JP5146841B2 - Plating equipment - Google Patents

Description

  The present invention relates to a bus bar plating apparatus that imparts good electrical conductivity to an aluminum base material (bus bar) used in a large-capacity distribution line bus duct made of a long aluminum material, and also provides rust prevention.

In Patent Document 1, aluminum is a metal having a good balance of electrical conductivity, mechanical strength, mass and cost, but aluminum itself has a very strong electrochemical negative potential characteristic. It is disclosed that the chemical substitution of the metal on the surface is likely to occur, and that an oxide film is easily formed on the aluminum surface is a serious problem. For this reason, coated conductors have insufficient wettability with commonly used tin / lead solder alloys, especially in the case of aluminum substrates with a very small diameter (on the order of 0.1 mm). There was a problem that the adhesion state to the metal coating was worse, and the wettability of the base material was at a particularly low level. For this reason, the manufacturing method of the conductor disclosed in the cited document 1, a surface pretreatment, and a central core based on at least a part of aluminum covered with at least one metal layer by continuous electroplating. A method for continuously producing an electrical conductor, wherein the core is subjected to an electric current in an aqueous electrolytic cell containing KCN, CuCN, K ₂ CO ₃ and KNaC ₄ H ₄ O ₆ at a temperature of 20 ° C. to 60 ° C. A step of electrochemically copper plating at a strength of 1-10 A / dm ² , a step of rinsing at room temperature, and a tin substantially dissolved in methanesulfonic acid at a temperature of 20 ° C. to 60 ° C. Characterized in that it consists of a step of electrochemically tin-plating in an aqueous electrolytic cell containing an optional additive with an electric current strength of 1 to 100 A / dm ² and a step of rinsing at a water temperature of 60 ° C. Is .

  Patent Document 2 discloses an electroplating apparatus for plating a cylinder using air agitation. In the invention disclosed in Patent Document 2, the cylinder is provided with a cylindrical cylinder hole arranged in a V shape, and a pair of anode rods are inserted in parallel to the axial direction of the cylinder hole. An anode support base having a triangular cross section is projected on the jig base, and the anode rod is arranged eccentrically with respect to the center axis of the cylinder hole. Further, it is disclosed that a pipe for supplying air to the plating solution extends to the lower part of the jig lower base, and a plurality of holes for ejecting air are formed in the pipe.

  Patent Document 3 provides a plating solution processing unit that is convenient and space-efficient in that the plating solution purification process and temperature management are performed in the same system. This plating solution processing unit uses the plating solution in the plating tank. Disclosed is a pump that takes out and returns to the plating tank, a temperature adjusting means that adjusts the temperature of the plating solution taken out from the plating tank, and a purification processing means that purifies the plating solution.

  Patent Document 4 discloses a surface-treated aluminum plate that has high solder wettability and electrical conductivity and suppresses oxidation, discoloration, and whisker generation. In this surface-treated aluminum plate, a plating layer is formed by sequentially plating zinc, nickel, and tin on at least one surface of a member made of aluminum, and the surface of the plating layer is further immersed in a sodium phosphate solution. By spraying, a sodium phosphate solution is adhered to the entire surface of the plating layer, and after drying, an organic film made of an aqueous acrylic resin or the like is formed on the surface of the plating layer. This removes impurities on the surface of the tin layer, improves solder wettability and electrical conductivity, suppresses surface oxidation and discoloration, and further provides an organic film on the surface, thereby oxidizing and discoloring the surface. Can be prevented. Moreover, it discloses that a zinc layer is formed by performing zinc substitution plating with respect to an aluminum plate.

  Patent Document 5 discloses an aluminum electroplating method. In this method, as shown in FIG. 2 of Patent Document 5, mounting, alkaline cleaning solution, rinsing, acidic cleaning solution, rinsing, non-nitric acid strip, rinsing, zincate treatment, rinsing, alkaline Cu plating, rinsing, It consists of the steps of rinsing, dryer and removal.

