Bubbler tube and bubbler

Abstract

To provide a tube for a bubbler capable of achieving the bubbler that is excellent in chemical resistance and heat resistance, has high kink resistance, and can suppress a pressure loss of gas.SOLUTION: A bubbler tube is provided. The bubbler tube includes: a first tube having a first inner peripheral surface and a first outer peripheral surface; and a second tube having a second inner peripheral surface and a second outer peripheral surface. The first tube contains polytetrafluoroethylene and has a porous region. The second tube includes a plurality of convex portions that are independent from each other and protrude in a radial direction of the second tube, and an independent mountain region having a plurality of concave portions provided between the plurality of convex portions. The independent mountain region is provided with at least one through hole penetrating from the second inner peripheral surface to the second outer peripheral surface. The first tube covers at least part of the independent mountain region so as to cover the at least one through hole.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , ,

[0005] , ,

[0001] The present invention relates to a tube for a bubbler and a bubbler.

Background Art

[0002] In semiconductor manufacturing processes and the like, a gas injection device, a so-called bubbler, is used to prevent the retention of chemical solutions and eliminate temperature unevenness. Bubblers used for these purposes are required to have excellent chemical resistance and heat resistance. Therefore, fluororesin-made bubblers with excellent chemical resistance and heat resistance are on the market.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

[0007] To suppress pressure loss, a two-layer bubbler structure has been considered, in which a non-porous tube is placed inside a porous tube. However, because two-layer bubblers have a high restoring force against bending, it is difficult to install them while maintaining their bent shape. In other words, this presents a problem of reduced flexibility in installation.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a bubbler tube that is excellent in chemical resistance and heat resistance, has high kink resistance, and can realize a bubbler that can suppress gas pressure loss, and a bubbler equipped with said bubbler tube. [Means for solving the problem]

[0009] According to a first embodiment of the present invention, a bubbler tube is provided. The bubbler tube comprises a first tube having a first inner circumferential surface and a first outer circumferential surface, and a second tube having a second inner circumferential surface and a second outer circumferential surface. The first tube contains polytetrafluoroethylene and has a porous region occupying from the first inner circumferential surface to the first outer circumferential surface. The second tube has independent peak regions having a plurality of convex portions that are independent of each other and protrude radially from the second tube, and a plurality of recesses provided between the plurality of convex portions. The plurality of convex portions and the plurality of recesses are arranged alternately along the axial direction from one end to the other of the second tube. The independent peak regions are provided with at least one through hole penetrating from the second inner circumferential surface to the second outer circumferential surface. The first tube covers at least a portion of the independent peak regions so as to cover at least one through hole.

[0010] A second embodiment of the present invention provides a bubbler tube. The bubbler tube comprises a first tube having a first inner circumferential surface and a first outer circumferential surface, and a second tube having a second inner circumferential surface and a second outer circumferential surface. The first tube contains polytetrafluoroethylene and has a porous region occupying from the first inner circumferential surface to the first outer circumferential surface. The second tube has a helical uneven region. The helical uneven region has helical protrusions and helical recesses that extend spirally along the axial direction from one end to the other of the second tube. The helical uneven region is provided with at least one through hole penetrating from the second inner circumferential surface to the second outer circumferential surface. The first tube covers at least a portion of the helical uneven region so as to cover at least one through hole. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a bubbler tube that is excellent in chemical resistance and heat resistance, has high kink resistance, and can suppress gas pressure loss, and a bubbler equipped with the bubbler tube. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic cross-sectional view showing an example of a bubbler tube according to the first embodiment. [Figure 2] A schematic cross-sectional view showing an example of a second tube included in a bubbler tube according to the first embodiment. [Figure 3] A schematic cross-sectional view showing an example of a bubbler tube according to the second embodiment. [Figure 4] A schematic cross-sectional view showing an example of a second tube included in a bubbler tube according to the second embodiment. [Figure 5] A schematic cross-sectional view showing an example of a bubbler tube according to the third embodiment. [Figure 6] A schematic diagram illustrating an example of a bubbler according to the fourth embodiment. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments will be described with reference to the drawings as appropriate. In the embodiments, the same reference numerals are assigned to common configurations, and redundant descriptions are omitted. In addition, each figure is a schematic diagram for facilitating the explanation and understanding of the embodiments. Although there are parts where the shape, dimensions, ratio, etc. are different from the actual device, these can be appropriately modified in design in consideration of the following description and known techniques.

[0014] (First Embodiment) The bubbler tube according to the first embodiment includes a first tube and a second tube.

[0015] The first tube contains polytetrafluoroethylene. Therefore, the first tube is excellent in heat resistance and chemical resistance.

[0016] The first tube has a first inner peripheral surface and a first outer peripheral surface, and includes a porous region that occupies from the first inner peripheral surface to the first outer peripheral surface.

[0017] The structure of the porous region of the first tube 11 is a structure resulting from the properties of the PTFE contained in the first tube 11. That is, the structure of the porous region of the first tube 11 is a fine structure composed of nodes and fibrils made of PTFE. When a solid structure tube containing PTFE is uniaxially stretched, fibrils are approximately drawn out from the nodes along the stretching direction. A node refers to a region where the PTFE material aggregates without the polymer fiber being stretched. A fibril refers to a polymer fiber that exists between nodes and is oriented along the stretching direction. A large number of through holes (communication holes) are formed between nodes, between fibrils, and between nodes and fibrils. Therefore, the first tube can supply, for example, the gas supplied to the first inner peripheral surface side of the first tube to the first outer peripheral surface side through the porous region.

[0018] The second tube has a second inner circumferential surface and a second outer circumferential surface. The second tube has an independent mountain region that is independent from each other and has a plurality of convex portions protruding in the radial direction of the second tube, and a plurality of concave portions provided between the plurality of convex portions. The plurality of convex portions and the plurality of concave portions are alternately arranged along the axial direction from one end to the other end of the second tube.

