JP2019121759A - Work division apparatus and work division method - Google Patents

Abstract

To provide a work division apparatus and a work division method that can solve a problem of an undivided planned division line which occurs when the chip size is a small chip.SOLUTION: A work division method includes an expansion restriction step of bringing an expansion restriction ring 16 into contact with an annular portion area 3B of a dicing tape, and restrict the expansion of the outer peripheral area located on the outer peripheral side of the annular portion area 3B at the boundary of the abutting portion abutted by the expansion restriction ring 16, an expansion step of pressing and expanding the inner peripheral area of the annular portion region 3B by an expand ring 14, an expansion restricting ring retracting step of retracting and moving the expansion restricting ring 16 from the restricting position to restrict the expansion of the outer peripheral area to the retracting position.SELECTED DRAWING: Figure 8

Description

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

  Conventionally, in manufacturing a semiconductor chip (hereinafter referred to as a chip), a semiconductor wafer (hereinafter referred to as a wafer) in which lines to be divided are formed in advance by forming a modified region by half cutting or laser irradiation with a dicing blade. There is known a work dividing apparatus which divides a chip into individual chips along a line to be divided (see Patent Document 1 etc.).

  FIG. 15 is an explanatory view of the wafer unit 2 to which the disk-like wafer 1 divided by the work dividing apparatus is attached, FIG. 15 (A) is a perspective view of the wafer unit 2, and FIG. 15 (B) is a wafer. FIG. 6 is a cross-sectional view of unit 2;

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

  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 shown by a two-dot chain line. Thereafter, an expand ring (also referred to as a push-up ring) 8 indicated by a two-dot chain line is raised from below the wafer unit 2 and the dicing tape 3 is pressed and expanded radially by the expand ring 8. The tension of the dicing tape 3 generated at this time is applied to the dividing lines 5 of the wafer 1 to divide the wafer 1 into individual chips 6. The lines to be divided 5 are formed in the X direction and the Y direction intersecting each other. In the case where the number of lines parallel to the X direction and the number parallel to the Y direction are the same with respect to the planned dividing line 5 and the intervals in the respective directions are equal, the shape of the divided chip 6 is square . Further, in the case where the number parallel to the X direction is different from the number parallel to the Y direction, if the intervals in the respective directions are equal, the shape of the divided chips 6 becomes rectangular.

  The dicing tape 3 is a flexible member having a low Young's modulus. Therefore, in order to smoothly divide the wafer 1 into the 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 expansion device (work dividing device) of Patent Document 2 includes cold air supply means. According to Patent Document 2, the dicing tape is cooled by operating 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 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, and in order to expand the dicing tape uniformly in consideration of the anisotropy, a film It has a surface support mechanism. This film surface support mechanism comprises a plurality of circumferentially independent support mechanisms, and by individually controlling the relative heights of the plurality of support mechanisms to adjust the tension of the dicing tape, the X of the dicing tape can be obtained. The elongation in the direction and the elongation in the Y direction are controlled independently.

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

  The force required to divide the wafer 1, that is, the tension that must be generated in the annular region 3B to divide the wafer 1, must be increased as the number of planned division lines 5 increases. Are known. About the number of planned dividing lines 5, for example, in the case of a wafer 1 with a diameter of 300 mm and a chip size of 5 mm, approximately 120 (60 each in the X and Y directions) of planned dividing lines 5 are formed and the chip size is 1 mm Of about 600 divided lines 5 are formed. Therefore, the tension that must be generated in the annular region 3B must be increased as the tip size decreases.

JP, 2016-149581, A JP, 2016-12585, A Patent No. 5912274 gazette

  By the way, the inner diameter (diameter of the inner edge of the frame) of the frame 4 on which the wafer 1 with a diameter of 300 mm is mounted is set to 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 longitudinal sectional view of wafer unit 2 of FIG. 16, an annular portion region 3B having a width of 25 mm is present between the outer edge portion of wafer 1 and the inner edge portion of frame 4. . Further, as in the longitudinal sectional view of the main part of the work dividing apparatus shown in FIGS. 17A and 17B, the frame fixing member 7 for fixing the frame 4 does not contact the annular portion region 3B expanded by the expand ring 8 Thus, they are installed at positions spaced outward from the annular portion region 3B in the in-plane direction of the dicing tape 3 indicated by the arrow A.

