JP6782617B2 - How to fix the work piece and how to process the work piece - Google Patents

Description

The present invention relates to a method for fixing a work piece and a method for processing a work piece.

Conventionally, when processing various plate-shaped workpieces such as semiconductor wafers and package substrates, a technique is known in which the workpiece is supported by an adhesive tape such as a dicing tape or a grinding tape. For example, Patent Document 1 discloses a technique of attaching and fixing a wafer, which is a work piece, to an adhesive tape attached to an annular frame. By fixing the work piece to the adhesive tape in this way, the work piece is prevented from directly touching the chuck table or the like of the processing device to prevent damage to the work piece, and the work piece is divided into a plurality of chips by processing. The work piece is integrally transported while being attached to the adhesive tape.

Further, as a method for processing an workpiece, a technique using a laser processing device, a cutting device, or a grinding device is known. For example, in Patent Document 2, a process of irradiating a laser beam by aligning a condensing point with the inside of a work object along a planned cutting line (scheduled division line) to form a modified region inside the work object. The method is disclosed. In this processing method, a region serving as a base point for cutting (division) is formed by a modified region, and then, for example, an artificial force is applied to the object to be processed to cut (divide) the object to be processed. Further, in Patent Document 3, in a state where the wafer as a work piece is supported by the adhesive tape, the wafer is processed for division along the planned division line, and then the adhesive tape is expanded to form the wafer. A processing method for dividing a wafer by applying an external force is disclosed. Examples of the processing for division include cutting processing, forming processing of a altered layer (modified layer) by irradiation with laser light, and ablation processing by irradiation with laser light.

Japanese Unexamined Patent Publication No. 09-027543 Japanese Patent No. 3408805 JP-A-2010-206136

However, since the adhesive strength of the adhesive tapes described in Patent Documents 1 and 3 decreases with use, repeated use is restricted, and the cost of replacement with a new one is increased. In addition, when the adhesive tape is peeled off from the work piece after processing the work piece, the adhesive material contained in the work piece may remain on the sticking surface of the work piece, which takes time and effort to clean the work piece. It ends up. In order to prevent the adhesive material from remaining on the work piece, it is conceivable to use, for example, an adhesive tape containing an ultraviolet curable adhesive material, but such an adhesive tape is generally expensive and further costly. It will lead to an increase.

The present invention has been made in view of the above, and an object of the present invention is to process a work piece while supporting the work piece by a cheaper method without using an adhesive tape.

To solve the above problems and achieve the object, the present invention is to be processed to secure the sheet to the workpiece Li Kui surface that includes a dividing lines formed in a grid pattern, such an insulator or a semiconductor A method of fixing an object, in which the outer peripheral edge of a sheet made of an insulator is fixed to an annular frame, a frame with sheet forming step for forming a frame with a sheet, and positive and negative electrodes are installed at intervals in the plane direction. A mounting step of mounting the workpiece on the electrostatic chuck table via the sheet of the frame with the sheet, and after performing the mounting step, a voltage is applied to the electrodes of the electrostatic chuck table. A voltage application step of generating polarization in each of the sheet and the workpiece to be attracted and integrated, and a frame with the sheet integrated from the electrostatic chuck table after performing the voltage application step. The electrostatic chuck table includes a peeling step for peeling the workpiece together , and the distance between the adjacent positive and negative electrodes is set to be narrower than the distance between the planned division lines , and the electrostatic chuck table is separated from the electrostatic chuck table. Even if it is peeled off, the sheet of the frame with the sheet and the workpiece are maintained in close contact with each other by polarization.

In order to solve the above-mentioned problems and achieve the object, the present invention is a method for processing a work piece, which is made of an insulator or a semiconductor and has a grid-like division schedule line formed on the surface thereof. A fixing step of fixing the object to the opening of the annular frame with a sheet made of an insulator, and after performing the fixing step, the permeability to the workpiece is made along the planned division line of the workpiece. After performing the modified layer forming step of irradiating a laser beam having a wavelength to form a modified layer along the planned division line inside the workpiece and the modified layer forming step, the workpiece The work piece is divided into individual chips along the modified layer by applying an external force to the work piece, and the fixing step is a method for fixing the work piece.

