JP6894692B2 - How to divide the glass plate and how to divide the plate-shaped work - Google Patents

Description

The present invention relates to a method for dividing a glass plate and a method for dividing a plate-shaped workpiece composed of a glass plate and a semiconductor wafer.

For chip packages such as image sensors and camera modules, for example, a silicon wafer in which a wafer formed with CMOS and a wafer formed with a logic IC are bonded with an oxide film is further bonded to a glass plate with an appropriate adhesive. A plate-shaped work is formed, and the plate-shaped work is produced by dividing the plate-shaped work along a planned division line of a silicon wafer (see, for example, Patent Document 1). The glass plate preferably has a certain thickness in order to facilitate attachment to the wafer on which the device is formed, but on the other hand, it needs to be thinned as a measure against heat of the chip.

Japanese Unexamined Patent Publication No. 2014-168790 Japanese Unexamined Patent Publication No. 2016-164908

When dividing the silicon wafer and the glass plate along the planned division line of the wafer, for example, a division starting point is formed in advance on the silicon wafer and the glass plate, and an external force is applied to the division starting point to crack the crack in the thickness direction. It is stretched and divided. However, the glass plate often has chipping or chipping on the surface of the glass plate, that is, the outer peripheral portion of the surface of the divided and produced glass chip, which is a problem. Further, for example, when a rotating cutting blade is cut into the glass plate until the glass plate is completely cut to perform division, the glass plate is a hard and difficult-to-cut material, so that a long processing time is required.

Therefore, when the glass plate is divided, there is a problem that the glass plate is divided while suppressing the occurrence of chipping and chipping.

The present invention for solving the above problems, the bonded plate workpiece the surface and one surface of the glass plate of the semiconductor wafer in which the devices are formed in the regions partitioned by the division lines on the surface of the resin It is a method of dividing a plate-shaped work that divides along a planned division line to form a chip, and irradiates a pulsed laser beam having a wavelength that is transparent to the glass plate from the other surface side of the glass plate to glass. A glass plate division starting point having pores condensing inside the plate and extending in the thickness direction of the glass plate and amorphous surrounding the pores is linear inside the glass plate along the planned division line. After the glass plate division starting point forming step and the glass plate dividing starting point forming step, a cutting blade having a V-shaped tip is cut into the other surface of the glass plate along the glass plate dividing starting point. No The V-groove forming step of forming a V-groove along the starting point of dividing the glass plate and the pulse laser beam having a wavelength that is transparent to the semiconductor wafer are irradiated from the surface side on which the glass plate is not adhered to the semiconductor wafer. A semiconductor waiha and glass by applying an external force to the waha division starting point forming step of condensing the inside and forming a modified layer to be the waha division starting point along the planned division line, and the glass plate dividing starting point and the waha dividing starting point. A protective film forming is provided, comprising a dividing step of dividing the plate along the planned division line to form a chip, and forming a protective film for protecting the other surface of the glass plate before the glass plate dividing starting point forming step. comprising the step, the protective film formed by the protective layer forming step is a said V groove forming step you remove the cutting water supplied to the cutting blade plate workpiece splitting method.

In the method for dividing a plate-shaped work according to the present invention, a pulsed laser beam having a wavelength that is transparent to the glass plate is irradiated from the other surface side of the glass plate and condensed inside the glass plate in the thickness direction of the glass plate. A glass plate division starting point forming step of forming a glass plate dividing starting point having pores extending to the glass plate and an amorphous glass surrounding the pores by arranging them linearly inside the glass plate along a planned division line, and glass. After the plate division starting point forming step, a cutting blade having a V-shaped tip is cut into the other surface of the glass plate along the glass plate dividing starting point to form a V groove along the glass plate dividing starting point. Process and modification that irradiates a pulsed laser beam with a wavelength that is transparent to the semiconductor wafer from the surface side where the glass plate is not adhered , condenses it inside the semiconductor wafer, and serves as the waiha division starting point along the planned division line. The process of forming the waiha division starting point for forming the quality layer and the dividing step of applying an external force to the glass plate dividing starting point and the waha dividing starting point to divide the semiconductor wafer and the glass plate along the planned division line to form a chip. A protective film forming step for forming a protective film that protects the other surface of the glass plate is provided before the glass plate division starting point forming step, and the protective film formed in the protective film forming step is cut in the V groove forming step. Since it is removed by the cutting water supplied to the blade, it is possible to prevent chipping and chipping mainly on the outer peripheral portion of the divided and manufactured device chip on the glass plate surface side by the V groove. At the same time, in the step of forming the starting point for dividing the glass plate, even when the glass plate is irradiated with a pulsed laser beam and debris is generated, the adhesion to the glass plate can be prevented by the protective film. Further, the protective film to which debris has adhered can be efficiently removed together with the debris with the cutting water supplied to the cutting blade in the V-groove forming step.

