TWI770324B - The method of dividing the workpiece - Google Patents

Abstract

[Problem] To provide a method for dividing a workpiece, which can prevent the rubbing of the corners of adjacent wafers and prevent the breakage of the wafers. [Solution] A dividing method for dividing a plate-shaped workpiece having a first surface and a second surface into a plurality of wafers, the dividing method comprising: a step of coating a resin layer in which the coating on the first surface is carried out by external The resin is stimulated and hardened and hardened; the frame unit forming step is to form a frame unit, which is formed by attaching the workpiece to the adhesive tape attached to the ring frame through the resin layer; dividing The starting point forming step is to irradiate the laser light with a wavelength that is penetrating to the workpiece of the frame unit from the second surface, so as to form a dividing starting point inside the workpiece; and the cutting step is to separate the second surface of the workpiece. The side is placed on a support base equipped with a cutting device that presses the blade, and the press blade positioned along the dividing starting point presses the workpiece through the adhesive tape and the resin layer, and the workpiece is processed with the dividing starting point as the starting point. Things cut off.

Description

The method of dividing the workpiece

FIELD OF THE INVENTION The present invention relates to a method for dividing a plate-shaped workpiece into a plurality of wafers.

Background of the Invention Generally, an optical element wafer (object to be processed) on which optical elements such as sapphire, SiC (silicon carbide), and glass are formed is divided into individual element wafers. In the case of dividing such a wafer into individual wafers, there is known a method in which a laser beam is irradiated on the wafer to form a cutting starting point inside the wafer, and then a pressing blade edge of a dividing device is The wafer is positioned at the starting point of division, and one side of the wafer is pressed with this pressing blade to divide (also referred to as dicing) the wafer (see, for example, Patent Document 1 and Patent Document 2). Prior Art Documents Patent Documents

Patent Document 1: Japanese Patent Laid-Open No. 2012-146744 Patent Document 2: Japanese Patent Laid-Open No. 2017-073443

SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION However, in the conventional method, when the wafer is cut by the cutting device, the corners on the one side of the adjacent wafers are brought close to each other, which may cause There is a risk of friction between these corners.

The present invention has been made in view of the above, and an object of the present invention is to provide a method for dividing a workpiece, which can prevent the rubbing of the corners of adjacent wafers and prevent the wafers from being damaged. means of solving problems

In order to solve the above-mentioned problems and achieve the object, the present invention is a method for dividing a workpiece, which divides a plate-shaped workpiece having a first surface and a second surface opposite to the first surface into a plurality of pieces. A wafer, the method for dividing the workpiece includes: a resin layer forming step of covering the first surface of the workpiece with a resin that is hardened by an external stimulus, and applying an external stimulus to the covered resin to harden it; a frame unit forming step, to form a frame unit, the frame unit is formed by attaching the workpiece to the adhesive tape whose outer periphery has been attached to the annular frame through the resin layer; forming a division starting point a step of irradiating a laser light of a wavelength having penetrability to the workpiece of the frame unit from the second surface, so as to form a dividing starting point inside the workpiece; and a cutting step, the The second surface side is placed on a support base of a cutting device provided with a pressing blade for cutting, and the pressing blade positioned along the dividing starting point presses the quilt through the adhesive tape and the resin layer. The workpiece is cut with the starting point of division as the starting point, and the cured resin layer prevents the corners of the cut wafer from being rubbed by pressing.

According to this structure, the to-be-processed object can be cut|disconnected by covering the 1st surface which becomes a pressing surface with the resin which hardens by an external stimulus, and after this resin hardening, pressing the resin layer side. Therefore, by bringing the resin layers provided on the adjacent wafers into contact with each other at the time of cutting, the contact of the corner portion on the first surface side in the wafer can be suppressed, and the wafer can be prevented from rubbing against the corner portion. damaged.

In this configuration, the first surface of the workpiece may be provided with concavities and convexities, and the concavities and convexities are structures that serve as constituent elements. According to this configuration, since the resin layer that is hardened by external stimuli is covered with the concavities and convexities, when the workpiece 100 is cut, the hardened resin layer can be pressed by the pressing blade of the cutting device to prevent the concavities and convexities and the pressing. Blade contact while protecting bumps.

In addition, the dividing starting point may be a shielding through hole formed of a thin hole extending from the second surface toward the first surface and an amorphous material shielding the thin hole. According to this configuration, the workpiece can be easily divided into a plurality of wafers by using the shield through hole as the dividing starting point.