[0019] The independent mountain region is, for example, a region where the tube wall surface is shaped into a waveform. By folding the convex and concave portions of the independent mountain region, the second tube can be contracted along the axial direction. Also, by stretching the convex and concave portions so as to flatten the unevenness, the second tube can also be extended along the axial direction. Therefore, when the second tube is bent, the portion located on the inner diameter side of the bend in the independent mountain region can be contracted, and the portion located on the outer diameter side of the bend can be extended. Therefore, the second tube provided with the independent mountain region can flexibly follow bending and is less likely to break or collapse. That is, it has high kink resistance.

[0020] At least one through hole penetrating from the second inner circumferential surface to the second outer circumferential surface is provided in the independent mountain region of the second tube. Therefore, the gas supplied to the second inner circumferential surface side of the second tube passes through the through hole from the second inner circumferential surface side toward the second outer circumferential surface side.

[0021] The first tube covers at least one through hole provided in the wall surface of the second tube. That is, the first inner circumferential surface of the first tube is located more outside than the second outer circumferential surface of the second tube. Therefore, the gas that has passed through the wall surface of the second tube through the through hole as described above stays between the first inner circumferential surface of the first tube and the second outer circumferential surface of the second tube. Alternatively, the gas can be supplied to the first outer circumferential surface side through the porous region of the first tube without staying.

[0022] In the bubbler tube according to this embodiment, since the second tube is positioned inside the first tube, even if the first tube becomes long, an increase in gas pressure loss can be suppressed. Specifically, for example, gas flowing into the second tube from one end of the second tube mainly passes through the inside of the second tube to reach the other end of the second tube. Although the second tube has at least one through hole, the second inner circumferential surface is made of, for example, a non-porous structure. Therefore, pressure loss can be reduced compared to the case where gas flows directly through the first tube which has a porous region. Thus, a bubbler tube with the second tube inside can release gas relatively uniformly from the entire first outer circumferential surface of the first tube, thereby reducing pressure loss.

[0023] Furthermore, as described above, the first tube is located on the outside of the second tube. Therefore, for example, when the bubbler tube according to the embodiment is bent, even if a force is applied in a direction that causes the bubbler tube to collapse radially, the shape of the first tube can be supported by the inner second tube. In other words, the bubbler tube has a second tube on the inside that is less prone to kinking, and therefore exhibits high kink resistance. The bubbler tube according to the embodiment is also superior in terms of installation flexibility because kinking is easily suppressed.

[0024] The first embodiment will be further described below with reference to Figures 1 and 2. Figure 1 is a cross-sectional view along the axial direction of the bubbler tube according to the first embodiment. Figure 2 is a cross-sectional view along the axial direction of the first tube included in the bubbler tube according to the first embodiment.

[0025] In Figures 1 to 5, the X-axis is aligned with the axial direction (longitudinal direction) of the bubbler tube. The Y-axis is perpendicular to the X-axis. The Z-axis is perpendicular to both the X and Y axes. The radial direction is aligned with the YZ plane, which includes the Y and Z axes.

[0026] The bubbler tube 10 comprises a first tube 11 and a second tube 12. In Figure 1, the symbol C indicates the central axis of the bubbler tube 10.

[0027] The first tube 11 is a tube extending from one end 110 to the other end 111. The first tube 11 has a first inner circumferential surface 11a and a first outer circumferential surface 11b. The first tube 11 is, for example, a cylindrical tube having a predetermined inner diameter and outer diameter.

[0028] The first tube 11 contains polytetrafluoroethylene (PTFE), which has high chemical and heat resistance. Therefore, it can be used, for example, as a gas supply section (bubbling section) when using chemicals such as resists, developers, organic solvents, strong acids, and strong alkalis used in semiconductor manufacturing.

[0029] The porous region of the first tube 11 has a microstructure consisting of the nodes and fibrils described above. Therefore, the porous region has the function of allowing only particles smaller than the communication pores contained in this microstructure to pass through, while preventing the passage of particles larger than the communication pores. Accordingly, for example, by immersing the portion of the first tube 11 where the porous region exists in the chemical solution and injecting gas into the first inner circumferential surface 11a side, the gas can be supplied into the chemical solution through the porous region, and the chemical solution can be prevented from entering the first inner circumferential surface 11a side.

[0030] The porosity of the porous region is preferably between 5% and 80%. Preferably, the porosity is within the range of 10% to 40%. A porosity of 10% or more allows for high efficiency in supplying gas to the chemical solution. A porosity of 40% or less allows for high strength of the first tube 11.

[0031] Furthermore, the porous region contained in the first tube 11 may occupy, for example, 50% or more by volume, 80% or more by volume, or 100% by volume of the first tube 11.

[0032] The second tube 12 is a tube that extends from one end 120 to the other end 121. The second tube 12 has a second inner circumferential surface 12a and a second outer circumferential surface 12b. The second tube 12 is, for example, a cylindrical tube having a predetermined inner diameter and outer diameter.

[0033] In the second tube 12, it is preferable that the portion other than the through-hole 122 has a non-porous structure (solid structure). In this specification and claims, a non-porous structure refers to a portion having a porosity of less than 5%. The lower limit of the porosity is not particularly limited and may be 0%.

[0034] If the portion of the tube other than the through-hole 122 has a non-porous structure, gas leakage from the portion of the second tube 12 wall other than the through-hole 122 can be prevented. Therefore, a bubbler tube with low pressure loss can be provided.

[0035] Furthermore, as shown in Figure 2, the second tube 12 comprises an independent mountain region 123 having a plurality of radially protruding protrusions 123a and a plurality of recesses 123b provided between the plurality of protrusions. Each of the plurality of protrusions 123a is provided, for example, around the entire circumference of the wall surface of the cylindrical second tube 12.

[0036] The ratio of the inner diameter of the second tube at the deepest part of the multiple recesses 123b to the inner diameter of the second tube at the apex of the multiple protrusions 123a is not particularly limited, but is, for example, within the range of 50% to 80%.

[0037] The independent peak region 123 can maintain its shape when bent. Therefore, the bubbler tube 10 equipped with the second tube 12 does not require a jig to fix the shape of the tube during installation. For this reason, the bubbler tube is suitable for applications where it is necessary to maintain the three-dimensional structure formed by bending the bubbler tube, and for applications where it is difficult to place fixing jigs.