  Therefore, the force to divide the wafer 1 generated by the upward movement of the expand ring 8 is (i) force to expand the entire area of the annular portion region 3B, (ii) force to divide the wafer 1 into chips 6, (iii) It is decomposed into three forces of expanding the dicing tape 3 between the adjacent chips 6 and 6.

  As shown in the operation diagrams of the work dividing apparatus shown in FIGS. 18A to 18E, the expand ring 8 abuts on the annular portion area 3B of the dicing tape 3 and the expansion operation of the expanding ring 8 starts the expansion of the dicing tape 3 And (FIG. 18 (A)), first, the expansion of the annular portion region 3B having the lowest spring constant starts (FIG. 18 (B)). As a result, tension is generated in the annular region 3B, and when the tension is increased to some extent, the increased tension is transmitted to the wafer 1 to start dividing the wafer 1 into the chips 6 (FIG. 18C). When the wafer 1 is divided into the individual chips 6, the expansion of the annular region 3B and the expansion of the dicing tape 3 between the chips proceed simultaneously (FIGS. 18D to 18E).

  In the conventional work dividing apparatus, when the chip size is 5 mm or more in the wafer 1 having a diameter of 300 mm, it was possible to divide into individual chips 6 without problems by the tension generated in the annular portion region 3B. However, with the miniaturization of the circuit pattern formed on the wafer 1, chips smaller than 1 mm in chip size have also appeared. In this case, the force required to divide the wafer 1 is increased due to the increase in the number of dividing lines 5 dividing the wafer 1 and a force more 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 wafer unit 2 in FIG. 19, even if the expanding operation by expanding ring 8 is completed, a part of planned dividing line 5 formed on wafer 1 is not divided and remains undivided. Had a problem.

  Such an undivided problem of the planned dividing line 5 can not be solved even if the expansion amount or expansion speed of the dicing tape 3 is increased. 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, 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 It does not occur. On the other hand, even when the expansion speed of the dicing tape 3 is increased, since a part of the annular portion region 3B starts plastic deformation, no tension is generated to divide the wafer 1 into the individual chips 6. 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 time lag.

  In Patent Document 2, the dicing tape is cooled and the spring constant of the dicing tape is increased to solve the problem of undivision of the planned division line 5, but for small chips of 1 mm or less in recent years Can not get enough effect.

  Further, the chip separation and separation apparatus of Patent Document 3 can independently control the elongation in the X direction and the elongation in the Y direction of the dicing tape but applies a force over the tension by the expansion of the annular portion region to the wafer. Since it is impossible, it is impossible to solve the problem of undivision of the planned division line.

  The present invention has been made in view of such problems, and provides a work dividing apparatus and a work dividing method capable of solving the undividing problem of the planned dividing line which occurs when the chip size is a small chip. With the goal.

  In order to achieve the object of the present invention, in the work dividing apparatus according to the present invention, the outer periphery 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 In a work dividing device for dividing into individual chips along a planned dividing line, an opening which is disposed on the back side opposite to the work adhering surface of the dicing tape and which is 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 being moved in a direction relatively approaching to the dicing tape, an annular portion between the outer edge portion of the work and the inner edge portion of the frame in the dicing tape An expansion ring that presses and expands the area, and is placed on the same side as the work surface on the dicing tape An expansion regulating ring formed in a ring shape having an opening smaller than the inner diameter of the frame and larger than the outer diameter of the expanding ring, the abutment portion being in contact with the expansion regulating ring in the annular portion region Between the extended restricting ring that restricts the expansion of the outer peripheral area located on the outer peripheral side with the boundary, the restricted position that restricts the expansion of the outer restricted area, and the retracted position retracted from the restricted position And an expansion restriction ring movement mechanism capable of adjusting the restriction position.

  In one aspect of the present invention, the restricting position is preferably a first restricting position on the same surface as the tape application surface to which the dicing tape of the frame is attached.

  In one aspect of the present invention, the restricting position is preferably a second restricting position on the side where the expanding ring is disposed rather than the tape sticking surface to which the dicing tape of the frame is stuck.

  One embodiment of the present invention is an expanded retaining ring formed in a ring shape having an elastically deformable fitting portion that is disposed on the back side opposite to the work sticking surface of the dicing tape and that is larger than the inner diameter of the frame. And an expansion holding ring for holding the expanded state of the dicing tape by fitting the fitting portion to the surface of the frame after moving the expansion restriction ring from the restriction position to the retracted position by the expansion restriction ring moving mechanism; It is preferable to have.

