JP2021129123A - Workpiece division method - Google Patents

Abstract

To provide a workpiece division method that can solve the problem of undivided lines scheduled to be divided that occurs when a chip size is small.SOLUTION: When the rate of increase per unit time in the expansion rate of a dicing tape is defined as the expansion rate speed, an expansion division condition setting process sets the expansion band ring thrust speed as an expansion division condition so that the maximum expansion rate speed is maintained for a certain period of time in the expansion division process.SELECTED DRAWING: Figure 10

Description

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

Conventionally, in the manufacture of a semiconductor chip (hereinafter referred to as a chip), a semiconductor wafer (hereinafter referred to as a wafer) in which a planned division line is formed in advance by half-cutting with a dicing blade or forming a modified region by laser irradiation. ) Is known as a work dividing device that divides) into individual chips along a planned division line (see Patent Document 1 and the like).

12A and 12B are explanatory views of a wafer unit 2 to which a disk-shaped wafer 1 to be divided by a work dividing device is attached, FIG. 12A is a perspective view of the wafer unit 2, and FIG. 12B is a wafer. It is a vertical sectional view of a unit 2.

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

In the work dividing device, the frame 4 of the wafer unit 2 is brought into contact with and fixed to the frame fixing member (also referred to as a frame fixing mechanism) 7 indicated by the alternate long and short dash line. After that, the expanding ring (also referred to as a push-up ring) 8 indicated by the alternate long and short dash line is pushed up (raised) from below the wafer unit 2, and the dicing tape 3 is pushed up by the expanding ring 8 and expanded radially. .. The tension of the dicing tape 3 generated at this time is applied to the scheduled division line 5 of the wafer 1, so that the wafer 1 is divided into individual chips 6. The planned division lines 5 are formed in the X and Y directions orthogonal to each other. When the number of lines parallel to the X direction and the number of lines parallel to the Y direction are the same for the planned division line 5, and the intervals in the respective directions are equal, the shape of the divided chips 6 becomes a square. .. Further, when the number of chips parallel to the X direction and the number of chips parallel to the Y direction are different and the intervals in the respective directions are equal, the shape of the divided chips 6 becomes 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 in a state where the spring constant of the dicing tape 3 is increased.

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

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

Here, in the specification of the present application, the region of the dicing tape 3 having a circular shape in a plan view to which the wafer 1 is attached is referred to as a central region 3A, and the outer edge portion of the central region 3A and the inner edge portion 4A of the frame 4 are referred to. The plan-view donut-shaped region provided between them is referred to as an annular portion region 3B, and the plan-view donut-shaped region of the outermost peripheral portion fixed to the frame 4 is referred to as a fixed portion region 3C. The annular portion region 3B is a region that is pushed up by the expanding ring 8 and expanded.

The force required to divide the wafer 1, that is, the tension that must be generated in the annular portion region 3B to divide the wafer 1, must be increased as the number of planned division lines 5 increases. Are known. Regarding the number of planned division lines 5, for example, when the wafer 1 having a diameter of 300 mm has a chip size of 5 mm, about 120 planned division lines (60 lines each in the XY direction) are formed, and the chip size is 1 mm. Is formed with about 600 scheduled division lines 5. Therefore, the tension that must be generated in the annular portion region 3B must be increased as the chip size becomes smaller.

Japanese Unexamined Patent Publication No. 2016-149581 Japanese Unexamined Patent Publication No. 2016-12585 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 wafer 1 having a diameter of 300 mm is mounted is defined as 350 mm by the SEMI standard (specification for a tape frame for a G74-0699 300 mm wafer). According to this standard, as shown in the vertical cross-sectional view of the wafer unit 2 of FIG. 13, an annular portion region 3B having a width dimension of 25 mm exists between the outer edge portion of the wafer 1 and the inner edge portion of the frame 4. .. Further, as shown in the vertical cross-sectional view of the main part of the work dividing device shown in FIGS. 14A and 14B, the frame fixing member 7 for fixing the frame 4 does not come into contact with the annular portion region 3B expanded by the expanding ring 8. As described above, the dicing tape 3 indicated by the arrow A is installed at a position separated outward from the annular portion region 3B in the in-plane direction.

Therefore, the force for dividing the wafer 1 generated by the pushing operation of the expanding ring 8 is (i) a force for expanding the entire region of the annular portion region 3B, (ii) a force for dividing the wafer 1 into chips 6, and (iii). It is decomposed into three forces that expand the dicing tape 3 between the adjacent chips 6.

