Protective film formation method

Abstract

To provide a protective film formation method capable of forming a uniform-thickness protective film regardless of the shape of a workpiece or external environment.SOLUTION: A protective film formation method for forming a protective film on a workpiece includes: a holding step (201) of holding the workpiece on a holding table; a first protective film formation step (202) in which a predetermined amount of liquid resin is dropped onto the upper surface of the workpiece held on the holding table, and the holding table is rotated to spread the liquid resin, thereby forming a first protective film covering the upper surface of the workpiece; and a second protective film formation step (203), performed after the first protective film formation step (202), in which the liquid resin is atomized, and while an air curtain is formed surrounding the atomized liquid resin, the atomized liquid resin is supplied to the upper surface of the workpiece held on the holding table, thereby forming a second protective film covering the entire upper surface of the workpiece.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In the manufacturing process of semiconductor devices, a method has been proposed in which a workpiece (wafer) with devices formed on its surface is divided into chip sizes by irradiating the workpiece with a laser beam along a planned dividing line (see Patent Document 1). This type of processing method generates processing waste called debris, which may scatter and re-adhere to the workpiece, thereby contaminating the workpiece.

[0003] To solve this problem, a method has been disclosed in which a water-soluble protective film is formed on the surface of a workpiece, debris generated during processing is attached to the protective film, and the protective film and debris are simultaneously washed away (see Patent Document 2).A common method for applying a protective film is to supply a water-soluble liquid resin to the surface of the workpiece on the spinner table while the spinner table holding the workpiece is rotating at high speed, and then cover the surface of the workpiece as the liquid resin moves due to centrifugal force, and then dry it to form a protective film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-305420 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-140311 [Patent Document 3] Japanese Patent Application Publication No. 6-210236 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the workpiece has bumps such as steps or electrodes, it is difficult to apply the liquid resin evenly to the workpiece surface, and there is a possibility that some parts will not be covered with a protective film. To address this issue, a method was adopted in which the liquid resin is atomized by ultrasonic waves and applied to the workpiece (see Patent Document 3), but the atomized liquid resin sways due to disturbances such as static electricity, which causes a problem that the resin cannot be applied evenly to the workpiece.

[0006] The present invention has been made in consideration of these problems, and its object is to provide a protective film forming method that can form a protective film of uniform thickness regardless of the shape of the workpiece or the external environment. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the protective film forming method of the present invention is a protective film forming method for forming a protective film on a workpiece, and is characterized by including: a holding step of holding the workpiece on a holding table; a first protective film forming step of dripping a predetermined amount of liquid resin onto the upper surface of the workpiece held on the holding table and rotating the holding table to spread the liquid resin and form a first protective film covering the upper surface of the workpiece; and a second protective film forming step of, after the first protective film forming step, atomizing the liquid resin and forming an air curtain surrounding the atomized liquid resin, and supplying the atomized liquid resin to the upper surface of the workpiece held on the holding table, thereby forming a second protective film covering the entire upper surface of the workpiece. [Effects of the Invention]

[0008] The present invention can form a protective film of uniform thickness regardless of the shape of the workpiece or the external environment. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view, partially in cross section, showing a schematic configuration example of a protective film forming apparatus according to an embodiment. [Figure 2]FIG. 2 is a perspective view of a workpiece to be processed by the protective film forming apparatus shown in FIG. [Figure 3] 3 is a side view, partly in section, showing an example of the configuration of the vibration surface of the atomization unit shown in FIG. [Figure 4] 4 is a perspective view showing, in partial cross section, an example of the configuration of the main part of the air curtain forming unit shown in FIG. [Figure 5] FIG. 5 is a flowchart showing the flow of the protective film forming method according to the embodiment. [Figure 6] FIG. 6 is a side view, partially in cross section, schematically illustrating an example of the first protective film forming step shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view showing a main part of the workpiece in one state after the first protective film forming step shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing a main part of the workpiece in one state after the second protective film forming step shown in FIG. [Figure 9] FIG. 9 is a side view, partly in section, showing an example of the configuration of the vibration surface of the atomization unit of the first modified example. [Figure 10] FIG. 10 is a side view, partly in section, showing an example of the configuration of the vibration surface of the atomization unit of the second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0011] [Embodiment] First, a protective film forming apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view, partially in cross section, showing a schematic configuration example of the protective film forming apparatus 1 according to the embodiment. FIG. 2 is a perspective view of a workpiece 100 to be processed by the protective film forming apparatus 1 shown in FIG. 1. FIG. 3 is a side view, partially in cross section, showing a configuration example of the vibration surface 33 of the atomization unit 30 shown in FIG. 1. FIG. 4 is a perspective view, partially in cross section, showing a configuration example of a main part of the air curtain forming unit 50 shown in FIG. 1.

