Laser processing device for facilitating map inspection of laser-processed workpieces and method for operating the same

Abstract

A laser processing device for forming features in a workpiece includes at least one sensor for generating process control data representing a) at least one characteristic of the device before, during, or after the workpiece is processed to form a set of features, b) at least one characteristic of the workpiece before, during, or after the workpiece is processed to form a set of features, and / or c) at least one characteristic of the surrounding environment where the device is located before, during, or after the workpiece is processed to form a set of features. A controller executes a candidate feature selection process or facilitates the execution of a candidate feature selection process, thereby processing the process control data to estimate whether any of the features formed in the workpiece are defective, and identifying the location of any feature presumed to be defective.

Description

Technology Field

[0001] The embodiments disclosed herein generally relate to laser processing apparatuses and methods for laser processing of workpieces. Background Technology

[0002] Laser processing can be performed on numerous different workpieces using various lasers capable of performing various processes. For example, laser micromachining processes have been developed to form features, such as through-vias or blind-via holes, on workpieces such as printed circuit boards (PCBs) or integrated circuit (IC) packages. The purpose of laser micromachining processes is to provide consistent feature quality across the entire workpiece. Some measurements defining feature quality include the location, size, and geometry of the feature. Other measurements may include sidewall angles, bottom texture, and the volume and texture of debris remaining on the feature after processing.

[0003] One issue associated with laser micromachining processes is that, due to workpiece non-uniformity, performing the processes with the same laser parameters at two different locations on the workpiece can result in differences in feature quality. Examples of workpiece variations that affect the results include differences in thickness, flatness, and surface preparation that causes the workpiece to reflect laser power to some extent. These variations are not uniform across the entire workpiece and can vary depending on the location of individual features. Furthermore, these variations can be repeated from workpiece to workpiece across a given number of workpieces due to normal variations in manufacturing tolerances.

[0004] Other phenomena affecting the ability of a laser micromachining system to form features of consistent quality include damage and / or aging of the laser source used to generate the beam of laser energy and the optical components used to direct the laser energy to the workpiece. When the laser source ages, its ability to output laser energy with consistent characteristics (e.g., average power) may degrade. Additionally, when optical components age, they become contaminated, in particular, by debris from the micromachining process itself and damage from the high-power laser energy transmitted through them. These and other forms of degradation can cause the laser spot projected onto the workpiece to change in terms of size, shape, intensity, or other characteristics, thereby altering the size, shape, depth, or other measurements of the feature being micromachined.

[0005] Some laser micromachining systems use real-time controls to alter the characteristics of the laser energy beam when a feature is machined, in an attempt to mitigate the effects of changes in laser sources or optical components due to aging or damage. In some systems, photodetectors are used to monitor the laser power as the workpiece is processed. The output from the photodetector is used to adjust the laser power incident on the workpiece in real time to compensate for some sources of laser power variability in the workpiece. This can ultimately be achieved by operating optical components, such as variable attenuators, to adjust the amount of laser energy delivered to the workpiece to a level suitable for forming each feature.

[0006] It is known to record information regarding the characteristics of the laser energy beam used to form each feature in a workpiece and to associate that information with an identifier that identifies the location of the feature in the workpiece (e.g., thereby generating "process data"). After the processing of the workpiece is completed, the generated process data can be analyzed to predict when the laser micromachining system may have trouble forming features of suitable quality. For example, if the recorded information indicates that the system may have required more laser power than was available, features formed using less laser power may not have had sufficient material removed.

[0007] In addition, it is known to inspect processed workpieces to evaluate the quality of the formed features. The results of the inspection can be compared with process data (if generated) to evaluate the performance of the characteristics of the laser energy beam used to form the features in the workpiece. When performed on workpieces such as PCBs, post-processing inspection is carried out manually (e.g., by a user inspecting the workpiece using a microscope) or automatically (e.g., by automated optical inspection, "AOI"). When inspection is performed manually, since the workpiece may often have hundreds or thousands of features formed thereon, the inspected features (i.e., via holes) constitute only a sample of the total number of features formed thereon. When inspection is performed by AOI, all features of one or more workpieces in a lot can be inspected immediately after the features are formed (i.e., when the features are through via holes) or immediately after post-processing steps are performed to clean the features (e.g., when the features are blind via holes, desmear, etching, and shadow processing steps are performed to remove debris within the holes).

[0008] Conventional post-processing inspection technologies can be problematic for numerous reasons. In the case of manual inspection, operators using microscopes or quality inspectors may suffer from fatigue, which can lead to missed defects during periods of reduced attention. When all features are inspected (e.g., using AOI technologies), unnecessary additional time is spent inspecting areas of the workpiece where defective features are less likely to be formed. If features are inspected randomly, there is a risk that some areas of the workpiece likely to contain defective features will not be inspected, resulting in missed quality issues that could lead to the workpiece being scrapped.

[0009] One embodiment of the present invention can be broadly characterized as a laser processing device for forming features on a workpiece. The device comprises: a laser source operating to generate a beam of laser energy; an array of scan lenses operating to focus a beam of laser energy so that a focused beam of laser energy is delivered to a workpiece; at least one beam positioner arranged between the laser source and the scan lenses—the at least one beam positioner operating to scan a focused beam of laser energy for a workpiece within a scanning range projected onto the workpiece by the scan lenses—; at least one stage operating to provide relative movement between at least one selected from a group consisting of scan lenses and cameras and the workpiece; and a camera having a field of view and operating to capture an image of an object within the field of view. and at least one sensor operating to generate process control data - the process control data represents at least one selected from a group consisting of: a) at least one characteristic of the device before, during, or after the workpiece is processed to form a set of features; b) at least one characteristic of the workpiece before, during, or after the workpiece is processed to form a set of features; and c) at least one characteristic of the surrounding environment where the device is located before, during, or after the workpiece is processed to form a set of features -; comprising at least one stage, a camera, and a controller communically coupled to one or more databases in which the process control data is stored in association with auxiliary information, the auxiliary information representing the location of each feature to be formed on the workpiece. The controller operates to execute a candidate feature selection process or to facilitate the execution of the candidate feature selection process, thereby: the process control data is processed to estimate whether any feature formed on the workpiece is defective; and the location of any feature presumed to be defective is identified. Brief explanation of the drawing

[0010] FIG. 1 schematically illustrates a laser processing device according to one embodiment of the present invention. FIG. 2 illustrates an exemplary process for collecting passive input classifications of candidate features according to one embodiment of the present invention. Specific details for implementing the invention

[0011] Exemplary embodiments are described herein with reference to the accompanying drawings. Unless otherwise explicitly stated, the dimensions, positions, and distances between components, features, elements, etc., in the drawings are not necessarily actual scales and are exaggerated for clarity. Throughout the drawings, similar numbers represent similar elements. Accordingly, identical or similar numbers may be described by reference to other drawings even if they are not mentioned or described in the corresponding drawings. Additionally, elements not indicated by reference numbers may also be described by reference to other drawings.

[0012] The terms used herein are intended merely to describe specific exemplary embodiments and are not intended to be limiting. Unless otherwise defined, all terms used herein (including technical or scientific terms) have the same meaning as generally understood by those skilled in the art. As used herein, the singular forms “one (a, an)” and “the” are intended to include plural forms unless the context otherwise clearly indicates. It should be recognized that, as used herein, the terms “include” and / or “include” specify the presence of the mentioned features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise specified, when referred to, ranges of values ​​include both upper and lower limits of the range, as well as any sub-ranges between them. Unless otherwise specified, terms such as "first," "second," etc., are used solely to distinguish one element from another. For example, one node may be named "first node" and similarly another node may be named "second node," and vice versa.

[0013] Unless otherwise specified, terms such as “about,” “approximately,” etc., mean that quantities, sizes, formulations, parameters, and other quantities and characteristics are not precise and do not need to be precise, but, if desired, are approximations of reflecting tolerances, conversion factors, rounding, measurement errors, etc., and other factors known to those skilled in the art, and / or may be greater or smaller than. Spatially relative terms such as “below,” “beneath,” “lower,” “above,” and “upper,” etc., may be used herein for ease of description regarding the relationship of one element or feature to another element or feature as illustrated in the drawings. It should be recognized that spatially relative terms are intended to include different orientations in addition to the orientations illustrated in the drawings. For example, if an object in the drawings is flipped, elements described as "below" or "bottom" of other elements or features will be oriented "above" of other elements or features. Thus, the exemplary term "below" may include both top and bottom orientations. Objects may be oriented differently (e.g., rotated 90 degrees or into other orientations), and spatially relative descriptors used herein may be interpreted accordingly.

[0014] The section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described unless otherwise expressly stated. It will be understood that many different forms, embodiments, and combinations are possible without departing from the spirit and teachings of this disclosure, and therefore this disclosure should not be construed as being limited to the exemplary embodiments described herein. Rather, these examples and embodiments are provided to make this disclosure thorough and complete and to convey the scope of this disclosure to those skilled in the art.

[0015] I. Overview

[0016] The embodiments described herein generally relate to methods and apparatus for laser processing (or more simply "processing") a workpiece. Generally, processing is achieved wholly or partially by irradiating a workpiece with laser radiation to 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, magnetic permeability, relative permittivity, texture, color, hardness, transmittance to electromagnetic radiation, etc., or any combination thereof) of one or more materials on which the workpiece is formed, such as heating, melting, vaporization, ablation, cracking, discoloration, polishing, roughening, carbonization, foaming, or any combination thereof. The materials to be processed may be located outside the workpiece before or during processing, or may be located entirely within the workpiece before or during processing (i.e., not outside the workpiece).

[0017] Specific examples of processes that can be performed by the device disclosed for laser processing include via drilling or other hole forming, cutting, perforating, welding, scribing, engraving, marking (e.g., surface marking, subsurface marking, etc.), laser-induced forward transfer, cleaning, bleaching, bright pixel repair (e.g., color filter arm treatment, modification of OLED material, etc.), decoating, surface texturing (e.g., roughening, smoothing, etc.), etc., or any combination thereof. Accordingly, one or more features that may be formed on or within a workpiece as a result of processing may include openings, slots, vias or other holes, grooves, trenches, scribe lines, kerfs, concave areas, conductive traces, ohmic contacts, resist patterns, human or machine-readable markings (e.g., consisting of one or more areas within or on the workpiece having one or more visually or texturally distinct characteristics), or any combination thereof. Features such as openings, slots, vias, holes, etc. may have any suitable or desirable shape when viewed in a plan view (e.g., circular, elliptical, square, rectangular, triangular, circular, etc., or any combination thereof). Additionally, features such as openings, slots, vias, holes, etc. may be fully extended through the workpiece (e.g., to form so-called "through vias," "through holes," etc.) or partially extended through the workpiece (e.g., to form so-called "blind vias," "blind holes," etc.).

