Maintaining the organization

Abstract

A holding mechanism capable of holding multiple types of objects is provided. [Solution] A holding mechanism capable of holding a first object and a second object of different sizes, comprising: a holding unit including a base, multiple arms attached to the base, and multiple holding parts provided at the tips of the arms for holding the first object and the second object; a guide unit for guiding the movement of at least one arm so that the multiple holding parts move closer to or away from each other; and a switching unit for switching between a state in which the first object or the second object is held by the multiple holding parts and a state in which the hold of the first object or the second object by the multiple holding parts is released by moving the multiple holding parts closer to or away from each other; by rotating the base relative to the guide unit, the movement of the arms is guided by the guide unit, and the multiple holding parts move between a first position for holding the first object and a second position for holding the second object.

Description

[Technical Field]

[0001] The present invention relates to a holding mechanism for holding an object. [Background technology]

[0002] In the device chip manufacturing process, a wafer is used, on which devices are formed in multiple regions defined by streets (planned division lines) set in a grid pattern. Device chips each including a device are obtained by dividing the wafer along the streets and singulating the wafer. Furthermore, a package substrate is formed by mounting multiple device chips on a predetermined substrate and covering and sealing the mounted device chips with a resin layer (mold resin). Package devices each including multiple packaged device chips are manufactured by dividing the package substrate along the streets and singulating the wafer. Device chips and package devices are incorporated into various electronic devices, such as mobile phones and personal computers.

[0003] When dividing a workpiece such as a wafer or a package substrate, the workpiece is processed using various processing devices. For example, the workpiece is divided using a cutting device that cuts the workpiece with an annular cutting blade or a laser processing device that processes the workpiece with a laser. In addition, the workpiece before division is thinned and flattened by grinding using a grinding device or polishing using a polishing device.

[0004] The processing device described above is equipped with a transport unit that transports the workpiece. The transport unit includes a holding mechanism that holds the workpiece and a moving mechanism that moves the holding mechanism. When the processing device processes the workpiece, the workpiece is held by the holding mechanism of the transport unit and transported to a predetermined location at a predetermined time.

[0005] For example, a holding mechanism may include multiple suction pads that are in contact with the surface of the workpiece and apply suction to the suction pads to hold the workpiece. However, when the suction pads come into contact with the workpiece, there is a risk that the workpiece may be scratched or foreign matter may adhere to it. To address this issue, a holding mechanism with multiple holding parts that hold the outer periphery of the workpiece has been proposed (see Patent Document 1). Using such a holding mechanism reduces the contact area between the workpiece and the holding mechanism, thereby preventing scratches on the workpiece and foreign matter from adhering to it. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-258450 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, when using a holding mechanism that holds the outer periphery of an object, such as a workpiece, with multiple holding parts, the arrangement of the multiple holding parts is set according to the size of the object. However, in a processing device or the like that processes various types of objects, it is necessary to hold objects of different sizes using the holding mechanism. In this case, multiple holding mechanisms corresponding to the different object sizes must be prepared in advance, and the holding mechanisms must be replaced when the object size is changed. This increases the cost and labor required to hold the objects. Furthermore, if the transport and processing of the objects is interrupted due to the replacement of the holding mechanisms, productivity decreases.

[0008] The present invention has been made in view of the above problem, and has as its object to provide a holding mechanism capable of holding a plurality of types of objects of different sizes. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a holding mechanism capable of holding a first object and a second object of different sizes, the holding mechanism comprising: a base; a plurality of arms attached to the base; and a plurality of holding portions provided at the tip of the arms and contacting the outer peripheries of the first object and the second object to hold the first object and the second object; a guide unit that guides the movement of at least one of the arms so that the plurality of holding portions move closer to or away from each other; and a switching unit that switches between a state in which the first object or the second object is held by the plurality of holding portions and a state in which the hold of the first object or the second object by the plurality of holding portions is released by moving the plurality of holding portions closer to or away from each other, and by rotating the base relative to the guide unit, the movement of the arms is guided by the guide unit, and the plurality of holding portions move between a first position for holding the first object and a second position for holding the second object.

[0010] Preferably, the holding mechanism further includes a fixing unit capable of fixing the plurality of holding portions at the first position and the second position. [Effects of the Invention]

