Protective member formation device

Abstract

To efficiently form a protective member.SOLUTION: A protective member formation device expands a liquid resin to the whole surface of one surface of a wafer, cures the liquid resin, and forms a protective member protecting the whole surface thereof. The protective member formation device includes: a glass table 16 holding a sheet S; a wafer holding part which is arranged so as to face the glass table 16, and holds the wafer; a liquid resin supply nozzle for supplying the liquid resin onto the sheet S held on the glass table 16 or the wafer held on the wafer holding part; a lifting mechanism for relatively lifting the glass table 16 and the wafer holding part; an ultraviolet irradiation unit 23 which is a curing unit for imparting external stimulation to the liquid resin, and curing the liquid resin; and a wettability formation unit 27 for irradiating the surface of the sheet S held on the glass table 16 with ultraviolet or plasma, and improving wettability of the surface of the sheet S.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] A protective member forming device is known that forms a protective member on the surface of a wafer. For example, as disclosed in Patent Documents 1 and 2, the protective member forming device supplies a predetermined amount of liquid resin onto a sheet, presses the wafer held in a holder against the liquid resin, spreads the liquid resin over the entire surface of one side of the wafer, and then hardens the resin. In this way, a protective member made of a sheet and resin that protects one side of the wafer is formed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-061333 [Patent Document 2] JP 2022-020286 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional protective member forming devices have a technical problem in that it takes time for the liquid resin to spread. To address this technical problem, for example, the pressure in the closed chamber into which the liquid resin is supplied can be reduced to promote the spreading of the liquid resin.

[0005] However, even if the pressure inside the closed chamber is reduced, the liquid resin in the central part of the wafer, which is away from the gas-liquid interface, is difficult to spread, so the effect is limited. Therefore, a technology that can further shorten the time required to form the protective member is desired.

[0006] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a technique for efficiently forming a protective member. [Means for solving the problem]

[0007] A protective member forming apparatus according to one embodiment of the present invention is a protective member forming apparatus that spreads and hardens liquid resin over the entire surface of one side of a wafer to form a protective member that protects the entire surface of one side of the wafer, and includes a sheet holding section that holds a sheet, a wafer holding section that is positioned opposite the sheet holding section and holds a wafer, a liquid resin supply nozzle that supplies liquid resin onto the sheet held by the sheet holding section or onto the wafer held by the wafer holding section, a lifting mechanism that raises and lowers the sheet holding section and the wafer holding section relative to one another, a hardening unit that applies an external stimulus to the liquid resin to harden the liquid resin, and a wettability forming unit that irradiates ultraviolet light or plasma onto the surface of the sheet held by the sheet holding section to improve the wettability of the surface of the sheet. Effect of the Invention

[0008] According to the present invention, a technique for efficiently forming a protective member can be provided. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic perspective view of a protective member forming apparatus according to an embodiment; [Diagram 2] 10A to 10C are explanatory diagrams illustrating an example of a sheet supplying step in forming a protective member. [Diagram 3] 10A to 10C are explanatory diagrams illustrating an example of a wettability forming step in forming a protective member. [Figure 4] 10A to 10C are explanatory views showing an example of a liquid resin supplying step in forming the protective member. [Diagram 5] 10A to 10C are explanatory views showing an example of a wafer holding step in forming a protective member. [Figure 6] 10A to 10C are explanatory diagrams showing an example of a spreading step in forming a protective member. [Figure 7] 5A to 5C are explanatory views showing an example of a curing step in forming the protective member. [Figure 8]10A to 10C are explanatory views showing another example of the wettability forming step in forming the protective member. [Figure 9] 10A to 10C are explanatory views showing another example of the liquid resin supplying step in forming the protective member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A protective member forming apparatus according to an embodiment will now be described with reference to the accompanying drawings, in which: Fig. 1 is a schematic perspective view of a protective member forming apparatus according to an embodiment;

[0011] The X-axis, Y-axis, and Z-axis directions shown in each drawing are perpendicular to each other. The X-axis and Y-axis directions are substantially horizontal, and the Z-axis direction is the up-down direction (vertical direction).

[0012] The protective member forming apparatus 1 shown in Figure 1 is an example of an apparatus that forms a protective member H (see Figure 7) that protects the entire surface of one side of a wafer W, by spreading and hardening liquid resin M (see Figure 4) between the wafer W and a sheet S, and comprising a hardened resin of liquid resin M (referred to as resin HM to distinguish it from the liquid resin M before hardening) and a sheet S.

[0013] The protective member forming apparatus 1 has a configuration that improves the wettability of the surface of the sheet S onto which the liquid resin M is dropped, so that the liquid resin M spreads in a short time over the entire surface of one side of the wafer W between the wafer W and the sheet S. The configuration of the protective member forming apparatus 1 will be described in detail below.

[0014] An example will be described in which liquid resin M is supplied onto the surface of sheet S to form protective member H, but liquid resin M only needs to be supplied between sheet S and wafer W, and liquid resin M may be supplied onto wafer W rather than onto sheet S. For example, liquid resin M may be supplied onto the surface of a sheet (wafer sheet WS) formed on the surface of wafer W as described below with reference to Figures 8 and 9, or liquid resin M may be supplied directly onto the surface of wafer W.

