Protective member forming apparatus and method for forming protective member

Abstract

To excellently detect whether or not a wafer remains on a glass stage.SOLUTION: In a case where continuous processing is temporarily stopped when holding of a wafer 100 by a wafer holding pad becomes difficult, a detection unit 71 detects the presence or absence of the wafer 100 on a glass table 21 by using a light amount measured by a light amount measuring unit 80. Accordingly, the presence or absence of the wafer on the glass table 21 can be clearly detected. Therefore, even when the wafer 100 that cannot be properly held by the wafer holding pad remains on the glass table 21, it is possible to prevent waste of the wafer 100, a sheet S, and a liquid resin when continuous processing is resumed, the sheet S is placed on the wafer 100, and the liquid resin is supplied onto the sheet S.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a protective member forming apparatus and a protective member forming method. [Background technology]

[0002] As disclosed in Patent Documents 1 and 2, there is a wafer manufacturing process in which an ingot is sliced ​​to form sliced ​​wafers, and both sides of the sliced ​​wafers are ground to manufacture the wafers. In this process, while one side of the sliced ​​wafer is ground, a protective member is formed on the other side by spreading and hardening a liquid resin.

[0003] In the protective member forming device that forms this protective member, a sheet is placed on a glass stage, liquid resin is supplied onto the sheet, and the liquid resin is spread by the wafer and hardened, thereby forming a protective member on the wafer.

[0004] The wafer with the protective member formed thereon is then suction-held by a wafer transport mechanism and transported from the glass stage to the cutting stage, where a circular sheet is cut along the outer periphery of the wafer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-155297 [Patent Document 2] Japanese Patent Publication No. 2020-188230 Summary of the Invention [Problem to be solved by the invention]

[0006] The wafer transport mechanism of the above-mentioned protective member forming apparatus may have difficulty in suction-holding the wafer due to, for example, large warpage or undulation of the wafer, making it difficult to transport the wafer from the glass stage.

[0007] In such a state, a message to remove the wafer from the glass stage is displayed on the touch panel to notify the operator.

[0008] However, sometimes the worker continues forming the protective member without removing the wafer, and in this case, the wafer, sheet, and liquid resin may be wasted if another sheet is placed on top of the wafer left on the glass stage.

[0009] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to accurately detect whether or not a wafer remains on a glass stage when a protective member is formed on the wafer. [Means for solving the problem]

[0010] The protective member forming apparatus of the present invention (the present protective member forming apparatus) is a protective member forming apparatus comprising: a glass table for placing a sheet with an area larger than one side of a wafer; a holding table that holds the wafer above the glass table; a liquid resin supply unit that supplies ultraviolet-curable liquid resin to the sheet placed on the glass table; a lifting mechanism that spreads the liquid resin over the entire one side of the wafer by bringing the glass table and the holding table closer together; a UV light source that forms a protective member made of the cured liquid resin on one side of the wafer by irradiating ultraviolet light onto the liquid resin from the glass table side; and a wafer transport mechanism that transports the wafer on which the protective member has been formed from the glass table, and further comprises a light intensity measuring unit that measures the amount of ultraviolet light irradiated from the UV light source and transmitted through the glass table, and a detection unit that detects the presence of a wafer on the glass table when the light intensity measured by the light intensity measuring unit is below a predetermined threshold.

[0011] The protective member forming apparatus may further include a notification unit that notifies an operator that a wafer is present on the glass table when the detection unit detects that a wafer is present on the glass table.

[0012] The protective member forming method of the present invention (the present forming method) is a method of forming a protective member using the protective member forming apparatus, and includes a protective member forming process of forming a protective member on one side of a wafer, and a wafer detection process, which is carried out while the protective member forming process is stopped, in which the light quantity measuring unit measures the amount of ultraviolet light irradiated from the UV light source and transmitted through the glass table, and the detection unit detects the presence or absence of a wafer on the glass table based on the measured light quantity.If the detection unit detects that a wafer is present on the glass table in the wafer detection process, a notification process is carried out by the notification unit of the protective member forming apparatus to notify an operator that a wafer is present, and if the detection unit detects that a wafer is not on the glass table in the wafer detection process, the protective member forming process is carried out. [Effects of the Invention]

[0013] In the protective member forming apparatus and method, the detector detects the presence or absence of a wafer on the glass table using the amount of ultraviolet light measured by the light quantity measuring unit. This makes it possible to clearly detect the presence or absence of a wafer on the glass table. Therefore, it is possible to prevent, for example, a situation in which a wafer that is difficult to hold with the wafer transport mechanism is left on the glass table, but a sheet is placed on the wafer and liquid resin is then supplied onto the sheet, resulting in the wasting of the wafer, sheet, and liquid resin. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a perspective view showing a configuration of a protective member forming device. [Figure 2] 4 is a cross-sectional view showing the configuration of a sheet holding mechanism and a wafer holding pad. FIG. [Figure 3] 3 is a cross-sectional view showing the configuration of a sheet holding mechanism and a light quantity measuring unit. FIG. [Figure 4] FIG. 2 is a perspective view showing the configuration of a sheet holding mechanism and a light quantity measuring unit. DETAILED DESCRIPTION OF THE INVENTION

[0015] The protective member forming apparatus 1 shown in FIG. 1 is an apparatus for forming a protective member including a sheet and a resin obtained by spreading and hardening a liquid resin over the entire surface of one side of a wafer 100.

