JP4743193B2 - Plating method - Google Patents

Description

  The present invention relates to a plating method for forming, for example, a terminal electrode of a chip component. More specifically, the present invention forms a uniform plating film on a large number of objects to be plated at a time without causing defective plating. In addition, the present invention relates to a plating method having excellent production efficiency.

  In the conventional barrel plating method, the smaller the object to be plated, the more objects to be plated that are plated incompletely. Further, the inner wall of the drum may be provided with unevenness for effectively stirring the object to be plated, and the object to be plated may enter the unevenness. In addition, since the object to be plated is scraped up by the inner wall of the rotating drum, it may be assumed that an excessive external force is applied to the object to be plated.

  Then, the plating method shown in the following patent document 1 is proposed as a plating method which can reduce the malfunction which generate | occur | produces in a to-be-plated object effectively. According to this plating method, air bubbles do not remain around the object to be plated arranged in the barrel, and problems such as incomplete plating caused by it can be solved.

However, in this method, when the syringe is moved upward with respect to the pod, the object to be plated in the pod rises into the plating solution and does not come into contact with the cathode electrode, so that plating cannot be performed. For this reason, the plating process is only performed when the syringe is moved downward with respect to the pod, and there has been a demand for shortening the plating process time, that is, improving the efficiency.
JP 2007-56359 A

  The present invention has been made in view of such a situation, and an object thereof is to form a uniform plating film on a large amount of an object to be plated at a time without causing defective plating, and to improve production efficiency. It is to provide an excellent plating method.

In order to achieve the above object, the plating method according to the present invention comprises:
A syringe that is movably arranged with respect to a pod containing an object to be plated immersed in a plating solution stored inside the plating tank is moved downward with respect to the pod, and inside the syringe, A first plating step for creating a flow of a plating solution in a downward direction inside the pod and performing a plating process on the object to be plated;
The syringe is moved upward with respect to the pod, and a plating solution is supplied from a plating solution supply passage formed inside the syringe to create a flow of the plating solution downward in the pod. And a second plating step for performing a plating process on the object to be plated,
In the second plating step, the object to be plated is plated while vibrating the pod.

  In the plating method according to the present invention, when the syringe is moved upward with respect to the pod, the plating solution is supplied from the plating solution supply passage formed in the syringe toward the pod. Therefore, it becomes possible to create a downward plating solution flow inside the pod, which suppresses the rising of the object to be plated that occurs when the syringe is moved upward with respect to the pod. Electrode conduction is ensured and plating becomes possible.

  In the second plating step, since the pod is vibrated, the object to be plated inside the pod is plated while being appropriately stirred. Therefore, in the method of the present invention, the plating process is performed not only in the first plating process but also in the second plating process, so that the plating process time can be shortened, and the plating film thickness is increased in a predetermined time. Production efficiency is improved.

  Moreover, in both the first plating step and the second plating step, a downward plating solution flow is formed inside the pod, and a fresh plating solution is always present around the object to be plated during the plating process. Supplied. Therefore, the ion concentration required for the plating process does not decrease around the object to be plated. As a result, the quality of the plating film is improved and the plating efficiency is also improved.

  In particular, in the first plating step, the downward flow of the plating solution generated when the syringe is moved downward with respect to the pod is strong, and the objects to be plated in the pod are pressed against each other by the flow of the plating solution. The energization efficiency between the plated objects is improved. In this respect, the plating efficiency is improved.

  For the above reasons, in the method of the present invention, a uniform plating film can be formed on a large amount of objects to be plated at a time without causing defective plating.

  In the plating method of the present invention, before the first plating step, the plating solution supply passage is closed, and the syringe is moved upward with respect to the pod. It is preferable to further have a bubble removing step of sucking up the bubbles existing inside the pod.

  At the upper and lower ends of the pod, the object to be plated is not allowed to flow out of the pod, and a mesh is installed to circulate the plating solution. According to the method of the invention, bubbles can be removed. Therefore, it is possible to effectively prevent floating of the plated product due to air bubbles and the fact that the air bubble adhering portion is not plated.

