JP2015050400A - Plate-like material holding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate-like material holding system by which an operator can locate a plate-like material on a holding table when applying circular-processing of a predetermined size to the plate-like material.SOLUTION: The plate-like material holding system for holding a plate-like material when applying circular-processing of a predetermined size to the plate-like material comprises: a holding table having a holding face with a larger size than that of the plate-like material and holding the plate-like material, and a rotation shaft passing through a center of the holing face and orthogonal to the holding face; and a light source unit including a light source, and a mask arranged between the light source and the holding face and having an aligning pattern, and arranged above the holding table. When the light source is lit on, a positioning mark for positioning the plate-like material so that the center of the circular processing applied to the plate-like material is positioned at the center of the holding face is formed on the holding face.

Description

  The present invention relates to a plate-like object holding system for holding a plate-like object when circular processing of a predetermined size is performed on the plate-like object.

  The diameter of semiconductor wafers tends to increase to 8 inches, 30 cm, and even 45 cm in order to improve productivity. Along with this, processing equipment such as diffusion furnaces, CVD equipment, grinding equipment, dicing equipment, etc. Is also responding to the increased diameter of wafers.

  On the other hand, since a small-diameter wafer may have better production efficiency, a disk may be cut out from a plate-like workpiece such as a wafer (see, for example, JP-A-11-54461). .

  When a disk is cut out from a plate-like object, the holding table is rotated around a rotation axis passing through the center of the holding surface of the holding table (chuck table), and the position is separated from the center of the holding surface by a predetermined distance in the radial direction. Is processed by the processing means, and circular processing is performed on the plate-like object.

  When a plurality of disks are cut out from a plate-like object using such a circular process, the plate-like object is aligned with the center of the area to be circularly processed and the center of the holding surface of the holding table. Need to be remounted on the holding table each time.

  Many processing apparatuses are provided with a plate-shaped object transport mechanism, and are automatic processing apparatuses that automatically transport a plate-shaped object onto a holding table by the transport mechanism and perform predetermined processing. As disclosed in Japanese Patent No. 13312, there is also known a so-called manual type processing apparatus that does not include a transport mechanism, and in which an operator places a plate-like object on a holding table and unloads the plate-like object from the holding table. It has been.

Japanese Patent Laid-Open No. 11-54461 JP 2006-13312 A

  However, in a manual type processing apparatus, it is extremely difficult for an operator to place a plate-like object on the holding table in a state where the center of the area to be circularly processed and the center of the holding surface of the holding table are aligned. It is difficult.

  In particular, when performing a plurality of circular processes, there is a demand to perform as many circular processes as possible on a single plate-like object, but the areas that have already been processed do not overlap the areas to be circular processed. There is a problem that it takes much time to adjust and place the plate-like object on the holding table.

  The present invention has been made in view of these points, and the object of the present invention is to make it easy for an operator to place a plate-like object on a holding table when performing circular processing of a predetermined size on the plate-like object. It is providing the holding | maintenance system of the plate-shaped object which can be mounted.

  According to the present invention, there is provided a plate-like object holding system for holding a plate-like object when circular processing of a predetermined size is performed on the plate-like object, the holding surface having a size larger than the plate-like object and holding the plate-like object. A holding table having a center of the holding surface and a rotation axis perpendicular to the holding surface, a light source, and a mask having a pattern for alignment disposed between the light source and the holding surface, A light source unit disposed above the holding table, and when the light source is turned on, for positioning the plate-like object so that the center of circular processing applied to the plate-like object is positioned at the center of the holding surface A plate-like object holding system is provided in which a positioning mark is formed on the holding surface.

  Preferably, the positioning mark forms a contour of circular processing applied to the plate-like object on the plate-like object. As an alternative embodiment, the positioning mark indicates the outline of a plate-like object placed on the holding surface.

  According to the plate-like object holding system of the present invention, since the positioning mark can be formed on the holding surface of the holding table, the operator can easily place the plate-like object on the holding table in accordance with the positioning mark.

  According to invention of Claim 2, since the outline of the circular process performed on a plate-shaped object is projected on a plate-shaped object, even when performing several circular processes on a plate-shaped object, for example, the area which has already been processed It is possible to easily position the plate-like object while avoiding the above.

It is a perspective view of the laser processing apparatus provided with the workpiece holding system of the present invention. It is a partial cross section side view explaining a holding system. It is a top view of the holding table in which the circular positioning mark was formed on the holding surface. FIG. 4A is a plan view of the holding table in a state where a circular positioning mark that forms a contour of circular processing is formed on the plate-like object at the center of the plate-like object, and FIG. 4B is a plate-like object. It is a top view of the holding table in the state where a circular positioning mark was formed on the plate-like object having a circular processing mark on it when processed next. It is a top view of the holding table of the state in which the outline of the plate-shaped object mounted on a holding table is projected as a positioning mark.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a perspective view of a laser processing apparatus 2 provided with a workpiece holding system according to an embodiment of the present invention is shown. The laser processing apparatus 2 includes a first slide block 6 mounted on a stationary base 4 so as to be movable in the X-axis direction.

