JP7071182B2 - Shaft unit and plug mechanism - Google Patents

Description

The present invention relates to a shaft unit on which a chuck table is mounted and a plug mechanism that closes an opening at the end of a conduit of the shaft unit.

A chuck table that holds a wafer in a processing apparatus that processes a wafer with a processing tool is mounted on an upper portion of a shaft unit having a rotation mechanism. The shaft unit forms a pipeline inside, and a hole made in the upper surface of the shaft unit is connected to the upper end side of the pipeline, and a hole made in the lower surface of the shaft unit is connected to the lower end side of the pipeline. There is. Then, the hole on the lower surface of the shaft unit is communicated with the suction source, and the suction force generated by the suction source is transmitted to the holding surface (upper surface) of the chuck table mounted on the upper surface of the shaft unit. The wafer is sucked and held on the holding surface.

Further, the pipeline extends from the inside of the shaft unit toward the side surface of the unit and opens on the side surface. Then, the opening on the side surface of the pipeline is closed by a plug. As a plug for closing the opening, a plug for inserting a tapered male screw into a female screw hole formed in the opening portion (see, for example, Patent Document 1) or a plug for driving a steel ball into the opening (for example, a patent). (See Document 2).

Japanese Unexamined Patent Publication No. 2011-256972 Japanese Unexamined Patent Publication No. H10-169882

However, in the case of the embedding as described in Patent Documents 1 and 2, the upper surface of the shaft unit may be inflated. Therefore, it is necessary to flatten the upper surface of the shaft unit after embedding. It becomes a problem.
Therefore, there is a problem that the opening on the side surface of the shaft unit can be closed without inflating the upper surface of the shaft unit.

The present invention for solving the above-mentioned problems includes a plurality of first pores connecting from the upper surface to a pipeline formed from a side surface toward the inside, a second hole connecting to the conduit from a lower surface, and the like. A shaft unit having a plug mechanism for closing an opening on a side surface of a pipeline, wherein the plug mechanism has a female screw hole having an inner diameter larger than the inner diameter of the pipeline toward the inside from the opening, and the conduit and the female. The female screw hole has an O-ring insertion part having an inner diameter smaller than the inner diameter of the female screw hole formed in the connecting portion with the screw hole and a spherical or conical surface on the pipeline side with an outer diameter larger than the inner diameter of the O-ring. The O-ring pressing member capable of advancing and retreating inside and inside the O-ring insertion portion in the extending direction and the push screw screwed into the female screw hole are provided with the push screw screwed into the female screw hole. The O-ring pressing member is pressed against the O-ring inserted into the O-ring insertion portion, and the O-ring is sandwiched between the spherical surface or the conical surface of the O-ring pressing member and the O-ring insertion portion of the O-ring. A shaft unit in which a part of the O-ring pressing member enters the inner diameter to form a seal, close the opening, and form the conduit.

The plug mechanism is further connected to the female screw hole so as to be inward from the female screw hole, and further includes a large-diameter hole having an inner diameter larger than the inner diameter of the pipeline, and the O-ring insertion portion is the conduit and the said. It is preferably formed at the connecting portion with the large diameter hole.

Further, the present invention for solving the above-mentioned problems is a plug mechanism for closing an opening at one end of a pipeline formed so as to go inward from the side surface of the base metal, and the inner diameter of the conduit is formed from the opening toward the inside. An O-ring insertion portion having a larger inner diameter and an inner diameter smaller than the inner diameter of the female screw hole formed in the connecting portion between the pipeline and the female screw hole, and an outer diameter larger than the inner diameter of the O-ring. An O-ring pressing member having a spherical or conical surface on the pipeline side and capable of advancing and retreating in the female screw hole and the O-ring insertion portion in the extending direction, and a push screw screwed into the female screw hole. The O-ring pressing member is pressed against the O-ring inserted into the O-ring insertion portion with the push screw screwed into the female screw hole, and the spherical surface or the conical surface of the O-ring pressing member and the conical surface thereof. It is a plug mechanism in which the O-ring is sandwiched between the O-ring insertion portion and a part of the O-ring pressing member enters the inner diameter of the O-ring to form a seal and close the opening.

