JP7614870B2 - How to check DAF division - Google Patents

Description

The present invention relates to a method for checking whether a DAF arranged on the back surface of a wafer has been properly divided into chips.

A wafer with multiple devices such as ICs and LSIs formed on its surface, partitioned by planned division lines, has its back surface ground by a grinding machine and formed to the desired thickness. After that, it is divided into individual device chips by a dicing machine and laser processing machine and used in electrical devices such as mobile phones and personal computers.

A technology has also been proposed in which half-cut grooves are formed along the intended dividing line from the front surface of the wafer so as not to reach the back surface, and then a protective tape is attached to the front surface of the wafer and the back surface of the wafer is ground to expose the bottom of the half-cut groove on the back surface, thereby dividing the wafer into individual device chips (see, for example, Patent Document 1).

Furthermore, a technology has been proposed in which a laser beam of a wavelength that is transparent to the wafer is irradiated from the front or back surface of the wafer at a focal point positioned inside the intended dividing line to form a modified layer inside the wafer along the intended dividing line, and then a protective tape is attached to the front surface of the wafer, and the back surface of the wafer is ground to form the wafer to the desired thickness, and the wafer is divided into individual device chips by the external force applied during the grinding (see, for example, Patent Document 2).

JP 2004-193241 A JP 2014-007333 A

On the back side of the device chips individually divided by the technology described in Patent Documents 1 and 2, a DAF (Die Attach Film) is provided, which is used when mounting and stacking the device chips on a substrate or the like. When providing a DAF on a device chip, the DAF is provided over the entire back side of the wafer, and a dicing tape is provided over the DAF. The outer periphery of the dicing tape is supported by a ring-shaped frame with an opening for accommodating the wafer, and the dicing tape is expanded to divide the DAF into individual device chips.

However, when performing a DAF division process in which the DAF is divided into individual device chips, the DAF may not be divided well to correspond to the device chips depending on the expansion speed and expansion amount when the dicing tape is expanded, the size of the device chip, etc., so conventionally, after performing the DAF division process, the division state of the DAF is confirmed with a microscope from the side of the division groove formed on the planned division line on the front surface of the wafer, and division conditions such as the expansion speed and expansion amount when expanding the dicing tape are adjusted as necessary. However, it is not easy to confirm the division state of the DAF arranged on the back side of the wafer from the side of the division groove formed on the front surface of the wafer, and it takes time to confirm the division state of the DAF, which results in a problem of poor productivity.

The present invention has been made in consideration of the above facts, and its main technical objective is to provide a method for checking DAF division that can easily check whether the DAFs arranged on the back surface of the wafer have been properly divided into chips.

In order to solve the above-mentioned main technical problem, according to the present invention, a DAF division confirmation method for confirming whether or not a DAF arranged on the back surface of a wafer has been properly divided into chips is provided, which includes arranging one surface of a DAF on the back surface of a wafer divided into a plurality of chips along a planned division line, or a wafer on which a division starting point is formed along a planned division line, positioning the wafer in an opening of an annular frame having an opening for accommodating the wafer, adhering a dicing tape to the other surface of the DAF, and supporting the DAF and wafer on the frame via the dicing tape. The method includes a support process for expanding the dicing tape between the wafer and the frame to expand the gap between adjacent chips and divide the DAF to correspond to the chips; a shrink process for heating the dicing tape between the wafer and the frame to shrink the slack; a dicing tape peeling process for arranging a support member on the surface of the wafer and peeling the dicing tape from the DAF; and a DAF division confirmation process for confirming whether the DAF has been divided to correspond to each chip.

If the DAF is not divided to correspond to each chip in the DAF division confirmation process, it is preferable to adjust the expansion speed and amount when expanding the dicing tape in the DAF division process.

