Workpiece dividing device and workpiece dividing method

Abstract

A workpiece dividing device and a workpiece dividing method are provided that can solve the problem of non-division of a planned dividing line that occurs when the chip size is small. [Solution] The work division device comprises an expanding ring that presses against the back surface of the dicing tape to expand the dicing tape, and an expansion restriction ring that is formed in a ring shape with an opening that is larger than the outer diameter of the expanding ring and against which the dicing tape abuts when the dicing tape is expanded by the expanding ring.

Description

[Technical field]

[0001] The present invention relates to a work dividing device and a work dividing method, and more particularly to a work dividing device and a work dividing method for dividing a work such as a semiconductor wafer into individual chips along planned division lines. [Background technology]

[0002] Conventionally, in the manufacture of semiconductor chips (hereinafter referred to as chips), a work division device has been known which divides a semiconductor wafer (hereinafter referred to as wafer), into which a division line has been formed in advance by half-cutting with a dicing blade or by forming a modified region by laser irradiation, into individual chips along the division line (see Patent Document 1, etc.).

[0003] FIG. 22 is an explanatory diagram of a wafer unit 2 to which a disk-shaped wafer 1 to be divided by a work dividing device is attached, FIG. 22(A) is an oblique view of the wafer unit 2, and FIG. 22(B) is a cross-sectional view of the wafer unit 2.

[0004] The wafer 1 is attached to the center of a dicing tape (also called an expansion tape or adhesive sheet) 3 that is approximately 100 μm thick and has an adhesive layer formed on one side, and the dicing tape 3 has its outer periphery fixed to a rigid ring-shaped frame (hereinafter referred to as the frame) 4.

[0005] In the workpiece dividing device, the frame 4 of the wafer unit 2 is fixed by a frame fixing member (also called a frame fixing mechanism) 7 shown by a two-dot chain line. After this, an expand ring (also called a push-up ring) 8 shown by a two-dot chain line is moved upward from below the wafer unit 2, and the dicing tape 3 is pressed by this expand ring 8 to expand radially. The tension of the dicing tape 3 generated at this time is applied to the division lines 5 of the wafer 1, so that the wafer 1 is divided into individual chips 6. The division lines 5 are formed in the X direction and the Y direction that intersect with each other. Regarding the division lines 5, when the number of lines parallel to the X direction and the number of lines parallel to the Y direction are the same and the intervals in each direction are equal, the shape of the divided chips 6 is a square. When the number of lines parallel to the X direction and the number of lines parallel to the Y direction are different and the intervals in each direction are equal, the shape of the divided chips 6 is a rectangle.

[0006] Incidentally, the dicing tape 3 is a flexible material with a low Young's modulus. Therefore, in order to smoothly divide the wafer 1 into individual chips 6, it is conceivable to expand the dicing tape 3 by cooling the dicing tape 3 and increasing its spring constant.

[0007] The tape expanding device (workpiece dividing device) of Patent Document 2 is equipped with a cold air supplying means. According to Patent Document 2, the cold air supplying means is operated to supply cold air into the processing space, and the processing space is cooled to, for example, 0°C or less, thereby cooling the dicing tape.

[0008] Meanwhile, the chip separation device (workpiece dividing device) of Patent Document 3 focuses on the anisotropy of the dicing tape and is equipped with a film surface support mechanism to uniformly expand the dicing tape while taking this anisotropy into account. This film surface support mechanism is equipped with multiple support mechanisms that are independent in the circumferential direction, and the relative heights of the multiple support mechanisms are individually controlled to adjust the tension of the dicing tape, thereby independently controlling the elongation of the dicing tape in the X and Y directions.

[0009] In this specification, the circular area of ​​the dicing tape 3 to which the wafer 1 is attached is referred to as the central area 3A, the doughnut-shaped area between the outer edge of the central area 3A and the inner edge of the frame 4 is referred to as the annular area 3B, and the doughnut-shaped area of ​​the outermost periphery fixed to the frame 4 is referred to as the fixed area 3C. The annular area 3B is the area that is expanded by being pressed against the expand ring 8.

[0010] It is known that the force required to divide the wafer 1, i.e., the tension that must be generated in the annular region 3B to divide the wafer 1, must increase as the number of dividing lines 5 increases. Regarding the number of dividing lines 5, for example, when the chip size is 5 mm on a wafer 1 having a diameter of 300 mm, approximately 120 dividing lines 5 (60 in each of the X and Y directions) are formed, and when the chip size is 1 mm, approximately 600 dividing lines 5 are formed. Therefore, the tension that must be generated in the annular region 3B must increase as the chip size decreases. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2016-149581 A [Patent Document 2] JP 2016-12585 A [Patent Document 3] JP 2012-204747 A Summary of the Invention [Problem to be solved by the invention]

[0012] Incidentally, 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 according to the SEMI (Semiconductor Equipment and Materials International) standards (G74-0699 Specifications for Tape Frames for 300 mm Wafers). According to this standard, as shown in the longitudinal section of the wafer unit 2 in FIG. 23, an annular region 3B having a width dimension of 25 mm exists between the outer edge of the wafer 1 and the inner edge of the frame 4. Also, as shown in the longitudinal section of the essential part of the workpiece dividing device shown in FIGS. 24(A) and 24(B), the frame fixing member 7 for fixing the frame 4 is installed at a position spaced outward from the annular 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 region 3B expanded by the expand ring 8.

[0013] Therefore, the force dividing the wafer 1 generated by the rising movement of the expand ring 8 is decomposed into three forces: (i) a force to expand the entire area of ​​the annular region 3B, (ii) a force to divide the wafer 1 into chips 6, and (iii) a force to expand the dicing tape 3 between adjacent chips 6.

[0014] As shown in the operation diagram of the workpiece dividing device in Figures 25(A) to (E), when the expand ring 8 comes into contact with the annular region 3B of the dicing tape 3 and the dicing tape 3 starts to expand due to the rising movement of the expand ring 8 (Figure 25(A)), the annular region 3B, which has the lowest spring constant, starts to expand first (Figure 25(B)). As a result, tension is generated in the annular region 3B, and when this tension increases to a certain extent, the increased tension is transmitted to the wafer 1, and the division of the wafer 1 into chips 6 begins (Figure 25(C)). When the wafer 1 is divided into individual chips 6, the expansion of the annular region 3B and the expansion of the dicing tape 3 between the chips proceed simultaneously (Figures 25(D) to (E)).

[0015] In the conventional workpiece dividing device, when the chip size of a wafer 1 having a diameter of 300 mm is 5 mm or more, the wafer 1 can be divided into individual chips 6 without any problem by the tension generated in the annular region 3B. However, as the circuit patterns formed on the wafer 1 become finer, chips with smaller chip sizes of 1 mm or less have appeared. In this case, the force required to divide the wafer 1 increases due to an increase in the number of division lines 5 for dividing the wafer 1, and a force greater than the tension caused by the expansion of the annular region 3B may be required. As a result, as shown in the vertical cross-sectional view of the wafer unit 2 in FIG. 26, a problem occurs in that even after the expansion operation by the expand ring 8 is completed, some of the division lines 5 formed on the wafer 1 remain undivided.

[0016] Such a problem of the division lines 5 not being divided cannot be solved even if the expansion amount or expansion speed of the dicing tape 3 is increased. For example, if the expansion amount of the dicing tape 3 is increased, the annular region 3B starts to undergo plastic deformation. Since the spring constant of the annular region 3B during plastic deformation is smaller than the spring constant during elastic deformation, no tension is generated to divide the wafer 1 into individual chips 6 in the region of the annular region 3B that exceeds the elastic deformation. On the other hand, even if the expansion speed of the dicing tape 3 is increased, a part of the annular region 3B starts to undergo plastic deformation, so no tension is generated to divide the wafer 1 into individual chips 6. This is because the frequency response of the dicing tape 3 is low, and therefore the force is not transmitted to the entire dicing tape 3 without time lag.

[0017] In order to solve the problem of non-division of the intended division lines 5, Patent Document 2 addresses this by cooling the dicing tape and increasing the spring constant of the dicing tape, but this is not sufficiently effective for recent small chips of 1 mm or less.

[0018] Furthermore, the chip separation device of Patent Document 3 can independently control the elongation of the dicing tape in the X and Y directions, but cannot apply to the wafer a force greater than the tension caused by the expansion of the annular region, and therefore cannot solve the problem of non-division along the intended division lines.

