JP2020078782A - Liquid resin manufacturing method and liquid resin manufacturing apparatus - Google Patents

Abstract

To reduce air bubbles included in liquid resin.SOLUTION: A liquid resin manufacturing apparatus 1 introduces liquid resin LR into a negative-pressure liquid feed tank 25 little by little, and then can degas the liquid resin LR to reduce or remove fine air bubbles mixed with the liquid resin LR like it is dissolved. Further, degassed liquid resin LR1 reserved in the liquid feed tank 25 can be fed by pressurizing the liquid feed tank 25. Consequently, the degassed liquid resin LR1 can be supplied to a supply destination with simple constitution.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a liquid resin manufacturing method and a liquid resin manufacturing.

  A wafer having a device formed in each of the areas of the surface divided by the dividing line has a wavelength that is absorptive to the wafer in order to divide the wafer along the dividing line to form individual chips. There is a method of irradiating a laser beam along a dividing line. However, in the division by the irradiation of the laser beam, debris generated by melting the wafer may be scattered and adhere to the device. The attachment of debris to the device causes the quality of the device to deteriorate. Therefore, a protective film is formed on the surface of the wafer by coating and solidifying the liquid resin, and the device is protected by this protective film (see, for example, Patent Document 1).

JP, 2004-322168, A

  Here, transportation of the liquid resin that is the material of the protective film is difficult. Therefore, a method of transporting the powdery water-soluble resin and dissolving the powdery water-soluble resin in a liquid to produce a liquid resin immediately before forming the protective film can be considered.

However, in this method, when the powdery water-soluble resin is dissolved in the liquid to produce the liquid resin, bubbles are likely to enter the liquid resin.
An object of the present invention is to reduce air bubbles contained in a liquid resin for forming a protective film that protects a device.

  The liquid resin production method of the present invention is a liquid resin production method of producing a liquid resin by mixing a powdered water-soluble resin and a liquid, and charging a liquid and a powdered water-soluble resin into a stirring container. , A liquid resin production step of producing a liquid resin by stirring with a stirring means, communicating the liquid resin in the stirring container with a suction source, and introducing the liquid resin into a liquid feeding tank having an internal pressure of negative pressure, A degassing step of degassing the liquid resin, an acquisition step of introducing air into the liquid sending tank, pressurizing the inside of the liquid sending tank to obtain the degassed liquid resin from the liquid sending tank, Is equipped with.

  The liquid resin production apparatus of the present invention is a liquid resin production apparatus for producing a liquid resin by mixing a powdered water-soluble resin and a liquid, and a stirring tank and a powdered water-soluble resin charged in the stirring tank. The liquid feeding means includes a stirring means for stirring the liquid to generate a liquid resin, a liquid feeding means for degassing the liquid resin and feeding the liquid resin to a supply destination, and a control means. A liquid feed tank, a pressure switching unit that selectively connects the liquid feed tank to either a suction source or an air supply source, an introduction path that connects the liquid feed tank to the stirring tank, and the introduction An introduction valve disposed in the passage, a discharge passage configured to discharge the liquid resin from the liquid supply tank, and a discharge valve disposed in the discharge passage, the control means including the introduction valve and the discharge valve. By closing the discharge valve and communicating the liquid sending tank with the suction source, a negative pressure is created in the liquid sending tank, and the introduction valve is opened to gradually introduce the liquid resin into the liquid sending tank to release the liquid resin. When a predetermined amount of the liquid resin is stored in the liquid sending tank, the introduction valve is closed, the liquid sending tank is connected to the air supply source, the inside of the liquid sending tank is pressurized, and the discharge is performed. The valve is opened and the liquid resin is sent to the supply destination.

  In the liquid resin manufacturing method and the liquid resin manufacturing apparatus of the present invention, by introducing the liquid resin into the negative pressure liquid feeding tank, the liquid resin is degassed, and fine bubbles mixed so as to melt into the liquid resin are reduced. can do. Further, the degassed liquid resin stored in the liquid sending tank can be obtained by pressurizing the liquid sending tank. Thus, the degassed liquid resin can be supplied to the supply destination with a simple configuration.

It is explanatory drawing which shows the structure of the liquid resin manufacturing apparatus concerning one Embodiment of this invention. It is explanatory drawing which shows the liquid resin manufacturing process by a liquid resin manufacturing apparatus. It is explanatory drawing which shows the deaeration process by a liquid resin manufacturing apparatus. It is explanatory drawing which shows the supply preparation process by a liquid resin manufacturing apparatus. It is explanatory drawing which shows the protective film formation process by a liquid resin manufacturing apparatus. It is explanatory drawing which shows the modification of the introduction path in a liquid resin manufacturing apparatus.

