Sheet attaching apparatus, sheet peeling method, and sheet attaching method

Abstract

To provide a sheet attaching apparatus, a sheet peeling method, and a sheet attaching method that can improve workability and work efficiency, and reduce labor.SOLUTION: A sheet attaching apparatus 1 comprises: a wafer holding table 40; a first housing 31; a first suction part; an air introduction part that introduces air into the first housing 31; a sheet holding table 50; a second housing 32; a second suction part; a sheet peeling mechanism that peels a sheet S from a wafer W; a detection unit (camera) 60 that detects bubbles between the sheet S and the wafer W or wrinkles of the sheet S; a sheet carrying-out mechanism that carries out the sheet S peeled from the wafer W by the sheet peeling mechanism, from the sheet holding table 50; and a control unit 70 that, when the detection unit 60 detects bubbles between the sheet S and the wafer W or wrinkles of the sheet S, controls the drive of the sheet peeling mechanism and the sheet carrying-out mechanism to peel the sheet S from the wafer W and carry out the peeled sheet S from the sheet holding table 50.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sheet adhering device for adhering a sheet to the surface of a wafer to protect devices formed on the surface of the wafer, a sheet peeling method for peeling the sheet from the wafer, and a sheet adhering method for adhering the sheet to the surface of the wafer. [Background technology]

[0002] In recent years, there has been a demand for smaller and thinner electronic devices such as personal computers and smartphones, and the semiconductor devices used in these electronic devices are also becoming smaller and thinner. Specifically, in the semiconductor device manufacturing process, the surface of a disk-shaped semiconductor wafer (hereinafter simply referred to as a "wafer") is divided into multiple rectangular regions by streets (planned division lines) arranged in a grid pattern, and devices such as ICs and LSIs are formed in each rectangular region. Then, the wafer on which multiple devices have been formed is cut along the streets by a cutting device to form multiple semiconductor chips.

[0003] Furthermore, in order to reduce the size and thickness of individual semiconductor chips, the back surface of the wafer (the surface opposite to the surface on which the devices are formed) is usually ground to a predetermined thickness using a grinding machine before cutting the wafer along the streets. Here, when grinding the back surface of the wafer, a sheet (protective tape) is attached to the front surface of the wafer to protect the devices formed on the front surface of the wafer.

[0004] However, the sheet attached to the surface of the wafer is peeled off from the surface of the wafer after grinding is completed, and at this time, part of the adhesive layer of the sheet remains on the surface of the device, causing problems such as contaminating the bumps and bonding pads of the device and leading to disconnections.

[0005] Therefore, a method has been proposed in which a thermoplastic sheet without an adhesive layer is heated in a reduced pressure chamber and the sheet is pressed onto the surface of a wafer using the differential pressure within the reduced pressure chamber (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-121940 [Patent Document 2] Japanese Patent Publication No. 2022-122206 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when thermocompression bonding a thermoplastic sheet to the surface of a wafer, problems arise, such as air being trapped between the sheet and the wafer, leaving bubbles between them, or wrinkles forming in the sheet, preventing the sheet from being uniformly bonded to the entire surface of the wafer. When such problems occur, workers have to peel the sheet off the wafer and reattach it to the wafer. This manual work results in poor workability and efficiency, and places a heavy physical burden on the worker.

[0008] The present invention has been made in consideration of the above problems, and its purpose is to provide a sheet adhering device, a sheet peeling method, and a sheet adhering method that can automatically peel the sheet from the wafer and re-adhere the sheet to the wafer when air bubbles are detected between the sheet and the wafer or wrinkles in the sheet are detected, thereby improving workability and efficiency and reducing labor. [Means for solving the problem]

[0009] The invention of claim 1 is a sheet adhering device for adhering a sheet to a wafer, comprising: a wafer holding table for holding the wafer; a first housing having a recess for accommodating the wafer holding table; a first suction unit for sucking air from within the first housing; an air introduction unit for introducing air into the first housing; a sheet holding table for holding the sheet; a second housing having a recess for accommodating the sheet holding table and combined with the first housing with the sheet interposed therebetween; a second suction unit for sucking air from within the second housing; and a sheet peeler for peeling the sheet from the wafer. The sheet peeling device is characterized by comprising a peeling mechanism, a detection unit that detects air bubbles between the sheet attached to the wafer and the wafer or wrinkles in the sheet, a sheet discharge mechanism that discharges the sheet peeled from the wafer by the sheet peeling mechanism from the sheet holding table, and a control unit that, when the detection unit detects air bubbles between the sheet and the wafer or wrinkles in the sheet, drives and controls the sheet peeling mechanism and the sheet discharge mechanism to peel the sheet from the wafer and discharge the peeled sheet from the sheet holding table.

