JP3320896B2 - Check valve and liquid discharge device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve for allowing a liquid to flow in one direction and blocking the flow in the opposite direction, and a liquid discharge device using the check valve.

[0002]

2. Description of the Related Art There are various types of check valves used to permit the flow of a fluid in a passage in only one direction and prevent the flow in the opposite direction. On the other hand, a reciprocating member that reciprocates in the axial direction is provided in a pump chamber formed in a cylindrical housing, and by moving the reciprocating member backward, liquid from the liquid storage tank flows into the pump chamber and moves forward. In some cases, a liquid ejection device that supplies the liquid in the pump chamber to the liquid ejection nozzle by using the above-described method is used as a liquid application pump. In this case, a check valve is used for each of a passage connecting the discharge nozzle and the pump chamber and a passage connecting the liquid storage tank and the pump chamber.

[0003]

When a photoresist liquid is applied to the surface of a semiconductor wafer by using a pump of this type, if the resist liquid stays at a check valve portion constituting the pump, the resist is removed. There is a risk that the liquid will deteriorate and it will not be possible to form an element pattern on the semiconductor wafer with good yield.

FIGS. 7A and 7B are views showing a check valve developed for use in a pump for applying a resist solution, which is formed by a first support member 1 and a second support member 2. FIG. The valve housing 5 provided in the mounting hole 3 provided through the sleeve 4 includes a cylindrical portion 7 having a top wall portion 6 and a valve seat 8. The valve seat 8 is formed with an inflow-side port 8a that communicates with the liquid passage 11 formed in the first support member. An accommodation chamber 7a for accommodating the spherical valve element 9 is formed in the cylindrical portion 7, and four liquid guide holes 7b penetrating through the top wall portion 6 are formed in the cylindrical portion. Is connected to a liquid passage 12 formed in the second support member 2 via a liquid guide hole 7b. Reference numeral 4a indicates a seal member.

When the flow of the resist solution is controlled by using the check valve having such a structure, the resist solution stays in a portion indicated by a dot in FIG. When the liquid pool M is formed, the resist liquid in that part stays without flowing and deteriorates,
It is ejected as foreign matter. When a resist solution containing foreign matters is applied to a semiconductor wafer, the yield of products is reduced when manufacturing the semiconductor wafer.

In particular, if there is a sharp corner portion in the check valve, the resist solution is likely to stay.

[0007] It is an object of the present invention to provide a check valve which prevents the accumulation of liquid.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0009]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the check valve according to the present invention comprises a valve housing chamber for housing a spherical valve element movably in the vertical direction, an inflow-side passage for supplying liquid from below into the valve housing chamber, and a valve housing. An outlet passage for guiding liquid from the chamber upwards has a valve housing. The valve accommodating chamber has a valve seat at the bottom, a spherical concave surface corresponding to the valve at the upper end, and a valve guide hole for setting a vertical movement stroke of the valve. The outlet passage and the valve housing chamber communicate with each other through an opening extending from the valve body guide hole to the concave surface of the valve housing chamber, and the valve body that comes into contact with the concave surface by the liquid flowing into the valve housing chamber from the inflow side passage is a valve. The liquid in the storage chamber is guided into the outflow passage.

In the check valve of the present invention, the valve accommodating chamber may be formed concentrically with the inflow side passage in the up-down direction or may be formed to be inclined, and the outflow side passage may be formed in parallel with the valve accommodating chamber. An opening is formed from the valve body guide hole of the valve storage chamber to the concave surface by tilting.

Further, the liquid discharging apparatus of the present invention has a pump housing provided with a reciprocating member which reciprocates in the pump chamber in the axial direction, and reciprocates the reciprocating member by communicating the liquid storage tank with the pump chamber. A first passage for guiding the liquid in the liquid storage tank to the pump chamber during movement, and a second passage for guiding the liquid in the pump chamber to the discharge nozzle when the reciprocating member moves forward by connecting the liquid discharge nozzle to the pump chamber. And a check valve having the above-described structure.