The plug mechanism is further connected to the female screw hole so as to be inward from the female screw hole, and further includes a large-diameter hole having an inner diameter larger than the inner diameter of the pipeline, and the O-ring insertion portion is the conduit and the said. It is preferably formed at the connecting portion with the large diameter hole.

The shaft unit according to the present invention has a plurality of first pores connected from the upper surface to the conduit formed from the side surface to the inside, a second hole connected to the conduit from the lower surface, and a side surface of the conduit. It has an O-ring mechanism that closes the opening, and the O-ring mechanism is formed in the female screw hole having an inner diameter larger than the inner diameter of the conduit toward the inside from the opening and the inner diameter of the female screw hole formed at the connecting portion between the conduit and the female screw hole. An O-ring with a smaller inner diameter and an outer diameter larger than the inner diameter of the O-ring , which has a spherical or conical surface on the pipeline side and can move forward and backward in the female screw hole and inside the O-ring insertion part in the extending direction. It is equipped with a pressing member and a push screw to be screwed into the female screw hole, and the O-ring pressing member is pressed against the O-ring inserted into the O-ring insertion part with the push screw screwed into the female screw hole to press the O-ring. The O-ring is sandwiched between the spherical or conical surface of the pressing member or the O-ring insertion portion, and a part of the O-ring pressing member enters the inner diameter of the O-ring to deform the O-ring to form a seal. Since the opening is plugged with the ring pressing member and the push screw, the upper surface of the shaft unit is not inflated. Therefore, it is not necessary to flatten the upper surface of the shaft unit after plugging. Further, since the O-ring, the O-ring pressing member, and the set screw are detachable from the shaft unit, cleaning maintenance in the pipeline can be easily performed. In particular, a force is uniformly applied to the entire circumference of the O-ring by the O-ring insertion portion and the spherical surface or the conical surface of the O-ring pressing member, and the O-ring is sandwiched while being deformed to imitate the spherical surface or the conical surface. Since a part of the O-ring pressing member enters the inner diameter of the O-ring to form a seal, the seal becomes a tighter seal with no gap than before, and leaks occur even if rotational vibration is applied. It will be a seal that will not let you.

The plug mechanism is connected to the female screw hole so as to go inward from the female screw hole, and further has a large-diameter hole having an inner diameter larger than the inner diameter of the pipeline. When the O-ring pressing member is pushed by the push screw and the O-ring is pushed and deformed by the O-ring pressing member, the O-ring pressing member advances straight in the large-diameter hole without rattling. This allows the O-ring and the O-ring pressing member to come into contact with each other without shifting their centers, so that the seal formation can be performed more reliably.

The plug mechanism according to the present invention, which closes the opening at one end of the conduit formed so as to go inward from the side surface of the base material such as the shaft unit, has a female screw hole having an inner diameter larger than the inner diameter of the conduit from the opening to the inside. An O-ring insertion part with an inner diameter smaller than the inner diameter of the female screw hole formed at the connecting portion between the pipeline and the female screw hole, and a female screw having a spherical or conical surface on the pipeline side with an outer diameter larger than the inner diameter of the O-ring. An O-ring pressing member capable of advancing and retreating in the hole and the O-ring insertion portion in the extending direction and an O-ring pressing member screwed into the female screw hole are provided, and the O-ring pressing member is screwed into the female screw hole. Is pressed against the O-ring inserted into the O-ring insertion portion, and the O-ring is sandwiched between the spherical surface or the conical surface of the O-ring pressing member and the O-ring insertion portion, and a part of the O-ring pressing member enters the inner diameter of the O-ring. Since the opening is plugged with the O-ring, the O-ring pressing member, and the push screw in a state where the ring is deformed to form a seal, the upper surface of the base material such as the shaft unit does not swell. Therefore, it is not necessary to flatten the upper surface of the base metal after plugging. Further, since the O-ring, the O-ring pressing member, and the set screw are removable from the shaft unit, it is possible to easily perform cleaning maintenance in the pipeline. In particular, a force is uniformly applied to the entire circumference of the O-ring by the O-ring insertion portion and the spherical surface or the conical surface of the O-ring pressing member, and the O-ring is sandwiched while being deformed to imitate the spherical surface or the conical surface. Since a part of the O-ring pressing member enters the inner diameter of the O-ring to form a seal, the seal becomes a tighter seal with no gap than before, and a seal that does not cause leakage even if rotational vibration is applied. Will be.

