CN101456222A - Method for cutting wafer - Google Patents

Abstract

The present invention provides a wafer dividing method capable of efficiently dividing a plurality of wafers along grid-shaped lanes. The surface of the wafer is divided into a plurality of regions by grid-shaped partitions, and a plurality of devices are formed on the partitioned regions. For the device, in the method for dividing the above-mentioned wafer, in the state where a plurality of optical device wafers are pasted on the surface of the dicing tape mounted on the ring frame, the following steps are carried out: a laser processing groove forming step, along the interval lanes for multiple The wafers are respectively irradiated with laser light, thereby forming laser processing grooves on the wafer along the interval roads; the dividing process divides the wafer into individual devices along the interval roads formed with the laser processing grooves; The devices are peeled from the dicing tape and picked.

Description

Wafer Separation Method

technical field

The present invention relates to a method for dividing a wafer. The surface of the wafer is divided into a plurality of regions by grid-shaped spacers, and a plurality of devices are formed on the divided regions. The method for dividing the wafer is along the The lanes divide the wafer into individual devices.

Background technique

Optical device wafers are divided into a plurality of regions on the surface of a sapphire substrate or the like by dividing lines called streets formed in a grid pattern, and optical devices such as gallium nitride-based compound semiconductors are stacked on the divided regions. , the optical device wafer is divided into light-emitting diodes and other optical devices along the interval lanes, and is widely used in electrical equipment.

Cutting of such an optical device wafer along the lanes is generally performed by a cutting device in which a cutting blade rotates at a high speed and cuts. However, since the sapphire substrate has a high Mohs hardness and is a difficult-to-cut material, the processing speed needs to be slowed down, resulting in poor productivity.

In recent years, as a method of dividing an optical device wafer along the lanes, a method has been proposed in which a laser-processed groove is formed by irradiating pulsed laser light having absorption properties with respect to the wafer along the lanes, and by External force is applied to break the wafer. (For example, refer to Patent Document 1.)

Patent Document 1: Japanese Patent Application Laid-Open No. 10-305420

However, the diameter of the sapphire substrate on which the above-mentioned optical device wafer is formed is about 50 mm, which is relatively small. On the other hand, the chuck table holding the wafer of the laser processing apparatus is configured to have a size corresponding to a semiconductor wafer having a diameter of 200 to 300 mm. Therefore, in order to effectively utilize the holding surface of the chuck table, a plurality of optical device wafers are attached to an adhesive tape attached to a ring frame, and the plurality of optical device wafers attached to the adhesive tape are held in the chuck. On the workbench, and implement laser processing, thereby improving productivity.

In this way, by affixing a plurality of optical device wafers on the adhesive tape attached to the ring frame, holding the plurality of optical device wafers attached to the adhesive tape on the chuck table, and then irradiating laser light along the interval lanes light, so as to form laser processing grooves on the optical device wafer along the interval road, and then implement the dividing process, that is, the optical device wafers with laser processing grooves formed along the interval roads are moved and pasted on the dicing tape one by one, along the interval The road separates the optical device wafer. Therefore, it is necessary to carry out the process of transferring and attaching the wafer having the laser-processed grooves formed along the lanes to the dicing tape, which is not necessarily satisfactory in terms of productivity.

Contents of the invention

The present invention has been made in view of the above facts, and its main technical task is to provide a wafer dividing method capable of efficiently dividing a plurality of wafers along grid-shaped streets.

In order to solve the above-mentioned main technical problems, according to the present invention, a method for dividing a wafer is provided. The wafer is divided into a plurality of regions by grid-shaped partitions formed on the surface, and the divided regions are formed with A plurality of devices, the method for dividing the above-mentioned wafer divides the above-mentioned wafer into individual devices along the above-mentioned interval road, and it is characterized in that,

The dividing method of above-mentioned wafer comprises following operation:

Wafer supporting process, sticking a plurality of wafers on the surface of the dicing tape installed on the ring frame;

a laser processing groove forming step of irradiating laser beams along the interval lanes to the plurality of wafers attached to the surface of the above-mentioned dicing tape attached to the above-mentioned annular frame, thereby forming laser processing grooves along the interval lanes on the plurality of wafers;

A dividing step, in a state where the wafer having laser-processed grooves formed along the intervals is pasted on the surface of the above-mentioned dicing tape, dividing the above-mentioned wafer into individual devices along the intervals formed with the laser-processed grooves; and

In the picking-up step, after the above-mentioned dividing step is performed, the individual devices separated from the dicing tape are peeled off and picked up.

The laser processing groove forming step is carried out using a laser processing device including: a chuck table holding a workpiece held on the chuck table; a laser beam irradiation member for irradiating laser light to the workpiece held on the chuck table; As for the imaging means for photographing the workpiece held on the chuck table, in the above-mentioned laser machining groove forming step, after the alignment step is performed, laser light is irradiated to the plurality of wafers respectively along the interval lanes, wherein in the above-mentioned In the alignment process, the plurality of wafers held on the chuck table with the dicing tape interposed therebetween are photographed by the imaging unit, and the spacing lanes formed on the wafers and the laser beam irradiation position of the laser beam irradiation unit are respectively determined for the plurality of wafers. position aligned.

In addition, it is preferable to expand the dicing tape so as to form gaps between the individual devices when the above-mentioned picking-up step is carried out.

In the wafer dividing method of the present invention, since a plurality of optical device wafers are pasted on the surface of the dicing tape mounted on the ring frame, the following steps are carried out: the laser processing groove forming step, along the separation lane A plurality of wafers are respectively irradiated with laser light, thereby forming laser processing grooves on the wafer along the interval road; a dividing process, dividing the wafer into individual devices along the interval road formed with the laser processing groove; One device is peeled from the dicing tape and picked up, so multiple wafers can be efficiently divided.