[0038] The ratio of the length of the isolated mountain region 123 to the total length of the second tube 12 is, for example, within the range of 50% to 100%.

[0039] In the independent peak region 123, the spacing (arrangement interval) 123c between the protrusions 123a is preferably 1.0 mm or more and 20.0 mm or less. A smaller arrangement interval 123c allows for higher conformability of the independent peak region to bending.

[0040] The 123c spacing can be measured as follows:

[0041] First, the independent peak region 123 is stretched along the axial direction. After standing for 1 minute, the distance along the axial direction from the vertex of one protrusion to the vertex of the adjacent protrusion is measured as the distance between the protrusions. Here, the vertex of a protrusion refers to the point on that protrusion that is furthest from the central axis C in the cross section along the axial direction of the second tube 12.

[0042] If the second tube 12 has more than six protrusions, five arbitrary combinations of adjacent protrusions are selected, and the distance between the protrusions in each combination is measured. If the second tube 12 has six or fewer protrusions, the distance between all adjacent protrusions is measured. The measured distances between the protrusions are averaged to obtain the array spacing 123c. The distance between the protrusions can be measured using calipers, a microscope, or a projector.

[0043] The following provides further explanations for each component.

[0044] (First tube) The inner diameter of the first tube 11 is not particularly limited, but is, for example, within the range of 0.5 mm to 30 mm. The outer diameter of the first tube 11 is not particularly limited, but is, for example, within the range of 0.7 mm to 40 mm. The wall thickness of the first tube 11 is, for example, within the range of 0.1 mm to 5.0 mm. The wall thickness of the first tube 11 is defined by the radial distance from the first inner circumferential surface 11a to the nearest first outer circumferential surface 11b.

[0045] The inner diameter of the tube can be measured using a pin gauge or caliper with an accuracy of 1 / 1000 mm. The outer diameter of the tube can be measured using a caliper, microscope, or projector.

[0046] By not making the walls of the first tube 11 excessively thick, the possibility of the first tube 11 losing flexibility can be avoided. Also, by not making the walls of the first tube 11 excessively thin, the possibility of the first tube 11 losing strength can be avoided.

[0047] The length of the first tube 11 is not particularly limited, but is, for example, within the range of 0.1m to 5.0m.

[0048] One end 110 of the first tube 11 may be one end 100 of the bubbler tube 10.

[0049] (Second tube) The second tube 12 is positioned inside the first tube 11. Therefore, the outer diameter of the second tube 12 is smaller than, for example, the inner diameter of the first tube 11.

[0050] The wall thickness of the second tube 12 is, for example, within the range of 0.1 mm to 5.0 mm. The wall thickness of the second tube 12 is defined by the radial distance from the inner circumferential surface 12a of the second tube 12 to the nearest outer circumferential surface 12b. If the wall thickness of the second tube 12 is excessively thick, the flexibility of the tube may be poor. In order for the second tube 12 to have excellent flexibility, it is preferable that the wall thickness of the second tube 12 is within the range of 0.5 mm to 1.5 mm.

[0051] The second tube 12 preferably has two or more through holes 122. The through holes 122 are holes that penetrate the wall surface of the second tube 12. That is, the through holes 122 penetrate from the inner circumferential surface 12a to the outer circumferential surface 12b. It is more preferable that the two or more through holes 122 are arranged along the axial direction of the second tube 12, so that gas can be supplied uniformly from the second outer circumferential surface 12b. The two or more through holes 122 do not have to be arranged along one direction. The shape of the holes is not particularly limited, but for example, they may be circular or substantially circular.

[0052] The diameter of the through-hole 122a is not particularly limited, but for example, the diameter of the hole is in the range of 0.1 mm to 5.0 mm. Preferably, the diameter of the through-hole 122a is in the range of 1.0 mm to 3.0 mm. If the diameter of the through-hole is 0.1 mm or more, the workability when forming the through-hole can be improved. If the diameter of the through-hole is 5.0 mm or less, the pressure loss when gas flows through the second tube 12 can be reduced.

[0053] The average diameter of the through-holes 122 can be measured as follows: If the second tube 12 has more than five through-holes 122, five through-holes are selected and the diameter of each through-hole (through-hole diameter 122a) is measured. If the second tube 12 has five or fewer through-holes, the diameter of each through-hole is measured. The average of the measured through-hole diameters is taken as the average diameter of the through-holes 122. The through-hole diameter can be measured using a pin gauge or caliper with an accuracy of 1 / 1000 mm.

[0054] When there are two or more through holes 122, the spacing between them (distance between the centers of the holes) is not particularly limited, but is, for example, within the range of 10 mm to 500 mm. The two or more through holes 122 may be arranged at a fixed interval, or they may be arranged with any spacing between them. For example, the spacing between two through holes 122 located at a certain position and adjacent to each other may be different from the spacing between two through holes 122 located at different positions and adjacent to each other.

[0055] The resin constituting the second tube 12 is not limited to fluororesins, but various thermoplastic resins and thermosetting resins can be used. From the viewpoint of chemical resistance and heat resistance, it is preferable that the second tube 12 contains a fluororesin. Examples of fluororesins included in the second tube 12 include at least one selected from the group consisting of polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene, perfluoroalkoxyalkane (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroethylenepropene copolymer (FEP), and polyvinylidene fluoride (PVDF).

[0056] (Method for manufacturing a bubbler tube according to the first embodiment) An example of a method for manufacturing a bubbler tube according to the first embodiment is described below. The first tube can be manufactured, for example, by uniaxially stretching a PTFE tube having a non-porous structure (solid structure). The PTFE tube having a solid structure that serves as a precursor to the first tube may be, for example, an extruded product. An example of extrusion molding is described below.

[0057] As raw materials for extruded products, PTFE fine powder and extrusion aids such as lubricants can be used. By mixing PTFE fine powder with extrusion aids such as lubricants, a paste-like mixture can be obtained. By extruding the mixture containing PTFE fine powder into a tube shape, a tubular extruded product can be obtained.