The plug mechanism is connected to the female screw hole so as to go inward from the female screw hole, and further has a large-diameter hole having an inner diameter larger than the inner diameter of the pipeline. When the O-ring pressing member is pushed by the push screw and the O-ring is crushed by the O-ring pressing member, the O-ring pressing member can move straight through the large-diameter hole without rattling. As a result, the O-ring and the O-ring pressing member come into contact with each other without shifting their centers, so that the seal formation can be performed more reliably.

It is a vertical sectional view which shows an example of a shaft unit. It is a top view which shows an example of the upper surface of a shaft unit. It is an exploded sectional view of the stopper mechanism provided with a large diameter hole and an O-ring pressing member (steel ball). It is sectional drawing explaining the state which the O-ring pressing member (steel ball) is pressed against the O-ring inserted in the O-ring insertion part by the rotation of a set screw. It is sectional drawing which shows the state which the seal formation of a pipeline is made by the deformed O-ring. It is an exploded sectional view of the plug mechanism provided with a large-diameter hole and another O-ring pressing member. It is sectional drawing explaining the state which the O-ring pressing member of another example is pressed against the O-ring inserted into the O-ring insertion part by the rotation of a set screw. It is sectional drawing which shows the state which the seal formation of a pipeline is made by the O-ring which was pushed and deformed by another O-ring pressing member. It is an exploded sectional view of the plug mechanism which has an O-ring pressing member (steel ball) and does not have a large diameter hole. It is sectional drawing explaining the state which the O-ring pressing member (steel ball) is pressed against the O-ring inserted in the O-ring insertion part by the rotation of a set screw. It is sectional drawing which shows the state which the seal formation of a pipeline is made by the deformed O-ring. It is an exploded sectional view of the plug mechanism which includes the O-ring pressing member of another example and does not have a large diameter hole. It is sectional drawing explaining the state which the O-ring pressing member of another example is pressed against the O-ring inserted into the O-ring insertion part by the rotation of a set screw. It is sectional drawing which shows the state which the seal formation of a pipeline is made by the deformed O-ring.

The shaft unit 1 according to the present invention shown in FIG. 1 includes, for example, a columnar base shaft portion 10 and a table mounting portion 11 integrally formed on the upper end side of the base shaft portion 10 and having a diameter larger than that of the base shaft portion 10. The vertical cross section is substantially T-shaped.
The shaft unit 1 includes, for example, a grinding device for grinding a workpiece such as a wafer with a rotating grinding wheel, a polishing device for polishing a wafer with a polishing pad made of a non-woven fabric, and an individual cutting device for cutting a wafer with a rotating cutting blade. It is arranged in a cutting device that divides into chips, a laser processing device that irradiates a wafer with a laser beam to perform various processing, and the like.

The table mounting portion 11 in which the chuck table is fixed to the upper surface 11a by bolts or the like includes a plurality of pipelines 110 extending horizontally from the side surface 11c toward the center inside the table mounting portion 11. As shown in FIG. 2, a plurality of pipelines 110 are formed in the table mounting portion 11 at equal intervals in the circumferential direction (for example, six pipelines at intervals of 60 degrees in the circumferential direction), and each of the pipelines 110 is formed. One end of each has an opening (opening 110a) in the side surface 11c.

As shown in FIGS. 1 and 2, a plurality of (for example, six) annular suction grooves 111 are formed on the upper surface 11a of the table mounting portion 11 at intervals in the radial direction. The plurality of annular suction grooves 111 are formed concentrically around the center of the upper surface 11a of the table mounting portion 11, and a plurality of first pores are formed in the groove bottoms at equal intervals in the circumferential direction. 112 is formed in the thickness direction (Z-axis direction). Each of the first pores 112 communicates with each of the pipelines 110.

In the central region of the lower surface 10b of the base shaft portion 10 shown in FIG. 1, a plurality of second holes 100 are opened at equal intervals in the circumferential direction, and each of the second holes 100 is inside the base shaft portion 10. It extends upward and is connected to each pipeline 110.

