JP6935131B2 - How to cut a plate-shaped workpiece - Google Patents

Description

The present invention relates to a cutting method for cutting a plate-shaped workpiece having a scheduled cutting line.

Lines to be cut are set in a grid pattern on a plate-shaped substrate such as a package substrate or a semiconductor wafer. A device is provided in each area partitioned by the planned cutting line. When the plate-shaped substrate provided with the device is cut along the planned cutting line, individual device chips are formed.

In order to cut a plate-shaped substrate such as a package substrate or a semiconductor wafer, for example, a cutting device is used to perform cutting. The cutting device includes a holding table (holding means) for holding a plate-shaped workpiece, an annular cutting blade including a cutting blade in which abrasive grains are embedded, and a spindle on which the cutting blade is mounted. Be prepared.

The cutting blade is mounted on the cutting device by inserting the spindle into a through hole formed in the center of the cutting blade. When cutting a work piece, the work piece is held on a holding table, and the spindle arranged parallel to the surface of the work piece is rotated to rotate the cutting blade. Then, the rotating work piece is cut along the planned cutting line into the work piece to cut the work piece.

In order to cut the plate-shaped workpiece, the cutting blade is positioned at a predetermined height position so that the lower end of the cutting blade of the cutting blade is lower than the lower surface of the workpiece, and cutting is performed. .. A dicing tape may be attached to the lower surface side of the plate-shaped workpiece before it is carried into the cutting device, and in that case, the cutting blade also cuts into the dicing tape. Further, the plate-shaped workpiece may be held on the holding table of the cutting device via a substrate (substraight), and in that case, the cutting blade also cuts into the substrate.

The dicing tape and the substrate cut into the cutting blade by the cutting process are discarded after the cutting process. Therefore, the dicing tape and the substrate are required for the number of the plate-shaped workpieces, which makes cutting extremely uneconomical.

Therefore, for example, in order to perform cutting without using dicing tape or the like, a jig table has been developed in which blade relief grooves having an array corresponding to a planned cutting line set on the plate-shaped workpiece are formed. (See Patent Document 1). In the cutting device, the plate-shaped workpiece is held on the jig table. At this time, the orientation and position of the plate-shaped workpiece are adjusted so that the blade relief groove of the jig table and the planned cutting line of the plate-shaped workpiece are aligned with each other.

When the plate-shaped workpiece is cut by a cutting blade, the cutting blade of the cutting blade enters the blade relief groove of the jig table, so that the jig table is not cut by the cutting blade. Since the jig table is reusable, economical cutting can be realized.

Japanese Unexamined Patent Publication No. 2011-49193

When the jig table is used when cutting a plate-shaped workpiece, it is necessary to use a jig table provided with a blade relief groove corresponding to a planned cutting line set for the plate-shaped workpiece. .. On the other hand, the scheduled cutting line set on the plate-shaped workpiece is variously set according to the shape and size of the device chip manufactured from the plate-shaped workpiece.

Therefore, it is necessary to prepare jig tables having different arrangements of blade relief grooves as many as the number of arrangements of the planned cutting lines to be set, which increases the cost of the jig table and is troublesome to manage the jig table. It caused a problem that it took.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a method for cutting a plate-shaped workpiece that does not require the disposal of dicing tape and does not require a jig table. ..

According to one aspect of the present invention, it is a cutting method for cutting a plate-shaped workpiece having a scheduled cutting line set, and the plate-shaped workpiece is placed on a holding table via a self-repairing member. A holding step of placing and holding the work piece on the holding table, and after performing the holding step, the work piece is cut by the cutter blade along the planned cutting line while being cut into the self-repairing member. A cutting step for cutting is provided , and the self-repairing member is arranged on the upper surface of the fixing jig. In the holding step, the workpiece is placed on the fixing jig and placed on the self-repairing member. the method for cutting plate-like workpiece, characterized in Rukoto placed on the holding table is provided in a contact state.

In one aspect of the present invention, before carrying out the cutting step, the workpiece held on the holding table is cut with a cutting blade along the planned cutting line to form a cutting groove, and the cutting groove is formed. A cutting step for forming an uncut portion under the cutting groove is further provided, and in the cutting step, the uncut portion may be cut by the cutter blade.

