JP2020096045A - Workpiece processing method - Google Patents

Abstract

To provide a workpiece processing method capable of processing a workpiece without fixing a resin sheet to the workpiece with a paste made of a resin having adhesiveness.SOLUTION: A workpiece processing method includes the steps of: sticking a paste layer side of a resin sheet 21 having a laminate structure in which a paste layer and a base material layer are formed to an annular frame 29 so as to cover an opening of the annular frame in a grinding device 70; forming an unevenness on a surface side of the base material layer on an opposite side of the paste layer; supplying a liquid to a surface side of the base material layer in which the unevenness is formed or a surface side of a workpiece 11; facing the surface of the workpiece and the surface of the base material layer to each other, pressing the workpiece to the resin sheet via the liquid or pressing the resin sheet to the workpiece via the liquid, and fixing the workpiece to the resin sheet in close contact with each other; holding the surface side of the workpiece fixed to the resin sheet; and grinding a rear surface side of the workpiece with a grinding stone 84b of a grinding wheel 84 provided facing a holding surface.SELECTED DRAWING: Figure 11

Description

The present invention relates to a processing method for processing a work piece fixed to an annular frame via a resin sheet.

In the process of processing wafers made of semiconductor materials, etc., a resin sheet that protects the devices formed on the front surface of the wafer is attached to the front surface of the wafer, and then the front surface of the wafer is suction-held with a chuck table. It is known to grind (process) the back surface side of a wafer (see, for example, Patent Document 1).

For example, prior to this grinding, the front surface side of the wafer in which the device is provided on the front surface side of each region divided by a plurality of planned dividing lines (streets) is cut along the planned dividing line and does not reach the back surface. A cutting groove having a predetermined depth is formed. Then, the back surface side of the wafer is ground until it reaches the cutting groove.

JP, 2003-209080, A

The resin sheet is usually formed in a laminated structure of a base material layer and a glue layer, and the glue layer adheres to the surface of the wafer to fix the resin sheet to the wafer. However, when the resin sheet is peeled off from the wafer, there is a problem that the adhesive agent remains on the front surface side of the wafer (so-called adhesive residue occurs).

In particular, for wafers with bumps formed on the front surface or for wafers that are divided into small chips, the resin sheet must be firmly fixed to the wafer, so a glue with strong adhesiveness is used for the glue layer. It Therefore, the sizing agent is likely to remain on the front surface side of the wafer.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a processing method for processing a workpiece without fixing a resin sheet to the workpiece with a sizing agent made of an adhesive resin. And

According to one aspect of the present invention, there is provided a method for processing a work piece, comprising grinding a back surface side of the work piece having a device formed on a front surface side thereof until a work piece has a predetermined finished thickness. A step of attaching the adhesive layer side of the resin sheet having a laminated structure of an adhesive layer and a base material layer to the annular frame so as to cover the opening of the annular frame having a portion; Before or after, the unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the glue layer, and the base material having the unevenness formed after the attaching step and the unevenness forming step A liquid supplying step of supplying a liquid to the surface side of the layer or the surface side of the work piece, and facing the surface of the work piece and the surface of the base material layer through the liquid A workpiece fixing step of pressing the workpiece against the resin sheet or pressing the resin sheet against the workpiece through the liquid, and closely fixing the workpiece to the resin sheet; A holding step of holding the front side of the workpiece fixed to the resin sheet by a holding surface of a rotatable chuck table, and a grinding wheel provided after the holding step and facing the holding surface. And a grinding step of grinding the back surface side of the work piece with the grinding wheel.

According to another aspect of the present invention, there is provided a method for processing a work piece, which comprises polishing a back surface side of the work piece having a device formed on a front surface side thereof, the method including covering the opening of an annular frame having an opening. And a step of attaching the adhesive layer side of the resin sheet having a laminated structure of an adhesive layer and a base material layer to the annular frame, and a step opposite to the adhesive layer before or after the attaching step. After the unevenness forming step of forming unevenness on the surface side of the base material layer, the attaching step and the unevenness forming step, the surface side of the base material layer on which the unevenness is formed or the work piece A liquid supplying step of supplying a liquid to the surface side, the surface of the workpiece and the surface of the substrate layer are opposed to each other, and the workpiece is pressed against the resin sheet through the liquid, or Workpiece fixing step of pressing the resin sheet to the work piece through the liquid to fix the work piece in close contact with the resin sheet; and the work piece fixed to the resin sheet. A holding step of holding the front surface side by a holding surface of a rotatable chuck table, and after the holding step, the back surface side of the workpiece is polished by a polishing pad provided facing the holding surface. And a polishing step for performing the method for processing a workpiece.

Preferably, the liquid is pure water.

In the processing method according to the aspect of the present invention, the glue layer of the resin sheet having the glue layer and the base material layer is attached to the annular frame. Then, irregularities are formed on the surface of the base material layer located on the side opposite to the glue layer, and a liquid is supplied to the irregularities. Then, the work piece is pressed against the resin sheet through the liquid, so that the work piece is brought into close contact with and fixed to the resin sheet. That is, since the sizing agent is not used to fix the resin sheet to the workpiece, the sizing agent does not remain on the workpiece even when the workpiece is peeled from the resin sheet.

