Abstract: A method for laser drilling and laser cutting of semiconductor material or glass in pulsed regime permits, for a given laser power, a rate of material cutting which is substantially higher than the rate obtained using conventional laser cutting. The hole or cut produced by the laser-induced removal of material has a reproducible shape, the drilling or cutting does not produce material debris or spatter deposition around the crater or cut, and the cracking of the crater or cut walls is prevented. The method includes utilization of a unique physical model representing all main physical processes taking place during laser-assisted material deposition, a corresponding mathematical model consisting of equations describing the relevant physical processes, and a computer code used for numerical calculations of the parameters of interest according to the mathematical model.

Abstract: Digital control of frequency and/or amplitude modulation techniques of an intracavity and/or extracavity AOM (60) facilitate substantially full extinction of a laser beam (90) to prevent unwanted laser energy from impinging a workpiece (80); facilitate laser pulse amplitude stability through closed-loop control of pulse-to-pulse laser energy; facilitate beam-positioning control including, but not limited to, closed-loop control for applications such as alignment error correction, beam walk rectification, or tertiary positioning; and facilitate employment of more than one transducer on an AOM (60) to perform any of the above-listed applications.

Abstract: Digital control of frequency and/or amplitude modulation techniques of an intracavity and/or extracavity AOM (60) facilitate substantially full extinction of a laser beam (90) to prevent unwanted laser energy from impinging a workpiece (80); facilitate laser pulse amplitude stability through closed-loop control of pulse-to-pulse laser energy; facilitate beam-positioning control including, but not limited to, closed-loop control for applications such as alignment error correction, beam walk rectification, or tertiary positioning; and facilitate employment of more than one transducer on an AOM (60) to perform any of the above-listed applications.

Abstract: Digital control of frequency and/or amplitude modulation techniques of an intracavity and/or extracavity AOM (60) facilitate substantially full extinction of a laser beam (90) to prevent unwanted laser energy from impinging a workpiece (80); facilitate laser pulse amplitude stability through closed-loop control of pulse-to-pulse laser energy; facilitate beam-positioning control including, but not limited to, closed-loop control for applications such as alignment error correction, beam walk rectification, or tertiary positioning; and facilitate employment of more than one transducer on an AOM (60) to perform any of the above-listed applications.

Abstract: Digital control of frequency and/or amplitude modulation techniques of an intracavity and/or extracavity AOM (60) facilitate substantially full extinction of a laser beam (90) to prevent unwanted laser energy from impinging a workpiece (80); facilitate laser pulse amplitude stability through closed-loop control of pulse-to-pulse laser energy; facilitate beam-positioning control including, but not limited to, closed-loop control for applications such as alignment error correction, beam walk rectification, or tertiary positioning; and facilitate employment of more than one transducer on an AOM (60) to perform any of the above-listed applications.

Abstract: A fully integrated automated laser weld process control system (LWPCS) and method of controlling the fabrication of structural parts, particularly for shipbuilding and other industries. The LWPCS defines joint and weld quality attributes as process control variables and integrates these weld quality variables, along with the more traditional process parameters such as laser power, wire feed, GMAW voltage and active seam tracking, into a closed-loop monitoring and control system. The LWPCS includes a central processor and a plurality of subsystems that control laser beam positioning, vision-based monitoring and image processing, active weld-quality monitoring and inspection, adaptive beam delivery, and seam tracking. Cross-communication between subsystems is managed by the central processor. In addition to process control, the system extracts weld quality attributes during the weld process and provides immediate documentation of the weld quality.

Abstract: A method for laser shock peening an article including laser shock peening a first area with at least one high fluence laser beam and laser shock peening a border area between the first area and a non-laser shock peened area of the article with at least one first low fluence laser beam. The border area may be laser shock peened with a second low fluence laser beam or more low fluence laser beams wherein the second low fluence laser beam and others have a lower fluence than the first low fluence laser beam. The border area may be laser shock peened with progressively lower fluence laser beams starting with the one first fluence laser beam wherein the progressively lower fluence laser beams are in order of greatest fluence to least fluence in a direction outwardly from the first area through the border area to the non-laser shock peened area.

