JP7110540B2 - Work dividing device and work dividing method - Google Patents

Description

The present invention relates to a work dividing device and a work dividing method, and more particularly to a work dividing device and a work dividing method for dividing a work such as a semiconductor wafer into individual chips along a dividing line.

Conventionally, in the manufacture of semiconductor chips (hereinafter referred to as chips), a semiconductor wafer (hereinafter referred to as a wafer) in which division lines are formed in advance by half-cutting with a dicing blade or forming a modified region by laser irradiation is formed. ) into individual chips along the planned dividing line (see Patent Document 1, etc.).

15A and 15B are explanatory diagrams of a wafer unit 2 to which a disk-shaped wafer 1 to be divided by a work dividing device is attached. FIG. 15A is a perspective view of the wafer unit 2, and FIG. 4 is a cross-sectional view of the unit 2; FIG.

The wafer 1 is attached to the central portion of a dicing tape (also called expansion tape or adhesive sheet) 3 having a thickness of about 100 μm and having an adhesive layer formed on one side. It is fixed to a shaped frame (hereinafter referred to as frame) 4 .

In the work dividing apparatus, the frame 4 of the wafer unit 2 is fixed by a frame fixing member (also referred to as a frame fixing mechanism) 7 indicated by a two-dot chain line. Thereafter, an expand ring (also referred to as a push-up ring) 8 indicated by a chain double-dashed line is moved upward from below the wafer unit 2, and the expand ring 8 presses the dicing tape 3 and expands it radially. The tension of the dicing tape 3 generated at this time is applied to the dividing line 5 of the wafer 1 , thereby dividing the wafer 1 into individual chips 6 . The planned division lines 5 are formed in the X direction and the Y direction that intersect each other. Regarding the division lines 5, when the number of lines parallel to the X direction and the number of lines parallel to the Y direction are the same, and when the intervals in each direction are equal, the shape of the divided chip 6 becomes a square. . Also, when the number of chips parallel to the X direction is different from the number of chips parallel to the Y direction and the intervals in the respective directions are equal, the shape of the divided chips 6 is rectangular.

By the way, the dicing tape 3 is a flexible member having a low Young's modulus. Therefore, in order to smoothly divide the wafer 1 into individual chips 6, it is conceivable to cool the dicing tape 3 and expand the dicing tape 3 while increasing the spring constant of the dicing tape 3.

The tape expanding device (work dividing device) disclosed in Patent Document 2 includes cool air supply means. According to Patent Document 2, the dicing tape is cooled by activating the cool air supply means to supply cool air into the processing space and cooling the inside of the processing space to, for example, 0° C. or less.

On the other hand, in the chip dividing/separating device (work dividing device) of Patent Document 3, attention is paid to the fact that the dicing tape has anisotropy. It has a surface support mechanism. This film surface support mechanism includes a plurality of support mechanisms independent in the circumferential direction, and by individually controlling the relative heights of the plurality of support mechanisms to adjust the tension of the dicing tape, the X-axis of the dicing tape is adjusted. Directional elongation and Y-direction elongation are controlled independently.

Here, in the specification of the present application, of the dicing tape 3, a circular region in a plan view to which the wafer 1 is attached is referred to as a center region 3A, and between the outer edge of the center region 3A and the inner edge of the frame 4 A donut-shaped region in a plan view provided in the frame 4 is called an annular portion region 3B, and a donut-shaped region in a plan view of the outermost peripheral portion attached to the tape application surface 4A of the frame 4 is called a fixing portion region 3C. The annular region 3B is a region that is pressed and expanded by the expand ring 8 .

It should be noted that the force required to split the wafer 1, that is, the tension that must be generated in the annular region 3B to split the wafer 1, must be increased as the number of the splitting lines 5 increases. Are known. Regarding the number of dividing lines 5, for example, when the wafer 1 has a diameter of 300 mm and the chip size is 5 mm, approximately 120 dividing lines 5 (60 in each of the XY directions) are formed, and when the chip size is 1 mm. , approximately 600 division lines 5 are formed. Therefore, the tension that must be generated in the annular region 3B must be increased as the chip size becomes smaller.

JP 2016-149581 A JP 2016-12585 A Japanese Patent No. 5912274

By the way, the inner diameter (diameter of the inner edge of the frame) of the frame 4 on which the 300 mm diameter wafer 1 is mounted is defined as 350 mm by the SEMI standard (G74-0699 Specification for tape frames for 300 mm wafers). According to this standard, an annular region 3B having a width of 25 mm exists between the outer edge of the wafer 1 and the inner edge of the frame 4, as shown in the longitudinal sectional view of the wafer unit 2 in FIG. . 17(A) and 17(B), the frame fixing member 7 for fixing the frame 4 does not come into contact with the annular portion region 3B expanded by the expand ring 8. As shown in FIGS. As shown in FIG. 1, the dicing tape 3 is installed at a position spaced outwardly from the annular portion region 3B in the in-plane direction of the dicing tape 3 indicated by the arrow A. As shown in FIG.

