JP2007169771A - Method for plating inner wall of thin tube and thin tube manufactured by the plating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of plating the inside wall of a narrow tube having a miniaturized diameter and a composite plating method with a dispersion of an insoluble ultrafine particle, an ultra dispersed diamond (UDD) or the like. <P>SOLUTION: A plated film on the inside surface of the narrow tube is formed by arranging an inlet opening part for a plating solution in the narrow tube to oppose to the flow direction of the plating solution and making the plating solution forcibly flow into the inside of the narrow tube to keep the concentration of the plating solution existed inside and that existed outside the narrow tube to be equal. As a result, a normal and uniform plated and composite-plated film is formed on the inside surface of the narrow tube. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to small diameter tubes (hereinafter referred to as thin tubes) used in the field of microfabrication technology aiming at light weight, small size, and high functionality, including electronic devices, and in particular, improvement of the functions of these thin tubes. The present invention relates to a method of plating on the inner wall of a thin tube for measuring.

  Recent electronic devices tend to be highly functional, small and light, and the technologies that support them include advances in microfabrication technology, electronic material technology, especially electrical connection technology as a device. Various connectors are often used as electrical contacts for connecting and disconnecting electronic devices as typical parts of the electrical connection technology. For example, various connector examples for printed circuit boards (see, for example, Non-Patent Document 1). ), And many examples of applications of spring connectors to cellular phones, AV equipment, video equipment, information equipment (see, for example, Non-Patent Document 2) and the like. These connectors are mainly used in pin-socket type pairs, and electrical connection is achieved by fitting rod-like pin portions into hollow pipe-like socket portions. Therefore, since the electronic device can be further reduced in size and weight by reducing the size and weight of the pin-socket type, it is desired that the pin and socket be reduced in size and weight. Further, in the pin-socket type, a pin having a diameter of 0.3 to 0.635 mm is also commercially available, but a smaller diameter is desired.

  In order to make a detachable contact on the connector used for electrical connection, it is desirable that the contact portion has excellent wear resistance and low contact electrical resistance, and precious metal plating such as gold, silver and copper is applied. Is done. However, pure metal is too soft and has poor wear resistance. Generally, high-melting-point nickel, tungsten, or oxide is alloyed or compounded with these metals to maintain wear resistance. For example, the contact surface of an electrical contact has a fluorine polymer compound compounded with gold on a nickel base metal to reduce wear resistance and electrical resistance and make it difficult to attach moisture and dirt. (For example, refer to Patent Document 1).

  In addition, in the pin-socket type connector with a small diameter, in particular, the socket type has a small diameter, so that the inner wall of the socket achieves excellent wear resistance and low contact electric resistance characteristics, so that gold, silver, copper In order to improve the wear resistance of such precious metal plating and these precious metals, it is desired to perform composite plating.

  On the other hand, regarding the plating method on the inner wall of the cylindrical member, a very long and heavy metal pipe (for example, refer to Patent Document 2), a small diameter and long tube (for example, refer to Patent Document 3), a curve of a feeler pipe. A tube (see, for example, Patent Document 4) and the like are disclosed. However, as long as the tube diameter permits, these plating methods for the inner wall of the cylindrical member are all provided with an anode inserted into the inner side of the cylindrical member or a plating solution chamber into which the anode is inserted, and the anode and the inner wall of the cylindrical member. Various measures are taken to prevent electrical contact with the (cathode). However, as the cylindrical member becomes smaller and more complicated, it becomes difficult to insert an anode inside the cylindrical member or to install a plating solution chamber in which the anode is inserted, and plating on the inner wall of the cylindrical member is difficult. It becomes difficult.

  Furthermore, the inner wall surface of the small-diameter cylindrical member is coated with a composite plating film made of a metal matrix in which insoluble ultrafine particles and UDD are at least uniformly dispersed, and the thin tube has wear resistance, corrosion resistance, hardness, heat resistance, lubricity, etc. It is desired to provide high functional properties.

“Fujitsu Component Product Catalog 2001-2005”, Fujitsu Component Limited, http: // www. fcl. fujitsu. com / products / connector / lineup / pbc. html, 2001-2005 " "Yokowo, Product Catalog, 2005, Yokowo Co., Ltd., http://www.yokowo.co.jp/product/electronic.html, 2005.11.18. Update date" “T. Takebe, T. Matsuzaki, N. K. Shrestha and T. Sagi, J. Sur. Finishing Soc. Jap., 54 610 (2003)”. Patent No. 3322211 JP 7-224396 A Japanese Patent Publication No.7-65233 Japanese Patent Laid-Open No. 10-306398 JP 2001-247998 A

  Regarding the plating method on the inner wall of the cylindrical member, particularly the inner wall of the thin tube, as the cylindrical member has a small diameter or a complicated shape, a method of inserting an anode into the inner side of the cylindrical member in the prior art or an anode has been inserted In the method of providing a plating solution chamber, it is difficult to insert an anode or install a plating solution chamber. Accordingly, the present invention provides a plating method for the inner wall of a straight tube having a small diameter or a complicated shape such as bending, branching or bending, and a composite plating method in which insoluble ultrafine particles, UDD and the like are at least uniformly dispersed.

Means and actions / effects for solving the problem

  In general, the principle of electroplating is to apply an electric current from an external power source between a metal to be plated (anode) and a metal to form a plating film (cathode), extract electrons from the anode metal, and use the metal as a metal ion as an electrolyte of the plating solution. Elute in solution. On the other hand, the eluted metal ions move in the electrolyte solution to the surface of the plating film forming metal which is the cathode of the counter electrode, and in contact with the surface, the metal ions receive electrons from the cathode and become metal to form the plating film forming metal surface. It is to precipitate.

  In a normal plating state, that is, in a state where the surface of the plating film forming metal is directly exposed to the plating solution without any interference, it is considered that there is only an electrolyte solution between the metal to be plated and the plating film forming metal. In general, the electrolyte solution is agitated by well-known agitation means such as a stirrer, ultrasonic vibration, bubbling, etc., but by these agitation means, the diffusion double layer on the surface of the plating film forming metal is destroyed and generated. Metal ions can be easily deposited on the surface of the metal film forming the plating film by preventing pH change caused by hydrogen gas or removing the generated hydrogen gas. As a result, the metal ion concentration in the vicinity of the plating film forming metal decreases instantaneously, but the dynamic viscosity of the plating solution is reduced by the stirring means, and electrophoresis and electrostatic attraction due to the potential difference between the anode and the cathode. As a result, the metal ions move and the metal ion concentration in the vicinity of the plating film forming metal returns to the original concentration, and normal plating is performed.

