Workpiece suction device

Abstract

To provide a workpiece suction device capable of sucking a warped workpiece effectively at a low cost without damaging to the warping workpiece.SOLUTION: A workpiece suction device comprises: a work table 16 that can suck a warping workpiece W; an ejector 64 that generates a negative pressure in order to suck the warping workpiece W; a first negative pressure line 66 that communicates a space between the ejector 64 and the work table 16; a second negative pressure line 68 that is constructed separately from the first negative pressure line 66, and is communicated with the work table 16; a vacuum tank 80 that is provided at the second negative pressure line 68; and a negative pressure control part that selectively switches a first operation that supplies the negative pressure generated by the ejector 64 to the work table 16 and a second operation that supplies the negative pressure of the vacuum tank 80 to the work table 16, in the case where the warping workpiece W is sucked by the work table 16.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a workpiece suction device, and more particularly to a workpiece suction device mounted on a dicing device for dicing a workpiece. [Background technology]

[0002] A dicing device that divides a workpiece, such as a wafer on which semiconductor devices or electronic components are formed, into individual chips is equipped with, for example, a spindle motor that rotates a blade at high speed, a worktable that suctions and holds the workpiece, and X, Y, Z, and θ drive units that change the relative position between the spindle motor and the worktable. In the dicing device, the blade cuts into the workpiece to perform dicing (cutting) while the blade and the workpiece are moved relatively by the drive units.

[0003] Patent Document 1 discloses a workpiece suction device mounted on a dicing device. This workpiece suction device has a porous chuck and a vacuum source, and when the vacuum source is activated, a vacuum suction force is generated between an adherend placed on the porous chuck and the suction surface of the porous chuck, thereby suctioning and holding the adherend on the suction surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-145088 A Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, in a dicing device, there is a demand for the ability to stably perform dancing processing even when processing a workpiece with a large warp (hereinafter referred to as a warped workpiece), such as a workpiece in which a metal layer and a semiconductor layer are bonded together or a package substrate.

[0006] Here, when a warped workpiece is placed on a flat suction surface, an air escape route is formed between the suction surface and the warped workpiece, making it difficult to attach the warped workpiece to the suction surface. In order to solve this problem, it is possible to force the warped workpiece to be attached to the suction surface by pressing the warped workpiece against the suction surface or by using a vacuum pump that generates a large negative pressure.

[0007] However, the method of pressing the warped workpiece against the suction surface may damage the components (electronic components, etc.) mounted on the workpiece. In addition, the method of using a vacuum pump has the problem of incurring cost waste because the vacuum pump must be continuously used, even though once the warped workpiece is suctioned onto the suction surface, a high exhaust speed from the vacuum pump is no longer necessary (in other words, once the negative pressure is stabilized at a high level, the warped workpiece can be suctioned and held at a low exhaust speed).

[0008] The present invention has been made in consideration of such problems, and has an object to provide a workpiece suction device that can suction a warped workpiece efficiently at low cost without damaging the warped workpiece. [Means for solving the problem]

[0009] In order to achieve the object of the present invention, the workpiece adsorption device of the present invention comprises a worktable capable of adsorbing a workpiece, a negative pressure generating unit that generates negative pressure for adsorbing the workpiece, a first negative pressure line that connects between the negative pressure generating unit and the worktable, a second negative pressure line that is configured separately from the first negative pressure line and connects between the negative pressure generating unit and the worktable, a vacuum tank provided in the second negative pressure line, and a negative pressure control unit that selectively switches between a first operation of supplying the negative pressure generated by the negative pressure generating unit to the worktable and a second operation of supplying the negative pressure of the vacuum tank to the worktable when adsorbing the workpiece to the worktable.

[0010] In one aspect of the present invention, when adsorbing the workpiece to the worktable, the negative pressure control unit preferably temporarily performs the second operation and then performs only the first operation.

[0011] In one aspect of the present invention, it is preferable that the negative pressure control unit starts the first operation before the timing at which the second operation is started.

[0012] In one aspect of the present invention, a first flow control valve is preferably provided on the second negative pressure line closer to the work table than the vacuum tank.

[0013] In one aspect of the present invention, it is preferable that the negative pressure control unit supplies the negative pressure generated by the negative pressure generating unit to the vacuum tank when the second operation is stopped.