[0016] The wafer 100 is, for example, a disk-shaped as-sliced ​​silicon wafer, and has a front surface 101 and a back surface 102. The back surface 102 and the front surface 101 of the wafer 100 correspond to examples of one side and the other side of the wafer 100, respectively.

[0017] The protective member forming device 1 comprises a housing 200, an apparatus base 201 arranged within the housing 200, a column 202 erected on the apparatus base 201, a support base 203 arranged adjacent to the apparatus base 201, a table base 204 also arranged adjacent to the apparatus base 201, and a cassette storage body 205 connected to the rear end side of the housing 200.

[0018] The cassette housing body 205 has two housing spaces 206 and 207. A cassette 208 is disposed in the housing space 206, and the cassette 208 houses a plurality of wafers 100 before the protective member is formed thereon. A cassette 209 is disposed in the housing space 207, and the cassette 209 houses wafers 100 after the protective member is formed thereon.

[0019] A temporary placement mechanism 6 and a cutting device 8 located below the temporary placement mechanism 6 are disposed on the table base 204 on the -Y direction side of the cassette housing main body 205. The temporary placement mechanism 6 is a center detection unit that detects the center position of the wafer 100. The cutting device 8 includes a cutting table and cuts off excess portions of the sheet S along the outline of the wafer 100.

[0020] A first transport mechanism 4 is disposed between the cassette housing main body 205 and the temporary placement mechanism 6. The first transport mechanism 4 has a first robot hand 14 capable of holding the wafer 100, and transports the wafer 100 into and out of the cassettes 208 and 209. That is, the first transport mechanism 4 transports the wafer 100, on which the protective member has not yet been formed, out of the cassette 208 and into the temporary placement mechanism 6. Furthermore, the first transport mechanism 4 transports the wafer 100, on which the protective member has been formed, out of the cutting device 8 and into the cassette 209.

[0021] A second transfer mechanism 9 is disposed on the −Y direction side of the first transfer mechanism 4. The second transfer mechanism 9 has a second robot hand 10 capable of holding a wafer 100 and a wafer holding pad 90. The second robot hand 10 is used to carry the wafer 100 out of the temporary placement mechanism 6 and transfer it to the holding table 52 of the wafer holding mechanism 50. The wafer holding pad 90 is also used to retrieve the wafer 100 on which the protective member has been formed and carry it into the cutting device 8.

[0022] The device base 201 is equipped with a sheet supply mechanism 16 having a roll portion 17 containing a rolled sheet S, a sheet holding mechanism 20 including a glass table 21 that holds the sheet S, and a sheet conveying mechanism 30.

[0023] The sheet conveying mechanism 30 places a sheet S having an area larger than the area of ​​the back surface 102 of the wafer 100 on the glass table 21. The sheet conveying mechanism 30 has a frame-shaped support member 31, an air bubble removal roller 35 attached to the support member 31, a sheet gripping portion 32 attached to the support member 31, and a moving member 33 that moves the support member 31 along the Y-axis direction.

[0024] In the sheet conveying mechanism 30, the sheet S wound around the roll portion 17 is gripped by the sheet gripping portion 32 and pulled in the +Y direction by the moving member 33, and positioned on the glass table 21. Then, the air between the sheet S and the glass table 21 is expelled by the air de-bubbling roller 35, and the sheet S is cut to a predetermined size. The cut sheet S has an area larger than the area of ​​the back surface 102 of the wafer 100. This allows the sheet conveying mechanism 30 to place the sheet S on the glass table 21 of the sheet holding mechanism 20.

[0025] As shown in FIG. 2, the sheet holding mechanism 20 has a glass table 21 and a table support base 24 that supports the glass table 21. The glass table 21 is a table for placing a sheet S having an area larger than the back surface 102, which is one surface of the wafer 100. The glass table 21 is made of glass such as quartz glass, and has a sheet placement surface 22 on which the sheet S is placed. The sheet S is placed on this sheet placement surface 22 by a sheet conveying mechanism 30.

