Wafer dividing method

Abstract

To prevent cutting chips from remaining on a wafer without increasing production cost.SOLUTION: After the kerfs 117 are formed, the wafer 100 with the first protective films 115 and the second protective films 116 formed thereon is cleaned with a cleaning liquid. Since the first protective film 115 reacts with the cleaning liquid and its adhesive force decreases, the first protective film 115 and the second protective film 116 on the upper layer thereof can be easily peeled off from the wafer 100. Therefore, the kerfs 117 can be cleaned well, and adhesion of cutting dust to the chips 105 can be prevented. In addition, since the second protective film 116 does not react with the cleaning liquid, the amount of the cleaning liquid required for peeling off the first protective film 115 and the second protective film 116 can be reduced as compared with a configuration in which both the first protective film 115 and the second protective film 116 react with the cleaning liquid. Accordingly, the adhesion of the cutting dust to the chips 105 can be prevented without increasing the production cost.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for dividing a wafer. [Background technology]

[0002] As disclosed in Patent Document 1, in the cutting process in which a wafer having multiple devices and streets formed thereon is cut along the streets with a cutting blade to create chips, a chemical solution is supplied to the processing point to prevent cutting debris from adhering to the chips. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-175130 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-213969 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the cutting process described above requires a large amount of chemicals, which increases the cost of treating the chemicals.

[0005] Therefore, an object of the present invention is to prevent cutting debris from adhering to a tip without increasing production costs. [Means for solving the problem]

[0006] The wafer dividing method of the present invention (the present dividing method) is a wafer dividing method in which a wafer held on a chuck table and having a plurality of devices and streets formed on its surface is cut along the streets by a cutting blade, and includes a first protective film forming step of forming a first protective film by applying a first liquid resin to the entire surface of the wafer, a second protective film forming step of forming a second protective film on the first protective film by applying a second liquid resin to the entire surface of the first protective film, and a second protective film forming step of forming a second protective film on the first protective film by applying a second liquid resin to the entire surface of the first protective film. The method includes an alignment step for detecting the street, a kerf forming step for cutting the cutting blade along the street while supplying cutting water from the second protective film side to form a kerf in the second protective film, the first protective film, and the wafer, and a cleaning step for cleaning the kerf while supplying an alkaline or acidic cleaning solution that does not react with the second protective film but swells or dissolves the first protective film from the second protective film side of the kerf to reduce the adhesive strength of the first protective film, thereby peeling the first protective film and the second protective film from the surface of the wafer. [Effects of the Invention]

[0007] In this dividing method, the wafer on which the first and second protective films are formed is washed with a cleaning solution in a cleaning process after the formation of the kerf. The first protective film swells or dissolves in the cleaning solution, reducing its adhesive strength. This allows the first protective film and the second protective film thereon to be easily peeled off from the wafer in the cleaning process. This allows the kerf to be cleaned well, preventing cutting debris from adhering to the chips obtained by dividing the wafer along the kerf. Furthermore, because the second protective film does not react with the cleaning liquid, the amount of cleaning liquid required to peel off the first and second protective films can be reduced compared to a configuration in which both the first and second protective films react with the cleaning liquid, making it possible to prevent cutting debris from adhering to the chip without increasing production costs. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing the configuration of a cutting device. [Figure 2] FIG. 10 is a cross-sectional view showing a first protective film forming step. [Figure 3] FIG. 10 is a cross-sectional view showing a second protective film forming step. [Figure 4] FIG. 4 is a cross-sectional view showing a kerf forming step. [Figure 5] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The cutting device 1 shown in Fig. 1 is a device that cuts a wafer 100. The wafer 100 is an example of a workpiece and has a roughly circular shape. Lattice-shaped streets 102 are formed on the surface of the wafer 100. Devices 103 are formed in each area defined by the streets 102.

[0010] A dicing tape 113 is attached to the back surface of the wafer 100. A ring frame 111 is attached to the outer periphery of the dicing tape 113. In this manner, the wafer 100 is processed in the cutting device 1 in the state of a work set 110 in which the ring frame 111 and the wafer 100 are integrated with the dicing tape 113 attached thereto. The work set 110 is housed in a cassette 11 and carried into the cutting device 1.

