TWI687985B - Splitting device and wafer splitting method - Google Patents

Abstract

A simple device configuration removes wrinkles from the tape and maintains the wafer spacing appropriately.

It is a wafer division method, which uses a wafer (W) supported on a ring frame (F) via an adhesive tape (T), and is divided into individual wafers (C) at a division starting point along a planned division line A dividing device, the structure of the wafer dividing method includes: a holding process which holds the ring frame in the ring frame holding portion (20) and holds the wafer inside the ring frame on the holding table (10) ; Splitting process, which divides the wafer at the starting point of splitting by separating the holding table and the ring frame holding part, and stretching the tape; and Wafer separation process, which is a heater that heat shrinks the stretched tape (51) The heating range is between the outer periphery of the wafer and the inner periphery of the ring frame, in the circumferential direction or the radial direction, each time a predetermined heating range is applied for heat shrinkage to separate the wafers.

Description

Splitting device and wafer splitting method

The invention relates to a dividing device and a dividing method of a wafer into which individual wafers are divided along a planned dividing line.

In recent years, there has been known a method of narrowing the line width of a predetermined dividing line of a wafer and increasing the amount of wafers taken from one wafer (for example, refer to Patent Document 1). The method of dividing a wafer described in Patent Document 1 irradiates a transparent laser beam to a wafer, and forms a modified layer along the line to be divided within the wafer. Then, by using an expansion device or the like, the tape attached to the ring frame is expanded, an external force is applied to the wafer attached to the tape, and the wafer is divided into individual wafers using the modified layer as a starting point for division.

Although the wafer gap is widened by the expansion of the tape, when the expansion of the tape is released, wrinkles (slack) are generated on the sheet, which may cause adjacent wafers to contact each other and cause damage. Therefore, a method of maintaining the wafer gap by heating the tape between the outer periphery of the wafer and the inner periphery of the ring frame and thermally shrinking it has been proposed (for example, refer to Patent Document 2). Furthermore, the proposal has a tape that is generated around the wafer by holding A method of applying thermal compression to wrinkles to remove wrinkles from the tape (for example, see Patent Document 3).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2005-129607

[Patent Document 2] Japanese Unexamined Patent Publication No. 2002-334852

[Patent Document 3] Japanese Patent Application Publication No. 2013-239557

However, when the tape is attached to the ring frame, the tension is applied in one direction of the tape, so in the other direction orthogonal to the direction of the applied tension, the opposite position of the tape sandwiching the wafer is easy in the radial direction Slack becomes wrinkles. In this case, in the method of Patent Document 2, since the tape between the outer periphery of the wafer and the inner periphery of the ring frame is heated likewise, wrinkles cannot be sufficiently removed from the tape. In the method of Patent Document 3, a structure for applying thermal pressure bonding to the entire circumferential direction of the adhesive tape is required, and the device configuration is complicated.

The present invention was created in view of such a problem, and its object is to provide a simple device configuration for removing a wrinkle from an adhesive tape and appropriately maintaining a wafer interval and a wafer division method.

The splitting device of the present invention is a work set that adheres to the opening of the ring-shaped frame and has a heat-shrinkable tape, and sticks the wafer with the starting point of splitting along the planned dividing line to the tape of the opening The tape is stretched, and the wafer is divided into wafers at the starting point of the division. The dividing device includes: a holding table that attracts and holds the wafer through the tape of the workpiece group; an annular frame holding portion, which is Holding the ring frame of the workpiece group; a pair of heaters, which heats the prescribed portion of the ring-shaped tape between the outer periphery of the wafer of the workpiece group and the inner periphery of the ring frame to make the crystal The center of the circle is arranged to face the center; the rotating means, which rotates a pair of the heaters with the center of the wafer as the axis; and the lifting means, which makes the holding table and the ring frame holding portion relative Up and down movement, with the holding table and the ring frame holding portion holding the workpiece group, the holding table is moved upward by the lifting means, and the ring frame holding portion is moved relative to the falling direction, And the holding table and the ring frame holding portion are spaced apart, the tape is stretched, the wafer is divided at the starting point of division, and the heater is made to the ring between the outer periphery of the wafer and the inner periphery of the ring frame The heating range of the tape in the circumferential direction or the radial direction is heated with a prescribed heating area each time, and the tape is thermally contracted with the prescribed heating area each time to separate the wafers.

The wafer dividing method of the present invention is a wafer dividing method using a dividing device. The dividing device includes: a holding table which is a heat-shrinkable adhesive tape which plugs the opening of the ring-shaped frame and adheres The wafer formed with the starting point of division along the planned dividing line is adhered to the tape of the workpiece group of the tape of the opening to attract and hold the wafer; the ring frame holds The part, which holds the ring frame of the workpiece group; the heater, which heats the prescribed portion of the ring-shaped tape between the outer periphery of the wafer of the workpiece group and the inner periphery of the ring frame; Rotating means, which rotates the heater around the center of the wafer; and lifting means, which moves the holding table and the ring-shaped frame holding portion up and down relative to each other, stretches the tape, and divides The starting point divides the wafer into a wafer, and the wafer dividing method is composed of the following processes: a holding process, which is to hold the workpiece group on the holding table and the ring frame holding part; a dividing process, which is After the holding process, the holding table is raised in the ascending direction by the lifting means, the ring frame holding portion is relatively moved in the lowering direction, and the holding table and the ring frame holding portion are spaced apart and stretched The tape, the wafer is divided at the starting point of the division; and a wafer separation process, which is to make the heater to the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring frame after the division process The heating range of is in the circumferential direction or the radial direction, and each time it is heated in a prescribed heating area, and the tape is thermally contracted to space the wafer.