Moreover, after this cutting|disconnection process is implemented, you may have a resin removal process which heats and softens this resin, and may remove it from this to-be-processed object. According to this structure, the resin layer hardened by an external stimulus can be easily removed from the 1st surface of a to-be-processed object. Invention effect

According to this invention, the to-be-processed object can be cut|disconnected by coating the resin which hardens by an external stimulus on the 1st surface which becomes a pressing surface, and pressing the resin layer side after this resin hardening. Therefore, when the resin layers provided on the adjacent wafers come into contact with each other at the time of slicing, the contact of the corner portion on the first surface side in the wafer can be suppressed, and the wafer can be prevented from being damaged due to friction of the corner portion. .

MODE FOR CARRYING OUT THE INVENTION The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. In addition, the constituent elements described below include those that can be easily assumed by those skilled in the art or that are substantially the same. In addition, the configurations described below can be appropriately combined. In addition, omissions, substitutions, or changes of various configurations can be made without departing from the gist of the present invention.

FIG. 1 is a perspective view showing a configuration example of a workpiece divided by the method for dividing a workpiece according to the present embodiment. FIG. 2 is a perspective view showing a configuration example of a device wafer formed by dividing the workpiece of FIG. 1 . The workpiece 100 is, for example, an optical element wafer whose base material is glass, sapphire, silicon carbide, or the like, and is a glass substrate in this embodiment. As shown in FIG. 1 , the workpiece 100 is a rectangular plate body including a front surface 100A (first surface) and a back surface 100B (second surface), which is the surface opposite to the front surface 100A. The shape of the workpiece 100 is not limited to a rectangular shape, and may be a circular shape. The device wafer (wafer) 110 shown in FIG. 2 is formed by dividing the workpiece 100 into plural pieces in the X-axis direction and the Y-axis direction which are orthogonal to each other.

The element wafer 110 constitutes an optical element wafer, and as shown in FIG. 2 , is formed in a substantially quadrangular prism shape, and includes a quadrangular pyramid-shaped protrusion 111 on the upper surface side. Specifically, the element wafer 110 includes a rectangular bottom surface 110A, four side surfaces 110B, and four inclined surfaces 110D connecting the side surfaces 110B and the vertex 110C. The quadrangular pyramid-shaped protrusion 111 formed by the vertex 110C and the inclined surface 110D functions as, for example, a lens (structure) constituting the element wafer 110 as an optical element wafer. In addition, in this embodiment, although the protrusion 111 of the device wafer 110 is formed in the quadrangular pyramid shape which has the vertex 110C, it may be formed in the quadrangular truncated pyramid shape which has a flat part.

Next, a division method for dividing the above-mentioned plate-shaped workpiece 100 into element wafers will be described. FIG. 3 is a flowchart showing the procedure of the method of dividing the workpiece. As shown in FIG. 3 , the method for dividing the workpiece 100 includes the following steps: a concavo-convex forming step S1 , a resin layer covering step (resin layer forming step) S2 , a frame unit forming step S3 , a dividing starting point forming step S4 , The cutting step S5 and the resin layer removing step S6 are performed. Next, each of these steps will be described.

[Concavo-convex forming step S1 ] FIG. 4 is a partial cross-sectional view of a configuration example in which concavo-convex portions are formed on the front surface of a workpiece. On the front surface 100A of the workpiece 100 , a concavo-convex portion (concavo-convex) 120 shown in FIG. 4 is formed. In the present embodiment, the concavo-convex portion 120 is formed by a plurality of groove portions 121 juxtaposed with a predetermined interval P in the X-axis direction and the Y-axis direction, respectively. The groove portion 121 is formed in a V-shape with a top portion 121A, a bottom portion 121B, and an inclined surface 121C. The formation of the uneven portion 120 is performed using the cutting unit 10 . The workpiece 100 has a protective tape 101 attached to the back surface 100B, and is held on a holding table (not shown) through the protective tape 101 . The holding table is configured to be rotatable in parallel with the horizontal plane (XY plane), and is provided with a moving mechanism (not shown) that can move in the machining feed direction (X-axis direction) with respect to the cutting unit 10, respectively. ) and a mechanism that moves relatively in the indexing feed direction (Y-axis direction).

