JPH0810399Y2 - Suck back valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a suck back valve, and in particular, it is arranged, for example, between a nozzle for applying a resist liquid to a semiconductor wafer and a resist liquid supply source. The technology is effective when applied to suck back valves.

[Conventional technology]

Some suck back valves include a flow path for control fluid such as resist liquid, a diaphragm for sucking back when the pressure receiving surface is exposed in the control fluid flow path, and a piston for displacing the diaphragm. .

For example, such suck-back valve is interposed between a nozzle for applying a resist solution to a semiconductor wafer and a supply source of the resist solution, and changes the volume of the control fluid flow path by the displacement of the diaphragm. This prevents unnecessary resist liquid from dropping from the nozzle onto the semiconductor wafer.

[Problems to be solved by the device]

However, in the suck-back valve having the above-described structure, the pressure-receiving surface of the diaphragm that performs suck-back is located outside the inner peripheral wall surface along the flow direction of the control fluid flow path, so that the pressure-receiving surface of the diaphragm and the control fluid are A dead space is formed between the inner peripheral wall surface along the flow direction of the working channel, and the dead space is liable to cause foam accumulation or liquid accumulation.

Therefore, the suck back amount becomes unstable due to the bubble accumulation, or the control fluid such as the resist liquid is deteriorated and contaminated due to the liquid accumulation.

An object of the present invention is to provide a suck back valve capable of reliably preventing foam accumulation and liquid accumulation.

[Means for solving the problem]

The structure of the suck back valve of the present invention is a suck back valve including a control fluid flow path and a diaphragm for sucking back when a pressure receiving surface is exposed in the control fluid flow path. A structure in which the pressure receiving surface is located on substantially the same plane as the inner peripheral wall surface along the flow direction of the control fluid channel, or is located so as to project from the inner peripheral wall surface into the control fluid channel. It was done.

In this case, it is possible to adopt a structure in which the mounting surface of the diaphragm is formed on the outer peripheral side of the pressure receiving surface with a step from the pressure receiving surface.

[Action]

According to the structure of the suck back valve described above, the pressure receiving surface of the diaphragm is located on substantially the same plane as the inner peripheral wall surface along the flow direction of the control fluid flow path, or the control fluid flow is formed from the inner peripheral wall surface. By being positioned so as to project in the passage, a dead space is not formed between the pressure receiving surface of the diaphragm and the inner peripheral wall surface along the flow direction of the control fluid flow passage, so that bubble accumulation due to the dead space or It is possible to reliably prevent the liquid pool.

In this case, if the structure is such that the mounting surface of the diaphragm is formed on the outer peripheral side of the pressure receiving surface with a step difference from the pressure receiving surface, the mounting surface is incorporated into the outside of the flow path for control fluid in the valve and the diaphragm is installed. It is possible to easily and reliably fix the diaphragm in the valve with the above-mentioned effects by fixing the.

[Embodiment 1] FIG. 1 is a sectional view showing a suck back valve which is an embodiment of the present invention.

A cylinder tube 3 is connected to the valve body 2 to which the plate 1 is connected, and a cover 5 is connected to the cylinder tube 3 via a seal member 4 such as an O-ring.

The valve body 2 has control fluid ports 6a, 6 on both sides.
b is opened respectively, and a control fluid channel 6 composed of the control fluid ports 6a and 6b is provided therein.

Both ends of the control fluid channel 6 are formed to have a perfect circular cross section in the vertical plane direction of FIG. 1, and the middle portion of the control fluid channel 6 has a perfect circular cross section in the horizontal plane of FIG. Is formed in.

A diaphragm 7 made of an elastic material or the like is interposed between the valve body 2 and the cylinder tube 3 via a guide washer 8, and a pressure receiving surface 7a of the diaphragm 7 is exposed to the control fluid passage 6. .

The pressure receiving surface 7a of the diaphragm 7 for sucking back is located on substantially the same plane as the inner peripheral wall surfaces along the flow direction at both ends of the control fluid flow path 6, and the pressure receiving surface 7a of the diaphragm 7 and the flow for control fluid flow. The structure is such that no dead space is formed between the passage 6 and the inner peripheral wall surface along the flow direction.

On the outer peripheral side of the pressure receiving surface 7a of the diaphragm 7, a mounting surface 7b of the diaphragm 7 is formed with a step H with the pressure receiving surface 7a, and the diaphragm 7 is sandwiched between the valve body 2 and the guide washer 8 on the mounting surface 7b side. Has been fixed.

