JP4540421B2 - Dicing method - Google Patents

Description

The present invention relates to a dicing method for removing burrs generated by cutting a workpiece with a cutting device.

  A cutting device such as a dicing device generally includes a chuck table that holds a workpiece such as a semiconductor wafer and a cutting unit on which an annular cutting blade is mounted. In this cutting apparatus, a workpiece can be cut and divided into a plurality of chips by moving a cutting blade rotated at a high speed while relatively cutting the cutting blade into the workpiece. For example, when the workpiece is a substantially disk-shaped semiconductor wafer, the semiconductor wafer is divided into a plurality of semiconductor chips by cutting along the streets (cutting lines) arranged in a lattice pattern on the surface of the semiconductor wafer. can do.

  By the way, when the workpiece is a semiconductor wafer in which metal foils such as copper, gold, and silver are laminated, when cut by a dicing machine, a plurality of whisker-like burrs (length of about 100 to 200 μm) are formed on both sides of the cutting groove. Will occur. This burr not only short-circuits or damages between layers and bonding, but also causes problems such as dropping and damaging adjacent circuits. Such burrs are considered to occur due to the property that the copper and the like are soft, highly viscous, and easily deformed.

  In order to cope with such burrs, Patent Document 1 discloses that a workpiece is cut by relatively moving the workpiece in a rotation direction and a forward direction of the cutting blade at a position where the cutting blade and the workpiece are opposed to each other. A deburring step of tracing the cutting groove formed in the cutting step by moving the workpiece in a direction opposite to the rotation direction of the cutting blade at a position where the cutting blade and the workpiece are opposed to each other; It is described to do.

JP 2001-77055 A

  In recent years, portable terminals such as mobile phones and PDAs have become widespread, and there has been a demand for smaller / thinner semiconductor chips. For this reason, in order to increase the accommodation rate of semiconductor chips, development of a substrate in which a plurality of bare chips are packaged on a film is in progress, and a substrate that can be mounted by folding a film has appeared.

  An example of such a package substrate is an SOF (System On Film) substrate in which a bare chip or peripheral circuit component is mounted on a film and sealed with a resin. Further, a CSP (Chip Size Package) substrate having an area array terminal structure in which solder balls are disposed on the back side of the film also includes a package substrate called a film CSP in which a bare chip is mounted on the film.

  Even when the film portion of these package substrates is cut with the cutting blade, burrs are generated, and the burrs adversely affect the quality of the chip and the subsequent production process. For example, in the case of a film CSP, when a divided chip is picked up by a collet, since there is a burr around the chip, the chip does not fit in the collet and cannot be picked up.

  Therefore, it was found that if the burrs generated when the film portion of the package substrate was cut by the technique described in Patent Document 1, the burrs generated at the corner portions of the divided chips could not be removed. did. This is presumed to be due to the fact that the material properties of the film, which is the source of burrs, are different from those of copper, gold, silver and the like.

  However, it is not impossible to remove burrs at all corners. Of the four corners of a rectangular chip, large burrs are generated at the two corners on the rear side of the cutting blade in the direction of cutting when cutting 2 channels. And it discovered that these two burrs could not be removed suitably.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to cut a workpiece in which a plurality of bare chips are packaged on a film into a lattice shape to cut a plurality of chips. It is an object of the present invention to provide a new and improved dicing method capable of suitably removing a burr generated at a corner portion of each chip when divided into two.

  In order to solve the above problems, according to another aspect of the present invention, a workpiece in which a plurality of bare chips are packaged on a film is cut from the film side surface by a cutting blade that rotates at high speed. Thus, a dicing method for dividing into a plurality of chips is provided. In this dicing method, (1) the workpiece is moved relative to the cutting blade in the rotation direction and forward direction of the cutting blade at a position facing the cutting blade and the workpiece, and the workpiece is moved in the first direction. Cutting at a predetermined interval to form a first cutting groove; and (2) cutting the workpiece in the rotation direction and forward direction of the cutting blade at a position where the cutting blade and the workpiece are opposed to each other. The workpiece is moved relative to the blade, and the workpiece is cut at a predetermined interval in a second direction orthogonal to the first direction to form a second cutting groove. A second step of dividing into chips; (3) by moving the workpiece relative to the cutting blade in a direction opposite to the rotation direction of the cutting blade at a position opposite to the cutting blade and the workpiece; By tracing the first cutting groove, the second of each tip A third burr that is sandwiched between the cutting blade and each tip is removed so that one of the burrs generated at the two corners on the rear side in the cutting direction is not released into the second cutting groove. (4) The workpiece is moved relative to the cutting blade in a direction opposite to the rotation direction of the cutting blade at a position where the cutting blade and the workpiece are opposed to each other, and the cutting blade is moved into the second cutting groove. A fourth step of removing the burrs generated at the other of the two corner portions by being sandwiched between the cutting blade and each chip so as not to escape into the first cutting groove by being relatively moved along It is characterized by including;

  With this configuration, in the first and second steps that are cutting steps, the work piece is cut into full chips and divided into chips, and then the third and fourth steps that are deburring steps are performed. Of these four corners, burrs generated at two corners on the rear side in the cutting direction in the second step can be suitably removed one by one without escaping to the orthogonal cutting grooves.

