JP6934395B2 - Dividing device and dividing method - Google Patents

Description

The present invention relates to a dividing device and a dividing method in which a substrate is held by a holding means and divided into a plurality of chips.

In general, semiconductor packages used in mobile communication devices such as mobile phones are required to suppress leakage of unnecessary electromagnetic waves to the outside in order to prevent adverse effects on communication characteristics. Therefore, a structure is known in which a shield layer is formed along the outer surface of a resin layer that seals a semiconductor chip in a semiconductor package. On the other hand, in the semiconductor package, the surfaces of the wiring boards are partitioned in a grid pattern by intersecting scheduled division lines, and a plurality of semiconductor chips are mounted in the plurality of partitioned regions. Further, on the back surface of the wiring board opposite to the surface on which the resin layer is formed, bumps having a plurality of convex shapes are formed as electrodes (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-039104

In the semiconductor package described in Patent Document 1, since the back surface of the wiring board is formed uneven by the bumps, it becomes difficult to hold the semiconductor package on the bump side by a holding means such as a table. Therefore, there is a problem that it is difficult to cut the resin layer of the semiconductor package by a cutting blade or the like that rotates at high speed, or to cut and divide the semiconductor package at a position along the planned division line.

The present invention has been made in view of this point, and an object of the present invention is to provide a dividing device and a dividing method capable of satisfactorily holding and dividing the convex portion side of a substrate having a convex portion such as a bump. Let it be one of.

In the dividing device of one aspect of the present invention, a substrate having a plurality of convex portions formed on the back surface of the substrate and a plurality of scheduled division lines formed on the front surface side of the substrate is held by the holding means and along the scheduled division line by a processing tool. It is a dividing device that divides into individual chips, and the holding means includes a relief groove of a machining tool formed at a position corresponding to a planned division line, and a plurality of holding surfaces corresponding to the chips partitioned by the relief groove. A holding portion having a For the substrate that has been frozen and adsorbed by supplying the liquid at least until it covers the convex portion and reaches the surface of the substrate, the machining tool is cut to the escape groove in an atmosphere at a temperature lower than the melting point of the frozen liquid, and the substrate is divided into a planned division line. It is characterized by being divided along.

According to this configuration, when machining with a processing tool, the substrate is frozen and adsorbed by the liquid supplied to the holding means, so that even if the back surface of the substrate is uneven due to the convex portion, the substrate is held on the back surface side. You can get enough power. As a result, the yield when dividing the substrate into chips along the planned division line of the substrate can be improved, and the substrate can be processed with high accuracy and good quality.

In the dividing device of the present invention, the substrate is a semiconductor package in which semiconductor chips are arranged in a region partitioned by intersecting scheduled division lines on the surface of the wiring board, sealed with a sealant, and bumps are formed on the back surface of the wiring board. It is a substrate, and the bumps of the semiconductor package substrate are brought into contact with the holding surface and placed on the holding portion, and liquid is supplied at least until the bumps are covered and reaches the wiring board, and the wiring board is frozen and adsorbed. It is preferable to cut the processing tool to the relief groove in an atmosphere having a temperature lower than the melting point of the liquid and divide the semiconductor package substrate along the planned division line.

Further, in the division method of one aspect of the present invention, a substrate having a plurality of convex portions formed on the back surface of the substrate and a plurality of scheduled division lines formed on the front surface side of the substrate is held by the holding means, and the scheduled division line is performed by a processing tool. It is a division method of dividing into individual chips along the line, and the holding means is a relief groove of a machining tool formed at a position corresponding to a planned division line, and a plurality of holdings corresponding to the chips partitioned by the relief groove. It is provided with a holding portion having a surface and a water storage wall that surrounds the holding portion and stands upright to store liquid in the holding portion, and the convex portion of the substrate is brought into contact with the holding surface and placed on the holding portion. Then, the atmosphere is lower than the melting point of the frozen liquid with respect to the cooling adsorption step in which the liquid is supplied at least until it covers the convex portion and reaches the surface of the substrate and is frozen and adsorbed, and the substrate which is frozen and adsorbed in the cooling adsorption step. It is characterized by performing a division step in which the processing tool is cut to the relief groove and the substrate is divided along the planned division line.

According to the present invention, since the liquid is supplied so as to cover the convex portion side of the bump or the like and then frozen and adsorbed, the convex portion side of the substrate can be well held and divided.