  In order to achieve the object of the present invention, in the work dividing method according to the present invention, the outer periphery 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 In the work dividing method in which the chip is divided into individual chips along the planned dividing line, the expand ring disposed on the back side opposite to the sticking surface of the work in the dicing tape is moved in a direction relatively approaching the dicing tape By expanding the annular area of the dicing tape between the outer edge of the workpiece and the inner edge of the frame by an expanding ring, and an expansion process when expanding the workpiece, the dicing tape The expansion restriction ring and the annular part area arranged on the same side as the pasting surface are abutted at the restriction position. Te, and a expansion restricting step of restricting the expansion of the outer peripheral side region located on the outer peripheral side abutment is in contact with the extended restriction ring as a boundary.

  In one aspect of the present invention, the restricting position is preferably a first restricting position on the same surface as the tape application surface to which the dicing tape of the frame is attached.

  In one aspect of the present invention, the restricting position is preferably a second restricting position on the side where the expanding ring is disposed rather than the tape sticking surface to which the dicing tape of the frame is stuck.

  According to an aspect of the present invention, the outer periphery of the extended holding ring is moved by moving the extended holding ring disposed on the back surface side opposite to the work sticking surface of the dicing tape relatively toward the dicing tape. Preferably, an elastically deformable fitting portion formed in the portion is fitted on the surface of the frame to hold an expanded state of the dicing tape.

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

Principal part structural drawing of the work dividing apparatus according to the first embodiment Principal part enlarged perspective view of the work dividing apparatus shown in FIG. 1 Principal part enlarged cross-sectional view of wafer unit showing the shape of the annular part area in the middle of expansion Longitudinal sectional view showing expansion state of dicing tape by expansion holding ring Principal part enlarged sectional view of FIG. 4 Block diagram showing control system of work dividing device Flow chart showing an example of wafer dividing method Operation explanation of work dividing device Operation explanation of work dividing device Structure diagram explaining another work dividing method by work dividing device Principal part enlarged cross-sectional view of wafer unit showing the shape of the annular part area in the middle of expansion Graph which calculated change of expansion rate to pushing up amount A schematic diagram showing the operation in the expansion process Graph which calculated change of expansion rate speed to push up speed Illustration of the wafer unit with the wafer attached Longitudinal section of wafer unit Side view of main part of work dividing device Operation diagram of work dividing device Longitudinal sectional view of wafer unit in which wafer is divided

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

  FIG. 1 is a longitudinal sectional view of an essential part of a work dividing apparatus 10 according to the embodiment, and FIG. 2 is an enlarged perspective view of an essential part of the work dividing apparatus 10. As shown in FIG. Although the size of the wafer unit divided by the work dividing apparatus 10 is not limited, the embodiment illustrates the wafer unit 2 on which the wafer 1 with a diameter of 300 mm shown in FIG. 15 is mounted.

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

  The wafer 1 is attached to the central portion of the dicing tape 3 as shown in FIGS. In the dicing tape 3, the fixing portion region 3 </ b> C of the dicing tape 3 is attached (fixed) to the tape application surface 4 </ b> A of the frame 4. The dicing tape 3 has a central region 3A of a circular shape in a plan view to which the wafer 1 is attached, and a planar donut shape between the outer edge (the outer edge of the wafer 1) of the central region 3A and the inner edge of the frame 4 And an annular portion region 3B.

  The thickness of the wafer 1 is, for example, about 50 μm. Further, as the dicing tape 3, for example, a tape of PVC (polyvinyl chloride) 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 work dividing apparatus 10 includes a frame fixing member 7 for fixing the frame 4, an expand ring 14 for expanding the dicing tape 3 by pressing the annular part area 3 B of the dicing tape 3 from the lower side to the upper side, An expansion restraining ring 16 is brought into contact with the annular portion region 3B from the upper side, and an expansion holding ring 18 for holding the expanded state of the dicing tape 3 expanded by the expand ring 14.

  The frame fixing member 7 is disposed on the same side as the pasting surface of the wafer 1 in the dicing tape 3, and the surface 4B of the frame 4 is fixed to the lower surface 7A. Further, 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 done.

