JP2009044008A5 - - Google Patents

Description

Wafer protective tape peeling device

The present invention relates to peeling HanareSo location of the protective tape of the wafer. More particularly, leaving a peripheral portion of the wafer, the inner peripheral portion of the wafer back surface is about peeling HanareSo place the protective tape from the surface of concave wafer is ground.

  Due to recent demands for miniaturization of portable devices, the thickness of wafers has been reduced to less than 100 μm, and those having a thickness of 50 μm or less have been used.

  Conventionally, the thinned wafer as described above is mounted on the dicing frame through the dicing tape in a state of being attached to the protective tape, and then the protective tape is peeled off. The detached wafer was not handled alone.

  However, in a wafer for a single-function semiconductor (discrete) such as a diode or a transistor, a metal thin film is formed on the back surface of the wafer by metal vapor deposition or the like in order to form electrodes on the back surface. In order to form a metal thin film on the back surface of the wafer in this way, it is necessary to process at a high temperature such as sputtering or vapor deposition, and the protective tape attached to the front surface side cannot withstand the processing temperature, so it must be peeled off. is there. Further, even when the treatment is performed at a low temperature, the protective tape is peeled off before the treatment such as vapor deposition from the side where impurities such as an adhesive used for the protective tape are mixed.

  However, the wafer as described above has to be handled as a single wafer with the protective tape peeled off, and it has become very difficult to handle due to problems such as warpage, chipping and breakage of the wafer. In addition, even if a wafer other than a discrete wafer that is not subjected to metal vapor deposition or the like on the back surface is thinned as described above, even if a protective tape is applied, chipping may occur in the outer peripheral portion of the wafer during transportation. There is a problem of warping.

  Accordingly, in order to prevent the wafer from warping and chipping and to facilitate handling, a concave wafer is also produced in which the outer peripheral portion of the wafer is left and the inner peripheral portion of the back surface of the wafer is ground (for example, Patent Document 1).

  According to this method, the outer peripheral portion of the wafer is configured to be thicker than the inner peripheral portion, so that chipping of the outer peripheral portion and warpage of the wafer can be prevented and handling is easy.

  The above method is performed as shown in FIG. 9, for example. First, a wafer 1 having a circuit pattern formed on the surface is prepared (FIG. 9A).

  Subsequently, the protective tape 2 is attached to the surface of the wafer 1 (FIG. 9B).

The inner peripheral portion is ground to a predetermined thickness, leaving the outer periphery Li blanking on the rear surface of the protective tape 2 is pasted wafer 1 on the surface (FIG. 9 (c)).

The protective tape is peeled off from the surface of the concave wafer 1 whose inner periphery is ground (FIG. 9D).
Next, a metal film 57 is formed on the back surface of the wafer by vapor deposition or sputtering (FIG. 9E).

  The surface protection tape 2 is again attached to the surface of the wafer 1 on which the metal film 57 has been formed (FIG. 9F).

Then periphery Li blanking of the wafer 1 is planarized is ground or cut (FIG. 9 (g)).

  The planarized wafer 1 is mounted on a dicing frame 59 via a dicing tape 58 (FIG. 9 (h)). The surface of the mounted wafer 1 is peeled off and subjected to a dicing process.

JP-A-5-121384

  As described above, at least in the case of a discrete wafer, when performing sputtering or vapor deposition on the back surface of the concave wafer, it becomes a high temperature state, so it is necessary to peel off the protective tape attached to the front surface. In addition, even when processing at a low temperature, it is necessary to peel off the protective tape in order to prevent contamination of impurities due to volatile components.

However, the conventional protective tape peeling device has a flat suction table that supports and supports the wafer. When the concave surface (wafer back surface) of the concave wafer is attracted to the suction table, the outer peripheral rib surface and the concave surface Adsorption is insufficient due to the difference in level, the wafer loses adsorption when the protective tape is peeled together with the release tape, and the wafer is lifted, or the center of the wafer is bent when the release tape is attached to the protective tape with a sticking roller, There is a problem that a load is applied to the stepped portion and the wafer is damaged.

