Worktable, inspection device, and worktable operation method

Abstract

A table, an inspection device, and a method of operating the table, which can promote uniformization of a load applied to a base. The table has: a base; four movable bodies that support the base in a liftable manner; four drive motors that are provided corresponding to each of the four movable bodies to individually lift the four movable bodies; four guide portions that guide the lift of each of the four movable bodies; and a support frame that is continuous in a direction orthogonal to a lift direction of the base and has a wall surface parallel to the lift direction, and all of the four guide portions are fixed to the wall surface.

Description

Technical Field

[0001] This invention relates to a workbench, an inspection device, and a method for operating the workbench. Background Technology

[0002] Patent Document 1 discloses a worktable (inspection worktable) in an inspection apparatus for inspecting wafers, used to transport the object to be inspected to a predetermined position. The worktable supports a base (placement stage) for placing the wafer via three lifting drive mechanisms, and the base is raised and lowered while monitoring the lifting positions of the three lifting drive mechanisms.

[0003] The inspection apparatus brings numerous (tens of thousands) of contact probes into contact with the wafer during inspection. Therefore, a significant load is applied to the substrate from these numerous contact probes.

[0004] <Prior art documents>

[0005] <Patent Documents>

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-260852 Summary of the Invention

[0007] <Problem to be solved by this invention>

[0008] The present invention provides a technique that can appropriately adjust the posture of the base and promote the uniformity of the load applied to the base.

[0009] <Methods for solving problems>

[0010] According to one aspect of the present invention, a workbench is provided, comprising: a base; four movable bodies that support the base in a height-adjustable manner; four drive motors corresponding to each of the four movable bodies, thereby causing the four movable bodies to be individually raised and lowered; four guide portions that guide the raising and lowering of each of the four movable bodies; and a support frame that is continuous along a direction orthogonal to the raising and lowering direction of the base and has a wall surface parallel to the raising and lowering direction, and all four guide portions are fixed on the wall surface.

[0011] <The Effects of the Invention>

[0012] According to one method, the posture of the base can be properly adjusted, and the uniformity of the load applied to the base can be promoted. Attached Figure Description

[0013] Figure 1 This is a schematic cross-sectional view showing an inspection apparatus with a workbench according to one embodiment.

[0014] Figure 2This is a schematic side view showing the workbench of the inspection device.

[0015] Figure 3 This is a magnified 3D view showing the Z-axis movement mechanism of the worktable.

[0016] Figure 4 This is a perspective view showing the support frame of the Z-axis moving mechanism.

[0017] Figure 5 This is a schematic longitudinal sectional view showing the Z-axis moving mechanism.

[0018] Figure 6 This is a block diagram showing the drive motor, motor drive unit, and worktable control unit of the Z-axis movement mechanism.

[0019] Figure 7 This is a schematic diagram illustrating an example of the configuration of the lifting section of the Z-axis moving mechanism.

[0020] Figure 8 This is a flowchart illustrating the actions of the workbench during wafer inspection.

[0021] Figure 9 This is an illustrative diagram showing the movement of a stage-based base relative to the load on the contact probe.

[0022] Figure 10 (a) is a schematic diagram illustrating the calibration of the mounting surface based on the worktable. Figure 10 (b) is a schematic diagram illustrating the parallel calibration based on the worktable.

[0023] Figure 11 This is a schematic diagram illustrating a modified Z-axis movement mechanism.

[0024] Figure 12 (a) shows a schematic diagram of a magnetic gear motor applied to a modified drive motor. Figure 12 (b) is a schematic diagram showing the magnetic reduction mechanism between the drive motor and the Z-axis movable body applied to the modified example. Detailed Implementation

[0025] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same constituent parts, and sometimes repeated descriptions are omitted.

[0026] Figure 1 This is a schematic cross-sectional view showing an inspection device 1 having a workbench 30 in one embodiment. (See attached image.) Figure 1As shown, one embodiment of the inspection apparatus 1 is an apparatus for inspecting the electrical characteristics of each of a plurality of semiconductor devices (DUTs) formed on a wafer (substrate) W. It should be noted that the substrate having the DUTs is not limited to the wafer W, but also includes carriers, glass substrates, chip units, etc., on which the semiconductor devices are disposed. The inspection apparatus 1 includes a receiving chamber 12 for accommodating a worktable 30, a loader 13 disposed adjacent to the receiving chamber 12, and a tester 20 disposed above the receiving chamber 12.

[0027] The interior of the housing 12 has a hollow shell shape. Inside the housing 12 is a stage 30 for mounting the wafer W, a probe card 15 arranged opposite to the stage 30, and an inspection-side camera 29 for capturing images of the wafer W on the stage 30. The probe card 15 has a plurality of needle-shaped probes (contact terminals) 16 arranged corresponding to the electrode pads and solder bumps of the electrodes of the semiconductor devices on the wafer W. The inspection-side camera 29 captures images of the tilt of the stage 30 and the position of the wafer W mounted on the stage 30.

[0028] Loader 13 removes wafer W from FOUP (not shown), which serves as a transport container, and places it on worktable 30 inside receiving chamber 12. Additionally, loader 13 removes inspected wafer W from worktable 30 and places it in FOUP.

[0029] The probe card 15 is connected to the tester 20 via interface 17. Each probe 16 contacts the electrode pads and solder bumps of the electrodes of the semiconductor devices located on the wafer W. Thus, each probe 16 can supply power from the tester 20 to the semiconductor devices via interface 17, or transmit signals from the semiconductor devices to the tester 20 via interface 17.

[0030] The tester 20 has a test board (not shown) that reproduces a portion of the circuit configuration of a motherboard equipped with a semiconductor device. The test board is connected to a controller 90 for control, which determines the quality of the semiconductor device based on signals from the semiconductor device. The tester 20 can reproduce the circuit configuration of various motherboards by changing the test board.

[0031] The worktable 30 transports the wafer W between the loader 13 and a position opposite the probe card 15. Furthermore, the worktable 30 raises the wafer W toward the probe card 15 during inspection and lowers it after inspection. A worktable-side camera 19 is also mounted on the worktable 30 to confirm the position of the probe card 15.