The cutting unit 10 includes a cutting blade 13 attached to a rotating spindle 12 that rotates around the axis 11 . The cutting blade 13 is formed in a disk shape, and a ring-shaped cutting blade 14 is provided on the peripheral edge. The cutting blade 14 is a V-shaped blade having a predetermined blade angle θ with respect to the vertical line. In the cutting unit 10, the cutting blade 13 is moved forward and backward freely in the vertical direction (Z-axis direction) with respect to the workpiece 100 by an elevating mechanism (not shown). Therefore, while moving the workpiece 100 (holding table) in the machining feed direction, the cutting blade 13 can be cut into the workpiece 100 to form a V extending in the machining feed direction on the workpiece 100 The groove portion 121 in the shape of a letter. Furthermore, by raising the cutting unit 10 and moving the workpiece 100 (holding table) relative to the cutting blade 13 in the indexing feed direction corresponding to a predetermined interval P, as shown in FIG. 4 , a predetermined Plural grooves 121 are arranged side by side at an interval P. In addition, by rotating the workpiece 100 (holding table) by 90°, and forming a plurality of grooves 121 juxtaposed at a predetermined interval P in this state, the concavo-convex portion ( bump) 120. The top 121A of the uneven portion 120 corresponds to the vertex 110C at the time of dividing into the element wafer 110 . In addition, the shapes of the protrusions 111 and the concavo-convex parts 120 of the element wafer 110 are only examples of the configuration, and are not limited to this configuration, and therefore may be appropriately changed.

[Resin Layer Covering Step S2 ] Next, the front surface 100A side of the workpiece 100 in which the uneven portion 120 is formed is covered with a resin layer. 5 is a partial cross-sectional view of a configuration example in which the concavo-convex portion formed on the front surface of a workpiece is covered with a liquid resin, and FIG. 6 is a partial cross-sectional view of a configuration example in which the coated liquid resin is cured to form a resin layer . The workpiece 100 exposes the concave-convex portion 120 formed on the front surface 100A side by the above-described cutting process. When the workpiece (glass substrate) 100 having the concave-convex portion 120 formed on the front surface 100A is divided (cut) by a dividing device (described later), the concave-convex portion 120 may be damaged by the pressing force of the dividing device. or risk of damage. Therefore, the uneven portion 120 is protected by covering the uneven portion 120 with the resin layer 130 ( FIG. 6 ).

When forming the resin layer 130 , in the present embodiment, the resin supply nozzle 20 is arranged on the uneven portion 120 of the workpiece 100 , and the liquid resin 131 is supplied from the resin supply nozzle 20 . As the liquid resin, a curable resin can be used, and for example, TEMPLOC (registered trademark) manufactured by DENKA Co., Ltd. can be used. This TEMPLOC can be cured in a short time by ultraviolet irradiation (external stimulus), and can be easily removed from the coated object by soaking in warm water without using an organic solvent, so it is very easy to handle.

Furthermore, it is preferable that the workpiece 100 is held on a rotary table (not shown) through the protective tape 101 . The turntable is configured to be able to rotate the workpiece 100 in the circumferential direction while holding the workpiece 100 . The supplied liquid resin 131 is diffused radially outward from the center of the workpiece 100 by the centrifugal force accompanying the rotation of the turntable. Therefore, the grooves 121 formed in the concavo-convex portion 120 of the workpiece 100 can be filled with the liquid resin 131, and the upper surface of the liquid resin 131 covering the concavo-convex portion 120 of the workpiece 100 can be adjusted to be substantially flat. Furthermore, the coating of the concave-convex portion 120 of the workpiece 100 by the liquid resin 131 can be performed by housing the workpiece 100 in a mold frame (not shown) in addition to the coating by the above-mentioned rotary table. , and fill the gap of the mold frame with the liquid resin 131 . Furthermore, in addition to the above, after coating the concave-convex portion 120 with the liquid resin 131, the upper surface of the liquid resin 131 may be pressed with a transparent plate having a flat surface through a transparent release sheet or the like. , so that the upper surface of the liquid resin 131 is substantially flattened. At this time, the transparent release sheet and the transparent plate should be made of materials that allow ultraviolet rays to penetrate.

Next, the liquid resin 131 is hardened to form the resin layer 130 . In the present embodiment, since the TEMPLOC used as the liquid resin 131 has the property of being cured by ultraviolet irradiation (external stimulus), as shown in FIG. The ultraviolet irradiation lamp 21 is arranged on the liquid resin 131 , and the ultraviolet irradiation lamp 21 is irradiated with ultraviolet rays 22 toward the liquid resin 131 . Thereby, the resin layer 130 can be formed by hardening the liquid resin 131 . The surface (upper surface) 130A of this resin layer 130 is formed flat.