A first suction pipe 191 made of a metal pipe, a flexible tube, or the like is connected to several of the second holes 100, and the remaining few of the second holes 100 are connected to the first suction pipe 191. The suction pipe 192 of 2 is connected. For example, the first suction pipe 191 and the second suction pipe 192 merge into one and communicate with a suction source 19 such as a vacuum generator. A first valve body 191a capable of switching the opening and closing of the first suction pipe 191 is disposed in the first suction pipe 191, and a second suction pipe 192 is provided in the second suction pipe 192. A second valve body 192a capable of switching between opening and closing of the valve body 192a is provided.

For example, even if the second hole 100 is connected to an air supply source (not shown) for performing air blow when the wafer is separated from the chuck table mounted on the upper surface 11a of the shaft unit 1 and sucking and holding the wafer. good.

A substantially annular connecting member 12 is fixed to the lower surface 10b of the base shaft portion 10 shown in FIG. 1 by a plurality of bolts 120. Then, the shaft unit 1 is connected to a rotating means including a motor or the like (not shown) via a connecting member 12.
For example, the base shaft portion 10 of the shaft unit 1 is rotatably housed in a substantially cylindrical casing 20 via a bearing mechanism 103 arranged on the side surface thereof.

As shown in FIGS. 1 and 2, the opening 110a on the side surface 11c of the table mounting portion 11 of the pipeline 110 is closed by the plug mechanism 5 according to the present invention.
FIG. 3 is an exploded cross-sectional view of the plug mechanism 5. The plug mechanism 5 has a female screw hole 50 having an inner diameter L2 larger than the inner diameter L1 (for example, inner diameter Φ3 mm) of the pipeline 110 toward the inside of the table mounting portion 11 which is a base material from the opening 110a, and a female screw hole 50. A female screw larger than the inner diameter L1 of the conduit 110 at the connecting portion between the large diameter hole 51 having an inner diameter L3 larger than the inner diameter L1 of the conduit 110 and the connecting portion between the conduit 110 and the large diameter hole 51. An O-ring insertion portion 53 for inserting an O-ring 52 having an outer diameter L4 smaller than the inner diameter L2 of the hole 50 and an outer diameter L6 (diameter L6) larger than the inner diameter L5 of the O-ring 52 extend inside the female screw hole 50 in the extending direction. It includes an O-ring pressing member 54 that can be moved forward and backward, and a push screw 55 that is screwed into the female screw hole 50.

The annular O-ring 52 that can be deformed by an external force is preferably made of, for example, hydrogenated nitrile rubber (HNBR) that can withstand use under processing temperature conditions of −50 ° C. to 80 ° C. and is not easily deteriorated by temperature changes. Further, when the shaft unit 1 is used in the polishing apparatus, the O-ring 52 is resistant to deterioration even if a chemical solution (for example, a polishing solution containing SiO2, Al2O3, etc. as free abrasive grains) adheres to the O-ring 52. It is preferably made of resin (PTFE). For example, the O-ring 52 has an outer diameter L4 of Φ4 mm, which is larger than the inner diameter L1 (inner diameter Φ3 mm) of the pipeline 110 and slightly smaller than the inner diameter L2 of the female screw hole 50, and its wire diameter L7 is Φ1 mm, and its inner diameter L5 is. It is Φ2 mm.

The O-ring pressing member 54 is made of a material that is not easily deformed. For example, in the present embodiment, it is a steel ball, but it may be a resin ball made of a hard resin such as polyetheretherketone (PEEK). .. The outer diameter L6 (diameter L6) of the O-ring pressing member 54 (steel ball 54) is, for example, about 4 mm, which is slightly smaller than the inner diameter L2 of the female screw hole 50 and has a size capable of advancing and retreating in the female screw hole 50 in the extending direction. Also, it is larger than the inner diameter L5 (Φ2 mm) of the O-ring 52.

The set screw 55 with the thread 551 engraved on the side surface is, for example, an M5 set screw, and the rear end surface 550 is provided with a fitting hole 550a into which the hexagonal tip of a screwdriver tool is fitted, and the tip surface thereof is an O-ring. It has a substantially flat surface that does not damage the pressing member 54.