It is sectional drawing which shows an example of the plate-shaped work which was formed by adhering a semiconductor wafer and a glass plate with resin. It is sectional drawing which shows the state which formed the water-soluble protective film on the other surface of the glass plate of a plate-shaped work. FIG. 5 is a cross-sectional view showing a state in which a plate-shaped work is irradiated with a pulsed laser beam and the starting points for dividing the glass plate are arranged inside the glass plate along a planned division line. It is explanatory drawing when the plate-shaped work which is formed so that the glass plate division start point is arranged inside the glass plate along the division schedule line is seen from above. It is sectional drawing which shows the state which formed the V groove along the glass plate division origin on the other surface of a glass plate. It is sectional drawing which shows an example of the plate-shaped work in the state supported by an annular frame. It is sectional drawing which shows the state which formed the modified layer which becomes the origin of a wafer division with respect to the semiconductor wafer along the planned division line. It is sectional drawing which shows the state which applies an external force to the glass plate division start point and the wafer division start point, divides a semiconductor wafer and a glass plate along a planned division line, and manufactures a chip from a plate-shaped work.

The plate-shaped work W having a disk-shaped outer shape shown in FIG. 1 is formed by bonding the surface W1a of the semiconductor wafer W1 and one surface W2b of the glass plate W2 with a resin J. The semiconductor wafer W1 is, for example, a silicon wafer having a disk-shaped outer shape, and a plurality of devices D are formed on a surface W1a of the semiconductor wafer W1 in a grid-like region partitioned by a planned division line S. For example, a protective member (not shown) is attached to the back surface W1b of the semiconductor wafer W1, and the back surface W1b is protected by the protective member. The glass plate W2 has a disk-like outer shape and has an outer diameter equivalent to that of the semiconductor wafer W1, and the other surface W2a, which is the surface opposite to one surface W2b of the glass plate W2, is exposed in the + Z direction. doing.
Hereinafter, each step in the case of dividing the glass plate W2 and dividing the plate-shaped work W by carrying out the method for dividing the glass plate according to the present invention and the method for dividing the plate-shaped work according to the present invention will be described. To go.

(1) Protective film forming step For example, the protective film forming means 2 shown in FIG. 2 forms a water-soluble protective film on the other surface W2a of the glass plate W2 of the plate-shaped work W. The protective film forming means 2 shown in FIG. 2 is, for example, a spin coater (rotary coating device), and is a chuck capable of sucking and holding the plate-shaped work W on the holding surface 20a and rotating around the axis in the Z-axis direction. A table 20, a nozzle 21 for supplying a water-soluble protective film agent to the other surface W2a of the glass plate W2, and a water-soluble protective film agent supplying means 22 for supplying the water-soluble protective film agent to the nozzle 21 are provided. The chuck table 20 is surrounded by a case (not shown) so that the water-soluble protective film agent does not scatter to the surroundings during the formation of the protective film. The water-soluble protective film agent supplied to the nozzle 21 by the water-soluble protective film agent supply means 22 is, for example, HogoMax manufactured by DISCO Corporation.

A plate-shaped work W is placed on the chuck table 20 shown in FIG. 2 so that the other surface W2a side of the glass plate W2 faces up, and a suction means (not shown) connected to the chuck table 20 is operated to act as a holding surface. The plate-shaped work W is sucked and held on 20a. Next, a predetermined amount of the water-soluble protective film agent is dropped from the nozzle 21 onto the center of the other surface W2a of the plate-shaped work W sucked and held on the chuck table 20, and the chuck table 20 is rotated at a predetermined speed. As a result, the dropped water-soluble protective film agent flows from the center of the other surface W2a of the glass plate W2 toward the outer peripheral side by centrifugal force, and spreads over the entire surface of the other surface W2a of the glass plate W2, which is almost uniform. A protective film G having a large thickness is formed on the other surface W2a of the glass plate W2. After that, the rotation is continued to rotate and dry the protective film G. Further, if necessary, the protective film G is cured by baking, for example.

(2) Holding Step The plate-shaped work W on which the protective film G is formed on the other surface W2a of the glass plate W2 is conveyed to the laser processing apparatus 4 shown in FIG. The laser processing apparatus 4 includes, for example, a chuck table 40 that sucks and holds the plate-shaped work W, a pulse laser beam irradiating means 41 that irradiates the plate-shaped work W held by the chuck table 40 with a pulsed laser beam, and the like. At least have. The chuck table 40 schematically shown in FIG. 3 sucks and holds the plate-shaped work W on a holding surface made of, for example, a porous member or the like. The chuck table 40 can rotate around the axis in the vertical direction (Z-axis direction) and can reciprocate in the X-axis direction.

The pulse laser beam irradiating means 41 causes the pulsed laser beam oscillated from the pulse laser beam oscillating means 410 to enter the condensing lens 411a inside the condensing device 411 via a transmission optical system such as an optical fiber. The concentrator 411 can accurately condense the pulsed laser beam while adjusting the position of the plate-shaped work W held by the chuck table 40 at a predetermined position. The pulse laser beam oscillating means 410 is set by adjusting, for example, the repetition frequency, pulse width, and wavelength of the pulse laser beam oscillator 410a such as a YAG laser or YVO4 laser and the pulse laser beam oscillated by the pulse laser beam oscillator 410a. It is provided with a setting unit 410b that can be used.