Further, in one aspect of the present invention, the workpiece is set with a plurality of intersecting scheduled cutting lines, and the workpiece has a plurality of chip regions partitioned by the scheduled cutting lines. A plurality of suction holes corresponding to each chip region may be formed in the self-repairing member and the fixing jig.

According to one aspect of the present invention, when cutting a plate-shaped workpiece along a planned cutting line, the plate-shaped workpiece is placed on a holding table via a self-repairing member, and the plate-shaped workpiece is placed on the holding table. A holding step of holding the plate-shaped workpiece is carried out. Then, the cutter blade is cut into the self-repairing member to cut the plate-shaped workpiece.

A groove is formed when the cutter blade is cut into the self-healing member. When the wall surfaces of the groove are brought into contact with each other, the bond between the two wall surfaces of the groove is reconstructed by the physical or chemical action of the substance contained in the member, and eventually the two wall surfaces are joined and the groove disappears. Therefore, after performing the cutting step to cut the plate-shaped workpiece, the self-repairing member can be used again when cutting another plate-shaped workpiece.

For example, when cutting a plate-shaped workpiece only with a cutting blade without using a cutter blade, when the cutting blade is cut into the self-repairing member, the self-repairing member partially becomes cutting chips. Will be removed. Therefore, the self-healing member cannot be reused due to irreparable damage to the self-healing member.

On the other hand, in one aspect of the present invention, since the cutter blade is cut into the self-repairing member, the amount of the self-repairing member removed is extremely small, and the self-repairing action of the self-repairing member can be sufficiently exhibited. Since the self-healing member can be reused, it is not necessary to prepare as many plate-shaped workpieces as the dicing tape or substrate (substraight) to be cut.

Therefore, the present invention provides a method for cutting a plate-shaped workpiece that does not require disposal of a dicing tape or the like and does not require a jig table.

FIG. 1A is a plan view schematically showing the front surface of the package substrate, and FIG. 1B is a plan view schematically showing the back surface of the package substrate. It is a perspective view which shows a part of the cutting apparatus schematically. FIG. 3 (A) is a side view schematically showing a first example of a cutter blade, and FIG. 3 (B) is a side view schematically showing a second example of a cutter blade, and FIG. 3 (C). ) Is a side view schematically showing a third example of the cutter blade. FIG. 4A is a cross-sectional view schematically showing a holding step, and FIG. 4B is a cross-sectional view schematically showing a cutting step. It is a perspective view which shows typically the wafer. It is a perspective view which shows typically the cutting apparatus. 7 (A) is a cross-sectional view schematically showing a holding step, FIG. 7 (B) is a cross-sectional view schematically showing a cutting step, and FIG. 7 (C) is a schematic view of a cutting step. It is a cross-sectional view shown in.

The plate-shaped workpiece according to the present embodiment of the method for cutting the plate-shaped workpiece will be described. The plate-shaped workpiece is, for example, a substrate made of a material such as silicon, SiC (silicon carbide), or other semiconductor, or a material such as sapphire, glass, or quartz. Alternatively, the plate-shaped workpiece is a package substrate in which the device is covered with resin. Hereinafter, a case where the plate-shaped workpiece is a package substrate will be described as an example.

FIG. 1A is a plan view schematically showing the front surface of the package substrate, and FIG. 1B is a plan view schematically showing the back surface of the package substrate. The package substrate 1 includes a metal frame 3 formed in a substantially rectangular shape in a plan view. The metal frame 3 is made of a metal such as 42 alloy (an alloy of iron and nickel) or copper.

As shown in FIG. 1B, a plurality of stages 5 are arranged on the back surface 1b side of the package substrate 1. Devices (not shown) such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are provided on the front side of the stages 5 (the surface 1a side of the package substrate 1) so as to overlap each stage 5. A resin 9 for sealing the device is disposed on the package substrate 1. The resin 9 is formed to have a predetermined thickness and protrudes from the metal frame 3 in the thickness direction. On each stage 5, the device is covered with resin 9.

