JP2001271808A - Air bearing cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bearing cylinder inexpensive, which is easy to manufacture and superior in thrust characteristics. SOLUTION: A first pressure applying part 41 for canceling the self weight of a rod and a second pressure applying part 42 for driving control of the rod are formed on the peripheral surface of the rod 4 constituting a cylinder 1. The first and second pressure applying parts 41, 42 are formed along the longitudinal direction of the rod, so as to stand on different levels. Two kinds of mutually independent pressure applying chambers 27, 28 are formed between the inner wall surface of an insertion hole 3 and the peripheral surface of the rod 4. The first pressure applying part 41 is disposed in the first pressure applying chamber 27 and is structured with the control air being suppliable there via a first port 25. The second pressure applying part 42 is disposed in the second pressure applying chamber 28 and is structured so that the control air can be supplied there via a second port 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bearing cylinder.

[0002]

2. Description of the Related Art Conventionally, for example, a die bonder is known as a typical example of an apparatus used in a semiconductor manufacturing process. This type of apparatus usually includes a bonding head that can be driven in a two-dimensional direction or a three-dimensional direction, and an air cylinder having a rod for vacuum-sucking a semiconductor chip is attached thereto. In particular, in recent years, since high-precision control of the rod has been demanded, a type equipped with an air bearing cylinder equipped with a non-contact type bearing member using air pressure has appeared. Here, the conventional air bearing cylinder 61
FIG. 6 shows an example.

A cylinder block 62 constituting the air bearing cylinder 61 is installed so as to be able to move integrally with a bonding head (not shown). A rod insertion hole 63 is formed in the cylinder block 62 and opens at the lower end surface of the cylinder block 62. A rectangular column-shaped vacuum suction rod 64 is drivably inserted in the rod insertion hole 63 having a rectangular cross section along its own longitudinal direction. 8 places in the rod insertion hole 63 (4 places in the upper position,
A porous body 69 as a bearing member is provided at the four lower positions). Pressurized air is supplied to these porous bodies 69 through passages 70a and 70b and a port 70 communicating with the passages 70a and 70b. Then
By the action of pressurized air ejected from the porous body 69,
The rod 64 is supported on the cylinder block 62 in a non-contact manner.

[0004] At the upper end portion of the rod 64, a proximal pressure acting portion 71 for providing a thrust for driving the rod 64 in a direction to protrude from the lower end surface of the cylinder block 62 is formed. A port 73 communicates with a proximal pressure application chamber 72 that accommodates the proximal pressure application section 71 via a passage 73a. This port 73 and passage 73a
The control air supplied to the proximal pressure action chamber 72 via
The rod 64 acts on the proximal pressure acting portion 71 to push the rod 64 downward.

On the other hand, in the middle of the rod 64, a step portion (tip-side pressure acting portion) that provides a thrust for driving the rod 64 in a direction to be immersed in the cylinder block 62.
74 are formed. A port 76 communicates with a pressure action chamber 75 containing the stepped portion 74 via a passage 76a. The control air supplied to the pressure action chamber 75 through the port 76 and the passage 76a acts on the step 74 to press the rod 64 upward. That is, the air bearing cylinder 61 is a double-acting type in which the rod 64 can be driven in two directions.

Further, at the lower end of the rod 64, there is formed a stepped portion (pressure acting portion for eliminating its own weight) 77 for providing at least a thrust for eliminating the weight of the rod 64. A port 79 communicates with the pressure action chamber 78 containing the step portion 77 via a passage 79a. The control air supplied to the pressure action chamber 78 via the port 79 and the passage 79a acts on the step portion 77 to constantly push the rod 64 upward. In addition, the above-mentioned step part 74,
77 is formed so as to go around four surfaces constituting the rod outer peripheral surface.

[0007]

However, in the above-mentioned conventional cylinder structure, when the rod 64 is manufactured, there are many places to be polished to form the step portions 74 and 77, which makes the manufacturing difficult and difficult. Soaring costs were inevitable.

Further, as shown in FIGS. 7 and 8, two step portions 74 and 77 are arranged in the same plane which is perpendicular to the longitudinal direction of the rod 64, and both step portions 74 and 77 are provided.
Conventionally, a technique has been proposed in which two pressure action chambers 75 and 78 corresponding to are separated by a metal seal 80.
A similar one is disclosed in Japanese Patent Application Laid-Open No. H11-287211. In this prior art, the rod 6
The simplification of the shape of No. 4 facilitates manufacturing and reduces manufacturing costs.

However, in the case of this prior art in which the metal seal 80 is a constituent element, when the magnitude relationship between the pressures in the pressure action chambers 75 and 78 changes, the direction of the control air flowing through the metal seal 80 is reversed. As a result, the thrust value of the rod 64 fluctuates, and the thrust that should be linear is locally disturbed.