Therefore, the forces for dividing the wafer 1 caused by the upward movement of the expand ring 8 are (i) a force for expanding the entire annular region 3B, (ii) a force for dividing the wafer 1 into chips 6, and (iii). The force that expands the dicing tape 3 between adjacent chips 6 is broken down into three forces.

As shown in FIGS. 18A to 18E, which are operation diagrams of the work dividing device, the expand ring 8 abuts against the annular region 3B of the dicing tape 3, and the expansion of the dicing tape 3 is started by the upward movement of the expand ring 8. Then (FIG. 18(A)), expansion of the annular region 3B having the lowest spring constant begins (FIG. 18(B)). As a result, tension is generated in the annular portion region 3B, and when this tension increases to some extent, the increased tension is transmitted to the wafer 1 and the wafer 1 begins to be divided into chips 6 (FIG. 18(C)). When the wafer 1 is divided into individual chips 6, the expansion of the annular region 3B and the expansion of the dicing tape 3 between the chips proceed simultaneously (FIGS. 18(D)-(E)).

In the conventional work dividing apparatus, if the wafer 1 has a diameter of 300 mm and the chip size is 5 mm or more, the tension generated in the annular region 3B can divide the wafer 1 into individual chips 6 without any problem. However, as circuit patterns formed on the wafer 1 become finer, chips with a smaller chip size of 1 mm or less have appeared. In this case, due to the increase in the number of dividing lines 5 for dividing the wafer 1, the force required to divide the wafer 1 increases, and a force greater than the tension due to the expansion of the annular region 3B is required. was there. Then, as shown in the longitudinal sectional view of the wafer unit 2 in FIG. 19, even after the expansion operation by the expand ring 8 is completed, part of the dividing line 5 formed on the wafer 1 remains undivided without being divided. A problem arose.

Such a problem of undivided lines 5 to be divided cannot be solved even by increasing the expansion amount and expansion speed of the dicing tape 3 . This is because, for example, when the expansion amount of the dicing tape 3 is increased, the annular region 3B begins to undergo plastic deformation. Since the spring constant of the annular portion region 3B during plastic deformation is smaller than the spring constant during elastic deformation, in the region beyond the elastic deformation of the annular portion region 3B, the tension for dividing the wafer 1 into individual chips 6 is does not occur. On the other hand, even if the expansion speed of the dicing tape 3 is increased, a portion of the annular portion region 3B begins to undergo plastic deformation, so the tension for dividing the wafer 1 into individual chips 6 is not generated. This is because the frequency response of the dicing tape 3 is low, so the force is not transmitted to the entire dicing tape 3 with no time difference.

In Patent Document 2, in order to solve the problem of undivided lines 5 to be divided, the dicing tape is cooled and the spring constant of the dicing tape is increased. sufficient effect cannot be obtained.

In addition, although the chip dividing/separating device of Patent Document 3 can independently control the X-direction elongation and the Y-direction elongation of the dicing tape, it applies a force greater than the tension caused by the expansion of the annular region to the wafer. Therefore, the problem of undivided lines to be divided cannot be solved.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and provides a work dividing apparatus and work dividing method capable of solving the problem of undivided lines to be divided that occurs when the chip size is a small chip. With the goal.

In order to achieve the object of the present invention, the work dividing apparatus of the present invention has the outer periphery of the dicing tape fixed to a ring-shaped frame having an inner diameter larger than the outer diameter of the work, and divides the work adhered to the dicing tape. In a work dividing device for dividing into individual chips along a planned dividing line, an opening arranged on the back side of the dicing tape opposite to the surface where the work is attached and smaller than the inner diameter of the frame and larger than the outer diameter of the work An expanding ring formed in a ring shape having a portion, and is moved in a direction relatively approaching the dicing tape, so that the annular portion between the outer edge of the work and the inner edge of the frame of the dicing tape An expand ring that presses and expands the area is arranged on the same side of the dicing tape as the surface where the workpiece is attached, and is formed into a ring shape having an opening that is smaller than the inner diameter of the frame and larger than the outer diameter of the expand ring. an expansion restricting ring for restricting expansion of an outer peripheral region located on the outer peripheral side of the contact portion in contact with the expansion restricting ring in the annular portion region; An expansion restriction ring moving mechanism for advancing and retreating between a restriction position for restricting expansion of a side area and a retracted position retracted from the restriction position, the extension restriction ring moving mechanism for adjusting the restriction position.

In one aspect of the present invention, it is preferable that the regulating position is a first regulating position on the same plane as the tape-attached surface of the frame to which the dicing tape is attached.

In one aspect of the present invention, the regulation position is preferably a second regulation position on the side where the expand ring is arranged with respect to the tape-applied surface of the frame to which the dicing tape is adhered.

