Chip manufacturing method and tape application device

Abstract

To prevent a division failure and a production failure.SOLUTION: A chip manufacturing method includes: a modified layer forming step 1001 of irradiating a wafer with a laser beam with a wavelength having transmissivity to the wafer while locating a condensing point of the laser beam in the inside of the wafer, and forming modified layers to be division starting points along division scheduled lines; a grinding step 1002 of grinding a rear face of the wafer with a grindstone to reduce the thickness of the wafer to a finish thickness, and dividing the wafer along the division scheduled lines with the modified layers as the starting points; an expand tape sticking step 1004 of sticking an expand tape having elasticity to the rear face of the wafer subjected to grinding processing; and an expanding step 1005 of expanding the expand tape to increase the interval of chips along the division scheduled lines. The expand tape sticking step 1004 includes actuating a pressure roller two or more times in pressing to stick the expand tape to the rear face of the wafer.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a chip manufacturing method and a tape application device. [Background technology]

[0002] Thin device chips are manufactured by thinning a wafer by grinding it from the backside, and then dividing the wafer along the planned dividing lines.

[0003] The wafer is divided by, for example, cutting with a cutting blade or ablation processing using laser beam irradiation, but dividing the wafer by these methods can cause chips to form on the edges of the device chips or distortion on the side surfaces of the device chips, resulting in a problem of reduced flexural strength.

[0004] Therefore, a method for manufacturing device chips using a process called SDBG (Stealth Dicing Before Grinding) has been proposed (see, for example, Patent Document 1). In the process shown in Patent Document 1, a modified layer is formed on a wafer along a planned dividing line, and then the wafer is divided into device chips by grinding the wafer from the back side.

[0005] Incidentally, an adhesive film called DAF (Die Attach Film) that functions as an adhesive when mounting the device chip may be provided on the back surface of the manufactured device chip. In the SDBG process, the back surface of the wafer is ground to thin the wafer and form the device chip, and then the DAF is attached to the back surface of the wafer, and an expandable expanding tape is attached to the back surface, and the expanding tape is expanded by an expanding device to separate the DAF and manufacture the device chips (see, for example, Patent Document 2).

[0006] Here, adhesive tapes such as the expandable tape described above are usually attached to a wafer, which is a plate-like object, by pressing the adhesive tape using a roller or the like (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-12902 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-11445 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-5080 Summary of the Invention [Problem to be solved by the invention]

[0008] However, it became clear that there are cases where the expanding tape does not adhere well to the wafer, and even when the expanding tape is expanded, no tensile force is applied, resulting in problems such as the DAF and wafer not being able to be divided properly.

[0009] A method was also considered in which the expanding tape was attached to the wafer by applying strong pressure to the expanding tape, but this could cause cracks to extend in unintended directions from the previously formed modified layer, resulting in product defects.

[0010] The present invention has been made in view of the above circumstances, and its object is to provide a chip manufacturing method and tape application device that can suppress division defects and product defects. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems and achieve the object, the chip manufacturing method of the present invention is a chip manufacturing method for manufacturing chips by dividing a wafer having devices in areas defined by a plurality of planned dividing lines set on the surface, and includes a modified layer forming step of irradiating the wafer with a laser beam having a wavelength that is transparent to the wafer, with the focal point positioned inside the wafer, to form modified layers that serve as dividing starting points along the planned dividing lines; a grinding step of grinding the back surface of the wafer with a grinding means to thin the wafer to a finishing thickness and dividing the wafer along the planned dividing lines using the modified layers as starting points; and a die bonding step of forming die bonding on the back surface of the ground wafer after the grinding step. and an expanding step of expanding the expanding tape to widen the gaps between the chips along the planned dividing lines, thereby dividing the adhesive film into chips. The expanding tape applying step presses the expanding tape against the rear surface of the wafer to apply the expanding tape to the adhesive film, and when the expanding tape is applied to the adhesive film, a pressing roller that presses the expanding tape against the rear surface of the wafer moves from one end to the other end of the adhesive film two or more times. At the same time, the pressure with which the pressure roller presses the expanding tape against the back surface of the wafer is equal to the pressure with which a separation failure of the adhesive film occurs even if the expanding tape is expanded after the operation is performed only once. It is characterized by:

