JP7166730B2 - Workpiece processing method - Google Patents

Description

The present invention relates to a processing method for processing a workpiece fixed to a support base or an annular frame via a resin sheet.

As a preliminary preparation for cutting (processing) a wafer made of a semiconductor material or the like, for example, a glue layer ( There is known a technique of forming a wafer unit to which the adhesive layer side of a resin sheet (dicing tape) having an adhesive layer is attached.

A laser beam is irradiated from the surface side of the wafer while one surface of the resin sheet opposite to the adhesive layer is held by a chuck table, and the chuck table is moved at a predetermined processing feed speed. As a result, the wafer is processed along dividing lines (streets) set on the wafer, and finally divided into a plurality of chips (see Patent Document 1, for example).

Japanese Patent Application Laid-Open No. 2004-160483

However, there is a problem that when the chips after division are peeled off from the resin sheet, the glue constituting the glue layer remains on the chips (so-called glue residue occurs). SUMMARY OF THE INVENTION It is an object of the present invention to provide a processing method for processing a workpiece without fixing a resin sheet to the workpiece with a glue made of a resin having adhesiveness. and

According to one aspect of the present invention, there is provided a method for processing a workpiece, in which a device is formed on the surface side of the workpiece and the workpiece is processed along a planned dividing line, the workpiece comprising: a glue layer and a base material layer The adhesive layer side of the resin sheet having a laminated structure of is attached to a support base, and before or after the attaching step, on the surface side of the base material layer opposite to the adhesive layer an unevenness forming step of forming unevenness; a liquid supply step of supplying a liquid to the surface side of the substrate layer on which the unevenness is formed or to the workpiece after the attaching step and the unevenness forming step; Pressing the workpiece against the resin sheet through the liquid, or pressing the resin sheet against the workpiece through the liquid, and fixing the workpiece in close contact with the resin sheet. an object fixing step; a holding step of holding a surface of the support base, to which the workpiece is fixed via the resin sheet, opposite to the resin sheet with a holding surface of a chuck table; followed by a laser beam irradiation step of irradiating a laser beam from a laser irradiation unit provided on the holding surface along a plurality of planned dividing lines set on the workpiece held on the chuck table; A method of processing a workpiece is provided comprising:

According to another aspect of the present invention, there is provided a method for processing a workpiece, in which a device is formed on the surface side of the workpiece and the workpiece is processed along a planned dividing line, comprising: a glue layer; an attaching step of attaching the adhesive layer side of a resin sheet having a laminated structure of layers to a support base; and before or after the attaching step, the surface side of the base material layer opposite to the adhesive layer. After the unevenness forming step of forming unevenness on the workpiece, and after the pasting step and the unevenness forming step, the workpiece is pressed against the resin sheet or the resin sheet is pressed against the workpiece, and the workpiece is to the resin sheet, and a step of fixing the workpiece to the resin sheet; a holding step of holding on the holding surface; and after the holding step, a laser irradiation unit provided on the holding surface along a plurality of planned dividing lines set on the workpiece held on the chuck table. and a laser beam irradiation step of irradiating a laser beam from a workpiece.

According to still another aspect of the present invention, there is provided a processing method for processing a workpiece having a device formed on the surface thereof along a line to divide the workpiece, the workpiece having an opening. a pasting step of pasting 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 ring frame, and before or after the pasting step; an unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the adhesive layer; a liquid supplying step of supplying a liquid to the surface side workpiece or the workpiece; pressing the workpiece against the resin sheet via the liquid or pressing the resin sheet against the workpiece via the liquid; a workpiece fixing step of pressing the workpiece against the resin sheet and fixing the workpiece to the resin sheet; and holding the resin sheet side of the workpiece fixed to the resin sheet by the holding surface of the chuck table. a holding step, and after the holding step, irradiating a laser beam from a laser irradiation unit provided on the holding surface along a plurality of planned division lines set on the workpiece held on the chuck table. and a laser beam irradiation step for processing a workpiece.

According to still another aspect of the present invention, there is provided a processing method for processing a workpiece having a device formed on the surface thereof along a line to divide the workpiece, the workpiece having an opening. a pasting step of pasting 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 ring frame, and before or after the pasting step; , after the unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the glue layer, and the pasting step and the unevenness forming step, pressing the workpiece against the resin sheet or a workpiece fixing step of pressing the resin sheet against the workpiece and fixing the workpiece by bringing the workpiece into close contact with the resin sheet; a holding step of holding the workpiece on the holding surface of the chuck table; and a laser beam irradiation step of irradiating a laser beam from a laser irradiation unit.

Preferably, the liquid is pure water.

In the processing method according to one 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 support base. Then, irregularities are formed on the surface of the base material layer located on the opposite side of the glue layer, and the liquid is supplied to the irregularities. Next, by pressing the workpiece against the resin sheet through the liquid, the workpiece is brought into close contact with the resin sheet and fixed. In other words, since no glue is used to fix the resin sheet to the workpiece, the glue does not remain on the workpiece even when the workpiece is peeled off from the resin sheet.

It is a perspective view of a to-be-processed object. It is a perspective view of a resin sheet. It is a perspective view which shows an affixing step. It is a side view which shows an uneven|corrugated formation step. It is a perspective view which shows an uneven|corrugated formation step. FIG. 4 is a perspective view showing the surface side of the resin sheet after the unevenness forming step; It is a perspective view which shows a liquid supply step. It is a side view which shows a to-be-processed object fixing step. FIG. 9A is a cross-sectional view showing the holding step, and FIG. 9B is a perspective view showing the holding step. FIG. 10A is a partial cross-sectional side view showing the laser beam irradiation step, and FIG. 10B is a perspective view showing the laser beam irradiation step. It is a flow figure which shows the processing method of 1st Embodiment. It is a flowchart which shows the processing method of 2nd Embodiment. FIG. 13A is a perspective view showing a state in which a plurality of disk-shaped workpieces are fixed to a resin sheet, and FIG. FIG. 4 is a perspective view showing a state fixed to a seat; It is a perspective view which shows an affixing step. It is a partial cross-sectional side view which shows an uneven|corrugated formation step. It is a perspective view which shows an uneven|corrugated formation step. FIG. 4 is a perspective view showing the surface side of the resin sheet after the unevenness forming step; It is a perspective view which shows a liquid supply step. It is a partial cross-sectional side view which shows a workpiece fixing step. FIG. 20(A) is a sectional view showing the holding step, and FIG. 20(B) is a perspective view showing the holding step. FIG. 21A is a partial cross-sectional side view showing the laser beam irradiation step, and FIG. 21B is a perspective view showing the laser beam irradiation step. It is a flowchart which shows the processing method of 3rd Embodiment. It is a flowchart which shows the processing method of 4th Embodiment. FIG. 24A is a perspective view showing a state in which a plurality of disk-shaped workpieces are fixed to a resin sheet, and FIG. FIG. 4 is a perspective view showing a state fixed to a seat;

An embodiment according to one 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 mainly made of a material such as silicon.