[0018] Workpieces that can be processed may generally be characterized by being formed from one or more metals, polymers, ceramics, composites, or any combination thereof (e.g., as alloys, compounds, mixtures, solutions, composites, etc.). Accordingly, the materials that can be processed include one or more metals such as Al, Ag, Au, Cr, Cu, Fe, In, Mg, Mo, Ni, Pt, Sn, Ti, etc. or any combination thereof (e.g., as alloys, composites, etc.), conductive metal oxides (e.g., ITO, etc.), transparent conductive polymers, ceramics, waxes, resins, interlayer dielectric materials (e.g., silicon oxide, silicon nitride, silicon oxynitride, etc.; low-k dielectric materials such as methyl silsesquioxane (MSQ), hydrogen silsesquioxane (HSQ), fluorinated tetraethyl orthosilicate (FTEOS), etc. or any combination thereof), organic dielectric materials (e.g., SILK, benzocyclobutene, Nautilus (all manufactured by Dow), polyfluorotetraethylene (manufactured by DuPont), FLARE (manufactured by Allied Chemical), etc. or any combination thereof), semiconductor or optical device substrates. Materials (e.g., Al2O3, AlN, BeO, Cu, GaAS, GaN, Ge, InP, Si, SiO2, SiC, Si1-xGex(where 0.0001 <x <0.9999) etc. or any combination or alloy thereof), glass (e.g., fused quartz, soda-lime-silica glass, sodium borosilicate glass, lead oxide glass, aluminosilicate glass, germanium oxide glass, aluminate glass, phosphate glass, borate glass, chalcogenide glass, amorphous metal, etc. or any combination thereof), sapphire, polymer materials (e.g., polyamide, polyimide, polyester, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyphenylene sulfide, polyether sulfone, polyether imide, polyether ether ketone, liquid crystal polymer, acrylonitrile butadiene styrene, or any compound, composite or alloy thereof), leather, paper, build-up materials (e.g., AJINOMOTO Build-up also known as "ABF") It includes films, etc.), solder resists, etc., or any composites, laminates, or other combinations thereof.

[0019] Specific examples of workpieces that may be processed include panels of printed circuit boards (PCBs) (also referred to herein as “PCB panels”), PCBs, PCB laminates (e.g., FR4, High Tg Epoxy, BT, polyimide, etc., or any combination thereof), PCB laminate prepregs, substrate-type PCBs (SLPs), panels of flexible printed circuits (FPCs) (also referred to herein as “FPC panels”), FPCs, coverlay films, integrated circuits (ICs), IC substrates, IC packages (ICPs), light-emitting diodes (LEDs), LED packages, semiconductor wafers, electronic or optical device substrates, interposers, lead frames, lead frame blanks, display substrates (e.g., TFTs, color filters, organic LED (OLED) arrays, quantum dot LED arrays, etc., or any combination thereof formed thereon), lenses, mirrors, turbine blades, powders, Includes films, foils, plates, molds (e.g., wax molds, molds for injection molding processes, investment-casting processes, etc.), fabrics (woven fabrics, felts, etc.), surgical instruments, medical implants, consumer goods, shoes, bicycles, automobiles, automobile or aircraft parts (e.g., frames, body panels, etc.), home appliances (e.g., microwave ovens, ovens, refrigerators, etc.), and device housings (e.g., watches, computers, smartphones, tablet computers, wearable electronic devices, etc., or any combination thereof).

[0020] II. System Overview

[0021] FIG. 1 schematically illustrates a laser processing device according to one embodiment of the present invention.

[0022] Referring to the embodiment shown in FIG. 1, a laser processing device (100) (also referred to herein simply as "device") for processing a workpiece (102) may be characterized by comprising a laser source (104) that generates a beam of laser energy, one or more positioners (e.g., a first positioner (106), a second positioner (108), a third positioner (110), or any combination thereof) and a scan lens (112).

[0023] Laser energy transmitted along the beam path (116) through the scan lens (112) is transmitted along the beam axis (118) to the workpiece (102). The laser energy transmitted along the beam axis (118) may be characterized as having a Gaussian-type spatial intensity profile or a non-Gaussian-type (i.e., "shaped") spatial intensity profile (e.g., a "top-hat" spatial intensity profile). Regardless of the type of spatial intensity profile, the spatial intensity profile may be characterized as the shape of the beam of laser energy transmitted along the beam axis (118) (or beam path (116)) (i.e., the cross-sectional shape also referred to herein as the "spot shape"), which may be circular, elliptical, square, rectangular, triangular, hexagonal, ring-shaped, or any other shape. As used herein, the term “spot size” refers to the diameter or maximum spatial width of a beam of laser energy delivered at a location where the beam axis (118) intersects the area of ​​the workpiece (102) to be processed at least partially by the beam of delivered laser energy (also referred to as “process spot,” “spot location,” or more simply “spot”). For the purposes of discussion herein, the spot size is such that, from the beam axis (118), the optical intensity is at least 1 / e of the optical intensity at the beam axis (118). 2It is measured as the radiation or transverse distance to the point where it falls. Generally, the spot size of the laser energy beam will be minimal at the beam waist. Once delivered to the workpiece (102), the laser energy within the beam may be characterized as striking the workpiece (102) with a spot size ranging from 2 μm to 200 μm. However, it will be understood that the spot size may be smaller than 2 μm or larger than 200 μm. Thus, the laser energy beam delivered to the workpiece (102) may have a spot size greater than, smaller than, or equal to, or between any of these values, 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.

[0024] Generally, the aforementioned positioners (e.g., first positioner (106), second positioner (108), and third positioner (110)) are configured to change the relative position between the spot and the workpiece (102). With consideration of the following description, it should be recognized that if the device (100) includes the second positioner (108), the third positioner (110), or a combination thereof, the inclusion of the first positioner (106) is optional (i.e., the device (100) does not need to include the first positioner (106). Similarly, if the device (100) includes the first positioner (106), the third positioner (110), or a combination thereof, the inclusion of the second positioner (108) is optional. Furthermore, it should be similarly recognized that if the device (100) includes a first positioner (106), a second positioner (108), or a combination thereof, the inclusion of a third positioner (110) is optional. Finally, where appropriate, it should be recognized that the device (100) may include only the first positioner (106), only the second positioner (108), or only the third positioner (110).

[0025] The device (100) also includes one or more optical components (e.g., beam expanders, beam shapers, apertures, filters, collimators, lenses, mirrors, polarizers, waveplates, diffractive optical elements, refractive optical elements, etc., or any combination thereof) to focus, expand, collimate, shape, polarize, filter, split, combine, crop, or otherwise modify, condition, or orient a beam of laser energy obtained from a laser source (104) along one or more beam paths (e.g., beam path (116)) to a scan lens (112). These optical components can be inserted into the beam path (116) at any suitable or desired location (e.g., between the laser source (104) and the first positioner (106), between the laser source (104) and the second positioner (108), between the first positioner (106) and the second positioner (108), between the second positioner (108) and the scan lens (112), etc., or any combination thereof).

[0026] One example of such an optical component is a variable optical attenuator (VOA) configured to selectively and variably reduce the power of laser pulses propagating along a beam path (116). Examples of VOAs that can be integrated include one or more systems such as a variable neutral density filter, an acousto-optic (AO) modulator (AOM), an AO deflector (AOD), a liquid crystal variable attenuator (LCVA), a microelectromechanical system (MEMS)-based VOA, an optical attenuator wheel, a polarizer / waveplate filter, or any combination thereof.

[0027] Another example of such an optical component is a beam size adjustment mechanism that operates to selectively and variably adjust the size of the beam of laser energy incident on the scan lens (112) (also referred to herein as “beam size”). As used herein, the term “beam size” refers to the diameter or width of the beam of laser energy and may be measured as a radiation or transverse distance from the beam axis (118) to where the optical intensity drops to at least 1 / e2 of the optical intensity along the axis propagating along the beam path (116). Examples of beam size adjustment mechanisms that may be integrated include an AOD system, a zoom lens, a motorized variable beam expander, a deformable mirror, a variable radius mirror, a variable focus moiré lens, a motorized Z-axis lens, a motorized aperture, a motorized aperture wheel, or any combination thereof. Adjusting the beam size of the beam of laser energy incident on the scan lens (112) may result in a change in the spot size in the workpiece (102).

[0028] Another example of such an optical component is a beam shape adjustment mechanism that operates to selectively and variably adjust the shape of the beam of laser energy incident on the scan lens (112) (also referred to herein as "beam size"). Examples of beam shape adjustment mechanisms that may be integrated include an AOD, a deformable mirror, a variable radius mirror, a variable focus moiré lens, or any combination thereof. Adjusting the beam shape of the beam of laser energy incident on the scan lens (112) may result in a change in the spot shape in the workpiece (102).

[0029] A. Laser One

[0030] In one embodiment, the laser source (104) operates to generate laser pulses. As such, the laser source (104) may include a pulse 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 or CW laser source, the laser source (104) may further include a pulse gating unit (e.g., an acousto-optic (AO) modulator (AOM), a beam chopper, etc.) for temporally modulating a beam of laser radiation output from the QCW or CW laser source. Although not illustrated, the device (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 without including a pulse gating unit. Accordingly, the laser source (104) can be broadly characterized as operating to generate a beam of laser energy, which may appear as a series of laser pulses or as a continuous or semi-continuous laser beam, which may then propagate along the beam path (116). While many embodiments discussed herein refer to laser pulses, it should be recognized that continuous beams may be used alternatively or additionally whenever appropriate.