The inner diameter L3 of the large-diameter hole 51 is, for example, substantially the same as the inner diameter L2 (diameter excluding the screw groove 500) of the female screw hole 50, and is slightly larger than the outer diameter L6 of the O-ring pressing member 54. It has become.
The O-ring insertion portion 53 formed in the connecting portion between the pipeline 110 and the large-diameter hole 51 has an inner diameter of, for example, abbreviated as the inner diameter L3 of the large-diameter hole 51 toward the conduit 110 side (−Y direction side). The outer diameter of the O-ring 52 is reduced to L4 or less from the same size.

Hereinafter, a case where the opening 110a at one end of the pipeline 110 is closed by the plug mechanism 5 will be described. First, the O-ring 52 shown in FIG. 3 is inserted into the O-ring insertion portion 53 and comes into contact with the surface of the O-ring insertion portion 53 whose diameter is reduced (hereinafter referred to as a reduced diameter surface). Next, the O-ring pressing member 54 is inserted into the large-diameter hole 51 and comes into contact with the O-ring 52.

Next, as shown in FIG. 4, the set screw 55 is screwed into the female screw hole 50 by a screwdriver or the like (not shown). While controlling the tightening torque of the set screw 55, the O-ring pressing member 54 is pressed against the O-ring 52 by the set screw 55, and the O-ring 52 is pressed on the Y-axis by the reduced diameter surface of the O-ring pressing member 54 and the O-ring insertion portion 53. By sandwiching the O-ring 52 from both sides in the direction, the O-ring 52 is deformed so as to follow the spherical surface of the O-ring insertion portion 53 and the O-ring pressing member 54. The shape of the O-ring insertion portion 53 is not limited to the examples shown in FIGS. 3 to 5, but the center of the O-ring 52 inserted into the O-ring insertion portion 53 and the center of the O-ring pressing member 54. It suffices that the pressing force applied to the O-ring 52 from the O-ring pressing member 54 is applied flush with respect to the O-ring 52 from the + Y direction side.
For example, when the wire diameter L7 of the O-ring 52 is smaller than Φ1 mm, the deformed O-ring 52 comes into contact with the entire reduced surface of the O-ring insertion portion 53, unlike the case shown in FIG. However, there is no problem because the space between the O-ring insertion portion 53 and the spherical surface of the O-ring pressing member 54 is sealed by the O-ring 52 without a gap.

Then, as shown in FIG. 5, for example, the set screw 55 is screwed into the female screw hole 50 until the rear end surface 550 of the set screw 55 and the side surface 11c of the table mounting portion 11 are substantially flush with each other. Then, the O-ring 52 is in a state of sealing between the O-ring insertion portion 53 and the O-ring pressing member 54 without a gap, and the pipeline 110 can be in a state of being shielded from the outside air. It should be noted that making the rear end surface 550 of the set screw 55 and the side surface 11c of the table mounting portion 11 substantially flush with each other is one form of a guideline for forming a seal by the O-ring 52, and is limited to this. It is not something that will be done.

The O-ring pressing member 54 is not limited to a sphere made of a material that is not easily deformed as shown in FIGS. 3 to 5. For example, the O-ring pressing member 58 shown in FIG. 6 is made of steel or a rigid resin, and is integrally formed with the cylindrical portion 581 with which the push screw 55 contacts and the cylindrical portion 581, and the diameter is reduced toward the O-ring 52 side. It is provided with a truncated cone-shaped O-ring contact portion 580. The outer diameter L6 of the cylindrical portion 581 of the O-ring pressing member 58 is larger than the inner diameter L5 of the O-ring 52.

Similarly, when the plug mechanism 5 includes the O-ring pressing member 58, the O-ring 52 shown in FIG. 6 is inserted into the O-ring insertion portion 53 and abuts on the reduced diameter surface. Next, the O-ring pressing member 58 is inserted into the large-diameter hole 51 from the O-ring contact portion 580 side, the O-ring contact portion 580 fits into the opening of the O-ring 52, and the outer slope of the O-ring contact portion 580. The O-ring 52 comes into contact with the surface.

