Protective film forming apparatus

Abstract

To easily grasp the remaining amount of liquid resin.SOLUTION: The height of a tank 81 changes depending on the amount of liquid resin remaining in the tank 81. When the strength of a signal received by a reading unit 85 according to the distance between a wireless communication tag 84 placed in the tank 81 and the reading unit 85 exceeds a preset strength, a determination unit 86 determines that the remaining amount of liquid resin in the tank 81 is reduced, and thus a replacement timing for the tank 81 has come. Therefore, there is no need to submerge a remaining amount sensor in the liquid resin of the tank 81 to determine whether the remaining amount of liquid resin in the tank 81 is reduced and thus the replacement timing for the tank 81 has come. This makes it possible to easily detect the replacement timing for the tank 81, and also prevent deterioration of the quality of the liquid resin due to the sensor being submerged in the liquid.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] As disclosed in Patent Documents 1 and 2, there is a processing method (ablation processing) in which a laser beam having an absorbent wavelength is irradiated onto a wafer to form a processed groove in the wafer. In this method, a processed groove is formed between devices formed on the upper surface of the wafer.

[0003] In order to protect the devices on the top surface of the wafer before forming the processed grooves, there is a technique for forming a protective film by applying a liquid resin to the top surface of the wafer, as disclosed in Patent Document 3. This protective film prevents debris generated when the wafer melts due to irradiation with a laser beam from adhering to the devices. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-320466 A [Patent Document 2] JP 2006-140311 A [Patent Document 3] JP 2007-173475 A [Patent Document 4] JP 2014-175461 A Summary of the Invention [Problem to be solved by the invention]

[0005] In an apparatus for forming a protective film from liquid resin as described above, as disclosed in Patent Document 4, the liquid resin is sucked up from a tank containing the liquid resin and applied to the upper surface of the wafer.

[0006] This protective film forming device is equipped with a rod-shaped sensor that detects when the liquid resin is low. This sensor is submerged in the liquid resin in the tank, with its tip located near the bottom of the tank. When the liquid resin is low, the tip of the sensor becomes exposed above the liquid resin surface, thereby detecting that the remaining amount is low. However, this technique requires a structure for submerging the sensor in the liquid resin, and there is a risk that the quality of the liquid resin will deteriorate due to the sensor being submerged in the liquid resin.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to easily grasp the remaining amount of liquid resin. [Means for solving the problem]

[0008] A first protective film forming apparatus of the present invention is a protective film forming apparatus that applies liquid resin to a wafer to form a protective film, and includes a tank mounting stage for mounting a tank for storing liquid resin, a biasing unit that biases the tank mounting stage in one direction, a wireless communication tag disposed on the tank, a reading unit that is disposed in a housing of the apparatus and reads the wireless communication tag of the tank mounted on the tank mounting stage, and a judgment unit that judges that the remaining amount of liquid resin in the tank is low and that it is time to replace the tank when the received signal strength of the reading unit, which is based on the distance between the reading unit and the wireless communication tag disposed on the tank, whose position changes in the one direction depending on the remaining amount of liquid resin in the tank and the biasing force of the biasing unit, exceeds a predetermined set strength.

[0009] A second protective film forming apparatus of the present invention is a protective film forming apparatus that applies liquid resin to a wafer to form a protective film, and includes a tank mounting stage for mounting a tank for storing liquid resin, a biasing unit that biases the tank mounting stage in one direction, a wireless communication tag placed on the tank, a reading unit that is disposed in a housing of the apparatus and reads the wireless communication tag of the tank placed on the tank mounting stage, and a determination unit that detects the remaining amount of liquid resin in the tank based on the received signal strength of the reading unit in response to the distance between the reading unit and the wireless communication tag placed on the tank, whose position changes in the one direction depending on the remaining amount of liquid resin in the tank and the biasing force of the biasing unit. Effect of the Invention

[0010] In the first protective film forming device, the distance between the wireless communication tag placed in the tank and the reading unit placed in the housing changes depending on the position of the tank in one direction (the biasing direction of the biasing unit). Furthermore, the position of the tank changes depending on the balance between the remaining amount of liquid resin in the tank and the biasing force of the biasing unit. Therefore, the position of the tank is a position that depends on the remaining amount of liquid resin in the tank. Then, when the receiving signal strength of the reading unit according to the distance between the wireless communication tag and the reading unit exceeds a preset set strength, the judgment unit judges that the remaining amount of liquid resin in the tank is low and that it is time to replace the tank. Therefore, there is no need to submerge the remaining amount sensor in the liquid resin in the tank to determine whether the remaining amount of liquid resin in the tank is low and it is time to replace the tank. This makes it easy to detect when the tank needs to be replaced, and also prevents deterioration of the quality of the liquid resin due to the sensor being submerged in the liquid.