In the vicinity of the pulsed laser beam irradiating means 41, an alignment means 44 for detecting the scheduled division line S of the plate-shaped work W held on the chuck table 40 is arranged. The alignment means 44 includes an image pickup means 440 that images the surface W1a of the semiconductor wafer W1, and is scheduled to be divided as a reference line when irradiating the pulse laser beam of the plate-shaped work W based on the image acquired by the image pickup means 440. Line S can be detected. The alignment means 44 and the pulse laser beam irradiation means 41 are integrally formed, and both move in the Y-axis direction and the Z-axis direction in conjunction with each other.

As shown in FIG. 3, the plate-shaped work W is placed on the holding surface of the chuck table 40 with the back surface W1b side of the semiconductor wafer W1 facing down. Then, the suction force generated by the suction source (not shown) is transmitted to the holding surface of the chuck table 40, so that the other surface W2a of the glass plate W2 is exposed upward, that is, one of the glass plates W2. The plate-shaped work W is sucked and held by the chuck table 40 while the surface W2b side is held. In addition, you may start from this holding step without carrying out the said (1) protective film forming step.

(3) Glass plate division starting point forming step The plate-shaped work W held on the chuck table 40 is sent in the −X direction (forward direction, for example, the direction toward the front side of the paper surface), and the protective film G and the glass are formed by the imaging means 440. The scheduled division line S formed on the surface W1a of the semiconductor wafer W1 through the plate W2 is detected. Based on the image of the scheduled division line S captured by the imaging means 440, the alignment means 44 executes image processing such as pattern matching to detect the position of the scheduled division line S. As the scheduled division line S is detected, the pulsed laser beam irradiating means 41 is driven in the Y-axis direction, and the Y-axis direction of the scheduled split line S serving as a reference for irradiating the pulsed laser beam and the condenser 411. Is aligned in. This alignment is performed so that, for example, the center line of the scheduled division line S is located directly below the condenser lens 411a provided in the condenser 411.

Next, the setting unit 410b makes adjustments so that the pulsed laser beam oscillator 410a can oscillate a pulsed laser beam having a wavelength (for example, a wavelength in the visible light region) that is transparent to the glass plate W2. Further, in the condenser 411, the focusing point of the pulsed laser beam having transparency with respect to the glass plate W2 is set at a predetermined height position inside the glass plate W2 corresponding to the scheduled division line S, that is, for example. It is positioned at a height position slightly above one surface W2b of the glass plate W2. Further, the setting unit 410b sets the repetition frequency and the pulse width of the pulsed laser beam oscillated by the pulsed laser beam oscillator 410a to arbitrary values.

Then, while irradiating the glass plate W2 with the pulsed laser beam oscillated from the pulse laser beam oscillator 410a and condensed by the condensing lens 411a from the other surface W2a side of the glass plate W2 along the scheduled division line S. , The chuck table 40 is machined and fed in the −X direction at a predetermined machining feed rate, and as shown in FIG. 3, the pores M1a and the pores M1a extending in the thickness direction (Z-axis direction) are formed inside the glass plate W2. A glass plate division starting point M1 including the surrounding amorphous M1b is formed. The pores M1a extend slightly in a tunnel shape from the condensing point in the −Z direction due to the evaporation of the glass plate W2 around the condensing point of the pulsed laser beam, and in the + Z direction from the condensing point. It extends long like a tunnel toward. Further, the amorphous M1b is formed so as to surround the pores M1a as the pores M1a grow.

For example, the condensing point of the pulsed laser beam having transparency to the glass plate W2 is positioned near the other surface W2a of the glass plate W2 corresponding to the scheduled division line S, and the glass plate division starting point is set from the condensing point. When laser processing is performed so as to extend long in the −Z direction, debris (for example, oxide derived from glass plate W2) is continuously generated and scattered near the condensing point to form a glass plate division starting point. Debris adheres to the device chip after the plate-shaped work W is divided, which causes a problem that the quality of the device chip deteriorates. In addition, there is a problem that the glass plate division starting point M1 is formed so that the pores M1a are not arranged and are uneven in the horizontal plane direction. On the other hand, as shown in FIG. 3, the glass plate is divided until the upper end side of the glass plate division starting point M1 reaches a predetermined height position inside the glass plate W2 which does not open on the other surface W2a of the glass plate W2. By forming the starting point M1 so as to extend long in the + Z direction, debris does not occur or scatter on the other surface W2a of the glass plate W2. Therefore, debris of the device chip produced by dividing the plate-shaped work W The problem of quality deterioration due to adhesion does not occur, and the formed pores M1a of the glass plate division starting point M1 also have a linearly arranged shape. In the case where (1) the protective film forming step is carried out to form the water-soluble protective film G on the other surface W2a of the glass plate W2 of the plate-shaped work W as in the present embodiment, the case where the water-soluble protective film G is formed. The glass plate division starting point M1 may be extended and formed until the upper end side of the glass plate dividing starting point M1 opens on the other surface W2a of the glass plate W2.

