Expansion device, expansion method

Abstract

An expansion device and an expansion method are provided to efficiently perform the shrinkage of an expansion sheet. The expansion device expands the expansion sheet of a workpiece unit, which includes a workpiece, an expansion sheet adhered to the workpiece, and an annular frame to which the outer peripheral side of the expansion sheet is adhered. The expansion device has an expansion unit capable of expanding the expansion sheet and a sheet shrinkage unit that heats the expansion sheet to cause it to shrink. The sheet shrinkage unit includes a hot air outlet, an air supply path, a heating unit that heats the inside of the air supply path, and a valve that controls the supply and blockage of air from an air supply source. The sheet shrinkage unit opens the valve to supply the air to the air supply path and can eject the heated air from the hot air outlet. The sheet shrinkage unit can stop ejecting the heated air from the hot air outlet without stopping the heating unit by closing the valve.

Description

Technical Field

[0001] The present invention relates to an expanding device and an expanding method for expanding an expanding sheet peripherally adhered to a ring-shaped frame. Background Art

[0002] After setting a plurality of mutually intersecting division lines (also referred to as scribe lines) on the front surface of a disk-shaped wafer and forming devices in each region divided by the division lines, when the wafer is divided along the division lines, individual device chips can be formed. The formed device chips are mounted on an electronic device or the like and used.

[0003] The division of the wafer is carried out, for example, using a laser processing device. For example, a laser beam having a wavelength that is transmissive to the wafer is converged along the division line to the inside of the wafer, thereby forming a modified layer as a division starting point along the division line.

[0004] A sheet called an expanding sheet is pre-adhered to the back side of the wafer. A ring-shaped frame formed of metal or the like is adhered to the outer peripheral side of the expanding sheet. And when the wafer is adhered to the expanding sheet, a workpiece unit in which the wafer, the expanding sheet, and the ring-shaped frame are integrated is formed.

[0005] When the expanding sheet is expanded radially outward in a state where a modified layer is formed inside the wafer along the division line, the wafer is broken starting from the modified layer to form device chips, and further the intervals between the device chips are expanded. When the intervals between the device chips are expanded, when the workpiece unit is carried or the like later, the device chips are not likely to come into contact with each other, thereby suppressing damage to the device chips.

[0006] However, when the expansion of the expanding sheet is released, slack is generated in the expanding sheet, and thus a process called thermal shrinkage is performed: the expanding sheet with slack is heated to cause it to thermally shrink (for example, refer to Patent Document 1 and Patent Document 2). When the expanding sheet is shrunk, the slack of the expanding sheet is reduced, thereby maintaining the intervals between the device chips.

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-206136

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2011-100920

[0009] Conventionally, the expanding sheets of a plurality of workpiece units are expanded one by one, and when the expanded expanding sheets are shrunk, the operation and stop of the heating unit are repeated each time the expanding sheet is heated. In this case, the temperature of the heating unit drops during the period from when the expanding sheet of a certain workpiece unit is shrunk until the expanding sheet of the next workpiece unit is to be shrunk.

[0010] When the temperature of the heating unit does not reach the specified temperature, it is impossible to appropriately shrink the extended sheet to a specified degree. Therefore, when shrinking the extended sheet, it is necessary to operate the heating unit and wait until the temperature of the heating unit reaches the specified temperature. In the case of expanding the extended sheet one by one, the problem of reduced processing efficiency due to the waiting time until the shrinking of the extended sheet is implemented is significant, and improvement is desired. Summary of the Invention

[0011] The present invention has been completed in view of this problem, and an object thereof is to provide an expanding device and an expanding method capable of efficiently shrinking an extended sheet.

[0012] According to one aspect of the present invention, there is provided an expanding device that expands an extended sheet of a workpiece unit. The workpiece unit includes a workpiece, the extended sheet adhered to the workpiece, and a ring-shaped frame to which the outer peripheral side of the extended sheet is adhered. The expanding device is characterized in that it has: a frame holding unit capable of holding the ring-shaped frame of the workpiece unit; an expanding unit capable of expanding the extended sheet included in the workpiece unit having the ring-shaped frame held by the frame holding unit; and a sheet shrinking unit that heats a region between the outer periphery of the workpiece and the inner peripheral edge of the ring-shaped frame of the extended sheet included in the workpiece unit having the ring-shaped frame held by the frame holding unit to shrink the region of the extended sheet, thereby reducing the slack of the extended sheet that has become slack due to expansion by the expanding unit. The sheet shrinking unit includes: a hot air outlet facing the extended sheet; an air supply path having one end communicating with the hot air outlet and the other end connected to an air supply source; a heating unit that heats the inside of the air supply path, thereby heating the air supplied from the air supply source; a valve that controls the supply and blocking of air from the air supply source; and a switch that switches between heating and stopping heating of the heating unit. The sheet shrinking unit opens the valve to supply the air from the air supply source to the air supply path, and heats the air in the air supply path using the heating unit, thereby being able to eject the heated air from the hot air outlet. The sheet shrinking unit closes the valve to block the supply of air from the air supply source to the air supply path, thereby being able to stop ejecting the heated air from the hot air outlet without stopping the heating unit.