[0011] In the second protective film forming device, the distance between the wireless communication tag and the reading unit changes depending on the position of the tank in one direction, and the position of the tank is a position corresponding to the remaining amount of the liquid resin in the tank. In the second protective film forming device, the determination unit detects the remaining amount of the liquid resin in the tank based on the received signal strength of the reading unit according to the distance between the wireless communication tag and the reading unit. Therefore, even with this configuration, there is no need to submerge the remaining amount sensor in the liquid resin in the tank in order to detect the remaining amount of liquid resin in the tank. This makes it possible to easily detect the remaining amount of liquid resin in the tank and also prevents deterioration of the quality of the liquid resin due to the sensor being submerged in the liquid. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is an explanatory diagram showing a configuration of a laser processing device. [Diagram 2] FIG. 2 is a perspective view showing a configuration of a protective film forming apparatus. [Diagram 3] FIG. 2 is an explanatory diagram showing a configuration of a protective film forming apparatus. [Figure 4] 4 is an explanatory diagram showing a configuration of a liquid resin delivery mechanism in the protective film forming apparatus. FIG. [Diagram 5] 5(a) and (b) are explanatory diagrams showing other configurations of the liquid resin delivery mechanism. [Figure 6] 6(a) and (b) are explanatory diagrams showing other configurations of the liquid resin delivery mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The laser processing apparatus 1 shown in FIG. 1, the wafer 100 is, for example, a disk-shaped semiconductor wafer, and has on its upper surface lattice-shaped dividing lines 102. In each of the regions partitioned by the dividing lines 102, a device (not shown) is formed.

[0014] In this embodiment, the wafer 100 is handled in the state of a work set 110. The work set 110 is formed by integrating an annular ring frame 111 having an opening 112 capable of accommodating the wafer 100 with the wafer 100 positioned in the opening 112 of the ring frame 111 by a dicing tape 113. The wafer 100 is laser processed in the laser processing apparatus 1 in the state of such a work set 110.

[0015] The laser processing apparatus 1 is configured to form a plurality of device chips by dividing the wafer 100 of the work set 110 configured in this manner along the planned dividing lines 102.

[0016] As shown in FIG. 1, the laser processing apparatus 1 includes a base 2 that supports and houses each of the components that make up the laser processing apparatus 1. A first opening 2a is provided at a corner on the front end side of the base 2. A cassette support base 131 that moves (lifts) along the Z-axis direction by a lifting mechanism (not shown) is provided inside the first opening 2a. A cassette 13 that can accommodate a plurality of work sets 110 is mounted on the cassette support base 131.

[0017] Further, a first transport unit 15 for transporting the wafer 100 is provided on the +Y direction side of the first opening 2a. The first transport unit 15 is configured to be movable along the Y-axis direction, and transports the work set 110 in and out of the cassette 13.

[0018] Further, between the first opening 2a and the first transport unit 15, there is provided a temporary placement area 12 in which a work set 110 to be carried in or out of the cassette 13 is temporarily placed. A pair of guide rails 14 arranged parallel to each other along the Y-axis direction is provided in the temporary placement area 12. The pair of guide rails 14 move toward and away from each other along the X-axis direction while sandwiching a ring frame 111 therebetween, thereby aligning the work set 110.

[0019] A second transport unit 16 that transports the work set 110 is provided near the temporary placement area 12. The second transport unit 16 includes, for example, a plurality of suction pads (not shown) that suction-hold the upper surface side of the ring frame 111 in the work set 110. The second transport unit 16 holds the work set 110 aligned in the temporary placement area 12, and transports it to the protective film forming apparatus 7.

[0020] The protective film forming device 7 has a spinner table 50 that holds the wafer 100 of the work set 110, and forms a protective film on the upper surface of the wafer 100 to protect devices on the wafer 100. The protective film forming device 7 also has a function of cleaning the wafer 100 that has been laser-processed.

[0021] A third transfer unit 17 is provided above the protective film forming device 7 to transfer the wafer 100 between the chuck table 20 and the protective film forming device 7. The third transfer unit 17 includes, for example, a plurality of suction pads that suction-hold the upper surface side of the ring frame 111. The work set 110 including the wafer 100 on which the protective film is formed is transferred to the chuck table 20 by the third transfer unit 17.

[0022] The chuck table 20 is provided on a movable table 18 arranged in the rectangular second opening 2b in the base 2. The movable table 18 is a flat table movable in the X-axis direction, and is provided so as to cover the second opening 2b together with a bellows-shaped dust-proof and drip-proof cover 19 that expands and contracts along the X-axis direction.

[0023] The upper surface of the chuck table 20 is a flat surface that is approximately parallel to the horizontal direction (XY plane direction) and constitutes a holding surface 22 that holds the wafer 100. The holding surface 22 is connected to a suction source (not shown) via a flow path, a valve, and the like provided inside the chuck table 20. In addition, a plurality of clamps 24 that grip and fix the ring frame 111 of the work set 110 are provided around the periphery of the chuck table 20.

[0024] In the chuck table 20 having such a configuration, the wafer 100 of the work set 110 transported by the third transport unit 17 is suction-held by the holding surface 22 connected to a suction source, and the ring frame 111 is gripped by the clamp 24. This allows the chuck table 20 to hold the work set 110 well. In addition, the chuck table 20 is rotated by a rotation mechanism (not shown) disposed below the chuck table 20 about a rotation axis that passes through the center of the holding surface 22 and extends in the Z-axis direction.

[0025] In addition, an X-axis direction moving mechanism (not shown) that moves the moving table 18 and the chuck table 20 along the X-axis direction is provided below the moving table 18. This X-axis direction moving mechanism positions the chuck table 20 between a transfer region R1 where the work set 110 is transferred to the holding surface 22 and a processing region R2 where the wafer 100 is processed. After holding the work set 110 in the transfer region R1, the chuck table 20 is moved to the processing region R2 by the X-axis direction moving mechanism.

