JP2020045270A - Manufacturing method of chip - Google Patents

Abstract

To provide a manufacturing method of chips capable of manufacturing a plurality of chips by dividing a tabular workpiece without using an expanded sheet.SOLUTION: A manufacturing method of chips includes a first laser processing step for irradiating only chip region along a division scheduled line with a laser beam of a wavelength having permeability through a glass substrate to form a first modified layer along the division scheduled line of the chip region, a second laser processing step for irradiating a border between the chip region and a peripheral surplus region with a laser beam of a wavelength having permeability through the glass substrate to form a second modified layer along the border, and a dividing step for applying force to the glass substrate to divide the glass substrate into each chip. In the dividing step, a plurality of holders hold each of a plurality of parts of the glass substrate to be divided by one or a plurality of the division scheduled lines and the glass substrate is divided into each chip along a plurality of the division scheduled lines by applying the force for relatively transferring a plurality of holders to the holders in the direction for separating the holders from each other.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a chip manufacturing method for manufacturing a plurality of chips by dividing a plate-shaped workpiece.

  In order to divide a plate-shaped workpiece (work) represented by a wafer into multiple chips, a transparent laser beam is focused inside the workpiece and modified by multiphoton absorption. A method of forming a modified layer (modified region) is known (for example, see Patent Document 1). Since the modified layer is more brittle than other regions, the modified layer is formed along the planned dividing line (street), and then a force is applied to the workpiece to process the modified layer as a starting point. Objects can be split into multiple chips.

  When a force is applied to the workpiece on which the modified layer is formed, for example, a method is employed in which an expandable expandable sheet (expanded tape) is attached to the workpiece and expanded. reference). In this method, usually, before forming a modified layer on a workpiece by irradiating a laser beam, an expanded sheet is attached to the workpiece, and then the expanded sheet is expanded after forming a modified layer. The work piece is divided into a plurality of chips.

JP-A-2002-192370 JP 2010-206136 A

  However, in the method of expanding the expanded sheet as described above, since the used expanded sheet cannot be used again, the cost required for manufacturing the chip tends to be high. In particular, a high-performance expandable sheet in which the adhesive material is unlikely to remain on the chip is expensive, and thus the use of such an expandable sheet increases the cost required for manufacturing the chip.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a chip manufacturing method capable of manufacturing a plurality of chips by dividing a plate-shaped workpiece without using an expanded sheet. It is to be.

  According to one embodiment of the present invention, a plurality of chips are formed from a glass substrate having a chip region divided into a plurality of regions to be chips by a plurality of intersecting dividing lines, and an outer peripheral surplus region surrounding the chip region. A method for manufacturing a chip, comprising: a holding step of directly holding a glass substrate on a holding table; and a focusing point of a laser beam having a wavelength that is transparent to the glass substrate after performing the holding step. Irradiating the laser beam only to the chip area of the glass substrate along the planned dividing line so as to position the inside of the glass substrate held by the holding table, and irradiating the laser beam along the planned dividing line of the chip area. A first laser processing step of forming the first modified layer and using the extra peripheral region as a reinforcing portion where the first modified layer is not formed; and performing the holding step. After that, along the boundary between the chip area and the outer peripheral surplus area so as to locate the focal point of the laser beam having a wavelength that is transparent to the glass substrate inside the glass substrate held by the holding table. Irradiating the laser beam to form a second modified layer along the boundary; performing the first laser processing step and the second laser processing step; A carrying out step of carrying out the substrate, and a dividing step of applying a force to the glass substrate to divide the glass substrate into the individual chips after performing the carrying out step, wherein the dividing step includes one or more The plurality of portions of the glass substrate divided by the dividing line are respectively held by a plurality of holding portions, and are relatively moved with respect to the plurality of holding portions in a direction away from each other. In a manner that is divided along a glass substrate by applying a force to the plurality of the dividing lines, a manufacturing method of a chip dividing the glass substrate into individual said chip is provided.

  In one embodiment of the present invention, after the first laser processing step and the second laser processing step are performed, before the division step is performed, the method may further include a reinforcing part removing step of removing the reinforcing part. . In one embodiment of the present invention, the upper surface of the holding table is made of a flexible material, and in the holding step, the front side of the glass substrate may be held by the flexible material.

  In the method for manufacturing a chip according to one embodiment of the present invention, in a state where the glass substrate is directly held by the holding table, the laser beam is irradiated only to the chip region of the glass substrate, and the first modified layer along the line to be divided Is formed, and a laser beam is applied to the boundary between the chip region and the outer peripheral surplus region to form a second modified layer along the boundary. The glass substrate is divided into individual chips by a method in which the glass substrate is divided along a plurality of planned dividing lines by applying a force for moving the glass substrate in a direction away from each other with respect to the plurality of holding units, holding the glass substrate with the holding unit. Therefore, it is not necessary to use an expanded sheet to divide the glass substrate into individual chips by applying a force to the glass substrate. As described above, according to the method for manufacturing a chip according to one embodiment of the present invention, a plurality of chips can be manufactured by dividing a glass substrate which is a plate-shaped workpiece without using an expanded sheet.

  In the method for manufacturing a chip according to one embodiment of the present invention, a laser beam is applied only to a chip region of a glass substrate to form a first modified layer along a line to be divided, and a surplus outer peripheral region is subjected to a first modification. Since the reinforcing portion has no reinforcing layer, the chip region is reinforced by the reinforcing portion. Therefore, the glass substrate is not divided into individual chips due to the force applied during transportation or the like, and the glass substrate cannot be properly transported.

It is a perspective view which shows the example of a structure of a to-be-processed object typically. It is a perspective view showing typically the example of composition of a laser processing device. FIG. 3A is a cross-sectional view for explaining a holding step, and FIG. 3B is a cross-sectional view for explaining a first laser processing step. FIG. 6 is a cross-sectional view for describing a second laser processing step. FIG. 5A is a plan view schematically showing the state of the workpiece after the modified layer is formed, and FIG. 5B is a cross-sectional view schematically showing the state of the modified layer. It is. It is sectional drawing for demonstrating a reinforcement part removal step. It is a perspective view which shows the example of a structure of a division | segmentation apparatus etc. typically. FIG. 8A is a cross-sectional view schematically showing a part of the dividing device, and FIG. 8B is an enlarged cross-sectional view showing a part of FIG. FIG. 4 is a perspective view for describing a state in which a workpiece is sucked and held in a dividing step. FIG. 10A is a cross-sectional view for explaining a state in which the workpiece is sucked and held in the dividing step, and FIG. 10B is a view illustrating a state in which the workpiece is divided in the dividing step. FIG. It is sectional drawing for demonstrating the holding step concerning a modification. FIG. 12A is a cross-sectional view for describing a dividing step according to a modification, and FIG. 12B is a diagram illustrating a state of a workpiece before dividing a chip region in the dividing step according to the modification. It is a top view which shows typically.