[0031] Laser light in the UV range of the electromagnetic spectrum may have one or more wavelengths in the range of 10 nm (or its vicinity) to 385 nm (or its vicinity), such as 10 nm, 121 nm, 124 nm, 157 nm, 200 nm, 334 nm, 337 nm, 351 nm, 380 nm, etc., or any of these values. Laser light in the visible green range of the electromagnetic spectrum may have one or more wavelengths in the range of 500 nm (or its vicinity) to 560 nm (or its vicinity), such as 511 nm, 515 nm, 530 nm, 532 nm, 543 nm, 568 nm, etc., or any of these values. Laser light in the IR range of the electromagnetic spectrum may have a range of 750 nm (or its vicinity) to 15 μm (or its vicinity), for example, 600 nm to 1000 nm, 752.5 nm, 780 nm to 1060 nm, 799.3 nm, 980 nm, 1047 nm, 1053 nm, 1060 nm, 1064 nm, 1080 nm, 1090 nm, 1152 nm, 1150 nm to 1350 nm, 1540 nm, 2.6 μm to 4 μm, 4.8 μm to 8.3 μm, 9.4 μm, 10.6 μm, etc., or one or more wavelengths between any of these values.

[0032] Laser pulses output by the laser source (104) may have a pulse width or pulse duration in the range of 10 fs to 900 ms (i.e., based on the full width at half maximum (FWHM) of the optical power within the pulse versus time). However, it will be understood that the pulse duration may be less than 10 fs or greater than 900 ms. Accordingly, 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, 100ns, 200ns, 400ns, 800ns, The pulse duration may be less than, greater than or equal to, or between any of these values, such as 1000ns, 2μs, 5μs, 10μs, 50μs, 100μs, 300μs, 500μs, 900μs, 1ms, 2ms, 5ms, 10ms, 20ms, 50ms, 100ms, 300ms, 500ms, 900ms, 1s, etc.

[0033] The laser pulses output by the laser source (104) may have an average power in the range of 5 mW to 50 kW. However, it will be understood that the average power may be less than 5 mW or greater than 50 kW. Accordingly, the laser pulses output by the laser source (104) may have an average power that is less than, greater than or equal to, or between any of these values, 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.

[0034] Laser pulses can be output by the laser source (104) at a pulse repetition rate in the range of 5 kHz to 1 GHz. However, it will be understood that the pulse repetition rate may be less than 5 kHz or greater than 1 GHz. Accordingly, laser pulses can be output by the laser source (104) at a pulse repetition rate that is smaller than, greater than or equal to, or between any of these values, such as 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.

[0035] In addition to wavelength, pulse duration, average power, and pulse repetition rate, laser pulses delivered to the workpiece (102) may be characterized by one or more other characteristics, such as pulse energy, peak power, etc., which can be selected (e.g., based on one or more other characteristics such as wavelength, pulse duration, average power, and pulse repetition rate) to irradiate the workpiece (102) at the process spot with sufficient optical intensity (measured in W / cm2), fluence (measured in J / cm2), etc., to process the workpiece (102) (e.g., to form one or more features having one or more desired characteristics).

[0036] In examples of types of lasers, the laser source (104) may be characterized as 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-state bulk or fiber lasers, dye lasers, mode-locked diode lasers, pulsed lasers (e.g., ms-, ns-, ps-, fs-pulse lasers), CW lasers, QCW lasers, etc., or any combination thereof. Depending on their configuration, gas lasers (e.g., carbon dioxide lasers, 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 a laser source (104) include lasers of the BOREAS, HEGOA, SIROCCO, or CHINOOK series manufactured by EOLITE; lasers of the PYROFLEX series manufactured by PYROPHOTONICS; lasers of the PALADIN Advanced 355, DIAMOND series (e.g., DIAMOND E, G, J-2, J-3, J-5 series), FLARE NX, MATRIX QS DPSS, MEPHISTO Q, AVIA LX, AVIA NX, RAPID NX, HYPERRAPID NX, RAPID, HELIOS, FIDELITY, MONACO, OPERA, or RAPID FX series manufactured by COHERENT;Lasers of the ASCEND, ELEMENT 2, ELEMENT 2 CEP4, EXCELSIOR, EXPLORER, HIPPO, ICEFYRE, NAVIGATOR, QUATA-RAY, QUASAR, SPIRIT, SPIRIT 1030-100, SPIRIT 1030-70, SPIRIT 515-50, TALON, or VGEN series manufactured by SPECTRA PHYSICS; lasers of the PULSTAR- or FIRESTAR- series manufactured by SYNRAD; All TRUFLOW-series lasers manufactured by TRUMPF (e.g., TRUFLOW 2000, 1700, 3000, 3200, 3600, 4000, 5000, 6000, 6000, 8000, 10000, 12000, 15000, 20000), TRUCOAX series lasers (e.g., TRUCOAX 1000), or TRUDISK, TRUPULSE, TRUDIODE, TRUFIBER, or TRUMICRO series lasers; FCPA μJEWEL or FEMTOLITE series lasers manufactured by IMRA AMERICA; TANGERINE and SATSUMA series lasers manufactured by AMPLITUDE SYSTEMES (and MIKAN and T-PULSE series oscillators);It comprises one or more laser sources such as CL, CLPF, CLPN, CLPNT, CLT, ELM, ELPF, ELPN, ELPP, ELR, ELS, FLPN, FLPNT, FLT, GLPF, GLPN, GLR, HLPN, HLPP, RFL, TLM, TLPN, TLR, ULPN, ULR, VLM, VLPN, YLM, YLPF, YLPN, YLPP, YLR, YLS, FLPM, FLPMT, DLM, BLM, or DLR series lasers (e.g., including GPLN-100-M, GPLN-500-QCW, GPLN-500-M, GPLN-500-R, GPLN-2000-S, etc.) manufactured by IPG PHOTONICS, or any combination thereof.

[0037] B. First positioner

[0038] A first positioner (106) is arranged, positioned, or otherwise placed within a beam path (116) and operates to diffract, reflect, refract, or any combination thereof (i.e., to "deflect" the laser pulses) laser pulses generated by a laser source (104) to deflect or impart movement of the beam path (116) (e.g., relative to a scan lens (112)), and consequently deflect or impart movement of the beam axis (118) relative to the workpiece (102). Generally, the first positioner (106) operates to impart movement of the beam axis (118) relative to the workpiece (102) (e.g., along the X-axis (or direction), Y-axis (or direction), or a combination thereof within a first scanning range projected onto the workpiece (102) by the scan lens (112). Although not explicitly stated, the X-axis (or X-direction) will be understood to refer to an axis (or direction) orthogonal to the illustrated Y-axis and Z-axis (or directions).

[0039] Generally, and depending on one or more factors such as the configuration of the first positioner (106), the position of the first positioner (106) along the beam path (116), the beam size of the laser pulses incident on the first positioner (106), the spot size, etc., the first scanning range may be extended in any direction of the X direction or Y direction to a distance of 0.01 mm, 0.04 mm, 0.1 mm, 0.5 mm, 1.0 mm, 1.4 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.2 mm, 5 mm, 10 mm, 25 mm, 50 mm, 60 mm, etc., or any distance between these values ​​that is smaller, larger, or equal to. The maximum dimension of the first scanning range (e.g., in the X direction or Y direction or otherwise) may be greater than, equal to, or smaller than the maximum dimension (measured in the XY plane) of the feature (e.g., opening, recess, via, trench, etc.) to be formed on the workpiece (102).

[0040] Generally, the rate at which the first positioner (106) can position a process spot at any location within the first scanning range (thus moving the beam axis (118)) (also referred to as the “positioning rate”) is in the range of 8 kHz (or around it) to 250 MHz (or around it). This range is also referred to herein as the first positioning bandwidth. For example, the first positioning bandwidth may be 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, etc., or greater than, equal to, or less than any of these values. The inverse of the positioning rate is referred to herein as the “positioning period” and refers to the minimum amount of time required to change the position of a process spot from one position within the first scanning range to any other position within the first scanning range. Accordingly, the first positioner (106) may be characterized by having a positioning period greater than, equal to, or smaller than any of these values, such as 200μs, 125μs, 100μs, 50μs, 33μs, 12.5μs, 10μs, 4μs, 2μs, 1.3μs, 1μs, 0.2μs, 0.1μs, 0.05μs, 0.025μs, 0.02μs, 0.013μs, 0.01μs, 0.008μs, 0.0067μs, 0.0057μs, 0.0044μs, 0.004μs, etc.

[0041] The first positioner (106) may be provided as a micro-electromechanical system (MEMS) mirror or mirror array, an AOD system, an electro-optical deflector (EOD) system, a high-speed steering mirror (FSM) element (e.g., integrating a piezoelectric actuator, an electro-strictive actuator, a voice coil actuator, etc.), a galvanometer mirror system, a rotating polygonal scanner, etc., or any combination thereof. In one embodiment, the first positioner (106) is provided as an AOD system comprising at least one (e.g., one, two, three, four, etc.) single-element AOD system, at least one (e.g., one, two, three, four, etc.) phase array AOD system, etc., or any combination thereof. Each of the single-element or phase array AOD systems comprises an AO cell formed of a material such as crystalline Ge, PbMoO4 or TeO2, glassy SiO2, quartz, As2S3, etc. As used herein, a “single element” AOD system refers to an AOD system having only a single ultrasonic transducer element acoustically coupled to an AO cell, whereas a “phase array” AOD system includes a phase array of at least two ultrasonic transducer elements acoustically coupled to a common AO cell.

[0042] As recognized by those skilled in the art, AO technologies (e.g., AODs, AOMs, etc.) modulate one or more characteristics of a light wave (i.e., a beam of laser energy in the context of this application) that propagates simultaneously through an AO cell by utilizing diffraction effects caused by acoustic waves propagating through an AO cell. Generally, an AO cell can support both acoustic waves and light waves in the same area. Acoustic waves impart perturbation to the refractive index of the AO cell. Acoustic waves are generally launched into the AO cell by driving ultrasonic transducer elements at one or more RF frequencies. By controlling the characteristics of the acoustic waves (e.g., amplitude, frequency, phase, etc.), one or more characteristics of the propagating light wave can be controllably modulated to impart a shift in the beam path (116) (e.g., for a scan lens (112)). Additionally, the characteristics of the acoustic waves emitted into the AO cell can be controlled using well-known techniques to attenuate the energy of the laser beam as it passes through the AO cell. Thus, the AOD system can also be operated to modulate the pulse energy of the laser pulses (and correspondingly the fluence, peak power, optical intensity, average power, etc.) that are ultimately delivered to the workpiece (102).

