JP2007173770A - Re-taping process, and method of dividing substrate using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein tapes adhere locally and cannot be re-taped appropriately. <P>SOLUTION: In a re-taping process, an adhesive sheet S is adhered to the backside of a wafer W in which a background sheet B is adhered to the surface, and the background sheet is peeled. The method comprises a step of fixing the periphery to a background frame F1, and placing the non-adhesive surface side of the background sheet in which the surface side of a wafer is adhered to the side of an adhesive surface on a table 12 having nearly the same plane size as the wafer; a step of arranging a buffering 18 whose inner diameter has nearly the same size as the outer diameter of the wafer at the periphery of the wafer; a step of sticking the side of the adhesive surface of the adhesive sheet in which the periphery is fixed to an expand frame F2 to the backside of the wafer; a step of separating the table from the background sheet; and a step of peeling the background sheet from the surface of the wafer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tape replacement method and a substrate dividing method using the tape replacement method, and in particular, a tape replacement method used when cutting a workpiece such as a semiconductor or an electronic component material. The present invention also relates to a method for dividing a substrate using the tape reattachment method.

  In a semiconductor manufacturing process, a wafer having a semiconductor device or electronic component formed on the surface is subjected to an electrical test in a probing process, and then divided into individual chips (also referred to as dies or pellets) in a dicing process. Next, individual chips are die-bonded to a component base in a die bonding process. After die bonding, the chip is resin-molded to be a finished product such as a semiconductor device or an electronic component.

  Note that a protective sheet is attached to the front surface of the wafer before a semiconductor device, electronic component, or the like is formed on the front surface, and the back surface is ground (back grinding process) to ensure flatness and the like.

  After the probing process, as shown in FIG. 2, the adhesive sheet S (also referred to as a dicing sheet or dicing tape) S having an adhesive layer formed on one side is attached to the back side or the front side. The sheet S is mounted on a rigid ring-shaped frame F. In this state, the wafer W is transferred in the dicing process, between the dicing process and the die bonding process, and in the die bonding process.

  In the dicing process, a dicing apparatus that cuts the wafer by inserting grinding grooves into the wafer W with a thin grindstone called a dicing blade is used. The dicing blade is obtained by electrodepositing fine diamond abrasive grains with Ni, and an extremely thin one having a thickness of about 10 μm to 30 μm is used.

  The dicing blade is rotated at a high speed of 30,000 to 60,000 rpm to cut into the wafer W, and the wafer W is completely cut (full cut) or partially cut (half cut). In the case of the full cut, the adhesive sheet S attached to the back surface or the front surface of the wafer W is cut only about 10 μm from the front surface or the surface. Therefore, although the wafer W is cut into individual chips T, The chips T do not fall apart and the arrangement of the chips T is not broken, so that the wafer state is maintained as a whole.

  Further, without using a dicing blade, a laser beam having a focused point is irradiated inside the wafer W to form a modified region due to a multiphoton absorption phenomenon inside the wafer, and the wafer W is started from this modified region. Laser dicing has been proposed to cleave. Also in this laser dicing process, the wafer W is diced in the state as shown in FIG. 2, so that the arrangement of the chips T is not broken and the wafer state is maintained as a whole.

  Here, even after dicing and dividing into individual chips T in this way, an assembly of the chips T in which the arrangement of the chips T is not broken is also referred to as a wafer W for convenience.

  Thereafter, the wafer W is sent to a die bonding process. A die bonder is used in the die bonding process. In the die bonder, the wafer W is first placed on the chuck stage, and then the adhesive sheet S is expanded to widen the interval between the chips T so that the chips T can be easily picked up.

  Next, the chip T is pushed up with a pusher from below, and the chip T is picked up with a collet from above, and the chip T is bonded to a predetermined position of the base.