Further, in the dividing step, it is preferable that the sheet is expanded in the surface direction to apply an external force.

The method for fixing the workpiece and the method for processing the workpiece according to the present invention use an adhesive tape by adsorbing the sheet and the workpiece by polarization (dielectric polarization) using an electrostatic chuck table. After fixing the work piece to the annular frame together with the sheet, the work piece is processed. As a result, unlike the adhesive tape, the adhesive strength does not decrease with each use, and the number of times the sheet is repeatedly used can be increased. Further, since the sheet does not need to contain an adhesive material, a cheaper sheet can be used as compared with the conventional adhesive tape. Further, there is no possibility that the adhesive material remains on the work piece, and the step for cleaning the adhesive material can be omitted. Therefore, in the method for fixing the work piece and the method for processing the work piece according to the present invention, the work piece is processed while supporting the work piece by a cheaper method without using an adhesive tape. It has the effect of being able to.

FIG. 1 is a perspective view showing a wafer as a work piece to be targeted by a method of fixing a work piece according to an embodiment and a method of processing a work piece. FIG. 2 is a flowchart showing a method of fixing the workpiece according to the embodiment. FIG. 3 is a perspective view showing how the frame-attached frame forming step is performed. FIG. 4 is a perspective view showing a frame with a sheet formed by the frame forming step with a sheet. FIG. 5 is a perspective view showing how the mounting step is performed. FIG. 6 is a cross-sectional view showing a state in which the wafer and the frame with the sheet are mounted on the electrostatic chuck table by the mounting step. FIG. 7 is a cross-sectional view showing how the peeling step is performed. FIG. 8 is a flowchart showing a processing method of the workpiece according to the embodiment. FIG. 9 is a cross-sectional view showing how the modified layer forming step is carried out. FIG. 10 is a cross-sectional view showing a state in which the wafer is fixed to the dividing device during the dividing step. FIG. 11 is a cross-sectional view showing a wafer divided into a plurality of device chips by the division step.

An embodiment (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Further, the configurations described below can be combined as appropriate. In addition, various omissions, substitutions or changes of the configuration can be made without departing from the gist of the present invention.

FIG. 1 is a perspective view showing a wafer as a workpiece to be the target of the method of fixing the workpiece according to the embodiment and the method of processing the workpiece. In the present embodiment, the wafer W shown in FIG. 1 is a disk-shaped semiconductor wafer or an optical device wafer using silicon, sapphire, gallium, or the like as a base material. The work piece is not limited to these, and may be an insulator or a semiconductor. As shown in FIG. 1, the wafer W has a plurality of scheduled division lines L formed in a grid pattern on the surface WS. In the wafer W, the device D is formed in each region partitioned by a plurality of scheduled division lines L where the surface WS intersects. As the device D, an IC (Integrated Circuit), an LSI (Large Scale Integration), a MEMS (Micro Electro Mechanical Systems) and the like are formed in each region. The surface WS of WEHA W is a low dielectric constant insulator film (Low-k film) composed of an inorganic film such as SiOF and BSG (SiOB) and an organic film which is a polymer film such as polyimide and parylene. Surface films such as are laminated (not shown).

The method of fixing the workpiece according to the embodiment will be described. The method of fixing the work piece according to the embodiment is a method of fixing the sheet as a support member to the work piece made of an insulator or a semiconductor during the processing of the work piece. The processing of the workpiece will be described later. For example, cutting using a cutting device, laser ablation using a laser machining device, or a laser to form a modified layer on the workpiece, and using the modified layer as a base point. Examples thereof include processing for dividing a work piece.