If these structures are adopted, by separating the holding table and the ring-shaped frame holding portion and stretching the tape, the wafer is divided at the starting point of division to separate the wafers. Moreover, when the tension of the tape is released, wrinkles are generated in the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring frame. At this time, the heating range of the tape by the heater is heated in a predetermined heating area in the circumferential direction or the radial direction each time. Therefore, compared to the case where the entire looped tape is heated in the same manner, no large wrinkles remain on the tape. Accordingly, the wrinkle can be removed from the tape by a simple device configuration, and the crystal can be properly maintained The wafer interval after the circle is divided.

In the dividing device of the present invention, the rotation means includes: an angle recognition unit that recognizes the rotation angle; and a speed-adjustable means that causes the angle recognition unit to recognize the angle while heating within a predetermined angle range The rotation speed of the device can be adjusted, and the rotation speed can be adjusted by the speed adjustment means, and the tape is heated in a predetermined heating area in the circumferential direction each time.

In the wafer dividing method of the present invention, the wafer spacing process is composed of the following process: a first shrinking process, which uses the lifting means to move the holding table in the lowering direction and to make the ring frame holding portion Relatively move in the ascending direction, and bring the holding table and the ring frame holding portion close, and limit the ring-shaped tape that occurs between the outer periphery of the wafer and the inner periphery of the ring frame The part of the wrinkle is heated to heat shrink it; and the second shrinking process is that after the first shrinking process, the heater is rotated by the rotating means and the outer periphery of the wafer and the inner periphery of the ring frame The tape between the loops is heated in its entirety and heat-shrinked.

In the wafer dividing method of the present invention, the wafer interval process is composed of the following process: a proximity process, which is after the dividing process, the holding table and the ring frame holding portion are each moved by the lifting means Stepwise approach by a specified amount; and the third contraction process, which is to rotate the heater by the rotating means after the approaching process and to rotate the heater between the outer periphery of the wafer and the inner periphery of the ring frame The ring-shaped tape is heated and thermally contracted, and the approaching process and the third contraction process are repeated until the holding table is closest to the ring-shaped frame holding portion.

In the wafer dividing method of the present invention, the dividing device is provided with a radial advancing and retreating means for advancing and retreating the heater in the radial direction of the wafer, and the wafer interval process is provided with a fourth contraction process, which is used to describe Between the outer circumference of the wafer and the inner circumference of the ring frame, the wrinkled part of the ring-shaped tape and the elliptical orbit of the radial middle part of the ring-shaped tape, by the rotation means The radial advance and retreat means move the heater to heat the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring frame and heat shrink it.

In the wafer dividing method of the present invention, the rotation means includes: an angle recognition unit which recognizes the rotation angle; and a speed adjustable means which enables the angle recognition unit to recognize the angle side within the previously set angle range The rotation speed of the heater can be adjusted. The wafer spacing process uses the angle identification part to identify the rotation angle of the heater, and the rotation speed of the rotation means can be adjusted by the speed adjustment means under each angle range set in advance Adjust, and heat the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring frame and heat shrink it.

According to the present invention, if the heating range of the tape by the heater is in a circumferential direction or a radial direction, each time a predetermined heating area is heated by the heater, so that the tape is thermally contracted, so a simple device can be used The structure removes the wrinkles of the tape and appropriately maintains the wafer interval after the wafer is divided.

1‧‧‧splitting device

10‧‧‧Retainer

20‧‧‧ Ring frame holding part

40‧‧‧lifting means

50‧‧‧The means of heat shrink

51‧‧‧ Heater

52‧‧‧Rotation means

65‧‧‧Angle Recognition Department

66‧‧‧Speed adjustable means

81‧‧‧ Modified layer (segmentation starting point)

82‧‧‧Wrinkle

83‧‧‧ middle part

C‧‧‧chip

F‧‧‧ring frame

L‧‧‧Divide line

T‧‧‧ tape

W‧‧‧ Wafer

WS‧‧‧Workpiece group

FIG. 1 is a perspective view of a dividing device of this embodiment.

FIG. 2 is a top view of a workpiece group of this embodiment.

Fig. 3 is a perspective view of a heat shrinking means of this embodiment.

FIG. 4 is an explanatory diagram of a first division method of a wafer of this embodiment.

FIG. 5 is an explanatory diagram of a first division method of a wafer of this embodiment.

FIG. 6 is an explanatory diagram of a second division method of a wafer of this embodiment.

FIG. 7 is a diagram showing the change of the heating area in the second division method of the present embodiment.

FIG. 8 is an explanatory diagram of a third method of dividing a wafer of this embodiment.

FIG. 9 is an explanatory diagram of a fourth dividing method of the wafer of this embodiment.

Hereinafter, a method of dividing a wafer using a dividing device will be described. FIG. 1 is a perspective view of a dividing device of this embodiment. In addition, the dividing device of the present embodiment is not limited to the structure shown in FIG. 1. If the dividing device is capable of removing the expansion state of the tape in stages while removing the wrinkles of the tape by heating, any structure may be used.

As shown in FIG. 1, the dividing device 1 is configured to expand the tape T to divide the wafer W supported by the ring frame F via the tape T into individual wafers. Furthermore, the singulation device 1 is configured to release the expansion of the tape T while maintaining the gap between the wafers. When the expansion of the tape T is released, the heat shrinkage (Heat Shrink) removes Wrinkles between the inner circumference of the ring frame F. In this way, the adhesive tape T is stretched to shrink only the slack, maintaining the wafer interval so that the divided wafers of the wafer W contact each other without being damaged.

A grid-like planned dividing line L is provided on the surface of the wafer W, and various devices (not shown) are formed on the areas divided by the planned dividing line L. In addition, the wafer W may be a semiconductor wafer in which devices such as ICs and LSIs are formed on a semiconductor substrate such as silicon or gallium arsenide, or a light such as an LED formed on an inorganic material substrate of ceramics, glass, or sapphire. Device light device wafers are also available. The wafer W is adhered to the tape T attached to the ring frame F, and the work group WS composed of the wafer W, the ring frame F and the tape T is carried into the dividing device 1.