As a countermeasure for preventing such deterioration of the thrust characteristics, it is considered that, for example, the processing accuracy of the metal seal 80 may be increased or a sufficient seal length may be set. However, the above measures may be contrary to facilitation of manufacturing and reduction of manufacturing cost.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an air bearing cylinder which is inexpensive, easy to manufacture, and has excellent thrust characteristics.

[0012]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a cylinder block having a rod insertion hole can be driven in the rod insertion hole along its own longitudinal direction. And a bearing member provided on the inner wall surface of the rod insertion hole and ejecting pressurized air to the rod to support the rod in a non-contact manner, and at least the rod A first pressure acting portion for providing a thrust for eliminating the own weight and a second pressure acting portion for providing a thrust for driving and controlling the rod are formed on the outer peripheral surface of the rod, and the rod insertion hole is Of the two independent pressure action chambers formed between the inner wall surface and the outer peripheral surface of the rod, the first pressure action portion is disposed in the first pressure action chamber and is connected via the first port. So An air bearing cylinder in which control air can be supplied to the second pressure action chamber and control air can be supplied thereto through a second port. And the second pressure acting portion is arranged stepwise along the longitudinal direction of the rod, and a fluid pressure seal mechanism for ejecting pressurized air to the rod is disposed between the two pressure acting chambers. The gist is a characteristic air bearing cylinder.

According to a second aspect of the present invention, in the first aspect, the rod is substantially prismatic, and the first and second rods are formed.
It is assumed that the pressure acting portion is formed only on one of the plurality of rod outer peripheral surfaces.

According to a third aspect of the present invention, in the first or second aspect, the fluid pressure sealing mechanism also serves as a bearing member for supporting the rod in a non-contact manner. Hereinafter, the “action” of the present invention will be described.

According to the first aspect of the present invention, since the two pressure action chambers are sealed by the fluid pressure seal mechanism for ejecting pressurized air to the rod, the direction of the control air flowing through the seal mechanism is changed. Be constant. Therefore, even if the magnitude relationship between the pressures in the two pressure action chambers changes, the thrust value of the rod does not change. In addition, since the two pressure acting portions are arranged stepwise along the longitudinal direction of the rod, the shape is simplified, so that the number of processing portions during manufacturing can be reduced.

According to the second aspect of the present invention, since the rod has a substantially prismatic shape, that is, a non-circular shape, it is possible to prevent rotation in the rod insertion hole and to minimize the number of processing portions during rod manufacturing. .

According to the third aspect of the present invention, since the fluid pressure sealing mechanism also serves as a bearing member for supporting the rod in a non-contact manner, the rigidity of the entire bearing is increased, and the bearing can withstand a larger lateral load. It will be. Further, an increase in the number of parts can be prevented.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cylinder system C1 using an air bearing cylinder 1 according to an embodiment of the present invention will be described below in detail with reference to FIGS.

The cylinder system C1 constitutes a part of a semiconductor manufacturing apparatus (specifically, a die bonder in this case). This device includes a bonding head (not shown) that can be driven in a three-dimensional direction. The cylinder system C1 of this embodiment is installed on the bonding head and is driven integrally with the head.

As shown in FIG. 1, the cylinder system C1 comprises an air bearing cylinder 1 and a structure for supplying and discharging pressurized air thereto. First, the structure of the air bearing cylinder 1 will be described.

A metal cylinder block 2 constituting the air bearing cylinder 1 has a rod insertion hole 3. The rod insertion hole 3 has a substantially rectangular cross section, and extends along the vertical direction of the cylinder block 2. The rod insertion hole 3 penetrates and opens at the center of the upper and lower ends of the cylinder block 2.

A rod 4 for vacuum suction is movably inserted into the rod insertion hole 3 along its own longitudinal direction. Here, four outer peripheral surfaces of the rod 4 are S1, S2, S3, and S4 for convenience of explanation. The base end side (that is, the upper end side) of the rod 4 protrudes from the opening of the rod insertion hole 3 on the upper end side of the cylinder block 2. Further, the tip end side (that is, the lower end side) of the rod 4 projects from the opening of the rod insertion hole 3 on the lower end side of the cylinder block 2. A vacuum suction jig 6 as a rod-attached member is attached to the lower end surface of the rod 4 so as to be able to move integrally with the rod 4. The semiconductor chip 5 as an object to be sucked is vacuum-sucked to the jig 6.

A vacuum passage 7 is formed inside the vacuum suction rod 4 by, for example, drilling. One side of the evacuation passage 7 is open at the lower end surface of the rod 4, and the other side is an outer peripheral surface S 3, S 4 of the rod 4.
At a predetermined location. The jig 6 also has a through hole formed at a position corresponding to the evacuation passage 7. The lower end side opening 7b of the evacuation passage 7 is formed in a circular shape. The opening 7a on the outer peripheral surface side of the evacuation passage 7 is also formed in a circular shape. However, the outer peripheral surface side opening 7a is preferably formed in an elongated oval shape along the axial direction of the rod 4.