[0013] According to another aspect of the present invention, there is provided an expanding method for expanding the expanding sheets of a plurality of work-piece units one by one. Each of the plurality of work-piece units includes a work-piece, the expanding sheet adhered to the work-piece, and an annular frame to which the outer peripheral side of the expanding sheet is adhered. The expanding method is characterized by the following steps: an expanding step of holding the annular frame and expanding the expanding sheet; and a sheet shrinking step of, after the expanding step is performed, jetting heated air, which has been heated by a heating unit, into a region of the expanding sheet located between the outer periphery of the work-piece and the inner peripheral edge of the annular frame to shrink the region of the expanding sheet, thereby reducing the slack of the expanding sheet generated in the expanding step. During the performance of the expanding step and the sheet shrinking step on the plurality of work-piece units one by one, the operation of the heating unit is not stopped. The sheet shrinking step starts by starting the jetting of the air and ends by stopping the jetting of the air.

[0014] In the expanding device and the expanding method according to one aspect of the present invention, air is heated by a heating unit, and the heated air is jetted to heat the expanding sheet. Also, the jetting of the air is stopped without stopping the heating unit during the period when the shrinking of the expanding sheet is not performed. Therefore, the temperature of the heating unit does not decrease even during the period when the expanding sheet is not heated.

[0015] In this case, when heating the expanding sheet, there is no need to wait until the temperature of the heating unit reaches a specified temperature. In the expanding device and the expanding method according to one aspect of the present invention, the expansion and contraction of the expanding sheet of the work-piece unit can be performed in a short time, so the processing efficiency can be improved.

[0016] Therefore, according to the present invention, there are provided an expanding device and an expanding method capable of efficiently performing the shrinking of the expanding sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is a perspective view schematically showing an example of the expanding device.

[0018] Figure 2 FIG. is a cross-sectional view schematically showing the expanding device into which the work-piece unit is carried.

[0019] Figure 3 FIG. is a cross-sectional view schematically showing the expanding device in a state where the expanding sheet is fixed.

[0020] Figure 4 FIG. is a cross-sectional view schematically showing the expanding device performing the expansion of the expanding sheet.

[0021] Figure 5 FIG. is a cross-sectional view schematically showing the expanding device performing the heating of the expanding sheet having slack.

[0022] Description of Reference Numerals

[0023] 1: Workpiece; 3: Modified layer; 5: Device; 7: Expanding sheet; 7a: DAF (Die Attach Film); 9: Frame; 11: Workpiece unit; 13: Partition groove; 15: Device chip; 2: Expanding device; 4: Frame holding unit; 6: Frame supporting part; 6a, 8a: Opening; 8: Frame pressing part; 10, 26: Cylinder; 12, 28: Rod; 14: Expanding unit; 16: Holding table; 18: Suction path; 20: Suction port; 22, 42: On-off valve; 24: Suction source; 30: Sheet shrinking unit; 32: Rod; 32a, 34a: Air supply pipe; 34: Support plate; 36: Heating unit; 38: Air supply path; 38a: Hot air outlet; 40: Air supply source; 44: Coil heater; 46: Switch; 48: Rotating motor; 50: Rotating shaft; 52: Shutter; 52a: Opening. Detailed Embodiment

[0024] Referring to the accompanying drawings, embodiments of the present invention will be described. In the expanding device and expanding method of the present embodiment, the expanding sheet of the workpiece unit in which the workpiece, the expanding sheet, and the annular frame are integrated is expanded. In Figure 2 etc., a cross-section of the workpiece unit 11 is shown.

[0025] The expanding sheet 7 included in the workpiece unit 11 includes, for example, a base material layer made of vinyl chloride, polyolefin, or the like, and a paste layer supported by the base material layer. The central region of one surface of the expanding sheet 7 is adhered to the workpiece 1. In addition, the outer peripheral portion of the expanding sheet 7 is adhered to the inner peripheral portion of the annular frame 9 having an opening.