One embodiment of the present invention is an expansion holding ring that is arranged on the back side of the dicing tape opposite to the surface on which the workpiece is attached, and that is formed into a ring shape and has an elastically deformable fitting portion that is larger than the inner diameter of the frame. an expansion holding ring that holds the expansion state of the dicing tape by engaging the fitting portion with the surface of the frame after the expansion regulation ring is moved from the regulation position to the retracted position by the expansion regulation ring moving mechanism; It is preferable to have

In order to achieve the object of the present invention, the work dividing method of the present invention comprises a ring-shaped frame having an inner diameter larger than the outer diameter of the work, and fixing the outer periphery of the dicing tape to the work. In the work dividing method for dividing the work into individual chips along the planned dividing line, an expand ring arranged on the back side of the dicing tape opposite to the work bonding surface is moved in a direction relatively approaching the dicing tape. an expanding step of pressing and expanding the annular region of the dicing tape between the outer edge of the work and the inner edge of the frame with the expanding ring; The expansion restricting ring arranged on the same side as the sticking surface is brought into contact with the annular portion region at the restricting position, and the outer peripheral region located on the outer peripheral side with respect to the abutting portion contacted by the expansion restricting ring. and an expansion regulation step for regulating expansion.

In one aspect of the present invention, it is preferable that the regulating position is a first regulating position on the same plane as the tape-attached surface of the frame to which the dicing tape is attached.

In one aspect of the present invention, the regulation position is preferably a second regulation position on the side where the expand ring is arranged with respect to the tape-applied surface of the frame to which the dicing tape is adhered.

In one embodiment of the present invention, by moving an expansion holding ring arranged on the back side of the dicing tape opposite to the surface on which the work is attached, in a direction relatively approaching the dicing tape, the outer periphery of the expansion holding ring is An expanded state holding step of holding an expanded state of the dicing tape by engaging an elastically deformable fitting portion formed in the portion with the surface of the frame.

According to the present invention, it is possible to solve the problem of undivided lines to be divided that occurs when the chip size is a small chip.

Principal part structural drawing of the work dividing apparatus of 1st Embodiment FIG. 2 is an enlarged perspective view of a main part of the work dividing device shown in FIG. 1; Enlarged cross-sectional view of essential parts of the wafer unit showing the shape of the annular region in the process of expansion Longitudinal cross-sectional view showing the expanded state of the dicing tape by the expansion retaining ring Enlarged cross-sectional view of essential parts in FIG. Block diagram showing the control system of the workpiece dividing device Flowchart showing an example of a wafer dividing method Operation explanatory diagram of the work dividing device Operation explanatory diagram of the work dividing device Structural drawing explaining another work dividing method by the work dividing device Enlarged cross-sectional view of essential parts of the wafer unit showing the shape of the annular region in the process of expansion Graph of calculated change in expansion ratio with respect to push-up amount Schematic diagram showing the operation during the expansion process Graph that calculates the change in expansion rate speed with respect to push-up speed Explanatory drawing of a wafer unit with wafers attached Longitudinal cross section of wafer unit Main part side view of work dividing device Operation diagram of work dividing device Longitudinal cross-sectional view of a wafer unit with divided wafers

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a work dividing device and a work dividing method according to the present invention will be described in detail below with reference to the accompanying drawings. The present invention is not limited to the following embodiments, and various modifications and replacements can be added to the following embodiments within the scope of the present invention.

FIG. 1 is a longitudinal sectional view of a main portion of a work dividing device 10 according to an embodiment, and FIG. 2 is an enlarged perspective view of a main portion of the work dividing device 10. As shown in FIG. Although the size of the wafer unit to be divided by the work dividing apparatus 10 is not limited, in the embodiment, the wafer unit 2 mounted with the wafer 1 having a diameter of 300 mm shown in FIG. 15 is exemplified.

As shown in FIG. 2, the work dividing device 10 divides the wafer 1 on which the dividing lines 5 are formed into individual chips 6 along the dividing lines 5 . A plurality of planned division lines 5 are formed in the X direction and the Y direction that are orthogonal to each other. In the embodiment, the number of planned division lines 5 parallel to the X direction and the number of planned division lines 5 parallel to the Y direction are 300, respectively, and the intervals between the wafers 1 are equal, that is, the chips having a chip size of 1 mm. A wafer 1 divided into 6 is illustrated.

The wafer 1 is attached to the central portion of the dicing tape 3 as shown in FIGS. The dicing tape 3 is attached (fixed) to the tape attaching surface 4A of the frame 4 at the fixing portion region 3C of the dicing tape 3. As shown in FIG. The dicing tape 3 has a circular center region 3A to which the wafer 1 is attached, and a donut shape between the outer edge of the center region 3A (the outer edge of the wafer 1) and the inner edge of the frame 4. has an annular portion region 3B of .

The thickness of the wafer 1 is, for example, about 50 μm. As the dicing tape 3, for example, a PVC (polyvinyl chloride) tape is used. The wafer 1 may be attached to the dicing tape 3 via a film adhesive such as DAF (Die Attach Film). As the film-like adhesive, for example, a PO (polyolefin)-based one can be used.

The workpiece dividing device 10 includes a frame fixing member 7 that fixes the frame 4, an expand ring 14 that presses the annular portion region 3B of the dicing tape 3 upward from below to expand the dicing tape 3, and the dicing tape 3. An expansion restricting ring 16 abutting on the annular region 3B from above, and an expansion holding ring 18 holding the expanded state of the dicing tape 3 expanded by the expand ring 14 are provided.