It is a perspective view of a work piece. It is a perspective view of a resin sheet. It is a perspective view showing a pasting step. It is a partial cross section side view which shows an unevenness formation step. It is a perspective view showing an unevenness formation step. It is a perspective view showing the surface side of the resin sheet after the unevenness forming step. It is a perspective view showing a liquid supply step. It is a partial cross-sectional side view which shows a workpiece fixing step. 9A is a sectional view showing the holding step, and FIG. 9B is a perspective view showing the holding step. It is a partial cross section side view which shows a grinding step. It is a perspective view which shows a grinding step. It is a flowchart which shows the processing method of 1st Embodiment. It is a partial cross-sectional side view which shows a polishing step. It is a flowchart which shows the processing method of 2nd Embodiment. FIG. 15A is a perspective view showing a state in which a plurality of disc-shaped workpieces are fixed to a resin sheet, and FIG. 15B is a plan view showing a plurality of rectangular workpieces made of resin. It is a perspective view showing the state where it was fixed to the seat.

An embodiment according to an aspect of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a workpiece 11 used in this embodiment. The workpiece 11 is, for example, a disk-shaped wafer made mainly of a material such as silicon.

The surface 11a side of the workpiece 11 is divided into a plurality of areas by dividing lines (streets) 13 set in a grid pattern, and each area is provided with a device 15 such as an IC (Integrated Circuit). ing.

The workpiece 11 may be made of a semiconductor or an insulator other than silicon. Furthermore, there is no limitation on the shape, structure, size, etc. of the workpiece 11, and there is no limitation on the type, quantity, shape, structure, size, arrangement, etc. of the device 15.

FIG. 2 is a perspective view of the resin sheet 21 used in this embodiment. The resin sheet 21 is, for example, a circular film having a diameter larger than that of the workpiece 11. Further, the resin sheet 21 has a laminated structure of a base material layer 23 and a glue layer 25.

In the present embodiment, for convenience, one surface (front surface) of the base material layer 23 on the side opposite to the adhesive layer 25 is referred to as a surface 21 a of the resin sheet 21, and one surface of the adhesive layer 25 on the opposite side to the base material layer 23 is referred to as resin. It is referred to as the back surface 21b of the sheet 21. That is, the front surface 21 a is the outer surface of the resin sheet 21 on the base material layer 23 side, and the back surface 21 b is the outer surface of the resin sheet 21 on the glue layer 25 side.

The base material layer 23 is a circular film-shaped solid layer. The base material layer 23 has a predetermined thickness of, for example, 100 μm to 200 μm, and is made of a resin material such as polyolefin (PO), polyvinyl chloride (PVC), or polyethylene terephthalate (PET).

A glue layer 25 is provided in a ring shape in the vicinity of the outer periphery of the other surface of the base material layer 23 (that is, the surface opposite to the surface 21a) (see FIG. 3). The glue layer 25 is not limited to the annular shape, and may be provided on the entire other surface of the base material layer 23. However, in this case, a non-adhesive resin cover layer is further provided in a predetermined region (for example, a region corresponding to the opening 29c of the annular frame 29 described later).

The glue layer 25 is a layer made of a glue (that is, an adhesive), and is made of, for example, a material such as silicone rubber, acrylic resin, or epoxy resin. The glue layer 25 has a property that it loses its adhesiveness and is hardened by an external stimulus such as ultraviolet rays or heat.

Next, a method of processing the workpiece 11 will be described. In the processing method, first, the metal annular frame 29 is prepared. The annular frame 29 has an opening 29c, and the diameter of the opening 29c is larger than the diameter of the workpiece 11 and smaller than the diameter of the resin sheet 21.

Next, the back surface 21b of the resin sheet 21 is attached to the annular frame 29 so as to cover the opening 29c of the annular frame 29, and the resin sheet 21 and the annular frame 29 are integrated (attaching step (S10)). .. FIG. 3 is a perspective view showing the attaching step (S10).

In the present embodiment, for convenience, one surface of the annular frame 29 on which the resin sheet 21 is attached is referred to as a surface 29a of the annular frame 29, and the other surface of the annular frame 29 opposite to the surface 29a is the annular frame 29. Is referred to as the back surface 29b.

In the sticking step (S10), for example, a sticking device (not shown) is used to stick the annular glue layer 25 located on the back surface 21b side of the resin sheet 21 to the front surface 29a of the annular frame 29. The pasting device has a support table (not shown) that supports the annular frame 29.

The annular frame 29 is arranged on the support table such that the back surface 29b of the annular frame 29 contacts the surface of the support table. A moving mechanism (not shown) such as a ball screw is provided on the back surface side of the supporting table, and the supporting table can be moved in a predetermined direction by this moving mechanism.

A columnar pressure roller (not shown) that presses the resin sheet 21 toward the support table is arranged above the support table. Further, the direction of the rotation axis of the cylinder of the pressure roller is orthogonal to the above-mentioned predetermined direction which is the moving direction of the support table.

The sticking device has a sending-out mechanism (not shown) for sending a tape body (not shown) having a release sheet stuck to the adhesive layer 25 side of the resin sheet 21 toward a pressure roller. The pasting device further includes a peeling unit (not shown) that peels the resin sheet 21 from the release sheet when the resin sheet 21 is supplied between the pressure roller and the annular frame 29.

The release sheet peeled from the tape body by the peeling unit is wound by a winding mechanism (not shown). The speed at which the winding mechanism winds the release sheet and the speed at which the feeding mechanism feeds the tape body are adjusted to be the same.

In the attaching step (S10), first, the annular frame 29 is placed on the support table so that the surface 29a of the annular frame 29 faces upward. Next, the resin sheet 21 is arranged between the pressure roller and the annular frame 29 so that the surface on the side of the base material layer 23 contacts the pressure roller and the surface on the side of the glue layer 25 faces the support table.