[0012] 1, the protective film forming apparatus 1 of the embodiment includes a holding table 10, a coating unit 20, a cleaning mechanism 60, and a liquid resin dripping unit 70 (see FIG. 6 described later). Note that in the drawings accompanying this specification, the coating unit 20 is depicted as being exaggerated and relatively larger than the other components of the protective film forming apparatus 1 for the sake of explanation, but in reality, it is sized to be movable between an operating position located above the holding table 10 and a retracted position spaced apart from above the holding table 10.

[0013] The protective film forming apparatus 1 is an apparatus that forms a protective film 120 (see FIG. 8) on the workpiece 100 held on a holding table 10 by applying atomized liquid resin 41 from an application unit 20 to the workpiece 100. The workpiece 100 is a wafer such as a disk-shaped semiconductor wafer or optical device wafer, with a substrate 101 made of silicon (Si), sapphire (Al2O3), gallium arsenide (GaAs), silicon carbide (SiC), or the like.

[0014] 2, the workpiece 100 has a plurality of planned division lines 103 set in a grid pattern on a surface 102 of a substrate 101, and devices 104 formed in areas partitioned by the planned division lines 103. The devices 104 are, for example, integrated circuits such as ICs (Integrated Circuits) or LSIs (Large Scale Integration), image sensors such as CCDs (Charge Coupled Devices) or CMOSs ​​(Complementary Metal Oxide Semiconductors), etc. The surface of the workpiece 100 opposite the surface 102 on which the devices 104 are formed is referred to as a back surface 105.

[0015] In the embodiment, the workpiece 100 has a plurality of electrode bumps 106 mounted on the surface of the device 104, forming an uneven surface 102. The electrode bumps 106 have a height of approximately 200 μm and protrude from the surface of the device 104. The device 104 has an uneven structure due to the electrode bumps 106 mounted on the surface 102. The workpiece 100 is divided into individual devices 104 along the planned division lines 103 and singulated into chips 107. Note that although the chips 107 are square in shape in FIG. 2 , they may also be rectangular in shape. Furthermore, in the embodiment, the workpiece 100 has electrode bumps 106 protruding from the surface of the device 104, forming an uneven surface 102. However, the present invention is not limited to the mounting of electrode bumps 106, and may have unevenness formed on the surface 102 side.

[0016] In this embodiment, the workpiece 100 is attached to an annular frame 110 and supported within an opening of the frame 110 with adhesive tape 111 having a diameter larger than the outer diameter of the workpiece 100 attached to the back surface 105 .

[0017] The holding table 10 holds the workpiece 100 on a holding surface 11. The holding surface 11 is disk-shaped and made of porous ceramic or the like. In this embodiment, the holding surface 11 is a flat surface parallel to the horizontal direction. The holding surface 11 is connected to a vacuum suction source, for example, via a vacuum suction path. The holding table 10 holds the workpiece 100 placed on the holding surface 11 by suction. A plurality of clamp members 12 are arranged around the holding table 10 to clamp an annular frame 110 that supports the workpiece 100. The holding table 10 can rotate around a vertical axis by a rotation unit 13 that supports the holding table 10 from below.

[0018] The coating unit 20 is a unit that applies atomized liquid resin 41 to the upper surface (surface 102) of the workpiece 100 held on the holding table 10 to form a protective film 120 (second protective film 122, see FIG. 8 ). The coating unit 20 is movable by a moving unit (not shown) between an operating position located above the holding table 10 and a retracted position spaced apart from above the holding surface 11 of the holding table 10. The coating unit 20 includes an atomization unit 30, a liquid resin supply unit 40, and an air curtain forming unit 50.