[0014] Preferably, one aspect of the present invention further comprises a second flow control valve provided on the second negative pressure line closer to the negative pressure generating unit than the vacuum tank. Effect of the Invention

[0015] According to the present invention, it is possible to efficiently adsorb a warped workpiece at low cost without damaging the warped workpiece. [Brief description of the drawings]

[0016] [Figure 1] 1 is an overall perspective view of a dicing apparatus equipped with a workpiece suction device according to an embodiment of the present invention; [Diagram 2] 2 is a perspective view showing a configuration of a processing unit of the dicing apparatus shown in FIG. 1. [Diagram 3] 2 is a functional block diagram showing an electrical configuration of the dicing device shown in FIG. 1. [Figure 4] FIG. 1 is a schematic diagram illustrating a configuration of a workpiece suction device according to an embodiment. [Diagram 5] 5 is a timing chart showing an example of an operation of the workpiece suction device of the embodiment. [Figure 6] FIG. 11 is a schematic diagram showing the configuration of a first modified example of a workpiece suction device. [Figure 7] FIG. 11 is a schematic view showing the configuration of a second modified example of a workpiece suction device. [Figure 8]FIG. 13 is a schematic view showing the configuration of a third modified example of a workpiece suction device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of a workpiece suction device according to the present invention will be described with reference to the accompanying drawings.

[0018] 1 is an overall perspective view of a dicing apparatus 10 equipped with a workpiece suction device according to an embodiment of the present invention. First, the configuration of the dicing apparatus 10 will be described.

[0019] As shown in Fig. 1, the dicing device 10 of this example is a dicing device called a twin spindle dicer in which a pair of blades 12, 12 are arranged facing each other. This dicing device 10 is equipped with a processing unit 18 having a pair of spindles 14, 14 with a built-in high-frequency motor and a blade 12 fixed to the tip, and a work table 16 on which a workpiece (hereinafter also referred to as a warped workpiece) W is placed and which suction-holds the workpiece W. This processing unit 18 dices the workpiece W with the blade 12 while moving the workpiece W and the blade 12 relative to each other.

[0020] The dicing apparatus 10 also includes a cleaning unit 20 that spin-cleans the processed workpiece W, a load port 22 on which a cassette containing a plurality of workpieces W is placed, and a transport device 24 that transports the workpieces W, all of which are disposed at predetermined positions. The dicing apparatus 10 also includes a built-in control unit 26 that controls the overall operation of each component of the dicing apparatus 10.

[0021] Fig. 2 is a perspective view showing the structure of the processing unit 18. As shown in Fig. 2, the processing unit 18 is equipped with an X-table 34. The X-table 34 is guided by X-guides 30, 30 provided on the X-base 28, and is driven in the X-direction indicated by the arrow XX by a linear motor 32. In addition, a rotary table 36 that rotates in the θ-direction is fixed to the upper surface of the X-table 34, and the work table 16 is provided on this rotary table 36. Therefore, the work table 16 is moved in the X-direction by the X-table 34, and rotated in the θ-direction by the rotary table 36.

[0022] Furthermore, processing unit 18 is equipped with a Y base 38 configured in a gate shape so as to straddle X base 28. Y tables 42, 42 are provided on the wall surface of Y base 38. Y tables 42, 42 are guided by Y guides 40, 40 fixed to the wall surface of Y base 38, and are driven in the Y direction indicated by arrow YY by a drive device made up of a stepping motor and a ball screw (not shown).

[0023] The Y tables 42 are provided with Z tables 44, respectively. The Z tables 44 are guided by Z guides (not shown) provided on the Y table 42, and are driven in the Z direction indicated by the arrow ZZ by a drive device (not shown) consisting of a stepping motor and a ball screw. Spindles 14 are fixed to the Z tables 44, and blades 12 attached to the tips of the spindles 14 are disposed to face each other.

[0024] With the above-described configuration of the processing unit 18, the blades 12, 12 are indexed in the Y direction and cut in the Z direction, and the work table 16 is cut in the X direction and rotated in the θ direction. By such operation of the processing unit 18 and the rotating blades 12, 12, a checkerboard-like groove (kerf) is cut into the surface of the workpiece W.

[0025] Fig. 3 is a functional block diagram showing the electrical configuration of the dicing apparatus 10 shown in Fig. 1. As shown in Fig. 3, the control unit 26 of the dicing apparatus 10 includes a system control unit 50, a processing control unit 52, an ejector control unit 54, a valve control unit 56, and a computer-readable medium 58.

[0026] The system control unit 50 provides overall control over the various control units provided in the control unit 26. The system control unit 50 also controls the writing of data, etc. to the computer-readable medium 58 and the reading of data, etc. from the computer-readable medium 58.

[0027] The machining control unit 52 controls the operation of various drive members such as the machining unit 18 (see FIG. 2), the cleaning unit 20 (see FIG. 1), and the transport device 24. The ejector control unit 54 controls the operation of an ejector 64 of the workpiece adsorption device, which will be described later. The valve control unit 56 (an example of a negative pressure control unit of the present invention) controls the operation of various valves (solenoid valves V1 to V4, flow control valves 82, 84, 88) of the workpiece adsorption device. The operation control of the ejector 64 by the ejector control unit 54 and the operation control of various valves by the valve control unit 56 will be described later. Note that the operation control of various drive members by the machining control unit 52 is well known, so a detailed explanation will be omitted.