Japanese translation of Japanese translation of PCT publication No. 8-511059 JP-A-9-87897 JP 2005-126780 A JP 2006-291340 A Special table 2007-523263

  In recent years, such as tenant buildings and factories, even if there is a bias in load depending on the location, the advantage of being able to balance the surplus location and the shortage location, the advantage of being excellent in fire resistance and earthquake resistance, electromagnetic waves The bus duct power main system is introduced because of the advantage that there is almost no generation, the advantage that it is easy to recycle, and the advantage that a power outlet can be freely selected. The bus duct is provided with a bus bar made of a plate or block-shaped aluminum base material as a conductor, and the bus bar needs to be plated in order to improve conductivity and keep rust.

  This bus bar plating process can be performed, for example, by the method disclosed in the above-mentioned patent document, but it is desired to automate the plating operation in order to improve workability. However, when plating a large object to be processed such as a bus bar, even if the system is increased in size using the conventional method, it is possible to impart uniform adhesion to a large area material such as a bus bar. Impossible.

  For this reason, this invention is providing the automated plating apparatus of the bus bar for providing favorable electroconductivity and rust prevention property to the bus-bar (bus bar) used for a bus duct.

The plating apparatus according to the present invention comprises a degreasing tank containing a degreasing solution for removing oil from the surface of the object to be processed, which is a plurality of aluminum bus bars, and a degreasing solvent from the object to be processed after the degreasing process. A first cleaning tank for removing, an etching tank for storing a strong alkali solution for removing oxides on the surface of the object to be processed, and a strong alkali solution for removing the object to be processed after etching A second cleaning tank; a nitric acid activation tank in which a nitric acid solution for activating the surface of the object to be treated is stored; and a third for removing the nitric acid solution from the activated object to be treated. A cleaning tank, a zinc plating tank containing a zinc replacement solution for electroless plating of zinc on the surface of the aluminum bus bar from which oxide has been removed, a fourth cleaning tank for cleaning the galvanized surface, and zinc Blue on the plated surface A bronze copper plating tank containing a copper plating solution for performing copper plating, a fifth cleaning tank for cleaning the copper-plated surface, and a surface of the object to be treated with copper plating, tin A tin plating tank containing a tin plating solution for plating, a post-treatment tank group for performing a post-treatment of the surface of the object to be plated, and a plating treatment in which the plurality of aluminum bus bars are installed. A plating apparatus constituted by moving means for sequentially immersing and moving the tool in each tank further includes the following requirements shown in paragraphs [ 0012 ] and [0013].

The third cleaning tank, the galvanizing tank, and the fourth cleaning tank are provided with a stirring mechanism, and an air stirring mechanism as the stirring mechanism is disposed along the tank below the tank. It is at least one pipe formed with an air outlet that inclines at a predetermined angle with respect to the vertical direction and jets air downward. By ejecting air downward at a predetermined angle, it is possible to form bubbles that rise evenly in the liquid in the tank, so that the liquid in the tank can be uniformly stirred (claim 1).

The liquid flow agitation mechanism as the agitation mechanism includes a plurality of jets that open the solution in the tank in the longitudinal direction of the tank, and a plurality of suction ports that are formed at positions facing the plurality of jets. And pipe pipes connecting the plurality of jet ports and the plurality of suction ports, and pump means provided on the pipes, each of the jet ports extending downward at a predetermined angle. A nozzle is provided. As a result, a flow along the object to be processed can be formed in the tank, so that the liquid in the tank can be efficiently stirred (claim 1) .

The third cleaning tank, the galvanizing tank, the fourth cleaning tank, and the tin plating tank are provided with temperature control means. For example, the liquid temperature is controlled to be 12 ° C. to 17 ° C. (Claim 2) .

Each of the second, third and fourth cleaning tanks is composed of an upstream tank and a downstream tank in which cleaning water moves in communication with each other, and the plurality of objects to be processed are installed. plating jig, is first immersed in the upstream side tank after being immersed in the downstream side tank, further when also pulled up from the upstream side tank, the wash water is intended to be sprayed (claim 3).

  According to the plating apparatus of the present invention, zinc plating, copper plating, and tin plating are applied to the surface of the bus duct bus bar made of aluminum, so that the copper plating adheres well to the aluminum surface. Therefore, good electrical conductivity by copper plating can be ensured, and further, a rust prevention effect and good electrical conductivity by tin plating can be secured.

