Chip holding device

Abstract

The present invention suppresses a failure caused by an unexpected pressure change in an air path. Specifically, a chip holding device 1, which is for holding a chip 11 so as to be rotatable about an axis in a state where the chip 11 is in vacuum adhesion by using a collet 4, comprises: a holder 2 including a rotary shaft 21 that rotates about the axis and a fixing part 22 that fixes the rotary shaft 21 to a housing H1; an attachment 3 detachably attached to the rotary shaft 21; and the collet 4 provided on the attachment 3. The holder 2 includes: a first air path 5 through which a gas for causing the attachment 3 to vacuum-adhere to the rotary shaft 21 passes; a second air path 6 through which at least one of a gas for causing the chip 11 to vacuum-adhere to the collet 4 and a gas for releasing the vacuum adhesion between the collet 4 and the chip 11 passes; and a suppression structure 7 for suppressing occurrence of a pressure change in one path of the first air path 5 and the second air path 6 due to a pressure change in the other path.

Description

Chip holding device

[0001] The present invention relates to a chip holding device.

[0002] Technologies related to chip holding devices that pick up chips such as semiconductors using collets are known. For example, Patent Document 1 discloses a technique for magnetically holding an attachment that holds a collet to a holder in order to perform collet replacement with a simple configuration.

[0003] Japanese Patent Application Laid-Open No. 2022-156177

[0004] In the case of a configuration in which an attachment is held to a holder using permanent magnetism as in Patent Document 1, a relatively simple configuration can be achieved. However, since the attachment is attracted to the holder by magnetic attraction with a gap between the attachment and the holder, the attachment is mounted on the holder, there is a risk that the mounting position of the attachment will shift.

[0005] Also, when mounting, since the attachment and the holder collide at a certain speed due to magnetism, there is a risk that particles will be generated during the collision.

[0006] Therefore, the inventors considered adopting a method of mounting the attachment to the holder by vacuum suction. In the case of the vacuum suction method, by vacuum-sucking the attachment to the holder in a state where the attachment is in contact with the holder, the risk of displacement and particle generation can be reduced compared to the magnetic suction method.

[0007] On the other hand, vacuum suction technology is also used for holding chips by collets. Therefore, when adopting the vacuum suction method for the attachment, the holder needs to be provided with a plurality of air paths, an air path for vacuum-sucking the attachment to the holder and an air path for vacuum-sucking the chip to the collet included in the attachment.

[0008] Here, the holder may include a rotating wheel for changing the orientation of the tip held in the collet. If multiple air passages are provided in such a holder, air flowing through one air passage may leak into the other air passage, for example, through the gap between the rotating wheel and the stationary wheel, potentially adversely affecting the retention of the tip or attachment, such as displacement due to a decrease in suction pressure.

[0009] Therefore, in view of these problems, the present disclosure aims to provide a vacuum suction type chip holding device that can suppress malfunctions caused by unexpected pressure changes in the air path.

[0010] The chip holding device according to the present invention is a chip holding device that holds a chip so as to be rotatable around an axis while the chip is vacuum-adsorbed using a collet, and comprises a holder including a rotating shaft that rotates around the axis and a fixing part that fixes the rotating shaft to a housing, an attachment that is detachably attached to the rotating shaft and the collet provided on the attachment, wherein the holder includes a first air path through which a gas for vacuum-adsorbing the attachment to the rotating shaft passes, a second air path through which at least one of a gas for vacuum-adsorbing the chip to the collet and a gas for releasing the vacuum adsorption between the collet and the chip passes, and a suppression structure that suppresses the occurrence of a pressure change in the other air path due to a pressure change in one of the first air path and the second air path.

[0011] According to the chip holding device of the present invention, malfunctions caused by unexpected pressure changes in the air path can be suppressed.

[0012] This is a schematic diagram illustrating a chip holding device according to an embodiment. This is a schematic diagram illustrating how a chip is held by the chip holding device. This is a schematic diagram showing a chip holding device according to a first modification. This is a schematic diagram showing a chip holding device according to a second modification. This is a schematic diagram showing a chip holding device according to a third modification. This is a schematic diagram for explaining the problems that the chip holding device solves.

[0013] <Outline of Embodiments of the Present Invention> The outlines of embodiments of the present invention are listed and described below.

[0014] (1) The chip holding device according to the present invention is a chip holding device that holds a chip so as to be rotatable around an axis while the chip is vacuum-adsorbed using a collet, and comprises a holder including a rotating shaft that rotates around the axis and a fixing part that fixes the rotating shaft to a housing, an attachment that is detachably attached to the rotating shaft and the collet provided on the attachment, wherein the holder includes a first air path through which a gas for vacuum-adsorbing the attachment to the rotating shaft passes, a second air path through which at least one of a gas for vacuum-adsorbing the chip to the collet and a gas for releasing the vacuum adsorption between the collet and the chip passes, and a suppression structure that suppresses the occurrence of a pressure change in the other air path due to a pressure change in one of the first air path and the second air path.

[0015] By providing a suppression structure, malfunctions such as misalignment of the attachment caused by unexpected pressure changes in the first and second air paths can be suppressed.

[0016] (2) In the chip holding device described in (1) above, the suppression structure includes an independent structure in which the first air path and the second air path are independent paths within the holder, and the independent structure may be such that one of the first air path and the second air path is a path that includes a radial path passing radially between the rotating shaft and the fixed part, and the other of the first air path and the second air path is a path that does not include the radial path but includes an axial path passing axially through the rotating shaft.

[0017] By including an independent structure, it is possible to avoid air leakage between multiple air paths due to gas traveling through the gap between the rotating shaft and the fixed part, and to suppress pressure changes in the other air path caused by a pressure change in one of the first air path and the second air path.

[0018] (3) In the chip holding device of (2) above, the axial path includes a tube that passes through a hollow region of the rotating shaft having a hollow structure and has one end connected to the attachment, the restraining structure includes a bearing structure connected to the other end of the tube, and the bearing structure may rotate in a direction that eliminates the twist of the tube which rotates on one side around the shaft as the attachment rotates on one side around the shaft by the rotating shaft.

[0019] By including a bearing structure, deterioration of the tube due to twisting is suppressed, and the frequency of tube replacement can be reduced.

[0020] (4) In the chip holding device of (2) or (3) above, the first air path may include the radial path, and the second air path may not include the radial path but may include the axial path.

[0021] By designing the second air path through which pressurized air passes to include an axial path but omit a radial path, it is possible to avoid the pressurized air pressing radially against the rotating shaft and causing the rotating shaft to temporarily become eccentric with respect to the centerline. This prevents misalignment of attachments and tips caused by the eccentricity of the rotating shaft.

