JP7831971B2 - Chip manufacturing method - Google Patents

Description

This invention relates to a method for manufacturing chips by dividing a workpiece along a planned division line to produce multiple chips.

A workpiece, such as a package substrate, is divided into multiple regions by, for example, grid-like arrangements of division lines (streets), and a semiconductor device is formed in each of these regions. When such a workpiece is divided along these division lines, multiple chips, each containing a semiconductor device, are manufactured.

For dividing such package substrates, a cutting device is used that comprises, for example, a chuck table that holds the workpiece by applying suction force to the workpiece placed on the holding surface, and a cutting unit having a spindle with an annular cutting blade attached to its tip. In this cutting device, the workpiece is divided into multiple chips by rotating the cutting blade and bringing it into contact with the workpiece along the planned division line.

However, in order to divide a workpiece into multiple chips, the rotating cutting blade must penetrate the workpiece. In this case, there is a risk that the chuck table holding the workpiece may be damaged by being cut by the cutting blade.

Therefore, when dividing a workpiece into multiple chips in this manner, dicing tape is often attached to the workpiece, and the workpiece is held in place by this tape on the chuck table. This allows the workpiece to be divided into multiple chips while the outer edge of the cutting blade penetrating the workpiece is positioned inside the dicing tape. As a result, damage to the chuck table is prevented.

Furthermore, in this case, the dicing tape is not divided. Even after the workpiece is divided into multiple chips, the multiple chips remain integrated via the dicing tape. Therefore, the likelihood of some chips scattering during the division of the workpiece into multiple chips is reduced.

Such dicing tapes are consumables. Therefore, manufacturing chips using this method may increase chip manufacturing costs. In view of this, it has been proposed to divide a workpiece into multiple chips while the workpiece is held in a chuck table including a jig with a holding surface that directly holds the workpiece (see, for example, Patent Document 1).

Specifically, grooves (cutting blade relief grooves) are formed in the area of the jig's holding surface corresponding to the planned division lines of the workpiece. Furthermore, through-holes (eject holes) are formed in each of the multiple areas (chip-compatible areas) demarcated by these grooves, in order to apply suction force to both the workpiece and the individual chips.

Furthermore, when a cutting device is equipped with such a chuck table, the workpiece can be divided into multiple chips while the outer edge of the cutting blade penetrating the workpiece is positioned within the internal space of the groove. In this case, since the workpiece can be divided into multiple chips while suction force is applied to it through the through-hole, the likelihood of some chips scattering during this division process can be reduced.

Japanese Patent Publication No. 2007-273546

The chuck table, including the aforementioned jig, is a specialized item usable only for specific workpieces. That is, if the arrangement of the planned division lines on the workpiece does not correspond to the arrangement of the grooves formed on the jig, then the chuck table including that jig cannot be used to divide that workpiece.

Therefore, when a cutting device is equipped with a chuck table that includes jigs, it is necessary to prepare in advance a number of jigs corresponding to different types of workpieces with varying arrangements of planned cutting lines. This may increase the manufacturing cost of chips produced using this cutting device, and/or increase the time required for chip manufacturing.

In view of the above points, the object of the present invention is to suppress the increase in manufacturing costs and the prolongation of the time required for manufacturing chips produced in cutting equipment.

According to one aspect of the present invention, a cutting apparatus comprising a chuck table including a porous plate made of a first synthetic resin and having a holding surface for holding a workpiece, and a frame made of a second synthetic resin and surrounding the porous plate in such a manner that the holding surface of the porous plate is exposed, and a cutting unit having a spindle with an annular cutting blade attached to its tip, wherein a method for manufacturing a chip is to produce a plurality of chips by dividing the workpiece along a planned division line, comprising: a groove-forming workpiece holding step of holding a workpiece for groove formation on the holding surface of the porous plate included in the chuck table including the frame; a groove-forming step of forming a groove on the holding surface by rotating the first cutting blade and bringing the first cutting blade into contact with the porous plate along a region of the porous plate that is planned to overlap with the planned division line after the groove-forming workpiece holding step; a coating step of applying a resin to the holding surface to seal the inner surface of the groove after the groove-forming step; and after the coating step A method for manufacturing a chip is provided, comprising: a removal step of removing the groove-forming workpiece from the holding surface; a workpiece holding step of holding the workpiece on the holding surface after the removal step; and a splitting step of rotating a second cutting blade, which has a narrower cutting width than the first cutting blade, and bringing the second cutting blade into contact with the workpiece along the planned splitting line after the workpiece holding step, thereby splitting the workpiece into a plurality of chips, wherein in the groove-forming step, a groove is formed on the holding surface that penetrates the groove-forming workpiece and leads to the porous plate; in the coating step , the groove-forming workpiece functions as a mask to prevent the resin from being applied to areas of the holding surface other than the area where the groove is formed; the frame has a plurality of through holes formed therein; and the cutting unit further comprises a table base on which a plurality of grooves are formed and the frame is fixed by inserting and tightening a plurality of bolts into the plurality of through holes and the plurality of grooves, respectively .

