Abstract: A cross-coupling control method for moving beam of gantry machine tool is disclosed, which relates to the technical field of CNC machine tool control. The cross-coupling control method includes: Step 1: establishing a crossbeam dynamics model considering a ram on the crossbeam, and at the same time simplifying the model for an observer design; step 2: realizing a PID control parameter adjustment of motors at both ends in accordance with a method of parameter tuning of a unilateral servo control system; using a servo system with the same control parameters to jointly drive the crossbeam up and down, realizing the synchronous control and realizing PID control parameter tuning for both end motors. The disclosure not only reduces the synchronization error caused by the torsion of the crossbeam, but also solves the synchronization error caused by the asymmetric load on both sides, and improves the system robustness and stability.

Abstract: A method of processing a warped workpiece includes a warpage eliminating step of applying a laser beam whose wavelength is transmittable through the workpiece to the workpiece while positioning a focused spot of the laser beam in the workpiece at a predetermined first position thicknesswise across the workpiece, thereby forming modified layers in the workpiece and cracks extending from the modified layers to a lower surface of the workpiece along all of projected dicing lines on the workpiece, thereby eliminating the warpage from the workpiece, and a modified layer forming step of, after the warpage eliminating step, applying the laser beam to the workpiece while positioning the focused spot of the laser beam in the workpiece at a position above the first position away from the lower surface of the workpiece, thereby forming modified layers in the workpiece along the projected dicing lines.

Abstract: A workpiece processing method includes holding a workpiece unit on a holding table and forming a division start point. The workpiece unit has a workpiece having a front side and a back side, and an additional member formed on the back side of the workpiece. The additional member is different in material from the workpiece. The workpiece unit is held on the holding table with the additional member opposed to the holding table. The division start point is formed by applying a laser beam to the front side of the workpiece with the focal point of the laser beam set inside the workpiece. The laser beam forms a modified layer inside the workpiece and simultaneously forming a division start point inside the additional member due to the leakage of the laser beam from the focal point toward the back side of the workpiece.

Abstract: A wafer processing method includes an affixing step of affixing a wafer to a sheet via a die attach layer having a diameter larger than a diameter of the wafer, to thereby form a protruding portion of the die attach layer on a periphery of the wafer, and a protruding portion removing step of removing the protruding portion from the sheet by bringing a removing member into contact with the protruding portion.

Abstract: A stacked wafer processing method for processing one wafer of a stacked wafer having at least two layers laminated, includes a sheet laying step of laying a thermocompression bonding sheet on an upper face of the one wafer, a thermocompression bonding step of thermocompression-bonding the thermocompression bonding sheet to an outer peripheral portion of the one wafer where a chamfered portion is formed, a modified layer forming step of irradiating the stacked wafer with a laser beam having a transmission wavelength to the thermocompression bonding sheet and the one wafer from the thermocompression bonding sheet side with a focal point of the laser beam positioned inside the outer peripheral portion of the one wafer, thereby continuously forming a modified layer inside the one wafer, and a chamfered portion removing step of expanding the thermocompression bonding sheet to break the chamfered portion, thereby removing the chamfered portion from the one wafer.

Abstract: A tape attaching method for attaching a tape to a workpiece includes a placing step of placing the workpiece with respect to the tape, which has a base material and an adhesive layer on the base material, in such a manner that the adhesive layer is in contact with an attached face of the workpiece, and a close contact step of causing, after the placing step is performed, a ball to roll in contact with the base material of the tape, thereby to bring the tape in close contact with the workpiece.

Abstract: A wafer processing method includes a sheet bonding step of placing a polyolefin or polyester sheet on a front side of a wafer having a device area where devices are formed so as to be separated by division lines, the sheet having a size capable of covering the device area, and next performing thermocompression bonding to bond the sheet to the front side of the wafer, thereby protecting the front side of the wafer with the sheet. The method further includes a test element group (TEG) cutting step of applying a first laser beam through the sheet to the wafer along each division line thereby cutting a TEG formed on each division line, and a modified layer forming step of applying a second laser beam to a back side of the wafer along each division line, the second laser beam having a transmission wavelength to the wafer, thereby forming a modified layer inside the wafer along each division line.