  The bubble removing step is not necessarily performed before the first plating step, but is preferably performed intermittently after the first plating step and the second plating step are alternately performed a plurality of times. For example, it is preferably performed once every 5 to 10 minutes.

Preferably, a cathode electrode is disposed so as to be in contact with an object to be plated accommodated in the pod, and the anode electrode is in contact with the plating solution accommodated in the plating tank,
In the first plating step and the second plating step, a voltage is applied between the anode electrode and the cathode electrode,
In the bubble removal step, no voltage is applied between the anode electrode and the cathode electrode. In this case, it is possible to prevent the plating film from being formed on the cathode electrode and maintain a preferable contact state with the object to be plated.

  Preferably, in the first plating step, the plating solution supply passage is closed and the syringe is moved downward with respect to the pod. By closing the plating solution supply passage and moving the syringe downward with respect to the pod, a downward flow of the plating solution with respect to the pod is formed. In this case, since the plating solution in the syringe descends together with the syringe, a downward flow with a uniform distribution in the cross section can be formed in the pod, and the object to be plated is distributed evenly and has good conduction. Obtainable.

  In the present invention, the upward direction does not need to completely coincide with the upward direction in the vertical direction, and may be inclined if there is a vector in the upward direction. Further, the downward direction does not need to completely coincide with the downward direction in the vertical direction, and is intended to be inclined if there is a downward vector.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is an overall schematic view of a plating apparatus according to an embodiment of the present invention.
2 is an exploded perspective view of the pod shown in FIG.
3 to 8 are schematic views showing the movement of the plating apparatus shown in FIG.
Plating equipment

  As shown in FIG. 1, a plating apparatus 2 according to an embodiment of the present invention has a plating tank 4. A partition wall 4a is formed inside the plating tank 4, and the inside of the plating tank 4 causes the tank body 4b in which the plating solution 6 is stored and the plating solution 6 overflowing from the tank body 4b to flow outside. It is divided into an overflow channel 4c. A plating solution supply port 4d is formed at the bottom of the tank body 4b, from which the plating solution is supplied to the inside of the tank body 4b to keep the inside of the tank body 4b at an ion concentration necessary for the plating process. It is.

  Inside the tank body 4b, a lower end portion of the syringe 8 is disposed so as to be movable in the vertical direction. In order to move the syringe 8 in the vertical direction, the syringe holding member 10 may be driven in the vertical direction by an actuator or the like. An accommodation space 8 a is formed inside the lower end portion of the syringe 8. The lower end of the accommodation space 8a is open to the inside of the tank body 4b.

  A supply passage 8b is formed in the upper inside of the syringe 8 along the longitudinal direction thereof. The supply passage 8b communicates with the accommodation space 8a, but has a smaller channel cross-sectional area than the accommodation space 8a. A tapered portion 8c is formed at the boundary between the accommodation space 8a and the supply passage 8b, and the cross section of the flow path is gradually narrowed from the accommodation space 8a toward the supply passage 8b. This is for realizing a smooth flow of the plating solution.

  A supply pipe 8d is connected to the supply passage 8b. A valve 12 and a pump 14 are attached to the supply pipe 8d, and a plating solution is supplied from a supply tank (not shown) toward the supply passage 8b. It is possible. The valve 12 is a control valve controlled by a control signal, for example, and can ensure and block communication between the supply passage 8b and the supply tank.

  Note that, depending on the type of the pump 14, it can also serve as a valve, and the valve 12 is not necessarily required. That is, when the pump 14 is driven, the plating solution is supplied from the supply tank toward the supply passage 8b, and if the drive of the pump 14 is stopped, the communication between the supply passage 8b and the supply tank is automatically cut off. It may be.

  In the accommodation space 8a, the pod 20 is disposed so as to be relatively movable along the longitudinal direction of the accommodation space 8a. As shown in FIG. 2, the pod 20 includes a cylindrical main body 22, meshes 23 and 24 attached to both ends of the main body 22 in the axial direction, and the meshes 23 and 24 can be attached to and detached from the main body 22. And attachment rings 25 and 26 to be attached. It is preferable that at least the outer surfaces of the main body 20, the meshes 23 and 24, and the attachment rings 25 and 26 are made of an insulating member.