  The first slide block 6 is moved in the machining feed direction, that is, the X-axis direction along the pair of guide rails 14 by the machining feed mechanism 12 including the ball screw 8 and the pulse motor 10.

  A second slide block 16 is mounted on the first slide block 6 so as to be movable in the Y-axis direction. That is, the second slide block 16 is moved in the indexing direction, that is, the Y-axis direction along the pair of guide rails 24 by the indexing feed mechanism 22 including the ball screw and the pulse motor 20.

  A holding table (chuck table) 28 is mounted on the second slide block 16 via a cylindrical support member 26, and the holding table 28 is moved in the X-axis direction and the Y-axis direction by the processing feed mechanism 12 and the index feed mechanism 22. Can be moved to. The holding table 28 is provided with a clamp 30 that clamps a plate-like object such as a semiconductor wafer sucked and held by the holding table 28.

  A support base 32 is mounted on the stationary base 4. A casing (frame body) 36 containing a laser beam irradiation means 34 is attached to the support base 32. That is, the casing 36 is fixed to the support base 32 by fixing the pair of attachment portions 36 a of the casing 36 to the support base 32 with the fixing bolts 38.

  A condenser 40 that collects the laser beam and irradiates the plate-like object held on the holding table 28 is attached to the tip of the casing 36. The laser beam irradiation means 34 includes a laser beam oscillator that oscillates the laser beam and an optical system that guides the laser beam oscillated from the laser beam oscillator to the condenser 40.

  At the front end of the casing 36, an image pickup unit 42 including a condenser 40 and a camera such as a CCD camera that is aligned in the X-axis direction and detects a processing region to be laser processed by a laser beam is disposed. .

  When the power source of the laser processing apparatus 2 is cut off, the holding table 28 is moved by the processing feed mechanism 12 and the indexing feed mechanism 22 to return to the original position where the plate-like object is placed on the holding table 28 and stopped. .

  As shown in FIG. 2, the holding table 28 includes a frame 29 formed of a metal such as SUS, and a suction holding unit 31 formed of porous ceramics surrounded by the frame 29. 31 is selectively connected to a suction source 37 through a suction path 33 and an electromagnetic switching valve 35 formed in the cylindrical support member 26. The holding table 28 is rotated around a rotation axis 28 a orthogonal to the holding surface 31 a of the suction holding unit 31.

  In the present embodiment, the light source unit 44 is attached to the support base 32 so that the center of the light source unit 44 is positioned directly above the center of the holding surface 31a of the holding table 28 positioned at the original position. The light source unit 44 may be attached to an apparatus frame (not shown) of the laser processing apparatus 2.

  The light source unit 44 includes a light source 46 composed of an LED, a white light source, and the like, and a mask 48 that is detachably attached to the light source unit 44. The mask 48 has a pattern such as a circular pattern for alignment through which light is transmitted.

  A plurality of types of masks 48 having patterns having different diameters are prepared, and the mask 48 is selected according to the size (diameter) of the positioning mark formed on the holding surface 31a of the holding table 28 and attached to the light source unit 44. .

  In the present embodiment, since the distance between the light source unit 44 and the holding surface 31 a of the holding table 28 is a predetermined distance that has been known in advance, the holding surface of the holding table 28 according to the mask 48 attached to the light source unit 44. The diameter of the positioning mark 50 formed on 31a is known in advance.

  As shown in FIG. 2, when the light source 46 of the light source unit 44 is turned on with respect to the holding table 28 positioned at the original position and light is irradiated to the holding surface 31 a of the holding table 28 through the mask 48, FIG. As shown in FIG. 3, a positioning mark 50 is formed on the holding surface 31a through the alignment pattern of the mask 48. In the present embodiment, the positioning mark 50 is used as a contour of circular processing applied to a workpiece such as a wafer.

  When it is desired to perform circular processing at the center of the plate-like object, the operator can set the plate-like object 11 so that the center of the plate-like object 11 coincides with the center of the positioning mark 50 as shown in FIG. Is mounted on the holding surface 31a.

  In laser processing of the workpiece 11, since the radius of the positioning mark 50 is known in advance, the processing feed mechanism 12 is driven to position the plate-like object 11 in advance from directly below the condenser 40. The holding table 28 is moved to a position close to or far from the radius of the mark 50 for use.

  In this state, when the holding table 28 is rotated at least once while irradiating a laser beam having a wavelength that is transmissive to the plate-like object from the condenser 40 of the laser beam irradiation unit 36, A circular modified layer is formed as a division starting point corresponding to the positioning mark 50.

  As an alternative embodiment, when a laser beam having an absorptive wavelength is irradiated from the condenser 40 to the plate-like object 11, a circular groove corresponding to the positioning mark 50 is formed in the plate-like object 11 by ablation processing. . You may make it utilize this circular groove | channel as a division | segmentation starting point.

  After forming a processing mark 52 such as a circular modified layer or a circular groove in the center of the plate-like object 11, the processing feed mechanism 12 is driven to return the holding table 28 to the original position. In this state, the light source unit 44 is actuated to form the positioning mark 50, and as shown in FIG. 4B, the operator has the processing mark 52 adjacent to the positioning mark 50 projected on the plate-like object. The plate-like object 11 is repositioned so that it does.

