CN1715019A - Protective belt cutting method and device for semiconductor wafer - Google Patents

Abstract

A method for cutting a protective tape of a semiconductor wafer. The cutter head runs relatively along the outer periphery of the semiconductor wafer, cuts the protective tape attached to the surface of the semiconductor wafer along the shape of the wafer, and has a positioning function along the outer periphery. The outer periphery of the semiconductor wafer of the notch, so that the cutter head travels relatively, and the indentation is formed in the front half of the notch on the outer periphery of the wafer during the process of the relative travel of the cutter head, so that the cutter head rotates by itself to make its tip Facing the center of the wafer. And in the second half of the notch, the cutter head is rotated by itself so that its tip faces the outer periphery of the wafer.

Description

Protective tape cutting method and protective tape cutting device of semiconductor wafer

technical field

The invention relates to a method and a device for cutting a protective tape attached on the surface of a semiconductor wafer along the outer circumference of the semiconductor wafer by making the cutter head relatively run along the outer periphery of the semiconductor wafer.

Background technique

Conventionally, as a cutting device for a protective tape, a structure is known in which after the protective tape is supplied and attached to the surface of a wafer placed and held on a stage, a blade is pierced through the protective tape. In this state, by rotating the table and moving the cutter head along the outer periphery of the wafer relative to each other, the protective tape is cut along the outer periphery of the wafer (for example, refer to Japanese Patent Application Laid-Open No. 2004-25402).

Generally, a positioning plane (Japanese: Oriente-Sionflat) and a notch for positioning are formed on the outer periphery of the wafer. In the case of a wafer having a positioning plane, by sliding and displacing the bit to the center of the wafer, etc., it is possible to move relatively along the linear positioning plane. However, since the notch formed on the outer periphery of the wafer has a small shape with a circumferential width and a depth in the radial direction of about several millimeters, at the formation site of the notch, the cutter head will move along the wafer circumferential direction. And pass. Thus, the tape cutting process is performed with a part of the protective tape facing the inside of the notch.

However, since the adhesive surface of the protective tape facing the inside of the notch is exposed, dust generated during the surface treatment process adheres to the exposed adhesive surface inside the notch, and the adhered dust is deposited on the subsequent If it comes off during the handling process, it may stain the surrounding area. In addition, once the protective tape inside the notch is covered with dust, it will become an obstacle when optically detecting the notch for wafer alignment.

Contents of the invention

In view of the above facts, the main object of the present invention is to suppress the adhesion of dust and the like without leaving much of the protective tape exposed inside the notch during the protective tape cutting process of the notched semiconductor wafer.

In order to achieve the above objects, the present invention employs the following structures.

A method for cutting off a protective tape of a semiconductor wafer, the cutter head is relatively run along the outer periphery of the semiconductor wafer, and the protective tape attached to the surface of the semiconductor wafer is cut along the shape of the wafer. The method includes the following processes:

A tool head running process in which the tool heads move relative to each other along the outer periphery of the semiconductor wafer having positioning notches on the outer periphery;

During the running process of the cutter head, the first half of the cutter head is made to rotate by itself in the first half of the notch formed on the outer periphery of the wafer so that the cutter head faces the center of the wafer;

In the second half of the notch, the cutter head is rotated by itself so that the tip of the cutter faces the outer periphery of the wafer during the second rotation.

According to the method for cutting the protective tape of the semiconductor wafer according to the present invention, once the cutter head reaches the notch forming part, it will rotate by itself, and the cutter head will enter the inside of the notch. That is, the portion of the protective tape remaining inside the notch is small, and the exposed adhesive surface is not large.

In this way, on the adhesive surface of the protective tape portion remaining inside the notch of the wafer that has undergone the protective tape cutting process, the adhesion of grinding dust and the like can be suppressed, so in the subsequent process, it can be effectively suppressed. fall off and contaminate the surrounding environment.

Again, in the process of cutter head walking, both the cutter head can be made to walk along the periphery of the semiconductor wafer, or the cutter head can be fixed to make the semiconductor wafer rotate around the central axis, and, in the first rotation process And in the second rotation process, while rotating the semiconductor wafer, the cutter head is rotated around the axis near the back edge of the cutter head.

Also, it is preferable to include a changing process of changing the radius of rotation of the cutter head. With this method, the radius of rotation of the tool head can be changed and adjusted according to the shape of the semiconductor wafer.

