JPH0634770U - Suckback device for liquid supply device - Google Patents

Abstract

(57) [Summary] [Purpose] Even when supplying a liquid having a large viscous resistance or using a nozzle having a large discharge area, it is possible to reliably prevent liquid dripping from the nozzle. [Structure] An expandable and contractable bellows tube 2 is provided in a flow path 1 for pumping a liquid, the tube 2 is compressed by a compression driver 3 when the liquid is supplied, and when the liquid supply is stopped, the compression is released to expand the bellows tube 2. I did it. [Effect] A large suck back amount can be obtained, and liquid dripping can be reliably prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The suck back device of the present invention is used for a liquid supply device that discharges a high-viscosity liquid from a nozzle and applies it to a substrate, etc.When stopping the discharge of mucus from the nozzle, It is used to prevent dripping (dripping).

[0002]

[Prior art]

As shown in FIG. 9, nitrogen gas (N ₂ gas) is supplied into the pressure tank A to pressurize a high-viscosity liquid such as an adhesive or a polyimide resist in the container B and send it out to the flow path C. There is a conventional liquid supply device that discharges a liquid from a nozzle D to uniformly coat a substrate E such as a semiconductor wafer. A suck back device F that prevents liquid from dripping from the nozzle D when the discharge of the liquid from the nozzle D is stopped is incorporated in this liquid supply device. The main ones of the suck back device F are shown in FIGS. 7 and 8.

In the suck back device shown in FIG. 7, a diaphragm G is installed in the middle of a flow path C for pumping the liquid, and when the liquid is discharged, the diaphragm G is mechanically moved along the flow path C as shown in FIG. The inner volume of the flow passage C is made small by projecting the inside of the flow passage C, and the diaphragm G is mechanically indented outside the flow passage C as shown in FIG. 7B when the liquid discharge is stopped. By increasing the internal volume of C, the liquid in the flow path C and the nozzle D (FIG. 9) is pulled back (sucked back) to prevent liquid dripping.

In the suck back device shown in FIG. 8, the flow path (soft resin tube) C is sandwiched between two plate materials H at the time of liquid discharge and crushed to some extent to reduce the internal volume, and when liquid discharge is stopped. As shown in FIG. 8 (b), the crushing by the two plate materials H is released to increase the inner volume of the flow passage C, so that the liquid in the flow passage C and the nozzle D (FIG. 9) is pulled back. To prevent dripping.

[0005]

[Problems to be solved by the device]

 In the suck back device of FIG. 7, there is a limit to how much the inner volume can be changed by the protrusion and depression of the diaphragm G, and a sufficient suck back amount cannot be obtained. Therefore, when ejecting a liquid with a particularly high viscosity (high viscous resistance) such as a polyimide resist, or when ejecting from a nozzle with a large ejection area such as a band-shaped nozzle, the suckback effect becomes insufficient, It cannot reliably prevent dripping. Moreover, if the liquid drools, the application of the liquid becomes uneven, and in the case of a high-value liquid such as a polyimide resist, the liquid is wasted by the amount dripped, which is uneconomical.

In the suck back device shown in FIG. 8, the change in the internal volume can be made larger than in the case of the diaphragm shown in FIG. 7, but when discharging a highly viscous liquid or when using a nozzle having a large discharging area. Has to widen the width of the plate material H, so that it takes up a lot of space for installation. Further, it is desirable to provide the plate material H as close to the nozzle as possible in order to improve the liquid cut-off due to suck back. However, if the horizontal width of the plate material H 1 is widened as described above, the operating part area is limited and the temperature of the liquid is limited. There was a problem that it became difficult to install the controller near the nozzle.

An object of the present invention is to provide a suck back device capable of reliably preventing liquid from dripping from a nozzle even when supplying a liquid having a large viscous resistance or using a nozzle having a large discharge area. .