Then, the resin sheet 21 is sent to the peeling unit by the feeding mechanism and the winding mechanism, and peeled from the release sheet by the peeling unit. After that, the resin sheet 21 is pressed (pressed) downward by the pressure roller and attached to a part of the annular frame 29 on the support table.

Next, the support table is moved in the above-described predetermined direction while the resin sheet 21 is sent to the peeling unit by the delivery mechanism and the winding mechanism, and the resin sheet 21 is pressed downward by the pressure roller. The speed at which the resin sheet 21 is sent onto the support table and the moving speed of the support table are adjusted to be the same.

The resin sheet is applied to the surface 29a of the annular frame 29 so that the opening 29c of the annular frame 29 is covered by the resin sheet 21 while moving the area to be pressed of the resin sheet 21 that is pressed by the pressing roller with respect to the support table. The resin sheet 21 is attached to the annular frame 29 by closely adhering the back surface 21 b of 21. As a result, a resin sheet unit 31 including the resin sheet 21 and the annular frame 29 is formed.

The resin sheet 21 whose outer peripheral end is fixed to the annular frame 29 is in a state of being stretched in the radial direction of the resin sheet 21. Therefore, as compared with the case where the resin sheet 21 is not attached to the annular frame 29, the resin sheet 21 can be prevented from bending under its own weight. In the pasting step (S10) of the present embodiment, the pasting device is used, but an operator may manually put the resin sheet 21 on the annular frame 29.

After the attaching step (S10), the tool cutting device 40 is used to form irregularities on the surface 21a side of the resin sheet 21 (unevenness forming step (S20)). FIG. 4 is a partial cross-sectional side view showing the unevenness forming step (S20), and FIG. 5 is a perspective view showing the unevenness forming step (S20).

The cutting tool 40 has a substantially cylindrical chuck table 50 that sucks and holds the back surface 21b side of the resin sheet 21 of the resin sheet unit 31. A rotation mechanism having a rotary drive source (not shown) such as a motor is connected to the chuck table 50 below the chuck table 50. The chuck table 50 rotates around a rotation axis substantially parallel to the Z-axis direction (vertical direction). It is rotatable.

Further, below the chuck table 50, a table moving mechanism (not shown) including a ball screw or the like is provided, and the chuck table 50 is moved by the table moving mechanism in a horizontal direction (for example, arrow 52) orthogonal to the Z-axis direction. It can be moved in the machining feed direction indicated by.

The upper surface of the chuck table 50 serves as a holding surface 50a that sucks and holds the other surface side (that is, the back surface 21b side) of the base material layer 23 of the resin sheet 21. The holding surface 50a is the surface of a disk-shaped porous plate made of a porous material. A flow path (not shown) is connected to the porous plate, and a suction source (not shown) such as an ejector is connected to the flow path.

A plurality of clamp mechanisms (not shown) are provided on the sides of the chuck table 50 so as to project from the chuck table 50. For example, four clamp mechanisms are provided at equal intervals in the circumferential direction of the chuck table 50.

Each clamp mechanism has a frame support portion (not shown) on which the back surface 29b side of the annular frame 29 is placed. The frame support portion is arranged at a position lower than the holding surface 50a, and when the annular frame 29 is placed on the frame support portion, the outer peripheral portion of the resin sheet 21 and the annular frame 29 are located below the holding surface 50a. It is placed in a low position.

A rotary drive source such as a rotary actuator is provided in the frame support portion. An arm is connected to the rotary drive source, and the arm is rotated within a predetermined angle range by the rotary drive source. A frame pressing portion (not shown) is fixed to the tip of the arm.

The frame pressing portion rotates together with the arm portion to rotate and presses the surface 29a of the annular frame 29 placed on the frame supporting portion from above, and an open position for opening the frame supporting portion. Will be placed in either. The frame pressing portion is arranged in the open position, for example, when the annular frame 29 is placed on the frame support portion or when the annular frame 29 is removed from the frame support portion.

A bite cutting unit 42 is provided above the chuck table 50. The cutting tool unit 42 has a cylindrical spindle housing 44a. The spindle housing 44a is fixed to a Z-axis moving plate (not shown) that is movable in the Z-axis direction, and this Z-axis moving plate is supported by a Z-axis moving mechanism (not shown).

A spindle 44b connected to a rotary drive source (not shown) such as a motor is rotatably accommodated in the spindle housing 44a. The lower end of the spindle 44b is exposed to the outside of the spindle housing 44a.

A wheel mount 44c is fixed to the lower end of the spindle 44b, and a disc-shaped bite wheel 46 made of metal such as stainless steel or aluminum is mounted on the lower surface of the wheel mount 44c.

A bite tool 48 is mounted on the lower surface side of the bite wheel 46. The bite tool 48 has a substantially prismatic base 48a mounted on the bite wheel 46. A cutting edge 48b made of diamond or the like is fixed to an end of the base 48a opposite to the bite wheel 46.

In the unevenness forming step (S20), first, the resin sheet unit 31 is placed on the chuck table 50 so that the back surface 21b of the resin sheet 21 contacts the holding surface 50a and the back surface 29b of the annular frame 29 contacts the frame supporting portion. Place.

At this time, the frame pressing portion is arranged at the open position. Then, the negative pressure generated by the suction source is applied to the holding surface 50a, and the back surface 21b side of the resin sheet 21 is suction-held by the chuck table 50.