[0058] Examples of extrusion aids include commonly used solvent naphtha (e.g., registered trademark: Isoper E, manufactured by Exxon Chemicals), white oil, and liquid paraffin with 6 to 12 carbon atoms (e.g., registered trademark: Cactus Normal Paraffin N-10, manufactured by Japan Energy Co., Ltd.).

[0059] The mixture obtained by mixing PTFE fine powder and an extrusion aid may be aged before being subjected to extrusion molding. Alternatively, the aged mixture may be compressed to produce a compressed molded body (billet). Compression removes air from the PTFE fine powder, improving the uniformity of the extruded product. The shape of the compressed molded body is not particularly limited, but it may be cylindrical, for example.

[0060] Next, the PTFE tube manufactured as the first tube precursor is uniaxially stretched. During uniaxial stretching, polymer fibers are drawn out from the polymer material contained in the first tube precursor and stretched in the direction of stretching. In this way, a microstructure containing nodes and fibrils can be formed.

[0061] The specific gravity or porosity of the first tube can be adjusted by adjusting the stretching ratio during uniaxial stretching. Increasing the stretching ratio during uniaxial stretching allows for the formation of a first tube with high porosity and low specific gravity. Lowering the stretching ratio during uniaxial stretching allows for the formation of a first tube with low porosity and high specific gravity. For example, setting the stretching ratio during uniaxial stretching to 2 times produces a first tube with approximately 50% porosity. The stretching ratio can be adjusted as appropriate according to the desired specific gravity, but is generally within a range of 1.2 times to 6 times.

[0062] Next, the first tube, which is in an unfired state, is subjected to drying and firing. Drying is carried out, for example, in a drying oven. By drying at a temperature above the boiling point of the petroleum-based extrusion aid used earlier, the aid can be volatilized. Subsequently, the dried tube is fired by heating it at a temperature above the melting point of PTFE, for example, 330°C or higher. Firing can be carried out, for example, by fixing the extruded product, to prevent the tube from shrinking. In this way, the first tube can be manufactured.

[0063] The second tube can be manufactured, for example, by forming independent peak regions and providing through holes in a fluororesin tube having a solid structure.

[0064] Specifically, it is made as follows:

[0065] First, a tube with an inner and outer diameter that is approximately constant along its entire length is manufactured by a known molding method such as extrusion molding or injection molding. Then, independent peak regions are formed by the following method.

[0066] Independent peak regions can be formed, for example, by blow molding. First, a tube with an inner and outer diameter that is approximately constant along its entire length is heated to a temperature above the softening point of the fluororesin that makes up the tube to soften it. The tube is then pressurized (blown) from the inner diameter side within a mold. The mold consists of, for example, an upper mold and a lower mold. When the upper and lower molds are combined, the shape inside the mold is cylindrical with an inner circumferential surface. The inner circumferential surface of the mold has a shape that corresponds to the outer circumferential surface shape of the desired independent peak region. The tube, which has been expanded by pressurization, adheres closely to the inner circumferential surface of the mold, thereby forming the desired independent peak region. The expanded tube is then cooled to harden the fluororesin and fix the shape of the independent peak region.

[0067] When forming independent peak regions, a bending process may be performed after blow molding. The bending is performed by compressing the irregularities of the independent peak regions formed by the blow molding described above along the axial direction of the tube, for example, at a temperature below the softening point. The temperature below the softening point may be, for example, around 30°C. After the bending process, the tube may be further heated, for example, at a temperature between 80°C and 200°C. Independent peak regions that have undergone the further bending process tend to have excellent elasticity and excellent shape retention when the tube is bent.

[0068] The through holes can be formed by drilling or the like. When multiple through holes are provided in the second tube, the multiple through holes may or may not be arranged in one direction.

[0069] The inner and outer diameters of the first tube, and the inner and outer diameters of the second tube, can be designed and manufactured to desired values, however, the inner diameter of the first tube is made larger than the outer diameter of the second tube.

[0070] Next, the fabricated second tube is inserted into the first inner circumferential surface of the first tube. At this time, the first tube is made to cover at least one through hole. In this way, a bubbler tube according to the first embodiment can be fabricated.

[0071] (Second embodiment) The bubbler tube according to the second embodiment comprises a first tube and a second tube. As described below, the bubbler tube according to the second embodiment has the same structure as the bubbler tube according to the first embodiment, except that the structure of the second tube is different.

[0072] The first tube in the second embodiment is the same tube as described in the first embodiment.

[0073] The second tube according to the second embodiment will be described with reference to Figures 3 and 4. Figure 3 is a schematic cross-sectional view showing an example of a bubbler tube according to the second embodiment. Figure 4 is a schematic cross-sectional view showing an example of a second tube included in the bubbler tube according to the second embodiment.

[0074] The second tube 12 according to the second embodiment includes a helical uneven region 124 instead of an independent peak region 123. The second tube 12 according to the second embodiment has the same configuration as described in the first embodiment, except for the difference in these regions.

[0075] The spiral uneven region 124 has spiral projections 124a and spiral recesses 124b that extend spirally along the axial direction from one end 120 to the other end 121 of the second tube. The second tube 12 shown in Figure 4, as an example, has a spiral uneven region 124 comprising one continuous spiral projection 124a and one continuous spiral recess 124b. The spiral uneven region 124 is provided, for example, around the entire circumference of the wall surface of a cylindrical second tube 12.

[0076] The cross-section of the spiral uneven region 124 along the axial direction has an uneven structure in which radially protruding portions, which are part of the spiral protrusions 124a, and radially recessed portions, which are part of the spiral recesses 124b, are arranged alternately along the axial direction.

[0077] Therefore, when the second tube 12 is bent, the spiral uneven structure in the portion of the spiral uneven region 124 located on the inner diameter side of the bend can be folded and compressed in the axial direction. In the portion located on the outer diameter side of the bend, the spiral uneven region is pulled outward along the axial direction, causing the uneven structure to be smoothed out and stretched. Thus, the second tube 12 having the spiral uneven region 124 can flexibly follow bending, and therefore has high kink resistance.