[0013]

In the check valve having the above-described structure, when the valve body moves upward toward the concave surface, the valve body guides the liquid located above the valve body into the outflow-side passage. Thus, the liquid is prevented from staying in the check valve, and the liquid is smoothly guided to the outside from the check valve.

Further, by inclining the valve accommodating chamber or inclining the outflow-side passage, the portion of the valve element guide hole and the concave portion can be used without increasing the inner diameter of the valve element guide hole in the valve accommodating chamber. Thus, an opening can be formed. And, when the valve body opens the valve seat, it has a function of guiding the liquid in the valve body guide hole to the outside, so that the simple structure does not generate a liquid stagnation portion and smoothly. The liquid can be guided to the outlet passage.

In a liquid discharge apparatus using a check valve having the above structure, even a liquid having a relatively high viscosity, such as a resist liquid, can be reliably and smoothly supplied to the outside without stagnation. Can be discharged.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a check valve 10 according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of the valve housing 13. The valve housing 13 includes a lower block 14 and an upper block 15 joined to the lower block 14, and has a cylindrical outer peripheral surface. The valve housing 13 is mounted in a mounting hole 3 formed in the first support member 1 and the second support member 2 via a cylindrical sleeve 4.

A valve housing chamber 17 is provided in the valve housing 13 for housing a valve element 16 having a spherical shape and a diameter R so as to be vertically movable.
The lower end of the valve storage chamber 17 is
4 is communicated with the inflow-side passage 21 formed. The inflow side passage 21 has an inner diameter d ₁ set to be smaller than the diameter R of the valve body 16, and has an inner diameter substantially equal to the inner diameter d _1, and is formed in the first support member 1. And the inflow side passage 21 communicate with each other, so that the liquid guided by the fluid passage 11 flows into the valve chamber 17 from below through the inflow side passage 21. Various materials such as metal and ceramic can be used as the material of the valve body 16.

An outlet passage 22 is further formed in the valve housing 13, and the outlet passage 22 is connected to the second support member 2.
, And communicates with the liquid passage 12 formed in the valve housing chamber 1.
7 passes through the outflow passage 22 and the upper liquid passage 1
You will be guided to 2. The inner diameter d ₂ of the outflow-side passage 22 is set to be substantially the same as the inner diameter d ₁ of the inflow-side passage 21 in the case illustrated.

The lower end of the valve chamber 17 has a spherical surface 23, and an annular valve seat 24 is formed in the valve housing 13 at the boundary between the spherical surface 23 and the inflow side passage 21. I have. The flow of the liquid from the outflow side passage 22 to the inflow side passage 21 is blocked by the valve body 16 abutting on the valve seat portion 24.

A spherical concave surface 25 corresponding to the valve body 16 is formed at the upper end of the valve accommodating chamber 17. The concave surface 25 and the spherical surface 23 are connected to each other so that the vertical stroke of the valve body 16 is increased. Is provided in the valve housing chamber 17. The inner diameter D of the valve body guide hole 26 is set slightly larger than the diameter of the valve body 16.

[0022] As described above, since the diameter d ₂ of the diameter d ₁ and an outflow side passage 22 of the inlet-side passage 21 than the diameter R of the valve body 16 has a smaller diameter, the valve body 16 flows into the lower It does not fall into the side passage 21 and does not enter the outflow passage 22 due to the liquid.

The outlet passage 22 communicates with the valve chamber 17 at the opening 27, and the opening 27 extends from the valve guide hole 26 of the valve chamber 17 to the vicinity of the vertex of the concave surface 25. In the case shown in the figure, the outflow side passage 22 is inclined with respect to the valve accommodation chamber 17 so that
The outflow-side passage 22 is formed so as to be shifted from the valve housing chamber 17. Thus, the outflow side passage 22 and the valve housing chamber 17
Opening 2 reaching from the valve body guide hole 26 to the concave surface 25
As a result, the inner diameter D of the valve body guide hole 26 is made slightly larger than the diameter R of the valve body 16 so that the flow area of the liquid from the inflow side passage 21 to the outflow side passage 22 is reduced. It can be sufficiently secured. The lower end surface 28 of the outflow side passage 22 has a concave shape.