  An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. The chip manufacturing method according to the present embodiment includes a holding step (see FIG. 3A), a first laser processing step (see FIG. 3B), a second laser processing step (see FIG. 4), and unloading. This includes a step, a reinforcing portion removing step (see FIG. 6), and a dividing step (see FIGS. 7, 8A, 8B, 9, 10A, and 10B).

  In the holding step, a workpiece (work) having a chip area divided into a plurality of areas by the planned division line and an outer peripheral surplus area surrounding the chip area is directly held by a chuck table (holding table). In the first laser processing step, a workpiece is irradiated with a laser beam having a wavelength having transparency so as to form a modified layer (first modified layer) along a line to be divided in the chip region, and The surplus region is defined as a reinforcing portion where no modified layer is formed.

  In the second laser processing step, the workpiece is irradiated with a laser beam having a wavelength having transparency and a modified layer (second modified layer) is formed along the boundary between the chip region and the outer peripheral surplus region. . In the unloading step, the workpiece is unloaded from the chuck table. In the reinforcing portion removing step, the reinforcing portion is removed from the workpiece. In the dividing step, a plurality of portions of the workpiece divided by the planned dividing line are respectively held by a plurality of holding portions, and a force for relatively moving the plurality of holding portions in a direction away from each other is applied to the plurality of holding portions. The workpiece is divided into a plurality of chips by a method of dividing the object along a plurality of dividing lines. Hereinafter, the method for manufacturing a chip according to the present embodiment will be described in detail.

FIG. 1 is a perspective view schematically showing a configuration example of a workpiece (work) 11 used in the present embodiment. As shown in FIG. 1, the workpiece 11 is made of, for example, a semiconductor such as silicon (Si), gallium arsenide (GaAs), indium phosphide (InP), gallium nitride (GaN), silicon carbide (SiC), or sapphire. (Al ₂ O ₃ ), dielectric (insulator) such as soda glass, borosilicate glass, quartz glass, or ferroelectric (ferroelectric) such as lithium tantalate (LiTaO ₃ ) or lithium niobate (LiNbO ₃ ) (A body crystal).

  The surface 11a side of the workpiece 11 is partitioned into a plurality of regions 15 to be chips by a plurality of intersection lines (streets) 13 that intersect. In the following, a substantially circular region including all of the plurality of regions 15 to be chips is referred to as a chip region 11c, and a ring-shaped region surrounding the chip region 11c is referred to as an outer peripheral surplus region 11d.

  In each area 15 in the chip area 11c, an IC (Integrated Circuit), a MEMS (Micro Electro Mechanical Systems), an LED (Light Emitting Diode), an LD (Laser Diode), a photodiode (Photodiode), a SAW Devices such as a (Surface Acoustic Wave) filter and a BAW (Bulk Acoustic Wave) filter are formed.

  By dividing the workpiece 11 along the dividing line 13, a plurality of chips can be obtained. Specifically, when the workpiece 11 is a silicon wafer, for example, a chip that functions as a memory, a sensor, or the like is obtained. When the workpiece 11 is a gallium arsenide substrate, an indium phosphide substrate, or a gallium nitride substrate, for example, a chip that functions as a light emitting element, a light receiving element, or the like is obtained.

  When the workpiece 11 is a silicon carbide substrate, for example, a chip that functions as a power device or the like is obtained. When the workpiece 11 is a sapphire substrate, for example, a chip that functions as a light emitting element or the like is obtained. When the workpiece 11 is a glass substrate made of soda glass, borosilicate glass, quartz glass, or the like, for example, a chip that functions as an optical component or a cover member (cover glass) is obtained.

  When the workpiece 11 is a ferroelectric substrate (ferroelectric crystal substrate) made of a ferroelectric material such as lithium tantalate or lithium niobate, for example, a chip that functions as a filter, an actuator, or the like is obtained. The material, shape, structure, size, thickness, and the like of the workpiece 11 are not limited. Similarly, there is no limitation on the type, quantity, shape, structure, size, arrangement, and the like of devices formed in the region 15 to be a chip. A device may not be formed in the region 15 to be a chip.

  In the chip manufacturing method according to the present embodiment, a plurality of chips are manufactured using a disk-shaped glass substrate as the workpiece 11. Specifically, first, a holding step of holding the workpiece 11 directly on the chuck table is performed. FIG. 2 is a perspective view schematically illustrating a configuration example of a laser processing apparatus used in the present embodiment.

  As shown in FIG. 2, the laser processing apparatus 2 includes a base 4 on which each component is mounted. On the upper surface of the base 4, a horizontal moving mechanism for moving a chuck table (holding table) 6 for sucking and holding the workpiece 11 in the X-axis direction (processing feed direction) and the Y-axis direction (index feed direction). 8 are provided. The horizontal moving mechanism 8 includes a pair of X-axis guide rails 10 fixed to the upper surface of the base 4 and substantially parallel to the X-axis direction.

  An X-axis moving table 12 is slidably attached to the X-axis guide rail 10. A nut (not shown) is provided on the back surface (lower surface side) of the X-axis moving table 12, and an X-axis ball screw 14 that is substantially parallel to the X-axis guide rail 10 is screwed into the nut. ing.

  An X-axis pulse motor 16 is connected to one end of the X-axis ball screw 14. When the X-axis ball screw 14 is rotated by the X-axis pulse motor 16, the X-axis moving table 12 moves in the X-axis direction along the X-axis guide rail 10. At a position adjacent to the X-axis guide rail 10, an X-axis scale 18 for detecting the position of the X-axis moving table 12 in the X-axis direction is installed.

  A pair of Y-axis guide rails 20 that are substantially parallel to the Y-axis direction are fixed to the surface (upper surface) of the X-axis moving table 12. A Y-axis moving table 22 is slidably attached to the Y-axis guide rail 20. A nut (not shown) is provided on the back surface (lower surface side) of the Y-axis moving table 22, and a Y-axis ball screw 24 substantially parallel to the Y-axis guide rail 20 is screwed into the nut. ing.

  A Y-axis pulse motor 26 is connected to one end of the Y-axis ball screw 24. When the Y-axis ball screw 24 is rotated by the Y-axis pulse motor 26, the Y-axis moving table 22 moves in the Y-axis direction along the Y-axis guide rail 20. At a position adjacent to the Y-axis guide rail 20, a Y-axis scale 28 for detecting the position of the Y-axis moving table 22 in the Y-axis direction is installed.

  A support table 30 is provided on the front surface side (upper surface side) of the Y-axis moving table 22, and the chuck table 6 is disposed above the support table 30. The front surface (upper surface) of the chuck table 6 is a holding surface 6a that sucks and holds the back surface 11b side (or the front surface 11a side) of the workpiece 11 described above. The holding surface 6a is made of, for example, a porous material having high hardness such as aluminum oxide. However, the holding surface 6a may be made of a flexible material typified by a resin such as polyethylene or epoxy.