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

  Expanding ring 14 is disposed on the back side of dicing tape 3 opposite to the surface to which wafer 1 is attached, smaller than the inner diameter of frame 4 (350 mm: see FIG. 16), and the outer diameter of wafer 1 (300 mm: FIG. 16). And the expansion opening (opening) 14A larger than the reference. Expanding ring 14 is disposed movably in a direction approaching relative to dicing tape 3. Specifically, the expand ring 14 presses the back surface of the annular portion region 3B of the dicing tape 3 upward to expand the annular portion region 3B (the position shown by the two-dot chain line in FIG. 1); It is disposed movably in the vertical direction between a retraction position (a position shown by a solid line in FIG. 1) retracted downward from the partial region 3B.

  The work dividing apparatus 10 is provided with an expanding ring moving mechanism 20 for moving the expanding ring 14 up and down between the expansion position and the retraction position. Although a feed screw device is illustrated as an example of the expand ring moving mechanism 20, an actuator such as an air cylinder device may 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 portion region 3B. As a result, the back surface of the annular portion region 3B is pressed by the expand ring 14 and radially expanded.

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

  The expansion restricting ring 16 has a first restricting position (the position shown by a two-dot chain line in FIG. 1) in which the lower edge portion 16A is in contact with the surface of the annular portion region 3B and a retraction retracted upward from the first restricting position. It is disposed so as to be vertically movable between the position (the position shown by the solid line in FIG. 1).

  The first restricting position is a position at which the expansion restricting ring 16 restricts the expansion of the outer peripheral region 3E. In FIG. 1, the lower edge 16A of the expansion restricting ring 16 is the same as the tape sticking surface 4A of the frame 4 The first restricting position is set at a position located on the surface. The outer peripheral region 3E is a region located on the outer peripheral side of the annular portion region 3B with the contact portion 3D being in contact with the lower edge portion 16A of the expansion restricting ring 16 as a boundary. In the annular portion region 3B, the region excluding the outer peripheral region 3E is the inner peripheral region 3F, and the inner peripheral region 3F is a region expanded by the expand ring 14.

  The workpiece dividing device 10 is provided with an expansion regulating ring moving mechanism 22 for moving the expansion regulating ring 16 up and down between the first regulation position and the retracted position. Although an air cylinder apparatus is illustrated as an example of expansion regulation ring moving mechanism 22, actuators, such as a feed screw apparatus, can also be used instead.

  FIG. 3 is an enlarged sectional view of an essential part of the wafer unit 2 showing the shape of the annular portion region 3B in the middle of expansion by the expand ring 14. As shown in FIG.

  As shown in FIG. 3, when expanding the annular portion region 3B by the expand ring 14, the expansion restricting ring 16 is positioned at the first restricting position prior to the expansion operation by the expand ring 14. That is, the expansion of the outer peripheral region 3E of the dicing tape 3 is restricted in advance by the expansion restricting ring 16. Therefore, according to the work dividing apparatus 10 of the embodiment, the expansion of the inner circumferential area 3F is started immediately after the expand ring 14 abuts on the annular portion area 3B.

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

  Here, in the annular portion region 3 </ b> B, the inner circumferential region 3 </ b> F expanded by the expand ring 14 is a region that substantially contributes to the division of the wafer 1. As the width dimension of the inner peripheral region 3F is reduced, the spring constant of the inner peripheral region 3F is increased, so that the tension applied from the inner peripheral region 3F to the wafer 1 is increased. For this reason, the diameter of the expansion regulating opening 16B for determining the width dimension of the inner circumferential side region 3F is set according to the division condition defined by the number of planned division lines 5 or the like.

  On the other hand, the expansion holding ring 18 for holding the expansion state of the dicing tape 3 is disposed on the back side opposite to the pasting surface of the wafer 1 in the dicing tape. Further, the expansion holding ring 18 is mounted on the outer periphery of the main body ring 28 whose outer diameter is smaller than the inner diameter (350 mm) of the frame 4 and whose inner diameter is larger than the outer diameter of the expand ring 14 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 cross-sectional view in which the expansion state of the dicing tape 3 is held by the expansion holding ring 18. FIG. 5 is an enlarged sectional view of a main part of FIG.

  As shown in FIGS. 4 and 5, the fitting portion 30 of the expansion holding ring 18 is fitted to the surface 4B of the frame 4 through the annular portion area 3B of the dicing tape 3 in the fitting position shown by the solid line. Thereby, the expansion state of the dicing tape 3 is held by the expansion holding ring 18.

  Before the expansion holding, the expansion holding ring 18 stands by at the standby position (position shown by the solid line in FIG. 1) below the fitting position shown by the solid line in FIGS. 4 and 5. Is moved upward to the mating position.