[0078] The ratio of the distance from the second inner surface to the central axis C at the deepest part of the radially recessed portion, which is part of the helical recess 124b, to the distance from the second inner surface to the central axis C at the apex of the radially protruding portion, which is part of the helical convex portion 124a, is not particularly limited, but is, for example, within the range of 50% to 80%.

[0079] The ratio of the length of the spiral groove region 124 to the total length of the second tube 12 is, for example, within the range of 50% to 100%.

[0080] In a cross-section along the axial direction of the helical uneven region 124, the spacing along the axial direction between radially protruding portions that make up a part of the helical protrusions 124a (helical protrusion arrangement spacing) is preferably 0.5 mm or more and 10.0 mm or less.

[0081] The spacing of the spiral protrusions can be measured in the same manner as the spacing 123c described earlier. In the measurement method, the vertex of a protrusion is defined as the point furthest from the central axis C in the radially protruding portion that makes up a part of the spiral protrusion 124a, in a cross-section along the axial direction of the spiral uneven region 124.

[0082] The helical uneven region 124 is provided with at least one through hole 122 that penetrates from the second inner circumferential surface 12a to the second outer circumferential surface 12b. The through hole 122 can be the same type of through hole as described in the first embodiment.

[0083] Therefore, the bubbler tube according to the second embodiment, like the bubbler tube according to the first embodiment, can reduce pressure loss and exhibit high kink resistance. Since the bubbler tubes according to each embodiment are less prone to kinking, they are also superior in terms of installation flexibility.

[0084] (Method for manufacturing a bubbler tube according to the second embodiment) The bubbler tube according to the second embodiment can be manufactured in the same manner as the first embodiment, except that, for example, a helical uneven region is formed instead of an independent peak region during the manufacturing of the second tube.

[0085] The spiral ridge region can be formed, for example, by blow molding. Blow molding can be performed in the same manner as the formation of the independent peak region described earlier, except that the inner surface of the mold is shaped to correspond to the outer surface shape of the desired spiral ridge region.

[0086] (Third embodiment) According to the third embodiment, a bubbler tube is provided. The bubbler tube according to the third embodiment will be described with reference to Figure 5.

[0087] The bubbler tube 10 according to the third embodiment further comprises a third tube 13 in addition to the bubbler tube according to the first embodiment or the bubbler tube according to the second embodiment. That is, the bubbler tube 10 comprises a first tube 11, a second tube 12, and a third tube 13.

[0088] Figure 5 illustrates a case where the second tube 12 is a bubbler tube 10 having independent peak regions 123, i.e., a bubbler tube according to the first embodiment. However, the bubbler tube 10 according to the third embodiment may have a second tube 12 having a spiral uneven region instead of a second tube 12 having independent peak regions 123.

[0089] The bubbler tube 10 according to the third embodiment may further include an intermediate layer 14, a fused portion 15, and a fluororesin-containing cap 16, as shown in Figure 5, for example.

[0090] The third tube 13 has a third inner surface 13a and a third outer surface 13b. The third tube 13 is a cylindrical tube having a predetermined inner diameter and outer diameter. For example, in the bubbler tube 10 shown in Figure 5, the inner diameter of the third tube 13 is larger than the outer diameter of the first tube 11, but is not limited to this. For example, the inner diameter of the third tube 13 may be larger than the outer diameter of the second tube 12 and smaller than the inner diameter of the first tube 11.

[0091] The third tube 13 is connected to the bubbler tube according to the first embodiment, for example, as follows: In the bubbler tube 10 according to the third embodiment, the first tube 11 and / or the second tube 12 are inserted into the third tube 13. The second tube 12 may be externally inserted into the third tube 13.

[0092] Figure 5 shows, as an example, a case in which the first tube 11 and the second tube 12 are inserted into the third tube 13. In the bubbler tube 10, the other end 121 of the second tube 12 protrudes outward along the axial direction compared to the other end 111 of the first tube 11. Therefore, at the other end 121 of the second tube, the second outer surface 12b faces the third inner surface 13a via the intermediate layer 14. At the other end 111 of the first tube, the first outer surface 11b faces the third inner surface 13a via the intermediate layer 14. The intermediate layer 14 is fused to the first outer surface 11b, the second outer surface 12b, and the third inner surface 13a.

[0093] As described above, if the intermediate layer 14 is connected to the second tube 12 by crossing the other end 111 of the first tube 11, then both the first tube 11 and the second tube 12 are joined to the third tube 13 via the intermediate layer 14. Therefore, even when the bubbler tube 10 is bent, displacement of the second tube 12 inserted inside the first tube 11 can be suppressed. In this case, the intermediate layer 14 can be fused to the second outer surface 12b and / or the other end 121 of the second tube 12.

[0094] The intermediate layer 14 can also be called a spacer. The intermediate layer 14 may be formed, for example, in at least a portion of the portion where the third inner surface 13a and the first outer surface 11b face each other, and in the portion where the third inner surface 13a and the second outer surface 12b face each other. That is, at least one of the first tube 11 and the second tube 12 can be joined to the third tube 13 via the intermediate layer 14. A portion of the intermediate layer 14 may be further formed in the portion where the third inner surface 13a and the first outer surface 11b do not face each other.

[0095] The intermediate layer 14 has a cylindrical shape, for example, that covers the third inner circumferential surface 13a of the third tube 13.

[0096] The intermediate layer 14 includes, for example, a molten-flowable fluororesin. As the molten-flowable fluororesin included in the intermediate layer 14, at least one molten-flowable fluororesin selected from the group consisting of PFA, ETFE, FEP, and PVDF can be used.

[0097] The thickness of the intermediate layer 14 is not particularly limited, but is, for example, within the range of 0.005 mm to 5.0 mm. When the inner diameter of the third tube is large and the outer diameter of the tube joined to the third tube 13 is small, it is preferable to form an intermediate layer 14 with a relatively large thickness. This can fill the gap at the joint and suppress the formation of wrinkles, etc. Therefore, when used as a bubbler, gas leakage at the joint and the intrusion of chemicals, etc. into the tube can be suppressed. On the other hand, when the inner diameter of the third tube is small and the outer diameter of the tube joined to the third tube is large, the gap at the joint can be filled with an intermediate layer 14 with a relatively small thickness.