Description of drawings

FIG. 1 is a perspective view of an optical device wafer as a wafer divided by a method for dividing a wafer according to the present invention.

2 is a perspective view showing a state in which a plurality of optical device wafers shown in FIG. 1 are pasted on the surface of a dicing tape mounted on a ring frame in a wafer supporting step in the method of dividing a wafer according to the present invention.

3 is a perspective view of a laser processing apparatus for performing a laser processing groove forming step in the wafer dividing method of the present invention.

FIG. 4 shows a state in which a plurality of optical device wafers attached to the surface of the dicing tape attached to the ring frame shown in FIG. 2 are held at predetermined positions on the chuck table of the laser processing apparatus shown in FIG. 3 An explanatory diagram of the relationship of the coordinates below.

5 is an explanatory diagram of a laser machining groove forming step in the wafer dividing method of the present invention.

6 is an enlarged cross-sectional view of a main part of an optical device wafer subjected to a laser machining groove forming step in the wafer dividing method of the present invention.

FIG. 7 is a perspective view of a dividing apparatus for carrying out the dividing step and the picking-up step in the wafer dividing method of the present invention.

Fig. 8 is an exploded perspective view showing a main part of the dividing device shown in Fig. 7 .

Fig. 9 is a cross-sectional view showing a second table, a frame holding member, and a belt expanding member constituting the dividing device shown in Fig. 7 .

FIG. 10 is an explanatory view showing a dividing step in the wafer dividing method of the present invention.

FIG. 11 is an explanatory diagram showing a pick-up step in the wafer dividing method of the present invention.

Label description

1: Laser processing device; 2: Stationary base; 3: Chuck table mechanism; 36: Chuck table; 37: Processing feed member; 374: X-axis position detection member; 38: First index feed Giving component; 384: Y-axis position detection component; 4: Laser beam irradiation unit support mechanism; 42: Movable support base; 43: Second index feed component; 5: Laser beam irradiation unit; 52: Laser beam Illumination component; 522: condenser; 55: camera component; 6: control component; 7: dividing device; 70: base; 71: first workbench; 72: second workbench; 75: frame holding member; 76 : belt expansion member; 760: expansion drum; 77: rotating member; 78: ultrasonic vibration applying member; 8: detecting member; 9: picking member; 10: optical device wafer; 101: spacer; 102: device; 110: laser Processing groove; F: ring frame; T: cutting belt.

Detailed ways

Preferred embodiments of the method for dividing a wafer according to the present invention will be described in more detail below with reference to the drawings.

FIG. 1 shows an optical device wafer 10 divided by the wafer dividing method of the present invention. The optical device wafer 10 shown in FIG. 1 is divided into a plurality of regions on the surface 10a of a sapphire substrate with a diameter of 50 mm, for example, by grid-shaped partitions 101, and a plurality of light-emitting diodes are formed in the divided regions. and other optical devices 102 .

When the optical device wafer 10 configured as described above is divided into individual optical devices 102 along the lanes 101, the optical device wafer 10 is first attached to the surface of a dicing tape attached to a ring frame. However, since the optical device wafer 10 has a relatively small diameter of 50 mm as described above, if it is divided one by one, the productivity will be poor. Therefore, as shown in FIG. The device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, and 10-7 are pasted on the surface of the dicing tape T attached to the ring frame F on the respective back surfaces 10b (wafer supporting process). Therefore, the respective surfaces 10a of the plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, and 10-7 are located on the upper side. Also, the ring frame F is made of a metal material such as stainless steel, and the dicing tape T is made of a synthetic resin sheet such as polyolefin, and an adhesive layer with a thickness of about 5 μm is formed on the surface. In this way, the wafer supporting step of attaching a plurality of optical device wafers 10 to the surface of the dicing tape T attached to the ring frame F can be performed using, for example, a tape bonding machine disclosed in JP-A-2006-324502.

After performing the above-mentioned wafer supporting step, an alignment step and a laser machining groove forming step are carried out. Holding on the chuck table of the laser processing device, the plurality of optical device wafers 10 are respectively aligned with the spacer 101 formed on the optical device wafer 10 and the laser beam irradiation position of the laser beam irradiation member of the laser processing device In the laser machining groove forming step, laser beams are irradiated to the plurality of optical device wafers 10 along the spacing lanes 101 to form laser machining grooves along the spacing lanes 101 on the plurality of optical device wafers 10 . The alignment step and the laser processing groove forming step are carried out using the laser processing device shown in FIG. 3 .

The laser processing device 1 shown in Fig. 3 comprises: a stationary base 2; On the seat 2, it is used to hold the workpiece; the laser light irradiates the unit support mechanism 4, which can follow the direction of the indexing feed shown by the arrow Y (X-axis direction) perpendicular to the direction shown by the arrow X above ( Y-axis direction) is arranged on the stationary base 2; and a laser beam irradiation unit 5 is arranged on the support of the above-mentioned laser beam irradiation unit in a manner capable of moving in a direction (Z-axis direction) shown by arrow Z. Institution 4 on.