[0026] The workpiece 1 is, for example, a wafer made of a material such as silicon, SiC (silicon carbide), or other semiconductors, or a substantially circular plate-shaped substrate made of a material such as sapphire, glass, or quartz. The front surface of the workpiece 1 is divided into a plurality of regions by a plurality of mutually intersecting dividing predetermined lines (scribe lines), and devices 5 such as ICs (Integrated Circuits) are formed in each of the divided regions. When the workpiece 1 is divided along the dividing predetermined line, individual device chips can be formed.

[0027] A modified layer 3 serving as a starting point for division is formed inside the workpiece 1 along the dividing predetermined line. For example, the modified layer 3 can be formed by converging a laser beam having a wavelength that is transmissive to the workpiece 1 (a wavelength that can pass through the workpiece 1) along the dividing predetermined line into the inside of the workpiece 1.

[0028] When a force directed radially outward is applied to the workpiece 1 having the modified layer 3 formed therein along the division predetermined line, cracks are generated from the modified layer 3 to the upper and lower surfaces of the workpiece 1, and the workpiece 1 is divided to form respective device chips 15 (see Figure 4 etc.). Then, in order to easily pick up the respective device chips 15 from the expansion sheet 7, the expansion sheet 7 is further expanded, thereby expanding the intervals between the device chips 15.

[0029] In addition, a DAF (die attach film) may be provided in advance on the workpiece 1. The DAF is a film that functions as an adhesive when mounting the device chip 15 on a predetermined mounting object. This expansion device can divide the workpiece 1 provided with the DAF together with the DAF. In this case, the device chip 15 provided with the DAF is formed.

[0030] Use Figures 1 to 5 The expansion device of the present embodiment will be described. In Figure 1 a perspective view of the expansion device 2 is schematically shown, and in Figure 2 a cross-sectional view of the expansion device 2 into which the workpiece unit 11 is carried is schematically shown.

[0031] The expansion device 2 includes: a frame holding unit 4 that fixes the annular frame 9 of the workpiece unit 11; and an expansion unit 14 that can expand the expansion sheet 7 of the workpiece unit 11. In addition, the expansion device 2 has a sheet shrinking unit 30 that heats and shrinks the expanded expansion sheet 7 that has become slack, thereby reducing the slack. Hereinafter, each component of the expansion device 2 will be described in detail.

[0032] The frame holding unit 4 has a frame support portion 6 that can support the annular frame 9 of the workpiece unit 11. The frame support portion 6 is an annular member with a flat upper surface and has an opening 6a in the center with a diameter corresponding to the diameter of the opening of the annular frame 9. The upper ends of a plurality of rods 12 are connected to the lower surface of the frame support portion 6, and the lower ends of the rods 12 are respectively housed in a lifting mechanism such as a cylinder 10. By operating the cylinder 10 to raise and lower the rod 12, the frame support portion 6 can be raised and lowered.

[0033] The frame holding unit 4 also has an annular frame pressing portion 8 that can clamp the annular frame 9 together with the frame support portion 6. The frame pressing portion 8 is an annular member that has an opening 8a with the same diameter as the opening 6a of the frame support portion 6 in the center and has a flat lower surface.

[0034] When the frame support portion 6 on which the annular frame 9 is placed is raised so that the annular frame 9 contacts the lower surface of the frame pressing portion 8, the annular frame 9 is clamped and held by the frame support portion 6 and the frame pressing portion 8. The frame pressing portion 8 can hold the annular frame 9 with a firm force so that the fixed annular frame 9 does not shift in position.

[0035] In addition, a cooling mechanism capable of supplying cold air to the workpiece unit 11 held by the frame holding unit 4 can be provided on the frame pressing portion 8. When the extension piece 7 is cooled in advance by this cooling mechanism when the extension piece 7 is being extended, the extension piece 7 can be hardened.

[0036] When the extension piece 7 is extended without being hardened, the extension piece 7 only extends in the region between the outer periphery of the workpiece 1 and the inner peripheral edge of the annular frame 9, and it is not easy to appropriately apply a force directed radially outward to the workpiece 1. Therefore, when the extension piece 7 is cooled and hardened by this cooling mechanism, the extension piece 7 becomes less likely to extend, and the extension piece 7 is extended by the extension unit 14 described below to appropriately apply this force to the workpiece 1, so that the workpiece 1 can be divided.