According to another aspect of the present invention, a cutting apparatus comprising a chuck table including a porous plate made of a first synthetic resin and having a holding surface for holding a workpiece, and a frame made of a second synthetic resin and surrounding the porous plate in such a manner that the holding surface of the porous plate is exposed, and a cutting unit having a spindle with an annular cutting blade mounted at its tip, wherein a chip manufacturing method is provided for producing a plurality of chips by dividing the workpiece along a planned division line, wherein the first cutting blade is rotated and the first cutting blade is brought into contact with the porous plate along the region of the porous plate that is planned to overlap with the planned division line, thereby creating grooves in the holding surface. A method for manufacturing a chip is provided, comprising: a groove forming step of forming grooves; a coating step of applying a resin to the holding surface after the groove forming step to seal the inner surface of the grooves; a removal step of removing the resin applied to areas of the holding surface other than the area where the grooves are formed after the coating step; a workpiece holding step of holding the workpiece on the holding surface after the removal step; and a splitting step of splitting the workpiece into a plurality of chips by rotating a second cutting blade having a narrower cutting width than the first cutting blade and bringing the second cutting blade into contact with the workpiece along the planned splitting line after the workpiece holding step. Preferably, the frame has a plurality of through holes formed therein, and the cutting unit further comprises a table base having a plurality of grooves formed therein, and the frame is fixed by inserting and tightening a plurality of bolts into the plurality of through holes and the plurality of grooves, respectively.

In this invention, prior to dividing a workpiece to produce multiple chips, grooves are formed in the region of the porous plate that will overlap with the planned division lines of the workpiece, and then the inner surface of these grooves is sealed. Therefore, in this invention, a chuck table can be formed that includes a porous plate having a holding surface capable of holding both the workpiece and the multiple chips produced by dividing the workpiece.

Specifically, when a workpiece is held in place by this holding surface and then divided, an attractive force can be applied to the holding surface through areas other than those where grooves are formed in the porous plate. Furthermore, because the inner surface of these grooves is sealed, no attractive force is applied to the holding surface through the grooved areas of the porous plate. In other words, no leakage occurs when holding a workpiece or multiple chips in this holding surface.

Thus, in this invention, grooves corresponding to the arrangement of planned division lines set in the workpiece can be easily formed on the holding surface. As a result, it is possible to suppress increases in the manufacturing cost of chips produced in a cutting apparatus equipped with a chuck table including a porous plate having this holding surface, and to reduce the time required for chip manufacturing.

Figure 1 is a schematic perspective view showing an example of a cutting apparatus. Figure 2 is a schematic exploded perspective view showing an example of a table base and an example of a chuck table. Figure 3 is a schematic perspective view showing an example of a workpiece. Figure 4 is a flowchart schematically showing an example of a chip manufacturing method. Figure 5(A) is a schematic cross-sectional side view showing the workpiece holding step for groove formation; Figure 5(B) is a schematic cross-sectional side view showing the groove formation step; and Figure 5(C) is a schematic cross-sectional side view showing the chuck table, etc., after the coating step. Figure 6(A) is a schematic cross-sectional side view showing the chuck table, etc., after the removal step; Figure 6(B) is a schematic cross-sectional side view showing the workpiece holding step; and Figure 6(C) is a schematic cross-sectional side view showing the splitting step. Figure 7 is a flowchart schematically showing a modified example of the chip manufacturing method. Figure 8(A) is a schematic cross-sectional side view showing the groove formation step, and Figure 8(B) is a schematic cross-sectional side view showing the chuck table, etc., after the coating step. Figure 9 is a schematic cross-sectional side view illustrating the removal step.

The embodiments of the present invention will be described with reference to the attached drawings. Figure 1 is a schematic perspective view showing an example of a cutting apparatus used when dividing a workpiece to manufacture multiple chips. Note that the X-axis direction (front-back direction) and Y-axis direction (left-right direction) shown in Figure 1 are perpendicular to each other on the horizontal plane, and the Z-axis direction (up-down direction) is perpendicular to the X-axis and Y-axis directions (vertical direction).

The cutting apparatus 2 shown in Figure 1 has a base 4 that supports multiple components. An opening 4a extending along the X-axis direction is formed on the upper surface of the base 4. Inside this opening 4a are an X-axis moving table (not shown) and a table moving mechanism 6 that moves this X-axis moving table along the X-axis direction.

The table movement mechanism 6 includes, for example, a ball screw. The upper side of the X-axis moving table and the table movement mechanism 6 are covered by a table cover 8 and a bellows-shaped cover 10. Furthermore, a rectangular parallelepiped table base 12 is positioned on the X-axis moving table, exposed upward from the table cover 8.

This table base 12 is connected to a rotational drive source (not shown), such as a motor, and rotates around a straight line parallel to the Z-axis direction as its axis of rotation. The table base 12 also moves along the X-axis direction together with the X-axis moving table described above. Furthermore, a chuck table 14 for holding a rectangular workpiece is detachably mounted on the upper part of the table base 12.