The above-mentioned chuck table mechanism 3 includes: a pair of guide rails 31, 31 arranged parallelly on the stationary base 2 along the processing feed direction (X-axis direction) shown by the arrow X; The first slide block 32 arranged on the above-mentioned guide rails 31, 31 in a manner to move in the processing feed direction (X-axis direction); in a manner capable of moving in the indexing feed direction (Y-axis direction) shown by arrow Y The second slider 33 arranged on the first slider 32; the cover table 35 supported on the second slider 33 via the cylindrical member 34; and the chuck table 36 as a workpiece holding member . The chuck table 36 includes a suction chuck 361 formed of a porous material, and a workpiece such as a disk-shaped semiconductor wafer is held on the suction chuck 361 by a suction member (not shown). The chuck table 36 configured in this way is rotated by the pulse motor 360 arranged in the cylindrical member 34 . In addition, a clamp 362 for fixing a ring frame to be described later is disposed on the chuck table 36 .

The above-mentioned first slider 32 is provided with a pair of guided grooves 321, 321 on its lower surface to cooperate with the above-mentioned pair of guide rails 31, 31, and on its upper surface is provided with an indexing feed direction along the arrow Y. (Y-axis direction) A pair of guide rails 322, 322 formed in parallel. The first slide block 32 constituted in this way is configured to be able to move along the pair of guide rails 31, 31 in the processing feed direction (X axis) shown by the arrow X by engaging the guided grooves 321, 321 with the pair of guide rails 31, 31. direction) to move up. The chuck table mechanism 3 in the illustrated embodiment includes a machining feed member 37 for making the first slider 32 move along the pair of guide rails 31, 31 in the machining progress indicated by the arrow X. Move in the given direction (X-axis direction). The machining feed member 37 includes an externally threaded rod 371 arranged in parallel between the pair of guide rails 31 and 31 , and a driving source such as a pulse motor 372 for driving the externally threaded rod 371 to rotate. One end of the externally threaded rod 371 is freely rotatably supported on a bearing block 373 fixed on the above-mentioned stationary base 2 , and the other end of the externally threaded rod 371 is in transmission connection with the output shaft of the above-mentioned pulse motor 372 . In addition, the externally threaded rod 371 is screwed into an internally threaded through hole formed in an unillustrated internally threaded block protrudingly provided on the lower surface of the central portion of the first slider 32 . Therefore, by using the pulse motor 372 to drive the externally threaded rod 371 to rotate forward and backward, the first slider 32 moves along the guide rails 31 , 31 in the machining feed direction (X-axis direction) indicated by the arrow X.

The laser processing apparatus 1 in the illustrated embodiment has an X-axis direction position detecting member 374 for detecting the X-axis direction position which is the processing feed amount of the chuck table 36 . The X-axis direction position detection member 374 includes: a linear scale 374a arranged along the guide rail 31; and a read head 374b arranged on the first slider 32 and along the linear The scale 374a moves. In the illustrated embodiment, the head 374b of the X-axis direction position detecting means 374 sends a pulse signal of one pulse to the control means described later every time the head 374b travels by 1 μm. Then, the control means described later detects the machining feed amount of the chuck table 36 , that is, the position in the X-axis direction by counting the input pulse signal. In addition, when the pulse motor 372 is used as the driving source of the processing feed member 37, by counting the driving pulses of the control member described later that outputs a driving signal to the pulse motor 372, the position of the chuck table 36 can also be detected. The machining feed is the position in the X-axis direction. In addition, when a servo motor is used as the driving source of the above-mentioned processing feeding member 37, by sending a pulse signal output from a rotary encoder that detects the rotation speed of the servo motor to the control member described later, the control member controls the processing feed member 37. The input pulse signal is counted, and the machining feed rate of the chuck table 36 , that is, the position in the X-axis direction can be detected.

The above-mentioned second slider 33 is provided with a pair of guided grooves 331, 331 on its lower surface to cooperate with a pair of guide rails 322, 322, and the pair of guide rails 322, 322 are arranged on the upper surface of the above-mentioned first slider 32. By engaging the guided grooves 331, 331 with the pair of guide rails 322, 322, the second slider 33 is configured to be movable in the index feed direction (Y-axis direction) indicated by arrow Y. The chuck table mechanism 3 in the illustrated embodiment includes a first index feed member 38 for making the second slider 33 set on the first slider 32 along the A pair of guide rails 322, 322 moves in the index feed direction (Y-axis direction) shown by arrow Y. The first index feeding member 38 includes an externally threaded rod 381 arranged in parallel between the pair of guide rails 322 and 322 , and a driving source such as a pulse motor 382 for driving the externally threaded rod 381 to rotate. One end of the externally threaded rod 381 is freely rotatably supported on a bearing block 383 fixed on the upper surface of the first slider 32 , and the other end of the externally threaded rod 381 is in transmission connection with the output shaft of the pulse motor 382 . In addition, the male thread rod 381 is screwed into a female thread through hole formed in a not shown female thread block protrudingly provided on the lower surface of the central portion of the second slider 33 . Therefore, by using the pulse motor 382 to drive the externally threaded rod 381 to rotate forward and backward, the second slider 33 moves along the guide rails 322 , 322 in the index feed direction (Y-axis direction) indicated by the arrow Y.

The laser processing apparatus 1 in the illustrated embodiment has a Y-axis direction position detection member 384 for detecting the indexing feed amount of the chuck table 36 , that is, the Y-axis direction position. The Y-axis direction position detection member 384 includes: a linear scale 384a arranged along the guide rail 322; and a reading head 384b arranged on the second slider 33 and along with the second slider 33 The linear scale 384a moves. In the illustrated embodiment, the head 384b of the Y-axis direction position detecting means 384 sends a pulse signal of one pulse to the control means described later every time the head 384b travels by 1 μm. Then, the control means described later detects the index feed amount of the chuck table 36 , that is, the position in the Y-axis direction by counting the input pulse signal. In addition, when the pulse motor 382 is used as the driving source of the above-mentioned index feeding member 38, by counting the driving pulses of the control member described later that outputs a driving signal to the pulse motor 382, the chuck table can also be detected. The index feed amount of 36 is the position in the Y-axis direction. In addition, in the case of using a servo motor as the drive source of the first index feed member 38, the pulse signal output by the rotary encoder that detects the rotation speed of the servo motor is sent to the control member described later, and the control The member counts the input pulse signal, and can also detect the index feed amount of the chuck table 36 , that is, the position in the Y-axis direction.