When the glass plate W2 is suddenly irradiated with a continuously oscillating laser beam having a high power density, a large amount of the glass plate W2 is instantly melted and evaporated, so that a large irregular glass plate division starting point M1 is formed. By the controlled pulse oscillation, as shown in FIG. 4, the glass plate division starting point M1 is set on the glass plate W2 by providing a fine predetermined interval in the X-axis direction along the planned division line S from the −X direction to the + X direction. It can be formed by arranging them in a straight line inside. In the present embodiment, the amorphous M1b shown in FIG. 3 adjacent to each other is formed so as to be connected to each other.

As shown in FIG. 3, a glass plate division starting point M1 is continuously formed inside the glass plate W2 along the center line of the planned division line S, and for example, one scheduled division line S is irradiated with a pulse laser beam. The plate-shaped work W is advanced in the −X direction to a predetermined position in the X-axis direction to be completed. Next, the irradiation of the pulsed laser beam is stopped, the machining feed of the plate-shaped work W in the −X direction (forward direction) is stopped once, and the pulsed laser beam irradiating means 41 is moved in the + Y direction to generate the pulsed laser beam. The scheduled division line S located next to the irradiated scheduled division line S and not yet irradiated with the pulsed laser beam and the condenser 411 are aligned in the Y-axis direction. Next, the plate-shaped work W is processed and fed in the + X direction (return direction), and the pulsed laser beam is irradiated to the scheduled division line S in the same manner as the irradiation of the pulsed laser beam in the forward direction. By sequentially irradiating the same pulsed laser beam, the pulsed laser beam is irradiated from the other surface W2a side of the glass plate W2 along all the scheduled division lines S extending in the X-axis direction, and the inside of the glass plate W2 is irradiated. The glass plate division starting point M1 is formed.

By sequentially irradiating the same pulsed laser beam, the pulsed laser beam is irradiated along all the scheduled division lines S extending in the X-axis direction, and the glass plate division starting point M1 is formed along the scheduled division line S. I will go. Further, when the chuck table 40 is rotated 90 degrees and then the same pulse laser beam is irradiated, the glass plate division starting point M1 is formed along all the vertical and horizontal division scheduled lines S. The plate-shaped work W on which the glass plate division starting point M1 is formed is conveyed to the cutting device 6 shown in FIG.

(4) V-Groove Forming Step The cutting device 6 shown in FIG. 5 is, for example, a cutting blade that cuts into a chuck table 65 that holds a plate-shaped work W and a glass plate W2 of the plate-shaped work W that is held on the chuck table 65. At the cutting means 64 provided with 640, the alignment means 63 for detecting the glass plate division starting point M1 of the plate-shaped work W held on the chuck table 65, and the machining point where the cutting blade 640 contacts the glass plate W2. It is provided with a cutting water supply nozzle 62 for supplying cutting water.

The alignment means 63 includes an image pickup means 630 that images the other surface W2a of the glass plate W2, and based on the image acquired by the image pickup means 630, the glass plate division starting point M1 to which the cutting blade 640 should be cut is a plurality of straight lines. Detects lines that are arranged in a shape. The chuck table 65 schematically shown in FIG. 5 can suck and hold the plate-shaped work W on a holding surface made of, for example, a porous member, and can rotate around the axis in the vertical direction (Z-axis direction). It can be reciprocated in the X-axis direction.

The cutting blade 640 is, for example, a hub blade, and includes a disc-shaped base 640a and a cutting blade 640b fixed to the outer peripheral portion of the base 640a. The cutting blade 640b serves as the tip of the cutting blade 640, has an acute-angled shape, and has a V-shaped cross section. Then, the cutting blade 640 is rotatably mounted on the spindle 641 provided in the cutting means 64 and whose axial direction is orthogonal to the X-axis direction in the horizontal direction (Y-axis direction), and the spindle 641 is rotatably mounted by a motor (not shown). The cutting blade 640 also rotates at high speed as it is rotationally driven. The cutting blade 640 is not limited to the hub blade, and may be a washer-type blade having an annular outer shape as long as the tip is sharp and the cross-sectional shape is V-shaped.

For example, two cutting water supply nozzles 62 are arranged so as to sandwich the cutting blade 640 from both sides in the Y-axis direction, and the cutting water supply nozzle 62 is provided with an injection port facing the side surface of the cutting blade 640. Communicating. The cutting means 64, the alignment means 63, and the cutting water supply nozzle 62 move in conjunction with each other in the Y-axis direction and the Z-axis direction.

The plate-shaped work W is placed on the holding surface of the chuck table 65 with the back surface W1b side of the semiconductor wafer W1 facing down. Then, the suction force generated by the suction source (not shown) is transmitted to the holding surface of the chuck table 65, so that the plate-shaped work W is exposed to the chuck table 65 while the other surface W2a of the glass plate W2 is exposed upward. Is sucked and held by.

