Protective member forming device

Abstract

To adhere a sheet onto a lower surface of a glass table without generating an air pool in a protective member formation apparatus.SOLUTION: A protective member formation apparatus 1 includes a sheet holding table 4 which holds a sheet 92 above a wafer table 30 and can lift the sheet 92, and a conveyance table 5 for conveying the sheet 92 to the sheet holding table 4 moved in a horizontal direction, wherein the sheet holding table 4 includes a suction port 43 annually formed on the outer periphery of a circular glass plate 40, and a unit 44 for irradiating a resin with ultraviolet rays, the conveyance table 5 includes a dome formation mechanism 51, when the sheet 92 is held by the sheet holding table 4, the center of the sheet 92 is inflated in an upper direction by the dome formation mechanism 51, the sheet holding table 4 is lowered toward the sheet 92, the center of the sheet 92 is brought into contact with the lower surface of the glass plate 40 prior to the outer peripheral part, and when the area of the part contacting the lower surface of the glass plate 40 of the sheet 92 accompanying lowering of the sheet holding table 4 is expanded to the suction port 43, the sheet 92 is sucked and held by the sheet holding table 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a protective member forming apparatus that forms a protective member by spreading and curing a liquid resin supplied onto the upper surface of a disk-shaped wafer. [Background technology]

[0002] For example, as disclosed in Patent Document 1 or Patent Document 2, a predetermined amount of ultraviolet-curable liquid resin is supplied to the top surface of a wafer with bumps. Then, a sheet holding table holds the sheet, and the sheet presses the liquid resin from above to spread it over the top surface of the wafer. The spread liquid resin is irradiated with ultraviolet light through the sheet to harden it, forming a protective member that covers the bumps, absorbs the bump irregularities, and protects the top surface of the wafer.

[0003] After the protective member is formed, the wafer is held by suction on a chuck table of a grinding device via the protective member, and the surface of the wafer opposite to the surface on which the bumps are arranged is ground with a grinding wheel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-027239 [Patent Document 2] Japanese Patent Application Publication No. 2019-186355 Summary of the Invention [Problem to be solved by the invention]

[0005] When forming the protective member as described above, a sheet is transported to a sheet holding table by placing the sheet on the table, moving the table horizontally to directly below the table, and then lowering the table to suck and hold the sheet placed on the table.

[0006] The sheet holding table includes a glass table having a circular underside that is the same shape as the wafer, a suction port formed in a ring shape on the outside of the glass table to suction and hold the sheet, and an ultraviolet irradiation unit located inside.

[0007] The sheet holding table sucks the sheet with a ring-shaped suction port, forcing the upper surface of the sheet into tight contact with the underside of the glass table. However, air pockets can form between the underside of the glass table and the upper surface of the sheet. These air pockets do not disappear when the liquid resin is pressed and spread, resulting in a thin area where the air pockets remain, making it difficult to form a uniform thickness of the protective member.

[0008] To remove this air from the air pockets, the sheet is textured with small indentations. However, it takes a long time to remove the air through the textured surface of the sheet and through the annular suction ports on the outer periphery, which is not efficient. Therefore, in the protection member forming device, there is a problem in that when the sheet holding table sucks and holds the sheet, it is necessary to prevent air pockets from forming and to make the upper surface of the sheet adhere closely to the lower surface of the glass table. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a protective member forming apparatus for forming a protective member by spreading and curing a liquid resin supplied to an upper surface of a disk-shaped wafer, the protective member forming apparatus comprising: a wafer holding table that holds the lower surface of the wafer with a holding surface; a resin nozzle for supplying an ultraviolet-curable liquid resin onto the upper surface of the wafer held on the wafer holding table;The apparatus comprises a sheet holding table disposed above the wafer holding table for suction-holding a sheet having an area larger than that of the wafer, a vertical movement mechanism for moving the sheet holding table in a direction perpendicular to the holding surface, a transport table for transporting the sheet to the sheet holding table, and a horizontal movement mechanism for moving the transport table in a horizontal direction, wherein the sheet holding table comprises a glass plate facing the upper surface of the wafer held by the wafer holding table and having a lower surface with the same shape as the upper surface of the wafer, a frame for exposing the lower surface of the glass plate and supporting the glass plate, a sheet suction port formed in an annular shape along the outer periphery of the glass plate and communicating with a suction source, and an ultraviolet irradiation unit for irradiating ultraviolet light onto the liquid resin through the glass plate. the conveying table is provided with a dome forming mechanism that inflates the center of the held sheet upward, and when the sheet is to be suction-held on the sheet holding table, the dome forming mechanism of the conveying table is used to inflate the center of the sheet upward, and the sheet holding table is lowered toward the sheet using the vertical movement mechanism, thereby bringing the center portion of the sheet into contact with the underside of the glass plate before the outer periphery, and when the area of ​​the portion of the sheet that is in contact with the underside of the glass plate expands to the sheet suction opening as the sheet holding table is lowered, a control unit is provided that performs control to suction-hold the sheet on the sheet holding table and bring the sheet into close contact with the underside of the glass plate. Furthermore, the control unit controls the process of lowering the glass plate with the sheet tightly attached to its underside, spreading the liquid resin between the wafer and the sheet, and irradiating the spread liquid resin with ultraviolet light to harden it, thereby forming a protective member made of the hardened liquid resin and the sheet. This is a protective member forming device. In the protective member forming device of the present invention, the dome forming mechanism preferably comprises an elastic member disposed in the center of the upper surface of the transport frame of the transport table, the elastic member having a small shape similar to the upper surface of the wafer and projecting from the upper surface of the transport frame, and the sheet is placed on the elastic member projecting from the upper surface of the transport frame, and the weight of the sheet causes the outer peripheral portion of the sheet to sag, thereby inflating the central portion of the sheet placed on the elastic member. In the protective member forming device of the present invention, the dome forming mechanism preferably includes an annular suction port formed on the upper surface of the conveying table and having an inner diameter larger than the outer diameter of the glass plate, and an air outlet formed on the upper surface of the conveying table in an area more inward than the annular suction port and for spraying air, and air is sprayed from the air outlet onto the sheet held by suction by the annular suction port to inflate the central portion of the sheet. Furthermore, the present invention provides A method for forming a protective member for protecting the entire surface of one side of a wafer, the method comprising: a wafer holding step of holding the lower surface of the wafer on a wafer holding table; a sheet holding step of holding the upper surface of a sheet on a sheet holding table facing the wafer holding table; a liquid resin supply step of supplying an ultraviolet curable liquid resin to the upper surface of the wafer held on the wafer holding table; a liquid resin expansion step of lowering the sheet holding table toward the wafer and expanding the liquid resin between the wafer and the sheet; and irradiating the liquid resin expanded in the liquid resin expansion step with ultraviolet light. and a protective member forming process in which the liquid resin is irradiated to harden the resin, bonding the wafer and the sheet with the hardened resin, and forming a protective member from the resin and the sheet. The sheet holding process includes a dome shape forming process in which the center of the sheet held by a conveying table that conveys the sheet below the sheet holding table is inflated to form a dome shape, a sheet positioning process in which the conveying table is moved below the sheet holding table, and a lowering process in which the sheet holding table is lowered onto the sheet held on the conveying table with the inflated center. [Effects of the Invention]