  In the cutting method, it is preferable that the moving direction of the cutting blade in the fourth step is the same as the moving direction of the cutting blade in the second step. As a result, burrs that could not be removed in the third step can be suitably removed by being sandwiched between the cutting blade and the tip in the fourth step without being released into the orthogonal cutting grooves.

  As described above, according to the present invention, burrs generated at the corner portions of each chip obtained by cutting at least a film portion of a workpiece into a lattice shape can be suitably removed without escaping to orthogonal cutting grooves. For this reason, the quality of the chip can be improved and the subsequent pick-up process can be executed without any trouble, so that the chip production process can be suitably executed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
First, based on FIG. 1, the whole structure of the dicing apparatus 10 comprised as an example of the cutting device concerning the 1st Embodiment of this invention is demonstrated. FIG. 1 is an overall perspective view showing a dicing apparatus 10 according to the present embodiment.

  As shown in FIG. 1, the dicing apparatus 10 moves, for example, a cutting unit 20 that cuts a workpiece, a chuck table 30 that holds the workpiece, and the cutting unit 20 and the chuck table 30 relative to each other. A moving mechanism (not shown).

  The cutting unit 20 includes a cutting blade, a spindle, and the like, and cuts the workpiece by cutting the workpiece into the workpiece while rotating the cutting blade at a high speed. The detailed configuration of the cutting unit 20 will be described later.

  The chuck table 30 holds and fixes a workpiece. The chuck table 30 has, for example, a vacuum chuck mechanism on the upper surface thereof, and can hold the workpiece by vacuum suction.

  Further, the moving mechanism includes, for example, a cutting unit moving mechanism and a chuck table moving mechanism (both not shown). Among them, the cutting unit moving mechanism moves the cutting unit 20 in a horizontal direction (Y-axis direction; spindle axial direction) orthogonal to the cutting direction (X-axis direction), and moves the cutting edge of the cutting blade to the workpiece. Each cutting line (street) can be aligned. The cutting unit moving mechanism can also adjust the cutting depth of the cutting blade with respect to the workpiece by moving the cutting unit 20 in the vertical direction (Z-axis direction). On the other hand, the chuck table moving mechanism can move the chuck table 30 and the workpiece held by the chuck table 30 in the cutting direction (X-axis direction).

  Here, based on FIG. 2, the film CSP board | substrate 50 which is an example of the to-be-processed object concerning this embodiment is demonstrated. As shown in FIG. 2, the film CSP substrate 50 is a package substrate having a rectangular shape, for example. The film CSP substrate 50 includes a film 54 as a base material and a package layer 55 formed on the film 54.

  The film 54 is a base material made of a synthetic resin such as plastic. The package layer 55 is a portion obtained by packaging a plurality of bare chips (not shown) regularly arranged vertically and horizontally on one surface of the film 54 (the lower surface in FIG. 2) with a synthetic resin. This bare chip is connected to a solder ball terminal (not shown) protruding on the other surface side of the film 54 via, for example, a wire, a copper wiring (not shown) or the like. In this way, the entire plurality of bare chips placed on the film 54 are molded with a synthetic resin and packaged. A CSP (Chip Size Package) is formed by dividing the packaged film CSP substrate 50 in this way. Note that a stacked CSP (high density package) in which a plurality of bare chips are stacked in one CSP may be used.

  In order to divide the film CSP substrate into individual CSP chips, streets 51 serving as cutting lines are arranged in a lattice pattern on the film CSP substrate 50. The street 51 includes a plurality of first streets 51a extending in the first direction and a plurality of second streets 51b extending in a second direction perpendicular to the first direction. A plurality of rectangular areas 52 are partitioned by the lattice-shaped streets 51, and the CSP is formed in each of the rectangular areas 52. Moreover, the peripheral part 56 in which CSP is not formed exists in the edge part of the film CSP board | substrate 50. FIG.

