Processing method for plate-shaped materials

Abstract

To provide a processing method for a plate-shaped object with high productivity without requiring maintenance of a frame that supports the plate-shaped object that serves as a workpiece.SOLUTION: A processing method for a plate-shaped object includes a plate-shaped object support step for disposing a plate-shaped object on an upper surface of a sheet having an area larger than the plate-shaped object through a liquid resin and supporting the plate-shaped object by only the solidified liquid resin and the sheet, a processing step for making the plate-shaped object to be divided into a plurality of chips, and a pick-up step for picking up the chips from the sheet.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for processing a plate-like object.

Background Art

[0002] A wafer on which devices such as ICs and LSIs are formed on a surface partitioned by a dicing line is divided into individual device chips by a dicing device or a laser processing device and used in electrical devices such as mobile phones and personal computers.

[0003] After the above-described wafer is divided into individual device chips, in order to perform a pickup process while maintaining the form of the wafer, conventionally, for example, as shown in FIG.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the processing apparatus described in Patent Documents 1 to 3 mentioned above, the frame F that supports the wafer 10 is reused as described above. Therefore, after processing the wafer 10 supported by the frame F, the adhesive tape T is removed from the frame F, the frame is collected, washed to remove any attached processing debris and adhesive, and then stored in a designated place for maintenance until it is used for the next processing. However, this maintenance is time-consuming, which results in poor productivity.

[0006] This invention has been made in view of the above facts, and its main technical problem is to provide a method for processing plate-like materials that does not require maintenance of the frame supporting the plate-like material as a workpiece, and that offers high productivity. [Means for solving the problem]

[0007] To solve the above-mentioned main technical problems, the present invention provides a method for processing a plate-shaped object, comprising: a plate-shaped object support step in which the plate-shaped object is placed on the upper surface of a sheet having a larger area than the plate-shaped object via a liquid resin, and the plate-shaped object is supported only by the solidified liquid resin and the sheet; a processing step in which the plate-shaped object is processed to divide it into a plurality of chips; and a pickup step in which the chips are picked up from the sheet. The process also includes an expansion step of clamping the outer circumference of the sheet and expanding the sheet to widen the gap between the chips, The sheet provides a method for processing a plate-like object having a pair of parallel, straight edges facing each other across the center.

[0008] The P Preferably, the process includes a disposal step for discarding the sheet after the pickup step.

[0009] The processing step is preferably selected from one of the following: cutting, in which a cutting blade is positioned in the region of the plate-shaped material to be divided and cutting is performed; ablation, in which a laser beam of a wavelength absorbed by the plate-shaped material is irradiated into the region of the plate-shaped material to be divided to form grooves by ablation processing; or a modified layer formation step, in which a focal point of a laser beam of a wavelength transmitted by the plate-shaped material is positioned inside the region of the plate-shaped material to be divided and irradiated to form a modified layer.

[0010] The plate-like object is a wafer having a surface partitioned by lines indicating a division of multiple devices, and it is preferable that the surface or back surface of the wafer is disposed on the upper surface of a sheet via a liquid resin, and the sheet is preferably made of a polyester-based or polyethylene-based material. Furthermore, it is preferable that the liquid resin is one of an acrylic-based, rubber-based, silicone-based, or epoxy-based material. [Effects of the Invention]

[0011] The present invention provides a method for processing a plate-like object, comprising: a plate-like object support step in which the plate-like object is placed on the upper surface of a sheet having a larger area than the plate-like object via a liquid resin, and the plate-like object is supported only by the solidified liquid resin and the sheet; a processing step in which the plate-like object is processed to divide it into a plurality of chips; and a pickup step in which the chips are picked up from the sheet. The process also includes an expansion step of clamping the outer circumference of the sheet and expanding the sheet to widen the gap between the chips, Because the sheet has a pair of parallel, straight edges facing each other across the center, it eliminates the need for conventional frames, thus reducing the maintenance required to reuse the frames and improving productivity. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view of a dicing apparatus applied to the plate-shaped material processing method of this embodiment. [Figure 2] (a) to (d) are perspective views showing embodiments and modified examples of the sheet of the present invention. [Figure 3] This is a perspective view showing how liquid resin is supplied during the plate-shaped object support process. [Figure 4] Figure 3 is a perspective view showing how wafers are arranged on a sheet during the plate-like object support process. [Figure 5] This is a perspective view showing an embodiment of a cutting process performed as a manufacturing step. [Figure 6] (a) A perspective view showing an embodiment of the extension process, and (b) A perspective view showing an embodiment of the pickup process. [Figure 7] It is a perspective view showing a mode in which a wafer is supported by an annular frame via an adhesive tape in the past.