[0022] (5) In the chip holding device of (1) to (4) above, the first air path includes a first radial path passing radially between the rotating shaft and the fixed part, the second air path includes a second radial path passing radially between the rotating shaft and the fixed part at a position axially different from the first radial path, and the suppression structure may include a suppression member provided in the axial direction between the first radial path and the second radial path, which suppresses radial movement of the rotating shaft in a region including at least the first radial path when the rotating shaft is pressed radially by the gas passing through the second radial path.

[0023] Since the suppression member restricts radial movement in the rotating shaft, it is possible to suppress misalignment of attachments and tips caused by eccentricity of the rotating shaft.

[0024] (6) In the chip holding device of (5) above, the rotating shaft is divided in the axial direction into a first rotating shaft including the first radial path and a second rotating shaft including the second radial path, and the suppressing member may include an absorbing member provided between the first rotating shaft and the second rotating shaft that absorbs the pressing force on the second rotating shaft by gas passing through the second radial path through elastic deformation.

[0025] The absorbent member absorbs radial impact through elastic deformation, thereby suppressing radial eccentricity of the first rotation axis. This suppresses misalignment of attachments and tips caused by pressure changes when the first rotation axis becomes radially eccentric.

[0026] (7) In the chip holding device described in (5) above, the restraining member may include a support member provided between the rotating shaft and the fixed portion, which supports the rotating shaft that is pressed radially by the gas passing through the second radial path.

[0027] By supporting the space between the first radial path and the second radial path with a support member, the radial movement of the rotation axis is restricted, making it less likely for the rotation axis to become eccentric. As a result, it is less likely for a gap that could cause air leakage to form between the rotation axis and the fixed part, thus suppressing the effect of pressure changes in one of the first and second air paths on the other path.

[0028] <Details of Embodiments of the Invention> The details of embodiments of the present invention will be described below.

[0029] [Outline Configuration of Chip Holding Device 1] Figure 1 is a schematic diagram illustrating a chip holding device 1 according to an embodiment. The chip holding device 1 comprises a holder 2, an attachment 3, and a collet 4. The chip holding device 1 is a device that, for example, inside a semiconductor manufacturing apparatus, holds a chip 11 (Figure 2) and changes the orientation of the chip 11 as appropriate or transports the chip 11 to another location. The chip holding device 1 is fixed to a housing H1 inside the semiconductor manufacturing apparatus by arms A1, A2, and A3, for example.

[0030] The holder 2 includes a rotating shaft 21, a fixed part 22, a plurality (for example, two) of bearings 23, 24, a plurality (for example, two) of seals 25, 26, a first air passage 5, a second air passage 6, a suppression structure 7, and a drive unit M1.

[0031] The rotating shaft 21 is an axial member that rotates around the axis of the center line C1. In the following description, the direction along the center line C1 is the axial direction of the holder 2, and is simply referred to as the "axial direction". The axial direction also includes the direction parallel to the center line C1 (the up and down direction in Figure 1). The lower side of Figure 1 (the collet 4 side) is defined as "one side" of the axial direction, and the upper side of Figure 1 is defined as "the other side" of the axial direction. The direction perpendicular to the center line C1 is the radial direction of the holder 2, and is simply referred to as the "radial direction". The direction in which the rotating shaft 21 rotates around the center line C1 is the circumferential direction of the holder 2, and is simply referred to as the "circumferential direction".

[0032] The rotating shaft 21 has a hollow structure 21a along the center line C1. That is, the rotating shaft 21 is annular rather than cylindrical in at least a portion of its axial direction. The hollow structure 21a is an inner circumferential surface formed inside the rotating shaft 21, and a hollow region is formed inside the hollow structure 21a. The tube 63, described later, passes through this hollow region.

[0033] The fixing portion 22 is an annular member that fixes the rotating shaft 21 to the housing H1. A bearing 23 is fitted to the inner circumferential surface of the other axial end of the fixing portion 22, and a bearing 24 is fitted to the inner circumferential surface of the one axial end of the fixing portion 22. These bearings 23 and 24 allow the fixing portion 22 to hold the rotating shaft 21 so that it can rotate around the axis of the center line C1. The outer circumferential surface of the fixing portion 22 is fixed to the housing H1 via the arm A1.

[0034] The multiple bearings 23 and 24 are, for example, ball bearings. These bearings 23 and 24 only need to be components that rotatably hold the rotating shaft 21 around its axis, and may be other types of bearings, such as sliding bearings.

[0035] The multiple seals 25 and 26 are, for example, resin O-rings. These seals 25 and 26 seal the space between the rotating shaft 21 and the stationary part 22. Seal 25 is provided in the axial direction between the bearing 23 and the first air passage 5 (specifically, the radial passage 53 described later). Seal 26 is provided in the axial direction between the bearing 24 and the first air passage 5. By providing these seals 25 and 26, it is possible to suppress gas passing through the first air passage 5 from leaking out of the holder 2 through the gap between the rotating shaft 21 and the stationary part 22, and to suppress air from outside the holder 2 from entering the first air passage 5 through the gap. In addition to these seals 25 and 26, the tip holding device 1 may also be provided with seals such as O-rings at appropriate positions.

[0036] The first air path 5 is a path through which gas (also called "negative pressure air") is passed for vacuum adsorption of the attachment 3 to the rotating shaft 21. The first air path 5 includes a first region 51 that passes through the fixed portion 22 and a second region 52 that passes through the rotating shaft 21. The first region 51 is formed by a hole that penetrates the fixed portion 22 radially. The second region 52 includes a radial path 53 that passes through the rotating shaft 21 radially and an axial path 54 that passes through the rotating shaft 21 axially.

[0037] One end of the radial path 53 opens onto the outer circumferential surface of the rotating shaft 21 and communicates with the first region 51. Regardless of the rotation angle of the rotating shaft 21 with respect to the fixed portion 22, the radial path 53 is provided as a groove around the entire circumference of the outer circumferential surface of the rotating shaft 21 so that it communicates with the first region 51.

[0038] The other end of the radial path 53 communicates with one end of the axial path 54. The other end of the axial path 54 opens to the end face 21b (the lower surface in Figure 1) on one axial side of the rotating shaft 21. The first air path 5 is connected to a pump (not shown) outside the holder 2. The operation of the pump creates negative pressure in the first air path 5, and the attachment 3 is vacuum-adsorbed at the opening at the other end of the axial path 54.

[0039] The second air path 6 is a path through which at least one of the following passes: a gas (negative pressure air) for vacuum adsorption of the tip 11 to the collet 4, and a gas (also called "pressurized air" or "compressed air") for releasing the vacuum adsorption between the collet 4 and the tip 11. The second air path 6 is provided to penetrate the holder 2 in the axial direction.