Also, it is preferable to apply an elastic force to the tip of the tool head so as to approach the center axis of the semiconductor wafer during the tool head traveling process, the first autorotation rotation process and the second autorotation rotation process.

Moreover, in order to achieve the above objects, the present invention employs the following configurations.

A protective tape cutting device for a semiconductor wafer, which makes the cutter head run relatively along the outer periphery of the semiconductor wafer, and cuts the protective tape attached to the surface of the semiconductor wafer along the shape of the wafer. The above-mentioned device includes the following elements:

A supporting device that is parallel to the axis passing through the center of the wafer, centered on the axis near the back edge of the cutter head, and rotatably supports the cutter head;

A tool head running device that moves the tool head relative to the outer periphery of the semiconductor wafer having a notch for positioning on the outer periphery;

Rotate the tool head so that its tip faces the center of the wafer in the first half of the notch recessed and formed on the outer periphery of the wafer, and turn the bit so that its tip faces the wafer in the second half of the notch The cutter head on the outer periphery rotates automatically.

Adopt the above-mentioned structure, because in the first half of the notch, the cutter head is rotated by itself so that the tip of the cutter faces the center of the wafer and enters the inside of the notch, while in the second half of the notch, the cutter head rotates in the opposite direction to Since the tip of the knife advances while facing the outer periphery of the wafer, there is little protective tape remaining inside the notch, and the exposed bonding surface is not large.

In this way, the portion of the protective tape remaining inside the notch is very small, and the exposed bonding surface is not large. As a result, on the adhesive surface of the protective tape portion remaining inside the notch, the adhesion of grinding dust, etc., can be suppressed, so in the subsequent process, the surrounding area will not be stained by the dust falling off, and the notch will not be formed. Some obstacles to optical detection.

Also, as the tool head traveling device, for example, it can be enumerated: a structure that has a first driving device that rotates the tool head around the semiconductor wafer; or includes a holding device that holds the semiconductor wafer and makes the holding device surround the holding device The structure of the second driving device that rotates the central axis of the held semiconductor wafer, etc.

Furthermore, the device for cutting the protective tape of the semiconductor wafer according to the present invention preferably includes an adjusting device for adjusting the radius of rotation of the cutter head. With this structure, the radius of rotation of the tool head can be changed and adjusted according to the shape of the semiconductor wafer.

Furthermore, it is preferable to apply elastic force to the tip of the bit so as to approach the center axis of the semiconductor wafer.

Description of drawings

In order to explain the invention, some forms considered to be preferable at present are shown in the drawings, but it should be understood that the invention is not limited to the configurations and methods shown in the drawings.

Fig. 1 is a perspective view showing the whole of a protective tape sticking device according to an embodiment of the present invention.

Fig. 2 is a front view of the tape cutting mechanism.

Fig. 3 is a perspective view of main parts of the tape cutting mechanism.

Fig. 4 is a plan view of main parts of the tape cutting mechanism.

Fig. 5 is a side view of main parts of the tape cutting mechanism.

Fig. 6 is an explanatory diagram of the operation of the device of the embodiment.

Fig. 7 is an explanatory diagram of the operation of the device of the embodiment.

Fig. 8 is an explanatory diagram of the operation of the device of the embodiment.

Fig. 9 is an explanatory diagram of the operation of the device of the embodiment.

Fig. 10 is a plan view showing the tape cutting operation at the notch portion.

Detailed ways

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a perspective view showing the overall structure of a protective tape sticking device. The protective tape attaching device includes: a wafer supply/recovery unit 1 loaded with a cassette C containing semiconductor wafers (hereinafter referred to as "wafers") W; a wafer transfer mechanism 3 having a robot arm 2; a reference table 4. The chuck 5 on which the wafer W is placed for adsorption and holding; the tape supply part 6 for supplying the protective tape T for surface protection to the wafer W; the protective tape with a separation layer supplied from the tape supply part 6 T is the separation layer recovery part 7 that peels and recovers the separation layer s; the attachment unit 8 that attaches the protective tape T to the wafer W that is placed on the chuck 5 and is adsorbed and held; The tape cutting mechanism 9 that cuts and cuts the protective tape T along the outer shape of the wafer W; the peeling unit 10 that peels the unnecessary tape T' attached to the wafer W after the cutting process; and the peeling unit 10 The tape collection section 11 and the like for the stripped useless tape T' to be collected in a package will be described below in terms of each of the above-mentioned structural sections and their mechanisms.