[0026] An imaging unit 5 is provided on the movement path of the chuck table 20 (between the transfer region R1 and the processing region R2). The imaging unit 5 captures an image of the wafer 100 held by the chuck table 20. The image acquired by the imaging unit 5 is used, for example, for aligning the wafer 100 for laser processing.

[0027] A laser irradiation unit 26 that irradiates a laser beam is provided in the processing region R2. The laser irradiation unit 26 includes a head 28 arranged above the chuck table 20 located in the processing region R2, a laser oscillator (not shown), and a moving mechanism (not shown) that moves the head 28.

[0028] In the laser irradiation unit 26, a laser beam emitted from a laser oscillator is irradiated from a head 28 along the planned division lines 102 of the wafer 100 held on the chuck table 20. This causes the wafer 100 to be laser processed. Specifically, the wafer 100 is divided along the planned division lines 102 to form a plurality of device chips. At this time, since the wafer 100 is held integrally by the dicing tape 113, the wafer 100 is prevented from falling apart.

[0029] After the wafer 100 is laser processed, the chuck table 20 is returned to the transfer region R1. Then, the work set 110 on the chuck table 20 is transferred by the third transfer unit 17 to the protective film forming apparatus 7, where it is cleaned.

[0030] The cleaned wafer 100 is transferred onto the pair of guide rails 14 by the second transfer unit 16 and then housed in the cassette 13 by the first transfer unit 15.

[0031] A support stand 3 is provided on the +Y direction side of the processing region R2, and a display unit 31 is mounted on the support stand 3. The display unit 31 displays various information related to the laser processing apparatus 1. An input unit 32 for inputting various information to the laser processing apparatus 1 is provided on the edge of the base 2 on the -Y direction side. The input unit 32 may be an operation panel equipped with a plurality of operation keys, a mouse, a keyboard, or the like.

[0032] The laser processing apparatus 1 also includes a control unit 8, which is a control device. The control unit 8 includes a CPU that performs calculation processing according to a control program, and a storage medium such as a memory. The control unit 8 controls the above-mentioned members of the laser processing apparatus 1 to perform laser processing on the wafer 100.

[0033] Here, the above-mentioned protective film forming apparatus 7 will be described in more detail. The protective film forming apparatus 7 forms a protective film on the wafer 100 and cleans the wafer 100. That is, the protective film forming apparatus 7 functions as a protective film forming unit and a cleaning unit.

[0034] 2, the protective film forming apparatus 7 includes a spinner table 50 that can rotate while holding a work set 110. The upper surface of the spinner table 50 serves as a holding surface 51 that holds the wafer 100 of the work set 110. The holding surface 51 is connected to a suction source (not shown) via a flow path, a valve, and the like provided inside the spinner table 50.

[0035] When the work set 110 is held by the spinner table 50, an area of ​​the dicing tape 113 in the work set 110 where the wafer 100 is attached is placed on the holding surface 51. Then, in the spinner table 50, the holding surface 51 is connected to a suction source, so that the wafer 100 is suction-held by the holding surface 51 via the dicing tape 113.

[0036] The spinner table 50 may be provided with a clamp for gripping the ring frame 111 of the work set 110.

[0037] A rotation drive source 52 such as a motor that rotates the spinner table 50 is connected to the spinner table 50. The rotation drive source 52 is equipped with a cylindrical spindle (output shaft) 54 arranged along the vertical direction, and the upper end of the spindle 54 is connected to the center of the lower surface side of the spinner table 50. When the spindle 54 is rotated, the spinner table 50 rotates about a rotation axis perpendicular to the holding surface 51.

[0038] A lifting unit 56 is connected to the rotary drive source 52. The lifting unit 56 is equipped with a plurality of air cylinders 58 fixed to the rotary drive source 52. A cylindrical support leg 60 that supports the air cylinder 58 is attached to the lower end of each air cylinder 58. When the plurality of air cylinders 58 are operated simultaneously, the spinner table 50 and the rotary drive source 52 are raised and lowered in the vertical direction.

[0039] The spinner table 50 is surrounded by a liquid receiving member 64. The liquid receiving member 64 is formed in a hollow cylindrical shape and is supported by three support legs 65. The liquid receiving member 64 includes an annular outer wall 641 surrounding the spinner table 50, an annular bottom surface 642 protruding from the lower end of the outer wall 641 toward the radially inward side of the liquid receiving member 64, and an annular inner wall 643 protruding upward from the radially inner end of the bottom surface 642. The inside of the inner wall 643 is an insertion port 644 into which the spindle 54 is inserted.

[0040] 2 and 3, an annular cover 66 is provided inside the liquid receiving member 64 so as to surround the spindle 54 below the spinner table 50. The cover 66 is disposed so as to overlap with an inner wall 643 of the liquid receiving member 64. By covering the upper part of the inner wall 643 with the cover 66, it is possible to prevent the liquid present inside the liquid receiving member 64 from flowing out to the outside of the liquid receiving member 64 through the insertion port 644.

[0041] 2, a drainage port 68 is provided in a bottom surface 642 of the liquid receiving member 64, and a drainage path 70 is connected to the drainage port 68. The liquid stored in the liquid receiving member 64 is discharged to the outside of the liquid receiving member 64 via the drainage port 68 and the drainage path 70.

[0042] In addition, provided inside the liquid receiving member 64 are a liquid resin supply unit 72 that supplies liquid resin to the wafer 100, a cleaning liquid supply unit 74 that supplies cleaning liquid to the wafer 100, and an air blow unit 77 that blows air onto the wafer 100.

