JP3067864B2 - Module for semi-permeable membrane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semipermeable membrane module, and more particularly, to a pervaporation (hereinafter abbreviated as PV) method in a washing and drying apparatus using an organic solvent after washing a wafer or the like with water in a semiconductor manufacturing process. Alternatively, the present invention relates to a semipermeable membrane module used for removing water introduced into the organic solvent by a vapor permeation (hereinafter abbreviated as VP) method and reusing the organic solvent.

[0002]

2. Description of the Related Art In the course of a semiconductor manufacturing process, for example, in a process of processing a wafer, in a drying which is also performed by washing with water using isopropanol (hereinafter abbreviated as IPA) vapor after washing with water, this process is performed. Sometimes used IPA is 100% pure at the beginning of use
Is charged in an organic solvent evaporation tank (hereinafter abbreviated as evaporation tank). As the IPA once charged is used repeatedly, moisture adhering to the dried material to be washed and the like is brought into the IPA, and the IPA is removed. Gradually decreases in purity. Generally, when the purity of the IPA is 98% or less, a stain due to an impurity called a water mark occurs on a wafer surface or the like, and the probability of a defect as a semiconductor increases.

[0003] For this reason, the actual situation is that the IPA is usually replaced with a 100% pure IPA with a maximum purity of 98%.
A technique has been developed in which a solvent regenerating apparatus for removing water in IPA having reduced purity is provided to maintain the required purity of IPA. As a membrane module configuration mounted on the solvent regeneration device, a flat membrane lamination type, a spiral type, and a hollow fiber type are known. However, these membrane modules were installed outside the IPA dryer and the IPA dryer
PA is introduced into the membrane module by a pump or gravity to regenerate the IPA.

FIG. 5 shows a flow sheet when the solvent regenerating apparatus according to the conventional PV method is installed in the IPA drying apparatus. That is, the method shown in FIG. 5 includes a solvent supply pipe 1 and a cooler 5 for condensing the vapor of the solvent 2, and the object to be cleaned 6 such as a semiconductor wafer is cleaned by the vapor of the solvent 2 heated by the heater 4. A solvent regenerating device equipped with a PV membrane module 9 is attached to the outside of the evaporating tank 3 to be washed, and a solvent containing impurities is pumped from a liquid sending pump suction pipe 7 by a pump 8.
The solvent sent to the membrane module 9 and regenerated is returned to the evaporation tank 3 by a solvent return pipe 10. In addition, the membrane permeate is guided by a vacuum pump 15 having an exhaust pipe 16 through a vacuum pump suction pipe 11 to a condenser 12 having a cooling water pipe 13 through which cooling water flows, and is cooled and condensed to a drain pipe. Emitted from 14.

[0005] The apparatus shown in FIG. 5 is always provided with a pump 8 for feeding a solvent to the PV membrane module 9. The pump 8 is provided with a solvent for preventing a small amount of metal or metal ions from entering the solvent. The metal cannot be used in the portion that comes into contact with, and fine particles may be generated. Further, since there is a risk that the solvent is easily ignited by static electricity or the like, it is necessary to provide a safety measure. That is, the pump actually has various problems in selection or safety. In addition, when the solvent regenerating device is added to an existing evaporating tank, it is sometimes difficult to install the solvent regenerating device due to a small installation space, and there is a demand for downsizing of the solvent regenerating device.

The present inventors have found a method for regenerating the IPA without using the above-mentioned pump, and have already filed a patent application (Japanese Patent Application No. 2-297923). This method uses V
This is a method using a solvent regenerating apparatus in which a P membrane module is arranged in a vapor layer of an evaporation tank, and its flow sheet is shown in FIG. In other words, the method shown in FIG. 6 includes a cooler 5, in which a solvent 2 supplied from a solvent supply pipe 1 is heated by a heater 4, and the vapor cleans an object 6 such as a semiconductor wafer. A VP membrane module 9 ′ whose permeate side is depressurized by a vacuum pump 15 having an exhaust pipe 16 is disposed in the vapor layer of, and the membrane permeate is led out of the evaporation tank 3 by a vacuum pump suction pipe 11, and the cooling water In this method, the water is condensed in the condenser 12 cooled by the cooling water from the pipe 13 and discharged from the drain pipe 14.

