Workpiece dividing device and workpiece dividing method

Abstract

To provide a work division device and a work division method, capable of effectively removing a slacking due to a plastic deformation of a dicing tape generated after expanding.SOLUTION: A work division device comprises: an expansion step of expanding a dicing tape 3; a heating step of thermally contracting the dicing tape 3; and an expansion state holding step of holding an expansion state of the dicing tape 3 to be thermally contracted.SELECTED DRAWING: Figure 7

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 workpiece dividing device is known that divides a semiconductor wafer (hereinafter referred to as wafer), which has a division line formed therein in advance by half-cutting with a dicing blade or forming a modified region by laser irradiation, into individual chips along the division line (see Patent Document 1, etc.). The workpiece dividing device of Patent Document 1 divides the wafer into individual chips by expanding the dicing tape to which the wafer is attached with an expand ring.

[0003] Furthermore, in the field of workpiece dividing devices, it is also required to prevent deterioration in chip quality due to contact between chips after division by maintaining the expanded state of the dicing tape expanded by the expanding ring.

[0004] In order to satisfy this requirement, the workpiece dividing device of Patent Document 1 is provided with a sub-ring. This sub-ring has a function of holding the dicing tape expanded by the expanding ring in an expanded state, and is configured to have a diameter larger than the inner diameter of the frame. The sub-ring is inserted between the outer periphery of the dicing tape and the surface of the frame immediately after it is raised from the back side of the dicing tape toward the dicing tape and passes through the frame. This makes it possible to hold the expanded state of the dicing tape even after the expansion of the dicing tape by the expanding ring is completed. By holding the expanded state of the dicing tape in this way, it is possible to prevent the dicing tape from loosening, thereby preventing the quality degradation of the chips caused by contact between the chips. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-51368 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional work division device, it was difficult to expand the dicing tape without causing any plastic deformation. In particular, since a large tension is applied to the dicing tape as the chip size becomes smaller, the dicing tape to which a wafer with a small chip size is attached tends to be easily plastically deformed as a whole when expanded.

[0007] In Patent Document 1, a sub-ring is used to remove slack caused by plastic deformation of the dicing tape after expansion. However, there is a problem in that it is difficult for the sub-ring to fully remove slack that occurs throughout the entire dicing tape.

[0008] The present invention has been made in consideration of such problems, and has an object to provide a work division device and a work division method that can effectively eliminate slack caused by plastic deformation of the dicing tape after expansion. [Means for solving the problem]

[0009] In order to achieve the object of the present invention, the work division device of the present invention is a work division device that divides a work attached to a dicing tape and mounted on a frame into individual chips along a planned division line, and is equipped with an expanding ring that applies tension to the dicing tape to expand the dicing tape, a heating unit that applies heat to the entire dicing tape expanded by the expanding ring to thermally shrink the entire dicing tape, and an expansion retaining ring that expands the dicing tape thermally shrunk by the heating unit and maintains the expanded state of the dicing tape.

[0010] In one aspect of the present invention, the heating section preferably includes a heating member that radiates radiant heat, and a heat reflecting member that reflects the radiant heat radiated from the heating member toward the dicing tape.

[0011] In one aspect of the present invention, the heating member is preferably a halogen lamp.

[0012] In order to achieve the object of the present invention, the work dividing method of the present invention is a work dividing method for dividing a work attached to a dicing tape and mounted on a frame into individual chips along planned division lines, and includes an expansion step in which tension is applied to the dicing tape to expand the dicing tape, a heating step in which heat is applied to the entire dicing tape expanded in the expansion step to thermally shrink the entire dicing tape, and an expanded state maintaining step in which the dicing tape thermally shrunk in the heating step is expanded and the expanded state of the dicing tape is maintained.

[0013] In one embodiment of the present invention, the heating step preferably applies radiant heat to the entire dicing tape. Effect of the Invention

[0014] According to the present invention, slack caused by plastic deformation of the dicing tape after expansion can be effectively removed. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a cross-sectional view showing a structure of a workpiece dividing device according to an embodiment. [Diagram 2] An enlarged perspective view of the main part showing the structure of the expansion part [Diagram 3] FIG. 1 is a longitudinal sectional view of a main portion of a wafer unit showing the shape of an annular region during expansion. [Figure 4] A vertical cross-sectional view showing the expansion state of the dicing tape by the expansion retaining ring. [Diagram 5] FIG. 2 is an enlarged perspective view of a main part showing the configuration of a heating unit of the workpiece dividing device shown in FIG. [Figure 6] Block diagram showing the control system of the workpiece separation device [Figure 7] 1 is a flowchart showing an example of a wafer dividing method. [Figure 8] Operational diagram of the workpiece dividing device [Figure 9] Operational diagram of the workpiece dividing device [Figure 10] Operational diagram of the workpiece dividing device [Figure 11] An explanatory diagram of a wafer unit with a wafer attached [Figure 12] Vertical cross-sectional view of the wafer unit [Figure 13] Operation diagram of the workpiece dividing device [Figure 14] A longitudinal sectional view of a wafer unit into which wafers are separated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] 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.