Above-mentioned laser beam irradiation unit supporting mechanism 4 comprises: along the index feed direction (Y-axis direction) shown by arrow Y a pair of guide rails 41,41 that are arranged on the stationary base 2 in parallel; The movable support base 42 is arranged on the guide rails 41 , 41 so as to move in the direction indicated by Y. The movable support base 42 is composed of a movable support portion 421 movably disposed on the guide rails 41 , 41 , and a mounting portion 422 mounted on the movable support portion 421 . A pair of guide rails 423 , 423 extending in a direction indicated by an arrow Z (Z-axis direction) are provided in parallel on one side of the mounting portion 422 . The laser beam irradiation unit support mechanism 4 in the illustrated embodiment includes a second index feed member 43 for moving the movable support base 42 along the pair of guide rails 41, 41 moves in the index feed direction (Y-axis direction) shown by arrow Y. The second index feeding member 43 includes an externally threaded rod 431 arranged in parallel between the pair of guide rails 41 and 41 , and a driving source such as a pulse motor 432 for driving the externally threaded rod 431 to rotate. One end of the externally threaded rod 431 is rotatably supported on an unillustrated bearing block fixed on the stationary base 2 , and the other end of the externally threaded rod 431 is drive-connected to the output shaft of the pulse motor 432 . In addition, the externally threaded rod 431 is screwed into a female threaded hole formed in an unillustrated female thread block protrudingly provided on the lower surface of the central portion of the movable support portion 421 constituting the movable support base 42 . . Therefore, by using the pulse motor 432 to drive the externally threaded rod 431 to rotate forward and backward, the movable support base 42 moves along the guide rails 41, 41 in the index feed direction (Y-axis direction) indicated by the arrow Y.

The laser beam irradiation unit 5 in the illustrated embodiment includes a unit holder 51 and a laser beam irradiation member 52 mounted on the unit holder 51 . The unit holder 51 is provided with a pair of guided grooves 511, 511, which are slidably engaged with a pair of guide rails 423, 423 provided on the above-mentioned mounting part 422. By making the guided grooves 511, 511 511 cooperates with the above-mentioned guide rails 423, 423, and the unit holder 51 is supported so as to be movable in the direction indicated by the arrow Z (Z-axis direction).

The laser beam irradiation unit 5 in the illustrated embodiment includes a moving member 53 for moving the unit holder 51 in the direction indicated by the arrow Z (Z-axis direction) along the pair of guide rails 423 , 423 . The moving member 53 includes: an externally threaded rod (not shown) arranged between a pair of guide rails 423 and 423, and a driving source such as a pulse motor 532 for driving the externally threaded rod to rotate. The illustrated externally threaded rod rotates forward and backward to move the unit holder 51 and the laser beam irradiation member 52 in the direction indicated by the arrow Z (Z-axis direction) along the guide rails 423 , 423 . In addition, in the illustrated embodiment, the laser beam irradiating member 52 moves upward by driving the pulse motor 532 to rotate forward, and the laser beam irradiating member 52 moves downward by driving the pulse motor 532 in reverse.

The laser beam irradiation member 52 includes a cylindrical housing 521 fixed to the unit holder 51 and extending substantially horizontally. Inside the housing 521 is provided a pulsed laser beam oscillating member, which includes a pulsed laser beam oscillator composed of a YAG laser oscillator or a YVO4 laser oscillator, and a repetition rate setting member. In an embodiment, the pulsed laser light oscillating means oscillates the pulsed laser light having a wavelength (for example, 355 nm) that is absorptive to the sapphire substrate. A condenser 522 in which a condenser lens (not shown) is accommodated is attached to the front end portion of the housing 521 . The laser beam oscillated from the above-mentioned pulsed laser light oscillating member reaches the condenser 522 through a transmission optical system not shown, and is irradiated from the condenser 522 with a predetermined spot diameter to be held on the above-mentioned chuck table 36. processed objects.

The laser processing device in the illustrated embodiment includes an imaging unit 55 disposed at the front end of the casing 521 for imaging a processing area to be laser processed by the above-mentioned laser beam irradiation unit 52 . The imaging unit 55 includes an illuminating unit for illuminating the workpiece, an optical system for capturing an area illuminated by the illuminating unit, and an imaging device (CCD) for capturing an image captured by the optical system. The means 55 transmits the captured image signal to the control means described later.

The laser processing apparatus 1 in the illustrated embodiment includes a control member 6 . The control unit 6 is composed of a computer, which includes a central processing unit (CPU) 61 that performs calculation processing according to a control program, a read-only memory (ROM) 62 that stores control programs, etc., and a readable and writable random access memory that stores calculation results, etc. (RAM) 63 , counter 64 , input interface 65 and output interface 66 . Detection signals from the above-described X-axis direction position detection means 374 , Y-axis direction position detection means 384 , imaging means 55 and the like are input into the input interface 65 of the control means 6 . Then output control signals from the output interface 66 of the control member 6 to the pulse motor 360 , pulse motor 372 , pulse motor 382 , pulse motor 432 , pulse motor 532 , pulse laser light irradiation member 52 , and display member 60 .