[0013] The tape application device of the present invention is adapted to apply a tape to a wafer which has been divided into individual chips along the division lines and has an adhesive film applied to the backside thereof. Expand A tape application device for applying tape, which is a strip-shaped tape having an adhesive layer on one side of a base material. The expander The tape body, in which the tape is temporarily adhered to the release sheet, is set in a rolled state, and the release sheet side is set downward. Expand a tape feeding section for feeding out a tape; Expand a sheet peeling section that peels the release sheet from the tape; a release sheet winding section that winds up the release sheet peeled by the sheet peeling section; Expand The adhesive surface of the tape is placed facing the wafer. Expand a pressure roller for pressing the tape toward the wafer, The expander The tape is pressed against the backside of the wafer. Expand When adhering the tape to the adhesive film, The pressure roller that presses the expanding tape against the back surface of the wafer The adhesive film is set to move from one end to the other end two or more times. and the pressure with which the pressure roller presses the expanding tape against the back surface of the wafer is equal to the pressure with which a division failure of the adhesive film occurs even if the expanding tape is expanded after the operation is performed only once, The present invention is characterized by being able to prevent excessive pressure from being applied to the wafer. [Effects of the Invention]

[0014] The present invention has an effect of making it possible to suppress defective divisions and defective products. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a side view schematically showing the general configuration of a tape application device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of a wafer to which an expanding tape has been applied by the tape application device shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view of an expanding tape to be applied to a wafer by the tape application device shown in FIG. [Figure 4] FIG. 4 is a flowchart showing the flow of the method for manufacturing the chip according to the first embodiment. [Figure 5] FIG. 5 is a perspective view schematically showing a modified layer forming step in the method for manufacturing the chip shown in FIG. [Figure 6] FIG. 6 is a side view, partly in section, schematically showing the grinding step of the method for producing the tip shown in FIG. [Figure 7] FIG. 7 is a perspective view schematically showing an adhesive film attachment step in the method for producing the chip shown in FIG. [Figure 8] FIG. 8 is a side view schematically showing an expanding tape attaching step in the method for producing the chip shown in FIG. [Figure 9]FIG. 9 is a side view, partly in section, schematically showing a state in which the expansion device holds the wafer in the expansion step of the chip manufacturing method shown in FIG. [Figure 10] 10 is a side view, partially in cross section, schematically showing a state in which the expansion device has expanded the gap between the chips in the expansion step of the chip manufacturing method shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] 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.

[0017] [Embodiment 1] A tape application device according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view schematically showing the general configuration of the tape application device according to the first embodiment. Fig. 2 is a perspective view of a wafer to which expanding tape has been applied by the tape application device shown in Fig. 1. Fig. 3 is a cross-sectional view of the expanding tape applied to a wafer by the tape application device shown in Fig. 1.

[0018] (wafer) 1 according to the first embodiment is an apparatus for applying an expanding tape 201 (corresponding to a tape and an adhesive tape) to a wafer 200, as shown in Fig. 2. The wafer 200 to which the expanding tape 201 is applied by the tape application apparatus 1 according to the first embodiment is a disk-shaped semiconductor wafer, optical device wafer, or the like, having a substrate made of silicon (Si), sapphire (Al2O3), gallium arsenide (GaAs), silicon carbide (SiC), or the like.

[0019] 2, the wafer 200 has devices 204 in each region defined by a plurality of planned division lines 203 set on a surface 202. The devices 204 are, for example, integrated circuits such as ICs (Integrated Circuits) or LSIs (Large Scale Integrations), image sensors such as CCDs (Charge Coupled Devices) or CMOSs ​​(Complementary Metal Oxide Semiconductors), or MEMS (Micro Electro Mechanical Systems).

[0020] In embodiment 1, a modified layer 205 is formed inside the substrate of the wafer 200 along the dividing lines 203, and the back surface 206 side behind the front surface 202 is ground to be thinned to a predetermined finished thickness 207. A DAF 208 (Die Attach Film) which is an adhesive film for die bonding and an expanding tape 201 are attached to the back surface 206 side of the wafer 200, and an annular frame 209 whose inner diameter is larger than the outer diameter of the wafer 200 is attached to the outer edge of the expanding tape 201, and the wafer 200 is supported inside the annular frame 209. The wafer 200 is divided into individual chips 210 along the dividing lines 203. Each chip 210 includes a portion of the substrate and a device 204.

[0021] The modified layer 205 refers to a region where the density, refractive index, mechanical strength, or other physical properties are different from those of the surrounding area, and examples thereof include a melting treatment region, a crack region, a dielectric breakdown region, a refractive index change region, and a region where these regions are mixed. The modified layer 205 also has lower mechanical strength than other parts of the substrate of the wafer 200. The DAF 208 is an adhesive film for die bonding that fixes the chip 210 to another chip or a substrate. In the first embodiment, the DAF 208 is formed in a disk shape with an outer diameter the same as that of the wafer 200, and is divided into individual chips 210.

