Chip expansion method and chip expansion device

Abstract

Provided are a wafer expansion method and a wafer expansion device, which equally expand the intervals between devices in the long side direction and the short side direction. The method expands a wafer having rectangular devices respectively formed in a plurality of regions divided by a plurality of predetermined dividing lines, and expands the intervals between adjacent devices. The method comprises: a jig preparation step, preparing an annular jig having an elliptical opening, the elliptical opening having: a short axis portion for sticking an exposed adhesive tape in the direction in which the short sides of the devices are arranged to limit the width of the exposed adhesive tape; and a long axis portion for sticking an exposed adhesive tape in the direction in which the long sides of the devices are arranged, which limits the width of the exposed adhesive tape to be wider than the short axis portion; and an expansion step, pushing the wafer from the adhesive tape side by a cylindrical pressing member having an outer circumference corresponding to the outer circumference of the wafer to move the wafer away from the annular frame, expanding the exposed adhesive tape between the wafer and the annular frame, and expanding the intervals between adjacent devices.

Description

Technical Field

[0001] The present invention relates to a wafer expansion method and a wafer expansion device, which expand a wafer having rectangular devices formed in a plurality of regions divided by a plurality of predetermined dividing lines, thereby increasing the interval between adjacent devices. Background Art

[0002] A wafer having a plurality of devices such as ICs and LSIs formed on the front side is divided by a plurality of predetermined dividing lines and is divided into individual device chips by a dicing device or a laser processing device. The divided device chips are used in electronic devices such as mobile phones and personal computers.

[0003] In addition, regarding a wafer that is placed on a ring frame via an adhesive tape and divided into individual device chips, an expansion device expands the adhesive tape to increase the intervals between the individual device chips, thereby facilitating pickup (see, for example, Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2002-334852

[0005] However, when a chip having a plurality of rectangular devices formed by a plurality of predetermined dividing lines is expanded evenly, since there are more portions of the adhesive tape between devices (the adhesive tape to be expanded) in the short side direction of the devices than in the long side direction of the devices, there is a problem that the short side distances between the devices are narrower than the long side distances, making it impossible to expand at even intervals.

[0006] The above problem also occurs in a technique (see, for example, Japanese Patent Application Publication No. 2005-129607) in which a modified layer is formed inside a predetermined dividing line of a wafer, an adhesive tape to which the wafer is attached is expanded to apply external force, and the wafer is divided into individual device chips. Summary of the invention

[0007] Therefore, the object of the present invention is to provide a chip expansion method and a chip expansion device, which can evenly expand the long side direction and short side direction intervals between the devices when expanding the adhesive tape of a chip on which a plurality of rectangular devices are attached.

[0008] According to one embodiment of the present invention, a method for expanding a wafer is provided, wherein a wafer having rectangular devices formed in a plurality of regions divided by a plurality of predetermined dividing lines is expanded to enlarge the intervals between adjacent devices, wherein the method for expanding the wafer comprises the following steps: a wafer preparation step, wherein the wafer is supported by an annular frame having an opening for accommodating the wafer with the aid of an adhesive tape, and the plurality of predetermined dividing lines have been divided or a dividing starting point is formed on the plurality of predetermined dividing lines; a jig preparation step, wherein an annular jig having an elliptical opening is prepared, the elliptical opening having a short axis portion and a long axis portion, the short axis portion being for sticking the exposed adhesive tape between the wafer and the annular frame in the direction in which the short sides of the devices are arranged to limit the width of the exposed adhesive tape, and the long axis portion being for sticking the exposed adhesive tape in the direction in which the long sides of the devices are arranged to limit the width of the exposed adhesive tape to be wider than the short axis portion; and a fixing step. A process of placing the annular frame on a cylindrical frame fixing member and placing the annular jig on the annular frame, thereby fixing the annular frame and the annular jig to the cylindrical frame fixing member; and an expansion process of, after the implementation of the fixing process, pushing the wafer from the adhesive tape side by a cylindrical pushing member having an outer circumference corresponding to the outer circumference of the wafer to move the wafer away from the annular frame, expanding the exposed adhesive tape between the wafer and the annular frame, and widening the interval between adjacent devices. In the expansion process, when the wafer is moved away from the annular frame by the cylindrical pushing member, the exposed adhesive tape in the direction in which the short sides of the devices are arranged is adhered to the short axis portion of the annular jig to limit the width of the exposed adhesive tape in the short axis portion, and the exposed adhesive tape in the direction in which the long sides of the devices are arranged is adhered to the long axis portion of the annular jig to limit the width of the exposed adhesive tape in the long axis portion to be wider than that in the short axis portion.

