Frame unit processing method

Abstract

To provide a processing method of a frame unit that can push down a frame of the frame unit supported on a frame support part so that a wafer projects upward irrespective of a kind of a sheet.SOLUTION: A processing method of a frame unit according to the present invention that is the processing method of the frame unit in which a wafer is positioned in an opening of a frame having the opening accommodating the wafer provided at the middle to be integrally formed with the frame by a sheet comprises a trench forming step that forms a trench on the sheet being positioned between the wafer and the frame.SELECTED DRAWING: Figure 2

Description

【Technical Field】 【0001】 The present invention relates to a method for processing a frame unit in which a wafer is positioned in an opening of a frame having an opening for accommodating the wafer at the center and integrated with the frame by a sheet. 【Background Art】 【0002】 A wafer on which a plurality of devices such as ICs and LSIs are formed on the surface and 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】 The wafer is positioned in the opening of a frame having an opening for accommodating the wafer at the center so that the wafer can be transported to the next process while maintaining the form of the wafer even after being divided into individual device chips by a dicing device or the like, and is carried into the dicing device in the state of a frame unit integrated with the frame by a sheet (see, for example, Patent Documents 1 and 2). 【0004】 Further, the above frame unit is transported to holding means including a wafer table for supporting the wafer and a frame support portion disposed on the outer periphery of the wafer table for supporting the frame. The wafer is sucked and held by the wafer table, and when the frame is supported by the frame support portion, it is pushed down so that the position of the frame is lower than that of the wafer, and the wafer protrudes upward. 【Prior Art Documents】 【Patent Documents】[[ID=2六千]] 【0005】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2007-201178 【Patent Document 2】 Japanese Patent Application Laid-Open No. 2010-036275 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0006】 By the way, various types of sheets are used as the sheets that integrate the wafer and frame as described in Patent Documents 1 and 2 mentioned above, such as vinyl chloride sheets, polyethylene sheets, polypropylene sheets, and polystyrene sheets. Because each sheet has a different elongation rate, depending on the type of sheet selected, there is a problem that the sheet may not stretch properly when supported by the frame support part, and the frame may not be able to be properly pushed down. 【0007】 The present invention has been made in view of the above facts, and its main technical problem is to provide a method for processing a frame unit that can push down the frame of a frame unit supported by a frame support portion, regardless of the type of sheet, so that the wafer protrudes upward. [Means for solving the problem] 【0008】 To solve the main technical problems described above, the present invention provides a method for processing a frame unit which is integrated with a frame by a sheet, wherein a wafer is positioned in the opening for housing the wafer of the frame, and the frame is integrated with the sheet by the sheet, the method comprising a groove forming step of forming a groove in the sheet located between the wafer and the frame. The groove forming process is performed after positioning the wafer in the opening of the frame and forming the frame unit by attaching the surface of the sheet, whose outer periphery is attached to the frame, to the back surface of the wafer. The method for processing the frame unit is provided. 【0009】 After the groove forming step, a wafer ejection step may be performed in which a frame unit is placed on a holding means comprising a wafer table that supports the wafer and a frame support portion disposed on the outer circumference of the wafer table that supports the frame, the frame is supported by the frame support portion, and the wafer is ejected from the frame. Alternatively, after the wafer ejection step, a processing step may be performed on the ejected wafer. Furthermore, after the wafer ejection step, a transfer step may be performed in which another sheet is placed on the ejected wafer and the wafer is transferred to the other sheet. [Effects of the Invention] 【0010】 The present invention relates to a method for processing a frame unit, which is formed by positioning a wafer in the opening of a frame having an opening in the center for housing a wafer, and integrating the frame with a sheet, and includes a groove forming step of forming a groove in a sheet located between the wafer and the frame. Furthermore, the groove forming process is performed after positioning the wafer in the opening of the frame and forming the frame unit by attaching the surface of the sheet, whose outer periphery is attached to the frame, to the back surface of the wafer. As a result, the grooves formed in the sheet relieve tensile stress, making it possible to make the wafer