FIG. 2 is a flowchart showing a method of fixing the workpiece according to the embodiment. As shown in FIG. 2, the method for fixing the workpiece according to the embodiment includes a frame forming step ST11 with a sheet, a mounting step ST12, a voltage application step ST13, and a peeling step ST14. Hereinafter, the contents of each step will be described with reference to the drawings. FIG. 3 is a perspective view showing how the frame-attached frame forming step is performed, FIG. 4 is a perspective view showing the sheet-attached frame formed by the sheet-attached frame forming step, and FIG. 5 is a mounting step. 6 is a perspective view showing a state in which a wafer and a frame with a sheet are mounted on an electrostatic chuck table by a mounting step, and FIG. 7 is a cross-sectional view showing a state in which a wafer and a frame with a sheet are mounted. It is sectional drawing which shows the state of doing.

The sheet-attached frame forming step ST11 is a step of fixing the outer peripheral edge 10a of the sheet 10 made of an insulator to the annular frame F to form the sheet-attached frame FS. The sheet 10 can be formed by using various materials as long as it is an insulator. The sheet 10 is a resin sheet such as a polyethylene film, a nylon sheet, a wrap film, or a silicon sheet. The sheet 10 is formed in a circular shape as shown in FIG. The outer diameter of the sheet 10 is smaller than the outer diameter of the annular frame F and larger than the inner diameter of the annular frame F. The sheet 10 may have a rectangular shape or the like as long as it can be fixed to the annular frame F. Further, the sheet 10 is preferably as thin as long as it can secure a thickness that can be handled during transportation, each processing step, and the like, and is preferably 100 μm or less, for example.

In the present embodiment, the sheet 10 is coated with the adhesive 10b on the outer peripheral edge 10a. In the sheet-attached frame forming step ST11, as shown in FIG. 3, the outer peripheral edge 10a coated with the adhesive 10b of the sheet 10 is attached to the annular frame F, and the sheet 10 and the annular frame F are integrated. As a result, the frame FS with a sheet shown in FIG. 4 is formed. Instead of the adhesive 10b, the sheet 10 may be attached to the annular frame F using double-sided tape or the like. Further, the annular frame F may be provided with a holding portion (for example, a double ring) capable of sandwiching and holding the outer peripheral edge 10a of the seat 10, and the seat 10 may be attached to the annular frame F by the holding portion.

The mounting step ST12 is a step of mounting a wafer W, which is a workpiece, on an electrostatic chuck table 20 in which positive and negative electrodes 23 are installed at intervals in the plane direction via a sheet 10 of a frame FS with a sheet. Is. The electrostatic chuck table 20 is a gradient type electrostatic chuck device that generates an electrostatic force (gradient force) with an object mounted on the mounting surface 21a by applying a voltage to the positive and negative electrodes 23. .. As shown in FIGS. 5 and 6, the electrostatic chuck table 20 includes a substrate 21, a clamp portion 22, and positive and negative electrodes 23.

The substrate 21 is formed of silicon, glass, quartz, ceramics, or the like in a disk shape. An insulating layer 21b made of a resin material is formed on the surface of the substrate 21. The surface of the insulating layer 21b forms a mounting surface 21a of the electrostatic chuck table 20. Further, positive and negative electrodes 23 are provided inside the insulating layer 21b. A plurality of clamp portions 22 (four in this embodiment) are provided around the substrate 21 and at a position lower than the mounting surface 21a at intervals of 90 ° from each other. The clamp portion 22 is driven by an air actuator (not shown).

The positive and negative electrodes 23 have a plurality of positive electrode electrodes 23a and a plurality of negative electrode electrodes 23b. As shown in FIG. 6, the plurality of positive electrode electrodes 23a and the plurality of negative electrode electrodes 23b are spaced apart from each other in the surface direction of the mounting surface 21a (in the example shown in the present embodiment, the left-right direction in FIG. 6). The positive electrode 23a and the negative electrode 23b are arranged in parallel in this order. The positive electrode 23a and the negative electrode 23b extend along a direction orthogonal to the direction in which they are arranged in parallel (front view direction in FIG. 6). The positive electrode 23a and the negative electrode 23b may extend straight or may extend while being curved. Further, each positive electrode 23a and each negative electrode 23b have a comb-teeth shape (a shape in which a wide portion and a narrow portion are continuous at predetermined intervals), and the other electrode is placed between the narrow portions of one electrode. The wide portion may be arranged. The electrostatic chuck table 20 has a positive electrode terminal portion electrically connected to the plurality of positive electrode electrodes 23a and a negative electrode terminal portion electrically connected to the plurality of negative electrode electrodes 23b. The positive and negative electrode terminals may be formed on either the side surface or the back surface of the substrate 21.