[0009] According to another aspect of the present invention, there is provided a wafer expansion device, which expands a wafer having rectangular devices formed in a plurality of regions divided by a plurality of predetermined dividing lines, respectively, to widen the intervals between adjacent devices, wherein the wafer expansion device comprises: a cylindrical frame fixture; a cylindrical pressing member which is accommodated in the cylindrical frame fixture and can be raised and lowered relative to the cylindrical frame fixture; and a wafer unit which comprises an annular frame which is mounted on the cylindrical frame fixture and has the function of expanding the wafer having been divided along a plurality of predetermined dividing lines or having a dividing starting point formed on a plurality of predetermined dividing lines. The invention relates to an annular frame having an opening for accommodating the wafer, the annular frame supporting the wafer by means of an adhesive tape; an annular jig mounted on the annular frame, the annular jig having an elliptical opening, the elliptical opening having a short axis portion and a long axis portion, the short axis portion being used for sticking the exposed adhesive tape between the wafer and the annular frame in the direction in which the short sides of the device are arranged to limit the width of the exposed adhesive tape, the long axis portion being used for sticking the exposed adhesive tape in the direction in which the long sides of the device are arranged to limit the width of the exposed adhesive tape to be wider than that of the short axis portion; and a fixing unit fixing the annular frame and the annular jig to the cylindrical frame fixing piece.

[0010] According to the chip expansion method of the present invention, there is included a fixing step of fixing an annular jig to the upper part of an annular frame, wherein the annular jig is used to make the intervals between rectangular devices equal, so that the adhesive tape along the short side direction of the devices where more rectangular devices are arranged is stretched more than the adhesive tape along the long side direction of the devices, thereby making it possible to evenly expand the intervals in the long side direction and the intervals in the short side direction between the devices.

[0011] According to the wafer expansion device of the present invention, a ring-shaped jig is fixed on a ring-shaped frame, and the ring-shaped jig is used to make the intervals between rectangular devices equal. Therefore, the adhesive tape along the short side direction of the devices where more rectangular devices are arranged is stretched more than the adhesive tape along the long side direction of the devices, so that the intervals in the long side direction and the intervals in the short side direction between the devices can be evenly expanded. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 (a) is a three-dimensional view of two wafers and a ring frame with an adhesive tape installed. Figure 1 (b) is a perspective view of a wafer supported on one side of the annular frame via an adhesive tape.

[0013] Figure 2 It is a perspective view of a wafer expansion device according to an embodiment of the present invention.

[0014] Figure 3 (a) is Figure 2 A top view of the fixture is shown. Figure 3(b) is Figure 3 The AA line cross-sectional view (cross-sectional view of the short axis portion) in (a) is shown in FIG. Figure 3 (c) is Figure 3 BB line cross-sectional view (cross-sectional view of the long axis portion) in (a).

[0015] Figure 4 It is a perspective view showing a state where the frame fixing step is performed.

[0016] Figure 5 (a) is Figure 4 The CC line section view in Figure 5 (b) is Figure 4 DD line section view.

[0017] Figure 6 (a) is the case when the exposed adhesive tape is expanded. Figure 5 The cross-sectional view corresponding to (a) is Figure 6 (b) is the case when the exposed adhesive tape is expanded. Figure 5 (b) The corresponding cross-sectional view.

[0018] Figure 7 This is a partial plan view of a wafer in which the exposed adhesive tape is expanded so that the intervals between devices in the long-side direction and the short-side direction are evenly enlarged.

[0019] Description of symbols

[0020] 2, 2': chip; 2a, 2a': front side; 4, 4': predetermined dividing line; 6, 6': device; 8: annular frame; 8a: opening; 10: adhesive tape; 10a: exposed adhesive tape; 12: chip expansion device; 14: cylindrical frame fixing part; 16: cylindrical pushing part; 20: fixture; 20a: short axis part; 20b: long axis part; 20c: opening. DETAILED DESCRIPTION

[0021] Hereinafter, preferred embodiments of a wafer expanding method and a wafer expanding device according to the present invention will be described with reference to the accompanying drawings.