[0043] The cleaning liquid supply unit 74 includes an arm 741 formed in a hollow cylindrical shape, and a cleaning liquid supply nozzle 742 connected to the tip of the arm 741. A rotation drive source (not shown) such as a motor is also connected to the arm 741. By rotating the arm 741 by the rotation drive source, the cleaning liquid supply nozzle 742 can be positioned at a position overlapping the spinner table 50 (supply position) and a position not overlapping the spinner table 50 (retracted position).

[0044] The cleaning liquid supply unit 74 is connected to a cleaning liquid supply source (not shown) that supplies the cleaning liquid. The cleaning liquid supplied from the cleaning liquid supply source to the arm 741 is dropped from the cleaning liquid supply nozzle 742 onto the wafer 100 held on the holding surface 51 of the spinner table 50.

[0045] The air blow unit 77 has an upper air blow mechanism 75 for blowing air from above onto the wafer 100 held on the holding surface 51 of the spinner table 50, and a lower air blow mechanism 76 for blowing air from below onto the ring frame 111 of the work set 110.

[0046] Upper air blow mechanism 75 includes arm 751 formed in a hollow cylindrical shape, and upper air nozzle 752 connected to the tip of arm 751. A rotation drive source 753 (see FIG. 3) such as a motor is also connected to arm 751. By rotating arm 751 by rotation drive source 753, upper air nozzle 752 can be positioned between a position overlapping spinner table 50 (supply position) and a position not overlapping spinner table 50 (retracted position).

[0047] The upper air blow mechanism 75 is connected to an air supply source (not shown) that supplies air. Air supplied from the air supply source to the arm 751 is sprayed from the upper air nozzle 752 toward the wafer 100 held on the holding surface 51 of the spinner table 50.

[0048] The lower air blow mechanism 76 includes an arm 761 (see FIG. 3) formed in a hollow cylindrical shape, and a lower air nozzle 762 connected to the tip of the arm 761. The lower air blow mechanism 76 is connected to an air supply source (not shown) that supplies air. Air supplied from the air supply source to the arm 761 is sprayed from the lower air nozzle 762 toward the underside of the ring frame 111 of the work set 110 held on the spinner table 50.

[0049] The liquid resin supply unit 72 includes an arm 721 formed in a hollow cylindrical shape, and a liquid resin supply nozzle 722 connected to the tip of the arm 721. A rotation drive source 723 (see FIG. 3) such as a motor is also connected to the arm 721. By rotating the arm 721 by this rotation drive source 723, the liquid resin supply nozzle 722 can be positioned between a position overlapping the spinner table 50 (supply position) and a position not overlapping the spinner table 50 (retracted position).

[0050] Moreover, the protective film forming device 7 has a liquid resin delivery mechanism 80 which accumulates liquid resin and delivers the liquid resin to the liquid resin supply nozzle 722 of the liquid resin supply unit 72. The liquid resin delivered from the liquid resin delivery mechanism 80 to the arm 721 of the liquid resin supply unit 72 is dripped from the liquid resin supply nozzle 722 onto the upper surface of the wafer 100 held on the holding surface 51 of the spinner table 50.

[0051] Here, the configuration of the liquid resin delivery mechanism 80 provided in the protective film forming device 7 will be described. As shown in Fig. 1, liquid resin feed mechanism 80 is disposed in base 2 of laser processing apparatus 1. As shown in Fig. 4, liquid resin feed mechanism 80 includes tank 81 for storing liquid resin, tank mounting stand 82 for mounting tank 81, biasing unit 83 for biasing tank mounting stand 82 in one direction (upward direction), wireless communication tag 84 disposed in tank 81, reader 85 for reading wireless communication tag 84, and determination unit 86 for acquiring the strength of a signal received by reader 85.

[0052] Tank 81 has a substantially rectangular parallelepiped shape and is configured to store liquid resin therein. The liquid resin stored in tank 81 is, for example, a solution containing a water-soluble resin. Examples of water-soluble resins include PVA (polyvinyl alcohol), PEG (polyethylene glycol), PEO (polyethylene oxide), and PVP (polyvinylpyrrolidone).

[0053] The liquid resin delivery mechanism 80 is placed on a tank mounting base 82. The tank mounting base 82 is supported from below by a biasing unit 83. The biasing unit 83 biases the tank 81 and the tank mounting base 82 in one direction (the upward direction) and is composed of, for example, a coil spring-like member (e.g., a compression spring) having a certain spring constant. The biasing unit 83 is disposed between the bottom surface of the recess 211 provided in the bottom surface 21 of the base 2 and the lower surface of the tank 81.

[0054] In this configuration, the positions of the tank 81 and the tank mounting base 82 in one direction (the biasing direction of the biasing portion 83), i.e., the heights of the tank 81 and the tank mounting base 82, change according to the remaining amount of liquid resin in the tank 81 and the biasing force of the biasing portion 83. That is, the height of the tank 81 changes according to the balance between the remaining amount of liquid resin in the tank 81 and the biasing force of the biasing portion 83. Therefore, the height of the tank 81 is a height according to the remaining amount of liquid resin in the tank 81. That is, when the remaining amount of liquid resin in the tank 81 is large, the tank 81 becomes heavy, so that the tank 81 and the tank mounting base 82 move down in the recess 211 against the biasing force of the biasing portion 83. On the other hand, when the remaining amount of liquid resin in the tank 81 becomes small, the tank 81 becomes lighter, so that the tank 81 and the tank mounting base 82 move up due to the biasing force of the biasing portion 83.