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

Note that the workpiece 11 may be made of a semiconductor or insulator other than silicon. Further, the shape, structure, size, etc. of the workpiece 11 are not limited, and the type, quantity, shape, structure, size, arrangement, etc. of the device 15 are also not limited.

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 . The resin sheet 21 has a laminated structure of a base material layer 23 and an adhesive layer 25 .

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

The base material layer 23 is a film-like solid layer configured in a circular shape. 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), polyethylene terephthalate (PET).

A glue layer 25 is provided on the entire other surface of the base material layer 23 (that is, the surface opposite to the surface 21a). Note that the adhesive layer 25 may be provided annularly near the outer circumference of the other surface of the base material layer 23 . The glue layer 25 is a layer made of a glue (that is, an adhesive), and is made of a material such as silicone rubber, acrylic resin, or epoxy resin. Note that the adhesive layer 25 has a property of losing adhesiveness and hardening due to an external stimulus such as ultraviolet rays or heat.

Next, a method for processing the workpiece 11 will be described. In the processing method, first, the back surface 21b of the resin sheet 21 is attached to the support base 29 to integrate the resin sheet 21 and the support base 29 (attaching step (S10)).

FIG. 3 is a perspective view showing the sticking step (S10). The support base 29 is a disk-shaped substrate having substantially the same diameter as the base material layer 23 and having both flat surfaces, and has a predetermined thickness (for example, about 1 mm).

The support base 29 is made of various glass materials such as soda glass, borosilicate glass, and quartz glass, but may be made of other materials such as semiconductor materials and resin materials. In the present embodiment, for the sake of convenience, one surface of the support base 29 to which the resin sheet 21 is attached is referred to as the surface 29a of the support base 29, and the other surface of the support base 29 opposite to the surface 29a is referred to as the surface 29a. The rear surface 29b of the support base 29 is called.

In the attaching step (S10), for example, the back surface 21b of the resin sheet 21 is attached to the front surface 29a of the support base 29 using an attaching device (not shown). The application device has a support table (not shown) that supports the support base 29 .

The support base 29 is arranged on the support table so that the back surface 29b of the support base 29 is in contact with the surface of the support table. A movement mechanism (not shown) such as a ball screw is provided on the back side of the support table, and the support table can be moved in a predetermined direction by this movement mechanism.

A cylindrical pressure roller (not shown) is arranged above the support table to press the resin sheet 21 toward the support table. Also, the direction of the rotation axis of the cylinder of the pressure roller is orthogonal to the above-mentioned predetermined direction, which is the movement direction of the support table.

The sticking device has a delivery mechanism (not shown) that delivers a tape body (not shown) with a release sheet pasted on the adhesive layer 25 side of the resin sheet 21 toward the pressure roller. The sticking device further has a peeling unit (not shown) for peeling the resin sheet 21 from the release sheet when the resin sheet 21 is fed between the pressure roller and the support base 29 .

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

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

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

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

The back surface 21 b of the resin sheet 21 is brought into close contact with the front surface 29 a of the support base 29 while moving the pressurized area of the resin sheet 21 pressed by the pressure roller with respect to the support table. A resin sheet 21 is attached to the . Thereby, a resin sheet unit 31 composed of the resin sheet 21 and the support base 29 is formed.

The film-shaped resin sheet 21 is fixed and does not bend by being attached to the support base 29 . Therefore, it is possible to prevent bending of the workpiece 11 and the resin sheet 21 during processing such as a laser beam irradiation step (S60), which will be described later.

In addition, in the affixing step (S10) of the present embodiment, an affixing device is used, but the resin sheet 21 may be manually affixed to the support base 29 by an operator. After the affixing step (S10), the cutting tool 40 is used to form unevenness on the surface 21a side of the resin sheet 21 (unevenness forming step (S20)).

FIG. 4 is a side view showing the unevenness forming step (S20), and FIG. 5 is a perspective view showing the unevenness forming step (S20). FIG. 6 is a perspective view showing the surface 21a side of the resin sheet 21 after the unevenness forming step (S20).

The cutting tool 40 has a chuck table 50 that holds the back surface 29b side of the support base 29 by suction. A rotation mechanism having a rotation drive source (not shown) such as a motor is connected to the chuck table 50 below. Rotatable.

Further, below the chuck table 50, a table moving mechanism (not shown) composed of a ball screw or the like is provided. can move in the processing feed direction indicated by ).

The upper surface of the chuck table 50 serves as a holding surface 50a that holds the back surface 29b side of the support base 29 by suction. The holding surface 50a is the surface of a disk-shaped porous plate made of a porous material. A channel (not shown) is connected to the porous plate, and a suction source (not shown) such as an ejector is connected to this channel.

A cutting tool 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) movable in the Z-axis direction, and the Z-axis moving plate is supported by a Z-axis moving mechanism (not shown).

A spindle 44b connected to a rotational drive source (not shown) such as a motor is rotatably accommodated in the spindle housing 44a. A lower end portion 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 disk-shaped bite wheel 46 made of metal such as stainless steel or aluminum is attached to the lower surface of the wheel mount 44c.

A bite tool 48 is attached to the lower surface side of the bite wheel 46 . The bite tool 48 has a substantially prismatic base portion 48 a attached to the bite wheel 46 . A cutting edge 48b made of diamond or the like is fixed to the end of the base 48a opposite to the bite wheel 46. As shown in FIG.

In the unevenness forming step (S20), first, the resin sheet unit 31 is placed on the chuck table 50 so that the back surface 29b side of the support base 29 is in contact with the holding surface 50a. After that, the negative pressure generated by the suction source is applied to the holding surface 50a, and the back surface 29b of the support base 29 is held by the chuck table 50 by suction.

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

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

As a result, substantially the entire surface 21a of the resin sheet 21 is cut with a cutting tool. More specifically, along the trajectory of the cutting tool 48, a plurality of arc-shaped cutting marks are formed on the surface 21a of the resin sheet 21. As shown in FIG. The cutting tool 48 is caught on the surface 21a side of the flexible resin sheet 21 and scratches the surface 21a side. Therefore, each arc-shaped cut mark is composed of a plurality of minute grooves 27 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 21a, 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 of the thickness of the Since the grooves 27 are concave portions with respect to the surface 21a and the surface 21a is convex portions with respect to the grooves 27, unevenness is formed on the surface 21a side of the resin sheet 21. FIG.

In the present embodiment, unevenness is formed on the surface 21a side by cutting with a tool. may be formed. Further, the unevenness may be formed on the surface 21a side by etching the surface 21a by plasma etching.

Furthermore, while rotating a disk-shaped grinding wheel connected to the lower part of the spindle with the spindle as the rotation axis, the grinding wheel provided at the bottom of the grinding wheel is brought into contact with the surface 21a. You may form unevenness|corrugation in the surface 21a side by forming.