[0040] More specifically, the second air path 6 includes an axial path 61 that passes axially through the rotating shaft 21 along the center line C1, an axial path 62 that connects to the rotating side of the bearing structure 72 described later, an axial path 65 that connects to the stationary side of the bearing structure 72, an axial path 33 that passes axially through the attachment 3, and an axial path 43 that passes axially through the collet 4. The second air path 6 communicates in the order of axial paths 65, 62, 61, 33, and 43 from the other axial side, and opens to one axial side at the end face 42 of the collet 4.

[0041] The axial paths 61 and 62 include a resin tube 63. One end of the tube 63 on one axial side is connected to a joint J1, and the other end of the tube 63 on the other axial side is connected to a joint J2. The joint J1 is fixed to the rotating shaft 21, and one end 64 of the joint J1 on one axial side is connected to the attachment 3 at the end face 21b. The joint J2 is connected to the rotating side of the bearing structure 72, which will be described later.

[0042] The second air passage 6 is connected to a pump (not shown) outside the holder 2. The pump appropriately performs a suction operation to draw gas from the second air passage 6 and a pumping operation to pressurize and send gas into the second air passage 6. The suction operation of the pump creates negative pressure in the second air passage 6, and the tip 11 is vacuum-adsorbed at the end face 42 of the collet 4. Then, when the pump performs a pumping operation while the tip 11 is vacuum-adsorbed at the end face 42, the pressure in the second air passage 6 increases, and the vacuum adsorption of the tip 11 is released.

[0043] The suppression structure 7 is a structure that suppresses the occurrence of a pressure change in the other air path due to a pressure change in one of the first air path 5 and the second air path 6. Details of the suppression structure 7 will be described later.

[0044] The drive unit M1 is a drive source that rotates the rotary shaft 21 around its axis. The drive unit M1 is, for example, a direct drive motor (DD motor) connected to the rotary shaft 21. The drive unit M1 rotates around its axis in response to an operation command from a control unit (not shown) to rotate the rotary shaft 21 around its axis. Specifically, the drive unit M1 includes a rotary shaft M1a and a fixed part M1b. The rotary shaft M1a is a part that rotates around its axis with respect to the fixed part M1b and is fixed to the rotary shaft 21. The fixed part M1b is fixed to the housing H1 via the arm A3.

[0045] The attachment 3 is a replacement member that is detachably attached to the rotary shaft 21. The attachment 3 is integrated with the collet 4, and by replacing the attachment 3, the collet 4 is replaced. The attachment 3 includes an end face 31 on the other axial side that contacts the rotary shaft 21 and an end face 32 on one axial side that contacts the collet 4. The axial path 33 opens to these end faces 31 and 32, respectively.

[0046] The collet 4 is a resin-made holding member provided on the attachment 3. The collet 4 includes an end face 41 on the other axial side that contacts the attachment 3 and an end face 42 on one axial side that contacts the chip 11. The axial path 43 opens to these end faces 41 and 42, respectively. At least the material near the end face 42 of the collet 4 is made of an elastic rubber material to be in close contact with the chip 11 to be picked up.

[0047] [Example of operation of the chip holding device 1] FIG. 2 is a schematic diagram illustrating a state in which the chip 11 is held by the chip holding device 1. For example, a plurality of chips 11 such as semiconductor elements are formed by cutting a semiconductor wafer adhered on a dicing tape 12.

[0048] In the chip pickup operation, first, as shown in FIG. 2(a), the needle 13 and the collet 4 are aligned with the chip 11 to be picked up among the plurality of chips 11.

[0049] Next, as shown in Figure 2(b), the needle 13 pushes up the tip 11 from the dicing tape 12 side, and as shown in Figure 2(c), the tip 11 is brought into close contact with the collet 4. In this state, the pump connected to the second air path 6 is activated to create a suction, causing the tip 11 to be vacuum-adsorbed to the collet 4.

[0050] Subsequently, as shown in Figure 2(d), the needle 13 moves back to its original position as shown in Figure 2(a), causing the tip 11 to detach from the dicing tape 12 and be picked up by the collet 4.

[0051] [Problems Solved by Chip Holding Device 1] Figure 6 is a schematic diagram illustrating the problems that Chip Holding Device 1 solves. As described in "Problems to be Solved by the Invention" in this specification, when a chip holding device employs a configuration that uses permanent magnetism to hold the attachment in the holder, problems such as misalignment of the attachment and particle generation occur. To solve these problems, the inventors first invented the chip holding device 9 shown in Figure 6, which is a chip holding device that attaches the attachment to the holder by vacuum suction.

[0052] The chip holding device 9 comprises a holder 91, an attachment 92, and a collet 93. The configuration of the attachment 92 and the collet 93 is the same as that of the attachment 3 and the collet 4 in this embodiment, so a description is omitted.

[0053] The holder 91 includes a rotating shaft 911 that rotates around the axis of the center line C1, a fixing part 912 that fixes the rotating shaft 911 to the housing, a plurality of bearings 913, 914 that rotatably hold the rotating shaft 911, an air path 94 for adsorbing and holding the attachment 92, and an air path 95 for adsorbing and holding the tip at the tip of the collet 93.

[0054] The air path 94 includes a first region 941 that passes through the fixed portion 912 and a second region 942 that passes through the rotating shaft 911. The first region 941 is formed by a hole that penetrates the fixed portion 912 radially.

[0055] One end 943 of the second region 942 opens onto the outer circumferential surface of the rotating shaft 911 and communicates with the first region 941. Regardless of the rotation angle of the rotating shaft 911 relative to the fixed portion 912, the one end 943 of the radial path is provided in a groove shape around the entire circumference of the outer circumferential surface of the rotating shaft 911 so that the first region 941 and the second region 942 can communicate.

[0056] The other end 944 of the second region 942 opens to the end face (the lower surface in Figure 6) on one axial side of the rotating shaft 911. The air path 94 is connected to a pump (not shown) outside the holder 91. The operation of the pump creates negative pressure in the air path 94, and the attachment 92 is vacuum-suctioned at the opening at the other end 944.

[0057] The air path 95 includes a first region 951 that passes through the fixed portion 912 and a second region 952 that passes through the rotating shaft 911. The first region 951 is formed by a hole that penetrates the fixed portion 912 radially.

[0058] One end 953 of the second region 952 opens onto the outer circumferential surface of the rotating shaft 911 and communicates with the first region 951. Regardless of the rotation angle of the rotating shaft 911 relative to the fixed portion 912, the one end 953 of the radial path is provided in the shape of a groove around the entire circumference of the outer circumferential surface of the rotating shaft 911 so that the first region 951 and the second region 952 can communicate.

[0059] The other end 954 of the second region 952 opens to the end face on one axial side of the rotating shaft 911 and communicates with the axial through hole 921 in the attachment 92 and the axial through hole 931 in the collet 93, respectively. The air path 95 is connected to a pump (not shown) outside the holder 91. The operation of the pump creates a negative or pressurized state in the air path 95, causing the tip to be vacuum-adsorbed or released at the tip of the collet 93 (opening of the through hole 931).