[0015] 1 shows an external housing 10 of the protective member forming apparatus 1 with a dashed line, and shows a see-through state of the components inside the external housing 10. Of the wafer W, the surface facing upward during processing in the protective member forming apparatus 1 is referred to as an upper surface Wa, and the surface facing downward is referred to as a lower surface Wb.

[0016] The wafer W is, for example, a disk-shaped as-sliced ​​wafer cut from a cylindrical ingot of silicon etc. The wafer W is not limited to an as-sliced ​​wafer before devices are formed, but may be a device wafer after devices are formed, or a wafer with bumps.

[0017] The protective member forming apparatus 1 includes a cassette housing section 11 on the +Y direction side of an outer housing 10. Inside the cassette housing section 11, a cassette C capable of housing a plurality of wafers W is placed.

[0018] A sheet cutting table 14 is provided at a position on the -Y direction side of the cassette housing unit 11. The sheet cutting table 14 is provided with a sheet cutter 141 that cuts a sheet S, which will be described later, attached to the wafer W along the outer shape of the wafer W.

[0019] A first transport mechanism 12 for loading and unloading wafers W into and from the cassette C is provided on the -X direction side of the sheet cutting table 14. The first transport mechanism 12 includes a robot hand 122 supported on a pedestal 121, and transports the wafers W between the cassette C accommodated in the cassette accommodation unit 11 and the temporary placement table 13 by moving the pedestal 121 in the X-axis direction and operating the robot hand 122. The first transport mechanism 12 also transports the wafers W between the sheet cutting table 14 and the cassette C accommodated in the cassette accommodation unit 11.

[0020] The protective member forming apparatus 1 includes a base 15 on the -Y direction side of the sheet cutting table 14. The base 15 is provided with a glass table 160 (sheet holding portion) made of a light-transmitting material such as quartz glass. The glass table 160 is formed in a disk shape. The upper surface of the glass table 160 is a flat placement surface 161 on which the sheet S is placed. Furthermore, a support table 162 is provided to support the glass table 160. The upper surface of this support table 162 is provided with four suction holes 163 that are connected to a suction source (not shown) and that suck the sheet S.

[0021] The protective member forming apparatus 1 includes a sheet conveying mechanism 17 that conveys and places the sheet S on the placement surface 161 of the glass table 160 and the upper surface of the support table 162. The sheet conveying mechanism 17 includes a sheet supply unit 171 that supports the rolled sheet S, an arm 172 that is movable in the Y-axis direction, and a clamp unit 173 attached to the side of the arm 172. In the sheet conveying mechanism 17, the rolled sheet S supported by the sheet supply unit 171 is held by the clamp unit 173, and the arm 172 is moved in the +Y direction to pull the sheet S, thereby placing the sheet S on the placement surface 161 of the glass table 160 and on the upper surface of the support table 162. Then, a suction source is operated to apply suction force to the four suction holes 163, and the support table 162 holds the sheet S.

[0022] The sheet S is made of a light-transmitting material. For example, a film made of polyethylene terephthalate or the like can be used as the sheet S. Note that a sheet S made of a material other than this may also be used.

[0023] A circular suction hole 164 connected to a suction source (not shown) is formed at the boundary between the outer periphery of the mounting surface 161 of the glass table 160 and the inner periphery of the support table 162. The sheet S placed on the mounting surface 161 is sucked and held by applying a suction force to the suction hole 164 by operating the suction source. The glass table 160 and the support table 162 constitute a broad glass table 16 that holds the sheet S, and function as a sheet holding section of the protective member forming apparatus 1.

[0024] A resin supply mechanism 18 is provided near the glass table 16, which supplies a predetermined amount of liquid resin M onto the sheet S held on the glass table 16. The resin supply mechanism 18 includes a dispenser 181 connected to a tank 184 provided in the base 15, a connection pipe 182 extending from the dispenser 181, and a resin supply nozzle 183 to which the connection pipe 182 is connected.

[0025] The resin supply nozzle 183 is a liquid resin supply nozzle provided at the lower part of the arm 172. The resin supply nozzle 183 can be set to a state where it is positioned between the glass table 16 and a wafer holding part 20 that holds a wafer W described later, and a state where it is retracted from there between, by the movement of the arm 172 in the Y-axis direction by the sheet conveying mechanism 17.

[0026] Liquid resin M stored in a tank 184 is sent by a dispenser 181 via a connection pipe 182, and the liquid resin M is supplied (dried) downward from a resin supply nozzle 183. The amount of liquid resin M supplied from the resin supply nozzle 183 can be adjusted by the dispenser 181.

[0027] The liquid resin M has a property of being cured by an external stimulus. In this embodiment, an ultraviolet-curable liquid resin M that is cured by irradiation with ultraviolet rays is used. However, the liquid resin M may be a thermosetting resin.

