Liquid resin coating device

Abstract

To provide a liquid resin coating device in which mist-like liquid resin does not roll up from an opening of a housing even when a lid body is opened in a case in which a wafer coated with a protective film is carried out from a spinner table.SOLUTION: A laser processing device includes a rotatable spinner table 32 holding a wafer W, a liquid resin supply nozzle 44 for supplying a liquid resin to an upper surface Wa of the wafer held on the spinner table, a motor 35 that rotates the spinner table, a housing 41 surrounding the spinner table and having exhaust means 42 at a lower part, and control means. After the liquid resin is supplied to the upper surface of the wafer held by the spinner table, the control means spreads the liquid resin over the upper surface of the wafer by rotating the spinner table driven by the motor, and intermittently stops the rotation of the spinner table and controls the exhaust means to exhaust liquid resin mist floating inside the housing.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a liquid resin coating device for coating a liquid resin on the upper surface of a wafer.

Background Art

[0002] A wafer having a plurality of devices such as ICs and LSIs formed on a surface partitioned by a dicing line is diced into individual device chips by a laser processing apparatus and used in electric devices such as mobile phones and personal computers.

[0003] The laser processing apparatus includes at least a liquid resin coating device for coating a protective film of a liquid resin on the surface of a wafer, a chuck table for holding the wafer coated with the protective film, a laser beam irradiating means for irradiating a laser beam onto the wafer held by the chuck table, a feeding means for relatively feeding the chuck table and the laser beam irradiating means, and a cleaning means for cleaning the laser-processed wafer and removing the protective film from the surface of the wafer, and can perform processing with high precision without adhering debris to the surface of the wafer (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the liquid resin coating device disposed in the above-described laser processing apparatus, after a protective film of liquid resin is coated on the upper surface of the wafer held by the spinner table, when the lid for closing the opening of the housing surrounding the spinner table is opened, there is a problem that mist-like liquid resin remaining inside the housing is lifted up and discharged to the outside through the opening of the housing, and there is a problem of contaminating the periphery of the liquid resin coating device, the inside of the laser processing apparatus in which the liquid resin coating device is disposed, and the periphery of a clean room or the like. Such problems are not limited to the case where the liquid resin coating device is disposed in a laser processing apparatus, and may similarly occur when the liquid resin coating device is disposed in other processing apparatuses or when the liquid resin coating device has only the function of coating a wafer with liquid resin alone.

[0006] The present invention has been made in view of the above facts, and its main technical problem is to provide a liquid resin coating device in which, when the wafer coated with the protective film is carried out from the spinner table, even if the lid is opened, mist-like liquid resin does not roll up from the opening of the housing.

Means for Solving the Problem

[0007] In order to solve the above main technical problem, according to the present invention, there is provided a liquid resin coating device for coating a liquid resin on the upper surface of a wafer, including a spinner table capable of holding and rotating the wafer, a liquid resin supply nozzle for supplying the liquid resin onto the upper surface of the wafer held by the spinner table, a motor for rotating the spinner table, a housing having an opening at the upper part for allowing the wafer to enter and exit, surrounding the spinner table, and having an exhaust means at the lower part, a lid for closing the opening of the housing, and a control means. The control means spreads the liquid resin on the upper surface of the wafer by rotating the spinner table driven by the motor after the liquid resin is supplied onto the upper surface of the wafer held by the spinner table, and intermittently stops the rotation of the spinner table to control the exhaust means to exhaust the mist of the liquid resin floating inside the housing.

Effect of the Invention

[0008] The liquid resin coating apparatus of the present invention is a liquid resin coating apparatus for coating a liquid resin on the upper surface of a wafer, comprising a spinner table for holding and rotating the wafer, a liquid resin supply nozzle for supplying the liquid resin to the upper surface of the wafer held by the spinner table, a motor for rotating the spinner table, a housing having an opening at the upper part for allowing the loading and unloading of the wafer, surrounding the spinner table, and having an exhaust means at the lower part, a lid for closing the opening of the housing, and a control means. The control means spreads the liquid resin on the upper surface of the wafer by rotating the spinner table driven by the motor after the liquid resin is supplied to the upper surface of the wafer held by the spinner table, and intermittently stops the rotation of the spinner table to control the exhaust means to exhaust the mist of the liquid resin floating inside the housing. Thus, when forming a protective film by supplying the liquid resin on the upper surface of the wafer and unloading the wafer from the spinner table, the problem that mist-like liquid resin is lifted from the opening of the housing and contaminates the periphery when the lid closing the housing is opened is solved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of a liquid resin coating apparatus configured based on the present invention will be described in detail with reference to the accompanying drawings.