[0019] The present invention has been made in consideration of such problems, and aims to provide a work division device and a work division method that can solve the problem of non-division of the planned division line that occurs when the chip size is small. [Means for solving the problem]

[0020] In order to achieve the object of the present invention, the work division device of the present invention comprises an outer periphery of a dicing tape fixed to a ring-shaped frame having an inner diameter larger than the outer diameter of the work, and divides the work affixed to the dicing tape into individual chips along a planned division line, the work division device comprising: a frame fixing member for fixing the ring-shaped frame; an expanding ring which is arranged on the back side of the dicing tape opposite the affixing surface of the work, and is formed in a ring shape smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the work, and which generates tension in the dicing tape by pressing the back side of the dicing tape to expand the dicing tape; and an expansion restricting ring which is arranged on the same side of the dicing tape as the affixing surface of the work, and is formed in a ring shape with an opening smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the expanding ring, against which the dicing tape comes into contact when the dicing tape is expanded by the expanding ring.

[0021] According to the workpiece dividing device of the present invention, when the expansion of the dicing tape is started by the expanding ring, the dicing tape comes into contact with the expansion restricting ring during the expansion of the dicing tape. At this time, the dicing tape is divided into an outer peripheral region located on the outer periphery side and an inner peripheral region located on the inner periphery side, with the abutment part abutting the expansion restricting ring as a boundary. Then, in the expanding operation by the expanding ring after the dicing tape comes into contact with the expansion restricting ring, the expansion of the outer peripheral region is restricted by the expansion restricting ring, and only the inner peripheral region is expanded. In other words, the tension of the spring constant of the inner peripheral region, which is larger than the spring constant of the dicing tape, is applied to the workpiece. As a result, the tension applied to the workpiece increases, and the problem of non-division of the division line that occurs when the chip size is a small chip can be solved.

[0022] In one form of the present invention, the expansion control ring has a tape position control portion that abuts the dicing tape when the dicing tape is expanded by the expanding ring, and it is preferable that the tape position control portion is positioned on the same plane as the tape application surface to which the dicing tape of the ring-shaped frame is applied, or on the side where the expanding ring is positioned relative to the same plane.

[0023] In one form of the present invention, the expansion control ring preferably comprises a frame fixing portion fixed to a ring-shaped frame and a convex rib portion protruding toward the dicing tape along the peripheral edge of the opening of the expansion control ring, and the tape position control portion is preferably formed by the tip of the convex rib portion.

[0024] In one aspect of the present invention, it is preferable that the expansion restriction ring is provided with a frame fixing portion arranged on the same side as the workpiece attachment surface of the dicing tape, and abuts against the ring-shaped frame to fix the ring-shaped frame.

[0025] According to one aspect of the present invention, since the expansion control ring also has the function of fixing the ring-shaped frame, the number of parts of the work division device can be reduced, and the frame can be fixed by the frame fixing portion by assembling the expansion control ring to the work division device.

[0026] In one aspect of the present invention, the expansion regulating ring is a frame fixing member arranged on the same side of the dicing tape as the workpiece attachment surface, and it is preferable that the expansion regulating ring is removably fixed to the frame fixing member that fixes the ring-shaped frame via the expansion regulating ring.

[0027] According to one aspect of the present invention, when the chip size is a small chip, the expansion restriction ring can be attached to the frame fixing member, and when the chip size is a large chip, the expansion restriction ring can be removed from the frame fixing member. In other words, even if an existing work division device does not have an expansion restriction ring, by attaching an expansion restriction ring to the frame fixing member of the work division device, it is possible to divide a work with a small chip size.

[0028] In one aspect of the present invention, the opening of the expansion restriction ring is preferably formed in a circular shape.

[0029] According to one aspect of the present invention, in the mutually intersecting X and Y directions, for example, in the case of a workpiece to be divided into square chips having the same dimensions in the X and Y directions, it is preferable to use an expansion restriction ring having a circular opening in the case of a workpiece having the same number (density) of division lines in the X and Y directions. Similarly, in the case of a workpiece attached to a dicing tape having the same spring constant in the X and Y directions, it is preferable to use an expansion restriction ring having a circular opening. This allows uniform tension to be applied to the peripheral portion of the workpiece from the expanded inner peripheral region, thereby realizing a suitable division ability for such a workpiece.

[0030] In one aspect of the present invention, the opening of the expansion restriction ring is preferably formed in an elliptical shape.

[0031] According to one aspect of the present invention, in the case of a workpiece to be divided into rectangular chips having different dimensions in the X and Y directions, which are perpendicular to each other, for example, in the case of a workpiece having different numbers (densities) of division lines in the X and Y directions, it is preferable to use an expansion restriction ring having an elliptical opening.

[0032] In this case, the direction of the minor axis of the ellipse is aligned parallel to the direction in which the density of the division lines is high (the direction along the short side of the chip, the direction in which the chip is dense), and the direction of the major axis of the ellipse is aligned parallel to the direction in which the density of the division lines is low (the direction along the long side of the chip, the direction in which the chip is dense). As a result, the inner peripheral region located in the direction in which the density of the division lines is high has a large spring constant, so that it is possible to impart to the workpiece a suitable tension for dividing the large number of division lines. On the other hand, the annular region located in the direction in which the density of the division lines is low has a small spring constant, but is able to impart to the workpiece a suitable tension for dividing the small number of division lines. Therefore, it is possible to realize a suitable dividing ability for such a workpiece.

[0033] In addition, in the case of a workpiece attached to an anisotropic dicing tape in which the spring constant in the X direction is different from the spring constant in the Y direction, it is also preferable to use an elliptical expansion restriction ring.

[0034] In this case, the direction of the minor axis of the ellipse is aligned parallel to the direction of the small spring constant, and the direction of the major axis of the ellipse is aligned parallel to the direction of the large spring constant. As a result, when the inner peripheral region expands, the spring constant of the inner peripheral region located in the direction parallel to the direction of the small spring constant becomes high and approaches the spring constant of the inner peripheral region located in the direction parallel to the direction of the major axis of the ellipse, so that a substantially uniform tension can be applied to the workpiece from the inner peripheral region. Therefore, it is possible to realize an appropriate dividing ability for a workpiece mounted on an anisotropic dicing tape with different spring constants in the X and Y directions.

[0035] In order to achieve the object of the present invention, the work dividing method of the present invention is a method in which the outer periphery of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than the outer diameter of the work, and the work attached to the dicing tape is divided into individual chips along planned division lines, the method comprising: an expansion step in which the dicing tape is pressed to expand it, thereby generating tension in the dicing tape; an expansion restriction step in which, when the dicing tape is expanded, the expansion of an outer periphery region of the dicing tape located on the outer periphery side is restricted; and a division step in which the expansion of the dicing tape is continued excluding the outer periphery region, thereby dividing the work into individual chips.

[0036] According to the workpiece dividing method of the present invention, it is possible to solve the problem of non-division of the dividing line that occurs when the chip size is small. Effect of the Invention

[0037] According to the present invention, it is possible to solve the problem of non-division of planned division lines that occurs when the chip size is small. [Brief description of the drawings]