[0017] Before describing the work dividing device 10 (see FIG. 1) according to the embodiment, a wafer to be divided by the work dividing device 10 of the embodiment will be described.

[0018] 11A and 11B are explanatory diagrams of a wafer unit 2 to which a disk-shaped wafer 1 is attached, with FIG. 11A being a perspective view of the wafer unit 2 and FIG.

[0019] The wafer 1 is attached to the center of a dicing tape 3 having an adhesive layer formed on one side, and the outer periphery of the dicing tape 3 is fixed to a rigid metal ring-shaped frame 4.

[0020] The thickness of the wafer 1 is, for example, about 50 μm, and the thickness of the dicing tape 3 is, for example, about 100 μm. The dicing tape 3 may be, for example, a PVC (polyvinyl chloride) tape. The wafer 1 may be attached to the dicing tape 3 via a film-like adhesive such as DAF (Die Attach Film). The film-like adhesive may be, for example, a PO (polyolefin) type.

[0021] In the workpiece dividing device 10 shown in Fig. 1, the upper surface 4A of the frame 4 of the wafer unit 2 is detachably fixed to the lower surface 7A of the fixing part 7. After that, the expand ring 16 is moved upward from below the wafer unit 2, and the dicing tape 3 is pressed and radially expanded by this expand ring 16. The tension of the dicing tape 3 generated at this time is applied to the division lines 5 of the wafer 1 (see Fig. 11), thereby dividing the wafer 1 into individual chips 6.

[0022] 11(B), in the dicing tape 3, a circular area in plan view to which the wafer 1 is attached is referred to as the central area 3A, a doughnut-shaped area in plan view provided between the outer edge of the central area 3A (the outer edge of the wafer 1) and the inner edge of the frame 4 is referred to as the annular area 3B, and a doughnut-shaped area in plan view 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 by the expand ring 16.

[0023] It is known that in the workpiece dividing device 10, 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 into individual chips 6, must be higher as the number of dividing lines 5 increases. Regarding the number of dividing lines 5, for example, as in the wafer 1 in Fig. 12, when the wafer 1 has a diameter D1 of 300 mm and a chip size of 5 mm, about 120 dividing lines 5 (60 in each of the X and Y directions) are formed, and when the chip size is 1 mm, about 600 dividing lines 5 are formed. Therefore, the tension that must be generated in the annular region 3B must be higher when the chip size is 1 mm than when it is 5 mm.

[0024] The inner diameter D2 (diameter of the inner edge of the frame) of the frame 4 on which the wafer 1 with a diameter D1 of 300 mm is mounted is set to 350 mm according to the SEMI standard (G74-0699 Specifications for Tape Frames for 300 mm Wafers). According to this standard, an annular region 3B with a width dimension a of 25 mm is present between the outer edge of the wafer 1 and the inner edge of the frame 4. The fixing part 7 for fixing the frame 4 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 16, as shown in FIG. 11(B).

[0025] Here, the force dividing the wafer 1 generated by the rising movement of the expand ring 16 is divided into three forces: (i) a force dividing the entire area of ​​the annular region 3B, (ii) a force dividing the wafer 1 into chips 6, and (iii) a force dividing the dicing tape 3 between adjacent chips 6.

[0026] As shown in the operation diagram of the workpiece dividing device in Figures 13(A) to (E), when the expand ring 16 comes into contact with the annular region 3B of the dicing tape 3 and the dicing tape 3 starts to expand due to the upward movement of the expand ring 16 (Figure 13(A)), the annular region 3B, which has the lowest spring constant, starts to expand first (Figure 13(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 13(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 6 proceed simultaneously (Figures 13(D) to (E)).

[0027] Here, for example, in the case of a wafer 1 having a diameter D1 of 300 mm, if the chip size 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, in recent years, as the circuit pattern formed on the wafer 1 becomes finer, chips with smaller chip sizes of 1 mm or less have also appeared. In this case, the force required to divide the wafer 1 increases due to the 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 is required. Then, as shown in the vertical cross-sectional view of the wafer unit 2 in FIG. 14, a problem occurs in that even after the expansion operation by the expand ring 16 is completed, some of the division lines 5 formed on the wafer 1 remain undivided.