[0011] A holding mechanism according to one aspect of the present invention guides the movement of an arm so that a holding portion provided at the tip of the arm moves between a first position for holding a first object and a second position for holding a second object. This allows the holding mechanism to hold first and second objects of different sizes. As a result, it is no longer necessary to prepare multiple holding mechanisms according to the type of object or to replace holding mechanisms when changing objects. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. [Figure 2] FIG. 2(A) is a plan view showing the holding unit, and FIG. 2(B) is a front view showing the holding unit. [Figure 3]FIG. 3(A) is a plan view showing the induction unit, and FIG. 3(B) is a front view showing the induction unit. [Figure 4] FIG. 4(A) is a plan view showing the fixing unit and the switching unit, and FIG. 4(B) is a front view showing the fixing unit and the switching unit. [Figure 5] FIG. 5(A) is a partial cross-sectional front view showing the holding mechanism before integration, and FIG. 5(B) is a partial cross-sectional front view showing the holding mechanism after integration. [Figure 6] FIG. 6(A) is a plan view showing the holding mechanism in a mode for holding a first object, and FIG. 6(B) is a plan view showing the holding mechanism in a mode for holding a second object. [Figure 7] FIG. 7(A) is a plan view showing the holding unit in the first mode, and FIG. 7(B) is a plan view showing the fixing unit and the switching unit in the first mode. [Figure 8] FIG. 8(A) is a partially cross-sectional front view showing the fixed unit when switching from the first mode to the second mode, and FIG. 8(B) is a plan view showing the fixed unit and the switching unit when switching from the first mode to the second mode. [Figure 9] FIG. 9(A) is a plan view showing the holding unit in the second mode, and FIG. 9(B) is a plan view showing the fixing unit and the switching unit in the second mode. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below with reference to the accompanying drawings. First, a configuration example of a holding mechanism according to this embodiment will be described. Figure 1 is a front view showing a holding mechanism (holding unit) 2 capable of holding a plurality of types of objects of different sizes.

[0014] The holding mechanism 2 is configured to be able to hold an object (first object) 11A and an object (second object) 11B of different sizes. A moving mechanism (moving unit) 4 that moves the holding mechanism 2 is connected to the holding mechanism 2. There is no limitation on the type of moving mechanism 4, and for example, a ball screw type moving mechanism, a robot arm, etc. can be used. The holding mechanism 2 and the moving mechanism 4 form a transport unit that transports the objects 11A and 11B.

[0015] For example, the holding mechanism 2 and the moving mechanism 4 are mounted on a processing device that processes objects. In this case, the objects 11A and 11B correspond to the workpieces to be processed by the processing device, and the holding mechanism 2 holds the objects 11A and 11B within the processing device. Examples of processing devices include a cutting device that cuts a workpiece, a grinding device that grinds a workpiece, a polishing device that polishes a workpiece, and a laser processing device that performs laser processing on a workpiece.

[0016] The cutting device is equipped with a processing unit (cutting unit) that cuts the workpiece. The cutting unit has a spindle, and an annular cutting blade is attached to the tip of the spindle. The workpiece is cut by rotating the cutting blade and cutting into it.

[0017] The grinding device includes a processing unit (grinding unit) that grinds the workpiece. The grinding unit includes a spindle, and an annular grinding wheel containing multiple grinding stones is attached to the tip of the spindle. The grinding wheel is rotated while the grinding stones are brought into contact with the workpiece, thereby grinding the workpiece.

[0018] The polishing device is equipped with a processing unit (polishing unit) that polishes the workpiece. The polishing unit has a spindle, and a disc-shaped polishing pad is attached to the tip of the spindle. The workpiece is polished by rotating the polishing pad and bringing it into contact with the workpiece.

[0019] A laser processing device includes a processing unit (laser irradiation unit) that performs laser processing on a workpiece. For example, the laser irradiation unit includes a laser oscillator that pulses a laser of a predetermined wavelength, and a condenser that condenses the laser beam emitted from the laser oscillator. The laser beam emitted from the laser irradiation unit is condensed on the surface, backside, or inside of the workpiece, thereby performing laser processing on the workpiece.

[0020] The holding mechanism 2 and the moving mechanism 4 may also be mounted on a processing device other than a processing device. For example, the holding mechanism 2 and the moving mechanism 4 may be mounted on a cleaning device that cleans objects or an inspection device that inspects objects.

[0021] The transport unit, which is composed of the holding mechanism 2 and the moving mechanism 4, transports the objects 11A and 11B within the processing device, carries the objects 11A and 11B into the processing device, carries the objects 11A and 11B out of the processing device, etc. The transport unit may also transport the objects 11A and 11B between processing devices.

[0022] For example, objects 11A and 11B are disk-shaped wafers made of a semiconductor material such as single crystal silicon. Objects 11A and 11B are different sizes, and the outer edge of object 11A does not coincide with the outer edge of object 11B. For example, object 11A is a wafer with a diameter of 8 inches (200 mm), and object 11B is a wafer with a diameter of 6 inches (150 mm), with the diameter of object 11A being larger than the diameter of object 11B.

[0023] The objects 11A and 11B are divided into a plurality of rectangular regions by a plurality of streets (planned division lines) arranged in a grid pattern so as to intersect with each other. Furthermore, devices such as ICs (Integrated Circuits), LSIs (Large Scale Integration), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices are formed in each of the regions divided by the streets.