Two cassettes C can be loaded in parallel in the wafer supply/collection unit 1 . In each cassette C, a plurality of wafers W inserted in a horizontal posture with their wiring patterns facing upward are accommodated in multiple layers.

The mechanical arm 2 equipped on the wafer transfer mechanism 3 can move forward and backward horizontally, and at the same time can drive the whole body to rotate and lift. At the front end of the robot arm 2, there is a horseshoe-shaped vacuum suction wafer holding part 2a. The wafer holding part 2a is inserted into the gap between the wafers W stored in the cassette C in multiple layers, and the wafer is held from the back. The wafer W is sucked and held, and the sucked and held wafer W is pulled out from the cassette body C, and transported in the order of the reference table 4 , the clamp table 5 , and the wafer supply/recovery unit 1 .

The role of the reference table 4 is to align the wafer W carried in and placed by the wafer transfer mechanism 3 according to the notch n formed on its outer periphery.

The role of the chucking table 5 is to vacuum-suction the wafer W transferred from the wafer transfer mechanism 3 and placed in a posture aligned with a predetermined position. As shown in FIG. 2 , a cutter head running groove 13 is formed on the top of the holder 5 , and the function of the cutter head running groove 13 is to make the cutter head 12 equipped on the tape cutting mechanism 9 described later follow the shape of the wafer W. Rotating movement is performed to cut the protective tape T.

Returning to FIG. 1, the structure of the tape supply unit 6 is to guide and wind the protective tape T with the separation layer pulled out from the supply winding frame 14 on the guide roller 15, and the protective tape T after the separation layer s is peeled off. Guide to the attachment unit 8. Moderate rotational resistance is applied to the supply winding frame 14, and the tape is not allowed to be pulled out excessively.

The separation layer recovery unit 7 drives the recovery winding frame 16 on which the separation layer s peeled off from the protective tape T is wound to rotate in the winding direction.

As shown in FIG. 6 , a horizontally forward attaching roller 17 is provided in the attaching unit 8 , and horizontal reciprocating drive is performed left and right by a sliding guide mechanism 18 and a screw-feeding drive mechanism not shown.

The peeling unit 10 is provided with a horizontally forward peeling roller 19 , which is horizontally reciprocated left and right by a slide guide mechanism 18 and a screw feed type drive mechanism not shown.

The tape recovery unit 11 drives the recovery winding frame 20 on which the unnecessary tape T' is wound to rotate in the winding direction.

As shown in Figure 1, the tape cutting mechanism 9 is basically at the lower part of the movable table 21 that can be driven up and down, and a pair of support arms 22 that can be driven and rotated are equipped side by side along the longitudinal axis X at the center of the clamping table 5. . On the tool unit 23 provided on the upstream end side of the support arm 22, the tool head 12 with the knife point downward is installed. By rotating the support arm 22 around the longitudinal axis X, the tool head 12 moves along the Walk around the periphery and cut the protective band T. Its detailed structure is shown in Figure 2 to Figure 6 .

As shown in FIG. 2 , by driving the motor 24 in forward and reverse rotation, the movable table 21 is lifted and lowered along the longitudinal guide rail 25 in a thread-feeding manner. The rotating shaft 26 rotatably equipped on the upstream end of the movable table 21 along the longitudinal axis X is decelerated and linked with the motor 27 provided on the movable table 21 through two belts 28. 27 rotates the rotating shaft 26 in a predetermined direction at a low speed. At the lower end of the support member 29 extending downward from the rotating shaft 26, the support arm 22 that can be slid and adjusted in the horizontal direction is penetrated and supported. Through the sliding adjustment of the support arm 22, the adjustment of the position of the cutter head 12 can be changed according to the diameter of the wafer. The distance from the longitudinal axis X, that is, the radius of rotation of the cutter head 12 .

Rotary shaft 26, motor 27 and belt 28 have constituted cutter head traveling device and the 1st driving device of the present invention. Moreover, the support arm 22 corresponds to the adjustment means of this invention.

As shown in FIG. 3 , a bracket 30 is fixed to the upstream end of the support arm 22 . The cutter unit 23 is mounted and supported on the bracket 30 . The tool unit 23 includes: a rotating member 31 rotatably supported on the bracket 30 within a certain small range along the longitudinal axis Y; ; the tool support member 33 connected to the side surface of the support bracket 32 ; the bracket 34 supported on the tool support member 33 ; the tool holder 35 mounted on the bracket 34 , and the like. The cutter head 12 is threadedly connected to the side of the cutter holder 35 .