As shown in FIG. 1, at predetermined locations on the inner wall surface of the rod insertion hole 3, the porous body mounting recesses 17, 18 are provided.
Are formed. Porous body mounting recess 1 located at the top
7, a porous body 15 as an upper end bearing member is provided. The porous body 15 is plate-shaped and has two pairs (a total of 4 pairs).
) And are spaced apart from each other. A porous body 16 as a lower end bearing member is provided in the porous body mounting recess 18 located at the lower part. The porous bodies 16 are also plate-shaped and have two pairs (a total of four), and are spaced apart from each other.

When the rod 4 is inserted, the base end side porous body 15 faces the outer peripheral surfaces S1 to S4 and blows out pressurized air to the upper ends of the surfaces S1 to S4.
The distal end side porous body 16 faces the outer peripheral surfaces S1 to S4 when the rod 4 is inserted, and the surfaces S1 to S4.
The pressurized air is blown out to the lower end of 4.

As a material for forming the porous bodies 15 and 16, for example, a metal material such as sintered aluminum, sintered copper, and sintered stainless steel can be used. In addition, synthetic resin materials such as sintered trifluoride resin, sintered tetrafluoride resin, sintered nylon resin, sintered polyacetal resin, etc., sintered carbon, sintered graphite, sintered ceramics, etc. are used. It is possible.

As shown in FIG. 1, an air supply port 21 is formed on one side surface of the cylinder block 2. This air supply port 21 is directly connected to the air supply source P via a pipe L1. The region having the porous body mounting recess 17 and the air supply port 21 are communicated with each other through a passage 21a. Also, two porous body mounting recesses 17, 1
8 are communicated via a passage 21b.

Accordingly, when pressurized air is supplied to the air supply port 21, the pressurized air passes through the passage 21a and reaches the outer surface of the base-side porous body 15, and the passage 21a
a, 21b, and reaches the outer surface of the distal end porous body 16. The pressurized air is supplied to both porous bodies 15,
16 are ejected from the inner surface of the rod 16 toward the outer peripheral surfaces S1 to S4 of the rod 4. The rod 4 is supported in a non-contact manner with respect to the rod insertion hole 3 of the cylinder block 2 by the static pressure generated by the compressed air ejected as described above. That is, the air bearing cylinder 1 has a static pressure thrust bearing.

On one side surface of the cylinder block 2, a position corresponding to the outer peripheral surface side opening 7 a of the evacuation passage 7 is provided.
An evacuation port 23 is provided. The evacuation port 23 communicates with the rod insertion hole 3 via a passage 23a. The evacuation port 23 is connected to a vacuum pump via a pipe. Therefore, the air in the area on the lower surface side of the jig 6 is sucked through the piping, the evacuation port 23, the passage 23a, and the evacuation passage 7 by the operation of the vacuum pump. As a result, the lower surface side area of the jig 6 has a negative pressure, and the semiconductor chip 5 is sucked and held there.

Further, as shown in FIG. 1, a further porous body mounting recess 31 is formed at a predetermined position on the inner wall surface of the rod insertion hole 3. The porous body mounting recess 31 is located between the two porous body mounting recesses 17 and 18. In such a porous body mounting recess 31,
A porous body 32 is provided as a fluid pressure sealing mechanism. The porous bodies 32 are plate-shaped and have two pairs (a total of four), and are spaced apart from each other. The material for forming the porous body 32 is basically the same as that of the porous body 1.
It is the same as the forming materials 5 and 16.

The passage 21b branches off in the middle and is connected to the porous body mounting recess 31. Therefore, the region where the porous body mounting concave portion 31 exists and the air supply port 2
1 is communicated through passages 21a and 21b.
Therefore, when pressurized air is supplied to the air supply port 21, the pressurized air passes through the passages 21a and 21b and is
2 and the outer peripheral surfaces S1 to S
It is squirted toward 4. The porous body 32 as a fluid pressure sealing mechanism also serves as a bearing member for supporting the rod 4 in a non-contact manner, as is apparent from its function.

Next, the structure of the vacuum suction rod 4 of the present embodiment will be described with reference to FIG. This rod 4
Is a metal member (for example, stainless steel) having a substantially quadrangular prism shape, and has four outer peripheral surfaces S1, S2, S as described above.
3, S4. The four outer peripheral surfaces S1, S2,
Two of S3 and S4 have first and second step portions 4 as first and second pressure acting portions.
1, 42 are formed. More specifically, only one first step portion 41 is formed on the outer peripheral surface S1, and only one second step portion 42 is formed on the outer peripheral surface S2. That is, both the first step portion 41 and the second step portion 42 are formed only on one of the plurality of outer peripheral surfaces S1 to S4.

In the present embodiment, the first step portion 41 plays a role of giving a thrust to the rod 4 for eliminating the weight of the rod 4 and the jig 6 by its own weight. The second step portion 42 plays a role of providing a thrust for drivingly controlling the rod 4 in the upward direction.