[0060] As described above, the chip holding device 9 vacuum-adsorbs the attachment 92 to the holder 91 via the air path 94 and vacuum-adsorbs the chip to the collet 93 via the air path 95. By using this method of vacuum-adsorbing the attachment 92 to the holder 91, the attachment 92 is in contact with the holder 91 when vacuum-adsorbed, thereby reducing the risk of misalignment and particle generation compared to the magnetic attraction method.

[0061] On the other hand, when the tip is vacuum-adsorbed to the collet 93, pressurized air may be passed through the air path 95 in order to remove the tip from the collet 93. In this case, since the tip holding device 9 has multiple air paths 94 and 95 in the holder 91, there is a risk that the pressurized air flowing from the first region 951 to the second region 952 of the air path 95 may leak into the air path 94 through the gap between the rotating shaft 911 and the fixed part 912, as shown by arrow AR1 in Figure 6. If pressurized air from the air path 95 leaks into the air path 94, a pressure change will occur in the air path 94 (specifically, a decrease in the suction pressure of the attachment 92), which may cause adverse effects such as displacement or detachment of the attachment 92 from the holder 91.

[0062] Furthermore, when pressurized air is passed through the air path 95, the air pressure may temporarily cause the rotating shaft 911 to become radially eccentric, and the pressure changes resulting from this eccentricity may cause misalignment of the attachment 92 or the tip.

[0063] Furthermore, if negative pressure air passing through the air path 94 causes pressure changes in the air path 95, adverse effects such as chip damage may occur. For example, in order to hold an attachment 92 that is heavier than the chip by suction, the negative pressure in the air path 94 is set to be stronger than the negative pressure in the air path 95. If such strong negative pressure is transmitted through the gap between the rotating shaft 911 and the fixed part 912 to the air path 95, the chip will be subjected to a negative pressure stronger than the negative pressure suitable for holding the chip by suction, which may cause problems such as chip deformation.

[0064] Therefore, the inventors invented a chip holder 1, which is an improved version of the chip holder 9. As described below, the chip holder 1 includes a suppression structure 7 that suppresses pressure changes in one of the multiple air paths 5 and 6 caused by a pressure change in the other air path, thus solving the above problem. The suppression structure 7 will be described below.

[0065] [Regarding the suppression structure 7] Refer to Figure 1. The suppression structure 7 includes an independent structure 71 and a bearing structure 72.

[0066] The independent structure 71 is a structure in which the first air path 5 and the second air path 6 are independent paths within the holder 2. Specifically, the independent structure 71 is a structure in which one of the first air path 5 and the second air path 6 is a path that includes a radial path passing radially between the rotating shaft 21 and the fixed part 22, and the other of the first air path 5 and the second air path 6 is a path that does not include the radial path but includes an axial path passing axially through the rotating shaft 21.

[0067] In the example shown in Figure 1, one of the first air paths 5 includes a radial path 53, while the other second air path 6 is provided axially through the holder 2. Therefore, the second air path 6 includes an axial path 61 and does not include a radial path.

[0068] In this way, the first air path 5 and the second air path 6 are made into independent paths such that one includes a radial path and the other does not. This prevents air leakage between air paths 5 and 6 due to gas traveling through the gap between the rotating shaft 21 and the fixed part 22, as shown by arrow AR1 in Figure 6, and suppresses pressure changes in the other air path caused by pressure changes in one of the first air path 5 and the second air path 6. As a result, problems such as displacement of the attachment 3 caused by unexpected pressure changes in the air paths 5 and 6 can be suppressed.

[0069] In particular, in the independent structure 71, of the first air path 5 and the second air path 6, the first air path 5 through which negative pressure air passes includes a radial path 53, while the second air path 6 through which both negative pressure air and pressurized air pass includes an axial path 61 but does not include a radial path. With this configuration, since the pressurized air does not pass through the radial path, i.e., the path through which it is introduced from the fixed part 22 to the rotating shaft 21, it is possible to avoid the pressurized air pressing the rotating shaft 21 radially and causing the rotating shaft 21 to be temporarily eccentric with respect to the center line C1. This makes it possible to avoid misalignment of the attachment 3 and the tip 11 caused by the eccentricity of the rotating shaft 21.

[0070] In addition, the independent structure 71 may be configured such that the second air path 6 includes a radial path, and the first air path 5 includes an axial path but does not include a radial path. In other words, the first air path 5 and the second air path 6 may be swapped in Figure 1. Even in this configuration, air leakage between the air paths 5 and 6 due to gas traveling through the gap between the rotating shaft 21 and the fixed part 22 can be avoided.

[0071] The bearing structure 72 is connected to the other end of the tube 63 on the other axial side. Here, the rotating shaft 21 rotates around the axis of the centerline C1 in order to change the orientation of the tip 11. If an independent structure 71 is provided as described above, and the second air path 6 is a path that includes axial paths 61 and 62, then one end of the axial path 61 is connected to the rotating shaft 21 and the attachment 3 via the joint J1. As a result, the tube 63 constituting the axial paths 61 and 62 twists in the circumferential direction as the rotating shaft 21 rotates. Therefore, deterioration of the tube 63 occurs due to twisting, and as the rotation frequency of the rotating shaft 21 increases, the frequency of tube 63 replacement also increases.

[0072] Therefore, in order to suppress deterioration of the tube 63 due to twisting, the twisting of the tube is eliminated by the bearing structure 72. Specifically, the bearing structure 72 includes a rotating shaft 721 fixed to the outer surface of a joint J2 to which the other end of the tube 63 is connected, and a fixed part 722 fixed to the housing H1 via an arm A2. A bearing 723 is fitted to the inner surface of the rotating shaft 721, which holds the rotating shaft 721 so as to be rotatable around the axis of the center line C1. The bearing 723 and the fixed part 722 are connected by a joint J3 fitted to their respective inner surfaces. As a result, the inner ring of the bearing 723 is a fixed ring, and the outer ring is a rotating ring.

[0073] The axial path 65 is composed of a separate tube from tube 63. The tubes constituting the axial path 65 are connected to the fixed part 722 by a joint J4. In other words, in the second air path 6, tube 63 is located on one axial side of joint J2, and a tube different from tube 63 is located on the other axial side of joint J4.

[0074] The rotating shaft 21 of the holder 2 is a shaft whose rotation is controlled by the drive unit M1, while the rotating shaft 721 is not connected to a drive unit such as a motor and is provided to rotate freely in the circumferential direction relative to the fixed part 722. The bearing structure 72 (specifically, the rotating shaft 721) rotates in a direction (likewise clockwise) that eliminates the twist of the tube 63 which rotates in one direction around the shaft as the attachment 3 rotates in one direction around the shaft (for example clockwise) by the rotating shaft 21.