In the mounting step ST12, as shown by the white arrow in FIG. 5, the back surface WR side of the wafer W to be processed is mounted on the sheet 10 of the frame FS with a sheet, and the frame FS with a sheet is electrostatically chucked. It is placed on the mounting surface 21a of the table 20. After that, the clamp portion 22 is driven by an air actuator (not shown), the annular frame F of the frame with seat FS is sandwiched by the clamp portion 22, and the frame FS with seat is fixed to the electrostatic chuck table 20 as shown in FIG. .. Either the wafer W is placed on the sheet 10, the frame FS with the sheet is placed on the mounting surface 21a of the electrostatic chuck table 20, and the annular frame F is sandwiched by the clamp portion 22 first. You may go.

In the voltage application step ST13, after the mounting step ST12 is performed, a voltage is applied to the electrode 23 of the electrostatic chuck table 20 to generate polarization in each of the sheet 10 and the wafer W as the workpiece, and they are integrated while being adsorbed. It is a step to make it. Specifically, in the voltage application step ST13, a positive voltage is applied to the positive electrode 23a and a negative voltage is applied to the negative electrode 23b from a power feeding device (not shown) via the positive and negative electrode terminals for a predetermined time. Apply. As a result, dielectric polarization is generated in the sheet 10 and the wafer W, and positive and negative charges of each other are attracted between the positive electrode 23a and the negative electrode 23b, the sheet 10 and the wafer W, so that an electrostatic force (gradient force) is generated. Occur. When the thickness of the sheet 10 is 100 μm or less, dielectric polarization can be satisfactorily generated in the wafer W even through the sheet 10. Due to this electrostatic force, the sheet 10 and the wafer W are attracted and integrated. As a result, the wafer W is fixed by the sheet 10 (via the sheet 10) to the opening F1 of the annular frame F.

Here, as shown in FIG. 6, in the electrostatic chuck table 20 of the present embodiment, the adjacent positive and negative electrodes 23, that is, the distance A2 between the positive electrode 23a and the negative electrode 23b adjacent to each other are adjacent to each other in the wafer W. It is set narrower than the interval A1 of the scheduled division line L. The interval A1 of the scheduled division lines L is a distance connecting the centers of the scheduled division lines L adjacent to each other. When the positive electrode 23a and the negative electrode 23b are comb-shaped, the distance A2 between the positive electrode 23a and the negative electrode 23b adjacent to each other is the distance between the adjacent wide portion and the narrow portion. As a result, at least a part of both the positive electrode 23a and the negative electrode 23b is provided in the range of the interval A1 of the planned division line L, that is, in the entire region that becomes each device chip DT (see FIG. 11) in the subsequent processing step. It will be easier to place. In the present embodiment, as shown in FIG. 6, a part of the positive electrode 23a and the negative electrode 23b is arranged within the range of the interval A1 of all the scheduled division lines L. As a result, dielectric polarization can be generated for each region that will later become each device chip DT, and the state in which each divided device chip DT is adsorbed on the sheet 10 can be maintained.

The peeling step ST14 is a step of peeling both the frame FS with a sheet integrated from the electrostatic chuck table 20 and the wafer W as a workpiece after performing the voltage application step ST13. In the peeling step ST14, as shown in FIG. 7, the clamp portion 22 is driven by an air actuator (not shown) to release the sandwiching of the annular frame F by the clamp portion 22, and the wafer W and the frame FS with a sheet are electrostatically chucked. It is lifted from the mounting surface 21a of the table 20 and peeled off.