[0010] The invention described in claim 2 is characterized in that, in the invention described in claim 1, when the first housing and the second housing are combined with the sheet interposed, the control unit uses the second suction unit to suck air from inside the second housing to make the internal pressure of the second housing negative, and introduces air into the first housing using the air introduction unit to maintain the internal pressure of the first housing at atmospheric pressure.

[0011] The invention described in claim 3 is a sheet peeling method for peeling off a sheet that is larger than the wafer and that is attached to the wafer, and is characterized by comprising a wafer holding process for holding the wafer on a wafer holding table contained in a recess of a first housing, a combining process for combining a second housing having a recess with the first housing by sandwiching the sheet therebetween, and a peeling process for peeling off the sheet from the wafer by making the internal pressure of the first housing a positive pressure higher than the internal pressure of the second housing.

[0012] The invention described in claim 4 is a sheet adhering method for adhering a sheet to a wafer, comprising: a wafer holding step of holding a wafer on a wafer holding table housed in a recess of a first housing; a sheet holding step of holding a sheet on a sheet holding table housed in a recess of a second housing; a combining step of combining the first housing and the second housing by sandwiching the sheet; a sheet adhering step of making the internal pressure of the first housing a negative pressure lower than the internal pressure of the second housing and adhering the sheet to the wafer; an inspection step of inspecting whether or not there are any air bubbles or wrinkles in the sheet; and if there are any air bubbles or wrinkles in the sheet during the inspection step, terminating the process; and if there are any air bubbles or wrinkles in the sheet, peeling the sheet from the wafer using the sheet peeling method described in claim 3, and then holding a new sheet on the sheet holding table and adhering the new sheet to the wafer. [Effects of the Invention]

[0013] According to the invention described in claim 1, the detection unit captures an image of the sheet attached to the wafer, and the control unit determines based on the captured image whether air bubbles are detected between the sheet and the wafer, or whether wrinkles are detected on the sheet. If at least one of air bubbles or wrinkles is detected, the sheet is peeled off from the wafer by the sheet peeling mechanism, and the peeled sheet is transported out by the sheet discharge mechanism. A new sheet is then transported to the sheet attachment device, and the entire series of operations from attaching the sheet to detecting air bubbles and wrinkles is performed automatically without human intervention, thereby improving workability and efficiency and reducing labor.

[0014] According to the invention of claim 2, in the peeling process of peeling a sheet in which air bubbles or wrinkles have been detected from a wafer, the first housing and the second housing are joined together with the sheet interposed, and air is sucked into the second housing to make the internal pressure of the second space negative, and air (atmosphere) is introduced into the first housing by the first air inlet to maintain the internal pressure of the first housing at atmospheric pressure. As a result, a force acts on the sheet to peel it from the wafer due to the internal pressure difference (differential pressure) between the first housing and the second housing. Therefore, this force can be used to easily peel the sheet from the wafer.

[0015] According to the invention of claim 3, in the combining step, the first housing and the second housing are combined with the sheet sandwiched therebetween, and the internal pressure of the first housing is set to a positive pressure higher than the internal pressure of the second housing, so that a force acts on the sheet to peel it off from the wafer due to the difference (differential pressure) between the internal pressures of the first housing and the second housing, making it possible to easily peel the sheet off from the wafer.

[0016] According to the invention described in claim 4, if there are air bubbles or wrinkles in the sheet, the sheet is peeled off from the wafer using the sheet peeling method described in claim 3, and then a new sheet is attached to the wafer in a re-attachment process.This means that the entire process from attaching the sheet to detecting air bubbles and wrinkles can be performed automatically without manual intervention, thereby improving workability and efficiency and reducing labor. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. [Figure 2] 1 is a side cross-sectional view showing the overall configuration of a sheet sticking device according to the present invention. [Figure 3] 4 is a flowchart showing a sheet sticking procedure in the sheet sticking device according to the present invention. [Figure 4] 4 is a side cross-sectional view showing a sheet holding step in the sheet sticking device according to the present invention. FIG. [Figure 5]4 is a side cross-sectional view showing a wafer holding step in the sheet sticking device according to the present invention. FIG. [Figure 6] 5 is a side cross-sectional view showing a vacuum chamber forming step in the sheet sticking device according to the present invention. FIG. [Figure 7] 5 is a side cross-sectional view showing a heating process in the sheet sticking device according to the present invention. FIG. [Figure 8] 4 is a side cross-sectional view showing a sticking process in the sheet sticking device according to the present invention. FIG. [Figure 9] 5 is a side cross-sectional view showing a detection process in the sheet sticking device according to the present invention. FIG. [Figure 10] 5 is a side cross-sectional view showing a peeling process in the sheet sticking device according to the present invention. FIG. [Figure 11] 5 is a side cross-sectional view showing a peeling process in the sheet sticking device according to the present invention. FIG. [Figure 12] 5 is a side cross-sectional view showing a sheet carrying-out process in the sheet sticking device according to the present invention. FIG. [Figure 13] FIG. 10 is a side cross-sectional view showing the overall configuration of a sheet sticking device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] The sheet adhering apparatus 1 according to the present invention is an apparatus for adhering a sheet S (see FIG. 2) to the surface of a wafer W shown in FIG. 1. The wafer W is, for example, a thin, disk-shaped member made of single-crystal silicon (Si), and its surface (the top surface in FIG. 1) is partitioned into a plurality of rectangular regions by mutually orthogonal streets (planned division lines) L1, L2 arranged in a grid pattern, and a device D such as an IC or LSI is formed in each rectangular region. Note that the wafer W may be made of silicon (Si), silicon carbide (SiC), glass, ceramics, sapphire, or the like.

