JP2016213282A - Peeling method of protective tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a peeling method of a protective tape capable of peeling a protective tape from a tabular workpiece easily and inexpensively, by using a hot melt adhesive.SOLUTION: A peeling method of a protective tape for peeling a protective tape, stuck to the first surface of a tabular workpiece, from the tabular workpiece includes: a holding step of suction holding the first surface of the tabular workpiece and the second surface opposite thereto; an adhesive coating step of coating near the edge of the protective tape with heated hot melt adhesive following to the holding step; and a peeling step of pulling the hot melt adhesive hardening and adhering to the protective tape, following to the adhesive coating step, and then peeling the protective tape from the tabular workpiece.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a protective tape peeling method for peeling a protective tape attached to a first surface (front surface) of a plate-like workpiece such as a semiconductor wafer.

  In the semiconductor device manufacturing process, after forming a plurality of devices on the surface of a semiconductor wafer made of silicon or the like, the back side of the semiconductor wafer is ground and thinned to a predetermined thickness, and then the semiconductor wafer is divided into individual device chips. Is common.

  In order to protect the device surface during backside grinding of a semiconductor wafer (hereinafter sometimes referred to simply as a wafer), a protective tape is attached to the device surface side of the wafer, and the wafer is placed on the chuck table of the grinding device via the protective tape. Is sucked and held, and the back surface of the wafer is ground.

  The process of dividing the wafer into device chips is performed by blade dicing with a cutting device, laser dicing with a laser processing device, etc., but before dicing, the outer periphery is ground to a dicing tape attached to an annular frame. A frame unit is configured by pasting the back side of the wafer.

  Therefore, when moving from the wafer grinding process to the dividing process, it is necessary to attach a dicing tape with an outer peripheral part attached to the annular frame on the backside of the wafer and peel off the protective tape attached to the wafer surface. There is.

  As a conventional method for peeling off the protective tape from the wafer, Japanese Patent Application Laid-Open No. 2011-086772 discloses a method in which the peeling tape is thermocompression bonded to the protective tape and the peeling tape is pulled to peel off the protective tape from the wafer. .

  As another method for peeling off the protective tape attached to the back surface of the wafer, a first protective tape peeled from the first semiconductor wafer is prepared, and the second protective tape attached to the second semiconductor wafer is prepared. The first protective tape is overlapped with the first protective tape, the portion where the first protective tape and the second protective tape overlap each other is ultrasonically welded, and the first protective tape is pulled to pull the second protective wafer from the second semiconductor wafer. Japanese Patent No. 4823383 discloses a method for removing a protective tape for removing the protective tape.

JP 2011-086772 A Japanese Patent No. 4823383

  However, in the peeling method of the protective tape disclosed by patent document 1, since the peeling tape is disposable, there exists a subject that the cost of a peeling tape will start.

  Moreover, in the peeling method of the protective tape disclosed in Patent Document 2, there is a problem that the first protective tape and the second protective tape are not sufficiently welded due to the influence of the adhesive (adhesive) of the protective tape. However, there are still problems such as breaking a thinly ground wafer with a pressure required for welding, and avoiding applying a high temperature as much as possible.

  The present invention has been made in view of the above points, and the object of the present invention is to provide a protection capable of easily and easily peeling a protective tape from a plate-like workpiece by using a hot melt adhesive. It is to provide a tape peeling method.

  According to the present invention, there is provided a protective tape peeling method for peeling a protective tape attached to a first surface of a plate-like workpiece from the plate-like workpiece, the first of the plate-like workpiece. A holding step of sucking and holding the second surface side opposite to the surface with the holding surface of the holding table, and an adhesive for applying a heated hot melt adhesive to the vicinity of the periphery of the protective tape after performing the holding step After performing the application step and the adhesive application step, pulling the hot melt adhesive that has been cured and adhered to the protective tape, and separating the protective tape from the plate-like workpiece, Provided is a method for peeling off a protective tape characterized by comprising the above.