In the case shown, a spherical surface 23 is formed on the lower block 14, and this spherical surface 23 and the inflow side passage 21 are formed.
The valve seat 24 is formed at the boundary with the spherical surface 2.
3 and the valve seat 24 are formed by cutting or molding the lower block 14. Similarly, the valve body guide hole 26 and the concave surface 25 are formed by cutting or molding the upper block 15. The vertical length of the valve body guide hole 26 is set in relation to the opening area of the opening 27 so that the liquid flow area is sufficiently secured by the vertical movement of the valve body 16.

In the check valve having such a structure, when the pressurized liquid is supplied from the liquid passage 11 into the inflow side passage 21, the pressure causes the valve body 16 to move in a dashed line in FIG. It is moved upward as shown and separates from the valve seat 24. As a result, the liquid in the inflow-side passage 21 flows into the valve accommodating chamber 17, then flows out into the outflow-side passage 22 through the opening 27, and is guided to the liquid passage 12.

At this time, the liquid filled in the valve accommodating chamber 17 is pressed against the concave surface 25, is further moved upward, and is surely discharged to the outflow side passage 22 by the valve body 16 which comes into contact with the concave surface 25. Will be. Further, the liquid filled in the lower end portion of the outflow side passage 22 is guided to the liquid passage 12 through the outflow side passage 22 because the lower end surface 28 of the outflow side passage 22 has a concave shape. In this way, the liquid in the valve housing 13 is reliably guided into the liquid passage 12 without the liquid staying in the valve housing 13.

On the other hand, when the pressurized liquid is supplied from the liquid passage 12 into the outflow-side passage 22, the valve body 16 comes into contact with the valve seat 24 due to the pressure and the weight of the valve body 16. The flow of the liquid from the valve storage chamber 17 to the inflow-side passage 21 is blocked.

FIGS. 2 to 4 are cross-sectional views showing a check valve according to another embodiment of the present invention, wherein members common to the members in the above embodiment are denoted by the same reference numerals.

In the check valve 10 shown in FIG. 1, the liquid passages 11 and 12 are formed concentrically with each other and the outflow-side passage 22 is formed to be inclined. In the illustrated check valve, the liquid passages 11 and 12 are formed so as to be shifted in the horizontal direction, and the outflow-side passage 22 is formed substantially in the vertical direction. As described above, by shifting the outflow-side passage 22 in the horizontal direction, the opening 27 that extends from the valve element guide hole 26 to the vicinity of the vertex of the concave surface 25 is formed without increasing the inner diameter of the valve storage chamber 17. ing.

In the check valve 10 shown in FIG.
An opening 27 is formed from the connection between the spherical surface 23 of the valve accommodating chamber 17 and the valve element guide hole 26 to the top of the concave surface 25. Therefore,
In this case, the outflow side passage 22 does not have the concave lower end surface 28 shown in FIGS. 1 and 2.

In the check valve 10 shown in FIG.
Is in the vertical direction as in the case shown in FIGS. On the other hand, the outflow side passage 22 is inclined in a direction approaching the center line of the inflow side passage 21, that is, inward in the case shown in FIG. 1, whereas the check valve shown in FIG. It is formed in a direction away from the center line of the passage 21, that is, inclined outward. Therefore, the lower end surface 28 having a concave shape as shown in FIGS. 1 and 2 is not formed in the outflow side passage 22 shown in FIG.

The check valve shown in FIGS. 3 and 4 does not have the concave lower end surface 28 of the check valve shown in FIGS. 1 and 2, so that the flow of liquid in the check valve is smoother. And the stagnation of the liquid inside is further reduced.

In each of the check valves, a valve element 1
The valve 6 is used to open and close the passage by moving in the vertical direction. However, as long as the opening and closing function due to the vertical movement of the valve body 16 is not substantially impaired, the check valve is turned at a certain angle. You may make it use it inclining.