[0028] A computer is applied to the hardware of the control unit 26. The computer functioning as the control unit 26 includes one or more processors and one or more computer-readable media 58. The computer realizes the functions of each part in the control unit 26 by causing the processor to execute a program including one or more instructions stored in the computer-readable medium 58.

[0029] In the control unit 26, one processing unit or two or more processing units may be realized using one processor, or one processing unit may be realized using multiple processors. The processor may be a CPU (Central Processing Unit) which is a general-purpose processing device, or a processing device specialized for a specific process. The multiple processors may be of the same type, or may be of multiple different types.

[0030] The computer-readable medium 58 includes a memory serving as a main storage device and a storage serving as an auxiliary storage device. The computer-readable medium 58 may also use a semiconductor memory, a hard disk drive, a solid-state drive, or the like. Furthermore, the computer-readable medium 58 may use any combination of multiple devices.

[0031] Next, a workpiece suction device according to an embodiment will be described. Fig. 4 is a schematic diagram showing the configuration of a workpiece suction device 60 according to an embodiment. First, the schematic configuration of the workpiece suction device 60 will be described.

[0032] 4, the workpiece suction device 60 of the embodiment is mainly composed of a worktable 16, an ejector 64, and a negative pressure supply line 74. The worktable 16 is provided with a porous chuck 62 that adsorbs the workpiece W by vacuum suction force. The ejector 64 generates negative pressure for generating a vacuum suction force in the porous chuck 62. The ejector 64 is started and stopped by a signal provided from the ejector control unit 54.

[0033] The negative pressure supply line 74 is a line that communicates between the work table 16 (porous chuck 62) and the ejector 64. The work table 16 is an example of the work table of the present invention. The ejector 64 is an example of the negative pressure generating unit of the present invention.

[0034] The negative pressure supply line 74 has two negative pressure supply lines 66, 68 (hereinafter simply referred to as negative pressure lines 66, 68). The two negative pressure lines 66, 68 are lines branching off from the negative pressure supply line 74 on the upstream side (ejector 64 side) at a branching section 70. The two negative pressure lines 66, 68 join together at a joining section 72 and are connected to the negative pressure supply line 74 on the downstream side (work table 16 side). In the following description, the entire negative pressure supply line including the two negative pressure lines 66, 68 will be referred to as the "negative pressure supply line 74." In addition, the line of the negative pressure supply line 74 upstream of the branching portion 70 (the line connecting the ejector 64 and the branching portion 70) is referred to as the upstream negative pressure supply line 76, and the line downstream of the junction 72 (the line connecting the junction 72 and the work table 16 (porous chuck 62)) is referred to as the downstream negative pressure supply line 78.

[0035] Of the two negative pressure lines 66, 68, one negative pressure line 66 (hereinafter referred to as the first negative pressure line 66) is a negative pressure supply line for directly supplying the negative pressure (small suction amount) of the ejector 64 to the work table 16, and is connected to the porous chuck 62 of the work table 16 via a downstream negative pressure supply line 78. The other negative pressure line 68 (hereinafter referred to as the second negative pressure line 68) is a negative pressure supply line for supplying the negative pressure (large suction amount) of a vacuum tank 80 described later to the work table 16, and is configured separately from the first negative pressure line 66 and is connected to the porous chuck 62 of the work table 16 via the downstream negative pressure supply line 78. The respective negative pressures supplied from the first negative pressure line 66 and the second negative pressure line 68 are supplied to the porous chuck 62 of the work table 16 via the downstream negative pressure supply line 78. The first negative pressure line 66 and the second negative pressure line 68 are examples of the first negative pressure line and the second negative pressure line of the present invention, respectively.

[0036] As shown in FIG. 4, the first negative pressure line 66 is provided with a first solenoid valve V1. The first solenoid valve V1 is opened and closed by a signal provided from the valve control unit 56. When the first solenoid valve V1 is opened, the ejector 64 and the work table 16 are in communication with each other via the first negative pressure line 66, and the negative pressure generated by the ejector 64 can be supplied to the porous chuck 62 of the work table 16 via the first negative pressure line 66. On the other hand, when the first solenoid valve V1 is closed, the ejector 64 and the work table 16 are not in communication with each other via the first negative pressure line 66, and the supply of negative pressure from the ejector 64 to the porous chuck 62 of the work table 16 via the first negative pressure line 66 becomes impossible.

[0037] As shown in FIG. 4, the second negative pressure line 68 is provided with, in order from the upstream side (the branching section 70 side) to the downstream side (the confluence section 72 side), a third solenoid valve V3, a second flow control valve 84, a vacuum tank 80, a second solenoid valve V2, and a first flow control valve 82.