[0032] Figure 2 This is a schematic side view showing the worktable 30 of the inspection device 1. (See attached image.) Figure 2As shown, the inspection device 1 has a frame structure 31 for supporting the worktable 30. The worktable 30, provided on the frame structure 31, transports the wafer W to a suitable three-dimensional position (X-axis, Y-axis, and Z-axis) within the receiving chamber 12. The worktable 30 has a moving part 32 (X-axis moving mechanism 33, Y-axis moving mechanism 34, Z-axis moving mechanism 40), a base 35, a needle polishing mechanism 60, a worktable control part 70, and a motor drive part 80.

[0033] The frame structure 31 presents a two-level structure including an upper base 310 for supporting the moving part 32, a lower base 311 for supporting the worktable control part 70 and the motor drive part 80, and a plurality of support columns 312 provided at the four corners of the upper base 310 and the lower base 311.

[0034] The X-axis movement mechanism 33 of the moving part 32 includes a plurality of guide rails 330 fixed to the upper surface of the upper base 310 and extending along the X-axis direction, and X-axis movable bodies 331 arranged between the guide rails 330. The X-axis movable body 331 has an X-axis actuating part (motor, gear mechanism, etc., not shown) inside, which is connected to the motor drive unit 80. Thus, the X-axis movable body 331 reciprocates in the X-axis direction based on the power supply from the motor drive unit 80.

[0035] Similarly, the Y-axis moving mechanism 34 includes multiple guide rails 340 fixed to the upper surface of the X-axis movable body 331 and extending along the Y-axis direction, and Y-axis movable bodies 341 arranged between the guide rails 340. A horizontal moving stage 342, which is rectangular when viewed from above, is provided on the Y-axis movable body 341. The Y-axis movable body 341 also has a Y-axis actuating part (electric motor, gear mechanism, etc., not shown) internally, which is connected to the electric motor drive unit 80. Thus, the Y-axis movable body 341 moves back and forth in the Y-axis direction based on a power supply from the electric motor drive unit 80.

[0036] Z-axis movement mechanism 40 is provided on horizontal moving stage 342 (Y-axis movable body 341), and base 35 is held on its upper part. Z-axis movement mechanism 40 constitutes a lifting mechanism of this embodiment for lifting the wafer W placed on base 35 by displacing base 35 in the Z-axis direction (vertical direction). The configuration of this Z-axis movement mechanism 40 will be described in detail later.

[0037] The base 35, which is transported by the moving part 32, functions as a chuck to hold the wafer W on its upper surface by a suitable holding device (vacuum suction, mechanical chuck, etc.). The base 35 has a base plate 350 that engages with the Z-axis moving mechanism 40, and a chuck top 351 stacked on the upper side of the base plate 350.

[0038] The base plate 350 is formed into a suitable top-view shape (generally polygonal) that can engage with the Z-axis movement mechanism 40. The chuck top 351 is formed into a circle when viewed from above and has a thickness greater than that of the base plate 350. The upper surface of the chuck top 351 becomes the mounting surface 35a for mounting the wafer W. In addition, the base 35 may be configured to include a temperature control mechanism for adjusting the temperature of the mounting surface 35a, a temperature sensor for detecting the temperature of the mounting surface 35a, and a suction mechanism for vacuum adsorption of the wafer W mounted on the mounting surface 35a, etc. (all not shown).

[0039] The needle grinding mechanism 60 of the worktable 30 is disposed adjacent to the Z-axis moving mechanism 40 in the horizontal moving stage 342. A grinding body 61 for grinding the probe 16 protruding downward from the probe holder 15 is provided on the upper part of the needle grinding mechanism 60. The needle grinding mechanism 60 has a grinding-side Z-axis moving mechanism 62 for displacing the grinding body 61 in the Z-axis direction. The grinding-side Z-axis moving mechanism 62 is configured substantially the same as the Z-axis moving mechanism 40 of the base 35.

[0040] The workbench control unit 70 is connected to the controller 90 of the inspection device 1, and controls the operation of the workbench 30 based on the instructions of the controller 90. The workbench control unit 70 may include, for example, a main control unit for controlling the overall operation of the workbench 30, a PLC for controlling the operation of the moving part 32, a temperature controller for controlling the temperature control mechanism, a lighting control unit, and a power supply unit (all not shown). The main control unit of the workbench control unit 70 may utilize a desktop computer's built-in board having one or more processors (not shown), memory, input / output interfaces, and electronic circuits. The one or more processors combine one or more of the following: CPU, ASIC, FPGA, circuits composed of multiple discrete semiconductors, etc., to execute programs and schemes stored in the memory. The memory includes non-volatile memory and volatile memory, which form the storage unit of the workbench control unit 70.

[0041] The worktable control unit 70 receives the wafer W from the loader 13 onto the base 35 of the worktable 30, and moves the moving part 32 horizontally (X-axis to Y-axis direction) to align the wafer W with the probe card 15 of the designated tester 20. After alignment, the worktable control unit 70 raises the base 35 via the worktable 30, bringing the wafer W into contact with the probes 16 of the probe card 15. In this state, the controller 90 of the inspection device 1 begins the electrical inspection performed by the tester 20. After the inspection by the tester 20 is completed, the worktable control unit 70 performs the opposite action, lowering and horizontally moving the inspected wafer W back to the loader 13.

[0042] Figure 3This is a magnified perspective view of the Z-axis moving mechanism 40 of the worktable 30. (See image below.) Figure 3 As shown, the Z-axis moving mechanism 40 has a support frame 41 provided on the horizontal moving stage 342. The support frame 41 is a continuous component in a direction orthogonal to the lifting direction of the base 35 (horizontal direction: X-axis-Y-axis direction). Here, "continuous in a direction orthogonal to the lifting direction" means that the support frame 41 is continuous without separation, thus presenting a predetermined shape when viewed from above. The support frame 41 protects the four lifting parts 45 of the Z-axis moving mechanism 40 and guides the lifting of each lifting part 45. That is, the Z-axis moving mechanism 40 is configured to move the aforementioned base 35 (chuck: also refer to) via the four lifting parts 45. Figure 1 It consists of components that allow for lifting and lowering.

[0043] Each lifting unit 45 includes a Z-axis movable body 46 that directly supports the base 35, a drive motor 47 that raises and lowers the Z-axis movable body 46, and a guide part 48 that guides the raising and lowering of the Z-axis movable body 46. That is, the Z-axis moving mechanism 40 is configured to include a support frame 41, four Z-axis movable bodies 46, four drive motors 47, and four guide parts 48.