As shown in the operation diagram of the work dividing device shown in FIGS. 15A to 15E, the expanding ring 8 abuts on the annular portion region 3B of the dicing tape 3, and the expansion of the dicing tape 3 is started by the pushing-up operation of the expanding ring 8. (FIG. 15 (A)), the expansion of the annular portion region 3B having the lowest spring constant begins (FIG. 15 (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. 15 (C)). When the wafer 1 is divided into individual chips 6, the expansion of the annular portion region 3B and the expansion of the dicing tape 3 between the chips proceed at the same time (FIGS. 15D to 15E).

In the conventional work dividing device, when the chip size is 5 mm or more in the wafer 1 having a diameter of 300 mm, the individual chips 6 can be divided without any problem due to the tension generated in the annular portion region 3B. However, with the miniaturization of the circuit pattern formed on the wafer 1, chips having a smaller chip size of 1 mm or less have appeared. In this case, when the number of scheduled division lines 5 for dividing the wafer 1 increases, the force required for dividing the wafer 1 increases, and a force greater than the tension due to the expansion of the annular portion region 3B is required. was there. Then, as shown in the vertical cross-sectional view of the wafer unit 2 of FIG. 16, even if the expansion operation by the expanding ring 8 is completed, a part of the planned division line 5 formed on the wafer 1 is not divided and remains undivided. There was a problem of doing.

Such an undivided problem of the scheduled division line 5 cannot be solved by increasing the expansion amount and expansion speed of the dicing tape 3. For example, when the expansion amount of the dicing tape 3 is increased, the annular portion region 3B starts plastic deformation. Since the spring constant of the annular portion region 3B during plastic deformation is smaller than the spring constant during elastic deformation, the tension for dividing the wafer 1 into individual chips 6 in the region exceeding the elastic deformation of the annular portion region 3B is high. Does not occur. On the other hand, even when the expansion speed of the dicing tape 3 is increased, a part of the annular portion region 3B starts to be plastically deformed, so that the tension for dividing the wafer 1 into the individual chips 6 is not generated. This is because the frequency response of the dicing tape 3 is low, so that the force is not transmitted to the entire dicing tape 3 without a time lag.

In order to solve the problem of undivided line 5 to be divided, Patent Document 2 deals with this by cooling the dicing tape and increasing the spring constant of the dicing tape, but for small chips of 1 mm or less in recent years. It is not possible to obtain a sufficient effect.

Further, the chip dividing / separating device of Patent Document 3 can independently control the elongation of the dicing tape in the X direction and the elongation in the Y direction, but exerts a force on the wafer 1 that is greater than the tension due to the expansion of the annular portion region 3B. Since it cannot be assigned, the problem of undivided lines to be divided cannot be solved.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a work dividing method capable of solving the undivided problem of the scheduled division line that occurs when the chip size is a small chip. ..

In the work dividing method of the present invention, in order to achieve the object of the present invention, the outer peripheral portion of the dicing tape is fixed to a ring-shaped frame having an inner diameter larger than the outer diameter of the work, and the work attached to the dicing tape is divided. A work dividing method for dividing into individual chips along a planned line, using an expanding ring formed in a ring shape having an opening smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the work. In the work division method in which the back surface of the dicing tape opposite to the sticking surface of the work is pushed up toward the sticking surface, the dicing tape is formed into a ring shape having an opening smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the expanding ring. An arrangement step of arranging one expansion regulation ring selected from a plurality of expansion retention rings having different opening diameters on the same side as the sticking surface of the work in the dicing tape, and dicing. The back side of the dicing tape is pushed up by the expanding ring to expand the dicing tape at the expansion division condition setting process that sets the push-up amount and push-up speed of the expanding ring with respect to the tape, and the push-up amount and push-up speed set by the expansion division condition setting process. The dicing tape is brought into contact with the expansion regulation ring to divide the work into individual chips when the dicing tape is expanded, and the expansion division condition setting process includes an expansion division condition setting process in which the diameter of the opening is large. The push-up amount is set based on the target expansion rate of the dicing tape after expansion corresponding to each of a plurality of different expansion regulation rings.

In one aspect of the present invention, in the expansion division condition setting step, it is preferable to set the push-up amount to be smaller as the diameter of the opening of the expansion regulation ring becomes smaller.

In one aspect of the present invention, when the rate of increase of the expansion rate of the dicing tape per unit time is defined as the expansion rate rate, the expansion division condition setting step is such that the maximum expansion rate rate is maintained for a certain period of time in the expansion division process. , It is preferable to set the push-up speed.

According to the present invention, it is possible to solve the undivided problem of the scheduled division line that occurs when the chip size is a small chip.