Abstract: An object of the present invention is obtaining a semiconductor film with uniform characteristics by improving irradiation variations of the semiconductor film. The irradiation variations are generated due to scanning while irradiating with a linear laser beam of the pulse emission. At a laser crystallization step of irradiating a semiconductor film with a laser light, a continuous light emission excimer laser emission device is used as a laser light source. For example, in a method of fabricating an active matrix type liquid crystal display device, a continuous light emission excimer laser beam is irradiated to a semiconductor film, which is processed to be a linear shape, while scanning in a vertical direction to the linear direction. Therefore, more uniform crystallization can be performed because irradiation marks can be avoided by a conventional pulse laser.

Abstract: A method for providing a pre-welding heat treatment to a workpiece surface is described wherein the method includes the steps of: generating through a laser generator a laser beam characterized by a power and focal point; positioning the laser generator such that the focal point of the laser beam is above the workpiece surface so as to generate a defocused laser beam; directing the defocused laser beam toward the workpiece surface so as to project a laser beam spot on the workpiece surface; scanning the laser beam spot over the workpiece surface thereby heating the workpiece surface so as to provide a pre-welding heat treatment; repositioning the laser generator such that the focal point of the laser beam is changed; and laser welding the workpiece with substantially the same power as in the generating step. The method is further adapted for use with a hand held Nd:YAG laser torch, and the workpiece may be a superalloy gas turbine engine component.

Abstract: During laser beam welding a so-called end crater forms at the end of the weld seam. The end crater is formed by the volume shrinkage of the solidifying melt after the laser beam reaches the seam end and is switched off or repositioned. The end crater acts as a geometric notch and decreases the mechanical characteristics, in particular the operational stability, of the weld seam so that holes or tears in the area of the end crater can occur. The task of the present invention is thus comprised of providing a process for reducing end crater formation. The task is solved in that towards the seam end the focus of the laser beam is distanced from the surface to be welded and/or a transverse movement of the beam occurs.

Abstract: A laser cleaving apparatus for use in terminating optical fiber cable ends has a laser beam source, the output of which is directed through a beam distorting member, which produces a beam having a chisel shape with a substantially flat side normal to the axis of a connector fiber containing ferrule and focuses it onto the fiber at a point adjacent the ferrule end face with the flat side also adjacent the end face. A single step polishing stage polishes the cleaved fiber end face to make it flat and flush with the ferrule end face.

Abstract: A printed circuit board has a circuit trace on it and a solder mask over the circuit trace. The solder mask is removed from the printed circuit board using an ultra violet laser, to expose the circuit trace without damaging the circuit trace. A failure analysis is performed on the circuit trace of the printed circuit board.

Abstract: A laser-working method is disclosed, which includes the steps of splitting a single pulse laser beam having a time width of not more than 500 picoseconds into plural pulse laser beams; subjecting said plural pulse laser beams to time delaying, and adjusting a working surface-irradiating shape, an intensity distribution and a working surface-irradiating position of each of the plural pulse laser beams; working a target object to be irradiated, while the respective working surface-irradiating shapes of said plural laser beams are partially or entirely spatially overlapped with each other or one another; and setting to a time interval of from a pulse width to 1 nanosecond a time period during which each of the pulse laser beams is irradiated.

Abstract: A fine structure manufacturing method is provided. The method comprises providing a lyophilic film on a treated surface of a substrate on which a pattern having a desired form is to be formed, providing a liquid-repellent film on an upper surface of the lyophilic film, the liquid-repellent film having liquid repellency relative to a liquid material used for forming the pattern, and eliminating a part of the liquid-repellent film located on an area where the pattern is to be formed.