[0022] In the chip expansion method of the present invention, a chip preparation process is first implemented to prepare a chip that is supported by an adhesive tape on a ring frame having an opening for accommodating the chip, and a plurality of predetermined dividing lines have been divided or dividing starting points are formed on the plurality of predetermined dividing lines.

[0023] The wafer prepared in the wafer preparation step may be, for example, Figure 1The wafer 2 or 2' shown. Both the wafer 2 and 2' are formed into a disk shape by a suitable semiconductor material such as Si (silicon). The front surface 2a of the wafer 2 on one side is divided into a plurality of rectangular areas by a grid-shaped predetermined dividing line 4, and rectangular devices 6 such as ICs and LSIs are formed in the plurality of rectangular areas. In addition, the front surface 2a' of the wafer 2' on the other side is divided into a plurality of rectangular areas by a predetermined dividing line 4' which is partially grid-shaped and partially sawtooth-shaped, and rectangular devices 6' such as ICs and LSIs are formed in the plurality of rectangular areas.

[0024] Reference Figure 1 (b) is used to illustrate that in the chip preparation process, the back side 2b of the chip 2 is firstly pasted on the adhesive tape 10 to form a chip unit 11, and the periphery of the adhesive tape 10 is fixed to an annular ring frame 8 having a circular opening 8a for accommodating the chip 2. Alternatively, the front side 2a of the chip 2 may be pasted on the adhesive tape 10. Next, a cutting process is performed on the predetermined dividing line 4 using a cutting device (not shown) having a cutting tool in a rotatable manner, or a laser processing device (not shown) for irradiating laser light is used to perform ablation process on the predetermined dividing line 4 to divide the predetermined dividing line 4. Alternatively, a laser processing device may be used to form a starting point for dividing such as a modified layer with reduced strength inside the predetermined dividing line 4 by laser processing. In addition, in Figure 1 In (b), the exposed adhesive tape between the periphery of the wafer 2 and the inner periphery of the annular frame 8 is indicated by reference numeral 10a. Figure 1 In (b), for convenience of explanation, the dividing lines for dividing the planned dividing line 4 and the dividing starting points formed inside the planned dividing line 4 are not shown.

[0025] The other wafer 2' having the device 6' arranged thereon can be divided along the dividing line 4' or a dividing starting point can be formed inside the dividing line 4' by using a laser processing device after the wafer 2' is attached to the adhesive tape 10 fixed to the annular frame 8.

[0026] Hereinafter, one wafer 2 supported by the annular frame 8 via the adhesive tape 10 will be described with reference to the drawings.

[0027] After the wafer preparation step is performed, a frame fixing step is performed to fix the annular frame 8 to a cylindrical frame fixing member capable of placing the annular frame 8 on the upper end. The frame fixing step can be performed using the wafer expansion device 12 (see Figure 2 ) to implement.

[0028] like Figure 2As shown, the chip expansion device 12 at least comprises: a cylindrical frame fixing part 14, which fixes the annular frame 8, and the annular frame 8 has an opening portion 8a for accommodating the chip 2 that has been divided on the dividing predetermined line 4 or has a dividing starting point formed on the dividing predetermined line 4, and supports the chip 2 with the help of the adhesive tape 10; and a cylindrical pushing part 16, which has an outer periphery corresponding to the outer periphery of the chip 2, pushes the chip 2 from the adhesive tape 10 side to move the chip 2 away from the annular frame 8, thereby expanding the exposed adhesive tape 10a between the chip 2 and the annular frame 8.

[0029] The outer and inner diameters of the cylindrical frame fixture 14 correspond to those of the annular frame 8, and the annular frame 8 can be placed on the upper end of the cylindrical frame fixture 14. In addition, a plurality of clamps 18 are attached to the upper outer peripheral edge of the cylindrical frame fixture 14 at intervals in the circumferential direction.

[0030] A cylindrical pressing member 16 is provided inside the cylindrical frame fixing member 14. The outer circumference of the cylindrical pressing member 16 corresponds to the outer circumference of the wafer 2, and the outer circumference of the cylindrical pressing member 16 of the illustrated embodiment is formed to be slightly larger than the outer circumference of the wafer 2. In addition, the cylindrical pressing member 16 is configured to be relatively movable relative to the cylindrical frame fixing member 14 by an appropriate driving unit such as an air cylinder or an electric cylinder. Furthermore, when the cylindrical pressing member 16 is relatively raised relative to the cylindrical frame fixing member 14 by the driving unit, the cylindrical pressing member 16 presses the wafer 2 supported by the annular frame 8 by the adhesive tape 10 from the adhesive tape 10 side, so that the wafer 2 is separated from the annular frame 8 fixed to the cylindrical frame fixing member 14, thereby expanding the exposed adhesive tape 10a between the wafer 2 and the annular frame 8. In addition, it is preferable that a plurality of rollers are disposed in an annular shape at the upper end of the cylindrical pressing member 16 to reduce the frictional resistance with the adhesive tape 10 and promote the expansion of the adhesive tape 10 to which the wafer 2 is attached.

