TW202004880A - Cutting device capable of determining whether or not a workpiece is placed on a porous chuck table - Google Patents

Abstract

[Problem] To provide a cutting device that can accurately determine whether a workpiece is placed on a porous chuck table even in a configuration in which a porous chuck table can be exchanged with a jig chuck table. [Solution] The cutting device includes: a second switching valve 86, which is provided on the first branch 83; a pressure gauge 87, which is provided between the second switching valve 86 of the first branch 83 and the pedestal 18, and measures the first branch The pressure of the road 83; the determination unit 74 determines that the frame unit 103 is not placed on the porous chuck table when the negative pressure measured by the pressure gauge 87 does not reach the reference value when the first switching valve 85 is open 120; and the on-off valve control section 73, in a state where the porous chuck table 120 is fixed to the pedestal 18, when the judgment section 74 makes a judgment, the second on-off valve 86 is closed.

Description

Cutting device

The invention relates to a cutting device.

A cutting device (so-called dicer) for cutting various plate-shaped workpieces such as semiconductor wafers, resin-encapsulated substrates, ceramic or glass substrates with a dicing blade is widely known. In this type of cutting device, in order to prevent the cut work piece from scattering, the work piece is usually cut in a state where the work piece is fixed to the frame unit of the ring frame by a cutting glue film. The cutting device includes a porous chuck table provided on the pedestal, and the workpiece is uniformly attracted and held by the porous chuck table.

On the other hand, the above-mentioned dicing adhesive film becomes a cause of cost increase after being used up. In the case of cutting using a resin package substrate with a low wafer unit price as a workpiece, a jig chuck table can be installed on the pedestal The cutting device, the jig chuck table does not use cutting film. In order to attract and hold the wafers one by one, the fixture chuck table needs a strong vacuum force that does not allow each wafer to fly out, so a powerful suction source called a suction pump is used instead of the ejector used in the past. Furthermore, in general, the two chuck tables of the porous chuck table and the jig chuck table are used in their respective dedicated machines, but the industry expects that processing can be performed regardless of which chuck table. Therefore, in the past, there has been a proposal for a cutting device that can exchange a porous chuck table and a jig chuck table in accordance with the types of workpieces (for example, see Patent Document 1). [Conventional Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4851282

[Problems to be solved by the invention] Incidentally, in the above-mentioned cutting device, a so-called setup operation is performed so that the leading edge of the cutting blade contacts the upper surface of the chuck table to set the origin position of the cutting blade. When performing this setting operation, a suction source is used to apply negative pressure to the chuck table, and whether the workpiece is placed on the chuck table is determined by the strength of the negative pressure. That is, when the workpiece is not placed on the chuck table, even if negative pressure is applied but because of leakage, in general, the negative pressure in the pipeline connecting the suction source and the chuck table is low (weak). If the predetermined reference value is weak, it can be determined that the workpiece is not placed.

However, in the cutting device that can exchange two chuck tables as described above, the porous chuck table has a larger flow resistance during suction than the jig chuck table. Therefore, when a strong suction source such as a suction pump is used to apply negative pressure to the porous chuck table, the negative pressure in the pipeline will exceed the reference value and increase, and there is a problem that it is impossible to accurately determine whether the workpiece is placed on the chuck table .

In view of the above problems, the present invention aims to provide a cutting device that can accurately determine whether a workpiece is placed on a porous chuck table even in a configuration in which a porous chuck table can be exchanged with a jig chuck table .

[Technical means to solve the problem] In order to solve the above-mentioned problems and achieve the object, the present invention is a cutting device, comprising: an adsorption unit that exchangeably fixes a chuck table that attracts and holds a workpiece to a pedestal; a grinding unit that grinds the workpiece held by the chuck table; and The judging mechanism judges whether the workpiece is placed on the chuck table; the chuck table is a porous chuck table that sucks and holds the workpiece using the porous surface, and a fixture chuck that uses the suction opening formed by the holding surface to attract and hold the workpiece Selection in the platform; the suction unit is equipped with: a suction path, one end is connected to the suction source, and the other end is connected to the branch point through the first switch valve; the first branch path, one end is connected to the branch point, and the other end is connected to the pedestal and allows negative pressure to act on the The holding surface of the chuck table; and the second branch path, one end is connected to the branch point, and the other end is connected to the pedestal to apply negative pressure to the holding surface of the chuck table; the judging mechanism is provided with: a second switching valve, which is provided at The first branch circuit; a pressure gauge, which is provided between the second switching valve of the first branch circuit and the pedestal and measures the pressure of the first branch circuit; the determination unit, with the first switching valve open , When the negative pressure measured by the pressure gauge does not reach the reference value, it is determined that the workpiece is not placed on the chuck table; and the valve control section is opened and closed in the state where the porous chuck table is fixed to the base When the determination unit makes a determination, the second on-off valve is closed.