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

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

The liquid supply device has, for example, a spinner table (not shown). A rotation mechanism (not shown) is connected to the spinner table below, and the spinner table can rotate around a rotation axis generally parallel to the Z-axis direction (vertical direction).

Also, the spinner table has a porous plate (not shown) on the surface side. A channel (not shown) is connected to the porous plate, and a suction source (not shown) such as an ejector is further connected to this channel. By applying the negative pressure generated by the suction source to the porous plate, the surface of the porous plate functions as a holding surface for holding the resin sheet unit 31 by suction.

The liquid supply device further has a liquid jetting unit (not shown) that jets liquid such as pure water 56 . The liquid injection unit, for example, injects pure water 56 onto the surface 21a of the resin sheet 21 of the resin sheet unit 31 held on the holding surface of the spinner table.

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

An electric motor for swinging the arm is provided at the other end of the arm. The electric motor can, for example, swing the nozzle 54 in an arc across the center of rotation of the spinner table.

In the liquid supply step (S30), first, the back surface 29b side of the resin sheet unit 31 is sucked and held by the holding surface of the spinner table. Next, the rotating mechanism is driven to rotate the spinner table.

Then, while swinging the nozzle 54 in an arc shape on the spinner table, the pure water 56 is jetted from the nozzle 54 toward the surface 21a. As a result, the pure water 56 spreads uniformly over the surface 21a due to centrifugal force. In the liquid supply step (S30) of the present embodiment, a liquid supply device is used, but the pure water 56 may be uniformly supplied to the surface 21a side of the resin sheet 21 manually by an operator.

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, etc., and distilled water obtained by distillation with a distiller. is.

After the liquid supply step (S30), the back surface 11b of the workpiece 11 and the front surface 21a of the resin sheet 21 are opposed to each other, and the workpiece 11 is pressed against the resin sheet 21 via the pure water 56 to press the workpiece 11 against the resin sheet 21. 11 is brought into close contact with the resin sheet 21 and fixed (work piece fixing step (S40)).

FIG. 8 is a 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 surface side.

A channel (not shown) is connected to the porous plate, and a suction source (not shown) such as an ejector is further connected to this channel. By applying negative pressure generated by the suction source to the porous plate, the surface of the porous plate functions as a holding surface 62a for holding the resin sheet unit 31 by suction.

At a position facing the chuck table 62, a substantially disk-shaped pressing plate 66 made of metal or the like is provided. 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 extending along the Z-axis direction is connected to one surface of a pressing plate 66 located on the side opposite to the chuck table 62 .

A lifting mechanism (not shown) including a motor and the like is connected to the other end of the rod 64 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 rear surface 29b side of the resin sheet unit 31 with the holding surface 62a.

Next, the workpiece 11 is placed on the front surface 21a so that the back surface 11b side of the workpiece 11 is in contact with the front surface 21a side. Then, the pressing plate 66 is lowered by the elevating mechanism, and the pressing plate 66 presses the surface 11 a of the workpiece 11 . Note that the pressing force is, for example, about several N to several tens of 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 several seconds to several tens of seconds, for example, a substantially uniform force can be applied to the workpiece 11 in the Z-axis direction. Since pure water 56 is provided on the unevenness on the surface 21a side of the resin sheet 21, the back surface 11b 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 removed from the space between the back surface 11b of the workpiece 11 and the surface 21a of the resin sheet 21, and the space is filled with pure water 56, or the back surface 11b and the surface 21a 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.

Since the grooves 27 function like suction cups in this way, a workpiece unit 33 in which the workpiece 11 is fixed to the support base 29 via the resin sheet 21 is formed. The resin sheet 21 is not attached to the workpiece 11 using a glue layer, but is attached to the workpiece 11 via pure water 56 supplied to the irregularities formed on the surface 21a side of the base layer 23 of the resin sheet 21. It is attached to the workpiece 11 .

Even if the workpiece 11 is peeled off from the resin sheet 21 , the paste will not remain on the workpiece 11 . Further, the liquid on the back surface 11b side of the workpiece 11 can be removed only by drying the workpiece 11 after peeling the workpiece 11 from the resin sheet 21, and no impurities remain on the back surface 11b side of the workpiece 11. - 特許庁Another advantage is that the masking tape can be manufactured at low cost because no paste is used to adhere the workpiece 11 .

Fixing in the workpiece fixing step (S40) means temporary fixing, not permanent fixing. The workpiece 11 and the resin sheet 21 are fixed by being pressed by the atmospheric pressure in the thickness direction. The sheet 21 can be easily peeled off from the workpiece 11 .

The force by which the workpiece 11 is fixed to the resin sheet 21 (or the resin sheet 21 to the workpiece 11) through the liquid is the force that the workpiece 11 is fixed to the resin sheet 21 (or the resin sheet 21) without the liquid. stronger than the force with which the sheet 21 is fixed) to the workpiece 11). Therefore, it is possible to fix the workpiece 11 and the resin sheet 21 more strongly than when the liquid is not interposed.

In the workpiece fixing step (S40), the surface 11a side of the workpiece 11 is pressed by the pressing plate 66, but basically the surface 11a is not scratched or damaged. However, a protective member may be provided on the surface 11a in order to more reliably avoid scratching or damage to the surface 11a.

The protective member may be a protective film such as a water-soluble resin film or a resin sheet having no adhesive layer. After the workpiece fixing step (S40), the water-soluble resin film is removed, for example, by washing with the spinner table used in the liquid supply step (S30), and the resin sheet is removed by a removing device or manually. It is removed by rolling it off from the object 11 .

By the way, in this embodiment, the pressing device 60 is used, but the 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 surface 11a side may be suction-held by the chuck table 62 so as to suspend the workpiece 11 from above.

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

After the workpiece fixing step (S40), the workpiece 11 is processed. In this embodiment, in order to process the workpiece 11 with a laser beam, first, the back surface 29b of the support base 29 located on the side opposite to the resin sheet 21 is held by the chuck table 72 of the laser processing device 70. It is held by the surface 72a (holding step (S50)).

FIG. 9A is a sectional 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 surface side. A channel (not shown) is connected to the porous plate 74, and a suction source (not shown) such as an ejector is connected to the channel.

By applying the 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 rotation drive source (not shown) such as a motor is connected to the chuck table 72 below. It is rotatable around.

In the holding step (S50), first, the workpiece unit 33 is placed on the holding surface 72a so that the back surface 29b side of the support base 29 is in contact with the holding surface 72a. Then, the workpiece unit 33 is held by the chuck table 72 by applying a negative pressure to the holding surface 72a by the suction mechanism.

After the holding step (S50), the laser processing device 70 is used to irradiate the workpiece 11 with a laser beam along a plurality of division lines set (laser beam irradiation step (S60)). FIG. 10A is a partial cross-sectional side view showing the laser beam irradiation step (S60), and FIG. 10B is a perspective view showing the laser beam irradiation step (S60). In the laser beam irradiation step (S60), the laser processing device 70 is used to irradiate the laser beam L to the workpiece 11, and the workpiece 11 is ablated.