The liquid resin production apparatus 1 according to the present embodiment shown in FIG. 1 is an apparatus for producing a liquid resin by mixing a powdery water-soluble resin and a liquid.
The liquid resin manufacturing apparatus 1 includes a stirring tank 11 which is a stirring container, a stirring means 13 for generating a liquid resin in the stirring tank 11, a liquid feeding means 15 for degassing the liquid resin and feeding it to a supply destination, and a liquid state. A control means 17 for controlling each component of the resin manufacturing apparatus 1 is provided.

The water-soluble resin powder and pure water from the water source WS are supplied to the stirring tank 11. Pure water is an example of a liquid that is put into the stirring tank 11.
The stirring means 13 generates a liquid resin by stirring the powdered water-soluble resin and the pure water, which are put into the stirring tank 11.

  As shown in FIG. 1, the stirring means 13 includes a motor 51 disposed above the stirring tank 11, a rotating shaft 53 extending into the stirring tank 11, and an impeller 55 attached to the tip of the rotating shaft 53. There is. When the motor 51 rotates the rotating shaft 53, the impeller 55 rotates. The rotating impeller 55 stirs the water-soluble resin and the liquid in the stirring tank 11 to generate a liquid resin.

The liquid sending means 15 degasses the liquid resin generated by the stirring means 13 to reduce or remove air bubbles from the liquid resin, and sends the degassed liquid resin to the supply destination.
As shown in FIG. 1, the liquid feeding means 15 includes an introduction passage 19 extending from the inside of the stirring tank 11 to the outside, an introduction valve 21 and a squeezer 23 arranged in the introduction passage 19, and a downstream end of the introduction passage 19. Connected to the liquid feed tank 25, a discharge passage 27 provided under the liquid feed tank 25, a discharge valve 28 disposed in the discharge passage 27, and a pipe connecting the liquid feed tank 25 and the suction source 33. The pressure reducing valve 29 and the pressurizing valve 31 connected to the pipe connecting the liquid sending tank 25 and the air supply source 35 are provided.

  The introduction path 19 connects the liquid feeding tank 25 and the stirring tank 11 to each other, and is used to introduce the liquid resin from the stirring tank 11 into the liquid feeding tank 25. The introduction path 19 has one end arranged near the bottom of the stirring tank 11 and the other end connected to the introduction port 251 of the liquid feed tank 25.

  The introduction valve 21 can close or open the introduction passage 19. That is, the introduction valve 21 opens the introduction passage 19 when it is in the open state to allow the introduction of the liquid resin from the stirring tank 11 to the liquid feeding tank 25, and closes the introduction passage 19 when it is in the closed state. The introduction of the liquid resin from the stirring tank 11 to the liquid feeding tank 25 is shut off.

  The squeezer 23 is capable of squeezing (reducing) the amount of the liquid resin flowing on the downstream side of the introduction valve 21 in the introduction passage 19 when the introduction valve 21 is in the open state, and is introduced into the liquid sending tank 25. It is used to adjust the amount of liquid resin that is used.

  The liquid sending tank 25 is a pressure tank (pump) having pressure resistance capable of coping with depressurization and pressurization, and is designed to store liquid resin inside. The liquid resin is degassed inside the liquid feed tank 25.

The liquid feed tank 25 includes an inlet port 251 for the liquid resin from the stirring tank 11, a discharge port 253 for discharging the liquid resin stored inside the liquid feed tank 25, and an air pressure inside the liquid feed tank 25 ( The vent 255 is used to change the internal pressure.
A liquid level sensor 26 for detecting the amount of the liquid resin stored in the liquid feed tank 25 is provided on the side surface of the liquid feed tank 25.

  The discharge path 27 is a path for discharging the liquid resin from the liquid feed tank 25, and extends from the discharge port 253 of the liquid feed tank 25 to the spin coater 41 to which the liquid resin is supplied.

The spin coater 41 is an apparatus that forms a protective film made of a liquid resin on the wafer W. The spin coater 41 includes a holding table 43 that holds the wafer W, a supply nozzle 45 arranged on the holding table 43, a spindle 47 that is a rotation shaft of the holding table 43, and a motor 49 that rotates the spindle 47.
The supply nozzle 45 of the spin coater 41 is connected to the discharge passage 27 of the liquid resin manufacturing apparatus 1, and the liquid resin can be supplied to the wafer W on the holding table 43 from the end thereof.