[0043] Any AOD systems may be provided as a single-axis AOD system (operating to impart movement of the beam axis (118) along a single direction, for example, by deflecting the beam path (116) or as a multi-axis AOD system (operating to impart movement of the beam axis (118) along one or more axes, for example, along the X-axis, along the Y-axis, or any combination thereof). Generally, a multi-axis AOD system may be provided as a multi-cell system or a single-cell system. A multi-cell, multi-axis system generally comprises a number of AOD systems, each operating to impart movement of the beam axis (118) along a different axis. For example, a multi-cell, multi-axis system may include a first AOD system (e.g., a single-element or phase array AOD system) (e.g., "X-axis AOD system") that operates to impart movement of the beam axis (118) along the X-axis, and a second AOD system (e.g., a single-element or phase array AOD system) (e.g., "Y-axis AOD system") that operates to impart movement of the beam axis (118) along the Y-axis. A single-cell, multi-axis system (e.g., "X / Y-axis AOD system") generally includes a single AOD system that operates to impart movement of the beam axis (118) along the X-axis and Y-axis. For example, a single-cell system may include at least two ultrasonic transducer elements acoustically coupled to orthogonally arranged planes, faces, sides, etc. of a common AO cell.

[0044] C. Second positioner

[0045] A second positioner (108) is positioned in the beam path (116) and operates to diffract, reflect, refract, or any combination thereof (i.e., to “deflect” the laser pulses) generated by the laser source (104) and passed by the first positioner (106), thereby deflecting or imparting movement of the beam path (116) (e.g., to the scan lens (112)), and consequently deflecting or imparting movement of the beam axis (118) relative to the workpiece (102). Generally, the second positioner (108) operates to impart movement of the beam axis (118) relative to the workpiece (102) (e.g., along the X-axis (or direction), Y-axis (or direction), or a combination thereof within a second scanning range projected onto the workpiece (102) by the scan lens (112).

[0046] Generally, and depending on one or more factors such as the configuration of the second positioner (108), the position of the second positioner (108) along the beam path (116), the beam size of the laser pulses incident on the second positioner (108), the spot size, etc., the second scanning range may be extended in any direction of the X direction or the Y direction to a distance greater than the corresponding distance of the first scanning range. In the above view, the second scanning range may be extended in any direction of the X direction or the Y direction to a distance of 1 mm, 25 mm, 50 mm, 75 mm, 100 mm, 250 mm, 500 mm, 750 mm, 1 cm, 25 cm, 50 cm, 75 cm, 1 m, 1.25 m, 1.5 m, etc., or a distance less than, greater than, or equal to any of these values. The maximum dimension of the second scanning range (e.g., in the X direction or Y direction or otherwise) may be greater than, equal to, or smaller than the maximum dimension (measured in the XY plane) of the feature to be formed on the workpiece (102) (e.g., opening, recess, via, trench, scribe line, conductive trace, etc.).

[0047] Considering the configuration described herein, it should be recognized that the movement of the beam axis (118) provided by the first positioner (106) may be superimposed by the movement of the beam axis (118) provided by the second positioner (108). Accordingly, the second positioner (108) operates to scan the first scanning range within the second scanning range.

[0048] Generally, the positioning rate at which the second positioner (108) can position a process spot at any location within the second scanning range (thus moving the beam axis (118) within the second scanning range and / or scanning the first scanning range within the second scanning range) spans a range smaller than 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 it) to 8 kHz (or around it). For example, the second positioning bandwidth may be 500 Hz, 750 Hz, 1 kHz, 1.25 kHz, 1.5 kHz, 1.75 kHz, 2 kHz, 2.5 kHz, 3 kHz, 3.5 kHz, 4 kHz, 4.5 kHz, 5 kHz, 5.5 kHz, 6 kHz, 6.5 kHz, 7 kHz, 7.5 kHz, 8 kHz, etc., or greater than, equal to, or less than any of these values.

[0049] With the above in mind, it should be understood that the second positioner (108) may be provided as a micro-electromechanical system (MEMS) mirror or mirror array, an AOD system, an electro-optical deflector (EOD) system, a high-speed steering mirror (FSM) element (e.g., integrating a piezoelectric actuator, an electro-deformation actuator, a voice coil actuator, etc.), a galvanometer mirror system, a resonant scanning mirror system, a rotating polygonal scanner, etc., or any combination thereof. In one embodiment, the second positioner (108) may be provided as a galvanometer mirror system comprising two galvanometer mirror components, namely, a first galvanometer mirror component (e.g., an X-axis galvanometer mirror component) arranged to provide movement of the beam axis (118) for the workpiece (102) along the X-axis and a second galvanometer mirror component (e.g., a Y-axis galvanometer mirror component) arranged to provide movement of the beam axis (118) for the workpiece (102) along the Y-axis. However, in another embodiment, the second positioner (108) may be provided as a galvanometer mirror system comprising a single galvanometer mirror component arranged to provide movement of the beam axis (118) for the workpiece (102) along the X-axis and Y-axis. In other embodiments, the second positioner (108) may be provided as a rotating polygonal mirror system, etc. Therefore, it will 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.

[0050] D. Third position designator

[0051] The third positioner (110) operates to impart movement of the workpiece (102) relative to the scan lens (112), and consequently impart movement of the workpiece (102) relative to the beam axis (118). Movement of the workpiece (102) relative to the beam axis (118) is generally limited so that the process spot can be scanned, moved, or otherwise positioned within the third scan field or "third scanning range." Depending on one or more factors, such as the configuration of the third positioner (110), the third scanning range may extend to a distance greater than or equal to the corresponding distance of the second scanning range in either the X direction or the Y direction. However, generally, the maximum dimension of the third scanning range (e.g., in the X direction or the Y direction, or otherwise) will be greater than or equal to the corresponding maximum dimension (measured in the XY plane) of any feature to be formed on the workpiece (102). Optionally, the third positioner (110) may be operated to move the workpiece (102) with respect to the beam axis (118) within a scanning range extending in the Z direction (e.g., over a range of 1 mm to 50 mm). Thus, the third scanning range may extend along the X direction, the Y direction, and / or the Z direction.

[0052] With regard to the configuration described herein, it should be recognized that the movement of the process spot for the workpiece (102) (e.g., granted by the first positioner (106) and / or the second positioner (108)) may overlap with the movement of the workpiece (102) granted by the third positioner (110). Accordingly, the third positioner (110) operates to scan the first scanning range and / or the second scanning range within the third scanning range. Generally, the positioning rate at which the third positioner (110) can position the workpiece (102) at any location within the third scanning range (thus moving the workpiece (102), scanning the first scanning range within the third scanning range and / or scanning the second scanning range within the third scanning range) spans a range 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 it). For example, the third positioning bandwidth may be equal to or smaller than 500 Hz, 250 Hz, 150 Hz, 100 Hz, 75 Hz, 50 Hz, 25 Hz, 10 Hz, 7.5 Hz, 5 Hz, 2.5 Hz, 2 Hz, 1.5 Hz, 1 Hz, etc., or any value between these values.

[0053] In one embodiment, the third positioner (110) is provided as one or more linear stages (e.g., each may impart translational movement to the workpiece (102) along the X direction, Y direction and / or Z direction), one or more rotational stages (e.g., each may impart rotational movement to the workpiece (102) around an axis parallel to the X direction, Y direction and / or Z direction), 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 (and thus movable along the X direction by the X stage) for moving the workpiece (102) along the Y direction.

[0054] Although not illustrated, the device (100) may optionally include a fixture (e.g., a chuck) coupled to the stage of the third positioner (110). The fixture may include a support area, and the workpiece (102) may be mechanically clamped, fixed, held, or attached to the fixture, or otherwise supported by the fixture within the support area. In one embodiment, the workpiece (102) may be clamped, fixed, held, or attached, or otherwise supported so as to make direct contact with the main, typically flat, support surface of the fixture. In another embodiment, the workpiece (102) may be clamped, fixed, held, or attached, or otherwise supported so as to be spaced apart from the support surface of the fixture. In one embodiment, the workpiece (102) may be fixed, held, or attached by a force (e.g., electrostatic force, vacuum force, magnetic force) that is optionally applied to the workpiece (102) from the fixture or otherwise exists between the workpiece (102) and the fixture.

[0055] As described so far, the device (100) uses a so-called "stacked" positioning system as a third positioner (110), which allows the workpiece (102) to be moved while the positions of other components, such as the first positioner (106), the second positioner (108), the scan lens (112), etc., remain stationary within the device (100) relative to the workpiece (102) (e.g., through one or more supports, frames, etc., as is known in the art). In another embodiment, 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), etc., and the workpiece (102) may remain stationary.

[0056] In another embodiment, the third positioner (110) may be provided as a so-called “divided stage” positioning system in which one or more components, such as the first positioner (106), the second positioner (108), the scan lens (112), etc., or any combination thereof, are transported by one or more linear or rotary stages (e.g., mounted on a frame, gantry, etc.) and the workpiece (102) is transported by one or more other linear or rotary stages. In this embodiment, the third positioner (110) includes one or more linear or rotary stages arranged and operated to move one or more components, such as the second positioner (108) and the scan lens (112), and one or more linear or rotary stages arranged and operated to move the workpiece (102). For example, the third positioner (110) may include a Y stage for giving movement of the workpiece (102) along the Y direction and an X stage for giving movement of the scan head along the X direction. Some examples of segmented stage positioning systems that may be used beneficially or advantageously in the device (100) include any of the ones disclosed in U.S. Patent Nos. 5,751,585, 5,798,927, 5,847,960, 6,606,999, 7,605,343, 8,680,430, 8,847,113 or U.S. Patent Application No. 2014 / 0083983 or any combination thereof.

[0057] In one embodiment in which the third positioner (110) includes a Z stage, the Z stage may be arranged and configured to move the workpiece (102) along the Z direction. In this case, the Z stage may be carried by one or more other aforementioned stages for moving or positioning the workpiece (102), may carry one or more other aforementioned stages for moving or positioning the workpiece (102), or may be any combination thereof. In another embodiment in which the third positioner (110) includes a Z stage, the Z stage may be arranged and configured to move the scan lens (112) along the Z direction. Thus, when the third positioner (110) is provided as a split stage positioning system, the Z stage may carry the X stage or be carried by it. Moving the workpiece (102) or the scan lens (112) along the Z direction may result in a change in the spot size of the workpiece (102).