  The holding surface 6a is connected to a suction source 34 (see FIG. 3 (A)) through a suction path 6b (see FIG. 3A) formed inside the chuck table 6, a valve 32 (see FIG. 3 (A)) and the like. A) etc.). A rotation drive source (not shown) is provided below the chuck table 6, and the chuck table 6 is rotated by the rotation drive source around a rotation axis substantially parallel to the Z-axis direction.

  Behind the horizontal moving mechanism 8, a columnar support structure 36 is provided. A support arm 38 extending in the Y-axis direction is fixed to an upper portion of the support structure 36. A wavelength having a transmittance to the workpiece 11 (a wavelength that is hardly absorbed) is provided at the tip of the support arm 38. A laser irradiation unit 40 for oscillating the laser beam 17 (see FIG. 3B) of the laser beam 17 and irradiating the workpiece 11 on the chuck table 6 with a pulse is provided.

  At a position adjacent to the laser irradiation unit 40, a camera 42 for imaging the front surface 11a side or the back surface 11b side of the workpiece 11 is provided. The image formed by imaging the workpiece 11 or the like with the camera 42 is used, for example, when adjusting the position or the like between the workpiece 11 and the laser irradiation unit 40.

  Components such as the chuck table 6, the horizontal moving mechanism 8, the laser irradiation unit 40, and the camera 42 are connected to a control unit (not shown). The control unit controls each component so that the workpiece 11 is appropriately processed.

  FIG. 3A is a cross-sectional view for explaining the holding step. Note that in FIG. 3A, some components are shown as functional blocks. In the holding step, as shown in FIG. 3A, for example, the back surface 11 b of the workpiece 11 is brought into contact with the holding surface 6 a of the chuck table 6. Then, the valve 32 is opened to apply the negative pressure of the suction source 34 to the holding surface 6a.

  As a result, the workpiece 11 is sucked and held on the chuck table 6 with the front surface 11a exposed upward. In this embodiment, as shown in FIG. 3A, the back surface 11b side of the workpiece 11 is directly held by the chuck table 6. That is, in the present embodiment, there is no need to attach an expanded sheet to the workpiece 11.

  After the holding step, the laser beam 17 is irradiated along the planned dividing line 13 to form a modified layer (first modified layer), and the laser beam 17 is irradiated with the chip region 11c and the outer peripheral surplus. Irradiation is performed along the boundary with the region 11d to perform a second laser processing step of forming a modified layer (second modified layer). In the present embodiment, a case will be described in which the second laser processing step is performed after the first laser processing step.

  FIG. 3B is a cross-sectional view for explaining a first laser processing step, FIG. 4 is a cross-sectional view for explaining a second laser processing step, and FIG. FIG. 5B is a plan view schematically illustrating a state of the workpiece 11 after the layer 19 is formed, and FIG. 5B is a cross-sectional view schematically illustrating the modified layer 19. Note that in FIG. 3B and FIG. 4, some components are shown by functional blocks.

  In the first laser processing step, first, the chuck table 6 is rotated so that, for example, the direction in which the target division planned line 13 extends is parallel to the X-axis direction. Next, the chuck table 6 is moved to adjust the position of the laser irradiation unit 40 on an extension of the target division line 13. Then, as shown in FIG. 3B, the chuck table 6 is moved in the X-axis direction (that is, the direction in which the target division planned line 13 extends).

  Thereafter, at the timing when the laser irradiation unit 40 reaches just above one of the boundaries between the chip region 11c and the outer peripheral surplus region 11d existing at two locations on the target dividing line 13, the laser processing unit 40 Irradiation of the object 11 with the laser beam 17 having a wavelength having transparency is started. In the present embodiment, as shown in FIG. 3B, a laser beam 17 is emitted from a laser irradiation unit 40 disposed above the workpiece 11 toward the surface 11 a of the workpiece 11.

  The irradiation with the laser beam 17 is continued until the laser irradiation unit 40 reaches the position just above the other boundary between the chip region 11c and the outer peripheral surplus region 11d existing at two locations on the target divisional line 13. That is, here, the laser beam 17 is applied only to the chip region 11c along the target scheduled division line 13.

  The laser beam 17 is emitted so as to position the focal point at a position at a predetermined depth from the front surface 11a (or the back surface 11b) inside the workpiece 11. In this way, by condensing the laser beam 17 having a wavelength that is transmissive to the workpiece 11 inside the workpiece 11, a part of the workpiece 11 is focused at and near the focal point. The modified layer 19 (modified layer 19a or the like) serving as a starting point of division can be formed by being modified by multiphoton absorption.

  In the first laser processing step of the present embodiment, since the laser beam 17 is applied only to the chip region 11c along the target division line 13, the laser beam 17 is irradiated only to the chip region 11c along the target division line 13. The quality layer 19 is formed. That is, as shown in FIG. 5B, in the first laser processing step, the modified layer 19 is not formed in the outer peripheral surplus region 11d.

  After the reformed layer 19 is formed at a predetermined depth along the target division line 13, the modified layer 19 is formed at another depth along the target division line 13 in the same procedure. 19 is formed. In the present embodiment, as shown in FIG. 5B, for example, the modified layer 19 (modified layer 19a, modified layer 19a) is placed at three different positions from the front surface 11a (or the back surface 11b) of the workpiece 11. The material layer 19b and the modified layer 19c) are formed.

  However, there is no particular limitation on the number and position of the modified layers 19 formed along one dividing line 13. For example, the number of the modified layers 19 formed along one dividing line 13 may be one. Further, it is desirable that the modified layer 19 is formed under the condition that the crack reaches the front surface 11a (or the back surface 11b). Of course, the modified layer 19 may be formed under the condition that the crack reaches both the front surface 11a and the back surface 11b. Thereby, the workpiece 11 can be more appropriately divided.

  After forming the required number of modified layers 19 along the target division lines 13, the above procedure is repeated to form the modification layers 19 along all other division lines 13. As shown in FIG. 5A, when the required number of modified layers 19 are formed along all the planned dividing lines 13, the first laser processing step ends.

  In this first laser processing step, after forming a required number of modified layers 19 along one planned dividing line 13, a similar modified layer 19 is formed along another planned dividing line 13. However, there is no particular limitation on the order of forming the modified layer 19 and the like. For example, the modified layer 19 may be formed at the same depth position in all the planned dividing lines 13 and then the modified layer 19 may be formed at another depth position.