[Frame Unit Forming Step S3 ] Next, the frame unit 117 is formed by holding the workpiece 100 on which the resin layer 130 is formed on the annular frame 115 . FIG. 7 is a perspective view showing a configuration example of a frame unit. The frame unit 117 includes an annular frame 115 , an adhesive tape 116 having an outer peripheral edge attached to the annular frame 115 , and a workpiece 100 attached to the adhesive tape 116 . The workpiece 100 is in a state where the protective tape 101 attached to the back surface 100B side is removed to expose the back surface 100B, and the back surface 100B is attached to the adhesive tape 116 with the resin layer 130 interposed therebetween with the back surface 100B facing upward. The annular frame 115 has an opening 115A larger than the workpiece 100, and holds the workpiece 100 in the opening 115A.

[Segmentation starting point forming step S4] Next, a laser light having a wavelength having penetrability to the workpiece 100 of the frame unit 117 is irradiated from the back surface 100B to form a screen guard through hole 140 (the starting point of division) in the workpiece 100 ). 8 is a perspective view showing a configuration example of a laser processing apparatus for forming a shield through hole in a workpiece. 9 is a partial cross-sectional view schematically showing the internal structure of a workpiece in which a shield through hole is formed. FIG. 10 is a cross-sectional view schematically showing the structure of the display screen protection hole, and FIG. 11 is a perspective view schematically showing the structure of the display screen protection hole.

The shield through hole 140 is formed using the laser processing device 30 as shown in FIG. 8 . The laser processing apparatus 30 includes a work clamp 31, a laser irradiation unit 32, and a photographing unit (not shown). The work clamp 31 is a holding frame unit 117, and the laser irradiation unit 32 is used to hold the work clamp. The object to be processed 100 of the frame unit 117 on 31 is irradiated with laser light, and the photographing unit captures the object to be processed 100 . The work jig 31 is configured to attract and hold the frame unit 117 . In addition, the table 31 is configured so as to be rotatable parallel to the horizontal plane (XY plane), and is provided with a moving mechanism (not shown) that can move in the machining feeding direction with respect to the laser irradiation unit 32, respectively. (X-axis direction) and the index feed direction (Y-axis direction) move relatively.

The laser irradiation unit 32 includes an oscillator (not shown) that oscillates and generates laser light, and a condenser 32A that condenses the laser light oscillated by the oscillator. The oscillator can appropriately adjust the frequency of the oscillated laser light according to the processing shape and the like. The condenser 32A is composed of a total reflection mirror or a condenser lens. The total reflection mirror changes the traveling direction of the laser light oscillated by the oscillator. The condenser lens is used for condensing the laser light. . In addition, the laser irradiation unit 32 is provided with a condensing point position adjusting device (not shown) for adjusting the laser light condensed by the condensing lens of the concentrator 32A. Spotlight position. The imaging unit is constituted by an optical device such as a microscope or a CCD camera.

When using the laser processing apparatus 30 to form the shield through-hole 140 in the workpiece 100, first, as shown in FIG. 8, the table 31 holding the frame unit 117 is moved in the processing feed direction, And the to-be-processed object 100 is positioned directly below the imaging unit. Next, the groove portion 121 ( FIG. 4 ) formed in the concavo-convex portion 120 of the workpiece 100 is photographed using an imaging unit to detect whether the groove portion 121 is positioned parallel to the machining feed direction (X-axis direction). At this time, when the groove portion 121 is not parallel to the machining feed direction, the table 31 is rotated and adjusted so that the groove portion 121 is parallel to the machining feed direction.

Next, the work jig 31 is moved below the condenser 32A of the laser irradiation unit 32, and the grooves 121 (for example, located at the outermost edge) arranged side by side at a predetermined interval P in the index feeding direction (Y-axis direction) are moved. The bottom 121B (FIG. 4) of the groove portion 121) is positioned directly below the condenser 32A. Then, as shown in FIG. 9 , the condensing point position adjusting device (not shown) is actuated to move the condenser 32A in the direction of the optical axis to form the laser beam condensed by the condenser lens of the condenser 32A The condensing point Q of the light ray 32B is positioned at a desired position in the thickness direction from the back surface 100B of the workpiece 100 .