  Next, the processing feed mechanism 12 is driven to move the holding table 28 from a position immediately below the condenser 50 to a position that is closer to or farther away from the radius of the positioning mark 50. Then, by rotating the holding table 28 at least once while irradiating a laser beam having a wavelength transmissive to the plate-like object 11 from the condenser 50, the circular modification corresponding to the positioning mark 50 is formed inside the wafer 11. A quality layer is formed. When the plate-like object 11 is irradiated with a laser beam having an absorptive wavelength, a circular groove corresponding to the positioning mark 50 is formed on the plate-like object 11.

  After forming the machining mark 52 in the peripheral portion in this way, the machining feed mechanism 12 is driven to return the holding table 28 to the original position, and the operator has a circular modified layer or a circular groove where the plate-like object 11 is to be formed next. Reposition so that it is positioned directly under the light source unit 44.

  Next, after the positioning mark 50 is formed at a new position on the plate-like object 11, the holding table 28 is moved to the processing position to form a circular modified layer inside the plate-like object 11 or the plate-like object 11. A circular groove is formed on the surface.

  By repeatedly replacing the workpiece 11 at the original position and forming the positioning mark 50 and laser processing after driving the processing feed mechanism 12 and positioning the holding table 28 at the processing position, the plate The maximum number of circular modified layers or circular grooves that can be formed on the plate-like object 11 is formed on the object 11.

  Next, when the plate-like object 11 is removed from the holding surface 31a of the holding table 28 and attached to, for example, an expanded tape, and the expandable tape is expanded, an external force in the radial direction is applied to the plate-like object 11, the plate-like object 11 Is divided into a plurality of discs starting from a circular modified layer or a circular groove.

  Next, another embodiment of the plate-like object holding system of the present invention will be described with reference to FIG. In the present embodiment, the positioning mark 54 indicating the outline of the plate-like object placed on the holding surface 31a of the holding table 28 on the holding surface 31a of the holding table 28 by the light source unit 44 or the outline of the plate-like object placed outside the center. A positioning mark 54a is formed. The positioning marks 54 and 54a may be formed separately or simultaneously.

  Then, the operator places a plate-like object corresponding to the positioning mark 54 in the center of the holding table 28 at the original position, moves the holding table 28 to the processing position, and performs laser processing on the plate-like object 11. .

  In the case where the positioning mark 54a indicating the outline of the plate-like object is formed at a place other than the center of the holding surface 31a, a plurality of notches 56 spaced apart by a predetermined interval in the circumferential direction are formed on the positioning mark 54a. May be.

  For example, when the plate-like object 11 is a wafer having a notch, the wafer is placed on the holding table 28 so that the contour of the wafer coincides with the positioning mark 54, and the center of the wafer, that is, the center of the holding table 28. After the circular processing is performed on the wafer, the holding table 28 is returned to the original position, and the wafer is mounted in alignment with the positioning mark 54a so that the notch of the wafer is aligned with the notch 56 of the positioning mark 54a.

  After carrying out circular laser processing on the wafer at the center of the holding table at the laser processing position, the holding table 28 is returned to the original position again, and the wafer is repositioned so that the notch of the wafer coincides with the next notch 56 adjacent thereto.

  In this state, the holding table 28 is moved to the processing position, and the wafer is subjected to circular laser processing. By repeating this one after another, a desired number of laser processing can be performed on the wafer.

  In the above-described embodiment, an example in which laser processing is performed by the laser processing apparatus 2 after the plate-like object is held on the holding table 28 using the plate-like object holding system of the present invention has been described. It is not limited to laser processing, and circular processing may be performed along the positioning mark 50 by a cutting blade of a cutting device.

2 Laser processing apparatus 12 Processing feed mechanism 22 Indexing feed mechanism 28 Holding table 31a Holding surface 34 Laser beam irradiation unit 40 Condenser 42 Imaging unit 44 Light source unit 46 Light source 48 Mask 50 Positioning mark 52 Processing mark 54 Mounted in the center Positioning mark 54a indicating the outline of the plate-like object Positioning mark 56 indicating the outline of the plate-like object to be placed other than the center Notch

Claims (3)

A plate-like object holding system for holding a plate-like object when performing circular processing of a predetermined size on the plate-like object,
A holding table having a size larger than the plate-like object and holding the plate-like object, and a rotation axis passing through the center of the holding surface and perpendicular to the holding surface;
A light source unit including a light source and a mask disposed between the light source and the holding surface and having a pattern for alignment, and a light source unit disposed above the holding table,
When the light source is turned on, a positioning mark for positioning the plate-like object is formed on the holding surface so that the center of the circular processing applied to the plate-like object is positioned at the center of the holding surface. Plate holding system.   2. The plate-like object holding system according to claim 1, wherein the positioning mark forms a contour of a circular process applied to the plate-like object on the plate-like object.   2. The plate-like object holding system according to claim 1, wherein the positioning mark indicates an outline of the plate-like object placed on the holding surface.

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