[0098] The presence of the intermediate layer 14 makes the joint between the third tube 13 and the first tube 11 and / or the second tube 12 stronger. Therefore, even when used in an installation method that reduces the bending radius of the bubbler tube 10, for example, gas leakage from the joint between the first tube 11 and / or the second tube 12 and the third tube 13 can be suppressed.

[0099] Furthermore, the bubbler tube according to the third embodiment does not need to have an intermediate layer 14. In this case, for example, the third tube 13 can be made of a molten-flowable fluororesin, and the end of the third tube 13 can be fused to the first outer surface 11b to form a fused portion 15. In this way, the tubes can be joined together by directly fusing them together without separately providing an intermediate layer 14.

[0100] The fused portion 15 may be a portion where the third tube 13 itself has melted, or it may be a portion where the intermediate layer 14 has melted. It may also be a portion containing a separately prepared molten-flowable fluororesin.

[0101] The fused portion 15 may contain at least one molten-flowable fluororesin selected from the group consisting of PFA, ETFE, FEP, and PVDF. A fused portion 15 containing a molten-flowable fluororesin is preferred because it can exhibit an anchoring effect to the first tube 11. It is more preferable that the fused portion 15 contains PFA, which has excellent chemical resistance and heat resistance.

[0102] In addition, the third tube 13 may be connected only to the second tube 12, for example. Figure 5 shows a case where the other end 121 of the second tube 12 protrudes outward along the axial direction more than the other end 111 of the first tube 11, but the other end 111 of the first tube 11 may protrude outward along the axial direction more than the other end 121 of the second tube 12. That is, the other end 121 of the second tube 12 may be covered by the first tube 11. In this case, the third tube 13 may be connected only to the first tube 11.

[0103] As described above, one end 130 of the third tube 13 is connected to at least one of the other end 111 of the first tube 11 and the other end 121 of the second tube 12.

[0104] A fluororesin-containing cap 16 is fused to one end 110 of the first tube and one end 120 of the second tube. This seals and fixes one end 110 of the first tube 11 and one end 120 of the second tube 12.

[0105] As shown in Figure 5, the fluororesin-containing cap 16 seals one end 110 of the first tube 11, thereby suppressing the release of gas that could be released from one end 110 of the first tube 11 to the outside of the bubbler tube 10.

[0106] Figure 5 shows, as an example, a case in which one end 120 of the second tube 12 protrudes outward in the axial direction more than one end 110 of the first tube 11 inside the fluororesin-containing cap 16. Inside the fluororesin-containing cap 16, one end 110 of the first tube 11 may protrude outward in the axial direction more than one end 120 of the second tube 12.

[0107] The size and shape of the fluororesin-containing cap 16 are not particularly limited.

[0108] The fluororesin contained in the fluororesin-containing cap 16 is not particularly limited, but for example, it is a molten-flowable fluororesin. As the molten-flowable fluororesin, for example, the type described above can be used for the fused portion 15.

[0109] In the third embodiment, the bubbler tube is preferably sealed at one end 110 of the first tube and one end 120 of the second tube by a fluororesin-containing cap 16, and the intermediate layer 14 is fused to the third inner circumferential surface 13a and fused to the second tube 12, straddling the other end 111 of the first tube 11. In this configuration, both ends of the first tube 110 and the second tube 120, and the other end 111 of the first tube and the other end 121 of the second tube can be fixed. Therefore, when the bubbler tube 10 is bent, it is less likely that displacement will occur between the first tube 11 and the second tube 12. Although not shown, instead of having a fluororesin-containing cap 16, one end 110 of the first tube 11 may be sealed by ultrasonic welding with the edges of the tubes overlapping. The same may apply to one end 120 of the second tube.

[0110] Depending on the application of the bubbler tube 10, the fluororesin-containing cap 16 may be omitted. Furthermore, the third tube 13 may be connected to both the other end 101 and the one end 100 of the bubbler tube. In this configuration, for example, the bubbler tube 10 can be used to supply gas from both ends. Note that the fluororesin-containing cap 16 may be attached to a bubbler tube that does not have the third tube 13. That is, it may be attached to one end of the bubbler tube according to the first or second embodiment described above.

[0111] In the bubbler tube 10, the portion of the first tube 11 that is exposed is the bubbling portion 30. Figure 5 shows an example where the entire wall surface of the first tube 11 is occupied by a porous region. In the bubbler tube 10, the portion of the first tube 11 where the porous region is exposed is the bubbling portion 30.

[0112] The apparent specific gravity of the bubbling section 30 in the bubbler tube 10 is, for example, within the range of 0.10 to 2.0. The apparent specific gravity of the bubbling section 30 may also be within the range of 0.11 to 1.87. It is desirable that the apparent specific gravity of the bubbling section 30 is greater than the specific gravity of the chemical solution in which the bubbling section 30 is immersed. In this case, even if bubbling is performed while the bubbling section 30 is immersed in the chemical solution, it is possible to suppress the bubbling section 30 from floating up. That is, it is possible to suppress the decrease in mixing efficiency due to bubbling. Therefore, it is not necessary to fix the bubbler tube from the outside, and the degree of freedom in installation can be increased.

[0113] The specific gravity of a tube can be measured by the submersion method.

[0114] For example, when gas is supplied from the other end 101 of the bubbler tube 10, the gas flows from the other end 131 of the third tube 13 towards its first end 130. The first end 130 of the third tube is connected to the bubbler tube according to the first embodiment or the bubbler tube according to the second embodiment. Therefore, the gas supplied into the third tube 13 flows into the second tube 12 from the other end 121 side, passes between the second tube 12 and the first tube 11, and is then released to the first outer surface 11b side through the porous structure of the first tube 11.

[0115] The bubbler tube according to the third embodiment includes the bubbler tube according to the first embodiment or the bubbler tube according to the second embodiment, thereby providing a bubbler that has high kink resistance and can suppress gas pressure loss.

[0116] The material and other details of the third tube are described below.

[0117] (Third tube) The third tube 13 contains a fluororesin. The third tube may be made of a fluororesin.