[0037] The extension unit 14 can extend the extension piece 7 included in the workpiece unit 11 having the annular frame 9 held by the frame holding unit 4. The extension unit 14 has a holding table 16 housed in the opening 6a of the frame support portion 6 of the frame holding unit 4. The workpiece 1 is placed on the upper surface of the holding table 16 with the extension piece 7 interposed therebetween in the workpiece unit 11 having the annular frame 9 fixed by the frame holding unit 4.

[0038] The holding table 16 can attract and hold the workpiece 1 with the extension piece 7 interposed therebetween. A plurality of suction ports 20 are formed on the upper surface of the holding table 16, and a suction path 18 connected to each suction port 20 is formed inside the holding table 16. And the suction path 18 is connected to a suction source 24 disposed outside the holding table 16.

[0039] An on-off valve (valve) 22 is provided between the suction path 18 and the suction source 24. When the on-off valve 22 is opened, the negative pressure generated by the suction source 24 can act on the workpiece held on the upper surface of the holding table 16 via the suction path 18 and the suction ports 20. That is, the suction path 18, the suction ports 20, the on-off valve 22, the suction source 24, etc. function as a holding mechanism for attracting and holding the workpiece 1 with the extension piece 7 interposed therebetween.

[0040] The upper ends of a plurality of rods 28 are connected to the lower surface of the holding table 16, and the lower ends of the rods 28 are respectively received in lifting mechanisms such as cylinders 26. By operating the cylinders 26 to lift and lower the rods 28, the holding table 16 can be lifted and lowered. When the holding table 16 is raised while the annular frame 9 is fixed to the frame holding unit 4, the extension pieces 7 pasted on the annular frame 9 are extended radially outward.

[0041] The sheet contraction unit 30 heats and contracts the area between the inner peripheral edge of the annular frame 9 of the extension sheet 7 that has been extended and become slack and the outer peripheral edge of the workpiece 1, thereby reducing the slack of the extension sheet 7. The sheet contraction unit 30 includes: a rod 32 that supports each component of the sheet contraction unit 30 from above; a disc-shaped support plate 34 that is connected to the lower end of the rod 32; and a plurality of heating units 36 that are provided on the lower surface of the outer periphery of the support plate 34.

[0042] The heating unit 36 has a function of heating air and discharging the heated air downward. A cross-section of the heating unit 36 is shown in Figure 2 The heating unit 36 has an air supply path 38, and the air supply path 38 has a cylindrical housing along the vertical direction.

[0043] An air supply source 40 is connected to the upper end of the air supply path 38 through an air supply pipe 34a provided inside the support plate 34 and an air supply pipe 32a provided inside the rod 32. An on-off valve (valve) 42 is provided between the air supply path 38 and the air supply source 40. When the on-off valve 42 is opened, air can be supplied from the air supply source 40 to the air supply path 38.

[0044] A coiled heater 44 is provided inside the air supply path 38 as a heat source for heating the air supplied from the air supply source 40. And, a hot air outlet 38a is provided on the lower surface of the air supply path 38. The coiled heater 44 is connected to a power source and a switch 46. When the switch 46 is turned on and current flows through the coiled heater 44, heat is generated from the coiled heater 44 to heat the air supplied from the air supply source 40.

[0045] When the on-off valve 42 is opened in a state where the coiled heater 44 is generating heat, the air (hot air) heated by the coiled heater 44 is discharged downward from the hot air outlet 38a. In addition, in the expansion device 2 of the present embodiment, the switch 46 is always turned on. And, the start and stop of the heated air supplied from the heating unit 36 to the extension sheet 7 are controlled by controlling the opening and closing of the on-off valve 42.

[0046] For example, when starting the operation of the expanding device 2, the switch 46 is turned on, and when ending the operation of the expanding device 2 after expanding the expanding sheets 7 of the plurality of work units 11, the switch 46 is turned off. Therefore, air heated to a temperature above a specified temperature is stably ejected from the hot air ejection port 38a.

[0047] The sheet shrinking unit 30 has a rotary motor 48 on the central lower surface of the support plate 34, and the upper end of a rotary shaft 50 along the vertical direction is mounted on the rotary motor 48. A disc-shaped shielding plate 52 is connected to the lower end of the rotary shaft 50. The diameter of the disc-shaped shielding plate 52 is slightly smaller than the diameter of the opening 8a of the frame pressing portion 8 of the frame holding unit 4. The frame pressing portion 8 can move up and down relative to the shielding plate 52 in a state where the shielding plate 52 is housed in the opening 8a.