[0075] In other words, as the tube 63 rotates, the joint J2, the rotating shaft 721, and the outer ring of the bearing 723 (these parts are also referred to as the "rotating side of the bearing structure 72") rotate, eliminating the twist of the tube 63. At this time, the inner ring of the bearing 723, the joint J3, the fixed part 722, and the joint J4 (these parts are also referred to as the "fixed side of the bearing structure 72") do not rotate in the circumferential direction while fixed to the arm A2, and therefore the axial path 65 also does not rotate.

[0076] In this manner, since the rotating shaft 721 rotatably holds the other end of the tube 63, if twisting occurs in the tube 63, the rotation according to the restoring force of the tube 63 itself can eliminate the twisting. Therefore, deterioration of the tube 63 due to twisting is suppressed, and the frequency of replacement of the tube 63 can be reduced.

[0077] The chip holding device 1 may include an independent structure 71 as a restraining structure 7, but may not include a bearing structure 72. For example, if a tube 63 that is resistant to deterioration due to twisting is used, the need to eliminate twisting decreases. For this reason, the bearing structure 72 may be omitted. Also, if the tube 63 is replaced frequently for other reasons, a certain degree of deterioration of the tube 63 due to twisting is acceptable, so the bearing structure 72 may be omitted.

[0078] [Modifications] Modifications of the embodiments are described below. In the modifications, the same reference numerals are used for components that are the same as in the embodiments, and their descriptions are omitted.

[0079] [First Modified Example of the Suppression Structure] In the above embodiment, the suppression structure 7 includes an independent structure 71 in which the first air path 5 and the second air path 6 are each independent paths within the holder 2. However, the suppression structure 7 is not limited to this. In this modified example, another example of the suppression structure 7 will be described.

[0080] Figure 3 is a schematic diagram showing a chip holding device 1a according to the first modified example. The chip holding device 1a comprises a holder 2a, an attachment 3, and a collet 4. The holder 2a, like the holder 2, is a member that holds the attachment 3 so that it can rotate around the axis of the center line C1 while the attachment 3 is attached by vacuum suction.

[0081] The holder 2a includes a rotating shaft 210 that rotates around the axis of the center line C1, fixing parts 220 that fix the rotating shaft 210 to the housing H1 via a plurality of arms A1, A3, a plurality of bearings 231, 232, 241, 242 that rotatably hold the rotating shaft 210, a plurality of seals 251, 252, 261, 262, a first air path 50 for adsorbing and holding the attachment 3, a second air path 60 for adsorbing and holding the tip 11 at the tip of the collet 4, a suppression structure 7, and a drive unit M1.

[0082] The rotating shaft 210 is divided in the axial direction into a first rotating shaft 211 and a second rotating shaft 212. The first rotating shaft 211 is located on one axial side of the second rotating shaft 212 and holds the attachment 3 by suction at the end face 211b (the lower surface in Figure 3) on one axial side of the first rotating shaft 211. An absorbent member 73, which will be described later, is provided between the first rotating shaft 211 and the second rotating shaft 212.

[0083] The fixing portion 220 is divided in the axial direction into a first fixing portion 221 and a second fixing portion 222. The first fixing portion 221 is located on one axial side of the second fixing portion 222 and is an annular member that fixes the first rotating shaft 211 to the housing H1. A bearing 231 is fitted to the inner circumferential surface of the other axial end of the first fixing portion 221, and a bearing 241 is fitted to the inner circumferential surface of the other axial end of the first fixing portion 221. These bearings 231 and 241 allow the first fixing portion 221 to hold the first rotating shaft 211 so that it can rotate around the axis of the center line C1. The outer circumferential surface of the first fixing portion 221 is fixed to the housing H1 via an arm A1.

[0084] The second fixing portion 222 is an annular member that fixes the second rotating shaft 212 to the housing H1. A bearing 232 is fitted to the inner circumferential surface of the other axial end of the second fixing portion 222, and a bearing 242 is fitted to the inner circumferential surface of the one axial end of the second fixing portion 222. These bearings 232 and 242 allow the second fixing portion 222 to hold the second rotating shaft 212 so that it can rotate around the axis of the center line C1. The outer circumferential surface of the second fixing portion 222 is fixed to the housing H1 via an arm A4.

[0085] The multiple bearings 231, 232, 241, and 242 are, for example, ball bearings. These bearings 231, 232, 241, and 242 only need to be members that rotatably hold the first rotating shaft 211 and the second rotating shaft 212 around their axes, and may be other types of bearings, such as sliding bearings.

[0086] The multiple seals 251, 252, 261, and 262 are, for example, resin O-rings. These seals 251, 252, 261, and 262 seal the space between the rotating shaft 210 and the stationary part 220. Seal 251 is provided in the axial direction between the bearing 231 and the first air path 50 (specifically, the radial path 531 described later). Seal 261 is provided in the axial direction between the bearing 241 and the first air path 50. Seal 252 is provided in the axial direction between the bearing 232 and the second air path 60 (specifically, the radial path 603 described later). Seal 262 is provided in the axial direction between the bearing 242 and the second air path 60.

[0087] The first air path 50 includes a first region 511 passing through the first fixed portion 221 and a second region 521 passing through the first rotating shaft 211. The first region 511 is formed by a hole that penetrates the first fixed portion 221 radially. The second region 521 includes a first radial path 531 passing through the first rotating shaft 211 radially and a first axial path 541 passing through the first rotating shaft 211 axially.

[0088] One end of the first radial path 531 opens onto the outer circumferential surface of the first rotating shaft 211 and communicates with the first region 511. Regardless of the rotation angle of the first rotating shaft 211 with respect to the first fixed portion 221, one end of the first radial path 531 is provided as a groove along the entire circumference of the outer circumferential surface of the first rotating shaft 211 so that the first radial path 531 and the first region 511 communicate with each other.

[0089] The other end of the first radial path 531 communicates with one end of the first axial path 541. The other end of the first axial path 541 opens to the end face 211b (the lower surface in Figure 1) on one axial side of the first rotating shaft 211. The first air path 50 is connected to a pump (not shown) outside the holder 2a. The operation of the pump creates negative pressure in the first air path 50, and the attachment 3 is vacuum-adsorbed at the opening at the other end of the first axial path 541.

[0090] The second air path 60 is a path through which at least one of the following passes: a gas (negative pressure air) for vacuum adsorption of the tip 11 to the collet 4, and a gas (pressurized air) for releasing the vacuum adsorption between the collet 4 and the tip 11.