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

[Effect of invention] According to the cutting device of the present invention, by measuring the pressure of the first branch in a state where the second on-off valve is closed, the negative pressure measured by the pressure gauge can be suppressed from exceeding the reference value and becoming too strong, and It can correctly determine whether the workpiece is placed on the porous chuck table.

The method (embodiment) for implementing the present invention is explained in detail with reference to the drawings. The present invention is not limited to the content described in the following embodiments. In addition, the constituent elements described below include those that can be easily considered by those skilled in the art and are substantially the same. Furthermore, appropriate combinations can be made by the structures described below. In addition, various omissions, substitutions, or changes in the configuration within the scope of the gist of the present invention can be made.

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

A nut portion (not shown) is provided on the lower surface side of the X-axis moving table 10, and this nut portion is screwed to the X-axis ball screw 12 parallel to the X-axis guide rail 8. An X-axis pulse motor 14 is connected to one end of the X-axis ball screw 12. When the X-axis ball screw 12 is rotated by 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 side) of the X-axis moving table 10, through the θ table 16, a suction unit 17 that sucks and holds the workpiece to be processed is provided. In addition, the cutting device 2 is connected to a suction pump (suction source) 19 and is used to suck and hold a workpiece by the negative pressure action of the suction unit 17. The θ table 16 includes a rotational drive source (not shown) such as a motor, and rotates the suction unit 17 disposed on the upper portion of the θ table 16 around a substantially parallel rotation axis in the Z-axis direction (cutting direction). The suction pump 19 is, for example, a water-sealed vacuum pump that has a large suction power relative to the ejector vacuum pump and does not reduce the suction power even if it sucks water. In addition, the X-axis moving table 10 is moved in the X-axis direction by the X-axis moving mechanism 6 described above, whereby the suction unit 17 is processed and fed.

The suction unit 17 includes a pedestal 18 disposed above the θ table 16 and a chuck table 20 fixedly disposed on the pedestal 18. The structure of the chuck table 20 is that the porous chuck table 120 and the jig chuck table 220 can be interchangeably arranged on the pedestal 18 according to the type of the workpiece. Specifically, when processing the wafer 100 as a workpiece, the porous chuck table 120 is arranged on the pedestal 18. In addition, when the package substrate 200 is processed as a workpiece, the jig chuck table 220 is arranged on the pedestal 18. When it is not necessary to distinguish between the porous chuck table 120 and the jig chuck table 220, the chuck table 20 is simply used as the representation, and the porous chuck table 120 and the jig chuck table 220 will be described later.

The wafer 100 is, for example, as shown in FIG. 1, a disc-shaped semiconductor wafer or optical element wafer using silicon, sapphire, gallium, or the like as a base material. In the present embodiment, the wafer 100 is held on the porous chuck table 120 and processed in the state of the frame unit 103 supported by the ring frame 102 through the dicing film (adhesive film) 101 adhered to the back surface. In addition, although not shown in detail, a plurality of regions are divided by a plurality of planned dividing lines formed in a grid on the front surface of the wafer 100, and IC and LSI (Large Scale Integration) are formed on the divided regions , Large integrated circuits) and other components.

The configuration of the package substrate 200 is, for example, as shown in FIG. 1, and includes a substrate body 201 formed of a metal or ceramic or other rectangular flat plate, and a resin layer 202 laminated on the front side of the substrate body 201. In addition, although not shown in detail, a plurality of regions are divided by a plurality of planned dividing lines formed in a lattice shape on the substrate body 201, and elements such as IC and LSI are mounted on the divided regions. In addition, the resin layer 202 is made of a thermoplastic resin, and seals the element mounted on the front surface of the substrate body 201.

In addition, as shown in FIG. 2, a water tank 38 for temporarily storing waste liquid of the cutting liquid (for example, pure water, etc.) used in the cutting process is provided near the X-axis moving table 10. The waste liquid stored in the water tank 38 is discharged to the outside of the cutting device 2 through a drain pipe (not shown) or the like. A transport 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.