Then, the rotation drive source of the frame support portion is operated to move the frame holding portion to the holding position. As a result, the annular frame 29 is clamped and fixed by the clamp mechanism.

At this time, the outer peripheral portion of the resin sheet 21 and the annular frame 29 are arranged at a position lower than the holding surface 50a, and the central portion of the resin sheet 21 located on the holding surface 50a has a flat shape. The outer peripheral portion of 21 is inclined downward from the central portion thereof toward the outside.

Next, the Z-axis moving mechanism adjusts the height position of the cutting tool unit 42 in the Z-axis direction to position the bottom of the cutting blade 48b at a height where it comes into contact with the surface 21a side of the resin sheet 21. Then, the bite wheel 46 is rotated by the rotary drive source. In this state, when the chuck table 50 is moved below the cutting tool cutting unit 42 by the table moving mechanism, the central portion of the resin sheet 21 on the front surface 21a side is cut by the cutting tool 48.

In particular, the chuck table 50 is moved along the machining feed direction so that the resin sheet unit 31 passes from directly below the spindle 44b to the other end of the bite wheel 46 in the radial direction from one end side of the bite wheel 46 in the radial direction. And move it in a straight line.

As a result, the center portion of the surface 21a of the resin sheet 21 is cut with a cutting tool. More specifically, a plurality of arcuate cutting marks are formed on the surface 21a of the resin sheet 21 along the trajectory of the bite tool 48. The bite tool 48 scratches the surface 21a side while being caught on the surface 21a side of the flexible resin sheet 21. Therefore, each arc-shaped cutting mark is composed of a plurality of minute grooves 27 which are discretely formed along the circumferential direction of the arc.

Each of the plurality of grooves 27 has a depth of about 0.1 μm to 0.3 μm from the surface 21 a, but may have a depth of several μm or less (for example, about 2 μm to 3 μm). May have a depth of 3% or less. Since the groove 27 becomes a concave portion with respect to the surface 21 a and the surface 21 a becomes a convex portion with respect to the groove 27, unevenness is formed on the surface 21 a side of the resin sheet 21.

FIG. 6 is a perspective view showing the front surface 21a side of the resin sheet 21 after the unevenness forming step (S20). Note that FIG. 6 shows the resin sheet unit 31 removed from the chuck table 50.

In the present embodiment, the irregularities are formed on the surface 21a side by cutting with the cutting tool, but the irregularities are formed on the surface 21a side by forming scratches on the surface 21a by sandblasting by mixing compressed air with an abrasive and spraying the surface 21a. May be. Further, the surface 21a may be etched by plasma etching to form irregularities on the surface 21a side.

In addition, a disc-shaped grinding wheel connected to the lower side of the spindle is rotated about the spindle as a rotation axis, and a grinding wheel provided at the bottom of the grinding wheel is brought into contact with the surface 21a. By forming, the unevenness may be formed on the surface 21a side.

By the way, the area where the unevenness is formed in the unevenness forming step (S20) may be a part of the surface 21a side, instead of the entire surface 21a side of the resin sheet 21. For example, unevenness may be formed only in the region where the workpiece 11 is arranged in the workpiece fixing step (S40) described below.

After the unevenness forming step (S20), a liquid is supplied to the surface 21a side of the resin sheet 21 having the unevenness by a liquid supply device (not shown) (liquid supplying step (S30)). FIG. 7 is a perspective view showing a liquid supply step.

The liquid supply device has, for example, a spinner table 54. A rotation mechanism (not shown) is coupled to the lower portion of the spinner table 54, and the spinner table 54 can rotate around a rotation axis that is substantially parallel to the Z-axis direction (vertical direction).

The spinner table 54 has a porous plate (not shown) on the front surface side. A flow path (not shown) is connected to the porous plate, and a suction source (not shown) such as an ejector is connected to the flow path. By applying a negative pressure generated by the suction source to the porous plate, the surface of the porous plate functions as a holding surface that sucks and holds the resin sheet unit 31.

On the side of the spinner table 54, a plurality of pendulum type clamp mechanisms (not shown) are provided so as to project from the spinner table 54. For example, four pendulum type clamp mechanisms are provided at equal intervals in the circumferential direction of the spinner table 54.

Each pendulum type clamp mechanism has a frame support portion (not shown) whose one end is connected to the spinner table 54. A pendulum type clamp (not shown) is connected to the other end of the frame support portion so as to be rotatable with respect to the frame support portion.

The pendulum clamp is located at an open position where the spinner table 54 is opened above the frame support portion when the rotation speed of the spinner table 54 is less than a predetermined value. On the other hand, when the rotation speed of the spinner table 54 is equal to or higher than the predetermined value, the spinner table 54 is located at the holding position for holding the surface 29a of the annular frame 29 mounted on the frame support from above.

The liquid supply apparatus further includes a liquid ejecting unit (not shown) for ejecting a liquid such as pure water 56 on the surface 21a side of the resin sheet 21 of the resin sheet unit 31 held by the holding surface of the spinner table 54.

The liquid ejecting unit has a substantially L-shaped arm (not shown), and a nozzle 58 for ejecting a liquid is provided at one end of this arm. The nozzle 58 is arranged so as to face the spinner table 54, and is connected to a liquid supply source (not shown) via an arm or the like.

An electric motor (not shown) that swings the arm is provided at the other end of the arm. The electric motor can swing the nozzle 58 in an arc shape so as to cross the rotation center of the spinner table 54, for example.