When using the above-mentioned laser processing apparatus 1 to carry out the above-mentioned alignment process and the laser processing groove forming process, the plurality of optical device wafers 10-1, 10 attached to the dicing tape T mounted on the ring frame F as shown in FIG. -2, 10-3, 10-4, 10-5, 10-6, and 10-7 are placed on the chuck table 36 of the laser processing apparatus 1 shown in FIG. 1 on the dicing tape T side. Then, a plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10-7 are separated by dicing tape T by operating a suction member (not shown). Suction remains on the chuck table 36. In addition, the ring frame F is fixed by clamps 362 .

A plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10-7 held on the chuck table 36 as described above become positioned as shown in FIG. The state of the coordinate position shown in (a). In addition, (b) in FIG. 4 has shown the state which the chuck table 36 rotated 90 degrees from the state shown in FIG. 4 (a). After attracting and holding a plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, and 10-7 on the chuck table 36 in this way, each optical device wafer 10. An alignment step is performed, that is, the positioning of the partition road 101 and the light collector 522 (laser beam irradiation position) of the laser beam irradiation member 52 is performed. When performing the alignment process, firstly, the processing feeding member 37 is operated to hold a plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, and 10-7. The chuck table 36 is positioned directly below the imaging member 55 .

After the chuck table 36 is positioned directly below the imaging member 55, the imaging member 55 scans the plurality of optical device wafers 10-1, 10 held on the chuck table 36 in the state of (a) in FIG. -2, 10-3, 10-4, 10-5, 10-6, 10-7 are photographed, and the image data thereof are sent to the control member 6 . The control means 6 obtains the coordinates of the plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, and 10-7 based on the image data transmitted from the imaging means 55. , and store its coordinate values in random access memory (RAM) 63. Next, the process feed member 37 and the first index feed member 38 are operated to move the chuck table 36 to position the optical device wafer 10 - 1 directly under the imaging member 55 . Then, the street 101 formed on the optical device wafer 10-1 extending along a predetermined direction (the X-axis direction in the state of FIG. to the control member 6. The control means 6 judges whether or not the partition lane 101 is parallel to the X-axis based on the image data sent from the imaging means 55 . Then, when the partition road 101 is not parallel to the X-axis, the pulse motor 360 is operated to rotate the chuck table 36 to adjust the partition road 101 to be parallel to the X-axis (θ correction step). The rotational position at this time is stored in a random access memory (RAM) 63 .

Then, the processing feeding member 37 and the first index feeding member 38 are moved to move the chuck table 36, and each spaced road formed on the optical device wafer 10-1 of the state shown in (a) in FIG. 101 are respectively positioned directly below the imaging member 55, and utilize the imaging member 55 to respectively photograph the left end (starting point) and the right end (end point) in Fig. 4 (a) of each interval lane 101, and send its image data to the control member 6. The control means 6 stores the image data sent from the imaging means 55 in the random access memory (RAM) 63 as the start point coordinates and the end point coordinates of the irradiated laser light for each lane (start point and end point coordinate detection process). In this way, the coordinate values of the start point and the end point of the irradiation laser light of each spaced lane 101 extending along the predetermined direction of the optical device wafer 10-1 are obtained, and then the pulse motor 360 is operated to rotate the chuck table 36 by 90 degrees, and the The optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10-7 are positioned in the state of (b) in FIG. 4 . Then, the above-mentioned starting point and ending point coordinate detection process is performed for each of the streets 101 formed in the direction orthogonal to the above-mentioned predetermined direction of the optical device wafer 10-1 positioned in the state of (b) in FIG. 4 .

After performing the θ correction process and the start and end point coordinate detection process on the optical device wafer 10-1 as described above, other optical device wafers 10-2, 10-3, 10- 4, 10-5, 10-6, and 10-7 carry out the above-mentioned θ correction process and the start point and end point coordinate detection process in sequence.

As described above, each of the plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, and 10-7 held on the chuck table 36 was respectively implemented. After the calibration process including the above-mentioned θ correction process and the start point and end point coordinate detection process, the laser processing groove formation process is implemented, that is, the laser beam is irradiated to each optical device wafer 10 along the spacer 101, so that the edge of each optical device wafer 10 is formed. Laser-machined grooves are formed along the spacers 101 . That is, the processing feed member 37 and the first index feed member 38 are moved, and the chuck table 36 is moved to the laser beam irradiation area where the light collector 522 is located as shown in FIG. The predetermined spaced lanes 101 on the device wafer 10 - 1 are positioned directly under the light concentrator 522 . At this time, the chuck table 36 is positioned at the rotational position that has been corrected in θ by the θ correction step described above and stored in the random access memory (RAM) 63 . Then, according to the starting point coordinate value stored in the random access memory (RAM) 63, as shown in FIG. . The control of positioning the predetermined starting point coordinate value of the lane 101 directly under the condenser 522 is performed based on detection signals from the X-axis direction position detection means 374 and the Y-axis direction position detection means 384 . Then the laser beam irradiation member 52 is moved, and the pulsed laser beam is irradiated from the light collector 522, and the processing feed member 37 is moved simultaneously, so that the chuck table 36 is shown by the arrow X1 in FIG. 5 at a predetermined processing feed speed. Move in the machining feed direction (laser beam irradiation process). At this time, the converging point P of the pulsed laser light irradiated from the concentrator 522 is aligned near the surface 10a of the optical device wafer 10-1. Then, according to the end point coordinate value stored in the random access memory (RAM) 63, after the end point coordinate value (the right end in Fig. 5) of the predetermined interval track 101 arrives directly below the light collector 522, the chuck operation is stopped The movement of the stage 36 and the irradiation of the pulsed laser light are stopped. In addition, control for stopping the movement of the chuck table 36 is performed based on a detection signal from the X-axis direction position detection member 374 . As a result, as shown in FIG. 6 , laser-processed grooves 110 are formed along the streets 101 on the optical device wafer 10 - 1 .

