JP2022089324A - Method for separating protective tape - Google Patents

Abstract

To provide a method for separating a protective tape without fail that can surely separate the protective tape from a surface of a wafer.SOLUTION: The method includes: a thermal compression bonding step of putting a separation tape on an outer periphery of a protective tape to press a heat bar, and thermally compressing and bonding the separation tape to the outer periphery of the protective tape; and a protective tape separation step of pulling the separation tape off to separate the protective tape from a surface of a wafer. In the thermal compression bonding step, the heat bar is pressed against the separation tape at a plurality of positions and the separation tape is thermally compressed and bound to the protective tape.SELECTED DRAWING: Figure 5

Description

The present invention relates to a protective tape peeling method for peeling a protective tape attached to the surface of a wafer.

A wafer in which a plurality of devices such as ICs and LSIs are partitioned by a planned division line and formed on the front surface is formed by attaching a protective tape to the front surface and grinding the back surface by a grinding device to form a desired thickness, and then dicing. It is divided into individual device chips by a device and a laser processing device, and is used for electric devices such as mobile phones and personal computers.

In addition, after grinding the back surface of the wafer, the peeling tape is thermocompression-bonded to the protective tape attached to the surface of the wafer, and the protective tape is peeled off from the surface of the wafer with the thermocompression-bonded peeling tape. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 11-16862

However, the release tape is peeled off from the protective tape due to the case where the protective tape is a hard tape such as polyethylene terephthalate (PET) or the case where the thermocompression bonding force of the release tape to the protective tape is insufficient. There is a problem that the protective tape cannot be reliably peeled off from the surface of the wafer.

The present invention has been made in view of the above facts, and a main technical object thereof is to provide a protective tape peeling method capable of reliably peeling a protective tape from the surface of a wafer.

In order to solve the above-mentioned main technical problem, according to the present invention, it is a protective tape peeling method for peeling off the protective tape attached to the surface of the wafer, and a peeling tape is laid on the outer periphery of the protective tape to provide a heat bar. The thermocompression bonding step includes a thermocompression bonding step of pressing and thermocompression bonding the peeling tape to the outer periphery of the protective tape, and a thermocompression bonding step of pulling the peeling tape to peel the protective tape from the surface of the wafer. The present invention provides a protective tape peeling method in which the heat bar is positioned at a plurality of positions of the peeling tape and pressed, and the peeling tape is thermocompression bonded to the protective tape.

The present invention is suitable when the protective tape is polyethylene terephthalate.

The protective tape peeling method of the present invention includes a thermocompression bonding step in which a peeling tape is laid on the outer periphery of the protective tape, the heat bar is pressed, and the peeling tape is thermocompression bonded to the outer periphery of the protective tape, and the peeling tape is pulled. The protective tape peeling step of peeling the protective tape from the surface of the wafer is included, and in the thermocompression bonding step, the heat bars are positioned and pressed at a plurality of places of the peeling tape, and the peeling tape is heated to the protective tape. Since it is crimped, the protective tape can be reliably peeled off by using the peeling tape.

It is a perspective view which shows the mode of attaching a protective tape to a wafer. It is an overall perspective view of the grinding apparatus which carries out the grinding process which grinds the back surface of a wafer. It is a partially enlarged perspective view which shows the embodiment of a grinding process. It is a perspective view which shows the mode of placing a wafer on a protective tape peeling apparatus. (A) A perspective view showing an embodiment of the thermocompression bonding step, (b) a side view at the time of performing the thermocompression bonding step shown in (a), and (c) an embodiment in which the peeling tape is thermocompression bonded by the thermocompression bonding step. It is a perspective view which shows. It is a perspective view which shows the embodiment of the protective tape peeling process.

Hereinafter, embodiments relating to the protective tape peeling method configured based on the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a wafer 10 as a workpiece to which the protective tape peeling method of the present embodiment is applied. The wafer 10 is formed on a surface 10a in which a plurality of devices 12 are partitioned by a planned division line 14, and a protective tape T is attached to the surface 10a. The protective tape T is, for example, a resin tape made of polyethylene terephthalate (PET) and is thermocompression bonded to the surface 10a of the wafer 10.