  The work dividing device 10 is provided with an expansion holding ring moving mechanism 32 (see FIG. 1) for moving the expansion holding ring 18 up and down between the standby position and the fitting position. Although a feed screw device is illustrated as an example of the expansion holding ring moving mechanism 32, an actuator such as an air cylinder device can be used instead.

  When the expansion holding ring 18 is lifted by the expansion holding ring moving mechanism 32, the fitting portion 30 abuts on the lower surface of the frame 4. Thereafter, the fitting portion 30 is pushed by the inner peripheral surface of the frame 4 and ascends while being elastically deformed, and when it passes through the inner peripheral surface of the frame 4, it fits into the surface 4 B of the frame 4. Thereby, the expanded state of the dicing tape 3 is held.

  Returning to FIG. 1, the expanding ring moving mechanism 20, the expansion regulating ring moving mechanism 22 and the expansion holding ring moving mechanism 32 are controlled by the control unit 34 that centrally controls the work dividing apparatus 10 as shown in the block diagram of the control system of FIG. The operation is controlled. The control unit 34 has a central processing unit (CPU) and a random access memory (RAM), and the RAM includes the expanding ring moving mechanism 20, the expansion regulating ring moving mechanism 22 and the expansion holding ring moving mechanism 32 in a predetermined order. A program for operating at is stored.

  Next, an example of control of each mechanism by the control unit 34 will be described based on an operation explanatory view of the work dividing apparatus 10 shown in the flowchart of FIG. 7 and in FIGS. 8A to 8D and 9A to 9D. Explain.

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

  Next, in the fixing step (S110) of FIG. 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 restriction step (S120) of FIG. 7, as shown in FIG. 8C, the expansion restriction ring 16 is moved from the retracted position to the first restriction position.

  Next, in the expansion start step (S130) of FIG. 7, the expand ring 14 is moved upward from the retracted position of FIG. 8A toward the expanded position as shown in FIG. Expansion is started.

  In this expansion start step (S130), the lower edge 16A of the expansion restricting ring 16 is brought into contact with the surface of the annular portion area 3B in advance to restrict expansion of the outer peripheral area 3E. It is expanded by the expand ring 14. Further, the above-mentioned extension restriction step (S120) is a step performed together with the extension step from the extension start step (S130) to the end of the division step (S140) described later. That is, the expansion process of the present invention refers to the process from the expansion start process (S130) to the end of the division process (S140).

  Next, in the dividing step (S140) of FIG. 7, as shown in FIG. 9A, the expansion of the inner peripheral region 3F is continued by the upward movement of the expanding ring 14, and the wafer 1 is sequentially added to the individual chips 6 in the meantime. I will divide it. 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 expansion process described above is completed.

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

  Specifically, in the expansion step, by using the expansion regulating ring 16 having a diameter of 338 mm for the expansion regulating opening 16B, the length of the area contributing to the division of the wafer 1 is 25 mm (the annular portion area 3B The width dimension is shortened to 19 mm (the width dimension of the inner circumferential region 3F). Therefore, the spring constant of the inner peripheral region 3F is increased, and a 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), a tension sufficient to divide into individual chips 6 is applied to the wafer 1 It can be granted. Therefore, it is possible to solve the undivided problem of the scheduled dividing line which occurs when the chip size is a small chip (1 mm).

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

  Next, in the expansion state holding step (S160) of FIG. 7, the expansion holding ring 18 is lifted from the standby position to the fitting position as shown in FIG. Fit to 4B. Thereby, the expansion holding ring 18 holds the expanded state of the dicing tape 3.

  As described above, in the work dividing method according to the embodiment, after the expansion process is performed, the expansion restriction ring retraction process (S150) is performed, and after the expansion restriction ring retraction process (S150) is performed, the expansion state holding process ( S160) is performed.

  Next, in the expanding ring retraction step (S170) of FIG. 7, as shown in FIG. 9D, the expanding ring 14 is moved downward to return to the retraction position. At this time, the dicing tape 3 is held in the expanded state without slack by the expansion holding ring 18. As a result, the contact between the chips 6 caused by the slackening of the expanded dicing tape 3 can be prevented, so that the quality deterioration 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 undividing problem of the planned dividing line which occurs when the chip size is a small chip, and the problem of the quality deterioration of the chip due to the contact between the divided chips. It can also be erased.