[0028] The protective member forming apparatus 1 includes a wafer holding unit 20 that holds a wafer W and is disposed above a glass table 16. The wafer holding unit 20 is supported by a column 19 that protrudes upward from the base 15 at a position on the +Y direction side of the glass table 16. The column 19 is provided with a lifting mechanism 21 that moves (lifts and lowers) the wafer holding unit 20 in the Z-axis direction to move it closer to and away from the glass table 16.

[0029] The lifting mechanism 21 includes a pair of guide rails 211 and a ball screw 212 extending in the Z-axis direction, and a lifting table 213 supported so as to be movable in the Z-axis direction relative to the pair of guide rails 211. The lifting mechanism 21 rotates the ball screw 212 by the driving force of the motor 214, whereby the lifting table 213 moves in the Z-axis direction along the pair of guide rails 211.

[0030] The wafer holding part 20 is supported by a lift table 213, and the wafer holding part 20 moves in the Z-axis direction in accordance with the movement of the lift table 213. In other words, the lift mechanism 21 is configured to raise and lower the wafer holding part 20 with respect to the glass table 16.

[0031] The wafer holding part 20 includes a disk-shaped holding table 201. A disk-shaped porous member 202 (see FIG. 5) is provided on the lower surface side of the holding table 201. The lower surface of the porous member 202 is a wafer holding surface 203 located above the glass table 16. The wafer holding surface 203 is a surface approximately parallel to the placement surface 161 on which the sheet S is placed. In other words, the wafer holding part 20 is disposed opposite the glass table 16.

[0032] The porous member 202 communicates with a suction source (not shown) via a suction path. A suction force is applied to the porous member 202 by the operation of the suction source, and the upper surface Wa of the wafer W is suction-held by the wafer holding surface 203.

[0033] The wafer holding unit 20 includes a load detection unit 22. The load detection unit 22 detects the load applied to the lower surface Wb of the wafer W in the Z-axis direction.

[0034] An ultraviolet irradiation unit 23 is disposed below the circular glass table 160 constituting the glass table 16, which irradiates ultraviolet rays onto the liquid resin M dropped onto the sheet S on the placement surface 161. The ultraviolet irradiation unit 23 may be provided, for example, in an internal space formed by the support table 162 and the glass table 160 (see FIG. 2). The ultraviolet irradiation unit 23 includes a plurality of ultraviolet irradiation sections 231 (see FIG. 7) that emit ultraviolet rays, and irradiates the liquid resin M with ultraviolet rays UV as an external stimulus through the translucent glass table 160 and the sheet S, thereby hardening the liquid resin M. The light source used for the ultraviolet irradiation section 231 may be, for example, an LED.

[0035] The ultraviolet irradiating section 231 is an example of a curing unit that applies an external stimulus to the liquid resin M to harden the liquid resin M. When the liquid resin M is a thermosetting resin, the protective member forming apparatus 1 may have a curing unit configured to apply heat to the liquid resin M, such as an infrared irradiating section that irradiates infrared rays, instead of the ultraviolet irradiating section 231.

[0036] A second transport mechanism 25 is provided on the -X direction side of the base 15. The second transport mechanism 25 includes a robot hand 252 supported on a pedestal 251, and transports the wafer W between the temporary placement table 13 and the wafer holder 20 by moving the pedestal 251 in the Y-axis direction and operating the robot hand 252. The second transport mechanism 25 also transports the wafer W between the glass table 16 and the sheet cutting table 14.

[0037] The protective member forming apparatus 1 further includes a sheet wettability forming unit 27 and an insertion / removal mechanism 28. The sheet wettability forming unit 27 is fixed to the insertion / removal mechanism 28 provided in the vicinity of the glass table 16.

[0038] The sheet wettability forming unit 27 is a unit that irradiates the surface of the sheet S held on the glass table 16 with ultraviolet rays to improve the wettability of the surface of the sheet S. More specifically, the sheet wettability forming unit 27 irradiates the exposed upper surface of the sheet S held on the glass table 16 with ultraviolet rays. The exposed upper surface, surface Sa (see FIG. 2), is the surface with which the liquid resin M supplied from the resin supply nozzle 183 comes into contact with the sheet S (see FIG. 4), and the higher the wettability of this surface, the more easily the liquid resin M spreads over the sheet S.

[0039] The reason why wettability is improved by irradiating the surface of the sheet S with ultraviolet rays is that the surface is modified by the growth of hydrophilic functional groups such as OH groups, CO groups, CHO groups, and COOH groups on the surface of the sheet S. More specifically, ultraviolet rays break down oxygen molecules in the air to generate ozone, which in turn generates active oxygen. The generated active oxygen reacts with molecules on the surface of the sheet S whose molecular bonds have been cut by the ultraviolet rays to form new functional groups such as hydroxyl groups (also called hydroxyl groups, OH), carbonyl groups (CO), aldehyde groups (CHO), and carboxyl groups (COOH). These functional groups exhibit high wettability, that is, hydrophilicity. For this reason, irradiating the surface of the sheet S with ultraviolet rays improves wettability, making it easier for the liquid resin M to spread on the sheet S.