As described above, after the condensing point Q of the laser light 32B has been positioned from the back surface 100B of the workpiece 100 to a desired position in the thickness direction, the laser irradiating unit 32 can be activated to irradiate the laser from the concentrator 32A. The light 32B is emitted to form a shielding through hole 140 from the vicinity of the light-converging point Q of the workpiece 100 toward the front surface 100A, wherein the shielding through hole 140 is composed of a pore and an amorphous material that shields the pore. That is, while irradiating the laser beam 32B of the wavelength having penetrability to the workpiece 100 from the condenser 32A along the groove portion 121 ( FIG. 4 ), the table 31 is directed toward the drawing at a predetermined feeding speed. 8 and FIG. 9 are moved in the machining feed direction (X-axis direction).

In addition, when forming the shield through-hole 140, the processing conditions shown next are set. Wavelength: 1030nm Repetition frequency: 40kHz Pulse width: 10ps Average output: 0.5W Spot diameter: φ5μm Processing feed rate: 400mm/sec Numerical aperture of condenser lens: 0.25

As shown in FIG. 10 , inside the workpiece 100 , the pores 141 extending toward the front and the amorphous material 142 formed around the pores 141 are grown from the vicinity of the condensing point Q of the laser beam 32B. , and formed along the region corresponding to the groove portion 121 ( FIG. 4 ) at a predetermined interval (in the illustrated embodiment, the interval is 10 μm (processing feed rate: 400 mm/sec)/(repetition frequency: 40 kHz)) Amorphous shielding vias 140 . As shown in FIG. 11 , the shield through hole 140 is composed of a fine hole 141 with a diameter d1 of about φ1 μm formed in the center and an amorphous material 142 formed around the fine hole 141 with a diameter d2 of φ10 μm. In the embodiment, as shown in FIG. 10 , the amorphous materials 142 adjacent to each other are connected so as to be connected to each other.

In this way, if the shield through hole 140 is formed along the area corresponding to the groove portion 121 ( FIG. 4 ), the table 31 can be moved in the index feeding direction by an amount corresponding to the interval P of the groove portion 121 . distance, and the shield through hole 140 is formed along the area corresponding to the groove portion 121 . After the shield through holes 140 are formed along the regions corresponding to all the grooves 121 formed in the predetermined direction in this way, the table 31 can be rotated by 90°, and the through holes 140 can be formed along the regions corresponding to the grooves 121. The shield through hole 140 is formed in which the groove portion 121 is a groove portion 121 formed in a direction orthogonal to the groove portion 121 formed in the above-mentioned predetermined direction.

[Cut-off step S5 ] Next, an external force is applied to the workpiece 100 to break the workpiece 100 along the grooves 121 of the uneven portion 120 . 12 is a partial cross-sectional view schematically showing a state in which a workpiece having a shield through hole formed therein is cut. In this FIG. 12, the state in which the to-be-processed object 100 is cut is exaggeratedly drawn. The cutting of the workpiece 100 is performed using the cutting device 40 shown in FIG. 12 . The cutting device 40 includes a support table 41 for supporting the workpiece 100 and a pressing blade 42 , and the pressing blade 42 moves up and down relative to the support table 41 to face the workpiece 100 supported by the support table 41 . Give pressing pressure. The support stand 41 is configured to be rotatable parallel to the horizontal plane, and an opening 41A is formed just below the pressing blade 42 . The workpiece 100 is placed on the support table 41 through the protective sheet 108 attached to the back surface 100B side. At this time, as shown in FIG. 12 , the shielding through hole 140 formed in the region corresponding to the groove portion 121 is positioned so as to be positioned in the opening portion 41A of the support base 41 . Then, the pressing blade 42 is pressed along the groove portion 121 from the adhesive tape 116 side attached to the resin layer 130 covering the uneven portion 120 on the front surface 100A side of the workpiece 100 . As a result, a bending load acts on the workpiece 100 along the shielding through hole 140 formed in the region corresponding to the groove portion 121 , so that the shielding through hole 100B exposed on the back surface 100B of the workpiece 100 is applied. A tensile load is generated on the side of the hole 140 . Therefore, as shown in FIG. 12 , the workpiece 100 is cut along the groove portion 121 with the shield through hole 140 formed in the region corresponding to the groove portion 121 as the starting point of division.