[0010] In the protective member forming device of the present invention, the conveying table is equipped with a dome forming mechanism that inflates the center of the held sheet upward, and when the sheet is suction-held on the sheet holding table under the control of the control unit, the dome forming mechanism of the conveying table inflates the center of the sheet upward, and the sheet holding table is lowered toward the sheet using a vertical movement mechanism, so that the central part of the sheet contacts the underside of the glass plate before the outer peripheral part, and when the area of ​​the part of the sheet that is in contact with the underside of the glass plate expands as the sheet holding table lowers to the sheet suction port, the sheet is suction-held on the sheet holding table so that the sheet is tightly adhered to the underside of the glass plate without creating air pockets, making it possible to form a uniform protective member on the wafer. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an overall perspective view showing an example of a protective member forming device. [Figure 2] 2 is an enlarged perspective view illustrating a conveying table including a sheet roll, a sheet arrangement mechanism, a horizontal movement mechanism, and a dome forming mechanism according to the first embodiment. FIG. [Figure 3] FIG. 2 is a cross-sectional view illustrating a conveying table, a wafer holding table, and a sheet holding table. [Figure 4] 10 is a cross-sectional view illustrating a state in which the central portion of the sheet is brought into contact with the underside of the glass plate before the peripheral portion in order to hold the sheet on the conveying table on the sheet holding table. FIG. [Figure 5] This is a cross-sectional view illustrating the state in which the sheet is sucked and held by the sheet holding table, with the area of ​​the portion of the sheet that is in contact with the underside of the glass plate expanding to the sheet suction port as the sheet holding table descends, causing the sheet to be tightly attached to the underside of the glass plate. [Figure 6] 10 is a cross-sectional view illustrating a state in which liquid resin is being supplied to the upper surface of a wafer held by suction on a wafer holding table. FIG. [Figure 7] 10 is a cross-sectional view illustrating a state in which ultraviolet rays are irradiated onto a liquid resin supplied to the upper surface of a wafer from an ultraviolet irradiation unit through a glass plate. FIG. [Figure 8] 10 is a cross-sectional view illustrating a state in which the sheet holding table is separated from the sheet that has become a protection member. FIG. [Figure 9] FIG. 10 is a cross-sectional view illustrating a conveyance table equipped with a dome forming mechanism according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view illustrating a state in which the central portion of the sheet is brought into contact with the underside of the glass plate before the peripheral portion in order to hold the sheet on the conveying table equipped with the dome forming mechanism of embodiment 2 on the sheet holding table. [Figure 11] This is a cross-sectional view illustrating the state in which the sheet is sucked and held by the sheet holding table, with the area of ​​the portion of the sheet that is in contact with the underside of the glass plate expanding to the sheet suction port as the sheet holding table descends, causing the sheet to be tightly attached to the underside of the glass plate. DETAILED DESCRIPTION OF THE INVENTION

[0012] The protective member forming apparatus 1, which forms a protective member by spreading and hardening a liquid resin supplied to the upper surface 900 of the disk-shaped wafer 90 shown in Figure 1, comprises a housing 100 which forms a processing chamber, an apparatus base 101 arranged within the housing 100, a column 102 standing on the apparatus base 101, a support base 103 arranged adjacent to the side of the apparatus base 101, and a cassette storage body 104 connected to the rear side (+Y direction side) of the housing 100 and having a wafer storage space 105.

[0013] 1 is, for example, a silicon wafer, and has devices 902 such as ICs and LSIs formed on its upper surface 900 in a plurality of grid-like regions defined by a plurality of planned division lines 901. A plurality of bumps (protruding electrodes) 903 are provided on the surface of each of the devices 902. The bumps 903, made of copper or the like, have a height of, for example, about several tens of μm. The wafer 90 may be made of gallium arsenide, sapphire, gallium nitride, ceramics, resin, silicon carbide, or the like in addition to silicon, or may be an as-sliced ​​wafer or the like on which no devices or bumps are formed.

[0014] 1, there are arranged a temporary placement table 111 on which the wafer 90 is placed before the protective member is formed, and a sheet cutting stage 112 located below the temporary placement table 111. The sheet cutting stage 112 is a stage on which the wafer 90 is placed after the protective member has been formed.

[0015] Above the temporary placement table 111, there is disposed a wafer detection unit 113 which is made up of a camera or the like and which detects the center position etc. of the wafer 90 which has been placed on the temporary placement table 111 and before the protective member is formed, using a captured image. Also, above the sheet cutting stage 112, there is disposed a cutting mechanism 114 which uses a rotating cutter to cut the sheet 92 which constitutes the protective member for the wafer 90 placed / held by suction on the sheet cutting stage 112 into a circle along the outer periphery of the wafer 90.

[0016] In the wafer storage space 105 shown in FIG. 1, a cassette 106 capable of storing a plurality of wafers 90 arranged vertically like a shelf is arranged. A first robot 115, such as an articulated robot, is disposed between the cassette accommodating body 104 and the temporary placement table 111 and sheet cutting stage 112, and the first robot 115 is capable of reciprocating in the X-axis direction by an X-axis movement mechanism 116, such as a ball screw mechanism. For example, the first robot 115, which is equipped with a robot hand that is U-shaped in plan view, can carry out the wafer 90 from the cassette 106 before the protective member is formed and carry it into the temporary placement table 111, and can also carry out the wafer 90 from the sheet cutting stage 112 after the protective member has been formed and the sheet 92 has been cut into a circle and carry it into an empty shelf in the cassette 106.