A plurality of electrode pads 7 are arranged in a matrix around each stage 5. The front side of each electrode pad 7 is covered with the resin 9, and the back side is exposed. The electrode pad 7 is connected to each electrode of each device with a metal wire (not shown) or the like before the resin 9 is formed. The electrode pad 7 located between two adjacent devices is connected to the two adjacent devices. When individual device chips are formed by cutting the package substrate 1, the electrode pads 7 are divided into electrode terminals of the respective device chips.

A marker 11 is formed on the back surface 1b side of the package substrate 1. The marker 11 is used as a mark for aligning the position of the cutter blade at the time of cutting the package substrate 1 with a predetermined position. By cutting the cutter blade so as to divide the plurality of electrode pads 7 one after another between the pair of markers 11 and cutting the resin 9 together with the electrode pads 7 around each stage 5, each device chip can be formed. It is formed. That is, each row and column in which the plurality of electrode pads 7 are lined up is a scheduled division line.

Next, a cutting device for cutting the package substrate 1 will be described. FIG. 2 is a partially cutaway perspective view schematically showing the cutting device 2.

The cutting device 2 includes a holding table 6 on the upper surface of the device base 4 that supports each configuration. A suction portion 8 communicating with a suction source (not shown) is formed in the center of the holding table 6. The holding table 6 is reciprocating in the X-axis direction and is rotatably arranged.

The package substrate 1 is carried into the cutting device 2 in a state of being placed on the fixing jig (holding jig) 13, and is placed on the suction table 6. A self-healing member is arranged on the upper surface of the fixing jig 13, that is, the surface in contact with the package substrate 1. The self-repairing member is a member whose bond is repaired by the physical or chemical action of a substance contained in the member when the cut surfaces formed by the cutting are brought into contact with each other even if the member is cut with a sharp blade. be.

Japanese Unexamined Patent Publication No. 2008-239722 discloses an example of a self-repairing member. An example of the self-healing member is a crystalline polymer crosslinked body in which a large number of dungling chains are bonded to a polymer crosslinked structure. The crystalline polymer retains its material shape due to the polymer crosslinked structure. When the self-repairing member is damaged, the self-repairing action is exhibited by a topology interaction in which dungling chains invade and entangle with each other in and between molecules of the polymer crosslinked body to form a cohesive force. However, the self-healing member is not limited to this.

A plurality of suction holes (not shown) extending from the back surface to the front surface are formed in the fixing jig 13 and the self-repairing member. The suction holes are formed so as to correspond to each chip region partitioned by the planned cutting line of the package substrate 1. When the suction source is operated while the fixing jig 13 is placed on the holding table 6, a negative pressure acts on each chip region through the suction holes to suck the package substrate 1 onto the holding table 6. Be retained.

The cutting device 2 is provided with a cutting unit 10 having a cutter blade 14 mounted on the tip of a spindle 12 (see FIG. 4B). Further, an imaging camera (imaging means) 16 for detecting a line to be cut of the package substrate 1 to be cut is provided so as to be integrally movable with the cutting unit 10 in the Y-axis direction and the Z-axis direction. Alignment is performed by the imaging camera 16.

Next, the cutter blade 14 included in the dividing unit 10 will be described. The cutter blade is a thin steel plate blade, and is made of, for example, high-speed steel, cemented carbide obtained by sintering tungsten carbide, cobalt, nickel, or the like. As the cutter blade, for example, a cutter blade having a thickness of about 50 μm to 300 μm is used.

3 (A) to 3 (C) show an example of the cutter blade 14, respectively. As shown in FIGS. 3A to 3C, the cutter blades 14a, 14b, 14c are formed in an annular shape having a through hole 18 at the center. A spindle 12 (see FIG. 4B) is inserted into the through hole 18 and mounted on the cutting device 2.

The outer periphery of the cutter blades 14a, 14b, 14c is a cutting blade 20. When cutting a plate-shaped workpiece, the spindle 12 is rotated to rotate the cutter blades 14a, 14b, 14c, and the sharp cutting edge 20 is cut into the plate-shaped workpiece. .. The cutting edge 20 may be formed with, for example, a saw blade as shown in FIGS. 3 (A) to 3 (C). The number of saw blades formed is, for example, 40 or more and 150 or less over the entire circumference. The shape and number of each saw blade are appropriately selected according to the type of plate-shaped workpiece.