Figure 2 is a schematic exploded perspective view showing the table base 12 and the chuck table 14. The table base 12 has a parallel upper surface 12a and lower surface 12b, with a rectangular parallelepiped recess 12c formed on the upper surface 12a. A cylindrical through-hole 12d is formed in the center of the table base 12, opening at the bottom surface of the recess 12c and the lower surface 12b.

Furthermore, this through-hole 12d communicates with a suction source such as an ejector. Additionally, the bottom surface of the recess 12c is provided with an inner wall 12e surrounding the through-hole 12d, with its upper surface lower than the upper surface 12a. Also, cylindrical grooves 12f, opening at the upper surface 12a, are formed near each of the four corners of the table base 12. These grooves 12f have spiral grooves (screw threads) formed on their sides.

The chuck table 14, mounted on the table base 12, has a rectangular parallelepiped frame 16. This frame 16 is made of a synthetic resin such as polyurethane (second synthetic resin) and has a parallel upper surface 16a and lower surface 16b. Furthermore, a rectangular parallelepiped recess is formed on the upper surface 16a side of the frame 16, defined by the bottom wall and side walls of the frame 16.

A rectangular porous plate 18 is fixed to a recess formed on the upper surface 16a of the frame 16. That is, the porous plate 18 is surrounded by the side walls of the frame 16, and its lower surface (not shown in Figure 2) faces the bottom wall of the porous plate 18. The upper surface (holding surface) 18a of the porous plate 18 is exposed and located on the same plane as the upper surface 16a of the frame 16.

Furthermore, the porous plate 18 is made of a porous synthetic resin (first synthetic resin) such as foamed polyurethane. The synthetic resin constituting the frame 16 and the porous synthetic resin constituting the porous plate 18 may be the same material or different materials.

Furthermore, a cylindrical through-hole (not shown) is formed in the central part of the frame 16, opening at the bottom surface and lower surface 16b of the recess of the frame 16. Therefore, the recess 12c and through-hole 12d of the table base 12 and the lower surface of the porous plate 18 are in communication with each other through the through-hole formed in the central part of the frame 16.

Furthermore, the upper surface 16a of the frame 16 has approximately the same shape as the upper surface 12a of the table base 12. Similarly, the lower surface 16b of the frame 16 has approximately the same shape as the lower surface 12b of the table base 12. In addition, cylindrical through-holes 16c, opening on the upper surface 16a and lower surface 16b, are formed near each of the four corners of the frame 16.

Furthermore, a spiral groove (screw groove) may be formed on the side surface of this through-hole 16c. Also, this through-hole 16c is provided so as to overlap with the groove 12f formed in the table base 12 when the table base 12 and the chuck table 14 are stacked so that the side surface of the table base 12 and the side surface of the chuck table 14 (the outer surface of the frame 16) are flush.

Then, with the table base 12 and the chuck table 14 stacked in this manner, inserting and tightening the bolts 20 into the through holes 16c and grooves 12f will fix the frame 16 to the table base 12. In other words, by tightening the bolts 20 in this way, the chuck table 14, which includes the frame 16, is mounted to the table base 12.

Furthermore, when the suction source communicating with the through-hole 12d is activated while the chuck table 14 is mounted on the table base 12, a suction force acts on the holding surface 18a of the porous plate 18 through the through-hole 12d, the recess 12c, and the porous plate 18. This allows the workpiece to be held on the holding surface 18a of the porous plate 18. Then, in the cutting device 2, the workpiece held on the holding surface 18a is divided to produce multiple chips.

Figure 3 is a schematic perspective view showing an example of a workpiece to be divided by the cutting device 2. This workpiece 11 is, for example, a package substrate obtained by encapsulating multiple devices with resin. The workpiece 11 shown in Figure 3 includes a rectangular parallelepiped substrate 13 having a surface 13a slightly wider than the holding surface 18a of the porous plate 18.

This substrate 13 is made of a metallic material such as 42 alloy (an alloy of iron and nickel) or copper, and includes a plurality of device regions 15 (in this case, three device regions 15) and an excess region 17 surrounding each of the plurality of device regions 15. Furthermore, each of the plurality of device regions 15 is divided into a plurality of regions (in this case, 16 regions) by grid-like arrangement of division lines 19.

Furthermore, multiple stages 21, demarcated by the division lines 19, are exposed on the surface 11a side of the workpiece 11. Around each of the multiple stages 21 (the area overlapping with the division lines 19), multiple metal layers (not shown) are arranged, insulated from each other by, for example, resin.

On the back surface 13b of each of the multiple stages 21, semiconductor devices (not shown) such as ICs (Integrated Circuits), LEDs (Light Emitting Diodes), or MEMS (Micro Electro Mechanical Systems) are mounted.

Furthermore, the electrodes of this semiconductor device and the metal layer surrounding the stage 21 are connected by metal wires (not shown), etc. A portion of this metal layer becomes the electrodes of each of the multiple chips obtained by dividing the workpiece 11.

