JP2014162927A - Electroplating apparatus and electroplating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroplating apparatus capable of more efficiently performing plating treatment to an object to be treated in a plating bath.SOLUTION: An electroplating apparatus 10 comprises: a plating bath 13 having a plating liquid A supplied; an anode 19 and cathode 17 provided in the plating bath 13; a pump 15 for sucking the plating liquid A in a tank 12; and a plating liquid supply pipe 18 for supplying the plating liquid A discharged from the pump 15 to the plating bath 13. The electroplating apparatus 10 applies voltage across the anode 19 and the cathode 17 to perform plating treatment to an object 20 to be treated in the plating bath 13. The outlet 18a of the plating liquid supply pipe 18 is directed downward.

Description

  The present invention relates to an electroplating apparatus and an electroplating method that use a mass-produced product as an object to be processed, and perform plating on the surface of many objects to be processed.

  Electroplating is a surface treatment technique in which a workpiece, that is, a workpiece, is immersed in a plating solution as a cathode, and a metal film is electrolytically deposited on the surface of the workpiece by direct current. In the case where a mass-produced product such as an electronic component is plated on a predetermined part as an object to be processed, conventionally, a barrel plating method is generally used to plate a large amount of an object to be processed by a single plating process. It has been broken. However, the barrel plating method has problems such that the object to be processed is entangled inside the barrel due to rotation of the barrel, the object to be processed is deformed, and the surface of the object to be processed is damaged. An electroplating apparatus and an electroplating method for coping with such problems have been proposed, and an example thereof is described in Patent Document 1.

  The electroplating apparatus described in Patent Document 1 includes a plating tank that accommodates an object to be processed, a partition wall provided at the bottom of the plating tank, and a liquid ejection hole provided in the partition wall. Further, the electroplating apparatus includes a liquid supply unit provided below the partition wall and a pump that supplies the plating solution in the plating solution tank to the liquid supply unit. The electroplating apparatus further includes a cathode and an anode provided inside the plating tank, a power supply unit connected to the cathode and the anode, and a control circuit for controlling the power supply unit and the pump.

  In the electroplating apparatus and the electroplating method described in Patent Document 1, the pump is driven in a state where an object to be processed is put in the plating tank, and the plating liquid passes through the liquid supply portion and the liquid ejection hole to the plating tank. It is ejected upward, and the power of the power supply unit is supplied to the electrodes. As a result, the object to be processed is agitated by the jet of the plating solution formed in the plating tank, and other objects to be processed are in electrical contact with the object to be processed that is in contact with the cathode. The surface of the object is plated. According to the electroplating apparatus and the electroplating method described in Patent Document 1, since the objects to be processed are agitated by the jet of the plating solution, it is possible to prevent the objects to be processed from being rubbed strongly, deformation of the objects to be processed, It is said that it can prevent scratches.

Japanese Patent Laid-Open No. 2002-30696

  However, in the electroplating apparatus and the electroplating method described in Patent Document 1, when supplying the plating solution from the liquid supply unit to the plating tank, the plating solution is ejected upward. That is, since the plating solution is ejected to the plating tank against the gravity, the flow rate of the plating solution is reduced, and the object to be processed cannot be sufficiently stirred. Therefore, when the flow rate of the plating solution is increased in order to sufficiently stir the object to be processed, the time for the object to be in contact with the cathode is shortened (insufficient contact) and the plating process becomes inefficient. Has occurred.

  An object of the present invention is to provide an electroplating apparatus and an electroplating method capable of achieving both sufficient time (contact point) for the workpiece to contact the cathode in the plating tank and sufficient stirring of the workpiece. It is to provide.

  The electroplating apparatus of the present invention includes a plating tank to which a plating solution is supplied, and an anode and a cathode provided in the plating tank, and a voltage is applied to the anode and the cathode so that the inside of the plating tank An electroplating apparatus that performs a plating process on the object to be processed is provided with a plating solution supply pipe having an outlet for supplying the plating solution to the plating tank facing downward.

  In the electroplating apparatus of the present invention, the plating tank has a cup shape surrounding a center line in the vertical direction, and the inner surface of the plating tank is tapered in a direction in which the inner diameter decreases as it approaches the bottom. Is curved.

  In the electroplating apparatus of the present invention, the center line of the plating solution supply pipe intersects the center line in the vertical direction in a side view of the plating tank.

  In the electroplating apparatus of the present invention, the cathode is provided by directly performing electroless plating on the inner surface of the plating tank to deposit a metal thin film.