In the liquid supply step (S30), first, the resin sheet unit 31 is placed on the spinner table 54 so that the back surface 21b of the resin sheet 21 contacts the holding surface and the back surface 29b of the annular frame 29 contacts the frame support portion. To do.

At this time, the pendulum clamp is arranged in the open position. After that, the negative pressure generated by the suction source is applied to the holding surface, and the back surface 21b side of the resin sheet 21 is sucked and held by the holding surface of the spinner table 54.

Then, the rotating mechanism is driven to rotate the spinner table 54. When the rotation speed of the spinner table 54 becomes equal to or higher than a predetermined value, the pendulum clamp moves to a holding position where the front surface 29a of the annular frame 29 is pressed from above due to centrifugal force. As a result, the annular frame 29 is clamped by the pendulum clamp and the frame support portion.

Then, the pure water 56 is sprayed from the nozzle 58 to the front surface 21a side while swinging the nozzle 58 on the spinner table 54 in an arc shape. As a result, the pure water 56 is uniformly spread on the central portion of the surface 21a by the centrifugal force. In the liquid supply step (S30) of the present embodiment, the liquid supply device is used, but the worker may manually supply the pure water 56 to the front surface 21a side of the resin sheet 21.

The pure water 56 is, for example, water having an electric resistivity of about 0.1 MΩ·cm to 15 MΩ·cm. Examples of pure water 56 include RO (Reverse Osmosis) water purified through a reverse osmosis membrane, deionized water from which ions in water have been removed by an ion exchange resin, and distilled water obtained by distilling with a distiller. Is.

After the liquid supply step (S30), the surface 11a of the work piece 11 and the surface 21a of the base material layer 23 are opposed to each other, and the work piece 11 is pressed against the resin sheet 21 through pure water 56 to be processed. The object 11 is fixed in close contact with the resin sheet 21 (workpiece fixing step (S40)). FIG. 8 is a partial cross-sectional side view showing the workpiece fixing step (S40).

In the workpiece fixing step (S40), for example, the pressing device 60 is used. The pressing device 60 has a chuck table 62. The chuck table 62 has a porous plate (not shown) on the front surface side.

A flow path (not shown) is connected to the porous plate, and a suction source (not shown) such as an ejector is connected to the flow path. By applying a negative pressure generated by the suction source to the porous plate, the surface of the porous plate functions as a holding surface that sucks and holds the resin sheet unit 31.

A substantially disk-shaped pressing plate 66 made of metal or the like is provided at a position facing the chuck table 62. The diameter of the pressing plate 66 is larger than the diameter of the workpiece 11, for example. One end of a cylindrical rod 64 along the Z-axis direction is connected to one surface of the pressing plate 66 located on the opposite side of the chuck table 62.

An elevating mechanism (not shown) including a motor and the like is connected to the other end of the rod 64 on the side opposite to the pressing plate 66. The pressing plate 66 can be moved up and down with respect to the holding surface 62 a of the chuck table 62 by moving the rod 64 up and down with the lifting mechanism.

In the workpiece fixing step (S40), first, the resin sheet unit 31 is placed on the holding surface 62a of the chuck table 62 so that the surface 21a side of the resin sheet 21 faces upward. Then, the suction source is operated to suck and hold the back surface 29b side of the resin sheet unit 31 by the holding surface 62a.

Next, the workpiece 11 is placed on the surface 21a so that the surface 11a side of the workpiece 11 contacts the surface 21a side. Then, the elevating mechanism lowers the pressing plate 66, and the pressing plate 66 presses the back surface 11 b of the workpiece 11. The pressing force is, for example, several N to several tens N. At this time, heat may be applied to at least one of the workpiece 11 and the resin sheet 21.

By pressing the workpiece 11 with the flat disc-shaped pressing plate 66 for, for example, several seconds to several tens of seconds, a force can be applied to the workpiece 11 in the Z-axis direction substantially evenly. Since the pure water 56 is provided on the irregularities on the surface 21a side of the resin sheet 21, the surface 11a side of the pressed workpiece 11 is in close contact with the surface 21a side of the resin sheet 21 via the pure water 56. ..

After pressing, the pressing plate 66 is raised. Air is excluded between the surface 11a and the surface 21a and is filled with pure water 56, or the surface 11a of the workpiece 11 and the surface 21a of the resin sheet 21 are in close contact with each other. Therefore, even after the pressing plate 66 is separated from the workpiece 11, the workpiece 11 and the resin sheet 21 are kept pressed against each other by the atmospheric pressure.

In this way, since the groove 27 functions like a suction cup, the workpiece unit 33 in which the workpiece 11 is fixed to the annular frame 29 via the resin sheet 21 is formed. In the workpiece unit 33, the workpiece 11 is arranged on the front surface 21a side, and the annular frame 29 is arranged on the rear surface 21b side. Such an arrangement is a unique arrangement in the present embodiment in which the resin sheet 21 and the workpiece 11 are not fixed to each other via the glue layer 25.

The resin sheet 21 is not attached to the workpiece 11 by using a glue layer, but is processed through pure water supplied to the irregularities formed on the surface 21a side of the base material layer 23 of the resin sheet 21. It is attached to the object 11.

Even if the work piece 11 is peeled off from the resin sheet 21, the sizing agent does not remain on the work piece 11. Further, the liquid on the surface 11a side can be removed by simply drying the workpiece 11 after peeling the workpiece 11 from the resin sheet 21, and no impurities remain on the surface 11a side of the workpiece 11. Further, it is also advantageous that the protective tape can be manufactured at a low cost because the sizing agent for adhering the workpiece 11 is not used.