Such an expanding method and an expanding apparatus for expanding the adhesive sheet S and expanding the interval between the chips T have been conventionally used. In addition, various improvements and developments have been made in this expanding apparatus (for example, Patent Document 1 and Patent Document 2).
JP 2005-109044 A JP 2005-057158 A

  However, in a series of conventional wafer processing steps, as described above, the protective sheet is first attached to the front surface, and the adhesive sheet S is attached to the rear surface after the back surface processing (back grinding process, etc.) is completed. It is attached and the protective sheet on the surface is peeled off, so-called tape replacement is done, but when this tape replacement, both tapes are locally adhered to each other, and the tape replacement is good It has been pointed out that it cannot be done with

  In other words, since the wafer thickness is as small as about 0.75 mm, there is a high probability that the adhesive surfaces of both tapes will contact each other with this wafer in between. It is difficult to do and significantly reduces the productivity of tape replacement.

  In particular, when this tape replacement is performed manually, it depends on the skill of the worker and is difficult for the unskilled worker to perform. In addition, if this tape replacement is performed automatically, the above problems can be solved, but the process is complicated and it is not easy to automate the apparatus.

  The present invention has been made in view of such a situation, and in a series of processing steps of a wafer, a protective sheet is first attached to the front surface, and after the back surface processing (back grinding step or the like) is finished, In the so-called tape replacement, where the adhesive sheet is attached and the protective sheet on the surface is peeled off, both tapes are locally adhered to each other, and the tape cannot be replaced in a good state. It is an object of the present invention to provide a method for replacing a tape that can be eliminated and a method for dividing a substrate using the method for replacing a tape.

  In order to achieve the above object, the present invention attaches a second adhesive tape to the back surface of a substrate having a first adhesive tape attached to the front surface, and attaches the first adhesive tape from the surface of the substrate. In the method of replacing the tape to be peeled, the peripheral edge is fixed to the first annular member, and the non-adhesive surface side of the first adhesive tape in which the surface side of the substrate is adhered to the adhesive surface side is substantially the same as the substrate. A placing step of placing on a table of the same plane size, a buffering supplying step of arranging a buffer ring, which is an annular member having an inner diameter substantially the same as the outer diameter of the substrate, on the periphery of the substrate; A tape supplying step for adhering the adhesive surface side of the second adhesive tape whose peripheral edge is fixed to the annular member to the back surface side of the substrate, and a spacing step for separating the table and the first adhesive tape. And the first from the surface of the substrate. Providing a peeling step of peeling the adhesive tape, the taping replacement method, characterized in that it comprises a.

  In order to achieve the above object, the present invention has a second adhesive tape attached to the back surface of the substrate having the first adhesive tape attached to the front surface, and the first adhesion from the surface of the substrate. In the tape reattaching method for peeling the tape, the peripheral edge is fixed to the first annular member, and the non-adhesive surface side of the first adhesive tape in which the surface side of the substrate is adhered to the adhesive surface side is the substrate. And a tape cutting step for cutting the first adhesive tape in the vicinity of the outer periphery of the table, and an inner diameter substantially equal to the outer diameter of the substrate. A buffering supply step of arranging a buffer ring, which is an annular member of the same size, at the periphery of the substrate; and an adhesive surface side of the second adhesive tape whose periphery is fixed to the second annular member is a back surface side of the substrate Tape supply process to be attached to Reversing the second annular member upside down and placing the non-adhesive surface side of the second adhesive tape with the back side of the substrate attached to the adhesive surface side on the table; and And a peeling step of peeling the first adhesive tape from the surface.

  Furthermore, in the present invention, a linear modified region is formed along the planned dividing line on the front surface, back surface, or inside of the substrate, and the second adhesive tape is applied to the second adhesive tape after the tape replacement method is performed. There is provided a method for dividing a substrate, wherein the substrate is divided along the planned dividing line by stretching by applying tension.

  According to the present invention, since the buffer ring, which is an annular member whose inner diameter is substantially the same as the outer diameter of the substrate, is arranged on the periphery of the substrate, the adhesive surface side of the second adhesive tape is adhered to the rear surface side of the substrate. The buffering can reliably prevent the first adhesive tape and the second adhesive tape from contacting each other. Therefore, according to the present invention, the tape can be replaced in a good state.

  In addition, according to the present invention, since the contact between the first adhesive tape and the second adhesive tape can be reliably prevented, the productivity when dividing the substrate by applying tension to the second adhesive tape to stretch the substrate. Can be improved.