Referring again to Figure 1, the remaining components of the cutting device 2 will be described. A gate-shaped support structure 22 is positioned on the upper surface of the base 4, straddling the opening 4a. A pair of cutting unit movement mechanisms 24 are provided on the front side of the support structure 22. The pair of cutting unit movement mechanisms 24 are located on the upper front surface of the support structure 22 and share a pair of Y-axis guide rails 26 that extend along the Y-axis direction.

The Y-axis guide rail 26 is mounted in such a manner that the Y-axis moving plates 28, each included in a pair of cutting unit moving mechanisms 24, can slide along the Y-axis direction. A nut portion (not shown) included in a ball screw is fixed to the back (rear) side of the Y-axis moving plate 28. A screw shaft 30, extending along the Y-axis direction, is connected to this nut portion in such a manner that it can rotate.

Furthermore, a Y-axis pulse motor 32 is connected to one end of the screw shaft 30. When the screw shaft 30 is rotated by this Y-axis pulse motor 32, the Y-axis moving plate 28 moves along the Y-axis direction. Additionally, a pair of Z-axis guide rails 34 extending along the Z-axis direction are arranged on the surface (front) of the Y-axis moving plate 28.

A Z-axis moving plate 36 is mounted on the Z-axis guide rail 34 in a manner that allows it to slide along the Z-axis direction. A nut portion (not shown) included in a ball screw is fixed to the back (rear) side of the Z-axis moving plate 36. A screw shaft 38 extending along the Z-axis direction is connected to this nut portion in a manner that allows it to rotate.

Furthermore, a Z-axis pulse motor 40 is connected to one end of the screw shaft 38. When the screw shaft 38 is rotated by this Z-axis pulse motor 40, the Z-axis moving plate 36 moves along the Z-axis direction. A cutting unit 42 is provided at the lower part of the Z-axis moving plate 36.

This cutting unit 42 has, for example, a cylindrical spindle housing. This spindle housing contains a spindle extending along the Y-axis direction and a rotational drive source, such as a motor, connected to the base end of the spindle. The tip of the spindle is exposed to the outside from the spindle housing.

A circular cutting blade 44 is mounted on the tip of the spindle, which is exposed to the outside from the spindle housing, via a blade mount. When the rotational drive source connected to the base end of the spindle operates, the cutting blade 44 rotates together with the spindle, using a straight line along the Y-axis as the axis of rotation.

This cutting blade 44 is a hub-type cutting blade, for example, in which an annular base made of metal or the like and an annular cutting edge along the outer edge of the base are integrally formed. The cutting edge of the hub-type cutting blade is obtained by fixing abrasive grains, for example, diamond or cubic boron nitride (cBN), with a bonding material such as nickel.

Furthermore, a washer-type cutting blade, consisting only of annular cutting edges, may be used as the cutting blade 44. A washer-type cutting blade (cutting edge) can be obtained, for example, by fixing abrasive grains made of diamond or cBN with a bonding material such as resin.

Furthermore, an imaging unit 46 is fixed to the lower part of the Z-axis moving plate 36, positioned adjacent to the cutting unit 42 in the X-axis direction. The imaging unit 46 includes, for example, a two-dimensional optical sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor sensitive to visible light, and an imaging lens.

Furthermore, if the Y-axis moving plate 28 of the cutting unit moving mechanism 24 is moved along the Y-axis direction, both the cutting unit 42 and the imaging unit 46 will move along the Y-axis direction. Similarly, if the Z-axis moving plate 36 of the cutting unit moving mechanism 24 is moved along the Z-axis direction, both the cutting unit 42 and the imaging unit 46 will move along the Z-axis direction.

Figure 4 is a schematic flowchart illustrating an example of a chip manufacturing method in which a workpiece 11 is divided along a planned division line 19 to produce multiple chips. Figures 5(A), 5(B), and 5(C), as well as Figures 6(A), 6(B), and 6(C), are schematic cross-sectional side views illustrating each step included in this method.

In this method, first, the groove-forming workpiece is held on the holding surface 18a of the porous plate 18 (groove-forming workpiece holding step: S1). Figure 5(A) is a schematic partial cross-sectional side view showing the groove-forming workpiece holding step (S1).

The groove-forming workpiece 23 has a rectangular parallelepiped shape similar to that of the workpiece 11. Furthermore, the groove-forming workpiece 23 is made of the same synthetic resin (e.g., polyurethane) as the material for the porous plate 18. Alternatively, the groove-forming workpiece 23 may be a protective tape such as polyolefin.

In this groove-forming workpiece holding step (S1), the groove-forming workpiece 23 is placed on the chuck table 14 so that the center of the holding surface 18a of the porous plate 18 coincides with the center of one surface 23a of the groove-forming workpiece 23. Then, the suction source communicating with the through hole 12d of the table base 12 is activated.

As a result, an attractive force acts on the holding surface 18a of the porous plate 18 through the through-hole 12d and recess 12c of the table base 12 and the porous plate 18. Consequently, the groove-forming workpiece 23 is held on the holding surface 18a of the porous plate 18.