The ring-shaped frame F of the workpiece group WS is closed with an adhesive tape T having heat shrinkability, and the wafer W is adhered to the adhesive tape T inside the opening. Inside the wafer W, a modified layer 81 is formed as a division starting point of the planned division line L (see FIG. 4 ). In addition, the modified layer 81 becomes a state in which the density, refractive index, mechanical strength, or other physical properties inside the wafer W are different from those of the surroundings by laser irradiation, and refers to a region with lower intensity than the surroundings. The modified layer 81 is, for example, a melt-treated region, a crack region, an insulation breakdown region, and a refractive index change region, and may be a region in which these regions are mixed.

In the following description, although the modified layer 81 (see FIG. 4) formed inside the wafer W as a starting point of division is exemplified, it is not limited to this configuration. The starting point of the division may be the starting point when the wafer W is divided, for example, even if it is a laser processing groove, a cutting groove, or a scribe Lines can also be constructed. In addition, the tape T may be stretchable and heat-shrinkable, and the material is not particularly limited.

The dividing device 1 is provided with a holding table 10 capable of attracting and holding the wafer W via the tape T of the work group WS, and a ring frame holding portion 20 holding the ring frame F of the work group WS is arranged around the holding table 10. The holding table 10 is supported by a plurality of pillar portions 11, and a porous porous plate 13 is arranged on the upper surface of the holding table 10. The porous porous plate 13 forms a holding surface 14 that attracts and holds the wafer W on the upper surface of the holding table 10. The holding surface 14 is connected to the suction source 30 (refer to FIG. 4) through the flow path in the holding table 10, and the wafer W is sucked and held by the negative pressure generated on the holding surface 14.

Furthermore, a flow path connected from the holding surface 14 to the suction source 30 is provided with an on-off valve 31 (see FIG. 4 ), and the on-off valve 31 switches the suction holding and suction release of the holding surface 14. At the outer peripheral edge of the holding table 10, a plurality of roller portions 15 are provided throughout the entire circumference. The plural roller portions 15 are tapes T transferred from the lower side to the periphery of the wafer W while the wafer W is held on the holding surface 14. The plural roller portions 15 are transferred to the tape T, and when the tape T expands, the friction generated on the outer peripheral edge of the holding table 10 is suppressed.

The ring frame holding portion 20 holds the ring frame F on the mounting table 21 such that the cover plate 22 sandwiches the ring frame F on the mounting table 21 from above. Circular openings 23 and 24 having a larger diameter than the holding table 10 are formed in the center of the mounting table 21 and the cover plate 22, respectively. When the cover plate 22 is covered on the mounting table 21, the ring frame is held by the cover plate 22 and the mounting table 21 F, at the same time, a part of the wafer W and the tape T are exposed to the outside from the circular openings 23 and 24 of the mounting table 21 and the cover plate 22.

The ring frame holding portion 20 is in a state where the ring frame F on the mounting table 21 covers the cover plate 22, and the cover plate 22 is fixed to the mounting table 21 by, for example, a clamping portion (not shown). The ring-shaped frame holding portion 20 is supported by a lifting means 40 that moves the holding table 10 and the ring-shaped frame holding portion 20 relative to each other. The lifting means 40 is composed of four electric cylinders supporting the four corners of the mounting table 21. By the amount of protrusion of the cylinder rod 41 of the lifting and lowering means 40 being controlled, the distance between the wafer W on the holding table 10 and the ring frame holding portion 20 is adjusted.

Above the ring-shaped frame holding portion 20, a heat shrinking means 50 for heat shrinking the wrinkles of the tape T is provided. In the heat shrinking means 50, a pair of heaters 51 are arranged opposite to the center of the wafer W at a predetermined position between the outer periphery of the wafer W that heats the wafer W of the work group WS and the inner periphery of the ring frame F. For example, the heater 51 irradiates a spot with far-infrared rays with a peak waveform of 3 μm to 25 μm, which is difficult to be absorbed by a metal material, to suppress heating of various parts of the device, and can heat only the outer periphery of the wafer W and the inner periphery of the ring frame F The specific place of the circular tape T between them. Furthermore, the heat shrinking means 50 is provided with a rotation means 52 for rotating the pair of heaters 51 about the center of the wafer W, and a radial advance and retreat of the pair of heaters 51 in the radial direction of the wafer W Means 53.

In addition, the dividing device 1 is provided with a control means 70 that coordinates the various parts of the control device. The control means 70 is constituted by a microprocessor or memory that performs various processes. Memory system uses ROM according to application (Read Only Memory), RAM (Random Access Memory) and other memory media. The control means 70 is provided with a step operation means 71 that controls the step operation of the elevating means 40, a rotation control portion 72 that controls the rotation means 52, an advance and retreat control portion 73 that controls the forward and backward movement of the radial advance and retreat means 53, and heating of the heater 51 The timing heater control unit 74 and so on.

In such a dividing device 1, by being lowered while the ring-shaped frame holding portion 20 holds the ring-shaped frame F, the holding table 10 protrudes from the circular openings 23 and 24 of the cover plate 22 and the mounting table 21. By the holding table 10 relatively pushing up the ring-shaped frame holding portion 20, the tape T is expanded in the radial direction, and the wafer W is divided into individual wafers. Furthermore, when the ring-shaped frame holding portion 20 rises to release the expansion of the tape T, the tension of the tape T is relaxed. At this time, the tape T is heated by the heater 51 to be thermally contracted, so that the tape T around the wafer W does not become wrinkled.

However, it is not that when the expansion of the tape T is released after the wafer W is divided, the tape W around the wafer W produces the same wrinkles. For example, when the tape T is pasted in a state where tension is applied to the ring frame F in one direction, the tension of the tape T is biased in places where wrinkles are likely to be formed and places where wrinkles are difficult to be generated. Specifically, as shown in FIG. 2, when the wafer P is sandwiched in the direction P1 where the tension is applied in one direction, the tape T hardly becomes a wrinkle 82, and the wafer is sandwiched in the other direction orthogonal to the one direction W is opposite to P2, which easily becomes wrinkle 82. Furthermore, the tape T having directivity by the alignment of the polymer is biased in places where wrinkles are likely to occur in one direction along the direction of the tape T and where wrinkles are difficult to produce.