  Note that the front, back, or internal linear modified region is a linear region along the planned dividing line into individual chips of the wafer, and when formed on the front or back surface of the wafer, dicing is performed. Typical cutting is full cutting (half-cut) or partial cutting (half-cut) of the wafer with a blade, and when it is formed inside the wafer, internal cracks are caused by irradiation of the laser beam with the focal point inside the wafer. (Microcracks) are typical.

  In addition, “the front surface of the substrate” and “the back surface of the substrate” are simply used for convenience, and there is no change in the essence of the invention regardless of whether the front surface or the back surface is first.

  In the present invention, after the placing step, the first annular member is pushed into the table side, and the non-adhesive surface side of the first adhesive tape on the table periphery is provided on the table periphery. It is preferable to provide the temporary holding process hold | maintained by. In this way, if the first annular member is pushed into the table side and the first adhesive tape on the table periphery is held by the temporary fixing ring provided on the table periphery, the first adhesive tape and the second adhesive tape The distance between the two tapes can be increased and the contact between the two tapes can be reliably prevented.

  Note that, instead of the operation of pushing the first annular member toward the table side, the operation of fixing the first annular member and pushing up the table is also equivalent in terms of relative movement between the first annular member and the table.

  Moreover, in this invention, it is preferable to provide the tape cutting process of cut | disconnecting the said 1st adhesive tape currently hold | maintained with the said temporary fix | stop ring to the circumference after the said temporary holding process or the said buffering supply process. Thus, if the 1st adhesive tape is cut in the shape of a circumference, the 1st adhesive tape and the 1st annular member can be separated, and workability will improve greatly after that.

  In the present invention, following the spacing step, the second annular member is turned upside down, and the non-adhesive surface side of the second adhesive tape in which the back surface side of the substrate is adhered to the adhesive surface side is It is preferable to provide a reversing step for placing on a table. If the substrate is inverted and placed on the table again, workability is further improved.

  As described above, according to the present invention, the tape can be replaced in a good state.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a tape replacement method according to the present invention and a substrate dividing method using the tape replacement method according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view for explaining a flow according to the first embodiment of the tape replacement method according to the present invention, and the flow proceeds in the order of (a) to (f).

  As shown in FIG. 1 (a), in the tape changing apparatus 10, the bonding surface side (upper side in the figure) of the back grind sheet B as the first adhesive tape is the surface side of the wafer W as the substrate ( Affixed to the bottom of the figure. Further, the adhesion surface side (upper side in the drawing) of the periphery of the back grind sheet B is adhered to the lower surface of the back grind frame F1 which is the first annular member.

  Then, the non-adhesive surface side (the lower side of the figure) of the back grind sheet B is placed on the table 12 having the substantially same plane size as the wafer W, and the decompression means is placed on the table 12 as indicated by the arrow in the figure. (This is the mounting step.)

  The back grind frame F1 is fixed on the lifting ring 14. A temporary fixing ring 16 is provided on the periphery of the table 12. The inner diameter of the temporary fixing ring 16 is slightly larger than the outer diameter of the wafer W, and the outer diameter is slightly smaller than the inner diameters of the back grind frame F1 and the lifting ring 14. The thickness of the temporary fixing ring 16 is such that the cross section in which the plate thickness decreases linearly from the inner diameter to the outer diameter is a right triangle.

  Next, as shown in FIG. 1B, the elevating ring 14 is lowered as indicated by the arrows in the figure. Thereby, the back grind frame F1 is pushed downward (table 12 side). In this state, the back grind sheet B at the peripheral edge of the table 12 is slightly stretched and is in close contact with the upper surface of the temporary fixing ring 16. The temporary fixing ring 16 is provided with suction means, and the back grind sheet B is held as shown by the arrows in the figure in close contact with the upper surface of the temporary fixing ring 16 (the temporary holding step).

  As the adsorbing means for the temporary fixing ring 16, the temporary fixing ring 16 may be formed of a porous material (for example, porous ceramics) or a suction groove may be formed on the surface (upper surface) of the temporary fixing ring 16. A configuration connected to a decompression means (not shown) can be employed.