[0017] The wafer 90, whose center position and the like have been detected by the wafer detection unit 113 on the temporary placement table 111, is held and transported by a second robot 117, which is an articulated robot or the like shown in Fig. 1. The second robot 117 has a robot hand that can hold the wafer 90 and rotate horizontally, and is capable of reciprocating in the Y-axis direction by a Y-axis movement mechanism 118, such as a ball screw mechanism. The second robot 117 can then carry out the wafer 90 from the temporary placement table 111 and place it on the wafer holding table 30 shown in Fig. 1.

[0018] In this embodiment, the wafer holding table 30 shown in Figures 1 to 3 is a so-called pin chuck that does not easily allow debris such as processing chips to accumulate on the holding surface 302, but is not limited to this and may be a porous chuck having a holding surface made of a porous material, etc. 3 includes, for example, a bottom plate 303 that is rectangular in plan view, and an outer peripheral annular wall 300 stands integrally in the +Z direction from the outer peripheral region of the upper surface of the bottom plate 303. A recessed space 301 (hereinafter referred to as suction space 301) that is circular in plan view and formed inside the outer peripheral annular wall 300 is a space in which a plurality of support pins 304 are disposed. A suction path 305 is provided inside the bottom plate 303, and the suction path is connected to a suction source 309 that is an ejector or a vacuum generating device.

[0019] A plurality of support pins 304 are erected at equal intervals on the upper surface of the bottom plate 303. In the example shown in Fig. 3, each support pin 304 has a cylindrical outer shape, but it may also have a truncated cone or pyramid outer shape. The upper end surfaces of the plurality of support pins 304 form a holding surface 302 shown in Figs. 1 and 2, which has a circular outer shape as a whole. The lower surface 904 of the wafer 90 is suction-held by this holding surface 302.

[0020] As shown in Figure 1, the protective member forming apparatus 1 includes the wafer holding table 30, a sheet holding table 4 that is positioned above the wafer holding table 30 and that suction-holds a sheet 92 (the sheet 92 after being cut into a rectangular shape) that has an area larger than the wafer 90, a vertical movement mechanism 42 that moves the sheet holding table 4 perpendicular to the holding surface 302 (the vertical Z-axis direction), a conveying table 5 that conveys the sheet 92 to the sheet holding table 4, and a horizontal movement mechanism 53 that moves the conveying table horizontally.

[0021] A sheet positioning mechanism 8 is disposed on the device base 101, which is capable of pulling out a strip-shaped sheet 92, positioning it on the conveying table 5, and cutting the sheet 92 into a rectangle. The sheet positioning mechanism 8 shown in Fig. 2 at least includes, for example, a sheet supply unit 80 including a rotary shaft, a motor, and a plurality of rotary rollers, a sheet gripping unit 81 that grips the outer periphery (the outer periphery on the +Y direction side) of the strip-shaped sheet 92 fed out from the sheet supply unit 80, a gripping unit moving unit 84 that moves the sheet 92 gripped by the sheet gripping unit 81 so as to pull it out in the horizontal direction (+Y direction), and a sheet cutting unit 87 that cuts the rear end side of the strip-shaped sheet 92 fed out by the sheet supply unit 80 to form a rectangular sheet 92.

[0022] 2, which is configured with a plurality of rollers, a feed motor, etc., can feed a sheet 92 of a desired length in the +Y direction from a sheet roll 920 formed by winding a sheet 92 made of a predetermined resin into a roll. The fed strip-shaped sheet 92 moves toward the conveying table 5 while a predetermined tension is applied by a tension roller, a sandwiching parallel plate, etc.

[0023] 2, above the center of the top surface of the device base 101 is a receiving position P1 where the conveying table 5 is positioned when cutting the sheet 92 sent out in the +Y direction from the sheet supply unit 80. Adjacent to the receiving position P1 on the -Y side of the conveying table 5, a plurality of sheet suction holes 870 are formed, for example, in two rows at equal intervals in the X-axis direction, over a length approximately equal to the width of the sheet 92 in the X-axis direction. The sheet suction holes 870 are connected to a suction source such as a vacuum generator (not shown). The two rows of sheet suction holes 870 may be formed as two slits extending in the X-axis direction.

[0024] 2 is disposed, for example, near the front of the sheet supply unit 80. The sheet cutting unit 87 includes a cutter clearance groove 873 that is formed between two rows of sheet suction holes 870 in the device base 101 and that crosses the width direction of the sheet 92, and a cutter 871 that is disposed above the cutter clearance groove 873, is movable up and down, and moves within the cutter clearance groove 873 along the extension direction of the cutter clearance groove 873 (the X-axis direction).

[0025] 2 is, for example, an electric slider, and is disposed in an area on the +X direction side above the device base 101, and includes a guide rail 840 extending in the Y axis direction, and a slide bar 841 that can move back and forth in the Y axis direction while being guided by the guide rail 840. The slide bar 841 extends with its tip pointing in the −X direction, and the sheet gripper 81 is attached to the side surface on the −Y direction side.

[0026] The sheet gripping portion 81 is a gripping clamp that extends in the X-axis direction (width direction of the sheet 92) with a length approximately equal to the width of the sheet 92, and clamps the outer periphery of the tip side of the sheet 92 to be gripped between a pair of gripping plates that can approach and move away from each other in the Z-axis direction.

[0027] 1 and 2, horizontal movement mechanism 53, which moves conveying table 5 horizontally in the Y-axis direction, includes, for example, an electric slider (not shown) disposed within support base 103. A movable elongated hole 531, which allows a movable arm 530 connected to the electric slider to move in the Y-axis direction, is formed through the top plate of support base 103 shown in Fig. 1 and extends a predetermined length in the Y-axis direction. Movable arm 530, whose lower end is connected to the electric slider (not shown), passes vertically through movable elongated hole 531, is exposed to the outside from support base 103, and then extends a predetermined length in the +Y direction, having a generally L-shaped outer shape in side view.