The DAF division confirmation method of the present invention includes a support step in which one side of a DAF is disposed on the back surface of a wafer divided into a plurality of chips along a planned division line, or a wafer on which a division starting point is formed along a planned division line, the wafer is positioned in an opening of an annular frame having an opening for accommodating the wafer, a dicing tape is affixed to the other side of the DAF, and the DAF and wafer are supported on the frame via the dicing tape; a DAF division step in which the dicing tape between the wafer and the frame is expanded to expand the space between adjacent chips and the DAF is divided to correspond to the chips; and a DAF division step in which the wafer and the frame are aligned to each other. The process is composed of at least a shrinking process in which the dicing tape between the wafer and the DAF is heated to shrink any slack, a dicing tape peeling process in which a support member is placed on the surface of the wafer and the dicing tape is peeled off from the DAF, and a DAF division confirmation process in which it is confirmed whether the DAF has been divided to correspond to each chip. Since the wafer and DAF can be supported by the support member and the DAF side can be faced upward, it is possible to easily and reliably confirm from the side on which the DAF is placed whether the DAF has been properly divided to correspond to the chips, and this also makes it possible to properly adjust the division means in the DAF division process.

FIG. 2 is a perspective view showing a mode of forming a cutting groove or a division starting point in a wafer to be processed in this embodiment. 1 is a perspective view showing a manner in which a wafer on which cutting grooves or division starting points are formed is placed on a chuck table of a grinding machine. FIG. FIG. 2A is a perspective view showing how a wafer is divided into individual chips by a grinding device, and FIG. 2B is a perspective view of the wafer divided into individual chips. FIG. 11 is a perspective view showing an embodiment of a supporting step. FIG. 6 is a partially enlarged cross-sectional view showing an embodiment of a DAF dividing step performed by the dividing device shown in FIG. 5. FIG. 1 is a perspective view showing an embodiment of a shrink process. FIG. 13 is a perspective view showing an embodiment of a DAF division confirmation step. 10A is a perspective view showing another embodiment of a dicing tape peeling step, and FIG. 10B is a perspective view showing another embodiment of a DAF division confirmation step.

Below, an embodiment of the DAF division confirmation method configured based on the present invention will be described in detail with reference to the attached drawings.

When carrying out the DAF division confirmation method of this embodiment, a wafer divided into multiple chips along the planned division lines, or a wafer on which division starting points are formed along the planned division lines, is prepared. First, the procedure for preparing a wafer divided into multiple chips along the planned division lines will be described with reference to Figures 1 to 3. The upper part of Figure 1 shows an unprocessed wafer 10, which is the workpiece of this embodiment. This wafer 10 has multiple devices 12 formed on a surface 10a partitioned by planned division lines 14.

In order to divide the above-mentioned unprocessed wafer 10 into individual device chips along the planned division line 14, for example, as shown on the left side of FIG. 1, the unprocessed wafer 10 is transported to a cutting device 20 (only a part of which is shown) equipped with a cutting blade 22. The cutting device 20 includes a holding means for holding the wafer 10, a moving means for moving the holding means, and an imaging means for imaging the wafer 10 held by the holding means (all of which are omitted from the illustration), and the cutting blade 22 is rotated by a motor (not shown). The wafer 10 is held by the holding means, the moving means is operated to position the holding means directly under the imaging means, and the wafer 10 is imaged by the imaging means to perform alignment. Based on the position information of the planned division line 14 detected by the alignment, the planned division line 14 is aligned in the X direction in the figure. Next, the cutting blade 22 is positioned so as to be along a predetermined dividing line 14 on the front surface 10a side of the wafer 10, and the holding means and the cutting blade 22 are moved relatively in the X direction by the moving means to perform processing feed, and the cutting groove 100 is formed along the dividing line 14. As shown in the figure, the cutting groove 100 is a half-cut groove with a depth that does not reach the back surface 10b of the wafer 10. The depth of the cutting groove 100 is set to a depth at which the cutting groove 100 is exposed from the back surface 10b when the back surface 10b side is ground to the finished thickness in the wafer dividing process described later. By operating the above-mentioned cutting blade 22 and the moving means, the holding means holding the wafer 10 and the cutting blade 22 are appropriately moved relatively in the X direction, the Y direction perpendicular to the X direction, and the rotational direction, and the cutting groove 100 is formed along all the dividing lines 14 on the wafer 10, as shown in the lower left side of FIG. 1.