Therefore, even if the heater 51 is rotated by the rotating means 52 (refer to FIG. 1) and the tape T around the wafer W is heated likewise, it is difficult for the tape T to be appropriately wrinkled 82 where the P1 is thermally contracted. However, where the tape T easily becomes the wrinkle 82, P2 is hard to shrink. Therefore, in the dividing method of the wafer W of the present embodiment, after the heat shrinkage, the tape 51 does not leave wrinkles, and the heater 51 applies a predetermined heating range to the tape T in the circumferential direction or diameter. It is heat-shrinked by the prescribed heating area every time.

Hereinafter, with reference to FIGS. 3 to 9, a method of dividing a wafer by a dividing device will be described in detail. Fig. 3 is a perspective view of a heat shrinking means of this embodiment. 4 and 5 are explanatory diagrams of the first division method of the wafer of this embodiment. In addition, FIG. 4A is an example of a preservation process, and FIG. 4B is an example of a division process. FIG. 5A is an example of the first shrinking process of the wafer spacing process, FIG. 5B is an example of the second shrinking process of the wafer spacing process, and FIG. 5C is an example of the heating area of the tape by the heater. Furthermore, a reforming layer serving as a starting point for division is formed along the line to be divided within the wafer.

As shown in FIG. 3, the heat shrinking means 50 is configured to rotate the pair of heaters 51 supported by both end sides of the robot arm 55 around the vertical axis by the rotating means 52 to rotate the wafer W (see FIG. 2). The surrounding tape T (see FIG. 2) is heat-shrinked. A rotating shaft 56 is connected to the rotating means 52, and a support plate 57 supporting the robot arm 55 is fixed to the lower end of the rotating shaft 56. A fixing block 58 is provided under the support plate 57 and in front of the robot arm 55, and a diameter of the pair of heaters 51 on the wafer W is mounted on the fixing block 58. A pair of radial advancing and retreating means 53 moving forward and backward. Each radial advancing and retracting means 53 is an electric cylinder in which the heater 51 is fixed to the front end of the cylinder rod 54.

A pair of guides 59 that guide the heater 51 in the advancing and retreating direction are provided on the front surfaces of both end sides of the robot arm 55. Each guide 59 is provided with a slider 62 fixed to the support shaft 61 of the heater 51. By controlling the amount of protrusion of the cylinder rod 54 of the radial advance and retreat means 53, the heater 51 moves in the radial direction of the wafer W along the guide 59. Furthermore, the rotation axis 56 is positioned at the center of the wafer W, and by the rotation means 52, a pair of heaters 51 rotate around the vertical axis passing through the center of the wafer W. In this case, the heater 51 is not limited to one rotation, and the heater 51 may be shaken within a predetermined angle range (shake angle).

In this way, the pair of heaters 51 rotates around the vertical axis by the rotation means 52, and moves in the radial direction of the wafer W (refer to FIG. 2) by the radial advancement and retraction means 53, so that the tape T can be performed The heating range, in the circumferential direction or radial direction, can be heated with the specified heating area each time. By changing the heating area in the circumferential direction or the radial direction, the heater 51 is intensively heated where heat shrinkage is difficult. In the first division method of the wafer W, after a limited heating of the wrinkles caused by the wrinkles of the adhesive tape T is difficult, the ring exposed from the outer periphery of the wafer W and the inner periphery of the ring frame F is heated The whole shape of tape T.

Hereinafter, the first division method of the wafer W will be described. As shown in FIG. 4A, the maintenance project is first implemented. In the holding process, the workpiece group WS is held by the holding table 10 and the ring-shaped frame holding portion 20. That is, the wafer W is placed on the holding table 10 via the tape T, and the wafer W The surrounding ring frame F is held by the ring frame holding portion 20. At this time, the diameter of the holding table 10 is larger than that of the wafer W, and the roller portion 15 on the outer peripheral edge of the holding table 10 is in contact with the tape T between the wafer W and the ring frame F from the lower side. Furthermore, the on-off valve 31 is closed, and the attraction force from the attraction source 30 toward the holding table 10 is blocked.

As shown in FIG. 4B, after maintaining the project, the division project is implemented. In the dividing process, by moving the ring frame holding portion 20 to the lowering direction by the lifting means 40, the holding table 10 is relatively pushed up. The holding table 10 and the ring-shaped frame holding portion 20 are spaced apart, the tape T expands in the radial direction, and an external force is applied to the modified layer 81 (see FIG. 4A) of the wafer W via the tape T. The wafer W is divided into individual wafers C using the modified layer 81 whose strength has been reduced as a starting point for division. Furthermore, the tape T is stretched until the adjacent wafers C are completely spaced apart, forming a gap between the plurality of wafers C.

At this time, while the ring-shaped frame holding portion 20 is moved to the lowering direction and the tape T expands, the on-off valve 31 is closed, and the expansion of the tape T is not hindered by the attractive force of the holding table 10. Then, after the wafer W is divided into the individual wafers C to form an interval between the plurality of wafers C, the on-off valve 31 is opened on the holding table 10 to generate attraction (see FIG. 5 ). In the state where the tape T is stretched, since the holding table 10 attracts and holds the wafer C through the tape T, there is no case where the tape T shrinks, and the interval between adjacent wafers C is maintained.