When the workpiece 11 is a silicon wafer, for example, the modified layer 19 is formed under the following conditions.
Workpiece: Silicon wafer Laser beam wavelength: 1340 nm
Laser beam repetition frequency: 90 kHz
Laser beam output: 0.1W ~ 2W
Moving speed (working feed speed) of chuck table: 180 mm / s to 1000 mm / s, typically 500 mm / s

When the workpiece 11 is a gallium arsenide substrate or an indium phosphide substrate, for example, the modified layer 19 is formed under the following conditions.
Workpiece: gallium arsenide substrate, indium phosphide substrate Laser beam wavelength: 1064 nm
Laser beam repetition frequency: 20 kHz
Laser beam output: 0.1W ~ 2W
Moving speed of chuck table (working feed speed): 100 mm / s to 400 mm / s, typically 200 mm / s

When the workpiece 11 is a sapphire substrate, for example, the modified layer 19 is formed under the following conditions.
Workpiece: Sapphire substrate Wavelength of laser beam: 1045 nm
Laser beam repetition frequency: 100 kHz
Laser beam output: 0.1W ~ 2W
Moving speed (working feed speed) of chuck table: 400 mm / s to 800 mm / s, typically 500 mm / s

When the workpiece 11 is a ferroelectric substrate made of a ferroelectric material such as lithium tantalate or lithium niobate, for example, the modified layer 19 is formed under the following conditions.
Workpiece: lithium tantalate substrate, lithium niobate substrate Laser beam wavelength: 532 nm
Laser beam repetition frequency: 15 kHz
Laser beam power: 0.02W ~ 0.2W
Moving speed of chuck table (processing feed speed): 270 mm / s to 420 mm / s, typically 300 mm / s

When the workpiece 11 is a glass substrate made of soda glass, borosilicate glass, quartz glass, or the like, the modified layer 19 is formed under the following conditions, for example.
Workpiece: soda glass substrate, borosilicate glass substrate, quartz glass substrate Laser beam wavelength: 532 nm
Laser beam repetition frequency: 50 kHz
Laser beam output: 0.1W ~ 2W
Moving speed of chuck table (processing feed speed): 300 mm / s to 600 mm / s, typically 400 mm / s

When the workpiece 11 is a gallium nitride substrate, for example, the modified layer 19 is formed under the following conditions.
Workpiece: gallium nitride substrate Wavelength of laser beam: 532 nm
Laser beam repetition frequency: 25 kHz
Laser beam power: 0.02W ~ 0.2W
Moving speed (working feed speed) of chuck table: 90 mm / s to 600 mm / s, typically 150 mm / s

When the workpiece 11 is a silicon carbide substrate, for example, the modified layer 19 is formed under the following conditions.
Workpiece: Silicon carbide substrate Laser beam wavelength: 532 nm
Laser beam repetition frequency: 25 kHz
Laser beam output: 0.02 W to 0.2 W, typically 0.1 W
Movement speed of the chuck table (processing feed speed): 90 mm / s to 600 mm / s, typically 90 mm / s in the cleavage direction of the silicon carbide substrate and 400 mm / s in the non-cleavage direction.

  In the first laser processing step of the present embodiment, the modified layer 19 (modified layer 19a, 19b, 19c) is formed only in the chip region 11c along the dividing line 13, and the modified layer 19 is formed in the outer peripheral surplus region 11d. Since the layer 19 is not formed, the strength of the workpiece 11 is maintained by the outer peripheral surplus region 11d. As a result, the workpiece 11 is not divided into individual chips due to the force applied during transportation or the like. Thus, the outer peripheral surplus region 11d after the first laser processing step functions as a reinforcing portion for reinforcing the chip region 11c.

  Further, in the first laser processing step of the present embodiment, since the modified layer 19 is not formed in the outer peripheral surplus region 11d, for example, cracks extending from the modified layer 19 reach both the front surface 11a and the back surface 11b, and Even when the workpiece 11 is completely divided, each chip does not fall off or separate. Generally, when the modified layer 19 is formed on the workpiece 11, the workpiece 11 expands near the modified layer 19. In the present embodiment, the expansion force generated by the formation of the modified layer 19 is applied inwardly in the ring-shaped outer peripheral surplus region 11d functioning as a reinforcing portion, thereby pressing down each chip and reducing its drop-out and discreteness. Preventing.

  After the above-described first laser processing step, a second laser processing step is performed. In the second laser processing step, first, the chuck table 6 is moved to adjust the position of the laser irradiation unit 40 on the boundary between the chip area 11c and the outer peripheral surplus area 11d. Then, as shown in FIG. 4, the chuck table 6 is rotated while irradiating the workpiece 11 with the laser beam 17 having a transmissive wavelength from the laser irradiation unit 40. That is, in the present embodiment, the laser beam 17 is emitted from the laser irradiation unit 40 disposed above the workpiece 11 toward the surface 11 a of the workpiece 11.

  The laser beam 17 is irradiated so as to position the focal point at a position at a predetermined depth from the front surface 11a (or the back surface 11b) inside the workpiece 11. In this way, by condensing the laser beam 17 having a wavelength that is transmissive to the workpiece 11 inside the workpiece 11, a part of the workpiece 11 is focused at and near the focal point. The modified layer 19 (modified layer 19d) serving as a starting point of division can be formed by modification by multiphoton absorption.

  In the second laser processing step of the present embodiment, since the laser beam 17 is applied along the boundary between the chip region 11c and the outer peripheral surplus region 11d, the modified layer 19 is formed along this boundary. Note that there is no particular limitation on the number or position of the modified layers 19 formed along the boundary between the chip region 11c and the outer peripheral surplus region 11d. For example, the number of modified layers 19 formed along the boundary may be two or more.

  Further, it is desirable that the modified layer 19 along this boundary is formed under the condition that the crack reaches the front surface 11a (or the back surface 11b). Of course, the modified layer 19 may be formed along the boundary under the condition that the crack reaches both the front surface 11a and the back surface 11b. As a result, the workpiece 11 can be more appropriately divided, and the outer peripheral surplus region 11d can be separated from the chip region 11c.

  There are no particular restrictions on the specific conditions and the like for forming the modified layer 19 in the second laser processing step. For example, it is possible to form the modified layer 19 along the boundary under the same conditions as those for forming the modified layer 19 in the first laser processing step. Of course, the modified layer 19 along the boundary may be formed under conditions different from the conditions for forming the modified layer 19 in the first laser processing step.

  As shown in FIGS. 5A and 5B, when an annular modified layer 19 (modified layer 19d) is formed along the boundary between the chip region 11c and the outer peripheral surplus region 11d, the second laser is formed. The processing step ends. In the present embodiment, the modified layer 19 (modified layer 19d) is formed at a position at the same depth as the modified layer 19 (modified layer 19b) formed in the first laser processing step. The cracks reach the front surface 11a and the back surface 11b from the modified layer 19 (modified layer 19d).

  After the first laser processing step and the second laser processing step, an unloading step of unloading the workpiece 11 from the chuck table 6 is performed. Specifically, for example, the entire surface 11a of the workpiece 11 is sucked by a transport unit (not shown) that can suck and hold the entire front surface 11a (or the back surface 11b) of the workpiece 11, and then the valve 32 is closed to shut off the negative pressure of the suction source 34, and the workpiece 11 is carried out. In the present embodiment, as described above, since the outer peripheral surplus region 11d functions as a reinforcing portion, the workpiece 11 is divided into individual chips by a force applied during transportation or the like, and the workpiece 11 is divided into individual chips. 11 cannot be properly transported.