[0011] FIG. 1 shows an overall perspective view of a laser processing apparatus 2 to which a liquid resin coating apparatus 30 according to the present embodiment is attached. The laser processing apparatus 2 is an apparatus that performs laser processing on a wafer W prepared as a plate-like object to be processed.

[0012] On the front side of the laser processing apparatus 2, an operation means 4 for an operator to input instructions such as processing conditions is provided. On the upper part of the laser processing apparatus 2, a display means 6 for displaying a guidance screen for the operator and processing conditions by the laser processing apparatus 2 is provided.

[0013] The laser processing apparatus 2 is provided with a wafer cassette 8 capable of accommodating a plurality of wafers W integrated with an annular frame F via an adhesive tape T as shown on the left side of FIG. 1. The wafer cassette 8 is placed on a cassette elevating means 9 that can move up and down.

[0014] On the rear side of the wafer cassette 8, a loading / unloading means 10 for unloading the wafer W before laser processing from the wafer cassette 8 and loading the processed wafer W into the wafer cassette 8 is provided. Between the wafer cassette 8 and the loading / unloading means 10, a temporary placement means 12 having an alignment function for temporarily placing the wafer W to be loaded / unloaded and aligning the wafer W held by the frame F at a fixed position is provided.

[0015] Near the temporary placement means 12, a transfer means 16 having a swivel arm for adsorbing and transferring the frame F holding the wafer W is provided. The wafer W unloaded from the wafer cassette 8 onto the temporary placement means 12 by the loading / unloading means 10 is adsorbed by the transfer means 16 and transferred to the liquid resin coating apparatus 30.

[0016] The liquid resin coating apparatus 30 of the present embodiment has a function of supplying a liquid resin to the upper surface of the wafer W and coating it as a protective film, and also functions as a cleaning means for removing debris and the like attached by laser processing together with the liquid resin from the upper surface of the wafer W after laser processing. The liquid resin supplied by the liquid resin coating apparatus 30 is not particularly limited, but is, for example, a water-soluble liquid resin, and more specifically, is adopted from polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and the like. The liquid resin coating apparatus 30 will be described in detail later.

[0017] The laser processing apparatus 2 is provided with a chuck table 18 that functions as a holding means for holding the wafer W. The wafer W whose upper surface is coated with a protective film of liquid resin by the liquid resin coating apparatus 30 is adsorbed by the transfer means 17 and transferred to the loading / unloading position where the chuck table 18 is positioned in FIG. 1. The transfer means 17 includes an adsorption means 17b having an adsorption pad 17a for adsorbing the frame F that supports the wafer W on its lower surface, and a lid 17c for closing the opening 36a of the housing 41 of the cover portion 40 of the liquid resin coating apparatus 30. The transfer means 17 can move the adsorption means 17b and the lid 17c forward and backward in the Z-axis direction (vertical direction) in FIG. 1 by the action of an air cylinder (not shown).

[0018] The wafer W transferred to the chuck table 18 is sucked to the chuck table 18 via the adhesive tape T, and the frame F is fixed by a plurality of clamps 19. The chuck table 18 is provided with a processing feed means (not shown) for relatively processing and feeding the laser beam irradiation means 24 described later and the chuck table 18. The processing feed means is configured to be able to rotationally drive the chuck table 18 and move it in the X-axis direction indicated by the arrow X in the figure and the Y-axis direction indicated by the arrow Y orthogonal to the X-axis direction. Further, above the movement path of the chuck table 18 in the X-axis direction, a camera 22 of the alignment means 20 for detecting the position on the wafer W where laser processing is to be performed (for example, the division planned line on the wafer W) is disposed.