  Further, such a film CSP substrate 50 is mounted on the chuck table 30 of the dicing apparatus 10 after being placed on a mounting jig 60 as shown in FIG. The mounting jig 60 is made of, for example, a metal plate and has a rectangular shape that is somewhat larger than the film CSP substrate 50. At the center of the upper surface of the mounting jig 60, cutting blade escape grooves 61 are arranged in a lattice pattern, and a plurality of rectangular regions 62 are defined by these grooves 61. The rectangular area 62 corresponds to each of the rectangular areas 52 of the film CSP substrate 50, and the dimensions of the rectangular area 62 in the plan view are substantially the same as the dimensions of the rectangular area 52.

  In addition, a suction hole 63 that penetrates is formed in each of the rectangular regions 62, and suction grooves (not shown) that communicate with all the suction holes 63 are formed on the back surface of the mounting jig 60. ing. The film CSP substrate 50 is placed on the mounting jig 60 so that the rectangular regions 52 and 53 are aligned. At this time, as shown in FIG. 2, the film CSP substrate 50 is placed on the mounting jig 60 with the back surface (the surface on the film 54 side) facing upward. This is because the solder ball terminal protrudes from the surface on the film 54 side, and when placed on the mounting jig 60 with the surface on the film 54 facing downward, the film CSP substrate 50 cannot be placed flat. This is because the vacuum adsorption cannot be suitably performed.

  The mounting jig 60 on which the film CSP substrate 50 is thus placed is placed on the chuck table 30 shown in FIG. The chuck table 30 has a rectangular suction disk 31 larger than the mounting jig 60, and vacuum suction is performed from an opening 32 of a suction tube formed at the center of the suction disk 31, so that the film CSP substrate 50 is placed. The attached mounting jig 60 is vacuum-sucked. As a result, the film CSP substrate 50 is held by vacuum suction on the chuck table 30 via the mounting jig 60.

  When the film CSP substrate 50 is vacuum-sucked in this manner, the chuck table 30 moves in the X-axis direction to position the film CSP substrate 50 below the imaging means 40 in order to align the film CSP substrate 50. By imaging the surface of the film CSP substrate 50 by the imaging means 40 and analyzing the captured image, the arrangement state of the film CSP substrate 50 and the position of the street 51 can be confirmed, and the position and rotation of the chuck table 30 in the X direction. Adjust the position of angle, inclination, etc. The image of the imaging means 40 is also displayed on the monitor 42 and confirmed by the operator.

  After completion of such alignment, the chuck table 30 moves in the X-axis direction, and the film CSP substrate 50 is positioned below the cutting unit 20. Next, the cutting unit 20 and the chuck table 30 are moved relative to each other in the cutting direction (X-axis direction) while the cutting blade of the cutting unit 20 is rotated at a high speed and cut into the film CSP substrate 50. The first channel (that is, all streets 51a in the first direction) is cut. This cutting is performed, for example, by fixing the cutting unit 20 and reciprocating the chuck table 30 in the X-axis direction. However, the present invention is not limited to this example, and the chuck table 30 can be fixed and the cutting unit 20 can be reciprocated in the X-axis direction for cutting.

  When the cutting of the first channel is finished, the chuck table 30 is rotated 90 degrees, and then the second channel of the film CSP substrate 50 (that is, all the streets 51b in the second direction) is cut as described above. The Thereby, the film CSP substrate 50 is cut into a lattice shape and divided into a plurality of CSP chips.

  The first and second channel cutting processes as described above may be full cut or half cut. Full cutting is a cutting method in which the cutting depth of the cutting blade is set to be equal to or greater than the thickness of the workpiece, and the workpiece is completely cut in one cut. On the other hand, half cut is a cutting method in which the cutting depth of the cutting blade is set to be less than the thickness of the workpiece, and the same portion of the workpiece is cut stepwise by multiple times (for example, twice). is there.

  Next, based on FIG. 3, the structure of the cutting unit 20 concerning this embodiment is demonstrated. FIG. 3 is a perspective view showing the cutting unit 20 according to the present embodiment.

  As shown in FIG. 3, the cutting unit 20 mainly includes, for example, a flange 21, a cutting blade 22, a spindle 24, a spindle housing 26, a cutting water supply nozzle 28, and a foil cover 29.

