefore, pulse slice sets temporally divided from a common mother pulse can be considered identical. In other embodiments, at least one characteristic of at least one pulse slice within a single pulse slice (e.g., pulse energy, pulse duration, temporal power profile, number of pulse slices, gap time, etc.) differs from the characteristics of at least one corresponding pulse slice in other pulse slice sets. Therefore, pulse slice sets temporally divided from a common mother pulse can be considered different.

[0159] Figures 35 to 45 show yet another embodiment of exemplary pulse slice sets that may be generated by operating the first positioner 106 during a punching process or a process spot scanning process to form features (e.g., vias such as non-through vias and through vias or other openings) (e.g., by scanning the process spot along one of the scan patterns described herein or by other means).

[0160] Referring to Figure 42, the temporal power profile of the secondary pulse slice 3204 is continuously modulated (for example, as shown by a downward-sloping line). In this case, the secondary pulse slice 3204 shown in Figure 42 may be deflected by a single angle within the primary angular range 116, or by multiple angles within a common primary angular range 116 (over time). In Figure 42, reference numeral 3204' indicates that the temporal power profile is continuously modulated (for example, so that it increases over time rather than decreases). ru2This represents another secondary pulse slice relative to the first pulse slice 3204. Figures 44 and 45 show another embodiment in which the secondary pulse slice 3204 may have different temporal power profiles that are continuously modulated.

[0161] Referring to Figure 43, the temporal power profile of the secondary pulse slice 3204 is modulated in steps. In this case, the secondary pulse slice 3204 shown in Figure 43 may be deflected by a single angle within the primary angular range 116, or by multiple angles within a common primary angular range 116 (over time). Similar to the example shown in Figure 42, the secondary pulse slice 3204 shown in Figure 43 can be inverted (for example, to have a relatively low optical power before being modulated to have a relatively high optical power).

[0162] IX. Conclusion The foregoing describes embodiments and examples of the present invention and should not be construed as limiting thereto. While several specific embodiments and examples have been described with reference to the drawings, those skilled in the art will readily recognize that many improvements are possible to the disclosed embodiments and examples and other embodiments without departing largely from the novel teachings and advantages of the present invention. Therefore, all such improvements are intended to fall within the scope of the present invention as defined in the claims. For example, those skilled in the art will understand that the subject matter of any sentence or paragraph, example or embodiment can be combined with the subject matter of some or all of the other sentences or paragraphs, examples or embodiments, unless such combinations are mutually exclusive. Therefore, the scope of the present invention should be determined by the following claims and their equivalents.

Claims

1. A positioner capable of deflecting a laser energy beam, A first scan head and a second scan head, each having a scan lens, Controller and Equipped with, The aforementioned controller, The positioner is controlled to temporally divide one laser pulse of the laser energy beam incident on the positioner into a plurality of pulse slices, including a first pulse slice set and a second pulse slice set. Each of the first pulse slice set and the second pulse slice set includes one or more primary pulse slices used for a first machining operation on the workpiece, and one or more secondary pulse slices used for a second machining operation on the workpiece that is different from the first machining operation. The positioner is controlled to deflect the first pulse slice set toward the first scan head. The positioner is controlled to deflect the second pulse slice set toward the second scan head. The positioner is controlled to alternately deflect between the pulse slices in the first pulse slice set and the pulse slices in the second pulse slice set. It is configured in such a way. Laser processing equipment.

2. The laser processing apparatus according to claim 1, wherein in at least one of the first pulse slice set and the second pulse slice set, the primary pulse slice has a higher optical power than the one or more secondary pulse slices.

3. The laser processing apparatus according to claim 1, wherein in at least one of the first pulse slice set and the second pulse slice set, the primary pulse slice has a lower optical power than the one or more secondary pulse slices.

4. The aforementioned controller, The positioner is controlled to maintain a first gap time between the primary pulse slice and the first secondary pulse slice. The positioner is controlled to maintain a second gap time between subsequent secondary pulse slices. It is further configured in this way, The second gap time is different from the first gap time. The laser processing apparatus according to claim 1.

5. The laser processing apparatus according to claim 4, wherein the second gap time is shorter than the first gap time.

6. The laser processing apparatus according to claim 1, wherein at least two pulse slices in at least one of the first pulse slice set and the second pulse slice set have different temporal optical power profiles.