  However, in actuality, in the plating on the inner wall of the thin tube having a small diameter or complicated, between the metal to be plated and the metal for forming the plating film (hereinafter referred to as the inner wall of the thin tube) between these metals. Distance, position and arrangement relationship, electrolyte solution viscosity, presence / absence of insoluble ultrafine particles and UDD for composite plating, shape of plating film forming metal, especially size and shape of inner diameter of cylindrical member, e.g. There are problems such as small diameters such as tubes, bent tubes, branched tubes, and curved tubes, and complicated tube shapes.

  Due to these problems, in contrast to the instantaneous decrease in the metal ion concentration in the vicinity of the metal that forms the plating film, the inflow of the plating solution into the inner wall of the thin tube cannot be handled with ordinary stirring means, and the original metal ion concentration cannot be restored immediately. Normal plating becomes difficult.

  The inventors of the present invention have made diligent efforts in view of the solution of the above problems and have arrived at the following invention.

  A first aspect of the present invention is to form a plating film on the inner wall of the thin tube characterized in that the plating solution concentrations existing on the inside and outside of the thin tube are always kept equal during plating. is there. According to the present invention, normal and uniform plating and composite plating film can be formed on the inner wall of a thin tube.

  A second aspect of the present invention is to form a plating film on the inner wall of the thin tube characterized by forcibly flowing the plating solution inside the thin tube. The metal ion concentration in the plating solution inside the thin tube is instantaneously reduced by the deposition of metal on the inner wall of the thin tube when an electric current is applied from an external power source, but the plating solution concentration in the thin tube is immediately plated by the flow means according to the present invention. The original concentration immediately before the execution is restored. Further, hydrogen gas generated on the surface of the metal film on the inner surface of the thin tube is also quickly removed from the surface. The flow rate of the plating solution is at least 1 to 500 cm / min, preferably 2 to 300 cm / min. On the other hand, the flow rate of the composite plating solution containing insoluble ultrafine particles, UDD and the like is preferably 100 to 1000 cm / min, more preferably 300 to 800 cm as a preferable range in the state of precipitation of insoluble ultrafine particles and UDD on the inner surface of the thin tube. / Min. According to the present invention, normal and uniform plating and composite plating film can be formed on the inner wall of a thin tube.

  A third aspect of the present invention is to form a composite plating film on the inner wall of the thin tube, wherein the plating solution is a composite plating solution containing metal ions, insoluble ultrafine particles, UDD, and the like. As is well known, dispersion of insoluble ultrafine particles and UDD in the plating solution is to maintain a uniform suspension state of the plating solution, and disperse particles such as insoluble ultrafine particles and UDD to form a plating film metal. To maintain a normal deposition state of the metal matrix, such as the following dispersion methods: propeller and stirrer method, composite plating solution circulation method, plate pump method, super The sonic dispersion method is well known. According to the present invention, a normal and uniform composite plating film can be formed on the inner wall of a thin tube.

  The use of insoluble ultrafine particles, UDD, etc. as composite plating has excellent functions such as high hardness, lubricity, flexibility, mold release, wear resistance, heat resistance, heat dissipation, corrosion resistance, decorativeness, etc. This is to expect the characteristics. Depending on the functional characteristics, insoluble ultrafine particles include oxides such as alumina, zinc dioxide, silica, zirconia, titania and ceria, carbides such as silicon carbide, titanium carbide and tungsten carbide, and nitrides such as silicon nitride and boron nitride. , Inorganic compounds such as molybdenum disulfide, borides, titanium compounds, powders of organic polymers such as fluororesin, nylon, polyethylene, metals, carbon, diamond, UDD, resins, etc., and at least two or more of these substances However, it is not limited to these.

    In general, insoluble ultrafine particles and UDD do not dissolve in the plating solution. Therefore, in order to perform composite plating that is sufficiently satisfied on the inner wall of the thin tube, the size of the insoluble ultrafine particles and UDD is uniform and the particle size is uniform. It is important to control the dispersibility in the plating solution, the surface properties of the plating film, the inner diameter of the thin tube, etc., and the diameter of the insoluble ultrafine particles or UDD is at least 5 depending on the high-functional properties. It is desired that the thickness is ˜500 nm, more preferably 10 to 100 nm, and that it is sufficiently dispersed in the plating solution during plating. If it is 5 nm or less, it is close to the lower limit of the nanoparticles obtained by the current technology, and enormous costs and energy are required to obtain it industrially, and if it is 500 nm or more, the surface properties and adhesion of the composite plating film are difficult. . Moreover, in order to fully disperse | distribute, as long as it does not have a bad influence at the time of metal plating, it is good to use generally known surfactant. Examples include, but are not limited to, Esocard (manufactured by Lion), Leocore (manufactured by Lion), Lionol (manufactured by Lion), polyoxyethylene lauryl ether (manufactured by Toshin Oil Chemical Co., Ltd.), and the like.

  According to a fourth aspect of the present invention, the thin tube is a thin tube selected from at least a small-diameter straight tube, a bent tube, a branched tube, a curved tube, or a complex tube having a complicated shape, and plating the inner wall of the thin tube It is characterized by. Incidentally, in the prior art, it is difficult to insert an anode inside a narrow tube such as a small diameter straight tube, a bent tube, a branched tube, a curved tube, or a complex tube having a complicated shape, or to provide a plating solution chamber into which an anode is inserted. However, according to the present invention, it is possible to perform plating on the inner walls of these thin tubes, and it is possible to perform normal and uniform plating and formation of a composite plating film on the inner walls of the thin tubes.

  According to a fifth aspect of the present invention, the outer wall surface of the thin tube is covered with a non-conductive seal member, and the plating film is formed on the inner wall of the thin tube by electrically opening only the inside of the thin tube. . By covering the outer wall surface of the thin tube with a non-conductive sealing member, a cathodic property appears only on the inner wall surface of the thin tube when a current is applied from an external power source between the metal to be plated and the inner wall of the thin tube. Insoluble ultrafine particles and UDD can be efficiently deposited on the inner wall surface of the thin tube, so that normal and uniform plating and composite plating film can be formed. The non-conductive sealing member referred to in the present invention is a commercially available electrically insulating tape, compound, paint, etc., for example, vinyl chloride resin, vinyl acetate resin, polyethylene, polystyrene, adhesive Teflon resin, silicon resin. However, it is not limited to these. The number of the thin tubes may be one or plural.