  The cutting blade 22 is, for example, a very thin cutting grindstone (so-called washer blade) having a ring shape, and is formed by electroforming diamond abrasive grains. The cutting blade 22 is pivotally attached to the spindle 24 while being sandwiched from both sides by the flange 21, for example. The spindle 24 is a rotating shaft for transmitting a rotational driving force such as an electric motor (not shown) to the cutting blade 22 and rotates the mounted cutting blade 22 at a high speed of, for example, 30,000 rpm. . The spindle housing 26 is provided so as to cover the spindle 24, and supports the spindle 24 so as to be rotatable at high speed by an air bearing mechanism provided therein. Further, the cutting water supply nozzle 28 is configured as cutting water supply means for supplying cutting water near the processing point. The cutting water supply nozzle 28 is detachably provided on both sides of the lower side of the cutting blade 22, for example, and cools by cutting the cutting water toward the cutting blade 22 and the processing point. Further, the foil cover 29 is provided so as to cover the outer periphery of the cutting blade 22, and prevents scattering of cutting water, chips, and the like.

  The cutting unit 20 having such a configuration can perform cutting by rotating the cutting blade 22 at a high speed by the rotational driving force of the spindle 24 and cutting the cutting blade 22 into the film 54 side surface of the film CSP substrate 50. Thereby, an extremely thin cutting groove (kerf) can be formed along the cutting line (street 51) of the film CSP substrate 50.

  Next, a dicing method according to the present embodiment using the dicing apparatus 10 having the above configuration will be described with reference to FIGS. FIG. 4 is a flowchart showing the dicing method according to the present embodiment. 5A to 5D are plan views showing cutting states of the film CSP substrate 50 in each step of the dicing method according to the present embodiment. 5A to 5D indicate the traveling direction of the cutting blade 22 relative to the film CSP substrate 50.

  As described above, the film CSP substrate 50 is placed on the chuck table 30 with the surface on the film 54 side facing upward, since the solder balls protrude from the surface (back surface) on the film 54 side, and the package layer 55 The side surface (surface) is adsorbed and held. For this reason, at the time of cutting, cutting is performed by cutting the cutting blade 22 from above into the surface on the film 54 side.

  As shown in FIG. 4, the dicing method according to this embodiment includes first to fourth steps. This dicing method employs a half-cut method. For example, the film CSP substrate 50 is cut stepwise by two steps of cutting and divided into chips.

  The first and second processes are the first cutting process of the half cut. In the first and second steps, the film CSP substrate 50 is cut into a lattice shape in the first and second directions from the surface on the film 54 side at a predetermined depth of cut, and at least the film 54 portion is formed in a grid shape. Dicing. The first and second steps are performed by down-cutting.

  As shown in FIG. 6A, the downcut is performed by moving the film CSP substrate 50 in the rotational direction and the forward direction of the cutting blade 22 at a position where the cutting blade 22 and the film CSP substrate 50 face each other. In this method, the CSP substrate 50 is cut. The reason why this down cut is adopted in the first and second steps is as follows. In other words, in the first and second steps, if the cutting blade 22 is turned up in the reverse direction, burrs are generated toward the upper surface of the film 54, so that the burrs tend to increase. , Force acts in such a direction as to peel off the film 54 and the bare chip. For this reason, in the 1st and 2nd process which is the cutting process of the 1st step of a half cut, an up cut is not suitable and a down cut is suitable.

  On the other hand, the third and fourth steps include a half-cut second cutting step of cutting the uncut portion of the film CSP substrate 50 in the first and second steps, and the first and second steps. This process also serves as a deburring process for removing the burrs generated in step 1. The third and fourth steps are performed by up-cutting.

  As shown in FIG. 6B, the upcut is performed by moving the film CSP substrate 50 in a direction opposite to the rotation direction of the cutting blade 22 at a position where the cutting blade 22 and the film CSP substrate 50 face each other. In this method, the CSP substrate 50 is cut. The reason why this upcut is adopted in the third and fourth steps is that the cutting blade 22 rotating in the opposite direction to the burr generated in the first and second steps due to the downcut is opposite. This is because the burr can be suitably removed by applying a large force from the side. This high burr removal performance is supported by past experimental data.

  Hereinafter, each of the first to fourth steps will be described in detail.

  First, in step S11, which is the first step, as shown in FIG. 5A, the film CSP substrate 50 is half-cut parallel to the first direction at a predetermined interval by the down-cut, and a plurality of first cutting grooves are formed. 71 is formed (step S11: first step).

  Specifically, in this step S11, the plurality of first streets 51a (first channels) extending in the first direction of the film CSP substrate 50 are moved in one direction (left in FIG. 5A) by the cutting blade 22 that rotates down-cut. To the right). Note that the cutting direction in the first step is not necessarily one direction, and may be an arbitrary direction for each street 51a. Further, as shown in FIG. 6A, the cutting depth of the cutting blade 22 is a predetermined depth that cuts at least the film 54 portion of the film CSP substrate 50 and does not cut the entire film CSP substrate 50. is there. By such cutting, a plurality of first cutting grooves 71 parallel to the first direction are formed on the surface of the film CSP substrate 50 on the film 54 side.