[0038] The vacuum tank 80 is disposed midway along the second negative pressure line 68 located between the ejector 64 and the work table 16 so as to instantaneously supply a negative pressure greater than the negative pressure supplied via the first negative pressure line 66 to the porous chuck 62 of the work table 16. The vacuum tank 80 is an example of the vacuum tank of the present invention.

[0039] The second solenoid valve V2 is disposed downstream (the junction 72 side) of the vacuum tank 80 in the second negative pressure line 68. The second solenoid valve V2 opens and closes in response to a signal provided from the valve control unit 56. When the second solenoid valve V2 is opened, the vacuum tank 80 and the work table 16 are in communication with each other via the second negative pressure line 68 (downstream of the vacuum tank 80), and the negative pressure of the vacuum tank 80 can be supplied to the porous chuck 62 of the work table 16. On the other hand, when the second solenoid valve V2 is closed, the vacuum tank 80 and the work table 16 are not in communication with each other via the second negative pressure line 68 (downstream of the vacuum tank 80), and the supply of negative pressure from the vacuum tank 80 to the porous chuck 62 of the work table 16 becomes impossible.

[0040] The first flow control valve 82 is disposed downstream of the vacuum tank 80 in the second negative pressure line 68 (on the junction 72 side). Specifically, the first flow control valve 82 is disposed downstream of the vacuum tank 80 in the second negative pressure line 68 between the second solenoid valve V2 and the junction 72. The first flow control valve 82 is for adjusting the negative pressure supplied from the vacuum tank 80 to the porous chuck 62 of the work table 16. The opening degree of the first flow control valve 82 is adjusted by a signal given from the valve control unit 56. When the first flow control valve 82 is adjusted in the opening direction, the negative pressure supplied from the vacuum tank 80 to the porous chuck 62 of the work table 16 becomes higher. On the other hand, when the first flow control valve 82 is adjusted in the closing direction, the negative pressure supplied from the vacuum tank 80 to the porous chuck 62 of the work table 16 becomes lower. The first flow control valve 82 is an example of the first flow control valve of the present invention.

[0041] The third solenoid valve V3 is disposed upstream (on the branch section 70 side) of the vacuum tank 80 in the second negative pressure line 68. The third solenoid valve V3 opens and closes in response to a signal provided from the valve control section 56. When the third solenoid valve V3 is opened, the ejector 64 and the vacuum tank 80 communicate with each other via the second negative pressure line 68 (upstream of the vacuum tank 80), and the negative pressure generated by the ejector 64 can be supplied to the vacuum tank 80. Therefore, when the third solenoid valve V3 is opened with the second solenoid valve V2 closed, the negative pressure generated by the ejector 64 is supplied to the vacuum tank 80. As a result, negative pressure is accumulated in the vacuum tank 80, and the negative pressure in the vacuum tank 80 increases. On the other hand, when the third solenoid valve V3 is closed, the ejector 64 and the vacuum tank 80 are not connected via the second negative pressure line 68 (upstream of the vacuum tank 80), and it becomes impossible to supply negative pressure from the ejector 64 to the vacuum tank 80.

[0042] The second flow control valve 84 is disposed upstream of the vacuum tank 80 in the second negative pressure line 68 (on the branch section 70 side). Specifically, the second flow control valve 84 is disposed between the third solenoid valve V3 and the vacuum tank 80, upstream of the vacuum tank 80 in the second negative pressure line 68. The second flow control valve 84 is for adjusting the negative pressure supplied from the ejector 64 to the vacuum tank 80. The opening degree of the second flow control valve 84 is adjusted by a signal given from the valve control section 56. When the second flow control valve 84 is adjusted in the opening direction, the negative pressure supplied from the ejector 64 to the vacuum tank 80 becomes higher. On the other hand, when the second flow control valve 84 is adjusted in the closing direction, the negative pressure supplied from the ejector 64 to the vacuum tank 80 becomes lower. The second flow control valve 84 is an example of the second flow control valve of the present invention.

[0043] 4, the downstream negative pressure supply line 78 is a line that communicates between the porous chuck 62 of the work table 16 and the junction 72. In this example, the downstream negative pressure supply line 78 communicates with the porous chuck 62 of the work table 16 via a rotary joint 17 for supporting the rotation of the work table 16. A vacuum break line 86 is connected to the downstream negative pressure supply line 78 at a midpoint between the porous chuck 62 of the work table 16 and the junction 72.