[0026] The table support base 24 has a cylindrical portion 25 as a support frame that supports the glass table 21 from the sides, and a bottom plate portion 26 that closes the bottom of the cylindrical portion 25. The upper surface of the cylindrical portion 25 is formed to be flush with the sheet placing surface 22. As shown in Figures 1, 2 and 4, a ring-shaped air outlet 27 is formed on the upper surface of the cylindrical portion 25, and further, a plurality of (four in this embodiment) hole-shaped sheet suction ports 28 are formed outside the air outlet 27.

[0027] 2, the sheet suction port 28 is connected to a suction source 302 via a suction path 281 provided inside the cylindrical portion 25, a fluid passage 272 connected to the suction path 281, and a suction valve 283 connected to the fluid passage 272. When the suction valve 283 is opened, the sheet suction port 28 is connected to the suction source 302. This allows the sheet placing surface 22 to suck and hold the sheet S using the suction force of the suction source 302.

[0028] The air outlet 27 is connected to an air supply source 301 via an air flow path 271 provided inside the cylindrical portion 25, a fluid passage 272 connected to the air flow path 271, and an air valve 273 formed in the fluid passage 272. When the air valve 273 is opened, the air outlet 27 is connected to the air supply source 301, and air is ejected from the air outlet 27. As a result, the sheet S held on the sheet placement surface 22 is separated from the sheet placement surface 22.

[0029] 1, a liquid resin supply unit 40 is provided near the glass table 21 to supply ultraviolet-curable liquid resin to the sheet S placed on the glass table 21. The liquid resin supply unit 40 has a liquid resin supply nozzle 41 for supplying the liquid resin to the sheet S, and a dispenser 42 for sending a predetermined amount of liquid resin to the liquid resin supply nozzle 41. The liquid resin supply nozzle 41 is connected to the dispenser 42 via a connecting pipe (not shown).

[0030] In this embodiment, the liquid resin supply nozzle 41 is provided on the support member 31 of the sheet conveying mechanism 30 and moves in the Y-axis direction together with the support member 31. The liquid resin supply unit 40 supplies liquid resin to the center of the upper surface of the sheet S held on the glass table 21 using the liquid resin supply nozzle 41.

[0031] This liquid resin is an ultraviolet-curable resin used to form a protective member that protects the entire surface of the front surface 101 of the wafer 100. In forming the protective member, the back surface 102 of the wafer 100 is pressed from above onto the liquid resin supplied onto a sheet S placed on the glass table 21, and the liquid resin is spread over the entire surface of the back surface 102, and then the liquid resin is cured.

[0032] On the −Y direction side of the column 202, there are arranged a wafer holding mechanism 50 that holds the wafer 100 transferred from the second transfer mechanism 9, and an elevation mechanism 60 that raises and lowers the wafer holding mechanism 50.

[0033] The wafer holding mechanism 50 has a support structure 51 attached to a lifting mechanism 60, a holding table 52 attached to the support structure 51, an extendable peripheral connection part 53 disposed on the outer periphery of the holding table 52, and a load detection part 54 that detects the load acting on the holding table 52. The support structure 51 is attached to the lifting mechanism 60 while supporting the holding table 52, and is moved in the Z-axis direction by the lifting mechanism 60.

[0034] Holding table 52 of wafer holding mechanism 50 holds wafer 100 above glass table 21 and is disposed opposite glass table 21. Holding table 52 has a wafer holding surface (not shown) made of, for example, a porous material, and by connecting this wafer holding surface to a suction source (not shown), front surface 101, the other side of wafer 100, can be held by suction.

[0035] The outer peripheral connecting portion 53 has, for example, a bellows shape, and can form a sealed space together with the sheet S and the wafer 100 by coming into contact with the sheet S when the wafer holding mechanism 50 is lowered.

[0036] 1 spreads the liquid resin over the entire back surface 102, which is one surface of the wafer 100, by bringing the glass table 21 and the holding table 52 closer to each other. In this embodiment, the lifting mechanism 60 is configured to raise and lower the wafer holding mechanism 50, including the holding table 52, with respect to the glass table 21. That is, the lifting mechanism 60 brings the wafer holding mechanism 50, including the holding table 52, closer to the glass table 21 along the Z-axis direction, thereby spreading the liquid resin supplied onto the sheet S held on the glass table 21 over the entire back surface 102 of the wafer 100 held on the holding table 52.

[0037] The lifting mechanism 60 includes a ball screw 61 extending in the Z-axis direction, a motor 62 connected to one end of the ball screw 61, a pair of guide rails 63 extending parallel to the ball screw 61, a lifting plate 64 to which the wafer holding mechanism 50 is attached, and an encoder 65 for detecting the amount of rotation (e.g., the number of rotations and the rotation angle) of the ball screw 61. The lifting plate 64 is slidably installed relative to the pair of guide rails 63. A nut portion (not shown) is formed on the lifting plate 64. The ball screw 61 is threadedly engaged with this nut portion.