[0044] Figure 4 This is a perspective view showing the support frame 41 of the Z-axis moving mechanism 40. (See diagram below.) Figure 4 As shown, the support frame 41 has a pair of sidewalls 42 and a connecting wall 43 extending between the pair of sidewalls 42, forming an H-shape when viewed from above. The upper surfaces of the pair of sidewalls 42 and the upper surface of the connecting wall 43 are connected to form a single surface, and the upper part of the support frame 41 is flat. For the lower part of the support frame 41, the lower portion of the connecting wall 43 protrudes in a stepped manner relative to the lower surfaces of the pair of sidewalls 42. With the support frame 41 fixed to the horizontal moving stage 342, the connecting wall 43 is inserted into a hole 342a (see reference) formed in the horizontal moving stage 342 (Y-axis movable body 341). Figure 5 ), which protrudes downwards from the Y-axis movable body 341.

[0045] A pair of sidewalls 42 are fixed to the upper surface of the horizontal moving stage 342. Each sidewall 42, when viewed from the side, is approximately rectangular, extending longer in the X-axis direction and shorter in the Z-axis direction. A connecting wall 43 is attached to the middle of the X-axis (long side) of each sidewall 42. Furthermore, the length of each sidewall 42 in the Z-axis direction is set to be shorter than the lifting distance of the base 35. Multiple threaded fastening spaces 420 are formed at predetermined positions on the lower surface of the pair of sidewalls 42. Fixing screws 421, passing through these threaded fastening spaces 420 and through each sidewall 42, are threaded onto the horizontal moving stage 342, thereby securely fixing the support frame 41 to the horizontal moving stage 342 (see also...). Figure 3 ).

[0046] The connecting wall 43 is formed as a generally rectangular shape extending in the Y-axis direction (width direction) and the Z-axis direction (height direction, vertical direction). The length of the connecting wall 43 in the Y-axis direction is longer than the length of the side wall 42 in the X-axis direction. In addition, the support frame 41 is sufficiently (for example, about twice) longer in the Z-axis direction than the length of the side wall 42, thereby forming a shape in which the lower side of the connecting wall 43 extends downward than the pair of side walls 42.

[0047] Four guide portions 48 of the lifting parts 45 are fixed to the wall surfaces 43a and 43b of the connecting wall 43, respectively. Each guide portion 48 has a pair of tracks 49 extending in the Z-axis direction. The pair of tracks 49 extend in a straight line from the upper end to the lower end of the connecting wall 43 and are firmly fixed by means of threaded fastening or the like. In addition, the guide portions 48 have movement limiting blocks 50 between the pair of tracks 49 and on the upper part of the wall surfaces 43a and 43b of the connecting wall 43 to limit the upward movement of the Z-axis movable body 46.

[0048] Furthermore, the Z-axis moving mechanism 40 has two guide portions 48 (a pair of tracks 49 and a movement limiting block 50) on one wall surface 43a in the X-axis direction of the connecting wall 43, and two guide portions 48 on another wall surface 43b in the X-axis direction of the connecting wall 43. The two guide portions 48 on each of the two wall surfaces 43a and 43b are arranged in the Y-axis direction, so that the four tracks 49 extend parallel to each other along the Z-axis direction on one wall surface 43a and the other wall surface 43b.

[0049] return Figure 3 The drive motor 47 of the lifting unit 45 is fixed to the horizontal moving stage 342 and has a shaft portion 470 protruding in the positive Z-axis direction. The type of drive motor 47 is not particularly limited; to achieve miniaturization of the Z-axis moving mechanism 40, a direct drive motor can be used, for example. Direct drive motors do not include a reduction gear and are configured to be lower relative to the axial direction of the shaft portion 470, and are capable of rotating at low speed and high torque.

[0050] Between the drive motor 47 and the Z-axis movable body 46, a power conversion unit 51 is provided to convert the rotational motion of the drive motor 47 into the linear motion of the Z-axis movable body 46. For example, the power conversion unit 51 can be constructed such that a ball screw 53 is threaded into a nut 52 connected to the rotor (not shown) of the drive motor 47. The ball screw 53 is coaxial with the shaft portion 470 of the drive motor 47, is splined at an appropriate position within the drive motor 47, and the Z-axis movable body 46 is fixed at its upper end. Through the power conversion unit 51, the lifting unit 45 causes the ball screw 53 (shaft portion 470) to reciprocate along the Z-axis direction under the rotation of the nut 52, thereby causing the Z-axis movable body 46 to rise and fall with the ball screw 53.

[0051] Furthermore, the drive motor 47 includes an encoder 54 for detecting the rotation angle of the rotor, and a torque sensor 55 for detecting the load value applied to the rotor from the base 35 as torque (current value) (see reference). Figure 6 ).

[0052] The Z-axis movable part 46 of the lifting part 45 is a component for supporting the base 35. It is raised and lowered based on the drive of the drive motor 47, thereby raising and lowering the base 35. The Z-axis movement mechanism 40 of this embodiment raises and lowers each of the four Z-axis movable parts 46 (lifting part 45) individually, thereby adjusting the tilt of the base 35.

[0053] Figure 5 This is a schematic longitudinal sectional view of the Z-axis moving mechanism 40. (See attached image.) Figure 5 As shown, the Z-axis movable body 46 has a horizontal extension 460 that is parallel in the horizontal direction (X-Y direction) and a vertical extension 461 that is connected to the horizontal extension 460 and parallel in the vertical direction, which is formed in a roughly L-shape in side section view.

[0054] The lateral extension 460 is roughly polygonal when viewed from above, and a ball screw 53 (shaft 470) is connected to it at a position on the outer side of the X-axis (away from the connecting wall 43) from the center of the X-axis direction. The Z-axis movable body 46 moves up and down in the vertical direction based on the linear motion of the ball screw 53 in the Z-axis direction.