[0022] (Expanding tape) In embodiment 1, the expanding tape 201 adhered to the wafer 200 by the tape application device 1 includes a base material 211 made of a non-adhesive resin that is stretchable and flexible, and an adhesive layer 212 laminated on one side of the base material 211 and that is adhesive, stretchable, and flexible, as shown in Fig. 3. For this reason, the expanding tape 201 is stretchable. The expanding tape 201 is set in the tape application device 1 in a strip-like state, with the adhesive layer 212 temporarily adhered to a release sheet 213, and the release sheet 213 temporarily adhered to the adhesive layer 212 to form a tape body 214. Note that "temporarily fixed" means that the release sheet 213 is releasably adhered to the adhesive layer 212.

[0023] (Tape application device) As shown in FIG. 1, the tape application device 1 has a chuck table 2, a tape feeding section 3, a sheet peeling section 4, a peeling sheet winding section 5, a pressure roller 6, a relative movement section (not shown), a tape cutting section (not shown), an unnecessary tape winding section 7, and a control unit 8.

[0024] The chuck table 2 holds the wafer 200 and the annular frame 209. The chuck table 2 has a holding surface 9 whose upper surface is formed flat along the horizontal direction, and the wafer 200 and the annular frame 209, which are carried in by a transport unit (not shown), are placed on the holding surface 9 and held thereon.

[0025] The tape feed-out unit 3 is set with a tape body 214, in which a strip-shaped expanding tape 201 is temporarily bonded to a release sheet 213, wound in a roll, and feeds the expanding tape 201 above the holding surface 9 of the chuck table 2 with the release sheet 213 side facing downward. In embodiment 1, the tape feed-out unit 3 is arranged horizontally on one side to the left of the chuck table 2 in FIG. 1 , is formed in a cylindrical shape with an axis parallel to the horizontal direction, and is provided to be rotatable about the axis. The tape feed-out unit 3 is set with the tape body 214 wound in a roll with the release sheet 213 positioned on the outside and wound around the outer periphery. In embodiment 1, the release sheet 213 is peeled off from the end of the tape body 214 by the sheet peeling unit 4, and the tape body 214 is attached to the wafer 200 and the annular frame 209.

[0026] The sheet peeling unit 4 peels the release sheet 213 from the expanding tape 201 fed out from the tape feed-out unit 3. The sheet peeling unit 4 is disposed between the tape feed-out unit 3 and the chuck table 2, is formed in a cylindrical shape with its axis parallel to that of the tape feed-out unit 3, and is supported so as to be rotatable about its axis. The outer peripheral surface of the sheet peeling unit 4 abuts against the release sheet 213 of the tape body 214, and rotates about its axis in conjunction with the feeding of the tape body 214 from the tape feed-out unit 3 upwardly to the holding surface 9 of the chuck table 2. By abutting the outer peripheral surface of the sheet peeling unit 4 against the release sheet 213 of the tape body 214, the sheet peeling unit 4 peels the release sheet 213 from the tape body 214 and feeds the expanding tape 201 upwardly to the holding surface 9 of the chuck table 2.

[0027] The release sheet take-up unit 5 takes up the release sheet 213 peeled off by the sheet peeling unit 4 from the tape body 214 fed out from the tape feed-out unit 3. In the first embodiment, the release sheet take-up unit 5 is located below the tape feed-out unit 3. The release sheet take-up unit 5 is formed in a cylindrical shape with its axis parallel to the axes of the tape feed-out unit 3 and the sheet peeling unit 4, and is rotated around its axis by a driving device such as a motor (not shown), thereby taking up the release sheet 213 peeled off from the tape body 214 onto its outer circumferential surface.

[0028] The tape application device 1 also includes a pair of tension applying units 10. The tension applying units 10 are cylindrical in shape with their axes parallel to the axes of the tape feed-out unit 3, the sheet peeling unit 4, and the release sheet take-up unit 5, and are rotatable about their axes. One tension applying unit 10 is disposed above the holding surface 9 of the chuck table 2 and on one side of the chuck table 2 to the left in FIG. 1 along the horizontal direction, while the other tension applying unit 10 is disposed above the holding surface 9 of the chuck table 2 and on the other side of the chuck table 2 to the right in FIG. 1 along the horizontal direction. The tension applying unit 10 brings the expanding tape 201, which has been fed out from the tape feed-out unit 3 above the holding surface 9 of the chuck table 2, into contact with its outer peripheral surface, and rotates about its axis in conjunction with the feeding of the expanding tape 201, thereby applying tension to prevent slack in the expanding tape 201.

[0029] The pressure roller 6 faces the wafer 200 with the adhesive surface 215, which is the surface of the adhesive layer 212 of the expanding tape 201 fed above the holding surface 9 of the chuck table 2 by the tape feeding unit 3, facing the wafer 200, and presses the expanding tape 201 toward the wafer 200 on the holding surface 9 and toward the annular frame 209. The pressure roller 6 is formed in a cylindrical shape with its axis parallel to the axes of the tape feeding unit 3, the sheet peeling unit 4, the release sheet winding unit 5, and the tension applying unit 10, and is provided so as to be rotatable about its axis.