As shown in FIG. 5A, after the singulation process, the first shrinking process of the wafer spacing process is performed. In the first contraction process, the ring frame holding portion 20 is moved to the upward direction by the lifting means 40 to hold The table 10 relatively approaches the ring-shaped frame holding portion 20 to release the expansion of the tape T. At this time, the tension of the tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F is relaxed, and wrinkles 82 are generated on the tape T around the wafer W (see FIG. 5C ). Since the ring-shaped frame holding portion 20 moves while holding the holding tape T on the holding table 10, even if the tension of the tape T around the wafer W relaxes on the tape T on the holding table 10, wrinkles 82 are not generated.

A pair of heaters 51 is positioned above the part of the wrinkle 82 of the tape T, and by the pair of heaters 51, the part of the wrinkle 82 is heated to shrink thermally. More specifically, around the wafer W, the tape T tends to be wrinkled 82, and a heating region R1 (see FIG. 5C) where the heater 51 heats the tape T is provided in an arc shape. In addition, the heater 51 is controlled to swing above the heating region R1, so that the rotation control unit 72 (refer to FIG. 1) and the rotation means 52 (refer to FIG. 3) are controlled within a predetermined angle range (swing angle) Rotation action. Accordingly, since the wrinkles 82 of the tape T are hard to shrink, the heater 51 is heated intensively to heat-shrink effectively.

As shown in FIG. 5B, after the first shrinking process, the second shrinking process of the wafer spacing process is performed. In the second shrinking process, the pair of heaters 51 are rotated by the rotating means 52 (see FIG. 3 ), and the tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F is collectively heated and thermally contracted . In this case, the heating region R2 (see FIG. 5C) where the heater 51 applies the tape T is set circularly around the wafer W. Since the tape T around the wafer W is heated throughout the entire The portions other than the heat-shrinkable area are also heat-shrinked effectively by the heater 51 being heated.

In the first and second shrinking processes, during the thermal contraction of the tape T around the wafer W, the tape T is attracted and held on the holding table 10 to maintain the gap between the wafers C. At this time, since only the tape T around the wafer W is thermally contracted, even if the suction holding of the holding table 10 is released, the gap between the wafers C is maintained while being maintained. After the second contraction process, the on-off valve 31 is closed, and the suction of the tape T by the holding table 10 is released so that the conveyance of the workpiece group WS can be performed.

In this way, in the first division method of the wafer W, the area where the tape T around the wafer W is difficult to thermally shrink is set as the arc-shaped heating area R1, and the tape T around the wafer W is provided as a whole The heating area R2 is a circular shape, and the heating range of the heater 51 is thermally contracted each time by a predetermined heating area in the radial direction. Since the wrinkles 82 of the tape T are hard to be thermally contracted and concentratedly heated, the tape T is effectively thermally contracted to maintain the wafer interval of the divided wafer W.

In addition, the wafer division may be implemented by the second wafer division method shown below. The second division method of the wafer will be described with reference to FIGS. 6 and 7. FIG. 6 is an explanatory diagram of a second division method of a wafer of this embodiment. FIG. 7 is a diagram showing the change of the heating area in the second division method of the present embodiment. In addition, the second dicing method of the wafer is different from the first dicing method only for the wafer spacing process. Therefore, only the wafer spacing process will be described here. 6A and 6C show an example of the approaching process of the wafer spacing process, and FIG. 6B shows an example of the third shrinking process.

As shown in FIG. 6A, after the singulation process, the approach process of the wafer interval process is performed. In the approaching process, the holding table 10 and the ring-shaped frame holding section 20 are gradually approached by a predetermined amount each time by the lifting and lowering means 40 to slowly release the expansion of the tape T. That is, the step operation means 71 (see FIG. 1) controls the step operation of the elevating means 40 and stops at a position where the ring frame holding portion 20 rises slightly. Accordingly, the tension of the tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F is relaxed by only one step, and small wrinkles 82 are generated on the tape T around the wafer W (see FIG. 2 ). In addition, since the ring-shaped frame holding portion 20 moves in a state where the holding tape T is attracted to the holding table 10, even if the tension of the tape T around the wafer W relaxes on the tape T on the holding table 10, wrinkles 82 will not occur .

As shown in FIG. 6B, after the approaching process, the third shrinking process of the wafer spacing process is performed. In the third shrinking process, the pair of heaters 51 are rotated by the rotating means 52 (refer to FIG. 3 ), and the tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F is heated and thermally contracted. Accordingly, the tape T is heated by the heater 51 over the entire circumference, and the small wrinkles 82 (see FIG. 2) generated in the approach process are thermally contracted. In this case, the heater 51 may irradiate far-infrared rays even if the tape T has the ring frame F side as the target. According to this, it is possible to suppress the damage of the wafer W caused by the irradiation of the far infrared rays of the heater 51.

As shown in FIG. 6C, after the third contraction process, the approach process is performed again. In the second approaching process, the ring-shaped frame holding portion 20 is further raised and is closer to the holding table 10 than the first approaching process The ring frame holding portion 20 is stopped. Accordingly, the tension of the tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F is further relaxed by one step, and a new wrinkle 82 is generated in the tape T around the wafer W (see FIG. 2 ). Then, the third shrinking process is performed again, the tape T is heated by the heater 51 over the entire circumference, and the small wrinkles 82 newly generated in the second approaching process are heat-shrinked.

This approaching process and the third contraction process are repeated until the holding table 10 and the ring-shaped frame holding portion 20 are closest. The closest relationship between the holding table 10 and the ring-shaped frame holding portion 20 refers to the positional relationship before returning to the initial state before division. The tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F gradually relaxes through a plurality of steps, and small wrinkles 82 (refer to FIG. 2) generated in each step are heated by the heater 51 to be thermally contracted . Accordingly, the wrinkle 82 of the tape T does not increase, and the wrinkle 82 of the tape T is gradually thermally contracted by the heater 51.

In the third shrinking process, during the thermal shrinkage of the tape T around the wafer W, the tape T is attracted and held on the holding table 10 to maintain the gap between the wafers C. Furthermore, since only the tape T around the wafer W is thermally contracted, even if the suction holding of the holding table 10 is released, the gap between the wafers C is maintained while being maintained. After the holding table 10 and the ring-shaped frame holding portion 20 are closest to each other, the on-off valve 31 is closed, and the suction of the tape T of the holding table 10 is released, so that the workpiece group WS can be transported.

