JP7009306B2 - Cutting equipment - Google Patents

Description

The present invention relates to a cutting device.

A cutting device (so-called dicer) for cutting various plate-shaped workpieces such as semiconductor wafers, resin package substrates, ceramics and glass substrates with a cutting blade is known. In this type of cutting device, it is common to cut a work piece in a frame unit in which the work piece is fixed to an annular frame with a dicing tape so that the work piece after cutting does not fall apart. The cutting device includes a porous chuck table installed on a table base, and the porous chuck table uniformly sucks and holds the entire workpiece.

On the other hand, the above-mentioned dicing tape is a factor of cost increase because it is disposable, and when cutting a resin package substrate having a low unit price of a chip as a workpiece, a jig chuck table that does not use the dicing tape is used as a table. A cutting device installed on the base may be used. Since the jig chuck table sucks and holds each tip, a strong vacuum force is required to prevent the tip from flying, and a strong suction source called a suction pump is used instead of the conventional ejector. Further, although the two chuck tables, the porous chuck table and the jig chuck table, are usually used in a dedicated machine, there is a demand for processing by either chuck table. Therefore, conventionally, a cutting device in which the porous chuck table and the jig chuck table can be exchanged according to the type of the workpiece has been proposed (see, for example, Patent Document 1).

Japanese Patent No. 4851282

By the way, in the above-mentioned cutting apparatus, a work called setup is performed in which the cutting edge of the cutting blade is brought into contact with the upper surface of the chuck table to set the origin position of the cutting blade. When performing this setup, a negative pressure is applied to the chuck table using a suction source, and it is determined whether or not the workpiece is on the chuck table based on the strength of the negative pressure. That is, if the workpiece is not placed on the chuck table, the negative pressure in the pipe connecting the suction source and the chuck table is usually low (weak) due to leakage even if negative pressure is applied, and the negative pressure is low. If does not reach a predetermined reference value and is weak, it can be determined that the workpiece is not placed.

However, in the cutting device in which the two chuck tables are interchangeable as described above, the porous chuck table has a larger distribution resistance at the time of suction than the jig chuck table. Therefore, when a negative pressure is applied to the porous chuck table using a powerful suction source such as a suction pump, the negative pressure in the pipe becomes stronger than the standard value, and the workpiece becomes the chuck table. There is a problem that it cannot be accurately determined whether or not it is listed in.

The present invention has been made in view of the above, and even in a configuration in which the porous chuck table and the jig chuck table can be exchanged, it is accurately determined whether or not the workpiece is placed on the porous chuck table. It is an object of the present invention to provide a cutting device capable of performing.

In order to solve the above-mentioned problems and achieve the object, the present invention has a suction unit in which a chuck table for sucking and holding a work piece is replaceably fixed to a table base, and a work piece held on the chuck table. The chuck table is provided with a cutting unit for cutting an object and a determination mechanism for determining whether or not the workpiece is placed on the chuck table, and the chuck table is a porous chuck that sucks and holds the workpiece on a porous surface. A cutting device selected from a table and a jig chuck table that sucks and holds a work piece by a suction opening formed on a holding surface. The suction unit has one end connected to a suction source and the other end connected to a suction source. 1 A suction path connected to a branch point via an on-off valve, and a first branch path connected to the branch point at one end and connected to the table base at the other end to exert a negative pressure on the holding surface of the chuck table. A second branch path is provided, one end of which is connected to the branch point and the other end of which is connected to the table base to apply a negative pressure to the holding surface of the chuck table, and the determination mechanism is the first. A second open / close valve provided in the branch path, a pressure gauge provided between the second open / close valve of the first branch path and the table base, and a pressure gauge for measuring the pressure of the first branch path, and the first open / close valve. When the negative pressure measured by the pressure gauge does not reach the reference value with the valve open, the determination unit for determining that the workpiece is not placed on the chuck table and the porous chuck table are the same. It is provided with an on-off valve control unit that closes the second on-off valve when the determination unit makes a determination in a state of being fixed to the table base.

In this configuration, the suction source may be a suction pump.

According to the cutting apparatus according to the present invention, by measuring the pressure of the first branch path with the second open / close valve closed, the negative pressure measured by the pressure gauge becomes excessively strong beyond the reference value. Therefore, it is possible to accurately determine whether or not the workpiece is placed on the porous chuck table.

FIG. 1 is a perspective view showing a cutting device according to the present embodiment. FIG. 2 is a schematic configuration diagram showing an internal configuration of a suction unit and a determination mechanism when a jig chuck table is used. FIG. 3 is a schematic configuration diagram showing the internal configuration of the suction unit and the determination mechanism when the porous chuck table is used.