[0030] The pressure roller 6 is provided so as to be movable relative to the chuck table 2 in a direction parallel to the horizontal direction and perpendicular to the aforementioned axis by a relative movement unit (not shown), and is also provided so as to be movable in the vertical direction. The pressure roller 6 is moved relative to the chuck table 2 in a direction parallel to the horizontal direction and perpendicular to the aforementioned axis by the relative movement unit, and is also moved relatively in the vertical direction, moving along the holding surface 9 and rolling on the base material 211, pressing the adhesive surface 215 of the expanding tape 201 against the wafer 200 and the annular frame 209 on the holding surface 9, thereby bonding the expanding tape 201 to the wafer 200 and the annular frame 209 on the holding surface 9. The pressure with which the expanding tape 201 is pressed against the wafer 200 on the holding surface 9 can be changed by the pressure roller 6 being moved relative to the chuck table 2 in the vertical direction by the relative movement unit. Furthermore, in the present invention, the pressure of the pressing roller 6 for pressing the expanding tape 201 against the wafer 200 does not need to be variable.

[0031] The tape cutting section cuts the wafer 200 and the expanding tape 201 attached to the annular frame 209 between the inner edge and the outer edge of the annular frame 209 .

[0032] The unnecessary tape take-up unit 7 takes up the unnecessary portion of the expanding tape 201 after the tape cutting unit has cut the gap between the inner edge and outer edge of the annular frame 209. In the first embodiment, the unnecessary tape take-up unit 7 is arranged horizontally on the other side to the right of the chuck table 2 in FIG. 1, and is formed in a cylindrical shape with its axis parallel to the axes of the tape feed unit 3, the sheet peeling unit 4, the release sheet take-up unit 5, the tension applying unit 10, and the pressure roller 6. The unnecessary tape take-up unit 7 is rotated about its axis by a driving device such as a motor (not shown), thereby taking up the unnecessary portion of the expanding tape 201 around its outer peripheral surface.

[0033] The control unit 8 controls each of the above-mentioned components constituting the tape application apparatus 1, and causes the tape application apparatus 1 to perform the operation of applying the expanding tape 201 to the wafer 200 and the annular frame 209. The control unit 8 is a computer that has an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having memory such as a ROM (read only memory) or RAM (random access memory), and an input / output interface device, and is capable of executing computer programs.

[0034] The arithmetic processing unit of the control unit 8 executes on the RAM a computer program stored in the ROM to generate control signals for controlling the tape application device 1. The arithmetic processing unit of the control unit 8 outputs the generated control signals to each component of the tape application device 1 via the input / output interface device.

[0035] The control unit 8 is also connected to a display unit configured with a liquid crystal display device or the like that displays the state of the adhering operation, images, etc., and an input unit that the operator uses to register processing content information, etc. The input unit is configured with at least one of a touch panel provided on the display unit and a keyboard, etc.

[0036] (Chip manufacturing method) Next, a method for manufacturing a chip according to the first embodiment will be described with reference to the drawings. Fig. 4 is a flowchart showing the flow of the method for manufacturing a chip according to the first embodiment. The method for manufacturing a chip according to the first embodiment is a method for manufacturing chips 210 by dividing a wafer 200 having devices 204 in regions defined by a plurality of planned division lines 203 set on a surface 202 along the planned division lines 203. As shown in Fig. 4, the method for manufacturing a chip according to the first embodiment includes a modified layer forming step 1001, a grinding step 1002, an adhesive film applying step 1003, an expandable tape applying step 1004, and an expanding step 1005.

[0037] (Modified layer formation step) Fig. 5 is a perspective view schematically showing a modified layer forming step in the method for manufacturing the chip shown in Fig. 4. The modified layer forming step 1001 is a step in which a focal point 24 of a laser beam 23 having a wavelength (1030 nm to 1310 nm in the first embodiment) that is transparent to the wafer 200 is positioned inside the substrate of the wafer 200 and irradiated with the laser beam, thereby forming modified layers 205 that serve as starting points for division along the planned division lines 203.

[0038] In the first embodiment, in the modified layer forming step 1001, a central portion of a disk-shaped protective tape 220 having a diameter larger than that of the wafer 200 is attached to the front surface 202 side of the wafer 200, and an annular frame 221 having an inner diameter larger than that of the wafer 200 is attached to the outer edge of the protective tape 220. In the first embodiment, in the modified layer forming step 1001, the laser processing apparatus 20 suction-holds the front surface 202 side of the wafer 200 on the holding surface of the chuck table 21 via the protective tape 220. In the modified layer forming step 1001, as shown in FIG. 5 , the laser processing apparatus 20 sets the focal point 24 of the laser beam application unit 22 inside the substrate, and irradiates a pulsed laser beam 23 from the back surface 206 side of the wafer 200 along the planned division line 203 while moving the chuck table 21 and the laser beam application unit 22 relatively along the planned division line 203.