Next, each step of the method of cutting the plate-shaped workpiece according to the present embodiment will be described. In the method of cutting the plate-shaped workpiece, first, a holding step of holding the package substrate 1 on the holding table 6 of the cutting device 2 is performed. FIG. 4A is a cross-sectional view schematically showing the holding step.

In the holding step, the package substrate 1 is placed on the holding table 6 via the self-healing member 15. The self-healing member 15 is placed on the holding table 6 in advance, for example. By placing the package substrate 1 on the self-repairing member 15, the self-repairing member 15 can be arranged between the holding table 6 and the package substrate 1. Alternatively, the package substrate 1 is placed on the self-repairing member 15 in advance, and the self-repairing member 15 is placed on the holding table 6 so that the package substrate 1 is arranged between the holding table 6 and the package substrate 1. You may.

After the package substrate 1 is placed on the holding table 6 via the self-repairing member 15, the suction source of the holding table 6 is operated to generate a negative pressure. As described above, a plurality of suction holes are formed in the self-repairing member 15, and the negative pressure acts on the package substrate 1 through the suction holes. Then, the package substrate 1 is sucked and held on the holding table 6.

After performing the holding step, the holding table 6 is moved below the image pickup camera 16 so that the image pickup camera 16 takes an image of the package substrate 1. Then, the position of the marker 11 is recognized, and alignment is performed so that the cutter blade 14 can be cut along the scheduled cutting line in the cutting step described later.

Next, a cutting step is performed in which the cutter blade 14 is cut into the package substrate 1 and the package substrate 1 is cut along the planned cutting line. FIG. 4B is a cross-sectional view schematically showing the cutting step.

In the cutting step, first, the holding table 6 is moved below the cutting unit 10, and the holding table 6 is rotated so that the extension direction of the planned cutting line of the package substrate 1 matches the machining feed direction (X-axis direction). Then, the holding table 6 is moved so as to position the cutter blade 14 above the extension line of the planned cutting line of the package substrate 1.

Then, the spindle 12 of the cutting unit 10 is rotated to rotate the cutter blade 14. The cutting unit 10 is lowered so that the lower end of the cutting blade of the cutter blade 14 reaches a predetermined height position lower than the lower surface of the package substrate 1. Next, the holding table 6 is processed and fed so that the cutter blade 14 is cut into the package substrate 1. Then, the cutter blade 14 cuts the package substrate 1 along the planned cutting line.

After cutting the package substrate 1 along the planned cutting line, the holding table 6 is indexed and fed, and cutting by the cutter blade 14 is performed one after another to all the planned cutting lines lined up in one direction. The package substrate 1 is cut along the line. After that, the holding table 6 is rotated to switch the machining feed direction, and the package substrate 1 is cut along all the scheduled cutting lines arranged along the other directions.

By positioning the lower end of the cutting blade of the cutter blade 14 at a height lower than the lower surface of the package substrate 1, the package substrate 1 can be reliably cut by the cutter blade 14. However, the cutter blade 14 also cuts into the self-healing member 15. A groove is formed in the self-repairing member 15 cut into the cutter blade 14, and after the cutter blade 14 has passed, the self-repairing action of the self-repairing member 15 reconnects the connection between both wall surfaces of the groove. Formation begins. Eventually, when the reformation of the bond is completed and both wall surfaces are joined, the groove disappears.

Therefore, after each device chip formed by cutting the package substrate 1 is picked up from the self-repairing member 15, the self-repairing member 15 can be used when cutting a new package substrate 1.

When a general dicing tape or the like is used, the dicing tape must be prepared for the number of package substrates 1 to be cut, and the dicing tape must be discarded each time the package substrate 1 is cut. On the other hand, the cutting method according to the present embodiment is economical because the self-repairing member 15 can be used repeatedly. According to the present embodiment, there is provided a method for cutting a plate-shaped workpiece that does not require disposal of a dicing tape or the like.

Further, when using a jig table in which a blade relief groove corresponding to the arrangement of the planned cutting lines is formed, the jig table must be prepared for the number of patterns of the arrangement of the scheduled cutting lines. On the other hand, since the self-healing member 15 can be used for the package substrate 1 in which the cutting schedule lines of any arrangement are set, the trouble of managing a large number of the jig tables is not required. ..