[0044] The vacuum break line 86 is a line provided to release the vacuum suction of the workpiece W by the porous chuck 62 of the worktable 16, and includes a third flow control valve 88, a fourth solenoid valve V4, and a compressed air supply source 90. For example, when releasing the vacuum suction of the workpiece W, the fourth solenoid valve V4 is opened, and compressed air from the compressed air supply source 90 is supplied to the vacuum break line 86. At that time, the flow rate of the compressed air supplied from the compressed air supply source 90 is adjusted by the third flow control valve 88. Then, the compressed air whose flow rate is adjusted by the third flow control valve 88 is supplied from the vacuum break line 86 to the porous chuck 62 of the worktable 16 via the downstream negative pressure supply line 78. This releases the vacuum suction of the workpiece W by the porous chuck 62 of the worktable 16. The fourth solenoid valve V4 opens and closes according to a signal given from the valve control unit 56. The opening degree of the third flow control valve 88 is adjusted according to a signal given from the valve control unit 56.

[0045] 4, the workpiece suction device 60 of this example has a tank pressure sensor that detects the pressure of the vacuum tank 80, and a table pressure sensor that detects the pressure of the porous chuck 62 (hereinafter also referred to as the pressure of the work table 16). As an example, the tank pressure sensor is attached to the vacuum tank 80, and the table pressure sensor is attached to the downstream negative pressure supply line 78. However, the attachment positions of the pressure sensors are not limited to these positions, and may be any positions where the above pressures can be detected.

[0046] Next, an example of an operation in which the warped workpiece W is attracted to the work table 16 by the workpiece suction device 60 of the embodiment will be described with reference to the timing chart shown in Fig. 5. In the following description, the "work table 16" essentially means the "porous chuck 62".

[0047] The timing chart shown in Fig. 5 shows the opening and closing operations (OPEN-CLOSE) of the first solenoid valve V1, the second solenoid valve V2, the third solenoid valve V3, and the fourth solenoid valve V4. Fig. 5 also shows the pressures of the vacuum tank 80 and the work table 16, which change in response to the opening and closing operations of the solenoid valves V1 to V4. The pressure of the vacuum tank 80 is detected by a tank pressure sensor, and the pressure of the work table 16 is detected by a table pressure sensor.

[0048] 5, the steps performed by the workpiece suction device 60 include, for example, a preparation step, a suction step, a processing step, and a vacuum break step. These steps are repeatedly performed for each warped workpiece W.

[0049] First, the preparation process will be described. If the start time of the preparation process is T0, at T0, each of the solenoid valves V1 to V4 is closed. The pressure in the vacuum tank 80 is atmospheric pressure, and the pressure in the work table 16 is also atmospheric pressure. The ejector 64 (see FIG. 4) is started in advance by the ejector control unit 54.

[0050] In the preparation process, the third solenoid valve V3 is opened at T1 after a predetermined time has elapsed from T0. Then, the vacuum tank 80 is connected to the ejector 64 via the upstream part of the second negative pressure line 68 (upstream side of the vacuum tank 80), so that the negative pressure of the ejector 64 is supplied to the vacuum tank 80. That is, the air in the vacuum tank 80 is sucked by the ejector 64. As a result, the pressure of the vacuum tank 80 is gradually reduced from the atmospheric pressure, and the third solenoid valve V3 is closed at T2, which indicates that the pressure of the vacuum tank 80 has reached, for example, about -90 kPa. As a result, the pressure of the vacuum tank 80 is set to a negative pressure (for example, about -90 kPa) that can adsorb the warped workpiece W. In this example, the third solenoid valve V3 is closed (time controlled) when T2 is measured, but this is not limited to this, and the third solenoid valve V3 may be closed based on the detection value (pressure) detected by the tank pressure sensor. For example, the third solenoid valve V3 may be closed when the pressure detected by the tank pressure sensor is −90 kPa.

[0051] Next, the suction process is performed. The suction process starts at time T3 when the warped workpiece W is placed on the worktable 16 by the transport device 24 (see FIG. 1), and the first solenoid valve V1 is opened at time T4 after a predetermined time has elapsed from T3. Then, the worktable 16 is connected to the ejector 64 via the first negative pressure line 66. This causes an operation to supply the negative pressure generated by the ejector 64 to the worktable 16 (hereinafter referred to as the ejector negative pressure supply operation), and the pressure of the worktable 16 is reduced from atmospheric pressure to negative pressure. At this time, the pressure (negative pressure) detected by the table pressure sensor is, for example, about -20 kPa, so that the warped workpiece W is not suctioned to the worktable 16. The ejector negative pressure supply operation is an example of the first operation of the present invention.

[0052] Then, at T5, a predetermined time after T4, the second solenoid valve V2 is opened. Then, the vacuum tank 80 is connected to the work table 16 via the downstream part of the second negative pressure line 68 (downstream side of the vacuum tank 80). As a result, the vacuum tank 80 in a vacuum state is broken, and an operation is performed in which the negative pressure (for example, about -90 kPa) of the vacuum tank 80 is supplied to the work table 16 via the downstream part of the second negative pressure line 68 (hereinafter referred to as a vacuum tank negative pressure supply operation), and a vacuum suction force is generated in the space between the work table 16 and the warped workpiece W. As a result, the warp of the warped workpiece W is corrected to be flat by the vacuum suction force and the warp is adsorbed to the work table 16. The vacuum tank negative pressure supply operation is an example of the second operation of the present invention.