[0048] The shielding plate 52 has a plurality of openings 52a in a configuration corresponding to the arrangement of the plurality of heating units 36 in the support plate 34 (see Figure 1 and Figure 5 ). For example, the support plate 34 has heating units 36 at a plurality of fixed positions arranged at equal intervals in the radial direction at a radial length from the center of the lower surface of the support plate 34 being a specified radial length. And the shielding plate 52 has openings 52a in a number equal to the number of the heating units 36 at positions arranged at equal intervals in the radial direction at a radial length from the center of the shielding plate 52 being the specified radial length.

[0049] The shielding plate 52 has a function of preventing heat from the heating unit 36 from being unnecessarily transferred to the work unit 11. When it is desired to block the heat transfer from the heating unit 36 to the work unit 11, the rotary motor 48 is operated to rotate the rotary shaft 50, so that the shielding plate 52 rotates to shift the positions of the respective heating units 36 and the positions of the respective openings 52a.

[0050] In addition, when the expanding sheet 7 of the work unit 11 that has become slack is shrunk by the sheet shrinking unit 30, the shielding plate 52 is rotated to align the positions of the respective openings 52a with the positions of the respective heating units 36. And the heated air is supplied to the expanding sheet 7 through the hot air ejection port 38a of the air supply path 38 of the heating unit 36 and the opening 52a of the shielding plate 52.

[0051] In addition, the form of the shielding plate 52 is not limited to this. For example, the shielding plate 52 may have an opening and closing mechanism capable of opening and closing each of the openings 52a. In this case, the sheet shrinking unit 30 does not need to have the rotary motor 48 for rotating the shielding plate 52. In addition, each heating unit 36 may respectively have a shielding plate below the hot air ejection port 38a of the air supply path 38, and the shielding plate has an opening and closing mechanism.

[0052] A rotary motor (not shown) is connected to the upper end of the rod 32 of the sheet shrinking unit 30. When the rotary motor is operated while heated air is supplied to the extended sheet 7 through the heating unit 36, the area between the workpiece 1 of the extended sheet 7 that has been extended and become slack and the inner peripheral edge of the annular frame 9 is heated along the entire circumference. Also, the extended sheet 7 shrinks and the slack is reduced.

[0053] When the on-off valve 42 is closed after the shrinking of the extended sheet 7 is completed to stop the supply of air from the air supply source 40 to the air supply passage 38, the supply of heated air to the extended sheet 7 can be stopped. At this time, there is no need to close the switch 46 to stop the current flowing through the coil heater 44.

[0054] Further, the rotary motor 48 is operated to rotate the rotary shaft 50, thereby rotating the shutter 52 to displace the positions of the respective heating units 36 and the positions of the respective openings 52a. In this case, since the shutter 52 enters the state between the air supply passage 38 and the extended sheet 7, the heat transfer to the extended sheet 7 is more reliably blocked.

[0055] The sheet shrinking unit 30 opens the on-off valve 42 (valve) to supply air from the air supply source 40 to the air supply passage 38, and heats the air in the air supply passage 38 using the heating unit 36, so that the heated air can be ejected from the hot air ejection port 38a. Further, the sheet shrinking unit 30 closes the valve to block the supply of air from the air supply source 40 to the air supply passage 38, so that the ejection of the heated air from the hot air ejection port 38a can be stopped without stopping the coil heater 44 of the heating unit 36.

[0056] Conventionally, the extended sheets 7 of the plurality of workpiece units 11 are extended one by one, and when the extended extended sheets 7 are shrunk, the operation and stop of the heating unit 36 are repeated each time the extended sheet 7 is heated. In this case, the temperature of the heating unit 36 drops during the period from when the shrinking of the extended sheet 7 of a certain workpiece unit 11 is completed until the shrinking of the extended sheet 7 of the next workpiece unit 11 is to be performed.

[0057] When the temperature of the heating unit 36 does not reach the specified temperature, the shrinking of the extended sheet 7 cannot be uniformly performed to the specified degree. Therefore, when the shrinking of the extended sheet 7 is performed, it is necessary to wait until the temperature of the heating unit 36 reaches the specified temperature after the heating unit 36 is operated.

[0058] In contrast, in the expansion device 2 of the present embodiment, after the expansion sheet 7 is contracted, the heating of the expansion sheet 7 can be stopped even when the switch 46 of the coiled heater 44 is turned on. Moreover, during the period when a new workpiece unit 11 is carried into the expansion device 2, the expansion sheet 7 is expanded and then contracted, the coiled heater 44 continuously generates heat at a prescribed output. And by opening the on-off valve 42, heated air can be supplied to the expansion sheet 7.