[0028] 1 and 3, two support members 533 extend with their tips facing the +X direction on the side surface on the +X direction side of the movable arm 530. The transport table 5 is connected to the tips of the two support members 533.

[0029] As shown in Figures 1 and 2, the conveying table 5, which can move back and forth in the Y-axis direction, is arranged at a position below the sheet gripping portion 81, which can also move back and forth in the Y-axis direction, so that the sheet gripping portion 81, which is out of alignment with the flow path, will not collide with the conveying table 5.

[0030] 1 to 3 includes a dome forming mechanism 51 that bulges upward at the center of a held sheet 92 (sheet 92 after being cut into a rectangle). Hereinafter, the dome forming mechanism 51 will be referred to as the dome forming mechanism 51 of the first embodiment.

[0031] As shown in FIG. 3, the dome forming mechanism 51 includes, for example, a circular recess 510 formed in the center of the upper surface 502 of the transport frame 50 of the transport table 5 with a diameter smaller than that of the wafer 90, and in this embodiment, an elastic member 511 accommodated in the circular recess 510 and having an upper portion protruding from the upper surface 502 of the transport frame 50.

[0032] The conveying frame 50 of the conveying table 5 is formed, for example, in a roughly square shape when viewed from above, and the portion of the sheet 92 cut into a rectangle by the sheet cutting section 87 shown in Figure 2 that protrudes from the elastic member 511 is placed on the flat area other than the circular recess 510 formed in the center of the upper surface 502. 3, the circular plate-shaped elastic member 511 is sized to fit into the circular recess 510 having a diameter smaller than that of the wafer 90, and is, for example, a sponge, and protrudes upward by a predetermined length from the upper surface 502 of the transport frame 50. The elastic member 511 may be disposed in the center of the upper surface 502 of the transport frame 50 of the transport table 5, and may protrude from the upper surface 502 of the transport frame 50 in a shape similar to but smaller than the upper surface 900 of the wafer 90. Therefore, if the wafer 90 has, for example, an orientation flat indicating crystal orientation formed on its outer periphery by cutting out a portion of the outer periphery, and the lower surface 400 of the glass plate 40 has a corresponding shape in which a portion of the circular outer periphery is cut out flat, the elastic member 511 will also have a corresponding shape in which a portion of the circular outer periphery is cut out flat.

[0033] The vertical movement mechanism 42 arranged on the front side of the -Y direction of the column 102 shown in Figure 1 is composed of a ball screw 420 having an axis in the Z axis direction (vertical direction), a pair of guide rails 421 arranged parallel to the ball screw 420, a motor 422 connected to the ball screw 420 and rotating the ball screw 420, and an elevator holder 423 whose internal nut is threaded onto the ball screw 420 and whose side is in sliding contact with the guide rail 421, and as the motor 422 rotates the ball screw 420, the elevator holder 423 is guided by the guide rail 421 and rises and falls together with the sheet holding table 4 that it supports.

[0034] 1 and 3 includes a glass plate 40 that faces the upper surface 900 of the wafer 90 held by the wafer holding table 30 and has a circular lower surface 400 that is the same shape as the upper surface 900 of the wafer 90, for example, and a frame 41 that exposes the lower surface 400 of the glass plate 40 and supports the glass plate 40. Note that if an orientation flat, for example, is formed on the wafer 90, the shape of the glass plate 40 will also be such that a portion of the circular outer periphery is cut out to form a flat accordingly.

[0035] 3 includes, for example, an upper plate 410 that is circular in plan view, and an outer peripheral annular wall 411 hangs down integrally in the −Z direction from the outer peripheral region of the lower surface of the upper plate 410. A circular glass plate 40 is fitted into a space 412 that is circular in plan view and formed inside the outer peripheral annular wall 411, and is made of, for example, quartz glass, and its lower surface 400 is a flat surface that is flush with the lower end surface of the outer peripheral annular wall 411 of the frame 41.

[0036] The outer surface of the glass plate 40 is fixed to a frame 41, and a space 412 for accommodating an ultraviolet irradiation unit 44 is provided between the upper surface of the glass plate 40 and the upper plate 410. The ultraviolet irradiation unit 44, which irradiates the liquid resin with ultraviolet rays through the glass plate 40, is composed of, for example, a plurality of LED lights or the like that can irradiate ultraviolet rays of a predetermined wavelength downward.

[0037] The frame 41 has a plurality of sheet suction ports 43 formed at equal intervals in a ring shape along the outer periphery of the glass plate 40. The sheet suction port 43 may be a single annular suction groove. The sheet suction port 43 is connected to a suction source 49 such as a vacuum generator via a suction flow path inside the frame 41 and a suction pipe outside the frame 41.

[0038] 1, the protective member forming apparatus 1 is equipped with a resin nozzle 36 that supplies liquid resin to the upper surface 900 of a wafer 90 that is held by suction on a wafer holding table 30. The resin nozzle 36 is a swivel nozzle that can swivel above the wafer holding table 30 and has an inverted L-shape in side view with an ejection port directed toward the center of the holding surface 302 of the wafer holding table 30, and can be retracted from above the wafer holding table 30 to a retracted position.

[0039] 1, the protective member forming apparatus 1 includes a dispenser 361 that delivers a predetermined amount of liquid resin to the resin nozzle 36, and a connecting pipe 362 that connects the resin nozzle 36 and the dispenser 361. The dispenser 361 is also connected via a connecting pipe (not shown) to a resin tank 363 disposed within the apparatus base 101. The liquid resin that is supplied from the resin tank to the resin nozzle 36 by the dispenser 361 while adjusting the amount is an ultraviolet-curable resin that is cured by irradiation with ultraviolet light in this embodiment.

[0040] The protective member forming apparatus 1 includes a control unit 7 that controls the entire apparatus. The control unit 7 includes a CPU that performs calculations according to a control program, a storage medium such as a memory, and the like. The control unit 7 is electrically connected to a motor 422 (e.g., a servo motor 422) of the vertical movement mechanism 42 shown in FIG. 1 via, for example, a wired or wireless communication path. That is, an operation signal is supplied to the servo motor 422 from an output interface of the control unit 7, which also functions as a servo amplifier, and the rotation speed of the servo motor 422 detected by an encoder is output to an input interface of the control unit 7 as an encoder signal. The control unit 7 then feedback-controls the Z-axis feed speed of the sheet holding table 4 and the movement distance of the sheet holding table 4, which are controlled by the vertical movement mechanism 42, and also controls the sheet holding table 4 to be positioned at a desired height.