Also, if you choose to support only the inner peripheral portion of the wafer, there is a problem of wafer periphery Li Bed unsupported by the pressing of the joining roller such as when joining the peeling tape to the protective tape on the wafer is damaged bent.

Further, there is a case where the grinding of the inner peripheral portion of the wafer ways differs by processing of the subsequent wafer outer peripheral re blanking thickness, there is a case where widths are different. Therefore, it is necessary to change the suction table every time, but there is a problem that it takes time to replace the table and the cost is high.

Furthermore, when peeling integrally pasted the peeling tape to the protective tape on the wafer, the Failure to closely support the wafer peeling start portion adsorption of the wafer or lost the peel force by peeling tape, sticking the peeling tape There is a case where the wafer is damaged due to a load applied to the wafer by the pressing of time.

Further, when the protective tape on the wafer by the peeling tape pasted peeled together, unless reduce upward force to the wafer at least peeling start portion, the wafer raised to the upper direction losing the adsorption, the wafer There is a problem that breaks.

In order to solve the above problems, the invention of claim 1 is a wafer in which the back surface is formed in a concave shape by providing an outer peripheral rib whose outer periphery is thicker than its inner peripheral part, and is attached to the surface of the wafer. In the protective tape peeling apparatus in which the attached protective tape is peeled off integrally with the peeling tape, a convex portion that fits into the concave portion of the wafer and a mounting surface that supports the entire outer peripheral rib surface on the outer periphery thereof are provided. The holding table is a wafer protective tape peeling apparatus that holds the concave surface of the wafer by the convex portion and holds the outer peripheral rib of the wafer by the mounting surface .

According to a second aspect of the present invention, the holding table is provided separately and independently in an inner peripheral table that fits into the concave portion of the wafer and an outer peripheral table that holds the outer peripheral rib surface of the wafer. Either one of the outer peripheral tables is configured to be movable up and down with respect to the other table, and the height difference between the inner peripheral table and the outer peripheral table is matched with the height difference between the concave surface of the wafer and the outer peripheral rib surface to hold the wafer. The apparatus for peeling off a wafer protective tape according to claim 1 .

Further, the invention of claim 3 is configured such that the outer diameter of the inner peripheral table is slightly smaller than the diameter of the concave surface of the wafer, and the inner peripheral table and the outer peripheral table are integrally movable.
The wafer is held in a state in which the holding table is horizontally moved so that the inner peripheral surface of the outer peripheral rib of the wafer and the outer peripheral surface of the inner peripheral table are in contact with each other on the peeling start end side of the protective tape. 2. The wafer protective tape peeling apparatus according to 2.

According to the present invention, the inner peripheral table and the outer peripheral table can be moved up and down, and the wafer can be placed so as to absorb the height difference between the concave surface of the wafer and the outer peripheral rib surface. Even if the wafer is pressed when the protective tape is peeled off, the wafer is not damaged.

Further, if the concave surface of the wafer and the outer peripheral rib surface can be sucked, the wafer will not be lifted and damaged when the protective tape is peeled off with the peeling tape.

Moreover, never wafer is damaged bent even by pressing the outer peripheral re blanking of the wafer so adapted to support a periphery Li blanking.

In addition, since the outer peripheral table is configured to be movable up and down with respect to the inner peripheral table, and the inner peripheral table and the outer peripheral table are configured to be horizontally movable integrally, the concave surface of the wafer and the outer peripheral rib surface can be supported flatly. , even inside diameter and position of the concave surface of the wafer is changed, Runode be tightly supporting the peeling start portion, it is not damaged not applied load on the wafer when the protective tape peeling.