In the method for fixing the workpiece according to the present embodiment, since the insulator or semiconductor wafer W and the insulator sheet 10 are adsorbed by dielectric polarization, as compared with the case where a conductive workpiece or sheet is used, The polarized state is easily maintained. Therefore, even if the wafer W and the frame FS with a sheet are separated from the electrostatic chuck table 20, the sheet 10 of the frame FS with a sheet and the wafer W are in close contact (adsorption) for a predetermined period (for example, 1 to 1) due to dielectric polarization. It will be maintained for about 2 weeks). Further, by adjusting the shape and size of the positive electrode 23a and the negative electrode 23b, the size of the distance A2 between the positive electrode 23a and the negative electrode 23b adjacent to each other, and the like, the wafer W and the sheet 10 are brought into close contact (adsorption). Can be maintained well. As a result, the wafer W can be maintained in a state of being supported by the sheet 10 and the subsequent processing step can be carried out. That is, damage is prevented by preventing the wafer W from directly touching the chuck table or the like of each device, and the wafer W divided into a plurality of device chip DTs by processing is integrally conveyed while being supported by the sheet 10. be able to.

Next, the processing method of the workpiece according to the embodiment will be described with reference to the drawings. FIG. 8 is a flowchart showing a processing method of the workpiece according to the embodiment. As shown in the figure, the processing method of the workpiece according to the embodiment includes a fixing step ST21, a modified layer forming step ST22, and a dividing step ST23. Hereinafter, the contents of each step will be described with reference to the drawings. FIG. 9 is a cross-sectional view showing how the modified layer forming step is carried out, FIG. 10 is a cross-sectional view showing a state in which the wafer is fixed to the dividing device at the time of the dividing step, and FIG. It is sectional drawing which shows the wafer divided into the device chip of.

The fixing step ST21 is a step of fixing the wafer W, which is a work piece, to the opening F1 of the annular frame F by a sheet 10 made of an insulator. The fixing step ST21 implements the method for fixing the workpiece according to the above-described embodiment. That is, by carrying out the frame forming step ST11 with a sheet, the mounting step ST12, the voltage application step ST13, and the peeling step ST14 shown in FIG. 2, the sheet 10 of the frame FS with a sheet and the wafer W are integrated, and the sheet 10 is integrated. The wafer W is fixed to the opening F1 of the annular frame F via the above.

After performing the fixing step ST21, the modified layer forming step ST22 irradiates the wafer W with a laser beam LS having a wavelength that is transparent to the wafer W along the planned division line L of the wafer W, and divides the inside of the wafer W. This is a step of forming the modified layer K along the planned line L. In the modified layer forming step ST22, first, the wafer W is placed on the porous holding surface 31a of the chuck table 31 of the laser processing apparatus 30 that irradiates the wafer W with the laser beam LS via the sheet 10 of the frame FS with a sheet. Place. Next, the holding surface 31a is sucked by a vacuum suction source connected to the chuck table 31 via a vacuum suction path (not shown), and the wafer W is sucked and held by the holding surface 31a of the chuck table 31 via the sheet 10. .. Further, the clamp portion 32 provided around the chuck table 31 and at a position lower than the holding surface 31a is driven by an air actuator (not shown), and the annular frame F is sandwiched and fixed by the clamp portion 32. Then, the wafer W is aligned based on the image acquired by the imaging means (not shown) of the laser processing apparatus 30. After that, while the chuck table 31 and the laser beam irradiating means 33 are relatively moved, as shown in FIG. 9, a laser beam LS having a wavelength that is transparent to the wafer W is aligned with the inside of the wafer W. And irradiate along the scheduled division line L. As a result, the modified layer K along the planned division line L is formed inside the wafer W.

The division step ST23 is a step of applying an external force to the wafer W after carrying out the modified layer forming step ST22 to divide the wafer W into individual device chip DTs along the modified layer K. In the present embodiment, the division step ST23 expands the sheet 10 in the surface direction to apply an external force. Specifically, the wafer W is conveyed to the dividing device 40 together with the frame FS with a sheet, and the annular frame F is sandwiched and fixed in the clamp portion 41 of the dividing device 40. Then, as shown in FIG. 10, after the pressing member 42 of the dividing device 40 is brought into contact with the sheet 10, the pressing member 42 is raised as shown in FIG. 11 to expand the sheet 10 in the plane direction. As a result, an external force is applied to the wafer W in the surface direction of the sheet 10, that is, in the radial direction of the wafer W, and the wafer W is individually formed with the modified layer K formed along the planned division line L as a base point. Divided into device chip DT.