In addition, the processing conditions in the said laser processing groove formation process are set as follows, for example.

Light source: LD excitation Q switch Nd: YVO4 laser

Wavelength: 355nm

Repetition frequency : 100kHz

Average output : 1.0W

Focus spot diameter : Φ10μm

Processing feed speed : 100mm/sec

After carrying out the above-mentioned laser processing groove forming process along all the spacers 101 extending in the predetermined direction of the optical device wafer 10-1 in this way, the chuck table 36 is rotated by 90 degrees, and then along the above-mentioned predetermined direction Each of the streets 101 extending in the orthogonal direction is subjected to the above-mentioned laser machining groove forming step.

After performing the above-mentioned laser machining groove formation process along all the spacers 101 formed on the optical device wafer 10-1 as described above, the optical device wafers 10-2, 10-3, 10-4, 10- 5, 10-6, and 10-7 carry out the above-mentioned laser machining groove forming steps in sequence. As a result, a plurality of optical device wafers 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10 - 7 , laser-processed grooves 110 are formed along all the lanes 101 , respectively.

After performing the above-mentioned laser processing groove formation process, in the state where the plurality of optical device wafers 10 are pasted on the surface of the dicing tape T, a division process and a pick-up process are performed. In the division process, the plurality of optical device wafers 10 are The optical device wafer 10 is divided into individual devices 102 along the lanes 101 formed with laser-processed grooves 110; The dividing step and the picking-up step are carried out using the dividing apparatus shown in FIGS. 7 to 9 . FIG. 7 is a perspective view of the dividing device, and FIG. 8 is an exploded perspective view showing the main parts of the dividing device shown in FIG. 7 . The dividing device 7 shown in Fig. 7 to Fig. 9 comprises: a base 70, a first workbench 71 arranged on the base 70 in a manner capable of moving along the direction shown by the arrow Y, and a first workbench 71 capable of moving along the direction indicated by the arrow Y The second table 72 is disposed on the first table 71 so as to move in a direction indicated by an arrow X perpendicular to Y. The base 70 is formed in a rectangular shape, and two guide rails 701 and 702 are arranged parallel to each other along the direction indicated by the arrow Y on the upper surfaces of both sides. In addition, a guide groove 701a having a V-shaped cross section is formed on the upper surface of one guide rail 701 of the two guide rails.

The first table 71 is formed in the shape of a window frame having a rectangular opening 711 in the center as shown in FIG. 8 . A side lower surface of the first table 71 is provided with a guided rail 712 slidably engaged with a guide groove 701 a formed in a guide rail 701 provided on the base 70 . In addition, two guide rails 713 and 714 are arranged in parallel to each other along the direction perpendicular to the guide rail 712 on the upper surface of both sides of the first table 71 . In addition, a guide groove 713a having a V-shaped cross section is formed on the upper surface of one guide rail 713 of the two guide rails. With regard to the first table 71 thus constituted, as shown in FIG. The surface is mounted on another guide rail 702 provided on the base 70 . The wafer splitting device 7 in the illustrated embodiment includes a first moving member 73 that moves the first table 71 along the guide rails 701 and 702 provided on the base 70 in the direction indicated by the arrow Y. direction to move. As shown in Figure 8, the first moving member 73 has: an externally threaded rod 731 arranged in parallel with another guide rail 702 provided on the base 70; One end is supported as a rotatable bearing 732; connected with the other end of the externally threaded rod 731 and used to drive the pulse motor 733 to rotate the externally threaded rod 731; The rod 731 is screwed into an internally threaded block 734 . The first moving member 73 configured in this way moves the first table 71 in the direction indicated by the arrow Y by driving the pulse motor 733 to rotate the externally threaded rod 731 .

The second table 72 is formed in a rectangular shape as shown in FIG. 8 and has a circular hole 721 in the center. A side lower surface of the second table 72 is provided with a guided rail 722 slidably engaged with a guide groove 713 a formed in a guide rail 713 provided on the first table 71 . With regard to the second table 72 constituted in this way, as shown in FIG. The lower surface of the side portion is placed on another guide rail 714 provided on the first workbench 71 . The splitting device 7 in the illustrated embodiment comprises a second moving member 74, and the second moving member 74 makes the second table 72 move along the guide rails 713, 714 provided on the first table 71 in the direction indicated by the arrow X. direction to move. As shown in Figure 8, the second moving member 74 has: an external threaded rod 741 arranged in parallel with another guide rail 714 provided on the first workbench 71; One end of the threaded rod 741 is supported as a rotatable bearing 742; the other end of the external threaded rod 741 is connected to a pulse motor 743 for driving the rotation of the external threaded rod 741; And an internally threaded block 744 screwed with the externally threaded rod 741 . The second moving member 74 configured in this way moves the second table 72 in the direction indicated by the arrow X by driving the pulse motor 743 to rotate the externally threaded rod 741 .

The dividing device 7 in the illustrated embodiment includes: a frame holding member 75 holding the above-mentioned ring frame F; The cutting zone T dilates. As shown in FIGS. 7 and 9 , the frame holding member 75 includes: a ring-shaped frame holding part 751 whose inner diameter is larger than the diameter of the hole 721 provided on the second workbench 72; and a plurality of clampers as fixing members. 752, which are arranged on the outer periphery of the above-mentioned frame holding member 751. The upper surface of the frame holding member 751 forms a mounting surface 751a on which the annular frame F is placed, and the annular frame F is placed on the mounting surface 751a. In addition, the ring-shaped frame F placed on the mounting surface 751 a is fixed to the frame holding member 751 by clamps 752 . The frame holding member 75 configured in this way is supported vertically by a support member 763 arranged above the hole 721 of the second table 72 and constituting a belt expansion member 76 described later.