protrude well from the frame, even when using a sheet with poor elongation. [Brief explanation of the drawing] 【0011】 [Figure 1] This is a perspective view showing an embodiment of the frame unit of this model. [Figure 2] (a) A perspective view showing an embodiment of the groove formation process, and (b) A perspective view of a frame unit with grooves formed in the sheet. [Figure 3] (a) A perspective view showing another embodiment of the groove shown in Figure 2, and (b) A perspective view showing yet another embodiment of the groove shown in Figure 2. [Figure 4] This is an overall perspective view of the cutting machine. [Figure 5] This is a perspective view showing how the frame unit is mounted on the holding means. [Figure 6] (a) A cross-sectional side view showing a part of the embodiment of Figure 5, and (b) A perspective view showing an embodiment of the protrusion process. [Figure 7] This is a side view showing a cross-sectional view of a part of the manufacturing process. [Figure 8] (a) A cross-sectional side view showing a portion of the frame unit in which the sheet to be transferred has been positioned after the protrusion process; (b) A cross-sectional side view showing a portion of the frame unit in which the sheet to be transferred has been attached to the wafer; (c) A cross-sectional side view showing a portion of the wafer after the transfer has been completed. [Modes for carrying out the invention] 【0012】 Hereinafter, embodiments relating to a method for processing a frame unit configured according to the present invention will be described in detail with reference to the attached drawings. 【0013】 The upper part of Figure 1 shows an embodiment of forming a frame unit U processed by the frame unit processing method of this embodiment. To form the frame unit U, first, a wafer 10, a frame F, and a sheet T are prepared as shown in the figure. The wafer 10 is a circular plate-shaped wafer made of, for example, silicon, on which a plurality of devices 12 are partitioned by division lines 14 and formed on the surface 10a. The frame F is an annular plate-shaped object made of, for example, stainless steel, with an opening Fa in the center for housing the wafer 10. The sheet T is, for example, a resin sheet having an adhesive layer on its surface, and its outer circumference is attached to the back surface of the frame F. Note that the sheet T is not limited to a resin sheet having an adhesive layer, and may be, for example, a thermocompression sheet that softens and exhibits adhesive force when heated. When forming the frame unit U, as shown in the figure, the wafer 10 is positioned in the opening Fa of the frame F, and the surface of the sheet T, whose outer circumference is attached to the frame F, is attached to the back surface 10b of the wafer 10. As a result, a frame unit U is formed in which the wafer 10 and the frame F are integrated by the sheet T, as shown in the lower part of Figure 1. 【0014】 Once the frame unit U is prepared as described above, the frame unit U is transported to the laser processing apparatus 20 (partially shown) shown in Figure 2 in order to perform a groove forming process in which grooves are formed in the area of ​​sheet Ta located between the wafer 10 and the frame F of the sheet T of the frame unit U. The frame unit U transported to the laser processing apparatus 20 is placed on a holding means (not shown). The holding means has a flat surface that supports the entire frame unit U as a holding surface, and a suction means having a plurality of suction holes is provided on the holding surface. The holding means includes an X-axis feeding means that feeds the holding means and the laser beam irradiation means 22 relatively in the X-axis direction, a Y-axis feeding means that feeds the holding means and the laser beam irradiation means 22 relatively in the Y-axis direction which is perpendicular to the X-axis direction, and a rotational driving means that rotates the holding means (all of which are not shown). 【0015】 The frame unit U, transported to the laser processing apparatus 20, is placed on the holding means and then held by suction to the holding surface of the holding means by activating a suction means (not shown). The frame unit U held by suction to the holding means is imaged using an imaging means (not shown) provided in the laser processing apparatus 20, and alignment is performed. This alignment detects the region and shape of the sheet Ta located between the wafer 10 and the opening Fa of the frame F in the frame unit U. 【0016】 If the shape of the sheet Ta positioned between the wafer 10 and the opening Fa of the frame F is detected by the above alignment, the X-axis feed means and the Y-axis feed means described above are operated to position the laser beam irradiation means 22 above a predetermined processing start position in the region of the sheet Ta. Next, a condensing point of the laser beam LB having a wavelength absorbable by the sheet Ta is positioned on the surface of the sheet Ta and irradiated, and the frame unit U is fed in the X-axis direction for processing along a predetermined processing line to perform ablation processing on the region of the sheet Ta, thereby forming a predetermined groove 100 as shown in the figure. The groove 100 is a groove that does not penetrate to the back side of the sheet Ta and is formed to a depth such that it will not break even when the wafer protruding step described later is performed to expand the sheet Ta. 