Next, as shown in FIG. 7, the set screw 55 is screwed into the female screw hole 50. While controlling the tightening torque of the push screw 55, the O-ring pressing member 58 is pressed against the O-ring 52 by the push screw 55, and the O-ring is formed on the outer slope of the O-ring contact portion 580 and the reduced diameter surface of the O-ring insertion portion 53. By sandwiching the 52 from both sides in the Y-axis direction, the O-ring 52 is deformed so as to follow the outer slopes of the O-ring insertion portion 53 and the O-ring contact portion 580.

Then, for example, the O-ring 52 is O-ringed by screwing the set screw 55 into the female screw hole 50 until the rear end surface 550 of the set screw 55 and the side surface 11c of the table mounting portion 11 are substantially flush with each other. The ring insertion portion 53 and the O-ring pressing member 58 are sealed without a gap, and the pipeline 110 can be shielded from the outside air.

Each opening 110a of the remaining five pipelines 110 of the shaft unit 1 shown in FIG. 1 is closed by a plug mechanism 5 provided with an O-ring pressing member 54 (or an O-ring pressing member 58) in the same manner as described above.
As described above, the shaft unit 1 according to the present invention is connected to the plurality of first pores 112 connected from the upper surface 11a to the conduit 110 formed inward from the side surface 11c and from the lower surface 10b to the conduit 110. It has a second hole 100 and a plug mechanism 5 for closing the opening 110a on the side surface 11c of the pipeline 110, and the plug mechanism 5 is a female screw having an inner diameter L2 larger than the inner diameter L1 of the pipeline 110 toward the inside from the opening 110a. The hole 50 and the large-diameter hole 51 having an inner diameter L3 larger than the inner diameter L1 of the conduit 110 connected to the female screw hole 50 inward from the female screw hole 50, and the connecting portion between the conduit 110 and the large-diameter hole 51. An O-ring insertion portion 53 for inserting an O-ring 52 having an outer diameter L4 larger than the inner diameter L1 of the conduit 110 and smaller than the inner diameter L2 of the female screw hole 50, and an outer diameter L6 larger than the inner diameter L5 of the O-ring 52 are female. An O-ring pressing member 54 capable of advancing and retreating in the screw hole 50 in the extending direction and a push screw 55 screwed into the female screw hole 50 are provided, and the push screw 55 screwed into the female screw hole 50 is used for O-ring. A state in which the ring pressing member 54 is pressed against the O-ring 52 inserted into the O-ring inserting portion 53, the O-ring 52 is sandwiched between the O-ring pressing member 54 and the O-ring inserting portion 53, and the O-ring 52 is crushed to form a seal. Since the opening 110a is plugged with the O-ring 52, the O-ring pressing member 54, and the push screw 55, the upper surface 11a of the shaft unit 1 is not inflated. Therefore, it is not necessary to flatten the upper surface 11a of the shaft unit 1 after plugging.

For example, when a spherical elastic member is simply packed inside the unit from the opening 110a as a sealing member, it may be difficult to remove the elastic member from the opening 110a, but the O-ring 52, the O-ring pressing member 54, Since the push screw 55 is removable from the shaft unit 1, cleaning and maintenance in the pipeline 110 can be easily performed. Further, since the push screw 55 does not come into direct contact with the O-ring 52, the situation that the O-ring 52 is twisted by the rotational force of the push screw 55 and the seal formation ends unsuccessfully does not occur.
Further, when the O-ring pressing member 54 is pushed by the push screw 55 and the O-ring 52 is deformed by the O-ring pressing member 54, the O-ring pressing member 54 can proceed straight through the large-diameter hole 51 without rattling. Since the O-ring 52 and the O-ring pressing member 54 are in contact with each other without shifting their centers, the seal formation can be performed more reliably.

As shown in FIGS. 1 and 2, in a state where each opening 110a of the six pipelines 110 of the shaft unit 1 is closed by the plug mechanism 5, a chuck table (not shown) is placed on the upper surface 11a of the substantially flat shaft unit 1. It is placed and fixed by bolts or the like. Then, the suction force generated by driving the suction source 19 shown in FIG. 1 is the first suction pipe 191 and the second suction pipe 192, each second hole 100, each pipeline 110, and each first narrow line. By being transmitted to the holding surface of the chuck table through the holes 112 and each annular suction groove 111, the chuck table can suck and hold the plate-shaped wafer on the holding surface.
Since the opening 110a is closed by the plug mechanism 5, and the upper surface 11a of the shaft unit 1 is a flat surface and is in close contact with the lower surface of the chuck table, no vacuum leak occurs in the shaft unit 1.