[0024] The objects 11A and 11B are processed by a cutting device or a laser processing device and divided along the streets to produce a plurality of device chips, each including a device. Furthermore, the objects 11A and 11B before division are processed by a grinding device or a polishing device to thin them, thereby obtaining thinned device chips.

[0025] However, there are no restrictions on the type, material, size, shape, structure, etc. of the objects 11A and 11B. For example, the objects 11A and 11B may be wafers (substrates) made of semiconductors other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass, ceramics, resin, metal, etc. Furthermore, there are no restrictions on the type, number, shape, structure, size, arrangement, etc. of devices, and the objects 11A and 11B do not necessarily have devices formed thereon.

[0026] Furthermore, the objects 11A and 11B may be package substrates such as CSP (Chip Size Package) substrates and QFN (Quad Flat Non-leaded package) substrates. For example, a package substrate is formed by mounting multiple device chips on a predetermined substrate and then covering and sealing the mounted device chips with a resin layer (mold resin). By dividing the package substrate into individual pieces, package devices including multiple packaged device chips are manufactured.

[0027] The holding mechanism 2 is configured to include a holding unit 10, a guiding unit 40, a fixing unit 50, and a switching unit 70, and selectively holds one of the object 11A and the object 11B. An example of the configuration of each component of the holding mechanism 2 will be described below.

[0028] Fig. 2(A) is a plan view showing the holding unit 10, and Fig. 2(B) is a front view showing the holding unit 10. The holding unit 10 includes a base 12, a plurality of arms 16 attached to the base 12, and a plurality of holding parts 26 provided at the tip ends of the plurality of arms 16. The plurality of holding parts 26 contact the outer periphery of the object 11A to hold the object 11A, and contact the outer periphery of the object 11B to hold the object 11B.

[0029] For example, the base 12 is a disk-shaped plate made of a metal such as aluminum or stainless steel (SUS), or a hard resin, and has a first surface (upper surface) 12a and a second surface (lower surface) 12b that are generally parallel to each other. A cylindrical support shaft 14 that supports the base 12 is connected to the center of the base 12 on the side of the second surface 12b. The diameter of the support shaft 14 is smaller than the diameter of the base 12, and the base 12 and the support shaft 14 are arranged concentrically. Therefore, only the center of the base 12 is supported by the support shaft 14, and the outer periphery of the base 12 is not supported by the support shaft 14.

[0030] The base 12 is also provided with a plurality of screw holes 12c into which positioning screws 62 (see FIGS. 4(A) and 4(B)), which will be described later, are inserted. The screw holes 12c are formed so as to penetrate the base 12 in the thickness direction, and are arranged at approximately equal intervals (120° intervals) around the circumference of the base 12. In this embodiment, as an example, a case will be described in which three screw holes 12c are provided in the base 12, but the number of screw holes 12c is set appropriately depending on the number of positioning screws 62.

[0031] A plurality of arms 16 are attached to the outer periphery of the base 12. In this embodiment, as an example, a case will be described in which three sets of arms 16 are attached to the base 12. However, the number of arms 16 may be two or four or more. The arms 16 include a fixed portion 18 fixed to the base 12, a first arm portion 20 connected to the fixed portion 18, and a second arm portion 22 connected to the first arm portion 20.

[0032] The fixing portions 18 are columnar members made of metal, resin, or the like, and are fixed to the outer periphery of the base 12 so as to protrude upward from the first surface 12a of the base 12. The multiple fixing portions 18 are arranged at approximately equal intervals (120° intervals) along the circumferential direction of the base 12.

[0033] The first arm unit 20 is a columnar member made of metal, resin, or the like, and is arranged along a direction intersecting the vertical direction (for example, the horizontal direction). The base end (one end) of the first arm unit 20 is connected to the upper end of the fixed unit 18 by a screw 24A. The first arm unit 20 is attached to the fixed unit 18 in a state where it can rotate about a rotation axis that passes through the base end of the first arm unit 20 and is generally parallel to the vertical direction.

[0034] The second arm unit 22 is a columnar member made of metal, resin, or the like, and is arranged along a direction intersecting the horizontal direction (for example, the vertical direction). The base end (upper end) of the second arm unit 22 is connected to the tip end (other end) of the first arm unit 20 by a screw 24B. The second arm unit 22 is attached to the first arm unit 20 in a state where it can rotate about a rotation axis that passes through the tip end of the first arm unit 20 and is generally parallel to the vertical direction.

[0035] A holding portion 26 is provided at the tip (lower end) of second arm portion 22. Holding portion 26 includes a support member 28 fixed to the tip of second arm portion 22, and one or more (two in FIGS. 2(A) and 2(B)) holding members 30 fixed to the underside of support member 28.

[0036] For example, support member 28 is a rectangular parallelepiped member made of metal, resin, or the like, and is arranged along the horizontal direction. The orientation of holding portion 26 is maintained so that the length direction of holding portion 26 is along the tangential direction of base 12. Note that support member 28 may be the same member as second arm portion 22, or may be a member separate from second arm portion 22.

