Diaphragm for electrolytic plating

Abstract

To increase the strength of the joints of diaphragms for electrolytic plating, which are formed in a bag-like or basket-like shape using sheet material. [Solution] The electroplating diaphragm of this invention is formed into a container shape by overlapping and welding the ends of sheet materials 2a and 2b together, and is an electroplating diaphragm that isolates the two electrodes by housing an anode electrode or a cathode electrode inside, and is provided with a joining piece 3 that is bent inward from the outside to the overlapping ends of the sheet materials 2a and 2b and covers the outer end of the said ends, and the opposing overlapping surfaces of the joining piece 3 and the ends of the sheet materials 2a and 2b are welded together integrally as a welding surface F. In some cases, a connecting piece 3 is extended from the end of at least one of the overlapping sheet materials 2a, and the connecting piece 3 is folded and formed to overlap with the end of the other sheet material 2b.

Description

Technical Field

[0001] The present invention relates to an electrolytic plating diaphragm for removing impurities in an electrolytic solution by partitioning the anode side and the cathode side in an electrolytic cell used for electrolytic plating.

Background Art

[0002] Generally, when performing electrolytic plating by immersing an object to be plated in an electrolytic solution, such as when forming a conductive circuit on the surface of a semiconductor substrate by electrolytic plating, a diaphragm for removing impurities that inhibit electrolytic plating in the electrolytic solution is disposed between the anode side and the cathode side.

[0003] As the above-mentioned electrolytic plating diaphragm, as shown in Patent Document 1, a separate membrane body is known in which a polyethylene non-woven fabric is sandwiched between PVDF (polyvinylidene fluoride resin) porous bodies, and a reinforcing support frame made of PVDF resin is overlapped on one side and welded by ultrasonic vibration.

[0004] Furthermore, Patent Document 2 discloses a liquid purification method for recovering heavy metals from liquids such as industrial wastewater and seawater containing heavy metals, which are environmental pollutants, by applying the principle of the electrolytic plating diaphragm. As the electrolytic diaphragm used in this purification device, a bag-shaped diaphragm unit that isolates the space between both electrodes by accommodating or surrounding one of the electrodes on the anode side and the cathode side is shown. This bag-shaped diaphragm unit is formed in a bag shape by overlapping flat film-like materials and bonding, welding, or sewing the overlapping surfaces of the outer peripheral edges thereof (see FIGS. 8 and

[0024] in Patent Document 2).

[0005] Also, when forming a bag shape by overlapping the above-mentioned plastic flat film materials and welding or adhesively joining the overlapping surfaces of the overlapping ends, as shown in FIG. 8, the overlapping surfaces of the joint portion 21a of the pair of plastic flat film sheets 21 made of non-woven fabric or the like are directly joined or a strip-shaped joining material 22 made of a homogeneous material is inserted between the overlapping surfaces (joined by "butting") and integrally press-joined by adhesion or welding. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2002-275693 (

[0009] , Figures 1-5) [Patent Document 2] Japanese Patent Publication No. 5235276 (

[0001] ,

[0002] , Figure 8) [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the overlapping peripheral joint structure shown in Patent Document 2 or Figure 5 has the disadvantage that the strength of the joint surface due to adhesion or welding is low, and when electrodes are inserted into or removed from the inside of the bag-like structure or when outward pressure is applied from the inside, delamination of the joint surface or tearing of the film material at the joint boundary is likely to occur.

[0008] Furthermore, even when suturing the overlapping edges as shown in Patent Document 2, the flat membrane material is prone to tearing, similar to or even worse than with adhesive or welding, and the suturing process itself is costly. [Means for solving the problem]

[0009] The present invention, which solves the above problems, is firstly an electrolytic plating diaphragm formed in a container shape by overlapping and welding the ends of sheet materials 2a and 2b together, and which isolates the two electrodes by housing an anode electrode or a cathode electrode inside, characterized in that a joining piece 3 is provided which is bent inward from the outside to the overlapping ends of the sheet materials 2a and 2b and covers the outer end of said ends, and the overlapping opposing surfaces of the joining piece 3 and the ends of the sheet materials 2a and 2b are welded together integrally with each other as a welding surface F.

[0010] Secondly, the invention is characterized by extending a connecting piece 3 from the end of at least one sheet material 2a that is to be overlapped, and bending the connecting piece 3 so as to overlap the end of the other sheet material 2b.

[0011] Thirdly, the end of the sheet material 2b on the other side, over which the joining piece 3 formed on the sheet material 2a on the other side is placed, is made into a joining piece 3' that is folded back along the folded inner surface of the joining piece 3 and inserted, and the folded inner surfaces of the inserted joining piece 3' are made into a non-welded surface.