[0039] In the first embodiment, in the modified layer forming step 1001, the laser processing apparatus 20 irradiates the wafer 200, which is held by suction on the chuck table 21, with a laser beam 23 from the laser beam application unit 22 while moving the chuck table 21. In the modified layer forming step 1001, the laser processing apparatus 20 irradiates the laser beam 23 having a wavelength that is transparent to the wafer 200, thereby forming modified layers 205 along the planned dividing lines 203 inside the substrate, as shown in FIG. 5 . In the modified layer forming step 1001, the laser processing apparatus 20 forms modified layers 205 inside the substrate along all of the planned dividing lines 203.

[0040] In the present invention, in the modified layer forming step 1001, a protective tape may be attached to the back surface 206 of the wafer 200, and the laser beam 23 may be irradiated from the front surface 202 side of the wafer 200 to form the modified layer 205 inside the substrate, and then the protective tape 220 may be attached to the front surface 202 side of the wafer 200 and the protective tape on the back surface 206 side may be peeled off. In short, in the present invention, the wafer 200 may be transferred to the protective tape 220 after the laser beam 23 is irradiated onto the wafer 200.

[0041] (Grinding step) Fig. 6 is a side view, partially in cross section, showing a schematic diagram of the grinding step in the chip manufacturing method shown in Fig. 4. In the grinding step 1002, after the modified layer forming step 1001 is performed, the back surface 206 side of the wafer 200 is ground with a grinding wheel 35, which is a grinding means, to thin the wafer 200 to a finishing thickness 207, and the wafer 200 is divided into individual chips 210 along the planned division lines 203 starting from the modified layer 205.

[0042] In the first embodiment, in the grinding step 1002, the grinding device 30 suction-holds the front surface 202 of the wafer 200 on the holding surface 32 of the chuck table 31 via the protective tape 220. In the grinding step 1002, as shown in Fig. 6, the spindle 33 rotates the grinding wheel 34 about its axis, and the chuck table 31 is also rotated about its axis, and while a grinding fluid (not shown), such as pure water, is supplied, the grinding stone 35 of the grinding wheel 34 is brought into contact with the back surface 206 of the wafer 200 and moved toward the chuck table 31 at a predetermined feed rate, so that the grinding stone 35 grinds the back surface 206 of the wafer 200, thereby thinning the wafer 200. In the grinding step 1002, the wafer 200 is divided into individual chips 210 along the planned division lines 203 starting from the modified layer 205 due to the load applied by grinding. In the first embodiment, in the grinding step 1002, the grinding device 30 thins the wafer 200 to the finish thickness 207.

[0043] (Adhesive film application step) Fig. 7 is a perspective view that schematically shows the adhesive film attachment step of the chip manufacturing method shown in Fig. 4. Note that Fig. 7 shows only the disk-shaped portion of protective tape 220 that has the same diameter as wafer 200, and omits other portions of protective tape 220 and annular frame 209.

[0044] Adhesive film applying step 1003 is a step of applying a DAF 208 to the back surface 206 of the ground wafer 200 after grinding step 1002 and before expand tape applying step 1004. In embodiment 1, in adhesive film applying step 1003, as shown in FIG. 7 , the DAF 208 is applied to the back surface 206 of the wafer 200, and the protective tape 220 is peeled off from the front surface 202.

[0045] (Expanding tape application step) Fig. 8 is a side view schematically showing the expand tape adhering step in the method for manufacturing the chip shown in Fig. 4. The expand tape adhering step 1004 is a step in which, after the grinding step 1002, an expand tape 201 having elasticity is adhered to the back surface 206 of the ground wafer 200.

[0046] In embodiment 1, in the expanding tape application step 1004, the tape application device 1 holds the front surface 202 side of the wafer 200 and the annular frame 209 on the holding surface 9 of the chuck table 2, as shown in FIG. 8, brings the expanding tape 201 drawn out from the tape body 214 set in the tape feed section 3 into contact with the outer peripheral surface of the sheet peeling section 4, winds the release sheet 213 around the release sheet winding section 5, passes the expanding tape 201 below the tension applying section 10 and winds it around the unnecessary tape winding section 7, and guides the expanding tape 201 onto the holding surface 9 of the chuck table 2 with the adhesive layer 212 facing the wafer 200 and the annular frame 209.