  According to a sixth aspect of the present invention, only the inside of each of a thin tube or a plurality of thin tubes whose outer wall surface is coated with a non-conductive seal member is used as a cathode, and a counter electrode for the cathode is a part other than the thin tube in the plating tank (for example, However, the present invention is not limited to this, but is preferably limited to the portion of the thin tube or the bundle of thin tubes that is disposed opposite to the plating solution inlet opening surface. A plating film is formed. By covering the outer wall surface of the thin tube with a non-conductive sealing member, the coated surface is electrically closed, and conversely, the entire inner wall of the thin tube is electrically opened. That is, when a thin tube or thin tube bundle covering the outer wall is immersed in a plating solution in this way, metal ions can be deposited on the inner wall surface of each thin tube under the application of current from an external power source. A plating film can be formed.

  According to a seventh aspect of the present invention, at least a plurality of thin tubes are bundled and the inlet opening surface of each thin tube of the thin tube bundle is directed in the same plane direction, or the inlet opening of the thin tube bundle and the plating solution for each thin tube A plating film is formed on the inner wall of each of the thin tubes by, for example, disposing the inlet opening of the metal plate so as to face the flow direction of the plating solution. By arranging all the plating solution inlet openings in each thin tube of the thin tube bundle to face at least the flow direction of the plating solution, the plating solution flows into each thin tube with the minimum resistance. A plating film can be formed.

  According to an eighth aspect of the present invention, a non-conductive seal member is used to insert a bundle of thin tubes into a non-conductive tube and prevent the plating solution from entering the gap between the thin tube outer wall and the non-conductive tube and between the thin tube outer walls. A plating film is formed on the inner wall of each thin tube by sealing with. The present invention is particularly effective when the plating is performed on a large number of thin tubes having a small diameter and a long length, and the length is substantially uniform. However, the present invention is not limited to these thin tubes. Furthermore, in the present invention, there is no infiltration of the plating solution into the gaps between the thin tubes and the thin tube bundle and the non-conductive tube, and there is no adhesion due to the plating between the thin tubes, and normal plating and composite plating can be performed. The non-conductive tube referred to in the present invention is an electrically insulating tube that is generally commercially available and may or may not be flexible. For example, vinyl chloride resin, vinyl acetate resin, polystyrene, polyester, silicon resin However, it is not limited to these.

  According to a ninth aspect of the present invention, the plating solution inlet of the non-conductive tube into which the thin tube bundle is inserted is flared to facilitate the inflow of the plating solution into the thin tubes, and the plating film on the inner walls of the thin tubes. It is characterized by forming. By widening the plating solution inlet in a flared shape, the plating solution can be easily and efficiently flown into each of the capillaries, and normal and uniform plating and formation of a composite plating film can be performed.

  According to a tenth aspect of the present invention, in at least one or a plurality of thin tube bundles, the outer wall of the end portion of the thin tube is covered with a non-conductive seal member, and the pipe is tightly sealed with a vacuum seal member at the other end portion. A conductive seal member is immersed in a plating solution, and a plating film is formed on the inner wall of each thin tube by circulating or circulating the plating solution inside each thin tube by suction or extrusion with a circulation pump. It is. In addition, if the said pipe is a flexible pressure-resistant member (for example, rubber | gum, silicon rubber, etc.), it can substitute for the said vacuum seal member. As is apparent from the disclosure of the fourth aspect of the present invention, the outer wall of the end of the narrow tube covered with the non-conductive sealing member is the inner wall of the narrow tube under application of current from an external power source between the metal to be plated and the inner wall of the thin tube. Thus, the cathode property appears only on the surface of the thin tube, so that the metal ions are efficiently deposited on the inner wall surface of the thin tube so that a normal and uniform plating film can be formed. On the other hand, the seal with the vacuum seal member prevents the so-called vacuum leakage when sucking or extruding the plating solution, and allows the plating solution to circulate and circulate normally only inside each of the thin tubes. Can be formed. Furthermore, in the case of a composite plating solution containing insoluble ultrafine particles or UDD, normal and uniform composite can be obtained by circulating and circulating the composite plating solution inside each capillary while stirring with a well-known stirring means. A plating film can be formed.

  The eleventh aspect of the present invention is characterized in that the plating film is formed on the inner wall of the thin tube by swinging the thin tube itself in the plating solution. In the case of single plating (or single plating), the plating solution existing inside the narrow tube also swings due to the swinging of the narrow tube itself, and flows into and out of the narrow tube and flows outside the narrow tube. Therefore, the plating solution concentration inside and outside the narrow tube is kept equal, and a normal and uniform plating film can be formed.

  The inflow and outflow of the plating solution into and out of the narrow tube due to the swinging of the narrow tube can be understood by considering as follows. That is, in a stationary plating solution and a narrow tube open at both ends, if only the narrow tube is moved momentarily, the plating solution inside the narrow tube will remain stationary due to the law of inertia, and as a result, The plating solution inside the thin tube moves relatively. Furthermore, it is desirable that the moving (swinging) speed be larger than the viscosity of the plating solution, the frictional resistance between the inner wall of the thin tube and the plating solution, and the like.

    On the other hand, in the case of a composite plating solution containing insoluble ultrafine particles and UDD, normal composite plating can be efficiently performed by swinging the capillary tube while stirring the plating solution itself with a well-known stirring means. It can be carried out. Moreover, the said thin tube may be one or multiple.

  In a twelfth aspect of the present invention, the inlet opening of the thin tube bundle and the flow direction of the plating solution are disposed opposite to each other, and the opposed arrangement surface of the thin tube bundle with respect to the flow direction of the plating solution is at least rotated, oscillated and vibrated. The plating film is formed on the inner wall of each thin tube by giving any one of the above movements or a combination of these movements to the thin tube bundle. In the case of single plating, the plating solution that has entered the inside of the thin tube due to rotation, oscillation, vibration motion, etc. of the thin tube itself also causes rotation, oscillation, vibration motion, etc., and the plating solution outside the capillary tube is also stirred. As a result, the plating solution concentration inside and outside the narrow tube is kept equal, and a normal and uniform plating film can be formed. On the other hand, in the case of a composite plating solution containing insoluble ultrafine particles or UDD, the thin tube itself can be efficiently rotated by rotating, swinging or vibrating while stirring the plating solution itself with a well-known stirring means. Normal and uniform composite plating can be performed. Moreover, the said thin tube may be one or multiple.