The frame fixing member 7 is arranged on the same side of the dicing tape 3 as the surface on which the wafer 1 is adhered, and the surface 4B of the frame 4 is fixed to the lower surface 7A thereof. In addition, the frame fixing member 7 is installed at a position spaced outward from the annular portion region 3B in the in-plane direction of the dicing tape 3 indicated by the arrow A so as not to contact the annular portion region 3B expanded by the expand ring 14. It is

As shown in FIG. 2, the shape of the frame fixing member 7 is a ring shape having an opening 7B with a diameter of, for example, 361 mm, which is larger than the inner diameter of the frame 4 (350 mm).

The expand ring 14 is arranged on the back side of the dicing tape 3 opposite to the bonding surface of the wafer 1, and is smaller than the inner diameter of the frame 4 (350 mm: see FIG. 16) and the outer diameter of the wafer 1 (300 mm: see FIG. 16). reference) has a larger expansion opening (opening) 14A. The expand ring 14 is arranged movably in a direction relatively approaching the dicing tape 3 . Specifically, the expand ring 14 has an expansion position (position indicated by a chain double-dashed line in FIG. 1 ) in which the back surface of the annular portion region 3B of the dicing tape 3 is pressed upward to expand the annular portion region 3B, and an annular It is arranged so as to be vertically movable between a retracted position (a position indicated by a solid line in FIG. 1) retracted downward from the lower region 3B.

The work dividing device 10 is provided with an expanding ring moving mechanism 20 for vertically moving the expanding ring 14 between an expanded position and a retracted position. A feed screw device is illustrated as an example of the expanding ring moving mechanism 20, but an actuator such as an air cylinder device can be used instead. When the expand ring 14 positioned at the retracted position is moved toward the expanded position by the expand ring moving mechanism 20, the expand ring 14 is moved upward in the arrow B direction toward the annular region 3B. As a result, the back surface of the annular portion region 3B is pressed against the expand ring 14 and expanded radially.

The expansion restricting ring 16 is arranged on the same side of the dicing tape 3 as the wafer 1 attachment surface, and is smaller than the inner diameter of the frame 4 (350 mm: see FIG. 15) and larger than the outer diameter of the expand ring 14. It has an opening (opening) 16B. As an example, the diameter of the expansion restricting opening 16B is 338 mm.

The expansion restricting ring 16 has a first restricting position (the position indicated by the two-dot chain line in FIG. 1) where the lower edge portion 16A abuts against the surface of the annular portion region 3B, and a retracted position retracted upward from the first restricting position. position (the position indicated by the solid line in FIG. 1) so as to be vertically movable.

The first regulating position is a position where expansion of the outer peripheral region 3E is regulated by the expansion regulating ring 16. In FIG. A first restriction position is set at a position located on the surface. Note that the outer peripheral region 3E is a region located on the outer peripheral side of the annular region 3B with the contact portion 3D contacting the lower edge portion 16A of the expansion restricting ring 16 as a boundary. Further, the area of the annular portion area 3B excluding the outer area 3E is the inner area 3F, and the inner area 3F is expanded by the expand ring 14. As shown in FIG.

The work dividing device 10 is provided with an expansion restricting ring moving mechanism 22 that vertically moves the expansion restricting ring 16 between the first restricting position and the retracted position. An air cylinder device is exemplified as an example of the expansion restricting ring moving mechanism 22, but an actuator such as a feed screw device can be used instead.

FIG. 3 is an enlarged cross-sectional view of the main part of the wafer unit 2 showing the shape of the annular region 3B that is being expanded by the expand ring 14. As shown in FIG.

As shown in FIG. 3, when the annular region 3B is expanded by the expand ring 14, the expansion restricting ring 16 is positioned at the first restricting position prior to the expanding operation by the expand ring 14. As shown in FIG. In other words, the expansion of the outer peripheral region 3E of the dicing tape 3 is restricted by the extension restriction ring 16 in advance. Therefore, according to the work dividing device 10 of the embodiment, expansion of the inner peripheral side region 3F starts immediately after the expand ring 14 comes into contact with the annular portion region 3B.

In the embodiment, as shown in FIG. 1, the diameter of the expansion restricting opening 16B is set to 338 mm, so the width of the outer peripheral region 3E, whose expansion is restricted by the expansion restricting ring 16, is set to 6 mm. The width dimension of the inner peripheral region 3F expanded by the ring 14 is set to 19 mm.

Here, of the annular portion region 3B, the inner peripheral side region 3F expanded by the expand ring 14 becomes a region that substantially contributes to the division of the wafer 1. As shown in FIG. Since the spring constant of the inner peripheral region 3F increases as the width dimension of the inner peripheral region 3F decreases, the tension applied to the wafer 1 from the inner peripheral region 3F increases. Therefore, the diameter of the expansion restricting opening 16B, which determines the width of the inner peripheral region 3F, is set according to the division conditions defined by the number of division lines 5 and the like.