Also, if the inner peripheral table and the outer peripheral table are integrally formed and the mounting surface of the outer peripheral table is positioned below the mounting surface of the inner peripheral table by a height difference between the concave surface of the wafer and the outer peripheral rib surface. The table configuration can be simplified and the cost can be reduced.

  Also, if a protective roller is provided to hold down the protective tape at the peeling start end when the protective tape is peeled off, and the protective tape is peeled off while maintaining the state where the protective tape is folded at an acute angle, the upward force is applied to the wafer. Therefore, the wafer is not damaged.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a front view of a peeling device 3 in which a part of the present invention is cut away. A machine frame 4 is erected on the machine base 5, and a peeling unit 28 for peeling the protective tape 2 attached to the wafer 1 is provided on the upper left of the machine frame 4. Further, a protective tape 2 to be peeled is pressed on the right side of the peeling unit 28, and a pressing roller 36 for peeling the protective tape 2 at an acute angle is disposed, and the concave wafer 1 is flatly supported on the center of the machine base 5. An inner peripheral table 6 and an outer peripheral table 8 are provided.

As shown in FIGS. 1 and 2, the inner peripheral table 6 is formed in a circular shape, and the concave surface of the wafer 1 whose inner peripheral portion is ground to a predetermined thickness while leaving the outer periphery of the back surface is formed of a porous member. The outer peripheral table 8 having an opening 40 is provided on the outer periphery of the inner peripheral table 6, and the outer peripheral rib surface 50 of the wafer 1 is adsorbed and supported by the plurality of adsorbing portions 9. It is like that.

The suction unit 7 and the suction unit 9 are connected to independent suction lines (not shown), and support the concave surface and the outer peripheral rib surface 50 of the wafer 1 placed thereon.

  The inner peripheral table 6 is erected and fixed on a table 16, and the outer peripheral table 8 is provided with guides 14 provided on both left and right side surfaces and rails 13 provided on support frames 15 erected on the left and right sides of the outer peripheral table 8. It can be fitted and slid up and down.

  A nut member 19 is provided on the right side surface of the outer peripheral table 8, and the nut member 19 screwed into the ball screw 18 is driven up and down by driving a motor 17 provided at the lower right of the table base 16. The table 8 moves up and down on the table base 16 along the rail 13.

Wherein the lower surface of the table top 16 guide 23 is fixed, it is fitted freely rail 22 and a slide which is laid on the machine base 5, screw and ball screw 2 4 by driving the ball screw 2 4 by the motor 21 The combined nut member 25 is driven, and the inner peripheral table 6 and the outer peripheral table 8 fixed to the nut member 25 are horizontally moved integrally.

  The peeling unit 28 wraps the peeling tape 12 supplied from the peeling tape supply reel 10 to the guide roller 27, and is wound around the peeling tape take-up reel 11 through the sticking roller 31, the guide roller 43, and the driving roller 26. It has become.

  Further, the peeling unit 28 can be horizontally moved by an appropriate driving source (not shown) through the support frame 45 along the rail 39 provided on the machine casing 4, and further by appropriate means (not shown). Can be moved up and down.

A heater 29 that can be moved up and down by a cylinder 30 is provided behind the sticking roller 31 of the peeling unit 28, and the peeling unit 28 acts on the wafer 1 as shown by the two-dot chain line in FIGS. After the release tape 12 is affixed onto the protective tape 2, the heater 29 is lowered to the start of peeling at the outer peripheral end of the wafer 1, and the release tape 12 is thermocompression bonded to the protective tape 2.

  Further, a folding roller 33 is provided in front of the sticking roller 31 of the peeling unit 28 via a spring 32 so that an appropriate pressing force is urged, and when the peeling unit 28 moves backward with the peeling of the protective tape 2. The release tape 12 and the peeled protective tape 2 are pressed and folded back in the 180 ° direction.

To the right of the peeling unit 28, and the pressing roller 36 of the wafer 1 and the protection tape 2 to prevent a force in the upward direction to the wafer 1 is provided upon the release of the protective tape 2 at a peeling starting, rails It can be moved up and down by a suitable drive source (not shown) through a guide 34 fitted to 35.