The chuck table 65 that sucks and holds the plate-shaped work W is sent in the −X direction, and the glass plate W2 is imaged through the protective film G by the imaging means 630 to divide the glass plate into which the cutting blade 640 should be cut. A line composed of a plurality of starting points M1 arranged linearly in the X-axis direction is detected. As the line consisting of the glass plate dividing starting point M1 is detected, the cutting means 64 is indexed and fed in the Y-axis direction, and the line extending in the X-axis direction consisting of the glass plate dividing starting point M1 to be cut and the cutting blade 640 Is aligned in the Y-axis direction.

Next, the cutting means 64 descends in the −Z direction, and for example, the cutting means 64 is positioned at a height position at which the lowermost end of the cutting blade 640b of the cutting blade 640 cuts slightly toward the upper end side of the glass plate division starting point M1. .. The chuck table 65 holding the plate-shaped work W is further fed in the −X direction at a predetermined cutting feed rate, a motor (not shown) rotates the spindle 641 at a high speed, and a cutting blade 640 fixed to the spindle 641 is a spindle 641. By rotating at high speed with the rotation, the cutting blade 640 cuts into the protective film G and the other surface W2a of the glass plate W2 along the glass plate division starting point M1. Then, along the glass plate division starting point M1 linearly arranged in the X-axis direction, for example, the deepest portion of the groove is located slightly below the upper end of the glass plate dividing starting point M1 in the −Z direction, and the cross section is V. A V-groove VM having a shape is formed on the other surface W2a of the glass plate W2. The depth of the V-groove VM is not limited to the depth in the present embodiment, and may be at least a depth at which the V-groove VM and the glass plate division starting point M1 are connected. When the thickness of the glass plate W2 is thicker, it is preferable to widen the opening width of the V-groove VM (width in the Y-axis direction in FIG. 5) by using a cutting blade having a thicker blade thickness, and the depth of the V-groove VM. It is preferable that the depth is deeper.

Further, during the formation of the V-groove VM by cutting, the cutting water is injected from the cutting water supply nozzle 62 to the contact portion between the cutting blade 640b of the cutting blade 640 and the glass plate W2 and its surroundings. The cutting water injected from the cutting water supply nozzle 62 cools and cleans the processing point, dissolves the water-soluble protective film G, and removes it from the other surface W2a of the glass plate W2.

When the plate-shaped work W is sent to a predetermined position in the X-axis direction in which the cutting blade 640 finishes cutting one line consisting of the glass plate division starting point M1, the cutting feed of the plate-shaped work W is once stopped and cutting is performed. The blade 640 is separated from the glass plate W2, and then the plate-shaped work W is returned to the initial position at the start of cutting. Then, by sequentially performing the same cutting while indexing and feeding the cutting blade 640 in the Y-axis direction at intervals of the adjacent lines consisting of the glass plate division starting point M1, all of the other surfaces W2a of the glass plate W2 in the same direction. A V-groove VM is formed along a line consisting of the glass plate division starting point M1 of the above. Further, by rotating the plate-shaped work W by 90 degrees and then performing the same cutting process, a V-groove VM can be formed along all the lines including the glass plate division starting point M1 of the glass plate W2.

Since the glass plate W2 is a hard and difficult-to-cut material, for example, processing the glass plate W2 with a rotating cutting blade 640 may take a long time, but in the V-groove forming process, the cutting blade is as described above. Since it is not necessary to cut the 640 deeply into the glass plate W2, the processing time can be shortened. Further, it is possible to suppress the wear of the cutting blade 640.

In the method for dividing a plate-shaped work according to the present invention, a protective film forming step for forming a protective film G that protects the other surface W2a of the glass plate W2 is provided before the glass plate dividing starting point forming step. In the division starting point forming step, when the glass plate W2 is irradiated with a pulsed laser beam to generate debris, that is, the glass plate dividing starting point is opened until the upper end side of the glass plate dividing starting point M1 opens on the other surface W2a of the glass plate W2. Even when M1 is elongated and formed, debris adhesion to the glass plate W2 can be prevented by the protective film G. Further, the protective film G to which the debris G is attached can be efficiently removed together with the debris with the cutting water supplied to the cutting blade 640 in this V-groove forming step.
The formation of the V-groove is not limited to the one formed by cutting with the cutting blade 640. As described in Japanese Patent Application Laid-Open No. 2016-164908 (Patent Document 2), the glass plate W2 of the plate-shaped work W is obliquely irradiated with a laser beam having an absorbable wavelength, and the cross section is V-shaped. A V-groove may be formed. In this case, the protective film G can prevent debris from adhering to the glass plate W2 when the V-groove is formed. Then, after the V-groove is formed, for example, the plate-shaped work W is transported to a cleaning device provided with a spin table or the like, and the protective film G is removed from the plate-shaped work W in the cleaning device.
Further, in the formation of the V-groove, the glass plate W2 is first irradiated with a laser beam from an oblique angle to form only the slope of the V-groove, and then a cutting blade 640 having a sharp tip is cut along the planned division line S. However, a V-groove may be formed. That is, the laser beam has the effect of forming the slope of the V-groove to suppress the consumption of the cutting blade 640, and the protective film G can be removed by the cutting water.