【0017】 If the above groove 100 is formed on a predetermined processing line, the frame unit U is fed by indexing in the Y-axis direction by a predetermined interval determined in advance by the Y-axis feed means, and the laser beam LB is irradiated onto the sheet Ta in the same manner as described above along a predetermined processing line adjacent in the Y-axis direction. The frame unit U is fed in the X-axis direction for processing to form the groove 100. Similarly, the frame unit U is fed in the X-axis direction for processing and indexed in the Y-axis direction to form a plurality of grooves 100 in the region of the sheet Ta. If a plurality of grooves 100 are formed in parallel over the entire area of the sheet Ta, the frame unit U is rotated by 90 degrees to align the direction orthogonal to the direction in which the grooves 100 have already been formed with the X-axis direction. Then, the condensing point of the laser beam LB is positioned and irradiated onto the region of the sheet Ta in the same manner as described above, and a plurality of grooves 100 are formed at the above predetermined interval in a direction orthogonal to the previously formed grooves 100. Thus, the groove forming step of the present embodiment is completed. By this groove forming step, as shown in Fig. 2(b), a plurality of grooves 100 are formed in a lattice pattern in the region of the sheet Ta of the frame unit U. Thus, by forming the grooves 100 in a lattice pattern in the sheet Ta, even if the sheet T is made of a material with a low elongation rate, the tensile force when expanding the region of the sheet Ta is relaxed, and the sheet Ta can be appropriately stretched. 【0018】 In the groove forming step in the above-described embodiment, a plurality of grooves 100 are formed in a lattice pattern. However, the form of the grooves formed by the groove forming step of the present invention is not limited to this. For example, as shown in FIG. 3(a), annular grooves 110 may be formed in multiple layers in the entire region of the sheet Ta located between the wafer 10 and the frame F. When forming the grooves 110, the above-described laser beam irradiation means 22 is positioned at a predetermined radial position from the center position of the frame unit U within the region of the sheet Ta, the condensing point position is positioned on the surface of the sheet Ta, and the laser beam LB is irradiated. At the same time, the frame unit U is rotated in the direction indicated by the arrow R1 to form an annular groove 110. If the groove 110 is formed, the laser beam LB is irradiated while changing the distance from the center position of the frame unit U to the irradiation position at a predetermined interval to form a plurality of such grooves 110, which can be multiple annular grooves 110 as shown in FIG. 3(a). 【0019】 Furthermore, the form of the grooves formed by the groove forming step of the present invention may be the form shown in FIG. 3(b). In the form shown in FIG. 3(b), a plurality of grooves 120 are formed in the radial direction within the region of the sheet Ta with the center of the frame unit U as the base end. Also when forming the grooves 120, it is possible to form them by operating the laser beam irradiation means 22, the X-axis feeding means, the Y-axis feeding means, etc. of the above-described laser processing apparatus 20, and the detailed description thereof is omitted. Note that the form of the grooves formed by the groove forming step of the present invention is not limited to the above-described form, and may be a combination of the above-described grooves 100 to 120. 【0020】 In the above-described groove forming step, it has been described that the holding means of the laser processing apparatus 20 holds the side of the frame unit U to which the wafer 10 is adhered upward and the sheet T side downward, and forms the above-described grooves 100 to 120 in the sheet Ta located between the wafer 10 and the frame F. However, the present invention is not limited to this, and it may be held with the sheet T side upward and the side to which the wafer 10 is adhered downward, and grooves may be formed in the region of the sheet Ta in the above-described sheet T. 【0021】 Furthermore, in the above-described embodiment, grooves 100 to 120 were formed using the laser beam irradiation means 22 of the laser processing apparatus 20. However, the present invention is not limited thereto, and grooves may be formed using a cutting apparatus (not shown) with a cutting blade having an annular cutting edge. When forming grooves in the sheet Ta region of the frame unit U with the cutting blade, it is preferable to invert the frame unit U shown in the lower part of Figure 1 so that the sheet T side faces upward and hold it in the holding means of the cutting apparatus. The cutting blade of the cutting apparatus may form grooves in the sheet Ta region located between the wafer 10 and the frame F in the form of grooves 100 to 120 as described above. 