[0012] Fourth, the overlapping surfaces of the ends of the overlapping sheet materials 2a and 2b are designated as non-welded surfaces, and a joining piece 3 made of a separate material from the sheet materials 2a and 2b is provided, which is folded so as to cover the outer edges and upper and lower surfaces of the overlapping ends, and the upper and lower surfaces of the ends of the sheet materials 2a and 2b and the inner surface of the joining piece 3 that overlaps these upper and lower surfaces are each designated as welded surfaces F and are integrally welded together. [Effects of the Invention]

[0013] As described above, the present invention has the advantage of significantly increasing the strength when circumferential tension is applied to the joint of the sheet material of the bag compared to a method in which the overlapping surfaces of the periphery of the overlapping edges (hence the term "facing each other") in the upper and lower directions that seal the bag-shaped diaphragm are welded together. [Brief explanation of the drawing]

[0014] [Figure 1] This is an overall perspective view showing one example of a bag-like diaphragm of the present invention. [Figure 2] This is an enlarged cross-sectional view showing an example of a welded structure for a sheet material with a bag-like diaphragm. [Figure 3] This is also a diagram of the sheet material of the same diaphragm. [Figure 4] This is an unfolded diagram showing another embodiment of the material cutting and folded shape of the sheet material for the bag-shaped diaphragm. [Figure 5] This is a cross-sectional view showing another embodiment of the welding structure for sheet material. [Figure 6] It is a cross-sectional view showing another embodiment of the welding structure. [Figure 7] It is a cross-sectional view showing another embodiment of the welding structure. [Figure 8] It is a cross-sectional view of a conventional bag-shaped diaphragm.

Mode for Carrying Out the Invention

[0015] Figs. 1 to 3 show one embodiment of this invention. The diaphragm 1 for electrolytic plating is formed in a bag shape by a sheet material 2 (2a, 2b) obtained by applying a solution containing a film material to a pair of front and back plastic non-woven fabric base materials as shown in the developed view of Fig. 3. By accommodating either the anode electrode or the cathode electrode in the electrolytic cell during electrolytic plating and isolating the space between the two electrodes, impurities in the electrolytic solution are filtered and collected, and inhibitors for electrolytic plating are removed.

[0016] As the above film material, for example, polyvinylidene fluoride, titanium oxide, sucrose fatty acid ester, etc. are used, and as the base material, polyethylene (PET), etc. are similarly used. The film thickness is, for example, 0.17 mm or 0.22 mm, etc., depending on the specifications.

[0017] In this example, as shown in Fig. 3, the sheet material 2 is formed by folding sheet materials 2a and 2b, which are rectangular in the vertical direction and divided vertically (or front and back) through the middle horizontal fold L1, into a bag shape and overlapping them. On the overlapping surfaces (welding surfaces) F, F (note: shown by hatching in Fig. 3), which are one side of the strip-shaped areas formed at the folded left and right edges, the sheet materials 2 on each of the front and back sides are welded, for example, by high-frequency welding, ultrasonic welding, or other heat welding. In the example shown in Fig. 2, the joining pieces 3 on the left side of the upper sheet material 2a (the rear or back sheet of the bag) and the right side of the lower sheet material 2b (the front or front sheet of the bag) are folded back and overlapped so as to cover each other on the surface side. The overlapping surface F inside each of the above joining pieces 3 is folded and overlapped with the overlapping surface on the outer side (the outside of the bag) on the opposite upper and lower sides so that the left end of the sheet material 2a covers downward and the right end of the sheet 2b covers upward.

[0018] The inner joining piece 3' that is inserted in a bent state on the inner surface side with respect to the outer joining piece 3 covering the surface side is extended to the end on the opposite side of the outer joining piece 3 of each sheet material 2a, 2b, and the surface facing the inner surface of each corresponding outer joining piece 3 becomes the welding surface F, and they are overlapped and welded together as described later.

[0019] Furthermore, in this example, a vertical fold L2 is formed at approximately the center of the left and right widths of the outer joining piece 3, and it is bent and formed into an outwardly mountain-shaped V-shape and L-shape (see Fig. 2). And the overlapping surface F and the outer surface of the inner joining piece 3' that is vertically opposite and overlaps with the overlapping surface F (not shown in Fig. 3) become the welding surfaces F that weld to each other.