  Further, according to the work dividing method of the embodiment, the expansion restricting ring 16 restricts the expansion of the outer peripheral region 3E in the expansion step. For this reason, the dicing tape 3 in the outer peripheral region 3E is not stretched, and its thickness is maintained at the original thickness. Thus, even when the expansion holding ring 18 is attached to the frame 4 in the expanded state holding step (S160) in a state in which the outer peripheral area 3E is extended, it is possible to prevent the outer peripheral area 3E from being torn.

  Further, in a step subsequent to the dividing step (S140), a heat contraction step may be performed in which the slackened inner peripheral region 3F after expansion is thermally shrunk by light heating and tensioned again. By performing such a thermal contraction step, the inner peripheral region 3F can be tensioned again, so that processing of the wafer unit 2 in the step after the dividing step (S140) is facilitated.

  Moreover, in the pre-process of the expansion start process (S130) of FIG. 7, it is preferable to cool the inner peripheral side area | region 3F to low temperature previously by the cooling means not shown. Thus, the spring constant of the inner peripheral region 3F can be increased prior to the expansion start step (S130). The cooling means may be, for example, a contact type that cools in contact with the inner circumferential area 3F, or an air-cooled type that cools by injecting cold air to the inner circumferential area 3F.

  In addition, it is preferable that the lower edge portion 16A of the expansion regulating ring 16 be subjected to surface processing with an arithmetic average 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 relative slip between the lower edge portion 16A and the annular portion region 3B. it can.

  Further, it is preferable that a chamfering process of C0.2 is applied to the edge of the lower edge portion 16A of the expansion restricting ring 16 as an example. Thereby, it is possible to prevent the annular portion region 3B from being broken 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 structure diagram of the work dividing apparatus 10 for explaining another work dividing method. Further, FIG. 11 shows an enlarged cross-sectional view of the main part of the wafer unit 2 showing the shape of the annular portion region 3B in the middle of expansion by another work dividing method.

  The difference between the workpiece dividing method shown in FIGS. 10 and 11 with respect to the workpiece dividing method shown in FIGS. 8 and 9 is that the expansion ring 14 is disposed at the restriction position of the expansion restriction ring 16 rather than the first restriction position. It is in the point changed to the 2nd control position of the Such adjustment of the restriction position is performed by the expansion restriction ring moving mechanism 22 shown in FIG.

  According to the work dividing method shown in FIGS. 10 and 11, since the surface of the annular region 3B is pressed in advance by the lower edge portion 16A of the expansion regulating ring 16 prior to the expansion operation of the expand ring 14, the inner periphery The side area 3F is expanded in advance by the expansion restriction ring 16.

  Thus, the expansion amount (tension) of the inner peripheral area 3F when the push up amount of the annular portion area 3B is made the same by expanding the inner peripheral area 3F in advance is shown in FIG. 8 and FIG. It can be increased more than the work dividing method. In other words, according to the workpiece dividing method shown in FIGS. 10 and 11, the expansion amount equivalent to the workpiece dividing method in FIGS. 8 and 9 (with a smaller pushing amount than the workpiece dividing method in FIGS. 8 and 9) Tension) can be obtained.

  In the graph of FIG. 12, the expansion rate (%) of the dicing tape 3 is shown on the vertical axis, and the amount of push up (mm) of the annular portion region 3B due to the upward movement of the expand ring 14 is shown on the horizontal axis. Further, FIG. 12 shows that the expansion rate according to the amount of push-up differs for each restriction position of the expansion restriction ring 16 as described later.

  Specifically, line A in FIG. 12 shows a change in expansion rate when the restriction position of the expansion restriction ring 16 is set to the first restriction position (see FIG. 8C). Further, a line B indicates a change in expansion rate when the restriction position of the expansion restriction ring 16 is set to the second restriction position (see FIG. 11).

  Further, a line C indicates a change in expansion rate when the restriction position of the expansion restriction ring 16 is set to the third restriction position. The third restricting position is a position on the side where the expansion restricting ring 16 is disposed relative to the first restricting position. As an example, the third restricting position may be located at the same position as the surface 4B of the frame 4 (see FIG. 3). The change of the expansion rate when setting 3 restricted positions is shown by line C. Further, line D indicates a change in expansion rate when the expansion restriction ring 16 is not used.