Next, as shown on the left side of FIG. 2, a BG (backgrind) tape T1 is attached to the front surface 10a of the wafer 10 to form an integrated unit. Once the wafer 10 and the BG tape T1 are integrated, they are transported to a grinding device 30 shown in the lower part of FIG. 2, and placed on a chuck table 31 consisting of a holding surface 32 and a frame 34 surrounding the holding surface 32, with the BG tape T1 side facing downward and the back surface 10b of the wafer 10 facing upward. The holding surface 32 of the chuck table 31 is made of a breathable material and is connected to a suction means (not shown), and the wafer 10 placed on the chuck table 31 is held by suction through the action of the suction means.

As shown in FIG. 3(a), the grinding device 30 includes a grinding means 36. The grinding means 36 is a means for grinding and thinning the back surface 10b of the wafer 10 held by suction on the chuck table 31, and includes a rotating spindle 362 rotated by a rotation drive mechanism (not shown), a wheel mount 364 attached to the lower end of the rotating spindle 362, a grinding wheel 366 attached to the lower surface of the wheel mount 364, and a plurality of grinding wheels 368 arranged in a ring shape on the lower surface of the grinding wheel 366.

After the wafer 10 is held by suction on the chuck table 31, the rotating spindle 362 of the grinding means 36 is rotated in the direction indicated by the arrow R1 in FIG. 3(a) at, for example, 6000 rpm, and the chuck table 31 is rotated in the direction indicated by the arrow R2 at, for example, 300 rpm. Then, while the grinding water supply means (not shown) supplies grinding water onto the back surface 10b of the wafer 10, the grinding feed means (not shown) is operated to lower the grinding means 36 in the direction indicated by the arrow R3 in the figure, so that the grinding wheel 368 comes into contact with the back surface 10b of the wafer 10, and the grinding wheel 366 is fed for grinding at a speed of, for example, 1 μm/sec. At this time, grinding can be carried out while measuring the thickness of the wafer 10 with a contact-type measuring gauge (not shown), and the back surface 10b side of the wafer 10 is ground by a predetermined amount until the thickness of the wafer 10 reaches the finished thickness. As described above, the front surface 10a of the wafer 10 has cut grooves 100 formed along the intended dividing lines 14 to a depth equivalent to the finished thickness. By grinding the rear surface 10b by a predetermined amount, the cut grooves 100 are exposed on the rear surface 10b of the wafer 10, as shown in FIG. 3(b), and the wafer 10 is divided into individual device chips 12' (wafer dividing process). Once the wafer 10 has been divided into individual device chips 12', the grinding means 36 is stopped and retracted upward.

As described above, the present invention is not limited to forming a cutting groove 100 on the front surface 10a side of the wafer 10 and grinding the back surface 10b side to divide the wafer 10 into individual device chips 12'. For example, a division origin forming step may be performed in which a division origin is formed along the planned division line 14 of the wafer 10 by laser processing, and an external force may be applied to the division origin to perform the wafer division step. Below, an embodiment in which a wafer division step is performed by performing a division origin forming step will be described with reference to Figures 1 to 3.

Once the unprocessed wafer 10 shown in the upper part of Fig. 1 has been prepared, it is transported to the laser processing device 40 shown on the right side of Fig. 1. The laser processing device 40 is equipped with a holding means for holding the wafer 10, a moving means for moving the holding means in the X direction, Y direction, and rotational direction in the figure, an imaging means for imaging the wafer 10 (all of which are omitted from the illustration), and a laser beam application means 41 for irradiating the wafer 10 with a laser beam LB having a wavelength that is transparent to the wafer 10.

The wafer 10 transported to the laser processing device 40 is sucked and held by the holding means with the back surface 10b facing upward. Although not shown, when the wafer 10 is held by the holding means, it is preferable to attach a protective tape to the front surface 10a of the wafer 10 in order to protect the device 12. The wafer 10 held by the holding means is positioned directly under the imaging means, and an alignment process is carried out. The imaging means irradiates infrared rays, captures the reflected infrared rays, converts them into electrical signals, and outputs them to a control means (not shown). By carrying out the alignment process, the position of the planned division line 14 formed on the front surface 10a of the wafer 10 is detected from the back surface 10b side of the wafer 10, and the moving means rotates the wafer 10 to align the planned division line 14 in a predetermined direction in the X direction.