[0038] [Figure 1] FIG. 1 is a structural diagram of a main part of a workpiece dividing device according to a first embodiment; [Diagram 2] FIG. 2 is an enlarged perspective view of a main part of the workpiece dividing device shown in FIG. [Diagram 3] FIG. 1 is a cross-sectional view of a wafer unit showing the shape of the annular region during expansion. [Figure 4] Enlarged cross-sectional view of the annulus region during expansion [Diagram 5] Flowchart of wafer division method [Figure 6] FIG. 13 is a structural diagram of a main part of a workpiece dividing device according to a second embodiment. [Figure 7] FIG. 7 is an enlarged perspective view of a main part of the workpiece dividing device shown in FIG. [Figure 8] Enlarged cross-sectional view of the annulus region during expansion [Figure 9] FIG. 1 is a plan view of an expansion restriction ring having a circular expansion restriction opening and a wafer unit superimposed on each other. [Figure 10] FIG. 1 is a plan view of an expansion restriction ring having an elliptical expansion restriction opening and a wafer unit superimposed on each other. [Figure 11] A graph showing the expansion rate of the annular region and the inner peripheral region when an expansion restriction ring is used and when it is not used. [Figure 12] A graph showing the chip split ratio with and without the extended regulation ring. [Figure 13] 11 is a cross-sectional view of a main part of a workpiece dividing device according to a third embodiment. [Figure 14] FIG. 14 is an enlarged cross-sectional view of a main part of the workpiece dividing device shown in FIG. [Figure 15] 13 is a cross-sectional view of a main part of a workpiece dividing device according to a fourth embodiment. [Figure 16] FIG. 16 is an enlarged cross-sectional view of a main part of the workpiece dividing device shown in FIG. [Figure 17] FIG. 7 is an explanatory diagram showing a first modified example of the expansion restriction ring shown in FIG. [Figure 18] FIG. 7 is an explanatory diagram showing a second modified example of the expansion restriction ring shown in FIG. [Figure 19] Graph showing change in expansion rate against thrust amount [Figure 20] Schematic diagram showing the operation during the expansion division process [Figure 21] Graph showing change in expansion rate speed against thrust speed [Figure 22] An explanatory diagram of a wafer unit with a wafer attached [Figure 23] Vertical cross-sectional view of the wafer unit [Figure 24] Side view of the main part of the workpiece dividing device [Diagram 25] Operation diagram of workpiece dividing device [Figure 26] A longitudinal sectional view of a wafer unit into which wafers are separated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Hereinafter, preferred embodiments of the workpiece dividing device and the workpiece 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 made to the following embodiments within the scope of the present invention.

[0040] [Workpiece dividing device 10A of the first embodiment] Fig. 1 is a vertical sectional view of a main part of the work division device 10A according to the first embodiment, and Fig. 2 is an enlarged perspective view of a main part of the work division device 10A. Note that the size of the wafer unit divided by the work division device 10A is not limited, but in the embodiment, a wafer unit 2 on which a wafer 1 having a diameter of 300 mm is mounted as shown in Fig. 23 is exemplified.

[0041] The workpiece dividing device 10A is a device that divides a wafer 1, on which planned dividing lines 5 are formed, into individual chips 6 along the planned dividing lines 5. A plurality of planned dividing lines 5 are formed in the X direction and the Y direction that intersect with each other. In the embodiment, a wafer 1 in which the number of planned dividing lines 5 parallel to the X direction and the number of planned dividing lines 5 parallel to the Y direction are 300 each and are spaced equally apart from each other, that is, a wafer 1 to be divided into chips 6 with a chip size of 1 mm, is illustrated.

[0042] 1 and 2, the wafer 1 is attached to the center of a dicing tape 3 whose outer periphery is fixed to a frame 4. The dicing tape 3 has a central region 3A that is circular in plan view to which the wafer 1 is attached, and an annular region 3B that is doughnut-shaped in plan view between the outer edge of the central region 3A and the inner edge of the frame 4.

[0043] The thickness of the wafer 1 is, for example, about 50 μm. For example, a PVC (polyvinyl chloride) tape is used as the dicing tape 3. The wafer 1 may be attached to the dicing tape 3 via a film-like adhesive such as DAF (Die Attach Film). For example, a PO (polyolefin)-based film-like adhesive may be used as the film-like adhesive.

[0044] The workpiece dividing device 10A includes an expansion restricting ring 16 having a frame fixing portion 12 for fixing the frame 4, and an expand ring 14 that comes into contact with the annular region 3B of the dicing tape 3 from below.

[0045] The expand ring 14 is disposed on the back surface of the dicing tape 3 opposite to the surface to which the wafer 1 is attached, and is formed in a ring shape having an expansion opening 14A smaller than the inner diameter (350 mm) of the frame 4 and larger than the outer diameter (300 mm) of the wafer 1. The expand ring 14 presses the back surface of the annular region 3B of the dicing tape 3 to expand the annular region 3B. That is, the expand ring 14 is moved upward in a direction B intersecting with the in-plane direction indicated by the arrow A of the dicing tape 3 relative to the annular region 3B. As a result, the annular region 3B is pushed up by the expand ring 14 and radially expanded. The expand ring 14 may be fixed and the wafer unit 2 moved downward in the direction of the arrow C to expand the annular region 3B by the expand ring 14.

[0046] The expansion restricting ring 16 is composed of an expansion restricting portion 17 and a frame fixing portion 12. The frame fixing portion 12 is disposed on the same side of the dicing tape 3 as the attachment surface of the wafer 1, and the frame 4 is fixed to its underside 12A. The expansion restricting portion 17 extends from the frame fixing portion 12 toward the center of the expansion restricting ring 16 beyond the frame 4. The annular region 3B of the dicing tape 3 abuts against the expansion restricting portion 17 when expanded by the expand ring 14. The boundary between the frame fixing portion 12 and the expansion restricting portion 17 is indicated by the symbol D in Figs. 1 and 2.

[0047] The expansion restricting portion 17 is formed in a ring shape having an expansion restricting opening (opening) 16A that is smaller than the inner diameter (350 mm) of the frame 4 and larger than the outer diameter of the expand ring 14.

[0048] Fig. 3 is a vertical cross-sectional view of the wafer unit 2, showing the shape of the annular region 3B in the middle of being expanded by the expand ring 14. Fig. 4 is an enlarged cross-sectional view of the annular region 3B in the middle of being expanded.

[0049] 3 and 4, when the annular region 3B is expanded by the expand ring 14, the annular region 3B abuts against the expansion restricting portion 17. Specifically, the annular region 3B abuts against the inner edge portion 16B of the expansion restricting portion 17.

[0050] 1, the diameter of the expansion restricting opening 16A is set to 338 mm. As a result, the width of the outer circumferential region 3E, the expansion of which is restricted by the expansion restricting portion 17, is set to 6 mm, and the width of the inner circumferential region 3F of the annular region 3B excluding the outer circumferential region 3E is set to 19 mm.

[0051] Here, the inner peripheral region 3F, the expansion of which is not restricted by the expansion restricting portion 17, of the annular region 3B is the region that substantially contributes to the division of the wafer 1. That is, as the width dimension of the inner peripheral region 3F is reduced, the spring constant of the inner peripheral region 3F increases, so that the tension applied from the inner peripheral region 3F to the wafer 1 can be increased. Therefore, it is preferable to set the width dimension of the inner peripheral region 3F according to the number of the division lines 5 and the size of the chips 6.

[0052] Hereinafter, a workpiece dividing method by the workpiece dividing device 10A will be described with reference to the flowchart of FIG.

[0053] First, in step S100 of FIG. 5, as shown in FIG. 1, the frame 4 of the wafer unit 2 is fixed by the frame fixing portion 12 of the expansion restriction ring 16 (fixing step).

[0054] Next, in step S110 in FIG. 5, the expand ring 14 is moved upward in the direction of arrow B from the position in FIG. 1, and expansion of the entire area of ​​the annular area 3B begins (expansion step).

[0055] Next, in step S120 of Fig. 5, when the upward movement amount of the expand ring 14 exceeds the thickness of the frame 4, the annular region 3B abuts against the expansion restricting portion 17. At this time, as shown in Fig. 4, the annular region 3B is divided into an outer periphery region 3E located on the outer periphery side and an inner periphery region 3F located on the inner periphery side, with a contact portion 3D abutting against the inner edge portion 16B of the expansion restricting portion 17 as a boundary. Then, of the annular region 3B, the expansion of the outer periphery region 3E is restricted by the expansion restricting portion 17 (expansion restricting step).

[0056] 5, the upward movement of the expand ring 14 is continued, and the inner peripheral region 3F of the annular region 3B, excluding the outer peripheral region 3E, is continuously expanded, thereby dividing the wafer 1 into individual chips 6 (dividing step). After this, the upward movement of the expand ring 14 is stopped.

[0057] In the dividing step (S130), in the expansion operation by the expand ring 14 after the annular region 3B abuts against the inner edge portion 16B of the expansion restricting portion 17, the expansion of the outer circumferential region 3E is restricted by the expansion restricting portion 17, and only the inner circumferential region 3F expands. In other words, the tension of the spring constant of the inner circumferential region 3F, which is larger than the spring constant of the annular region 3B, is applied to the wafer 1.

[0058] Specifically, the length of the annular region 3B that contributes to the division of the wafer 1 is shortened from 25 mm (width of the annular region 3B) to 19 mm (width of the inner peripheral region 3F), and the spring constant increases inversely proportionally. As a result, even if only the inner peripheral region 3F is expanded, the spring constant of the inner peripheral region 3F is greater than that of the annular region 3B, so that a tension sufficient to divide the wafer 1 into individual chips 6 can be applied even if the chip size is small (1 mm). Therefore, the work dividing device 10A can solve the problem of not dividing the planned division line that occurs when the chip size is small (1 mm).