[0037] The holding member 30 is made of metal, resin, or the like, and supports and holds the objects 11A and 11B from below. For example, the holding member 30 includes a cylindrical connecting portion 32 connected to the lower surface of the support member 28, and a disk-shaped contact portion 34 connected to the tip (lower end) of the connecting portion 32. The diameter of the contact portion 34 is larger than the diameter of the connecting portion 32, and the connecting portion 32 and the contact portion 34 are arranged concentrically. That is, the holding member 30 is formed in an inverted T shape when viewed from the front. Furthermore, the portion of the upper surface of the contact portion 34 that is not connected to the connecting portion 32 is an annular flat surface roughly parallel to the horizontal plane, and forms a contact surface 34a that contacts the lower surface of the outer periphery of the objects 11A and 11B to support the objects 11A and 11B.

[0038] The holding unit 10 holds the object 11A or the object 11B by supporting the object 11A or the object 11B from below with the contact surfaces 34a of the multiple contact portions 34 (see FIG. 1). In addition, by rotating the arm 16 and moving the multiple holding portions 26 closer to or farther away from each other, it is possible to switch between a mode for holding the large-sized object 11A and a mode for holding the small-sized object 11B. Details of switching between holding the object 11A and holding the object 11B will be described later.

[0039] Fig. 3(A) is a plan view showing the guide unit 40, and Fig. 3(B) is a front view showing the guide unit 40. The guide unit 40 guides the movement of at least one arm 16 so that the multiple holding portions 26 (see Figs. 2(A) and 2(B)) of the holding unit 10 move closer to or farther away from each other.

[0040] For example, the induction unit 40 is configured by an induction plate 42. The induction plate 42 is a disk-shaped member made of metal such as aluminum or SUS, or hard resin, and has a first surface (upper surface) 42a and a second surface (lower surface) 42b that are generally parallel to each other. The diameter of the induction plate 42 is set so that the induction plate 42 overlaps at least the arms 16 when the holding unit 10 (see FIGS. 2(A) and 2(B)) and the induction plate 42 are arranged one on top of the other.

[0041] The guide plate 42 has a plurality of guide portions 44 that guide the movement of the arms 16. For example, the guide portions 44 are oval through-holes that penetrate the guide plate 42 in the thickness direction and are formed along the radial direction of the guide plate 42. The guide portions 44 are provided in the same number as the arms 16 (three in FIG. 3(A)), and are arranged at approximately equal intervals (120° intervals) along the circumferential direction of the guide plate 42.

[0042] The guide portion 44 has a first end 44a located on the outer peripheral edge side of the guide plate 42 and a second end 44b located on the center side of the guide plate 42. The width of the guide portion 44 (through hole) is approximately equal to the width of the second arm portion 22 (see FIG. 2(B)) provided on the arm 16. Then, as will be described later, the second arm portion 22 is inserted into the guide portion 44. This restricts movement of the second arm portion 22 in directions other than the radial direction of the guide plate 42, and guides the movement of the second arm portion 22 in the radial direction of the guide plate 42.

[0043] However, the configuration of the guide portion 44 is not limited to a through hole. For example, the guide portion 44 may be configured by a guide mechanism such as a guide rail that moves the second arm portion 22 along the radial direction of the guide plate 42.

[0044] Fig. 4(A) is a plan view showing the fixed unit 50 and the switching unit 70, and Fig. 4(B) is a front view showing the fixed unit 50 and the switching unit 70. Note that for ease of explanation, Fig. 4(A) shows the guide plate 52 and the rotating member 60 of the fixed unit 50 side by side, but in reality, the guide plate 52 and the rotating member 60 are arranged so as to overlap in the vertical direction (the same applies to Figs. 7(B), 8(B), and 9(B) described below).

[0045] The fixing unit 50 is a mechanism that can fix the plurality of holding parts 26 (see FIGS. 2A and 2B) provided in the above-described holding unit 10 at a first position for holding the object 11A and at a second position for holding the object 11B. As described above, the diameter of the object 11A is larger than the diameter of the object 11B (see FIG. 1). Therefore, the distance between the plurality of holding parts 26 arranged at the first position is longer than the distance between the plurality of holding parts 26 arranged at the second position.

[0046] The fixing unit 50 has an induction plate 52. The induction plate 52 is a disk-shaped member made of metal such as aluminum or SUS, or hard resin, and has a first surface (upper surface) 52a and a second surface (lower surface) 52b that are generally parallel to each other. The diameter of the induction plate 52 is set so that when the holding unit 10 (see FIGS. 2(A) and 2(B)) and the induction plate 52 are arranged so that they overlap with at least the fixing portions 18 (see FIGS. 2(A) and 2(B)) of the multiple arms 16.