[0041] Using substantially the same technology as above, the control unit 7 can control the movement of the conveying table 5 in the Y-axis direction by the horizontal movement mechanism 53, which is an electric slider, and can also control the movement of the sheet gripper 81 in the Y-axis direction by the gripper movement unit 84, which is an electric slider. The control unit 7 can also control the rotation speed of the feed motor of the sheet supply unit 80, to control the feed operation of the sheet 92 by the sheet supply unit 80.

[0042] The operation of the protective member forming apparatus 1 shown in FIG. 1 when forming a protective member on the wafer 90 will be described below. First, the first robot 115 shown in Fig. 1 takes out one wafer 90 from the cassette 106 and transfers it onto the temporary placement table 111. When the wafer detection unit 113 detects the center position of the wafer 90 on the temporary placement table 111, the second robot 117 suction-holds the wafer 90, carries the wafer 90 out, and moves in the -Y direction to place the wafer 90 on the wafer holding table 30. The wafer holding table 30 then suction-holds the wafer 90 with the center of the wafer 90 and its own center approximately aligned. The top surface 900 of the wafer 90 is exposed upward, and the second robot 117 moves away from above the wafer 90.

[0043] In parallel with the transport of the wafer 90 to the wafer holding table 30, under the control of the control unit 7, the sheet supply unit 80 rotates the sheet roll 920, and the leading edge of the strip-shaped sheet 92 is fed horizontally in the +Y direction by a guide roller or the like. Also, under the control of the control unit 7, the sheet gripping unit 81 moves in the -Y direction by the gripping unit moving unit 84, and the sheet gripping unit 81 grips the leading edge of the strip-shaped sheet 92.

[0044] Next, as the sheet supply unit 80 feeds out the sheet 92, the sheet gripping unit 81 moves in the +Y direction, and the sheet gripping unit 81 gripping the sheet 92 is positioned at the receiving position P1 shown in Figures 1 and 2. Also, the sheet supply unit 80 temporarily stops feeding out the sheet 92.

[0045] In parallel with the sheet supply unit 80 feeding out the sheet 92, under the control of the control unit 7, the horizontal movement mechanism 53 positions the conveying table 5 at the receiving position P1, and the sheet 92 gripped by the sheet gripping unit 81 is positioned above the upper surface 502 of the conveying frame 50 of the conveying table 5 and the upper surface of the elastic member 511.

[0046] The strip-shaped sheet 92, pulled out horizontally in the +Y direction by the sheet gripping unit 81 by a predetermined length, is placed on the upper surface of the elastic member 511 so as to cover the entire surface. In addition, a suction force generated by a suction source (not shown) is transmitted to the sheet suction hole 870 shown in FIG. 2, and the rear end side of the sheet 92 is sucked and held by the sheet suction hole 870 across the cutter relief groove 873 in the Y-axis direction. At this stage, the cutter 871 of the sheet cutting unit 87 is in a standby state above the sheet 92.

[0047] Cutter 871 descends until the bottom end of its cutting edge is within cutter clearance groove 873. Cutter 871 then advances in the +X direction along the extension direction of cutter clearance groove 873, and cuts sheet 92. After cutter 871 cuts sheet 92 in the width direction, cutter 871 rises in the +Z direction and moves away from sheet 92, which has now become rectangular. Then, sheet gripping portion 81 releases its grip on sheet 92, and sheet 92 is placed on elastic member 511 protruding from upper surface 502 of conveying frame 50, as shown in FIG. 3. Outer periphery 921 of sheet 92 sags due to the weight of sheet 92, which has been cut into a rectangular shape, and central portion 922 of sheet 92 placed on elastic member 511 becomes inflated. That is, the dome forming mechanism 51 causes the central portion 922 of the sheet 92 placed and held on the conveyor table 5 to expand upward in a dome shape relative to the outer peripheral portion 921 .

[0048] 4, the conveying table 5 on which the sheet 92 is placed is further moved in the +Y direction and positioned directly below the sheet holding table 4. For example, the center of the sheet 92 on the conveying table 5 and the center of the lower surface 400 of the glass plate 40 on the sheet holding table 4 are brought into a state where they are substantially aligned.

[0049] Next, under the control of the control unit 7 (see Figure 1), the sheet holding table 4 is lowered by the vertical movement mechanism 42, and the central portion 922 of the sheet 92 placed on the upper surface of the elastic member 511 that protrudes a predetermined height above the upper surface 502 of the conveying frame body 50 of the conveying table 5 comes into contact with the flat lower surface 400 of the glass plate 40 before the peripheral portion 921. The vertical movement mechanism 42 has a function to recognize the height position of the sheet holding table 4 (for example, a function to control the rotation speed of the motor 422 by the control unit 7, or a function to read the graduations of a scale that extends in the Z-axis direction and indicates the height position of the sheet holding table 4 by a reading unit), and recognizes that the lower surface 400 of the glass plate 40 has come into contact with the central portion 922 of the sheet 92 at the height position of the sheet holding table 4. Alternatively, the conveying table 5 or the sheet holding table 4 may be provided with a load sensor that detects a vertical load, and it may be recognized that the lower surface 400 of the glass plate 40 has come into contact with the central portion 922 of the sheet 92 based on the value of the load sensor.