[0091] The second air path 60 includes a first region 601 that passes through the second fixed portion 222, and a second region 602 that passes through the first rotating shaft 211, the absorbing member 73, and the second rotating shaft 212. The first region 601 is formed by a hole that penetrates the second fixed portion 222 in the radial direction.

[0092] The second region 602 includes a second radial path 603 passing radially through the second rotation axis 212, a second axial path 604 passing axially through the second rotation axis 212, a third axial path 605 passing axially through the absorbing member 73, and a fourth axial path 606 passing axially through the first rotation axis 211.

[0093] One end of the second radial path 603 opens onto the outer circumferential surface of the second rotating shaft 212 and communicates with the first region 601. Regardless of the rotation angle of the second rotating shaft 212 with respect to the second fixed portion 222, one end of the second radial path 603 is provided as a groove around the entire circumference of the outer circumferential surface of the second rotating shaft 212 so that the second radial path 603 and the first region 601 can communicate.

[0094] The other end of the second radial path 603 communicates with one end of the second axial path 604. The second axial path 604, the third axial path 605, and the fourth axial path 606 communicate in this order along the center line C1, starting from one side in the axial direction. The other end of the fourth axial path 606 opens onto the end face 211b (the lower surface in Figure 3) on one side in the axial direction of the first rotation axis 211. The fourth axial path 606 then communicates with the axial path 33 that passes through the attachment 3 in the axial direction and the axial path 43 that passes through the collet 4 in the axial direction.

[0095] The second air passage 60 is connected to a pump (not shown) outside the holder 2a. The pump appropriately performs a suction operation to draw gas from the second air passage 60 and a pumping operation to pressurize and send gas into the second air passage 60. The suction operation of the pump creates negative pressure in the second air passage 60, and the tip 11 is vacuum-adsorbed at the end face 42 of the collet 4. Then, when the pump performs a pumping operation while the tip 11 is vacuum-adsorbed at the end face 42, the pressure in the second air passage 60 increases, and the vacuum adsorption of the tip 11 is released.

[0096] Thus, the first air path 50 includes a first radial path 531 that passes radially between the rotating shaft 210 and the fixed part 220, and the second air path 60 includes a second radial path 603 that passes radially between the rotating shaft 210 and the fixed part 220 at a position axially different from that of the first radial path 531.

[0097] The suppression structure 7 of this modified example includes a suppression member. The suppression member is provided in the axial direction between the first radial path 531 and the second radial path 603, and is a member that suppresses the radial movement of at least the region of the rotating shaft 210 that includes the first radial path 531 (specifically, the first rotating shaft 211) when the rotating shaft 210 (specifically, the second rotating shaft 212) is pressed radially by gas passing through the second radial path 603.

[0098] More specifically, the suppression member is provided between the first rotating shaft 211 and the second rotating shaft 212 and includes an absorbing member 73 that absorbs the pressing force on the second rotating shaft 212 by gas passing through the second radial path 603 due to elastic deformation.

[0099] The absorbent member 73 is an annular member, and connects the first rotating shaft 211 and the second rotating shaft 212 by fitting the outer surface of the first rotating shaft 211 to the inner circumference of one end on the axial side and fitting the outer surface of the second rotating shaft 212 to the inner circumference of the other end on the axial side.

[0100] The absorbent member 73 includes a frame 731 and an elastic member 732. The frame 731 is an annular region provided at both axial ends of the absorbent member 73 and fitted onto the first rotation axis 211 and the second rotation axis 212, respectively. The frame 731 is a metal member, such as stainless steel, and has higher rigidity than the elastic member 732.

[0101] The elastic member 732 is an annular member located between the frames 731 in the axial direction. The elastic member 732 is made of synthetic rubber such as butadiene rubber or ethylene propylene rubber, and absorbs radial and axial impacts.

[0102] The drive unit M1 is a drive source that rotates the first rotating shaft 211 around its axis. When the first rotating shaft 211 is rotated around its axis by the drive unit M1, the absorbing member 73 and the second rotating shaft 212 also rotate together with the first rotating shaft 211.

[0103] Thus, in the chip holding device 1a, an absorbent member 73 is provided between the first radial path 531 and the second radial path 603 in the axial direction. For example, when pressurized air is passed through the second air path 60 to release the vacuum adsorption of the chip 11 in the collet 4, the air pressure of the pressurized air may cause the second rotation axis 212 to temporarily become eccentric in the radial direction.

[0104] In this modified example, even when such eccentricity occurs, the absorbing member 73 (specifically, the elastic member 732) absorbs the radial impact through elastic deformation, thereby suppressing radial eccentricity of the first rotating shaft 211. This makes it possible to suppress displacement of the attachment 3 and tip 11 caused by pressure changes when the first rotating shaft 211 becomes radially eccentric.

[0105] Furthermore, in the chip holding device 1a, the first radial path 531 of the first air path 50 is provided on the first rotating shaft 211, and the second radial path 603 of the second air path 60 is provided on the second rotating shaft 212, with the first rotating shaft 211 and the second rotating shaft 212 being separated as separate components in the axial direction. As a result, air leakage as shown by arrow AR1 in Figure 6 does not occur between the first radial path 531 and the second radial path 603, and pressure changes in one path can suppress their influence on the other.

[0106] In other words, in the chip holding device 1a, the path where air leakage occurs in the first radial path 531 (between the first rotating shaft 211 and the first fixed part 221) and the path where air leakage occurs in the second radial path 603 (between the second rotating shaft 212 and the second fixed part 222) are not connected and are interrupted midway. In this modified example, a structure in which the first radial path 531 is provided on the first rotating shaft 211 and the second radial path 603 is provided on the second rotating shaft 212, which is a member independent of the first rotating shaft 211, is also included in the suppression structure 7.

[0107] [Second Modification of the Suppression Structure] In the above embodiment and the first modification, there were two air passages passing through the holders 2 and 2a. However, the number of air passages may be greater. In this modification, a chip holding device 1b including three air passages will be described.

[0108] Figure 4 is a schematic diagram showing a chip holding device 1b according to a second modified example. The chip holding device 1b is a form obtained by appropriately combining the chip holding device 1 and the chip holding device 1a described above, and includes an independent structure 71, a bearing structure 72, and an absorbent member 73 (suppression member) as a suppression structure 7.

[0109] The chip holder 1b differs from the chip holder 1a mainly in that it further includes a second air path 6 and a bearing structure 72, and includes a collet 4a instead of a collet 4. Specifically, the holder 2b comprises a first rotating shaft 211, a second rotating shaft 212, a first fixing part 221, and a second fixing part 222, which are divided in the axial direction.

[0110] The first rotating shaft 211 has a hollow structure 211a along the center line C1. The hollow structure 211a is an inner circumferential surface formed inside the first rotating shaft 211, and a hollow region is formed inside the hollow structure 211a. The second rotating shaft 212 also has a hollow structure 212a along the center line C1. The hollow structure 212a is an inner circumferential surface formed inside the second rotating shaft 212, and a hollow region is also formed inside the hollow structure 212a. Tubes 63, which constitute the second air path 6, are passed through these hollow regions.