  In addition, the graph shown in FIG. 12 is an example of the expansion rate calculated based on the dimension 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 regulating opening 16B of the expansion regulating ring 16 is 338 mm, and the roller The arrangement diameter D3 of 36 is 323.2 mm. The expansion ratios of the lines A, B and C shown in FIG. 12 are calculated assuming that these dimensions and the diameter d of the roller 36 are 7 mm, and the expansion ratios of the line D assume these dimensions and the diameter d of the roller 36 5 mm. It is calculated. Further, a symbol x in FIG. 13 indicates a push-up amount (mm) of the annular portion region 3B due to the upward movement of the expand ring 14.

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

  First, when the expansion restricting ring 16 is at the third restricting position (see line C), the annular portion region 3B is pushed up by the upward movement of the expand ring 14, and the amount of pushing up is 1.5 mm (= the thickness of the frame 4). When reaching t), the annular region 3B contacts the lower edge 16A of the expansion restricting ring 16. The expansion rate immediately after the contact is higher than the expansion rate when the expansion restricting 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 the line A), the lower edge 16A of the expansion restricting ring 16 is in the annular portion region 3B prior to the expansion operation. Since it is in contact with the surface in advance, the expansion ratio from immediately after the expand ring 14 contacts the annular portion region 3B becomes higher than the expansion ratio (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), prior to the expansion operation, the lower edge portion 16A of the expansion restricting ring 16 presses the annular portion region 3B in advance. Therefore, the expansion rate exceeds 0% before starting the expansion operation. Therefore, the expansion rate in the case where the amount of push-up of the annular portion region 3B is the same becomes higher than the expansion rate (see line A) in the case of being set to the first restriction position.

  As described above, when the expansion restriction ring 16 is not applied by expanding the annular portion region 3B using the expand ring 14 in a state where the expansion restriction ring 16 is disposed at any one of the first to third restriction positions. In contrast to this, sufficient tension for dividing the wafer 1 into the chips 6 is obtained. In particular, when the expansion regulating ring 16 is disposed at the first regulation position on the same surface as the tape application surface 4A or at the second regulation position on the side where the expand ring 14 is disposed with respect to the tape application surface 4A, tape attachment As compared with the case where the expansion restricting ring 16 is disposed at the third restricting position on the side where the expansion restricting ring 16 is disposed rather than the surface 4A, high tension can be obtained immediately after raising the expand ring 14, so the wafer 1 can be more effectively It can be divided into chips 6.

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

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

  FIG. 14 shows, as an example, a change in expansion rate speed in the case where the push-up 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 higher the force for dividing the wafer 1 into chips 6.

  Line E in FIG. 14 shows the change in the lifting speed at a lifting amount of 0.00 mm to 20.00 mm. In other words, the line E indicates the rising movement speed of the expanding ring 14. According to the line E, the expand ring 14 moves upward at a constant speed (200 mm / sec) within the range of 0.00 mm to about 18.50 mm, and thereafter moves upward to 20.00 mm while decelerating.

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

  According to the expansion rate shown by lines F, G and H in FIG. 14, the speed increases according to the amount of push-up, and reaches a maximum (maximum expansion rate) when the amount of push-up reaches approximately 18.50 mm. After that, each descends.

  Here, when the restriction position by the expansion restriction ring 16 is set to the third restriction position (see line G), the expansion rate speed after the push-up amount exceeds about 3.00 mm applies the expansion restriction ring 16 If not (see line F), the maximum expansion rate is increased (from about 95% / sec to about 115% / sec). As a result, the tension generated in the dicing tape 3 increases more than the tension in the case where the expansion regulating ring 16 is not applied, so that the undivided problem described above can be solved.

  On the other hand, when the expansion restriction ring 16 is set to the first restriction position or the second restriction position (see the line H), the expansion rate speed in the case where the pushing amount of the annular portion region 3B is the same is the third restriction position. It becomes faster than setting it to (see line G). The increase in the maximum expansion rate is substantially equal to that when the third restriction position is set (see line G).

  Thus, by setting the expansion restricting ring 16 to the first restricting position or the second restricting position, the expansion rate (see FIG. 12) and the maximum expansion rate in the case where the push-up amount of the annular portion region 3B is made the same. Since (see FIG. 14) is faster than the case where it is set at the third restricted position, a large tension can be applied to the wafer 1 immediately after the start of expansion. Therefore, the undivided problem described above can be solved more effectively than when the third position is set.