[0008]

[Means for Solving the Problems]

 The suck back device for a liquid supply device of the present invention pumps a liquid through the flow path 1 to eject it from the nozzle 50 (FIG. 6), and when the ejection of the liquid is stopped, the liquid is pulled back to eject the nozzle 50 (FIG. 6). In the suck back device for preventing liquid dripping from the), an expandable and contractible bellows tube 2 is provided in the flow passage 1 as shown in FIG. 1, and the tube 2 is compressed in the axial direction when the liquid is supplied. However, the compression drive body 3 that releases the compression when the liquid supply is stopped is connected.

[0009]

[Action]

 In the suck back device for liquid supply device of the present invention, the expandable and contractible bellows tube 2 is axially compressed by the contraction driver 3, and the liquid is supplied to the flow passage 1 in that state, and the liquid is discharged from the nozzle. It If the compression by the compression driver 3 is released when the liquid supply is stopped, the bellows tube 2 expands and its internal volume increases, so that the liquid in the flow path 1 sucks back to the left side in FIG. 1 and liquid dripping is prevented. It

[0010]

【Example】

 An embodiment of the suck back device of the present invention is shown in FIGS. In these figures, 11 is a metal casing, and 1 is a flow path of a metal pipe attached to the casing. Of these two flow paths 1, one is a supply side flow path 12 for supplying the liquid from the tank, and the other one is a delivery side flow path 13 for sending the liquid to the nozzle. These are fixed to the peripheral wall of the housing 11 with nuts, and are further fixed by tightening with screws 15 to a metal support protrusion 14 protruding upward from the bottom surface of the housing 11.

1 to 4 is a resin bellows tube, which is U-shaped in a U-shaped storage groove 22 of a movable base 21 made of hard resin arranged in the housing 11. It is bent and stored.

As shown in FIG. 5, one end 23 of the bellows tube 2 is attached to the bottom surface of the casing 11 and penetrates through a support base 24 made of a hard resin which projects upward, and further the casing 11 By inserting it into the metal supporting part 25 projecting upward from the bottom surface of the above, covering the end part 26 of the supply side flow passage 12 and further tightening the supporting part 25 with the screw 27, It is fixed to the support portion 25.

Further, the other end 28 of the bellows tube 2 is penetrated through a hard resin support base 29 attached to the bottom surface of the housing 11 and protruding upward as shown in FIG. 11 is inserted into the metallic support portion 30 projecting upward from the bottom surface, the end portion 31 of the delivery-side flow passage 13 is covered, and the support portion 30 is tightened with the screw 32, thereby supporting the support portion 30. It is fixed to.

As described above, the ends 23 and 28 of the bellows tube 2 are penetrated into the support bases 24 and 29 made of hard resin, respectively, when the bellows tube 2 is compressed. This is because the ends 23 and 28 of the tube 2 are supported by the support bases 24 and 29 so that they will not buckle.

The moving table 21 is slidably arranged in the housing 11 to the left and right, and a rod (connecting rod) 35 of the compression driving body 3 such as an air cylinder is connected to the moving table 21. Then, when air is supplied from one air port 36 of the compression driving body 3 and discharged from the other air port 37, the connecting rod 35 contracts and the movable table 21 is pulled to the right side to slide. As a result, the bellows tube 2 is compressed and contracted in the axial direction, and the inner volume of the bellows tube 2 is reduced. On the contrary, when air is supplied from the other air port 37 of the compression drive unit 3 and discharged from the other air port 36, the connecting rod 35 extends and the moving base 21 is pushed to the left. The bellows tube 2 is slid and slid, whereby the compression of the bellows tube 2 is released, the bellows tube 2 extends in the axial direction, and the inner volume thereof is increased.

Reference numeral 40 in FIGS. 1 to 3 is an adjusting screw for controlling the sliding of the moving base 21 to the left side. Therefore, screwing it into a screw hole formed on the side surface of the housing 11 and turning it to one side will enter the inside of the housing 11 (right side in FIG. 1), and rotating it in the opposite direction will cause it to go outside the housing 11 (see FIG. 1). It is designed to be pulled out to the left side, and moreover, it can be fixed at a desired position by tightening the tightening nut 41.