As shown in FIGS. 7 and 9 , the belt expansion member 76 includes an expansion drum 760 disposed inside the above-mentioned annular frame holding member 751 . The inner diameter and outer diameter of the expansion drum 760 are smaller than the inner diameter of the ring frame F and larger than the bonding area of the plurality of optical device wafers 10 attached to the dicing tape T mounted on the ring frame F. In addition, the expansion drum 760 has a mounting portion 761 at its lower end, and a support flange 762 formed radially protrudingly on the upper outer peripheral surface of the mounting portion 761 , and the mounting portion 761 is rotatably connected to the set. It fits on the inner peripheral surface of the hole 721 of the above-mentioned second workbench 72 . The belt expansion member 76 in the illustrated embodiment has a support member 763 that enables the above-mentioned annular frame holding member 751 to advance and retreat in the vertical direction. The support member 763 is constituted by a plurality of air cylinders 763a disposed on the support flange 762, and a piston rod 763b is connected to the lower surface of the annular frame holding member 751 described above. In this way, the support member 763 constituted by the plurality of air cylinders 763a moves the annular frame holding member 751 in the vertical direction between the reference position where the mounting surface 751a and the upper end of the expansion drum 760 are approximately positioned. The position at the same height; the expansion position is a position at which the mounting surface 751 a is lower than the upper end of the expansion drum 760 by a predetermined amount. Therefore, the support member 763 constituted by the plurality of air cylinders 763 a functions as an expansion movement member that relatively moves the expansion drum 760 and the frame holding member 751 in the vertical direction.

As shown in FIG. 7 , the dividing device 7 in the illustrated embodiment includes a rotating member 77 that rotates the expansion drum 760 and the frame holding member 751 described above. This rotating member 77 has: a pulse motor 771 arranged on the above-mentioned second table 72 , a pulley 772 mounted on the rotation shaft of the pulse motor 771 , and a support wound around the pulley 772 and the expansion drum 760 . Annulus 773 on flange 762. The rotating member 77 configured in this way rotates the expansion drum 760 and the frame holding member 751 via the pulley 772 and the endless belt 773 by driving the pulse motor 771 .

The dividing device 7 in the illustrated embodiment has an ultrasonic vibration applying member 78 as an external force applying member that acts an external force on a plurality of optical device wafers 10 supported on the ring frame F via a dicing tape T. , wherein the ring-shaped frame F is held on the above-mentioned ring-shaped frame holding member 751 . The ultrasonic vibration applying member 78 is arranged on the above-mentioned base 70 and arranged inside the expansion drum 760 . As shown in Figure 8, this ultrasonic vibration applying member 78 has: the air cylinder 781 that is arranged on the base 70, the ultrasonic vibration element 783 that is arranged on the upper end of the piston rod 782 of this air cylinder 781, and the ultrasonic vibration element 783 that is installed on this ultrasonic vibration The vibration transmitting member 784 on the upper surface of the vibrating element 783 applies AC power of a predetermined frequency (for example, 100 kHz) to the ultrasonic vibrating element 783 through the power supply means (not shown). In addition, the vibration transmitting member 784 constituting the ultrasonic vibration applying member 78 is formed in a disk shape having a diameter substantially equal to that of the optical device wafer 10 .

Returning to FIG. 7 to continue the description, the dicing device 7 in the illustrated embodiment has a detection member 8 for detecting the optical device wafer 10 supported on the ring frame F via the dicing tape T and for the dicing described later. One-by-one devices, wherein the ring-shaped frame F is held on the above-mentioned ring-shaped frame holding member 751 . The detection member 8 is attached to an L-shaped support column 81 provided on the base 70 . The detecting means 8 is composed of an optical system, an imaging device (CCD), and the like, and is disposed above the above-mentioned ultrasonic vibration applying means 78 . The detecting member 8 configured in this way takes an image of the optical device wafer 10 supported on the ring frame F via the dicing tape T and the individual devices which will be described later, converts it into an electrical signal, and sends it to an unillustrated The control member, wherein the ring frame F is held on the above ring frame holding part 751.

In addition, as shown in FIG. 7 , the dividing device 7 in the illustrated embodiment has a pick-up member 9 that picks up, from the dicing tape T, devices that are divided one by one, which will be described later. The pickup member 9 is composed of a swivel arm 91 arranged on the base 70 and a pickup chuck 92 attached to the front end of the swivel arm 91 , and the swivel arm 91 is swiveled by a driving member not shown. In addition, the swivel arm 91 is configured to be movable up and down, and the pickup chuck 92 attached to the front end can pick up the components stuck on the dicing tape T. As shown in FIG.

Referring mainly to FIG. 7 and FIG. 10 , the dividing step will be described. In this dividing step, the plurality of optical device wafers on which the laser machining grooves 110 are formed by performing the above laser machining groove forming process are divided into two parts using the dividing apparatus 7 configured as described above. 10 is divided into individual devices 102 .

As shown in (a) in FIG. 10 , the ring-shaped frame F supporting the plurality of optical device wafers 10 subjected to the above-mentioned laser machining groove forming process through the dicing tape T is placed on the frame holding member 75 constituting the frame holding member 75 . On the mounting surface 751 a of the member 751 , the ring frame F is fixed to the frame holding member 751 by clamps 752 . At this time, the frame holding member 751 is positioned at the reference position shown in FIG. 10( a ).