Laser beam L has a wavelength that is absorbed by workpiece 11 . Laser processing conditions in the laser irradiation step (S60) are, for example, as follows.
Light source: Nd: YAG pulse laser Wavelength: 355 nm
Average output: 6.0W
Repetition frequency: 20kHz
Feeding speed: 400mm/sec

The laser processing apparatus 70 has a laser irradiation unit 76 provided on the holding surface 72 a of the chuck table 72 in addition to the chuck table 72 described above. The laser irradiation unit 76 includes a laser processing head 76a that emits a pulsed laser beam L from its tip. The laser processing head 76a has a lens for condensing the emitted laser beam L therein.

The laser processing apparatus 70 also has an imaging unit 76b branched from the main body of the laser irradiation unit 76 and arranged in the vicinity of the laser processing head 76a. The image of the workpiece 11 captured by the imaging unit 76b is used for alignment of the workpiece 11 and the laser processing head 76a.

In the laser irradiation step (S60), the laser beam L is irradiated from the laser processing head 76a toward the surface 11a of the workpiece 11 while the laser processing head 76a and the chuck table 72 are relatively moved. Thereby, the workpiece 11 is machined along the path of this relative movement.

After the laser beam L is irradiated along all the dividing lines 13 parallel to one direction, the chuck table 72 is rotated by 90 degrees. Then, the laser beam L is irradiated along all the planned dividing lines 13 in the other direction orthogonal to the one direction. Thereby, the workpiece 11 is ablated along all the dividing lines 13 and divided into a plurality of chips each including the device 15 along the dividing lines 13 .

When separating the workpiece 11 from the resin sheet unit 31, first, the glue layer 25 is hardened by applying an external stimulus such as ultraviolet light or heat to the glue layer 25, thereby reducing the stickiness of the glue layer 25. disappear. Thereby, the support base 29 can be easily peeled off from the resin sheet 21 .

Next, the end of the resin sheet 21 is rolled up to introduce air between the chip and the resin sheet 21 . Thereby, the resin sheet 21 can be easily peeled off from the chip. FIG. 11 is a flowchart showing the processing method of the first embodiment.

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

For example, after the release sheet side (that is, the back surface 21b side) of the resin sheet 21 attached to the release sheet (not shown) is held by suction with the holding surface 52a of the chuck table 50, the tool cutting unit 42 to cut the surface 21a side. As a result, unevenness is formed on the surface 21 a side of the resin sheet 21 .

After that, the affixing step (S10) is performed, and then the liquid supply step (S30) is performed. Thereafter, a workpiece fixing step (S40), a holding step (S50) and a laser beam irradiation step (S60) are sequentially performed.

Further, as a second modification of the first embodiment, the pure water 56 may be supplied to the workpiece 11 instead of the resin sheet 21 . For example, pure water 56 is supplied to the back surface 11b side of the workpiece 11 . Then, using the pressing device 60, the back surface 11b side of the workpiece 11 is pressed against the front surface 21a side of the resin sheet 21 through the pure water 56, or the back surface 11b side of the resin sheet 21 is pressed through the pure water 56. The surface 11a side of the workpiece 11 is pressed (workpiece fixing step (S40)). Thereafter, a holding step (S50) and a laser beam irradiation step (S60) are sequentially performed.

Further, as a third modified example of the first embodiment, in the workpiece fixing step (S40), the surface 11a of the workpiece 11 and the surface 21a of the resin sheet 21 are opposed to each other, and the pure water 56 is passed through the workpiece. The workpiece 11 may be pressed against the resin sheet 21 .

In this case, the pure water 56 is supplied to the front surface 21a side of the resin sheet 21 or the front surface 11a side of the workpiece 11, and the pressing plate 66 presses the back surface 11b side of the workpiece 11 to press the workpiece 11 with the resin. It is brought into close contact with the sheet 21 and fixed. As a result, it is possible to reliably avoid scratching or damage to the surface 11a without using a protective member.

By the way, as a fourth modification of the first embodiment, in the laser irradiation step (S60), so-called stealth dicing may be performed instead of laser ablation. In the stealth dicing process, a so-called modified layer is formed inside the workpiece 11 using a laser beam having a wavelength that passes through the workpiece 11 .

The laser beam has a wavelength that passes through the workpiece 11 . Laser processing conditions in the laser irradiation step (S60) are, for example, as follows.
Light source: Nd:YVO ₄ pulse laser Wavelength: 1064 nm
Average output: 2.0W
Repetition frequency: 100 kHz
Feeding speed: 400mm/sec

When stealth dicing is performed, in the workpiece fixing step (S40), the surface 11a of the workpiece 11 and the surface 21a of the resin sheet 21 face each other, and the workpiece 11 is fixed to the resin sheet with pure water 56 interposed therebetween. 21. Thereby, the workpiece 11 is brought into close contact with the resin sheet 21 and fixed. Then, in the holding step ( S<b>50 ), the back surface 29 b of the support base 29 is held by the chuck table 72 of the laser processing device 70 .

After that, the laser processing head 76a and the chuck table 72 are moved relative to each other while irradiating the laser beam from the laser processing head 76a toward the workpiece 11 so that the focal point of the laser beam is positioned inside the workpiece 11. (laser irradiation step (S60)).

A modified layer is formed along the path of this relative movement of the workpiece 11 , and finally, a modified layer is formed along all the planned dividing lines 13 . After that, the workpiece 11 is divided into a plurality of chips using a breaking device, an expanding device, or the like.

Then, as described above, the adhesiveness of the glue layer 25 is lost, and the support base 29 is peeled off from the resin sheet 21 . Next, the end of the resin sheet 21 is rolled up to separate the resin sheet 21 from the chip. Any two or more of the first, second, third, and fourth modifications of the first embodiment may be combined.

Next, a second embodiment will be described. In the second embodiment, the liquid supply step (S30) is omitted. Therefore, in the workpiece fixing step (S40), the workpiece 11 is brought into close contact with the resin sheet 21 and fixed without liquid. The workpiece fixing step (S40) of the second embodiment is performed in the same manner as the workpiece fixing step (S40) of the first embodiment. FIG. 12 is a flowchart showing the processing method of the second embodiment.

After the workpiece fixing step (S40), the back surface 11b of the workpiece 11 and the front surface 21a of the resin sheet 21 are in close contact with each other, or the space between the back surface 11b and the front surface 21a is in a vacuum state from which air is removed. becomes. 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.

Since the grooves 27 function like suction cups in this way, a workpiece unit 33 in which the workpiece 11 is fixed to the support base 29 via the resin sheet 21 is formed. The resin sheet 21 is not attached to the workpiece 11 using a glue layer, but is attached to the workpiece 11 via the irregularities formed on the surface 21a side of the base layer 23 of the resin sheet 21. .