After that, the divided device chip DT is conveyed to the next process while being adsorbed on the sheet 10. When each step is completed and each device chip DT is peeled from the sheet 10, for example, if a plurality of device chip DTs are sucked using a vacuum pad, the plurality of device chip DTs can be peeled from the sheet 10 at once. Can be done.

As described above, in the method for fixing the workpiece and the method for processing the workpiece according to the embodiment, the sheet 10 and the wafer W as the workpiece are polarized (dielectric polarization) using the electrostatic chuck table 20. ), The wafer W is fixed to the annular frame F together with the sheet 10 without using an adhesive tape, and then the wafer W is processed. As a result, unlike the adhesive tape, the adhesive strength does not decrease each time the sheet is used, and the number of times the sheet 10 is repeatedly used can be increased. Further, since the sheet 10 does not need to contain an adhesive material, a cheaper sheet can be used as compared with the conventional adhesive tape. Further, there is no possibility that the adhesive material remains on the workpiece (device chip DT in the present embodiment), and the step of cleaning the adhesive material can be omitted. Therefore, according to the method for fixing the workpiece and the method for processing the workpiece according to the embodiment, the wafer W (workpiece) is supported by a cheaper method without using an adhesive tape, and the workpiece is processed. The object can be processed.

Further, the wafer W, which is a work piece, has a planned division line L formed in a grid pattern on the surface, and the electrostatic chuck table 20 has adjacent positive and negative electrodes 23 (positive electrode 23a and negative electrode 23b adjacent to each other). The interval A2 is set to be narrower than the interval A1 of the scheduled division line L. As a result, dielectric polarization can be satisfactorily generated in each device chip DT with respect to the wafer W divided into a plurality of device chip DTs along the scheduled division line L. As a result, even after the wafer W is divided into the device chip DTs, the state of being firmly adsorbed on the sheet 10 can be maintained. Therefore, in the subsequent process of the division step (in this embodiment, the division step ST23), It is possible to carry out transportation and each process easily and stably.

In the method for fixing the workpiece according to the embodiment, in the frame forming step ST11 with a sheet, the sheet 10 and the annular frame F are fixed by an adhesive, but the fixing means between the sheet 10 and the annular frame F is , Not limited to this. For example, the annular frame F may be an insulator formed of a resin material or the like, and the sheet 10 and the annular frame F may be integrally fixed by dielectric polarization by the electrostatic chuck table 20. That is, the sheet-attached frame forming step ST11 and the mounting step ST12 are integrated steps, and in the voltage application step ST13, all of the sheet 10, the annular frame F and the wafer W are integrally fixed by dielectric polarization by the electrostatic chuck table 20. You may.

Further, the method for processing the workpiece according to the embodiment is a fixing step ST21 for fixing the wafer W to the opening F1 of the annular frame F by a sheet 10 made of an insulator, and a fixing step ST21, and then dividing the wafer W. With the modified layer forming step ST22, which irradiates the wafer W with a laser beam LS having a wavelength that is transparent along the planned line L and forms the modified layer K along the planned split line L inside the wafer W. After carrying out the modified layer forming step ST22, the fixing step ST21 includes a dividing step ST23 in which an external force is applied to the wafer W and the wafer W is divided into individual device chip DTs along the modified layer K. , Is a method of fixing a work piece according to an embodiment.