Next, the moving means is operated to position the processing start position of the division line 14 directly below the condenser 42 of the laser beam application means 41, and the focal point of the laser beam LB is positioned inside the division line 14 of the wafer 10 and irradiated, while processing and feeding the wafer 10 in the X direction. As a result, as shown in FIG. 1, a division starting point 110 consisting of a modified layer is formed inside the wafer 10 along the predetermined division line 14. In this embodiment, as shown in the figure, the depth of the focal point is changed in three stages along the division line 14, and the laser beam LB is irradiated to form the division starting point 110 consisting of three modified layers. In this way, after the division starting point 110 is formed along the predetermined division line 14, the wafer 10 is indexed and fed in the Y direction by the interval of the division line 14, and the adjacent unprocessed division line 14 in the Y direction is positioned directly below the condenser 41. Then, in the same manner as described above, the focal point of the laser beam LB is positioned inside the dividing lines 14 of the wafer 10 and irradiated, and the wafer 10 is processed and fed in the X direction to form the dividing start points 110. In this manner, the wafer 10 is processed and fed in the X direction and the Y direction to form the dividing start points 110 along all the dividing lines 14 along the X direction. Next, the wafer 10 is rotated 90 degrees together with the chuck table 31 to align the unprocessed dividing lines 14 perpendicular to the dividing lines 14 on which the dividing start points 110 have already been formed in the X direction. Then, the focal point of the laser beam LB is positioned and irradiated to the remaining dividing lines 14 in the same manner as described above to form the dividing start points 110 along all the dividing lines 14 of the wafer 10 as shown in the lower right of FIG. 1 (dividing start point forming step). In addition, when forming a modified layer along the planned dividing line 14 of the wafer 10, the laser beam LB is not necessarily limited to being irradiated from the back surface 10b side of the wafer 10, and may be irradiated from the front surface 10a side of the wafer 10 if there is no test electrode or the like on the planned dividing line 14.

As described above, when the splitting starting points 110 are formed inside the wafer 10 along all the planned splitting lines 14, as shown on the right side of FIG. 2, the BG tape T1 is attached to the front surface 10a of the wafer 10 on which the splitting starting points 110 are formed, and the wafer is transported to the grinding device 30, and the BG tape T1 side is placed downward on the chuck table 31 of the grinding device 30 and suction-held. Thereafter, the back surface 10b side of the wafer 10 is ground by the grinding means 36 shown in FIG. 3 in the same procedure as the wafer splitting process described above. The back surface 10b side of the wafer 10 is ground by the grinding means 36 to thin the wafer 10 to the desired finished thickness, and an external force is applied to the splitting starting points 110, and the wafer 10 is broken along the splitting starting points 110 and split into individual device chips 12'. The present invention is not limited to forming a modified layer inside the planned dividing line 14 of the wafer 10 by the above-mentioned laser processing to form the dividing starting point 110, but may also irradiate a laser beam of an absorbent wavelength from the front surface 10a side of the wafer 10 to perform ablation processing along the planned dividing line 14 to form a laser processed groove that serves as the dividing starting point.

Next, as shown in FIG. 4, a supporting step is performed in which the wafer 10 is supported on a frame. When performing this supporting step, first, as shown in the lower part of FIG. 4, a circular sheet-like DAF 18 having the same dimensions as the wafer 10, a dicing tape T2, and an annular frame F having an opening Fa capable of accommodating the wafer 10 are prepared. The upper left part of FIG. 4 shows the wafer 10 divided into individual device chips 12' by the wafer dividing step described above, and the supporting step, DAF dividing step, shrinking step, and dicing tape peeling step described below will be described assuming that the wafer 10 divided into individual device chips 12' is supported on the frame F.