On the other hand, the expansion holding ring 18 for holding the expanded state of the dicing tape 3 is arranged on the back side of the dicing tape opposite to the surface where the wafer 1 is attached. The expansion holding ring 18 is attached to a body ring 28 whose outer diameter is smaller than the inner diameter (350 mm) of the frame 4 and larger than the outer diameter of the expand ring 14, and the outer periphery of the body ring 28. and an elastically deformable ring-shaped fitting portion 30 having a diameter (351.3 mm) larger than the inner diameter (350 mm) of the frame 4 .

FIG. 4 is a sectional view showing the expanded state of the dicing tape 3 held by the expansion holding ring 18. As shown in FIG. FIG. 5 is an enlarged cross-sectional view of a main part of FIG.

As shown in FIGS. 4 and 5, the fitting portion 30 of the extended holding ring 18 is fitted to the surface 4B of the frame 4 via the annular portion region 3B of the dicing tape 3 at the fitting position indicated by the solid line. As a result, the expanded state of the dicing tape 3 is held by the expansion holding ring 18 .

The expansion holding ring 18 is on standby at a standby position (the position shown by the solid line in FIG. 1) below the fitting position indicated by the solid lines in FIGS. to the mating position.

The work dividing device 10 is provided with an extension holding ring moving mechanism 32 (see FIG. 1) for vertically moving the extension holding ring 18 between the standby position and the fitting position. A feed screw device is exemplified as an example of the extension holding ring moving mechanism 32, but instead of this, an actuator such as an air cylinder device can be used.

When the extension retaining ring 18 is lifted by the extension retaining ring moving mechanism 32 , the fitting portion 30 contacts the lower surface of the frame 4 . After that, the fitting portion 30 is pushed by the inner peripheral surface of the frame 4 and rises while being elastically deformed. As a result, the expanded state of the dicing tape 3 is maintained.

Returning to FIG. 1, the expanding ring moving mechanism 20, the expansion restricting ring moving mechanism 22, and the expanding holding ring moving mechanism 32 are controlled by a control unit 34 that controls the workpiece dividing device 10 as shown in the control system block diagram of FIG. Its operation is controlled. The control unit 34 has a CPU (Central Processing Unit) and a RAM (Random Access Memory), and the RAM stores the expanding ring moving mechanism 20, the expansion restricting ring moving mechanism 22, and the expanding retaining ring moving mechanism 32 in a predetermined order. A program is stored to operate the

Next, an example of control of each mechanism by the control unit 34 will be described based on the flowchart of FIG. to explain.

First, in the arrangement step (S100) of FIG. 7, the expand ring 14 and the expansion restricting ring 16 are arranged at the retracted positions, and the expansion holding ring 18 is arranged at the standby position, as shown in FIG. 8(A).

7, the frame 4 of the wafer unit 2 is fixed to the frame fixing member 7 as shown in FIG. 8B.

Next, in the expansion restricting step (S120) of FIG. 7, the expansion restricting ring 16 is moved from the retracted position to the first restricting position as shown in FIG. 8(C).

Next, in the expansion start step (S130) in FIG. 7, as shown in FIG. 8D, the expand ring 14 is moved upward from the retracted position shown in FIG. Expansion begins.

In this expansion start step (S130), the lower edge portion 16A of the expansion restricting ring 16 is previously brought into contact with the surface of the annular portion region 3B to restrict the expansion of the outer peripheral region 3E, so that the inner peripheral region 3F is expanded. It is expanded by the expanding ring 14 . Further, the expansion restriction step (S120) described above is a step that is performed together with the expansion step from the expansion start step (S130) to the end of the division step (S140) described later. In other words, the expansion step of the present invention refers to the steps from the expansion start step (S130) to the end of the division step (S140).

Next, in the dividing step (S140) in FIG. 7, as shown in FIG. 9A, the expansion ring 14 is moved upward to continue expanding the inner peripheral region 3F, and during this time the wafer 1 is sequentially divided into individual chips 6. split up. After that, as shown in FIG. 9B, when the expand ring 14 reaches the expanded position, the upward movement of the expand ring 14 is stopped. At this point, the extension process described above ends.

In such an expansion process, only the inner peripheral region 3F is expanded by the expand ring 14 while the expansion of the outer peripheral region 3E is restricted by the expansion restricting ring 16 . That is, the tension generated in the inner peripheral region 3</b>F is applied to the wafer 1 .

More specifically, in the expansion step, the expansion restricting ring 16 having the expansion restricting opening 16B with a diameter of 338 mm is used so that the length of the area contributing to the division of the wafer 1 is 25 mm (the annular area 3B is width) to 19 mm (the width of the inner peripheral region 3F). Therefore, the spring constant of the inner peripheral region 3F is increased, and tension corresponding to the increased spring constant is applied to the wafer 1 .

Therefore, according to the work dividing method of the embodiment, since the expansion restricting step (S120) is provided, even if the chip size is a small chip (1 mm), the wafer 1 is applied with enough tension to divide it into individual chips 6. can be granted. Therefore, it is possible to solve the problem of undivided lines to be divided that occurs when the chip size is a small chip (1 mm).