[0038] In the lifting mechanism 60, the ball screw 61 is rotated by the motor 62, whereby the lifting plate 64 moves in the Z-axis direction along a pair of guide rails 63 together with the wafer holding mechanism 50, which includes the holding table 52 that holds the wafer 100. This causes the holding table 52 to rise and fall along the Z-axis direction that is approximately perpendicular to the glass table 21. At this time, the encoder 65 recognizes the amount of rotation of the ball screw 61 and detects the height position of the holding table 52 based on the recognition result. In this way, the lifting mechanism 60 can spread the liquid resin accumulated on the glass table 21 over the entire back surface 102 of the wafer 100 by raising and lowering the holding table 52 that holds the wafer 100.

[0039] As shown in FIG. 2, the sheet holding mechanism 20 is provided with a UV light source 29 on a bottom plate portion 26 arranged below the glass table 21, which irradiates ultraviolet light onto the liquid resin on the sheet mounting surface 22 that is spread over the entire back surface 102 of the wafer 100.

[0040] The UV light source 29 is an ultraviolet light irradiation unit that irradiates the liquid resin with ultraviolet light from the glass table 21 side, thereby forming a protective member made of the cured liquid resin on the back surface 102 of the wafer 100. That is, the UV light source 29 irradiates the liquid resin that has been pressed and spread over the entire back surface 102 of the wafer 100 with ultraviolet light through the glass table 21, thereby curing the liquid resin. As a result, a protective member 104 including the cured liquid resin 105 and the sheet S is formed on the back surface 102 of the wafer 100.

[0041] The wafer 100 on which the protective member 104 is formed is collected by the wafer holding pad 90 of the second transport mechanism 9 and carried into the cutting device 8. In this manner, the second transport mechanism 9 (wafer holding pad 90) is an example of a wafer transport mechanism that transports (carries out) the wafer 100 on which the protective member 104 is formed from the glass table 21 of the sheet holding mechanism 20.

[0042] Here, we will explain the configuration of the wafer holding pad 90 in the second transfer mechanism 9. As shown in Fig. 2, the wafer holding pad 90 is connected to a moving mechanism 99 of the second transfer mechanism 9 that moves the wafer holding pad 90 in the horizontal and vertical directions.

[0043] As shown in FIGS. 1 and 2, the wafer holding pad 90 has a disk-shaped pad portion 91 and a plurality of (four in this embodiment) outer periphery suction portions 93 arranged on the outer side of the pad portion 91. The pad portion 91 has a wafer holding surface 92 on its lower surface. This wafer holding surface 92 suction-holds the front surface 101 of the wafer 100 on which the protective member 104 is formed and which is placed on the sheet placing surface 22 of the glass table 21. The outer periphery suction portion 93 has a suction cup and is a member for suction-holding the sheet S of the protective member 104 formed on the wafer 100.

[0044] The wafer holding surface 92 includes a circular or ring-shaped recess 921 (suction groove) and a ring packing 922 arranged on the outer periphery of the recess 921. The recess 921 and the outer periphery suction portion 93 are connected to a suction source 302 via a fluid passage 94 provided to pass through the pad portion 91, a suction path 95 connected to the fluid passage 94, and a suction valve 96 provided in the suction path 95. In the wafer holding surface 92, when the recess 921 is ring-shaped, a ring packing may also be arranged on the inner periphery of the recess 921 (suction groove).

[0045] When the suction valve 96 is opened while the outer periphery suction portion 93 is in contact with the sheet S and the wafer holding surface 92 is in contact with the front surface 101 of the wafer 100, the outer periphery suction portion 93 is connected to the suction source 302, and the sheet S can be suction-held. Furthermore, the recess 921 of the wafer holding surface 92 is connected to the suction source 302, and the sealed space surrounded by the recess 921, the ring packing 922, and the front surface 101 of the wafer 100 is depressurized. This allows the wafer holding surface 92 to suction-hold the wafer 100 using the suction force of the suction source 302.

[0046] In this way, the wafer 100 on which the protective member 104 is formed is suction-held by the wafer holding pad 90 having the outer periphery suction portion 93 and the wafer holding surface 92. Then, by moving the wafer holding pad 90 in the horizontal and vertical directions using the moving mechanism 99, the wafer 100 can be carried out from the glass table 21 and into the cutting device 8 shown in FIG.

[0047] A pressure sensor 303 is provided in the fluid passage 94. The pressure sensor 303 detects the pressure value of this fluid passage 94. In this embodiment, for example, when the suction valve 96 is opened to connect the recess 921 of the wafer holding surface 92 and the outer periphery suction portion 93 to the suction source 302, if the pressure value of the fluid passage 94 measured by the pressure sensor 303 becomes equal to or less than a predetermined threshold, it is determined that the wafer 100 on which the protective member 104 is formed is held by the wafer holding pad 90.