After the holding step (S50), the workpiece 11 is processed with the laser beam L in the laser beam irradiation step (S60). Also in the second embodiment, the resin sheet 21 can be easily separated from the workpiece 11 by introducing air between the workpiece 11 and the resin sheet 21, for example. Even if the workpiece 11 is peeled off from the resin sheet 21 , the glue does not remain on the workpiece 11 .

Note that the first, second, third, and fourth modifications of the first embodiment may also be applied to the second embodiment. Moreover, any two or more of the first, second, third, and fourth modifications of the first embodiment may be combined.

By the way, in the above-described first and second embodiments, one workpiece 11 is fixed on the surface 21a side of the resin sheet unit 31, but a plurality of workpieces is fixed on the surface 21a side of the resin sheet unit 31. 11 may be fixed.

FIG. 13A is a perspective view showing a state in which a plurality of disk-shaped workpieces 11 are fixed to the resin sheet 21, and corresponds to the holding step (S50). Although three workpieces 11 are fixed to the resin sheet 21 in FIG. 13A, two or four or more workpieces 11 may be fixed to the resin sheet 21 .

Moreover, the shape of the workpiece 11 is not limited to a disk shape, and may be a rectangular shape. FIG. 13B is a perspective view showing a state in which a plurality of rectangular workpieces 11 are fixed to the resin sheet 21 in plan view, and corresponds to the holding step (S50). Two or four or more rectangular workpieces 11 may be fixed to the resin sheet 21 . Also, the resin sheet 21 and the support base 29 are not limited to the disk shape, and may be rectangular.

Next, a processing method according to the third embodiment will be described. In the processing method of the third embodiment, a metal annular frame 39 is used instead of the support base 29 (see FIG. 14). The annular frame 39 has an opening 39c whose diameter is larger than the diameter of the workpiece 11 and smaller than the diameter of the resin sheet 21 .

In the present embodiment, for the sake of convenience, one surface of the annular frame 39 to which the resin sheet 21 is attached is referred to as the surface 39a of the annular frame 39, and the other surface of the annular frame 39 opposite to the surface 39a is referred to as the annular frame 39. is referred to as the rear surface 39b of the .

The resin sheet 31 of the third embodiment has an annular adhesive layer 25 near the periphery of the other surface of the base material layer 23 (that is, the surface opposite to the surface 21a) (see FIG. 14). Note that the glue layer 25 is not limited to an 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 39c of the annular frame 39). The material of the glue layer 25 is the same as the glue of the first embodiment.

Next, a method for processing the workpiece 11 will be described. First, the back surface 21b of the resin sheet 21 is attached to the annular frame 39 so as to cover the opening 39c of the annular frame 39, thereby integrating the resin sheet 21 and the annular frame 39 (attaching step (S10)). FIG. 14 is a perspective view showing the sticking step (S10).

In the sticking step (S10), for example, the above sticking device (not shown) is used. In the attaching step (S10), first, the annular frame 39 is placed on the support table so that the surface 39a of the annular frame 39 faces upward. Next, the resin sheet 21 is arranged between the pressure roller and the annular frame 39 so that the surface on the base layer 23 side contacts the pressure roller and the surface on the glue layer 25 side faces the support table.

The resin sheet 21 is sent to the peeling unit by the feeding mechanism and the winding mechanism, and is peeled off from the release sheet by the peeling unit. After that, the resin sheet 21 is pressed (pressed) downward by a pressure roller, and adhered to a part of the annular frame 39 on the support table.

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

The resin sheet 21 is applied to the surface 39a of the annular frame 39 so that the opening 39c of the annular frame 39 is covered with the resin sheet 21 while moving the pressurized area of the resin sheet 21 pressed by the pressure roller with respect to the support table. The resin sheet 21 is attached to the annular frame 39 by bringing the back surface 21 b of the resin sheet 21 into close contact with the resin sheet 21 . Thereby, a resin sheet unit 35 composed of the resin sheet 21 and the annular frame 39 is formed.

The resin sheet 21 whose outer peripheral edge is fixed to the annular frame 39 is stretched in the radial direction of the resin sheet 21 . Therefore, compared with the case where the resin sheet 21 is not attached to the annular frame 39, it is possible to prevent the resin sheet 21 from bending due to its own weight. In addition, in the affixing step (S10) of the present embodiment, an affixing device is used, but the resin sheet 21 may be manually affixed to the annular frame 39 by an operator.

After the affixing step (S10), the cutting tool 40 is used to form unevenness on the surface 21a side of the resin sheet 21 (unevenness forming step (S20)). FIG. 15 is a partial cross-sectional side view showing the unevenness forming step (S20), and FIG. 16 is a perspective view showing the unevenness forming step (S20).

The tool cutting device 40 is the same as the tool cutting device 40 of the first embodiment, so redundant description is omitted. Although not used in the first embodiment, a plurality of clamping mechanisms (not shown) are provided on the sides of the chuck table 50 so as to protrude from the chuck table 50 . For example, four clamp mechanisms are provided at regular intervals in the circumferential direction of the chuck table 50 .

Each clamping mechanism has a frame support (not shown) on which the back surface 39b side of the annular frame 39 is placed. The frame support portion is arranged at a position lower than the holding surface 50a, and when the annular frame 39 is placed on the frame support portion, the outer peripheral portion of the resin sheet 21 and the annular frame 39 are positioned lower than the holding surface 50a. 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 rotational drive source, and the arm is rotated within a predetermined angular range by the rotational drive source. A frame holding portion (not shown) is fixed to the tip of the arm.

The frame pressing portion rotates integrally with the arm portion, and has a pressing position to press the surface 39a of the annular frame 39 placed on the frame support portion from above, and an open position to open the frame support portion. placed in either The frame retainer is placed in the open position, for example, when the annular frame 39 is placed on the frame support or when the annular frame 39 is removed from the frame support.

In the unevenness forming step (S20), first, the resin sheet unit 35 is placed on the chuck table 50 so that the back surface 21b side of the resin sheet 21 is in contact with the holding surface 50a and the back surface 39b of the annular frame 39 is in contact with the frame supporting portion. place.

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

Next, the rotational drive source of the frame supporting portion is operated to move the frame pressing portion to the pressing position. Thereby, the annular frame 39 is clamped and fixed by the clamp mechanism.

At this time, the outer peripheral portion of the resin sheet 21 and the annular frame 39 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 slopes downward from its central portion toward the outside.

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

In particular, the chuck table 50 is moved along the processing feed direction so that the resin sheet unit 35 passes directly under the spindle 44b from one end side of the bite wheel 46 in the radial direction and exits to the other end side of the bite wheel 46 in the radial direction. to move in a straight line.