Furthermore, if the groove-forming workpiece 23 is a protective tape, it can be attached to the holding surface 18a of the porous plate 18. Therefore, this is preferable because it eliminates the need to operate the suction source as described above. Also, this is preferable because it avoids the problem of the groove-forming workpiece 23 not being held due to leakage through the gap between the groove-forming workpiece 23 and the holding surface 18a.

Next, a groove is formed along the region of the porous plate 18 that is expected to overlap with the planned division line 19 of the workpiece 11, penetrating the groove-forming workpiece 23 and reaching the porous plate 18 (groove-forming step: S2). Figure 5(B) is a schematic partial cross-sectional side view showing the groove-forming step (S2). Prior to the groove-forming step (S2), a groove-forming cutting blade (first cutting blade) 44a is attached to the tip of the spindle 48 of the cutting unit 42.

In this groove-forming step (S2), first, the chuck table 14 is rotated so that the linearly extending portion of the porous plate 18 that is expected to overlap with the planned division line 19 of the workpiece 11 is parallel to the X-axis direction. Then, the chuck table 14 and/or cutting unit 42 are moved so that, in a plan view, this portion is positioned in the X-axis direction from the perspective of the groove-forming cutting blade 44a.

Next, the cutting unit 42 is lowered so that the lower end of the groove-forming cutting blade 44a is positioned lower than the holding surface 18a of the porous plate 18, and higher than its lower surface 18b. Then, while rotating the groove-forming cutting blade 44a via the spindle 48, the chuck table 14 is moved so that the groove-forming workpiece 23, the frame 16, and the porous plate 18 are in contact with the groove-forming cutting blade 44a from one end to the other in the X-axis direction.

This process cuts the groove-forming workpiece 23 and the porous plate 18, forming a linear groove 25 that penetrates the groove-forming workpiece 23 and extends into the porous plate 18. Then, the same operation is repeated to form grooves 25 in all areas of the porous plate 18 that are expected to overlap with the planned division line 19 of the workpiece 11.

Next, a resin is applied to the holding surface 18a of the porous plate 18 to seal the inner surface of the groove 25 formed on the holding surface 18a (coating step: S3). Figure 5(C) is a schematic partial cross-sectional side view showing the chuck table 14, etc., after the coating step (S3). Examples of resins used in the coating step (S3) include thermosetting resins such as polyurethane, epoxy resin, or melamine resin, or thermoplastic resins such as polypropylene or polyethylene.

In this coating step (S3), for example, a known spray gun is used to apply the resin to the groove 25. At this time, the resin is also applied to the area of the groove-forming workpiece 23 that is adjacent to the groove 25. This forms a resin film 27 that covers both the inner surface of the groove 25 and the area of the groove-forming workpiece 23 adjacent to the groove 25.

This resin film 27 seals the inner surface of the groove 25. The groove-forming workpiece 23 functions as a mask to prevent resin from being applied to areas of the holding surface 18a of the porous plate 18 other than the area where the groove 25 is formed (the area overlapping with the groove-forming workpiece 23). Therefore, the area of the holding surface 18a of the porous plate 18 that overlaps with the groove-forming workpiece 23 is not sealed.

Next, the groove-forming workpiece 23 is removed from the holding surface 18a of the porous plate 18 (removal step: S4). Figure 6(A) is a schematic partial cross-sectional side view showing the chuck table 14, etc., after the removal step (S4).

If the groove-forming workpiece 23 is held by suction, in this removal step (S4), the operation of the suction source communicating with the through-hole 12d of the table base 12 is stopped, and then the groove-forming workpiece 23 is removed from the chuck table 14. Furthermore, if the groove-forming workpiece 23 is a protective tape, in this removal step (S4), an external force is applied to separate the groove-forming workpiece 23 from the holding surface 18a.

Next, the workpiece 11 is held on the holding surface 18a of the porous plate 18 (workpiece holding step: S5). Figure 6(B) is a schematic partial cross-sectional side view showing the workpiece holding step (S5).

In this workpiece holding step (S5), the workpiece 11 is placed on the chuck table 14 so that the center of the holding surface 18a of the porous plate 18 aligns with the center of the back surface 11b of the workpiece 11. Then, the suction source communicating with the through hole 12d of the table base 12 is activated.

As a result, an attractive force acts on the holding surface 18a side through the through-hole 12d and recess 12c of the table base 12 and the porous plate 18, via the area of the porous plate 18 other than the area where the groove 25 is formed. Furthermore, since the inner surface of the groove 25 is sealed, no leakage occurs through the groove 25. Consequently, the workpiece 11 is held on the holding surface 18a of the porous plate 18.

Next, the workpiece 11 is divided into multiple chips (division step: S6). Figure 6(C) is a schematic partial cross-sectional side view showing the division step (S6). Prior to the groove forming step (S2), a workpiece cutting blade (second cutting blade) 44b, which has a narrower cutting width than the groove forming cutting blade 44a, is mounted on the tip of the spindle 48 of the cutting unit 42.