[0059] Therefore, during the period when the contraction of the expansion sheet 7 is not carried out, the temperature of the coiled heater 44 does not drop either. Thus, there is no need to wait for the temperature of the coiled heater 44 to rise to a prescribed temperature to start the contraction of the expansion sheet 7. Accordingly, according to the expansion device 2 of the present embodiment, the expansion and contraction of the expansion sheet 7 of the workpiece unit 11 can be carried out in a short time, so the processing efficiency can be improved.

[0060] However, in the expansion device 2 of the present embodiment, there may also be a time when the switch 46 of the coiled heater 44 is turned off during the period when the contraction of the expansion sheet 7 is not carried out. In this case, considering the time required from when the switch 46 is turned on until the coiled heater 44 rises to a prescribed temperature, before carrying out the contraction of the expansion sheet 7, ensure this time and switch the switch 46 to on.

[0061] Next, the expansion method of the present embodiment will be described. This expansion method is implemented, for example, in the expansion device 2. Hereinafter, the expansion method of the present embodiment will be described by taking the case of being implemented by the expansion device 2 as an example. In this expansion method, the expansion sheets 7 of a plurality of workpiece units 11 each including a workpiece 1, an expansion sheet 7 adhered to the workpiece 1, and an annular frame 9 adhered to the outer peripheral side of the expansion sheet 7 are expanded one by one.

[0062] First, in the expansion method of the present embodiment, a carrying-in step of carrying the workpiece unit 11 into the expansion device 2 can be carried out. In Figure 2 FIG. shows schematically the workpiece unit 11 carried into the expansion device 2 and the expansion device 2. In addition, in Figure 2 and Figure 2 in the following figures, cross-sectional views of some constituent elements of the expansion device 2 and the like are shown.

[0063] When carrying in the workpiece unit 11, as Figure 2 shown, the annular frame 9 of the workpiece unit 11 is placed on the frame support portion 6 of the frame holding unit 4, and the workpiece 1 is placed on the holding table 16 with the expansion sheet 7 interposed therebetween.

[0064] Next, an expansion step is performed in which the annular frame 9 of the workpiece unit 11 is held and the expansion sheet 7 is expanded. Figure 3 It is a cross-sectional view schematically showing the expansion step. When expanding the expansion sheet 7, first, the cylinder 10 is actuated to raise the rod 12, thereby raising the frame support portion 6 until the annular frame 9 abuts against the upper frame pressing portion 8. In this case, the annular frame 9 of the workpiece unit 11 is held by clamping with the frame support portion 6 and the frame pressing portion 8.

[0065] Next, the expansion sheet 7 is expanded radially outward. In Figure 4 a cross-sectional view of the expansion device 2 for expanding the expansion sheet 7 and the expanded expansion sheet 7 is shown. When expanding the expansion sheet 7 radially outward, the cylinder 26 of the expansion unit 14 is actuated to raise the rod 28, thereby raising the holding table 16.

[0066] In this case, when the expansion sheet 7 is expanded, a force acting radially outward is applied to the workpiece 1, and cracks are generated in the vertical direction starting from the modified layer 3, and the workpiece 1 is divided with the modified layer 3 as the starting point. When the workpiece 1 is divided, individual device chips 15 each having a device 5 are formed. The device chips 15 continue to be held on the expansion sheet 7.

[0067] In addition, the expansion device 2 may have a cooling mechanism for cooling the workpiece unit 11 with cold air. When expanding the expansion sheet 7, the workpiece unit 11 can be cooled inside the expansion device 2 in advance by this cooling mechanism. When the expansion sheet 7 is cooled, the expansion sheet 7 becomes hard, and when the expansion sheet 7 is expanded radially outward, it is easy to appropriately apply the force caused by the expansion to the workpiece 1. And after expanding the expansion sheet 7, the cooling of the expansion sheet 7 etc. is stopped.

[0068] In addition, a cooling mechanism may be provided on the holding table 16 of the expansion device 2. In the case where DAF is provided on the workpiece 1, etc., the cooling mechanism mounted on the holding table 16 can be actuated as needed to cool the workpiece 1 through the expansion sheet 7. When the workpiece 1 is cooled, the expansion of the DAF can be suppressed, so it is easy to divide the DAF together with the workpiece 1.