Furthermore, as shown in FIG. 7, in the second division method, the holding table 10 (see FIG. 6A) and the ring frame holding portion 20 (see FIG. 6A) In the farthest state, since the tape T is stretched very long, the position P3 of the tape T separated from the outer periphery of the wafer W is heated by the heater 51. When the holding table 10 and the ring frame holding portion 20 approach and the tape T shrinks, only the portion where the tape T shrinks, the position P4 close to the tape T on the outer periphery of the wafer W is heated by the heater 51. That is, although a heating area (not shown) for the tape T by the heater 51 is provided in a circle around the wafer W, each time the holding table 10 and the ring-shaped frame holding portion 20 approach The distance from the outer periphery of the circle W to the heating area becomes shorter.

In this way, in the second division method of the wafer W, a circular heating area is set at a different distance from the outer periphery of the wafer W, and the tape T is heated in a predetermined heating area in the radial direction to heat stepwise shrink. According to this, while the tension of the tape T is gradually relaxed and the wrinkle 82 (refer to FIG. 2) of the tape T is increased, the wrinkle 82 is thermally shrunk stepwise by heating by the heater 51. According to this, since the wrinkle 82 of the tape T is difficult to thermally shrink, no large wrinkle 82 remains, and the tape T is effectively shrunk to maintain the wafer interval of the divided wafer W.

However, in the first and second division methods described above, although the heater is rotated at a constant speed, it is not limited to this structure. For example, as shown in FIG. 8, even if the rotation speed can be adjusted while rotating the heater. Hereinafter, the third method of dividing the wafer will be described. FIG. 8 is an explanatory diagram of a third method of dividing a wafer of this embodiment. In addition, the third division method of the wafer is different from the first and second division methods only for the wafer separation process. Therefore, only the wafer spacing process will be described here.

As shown in FIG. 8, around the wafer W, the opposite side of the tape T sandwiching the wafer W is difficult to thermally shrink due to the wrinkles 82. In this case, although it is considered to reduce the rotation speed of the rotation means 52 to increase the heating time of the tape T by the heater 51 over the entire circumference, productivity (UPH: Unit Per Hour) per unit time decreases. Then, the rotation speed of the rotation means 52 is adjusted so that the portion of the wrinkle 82 generated in the ring-shaped tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F, the heater 51 operates at a low speed, and the wrinkle For parts other than 82, the heater 51 operates at a high speed.

In this case, the rotation means 52 is provided with an angle recognition part 65 for recognizing the rotation angle, and a speed at which the rotation speed of the heater 51 can be adjusted while the angle recognition part recognizes the angle within a predetermined angle range (heating area) Adjustable means 66. The angle recognition unit 65 and the speed adjustable means 66 are controlled by the rotation control unit 72 (refer to FIG. 1) of the control means 70. The angle identifying section 65 recognizes the rotation angle of the heater 51, and the speed adjustment means 66 is used to adjust the rotation speed of the rotation means 52 in each angle range set in advance to heat the outer periphery of the wafer W and the ring frame F The endless tape T between the inner circumferences is heat-shrinked.

That is, the predetermined heating area of the ring-shaped tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F is heated by changing the speed of the heater 51 within a predetermined angle range. The angle range (heating area) θ1 where wrinkles 82 are generated on the tape T and it is difficult to shrink by heat, and the rotation means 52 (refer to FIG. 3) are rotated by the speed adjustable means 66 When the speed drops, the heater 51 passes at a low speed above the wrinkle 82 that is produced on the tape T, and the wrinkle 82 is heated by the heater 51 for a long time. Furthermore, in the angle range (heating area) θ2 where the tape T is easily thermally contracted, the rotation speed of the rotation means 52 is increased by the speed adjustment means 66, the heater 51 passes over the tape T at a high speed, and the heater 51 Heat the tape T for a short time. According to this, since the wrinkle 82 of the tape T is hard to be thermally shrunk concentratedly by the heater 51, the tape T is effectively thermally shrunk to maintain the wafer interval of the divided wafer W. Furthermore, since the rotation speed can be partially increased, the productivity per unit time is improved. In this manner, the rotation speed of the heater 51 is changed in the heating area (angle range θ1, θ2) to effectively shrink the tape T, and the wafer interval of the divided wafer W is maintained.

In addition, in the first to third division methods described above, although the heater is rotated to draw a circular trajectory, it is not limited to this configuration. For example, as shown in FIG. 9, the heater may be rotated in such a manner that an elliptical track is drawn. Hereinafter, the fourth division method of the wafer will be described. FIG. 9 is an explanatory diagram of a fourth dividing method of the wafer of this embodiment. In addition, the fourth division method of the wafer is different from the first to third division methods only for the wafer spacing process. Therefore, only the wafer spacing process will be described here.

As shown in FIG. 9, around the wafer W, the opposing position of the tape T sandwiching the wafer W makes it difficult to thermally shrink close to the outer periphery of the wafer W due to the wrinkles 82. However, as described above, the case where the wafer W is heated by infrared rays irradiated from the heater 51 is irrelevant miss you. Therefore, in the fourth shrinking process of the wafer spacing process, the portion of the wrinkle 82 passing through the annular tape T that occurs between the outer periphery of the wafer W and the inner periphery of the ring frame F and the ring-shaped tape are depicted A pair of heaters 51 are moved in the rotation direction and the radial direction by the rotation means 52 and the radial advancement and retraction means 53 in the manner of the elliptical track 85 of the radial middle portion 83 of T.