[0028] 12, the number of division lines 5 parallel to the X direction and the number of division lines 5 parallel to the Y direction are 300, and the chip size is 1 mm. A work dividing device and a work dividing method that can effectively remove slack caused by plastic deformation of the dicing tape 3 after expansion while solving the above-mentioned problem of non-division in such a wafer 1 will be described.

[0029] Fig. 1 is a cross-sectional view showing the structure of a work division device 10 according to an embodiment. The work division device 10 includes an expansion section 12 and a heating section 14. Fig. 2 is an enlarged perspective view of a main part showing the structure of the expansion section 12.

[0030] 2, the expansion section 12 includes a fixing section 7 that fixes the frame 4, an expanding ring 16 that expands the dicing tape 3 by pressing the annular region 3B of the dicing tape 3 from below to above, an expansion restricting ring 17 that abuts against the annular region 3B of the dicing tape 3 from above, and an expansion retaining ring (also called a sub-ring) 18 that retains the expanded state of the dicing tape 3 expanded by the expanding ring 16. The fixing section 7, the expanding ring 16, the expansion restricting ring 17, and the expansion retaining ring 18 are disposed in a working chamber 20 of the expansion section 12 (see FIG. 1).

[0031] The fixing part 7 is disposed on the same side of the dicing tape 3 as the surface to which the wafer 1 is attached, and the upper surface 4A of the frame 4 is detachably fixed to its lower surface 7A. The fixing part 7 is shaped like a ring having an opening 7B with a diameter D3 (see FIG. 2) of, for example, 361 mm, which is larger than the inner diameter D2 (350 mm: see FIG. 12) of the frame 4.

[0032] The expand ring 16 is disposed on the back surface side of the dicing tape 3 opposite to the surface to which the wafer 1 is attached, and has an expansion opening 16A that is smaller than the inner diameter D2 (350 mm: see FIG. 12) of the frame 4 and larger than the outer diameter D1 (300 mm: see FIG. 12) of the wafer 1. The expand ring 16 is disposed so as to be movable in a direction approaching the dicing tape 3 relatively. Specifically, the expand ring 16 is disposed so as to be movable in the vertical direction between an expansion position (position shown by a two-dot chain line in FIG. 1) where the expand ring 16 presses the back surface of the annular region 3B of the dicing tape 3 upward to expand the annular region 3B, and a retreat position (position shown by a solid line in FIG. 1) where the expand ring 16 is retreated downward from the annular region 3B.

[0033] The workpiece dividing device 10 is provided with an expand ring moving mechanism 22 that moves the expand ring 16 up and down between an expanded position and a retracted position. A feed screw device is illustrated as an example of the expand ring moving mechanism 22, but an actuator such as an air cylinder device can be used instead. When the expand ring 16 located at the retracted position is moved toward the expanded position by the expand ring moving mechanism 22, the expand ring 16 is moved upward in the direction of arrow B toward the annular region 3B. As a result, the back surface of the annular region 3B is pressed by the expand ring 16 and radially expanded.

[0034] The expansion restriction ring 17 is disposed on the same side of the dicing tape 3 as the attachment surface of the wafer 1, and has an expansion restriction opening 17B that is smaller than the inner diameter D2 (350 mm: see FIG. 12) of the frame 4 and larger than the outer diameter of the expand ring 16. As an example, the diameter D4 (see FIG. 1) of the expansion restriction opening 17B is 338 mm.

[0035] The expansion restriction ring 17 is arranged to be freely movable up and down between a restriction position (position shown by a dotted line in Figure 1) where its lower edge portion 17A abuts against the surface of the annular region 3B, and a retracted position (position shown by a solid line in Figure 1) retracted upward from the restriction position.

[0036] The restricting position is a position where the expansion restricting ring 17 restricts the expansion of the outer circumferential region 3E, and in FIG. 1, the lower edge 17A of the expansion restricting ring 17 is set to a position located on the same plane as the lower surface 4B of the frame 4. The restricting position is not limited to that position, and may be any position that can restrict the expansion of the outer circumferential region 3E. The outer circumferential region 3E is a region of the annular region 3B that is located on the outer circumferential side of the abutment portion 3D (see FIG. 3) that abuts against the lower edge 17A of the expansion restricting ring 17. The region of the annular region 3B excluding the outer circumferential region 3E is the inner circumferential region 3F, and this inner circumferential region 3F is the region expanded by the expand ring 16.