In addition, before galvanizing, copper plating, and tin plating, cleaning is performed by immersing twice in cleaning water and spraying cleaning water, so that it is possible to prevent the pre-solution from being brought into each plating tank. since, by automated, a plurality of bus bars, in which it is possible to facilities sequentially galvanized, copper plating and tin plating. In particular, the third washing tank, the galvanizing tank, and the tin plating tank are provided with an air stirring mechanism and a liquid flow stirring mechanism. In the air stirring mechanism, the tank is formed by jetting air downward at a predetermined angle. Since bubbles can rise up evenly in the liquid inside, the liquid in the tank can be uniformly stirred. Further, in the liquid flow stirring mechanism, a flow along the non-processed body can be formed in the tank, so that the liquid in the tank can be efficiently stirred.

It is a schematic block diagram of the plating apparatus which concerns on this invention. It is a flowchart figure of the plating method which concerns on this invention. It is explanatory drawing which showed the water washing spray washing tank. It is explanatory drawing which showed the two-stage type countercurrent water washing tank. It is explanatory drawing which showed the air stirring mechanism which is one of the stirring means. (A), (b) is explanatory drawing which showed the liquid flow stirring mechanism which is one of the stirring means.

  TECHNICAL FIELD The present invention relates to a bus bar plating method and apparatus for imparting good electrical conductivity to an aluminum base material (bus bar) used for a large capacity distribution line bus duct made of a long aluminum material and for preventing rust. For this reason, the aluminum plate material is subjected to a treatment to remove and activate the surface oxide with strong alkali (caustic soda) and concentrated nitric acid, and the surface is subjected to electroless zinc plating which is chemical plating. Further, the copper plating is applied to the galvanized surface by electroplating. By this copper plating step, not only as a pre-treatment for electroplating in the subsequent step, but also good electrical conductivity can be maintained. Further, after copper plating, acid tin plating is performed by electroplating. As a result, not only the effect of rust prevention but also good current-carrying characteristics can be maintained.

  When automating galvanization, copper plating and tin plating on the above aluminum bus bar (hereinafter referred to as the object to be treated), it is important to make it uniform by controlling the liquid temperature and concentration, and the time and stirring of the galvanization process including pretreatment. Become.

  For this reason, in this invention, stirring including the liquid temperature before and behind a galvanization process and water washing is performed. About liquid temperature, temperature adjustment is performed so that liquid temperature may be in the range of 12 degreeC-17 degreeC. In addition, since the object to be processed has a plate-like shape, stirring is performed so that the cleaning and the plating process in each part are uniform.

  Further, the amount of aluminum dissolved in the zinc-substituting solution increases with time, but the concentration is controlled so as to be suppressed to a reference value, for example, 5 g / liter or less. This can be achieved by discharging a predetermined amount of zinc replacement liquid in the tank and adding a predetermined amount of new zinc replacement liquid when the reference value is exceeded or approached.

  In addition, it is important how nitrate ions contained in the activation liquid during the pretreatment process are not brought into the zinc replacement liquid. For this reason, it is necessary to sufficiently wash the object to be treated before the galvanizing process. For this reason, in this invention, it achieves by suppressing a nitrate ion density | concentration to 80 ppm or less in the stirring of water washing, and management of a water washing liquid.

  Further, after the object to be processed is activated, the surface of the object to be processed is in a state of being easily oxidized, so that the time for air movement is minimized (for example, 15 seconds or less). The moving speed is controlled to suppress oxidation of the surface of the object to be processed.

  Caustic soda and nitric acid are regularly updated. The renewal indication is preferably determined by the amount of aluminum processed or the working time.

The copper strike solution used for copper plating is controlled by pH control and free cyan concentration. Basically, the pH is controlled to be in the range of 9.8 to 10.5, and the free cyan density is controlled to be in the range of 1 to 3 g / liter. Further, in the copper strike solution, the zinc concentration brought from the previous plating step is always controlled to be 1 g / liter or less. In addition, the current density used for copper plating is also managed to be within a predetermined range (for example, 0.5 A / dm ^{2 to} 1.0 A / dm ² ).

  By managing the above various conditions, the object to be treated can be automatically plated with zinc, copper and tin, and a well-plated bus bar can be obtained in large quantities by automation.