  Next, in step S12, which is the second step, as shown in FIG. 5B, the film CSP substrate 50 is parallel to the second direction perpendicular to the first direction at a predetermined interval by the downcut. And a plurality of second cutting grooves 72 are formed (step S12: second step).

  Specifically, in step S12, first, the chuck table 30 is rotated by 90 degrees, and the extending direction (second direction) of the first street 51b of the film CSP substrate 50 is changed to the cutting direction (X-axis direction). Align. Next, the plurality of second streets 51b (second channel) extending in the second direction are cut in one direction (from bottom to top in FIG. 5B) by the cutting blade 22 that rotates down-cut. The cutting direction of each second street 51b may be the reverse direction (from the top to the bottom in FIG. 5B) as long as it is the same direction. Further, as shown in FIG. 6A, the cutting depth of the cutting blade 22 is a predetermined depth that cuts at least the film 54 portion of the film CSP substrate 50 and does not cut the entire film CSP substrate 50. Yes, substantially the same depth as the first step. By such a cutting process, a plurality of parallel second cutting grooves 72 are formed on the surface of the film CSP substrate 50 on the film 54 side.

  Through the first and second steps as described above, the first channel and the second channel of the film CSP substrate 50 are cut. As a result, at least the film 54 is diced into a lattice shape and divided into a plurality of chips 53. However, since there are uncut portions along both the cutting grooves 71 and 72, the entire film CSP substrate 50 has a plurality of pieces. It is not divided into chips.

  When the cutting process in the first and second steps is completed, as shown in FIG. 5B, among the four sides of each of the substantially rectangular chips 53 into which the film portion 54 is divided, the cutting in the second step is performed. Particularly large burrs 81 and 82 are generated at the corners at both ends of one side (the lower side 53a in FIG. 5B) located on the rear side in the direction. As shown in FIG. 7A, the burrs 81 and 82 at the corner portions are formed by tangling the cut portions of the film 54 into a plurality of threads, and are generated on each side of the chip 53. Very long and thick compared to. The burrs 81 and 82 extend in the direction opposite to the cutting direction in the second step (downward in FIG. 7A) according to the rotation direction of the cutting blade 22 by the down cut after the second step. Yes.

  Such large burrs 81 and 82 generated at the corner portion of the lower side 53a of each chip 53 cause the chip 53 to not be properly picked up in a pickup process, which is a subsequent process, and thus are required to be removed. According to the experiment result by the inventor of the present application, as shown in FIG. 7A, a large burr is generated at the corner of one side (upper side) located in front of the cutting direction in the second step of each chip 53. I know I won't. Therefore, regarding the removal of burrs at the corners of each chip 53, only the burrs 81 and 82 generated at both corners of the lower side 53a described above may be considered.

  By the way, it is difficult to remove the burrs 81 and 82 generated at the corners of the chips 53 as described above. This is because, even if the burrs 81 and 82 are removed by tracing the cutting groove 71 or 72 with the cutting blade 22, the burrs 81 and 82 escape to the cutting grooves 72 or 71 in the orthogonal direction. For example, when the first cutting groove 71 is traced by the cutting blade 22 to remove the burrs 81 and 82, either one of the burrs 81 and 82 is formed in the second cutting groove 72 orthogonal to the first cutting groove 71. Will run away. Therefore, in order to reliably remove the corner burrs 81 and 82, it is necessary to prevent the burrs 81 and 82 from escaping into the cutting grooves 71 or 72 in the direction orthogonal to each other. Therefore, in the following third and fourth steps, the burrs 81 and 82 generated at both corners of the lower side 53a of each chip 53 are driven one by one so as not to escape into the orthogonal cutting grooves, and surely. The removal method is adopted.

  Next, in step S13, which is the third step, as shown in FIG. 5C, the film CSP substrate is cut up by the cutting blade 22 along the first cutting groove 71 generated in the first step. 50 is cut in the first direction, and one of the burrs 81 and 82 generated at the corner of each chip 53 is removed (step S13: third step).

  Specifically, each cutting groove 22 as shown in FIG. 5C has a cutting depth that penetrates the film CSP substrate 50 by the cutting blade 22 rotated up-cut as shown in FIG. 6B. 71 is traced in one direction (from right to left in FIG. 5C). This completely cuts the uncut portion (the lower portion of the first cutting groove 71) other than the film 54 half-cut in the first step, and at the same time, burrs 81 at both corners of the lower side 53 a of the chip 53, One burr 82 located on the rear side in the moving direction of the cutting blade 22 (the burr 81 at the right end corner in FIG. 5C) is removed.