Structural drawing of the main part of the division stage of the work division device Enlarged perspective view of the main part of the split stage shown in FIG. Explanatory drawing showing a modified example of the extended regulation ring Cross-sectional view of the wafer unit showing the shape of the annular region during expansion Flow chart showing an example of wafer division method Flow chart showing another example of the wafer division method Graph that calculated the change of expansion rate with respect to the amount of push-up Schematic diagram showing the operation during the expansion division process Graph that calculated the change of expansion rate speed with respect to push-up speed Graph that calculated the change of expansion rate speed with respect to push-up speed Flowchart of work division method including extended division condition setting process Explanatory drawing of the wafer unit to which the wafer is attached Longitudinal section of the wafer unit Side view of the main part of the work dividing device Operation diagram of work dividing device Longitudinal section of the wafer unit in which the wafer is divided

Hereinafter, preferred embodiments of the work dividing method according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments, and various modifications and substitutions can be added to the following embodiments within the scope of the present invention.

FIG. 1 is a vertical cross-sectional view of a main part of the division stage provided in the work division device 10, and FIG. 2 is an enlarged perspective view of the main part of the division stage. The size of the wafer unit to be divided by the work dividing device 10 is not limited, but in the embodiment, the wafer unit 2 on which the wafer 1 having a diameter of 300 mm shown in FIG. 13 is mounted is illustrated.

The work dividing device 10 is a device that divides the wafer 1 into individual chips 6 along the scheduled division line 5. A plurality of scheduled division lines 5 are formed in the X direction and the Y direction 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, and the intervals are the same. Wafer 1, that is, a chip having a chip size of 1 mm. An example is a wafer 1 divided into 6.

As shown in FIGS. 1 and 2, the wafer 1 is attached to the central portion of the dicing tape 3 whose outer peripheral portion is fixed to the frame 4. The dicing tape 3 has a plan-view circular central region 3A to which the wafer 1 is attached, and a plan-view donut-shaped annular region 3B between the outer edge of the central region 3A and the inner edge of the frame 4. ..

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

The work dividing device 10 includes a frame fixing member 7 (see FIG. 14: an existing frame fixing member) for fixing the frame 4, an expansion regulating ring 16 with which the dicing tape 3 is brought into contact with the dicing tape 3 when the dicing tape 3 is expanded. An expanding ring 14 that comes into contact with the annular portion region 3B of the dicing tape 3 from below is provided.

The expansion regulation ring 16 is formed separately from the frame fixing member 7, and is detachably fixed to the lower surface 7A of the frame fixing member 7. The attachment / detachment structure of the expansion regulation ring 16 with respect to the lower surface 7A is not particularly limited, but as an example, a fastening structure using bolts or a clamp structure using a clamping mechanism may be used.

The frame fixing member 7 is arranged on the same side as the sticking surface of the wafer 1 on the dicing tape 3, and the frame 4 is fixed to the lower surface 7A of the dicing tape 3 via the expansion restriction ring 16. As a result, the expansion regulation ring 16 is held between the frame 4 and the frame fixing member 7.

Further, the frame fixing member 7 is installed at a position separated 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 come into contact with the annular portion region 3B expanded by the expanding ring 14. Has been done. As shown in FIG. 2, the shape of the frame fixing member 7 is, for example, a ring shape having an opening 7B having a diameter of 361 mm, but the shape is not particularly limited, and the expansion regulation ring 16 is detachably fixed. Any shape is acceptable. As the frame fixing member 7, for example, a rectangular plate-shaped material having an opening 7B can be exemplified, and a frame fixing member composed of a plurality of fixing members arranged at predetermined intervals along the outer circumference of the frame 4 can be exemplified. Can also be exemplified. The inscribed circle of these fixing members is set equal to the diameter of the opening 7B.

The expanding ring 14 is arranged on the back surface side of the dicing tape 3 opposite to the sticking surface of the wafer 1, and is smaller than the inner diameter (350 mm) of the frame 4 and larger than the outer diameter (300 mm) of the wafer 1 for expansion. It is formed in a ring shape having an opening 14A. The expanding ring 14 pushes up the back surface of the annular portion region 3B of the dicing tape 3 toward the sticking surface side to expand the annular portion region 3B. That is, the expanding ring 14 is pushed up and moved in the B direction orthogonal to the in-plane direction indicated by the arrow A of the dicing tape 3 with respect to the annular portion region 3B. As a result, the annular region 3B is pushed up by the expanding ring 14 and expanded radially. The expanding ring 14 may be fixed and the wafer unit 2 may be moved downward in the direction of arrow C to expand the annular portion region 3B by the expanding ring 14. The annular region 3B comes into contact with the expansion restricting ring 16 during expansion by the expanding ring 14.

The expansion regulation ring 16 is arranged on the same side as the sticking surface of the wafer 1 in the dicing tape 3, and is smaller than the inner diameter (350 mm) of the frame 4 and larger than the outer diameter of the expanding ring 14. It is formed in a ring shape having.