Embodiments for Carrying out the Invention

[0013] Hereinafter, embodiments of a method for processing a plate-shaped object configured based on the present invention will be described in detail with reference to the accompanying drawings.

[0014] FIG. 1 shows an overall perspective view of a dicing device 1 suitable for the method for processing a plate-shaped object according to the present embodiment. The dicing device 1 is a device for cutting a circular wafer 10 which is a plate-shaped object. The wafer 10 is the same wafer as the wafer 10 described based on FIG. 7, and is a semiconductor wafer made of, for example, silicon (Si) formed on a surface 10a partitioned by a plurality of device dividing lines 14.

[0015] The dicing device 1 includes a device housing 2. The wafer 10 which is the workpiece in the present embodiment is disposed via a liquid resin P on a sheet S by carrying out a plate-shaped object supporting step which will be described in detail later, and is supported only by the solidified liquid resin P and the sheet S. A plurality of the wafers 10 are accommodated in a cassette 3 (shown by a two-dot chain line) carried into the device housing 2. The wafer 10 accommodated in the cassette 3 is sandwiched by the sheet S by a carry-in / carry-out means 4, and is transported onto a temporary placement table 5 by the carry-in / carry-out means 4 moving in the Y-axis direction.

[0016] The wafer 10 transported onto the temporary placement table 5 is adsorbed by a transport means 6, and by the turning operation of the transport means 6, is transported to a chuck table 7 positioned in a carry-in / carry-out area for carrying in and out the wafer 10, and is placed and suction-held on a suction chuck 7a of the chuck table 7. Four clamps 7b for sandwiching and fixing the sheet S supporting the wafer 10 are arranged at equal intervals on the outer periphery of the chuck table 7.

[0017] Alignment means 8 and cutting means 9 are arranged in the direction of movement of the chuck table 7 in the X-axis direction. Inside the device housing 2 are an X-axis moving means (not shown) for feeding the chuck table 7 in the X-axis direction, a Y-axis moving means (not shown) for indexing and feeding the cutting blade 9a of the cutting means 9 in the Y-axis direction, and a Z-axis moving means (not shown) for raising and lowering the cutting blade 9a to cut it out. The wafer 10 held by the chuck table 7 is moved in the X-axis direction by the X-axis moving means, and the wafer 10 is imaged by the alignment means 8 which has a camera function, thereby detecting the area of ​​the wafer 10 to be cut. Cutting by the cutting means 9 in this embodiment is carried out as follows.

[0018] By the alignment means 8, the planned division line 14 is detected as the area to be processed, the planned division line 14 is aligned in the X-axis direction, and the alignment between the planned division line 14 and the cutting blade 9a of the cutting means 9 is performed. The chuck table 7 is moved in the X-axis direction so that the planned division line 14 is positioned in the processing area directly below the cutting blade 9a of the cutting means 9. Next, the cutting blade 9a is rotated and lowered by the Z-axis moving means to perform a cutting feed, and the chuck table 7 is fed in the X-axis direction for processing, so that the planned division line 14 is cut and a cutting groove is formed linearly. If the planned division line 14 is cut linearly, the cutting blade 9a is raised, the Y-axis feeding means is operated, and an indexing feed is performed by the interval to the adjacent planned division line 14 in the Y-axis direction. The cutting blade 9a is fed for cutting in the same manner as described above to cut the planned division line 14. By repeating this, all the planned division lines 14 along a predetermined direction are cut. Next, the chuck table 7 is rotated 90 degrees to align the unprocessed planned division line 14 in the direction perpendicular to the cutting groove formed by the above cutting process in the X-axis direction. Then, by performing the same cutting process as described above, cutting grooves are formed in all the planned division lines 14 of the wafer 10. By performing such processing, the wafer 10 is divided into individual device chips and the cutting process is completed. At this time, since the individual device chips remain supported by the sheet S through the solidified liquid resin P, the form of the wafer 10 is maintained as a whole. Each of the above operating parts of the dicing device 1 is controlled by control means (not shown).