  Preferably, the method for peeling off the protective tape further comprises a peeling means bonding step for bonding a peeling means to the hot melt adhesive after performing the adhesive application step and before performing the peeling step, In the peeling step, the peeling means is pulled to peel the protective tape from the plate-like workpiece.

  Preferably, the peeling means includes a rotating roller having a rotating shaft parallel to the holding surface of the holding table.

  Preferably, the protective tape peeling method further includes an adhesive tape attaching step of attaching an adhesive tape to the second surface of the plate-shaped workpiece before the holding step is performed. The plate-like workpiece is held by the holding table via the adhesive tape.

  According to the method for peeling a protective tape of the present invention, a peeling start point can be formed by pulling a hot melt adhesive applied and cured on the protective tape, and the protective tape can be easily formed without damaging the plate-like workpiece. And reliably peel from the workpiece.

  The protective tape can be peeled at a low cost by using a hot melt adhesive that is available at a very low cost compared to the peeling tape. Further, if the peeling means is bonded to the hot melt adhesive, the protective tape can be easily peeled from the plate-like workpiece by pulling the peeling means.

It is a perspective view which shows a holding | maintenance step. FIG. 2A is a perspective view showing an adhesive application step, and FIG. 2B is a cross-sectional view showing the adhesive application step. It is sectional drawing which shows a peeling step. It is sectional drawing which shows 2nd Embodiment of an adhesive agent coating step. It is a perspective view after peeling step implementation. It is a perspective view which shows 2nd Embodiment of a holding | maintenance step.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a perspective view showing a holding step of the first embodiment is shown. In order to protect a plurality of devices formed on the surface of the wafer 11, the first surface (front surface) of a semiconductor wafer 11 (hereinafter sometimes simply referred to as a wafer) 11, which is a kind of plate-like workpiece, is used. A protective tape 12 is attached to the surface.

  As the protective tape 12, one in which an acrylic adhesive layer (glue layer) is provided on the surface of a base material such as polyethylene vinyl chloride or polyolefin is generally used. Here, the protective tape 12 is preferably an ultraviolet curable tape whose adhesive strength is reduced by irradiation of ultraviolet rays.

  In the description of the present embodiment, the example in which the semiconductor wafer 11 is employed as the plate-like workpiece has been described. However, the plate-like workpiece is not limited to the semiconductor wafer 11, and other wafers such as an optical device wafer, Other plate-like workpieces such as resin substrates and ceramic substrates are included.

  As shown in FIGS. 1 and 2, a dicing tape 16 as an adhesive tape is sucked and held on the holding table 14. In the protective tape peeling method of this embodiment, the surface is protected via the dicing tape 16. A holding step is performed in which the back surface (second surface) side of the wafer 11 to which the tape 12 is adhered is sucked and held by the holding surface of the holding table 14.

  After the protective tape 12 is attached to the front surface of the wafer 11, for example, the protective tape 12 side is sucked and held by a chuck table of a grinding device to expose the back surface of the wafer 11, and the back surface of the wafer 11 is ground to pre-determine the wafer 11 A back grinding step is performed to reduce the thickness of the back surface.

  When this back grinding step is performed, the protective tape 12 is pressed against the surface of the wafer 11 by grinding pressure. Therefore, it is preferable to reduce the sticking force by irradiating the protective tape 12 stuck on the surface of the wafer 11 held on the holding table 14 with ultraviolet rays.

  After performing the holding step, as shown in FIG. 2, an adhesive application step of applying the heated hot melt adhesive 20 to the vicinity of the periphery of the protective tape 12 by the glue gun 18 is performed. Here, the hot melt adhesive 20 is an adhesive that is melted and bonded by applying heat (for example, 80 to 100 ° C.), and is solid before heating. As a material, a thermoplastic resin such as ethylene vinyl acetate (EVA) or polyolefin is used. After applying by heating, it cures quickly and exerts adhesive strength.