In the embodiment, the embodiment in which the expansion regulation ring 16 is detachably provided on the lower surface 7A of the frame fixing member 7 and held between the frame 4 and the frame fixing member 7 has been described, but the present invention is not limited thereto. .. For example, as in the expansion regulation ring 17A of the first modification shown in FIG. 3A, the frame fixing member 7 may be detachably fixed to the upper surface 7C. Further, as in the expansion regulation ring 17B of the second modification shown in FIG. 3B, the frame fixing member 7 may be detachably fixed to the inner peripheral portion of the opening 7B. Further, it may be detachably fixed to another component (not shown) of the work dividing device 10 at a position separated from the frame fixing member 7.

FIG. 4 is a vertical cross-sectional view of the wafer unit 2 showing the shape of the annular portion region 3B being expanded by the expanding ring 14.

As shown in FIG. 4, when the annular portion region 3B is expanded by the expanding ring 14, the annular portion region 3B is brought into contact with the expansion restriction ring 16. Specifically, the annular portion region 3B is brought into contact with the inner edge portion 16B of the opening 16A.

In the embodiment, as shown in FIG. 1, the diameter of the opening 16A is set to 338 mm. As a result, the width dimension of the outer peripheral side region 3E whose expansion is restricted by the expansion regulation ring 16 is set to 6 mm, and the width dimension of the inner peripheral side region 3F excluding the outer peripheral side region 3E of the annular portion region 3B is set to 19 mm. Will be done.

Here, of the annular portion region 3B, the inner peripheral side region 3F whose expansion is not regulated by the expansion regulation ring 16 is a region that substantially contributes to the division of the wafer 1. That is, as the width dimension of the inner peripheral side region 3F is reduced, the spring constant of the inner peripheral side region 3F increases, so that the tension applied to the wafer 1 from the inner peripheral side region 3F can be increased. Therefore, it is preferable to set the width dimension of the inner peripheral side region 3F according to the number of planned division lines 5.

Hereinafter, an example of the work dividing method by the work dividing device 10 will be described with reference to the flowchart of FIG. This work dividing method includes a fixing step, an arranging step, and an extended dividing step. Further, the expansion division process includes an expansion start process, an expansion regulation process, and a division process.

First, in step S100 of FIG. 5, as shown in FIG. 1, the frame 4 of the wafer unit 2 is fixed to the frame fixing member 7 via the expansion regulation ring 16 (fixing step, arranging step). At this time, when the expansion regulation ring 16 is arranged apart from the frame fixing member 7, the arrangement step of the expansion regulation ring 16 and the fixing step by the frame fixing member 7 are performed independently.

Next, in step S110 of FIG. 5, the expanding ring 14 is pushed up and moved in the direction of arrow B from the position of FIG. 1 to start expansion of the entire region of the annular portion region 3B (expansion start step).

Next, in step S120 of FIG. 5, when the amount of push-up movement of the expanding ring 14 exceeds the thickness of the frame 4, the annular portion region 3B comes into contact with the expansion restricting ring 16. At this time, as shown in FIG. 4, the annular portion region 3B is located on the outer peripheral side region 3E located on the outer peripheral side and the inner peripheral side with the contact portion 3D in contact with the inner edge portion 16B of the expansion regulation ring 16 as a boundary. It is divided into the inner peripheral side area 3F. Then, of the annular portion region 3B, the expansion of the outer peripheral side region 3E is regulated by the expansion regulation ring 16 (expansion regulation step).

Next, in step S130 of FIG. 5, the push-up movement of the expanding ring 14 is continued, and the inner peripheral side region 3F excluding the outer peripheral side region 3E is restricted while restricting the expansion of the outer peripheral side region 3E in the annular portion region 3B. By continuing the expansion, the wafer 1 is divided into individual chips 6 (division step). After this, the push-up movement of the expanding ring 14 is stopped.

In the expansion operation by the expanding ring 14 after the annular portion region 3B abuts on the inner edge portion 16B of the expansion regulation ring 16 in the division step (S130), the expansion of the outer peripheral side region 3E is regulated by the expansion regulation ring 16 and is inside. Only the peripheral area 3F is expanded. That is, the tension of the spring constant of the inner peripheral side region 3F, which is larger than the spring constant of the annular portion region 3B, is applied to the wafer 1.

Specifically, since the length of the annular portion region 3B that contributes to the division of the wafer 1 is shortened from 25 mm (width dimension of the annular portion region 3B) to 19 mm (width dimension of the inner peripheral side region 3F), the spring constant Increases in inverse proportion to it. As a result, even if only the inner peripheral side region 3F is expanded, the spring constant of the inner peripheral side region 3F is larger than the spring constant of the annular portion region 3B. A tension sufficient to divide the chip 6 can be applied to the wafer 1. Therefore, according to the work dividing device 10, it is possible to solve the undivided problem of the scheduled division line that occurs when the chip size is a small chip (1 mm).