7. The laser processing apparatus according to claim 1, wherein at least two pulse slices in at least one of the first pulse slice set and the second pulse slice set have different pulse widths.

8. The laser processing apparatus according to claim 1, wherein at least one laser pulse in the first pulse slice set has substantially the same characteristics as the corresponding laser pulse in the second pulse slice set.

9. The laser processing apparatus according to claim 1, wherein at least one laser pulse in the first pulse slice set does not have substantially the same characteristics as the corresponding laser pulse in the second pulse slice set.

10. The laser processing apparatus according to claim 1, wherein the controller is further configured to control the positioner to interleave the deflection of at least one pulse slice from the first pulse slice set and the second pulse slice set.

11. The laser processing apparatus according to claim 1, wherein the positioner includes an acousto-optic deflector.

12. A controller for a laser processing device, Processor and When executed by the aforementioned processor, the controller The positioner is controlled to temporally divide one laser pulse of the laser energy beam incident on the positioner into a plurality of pulse slices, including a first pulse slice set and a second pulse slice set. Each of the first pulse slice set and the second pulse slice set includes one or more primary pulse slices used for a first machining operation on the workpiece, and one or more secondary pulse slices used for a second machining operation on the workpiece that is different from the first machining operation. The positioner is controlled to deflect the first pulse slice set toward the first scan head. The positioner is controlled to deflect the second pulse slice set toward the second scan head. The positioner is controlled to alternately deflect between the pulse slices in the first pulse slice set and the pulse slices in the second pulse slice set. The memory that stores the instructions and A controller equipped with the following features.

13. When the aforementioned instruction is executed by the processor, it further instructs the controller, The positioner is controlled to maintain a first gap time between the first pulse slice and the first secondary pulse slice. The positioner is controlled to maintain a second gap time between subsequent secondary pulse slices. The second gap time is different from the first gap time. The controller according to claim 12.

14. The controller according to claim 12, wherein, when the instruction is executed by the processor, the controller further controls the positioner to generate at least two pulse slices from at least one of the first pulse slice set and the second pulse slice set, such that they have different temporal optical power profiles.

15. The controller according to claim 12, wherein, when the instruction is executed by the processor, the controller further controls the positioner to generate at least two pulse slices from at least one of the first pulse slice set and the second pulse slice set, having different pulse widths.

16. The controller according to claim 12, wherein, when the instruction is executed by the processor, the controller further controls the positioner to interleave the deflection of at least one pulse slice from the first pulse slice set and the second pulse slice set.

17. When executed by the processor of the controller for the laser processing device, the controller The positioner is controlled to temporally divide one laser pulse of the laser energy beam incident on the positioner into a plurality of pulse slices, including a first pulse slice set and a second pulse slice set. Each of the first pulse slice set and the second pulse slice set includes one or more primary pulse slices used for a first machining operation on the workpiece, and one or more secondary pulse slices used for a second machining operation on the workpiece that is different from the first machining operation. The positioner is controlled to deflect the first pulse slice set toward the first scan head. The positioner is controlled to deflect the second pulse slice set toward the second scan head. The positioner is controlled to alternately deflect between the pulse slices in the first pulse slice set and the pulse slices in the second pulse slice set. A non-transient, computer-readable storage medium that stores instructions for performing actions including the above.

18. The aforementioned operation is, The positioner is controlled to maintain a first gap time between the primary pulse slice and the first secondary pulse slice. The positioner is controlled to maintain a second gap time between subsequent secondary pulse slices. This further includes, The second gap time is different from the first gap time. The non-transient computer-readable storage medium according to claim 17.

19. The non-transient computer-readable storage medium according to claim 17, further comprising controlling the positioner to generate at least two pulse slices from at least one of the first pulse slice set and the second pulse slice set having different temporal optical power profiles.

20. The non-transient computer-readable storage medium according to claim 17, further comprising controlling the positioner to generate at least two pulse slices from at least one of the first pulse slice set and the second pulse slice set having different pulse widths.

21. The non-transient computer-readable storage medium according to claim 17, further comprising controlling the positioner to interleave the deflection of at least one pulse slice from the first pulse slice set and the second pulse slice set.

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