[0019] At a position adjacent in the X-axis direction of the above-described camera 22, a laser beam irradiation means 24 is disposed. The laser beam irradiation means 24 includes a casing 26 that houses an optical system (not shown) that oscillates a laser beam having a wavelength that is absorbent to the wafer W, and a condenser 28 for condensing and irradiating the laser beam. Ablation processing can be performed on the upper surface of the wafer W by the laser beam irradiated from the condenser 28.

[0020] The wafer W subjected to ablation processing by the laser beam irradiation means 24 is moved to the loading / unloading position on the front side in the figure together with the chuck table 18, adsorbed by the transfer means 17, and transferred to the liquid resin coating device 30 to perform the above-described removal and cleaning of the protective film.

[0021] The wafer W that has been cleaned by the liquid resin coating device 30 and from which the protective film has been removed from the upper surface is adsorbed by the frame F that supports the wafer W by the transfer means 16 and transferred to the temporary placement means 12, and then returned to the original storage location of the wafer cassette 8 by the above-described loading / unloading means 10.

[0022] Each operating unit such as the display means 6, the loading / unloading means 10, the transfer means 16 and 17, the alignment means 20, the laser beam irradiation means 24, and the liquid resin coating device 30 in the laser processing apparatus 2 is connected to a control means 100 constituted by a computer and is appropriately controlled. In FIG. 1, for convenience of explanation, the control means 100 is shown outside the laser processing apparatus 2, but actually, it is housed inside the laser processing apparatus 2.

[0023] Regarding the above-described liquid resin coating device 30, in addition to FIG. 1, it will be further specifically described with reference to FIG. 2.

[0024] As shown in Fig. 2, the liquid resin coating apparatus 30 includes a table mechanism 31 and a cover portion 40 surrounding the table mechanism 31. Fig. 2 is a perspective view of the liquid resin coating apparatus 30, and for the convenience of explanation, a part of the front side of the housing 41 constituting the cover portion 40 is cut away and shown. As understood from Fig. 2, the table mechanism 31 includes a spinner table 32 that holds the wafer W together with the frame F. The spinner table 32 is composed of a suction chuck 321 formed of a porous member having air permeability and a frame portion 322 surrounding the suction chuck 321. The suction chuck 321 is connected to a suction means (not shown), and a suction negative pressure is generated on the upper surface of the suction chuck 321. Further, the table mechanism 31 includes a shaft portion 34 and is connected to a motor 35 via a rotating shaft (not shown) housed inside the shaft portion 34. The rotating shaft is driven by the motor 35 to rotationally drive the spinner table 32. A plurality of air pistons 36 are arranged on the outer periphery of the motor 35, and by advancing and retracting the rod 36a in the vertical direction indicated by the arrow R1 in the figure by the air pistons 36, the spinner table 32, the shaft portion 34, and the motor 35 are integrally lifted and lowered. The above-described shaft portion 34 and the motor 35 function as a base for supporting the spinner table 32.

[0025] The housing 41 disposed in the cover portion 40 has an opening 41a that allows the wafer W to be taken in and out upward, and an exhaust means 42 for exhausting the mist-like liquid resin discharged into the housing 41 is provided on the bottom surface 41b constituting the lower portion of the housing 41. The exhaust means 42 includes an exhaust port 421, an exhaust hose 422, and a suction source 423. Further, the exhaust means 42 of the present embodiment has a function of exhausting the mist-like liquid resin when the liquid resin is coated on the wafer W, and also has a function of discharging the cleaning liquid supplied to the wafer W when the liquid resin coating apparatus 30 functions as a cleaning means.

[0026] Inside the above-described housing 41, there are arranged a liquid resin supply nozzle 44 having a tip portion 44a for supplying a liquid resin to the upper surface of the wafer W held by the spinner table 32, an air injection nozzle 45 having a tip portion 45a for injecting air to the upper surface of the wafer W, and a cleaning liquid supply nozzle 46 having a tip portion 46a for injecting a cleaning liquid (water in this embodiment) to the upper surface of the wafer W. By operating a driving means (not shown in FIG. 2) arranged on the back side of the bottom surface 41b of the housing 41, the tip portions 44a, 45a, and 46a of the respective nozzles can be swung in the horizontal directions indicated by arrows R2, R3, and R4 above the spinner table 32. As shown in FIG. 2, when the spinner table 32 is positioned at the position (lifting position) for loading and unloading the wafer W, the liquid resin supply nozzle 44, the air injection nozzle 45, and the cleaning liquid supply nozzle 46 are positioned at the storage positions in the outer peripheral side direction.