[0050] 5, as the sheet holding table 4 is lowered at a predetermined speed by the vertical movement mechanism 42, the elastic member 511, which is a sponge, is pressed and compressed, and the upper surface of the elastic member 511 and the upper surface 502 of the conveying frame 50 become flush with each other, so that the area of ​​the portion of the sheet 92 on the conveying table 5 that is in contact with the lower surface 400 of the glass plate 40 expands to the sheet suction port 43. In other words, the upper surface of the outer peripheral portion 921 of the sheet 92 becomes flush with the upper surface of the central portion 922, and the upper surface of the outer peripheral portion 921 as well as the upper surface of the central portion 922 come into contact with the sheet suction port 43. Since the vertical movement mechanism 42 recognizes the height position of the sheet holding table 4, it may recognize that the lower surface 400 of the glass plate 40 has contacted the central portion 922 of the sheet 92, and then further lower the sheet holding table 4 by the amount of protrusion of the elastic member 511 from the upper surface 502 of the transport frame 50, thereby recognizing that the upper surface of the outer peripheral portion 921 of the sheet 92 has contacted the sheet suction port 43 in addition to the upper surface of the central portion 922. Alternatively, the control unit 7 may recognize the height position of the upper surface 502 of the transport frame 50, and when the lower surface 400 of the glass plate 40 has lowered to a height position that is the height position of the upper surface 502 of the transport frame 50 plus the thickness of the used sheet 92, it may recognize that the upper surface of the outer peripheral portion 921 has contacted the sheet suction port 43 in addition to the upper surface of the central portion 922, and start transmitting the suction force generated by the suction source 49 (described later) to the sheet suction port 43.

[0051] After this state is reached, the suction source 49 is activated under the control of the control unit 7 (see Figure 1), and the suction force generated by the suction source 49 is transmitted to the sheet suction port 43, so that the upper surface of the outer peripheral portion 921 of the sheet 92 is sucked and held by the sheet suction port 43, and the upper surface of the sheet 92 is tightly adhered to the lower surface 400 of the glass plate 40 without creating any air pockets.

[0052] 6, the sheet holding table 4 that has suction-held the sheet 92 rises, and the sheet 92 is released from the transport table 5. Furthermore, the transport table 5 retreats in the -Y direction, retreating from between the sheet holding table 4 and the wafer holding table 30.

[0053] 6, the resin nozzle 36 pivots and is positioned to supply liquid resin to the center of the upper surface 900 of the wafer 90 held by suction on the wafer holding table 30. The dispenser 361 shown in FIG. 1 delivers a predetermined amount of liquid resin 369, the temperature of which is controlled at a reference temperature, to the resin nozzle 36, which then drips the liquid resin 369 toward the upper surface 900 of the wafer 90. When a predetermined amount of liquid resin 369 has accumulated in the central region of the upper surface 900, the supply of liquid resin 369 to the wafer 90 is stopped, and the pivoting resin nozzle 36 is retracted from above the wafer 90.

[0054] Next, under the control of the control unit 7, the sheet holding table 4 is lowered by the vertical movement mechanism 42 as shown in Fig. 7, and the lower surface of the sheet 92 held by suction on the sheet holding table 4 comes into contact with the liquid resin 369. When the sheet holding table 4 is further lowered, the liquid resin 369 pressed by the lower surface of the sheet 92 is spread in the radial direction of the wafer 90. As a result, a film of the liquid resin 369 is formed over the entire upper surface 900 of the wafer 90.

[0055] After the sheet 92 is pressed against the liquid resin 369 for a predetermined time, forming a film of the liquid resin 369 over the entire upper surface 900 of the wafer 90, the ultraviolet irradiation unit 44 shown in FIG. 7 irradiates the film of the liquid resin 369 with ultraviolet light that has passed through the glass plate 40. As a result, the film of the liquid resin 369 hardens, and a protective member 98 consisting of the rectangular sheet 92 and the hardened resin 369 is formed on the upper surface 900 of the wafer 90. In other words, since there is no air pocket between the lower surface 400 of the glass plate 40 and the sheet 92 and the lower surface 400 and the sheet 92 are in close contact with each other, a uniform protective member 98 can be formed on the wafer 90. The hardened resin 369 absorbs the irregularities corresponding to the bumps 903 on the wafer 90, and the upper surface of the sheet 92 becomes flat.

[0056] After the protective member 98 is formed as described above, the suction force generated by the suction source 49 shown in Fig. 8 is cut off from being transmitted to the sheet suction port 43. Furthermore, the sheet holding table 4, which has released the suction holding of the sheet 92, rises and moves away from the sheet 92.

[0057] Furthermore, the suction holding of the underside 904 of the wafer 90 by the wafer holding table 30 is released, and the wafer 90 on which the protective member 98 shown in FIG. 8 has been formed is transported to the sheet cutting stage 112 by the second robot 117 shown in FIG. 1, and the second robot 117 places the wafer 90 on the sheet cutting stage 112 with the protective member 98 facing downward, and the protective member 98 is held by suction by the sheet cutting stage 112. Then, the cutting mechanism 114 cuts the rectangular excess sheet 92 into a circle along the outer periphery of the wafer 90. Thereafter, the first robot 115 stores the wafer 90 in an empty shelf of the cassette 106.

[0058] For example, after the cassette 106 is filled with wafers 90 on which the protective member 98 is formed, the cassette 106 is transported to a grinding device (not shown). Thereafter, the wafers 90 are suction-held on a chuck table of the grinding device (not shown) with the lower surfaces 904, on which the protective member 98 is not formed, facing upward, and a rotating grinding wheel is lowered from above the wafers 90 to grind the wafers 90 while the grinding stone is brought into contact with the lower surfaces 904 facing upward, thereby thinning the wafers 90 to a predetermined thickness. Thereafter, the protective member 98 is peeled off from the wafers 90 by a tape peeling device.

[0059] The protective member forming apparatus 1 may be provided with a conveying table 54 equipped with a dome forming mechanism 55 of embodiment 2 shown in FIG. 9, which will be described below, instead of the conveying table 5 equipped with the dome forming mechanism 51 of embodiment 1 shown in FIG. 3. 1 and 2, and is formed in the shape of a substantially square plate in a plan view, with its upper surface 540 serving as a flat suction surface. The dome forming mechanism 55 shown in Fig. 9 includes an annular suction port 550 formed in the upper surface 540 of the conveying table 5 and having an inner diameter larger than the outer diameter of the circular glass plate 40, and an air outlet 552 formed in an area on the upper surface 540 of the conveying table 5 inside the annular suction port 550 and for ejecting air.

[0060] The annular suction port 550 may be, for example, a plurality of equally spaced apart annular suction ports 550 so as to form an overall annular shape, or may be a single annular suction groove. The annular suction port 550 is connected to a suction source 59 such as a vacuum generator via a suction flow path 542 inside the conveyor table 54 and a suction pipe outside the conveyor table 54. If the wafer 90 has an orientation flat and the lower surface 400 of the glass plate 40 has a corresponding circular outer periphery cut out to form a flat, the shape of the annular suction port 550 may also be formed accordingly, so that the overall shape is annular with a linear portion of the annular shape.