[0055] The wireless communication tag 84 is disposed on the upper surface of the tank 81. In this embodiment, the wireless communication tag 84 stores at least the type of liquid resin stored in the tank 81. The wireless communication tag 84 transmits the stored information to the reading unit 85 by using a wireless signal.

[0056] In this embodiment, the wireless communication tag 84 is, for example, an RFID (Radio Frequency Identification) tag. In this case, the RFID tag includes a control circuit including an IC and a memory, an antenna used for transmitting and receiving information, and a power source. The memory of the RFID tag stores information such as the type of liquid resin, expiration date, and manufacturer.

[0057] The reading unit 85 receives a radio signal output from the wireless communication tag 84 and reads information stored in the wireless communication tag 84. If the wireless communication tag 84 is an RFID tag, the reading unit 85 has a function as an RFID reader. The reading unit 85 outputs the information read from the wireless communication tag 84 to the control unit 8, for example.

[0058] In this embodiment, the reading unit 85 is disposed on a support member 90 provided on the bottom surface 21 of the base 2, which is part of the housing of the protective film forming apparatus 7. Specifically, the support member 90 has a vertical wall portion 91 supported on the bottom surface 21, and a horizontal wall portion 92 extending horizontally from an upper end portion of the vertical wall portion 91. The reading unit 85 is attached to the lower surface of the horizontal wall portion 92 in a position facing the wireless communication tag 84 of the tank 81.

[0059] In this way, the reading unit 85 is disposed on the housing (bottom surface 21 of the base 2) of the protective film forming apparatus 7 via the support member 90, and reads the wireless communication tag 84 of the tank 81 placed on the tank mounting stand 82.

[0060] Since the reading unit 85 is disposed in the housing of the protective film forming device 7, the position (height) of the reading unit 85 does not change even if the remaining amount of liquid resin in the tank 81 changes. Meanwhile, since the wireless communication tag 84 is attached to the upper surface of the tank 81, the height of the wireless communication tag 84 depends on the remaining amount of liquid resin in the tank 81. Therefore, the distance between the wireless communication tag 84 and the reading unit 85 depends on the remaining amount of liquid resin in the tank 81, and becomes closer as the remaining amount decreases.

[0061] The determination unit 86 of the liquid resin delivery mechanism 80 is configured to acquire the strength of the signal (received signal strength) received by the reading unit 85 from the wireless communication tag 84. The received signal strength is, for example, a current value or a voltage value related to the received signal.

[0062] The liquid resin delivery mechanism 80 also includes a suction nozzle 95 for sucking out the liquid resin in the tank 81 at the tip side of the horizontal wall portion 92 of the support member 90. The liquid resin delivery mechanism 80 also includes a dispenser 96 that is connected to the suction nozzle 95 and delivers a predetermined amount of liquid resin to the liquid resin supply nozzle 722 of the liquid resin supply unit 72 shown in FIG. 3 etc. The liquid resin delivery mechanism 80 is capable of delivering the liquid resin in the tank 81 to the liquid resin supply nozzle 722 by the suction nozzle 95 and dispenser 96.

[0063] In this embodiment, as described above, when the amount of liquid resin in the tank 81 decreases, the position of the tank 81 becomes higher. Therefore, the suction port (tip) of the suction nozzle 95 for the liquid resin remains in the liquid resin of the tank 81 (below the liquid surface) even when the remaining amount of liquid resin in the tank 81 decreases.

[0064] The operation of forming a protective film on the wafer 100 in the protective film forming apparatus 7 will be described below. When forming a protective film on the wafer 100, first, the control unit 8 (see FIG. 1) reads information on the wireless communication tag 84 in the tank 81 using the reading unit 85 of the liquid resin delivery mechanism 80. Based on this information, the control unit 8 determines, for example, whether the liquid resin in the tank 81 is appropriate. Note that the timing for reading the information on the wireless communication tag 84 may be when the tank 81 is placed on the tank mounting table 82.

[0065] When it is determined that the liquid resin is appropriate, the control unit 8 proceeds with the operation of forming the protective film. That is, the control unit 8 places the work set 110 on the spinner table 50 by the second transport unit 16 shown in Fig. 1. Then, the control unit 8 connects the holding surface 22 to the suction source, thereby suction-holding the wafer 100 in the work set 110 by the holding surface 51, as described above.

[0066] Thereafter, the control unit 8 lowers the spinner table 50 using the lifting unit 56 shown in Fig. 2. As a result, the wafer 100 is positioned inside the liquid receiving member 64, and the upper part of the insertion opening 644 is covered with the cover 66.

[0067] Next, the control unit 8 positions the liquid resin supply nozzle 722 directly above (at the supply position) the wafer 100 by the rotary drive source 723 shown in Fig. 3. Then, the control unit 8 rotates the spinner table 50 by the rotary drive source 52. Furthermore, the control unit 8 controls the dispenser 96 of the liquid resin delivery mechanism 80 shown in Fig. 4 to suck a predetermined amount of liquid resin from the tank 81 and deliver it to the liquid resin supply nozzle 722. As a result, the liquid resin as a protective film material is dripped from the liquid resin supply nozzle 722 onto the upper surface of the wafer 100 rotating together with the spinner table 50.