[0019] After the above-described cutting process is performed and the wafer 10 is divided into individual device chips, the wafer 10 is moved from the processing area to the loading / unloading area, where it is sucked up by the transport means 11 and transported to the cleaning device 12 (details of which are not shown). The wafer 10, after being cleaned and dried by the cleaning device 12, is transported by the transport means 6 to the temporary storage table 5 and returned to the required position in the cassette 3 by the loading / unloading means 4. The cassette 3 can be raised and lowered as needed by the vertically movable table 3a to accommodate the wafer 10 in the desired position.

[0020] The dicing apparatus 1 of this embodiment has a configuration that is generally as described above, and the method for processing plate-shaped materials of this embodiment is carried out as follows.

[0021] When carrying out the plate-like material processing method of this embodiment, the sheet S is prepared as, for example, a first sheet S1 having a larger area than the wafer 10 as shown in Figures 2(a) to (d), or a second to fourth sheet S2 to S4 which is a modified version thereof. The first to fourth sheets S1 to S4 are preferably sheets made of thermoplastic resin, for example, sheets formed from polyester or polyethylene materials are used, and more specifically, for example, a polyethylene terephthalate (PET) sheet with a thickness of about 0.1 mm is selected.

[0022] The first sheet S1 shown in Figure 2(a) is a regular octagon, the second sheet S2 shown in Figure 2(b) is a square, the third sheet S3 shown in Figure 2(c) is a circular sheet, and the fourth sheet S4 shown in Figure 2(d) is a sheet with a shape that mimics the outer shape of the conventionally used frame F shown in Figure 7. The fourth sheet S4 also has notches S4b and S4c formed thereon, which mimic the notches Fb and Fc formed in the frame F in Figure 7. The first to third sheets S1 to S3 shown in Figures 2(a) to 2(c) do not have such notches formed thereon, but similar notches may be formed thereon as well. The sheets used in the present invention are not limited to the shapes of the first to fourth sheets S1 to S4 shown in Figures 2(a) to (d) above, but may be any shape as long as they have an area larger than the wafer 10 and are held by the chuck table 7. In the following description, the sheet S of this embodiment will be the first sheet S1 shown in Figure 2(a), and it will be described as supporting and processing the wafer 10 described based on Figure 7.

[0023] Once the wafer 10 and the first sheet S1 are prepared, in order to place the wafer 10 on the surface S1a of the first sheet S1, which will be the top surface during processing, a liquid resin supply means 20 is positioned above the center of the surface S1a of the first sheet S1, as shown in Figure 3, and a predetermined amount of liquid resin P is supplied by dripping from the liquid resin supply means 20. The liquid resin P is selected to be a liquid resin that solidifies over time, and can be selected from, for example, acrylic, rubber, silicone, or epoxy types. The liquid resin P supplied from the liquid resin supply means 20 is supplied in an amount that spreads over the entire surface S1a of the first sheet S1 and remains on the surface S1a, as shown in Figure 4.