Next, when the dividing step (S140) in FIG. 7 is finished, in the expansion restricting ring retreating step (S150) in FIG. 7, the expansion restricting ring 16 is moved to the retracted position as shown in FIG. 9(C).

Next, in the extended state holding step (S160) in FIG. 7, as shown in FIG. 4B. As a result, the expanded state of the dicing tape 3 is held by the expansion holding ring 18 .

As described above, in the work dividing method of the embodiment, after the expansion step is performed, the expansion restricting ring retreating step (S150) is performed, and after the expansion restricting ring retracting step (S150) is performed, the extended state holding step ( S160) is performed.

Next, in the expanding ring retracting step (S170) in FIG. 7, the expanding ring 14 is moved downward to return to the retracted position as shown in FIG. 9(D). At this time, the dicing tape 3 is held in the expanded state by the expansion holding ring 18 without loosening. As a result, it is possible to prevent the chips 6 from coming into contact with each other due to loosening of the extended dicing tape 3, so that deterioration of the quality of the chips 6 can be prevented.

As described above, according to the work dividing method of the embodiment, it is possible to solve the problem that the line to be divided is not divided, which occurs when the chip size is a small chip, and also to solve the problem of deterioration in chip quality caused by contact between chips after division. can also be deleted.

Further, according to the work dividing method of the embodiment, the expansion of the outer peripheral region 3E is regulated by the expansion regulating ring 16 in the expansion process. Therefore, the dicing tape 3 in the outer peripheral region 3E is not stretched, and its original thickness is maintained. As a result, even when the expansion holding ring 18 is attached to the frame 4 with the outer peripheral region 3E stretched in the expanded state holding step (S160), the outer peripheral region 3E can be prevented from tearing.

In addition, in a process after the dividing process (S140), a thermal contraction process may be performed in which the loosened inner peripheral region 3F after expansion is thermally contracted by light heating and tensed again. By performing such a heat shrinking process, the inner peripheral region 3F can be tensed again, so there is an effect that the wafer unit 2 can be easily processed in the process after the dividing process (S140).

Moreover, it is preferable to previously cool the inner peripheral side region 3F to a low temperature by a cooling means (not shown) in a process prior to the expansion start process (S130) in FIG. As a result, the spring constant of the inner peripheral region 3F can be increased prior to the expansion start step (S130). Examples of the cooling means include a contact type that cools by contacting the inner peripheral side region 3F, and an air cooling type that cools by injecting cold air to the inner peripheral side region 3F.

In addition, it is preferable that the lower edge portion 16A of the expansion restricting ring 16 be surface-processed so as to have an arithmetic mean roughness (Ra) of 1.6 (μm), for example. As a result, a suitable frictional force is generated between the lower edge portion 16A and the annular portion region 3B, and this frictional force prevents the lower edge portion 16A and the annular portion region 3B from sliding relative to each other. can.

Further, the edge of the lower edge portion 16A of the expansion restricting ring 16 is preferably chamfered with C0.2 as an example. Thereby, it is possible to prevent the annular portion region 3B from being torn by the edge of the lower edge portion 16A.

Next, another work dividing method by the work dividing device 10 will be described.

FIG. 10 shows a structural diagram of a work dividing device 10 for explaining another work dividing method. Also, FIG. 11 shows an enlarged cross-sectional view of the main part of the wafer unit 2 showing the shape of the annular region 3B in the middle of expansion by another work dividing method.

10 and 11 with respect to the work dividing method shown in FIGS. 8 and 9 is that the restricting position of the expansion restricting ring 16 is set higher than the first restricting position. The point is that it is changed to the second regulation position on the side. Such regulation position adjustment is performed by the extension regulation ring moving mechanism 22 shown in FIG.

According to the work dividing method shown in FIGS. 10 and 11, prior to the expanding operation of the expand ring 14, the surface of the annular portion region 3B is previously pressed by the lower edge portion 16A of the expansion restricting ring 16. The side region 3F is expanded in advance by the expansion restricting ring 16. - 特許庁

In this way, by expanding the inner peripheral region 3F in advance, the amount of expansion (tension) of the inner peripheral region 3F when the amount of push-up of the annular portion region 3B is the same is as shown in FIGS. It can be increased more than the work division method. In other words, according to the work dividing method shown in FIGS. 10 and 11, the amount of pushing up is smaller than that of the work dividing method of FIGS. tension) can be obtained.

In the graph of FIG. 12, the vertical axis indicates the expansion rate (%) of the dicing tape 3, and the horizontal axis indicates the push-up amount (mm) of the annular region 3B due to the upward movement of the expand ring 14. As shown in FIG. In addition, FIG. 12 shows that the expansion rate corresponding to the amount of push-up differs for each regulation position of the expansion regulation ring 16, as will be described later.

More specifically, line A in FIG. 12 indicates changes in expansion rate when the expansion restricting ring 16 is set to the first restricting position (see FIG. 8C). A line B indicates a change in expansion rate when the expansion restricting ring 16 is set to the second restricting position (see FIG. 11).