It is a perspective view of the division apparatus which concerns on this embodiment. It is the schematic sectional drawing of the semiconductor package substrate. It is a schematic perspective view of the semiconductor package substrate and the holding means. It is the schematic perspective view of the state which the holding means holds the semiconductor package substrate. It is a figure which shows an example of a cooling adsorption step. It is a figure which shows an example of the division step. It is a figure which shows an example of the division step.

Hereinafter, the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the dividing device according to the present embodiment. The dividing device according to the present embodiment is not limited to the configuration shown in FIG. The present invention can be applied to any dividing device as long as it can divide the substrate frozen and adsorbed by the holding means. Further, in the following description, a semiconductor package substrate will be described as an example of the substrate, but the type of substrate is not limited to the semiconductor package substrate.

As shown in FIG. 1, the dividing device 1 is configured to cut the semiconductor package substrate W by relatively moving the semiconductor package substrate W as the substrate held by the holding means 12 and the processing tool 14. ing. Here, the semiconductor package substrate W is a substrate for forming a plurality of semiconductor package (chips) WA, and in the present embodiment, it is formed in a rectangular planar shape. The semiconductor package substrate W is partitioned by a plurality of scheduled division lines W2 that intersect in a grid pattern on the surface (upper surface) Wa of the wiring substrate (interposer substrate) W1.

FIG. 2 is a schematic cross-sectional view of a semiconductor package substrate. As shown in FIG. 2, semiconductor chips W3 are arranged in each region partitioned by the semiconductor package substrate W, and each semiconductor chip W3 is sealed with a resin layer (sealing agent) W4. A plurality of bumps (convex-shaped portions) W5 that function as electrodes are formed on the back surface (lower surface) Wb of the wiring board W1. Although not particularly limited, the semiconductor package WA formed by dividing the semiconductor package substrate W along the planned division line W2 is a so-called EMI (Electro-Magnetic Interference) for all packages that need to be blocked. It can be exemplified as a semiconductor device. In this case, a shield layer is provided on the outer surface of the semiconductor package WA so as to suppress leakage of electromagnetic noise to the surroundings.

FIG. 3 is a schematic perspective view of the semiconductor package substrate and the holding means, and FIG. 4 is a schematic perspective view of the state in which the semiconductor package substrate is held by the holding means. As shown in FIGS. 3 and 4, the holding means 12 recesses the upper surface side of the rectangular table member to store the liquid L (shown by halftone dots in FIG. 4, not shown in FIG. 3). It is configured to form space 20. The holding means 12 includes a holding portion 21 formed by the bottom surface of a region recessed to form a water storage space 20, and a water storage wall 22 erected at a position surrounding the holding portion 21 from all sides. Liquid L is stored above 21. The inner peripheral surface of the water storage wall 22 is inclined in a direction away from the holding portion 21 as it goes upward. Further, at the intersection position of the holding portion 21 and the water storage wall 22, it is formed so as to form a shape along an arc in the cross-sectional view of FIG. 5 (see FIG. 5).

Relief grooves 24 are formed in the holding portion 21 in a grid pattern. The relief groove 24 is formed at a position corresponding to the planned division line W2 of the semiconductor package substrate W, in other words, at a position overlapping the planned division line W2 of the semiconductor package substrate W held by the holding portion 21 in terms of top view. In the holding portion 21, a plurality of rectangular surfaces partitioned by the relief groove 24 are designated as the holding surface 21a. Each holding surface 21a corresponds to the position and size of the semiconductor package WA formed from the semiconductor package substrate W, and the outer peripheral positions of the respective semiconductor package WA and the holding surface 21a are substantially aligned in the vertical direction. ..

Returning to FIG. 1, a cutting feed means 13 for cutting and feeding the holding means 12 in the X direction is provided on the base 11 of the cutting device 1. The cutting feed means 13 has a pair of guide rails 31 arranged on the base 11 parallel to the X direction and a motor-driven X-axis table 32 slidably installed on the pair of guide rails 31. There is. A nut portion (not shown) is formed on the back side of the X-axis table 32, and a ball screw 33 is screwed into the nut portion. Then, the drive motor 34 connected to one end of the ball screw 33 is rotationally driven, so that the holding means 12 is cut and fed along the pair of guide rails 31 in the X direction, which is the cutting direction of the cutting blade 71. ..

A holding means 12 for holding the semiconductor package substrate W is rotatably provided on the upper part of the X-axis table 32 around the Z-axis. Further, on the upper surface of the base 11, a gate-shaped standing wall portion 81 is provided so as to straddle the moving path of the holding means 12.