The plating apparatus 100 according to the present invention is, for example, as shown in FIG. 1, and a plurality of tanks (2-12, 14-22) arranged linearly, and guides arranged along the tank on both sides of the tank. A rail 41, a plating jig 40 that moves along the guide rail 41, and a workpiece to be processed mounted on the plating jig 40 while moving the plating jig 40 along the guide rail 41 (see FIG. A driving mechanism 33 for moving A) shown in FIG. 5 up and down so as to be immersed in the liquid (washing water, plating solution, etc.) in the tank, and a temperature control mechanism for adjusting the temperature of the liquid stored in the tank 31, a stirring mechanism 32 for stirring the liquid contained in the tank, the drive mechanism 33, the temperature control mechanism 31, the stirring mechanism 32, and a control unit (C for controlling electric power used for electroplating) / U) With 30 Constructed.

  In the plating apparatus 100 of the present invention shown in FIG. 1, a plurality of long aluminum bus bars (objects to be processed) A are mounted on the plating jig 40 in the mounting space 1 and the intermediate mechanism 13 is interposed by the drive mechanism 33. Then, it moves to the immersion degreasing tank 2, where the immersion degreasing step 110 shown in the flowchart of FIG. 2 is executed.

  The immersion degreasing tank 2 contains an alkaline solution, and the object to be processed A is immersed therein to remove oil stains attached to the surface of the object to be processed A. And the to-be-processed object A pulled up from the immersion degreasing tank 2 moves to the washing spray tank 3. FIG.

  In the water washing spray tank 3, the first washing step 120 is executed. As shown in FIG. 3, the washing spray tank 3 is configured such that washing water 80 is accommodated in the tank 70, and includes a pipe portion 77 disposed along an edge 76 in the longitudinal direction, and the pipe portion 77. , And spray nozzles 75 provided at predetermined intervals. Accordingly, in the first cleaning step 120, the object to be processed A is immersed in the cleaning water 80 in the tank to eliminate the alkaline solution, and the cleaning water is supplied to the spray nozzle when the object to be processed A is pulled up. The object to be processed A is washed by spraying from 75.

  The object to be processed A cleaned in the water washing spray tank 3 moves to the alkali etching tank 4 and is immersed in a strong alkali solution (for example, caustic soda solution) accommodated in the alkali etching tank 4, and the surface of the object to be processed A The aluminum oxide is removed (alkali etching step 130).

  And the to-be-processed object A surface-treated moves to the continuous water-washing tank 5 and the water-washing spray tank 6 as the 2nd washing | cleaning process 140. FIG. The washing tank 5 and the washing spray tank 6 are a two-stage countercurrent washing method. For example, as shown in FIG. 4, this two-stage counter-flow flushing system is divided into two tanks, an upstream tank 82 and a downstream tank 81, by a partition wall 73 in the tank 70. The side tank 81 communicates with each other through a communication port 84 below the partition wall 73, and the wash water 83 flowing from the inflow pipe 74 disposed above the wall portion 71 of the upstream tank 82 is supplied to the upstream tank. 82 reaches the downstream tank 81 through the communication port 84, overflows from the upper part of the wall portion 72 of the downstream tank 81, and is treated as sewage. In addition, an injection nozzle 75 is provided on the upper portion of the partition wall 73 and the upper portion of the wall portion 71 of the upstream side tank 82 in the same manner as the above-described washing spray tank so as to inject cleaning water onto the object A to be pulled up. It is what has become. Reference numeral 50 denotes an air agitation unit that constitutes a part of the agitation mechanism 32.

  In the water washing tank 5 and the water washing spray tank 6 having the above-described configuration, the workpiece A whose surface has been subjected to the alkali etching treatment is immersed in the water washing tank 5, and then dipped in the water washing spray tank 6 and then spray-washed. (Second cleaning step 140). Thereby, the strong alkali root brought into the next nitric acid immersion tank 7 can be reduced to the limit.

  The to-be-processed object A cleaned in the second cleaning step 140 is immersed in the nitric acid immersion tank 7, and the surface is activated by nitric acid (nitric acid immersion step 150). After the activation of nitric acid, the object A is subjected to the same cleaning process in the water-washing tank 8 and the water-washing spray tank 9, which are the above-described two-stage countercurrent water washing system (third washing step 160). In the water washing tank 8 and the water washing spray tank 9, the temperature of the washing water is controlled by the temperature adjustment mechanism 31 and the stirring mechanism 32 in order to minimize the introduction of nitrate radicals into the next zinc replacement (electroless galvanizing) tank. Control and stir the wash water.