[0027] The above-described liquid resin coating apparatus 30 is merely one embodiment of the present invention. The liquid resin coating apparatus 30 configured based on the present invention includes at least, as shown in FIG. 2, a spinner table 32 capable of holding and rotating the wafer W, a liquid resin supply nozzle 44 for supplying a liquid resin to the upper surface of the wafer W held by the spinner table 32, a motor 35 for rotating the spinner table 32, a housing 41 having an opening 41a at the upper part for allowing the loading and unloading of the wafer W and surrounding the spinner table 32 and having an exhaust means 42 at the lower part, a lid 17c for closing the opening 41a of the housing 41 shown in FIG. 1, and a control means 100 for controlling the motor 35, the liquid resin supply nozzle 44, and the exhaust means 42. As will be described below, it is required that the motor 35, the liquid resin supply nozzle 44, and the exhaust means 42 are controlled. In this embodiment, an example in which the lid 17c for closing the opening 41a of the housing 41 of the liquid resin coating apparatus 30 is arranged on the conveying means 17 is shown, but the lid 17c may be installed independently of the conveying means 17.

[0028] The laser processing apparatus 2 equipped with the liquid resin coating apparatus 30 of the present embodiment has the configuration generally as described above, and the operation and effects thereof will be described below.

[0029] When performing laser processing in the above-described laser processing apparatus 2, by operating the loading and unloading means 10 described with reference to FIG. 1, the wafer W is unloaded from the wafer cassette 8 to the temporary placement means 12. Next, the transfer means 16 is operated to adsorb the frame F and transfer the wafer W to the liquid resin coating apparatus 30. The wafer W transferred to the liquid resin coating apparatus 30 is placed on the spinner table 32 as shown in FIG. 3(a) and is sucked and held by operating a suction means (not shown). If the wafer W is sucked and held by the spinner table 32, a predetermined process described below is started according to a predetermined control program stored in the control means 100. More specifically, the air piston 36 is operated to lower the wafer W together with the spinner table 32 as indicated by the arrow R5 in FIG. 3(b). At the same time, the lid 17c attached to the transfer means 17 described with reference to FIG. 1 is lowered in the direction indicated by the arrow R6 in FIG. 3(b) to close the opening 41a of the housing 41. In FIG. 3(b), for convenience of explanation, the suction pad 17a and the suction means 17b are omitted. Next, the spinner table 32 is gently rotated by the motor 35, the driving means 44b of the liquid resin supply nozzle 44 is operated, and its tip 44a is moved directly above the center of the wafer W, a predetermined amount of the liquid resin P is supplied, and the exhaust means 42 is operated together with the supply of the liquid resin P. When supplying the liquid resin P to the upper surface Wa of the wafer W, the spinner table 32 may be stopped and then rotated.

[0030] As described above, if the liquid resin P is supplied to the upper surface Wa of the wafer W, the motor 35 is operated at high speed to spread the liquid resin P over the entire surface of the wafer and dry it, and the spinner table 32 is rotated in the direction indicated by the arrow R7 at a predetermined rotational speed (for example, 3000 rpm). The rotation of the spinner table 32 is intermittently stopped, and while the spinner table 32 is stopped, the mist-like liquid resin P floating inside the housing 41 is sucked from the discharge port 421 by the exhaust means 42 and exhausted to the suction source 423 side through the discharge hose 422. The suction source 423 side is provided with an appropriate labyrinth-like gas-liquid separation mechanism (not shown) to recover the mist-like liquid resin P. The intermittent operation of the spinner table 32 by the motor 35, for example, repeats rotating for 30 seconds and then stopping for 5 seconds, and when the total rotation time of the spinner table 32 reaches 120 seconds, it is operated to completely stop. By performing such a liquid resin coating process, the liquid resin P supplied to the upper surface Wa of the wafer W is uniformly spread over the entire surface of the upper surface Wa of the wafer W and dried to form a protective film.