【0022】 Once grooves have been formed in the sheet Ta located between the wafer 10 and the frame F in the frame unit U through the groove formation process described above, the wafer protrusion process described below can be carried out. 【0023】 In this embodiment, the wafer protrusion process is a process performed to cut the wafer 10 using the cutting device 30 shown in Figure 4. The cutting device 30 includes a housing 31 with a substantially rectangular parallelepiped shape, a cassette 32 placed on a cassette table 32a of the housing 31, an loading / unloading means 34 for loading a frame unit U from the cassette 32 to a temporary storage table 33, a transport means 35 having a swivel arm for transporting the frame unit U loaded onto the temporary storage table 33 to a holding means 36 equipped with a wafer table 36a, a cutting means 38 rotatably equipped with a cutting blade 38a for performing cutting on a wafer 10 held on the wafer table 36a, an alignment means 37 for imaging the wafer 10 held on the wafer table 36a and detecting the area to be cut by the cutting means 38, and a cleaning / unloading means 39a for transporting the frame unit U including the wafer 10 from the loading / unloading position where the wafer table 36a is positioned in Figure 4 to a cleaning device 39 (details omitted). The wafer table 36a has a holding surface on its upper surface for holding the wafer 10, and the dimensions of the holding surface correspond to the diameter of the wafer 10. The holding surface is formed of a breathable material and is connected to a suction means (not shown). By operating the suction means, a suction negative pressure is generated on the holding surface, allowing the wafer 10 to be held in place by suction. Furthermore, the cutting device 30 is equipped with control means and display means (not shown). 【0024】 As shown in Figure 5, multiple frame support portions 36b (four in this embodiment) are arranged at equal intervals around the outer circumference of the wafer table 36a of the cutting apparatus 30 to support the frame F when the frame unit U is placed on and held on the wafer table 36a. A rotatable gripping plate 36c for gripping the frame F is provided on each frame support portion 36b. 【0025】 When performing the wafer ejection process, as shown in Figure 5, the gripping plate 36c of the frame support portion 36b is opened, and the frame unit U is placed on the wafer table 36a. Next, the gripping plate 36c of the frame support portion 36b is rotated in the direction indicated by arrow R2 in Figure 6(a). As a result, as shown in Figure 6(a), the rotating gripping plate 36c engages with the frame F, and as shown in Figure 6(b), the frame F descends in the direction indicated by arrow R3, and the frame F is supported by the frame support portion 36b. When viewed from the side, the wafer 10 protrudes upward from the frame F, and the ejection process is completed. 【0026】 In this embodiment, since the frame unit U has been subjected to a groove-forming process in advance, appropriate grooves (for example, any one or a combination of grooves 100 to 120) are formed in the region of the sheet Ta located between the wafer 10 and the frame F. Therefore, when the frame F is pushed down by the gripping plate 36c of the frame support portion 36b during the ejection process, the grooves formed in the sheet Ta relieve the tensile stress during the ejection process. This allows the wafer 10 to be properly ejected from the frame F, even if the sheet Ta is made of a material with low elongation. 【0027】 As described above, once the protrusion process is performed on the wafer table 36a of the cutting device 30, a processing process is performed on the protruding wafer 10. In this embodiment, alignment is performed using the imaging means 37, and the position of the division line 14 formed on the surface 10a of the wafer 10 is detected by the alignment. Next, based on the position information of the division line 14 detected by the imaging means 37, a moving means (not shown) is activated to move the wafer table 36a and the cutting means 38 relative to each other in the X-axis, Y-axis, and Z-axis directions, so that the cutting blade 38a of the cutting means 38 is rotated at high speed in the direction indicated by arrow R4, as shown in Figure 7, and the wafer table 36a is processed by cutting from the surface 10a of the wafer 10 in the X-axis and Y-axis directions, so that cutting grooves are formed along all the division lines 14 of the wafer 10 and the processing process is completed. In this embodiment, the frame F is supported by the frame support portion 36b, and the protrusion process is performed relative to the frame unit U. As a result, the wafer 10 protrudes upward from the frame F, and the frame F does not get in the way when cutting is performed by the cutting blade 38a. 