The inner edge portion 16B of the expansion regulation ring 16 that is in line contact with the adhesive layer of the annular portion region 3B is subjected to surface processing such that the arithmetic mean roughness (Ra) is 1.6 (μm) as an example. .. As a result, it is possible to prevent the inner edge portion 16B and the annular portion region 3B from slipping relatively due to the frictional force between the inner edge portion 16B and the annular portion region 3B. Further, the inner edge portion 16B is chamfered with C0.2 as an example. As a result, when an expanding force is received from the annular portion region 3B, it is possible to prevent the annular portion region 3B from being broken by the reaction force.

On the other hand, in the work dividing device 10, since the expansion regulation ring 16 is detachable from the frame fixing member 7, the following work dividing method can be particularly adopted.

FIG. 6 is a flowchart showing another example of the work dividing method.

In the work dividing method shown in FIG. 6, it is determined whether or not to use the expansion regulation ring 16 based on the number of scheduled division lines 5 formed on the wafer 1 to be divided, and the wafer 1 is divided into individual chips 6. It is a method of dividing.

First, in step S200 of FIG. 6, when the number of scheduled division lines 5 formed on the wafer 1 is larger than the specified number, that is, the tension due to the expansion of the annular portion region 3B or more when dividing the wafer 1 or more. When force is required, the extension regulation ring 16 is attached to the frame fixing member 7 as described above. Then, the wafer 1 is divided into individual chips 6 by going through the fixing step of step S100, the expansion step of step S110, the expansion regulation step of step S120, and the division step of step S130 shown in FIG. As a result, the problem of undivided lines to be divided can be solved.

On the other hand, in step S200 of FIG. 6, when the number of scheduled division lines 5 formed on the wafer 1 is less than the specified number, that is, when the wafer 1 can be divided by the tension due to the expansion of the annular portion region 3B. Removes the expansion regulation ring 16 from the frame fixing member 7 in step S210 (extension regulation ring removal step).

Next, in step S220, the frame 4 is fixed by the frame fixing member 7 (fixing step).

Next, in step S230, the annular portion region 3B is expanded by the expanding ring 14, and the wafer 1 is divided into individual chips 6 by the tension of the annular portion region 3B (expansion division step).

When the number of planned division lines 5 is less than the specified number and the wafer 1 that can be divided without using the expansion regulation ring 16 is to be divided by using the expansion regulation ring 16, the increased tension of the inner peripheral side region 3F causes the wafer 1 to be divided. In addition to the planned division line 5, the chip 6 itself may be damaged. Specifically, in the wafer 1 having a diameter of 300 mm, the wafer 1 to be divided into chips 6 having 60 planned division lines and a chip size of 10 mm may damage the chips 6 themselves. Therefore, in the case of the wafer 1 in which the number of planned division lines 5 is less than the specified number and the wafer 1 can be divided without using the expansion regulation ring 16, the expansion regulation ring 16 is removed from the frame fixing member 7 and the wafer 1 is individually chipped. It is preferable to divide it into six parts.

The specified number of planned division lines 5 is the number of wafers 1 that require a force greater than the tension due to the expansion of the annular portion region 3B when the wafer 1 is divided into individual chips 6. As an example, in the case of the wafer 1 having a diameter of 300 mm shown in FIG. 13, the specified number is set to 600.

Further, in the work dividing device 10, a plurality of expansion regulation rings 16 having different diameters of the openings 16A are arranged, and one expansion regulation ring 16 selected from the expansion regulation rings 16 is used. As a result, the diameter of the opening 16A can be changed, and the width dimension of the inner peripheral side region 3F can be changed, so that the tension applied to the wafer 1 from the inner peripheral side region 3F can be changed. Since there are a plurality of wafers 1 having different numbers of planned division lines 5, a plurality of expansion regulation rings 16 having different diameters of the openings 16A corresponding to the number of planned division lines 5 of those wafers 1 are provided. Align them. As a result, one expansion regulation ring 16 corresponding to the number of planned division lines 5 of the wafer 1 can be selected and used from the plurality of expansion regulation rings 16. As the diameter of the opening 16A, in addition to 338 mm, for example, 346 mm, 342 mm, and 334 mm can be exemplified.

It is preferable that these extended regulation rings 16 are stored in advance in a ring storage unit (not shown) provided in the work dividing device 10. One of the plurality of expansion regulation rings 16 stored in the ring storage portion may be manually taken out from the ring storage portion and fixed to the frame fixing member 7, or the expansion regulation ring 16 may be fixed to the frame fixing member 7 from the ring storage portion. It may be carried out by the transport device and transported to the split stage of the work split device 10. Further, the work of carrying out the expansion regulation ring 16 from the ring storage portion, the work of transporting the expansion regulation ring 16 to the division stage, and the work of fixing the expansion regulation ring 16 to the frame fixing member 7 at the division stage may be automated. ..