In this splitting step (S6), first, the chuck table 14 is rotated so that the linearly extending portion of the planned splitting line 19 of the workpiece 11 is parallel to the X-axis direction. Then, the chuck table 14 and/or cutting unit 42 are moved so that, in a plan view, this portion is positioned in the X-axis direction relative to the cutting blade 44b for the workpiece.

Next, the cutting unit 42 is lowered so that the lower end of the cutting blade 44b for the workpiece is positioned lower than the back surface 11b of the workpiece 11 and higher than the bottom surface of the groove 25. Then, while rotating the cutting blade 44b via the spindle 48, the chuck table 14 is moved so that the entire length of the workpiece 11, from one end to the other in the X-axis direction, is in contact with the cutting blade 44b.

This causes the workpiece 11 to be cut and divided along the linearly extending portion of the planned division line 19. At this time, the area where the groove 25 is formed in the porous plate 18 is exposed, but since the inner surface of this groove 25 is sealed, no leakage occurs through this groove 25. Next, the same operation is repeated to divide the workpiece 11 into multiple chips along the planned division line 19.

In the method shown in Figure 4, prior to dividing the workpiece 11 to produce multiple chips, a groove 25 is formed in the region of the porous plate 18 that is expected to overlap with the planned division line 19 of the workpiece 11, and then the inner surface of this groove 25 is sealed. Therefore, in this method, a chuck table 14 can be formed that includes a porous plate 18 having a holding surface 18a capable of holding both the workpiece 11 and the multiple chips produced by dividing the workpiece 11.

Specifically, when the workpiece 11 is held on the holding surface 18a and then divided, an attractive force can be applied to the holding surface 18a through areas other than those where the grooves 25 are formed in the porous plate 18. Furthermore, since the inner surface of the grooves 25 is sealed, no attractive force is applied to the holding surface 18a through the areas where the grooves 25 are formed in the porous plate 18. In other words, no leakage occurs when holding the workpiece 11 or multiple chips on the holding surface 18a.

Thus, in this method, grooves 25 corresponding to the arrangement of the planned division lines 19 set on the workpiece 11 can be easily formed on the holding surface 18a. As a result, it is possible to suppress increases in the manufacturing cost of chips produced in a cutting apparatus 2 equipped with a chuck table 14 that includes a porous plate 18 having this holding surface 18a, and to suppress increases in the time required for chip manufacturing.

The method described above is one aspect of the present invention, and the present invention is not limited to the method described above. For example, in the coating step (S3) of the present invention, the resin may be applied so as to fill the portion of the groove 25 located below the groove-forming workpiece 23. In this case, in the splitting step (S6), the resin filling the groove 25 may be cut together with the workpiece 11.

Furthermore, in this invention, the groove-forming workpiece 23 does not necessarily have to be used. Figure 7 is a schematic flowchart illustrating an example of such a chip manufacturing method. Figures 8(A), 8(B), and 9 are schematic partial cross-sectional side views illustrating each step included in this method.

In this method, first, a groove is formed on the holding surface 18a of the porous plate 18 along the region of the porous plate 18 that is expected to overlap with the planned division line 19 of the workpiece 11 (groove formation step: S10). Figure 8(A) is a schematic partial cross-sectional side view showing the groove formation step (S10). Prior to the groove formation step (S10), a groove-forming cutting blade (first cutting blade) 44a is attached to the tip of the spindle 48 of the cutting unit 42.

In this groove-forming step (S10), first, with the entire holding surface 18a of the porous plate 18 exposed, the chuck table 14 is rotated so that the linearly extending portion of the porous plate 18 that is intended to overlap with the planned division line 19 of the workpiece 11 is parallel to the X-axis direction. Then, the chuck table 14 and/or cutting unit 42 are moved so that, in a plan view, this portion is positioned in the X-axis direction from the perspective of the groove-forming cutting blade 44a.

Next, the cutting unit 42 is lowered so that the lower end of the groove-forming cutting blade 44a is positioned lower than the holding surface 18a of the porous plate 18, and higher than its lower surface 18b. Then, while rotating the groove-forming cutting blade 44a via the spindle 48, the chuck table 14 is moved so that the frame 16 and the porous plate 18, from one end to the other in the X-axis direction, are in contact with the groove-forming cutting blade 44a.

This process cuts the porous plate 18, forming a linear groove 29 on the holding surface 18a. Then, the same operation is repeated to form grooves 29 in all areas of the porous plate 18 that are expected to overlap with the planned division line 19 of the workpiece 11.

Next, a resin that seals the inner surface of the groove 29 formed on the holding surface 18a of the porous plate 18 is applied to the holding surface 18a (coating step: S20). Figure 8(B) is a schematic partial cross-sectional side view showing the chuck table 14, etc., after the coating step (S20). Examples of resins used in the coating step (S20) include thermosetting resins such as polyurethane, epoxy resin, or melamine resin, or thermoplastic resins such as polypropylene or polyethylene.