[0037] 1, the workpiece dividing device 10 is provided with an expansion restriction ring moving mechanism 23 that moves the expansion restriction ring 17 up and down between the restriction position and the retracted position. An air cylinder device is shown as an example of the expansion restriction ring moving mechanism 23, but an actuator such as a feed screw device can also be used instead.

[0038] FIG. 3 is an enlarged cross-sectional view of a main part of the wafer unit 2, showing the shape of the annular region 3B in the middle of being expanded by the expand ring 16. As shown in FIG.

[0039] 3, when the annular region 3B is expanded by the expand ring 16, the expansion restriction ring 17 is positioned at a restriction position prior to the expansion operation by the expand ring 16. That is, the expansion of the outer circumferential region 3E of the dicing tape 3 is restricted in advance by the expansion restriction ring 17. Therefore, according to the work division device 10 of the embodiment, the expansion of the inner circumferential region 3F starts immediately after the expand ring 16 comes into contact with the annular region 3B.

[0040] In the embodiment, as shown in Figure 1, the diameter D4 of the expansion restriction opening 17B is set to 338 mm, so that the width dimension b of the outer peripheral region 3E whose expansion is restricted by the expansion restriction ring 17 is set to 6 mm, and the width dimension c of the inner peripheral region 3F whose expansion is restricted by the expand ring 16 is set to 19 mm.

[0041] Here, within the annular region 3B, the inner peripheral region 3F expanded by the expand ring 16 is the region that substantially contributes to the division of the wafer 1. As the width dimension c of this inner peripheral region 3F is reduced, the spring constant of the inner peripheral region 3F increases, and therefore the tension applied from the inner peripheral region 3F to the wafer 1 increases. For this reason, the diameter D4 of the expansion restricting opening 17B, which determines the width dimension c of the inner peripheral region 3F, is set according to the division conditions defined by the number of planned division lines 5 and the like.

[0042] On the other hand, the expansion retaining ring 18 is disposed on the back surface side of the dicing tape 3 opposite to the surface to which the wafer 1 is attached. As shown in Fig. 4, the expansion retaining ring 18 has a main body ring 24 having an outer diameter D5 smaller than the inner diameter D2 (350 mm) of the frame 4 and an inner diameter D6 larger than the outer diameter of the expand ring 16, and an elastically deformable ring-shaped fitting portion 26 attached to the outer periphery of the main body ring 24 and having an outer diameter D7 (351.3 mm) larger than the inner diameter D2 (350 mm) of the frame 4. Fig. 4 is a vertical cross-sectional view in which the expanded state of the dicing tape 3 is maintained by the expansion retaining ring 18.

[0043] Before expansion and retention, the expansion retaining ring 18 is disposed in a standby position shown by a solid line in Fig. 1, and during expansion and retention, it is moved upward from the standby position by an expansion retaining ring moving mechanism 28. A feed screw device is shown as an example of the expansion retaining ring moving mechanism 28, but an actuator such as an air cylinder device can be used instead.

[0044] When the expansion retaining ring 18 is raised by the expansion retaining ring movement mechanism 28, the fitting portion 26 comes into contact with the lower surface of the frame 4. Thereafter, as the expansion retaining ring 18 continues to move upward, the fitting portion 26 is pushed against the inner circumferential surface of the frame 4 and rises while elastically deforming. Then, the rise of the expansion retaining ring 18 is stopped at a position where the fitting portion 26 has passed the inner circumferential surface of the frame 4. As a result, the fitting portion 26 is fitted into the upper surface 4A of the frame 4 at the fitting position shown in FIG.

[0045] As will be described later, in the embodiment of the work dividing device 10, when the dividing process (S140: see Figure 7) using the expanding ring 16 is completed, a heating process (S150: see Figure 7) of the dicing tape 3 is performed by the heating section 14, and then an expanded state maintaining process (S160: see Figure 7) is performed by the expansion retaining ring 18.

[0046] Returning to FIG. 1, the heating unit 14 will be described.

[0047] The heating unit 14 includes a heating chamber 30 for heating the dicing tape 3 that has been plastically deformed by the expanding action of the expand ring 16 .

[0048] The heating chamber 30 is arranged in parallel to the working chamber 20 via a heat insulating wall 32. The heating chamber 30 is also connected to the working chamber 20 via an opening 36 that is opened and closed by a door 34. Therefore, the wafer unit 2 divided into individual chips 6 by the expansion portion 12 is carried from the working chamber 20 to the heating chamber 30 through the opening 36 by a conveying device (not shown) without the expanded state of the dicing tape 3 being held by the expansion holding ring 18. Then, the frame 4 of the wafer unit 2 carried into the heating chamber 30 is placed on the ring-shaped table 38 of the heating chamber 30 by the conveying device described above. In the workpiece dividing device 10 of the embodiment, since the heating chamber 30 is arranged in parallel to the working chamber 20, the dicing tape 3 expanded in the working chamber 20 can be efficiently transported to the heating chamber 30 and heated.