In this case, the rotation means 52 is provided with an angle recognition part 65 that recognizes the rotation angle. The angle recognition unit 65 is controlled by the rotation control unit 72 (refer to FIG. 1 ), and the radial advance and retreat means 53 is controlled by the advance and retreat control unit 73 (refer to FIG. 1 ). The rotation angle of the heater 51 is recognized by the angle recognition unit 65, and the heater 51 is moved in the radial direction by the radial advancing and retreating means 53 in each angle range set in advance to heat the outer periphery of the wafer W and the inside of the ring frame F The endless tape T between the circumferences is heat-shrinked.

That is, the predetermined heating area of the ring-shaped tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F is performed by changing the position of the heater 51 in the radial direction within a predetermined angle range heating. In the angle range (heating area) θ1 where the tape T hardly shrinks, the pair of heaters 51 are brought close to each other by the radial advance and retreat means 53 under the control of the advance and retreat control section 73 (see FIG. 1). Directly above the portion of wrinkle 82, a pair of heaters 51 are positioned. Furthermore, in the angle range (heating area) θ2 where the tape T is easily thermally contracted, the pair of heaters 51 are separated from each other by the radial advance and retreat means 53 under the control of the advance and retreat controller 73 (see FIG. 1 ). The middle portion 83 of the outer periphery of W and the inner periphery of the ring frame F positions the heater 51. In this way, it is effective to change the heating position of the heater 51 in the heating area (angle range θ1, θ2) in the radial direction The tape T is thermally contracted to maintain the wafer interval of the divided wafer W.

In addition, the fourth shrinking process may be carried out after the holding table 10 and the ring-shaped frame holding portion 20 return to the same height, that is, after the tension of the tape T is completely relaxed. In addition, the fourth shrinking process may be performed while bringing the holding table 10 and the ring-shaped frame holding portion 20 close to one side. In addition, the fourth shrinking process may be carried out by approaching the holding table 10 and the ring-shaped frame holding portion 20 one step at a time as in the second division method.

As described above, if the wafer W division method according to this embodiment mode is used, the tape T is stretched by the distance between the holding table 10 and the ring-shaped frame holding portion 20, and the wafer W is on the modified layer 81 It is divided so that the wafers C are spaced apart. Further, when the tension of the tape T is released, wrinkles 82 are generated in the ring-shaped tape T between the outer periphery of the wafer W and the inner periphery of the ring frame F. At this time, the heating range of the tape T by the heater 51 is heated every time in a predetermined heating area in the circumferential direction or the radial direction. Therefore, compared to the case where the entire endless tape T is heated in the same manner, no large wrinkles 82 remain on the tape T. According to this, the wrinkle 82 can be removed from the tape T by a simple device configuration, and the divided wafer interval of the wafer W can be appropriately maintained.

In addition, the present invention is not limited to the above-mentioned embodiments, and can be implemented with various changes. In the above-described embodiment, the size or shape shown in the attachment drawing is not limited to this, and can be appropriately changed within the scope of exerting the effects of the present invention. Others can be implemented with appropriate changes as long as they do not deviate from the scope of the object of the present invention.

For example, the In the cutting process, the lowering of the ring-shaped frame holding portion 20 makes the holding table 10 and the ring-shaped frame holding portion 20 spaced apart, but it is not limited to this structure. In the division process, if the holding table 10 is in the ascending direction, the ring frame holding portion 20 is relatively moved in the lowering direction, and the holding table 10 and the ring frame holding portion 20 may be spaced apart. For example, even if the holding table 10 is raised, the holding table 10 and the ring frame holding portion 20 may be spaced apart.

In addition, in each of the division methods of the present embodiment described above, although the tension of the tape T when the tape T is pasted to the ring frame F is exemplified, the structure where the tape T becomes wrinkled is biased, but It is not limited to this structure. Even if the tape T around the wafer W has other factors, the wrinkle 82 may be biased, and the wrinkle 82 may not be biased. In addition, the place where the tape T becomes the wrinkle 82 is not specifically limited.

In addition, in each of the division methods of the present embodiment described above, although the lifting and lowering means 40 and the radial advancing and retracting means 53 are configured by electric cylinders, they are not limited to this configuration. The raising and lowering means 40 may be configured to move the holding table 10 and the ring-shaped frame holding portion 20 up and down relatively. In addition, the radial advancing and retracting means 53 may be configured to advance and retreat the heater 51 in the radial direction of the wafer W.

In addition, in each of the division methods of the above-described embodiment, an appropriate division method may be selected and implemented in accordance with the manner in which the wrinkle 82 generates the tape T. Furthermore, even if the third division method and the fourth division method are combined, the elliptical orbit is drawn by the heater 51, and the The rotation speed of the rotation means 52 can be adjusted. That is, in the angle range (heating area) where the tape T is hard to thermally shrink, the pair of heaters 51 are brought close to each other while the rotation speed of the rotating means 52 is reduced, and in the angle range (heating area) where the tape T is easily heat-shrinkable, even The pair of heaters 51 may be spaced from each other, and the rotation speed of the rotation means 52 may be increased at the same time.

In addition, in the first division method of the present embodiment described above, although the first shrinking process is performed when the holding table 10 and the ring-shaped frame holding portion 20 are approached, and the second shrinking process is performed after the approach, it is not limited to The composition. If the second contraction process is performed after the first contraction process, the second contraction process may be performed while the holding table 10 and the ring frame holding portion 20 are approaching.

In addition, in the third contraction process of the second division method of the present embodiment described above, the heater 51 may be moved in the radial direction every time the holding table 10 and the ring-shaped frame holding portion 20 approach.

In addition, in the approaching process of the second division method of the present embodiment described above, although it is constituted that the holding table 10 and the ring-shaped frame holding section 20 are approached step by step by a predetermined amount by the lifting means 40, However, the specified amount is not necessarily limited to a certain amount. For example, after approaching 3 mm and approaching 4 mm, it may be possible to approach in stages by different amounts.