[0011] The cutting device 1 is what is called a dual dicer. The cutting device 1 is equipped with a base 2, and a rectangular opening 3 extending in the X-axis direction is formed in the center of the base 2 in the Y-axis direction. Furthermore, on the -Y direction side of this opening 3, a rectangular plate-shaped cassette stage 10 is arranged that moves up and down in the vertical direction (Z-axis direction).

[0012] On this cassette stage 10, a cassette 11 that accommodates the above-mentioned work set 110 is placed.

[0013] A cassette lifting mechanism 50 is disposed inside the base 2 below the cassette stage 10. The cassette lifting mechanism 50 is a mechanism for raising and lowering the cassette stage 10 together with the cassette 11 along the Z-axis direction. The cassette lifting mechanism 50 includes a pair of guide rails 51 extending in the Z-axis direction, a ball screw 52 disposed between the guide rails 51, and a motor 53 that rotates and drives the ball screw 52. The pair of guide rails 51 guide the cassette stage 10 as it moves up and down. The upper end of the ball screw 52 is threadedly engaged with a nut member (not shown) attached to the cassette stage 10.

[0014] In the cassette lifting mechanism 50 having such a configuration, the motor 53 rotates the ball screw 52, ​​thereby moving the cassette stage 10 up and down along the Z-axis direction.

[0015] On the +Y direction side of the cassette stage 10, there is disposed a pull-out mechanism 30 that pulls out one work set 110 in the +Y direction from the cassette 11. The pull-out mechanism 30 includes a ball screw 31 arranged along the Y-axis direction, a guide rail 32 arranged parallel to the ball screw 31, an L-shaped pull-out arm 33 that moves in the Y-axis direction along the guide rail 32, a motor 34 that rotates the ball screw 31, and a bearing 35 for the ball screw 31.

[0016] The drawer arm 33 has a vertical portion 33a and a horizontal portion 33b. The vertical portion 33a is slidably inserted and supported on the guide rail 32. A ball screw 31 is threadedly inserted and passed through the vertical portion 33a. The horizontal portion 33b bends from the upper end of the vertical portion 33a and extends in the -X direction. A gripping portion 36 for gripping the work set 110 in the cassette 11 is provided at the tip of the horizontal portion 33b.

[0017] In the pull-out mechanism 30, the motor 34 rotates the ball screw 31, causing the pull-out arm 33 having the gripper 36 to move along the Y-axis direction. This allows the gripper 36 to grip the work set 110 and pull it out from the cassette 11 or store it back into the cassette 11.

[0018] A temporary placement mechanism 40 is disposed above the opening 3 in the base 2. The temporary placement mechanism 40 is a mechanism for temporarily placing the work set 110 drawn out from the cassette 11 by the drawer mechanism 30. The temporary placement mechanism 40 includes a pair of frame guides (rails) 41 that are bent into an L shape, and a spacing adjustment mechanism 42 that adjusts the spacing between these frame guides 41. The work set 110 drawn out from the cassette 11 is temporarily placed on the pair of frame guides 41. The spacing adjustment mechanism 42 can move the pair of frame guides 41 toward or away from each other along the X-axis direction to match the size of the work set 110.

[0019] The chuck table 20 is disposed on the +X direction side of the temporary placement mechanism 40. The chuck table 20 is a disk-shaped member that holds the work set 110. The chuck table 20 has a holding surface 22 that suction-holds the wafer 100. In the chuck table 20, the holding surface 22 is connected to a suction source (not shown), so that the holding surface 22 can suction-hold the wafer 100 on the work set 110 via the dicing tape 113.

[0020] A plurality of clamps 25 for holding the ring frame 111 of the work set 110 are provided around the chuck table 20. The clamps 25 are arranged at equal angular intervals on the outer periphery of the holding surface 22 (four clamps in this embodiment).

[0021] The chuck table 20 is rotated by a rotation mechanism (not shown) disposed below it about a rotation axis that passes through the center of the holding surface 22 and extends in the Z-axis direction. Furthermore, the chuck table 20 can be moved along the X-axis direction by an X-axis direction movement mechanism 37 (see FIG. 4) disposed below it.