The stirring mechanism 32 includes, for example, an air stirring mechanism shown in FIG. 5 and a liquid flow stirring mechanism shown in FIGS. 6 (a) and 6 (b). In the air agitating mechanism 50, a plurality of air pipes 51 to which air is supplied are arranged below the tank 60 in parallel along the longitudinal direction of the tank 60, and from an air injection port 52 provided with the air pipe 51. By injecting the air B obliquely downward and outward, the liquid 61 that is cleaning water or a plating solution is agitated and a flow is formed in the direction indicated by C, for example. Is to contact uniformly.

6 (a) and 6 (b), the liquid agitating mechanism shown in FIGS. 6 (a) and 6 (b) sucks the liquid 61 in the tank 60 from the plurality of suction ports 65 through the operation of the pumps 63 and operates a plurality of blowers. The liquid is stirred by blowing out from the outlet 64 into the tank 60. The stirring device 32 is provided with a suction port 65 and a blower port 64 facing each other in the longitudinal direction so that a liquid flows along the workpiece A, and the blower port 64 is further provided at a predetermined angle. The nozzle 67 is provided at the tip of the nozzle 67 inclined downward. In the tanks 9, 10, and 11, the air stirring mechanism 50 and the liquid flow stirring mechanism are implemented.

The to-be-processed object A sufficiently cleaned in this manner is immersed in a zinc replacement solution accommodated in the galvanizing tank 10 to be galvanized (zinc replacement step 170). Further, the drive mechanism 33 is controlled so as to minimize the air exposure time from the nitric acid immersion tank 7 to the zinc replacement tank 10. Oxidation of the workpiece A is suppressed by setting the time to 15 seconds or less.

  And the to-be-processed object A after galvanizing is wash | cleaned closely in the water-washing tank 11 and the water-washing spray tank 12 which are a two-stage countercurrent water washing system similarly to having mentioned above.

In these zinc replacement step 170 and the third and fourth cleaning steps 160 and 180 before and after that, stirring including liquid temperature control and water washing is performed. For this reason, the water washing tank 8 or the water washing spray tank 9, the galvanizing tank 10, the water washing tank 11 or the water washing spray tank 12 is provided with a temperature control mechanism 31 and a stirring mechanism 32.

After the fourth cleaning step 180, the electrode is immersed in a copper strike solution accommodated in a copper plating (copper bronze plating) tank 14 through the intermediate mount 13, and a predetermined amount of electric power is applied to perform copper electroplating. (Copper plating step 190). For this copper strike solution, pH management and free cyan density management, as well as zinc density management and current density management are performed. In the pH control, the pH of the copper strike solution is in the range of 9.8 to 10.5. In the free cyan concentration management, the free cyan concentration is in the range of 1 to 3 g / liter. In the zinc concentration management, the zinc concentration is 1 g / liter. In the current density management, the current density is managed so as to be within the range of 0.5 A / dm ^{2 to} 1.0 A / dm ² .

  After the copper plating step 190, the object to be processed A is sent to the two-stage countercurrent water-washing water washing tank 15 and the water washing spray tank 16 to be washed (fifth washing step 200). And after washing | cleaning enough, it sends to the tin plating tank 17, is immersed in the tin plating solution accommodated in the tin plating tank 17, a predetermined electric power is given, and the electroplating of tin is given (tin plating process) 210). The tin plating tank 17 is provided with a temperature control mechanism 31 for controlling the temperature of the tin plating solution. Specifically, in the case of an alkaline tin plating solution (for example, containing sodium stannate, sodium hydroxide and sodium acetate, or containing potassium stannate, potassium hydroxide and potassium acetate), a temperature of 60 ° C. to 80 ° C. In the case of an acidic tin plating solution (for example, containing stannous sulfate and sulfuric acid), the temperature is controlled to be about 25 ° C.