[0061] The air outlet 552 is formed in the center of the upper surface 540 so as to penetrate, for example, the conveyor table 54 in the thickness direction (Z-axis direction), and is connected to an air source 58 constituted by a compressor or the like via an air supply pipe 581. For example, the air supply pipe 581 is provided with a solenoid valve 582 that can switch between a state in which the air supply pipe 581 is connected to the air source 58 and a state in which the air supply pipe 581 is open to the atmosphere. The solenoid valve 582 is electrically connected to the control unit 7 shown in FIG. 1.

[0062] The following describes a case where a sheet 92 is held by suction using a conveying table 54 equipped with a dome forming mechanism 55 of embodiment 2, and further, the sheet holding table 4 receives and holds by suction the sheet 92 held by the conveying table 54.

[0063] The suction holding of wafer 90 by wafer holding table 30 shown in Figures 1 and 2, the cutting into rectangular shapes of strip-shaped sheet 92 supplied by sheet supply unit 80 and positioned above conveying table 54 shown in Figure 9 by cutter 871 (see Figure 3), and the release of the grip of rectangularly cut sheet 92 on conveying table 54 by sheet gripping unit 81 are carried out in substantially the same manner as in the case of conveying table 5 equipped with dome forming mechanism 51 of embodiment 1 described above.

[0064] 2 releases its grip on the rectangularly cut sheet 92, whereby the sheet 92 is placed on the upper surface 540 of the conveying table 54 shown in FIG. 9 positioned below it, with their centers substantially aligned. Next, under the control of the control unit 7 shown in FIG. 1, the suction source 59 is activated, and the suction force generated by the suction source 59 is transmitted to the annular suction port 550, so that the lower surface of the outer peripheral portion 921 of the sheet 92 is sucked and held by the annular suction port 550.

[0065] 9 is energized under the control of the control unit 7, and the air supply pipe 581 is connected to the air source 58. Air 589 is supplied from the air source 58 to the air outlets 552 of the conveying table 54, and the air 589 ejected from the air outlets 552 causes the central portion 992 of the sheet 92 to expand upward. That is, the central portion 922 of the sheet 92, which is suction-held by the annular suction port 550 of the conveying table 5, is expanded upward into a dome shape by the dome forming mechanism 55. The amount of air 589 supplied from the air source 58 to the conveying table 54 is adjusted so that the annular suction port 550 does not release the suction hold of the underside of the outer peripheral portion 921 of the sheet 92.

[0066] Next, under the control of the control unit 7, the sheet holding table 4 is lowered by the vertical movement mechanism 42 shown in Figure 10, and the dome-shaped central portion 922 of the sheet 92 held by suction on the conveying table 54 comes into contact with the flat underside 400 of the glass plate 40 before the peripheral portion 921.

[0067] When the lower surface 400 of the glass plate 40 comes into contact with the central portion 922 of the sheet 92, the solenoid valve 582 opens the air supply pipe 581 to the atmosphere under the control of the control unit 7, as shown in Fig. 10. Furthermore, as shown in Fig. 10, the sheet holding table 4 is lowered at a predetermined speed by the vertical movement mechanism 42, which pushes the dome-shaped central portion 922 of the sheet 92 downward, and air 589 that was between the upper surface 540 of the conveying table 54 and the sheet 92 is released into the atmosphere through the air supply pipe 581. The conveying table 54 may be provided with an air exhaust port for releasing air 589 between the upper surface 540 of the conveying table 54 and the sheet 92, and a regulator with a relief valve that is disposed at the air exhaust port and enables the release of air while maintaining the pressure of the air 589 between the upper surface 540 of the conveying table 54 and the sheet 92 at a predetermined value, i.e., to prevent the dome-shaped bulge of the sheet 92 from suddenly deflating. In addition, the vertical movement mechanism 42 has a function of recognizing the height position of the sheet holding table 4, and recognizes that the lower surface 400 of the glass plate 40 has contacted the central portion 922 of the sheet 92 at the height position of the sheet holding table 4. Furthermore, the conveying table 5 or the sheet holding table 4 may be provided with a load sensor that detects a vertical load, and the contact of the lower surface 400 of the glass plate 40 with the central portion 922 of the sheet 92 may be recognized based on the value of the load sensor. Furthermore, it may be possible to recognize that the lower surface 400 of the glass plate 40 has come into contact with the central portion 922 of the sheet 92 based on the value of a regulator with a relief valve.

[0068] 11 , the area of ​​the portion of the sheet 92 on the conveying table 54 that is in contact with the lower surface 400 of the glass plate 40 expands to the sheet suction port 43. That is, the upper surface of the outer peripheral portion 921 of the sheet 92 becomes flush with the upper surface of the central portion 922, and the upper surface of the outer peripheral portion 921, in addition to the upper surface of the central portion 922, comes into contact with the sheet suction port 43. Note that, for example, the control unit 7 may recognize the height position of the upper surface 540 of the conveying table 54, and when the lower surface 400 of the glass plate 40 descends to a height position obtained by adding the thickness of the sheet 92 used to the height position of the upper surface 540 of the conveying table 54, it may recognize that the upper surface of the outer peripheral portion 921, in addition to the upper surface of the central portion 922, has come into contact with the sheet suction port 43, and may start transmitting the suction force generated by the suction source 49 to the sheet suction port 43.

[0069] When this state is reached, the suction source 49 is activated under the control of the control unit 7 shown in Figure 1, and the suction force generated by the suction source 49 is transmitted to the sheet suction port 43, so that the upper surface of the outer peripheral portion 921 of the sheet 92 is sucked and held by the sheet suction port 43, and the sheet 92 is tightly adhered to the lower surface 400 of the glass plate 40 without creating any air pockets. The subsequent steps are carried out in substantially the same manner as in the case of the conveying table 5 equipped with the dome forming mechanism 51 of the first embodiment described above, and since the underside 400 and the sheet 92 are in close contact with each other, it is possible to form a uniform protective member 98 (see Figure 8) on the wafer 90.