When the movable table 21 slides to the left side, the left side surface 45 of the movable table 21 abuts on the inner tip portion 46 of the adjusting screw 40 as shown in FIG. Is done. Therefore, by adjusting the degree of protrusion of the adjusting screw 40 to the inside of the housing 11, the maximum range of movement of the movable table 21 to the left side, that is, the maximum extension length of the bellows tube 2, that is, the content of the bellows tube 2. The amount of product increase, that is, the amount of suck back, can be adjusted. By adjusting the suck back amount, the liquid is sucked back near the ejection surface of the nozzle, and the liquid is instantaneously ejected from the nozzle at the next liquid ejection. A rubber piece 47 is attached to the inner front end portion 46 of the adjusting screw 40 so as to absorb the impact when the movable table 21 strikes.

To use the suck back device of the present invention, as shown in FIG. 6, the suck back device is arranged near the nozzle 50 in the flow path 1. Then, the liquid is pressure-fed from the pressure tank 51 to the flow path 1 and discharged from the nozzle 50 through the opening / closing valve 52 and the suck back device 53. At this time, the bellows tube 2 is compressed. Then, in order to stop the discharge of the liquid from the nozzle 50, the opening / closing valve 52 is closed to stop the supply of the liquid to the flow path 1. Almost at the same time, air is sent to the compression driving body of the suck back device 53 to release the compression of the bellows tube 2 to extend the bellows tube 2 and increase its internal volume. As a result, the liquid in the flow path 1 and the nozzle 50 is pulled back to prevent dripping.

[0019]

[Effect of device]

 The suck back device of the present invention has the following effects. (1) Since the bellows tube 2 is used, the suck back amount can be made large even with the short bellows tube 2, and therefore liquid dripping can be reliably prevented even in the case of a liquid having a large viscous resistance or a nozzle having a large discharge area. . Further, the size can be reduced. (2) In claim 2, since the bellows tube 2 is bent in a substantially U-shape to be expanded and contracted, the expansion and contraction length is about half that of the case where the bellows tube 2 is expanded and contracted in a linear state, and the same contents as in the linear state. Amount change can be obtained. In this case, the size can be further reduced. (3) By increasing the strength of the bellows tube 2 and the driving force for expansion and contraction, a large capacity suckback is possible.

[Brief description of drawings]

FIG. 1 is a plan view showing a state where a bellows tube of a suck back device of the present invention is compressed.

FIG. 2 is a plan view showing a state where a bellows tube of the suck back device is extended.

FIG. 3 is a vertical cross-sectional view showing a state in which a bellows tube of the suck back device is compressed.

FIG. 4 is a vertical cross-sectional view of the suck-back device with the bellows tube extended.

FIG. 5 is a vertical cross-sectional view of the vicinity of a connecting portion between a bellows tube and a flow path in the suck back device.

FIG. 6 is a schematic explanatory view of a liquid supply device to which the suck back device of the present invention is applied.

FIG. 7A is an explanatory diagram of a conventional suckback device during liquid supply, and FIG. 7B is an explanatory diagram of the suckback device of FIG.

FIG. 8A is an explanatory diagram of another conventional suckback device during liquid supply, and FIG. 8B is an explanatory diagram of the suckback device of FIG.

FIG. 9 is a schematic explanatory diagram of a conventional liquid supply device.

[Explanation of symbols]

 1 Flow path 2 Bellows tube 3 Compression driver

Claims (2)

[Scope of utility model registration request] 1. A suck back device for feeding a liquid under pressure through a flow path and discharging it from a nozzle, and pulling back the liquid when the discharge of the liquid is stopped to prevent the liquid from dripping from the nozzle. Provide a bellows tube 2
A suck back device for a liquid supply device, wherein the tube 2 is connected to a compression driving body 3 that compresses the tube 2 in the axial direction when the liquid is supplied and releases the compression when the liquid supply is stopped. 2. A suck back device for a liquid supply device, characterized in that the bellows tube (2) is curved in a substantially U shape and is provided in the flow passage (1).