Abstract: A processing method for a wafer includes the steps of forming a frame unit having a ring-shaped frame, providing a resin sheet, fixing the resin sheet, which covers the wafer at its front side, at its outer peripheral edge, on the ring-shaped frame, forming through-holes in the resin sheet, holding the frame unit on a side of the resin sheet under suction on a holding surface to fix the ring-shaped frame, applying a laser beam to the wafer to form modified layers inside the wafer, and separating the resin sheet. In the holding step, the adhesive tape is suctioned under a negative pressure acting from the holding surface via through-holes while the front side of the wafer is prevented by the resin sheet from being suctioned on the holding surface.

Abstract: A workpiece processing method includes a protective film forming step of coating an upper surface of a wafer with a protective film including a water-soluble resin, a laser processing step of applying a laser beam of such a wavelength as to be absorbed in the wafer to the upper surface to subject the wafer to ablation, and a cleaning step of removing the protective film from the upper surface of the wafer together with debris generated in the laser processing step. The cleaning step includes a first cleaning sub-step of spinning a spinner table holding the wafer and supplying a cleaning fluid to the upper surface of the wafer and a second cleaning sub-step of supplying a mixed fluid of gas and the cleaning fluid to the upper surface of the wafer held by the spinning spinner table, to clean the wafer.

Abstract: A method of processing a wafer with a metal film to divide the wafer into individual device chips along a grid of projected dicing lines where the mechanical strength of the wafer is reduced. The method includes the steps of sticking a holding tape to a face side of the wafer, holding the wafer while a reverse side of the wafer with the metal film thereon is being exposed, and drawing the wafer under suction along the projected dicing lines to fracture the wafer along the projected dicing lines while the reverse side of the wafer is being cooled in its entirety.

Abstract: A processing method for a wafer includes the steps of forming a frame unit having a ring-shaped frame, providing a resin sheet, fixing the resin sheet, which covers the wafer at its front side, at its outer peripheral edge, on the ring-shaped frame, forming through-holes in the resin sheet, holding the frame unit on a side of the resin sheet under suction on a holding surface to fix the ring-shaped frame, applying a laser beam to the wafer to form modified layers inside the wafer, and separating the resin sheet. In the holding step, the adhesive tape is suctioned under a negative pressure acting from the holding surface via through-holes while the front side of the wafer is prevented by the resin sheet from being suctioned on the holding surface.

Abstract: An expanding method includes a frame securing step of securing an annular frame of a workpiece unit with frame securing means, an expanding step of, after the frame securing step, pressing a portion of an expandable sheet that lies between an outer circumferential edge of the workpiece and an inner circumferential edge of the annular frame, with an expanding drum to expand the expandable sheet, and a heating step of, after the expanding step, heating and shrinking a slackening portion of the expandable sheet which has been formed by expansion of the expandable sheet. The heating step includes a fully circumferential heating step of heating a full outer circumferential portion of the workpiece and an additional heating step of additionally heating a local area of the full outer circumferential portion of the workpiece.

Abstract: A workpiece processing method includes holding a workpiece unit on a holding table and forming a division start point. The workpiece unit has a workpiece having a front side and a back side, and an additional member formed on the back side of the workpiece. The additional member is different in material from the workpiece. The workpiece unit is held on the holding table with the additional member opposed to the holding table. The division start point is formed by applying a laser beam to the front side of the workpiece with the focal point of the laser beam set inside the workpiece. The laser beam forms a modified layer inside the workpiece and simultaneously forming a division start point inside the additional member due to the leakage of the laser beam from the focal point toward the back side of the workpiece.