[0048] Furthermore, the recess 921 of the wafer holding surface 92 and the outer periphery suction portion 93 are connected to an air supply source 301 via a fluid passage 94, an air flow path 97 connected to the fluid passage 94, and an air valve 98 provided in the air flow path 97. After the wafer 100 held on the wafer holding pad 90 is carried into the cutting device 8, the suction valve 96 is closed and the air valve 98 is opened, thereby connecting the recess 921 and the outer periphery suction portion 93 to the air supply source 301, separating the wafer 100 from the wafer holding surface 92 and separating the sheet S from the outer periphery suction portion 93.

[0049] 1, the excess portion of the sheet S is cut along the outer shape of the loaded wafer 100. Thereafter, the wafer 100 is carried out of the cutting device 8 by the first transport mechanism 4 and loaded into a cassette 209.

[0050] 1 and 4, a light quantity measuring unit 80 is disposed near the glass table 21. The light quantity measuring unit 80 measures the quantity of ultraviolet light that is irradiated (emitted) from the UV light source 29 and transmitted through the glass table 21. As shown in FIGS. 3 and 4, the light quantity measuring unit 80 has an arm 81 extending horizontally, a support column 82 that supports the arm 81 and extends vertically, and a rotation motor 83.

[0051] The rotation motor 83 rotates the arm 81 about a rotation axis 821 in the Z-axis direction that passes through the support column 82. As shown in FIG. 3, a plurality of optical sensors 84 capable of measuring the amount of received ultraviolet light are provided on the underside of the arm 81.

[0052] In the protective member forming apparatus 1, for example, after forming protective members 104 on all wafers 100 in one cassette 208, the arm 81 is rotated to position the optical sensor 84 on the glass table 21, and the amount of ultraviolet light emitted from the UV light source 29 and transmitted through the glass table 21 can be measured, thereby inspecting the light emission state of the UV light source 29.

[0053] 1, the protective member forming apparatus 1 is provided with a touch panel 5, for example, on the side surface of the cassette housing main body 205. The touch panel 5 displays various information related to the protective member forming apparatus 1. The touch panel 5 is also used to set various information. In this way, the touch panel 5 functions as an input member for inputting information, and also as a display member (notification unit) for displaying (notifying) information.

[0054] The protective member forming apparatus 1 also includes a control unit 7 that controls each component of the protective member forming apparatus 1. The control unit 7 includes a CPU that performs calculations according to a control program, and a storage medium such as a memory. The control unit 7 also includes a detection unit 71. Below, the function of the detection unit 71 and a method for forming a protective member using the protective member forming apparatus 1 controlled by the control unit 7 will be described.

[0055] The method for forming a protective member according to this embodiment includes a protective member forming step, a light quantity measuring step, and a notification step. The protective member forming step is a step of forming a protective member on the back surface 102 of the wafer 100, and includes a sheet holding step, a liquid resin supplying step, a wafer holding step, an expanding step, a curing step, and a carrying-out step. First, each step of the protective member forming process will be described.

[0056] [Sheet holding process] In the protective member forming process, a sheet holding process is first performed. In this process, the control unit 7 controls the sheet conveying mechanism 30 shown in FIG. 1 to clamp the sheet S and move it in the Y-axis direction, thereby pulling the sheet S out of the roll unit 17 and placing it on the sheet placing surface 22 of the glass table 21. Furthermore, the control unit 7 causes the sheet placing surface 22 to suction and hold the sheet S.

[0057] [Liquid resin supply process] After the sheet holding step, a liquid resin supplying step is performed. In this step, the control unit 7 supplies a preset amount of liquid resin from the liquid resin supply nozzle 41 provided on the support member 31 of the sheet conveying mechanism 30 to the center of the upper surface of the sheet S held by suction on the sheet placing surface 22. The preset amount of liquid resin is, for example, an amount that allows the liquid resin to spread over the entire back surface 102 of the wafer 100.

[0058] [Wafer holding process] After the liquid resin supplying step, the wafer holding step is carried out. In this step, the control unit 7 controls the first transport mechanism 4 to take out one wafer 100, on which a protective member has not yet been formed, from the cassette 208 and carry it into the temporary placement mechanism 6. After that, the control unit 7 detects the center position of the wafer 100 in the temporary placement mechanism 6, and then uses the second robot hand 10 of the second transport mechanism 9 to carry the wafer 100 out of the temporary placement mechanism 6 and hand it over to the wafer holding mechanism 50.