(5) Attachment of Protective Tape to Glass Plate In the plate-shaped work W on which the V-groove VM is formed, for example, as shown in FIG. 6, the other surface W2a of the glass plate W2 is attached to the protective tape T. The state is supported by the annular frame F via the protective tape T, and handling via the annular frame F becomes possible. When a protective member (not shown) is attached to the back surface W1b of the semiconductor wafer W1, the protective member is peeled off from the back surface W1b.

The protective tape T is, for example, a disk-shaped tape having an outer diameter larger than the outer diameter of the plate-shaped work W. In FIG. 6, the protective tape T has a circular shape on the outer peripheral portion of the adhesive surface of the protective tape T facing upward. The back surface of the annular frame F having the opening of is attached. Further, the plate-shaped work W is positioned above the adhesive surface of the protective tape T exposed in the opening of the annular frame F with the other surface W2a side of the glass plate W2 facing downward. At this time, the center of the glass plate W2 is aligned so as to substantially coincide with the center of the opening of the annular frame F. Then, the other surface W2a of the glass plate W2 is pressed against the adhesive surface of the protective tape T, and the protective tape T is attached to the other surface W2a of the glass plate W2. In this way, the plate-shaped work W is supported by the annular frame F via the protective tape T, and a protective member (not shown) is peeled off from the back surface W1b of the semiconductor wafer W1 facing upward. When attaching the protective tape to the glass plate, the annular frame F is not used, and a protective tape having a diameter similar to that of the glass plate W2 is attached to the other surface W2a of the glass plate W2, and the other surface W2a is attached. The surface W2a may be protected.

(6) Wafer division starting point forming step Next, the semiconductor wafer W1 is irradiated with a pulsed laser beam having a wavelength having a transmittance, condensed inside the semiconductor wafer W1, and becomes the wafer division starting point along the planned division line S. Form a layer. The wafer division starting point forming step may be performed before the protective tape is attached to the glass plate (5).

The holding surface of the chuck table 40 of the laser processing apparatus 4 shown in FIG. 7 and the other surface W2a protected by the protective tape T of the plate-shaped work W are aligned so as to face each other, and the plate-shaped work W is made into a semiconductor. The wafer W1 is placed on the chuck table 40 with the back surface W1b facing up. Then, a suction source (not shown) connected to the chuck table 40 operates to suck and hold the plate-shaped work W on the chuck table 40.

Then, the plate-shaped work W held by the chuck table 40 is sent in the −X direction (forward direction), and the alignment means 44 detects the scheduled division line S. That is, from the image of the scheduled division line S captured by the imaging means 440, the alignment means 44 executes image processing such as pattern matching, and the position of the scheduled division line S to be irradiated with the pulse laser beam is detected.

As the scheduled division line S is detected, the pulsed laser beam irradiating means 41 is driven in the Y-axis direction, and the scheduled split line S for irradiating the pulsed laser beam and the condenser 411 are aligned in the Y-axis direction. Is done. This alignment is performed so that, for example, the center line of the scheduled division line S is located directly below the condenser lens 411a provided in the condenser 411.

Next, the setting unit 410b makes adjustments so that the pulsed laser beam oscillator 410a can oscillate a pulsed laser beam having a wavelength (for example, a wavelength in the near infrared region) that is transparent to the semiconductor wafer W1. Further, the condenser 411 positions the focusing point of the pulsed laser beam having transparency with respect to the semiconductor wafer W1 at a predetermined height position inside the semiconductor wafer W1 corresponding to the scheduled division line S. Further, the setting unit 410b sets the repetition frequency and the pulse width of the pulsed laser beam oscillated by the pulsed laser beam oscillator 410a. Then, while irradiating the pulsed laser beam oscillated from the pulsed laser beam oscillator 410a and condensed by the condenser lens 411a along the scheduled division line S, the plate-shaped work W is processed in the −X direction at a predetermined processing feed rate. Then, as shown in FIG. 7, a modified layer M2 serving as a waiha division starting point is formed inside the semiconductor waha W1. That is, the pulsed laser beam before reaching the focusing point has transparency to the semiconductor wafer W1, but the pulsed laser beam reaching the focusing point is locally very close to the semiconductor wafer W1. Shows high absorption characteristics. Therefore, the semiconductor wafer W1 near the condensing point is modified by absorbing the pulsed laser beam, and the modified layer M2 having a predetermined length is formed mainly upward from the condensing point.