The steps 41 and 42 can be formed by grinding or die processing. The portions above the step portions 41 and 42 and the step portions 41 and 4
The portions below 2 are each polished using a conventionally known polishing apparatus. In other words, the outer peripheral surfaces S1 and S2 need to be polished twice.

As shown in FIGS. 1 and 2, the first step 41 is higher than the second step 42 with respect to the longitudinal direction of the rod 4. That is, these two step portions 41 and 42 are not arranged at the same height but are arranged stepwise along the longitudinal direction of the rod 4. These two outer peripheral surfaces S1 and S2 have a positional relationship of being on opposite sides with respect to the center of the rod 4, and
Both are no longer flat. Further, both step portions 41 and 42 are formed so as to face the protruding end side of the rod 4, that is, the lower end side.

The remaining two outer peripheral surfaces S3 and S4 have no irregularities such as the steps 41 and 42 and are completely flat. Two flat outer peripheral surfaces S3, S4
Are formed in a positional relationship on the opposite sides with respect to the center of the rod 4. It should be noted that the outer peripheral surfaces S3 and S4 need only be polished once.

The rod 4 is provided with through holes 43 and 44. These through holes 43 and 44 are formed on the outer peripheral surfaces S1 and S
The two are communicated with each other. Therefore, the same air pressure acts on the region on the outer peripheral surface S1 side and the region on the outer peripheral surface S2 side in the rod insertion hole 3.

The effective pressure receiving area of the first step portion 41 is
The effective pressure receiving area of the step portion 42 is preferably set to be equal to or larger than the effective pressure receiving area. Preferably, the effective pressure receiving area ratio between the two is set to 2 or more, more preferably 4 or more.

When the rod 4 is inserted through the rod insertion hole 3, the inner wall surface of the rod insertion hole 3 and the outer peripheral surface S1
There are two spaces between S4. First step portion 41
Is referred to as a first pressure action chamber 35,
The space in which the second step portion 42 is disposed is referred to as a second pressure action chamber 36.

As shown in FIG. 1, the first pressure action chamber 27 is disposed above the second pressure action chamber 28 with reference to the longitudinal direction of the rod 4. The first pressure action chamber 27 is located immediately above the porous body 32 serving as the fluid pressure sealing mechanism, and the second pressure action chamber 28 is located immediately below the porous body 32. In other words, a porous body 32 that ejects pressurized air to the rod 4 is disposed between the pressure action chambers 27 and 28. The two pressure action chambers 27 and 28 are separated from each other by being sealed by the porous body 32.

As shown in FIG. 1, a first thrust port 25 is provided on one side surface of the cylinder block 2. The first thrust port 25 is connected to the first thrust port 25 via a passage 25a.
Of the pressure action chamber 27. Therefore, the control air supplied to the first thrust port 25 can reach the first pressure action chamber 27 via the passage 25a.

On the other hand, a second thrust port 26 is provided in the cylinder block 2 at a position just opposite to the position where the first thrust port 25 is located. The second thrust port 26 communicates with the second pressure action chamber 28 via a passage 26a. Therefore, the control air supplied to the second thrust port 26 can reach the second pressure action chamber 28 via the passage 26a.

Then, the first and second step portions 41, 42
, The rod 4 is pressed upward by a predetermined force. Accordingly, a thrust for retracting the rod 4, more specifically, a thrust in a direction of immersing the rod 4 from the lower end surface of the cylinder block 2 is applied to the rod 4. However, the thrust provided by the first step portion 41 is set to be several times larger than the thrust provided by the second step portion 42. This is based on the difference between the roles of the two step portions 41 and 42.

As shown in FIG. 1, a pipe L4 connected to the second thrust port 26 is connected to a pipe L1 connecting the air supply source P and the air supply port 21. A regulator R1 and an electropneumatic regulator R2 as a pressure control valve are provided in the middle of the pipe L4. The regulator R1 serves to reduce the pressure of the pressurized air from the air supply source P to a predetermined pressure. The electropneumatic regulator R2 located downstream of the regulator R1 plays a role of further reducing the pressurized air depressurized by the regulator R1 to a desired control air. That is, the pipe L
On step 4, the pressure is reduced in two stages.

Accordingly, control air having a reduced pressure and a constant pressure is supplied to the second thrust port 26 through the pipe L4. The set pressure of the regulator R1 can be appropriately adjusted manually, and the set pressure of the electropneumatic regulator R2 can be appropriately adjusted by an external controller (not shown).

A pipe L7 connected to the first thrust port 25 is connected to a pipe L1 connecting the air supply source P and the air supply port 21. In the pipe L7 on the first thrust port 25 side, there is provided a regulator R3 capable of appropriately adjusting the set pressure manually. Note that the set pressure of the regulator R3 is set to a value different from the set pressure of the regulator R1, that is, an optimum value for providing a thrust for eliminating the weight of the rod 4 and the jig 6. Therefore, control air having a constant pressure value is always supplied to the first thrust port 25 side.