[0053] The opening of the second solenoid valve V2 in the adsorption process is performed from T5 to T6 after the lapse of a specified period. That is, the second solenoid valve V2 is closed at T6. During the above-mentioned specified period (the period from T5 to T6), the pressure of the vacuum tank 80 detected by the tank pressure sensor rises to a certain extent immediately after T5, but when the warped workpiece W is adsorbed to the work table 16, the rise stops and the pressure gradually drops due to the exhaust operation of the ejector 64 communicated via the first solenoid valve V1. The pressure of the work table 16 detected by the table pressure sensor is rapidly reduced immediately after T5, but when the warped workpiece W is adsorbed to the work table 16, the rapid drop stops and the pressure gradually drops due to the exhaust operation of the ejector 64 communicated via the first solenoid valve V1. The above-mentioned specified period (the period from T5 to T6) is a period required to adsorb the warped workpiece W to the work table 16, and is obtained in advance by an experiment or the like, for example. Incidentally, the first solenoid valve V1 remains opened from T4 even after T6 has elapsed, and the ejector negative pressure supply operation is continuously performed.

[0054] Next, the machining process (cutting process) is executed. The machining process starts at T7, which indicates that the adsorption of the warped workpiece W is completed. During the entire period of the machining process, the first solenoid valve V1 remains open from T4 of the adsorption process. The second solenoid valve V2 remains closed from T6 of the adsorption process, and the third solenoid valve V3 remains closed from T2 of the preparation process. As a result, only the negative pressure generated by the ejector 64 is supplied to the work table 16 during the entire period of the machining process. That is, in the machining process, the vacuum tank negative pressure supply operation is not performed, and only the ejector negative pressure supply operation is performed. In this example, the adsorption completion of the warped workpiece W is determined (time control) when T7 is measured, but this is not limited to this, and the adsorption completion may be determined based on the detection value (pressure) detected by the table pressure sensor. For example, the adsorption completion may be determined when the pressure detected by the table pressure sensor is maintained at -90 kPa for a predetermined period.

[0055] In this way, by supplying only the negative pressure of the ejector 64 to the work table 16 without supplying the negative pressure of the vacuum tank 80 to the work table 16 during the entire period of the machining process, the pressure on the work table 16 is maintained at a negative pressure (for example, about -90 kPa) at which the warped workpiece W can be adsorbed and held on the work table 16. Therefore, the warped workpiece W is cut while being adsorbed and held on the work table 16 only by the negative pressure of the ejector 64.

[0056] Next, the vacuum breaking process is executed. The vacuum breaking process starts at time T8 when the first solenoid valve V1 is closed, and the fourth solenoid valve V4 (see FIG. 4) is opened at time T9 after a predetermined time has elapsed from T8. Then, compressed air from the compressed air supply source 90 is supplied to the vacuum breaking line 86, and the compressed air whose flow rate is adjusted by the third flow control valve 88 is supplied to the work table 16 via the downstream negative pressure supply line 78. This breaks the vacuum in the work table 16, and the pressure of the work table 16 becomes equal to or higher than atmospheric pressure. As a result, the vacuum suction of the warped workpiece W by the work table 16 is released. Then, the warped workpiece W is carried out.

[0057] After that, at T10, the fourth solenoid valve V4 is closed, and the pressure on the work table 16 is returned to atmospheric pressure, after which the warped workpiece W is removed from the work table 16 by the conveying device 24 (FIG. 1). The above is the operation of the workpiece suction device 60 for one warped workpiece W. After that, the same process is repeatedly executed for the second and subsequent warped workpieces W.

[0058] As described above, according to the workpiece suction device 60 of the embodiment, when the warped workpiece W is suctioned to the worktable 16, the ejector negative pressure supply operation (first operation) and the vacuum tank negative pressure supply operation (second operation) can be selectively switched. This makes it possible to temporarily supply the negative pressure (large suction amount) of the vacuum tank 80 by the vacuum tank negative pressure supply operation, and then only supply the negative pressure (small suction amount) of the ejector 64 by the ejector negative pressure supply operation. As a result, it becomes possible to suction the warped workpiece W efficiently at low cost without damaging the warped workpiece W.

[0059] Moreover, according to the workpiece suction device 60 of the embodiment, the ejector negative pressure supply operation is started before the timing when the vacuum tank negative pressure supply operation is started. Therefore, the negative pressure of the ejector 64 can be introduced in advance before the negative pressure of the vacuum tank 80 is supplied to the worktable 16 (porous chuck 62). This makes it possible to quickly reduce the pressure of the worktable 16 (porous chuck 62) to a desired negative pressure state when the supply of the negative pressure of the vacuum tank 80 is started, and the suction process can be shortened.