  In the electroplating method of the present invention, a plating solution is supplied to a plating tank, a voltage is applied to an anode and a cathode provided in the plating tank, and an object to be processed in the plating tank is plated. In the method, the plating solution is supplied downward to the plating tank.

  The electroplating method of the present invention causes the plating solution to flow in a vortex shape in the plating tank in a plan view of the plating tank.

  In the electroplating method of the present invention, the voltage is applied to the anode and the cathode, the plating solution is supplied to the plating tank, and the voltage is applied to the anode and the cathode. The step of not supplying the plating solution to the plating tank is alternately performed.

  According to the present invention, the plating solution flows out from the plating solution supply pipe in the same direction as the direction in which gravity acts. For this reason, it can suppress that a plating solution flow rate falls, and to-be-processed object can fully be stirred. Therefore, the object to be processed easily comes into contact with the cathode, and the efficiency of the plating process is increased.

  According to the present invention, when the plating solution collides with the bottom of the plating tank, it flows outward in the radial direction of the circle centered on the center line by kinetic energy, and rises in an arc shape along the shape of the bottom. To do. Therefore, the workpiece is easily stirred by its own weight, and the workpiece can be prevented from staying near the bottom.

  According to the present invention, the plating solution flows spirally along the inner surface of the plating tank within a horizontal plane, and the object to be processed is easily stirred.

  According to the present invention, the workpiece is easily stirred by repeatedly supplying and stopping the plating solution.

It is the schematic diagram which looked at the electroplating apparatus of this invention from the side surface. (A) is side surface sectional drawing which shows the other example of arrangement | positioning of the plating solution supply pipe | tube in the electroplating apparatus of this invention, (B) is a top view of FIG. 2 (A). It is a schematic diagram which shows the whole electroplating apparatus of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. An electroplating apparatus 10 shown in FIG. 1 includes a tank 12 for storing a plating solution A in an interior 11, a plating tank receiver 36 provided in the interior 11 of the tank 12, and a plating tank 13 supported by the plating tank receiver 36. And a pump 15 for sucking the plating solution A in the tank 12 and supplying the sucked plating solution A to the plating chamber 14 of the plating tank 13. The plating tank 13 has a cylindrical portion 13a and a bottom portion 13b.

  The plating tank 13 can be placed on the plating tank receiver 36 or removed from the plating tank receiver 36. A discharge port 12 b is provided in the bottom 12 a of the tank 12, and the discharge port 12 b is connected to the suction port 15 a of the pump 15 through the flow path 16. A flow path 16 is connected to the discharge port 15 b of the pump 15. Further, a prime mover for driving the pump 15, for example, an electric motor 35 is provided.

  The plating tank 13 has a cup shape configured such that the outer diameter decreases as the plating tank receiver 36 is approached. The plating tank 13 is integrally formed of an insulating material such as resin, for example, polyethylene resin (PE). A plating chamber 14 is formed inside the plating tank 13, and the inner surface 13c of the cylindrical portion 13a has a cup shape curved downward. That is, the inner surface 13 c of the cylindrical portion 13 a is recessed in a tapered R shape within the longitudinal section of the plating tank 13. The taper is set in such a direction that the inner diameter of the inner surface 13 c becomes smaller as it is closer to the plating tank receiver 36.

  The inner surface 13c of the plating tank 13 is provided with a cathode (cathode) 17 as an electrode. The cathode 17 directly applies electroless plating to the inner surface 13 c on the bottom side of the plating tank 13 to deposit a metal such as nickel or copper as a thin film, and the bottom side of the plating tank 13 is used as the cathode 17.

  On the other hand, a plating solution supply pipe 18 is provided above the plating tank 13. The plating solution supply pipe 18 is provided vertically in the direction perpendicular to the center line B. The plating solution supply pipe 18 may be made of a metal material or a resin material. Further, the plating solution supply pipe 18 is movable in the vertical direction. An outlet 18 a provided at the lower end of the plating solution supply pipe 18 is disposed in the plating chamber 14 of the plating tank 13. The distance from the outlet 18a to the lowest part of the inner surface 13c is preferably about 200 mm. An inflow port 18 b provided at the upper end of the plating solution supply pipe 18 is connected to the discharge port 15 b of the pump 15 through the flow path 16.

  Further, an anode (anode) 19 as an electrode is attached to the plating solution supply pipe 18 at a position near the surface of the plating solution A. The anode 19 is immersed in the plating solution. The anode 19 is a soluble and insoluble electrode, and the anode 19 is made of nickel, tin, or copper. The anode 19 can be made of any metal material depending on the metal that is electrolytically deposited on the workpiece 20. Also in this case, the anode 19 is mainly made of nickel.