    The presser roller 36 is movable on the inner peripheral table 6 and the outer peripheral table 8 along a rail 37 extending to the machine frame 4 via a support frame 38.

    Next, a method for placing the wafer on the table of the protective tape peeling apparatus of the present invention will be described with reference to FIGS. It is emphasized for easy understanding.

    The wafer 1 positioned by an appropriate alignment device (not shown) as shown in FIG. 3A is transferred onto the inner peripheral table 6 by a transfer body (not shown) such as an appropriate suction hand. Yes.

The inner peripheral table 6 is formed to be equal to or smaller than the diameter of the concave surface of the wafer 1, and is located above the inner peripheral table 6 so that the center (dashed line) of the inner peripheral table 6 and the center of the wafer 1 (dashed line) coincide. Carry.

By matching centers of inner peripheral table 6 and the wafer 1 as described above, a state in which the distance between the outer peripheral rib inside surface 51 of the inner circumferential table outer peripheral surface 52 and the wafer 1 in the stripping start end spaced apart by x.

Also, the wafer 1 is the difference in thickness between the concave surface and the outer peripheral rib surface 50 is only d, whereas, the outer peripheral table 8 is located at the lower end in the initial state, allowed to positioned below at least the thickness difference d or more (this Thus, even if the wafer 1 is attracted to the inner peripheral table 6, no load is applied to the wafer 1).

If the thickness of the wafer 1 is formed to 750 μm, for example, and the thickness of the concave surface is ground to 50 μm, the thickness difference d becomes 700 μm.

Further, the center of the wafer 1 can be detected by the alignment apparatus from the orientation flat portion 54 or the notch of the wafer 1, and the thickness difference between the concave surface of the wafer 1 and the outer peripheral rib surface 50 is detected in advance by an appropriate depth sensor or the like. Just do it.

By then the motor 21 be only horizontal motion x to the right of the inner circumference table 6 and the outer peripheral table 8 together by driving (see FIG. 1), the inner circumference and the outer peripheral rib inside surface 51 of the wafer 1 at a peeling start The table outer peripheral surface 52 is made to coincide.

    Subsequently, the motor 17 (see FIG. 1) is driven to raise the outer peripheral table 8 so that the difference in height between the mounting surface of the inner peripheral table 6 and the mounting surface of the outer peripheral table 8 becomes d. By driving the table, the inner peripheral table 6 and the outer peripheral table 8 are positioned as indicated by a two-dot chain line in FIG.

As shown in FIG. 3B, the wafer 1 is lowered to the position indicated by a two-dot chain line, whereby the wafer 1 is placed on the inner peripheral table 6 and its concave surface is attracted to the inner peripheral table 6 and the outer peripheral rib surface. 50 is placed on the outer peripheral table 8 and supported by suction, and the wafer 1 is supported flat.

    Next, a method of peeling the protective tape 2 from the wafer 1 supported by the inner peripheral table 6 and the outer peripheral table 8 will be described with reference to FIGS. 4 (a) to 5 (f).

    As shown in FIG. 4A, the wafer 1 with the protective tape 2 attached to the surface is supported flat on the inner peripheral table 6 and the outer peripheral table 8, and the peeling unit 28 is located at the upper left upper position of the outer peripheral table 8. Waiting.

    The peeling unit 28 advances to the vicinity of the center of the inner peripheral table 6 and descends, and the peeling tape 12 is applied onto the surface protection tape 2 of the wafer 1 by the action of the application roller 31 as shown by a two-dot chain line in FIG. Paste from the center of 1 toward the outer periphery. At this time, the application roller 31 moves forward until the heater 29 is positioned at the outer peripheral edge of the wafer 1 in preparation for the next thermocompression bonding.