[0031] Reference Figure 2 as well as Figure 3As an explanation, the wafer expansion device 12 includes an annular jig 20 for making the intervals between the rectangular devices 6 equal, and the jig 20 is arranged on the upper part of the annular frame 8 placed on the upper end of the cylindrical frame fixing member 14. The jig 20 has an elliptical opening 20c, and the elliptical opening 20c has a short axis portion 20a, when the wafer 2 is moved away from the annular frame 8 by the cylindrical pressing member 16, the short axis portion 20a is attached to the exposed adhesive tape 10a in the direction in which the short sides of the devices 6 are arranged, and the width of the exposed adhesive tape 10a is limited; and a long axis portion 20b, the long axis portion 20b is attached to the exposed adhesive tape 10a in the direction in which the long sides of the devices 6 are arranged, and the width of the exposed adhesive tape 10a is limited to be wider than the short axis portion 20a. The radial dimension of the short-axis portion 20a is shorter than the radial dimension of the long-axis portion 20b (20a<20b).

[0032] Reference Figure 4 To explain, in the frame fixing process, first, the ring frame 8 supporting the wafer 2 via the adhesive tape 10 is placed on the upper end of the cylindrical frame fixing member 14. Next, the jig 20 is placed on the upper part of the ring frame 8. At this time, Figure 4 As shown, the positional relationship between the wafer 2 and the jig 20 is adjusted so that the short side direction of the device 6 is consistent with the short axis portion 20a of the jig 20 and the long side direction of the device 6 is consistent with the long axis portion 20b of the jig 20. In addition, the annular frame 8 is pressed together with the jig 20 to the upper end of the cylindrical frame fixing member 14 by a plurality of clamps 18 for fixing.

[0033] After the frame fixing process is implemented, the expansion process is implemented, in which the chip 2 is pushed from the adhesive tape 10 side by a cylindrical pushing component 16 having an outer circumference slightly larger than the outer circumference of the chip 2 to move the chip 2 away from the annular frame 8, and the exposed adhesive tape 10a between the chip 2 and the annular frame 8 is expanded to increase the interval between the devices 6.

[0034] Reference Figure 5 and Figure 6 To explain, in the expansion process, from Figure 5 From the initial position shown (the position where the upper end of the cylindrical frame fixing part 14 and the upper end of the cylindrical pressing part 16 are almost at the same height), the cylindrical pressing part 16 is raised relative to the cylindrical frame fixing part 14 by the driving unit, and the wafer 2 supported by the annular frame 8 via the adhesive tape 10 is pressed from the adhesive tape 10 side by the cylindrical pressing part 16. As a result, the wafer 2 is separated from the annular frame 8 fixed to the cylindrical frame fixing part 14, and the exposed adhesive tape 10a between the wafer 2 and the annular frame 8 is expanded. In addition, as Figure 5As shown, the inner diameter of the cylindrical pressing member 16 is slightly larger than the diameter of the wafer 2 before expansion.

[0035] In the expansion process, when the chip 2 is moved away from the annular frame 8 by the cylindrical pushing member 16, the exposed adhesive tape 10a in the direction in which the short sides of the device 6 are arranged is adhered to the short axis portion 20a of the jig 20, and the width of the exposed adhesive tape 10a is restricted to be narrower by the short axis portion 20a. At the same time, the exposed adhesive tape 10a in the direction in which the long sides of the device 6 are arranged is adhered to the long axis portion 20b, and the width of the exposed adhesive tape 10a is restricted to be wider by the long axis portion 20b compared with the short axis portion 20a.