  The cathode 17 and the anode 19 are connected to a power supply unit 21, and a direct current flows from the power supply unit 21 to the plating solution A in the plating tank 13. Further, a control circuit 22 that controls the power supply unit 21 and the pump 15 is provided. Energization / non-energization of the electrodes is controlled by a signal output from the control circuit 22, and driving / stopping / rotational speed of the pump 15 is controlled.

  An electroplating method in which a metal film is electrolytically deposited on the surface of the workpiece 20 by the electroplating apparatus 10 to perform the plating process will be described. First, the lower end of the plating solution supply pipe 18 is disposed in the plating chamber 14 of the plating tank 13, and the workpiece 20 is put into the plating chamber 14. Further, the pump 15 is driven and the plating solution A inside the tank 12 is sucked by the pump 15. The plating solution discharged from the pump 15 passes through the flow path 16 and the plating solution supply pipe 18 and is ejected from the outlet 18 a of the plating solution supply pipe 18 to the plating chamber 14. That is, the plating solution A is ejected downward in the direction along the center line B.

  In addition, a voltage is applied from the power supply unit 21 to the cathode 17 and the anode 19. Here, the supply control of the plating solution A to the plating chamber 14 and the control to apply a voltage to the cathode 17 and the anode 19 may be performed simultaneously, or one of the controls is performed first, and the other is controlled. Control may be performed later.

  As a result, the workpiece 20 is agitated by the jet of the plating solution A formed in the plating chamber 14, and another workpiece 20 comes into contact with the workpiece 20 in contact with the cathode 17, and the other The workpiece 20 is in electrical contact with the cathode 17. In this way, the metal film is electrolytically deposited on the surface of the workpiece 20 and plated.

  In this way, by stirring the workpiece 20 by the jet of the plating solution A, it is possible to prevent the workpieces 20 from rubbing against each other strongly, and the elongated workpiece 20 or the workpiece 20 having no strength can be obtained. However, a high-quality plating film can be formed without causing scratches on the plating film. Further, in order to cause the plating solution A in the plating chamber 14 to flow, a plating film can be formed on the workpiece 20 even when the specific gravity of the workpiece 20 is close to the plating solution A.

  As described above, in the electroplating method using the electroplating apparatus 10 of the present embodiment, the plating solution A is sprayed downward into the plating chamber 14. That is, the plating solution A is ejected from the plating solution supply pipe 18 in the same direction as the direction in which gravity acts. For this reason, it can suppress that the flow rate of the plating liquid A falls, and the to-be-processed object 20 can fully be stirred in the plating chamber 14. FIG. Further, by providing the cathode 17 over the entire inner surface on the bottom side of the plating tank 13, a sufficient contact between the workpiece 20 and the cathode 17 can be secured. Therefore, the workpiece 20 can easily come into contact with the cathode 17 and the efficiency of the plating process is increased.

  Further, since the plating tank 13 is provided in the inside 11 of the tank 12, the plating solution A overflowing from the upper part of the plating tank 13 falls by its own weight and is stored in the inside 11 of the tank 12. Therefore, it is not necessary to provide a mechanism for collecting the plating solution A overflowing from the plating tank 13 and a pipe for returning the collected plating solution A to the tank 12.

  In addition, the inner surface 13 c of the plating tank 13 is recessed in a tapered R shape, and the plating solution A is ejected downward along the center line B of the plating tank 13. For this reason, when the jet of the plating solution A collides with the inner surface 13c on the bottom side of the plating tank 13, it flows outward in the radial direction of the circle centering on the center line B by kinetic energy, and the shape of the inner surface 13c. Ascending along the arc shape. Therefore, the workpiece 20 can be easily stirred by its own weight, and the workpiece 20 can be prevented from staying near the bottom of the plating tank 13, and the workpiece 20 can more easily come into contact with the cathode 17. Moreover, since the stirring efficiency with respect to the to-be-processed object 20 improves, the flow volume of the plating solution A ejected to the plating chamber 14 can be reduced as much as possible.

  The plating tank 13 of this embodiment is not a mesh-like structure such as a ridge or a ridge used in barrel plating or the like, and the inner surface 13c has a continuous R shape. That is, the hole penetrating the plating tank 13 in the thickness direction and the unevenness in the thickness direction are not provided. Therefore, the workpiece 20 can be efficiently stirred without being caught or clogged in the plating chamber 14. Furthermore, even if the plating solution A is supplied and the workpiece 20 is stirred, the depth of the plating bath 13 is determined so that the workpiece 20 does not come out of the plating bath 13.