    A thirteenth aspect of the present invention is characterized in that a plating film is formed on the inner wall of a thin tube by immersing at least one or a plurality of thin tubes in a plating solution and stirring the immersed thin tube with a stirring member serving as a cathode. To do. When the submerged capillary tube is stirred by the stirring member, the plating solution in the plating tank and the plating solution that has entered the inside of the capillary tube by capillary action or vibration motion due to stirring flow at the same time. In the case of single plating, the plating solution penetrating into the inside of the capillary tube by the capillary phenomenon or the vibration motion by stirring is also stirred by the stirring of the capillary tube itself, and the plating solution existing inside and outside of the capillary tube is agitated. The plating solution concentration inside and outside the narrow tube is kept equal, and a normal and uniform plating film can be formed. On the other hand, in the case of a composite plating solution containing insoluble ultrafine particles and UDD, the fine tube itself is stirred while stirring the plating solution itself, and a normal and uniform composite plating film can be efficiently formed. . Moreover, the said thin tube may be one or multiple.

The invention's effect

  Providing a plating method and a composite plating method that can form a normal and uniform film on the inner wall of the capillary tube by forcibly keeping the same plating solution concentration on the inside and outside of the capillary tube at all times during plating. did it.

  When plating on the inner wall of thin tubes with small diameters or complicated shapes, it is normal and uniform without inserting an anode inside the thin tube or installing a plating solution chamber with the anode inserted, which was difficult with conventional technology. A plating method for forming a thin film on the inner wall of the thin tube could be provided.

  Furthermore, the inner wall surface of the thin tube is coated with a composite plating film made of a metal matrix in which insoluble ultrafine particles and UDD are uniformly dispersed, and the thin tube inner wall has high functions such as wear resistance, corrosion resistance, hardness, heat resistance, and lubricity. A composite plating method that imparts properties can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a first embodiment in which the plating on the inner wall of the thin tube and the composite plating are normally and uniformly plated and combined by forcibly maintaining the same concentration of the plating solution existing inside and outside the thin tube. It is explanatory drawing of forming a plating film.

  According to FIG. 1, since the thin tube outer wall 1-1 is covered with a non-conductive sealing member 1-2, only the thin tube inner wall 1-3 becomes negative by applying current from the external power supply 1-4, It can be seen that the metal 1-5 to be plated is plated in the state of being anodized.

  During plating, that is, when a current is applied from the external power source 1-4 between the metal 1-5 to be plated and the thin tube inner wall 1-3, metal ions (cations) 1- near the surface of the thin tube inner wall 1-3 are formed. 6a precipitates on the surface of the thin tube inner wall 1-3. In this case, if the plating solution is a composite plating solution containing insoluble ultrafine particles and UDD1-7a, the insoluble ultrafine particles and UDD1-7a are also deposited on the surface of the inner wall 1-3 of the thin tube simultaneously with the metal ions 1-6a. become. In particular, in the case of a composite plating solution, the inlet opening surface of the narrow tube is disposed opposite to the flow direction 1-8 of the composite plating solution, and the composite plating solution is forced to flow toward the inlet opening surface of the thin tube. It is possible to perform composite plating that is more preferably caused to flow in by vibration, swinging, rotational movement, or the like.

  On the other hand, the concentration of the metal ions 1-6a in the vicinity of the surface of the thin tube inner wall 1-3 is instantaneously reduced by the deposition of the metal ions 1-6a on the surface of the thin tube inner wall 1-3. Immediately restore the original concentration. That is, when a current is applied from the external power source 1-4, metal ions 1-6b are eluted from the metal 1-5 to be plated into the plating solution, and the plating solution flows, swings, and vibrates at least in the direction of the arrow 1-8. Since the movement (flow) is performed by performing one or a plurality of movements such as rotation (the movement means is omitted in FIG. 1), the inlet opening surface of the narrow tube is arranged to face the movement movement direction. The plating solution passes through the inside of the thin tube most smoothly. Therefore, the instantaneous decrease in the metal ion 1-6a concentration in the vicinity of the surface of the narrow tube inner wall 1-3 is immediately eliminated and restored to the original plating solution concentration. In the case of composite plating, insoluble ultrafine particles and UDD are excessively added to the plating solution, and even if they are deposited on the surface of the inner wall 1-3 of the thin tube, there is little effect on changes in the concentration of insoluble ultrafine particles and UDD. It is.

  Here, although the clear mechanism in which an insoluble ultrafine particle and UDD precipitate with a metal ion on the said cathode inner wall surface of a cathode is unknown, it is considered as follows. That is, in general, inside a solid, electrons, atoms, ions, molecules, etc. interact with various chemical bonds (eg, ionic bonds, coordination bonds, covalent bonds, metal bonds, hydrogen bonds, van der Waals bonds, etc.). The electric balance is maintained by the power of the and is almost neutral. On the other hand, on the solid surface, the continuity of various bonds is broken and ions such as cations and anions, radicals, etc. are formed and chemically active, that is, the chemical composition of the solid surface itself, the bonding state, the electron energy state, Changes in acid, basicity, polarity, etc. have occurred. Furthermore, the ratio of the active site showing the change in these states to the whole solid (if the solid has a large particle size, the influence of the change site has a negligible effect on the whole solid) is As the solid becomes fine particles, it appears significantly more prominently. When such solid insoluble ultrafine particles or UDD are dispersed in a plating solution that is an aqueous electrolyte solution, the ionic component of the electrolyte, the ionic component of water (hydrogen ion, hydroxyl ion, etc.) or the adsorption of the fine particles on the active surface Thus, a diffusion electric double layer is formed, and insoluble ultrafine particles and UDD are slightly less electrically neutral. Therefore, it is considered that metal ions for plating are also adsorbed and deposited on the inner wall of the capillary tube by electrophoresis or electrostatically.

  FIG. 2 shows a second embodiment in which the plating solution concentration inside or outside of the narrow tube or the composite plating solution concentration is made uniform by flowing the plating solution inside the narrow tube, and the plating or composite plating film on the inner wall of the thin tube It is explanatory drawing that formation of can be performed normally and uniformly.