The self-repairing member 15 may have a predetermined thickness in order to increase the strength of the self-repairing member 15 so that the self-repairing member 15 can withstand a plurality of uses, for example, the self-repairing member 15. The thickness of the repair member 15 is 1 mm or more. If the self-healing member 15 is too thin, the self-healing member 15 may be irreparably damaged when the device chip formed by cutting the package substrate 1 is picked up or the like.

In the above-described embodiment, the case where the package substrate 1 is cut as a plate-shaped workpiece has been described, but one aspect of the present invention is not limited to this. In the method for cutting a plate-shaped workpiece according to one aspect of the present invention, for example, a wafer on which a device is formed may be cut. Next, other embodiments of the present invention will be described.

A wafer, which is a plate-shaped workpiece to be cut in the embodiment, will be described with reference to FIG. FIG. 5 is a perspective view schematically showing the wafer 21. The surface 21a of the wafer 21 is partitioned into a plurality of regions by a plurality of scheduled cutting lines 23 arranged in a grid pattern, and a device 25 such as an IC is formed in each region partitioned by the plurality of scheduled cutting lines 23. Has been done.

The wafer 21 is cut along the scheduled cutting line 23 to form individual device chips. In the embodiment, the self-repairing member 15 described above is arranged on the back surface 21b of the wafer 21.

The wafer 21 may be attached to a tape-shaped self-repairing member 15 stretched through a through hole of an annular frame. In that case, the wafer 21, the annular frame, and the self-repairing member 15 are attached to each other. The wafer 21 is handled in the state of an integrated frame unit.

Next, the cutting device 22 that cuts the wafer 21 will be described. In the cutting cutting device 22, a cutting groove is formed by a cutting blade along a scheduled cutting line 23 of the wafer 21, and then a cutter blade is cut into the bottom of the cutting groove to cut the wafer 21.

FIG. 6 is a perspective view schematically showing the cutting device 22. A rectangular opening 24a is formed in the front corner of the device base 4, and a cassette support 26 that moves up and down is provided in the opening 24a. A cassette 28 accommodating a plurality of wafers 21 (frame units) is placed on the upper surface of the cassette support base 26. Note that FIG. 1 shows only the outline of the cassette 8 for convenience of explanation.

The cutting and cutting device 22 guides a transfer mechanism (not shown) in which the wafer 21 housed in the cassette 28 is taken out and placed on the holding table 34, and the transfer of the wafer 21 by the transfer mechanism. The transport rail 24d and the like are arranged.

A rectangular opening 24b long in the X-axis direction (front-rear direction, machining feed direction) is formed on the side of the cassette support base 26. Inside the opening 24b, an X-axis moving table 30, an X-axis moving mechanism (not shown) for moving the X-axis moving table 30 in the X-axis direction, and a dust-proof / drip-proof cover 32 covering the X-axis moving mechanism are provided. ..

The X-axis moving mechanism includes a pair of X-axis guide rails (not shown) parallel to the X-axis direction, and the X-axis moving table 30 is slidably attached to the X-axis guide rails. A nut portion (not shown) is provided on the lower surface side of the X-axis moving table 30, and an X-axis ball screw (not shown) parallel to the X-axis guide rail is screwed into the nut portion.

An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. By rotating the X-axis ball screw with the X-axis pulse motor, the X-axis moving table 30 moves in the X-axis direction along the X-axis guide rail.

A holding table 34 for holding the wafer 21 is provided above the X-axis moving table 30. The upper surface of the holding table 34 is a holding surface 34a for holding the wafer 21. The holding surface 34a is connected to a suction source (not shown) through a suction path (not shown) formed inside the holding table 34. When the wafer 21 is placed on the holding surface 34a and the suction source is operated to apply a negative pressure to the wafer 21 through the suction path, the wafer 21 is sucked and held by the holding table 34.

The holding table 34 is connected to a rotation drive source (not shown) such as a motor, and rotates around an axis perpendicular to the holding surface 34a. Further, the holding table 34 is machined and fed in the X-axis direction by the above-mentioned X-axis moving mechanism.