Abstract: When a working condition is set, if an operator sets the working condition, a control device (1) obtains an expected load factor of a laser oscillator (2) based on the set working condition, and displays the load factor as a working condition check bar (8) on a display device (3). The operator adjusts the working condition so that a load factor of the laser oscillator (2) stays within a predetermined range while watching the working condition check bar (8) and determines an appropriate working condition. Therefore, it is possible to prevent excessive load from being applied to the laser oscillator (2) at the time of actual working.

Abstract: Digital control of frequency and/or amplitude modulation techniques of an intracavity and/or extracavity AOM (60) facilitate substantially full extinction of a laser beam (90) to prevent unwanted laser energy from impinging a workpiece (80); facilitate laser pulse amplitude stability through closed-loop control of pulse-to-pulse laser energy; facilitate beam-positioning control including, but not limited to, closed-loop control for applications such as alignment error correction, beam walk rectification, or tertiary positioning; and facilitate employment of more than one transducer on an AOM (60) to perform any of the above-listed applications.

Abstract: A first electrode part in a rod shape is placed on an upper side, and a second electrode part in a rod shape having a higher melting point than that of the first electrode part is placed on a lower side, so that ends of the first and second electrode parts are brought into contact. Contact ends or vicinities thereof are irradiated with a laser beam, so that the electrode parts are welded. Here, a region irradiated with the laser beam is in a long narrow shape having a minor axis directed in a vertical direction and a major axis directed in a horizontal direction. This makes it possible to manufacture an electrode with a consistent high quality with a high yield.

Abstract: Digital control of frequency and/or amplitude modulation techniques of an intracavity and/or extracavity AOM (60) facilitate substantially full extinction of a laser beam (90) to prevent unwanted laser energy from impinging a workpiece (80); facilitate laser pulse amplitude stability through closed-loop control of pulse-to-pulse laser energy; facilitate beam-positioning control including, but not limited to, closed-loop control for applications such as alignment error correction, beam walk rectification, or tertiary positioning; and facilitate employment of more than one transducer on an AOM (60) to perform any of the above-listed applications.

Abstract: A laser machining apparatus capable of changing a laser output condition at a desired machining position and time without regard to interpolation period (ITP). When the remaining motion command amount in the former of successive blocks, used for the interpolation period Q0 between these blocks, is less than a motion command amount corresponding to a command speed in the ITP, such deficiency is supplemented by a motion command for the latter block, thus maintaining a moving speed unchanged. The laser output condition is changed between the blocks. In an ITP Q?1, a CNC sets the time period and the laser output condition in laser output control signal generating unit which changes the laser output condition when the time period has elapsed from the start of the ITP Q0, making it possible to change the laser output condition at an arbitrary time without being limited by the ITP.

Abstract: A method and devices for generating laser pulse trains for delivery to a target including the use of a single laser generator which produces a plurality of pulse groupings of two or more individual laser pulses within each laser pulse train, generated at selected time intervals. The time intervals between the individual pulses within each of the pulse groupings along with the intervals between pulse groupings themselves are selected and controlled by a controller in reference to several variables including the emission and energy storage lifetimes of the lasing medium, the thermal diffusion time constant of the target, the time required to cool the target after the application of laser pulses to its ambient temperature, and the dissipation time of acoustic waves generated by the pulses.

Abstract: A machining apparatus includes a light source (1) for generating light energy, an optical system (2, 3) for guiding the generated light energy to a joint position of a workpiece, a table (5a) on which the workpiece is mounted, and a heating device (5b) provided at the table for heating the workpiece. The machining apparatus, a machining method and production equipment using the machining apparatus allow the workpiece to be locally heated fast, which is applicable to soldering or the like.

Abstract: A control console that is used in conjunction with a hand-held laser welding wand is adapted to couple to an electrically controllable filler media supply source, and to an electrically controllable laser source. The control console includes a control switch that is electrically coupled to the filler media supply source and the laser source and is configured to such that an operator can independently and simultaneously control the filler media supply source to either supply or not supply filler media, and the laser source to either emit or not emit laser light therefrom. The control switch is preferably further configured to control the optical power level of the laser source.