FIG. 2 shows an overall perspective view of the grinding device 1 for grinding the wafer 10 of the present embodiment. The grinding device 1 grinds the holding means 3 disposed in the device housing 2, the grinding means 4 for grinding the back surface 10b of the wafer 10 held by the holding means 3, and the grinding means 4 in the Z-axis direction (vertical direction). It is provided with at least an elevating means 5 for elevating and elevating.

The holding means 3 includes a chuck table 31 having a holding surface 31a defined by an X-axis direction and a Y-axis direction orthogonal to the X-axis direction and substantially forming a horizontal plane. The chuck table 31 is configured to be rotatable by a rotation driving means (not shown). The holding surface 31a is composed of a member having air permeability, is connected to a suction means (not shown), and by operating the suction means, a suction negative pressure is supplied to the holding surface 31a. The chuck table 31 is an arbitrary position in the X-axis direction, for example, a loading / unloading position for loading and unloading the wafer 10 on the front side in the drawing by an X-axis moving means housed inside the apparatus housing 3 (not shown). And, it is moved to the grinding position where the grinding is performed directly under the grinding means 4.

The grinding means 4 rotates a rotating shaft 41, a grinding wheel 42 arranged at the lower end of the rotating shaft 41, a plurality of grinding grinds 43 arranged in an annular shape on the lower surface of the grinding wheel 42, and the rotating shaft 41. At least the electric motor 44, the support portion 45 that supports the grinding means 4, and the Z-axis moving base 46 that is supported up and down in the Z-axis direction together with the support portion 45 in the vertical wall portion 2a of the apparatus housing 2. I have. The elevating means 5 converts the rotational motion of the pulse motor 51 into a linear motion via the ball screw 52 rotated by the pulse motor 51 and transmits it to the Z-axis moving base 46, and the grinding means 4 is transmitted in the Z-axis direction (up and down). It is possible to move it to any position in the direction). The grinding device 1 includes control means (not shown), and its operation is controlled by a control signal instructed by the control means.

The grinding process performed in the grinding device 1 will be described more specifically with reference to FIGS. 2 and 3.

As shown in FIG. 2, the wafer 10 is placed on the holding surface 31a of the chuck table 31 positioned at the loading / unloading position with the protective tape T side facing downward and the back surface 10b side exposed upward. The suction means is operated to suck and hold. Next, the X-axis moving means described above is operated to move the chuck table 31 in the X-axis direction and position it at the grinding position directly under the grinding means 4. Then, the rotation driving means (not shown) is operated to rotate the chuck table 31 in the direction indicated by the arrow R1 at a predetermined rotation speed (for example, 300 rpm), and the rotating shaft 41 of the grinding means 4 is rotated. It is rotated at a predetermined rotation speed (for example, 6000 rpm) in the direction indicated by the arrow R2. Next, the above-mentioned elevating means 5 is operated to lower the grinding means 4 in the direction indicated by the arrow R3, the grinding wheel 43 is brought into contact with the back surface 10b of the wafer 10, and grinding is performed at a predetermined speed (for example, 1 μm / sec). While feeding, the wafer 10 is ground to a predetermined thickness to be thinned. When carrying out this grinding process, the thickness measuring means (not shown) can be operated to measure the thickness of the wafer 10 while performing the grinding process.

After the above-mentioned grinding process is performed, the above-mentioned elevating means 5 is operated to raise the grinding means 4 and stop the electric motor 44. Next, the suction means for supplying the suction negative pressure to the holding surface 31a of the chuck table 31 is stopped, and the wafer 10 is carried out from the chuck table 31. Before carrying out the wafer 10 from the chuck table 31, it is preferable to operate a cleaning means (not shown) to clean and dry the back surface 10b side of the wafer 10. After the wafer 10 is carried out from the chuck table 31, a protective tape peeling method for peeling the protective tape T attached to the surface 10a of the wafer 10 is carried out.