Once the wafer 10 divided into individual device chips 12' has been prepared, one surface 18a (top surface in the figure) of the DAF 18 is placed on the back surface 10b of the wafer 10. The back surface 10b side of the wafer 10 is positioned in the opening Fa of the frame F, and a dicing tape T2 is attached to the other surface 18b of the DAF 18. The DAF 18 and wafer 10 are supported on the frame F via the dicing tape T2, completing the supporting process. The BG tape T1 attached to the front surface 10a side of the wafer 10 is peeled off after the supporting process is performed.

After the above-mentioned supporting step is performed, the dicing tape T2 between the wafer 10 held by the frame F and the frame F is expanded to expand the space between adjacent device chips 12', and the DAF 18 is divided into pieces corresponding to the device chips 12'. With reference to FIG. 5, a dividing device 50 suitable for performing the DAF dividing step of this embodiment will be described. The dividing device 50 includes a frame holding means 51 that holds the frame F that supports the wafer 10 via the dicing tape T2 and the DAF 18, and a dividing means 52 that expands the dicing tape T2 attached to the frame F held by the frame holding means 51 and divides the DAF 18 arranged on the wafer 10 into pieces corresponding to the individual device chips 12'.

The frame holding means 51 includes a frame holding member 51a formed in an annular shape to hold the above-mentioned annular frame F, and a plurality of clamps 51b (four in the illustrated embodiment) as fixing means arranged at equal intervals around the outer periphery of the frame holding member 51a. The upper surface of the frame holding member 51a is formed flat, on which the frame F is placed. The frame F placed on the upper surface of the frame holding member 51a is then fixed to the upper surface of the frame holding member 51a by the clamps 51b.

An expansion drum 53 is disposed inside the frame holding member 51a, the lower end of which is fixed to a disk-shaped base 54. In a plan view, the expansion drum 53 is formed to be smaller than the inner diameter of the opening Fa of the frame F and larger than the outer diameter of the wafer 10 supported on the dicing tape T2 via the DAF 18. In the illustrated embodiment, the dividing means 52 is provided with a plurality (for example, four) of air cylinders 52a arranged around the expansion drum 53 and fixed to the base 54, and a piston rod 52b extending upward from the air cylinder 52a and connected at its upper end to the lower surface of the frame holding member 51a. Control air is supplied to the air cylinder 52a through a communication passage (not shown), and the piston rod 52b moves up and down due to the action of the air cylinder 52a, thereby moving the frame holding member 51a up and down.

The splitting device 50 of this embodiment has a configuration generally as described above, and the DAF splitting process of this embodiment will be described in more detail with reference to FIG. 6 in addition to FIG. 5.

When carrying out the DAF division process of this embodiment, as shown in FIG. 5, the front surface 10a side of the wafer 10 divided into individual device chips 12' is directed upward, and the frame F is placed on the upper surface of the frame holding member 51a of the division device 50 and fixed by the clamp 51b. At this time, the upper end of the expansion drum 53 is positioned at a reference position (shown by a solid line) that is approximately the same height as the upper surface of the frame holding member 51a, as shown in FIG. 6. Next, the air cylinders 52a of the multiple division means 52 connected to the frame holding member 51a are operated to retract the piston rods 52b into the air cylinders 52a, and the frame holding member 51a is lowered in the direction shown by the arrow R4. As a result, the frame F also descends together with the frame holding member 51a, and the dicing tape T2 supported by the frame F is expanded by a predetermined amount by the expansion drum 53 that rises relative to the frame holding member 51a (shown by a two-dot chain line), and a radial tensile force acts on the dicing tape T2. As a result, as shown in FIG. 6, the interval between adjacent device chips 12' on the wafer 10 is expanded, the DAF 18 is divided corresponding to the device chip 12', and the DAF division process is completed. In FIG. 6, for convenience of explanation, the vertical position of the wafer 10 is shown changed before and after dividing the DAF 18, but in the actual DAF division process, the vertical position of the wafer 10 is unchanged, and the vertical position of the frame holding member 51a changes. In addition, the pressure of the control air injected into the air cylinder 52a can be adjusted by an air supply source (not shown), and the expansion speed when expanding the dicing tape T2 can be adjusted to a desired expansion speed. In addition, the extension amount of the piston rod 52b can also be adjusted, and thus the expansion amount of the dicing tape T2 can also be adjusted to a desired amount.