[0049] Below the table 38 in the heating chamber 30, a plurality of radiant heat emitting members 40 are arranged for heating the entire surface of the dicing tape 3 by radiant heat.

[0050] Here, the heating means for applying heat to the dicing tape 3 will be explained. In addition to radiant heat, the heating means may be means that utilize heat conduction (contact) or heat transfer (convection).

[0051] However, when heat conduction is used as the heating means, since the dicing tape 3, which is the object to be heated, is loose and has an irregular shape, it is difficult to contact the entire dicing tape 3, and therefore it is difficult to uniformly heat the entire dicing tape 3. Also, when heat transfer is used as the heating means, the entire dicing tape 3 can be uniformly heated, but it is difficult to adopt this method because there is a risk that minute dust particles present in the air will adhere to the wafer 1 and contaminate the wafer 1.

[0052] Therefore, in the workpiece dividing device 10 of the embodiment, a radiant heat emitting member 40 that radiates radiant heat is adopted as a preferred form of the heating means. The heating method using radiant heat can solve the above-mentioned problems of heat conduction and heat transfer, and has the advantage of being able to heat only the area irradiated with infrared light, thereby suppressing unnecessary temperature rise.

[0053] Fig. 5 is an enlarged perspective view showing the main configuration of the heating unit 14 shown in Fig. 1. As shown in Fig. 5, the radiant heat emitting member 40 has a halogen lamp 42. A total of multiple halogen lamps 42 (five in Fig. 5) are provided, and these halogen lamps 42 are disposed at equal intervals on the same horizontal plane directly below the dicing tape 3 and are disposed so that their axial directions are parallel to each other.

[0054] It is possible to heat the entire dicing tape 3 using only the halogen lamps 42, but the illuminance may differ between the portion of the dicing tape 3 directly above the lamps where the infrared light from the halogen lamps 42 is directly irradiated and the portion directly above between the lamps where there are no halogen lamps 42. In such a case, temperature unevenness occurs in the dicing tape 3, making it difficult to heat the entire dicing tape 3 uniformly.

[0055] Therefore, in the heating unit 14 of the embodiment, a reflector 44, which is an example of the heat reflecting member of the present invention, is disposed adjacent to the lower side of the halogen lamp 42, and the infrared light emitted downward and to the sides from the halogen lamp 42 is reflected by the reflector 44 and irradiated also to the portion directly above between the lamps. As a result, according to the heating unit 14 of the embodiment, the entire surface of the dicing tape 3 can be heated more uniformly, and therefore the entire dicing tape 3 can be thermally shrunk more uniformly.

[0056] The reflector 44 of the embodiment has a mountain-shaped bottom 44A located below the halogen lamp 42, and a pair of walls 44B, 44B arranged on both sides of the bottom 44A toward the dicing tape 3 and inclined toward the outside of the surface of the dicing tape 3. The reflector 44 having such a shape can efficiently reflect the infrared light from the halogen lamp 42 toward the part directly above the lamps. This allows the entire surface of the dicing tape 3 to be heated more uniformly, so that the entire dicing tape 3 can be thermally shrunk more uniformly. The reflector 44 is not limited to the above shape. That is, the reflector 44 may have a shape that can efficiently reflect the infrared light from the halogen lamp 42 toward the part directly above the lamps, for example, a reflector with a circular arc-shaped vertical cross section that is convex downward.

[0057] Fig. 6 is a functional block diagram of the control unit 48 of the work division device 10. The control unit 48 shown in Fig. 6 has each arithmetic processing circuit including a CPU (central processing unit) and a storage medium such as a memory, and controls the overall operation of the work division device 10 including the expand ring moving mechanism 22, the expansion restricting ring moving mechanism 23, and the expansion retaining ring moving mechanism 28 described above. In addition to the expand ring moving mechanism 22, the expansion restricting ring moving mechanism 23, and the expansion retaining ring moving mechanism 28, a halogen lamp power supply 46 and a radiation thermometer 50 are connected to this control unit 48.

[0058] Under the control of the control unit 48, the halogen lamp power supply 46 supplies power to the halogen lamp 42 and controls the voltage of the power supplied to the halogen lamp 42. The halogen lamp 42 receives power supply from the halogen lamp power supply 46 and turns on to emit infrared light. The amount of infrared light emitted from the halogen lamp 42 is controlled by the magnitude of the voltage applied to the halogen lamp 42 from the halogen lamp power supply 46. In other words, by changing the voltage applied to the halogen lamp 42 from the halogen lamp power supply 46, the temperature to which the dicing tape 3 is heated by the halogen lamp 42 is changed.