In carrying out the protective tape peeling method of the present embodiment, first, the wafer 10 carried out from the grinding device 1 is conveyed to the protective tape peeling device 7 (only a part thereof is shown) shown in FIG. As shown in the figure, the protective tape peeling device 7 includes a holding means 72. The holding means 72 includes a chuck table 74 having a holding surface 74a defined by an X-axis direction and a Y-axis direction orthogonal to the X-axis direction and substantially forming a horizontal plane. The chuck table 74 is configured to be rotatable by a rotation driving means (not shown). The holding surface 74a is composed of a member having air permeability, is connected to a suction means (not shown), and by operating the suction means, a suction negative pressure is supplied to the holding surface 74a. The chuck table 74 is configured to be movable in the X-axis direction by an X-axis moving means (not shown).

After the wafer 10 is conveyed to the chuck table 74 of the protective tape peeling device 7, a thermocompression bonding step is performed. When performing the thermocompression bonding step, first, as shown in FIG. 4, the back surface 10b side is directed downward and the protective tape T side is directed upward, and the table 74 is placed on the chuck table 74. Next, a suction means (not shown) is operated to suck and hold the wafer 10 on the holding surface 74a of the chuck table 74. Here, as shown in FIG. 4, the peeling tape 6 is laid at a predetermined position 10c (indicated by a two-dot chain line) on the outer circumference of the protective tape T. As the peeling tape 6 of the present embodiment, a thermocompression bonding tape that exhibits adhesive strength by heating is used, and is preferably selected from, for example, a polyolefin-based or polyester-based resin tape. When a polyolefin-based resin tape is used, it is preferable to select from polyethylene, polypropylene, or polystyrene. When a polyester tape is used, it is preferable to select from either polyethylene terephthalate or polyethylene naphthalate. In the present embodiment, it is assumed that the polyethylene tape is adopted as the peeling tape 6, and the description will be described below.

As described above, if the peeling tape 6 is laid at the tape attachment position 10c on the outer circumference of the protective tape T, the chuck table 74 is rotated in the direction indicated by R4 as shown in FIG. 5A. The position of the chuck table 74 in the X-axis direction is adjusted by operating the X-axis moving means (not shown), and the protective tape is placed on the sticking portion 62 of the peeling tape 6 laid at the tape sticking position 10c. The heat bar 78 of the heating means 76 arranged in the peeling device 7 is positioned. The heat bar 78 is formed, for example, in a flat plate shape having a width corresponding to the width of the peeling tape 6, and the cross section of the tip portion 78a of the heat bar 78 is formed so that the tip portion 78a is pointed downward and has a convex shape. There is. The heat bar 78 is made of a metal having excellent heat conduction, is connected to a heating heater (not shown), and is configured to be adjustable so that the temperature of the tip portion 78a becomes a predetermined temperature.

As described above, when the heat bar 78 is positioned on the sticking portion 62, the heating means 76 is operated to heat the tip portion 78a of the heat bar 78 so that the temperature becomes 120 ° C to 140 ° C. The temperature is close to the melting temperature of the peeling tape 6 made of polyethylene, and is a temperature at which the peeling tape 6 softens and exhibits adhesiveness. When a thermocompression bonding tape made of another material is selected as the peeling tape 6, the temperature is adjusted to soften and exhibit adhesiveness according to the selected material.