[0055] The longitudinal extension 461 is provided at a position adjacent to the connecting wall 43 of the support frame 41, opposite to the connecting wall 43. The longitudinal extension 461 is formed into a rectangular shape that extends shorter in the Y-axis direction and longer in the Z-axis direction. In the longitudinal extension 461, on the opposing surface opposite to the connecting wall 43 of the support frame 41, a pair of sliding members 56 are provided for arranging a pair of tracks 49. The sliding members 56 are engaged with the tracks 49, thereby guiding movement in the Z-axis direction (the extension direction of the tracks 49). Through the tracks 49 and the sliding members 56, disengagement of the Z-axis movable body 46 in the horizontal direction (X-axis-Y-axis direction) is prevented, and movement in the Z-axis direction is guided.

[0056] In addition, such as Figure 3As shown, the Z-axis movable body 46 has a contact member 57 fixed to the upper surface of the transverse extension 460, which contacts the base plate 350 of the base 35. That is, the base 35 is supported by four contact members 57. The contact member 57 is formed as a rigid block with a flat upper surface. It should be noted that the Z-axis movement mechanism 40 can use a load sensor such as a force sensor instead of the contact member 57. Thus, for example, the table control unit 70 can use the load detected by the load sensor to further identify the tilt state of the base 35 with high precision.

[0057] Figure 6 This is a block diagram showing the drive motor 47, motor drive unit 80, and table control unit 70 of the Z-axis movement mechanism 40. Figure 6 As shown, inside the worktable control unit 70, a Z-axis controller 71 for driving each of the four drive motors 47 is provided. Furthermore, inside the motor drive unit 80, a servo amplifier 81 for controlling the current supplied to the drive motor 47 is provided based on the target position of each Z-axis controller 71. It should be noted that the servo amplifier 81 can be integrated with the drive motor 47.

[0058] The Z-axis controller 71 uses a PLC or similar device. For each control cycle, it receives position commands related to the lifting position of the base 35 from the main control unit of the worktable control unit 70, thereby calculating the target position of the drive motor 47. The PLC has a processor (or integrated circuit). The Z-axis controller 71 includes a target position output unit 72 that outputs the calculated target position to a servo amplifier 81. The servo amplifier 81 adjusts the power supplied to the drive motor 47 based on the target position received from the target position output unit 72.

[0059] Additionally, the rotor rotation angle detected by the encoder 54 located on the drive motor 47 is fed back to the position controller 82 of the servo amplifier 81. The servo amplifier 81 calculates the difference between the actual position and the target position within the position controller 82, and adjusts the power supplied to the drive motor 47 according to the difference.

[0060] On the other hand, the torque detected by the torque sensor 55 is sent to the stage control unit 70. The torque of the torque sensor 55 is equivalent to the load value distributed by the loads applied to the wafer W and the base 35 by the multiple probes 16 through the lifting units 45. Furthermore, the stage control unit 70 has a correction calculation unit 73 that calculates the correction amount (tilt correction amount) relative to the target position based on the torque received from the torque sensor 55.

[0061] The correction calculation unit 73 calculates the tilt correction amount for correcting the target position of the four drive motors 47 based on the torques detected by the four torque sensors 55. For example, the correction calculation unit 73 extracts the load position of the multiple probes 16 applied to the base 35 from the torques of the four torque sensors 55, further estimates the overall tilt state of the base 35 based on the load position, and obtains each tilt correction amount based on the tilt state.

[0062] The preferred load positions are pre-defined at several tens to hundreds of points on the substrate 35, and the torques applied to each drive motor 47 when multiple probes 16 contact the wafer W are databased. Therefore, the correction calculation unit 73 can identify the load positions based on the four obtained torques. Furthermore, for example, the correction calculation unit 73 maintains load-tilt characteristic mapping information MI or a function representing the relationship between the load positions and the tilt state of the substrate 35, thereby estimating the overall tilt state of the substrate 35 based on the identified load positions. The tilt state is indicated by the position of the substrate 35 in the X-Y axis direction of tilt, the magnitude of tilt (tilt amount), etc.

[0063] The correction calculation unit 73 sets the tilt correction amount for each drive motor 47 to level the mounting surface 35a of the base 35 based on the estimated overall tilt state of the base 35. The tilt correction amount can be calculated using a predetermined formula or data that records the tilt correction amount for each drive motor 47 corresponding to the tilt state. Therefore, for example, if the torque of one drive motor 47 is relatively large compared to the torques of the other drive motors 47, it indicates that the load of the probe 16 is applied more to one drive motor 47. Thus, the correction calculation unit 73 sets the tilt correction amount of the drive motor 47 with the relatively large applied torque to be larger than the tilt correction amounts of the other drive motors 47.

[0064] If the four Z-axis controllers 71 receive the tilt correction amounts calculated by the correction amount calculation unit 73, they calculate the target position for correction by adding the tilt correction amounts to the position command with the same timing as the received values. The target position output unit 72 outputs the target position for correction to the servo amplifier 81. Thus, even if the base 35 is tilted due to the load of the probe 16, the Z-axis movement mechanism 40 can properly raise and lower each of the four lifting units 45 (drive motors 47) to level the base 35.

[0065] return Figure 2The needle grinding mechanism 60, located adjacent to the worktable 30, also has a grinding-side Z-axis moving mechanism 62 with the same structure as the worktable 30. Specifically, the grinding-side Z-axis moving mechanism 62 includes a grinding-side support frame 63 and four grinding-side lifting sections 64 supported by the grinding-side support frame 63 and used to raise and lower the grinding body 61. The grinding-side support frame 63, like the support frame 41, has a pair of side walls and a connecting wall (not shown), forming an H-shape when viewed from above. Furthermore, each grinding-side lifting section 64, like the lifting section 45, has a grinding-side drive motor 65, a grinding-side power conversion section 66, a grinding-side Z-axis movable body 67, and a grinding-side guide section 68.

[0066] When the grinding body 61 contacts the probe 16, the Z-axis moving mechanism 62 on the grinding side can also correct the tilt of the grinding body 61 through the four grinding side lifting parts 64. In other words, the needle grinding mechanism 60 also has the function of properly adjusting the posture of the grinding body 61 (equivalent to the base 35 of the present invention) that bears the load. That is to say, during the grinding of the probe 16, the needle grinding mechanism 60 can uniformly grind the probe 16 by keeping the grinding body 61 horizontal.

[0067] The workbench 30 and the inspection device 1 of this embodiment are basically configured as described above, and their functions will be explained below.