The discharge valve 28 can open or close the discharge passage 27. That is, the discharge valve 28 opens the discharge passage 27 when it is in an open state to enable the liquid resin to be fed from the liquid feed tank 25, and closes the discharge passage 27 when it is in a closed state to feed the liquid resin. The liquid supply from the tank 25 is shut off.
The discharge valve 28 is also used to adjust the amount of liquid resin flowing from the liquid supply tank 25 to the discharge passage 27.

The decompression valve 29 is connected to the vent 255 and connects or disconnects the liquid supply tank 25 and the suction source 33. That is, the decompression valve 29 communicates between the liquid feed tank 25 and the suction source 33 when in the open state, and shuts off between the liquid feed tank 25 and the suction source 33 when in the closed state.
When the suction source 33 communicates with the liquid sending tank 25, the suction source 33 sucks the gas in the liquid sending tank 25 to reduce the internal pressure of the liquid sending tank 25.

The pressurizing valve 31 is similarly connected to the vent hole 255, and connects or shuts off the communication between the liquid sending tank 25 and the air supply source 35. That is, the pressurizing valve 31 connects the liquid sending tank 25 and the air supply source 35 when it is opened, and shuts off the liquid sending tank 25 and the air supply source 35 when it is closed.
When the air supply source 35 communicates with the liquid sending tank 25, the air is sent into the liquid sending tank 25 to pressurize the liquid sending tank 25 and increase the internal pressure of the liquid sending tank 25.

  The depressurizing valve 29 and the pressurizing valve 31 are configured such that when one is in the open state, the other is in the closed state. That is, the decompression valve 29 and the pressurization valve 31 correspond to an example of a pressure switching unit that selectively connects the liquid supply tank 25 to either the suction source 33 or the air supply source 35.

  The control unit 17 executes various kinds of processing to centrally control each component of the liquid resin manufacturing apparatus 1. For example, the control unit 17 controls the stirring unit 13 and the like to generate the liquid resin, and controls the liquid feeding unit 15 to perform degassing and liquid feeding of the liquid resin.

Here, the operation of the liquid resin manufacturing apparatus 1 having the above configuration will be described.
(1) Liquid Resin Manufacturing Step First, as shown in FIG. 2, the user puts the powdered water-soluble resin PR into the stirring tank 11. Then, the control means 17 controls the water source WS based on, for example, an instruction from the user, and inputs the pure water PW into the stirring tank 11. The amount of the powdery water-soluble resin PR charged into the stirring tank 11 is, for example, 100 kg.

  Next, the control means 17 controls the motor 51 of the stirring means 13 to rotate the rotary shaft 53 and the impeller 55 in the direction of arrow A, so that the powder water-soluble resin and the liquid charged in the stirring tank 11 are mixed. Is stirred to produce liquid resin LR. The production amount of the liquid resin LR is, for example, 500 liters, and the viscosity of the liquid resin LR is, for example, 200 cP. The pure water PW has a viscosity of about 1 cP. The liquid resin LR thus generated contains fine bubbles mixed so as to be melted by stirring.

  Further, in this step, as shown in FIG. 2, the control means 17 closes the introduction passage 19 by closing the introduction valve 21 and closes the introduction passage 19 to the liquid resin through the introduction passage 19 from the stirring tank 11 to the liquid feeding tank 25. Block the introduction of LR. Further, as shown in FIG. 2, the control unit 17 closes the discharge passage 27 by closing the discharge valve 28.

  Further, the control unit 17 closes the pressurizing valve 31 and opens the depressurizing valve 29. As a result, the liquid sending tank 25 is communicated with the suction source 33 via the vent 255 and the pressure reducing valve 29. On the other hand, since the introduction path 19 and the discharge path 27 are both closed, the introduction port 251 and the discharge port 253 of the liquid sending tank 25 are substantially closed. Therefore, the liquid sending tank 25 is connected to the outside via only the vent hole 255, and the internal pressure is lowered by suction by the suction source 33, so that the inside of the liquid sending tank 25 becomes a negative pressure. The control means 17 performs the following deaeration process, for example, when the internal pressure of the liquid feed tank 25 is lower than the installation atmosphere of the liquid resin manufacturing apparatus 1 by about 90 kPa.

(2) Deaeration Step In this step, the control means 17 opens the introduction passage 19 by opening the introduction valve 21 while maintaining the discharge valve 28 in the closed state, as shown in FIG. Remains blocked. Furthermore, the control means 17 also maintains the open state of the pressure reducing valve 29 and the closed state of the pressurizing valve 31. Therefore, the inside of the liquid sending tank 25 is kept at a negative pressure.