【0028】 In the embodiments described above, the protrusion process and processing process of the present invention were carried out by the cutting device 30 described above, but the present invention is not limited thereto. The protrusion process and processing process of the present invention can be carried out by other processing devices equipped with holding means similar to the holding means 36 described above, for example, a laser processing device not shown. In that case as well, the protrusion process can be carried out by the holding means, and the processing process can be carried out by laser beam irradiation means not shown, which is provided in the laser processing device, to perform laser processing on the wafer 10. 【0029】 Furthermore, in the above-described embodiment, after performing the protrusion process described with reference to Figure 6, a processing step was performed on the protruding wafer 10. However, the present invention is not limited thereto, and a transfer step may be performed in which another transfer sheet T' is attached to the wafer 10 protruding by the above-described protrusion process, and the wafer 10 is transferred to the sheet T'. 【0030】 When carrying out the transfer process, for example, a frame F' having an opening in the center capable of accommodating a wafer 10, and a transfer sheet T' having an adhesive layer attached to the back surface of the frame F' so as to close the opening of the frame F' are prepared, and the side of the sheet T' with the adhesive layer formed thereon (the bottom side in the figure) is placed facing the surface 10a of the wafer 10 protruding from the frame F (see Figure 8(a)). For the sake of explanation, only the cross-sections of the frame F' and sheet T' are shown in Figure 8(a), but the frame F' and sheet T' of this embodiment have the same form as the frame F and sheet T shown in the middle section of Figure 1. 【0031】 Once the sheet T' and frame F' described above are prepared, as shown in Figure 8(b), the sheet T' is lowered in the direction indicated by arrow R5 and attached to the surface 10a of the wafer 10. Next, as shown in Figure 8(c), the wafer 10 is raised together with the sheet T' in the direction indicated by arrow R6 to peel the back surface 10b of the wafer 10 from the sheet T of the frame unit U and transfer it to the sheet T'. This completes the transfer process of the present invention. In order to carry out this transfer process well, it is preferable to perform an adhesion reduction process to reduce the adhesive strength of the sheet T to the wafer 10 before carrying out the above-described ejection process. As a method for carrying out the adhesion reduction process, for example, it is preferable to irradiate the back surface of the sheet T with ultraviolet light or cool the sheet T before holding the frame unit U on the wafer table 36a in order to carry out the above-described ejection process. Furthermore, if the adhesive strength reduction process is not performed, it is preferable to set the adhesive strength of the adhesive layer applied to sheet T' to be stronger than that of the adhesive layer of sheet T attached to the back surface 10b of wafer 10. As described above, since the groove forming process and the protrusion process are performed on the frame unit U according to this embodiment, the transfer process can be carried out appropriately without the sheet T being peeled off touching the sheet T' being transferred. [Explanation of Symbols] 【0032】 10: Wafer 12: Devices 14: Planned division line 20: Laser processing equipment 22: Laser beam irradiation means 30: Cutting equipment 31: Housing 32: Cassette 33: Temporary Table 34: Carrying in / out means 35: Conveying means 36: Holding means 36a: Wafer Table 36b: Frame support section 36c: Gripping plate 37: Imaging means 38:Cutting means 38a: Cutting blade 39: Washing device 39a: Washing and conveying means 100, 110, 120: groove F, F': Frame T, T': Sheet

Claims

[Claim 1] A method for processing a frame unit which is integrated with a sheet by positioning a wafer in the opening of a frame having an opening in the center for housing a wafer, The process includes a groove forming step in which grooves are formed in a sheet located between the wafer and the frame, The groove forming step is a method for processing a frame unit, which is performed after positioning a wafer in an opening in the frame and attaching the surface of a sheet, whose outer periphery is attached to the frame, to the back surface of the wafer to form a frame unit. [Claim 2] A method for processing a frame unit according to claim 1, wherein, after the groove forming step, the frame unit is placed on a holding means comprising a wafer table for supporting a wafer and a frame support portion disposed on the outer circumference of the wafer table for supporting a frame, the frame is supported by the frame support portion, and a wafer ejection step is performed to make the wafer protrude from the frame. [Claim 3] The method for processing a frame unit according to claim 2, further comprising a processing step of processing the protruding wafer after the wafer protrusion step. [Claim 4] The method for processing a frame unit according to claim 2, further comprising a transfer step of arranging another sheet on the ejected wafer after the wafer ejection step, and transferring the wafer to the other sheet.

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