However, the conventional PV or VP membrane module has been developed for the purpose of supplying a separation liquid or a separation gas mixture to the semipermeable membrane module, and the separation liquid or the separation gas mixture is provided without a supply pump. By merely installing the semipermeable membrane module in the above, the separation liquid or the separation gas mixture was not sufficiently supplied to the surface of the membrane, and high separation performance could not be obtained.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, in the present invention, when water adhering to the semiconductor wafer is replaced with vapor of isopropanol in the evaporation tank and dried, the water is used in the evaporation tank to remove a water component from the vapor or a liquid in which the vapor is condensed. A substantially semi-permeable membrane module having substantially no membrane shielding cover, comprising a main skeleton of the membrane module structure, wherein at least one surface is a perforated suction surface, and the perforated suction surface is internally provided. Through the porous spacer on the perforated suction surface of a flat rigid body having a membrane permeate circulation part that communicates with the vacuum suction nozzle for collecting the membrane permeate provided on the side surface while communicating with the hole of the, or The present invention provides a module for a semipermeable membrane, wherein a flat membrane semipermeable membrane is mounted in a liquid-tight manner without intervention.

The structure of the module for semipermeable membrane according to the present invention is such that a flat membrane semipermeable membrane is mounted on at least one side of a flat rigid body so as to be substantially uncovered and provided on a side face of the flat rigid body. It has a structure to collect the substance permeated through the semi-permeable membrane by sucking from the vacuum suction nozzle, so that the gas mixture or liquid mixture to be subjected to membrane separation can be supplied to the membrane surface without using a supply pump. Things. In addition,
When the film area is insufficient with one module, the module can be used in multiple layers at intervals.

[0010] The perforated suction surface of the flat rigid body as referred to in the present invention means any shape and shape as long as it has a hole capable of suction.
It may be in the form of, for example, a plate having a surface of a perforated plate in which a number of holes are drilled, a surface formed of a mesh-like material, or a surface formed of a sintered porous material substantially all or partially. . In addition, the flat rigid body does not need to be a completely flat surface, and may be curved or corrugated. Further, inside the flat rigid body, there is a membrane permeate flow section which communicates with the hole of the perforated suction surface and also communicates with the vacuum suction nozzle provided on the side surface for collecting the membrane permeate. The portion may be, for example, a substantially hollow when the perforated suction surface is formed of a perforated plate, or may be a passage connecting to the perforated suction surface if the perforated suction surface is formed of a surface having a large number of sintered porous bodies. .

The attachment of the flat membrane semipermeable membrane to the perforated suction surface of the flat rigid body according to the present invention can be performed, for example, by using an ultrasonic wave or the like with or without a porous spacer such as a plastic net structure material. Heat welding, crimping with a rigid holding frame, or both methods, or using a rigid holding frame as a flange type, for example, using a bolt and a nut or a vise through a sealing material such as packing or liquid sealant , Clamping and liquid-tight. The rigid holding frame used in the present invention may have any shape and form as long as it has an opening degree that does not substantially hinder the supply of the object to be separated to the membrane surface. And a flat plate on which a large window is formed.

Hereinafter, embodiments of the membrane module of the present invention will be described with reference to the drawings. FIG. 1 shows a plan view of an example of a semipermeable membrane module according to the present invention. FIG. 2 is a cross-sectional view taken along the line AA of the center of FIG. 1 and has a vertically symmetric structure.
The plate-shaped rigid body 31 has a porous surface in which a large number of holes 38 are drilled, and a porous plate portion 31 on the upper surface provided with a convex portion 39 for preventing bending due to vacuum by being brought into contact with each other on the back side. -1 and a perforated plate portion 31-2 on the lower surface, the periphery of which is welded by ultrasonic waves, a vacuum suction nozzle 37 is provided on the side surface, and the inside is substantially hollow. Here, in FIGS. 1 and 2, reference numerals -1 and -2 indicate the same members on the upper surface and the lower surface in the case of a structure in which a semipermeable membrane is mounted on both sides, and thus will not be described below.
The flat membrane semi-permeable membrane 34 is sandwiched between the back packing 32 and the front packing 35 via a spacer 33 having a plastic mesh structure on the perforated plate surface of the flat rigid body 31, and is pressed by a holding frame 36, Assembled. The two packings may be ultrasonically welded. 1 and 2, a flat rigid body
Although an example is shown in which the periphery of the holding frame 31 and the holding frame 36 are welded by ultrasonic waves, the holding frame 36 may be a flange type and may be tightened with bolts and nuts or may be tightened with a vice or the like. By connecting a vacuum suction nozzle 37 attached to the side surface of the module to a vacuum system, the pressure on the permeation side of the semipermeable membrane is reduced. When the semi-permeable membrane 34 is fixed with the holding frame 36, the holding frame 36 and the semi-permeable membrane 34
It is also possible to laminate a film on the contact portion of the above.