FIG. 5 is a sectional view showing a liquid discharge device having the above-described check valve 10. This liquid discharge device has a pump housing 32 in which a pump chamber 31 is formed. Is mounted with a support block 33 having a first passage 30a and a support block 34 having a second passage 30b.
Reference numerals 3 and 34 constitute a part of the pump housing 32. Each of the passages 30a and 30b communicates with the pump chamber 31.

A liquid supply hose 35 is connected to the first passage 30a, and the resist solution 37 stored in the resist solution storage tank 36 is guided to the first passage 30a by the liquid supply hose 35. A resist liquid discharge nozzle 39 is connected to the second passage 30 b by a liquid supply hose 38, and the resist liquid 37 is applied to the semiconductor wafer 40 by the resist liquid discharge nozzle 39.

In the pump chamber 31, a bellows 41 formed of, for example, fluorine resin and having a distal end portion 41a, a bellows-like portion 41b, and a proximal end portion 41c fixed to the pump housing 32 is provided so as to be extendable and contractible. Tip 41a
Constitutes a reciprocating member. By compressing the bellows 41 in the axial direction, the resist solution 37 in the resist solution storage tank 36 is taken into the pump chamber 31, and is expanded to pressurize the pump chamber 31 so that the resist solution 37 is discharged from the resist solution discharge nozzle 39. It is discharged and applied to the semiconductor wafer 40.

A drive section 42 for extending and retracting the bellows 41 in the axial direction is fixed to the pump housing 32 via a connecting member 43. The drive section 42 includes a base 44 and a front support plate fixed thereto. 45 and a rear support plate 46. Inside the bellows 41, a drive shaft 47 is provided concentrically with the center axis of the bellows 41, and the drive shaft 47 is
3 and the front support plate 45. A nut 48 is attached to the rear end of the drive shaft 47, and a ball screw 49 screwed to the nut 48 is attached to a rear support plate 46.
It is rotatably attached to.

A step motor 51 is mounted on the rear support plate 46, and a pulley 52 fixed to a main shaft of the step motor 51 and a pulley 5 fixed to a ball screw 49.
3, a timing belt 54 is stretched. Therefore, by driving the step motor 51 in both the forward and reverse directions, the bellows 41 is driven to expand and contract. In order to guide the nut 48 in the axial direction, the front and rear support plates 4 are used.
A guide rod 55 is mounted between the fifth and the fifth 46.

In the first passage 30a, two check valves 10a having the same structure as the check valve 10 shown in FIG. 1 are arranged in series. A check valve 10b having the same structure as the illustrated check valve 10 is arranged. The liquid discharge device is installed such that the check valves 10a and 10b are vertically opened and closed so that the valve body 16 moves up and down. The first in FIG.
The support member 1 corresponds to the support block 33 for the lower one of the check valves 10a in FIG.
b corresponds to the pump housing 32. Also,
The second support member 2 in FIG. 1 corresponds to the support block 34 for the check valve 10b, and corresponds to FIG.
, The upper one corresponds to the pump housing 32.

In the liquid discharging apparatus having such a structure, when the step motor 51 is driven, the rotation of the main shaft is transmitted to the ball screw 49 via the timing belt 54, The concentric drive shaft 47 is reciprocated in the axial direction. This reciprocation of the drive shaft 47 causes the bellows 41 to expand and contract. When the bellows 41 contracts in the axial direction, the pump chamber 31 has a negative pressure, and a predetermined amount of the resist solution 37 in the resist solution storage tank 36 is supplied into the pump chamber 31. At this time, the two check valves 10a provided in the first passage 30a
Is that the respective valve elements 16 are moved upward and the resist solution 3
7 flows are allowed. On the other hand, the check valve 10 b provided in the second passage 30 b prevents the resist solution 37 in the liquid supply hose 38 from flowing back into the pump chamber 31 due to the valve body 16 abutting against the valve seat 24.