[0068] First, refer to Figure 7 The significance of the four lifting parts 45 in the Z-axis moving mechanism 40 will be explained. Figure 7 This is a schematic explanatory diagram showing an example of the configuration of the shaft portion 470 (lifting portion 45) of the drive motor 47 of the Z-axis movement mechanism 40. (a) shows the Z-axis movement mechanism 40 of this embodiment, and (b) shows the Z-axis movement mechanism 100 of the reference example. It should be noted that in... Figure 7 In the middle, although the wire connecting the four drive motors 47 or the three drive motors 47 is external to the base 35, the wire can be located inside the base 35.

[0069] like Figure 7 As shown in (b), the Z-axis movement mechanism 100 of the reference example raises and lowers the base 35 via three drive motors 47. In this case, the three drive motors 47 are positioned at a distance from the base 35 to stabilize its posture and maintain its balance. That is, in the Z-axis movement mechanism 100 that supports the base 35 via three drive motors 47, the top view dimension of the worktable 30 becomes larger.

[0070] In contrast, such as Figure 7As shown in (a), the Z-axis movement mechanism 40 of this embodiment raises and lowers the base 35 via four drive motors 47. Compared to the Z-axis movement mechanism 100 of the reference example, this Z-axis movement mechanism 40 can arrange four drive motors 47 near the base 35. In other words, the Z-axis movement mechanism 40 can reduce the top-view size of the worktable 30 and stabilize and balance the base 35 via four drive motors 47.

[0071] Figure 8 This is a flowchart showing the operation of the worktable 30 during the inspection of wafer W. Figure 9 This is an explanatory diagram showing the movement of the base 35 based on the stage 30 relative to the load of the probe 16. (a) shows the case of center misalignment of the load of the probe 16, and (b) shows the adjustment of the posture of the base 35.

[0072] During the inspection of wafer W, the inspection device 1, based on the control of the controller 90, places wafer W on the mounting surface 35a of the stage 35 of the worktable 30. If wafer W is placed on the stage 35, the worktable control unit 70 receives a movement instruction from the controller 90. Thus, as... Figure 8 As shown, the stage control unit 70 controls the moving unit 32 to transport the wafer W in the horizontal direction (X-Y axis direction) (step S1). Through this horizontal transport, the stage 30 positions the wafer W below the tester 20.

[0073] Subsequently, the table control unit 70 outputs the target position of the drive motor 47 from the controller 71 of each Z-axis to the servo amplifier 81 (step S2). As a result, appropriate power is supplied from each servo amplifier 81 to each drive motor 47, causing each drive motor 47 to rise vertically upwards. Each Z-axis movable body 46 is guided by its guide portion 48, which is fixed to the support frame 41, which is continuous in a direction orthogonal to the lifting direction, during the rise of the drive motor 47. Therefore, each Z-axis movable body 46 moves smoothly in the vertical direction, allowing the base 35 to rise without wobbling. Furthermore, the table control unit 70 raises each Z-axis movable body 46 at the same lifting speed until the base 35 contacts the probe 16 of the probe holder 15. Therefore, the table 30 can reliably maintain the level of the mounting surface 35a of the base 35.

[0074] As the base 35 rises, the probes 16 supported by the tester 20 come into contact with the wafer W. At this time, as... Figure 9 As shown in (a), if the center of gravity of the load of each probe 16 is misaligned from the center of the base 35, a tilt (inclination) is produced in the base 35. As an example, when a load of about 500 kg is applied from each probe 16 near the outer periphery of the base 35, the base 35 tilts in μm units.

[0075] Therefore, the worktable control unit 70 independently controls the four lifting parts 45 of the Z-axis moving mechanism 40 to level the mounting surface 35a by correcting the tilt state of the base 35. Specifically, when the base 35 rises, the worktable control unit 70 obtains the torque (load value) from each torque sensor 55 (step S3).

[0076] Furthermore, the stage control unit 70 acquires the real-time torques at any point when the probe 16 contacts the wafer W, and the correction calculation unit 73 calculates the tilt correction amount for each of the four lifting units 45 (step S4). As described above, the correction calculation unit 73 extracts the load position of each probe 16 based on each torque, further estimates the overall tilt state of the base 35 based on the load position, and calculates each tilt correction amount based on the tilt state. Each tilt correction amount is a value that enables high-precision correction of the tilt state of the base 35 in three-dimensional coordinates.

[0077] The controllers 71 of each Z-axis in the worktable control unit 70 add the tilt correction amount sent by the self-correction calculation unit 73 to the position command, and output the corrected target position to each servo amplifier 81 (step S5). As a result, each servo amplifier 81 supplies power corresponding to the corrected target position to each drive motor 47, and each drive motor 47 rotates independently, causing the Z-axis movable body 46 to rise and fall. For example, as... Figure 9 As shown in (b), for the worktable 30, one or two Z-axis movable bodies 46 near the location where the probe 16 applies a load on the base 35 are slightly raised compared to the Z-axis movable bodies 46 at other locations. As a result, the worktable 30 corrects the tilt of the mounting surface 35a of the base 35, making the mounting surface 35a horizontal.

[0078] The mounting surface 35a is kept horizontal by the stage 30, thereby suppressing uneven load on each probe 16 and stabilizing the contact resistance of each probe 16. Therefore, the stage control unit 70 sends information indicating that the tilt correction of the stage 35 is complete to the controller 90 of the inspection apparatus 1 (step S6) in order to start the electrical inspection of the wafer W. Based on this information, the controller 90 starts the inspection of the wafer W that has been moved to the stage 30. It should be noted that the controller 90 can receive image information from the inspection-side camera 29 to identify that the mounting surface 35a is horizontal, thereby starting the inspection. As a result, the inspection apparatus 1 can inspect the wafer W with high precision, thereby improving the yield rate during the inspection of the wafer W.

[0079] Furthermore, the Z-axis movement mechanism 40, which has four lifting sections 45, is not limited to adjusting the tilt of the base 35, but can perform various controls during inspection. See below for reference. Figure 10 Other controls for the Z-axis movement mechanism 40 will be explained. Figure 10(a) is a schematic diagram illustrating the alignment of the mounting surface performed via the worktable 30. Figure 10 (b) is a schematic diagram illustrating the parallel calibration performed via the worktable 30.