For example, a chuck table mounted on the shaft unit 1 has a universal type chuck table (for example, a chuck having a central holding surface and a plurality of annular holding surfaces) capable of sucking and holding wafers of a plurality of sizes. In the case of a table), the opening / closing control of the first valve body 191a or the second valve body 192a is performed so that the suction force can be transmitted only to the holding surface of the chuck table according to the wafer size to be held.

When the wafer sucked and held by the chuck table is separated from the holding surface of the chuck table, the air supplied by the air supply source (not shown) is supplied to each second hole 100, each pipeline 110, and each first pore 112. And through each annular suction groove 111, air is ejected from the holding surface of the chuck table. Then, the vacuum suction force between the holding surface and the wafer is removed by the injection pressure of the air, and the wafer is separated from the holding surface.
The pressure in the conduit 110 when the wafer is sucked and held on the chuck table holding surface as described above is, for example, -80 KPa at the minimum, and is in the conduit 110 when the wafer is detached by air blow from the chuck table holding surface. The pressure is, for example, 500 KPa at the maximum. The plug mechanism 5 can maintain a state in which the opening 110a is closed and the pipe line 110 is shielded from the outside air even if there is such a pressure fluctuation in the pipe line 110.

The plug mechanism according to the present invention provided in the shaft unit 1 may be the plug mechanism 5A shown in FIG. 9 which does not have the large diameter hole 51. The difference between the plug mechanism 5 and the plug mechanism 5A described above is whether or not the large diameter hole 51 is provided, and the other configurations are substantially the same.
In the plug mechanism 5A, the female screw hole 50 is formed longer toward the inside than in the case of the plug mechanism 5 shown in FIG. 3, and the O-ring insertion portion 53 connects the conduit 110 and the female screw hole 50. It is formed in a portion, and for example, the inner diameter is reduced from about the same size as the inner diameter L2 of the female screw hole 50 to the outer diameter L4 or less of the O-ring 52 toward the conduit 110 side (-Y direction side). It has a diameter.

When the opening 110a at one end of the pipeline 110 is closed by the plug mechanism 5A, the O-ring 52 shown in FIG. 9 is first inserted into the O-ring insertion portion 53 and abuts on the reduced diameter surface of the O-ring insertion portion 53. .. Further, the O-ring pressing member 54 is inserted into the female screw hole 50 and comes into contact with the O-ring 52. Next, as shown in FIG. 10, a set screw 55 is screwed into the female screw hole 50, and the O-ring 52 is sandwiched between the O-ring pressing member 54 and the reduced diameter surface of the O-ring insertion portion 53 from both sides in the Y-axis direction. By doing so, the O-ring 52 is deformed so as to follow the spherical surface of the O-ring insertion portion 53 and the O-ring pressing member 54.

Then, as shown in FIG. 11, the set screw 55 is screwed into the female screw hole 50 until the rear end surface 550 of the set screw 55 and the side surface 11c of the table mounting portion 11 are substantially flush with each other. The O-ring 52 is in a state of being tightly sealed between the O-ring insertion portion 53 and the O-ring pressing member 54, and the pipeline 110 can be in a state of being shielded from the outside air. Further, the upper surface 11a of the table mounting portion 11 does not swell and remains flat.

The plug mechanism 5A may also be configured to include the O-ring pressing member 58 instead of the O-ring pressing member 54, as shown in FIG.
In this case, the O-ring 52 is inserted into the O-ring insertion portion 53 and abuts on the reduced diameter surface thereof. Next, the O-ring pressing member 58 is inserted into the female screw hole 50 from the O-ring contact portion 580 side, the O-ring contact portion 580 fits into the opening of the O-ring 52, and the O-ring 52 abuts on the outer slope thereof. .. Next, as shown in FIG. 13, the set screw 55 is screwed into the female screw hole 50. While controlling the tightening torque of the push screw 55, the O-ring pressing member 58 is pressed against the O-ring 52 by the push screw 55, and the O-ring is formed on the outer slope of the O-ring contact portion 580 and the reduced diameter surface of the O-ring insertion portion 53. By sandwiching the 52 from both sides in the Y-axis direction, the O-ring 52 is deformed so as to follow the outer slopes of the O-ring insertion portion 53 and the O-ring contact portion 580.