As shown in FIG. 4 , above the rotating member 31 , there is provided an operation flange 38 that rotates integrally with the rotating member 31 by engaging the elongated hole 36 with the projection 37 . The operating flange 38 is rotated by the air cylinder 39 to change the overall posture of the cutter unit 23 relative to the support arm 22 around the longitudinal axis Y, and adjust the angle of the cutter head 12 relative to the traveling direction within a specified small range.

With respect to the tool support member 33, the bracket 34 is slidably supported in the longitudinal direction of the support arm 22 (the front and back direction of the drawing in FIG. Apply sliding force.

The tool holder 35 is supported on the bracket 34 and can rotate around the longitudinal axis Z passing through the back edge of the cutter head 12. At the same time, the spring 41 is used to apply a rotational force close to the longitudinal axis X to the tip of the cutter head 12. . In addition, the spring 41 corresponds to the elastic body of this invention. The elastic body is not limited to a spring, and for example, a resinous belt or rubber may be used.

The bracket 30 rotatably supporting the cutter unit 23 is equivalent to the supporting device of the present invention, and the rotating member 31, the elongated hole 36, the protrusion 37, the cylinder 39 and the spring 41 constitute the cutter head autorotation device of the present invention.

Next, a series of basic operations for attaching the protective tape T to the surface of the wafer W using the apparatus of the above embodiment will be described with reference to FIGS. 6 to 9 .

Once the sticking command is issued, first, the robot arm 2 of the wafer transfer mechanism 3 moves to the cassette C placed and loaded in the wafer supply/recovery section 1, and the wafer holding section 2a is inserted into the cassette C. in the gap between the wafers. The robot arm 2 sucks and holds the wafer W from the back surface (lower surface) through the wafer holding unit 2 a and carries it out, and transfers the taken-out wafer W onto the reference stage 4 .

The wafer W placed on the reference table 4 is aligned using the notches n formed on the outer periphery of the wafer W. As shown in FIG. The aligned wafer W is carried out again by the robot arm 2 and placed on the chuck 5 .

The wafer W placed on the chuck 5 is sucked and held, and its center is aligned with the center of the chuck 5 . At this time, as shown in FIG. 6 , the sticking unit 8 and the peeling unit 10 are in the initial position on the left and are on standby, while the cutter head 12 of the tape cutting mechanism 9 is on the initial position on the upper side.

As shown by the imaginary line in FIG. 6, the attaching roller 17 of the attaching unit 8 descends, and, while the protective tape T is pressed downward by the attaching roller 17, it moves forward on the wafer W (Fig. (right) is rotated, thereby attaching the protective tape T to the entire surface of the wafer W.

As shown in FIG. 7 , when the attaching unit 8 reaches the terminal position, the cutter head 12 that is waiting above descends, and pierces the protective tape T in the cutter head running groove 13 of the clamping platform 5 .

As shown in FIG. 8, when the cutter head 12 descends to the specified cutting height position and stops, the support arm 22 turns in the specified direction, and the cutter head 12 rotates and moves around the longitudinal axis X accordingly, moving along the shape of the wafer. The protective tape T is cut off.

When the cutting of the tape along the outer periphery of the wafer W is completed, as shown in FIG. The remaining useless tape T' is rolled up and peeled off.

When the peeling unit 10 reaches the end position of the peeling operation, the peeling unit 10 and the sticking unit 8 move in reverse and return to the initial position. At this time, while the unnecessary tape T' is wound on the recovery winding frame 20, a certain amount of protective tape T is pulled out from the tape supply unit 6. As shown in FIG.

Once the tape attaching operation is completed, the attached wafer W is transferred to the wafer holding part 2a of the robot arm 2 after the suction on the clamp table 5 is released, and inserted into the wafer supply/recovery part. 1 box C and be recovered.

The above is the end of one tape sticking process, and the above operations are sequentially repeated thereafter.

In the tape cutting step in the protective tape attaching step described above, the tape cutting at the notch n formed on the outer periphery of the wafer W is performed as follows. In addition, the notch n is concavely bent to have an opening width of 4 to 5 mm in the circumferential direction and a depth of about 3 mm.