[0058] In another embodiment, one or more components, such as a first positioner (106), a second positioner (108), a scan lens (112), etc., may be carried by an articulated multi-axis robot arm (e.g., a 2-, 3-, 4-, 5-, or 6-axis arm). In this embodiment, the second positioner (108) and / or the scan lens (112) may optionally be carried by an end effector of the robot arm. In another embodiment, the workpiece (102) may be carried directly on the end effector of the articulated multi-axis robot arm (i.e., without the third positioner (110)). In another embodiment, the third positioner (110) may be carried on the end effector of the articulated multi-axis robot arm.

[0059] D. Scan Lens

[0060] A scan lens (112) (provided, for example, as a simple lens or a composite lens) is configured to focus laser pulses typically directed along a beam path to create a beam waist that can generally be positioned 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 created that yield a plurality of process spots displaced from each other along the beam axis (118)), etc., or any combination thereof. In one embodiment, the scan lens (112) is provided as a fixed focal length lens and is coupled to a scan lens positioner (e.g., a lens actuator, not shown) that operates to move the scan lens (112) (e.g., to change the position of the beam waist along the beam axis (118)). For example, the lens actuator may be provided as a negative coil that operates to linearly translate the scan lens (112) along the Z direction. In this case, the scan lens (112) may be formed from materials such as fused silica, optical glass, zinc selenide, zinc sulfide, germanium, gallium arsenide, magnesium fluoride, etc. In another embodiment, the scan lens (112) is provided as a variable focal length lens (e.g., a zoom lens or a so-called "liquid lens" incorporating technologies currently provided by COGNEX, VARIOPTIC, etc.) that can be actuated (e.g., via the lens actuator) to change the position of the beam waist along the beam axis (118). Changing the position of the beam waist along the beam axis (118) may result in a change in the spot size in the workpiece (102).

[0061] In one embodiment, the scan lens (112) and the second positioner (108) are integrated into a common housing or "scan head." Thus, in an embodiment where the device (100) includes a lens actuator, the lens actuator may be coupled to the scan lens (112) (e.g., to enable movement of the scan lens (112) within the scan head relative to the second positioner (108)). Alternatively, the lens actuator may be coupled to the scan head (e.g., to enable movement of the scan head itself—in which case the scan lens (112) and the second positioner (108) would move together). In another embodiment, the scan lens (112) and the second positioner (108) are integrated into different housings (e.g., so that the housing in which the scan lens (112) is integrated is movable relative to the housing in which the second positioner (108) is integrated). The components of the scan head or the entire scan head itself can be configured as a modular assembly so that the components of the scan head can be simply removed and replaced with other components, allowing one scan head to be simply removed and replaced with another scan head, etc.

[0062] E. Vision

[0063] The device (100) may further include one or more cameras, such as a camera (113) having a field of view that includes an area occupied by a workpiece (102) provided to the device (100) for processing (e.g., a CCD camera, a CMOS camera, etc., or any combination thereof). The camera (113) may be coupled to a scan lens (112) or the scan head described above. In another embodiment, where a third positioner (110) is provided as a segmented stage positioning system, the camera (113) may be coupled to any stage arranged and operated to move the scan lens (112) or the scan head (instead of the scan lens (112) or the scan head itself). In yet another embodiment, the device (100) may include a structure such as a frame, a gantry, etc. (generally referred to herein as an “inspection support”), and the camera (113) may be coupled to the inspection support. In this embodiment, the device (100) may include one or more linear or rotary stages for moving an inspection support (e.g., with respect to a workpiece (102)), for moving a camera (113), etc. (e.g. with respect to an inspection support), or for any combination thereof. The camera (113) may generate image data representing an image captured within its field of view and output the image data (e.g., as one or more image signals) to a controller (114).

[0064] Image data is interpreted, manipulated, input into an algorithm, or otherwise processed in any desired or otherwise suitable manner known in the art (e.g., in a controller (114), a remote system (126), etc., or any combination thereof) to facilitate one or more operations such as alignment, calibration, visual inspection (e.g., features formed as a result of processing the workpiece (102)) or any combination thereof of workpieces (102) within the device (100). Any camera (e.g., camera (113)) that generated the image data may be considered part of the “inspection system” insofar as the image data is used to facilitate an inspection process (e.g., a visual inspection process). Thus, the inspection system may include a single camera or multiple cameras.

[0065] Although FIG. 1 illustrates the device (100) as comprising only one camera (113), it will be understood that multiple cameras (113) may be included (different in terms of resolution, field of view, etc., or any combination thereof). For example, in one embodiment, the device (100) may include a first camera and a second camera. The first camera may have a relatively large field of view and a relatively low resolution, while the second camera may have a relatively small field of view and a relatively high resolution. Generally, the field of view of the second camera will be located within the field of view of the first camera. However, the first camera and the second camera may be arranged such that the field of view of the second camera is located outside the field of view of the first camera. Furthermore, the camera (113) may have a field of view wider than the first scanning range or the second scanning range as projected onto the workpiece (102).

[0066] Furthermore, although not illustrated, the device (100) may include a lighting system (e.g., any suitable machine vision lighting system known in the art) that operates to illuminate the field of view of a camera (e.g., camera (113)).

[0067] In the illustrated embodiment, the camera (113) is laterally offset from the scan lens (112). Thus, the field of view of the camera (113) (i.e., as projected onto the workpiece (102)) may be at least partially located outside the scan field projected onto the workpiece (102) by the scan lens (112). In another embodiment, the device (100) may include one or more optical components (e.g., one or more beam splitters, mirrors, lenses, etc., or any combination thereof) in any manner known in the art that enables the field of view of the camera (e.g., camera (113)) to be projected through the scan lens (112).

[0068] F. Controller

[0069] Generally, the device (100) includes one or more controllers, such as a controller (114), to control or facilitate the operation of the device (100). In one embodiment, the controller (114) is communicably coupled 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 scan lens (112) (if provided as a variable focal length lens), a fixture, a camera (113), a VOA, a beam size adjustment mechanism, etc. (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, etc., or any combination thereof), and operates in response to one or more control signals output by the controller (114).

[0070] For example, the controller (114) may control the operation of the first positioner (106), the second positioner (108), or the third positioner (110) to impart relative movement between the beam axis and the workpiece (102), thereby causing relative movement between the process spot and the workpiece (102) along a path or trajectory (also referred to herein as a “process trajectory”) within the workpiece (102). In another example, and as described in more detail below, the controller (114) may control the operation of the third positioner (110) to impart relative movement between the camera (113) and the workpiece (102) after the workpiece (102) has been processed, so as to enable inspection of features formed on the workpiece (102) as a result of processing.

[0071] Generally, the controller (114) includes one or more processors that operate to generate the aforementioned control signals when executing instructions. The processor may be provided as a programmable processor (e.g., one or more general-purpose computer processors, microprocessors, digital signal processors, etc., or any combination thereof) that operates to execute instructions. Instructions executable by the processor(s) may be implemented in any suitable form of circuit, including software, firmware, etc., or programmable logic devices (PLDs), field programmable gate arrays (FPGAs), field programmable object arrays (FPOAs), application-specific integrated circuits (ASICs) including digital, analog, and mixed analog / digital circuits, or any combination thereof. Execution of instructions may be performed on a single processor, distributed among processors, across processes within a device, or in parallel across a network of devices, or through any combination thereof.

[0072] In one embodiment, the controller (114) includes a tangible medium, such as computer memory, accessible by a 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 drive, 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 accessed locally, remotely (e.g., via a network), or a combination thereof. Generally, instructions may be stored as computer software (e.g., executable code, files, instructions, etc., library files, etc.), which can be easily authored by those skilled in the art from the descriptions provided herein, and may be written in, for example, C, C++, Visual Basic, Java, Python, Tel, Perl, Scheme, Ruby, assembly language, hardware description language (e.g., VHDL, VERILOG, etc.). Computer software is generally stored in one or more data structures delivered by computer memory.

[0073] Although not illustrated, one or more drivers (e.g., RF drivers, servo drivers, line drivers, power supplies, etc.) may be communicably coupled to the input of one or more components such as a laser source (104), a first positioner (106), a second positioner (108), a third positioner (110), a lens actuator, a scan lens (112) (if provided as a variable focal length lens), a fixture, a camera (113), a VOA, a beam size adjustment mechanism, etc. In one embodiment, each driver generally includes an input to which a controller (114) is communicably coupled, and the controller (114) thereby operates to generate one or more control signals (e.g., trigger signals, etc.) that can be transmitted to the input(s) of one or more drivers associated with one or more components of the device (100). Accordingly, components such as a laser source (104), a first positioner (106), a second positioner (108), a third positioner (110), a lens actuator, a scan lens (112) (if provided as a variable focal length lens), a fixture, a camera (113), a VOA, a beam size adjustment mechanism, etc. respond to control signals generated by a controller (114).

[0074] In other embodiments, and although not illustrated, one or more additional controllers (e.g., component-specific controllers) may optionally be communicably coupled to the input of a driver communicably coupled to (and thus associated with) a component such as a laser source (104), a first positioner (106), a second positioner (108), a third positioner (110), a lens actuator, a scan lens (112) (if provided as a variable focal length lens), a fixture, a camera (113), a VOA, a beam size adjustment mechanism, etc. In this embodiment, each component-specific controller may be communicably coupled to a controller (114) and may operate to generate one or more control signals (e.g., trigger signals, etc.) in response to one or more control signals received from the controller (114)—which may then be transmitted to the input(s) of the communicably coupled driver(s). In this embodiment, the component-specific controller may operate similarly to that described for the controller (114).

[0075] In another embodiment in which one or more component-specific controllers are provided, a component-specific controller associated with one component (e.g., a laser source (104)) may be communicably coupled to a component-specific controller associated with one component (e.g., a first positioner (106), etc.). In this embodiment, one or more of the component-specific controllers may be operated to generate one or more control signals (e.g., trigger signals, etc.) in response to one or more control signals received from one or more other component-specific controllers.

[0076] G. User Interface

[0077] The device (100) may further include a user interface (120) that is communicably coupled to the controller (114) (e.g., via one or more wired or wireless, serial or parallel communication links such as USB, RS-232, Ethernet, Firewire, Wi-Fi, RFID, NFC, Bluetooth, Li-Fi, SERCOS, MARCO, EtherCAT, etc., or any combination thereof). The user interface (120) may include one or more output devices, one or more input devices, or any combination thereof. Generally, an output device is any device capable of rendering or otherwise conveying information through stimuli that any person can perceive (e.g., visual, auditory, tactile, etc.). Examples of output devices include monitors, printers, speakers, haptic actuators, etc. Generally, an input device is any device that enables a user of the device (100), for example, to provide commands, commands, parameters, information, etc., to operate the device (100) (or to facilitate the operation of the device (100). Examples of input devices include a keyboard, mouse, touchpad, touchscreen, microphone, camera, etc.

