JP7175628B2 - chuck table - Google Patents

Description

TECHNICAL FIELD The present invention relates to a chuck table used for dividing a plate-shaped object, which is formed integrally with a plurality of chips partitioned by dividing lines, into individual chips by cutting the dividing lines with a cutting blade.

A package substrate, in which a plurality of devices such as ICs and LSIs are positioned on a wiring substrate with the front surface thereof partitioned by dividing lines and whose back surface is sealed with mold resin, is divided into chips for each sealed device by a dicing machine. , each of the divided chips is used in electrical equipment such as mobile phones and personal computers (see, for example, Patent Document 1).

A dicing apparatus includes a chuck table that holds a plate-like object such as a package substrate, a cutting means that divides the plate-like object held by the chuck table into individual chips, and a carry-out means that carries out the individual chips from the chuck table. and can efficiently divide the plate into individual chips.

Also, the chuck table is composed of rubber having a surface for holding a plate-like object and a base for supporting the back surface of the rubber. The surface of the rubber is formed with a plurality of escape grooves for receiving the cuts of the cutting blade corresponding to the planned division lines, and suction holes for sucking and holding individual chips in the regions partitioned by the escape grooves. Individual chips can be held by suction even after the object has been divided into individual chips.

Japanese Patent No. 5947010

However, when all the chips are unloaded from the chuck table at once, even if the suction force of the chuck table is released, some chips remain on the chuck table due to the adhesion of the rubber, and the remaining chips must be unloaded again. However, there is a problem of poor productivity. In particular, the above problem is likely to occur when the size of the chip is as small as 1.0 mm square or less.

SUMMARY OF THE INVENTION The object of the present invention, which has been devised in view of the above facts, is to be able to reliably suck and hold a plate-shaped object and divided chips when a suction force is applied, and to divide the chips when the suction force is released. To provide a chuck table capable of surely carrying out a chip that has been picked up.

In order to solve the above problems, the present invention provides the following chuck table. That is, a chuck table used for dividing a plate-shaped object, which is formed integrally by dividing a plurality of chips by a dividing line, into individual chips by cutting the dividing line with a cutting blade. and a base for supporting the back surface of the rubber, and the surface of the rubber has a plurality of escape grooves for receiving the cuts of the cutting blade corresponding to the line to be divided, and the Suction holes for sucking and holding individual chips are formed in areas partitioned by the escape grooves, communication holes communicating with the suction holes are formed in the base, and the escape grooves are formed on the surface of the rubber. In the chuck table, projections are formed on the periphery of the area partitioned by and the projections are formed at the four corners of the area partitioned by the clearance groove .

The size of the protrusions is preferably 40 to 50 μm square and 3 to 7 μm in height.

The chuck table provided by the present invention comprises a rubber having a surface for holding a plate-like object and a base for supporting the back surface of the rubber. A plurality of escape grooves for receiving the cuts of the blade and suction holes for sucking and holding the individual chips are formed in the areas partitioned by the escape grooves, and the base is formed with communication holes communicating with the suction holes. On the surface of the rubber, projections are formed on the periphery of the area defined by the clearance groove, and the projections are formed at the four corners of the area defined by the clearance groove, so that a suction force is applied. When the suction force is released, the protrusions of the rubber are crushed and the plate-like object and the split tip adhere to the surface of the rubber. , the rubber protrusion returns to its original shape, the contact area between the split tip and the rubber surface is reduced, the adhesion is reduced, and the split tip can be reliably carried out from the chuck table. The problem of some chips remaining on the chuck table can be solved.