A modified layer M2 is continuously formed inside the semiconductor wafer W1 along the center line of the planned division line S, and for example, a predetermined division line S is determined in the X-axis direction to finish irradiating one scheduled division line S with a pulsed laser beam. The plate-shaped work W is advanced to the position in the −X direction. Next, the irradiation of the pulsed laser beam is stopped, the machining feed of the plate-shaped work W in the −X direction (forward direction) is stopped once, and the pulsed laser beam irradiating means 41 is moved in the + Y direction to generate the pulsed laser beam. The scheduled division line S located next to the irradiated scheduled division line S and not yet irradiated with the pulsed laser beam and the condenser 411 are aligned in the Y-axis direction. Next, the plate-shaped work W is processed and fed in the + X direction (return direction), and the pulsed laser beam is irradiated to the scheduled division line S in the same manner as the irradiation of the pulsed laser beam in the forward direction. By sequentially irradiating the same pulsed laser beam, the pulsed laser beam is irradiated from the back surface W1b side of the semiconductor wafer W1 along all the scheduled division lines S extending in the X-axis direction, and the wafer is divided inside the semiconductor wafer W1. The modified layer M2 serving as a starting point is formed.

By sequentially irradiating the same pulsed laser beam, the pulsed laser beam is irradiated along all the planned division lines S extending in the X-axis direction, and the modified layer M2 is formed along the planned division line S. .. Further, when the chuck table 40 is rotated 90 degrees and then the same pulse laser beam is irradiated, the modified layer M2 is formed along all the vertical and horizontal division scheduled lines S.

(7) Dividing Step The plate-shaped work W on which the modified layer M2 is formed is conveyed to the braking device 8 shown in FIG.
The braking device 8 includes, for example, a support unit 80 that supports the plate-shaped work W, and a pressing blade 81 that presses the plate-shaped work W along a planned division line S of the plate-shaped work W supported by the support unit 80. It is provided with a pressing feed means 82 that approaches and separates the pressing blade 81 in the vertical direction (Z-axis direction) with respect to the plate-shaped work W supported by the support unit 80.

The support unit 80 is composed of a pair of support members 801 arranged so as to form an elongated gap 800 extending in the X-axis direction between them. The support unit 80 can reciprocate in the Y-axis direction. For example, an alignment unit 89 made of a camera or the like is arranged above the support unit 80. The alignment unit 89 can perform image processing such as pattern matching based on the image acquired by the camera, and can detect the scheduled division line S to which the pressing blade 81 of the plate-shaped work W should be pressed. The alignment unit 89 may be arranged below the support unit 80, for example, and may be configured to image the V-groove VM of the plate-shaped work W from below through the gap 800.

The pressing blade 81 has, for example, an acute-angled tip portion 81a, and extends linearly in the X-axis direction with the tip portion 81a as the lower end. The pressing blade 81 is connected to the pressing feeding means 82, and the pressing feeding means 82 lowers the pressing blade 81 in a direction approaching the plate-shaped work W to push the plate-shaped work W through the pressing blade 81. Can be pressed. The pressing blade 81 may be formed in a circular shape.

In carrying out the dividing step, for example, the plate-shaped work W is placed on the support unit 80 with the back surface W1b of the semiconductor wafer W1 facing up, and the plate-shaped work W is placed on the support unit 80 by a fixed clamp or the like (not shown) via the annular frame F. W is fixed in place. The plate-shaped work W may be placed on the support unit 80 so that the other surface W2a of the glass plate W2 faces upward. Based on the image of the back surface W1b of the semiconductor wafer W1 captured by the camera of the alignment unit 89, the alignment unit 89 detects the position of the scheduled division line S to be divided by the pressing blade 81. Based on the detection result of the alignment unit 89, the support unit 80 moves in the Y-axis direction, and the planned division line S to be divided is positioned so as to come to the center of the gap 800 formed by the pair of support members 801.

Next, the pressing feed means 82 lowers the pressing blade 81 in the −Z direction, and the tip portion 81a of the pressing blade 81 presses the plate-shaped work W from the back surface W1b side. The glass plate W2 is divided from the glass plate division starting point M1 by the vertical pressing force applied from the pressing blade 81 to the plate-shaped work W, and the plate-shaped work W is divided into the glass plate dividing starting point M1 and the wafer division. It is divided along the scheduled division line S starting from the starting point M2.

The pressing blade 81 divides the plate-shaped work W along the scheduled division line S starting from one glass plate dividing starting point M1 and the wafer dividing starting point M2, and then separates the pressing blade 81 from the plate-shaped work W. Then, while index-feeding the support unit 80 at intervals of each scheduled division line S in the Y-axis direction, the glass plate division start point M1 and the wafer division start point M2 are positioned at the center of the gap 800, and the plate-shaped work W is formed by the pressing blade 81. Is pressed, and the plate-shaped work W is cut one after another along the planned division line S extending in the X-axis direction. In addition to the configuration in which the support unit 80 is index-fed in the Y-axis direction, the plate-shaped work W may be index-fed in the Y-axis direction.

Next, the plate-shaped work W is rotated by 90 degrees, and then the plate-shaped work W is divided into individual device chips by carrying out the same dividing step along the planned division line S extending in the Y-axis direction. Can be done.