[0078] H. Communication Module

[0079] Optionally, the device (100) includes a communication module (122) coupled to the controller (114) so ​​as to be communicable (e.g., via one or more wired or wireless, serial or parallel communication links such as USB, RS-232, Ethernet, FireWire, Wi-Fi, RFID, NFC, Bluetooth, Li-Fi, SERCOS, MARCO, EtherCAT, etc. or any combination thereof). The communication module (122) operates to transmit data, receive data, or perform a combination thereof. Accordingly, the communication module (122) may include circuits, antennas, connectors, etc., or any combination thereof, to transmit and / or receive data to another device or network (e.g., network (124)) via a wired or wireless link. In one example, the communication module (122) may be a connector that operates with the software or firmware of the controller (114) to function as a serial port (e.g., RS232), a Universal Serial Bus (USB) port, an IR interface, etc., or any combination thereof. In another example, the communication module (122) may be a Universal Interface Driver Application Specific Integrated Circuit (UIDA) that supports a plurality of different host interface protocols, such as RS-232C, IBM46XX, keyboard wedge interface, etc., or any combination thereof. The communication module (122) may include one or more modules, circuits, antennas, connectors, etc., as is known in the art, to support other known communication modes, such as USB, Ethernet, Bluetooth, Wi-Fi, infrared (e.g., IrDa), RFID communication, etc., or any combination thereof. It will be understood that instead of being a separate component from the controller (114), the communication module (122) may be integrated as part of the controller (114) in any known or suitable manner.

[0080] The network (124) may be coupled to communicate with one or more systems remote to the device (100) (e.g., remote system (126) as identified in FIG. 1) (e.g., via one or more wired or wireless, serial or parallel communication links such as USB, RS-232, Ethernet, FireWire, Wi-Fi, RFID, NFC, Bluetooth, Li-Fi, SERCOS, MARCO, EtherCAT, etc. or any combination thereof). In one embodiment, the remote system (126) may be a device such as a computer (e.g., desktop computer, laptop computer, tablet computer, smartphone, etc.), a computing system (e.g., cloud computing platform), another controller or communication module (e.g., associated with another device such as the device (100)), or any combination thereof. It should be understood that the remote system (126) may include or otherwise be coupled to a user interface comprising one or more output devices, one or more input devices, or any combination thereof, as described exemplarily above in relation to the user interface (12). The remote system (126) may be a device owned or otherwise operated by a user of the device (100), a manufacturer of the device (100), a technician responsible for performing maintenance on the device (100), or any combination thereof.

[0081] Through the communication module (122) and the network (124), the controller (114) can communicate various data to the remote system (126). Thus, examples of data that may be output to the remote system (126) include the aforementioned image data or measurement data (discussed in more detail below), or any combination thereof. Data output by the remote system (126) may be input to the controller (114) (e.g., through the network (124) and the communication module (122)) and may represent commands, instructions, parameters, information, etc., for operating the device (100) or otherwise influencing or facilitating any operation of the device (100).

[0082] I. Beam Characterization Tools

[0083] Optionally, the device (100) includes one or more beam characterizing tools, such as a beam characterizing tool (128), which operates to measure one or more characteristics of a beam of laser energy. Examples of characteristics that can be measured by the beam characterizing tool (128) include the spatial energy distribution, phase, polarization, power, etc., of a spot illuminated by the beam of incident laser energy in the beam characterizing tool (128), or any combination thereof. Accordingly, the beam characterizing tool (128) may be provided as at least one sensor selected from a group consisting of a slit sensor, a blade sensor, a camera (e.g., CCD, CMOS, etc.), a wavefront sensor (e.g., Shack-Hartmann wavefront sensor, etc.), or any other laser beam profiler known in the art, or any combination thereof. The beam characterizing tool (128) may generate measurement data representing one or more of the measured beam characteristics and output the measurement data (e.g., as one or more measurement signals) to the controller (114). Optionally, measurement data (or data derived from measurement data by, for example, the controller (114)) may be transmitted from the controller (114) to a remote system (126) (for example, via a communication module (122) and a network (124)).

[0084] As schematically illustrated in FIG. 1, a beam characterization tool (128) may be configured and arranged to measure one or more characteristics of a beam of laser energy (each also generally referred to herein as "beam characteristics") in any manner known in the art. For example, the beam characterization tool (128) is arranged to measure one or more characteristics of a beam of laser energy from a location along the beam path (116) (i.e., a sampling location) or at any combination thereof (e.g., as indicated by arrow 128a) at or near the location where the workpiece (102) is to be processed by the beam of laser energy (also referred to herein as a "process zone"). In one embodiment, the sampling location (e.g., as indicated by arrow 128b) may be between the second positioner (108) and the scan lens (112), between the first positioner (106) and the second positioner (108), between the laser source (104) and the first positioner (106), etc.

[0085] In another embodiment, the camera (113) (e.g., a first camera, a second camera, etc., or any combination thereof) may be operated to capture an image of a spot in the workpiece (102), a fixture, an area outside the fixture, etc., or any combination thereof. Then, in one embodiment, the captured image may be processed in the camera (113) so that the image data generated by the camera (113) represents the spatial energy distribution of the spot. In this case, the image data output by the camera (113) may be considered as "measurement data," and the camera (113) may be considered as an embodiment of a beam characterization tool (128).

[0086] J. Laser Sensor System

[0087] In one embodiment, the device (100) includes a laser sensor system configured to measure laser energy or power. For example, the laser sensor system may be attached to a chuck and configured to measure laser energy or power in a beam of laser energy delivered from a scan lens (112). In another example, the device (100) may include one or more optical components, such as a beam splitter, arranged in a beam path (116) and configured to divert a portion of the laser energy propagating along the beam path (116) to the laser sensor system. In this example, the laser sensor system may be configured to measure laser energy or power in the diverted portion of the laser energy. Measurement data generated by a laser sensor system (e.g., in response to measuring laser energy or power) is output to a controller (114) (and optionally a remote system (126)), whereby this data may be processed to support various operations such as real-time pulse energy control (e.g., to compensate for changes in laser power), system calibrations (e.g., to compensate for changes in transmission of RF power and frequency, etc. between AOD systems of the first positioner (106)), or any combination thereof. Examples of operations that may be implemented using measurement data from the laser sensor system are discussed in the aforementioned U.S. Patent No. 7,244,906 or the aforementioned U.S. Patent Application No. 2014 / 0196140, No. 2014 / 0263201 or No. 2014 / 0263223 or International Patent Application No. WO 2019 / 236616, etc. or any combination thereof.

[0088] III. General Discussion on Data and Information

[0089] The generated measurement data (e.g., as discussed above) is processed (e.g., in an automated manner in a controller (114), a remote system (126), etc., or any combination thereof) to estimate, derive, distinguish, or otherwise obtain one or more spatial characteristics of a beam of laser energy, one or more energy characteristics of a beam of laser energy, etc., or any combination thereof.

[0090] Examples of spatial characteristics that can be measured may include spatial energy distribution, spatial phase distribution, spatial polarization distribution, spot size, spot shape, spot orientation, spot center, spot quality (e.g., expressed by M2 parameters as known in the art), or any combination thereof. Spot shape may be measured, calculated, estimated, or otherwise determined using any known or suitable technique (e.g., any known technique for calculating circularity, roundness, etc.). For example, circularity may be determined according to the following equation.

[0091]

[0092] Here, C is the circularity of the spot illuminated by the laser energy beam, A is the area of ​​the spot, and P is the perimeter of the spot area.

[0093] Examples of energy characteristics may include spot fluence, pulse energy (i.e., when the beam of laser energy comprises one or more pulses of laser energy), average power, peak power, etc., or any combination thereof. In some embodiments, data representing one or more of the aforementioned characteristics, such as pulse energy (i.e., when the beam of laser energy comprises one or more pulses of laser energy), average power, peak power, etc., or any combination thereof, may be used to facilitate the determination of energy characteristics such as spot fluence. Data representing one or more other characteristics, such as pulse duration or pulse repetition frequency (i.e., when the beam of laser energy comprises one or more pulses of laser energy), may also be used to facilitate the determination of one or more energy characteristics. If not generated as measurement data, such data may be input to the controller (114) (e.g., via a user interface (120), a communication module (122), etc.) or otherwise accessible to the controller (114), a remote system (126), etc., or any combination thereof.

[0094] Measurement data may be generated periodically, continuously (e.g., over a period of time, e.g., while the workpiece (102) is being processed), or before or after an event occurs, or any combination thereof. Examples of events that can trigger the generation of measurement data include the start of processing of the workpiece (102), the completion of processing of one or more workpieces (102), operation of the device (100) for a predetermined amount of time, operation of the laser source (104) for a predetermined amount of time, or any combination thereof. Other examples of events that can trigger the generation of measurement data may include the reception of a command to measure one or more beam characteristics (e.g., input via a user interface (120), a remote system (126), etc., or any combination thereof).

[0095] Data representing one or more spatial or energy characteristics (generally referred to herein as “spot data”) that is estimated, derived, distinguished, or otherwise obtained from measurement data may be interpreted, manipulated, input into an algorithm, or otherwise processed to support one or more operations (e.g., in a controller (114), a remote system (126), etc., in an automated manner, or any combination thereof).