  The removal of the burr 81 at one corner will be described in detail. As shown in FIG. 7 (b), by tracing the first cutting groove 71 from the right to the left with the cutting blade 22, the large burr 81 at the right end corner of the lower side 53a of the chip 53 becomes the first cutting groove. The second cutting groove 72 perpendicular to 71 cannot escape and is sandwiched between the side surface 22 a of the cutting blade 22 and the lower side 53 a of the chip 53 and removed. At the same time, small burrs generated at locations other than the corners on both sides of the first cutting groove 71 (the lower side 53a and the upper side 53b of the chip 53) are also removed in contact with the cutting blade 22. On the other hand, the large burr 82 at the left end corner of the lower side 53a of the chip 53 can escape to the second cutting groove 72 even if the cutting blade 22 acts, and remains without being removed. However, since this burr 82 comes into contact with the cutting blade 22 in the third step and is pushed out from the first cutting groove 71 into the second cutting groove 72, it can be removed in the next fourth step. Become.

  Note that the moving direction of the cutting blade 22 in this third step does not have to be one direction from right to left for all the first cutting grooves 71 as described above. For example, all the first cutting grooves 71 The groove 71 may be moved in one direction from left to right. In this case, the burr 82 generated at the left end corner of the lower side 53a of the chip 53 can be removed, but the burr 81 generated at the right end corner remains. Further, the moving direction of the cutting blade 22 in the third step does not necessarily have to be one direction for all the first cutting grooves 71, and any direction (right to left, Or from left to right). In this case, any burr 81 or 82 located behind the cutting blade 22 in the moving direction remains for each first cutting groove 71.

  Thereafter, in step S14 as the fourth step, as shown in FIG. 5D, the cutting is performed along the second cutting groove 72 generated in the second step in the same direction as the cutting direction in the second step. Upcut by the blade 22. As a result, the film CSP substrate 50 is cut in the second direction to completely divide the entire film CSP substrate 50 into rectangular chips 53, and among the burrs 81 and 82 generated at the corners of the chips 53. The burrs that have not been removed in the third step are removed (step S14: fourth step).

  Specifically, each cutting groove 22 has a cutting depth that penetrates the film CSP substrate 50 by the cutting blade 22 rotated up-cut as shown in FIG. 6B, as shown in FIG. 5D. 72 is traced in one direction (from bottom to top in FIG. 5D). This completely cuts the uncut portion (lower portion of the second cutting groove 72) other than the film 54 half-cut in the second step, and at the same time, burrs 81 at both corner portions of the lower side 53a of the chip 53. , 82, the other burr that was not removed in the third step (the burr 82 at the left end corner in FIG. 5D) is removed.

  The removal of the burr 82 at the other corner will be described in detail. As shown in FIG. 7 (c), by tracing the second cutting groove 72 from below with the cutting blade 22, the large burr 82 at the left end corner of the lower side 53a of the chip 53 becomes the second cutting groove. The first cutting groove 71 orthogonal to 72 cannot escape and is sandwiched and removed between the side surface 22 a of the cutting blade 22 and the left side 53 c of the tip 53. At the same time, small burrs generated at locations other than the corners on both sides of the second cutting groove 72 (the left side 53c and the right piece 53d of the chip 53) are also removed in contact with the cutting blade 22.

  As described above, in the fourth step, the burr 82 that has escaped and remained in the second cutting groove 72 in the third step escapes again to the first cutting groove 71 perpendicular to the moving direction of the cutting blade 22. The traveling direction of the cutting blade 22 is set so that the corner where the burr 82 remains is positioned behind the traveling direction of the cutting blade 22. The traveling direction of the cutting blade 22 set in this way is the same direction as the cutting direction in the second step, and is the direction from the bottom to the top in the example of FIG.

  That is, in order to sandwich and remove the remaining corner burr 82 in the first cutting groove 71 so as not to escape, the burr to be removed of each chip 53 on the front side in the traveling direction of the cutting blade 22 is removed. The film CSP substrate 50 may be arranged so that the corner where the 82 exists is positioned, and up-cut.

  As described above, in the third step, the traveling direction of the cutting blade 22 may be any direction from right to left or from left to right, but in any case, it remains without being removed. The burr 81 or 82 is pushed into the second cutting groove 72. Therefore, in the fourth step, the remaining burrs 81 or 82 can be sandwiched and removed by the cutting blade 22 tracing the second cutting groove 72 in the same direction as the second step.