  And the to-be-processed object A tin-plated is sent to the collection tank 18, and is immersed in the solution (it changes with the kind of tin plating solution) accommodated in the collection tank 18, and collect | recovers the tin plating solution which adhered (collection). Step 220). Then, it moves to the washing spray tank 19 as shown in FIG. 3 and is immersed in washing water, and at the time of pulling up, washing water is sprayed and sufficiently washed (sixth washing step 230). And the surface of the to-be-processed object A is neutralized with the solution accommodated in the neutralization tank 20 and accommodated in the neutralization tank 20 (neutralization process 240). This solution is determined according to the type of solution used in the tin plating step 210. And the last washing | cleaning is performed in the water-washing spray tank 21 (7th washing | cleaning process 250), the to-be-processed object A is finally hot-washed in the hot-water washing tank 22, and it returns to the work space 1 and completes an operation | work. .

  Through the above steps, a plurality of objects to be processed A can be attached to the plating jig 40, and each step can be performed automatically and sequentially, so that a larger amount of plating can be performed than in the prior art. It is.

DESCRIPTION OF SYMBOLS 1 Work space 2 Immersion degreasing tank 3, 6, 9, 12, 16, 19, 21 Flushing spray tank 4 Alkali etching tank 5, 8, 11, 15 Flushing tank 7 Nitric acid immersion tank 10 Zinc plating tank 13 Relay stand 14 Copper plating Tank 17 Tin plating tank 18 Recovery tank 20 Neutralization tank 22 Hot water washing tank 30 Control unit 31 Temperature control mechanism 32 Stirring mechanism 33 Drive mechanism 40 Plating jig 50 Air stirring mechanism 51 Air pipe 52 Air injection port 60 Tank 61 Liquid 63 Pump 64 Outlet 65 Suction port 66 Pipe 67 Nozzle 70 Tank 71, 72 Wall 73 Partition wall 74 Inflow pipe 75 Injection nozzle 76 Edge 77 Pipe 80 Washing water 81 Downstream tank 82 Upstream tank 83 Washing water 84 Communication port

Claims (3)

A degreasing tank containing a degreasing solution for removing oil from the surface of the object to be treated, which is a plurality of aluminum bus bars;
A first cleaning tank for removing a degreasing solvent from the object to be treated after degreasing;
An etching tank in which a strong alkaline solution for removing oxide on the surface of the object to be processed is stored;
A second cleaning tank for removing a strong alkaline solution from the object to be processed after etching;
A nitric acid activation tank containing a nitric acid solution for activating the surface of the object to be treated;
A third washing tank for removing the nitric acid solution from the object to be treated after activation;
A galvanizing tank in which a zinc replacement solution for performing electroless plating of zinc on the surface of the aluminum bus bar from which the oxide has been removed;
A fourth cleaning tank for cleaning the galvanized surface;
A copper-plating bath containing a copper-plating solution for performing copper-plating on the galvanized surface;
A fifth cleaning tank for cleaning the copper-plated surface;
A tin plating tank containing a tin plating solution for performing tin plating on the surface of the object to be copper plated;
A post-treatment tank group for performing a surface post-treatment of the object to be treated with tin plating;
In a plating apparatus constituted by moving means for moving the plating jig in which the plurality of aluminum bus bars are installed by sequentially immersing them in each tank ,
The third cleaning tank, the galvanizing tank and the fourth cleaning tank are provided with a stirring mechanism,
The stirring mechanism is arranged along the tank below the tank, and includes at least one pipe formed with an air outlet that inclines at a predetermined angle with respect to the vertical direction of the tank and jets air downward. An air agitating mechanism, a plurality of jets opening the solution in the tank in the longitudinal direction of the tank, a plurality of suction ports formed at positions facing the plurality of jets, and the plurality of jets And a plurality of suction ports, and a pump means provided on the pipe, each of the jet outlets having a nozzle extending downward at a predetermined angle. A plating apparatus characterized by comprising a mechanism. The third cleaning tank, the galvanizing bath, the fourth cleaning tank, and the tin plating bath, the plating apparatus according to claim 1, wherein the temperature control means is provided. Each of the second, third and fourth cleaning tanks is composed of an upstream tank and a downstream tank in which cleaning water moves in communication with each other, and the plurality of objects to be processed are installed. plating jig, is first immersed in the upstream side tank after being immersed in the downstream vessel, according to claim 1, further when being pulled from the upstream side tank, cleaning water, characterized in that it characterized in that it is sprayed The plating apparatus as described.

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