An embodiment (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. In addition, various omissions, substitutions or changes of the configuration can be made without departing from the gist of the present invention.

FIG. 1 is a perspective view showing a cutting device according to the present embodiment. As shown in FIG. 1, the cutting device 2 includes a base 4 on which each component is mounted. An X-axis moving mechanism (machining feed unit) 6 is provided on the upper surface of the base 4. The X-axis moving mechanism 6 includes a pair of X-axis guide rails 8 that are substantially parallel to the X-axis direction (machining feed direction), and the X-axis moving table 10 is slidably attached to the X-axis guide rail 8. ing.

A nut portion (not shown) is provided on the lower surface side of the X-axis moving table 10, and an X-axis ball screw 12 parallel to the X-axis guide rail 8 is screwed into the nut portion. An X-axis pulse motor 14 is connected to one end of the X-axis ball screw 12. By rotating the X-axis ball screw 12 with the X-axis pulse motor 14, the X-axis moving table 10 moves in the X-axis direction along the X-axis guide rail 8.

On the upper surface side (front surface side) of the X-axis moving table 10, a suction unit 17 that sucks and holds the workpiece to be machined is provided via the θ table 16. Further, the cutting device 2 is connected to a suction pump (suction source) 19 that applies a negative pressure for sucking and holding the workpiece to the suction unit 17. The θ table 16 is provided with a rotation drive source (not shown) such as a motor, and the suction unit 17 arranged on the upper part of the θ table 16 is rotated around a rotation axis substantially parallel to the Z axis direction (cut feed direction). Let me. The suction pump 19 is, for example, a water-sealed vacuum pump having a stronger suction force than the ejector vacuum pump and the suction force does not decrease even if water is sucked. Further, the suction unit 17 is machined and fed by moving the X-axis moving table 10 in the X-axis direction by the X-axis moving mechanism 6 described above.

The suction unit 17 includes a table base 18 arranged on the upper part of the θ table 16 and a chuck table 20 fixedly arranged on the table base 18. The chuck table 20 is configured so that the porous chuck table 120 and the jig chuck table 220 can be exchanged and arranged on the table base 18 according to the type of the workpiece. Specifically, when the wafer 100 is processed as the workpiece, the porous chuck table 120 is arranged on the table base 18. When the package substrate 200 is processed as the workpiece, the jig chuck table 220 is arranged on the table base 18. When it is not necessary to distinguish between the porous chuck table 120 and the jig chuck table 220, it is simply referred to as the chuck table 20, and the porous chuck table 120 and the jig chuck table 220 will be described later.

As shown in FIG. 1, for example, the wafer 100 is a disk-shaped semiconductor wafer or optical device wafer whose base material is silicon, sapphire, gallium, or the like. In the present embodiment, the wafer 100 is held and processed by the porous chuck table 120 in the state of the frame unit 103 supported by the annular frame 102 via the dicing tape (adhesive tape) 101 attached to the back surface. .. Although details are not shown, a plurality of regions are partitioned on the surface of the wafer 100 by a plurality of scheduled division lines formed in a grid pattern, and devices such as ICs and LSIs are formed in the partitioned regions. ..

As shown in FIG. 1, for example, the package substrate 200 has a substrate body 201 formed in a rectangular flat plate shape made of a material such as metal or ceramics, and a resin layer 202 laminated on the surface side of the substrate body 201. Be prepared for it. Although details are not shown, a plurality of areas are partitioned on the substrate main body 201 by a plurality of scheduled division lines formed in a grid pattern, and devices such as ICs and LSIs are mounted on the partitioned areas. Further, the resin layer 202 is made of a thermoplastic resin and seals a device mounted on the surface of the substrate main body 201.

Further, as shown in FIG. 2, a water case 38 is provided in the vicinity of the X-axis moving table 10 to temporarily store the waste liquid of the cutting fluid (for example, pure water) used in the cutting process. Has been done. The waste liquid stored in the water case 38 is discharged to the outside of the cutting device 2 via a drain (not shown) or the like. A transfer mechanism (not shown) for transporting the wafer 100 or the package substrate 200 to the chuck table 20 is provided at a position close to the chuck table 20.