A line C indicates a change in expansion rate when the expansion restricting ring 16 is set to the third restricting position. The third restricting position is a position closer to the expansion restricting ring 16 than the first restricting position. Line C shows the change in expansion rate when three restricting positions are set. Line D indicates the change in expansion rate when the expansion restriction ring 16 is not used.

Note that the graph shown in FIG. 12 is an example of expansion rates calculated based on the dimensions of each member shown in FIG.

That is, in this example, as shown in FIG. 13, the inner diameter D1 of the frame 4 is 350 mm, the thickness t of the frame 4 is 1.5 mm, the diameter D2 of the expansion restricting opening 16B of the expansion restricting ring 16 is 338 mm, and the roller 36 has an arrangement diameter D3 of 323.2 mm. The expansion ratios of lines A, B, and C shown in FIG. It is calculated. 13 indicates the amount (mm) of push-up of the annular portion region 3B by the upward movement of the expand ring 14. As shown in FIG.

Hereinafter, based on FIG. 12, the change of each expansion rate according to the restriction position of the extension restriction ring 16 will be described.

First, when the expansion restricting ring 16 is in the third restricting position (see line C), the upward movement of the expand ring 14 causes the annular portion region 3B to be pushed up, and the amount of thrust is 1.5 mm (=thickness of frame 4). When reaching t), the annular region 3B contacts the lower edge 16A of the expansion restricting ring 16. As shown in FIG. The expansion rate immediately after the contact becomes higher than the expansion rate when the expansion restriction ring 16 is not applied (see line D).

On the other hand, when the restricting position of the expansion restricting ring 16 is set to the first restricting position (see line A), the lower edge portion 16A of the expansion restricting ring 16 is positioned in the annular region 3B prior to the expansion operation. Since it is in contact with the surface in advance, the expansion rate immediately after the expand ring 14 comes into contact with the annular portion region 3B is higher than the expansion rate (see line C) at the third restricting position.

Further, when the restricting position of the expansion restricting ring 16 is set to the second restricting position (see line B), the lower edge portion 16A of the expansion restricting ring 16 presses the annular portion region 3B in advance prior to the expanding operation. Therefore, the expansion rate exceeds 0% even before the expansion operation is started. For this reason, the expansion rate when the amount of push-up of the annular region 3B is the same is higher than the expansion rate (see line A) when set at the first restriction position.

In this way, when the expansion restricting ring 16 is not applied, the annular portion region 3B is expanded using the expand ring 14 while the expansion restricting ring 16 is placed at one of the first to third restricting positions. Sufficient tension is obtained to divide the wafer 1 into chips 6 compared to . In particular, when the expansion restricting ring 16 is arranged at the first restricting position on the same plane as the tape applying surface 4A or at the second restricting position on the side of the tape applying surface 4A where the expand ring 14 is arranged, the tape applying A higher tension can be obtained immediately after the expand ring 14 is lifted, compared with the case where the expansion restricting ring 16 is arranged at the third restricting position on the side of the surface 4A, so that the wafer 1 can be moved more effectively. It can be divided into chips 6.

FIG. 14 shows changes in the rate of increase per unit time of each expansion rate (%) of lines A, B, C, and D shown in FIG. 12 (hereinafter referred to as expansion rate speed (%/sec)). is a graph.

In the graph of FIG. 14 , the expansion rate speed (%/sec) is shown on the left vertical axis, and the push-up speed (mm/sec) of the annular portion region 3B is shown on the right vertical axis. The horizontal axis indicates the amount of thrust (mm) of the partial region 3B.

FIG. 14 shows, as an example, changes in expansion rate speed when the pushing speed of the annular portion region 3B is constant. The faster the expansion rate, the higher the tension generated in the dicing tape 3 and the force for dividing the wafer 1 into chips 6 .

Line E in FIG. 14 indicates changes in thrust speed for thrust amounts from 0.00 mm to 20.00 mm. In other words, line E indicates the upward moving speed of the expand ring 14 . According to line E, the expand ring 14 moves upward at a constant speed (200 mm/sec) within the range of 0.00 mm to approximately 18.50 mm, and thereafter moves upward to 20.00 mm while decelerating.

Line F in FIG. 14 shows the change in dilation rate speed corresponding to the dilation rate of line D in FIG. Line G indicates the change in dilation rate speed corresponding to the dilation rate of line C in FIG. Line H indicates the change in dilation rate speed corresponding to the dilation rate of lines A and B in FIG.

According to the respective expansion rate speeds shown by lines F, G, and H in FIG. , and then descend respectively.

Here, when the restriction position by the expansion restricting ring 16 is set to the third restricting position (see line G), the expansion rate speed after the thrust amount exceeds about 3.00 mm is applied to the expansion restricting ring 16. It is faster than without it (see line F) and the maximum dilatation rate increases (increases from about 95%/sec to about 115%/sec). As a result, the tension generated in the dicing tape 3 is increased more than the tension in the case where the expansion restricting ring 16 is not applied, so that the above-described problem of undivided tape can be resolved.

On the other hand, when the expansion regulating ring 16 is set at the first regulating position or the second regulating position (see line H), the expansion rate speed when the thrust amount of the annular portion region 3B is the same is set at the third regulating position. (see line G). Note that the increase in the maximum expansion rate speed is substantially equal to that in the case of setting to the third restricting position (see line G).