[0096] There is measurement data, spot data, or any other data (e.g., data indicating pulse duration or pulse repetition frequency, data generated or otherwise acquired when performing a test or inspection operation after the workpiece (102) has been processed, one or more other characteristics of the device (100), such as debris nozzle vacuum or air pressure and flow, vacuum pressure in the fixture, position sensor feedback associated with the second positioner (108) and / or third positioner (110), temperature and / or humidity within the process bay (generally, the process bay is a space where the workpiece (102) is arranged during processing), etc., or any combination thereof). Other data indicating temperature and / or humidity within the surrounding environment surrounding the device (100), etc., or any combination thereof may also be stored. It will be understood that data indicating temperature and / or humidity within the process bay, temperature and / or humidity within the surrounding environment, etc., may be generated by one or more known types of temperature sensors, humidity sensors, etc. These sensors are generally illustrated as reference numeral 130 in FIG. 1. Other data that may be stored includes data representing feedback signals associated with one or more positioners (e.g., a second positioner (108), a third positioner (110), etc., or any combination thereof). Other data may be derived from measurement data, spot data, or any of the aforementioned data (e.g., by processing such data in a controller (114), a remote system (126), etc., or any combination thereof), and may also be stored.Examples of such derived data include the total amount of laser energy delivered during feature formation, the pulse-averaged laser energy amount delivered during feature formation (i.e., the total amount of laser energy delivered during feature formation divided by the number of pulses delivered during feature formation), the n-pulse moving average laser energy amount (i.e., the moving average of the amount of laser energy delivered during feature formation divided by "n" pulses, where "n" can be set by the user or otherwise predetermined), etc. There are other examples of derived data indicating the presence of a positioning error, the magnitude of a positioning error, etc., or any combination thereof (as provided by a positioner such as the second positioner (108), for example), which may be derived from feedback signals associated with the positioner. All such stored data may generally be referred to as "process control data."

[0097] Process control data may also include data representing one or more measured characteristics of the workpiece (102) (e.g., before processing, during processing, or after processing, or any combination thereof). Examples of such data may include data representing measured characteristics such as the thickness of the entire workpiece (102) or one or more constituent structures of the workpiece (102), the surface quality of the workpiece (102) (e.g., characterization of any surface defects such as scratches, pits, etc.), the reflectance of the workpiece (102), the temperature of the workpiece (102), the distance from the scan lens (112) (or scan head) to the workpiece (102), or any combination thereof. These characteristics may be measured in a section of the workpiece (102) before a feature is formed in that section, while a feature is formed in that section, or after a feature is formed in that section, or any combination thereof. Examples of sensors known in the art that can be used to generate this process control data include cameras (e.g., including various lighting methods), laser displacement sensors, confocal laser sensors, interferometers, inductive coating thickness gauges, stylus profilometers, touch probes, etc., or any combination thereof. These sensors are also generally illustrated in FIG. 1 by reference numeral 130.

[0098] Generally, the test or inspection operation may be performed by an automated optical inspection (AOI) system, an automated X-ray inspection (AXI) system, an in-circuit test (ICT) system, a wafer probe system, etc. In one embodiment, the visual inspection of the workpiece (102) may be performed by one or more cameras integrated into the device (100) (i.e., the aforementioned "inspection system").

[0099] Process control data may be stored in association with auxiliary information. Generally, the storage of process control data (associated with auxiliary information) is achieved using one or more databases, which may exist locally (e.g., in the computer memory of the controller (114) or otherwise accessible from the controller (114)) or located remotely from the device (100) (e.g., in the computer memory of the remote system (126) or otherwise accessible from the remote system (126), etc. or any combination thereof.

[0100] Examples of auxiliary information that may be associated with process control data include the identity of the device (100) (e.g., in terms of serial number, model number, etc.), the identity of the workpiece (102) to be processed (or processed) by the device (100) (e.g., in terms of batch or lot number, serial number, model number, etc.), the identity (or location) of each feature to be formed (or formed) on the workpiece (102), the date and / or time on which the process control was created or otherwise acquired, etc., or any combination thereof. For example, process control data obtained from measurement data generated when a first feature is formed while processing the workpiece (102) (e.g., data representing laser energy, peak power, average power, pulse repetition rate, spot size, etc., or any combination thereof) may be associated with auxiliary information that uniquely identifies the first feature (or the location of the first feature in the workpiece (102)), and process control data obtained from measurement data generated when a second feature is formed while processing the workpiece (102) (e.g., data representing laser energy, peak power, average power, pulse repetition rate, spot size, etc., or any combination thereof) may be associated with auxiliary information that uniquely identifies the second feature (or the location of the second feature in the workpiece (102)). The locations of features to be formed on the workpiece (102) can be distinguished based on any scaling parameters that can be calculated from information provided by the user or generated by the device (100) (e.g., CAD files or other tool path files describing process trajectories, or any combination thereof) and alignment points captured by one or more cameras (e.g., camera (113)).

[0101] Auxiliary information may also include “workpiece information,” which describes one or more characteristics of the workpiece (102) when the workpiece (102) exists before, during, or after processing, or any combination thereof. Examples of workpiece information may include the material composition of one or more constituent structures of the entire workpiece (102), lot number, panel number, thickness map, etc., or any combination thereof. Auxiliary information may also include “application information” describing how the workpiece (102) is to be processed (or processed), and may describe the type(s) of features to be formed on the workpiece (102), the location of features to be formed on the workpiece (102), etc., or any combination thereof. Workpiece information and application information may be provided by any suitable method (e.g., by a user interacting with a user interface (120), a remote system (126), etc., or any combination thereof). In some embodiments, work information or application information may be encoded by machine-readable markings (one or more markings that can be captured and distinguished by a component of the device (100), such as a camera (113). In other embodiments, machine-readable markings may encode a link (e.g., a URL to a network resource containing work information or application information) that can be captured and distinguished by a component of the device (100), such as a camera (113).

[0102] Once stored, the process control data may later be interpreted, manipulated, input into an algorithm, or otherwise processed to support one or more operations (e.g., at a controller (114), at a remote system (126), etc., or any combination thereof). Exemplary embodiments of these operations are described in more detail in the sections below titled “directed inspection”.

[0103] A. Directed inspection

[0104] After the workpiece (102) is processed to form a plurality of features (e.g., blind-via holes, through-via holes, or a combination thereof) therein, any of the aforementioned process control data (e.g., in relation to auxiliary information stored in association therewith) may be processed to identify features to be inspected, because there is a relatively high probability that these features are defective. Generally, this processing (referred to herein as the “candidate feature selection” process) may be performed in a controller (114), in a remote system (126), etc., or in any combination thereof. Features identified to be inspected are referred to herein as “candidate features.”

[0105] After candidate features are identified, the third positioner (110) can be operated to move each candidate feature into the field of view of the camera (113), and the camera (113) can be operated to capture an image of each candidate feature located within the field of view. The process of operating the third positioner (110) and the camera (113) to capture images of the candidate features is referred to herein as "inspection." It will be understood that inspecting only the candidate features formed on the workpiece (102) requires much less time than inspecting all features formed on the workpiece (102). It will also be understood that inspecting only the candidate features instead of randomly sampled features formed on the workpiece will reduce the likelihood that areas of the workpiece (102) containing defective features will be missed during inspection.

[0106] i. Further discussion regarding candidate feature selection

[0107] As mentioned above, the candidate feature selection process is applied to process control data and any associated auxiliary information to identify candidate features for inspection. In some embodiments, the candidate feature selection process applies one or more analysis methods and statistical thresholds (e.g., which may be determined empirically or identified as a result of computer modeling or simulation), one or more machine learning algorithms, or any combination thereof, to any process control data to estimate or determine which of the processed features is relatively likely to be defective. It will be understood that one or more suitable analysis methods and machine learning algorithms known in the art may be implemented to facilitate the candidate feature selection process.

[0108] A process engineer skilled in a priori can develop analysis methods and set appropriate thresholds for this candidate feature selection process. However, through a combination of such process control data, the candidate feature selection process, one or more inspection systems, one or more cameras (e.g., camera (113)), etc., or any combination thereof, an automated learning feedback loop can be created using machine learning algorithms or by using manual offline statistical correlations by a skilled person.

[0109] The candidate feature selection process may generate as output a data structure (e.g., a list) containing auxiliary information (including the identity or location of each feature within the workpiece (102) or along the processing trajectory) or any process control data for each feature estimated or determined to be relatively likely to be defective. It will be understood that the output of the estimated or determined likelihood for any feature may be stored as auxiliary information associated with that feature, which may be used for future analysis, traceability purposes, or any combination thereof.

[0110] Optionally, specific aspects of the candidate feature selection process may be tuned based on input from a user (e.g., provided via a user interface (120), a remote system (126), etc., or any combination thereof). For example, the user may specify how many features (e.g., absolute or relative terms) should be included in the output data structure. In another example, the user may specify whether features satisfying some estimated or determined criteria for defects should be included in the output data structure.

[0111] a. Exemplary embodiments regarding candidate feature selection

[0112] In some embodiments, the candidate feature selection process may be applied to process control data representing laser energy delivered to at least the workpiece (102) (e.g., total amount, average amount, etc. as discussed above) (e.g., during the formation of each feature, during a specific step of forming each feature, etc., or any combination thereof). In this case, statistical thresholds that may be used to analyze the process control data (e.g., for one or more predetermined setpoints based on one or more items associated with workpiece information and / or application information) may include thresholds such as maximum positive or negative laser energy deviation. Generally, if the total amount or average amount of laser energy delivered during the formation of the feature (or delivered during a specific step of the process of forming the feature) exceeds the maximum positive laser energy deviation, the ultimately formed feature is likely to be defective because too much laser energy was used to form the feature. Features formed using too much laser energy (e.g., blind via holes, trenches, recesses, etc.) may be considered defective because the material exposed to or otherwise near the feature may be undesirably damaged (e.g., melting, ablation, cracking, etc.), or the feature itself may have an undesirable size or shape, or an undesirable taper, overhang, etc., or any combination thereof. Similarly, if the total or average amount of laser energy delivered during the formation of the feature (or delivered during a specific step of the feature-forming process) exceeds the maximum negative laser energy deflection, the ultimately formed feature is likely to be defective because too little laser energy was used to form the feature.Features formed using too little laser energy (e.g., blind via holes, through via holes, trenches, recesses, etc.) may be considered defective because sufficient material was not removed from the workpiece (102) to form the features as desired.

[0113] ii. Further discussion regarding the examination

[0114] The location of each candidate feature identified in the output of the candidate feature selection process may be used to control the operation of the third positioner (110) during inspection. In one embodiment, an offset (e.g., in the X-direction and / or Y-direction) may be applied to each location to compensate for any lateral offset between the field of view of the scan lens (112) and the camera (113) as projected onto the workpiece (102). Generally, the operation of the third positioner (110) may be controlled during inspection to cause relative movement between the workpiece (102) and the camera (113) (i.e., the field of view of the camera as projected onto the workpiece (102)) along a path or trajectory (also referred to as the “inspection trajectory”) that can be computed based on the output of the candidate feature selection process (e.g., in the controller (114), in the remote system (126), etc., or any combination thereof). In one embodiment, the inspection trajectory used to inspect features formed during the processing of the workpiece (102) corresponds to the process trajectory used to form features during the processing of the workpiece (102). In another embodiment, the inspection trajectory does not correspond to the process trajectory used to form features during the processing of the workpiece (102). In this case, the inspection trajectory may represent an optimized path or route that enables the camera (113) to capture images of each candidate feature in the processed workpiece (102).