  According to FIG. 2, the thin tube 2 is covered with a non-conductive sealing member 2-2 and the thin tube inner wall 2-3 is electrically opened, and the thin tube 2 is inclined and immersed in the plating solution 2-4. It can be seen that the forced flow direction 2-6 of the plating solution by the stirring means 2-5 and the plating solution inlet opening 2-7 of the thin tube 2 are disposed opposite to each other. In the state of this opposing arrangement, the plating solution can be forced to flow through the narrow tube by the stirring means 2-5, and the plating solution can be efficiently passed through the thin tube. By passing the plating solution, the hydrogen gas generated on the surface of the narrow tube inner wall 2-3 can be easily removed, and a normal and uniform plating film can be formed. Further, when the plating solution is a composite plating solution, it is preferable to use the stirring means 2-8 together in order to obtain insoluble ultrafine particles and UDD uniform dispersibility in the plating solution in a preferable form. Further, the inclination of the narrow tube 2 is effective in removing hydrogen gas generated from the inner surface of the thin tube. Furthermore, the inclination of the thin tube 2 is 0 to 90 degrees, preferably 20 to 60 degrees, more preferably 30 to 45 degrees. These inclination angles can be selected in relation to the stirring means 2-5 and 2-8. For example, when the particle size of insoluble ultrafine particles or UDD is large or the concentration is high, it is necessary to increase the forced flow rate in the stirring means if the inclination of the thin tube 2 is increased. On the other hand, when the particle size of insoluble ultrafine particles or UDD is small or the concentration is low, the forced flow rate in the stirring means may be slowed down.

  FIG. 3 shows a third embodiment in which a plurality of thin tubes are bundled, the plating solution inlet openings of the thin tubes are aligned on the same surface, and the thin tube bundle is inserted into a non-conductive tube. , Prevention of invasion of the plating solution into the gap between the outer wall of the end of the thin tube (plating solution inlet) and the non-conductive tube and the outer walls of the ends of each thin tube, and the outer wall of the other end of the thin tube (the plating solution) Plating or composite plating on the inner wall of each thin tube by sealing with a non-conductive sealing member to prevent the plating solution from entering the gap between the outer wall of the outlet) and the non-conductive tube and the outer wall of each other end of each thin tube It is explanatory drawing that can be performed normally.

  Furthermore, the plating solution inlet opening of each thin tube is disposed opposite to the flow direction of the plating solution, and the end of the non-conductive tube is flared to efficiently flow the plating solution into the inside of each thin tube. As a result, the plating on the inner wall of each thin tube and the formation of the composite plating film can be performed normally and uniformly. In addition, it is preferable to take out the lead wire which electrically connected each said thin tube outside, and to prevent permeation of the plating solution from the take-out part of this lead wire.

  According to FIG. 3a, in order to bring the plating solution into contact with only the inner wall of each thin tube, the thin tube bundle 3a has a non-conductive tube 3a-2 with the plating solution inlet opening 3a-1 of each thin tube aligned on the same surface. It can be seen that it has been inserted. Furthermore, the plating solution enters the gap between the outer wall 3a-3 at the end of the thin tube and the non-conductive tube 3a-2 and the outer walls at the ends of the thin tubes at the plating solution inlet opening 3a-1 of each thin tube. And prevention of invasion of the plating solution into the gap between the outer wall 3a-5 of the other end of the thin tube and the non-conductive tube 3a-2 and the outer walls of the other end of each thin tube at the outlet 3a-4 of the plating solution Therefore, it can be seen that the non-conductive sealing member 3a-6 is sealed. Although not shown, the inside of the non-conductive tube 3a-2 in which the thin tube bundle 3a in such a state is inserted is in a sealed state. Means are provided for normal pressure. Furthermore, the opening 3a-1 is disposed opposite to the forced flow direction 3a-7 of the plating solution, and the end 3a-8 of the nonconductive tube is expanded in a flare shape.

3b and 3c show cross sections of the inlet opening (AA ′) and the intermediate portion (BB ′) of the thin tube bundle of FIG. 3a, respectively.
In FIG. 3b, it can be seen that the thin tubes 3b are in contact with each other and the gap between the non-conductive tube 3b-1 and each thin tube is sealed with a non-conductive seal member 3b-2. Accordingly, since the plating solution no longer enters from the sealed portion, the plating solution penetrates and flows only inside each narrow tube, and a plating film can be formed on the inner wall surface of each narrow tube.

  In FIG. 3c, it can be seen that the thin tubes are in contact with each other, but there is no non-conductive sealing member. That is, the lead wires 3a-13 for plating the inner walls of all the thin tubes at the same time can be taken out only by electrically contacting the thin tubes 3c.

  Further, the end portion of the non-conductive tube into which the plating solution flows is widened in a flared shape so that the plating solution can sufficiently flow inside the narrow tube. Accordingly, the plating solution can be easily and efficiently flown into each of the thin tubes, and the plating on the inner wall of each thin tube and the formation of the composite plating film can be performed normally and uniformly.

  FIG. 4 shows a fourth embodiment in which the plating film is normally and uniformly formed on the inner wall of the thin tube by applying the flow of the plating solution only to the inside of the thin tube or the bundle of thin tubes by suction or extrusion circulation. It is explanatory drawing of being able to do.

  According to FIG. 4a, in the portion where the thin tube 4a or the thin tube bundle (not shown in the figure and described as a single thin tube) is immersed in the plating solution 4a-1, the outer wall of the end of the thin tube is non-conductive sealing member 4a. It can be seen that the plating solution 4a-1 contacts only the inner wall 4a-3 of the thin tube by covering with -2.

  Next, the plating solution 4a-1 flows through the inside of the thin tube by sucking or extruding and circulating the plating solution 4a-1 with the circulation pump 4a-4. Under such a steady forced flow, when a current is applied between the metal 4a-6 plated by the external power source 4a-5 and the inner wall 4a-3 of the thin tube, the metal of the metal 4a-6 to be plated Is eluted into the plating solution and becomes metal ions, which are deposited on the surface of the inner wall 4a-3 of the thin tube. Therefore, the instantaneous decrease of the metal ion concentration existing inside the narrow tube due to the deposition of metal ions on the inner wall of the thin tube is immediately returned to the original plating solution concentration by the forced flow of the plating solution, and the normal and uniform plating and composite plating film Formation can be performed. Although FIG. 4a illustrates the tubule in a vertical state, it can have any tilt angle.

  In the case of composite plating, it is preferable to stir the insoluble ultrafine particles and UDD with the well-known stirring means 4a-8 in order to maintain a uniform dispersion state in the plating tank 4a-7. Furthermore, it is preferable that the plating solution and the composite plating solution are plated in advance by applying current with the external power source 4a-5 after the circulation flow of suction or extrusion reaches a constant speed by the circulation pump 4a-4.

  Furthermore, although FIG. 4a illustrated the case of a single capillary, in the case of a plurality of tubes, it is preferable to use the universal auxiliary means 4b-1 illustrated in FIG. 4b, but is not limited thereto. By using the universal auxiliary means 4b-1, normal and uniform plating or composite plating film can be formed according to the shape of the thin tube.