[0020] [Configuration of sheet attachment device] Here, the configuration of the sheet sticking device 1 according to the present invention will be described below with reference to FIG.

[0021] The sheet bonding device 1 shown in FIG. 2 includes a sheet conveying mechanism 10, a wafer conveying mechanism 20, and a vacuum chamber 30. The sheet conveying mechanism 10 suction-holds and conveys a thin, disk-shaped sheet S on a horizontally disposed, disk-shaped sheet holding plate 11, which can be moved horizontally by a drive mechanism 12. In this embodiment, the sheet S is made of a thermoplastic resin, or a thermoplastic resin substrate with an adhesive layer disposed on one side. Examples of thermoplastic resins that can be used here include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polystyrene (PS).

[0022] In addition, the wafer transport mechanism 20 transports the wafer W horizontally by suction holding it on the underside of a horizontally arranged wafer holding plate 21 using a plurality of suction pads 22, and the wafer holding plate 21 can be moved horizontally by a drive mechanism 23.

[0023] The vacuum chamber 30 is a cylindrical container made up of a first housing 31 and a second housing 32 that are integrally connected to each other, and the lower first housing 31 is formed in a cylindrical (dish-shaped) shape with a bottom that is open at the top, and a cylindrical wafer holding table 40 that holds a wafer W is housed in a recessed portion inside the first housing 31. The upper surface of the wafer holding table 40 forms a holding surface that holds the wafer W, and a sheet-like heater H is built into the upper part of the wafer holding table 40 near the holding surface inside the wafer holding table 40. Here, a power source E is connected to the heater H via an electric cord 41, and the electric cord 41 is provided with a switch SW for turning on and off the power supply E to the heater H.

[0024] Furthermore, a vent hole 31a is opened in the bottom wall 31A of the first housing 31, and a pipe 2 is connected to this vent hole 31a. The pipe 2 is connected to a suction source 3 via an on-off valve V1, and the pipe 2, suction source 3, and on-off valve V1 together form a first suction section that sucks air inside the first housing 31. A branch pipe 4 branches off from the pipe 2, and this branch pipe 4 can be selectively opened to the atmosphere by an on-off valve V2, and the pipe 2, branch pipe 4, and on-off valve V2 together form a first air introduction section that introduces air into the first housing 31.

[0025] On the other hand, the upper second housing 32 is formed in a cylindrical shape (inverted dish shape) with a bottom that opens downward, and a disk-shaped sheet holding table 50 that holds the sheet S is housed in a recessed portion inside the second housing 32. A disk-shaped porous member 50A is incorporated in the center of the lower part of the sheet holding table 50. Here, a cylindrical support shaft 33 penetrates from above through the center of the upper wall 32A of the second housing 32 via a ring-shaped seal member 34, and the sheet holding table 50 is attached horizontally to the lower end of the support shaft 33 that faces the recessed portion of the second housing 32.

[0026] A suction source 6 is connected to the porous member 50A of the sheet holding table 50 via a communication passage 33a formed in the center of the sheet holding table 50 and the support shaft 33 and a pipe 5 connected to the communication passage 33a, and an on-off valve V3 is attached to the pipe 5. A branch pipe 7 branches off from the pipe 5 and is connected to an air supply source 8 via an on-off valve V4. A camera 60 constituting a detection unit is built into the center of the porous member 50A, and the camera 60 is electrically connected to a control unit 70.

[0027] Here, the second housing 32 and the sheet holding table 50 can be raised and lowered together with the support shaft 33 by an elevation mechanism 80, and a piping 9 is connected to an air vent 32a opening in the upper wall 32A, and this piping 9 is connected to a suction source 13 via an on-off valve V5. A branch pipe 14 branching off from the piping 9 can be opened to the atmosphere via an on-off valve V6. The piping 9, on-off valve V5, and suction source 13 form a second suction section that sucks air from inside the second housing 32, and the piping 9, branch pipe 14, and on-off valve V6 form a second air introduction section that introduces air into the second housing 32.