[0022] A first transfer device 60 is disposed above the chuck table 20. The first transfer device 60 includes a first frame holding unit 61 that holds the ring frame 111 of the work set 110, a first Z-axis movement mechanism 62 that moves the first frame holding unit 61 in the Z-axis direction, and a first Y-axis lifting mechanism 63 that raises and lowers the first frame holding unit 61 in the Y-axis direction.

[0023] The first transfer device 60 holds the work set 110 temporarily placed on the frame guide 41 of the temporary placement mechanism 40 and transfers it to the holding surface 22 of the chuck table 20 or the spinner table 56 of the spinner mechanism 55 .

[0024] A gate-type column 6 is erected on the -X direction side of the base 2 so as to straddle the opening 3. A movement mechanism 13 that moves a first cutting mechanism 18 and a second cutting mechanism 19 is provided on the front surface (the surface on the +X direction side) of the gate-type column 6. The movement mechanism 13 indexes the first cutting mechanism 18 and the second cutting mechanism 19 in the Y axis direction and cuts them in the Z axis direction.

[0025] The moving mechanism 13 includes a first lifting mechanism 16 that raises and lowers the first cutting mechanism 18 on the +Y direction side, a second lifting mechanism 17 that raises and lowers the second cutting mechanism 19 on the -Y direction side, and a Y-axis moving mechanism 12 that moves the first cutting mechanism 18 and the second cutting mechanism 19 in the Y-axis direction.

[0026] The Y-axis direction moving mechanism 12 is disposed in front of the gantry column 6. The Y-axis direction moving mechanism 12 moves a first lifting mechanism 16 supporting a first cutting mechanism 18 and a second lifting mechanism 17 supporting a second cutting mechanism 19 back and forth along the Y-axis direction.

[0027] The Y-axis direction moving mechanism 12 includes a pair of guide rails 121 extending in the Y-axis direction, a first Y-axis table 123 and a second Y-axis table 125 attached to the guide rails 121, a first ball screw 120 and a second ball screw 122 extending parallel to the guide rails 121, a first motor 124 that rotates the first ball screw 120, and a second motor (not shown) that rotates the second ball screw 122.

[0028] A pair of guide rails 121 are arranged in front of the gate-type column 6, parallel to the Y-axis direction. A first Y-axis table 123 and a second Y-axis table 125 are installed on the pair of guide rails 121 so as to be slidable along these guide rails 121. A first lifting mechanism 16 and a first cutting mechanism 18 are attached to the first Y-axis table 123. A second lifting mechanism 17 and a second cutting mechanism 19 are attached to the second Y-axis table 125.

[0029] The first ball screw 120 is threadedly engaged with a nut portion (not shown) provided on the first Y-axis table 123. The first motor 124 is connected to one end of the first ball screw 120 and rotates the first ball screw 120. As the first ball screw 120 is rotated, the first Y-axis table 123, the first lifting mechanism 16, and the first cutting mechanism 18 move in the Y-axis direction along the guide rail 121.

[0030] Similarly, the second ball screw 122 is threaded into a nut portion (not shown) of the second Y-axis table 125, and is rotationally driven by a second motor connected to one end of the nut portion. This causes the second Y-axis table 125, the second lifting mechanism 17, and the second cutting mechanism 19 to move in the Y-axis direction along the guide rail 121.

[0031] The first lifting mechanism 16 reciprocates the first cutting mechanism 18 in the Z-axis direction. The first lifting mechanism 16 includes a pair of guide rails 161 extending in the Z-axis direction, a support member 163 arranged on the guide rails 161, a ball screw 160 extending parallel to the guide rails 161, and a motor 162 that rotates the ball screw 160.

[0032] A pair of guide rails 161 are arranged parallel to the Z-axis direction on the first Y-axis table 123. A support member 163 is installed on the pair of guide rails 161 so as to be slidable along these guide rails 161. A first cutting mechanism 18 is attached to the lower end of the support member 163.

[0033] The ball screw 160 is threadedly engaged with a nut portion (not shown) provided on the support member 163. The motor 162 is connected to one end of the ball screw 160 and rotates the ball screw 160. When the ball screw 160 is rotated, the support member 163 and the first cutting mechanism 18 move in the Z-axis direction along the guide rail 161.