  The hot melt adhesive is provided as a stick (bar) shape, a pellet (grain) shape, or a sheet shape. A tool for using a stick-like tool is called a glue gun 18, and a heater for heating a hot melt adhesive that is solid at room temperature is built in the glue gun 18.

  In the adhesive application step of the present embodiment, it is important to apply to the edge of the protective tape 12 at the edge of the outer periphery. If the applied area is too inside, a peeling start point cannot be formed, and the cured hot melt adhesive 20 If it is pulled, the protective tape 12 may be peeled off. Preferably, the hot melt adhesive 20 applied with the glue gun 18 is applied in an amount of about 0.02 to 0.2 g per time.

  The hot melt adhesive 20 applied in the vicinity of the outer peripheral edge of the wafer 11 quickly cures and adheres to the protective tape 12. Therefore, after performing the adhesive application step, the hot melt adhesive 20 that has been cured and adhered to the protective tape 12 is pulled, and the peeling step of peeling the protective tape 12 from the wafer 11 is performed.

  In FIG. 2A, the peeling unit 22 includes a rotating roller 24 having a rotating shaft parallel to the holding surface of the holding table 14 and a pair of gripping portions 26 disposed at both ends of the rotating roller 24.

  Each gripping portion 26 is composed of a pair of gripping members 26a and 26b facing each other, and the gripping members 26a and 26b are movable in directions toward and away from each other. Here, the roller 24 is disposed so as to be rotatable and reciprocally movable in the horizontal direction.

  Preferably, the peeling step includes steps (A) to (D) shown in FIG. First, as shown in FIG. 3A, the roller 24 is rotated in the direction of the arrow R1 to contact the hot melt adhesive 20 applied in the vicinity of the outer peripheral edge of the protective tape 12, and the hot melt adhesive 20 is Adhere to both the protective tape 12 and the roller 24.

  Next, as shown in FIG. 3B, the roller 24 is rotated in the direction of the arrow R <b> 2 to peel the outer peripheral portion of the protective tape 12 from the outer peripheral portion of the wafer 11 to form the peeling start point of the protective tape 12. Here, the adhesive force of the hot melt adhesive 20 cured and adhered to the protective tape 12 and the adhesive force of the hot melt adhesive 20 and the roller 24 are larger than the adhesive force of the protective tape 12 to the wafer 11. The peeling start point of the protective tape 12 can be easily formed by rotating the roller 24 bonded to the hot melt adhesive in the direction of the arrow R2. That is, since the hot melt adhesive 20 has a property compatible with the protective tape 12, it is firmly bonded to the protective tape 12.

  After forming the peeling start point of the protective tape 12, as shown in FIG. 3C, the peeled portion of the protective tape 12 is gripped by a pair of gripping members 26a and 26b constituting the gripping portion 26. When the protective tape 12 is gripped by the gripping portion 26, the roller 24 is pulled to separate the roller 24 from the hot melt adhesive 20.

  Next, as shown in FIG. 3D, when the protective tape 12 is pulled in the direction of the arrow while the end portions of the protective tape 12 are held by the holding members 26a and 26b, the protective tape 12 is easily peeled from the wafer 11. be able to.

  Here, since the hot melt adhesive 20 has fluidity, the roller 24 can be easily brought into contact with the hot melt adhesive 20 only by lightly contacting the roller 24 with the solidified hot melt adhesive 20 without requiring a large pressure. Glued to.

  Referring to FIG. 4, there is shown a cross-sectional view showing the peeling step of the second embodiment of the present invention. In the peeling step of the present embodiment, when the hot melt adhesive 20 is applied to the vicinity of the outer peripheral edge of the protective tape 12 by the glue gun 18, the roller 24 is disposed outside the outer peripheral edge of the protective tape 12 to protect it. The roller 24 prevents the fluid hot-melt adhesive 20 applied to the outer periphery of the tape 12 from dripping downward from the outer periphery of the protective tape 12.

