Hamamatsu-photonics K.k.

Olympus Corporation

Hamamatsu Photonics Kabushiki Kaisha

Tetsuya Osajima

Koji Kuno

Norio Kurita

Takashi Inoue

Masayoshi Kumagai

Makoto Nakano

Kazuhiro Atsumi

Tatsuya Suzuki

Yukio Eda

Sadashi Adachi

Kenshi Fukumitsu

Fumitsugu Fukuyo

Toshimitsu Wakuda

Ryuji Sugiura

Kenichi Muramatsu

Masayoshi Kusunoki

Kazuhito Kawai

An object is irradiated with a laser light modulated by a reflection type spatial light modulator such that aberration of the laser light converged inside the object becomes a predetermined aberration or less. Therefore, aberration of the laser light generated at a position on which a converging point of the laser light is located is made as small as possible, to enhance the energy density of the laser light at that position, which makes it possible to form a modified region with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator is used, it is possible to improve the utilization efficiency of the laser light as compared with a transmissive type spatial light modulator.

Laser working method, laser working apparatus, and its manufacturing method

An apparatus comprises a table, a source emitting polarized laser light, a source emitting laser light, a plate changing the polarization direction of the laser light, a plate splitting the laser light into a laser light having polarization in an X direction and a laser light component having polarization in a Y direction, a plate orienting the polarization direction of the laser light to the X direction, a lens converging the laser light components, a lens arranged in parallel with the lens along the X direction and converges the laser light component, a control section controlling a device such that a converging point of the laser light component is located at a predetermined position with reference to a front face by detecting a reflected light, and a control section moving the table along a line while making the X direction substantially coincide with the line.

Laser processing device

A laser processing apparatus comprises a converging lensfor converging processing laser light and rangefinding laser light Ltoward a wafer, an actuator for actuating the lens, a shaping optical systemfor adding astigmatism to reflected light Lof the rangefinding laser light, a quadrant photodiodefor receiving the reflected light Land outputting voltage values corresponding to its light quantities, and a controller for regulating the actuator, and positions a converging point Pof the rangefinding laser light Lbetween a focal point Pof the lens and the lens, so as to make it possible to form a modified region at a position deeper from the front face, thereby suppressing adverse effects due to the reflected light L. The control is based on an arithmetic value subjected to a division by a sum of the voltage values, so as to prevent the arithmetic value from being changed by the quantity of reflected light.

Laser material processing system

In the laser processing method, the cross-sectional form of laser light L at a converging point P is such that the maximum length in a direction perpendicular to a line to cutis shorter than the maximum length in a direction parallel to the line to cut. Therefore, when seen from the incident direction of the laser light L, a modified regionformed within a silicon waferhas such a shape that the maximum length in the direction perpendicular to the line to cutis shorter than the maximum length in the direction parallel to the line to cut. Forming the modified regionhaving such a shape within the objectcan restrain twist hackles from occurring on cut surfaces when cutting the objectfrom the modified regionacting as a cutting start point, thereby making it possible to improve the flatness of the cut surfaces.

Laser processing method for forming a modified region for cutting in an object

An object to be processedis irradiated with a laser light L modulated by a reflection type spatial light modulatorsuch that aberration of the laser light L converged inside the objectbecomes a predetermined aberration or less. Therefore, aberration of the laser light L generated at a position on which a converging point P of the laser light L is located is made as small as possible, to enhance the energy density of the laser light L at that position, which makes it possible to form a modified regionwith a high function as a starting point for cutting. In addition, because the reflection type spatial light modulatoris used, it is possible to improve the utilization efficiency of the laser light L as compared with a transmissive type spatial light modulator. Such improvement of the utilization efficiency of the laser light L is particularly important in the case in which the modified regionserving as a starting point for cutting is formed in the plate-shaped object

A laser condensing optical system of the present invention includes a laser beam source which emits a laser beam, a condensing optical system which is arranged between the laser beam source and a medium and condenses the laser beam in the medium, and a laser divergence point moving unit which can move the position of a laser divergence point of the laser beam along an optical axis of the laser beam in accordance with the refractive index of the medium in which the laser beam is desired to be condensed and the distance from a surface of the medium to a position where the beam is desired to be condensed.

A shutter unit capable of preventing the scattering of the laser beam upon closing the optical path of the laser beam and capable of being miniaturized, and a laser processing device employing such a shutter unit. In a shutter unit, when the optical path of the laser beam L is opened, a rotating memberis rotated around an axis line &#x3b3;, and an openingis positioned on an optical axis &#x3b1; so as to pass the laser beam L therethrough. Meanwhile, when the optical path of the laser beam L is closed, the rotating memberis rotated and a reflective surfaceis positioned on the optical axis &#x3b1; so as to reflect the laser beam L. Here, since the reflected laser beam L is absorbed by an optical absorption member, it is possible to prevent the scattering of the laser beam L when the optical path of the laser beam L is closed. In addition, since the openingand reflective surfaceare both formed on the rotating memberwhich rotates around the axis line &#x3b3; that is substantially orthogonal to the optical axis &#x3b1;, it is possible to reduce the size of the shutter unit

Shutter unit and laser processing device using same

To provide a laser processing apparatus which can converge a laser beam for processing an object to be processed at a position as close as possible to a predetermined position. This laser processing apparatus is one for irradiating an object to be processed with a processing laser beam while positioning a converging point within the object so as to form a modified region caused by multiphoton absorption within the object along a line along which, the object should be cut in the object, and comprises an objective lens unitincluding a processing objective lenswhich converges the processing laser beam and a rangefinding laser beam for measuring a displacement of a main surface of the object on an identical axis, a light-receiving partwhich receives a reflected light beam of the rangefinding laser beam on the main surface, and an actuatorwhich holds the processing objective lensaccording to the received reflected light beam such that the lensis capable of freely advancing and retracting with respect to the main surface; and a housingto which a laser unit for emitting the processing laser beam is attached. The objective lens unitis detachably attached to the housing

Laser beam machining system

A laser processing apparatus which can suppress the positional fluctuation in light-converging point of laser light during laser processing is provided. On an optical path of laser light Lconnecting a beam expanderand a first light-transmitting holeof a lens holderto each other in a laser processing apparatus, a stop memberincluding a second light-transmitting holehaving the same diameter as that of the first light-transmitting holeis disposed. Hence, the amount of laser light Lcut by the surrounding part of the first light-transmitting holecan substantially be eliminated, whereby the lens holdercan be prevented from being heated upon irradiation with the laser light L. Also, even when the stop memberis heated by the laser light Lcut by the surrounding part of the second light-transmitting hole, heat is prevented from being transmitted from the stop memberto the lens holder, since the stop memberis separated from the lens holder. Therefore, the positional fluctuation in light-converging point Pof the laser light Lduring laser processing can be suppressed to a low level.

A light emitting end face side front end part of an optical fiber bundleis covered by a sleeve memberand an emitting part outer cover. A glass rod holding member, which holds a glass rod, is mounted to emitting part outer cover. Glass rodis fixed to glass rod holding memberby means of positioning pinsand a light incidence end facethereof opposes a light emitting end faceof optical fiber bundle. A light emitting end faceof glass rodhas a rectangular shape. The light emitting from light emitting end faceis made uniform in illuminance across the entirety of its cross section and the cross section thereof is shaped to a rectangular shape in the process of being propagated while being totally reflected at the boundary surface of glass rod

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Hamamatsu, Japan

Tetsuya Osajima