After the release tape 12 is attached to the protective tape 2 of the wafer 1 as shown in FIG. 4B, the heater 29 positioned on the outer peripheral edge of the wafer 1 is lowered by the action of the cylinder 30 and peels off from the protective tape 2. The tape 12 is thermocompression bonded.

After peeling start portion of the outer peripheral edge of the wafer 1 as shown in FIG. 4 (c) is thermocompression, the separation unit 28 is retracted. At this time, since the peeling tape 12 is appropriately pressed by the folding roller 33 in front of the sticking roller 33, the peeling tape 12 is folded in the 180 ° direction.

After peeling unit 28 is folded is release tape 12 backward, the pressing roller 36 on a release starting end of the wafer 1 an outer peripheral end is advanced along the rails 37 by a suitable drive source (not shown).

The degree of pressing rollers 36 which advance the descends along the rail 35 by a suitable drive source (not shown), contact the folded separation tape 12 on to maintain the folded state of the release tape 12 folded in peel starting end Alternatively, a gap (about 1-2 mm) is maintained.

    The gap is not limited to the above, and may be adjusted according to the thickness of the peeling tape 12 or the protective tape 2 to be peeled.

    Subsequently, as shown in FIG. 5D, the protective tape 2 is peeled integrally with the peeling tape 12 by the backward movement of the peeling unit 28 and the advance of the pressing roller 36.

The peeling unit 28 may be retracted while maintaining the above state to the end portion of the wafer 1. However, when the diameter of the concave surface of the wafer 1 is larger than the inner peripheral table 6, the peeling end of the wafer 1 is removed. Since a part is not supported by the inner peripheral table 6, it is preferable that the peeling unit 28 is raised at the peeling end part as shown in FIG.

By doing so, the load generated on the wafer 1 at the separation end portion of the wafer 1 can be reduced, and the wafer 1 is hardly damaged.

    As shown in FIG. 5F, the pressing roller 36 moves following the peeling unit 28 until the protective tape 2 is peeled to the peeling end portion of the wafer 1, and the peeling of the protective tape 2 is completed.

Although in the present embodiment, as pressed by the roller 36 pressing the folded portion of the peeling tape 12 may also be pressed by the plate-like member in place of the roller, also as pressing only peel starting end at the start of peeling Also good.

Next, another embodiment of the wafer 1 in which the diameter of the concave surface of the wafer 1 is changed will be described with reference to FIGS.

FIG. 6A shows a case where the diameter of the concave surface of the wafer 1 is substantially the same as or slightly smaller than the diameter of the inner peripheral table 6. In this case, the center of the concave surface and the inner peripheral table 6 The wafer 1 may be positioned and placed on the inner peripheral table 6 with the center aligned and supported by suction.

6 (b) is greater than the diameter of the inner circumferential table 6 diameter of the concave surface of the wafer 1 represents a case in which reaches the orientation flat portion 54, the outer peripheral rib inside surface 51 of the case, peel starting end of the wafer 1 The inner peripheral table 6 and the outer peripheral table 8 are driven so as to contact the outer peripheral surface 52 of the inner peripheral table, or the wafer 1 positioned by an appropriate means (not shown) may be placed on the inner peripheral table 6. .

    In this case, since the support at the outer peripheral table 8 at the peeling end portion of the wafer 1 is weakened, it is preferable that the peeling unit 28 be lifted and peeled off at the peeling end portion of the peeling tape 12.

    Next, a second embodiment will be described with reference to FIG.

In this embodiment, the inner peripheral table 6 and the outer peripheral table 8 are integrally formed, and the height of the inner peripheral table 6 is set to the height of the mounting surface of the outer peripheral table 8 by the thickness difference between the concave surface of the wafer 1 and the outer peripheral rib surface. The configuration is lowered.

    In this case, it is effective mainly when the inner peripheral grinding conditions of the wafer 1 are fixed, and it is not necessary to drive the table, so that the cost can be reduced.