[0020] Also, in the example shown in Figs. 1 to 3, a welding sheet 4 that is integrally welded to both sides is inserted between the overlapping surfaces F, F of the joining pieces 3, 3' on the left and right of the sheet material 2. The welding sheet 4 is bent into the same shape through a central vertical fold L3, and the overlapping surfaces F, F of the joining pieces 3, 3' are in close contact, and the whole is integrally and firmly welded and fixed, and the sheet materials 2a, 2b are formed into a bag shape. Therefore, both the front and back surfaces of the welding sheet 4 become the welding surfaces (indicated by hatching) F.

[0021] However, since sufficient strength can usually be obtained without using the welding sheet 4, the welding sheet 4 is used when the strength required according to the material and thickness of the sheet material, the shape, size, weight of the plating object, and other plating working conditions is insufficient.

[0022] Incidentally, compared with the tensile strength of 8.4 N / cm when the sheet materials 2a, 2b described above are adhered by the method shown in Fig. 8, the implementation product of the present invention without the welding sheet is 25.3 N / cm, which has about three times the strength, and usually sufficient strength can be obtained without inserting the welding sheet 4.

[0023] As shown in the figure, the diaphragm 1 is constructed by folding two sheets of material 2a and 2b, which are made by dividing a single rectangular sheet material 2 into upper and lower sections by a horizontal fold L1 in the middle of the longitudinal direction. The upper sheet material 2a in Figure 3 (the back side in Figure 1) has its left outer joining piece 3 folded downwards, and the lower sheet material 2b in Figure 3 (the front side in Figure 1) has its right outer joining piece 3 folded upwards, thereby covering the two sheets.

[0024] In contrast, at the end of each sheet material 2a, 2b opposite to the joining piece 3, an inner joining piece 3' is provided, which is folded in the same manner as above along a valley-shaped fold L'2 in the vertical direction. This joining piece 3' is located inside the surface-side joining piece 3, overlapping with the joining piece 3, and its mountain-shaped outer surface serves as the welding surface F, and it is integrally welded and fixed to the joining piece 3.

[0025] The upper and lower joining pieces 3, 3' are welded together by known heat welding as described above. At this time, the overlapping portions of the V-shaped cross-sections at both ends of the sheet material 2 can be welded together by any method, such as by heating and pressing with interlocking concave and concave pressing tools 6a, 6b.

[0026] In actual use, either the cathode electrode or the ANO electrode is inserted into the bag-shaped diaphragm 1, and the device is immersed in an electrolyte solution to perform electroplating or an application of the principle of electroplating, such as removing heavy metal circuits from liquids.

[0027] Figure 4 shows another embodiment of the material preparation and folded shape of the bag-shaped diaphragm 1. In this example, a rectangular sheet material 2 is folded horizontally along a vertical crease L1 in the longitudinal center, forming outer joining pieces 3,3 on the left and lower ends of the left sheet material 2a, and inwardly housed joining pieces 3',3' on the right and lower ends of the right sheet material 2b. A welded sheet 4, similar to that described above, is interposed between each of the joining pieces 3 and 3'. This example also shows how to form a bag-shaped diaphragm with an open top by welding at the welded surface F indicated by hatching.

[0028] The processing of each part of the bag-shaped diaphragm other than those described above, and the overall molding method are the same as those described in the embodiments with respect to Figures 1 to 3 above. Parts with the same function are represented by the same reference numerals as in those embodiments, and the explanation of overlapping parts has been omitted (this is also the case in the examples shown in Figures 5 to 7).

[0029] Figures 5 to 7 are cross-sectional views showing other embodiments of the overlapping and welded structure of the diaphragm sheet materials. Figure 5 shows the upper and lower (or front and back) sheet materials 2a and 2b constituting the peripheral wall, with their left and right ends overlapped with a release agent (release sheet) 7 in between, and a separate, independent sheet-like joining piece 3 is folded into a U-shape or V-shape and placed over both ends of the overlapped sheet materials 2a and 2b.

[0030] As shown in Figure 5, the left and right ends of the sheet materials 2a and 2b are placed on the welding table 8, and heated and pressed from above with a heating tool 9, thereby integrally welding the upper and lower surfaces (welding surfaces F) of both ends of the upper and lower sheet materials 2a and 2b to the inner surface (welding surface F) of the joining piece 3. At this time, welding between the upper and lower sheet materials 2a and 2b is prevented by the interposition of the release sheet 7, and they become non-welded surfaces. As previously described, the heating tool 9 may be a high-frequency electrode, an ultrasonic horn, or any other heating and pressing tool.