3 is a perspective view of a package substrate; FIG. FIG. 4 is a perspective view of a chuck table before processing; (a) A perspective view showing a state in which projections are formed in regions partitioned by escape grooves, (b) A cross-sectional view showing a state in which projections are formed in regions partitioned by escape grooves. FIG. 4 is a partially enlarged perspective view of a chuck table in which protrusions are formed at four corners of areas partitioned by escape grooves; FIG. 4 is a partially enlarged perspective view of a chuck table in which projections are formed at a total of four locations, namely an intermediate portion in the X-axis direction and an intermediate portion in the Y-axis direction in a region partitioned by relief grooves;

An embodiment of a chuck table constructed according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a rectangular package substrate 2 as an example of a plate-like object to be divided into individual chips by a dicing apparatus equipped with a chuck table constructed according to the present invention. The package substrate 2 is integrally formed with a plurality of chips 4 partitioned by grid-like dividing lines 6 . Devices such as ICs and LSIs are arranged in each chip 4, and each device is sealed with mold resin. Each chip 4, which can be formed to be 1 mm square or less, is formed to be approximately 0.5 mm square in the illustrated embodiment. Then, the package substrate 2 is cut along dividing lines 6 by a cutting blade (not shown) of a dicing machine, and divided into individual chips 4 for each device.

The structure and manufacturing process of the chuck table constructed according to the present invention will be described with reference to FIGS. When manufacturing the chuck table of the present invention, first, a pre-machining chuck table 8 shown in FIG. 2 is prepared. The pre-machining chuck table 8 is composed of a rubber 10 having a surface 10a for holding a plate-like object and a base 12 supporting the back surface of the rubber 10. As shown in FIG. The rubber 10 in the illustrated embodiment is formed in a rectangular shape having dimensions corresponding to the dimensions of the package substrate 2 (dimensions slightly larger than the dimensions of the package substrate 2).

As shown in FIG. 2, on the surface 10a of the rubber 10, there are a plurality of grid-shaped escape grooves 14 for receiving the cuts of the cutting blade of the dicing machine corresponding to the grid-shaped dividing lines 6 of the package substrate 2, and a plurality of escape grooves. A suction hole 16 for holding each chip 4 by suction is formed in the area partitioned by 14 . The size of each rectangular area partitioned by the escape groove 14 corresponds to the size of each chip 4 on the package substrate 2, and is formed to be approximately 0.5 mm square in the illustrated embodiment. The base 12 is also formed with a plurality of communication holes (not shown) communicating with the suction holes 16 of the rubber 10 . The drawings are only schematic diagrams, and the dimensions of each part are exaggerated.

After the pre-machining chuck table 8 is prepared, protrusions are formed in the areas defined by the relief grooves 14 on the surface 10a of the rubber 10. As shown in FIG. Formation of the protrusions can be carried out using, for example, a grinding apparatus partly shown in FIG. The grinding device includes a holding table (not shown) that holds the pre-machining chuck table 8 and a grinding wheel 18 that grinds the pre-machining chuck table 8 held by the holding table.

The holding table is advanced and retracted in the X-axis direction indicated by arrow X in FIG. rotated. In addition, an annular grinding wheel 20 that can be formed by bonding diamond abrasive grains with a metal bond is arranged on the outer periphery of the grinding wheel 18 . The grinding wheel 18 is rotated by a grinding wheel motor (not shown) about the Y-axis direction (the direction indicated by the arrow Y in FIG. 3) perpendicular to the X-axis direction, and rotates in the Y-axis direction. It is advanced and retracted by Y-axis feeding means and vertically moved by lifting means (not shown). The thickness of the grinding wheel 20 in the axial direction is smaller than the area defined by the relief groove 14, and in the illustrated embodiment, it is formed to be approximately 400 to 420 μm. A plane defined by the X-axis direction and the Y-axis direction is substantially horizontal.

Continuing the description with reference to FIG. 3, when forming protrusions using the grinding device in the region defined by the escape groove 14, first, the surface 10a of the rubber 10 faces upward and the grinding device is held. The table holds the chuck table 8 before processing. The longitudinal direction of the rubber 10 is then aligned with the X-axis direction and the grinding wheel 18 is positioned above the area defined by the relief groove 14 . Next, the grinding wheel 18 rotated in the direction indicated by arrow A in FIG. 3(a) is lowered, and as shown in FIG. Grinding to grind the surface 10a of the rubber 10 along the X-axis direction while leaving the both side ends of the area defined by the clearance groove 14 by moving the holding table relative to 18 in the X-axis direction. process.