  Next, another arrangement example of the plating solution supply pipe 18 used in the electroplating apparatus 10 of FIG. 1 will be described based on FIG. In FIG. 2A, elements other than the plating tank 13 and the plating solution supply pipe 18 are omitted. As shown in FIG. 2A, the screw 50 is provided in the vicinity of the outlet 18 a inside the plating solution supply pipe 18 in a side view of the plating tank 13. The screw 50 is fixed so as not to rotate and can be removed. A vortex is formed in the plating solution A supplied from the plating solution supply pipe 18 by the screw 50. In addition, normal agitation can be performed by removing the screw 50, or agitation in which a vortex is generated by attaching the screw 50 can be performed.

  FIG. 2B shows still another arrangement example of the plating solution supply pipe 18. In a plan view of the plating tank 13, the center line B and the center line of the plating solution supply pipe 18 are coaxial. In addition, the outlet 18a is provided at a position deviating from the center line B. In FIG. 2B, the plating solution A ejected from the plating solution supply pipe 18 is ejected in the tangential direction of a circle centering on the center line B and supplied to the plating tank 13.

  The plating solution A supplied to the plating tank 13 flows in a vortex in the plating chamber 14. Also, the plating solution A supplied to the plating tank 13 flows along the inner surface of the plating tank 13 in a horizontal plane as shown in FIG. 2B, and draws a vortex around the center line B. Flows along a trajectory. As a result, the workpiece 20 is pressed against the inner surface 13c on the bottom side of the plating tank 13 by centrifugal force due to the vortex flow of the plating solution A, and the workpiece 20 is likely to come into contact with the cathode 17.

  Another example of the electroplating method that can be executed in the various electroplating apparatuses 10 described above will be described. For example, a step of ejecting the plating solution A to the plating tank 13 while supplying power to the electrodes, and a step of not ejecting the plating solution A to the plating tank 13 while supplying power to the electrodes. Alternatively, an alternating electroplating method can be employed.

  Further, FIG. 3 shows equipment 51 used for an operation of transporting the plating tank 13, an operation of extracting (discharging) the plating solution A from the plating tank 13, an operation of replacing the plating tank 13, and the like. The equipment 51 includes a support 23. The support column 23 is provided so as to be movable in the horizontal direction along the rail 52. In addition, the equipment 51 has a slider 24 that can move along the height direction of the column 23, and a lifting platform 25 is attached to the slider 24.

  The elevator 25 is provided with an electric motor 26 for raising and lowering. The elevator 25 is raised and lowered in the height direction of the column 23 by controlling the rotation and stop of the electric motor 26 and controlling the rotation direction. . Further, the lifting platform 25 can be rotated around the rotation axis of the electric motor 26 in a vertical plane. The lift 25 can be rotated by the electric motor 26.

  Further, the lifting platform 25 is provided with a chuck mechanism 27. The chuck mechanism 27 includes a head 29 to which a pair of chucks 28 that grip the plating tank 13 are attached, and a cylinder 30 that opens and closes the pair of chucks 28. The head 29 is attached to the lifting platform 25 so that it cannot move in the vertical direction and can rotate within a horizontal plane. Further, by moving the plunger of the cylinder 30 back and forth, the pair of chucks 28 operate to hold and release the plating tank 13. The cylinder 30 may be either a hydraulic cylinder or a pneumatic cylinder.

  Further, a hollow rotating shaft 31 to which the head 29 is attached is provided. When the elevator 25 is rotated, the angle of the center line of the rotary shaft 31 with respect to the vertical line can be adjusted. The elevator 25 is provided with an electric motor 32 as a prime mover, and a power transmission mechanism 33 that transmits the power of the electric motor 32 to the rotary shaft 31. The power transmission mechanism 33 is a mechanism that transmits power between the rotary shaft 31 and the output shaft 34 of the electric motor 32. The power transmission mechanism 33 includes a combination of a sprocket and a chain, a combination of a pulley and a belt, and the like. It is used. The control circuit 22 controls the electric motors 26 and 32 and the cylinder 30 described above.

  Next, as an operation before performing the plating process as described above, an operation of transporting the plating tank 13 using the equipment 51 shown in FIG. 3 will be described. First, the cylinder 30 is controlled and the plating tank 13 is gripped by the pair of chucks 28. Further, the electric motor 26 is driven to adjust the height of the lifting platform 25, the plating tank 13 is moved to the inside 11 of the tank 12, and the plating tank 13 is installed on the plating tank receiver 36. Further, the chuck 28 is opened, the slider 24 is raised, and the chuck 28 is pulled away from the plating tank 13.