  After the carrying-out step, a reinforcing portion removing step of removing the reinforcing portion from the workpiece 11 is performed. FIG. 6 is a cross-sectional view for explaining the reinforcing portion removing step. In FIG. 6, some components are shown by functional blocks. The reinforcing portion removing step is performed using, for example, the workpiece holding device 52 shown in FIG.

  The workpiece holding device 52 includes a chuck table (holding table) 54 for sucking and holding the workpiece 11. A part of the upper surface of the chuck table 54 is a holding surface 54a for sucking and holding the chip area 11c of the workpiece 11. The holding surface 54a is connected to a suction source 58 via a suction path 54b, a valve 56, and the like formed inside the chuck table 54.

  The chuck table 54 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis substantially parallel to the vertical direction. The chuck table 54 is supported by, for example, a moving mechanism (not shown), and moves in a direction substantially parallel to the above-described holding surface 54a.

  In the reinforcing portion removing step, first, the back surface 11 b of the workpiece 11 is brought into contact with the holding surface 54 a of the chuck table 54. Then, the valve 56 is opened to apply the negative pressure of the suction source 58 to the holding surface 54a. Thereby, the workpiece 11 is sucked and held on the chuck table 54 in a state where the surface 11a side is exposed upward. In this embodiment, as shown in FIG. 6, the back surface 11b side of the workpiece 11 is directly held by the chuck table 54. That is, also here, there is no need to attach an expanded sheet to the workpiece 11.

  Next, an upward force (a force away from the holding surface 54a) is applied to the outer peripheral surplus region 11d. As described above, the modified layer 19 (modified layer 19d) serving as a starting point of division is formed at the boundary between the chip region 11c and the outer peripheral surplus region 11d. Therefore, by applying an upward force to the outer peripheral surplus region 11d, the outer peripheral surplus region 11d can be lifted and removed from the chuck table 54 as shown in FIG. As a result, only the chip region 11c of the workpiece 11 remains on the chuck table 54.

  After the reinforcing portion removing step, a dividing step of dividing the workpiece 11 into individual chips is performed. Specifically, a plurality of portions of the workpiece 11 divided by the scheduled division line 13 are respectively held by a plurality of holding portions, and a force for relatively moving the plurality of holding portions in a direction away from each other is applied to the plurality of holding portions. The workpiece 11 is divided by a method of dividing the workpiece 11 along a plurality of scheduled dividing lines 13.

  FIG. 7 is a perspective view schematically illustrating a configuration example of a dividing device and the like used in the dividing step of the present embodiment, and FIG. 8A is a cross-sectional view schematically illustrating a part of the dividing device. FIG. 8B is a cross-sectional view showing a part of FIG. 8A in an enlarged manner. As shown in FIGS. 7, 8A and 8B, the dividing device 72 includes a plurality of electrostatic attraction members (holding portions) 74 arranged at substantially equal intervals. Each of the electrostatic attraction members 74 is formed in a rectangular parallelepiped shape (a flat plate or a rod shape) that is long in a predetermined direction, and has an upper surface (attraction surface) 74a and a lower surface side (for example, a back surface 11b side) of the workpiece 11. Is absorbed and held.

  The length of the upper surface 74a of the electrostatic attraction member 74 (the length along the above-described predetermined direction) is, for example, larger than the diameter of the workpiece 11 (in the present embodiment, the chip region 11c) to be divided. long. On the other hand, the width (the length in the direction perpendicular to the above-described predetermined direction) of the upper surface 74 a of the electrostatic attraction member 74 is smaller than the interval between two adjacent division lines 13 in the workpiece 11. . Therefore, a portion (a portion corresponding to a small piece after division) between two adjacent scheduled division lines 13 of the workpiece 11 can be attracted and held by the electrostatic attracting member 74.

  There is no particular limitation on the number of the electrostatic suction members 74, but, for example, the processing is performed along all the planned dividing lines 13 extending in the first direction (or the second direction intersecting the first direction) of the workpiece 11. It is preferable to use a number of electrostatic attraction members 74 that can divide the object 11 at one time. In this case, the workpiece 11 is moved at once along all the division lines 13 extending in the first direction (or the second direction) without shifting and repositioning the workpiece 11 with respect to the electrostatic attraction member 74. Can be split.

  On the lower surface 74b of each electrostatic attraction member 74, two (two) strip-like elastic sheets (two) extending in a direction perpendicular to the above-described predetermined direction (that is, the longitudinal direction of each of the electrostatic attraction members 74). Application mechanisms) 76a and 76b are fixed by an adhesive 78 (FIG. 8B). Specifically, one elastic sheet 76a is fixed to one end side of each electrostatic attraction member 74 in the longitudinal direction.

  The other elastic sheet 76b is fixed to the other end in the longitudinal direction of each electrostatic attraction member 74. Each of the elastic sheets 76a and 76b is made of a high elastic material such as rubber, for example, and has a predetermined elasticity. The two elastic sheets 76a and 76b connect the electrostatic attraction members 74 in a state of being arranged in a direction perpendicular to the longitudinal direction.

  However, there is no particular limitation on the material, structure, quantity, arrangement, and the like of the elastic sheets 76a and 76b. For example, a woven or knitted fabric made of stretchable or non-stretchable fibers may be used as the elastic sheets 76a and 76b. In the present embodiment, the plurality of electrostatic attraction members 74 are connected by the two elastic sheets 76a and 76b, but one (one) or three (three) or more elastic sheets are used. A plurality of electrostatic attraction members 74 can also be connected.

  One end of each of the elastic sheets 76a, 76b is fixed to a cylindrical (columnar) roller (applying mechanism) 80a having a rotation axis substantially parallel to the longitudinal direction of the electrostatic attraction member 74. The roller 80a is connected to a rotation drive source (applying mechanism) 82a such as a motor, and rotates around a rotation axis by a force generated by the rotation drive source 82a.

  Similarly, the other end of each of the elastic sheets 76a and 76b is fixed to a cylindrical (columnar) roller (applying mechanism) 80b having a rotation axis substantially parallel to the longitudinal direction of each electrostatic attraction member 74. . The roller 80b is connected to a rotation drive source (applying mechanism) 82b such as a motor, and rotates around a rotation axis by a force generated by the rotation drive source 82b.

  By rotating the rollers 80a and 80b with the rotary drive sources 82a and 82b, the elastic sheets 76a and 76b are wound up by the rollers 80a and 80b, and the elastic sheets 76a and 76b are unwound from the rollers 80a and 80b. The tension applied to the sheets 76a, 76b can be adjusted.