  As a result, the stirring tank 11 is communicated with the suction source 33 via the introduction path 19, the squeezer 23, the liquid feed tank 25, and the pressure reducing valve 29. Then, the introduction of the liquid resin LR from the stirring tank 11 into the negative pressure liquid feed tank 25 via the introduction path 19 is started. At this time, the control means 17 controls the wringer 23 so that the liquid resin LR is introduced into the liquid feed tank 25 little by little. For example, the control unit 17 controls the wringer 23 to adjust the amount of the liquid resin LR introduced into the liquid feed tank 25 to about 1 L/min.

  The liquid resin LR that has passed through the squeezing device 23 is introduced into the liquid sending tank 25 from the inlet 251 and propagates along the inner wall of the liquid sending tank 25 toward the bottom of the liquid sending tank 25 as indicated by arrow B. drop down. At this time, since the internal pressure of the liquid transfer tank 25 is negative, the liquid resin LR flowing down the inner wall of the liquid transfer tank 25 is degassed, and the liquid resin LR1 degassed at the bottom of the liquid transfer tank 25. Is stored.

(3) Acquisition process (supply preparation process and protective film formation process)
(3-1) Supply Preparation Step The control means 17 controls the liquid level sensor 26 to periodically or continuously grasp the amount of the degassed liquid resin LR1 accumulated in the liquid feed tank 25. For example, when the control unit 17 determines that the amount of the degassed liquid resin LR1 in the liquid feed tank 25 exceeds a predetermined amount, the control unit 17 performs the supply preparation step.

  In this step, as shown in FIG. 4, the control means 17 returns the introduction valve 21 to the closed state to close the introduction passage 19, while maintaining the discharge valve 28 in the closed state and closes the discharge passage 27. Leave it alone. Further, the control means 17 closes the pressure reducing valve 29 and opens the pressurizing valve 31. As a result, the liquid sending tank 25 is communicated with the air supply source 35 via the vent 255 and the pressurizing valve 31.

  On the other hand, since the introduction path 19 and the discharge path 27 are both closed, the introduction port 251 and the discharge port 253 of the liquid sending tank 25 are substantially closed. Therefore, since the liquid sending tank 25 is connected to the outside through only the vent hole 255, the internal pressure is raised by the pressurization by the air supply source 35. As a result, the inside of the liquid sending tank 25 has a positive pressure.

(3-2) Protective Film Forming Step In this step, as shown in FIG. 5, the control means 17 maintains the introduction valve 21 in the closed state and keeps the introduction passage 19 closed, while the discharge valve 28 is closed. The discharge path 27 is opened in the open state. Further, the control means 17 maintains the closed state of the pressure reducing valve 29 and the open state of the pressurizing valve 31.

  As a result, the degassed liquid resin LR1 is discharged and acquired from the inside of the liquid feed tank 25 pressurized by the air supply source 35 via the discharge port 253, the discharge valve 28, and the discharge passage 27. The degassed liquid resin LR1 discharged from the discharge passage 27 is sent toward the spin coater 41.

  Further, in this step, the holding table 43 holding the wafer W in the spin coater 41 is rotated by the motor 49 together with the spindle 47 in the direction of arrow C, for example. Then, the degassed liquid resin LR1 is supplied to the wafer W on the rotating holding table 43 via the supply nozzle 45, and the wafer W is covered with the degassed liquid resin LR1. Then, the protective film is formed on the wafer W by solidifying the degassed liquid resin LR1 on the wafer W.

As described above, in the liquid resin manufacturing apparatus 1, the liquid resin LR is degassed by gradually introducing the liquid resin LR into the negative pressure liquid feed tank 25, and mixed so as to dissolve in the liquid resin LR. Fine bubbles can be reduced or eliminated.
Further, the degassed liquid resin LR1 stored in the liquid sending tank 25 can be sent by pressurizing the liquid sending tank 25. Accordingly, the degassed liquid resin LR1 can be supplied to the supply destination with a simple configuration.
Further, before pressurizing the inside of the liquid sending tank 25, the introduction valve 21 is closed, the liquid sending tank 25 is kept in a sealed state for a predetermined time, and remains in the liquid resin LR1 stored in the liquid sending tank 25. Fine bubbles may be removed.

  In order to generate a liquid resin with few bubbles, it is possible to mix the powdery water-soluble resin and the liquid gently so that bubbles are not generated as much as possible. However, as compared with this method, degassing the liquid resin containing bubbles as in the present embodiment makes it possible to obtain the liquid resin with less bubbles in a shorter time.