[0040] The insertion / removal mechanism 28 is configured to be rotatable around a rotation axis facing the Z-axis direction, and includes a support column 281 in which the rotation axis is housed, and a support column 282 extending horizontally from the support column 281. The sheet wettability forming unit 27 is fixed to a recess of the support column 282 that opens toward the glass table 16 side, and faces the glass table 16 side. When the insertion / removal mechanism 28 rotates around the rotation axis, the sheet wettability forming unit 27 moves together with the support column 282 from outside to inside or from inside to outside of the space between the glass table 16 and the wafer holding unit 20. As a result, the sheet wettability forming unit 27 is inserted between the glass table 16 and the wafer holding unit 20 or removed.

[0041] The protective member forming apparatus 1 is generally controlled by a control unit 40. The control unit 40 includes a processor that executes various processes, and a storage unit (memory) that stores various parameters, programs, etc. The storage unit of the control unit 40 includes, as part of a control program, a program that controls the sheet wettability forming unit 27 in a series of processes for forming a protective member on the wafer W, for example, to cause the sheet wettability forming unit 27 to perform an operation of irradiating the sheet S with ultraviolet light to improve the wettability of the surface of the sheet S.

[0042] According to the protective member forming apparatus 1 configured as described above, the sheet wettability forming unit 27 can improve the wettability of the surface of the sheet S, so that the liquid resin M dropped onto the sheet S can spread easily. As a result, when the liquid resin M is sandwiched between the wafer W and the sheet S, it is possible to spread the liquid resin M over the entire surface of the wafer W in a short time, and the protective member can be efficiently formed in a short time.

[0043] Furthermore, since adhesion is also high when there is high wettability, that is, when the contact angle is small and the adhesive is well adapted to the surface of the adherend, improving the wettability of the surface of the sheet S also contributes to improving the adhesion between the sheet S and the liquid resin M. For this reason, the protective member forming apparatus 1 can form a protective member that is firmly adhered to the wafer W.

[0044] Next, a method for forming a protective member by the protective member forming apparatus 1 according to this embodiment will be specifically described. Fig. 2 to Fig. 7 show each step in forming a protective member. Fig. 2 is an explanatory diagram showing a sheet supplying step. Fig. 3 is an explanatory diagram showing a wettability forming step. Fig. 4 is an explanatory diagram showing a liquid resin supplying step. Fig. 5 is an explanatory diagram showing a wafer holding step. Fig. 6 is an explanatory diagram showing a spreading step. Fig. 7 is an explanatory diagram showing a curing step.

[0045] 2 shows a sheet carrying-in process in forming a protective member. In the sheet carrying-in process, the control unit 40 controls the sheet conveying mechanism 17. The sheet conveying mechanism 17 clamps an end of the sheet S with the clamp unit 173 and moves the arm 172 in the +Y direction (see FIG. 1). As a result, the sheet S is pulled out from the sheet supply unit 171 and conveyed to the glass table 16 side. The pulled-out sheet S is cut to a predetermined length.

[0046] The control unit 40 operates the suction source to apply a suction force to the suction holes 163 and 164. As a result, the sheet S placed on the glass table 16 is sucked and held on the glass table 16. The area of ​​the sheet S at this stage is larger than the area of ​​the lower surface Wb of the wafer W.

[0047] FIG. 3 shows a wettability forming step in forming the protective member. In the wettability forming step, The sheet wettability forming unit 27 is positioned above the sheet S placed on the glass table 16 by the sheet carry-in process. This positioning is performed by the control unit 40 rotating the insertion / removal mechanism 28 so that the support part 282 to which the sheet wettability forming unit 27 is fixed is inserted between the glass table 16 and the wafer holding part 20.

[0048] After the sheet wettability forming unit 27 is positioned, the control unit 40 controls the sheet wettability forming unit 27, causing the sheet wettability forming unit 27 to irradiate ultraviolet rays onto the surface of the sheet S held on the glass table 16. The surface of the sheet S irradiated with ultraviolet rays is the surface Sa of the sheet S opposite the surface Sb of the sheet S held on the glass table 16. This improves the wettability of the surface (surface Sa) of the sheet S. When the irradiation of ultraviolet rays is completed, the control unit 40 rotates the insertion / removal mechanism 28 to retract the sheet wettability forming unit 27 from above the glass table 16, completing the wettability forming process.

[0049] 4 shows a liquid resin supplying step in forming a protective member. In the liquid resin supplying step, the resin supply nozzle 183 of the resin supplying mechanism 18 is positioned above the sheet S whose surface wettability has been improved by the sheet wettability forming step. The resin supply nozzle 183 is positioned above and near the center of the glass table 16. This positioning is performed by the control unit 40 controlling the sheet conveying mechanism 17, which moves the arm 172 in the Y-axis direction.

[0050] After the resin supply nozzle 183 is positioned, the control unit 40 controls the dispenser 181 so that the dispenser 181 delivers liquid resin M from the tank 184 to the resin supply nozzle 183 and drips the liquid resin M from the resin supply nozzle 183 onto the sheet S.

[0051] The liquid resin M dropped from the resin supply nozzle 183 falls near the center of the surface Sa of the sheet S. Since the wettability of the surface Sa of the sheet S has been improved by the previous process, the liquid resin M spreads from the center toward the periphery after falling.