[0059] The inner edge 16B of the expansion restricting portion 17, which is in line contact with the adhesive layer of the annular region 3B, is surface-treated to have an arithmetic mean roughness (Ra) of 1.6 (μm), for example. This prevents the inner edge 16B and the annular region 3B from slipping relative to each other due to friction between them. The inner edge 16B is also chamfered to C0.2 (0.2 mm Chamfer), for example. This prevents the annular region 3B from breaking due to the reaction force when it receives an expansion force from the annular region 3B.

[0060] In addition, the expansion regulating ring 16 of the work division device 10A is equipped with a frame fixing portion 12 and therefore also has the function of fixing the frame 4, so that the number of parts of the work division device 10A can be reduced, and the frame 4 can be fixed by the frame fixing portion 12 by assembling the expansion regulating ring 16 to the work division device 10A.

[0061] The expand ring 14 of the workpiece dividing device 10A is configured in a ring shape having an expansion opening 14A that surrounds the wafer 1 of the wafer unit 2 fixed to the frame fixing part 12. The expansion restricting part 17 is provided with an expansion restricting opening 16A that surrounds the ring-shaped expand ring 14. As a result, according to the workpiece dividing device 10A, the ring-shaped expand ring 14 uniformly expands the entire annular region 3B, and the annular region 3B is evenly line-contacted with the inner edge 16B of the expansion restricting opening 16A of the expansion restricting part 17. This makes it possible to reliably restrict the expansion of the outer circumferential region 3E.

[0062] [Workpiece dividing device 10B according to the second embodiment] Fig. 6 is a vertical sectional view of a main part of a work division device 10B according to the second embodiment, and Fig. 7 is an enlarged perspective view of a main part of the work division device 10B. As for the wafer unit processed by the work division device 10B, the wafer unit 2 on which a wafer 1 having a diameter of 300 mm is mounted, as shown in Fig. 23, is exemplified. Also, the same reference numerals are used to denote the same or similar members as those in the work division device 10A shown in Figs. 1 and 2 and will be described.

[0063] The difference between the work division device 10A of the first embodiment and the work division device 10B of the second embodiment is that the frame fixing member 7 (see FIG. 24: an existing frame fixing member) and the expansion restriction ring 18 are constructed separately, and the expansion restriction ring 18 is provided so as to be freely attached and detached to the frame fixing member 7. The attachment and detachment structure of the expansion restriction ring 18 to the frame fixing member 7 is not particularly limited, but as an example, it may be a fastening structure using a bolt, or a clamping structure using a clamping mechanism.

[0064] The frame fixing member 7 is disposed on the same side of the dicing tape 3 as the attachment surface of the wafer 1. The frame fixing member 7 is disposed at a position spaced outward from the annular 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 region 3B expanded by the expand ring 14. As shown in Fig. 7, the frame fixing member 7 has a ring-like shape, but the shape is not particularly limited and may be any shape that allows the expansion restricting ring 18 to be detachably attached.

[0065] The expansion restricting ring 18 has an expansion restricting opening (opening) 18A that is smaller than the inner diameter (350 mm) of the frame 4 and larger than the outer diameter of the expand ring 14. The diameter of this expansion restricting opening 18A is also 338 mm.

[0066] FIG. 8 is a vertical cross-sectional view of the wafer unit 2, showing the shape of the annular region 3B in the middle of being expanded by the expand ring 14. As shown in FIG.

[0067] 8, the annular region 3B comes into contact with an inner edge portion 18B of the expansion restriction ring 18 during expansion by the expand ring 14. As a result, the expansion of an outer circumferential region 3E between a contact portion 3D that comes into contact with the inner edge portion 18B and the inner edge portion of the frame 4 is restricted by the expansion restriction ring 18.

[0068] Next, a workpiece dividing method by the workpiece dividing device 10B will be described, which is substantially the same as the workpiece dividing method by the workpiece dividing device 10A.

[0069] First, as shown in FIG. 6, the frame 4 of the wafer unit 2 is fixed to the frame fixing member 7 via the expansion restriction ring 18 (fixing step).

[0070] Next, the expand ring 14 is moved upward in the direction of arrow B from the position in FIG. 6, and expansion of the entire area of ​​the annular area 3B begins (expansion step).

[0071] Next, when the upward movement of the expand ring 14 exceeds the thickness of the frame 4, the annular region 3B abuts against the inner edge 18B of the expansion restriction ring 18, restricting the expansion of the outer periphery region 3E located on the outer periphery side of the annular region 3B (expansion restriction process). At this time, as shown in Fig. 8, the annular region 3B is divided into an outer periphery region 3E located on the outer periphery side and an inner periphery region 3F located on the inner periphery side, with the abutment portion 3D abutting against the inner edge 18B as the boundary.

[0072] Next, the upward movement of the expand ring 14 is continued, and the inner peripheral region 3F of the annular region 3B, excluding the outer peripheral region 3E, is continuously expanded, thereby dividing the wafer 1 into individual chips 6 (dividing step). After this, the upward movement of the expand ring 14 is stopped.

[0073] In the dividing step, in the expanding operation by the expand ring 14 after the annular region 3B abuts against the inner edge 18B of the expansion restriction ring 18, the expansion of the outer circumferential region 3E is restricted by the expansion restriction ring 18, and only the inner circumferential region 3F is expanded. In other words, tension of the spring constant of the inner circumferential region 3F, which is larger than the spring constant of the annular region 3B, is applied to the wafer 1. As a result, according to the work dividing device 10B, like the work dividing device 10A, it is possible to solve the problem of non-division of the intended dividing line that occurs when the chip size is small (1 mm).

[0074] Furthermore, when the annular region 3B is expanded by the expand ring 14, the expansion restriction ring 18 restricts the expansion of the outer circumferential region 3E while being sandwiched between the frame fixing member 7 and the frame 4. That is, even if the inner diameter (e.g., 361 mm) of the frame fixing member 7 is larger than the inner diameter of the frame 4, which is 350 mm, by separately providing the expansion restriction ring 18 with an expansion restriction opening 18A having a diameter of 338 mm, it is possible to obtain an effect equivalent to that obtained when the inner diameter of the frame fixing member 7 is less than 350 mm. That is, it is possible to obtain an effect equivalent to that of the expansion restriction ring 16 of the first embodiment (see Figs. 1 and 2).

[0075] In addition, in the work division device 10B, it is preferable to prepare in advance a plurality of expansion restriction rings 18 with different diameters (inner diameters) of the expansion restriction opening 18A. This allows the expansion restriction ring 18 with the inner diameter designated in advance as a processing condition to be selected and used. In addition, since the expansion restriction ring 18 can be retrofitted to an existing (shipped) work division device that does not have the expansion restriction ring 18, it becomes possible to process chips from large to small using the existing work division device. In addition, in the case of a large chip, the expansion restriction ring 18 can be removed from the existing work division device. In addition, the diameter (inner diameter) of the expansion restriction opening 18A can be exemplified as 346 mm, 342 mm, and 334 mm, in addition to 338 mm.

[0076] Incidentally, as explained above, the force required to divide the wafer 1 must increase as the number of dividing lines 5 formed on the wafer 1 increases. However, depending on the wafer, in the X and Y directions that intersect with each other, the number of dividing lines 5 parallel to the X direction and the number of dividing lines 5 parallel to the Y direction may be the same (see FIG. 9), or the number of dividing lines 5 parallel to the X direction and the number of dividing lines 5 parallel to the Y direction may be different (see FIG. 10).

[0077] FIG. 9 is a plan view of the expansion restriction ring 20 having a circular expansion restriction opening 20A and the wafer unit 2 superimposed thereon. The wafer 22 shown in FIG. 9 is a wafer in which the number of division lines 5 parallel to the X direction and the number of division lines 5 parallel to the Y direction are equal and the intervals between them are equal, and the shape of the divided chips 24 is a square with the same dimensions in the X direction and the Y direction. That is, the wafer 22 shown in FIG. 9 is a wafer in which the density of the division lines 5 is equal in the X direction and the Y direction. In order to smoothly divide such a wafer 22, it is preferable to use an expansion restriction ring 20 with a circular expansion restriction opening 20A. That is, the wafer 22 and the expansion restriction opening 20A are circular, and the inner peripheral side region 3F of a doughnut shape in plan view surrounded by the outer edge of the wafer 22 and the inner edge of the expansion restriction opening 20A has the same width dimension e at any position in the circumferential direction.