[0034] The second lifting mechanism 17 also reciprocates the second cutting mechanism 19 in the Z-axis direction. The second lifting mechanism 17 has a similar configuration to the first lifting mechanism 16, and therefore a description thereof will be omitted.

[0035] The first cutting mechanism 18 cuts the wafer 100 held on the chuck table 20, and has a cutting blade 181 and an imaging mechanism 182. The imaging mechanism 182 captures an image of the wafer 100 held on the holding surface 22 of the chuck table 20 and detects the positions of the streets 102. The cutting blade 181 is used to cut the wafer 100 along the detected streets 102.

[0036] Similar to the first cutting mechanism 18, the second cutting mechanism 19 also cuts the wafer 100 held on the chuck table 20. The second cutting mechanism 19 has the same configuration as the first cutting mechanism 18, and therefore a description thereof will be omitted.

[0037] A spinner mechanism 55 is disposed on the +Y direction side of the opening 3 in the base 2. The spinner mechanism 55 is used to clean the wafer 100 after cutting. The spinner mechanism 55 is also used to form a protective film on the wafer 100 before cutting.

[0038] The spinner mechanism 55 includes a spinner table 56 that rotates while holding the work set 110 by suction, and a cleaning liquid nozzle 57 that sprays cleaning liquid from above onto the wafers 100 of the work set 110 that are held by suction on the spinner table 56.

[0039] The spinner mechanism 55 also includes a first liquid resin nozzle 58 for supplying a first liquid resin from above to the wafer 100 of the work set 110 held by suction on the spinner table 56, and a second liquid resin nozzle 59 for supplying a second liquid resin from above to the wafer 100.

[0040] A second transfer device 70 is provided above the spinner mechanism 55. The second transfer device 70 includes a second frame holding unit 71 that holds the ring frame 111 of the work set 110, a second Z-axis movement mechanism 72 that moves the second frame holding unit 71 in the Z-axis direction, and a second Y-axis movement mechanism 73 that moves the second frame holding unit 71 up and down in the Y-axis direction.

[0041] The second transport device 70 holds a work set 110 including wafers 100 that have undergone the specified cutting process by the first cutting mechanism 18 and the second cutting mechanism 19, and transports them from the chuck table 20 to the spinner table 56 of the spinner mechanism 55. The second transfer device 70 can also hold the work set 110 on the spinner table 56 of the spinner mechanism 55 and transfer it to the frame guide 41 of the temporary placement mechanism 40 or the holding surface 22 of the chuck table 20 .

[0042] The cutting device 1 is also provided with a control unit 7. The control unit 7 includes a CPU that performs calculations according to a control program, a storage medium such as a memory, etc. The control unit 7 executes various processes and controls each component of the cutting device 1.

[0043] For example, the control unit 7 controls the above-mentioned components of the cutting device 1 to execute the method for dividing the wafer 100. The following describes a method for dividing the wafer 100. This method involves cutting the wafer 100, which is held on the chuck table 20 and has a plurality of devices 103 and streets 102 formed on its surface, along the streets 102 with a cutting blade 181.

[0044] [First protective film formation process] First, a first protective film forming step is performed, in which a first liquid resin is applied to the entire surface of the wafer 100 to form a first protective film 115.

[0045] Specifically, the control unit 7 causes the drawer mechanism 30 to draw one work set 110 out of the cassette 11 in the +Y direction and temporarily place it on the frame guide 41 of the temporary placement mechanism 40. Thereafter, the control unit 7 controls the first transport device 60 to hold the work set 110 temporarily placed on the frame guide 41 and transport it to the spinner table 56 of the spinner mechanism 55, and the spinner table 56 holds the work set 110. Note that the control unit 7 may also cause the second transport device 70 to transport the work set 110 on the frame guide 41 to the spinner table 56.

[0046] Next, as shown in Fig. 2, the control unit 7 rotates the spinner table 56 holding the work set 110 and sprays the first liquid resin from the first liquid resin nozzle 58 toward the wafer 100 on the work set 110. As a result, the first liquid resin is supplied to the entire surface of the wafer 100, including the streets 102 and devices 103 (see Fig. 1), and a first protective film 115 made of the first liquid resin is formed. Note that the ring frame 111 is not shown in Figs. 2 to 5.