A gate-shaped support structure 40 straddling the X-axis moving mechanism 6 is arranged on the upper surface of the base 4. Two sets of cutting unit moving mechanisms (indexing feed unit and cutting feed unit) 42 are provided on the upper part of the front surface of the support structure 40. Each cutting unit moving mechanism 42 is provided in common with a pair of Y-axis guide rails 44 arranged on the front surface of the support structure 40 and substantially parallel to the Y-axis direction (indexing feed direction, left-right direction). A Y-axis moving plate 46 constituting each cutting unit moving mechanism 42 is slidably attached to the Y-axis guide rail 44.

A nut portion (not shown) is provided on the back surface side of each Y-axis moving plate 46, and a Y-axis ball screw 48 substantially parallel to the Y-axis guide rail 44 is screwed into this nut portion. There is. 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 plate 46 moves in the Y-axis direction along the Y-axis guide rail 44.

A pair of Z-axis guide rails 52 that are substantially parallel to the Z-axis direction are provided on the front surface (surface) of each Y-axis moving plate 46. A Z-axis moving plate 54 is slidably attached to the Z-axis guide rail 52.

A nut portion (not shown) is provided on the back surface side of each Z-axis moving plate 54, and a Z-axis ball screw 56 parallel to the Z-axis guide rail 52 is screwed into the nut portion. .. A Z-axis pulse motor 58 is connected to one end of each Z-axis ball screw 56. When the Z-axis ball screw 56 is rotated by the Z-axis pulse motor 58, the Z-axis moving plate 54 moves in the Z-axis direction along the Z-axis guide rail 52.

Each cutting unit moving mechanism 42 is provided with a Y-axis measuring unit (not shown) for measuring the position of the Y-axis moving plate 46 in the Y-axis direction. Further, each cutting unit moving mechanism 42 is provided with a Z-axis measuring unit (not shown) for measuring the position of the Z-axis moving plate 54 in the Z-axis direction.

A cutting unit 60 for cutting the wafer 100 or the package substrate 200 is fixed to the lower part of each Z-axis moving plate 54. Further, a camera (imaging unit) 62 for photographing the wafer 100 or the package substrate 200 is provided at a position adjacent to the cutting unit 60. If the Y-axis moving plate 46 is moved in the Y-axis direction by each cutting unit moving mechanism 42, the cutting unit 60 and the camera 62 are indexed and fed, and if the Z-axis moving plate 54 is moved in the Z-axis direction, cutting is performed. The unit 60 and the camera 62 are cut and fed.

The cutting unit 60 includes a cutting blade 61 mounted on a rotary spindle (not shown) that is rotationally driven, and a cutting fluid supply nozzle 63 that supplies cutting fluid (for example, water) to the cutting blade 61. By moving the cutting blade 61 in the Z-axis direction and the Y-axis direction while supplying the cutting fluid to the rotating cutting blade 61, the wafer 100 or the package substrate 200 is cut and individualized into each chip.

The cutting device 2 includes a control unit 72 that controls each of the above-mentioned components according to the processing conditions of the workpiece (wafer 100 or package substrate 200) and the like. The control unit 72 includes an on-off valve control unit 73, a determination unit 74, and an input / output interface device (not shown). The control unit 72 has a microprocessor such as a CPU (central processing unit), executes a computer program stored in a ROM, generates a control signal for controlling the cutting apparatus 2, and is generated. The control signal is output to each component of the cutting device 2 via the input / output interface device.

By the way, before cutting, the cutting device 2 brings the cutting edge of the cutting blade 61 lowered in the Z-axis direction into contact with the upper surface of the chuck table 20 (porous chuck table 120 or jig chuck table 220) to perform this cutting. A work called setup for setting the origin position of the blade 61 in the Z-axis direction is performed. When performing this setup, if the cutting edge of the cutting blade 61 is brought into contact with the workpiece (wafer 100 or package substrate 200) placed on the chuck table 20, the cutting edge is damaged or cut by mistake. Since the work piece may be damaged by the cutting blade 61, it is determined whether or not the work piece is on the chuck table 20. Therefore, the cutting device 2 includes a determination mechanism 150 for determining whether or not the workpiece is on the chuck table 20. Next, this determination mechanism 150 will be described. FIG. 2 is a schematic configuration diagram showing an internal configuration of a suction unit and a determination mechanism when a jig chuck table is used. FIG. 3 is a schematic configuration diagram showing the internal configuration of the suction unit and the determination mechanism when the porous chuck table is used.