Then, after cutting the workpiece 100 along the shield through holes 140 formed in the region corresponding to the groove portion 121 in the predetermined direction, the support table 41 is rotated 90° so as to be in the direction perpendicular to the predetermined direction. The above-mentioned cutting operation is performed on the shielding through holes 140 formed in the regions corresponding to the grooves 121 extending in the intersecting direction. Thereby, the workpiece 100 can be divided into individual element wafers 110 .

In the present embodiment, since the resin layer 130 covering the concavo-convex portion 120 formed on the front surface 100A of the workpiece 100 is provided, it is possible to press the workpiece 100 by the pressing blade 42 of the cutting device 40 when cutting the workpiece 100 The resin layer 130 prevents the concave-convex portion 120 from contacting the pressing blade 42 and protects the concave-convex portion 120 . In addition, when the workpiece 100 is cut, the resin layers 130 provided on the adjacent element wafers 110 are brought into contact with each other. Therefore, the contact of the corner portion on the front surface 100A side of the element wafer 110 can be suppressed, and the element wafer 110 can be prevented from being damaged due to friction of the corner portion.

[Resin Layer Removal Step S6 ] Next, the resin layer 130 is removed. FIG. 13 is a partial cross-sectional view of a configuration example in which a resin layer is removed from a workpiece. FIG. 14 is a partial cross-sectional view of a configuration example of an element wafer from which the resin layer has been removed. In the present embodiment, the TEMPLOC used as the resin layer 130 has the characteristic of being detached from the workpiece 100 , which is the object to be covered, by being immersed in warm water (eg, 80 to 90° C.). Therefore, as shown in FIG. 13 , after peeling off the adhesive tape 116 attached to the resin layer 130 , the cut workpiece 100 is put into a water tank (not shown) containing warm water 50 . Thereby, since the resin layer 130 can be softened by heating, it can be easily removed from the workpiece 100 . Thereby, as shown in FIG. 14, the element wafer 110 divided into each can be obtained. Furthermore, since these element wafers 110 are integrated by the protective sheet 108, it is possible to prevent the case where the element wafers 110 are scattered in a disorderly manner.

Next, another embodiment will be described. In the above-mentioned embodiment, in the step S4 of forming the starting point of division, the structure in which the shield through hole 140 is formed inside the workpiece 100 as the starting point of division has been described, but the modified layer 150 may also be formed as the starting point of division. . 15 is a partial cross-sectional view schematically showing the internal structure of a workpiece on which a modified layer is formed, and FIG. 16 is a partial cross-sectional view schematically showing a state in which the modified layer-formed workpiece is cut. Also in this FIG. 16, the state in which the to-be-processed object 100 is cut is exaggeratedly drawn. Contents that are the same as those of the above-mentioned division starting point forming step S4 and dividing step S6 are assigned the same reference numerals, and descriptions thereof will be omitted.

As shown in FIG. 15 , the laser processing apparatus 30 irradiates the laser beam 32B with a wavelength having penetrability from the back surface 100B side of the workpiece 100 to form a modified layer 150 inside the workpiece 100 . The modified layer refers to a region in which density, refractive index, mechanical strength, or other physical properties are different from those of the surrounding base material, and may be, for example, a molten region, a cracked region, a dielectric breakdown region, a refractive index change region, and a mixed region. areas of these areas.

In the same way as in the case of forming the above-mentioned screen guard through hole 140, the work jig 31 is moved to the lower side of the condenser 32A of the laser irradiation unit 32, and is moved at predetermined intervals in the indexing feed direction (Y-axis direction). Bottoms 121B ( FIG. 4 ) of the grooves 121 (for example, the grooves 121 located at the outermost edge) arranged in parallel are positioned directly below the condenser 32A. Then, as shown in FIG. 15 , the condensing point position adjustment device (not shown) is actuated to move the condenser 32A in the direction of the optical axis to form a laser beam condensed by the condenser lens of the condenser 32A The condensing point of the light ray 32B is positioned inside the workpiece 100 .

When the condensing point of the laser light 32B is positioned inside the workpiece 100 in the thickness direction, the laser irradiation unit 32 is actuated to irradiate the laser light 32B from the condenser 32A to the inside of the workpiece 100 . The modified layer 150 is formed. That is, while irradiating the laser beam 32B of the wavelength having penetrability to the workpiece 100 from the condenser 32A along the groove portion 121 ( FIG. 4 ), the table 31 is directed toward the drawing at a predetermined feeding speed. 15 is moved in the machining feed direction (X-axis direction). Thereby, the modified layer 150 can be formed along the region corresponding to the groove portion 121 ( FIG. 4 ) in the workpiece 100 . The modified layer 150 is formed along the entire region corresponding to the groove portion 121 . In addition, in the present embodiment, the modified layer 150 is described as an example in which one layer (one layer) is formed in the thickness direction of the workpiece 100, but a plurality of layers (a plurality of layers) are formed in the thickness direction. You can also.