Abstract: A wafer processing method includes: a wafer providing step of providing a wafer by placing a thermoplastic polymer sheet on an upper surface of a substrate on which the wafer is supported and positioning a back surface of the wafer on an upper surface of the polymer sheet; a sheet thermocompression bonding step of evacuating an enclosing environment in which the wafer is provided through the polymer sheet on the substrate, heating the polymer sheet, and pressing the wafer toward the polymer sheet to pressure-bond the wafer through the polymer sheet to the substrate; and a dividing step of positioning a cutting blade on the front surface of the wafer and cutting the wafer along the division lines to divide the wafer into individual device chips.

Abstract: A tape attaching method for attaching a tape to a workpiece includes a placing step of placing the workpiece with respect to the tape, which has a base material and an adhesive layer on the base material, in such a manner that the adhesive layer is in contact with an attached face of the workpiece, and a close contact step of causing, after the placing step is performed, a ball to roll in contact with the base material of the tape, thereby to bring the tape in close contact with the workpiece.

Abstract: A stacked wafer processing method for processing one wafer of a stacked wafer having at least two layers laminated, includes a sheet laying step of laying a thermocompression bonding sheet on an upper face of the one wafer, a thermocompression bonding step of thermocompression-bonding the thermocompression bonding sheet to an outer peripheral portion of the one wafer where a chamfered portion is formed, a modified layer forming step of irradiating the stacked wafer with a laser beam having a transmission wavelength to the thermocompression bonding sheet and the one wafer from the thermocompression bonding sheet side with a focal point of the laser beam positioned inside the outer peripheral portion of the one wafer, thereby continuously forming a modified layer inside the one wafer, and a chamfered portion removing step of expanding the thermocompression bonding sheet to break the chamfered portion, thereby removing the chamfered portion from the one wafer.

Abstract: A wafer processing method includes a grouping step of dividing a wafer along division lines demarcating a plurality of devices as one block on the wafer to form a plurality of group pieces, a reattaching step of attaching one of the group pieces to an expansion tape, a modified layer forming step of emitting a laser beam having a wavelength transmittable through the wafer along the division lines for each group piece to form modified layers, a dividing step of expanding the expansion tape, and dividing each of the group pieces in which the modified layers are formed into individual devices.

Abstract: A wafer processing method includes: a wafer providing step of providing a wafer by placing a thermoplastic polymer sheet on an upper surface of a substrate on which the wafer is supported and positioning a back surface of the wafer on an upper surface of the polymer sheet; a sheet thermocompression bonding step of evacuating an enclosing environment in which the wafer is provided through the polymer sheet on the substrate, heating the polymer sheet, and pressing the wafer toward the polymer sheet to pressure-bond the wafer through the polymer sheet to the substrate; and a dividing step of positioning a cutting blade on the front surface of the wafer and cutting the wafer along the division lines to divide the wafer into individual device chips.

Abstract: A wafer processing method includes a sheet bonding step of placing a polyolefin or polyester sheet on a front side of a wafer having a device area where devices are formed so as to be separated by division lines, the sheet having a size capable of covering the device area, and next performing thermocompression bonding to bond the sheet to the front side of the wafer, thereby protecting the front side of the wafer with the sheet. The method further includes a test element group (TEG) cutting step of applying a first laser beam through the sheet to the wafer along each division line thereby cutting a TEG formed on each division line, and a modified layer forming step of applying a second laser beam to a back side of the wafer along each division line, the second laser beam having a transmission wavelength to the wafer, thereby forming a modified layer inside the wafer along each division line.

Abstract: An expanding method for expanding an expandable sheet is provided. A wafer is attached to a central portion of the expandable sheet and an annular frame is attached to a peripheral portion of the expandable sheet. The expanding method includes an annular frame holding step of holding the annular frame by using a holding unit, an expanding step of pushing the expandable sheet by using a pushing unit, thereby expanding the expandable sheet, a suction holding step of holding the wafer through the expandable sheet on a holding table under suction, and a push force removing step of removing a push force applied from the pushing unit to the expandable sheet. A minute projection for preventing the shrinkage of the expandable sheet is formed on the holding table along the outer circumference thereof.