Next, as shown in FIG. 5B, the heat bar 78 is lowered in the direction indicated by the arrow R5 (indicated by a solid line) by an elevating means (not shown) and pressed against the attachment portion 62 of the peeling tape 6. Then, the peeling tape 6 is thermocompression-bonded to the protective tape T to form a thermocompression-bonding portion 64a. As can be seen from FIG. 5C, the thermocompression bonding portion 64a is formed so as to extend in the width direction on the tip end side of the bonding portion 62 of the peeling tape 6. After the thermocompression bonding portion 64a is formed, the heat bar 78 is raised and the X-axis moving means of the chuck table 74 described above is operated to move the heat bar 78 in the direction indicated by the arrow R6 as shown in FIG. 5 (b). The thermocompression bonding portion 64a is positioned at a position adjacent to the previously formed thermocompression bonding portion 64a in the X-axis direction, and the heat bar 78 is pressed against the bonding portion 62 to form the thermocompression bonding portion 64b. Similarly, the heat bar 78 is positioned and pressed at a position adjacent to the thermocompression bonding portion 64b in the X-axis direction to form the thermocompression bonding portion 64c. That is, as shown in FIG. 5C, the heat bars 78 are positioned and pressed at a plurality of positions of the peeling tape 6, and the peeling tape 6 is thermocompression bonded to the protective tape T. With the above, the thermocompression bonding process is completed.

When the thermocompression bonding step described above is performed, as shown in FIG. 6, the protective tape T is peeled from the surface 10a of the wafer 10 by pulling the grip portion 66 of the peeling tape 6 in the direction indicated by the arrow R7. The protective tape peeling process is completed.

According to the above-described embodiment, in the thermocompression bonding step, the heat bars 78 are positioned and pressed at a plurality of locations of the peeling tape 6, and the peeling tape 6 is thermocompression bonded to the protective tape T. Therefore, the protective tape peeling step. In, the protective tape T can be reliably peeled off by using the peeling tape 6.

In the above-described embodiment, the heat bar 78 is pressed against the peeling tape 6 three times to form three thermocompression bonding portions 64a to 64c extending in the direction orthogonal to the X-axis direction. It is not limited, and may be two or more articles. Further, in the above-described embodiment, the thermocompression bonding portions 64a to 64c are formed by a straight line extending in a direction orthogonal to the X-axis direction, but are not necessarily limited to being formed in a linear shape, and are pressed at a plurality of points, for example. It may be thermocompression bonded.

Further, in the above-described embodiment, when the protective tape peeling method is carried out after the grinding step is carried out, it is conveyed to the protective tape peeling device 7 and the thermal pressure bonding step and the protective tape peeling step are carried out. The heating means 76 is arranged in the grinding apparatus 1 on which the grinding process is performed, and the wafer 10 is placed on the chuck table 31 of the grinding apparatus 1 with the protective tape T side turned upward. Then, the suction and holding may be carried out to carry out the above-mentioned thermal crimping step and protective tape peeling step.

1: Grinding means 2: Equipment housing 2a: Vertical wall portion 3: Holding means 31: Chuck table 31a: Holding surface 4: Grinding means 41: Rotating shaft 42: Grinding wheel 43: Grinding grindstone 44: Electric motor 45: Support portion 46 : Z-axis moving base 5: Elevating means 51: Pulse motor 52: Ball screw 6: Peeling tape 62: Adhesive parts 64a to 64c: Thermal crimping part 66: Grip part 7: Protective tape peeling device 72: Holding means 74 : Chuck table 74a: Holding surface 76: Heating means 78: Heat bar 78a: Tip portion 10: Waha 10a: Front surface 10b: Back surface 12: Device 14: Scheduled division line T: Protective tape

Claims (2)

It is a protective tape peeling method that peels off the protective tape attached to the surface of the wafer.
A thermocompression bonding process in which a peeling tape is laid on the outer circumference of the protective tape, the heat bar is pressed, and the peeling tape is thermocompression bonded to the outer circumference of the protective tape.
A protective tape peeling step of pulling the peeling tape to peel the protective tape from the surface of the wafer,
Including
In the thermocompression bonding step, a protective tape peeling method in which the heat bar is positioned at a plurality of locations of the peeling tape and pressed, and the peeling tape is thermocompression bonded to the protective tape. The protective tape peeling method according to claim 1, wherein the protective tape is polyethylene terephthalate.

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