[0028] A ring-shaped suction groove 32b is formed in the bottom surface (the surface joining with the first housing 31) of the cylindrical side wall 32B of the second housing 32, and a communication passage 32c formed in the side wall 32B of the second housing 32 opens into this suction groove 32b. The suction source 13 is connected to the communication passage 32c by a pipe 15, and the pipe 15 is provided with an on-off valve V7.

[0029] [Operation of the sheet attachment device] Next, the operation of the sheet adhering device 1 configured as described above, that is, the method of adhering the sheet S to the surface of the wafer W using the sheet adhering device 1 and the sheet peeling method of first adhering the sheet to the wafer and then peeling it off from the wafer, will be explained based on Figures 3 to 12.

[0030] The sheet S is attached to the surface of the wafer W as shown in FIG. 1) Sheet holding process (step S1) 2) Wafer holding process (step S2) 3) Vacuum chamber formation process (step S3) 4) Heating step (step S4) 5) Adhesion process (step S5) 6) Detection process (step S6) Here, in the detection step (step S6), if an air bubble is detected between the sheet S and the wafer W or if a wrinkle in the sheet S is detected (step S7: Yes), 7) Peeling step (step S8) 8) Sheet carrying-out process (step S9) 9) Sheet holding process (step S10) After further performing the above, the vacuum chamber forming step (step S3), the heating step (step S4), the adhering step (step S5), and the detection step (step S6) are repeated until no air bubbles between the sheet S and the wafer W or wrinkles in the sheet S are detected (step S7: No). Each step will be explained below.

[0031] 1) Sheet holding process (step S1): 4, the sheet holding process is a process in which the sheet S held by the sheet conveying mechanism 10 is transported to the vacuum chamber 30 and held on the sheet holding table 50 housed in the second housing 32 of the vacuum chamber 30. Here, the sheet S used has an area larger than that of the wafer W. In this sheet holding process, the second housing 32 and the sheet holding table 50 are raised by the lifting mechanism 80, and a gap is formed between the second housing 32 and the first housing 31. At this time, the on-off valves V1 and V5 are closed and the on-off valves V2 and V5 are open, so that the insides of the first housing 31 and the second housing 32 of the vacuum chamber 30 are both open to the atmosphere, and the internal pressure therein is maintained at atmospheric pressure.

[0032] In the above state, the sheet S, which is suction-held on the sheet holding plate 11 of the sheet conveying mechanism 10, is suction-held on the holding surface of the lower surface of the sheet holding table 50, which is arranged between the first housing 31 and the second housing 32 of the vacuum chamber 30. That is, when the on-off valve V3 is opened with the on-off valve V4 closed, the porous member 50A of the sheet holding table 50 is evacuated by the suction source 6, generating a negative pressure in the porous member 50A. The sheet S is attracted by this negative pressure and held by suction on the holding surface (lower surface) of the porous member 50A. At the same time, the on-off valve V7 is opened, and the suction groove 32b formed in the lower surface (the joint surface with the first housing 31) of the side wall 32B of the second housing 32 is evacuated by the suction source 13, generating a negative pressure in the suction groove 32b. The outer periphery of the sheet S is attracted by this negative pressure and held by suction on the lower surface of the side wall 32B of the second housing 32. During this sheet holding process, the switch SW of the heater H is in the OFF state, and the power supply E to the heater H is cut off, so that the heater H is in a non-heat generating state.

[0033] In the sheet holding process, as described above, when the sheet S is suction-held between the sheet holding table 50 and the underside of the side wall 32B of the second housing 52, the sheet conveying mechanism 10 moves horizontally to remove the sheet holding plate 11 from the gap between the first housing 31 and the second housing 32, and the next wafer holding process is carried out.

[0034] 2) Wafer holding process (step S2): 5, the wafer holding process is a process in which the wafer W held by the wafer transfer mechanism 20 is transported to the vacuum chamber 30 and held on the wafer holding table 40 housed in the first housing 31 of the vacuum chamber 30. In this wafer holding process as well, a gap is formed between the first housing 31 and the second housing 32, and the interiors of the first housing 31 and the second housing 32 are both open to the atmosphere and the internal pressure is maintained at atmospheric pressure.

[0035] In the above state, the wafer W held by the plurality of suction pads 22 of the wafer holding plate 21 of the wafer transport mechanism 20 is disposed between the first housing 31 and the second housing 32 of the vacuum chamber 30, and is held on the holding surface on the upper surface of the wafer holding table 40 in the first housing 31. Note that even during this wafer holding process, the switch SW of the heater H is in the OFF state, and power supply from the power source E to the heater H is cut off, so the heater H is in a non-heat generating state.

[0036] In the wafer holding process, once the wafer W is held on the holding surface of the wafer holding table 40 as described above, the wafer transport mechanism 20 moves horizontally to remove the wafer holding plate 21 from the gap between the first housing 31 and the second housing 32, and the next vacuum chamber forming process is carried out.