Further, since the expansion regulation ring 16 can be attached to and detached from the frame fixing member 7, the expansion regulation ring 16 can be retrofitted to an existing (shipped) work dividing device that does not have the expansion regulation ring 16. Further, the expansion regulation ring 16 corresponding to the number of planned division lines 5 of the wafer 1 can be retrofitted to the existing work division apparatus. This makes it possible to process large chips to small chips using an existing work dividing device. Further, when the chip size is large, that is, when the number of scheduled division lines 5 is less than the specified number, the expansion regulation ring 16 can be removed from the existing work division device.

By the way, in the expansion division step of S110 to S130 shown in FIG. 5, in order to divide the wafer 1 into individual chips 6, the relative position (push amount) and relative speed (push speed) between the frame 4 and the expanding ring 14 are used. The division process is performed by setting the extended division conditions such as.

In the case of the dicing device 10 that selectively uses one of the plurality of expansion regulation rings 16 having different diameters of the openings 16A, the following division processing is performed by setting the push-up amount and the push-up speed to be constant. A problem occurs. Therefore, it is necessary to set the extended division condition for each extended regulation ring 16.

When the push-up amount is set to be constant, the expansion rate after the expansion of the dicing tape 3 is completed differs depending on the selected expansion regulation ring 16.

Here, the expansion rate of the dicing tape 3 is defined below.

[Expansion rate E (%)]
The expansion rate E represents the elongation rate of the tape diameter in the expanding step in a state where only the dicing tape 3 is attached to the frame 4. Further, the elongation of the dicing tape 3 is considered to be uniform unless the expansion is regulated. For example, if the distance of 350 mm is extended to 380 mm, the expansion rate E is
{(380/350) -1} x 100 = 8.6%.

In FIGS. 1 and 4, the expansion rate E is defined as follows. Hereinafter, 3A refers to the central region 3A, and 3B refers to the annular region 3B.

(i) The expansion rate E before the dicing tape 3 comes into contact with the expansion regulation ring 16 or when the expansion regulation ring 16 is absent.

Expansion rate E = {(3B + 3A + 3B after expansion) / (3B + 3A + 3B before expansion) -1} × 100
In the case of the frame 4 of the present embodiment, 3B + 3A + 3B before expansion is 350 mm. In this formula, the expansion rate when the dicing tape 3 comes into contact with the expansion regulation ring 16 is defined as Ec.

(ii) Expansion rate E when the dicing tape 3 comes into contact with the expansion regulation ring 16.

Expansion rate E = [(1 + Ec / 100) × {(3F + 3A + 3F after expansion) / (3F + 3A + 3F at the time of contact with the regulation ring)} -1] × 100
This is because the region to be expanded changes from 3B + 3A + 3B to 3F + 3A + 3F when it comes into contact with the expansion regulation ring 16.

The graph of FIG. 7 shows that when the push-up amount of the expanding ring 14 is set to be constant, the expansion rate of the dicing tape 3 differs depending on the expansion restriction ring 16 selected.

In the graph of FIG. 7, the vertical axis shows the expansion rate (%), the horizontal axis shows the push-up amount (mm), and the change of the expansion rate (%) with respect to the push-up amount (mm) is shown by lines A, B, and C. Has been done. The line A shows the change in the expansion rate (%) of the dicing tape 3 when the expansion regulation ring 16 is not used (the diameter of the opening 16A corresponds to 350 mm), and the line B shows the change in the diameter of the opening 16A of 342 mm. The change in the expansion rate (%) of the dicing tape 3 when the expansion regulation ring 16 is used is shown, and the line C shows the expansion rate of the dicing tape 3 when the expansion regulation ring 16 having a diameter of the opening 16A of 338 mm is used. It shows a change in (%).

FIG. 8 is a schematic view showing the operation during the expansion division step, and FIG. 8 shows the dimensions of each member for calculating the expansion ratio (%) of the lines A, B, and C. According to FIG. 8, it is shown that the inner diameter D1 of the frame 4 is 350 mm, the thickness t of the frame 4 is 1.5 mm, and the diameter D2 of the opening 16A of the expansion regulation ring 16 is 342 mm or 338 mm. Further, x in FIG. 8 indicates the amount of push-up (mm) of the expanding ring 14. Further, a roller 32 for reducing the frictional force with the dicing tape 3 is arranged at the upper end of the expanding ring 14, and it is shown that the arrangement diameter D3 of the roller 32 is 323.2 mm. In calculating the expansion rate (%), formulas such as ordinary trigonometric functions were used. The expansion rate (%) of the line A was calculated assuming that the diameter d of the roller 32 was 5 mm, and the expansion rate (%) of the lines B and C was calculated assuming that the diameter d of the roller 32 was 7 mm.