Abstract: A DOE homogenizer including a plurality of parallel lasers emitting Gaussian beams of a diameter d along beam lines extending in a z-direction and aligning at a pitch p in an x-direction, and off-axis DOEs diffracting the Gaussian laser beams at inclining diffraction angles, making quasi-uniform density q×w (q>w) stripe-sectioned beams on an image plane I (xy-plane) which is distanced by a focal length f from the DOEs and aligning at the pitch p on an x-direction extending base line K vertical to the beam lines in an order of larger inclining diffraction angles outward and smaller inclining diffraction angles inward on extensions of the beam lines of the lasers, the DOEs diffracting the laser Gaussian beams into the quasi-uniform density stripe-sectioned beams, superposing the diffracted beams partially at edges and making a unified x-direction extending quasi-uniform beam on the image plane I.

Abstract: An object of the present invention is obtaining a semiconductor film with uniform characteristics by improving irradiation variations of the semiconductor film. The irradiation variations are generated due to scanning while irradiating with a linear laser beam of the pulse emission. At a laser crystallization step of irradiating a semiconductor film with a laser light, a continuous light emission excimer laser emission device is used as a laser light source. For example, in a method of fabricating an active matrix type liquid crystal display device, a continuous light emission excimer laser beam is irradiated to a semiconductor film, which is processed to be a linear shape, while scanning in a vertical direction to the linear direction. Therefore, more uniform crystallization can be performed because irradiation marks can be avoided by a conventional pulse laser.

Abstract: Preferred embodiments of a system and methods to deliver different magnitudes of laser power density to a work piece while maintaining a constant focusing spot size are described. In particular, the system includes a laser, an optical focusing assembly and an overlay. The overlay receives a laser beam having a perimeter at a first magnitude of power and transmits the laser beam to the optical focusing assembly at about the same perimeter and at a magnitude lower than the first magnitude. In a preferred embodiment, the overlay can include an optically neutral blocking lens or a neutral density filter. A method of laser machining an orifice at a suitable average power density sufficient to machine the orifice with reduced heat affected zone, spatters, soots or recasts is described. A method of providing a focusing spot size of a generally constant effective area by a laser machining system is also described.

Abstract: A method for manufacturing valve seats using a laser cladding process is provided that includes forming a casting material on which the valve seats are to be formed; fabricating a valve seat target position on which laser cladding will be performed, the valve seat target position being provided at a location on the casting material where a valve seat is to be formed; removing an oxidation film formed on the valve seat target position; injecting a metal powder mixture on the valve seat target position, the metal powder mixture being realized through a mixture of two or more metal powders at a predetermined ratio by weight %; and irradiating a laser beam on the metal powder mixture to clad the metal powder mixture on the valve seat target position to thereby form the valve seat.

Abstract: A controlled, switched laser system for vaporizing a target structure on a substrate includes a diode-pumped, solid-state laser for producing a laser output, a controllable switch for controlling the on/off state and power level of the laser, and a wavelength shifter. The wavelength shifter shifts the wavelength of the laser output from a conventional wavelength to a wavelength beyond the absorption edge of the substrate but shorter than 1.2 ?m in order to obtain a decrease in absorption of the laser output by the substrate due to the shift in the wavelength of the laser output. The wavelength shifter is removably insertable into the switched laser system so as to enable the switched laser system to operate at the conventional wavelength and at the wavelength beyond the absorption edge of the substrate. Heating of the substrate and hence damage to the substrate is limited due to the wavelength being beyond the absorption edge of the substrate.