[0037] 3) Vacuum chamber formation process (step S3): The vacuum chamber forming process is a process of forming vacuum chambers inside the first housing 31 and the second housing 32 of the vacuum chamber 30. In this vacuum chamber forming process, as shown in FIG. 6, the second housing 32 is lowered by the lifting mechanism 80, and the second housing 32 is connected to the first housing 31 via the sheet S, thereby integrating the two (combining process). In this state, a first space R1 and a second space R2 partitioned by the sheet S are formed inside the first housing 31 and the second housing 32 of the vacuum chamber 30, respectively. Note that at this time, both the on-off valves V3 and V7 are open, and the suction grooves 32b formed in the lower surfaces of the porous member 50A of the sheet holding table 50 and the side wall 32B of the second housing 32 are evacuated by the suction sources 6 and 13, respectively. Therefore, the sheet S is suction-held on the lower surface (holding surface) of the porous member 50A of the sheet holding table 50, and the outer periphery of the sheet S is suction-held on the lower surface of the side wall 32B of the second housing 32.

[0038] In the above state, when the on-off valve V1 of the first suction unit is opened with the on-off valve V2 closed, air is sucked out from the first space R1 in the first housing 31, creating a vacuum within the first space R1. Similarly, when the on-off valve V5 of the second suction unit is opened with the on-off valve V6 closed, air is sucked out from the second space R2 in the second housing 32, creating a vacuum within the second space R2. Note that during this vacuum chamber formation process, the switch SW is in the OFF state, power supply E is cut off to the heater H, and the heater H is in a non-heating state. That is, the pressure in the first space R1 and the second space R2 is set to be the same to prevent the sheet S from becoming wrinkled.

[0039] 4) Heating step (step S4): 7, the heating step is a step in which, while maintaining a vacuum state in the first space R1 in the first housing 31 and the second space R2 in the second housing 32, a switch SW is turned on to energize the heater H from the power source E, thereby causing the heater H to generate heat and heat the wafer W held on the holding surface (upper surface) of the wafer holding table 40 in the first housing 31. At this time, the heat from the heater H is conducted to the wafer W via the wafer holding table 40 to heat the wafer W, and the sheet S containing the thermoplastic resin is heated and softened.

[0040] 5) Adhesion step (step S5): As shown in Figure 8, the bonding process is similar to the previous heating process in that switch SW is turned on to pass electricity from power source E to heater H, causing heater H to generate heat and heat the wafer W held on the holding surface (top surface) of wafer holding table 40 in first housing 31, while pressing sheet S against the surface of wafer W using the difference (differential pressure) between the pressure in first space R1 in first housing 31 and the pressure in second space R2 in second housing 32 to bond sheet S to the surface of wafer W.

[0041] That is, in this bonding step, similarly to the preceding heating step, the switch SW is turned on to heat the wafer W with the heater H, and with the on-off valve V2 of the first introduction part of the first housing 31 closed, the on-off valve V1 of the first suction part is opened to evacuate the first space R1 in the first housing 31, while the on-off valve V5 of the second suction part of the second housing 32 is closed and the on-off valve V6 of the second introduction part is opened. As a result, the internal pressure of the first space R1 of the first housing 31 is maintained at a negative pressure, while air (atmosphere) is sucked into the second space R2 of the second housing 32, and the internal pressure of the second space R2 is maintained at atmospheric pressure. Therefore, if the internal pressure of the first space R1 is p1 (absolute pressure), the internal pressure of the second space R2 is p2 (absolute pressure), and the area of the portion of the sheet S facing the second space R2 is A, a downward force F acts on the upper surface of the sheet S, which is expressed by the following equation based on the difference (differential pressure) Δp (= p2 - p1) between the internal pressures p1 and p2. F=A·Δp=A·(p2-p1) …(1) As described above, when the force F shown in equation (1) acts on the upper surface of the sheet S, the sheet S is pressed against the upper surface of the wafer W by the force F, and the sheet S, which has been heated and softened by the heater H, is adhered to the upper surface of the wafer W. Note that during this adhering process, the on-off valve V3 is closed to stop the suction of the sheet S by the suction source 6, while the on-off valve V7 is open to maintain the suction and holding of the outer periphery of the sheet S by the suction source 13.

[0042] In this bonding process, the sheet S is bonded to the wafer W with the first space R1 of the first housing 31 in a vacuum state, which reduces the chance of air getting in between the sheet S and the wafer W and creating bubbles. Furthermore, the sheet S is heated and softened and is uniformly pressed against the top surface of the wafer W by the force F shown in equation (1) to be bonded to the wafer W, which reduces the likelihood of wrinkles forming in the sheet S.