  Next, as shown in FIG. 1C, the buffer ring 18, which is an annular member whose inner diameter is slightly larger than the outer diameter of the wafer W, is placed on the lifting ring 14. As a result, the buffer ring 18 is disposed on the periphery of the wafer W (the buffering supply step).

  The buffer ring 18 is preferably formed of a material (for example, a fluororesin) having low adhesion to the adhesive (adhesive) of the back grind sheet B or the adhesive sheet S. With such a material, even if the buffer ring 18 mistakenly contacts the back grind sheet B or the pressure-sensitive adhesive sheet S, the trouble that both adhere to each other can be avoided.

  The thickness of the buffer ring 18 is such that the cross section in which the plate thickness decreases linearly from the diameter of the predetermined portion to the inner diameter is a right triangle, and the lower surface is parallel to the upper surface of the temporary fixing ring 16. The shape is preferred. By adopting such a shape, troubles in which the buffering 18 mistakenly contacts the back grind sheet B can be further avoided.

  Further, as shown in FIG. 1C, the back grind sheet B sucked and held by the temporary fixing ring 16 is cut into a circumferential shape by using the cutter 20 (the tape cutting step). As a result, the back grind sheet B adhered to the wafer W is separated from the back grind frame F1.

  Next, as shown in FIG. 1D, the expanded frame F <b> 2 that is the second annular member is supplied onto the buffer ring 18. The adhesive sheet S, which is the second adhesive tape, is bonded and fixed to the upper surface of the expanded frame F2 at the peripheral adhesive surface side (the lower side in the figure). Therefore, the adhesive surface side (the lower side of the figure) of the pressure-sensitive adhesive sheet S is adhered to the back side (the upper side of the figure) of the wafer W (the tape supply process).

  At this time, as described above, the lower surface of the buffer ring 18 is parallel to the upper surface of the temporary fixing ring 16, so that the trouble that the buffer ring 18 erroneously contacts the back grind sheet B is avoided.

  Further, the upper surface of the buffering 18 is parallel to the lower surface of the adhesive sheet S, and the arrangement in which the buffering 18 erroneously contacts the adhesive sheet S is avoided.

  Next, as shown in FIG. 1 (e), the table 12 and the back grind sheet B are spaced apart (hereinafter, the spacing step), and the expanded frame F2 is turned upside down to be shown in FIG. 1 (f). As described above, the non-adhesive surface side of the pressure-sensitive adhesive sheet S in which the back surface side of the wafer W is adhered to the adhesive surface side is placed on the table 12 (the reversal process). At this time, the back grind frame F1 is removed from the tape changing device 10.

  Further, the non-adhesive surface side of the pressure-sensitive adhesive sheet S is suction-fixed on the table 12 by a decompression unit as indicated by an arrow in FIG. Further, the elevating ring 14 is raised as shown by the arrow in FIG. 1 (f) to maintain the adhesive sheet S in a horizontal state. Then, the back grind sheet B is peeled off from the surface of the wafer W (the peeling step).

  Next, a flow according to a second embodiment of the tape reattaching method according to the present invention will be described. FIG. 2 is a cross-sectional view for explaining a flow according to the second embodiment of the tape replacement method according to the present invention, and the flow proceeds in the order of (a) to (f).

  As shown in FIG. 2 (a), in the tape changing apparatus 10, the bonding surface side (upper side in the figure) of the back grind sheet B that is the first adhesive tape is the surface side of the wafer W that is the substrate ( Affixed to the bottom of the figure. Further, the adhesion surface side (upper side in the drawing) of the periphery of the back grind sheet B is adhered to the lower surface of the back grind frame F1 which is the first annular member.

  Then, the non-adhesive surface side (the lower side of the figure) of the back grind sheet B is placed on the table 12 having the substantially same plane size as the wafer W, and the decompression means is placed on the table 12 as indicated by the arrow in the figure. (This is the mounting step.)

  Next, as shown in FIG. 2B, the back grind sheet B is cut into a circumferential shape using the cutter 20 in the vicinity of the outer periphery of the table 12 (the tape cutting step).