[0019] The atomization unit 30 atomizes the liquid resin 41 supplied from the liquid resin supply unit 40 (described later). The atomization unit 30 includes an ultrasonic vibrator 31. The ultrasonic vibrator 31 generates ultrasonic waves by vibrating at a predetermined amplitude and frequency. In this embodiment, the ultrasonic vibrator 31 vibrates, for example, with an amplitude of 30 μm, an output of 20 W, and a frequency of 52 kHz. The ultrasonic vibrator 31 includes, for example, a piezoelectric element that expands and contracts when electrically charged.

[0020] The ultrasonic vibrator 31 includes a horn 32 that amplifies vibrations. Liquid resin 41 is supplied to the horn 32 from a liquid resin supply unit 40, which will be described later. The horn 32 has a vibration surface 33 that faces the workpiece 100 held on the holding table 10. In this embodiment, the distance between the vibration surface 33 and the surface 102 of the workpiece 100 is 10 mm or more and 20 mm or less.

[0021] As shown in Fig. 3, the ultrasonic vibrator 31 further includes a diaphragm 34. The diaphragm 34 is fixed to the vibration surface 33 side of the horn 32 by screws 35 or the like. That is, the diaphragm 34 vibrates together with the horn 32. In this embodiment, the thickness of the diaphragm 34 is less than 100 µm. The diaphragm 34 is disposed so as to have a minute gap 36 between it and the vibration surface 33 of the horn 32.

[0022] In this embodiment, the distance (vertical distance) in the gap 36 between the vibration surface 33 and the vibration plate 34 is less than 100 μm. Liquid resin 41 is supplied to the gap 36 from a liquid resin supply unit 40, which will be described later. The atomization unit 30 can atomize the liquid resin 41 by vibrating the ultrasonic vibrator 31 while the liquid resin 41 is being supplied from the liquid resin supply unit 40.

[0023] 1, the ultrasonic transducer 31 further includes a heat dissipation unit 37. The heat dissipation unit 37 dissipates heat from the ultrasonic transducer 31 that is heated by vibration. The heat dissipation unit 37 includes, for example, a heat sink. The heat sink can be cooled, for example, by water cooling.

[0024] The liquid resin supply unit 40 is a unit that supplies the liquid resin 41 to the atomization unit 30. In this embodiment, the liquid resin supply unit 40 includes a liquid resin supply nozzle 42 that supplies the liquid resin 41 to the horn 32. The liquid resin supply nozzle 42 preferably supplies the liquid resin 41 to the gap 36 (see FIG. 3 ). In this embodiment, a supply port 43 of the liquid resin supply nozzle 42 is located inside a gas supply nozzle 52 of the air curtain forming unit 50, which will be described later. In this embodiment, the liquid resin supply unit 40 supplies the liquid resin 41 at a supply rate of 0.2 mL / min to 1 mL / min. In this embodiment, the viscosity of the liquid resin 41 is 52 cP. The viscosity of the liquid resin 41 is not limited to this embodiment and may be changed as appropriate as long as the liquid resin can be atomized by the atomization unit 30.

[0025] The air curtain forming unit 50 is a unit that supplies gas 51 toward the workpiece 100 and forms an air curtain 54 that surrounds the sides of the area between the horn 32 and the workpiece 100 until the atomized liquid resin 41 is applied to the workpiece 100. The air curtain forming unit 50 is equipped with a gas supply nozzle 52.

[0026] The gas supply nozzle 52 ejects gas 51 toward the workpiece 100. The gas supply nozzle 52 is arranged to surround the ultrasonic vibrator 31. As shown in FIG. 4, in this embodiment, the gas supply nozzle 52 has a slit shape with an ejection port 53 opening downward, and is arranged in a ring shape surrounding the side of the ultrasonic vibrator 31 (see FIG. 1). The air curtain forming unit 50 forms an air curtain 54 that surrounds the atomized liquid resin 41 by the flow of gas 51 ejected from the ejection port 53 of the gas supply nozzle 52 toward the workpiece 100. In this embodiment, the ejection port 53 is arranged in a ring shape, so the air curtain 54 is formed in a roughly cylindrical shape.