  FIG. 4b shows an example of a case where a plurality of typical thin tubes are collectively sucked or extruded and circulated inside the thin tubes. This is an example of a branching thin tube 4b-2, a curved thin tube 4b-3, a cylindrical straight thin tube bundle 4b-4, a rectangular straight thin tube 4b-5, or the like. These thin tubes are immersed in the plating solution 4b-6 through non-conductive seal members 4b-21, 4b-31, 4b-41, 4b-51 as illustrated in FIG. 4b. On the other hand, each of the thin tubes exemplified above and the universal auxiliary means 4b-1 are pipes 4b-22, 4b-32, 4b-42, 4b-52 and vacuum seal members 4b-23, 4b-33, 4b-43, 4b. Connect via -53. Furthermore, the flow rate of the plating solution flowing inside each exemplary thin tube can be controlled by adjusting the cocks 4b-24, 4b-34, 4b-44, 4b-54 according to the shape of each thin tube.

  FIG. 5 shows a fifth embodiment, in which at least a plurality of thin tubes are immersed in a plating solution, and the immersed thin tube is stirred by a stirring member serving as a cathode, thereby forming a plating film on the inner wall of the thin tube. It is explanatory drawing of being able to do.

  According to FIG. 5, it can be seen that if a taper is provided at the bottom 5-2 of the plating tank 5-1, the thin tube 5 naturally gathers at the bottom 5-2 when the tube 5 is not stirred. When stirring is performed by the stirring means 5-3, the narrow tube 5 is stirred together with the plating solution 5-4 while repeating contact and non-contact with the stirring means 5-3 and the thin tubes. Therefore, the plating solution repeats inflow into the inside of the capillary tube 5 and discharge to the outside due to capillary action or vibration motion by stirring. In the above stirring state, when a current is applied by the external power source 5-5 so that the stirring means 5-3 is a cathode and the metal 5-6 to be plated is an anode, a thin tube (the outer wall is a non-conductive sealing member or the like) In this case, metal ions in the plating solution existing inside and outside (not sealed) are deposited on the inner and outer wall surfaces of the thin tube, and the concentration of metal ions in the vicinity of the inner and outer walls of the thin tube decreases instantaneously. However, the concentration of the plating solution on the outside of the capillary tube immediately returns to the original concentration by stirring, and the concentration of the plating solution on the inside of the capillary tube returns to the original plating solution concentration by capillarity or vibration motion by stirring. By the above repetitive motion and action, the plating film can be formed normally and uniformly on the inner surface of the thin tube.

  FIG. 6 shows a sixth embodiment in which an inlet opening of a bundle of thin tubes composed of at least one thin tube and a flow direction of the plating solution are arranged opposite to each other, and the flow of the plating solution flows on the opposite arrangement surface. FIG. 4 is an explanatory view showing that a plating film can be formed on the inner wall of each thin tube by imparting at least one of rotation, swing, vibration motion, etc., or a combination of these to the direction, to the thin tube bundle. is there.

    According to FIG. 6, a thin tube covered with a non-conductive sealing member as illustrated in FIG. 2 or a thin tube bundle 6 as illustrated in FIG. 3A is connected to and held by the cathode 6-2 with a hook 6-1. (Electrical connection between each thin tube inner wall and the hook is omitted), and suspended in the plating solution 6-3. The cathode 6-2 is held by a cathode holding means 6-4, and a current is applied by an external power source 6-6 between the inner walls of the thin tubes of the thin tube bundle 6 and the metal 6-5 to be plated. The movement of the plating solution inside each thin tube is also controlled by controlling the forward / reverse rotation, swing and vibration of the thin tube bundle 6 by computer control (not shown) of the shape and movement of the cathode 6-2 and the cathode holding means 6-4. In addition, the plating film can be formed normally and uniformly on the inner surface of the thin tube. If the plating solution is a composite plating solution containing insoluble ultrafine particles or UDD, the insoluble ultrafine particles or UDD can be sufficiently maintained with a stirring means 6-7 or the like that is well known. Preferably, normal and uniform composite plating can be performed by maintaining sufficient uniform dispersibility in the stirring means 6-7 and the like.

The present invention will be described in detail in the following examples, but the present invention is not limited to these examples.
(Experiment 1)
First, after coating the outer wall of the end of a copper capillary having an inner diameter of 2 mm, an outer diameter of 3 mm, and a length of 100 mm with an insulating tape, the inner wall was pretreated and subjected to electroplating. For pretreatment, the mixed powder of 10g sodium carbonate, 5g sodium metaphosphate and 5g sodium diphosphate is moistened with water and entangled with cotton yarn, polishing the inner wall of the copper thin tube, water washing, 10% hydrochloric acid treatment and water washing in order I went there.

Next, electroplating was performed with the experimental apparatus schematically shown in FIG. 4a in a state where the inner wall of the copper thin tube after the pretreatment was wet with the washing water. The plating solution is a normal Watt solution consisting of 240 g / L of nickel sulfate, 45 g / L of nickel chloride, and 30 g / L of boric acid, and components such as nickel hydroxide 03 g / L as a pH adjuster are prepared with distilled water. did. The electroplating conditions were pH 4.25, plating bath temperature 52-54 ° C., current density 2 A / dm ² , plating time 60 min, plating solution flow rate 200 cm / min, positive electrode nickel plate. The plating solution was flowed only by a circulation pump.

  As a comparative example, a copper thin tube having a length of 120 mm was used, and an area having a length of 110 mm was covered with an insulating tape on the outer wall. A lead wire serving as a cathode was connected to the remaining 10 mm copper thin tube range (the copper surface was exposed). The copper thin tube thus made is immersed vertically in the plating solution, and adjusted so that the plating solution has a height of 100 mm inside the copper thin tube (equivalent plating lengths in the example and the comparative example). The electroplating was performed under the same conditions as in Example 1 except that the plating solution itself was allowed to stand without stirring to stop the flow of the solution.

  After the completion of plating, the inner wall of the copper thin tube was washed with water and dried, the copper thin tube was cut vertically, and the inner wall surface was observed with a microscope. As a result of comparing and examining the example and the comparative example, the example exhibited a clean nickel metal color, but the comparative example exhibited a slight nickel metal color at the lower end of the thin tube, but the overall was uneven and thin. A metallic color of nickel was exhibited.

(Experiment 2)
Electroplating was performed under exactly the same conditions as in Example 1 except that a copper thin tube having an inner diameter of 4 mm, an outer diameter of 5 mm, and a length of 100 mm was used.