Next, the operation of the air bearing cylinder 1 and the cylinder system C1 configured as described above will be described. Pressurized air supplied from the air supply source P is always supplied to the porous bodies 15, 16, and 32 via the air supply port 21. Therefore, the rod 4 is brought into non-contact with the porous bodies 15, 16, 32 in the rod insertion hole 3 by the pressure of the pressurized air jetted from the porous bodies 15, 16, 32 to the rod 4. It is supported. The air supply source P
Is supplied to the first pressure action chamber 27 at a constant pressure through the first thrust port 25 at all times. Therefore, the rod 4 and the jig 6 are lifted with a thrust of a magnitude substantially corresponding to their own weight. That is, the weight of the rod 4 and the jig 6 is eliminated. At this time, since control air is supplied to the second pressure action chamber 28 via the second thrust port 26, the rod 4 is in a state of retreating (moving upward).

In this state, the jig 6 uses the semiconductor chip 5
After the bonding head is moved to a predetermined chip supply position to suck and hold the second pressure action chamber 28,
The supply of control air to the As a result, the rod 4 moves forward (downward). If the evacuation is started prior to this, the semiconductor chip 5 can be suction-held on the lower surface side of the jig 6. Thereafter, the rod 4 is retracted again.

Next, the bonding head is moved onto the die area of the lead frame while holding the semiconductor chip 5 by suction. Then, the rod 4 is advanced, and the jig 6 is moved.
The semiconductor chip 5 is pressed against the die area with a predetermined pressing force. As a result, the semiconductor chip 5 is securely bonded to the die area as the bonding surface. Thereafter, the evacuation is stopped, the semiconductor chip 5 is released, and then the rod 4 is retracted, thereby completing a series of die bonding steps.

Further, the graphs of FIGS. 3 and 4 will be described. FIG. 3A shows the displacement (μm) of the rod 4 and the second displacement in the cylinder 1 of the embodiment using the fluid pressure sealing mechanism.
3 is a graph showing a relationship between the pressure (kPa) in the pressure action chamber 28 and the pressure in the pressure action chamber 28. FIG. 4A shows the second pressure action chamber 28.
6 is a graph showing the relationship between the internal pressure (kPa) and the thrust (N).

FIG. 3B shows a prior art cylinder represented by FIG. 7 (that is, a structure in which two pressure action chambers corresponding to both step portions are separated by a metal seal).
Rod displacement (μm) and pressure (kP
6 is a graph showing the relationship with FIG. FIG. 4B is a graph showing the relationship between the pressure (kPa) in the pressure action chamber and the thrust (N).

The slope of the line segment in the graph of FIG.
It is clearly larger than the slope of the line segment in the graph of FIG. More specifically, when the pressure in the second pressure action chamber 28 is changed by the same degree, the displacement of the rod 4 in the embodiment is about １ ／ of that in the prior art. This means that the embodiment is more suitable for high-precision control of the rod 4 than the prior art.

Further, the line segment in the graph of FIG. 4B is linear, and even if the pressure in the second pressure action chamber 28 is changed, no disturbance occurs in the thrust value. On the other hand, although the line segment in FIG. 4A can be said to be linear as a whole, it can be seen that the thrust value is locally disturbed. It is considered that this turbulence is caused by a change in the magnitude relationship between the pressures in the two pressure action chambers and a reversal of the direction of the control air flowing through the metal seal.

Therefore, according to the present embodiment, the following effects can be obtained. (1) In the cylinder system C1 of the present embodiment, the control air acts on the first pressure action chamber 27 and the first step portion 41 disposed inside the first pressure action chamber 27 to reduce the weight of the rod 4 and the jig 6 by its own weight. Thrust for canceling is provided to the rod 4 and the like.
As a result, the rod 4 and the jig 6 and the gravity acting on them are balanced, and the influence of the gravity on the control accuracy is reduced. Further, the control air supplied to the second pressure action chamber 28 acts on the second step portion 42 disposed inside the second pressure action chamber 28, and generates a thrust for driving and controlling the rod 4 in the backward direction.

(2) First and second pressure action chambers 27 and 2
8 are independent of each other, each pressure action chamber 27,
The control air at an appropriate pressure can be separately supplied to each of the 28. Therefore, the control air for obtaining the thrust necessary for eliminating the self-weight and the control air for obtaining the thrust required for the drive control in the backward direction can be separated. Therefore, there is a merit that they do not need to be shared. As a result, drive control can be performed with a small control pressure, and the drive pressure of the rod 4 can be controlled with high accuracy by appropriately adjusting the control pressure.