[0059] The radiation thermometer 50 is installed in the heating chamber 30 shown in FIG. 1 and measures the temperature of the dicing tape 3. In the embodiment, the radiation thermometer 50 is arranged at a position in the heating chamber 30 where the temperature of the annular region 3B of the dicing tape 3 can be measured, but the arrangement position is not limited thereto. For example, the radiation thermometer 50 may be arranged below the dicing tape 3 in the heating chamber 30 to measure the temperature of the central region 3A. The radiation thermometer 50 outputs the temperature measurement result of the dicing tape 3 to the control unit 48.

[0060] The control unit 48 functions as a voltage control unit 48a by executing a control program (not shown) stored in a memory or the like. When power is being supplied from the halogen lamp power supply 46 to the halogen lamp 42, the voltage control unit 48a controls the magnitude of the voltage applied to the halogen lamp 42 by the halogen lamp power supply 46. Specifically, the power supply control unit 48a controls the magnitude of the voltage applied to the halogen lamp 42 based on the temperature measurement result of the dicing tape 3 input from the radiation thermometer 50 so that the temperature of the dicing tape 3 does not exceed a predetermined upper limit temperature. This adjusts the amount of infrared light emitted from the halogen lamp 42 so that the temperature of the dicing tape 3 does not exceed the upper limit temperature. The upper limit temperature is set based on the material of the base material of the dicing tape 3.

[0061] Next, the workpiece dividing method of the embodiment will be described in accordance with the flowchart in FIG. 7, and the operation explanatory diagrams of the workpiece dividing device 10 shown in FIGS. 8(A)-(D), 9(A)-(B), and 10(A)-(E).

[0062] First, in the arrangement step (S100) of FIG. 7, as shown in FIG. 8(A), the expand ring 16 and the expansion restriction ring 17 are arranged in their respective retreated positions, and the expansion retaining ring 18 is arranged in its standby position.

[0063] Next, in the fixing step (S110) of FIG. 7, the frame 4 of the wafer unit 2 is fixed to the fixing portion 7 as shown in FIG. 8(B).

[0064] Next, in the expansion restricting step (S120) of FIG. 7, as shown in FIG. 8C, the expansion restricting ring 17 is moved from the retreated position to the restricting position, and the lower edge portion 17A of the expansion restricting ring 17 is brought into contact with the surface of the annular region 3B.

[0065] Next, in the expansion start step (S130) of FIG. 7, as shown in FIG. 8(D), the expand ring 16 is moved upward from the retracted position of FIG. 7(A) toward the expanded position to start expanding the annular region 3B.

[0066] In this expansion start step (S130), the lower edge 17A of the expansion restriction ring 17 is in advance abutted against the surface of the annular region 3B to restrict the expansion of the outer circumferential region 3E, so that the inner circumferential region 3F (see FIG. 1) is expanded by the expand ring 16. Note that the expansion restriction step (S120) described above is a step that is performed together with the expansion step from the expansion start step (S130) to the end of the division step (S140) described below. In other words, the expansion step of the present invention refers to the step from the expansion start step (S130) to the end of the division step (S140).

[0067] Next, in the division step (S140) of Fig. 7, as shown in Fig. 9(A), the expansion ring 16 moves upward to continue expanding the inner peripheral region 3F (see Fig. 3), during which the wafer 1 is sequentially divided into individual chips 6. Thereafter, as shown in Fig. 9(B), when the expand ring 16 reaches the expanded position, the upward movement of the expand ring 16 is stopped. At this point, the expansion step described above is completed.

[0068] In such an expansion process, only the inner peripheral region 3F is expanded by the expand ring 16 while the expansion of the outer peripheral region 3E is restricted by the expansion restriction ring 17. That is, the tension generated in the inner peripheral region 3F is applied to the wafer 1.

[0069] Specifically, in the expansion step, by using the expansion restriction ring 17 with the expansion restriction opening 17B having a diameter D4 (see FIG. 1) of 338 mm, the length of the area contributing to the division of the wafer 1 is reduced from 25 mm (width dimension a of the annular region 3B: see FIG. 12) to 19 mm (width dimension c of the inner peripheral region 3F: see FIG. 1). As a result, the spring constant of the inner peripheral region 3F increases, and tension corresponding to the increased spring constant is applied to the wafer 1.