[0069] Then, when releasing the expansion of the expansion sheet 7, the cylinder 26 is actuated to lower the rod 28, thereby lowering the holding table 16. Here, before the expansion of the expansion sheet 7 is released after the expansion of the expansion sheet 7, the on-off valve 22 is opened in advance. And the negative pressure generated by the suction source 24 acts on the expansion sheet 7 and the workpiece 1 of the workpiece unit 11 through the suction path 18 and the suction port 20, thereby holding the expansion sheet 7 etc. on the holding table 16.

[0070] When the expansion of the expansion sheet 7 is released, slack is generated in the expansion sheet 7. At this time, the region of the expansion sheet 7 that overlaps the workpiece 1 is fixed by the holding mechanism of the holding table 16. Therefore, as Figure 5 shown, the slack concentrates in the region between the outer periphery of the workpiece 1 of the expansion sheet 7 and the inner peripheral edge of the annular frame 9.

[0071] Therefore, in order to reduce this slack, a sheet shrinkage step of heating the expansion sheet 7 to cause it to shrink is then performed. The process of causing the expansion sheet 7 to shrink by heating is also called heat shrinkage. In Figure 5 FIG. shows a cross-sectional view of the expansion device 2 that releases the expansion of the expansion sheet 7 and performs heating and the expansion sheet 7.

[0072] In the sheet shrinkage step, the rotation motor 48 is operated to rotate the shutter 52, and the opening 52a is moved below the heating unit 36. And, the on-off valve 42 (valve) is opened, and air is supplied from the air supply source 40 to the air supply passage 38. In addition, the switch 46 is pre-opened, and the coiled heater 44 is pre-heated to a predetermined temperature. The switch 46 is opened, for example, simultaneously with the start of the expansion device 2.

[0073] When this air is supplied to the air supply passage 38, the air is heated by the coiled heater 44. And, the air heated inside the air supply passage 38 is jetted through the hot air jet outlet 38a of the air supply passage 38 and the opening 52a of the shutter to the region of the expansion sheet 7 where slack has occurred. Then, when the rod 32 is rotated, the region of the expansion sheet 7 is heated along the entire region, and the slack is removed.

[0074] In addition, during the operation of the expansion device 2, the switch 46 is always open, and the jetting and stopping of the heated air are switched by controlling the opening and closing of the on-off valve 42. The sheet shrinkage step starts by starting the jetting of this air and ends by stopping the jetting of this air.

[0075] It takes a certain amount of time until the coiled heater 44 reaches the predetermined temperature after the switch 46 is opened, but when the switch 46 is always open, there is no need to wait for the temperature of the coiled heater 44 to rise. Therefore, by controlling the opening and closing of the on-off valve 42 without switching the opening and closing of the switch 46, the start and stop of the sheet shrinkage step can be controlled.

[0076] When the heated air is jetted to the region of the expansion sheet 7 for heating, the region of the expansion sheet 7 shrinks, so that the slack of the expansion sheet 7 generated in the expansion step can be reduced. In this case, when the operation of the holding mechanism of the holding table 16 is stopped and the suction of the expansion sheet 7 is released, in the region overlapping the workpiece 1, the expansion sheet 7 maintains the expanded state.

[0077] When reducing the slack of the extension sheet 7, ensure that the spacing between the device chips 15 is relatively wide. Therefore, when the workpiece unit 11 is transported or the like later, adjacent device chips 15 are not likely to come into contact with each other, suppressing damage to the device chips 15. After performing the sheet shrinkage step, the workpiece unit 11 is carried out of the extension device 2, and each device chip 15 is picked up from the extension sheet 7.

[0078] A new workpiece unit 11 is carried into the extension device 2 from the outside. And in this extension device 2, the extension step and the sheet shrinkage step are performed on this workpiece unit 11. Thus, in the extension method of the present embodiment, the extension step and the sheet shrinkage step are performed on each of the plurality of workpiece units 11 one by one.

[0079] Here, during the extension step and the slack removal step being performed on each of the plurality of workpiece units 11 one by one, the operation of the heating unit 36 is not stopped. The sheet shrinkage step starts by opening the on-off valve 42 (valve) to start the injection of the air, and ends by closing the on-off valve 42 (valve) to stop the injection of the air.

[0080] Therefore, during the period when the shrinkage of the extension sheet 7 is not performed, the temperature of the coiled heater 44 does not decrease either. Thus, there is no need to wait for the temperature of the coiled heater 44 to rise to a specified temperature and the sheet shrinkage step of the extension sheet 7 can be started. Thereby, according to the extension method of the present embodiment, the extension and shrinkage of the extension sheet 7 of the workpiece unit 11 can be performed in a short time, so that the processing efficiency can be improved.