  In the dividing device 72 of the present embodiment, two sets of rollers 80a and 80b and two sets of rotary drive sources 82a and 82b are used. For example, one set of rollers and one set of rotary drive sources are used. Equivalent functions can also be realized by using them. In this case, for example, one end (or the other end) of each of the elastic sheets 76a and 76b is fixed, and one set of rollers and one set of the rotary drive source are connected to the other end (or one end). Good.

  As shown in FIGS. 8A and 8B, the electrostatic attraction member 74 includes a columnar (rod-shaped) core 84a extending in the longitudinal direction thereof, and a conductive member 86a that covers around the core 84a. In. The conductive member 86a is made of, for example, a metal such as copper, and functions as one electrode of the electrostatic attraction member 74. There is no particular limitation on the material, shape, and the like of the core 84a, but in the present embodiment, a prismatic core 84a made of silicon is used.

  The electrostatic attraction member 74 includes a columnar (rod-shaped) core 84b extending in the longitudinal direction thereof, and a conductive member 86b that covers the periphery of the core 84b. The material and shape of the core 84b and the conductive member 86b may be the same as the material and shape of the core 84a and the conductive member 86a. The conductive member 86b functions as the other electrode of the electrostatic attraction member 74.

  The core member 84a and the conductive member 86a and the core member 84b and the conductive member 86b are arranged at predetermined intervals, and are covered with an insulating member 88. Thereby, a pair of electrodes parallel to each other is realized. The upper surface of the insulating member 88 is the upper surface 74a of the electrostatic attraction member 74, and the lower surface of the insulating member 88 is the lower surface 74b of the electrostatic attraction member 74.

  As shown in FIG. 7, one electrode (conductive member 86a) of each electrostatic attraction member 74 is connected to a positive electrode of a DC power supply (power supply unit) 94 via a wiring 90, a switch 92, and the like. The other electrode (conductive member 86b) of each electrostatic attraction member 74 is connected to the negative electrode of the DC power supply 94 via the wiring 90 and the like.

  Therefore, by turning on the switch 92 and applying the voltage of the DC power supply 94 to the electrodes of each electrostatic attraction member 74, an electric field can be generated around each of the electrostatic attraction members 74. A transport unit 96 is disposed above the plurality of electrostatic attraction members 74 and the like. The transport unit 96 transports the workpiece 11 while sucking and holding the upper surface side (for example, the front surface 11a side) of the workpiece 11.

  In the dividing step, as shown in FIG. 7, first, the upper surface side (the front surface 11a side in the present embodiment) of the workpiece 11 is sucked and held by the transport unit 96. Next, the transport unit 96 is moved so that the lower surface side (the back surface 11b side in the present embodiment) of the workpiece 11 contacts the upper surfaces 74a of the plurality of electrostatic attraction members 74. At this time, the plurality of electrostatic attraction members 74 and the workpiece 11 are aligned with each other so that the dividing line 13 extending in the first direction of the workpiece 11 is aligned with a gap between two adjacent electrostatic attraction members 74. The relative position and orientation are adjusted by the transport unit 96.

  Thereafter, by releasing the suction and holding of the workpiece 11 by the transport unit 96, the workpiece 11 can be placed on the plurality of electrostatic suction members 74. Before placing the workpiece 11 on the electrostatic attraction member 74, the switch 92 is turned off (OFF). Further, the tension applied to the elastic sheets 76a, 76b is adjusted by the rotary driving sources 82a, 82b, and the cycle (repetition cycle) at which the electrostatic attraction members 74 are arranged is set to the cycle at which the dividing lines 13 extending in the first direction are arranged. (Repeated cycle).

  After placing the workpiece 11 on the plurality of electrostatic attraction members 74, the workpiece 11 is attracted and held by the plurality of electrostatic attraction members 74. FIG. 9 is a perspective view illustrating a state where the workpiece 11 is sucked and held, and FIG. 10A is a cross-sectional view illustrating a state where the workpiece 11 is sucked and held. is there. As shown in FIG. 9, when sucking and holding the workpiece 11, the switch 92 is switched from the non-conductive state to the conductive state, and the voltage of the DC power supply 94 is applied to the electrodes of each electrostatic suction member 74. .

  As a result, an electric field is generated around each electrostatic attraction member 74, and as an effect thereof, an electrostatic force acts between the workpiece 11 and each of the electrostatic attraction members 74. The workpiece 11 is attracted to and held by each of the electrostatic attracting members 74 as shown in FIGS. 9 and 10A by this electrostatic force. The electrostatic force acting between the workpiece 11 and each of the electrostatic attraction members 74 includes a Coulomb force, a Johnson-Rahbek force, a gradient force, and the like.

  In the present embodiment, when the workpiece 11 is placed on the plurality of electrostatic attraction members 74, the position of the planned dividing line 13 extending in the first direction corresponds to a gap between two adjacent electrostatic attraction members 74. Adjust to the position. Therefore, when an electric field is generated around each electrostatic attraction member 74, a plurality of portions (portions corresponding to small pieces after division) divided by a plurality of planned division lines 13 extending in the first direction are respectively electrostatically separated. It is sucked and held by the suction member 74.

  After the workpiece 11 is attracted and held by the plurality of electrostatic attraction members 74, the workpiece 11 is divided into a plurality of small pieces along a plurality of scheduled dividing lines 13 extending in the first direction. FIG. 10B is a cross-sectional view illustrating a state where the workpiece 11 is divided. Specifically, the rollers 80a and 80b are rotated in the direction in which the elastic sheets 76a and 76b are wound, and the tension applied to the elastic sheets 76a and 76b (the tension in a direction perpendicular to a predetermined direction) is increased.

  That is, a pulling force is applied to the elastic sheets 76a and 76b in a direction perpendicular to the predetermined direction (here, a direction perpendicular to the first direction). As a result, a force is applied to each of the electrostatic attraction members 74 such that the electrostatic attraction members 74 are relatively moved in a direction perpendicular to a predetermined direction and away from each other.

  As described above, each of the plurality of scheduled division lines 13 extending in the first direction has the modified layer 19 serving as a starting point of division. The modified layer 19 is brittle compared to other regions of the workpiece 11. For this reason, the workpiece 11 is formed into a plurality of small pieces 21 along a plurality of scheduled dividing lines 13 extending in the first direction by a force transmitted through each electrostatic attraction member 74, as shown in FIG. Divided.

  After the workpiece 11 is divided into the plurality of small pieces 21 along all the division lines 13 extending in the first direction, the workpiece 11 is rotated relative to the plurality of electrostatic attraction members 74. Let it. Specifically, first, the upper surface side (the front surface 11a side in the present embodiment) of the workpiece 11 held by the plurality of electrostatic suction members 74 is sucked and held by the transport unit 96. At the same time, the switch 92 is turned off.