When the bellows 41 extends in the axial direction,
The pump chamber 31 is pressurized, and the resist liquid 37 in the pump chamber 31 passes through the check valve 10 b and is guided to the resist liquid discharge nozzle 39 via the liquid supply hose 38. At this time, the backflow of the resist solution from the pump chamber 31 into the resist solution storage tank 36 is prevented by the two check valves 10a. Thereby, the bellows 41
The resist liquid is applied to the semiconductor wafer in an amount corresponding to the forward stroke of the front end portion 41a.

When the resist solution is supplied by the expansion and contraction operation of the bellows 41, the check valves 10
In the steps a and b, even if the resist liquid has a relatively high viscosity, the stagnation of the resist liquid is prevented, so that it is possible to prevent the adverse effect in the manufacture of the semiconductor wafer due to the deterioration of the resist liquid.

FIG. 6 is a sectional view showing a main part of a liquid discharge apparatus according to another embodiment of the present invention. Members common to those in the liquid discharge apparatus shown in FIG. 5 are denoted by the same reference numerals. ing.

The pump housing 32 of the liquid discharge device
Has a cylindrical portion 32a and a head portion 32b attached to the tip of the cylindrical portion 32a. The cylindrical portion 32a is provided with a diaphragm 56 formed of rubber or resin. A drive shaft 47 for reciprocating is mounted on the drive shaft. This diaphragm 5
The pump chamber 31 is formed between 6 and the head part 32b. The structure of the drive means for reciprocating the drive shaft 47 in the axial direction is the same as the structure of the liquid ejection apparatus shown in FIG.

Two support blocks 33 and 34 are attached to the head portion 32b, each of which forms a part of the pump housing 32, and the first passage 30a and the first passage 30a respectively formed in the pump housing 32. Check valves 10a and 10b are provided in the two passages 30b.

Each of the check valves 10a and 10b has substantially the same structure as the check valve shown in FIG. 3, and the head portion 32b of the check valve 10a forms the upper block 15 in FIG. , The lower block 14 is provided on the support block 33.
The lower block 14 may be constituted by the support block 33 without using the above.

As for the check valve 10b, the support block 34 forms the upper block 15 in FIG.
The upper block 34 is attached to the lower block 14 in FIG.
Are provided. However, the lower block 14 may be constituted by the head portion 32b without using the lower block 14. By using the member constituting the pump housing 32 also as the valve housing of the check valve, the sleeve in the above-described embodiment can be omitted.

In the liquid discharge device shown in FIG. 5, two check valves 10a are arranged in the first passage 30a.
In the liquid ejection device shown in FIG.
Although a is arranged, this number can be set arbitrarily. The check valve 1 is also provided for the second passage 30b.
The number of 0b can be set to an arbitrary number.

In each of the liquid discharge devices,
Any type of check valve shown in FIGS. 1 to 4 may be used.

As described above, the invention made by the inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say.

For example, the liquid discharge apparatus shown in FIG. 5 is for applying a resist liquid to a semiconductor wafer. However, the present invention is not limited to the case where the resist liquid is applied, and prevents liquid from staying in a check valve. If necessary, the present invention can be applied to discharging any liquid. In each of the liquid discharge devices shown in FIGS. 5 and 6, the bellows 41 is driven by the step motor 51 via the ball screw 49. However, the bellows 41 is driven using a pneumatic cylinder. You may do it.

Further, in each of the liquid discharge devices shown in FIGS. 5 and 6, the check valves 10a and 10b are provided in the pump housing 32. Check valves 10a,
10b may be provided. As the reciprocating member, a piston or the like may be used in addition to the bellows 41 as shown in FIG. 5 and the diaphragm 56 as shown in FIG.

[0053]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) Since the valve body has the function of preventing the liquid from staying, the liquid flows smoothly in the check valve without the liquid remaining in the check valve.