The cylinder tube 3 has breather ports on both sides thereof.
9 and 10 are opened respectively, and one breather port 9 communicates with a space above the pressure receiving surface 7a of the diaphragm 7 through a groove 8a having a V-shaped cross section formed on the upper surface of the guide washer 8.

A piston rod 12 having a seal member 11 is slidably passed through an axially penetrating portion of the cylinder tube 3 along the axial direction.

The piston rod 12 has one end connected to the central connecting portion 7c of the diaphragm 7 and the other end connected to the piston 14 having the seal member 13.

The piston 14 is slidably accommodated in the cylinder chamber 15 formed by the cylinder tube 3 and the cover 5 along the axial direction, and the cylinder chamber 15 is housed in the upper chamber 15a and the lower chamber 1
It is divided into 5b.

The breather port 10 is communicated with the lower chamber 15b, and a coil spring 16 is housed therein, and the coil spring 16 urges the piston 14 toward the cover 5.

A working fluid supply / discharge port 17 is opened on one side of the cover 5, and the working fluid supply / discharge port 17 is communicated with the upper chamber 15a.

An adjusting screw 20 having a seal member 18 and a knob 19 is screwed in a penetrating portion on the axial center of the cover 5 so as to be movable back and forth along the axial direction, and the piston is adjusted by adjusting the amount of protrusion of the adjusting screw 20 on the tip side. The suck back amount can be adjusted by adjusting the stroke of 14 and the displacement amount of the pressure receiving surface 7a of the diaphragm 7 (the displacement amount in the vertical direction in FIG. 1).

A lock nut 21 for the adjusting screw 20 is provided on the outer end surface side of the cover 5.

 Next, the operation of this embodiment will be described.

For example, the suck back valve of the present embodiment includes a nozzle (not shown) through which the control fluid channel 6 applies a resist solution or the like to a semiconductor wafer, and a resist solution supply source (not shown).
And is provided so as to be interposed therebetween.

In the suck back valve arranged in this way,
When working fluid such as compressed air is supplied to the upper chamber 15a through the working fluid supply / discharge port 17, the piston 14, the piston rod 12, and the pressure receiving surface 7a of the diaphragm 7 in the state shown in FIG. As shown, the coil spring 16 is displaced to the lower side in the figure against the biasing force.

The resist liquid from the resist liquid supply source (not shown)
In such a state, it is supplied to the nozzle (not shown) through the control fluid flow path 6 of the suck back valve and applied to the semiconductor wafer.

In this case, for example, when there is a fear that unnecessary resist liquid may be dripped on the semiconductor wafer from the tip of the nozzle (not shown), the working fluid in the upper chamber 15a is supplied and discharged for working fluid. Discharge to the outside through port 17.

The piston displaced downward in Fig. 1 due to this discharge
14, the piston rod 12 and the pressure receiving surface 7a of the diaphragm 7 are displaced upward in the figure by the urging force of the coil spring 16, and the displacement of the pressure receiving surface 7a changes the volume of the control fluid passage 6. As a result, unnecessary resist liquid is prevented from being dropped onto the semiconductor wafer from the nozzle (not shown).

The suck back valve of this embodiment is operated in this manner.

In this case, in the present embodiment, the pressure receiving surface 7a of the diaphragm 7 is located on substantially the same plane as the inner peripheral wall surface along the flow direction of the control fluid channel 6, Since no dead space is formed between the pressure receiving surface 7a of the diaphragm 7 and the inner peripheral wall surface along the flow direction of the control fluid flow path 6, it is possible to reliably prevent the accumulation of bubbles and liquid due to the dead space. .

Further, in the diaphragm 7 of this embodiment, the mounting surface 7b is formed on the outer peripheral side of the pressure receiving surface 7a with a step H from the pressure receiving surface 7a,
Since the mounting surface 7b side is sandwiched and fixed by the valve body 2 and the guide washer 8, the diaphragm 7 having the above-mentioned effects can be easily and surely fixed in the valve. You can

[Embodiment 2] FIG. 2 is a sectional view showing a suck back valve according to another embodiment of the present invention with a part thereof omitted.

In the suck back valve according to the second embodiment, the pressure receiving surface 7a of the diaphragm 7 is formed from the inner peripheral wall surfaces along the flow direction at both ends of the control fluid passage 6 to the control fluid passage 6a.
It is located so as to project inside.