  Further, in the present embodiment, the squeezing device 23 is arranged on the introduction path 19, whereby the amount of the liquid resin introduced into the liquid feed tank 25 is reduced. Instead, as shown in FIG. 6, the diameter of the portion 19b between the introduction valve 21 and the liquid feed tank 25 in the introduction passage 19 is made smaller than that of the portion 19a on the upstream side of the introduction valve 21. The amount of the liquid resin LR introduced into the liquid sending tank 25 may be reduced.

  Further, the liquid resin manufacturing apparatus 1 may include a plurality of liquid feed tanks 25. In this case, the control unit 17 may perform the above-described liquid resin manufacturing process, deaeration process, and acquisition process (supply preparation process and protective film formation process) for each liquid transfer tank 25 at different timings. By using the plurality of liquid transfer tanks 25, the degassed liquid resin LR1 can be continuously supplied to the spin coater 41.

  Further, it is preferable to use valves different from the check valve as the introduction valve 21 and the discharge valve 28. If a check valve is used as the introduction valve 21, the liquid resin LR in the stirring tank 11 may be sucked into the introduction valve 21 too much, which is not preferable in some cases. Similarly, if a check valve is used as the discharge valve 28, the degassed liquid resin LR1 in the liquid supply tank 25 may be discharged too much, which is not preferable.

Further, in the present embodiment, the degassed liquid resin LR1 discharged from the liquid sending tank 25 via the discharge passage 27 is supplied to the wafer W on the holding table 43. Alternatively, the degassed liquid resin LR1 discharged through the discharge passage 27 may be filled in a plurality of small tanks (not shown) having a capacity of 20 liters, for example. This makes it possible to manage the degassed liquid resin LR1 in small portions.
In this case, the spin coater 41 may be configured to receive the degassed liquid resin LR1 supplied from the small tank.

The liquid level sensor 26 may be a reflective sensor for determining whether or not the liquid level in the liquid sending tank 25 has reached a predetermined amount.
Further, in the present embodiment, the pressure reducing valve 29 and the pressurizing valve 31 are used as the pressure switching unit. Instead of these, a three-way valve may be used as the pressure switching unit.

1: Liquid resin manufacturing apparatus, 11: stirring tank, 17: control means,
13: stirring means, 51: motor, 53: rotating shaft, 55: impeller,
15: liquid feeding means, 19: introduction passage, 21: introduction valve, 23: squeezer,
25: Liquid sending tank, 26: Liquid level sensor, 27: Discharge passage,
28: discharge valve, 29: pressure reducing valve, 31: pressurizing valve,
33: suction source, 35: air supply source,
41: spin coater, 43: holding table, 45: supply nozzle,
47: Spindle, 49: Motor, W: Wafer,
PR: powdered water-soluble resin, LR: liquid resin, LR1: degassed liquid resin,
WS: Water source, PW: Pure water

Claims (2)

A liquid resin manufacturing method for manufacturing a liquid resin by mixing a powdered water-soluble resin and a liquid,
In a stirring container, a liquid and a powdered water-soluble resin are charged, and a liquid resin manufacturing step of manufacturing a liquid resin by stirring with a stirring means
A degassing step in which the liquid resin in the stirring container is communicated with a suction source, the liquid resin is introduced into a liquid feed tank having an internal pressure of negative pressure, and the liquid resin is degassed;
An introducing step of introducing air into the liquid sending tank, pressurizing the inside of the liquid sending tank to obtain the liquid resin degassed from the liquid sending tank;
A method for producing a liquid resin, comprising: A liquid resin production apparatus for producing a liquid resin by mixing a powdered water-soluble resin and a liquid,
A stirring tank,
A stirring means for stirring the powdery water-soluble resin and the liquid charged in the stirring tank to generate a liquid resin;
A liquid feeding means for degassing the liquid resin and feeding the liquid resin to a supply destination;
And a control means,
The liquid feeding means includes a liquid feeding tank, a pressure switching unit that selectively connects the liquid feeding tank to either a suction source or an air supply source, and an introduction that connects the liquid feeding tank to the stirring tank. A passage, an introduction valve arranged in the introduction passage, a discharge passage for discharging the liquid resin from the liquid feed tank, and a discharge valve arranged in the discharge passage,
The control means is
By closing the introduction valve and the discharge valve and connecting the liquid sending tank to the suction source, the inside of the liquid sending tank is made a negative pressure, and the introduction valve is opened to gradually feed the liquid resin into the liquid sending tank. Is introduced and degassed, and when a predetermined amount of the liquid resin is stored in the liquid sending tank, the introducing valve is closed, the liquid sending tank is communicated with the air supply source, and the inside of the liquid sending tank is heated. Press to open the discharge valve and send the liquid resin to the supply destination,
Liquid resin manufacturing equipment.

Images