As described above, the method for dividing the glass plate according to the present invention has a holding step of holding one surface W2b side of the glass plate W2 and transparency from the other surface W2a side of the glass plate W2 to the glass plate W2. A division starting point M1 (glass plate) including pores M1a extending in the thickness direction of the glass plate W2 and amorphous M1b surrounding the pores M1a by irradiating a pulsed laser beam of a wavelength and condensing the inside of the glass plate W2. The tip is V on the other surface W2a of the glass plate W2 in which the division starting point M1) is formed and the division starting point forming step (glass plate dividing starting point forming step) is formed by arranging the dividing starting points M1) inside the glass plate W2. It is provided with a V-groove forming step of cutting a sharp cutting blade 640 and forming a V-groove VM along the glass plate dividing starting point M1. After the V-groove forming step, an external force is applied to the glass plate dividing starting point M1. By further performing the dividing step of dividing the glass plate W2 starting from the glass plate dividing starting point M1, chipping or chipping may occur mainly on the outer peripheral portion of the other surface W2a of the divided glass plate W2. It can be prevented by the V-groove VM.

As described above, in the method for dividing a plate-shaped work according to the present invention, the glass plate W2 is irradiated with a pulsed laser beam having a wavelength having a transmittance and condensed inside the glass plate W2 in the thickness direction of the glass plate W2. A glass plate division starting point M1 having an extending pore M1a and an amorphous M1b surrounding the pores M1a is linearly arranged and formed inside the glass plate W2 along a planned division line S. After the forming step and the glass plate dividing starting point forming step, a cutting blade 640 having a V-shaped tip is cut into the other surface W2a of the glass plate W2 along the glass plate dividing starting point M1 and V is formed along the dividing starting point. In the V-groove forming step of forming the groove VM, the semiconductor waiha W1 is irradiated with a pulsed laser beam having a wavelength having transparency, and the glass is focused inside the semiconductor waha W1 to serve as a waiha division starting point along the scheduled division line S. An external force is applied to the waiha division starting point forming step of forming the modified layer M2 and the glass plate dividing starting point M1 and the waha dividing starting point M2 to divide the semiconductor waha W1 and the glass plate W2 along the planned division line S to divide the chip. Since the dividing step of forming is provided, the V-groove VM prevents chipping and chipping mainly on the outer peripheral portion of the other surface W2a of the glass plate W2 of the divided and manufactured device chip. Is possible.

The method for dividing the glass plate and the method for dividing the plate-shaped work according to the present invention are not limited to the above embodiments, and the protective film forming means 2 and the laser processing apparatus 4 shown in the attached drawings are not limited to the above embodiments. The configurations of the cutting device 10 and the braking device 8 are not limited to this, and can be appropriately changed within the range in which the effects of the present invention can be exhibited.

W: Plate-shaped work W1: Semiconductor wafer W1a: Surface of semiconductor wafer W1b: Back surface of semiconductor wafer S: Scheduled division line D: Device W2: Glass plate W2a: Other surface of glass plate W2b: One surface of glass plate J : Resin 2: Protective film forming means 20: Chuck table 20a: Holding surface 21: Nozzle
22: Water-soluble protective film agent supply means 4: Laser processing device 40: Chuck table
41: Pulse laser beam irradiating means 410: Pulse laser beam oscillating means 410a: Pulse laser beam oscillator 410b: Setting unit 411: Condenser 411a: Condensing lens
44: Alignment means 440: Imaging means M1: Glass plate division starting point M1a: Pore M1b: Amorphous 6: Cutting device 65: Chuck table 64: Cutting means 640: Cutting blade 640a: Base 640b: Cutting blade 641: Spindle 63: Alignment means 630: Imaging means 62: Cutting water supply nozzle VM: V groove M2: Modified layer 8: Braking device 80: Support unit 81: Pressing blade 82: Pressing feed means 89: Alignment unit

Claims (1)

A surface and one surface of the glass plate of the semiconductor wafer in which the devices are formed in the regions partitioned by the dividing lines on the surface of the plate workpiece adhered with resin is divided along the dividing lines chip It is a method of dividing a plate-shaped work that forms a
A pulsed laser beam having a wavelength that is transparent to the glass plate is irradiated from the other surface side of the glass plate, condensed inside the glass plate, and surrounds the pores extending in the thickness direction of the glass plate and the pores. A glass plate division starting point forming step of forming a glass plate dividing starting point including an amorphous glass plate inside the glass plate along the planned division line, and a step of forming the glass plate dividing starting point.
After the glass plate division starting point forming step, a cutting blade having a V-shaped tip is cut into the other surface of the glass plate along the glass plate dividing starting point to form a V groove along the glass plate dividing starting point. V-groove forming process and
A modified layer that irradiates a pulsed laser beam with a wavelength that is transparent to the semiconductor wafer from the surface side to which the glass plate is not adhered, condenses it inside the semiconductor wafer, and serves as the wafer division starting point along the planned division line. A step of forming a wafer division starting point for forming a semiconductor wafer and a dividing step of forming a chip by applying an external force to the wafer dividing starting point and the wafer dividing starting point to divide the semiconductor wafer and the glass plate along the planned division line. With
A protective film forming step of forming a protective film that protects the other surface of the glass plate is provided before the glass plate division starting point forming step, and the protective film formed in the protective film forming step is the V-groove forming step. in you remove the cutting water supplied to the cutting blade plate workpiece dividing method.

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