[0059] In the wafer holding mechanism 50 , the holding table 52 holds the front surface 101 of the wafer 100 by suction so that the back surface 102 of the wafer 100 faces the sheet placement surface 22 of the glass table 21 . The wafer holding step may be performed in parallel with the sheet holding step and the liquid resin supplying step.

[0060] [Extended process] After the wafer holding step, the expansion step is performed. In this step, the control unit 7 controls the lifting mechanism 60 to lower the wafer holding mechanism 50. That is, the control unit 7 moves the wafer holding mechanism 50 closer to the sheet placing surface 22 along the Z-axis direction perpendicular to the sheet placing surface 22 of the glass table 21. As the wafer holding mechanism 50 lowers, the holding table 52 is also lowered, and the back surface 102 of the wafer 100, which is suction-held on the holding table 52, comes into contact with the liquid resin on the sheet S, which is suction-held on the glass table 21.

[0061] Then, the control unit 7 uses the lifting mechanism 60 to press the back surface 102 of the wafer 100 held by the holding table 52 against the liquid resin on the sheet S with a predetermined pressing force. In this way, the control unit 7 spreads the liquid resin over the entire back surface 102 of the wafer 100. At this time, the control unit 7 adjusts the pressing force of the wafer 100 based on the value of the load applied to the holding table 52 measured by the load detection unit 54.

[0062] Thereafter, the control unit 7 releases the suction holding of the wafer 100 by the holding table 52. As a result, the wafer 100 is placed on the sheet placing surface 22 of the glass table 21 via the sheet S and the liquid resin. After the wafer 100 is placed on the sheet placing surface 22, the control unit 7 controls the lifting mechanism 60 to raise the holding table 52 along the Z-axis direction.

[0063] [Curing process] After the spreading step, a curing step is carried out. In this step, the control unit 7 uses the UV light source 29 of the sheet holding mechanism 20 shown in FIG. 2 to irradiate the liquid resin spread over the entire back surface 102 of the wafer 100 with ultraviolet light from the glass table 21 side, thereby curing the liquid resin. As a result, the liquid resin is cured on the back surface 102 of the wafer 100, and as shown in FIG. 2, a protective member 104 including the cured liquid resin 105 and the sheet S is formed over the entire back surface 102 of the wafer 100.

[0064] [Export process] After the curing step, a carrying-out step is carried out. In this step, the control unit 7 carries out the wafer 100 on which the protective member 104 is formed, which is placed on the glass table 21, by using the wafer holding pad 90 of the second transport mechanism 9, as shown in FIG.

[0065] Specifically, the control unit 7 controls the moving mechanism 99 of the second transport mechanism 9 to move the wafer holding pad 90 above the wafer 100 placed on the glass table 21, and then lowers the wafer holding pad 90 to bring its wafer holding surface 92 into contact with the front surface 101, which is the upper surface of the wafer 100, and bring the outer periphery suction unit 93 into contact with the sheet S. The control unit 7 then opens the suction valve 96 to connect the wafer holding surface 92 (recess 921) and the outer periphery suction unit 93 to the suction source 302, thereby suction-holding the front surface 101 of the wafer 100 with the wafer holding surface 92 and suction-holding the sheet S with the outer periphery suction unit 93. As a result, the wafer 100 on which the protective member 104 is formed is suction-held by the wafer holding pad 90.

[0066] Furthermore, the control unit 7 controls the moving mechanism 99 to move the wafer holding pad 90 holding the wafer 100, thereby removing the wafer 100 from the glass table 21 and loading it into the cutting device 8 shown in Figure 1.

[0067] Thereafter, the control unit 7 uses the cutting device 8 to cut off the excess portion of the sheet S on the protective member 104 of the wafer 100. Furthermore, the control unit 7 controls the first transport mechanism 4 to carry the wafer 100 out of the cutting device 8 and store it in the cassette 209.

[0068] In the protective member forming process of this embodiment, for example, the above-described sheet holding process, liquid resin supplying process, wafer holding process, expanding process, hardening process, and carrying-out process are continuously performed on a plurality of wafers 100 (continuous processing).

[0069] In the unloading process, when the suction valve 283 is opened to connect the wafer holding surface 92 to the suction source 302 in order to hold the wafer 100 by suction with the wafer holding pad 90, if the wafer 100 is significantly warped or swollen, it may be difficult for the wafer holding surface 92 to hold the wafer 100 by suction. In this case, a large amount of air enters the fluid passage 94 from the wafer holding surface 92, and the pressure value of the fluid passage 94 measured by the pressure sensor 303 (the negative pressure value of the wafer holding surface 92) does not fall below a predetermined threshold value.

[0070] Therefore, the control unit 7 can determine that the wafer 100 is not being held by the wafer holding surface 92 if the measurement value of the pressure sensor 303 does not fall below a predetermined threshold even when the wafer holding surface 92 is connected to the suction source 302.