[0111] The first air passage 50 and the second air passage 60 are both routed through the holder 2b, similar to the first modified example (Figure 3). Unlike the above modified example, the second air passage 60 has an axial passage 607 that extends axially and penetrates the attachment 3 in the axial direction, opening at one end face 32 on the axial side of the attachment 3.

[0112] The collet 4a is a rectangular parallelepiped-shaped retaining member formed from a porous material. The end face 42a on one axial side of the collet 4a is provided in a planar shape with a larger area than the end face 42 of the collet 4.

[0113] The chip holding device 1b includes three air paths: a first air path 50, a second air path 60, and a second air path 6. The first air path 50 is a path through which negative pressure air is passed to vacuum-suction the attachment 3 to the holder 2b.

[0114] The second air path 60 and the second air path 6 are paths for non-contact chucking of the tip 11 by the collet 4a. Specifically, the second air path 6 is a path through which negative pressure air passes to the collet 4a for vacuum suction of the tip 11. This negative pressure air attracts the tip 11 to the collet 4a. The second air path 60 is a path through which pressurized air passes to the porous collet 4a. This pressurized air is blown out in one axial direction (towards the tip 11) from a plurality of holes provided on the end face 42a of the collet 4a, thereby subjecting the tip 11 to a force moving away from the collet 4a. By appropriately adjusting the balance between the negative pressure air in the second air path 6 and the pressurized air in the second air path 60, the tip 11 can be held near the end face 42a in a non-contact state with the end face 42a.

[0115] Furthermore, the uses of the first air path 50, the second air path 60, and the second air path 6 may be in combinations other than those described above. For example, pressurized air may be passed through the second air path 60 and negative pressure air through the second air path 6. Also, similar to the above embodiment and the first modification, only two of the first air path 50, the second air path 60, and the second air path 6 may be used for vacuum suction of the attachment 3 and vacuum suction of the tip 11, and the remaining path may be used for other purposes.

[0116] As described above, the first air path 50 and the second air path 60 include radial paths 531 and 603, while the second air path 6 has an independent structure 71 that does not include radial paths. Therefore, pressure changes in the second air path 6 can suppress pressure changes in the first air path 50 and the second air path 60. In addition, the twisting of the tube 63 that occurs when an independent structure 71 is adopted can be eliminated by the bearing structure 72.

[0117] Furthermore, in the axial direction, the radial path of the first air path 50 (first radial path 531) and the radial path of the second air path 60 (second radial path 603) are separately provided on the first rotation axis 211 and the second rotation axis 212, respectively, and the absorbing member 73 is positioned between these axes 211 and 212. Therefore, even between the first air path 50 and the second air path 60, it is possible to suppress the influence of pressure changes in one path on the other.

[0118] Thus, when the chip holding device 1b includes three air paths, a first air path 50, a second air path 60, and a second air path 6, the suppression structure 7 includes an independent structure 71, a bearing structure 72, and an absorption member 73. This suppresses the effect of pressure changes in one air path on the other, thereby suppressing malfunctions caused by unexpected pressure changes in the air paths.

[0119] [Third Modification of the Suppression Structure] In the first and second modifications described above, a suppression member was given as an example of the suppression structure 7, and an absorption member 73 was described as a specific example thereof. However, the suppression member is not limited to this. In this modification, another example of the suppression member will be described.

[0120] Figure 5 is a schematic diagram showing a chip holding device 1c according to a third modified example. The chip holding device 1c comprises a holder 2c, an attachment 3, and a collet 4. The holder 2c, like the holder 2, is a member that holds the attachment 3 so that it can rotate around the axis of the center line C1 while the attachment 3 is attached by vacuum suction.

[0121] The holder 2c includes a rotating shaft 213 that rotates around the axis of the center line C1, a fixing part 223 that fixes the rotating shaft 213 to the housing H1 via the arm A1, a plurality of bearings 23, 24 that rotatably hold the rotating shaft 213, a plurality of seals 25, 26, 27, 28, a first air path 5 for adsorbing and holding the attachment 3, a second air path 8 for adsorbing and holding the tip 11 at the tip of the collet 4, a suppression structure 7, and a drive unit M1.

[0122] The first air path 5 is a path through which gas is passed for vacuum adsorption of the attachment 3 to the holder 2c, similar to the embodiment described above. The first air path 5 includes a first region 51 that passes through the fixed portion 223 and a second region 52 that passes through the rotating shaft 213. The second region 52 includes a radial path 53 (hereinafter referred to as the "first radial path 53" in this modified example) that passes radially through the rotating shaft 213 and an axial path 54 that passes axially through the rotating shaft 213.

[0123] The second air path 8 is a path through which at least one of the following passes: a gas (negative pressure air) for vacuum adsorption of the tip 11 to the collet 4, and a gas (pressurized air) for releasing the vacuum adsorption between the collet 4 and the tip 11.

[0124] The second air path 8 includes a first region 81 that passes through the fixed portion 223 and a second region 82 that passes through the rotating shaft 213. The first region 81 is formed by a hole that penetrates the fixed portion 223 radially.

[0125] The second region 82 includes a second radial path 83 passing radially through the rotation axis 213 and an axial path 84 passing axially through the rotation axis 213.

[0126] One end of the second radial path 83 opens onto the outer circumferential surface of the rotating shaft 213 and communicates with the first region 81. Regardless of the rotation angle of the rotating shaft 213 with respect to the fixed portion 223, one end of the second radial path 83 is provided as a groove around the entire circumference of the outer circumferential surface of the rotating shaft 213 so that the second radial path 83 and the first region 81 can communicate.

[0127] The other end of the second radial path 83 communicates with one end of the axial path 84. The axial path 84 extends axially along the center line C1, and the other end of the axial path 84 opens to one end face (the bottom face in Figure 5) of the rotating shaft 213 in the axial direction. The axial path 84 communicates with the axial path 33 that passes through the attachment 3 in the axial direction, and with the axial path 43 that passes through the collet 4 in the axial direction.

[0128] The second air passage 8 is connected to a pump (not shown) outside the holder 2c. The pump appropriately performs a suction operation to draw gas from the second air passage 8 and a pumping operation to pressurize gas into the second air passage 8. The suction operation of the pump creates negative pressure in the second air passage 8, and the tip 11 is vacuum-adsorbed at the end face 42 of the collet 4. Then, when the pump performs a pumping operation while the tip 11 is vacuum-adsorbed at the end face 42, the pressure in the second air passage 8 increases, and the vacuum adsorption of the tip 11 is released.