[0060] In the embodiment of the workpiece suction device 60, the ejector negative pressure supply operation is started before the vacuum tank negative pressure supply operation is started, but this is not limited thereto, and the ejector negative pressure supply operation may be started at least before the vacuum tank negative pressure supply operation is completed. For example, the ejector negative pressure supply operation may be started while the vacuum tank negative pressure supply operation is being performed. In this way, by starting the ejector negative pressure supply operation at least before the vacuum tank negative pressure supply operation is completed, the negative pressure of the ejector 64 is supplied even after the warped workpiece W is suctioned using the negative pressure of the vacuum tank 80, so that the negative pressure of the vacuum tank 80 is instantly switched to the negative pressure of the ejector 64 without any time lag. This makes it possible to stably suction and hold the warped workpiece W using only the negative pressure of the ejector 64.

[0061] Furthermore, according to the workpiece suction device 60 of the embodiment, a configuration is adopted in which the first flow control valve 82 is provided downstream (the junction 72 side) of the vacuum tank 80 in the second negative pressure line 68, so that the impact when the vacuum tank 80 in a vacuum state is broken can be suppressed (mitigated) by the first flow control valve 82. This makes it possible to prevent damage to the warped workpiece W caused by the impact of the vacuum break.

[0062] According to the embodiment of the workpiece suction device 60, the negative pressure supply line 74 communicating between the ejector 64 and the worktable 16 includes the first negative pressure line 66 and the second negative pressure line 68. The first negative pressure line 66 is a negative pressure supply line for directly supplying the negative pressure (small suction amount) of the ejector 64 to the worktable 16. The second negative pressure line 68 is provided with a vacuum tank 80 and is a negative pressure supply line for supplying the negative pressure (large suction amount) of the vacuum tank 80 to the worktable 16. Therefore, a large exhaust speed for correcting the warped workpiece W to be flat and sucking it, and a small exhaust speed for sucking and holding the flattened warped workpiece W can be generated using one ejector 64. As a result, the initial cost and running cost of the workpiece suction device 60 can be reduced.

[0063] Furthermore, according to the workpiece suction device 60 of the embodiment, a configuration is adopted in which the second flow control valve 84 is provided upstream of the vacuum tank 80 (the branch section 70 side) in the second negative pressure line 68, so that the amount of air suction in the vacuum tank 80 by the ejector 64 can be throttled by the second flow control valve 84. This makes it possible to stably perform air suction in the vacuum tank 80 by the ejector 64, so that the vacuum tank 80 can be depressurized to a desired negative pressure state.

[0064] Modified examples of the workpiece suction device of the present invention will be described below. In the modified examples described below, the same reference numerals will be used to denote the same or similar members as those of the workpiece suction device 60 of the embodiment shown in Fig. 4. In the modified examples described below, the vacuum break line 86 (see Fig. 4) is omitted from the illustration.

[0065] Fig. 6 is a schematic diagram showing the configuration of a first modified example of the workpiece suction device. The workpiece suction device 100 of the first modified example shown in Fig. 6 is configured such that an upstream negative pressure supply line 76 for small exhaust with a small piping diameter connected to an ejector 64 is arranged via a rotary joint 17 that limits the exhaust speed, and a downstream negative pressure supply line 78 for large exhaust with a large piping diameter connected to a vacuum tank 80 is connected to a porous chuck 62 without passing through the rotary joint 17.

[0066] According to the workpiece suction device 100 of FIG. 6, the warped workpiece W can be sucked at a high exhaust speed of the vacuum tank 80 without being restricted by the rotary joint 17 that limits the exhaust speed.

[0067] Fig. 7 is a schematic diagram showing the configuration of a second modified example of the workpiece suction device. The workpiece suction device 110 of the second modified example shown in Fig. 7 adopts a configuration in which an ejector 112 is added in addition to the ejector 64, and the negative pressure generated by this ejector 112 is directly supplied to the vacuum tank 80. The ejector 64 and the ejector 112 are examples of the negative pressure generating unit of the present invention.

[0068] 7 has a first negative pressure line 166 and a second negative pressure line 168. The first negative pressure line 166 and the second negative pressure line 168 are examples of the first negative pressure line and the second negative pressure line, respectively, of the present invention.

[0069] 7, one end of a first negative pressure line 166 is connected to the ejector 64, and one end of a second negative pressure line 168 is connected to the ejector 112. The other ends of the first negative pressure line 166 and the second negative pressure line 168 are joined and connected to one end of a downstream negative pressure supply line 178, and the other end of the downstream negative pressure supply line 178 is connected to the porous chuck 62 of the work table 16. That is, the ejector 64 and the work table 16 (porous chuck 62) are communicated with each other via the first negative pressure line 166, and the ejector 112 and the work table 16 (porous chuck 62) are communicated with each other via the second negative pressure line 168.