Next, the grinding wheel 18 is indexed and fed relative to the holding table in the Y-axis direction by the distance in the Y-axis direction of the area defined by the clearance groove 14 . Then, the grinding process and the indexing feed are alternately repeated to grind the entire region defined by the escape groove 14, and the holding table is rotated by 90 degrees to alternately repeat the grinding process and the indexing feed. . In this way, all the areas defined by the escape grooves 14 are ground in a grid pattern to form projections 22 at the four corners of all the areas defined by the escape grooves 14, as shown in FIG. The size of the projection 22 in the illustrated embodiment is several tens of μm square (for example, about 40 to 50 μm square) and several μm in height (for example, about 3 to 7 μm).

When the surface 10a of the rubber 10 is ground by the grinding wheel 20 to form the projections 22, it is preferable to perform the grinding in a dry manner without supplying grinding water to the grinding area. This is because if the grinding water is supplied to the grinding area, the grinding water may enter between the surface 10a of the rubber 10 and the grinding wheel 20, and the surface 10a of the rubber 10 may not be ground to the required depth.

The chuck table 24, in which the projections 22 are formed at the four corners of the regions partitioned by the escape grooves 14 as described above, is mounted on a dicing machine (not shown), and each communicating hole of the base 12 is diced. It is connected to the suction means of the device. When the package substrate 2 is to be divided into individual chips 4 for each device by cutting the planned division lines 6 of the package substrate 2 with the cutting blade of this dicing machine, first, the planned division lines 6 of the package substrate 2 are cut. The package substrate 2 is placed on the surface 10 a of the rubber 10 of the chuck table 24 after aligning it with the escape groove 14 of the rubber 10 . Next, the suction means connected to each communication hole is operated to apply a suction force to the surface 10 a of the rubber 10 . Then, the protrusions 22 of the rubber 10 are crushed and the package substrate 2 is brought into close contact with the surface 10a of the rubber 10, so that the chuck table 24 can reliably hold the package substrate 2 by suction. Further, even after the package substrate 2 is divided into the individual chips 4 by cutting the dividing line 6 with the cutting blade, the chuck table 24 is not divided while the suction force is applied to the surface 10a of the rubber 10. It is possible to reliably suck and hold the tip 4 that has been applied. When the suction force is released, the protrusion 22 of the rubber 10 returns to its original shape, and the contact area between the divided tip 4 and the surface 10a of the rubber 10 decreases, reducing the adhesion force. 4 can be reliably carried out from the chuck table 24, and the problem that some chips 4 remain on the chuck table 24 can be solved.

In the illustrated embodiment, the surface 10a of the rubber 10 is ground by the grinding wheel 20 to form the protrusions 22. However, the protrusions 22 may be formed on the surface 10a of the rubber 10 by pressing. Further, in the illustrated embodiment, an example in which the projections 22 are formed at the four corners of the area partitioned by the escape groove 14 has been described, but as shown in FIG. The protrusions 22 may be formed at a total of four locations, the intermediate portion in the direction and the intermediate portion in the Y-axis direction.

2: Package substrate (plate-shaped object)
4: Tip 6: Scheduled division line 8: Chuck table before processing 10: Rubber 10a: Surface of rubber 12: Base 14: Escape groove 16: Suction hole 22: Protrusion 24: Chuck table

Claims (2)

A chuck table for use in dividing a plate-like object, which is formed integrally with a plurality of chips partitioned by a line to be divided, into individual chips by cutting the line to be divided with a cutting blade,
Consists of a rubber having a surface that holds a plate-shaped object and a base that supports the back surface of the rubber,
The surface of the rubber is formed with a plurality of escape grooves for receiving the cuts of the cutting blade corresponding to the planned division lines, and suction holes for sucking and holding individual chips in the areas defined by the escape grooves,
A communication hole communicating with the suction hole is formed in the base,
A projection is formed on the surface of the rubber on the periphery of the area defined by the relief groove ,
A chuck table in which the protrusions are formed at four corners of the area defined by the relief grooves . 2. The chuck table according to claim 1, wherein the projection has a size of 40 to 50 μm square and a height of 3 to 7 μm.

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