[0129] Thus, the first air path 5 includes a first radial path 53 that passes radially between the rotating shaft 213 and the fixed part 223, and the second air path 8 includes a second radial path 83 that passes radially between the rotating shaft 213 and the fixed part 223 at a position axially different from that of the first radial path 53.

[0130] The modified suppression structure 7 includes a suppression member. The suppression member is provided in the axial direction between a first radial path 53 and a second radial path 83, and is a member that suppresses radial movement of the rotating shaft 213 in a region of the rotating shaft 213 that includes at least the first radial path 53 when the rotating shaft 213 is pressed radially by gas passing through the second radial path 83.

[0131] More specifically, the suppression member is provided between the rotating shaft 213 and the fixed portion 223 and includes a support member 74 that supports the rotating shaft 213, which is radially pressed by a gas passing through the second radial path 83.

[0132] The support member 74 is a bearing similar to, for example, bearings 23 and 24. The support member 74 is provided in the axial direction between the first radial path 53 and the second radial path 83, and supports the rotating shaft 213 in the radial direction, thereby suppressing radial movement (eccentricity) of the rotating shaft 213 relative to the fixed portion 223.

[0133] In the case of the chip holding device 9 shown in Figure 6, in the axial direction, there is no member to support the rotating shaft 911, such as the support member 74, between the radial air paths 94 and 95. Therefore, eccentricity of the rotating shaft 911 caused by pressurized air, etc., could not be suppressed. In contrast, in this modified example, by supporting the space between the first radial path 53 and the second radial path 83 with the support member 74, the radial movement of the rotating shaft 213 is restricted, making it less likely for the rotating shaft 213 to become eccentric. As a result, it is less likely for a gap that could cause air leakage to form between the rotating shaft 213 and the fixed part 223, and thus it is possible to suppress the effect of pressure changes in one of the first air path 5 and the second air path 8 on the other path. As a result, malfunctions caused by unexpected pressure changes in the air path can be suppressed.

[0134] In the example shown in Figure 5, the support member 74 is shown as a single bearing, but the present invention is not limited to this, and the support member 74 may include multiple bearings to further increase the supporting force. Furthermore, the support member 74 may be realized by elements other than bearings, as long as it is a member that supports the space between the first radial path 53 and the second radial path 83.

[0135] The multiple seals 27 and 28 are, for example, resin O-rings. Seal 27 is provided in the axial direction between the first radial path 53 and the support member 74. Seal 28 is provided in the axial direction between the support member 74 and the second radial path 83. These seals 27 and 28 seal the space between the first radial path 53 and the second radial path 83, so that even if the rotating shaft 213 is slightly eccentric, air leakage between the rotating shaft 213 and the fixed part 223 can be suppressed. This makes it possible to more reliably suppress the effect of pressure changes in one of the first air path 5 and the second air path 8 on the other path.

[0136] [Note] The embodiments and modifications disclosed herein are illustrative and not restrictive in all respects. The technical scope of the present invention is not limited to the embodiments and modifications described above, and includes all modifications within the scope equivalent to the configuration described in the claims.

[0137] 1, 1a, 1b, 1c Tip holder 2, 2a, 2b, 2c Holder 3 Attachment 4, 4a Collet 11 Tip 12 Dicing tape 13 Needle 21, 210, 213 Rotating shaft 211 First rotating shaft 212 Second rotating shaft 21a Hollow structure 22, 220, 223 Fixing part 221 First fixing part 222 Second fixing part 23, 24 Bearing 25, 26 Seal 5, 50 First air path 51, 511 First region 52, 521 Second region 53 Radial path 531 First radial path 54 Axial path 541 First axial path 6, 60, 8 Second air path 61 Axial path 62 Axial path 63 Tube 65 Axial path 603 Second radial path 604 Second axial path 605 Third axial path 606 Fourth axial path 7 Restraint structure 71 Independent structure 72 Bearing structure 721 Rotating shaft 722 Fixed part 723 Bearing 73 Absorbing member 731 Frame 732 Elastic member 74 Support member 9 Tip holding device 91 Holder 92 Attachment 93 Collet 911 Rotating shaft 912 Fixed part 94, 95 Air path A1, A2, A3, A4 Arm H1 Housing M1 Drive unit C1 Centerline J1, J2, J3, J4 Coupling

Claims

1. A tip holding device for holding a tip so that it can rotate around an axis while the tip is vacuum-adsorbed using a collet, comprising: a holder including a rotating shaft that rotates around the axis and a fixing part that fixes the rotating shaft to a housing; an attachment that is detachably attached to the rotating shaft; and the collet provided on the attachment, wherein the holder includes: a first air path for passing a gas for vacuum-adsorbing the attachment to the rotating shaft; a second air path for passing at least one of a gas for vacuum-adsorbing the tip to the collet and a gas for releasing the vacuum adsorption between the collet and the tip; and a suppression structure for suppressing a pressure change in the other air path due to a pressure change in one of the first air path and the second air path.

2. The chip holding device according to claim 1, wherein the suppression structure includes an independent structure in which the first air path and the second air path are independent paths within the holder, and the independent structure is such that one of the first air path and the second air path is a path that includes a radial path passing radially between the rotating shaft and the fixed part, and the other of the first air path and the second air path is a path that does not include the radial path but includes an axial path passing axially through the rotating shaft.

3. The chip holding device according to claim 2, wherein the axial path includes a tube that passes through a hollow region of the rotating shaft having a hollow structure and has one end connected to the attachment, the restraining structure includes a bearing structure connected to the other end of the tube, and the bearing structure rotates in a direction that eliminates the twist of the tube that rotates to one side around the shaft as the attachment rotates to one side around the shaft by the rotating shaft.

4. The chip holding device according to claim 2 or 3, wherein the first air path includes the radial path, and the second air path does not include the radial path but includes the axial path.

5. The chip holding device according to claim 1, wherein the first air path includes a first radial path passing radially between the rotating shaft and the fixed part, the second air path includes a second radial path passing radially between the rotating shaft and the fixed part at a position axially different from that of the first radial path, and the suppression structure includes a suppression member provided axially between the first radial path and the second radial path, which suppresses radial movement of the rotating shaft in a region including at least the first radial path when the rotating shaft is pressed radially by gas passing through the second radial path.

6. The chip holding device according to claim 5, wherein the rotating shaft is divided in the axial direction into a first rotating shaft including the first radial path and a second rotating shaft including the second radial path, and the suppressing member is provided between the first rotating shaft and the second rotating shaft and includes an absorbing member that absorbs the pressing force on the second rotating shaft by gas passing through the second radial path through elastic deformation.

7. The chip holding device according to claim 5, wherein the suppression member includes a support member provided between the rotating shaft and the fixed portion, and supports the rotating shaft which is radially pressed by a gas passing through the second radial path.

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