[0071] In this case, the control unit 7, for example, temporarily suspends the continuous processing. Then, the control unit 7 closes the suction valve 283 and opens the air valve 273 to separate the wafer 100 from the wafer holding pad 90, and then uses the moving mechanism 99 to place the wafer holding pad 90 at a location away from the glass table 21. Then, the control unit 7 uses the touch panel 5 to display a message to the operator requesting that the operator remove the wafer 100 from the glass table 21 because it is difficult to hold the wafer 100 on the glass table 21.

[0072] Thereafter, the control unit 7 resumes the continuous processing of the wafers 100 based on an instruction to resume from the operator using the touch panel 5, for example. At this time, the operator may issue a command to resume without removing the wafer 100 from the glass table 21. Therefore, in this embodiment, when the control unit 7 resumes continuous processing, the control unit 7 uses the detection unit 71 and the light quantity measurement unit 80 to detect whether the wafer 100 is present on the glass table 21.

[0073] Specifically, before resuming continuous processing, the control unit 7 performs a wafer detection step in which the light quantity measuring unit 80 measures the amount of ultraviolet light emitted from the UV light source 29 and transmitted through the glass table 21, and the detection unit 71 detects the presence or absence of the wafer 100 on the glass table 21 based on the measured light quantity.

[0074] Specifically, as shown in Fig. 3, the control unit 7 controls the rotation motor 83 of the light quantity measuring unit 80 to rotate the arm 81, thereby placing the optical sensor 84 above the glass table 21. Thereafter, the control unit 7 uses the UV light source 29 of the sheet holding mechanism 20 to irradiate ultraviolet light onto the glass table 21 from below. Then, the detection unit 71 uses the optical sensor 84 of the light quantity measuring unit 80 to measure the amount of ultraviolet light irradiated from the UV light source 29 and transmitted through the glass table 21. Furthermore, the detection unit 71 detects the presence or absence of a wafer 100 on the glass table 21 based on the amount of light measured by the light quantity measuring unit 80.

[0075] For example, when the amount of light measured by the light amount measuring unit 80 is greater than a predetermined threshold, the detecting unit 71 determines that there is nothing blocking the ultraviolet light on the glass table 21 and detects that there is no wafer 100 on the glass table 21. In this case, the control unit 7 resumes the continuous processing, for example, as instructed by the operator. That is, when the detecting unit 71 detects that there is no wafer 100 on the glass table 21 in the wafer detection step, the control unit 7 carries out (resumes) the protective member forming step.

[0076] On the other hand, when the amount of light measured by the light amount measuring unit 80 is equal to or less than the predetermined threshold, the detecting unit 71 determines that the wafer 100 is present on the glass table 21 and that the ultraviolet light is being blocked by the wafer 100. In other words, the detecting unit 71 detects that the wafer 100 is present on the glass table 21 when the amount of light measured by the light amount measuring unit 80 is equal to or less than the predetermined threshold.

[0077] In this case, the control unit 7 carries out a notification step while maintaining the paused state of the continuous processing. In this step, the control unit 7 notifies the operator that the wafer 100 remains on the glass table 21 using the touch panel 5. That is, when the detection unit 71 detects that the wafer 100 is present on the glass table 21 in the wafer detection step, the control unit 7 notifies the operator that the wafer 100 is present using the touch panel 5. In this way, when the detection unit 71 detects that the wafer 100 is on the glass table 21, the touch panel 5 functions as a notification unit that notifies the operator that the wafer 100 is on the glass table 21.

[0078] As described above, in this embodiment, when it becomes difficult for the wafer holding pad 90 to hold the wafer 100 and continuous processing is temporarily stopped, the detection unit 71 detects the presence or absence of the wafer 100 on the glass table 21 using the amount of ultraviolet light measured by the light amount measurement unit 80. This makes it possible to clearly detect the presence or absence of the wafer on the glass table 21.

[0079] Therefore, for example, even if a wafer 100 that is difficult to hold by the wafer holding pad 90 is left on the glass table 21, continuous processing is resumed, a sheet S is placed on top of the wafer 100, and liquid resin is further supplied onto the sheet S, which prevents the wafer 100, the sheet S, and the liquid resin from being wasted.

[0080] Furthermore, in this embodiment, when the wafer 100 is left on the glass table 21, the operator is notified of this fact by the touch panel 5. This allows the operator to easily detect that the wafer 100 on the glass table 21 needs to be removed. Note that such notification to the operator by the touch panel 5 may be omitted.