  As a result, the back grind sheet B adhered to the wafer W is separated from the back grind frame F1. The separated back grind frame F1 is removed from the tape changing device 10.

  Next, as shown in FIG. 2C, the buffer ring 21, which is an annular plate member whose inner diameter is slightly larger than the outer diameter of the wafer W, is placed on the elevating ring 14. Thereby, the buffer ring 21 is arranged on the peripheral edge of the wafer W, and the trouble that the adhesive sheet S mistakenly contacts the back grind sheet B is avoided (the buffering supply step).

  The buffer ring 21 is preferably formed of a material (for example, a fluororesin) having low adhesion to the adhesive (adhesive) of the back grind sheet B or the adhesive sheet S.

  Next, as shown in FIG. 2D, the expanded frame F <b> 2 that is the second annular member is supplied onto the buffer ring 21. The adhesive sheet S, which is the second adhesive tape, is bonded and fixed to the upper surface of the expanded frame F2 at the peripheral adhesive surface side (the lower side in the figure). Therefore, the adhesive surface side (the lower side of the figure) of the pressure-sensitive adhesive sheet S is attached to the back side (the upper side of the figure) of the wafer W (the tape supply process).

  At this time, as described above, the buffer ring 21 is arranged on the periphery of the wafer W, and the arrangement in which the adhesive sheet S erroneously contacts the back grind sheet B is avoided.

  Moreover, the upper surface of the buffering 21 is parallel to the lower surface of the adhesive sheet S, and the arrangement in which the buffering 21 accidentally contacts the adhesive sheet S is avoided.

  Next, as shown in FIG. 2 (e), the expanded frame F 2 is turned upside down, and the non-adhesive surface side of the adhesive sheet S with the back surface side of the wafer W adhered to the adhesive surface side is placed on the table 12. (The above is the reversal process).

  Further, the non-adhesive surface side of the pressure-sensitive adhesive sheet S is suction-fixed on the table 12 by a decompression unit as indicated by an arrow in FIG. Then, the back grind sheet B is peeled off from the surface of the wafer W (the peeling step).

  As described above, the back surface of the wafer W is bonded with the adhesive sheet S and placed on the table 12 by the series of tape replacement processes as in the first embodiment and the second embodiment. The peripheral edge is held by the expanded frame F2. Therefore, the following expanding process can be suitably performed.

  As a specific procedure of the expanding process, by removing the back grind sheet B after peeling from the state shown in FIG. 1 (f) and FIG. 2 (f), the buffering 18 and the buffering 21 are removed. Expand ready state. Then, the adhesive sheet S is expanded (expanded) by lowering the elevating ring 14 holding the expanded frame F2, and the wafer W is divided into individual chips T (see FIG. 3) by this expansion.

  Note that the adhesive sheet S can be similarly expanded by raising the table 12 instead of lowering the lifting ring 14.

  Moreover, the heating means can be provided in the wafer table 20, and expansion (expansion) of the adhesive sheet S can be promoted by heating the wafer W and the adhesive sheet S to a predetermined temperature.

  Further, at the same time as the expansion, the expansion of the pressure-sensitive adhesive sheet S is promoted by cooling the pressure-sensitive adhesive sheet S by ejecting cooling air from an air ejection hole (not shown) provided in the elevating ring 14. You can also

  In the expanded state, the wafer W can be image-recognized from above by an image recognition device (not shown) to identify the divided state of the wafer W.

  According to the present embodiment described above, since the buffer ring 18 and the buffer ring 21 are disposed on the periphery of the wafer W, the adhesive surface side of the adhesive sheet S is adhered to the back surface side of the wafer W. And the buffer ring 21 can reliably prevent the contact between the back grind sheet B and the adhesive sheet S. Therefore, according to the present invention, the tape can be replaced in a good state.

  In addition, according to the present embodiment, since the contact between the back grind sheet B and the adhesive sheet S can be reliably prevented, the productivity when the wafer W is divided is improved by applying tension to the adhesive sheet S and stretching it. Can be made.