[0047] This first liquid resin is a resin that does not react with the cutting water (e.g., pure water) used in the subsequent kerf forming process (i.e., a resin that does not substantially react chemically with the cutting water and is not affected by the cutting water), such as an acrylic resin. This acrylic resin may contain functional groups such as hydroxyl groups, carboxyl groups, and sulfo groups in its structure. This first liquid resin made of an acrylic resin swells or dissolves in an alkaline cleaning solution whose main component is an organic alkali, thereby reducing its adhesive strength to the wafer 100.

[0048] The acrylic resin constituting the first liquid resin may contain a functional group such as an amino group in its structure. The first liquid resin made of this acrylic resin swells or dissolves in an acidic cleaning solution containing an organic acid as its main component, thereby reducing its adhesive strength to the wafer 100.

[0049] Therefore, the first protective film 115 made of the first liquid resin does not react with cutting water, but swells or dissolves in cleaning fluid made of an alkaline solution or an acidic solution, thereby reducing its adhesive strength and causing it to peel off from the surface of the wafer 100.

[0050] [Second protective film formation process] After the first protective film forming step, a second protective film forming step is carried out. In this step, a second liquid resin is applied to the entire surface of the first protective film 115, thereby forming a second protective film 116 on the first protective film 115. 3, the control unit 7 rotates the spinner table 56 holding the work set 110, and injects the second liquid resin from the second liquid resin nozzle 59 toward the first protective film 115 formed on the wafer 100 of the work set 110. As a result, the second liquid resin is supplied to the entire surface of the first protective film 115 formed on the surface of the wafer 100, and a second protective film 116 made of the second liquid resin is formed.

[0051] This second liquid resin is a resin that does not react with the cutting water (e.g., pure water) used in the cutting process, and also does not react with the alkaline or acidic cleaning liquid (i.e., a resin that does not substantially react chemically with the cutting water or cleaning liquid and is not affected by them). Therefore, the second protective film 116 made of the second liquid resin is also configured not to react with the cutting water or cleaning liquid, i.e., not to be swelled or dissolved by them.

[0052] In the following description, it is assumed that the cutting process of the wafer 100 is carried out using the first cutting mechanism 18 out of the first cutting mechanism 18 and the second cutting mechanism 19.

[0053] [Alignment process] After the second protective film forming step, an alignment step is performed in which the streets 102 on the surface of the wafer 100 are detected through the first protective film 115 and the second protective film 116.

[0054] Specifically, first, the control unit 7 controls the second transport device 70 (see Figure 1) to hold the work set 110 on the spinner table 56 of the spinner mechanism 55 and transport it to the chuck table 20, and then suction-holds the wafer 100 on the work set 110 by the holding surface 22 of the chuck table 20, while holding the ring frame 111 of the work set 110 by the clamp 25. Next, the control unit 7 controls the imaging mechanism 182 of the first cutting mechanism 18 to capture an image of the surface of the wafer 100 held on the holding surface 22 of the chuck table 20 through the first protective film 115 and the second protective film 116, and detects the position of the street 102 of the wafer 100.

[0055] [Kerf forming process] After the alignment step, a kerf forming step is performed. In this step, a kerf is formed in the second protective film 116, the first protective film 115, and the wafer 100 by cutting the cutting blade 181 along the street 102 while supplying cutting water from the second protective film 116.

[0056] Specifically, the control unit 7 adjusts the position of the chuck table 20 and the first cutting mechanism 18 using the rotation mechanism of the chuck table 20, the X-axis movement mechanism 37 and the movement mechanism 13, thereby aligning the position and orientation of the cutting blade 181 with one street 102 on the wafer 100 of the work set 110 held on the chuck table 20.

[0057] 4, the control unit 7 causes the first lifting mechanism 16 to lower the cutting blade 181 while rotating it, so that the cutting blade 181 cuts into the street 102. In this embodiment, the cutting blade 181 is lowered to a position where it can cut the wafer 100, for example.

[0058] Furthermore, the control unit 7 uses the X-axis direction moving mechanism 37 to move the chuck table 20 in the X-axis direction, which is the direction in which the street 102 extends. As a result, a kerf 117 having a depth sufficient to cut the wafer 100 is formed along the street 102, as shown in FIG. 5, and the wafer 100 is cut.