First, a target expansion rate after expansion is set for smoothly dividing the wafer 1 into individual chips 6. In this embodiment, the target expansion rate is set to 6.6%. This target expansion rate is an example and is not limited to 6.6%.

As shown in FIG. 7, when the target expansion rate is set to 6.6%, a push-up amount x of 20.0 mm is required in the form in which the expansion regulation ring 16 shown by the line A is not used. On the other hand, in the form in which the expansion regulation ring 16 shown by the line B is used, when the expanding ring 14 is pushed up by 20 mm, the expansion rate at that time is 7.3%. Further, in the form in which the expansion regulation ring 16 shown by the line C is used, when the expanding ring 14 is pushed up by 20 mm, the expansion rate at that time becomes 8.2%. That is, when the expansion regulation ring 16 is used, the expansion rate becomes larger and exceeds the target expansion rate as compared with the case where the expansion regulation ring 16 is not used. As a result, there may be a problem that the divided chips 6 are peeled off from the dicing tape 3 due to the excessive expansion of the dicing tape 3. Therefore, it is necessary to change the push-up amount x according to the diameter of the opening 16A.

Therefore, in the work dividing method of the present embodiment, the push-up amount x of the expanding ring 14 is not set to be constant regardless of the diameter of the opening 16A, but the push-up amount for each expansion regulation ring 16 having a different diameter of the opening 16A. Set x. Specifically, in the form of using the expansion regulation ring 16 shown by the line B, the push-up amount x is set to 18.7 mm, and the expansion rate after the end of expansion is made equal to the target expansion rate (6.6%). Similarly, in the form in which the expansion regulation ring 16 shown by the line C is used, the push-up amount x is set to 17.3 mm, and the expansion rate after the end of expansion is made equal to the target expansion rate (6.6%).

As described above, in the work division method of the present embodiment, each expansion regulation ring 16 having a different diameter of the opening 16A is based on the target expansion ratio after the expansion for smoothly dividing the wafer 1 into individual chips 6. Set the push-up amount x to. That is, the push-up amount x is set smaller as the diameter of the opening 16A of the expansion regulation ring 16 becomes smaller. As a result, according to the work dividing method of the present embodiment, all the chips 6 can be smoothly divided even if the expansion restricting rings 16 having different diameters of the openings 16A are used. Therefore, the problem that the divided chips 6 are peeled off from the dicing tape 3 can be solved.

On the other hand, when the push-up speed of the expanding ring 14 is constant, the expansion rate speed of the dicing tape 3 becomes the maximum (maximum expansion rate speed) immediately before the push-up speed starts deceleration. Here, the expansion rate speed of the dicing tape 3 is defined below.

[Expansion rate rate (% / sec)]
Expansion rate speed = rate of increase of expansion rate per unit time In the graph of FIG. 9, the left vertical axis indicates the expansion rate rate (% / sec), the right vertical axis indicates the push-up speed (mm / sec), and the horizontal axis. Indicates the amount of push-up x (mm), and the change in the rate of expansion (% / sec) with respect to the push-up speed (mm / sec) of the expanding ring 14 is shown. That is, the line D in FIG. 9 shows the push-up speed (% / sec) of the expanding ring 14, and the line E shows the expansion rate speed (% / sec).

As shown in FIG. 9, when the push-up speed (200 mm / sec) is constant, the maximum expansion rate speed increases according to the push-up amount x. Then, when the maximum expansion rate speed (113 (% / sec)) indicated by the point F is reached, the push-up speed starts decelerating, so that the expansion rate speed decreases. Therefore, when the push-up speed is constant, the maximum expansion rate speed is reached for a moment at point F, and when the maximum expansion rate speed is reached, the tension of the dicing tape 3 becomes maximum. In the expansion division step, it is desirable to perform the division process in a state where the maximum expansion rate rate is maintained for a certain period of time, that is, in a state where the maximum tension of the dicing tape 3 is maintained for a certain period of time. In that case, the maximum expansion rate speed can be obtained only for a moment at the F point. As a result, the maximum tension of the dicing tape 3 cannot be effectively transmitted to the wafer 1, and a part of the planned division line may not be divided.

Therefore, in the work division method of the present embodiment, as shown in the graph of FIG. 10, the push-up speed is set so that the maximum expansion rate speed (113 (% / sec)) is maintained for a certain period of time in the expansion division step.

In the graph of FIG. 10, similarly to the graph of FIG. 9, the left vertical axis shows the expansion rate speed (% / sec), the right vertical axis shows the push-up speed (mm / sec), and the horizontal axis shows the push-up amount (mm). ) Is shown, and the change in the expansion rate rate (% / sec) with respect to the push-up speed (mm / sec) of the expanding ring 14 is shown. That is, the line G in FIG. 10 shows the push-up speed (mm / sec) of the expanding ring 14, and the line H shows the expansion rate speed (% / sec).