By setting the expansion restricting ring 16 to the first restricting position or the second restricting position in this manner, the expansion rate (see FIG. 12) and the maximum expansion rate speed when the thrust amount of the annular portion region 3B is the same. (See FIG. 14) is faster than when set to the third regulating position, so a large tension can be applied to the wafer 1 immediately after the start of expansion. Therefore, the above-described undivided problem can be solved more effectively than when it is set to the third position.

In the other dividing method shown in FIGS. 10 and 11, the position moved 3 mm from the first regulating position to the side where the expand ring 14 is arranged is set as the second regulating position. It is not limited to positions. The second regulation position is preferably set at a position where optimal tension can be applied to wafers of various chip sizes with a small thrust amount. Further, the third restricting position is not limited to a position on the same plane as the surface 4B of the frame 4, and may be any position on the side where the expansion restricting ring 16 is arranged relative to the first restricting position.

DESCRIPTION OF SYMBOLS 1... Wafer, 2... Wafer unit, 3... Dicing tape, 3A... Central area, 3B... Annular area, 3C... Fixed part area, 3D... Contact part, 3E... Outer peripheral area, 3F... Inner peripheral area 4 Frame 4A Tape application surface 5 Division line 6 Tip 7 Frame fixing member 8 Expanding ring 14 Expanding ring 16 Expansion restricting ring 18 Expansion holding ring 20 ... Expanding ring moving mechanism, 22 ... Expansion restricting ring moving mechanism, 28 ... Body ring, 30 ... Fitting portion, 32 ... Expansion holding ring moving mechanism, 34 ... Control section, 36 ... Roller

Claims (6)

A work dividing device, wherein the outer periphery of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than the outer diameter of the work, and the work adhered to the dicing tape is divided into individual chips along division lines. ,
An expand ring arranged on the back side of the dicing tape opposite to the surface on which the work is adhered, and formed into a ring shape having an opening smaller than the inner diameter of the frame and larger than the outer diameter of the work. The expander presses and expands an annular region of the dicing tape between the outer edge of the workpiece and the inner edge of the frame by moving in a direction relatively approaching the dicing tape. a ring;
An expansion restricting ring arranged on the same side of the dicing tape as the surface on which the workpiece is attached, and formed in a ring shape having an opening smaller than the inner diameter of the frame and larger than the outer diameter of the expand ring, wherein the expansion restricting ring for restricting the expansion of an outer peripheral area located on the outer peripheral side of the contact portion in the annular portion area that is in contact with the expansion restricting ring;
an expansion restriction ring moving mechanism that advances and retracts the expansion restriction ring between a restriction position that restricts the expansion of the outer peripheral region and a retracted position retracted from the restriction position;
An expansion holding ring formed in a ring shape and having an elastically deformable fitting portion larger than an inner diameter of the frame, the expansion holding ring being disposed on the back side of the dicing tape opposite to the surface where the workpiece is attached, wherein the expansion holding ring An expansion holding ring for holding the expansion state of the dicing tape by moving the expansion regulation ring from the regulation position to the retracted position by a regulation ring moving mechanism and fitting the fitting portion onto the surface of the frame. When,
A workpiece dividing device. The regulating position is a first regulating position on the same surface as the tape attachment surface of the frame to which the dicing tape is attached.
The work dividing device according to claim 1. The regulating position is a second regulating position on the side where the expanding ring is arranged with respect to the tape-attached surface of the frame to which the dicing tape is attached.
The work dividing device according to claim 1. A work dividing method in which the outer periphery of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than the outer diameter of the work, and the work adhered to the dicing tape is divided into individual chips along dividing lines. ,
By moving an expand ring arranged on the back surface side of the dicing tape opposite to the bonding surface of the work in a direction relatively approaching the dicing tape, the outer edge portion of the work on the dicing tape an expanding step of pressing and expanding the annular portion region between and the inner edge portion of the frame with the expanding ring;
When the expansion step is performed, an expansion restricting ring arranged on the same side of the dicing tape as the work adhering surface and the annular portion region are brought into contact with each other at a restricting position to abut against the expansion restricting ring. an expansion restricting step of restricting the expansion of the outer peripheral region located on the outer peripheral side with the contact portion as a boundary;
The expansion regulating ring is moved from the regulating position to the retracted position, and the expansion holding ring arranged on the back side of the dicing tape opposite to the surface where the work is adhered is moved relatively closer to the dicing tape. an expanded state holding step of holding the expanded state of the dicing tape by moving the elastically deformable fitting portion formed on the outer peripheral portion of the expansion holding ring in the direction to fit the surface of the frame;
A work division method comprising: The regulating position is a first regulating position on the same surface as the tape attachment surface of the frame to which the dicing tape is attached.
5. The work dividing method according to claim 4 . The regulating position is a second regulating position on the side where the expanding ring is arranged with respect to the tape-attached surface of the frame to which the dicing tape is attached.
5. The work dividing method according to claim 4 .

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