[0081] In addition, the present invention is not limited to the description of the above embodiment, and various modifications can be made and implemented. For example, in the above embodiment, the following situation is described: when the extension sheet 7 is extended, the holding table 16 is raised while the annular frame 9 is clamped by the frame support portion 6 and the frame pressing portion 8. However, one mode of the present invention is not limited to this.

[0082] For example, the extension device 2 may have the following extension mechanism: this extension mechanism extends the extension sheet 7 by depressing the inner region of the annular frame 9 of the extension sheet 7 pasted in a manner to seal the opening of the annular frame 9 from above. In this case, the orientation of the workpiece unit 11 is adjusted so that the surface of the extension sheet 7 to which the workpiece 1 is pasted faces downward, and the workpiece unit 11 is carried into the extension device 2.

[0083] The structure, method, etc. of the above embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the purpose of the present invention.

Claims

1. An expansion device for expanding an expansion sheet of a workpiece unit, wherein the workpiece unit comprises a workpiece, the expansion sheet adhered to the workpiece, and an annular frame to which the outer peripheral side of the expansion sheet is adhered, characterized in that: The expansion unit has: A frame holding unit capable of holding the annular frame of the workpiece unit; an expansion unit capable of expanding the expansion piece included in the workpiece unit having the annular frame held by the frame holding unit; as well as a sheet shrinking unit that heats a region of the expansion sheet included in the workpiece unit having the annular frame held by the frame holding unit and located between the outer periphery of the workpiece and the inner periphery of the annular frame to shrink the region of the expansion sheet, thereby reducing the slack of the expansion sheet that has been expanded by the expansion unit, The sheet shrinking unit contains: a hot air ejection port facing the expansion sheet; An air supply path, one end of which is connected to the hot air ejection port and the other end of which is connected to an air supply source; a heating unit that heats the interior of the air supply path, thereby heating the air supplied from the air supply source; a valve that controls supply and blocking of air from the air supply source; A switch for switching the heating unit on and off; a shield having openings in a configuration corresponding to the configuration of the heating unit; as well as a rotating motor which aligns the position of the opening with the position of the heating unit and misaligns the position of the heating unit with the position of the opening by rotating the shutter; The sheet contraction unit aligns the position of the opening with the position of the heating unit by the rotary motor, and opens the valve to supply the air from the air supply source to the air supply path, and the air is heated by the heating unit in the air supply path, thereby being able to eject the heated air from the hot air ejection port through the opening toward the area of the expansion sheet. The sheet contraction unit closes the valve to block the supply of air from the air supply source to the air supply path, thereby stopping the ejection of the heated air from the hot air outlet without stopping the heating unit, and the position of the heating unit is offset from the position of the opening by the rotating motor, thereby shielding the transfer of heat from the heating unit to the expansion sheet.

2. The expansion device according to claim 1, characterized in that: The frame holding unit has: a frame support portion capable of supporting the annular frame of the workpiece unit; and a frame pressing portion, which can clamp the annular frame together with the frame supporting portion, The frame pressing portion is provided with a cooling mechanism capable of supplying cool air to the workpiece unit held by the frame holding unit.

3. An expansion method, wherein expansion sheets of a plurality of workpiece units are expanded one by one, wherein the plurality of workpiece units respectively include a workpiece, the expansion sheet attached to the workpiece, and an annular frame to which the outer peripheral side of the expansion sheet is attached, characterized in that: This extension method has the following steps: An expansion step of holding the annular frame and expanding the expansion sheet; and A sheet contraction step of, after performing the expansion step, jetting air heated by a heating unit onto a region of the expansion sheet located between the outer periphery of the workpiece and the inner peripheral edge of the annular frame to contract the region of the expansion sheet, thereby reducing the slack of the expansion sheet generated in the expansion step. During the expansion step and the sheet contraction step being performed on each of a plurality of workpiece units one by one, the operation of the heating unit is not stopped. The sheet contraction step starts by starting the jetting of the air and ends by stopping the jetting of the air. In the sheet contraction step, the position of the opening of a shutter having an opening is aligned with the position of the heating unit, and the air heated by the heating unit is jetted through the opening onto the region of the expansion sheet located between the outer periphery of the workpiece and the inner peripheral edge of the annular frame. In the expansion step, the position of the opening of the shutter is offset from the position of the heating unit to shield the heat transfer from the heating unit to the expansion sheet.

4. The expansion method according to claim 3, wherein in the expansion step, the expansion sheet is pre-cooled before the expansion sheet is expanded.

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