Abstract: A method and apparatus for machining, or forming a feature in, a patterned silicon wafer includes removing portions of surface layers on the wafer using a first pulsed laser (4) beam with a pulse width between 1 ps and 1000 ps; and removing portions of bulk silicon (1) underlying the surface layers from the wafer using a second pulsed laser (5) beam with a wavelength between 200 nm and 1100 nm. Re-deposited silicon may be removed from the wafer by etching.

Abstract: A substrate (16) is machined to form, for example, a via. The substrate is in a chamber (15) within which the gaseous environment is controlled. The machining laser beam (13) is delivered with control of parameters such as pulsing parameters to achieve desired effects. The gaseous environment may be controlled to control integral development of an insulating lining for a via, thereby avoiding the need for downstream etching and oxide growth steps. Also, machining may be performed in multiple passes in order to minimize thermal damage and to achieve other desired effects such as a particular via geometry.

Abstract: A substrate is diced using a program-controlled pulsed laser beam apparatus having an associated memory for storing a laser cutting strategy file. The file contains selected combinations of pulse rate ?t, pulse energy density E and pulse spatial overlap to machine a single layer or different types of material in different layers of the substrate while restricting damage to the layers and maximising machining rate to produce die having predetermined die strength and yield. The file also contains data relating to the number of scans necessary using a selected combination to cut through a corresponding layer. The substrate is diced using the selected combinations. Gas handling equipment for inert or active gas may be provided for preventing or inducing chemical reactions at the substrate prior to, during or after dicing.

Abstract: A substrate is diced using a program-controlled pulsed laser beam apparatus having an associated memory for storing a laser cutting strategy file. The file contains selected combinations of pulse rate Deltat, pulse energy density E and pulse spatial overlap to machine a single layer or different types of material in different layers of the substrate while restricting damage to the layers and maximising machining rate to produce die having predetermined die strength and yield. The file also contains data relating to the number of scans necessary using a selected combination to cut through a corresponding layer. The substrate is diced using the selected combinations. Gas handling equipment for inert or active gas may be provided for preventing or inducing chemical reactions at the substrate prior to, during or after dicing.

Abstract: A semiconductor wafer having an active layer is mounted on a carrier with the active layer away from the carrier and at least partially diced on the carrier from a major surface of the semiconductor wafer. The at least partially diced semiconductor wafer is etched on the carrier from the said major surface with a spontaneous etchant to remove sufficient semiconductor material from a die produced from the at least partially diced semiconductor wafer to improve flexural bend strength of the die by removing at least some defects caused by dicing.

Abstract: A die bonding method and apparatus by which a wafer substrate 11 adhered to a carrier tape 13 by an adhesive layer 12 is laser machined through the wafer substrate and through the adhesive layer at most to scribe the carrier tape to form a singulated die 15 with an attached singulated adhesive layer, without substantial delamination of the adhesive layer 12 and carrier tape 13 or substantial production of burrs from the adhesive layer 12. The carrier tape 13 is cured, preferably by ultraviolet light, to release the adhesive layer from the carrier tape. The singulated die is picked and placed on a die pad and the adhesive layer 12 is cured, preferably by heat, to adhere the die to the die pad.

Abstract: A silicon workpiece 5 is machined by a laser 2 with a laser beam 4 with a wavelength of less than 0.55 microns by providing a halogen environment for the silicon workpiece to form an active assist gas for laser machining. The laser beam is focussed onto the silicon workpiece at a power density above an ablation threshold of silicon so that the assist gas reacts with the silicon workpiece at or near a focus of the laser beam such that laser machining speed is increased and strength of the machined workpiece is increased due to an improvement in machining quality. The invention has particular application in the dicing of a silicon wafer in the presence of sulphur hexafluoride (SF6), resulting in increased strength of resultant dies.

Abstract: A silicon body W is machined with a UV or green laser beam 6 in a refrigerated liquid halide compound environment. Local heating with the laser beam of the liquid halide compound in the vicinity of a machining location is sufficient to cause a chemical reaction between the silicon body and the liquid halide compound which accelerates machining, enhances machining quality and reduces laser machining generated debris.

Abstract: An illumination head (1) for machine vision has an annular support (2) with first, second, third, and fourth illumination sections (3, 4, 5, and 6). The third section (5) has three sets of LEDs (12, 13, 14) arranged in a pattern so that each set illuminates at approximately the same angle. Each set is driven in succession so that a series of three monochrome images at the same angle are captured. These are superimposed by an image processor to provide a color image, although the camera is monochrome. More information can be obtained in such a color image and the high resolution and robustness of monochrome cameras is availed of.