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

A nut portion (not shown) is provided on the back side of each Y-axis moving plate 46, and the nut portion is screwed to a Y-axis ball screw 48 that is substantially parallel to the Y-axis guide 44, respectively. 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 in the Z-axis direction are provided on the front (front) of each Y-axis moving plate 46. The Z-axis moving plate 54 is slidably mounted on the Z-axis guide 52. .

A nut portion (not shown) is provided on the back side of each Z-axis moving plate 54, and the nut portion is screwed to a Z-axis ball screw 56 that is substantially parallel to the Z-axis guide 52. 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 measurement unit (not shown) that measures the position of the Y-axis moving plate 46 in the Y-axis direction. In addition, each cutting unit moving mechanism 42 is provided with a Z-axis measuring unit (not shown) that measures 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. In addition, a camera (imaging unit) 62 for imaging the wafer 100 or the package substrate 200 is provided at a position adjacent to the dicing 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 perform index feed, and if the Z-axis moving plate 54 is moved in the Z-axis direction, cutting The unit 60 and the camera 62 perform plunge feed.

The cutting unit 60 includes a cutting blade 61 mounted on a rotating spindle (not shown) that is driven to rotate, and a cutting liquid supply nozzle 63 that supplies cutting liquid (for example, water) to the cutting blade 61. The rotating dicing blade 61 is supplied with a dicing liquid, and by moving the dicing blade 61 in the Z-axis direction and the Y-axis direction, the wafer 100 or the package substrate 200 is cut and each wafer is singulated.

The dicing device 2 includes a control unit 72 that controls the above-described components in accordance with the processing conditions of the workpiece (wafer 100 or package substrate 200). 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; central processing unit), executes a computer program stored in the ROM, and generates a control signal for controlling the cutting device 2, and the generated control signal is output to the input and output interface device to Each component of the cutting device 2.

Incidentally, before performing the cutting process, the cutting device 2 makes the cutting edge of the cutting blade 61 descending in the Z-axis direction contact the upper surface of the chuck table 20 (multi-hole chuck table 120 or jig chuck table 220). The Z-axis direction of the cutting blade 61 performs a setting operation for setting a so-called origin position. In the case of this setting, when the workpiece (wafer 100 or package substrate 200) is placed on the chuck table 20 and the cutting edge of the cutting blade 61 is brought into contact with the cutting edge, the cutting edge is damaged, erroneously cut, etc. The cutting blade 61 may cause damage to the workpiece, and it is determined whether the workpiece is placed on the chuck table 20. Therefore, the cutting device 2 includes a determination mechanism 150 that determines whether the workpiece is placed on the chuck table 20. Next, the determination unit 150 will be described. 2 is a schematic configuration diagram showing the internal structure of the suction unit and the determination mechanism when the jig chuck table is used. FIG. 3 is a schematic configuration diagram showing an internal structure of a suction unit and a determination mechanism when a porous chuck table is used.

As shown in FIG. 2, the jig chuck table 220 is installed on the base 18. The jig chuck table 220 includes a holding jig 221 and a jig base 222. The holding jig 221 is formed of metal into a rectangular shape, and a resin sheet 223 is arranged on the upper surface of the holding jig 221, and the upper surface of the resin sheet 223 becomes a holding surface 223A holding the package substrate 200. In addition, a plurality of relief grooves 224 are formed on the holding jig 221 and the resin sheet 223 at positions corresponding to the planned dividing line of the package substrate 200, and each of the areas divided by the crossed relief grooves 224 is formed with Suction hole 225 which the surface 223A penetrates to the back. The jig base 222 is formed of metal into a rectangular shape and is connected to the holding jig 221. A first recess 226 facing the suction hole 225 holding the jig 221 is formed on the upper surface of the jig base 222. In addition, a second concave portion 227 is formed on the lower surface of the jig base 222 to face the suction port 229 provided in the pedestal 18. The first concave portion 226 and the second concave portion 227 communicate with each other through a communication hole 228.

In addition, the suction unit 17 includes a jig chuck table 220 and a pedestal 18, and also includes a path 80 that connects the jig chuck table 220 and the suction pump 19. Specifically, the path 80 described above includes a main suction path (suction path) 81 whose one end 81A is connected to the suction pump 19 and the other end 81B connected to the branch point 82; and the first branch path 83 whose one end 83A is connected to the branch point 82, the other end 83B is connected to the suction port 229 of the pedestal 18; and the second branch 84 is arranged side by side with the first branch 83, its one end 84A is connected to the branch 82, and the other end 84B is connected to the suction port of the pedestal 18 229. In the present embodiment, the second branch path 84 is configured to have two parallel lines, but it is not limited to this, and it may be one or more than three.

