Disco Corporation

Yuji Hadano

Keiji Nomaru

Masatoshi Nayuki

A laser processing method includes a scattered-light blocking film stacking step of stacking a scattered-light blocking film that blocks scattered light of a laser beam on an upper surface side of a wafer, a holding step of holding a lower surface side of the wafer by a chuck table, a laser processing step of forming a layer of water on the upper surface side of the wafer and irradiating a region to be processed in the wafer with the laser beam while moving the chuck table and a laser beam irradiation unit relatively, and a scattered-light blocking film removal step of removing the scattered-light blocking film from the wafer for which the laser processing step has ended.

Laser processing method

A laser beam application unit of a laser processing machine includes a laser oscillator, a spot shaper, a polygon mirror, and a condenser. The laser oscillator emits a pulsed laser beam. The spot shaper is configured to shape a spot profile of the pulsed laser beam emitted from the laser oscillator such that the spot profile becomes long in a Y-axis direction and short in an X-axis direction. The polygon mirror disperses the spot, which has been shaped by the spot shaper, in the X-axis direction. The condenser focuses the pulsed laser beam, which has been dispersed by the polygon mirror, on a workpiece held on a chuck table.

Laser processing machine

A laser processing machine includes a condenser and a water pillar forming unit. The condenser condenses a laser beam emitted from a laser oscillator and irradiates it to a workpiece held on a chuck table. The water pillar forming unit is disposed on a lower end of the condenser and is configured to form a thread-shaped water pillar on a front side of the workpiece. The laser oscillator includes a first laser oscillator, which emits a first laser beam having a short pulse width, and a second laser oscillator, which emits a second laser beam having a long pulse width. After the laser beams emitted from the first and second laser oscillators have transmitted through the thread-shaped water pillar formed by the water pillar forming unit and have been irradiated to the workpiece, a plasma occurred in the water pillar forming unit applies processing to the workpiece.

A liquid supply mechanism disposed at an upper portion of a holding unit includes a liquid chamber having a transparent plate positioned to form a gap between itself and an upper surface of a workpiece held on a holding table, a roller formed of a transparent member that is disposed in a non-contact state at a position proximate to an upper surface of the workpiece held on the holding table inside the liquid chamber and that produces a flow of a liquid on the workpiece; a motor rotating the roller, a liquid supply nozzle supplying the liquid into the gap from one side of the liquid chamber, and a liquid discharge nozzle discharging the liquid from the other side of the liquid chamber. A laser beam is applied to the workpiece through the transparent plate, the roller, and the liquid supplied into the gap.

Laser processing apparatus

A laser processing apparatus includes a laser beam applying unit having a focusing unit applying a laser beam to a workpiece held on a chuck table, a feeding mechanism relatively moving the chuck table and the laser beam applying unit, and a chamber having a top wall connected to the focusing unit and a side wall connected to the top wall to define an enclosed space, the top wall having a transparent plate located directly below the focusing unit and allowing the pass of the laser beam applied from the focusing unit. The laser processing apparatus further includes a liquid supplying unit supplying a liquid into the enclosed space to make a condition that the enclosed space is filled with the liquid under a predetermined pressure.

A laser processing apparatus includes a liquid supply mechanism at an upper portion of a holding unit. The liquid supply mechanism includes: a liquid chamber provided with a transparent plate located with a gap formed between the transparent plate and an upper surface of a workpiece held by the holding table; a liquid supply nozzle adapted to supply a liquid to the gap from one side of the liquid chamber; and a liquid discharge nozzle adapted to recover the liquid from the other side of the liquid chamber, to produce a flow of the liquid. A laser beam applying unit includes a condenser adapted to focus a laser beam emitted by a laser oscillator, to apply the laser beam to the workpiece held by the holding table through the transparent plate and the liquid supplied to the gap.

A laser beam applying unit of a laser processing apparatus includes a laser oscillator, a condenser adapted to focus the laser beam emitted from the laser oscillator and apply the laser beam to a workpiece, and a liquid jetting apparatus disposed at a lower end portion of the condenser and adapted to jet a liquid to an upper surface of the workpiece. The liquid jetting apparatus includes: a transparent plate disposed at the lower end portion of the condenser and permitting transmission therethrough of the laser beam; a casing provided with a space defined by a ceiling wall composed of the transparent plate, side walls, and a bottom wall; an opening formed in the bottom plate, extending in a processing feeding direction, and permitting passage therethrough of the laser beam focused by the condenser; and a liquid supply section adapted to supply the liquid to the casing.

A liquid supply mechanism disposed over a holding unit of laser processing apparatus includes a liquid chamber having a circular-disc-shaped transparent plate positioned to form a gap between the circular-disc-shaped transparent plate and an upper surface of the workpiece held by the holding table, a liquid supply nozzle that supplies a liquid from one side of the liquid chamber to the gap, a liquid discharge nozzle that discharges the liquid from the other side of the liquid chamber, and a rotation mechanism that rotates the circular-disc-shaped transparent plate and generates a flow velocity in the liquid supplied to the gap. The laser beam irradiation unit includes a laser oscillator that emits a laser beam and a condenser that condenses the laser beam emitted from the laser oscillator and irradiates the workpiece with the laser beam transmitted through the transparent plate and the liquid supplied to the gap.

A laser beam applying unit of a laser processing apparatus includes a laser oscillator adapted to emit a laser beam, a condenser adapted to focus the laser beam emitted from the laser oscillator and to thereby apply the laser beam to the workpiece held by a holding unit, and a liquid layer former disposed at a lower end portion of the condenser and adapted to form a layer of a liquid on an upper surface of the workpiece. The liquid layer former includes a casing having a bottom wall that forms a gap between itself and the upper surface of the workpiece, a liquid supply section adapted to supply the liquid to the casing, and a transparent section that is formed at the bottom wall adjacently to the jet port and that permits transmission of the laser beam therethrough.

A liquid supply mechanism is disposed on an upper portion of a holding unit of a laser processing apparatus. The liquid supply mechanism includes: a liquid chamber having a transparent plate positioned such that a gap is formed between the transparent plate and the top surface of a workpiece held on a holding table; a linear-motion mechanism configured to linearly move the transparent plate over the liquid chamber; a liquid supply nozzle configured to supply a liquid from one side of the liquid chamber to the gap; and a liquid discharge nozzle configured to discharge the liquid from another side of the liquid chamber. A laser beam irradiating unit includes a laser oscillator configured to irradiate the workpiece through the transparent plate and the liquid supplied to the gap.

A laser processing apparatus has a liquid supply mechanism disposed at an upper portion of a holding unit. The liquid supply mechanism includes: a pool adapted to form a layer of a liquid on an upper surface of a workpiece held by a holding table; a transparent plate disposed such as to make contact with the layer of the liquid; a jet nozzle adapted to jet the liquid by positioning a jet port between an upper surface of the workpiece and the transparent plate toward an application position of a laser beam applied to the workpiece through the transparent plate; a liquid supply nozzle adapted to supply the liquid from one side of the pool; and a liquid discharge nozzle adapted to discharge the liquid from the other side of the pool.

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Tokyo, Japan

Yuji Hadano