[0047] The guide plate 52 has a plurality of guide portions 54 that guide the movement of the arms 16. For example, the guide portions 54 are arc-shaped through holes that penetrate the guide plate 52 in the thickness direction, and are formed on the outer periphery of the guide plate 52 along the circumferential direction of the guide plate 52. The guide portions 54 are provided in the same number as the arms 16 (three in FIG. 4(A)), and are arranged at approximately equal intervals (120° intervals) along the circumferential direction of the guide plate 52.

[0048] The guide portion 54 has a first end 54a corresponding to one end of the arc and a second end 54b corresponding to the other end of the arc. The width of the guide portion 54 (through hole) is approximately equal to the width of the fixing portion 18 (see FIG. 2(B)) provided on the arm 16. As will be described later, the fixing portion 18 is inserted into the guide portion 54. This restricts movement of the fixing portion 18 in directions other than the circumferential direction of the guide plate 52, and guides the movement of the fixing portion 18 in the circumferential direction of the guide plate 52.

[0049] However, the configuration of the guide portion 54 is not limited to a through hole. For example, the guide portion 54 may be configured by a guide mechanism such as a guide rail that moves the fixing portion 18 of the arm 16 along the circumferential direction of the guide plate 52.

[0050] The guide plate 52 is also provided with a plurality of screw holes 56 into which positioning screws 62, which will be described later, are inserted. The screw holes 56 are arc-shaped through-holes that penetrate the guide plate 52 in the thickness direction, and are formed along the circumferential direction of the guide plate 52 closer to the center of the guide plate 52 (radially inward) than the plurality of guide portions 54. The screw holes 56 are provided in the same number as the positioning screws 62 (three in FIG. 4(A)), and are arranged at approximately equal intervals (120° intervals) along the circumferential direction of the guide plate 52.

[0051] The screw hole 56 has an arc-shaped screw moving portion 56a, a circular first screw fixing portion 56b connected to one end of the screw moving portion 56a, and a circular second screw fixing portion 56c connected to the other end of the screw moving portion 56a. A setting screw 62 (described below) moves along the screw moving portion 56a and is fixed (locked) at the first screw fixing portion 56b or the second screw fixing portion 56c. The function of the screw hole 56 will be described in detail later.

[0052] The fixing unit 50 also includes a rotating member 60 that rotates the base 12 (see FIGS. 2(A) and 2(B)) of the holding unit 10. For example, the rotating member 60 is a disk-shaped plate (rotating plate) made of metal, resin, or the like, and is fixed to the base 12 of the holding unit 10 by a plurality of positioning screws 62. Note that, in this embodiment, a case where three positioning screws 62 are used will be described as an example, but there is no limit to the number of positioning screws 62.

[0053] The rotating member 60 is provided with a plurality of threaded holes (not shown) into which the positioning screws 62 are inserted. The plurality of threaded holes are formed at approximately equal intervals (120° intervals) along the circumferential direction of the rotating member 60 so as to penetrate the rotating member 60 in the thickness direction. The number of threaded holes provided is the same as the number of positioning screws 62. The plurality of positioning screws 62 are then inserted into the threaded holes of the rotating member 60, respectively.

[0054] As shown in FIG. 4(B), the set screw 62 includes a head 62a, a columnar first shank 62b connected to the head 62a, and a columnar second shank 62c connected to the first shank 62b. The diameter of the head 62a is larger than the diameters of the first shank 62b and the second shank 62c, and the diameter of the second shank 62c is larger than the diameter of the first shank 62b. Specifically, the diameter of the first shank 62b is equal to or smaller than the width of the screw moving portion 56a of the screw hole 56 (see FIG. 4(A)). The diameter of the second shank 62c is larger than the width of the screw moving portion 56a of the screw hole 56 and is approximately equal to the diameters of the first screw fixing portion 56b and the second screw fixing portion 56c of the screw hole 56 (see FIG. 4(A)).

[0055] A spring 64 is wound around the first shaft portion 62b of the set screw 62. For example, the spring 64 is a cylindrical compression coil spring made of stainless steel, piano wire, or the like, and is attached so as to surround the first shaft portion 62b of the set screw 62.

[0056] Furthermore, the fixing unit 50 includes a switching unit 70 that switches between holding the objects 11A and 11B and releasing the holding of the objects 11A and 11B. The switching unit 70 switches between a state in which the objects 11A and 11B are held by the multiple holding parts 26 and a state in which the holding of the objects 11A and 11B by the multiple holding parts 26 is released, by moving the multiple holding parts 26 (see FIGS. 2(A) and 2(B)) closer to or farther away from each other.

[0057] For example, the switching unit 70 is configured by an air cylinder, and includes a cylindrical cylinder 72 and a columnar piston rod 74 housed in the cylinder 72. The tip of the piston rod 74 protrudes outside the cylinder 72.