After the above-mentioned DAF division process is performed, the frame F supporting the wafer 10 is carried out from the division device 50. At this time, the dicing tape T2 supporting the wafer 10 is in a loose state due to the above-mentioned DAF division process being performed. Therefore, as shown in FIG. 7, the heating means 60 is positioned near the dicing tape T2 exposed between the wafer 10 and the frame F. The heating means 60 is, for example, equipped with a heater and a blowing means, and is a means for spraying hot air from the tip to the outside. When the heating means 60 is positioned as shown in FIG. 7, hot air is sprayed from the heating means 60 and the frame F is rotated in the direction indicated by the arrow R5 to heat the entire area of the dicing tape T2 supporting the wafer 10. As a result, the slack in the dicing tape T2 between the wafer 10 and the frame F is shrunk (contracted), returning to a state substantially similar to the state before the above-mentioned DAF division process was performed, and the shrink process is completed.

As described above, after the shrink process is performed, as shown in FIG. 7, a support member T3 formed to the same dimensions as the wafer 10 is disposed on the front surface 10a of the wafer 10. The support member T3 is appropriately selected from, for example, a glass plate, a resin plate such as PET, or a resin tape. When disposing the support member T3 on the front surface 10a of the wafer 10, an adhesive is applied to the support surface on the support member T3 side. Once the support member T3 has been disposed on the front surface 10a of the wafer 10 in this manner, the dicing tape T2 is peeled off from the DAF 18 disposed on the back surface 10b of the wafer 10, completing the dicing tape peeling process.

In the above-mentioned supporting step, DAF dividing step, shrinking step, and dicing tape peeling step, the wafer 10 divided into individual device chips 12' is supported on the frame F in the supporting step, but the present invention is not limited to this. For example, in the supporting step, as shown in the upper right of FIG. 4, the back surface 10b of the wafer 10, which has a division starting point 110 formed along the division planned line 14 but has not been divided into individual device chips 12', may be disposed on one surface 18a of the DAF 18, and the DAF 18 and the wafer 10 may be supported on the frame F via the dicing tape T2. In that case, by performing the above-mentioned DAF dividing step, the wafer 10 is divided into individual device chips 12' and at the same time, the DAF 18 is divided corresponding to the device chips 12'. Therefore, in this case, it is possible to omit the wafer division process and carry out the DAF division process, and after carrying out the DAF division process, the shrink process and dicing tape peeling process can be carried out in the same manner as described above.

After the dicing tape peeling process is performed as described above, the wafer 10 sandwiched between the DAF 18 and the support member T3 is inverted as shown by the arrow R6 in FIG. 8 so that the surface on which the DAF 18 is disposed faces upward, and it is checked from the DAF 18 side whether the DAF 18 has been properly divided to correspond to the device chip 12'. Note that FIG. 8 shows a visual confirmation mode, but this is not necessarily limited to visual confirmation. It is also possible to position the wafer 10 directly under an imaging means (not shown) and check the image captured by the imaging means, or even to perform arithmetic processing on the captured image data, to check whether the DAF 18 has been properly divided to correspond to the device chip 12'. This completes the DAF division confirmation process.

Here, depending on the implementation conditions of the DAF division process described above, in the DAF division confirmation process, as shown in FIG. 8, it is confirmed that the DAF 18 is not completely divided corresponding to each device chip 12', and the DAF division process has not been performed properly. In such a case, it is considered that the expansion speed and expansion amount when expanding the dicing tape T2 in the DAF division process described above were not appropriate. Therefore, in consideration of the division result of the DAF 18 confirmed by the DAF division confirmation process described above, the expansion speed and expansion amount when expanding the dicing tape T2 by the division device 50 are appropriately adjusted. More specifically, the pressure of the control air injected into the air cylinder 52a of the division means 52 is increased, or the extension amount of the piston rod 52b is increased.

According to the above-described embodiment, in the DAF division confirmation process, the wafer 10 and DAF 18 can be supported by the support member T3 with the DAF 18 side facing upward, so that it is possible to easily and reliably check from the DAF 18 side whether the DAF 18 has been properly divided in correspondence with the device chip 12', and this also makes it possible to properly adjust the division means in the DAF division process.