[0027] In the embodiment, the flow of gas 51 forming air curtain 54 is aligned with the direction in which atomized liquid resin 41 flows toward workpiece 100. Here, "aligned" includes being parallel and forming a small angle with each other. Also, in the embodiment, the direction of the flow of gas 51 forming air curtain 54 is the same as the direction in which atomized liquid resin 41 flows toward workpiece 100.

[0028] The gas 51 supplied from the gas supply nozzle 52 is preferably hot air or dry air at a temperature of 25°C to 80°C, or a mixture of hot air and dry air. As shown in FIG. 1, in this embodiment, the air curtain forming unit 50 further includes a heat source 55. The heat source 55 heats the gas 51 supplied from the gas supply nozzle 52. This can promote drying of the liquid resin 41 applied to the surface 102 of the workpiece 100. In this embodiment, the air curtain forming unit 50 supplies the gas 51 at a flow rate of 70 mL / min.

[0029] Protective film forming device 1 supplies liquid resin 41 from liquid resin supply nozzle 42 to horn 32 while ultrasonic vibrator 31 is vibrating, thereby applying atomized liquid resin 41 to workpiece 100. At this time, air curtain 54 formed by gas 51 ejected from gas supply nozzle 52 surrounds atomized liquid resin 41, making it possible to apply atomized liquid resin 41 to workpiece 100 while suppressing the effects of external disturbances.

[0030] The protective film forming apparatus 1 applies liquid resin 41 to the entire surface 102 of the workpiece 100 by moving the coating unit 20 and the holding table 10 relatively to each other, thereby forming a protective film 120 (second protective film 122, see FIG. 8 ) that covers the surface 102 of the workpiece 100. The protective film forming apparatus 1 moves the coating unit 20 and the holding table 10 relatively in a spiral pattern, for example. The protective film forming apparatus 1 also repeatedly applies the resin, for example, five passes, until the irregularities (electrode bumps 106) on the surface 102 of the workpiece 100 are covered.

[0031] Cleaning mechanism 60 is a mechanism for removing liquid resin 41 that has adhered to the tip of horn 32. As shown in Fig. 1, cleaning mechanism 60 includes, for example, a cleaning liquid supply nozzle 62 that supplies cleaning liquid 61 to vibration surface 33 of horn 32, and a liquid tank 64 filled with cleaning liquid 61 in which vibration surface 33 can be immersed. In this embodiment, supply port 63 of cleaning liquid supply nozzle 62 is located inside gas supply nozzle 52 of air curtain forming unit 50.

[0032] As shown in FIG. 6 , which will be described later, the liquid resin dripping unit 70 drips a predetermined amount of liquid resin 71 onto the upper surface (surface 102) of the workpiece 100 held on the holding table 10. The liquid resin dripping unit 70 includes a liquid resin dripping nozzle 72. The liquid resin 71 is the same as the liquid resin 41 supplied by the liquid resin supply unit 40 of the coating unit 20.

[0033] The liquid resin dripping nozzle 72 drips a predetermined amount of liquid resin 71 onto the upper surface (surface 102) of the workpiece 100 held on the holding table 10. The liquid resin dripping nozzle 72 is movable by a moving unit (not shown) between a dripping position where a supply port 73 is directed toward the workpiece 100 held on the holding table 10 and a retracted position away from above the holding surface 11 of the holding table 10.

[0034] The protective film forming device 1 drips a predetermined amount of liquid resin 71 onto the surface 102 of the workpiece 100 using the liquid resin dripping unit 70, and by rotating the holding table 10, the liquid resin 71 is spread to form a first protective film 121 (see Figure 7) that covers the surface 102 of the workpiece 100.

[0035] Next, a protective film forming method according to an embodiment of the present invention will be described with reference to the drawings. Fig. 5 is a flow chart showing the flow of the protective film forming method according to the embodiment. The protective film forming method according to the embodiment includes a holding step 201, a first protective film forming step 202, and a second protective film forming step 203.

[0036] (Holding step 201) The holding step 201 is a step of holding the workpiece 100 on the holding table 10 shown in Fig. 1. In the holding step 201, first, the back surface 105 of the workpiece 100 is attached to an adhesive tape 111 that is attached to an annular frame 110 and has a diameter larger than the outer diameter of the workpiece 100, thereby supporting the workpiece 100 within the opening of the frame 110. Next, the back surface 105 of the workpiece 100 is suction-held to the holding surface 11 of the holding table 10 via the adhesive tape 111, and the frame 110 is clamped by the clamp member 12.