Next, an external force is applied to the workpiece 100 to cut the workpiece 100 along the grooves 121 of the uneven portion 120 . As shown in FIG. 16 , the workpiece 100 is placed so that the shield through hole 140 formed in the region corresponding to the groove portion 121 is positioned on the opening portion 41A of the support table 41 of the breaking device 40 . Then, the pressing blade 42 is pressed along the groove portion 121 from the adhesive tape 116 side attached to the resin layer 130 covering the uneven portion 120 on the front surface 100A side of the workpiece 100 . As a result, the bending load acts on the workpiece 100 along the modified layer 150 formed in the region corresponding to the groove portion 121 to generate a tensile load on the back surface 100B side of the workpiece 100 . Therefore, as shown in FIG. 16 , cracks can be generated in the thickness direction from the modified layer 150 formed in the region corresponding to the groove portion 121 , and this modified layer 150 serves as a dividing starting point to cut the workpiece 100 along the groove portion 121 . Then, when the workpiece 100 is cut along the modified layers 150 formed in the regions corresponding to all the grooves 121 , the workpiece 100 can be divided into individual element wafers 110 .

Also in this other embodiment, since the resin layer 130 to cover the concave-convex portion 120 formed on the front surface 100A of the workpiece 100 is provided, it is possible to press the cutting device 40 when the workpiece 100 is cut. The blade 42 presses the resin layer 130 to prevent the concave-convex portion 120 from contacting the pressing blade 42 and protect the concave-convex portion 120 . In addition, when the workpiece 100 is cut, the resin layers 130 provided on the adjacent element wafers 110 are brought into contact with each other. Therefore, the contact of the corner portion on the front surface 100A side of the element wafer 110 can be suppressed, and the element wafer 110 can be prevented from being damaged due to friction of the corner portion.

Furthermore, in the above-described embodiment, the starting point of division is set as the shielding through hole formed of the fine hole 141 and the amorphous material 142 that shields the fine hole 141 extending from the back surface 100B toward the front surface 100A of the workpiece 100 140, so the workpiece 100 can be easily divided into the element wafers 110.

Furthermore, in the above-described embodiment, since the resin removal step S6 is provided for heating the resin layer 130 to soften and remove it from the workpiece 100 after the cutting step S5 is performed, the resin layer 130 can be easily removed.

As mentioned above, although one Embodiment of this invention was described, the said embodiment is an embodiment shown as an example, Comprising: It does not intend to limit the scope of the invention. For example, in the above-mentioned embodiment, as the liquid resin, it is hardened in a short time by ultraviolet irradiation (external stimulus), and further softened by soaking in warm water. The material to be removed from the coating object is not limited to this, and a thermoplastic adhesive (wax) that is fixed by cooling as an external stimulus and softened by heating can also be used. In addition to the above, an adhesive tape with a stronger adhesive force than the adhesive force between the resin layer 130 and the workpiece 100 can also be used, so that the resin layer 130 can be peeled off when the adhesive tape attached to the resin layer 130 is peeled off. peeled from the workpiece 100 .