(2) When the liquid discharge device is configured using a check valve that allows a smooth flow of the liquid, stagnation of the liquid in the liquid discharge device is prevented, and the application of the resist liquid is performed using the liquid discharge device. Even if it is performed, it is possible to perform high-quality liquid application with little dust generation.

(3) The structure of the check valve is simplified, its manufacture is easy, and a low-cost check valve and a liquid discharge device having the check valve can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a check valve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a check valve according to another embodiment of the present invention.

FIG. 3 is a sectional view showing a check valve according to still another embodiment of the present invention.

FIG. 4 is a sectional view showing a check valve according to still another embodiment of the present invention.

FIG. 5 is a sectional view showing a liquid ejection apparatus according to one embodiment of the present invention.

FIG. 6 is a sectional view showing a liquid ejection apparatus according to another embodiment of the present invention.

FIG. 7A is a cross-sectional view showing a check valve which has been developed, and FIG. 7B is a partially cutaway perspective view showing a cylindrical portion shown in FIG. 7A.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st support member 2 2nd support member 3 mounting hole 4 sleeve 10, 10a, 10b non-return valve 11, 12 liquid passage 13 valve housing 14 lower block 15 upper block 16 valve body 17 valve storage chamber 21 inflow side passage 22 Outflow side passage 23 Spherical surface 24 Valve seat 25 Concave surface 26 Valve guide hole 27 Opening 28 Lower end surface 30a First passage 30b Second passage 31 Pump chamber 32 Pump housing 33,34 Support block 35,38 Liquid supply hose 36 Resist Liquid storage tank (liquid storage tank) 37 Resist liquid (liquid) 39 Resist liquid discharge nozzle (liquid discharge nozzle) 40 Semiconductor wafer 41 Bellows 41a Tip (reciprocating member) 42 Drive unit 47 Drive shaft 48 Nut 49 Ball screw 51 Step Motor 52, 53 Pulley 54 Timing belt 55 Guide rod 6 diaphragm (reciprocating member)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-139565 (JP, A) JP-A-6-159235 (JP, A) JP-A-2-3789 (JP, A) 98233 (JP, U) JP-A 61-52772 (JP, U) JP-A 61-202763 (JP, U) JP-B 48-27644 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 15/00-15/20 F04B 21/00 F04B 39/00

Claims (3)

(57) [Claims] 1. A valve accommodating chamber for accommodating a spherical valve body movably in a vertical direction, an inflow-side passage for supplying a liquid from below into the valve accommodating chamber, and a liquid from the valve accommodating chamber upward. A valve housing formed with an outflow-side passage for guiding; a valve seat portion that is in contact with the valve body at a bottom portion of the valve housing chamber; and an upper end portion of the valve housing chamber corresponding to the valve body. While forming a spherical concave surface, a valve body guide hole for connecting the valve seat portion and the concave surface and setting a vertical movement stroke of the valve body is formed with an inner diameter slightly larger than the diameter of the valve body. An opening reaching the concave surface from the valve body guide hole of the valve chamber communicates the outflow side passage with the valve chamber, and the concave surface is formed by a liquid flowing into the valve chamber from the inflow side flow path. The valve body abutting the liquid causes the liquid in the valve chamber to flow through the valve housing. A check valve characterized in that it is guided into an outlet passage. 2. The valve accommodating chamber is formed concentrically with the inflow-side passage in the up-down direction or inclined, and the outflow-side passage is formed in parallel with or inclining with the valve accommodation chamber. 2. The check valve according to claim 1, wherein the opening is formed from the valve body guide hole of the valve storage chamber to the concave surface. 3. A pump housing having a pump chamber and provided with a reciprocating member reciprocating in the axial direction in the pump chamber, and a liquid storage tank communicating with the pump chamber when the reciprocating member retreats. A first passage for guiding the liquid in the liquid storage tank to the pump chamber; and a liquid discharge nozzle communicating with the pump chamber to guide the liquid in the pump chamber to the discharge nozzle when the reciprocating member moves forward. A liquid discharge device comprising: a second passage; and the check valve according to claim 1 provided in the first passage and the second passage.