  Since the application position of the hot melt adhesive 20 is preferably near the outer peripheral edge of the protective tape 12, the effect of preventing the hot melt adhesive 20 from dripping down from the outer peripheral edge to the protective tape 12 by the roller 24 is great. is there.

  When the application of the hot-melt adhesive 20 to the vicinity of the outer peripheral edge of the protective tape 12 is completed, as shown in FIG. Adhere to the cured hot melt adhesive 20.

  Referring to FIG. 5, a perspective view of the state after performing the peeling step is shown. On the surface of the wafer 11, devices 15 such as ICs and LSIs are formed in each region partitioned by a plurality of division lines 13 formed in a lattice pattern. The back surface of the wafer 11 is bonded to a dicing tape 16 sucked and held on the holding table 14.

  Referring to FIG. 6, a perspective view of a second embodiment of the holding step is shown. In the present embodiment, the outer peripheral portion of the dicing tape 16 is attached to the annular frame 28, and the wafer 11 having the protective tape 12 attached to the surface thereof is supported by the annular frame 28 via the dicing tape 16. The wafer 11 having the protective tape 12 attached to the surface is sucked and held by the holding table 14 </ b> A via the dicing tape 16.

  After the holding step shown in FIG. 6 is performed, the peeling step for peeling the protective tape 12 from the wafer 11 is performed in substantially the same manner as the peeling step shown in FIG. 3 or FIG.

  In the protective tape peeling method of the above-described embodiment, the hot melt adhesive 20 applied to the protective tape 12 is pulled by the roller 24 to form a peeling start point, and after the peeling start point is formed, the grip portion 26 Since the protective tape 12 is peeled from the wafer 11 by gripping the peeled portion, the protective tape 12 can be peeled without damaging the wafer 11.

  By using the hot melt adhesive 20 that can be obtained at a very low cost compared to the peeling tape used in the prior art, the protective tape 12 can be peeled at a low cost. Since the hot-melt adhesive 20 is compatible with the material of the protective tape 12, the hot-melt adhesive 20 is firmly bonded to the protective tape 12, and the protective tape 12 can be easily peeled from the wafer 11 by pulling the cured hot-melt adhesive 20. Can do.

DESCRIPTION OF SYMBOLS 11 Semiconductor wafer 12 Protective tape 14 Holding table 16 Dicing tape 18 Glue gun 20 Hot melt adhesive 22 Peeling means 24 Roller 26 Grip part 26a, 26b Grip member 28 Annular frame

Claims (4)

A protective tape peeling method for peeling off a protective tape attached to a first surface of a plate-like workpiece from the plate-like workpiece,
A holding step of sucking and holding the second surface side of the plate-like workpiece opposite to the first surface with the holding surface of the holding table;
After performing the holding step, an adhesive application step of applying a heated hot melt adhesive to the vicinity of the periphery of the protective tape;
After performing the adhesive coating step, pulling the hot melt adhesive that has been cured and adhered to the protective tape, and peeling the protective tape from the plate-like workpiece;
A method for peeling off a protective tape, comprising: Before performing the peeling step after performing the adhesive application step, further comprising a peeling means bonding step for bonding a peeling means to the hot melt adhesive;
2. The method of peeling a protective tape according to claim 1, wherein, in the peeling step, the peeling tape is pulled to peel the protective tape from the plate-like workpiece.   3. The method for peeling off a protective tape according to claim 1, wherein the peeling means includes a rotating roller having a rotating shaft parallel to the holding surface of the holding table. Before carrying out the holding step, further comprising an adhesive tape attaching step for attaching an adhesive tape to the second surface of the plate-like workpiece,
The method for peeling off a protective tape according to claim 1, 2 or 3, wherein in the holding step, the plate-like workpiece is held by the holding table via the adhesive tape.

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