  As described above, in the dicing method according to the first embodiment, the burrs 81 and 82 generated in the two corner portions of the chip 53 are half-cut by half-cutting the film CSP substrate 50 (first stage). It can be removed reliably by up-cutting that also serves as the second stage of cutting.

(Second Embodiment)
Next, a dicing method according to the second embodiment of the present invention will be described. Compared with the dicing method according to the first embodiment, the dicing method according to the second embodiment is (1) the point that the film CSP substrate 50 is diced by full cut instead of half cut, and (2) third. And the fourth step is only a deburring process, and the other functional configuration is substantially the same as the dicing method according to the first embodiment. Omitted.

  Here, a dicing method according to the second embodiment using the dicing apparatus 10 having the above-described configuration will be described with reference to FIG. FIG. 8 is a flowchart showing the dicing method according to the second embodiment.

  As shown in FIG. 8, first, in step S21 as the first cutting process, the film CSP substrate 50 is fully cut in parallel in the first direction at a predetermined interval by the above-described downcut, and a plurality of first cuts are performed. A groove 71 is formed (step S21: first step).

  Next, in step S22, which is the second cutting process, the film CSP substrate 50 is fully cut in parallel in the second direction at a predetermined interval by the downcut, and a plurality of second cutting grooves 72 are formed ( Step S22: Second step).

  In such first and second processes, the cutting depth of the cutting blade 22 is a depth at which the film CSP substrate 50 can be completely cut by one cutting process. Therefore, the first cutting groove 71 and the second cutting groove 72 are formed so as to penetrate the film CSP substrate 50. Therefore, the entire film CSP substrate 50 is completely divided into a plurality of chips 53 by the first and second steps. Even in this case, the above-described large burrs 81 and 82 are formed at the two corners on the rear side in the cutting direction of the second step of each chip 53 by down-cutting the film 54 portion of the film CSP substrate 50. Each occurs.

  Further, in step S23, which is the first deburring process, the cutting blade 22 up-cuts along the first cutting groove 71 generated in the first process, so that it is generated at the corner of each chip 53. Any one of the burrs 81 and 82 is removed (step S23: third step).

  Specifically, the first cutting grooves 71 are traced in one direction, for example, by the cutting blade 22 rotated up-cut. As a result, one of the burrs 81 and 82 at the two corners of each chip 53 on the rear side in the direction of travel of the cutting blade 22 cannot escape into the second cutting groove 72 orthogonal to the cutting blade. It is sandwiched between the blade 22 and the chip 53 and removed. On the other hand, the other burr escapes into the second cutting groove 72 and remains.

  Thereafter, in step S24 which is a second deburring process, the cutting blade 22 up-cuts along the second cutting groove 72 generated in the second process in the same direction as the cutting direction of the second process. As a result, the burrs that have not been removed in the third step among the burrs 81 and 82 generated at the corners of the chips 53 are removed (step S24: fourth step).

  Specifically, each of the second cutting grooves 72 is traced in one direction by the cutting blade 22 rotated up-cut. Accordingly, the other burr that has not been removed in the third step among the burrs 81 and 82 at the two corners of each chip 53 cannot escape into the first cutting groove 71 that is orthogonal, so that cutting is performed. It is sandwiched between the blade 22 and the chip 53 and removed.

  As described above, in the dicing method according to the second embodiment, the film CSP substrate 50 is fully cut, so that the burrs 81 and 82 generated at the corners of the chip 53 are removed after the full cut. It is possible to remove it surely.

  The dicing method according to the first and second embodiments has been described above. According to such a dicing method, the film 54 portion of the film CSP substrate 50 is diced into a plurality of chips 53 and divided into a plurality of chips 53 in the first and second steps. The large burrs 81 and 82 are sandwiched between the cutting blade 22 and the tip 53 so as not to escape into the cutting groove 71 or 72 perpendicular to the traveling direction of the cutting blade 22 in the third and fourth steps. It can be reliably removed one by one.

  For this reason, in the subsequent pick-up process, the pick-up of the chip 53 by the collet is not hindered by the presence of a large burr, so that the chip 53 can be picked up smoothly. Further, the quality of the chip 53 can be improved by removing the burrs.

  Furthermore, in the first embodiment, the third and fourth steps serve not only as a burr removal step but also as a second half cutting step, so that the dicing step can be made more efficient.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to this example. It will be obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, in the said embodiment, although the example of the film CSP board | substrate 50 was mentioned and demonstrated as a to-be-processed object, it is not limited to this example. The workpiece may be, for example, a SOF (System On Film) substrate, a TCP (Tape Carrier Package) substrate, or the like as long as it is a substrate in which a plurality of bare chips are packaged on a film.