[0052] The control unit 40 controls the dispenser 181 based on information such as the size of the wafer W, and supplies the liquid resin M to the sheet S in an amount (predetermined amount) sufficient to cover the entire lower surface Wb of the wafer W. When the supply of the predetermined amount of liquid resin M is completed, the control unit 40 moves the arm 172 to retract the resin supply nozzle 183 from above the glass table 16, thereby completing the liquid resin supply process.

[0053] Fig. 5 shows a wafer holding step in forming a protective member. Fig. 5 shows a state in which a wafer W is held by the wafer holding part 20 in the wafer holding step. In the wafer holding step, the wafer W before the formation of the protective member H (see Fig. 7) is taken out of the cassette C by the first transport mechanism 12. The wafer W is then handed over to the second transport mechanism 25, and the wafer W is transported to the wafer holding part 20. In the wafer holding part 20, a suction source is operated, so that a suction force acts on the porous member 202. The wafer holding part 20 uses this suction force to suck the upper surface Wa of the wafer W onto the wafer holding surface 203 and hold it.

[0054] At least a part of the wafer holding step may be performed in parallel (simultaneously) with the sheet carrying step, the wettability forming step, and the liquid resin supplying step.

[0055] Fig. 6 shows the spreading step in forming the protective member. When the wafer W held by the wafer holding part 20 is positioned above and facing the liquid resin M on the sheet S (see Fig. 5), the process proceeds to the spreading step shown in Fig. 6. In the spreading step, the motor 214 of the lifting mechanism 21 is controlled by the control part 40 to lower the lifting table 213 and the holding table 201 at a predetermined feed speed.

[0056] As the holding table 201 descends, the lower surface Wb of the wafer W approaches the glass table 16 and comes into contact with the liquid resin M. Then, the liquid resin M is pressed by the lower surface Wb of the wafer W, and the liquid resin M is spread in the radial direction of the wafer W. The liquid resin M just before coming into contact with the lower surface Wb of the wafer W is in a state in which it has spread to some extent due to the high wettability of the surface Sa of the sheet S after being dropped onto the surface Sa of the sheet S. By pressing the liquid resin M that has spread to some extent with the wafer W, the liquid resin M is further spread toward the outer edge side of the wafer W, and the entire surface of the wafer W can be covered with the liquid resin M in a short time.

[0057] When adjusting the amount of lowering of the holding table 201 in accordance with the spreading state of the liquid resin M, the motor 214 may be controlled by the control unit 40 based on the detection result of the load detection unit 22 .

[0058] FIG. 7 shows the curing process in forming the protective member. In the curing process, the control unit 40 controls the ultraviolet irradiation unit 23, and the ultraviolet irradiation unit 23 irradiates ultraviolet rays with an intensity and wavelength that cures the liquid resin M. More specifically, the ultraviolet rays emitted from the ultraviolet irradiation unit 231 toward the mounting surface 161 pass through the glass table 160 and the sheet S to reach the liquid resin M, which is an ultraviolet curable resin, and cure the liquid resin M. When the liquid resin M is sufficiently cured, the ultraviolet irradiation unit 23 stops irradiating the ultraviolet rays. By the curing of the liquid resin M, a protective member H consisting of the resin HM obtained by curing the liquid resin M and the sheet S is formed so as to cover the entire lower surface Wb of the wafer W, and the lower surface Wb of the wafer W is protected by the protective member H covering the entire lower surface Wb of the wafer W.

[0059] In the above embodiment, in the process of forming the protective member H, the wettability of the surface of the sheet S constituting the protective member H is improved before supplying the liquid resin M. Therefore, even if a special sheet is not used as the sheet S and, for example, the same sheet as in the past is used, it is possible to spread the liquid resin M over the entire lower surface Wb of the wafer W in a short time, and as a result, the protective member H can be efficiently formed in a short time. Also, the liquid resin M may be spread out after improving the wettability of the lower surface Wb of the wafer W.

[0060] In addition, the improved wettability of the surface improves the adhesive strength between the liquid resin M, which acts as an adhesive, and the sheet S. As a result, a protective member H that is firmly adhered to the wafer W can be formed.

[0061] Since the protective member H will be peeled off later, the liquid resin M is selected from those that have good removability. Therefore, even if the adhesive strength is improved by improving the wettability, peeling will not be excessively difficult. When peeling the protective member H from the wafer W, the protective member H may be ground with a grinding wheel. At that time, the protective member H may be irradiated with ultraviolet light again to further harden the protective member H, and then ground with a grinding wheel.

[0062] Fig. 8 is an explanatory diagram showing another example of the wettability forming step in forming the protective member, and Fig. 9 is an explanatory diagram showing another example of the liquid resin supplying step in forming the protective member.

[0063] In the above-described embodiment, an example is shown in which the resin supply nozzle 183 supplies liquid resin M onto the sheet S held on the glass table 16, but the resin supply nozzle 183 may supply liquid resin M not only onto the sheet S held on the glass table, but also onto the wafer W held in the wafer holding section.