[0036] In this way, by limiting the width of the exposed adhesive tape 10a along the short side direction of the device 6 where more rectangular devices 6 are arranged to be narrower, and limiting the width of the exposed adhesive tape 10a along the long side direction of the device 6 where fewer rectangular devices 6 are arranged to be wider than the short axis portion 20a, the exposed adhesive tape 10a in the short side direction of the device 6 can be stretched more than the exposed adhesive tape 10a in the long side direction of the device 6. Figure 6 As shown in FIG. 1 , in the expanded wafer 2, the expansion degree of the device 6 in the short side direction is greater than the expansion degree of the device 6 in the long side direction, and the length L1 of the device 6 in the short side direction of the wafer 2 as a whole is greater than the length L2 of the device 6 in the long side direction. Therefore, the shape of the expanded wafer 2 is an elliptical shape as a whole. In addition, as for the adhesive tape 10 below the device 6, since the device 6 is attached, its expansion is suppressed compared with the adhesive tape 10 between the devices 6. Therefore, in this embodiment, as shown in FIG. Figure 7 As shown, the interval s1 in the long-side direction and the interval s2 in the short-side direction between the devices 6 can be equally extended.

Claims

1. A method for expanding a wafer, wherein a wafer having rectangular devices formed in a plurality of regions divided by a plurality of predetermined dividing lines is expanded to enlarge the interval between adjacent devices, wherein: The wafer expansion method has the following steps: a wafer preparation step of preparing a wafer which is supported by an annular frame having an opening for accommodating the wafer via an adhesive tape and has been divided along a plurality of predetermined dividing lines or has dividing starting points formed on the plurality of predetermined dividing lines; A jig preparation step, preparing an annular jig having an elliptical opening, the elliptical opening having a short axis portion and a long axis portion, the short axis portion being for sticking the exposed adhesive tape between the wafer and the annular frame in the direction in which the short sides of the devices are arranged to limit the width of the exposed adhesive tape, and the long axis portion being for sticking the exposed adhesive tape in the direction in which the long sides of the devices are arranged to limit the width of the exposed adhesive tape to be wider than that of the short axis portion; a fixing step of placing the annular frame on a cylindrical frame fixing member and placing the annular jig on the annular frame, thereby fixing the annular frame and the annular jig to the cylindrical frame fixing member; as well as An expansion process, after the fixing process is performed, a cylindrical pressing member having an outer circumference corresponding to the outer circumference of the wafer is used to push the wafer from the adhesive tape side to move the wafer away from the annular frame, and the exposed adhesive tape between the wafer and the annular frame is expanded to increase the interval between adjacent devices. In the expansion process, when the wafer is moved away from the annular frame by the cylindrical pressing member, the exposed adhesive tape in the direction in which the short sides of the device are arranged is attached to the short axis portion of the annular jig to limit the width of the exposed adhesive tape in the short axis portion, and the exposed adhesive tape in the direction in which the long sides of the device are arranged is attached to the long axis portion of the annular jig to limit the width of the exposed adhesive tape in the long axis portion to be wider than that in the short axis portion. When the exposed adhesive tape is expanded, the short axis portion contacts the exposed adhesive tape surface. In the fixing step, a plurality of clamps are provided on the upper outer peripheral edge of the cylindrical frame fixing member, and the plurality of clamps fix the annular frame and the annular jig to the cylindrical frame fixing member.

2. A wafer expansion device, which expands a wafer having rectangular devices formed in a plurality of regions divided by a plurality of predetermined dividing lines, thereby increasing the interval between adjacent devices, wherein: The expansion device of the chip has: Cylindrical frame fixings; A cylindrical pressing member is housed in the cylindrical frame fixing member and can be raised and lowered relative to the cylindrical frame fixing member; A wafer unit comprising an annular frame mounted on the cylindrical frame fixture, having an opening for receiving wafers that have been split along a plurality of predetermined splitting lines or have splitting starting points formed along a plurality of predetermined splitting lines, the annular frame supporting the wafers by means of an adhesive tape; An annular jig mounted on the annular frame, the annular jig having an elliptical opening, the elliptical opening having a short axis portion and a long axis portion, the short axis portion being for the exposed adhesive tape between the wafer and the annular frame in the direction in which the short sides of the devices are arranged to be attached to limit the width of the exposed adhesive tape, and the long axis portion being for the exposed adhesive tape in the direction in which the long sides of the devices are arranged to be attached to limit the width of the exposed adhesive tape to be wider than that of the short axis portion; as well as a plurality of clamps, which fix the annular frame and the annular jig to the cylindrical frame fixture, When the exposed adhesive tape is expanded, the short axis portion contacts the exposed adhesive tape surface. The plurality of clamps are arranged on the upper outer periphery of the cylindrical frame fixing member.

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