[0047] In the expanding tape application step 1004, the tape application device 1 moves the pressure roller 6 and the chuck table 2 relatively using the relative movement unit, and applies the expanding tape 201 between the pair of tension application units 10 to the wafer 200 and the annular frame 209. In embodiment 1, in the expanding tape application step 1004, the control unit 8 of the tape application device 1 controls the relative movement part to position the pressure roller 6 on one end of the expanding tape 201 on the wafer 200 on the left side of FIG. 8 on the upstream side in the movement direction of the expanding tape 201, and then moves the pressure roller 6 closer to the chuck table 2 to apply the expanding tape 201 to one end of the DAF 208 applied to the back surface 206 of the wafer 200. While pressing the pressure roller 6 against the back surface 206 of the wafer 200, the pressure roller 6 is moved along the back surface 206 of the wafer 200 toward the other end of the expanding tape 201 on the wafer 200 on the right side of FIG. 8 on the downstream side in the movement direction of the expanding tape 201, causing it to roll on the expanding tape 201.

[0048] In embodiment 1, in expanding tape application step 1004, the tape application apparatus 1 applies the expanding tape 201 sequentially from one end to the other end of the DAF 208 that has been applied to the back surface 206 of the wafer 200, and once the expanding tape has been applied to the other end of the DAF 208, moves the pressure roller 6 away from the chuck table 2. In embodiment 1, the pressure with which the pressure roller 6 presses the expanding tape 201 against the back surface 206 of the wafer 200 in expanding tape application step 1004 is equal to the pressure with which a conventional tape application apparatus applies the expanding tape 201. In embodiment 1, the pressure with which the pressure roller 6 presses the expanding tape 201 against the back surface 206 of the wafer 200 in expanding tape application step 1004 is, for example, 0.34 MPa (gauge pressure).

[0049] Also, in embodiment 1, in expanding tape applying step 1004, the tape applying device 1 performs the operation (corresponding to the operation of the pressing roller 6, in which the pressing roller 6 approaches the chuck table 2, moves from one end to the other end, and moves away from the chuck table 2 at the other end) multiple times (i.e., two or more times) when the pressing roller 6 applies the expanding tape 201 to the DAF 208 applied to the back surface 206 of the wafer 200. Thus, in expanding tape applying step 1004, the tape applying device 1 operates the pressing roller 6 two or more times (for example, twice in embodiment 1) when pressing the expanding tape 201 against the back surface 206 of the wafer 200 to apply it. Furthermore, the tape application device 1 is set to operate so that the pressure roller 6 presses the expanding tape 201 toward the wafer 200 multiple times, and since the pressing pressure is the same as conventional pressure, excessive pressure is prevented from being applied to the wafer 200 in the expanding tape application step 1004.

[0050] In embodiment 1, in the expanding tape applying step 1004, the tape applying device 1 operates the pressure roller 6 twice to apply the expanding tape 201 to the DAF 208 and the annular frame 209 that are applied to the back surface 206 of the wafer 200 held on the chuck table 2, and then cuts the expanding tape 201 applied to the wafer 200 and the annular frame 209 between the inner edge and the outer edge of the annular frame 209 with the tape cutting unit. In embodiment 1, in the expanding tape applying step 1004, the tape applying device 1 retracts the pressure roller 6 and the tape cutting unit from the expanding tape 201 between the pair of tension applying units 10, and carries out the wafer 200 and the annular frame 209, with the expanding tape 201 applied to the DAF 208, from the holding surface 9 of the chuck table 2.

[0051] In embodiment 1, the tape application device 1 prepares to apply the expanding tape 201 to the next wafer 200 by retracting the pressure roller 6 and the tape cutting unit from the expanding tape 201 between the pair of tension applying units 10, and winding the expanding tape 201 onto the unnecessary tape winding unit 7 by an amount corresponding to the outer diameter of the disc-shaped expanding tape 201 applied to the wafer 200. Thus, in embodiment 1, in the expanding tape applying step 1004, the expanding tape 201 is applied to the DAF 208 applied in the adhesive film applying step 1003, thereby applying the expanding tape 201 to the back surface 206 of the wafer 200 via the DAF 208. However, in the present invention, in the expanding tape application step 1004, the expanding tape 201 having the DAF 208 previously attached to the adhesive layer 212 may be applied to the back surface 206 of the wafer 200, and the adhesive film application step 1003 and the expanding tape application step 1004 may be carried out simultaneously by the tape application device 1.

[0052] (extension step) Fig. 9 is a side view, partially in section, showing a state in which the expansion device holds a wafer in the expansion step of the chip manufacturing method shown in Fig. 4. Fig. 10 is a side view, partially in section, showing a state in which the expansion device has widened the gap between chips in the expansion step of the chip manufacturing method shown in Fig. 4.

[0053] The expanding step 1005 is a step in which the expanding tape 201 is expanded to widen the spaces between the chips 210 along the planned division lines 203. In the expanding step 1005, as shown in Fig. 9, the expanding device 40 clamps and holds the outer edge of the expanding tape 201 and the annular frame 209 supporting the wafer 200 inside with the frame clamping section 41, and also brings the roller members 43 provided at the upper end of the cylindrical expanding drum 42 into contact with the expanding tape 201.