[0078] This allows uniform tension to be applied from the expanding inner peripheral region 3F to the peripheral edge of the wafer 22. That is, by using the expansion restricting ring 20 having the circular expansion restricting opening 20A, it is possible to apply a suitable tension to the wafer 22 for dividing the wafer 22 having an equal density of the dividing lines 5 in the X direction and the Y direction. Note that an equal density of the dividing lines 5 in the X direction and the Y direction is equivalent to an equal density of the chips 6 in the X direction and the Y direction.

[0079] Fig. 10 is a plan view of the expansion restriction ring 26 having an elliptical expansion restriction opening 26A and the wafer unit 2 superimposed thereon. The wafer 28 shown in Fig. 10 is a wafer in which the number of division lines 5 parallel to the Y direction is greater than the number of division lines 5 parallel to the X direction, and the shape of the chips 30 to be divided is a rectangle whose dimension in the X direction is short and whose dimension in the Y direction is long. That is, the wafer 28 shown in Fig. 10 is a wafer in which the density of the division lines 5 (density of chips 6) differs between the X direction and the Y direction. To smoothly divide such a wafer 28, it is preferable to use an expansion restriction ring 26 having an elliptical expansion restriction opening 26A.

[0080] In this case, the direction of the minor axis a of the ellipse of the expansion restriction opening 26A is aligned parallel to the X direction in which the density of the planned division lines 5 is high (the direction in which the density of the chip 30 is high, the direction parallel to the short side of the chip 30), and the direction of the major axis b of the ellipse is aligned parallel to the Y direction in which the density of the planned division lines 5 is low (the direction in which the density of the chip 30 is low, the direction parallel to the long side of the chip 30).

[0081] As a result, the inner peripheral region 3FA located in a direction parallel to the X direction where the dividing lines 5 are denser has a smaller width and a higher spring constant, so that it is possible to apply a suitable tension to the wafer 28 for dividing the dividing lines 5 in the X direction where the dividing lines 5 are denser. On the other hand, the inner peripheral region 3FB located in a direction parallel to the Y direction where the dividing lines 5 are sparser does not have a smaller width and has a smaller spring constant, but it is possible to apply a suitable tension to the wafer 28 for dividing the dividing lines 5 in the Y direction where the dividing lines 5 are sparser. Therefore, it is possible to realize a suitable dividing ability for a wafer 28 in which the densities of the dividing lines 5 differ between the X direction and the Y direction.

[0082] Dicing tapes 3 may have the same spring constant in the X direction and the same spring constant in the Y direction, or may have a difference between the spring constant in the X direction and the spring constant in the Y direction due to the tape production direction, resulting in a difference in the way they stretch in the X direction and the Y direction. In principle, the tape tends to stretch more easily in a direction parallel to the tape production direction and less easily in a direction intersecting the tape production direction.

[0083] Considering the elongation characteristics of the dicing tape 3, in the case of a dicing tape 3 in which the spring constant in the X direction is equal to the spring constant in the Y direction, it is preferable to use an expansion restricting ring 20 with a circular expansion restricting opening 20A as shown in Fig. 9. This makes the amount of elongation of the inner peripheral region in the X direction and the amount of elongation in the Y direction during expansion equal, so that a uniform tension can be applied to the wafer from the inner peripheral region 3F.

[0084] On the other hand, in the case of a dicing tape 3 having anisotropy in which the spring constant in the X direction is different from the spring constant in the Y direction, it is preferable to use an expansion restriction ring 26 having an elliptical expansion restriction opening 26A as shown in FIG. 10.

[0085] In this case, the direction of the minor axis a of the ellipse is aligned parallel to the X direction in which the spring constant is small, and the direction of the major axis b of the ellipse is aligned parallel to the Y direction in which the spring constant is large. As a result, when the inner peripheral region is expanded, the spring constant of the inner peripheral region 3FA located in the X direction parallel to the direction in which the spring constant is small becomes high and approaches the spring constant of the inner peripheral region 3FB located in the direction parallel to the major axis b of the ellipse, so that the inner peripheral regions 3FA and 3FB can apply substantially uniform tension to the wafer. Therefore, it is possible to realize a suitable dividing ability for a wafer mounted on an anisotropic dicing tape 3 in which the spring constant in the X direction and the spring constant in the Y direction are different.

[0086] Here, the results of experiments conducted by the inventors to confirm the effects of the present invention will be described.

[0087] The graph in Fig. 11 shows the expansion rate of the annular region (diameter 350 mm) when no expansion restriction ring is used for the wafer unit 2 in Fig. 23, and the expansion rate of the inner peripheral region when an expansion restriction ring is used, with the diameter of the expansion restriction opening set to 346 mm, 342 mm, and 338 mm. Note that "MD (Machine Direction)" in Fig. 11 is the direction parallel to the feed direction during manufacturing of the dicing tape 3, and is the direction with a small spring constant. Also, "CD (Cross Direction)" is the direction perpendicular to MD, and is the direction with a large spring constant.

[0088] According to the experimental results in Figure 11, the expansion rate of the annular region when the expansion restriction ring was not used was 6.1% in "MD" and 6.0% in "CD". In contrast, as the diameter of the expansion restriction opening was reduced to 346 mm, 342 mm, and 338 mm, the expansion rate of the inner circumference region increased to 6.8%, 7.5%, and 8.4% in "MD", and to 7.2%, 7.5%, and 8.1% in "CD". In other words, it was confirmed that the chip separation ability improved as the diameter of the expansion restriction opening was reduced.

[0089] The graph in Fig. 12 shows the division rate of chips when no expansion restriction ring is used (diameter 350 mm) for the wafer unit 2 in Fig. 23, and the division rate of chips when an expansion restriction ring is used and the diameter of the expansion restriction opening is set to 338 mm. Note that the division rate "with DAF" in Fig. 12 is the division rate of chips 6 when the wafer 1 is attached to the dicing tape 3 via the DAF, and the division rate "without DAF" is the division rate of chips 6 when the wafer 1 is directly attached to the dicing tape 3.

[0090] According to the experimental results in Fig. 12, the division rate of the chip 6 when the expansion restriction ring was not used was 15.0% "with DAF" and 41.0% "without DAF". In contrast, when an expansion restriction ring with an expansion restriction opening diameter of 338 mm was used, the division rate of the chip 6 increased to 61.0% "with DAF" and to 100% "without DAF". In other words, it was confirmed that the division ability of the chip 6 is improved by using the expansion restriction ring, whether "with DAF" or "without DAF".

[0091] From the above experimental results, it was confirmed that, according to the embodiment of the work division devices 10A and 10B, by restricting the expansion of the outer peripheral region 3E by the expansion restricting ring 16 and expanding only the inner peripheral region 3F, the expansion rate is increased compared to the annular region 3B and the tension applied to the wafer 1 can be increased, thereby solving the problem of non-division of the intended division line 5 that occurs when the chip size is small.

[0092] [Workpiece dividing device 10C according to the third embodiment] FIG. 13 is a cross-sectional view of a main part of a work dividing device 10C according to the third embodiment.

[0093] The difference in structure between the work division device 10C in FIG. 13 and the work division device 10A shown in FIG. 1 is that a convex rib portion 34 is provided on the expansion restriction ring 32 of the work division device 10C in FIG.

[0094] In describing the expansion restriction ring 32 in FIG. 13, the same or similar members as those in the expansion restriction ring 16 in FIG. 1 are designated by the same reference numerals and description thereof will be omitted.

[0095] The expansion restriction ring 32 in FIG. 13 includes a frame fixing portion 12 and a convex portion 34 formed to protrude toward the application surface 3G of the dicing tape 3. The convex portion 34 is provided along the peripheral portion of the expansion restriction opening 32A of the expansion restriction ring 32. The tip portion 34A of the convex portion 34 constitutes a tape position restricting portion, and the tip portion 34A is disposed in a position on the same plane as the back surface (tape application surface) 4A of the frame 4 to which the outer periphery of the dicing tape 3 is fixed (applied). In other words, the tip portion 34A of the convex portion 34 constituting the tape position restricting portion is disposed in a position on the same plane as the application surface 3G of the dicing tape 3 when the frame 4 is fixed to the expansion restriction ring 32.