[0080] like Figure 10 As shown in (a), for example, the base 35 may sometimes warp or deform due to temperature, causing the mounting surface 35a to become concave or convex, thereby reducing the flatness of the mounting surface 35a. Therefore, the worktable 30 can use the Z-axis movement mechanism 40 to perform mounting surface correction. During mounting surface correction, the worktable control unit 70 detects the warping of the mounting surface 35a based on the image information of the mounting surface 35a captured by the inspection side camera 29, and then independently adjusts the lifting of the four lifting units 45 according to the warping of the mounting surface 35a. Therefore, even when the mounting surface 35a is warped, the mounting surface 35a at the contact points of the multiple probes 16 can be leveled, thereby stabilizing the contact resistance of each probe 16.

[0081] In addition, such as Figure 10 As shown in (b), when the probe card 15 is tilted, the worktable 30 can perform parallel correction to tilt the mounting surface 35a of the base 35 in a manner consistent with the tilt of the probe card 15. For example, in parallel correction, the worktable 30 calculates the tilt state (tilt direction, tilt amount) of the probe card 15 based on image information of the probe card 15 captured by the worktable-side camera 19, and independently adjusts the lifting of the four lifting parts 45 according to the tilt state. Thus, even when the probe card 15 is tilted, the mounting surface 35a can be made parallel to the plurality of probes 16, thereby stabilizing the contact resistance of each probe 16.

[0082] Furthermore, the workbench 30 is not limited to the above-described embodiments and can be adapted to various variations. Figure 11 The following are schematic diagrams illustrating modified Z-axis moving mechanisms 40A and 40B: (a) shows Z-axis moving mechanism 40A with a square support frame 41A, and (b) shows Z-axis moving mechanism 40B with a cross-shaped support frame 41B.

[0083] like Figure 11 As shown in (a), the Z-axis movement mechanism 40A can be configured as a rectangular (square ring-shaped) support frame 41A when viewed from above, with guide portions 48 of four lifting parts 45 fixed to the inner walls 43c and 43d of the support frame 41A. For example, two guide portions 48 are provided on each pair of short sides of the support frame 41, thereby guiding the displacement of the Z-axis movable body 46 disposed inside. In this case, the support frame 41 can correct the tilt of the base 35 by stably raising and lowering each lifting part 45.

[0084] In addition, such as Figure 11 As shown in (b), the Z-axis moving mechanism 40B can be configured as a cross-shaped support frame 41B when viewed from above, with guide portions 48 of four lifting parts 45 fixed to the walls 43e, 43f, 43g, and 43h of the support frame 41. In this case, the support frame 41 can also firmly fix the guide portions 48, allowing each lifting part 45 to move up and down stably. It should be noted that, as Figure 11 As shown in (b), the guide portion 48 of each lifting part 45 can have multiple tracks 49 on different wall surfaces 43e, 43f, 43g, 43h (this configuration can also be applied to other Z-axis moving mechanisms 40, 40A).

[0085] in addition, Figure 12 This is a schematic diagram illustrating the lifting parts 45A and 45B of the modified example. (a) shows the magnetic gear motor 58A used in the drive motor 47, and (b) shows the magnetic reduction mechanism 58B used between the drive motor 47 and the Z-axis movable body 46. Figure 12 As shown, the worktable 30 may have a magnetic deceleration unit 58 between the four drive motors 47 themselves or between the four Z-axis movable bodies 46 and the four drive motors 47, which decelerates the rotational motion of the drive motors 47 by magnetic force.

[0086] For example, as a magnetic deceleration unit 58, such as Figure 12 As shown in (a), a configuration of a magnetic gear motor 58A with magnetic reduction function applied as a drive motor 47 can be cited. As an example, the magnetic gear motor 58A has a stator 581 and a high-speed rotor 582 and a low-speed rotor 583 coaxial with the stator 581. The stator 581 is located on the outer periphery side of the magnetic gear motor 58A, with multiple coils arranged in a ring around the periphery. Under the control of the Z-axis controller 71, three-phase AC power is supplied to each coil from the motor drive unit 80. The high-speed rotor 582 is located on the center side of the magnetic gear motor 58A, with multiple magnetic poles (N pole, S pole) arranged in a ring around the periphery on its outer periphery. The low-speed rotor 583 is a ring-shaped component disposed between the stator 581 and the high-speed rotor 582, with multiple magnetic pole pieces arranged in a ring around the periphery. Furthermore, the low-speed rotor 583 and the power conversion unit 51 (see reference) that converts the rotation of the low-speed rotor 583 into linear motion of the Z-axis movable body 46... Figure 3 )link.

[0087] The magnetic gear motor 58A configured as described above is based on the motor drive unit 80 (see reference). Figure 2The three-phase AC power from the magnetic gear motor 58A rotates the high-speed rotor 582 on the inner side. Correspondingly, the low-speed rotor 583, located on the outer side of the high-speed rotor 582, rotates at a low speed and high torque. The reduction ratio of the magnetic gear motor 58A can be set by the ratio of the number of magnetic poles in the high-speed rotor 582 to the number of magnetic pole pieces in the low-speed rotor 583. By applying the magnetic gear motor 58A to the lifting unit 45A in this way, the power consumption when raising and lowering the Z-axis movable body 46 can be significantly reduced. Furthermore, by miniaturizing the magnetic gear motor 58A and increasing its torque, the footprint of the magnetic gear motor 58A can be minimized. Moreover, since the magnetic gear motor 58A allows the high-speed rotor 582 and the low-speed rotor 583 to transmit torque without contact, vibration is reduced, and the contact performance of the wafer W can be improved during the movement of the worktable 30. As a result, an increase in yield during testing can be expected.