[0031] Figure 6 also shows another embodiment, illustrating the overlapping structure of the sheet materials 2a and 2b of the diaphragm 1. In this example, the upper and lower sheet materials 2a and 2b are overlapped within the bags at both ends via the release sheet 7, similar to the example shown in Figure 5. However, at the left end, the left end of the lower sheet material 2a is folded upward, covering the release sheet 7 and the left end of the upper sheet material 2b in an overlapping state. On the other hand, at the right end, the right end of the upper sheet material 2b is folded downward, covering only the release sheet 7, and the lower sheet material 2a is overlapped onto the lower surface of the joining piece 3 formed there.

[0032] In this state, both ends of the sheet materials 2a and 2b are placed on the welding table 8, and heated and pressed from above with the heating tool 9 as described above, thereby integrally welding the upper surfaces of both ends of the upper sheet material 2b and the welding surfaces F, F of the inner surface of the folded end of the joining piece 3 together. In this example, the lower left end surface of the upper sheet material 2b and the inner bottom surface of the left end of the lower sheet material 2a opposite to this surface, and the inner surface of the folded end (joining piece 3) at the right end of the upper sheet material 2b become non-welded surfaces due to the release sheet 7.

[0033] Figure 7 shows yet another embodiment of the present invention, in which both the left and right ends of the lower sheet material 2b are folded inward to form pleats on the upper surface to form inner joining pieces 3' which are inserted inside, and a release sheet 7 is inserted into the inner surface of the folded portion, while both the left and right ends of the upper sheet material 2a are folded over the folded portions (inner joining pieces 3') of the lower sheet material 2b from the outside downward to form outer joining pieces 3.

[0034] In this state, the overlapping ends of the upper and lower sheet materials 2a and 2b are placed on the welding table 8 and heated and pressed with the heating tool 9 to integrally weld and join the ends of the upper and lower sheet materials 2a and 2b. In this case, the welding surface F on the inner surface of the outer joining piece 3 which extends integrally with the upper sheet material 2a is welded on two surfaces with the welding surfaces F on the upper and lower ends of the lower sheet material 2b which is folded upwards inside. Otherwise, it is the same as the case shown in Figure 6. In the example shown in Figure 7, the folded inner surface (inner surface of the pleat) of the lower sheet material 2b becomes a non-welded surface due to the release sheet 7.

[0035] Furthermore, although the above embodiments have all been shown for bag-shaped diaphragms, it is also possible to manufacture (cage-shaped diaphragms) with cylindrical or rectangular walls and bottoms. In these cases, the sheet material for the wall does not necessarily need to be bent in a V-shape at the joint as in the bag-shaped diaphragm; it is sufficient to overlap the inner surface of one end of the abutting sheet material 2 with the outer surface of the other and weld them together.

[0036] Furthermore, in this case, the bottom is formed in the shape of a round or square plate, and the peripheral walls of the bottom and the main body are overlapped and welded together using the method described above to form a vessel shape. [Explanation of Symbols]

[0037] 1 septum 2(2a,2b) Sheet material 3,3´ joint piece 4,4' Welding Sheet L1~L3,L´2 fold F Overlapping surface (welding surface)

Claims

1. An electrolytic plating diaphragm formed in a container shape by overlapping and welding the ends of sheet materials (2a) and (2b), and accommodating an anode electrode or a cathode electrode inside to isolate the two electrodes, wherein a joining piece (3) is provided that is bent inward from the outside to the overlapping ends of the sheet materials (2a) and (2b) and covers the outer end of said ends, and the joining piece (3) and the opposing overlapping surfaces of the ends of the sheet materials (2a) and (2b) are welded together integrally as a welding surface (F).

2. The electrolytic plating diaphragm according to claim 1, wherein a joining piece (3) is extended from the end of at least one sheet material (2a) that is to be overlapped, and the joining piece (3) is folded and formed so as to overlap the end of the other sheet material (2b).

3. The diaphragm for electrolytic plating according to claim 2, wherein the end of the other sheet material (2b) over which the joining piece (3) formed on one sheet material (2a) is placed is folded back along the folded inner surface of the joining piece (3) to form a joining piece (3') that is inserted, and the folded inner surfaces of the inserted joining piece (3') are made to be non-welded surfaces.

4. The electrolytic plating diaphragm according to claim 1, wherein the overlapping surfaces of the ends of the overlapping sheet materials (2a) and (2b) are made non-welded surfaces, a joining piece (3) made of a separate material from the sheet materials (2a) and (2b) is provided, which is folded so as to cover the outer ends and both the upper and lower surfaces of the overlapping ends, and the upper and lower surfaces of the ends of the sheet materials (2a) and (2b) and the inner surface of the joining piece (3) that overlaps with the upper and lower surfaces are each made welding surfaces (F) and are integrally welded together.

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