10‧‧‧Cutting Unit 11‧‧‧Shaft 12‧‧‧Rotating Spindle 13‧‧‧Cutting Blade 14‧‧‧Cutting Blade 20‧‧‧Resin Supply Nozzle 21‧‧‧Ultraviolet Irradiation Lamp 22‧‧‧Ultraviolet ( External stimuli) 30‧‧‧Laser processing device 31‧‧‧Working table 32‧‧‧Laser irradiation unit 32A‧‧‧Concentrator 32B‧‧‧Laser light 40‧‧‧breaking device41‧ ‧‧Support stand 41A‧‧‧Opening part 42‧‧‧Pressing blade 50‧‧‧Hot water 100‧‧‧Workpiece 100A‧‧‧Front (1st side) 100B‧‧‧Back side (2nd side) 101 ‧‧‧Protective tape 108‧‧‧Protective sheet 110‧‧‧Component chip (chip) 110A‧‧‧Bottom surface 110B‧‧‧Side surface 110C‧‧‧Top 110D, 121C‧‧‧Inclined surface 111‧‧‧Protrusion 115‧‧‧Ring frame 115A‧‧‧Opening 116‧‧‧Adhesive tape 117‧‧‧Frame unit 120‧‧‧Concave-convex part (concave-convex) 121‧‧‧Groove part 121A‧‧‧Top 121B‧‧‧Bottom 130‧ ‧‧Resin layer 130A‧‧‧Surface (upper surface) of resin layer 131‧‧‧Liquid resin (resin) 140‧‧‧Screen protection through hole (dividing starting point) 141‧‧‧Fine hole 142‧‧‧Amorphous Quality 150‧‧‧modified layer (splitting starting point) d1, d2‧‧‧diameter S1~S6‧‧‧step P‧‧‧interval Q‧‧‧focusing point θ‧‧‧blade angle X, Y, Z‧ ‧‧direction

FIG. 1 is a perspective view showing a configuration example of a workpiece divided by the method for dividing a workpiece according to the present embodiment. FIG. 2 is a perspective view showing a configuration example of an element wafer formed by dividing the workpiece of FIG. 1 . FIG. 3 is a flowchart showing the procedure of the method of dividing the workpiece. 4 is a partial cross-sectional view of an example of a configuration in which uneven portions are formed on the front surface of a workpiece. 5 is a partial cross-sectional view of an example of a configuration in which a concavo-convex portion formed on the front surface of a workpiece is covered with a liquid resin. 6 is a partial cross-sectional view of an example of a configuration in which the coated liquid resin is cured to form a resin layer. FIG. 7 is a perspective view showing a configuration example of a frame unit. 8 is a perspective view showing a configuration example of a laser processing apparatus for forming a shield through hole in a workpiece. 9 is a partial cross-sectional view schematically showing the internal structure of a workpiece in which a shield through hole is formed. FIG. 10 is a cross-sectional view schematically showing the structure of a display screen guard through hole. FIG. 11 is a perspective view schematically showing the structure of a display screen guard hole. 12 is a partial cross-sectional view schematically showing a state in which a workpiece having a shield through hole formed therein is cut. FIG. 13 is a partial cross-sectional view of a configuration example in which a resin layer is removed from a workpiece. FIG. 14 is a partial cross-sectional view of a configuration example of an element wafer from which the resin layer has been removed. FIG. 15 is a partial cross-sectional view schematically showing the internal structure of a workpiece on which a modified layer is formed. 16 is a partial cross-sectional view schematically showing a state in which the workpiece on which the modified layer has been formed is cut.

Steps S1~S6‧‧‧

Claims (5)

A method for dividing a workpiece, comprising dividing a plate-shaped workpiece having a first surface and a second surface opposite to the first surface into a plurality of wafers, the method for dividing the workpiece comprising: a resin a layer forming step, covering the first surface of the workpiece with a resin that can be cured by external stimuli, and applying external stimuli to the covered resin to harden it; a frame unit forming step, forming a frame unit , the frame unit is formed by attaching the object to be processed on the adhesive tape whose outer periphery has been attached to the ring-shaped frame through the resin layer; in the step of forming the starting point of division, irradiating the frame unit from the second surface The workpiece has a penetrating wavelength of laser light, so as to form a starting point of division inside the workpiece; and in a cutting step, the second surface side of the workpiece is placed on a The support base of the cutting device for pressing the cutting edge, and the pressing cutting edge positioned along the starting point of the splitting is used to press the workpiece through the adhesive tape and the resin layer, and the starting point of the splitting is used as the starting point. The workpiece is cut, and the hardened resin layer prevents the rubbing of the corners of the cut wafer by pressing. The method for dividing a workpiece according to claim 1, wherein the first surface of the workpiece is provided with concavities and convexities, and the concavities and convexities are structures constituting elements. The method for dividing a workpiece according to claim 1 or 2, wherein the dividing starting point is a screen-protecting through hole formed of pores extending from the second surface toward the first surface and an amorphous material that shields the pores. The method for dividing a workpiece according to claim 1 or 2, comprising a resin removal step of heating the resin to It is softened and removed from the workpiece. The method for dividing a workpiece according to claim 3, comprising a resin removal step of removing the resin from the workpiece by heating it to soften it after the cutting step is performed.

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