[0058] The switching unit 70 is disposed so that the piston rod 74 is inclined with respect to the radial direction of the guide plate 52. The tip of the piston rod 74 is connected to the connection portion 58 of the guide plate 52. For example, the connection portion 58 is a protrusion provided on the outer periphery of the guide plate 52, and the tip of the piston rod 74 is fixed to the connection portion 58 by a fixing device such as a fixing screw.

[0059] When the switching unit 70 is operated, the piston rod 74 moves in the direction of ejection from the cylinder 72 or the direction of insertion into the cylinder 72, and the portion of the piston rod 74 that protrudes from the cylinder 72 expands or contracts. This causes the guide plate 52 to rotate a predetermined angle in both directions around a rotation axis that passes through the center of the guide plate 52 and is generally parallel to the vertical direction.

[0060] The holding mechanism 2 is configured by integrating the above-described holding unit 10, guide unit 40, fixing unit 50, and switching unit 70. Fig. 5(A) is a partial cross-sectional front view showing the holding mechanism 2 before integration, and Fig. 5(B) is a partial cross-sectional front view showing the holding mechanism 2 after integration. For simplification, Figs. 5(A) and 5(B) show two sets of arms 16 and two positioning screws 62 (the same applies to Fig. 8(A) described below).

[0061] First, with the arm 16 of the holding unit 10 detached from the base 12, the fixing portion 18 of the arm 16 is inserted into the guide portion 54 (through hole) of the guide plate 52. Then, the lower end of the fixing portion 18 is fixed to the base 12. As a result, the base 12 and the arm 16 are connected to sandwich the guide plate 52, and the guide plate 52 is placed on the base 12. Then, the screw hole 12c of the base 12 and the screw hole 56 of the guide plate 52 are connected.

[0062] The base 12 and the rotating member 60 are connected by a plurality of positioning screws 62. For example, the positioning screw 62 includes a bolt corresponding to the head 62a and the first shaft portion 62b, and a cylindrical nut (pin) corresponding to the second shaft portion 62c. The bolt has a male threaded portion on the part corresponding to the first shaft portion 62b, and the nut has a female threaded portion on the inside. The bolt and the nut are connected by screwing the male threaded portion of the bolt into the female threaded portion of the nut. This forms a positioning screw 62 in which the head 62a, the first shaft portion 62b, and the second shaft portion 62c can be separated.

[0063] Then, the positioning screw 62 is attached to the rotating member 60, the guide plate 52, and the base 12. Specifically, the second shaft portion 62c is removed from the first shaft portion 62b of the positioning screw 62, and the first shaft portion 62b is inserted from above into a threaded hole (not shown) provided in the rotating member 60. Then, after the spring 64 is attached to the first shaft portion 62b protruding downward from the rotating member 60, the tip portion (lower end portion) of the first shaft portion 62b is inserted from above into the threaded hole 56 of the guide plate 52 and the threaded hole 12c of the base 12.

[0064] Thereafter, the second shaft portion 62c of the setting screw 62 is inserted into the threaded hole 12c from the underside of the base 12 and fixed to the tip of the first shaft portion 62b. As a result, the base 12 and the rotating member 60 are connected by the setting screw 62, and the base 12 and the rotating member 60 become rotatable as a unit. On the other hand, the threaded hole 56 of the guide plate 52 is formed in an arc shape (see FIG. 4(A)), and the setting screw 62 is movable inside the threaded hole 56. Therefore, the guide plate 52 does not always rotate as a unit with the base 12 and the rotating member 60.

[0065] Furthermore, the second arm portion 22 of the arm 16 is inserted into the guide portion 44 of the guide plate 42 (see FIG. 3(A)) while being removed from the first arm portion 20. Thereafter, the upper end portion of the second arm portion 22 is attached to the tip portion of the first arm portion 20. As a result, the guide plate 42 is disposed between the first arm portion 20 and the holding portion 26.

[0066] Through the above procedure, the holding unit 10, the guiding unit 40, the fixing unit 50, and the switching unit 70 are integrated to form the holding mechanism 2. Then, by rotating the base 12 of the holding unit 10 relative to the guiding unit 40, the multiple holding parts 26 can be positioned at a first position for holding a large-sized object 11A (see FIG. 1) and at a second position for holding a small-sized object 11B (see FIG. 1).

[0067] 6(A) is a plan view showing the holding mechanism 2 in a mode for holding the object 11A. When the holding mechanism 2 is used to hold a large-sized object 11A (e.g., an 8-inch wafer), the fixed portion 18 of the arm 16 is positioned at the first end 54a of the guide portion 54, and the second arm portion 22 of the arm 16 is positioned at the first end 44a of the guide portion 44. This positions the holding portion 26 at a first position suitable for holding the object 11A.

[0068] 6(B) is a plan view showing the holding mechanism 2 in a mode for holding the object 11B. When the holding mechanism 2 is used to hold a small-sized object 11B (e.g., a 6-inch wafer), the fixing portion 18 of the arm 16 is positioned at the second end 54b of the guide portion 54, and the second arm portion 22 of the arm 16 is positioned at the second end 44b of the guide portion 44. This positions the holding portion 26 at a second position suitable for holding the object 11B.