[0024] Once the liquid resin P is supplied onto the surface S1a of the first sheet S1, before the liquid resin P solidifies, the wafer 10 is positioned with its surface 10a facing upwards and its back surface 10b facing downwards, as shown in the lower part of Figure 4, via the liquid resin P that has been dropped onto the surface S1a of the first sheet S1. After a predetermined time has elapsed, the liquid resin P solidifies, and the wafer 10 is supported only by the solidified liquid resin P and the first sheet S1 (plate-like object support process). Since the wafer 10 is supported only by the liquid resin P and the first sheet S1 to form an integrated object, the integrated object has a predetermined rigidity, and the rigidity of the integrated object is such that when supported at two points on the outer peripheral edge of the opposing first sheet S1, the first sheet S1 is maintained in a flat state. By the way, in the illustrated embodiment, the back surface 10b of the wafer 10 is placed on the surface S1a of the first sheet S1, but the present invention is not limited to this, and as shown in the upper right of Figure 4, the surface 10a of the wafer 10 may be placed facing the surface S1a of the first sheet S1, so that the surface 10a of the wafer 10 is placed on the surface S1a of the first sheet S1.

[0025] As described above, the plate-shaped material support process is carried out, and the multiple wafers 10, supported on the first sheet S1 via the solidified liquid resin P, are transported to the dicing apparatus 1 in a state where they are housed in the cassette 3 shown in Figure 1.

[0026] In carrying out the above cutting process as a processing step of the present invention, the wafer 10 loaded into the dicing apparatus 1 is loaded out of the cassette 3 by the loading / unloading means 4 and temporarily placed on the temporary storage table 5. Next, the wafer 10 is transported by the transport means 6 to the suction chuck 7a of the chuck table 7 located in the loading / unloading area shown in Figure 1, and is held by suction, and the outer edge of the first sheet S1 is fixed by the clamp 7b. The wafer 10 held on the chuck table 7 is moved by the X-axis moving means to be positioned directly below the alignment means 8, and the alignment means 8 detects a predetermined division line 14 as the area to be processed, aligns the division line 14 in the X-axis direction, and positions the wafer 10 directly below the cutting means 9, as shown in Figure 5.

[0027] The cutting means 9 includes a rotating shaft 9b arranged and held in the Y-axis direction in the figure, and an annular cutting blade 9a held at the tip of the rotating shaft 9b. The cutting blade 9a is moved by a Y-axis moving means (not shown) that indexes and feeds in the Y-axis direction as described above. The rotating shaft 9b is rotationally driven by a spindle motor (not shown).

[0028] Once the wafer 10 is positioned directly beneath the cutting means 9, the cutting blade 9a, rotated at high speed in the direction indicated by arrow R1, is positioned along the division line 14 aligned in the X-axis direction, and a cut is made from the surface 10a side. At the same time, the chuck table is fed in the X-axis direction to form a cutting groove 100 as shown in the figure. By performing the above cutting process, cutting grooves 100 are formed along all the division lines 14 formed on the wafer 10, as shown in the lower part of Figure 5. By performing this cutting process, the wafer 10 is divided into individual device chips 12' along the division lines 14.

[0029] As described above, even if the wafer 10 is divided into individual device chips 12' by the cutting process, the individual device chips 12' remain disposed and supported on the first sheet S1 via the liquid resin P, and therefore the overall shape of the wafer 10 is well maintained.

[0030] Once the cutting process has been performed as described above, the expansion process and pickup process described below are carried out to pick up the device chip 12' from the first sheet S1. The expansion process and pickup process can be carried out, for example, using the pickup device 40 shown in Figure 6. The pickup device 40 is equipped with an expansion means 42 that expands the first sheet S1 to expand the spacing between adjacent device chips 12'.

[0031] As shown in Figure 6(a), the expansion means 42 includes a cylindrical expansion drum 42a, a plurality of air cylinders 42b adjacent to the expansion drum 42a and extending upward at circumferential intervals, an annular retaining member 42c connected to the upper end of each air cylinder 42b, and a plurality of clamps 42d arranged at circumferential intervals on the outer peripheral edge of the retaining member 42c. Note that in Figure 6, for explanatory purposes, a part of the configuration is shown in cross-section. In this embodiment, the inner diameter of the expansion drum 42a is set to be greater than or equal to the diameter of the wafer 10, and the outer diameter of the expansion drum 42a is set to be smaller than the outer diameter of the first sheet S1. Furthermore, the retaining member 42c corresponds to the outer diameter dimension of the first sheet S1, and the outer peripheral region of the first sheet S1 is placed on the flat upper surface of the retaining member 42c.