[0088] Or, such as Figure 12 As shown in (b), the magnetic reduction unit 58 may be configured such that each drive motor 47 and each Z-axis movable body 46 (power conversion unit 51) has a magnetic reduction mechanism 58B. The magnetic reduction mechanism 58B, for example, includes a stator 586 with multiple magnetic pole pieces arranged in a ring, a high-speed rotor 587 with multiple magnetic poles arranged in a ring inside the stator 586, and a low-speed rotor 588 with multiple magnetic poles arranged in a ring outside the stator 586. In this case, the stator 586 is fixed, and the shaft 470 of the drive motor 47 is connected to the high-speed rotor 587. The high-speed rotor 587 rotates in response to the rotation of the drive motor 47. The rotation of the magnetic poles of the high-speed rotor 587 is transmitted through the multiple magnetic pole pieces of the stator 586, thereby causing the low-speed rotor 588 to rotate relative to the high-speed rotor 587 in a reduced-speed state. Therefore, similar to the magnetic gear motor 58A, the lifting part 45B with the magnetic reduction mechanism 58B can also achieve the effects of reduced power consumption, miniaturization, weight reduction, and vibration reduction.

[0089] The technical concept and effects of the present invention described in the above embodiments are described below.

[0090] The first aspect of the present invention is a worktable 30, which includes: a base 35 for holding a transported object (wafer W); four movable bodies (Z-axis movable bodies 46) that support the base 35 in a height-adjustable manner; four drive motors 47 that are correspondingly provided with each of the four movable bodies and cause the four movable bodies to be raised and lowered individually; four guides 48 that guide the raising and lowering of each of the four movable bodies; and a support frame 41, 41A, 41B that is continuous along a direction orthogonal to the raising and lowering direction of the base 35 and has walls 43a to 43h parallel to the raising and lowering direction, and all four guides 48 are fixed on the walls 43a to 43h.

[0091] As described above, the worktable 30 allows each of the four movable bodies (Z-axis movable body 46) to be raised and lowered individually, thereby enabling proper adjustment of the posture of the base 35. In particular, the worktable 30 uses continuous support frames 41, 41A, and 41B in a plane orthogonal to the lifting direction to fix the four guide portions 48, allowing each movable body to rise and fall smoothly and promoting uniformity of the load applied to the base 35. Furthermore, the four movable bodies, four drive motors 47, and four guide portions 48 minimize the top-view dimensions of the worktable 30.

[0092] Furthermore, the system includes a control unit (worktable control unit 70) that sets the target position for each of the four drive motors 47 during the lifting and lowering of the base 35 and controls the operation of the four drive motors 47 based on the target position; and four torque sensors 55, each located on one of the four drive motors 47, that detect the torque of the drive motor 47. The control unit corrects the target position of each of the four drive motors 47 based on the torque fed back from each of the four torque sensors 55. As a result, the worktable 30 can lift and lower the four movable bodies with high precision based on the load applied to the base 35.

[0093] Furthermore, the control unit (table control unit 70) identifies the tilt state of the base 35 based on the torque of the four torque sensors 55, and calculates a correction value for the target position of each of the four drive motors 47 according to the tilt state of the base 35. Thus, the table 30 can further control the four drive motors 47 with high precision; for example, even if the base 35 is tilted from horizontal, it can quickly return the base 35 to horizontal.

[0094] Furthermore, the support frame 41, having a pair of side walls 42 in a direction orthogonal to the lifting direction and a connecting wall 43 connecting the pair of side walls 42, is H-shaped when viewed from above. Four movable bodies (Z-axis movable body 46), four drive motors 47, and four guide parts 48 are arranged between the pair of side walls 42. Thus, the worktable 30 stably supports the four guide parts 48 through the support frame 41, thereby enabling smooth lifting and lowering of the movable bodies.

[0095] Furthermore, the support frame 41 has two of the four guide portions 48 fixed on one wall surface 43a of the connecting wall 43, and the remaining two of the four guide portions 48 fixed on the other wall surface 43b of the connecting wall 43. Thus, the worktable 30 is arranged with two movable bodies (Z-axis movable body 46) arranged along the extension direction of the connecting wall 43, which allows for a smaller top view dimension.

[0096] In addition, each of the four movable bodies (Z-axis movable body 46) has a lateral extension 460 connected to each of the four drive motors 47, and a longitudinal extension 461 extending orthogonally to the extension direction of the lateral extension 460 and guided by each of the four guides 48. As a result, the contact area between the four movable bodies and the guides 48 is lengthened, which can further stabilize the body as it moves up and down along the guides 48.

[0097] Furthermore, the support frames 41, 41A, 41B and the four guide sections 48 extend along the lifting direction in a manner longer than the positions of the four drive motors 47. As a result, the worktable 30 can increase the lifting distance of the movable body (Z-axis movable body 46) and can also make the movable body lift and lower stably.

[0098] In addition, the four drive motors 47 are direct drive motors. As a result, the height of the drive motors 47 in the worktable 30 can be set to be relatively small, and miniaturization can also be promoted in the lifting direction of the base 35.

[0099] Furthermore, the four drive motors 47 themselves include magnetic reduction units 5 that decelerate the rotational motion of the drive motors 47 by magnetic force, or magnetic reduction units 58 that decelerate the rotational motion of the drive motors 47 by magnetic force are included between the movable body (Z-axis movable body 46) and the four drive motors 47. As a result, the worktable 30 can achieve effects such as reduced power consumption, miniaturization, weight reduction, and reduced vibration.

[0100] Furthermore, the magnetic reduction unit 58 is a magnetic gear motor 58A that has a stator 581, a high-speed rotor 582 and a low-speed rotor 583 coaxial with the stator 581, and constitutes the drive motor 47 itself. By adopting the magnetic gear motor 58A in this way, the worktable 30 can promote the miniaturization of the drive motor 47 itself, thereby further promoting the miniaturization of the worktable 30 as a whole (e.g., the height in the Z-axis direction).

[0101] Furthermore, the magnetic reduction unit 58 includes a magnetic reduction mechanism 58B between the four movable bodies (Z-axis movable body 46) and the four drive motors 47, each having a stator 586 and a high-speed rotor 587 and a low-speed rotor 588 coaxial with the stator 586. Thus, even with the magnetic reduction mechanism 58B included, the worktable 30 can smoothly reduce the rotation of the drive motors 47 to raise and lower the Z-axis movable body 46. Therefore, a small drive motor 47 can be used, resulting in a reduction in the overall size of the worktable 30.