[0068] The liquid resin dropped onto the center of the top surface of the rotating wafer 100 spreads over the entire top surface. The liquid resin is then dried to form a protective film that covers the top surface of the wafer 100. In this manner, the protective film forming apparatus 7 including the liquid resin delivery mechanism 80 applies liquid resin to the wafer 100 to form a protective film.

[0069] In addition, in this embodiment, during such protective film formation operation, the judgment unit 86 of the liquid resin feed mechanism 80 judges whether or not it is time to replace the tank 81 based on the strength of the signal received by the reading unit 85.

[0070] That is, as described above, the distance between the wireless communication tag 84 placed in the tank 81 and the reading unit 85 corresponds to the remaining amount of liquid resin in the tank 81, and the smaller the remaining amount, the closer the distance. Also, the strength of the signal received by the reading unit 85 becomes stronger as the distance between the wireless communication tag 84 and the reading unit 85 becomes shorter. Therefore, the strength of the signal received by the reading unit 85 corresponds to the remaining amount of liquid resin in the tank 81.

[0071] Therefore, in this embodiment, the reading unit 85 reads information from the wireless communication tag 84, for example, at the timing when the liquid resin is sucked out of the tank 81 by the dispenser 96. Then, the determination unit 86 acquires the signal strength of the reading unit 85 during this reading, and when the received signal strength exceeds a preset strength (a set current value or a set voltage value), determines that the remaining amount of liquid resin in the tank 81 is low and that it is time to replace the tank 81. Then, the determination unit 86 notifies the operator that it is time to replace the tank 81, for example, using the display unit 31 shown in FIG. 1.

[0072] As described above, in this embodiment, the distance between the wireless communication tag 84 arranged in the tank 81 and the reading unit 85 arranged in the housing (bottom surface 21 of the base 2) of the protective film forming apparatus 7 changes depending on the position (height) of the tank 81 in the biasing direction of the biasing unit 83. Furthermore, the height of the tank 81 changes depending on the remaining amount of liquid resin in the tank 81. Then, when the reception signal strength of the reading unit 85 according to the distance between the wireless communication tag 84 and the reading unit 85 exceeds a preset set strength, the determination unit 86 determines that the remaining amount of liquid resin in the tank 81 is low and that it is time to replace the tank 81.

[0073] Therefore, in this embodiment, it is not necessary to submerge the remaining amount sensor in the liquid resin of the tank 81 in order to determine whether the remaining amount of liquid resin in the tank 81 has become low and it is time to replace the tank 81. This makes it possible to easily detect the time to replace the tank 81, and also prevents deterioration in the quality of the liquid resin due to the sensor being submerged in the liquid.

[0074] In this embodiment, when the liquid resin is sucked out of the tank 81 by the dispenser 96, the reading unit 85 reads the information from the wireless communication tag 84, and the determination unit 86 acquires the strength of the signal received during this reading to determine whether or not it is time to replace the tank 81. In this regard, the determination as to whether or not it is time to replace the tank 81 may be performed at other times. For example, this determination may be performed immediately before the start of the protective film forming operation, after the protective film forming operation is completed, or when the processing recipe for the protective film formation is changed (for example, when the processing recipe is changed to a recipe that uses a different type of liquid resin or a recipe that uses a different amount of resin to be applied).

[0075] In addition, in the above-described embodiment, the judgment unit 86 judges whether or not it is time to replace the tank 81 by determining whether or not the received signal strength of the reading unit 85 exceeds a preset set strength.

[0076] In this regard, as described above, the remaining amount of liquid resin in the tank 81 is determined according to the distance between the wireless communication tag 84 and the reading unit 85, and further, the distance between the wireless communication tag 84 and the reading unit 85 is obtained according to the strength of the signal received by the reading unit 85. For this reason, the determination unit 86 may be configured to obtain the distance between the wireless communication tag 84 and the reading unit 85 based on the strength of the signal received by the reading unit 85, and to detect the remaining amount of liquid resin in the tank 81 based on this distance. That is, the determination unit 86 may be configured to detect the remaining amount of liquid resin in the tank 81 based on the strength of the signal received by the reading unit 85 according to the distance between the wireless communication tag 84 and the reading unit 85, which is placed in the tank 81 and whose position (height) changes in one direction (upward direction) according to the remaining amount of liquid resin in the tank 81 and the biasing force of the biasing unit 83.

[0077] In this configuration, the determination unit 86 can detect the specific remaining amount of liquid resin in the tank 81. Furthermore, there is no need to submerge the remaining amount sensor in the liquid resin in the tank 81 in order to detect the remaining amount. Therefore, the remaining amount of liquid resin in the tank 81 can be easily detected, and deterioration in the quality of the liquid resin due to the sensor being submerged in the liquid can also be prevented.

[0078] In this configuration, the determination unit 86 may display the detected remaining amount of liquid resin in the tank 81 to the worker using the display unit 31. This allows the worker to easily grasp the remaining amount of liquid resin in the tank 81.

[0079] In this configuration, it is preferable that the determination unit 86 recognizes the strength of the signal received by the reading unit 85 when the liquid resin in the tank 81 is empty. This allows the determination unit 86 to more accurately detect the remaining amount of liquid resin in the tank 81.

[0080] In addition, in this configuration, the judgment unit 86 detects the remaining amount of liquid resin in the tank 81, for example, immediately before the start of the protective film forming operation, after the protective film forming operation is completed, when the liquid resin is sucked out of the tank 81 by the dispenser 96, or when the processing recipe is changed.