[0043] 6) Detection process (step S6): The detection process (inspection process) is a process for detecting whether air bubbles have occurred between the adhered sheet S and the wafer W or whether wrinkles have occurred in the sheet S after the sheet S has been adhered to the upper surface of the wafer W in the previous adhering process. In this detection process, as shown in FIG. 9 , the lifting mechanism 80 raises the second housing 32 and the sheet holding table 50, separating them from the first housing 31 and the sheet S. In this detection process, the valves V1 and V5 of the first suction section of the first housing 31 and the second suction section of the second housing 32 are both closed, and the valves V2 and V6 of the first introduction section of the first housing 31 and the second introduction section of the second housing 32 are both opened. The pressures inside the first space R1 of the first housing 31 and the second housing 32 are both maintained at atmospheric pressure. In this detection process, the valves V3 and V7 are both closed, and the sheet S is not suction-held by the suction sources 6 and 13. Furthermore, since the switch SW is turned off and the power supply to the heater H is cut off, the heater H does not heat the sheet S.

[0044] In the detection step, the camera 60, which is a detection unit, captures an image of the sheet S from above, and the captured image is sent to the control unit 70. The control unit 70 then determines, based on the captured image sent from the camera 60, whether or not air bubbles have occurred between the sheet S and the wafer W, or whether or not wrinkles have occurred in the sheet S (step S7 in FIG. 3). In this determination, if the control unit 70 detects at least one of air bubbles or wrinkles (step S7 in FIG. 3: Yes), the control unit 70 carries out the next peeling step (step S8 in FIG. 3), and if neither air bubbles nor wrinkles are detected (step S7 in FIG. 3: No), the control unit 70 ends the bonding of the sheet S (step S11 in FIG. 3).

[0045] The detection unit such as the camera 60 may be provided with a moving mechanism that uses the lifting mechanism 80 to raise the second housing 32 and insert it between the second housing 32 and the sheet S. The detection unit may also be a height measuring device that measures the height of the top surface of the sheet S, or may be configured to measure the top surface of the sheet S that is raised due to air bubbles or wrinkles and detect the presence or absence of air bubbles or wrinkles from the top surface height. The detection process may also be performed visually by a person.

[0046] 7) Peeling step (step S8): As described above, if the control unit 70 detects the occurrence of air bubbles between the sheet S and the wafer W or detects wrinkles in the sheet S in the preceding detection step (step S7 in FIG. 3: Yes), the control unit 70 carries out the peeling step to peel the sheet S from the wafer W. Here, in this embodiment, the lifting mechanism 80, the on-off valve V1 of the first suction unit, the on-off valve V2 of the first introduction unit, the on-off valve V5 of the second suction unit, and the on-off valve V6 of the second introduction unit constitute a peeling mechanism that peels the sheet S, and in the peeling step, the control unit 70 drives and controls the peeling mechanism to peel the sheet S from the wafer W.

[0047] 10, in this peeling step, the second housing 32 and the sheet holding table 50 are lowered by the lifting mechanism 80, and the second housing 32 is connected and integrated with the first housing 31 with the sheet S interposed therebetween (combining step), thereby forming a first space R1 and a second space R2 inside the first housing 31 and the second housing 32, respectively. From this state, the on-off valve V1 of the first suction unit of the first housing 31 is closed, while the on-off valve V2 of the first introduction unit is opened. Then, atmospheric air is introduced into the first space R1 of the first housing 31, so that the internal pressure of the first space R1 is maintained at atmospheric pressure. Furthermore, air in the second space R2 of the second housing 32 is sucked in by the suction source 13, so that the internal pressure of the second space R2 is maintained at negative pressure.

[0048] Therefore, if the internal pressure (absolute pressure) of the first space R1 is p1', the internal pressure (absolute pressure) of the second space R2 is p2', and the area of the portion of the sheet S facing the first space R1 is A, an upward force F' expressed by the following equation acts on the underside of the sheet S based on the difference (differential pressure) Δp' (= p1' - p2') between the internal pressures (absolute pressures) p1' and p2'. F'=A·Δp'=A·(p1'-p2') …(2) As described above, when the force F' shown in equation (2) acts on the lower surface of the sheet S, the sheet S is peeled off from the upper surface of the wafer W by the force F' and, as shown in Fig. 10, the sheet S comes into close contact with the lower surface (holding surface) of the porous member 50A of the sheet holding table 50, with its outer periphery held by suction from the suction source 13. At this time, since the on-off valves V3 and V4 are both closed, the sheet S is not sucked by the suction source 6 and air is not sprayed from the air supply source 8 onto the porous member 50A.

[0049] In other words, the sheet S can be peeled off from the wafer W by causing a force F' to act on the underside of the sheet S due to the pressure difference Δp' between the internal pressure p1' in the first space R1 and the internal pressure p2' in the second space R2, so the branch pipe 4 can be connected to an air supply source (not shown), the second space R2 can be opened to the atmosphere, and air can be supplied to the first space R1 to make the internal pressure p1' positive, thereby generating the force F'.