[0115] Image data generated by the camera (113) during inspection (i.e., representing an image captured within the camera's field of view) is output to the controller (114) (e.g., as one or more image signals) and subsequently, in order to determine whether a feature is properly formed (i.e., defective), it may be interpreted, manipulated, input into an algorithm, or otherwise processed in any desired or otherwise suitable manner known in the art (e.g., by the controller (114), by the remote system (126), by a user, etc., or by any combination thereof). It will be understood that image data representing a captured image of any candidate feature may be stored as auxiliary information associated with that feature, which may be used for subsequent analysis, tracking purposes, etc., or any combination thereof.

[0116] a. Passive modalities associated with supervised testing and classification

[0117] In one embodiment, the third positioner (110) may be manually operated to move each candidate feature into the field of view of the camera (113) (e.g., through user interaction via a user interface (120), a remote system (126), etc., or any combination thereof), and the camera (113) may be operated to capture an image of each candidate feature located within the field of view (e.g., through user interaction via a user interface (120), a remote system (126), etc., or any combination thereof). The captured image may be displayed (e.g., by a monitor of the user interface (120), the remote system (126), etc., or any combination thereof), and the user may manually classify the feature associated with the displayed image as, for example, defective or non-defective (e.g., through an input device such as the user interface (120) or the remote system (126).

[0118] b. Automated modalities associated with supervised inspection and classification

[0119] In another embodiment, the operation of the third positioner (110) and the camera (113) may be performed in an automated manner (e.g., by a controller (114), a remote system (126), etc., or any combination thereof) to perform inspection and classification of each candidate feature. In this embodiment, image data generated as a result of inspection may be processed using any suitable image recognition technology to classify the inspected feature as, for example, defective or non-defective. While the third positioner (110) is operating to move the candidate feature into the field of view of the camera (113), an image may be captured after the operation of the third positioner (110) is settled and the candidate feature is stopped within the field of view of the camera (113), or at any combination thereof.

[0120] c. Semi-automated modalities associated with supervised inspection and classification

[0121] In another embodiment, the operation of the third positioner (110) and the camera (113) may be performed in a semi-automated manner to perform inspection and classification of each candidate feature. In this embodiment, the third positioner (110) is operated (e.g., by a controller (114), a remote system (126), etc., or any combination thereof) to cause the camera (113) to capture an image of each candidate feature. The captured image may then be displayed (e.g., by a monitor of a user interface (120), a remote system (126), etc., or any combination thereof), and the user may manually classify the feature associated with the displayed image as, for example, defective or non-defective (e.g., through an input device such as a user interface (120) or a remote system (126). An exemplary process for collecting manual input classifications of candidate features is discussed in more detail below with respect to FIG. 2.

[0122] In FIG. 2, a process such as process (200) may be executed to facilitate manual classification of candidate features. Referring to FIG. 2, in step (S202), an image of an inspected unclassified candidate feature is displayed to the user (e.g., through the user interface (120), through the user interface of the remote system (126), etc.). Optionally, other information associated with the candidate feature, the identity or location of the candidate feature within the workpiece (102), may also be displayed to the user (e.g., through the user interface (120), through the user interface of the remote system (126), etc.). In step (S204), the user is prompted (e.g., through the user interface (120), through the user interface of the remote system (126), etc.) to indicate whether they wish to classify the currently displayed candidate feature. If the user agrees to classify candidate features, in step (S206), the user classifies the candidate features based on the displayed image (e.g., as “defective” or “non-defective”) (e.g., through the user interface (120), through the user interface of the remote system (126), etc.). If any unclassified candidate features remain, the process described above is repeated. In step (S208), the user is prompted to indicate whether they wish to classify other unclassified candidate features (e.g., through the user interface (120), through the user interface of the remote system (126), etc.). If another unclassified candidate feature is examined, the process discussed above is repeated for the new unclassified candidate feature. If no unclassified candidate features remain in step (S208), the process is terminated.If, at step (S204), the user indicates that they do not want to classify the currently displayed candidate features (e.g., through the user interface (120), through the user interface of the remote system (126), etc.), the process proceeds to step (S208).

[0123] iii. Other modalities of supervisory testing

[0124] It will be understood that information regarding the classification of any inspected candidate feature—whether classified manually or automatically—may be stored as auxiliary information associated with that feature, and may be used for future analysis, tracking purposes, or any combination thereof.

[0125] The embodiments discussed above have so far discussed how the output of the candidate feature selection process can be used to control the operation of the device (100) (e.g., a third positioner (110), a camera (113), or a combination thereof) during inspection. However, in other embodiments, the output of the candidate feature selection process may be input to an inspection system (also referred to as a “remote inspection system”) that is not part of the device (100) (e.g., provided as discussed above). Examples of remote inspection systems capable of performing inspection of identified candidate features may include AOI, AXI systems, ICT systems, wafer probe systems, etc., or any combination thereof.

[0126] In one embodiment, the remote inspection system is an embodiment of the remote system (126), and thus the controller (114) is operated to transmit the output of the candidate feature selection process to the remote inspection system (i.e., the remote system (126)) via the network (124). However, in another embodiment, the controller (114) is operated to write the output of the candidate feature selection to be processed to any machine-readable medium (e.g., a flash drive inserted into the USB port of the communication module (122)) or to transmit the output of the candidate feature selection to any other system (e.g., the remote system (126)), wherein the output of the candidate feature selection may be written to any suitable or desired machine-readable medium (e.g., a flash drive) connected to the remote system (126). Afterward, the output of the candidate feature selection stored by the machine-readable medium may then be input to the remote inspection system in any suitable or desired manner.

[0127] XIII. Conclusion

[0128] The foregoing is illustrative of embodiments and examples of the present invention and should not be construed as limiting. Although some specific embodiments and examples have been described with reference to the drawings, those skilled in the art will readily understand that many modifications to the disclosed embodiments and examples, as well as to other embodiments, are possible without substantially departing from the new teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the claims. For example, those skilled in the art will recognize that any sentence, paragraph, example, or subject of an embodiment may be combined with the subject of some or all of other sentences, paragraphs, examples, or embodiments, except where such combinations are mutually exclusive. Accordingly, the scope of the present invention should be determined by the following claims, together with equivalents of the claims to be included therein.

Claims

Claim 1 A laser processing device for forming features in a workpiece, the device comprising: a laser source operating to generate a beam of laser energy; an arrayed scan lens operating to focus the beam of laser energy so that the focused beam of laser energy can be delivered to the workpiece; at least one beam positioner arranged between the laser source and the scan lens, wherein the at least one beam positioner operates to scan the focused beam of laser energy for the workpiece within a scanning range projected onto the workpiece by the scan lens; a camera having a field of view and operating to capture an image of an object within the field of view; and at least one stage operating to provide relative movement between at least one selected from a group consisting of the scan lens and the camera and the workpiece. and at least one sensor operating to generate process control data—the process control data represents at least one selected from a group consisting of: a) at least one characteristic of the device before, during, or after the workpiece is processed to form a set of features; b) at least one characteristic of the workpiece before, during, or after the workpiece is processed to form a set of features; and c) at least one characteristic of the surrounding environment where the device is located before, during, or after the workpiece is processed to form a set of features.A laser processing device comprising: at least one stage; a camera; and a controller communically coupled to one or more databases in which process control data is stored in association with auxiliary information, wherein the auxiliary information indicates the location of each feature to be formed on the workpiece, and the controller operates to execute a candidate feature selection process or to facilitate the execution of the candidate feature selection process, thereby: the process control data is processed to estimate whether any of the features formed on the workpiece are defective; and the location of any feature presumed to be defective is identified, and the controller processes an image acquired by the camera at the location of the feature presumed to be defective to determine whether the feature is defective. Claim 2 A laser processing device according to claim 1, wherein the controller operates to execute at least a part of the candidate feature selection process. Claim 3 A laser processing device according to claim 1, further comprising a communication module that is communicably coupled to the controller and operates to transmit data. Claim 4 A laser processing device according to paragraph 3, wherein the controller operates to transmit the output of the candidate feature selection process to a remote system through the communication module. Claim 5 A laser processing device according to paragraph 4, wherein the remote system is a remote inspection system and the output of the candidate feature selection process is in a format readable by the remote inspection system. Claim 6 A laser processing device according to paragraph 3, wherein the controller operates to facilitate the execution of the candidate feature selection process by transmitting at least a portion of the process control data to a remote system through the communication module. Claim 7 delete Claim 8 A laser processing device according to claim 4, wherein the communication module operates to receive data, and the controller operates to receive at least a portion of the output of the candidate feature selection process from the remote system through the communication module. Claim 9 A laser processing device according to claim 1, further comprising at least one of the above one or more databases. Claim 10 A laser processing device according to paragraph 3, wherein the controller operates to transmit at least a portion of the process control data to at least one of the one or more databases through the communication module. Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 A laser processing device according to claim 1, further comprising an inspection support arranged to support the camera with respect to the workpiece, wherein the camera is coupled to the inspection support. Claim 19 A laser processing device according to claim 18, further comprising a stage coupled to the inspection support and operated to move the inspection support relative to the workpiece. Claim 20 A laser processing device according to claim 18, further comprising a stage coupled between the inspection support and the camera, wherein the stage operates to move the camera relative to the inspection support. Claim 21 A laser processing device according to claim 1, wherein the controller additionally operates to control the operation of at least one stage and camera to perform inspection operations at each identified location. Claim 22 A laser processing device according to claim 1, wherein the controller further operates to control the operation of the at least one stage and the camera based on user input received from a user interface to perform inspection operations of each identified position. Claim 23 A laser processing device according to paragraph 3, wherein the controller further operates to control the operation of the at least one stage and the camera based on data received from a remote system through the communication module to perform inspection operations of each identified location. Claim 24 A laser processing device according to claim 1, wherein the at least one sensor comprises at least one selected from the group consisting of a laser power meter, a beam characterization tool, a temperature sensor, a humidity sensor, a camera, a laser displacement sensor, a confocal laser sensor, interferometers, an inductive coating thickness gauge, a stylus profilometer, and a touch probe. Claim 25 delete Claim 26 delete

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