In the structure of the second embodiment as well, similar to the structure of the first embodiment, between the pressure receiving surface 7a of the diaphragm 7 and the inner peripheral wall surface along the flow direction of the control fluid channel 6,
Since no dead space is formed, it is possible to reliably prevent the accumulation of bubbles and the accumulation of liquid due to the dead space.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiments 1 and 2 and various modifications can be made without departing from the gist of the invention. Needless to say.

For example, the suck back valves of the above-mentioned Examples 1 and 2 are
It is used by being installed between a nozzle for applying resist liquid etc. to a semiconductor wafer and a resist liquid supply source.
The suck back valve of the present invention is not limited to the use of such a resist solution in a fluid circuit, but can be used in a predetermined fluid circuit of a chemical solution or the like.

In addition, the suck back valve of the first and second embodiments has a single-acting cylinder structure in which the fluid pressure is supplied only to one side of the piston 14 to operate the piston 14. Can have a double-acting cylinder structure in which fluid pressure is alternately supplied to both sides of the piston 14 to operate the piston 14.

In the suck back valve of the first and second embodiments, the breathing port 10 has a structure that can be used by changing to the working fluid supply / discharge port (working fluid supply / discharge port on the lower chamber side). Double-action type by changing the breather port 10 to a working fluid supply / discharge port, replacing the seal members 11 and 13 made of V-type packing with a seal member made of an O-ring, and removing the coil spring 16. The structure can be changed to a cylinder structure.

[Effect of device]

According to the structure of the suck back valve of the present invention, the following effects can be obtained.

(1). The pressure receiving surface of the diaphragm is located on substantially the same plane as the inner peripheral wall surface along the flow direction of the control fluid flow path, or is projected from the inner peripheral wall surface into the control fluid flow path. As a result, no dead space is formed between the pressure receiving surface of the diaphragm and the inner peripheral wall surface along the flow direction of the control fluid flow path, so that it is possible to reliably prevent the accumulation of bubbles and the accumulation of liquid due to the dead space.

(2). Due to the effect of (1) described above, it is possible to reliably prevent destabilization of the suck back amount due to the accumulation of bubbles.

(3). Due to the effect of (1) described above, it is possible to reliably prevent alteration and contamination of the control fluid due to the liquid pool.

(4). In the above case, if the structure is such that the mounting surface of the diaphragm is formed on the outer peripheral side of the pressure receiving surface with a step difference from the pressure receiving surface, the mounting surface is incorporated into the outside of the control fluid channel in the valve. By fixing the diaphragm, it is possible to easily and surely fix the diaphragm in the valve with the effects (1) to (3) described above.

[Brief description of drawings]

FIG. 1 is a sectional view showing a suck back valve according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a suck back valve according to another embodiment of the present invention with a part thereof omitted. 1 ... Plate, 2 ... Valve body, 3 ... Cylinder tube, 4 ... Sealing member, 5 ... Cover, 6 ... Control fluid passage, 6a, 6b ... Control fluid port, 7 ... Diaphragm, 7a ... Pressure receiving surface, 7b ... Mounting surface, 7c ... Connecting part, 8 ... Guide washer, 8a ... Groove, 9,10 ... Breathing port, 11 ... Seal member, 12 ... Piston rod ,13
...... Seal member, 14 ...... Piston, 15 ...... Cylinder chamber,
15a ... upper chamber, 15b ... lower chamber, 16 ... coil spring, 17
…… Work fluid supply / discharge port, 18 …… Seal member, 19 ……
Pick, 20 …… Adjusting screw, 21 …… Lock nut. H ... step.

Claims (3)

[Scope of utility model registration request] 1. A suck back valve comprising a control fluid flow passage and a diaphragm for sucking back by exposing the pressure receiving surface to the control fluid flow passage, wherein the pressure receiving surface of the diaphragm is the control. A suck back valve, which is located on an inner peripheral wall surface along a flow direction of a fluid channel. 2. A suck back valve comprising a control fluid flow passage and a diaphragm for sucking back by exposing the pressure receiving surface to the control fluid flow passage, wherein the pressure receiving surface of the diaphragm is the control. A suck back valve, wherein the suck back valve is positioned so as to project from the inner peripheral wall surface along the flow direction of the fluid flow passage into the control fluid flow passage. 3. The suck back valve according to claim 1, wherein the mounting surface of the diaphragm is formed on the outer peripheral side of the pressure receiving surface with a step difference from the pressure receiving surface.