[0054] 9, in the expanding step 1005, the expanding device 50 holds the annular frame 209 supporting the wafer 200 and the like with the frame clamping portion 41, with the expanding tape 201 being flat from the outer edge portion to the center portion. In the expanding step 1005, the expanding device 40 moves the annular frame 209 and the wafer 200 relatively along a direction intersecting (orthogonal in embodiment 1) the surface 202 of the wafer 200. In embodiment 1, in the expanding step 1005, the expanding device 40 raises the expansion drum 42, and moves the annular frame 209 and the wafer 200 relatively along a direction intersecting (orthogonal in embodiment 1) the surface 202 of the wafer 200, as shown in FIG.

[0055] Then, the roller members 43 press upward from below between the outer edge of the wafer 200 and the inner edge of the annular frame 209 on the expanding tape 201, causing the expanding tape 201 to expand in the planar direction. As a result of the expansion of the expanding tape 201, a tensile force acts radially on the expanding tape 201. When a tensile force acts radially on the expanding tape 201 attached to the back surface 206 of the wafer 200, the wafer 200 is divided into individual chips 210 along the planned division lines 203, and therefore the spaces between the chips 210 are widened. Furthermore, in the expanding step 1005, the DAF 208 is attached to the back surface 206 of the wafer 200, and the expanding tape 201 is attached to the DAF 208, so that the expansion of the expanding tape 201 acts on the DAF 208 in the expanding direction, causing the DAF 208 to break between the chips 210 and be separated into individual chips 210. In this way, the spacing between the chips 210 of the wafer 200 is widened, and the DAF 208 is separated into individual chips 210. The individually separated chips 210 are picked up from the expanding tape 201 together with the DAF 208.

[0056] The chip manufacturing method and tape application device 1 according to the first embodiment described above operates the pressure roller 6 multiple times to apply the expanding tape 201 to the wafer 200, and because the pressure applied by the pressure roller 6 is the same as that of a conventional method, it is possible to prevent cracks in unexpected directions that may cross the planned division line 203 of the wafer 200 due to excessive pressure, and to prevent insufficient application of the expanding tape 201 to the DAF 208. The chip manufacturing method and tape application device 1 according to the first embodiment have the effect of making it possible to manufacture the chips 210 without causing poor division of the DAF 208 or defective products of the chips 210.

[0057] Next, the inventors of the present invention confirmed the effects of the chip manufacturing method according to the above-mentioned embodiment 1 by dividing the same wafer 200 into individual chips 210 for each of comparative examples 1 and 2 and invention products 1 and 2, measuring the ratio of individual chips 210 (hereinafter referred to as division rate) and checking for the presence or absence of product defects (division along lines other than the planned division line 203). The results are shown in Table 1.

[0058] [Table 1]

[0059] In Comparative Example 1 of Table 1, the operation of the pressure roller 6 in the expand tape application step 1004 of the chip manufacturing method of embodiment 1 was set to one time, and the pressure applied by the pressure roller 6 was set to 0.34 MPa (gauge pressure), and the modified layer formation step 1001, grinding step 1002, adhesive film application step 1003, expand tape application step 1004, and expansion step 1005 were performed in that order to divide the wafer 200 into individual chips 210.

[0060] In Comparative Example 2 of Table 1, the operation of the pressure roller 6 in the expand tape application step 1004 of the chip manufacturing method of embodiment 1 was limited to one operation, and the pressure applied by the pressure roller 6 was set to 0.68 MPa (gauge pressure), and the modified layer formation step 1001, grinding step 1002, adhesive film application step 1003, expand tape application step 1004, and expansion step 1005 were performed in that order to divide the wafer 200 into individual chips 210.

[0061] For product 1 of the present invention in Table 1, the pressure roller 6 was operated twice in the expanding tape application step 1004, and the pressure applied by the pressure roller 6 was set to 0.34 MPa (gauge pressure), and the chip manufacturing method of embodiment 1 was carried out to divide the wafer 200 into individual chips 210.

[0062] For product 2 of the present invention in Table 1, the pressure roller 6 operates twice in the expanding tape application step 1004, the pressure applied by the pressure roller 6 is 0.34 MPa (gauge pressure), the expanding tape 201 with the DAF 208 previously applied thereto is applied to the back surface 206 of the wafer 200, and the adhesive film application step 1003 and the expanding tape application step 1004 are performed simultaneously. Except for this, the chip manufacturing method of embodiment 1 is carried out, and the wafer 200 is divided into individual chips 210.