[0069] Next, details of switching the position of the holding portion 26 will be described. As an example in this embodiment, the operation of the holding mechanism 2 when the position of the holding portion 26 is switched from the first position to the second position will be described. Hereinafter, the state of the holding mechanism 2 in which the multiple holding portions 26 are positioned at the first position (see FIG. 6(A)) will be referred to as the first mode, and the state of the holding mechanism 2 in which the holding portions 26 are positioned at the second position (see FIG. 6(B)) will be referred to as the second mode.

[0070] Fig. 7(A) is a plan view showing the holding unit 10 in the first mode, and Fig. 7(B) is a plan view showing the fixing unit 50 and the switching unit 70 in the first mode. In the first mode, the rotation angles of the base 12 and the rotating member 60 relative to the guide plate 52 are set so that the set screw 62 is positioned in the first screw fixing portion 56b of the screw hole 56 provided in the guide plate 52. As a result, the arm 16 is disposed at the first end 44a of the guide portion 44 and the first end 54a of the guide portion 54 (see Fig. 6(A)), and the multiple holding portions 26 are positioned at the first position.

[0071] When the multiple holding parts 26 are arranged in the first position, the diameter of an imaginary circle passing through the inner ends (ends on the center side of the base 12) of the multiple holding members 30 becomes smaller than the diameter of the object 11A. This makes it possible for the multiple holding members 30 to hold the object 11A.

[0072] Furthermore, when the setting screw 62 is positioned in the first screw fixing portion 56b of the screw hole 56, the rotating member 60 and the setting screw 62 are urged upward by the restoring force of the spring 64 (see FIG. 5(B)), and the second shaft portion 62c of the setting screw 62 is fitted into the screw hole 56 (first screw fixing portion 56b). As a result, the setting screw 62 is locked (fixed) to the first screw fixing portion 56b of the guide plate 52, and the base 12, the rotating member 60, and the guide plate 52 are integrated by the setting screw 62.

[0073] When the switching unit 70 is operated to extend or retract the piston rod 74 while the base 12, guide plate 52, and rotating member 60 are integrated, the base 12, guide plate 52, and rotating member 60 rotate a predetermined angle relative to the stationary guide unit 40 (see FIG. 6(A)). As a result, the arm 16 moves slightly along the guide portion 44, and the multiple holding portions 26 also move slightly toward or away from each other. This allows the multiple holding portions 26 to be positioned at a holding position where they hold the object 11A and a release position where they release their hold of the object 11A.

[0074] When the plurality of holding portions 26 are positioned in the holding position, the holding portions 26 move radially inward from the object 11A, making it possible to hold the object 11A with the plurality of holding portions 26. On the other hand, when the plurality of holding portions 26 are positioned in the release position, the holding portions 26 move radially outward from the object 11A, and the holding of the object 11A by the plurality of holding portions 26 is released.

[0075] When the object held by the holding mechanism 2 is changed from object 11A to object 11B, the state of the holding mechanism 2 is switched from the first mode to the second mode. Fig. 8(A) is a partially cross-sectional front view showing the fixing unit 50 when switching from the first mode to the second mode, and Fig. 8(B) is a plan view showing the fixing unit 50 and the switching unit 70 when switching from the first mode to the second mode.

[0076] When switching the holding mechanism 2 from the first mode to the second mode, first, the rotating member 60 is pressed toward the guide plate 52 (see FIG. 8(A)). This causes the spring 64 to contract, bringing the rotating member 60 closer to the guide plate 52 and forcing the setting screw 62 into the screw hole 56 and the screw hole 12c. As a result, the second shank 62c of the setting screw 62 is pushed out from the screw hole 56 toward the screw hole 12c, and the first shank 62b of the setting screw 62 is positioned inside the screw hole 56. As a result, a gap is formed between the inner wall of the screw hole 56 and the first shank 62b, and the setting screw 62 is unlocked.

[0077] Next, the rotating member 60 is rotated while maintaining the pressure on the rotating member 60. Here, the diameter of the first shaft portion 62b of the setting screw 62 is set to be equal to or smaller than the width of the screw moving portion 56a of the screw hole 56 (see FIG. 8(B)). Therefore, when the rotating member 60 is pressed and the first shaft portion 62b is positioned inside the screw hole 56, the setting screw 62 becomes movable along the screw moving portion 56a of the screw hole 56. When the rotating member 60 is rotated in this state, the setting screw 62 moves along the screw moving portion 56a from the first screw fixing portion 56b to the second screw fixing portion 56c while the guide plate 52 is stationary.