In the above embodiment, as shown in FIG. 7, a support member T3 formed with the same dimensions as the wafer 10 is arranged on the front surface 10a side of the wafer 10, and then a dicing tape peeling process is performed to peel off the dicing tape T2 from the DAF 18 arranged on the back surface 10b side of the wafer 10, but the present invention is not limited to this. For example, as shown in FIG. 9(a), a support member T4 made of a resin tape larger than the opening Fa of the frame F and smaller than the outer shape of the frame F may be arranged on the front surface 10a side of the wafer 10 on which the DAF division process has been completed. More specifically, the support member T4 shown in FIG. 9(a) is prepared, and the roller 70 is rotated in the direction indicated by the arrow R7 while moving in the direction indicated by the arrow R8 to press the support member T4 against the front surface 10a of the wafer 10 and the frame F. Then, as shown in FIG. 9(b), the frame F is inverted, the dicing tape T2 side faces upward, and the dicing tape T2 is pulled in the direction indicated by the arrow R9 to peel off. As a result, the wafer 10 is supported by the support member T4, the DAF 18 disposed on the front surface 10a of the wafer 10 is exposed, and a DAF division confirmation step is performed to confirm whether the DAF 18 has been properly divided corresponding to the device chip 12' from the DAF 18 side, as described above.

In the above embodiment, when carrying out the DAF division confirmation method of this embodiment, a wafer 10 was prepared in which a plurality of devices 12 were partitioned by division lines 14 and formed on the surface 10a, but the present invention is not limited to this. The present invention also includes a case in which, for example, a so-called dummy wafer in which devices 12 are not formed on the surface is used, and a dummy wafer divided into a plurality of chips along the planned division lines when it is assumed that a plurality of devices 12 are formed on the surface, or a dummy wafer in which a division starting point is formed along the planned division lines is prepared as a workpiece, and the above-mentioned supporting step, DAF division step, shrinking step, and DAF division confirmation step are carried out. In this way, the DAF division confirmation method of this embodiment is carried out using a dummy wafer, and the expansion speed and expansion amount when expanding the dicing tape in the DAF division step are appropriately adjusted, thereby avoiding failure of the DAF division step using a regular wafer 10 and minimizing economic losses.

10: Wafer 10a: Front surface 10b: Back surface 12: Device 12': Device chip 14: Planned division line 18: DAF
20: Cutting device 22: Cutting blade 30 Grinding device 31: Chuck table 32: Holding surface 34: Frame 36: Grinding means 362: Rotating spindle 364: Wheel mount 366: Grinding wheel 368: Grinding stone 40: Laser processing device 41: Laser beam application means 42: Concentrator 50: Dividing device 51: Frame holding means 52: Dividing means 53: Extension drum 100: Cutting groove 110: Dividing starting point T1: BG tape T2: Dicing tape T3: Support member T4: Support member

Claims (2)

A method for checking whether a DAF provided on a back surface of a wafer is properly divided into chips, comprising:
a supporting step of disposing one surface of a DAF on a back surface of a wafer divided into a plurality of chips along a division line or a wafer on which division starting points are formed along the division line, positioning the wafer in an opening of an annular frame having an opening for accommodating the wafer, attaching a dicing tape to the other surface of the DAF, and supporting the DAF and the wafer on the frame via the dicing tape;
a DAF dividing step of expanding a dicing tape between the wafer and the frame to expand a space between adjacent chips and divide the DAF into chips;
a shrinking process in which the dicing tape between the wafer and the frame is heated to shrink the slack;
a dicing tape peeling step of disposing a support member on the front surface of the wafer and peeling the dicing tape from the DAF;
a DAF division confirmation step of confirming whether the DAF is divided into chips;
A DAF division confirmation method comprising at least the steps: The DAF division confirmation method according to claim 1, wherein, if the DAF is not divided to correspond to each chip in the DAF division confirmation process, the expansion speed and the expansion amount when expanding the dicing tape are adjusted in the DAF division process.

Images