  In the comparative example, plating was performed under exactly the same conditions as the comparative example in Example 1 except that a copper thin tube having an inner diameter of 4 mm, an outer diameter of 5 mm, and a length of 120 mm was used.

  After the completion of plating, the inner wall of the copper thin tube was washed with water and dried, the copper thin tube was cut vertically, and the inner wall surface was observed with a microscope. As a result of comparing and examining the example and the comparative example, the example exhibited a clean nickel metal color, but the comparative example exhibited a slight nickel metal color at the lower end of the thin tube, but the overall was uneven and thin. A metallic color of nickel was exhibited.

(Experiment 3)
Verification of the formation of a nickel matrix composite plating film containing UDD on the inner wall surface of the thin tube was performed by the microscope observation method in Example 1. This verification is based on the fact that when UDD of about 10 vol% or more is contained, the composite plating film no longer exhibits a nickel metal color, but rather becomes black (see, for example, Non-Patent Document 3). ). Therefore, Experiment 3 was performed by forming a nickel / UDD composite plating film containing a large amount of UDD.
As a comparative example, since the experiment in Example 1 is impossible, the comparative example was not performed. This is because if the stirring of the plating solution is stopped, the uniform dispersion of UDD is different from that of the example.

  First, after coating the outer wall of the end of a copper capillary having an inner diameter of 2 mm, an outer diameter of 3 mm, and a length of 100 mm with an insulating tape, the inner wall was pretreated and subjected to electroplating. For pretreatment, the mixed powder of 10g sodium carbonate, 5g sodium metaphosphate and 5g sodium diphosphate is moistened with water and entangled with cotton yarn, polishing the inner wall of the copper thin tube, water washing, 10% hydrochloric acid treatment and water washing in order I went there.

Next, electroplating was performed with the experimental apparatus schematically shown in FIG. 4a in a state where the inner wall of the copper thin tube after the pretreatment was wet with the washing water. The plating solution is a normal Watt solution consisting of nickel sulfate 300 g / L, nickel chloride 60 g / L, boric acid 40 g / L, and further AZTAB (see, for example, Patent Document 5) 7 g / L, UDD 10 g / L, etc. Was added to the Watt solution, and hydrochloric acid as a pH adjusting agent was added with distilled water, followed by dispersion with an ultrasonic disperser for 10 minutes. The electroplating conditions were pH 1.0, plating bath temperature 52-54 ° C., current density 3 A / dm ² , plating time 30 min, plating solution flow rate 300.
cm / min, positive electrode nickel plate.
The plating solution was flowed through the inside of the copper thin tube with a circulation pump, and further stirred with stirring means 4a-8 shown in FIG. 4a so that UDD was uniformly dispersed.

  After the completion of plating, the inner wall of the copper thin tube was washed with water and dried, the copper thin tube was cut vertically, and the inner wall surface was observed with a microscope. In the examples, a clean black composite nickel plating color was exhibited.

(Experiment 4)
Plating was performed under exactly the same conditions as in Example 3 except that a copper thin tube having an inner diameter of 4 mm, an outer diameter of 5 mm, and a length of 100 mm was used.

  After the completion of plating, the inner wall of the copper thin tube was washed with water and dried, the copper thin tube was cut vertically, and the inner wall surface was observed with a microscope. In the examples, a clean black composite nickel plating color was exhibited.

(Experiment 5)
First, a plurality of copper capillaries having an inner diameter of 0.14 mm, an outer diameter of 0.4 mm, and a length of 7 mm were pretreated and subjected to electroplating. For pre-treatment, (1) copper tubules were treated with an alkaline degreasing agent of Ascreen 850 (Okuno Pharmaceutical Co., Ltd.) at 80 ° C for 1 min, washed with water, and (2) Top Sun (Okuno Pharmaceutical Co., Ltd.). The inner and outer surfaces of the copper thin tube were activated, washed with water, and (3) Top Nicolon TOM (Okuno Pharmaceutical Co., Ltd.) was subjected to the electroless nickel-phosphorus strike plating, water washing, and the above treatments in sequence.

Next, electroplating was performed with the experimental apparatus schematically shown in FIG. 5 in a state where the inner wall of the copper thin tube after the pretreatment was wet with washing water. The plating solution is a gold plating solution comprising 14.6 g / L of potassium potassium cyanide, 14 g / L of tripotassium citrate, and 36 g / L of anhydrous citric acid. The pH adjuster is 20% phosphoric acid, 20%. Components such as potassium hydroxide were prepared with distilled water. In addition, an appropriate amount of cobalt sulfate is added as a catalyst for gold coloration. The electroplating experimental conditions were pH 3.8, plating bath temperature 40 ° C., current density 0.5 A / dm ² , plating time 30 min, plating solution rotation speed 50 rpm, positive electrode titanium / platinum.
In addition, plating was performed while simultaneously stirring the copper thin tube and the plating solution while bringing the copper thin tube into contact with the stirring means serving as a cathode.

  As a comparative example, plating was performed under the same conditions as in Example 5 except that the flow of the plating solution inside and outside the copper thin tube was stopped without stirring the copper thin tube and the plating solution with the stirring means. However, all the copper thin tubes were brought into contact with the stirring means, which was a cathode, so that electricity could be supplied.

  After the completion of plating, the inner wall of the copper thin tube was washed with water and dried, the copper thin tube was cut vertically, and the inner wall surface was observed with a microscope. As a result of comparing and examining the example and the comparative example, in the example, a beautiful gold metal color was exhibited, but in the comparative example, a slight gold metal color was exhibited at both ends of the thin tube, and the gold color was increased toward the middle portion of the thin tube. Became thin and had a thin gold metal color with unevenness as a whole.