[0070] Therefore, according to the workpiece dividing method of the embodiment, since the expansion restriction step (S120) using the expansion restriction ring 17 is provided, it is possible to apply tension to the wafer 1 sufficient to divide the wafer into individual chips 6 even if the chip size is small (1 mm). This makes it possible to solve the problem of non-division along the dividing line that occurs when the chip size is small (1 mm).

[0071] Incidentally, after the dividing step (S140), the dicing tape 3 needs to be raised by a large amount to divide the wafer 1 into small-sized chips 6, and as a result, plastic deformation of the dicing tape 3 is unavoidable, causing excess slack in the entire wafer 1. It is difficult to sufficiently remove such excess slack even with the expansion retaining ring 18. For this reason, even if the expanded state retaining step (S160) using the expansion retaining ring 18 is performed immediately after the dividing step (S140), the expanded state of the dicing tape 3 cannot be retained.

[0072] Therefore, as shown in FIG. 7, the work dividing device 10 of the embodiment includes a heating step S150 after the dividing step S140 and before the expanded state maintaining step S160.

[0073] The heating step S150 will now be described in detail.

[0074] First, as shown in FIG. 10(A), the expand ring 16 is moved downward from the expansion position to the retracted position, and the expansion restricting ring 17 is moved upward from the restricting position to the retracted position. Next, the frame 4 of the wafer unit 2 and the fixing portion 7 are released from the fixing portion 7. Next, the door 34 (see FIG. 1) of the working chamber 20 is opened, and the wafer unit 2 is carried from the working chamber 20 to the heating chamber 30 through the opening 36 by a transport device (not shown). Then, the frame 4 of the wafer unit 2 is placed on the table 38 of the heating chamber 30 by the transport device (not shown) as shown in FIG. 10(B). After that, the door 34 is closed to seal the heating chamber 30.

[0075] Next, the control unit 48 in Fig. 6 drives the halogen lamp power supply 46 to turn on all of the halogen lamps 42, 42 ... as shown in Fig. 10(C). When the halogen lamps 42, 42 ... are turned on, the portions of the dicing tape 3 directly above the lamps are irradiated with direct infrared light from the halogen lamps 42, and the portions directly above between the lamps are irradiated with reflected infrared light from the reflector 44. This causes the entire surface of the dicing tape 3 to be heated uniformly.

[0076] The reflector 44 has a mountain-shaped bottom 44A disposed below the halogen lamps 42, and a pair of walls 44B, 44B disposed on both sides of the bottom 44A facing the dicing tape 3 and inclined outwardly of the surface of the dicing tape 3. By using a reflector 44 having such a configuration, the infrared light from the halogen lamps 42 can be efficiently reflected toward the area directly above between the lamps, so that the entire surface of the dicing tape 3 is heated more uniformly.

[0077] As the temperature of the dicing tape 3 rises due to the infrared light from the halogen lamp 42, the dicing tape 3 gradually thermally shrinks and the slack is removed; however, if all the slack in the entire dicing tape 3 is removed, the dicing tape 3 becomes too hard and the expandable retaining ring 18 cannot be attached to the frame 4.

[0078] Here, if the amount of slack in the dicing tape 3 caused by expansion is A, and the amount of slack in the dicing tape 3 required for the expansion retaining ring 18 to hold the dicing tape 3 in an expanded state is B, then if the amount of slack C, which is the amount of slack A minus the amount of slack B, is removed by thermal contraction, the dicing tape 3 can be held in an expanded state by the expansion retaining ring 18. However, if only the annular region 3B of the dicing tape 3 is thermally contracted, it is not possible to remove the amount of slack C, and even if the expansion retaining ring 18 is attached to the frame 4, the dicing tape 3 cannot be held in an expanded state.

[0079] Therefore, in the heating step S150 shown in FIG. 7, the dicing tape 3 is uniformly thermally shrunk as a whole, thereby removing the slack amount C. Specifically, since the dicing tape 3 in the embodiment is made of polyvinyl chloride, it tends to start thermally shrinking at about 60°C. For this reason, in the heating step S150, when the temperature of the dicing tape 3 reaches 60°C as measured by the radiation thermometer 50, the control unit 48 in FIG. 6 turns off the halogen lamp 42. As a result, the dicing tape 3 is gradually thermally shrunk by the residual heat, and when it returns to room temperature, only the slack amount C is removed. This completes the heating step S150. Note that the temperature at which the dicing tape 3 starts thermally shrinking varies depending on the material of the base material (polyester film, polyolefin film, and polyimide film), so it is sufficient to control the amount of infrared light emitted by the halogen lamp 42 and the timing of turning off the halogen lamp 42 according to the material of the base material.