[0070] The first negative pressure line 166 is provided with a first solenoid valve V1, similar to the first negative pressure line 66 in the above embodiment. On the other hand, the second negative pressure line 168 is provided with a third solenoid valve V3, a vacuum tank 80, a second solenoid valve V2, and a first flow control valve 82 in this order from the upstream side (the ejector 112 side) to the downstream side (the work table 16 side).

[0071] 7, a dedicated ejector 112 for supplying negative pressure to the vacuum tank 80 is provided in addition to the ejector 64, so that when the adsorption of the warped workpiece W by the negative pressure of the vacuum tank 80 is completed, the second solenoid valve V2 is closed and the third solenoid valve V3 is opened, thereby supplying negative pressure from the ejector 112 to the vacuum tank 80. This makes it unnecessary to carry out a preparation process after the warped workpiece W is carried out.

[0072] Fig. 8 is a schematic diagram showing the configuration of a third modified example of the workpiece adsorption device. The workpiece adsorption device 120 of the third modified example shown in Fig. 8 adopts a configuration in which the first negative pressure line 66 and the second negative pressure line 68 are directly connected to the porous chuck 62 without merging. Note that, in the workpiece adsorption device 110 of the second modified example shown in Fig. 7, the first negative pressure line 166 and the second negative pressure line 168 may be directly connected to the porous chuck 62 without merging, similar to the workpiece adsorption device 120 of the third modified example.

[0073] In the above embodiment and the first to third modified examples, an example has been described in which an ejector is used as a negative pressure source constituting the negative pressure generating unit of the present invention, but this is not limited to this, and for example, a mechanical or electric negative pressure pump can be applied.

[0074] In addition, in the above embodiment and the first to third modified examples, an example has been described in which the workpiece suction device of the present invention is applied to a dicing apparatus 10, but the workpiece suction device of the present invention can also be applied to, for example, a processing apparatus that cuts or grinds a workpiece, and a shape measuring apparatus that measures the shape of a workpiece.

[0075] An example of a workpiece suction device according to the present invention has been described above, but the technology of the present invention is not limited to the embodiment, and several improvements or modifications may be made without departing from the gist of the present invention. [Explanation of symbols]

[0076] 10... dicing device, 12... blade, 14... spindle, 16... work table, 17... rotary joint, 18... processing unit, 20... cleaning unit, 22... load port, 24... conveying device, 26... control unit, 28... X base, 30... X guide, 32... linear motor, 34... X table, 36... rotary table, 38... Y base, 40... Y guide, 42... Y table, 44... Z table, 50... system control unit, 52... processing control unit, 54... ejector control unit, 56... valve control unit, 58... computer readable medium, 60... work suction device, 62... porous chuck, 64... ejector , 66...first negative pressure line, 68...second negative pressure line, 70...branching section, 72...junction section, 74...negative pressure supply line, 76...upstream negative pressure supply line, 78...downstream negative pressure supply line, 80...vacuum tank, 82...flow control valve, 84...flow control valve, 86...vacuum break line, 88...flow control valve, 90...compressed air supply source, 100...workpiece suction device, 110...workpiece suction device, 112...ejector, 120...workpiece suction device, 166...first negative pressure line, 168...second negative pressure line, 178...downstream negative pressure supply line, V1...first solenoid valve, V2...second solenoid valve, V3...third solenoid valve, V4...fourth solenoid valve

Claims

1. A work table capable of adsorbing a workpiece; A negative pressure generating unit that generates a negative pressure for adsorbing the workpiece; a first negative pressure line communicating between the negative pressure generating unit and the work table; a second negative pressure line that is configured separately from the first negative pressure line and communicates between the negative pressure generating unit and the work table; a vacuum tank provided in the second negative pressure line; a negative pressure control unit that selectively switches between a first operation of supplying the negative pressure generated by the negative pressure generating unit to the work table and a second operation of supplying the negative pressure of the vacuum tank to the work table when the workpiece is adsorbed to the work table; Equipped with Workpiece suction device.

2. The negative pressure control unit temporarily performs the second operation and then performs only the first operation when the workpiece is adsorbed to the work table. The workpiece suction device according to claim 1 .

3. The negative pressure control unit starts the first operation before a timing at which the second operation is started. The workpiece suction device according to claim 1 or 2.

4. a first flow control valve provided in the second negative pressure line on the work table side relative to the vacuum tank; The workpiece suction device according to claim 1 or 2.

5. The negative pressure control unit supplies the negative pressure generated by the negative pressure generating unit to the vacuum tank when the second operation is stopped. The workpiece suction device according to claim 1 or 2.

6. a second flow control valve provided in the second negative pressure line closer to the negative pressure generating unit than the vacuum tank; The workpiece suction device according to claim 5.

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