[0096] 13, the tip 34A of the convex portion 34 of the expansion restriction ring 32 is already in contact with the application surface 3G of the dicing tape 3 before the dicing tape 3 is expanded by the expanding ring 14. In other words, the expansion of the outer circumferential region 3E of the dicing tape 3 is restricted by the expansion restriction ring 32 before the dicing tape 3 is expanded by the expanding ring 14.

[0097] 13, the expansion of the inner peripheral region 3F of the dicing tape can be started immediately after the expanding ring 14 comes into contact with the dicing tape 3. Therefore, the work division device 10C can more efficiently solve the problem of non-division of the intended division line that occurs when the chip size is small, compared to the case where the expansion restricting ring 14 of FIG.

[0098] In addition, when the height of the expanding operation end position of the expand ring 14 is the same in the work division device 10A in Fig. 1 and the work division device 10C in Fig. 13, the expansion amount (tension) of the inner region 3F of the dicing tape 3 is greater in the work division device 10C in Fig. 13 than in the work division device 10A in Fig. 1. Therefore, the work division device 10C in Fig. 13 can further solve the problem of non-division of the intended division line that occurs when the chip size is small.

[0099] On the other hand, when the expansion amount of the inner region 3F of the dicing tape 3 at the end of the expansion operation of the expanding ring 14 is based on the dicing device 10A of Fig. 1, in the work division device 10C of Fig. 13, the height of the expansion operation end position of the expanding ring 14 can be lowered by the thickness of the frame 4 compared to the work division device 10A of Fig. 1. As a result, according to the work division device 10C of Fig. 13, a sufficient expansion amount (tension) can be obtained even with a small upward movement amount of the expanding ring 14, so that the problem of non-division of the intended division line that occurs when the chip size is small can be more efficiently solved.

[0100] Specifically, as shown in the enlarged cross-sectional view of the main part of the workpiece dividing device 10C shown in Fig. 14, when the expansion restriction ring 32 is used, the height of the end position of the expanding operation of the expanding ring 14 can be lowered by the thickness of the frame 4 compared to when the expansion restriction ring 14 of Fig. 1 without the convex rib portion 34 is used, and the problem of non-division of the intended dividing line that occurs when the chip size is small can be efficiently solved by that amount. Note that in Fig. 14, the end position of the expanding operation of the expanding ring 14 when the expansion restriction ring 14 without the convex rib portion 32 is used is shown by a two-dot chain line.

[0101] Moreover, according to the workpiece dividing device 10C, the tip portion 34A of the convex rib portion 34 of the expansion restriction ring 32 is surface-treated to have an arithmetic mean roughness (Ra) of 1.6 (μm), for example, similar to the inner edge portion 16B of the expansion restriction ring 14 in Fig. 1. This prevents the tip portion 34A and the annular region 3B from slipping relative to each other due to friction between them.

[0102] [Workpiece dividing device 10D of the fourth embodiment] FIG. 15 is a cross-sectional view of a main part of a work dividing device 10D according to the fourth embodiment.

[0103] The structural difference between the work division device 10D in Figure 15 and the work division device 10C shown in Figure 13 is that the tip portion 38A of the convex portion 38 of the expansion control ring 36 of the work division device 10D is positioned on the side where the expand ring 14 is positioned before the expansion operation, rather than on the same surface as the application surface 3G of the dicing tape 3.

[0104] In describing the expansion restriction ring 36 in FIG. 15, the same or similar members as those in the expansion restriction ring 32 in FIG. 13 are designated by the same reference numerals and description thereof will be omitted.

[0105] 15, the application surface 3G of the dicing tape 3 is already pressed against the tip 38A of the protruding portion 38 of the expansion restriction ring 36 before the dicing tape 3 is expanded by the expanding ring 14. In other words, the expansion of the outer peripheral region 3E of the dicing tape 3 is restricted by the expansion restriction ring 32 before the dicing tape 3 is expanded by the expanding ring 14, and the expansion of the inner peripheral region 3F has already been performed. Therefore, the work division device 10D can more efficiently solve the problem of non-division of the intended division line that occurs when the chip size is small, compared to the work division device C of FIG.

[0106] Furthermore, when the height of the expanding operation end position of the expand ring 14 is the same in the work division device 10D of Fig. 15 and the work division device 10C of Fig. 13, the expansion amount (tension) of the inner region 3F of the dicing tape 3 is greater in the work division device 10D of Fig. 15 than in the work division device 10C of Fig. 13. Therefore, the work division device 10D of Fig. 15 can further solve the problem of non-division of the intended division line that occurs when the chip size is small.

[0107] On the other hand, when the expansion amount of the inner region 3F of the dicing tape 3 at the end of the expansion operation of the expanding ring 14 is based on the dicing device 10C of Fig. 13, the work division device 10D of Fig. 15 can lower the height of the expansion operation end position of the expanding ring 14 by the difference in the protruding length of the convex rib portion 38 relative to the convex rib portion 34, compared to the work division device 10C of Fig. 13. As a result, the work division device 10D of Fig. 15 can more efficiently solve the problem of non-division of the intended division line that occurs when the chip size is small than the work division device 10C of Fig. 13.

[0108] Specifically, as shown in the enlarged cross-sectional view of the main part of the workpiece dividing device 10D shown in Fig. 16, when the expansion restriction ring 36 is used, the height of the expansion end position of the expand ring 14 can be shortened by the difference in the protruding length of the convex rib portion 38 relative to the convex rib portion 34 compared to when the expansion restriction ring 32 of Fig. 13 is used, and the problem of non-division of the planned division line that occurs when the chip size is small can be efficiently solved by that difference. In Fig. 16, the expansion operation end position of the expand ring 14 when the expansion restriction ring 32 having the convex rib portion 32 is used is shown by a two-dot chain line.

[0109] Moreover, according to the work division device 10D, the tip portion 38A of the convex rib portion 38 of the expansion restriction ring 36 is surface-treated to have an arithmetic mean roughness (Ra) of 1.6 (μm), for example, similar to the inner edge portion 16B of the expansion restriction ring 14 in Fig. 1. This prevents the tip portion 38A and the annular region 3B from slipping relative to each other due to friction between them.

[0110] [Workpiece dividing device 10E of the fifth embodiment] FIG. 17 is an enlarged cross-sectional view of a main part of a work dividing device 10E according to the fifth embodiment.

[0111] The workpiece dividing device 10E in Fig. 17 has an expansion restriction ring 40 detachably provided on the frame fixing member 7. In describing the expansion restriction ring 40, the same reference numerals will be used to denote members that are the same as or similar to the expansion restriction ring 32 in Fig. 13.

[0112] 17, a convex ridge portion 34 facing the application surface 3G of the dicing tape 3 is provided along the periphery of the expansion restricting opening 40A of the expansion restricting ring 40. In addition, a tip portion 34A of the convex ridge portion 34 is disposed in a position on the same plane as the application surface 3G of the dicing tape 3 (see FIG. 13).

[0113] 17, the expansion of the inner peripheral region 3F of the dicing tape can be started immediately after the expanding ring 14 comes into contact with the dicing tape 3. Therefore, the work division device 10E can more efficiently solve the problem of non-division of the division line that occurs when the chip size is small, compared to the case where the expansion restricting ring 14 of FIG.

[0114] [Workpiece dividing device 10F according to the sixth embodiment] FIG. 18 is an enlarged cross-sectional view of a main part of a work dividing device 10F according to the sixth embodiment.

[0115] The workpiece dividing device 10F in Fig. 18 has an expansion restriction ring 42 detachably provided on the frame fixing member 7. In describing the expansion restriction ring 42, the same reference numerals will be used to denote members that are the same as or similar to the expansion restriction ring 36 in Fig. 15.

[0116] 18, a convex portion 38 facing the application surface 3G of the dicing tape 3 is provided along the periphery of the expansion restricting opening 42A of the expansion restricting ring 42. In addition, a tip portion 38A of the convex portion 38 is disposed on the side where the expand ring 14 before the expansion operation is disposed.