During the advancement of the cutter head 12 on the peripheral portion other than the notch n of the wafer W, as shown in FIG. The cut-in slope angle slides in the circumferential direction. When the bit 12 reaches the end of the upper side of the notch n, the rod of the air cylinder 39 shrinks, whereby the bit 12 becomes inwardly rotatable. As shown in Fig. 10(b), the cutter head 12 detached from the outer peripheral edge of the wafer W advances while rotating by the elastic force in the direction of the center of rotation of the cutter head, and the cutter head bites into the notch n and continues to advance. . When the tip of the tool reaches the vicinity of the bottom of the notch n, the rod of the air cylinder 39 is extended again while the tip of the tool 12 advances, whereby the tip of the tool 12 rotates in the opposite direction and moves to the outer periphery of the wafer (refer to FIG. 10 (c) ). Once the bit 12 reaches the end of the lower side of the notch n, thereafter, as shown in FIG. 10( d ), the bit 12 advances along the outer periphery of the wafer W again.

In this way, by the rotation of the cutter head 12, it bites into the notch n and moves, and reversely rotates in the second half of the notch n, the protective tape T in the notch n is dug out, and the remaining part of the notch n is cut. Residual band t is rare.

The present invention can also be implemented in the following forms.

(1) An actuator such as a pulse motor may be used to drive the tool holder 35 to rotate. In this case, by controlling the cutter head 12 to move while rotating along the inner edge of the notch n according to a program input in advance, the residual tape t in the notch n can be further reduced.

(2) The method of the present invention can also be implemented in a state where the wafer W is rotated relative to the cutter head 12 to cut the tape. To realize this configuration, it is only necessary to rotate the chuck 5 that absorbs and holds the wafer W by a driving device such as a motor, for example. In the case of this configuration, the motor corresponds to the second driving device of the present invention.

The present invention can be implemented in other specific forms without departing from the idea or essence thereof. Therefore, the appended claims should be referred to in addition to the above description to show the scope of the invention.

Claims (10)

1. a method for cutting off a protective tape of a semiconductor wafer, the cutter head is relatively walked along the periphery of the semiconductor wafer, and the protective tape attached to the surface of the semiconductor wafer is cut along the wafer profile, and the above-mentioned method comprises the following process, characterized in that, A tool head running process in which the tool heads move relative to each other along the outer periphery of the semiconductor wafer having positioning notches on the outer periphery; During the running process of the cutter head, the first half of the cutter head is made to rotate by itself in the first half of the notch formed on the outer periphery of the wafer so that the cutter head faces the center of the wafer; In the second half of the notch, the cutter head is rotated by itself so that the tip of the cutter faces the outer periphery of the wafer during the second rotation. 2 . The method according to claim 1 , wherein, in the tool head running process, the tool head is made to run along the outer periphery of the semiconductor wafer. 3 . 3. The method of claim 1, wherein, During the moving process of the cutter head, the cutter head is fixed, and the semiconductor wafer is rotated around the central axis, In the first rotation process and the second rotation process, the tool head is rotated around an axis near the back edge of the tool head while the semiconductor wafer is rotated. 4. The method according to claim 1, further comprising the step of changing the radius of rotation of the cutter head. 5. The method according to claim 1, characterized in that, during the traveling process of the cutter head, the first rotation process and the second rotation rotation process, the tip of the cutter head is given elastic force to bring it closer to the central axis of the semiconductor wafer. 6. A protective tape cutting device for a semiconductor wafer, which makes the cutter head run relatively along the periphery of the semiconductor wafer, and cuts the protective tape attached to the surface of the semiconductor wafer along the wafer profile, it is characterized in that the The device includes the following elements: A supporting device that is parallel to the axis passing through the center of the wafer, centered on the axis near the back edge of the cutter head, and rotatably supports the cutter head; A tool head traveling device for relatively moving the tool head along the outer periphery of the semiconductor wafer having positioning notches on the outer periphery; Rotate the tool head so that its tip faces the center of the wafer in the first half of the notch recessed and formed on the outer periphery of the wafer, and turn the tool tip so that its tip faces the wafer in the second half of the notch The cutter head on the outer periphery rotates automatically. 7 . The device according to claim 6 , wherein the tool head traveling device is a first driving device for rotating the tool head around the semiconductor wafer. 8 . 8. The device according to claim 6, wherein the cutter head traveling device comprises: holding means for holding said semiconductor wafer; A second driving device for rotating the holding device around the central axis of the semiconductor wafer held by the holding device. 9. The device according to claim 6, characterized in that the device further comprises the following elements, namely an adjustment device for adjusting the radius of rotation of the cutter head. 10. The device according to claim 6, further comprising the following element, that is, an elastic force is applied to the tip of the cutter head so that it approaches the central axis of the semiconductor wafer. elastomer.

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