[0078] When the set screw 62 moves from the first screw fixing portion 56b to the second screw fixing portion 56c, the base 12 rotates in conjunction with the set screw 62, and the multiple arms 16 attached to the base 12 move while being guided by the guide portions 44, 54 of the guide plates 42, 52 (see FIGS. 6(A) and 6(B)). As a result, the multiple holding portions 26 move closer to each other along the radial direction of the base 12 and are positioned at the second position.

[0079] 9(A) is a plan view showing the holding unit 10 in the second mode, and FIG. 9(B) is a plan view showing the fixing unit 50 and the switching unit 70 in the second mode. When the rotating member 60 rotates and the positioning screw 62 moves to the second screw fixing portion 56c of the screw hole 56, the pressure on the rotating member 60 is released.

[0080] When the pressure on the rotating member 60 is released, the rotating member 60 and the positioning screw 62 are pushed up by the restoring force of the spring 64 (see FIG. 5(B)). As a result, the second shaft portion 62c of the positioning screw 62 is fitted into the screw hole 56 (second screw fixing portion 56c). This locks (fixes) the positioning screw 62 to the second screw fixing portion 56c, and the base 12, the rotating member 60, and the guide plate 52 are again integrated by the positioning screw 62.

[0081] When the switching unit 70 is operated to extend or retract the piston rod 74 while the base 12, guide plate 52, and rotating member 60 are integrated, the base 12, guide plate 52, and rotating member 60 rotate a predetermined angle relative to the stationary guide unit 40 (see FIG. 6(A)). As a result, the arm 16 moves slightly along the guide portion 44, and the multiple holding portions 26 also move slightly toward or away from each other. This allows the multiple holding portions 26 to be positioned at a holding position where they hold the object 11B and a release position where they release their hold on the object 11B.

[0082] As described above, the state of the holding mechanism 2 can be easily switched from the first mode to the second mode by pressing and rotating the rotating member 60. Furthermore, switching from the second mode to the first mode can be performed in the same manner as switching from the first mode to the second mode. For example, switching between the first mode and the second mode is performed by an operator rotating the rotating member 60 while pressing it with a finger. However, the pressing and rotation of the rotating member 60 may be performed automatically by a dedicated actuator.

[0083] As described above, the holding mechanism 2 according to this embodiment guides the movement of the arm 16 so that the holding portion 26 provided at the tip of the arm 16 moves between a first position for holding the object 11A and a second position for holding the object 11B. This makes it possible for the holding mechanism 2 to hold the objects 11A and 11B of different sizes. As a result, it is no longer necessary to prepare multiple holding mechanisms according to the type of object or to replace the holding mechanism when changing the object.

[0084] In the present embodiment, the case has been described in which the movement of all of the arms 16 is guided by the guide units 44, 54, and all of the holders 26 move between the first position and the second position. However, the holding mechanism 2 only needs to be able to guide the movement of at least one arm 16 and move at least one holder 26. For example, if the holding mechanism 2 has three arms 16 and holders 26, the first mode and the second mode may be switched by guiding the movement of two of the arms 16 and moving two of the holders 26.

[0085] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0086] 11A Object (First Object) 11B Object (Second Object) 2 Retention mechanism (retention unit) 4. Mobile mechanism (mobile unit) 10 Holding Unit 12 Foundation 12a 1st side (top side) 12b 2nd side (bottom side) 12c screw hole 14 Support shaft 16 Arm 18 Fixed part 20 First arm section 22 Second arm section 24A, 24B screws 26 Holding part 28 Support member 30 Retaining member 32 Connecting part 34 Contact area 34a Contact surface 40 Guidance Unit 42 Induction Plate 42a 1st side (top side) 42b 2nd side (bottom side) 44 Guidance part 44a First end 44b Second end 50 fixed units 52 Induction Plate 52a 1st side (top side) 52b 2nd side (bottom side) 54 Guidance part 54a First end 54b Second end 56 screw holes 56a Screw moving part 56b First screw fixing part 56c Second screw fixing part 58 Connection 60 Rotating member 62 Set screw 62a head 62b First shaft 62c 2nd shaft part 64 Spring 70 Switching Unit 72 cylinders 74 Piston rod

Claims

1. A holding mechanism capable of holding a first object and a second object having different sizes, a holding unit including a base, a plurality of arms attached to the base, and a plurality of holding portions provided at the tips of the arms and contacting the outer peripheries of the first object and the second object to hold the first object and the second object; a guide unit that guides movement of at least one of the arms so that the plurality of holding portions move toward or away from each other; a switching unit that switches between a state in which the first object or the second object is held by the plurality of holding parts and a state in which the holding of the first object or the second object by the plurality of holding parts is released by moving the plurality of holding parts closer to or farther away from each other, A holding mechanism in which the movement of the arm is guided by the induction unit by rotating the base relative to the induction unit, and the multiple holding portions move between a first position for holding the first object and a second position for holding the second object.

2. The holding mechanism according to claim 1 , further comprising a fixing unit capable of fixing the plurality of holding portions at the first position and the second position.

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