[0059] In this manner, the control unit 7 cuts the wafer 100 along these lines by forming kerfs 117 in the wafer 100 along all of the streets 102. This divides the wafer 100 into a plurality of chips 105.

[0060] [Cleaning process] After the kerf forming step, a cleaning step is performed in which an alkaline or acidic cleaning solution that does not react with the second protective film 116 but swells or dissolves the first protective film 115 is supplied from the second protective film 116 side of the kerf 117 to clean the kerf 117 while peeling off the first protective film 115 and the second protective film 116 from the surface of the wafer 100 by reducing the adhesive strength of the first protective film 115.

[0061] Specifically, the control unit 7 controls the second transport device 70 (see Figure 1) to transport the work set 110 including the wafer 100 on which the kerf 117 is formed from the chuck table 20 to the spinner table 56 of the spinner mechanism 55, and the work set 110 is held by the spinner table 56.

[0062] 5, the control unit 7 rotates the spinner table 56 at high speed and sprays the cleaning liquid from the cleaning liquid nozzle 57 toward the wafer 100, first protective film 115, and second protective film 116, which are being rotated at high speed, from the side of the second protective film 116. This cleaning liquid is the alkaline or acidic cleaning liquid described above, which does not react with the second protective film 116 but can swell or dissolve the first protective film 115.

[0063] As a result, the cleaning liquid that has entered the multiple kerfs 117 and reached the first protective film 115 swells or dissolves the first protective film 115, reducing the adhesive strength of the first protective film 115. As a result, the first protective film 115 is peeled off from the surface of the wafer 100 together with the second protective film 116 that is located above it. In addition, the cleaning liquid that has reached the wafer 100 cleans the wafer 100 (the kerfs 117 of the wafer 100).

[0064] Thereafter, the control unit 7 dries the surface of the wafer 100 by spraying dry air from a nozzle (not shown) onto the surface of the wafer 100 from which the first protective film 115 and the second protective film 116 have been peeled off.

[0065] 1 to hold work set 110 on spinner table 56 of spinner mechanism 55 and transport it to frame guide 41 of temporary placement mechanism 40. Thereafter, control unit 7 controls drawer mechanism 30 to store work set 110 on frame guide 41 in cassette 11.

[0066] As described above, in this embodiment, after the first protective film 115 and the second protective film 116 are formed on the surface of the wafer 100, the kerf 117 is formed therein by the cutting blade 181 in the cutting process in the kerf forming step. At this time, the first protective film 115 and the second protective film 116 do not react with the cutting water used in the cutting process, and therefore, the first protective film 115 and the second protective film 116 can be prevented from peeling off from the wafer 100. Therefore, it is possible to prevent cutting debris from adhering to the devices 103 (chips 105) of the wafer 100.

[0067] Moreover, the first protective film 115 is configured to swell or dissolve by the cleaning liquid used in the cleaning process. Therefore, when the kerf 117 is cleaned in the cleaning process, the adhesive strength of the first protective film 115 is reduced by the cleaning liquid, and the first protective film 115 and the second protective film 116 thereon can be easily peeled off from the wafer 100. Therefore, the kerf 117 of the wafer 100 can be cleaned well, and it is possible to prevent cutting debris from adhering (remaining) on ​​the chip 105.

[0068] Furthermore, in the cleaning process, second protective film 116 does not react with the cleaning liquid, and as first protective film 115 below second protective film 116 is peeled off from wafer 100, second protective film 116 is peeled off together with first protective film 115. Therefore, the amount of cleaning liquid required to peel first protective film 115 and second protective film 116 from wafer 100 can be reduced compared to a configuration in which both first protective film 115 and second protective film 116 react with the cleaning liquid. Therefore, according to this embodiment, it is possible to prevent cutting waste from adhering to the tip 105 without increasing production costs.

[0069] When forming first protective film 115 on the surface of wafer 100 in the first protective film forming step, it is preferable to make first protective film 115 relatively thin, for example, about 5 μm to 15 μm, which can speed up the penetration of cleaning liquid into first protective film 115 in the cleaning step, thereby enabling first protective film 115 and second protective film 116 to be quickly peeled off from wafer 100.

[0070] The first and second liquid resins used to form the first and second protective films 115 and 116 may be, for example, UV-curable, thermosetting, or two-component curable resins.