[0070] The protective member forming apparatus 1 according to the present invention is not limited to the above embodiment, and may be embodied in various different forms within the scope of its technical concept. Furthermore, the shapes of the components of the protective member forming apparatus 1 and the process for forming the protective member 98 shown in the accompanying drawings are not limited to these, and may be modified as appropriate within the scope of the effects of the present invention. [Explanation of symbols]

[0071] 1: Protective member forming device 100: Housing 101: Device base 102: Column 103: Support base 104: Cassette storage body 105: Wafer storage space 106: Cassette 111: Temporary placement table 112: Sheet cutting stage 113: Wafer detection unit 114: Cutting mechanism 115: First robot 116: X-axis movement mechanism 117: Second robot 118: Y-axis movement mechanism 30: Wafer holding table 300: Outer peripheral annular wall 301: Concave space 302: Holding surface 303: Bottom plate 304: Support pin 305: Suction path 309: Suction source 36: Resin nozzle 361: Dispenser 362: Connecting pipe 363: Resin tank 4: Sheet holding table 40: Glass plate 400: Underside of glass plate 41: Frame body 410: Upper plate 411: Outer peripheral annular wall 412: Space inside the frame body 42: Vertical movement mechanism 420: Ball screw 422: Motor 423: Lifting holder 43: Sheet suction port 44: Ultraviolet irradiation unit 49: Suction source 5: Transport table 50: Transport frame 502: Upper surface of transport frame 51: Dome forming mechanism of embodiment 1 510: Circular recess 511: Elastic member 53: Horizontal movement mechanism 530: Movable arm 531: Movable elongated hole 533: Support member 54: Conveyor table equipped with the dome forming mechanism of the second embodiment 540: Upper surface of the conveyor table 55: Dome forming mechanism of embodiment 2 550: Annular suction port 552: Air outlet 58: Air source 581: Air supply pipe 582: Solenoid valve 59: Suction source 7: Control unit 8: Sheet placement mechanism 80: Sheet supply unit 81: Sheet gripping unit 84: Grip moving part 840: Guide rail 841: Slide bar 87: Sheet cutting section 870: Sheet suction hole 871: Cutter 873: Relief groove for cutter 90: Wafer 900: Upper surface of wafer 901: Dividing line 902: Device 903: Bump 904: Underside of wafer 92: Sheet 920: Sheet roll

Claims

1. A protective member forming apparatus that forms a protective member by spreading and curing a liquid resin supplied to an upper surface of a disk-shaped wafer, a wafer holding table that holds the underside of a wafer on a holding surface; a resin nozzle that supplies ultraviolet-curable liquid resin to the upper surface of the wafer held on the wafer holding table; a sheet holding table that is disposed above the wafer holding table and that suction-holds a sheet having an area larger than the wafer; a vertical movement mechanism that moves the sheet holding table in a direction perpendicular to the holding surface; a transport table that transports the sheet to the sheet holding table; and a horizontal movement mechanism that moves the transport table in a horizontal direction; the sheet holding table includes a glass plate facing the upper surface of the wafer held by the wafer holding table and having a lower surface with the same shape as the upper surface of the wafer, a frame that exposes the lower surface of the glass plate and supports the glass plate, a sheet suction port that is formed in an annular shape along the outer periphery of the glass plate and communicates with a suction source, and an ultraviolet irradiation unit that irradiates the liquid resin with ultraviolet rays through the glass plate, the conveying table is provided with a dome forming mechanism that inflates the center of the held sheet upward; a control unit that controls, when the sheet is suction-held on the sheet holding table, the dome forming mechanism of the conveying table is used to inflate the center of the sheet upward, and the sheet holding table is lowered toward the sheet using the vertical movement mechanism, so that the center portion of the sheet contacts the underside of the glass plate before the peripheral portion does, and when the area of ​​the portion of the sheet that is in contact with the underside of the glass plate expands to the sheet suction opening as the sheet holding table is lowered, causes the sheet to be suction-held on the sheet holding table and the sheet to be in close contact with the underside of the glass plate; Furthermore, the control unit controls the process of lowering the glass plate with the sheet tightly attached to its underside, expanding the liquid resin between the wafer and the sheet, and irradiating the expanded liquid resin with ultraviolet light to harden it, thereby forming a protective member made of the hardened liquid resin and the sheet.

2. the dome forming mechanism includes an elastic member disposed at the center of an upper surface of a transport frame of the transport table, the elastic member having a small shape similar to the upper surface of the wafer and projecting from the upper surface of the transport frame, The protective member forming device according to claim 1, wherein the sheet is placed on the elastic member that protrudes from the upper surface of the conveying frame, and the weight of the sheet causes the outer peripheral portion of the sheet to sag, thereby expanding the central portion of the sheet placed on the elastic member.

3. 2. The protective member forming device of claim 1, wherein the dome forming mechanism comprises an annular suction port formed on the upper surface of the conveying table and having an inner diameter larger than the outer diameter of the glass sheet, and an air outlet formed on the upper surface of the conveying table in an area more inward than the annular suction port for ejecting air, and wherein air is ejected from the air outlet onto the sheet held by suction by the annular suction port to inflate the central portion of the sheet.

4. A method for forming a protective member that protects the entire surface of one side of a wafer, comprising: a wafer holding step of holding the underside of the wafer on a wafer holding table; a sheet holding step of holding an upper surface of a sheet on a sheet holding table facing the wafer holding table; a liquid resin supplying step of supplying an ultraviolet curable liquid resin onto the upper surface of the wafer held on the wafer holding table; a liquid resin spreading step of lowering the sheet holding table toward the wafer to spread the liquid resin between the wafer and the sheet; a protective member forming step of irradiating the liquid resin expanded in the liquid resin expanding step with ultraviolet light to harden the liquid resin and bond the wafer and the sheet together to form a protective member made of the resin and the sheet; The sheet holding step includes: The method includes a dome shape forming step of inflating the center of the sheet held by a conveying table that conveys the sheet below the sheet holding table to form a dome shape, a sheet positioning step of moving the conveying table below the sheet holding table, and a lowering step of lowering the sheet holding table onto the sheet held on the conveying table and with the center inflated. A method for forming a protective member.

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