[0037] (First protective film formation step 202) Fig. 6 is a side view, partially in cross section, showing a schematic example of the first protective film forming step 202 shown in Fig. 5. Fig. 7 is a cross-sectional view showing a main part of the workpiece 100 in one state after the first protective film forming step 202 shown in Fig. 5. The first protective film forming step 202 is a step of forming a first protective film 121 that covers the upper surface (surface 102) of the workpiece 100.

[0038] In the first protective film forming step 202, first, a moving unit (not shown) moves the liquid resin dripping unit 70 to a dripping position where the supply port 73 is directed toward the workpiece 100 held on the holding table 10. Next, a predetermined amount of liquid resin 71 is dripped from the liquid resin dripping nozzle 72 onto the upper surface (surface 102) of the workpiece 100 held on the holding table 10, and the holding table 10 is rotated around a vertical axis. As a result, the liquid resin 71 dripped onto the surface 102 of the workpiece 100 is diffused toward the periphery of the workpiece 100 by centrifugal force.

[0039] 7, the diffused liquid resin 71 covers the surface 102 of the workpiece 100 as a first protective film 121. The first protective film 121 exposes the protruding portions of the unevenness formed by the plurality of electrode bumps 106 mounted on the surface 102 of the workpiece 100.

[0040] (Second protective film formation step 203) 8 is a cross-sectional view showing a main part of the workpiece 100 in one state after the second protective film forming step 203 shown in FIG. The second protective film forming step 203 is a step of forming a second protective film 122 that covers the entire upper surface (surface 102) of the workpiece 100. The second protective film forming step 203 is performed after the first protective film forming step 202.

[0041] In the second protective film forming step 203, first, a moving unit (not shown) moves the coating unit 20 to an operating position above the holding table 10 (see FIG. 1). Next, the air curtain forming unit 50 supplies gas 51 from the gas supply nozzle 52 toward the workpiece 100. This forms an air curtain 54 that surrounds the sides of the area between the horn 32 and the workpiece 100. Next, ultrasonic waves are generated by vibrating the ultrasonic vibrator 31 of the atomizing unit 30. The vibrations of the ultrasonic vibrator 31 are transmitted to the horn 32 and amplified.

[0042] In the second protective film forming step 203, with the air curtain 54 formed and the ultrasonic vibrator 31 vibrating, the liquid resin supply unit 40 supplies the liquid resin 41 from the liquid resin supply nozzle 42 to the horn 32. More specifically, the liquid resin 41 is supplied to the gap 36 between the vibration surface 33 and the vibration plate 34 of the horn 32. The liquid resin 41 is atomized by the ultrasonic waves generated by the vibration of the ultrasonic vibrator 31.

[0043] 1, liquid resin supply nozzle 42 is provided inside gas supply nozzle 52. That is, atomized liquid resin 41 descends in an area surrounded by air curtain 54 and is applied to the upper surface (surface 102) of workpiece 100. That is, in second protective film formation step 203, liquid resin 41 is atomized, and in a state in which air curtain 54 surrounding atomized liquid resin 41 is formed, atomized liquid resin 41 is supplied to surface 102 of workpiece 100 held on holding table 10.

[0044] 8, the atomized liquid resin 41 supplied to the surface 102 of the workpiece 100 forms a second protective film 122 that covers the surface 102 of the workpiece 100 together with the electrode bumps 106. The application unit 20 can apply the atomized liquid resin 41 to the workpiece 100 while suppressing the effects of external disturbances by using the air curtain 54 to surround the atomized liquid resin 41, thereby making it possible to make the thickness of the second protective film 122 that covers the electrode bumps 106 uniform.

[0045] As described above, the protective film forming apparatus 1 and protective film forming method of the embodiment form an air curtain 54 that surrounds an area until the atomized liquid resin 41 is applied to the surface 102 of the workpiece 100. For example, even a slight air current generated when the application unit 20 scans the top of the workpiece 100 or when the holding table 10 rotates or translates causes fluctuations in the atomized liquid resin 41, making it difficult to apply the atomized liquid resin 41 to the desired area of ​​the workpiece 100. In the protective film forming apparatus 1 of the embodiment, the air curtain 54 suppresses the influence of external disturbances on the atomized liquid resin 41, making it possible to uniformly apply the protective film 120 to the workpiece 100.