[0050] 10, when the sheet S is peeled off from the surface of the wafer W, the lifting mechanism 80 raises the second housing 32 and the sheet holding table 50 as shown in FIG. 11, and the second housing 32, the sheet holding table 50, and the sheet S are positioned above the first housing 31 and the wafer W, forming a gap between the first housing 31 and the second housing 32. At this time, because the on-off valves V3 and V7 are both open, the sheet S is sucked and held on the underside of the sheet holding table 50 by the suction sources 6 and 13, and the outer periphery of the sheet S is sucked and held on the underside of the side wall 32B of the second housing 32 by the suction source 13. Furthermore, because the on-off valve V5 of the second suction unit is closed and the on-off valve V6 of the second introduction unit is open, air is introduced into the second space R2 of the second housing 32, and the internal pressure of the second space R2 is maintained at atmospheric pressure.

[0051] As described above, when an air bubble is detected between the sheet S and the wafer W or a wrinkle in the sheet S is detected (step S7: Yes), the control unit 70 drives and controls the peeling mechanism to peel the sheet S from the wafer W. Then, the control unit 70 drives and controls the sheet conveying mechanism 10, which also serves as the sheet ejection mechanism, and in the next sheet ejection process (step S9), ejects the sheet S peeled from the wafer W from the sheet holding table 50.

[0052] 8) Sheet carrying-out process (step S9): 12 , the sheet S, which has been peeled off from the wafer W in the preceding peeling process, is removed from the sheet holding table 50. In this sheet carrying-out process, as shown in FIG. 12 , the sheet holding plate 11 of the sheet conveying mechanism 10, which also serves as the sheet carrying-out mechanism, is introduced into the gap between the first housing 31 and the second housing 32 of the vacuum chamber 30. In this sheet carrying-out process, the on-off valves V3 and V7 are both closed, so the suction sources 6 and 13 do not suck the sheet S. Furthermore, the on-off valve V4 is opened, so that air is supplied from the air supply source 8 to the porous member 50A of the sheet holding table 50 and sprayed into the porous member 50A. As a result, the sheet S is released from the holding surface of the sheet holding table 50 and the underside of the side wall 32B of the second housing 32, is sucked and held on the sheet holding plate 11 of the sheet conveying mechanism 10, and is then delivered from the sheet holding table 50 to the sheet conveying mechanism 10.

[0053] As described above, the sheet S, which has been peeled off from the wafer W and handed over from the sheet holding table 50 to the sheet conveying mechanism 10 and sucked and held on the sheet holding plate 11 of the sheet conveying mechanism 10, is carried out of the sheet holding table 50 and discarded by the sheet conveying mechanism 10. Then, in the next sheet holding step (step S10 in FIG. 3), a new sheet S is held by the sheet conveying mechanism 10.

[0054] 9) Sheet holding process (step S10): The sheet holding step is a step of discarding the sheet S carried out from the sheet holding table 50 by the sheet conveying mechanism 10 in the preceding sheet carrying-out step (step S9), and holding a new sheet S by suction onto the sheet holding plate 11 of the sheet conveying mechanism 10, and holding it on the sheet holding table 50 of the sheet sticking device 1 as shown in Fig. 4. Note that this sheet holding step is the same as that described in Fig. 4, and therefore a repeated description thereof will be omitted.

[0055] 3, after the sheet holding step is performed, the vacuum chamber forming step (step S3) shown in FIG. 6, the heating step (step S4) shown in FIG. 7, the adhering step (re-adhering step) (step S5) shown in FIG. 8, and the detection step (step S6) shown in FIG. 9 are performed, and the control unit 70 determines whether or not air bubbles are detected between the adhered sheet S and the wafer W, or whether or not wrinkles are detected in the adhered sheet S (step S7). If the result of this determination is that neither air bubbles nor wrinkles are detected (step S7: No), the adhering of the sheet S is completed (step S11), and if at least one of air bubbles and wrinkles is detected (step S7: Yes), the steps S8 to S10 and steps S3 to S7 are repeated until neither air bubbles nor wrinkles are detected.

[0056] As described above, according to the sheet adhering device 1 of this embodiment, the sheet S adhered to the wafer W is imaged by the camera 60, and based on the image, the control unit 70 determines whether or not air bubbles are detected between the wafer W and the sheet S, or whether wrinkles are detected on the sheet S. If at least one of air bubbles or wrinkles is detected, the sheet S is peeled off from the wafer W by the sheet peeling mechanism, and the peeled sheet S is transported away by the sheet conveying mechanism 10. Thereafter, a new sheet S is transported to the sheet adhering device 1, and the series of operations from adhering the sheet S to detecting air bubbles and wrinkles are performed automatically without human intervention, thereby achieving the effects of improving workability and efficiency and reducing labor.