The fixing in the workpiece fixing step (S40) means temporary fixing, not permanent fixing. The work piece 11 and the resin sheet 21 are fixed by being pressed by the atmospheric pressure in the thickness direction. For example, by inserting air between the work piece 11 and the resin sheet 21, the resin The sheet 21 can be easily peeled from the workpiece 11.

By the way, although the pressing device 60 is used in the present embodiment, an operator may manually press the workpiece 11 toward the front surface 21a of the resin sheet unit 31. Alternatively, the chuck table 62 and the pressing plate 66 may be arranged upside down, and the back surface 11b side may be suction-held by the chuck table 62 so that the workpiece 11 is hung from above.

Then, by raising the resin sheet unit 31 placed on the pressing plate 66, the resin sheet is passed through the pure water 56 with the surface 11a of the workpiece 11 and the surface 21a of the resin sheet 21 facing each other. 21 may be pressed against the workpiece 11.

After the workpiece fixing step (S40), the workpiece 11 is processed. In the present embodiment, in order to grind (work) the back surface 11b side of the workpiece 11, first, the front surface 11a side of the workpiece 11 is held by the holding surface 72a of the chuck table 72 included in the grinding device 70 ( Holding step (S50)).

9A is a partial cross-sectional side view showing the holding step (S50), and FIG. 9B is a perspective view showing the holding step (S50). The chuck table 72 has a porous plate 74 on the front surface side. A flow path (not shown) is connected to the porous plate 74, and a suction source (not shown) such as an ejector is connected to the flow path.

By applying a negative pressure generated by the suction source to the porous plate 74, the surface of the porous plate 74 functions as a holding surface 72a. A rotation mechanism having a rotary drive source (not shown) such as a motor is connected to the chuck table 72 below the chuck table 72. The chuck table 72 has a rotary shaft substantially parallel to the Z-axis direction (vertical direction). It can rotate around.

A plurality of clamping mechanisms (not shown) are provided on the side of the chuck table 72 so as to project from the chuck table 72. However, since the clamp mechanism is the same as the clamp mechanism of the cutting tool 40, the description thereof will be omitted.

In the holding step (S50), first, the workpiece unit 33 is placed on the chuck table 72 so that the back surface 21b of the resin sheet 21 contacts the holding surface 72a and the back surface 29b of the annular frame 29 contacts the frame supporting portion. Place.

At this time, the frame pressing portion is arranged at the open position. After that, a negative pressure generated by a suction source is applied to the holding surface 72a, and the back surface 21b side of the resin sheet 21 is sucked and held by the chuck table 72.

Then, the rotation drive source of the frame support portion is operated to move the frame holding portion to the holding position. As a result, the front surface 29a and the back surface 29b of the annular frame 29 are clamped and fixed by the clamp mechanism.

At this time, the outer peripheral portion of the resin sheet 21 and the annular frame 29 are arranged at a position lower than the holding surface 72a, and the central portion of the resin sheet 21 located on the holding surface 72a has a flat shape. The outer peripheral portion of 21 is inclined downward from the central portion thereof toward the outside.

After the holding step (S50), the back surface 11b side of the workpiece 11 is ground (grinding step (S60)). FIG. 10 is a partial cross-sectional side view showing the grinding step (S60), and FIG. 11 is a perspective view showing the grinding step (S60).

In the grinding step (S60), the grinding device 70 is used. The grinding device 70 has, in addition to the chuck table 72 described above, a grinding unit 80 provided so as to face the holding surface 72 a of the chuck table 72.

The grinding unit 80 has a cylindrical spindle housing 82a. A part of the side portion of the spindle housing 82a is fixed to a Z-axis moving plate (not shown) that is movable in the Z-axis direction. A spindle 82b is rotatably housed inside the spindle housing 82a.

A rotary drive source (not shown) such as a motor for rotationally driving the spindle 82b is connected to the upper end of the spindle 82b. On the other hand, the lower end of the spindle 82b is exposed to the outside from the lower surface of the spindle housing 82a. A disk-shaped wheel mount 82c is provided at the lower end of the spindle 82b.

A grinding wheel 84 is mounted on the opposite side of the wheel mount 82c from the spindle 82b. The grinding wheel 84 has an annular wheel base 84a which has a diameter substantially equal to that of the wheel mount 82c and is made of metal such as stainless steel.

One annular surface of the wheel base 84a is a mounting surface to be mounted on the wheel mount 82c. A plurality of grinding wheels 84b are annularly arranged and fixed to the other surface of the circular ring located on the side opposite to the mounting surface.

The grinding wheel 84b is formed, for example, by mixing a bonding material such as metal, ceramics, or resin with abrasive grains such as diamond or cBN (cubic boron nitride). However, the binder and the abrasive grains are not limited, and can be appropriately selected according to the specifications of the grinding wheel 24.

In the grinding step (S60), for example, the chuck table 72 and the grinding unit 80 are rotated in the same direction while the grinding unit 80 is lowered along the Z-axis direction. The back surface 11b side is ground by the bottom portion of the grinding wheel 84b that swivels in contact with the back surface 11b side of the workpiece 11.

After grinding the back surface 11b side until the workpiece 11 has a predetermined finished thickness, the grinding step (S60) is ended. When peeling the work piece 11 from the resin sheet unit 31, first, the adhesiveness of the glue layer 25 is increased by applying an external stimulus such as ultraviolet rays or heat to the glue layer 25 to cure the glue layer 25. Make it disappear.