(3) In the cylinder system C1, the space between the two pressure action chambers 27 and 28 is sealed by the porous body 32 that blows out pressurized air to the rod 4. Therefore, the direction of the control air flowing through the porous body 32, which is a fluid pressure sealing mechanism, is always constant. In other words, pressurized air is constantly ejected from the inner surface side of the porous body 32, and the ejected pressurized air is constantly flowing into the two pressure action chambers 27 and 28. Therefore, both pressure action chambers 2
Even if the magnitude relation between the pressures in the pressures 7 and 28 changes, the thrust value of the rod 4 does not change. Therefore, it is possible to realize the cylinder 1 having excellent thrust characteristics.

Further, in this cylinder system C1, the first and second step portions 41 and 42, which are pressure acting portions, are arranged stepwise along the longitudinal direction of the rod 4, and the shape of the rod 4 is also compared. Is simple. For this reason, the number of processing locations during manufacturing can be reduced. For example, whereas the rod of the prior art shown in FIG. 6 has twelve polished portions, the rod 4 of the present embodiment has six polished portions, which are reduced in each stage. Therefore, the cylinder 1 can be manufactured inexpensively and easily manufactured despite its high performance.

Further, in the prior art, it was necessary to increase the processing accuracy of the metal seal or to set a sufficient seal length as a measure for preventing the thrust characteristic from deteriorating. Basically there is no need. Therefore, the use of the fluid pressure sealing mechanism does not go against the simplification of manufacturing and the reduction of manufacturing cost.

(4) Rod 4 in this cylinder 1
Has a substantially quadrangular prism shape, that is, a non-circular shape. For this reason, the rod 4 cannot rotate freely in the rod insertion hole 3 and is prevented from rotating. Therefore, there is no fear that the semiconductor chip 5 will rotate carelessly during vacuum suction and cause a displacement, and in that respect, it is suitable as a pressing device in a die bonder.

The first and second steps 41, 42
Are formed only on one of the four outer peripheral surfaces S1 to S4, and therefore, the number of processing portions at the time of manufacturing the rod 4 is minimized. This contributes to further reduction in manufacturing cost and simplification of manufacturing.

(5) Porous body 3 as a fluid pressure sealing mechanism
Reference numeral 2 also serves as a bearing member for supporting the rod 4 in a non-contact manner. For this reason, the rigidity of the bearing as a whole is higher than in a configuration including only the porous bodies 15 and 16, and the cylinder 1 can withstand a larger lateral load.
Further, with such a configuration, it is not necessary to separately arrange the third bearing member, so that an increase in the number of components can be prevented, and the manufacturing cost can be reduced.

(6) Cylinder system C1 of this embodiment
Since the pressure action chambers 27 and 28 are independent of each other, it is easy to arbitrarily set the magnitude relationship of the effective pressure receiving areas of the step portions 41 and 42 corresponding thereto. Here, the effective pressure receiving area of the first step portion 41 is set to be considerably larger (specifically, five times) than the effective pressure receiving area of the second step portion 42. Therefore, according to such a setting, a thrust for drive control smaller than the thrust for eliminating its own weight can be provided to the rod 4. Accordingly, fine pressure adjustment in a narrow range is possible, and the driving of the rod 4 can be controlled with higher accuracy. For this reason, the semiconductor chip 5 can be pressed against the die area with extremely high pressing force, and the semiconductor chip 5 can be securely bonded to the die area without being damaged. That is, there is no excess or deficiency in the pressing force.
Of course, peeling of the semiconductor chip 5 and the like can be avoided beforehand, so that the reliability and performance of the manufactured semiconductor can be improved.

(7) The cylinder system C1 of the present embodiment
In the embodiment, the first and second step portions 41 and 42 are both formed so as to face the lower end side which is the protruding end side of the rod 4. When the rod 4 is formed in this manner, the direction of the thrust for eliminating its own weight and the direction of the thrust for drive control can be made the same.

Further, as compared with the case where the direction of the thrust for eliminating the self-weight and the direction of the thrust for drive control are opposite, the structure becomes simpler and the manufacturing becomes easier. That is,
This is because it is not necessary to provide a structure in which the lower half is provided at a position shifted from the center line of the upper half in manufacturing the rod 4, and the assembly into the rod insertion hole 3 is also easy. In addition, it is possible to provide a rod structure that is excellent in right and left weight balance.

(8) The die bonder of the present embodiment is provided with a transfer pressing mechanism having a cylinder system C1 using the air bearing cylinder 1 as a component. Therefore, after transporting the semiconductor chip 5 vacuum-adsorbed to the jig 6 attached to the rod 4 capable of high control accuracy, the semiconductor chip 5 can be pressed with high precision against the die area. Therefore, the semiconductor chip 5 can be securely bonded to the bonding surface without damage or the like, and the manufactured semiconductor has high reliability and high performance.