[0064] Hereinafter, a method for forming a protective member by a protective member forming apparatus according to another embodiment in which a liquid resin M is supplied onto a wafer W to form a protective member H will be described with reference to FIGS.

[0065] First, the configuration of the protective member forming apparatus according to this embodiment shown in Fig. 8 and Fig. 9 will be described in terms of differences from the protective member forming apparatus 1. The protective member forming apparatus according to this embodiment is different from the protective member forming apparatus 1 in that it includes a sheet holding part 50 instead of the glass table 16 which is the sheet holding part, a wafer holding part 70 instead of the wafer holding part 20, a lifting mechanism 21 lifts and lowers the sheet holding part 50 instead of the wafer holding part 70, and a wafer sheet wettability forming unit 32 in addition to the sheet wettability forming unit 31. Note that in this embodiment, an example will be described in which a wafer W having a wafer sheet WS attached to the surface on which bumps B are formed is used.

[0066] The sheet holding unit 50 differs from the glass table 16 in that it is arranged with a holding surface 511 facing vertically downward, but other configurations are similar to those of the glass table 16. The sheet holding unit 50 is a glass table in the broad sense that holds the sheet S, including a glass table 51 and a support table 54. The glass table 51 and the support table 54 correspond to the glass table 160 and the support table 162 of the glass table 16, respectively.

[0067] The sheet holding section 50 is similar to the glass table 16 in that it houses an ultraviolet ray irradiation unit 53 including a plurality of ultraviolet ray irradiation sections 531 therein. The sheet holding section 50 is also similar to the glass table 16 in that it suction-holds the sheet S. The sheet holding section 50 operates the suction source 60 to generate a suction force on the holding surface 511 of the sheet holding section 50 via the suction path 52, and sucks and holds the sheet S on the holding surface 511. The ultraviolet ray irradiation unit 53 and the ultraviolet ray irradiation section 531 correspond to the ultraviolet ray irradiation unit 23 and the ultraviolet ray irradiation section 231, respectively.

[0068] The wafer holding unit 70 differs from the wafer holding unit 20 in that the wafer holding unit 70 is arranged with a wafer holding surface 73 facing vertically upward, but the other configurations are similar to those of the wafer holding unit 20. The wafer holding unit 70 includes a holding table 71 and a porous member 72, and operates a suction source 80 to generate a suction force on the wafer holding surface 73, which is the surface of the porous member 72, to suction-hold the wafer W on the wafer holding surface 73. The holding table 71, the porous member 72, and the wafer holding surface 73 correspond to the holding table 201, the porous member 202, and the wafer holding surface 203 of the wafer holding unit 20, respectively.

[0069] In the protective member forming apparatus of this embodiment, the arrangement of the sheet holding unit 50 (glass table 16) and the wafer holding unit 70 (wafer holding unit 20) is upside down compared to the protective member forming apparatus 1, so that the liquid resin M discharged from the resin supply nozzle 183 is dripped onto the wafer W, more specifically, onto the surface WSa, which is the upper surface of the wafer sheet WS adhered to the surface of the wafer W.

[0070] In order for the dropped liquid resin M to spread on the surface WSa, it is desirable that the wettability of the surface WSa is high. The liquid resin M is sandwiched between the surface WSa and the surface Sa, which is the lower surface of the sheet S held by the sheet holding unit 50, and is spread in the radial direction of the wafer W. Therefore, in order to spread the liquid resin M in a short time, it is desirable that both surfaces that the liquid resin M comes into contact with have high wettability, that is, that not only the surface WSa of the wafer W but also the surface Sa of the sheet S have high wettability. In consideration of this point, the protective member forming device according to this embodiment includes a sheet wettability forming unit 31 and a wafer sheet wettability forming unit 32.

[0071] The sheet wettability forming unit 31 irradiates ultraviolet light onto the surface (surface Sa) of the sheet S held by the sheet holding part 50 (glass table) to improve the wettability of the surface (surface Sa) of the sheet S. Meanwhile, the wafer sheet wettability forming unit 32 irradiates ultraviolet light onto the surface WSa of the wafer sheet WS attached to the surface of the wafer W held by the wafer holding part 70 to improve the wettability of the surface WSa of the wafer sheet WS. The sheet wettability forming unit 31 and the wafer sheet wettability forming unit 32 are fixed to an insertion / removal mechanism 30 provided near the sheet holding part 50 and the wafer holding part 70.

[0072] The insertion / removal mechanism 30 is configured to be rotatable around a rotation axis facing the Z-axis direction, and includes a support column 300 in which the rotation axis is housed, and a support column 301 and a support column 302 extending horizontally from the support column 300. The support column 301 and the support column 302 are supported by the support column 300 in a state where they are stacked vertically. The sheet wettability forming unit 31 is fixed to a recess of the support column 301 that opens toward the sheet holding section 50 side of the support column 301 and the support column 302, and faces the sheet holding section 50 side. The wafer sheet wettability forming unit 32 is fixed to a recess of the support column 302 that opens toward the wafer holding section 70 side of the support column 301 and the support column 302, and faces the wafer holding section 70 side.