The vertical wall portion 81 is provided with an index feeding means 15 for index feeding the machining tool 14 in the Y direction and a cutting feeding means 16 for cutting and feeding the machining tool 14 in the Z direction. The index feeding means 15 has a pair of guide rails 51 arranged in front of the vertical wall portion 81 parallel to the Y direction and a pair of Y-axis tables 52 slidably installed on the pair of guide rails 51. There is. The cut feed means 16 has a pair of guide rails 61 arranged on the Y-axis table 52 parallel to the Z direction and a Z-axis table 62 slidably installed on the pair of guide rails 61. A processing tool 14 for cutting a wafer W is provided below each of the pair of Z-axis tables 62.

Nut portions (not shown) are formed on the back side of the Y-axis table 52 and the Z-axis table 62, respectively, and ball screws 53 and 63 are screwed into these nut portions. Drive motors 54 and 64 are connected to one end of the ball screw 53 for the Y-axis table 52 and the ball screw 63 for the Z-axis table 62, respectively. The ball screws 53 and 63 are rotationally driven by these drive motors 54 and 64, so that the machining tool 14 is index-fed along the guide rail 51 in the Y direction, and the machining tool 14 is Z along the guide rail 61. It is cut and fed in the direction.

The machining tool 14 is configured by mounting a cutting blade 71 on the tip of a spindle 72 protruding from the housing 70. A spindle 72, which is a rotation axis of the cutting blade 71, is rotatably supported in the housing 70, and a motor (not shown) for rotating the spindle 72 is installed in the housing 70. Further, a blade cover 73 surrounding the cutting blade 71 is provided on the tip end side of the housing 70 so that the area where the cutting blade 71 cuts into the semiconductor package substrate W is exposed.

Here, of the two machining tools 14, the cutting blade 71 of one machining tool 14 is a cutting blade 71a having a V-shaped tip (hereinafter referred to as a V blade; see FIG. 6), and the other is cut. The blade 71 is a normal cutting blade 71b having a rectangular tip (hereinafter, referred to as a straight blade; see FIG. 7). The tips of the V-blade 71a and the straight blade 71b are formed into the above-mentioned shape by solidifying diamond abrasive grains or the like with a binder.

Subsequently, the method of dividing the semiconductor package substrate W in the present embodiment will be described with reference to FIGS. 5 to 7. FIG. 5 is a diagram showing an example of a cooling adsorption step. 6 and 7 are diagrams showing an example of the division step. In the cross-sectional views of FIGS. 5 to 7, the semiconductor chip W3 is not shown.

As shown in FIG. 5, the cooling adsorption step is first carried out. In the cooling adsorption step, the semiconductor package substrate W is arranged in the water storage space 20 of the holding means 12 with the bumps W5 facing downward. Then, the semiconductor package substrate W is placed on the holding surface 21a so that the lower end of the bump W5 comes into contact with the holding surface 21a of the holding portion 21. After such placement, the liquid L is supplied into the water storage space 20. The supply amount of the liquid L is set until the liquid L covers at least the bump W5 as a whole and the liquid level of the liquid L reaches the surface Wa of the wiring board W1.

With the liquid L supplied into the water storage space 20, the holding means 12 is exposed to an atmosphere below the freezing point of the liquid L, and the liquid L is solidified to form a frozen body C. As a result, the bump W5 is put into the frozen body C, the semiconductor package substrate W is fixed by the frozen body C, and the frozen body C is fixed to the holding portion 21 and the water storage wall 22 by freezing. That is, the semiconductor package substrate W is frozen and adsorbed on the holding means 12 and fixed.

From the time when the liquid L is supplied until it is solidified, the semiconductor package substrate W is subjected to a pressing force from above by the pressing member 90. For example, this pressing force is applied via a drive mechanism such as an air cylinder (not shown), or the weight of the pressing member 90 is applied. The pressing member 90 is a rigid body having a flat lower surface, and is maintained in a state of being in surface contact with the resin layer W4 on the upper surface side of the semiconductor package substrate W. In other words, while the liquid L is frozen, the state in which the semiconductor package substrate W is sandwiched between the holding portion 21 and the pressing member 90 from the thickness direction is maintained. As a result, it is possible to prevent the semiconductor package substrate W from being warped during freezing adsorption even if there is a difference in temperature, structure, etc. between the upper and lower surfaces of the semiconductor package substrate W.

As a method of exposing the liquid L to an atmosphere below the freezing point, for example, a method of supplying the liquid L to the holding means 12 on which the semiconductor package substrate W is placed and then putting the holding means 12 into the freezer can be considered. In this case, the holding means 12 may be removed from the X-axis table 32 and put into the freezer, or the entire dividing device 1 may be installed in the freezer or in a room set to a temperature equal to or lower than the freezing point.