Abstract: There are provided a method of manufacturing a glass substrate for information recording media that allows the inner and outer peripheral edge surfaces of the glass substrate for information recording media to be smoothed easily and inexpensively, a glass substrate for information recording media manufactured using this method, and an information recording medium using this glass substrate. A donut-shaped glass disk for information recording media having an outer peripheral edge surface and an inner peripheral edge surface is prepared. At least one of the outer peripheral edge surface and the inner peripheral edge surface of the glass disk is smoothed by melt-heating to a temperature at or above the softening point of the glass by irradiating with at least one laser beam.

Abstract: A method of controlling a robot (32) includes the steps of selecting an initial configuration from at least one of a first, second, and third sets to position a TCP at a starting point (44) along a path (33) and selecting a final configuration different than the initial configuration to position the TCP at an ending point (46). Next, the TCP moves from the starting point (44) while maintaining the initial configuration, approaches the singularity between a first point (48) and a second point (50), and selects one of the axes in response to reaching the first point (48). The angle for the selected axis is interpolated from the first point (48) to the second point (50). After the interpolation, the angles about the remaining axes are determined and positions the arms in the final configuration when the TCP reaches the second point (50) and moves to the ending point (46) while maintaining the final configuration.

Abstract: Glazing panels such as vehicle glazing panels bonded to a supporting frame are released by firstly arranging light energy delivery means adjacent the panel and subsequently transmitting light energy from the delivery means through the panel thereby to effect release of the panel from the frame. The light may be pulsed according to a predetermined regime and may be delivered by a discharge lamp having rapidly attenuating intensity. The mechanism of panel release may be by thermal degradation of the bonding material, cleavage of material at a surface of, or within the body of the panel, or a combination of such mechanisms.

Abstract: A pulsed laser system includes a laser pump, a laser rod, a reflector interposed between the laser pump and the laser rod, through which energy from the laser pump enters the laser rod, an output reflector through which energy is emitted from the laser rod, a switch interposed between the laser rod and the output reflector, and a control device. The switch, when closed, causes energy to be stored in the laser rod and, when opened, allows energy to be emitted from the laser rod during an emission period. The control device allows a primary laser pulse emitted from the laser rod during the emission period to impinge on a workpiece and blocks from the workpiece secondary laser emission occurring during the emission period after emission of the primary pulse. The pulsed laser system is operated over a range of repetition rates, so as to cause laser energy to be emitted during a plurality of emission periods at each repetition rate.

Abstract: Laser system and method for material processing with ultra fast lasers are provided. One aspect of the invention features the method which removes at least a portion of a target structure such as a memory link while avoiding undesirable damage to adjacent non-target structures. The method includes applying a single ultra short laser pulse to the target structure to remove the target structure with the single pulse.

Abstract: The present invention provides a method and apparatus for marking vehicles using a laser. In order to allow any part of the vehicle to be marked using a simple, strong laser beam delivery conduit, the laser is mounted on a structure 101 which extends over a vehicle station 102. The structure defines at least three laser mounting positions and preferably four laser mounting positions A, B, C, D, spaced apart from one another in two dimensions for mounting at least one laser apparatus 107. The laser apparatus 107 comprises a laser emitter 108 for producing a laser beam adapted to mark a part of the vehicle and laser beam delivery means 110 for delivering a laser beam from the laser emitter 108 to a selectable point of the vehicle station 102. The laser apparatus 107 is movable between at least two and preferably all four of the laser mounting positions A, B, C, and D.

Abstract: A method for laser shock peening an article including laser shock peening a first area with at least one high fluence laser beam and laser shock peening a border area between the first area and a non-laser shock peened area of the article with at least one first low fluence laser beam. The border area may be laser shock peened with a second low fluence laser beam or more low fluence laser beams wherein the second low fluence laser beam and others have a lower fluence than the first low fluence laser beam. The border area may be laser shock peened with progressively lower fluence laser beams starting with the one first fluence laser beam wherein the progressively lower fluence laser beams are in order of greatest fluence to least fluence in a direction outwardly from the first area through the border area to the non-laser shock peened area.