On the upper surface of the apparatus base 24, a cutting unit 36 and a gate-shaped support structure 40 for supporting the cutting unit 38 are arranged so as to straddle the opening 24b. Two sets of moving mechanisms 42a and 42b for moving the cutting unit 36 and the cutting unit 38 in the Y-axis direction (indexing feed direction) and the Z-axis direction are provided on the upper front surface of the support structure 40, respectively.

Each of the moving mechanisms 42a and 42b is provided with a pair of Y-axis guide rails 44 arranged in front of the support structure 40 and parallel to the Y-axis direction in common. The Y-axis moving plates 46a and 46b, which form the moving mechanisms 42a and 42b, are slidably attached to the Y-axis guide rail 44.

A nut portion (not shown) is provided on the back surface side (rear surface side) of each Y-axis moving plate 46a, 46b, and a Y-axis ball screw 48 parallel to the Y-axis guide rail 44 is provided in this nut portion, respectively. It is screwed. A Y-axis pulse motor 50 is connected to one end of each Y-axis ball screw 48. When the Y-axis ball screw 48 is rotated by the Y-axis pulse motor 50, the Y-axis moving plates 46a and 46b move in the Y-axis direction along the Y-axis guide rail 48.

A pair of Z-axis guide rails 52a and 52b parallel to the Z-axis direction are provided on the surfaces (front surfaces) of the Y-axis moving plates 46a and 46b, respectively. Z-axis moving plates 54a and 54b are slidably attached to the Z-axis guide rails 52a and 52b, respectively.

A nut portion (not shown) is provided on the back surface side (rear surface side) of each Z-axis moving plate 54a, 54b, and the nut portion is provided with a Z-axis ball screw 56a parallel to the Z-axis guide rails 52a, 52b. , 56b are screwed together. Z-axis pulse motors 58a and 58b are connected to one end of each Z-axis ball screw 56a and 56b, respectively.

If the Z-axis pulse motors 58a and 58b rotate the Z-axis ball screws 56a and 56b, respectively, the Z-axis moving plates 54a and 54b move in the Z-axis direction along the Z-axis guide rails 52a and 52b.

A cutting unit 36 is provided below the Z-axis moving plate 54a. The cutting unit 36 is configured in the same manner as the cutting unit 10 according to the above embodiment. The cutting unit 36 includes a spindle 68a (see FIG. 7C) that serves as a rotation axis, and an annular cutter blade 70a (see FIG. 7C) mounted on one end side of the spindle 68a. ..

A cutting unit 38 is provided below the Z-axis moving plate 54b. The cutting unit 38 includes a spindle 68b (see FIG. 7B) that serves as a rotation axis, and an annular cutting blade 70b (see FIG. 7B) mounted on one end side of the spindle 68b. The cutting blade 70b has a cutting grindstone containing abrasive grains on the outer periphery. The cutting blade 70b is thicker than the cutter blade 70a.

Further, an imaging camera (imaging unit) 60 for imaging the wafer 21 and the like is provided at a position adjacent to the cutting unit 36. When the wafer 21 is imaged using the image pickup camera (imaging unit) 60, alignment can be performed.

A circular opening 24c is formed at a position opposite to the opening 24a with respect to the opening 24b. A cleaning unit 62 for cleaning the wafer 21 and the like after cutting and cutting is provided in the opening 24c.

The cleaning unit 62 provided inside the opening 24c includes a cleaning table 64 that holds the wafer 21 and a cleaning nozzle that discharges cleaning liquid onto the wafer 21 from above the wafer 21 held by the cleaning table 64 (not shown). And. For example, the cleaning liquid is pure water.

Inside the cleaning table 64, a suction path (not shown) having one end communicating with the cleaning holding surface 66 on the upper surface of the cleaning table 64 is provided, and a suction source (not shown) is connected to the other end of the suction path. NS. When the wafer 21 is placed on the cleaning holding surface 66 of the cleaning table 64 and the suction source is operated to apply a negative pressure to the wafer 21, the wafer 21 is suction-held on the cleaning table 64. The cleaning table 64 is connected to a rotational drive source (not shown) and is rotatable about an axis perpendicular to the cleaning holding surface 66.

Next, each step of the method of cutting the plate-shaped workpiece according to the embodiment will be described. First, a holding step is performed in which the wafer 21 is placed on the holding table 34 via the self-repairing member 15 and the wafer 21 is sucked and held by the holding table 34. First, the wafer 21 is pulled out from the cassette 28 mounted on the cassette support base 26 by using a transfer mechanism (not shown), and the wafer 21 is placed on the holding surface 34a of the holding table 34.