After the cooling adsorption step is carried out, a division step in which the semiconductor package substrate W is divided by a so-called step cut is carried out. As shown in FIG. 6, in the dividing step, first, the V blade 71a is aligned with the planned division line W2 on the outside of the semiconductor package substrate W frozen and adsorbed by the holding means 12 as shown by the alternate long and short dash line. The wiring board W1 is lowered to a depth halfway in the thickness direction.

After that, the semiconductor package substrate W is cut and fed to the V blade 71a rotating at high speed, and the semiconductor package substrate W is half-cut along the scheduled division line W2. By such a half cut, a V groove W6 is formed on the upper surface side of the resin layer W4, and by repeating the half cut, a plurality of V grooves W6 are formed on the upper surface of the semiconductor package substrate W along the planned division line W2.

After the V-groove W6 is formed in this way, as shown in FIG. 7, the straight blade 71b is shown by the alternate long and short dash line with respect to the line W2 scheduled to be split outside the semiconductor package substrate W frozen and adsorbed by the holding means 12. Is aligned, and the lower end thereof is lowered halfway in the depth direction of the relief groove 24. After that, the semiconductor package substrate W is cut and fed to the straight blade 71b rotating at high speed, and the semiconductor package substrate W is fully cut along the V groove W6 (scheduled division line W2).

At this time, the lower end of the straight blade 71b cuts into the relief groove 24, in other words, the frozen body C in the relief groove 24 is cut while the lower end of the straight blade 71b is kept in non-contact with the inner peripheral surface of the relief groove 24. The semiconductor package substrate W is cut. The semiconductor package substrate W is completely cut along the scheduled division line W2 by such a full cut, and the semiconductor package substrate W is divided into individual semiconductor package WAs by repeating the full cut.

The above division step is carried out in an atmosphere having a temperature lower than the melting point of the frozen liquid L, that is, the frozen body C. For example, implementation at a low temperature can be realized by using an air conditioner or installing the entire dividing device 1 in a freezer. In addition, the machining in the division step is performed while supplying cutting water to the cutting part, but since the atmosphere is maintained below the freezing point, it is necessary to mix antifreeze in the cutting water to prevent the cutting water from freezing. ..

As described above, according to the present embodiment, since the liquid L supplied by the holding means 12 is frozen and the semiconductor package substrate W is frozen and adsorbed, the back surface Wb of the wiring board W1 is uneven due to the plurality of bumps W5. Even so, the force for holding the semiconductor package substrate W on the holding surface 21a can be sufficiently exerted. As a result, for example, when the bump W5 is formed on the entire back surface of the semiconductor package WA, the portion that can be sucked by the conventional suction holding by negative pressure is narrow and it is difficult to hold the bump W5. Even if the forming region of the is widened, a sufficient holding force can be obtained on the entire back surface of the semiconductor package WA.

Further, as a conventional method of adsorbing a substrate having bumps, a tape is attached to the back surface of the substrate, the bumps are embedded in the adhesive layer of the tape to keep the tape smooth, and the substrate is passed through the tape. There is a method of sucking and holding. In this case, not only the work load of attaching and peeling the tape, but also the work load of cleaning the adhesive material of the adhesive layer adhering to the bump is forced. Can be eliminated.

Further, in the present embodiment, when the V-groove W6 is formed in the dividing step, the frozen body C is interposed between the holding portion 21 and the wiring board W1 so as to be filled, and further, the inside of the escape groove 24 is formed. Will be filled with the frozen body C. Therefore, even if a force that pushes down the V-blade 71a to form the V-groove W6 acts on the semiconductor package substrate W, a bearing force that opposes the force can be stably exerted through the frozen body C, and the semiconductor package can be packaged. It is possible to prevent the substrate W from being deformed or damaged such as cracking. As a result, the side surface of the semiconductor package WA can be easily formed as an inclined surface by the V-groove W6, and a shield layer can be easily formed on the inclined surface from above by a screen printing method, a spray coating method, an inkjet method, a sputtering method, or the like. can do. As a result, when it is necessary to give the semiconductor package WA a shielding function, the sheet metal shield can be eliminated, and it is possible to avoid an increase in the thickness and size of the entire device due to the thickness of the sheet metal shield itself. can.