FIG. 8 shows the third embodiment, and is an enlarged cross-sectional view of a main part when a chamfered portion 56 is provided in the concave portion of the wafer 1.

In the case of the present embodiment, if the inner peripheral table 6 as in the first embodiment is used, the concave surface of the wafer 1 and the inner peripheral table 6 cannot be brought into close contact with the chamfered portion 56. Is chamfered to match the shape of the chamfered portion 56.

Depending on the shape of the concave portion of the wafer 1 as described above, by changing the appropriate configuration, the shape of the concave portion of the wafer 1 at least peel starting end, may damage the wafer 1, combined with the shape of the inner circumferential table 6 Can be prevented.

The front view of the protective tape peeling apparatus showing one Embodiment of this invention The top view of the protective tape peeling part of this invention (A) thru | or (b) Explanatory drawing of the mounting method of the wafer to the table showing the 1st Embodiment of this invention. (A) thru | or (c) explanatory drawing showing peeling operation | movement of this invention (D) thru | or ( f ) explanatory drawing showing peeling operation | movement of this invention (A), (b) Explanatory drawing showing the grinding state of another wafer of the present invention Explanatory drawing showing the 2nd Embodiment of this invention. The principal part expansion explanatory drawing showing the 3rd Embodiment of this invention (A) thru | or (h) Explanatory drawing of a wafer processing process

DESCRIPTION OF SYMBOLS 1 Wafer 2 Protective tape 3 Protective tape peeling apparatus 4 Machine frame 5 Machine stand 6 Inner peripheral table 7 Adsorbent body 8 Outer peripheral table 9 Adsorbing part 10 Release tape supply reel 11 Release tape collection reel 12 Release tape 13 Rail 14 Guide 15 Support frame 16 Table base 17 Motor 18 Ball screw 19 Nut member 21 Motor 22 Rail 23 Guide 24 Ball screw 25 Nut member 26 Drive roller 27 Guide roller 28 Peeling unit 29 Heater 30 Cylinder 31 Sticking roller 32 Spring 33 Folding roller 34 Guide 35 Rail 36 Pressing roller 37 Rail 38 support frame 39 rail 40 opening 43 guide roller 45 support frame 50 outer peripheral rib surface 51 outer peripheral rib inner surface 52 inner peripheral table outer peripheral surface 53 circuit pattern 54 orientation flat portion 56 chamfered portion 57 metal film 58 dicing tape 9 dicing frame

Claims (3)

A wafer in which the outer periphery of the back surface is formed thicker than the inner peripheral portion to provide a concave surface on the back surface, and the protective tape attached to the surface of the wafer is peeled off integrally with the peeling tape. In the protective tape peeling device,
A holding table having a convex portion that fits into the concave portion of the wafer and a mounting surface that supports the entire outer peripheral rib surface on the outer periphery thereof;
An apparatus for peeling off a protective tape for a wafer, wherein the holding table holds the concave surface of the wafer by the convex portion and holds the outer peripheral rib of the wafer by the mounting surface. The holding table is provided separately and independently into an inner peripheral table that fits into the concave portion of the wafer and an outer peripheral table that holds the outer peripheral rib surface of the wafer,
One of the inner and outer peripheral tables is configured to be movable up and down with respect to the other table,
2. The wafer protective tape peeling apparatus according to claim 1, wherein the wafer is held by making the height difference between the inner peripheral table and the outer peripheral table coincide with the height difference between the concave surface of the wafer and the outer peripheral rib surface. . The outer diameter of the inner peripheral table is formed to be slightly smaller than the diameter of the concave surface of the wafer, and the inner peripheral table and the outer peripheral table are configured to be horizontally movable integrally.
The holding table is moved horizontally, and the wafer is held in a state in which the outer peripheral rib inner peripheral surface of the wafer positioned on the peeling start end side of the protective tape and the inner peripheral table outer peripheral surface are in contact with each other. The apparatus for peeling off a protective tape for a wafer according to claim 1 or 2.