  In the other dividing method shown in FIGS. 10 and 11, the position moved 3 mm from the first restricting position to the side where the expand ring 14 is disposed is set as the second restricting position, but the second restricting position It is not limited to the position. The second restriction position is preferably set to a position where an optimum tension can be applied with a small amount of pushing up to wafers of various chip sizes. The third restricting position is not limited to the position on the same plane as the surface 4B of the frame 4 and may be a position on the side where the expansion restricting ring 16 is disposed rather than the first restricting position.

  DESCRIPTION OF SYMBOLS 1 ... Wafer ... 2 ... Wafer unit ... 3 ... Dicing tape, 3A ... Central part area, 3B ... Annular part area, 3C ... Fixed part area, 3D ... Contact part, 3E ... Outer peripheral side area, 3F ... Inner peripheral side area 4, 4 frame 4, tape sticking surface 5, division planned line 6, chip 7, frame fixing member 8, expanding ring 14, expanding ring 16, expansion regulating ring 18, expansion holding ring 20 ... Expanding ring moving mechanism, 22 ... Expansion regulating ring moving mechanism, 28 ... Body ring, 30 ... Fitting portion, 32 ... Extended holding ring moving mechanism, 34 ... Control unit, 36 ... Rollers

Claims (8)

In a work dividing apparatus in which an outer peripheral portion of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than an outer diameter of a work, and the work attached to the dicing tape is divided into individual chips along dividing lines ,
It is an expand ring which is arranged on the back side opposite to the pasting surface of the work in the dicing tape and has an opening smaller than the inner diameter of the frame and larger than the outer diameter of the work. And expanding the annular portion region between the outer edge portion of the work and the inner edge portion of the frame by moving in a direction relatively approaching the dicing tape. With the ring,
An expansion restricting ring formed in a ring shape having an opening that is disposed on the same side as the pasting surface of the work in the dicing tape and that has an opening smaller than the inner diameter of the frame and larger than the outer diameter of the expand ring The expansion regulating ring which regulates expansion of an outer circumferential area located on an outer peripheral side of the annular section area at an outer peripheral side bordering on an abutting section in contact with the expansion regulating ring;
An expansion regulation ring moving mechanism for advancing and retracting the expansion regulation ring between a regulation position for regulating the expansion of the outer circumferential area and a retracted position retracted from the regulation position;
A work dividing apparatus comprising: The restricting position is a first restricting position on the same surface as the tape application surface to which the dicing tape of the frame is attached.
The workpiece dividing device according to claim 1. The restricting position is a second restricting position on the side where the expand ring is disposed with respect to the tape-sticking surface of the frame to which the dicing tape is stuck.
The workpiece dividing device according to claim 1. An expanding and holding ring formed in a ring shape having an elastically deformable fitting portion which is disposed on the back side of the dicing tape opposite to the pasting surface of the work and which is larger than the inner diameter of the frame. An expansion holding ring for holding the expansion state of the dicing tape by fitting the fitting portion to the surface of the frame after moving the expansion restriction ring from the restriction position to the retracted position by the restriction ring movement mechanism. And
The workpiece dividing device according to any one of claims 1 to 3. In a work dividing method in which an outer peripheral portion of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than an outer diameter of a work, and the work attached to the dicing tape is divided into individual chips along planned dividing lines ,
The outer edge portion of the dicing tape among the dicing tapes is moved by moving the expand ring disposed on the back surface side opposite to the pasting surface of the workpieces in the dicing tape relatively toward the dicing tape. An expansion step of pressing and expanding the annular region between the frame and the inner edge of the frame by the expanding ring;
When the expansion step is performed, the expansion regulation ring disposed on the same side as the pasting surface of the work in the dicing tape is brought into contact with the annular portion area at a regulation position to abut the expansion regulation ring An expansion restricting step of restricting expansion of an outer peripheral area located on the outer peripheral side bordering on the contact portion,
Work division method provided with The restricting position is a first restricting position on the same surface as the tape application surface to which the dicing tape of the frame is attached.
The work dividing method according to claim 5. The restricting position is a second restricting position on the side where the expand ring is disposed with respect to the tape-sticking surface of the frame to which the dicing tape is stuck.
The work dividing method according to claim 5. The expansion holding ring disposed on the back side opposite to the pasting surface of the work in the dicing tape is formed on the outer peripheral portion of the expansion holding ring by moving in a direction relatively approaching the dicing tape. And an expanded state holding step of holding the expanded state of the dicing tape by fitting the elastically deformable fitting portion on the surface of the frame.
A work dividing method according to any one of claims 5 to 7.

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