[0102] Alternatively, the second aspect of the present invention is an inspection device 1, which has a stage 30 for placing and transporting a substrate (wafer W), and for pressing a probe 16 against the transported substrate to inspect the electrical characteristics of the substrate. The stage 30 has: a base 35 for placing the transported object (wafer W); four movable bodies (Z-axis movable bodies 46) that support the base 35 in a height-adjustable manner; four drive motors 47 that are correspondingly provided with each of the four movable bodies and cause the four movable bodies to be raised and lowered individually; four guide parts 48 that guide the raising and lowering of each of the four movable bodies; and a support frame 41, 41A, 41B that is continuous in a direction orthogonal to the raising and lowering direction of the base 35 and has walls 43a to 43h parallel to the raising and lowering direction, and all four guide parts 48 are fixed on the walls 43a to 43h.

[0103] Furthermore, the third aspect of the present invention is a method of operating the worktable 30, comprising: a transport step for transporting a base 35; and a lifting step for individually driving four drive motors 47 and lifting the base 35 by means of four movable bodies (Z-axis movable bodies 46) respectively provided on the four drive motors 47. In the process of lifting the base 35, in a support frame 41, 41A, 41B that is continuous in a direction orthogonal to the lifting direction of the base 35, the lifting of each of the four movable bodies is guided by each of the four guide portions 48 fixed to the wall surfaces 43a to 43h parallel to the lifting direction.

[0104] In the second and third methods, the orientation of the base 35 can be properly adjusted, thereby promoting the uniformity of the load applied to the base 35.

[0105] The workbench 30, inspection device 1, and operation method of the workbench 30 disclosed herein are illustrative and not limiting in all respects. The embodiments can be modified and improved in various ways without departing from the appended claims and their spirit. The items described in the above embodiments may be otherwise configured, and may be combined, without contradiction.

Claims

1. A workbench, comprising: A base; Four movable bodies support the aforementioned base in a liftable manner; Four drive motors are provided, each corresponding to one of the four movable bodies, so that the four movable bodies can be individually raised and lowered; Four guide sections guide the raising and lowering of each of the four movable bodies. as well as A support frame, which is continuous in a direction orthogonal to the lifting direction of the aforementioned base and has a wall parallel to the lifting direction, and all four aforementioned guide portions are fixed on this wall. The aforementioned support frame has a pair of side walls and a connecting wall connecting the pair of side walls in a direction orthogonal to the aforementioned lifting direction, thus forming an H-shape when viewed from above. The four movable bodies, the four drive motors, and the four guide parts are arranged between the pair of side walls. The aforementioned support frame has two of the four guide portions fixed on one of the aforementioned wall surfaces of the connecting wall, and the remaining two of the four guide portions fixed on the other of the aforementioned wall surfaces of the connecting wall.

2. The workbench according to claim 1, wherein, include: The control unit sets a target position for each of the four drive motors during the lifting and lowering of the base, and controls the operation of the four drive motors based on the target positions; and Four torque sensors are respectively installed on the four drive motors to detect the torque of the drive motors. The control unit corrects the target position of each of the four drive motors based on the torque fed back from each of the four torque sensors.

3. The workbench according to claim 2, wherein, Based on the torque of the four torque sensors, the control unit identifies the tilt state of the base and calculates a correction value for the target position of each of the four drive motors according to the tilt state of the base.

4. The worktable according to any one of claims 1 to 3, wherein, The four movable bodies have a lateral extension connected to each of the four drive motors, and a longitudinal extension extending orthogonally to the extension direction of the lateral extension and guided by each of the four guides.

5. The worktable according to claim 4, wherein, The aforementioned support frame and the aforementioned four guide sections extend along the aforementioned lifting direction in a manner longer than the installation positions of the aforementioned four drive motors.

6. The worktable according to any one of claims 1 to 3, wherein, The four drive motors mentioned above are direct drive motors.

7. The worktable according to any one of claims 1 to 3, wherein, The four drive motors themselves include a magnetic deceleration unit that slows down the rotational motion of the drive motors by magnetic force, or a magnetic deceleration unit that slows down the rotational motion of the drive motors by magnetic force is included between the four movable bodies and the four drive motors.

8. The workbench according to claim 7, wherein, The aforementioned magnetic reduction unit is a magnetic gear motor having a stator, a high-speed rotor and a low-speed rotor coaxial with the stator, and constituting the aforementioned drive motor itself.

9. The workbench according to claim 7, wherein, The magnetic reduction unit includes a magnetic reduction mechanism with a stator and a high-speed rotor and a low-speed rotor coaxial with the stator between the four movable bodies and the four drive motors.

10. An inspection apparatus comprising a stage for holding and transporting a substrate, and for contacting the transported substrate with probes to inspect the electrical characteristics of the substrate. The above-mentioned workbench has: A base; Four movable bodies support the aforementioned base in a liftable manner; Four drive motors are provided, each corresponding to one of the four movable bodies, so that the four movable bodies can be individually raised and lowered; Four guide sections guide the raising and lowering of each of the four movable bodies. as well as A support frame, which is continuous in a direction orthogonal to the lifting direction of the aforementioned base and has a wall parallel to the lifting direction, and all four aforementioned guide portions are fixed on this wall. The aforementioned support frame has a pair of side walls and a connecting wall connecting the pair of side walls in a direction orthogonal to the aforementioned lifting direction, thus forming an H-shape when viewed from above. The four movable bodies, the four drive motors, and the four guide parts are arranged between the pair of side walls. The aforementioned support frame has two of the four guide portions fixed on one of the aforementioned wall surfaces of the connecting wall, and the remaining two of the four guide portions fixed on the other of the aforementioned wall surfaces of the connecting wall.

11. A method for operating a worktable, comprising: The handling process involves moving a base; and The lifting process involves individually driving four drive motors, and using four movable parts respectively located on the four drive motors to raise and lower the aforementioned base. In the above lifting process, In a continuous support frame along a direction orthogonal to the lifting direction of the aforementioned base, the lifting of each of the four movable bodies is guided by each of four guide parts fixed to a wall parallel to the aforementioned lifting direction. The aforementioned support frame has a pair of side walls and a connecting wall connecting the pair of side walls in a direction orthogonal to the aforementioned lifting direction, thus forming an H-shape when viewed from above. The four movable bodies, the four drive motors, and the four guide parts are arranged between the pair of side walls. The aforementioned support frame has two of the four guide portions fixed on one of the aforementioned wall surfaces of the connecting wall, and the remaining two of the four guide portions fixed on the other of the aforementioned wall surfaces of the connecting wall.

Images