[0118] The third tube 13 is preferably a tube with a non-porous structure (solid structure). When the third tube 13 has a non-porous structure, for example, it is possible to prevent the gas supplied into the bubbler tube 10 from leaking out from the wall surface of the third tube 13. Therefore, with the bubbler tube 10 shown in Figure 5, it is possible to inject gas into the chemical solution from the bubbling section 30 while suppressing the leakage of gas supplied from the other end 101 of the bubbler tube into the atmosphere.

[0119] In addition, if the third tube 13 does not have a porous structure, various commonly used devices such as flanges and nuts can be easily attached to or processed on the other end 131 of the third tube 13. Therefore, the installation cost of the bubbler tube according to the embodiment can be reduced.

[0120] The non-porous structural portion included in the third tube 13 may, for example, occupy 50% or more by volume, 80% or more by volume, or 100% by volume of the third tube 13.

[0121] The inner diameter of the third tube 13 is not particularly limited, but is, for example, within the range of 0.7 mm to 40 mm. The outer diameter of the third tube 13 is not particularly limited, but is, for example, within the range of 1.3 mm to 50 mm. It is preferable that the inner diameter of the third tube 13 is larger than the outer diameter of the first tube 11.

[0122] The wall thickness of the third tube 13 is, for example, within the range of 0.3 mm to 5.0 mm. The wall thickness of the third tube 13 is defined by the radial distance from the inner circumferential surface 13a of the third tube 13 to the nearest outer circumferential surface 13b.

[0123] The length of the third tube 13 is not particularly limited, but is, for example, within the range of 0.1m to 5.0m.

[0124] The fluororesin contained in the third tube 13 can be, for example, at least one selected from the group consisting of polytetrafluoroethylene (PTFE), modified PTFE, perfluoroalkoxyalkane (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroethylenepropene copolymer (FEP), and polyvinylidene fluoride (PVDF). PFA is preferred because it has excellent chemical resistance and heat resistance. Furthermore, if the third tube contains PFA, for example, a fused portion 15 can be formed even when the third tube and the first tube are directly fused without interposing an intermediate layer 14, thereby enabling an anchoring effect on the porous structure of the first tube 11.

[0125] The other end 131 of the third tube 13 may be the other end 101 of the bubbler tube 10.

[0126] The total length of the bubbler tube 10 is defined, for example, from one end 110 of the first tube 11 to the other end 131 of the third tube 13. If one end 110 of the first tube 11 is equipped with a fluororesin-containing cap 16, the total length of the bubbler tube 10 shall include the length of the fluororesin-containing cap 16. The total length of the bubbler tube 10 is not particularly limited, but is, for example, within the range of 0.2m to 10m.

[0127] The bubbling section 30 described above may be the portion of the bubbler tube 10 where the first outer surface 11b of the first tube 11 is exposed. The length of the bubbling section 30 is not particularly limited, but is, for example, within the range of 0.1m to 5.0m.

[0128] (Method for manufacturing a bubbler tube according to the third embodiment) A bubbler tube according to the third embodiment can be manufactured, for example, as follows. As an example, a case in which the bubbler tube according to this embodiment includes a bubbler tube according to the first embodiment will be described. The bubbler tube according to this embodiment may include a bubbler tube according to the second embodiment instead of a bubbler tube according to the first embodiment.

[0129] The third tube can be manufactured, for example, using the fluororesin described above, by known molding methods such as extrusion molding or injection molding.

[0130] The other end of the bubbler tube according to the first embodiment is inserted into one end of the fabricated third tube. That is, of the bubbler tubes 10 according to the first embodiment shown in Figure 1, at least one of the other end 111 of the first tube and the other end 121 of the second tube is inserted into one end of the third tube.

[0131] The bubbler tube 10, which further includes the intermediate layer 14 shown in Figure 5, can be manufactured, for example, as follows.

[0132] First, a dispersion containing fluororesin particles is prepared to form the intermediate layer 14. It is preferable to use the molten-flowable fluororesin particles described above.

[0133] The dispersion comprises a dispersion medium and molten-flowable fluororesin powder in the dispersion medium. As the molten-flowable fluororesin powder, materials commonly used in methods for forming resin tubes by coating, such as the dip coating method, can be used. For example, the dispersion is an aqueous dispersion obtained by dispersing molten-flowable fluororesin powder in an aqueous dispersion medium by emulsion polymerization.

[0134] The dispersion medium may be, for example, water. The composition of the dispersion is not particularly limited, and for example, a dispersion or suspension with a composition commonly used in methods such as dip coating can be used. The dispersion may or may not contain fillers or additives that are different from the molten-flowable fluororesin powder.

[0135] In the other end of the bubbler tube according to the first embodiment, the above-mentioned dispersion is applied to the portion of the first tube 11 and the second tube 12 whose outer surface is exposed to form a coating film. That is, the coating film is formed on at least one of the first outer surface 11b and the second outer surface 12b.

[0136] Next, the other end of the bubbler tube according to the first embodiment is inserted into one end of the third tube 13, and at least a portion of the coating is covered with the third inner circumferential surface 13a. After that, the portion (joint) where one end of the bubbler tube according to the first embodiment is inserted into the third tube 13 is subjected to heat treatment. In this way, an intermediate layer 14 can be formed on at least a portion of the portion where the first outer circumferential surface 11b and the third inner circumferential surface 13a face each other, and the portion where the second outer circumferential surface 12b and the third inner circumferential surface 13a face each other.

[0137] The method for joining the bubbler tube and the third tube 13 according to the first embodiment is not limited to fusion bonding by the intermediate layer 14 described above. For example, the other end of the bubbler tube according to the first embodiment, which does not have a coating film formed on it, can be inserted into the third tube, and the first tube 11 and / or the second tube 12 can be fused to one end of the third tube by heat treatment at a temperature above the melting point of the fluororesin constituting the third tube 13.

[0138] (Fourth embodiment) According to the fourth embodiment, a bubbler is provided. The bubbler comprises a bubbler tube according to the third embodiment and a gas supply means. The gas supply means is connected to the other end of the third tube. The bubbler may also have two gas supply means. That is, gas supply means may be provided at one end and the other end of the bubbler tube, respectively.