  In the above embodiment, the cutting blade 22 is moved from the bottom to the top in the second step to form the second cutting groove 72, but the present invention is not limited to this example. For example, in the second step, the second cutting groove 72 may be formed by moving the cutting blade 22 from top to bottom. In this case, large burrs are generated at the corners at both ends of the upper side 53b of the chip 53. For this reason, the moving direction of the cutting blade 22 in the third step may be either the left or right direction, but in the fourth step, the moving direction of the cutting blade 22 is changed from the same top to the bottom as in the second step. Thus, the burr can be removed.

  Theoretically, if the rotation direction of the cutting blade 22 is changed, the combinations of the traveling directions of the cutting blade 22 in each of the above processes further increase. For example, a method is conceivable in which the third and fourth steps for removing burrs are down-cut instead of the above-mentioned up-cut. However, the experimental results show that there is no data at all when trying to remove burrs by downcutting, which is inappropriate.

  Moreover, although the said embodiment demonstrated the example which remove | eliminates the burr | flash 81 and 82 which arose at the both ends corner of the chip | tip 53 which divided | segmented the film 54 part of the film CSP board | substrate 50, this invention is limited to this example. Not. The burr removing method of the present invention can be applied, for example, when removing a burr generated at an arbitrary corner of the chip when the substrate having the various films is cut into a rectangular chip.

  The present invention can be applied to a dicing method using a cutting device, and in particular, can be applied to a dicing method capable of suitably removing burrs generated when a film portion of a package substrate is cut.

1 is an overall perspective view showing a dicing apparatus according to a first embodiment of the present invention. It is a perspective view which shows the film CSP board | substrate which is an example of the to-be-processed object concerning the embodiment, and a mounting jig. It is a perspective view which shows the cutting unit concerning the embodiment. It is a flowchart which shows the dicing method concerning the embodiment. It is a top view which shows the cutting state of the film CSP board | substrate in the 1st process of the dicing method concerning the embodiment. It is a top view which shows the cutting state of the film CSP board | substrate in the 2nd process of the dicing method concerning the embodiment. It is a top view which shows the cutting state of the film CSP board | substrate in the 3rd process of the dicing method concerning the embodiment. It is a top view which shows the cutting state of the film CSP board | substrate in the 4th process of the dicing method concerning the embodiment. It is a side view which shows the positional relationship of the cutting blade and film CSP board | substrate for demonstrating the downcut concerning the same embodiment, and an upcut. It is an enlarged plan view which shows the cutting state of the film CSP board | substrate in each process of the dicing method concerning the embodiment. It is a flowchart which shows the dicing method concerning the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Dicing apparatus 20: Cutting unit 22: Cutting blade 24: Spindle 30: Chuck table 50: Film CSP board | substrate 53: Tip 54: Film 60: Mounting jig 71: 1st cutting groove 72: 2nd cutting groove 81 , 82: Bali

Claims (1)

A dicing method in which a workpiece in which a plurality of bare chips are packaged on a film is cut from the surface on the film side by a high-speed rotating cutting blade and divided into a plurality of chips:
The workpiece is moved relative to the cutting blade in a rotation direction and a forward direction of the cutting blade at a position facing the cutting blade and the workpiece, and the workpiece is set in a first direction. A first step of cutting at intervals to form a first cutting groove;
The workpiece is moved relative to the cutting blade in a rotational direction and a forward direction of the cutting blade at a facing position between the cutting blade and the workpiece, and the workpiece is moved in the first direction. A second step of cutting at a predetermined interval in a second direction perpendicular to the surface to form a second cutting groove and dividing the workpiece into a plurality of chips;
The workpiece is moved relative to the cutting blade in a direction opposite to the rotation direction of the cutting blade at a position facing the cutting blade and the workpiece, and the first cutting groove is formed by the cutting blade. By tracing, one of the burrs generated at the two corners on the rear side in the cutting direction of the second step of each chip is not cut into the second cutting groove. A third step of sandwiching and removing between the blade and each chip;
The workpiece is moved relative to the cutting blade in a direction opposite to the rotation direction of the cutting blade at a position facing the cutting blade and the workpiece, and the cutting blade is moved into the second cutting groove. The burr generated on the other of the two corner portions is removed by being sandwiched between the cutting blade and each of the chips so as not to escape into the first cutting groove. 4 steps;
A dicing method comprising:

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