[0081] In this configuration, the determination unit 86 may determine whether or not the tank 81 will need to be replaced during the operation based on the remaining amount of liquid resin in the tank 81 before starting the protective film forming operation on a predetermined number of wafers 100, and display the determination result to the operator using the display unit 31. This allows the operator to avoid replacing the tank 81 midway by replacing the tank 81 in advance before the protective film forming operation when it looks like the tank 81 will need to be replaced midway. This makes it possible to maintain a uniform quality of the protective film formed on the predetermined number of wafers 100.

[0082] In this embodiment, the biasing unit 83 in the liquid resin delivery mechanism 80 is configured to bias the tank 81 in an upward direction. In this regard, the biasing unit 83 may be configured to bias the tank 81 obliquely upward, as shown in Fig. 5(a).

[0083] In this configuration, a recess 211 provided on the bottom surface 21 of the base 2 is formed to have a slightly inclined bottom surface. A tank mounting platform 82 has wheels 87 on its lower surface, and is disposed in the recess 211 so as to be movable along the bottom surface of the recess 211 together with the tank 81. Furthermore, a biasing part 83 which is a compression spring is disposed between the side surface of the tank mounting platform 82 and the side surface of the recess 211, and biases the tank mounting platform 82 in one direction, i.e., in the upward direction along the inclined bottom surface of the recess 211.

[0084] Furthermore, the tank 81 placed on the tank mounting table 82 is provided with a wireless communication tag 84 on the upper side of the tank 81. Furthermore, a reading unit 85 is provided near a recess 211 in the bottom surface 21 of the base 2, which is the housing of the protective film forming apparatus 7. More specifically, the reading unit 85 is provided near the recess 211 in the bottom surface 21 so as to face the surface of the tank 81 on which the wireless communication tag 84 is provided. The wireless communication tag 84 may be provided at a position facing the reading unit 85 on the side surface of the tank 81 .

[0085] Even in this configuration, the positions of the tank 81 and the tank mounting base 82 in one direction (the biasing direction of the biasing portion 83) change according to the remaining amount of liquid resin in the tank 81 and the biasing force of the biasing portion 83. That is, the position of the tank 81 changes according to the balance between the remaining amount of liquid resin in the tank 81 and the biasing force of the biasing portion 83. Therefore, the position of the tank 81 is a position according to the remaining amount of liquid resin in the tank 81.

[0086] Therefore, when a large amount of liquid resin remains in the tank 81, the tank 81 becomes heavy, and as shown in FIG. 5(b), the tank 81 and the tank mounting base 82 descend diagonally downward within the recess 211, away from the reading unit 85, against the biasing force of the biasing unit 83. On the other hand, when the amount of liquid resin remaining in the tank 81 becomes low, the tank 81 becomes lighter, and as shown in Figure 5 (a), the tank 81 and the tank mounting base 82 rise diagonally upward due to the biasing force of the biasing portion 83 so as to approach the reading portion 85.

[0087] Here, since the reading unit 85 is disposed in the housing of the protective film forming device 7, the position of the reading unit 85 does not change even if the remaining amount of liquid resin in the tank 81 changes. Meanwhile, the position of the wireless communication tag 84 attached to the side surface of the tank 81 is a position according to the remaining amount of liquid resin in the tank 81. Therefore, the distance between the wireless communication tag 84 and the reading unit 85 is a distance according to the remaining amount of liquid resin in the tank 81, and the smaller the remaining amount, the closer the distance becomes. Also, the strength of the signal received by the reading unit 85 becomes stronger as the distance between the wireless communication tag 84 and the reading unit 85 becomes closer.

[0088] In this manner, even in this configuration, the distance between the wireless communication tag 84 disposed in the tank 81 and the reading unit 85 disposed in the housing of the protective film forming device 7 changes depending on the remaining amount of liquid resin in the tank 81. Then, for example, when the received signal strength of the reading unit 85 according to the distance between the wireless communication tag 84 and the reading unit 85 exceeds a preset set strength, the determination unit 86 determines that the remaining amount of liquid resin in the tank 81 is low and that it is time to replace the tank 81.

[0089] Therefore, even with this configuration, there is no need to submerge the remaining amount sensor in the liquid resin of the tank 81 in order to determine whether or not it is time to replace the tank 81. This makes it possible to easily detect when the tank 81 needs to be replaced, and also prevents deterioration in the quality of the liquid resin due to the sensor being submerged in the liquid.

[0090] 5(a) and 5(b), the determination unit 86 may be configured to determine the distance between the wireless communication tag 84 and the reading unit 85 based on the strength of a signal received by the reading unit 85, and to detect the remaining amount of liquid resin in the tank 81 based on this distance. That is, the determination unit 86 may be configured to detect the remaining amount of liquid resin in the tank 81 based on the strength of a signal received by the reading unit 85 according to the distance between the reading unit 85 and the wireless communication tag 84 disposed in the tank 81, the position of which changes in one direction (the biasing direction of the biasing unit 83) depending on the remaining amount of liquid resin in the tank 81 and the biasing force of the biasing unit 83.

[0091] 5(a) and (b), the biasing unit 83 may be formed of a tension spring. In this case, as shown in FIG. 6(a), one end of the biasing unit 83 is attached to a side surface of the recess 211 in the bottom surface 21 of the base 2, the side being closer to the reading unit 85. The other end of the biasing unit 83 is attached to a side surface of the tank mounting base 82. The biasing unit 83 biases (pulls) the tank mounting base 82 in one direction, that is, in a direction to rise along the bottom surface of the inclined recess 211.