In this coating step (S20), for example, a known spray gun is used to apply the resin to the groove 29. At this time, the resin is also applied to the area of the holding surface 18a of the porous plate 18 located around the groove 29 (the peripheral area). This forms a resin film 31 that covers the inner surface of the groove 29 and the peripheral area. This resin film 31 seals the inner surface of the groove 29 and the peripheral area.

Next, the resin applied to the area of the holding surface 18a of the porous plate 18 other than the area where the groove 29 is formed (in this case, the area surrounding the groove 29) is removed (removal step: S30). This removal step (S30) is performed, for example, by grinding the holding surface 18a side of the porous plate 18 using a known grinding apparatus.

Figure 9 is a schematic partial cross-sectional side view showing the removal step (S30) performed in a known grinding apparatus. Specifically, in this removal step (S30), first, the chuck table 14 is removed from the table base 12 of the cutting apparatus 2. Next, a backgrind tape (BG tape) 33 is attached to the lower surface of the chuck table 14 (the lower surface 16b of the frame 16).

Next, the chuck table 14 is placed on the holding surface 52a of the chuck table 52 of the grinding device 50 via the BG tape 33. This chuck table 52 has a structure similar to, for example, the chuck table 14. Furthermore, the chuck table 52 is connected to a suction source (not shown) that applies suction force to the holding surface 52a, and a horizontal movement mechanism that moves the chuck table 52 along the horizontal direction.

Furthermore, a grinding unit 54 is provided above the chuck table 52. This grinding unit 54 is connected to a vertical movement mechanism that moves the grinding unit 54 along the vertical direction. The grinding unit 54 also has a cylindrical spindle 56 that extends along the vertical direction.

A disc-shaped mount 58 made of metal or the like is fixed to the tip (lower end) of the spindle 56. A rotational drive source (not shown), such as a motor, is connected to the base (upper end) of the spindle 56. When the rotational drive source connected to the base of the spindle 56 operates, the spindle 56 rotates around a straight line roughly parallel to the vertical as its axis of rotation.

Furthermore, an annular grinding wheel 60 is mounted on the underside of the mount 58. This grinding wheel 60 is fixed to the mount 58 using, for example, fasteners such as bolts (not shown). This mounts the grinding wheel 60 to the tip of the spindle 56 via the mount 58. When the spindle 56 rotates, the grinding wheel 60 mounted to its tip also rotates around a straight line roughly parallel to the vertical as its axis of rotation.

Furthermore, the grinding wheel 60 comprises a wheel base 62 and a plurality of grinding wheels 64 fixed to the lower surface of the wheel base 62. The wheel base 62 has an annular shape with an outer diameter approximately equal to the diameter of the mount 58, and is made of a metal such as stainless steel or aluminum, or a resin, for example.

Furthermore, the multiple grinding wheels 64 are arranged discretely along the circumferential direction of the grinding wheel 60 (wheel base 62). Each of the multiple grinding wheels 64 has a rectangular parallelepiped shape and contains abrasive grains, such as diamond or cBN (cubic Boron Nitride), and a binder (bonding material) that fixes these abrasive grains. For example, metal bonding, resin bonding, or vitrified bonding can be used as this binder.

Once the chuck table 14 is placed on the holding surface 52a of the chuck table 52 via the BG tape 33, the suction source connected to the chuck table 52 is activated. This holds the chuck table 14 on the holding surface 52a. Next, the chuck table 52 is moved so that the trajectories of the multiple grinding wheels 64, when the spindle 56 is rotated, are positioned directly above the center of the chuck table 14.

Next, while rotating both the chuck table 52 and the grinding wheel 60, the grinding unit 54 is lowered until the lower surfaces of each of the multiple grinding wheels 64 contact the resin film 31 provided on the chuck table 14. This grinds away and removes a portion of the resin film 31. Furthermore, while keeping both the chuck table 52 and the grinding wheel 60 rotating, the grinding unit 54 is lowered until all of the portion of the resin film 31 covering the area around the grooves 29 is removed.

Once the entire portion of the resin film 31 covering the area around the groove 29 has been removed, the chuck table 52 and the grinding wheel 60 are separated, and the operation of the suction source connected to the chuck table 52 is stopped. Next, the chuck table 14 is removed from the chuck table 52 of the grinding device 50 along with the BG tape 33. Then, the BG tape 33 is peeled off from the underside of the chuck table 14 (the underside 16b of the frame 16).

Next, the chuck table 14 is reattached to the table base 12 of the cutting device 2. Then, the workpiece 11 is held on the holding surface 18a of the porous plate 18 (workpiece holding step: S40), and the workpiece 11 is divided into multiple chips (dividing step: S50). Note that the workpiece holding step (S40) and the dividing step (S50) correspond to the workpiece holding step (S5) and the dividing step (S6) shown in Figure 4, respectively; therefore, a detailed explanation of these steps is omitted.