[0031] As described above, when the spinner table 32 is intermittently stopped and the mist-like liquid resin P floating inside the housing 41 is exhausted by the exhaust means 42, while the spinner table 32 is stopped, the mist-like liquid resin P floating in the housing 41 settles, and the mist-like liquid resin P is efficiently sucked from the discharge port 421 of the exhaust means 42 and exhausted to the suction source 423 side through the discharge hose 422. By elapsing a predetermined time after the completion of the liquid resin coating process performed in this way, a protective film in which the liquid resin P is solidified is formed on the upper surface Wa of the wafer W. Note that the length and ratio of the rotation time and the stop time, and the total rotation time in the intermittent operation of the spinner table 32 described above are appropriately changed according to the properties of the material selected as the liquid resin P, the size of the wafer, and the like. In addition, the "intermittently stopped" in the present invention is not limited to being stopped a plurality of times, and also includes the case of being stopped only once.

[0032] When the above-described resin film coating step is performed and a protective film is formed on the upper surface Wa of the wafer W, the wafer W is sucked by the transfer means 17 described with reference to FIG. 1 and transferred to the chuck table 18. The wafer W transferred to the chuck table 18 is placed on the chuck table 18 and sucked and held, and the frame F is fixed by the clamp 19. Next, the above-described feed means is operated to move the wafer W directly below the camera 22 of the alignment means 20, image the wafer W by the camera 22, and detect a predetermined laser processing region. Next, the feed means is operated to move the wafer W directly below the condenser 28 of the laser beam irradiation means 24, position the condensing point at a predetermined laser processing region on the upper surface Wa of the wafer W, and irradiate the laser beam while moving the wafer W in the X-axis direction in the drawing. The laser beam irradiated at this time has a wavelength that is absorbable by the wafer W and the protective film, and is set to an output capable of ablating the wafer W.

[0033] When the above-described laser beam is irradiated, the laser processing region to be divided in the wafer W is ablated together with the protective film to form a processing groove. The above-described laser beam irradiation means 24 and the above-described processing feed means are appropriately operated to feed the wafer W in the X-axis direction and the Y-axis direction to perform the above-described ablation processing and form processing grooves along all the laser processing regions in a predetermined direction. Next, the chuck table 18 is rotated 90 degrees to align the laser processing regions along the direction orthogonal to the direction in which the processing grooves were previously formed in the X-axis direction, and in the same manner as described above, ablation processing is performed along all the laser processing regions along the X-axis direction to form processing grooves. In the present embodiment, as described above, since the protective film is formed on the upper surface Wa of the wafer W with the liquid resin P, debris scattered during the ablation processing is prevented from adhering to the devices separated from the wafer W. As described above, processing grooves are formed along all the laser processing regions on the upper surface Wa of the wafer W, and the laser processing step is completed.

[0034] When the above-described laser processing step is completed, the liquid resin coating device 30 is used as a cleaning means, and a protective film removing step for removing the protective film on the wafer W is performed.

[0035] After performing the above-described laser processing step, the chuck table 18 holding the wafer W is positioned at the loading / unloading position shown in FIG. 1, and the wafer W is conveyed to the above-described liquid resin coating device 30 by the conveying means 17. The wafer W with the protective film is placed on the spinner table 32 positioned at the rising position in the housing 41 with the upper surface Wa side facing upward and sucked and held. Next, after lowering the spinner table 32, while closing the opening 41a of the housing 41 with the lid 17c attached to the conveying means 17, the motor 35 described with reference to FIGS. 2 and 3 is operated to rotate the spinner table 32 at a predetermined rotational speed (for example, 3000 rpm), and the cleaning liquid supply nozzle 46 is swung to spray a cleaning liquid (for example, water) from the tip 46a onto the upper surface Wa of the wafer W for a predetermined time. As a result, the protective film coated on the wafer W melts and is blown to the outer peripheral side, and is discharged into the housing 41 together with dirt components such as debris discharged by ablation processing. The melted and discharged protective film flows along the bottom surface 41b of the housing 41 together with the cleaning water, and is discharged through the discharge port 421 and the discharge hose 422 constituting the exhaust means 42, and is stored in a predetermined waste tank.