[0081] In addition, in this embodiment, when the measurement value of the pressure sensor 303 does not fall below a predetermined threshold and the continuous processing of the wafer 100, i.e., the protective member forming process including the sheet holding process, liquid resin supply process, wafer holding process, expansion process, hardening process and transport process, is temporarily suspended, the control unit 7 and the detection unit 71 perform the wafer detection process. In this regard, the control unit 7 and the detection unit 71 can perform the wafer detection process at any time while the protective member forming process is stopped. That is, the control unit 7 may perform the wafer detection process at a predetermined timing set by the operator while the protective member forming process is stopped.

[0082] For example, the control unit 7 and the detection unit 71 may perform the wafer detection step when the measurement value of the pressure sensor 303 does not fall below the predetermined threshold and the continuous processing is temporarily stopped, as described above, or may perform the wafer detection step always or periodically before starting the protective member forming step for the wafer 100. That is, the control unit 7 and the detection unit 71 may use the light quantity measurement unit 80 to detect the presence or absence of the wafer 100 on the glass table 21 always or periodically before pulling out the sheet S from the roll unit 17 in the sheet holding step described above. With this configuration, if the wafer 100 remains on the glass table 21 for some reason, it is possible to prevent the sheet S from being placed on top of it. [Explanation of symbols]

[0083] 1: protective member forming device, 4: first conveying mechanism, 5: touch panel, 6: temporary placement mechanism, 7: control unit, 8: cutting device, 9: second transport mechanism, 10: second robot hand, 14: First robot hand, 16: Sheet supply mechanism, 17: Roll unit, 20: sheet holding mechanism, 21: glass table, 22: sheet placing surface, 24: table support base, 25: cylindrical portion, 26: bottom plate portion, 27: air outlet, 28: sheet suction port, 29: UV light source, 30: sheet transport mechanism, 31: support member, 32: sheet gripping portion, 33: moving member, 35: air bubble removal roller, 40: Liquid resin supply unit, 41: Liquid resin supply nozzle, 42: Dispenser, 50: wafer holding mechanism, 51: support structure, 52: holding table, 53: outer periphery connection portion, 54: Load detection unit, 60: Lifting mechanism, 61: Ball screw, 62: Motor, 63: Guide rail, 64: Lift plate, 65: Encoder, 71: Detection unit, 80: light quantity measuring unit, 81: arm, 82: support column, 83: rotation motor, 84: optical sensor, 90: wafer holding pad, 91: pad portion, 92: wafer holding surface, 93: outer periphery suction portion, 94: fluid passage, 95: suction path, 96: suction valve, 97: air flow path, 98: air valve, 99: movement mechanism, 100: wafer, 101: front surface, 102: back surface, 104: protective member, 105: liquid resin, 200: housing, 201: device base, 202: column, 203: support base, 204: table base, 205: cassette storage body, 206: storage space, 207: accommodation space, 208: cassette, 209: cassette, 271: air flow path, 272: fluid passage, 273: air valve, 281: suction passage, 283: suction valve, 301: air supply source, 302: suction source, 303: pressure sensor, 821: rotating shaft, 921: recess, 922: ring packing, S: seat

Claims

1. a glass table for placing a sheet having an area larger than one surface of the wafer; a holding table that holds a wafer above the glass table; a liquid resin supply unit that supplies an ultraviolet curable liquid resin to the sheet placed on the glass table; a lifting mechanism that moves the glass table and the holding table relatively close to each other to spread the liquid resin over the entire surface of one side of the wafer; a UV light source that irradiates the liquid resin with ultraviolet light from the glass table side to form a protective member made of the cured liquid resin on one surface of the wafer; a wafer transfer mechanism that transfers the wafer on which the protective member is formed from the glass table, a light quantity measuring unit that measures the quantity of ultraviolet light that is irradiated from the UV light source and passes through the glass table; a detection unit that detects that a wafer is present on the glass table when the amount of light measured by the light amount measurement unit is equal to or less than a predetermined threshold; The protective member forming device further comprises:

2. The apparatus further includes a notification unit that notifies an operator that a wafer is present on the glass table when the detection unit detects that a wafer is present on the glass table. The protective member forming apparatus according to claim 1 .

3. A method for forming a protective member using the protective member forming apparatus according to claim 1, a protective member forming step of forming a protective member on one surface of the wafer; a wafer detection step, which is carried out while the protective member forming step is stopped, of measuring an amount of ultraviolet light irradiated from the UV light source and transmitted through the glass table by the light amount measuring unit, and detecting the presence or absence of a wafer on the glass table by the detection unit based on the measured light amount, When the detection unit detects that a wafer is present on the glass table in the wafer detection step, a notification step is carried out in which a notification unit of the protective member forming apparatus notifies an operator that a wafer is present; the protective member forming step is carried out when the detection unit detects that the wafer is not present on the glass table in the wafer detection step. A method for forming a protective member.

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