[0063] The results are shown in Table 1. In the confirmation, the processing conditions for the modified layer forming step 1001, grinding step 1002 and expansion step 1005 of Comparative Examples 1 and 2 were the same as the processing conditions for the modified layer forming step 1001, grinding step 1002 and expansion step 1005 of Products 1 and 2 of the present invention.

[0064] According to Table 1, in Comparative Examples 1 and 2, only 60% or 80% of the chips 210 could be separated into individual pieces. In contrast to such Comparative Examples 1 and 2, in Invention Products 1 and 2, 100% of the chips 210 could be separated into individual pieces. Also, according to Table 1, in Comparative Example 2, there were product defects. In contrast to such Comparative Example 2, there were no product defects in Invention Products 1 and 2.

[0065] Therefore, according to Table 1, it has become clear that by operating the pressure roller 6 multiple times in the expanding tape application step 1004 to apply the expanding tape 201 to the wafer 200 and keeping the pressing pressure the same as the conventional pressure, it is possible to manufacture the chip 210 without causing poor division of the DAF 208 or product defects in the chip 210.

[0066] 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 present invention, the expanding tape 201 may be attached to the back surface 206 of the wafer 200 without attaching the DAF 208 to the back surface 206 of the wafer 200, i.e., without performing the adhesive film attaching step 1003, and the wafer 200 may be divided into individual chips 210. Furthermore, in the present invention, in the expanding tape attaching step 1004, the pressing roller 6 may be moved back and forth between the one end and the other end, and the pressing roller 6 may be operated multiple times to attach the expanding tape 201. Furthermore, in the present invention, in addition to forming the modified layer 205 on the wafer 200, plasma dicing may also be performed. [Explanation of symbols]

[0067] 1 Tape application device 3 Tape feeding section 4 Sheet peeling section 5. Release sheet winding section 6 Pressure roller 23 Laser Beam 24 Focusing point 35 Grinding wheel (grinding means) 200 wafers 201 Expanding tape (tape, adhesive tape) 202 Surface 203 Planned division line 204 devices 205 Modified Layer 206 Back side 207 Finished Thickness 210 chips 211 Base material 212 Adhesive layer 213 Peel-off sheet 214 Tape 215 Adhesive surface 1001 Modified layer formation step 1002 Grinding Step 1003 Adhesive film application step 1004 Expanding tape application step 1005 Extended Step

Claims

1. A chip manufacturing method for manufacturing chips by dividing a wafer having devices in areas defined by a plurality of planned dividing lines set on a surface thereof, a modified layer forming step of irradiating the wafer with a laser beam having a wavelength that is transparent to the wafer, with the focal point positioned inside the wafer, to form modified layers that serve as dividing starting points along the dividing lines; a grinding step in which, after the modified layer forming step, the back surface of the wafer is ground by a grinding means to thin the wafer to a finishing thickness and the wafer is divided into individual chips along the planned division lines starting from the modified layer; After the grinding step, an adhesive film adhering step of adhering an adhesive film for die bonding to the back surface of the ground wafer; After the grinding step, an expandable tape adhering step is performed in which an expandable tape is adhered to the adhesive film adhered to the back surface of the ground wafer; an expanding step of expanding the expandable tape to widen the gap between each chip along the dividing line, thereby dividing the adhesive film into each chip; The expanding tape applying step includes: A method for manufacturing a chip, characterized in that when pressing the expanding tape against the back surface of the wafer to adhere the expanding tape to the adhesive film, a pressing roller that presses the expanding tape against the back surface of the wafer moves from one end to the other end of the adhesive film two or more times, and the pressure with which the pressing roller presses the expanding tape against the back surface of the wafer is equal to the pressing pressure at which failure to separate the adhesive film occurs even if the expanding tape is expanded after performing the operation only once.

2. A tape application device that applies an expandable tape to a wafer that has been divided into individual chips along a planned division line and has an adhesive film attached to its back surface, a tape delivery section in which a tape body in the form of a strip of expanding tape having an adhesive layer on one side of a base material and temporarily adhered to a release sheet is set in a rolled state, and which delivers the expanding tape with the release sheet side facing downward; a sheet peeling unit that peels the release sheet from the expanding tape fed from the tape feeding unit; a release sheet winding section that winds up the release sheet peeled off by the sheet peeling section; a pressure roller that presses the expanding tape toward the wafer with the adhesive surface of the expanding tape fed by the tape feeding section facing the wafer, When the expanding tape is pressed against the back surface of the wafer to bond the expanding tape to the adhesive film, the pressing roller that presses the expanding tape against the back surface of the wafer is set to move from one end to the other end of the adhesive film two or more times, and the pressure with which the pressing roller presses the expanding tape against the back surface of the wafer is equal to the pressing pressure at which failure to separate the adhesive film occurs even if the expanding tape is expanded after performing the operation only once, To provide a tape adhering device capable of preventing excessive pressure from being applied to a wafer.

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