After holding the ring frame F supporting the plurality of optical device wafers 10 through the dicing tape T on the frame holding member 751, the first moving member 73 and the second moving member 74 are operated to move the first table 71 along the The direction shown by the arrow Y (refer to FIG. 7 ) moves, and the second stage 72 is moved along the direction shown by the arrow X (refer to FIG. 7 ), so that, for example, the optical device wafer 10 is moved as shown in (a) in FIG. -1 is located directly above the ultrasonic vibrating element 783 . Then make the air cylinder 781 that constitutes the ultrasonic vibration applying element 78 act, the vibration transmission member 784 is lifted, and as shown in FIG. regional contacts. Then, AC power of a predetermined frequency (for example, 100 kHz) is applied to the ultrasonic vibration element 783 by a power supply means not shown. Accordingly, ultrasonic vibrations are applied to the optical device wafer 10 - 1 via the vibration transmission member 784 and the dicing tape T . As a result, the strength of the optical device wafer 10-1 decreases due to the formation of the laser-processed grooves 110 along the streets 101, so the optical device wafer 10-1 is divided into individual devices 102 along the streets 101 (dividing process) . In addition, as a method of applying an external force to the wafer in the above-mentioned dividing step, an example of applying ultrasonic vibration to the wafer was shown, but other dividing methods such as a method of attracting and holding the dicing via the streets formed on the wafer may also be used. Tape T, and make the dicing tape T deviate from the direction perpendicular to the spacer, so that the wafer is divided along the spacer where the strength is reduced due to the formation of the laser processing groove.

After performing the dividing process on the optical device wafer 10-1 as described above, the first moving member 73 and the second moving member 74 are operated to position, for example, the optical device wafer 10-2 directly above the ultrasonic vibrating element 783, The above-described dividing step is performed on the optical device wafer 10-2. Thereafter, the above-described dividing steps are also sequentially performed on the optical device wafers 10-3, 10-4, 10-5, 10-6, and 10-7.

By performing the dividing process on all the optical device wafers 10 attached to the dicing tape T attached to the ring frame F as described above, all the optical device wafers 10 are divided into The devices 102 are separated one by one, and then a pick-up process of peeling and picking up the individual devices 102 from the dicing tape T is performed.

As shown in FIG. 11( a ), in this pickup step, the air cylinder 781 constituting the ultrasonic vibration applying member 78 is operated to lower the vibration transmission member 784 . Next, a plurality of air cylinders 763a serving as support members 763 constituting the belt expansion member 76 are operated to lower the annular frame holding member 751 to the expansion position shown in FIG. 11( b ). Therefore, the annular frame F fixed on the mounting surface 751a of the frame holding member 751 also descends, so as shown in FIG. The edges are abutted and thus expanded. As a result, gaps S are formed between the individual divided devices 102 attached to the dicing tape T. As shown in FIG. Thereafter, as shown in FIG. 11( b ), the pickup member 9 is operated, and the individual devices 102 are picked up by the pickup chuck 92 and transported to a tray or die bonding process not shown. In this pick-up process, since the gap S is formed between the individual devices 102, when the device 102 is peeled off from the dicing tape T, it will not rub against the adjacent device 102, and it is possible to prevent the device 102 from being scratched. Device damage caused by impact.

As described above, in the wafer dividing method of the present invention, since the plurality of optical device wafers 10 are attached to the surface of the dicing tape T attached to the ring frame F, the above-mentioned laser machining groove forming step, Since the dividing process and the picking process are performed, a plurality of optical device wafers 10 can be efficiently divided.

Claims (3)

1, a kind of dividing method of wafer, wafer marks off a plurality of zones by the spacing track that is the formation of clathrate ground from the teeth outwards, and on this zone that marks off, be formed with a plurality of devices, the dividing method of above-mentioned wafer is divided into device one by one along above-mentioned spacing track with above-mentioned wafer, it is characterized in that

The dividing method of above-mentioned wafer comprises following operation:

The wafer supporting operation sticks on a plurality of wafers on the surface of the cutting belt that is installed on ring-shaped frame;

Laser processing groove forms operation, and a plurality of wafers of being pasted on the surface to the above-mentioned cutting belt that is installed on above-mentioned ring-shaped frame are along spacing track irradiating laser light, thereby forms laser processing groove along spacing track on a plurality of wafers;

Segmentation process sticks under the lip-deep state of above-mentioned cutting belt at the wafer that will be formed with laser processing groove along spacing track, along the spacing track that is formed with laser processing groove above-mentioned wafer is divided into device one by one; With

Pick up operation, after having implemented above-mentioned segmentation process, the device that is divided into is one by one peeled off and picked up from above-mentioned cutting belt.

2, the dividing method of wafer as claimed in claim 1 is characterized in that,

Above-mentioned laser processing groove forms operation and uses laser processing device to implement, and this laser processing device comprises: the chuck table that keeps machined object; To remaining on the laser light irradiation member of the machined object irradiating laser light on this chuck table; With the shooting member that the machined object that remains on this chuck table is taken, form in the operation in above-mentioned laser processing groove, after implementing calibration procedure, to a plurality of wafers respectively along spacing track irradiating laser light, wherein in above-mentioned calibration procedure, utilize above-mentioned shooting member respectively a plurality of wafers that remain on the above-mentioned chuck table across above-mentioned cutting belt to be taken, a plurality of wafers are formed on the position alignment of the laser light irradiation position of spacing track on the wafer and above-mentioned laser light irradiation member respectively.

3, the dividing method of wafer as claimed in claim 1 or 2 is characterized in that,

State when picking up operation on the implementation, thereby make above-mentioned cutting belt expansion between the device that is divided into one by one, form the gap.

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