[0036] Next, the above-described cleaning liquid supply nozzle 46 is retracted to the storage position in the outer peripheral side direction in the housing 41, the air injection nozzle 45 is operated, the tip 45a of the air injection nozzle 45 is moved onto the wafer W, and air is injected toward the upper surface Wa side of the wafer W and swung in the horizontal direction (not shown). The spinner table 32 is rotated at a high speed (for example, 3000 rpm) to dry the upper surface Wa of the wafer W (drying step). Also in this case, by operating the above-described exhaust means 42, the cleaning liquid remaining in the housing 41 and the atomized cleaning liquid are discharged. It should be noted that it is also possible to intermittently stop the spinner table 32 when performing the above-described protective film removing step and when performing the drying step.

[0037] If the wafer W is dried as described above, the spinner table 32 is raised and the lid 17c is raised to open the opening 41a of the housing 41, and the above-described transfer means 16 is operated to carry out the wafer W from the spinner table 32 and transfer it to the temporary placement means 12. Next, the loading / unloading means 10 is used to store it in a predetermined position of the wafer cassette 8. Thus, the laser processing performed by the laser processing apparatus 2 is completed.

[0038] As described above, according to the liquid resin coating apparatus 30 of the present embodiment, after the liquid resin P is supplied to the upper surface Wa of the wafer W held by the spinner table 32, the motor 35 is operated to rotate the spinner table 32 so as to spread and dry the liquid resin P over the entire surface of the wafer W, and the rotation of the spinner table 32 is intermittently stopped, and the exhaust means 42 is controlled to exhaust the mist of the liquid resin P floating inside the housing 41. Therefore, when the liquid resin P is supplied to the upper surface Wa of the wafer W to form a protective film and the wafer W is carried out from the spinner table 32, even if the lid 17c that closes the housing 41 is opened, it is possible to prevent the mist-like liquid resin P from being lifted up from the opening 41a of the housing 41 and contaminating the periphery.

[0039] In the above-described embodiment, an example in which the liquid resin coating apparatus 30 of the present invention is disposed in the laser processing apparatus 2 is shown. However, the present invention is not limited to this, and it is also possible to dispose it in other processing apparatuses or to implement it as a liquid resin coating apparatus 30 independent of the processing apparatus.

Explanation of Reference Numerals

[0040] 2: Laser processing apparatus 4: Operation means 6: Display means 8: Wafer cassette 9: Cassette lifting means 10: Loading / unloading means 12: Temporary placement means 16: Transfer means 17: Transfer means 17a: Suction pad 17b: Suction means 17c: Cover 18: Chuck table 19: Clamp 20: Alignment means 22: Camera 24: Laser beam irradiation means 26: Casing 28: Condenser 30: Liquid resin coating device 31: Table mechanism 32: Spinner table 321: Suction chuck 322: Frame part 34: Shaft part 35: Motor 36: Air piston 36a: Rod 40: Cover part 41: Housing 41a: Opening 41b: Bottom surface 42: Exhaust means 421: Exhaust port 422: Exhaust hose 423: Suction source 44: Liquid resin supply nozzle 44a: Tip part 45: Air injection nozzle 45a: Tip part 46: Cleaning liquid supply nozzle 46a: Tip part P: Liquid resin W: Wafer Wa: Upper surface

Claims

【Claim 1】 A liquid resin coating apparatus for coating a liquid resin on the upper surface of a wafer, comprising: a spinner table for holding and rotating the wafer; a liquid resin supply nozzle for supplying the liquid resin to the upper surface of the wafer held on the spinner table; a motor for rotating the spinner table; a housing having an opening at the upper part for allowing the loading and unloading of the wafer, surrounding the spinner table, and having an exhaust means at the lower part; a lid for closing the opening of the housing; and a control means, wherein the control means controls to spread the liquid resin on the upper surface of the wafer by the rotation of the spinner table driven by the motor after the liquid resin is supplied to the upper surface of the wafer held on the spinner table, and to intermittently stop the rotation of the spinner table and exhaust the mist of the liquid resin floating inside the housing by the exhaust means.

Images