[0117] As a result, according to the work division device 10F of Figure 18, expansion of the inner peripheral region 3F of the dicing tape begins before the expansion ring 14 comes into contact with the dicing tape 3, so that the problem of non-division of the intended division line that occurs when the chip size is small can be resolved more efficiently than when the expansion control ring 40 of Figure 17, which is equipped with a convex rib portion 34, is used.

[0118] 5, an expandable retaining ring called a sub-ring may be fitted to the frame 4 to maintain the expanded state of the dicing tape 3. This expandable retaining ring is fitted to the frame 4 with the outer circumferential region 3E stretched. The use of the expandable retaining ring has the effect of preventing contact between adjacent divided chips, thereby preventing damage to the chips.

[0119] 13 to 18, the tip portions 34A, 38A of the protruding portions 34, 38 can restrict the expansion of the outer circumferential region 3E, so that the dicing tape 3 in the outer circumferential region 3E does not stretch and the thickness of the dicing tape 3 can be prevented from becoming thin. Therefore, even if the expansion retaining ring is attached to the frame 4 with the outer circumferential region 3E stretched, the outer circumferential region 3E can be prevented from being torn.

[0120] 5, a heating step may be performed in which the dicing tape 3 in the outer peripheral region 3E that has become loose after expansion is thermally shrunk by light heating and tensioned again. By performing this heating step, the dicing tape 3 in the outer peripheral region 3E can be tensioned again, which has the effect of facilitating processing in the step after the dividing step S130.

[0121] 13 to 18, the thickness of the outer circumferential region 3E is not reduced, so that the light absorption rate of the outer circumferential region 3E increases and the efficiency of converting light into heat increases in the thermal shrinkage process of the outer circumferential region 3E by light heating. This allows the outer circumferential region 3E to be thermally shrunk in a short time.

[0122] In the graph of FIG. 19, the expansion rate (%) of the dicing tape 3 is plotted on the vertical axis, and the push-up amount (mm) of the annular region 3B caused by the upward movement of the expand ring 14 is plotted on the horizontal axis.

[0123] 19 also shows that the expansion rate according to the thrust amount differs for each of the expansion restriction rings 16, 18, 32, 36, 40, and 42, as will be described later. Note that the expansion rate caused by the expansion restriction ring 18 is equal to the expansion rate caused by the expansion restriction ring 16, and therefore a description of the expansion rate caused by the expansion restriction ring 18 will be omitted. Similarly, the expansion rate caused by the expansion restriction ring 40 is equal to the expansion rate caused by the expansion restriction ring 32, and the expansion rate caused by the expansion restriction ring 42 is equal to the expansion rate caused by the expansion restriction ring 36, and therefore a description of the expansion rate caused by the expansion restriction rings 40 and 42 will also be omitted.

[0124] Line A in FIG. 19 shows the change in the expansion rate when no expansion restriction ring is used (diameter of expansion restriction opening 16A corresponds to 350 mm). Line B shows the change in the expansion rate when an expansion restriction ring 16 with a diameter of expansion restriction opening 16A of 338 mm is applied. Line C shows the change in the expansion rate when an expansion restriction ring 32 with a diameter of expansion restriction opening 32A of 338 mm is applied. Line D shows the change in the expansion rate when an expansion restriction ring 36 with a diameter of expansion restriction opening 36A of 338 mm is applied. As an example, the protruding length of the convex ridge portion 34 of the expansion restriction ring 32 is set to 1.5 mm, which is equal to the thickness of the frame 4 as described later, and the protruding length of the convex ridge portion 38 of the expansion restriction ring 36 is set to 4.5 mm.

[0125] Fig. 20 is a schematic diagram showing the operation of the expanding ring 14 during the expanding and dividing step. Fig. 20 shows the dimensions of each member for calculating the expansion ratio of the lines A, B, C, and D shown in Fig. 19.

[0126] FIG. 20 shows 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 expansion restricting opening 16A (32A, 36A) of the expansion restricting ring 16 (32, 36) is 338 mm.

[0127] Also, the symbol x in Fig. 20 indicates the amount of pushing up of the annular region 3B due to the upward movement of the expanding ring 14. Furthermore, a roller 44 for reducing frictional force with the dicing tape 3 is disposed on the upper end of the expanding ring 14, and it is shown that the arrangement diameter D3 of the roller 44 is 323.2 mm. The symbol d in Fig. 20 indicates the diameter of the roller 44. Note that the expansion rate (%) of line A was calculated assuming the diameter d of the roller 44 to be 5 mm, and the expansion rates (%) of lines B, C, and D were calculated assuming the diameter d of the roller 44 to be 7 mm.

[0128] The expansion ratios of the expansion restriction rings 16, 32, and 36 will be described below with reference to FIG.

[0129] First, when the expansion restriction ring 16 is applied (see line B), the upward movement of the expand ring 14 pushes up the annular region 3B and makes contact with the expansion restriction ring 16. The expansion rate immediately after this contact is higher than the expansion rate when the expansion restriction ring is not applied (see line A). In other words, when the expansion restriction ring 16 is applied, the expansion rate after the amount of push-up exceeds approximately 5.0 mm is higher than the expansion rate when the expansion restriction ring is not applied.

[0130] Furthermore, when the expansion restriction ring 32 is applied (see line C), the tip 34A of the convex ridge 34 is in advance in contact with the annular region 3B. Therefore, when the expansion restriction ring 32 is applied, the expansion rate immediately after the expand ring 14 comes into contact with the annular region 3B is higher than the expansion rate when the expansion restriction ring 16 is applied (see line B).

[0131] Furthermore, when the expansion restriction ring 36 is applied (see line D), the tip 38 of the convex ridge 38 presses the annular region 3B in advance, so the expansion rate already exceeds 0% before the expand ring 14 comes into contact with the annular region 3B. For this reason, when the expansion restriction ring 36 is applied, the expansion rate immediately after the expand ring 14 comes into contact with the annular region 3B is higher than the expansion rate when the expansion restriction ring 32 is applied (see line C).

[0132] Here, Figure 21 shows a graph showing the change in the rate of increase per unit time (hereinafter referred to as the expansion rate speed (% / sec)) of each expansion rate (%) of lines A, B, C, and D shown in Figure 19.

[0133] The graph in Figure 21 shows the expansion rate speed (% / sec) on the left vertical axis, the thrust speed (mm / sec) of the annular region 3B on the right vertical axis, and the thrust amount (mm) of the annular region 3B due to the upward movement of the expand ring 14 on the horizontal axis.

[0134] 21 shows, as an example, the change in the expansion rate when the push-up speed of the annular region 3B is constant. The higher the expansion rate, the greater the tension generated in the dicing tape 3, and the greater the force dividing the wafer into chips.

[0135] Line E in Fig. 21 shows the change in thrust speed when the thrust amount is from 0.00 mm to 20.00 mm. In other words, line E shows the upward movement speed of the expanding ring 14. According to line E, the expanding ring 14 moves upward at a constant speed (200 mm / sec) within the range of 0.00 mm to approximately 18.50 mm, and thereafter, the expanding ring 14 moves upward while decelerating to 20.00 mm.

[0136] Line F in FIG. 21 shows the change in expansion rate velocity corresponding to the expansion rate of line A in FIG. 19 without the application of an expansion restraining ring.

[0137] Line G in FIG. 21 shows the change in the expansion rate speed corresponding to the expansion rate of line B in FIG. 19 when an expansion limiting ring 16 having an expansion limiting opening 16A with a diameter of 338 mm is applied.

[0138] Line H in Fig. 21 shows the change in the expansion rate speed corresponding to the expansion rate of lines C and D in Fig. 19 when the expansion restriction rings 32 and 36 having expansion restriction openings 32A and 36A with diameters of 338 mm are applied. When the expansion restriction ring 36 is applied, the annular region 3B is expanded in advance by the convex rib portion 38 before expansion by the expand ring 14, but the expansion rate speed is the same as when the expansion restriction ring 32 is applied. For this reason, the change in the expansion rate speed when the expansion restriction rings 32 and 36 are applied is shown by the same line H.

[0139] According to the expansion rate speeds shown by lines F, G, and H in Figure 21, each increases according to the thrust amount, reaches a maximum (maximum expansion rate speed) when the thrust amount reaches approximately 18.50 mm, and then decreases.