  Next, the transport unit 96 is raised, and the respective electrostatic attraction members 74 and the workpiece 11 are relatively rotated. Specifically, the planned division line 13 (second planned division line) extending in a second direction (in the present embodiment, a direction perpendicular to the first direction) intersecting the first direction is divided into two adjacent divided lines. The plurality of electrostatic attraction members 74 and the workpiece 11 are relatively rotated so as to match the gap between the electrostatic attraction members 74. Then, the transport unit 96 is lowered, and the lower surface side (the back surface 11b side in the present embodiment) of the workpiece 11 is again brought into contact with the upper surfaces 74a of the plurality of electrostatic suction members 74.

  Thereafter, by releasing the suction and holding of the workpiece 11 by the transport unit 96, the workpiece 11 can be mounted again on the plurality of electrostatic suction members 74. Before the workpiece 11 is placed on the electrostatic attraction member 74 again, the tension applied to the elastic sheets 76a and 76b is adjusted by the rotary drive sources 82a and 82b, and the cycle at which the electrostatic attraction members 74 are arranged (repeatedly). (Cycle) is set to the cycle (repetition cycle) in which the planned dividing lines 13 extending in the second direction are arranged.

  After placing the workpiece 11 on the electrostatic attraction member 74 again, the workpiece 11 is attracted and held by the plurality of electrostatic attraction members 74. Specifically, the switch 92 is switched from the non-conducting state to the conducting state, and the voltage of the DC power supply 94 is applied to the electrodes of each electrostatic attraction member 74. As a result, an electric field is generated around each electrostatic attraction member 74, and as an effect thereof, an electrostatic force acts between the workpiece 11 and each of the electrostatic attraction members 74. The workpiece 11 is attracted and held by each electrostatic attracting member 74 by the force of the static electricity.

  In the present embodiment, by rotating each of the electrostatic attraction members 74 and the workpiece 11 relatively, the position of the dividing scheduled line 13 extending in the second direction can be adjusted by the two adjacent electrostatic attraction members 74. It is adjusted to the position corresponding to the gap. Therefore, when an electric field is generated around each electrostatic attraction member 74, a plurality of portions (portions corresponding to small pieces after division) divided by a plurality of planned division lines 13 extending in the second direction respectively It is sucked and held by the suction member 74.

  After the workpiece 11 is attracted and held by the plurality of electrostatic attraction members 74, the workpiece 11 is divided into a plurality of small pieces along a plurality of scheduled dividing lines 13 extending in the second direction. Specifically, the rollers 80a and 80b are rotated in the direction in which the elastic sheets 76a and 76b are wound, and the tension applied to the elastic sheets 76a and 76b (the tension in a direction perpendicular to a predetermined direction) is increased.

  That is, a pulling force is applied to the elastic sheets 76a and 76b in a direction perpendicular to the predetermined direction (here, a direction perpendicular to the second direction). As a result, a force is applied to each of the electrostatic attraction members 74 such that the electrostatic attraction members 74 are relatively moved in a direction perpendicular to a predetermined direction and away from each other.

  As described above, each of the plurality of scheduled division lines 13 extending in the second direction has the modified layer 19 serving as a starting point of division. The modified layer 19 is brittle compared to other regions of the workpiece 11. For this reason, the workpiece 11 is divided into a plurality of small pieces along the plurality of planned dividing lines 13 extending in the second direction by the force transmitted through each electrostatic attraction member 74. When the workpiece 11 is divided into individual chips along all the division lines 13, the dividing step ends.

  As described above, in the chip manufacturing method according to the present embodiment, the laser beam is applied only to the chip region 11c of the workpiece 11 while the workpiece (work) 11 is directly held by the chuck table (holding table) 6. A modified layer 19 (modified layers 19a, 19b, 19c) is formed along the scheduled division line 13 by irradiating the beam 17, and the laser beam 17 is irradiated to the boundary between the chip region 11c and the outer peripheral surplus region 11d. After forming the modified layer 19 (modified layer 19d) along the boundary, a plurality of portions of the workpiece 11 divided by the dividing lines 13 are respectively held by a plurality of electrostatic adsorption members (holding portions) 74. The work pieces 11 are individually separated by applying a force to relatively move the plurality of electrostatic attraction members 74 in a direction away from each other to divide the work pieces 11 along the plurality of planned dividing lines 13. of Since split into-up, there is no need to use the expand sheet to split into individual chips by applying a force to the workpiece 11. As described above, according to the method for manufacturing a chip according to the present embodiment, a plurality of chips can be manufactured by dividing the glass substrate that is the plate-shaped workpiece 11 without using an expand sheet.

  Further, in the chip manufacturing method according to the present embodiment, the modified layer 19 (modified layers 19a, 19b, 19c) along the planned dividing line 13 by irradiating only the chip region 11c of the workpiece 11 with the laser beam 17 is provided. Is formed, and the outer peripheral surplus region 11d is a reinforcing portion where the modified layer 19 (the modified layers 19a, 19b, 19c) is not formed. Therefore, the chip region 11c is reinforced by the reinforcing portion. Therefore, the workpiece 11 is not divided into individual chips by the force applied at the time of transportation or the like, and the workpiece 11 cannot be properly transported.

  The present invention is not limited to the description of the above embodiments and the like, and can be implemented with various modifications. For example, in the above embodiment, the second laser processing step is performed after the first laser processing step, but the first laser processing step may be performed after the second laser processing step. Further, the second laser processing step can be performed in the middle of the first laser processing step.

  In the above embodiment, the back surface 11b side of the workpiece 11 is directly held by the chuck table 6 and the laser beam 17 is irradiated from the front side 11a. The laser beam 17 may be directly held on the table 6 and irradiated from the back surface 11b side.

  FIG. 11 is a cross-sectional view for describing a holding step according to a modification. In the holding step according to this modification, as shown in FIG. 11, for example, a chuck having an upper surface constituted by a porous sheet (porous sheet) 44 made of a flexible material represented by a resin such as polyethylene or epoxy. A table (holding table) 6 is preferably used.

  In the chuck table 6, the upper surface 44 a of the sheet 44 sucks and holds the surface 11 a of the workpiece 11. This can prevent damage to devices and the like formed on the front surface 11a side. The sheet 44 is a part of the chuck table 6 and is used repeatedly together with the main body of the chuck table 6 and the like.

  However, the upper surface of the chuck table 6 does not need to be formed of the above-described porous sheet 44, and is at least flexible enough not to damage devices and the like formed on the surface 11a side of the workpiece 11. What is necessary is just to be comprised with a material. Further, it is desirable that the sheet 44 is configured to be detachable from the main body of the chuck table 6 and can be replaced when it is damaged.

  Further, in the above embodiment, the reinforcing portion removing step is performed after the unloading step and before the dividing step. For example, after the first laser processing step and the second laser processing step, before the unloading step, A reinforcing portion removing step may be performed.