  The equipment 51 in FIG. 3 stops with the elevator 25 raised, and the chuck 28 is held above the plating tank 13 or the column 23 is moved on the rail 52 so that the plating tank 13 and the tank 12 are moved. The strut 23 stops at a place different from a certain place. Thereafter, the plating process described above can be performed.

  Furthermore, the operation | work which drains the plating liquid A from the inside of the plating tank 13 using the installation 51 of FIG. First, the plating solution supply pipe 18 is moved to the outside of the plating tank 13 in a state where the plating process is not performed and the plating tank 13 is placed in the tank 12. Next, the plating tank 13 is gripped by the chuck 28, the lifting platform 25 is raised, and the plating tank 13 is moved above the plating tank receiver 36. Then, the center line of the rotating shaft 31 is inclined with respect to the line along the vertical direction, and the plating tank 13 is rotated by the power of the electric motor 32. Then, the plating solution A in the plating chamber 14 overflows from the plating tank 13 due to centrifugal force and falls into the inside 11 of the tank 12.

  Thereafter, the plating tank 13 is placed on the plating tank receiver 36 and the chuck 28 is separated from the plating tank 13. Further, the lifting platform 25 is held above the plating tank 13 or moved to a place different from the place where the tank 12 is installed. Further, the plating solution supply pipe 18 is inserted into the plating tank 13, and the plating solution A is supplied from the plating solution supply pipe 18 into the plating tank 13. In this way, the work of replacing the plating solution A in the plating tank 13 is performed.

  Further, in the equipment 51 of FIG. 3, the plating tank 13 can be detached from the chuck 28 by controlling the cylinder 30 and operating the chuck 28 in a state where the plating process is not being executed. Therefore, an operator can carry the plating tank 13 separately from the tank 12. In addition, if the work to put the workpiece 20 into the plating tank 13 with the plating tank 13 removed from the chuck 28 and the work to take out the workpiece 20 after the plating process from the plating tank 13 are performed, these operations are performed. Can be easily performed.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the electroplating apparatus of the present invention includes a structure in which a plating tank is provided inside the tank and a structure in which the plating tank is provided above the tank. The prime mover that rotates the plating tank includes an electric motor and a hydraulic motor. Further, the electroplating apparatus of the present invention includes a structure in which a flow rate control valve for controlling the flow rate or flow rate of the plating solution is provided in the flow path from the pump to the plating solution supply pipe. Furthermore, the shape of the inner surface of the tank in the horizontal plane may be either circular or quadrangular. Furthermore, although the illustrated plating tank explains the example which is the taper R shape curved in the direction where the inner surface of a bottom part dents downward, this invention is flat in the inner surface of the bottom part of a plating tank. Including structures that are

DESCRIPTION OF SYMBOLS 10 Electroplating apparatus 13 Plating tank 13a Cylindrical part 13c Inner surface 17 Cathode 18 Plating liquid supply pipe 18a Outlet 19 Anode 20 To-be-processed object A Plating liquid B Centerline

Claims (7)

A plating tank to which a plating solution is supplied; and an anode and a cathode provided in the plating tank; and applying a voltage to the anode and the cathode to perform a plating process on an object to be processed in the plating tank. An electroplating device to be applied,
An electroplating apparatus provided with a plating solution supply pipe with an outlet for supplying the plating solution to the plating tank facing downward. The electroplating apparatus according to claim 1,
The plating tank has a cup shape surrounding a vertical center line,
The electroplating apparatus, wherein an inner surface of the plating tank is curved into an R shape having a taper in such a direction that the inner diameter becomes smaller as it approaches the bottom. The electroplating apparatus according to claim 2,
The electroplating apparatus, wherein a center line of the plating solution supply pipe intersects with the center line in the vertical direction in a side view of the plating tank. The electroplating apparatus according to claim 2,
The cathode is an electroplating apparatus in which an inner surface of the plating tank is directly subjected to electroless plating to deposit a metal thin film. An electroplating method of supplying a plating solution to a plating tank, applying a voltage to an anode and a cathode provided in the plating tank, and performing a plating process on an object to be processed in the plating tank,
An electroplating method in which the plating solution is supplied downward to the plating tank. The electroplating method according to claim 5,
An electroplating method in which the plating solution is swirled in the plating tank in a plan view of the plating tank. The electroplating method according to claim 5,
Supplying the plating solution to the plating tank while applying a voltage to the anode and the cathode;
In a state where voltage is applied to the anode and the cathode, the step of not supplying the plating solution to the plating tank;
This is an electroplating method that performs alternately.

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