[0140] Here, when the expansion restriction ring 16 is applied (see line G), the upward movement of the expand ring 14 pushes up the annular region 3B and makes contact with the expansion restriction ring 16. The expansion rate immediately after the contact becomes higher than the expansion rate when the expansion restriction ring is not applied (see line F). Specifically, the expansion rate becomes higher when the amount of push-up exceeds about 4.00 mm than when the expansion restriction ring is not applied, and the maximum expansion rate increases compared to when the expansion restriction ring is not applied (increases from about 95% / sec to about 115% / sec).

[0141] Therefore, by applying the expansion control ring 16, the amount of expansion of the dicing tape 3 increases (see Figure 19) compared to when the expansion control ring is not applied, and the maximum expansion rate speed also increases, thereby increasing the tension generated in the dicing tape 3, thereby eliminating the problem of non-division of the intended division line that occurs when the chip size is small.

[0142] Furthermore, when the expansion restriction rings 32, 36 are applied (see line H), when the expand ring 14 contacts the annular region 3B, the expansion rate immediately after the contact becomes higher than the expansion rate when the expansion restriction ring 16 is applied (see line G). Furthermore, by applying the expansion restriction rings 32, 36, the maximum expansion rate increases (from about 95% / sec to about 115% / sec) compared to when the expansion restriction rings are not applied.

[0143] Therefore, by applying the expansion restriction rings 32, 36, the amount of expansion of the dicing tape 3 is increased (see Figure 19) compared to when the expansion restriction rings are not applied, and the maximum expansion rate speed is also increased, thereby increasing the tension generated in the dicing tape 3, thereby solving the previously mentioned problem of undivided tape.

[0144] As described above, by applying the expansion restriction rings 16, 18, 32, 36, 40, 42 of the embodiment, the problem of non-division along the intended dividing lines, which occurs when the chip size is small, can be solved. [Explanation of symbols]

[0145] 1...wafer, 2...wafer unit, 3...dicing tape, 3A...central region, 3B...annular region, 3C...fixed region, 3D...contact portion, 3E...outer periphery region, 3F...inner periphery region, 3FA...inner periphery region, 3FB...inner periphery region, 4...frame, 4A...back surface, 5...planned division line, 6...chip, 7...frame fixing member, 8...expanding ring, 10A...work division device, 10B...work division device, 10C...work division device, 10D...work division device, 10E...work division device, 10F...work division device, 12...frame fixing portion, 14...expanding ring, 14A...expansion opening, 16...expansion restriction ring, 16A...expansion restriction opening, 16B...inner edge, 17...expansion restriction portion, 18...expansion restriction ring, 18A...expansion restriction opening, 18B...inner edge, 20...expansion restriction ring, 20A...expansion restriction opening, 22...wafer, 24...chip, 26...expansion restriction ring, 26A...expansion restriction opening, 28...wafer, 30...chip, 32...expansion restriction ring, 32A...expansion restriction opening, 34...ridge portion, 34A...tip portion, 36...expansion restriction ring, 36A...expansion restriction opening, 38...ridge portion, 38A...tip portion, 40...expansion restriction ring, 40A...expansion restriction opening, 42...expansion restriction ring, 42A...expansion restriction opening, 44...roller

Claims

1. A workpiece dividing device in which an outer periphery of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than an outer diameter of a workpiece, and the workpiece attached to the dicing tape is divided into individual chips along a planned division line, an expand ring that is disposed on the back surface side of the dicing tape opposite to the attachment surface of the workpiece, is formed in a ring shape that is smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the workpiece, and presses the back surface of the dicing tape to expand the dicing tape; an expansion restriction ring that is arranged on the same side of the dicing tape as the application surface of the work, that is formed in a ring shape having an opening that is smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the expanding ring, and that contacts the dicing tape when the dicing tape is expanded by the expanding ring; Equipped with A work division device, wherein the width dimension of the area of ​​the dicing tape that is outside the area where the work is affixed and inside the abutment position of the expansion restriction ring is set according to the number of the planned division lines or the size of the chip.

2. 2. The workpiece dividing device according to claim 1, wherein the expansion restriction ring has a surface treated at a position where the expansion restriction ring abuts against the dicing tape to prevent the dicing tape from slipping.

3. A workpiece dividing device in which an outer periphery of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than an outer diameter of a workpiece, and the workpiece attached to the dicing tape is divided into individual chips along a planned division line, an expand ring that is disposed on the back surface side of the dicing tape opposite to the attachment surface of the workpiece, is formed in a ring shape that is smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the workpiece, and presses the back surface of the dicing tape to expand the dicing tape; an expansion restriction ring that is arranged on the same side of the dicing tape as the application surface of the work, that is formed in a ring shape having an opening that is smaller than the inner diameter of the ring-shaped frame and larger than the outer diameter of the expanding ring, and that contacts the dicing tape when the dicing tape is expanded by the expanding ring; Equipped with A workpiece dividing device, wherein the expansion restriction ring has a surface treatment applied to the contact position of the dicing tape to prevent the dicing tape from slipping.

4. the expansion restriction ring has a tape position restriction portion that comes into contact with the dicing tape when the dicing tape is expanded by the expanding ring, The work division device according to any one of claims 1 to 3, wherein the tape position regulating unit is arranged on the same plane as a tape application surface of the ring-shaped frame to which the dicing tape is applied, or on a side of the same plane on which the expand ring is disposed.

5. the expansion restriction ring includes a frame fixing portion fixed to the ring-shaped frame, and a protruding portion protruding toward the dicing tape along a peripheral portion of the opening of the expansion restriction ring, The work division device according to claim 4 , wherein the tape position regulating portion is formed by a tip end of the protruding ridge portion.

6. The work division device according to any one of claims 1 to 5, wherein the expansion restriction ring is provided with a frame fixing portion arranged on the same side as the application surface of the work on the dicing tape, the frame fixing portion abutting against the ring-shaped frame to fix the ring-shaped frame.

7. The work division device according to any one of claims 1 to 5, wherein the expansion regulating ring is a frame fixing member arranged on the same side of the dicing tape as the application surface of the work, and is removably fixed to a frame fixing member that fixes the ring-shaped frame via the expansion regulating ring.

8. 8. The workpiece dividing device according to claim 1, wherein the expansion restriction ring is chamfered at a position where the expansion restriction ring abuts against the dicing tape to prevent the dicing tape from being torn.

9. A workpiece dividing method in which an outer periphery of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than an outer diameter of a workpiece, and the workpiece attached to the dicing tape is divided into individual chips along a planned division line, comprising: an expanding step of pressing the dicing tape to expand the dicing tape, thereby generating tension in the dicing tape; an expansion restricting step of restricting expansion of an outer peripheral region of the dicing tape located on the outer peripheral side when the dicing tape is expanded; a dividing step of dividing the workpiece into individual chips by continuing to expand the dicing tape excluding the outer circumferential region; The expansion restriction step includes contacting an expansion restriction ring having an opening smaller than an inner diameter of the ring-shaped frame and larger than an outer diameter of the workpiece with the dicing tape, A work division method, in which a width dimension of a region of the dicing tape that is outside the region where the work is affixed and inside the abutment position of the expansion restriction ring is set according to the number of the planned division lines or the size of the chip.

10. 10. The workpiece dividing method according to claim 9, wherein the expansion restriction ring has a surface treated at a position where the expansion restriction ring abuts against the dicing tape to prevent the dicing tape from slipping.

11. A workpiece dividing method in which an outer periphery of a dicing tape is fixed to a ring-shaped frame having an inner diameter larger than an outer diameter of a workpiece, and the workpiece attached to the dicing tape is divided into individual chips along a planned division line, comprising: an expanding step of pressing the dicing tape to expand the dicing tape, thereby generating tension in the dicing tape; an expansion restricting step of restricting expansion of an outer peripheral region of the dicing tape located on the outer peripheral side when the dicing tape is expanded; a dividing step of dividing the workpiece into individual chips by continuing to expand the dicing tape excluding the outer circumferential region; The expansion restriction step includes contacting an expansion restriction ring having an opening smaller than an inner diameter of the ring-shaped frame and larger than an outer diameter of the workpiece with the dicing tape, A workpiece dividing method, wherein the expansion regulating ring has a surface treatment applied to the contact position of the dicing tape to prevent the dicing tape from slipping.

12. The work division method according to any one of claims 9 to 11, wherein the expansion regulating ring is a frame fixing member arranged on the same side of the dicing tape as the application surface of the work, and is removably fixed to a frame fixing member that fixes the ring-shaped frame via the expansion regulating ring.

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