  As mentioned above, although the embodiment of the method for dividing the tape according to the present invention and the method for dividing the substrate using the method for replacing the tape has been described, the present invention is not limited to the above-described embodiment, and various aspects are possible. Can be taken.

  For example, in the present embodiment, the buffer ring 18 and the buffer ring 21 having the cross-sectional shape shown in the figure are used, but other cross-sectional shapes may be used. A substantially similar effect can be obtained.

  Further, in this embodiment, the tape replacement method is applied to the division of the wafer W. However, the use of the tape replacement method is not limited to this, and the tape application on the substrate is applied. If it is replaced, it can be suitably applied to various uses.

Sectional drawing explaining the flow of 1st Embodiment of the tape replacement method which concerns on this invention Sectional drawing explaining the flow of 2nd Embodiment of the tape replacement method which concerns on this invention Perspective view showing wafer mounted on frame

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Tape changing apparatus, 12 ... Table, 14 ... Lifting ring, 16 ... Temporary fixing ring, 18, 21 ... Buffering, B ... Back grind sheet, F1 ... Back grind frame, F2 ... Expand frame, S ... Adhesion Sheet, T ... chip, W ... wafer

Claims (7)

In the method of reattaching the tape, the second adhesive tape is adhered to the back surface of the substrate having the first adhesive tape adhered to the surface, and the first adhesive tape is peeled off from the surface of the substrate.
The peripheral edge is fixed to the first annular member, and the non-adhesive surface side of the first adhesive tape having the surface side of the substrate attached to the adhesive surface side is placed on a table having substantially the same plane size as the substrate. A mounting process to perform,
A buffering supply step of arranging a buffer ring, which is an annular member having an inner diameter of substantially the same size as the outer diameter of the substrate, at the periphery of the substrate;
A tape supplying step of adhering the adhesive surface side of the second adhesive tape, the periphery of which is fixed to the second annular member, to the back surface side of the substrate;
A spacing step of spacing the table and the first adhesive tape;
And a peeling step of peeling the first adhesive tape from the surface of the substrate.   Subsequent to the placing step, the first annular member is pushed into the table side, and the non-adhesive surface side of the first adhesive tape at the table periphery is held by a temporary fixing ring provided at the table periphery. The tape replacement method according to claim 1, further comprising a holding step.   3. The tape replacement according to claim 2, further comprising a tape cutting step of cutting the first adhesive tape held by the temporary holding ring into a circumferential shape following the temporary holding step or the buffering supply step. Method.   Subsequent to the spacing step, the second annular member is turned upside down, and the non-adhesive surface side of the second adhesive tape with the back surface side of the substrate attached to the adhesive surface side is placed on the table. The tape replacement method according to any one of claims 1 to 3, further comprising an inversion step. In the method of reattaching the tape, the second adhesive tape is adhered to the back surface of the substrate having the first adhesive tape adhered to the surface, and the first adhesive tape is peeled off from the surface of the substrate.
The peripheral edge is fixed to the first annular member, and the non-adhesive surface side of the first adhesive tape having the surface side of the substrate attached to the adhesive surface side is placed on a table having substantially the same plane size as the substrate. A mounting process to perform,
A tape cutting step of cutting the first adhesive tape circumferentially in the vicinity of the outer periphery of the table;
A buffering supply step of arranging a buffer ring, which is an annular member having an inner diameter of substantially the same size as the outer diameter of the substrate, at the periphery of the substrate;
A tape supplying step of adhering the adhesive surface side of the second adhesive tape, the periphery of which is fixed to the second annular member, to the back surface side of the substrate;
A reversing step of turning the second annular member upside down and placing the non-adhesive surface side of the second adhesive tape on which the back surface side of the substrate is adhered to the adhesive surface side on the table;
And a peeling step of peeling the first adhesive tape from the surface of the substrate. A linear modified region is formed along the planned dividing line on the front surface, back surface or inside of the substrate,
6. The substrate is divided along the planned dividing line by applying tension to the second adhesive tape and stretching the second adhesive tape after performing the tape replacement method according to claim 1. A substrate dividing method.   The substrate dividing method according to claim 6, wherein the substrate is a wafer, and the wafer is divided into individual chips.

Images