The main suction path 81 is provided with a first switching valve 85 between the suction pump 19 and the branch point 82. In addition, a second switching valve 86 between the branch point 82 and the suction port 229 is provided on the first branch path 83, and a pressure sensor for measuring pressure is provided between the second switching valve 86 and the suction port 229 ( Pressure gauge) 87. The first on-off valve 85 is controlled by the on-off valve control section 73 of the control unit 72 to become a valve that completely opens or completely closes the main suction path 81. The second on-off valve 86 is controlled by the on-off valve control section 73 of the control unit 72, and becomes a valve that completely opens or completely closes the first branch 83. The pressure sensor 87 measures the negative pressure (pressure) in the path 80 (first branch 83), and outputs the measurement result to the determination unit 74 of the control unit 72.

When the suction pump 19 is operated, the negative pressure acts on the jig chuck table 220 through the main suction path 81, the first branch path 83, and the second branch path 84. The jig chuck table 220 is formed with a second concave portion 227, a communication hole 228, a first concave portion 226, and a suction hole 225, and this negative pressure acts on the package substrate 200 placed on the holding surface 223A through the above-mentioned members to attract and hold the package Substrate 200.

The configuration of 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 the package substrate 200 is placed on the jig chuck table 220 by comparing the measured negative pressure and the reference value. That is, for example, when a suction pump 19 having an attractive force of -90 [kPa] is used, when a negative pressure is applied to the jig chuck table 220, if the package substrate 200 is not placed on the jig chuck table 220 Then, the leakage from the open suction hole 225 weakens the negative pressure (vacuum degree) measured by the pressure sensor 87 (for example, -20 [kPa]). Therefore, when the determined negative pressure does not reach the predetermined reference value (for example, -70 [kPa]) (weak), the determination unit 74 may determine that the package substrate 200 is not placed on the jig chuck table 220.

On the one hand, as shown in FIG. 3, the porous chuck table 120 is installed on a pedestal 18 that can be exchanged with the jig chuck table 220. The porous chuck table 120 includes a table body 121 and a suction part 122. The stage body 121 is formed of metal into a circular plate shape. The suction portion 122 is made of porous ceramics or the like, and is disposed at the center of the upper surface of the table body 121. The upper surface of the suction unit 122 becomes a holding surface 122A that holds and holds the wafer 100 (frame unit 103 ). The upper surface of the stage body 121 is formed with a first concave portion 126 facing the suction portion 122. In addition, a second concave portion 127 facing the suction port 229 provided in the base 18 is formed on the lower surface of the base body 121. The first concave portion 126 and the second concave portion 127 communicate with each other through the communication hole 128. Since the internal configuration of the adsorption unit 17 and the determination mechanism 150 have the same configuration, the description is omitted.

The above-mentioned suction part 122 has a structure of a large number of porous holes, and the wafer 100 (frame unit 103) is suction-held by the entire holding surface 122A. The suction portion 122 of the porous chuck table 120 has a larger flow resistance than the jig chuck table 220 during suction. Therefore, in the case where negative pressure is applied to the porous chuck table 120 by a strong attractive force (for example, -90 [kPa]) such as the suction pump 19, even if the wafer 100 (frame unit 103) is not placed on the porous card On the table 120, the negative pressure (vacuum degree) measured by the pressure sensor 87 still exceeds the reference value (eg -70 [kPa]) and becomes stronger (eg -75 [kPa]), making it impossible to correctly determine the crystal Whether the circle 100 (frame unit 103) is placed on the porous chuck table 120.

Therefore, in the present embodiment, when the porous chuck table 120 is provided on the pedestal 18, the on-off valve control unit 73 completely closes the second on-off valve 86 as shown in FIG. 3. In this state, the determination unit 74 obtains the negative pressure (vacuum degree) measured by the pressure sensor 87 and compares the negative pressure with the reference value. Since the second on-off valve 86 is completely closed, the first branch 83 is closed, so the number of branch pipes that are favorable for attraction is reduced. Furthermore, 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 attraction of the suction pump 19 can be reduced. Therefore, the negative pressure (vacuum degree) measured by the pressure sensor 87 can be set to a weak value (for example, -50 [kPa]) that does not reach the reference value (for example, -70 [kPa]), even if it is an exchangeable porous card The structure of the chuck table 120 and the jig chuck table 220 can also accurately determine whether the wafer 100 (frame unit 103) is placed on the porous chuck table 120.