[0057] Furthermore, in the sheet bonding device 1 according to this embodiment, in the peeling process of peeling the sheet S, in which air bubbles or wrinkles have been detected, from the wafer W, the first housing 31 and the second housing 32 are joined together with the sheet S interposed therebetween, and the on-off valve V5 of the second suction unit is opened to suck air from the second housing 32 using the suction source 13, thereby creating a negative internal pressure in the second space R2, and the on-off valve V2 of the first air introduction unit is opened to introduce air (atmosphere) into the first space R1 in the first housing 31, thereby maintaining the internal pressure of the first space R1 at atmospheric pressure. As a result, a force acts on the sheet S to peel it from the wafer W due to the internal pressure difference (differential pressure) between the first space R1 and the second space R2. This also provides the effect of easily peeling the sheet S from the wafer W by utilizing this force.

[0058] The configuration of the sheet sticking device 1 according to the present invention may be the configuration shown in Fig. 13, which is upside down from the arrangement shown in Fig. 2. In Fig. 13, the same elements as those shown in Fig. 2 are denoted by the same reference numerals, and a repeated description of these elements will be omitted.

[0059] Furthermore, the present invention is not limited to the application of the above-described embodiments, and it goes without saying that various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0060] 1: Sheet application device, 2: Piping, 3: Suction source, 4: Branch pipe, 5: Piping, 6: Suction source, 7: Branch pipe, 8: Air supply source, 9: Piping, 10: Sheet transport mechanism (sheet discharge mechanism), 11: sheet holding plate, 12: driving mechanism, 20: wafer transport mechanism, 21: wafer holding plate, 22: suction pad, 23: driving mechanism, 30: vacuum chamber, 31: first housing, 31A: bottom wall of first housing, 31a: ventilation hole, 32: second housing, 32A: upper wall of second housing, 32B: side wall of second housing, 32a: ventilation hole, 32b: suction groove, 32c: communication passage, 33: support shaft, 33a: communication passage, 34: seal member, 40: wafer holding table, 41: electric cord, 50: sheet holding table, 50A: porous member, 60: camera (detection unit), 70: control unit, 80: lifting mechanism, D: device, E: power supply, H: heater, L1, L2: street, R1: first space, R2: Second space, S: Seat, SW: Switch, V1 to V7: On-off valve, W: Wafer

Claims

1. A sheet adhering device for adhering a sheet to a wafer, a wafer holding table that holds a wafer; a first housing having a recess for accommodating the wafer holding table; a first suction unit that sucks air from within the first housing; an air introduction section that introduces air into the first housing; a sheet holding table for holding the sheet; a second housing having a recess for accommodating the sheet holding table and coupled to the first housing with the sheet interposed therebetween; a second suction section that sucks air from within the second housing; a sheet peeling mechanism for peeling the sheet from the wafer; a detection unit that detects air bubbles between the sheet attached to the wafer and the wafer or wrinkles in the sheet; a sheet carrying-out mechanism that carries out the sheet peeled off from the wafer by the sheet peeling mechanism from the sheet holding table; a control unit that, when the detection unit detects an air bubble between the sheet and the wafer or a wrinkle in the sheet, drives and controls the sheet peeling mechanism and the sheet carrying-out mechanism to peel the sheet from the wafer and carry out the peeled sheet from the sheet holding table; A sheet sticking device comprising:

2. The control unit A sheet bonding device as described in claim 1, characterized in that, when the first housing and the second housing are combined with the sheet interposed therebetween, the second suction section sucks air from within the second housing to make the internal pressure of the second housing negative, and the air introduction section introduces air into the first housing to maintain the internal pressure of the first housing at atmospheric pressure.

3. A sheet peeling method for peeling off a sheet that is larger than the wafer and that is attached to the wafer, comprising: a wafer holding step of holding a wafer on a wafer holding table accommodated in a recess of the first housing; a combining step of combining a second housing having a recess and the first housing with a sheet interposed therebetween; a peeling step of peeling the sheet from the wafer by making the internal pressure of the first housing a positive pressure higher than the internal pressure of the second housing; A sheet peeling method comprising:

4. A sheet adhering method for adhering a sheet to a wafer, comprising: a wafer holding step of holding a wafer on a wafer holding table accommodated in a recess of the first housing; a sheet holding step of holding a sheet on a sheet holding table accommodated in a recess of the second housing; a combining step of combining the first housing and the second housing with a sheet interposed therebetween; a sheet adhering step of adhering a sheet to the wafer by making the internal pressure of the first housing a negative pressure lower than the internal pressure of the second housing; an inspection step for inspecting the sheet for the presence of bubbles or wrinkles; a re-attaching step in which, if no bubbles or wrinkles are found in the sheet in the inspection step, the processing is terminated, and if bubbles or wrinkles are found in the sheet, the sheet is peeled off from the wafer using the sheet peeling method of claim 3, and then a new sheet is held on the sheet holding table and attached to the wafer; A sheet adhering method comprising:

Images