[0071] When the first liquid resin (second liquid resin) is a UV-curable or thermosetting resin, for example, an ultraviolet ray irradiation device or a heating device is provided in the spinner mechanism 55. When the first protective film 115 (second protective film 116) is formed, the first liquid resin (second liquid resin) supplied to the wafer 100 is subjected to an ultraviolet ray irradiation process or a heating process. Furthermore, when the first liquid resin (second liquid resin) is a two-component curing resin consisting of a main agent and a curing agent, the main agent and the curing agent are mixed together, for example, immediately before being sprayed from the nozzle.

[0072] In this embodiment, in the kerf forming step, the cutting blade 181 forms a kerf 117 with a depth that cuts the wafer 100, thereby forming a plurality of chips 105. In this regard, in the kerf forming step, the depth of the kerf 117 may be set to a depth that does not cut the wafer 100, and the wafer 100 may be half-cut.

[0073] When the wafer 100 is half-cut, after the kerf forming step, before or after the cleaning step, the half-cut wafer 100 may be fully cut using plasma in a plasma processing mechanism (not shown) to form a plurality of chips 105. This plasma processing mechanism may be provided in the cutting device 1 or may be a device separate from the cutting device 1.

[0074] Alternatively, after the kerf forming step, before or after the cleaning step, the dicing tape 113 may be expanded by an expansion mechanism (not shown) to fully cut the wafer 100 and form a plurality of chips 105. This expansion mechanism may be provided in the cutting device 1 or may be a device separate from the cutting device 1. [Explanation of symbols]

[0075] 1: cutting device, 2: base, 3: opening, 6: gate-type column, 7: control unit, 10: cassette stage, 11: cassette, 12: Y-axis direction movement mechanism, 13: movement mechanism, 16: First lifting mechanism, 17: Second lifting mechanism, 18: First cutting mechanism, 19: Second cutting mechanism, 20: chuck table, 22: holding surface, 25: clamp, 30: pull-out mechanism, 31: ball screw, 32: guide rail, 33: drawer arm, 33a: vertical portion, 33b: horizontal part, 34: motor, 35: bearing, 36: gripping part, 37: X-axis direction movement mechanism, 40: temporary placement mechanism, 41: frame guide, 42: spacing adjustment mechanism, 50: cassette lifting mechanism, 51: guide rail, 52: ball screw, 53: motor, 55: spinner mechanism, 56: spinner table, 57: cleaning liquid nozzle, 58: First liquid resin nozzle, 59: Second liquid resin nozzle, 60: First conveying device, 61: First frame holding portion, 62: First Z-axis moving mechanism, 63: First Y-axis lifting mechanism, 70: second transfer device, 71: second frame holding unit, 72: second Z-axis movement mechanism, 73: 2nd Y-axis movement mechanism, 100: wafer, 102: street, 103: device, 105: chip, 110: Work set, 111: Ring frame, 113: Dicing tape, 115: first protective film, 116: second protective film, 117: kerf, 120: First ball screw, 121: Guide rail, 122: Second ball screw, 123: first Y-axis table, 124: first motor, 125: second Y-axis table, 160: ball screw, 161: guide rail, 162: motor, 163: support member, 181: cutting blade, 182: imaging mechanism

Claims

[Claim 1] A wafer dividing method for cutting a wafer held on a chuck table and having a plurality of devices and streets formed on a surface thereof along the streets with a cutting blade, comprising: a first protective film forming step of forming a first protective film by applying a first liquid resin to the entire surface of the wafer; a second protective film forming step of forming a second protective film on the first protective film by applying a second liquid resin to the entire surface of the first protective film; an alignment step of detecting the street on the surface of the wafer through the first protective film and the second protective film; a kerf forming step of cutting the cutting blade along the street while supplying cutting water from the second protective film side to form a kerf in the second protective film, the first protective film, and the wafer; a cleaning step of supplying an alkaline or acidic cleaning solution that does not react with the second protective film but swells or dissolves the first protective film from the second protective film side of the kerf to reduce the adhesive strength of the first protective film, thereby cleaning the kerf while peeling off the first protective film and the second protective film from the surface of the wafer. Wafer division method.

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