Then, for example, the O-ring 52 is O-ringed by screwing the set screw 55 into the female screw hole 50 until the rear end surface 550 of the set screw 55 and the side surface 11c of the table mounting portion 11 are substantially flush with each other. The ring insertion portion 53 and the O-ring pressing member 58 are sealed without a gap, and the pipeline 110 can be shielded from the outside air. Further, the upper surface 11a of the table mounting portion 11 does not swell and remains flat.

1: Shaft unit 10: Base shaft part 10b: Bottom surface of base shaft part 100: Second hole 191: First suction pipe 191a: First valve body 192: Second suction pipe 192a: Second valve body 19: Suction source 11: Table mounting part 11a: Top surface of table mounting part 11c: Side surface of table mounting part 110: Pipe line 110a: Opening 111: Circular suction groove 112: First pore 12: Connecting member 120: Bolt 103: Bearing mechanism 20 : Casing 5: Plug mechanism 50: Female screw hole 51: Large diameter hole 52: O-ring 53: O-ring insertion part 54: O-ring pressing member 55: Push screw 58: Ring pressing member
5A: Plug mechanism

Claims (4)

A plurality of first holes connecting from the upper surface to the pipeline formed from the side surface to the inside, a second hole connecting to the pipeline from the lower surface, and a plug mechanism for closing the opening on the side surface of the pipeline. It is a shaft unit that has
The plug mechanism is
A female screw hole with an inner diameter larger than the inner diameter of the pipeline toward the inside from the opening,
An O-ring insertion portion having an inner diameter smaller than the inner diameter of the female screw hole formed at the connecting portion between the pipeline and the female screw hole,
An O-ring pressing member having an outer diameter larger than the inner diameter of the O-ring, having a spherical surface or a conical surface on the pipeline side , and being able to advance and retreat in the female screw hole and in the O-ring insertion portion in the extending direction.
With a set screw to be screwed into the female screw hole ,
The O-ring pressing member is pressed against the O-ring inserted into the O-ring insertion portion with the push screw screwed into the female screw hole, and the spherical surface or the conical surface of the O-ring pressing member and the O-ring. A shaft unit that sandwiches the O-ring with an insertion portion and a part of the O-ring pressing member enters the inner diameter of the O-ring to form a seal, close the opening, and form the conduit. The plug mechanism is
A large-diameter hole having an inner diameter larger than the inner diameter of the pipeline is further provided in the female screw hole so as to be connected inward from the female screw hole, and the O-ring insertion portion is formed by the conduit and the large-diameter hole. The shaft unit according to claim 1, which is formed on a connecting portion. It is a plug mechanism that closes the opening at one end of the pipeline formed from the side surface of the base metal toward the inside.
A female screw hole with an inner diameter larger than the inner diameter of the pipeline toward the inside from the opening,
An O-ring insertion portion having an inner diameter smaller than the inner diameter of the female screw hole formed at the connecting portion between the pipeline and the female screw hole,
An O-ring pressing member having an outer diameter larger than the inner diameter of the O-ring, having a spherical surface or a conical surface on the pipeline side , and being able to advance and retreat in the female screw hole and in the O-ring insertion portion in the extending direction.
With a set screw to be screwed into the female screw hole ,
The O-ring pressing member is pressed against the O-ring inserted into the O-ring insertion portion with the push screw screwed into the female screw hole, and the spherical surface or the conical surface of the O-ring pressing member and the O-ring. A plug mechanism that sandwiches the O-ring with an insertion portion and a part of the O-ring pressing member enters the inner diameter of the O-ring to form a seal and close the opening. A large-diameter hole having an inner diameter larger than the inner diameter of the pipeline is further provided in the female screw hole so as to be connected inward from the female screw hole, and the O-ring insertion portion is formed by the conduit and the large-diameter hole. The plug mechanism according to claim 3, which is formed on the connecting portion.

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