[0139] The type of gas supply means is not particularly limited. The gas supply means may be a conventionally known device or the like. The gas supply means is, for example, a device that can release a gaseous material at a constant supply rate per unit time. The gaseous material can be supplied from the device through a gas supply pipe into the bubbler tube according to the third embodiment.

[0140] The type of gas supplied can be changed as appropriate depending on the purpose of the bubbler, but is at least one selected from the group consisting of, for example, air, nitrogen, ozone gas, and ammonia.

[0141] Figure 6 is a schematic diagram showing an example of a bubbler according to the fourth embodiment. In the bubbler shown in Figure 6, a gas supply means 40 is connected to the other end of the third tube 13 of the third bubbler tube via a gas supply pipe 41. A device such as a one-touch fitting may be installed at the connection between the other end of the third tube 13 and the gas supply pipe 41 as needed.

[0142] The first tube 11 of the bubbler tube is immersed in the liquid material 43 stored in the container 42. In this state, by supplying gas from the gas supply means 40 into the bubbler tube, the gas can be diffused into the liquid material 43 through the porous wall surface of the first tube 11. In other words, bubbling can be performed.

[0143] The type of liquid material can be changed as appropriate depending on the purpose of the bubbler, but examples include resists used in semiconductor manufacturing, developers, organic solvents, various aqueous solutions, strong acids, and strong alkalis. One example of an aqueous solution is sodium hypochlorite solution.

[0144] The apparent specific gravity of the bubbling section 30 described above, that is, the portion of the bubbler tube where the first outer surface 11b is exposed, is preferably greater than that of the liquid material 43. In this case, it is possible to suppress the bubbling section from floating up to near the liquid surface, which would reduce the efficiency of stirring the liquid material by bubbling.

[0145] The bubbler according to the fourth embodiment includes a bubbler tube according to the third embodiment. Therefore, it is easy to bend the tube to match the installation shape and move it within the liquid material 43 stored in the container 42, and it is less likely to kink during bending and movement. In other words, the fourth embodiment provides a bubbler that has excellent chemical resistance and heat resistance, high kink resistance, and can suppress gas pressure loss.

[0146] It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple constituent elements disclosed. For example, if the problem can be solved and effects obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention. [Explanation of Symbols]

[0147] 10... Bubbler tube, 11... First tube, 11a... First inner surface, 11b... First outer surface, 12... Second tube, 12a... Second inner surface, 12b... Second outer surface, 13... Third tube, 13a... Third inner surface, 13b... Third outer surface, 14... Intermediate layer, 15... Fusion joint, 16... Fluororesin-containing cap, 30... Bubbling section, 10 0...one end, 101...the other end, 110...one end, 111...the other end, 120...one end, 121...the other end, 122...through hole, 123...independent peak region, 124...spiral uneven region, 130...one end, 131...the other end, 122a...through hole diameter, 123a...protrusion, 123b...recess, 123c...arrangement spacing, 124a...spiral protrusion, 124b...spiral recess, C...central axis.

Claims

1. A bubbler tube comprising a first tube having a first inner surface and a first outer surface, and a second tube having a second inner surface and a second outer surface, The first tube contains polytetrafluoroethylene and has a porous region that extends from the first inner surface to the first outer surface. The second tube has independent mountain regions having a plurality of protrusions that are independent of each other and project radially in the direction of the second tube, and a plurality of recesses provided between the plurality of protrusions, and the plurality of protrusions and the plurality of recesses are arranged alternately along the axial direction from one end to the other end of the second tube. The isolated mountain region is provided with at least one through hole that penetrates from the second inner surface to the second outer surface. The first tube is a bubbler tube that covers at least a portion of the independent mountain region so as to cover at least one of the through holes.

2. A bubbler tube comprising a first tube having a first inner surface and a first outer surface, and a second tube having a second inner surface and a second outer surface, The first tube contains polytetrafluoroethylene and has a porous region that extends from the first inner surface to the first outer surface. The second tube has a spirally convex region having spiral protrusions and spiral recesses that extends spirally along the axial direction from one end to the other end of the second tube. The aforementioned spiral uneven region is provided with at least one through hole that penetrates from the second inner surface to the second outer surface. The first tube is a bubbler tube that covers at least a portion of the spiral uneven region so as to cover at least one of the through holes.

3. The number of the aforementioned at least one through-holes is multiple, The bubbler tube according to claim 1 or 2, wherein the plurality of through holes are arranged along the axial direction.

4. The bubbler tube according to claim 1, wherein the spacing between the arrangement of the plurality of protrusions is 1.0 mm or more and 20.0 mm or less.

5. The bubbler tube according to claim 1 or 2, wherein the portion of the second tube other than the through-hole has a non-porous structure with a porosity of less than 5%.

6. The bubbler tube according to claim 1 or 2, wherein the average diameter of the at least one through hole is 1.0 mm or more and 3.0 mm or less.

7. The bubbler tube according to claim 1 or 2, wherein the porosity of the porous region is 5% or more and 80% or less.

8. It also features a cap containing fluororesin. The bubbler tube according to claim 1 or 2, wherein the fluororesin-containing cap is fused to one end of the first tube and one end of the second tube.

9. It has a non-porous structure and further comprises a third tube containing a molten-flowable fluororesin. The bubbler tube according to claim 1 or 2, wherein one end of the third tube is connected to at least one of the other end of the first tube and the other end of the second tube.

10. One end of the third tube is connected to the other end of the first tube. The bubbler tube has an intermediate layer interposed between the first outer surface of the first tube and the third inner surface of the third tube. The bubbler tube according to claim 9, wherein the intermediate layer is fused to the second tube, straddling the other end of the first tube.

11. A bubbler tube according to claim 9, Equipped with a gas supply means, The gas supply means is a bubbler connected to the other end of the third tube.

12. A bubbler for bubbling liquid materials, In the bubbler tube, the portion of the first tube that is exposed is the bubbling portion. The bubbler according to claim 11, wherein the apparent specific gravity of the bubbling portion is greater than that of the liquid material.

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