[0092] Even with this configuration, if there is a large amount of liquid resin remaining in the tank 81, the tank 81 becomes heavy, and as a result, as shown in Figure 6 (b), the tank 81 and the tank mounting base 82 descend diagonally downward within the recess 211 against the biasing force of the biasing portion 83. On the other hand, when the amount of liquid resin remaining in the tank 81 becomes low, the tank 81 becomes lighter, and as a result, the tank 81 and the tank mounting base 82 rise (are pulled up) diagonally upward by the force of the biasing section 83 so as to approach the reading section 85, as shown in Figure 6(a).

[0093] Therefore, the judgment unit 86 can determine that it is time to replace the tank 81 or detect the remaining amount of liquid resin in the tank 81, for example, based on the received signal strength of the reading unit 85 depending on the distance between the wireless communication tag 84 and the reading unit 85.

[0094] In the configuration shown in FIGS. 5(a)(b) or 6(a)(b), the bottom surface of the recess 211 provided in the bottom surface 21 of the base 2 may be a substantially horizontal surface. In this case, for example, when a compression spring is used as the biasing portion 83, the tank 81 placed on the tank mounting base 82 is loaded with liquid resin, and the tank mounting base 82 is placed in a position (initial position) such that the biasing portion 83 is in a contracted state (see Figure 5 (b)).

[0095] In this configuration, when there is a large amount of liquid resin remaining in the tank 81, the tank 81 is heavy, so the tank 81 and the tank mounting base 82 remain positioned in their initial positions against the biasing force of the biasing portion 83. On the other hand, when the remaining amount of liquid resin in the tank 81 becomes small, the tank 81 becomes lighter, and the tank 81 and the tank mounting base 82 are moved in the direction in which the biasing portion 83 extends by the biasing force of the biasing portion 83 (see Figure 5 (a)).

[0096] Therefore, even in this configuration, the distance between the wireless communication tag 84 and the reading unit 85 changes depending on the remaining amount of liquid resin in the tank 81. Therefore, the determination unit 86 can determine that it is time to replace the tank 81 or detect the remaining amount of liquid resin in the tank 81 based on the received signal strength of the reading unit 85 according to this distance. [Explanation of symbols]

[0097] 1: laser processing device, 2: base, 2a: first opening, 2b: second opening, 3: support stand, 5: imaging unit, 7: protective film forming device, 8: control unit, 12: temporary placement area, 13: cassette, 14: guide rail, 15: first transport unit, 16: second transport unit, 17: third transport unit, 18: moving table, 19: cover, 20: chuck table, 21: bottom surface, 22: holding surface, 24: clamp, 26: laser irradiation unit, 28: head, 31: display unit, 32: input unit, 50: spinner table, 51: holding surface, 52: rotation drive source, 54: spindle, 56: lifting unit, 58: air cylinder, 60: support leg, 64: liquid receiving member, 65: Support leg, 66: Cover, 68: Drain port, 70: Drain path, 72: liquid resin supply unit, 74: cleaning liquid supply unit, 75: upper air blow mechanism, 76: lower air blow mechanism, 77: air blow unit, 80: liquid resin delivery mechanism, 81: tank, 82: tank mounting base, 83: biasing unit, 84: wireless communication tag, 85: reader, 86: judgement unit, 90: support member, 91: vertical wall portion, 92: horizontal wall portion, 95: suction nozzle, 96: dispenser, 100: wafer, 102: division line, 110: work set, 111: ring frame, 112: opening, 113: dicing tape, 131: cassette support base, 211: recess, 641: outer wall, 642: bottom surface, 643: inner wall, 644: insertion port, 721: arm, 722: liquid resin supply nozzle, 723: rotation drive source, 741: arm, 742: cleaning liquid supply nozzle, 751: arm, 752: upper air nozzle, 753: rotation drive source, 761: Arm, 762: Lower air nozzle, R1: Transport area, R2: Processing area

Claims

1. A protective film forming apparatus for applying a liquid resin to a wafer to form a protective film, a tank mounting base for mounting a tank for storing liquid resin; A biasing portion that biases the tank mounting table in one direction; A wireless communication tag disposed in the tank; a reading unit that is disposed in a housing of the device and that reads the wireless communication tag of the tank placed on the tank placement stand; a determination unit that determines that the amount of liquid resin remaining in the tank is low and that it is time to replace the tank when a signal strength received by the reading unit corresponding to a distance between the reading unit and the wireless communication tag disposed in the tank, the position of which changes in the one direction depending on the amount of liquid resin remaining in the tank and the biasing force of the biasing unit, exceeds a preset strength; A protective film forming apparatus comprising:

2. A protective film forming apparatus for applying a liquid resin to a wafer to form a protective film, a tank mounting base for mounting a tank for storing liquid resin; A biasing portion that biases the tank mounting table in one direction; A wireless communication tag disposed in the tank; a reading unit that is disposed in a housing of the device and that reads the wireless communication tag of the tank placed on the tank placement stand; a determination unit that detects the remaining amount of liquid resin in the tank based on the remaining amount of liquid resin in the tank and the strength of a signal received by the reading unit according to the distance between the reading unit and the wireless communication tag disposed in the tank, the position of which changes in the one direction according to the biasing force of the biasing unit; A protective film forming apparatus comprising:

Images