[0073] By rotating the insertion / removal mechanism 30 around the rotation axis, the sheet wettability forming unit 31 and the wafer sheet wettability forming unit 32 move from outside to inside or from inside to outside of the space between the sheet holding unit 50 and the wafer holding unit 70 together with the support parts 301 and 302. As a result, the sheet wettability forming unit 31 and the wafer sheet wettability forming unit 32 are inserted or removed between the sheet holding unit 50 and the wafer holding unit 70.

[0074] The protective member forming apparatus according to this embodiment configured as above also forms a protective member in a procedure similar to that of the protective member forming apparatus 1. Specifically, first, the protective member forming apparatus performs a sheet supplying step and a wafer holding step. As a result, the sheet S and the wafer W are held by the sheet holding unit 50 and the wafer holding unit 70, respectively. Thereafter, the protective member forming apparatus performs a wettability forming step shown in FIG. 8.

[0075] 8 shows the wettability forming step in forming the protective member. In the wettability forming step, the sheet wettability forming unit 31 and the wafer sheet wettability forming unit 32 are positioned between the wafer holding part 70 and the sheet holding part 50. Such positioning is performed by the control part 40 rotating the insertion / removal mechanism 30, so that the support part 301 to which the sheet wettability forming unit 31 is fixed and the support part 302 to which the wafer sheet wettability forming unit 32 is fixed are inserted between the sheet holding part 50 and the wafer holding part 70.

[0076] After the sheet wettability forming unit 31 and the wafer sheet wettability forming unit 32 are positioned, the control unit 40 controls the sheet wettability forming unit 31 and the wafer sheet wettability forming unit 32, so that the sheet wettability forming unit 31 irradiates ultraviolet light onto the surface Sa of the sheet S held by the sheet holding unit 50, and the wafer sheet wettability forming unit 32 irradiates ultraviolet light onto the surface WSa of the wafer sheet WS of the wafer W held by the wafer holding unit 70. This improves the wettability of the surfaces (surface Sa, surface WSa) of the sheet S and the wafer sheet WS.

[0077] When the irradiation of ultraviolet rays is completed, the control unit 40 rotates the insertion / removal mechanism 30 to retract the sheet wettability forming unit 31 and the wafer sheet wettability forming unit 32 from between the sheet holding unit 50 and the wafer holding unit 70, completing the wettability forming process. When the wettability forming process is completed, the liquid resin supplying process is performed.

[0078] 9 shows a liquid resin supplying step in forming a protective member. In the liquid resin supplying step, a resin supply nozzle 183 is positioned above the wafer sheet WS whose surface wettability has been improved by the sheet wettability forming step. The resin supply nozzle 183 is positioned above the vicinity of the center of the wafer holder 70.

[0079] After the resin supply nozzle 183 is positioned, the control unit 40 controls the dispenser 181 to send liquid resin M from the tank 184 to the resin supply nozzle 183, and the liquid resin M is dripped from the resin supply nozzle 183 onto the wafer sheet WS. The liquid resin M dripped from the resin supply nozzle 183 falls near the center of the surface WSa of the wafer sheet WS. Since the wettability of the surface WSa of the wafer sheet WS has been improved by the previous process, the liquid resin M spreads from the center toward the periphery after falling. When the liquid resin supply process is completed, the pushing and spreading process is performed.

[0080] In the spreading step, the control unit 40 controls the motor 214 of the lifting mechanism 21 to lower the support table 54 at a predetermined feed rate. The lowering of the support table 54 causes the surface Sa of the sheet S to approach the wafer holding unit 70 and come into contact with the liquid resin M. The surface Sa of the sheet S presses the liquid resin M, spreading the liquid resin M in the radial direction of the wafer W. The liquid resin M just before the surface Sa of the sheet S comes into contact with the surface Sa of the sheet S is in a state in which it has spread to some extent due to the high wettability of the surface WSa after being dropped onto the surface WSa of the wafer sheet WS. By pressing the liquid resin M that has spread to some extent with the wafer W, the liquid resin M can be further spread toward the outer edge side of the wafer W, and the entire surface of the wafer W can be covered with the liquid resin M in a short time. In particular, in this embodiment, ultraviolet rays are irradiated not only to the surface WSa of the wafer sheet WS but also to the surface Sa of the sheet S, improving the wettability of both sides that sandwich the liquid resin M, making it easier for the liquid resin M to spread. Therefore, the liquid resin M can be spread over the entire surface of the wafer W in an even shorter time.

[0081] Finally, a curing step is performed. In the curing step, the control unit 40 controls the ultraviolet irradiation unit 53, and the ultraviolet irradiation unit 53 irradiates ultraviolet light with an intensity and wavelength that cures the liquid resin M. This cures the liquid resin M, and a protective member composed of the cured liquid resin M and the sheet S is formed on the wafer sheet WS. The curing step is similar to the curing step shown in FIG. 7 performed by the protective member forming apparatus 1, except that ultraviolet light is irradiated from above.