For example, a self-healing member 15 is attached to the back surface 21b of the wafer 21 before the wafer 21 is housed in the cassette 28. Alternatively, the self-healing member 15 is placed on the holding surface 34a before the wafer 21 is placed on the holding table 34. In the holding step, the wafer 21 is held on the holding table 34 via the self-healing member 15. FIG. 7A is a cross-sectional view schematically showing the holding step.

Next, the cutting unit 38 and the holding table 34 are moved so as to position the holding table 34 below the cutting unit 38. At this time, the cutting blade 70b is positioned above the extension line of the scheduled cutting line so that the wafer 21 can be cut along the scheduled cutting line 23.

Then, the spindle 68b is rotated to rotate the cutting blade 70b, the holding table 34 is machined and fed in the X-axis direction, and the cutting blade 70b is cut into the wafer 21. FIG. 7B is a cross-sectional view schematically showing a cutting step.

After cutting along one scheduled cutting line 23, the holding table 34 is indexed and fed, and the wafer 21 is cut one after another along the scheduled cutting line 23 parallel to the scheduled cutting line 23. Then, the holding table 34 is rotated around an axis perpendicular to the holding surface 34a to change the machining feed direction, and the wafer 21 is cut along the remaining scheduled cutting lines.

In the cutting step, the cutting blade 70b is positioned at a predetermined height position so that the lower end of the cutting edge of the cutting blade 70b is higher than the back surface 21b of the wafer 21. Then, a cutting groove 27 (see FIG. 7C) is formed on the wafer 21 along the planned cutting line, and an uncut portion is formed under the cutting groove 27. In order to cut the wafer 21, the uncut portion must be removed.

For example, when the lower end of the cutting edge of the cutting blade 70b is positioned at a height lower than the back surface 21b of the wafer 21, the wafer 21 is cut by cutting, but the cutting blade 70b also cuts into the self-repairing member 15. Then, the self-repairing member 15 is partially cut, and the material constituting the self-repairing member 15 is removed as cutting chips.

The self-repairing member 15 is a member capable of regenerating the bond between the cut surfaces, but is not a member in which the removed portion is backfilled when partially removed. Therefore, the cut self-healing member 15 may not be suitable for reuse. Therefore, the cutting blade 70b is not cut into the self-repairing member 15, a cutting groove 27 is formed in the wafer 21, and an uncut portion 29 is left on the back surface 21b side of the cutting groove 27.

Next, a cutting step of cutting the wafer 21 along the scheduled cutting line 23 is performed by cutting the cut-out portion 29 below the cutting groove 27. In the cutting step, the cutter blade 70a of the cutting unit 36 is cut into the bottom of the cutting groove 27 formed along the planned cutting line 23 to cut the wafer 21.

First, the cutting unit 36 and the holding table 34 are moved so as to position the holding table 34 below the cutting unit 36. At this time, the cutter blade 70a is positioned above the extension line of the planned cutting line 23 so that the wafer 21 can be cut along the cutting groove 27.

Then, the spindle 68a is rotated to rotate the cutter blade 70a, the cutter blade 70a is lowered, and the holding table 34 is machined and fed in the X-axis direction to cut into the wafer 21. FIG. 7C is a cross-sectional view schematically showing the cutting step.

After cutting along one scheduled cutting line 23, the holding table 34 is indexed and fed, and the wafer 21 is cut one after another along the scheduled cutting line parallel to the scheduled cutting line 23. Then, the holding table 34 is rotated around an axis perpendicular to the holding surface 34a to change the machining feed direction, and the wafer 21 is cut along the remaining scheduled cutting lines.

When the cutting step is performed, the bottom portion of the cutting groove 27 formed in the cutting step, that is, the uncut portion 29 is cut by the cutter blade 70a. Then, the wafer 21 is divided into individual device chips.

In the cutting step, the cutting blade 70b is positioned at a predetermined height position so that the lower end of the cutting edge of the cutter blade 70a is at a lower height position than the back surface 21b of the wafer 21. Then, when the cutter blade 70a cuts into the uncut portion 29, the wafer 21 can be reliably cut.