Abstract: A glass cutting apparatus includes a positioning unit that positions a laser beam along a virtual line on a glass to be cut. A laser beam unit irradiates a laser beam onto the glass along the virtual line. The virtual line is divided into at least two portions and at least one of the two portions is divided into a plurality of sub-portions. The energy of the laser beam is maintained constant in each of the plurality of sub-portions. A related glass cutting method is also disclosed.

Abstract: A method for simulation of laser free form fabrication of parts and laser cladding with metal powder or wire includes absorption of laser beam at the surface exposed to metal powder particle jet, enthalpy influx into the part surface due to powder injection, 3D transient conductive heat transfer in the part, material loss due to evaporation, 3D melt pool surface shape determined by surface tension and gravity, 3D shape of the melt pool bottom, interaction of laser beam with the metal powder jet (heating of powder particles and attenuation of laser beam in powder cloud), and shape of part build up due to addition of metal material.

Abstract: Formation of fractal garments using a laser to scribe a total pattern onto jean parts. The pattern is formed into a 60 by 60 image, that is formed to form all parts of the denim design.

Abstract: A quasi-CW diode- or lamp-pumped, A-O Q-switched solid-state UV laser system (10) synchronizes timing of the quasi-CW pumping with movement of the positioning system (36) to reduce pumping while the positioning system (36) is moving from one target area (31) to the next target area (31) to form multiple vias in a substrate at a high throughput. Thus, the available UV power for via formation is higher even though the average pumping power to the laser medium (16), and thermal loading of the laser pumping diodes (14), remains the same as that currently available through conventional CW pumping with conventionally available laser pumping diodes (14). The quasi-CW pumping current profile can be further modified to realize a preferred UV pulse amplitude profile.

Abstract: During laser beam welding a so-called end crater forms at the end of the weld seam. The end crater is formed by the volume shrinkage of the solidifying melt after the laser beam reaches the seam end and is switched off or repositioned. The end crater acts as a geometric notch and decreases the mechanical characteristics, in particular the operational stability, of the weld seam so that holes or tears in the area of the end crater can occur. The task of the present invention is thus comprised of providing a process for reducing end crater formation. The task is solved in that towards the seam end the focus of the laser beam is distanced from the surface to be welded and/or a transverse movement of the beam occurs.

Abstract: A laser printing apparatus is formed by a laser oscillator 10, galvano mirrors 42, 44 for scanning the laser light emitted from the laser oscillator 10, and an f&thgr; lens 40 for focusing the laser light emitted from the laser oscillator 10 on MCCs 32, 34 serving as the member to be printed. The laser oscillator 10 is an YLF laser oscillator which emits the laser light of the third harmonics in the ultraviolet range. The laser printing is performed on the MCCs 32, 34 serving as the member to be printed by using the laser light emitted from the laser oscillator 10.

Abstract: The laser beam dump is positioned in a housing. An absorbing glass plate means is operatively connected to the housing. A heat sync means for extracting heat from the absorbing glass plate means is operatively connected to the housing and operatively connected to the absorbing glass plate means.

Abstract: A quasi-CW diode-pumped, A-O Q-switched solid-state harmonic laser system (10) synchronizes timing of the quasi-CW pumping with movement of the positioning system (36) to reduce pumping while the positioning system (36) is moving from one target area (31) to the next target area (31) to form multiple vias in a substrate at a high throughput. Thus, the available UV power for via formation is higher even though the loading to the laser pumping diodes (14) remains the same as that currently available through conventional CW pumping with conventionally available laser pumping diodes (14). The quasi-CW-pumping current profile can be further modified to realize a preferred UV pulse amplitude profile.