[0082] In the above embodiment, in the process of forming the protective member, the wettability of the surface of the adherend (sheet S, wafer W) that comes into contact with the liquid resin is improved before supplying the liquid resin M. This makes it possible to spread the liquid resin M between the sheet S and the wafer W over the entire top surface of the wafer sheet WS of the wafer W in a short time, and as a result, the protective member H can be efficiently formed in a short time.

[0083] In addition, after grinding the side of the wafer W opposite to the side on which the protective member H is formed with a grinding wheel, dicing tape may be attached to the ground surface and the ring frame to mount the wafer on the ring frame, and then the protective member H may be removed together with the wafer sheet WS.

[0084] The embodiments of the present invention are not limited to the above-mentioned embodiments, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea of ​​the present invention. Furthermore, if the technical idea of ​​the present invention can be realized in a different way due to technological progress or a different derived technology, the present invention may be implemented using that method. Therefore, the claims cover all embodiments that may be included within the scope of the technical idea of ​​the present invention.

[0085] In the above embodiment, an example was shown in which the wettability forming unit irradiates ultraviolet light onto the surface to be improved in wettability, but the wettability forming unit may irradiate plasma instead of or in addition to ultraviolet light. Even when the wettability forming unit irradiates plasma, hydrophilic functional groups such as OH groups, CO groups, CHO groups, and COOH groups are formed on the surface by the oxygen plasma, so that wettability can be improved in the same way as when ultraviolet light is irradiated.

[0086] In the above embodiment, an example was shown in which the sheet wettability forming unit irradiates ultraviolet light onto the surface whose wettability should be improved, but the sheet wettability forming unit may irradiate plasma instead of or in addition to ultraviolet light. Even when the sheet wettability forming unit irradiates plasma, hydrophilic functional groups such as OH groups, CO groups, CHO groups, and COOH groups are formed on the surface by the oxygen plasma, so that wettability can be improved in the same way as when ultraviolet light is irradiated.

[0087] In the above-described embodiment, a glass table is exemplified as the sheet holding unit that holds the placed sheet S, but the sheet holding unit is not limited to a glass table as long as it is a table that holds the sheet S. In addition, in a configuration in which the curing unit applies an external stimulus to the liquid resin via the sheet holding unit, it is preferable that the sheet holding unit does not hinder the transmission of the external stimulus. For example, in the case where the external stimulus is ultraviolet light as in the above-described embodiment, it is preferable that the sheet holding unit is a table made of a light-transmitting material, for example, a glass table.

[0088] In the above-described embodiment, an example has been shown in which the lifting mechanism 21 is configured to raise and lower the wafer holding part 20 relatively to the glass table 16 functioning as the sheet holding part, and an example has been shown in which the lifting mechanism 21 raises and lowers the sheet holding part 50 (glass table 51) relatively to the wafer holding part 70. In other words, it is sufficient that the lifting mechanism 21 is configured to raise and lower the wafer holding part and the sheet holding part relatively, and it may raise and lower only one of the wafer holding part and the sheet holding part, or may raise and lower both. [Industrial Applicability]

[0089] As described above, the protective member forming apparatus of the present invention can improve the wettability of the surface of the sheet that the liquid resin comes into contact with, thereby making it easier for the liquid resin to spread and improving the adhesiveness after curing. Therefore, it is possible to form a firmly adhered protective member on the surface of a wafer in a short time, and is useful in a protective member forming apparatus that forms a protective member on the surface of a wafer using a liquid resin. [Explanation of symbols]

[0090] 1: Protective material forming device 16, 51, 160: Glass table 18:Resin supply mechanism 20, 70: Wafer holder 21: Lifting mechanism 23, 53: UV irradiation unit 27, 31: Sheet wettability forming unit 32: Wafer sheet wettability forming unit 40: Control section 50: Sheet holding part 54, 162: Support table 71, 201: Holding table 72, 202: Porous materials 73, 203: Wafer holding surface 161: Placement surface 183: Resin supply nozzle 231, 531: UV irradiation unit 511: Holding surface H: Protective material M: Liquid resin S: Seat Sa, Sb, WSa: Surface W: Wafer WS: Wafer sheet

Claims

1. A protective member forming apparatus for forming a protective member for protecting an entire surface of one side of a wafer by spreading and hardening a liquid resin over the entire surface of the one side of the wafer, a sheet holding portion for holding a sheet; a wafer holding part arranged opposite to the sheet holding part and holding a wafer; a liquid resin supply nozzle that supplies a liquid resin onto the sheet held by the sheet holding part or onto the wafer held by the wafer holding part; a lifting mechanism for lifting and lowering the sheet holding part and the wafer holding part relative to each other; a curing unit that applies an external stimulus to the liquid resin to cure the liquid resin; a wettability forming unit that irradiates a surface of the sheet held by the sheet holding unit with ultraviolet light or plasma to improve the wettability of the surface of the sheet; A protective member forming apparatus comprising:

2. The protective member forming apparatus of claim 1, further comprising a wafer sheet wettability forming unit that irradiates ultraviolet light or plasma onto the surface of a wafer sheet attached to the surface of the wafer held by the wafer holding portion to improve the wettability of the surface of the wafer sheet.

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