In the present invention, various substrates such as other package substrates, semiconductor device wafers, optical device wafers, semiconductor substrates, inorganic material substrates, and piezoelectric substrates may be used as the substrates to be processed. As the semiconductor device wafer, a silicon wafer or a compound semiconductor wafer after device formation may be used. As the optical device wafer, a sapphire wafer or a silicon carbide wafer after device formation may be used. Further, as a package substrate, a CSP (Chip Size Package) substrate, a rectangular package substrate such as QFN (Quad Flat Non-leaded package), a semiconductor substrate such as silicon or gallium arsenide, and an inorganic material substrate such as sapphire or ceramics. Glass or the like may be used.

Further, in the present embodiment, the case where the cutting blade 71 for cutting the substrate such as the semiconductor package substrate W is used as the processing means 14 has been described as an example, but the present invention is not limited to this configuration. The processing means 14 in the present invention may be configured by using a laser processing head or the like as long as the substrate can be divided along the planned division line W2.

Further, the convex portion formed on the substrate is not limited to the bump, and can be exemplified by substituting a protrusion or the like that does not function as an electrode.

Moreover, although the present embodiment and the modified example have been described, as another embodiment of the present invention, the above-described embodiment and the modified example may be combined in whole or in part.

Further, the embodiment of the present invention is not limited to the above-described embodiment, and may be variously modified, replaced, or modified without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by the advancement of technology or another technology derived from it, it may be carried out by using that method. Therefore, the scope of claims covers all embodiments that may be included within the scope of the technical idea of the present invention.

Further, in the present embodiment, the configuration in which the holding means of the present invention is applied to the dividing device has been described, but it is also possible to apply the holding means to other devices for holding the substrate and performing various processing.

As described above, the present invention has the effect of being able to satisfactorily hold and divide the convex portion side of the substrate, and is particularly useful for an apparatus for processing a semiconductor package substrate having bumps formed on the back surface of the wiring board. Is.

1 Dividing device 12 Holding means 14 Machining tool 21 Holding part 21a Holding surface 22 Water storage wall 24 Relief groove L Liquid W Semiconductor package substrate (board)
WA semiconductor package (chip)
Wa Front surface Wb Back surface W1 Wiring board W2 Scheduled division line W3 Semiconductor chip W4 Resin layer (sealing agent)
W5 bump (convex shape part)

Claims (3)

A dividing device in which a substrate having a plurality of convex portions formed on the back surface of the substrate and a plurality of scheduled division lines formed on the front surface side of the substrate is held by a holding means and divided into individual chips along the scheduled division lines by a processing tool. And
The holding means includes a holding portion having a relief groove of the machining tool formed at a position corresponding to the planned division line, and a plurality of holding surfaces corresponding to the inserts partitioned by the relief groove, and the holding portion. It is provided with a water storage wall that surrounds the part and stands upright to store liquid in the holding part.
The convex portion of the substrate is brought into contact with the holding surface and placed on the holding portion, and liquid is supplied at least until the convex portion is covered and reaches the surface of the substrate, and the substrate is frozen and adsorbed. On the other hand, a dividing device that cuts the processing tool to the relief groove in an atmosphere having a temperature lower than the melting point of the frozen liquid and divides the substrate along the planned division line. The substrate is a semiconductor package substrate in which semiconductor chips are arranged in a region partitioned by intersecting scheduled division lines on the surface of the wiring board, sealed with a sealant, and bumps are formed on the back surface of the wiring board.
The bump of the semiconductor package substrate is brought into contact with the holding surface and placed on the holding portion, and a liquid is supplied at least until the bump is covered and reaches the wiring board, and the wiring board is frozen and adsorbed. The dividing device according to claim 1, wherein the processing tool is cut to the relief groove in an atmosphere having a temperature lower than the melting point of the frozen liquid, and the semiconductor package substrate is divided along the planned division line. A dividing method in which a substrate having a plurality of convex portions formed on the back surface of the substrate and a plurality of scheduled division lines formed on the front surface side of the substrate is held by a holding means and divided into individual chips along the scheduled division lines by a processing tool. And
The holding means includes a holding portion having a relief groove of the machining tool formed at a position corresponding to the planned division line, and a plurality of holding surfaces corresponding to the inserts partitioned by the relief groove, and the holding portion. It is provided with a water storage wall that surrounds the part and stands upright to store liquid in the holding part.
A cooling adsorption step in which the convex portion of the substrate is brought into contact with the holding surface and placed on the holding portion, and liquid is supplied at least until it reaches the surface of the substrate and is frozen and adsorbed. ,
A division step in which a processing tool is cut into the relief groove in an atmosphere having a temperature lower than the melting point of the frozen liquid with respect to the substrate frozen and adsorbed in the cooling adsorption step, and the substrate is divided along the planned division line. A division method characterized by carrying out and.

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