[Industry use feasibility]

As described above, the present invention has an effect that the wrinkle can be removed from the tape with a simple device configuration, and the wafer interval can be properly maintained, especially The method and the device are favorable for dividing a semiconductor wafer or an optical device wafer.

10‧‧‧Retainer

15‧‧‧Roll Department

20‧‧‧ Ring frame holding part

21‧‧‧Placing table

22‧‧‧Cover

30‧‧‧Attraction

31‧‧‧ On-off valve

40‧‧‧lifting means

50‧‧‧The means of heat shrink

51‧‧‧ Heater

82‧‧‧Wrinkle

C‧‧‧chip

F‧‧‧ring frame

T‧‧‧ tape

W‧‧‧ Wafer

WS‧‧‧Workpiece group

R1, R2‧‧‧Heating area

Claims (6)

A dividing device is a heat shrinkable adhesive tape that sticks to the opening of a ring-shaped frame, and a wafer formed with a division starting point along a predetermined dividing line is adhered to the opening of the tape The tape is stretched, and the wafer is divided into wafers at the starting point of the division. The dividing device includes: a holding table that attracts and holds the wafer through the tape of the workpiece group; an annular frame holding portion, which is Holding the ring frame of the workpiece group; a pair of heaters, which heats the prescribed portion of the ring-shaped tape between the outer periphery of the wafer of the workpiece group and the inner periphery of the ring frame to make the crystal The center of the circle is arranged to face the center; the rotation means, which rotates a pair of the heaters with the center of the wafer as the axis; and the lifting means, which makes the holding table and the ring frame holding portion relative Up and down movement, with the holding table and the ring frame holding portion holding the workpiece group, the holding table is moved upward by the lifting means, and the ring frame holding portion is moved relative to the lower direction. And the space between the holding table and the ring frame holding portion is stretched, the tape is stretched, and the wafer is divided at the starting point of the division. The rotation means includes: an angle identification portion that recognizes the rotation angle; The speed of rotation of the heater can be adjusted while recognizing the angle of the angle recognition unit under the angle range set in advance The heating range of the heater for the ring-shaped adhesive tape between the outer periphery of the wafer and the inner periphery of the ring frame can be adjusted in the circumferential direction by the speed adjustment means, each The heating is performed in the prescribed heating area, and the tape is thermally contracted in the prescribed heating area each time to separate the wafers. A method of dividing a wafer, which is a method of dividing a wafer using a dividing device. The dividing device includes a holding table, which is a heat-shrinkable adhesive tape that plugs the opening of the ring frame and sticks A wafer formed with a dividing starting point adhered to the tape of the work group of the tape of the opening along the planned dividing line to attract and hold the wafer; a ring frame holding part that holds the ring frame of the work group ; A heater, which heats the prescribed portion of the ring-shaped tape between the outer periphery of the wafer of the workpiece group and the inner periphery of the ring frame; the rotation means, which uses the center of the wafer as the axis The heater rotates; and the lifting means, which makes the holding table and the ring-shaped frame holding portion perform a relative up and down motion, stretches the tape, and splits the wafer into a wafer at the splitting starting point, the wafer The dividing method is composed of the following works: a holding process, which holds the workpiece group on the holding table and the ring frame holding portion; a dividing process, which is to make the holding table by the lifting means after the holding process In the ascending direction, relative movement of the ring frame holding portion in the descending direction, and spacing the holding table and the ring frame holding portion, stretching the tape, and dividing the wafer at the starting point of division; and Wafer spacing process is to make the heating range of the heater for the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring frame in the circumferential direction after the dividing process, make the rotation speed The adjustment is performed by heating in a prescribed heating area each time, and the tape is thermally contracted to space the wafer. The method of dividing a wafer as described in claim 2, wherein the wafer spacing process is composed of the following process: a first shrinking process, which uses the lifting means to move the holding table in the lowering direction and the ring frame The holding portion moves relatively in the ascending direction, and the holding table and the ring-shaped frame holding portion are brought close, so that the tape of the ring shape between the outer circumference of the wafer and the inner circumference of the ring frame is applied One of the tension directions is orthogonal to the other direction, and the portion of the two wrinkles generated at the opposite side of the wafer is heated by a limited heat to shrink it; and the second shrinkage process, which is after the first shrinkage process, The heater is rotated by the rotating means and the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring-shaped frame is collectively heated and thermally contracted. The method of dividing a wafer as recited in claim 2, wherein the wafer separation process is composed of the following process: a proximity process, which is after the dividing process, the holding table and the ring frame are held by the lifting means The unit is approached step by step by a specified amount each time; and the third contraction process, which is to rotate the heater by the rotating means after the approach process and to make the outer periphery of the wafer and the inner periphery of the ring frame The tape of the ring is heated and heat-shrinked, The approaching process and the third contraction process are repeated until the holding table and the ring-shaped frame holding portion are closest. The method of dividing a wafer as described in claim 2, wherein the dividing device includes a radial advancing and retreating means for advancing and retreating the heater in the radial direction of the wafer, and the wafer spacing process is provided with a fourth shrinking process, which is described by By passing the elliptical orbit of the wrinkled portion of the ring-shaped tape that occurs between the outer periphery of the wafer and the inner periphery of the ring-shaped frame and the radial middle portion of the ring-shaped tape, with The rotating means and the radial advancing and retreating means move the heater to heat the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring frame and heat shrink it. The method of dividing a wafer as described in claim 4 or 5, wherein the rotation means includes: an angle recognition unit that recognizes the rotation angle; and a speed-adjustable means that enables the use of the next angle range set in advance The angle recognition part recognizes the angle so that the speed of the heater rotation can be adjusted. The wafer spacing process uses the angle recognition part to recognize the rotation angle of the heater, and the speed can be adjusted by means of the speed adjustable means under each angle range set in advance The rotation speed of the means can be adjusted, and the ring-shaped tape between the outer periphery of the wafer and the inner periphery of the ring-shaped frame is heated and heat-shrinked.

Images