Therefore, in the cutting step, the cutter blade 70a cuts into the self-repairing member 15. Even if the cutter blade 70a is cut into the self-repairing member 15, the amount of the self-repairing member 15 excluded as processing waste is extremely small.

A groove is formed in the self-repairing member 15 by the cutter blade 70a, and after the cutter blade 70a passes through, the self-repairing action of the self-repairing member 15 starts re-formation of the bond between both wall surfaces of the groove. Eventually, when the reformation of the bond is completed and both wall surfaces are joined, the groove disappears. Therefore, the self-healing member 15 can be used for cutting another wafer 21.

When the wafer 21 is to be cut only by the cutter blade 70a without using the cutting blade 70b, the processing load by the cutter blade 70a becomes large and the wafer 21 is liable to be damaged such as cracks. Further, when the wafer 21 is to be cut only by the cutting blade 70b without using the cutter blade 70a, the cutting blade 70b cuts into the self-repairing member 15 and damages the self-repairing member 15 so as not to be reusable.

Therefore, when cutting the wafer 21, a cutting step using the cutting blade 70b is performed to form the cutting groove 27, and a cutting step using the cutter blade 70a is performed to cut the bottom of the cutting groove 27. The remaining portion 29 is cut. Then, the processing load is reduced, and the self-repairing member 15 can be reused. In order to sufficiently reduce the machining load by the cutter blade 70a, for example, the depth of the cutting groove 27 is preferably larger than the thickness of the uncut portion.

In addition, the structure, method, etc. according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

1 Package substrate 1a, 21a Front surface 1b, 21b Back surface 3 Metal frame 5 Stage 7 Electrode pad 9 Resin 11 Marker 13 Fixed jig 15 Self-healing member 21 Wafer 23 Scheduled cutting line 25 Device 27 Cutting groove 29 Uncut part 2 Cutting device 4 , 24 Equipment base 6,34 Holding table 8 Suction unit 10,36 Cutting unit 12,68a, 68b Spindle 14,14a, 14b, 14c, 70a Cutter blade 16 Imaging camera 18 Through hole 20 Cutting edge 22 Cutting cutting device 24a, 24b, 24c Opening 24d Conveyance rail 26 Cassette support 28 Cassette 30 X-axis moving table 32 Dust-proof and drip-proof cover 34a Holding surface 38 Cutting unit 40 Support structure 42a, 42b Moving mechanism 44 Y-axis guide rail 46a, 46b Y-axis moving plate 48 Y-axis ball screw 50 Y-axis pulse motor 52a, 52b Z-axis guide rail 54a, 54b Z-axis moving plate 56a, 56b Z-axis ball screw 58a, 58b Z-axis pulse motor 60 Imaging camera (imaging unit)
62 Cleaning unit 64 Cleaning table 66 Cleaning holding surface 70b Cutting blade

Claims (3)

It is a cutting method that cuts a plate-shaped workpiece for which a planned cutting line is set.
A holding step of placing the plate-shaped workpiece on the holding table via a self-repairing member and holding the workpiece on the holding table.
After performing the holding step, a cutting step of cutting the workpiece with a cutter blade along the planned cutting line while cutting into the self-repairing member is provided .
The self-healing member is arranged on the upper surface of the fixing jig.
In the holding step, the workpiece is cut method of a plate-shaped workpiece, characterized in Rukoto placed on the holding table in contact with the self-healing member mounted on the solid Teiji tool. Before performing the cutting step, the workpiece held on the holding table is cut by a cutting blade along the planned cutting line to form a cutting groove, and the work piece is left uncut under the cutting groove. With additional cutting steps to form the part
The method for cutting a plate-shaped workpiece according to claim 1, wherein in the cutting step, the uncut portion is cut with the cutter blade. A plurality of intersecting scheduled cutting lines are set in the workpiece, and a plurality of intersecting scheduled cutting lines are set.
The workpiece has a plurality of chip regions partitioned by the planned cutting line.
The method for cutting a plate-shaped workpiece according to claim 1 or 2, wherein a plurality of suction holes corresponding to each chip region are formed in the self-repairing member and the fixing jig.

Images