[0080] When the heating step of S150 is completed, the door 34 (see FIG. 1) of the working chamber 20 is opened, and the wafer unit 2 is carried into the working chamber 20 from the heating chamber 30 through the opening 36 by a transport device (not shown). Then, the frame 4 of the wafer unit 2 is fixed to the fixing portion 7 as shown in FIG. 10(D).

[0081] Next, in the expanded state maintaining process of step S160 in Fig. 7, as shown in Fig. 10(E), the expansion retaining ring 18 is raised from the standby position toward the fitting position by the expansion retaining ring moving mechanism 28, and the fitting portion 26 is fitted into the upper surface 4A of the frame 4 at the fitting position. This causes the expanded state of the dicing tape 3 to be maintained by the expansion retaining ring 18. This completes the expanded state maintaining process of step S160.

[0082] As described above, the workpiece dividing method of the embodiment includes an expansion step of expanding the dicing tape 3, a heating step of applying heat to the entire dicing tape 3 to thermally shrink the entire dicing tape 3, and an expanded state maintaining step of expanding the dicing tape 3 and maintaining the expanded state of the dicing tape 3.Therefore, the expanded state of the dicing tape 3 can be maintained by the expansion maintaining ring 18 while effectively removing slack due to plastic deformation of the dicing tape 3 that occurs after expansion.

[0083] Furthermore, according to the embodiment of the work division method, as described above, an expansion restriction process (S120) using the expansion restriction ring 17 is provided, so that the problem of non-division of the planned division line that occurs when the chip size is a small chip (1 mm) can be eliminated.

[0084] As described above, according to the workpiece dividing method of the embodiment, the problem of non-division can be resolved, while the slack caused by the plastic deformation of the dicing tape 3 after expansion can be effectively removed.

[0085] In the above embodiment, an example using the expansion restriction ring 17 has been described, but the present invention is not limited to this embodiment. That is, even if the dicing tape 3 can be divided into individual chips 6 by a normal expansion operation without using the expansion restriction ring 17, the slackness caused by plastic deformation during expansion can be removed by the heating unit and heating process of the present invention.

[0086] In the embodiment, the halogen lamp 42 is illustrated as an example of the heating member of the present invention, but the present invention is not limited to this. For example, a far-infrared lamp or an infrared lamp can be used instead of the halogen lamp 42.

[0087] 5, the halogen lamp 42 is configured in a rod shape, but the shape is not limited to a rod shape. For example, a ring-shaped halogen lamp can also be used. In this case, it is preferable to arrange a plurality of ring-shaped halogen lamps 42 with different diameters in a concentric shape centered on the center of the dicing tape 3. This allows the entire dicing tape 3 to be heated uniformly. [Explanation of symbols]

[0088] 1...wafer, 2...wafer unit, 3...dicing tape, 3A...central region, 3B...annular region, 3C...fixed region, 4...frame, 5...planned division line, 6...chip, 7...fixed portion, 10...work division device, 12...expansion portion, 14...heating portion, 16...expanding ring, 17...expanding restricting ring, 18...expanding retaining ring, 20...working chamber, 22...expanding ring moving mechanism, 23...expanding restricting ring moving mechanism, 24...main body ring, 26...fitting portion, 28...expanding retaining ring moving mechanism, 30...heating chamber, 32...insulating wall, 34...door, 36...opening, 38...table, 40...radiant heat emitting member, 42...halogen lamp, 44...reflector, 46...halogen lamp power supply, 48...control portion, 50...radiation thermometer

Claims

1. A workpiece dividing device for dividing a workpiece attached to a dicing tape and mounted on a frame into individual chips along a planned dividing line, an expand ring that expands the dicing tape; A heating unit that thermally shrinks the dicing tape; an expansion retaining ring for retaining the expanded state of the heat-shrunk dicing tape; A workpiece dividing device comprising:

2. The heating unit includes: A heating member that radiates radiant heat; a heat reflecting member that reflects radiant heat radiated from the heating member toward the dicing tape; The workpiece dividing device according to claim 1 .

3. The heating member is a halogen lamp. The workpiece dividing device according to claim 2 .

4. A workpiece dividing method for dividing a workpiece attached to a dicing tape and mounted on a frame into individual chips along a planned dividing line, comprising: an expanding step of expanding the dicing tape; a heating step for thermally shrinking the dicing tape; an expanded state maintaining step of maintaining the expanded state of the heat-shrunk dicing tape; A workpiece dividing method comprising:

5. The heating step applies radiant heat to the dicing tape. The workpiece dividing method according to claim 4.

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