Thereby, the annular frame 29 can be easily peeled off from the resin sheet 21. Next, the end portion of the resin sheet 21 is rolled up, and air is introduced between the workpiece 11 and the resin sheet 21. Thereby, the resin sheet 21 can be easily peeled from the workpiece 11. Note that FIG. 12 is a flow chart showing the processing method of the first embodiment.

As a first modification of the first embodiment, the unevenness forming step (S20) may be performed before the attaching step (S10) to form the unevenness on the surface 21a side of the resin sheet 21.

For example, the release sheet side (that is, the back surface 21b side) of the resin sheet 21 attached to the release sheet (not shown) is suction-held by the holding surface 52a of the chuck table 50, and then the bite cutting unit 42. The surface 21a side is cut with.

As a result, after the unevenness is formed on the surface 21a side of the resin sheet 21, the attaching step (S10) is performed, and then the liquid supplying step (S30) is performed. Thereafter, the workpiece fixing step (S40), the holding step (S50), and the grinding step (S60) are sequentially performed.

As a second modification of the first embodiment, the pure water 56 may be supplied to the surface 11a side of the workpiece 11 instead of supplying the pure water 56 to the surface 21a side of the resin sheet 21. Then, using the pressing device 60, the surface 11a side of the workpiece 11 is pressed against the surface 21a side of the resin sheet 21 through the pure water 56, or the surface 21a side of the resin sheet 21 is pressed through the pure water 56. The workpiece 11 is pressed against the surface 11a side (a workpiece fixing step (S40)). After that, the holding step (S50) and the grinding step (S60) are sequentially performed.

Next, a second embodiment will be described. In the second embodiment, a polishing step (S65) of polishing the back surface 11b side of the workpiece 11 is performed instead of the polishing step (S60). The polishing step (S65) is performed after the holding step (S50) of holding the workpiece unit 33 on the chuck table 92 of the polishing device 90. FIG. 13 is a partial cross-sectional side view showing the polishing step (S65). Note that FIG. 14 is a flow chart showing the processing method of the second embodiment.

In the polishing step (S65), the polishing device 90 is used. The polishing device 90 has a chuck table 92. The chuck table 92 has a porous plate (not shown) on the front surface side. A flow path (not shown) is connected to the porous plate, and a suction source (not shown) such as an ejector is connected to the flow path.

By applying a negative pressure generated by the suction source to the porous plate, the surface of the porous plate functions as a holding surface. A rotation mechanism having a rotary drive source (not shown) such as a motor is connected to the chuck table 92 below, and the chuck table 92 has a rotary shaft substantially parallel to the Z-axis direction (vertical direction). It can rotate around. Since the structure of the chuck table 92 is the same as that of the chuck table 72 of the grinding device 70, further description will be omitted.

The polishing device 90 includes a chuck table 92 and a polishing unit 94 provided to face the holding surface 92 a of the chuck table 92. The polishing unit 94 has a cylindrical spindle housing 96a.

A part of the side portion of the spindle housing 96a is fixed to a Z-axis moving plate (not shown) that is movable in the Z-axis direction, and this Z-axis moving plate is supported by a Z-axis moving mechanism (not shown). There is. A spindle 96b is rotatably housed inside the spindle housing 96a.

A rotary drive source (not shown) such as a motor for rotating the spindle 96b is connected to the upper end of the spindle 96b. On the other hand, the lower end of the spindle 96b is exposed to the outside from the lower surface of the spindle housing 96a. A disk-shaped wheel mount 96c is provided at the lower end of the spindle 96b.

A polishing wheel 98 is mounted on the side of the wheel mount 96c opposite to the spindle 96b. The polishing wheel 98 has a disk-shaped wheel base 98a having a diameter substantially equal to that of the wheel mount 96c and formed of metal such as stainless steel.

One disk-shaped surface of the wheel base 98a is a mounting surface mounted on the wheel mount 96c. A disc-shaped polishing pad 98b is fixed to the other disc-shaped surface located on the side opposite to the mounting surface.

The polishing pad 98b is formed, for example, by dispersing abrasive grains in urethane foam and fixing the dispersed abrasive grains with a bonding agent. As the material of the abrasive grains, for example, GC (Green silicon Carbide), WA (White fused Alumina), diamond, cBN or the like is used. Further, a nonwoven fabric may be used instead of the urethane foam.

In the polishing step (S65), the chuck table 92 and the polishing unit 94 are rotated in the same direction, and the polishing unit 94 is moved down along the Z-axis direction. The bottom surface of the rotating polishing pad 98b comes into contact with the back surface 11b side of the workpiece 11 to polish the back surface 11b side.

Also in the first modification of the second embodiment, the unevenness forming step (S20) may be performed before the attaching step (S10) to form the unevenness on the surface 21a side of the resin sheet 21. That is, after the unevenness forming step (S20), the attaching step (S10) is performed, and then the liquid supplying step (S30), the workpiece fixing step (S40), the holding step (S50) and the polishing step (S65). You may go sequentially.

Also in the second modification of the second embodiment, pure water 56 may be supplied to the surface 11a side of the workpiece 11. Then, using the pressing device 60, the surface 11a side of the workpiece 11 is pressed against the surface 21a side of the resin sheet 21 through the pure water 56, or the surface 21a side of the resin sheet 21 is pressed through the pure water 56. The workpiece 11 is pressed against the surface 11a side (a workpiece fixing step (S40)). Thereafter, the holding step (S50) and the polishing step (S65) are sequentially performed.