Furthermore, in the chip manufacturing method shown in Figure 7, after applying resin to the entire surface 18a of the porous plate 18 in the coating step (S20), the resin applied to areas other than those where the grooves 29 are formed on the surface 18a may be removed in the removal step (S30).

Furthermore, the structures and methods described in the above-mentioned embodiments can be modified as appropriate, as long as they do not deviate from the scope of the present invention.

2: Cutting device 4: Base (4a: opening)
6: Table movement mechanism 8: Table cover 10: Bellows-type cover 11: Workpiece (11a: Front surface, 11b: Back surface)
12: Table base (12a: top surface, 12b: bottom surface, 12c: recess)
(12d: through hole, 12e: inner wall, 12f: groove)
13: Substrate 14: Chuck table 15: Device area 16: Frame (16a: Top surface, 16b: Bottom surface, 16c: Through hole)
17: Surplus area 18: Porous plate (18a: upper surface (holding surface), 18b: lower surface)
19: Dividing line 20: Bolt 21: Stage 22: Support structure 23: Workpiece for groove formation 24: Cutting unit movement mechanism 25: Groove 26: Y-axis guide rail 27: Resin film 28: Y-axis movement plate 29: Groove 30: Screw shaft 31: Resin film 32: Y-axis pulse motor 33: Backgrind tape (BG tape)
34: Z-axis guide rail 36: Z-axis moving plate 38: Screw shaft 40: Z-axis pulse motor 42: Cutting unit 44: Cutting blade 46: Imaging unit 48: Spindle 50: Grinding device 52: Chuck table (52a: Holding surface)
54: Grinding unit 56: Spindle 58: Mount 60: Grinding wheel 62: Wheel base 64: Grinding wheel

Claims (3)

A cutting apparatus comprising a chuck table including a porous plate made of a first synthetic resin and having a holding surface for holding a workpiece, and a frame made of a second synthetic resin and surrounding the porous plate in such a manner that the holding surface of the porous plate is exposed, and a cutting unit having a spindle with an annular cutting blade mounted at its tip, wherein a method for manufacturing a chip is to divide the workpiece along a planned division line to produce a plurality of chips,
A groove-forming workpiece holding step, which involves holding a groove-forming workpiece on the holding surface of the porous plate included in the chuck table including the frame,
A groove-forming step is performed after the groove-forming workpiece holding step, by rotating the first cutting blade and bringing the first cutting blade into contact with the porous plate along the region of the porous plate that is to overlap with the planned division line, thereby forming a groove on the holding surface.
Following the groove forming step, a coating step is performed in which a resin that seals the inner surface of the groove is applied to the retaining surface.
Following the coating step, a removal step is performed to remove the groove-forming workpiece from the holding surface,
Following the removal step, a workpiece holding step is performed, in which the workpiece is held on the holding surface.
The process includes a workpiece holding step followed by a splitting step in which a second cutting blade, having a narrower cutting width than the first cutting blade, is rotated and brought into contact with the workpiece along the planned splitting line, thereby splitting the workpiece into the plurality of chips.
In the groove forming step, a groove is formed on the holding surface that penetrates the workpiece for groove formation and extends to the porous plate.
In the coating step, the groove-forming workpiece functions as a mask to prevent the resin from being applied to areas of the holding surface other than the area where the groove is formed .
Multiple through holes are formed in the frame.
A method for manufacturing a chip, characterized in that the cutting unit further comprises a table base having a plurality of grooves formed therein, and the frame is fixed by inserting and tightening a plurality of bolts into the plurality of through holes and the plurality of grooves, respectively . A cutting apparatus comprising a chuck table including a porous plate made of a first synthetic resin and having a holding surface for holding a workpiece, and a frame made of a second synthetic resin and surrounding the porous plate in such a manner that the holding surface of the porous plate is exposed, and a cutting unit having a spindle with an annular cutting blade mounted at its tip, wherein a method for manufacturing a chip is to divide the workpiece along a planned division line to produce a plurality of chips,
A groove forming step in which a groove is formed on the holding surface by rotating the first cutting blade and bringing the first cutting blade into contact with the porous plate along the region of the porous plate that is to overlap with the planned division line,
After the groove forming step, a coating step is performed in which a resin that seals the inner surface of the groove is applied to the retaining surface,
Following the coating step, a removal step is performed to remove the resin applied to areas of the retaining surface other than the area where the groove is formed.
Following the removal step, a workpiece holding step is performed, in which the workpiece is held on the holding surface.
A splitting step is performed after the workpiece holding step, by rotating a second cutting blade, which has a narrower cutting width than the first cutting blade, and bringing the second cutting blade into contact with the workpiece along the planned splitting line, thereby splitting the workpiece into the plurality of chips.
A method for manufacturing chips, characterized by comprising the following features. Multiple through holes are formed in the frame.
The method for manufacturing a chip according to claim 2, characterized in that the cutting unit further comprises a table base having a plurality of grooves formed therein, and the frame is fixed by inserting and tightening a plurality of bolts into the plurality of through holes and the plurality of grooves, respectively .