[0032] As shown in Figure 6(a), the multiple air cylinders 42b raise and lower the retaining member 42c relative to the expansion drum 42a between a reference position where the upper surface of the retaining member 42c is at approximately the same height as the upper end of the expansion drum 42a (shown by the solid line) and an expanded position where the upper surface of the retaining member 42c is below the upper end of the expansion drum 42a (shown by the dashed-dot line). Note that in Figure 6(a), for illustrative purposes, the expansion drum 42a is shown to be moving up and down, but in reality, it is the retaining member 42c that moves up and down.

[0033] In addition to the expansion means 42 described above, the pickup device 40 is equipped with a pickup means 44, as shown in Figure 6(b). The pickup means 44 includes a pickup collet 44a for attracting the device chip 12' and a push-up means 44b disposed inside the expansion drum 42a to push the device chip 12' upward. This push-up means 44b is configured to be movable horizontally (in the direction indicated by arrow R4) within the expansion drum 42a and is equipped with a push rod 44c that moves up and down (in the direction indicated by arrow R5).

[0034] The pickup collet 44a shown in Figure 6(b) is configured to be movable in the horizontal and vertical directions. A suction means (not shown) is connected to the pickup collet 44a and is configured to be able to attract in the direction indicated by arrow R7, and the device chip 12' is attracted by the lower surface of the suction part 44d located at the tip of the pickup collet 44a.

[0035] Returning to Figure 6(a) and continuing the explanation, in the expansion process, first, with the wafer 10 divided into individual device chips 12' facing upwards, the first sheet S1 is placed on the upper surface of the holding member 42c located at the reference position. Next, the outer peripheral region of the first sheet S1 is fixed with a plurality of clamps 42d. Then, by lowering the holding member 42c in the direction of the expansion position indicated by arrow R2, a tensile force as indicated by arrow R3 is applied radially to the central region S1c of the first sheet S1. At this time, it is preferable to apply a heating means to the first sheet S1 to heat it. As described above, by using a thermoplastic resin as the first sheet S1, the first sheet S1 can be softened by heating it to a temperature close to the melting temperature of the material selected as the first sheet S1. As a result, as shown by the dashed line in Figure 6(a), the region supporting the wafer 10 on the first sheet S1 is expanded, and the spacing between the device chips 12' is widened effectively. Furthermore, in the above-described cutting process, if a sufficiently wide cutting groove 100 is formed along the planned division line 14, the expansion step can be omitted.

[0036] As described above, once the expansion process is performed, as shown in Figure 6(b), the suction portion 44d of the pickup collet 44a is positioned above the device chip 12' to be picked up, and the push-up means 44b is moved horizontally in the direction indicated by arrow R4 to be positioned below the device chip 12' to be picked up. Next, the push rod 44c of the push-up means 44b is extended in the direction indicated by arrow R5 to push up the target device chip 12' from below. In conjunction with this, the pickup collet 44a is lowered in the direction indicated by arrow R6, and the tip of the suction portion 44d of the pickup collet 72 adheres to the upper surface of the device chip 12'. Next, the pickup collet 44a is raised to detach the device chip 12' from the first sheet S1 and pick it up. Then, the picked-up device chip 12' is transported to a container such as a tray (not shown) for storage, or transported to a predetermined position for the next process. This pickup operation is then performed sequentially for all the device chips 12' (pickup process).

[0037] Once the expansion and pickup processes described above have been carried out, the first sheet S1 is disposed of in a designated waste container (disposal process). The first sheet S1 is extremely inexpensive compared to the conventionally used frame F (see Figure 7), and since it is composed only of the first sheet S1 and liquid resin P and has sufficient rigidity to hold the wafer 10, the frame F is no longer needed, eliminating the maintenance required for reuse and improving productivity.