  Further, the step of removing the reinforcing portion can be omitted. In this case, for example, the range in which the modified layer 19 is formed in the first laser processing step and the second laser processing step is set so that the width of the reinforcing portion is about 2 mm to 3 mm from the outer peripheral edge of the workpiece 11. Adjust it. Further, for example, before dividing the chip region 11c in the dividing step, a groove serving as a starting point of division may be formed in the reinforcing portion.

  FIG. 12A is a cross-sectional view for describing a dividing step according to the modification, and FIG. 12B is a state of the workpiece before dividing the chip region 11c in the dividing step according to the modification. It is a top view which shows typically. In the dividing step according to the modified example, before the work 11 is divided into individual chips by the dividing device 72, for example, the work 11 is divided into reinforcing portions by using the cutting unit 62 provided in the work holding device 52. Is formed as a starting point of the process.

  The cutting unit 62 includes a spindle (not shown) that is a rotation axis substantially parallel to the holding surface 54a. At one end of the spindle, an annular cutting blade 64 in which abrasive grains are dispersed in a binder is mounted. A rotary drive source (not shown) such as a motor is connected to the other end of the spindle, and the cutting blade 64 mounted on one end of the spindle is rotated by a force transmitted from the rotary drive source. The cutting unit 62 is supported by, for example, an elevating mechanism (not shown), and the cutting blade 64 is moved vertically by the elevating mechanism.

  As shown in FIGS. 12 (A) and 12 (B), when forming a groove serving as a starting point of division, for example, the above-described cutting blade 64 is rotated to obtain an outer peripheral surplus region 11d (that is, a reinforcing portion). Cut into Thereby, the groove 11e serving as a starting point of division can be formed in the reinforcing portion. It is desirable that the groove 11e is formed, for example, along the dividing line 13. By forming such a groove 11e, it becomes possible to divide the chip region 11c of the workpiece 11 together with the outer peripheral surplus region 11d by the above-described dividing device 72.

  In the dividing step of the above embodiment, the back surface 11b side of the workpiece 11 is turned downward, and the back surface 11b side is suctioned and held by the plurality of electrostatic suction members 74. The front surface 11a may be directed downward, and the front surface 11a may be suctioned and held by a plurality of electrostatic suction members 74.

  Further, in the dividing device 72 of the above embodiment, the elastic sheets 76a and 76b, the rollers 80a and 80b, and the rotation driving sources 82a and 82b are used to apply a force to the plurality of electrostatic attraction members 74. There is no particular limitation on the structure of the applying mechanism for applying the force. Similarly, in the dividing device 72 of the above-described embodiment, a plurality of electrostatic attraction members 74 that attract and hold the workpiece 11 by electrostatic force are used, but instead of the plurality of electrostatic attraction members 74, A plurality of suction members (holding portions) that suck and hold the workpiece 11 by a method such as vacuum suction can be used.

  Further, there is no particular limitation on the number, shape, and the like of the electrostatic suction members (holding portions) 74 provided in the dividing device 72. For example, the dividing device 72 may include a pair of electrostatic attraction members 74 corresponding to at least one scheduled dividing line 13. In other words, the dividing device 72 may have at least two or more electrostatic attraction members 74.

  When the number of the electrostatic suction members 74 provided in the dividing device 72 is small, for example, after dividing the workpiece 11 along an arbitrary dividing line 13 extending in the first direction (or the second direction), The workpiece 11 is shifted and repositioned with respect to the electro-suction member 74, and the workpiece 11 is divided along another dividing line 13. Since such a dividing device 72 has high versatility, it can easily cope with workpieces 11 having different numbers and arrangements of the lines 13 to be divided.

  In addition, the structures, methods, and the like according to the above-described embodiments and modified examples can be appropriately changed and implemented without departing from the scope of the object of the present invention.

11 Workpiece (work)
11a Front surface 11b Back surface 11c Chip region 11d Outer peripheral surplus region 13 Planned division line (street)
Reference Signs List 15 area 17 laser beam 19, 19a, 19b, 19c, 19d modified layer 21 small piece 2 laser processing device 4 base 6 chuck table (holding table)
6a Holding surface 6b Suction path 8 Horizontal movement mechanism 10 X-axis guide rail 12 X-axis movement table 14 X-axis ball screw 16 X-axis pulse motor 18 X-axis scale 20 Y-axis guide rail 22 Y-axis movement table 24 Y-axis ball screw 26 Y-axis Pulse motor 28 Y-axis scale 30 Support base 32 Valve 34 Suction source 36 Support structure 38 Support arm 40 Laser irradiation unit 42 Camera 44 Sheet (porous sheet)
44a Upper surface 52 Work holding device 54 Chuck table (holding table)
54a Holding surface 54b Suction path 56 Valve 58 Suction source 62 Cutting unit 64 Cutting blade 72 Divider 74 Electrostatic adsorption member (holding unit)
74a Upper surface (adsorption surface)
74b Lower surface 76a, 76b Elastic sheet (providing mechanism)
78 adhesive 80a, 80b roller (application mechanism)
82a, 82b rotation drive source (providing mechanism)
84a, 84b Core material 86a, 86b Conductive member 88 Insulating member 90 Wiring 92 Switch 94 DC power supply (power supply unit)
96 transport unit

Claims (3)

A chip manufacturing method for manufacturing a plurality of chips from a glass substrate having a chip region partitioned into a plurality of regions to be chips by a plurality of intersecting planned dividing lines and an outer peripheral surplus region surrounding the chip region. hand,
A holding step of holding the glass substrate directly on a holding table,
After performing the holding step, the glass substrate is placed along the predetermined dividing line so that the focal point of the laser beam having a wavelength that is transparent to the glass substrate is positioned inside the glass substrate held by the holding table. Irradiating only the chip region with the laser beam to form a first modified layer along the planned dividing line in the chip region, and forming a first modified layer in the outer peripheral surplus region. A first laser processing step as a reinforcing portion;
After performing the holding step, the chip area and the outer peripheral surplus area so as to locate the focal point of the laser beam having a wavelength that is transparent to the glass substrate inside the glass substrate held by the holding table. Irradiating the laser beam along the boundary of, a second laser processing step of forming a second modified layer along the boundary,
An unloading step of unloading the glass substrate from the holding table after performing the first laser processing step and the second laser processing step;
After performing the unloading step, applying a force to the glass substrate to divide the glass substrate into the individual chips,
In the dividing step, a plurality of holding portions respectively hold a plurality of portions of the glass substrate divided by the one or more scheduled dividing lines, and a force for moving the plurality of portions relatively to the plurality of holding portions in a direction away from each other. Wherein the glass substrate is divided into the individual chips by a method of dividing the glass substrate along the plurality of planned dividing lines.   2. The method according to claim 1, further comprising: a step of removing the reinforcing portion after performing the first laser processing step and the second laser processing step and before performing the dividing step. 3. Chip manufacturing method. The upper surface of the holding table is made of a flexible material,
3. The method according to claim 1, wherein in the holding step, the front side of the glass substrate is held by the flexible material.