The jig chuck table 220 is installed on the table base 18 as shown in FIG. The jig chuck table 220 includes a holding jig 221 and a jig base 222. The holding jig 221 is formed in a rectangular shape by metal, and a resin sheet 223 is arranged on the upper surface of the holding jig 221. The upper surface of the resin sheet 223 serves as a holding surface 223A for holding the package substrate 200. Further, the holding jig 221 and the resin sheet 223 have a plurality of relief grooves 224 at positions corresponding to the planned division lines of the package substrate 200, and each region partitioned by the intersecting relief grooves 224 has a holding surface 223A. A suction hole 225 penetrating the back surface is formed. The jig base 222 is formed in a rectangular shape by metal and is connected to the holding jig 221. A first recess 226 facing the suction hole 225 of the holding jig 221 is formed on the upper surface of the jig base 222. Further, on the lower surface of the jig base 222, a second recess 227 facing the suction port 229 provided on the table base 18 is formed. The first recess 226 and the second recess 227 are communicated with each other by a communication hole 228.

Further, the suction unit 17 includes a jig chuck table 220 and a table base 18, and also includes a path 80 for connecting the jig chuck table 220 and the suction pump 19. Specifically, in the above-mentioned path 80, one end 81A is connected to the suction pump 19, the other end 81B is connected to the main suction path (suction path) 81, and one end 83A is connected to the branch point 82. The other end 83B is provided in parallel with the first branch path 83 connected to the suction port 229 of the table base 18 and the first branch path 83, one end 84A is connected to the branch point 82, and the other end 84B is connected. A second branch path 84 connected to the suction port 229 of the table base 18 is provided. In the present embodiment, the second branch path 84 is configured to be provided in parallel with two lines, but the present invention is not limited to this, and the number may be one or three or more.

The main suction path 81 is provided with a first opening / closing valve 85 between the suction pump 19 and the branch point 82. Further, in the first branch path 83, a second opening / closing valve 86 is provided between the branch point 82 and the suction port 229, and a pressure for measuring the pressure is provided between the second opening / closing valve 86 and the suction port 229. A sensor (pressure gauge) 87 is provided. The first on-off valve 85 is a valve that is controlled by the on-off valve control unit 73 of the control unit 72 to fully open or fully close the main suction path 81. The second on-off valve 86 is a valve that is controlled by the on-off valve control unit 73 of the control unit 72 to fully open or fully close the first branch path 83. The pressure sensor 87 measures the negative pressure (pressure) in the path 80 (first branch path 83), and outputs the measurement result to the determination unit 74 of the control unit 72.

When the suction pump 19 operates, a negative pressure is applied to the jig chuck table 220 through the main suction path 81, the first branch path 83 and the second branch path 84. Since the jig chuck table 220 is formed with a second recess 227, a communication hole 228, a first recess 226, and a suction hole 225, this negative pressure is applied to the package substrate 200 placed on the holding surface 223A through these. It is actuated to suck and hold the package substrate 200.

The determination mechanism 150 includes a second on-off valve 86, a pressure sensor 87, a determination unit 74 of the control unit 72, and an on-off valve control unit 73. The determination unit 74 determines whether or not the package substrate 200 is mounted on the jig chuck table 220 by comparing the measured negative pressure with the reference value. That is, for example, when a suction pump 19 having a suction force of −90 [kPa] is used to apply a negative pressure to the jig chuck table 220, the package substrate 200 is opened if the package substrate 200 is not mounted on the jig chuck table 220. Due to the leak from the suction hole 225, the negative pressure (vacuum degree) measured by the pressure sensor 87 becomes weak (for example, −20 [kPa]). Therefore, when the measured negative pressure does not reach a predetermined reference value (for example, −70 [kPa]) (weak), the determination unit 74 determines that the package substrate 200 is not mounted on the jig chuck table 220. be able to.

On the other hand, as shown in FIG. 3, the porous chuck table 120 is installed on the table base 18 so as to be replaceable with the jig chuck table 220. The porous chuck table 120 includes a table body 121 and a suction portion 122. The table body 121 is formed of metal into a disk shape. The suction portion 122 is made of porous ceramic or the like and is arranged at the center of the upper surface of the table body 121. The upper surface of the suction portion 122 serves as a holding surface 122A for sucking and holding the wafer 100 (frame unit 103). A first recess 126 facing the suction portion 122 is formed on the upper surface of the table body 121. Further, a second recess 127 facing the suction port 229 provided in the table base 18 is formed on the lower surface of the table body 121. The first recess 126 and the second recess 127 are communicated with each other by a communication hole 128. Since the internal configuration of the suction unit 17 and the determination mechanism 150 have the same configuration, the description thereof will be omitted.