(9) In the present embodiment, as a bearing member for ejecting pressurized air to support the rod 4 in a non-contact manner,
The porous bodies 15, 16, 32 having fine pores are used. Therefore, pressurized air is applied to the porous bodies 15, 16, 32.
Are uniformly and uniformly ejected from the inner surface toward the outer peripheral surface of the rod 4. Therefore, the rod 4 and the porous bodies 15, 16,
Even if the clearance with the rod 32 is small, the possibility that the rod 4 slides on the porous bodies 15, 16, 32 is low.
Eccentricity can be suppressed.

The embodiment of the present invention may be modified as follows. The air bearing cylinder 51 in the cylinder system C2 of another example shown in FIG. 5 employs the following configuration. The description of the configuration common to the above embodiment is omitted, and only different points will be described. A lid 52 is provided on the upper end surface of the cylinder block 2A constituting the cylinder 51 via a rubber cushion 53. Therefore, the rod insertion hole 3 is in a non-penetrating state. A flange 54 is provided on the upper end surface of the rod 4A via a rubber cushion 55. The lower surface of the outer peripheral portion of the flange 54 housed in the rod insertion hole 3 has a stopper step 56 formed on the inner peripheral surface of the rod insertion hole 3.
Can be abutted. At this time, the impact is cushioned by the rubber cushion 55.

As long as the condition that the pressurized air is ejected to the rods 4 and 4A is satisfied, it is permissible to use a fluid sealing mechanism other than the porous body 32. Further, the fluid pressure seal mechanism does not necessarily have to double as the bearing member.

The pressurized air may be supplied to a fluid pressure sealing mechanism such as the porous body 32 by a system different from the porous bodies 15 and 16. The first and second steps 41 and 42 are connected to the rods 4 and 4
It is also possible to form a positional relationship that is not on the opposite surface side with respect to the center of A, for example, on adjacent surfaces.

In each of the above-described embodiments, the example in which the porous members 15 and 16 as the bearing members are provided at two upper and lower locations separated from each other along the longitudinal direction of the rod 4 has been described. On the other hand, only one porous body 15 (or 16) may be used, and the other 16 (or 15) may be omitted.

The rods 4 and 4A are not limited to the quadrangular prism shape, but may be a polygonal prism shape such as a hexagonal prism shape. A configuration in which the porous bodies 15, 16, 32, which are bearing members, are provided on the rods 4, 4A instead of the cylinder blocks 2, 2A is also acceptable. In this way, it is easy to make the entire cylinders 1 and 51 slimmer.

The jig 6 for vacuum suction illustrated in each of the above embodiments has one through hole as a structure for sucking an object to be sucked such as the semiconductor chip 5 or the like. On the other hand, a porous body may be interposed in the opening of the through hole of the jig 6, and the surface (lower surface) of the porous body may be used as the suction surface of the semiconductor chip 5. This makes it difficult for the vacuum pressure to act locally on the semiconductor chip 5, thereby preventing the semiconductor chip 5 from being deformed or damaged.

The first and second step portions 41 and 42 are
Both of them do not necessarily need to be formed so as to face the lower end side which is the protruding end side of the rod 4, and one of them may be formed so as to face the upper end side of the rod 4.

The effective pressure receiving area of the first step portion 41 is as follows:
Of course, a configuration in which the effective pressure receiving area of the second step portion 42 is set smaller than the effective pressure receiving area may be employed. In the case of the embodiment, the regulator R3 capable of manually adjusting the set pressure is provided on the pipe L7. Instead of the regulator R3, for example, the above-described regulator R1 and electropneumatic regulator R2 may be provided.

In the above embodiments, the cylinder systems C 1, C 2 including the air bearing cylinders 1, 51
Has been described as an example using a pressing and conveying mechanism in a bonding head of a die bonder. Instead, the cylinder systems C1 and C2 of the present invention may be applied to an apparatus used in another semiconductor manufacturing process such as a silicon wafer cleaning machine. Further, the systems C1 and C2 may be applied to other devices unrelated to the semiconductor manufacturing process.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) A cylinder block having a rod insertion hole, which is inserted into the rod insertion hole so as to be drivable along the longitudinal direction of the cylinder block, with the protruding end side to which the rod attaching member is attached facing downward. A rod, and a bearing member provided on an inner wall surface of the rod insertion hole and supporting the rod in a non-contact manner by ejecting pressurized air to the rod; A first pressure acting portion for providing a thrust for eliminating the own weight and a second pressure acting portion for providing a thrust for driving and controlling the rod are formed on an outer peripheral surface of the rod, and the rod is inserted through the rod. Among the two independent pressure action chambers formed between the inner wall surface of the hole and the outer peripheral surface of the rod, the first pressure action section is disposed in the first pressure action chamber and the first port is connected to the first pressure action section. An air bearing cylinder, in which control air can be supplied thereto via a second pressure action chamber, and the control air can be supplied thereto through a second port. The first and second pressure acting portions are arranged stepwise along the longitudinal direction of the rod, and a fluid pressure seal mechanism for injecting pressurized air to the rod is disposed between the two pressure acting chambers. An air bearing cylinder characterized by:

(2) In the technical idea 1, the rod is a vacuum suction rod having a vacuum passage, the rod attachment member is a jig for holding an object to be suctioned on the rod, and the cylinder is a cylinder. The block is provided with a vacuum port corresponding to an outer peripheral opening of the vacuum path. Therefore, according to the invention described in the technical idea 2, by performing the evacuation through the evacuation port and the evacuation passage, the object to be adsorbed is attached to the jig attached to the protruding end of the evacuation rod. Is held. An air bearing cylinder having such a structure is suitable for use as a pressing device in, for example, a die bonder.

