Keiji Nomaru

Bio: Keiji Nomaru is an academic researcher. The author has contributed to research in topics: Laser & Wafer. The author has an hindex of 10, co-authored 52 publications receiving 485 citations.

Laser beam processing machine

Abstract: A laser beam processing machine comprising a path distribution means for distributing a pulse laser beam oscillated by pulse laser beam oscillation means to a first path and a second path alternately, and one laser beam that passes through one of the paths and is converged by one condensing lens and the other laser beam that passes through the other path and is converged by the condensing lens are applied at different focusing points which have been displaced from each other in the direction of the optical axis, alternately with a time lag between them.

Measuring device for workpiece held on chuck table

Abstract: A measuring device for measuring the height of a workpiece held on a chuck table provided in a processing machine. The measuring device includes a white light source for emitting white light, an acousto-optic deflecting unit for separating the white light emitted from the white light source to produce a flux of diffracted light and for swinging the flux of the diffracted light over a predetermined angular range by applying a voltage, a pinhole mask for passing light having a part of the wavelengths of the diffracted light produced by the acousto-optic deflecting unit, and a chromatic aberration lens for focusing the light passed through the pinhole mask and for applying the focused light to the workpiece held on the chuck table.

Optical device for laser processing, laser processing device and laser processing method

Abstract: PROBLEM TO BE SOLVED: To efficiently form a modified layer or a laser processed groove with a depth required for dividing a workpiece with fewer number of times of irradiation of laser beam while reducing processing time. SOLUTION: An optical device for laser processing includes a light source for emitting light and a condenser for condensing light toward the workpiece 1 being an object for processing and processes the workpiece 1. Light is made to be multiwavelength coherent light 113. The condenser irradiates the multiwavelength coherent light 113 to form condensing points at different positions per multiwavelength along the optical length, so that a plurality of the condensing points are made to be present per wavelength contained in the multiwavelength coherent light 113 in a range L inside the workpiece 1 on the optical axis. A long modified layer is formed over the range L in a depth direction inside the workpiece 1 by irradiating pulse laser once. COPYRIGHT: (C)2010,JPO&INPIT

Height position detector for work held on chuck table

Abstract: A height position detector for detecting the height position of an upper surface of a work held on a chuck table, including: an annular spot forming part by which the spot shape of a laser beam oscillated by a laser beam oscillator is formed into an annular shape; a first beam splitter by which the laser beam with the spot shape formed into the annular shape is guided into a first path; a light condenser by which the laser beam guided into the first path is condensed to irradiate the work therewith; a second beam splitter for splitting the reflected light reflected by the work; a first light receiving element for receiving the reflected light transmitted through the second beam splitter; a second light receiving element for receiving the reflected light reflected by the second beam splitter; a light reception region restricting part for restricting the light reception region for the reflected light received by the second light receiving element; and a controller for determining the height position of the upper surface of the work on the basis of the ratio between the quantity of light received by the first light receiving element and the quantity of light received by the second light receiving element.

Measuring apparatus for work held by chuck table, and laser beam machining apparatus

Abstract: An apparatus for measuring the height of a work held by a chuck table provided in a machining apparatus, including: a white light source for emitting a white beam of light; a chromatic aberration lens for condensing the white beam emitted from the white light source; a beam splitter which is disposed between the white light source and the chromatic aberration lens and by which a reflected beam of the white beam irradiating the work therewith is split; a first condenser lens for condensing the reflected beam split by the beam splitter; a diffraction grating by which the reflected beam condensed by the first condenser lens is converted into a diffracted beam; a second condenser lens for condensing the diffracted beam diffracted by the diffraction grating; and a wavelength detecting unit for detecting the wavelength of the diffracted beam condensed by the second condenser lens.

Apparatuses, systems and methods for three-dimensional printing

Abstract: The present disclosure provides three-dimensional (3D) objects, 3D printing processes, as well as methods, apparatuses and systems for the production of a 3D object. Methods, apparatuses and systems of the present disclosure may reduce or eliminate the need for auxiliary supports. The present disclosure provides three dimensional (3D) objects printed utilizing the printing processes, methods, apparatuses and systems described herein.

Transparent material processing with an ultrashort pulse laser

Abstract: Methods for ultrashort pulse laser processing of optically transparent materials. A method for scribing transparent materials uses ultrashort laser pulses to create multiple scribe features with a single pass of the laser beam across the material, with at least one of the scribe features being formed below the surface of the material. This enables clean breaking of transparent materials at a higher speed than conventional techniques. Slightly modifying the ultrashort pulse laser processing conditions produces sub-surface marks. When properly arranged, these marks are clearly visible with side-illumination and not clearly visible without side-illumination. In addition, a method for welding transparent materials uses ultrashort laser pulses to create a bond through localized heating. The ultrashort pulse duration causes nonlinear absorption of the laser radiation, and the high repetition rate of the laser causes pulse-to-pulse accumulation of heat within the materials. The laser is focused near the interface of the materials, generating a high energy fluence at the region to be welded. This minimizes damage to the rest of the material and enables fine weld lines.

Accurate three-dimensional printing

Abstract: The present disclosure provides three-dimensional (3D) printing methods, apparatuses, and systems using, inter alia, a controller that regulates formation of at least one 3D object (e.g., in real time during the 3D printing); and a non-transitory computer-readable medium facilitating the same. For example, a controller that regulates a deformation of at least a portion of the 3D object. The control may be in situ control. The control may be real-time control during the 3D printing process. For example, the control may be during a physical-attribute pulse. The present disclosure provides various methods, apparatuses, systems and software for estimating the fundamental length scale of a melt pool, and for various tools that increase the accuracy of the 3D printing.

Laser processing apparatus

Abstract: A laser processing apparatus comprising a chuck table, laser beam irradiation means for irradiating a workpiece held on the chuck table with a laser beam, and processing feed means for processing-feeding the chuck table and the laser beam irradiation means relative to each other. The laser beam irradiation means includes first laser beam irradiation means for throwing a first pulsed laser beam having a wavelength in the intermediate-infrared radiation region, and second laser beam irradiation means for throwing a second pulsed laser beam having a wavelength in the ultraviolet radiation region. The first laser beam irradiation means and the second laser beam irradiation means are set such that at least a part, in the processing feed direction, of the focus spot of the second pulsed laser beam overlaps the focus spot of the first pulsed laser beam.

Skillful Three-Dimensional Printing

Abstract: The present disclosure various apparatuses, and systems for 3D printing. The present disclosure provides three-dimensional (3D) printing methods, apparatuses, software and systems for a step and repeat energy irradiation process; controlling material characteristics and/or deformation of the 3D object; reducing deformation in a printed 3D object; and planarizing a material bed.