In this way, according to the processing process of forming the modified layer K along the scheduled division line L inside the wafer W and dividing the wafer W into individual device chip DTs along the modified layer K, for example, cutting. The load applied to the wafer W can be reduced as compared with the case where the wafer W is divided by processing or laser ablation processing. Moreover, it is not necessary to use a cutting fluid or the like during the processing. Therefore, even by the method of fixing the workpiece of the present invention in which the wafer W and the sheet 10 are maintained to be attracted by the electrostatic force due to the dielectric polarization, the wafer W (device chip DT) and the sheet 10 are peeled off during the processing. It is suitable for the application of the present invention because there is no risk of static electricity. If there is no risk of the wafer W and the sheet 10 peeling off during the processing, the wafer W and the sheet 10 are subjected to the fixing step ST21 and then the wafer is processed by cutting using a cutting device or laser ablation using a laser processing device. A processing process may be performed in which a groove along the planned division line L is formed in W and the wafer W is divided into a plurality of chips.

Further, in the division step ST23, the sheet 10 is expanded in the surface direction to apply an external force. According to the method of fixing the work piece (fixing step ST21) according to the present embodiment, the degree of freedom in selecting the material is improved as compared with the conventional adhesive tape, so that the sheet 10 is repeatedly made of a nylon sheet, a wrap film, a silicon sheet or the like. A stretchable material can be used. Therefore, even when a method of applying an external force to the wafer W by expanding the sheet 10 in the surface direction is used as in the division step ST23, the sheet 10 can be used over and over again without deteriorating. It becomes. In addition, after performing the division step ST23 according to the elasticity of the material of the sheet 10, the portion pressed by the pressing member 42 of the sheet 10 is heat-treated by, for example, infrared irradiation, so that the slack caused by the pressing is performed. May be processed to shrink. Further, after performing the modified layer forming step ST22, an external force may be applied to the wafer W by pressing the wafer W itself through the sheet 10 as the dividing step ST23.

10 Sheet 10a Outer peripheral edge 10b Adhesive 20 Electrostatic chuck table 21 Substrate 21a Mounting surface 21b Insulation layer 22 Clamp part 23 Electrode 23a Positive electrode 23b Negative electrode 30 Laser processing device 31 Chuck table 31a Holding surface 32 Clamp part 33 Laser beam irradiation means 40 Dividing device 41 Clamping part 42 Pressing member A1, A2 Spacing D device DT Device chip F Circular frame F1 Opening FS Frame with sheet K Modified layer L Scheduled division line LS Laser beam W Waha WS Front surface WR Back surface

Claims (3)

A method of fixing a workpiece to fix the sheet to the workpiece that includes a dividing lines formed in a lattice pattern on Li Kui surfaces such an insulator or a semiconductor,
A frame forming step with a sheet, in which the outer peripheral edge of a sheet made of an insulator is fixed to an annular frame to form a frame with a sheet,
A mounting step in which the workpiece is mounted via the sheet of the frame with the sheet on an electrostatic chuck table in which positive and negative electrodes are installed at intervals in the plane direction.
After performing the mounting step, a voltage is applied to the electrodes of the electrostatic chuck table to generate polarization in each of the sheet and the workpiece, and the voltage application step is integrated while adsorbing the sheet.
After performing the voltage application step, the frame with the sheet integrated from the electrostatic chuck table and the peeling step for peeling the workpiece together are provided.
In the electrostatic chuck table, the distance between the adjacent positive and negative electrodes is set to be narrower than the distance between the planned division lines, and even if the electrostatic chuck table is separated from the electrostatic chuck table, the sheet and the sheet of the frame with the sheet are polarized. A method for fixing a work piece, which comprises maintaining close contact with the work piece. A method for processing a work piece, which is made of an insulator or a semiconductor and has a grid-like division line formed on the surface.
A fixing step that fixes the work piece to the opening of the annular frame with a sheet of insulation,
After performing the fixing step, the work piece is irradiated with a laser beam having a wavelength having a transmittance along the work piece, and the work piece is inside the work piece. The modified layer formation step of forming the modified layer along the
After carrying out the modified layer forming step, an external force is applied to the work piece, and the work piece is divided into individual chips along the modified layer.
The fixing step is a processing method of a workpiece, which is a method of fixing a workpiece according to claim 1 Symbol placement. The method for processing a workpiece according to claim 2 , wherein the division step expands the sheet in the surface direction to apply an external force.

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