(3) The air bearing cylinder described in the technical concept 2 is a constituent element, and the semiconductor chip is vacuum-adsorbed to the rod-attached member attached to the projecting end side of the rod in the cylinder. A semiconductor manufacturing apparatus provided with a transfer pressing mechanism for transferring and pressing a bonding surface. According to the invention described in the technical idea 3, after the semiconductor chip vacuum-adsorbed to the rod attachment member attached to the rod capable of high control accuracy is transported,
The semiconductor chip can be pressed against the bonding surface with high accuracy. Therefore, the semiconductor chip can be securely bonded to the bonding surface without damage or the like, and the manufactured semiconductor also has high performance.

[0079]

As described in detail above, according to the first aspect of the present invention, it is possible to provide an air bearing cylinder which is inexpensive, easy to manufacture, and has excellent thrust characteristics.

According to the second aspect of the present invention, the manufacturing cost is further reduced and the manufacturing becomes easier. According to the third aspect of the invention, it is possible to improve the load resistance and prevent the number of parts from increasing.

[Brief description of the drawings]

FIG. 1 is a sectional view of an air bearing cylinder according to an embodiment of the present invention.

FIG. 2 is a perspective view of a rod of the cylinder.

FIG. 3A is a graph showing a relationship between a rod displacement and a pressure in a pressure action chamber in the cylinder of the embodiment;
(b) is a graph showing the relationship between the rod displacement and the pressure in the pressure action chamber in the conventional cylinder.

FIG. 4A is a graph showing the relationship between the pressure in the pressure working chamber and the thrust in the cylinder of the embodiment, and FIG. 4B is a graph showing the relationship between the pressure in the pressure working chamber and the thrust in the conventional cylinder. Graph.

FIG. 5 is a cross-sectional view of another example of an air bearing cylinder.

FIG. 6 is a sectional view of a conventional air bearing cylinder.

FIG. 7 is a sectional view of a conventional air bearing cylinder.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

[Explanation of symbols]

1, 51: air bearing cylinder, 2, 2A: cylinder block, 3: rod insertion hole, 4, 4A: rod, 1
5, 16 bearing member, 25 first thrust port as first port, 26 second thrust port as second port, 27 first pressure action chamber, 28 second pressure Working chamber 32, porous body as fluid pressure sealing mechanism, 4
Reference numeral 1 denotes a first step portion as a first pressure acting portion, 42 denotes a second step portion as a second pressure acting portion, S1, S2, S
3, S4: outer peripheral surface of the rod.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H081 AA02 AA05 BB03 CC20 DD13 EE03 EE20 HH04 3J102 AA02 BA09 CA16 EA02 EA06 EA18 EA22 EB07 FA08 GA01

Claims (3)

[Claims] 1. A cylinder block having a rod insertion hole, a rod drivably inserted into the rod insertion hole along a longitudinal direction of the cylinder block, and a rod provided on an inner wall surface of the rod insertion hole. A bearing member for supporting the rod in a non-contact manner by ejecting pressurized air, and a first pressure acting portion for providing a thrust for at least eliminating the weight of the rod and drive control of the rod. A second pressure acting portion for providing a thrust force for forming a pressure is formed on the outer peripheral surface of the rod, and two independent pressure acting chambers formed between the inner wall surface of the rod insertion hole and the outer peripheral surface of the rod are formed. The first pressure action section is disposed in a first pressure action chamber, and control air can be supplied thereto through a first port, and the second pressure action section is supplied to a second pressure action chamber. Distribute the department And an air bearing cylinder capable of supplying control air thereto through a second port, wherein the first and second pressure acting portions are arranged stepwise along the longitudinal direction of the rod, and An air bearing cylinder, wherein a fluid pressure seal mechanism for ejecting pressurized air to the rod is disposed between the pressure action chambers. 2. The rod according to claim 1, wherein the rod has a substantially prismatic shape.
2. The air bearing cylinder according to claim 1, wherein the second pressure acting portion is formed only on one of a plurality of rod outer peripheral surfaces. 3. 3. The air bearing cylinder according to claim 1, wherein the fluid pressure sealing mechanism also serves as a bearing member for supporting the rod in a non-contact manner.