Abstract: Glazing panels such as vehicle windscreens bonded to a supporting frame are released by firstly arranging light energy delivery means adjacent the panel and subsequently transmitting light energy from the delivery means through the panel thereby to effect release of the panel from the frame. The light may be pulsed according to a predetermined regime and may be delivered by a discharge lamp having rapidly attenuating intensity, or quasi continuous wave pulsed laser. The mechanism of panel release may be by thermal degradation of the bonding material, cleavage of material at a surface of, or within the body of the panel, or a combination of such mechanisms.

Abstract: A close proximity pulsed laser catalyst deposition system comprising a first medium containing layer of a catalyst to be deposited, a second medium disposed across a gap from and facing the layer of catalyst to be deposited, the gap being at ambient atmospheric pressure, and a pulsed laser for applying an energy beam pulse above the ablative energy threshold of the catalyst to create a vaporized plume of the catalyst and direct the vaporized plume across the gap at ambient atmospheric pressure to deposit a porous, finely divided coating of increased surface area of the catalyst on the second medium.

Abstract: A laser-based method of removing a target link structure of a circuit fabricated on a substrate includes generating a pulsed laser output at a pre-determined wavelength less than an absorption edge of the substrate. The laser output includes at least one pulse having a pulse duration in the range of about 10 picoseconds to less than 1 nanosecond, the pulse duration being within a thermal laser processing range. The method also includes delivering and focusing the laser output onto the target link structure. The focused laser output has sufficient power density at a location within the target structure to reduce the reflectivity of the target structure and efficiently couple the focused laser output into the target structure to remove the link without damaging the substrate.

Abstract: A laser working method, for conducting laser ablation working on a workpiece by irradiating the workpiece with a laser beam, includes the following steps. In working by projecting a mask pattern with the laser beam, a laser beam of plural pulses having a very high energy density in space and time, emitted from a laser oscillator that can oscillate with a pulse radiation time of 1 picosecond or less, is employed. Scanning illumination is conducted by relative movement of a source of the laser beam and the mask pattern. The relative movement between the source of the laser beam and the mask pattern may be conducted by a reciprocating movement in a direction perpendicular to an optical axis of the laser beam, asynchronously with laser oscillation, and a form of the mask pattern may be formed stepwise and in succession on the workpiece.

Abstract: A ceramic green sheet is irradiated with laser beam of high-peak short-pulse type to form a hole in the sheet. In the laser beam, the minimum oscillation output more than 60% of the maximum oscillation output. This prevents material of the ceramic green sheet from melting partially and remaining around the hole. Therefore, a multi-layer assembly of the ceramic green sheets built by joining the sheets in layers and baking the joined sheets hardly has a structural defect around a via-electrode provided in the hole.

Abstract: A system is disclosed for monitoring and controlling laser cladding process by powder injection in real-time. The invention combines laser cladding technique along with automated direct feedback control to achieve a good quality clad in terms of dimensional and metallurgical characteristics. The system uses optical CCD-based detectors as the feedback system. The optical CCD-based detectors along with a pattern recognition algorithm is used to determine the clad characteristics in real-time. These characteristics are clad's dimensions, solidification rate, and roughness that are fed into a closed loop control system to adjust the laser power and table velocity to produce desired clad quality.

Abstract: A laser machining apparatus capable of changing a laser output condition at a desired machining position and time without regard to an interpolation period. When the remaining motion command amount Pa in the former of successive blocks, used for the interpolation period Q0 between these blocks, is less than a motion command amount corresponding to a command speed in the interpolation period ITP, such deficiency Pb is supplemented by a motion command for the latter block, thus maintaining a moving speed unchanged. The laser output condition is changed between the blocks. A time period t1=ITP×Pa/(Pa+Pb) from when the interpolation period Q0 between the blocks starts to when a change from the former block to the latter is completed is determined.

Abstract: A laser process in which stripe formation due to laser annealing is prevented and uniform laser annealing is made over the whole surface of a substrate. A laser beam having an energy distribution with an edge which has a nearly vertical shape l used, and when scanning of the laser beam is carried out, the scanning is carried out while the edge having the nearly vertical shape is made the front of the scanning.