[0038] It should be noted that the present invention is not limited to the embodiments described above. For example, in the above embodiment, the processing step for dividing the wafer 10 into a plurality of chips involved positioning the cutting blade 9a on the division line 14 of the wafer 10 and performing a cutting process to form a cutting groove 100 by cutting along the division line 14. However, instead of this, an ablation process may be performed in which a laser beam with a wavelength that is absorbed by the wafer 10 is irradiated onto the division line 14 of the wafer 10 to be divided, and a groove is formed along the division line 14 by ablation processing. Furthermore, instead of the above cutting process, a modified layer formation process may be performed in which a focal point of a laser beam with a wavelength that is transparent to a plate-like material is positioned inside the region of the wafer 10 to be divided and irradiated to form a modified layer. Thus, when processing steps such as forming grooves by ablation along the planned division line 14 or forming a modified layer by a modified layer formation process, the wafer 10 can be more reliably divided into device chips 12' by applying external force through the expansion process described above. [Explanation of symbols]

[0039] 1: Dicing device 1 2: Device housing 3: Cassette 3a: Table 4: Carrying in / out means 5: Temporary placement table 6: Conveying means 7: Chuck Table 7a: Suction chuck 7b: Clamp 8: Alignment Methods 9:Cutting means 9a: Cutting blade 9b: Rotation axis 10: Wafer 10a: surface 10b: Back side 12: Devices 12': Device chip 14: Planned division line 20: Liquid resin supply means 40: Pickup device 42: Expansion means 42a: Expansion Drum 42b: Air Cylinder 42c: Retaining member 42d: Clamp 44: Pickup method 44a: Pickup Collet 44b: Pushing mechanism 44c: Pushrod 44d: Adsorption part 100: Cutting groove F: Frame Fa: Opening Fb, Fc: Notches P: Liquid resin S: Seat S1: First seat S1a: Surface S1b: Back side S2: Second seat S3: Third Seat S4: Fourth Seat

Claims

1. A method for processing plate-shaped materials, A plate-like object support step involves placing the plate-like object on the upper surface of a sheet having a larger area than the plate-like object via a liquid resin, and supporting the plate-like object using only the solidified liquid resin and the sheet. A processing step for dividing the plate-like material into multiple chips, A pickup step of picking up the chip from the sheet, It is equipped with, The process includes clamping the outer circumference of the sheet and expanding the sheet to widen the gap between the chips, The sheet is a method for processing a plate-like object having a pair of parallel, straight edges that are opposite each other with respect to the center.

2. The method for processing a plate-shaped material according to Claim 1, further comprising a disposal step of discarding the sheet after the pickup step.

3. The method for processing a plate-shaped object according to claim 1 or 2, wherein the processing step is a cutting process in which a cutting blade is positioned in a region of the plate-shaped object to be divided and cutting is performed.

4. The method for processing a plate-like object according to claim 1 or 2, wherein the processing step is an ablation process in which a laser beam with a wavelength that is absorbable to the plate-like object is irradiated onto a region of the plate-like object to be divided, thereby forming grooves by ablation processing.

5. The method for processing a plate-like object according to claim 1 or 2, wherein the processing step is a modified layer formation step in which a focal point of a laser beam with a wavelength that is transparent to the plate-like object is positioned inside the region of the plate-like object to be divided and irradiated to form a modified layer.

6. The method for processing a plate-like object according to any one of claims 1 to 5, wherein the plate-like object is a wafer having a surface partitioned by lines on which a plurality of devices are to be divided, and the surface or back surface of the wafer is disposed on the upper surface of a sheet via a liquid resin.

7. A method for processing a plate-like material according to any one of claims 1 to 6, wherein the sheet is made of a polyester-based or polyethylene-based material.

8. The method for processing a plate-like material according to any one of claims 1 to 7, wherein the liquid resin is acrylic, rubber, silicone, or epoxy.

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