FIG. 3 is a plan view showing another embodiment of the present invention, and FIG. 4 is a sectional view taken along the line BB of the central part of FIG. In the plate-shaped rigid body 51, a sintered porous plate 52 of a net-like or micro-sphere is embedded in a large number of recesses provided on the surface thereof, and a sampling port for a membrane permeate opened in the center of the recess. Each communicates with a passage formed therein and also communicates with a vacuum suction nozzle 58. Semipermeable membrane 55
The back packing 54 and the front packing 56 are provided on the surface of the flat rigid body 51 with a spacer 53 having a plastic mesh structure on the surface.
And press-fitted by a holding frame 57 for mounting. 3 and 4, a flat rigid body 51 and a holding frame are shown.
An example of welding by ultrasonic waves around 57 is shown,
57 may be a flange type and may be tightened with bolts and nuts or with a vice or the like.

[0014]

The membrane module according to the present invention has little or no elution of the adhesive component from the module surface, so that the solvent is less contaminated. In the IPA drying of a water-washed wafer in the semiconductor industry, Little accumulation of eluate in the IPA of substances contaminating wafers and the like. Furthermore, although the inside of the evaporating tank of the IPA drying apparatus has little extra space, the membrane module according to the present invention can be made as thin as 4 cm or less, which saves space. Easy.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a semipermeable membrane module according to the present invention.

FIG. 2 is a cross-sectional view taken along line AA of a central portion of FIG.

FIG. 3 is a plan view showing another example of the semipermeable membrane module according to the present invention.

FIG. 4 is a sectional view taken along the line BB of the central part of FIG.

FIG. 5 is a flow sheet showing a conventional solvent regenerating method in which a solvent regenerating device is mounted outside an evaporating tank.

FIG. 6 is a flow sheet showing a solvent regeneration method in which a VP membrane module is arranged in a vapor layer of an evaporation tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solvent supply pipe 2 Solvent 3 Evaporation tank 4 Heater 5 Cooler 6 To-be-cleaned object 7 Liquid supply pump suction pipe 8 Liquid supply pump 9 PV membrane module 9 'VP membrane module 10 Solvent return pipe 11 Vacuum pump suction pipe 12 Condenser 13 Cooling water Pipe 14 Drain pipe 15 Vacuum pipe 16 Exhaust pipe 31-1 Upper perforated plate section 31-2 Lower perforated plate section 32-1 Upper back packing 32-2 Lower back packing 33-1 Top plastic net Structure spacer 33-2 Lower surface plastic mesh spacer 34-1 Upper semi-permeable membrane 34-2 Lower semi-permeable membrane 35-1 Upper surface packing 35-2 Lower surface packing 36-1 Upper surface Pressing frame 36-2 Lower holding frame 37 Vacuum suction nozzle 38 Hole in perforated plate 39 Convex portion 51 Flat rigid body 52 Mesh or sintered perforated plate 53 Plastic mesh spacer 54 Back packing 55 Semi-permeable membrane 56 Front packing 57 Presser frame 58 Vacuum suction nozzle

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kyoji Maeda 500 Kamiyobe, Yobe-ku, Himeji-shi, Hyogo (72) Inventor Masashi 5-2-1, Kamimizuhoncho, Kodaira-shi, Tokyo Musashi Plant, Hitachi, Ltd. (72) Inventor Seiichi Ishii 5-2-1, Josuihoncho, Kodaira-shi, Tokyo Inside Musashi Factory, Hitachi, Ltd. (72) Yoshiro Niimura 5-2-1, Josuihoncho, Kodaira-shi, Tokyo Shares (72) Inventor Katsuhiro Mitsuda 5-2-1, Josuihonmachi, Kodaira-shi, Tokyo Inside Hitachi, Ltd. Musashi Factory (72) Inventor Hideki Shirai 29-16, Tsuruta-cho, Utsunomiya, Tochigi 56) References JP-A-62-161736 (JP, A) JP-A-61-239628 (JP, A) JP-A-63-35422 (JP, U) JP-A-55-141504 (JP, U) (58) ) Surveyed Field (Int.Cl. ⁷ , DB name) B01D 63/08 B01D 53/22 B01D 69/10 H01L 21/304 645 H01L 21/304 648

Claims (1)

(57) [Claims] 1. A upon the water attached to the semiconductor wafer in the evaporation vessel to replace dried isopropanol vapor, used in the evaporation vessel to the steam or vapor to remove the water component from the condensed liquid A plate-like semipermeable membrane module having substantially no membrane shielding cover, which constitutes a main skeleton of the membrane module structure, wherein at least one surface is a perforated suction surface, and the inside thereof has the perforated suction surface. Through a porous spacer, a porous spacer is provided on the perforated suction surface of a flat rigid body having a flow portion for the membrane permeate which communicates with the hole and also communicates with the vacuum suction nozzle provided on the side surface for collecting the membrane permeate. A module for a semipermeable membrane, wherein a flat membrane semipermeable membrane is mounted in a liquid-tight manner without using a flat membrane.