Abstract: A substrate (30) is diced using a program-controlled pulsed laser beam (35) apparatus having an associated memory for storing a laser cutting strategy file. The file contains selected combinations of pulse rate ?t, pulse energy density E and pulse spatial overlap to machine a single layer or different types of material in different layers (31, 32, 33, 34) of the substrate while restricting damage to the layers and maximising machining rate to produce die having predetermined die strength and yield. The file also contains data relating to the number of scans necessary using a selected combination to cut through a corresponding layer. The substrate is diced using the selected combinations. Gas handling equipment for inert or active gas may be provided for preventing or inducing chemical reactions at the substrate prior to, during or after dicing.

Abstract: A semiconductor is cut by directing a green laser beam of high power, and subsequently directing a UV beam along the cut line. The first beam performs cutting with relatively rough edges and a high material removal rate, and the second beam completes the cut at the edges for the required finish, with a lower material quantity removal.

Abstract: A formation in a first surface of a substrate is machined by an ultraviolet or visible radiation laser, to a predetermined depth that is less than a full depth of the substrate; and material is removed from a second surface of the substrate opposed to the first surface to the predetermined depth from the first surface to communicate with the formation. Material may be removed by, for example, lapping and polishing, chemical etching, plasma etching or laser ablation. The invention has application in, for example, dicing semiconductor wafers to forming metallised vias in wafers.

Abstract: Electronic circuits such as IC packages, circuit boards, of flex circuits are singulated by laser cutting of adjoining laminated material. The laser beam has a wavelength of less than 400 nm, and either a minimum energy density of 100 J/cm2 or a minimum power density of 1GW/cm2. The method avoids the need for cleaning and intermediate handling, and there is a greatly improved throughput.

Abstract: An inspection station (6) has a ring of 370 nm LEDs (24) for low-angle diffuse illumination of flux. This stimulates inherent fluorescent emission of the flux without the need for flux additives or pre-treatment. A CCD sensor (20) detects the emission. An image processor generates output data indicating flux volume according to a relationship between emission intensity and volume over the surface of the flux. Intensity non-uniformity indicates either height non-uniformity or hidden voids, both of which give rise to defects after application of solder paste and reflow. The inspection is particularly effective for pre solder application flux inspection.

Abstract: A system has a projection lens directing on-axis light and low level LEDs directing light to blind microvias. A high resolution camera captures blind microvia images and an image processor recognizes defects according to classifications according to reflected light area and centroid position. The lens is telecentric for particularly effective image capture in blind microvias. The system also has an array of 6000 back lighting LEDs providing illumination for capture of images by a camera. These images are analyzed by the image processor to detect defects such as blocked through microvias.

Abstract: Electronic circuits such as IC packages, circuit boards, of flex circuits are singulated by laser cutting of adjoining laminated material. The laser beam has a wavelength of less than 400 nm, and either a minimum energy density of 100 J/cm2 or a minimum power density of 1GW/cm2. The method avoids the need for cleaning and intermediate handling, and there is a greatly improved throughput.

Abstract: A measurement system (1) has a camera with a lens (12) and a separate sensor (10) mounted so that their planes (13,11) intersect at an object plane (3) according to the Scheimpflug principle. A reference camera(4) is normal and provides a 2D normal image which is used by an image processor (25) to determine a calibration image. This allows the image processor to determine height of the object (2). A single image capture provides an image of the full object, such as a ball grid array (BGA).

Abstract: A UV laser beam is used to machine semiconductor. The beams intensity (IB) is chosen so that it lies in a range of such values for which there is an increasing (preferably linear) material removal rate for increasing IB An elongate formation such as a trough or a slot is machined in n scans laterally offset (O_centre), for each value of z-integer in the z direction.

Abstract: A substrate (16) is machined to form, for example, a via. The substrate is in a chamber (15) within which the gaseous environment is controlled. The machining laser beam (13) is delivered with control of parameters such as pulsing parameters to achieve desired effects. The gaseous environment may be controlled to control integral development of an insulating lining for a via, thereby avoiding the need for downstream etching and oxide growth steps. Also, machining may be performed in multiple passes in order to minimize thermal damage and to achieve other desired effects such as a particular via geometry.

Abstract: An illumination head (1) for machine vision has an annular support (2) with first, second, third, and fourth illumination sections (3, 4, 5, and 6). The third section (5) has three sets of LEDs (12, 13, 14) arranged in a pattern so that each set illuminates at approximately the same angle. Each set is driven in succession so that a series of three monochrome images at the same angle are captured. These are superimposed by an image processor to provide a color image, although the camera is monochrome. More information can be obtained in such a color image and the high resolution and robustness of monochrome cameras is availed of.