In addition, in this embodiment, since the suction pump 19 is provided as a suction source, the package substrate 200 on the jig chuck table 220 can be surely sucked and held.

In addition, the present invention is not limited to the description of the above-mentioned embodiments and the like, and various implementations with various modifications are possible. For example, the configurations of the porous chuck table 120 and the jig chuck table 220 are not limited to the structures shown in FIGS. 2 and 3, and the structure of the existing porous chuck table and the jig chuck table can be adopted. In addition, in the present embodiment, although the second on-off valve 86 is fully opened or completely closed by the on-off valve control unit 73, the operator may be fully opened or completely closed manually.

2‧‧‧Cutting device 17‧‧‧Adsorption unit 18‧‧‧pedestal 19‧‧‧ Suction pump (attraction source) 20‧‧‧Chuck table 60‧‧‧Cutting unit 61‧‧‧Cutting blade 72‧‧‧Control unit 73‧‧‧ On-off valve control department 74‧‧‧Judgment Department 81‧‧‧Main attraction road (attraction road) 81A‧‧‧ One end of the main attraction 81B‧‧‧The other end of the main attraction 82‧‧‧ Divergence 83‧‧‧ First branch 83A‧‧‧One end of the first branch 83B‧‧‧The other end of the first branch 84‧‧‧The second branch 84A‧‧‧One end of the 2nd branch 84B‧‧‧The other end of the second branch 85‧‧‧The first switch valve 86‧‧‧The second switch valve 87‧‧‧ pressure sensor (pressure gauge) 100‧‧‧wafer (workpiece) 120‧‧‧Porous chuck table 121‧‧‧ units 122‧‧‧Adsorption Department 122A‧‧‧Keep 150‧‧‧judgment organization 200‧‧‧Package substrate (workpiece) 220‧‧‧ Fixture chuck table 221‧‧‧Keep fixture 222‧‧‧ Fixture base 223‧‧‧Resin sheet 223A‧‧‧Keep the surface 224‧‧‧recess 225‧‧‧ Suction hole

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

17‧‧‧Adsorption unit

18‧‧‧pedestal

19‧‧‧ Suction pump (suction source)

72‧‧‧Control unit

73‧‧‧ On-off valve control department

74‧‧‧Judgment Department

80‧‧‧path

81‧‧‧Main attraction road (attraction road)

81B‧‧‧The other end of the main attraction

82‧‧‧ Divergence

83A‧‧‧One end of the first branch

83B‧‧‧The other end of the first branch

84A‧‧‧One end of the 2nd branch

84B‧‧‧The other end of the second branch

85‧‧‧The first switch valve

86‧‧‧The second switch valve

87‧‧‧ pressure sensor (pressure gauge)

100‧‧‧wafer (workpiece)

101‧‧‧Cutting film

102‧‧‧Ring frame

103‧‧‧Frame unit

120‧‧‧Porous chuck table

121‧‧‧ units

122‧‧‧Adsorption Department

122A‧‧‧Keep

229‧‧‧ attraction

Claims (2)

A cutting device includes: an adsorption unit that exchangeably fixes a chuck table that attracts and holds a workpiece to a pedestal; a grinding unit that grinds the workpiece held by the chuck table; and a determination mechanism that determines whether the workpiece is placed on the Chuck table; the chuck table is selected from a porous chuck table that uses a porous surface to attract and hold a workpiece, and a fixture chuck table that uses a suction opening formed by the holding surface to attract and hold a workpiece; The adsorption unit has: The suction circuit, one end is connected to the suction source, and the other end is connected to the branch point through the first switch valve; The first branch path, one end is connected to the branch point, and the other end is connected to the pedestal and allows negative pressure to act on the holding surface of the chuck table; and The second branch path, one end is connected to the branch point, and the other end is connected to the pedestal and allows negative pressure to act on the holding surface of the chuck table; The judging body has: The second switch valve is set on the first branch; A pressure gauge, which is provided between the second on-off valve of the first branch and the base and measures the pressure of the first branch; The determination unit determines that the workpiece is not placed on the chuck table when the negative pressure measured by the pressure gauge does not reach the reference value when the first on-off valve is open; and The on-off valve control unit closes the second on-off valve when the determination unit makes a determination in the state where the porous chuck table is fixed to the pedestal. The cutting device according to item 1 of the patent application scope, wherein the suction source is a suction pump.

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