As a result, the central portion of the surface 21a of the resin sheet 21 is cut with a cutting tool. More specifically, along the trajectory of the cutting tool 48, a plurality of arc-shaped cutting marks are formed on the surface 21a of the resin sheet 21. As shown in FIG. The cutting tool 48 is caught on the surface 21a side of the flexible resin sheet 21 and scratches the surface 21a side. Therefore, each arc-shaped cut mark is composed of a plurality of minute grooves 27 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 21a, 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 of the thickness of the Since the grooves 27 are concave portions with respect to the surface 21a and the surface 21a is convex portions with respect to the grooves 27, unevenness is formed on the surface 21a side of the resin sheet 21. FIG.

FIG. 17 is a perspective view showing the surface 21a side of the resin sheet 21 after the unevenness forming step (S20). 17 shows the resin sheet unit 35 removed from the chuck table 50. As shown in FIG.

In the present embodiment, unevenness is formed on the surface 21a side by cutting with a tool, but the unevenness is formed on the surface 21a side by forming scratches on the surface 21a by sandblasting the surface 21a with a mixture of abrasives in compressed air. may Further, the unevenness may be formed on the surface 21a side by etching the surface 21a by plasma etching.

In addition, while rotating a disk-shaped grinding wheel connected to the lower part of the spindle with the spindle as the rotation axis, the surface 21a is ground by grinding the surface 21a side by contacting the grinding wheel provided at the bottom of the grinding wheel to the surface 21a. You may form unevenness|corrugation in the surface 21a side by forming.

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

After the unevenness forming step (S20), a liquid supply device (not shown) supplies liquid to the surface 21a side of the resin sheet 21 on which unevenness is formed (liquid supplying step (S30)). FIG. 18 is a perspective view showing the liquid supply step.

The spinner table 58 of the liquid supply device is the same as the spinner table of the first embodiment, so redundant description will be omitted. Although not used in the first embodiment, a plurality of pendulum clamping mechanisms (not shown) are provided on the side of the spinner table 58 so as to protrude from the spinner table 58 . For example, four pendulum clamping mechanisms are provided at equal intervals in the circumferential direction of the spinner table 58 .

Each pendulum clamp mechanism has a frame support (not shown) with one end connected to the spinner table 58 . A pendulum clamp (not shown) is connected to the other end of the frame support in a rotatable manner relative to the frame support.

The pendulum clamp is in an open position where it opens onto the frame support when the spinner table 58 spins below a predetermined speed. On the other hand, when the rotational speed of the spinner table 58 is equal to or higher than the predetermined value, it is positioned at the holding position where the surface 39a of the annular frame 39 placed on the frame supporting portion is held down from above.

In the liquid supply step (S30), first, the resin sheet unit 35 is placed on the spinner table 58 so that the back surface 21b side of the resin sheet 21 is in contact with the holding surface and the back surface 39b of the annular frame 39 is in contact with the frame supporting portion. do.

At this time, the pendulum clamp is in the open position. After that, the negative pressure generated by the suction source is applied to the holding surface, and the holding surface of the spinner table 58 sucks and holds the back surface 21 b side of the resin sheet 21 .

Next, the spinner table 58 is rotated by driving the rotating mechanism. When the rotational speed of the spinner table 58 reaches or exceeds a predetermined value, the pendulum clamp moves to the pressing position to press the surface 39a of the annular frame 39 from above due to centrifugal force. As a result, the annular frame 39 is held between the pendulum clamp and the frame support.

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

After the liquid supply step (S30), the back surface 11b of the workpiece 11 and the front surface 21a of the resin sheet 21 are opposed to each other, and the workpiece 11 is pressed against the resin sheet 21 via the pure water 56 to press the workpiece 11 against the resin sheet 21. 11 is brought into close contact with the resin sheet 21 and fixed (work piece fixing step (S40)). FIG. 19 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. Since the pressing device 60 is the same as the pressing device 60 of the first embodiment, redundant description is omitted.

In the workpiece fixing step (S40), first, the resin sheet unit 35 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 21b side of the resin sheet 21 with the holding surface 62a.

Next, the workpiece 11 is placed on the front surface 21a so that the back surface 11b side of the workpiece 11 is in contact with the front surface 21a side. Then, the pressing plate 66 is lowered by the elevating mechanism, and the pressing plate 66 presses the surface 11 a of the workpiece 11 . Note that the pressing force is, for example, about several N to several tens of 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 disk-shaped pressing plate 66 for several seconds to several tens of seconds, for example, a substantially uniform force can be applied to the workpiece 11 in the Z-axis direction. Since pure water 56 is provided on the unevenness on the surface 21a side of the resin sheet 21, the back surface 11b 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 removed from the space between the back surface 11b of the workpiece 11 and the surface 21a of the resin sheet 21, and the space is filled with pure water 56, or the back surface 11b and the surface 21a 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.

Since the grooves 27 function like suction cups in this way, a workpiece unit 37 is formed in which the workpiece 11 is fixed to the annular frame 39 via the resin sheet 21 . In the workpiece unit 37, the workpiece 11 is arranged on the front surface 21a side, and the annular frame 39 is arranged on the back surface 21b side. Such an arrangement is unique to the present embodiment in which the resin sheet 21 and the workpiece 11 are not fixed via the glue layer 25 .

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

Even if the workpiece 11 is peeled off from the resin sheet 21 , the paste will not remain on the workpiece 11 . Further, the liquid on the back surface 11b side of the workpiece 11 can be removed only by drying the workpiece 11 after peeling the workpiece 11 from the resin sheet 21, and no impurities remain on the back surface 11b side of the workpiece 11. - 特許庁Another advantage is that the masking tape can be manufactured at low cost because no paste is used to adhere the workpiece 11 .

The force by which the workpiece 11 is fixed to the resin sheet 21 (or the resin sheet 21 to the workpiece 11) through the liquid is the force that the workpiece 11 is fixed to the resin sheet 21 (or the resin sheet 21) without the liquid. stronger than the force with which the sheet 21 is fixed) to the workpiece 11). Therefore, it is possible to fix the workpiece 11 and the resin sheet 21 more strongly than when the liquid is not interposed.

In addition, in the workpiece fixing step (S40), basically, the surface 11a is not scratched or damaged. , a protective member may be provided on the surface 11a. As in the first embodiment, the protective member may be a protective film such as a water-soluble resin film or a resin sheet having no adhesive layer.

By the way, in this embodiment, the pressing device 60 is used, but the operator may manually press the workpiece 11 toward the front surface 21a of the resin sheet unit 35 . Alternatively, the chuck table 62 and the pressing plate 66 may be arranged upside down, and the surface 11a side may be suction-held by the chuck table 62 so as to suspend the workpiece 11 from above.

Then, by raising the resin sheet unit 35 placed on the pressing plate 66, the resin sheet is pressed through the pure water 56 while the back surface 11b of the workpiece 11 and the front surface 21a of the resin sheet 21 face each other. 21 may be pressed against the workpiece 11 .