The suction portion 122 described above is configured to include a large number of porous holes, and sucks and holds the wafer 100 (frame unit 103) on the entire holding surface 122A. The suction portion 122 of the porous chuck table 120 has a larger flow resistance at the time of suction than the jig chuck table 220. Therefore, when a negative pressure is applied to the porous chuck table 120 with a strong suction force (for example, −90 [kPa]) such as that of the suction pump 19, the wafer 100 (frame unit 103) is placed on the porous chuck table 120. Even if it is not listed, the negative pressure (vacuum degree) measured by the pressure sensor 87 may exceed the reference value (for example, -70 [kPa]) and become strong (for example, -75 [kPa]), and the porous chuck may be used. It becomes impossible to accurately determine whether or not the waha 100 (frame unit 103) is mounted on the table 120.

Therefore, in the present embodiment, when the porous chuck table 120 is installed on the table base 18, the on-off valve control unit 73 fully closes the second on-off valve 86 as shown in FIG. Then, the determination unit 74 acquires the negative pressure (vacuum degree) measured by the pressure sensor 87 in this state, and compares the negative pressure with the reference value. By fully closing the second on-off valve 86, the first branch path 83 is closed, so that the number of branch pipes that contribute to suction is reduced. Further, by arranging the second on-off valve 86 between the pressure sensor 87 and the branch point 82 (suction pump 19), the influence of the suction force of the suction pump 19 can be reduced. Therefore, the negative pressure (vacuum degree) measured by the pressure sensor 87 does not reach the reference value (for example, −70 [kPa]) and can be weak (for example, −50 [kPa]), and can be combined with the porous chuck table 120. Even in a configuration in which the jig chuck table 220 can be replaced, it is possible to accurately determine whether or not the wafer 100 (frame unit 103) is mounted on the porous chuck table 120.

Further, in the present embodiment, since the suction pump 19 is provided as the suction source, the package substrate 200 on the jig chuck table 220 can be reliably sucked and held.

The present invention is not limited to the description of the above embodiment and can be modified in various ways. For example, the structures of the porous chuck table 120 and the jig chuck table 220 are not limited to those shown in FIGS. 2 and 3, and existing structures of the porous chuck table and the jig chuck table can be adopted. Further, in the present embodiment, the second on-off valve 86 is controlled to be fully open or fully closed by the on-off valve control unit 73, but the operator may manually open or fully close the second on-off valve 86.

2 Cutting device 17 Suction unit 18 Table base 19 Suction pump (suction source)
20 Chuck table 60 Cutting unit 61 Cutting blade 72 Control unit 73 Open / close valve control unit 74 Judgment unit 81 Main suction path (suction path)
81A One end 81B The other end 82 Branch point 83 First branch road 83A One end 83B The other end 84 Second branch road 84A One end 84B The other end 85 First open / close valve 86 Second open / close valve 87 Pressure sensor (pressure gauge)
100 wafers (workpiece)
120 Porous chuck table 121 Table body 122 Adsorption part 122A Holding surface 150 Judgment mechanism 200 Package substrate (workpiece)
220 Jig Chuck Table 221 Holding Jig 222 Jig Base 223 Resin Sheet 223A Holding Surface 224 Relief Groove 225 Suction Hole

Claims (2)

A suction unit in which a chuck table for sucking and holding a work piece is replaceably fixed to a table base, a cutting unit for cutting a work piece held in the chuck table, and a work piece placed on the chuck table. The chuck table includes a porous chuck table that sucks and holds the workpiece on the porous surface, and a suction opening formed on the holding surface that sucks and holds the workpiece. It is a cutting device selected from the jig chuck table and
The adsorption unit is
A suction path with one end connected to the suction source and the other end connected to the branch point via the first open / close valve.
A first branch path, one end of which is connected to the branch point and the other end of which is connected to the table base to exert a negative pressure on the holding surface of the chuck table.
A second branch path is provided, one end of which is connected to the branch point and the other end of which is connected to the table base to exert a negative pressure on the holding surface of the chuck table.
The determination mechanism is
The second on-off valve provided in the first branch path and
A pressure gauge provided between the second on-off valve of the first branch path and the table base to measure the pressure of the first branch path, and
When the negative pressure measured by the pressure gauge does not reach the reference value with the first on-off valve open, a determination unit for determining that the workpiece is not placed on the chuck table, and
A cutting device including an on-off valve control unit that closes the second on-off valve when the determination unit makes a determination in a state where the porous chuck table is fixed to the table base. The cutting device according to claim 1, wherein the suction source is a suction pump.

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