[0046] The present invention is not limited to the above-described embodiment. In other words, various modifications can be made without departing from the gist of the present invention. For example, in the embodiment, the gas supply nozzle 52 has a slit shape with the ejection port 53 opening in a circular ring shape on the lower side, but in the present invention, the gas supply nozzle 52 may have a hole shape with multiple holes arranged in a circular ring shape.

[0047] Furthermore, the protective film forming apparatus 1 may be provided with a mechanism for heating the holding table 10 or a mechanism for irradiating the upper surface (surface 102) of the workpiece 100 with a halogen light in order to promote drying of the applied liquid resin 41. Furthermore, ethanol may be mixed into the supplied liquid resin 41 to improve drying properties.

[0048] Furthermore, the vibration surface 33 of the horn 32 of the atomization unit 30 is not limited to the configuration of the embodiment, and in the present invention, it may be configured as shown in Figs. 9 and 10, for example.

[0049] FIG. 9 is a side view, partially in cross section, showing an example of the configuration of the vibration surface 33 of the atomization unit 30-1 of the first modified example. The atomization unit 30-1 of the first modified example differs from the atomization unit 30 of the embodiment in the configuration of the vibration plate 34-1 and the direction in which the screws 35-1 are fastened. That is, the vibration plate 34 of the embodiment is shaped like a lid that covers the vibration surface 33, which is the underside of the horn 32, and the side surface near the bottom end, and is fastened from the side by screws 35. Meanwhile, the vibration plate 34-1 of the first modified example is flat and fastened from below by the screws 35-1 via a spacer 38-1. The gap 36-1 between the vibration plate 34-1 and the vibration surface 33 of the first modified example is formed by the spacer 38-1.

[0050] FIG. 10 is a side view, partially in cross section, showing an example of the configuration of the vibration surface 33 of the atomization unit 30-2 of the second modified example. The atomization unit 30-2 of the second modified example differs from the atomization unit 30 of the embodiment in that the horn 32 and the vibration plate 34-2 are integrally formed. That is, while the vibration plate 34 of the embodiment is provided separately from the horn 32 and fixed to the horn 32 with screws 35, the vibration plate 34-2 of the second modified example is provided integrally with the horn 32 via a connecting portion 39-2. The connecting portion 39-2 extends downward from the periphery of the vibration surface 33 of the horn 32 and connects to the upper surface of the flat vibration plate 34-2. The gap 36-2 between the vibration plate 34-2 and the vibration surface 33 of the second modified example is formed by the connecting portion 39-2, which functions as a spacer. [Explanation of symbols]

[0051] 1 Protective film forming device 10 Holding table 20 Coating unit 30, 30-1, 30-2 atomization unit 31 Ultrasonic vibrator 32 Horn 33 Vibration Surface 34, 34-1, 34-2 diaphragm 36, 36-1, 36-2 gap 40 Liquid resin supply unit 41 Liquid Resin 42 Liquid resin supply nozzle 43 Supply port 50 Air curtain forming unit 51 Gas 52 Gas supply nozzle 53 spout 54 Air Curtain 55 Heat source 60 Cleaning mechanism 70 Liquid resin dripping unit 71 Liquid Resin 72 Liquid resin dripping nozzle 73 Supply port 100 Workpiece 102 Surface (Top surface) 120 Protective film 121 First Protective Film 122 Second Protective Film

Claims

[Claim 1] A protective film forming method for forming a protective film on a workpiece, comprising: a holding step of holding the workpiece on a holding table; a first protective film forming step of dropping a predetermined amount of liquid resin onto the upper surface of the workpiece held on the holding table and rotating the holding table to spread the liquid resin and form a first protective film covering the upper surface of the workpiece; a second protective film forming step of atomizing the liquid resin after the first protective film forming step, and supplying the atomized liquid resin to the upper surface of the workpiece held on the holding table in a state in which an air curtain surrounding the atomized liquid resin is formed, thereby forming a second protective film that covers the entire upper surface of the workpiece; A method for forming a protective film, comprising:

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