After the workpiece fixing step (S40), the workpiece 11 is processed. In this embodiment, in order to process the workpiece 11 with a laser beam, first, the surface 11a side (resin sheet 21 side) of the workpiece 11 is held by the holding surface 72a of the chuck table 72 provided in the laser processing device 70. Hold (holding step (S50)).

FIG. 20(A) is a partial cross-sectional side view showing the holding step (S50), and FIG. 20(B) is a perspective view showing the holding step (S50). The chuck table 72 has a porous plate 74 on the surface side.

The chuck table 72 is the same as the chuck table 72 described in the first embodiment, so redundant description will be omitted. Although not used in the first embodiment, a plurality of clamping mechanisms (not shown) are provided on the sides of the chuck table 72 . However, the clamping mechanism is the same as the clamping mechanism of the cutting tool 40, so the explanation is omitted.

In the holding step (S50), first, the workpiece unit 37 is placed on the chuck table 72 so that the back surface 21b side of the resin sheet 21 is in contact with the holding surface 72a and the back surface 39b of the annular frame 39 is in contact with the frame supporting portion. place.

At this time, the frame holding portion is arranged at the open position. After that, the negative pressure generated by the suction source is applied to the holding surface 72a, and the chuck table 72 sucks and holds the rear surface 21b side of the resin sheet 21. As shown in FIG.

Next, the rotational drive source of the frame supporting portion is operated to move the frame pressing portion to the pressing position. Thereby, the front surface 39a and the back surface 39b of the annular frame 39 are clamped and fixed by the clamp mechanism.

At this time, the outer peripheral portion of the resin sheet 21 and the annular frame 39 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 slopes downward from its central portion toward the outside.

After the holding step (S50), the workpiece 11 is irradiated with a laser beam (laser beam irradiation step (S60)). FIG. 21(A) is a partial cross-sectional side view showing the laser beam irradiation step (S60), and FIG. 21(B) is a perspective view showing the laser beam irradiation step (S60).

Since the laser processing apparatus 70 of the first embodiment is also used in the laser beam irradiation step (S60) of the third embodiment, description of the laser processing apparatus 70 is omitted.

In the laser irradiation step (S60), the laser beam L is irradiated from the laser processing head 76a toward the surface 11a of the workpiece 11 while the laser processing head 76a and the chuck table 72 are relatively moved. Thereby, the workpiece 11 is ablated along all the dividing lines 13 and divided into a plurality of chips each including the device 15 along the dividing lines 13 .

When separating the workpiece 11 from the resin sheet unit 35, first, the glue layer 25 is hardened by applying an external stimulus such as ultraviolet light or heat to the glue layer 25, thereby reducing the stickiness of the glue layer 25. disappear. Thereby, the annular frame 39 can be easily separated from the resin sheet 21 .

Next, the end of the resin sheet 21 is rolled up to introduce air between the chip and the resin sheet 21 . Thereby, the resin sheet 21 can be easily peeled off from the chip. FIG. 22 is a flowchart showing the processing method of the third embodiment.

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

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

As a result, after irregularities are formed on the surface 21a side of the resin sheet 21, the affixing step (S10) is performed, and then the liquid supply step (S30) is performed. Thereafter, a workpiece fixing step (S40), a holding step (S50) and a laser beam irradiation step (S60) are sequentially performed.

Further, as a second modification of the third embodiment, the pure water 56 may be supplied to the workpiece 11 instead of the resin sheet 21 . For example, pure water 56 is supplied to the back surface 11b side of the workpiece 11 . Then, using the pressing device 60, the back surface 11b side of the workpiece 11 is pressed against the front surface 21a side of the resin sheet 21 through the pure water 56, or the back surface 11b side of the resin sheet 21 is pressed through the pure water 56. The surface 11a side of the workpiece 11 is pressed (workpiece fixing step (S40)). Thereafter, a holding step (S50) and a laser beam irradiation step (S60) are sequentially performed.

Further, as a third modification of the third embodiment, in the workpiece fixing step (S40), the surface 11a of the workpiece 11 and the surface 21a of the resin sheet 21 are faced to each other, and the pure water 56 is passed through the workpiece. The workpiece 11 may be pressed against the resin sheet 21 .

In this case, the pure water 56 is supplied to the front surface 21a side of the resin sheet 21 or the front surface 11a side of the workpiece 11, and the pressing plate 66 presses the back surface 11b side of the workpiece 11 to press the workpiece 11 with the resin. It is brought into close contact with the sheet 21 and fixed. As a result, it is possible to reliably avoid scratching or damage to the surface 11a without using a protective member.

By the way, as a fourth modification of the third embodiment, so-called stealth dicing may be performed in the laser irradiation step (S60) instead of laser ablation.

When stealth dicing is performed, in the workpiece fixing step (S40), the surface 11a of the workpiece 11 and the surface 21a of the resin sheet 21 face each other, and the workpiece 11 is fixed to the resin sheet with pure water 56 interposed therebetween. 21. Thereby, the workpiece 11 is brought into close contact with the resin sheet 21 and fixed. Then, in the holding step ( S<b>50 ), the back surface 29 b of the support base 29 is held by the chuck table 72 of the laser processing device 70 .

After that, the laser processing head 76a and the chuck table 72 are moved relative to each other while irradiating the laser beam from the laser processing head 76a toward the workpiece 11 so that the focal point of the laser beam is positioned inside the workpiece 11. (laser irradiation step (S60)).

A modified layer is formed along the path of this relative movement of the workpiece 11 , and finally, a modified layer is formed along all the planned dividing lines 13 . After that, the workpiece 11 is divided into a plurality of chips using a breaking device, an expanding device, or the like.

Then, as described above, the adhesiveness of the glue layer 25 is lost, and the support base 29 is peeled off from the resin sheet 21 . Next, the end of the resin sheet 21 is rolled up to separate the resin sheet 21 from the chip. Any two or more of the first, second, third, and fourth modifications of the third embodiment may be combined.

Next, a fourth embodiment will be described. In the fourth embodiment, the liquid supply step (S30) is omitted. Therefore, in the workpiece fixing step (S40), the workpiece 11 is brought into close contact with the resin sheet 21 and fixed without liquid. The workpiece fixing step (S40) of the fourth embodiment is also performed in the same manner as the workpiece fixing step (S40) of the third embodiment. FIG. 23 is a flow chart showing the processing method of the fourth embodiment.

After the workpiece fixing step (S40), the back surface 11b of the workpiece 11 and the front surface 21a of the resin sheet 21 are in close contact with each other, or the space between the back surface 11b and the front surface 21a is in a vacuum state from which air is removed. becomes. 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.

Since the grooves 27 function like suction cups in this manner, a workpiece unit 37 in which the workpiece 11 is fixed to the support base 29 via the resin sheet 21 is formed. The resin sheet 21 is not attached to the workpiece 11 using a glue layer, but is attached to the workpiece 11 via the irregularities formed on the surface 21a side of the base layer 23 of the resin sheet 21. .