Illustration of forced equalization of plating solution concentration inside and outside of thin tube Plating method on inner wall by forcibly flowing plating solution inside narrow tube Method of plating on inner wall by flowing plating solution inside each thin tube bundle a) Thin tube bundle b) A-A 'cross section c) B-B' cross section Method of plating on inner wall by suction or pressure flow of plating solution to inside of narrow tube a) Image of suction or pressure flow b Universal auxiliary means Plating method on the inner wall of a thin tube by stirring a plurality of thin tubes with a stirring means as a cathode in the plating solution Plating method on the inner wall by vibrating the thin tube itself in the plating solution

Explanation of symbols

2, 3b, 3c, 4a, 5: thin tube 3a, 6: thin tube bundle 1-1, 2-1: thin tube outer wall 1-2, 2-2, 3a-6, 3b-2, 4a-2, 4b-21 4b-31, 4b-41, 4b-51: non-conductive seal members 1-3, 2-3, 4a-3: inner walls of thin tubes 1-4, 2-9, 3a-11, 4a-5, 5- 5, 6-6: External power supply 1-5, 2-10, 3a-10, 4a-6, 5-6, 6-5: Metal to be plated 1-6a: Metal in the vicinity of the inner wall of the thin tube 1-7a: Insoluble Ultra fine particles and UDD
1-8, 1-9, 2-6, 2-13, 3a-7, 3a-9: Forced flow direction 1-10a: Metal deposited on the inner wall surface of the capillary tube 1-11a: Insoluble deposited on the inner wall surface of the capillary tube Ultra fine particles and UDD
1-12, 2-12, 3a-12, 4a-11, 4b-7, 5-7, 6-7: plating solution horizontal plane 2-5, 2-8, 4a-8, 5-3, 6-8 : Stirring means 2-7, 3a-1: Narrow tube inlet opening 2-11, 4a-7, 5-1: Plating tank 3a-2, 3b-1, 3c-1: Non-conductive tube 3a-3: Outer wall 3a-4 at end of thin tube: Outlet 3a-5: Outer wall 3a-8 at other end of thin tube: End 3a-13 of non-conductive tube: Lead wires 4a-1, 4b-6, 5-4, 6-3: Plating solutions 4a-4, 4b-8: Circulation pumps 4a-9, 4b-22, 4b-32, 4b-42, 4b-52: Pipes 4a-10, 4b-23, 4b-33, 4b -43, 4b-53: Vacuum seal member 4b-1: Universal auxiliary means 4b-2: Branched capillary 4b-3: Curved capillary 4b-4 Cylindrical straight tube bundle 4b-5: Square straight tubes 4b-24, 4b-34, 4b-44, 4b-54: Cock 5-2: Plating bath bottom 6-1: Hook 6-2: Cathode 6 4: Cathode holding means

Claims (17)

  A plating film is formed on the inner wall of the thin tube, and the plating film is formed on the inner wall of the thin tube by forcibly maintaining the same concentration of the plating solution existing inside and outside the thin tube. Plating method for the inner wall of thin tube.   The plating film is formed on the inner wall of the thin tube by forming a plating film on the inner wall of the thin tube by forcibly flowing a plating solution inside the thin tube. Method.   3. The method for plating a thin tube inner wall according to claim 1, wherein the plating solution is a composite plating solution containing metal ions and insoluble ultrafine particles.   3. The method of plating on the inner wall of a thin tube according to claim 1, wherein the plating solution is a composite plating solution containing nanodiamonds (described as ultra-dispersed tiremond; UDD).   5. The thin tube inner wall according to claim 1, wherein the thin tube is a tube selected from at least a small diameter straight tube, a bent tube, a branch tube, a curved tube, a complex tube having a complicated shape, and the like. Plating method.   A plating film is formed on the inner wall of the thin tube, wherein the outer wall surface of the thin tube is covered with a non-conductive seal member, and the plating film is formed on the inner wall of the thin tube by electrically opening only the inside of the thin tube. The method for plating on the inner wall of a thin tube according to claim 1.   In the formation of a plating film on the inner wall of a thin tube, the outer wall of the thin tube is covered with a non-conductive seal member, or only the inside of each thin tube bundled with a plurality of tubes is used as a cathode, and the plating solution is applied to a portion other than the thin tube. 7. The method for plating on the inner wall of a thin tube according to claim 1, wherein a plating film is formed on the inner wall of each thin tube by immersing a metal to be plated into an anode.   A plating film is formed on the inner wall of a thin tube, and a plurality of the thin tubes are bundled, and the inlet opening of each thin tube of the thin tube bundle (hereinafter sometimes referred to as a thin tube bundle) is directed in the same plane direction. 8. The method for plating a thin tube inner wall according to claim 1, wherein a plating film is formed on each thin tube inner wall by flowing a plating solution inside each of the thin tubes.   A plating film is formed on the inner wall of the thin tube, and the plating film is formed on the inner wall of each thin tube by disposing the inlet opening of the bundle of thin tubes and the plating solution inlet of each thin tube opposite to the flow direction of the plating solution. The method for plating on the inner wall of a thin tube according to any one of claims 1 to 8.   A plating film is formed on the inner wall of a thin tube, and the bundle of thin tubes is inserted into a non-conductive tube to prevent plating solution from entering the gap between the outer wall of the thin tube and the non-conductive tube and between the outer walls of the thin tube and plating. 10. The method for plating a thin tube inner wall according to claim 1, wherein a plating film is formed on each of the thin tube inner walls by sealing with a non-conductive sealing member that prevents contact between the liquid and the thin tube outer wall.   The plating film is formed on the inner wall of the thin tube, and the plating solution inlet of the non-conductive tube into which the bundle of thin tubes is inserted is flared to facilitate the inflow of the plating solution into each of the thin tubes. 11. The method for plating on the inner wall of a thin tube according to claim 1, wherein a plating film is formed on the inner wall of each thin tube.   A plating film is formed on the inner wall of a thin tube, and at least one or more thin tube ends are covered with a non-conductive seal member, and the other end is closely attached with a pipe with a vacuum seal member. 2. A plating film is formed on the inner wall of each thin tube by immersing the sealing member portion in the plating solution and circulating and circulating the plating solution inside each thin tube by suction or extrusion with a circulation pump. The plating method to the thin tube inner wall of thru | or 11.   13. A plating film is formed on the inner wall of the thin tube, and the plating film is formed on each inner wall of the thin tube by swinging the thin tube itself in a plating bath. Plating method.   For forming a plating film on the inner wall of a thin tube, the movement of at least one of rotation, oscillation, vibration, or a combination thereof is performed on the surface where the inlet opening of the bundle of thin tubes and the flow direction of the plating solution are opposed to each other. 14. The method for plating on the inner wall of a thin tube according to claim 1, wherein a plating film is formed on the inner wall of the thin tube by giving the tube bundle.   Formation of a plating film on the inner wall of a thin tube by immersing at least one or more of the thin tubes in a plating solution and stirring the immersed thin tube with a stirring member serving as a cathode The method for plating on the inner wall of a thin tube according to claim 1, wherein:   A capillary manufactured by a plating method on the inner wall of a capillary according to any one of claims 1 to 15.   A method for producing a thin tube plated by a method for plating an inner wall of a thin tube according to any one of claims 1 to 15.

Images