As shown by line G in FIG. 10, the push-up speed of the expanding ring 14 is set to a constant speed (400 mm / sec) from the start of push-up to the push-up amount of 5.0 mm. Then, in the section from the push-up amount of 5.0 mm to the push-up amount of 18.0 mm, the push-up speed is reduced from 400 mm / sec to 200 mm / sec in a quadratic curve.

As a result, in the work dividing method of the present embodiment, as shown by the line H in FIG. 10, the maximum expansion rate velocity (113 (% / sec)) is stabilized in the section from the push-up amount of 6.0 mm to 18.0 mm. Can be obtained. Therefore, according to the work dividing method of the present embodiment, the maximum tension of the dicing tape 3 can be effectively transmitted to the wafer 1, so that the problem that a part of the planned division line is not divided can be solved. ..

The graph of FIG. 10 shows an example of the push-up speed when the push-up amount x is set to 20.0 mm, but when the push-up amount x is set to 18.7 mm (the diameter of the opening 16A is 342 mm). The maximum expansion rate speed is expanded even when the expansion regulation ring 16 of the above is used) or when the push-up amount x is set to 17.3 mm (when the expansion regulation ring 16 having an opening 16A having a diameter of 338 mm is used). It is preferable to set the push-up speed so that it is maintained for a certain period of time in the dividing step.

That is, according to the work division method of the present embodiment, the push-up speed is set so that the maximum expansion rate speed for each expansion regulation ring 16 having a different diameter of the opening 16A is maintained for a certain period of time in the expansion division step. Is preferable.

FIG. 11 is a flowchart of the work dividing method including the extended division condition setting step (S105) in the process of the work dividing method shown in FIG.

As shown in FIG. 11, the work division method of the present embodiment includes an expansion division condition setting process (S105) between the fixing process / arrangement process (S100) and the expansion start process (S110). In this expansion division condition setting step (S105), the push-up amount x is set based on the expansion rate after the expansion corresponding to each of the plurality of expansion regulation rings 16 having different diameters of the opening 16A, so that the diameter of the opening 16A is set. Even if the extended regulation ring 16 is used, all the chips 6 can be smoothly divided. As a result, the problem that the divided chips 6 are peeled off from the dicing tape 3 can be solved.

Further, in the expansion division condition setting step (S105), the push-up speed is set so that the maximum expansion rate speed is maintained for a certain period of time in the expansion division process, so that the problem that a part of the planned division line is not divided is solved. can do.

It should be noted that the work dividing method of the present embodiment can also solve the problem of undivided planned division lines that occurs when the chip size is small.

1 ... Wafer, 2 ... Wafer unit, 3 ... Dicing tape, 3A ... Central region, 3B ... Circular region, 3C ... Fixed region, 3D ... Contact, 3E ... Outer peripheral region, 3F ... Inner peripheral region , 3FA ... Inner circumference side area, 3FB ... Inner circumference side area, 4 ... Frame, 5 ... Scheduled division line, 6 ... Chip, 7 ... Frame fixing member, 8 ... Expanding ring, 10 ... Work dividing device, 14 ... Expanding ring , 14A ... opening, 16 ... expansion regulation ring, 16A ... opening, 16B ... inner edge, 17A, 17B, 17C ... expansion regulation ring, 20 ... expansion regulation ring, 20A ... opening, 22 ... wafer, 24 ... chip , 26 ... Extended regulation ring, 26A ... Opening, 28 ... Wafer, 30 ... Chip, 32 ... Roller

Claims (3)

In the work dividing method in which the work attached to the dicing tape is divided into individual chips by pushing up the dicing tape by expanding and expanding the dicing tape.
An extended division condition setting step for setting an extended division condition for the expanding ring with respect to the dicing tape, and an extended division condition setting step.
When the dicing tape is expanded, the dicing tape is brought into contact with the inner edge of the opening of the expansion regulation ring to divide the work into individual chips.
When the rate of increase of the expansion rate of the dicing tape per unit time is defined as the expansion rate rate, the expansion division condition setting step is performed in the expansion division so that the maximum expansion rate rate is maintained for a certain period of time in the expansion division step. A work dividing method in which the pushing-up speed of the expanding ring is set as a condition. In the expansion division condition setting step, the push-up amount of the expanding ring is set as the expansion division condition, and the push-up amount is set smaller as the diameter of the opening of the expansion regulation ring is smaller. The work dividing method according to claim 1. The claim that the expansion division condition setting step sets the push-up amount so that the target expansion ratio of the dicing tape after the expansion is equal even when the expansion regulation ring having a different diameter of the opening is used. The work dividing method according to 2.

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