After a holding step (S50), the workpiece 11 is processed with a laser beam in a laser beam irradiation step (S60). Also in the fourth embodiment, the resin sheet 21 can be easily separated from the workpiece 11 by introducing air between the workpiece 11 and the resin sheet 21, for example. Even if the workpiece 11 is peeled off from the resin sheet 21 , the glue does not remain on the workpiece 11 .

Note that the first modification, the second modification, the third modification, and the fourth modification of the third embodiment may also be applied to the fourth embodiment. Moreover, any two or more of the first, second, third, and fourth modifications of the third embodiment may be combined.

By the way, in the above-described first, second, third and fourth embodiments, one workpiece 11 is fixed on the surface 21a side of the resin sheet unit 35, but the resin sheet unit 35 A plurality of workpieces 11 may be fixed on the surface 21a side of .

FIG. 24(A) is a perspective view showing a state in which a plurality of disk-shaped workpieces 11 are fixed to a resin sheet 21. FIG. 4 shows the workpiece unit 37 in a state. Although three workpieces 11 are fixed to the resin sheet 21 in FIG. 24A, two or four or more workpieces 11 may be fixed to the resin sheet 21 .

Moreover, the shape of the workpiece 11 is not limited to a disk shape, and may be a rectangular shape. FIG. 24B is a perspective view showing a state in which a plurality of rectangular workpieces 11 are fixed to the resin sheet 21 in plan view. The workpiece unit 37 is shown removed. 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 modified as appropriate without departing from the scope of the present invention. For example, according to the flow of each step of the processing method, after performing from the affixing step (S10) to the holding step (S50), instead of the laser beam irradiation step (S60), the workpiece 11 supported by the annular frame 39 may be observed, measured or conveyed.

In the observation method, measurement method, or transport method for observing, measuring, or transporting the workpiece 11 in the workpiece unit 37, if the workpiece 11 is not supported by the support base 29 or the annular frame 39, In comparison, handling of the workpiece 11 becomes easier. Of course, as described above, even if the workpiece 11 is peeled off from the resin sheet 21, the glue does not remain on the workpiece 11. FIG.

Also, the resin sheet 21 that has been used once may be reused. However, in the used resin sheet 21, the grooves 27 are widened compared to when they were formed, and it may become difficult to function as a suction cup. Therefore, when reusing the used resin sheet 21, it is more preferable to perform the unevenness forming step (S20) again to form unevenness on the surface 21a side.

REFERENCE SIGNS LIST 11 workpiece 11a front surface 11b rear surface 13 division line 15 device 21 resin sheet 21a front surface 21b rear surface 23 base material layer 25 glue layer 27 groove 29 support base 29a front surface 29b rear surface 31 resin sheet unit 33 workpiece unit 35 resin sheet Unit 37 Work piece unit 39 Annular frame 39a Front surface 39b Back surface 39c Opening 40 Tool cutting device 42 Tool cutting unit 44a Spindle housing 44b Spindle 44c Wheel mount 46 Tool wheel 48 Tool tool 48a Base 48b Cutting blade 50 Chuck table 50a Holding surface 52 Arrow 54 Nozzle 56 Pure water 58 Spinner table 60 Pressing device 62 Chuck table 62a Holding surface 64 Rod 66 Pressing plate 70 Laser processing device 72 Chuck table 72a Holding surface 74 Porous plate 76 Laser irradiation unit 76a Laser processing head 76b Imaging unit L Laser beam

Claims (5)

A processing method for processing a workpiece along a planned division line of the workpiece having a device formed on the surface side, the method comprising:
an affixing step of affixing the adhesive layer side of a resin sheet having a laminate structure of an adhesive layer and a base material layer to a support base;
an unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the adhesive layer before or after the attaching step;
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 workpiece after the attaching step and the unevenness forming step;
Pressing the workpiece against the resin sheet through the liquid, or pressing the resin sheet against the workpiece through the liquid, and fixing the workpiece in close contact with the resin sheet. an object fixing step;
a holding step of holding, with a holding surface of a chuck table, the surface of the support base to which the workpiece is fixed via the resin sheet, opposite to the resin sheet;
After the holding step, laser beam irradiation for irradiating a laser beam from a laser irradiation unit provided on the holding surface along a plurality of planned dividing lines set on the workpiece held on the chuck table. a step;
A method of processing a workpiece, comprising: A processing method for processing a workpiece along a planned division line of the workpiece having a device formed on the surface side, the method comprising:
an affixing step of affixing the adhesive layer side of a resin sheet having a laminate structure of an adhesive layer and a base material layer to a support base;
an unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the adhesive layer before or after the attaching step;
After the affixing step and the unevenness forming step, the workpiece is pressed against the resin sheet or the resin sheet is pressed against the workpiece, and the workpiece is brought into close contact with the resin sheet and fixed. a workpiece fixing step;
a holding step of holding, with a holding surface of a chuck table, the surface of the support base to which the workpiece is fixed via the resin sheet, opposite to the resin sheet;
After the holding step, laser beam irradiation for irradiating a laser beam from a laser irradiation unit provided on the holding surface along a plurality of planned dividing lines set on the workpiece held on the chuck table. a step;
A method of processing a workpiece, comprising: A processing method for processing a workpiece along a planned division line of the workpiece having a device formed on the surface side, the method comprising:
an affixing step of affixing 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 the opening;
an unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the adhesive layer before or after the attaching step;
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 workpiece after the attaching step and the unevenness forming step;
Pressing the workpiece against the resin sheet through the liquid, or pressing the resin sheet against the workpiece through the liquid, and fixing the workpiece in close contact with the resin sheet. an object fixing step;
a holding step of holding the resin sheet side of the workpiece fixed to the resin sheet by a holding surface of a chuck table;
After the holding step, laser beam irradiation for irradiating a laser beam from a laser irradiation unit provided on the holding surface along a plurality of planned dividing lines set on the workpiece held on the chuck table. a step;
A method of processing a workpiece, comprising: A processing method for processing a workpiece along a planned division line of the workpiece having a device formed on the surface side, the method comprising:
an affixing step of affixing 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 the opening;
an unevenness forming step of forming unevenness on the surface side of the base material layer opposite to the adhesive layer before or after the attaching step;
After the affixing step and the unevenness forming step, the workpiece is pressed against the resin sheet or the resin sheet is pressed against the workpiece, and the workpiece is brought into close contact with the resin sheet and fixed. a workpiece fixing step;
a holding step of holding the resin sheet side of the workpiece fixed to the resin sheet by a holding surface of a chuck table;
After the holding step, laser beam irradiation for irradiating a laser beam from a laser irradiation unit provided on the holding surface along a plurality of planned dividing lines set on the workpiece held on the chuck table. a step;
A method of processing a workpiece, comprising: 4. The method of processing a workpiece according to claim 1, wherein said liquid is pure water.

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