By the way, in the above-mentioned 1st Embodiment and 2nd Embodiment, although one to-be-processed object 11 was fixed to the surface 21a side of the resin sheet unit 31, a plurality of to-be-processed objects are provided to the surface 21a side of the resin sheet unit 31. 11 may be fixed.

FIG. 15A is a perspective view showing a state in which a plurality of disk-shaped workpieces 11 are fixed to the resin sheet 21, and the workpieces 11 are removed from the chuck table 62 used in the workpiece fixing step (S40). The work piece unit 33 in a state is shown. In addition, in FIG. 15A, the three workpieces 11 are fixed to the resin sheet 21, but two or four or more workpieces 11 may be fixed to the resin sheet 21.

Further, the shape of the workpiece 11 is not limited to the disc shape, and may be a rectangular shape. FIG. 15B is a perspective view showing a state where a plurality of workpieces 11 each having a rectangular shape in a plan view are fixed to the resin sheet 21. The chuck table 62 used in the workpiece fixing step (S40) is shown in FIG. The work unit 33 in a removed state is shown. Two or four or more rectangular workpieces 11 may be fixed to the resin sheet 21.

In addition, the structures, methods, and the like according to the above-described embodiments can be appropriately modified and implemented without departing from the scope of the object of the present invention. For example, according to the flow of each step of the processing method, after performing from the attaching step (S10) to the holding step (S50), instead of the grinding step (S60) or the polishing step (S65), it is supported by the annular frame 29. The workpiece 11 may be observed, measured, or transported.

In the observation method, the measurement method, or the transportation method of observing, measuring, or transporting the workpiece 11 in the state of the workpiece unit 33, the workpiece 11 is processed as compared with the case where the workpiece 11 is not supported by the annular frame 29. It becomes easy to handle the object 11. Of course, as described above, even if the workpiece 11 is peeled from the resin sheet 21, the sizing agent does not remain on the workpiece 11.

Further, the resin sheet 21 that has been used once may be reused. However, in the used resin sheet 21, the groove 27 may become wider than when it is formed, and it may be difficult to function as a suction cup. Therefore, when the used resin sheet 21 is reused, it is more preferable to perform the unevenness forming step (S20) again to form the unevenness on the surface 21a side.

11 Workpiece 11a Surface 11b Backside 13 Planned Division Line 15 Device 21 Resin Sheet 21a Surface 21b Backside 23 Base Material Layer 25 Adhesive Layer 27 Groove 29 Annular Frame 29a Surface 29b Backside 29c Opening 31 Resin Sheet Unit 33 Workpiece Unit 40 Bit cutting device 42 Bit cutting unit 44a Spindle housing 44b Spindle 44c Wheel mount 46 Bit wheel 48 Bit tool 48a Base 48b Cutting edge 50 Chuck table 50a Holding surface 52 Arrow 54 Spinner table 56 Pure water 58 Nozzle 60 Pressing device 62 Chuck table 62a Holding Surface 64 Rod 66 Pressing plate 70 Grinding device 72 Chuck table 72a Holding surface 74 Porous plate 80 Grinding unit 82a Spindle housing 82b Spindle 82c Wheel mount 84 Grinding wheel 84a Wheel base 84b Grinding grindstone 90 Polishing device 92 Chuck table 92a Holding surface 94 Polishing Unit 96a Spindle housing 96b Spindle 96c Wheel mount 98 Polishing wheel 98a Wheel base 98b Polishing pad

Claims (3)

A method of processing a work piece, comprising grinding a back surface side of the work piece having a device formed on the front surface side to a predetermined finish thickness,
A sticking step of sticking the glue layer side of a resin sheet having a laminated structure of a glue layer and a base material layer to the annular frame so as to cover the opening of the annular frame having an opening;
Before or after the attaching step, an unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the glue layer,
A liquid supply step of supplying a liquid to the surface side of the base material layer on which the unevenness is formed or the surface side of the workpiece after the attaching step and the unevenness forming step;
The surface of the workpiece and the surface of the base material layer are opposed to each other, and the workpiece is pressed against the resin sheet through the liquid, or the resin sheet is processed through the liquid. A workpiece fixing step of pressing the workpiece to fix the workpiece in close contact with the resin sheet;
A holding step of holding the front surface side of the workpiece fixed to the resin sheet with a holding surface of a rotatable chuck table;
After the holding step, a grinding step of grinding the back surface side of the workpiece with a grinding wheel of a grinding wheel provided facing the holding surface,
A method for processing a work piece, comprising: A method of processing a work piece, comprising polishing a back surface side of the work piece having a device formed on the front surface side,
A sticking step of sticking the glue layer side of a resin sheet having a laminated structure of a glue layer and a base material layer to the annular frame so as to cover the opening of the annular frame having an opening;
Before or after the attaching step, an unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the glue layer,
A liquid supply step of supplying a liquid to the surface side of the base material layer on which the unevenness is formed or the surface side of the workpiece after the attaching step and the unevenness forming step;
The surface of the workpiece and the surface of the base material layer are opposed to each other, and the workpiece is pressed against the resin sheet through the liquid, or the resin sheet is processed through the liquid. A workpiece fixing step of pressing the workpiece to fix the workpiece in close contact with the resin sheet;
A holding step of holding the front surface side of the workpiece fixed to the resin sheet with a holding surface of a rotatable chuck table;
After the holding step, a polishing step of polishing the back surface side of the workpiece with a polishing pad provided to face the holding surface,
A method for processing a work piece, comprising: The method for processing a work piece according to claim 1 or 2, wherein the liquid is pure water.