  A cathode electrode 30 is attached to the center of the mesh 24 attached to the lower end opening of the main body 22, and the head 30 a is positioned inside the main body 22 with respect to the mesh 24. The cathode electrode 30 is composed of a conductive member, and the head 30a has the surface of the conductive member exposed. Outside the mesh 24 (outside the main body 22), the outer periphery of the cathode electrode 30 is covered with an insulating holding cylinder 34.

  The holding cylinder 34 is integrated with the mounting ring 26 by a plurality of rod-like connecting members (not shown) arranged at substantially equal intervals in the circumferential direction of the inner opening 26 a of the mounting ring 26. A mesh 24 is stretched around the inner opening 26 a of the attachment ring 26, and a mesh 23 is stretched around the inner opening 25 a of the attachment ring 25. Therefore, as shown in FIG. 1, the inside of the pod 20 can distribute | circulate the plating solution 6 through the meshes 23 and 24 attached to the upper and lower sides.

  The roughness of the meshes 23 and 24 is determined so that the work 50 accommodated in the pod 20 so as to be freely taken out is not leaked to the outside of the pod 20 and the plating solution can be smoothly distributed. The pod 20 may contain a large number of conductive media for ensuring electrical continuity between the work 50 and the cathode electrode 30 together with the work 50 as an object to be plated.

  The outer circumferences of the mounting rings 25 and 26 in the pod 20 are slidable with respect to the inner wall of the accommodation space 8 a formed in the syringe 8, and the syringe 8 moves relative to the pod 20 in the vertical direction. It has become easier. Therefore, the outer periphery of the attachment rings 25 and 26 and the inner wall of the accommodation space 8a may be separated.

  As shown in FIG. 1, the rod-shaped cathode electrode 30 and the holding cylinder 34 are detachably fixed to the upper end of the shaft 32. The shaft 32 is connected to an elevating means 36 and a vibration means 38 for vibrating the inside of the pod 20 through the shaft 32.

  The elevating means 36 is not particularly limited, and examples thereof include a motor actuator and a fluid drive actuator. The vibration means 38 is not particularly limited, and examples thereof include an ultrasonic vibration application device, a piezoelectric element, and a motor actuator with a cam mechanism.

  By driving the elevating means 36, the shaft 32 can be moved in the vertical direction together with the pod 20, for example, as shown in FIG. 3 is a position where the work 50 is accommodated in the pod 20 or a position where the work 50 is taken out from the pod 20.

As shown in FIG. 1, a disc-shaped anode electrode 40 is disposed at the inner bottom of the tank body 4b, and the shaft 32 extends in the vertical direction through a central opening 40a formed in the anode electrode 40. It extends to. The anode electrode 40 is held at the inner bottom portion of the tank body 4b by the anode support portion 42, and power can be supplied through the conducting wire 42a.
Plating method

  Next, the plating method of this embodiment using the plating apparatus 2 shown in FIG. 1 will be described. First, the elevating means 36 shown in FIG. 1 is driven, and as shown in FIG. 3, the shaft 32 is moved upward together with the pod 20 to make the pod 20 higher than the level of the plating solution 6 in the tank body 4b. .

  The syringe 8 is lifted further upward than the pod 20 by the syringe holding member 10, and the pod 20 is positioned further below the lower end opening of the accommodation space 8 a of the syringe 8. At that position, the work 50 is accommodated in the pod 20 together with the medium. In order to accommodate the workpiece 50 together with the medium in the pod 20, for example, the attachment ring 25 and the mesh 23 may be removed from the main body 22.

  After that, if the attachment ring 25 and the mesh 23 are attached to the main body 22, the inside of the pod 20 communicates with the outside of the pod via the meshes 23 and 24 in a state where the work 50 is accommodated. Thereafter, as shown in FIG. 4, the lower end portion of the syringe 8 is moved downward together with the pod 20 in a state where the pod 20 is accommodated in the accommodation space 8 a of the syringe 8, and the plating solution 6 in the plating tank 4. Immerse completely inside.

  The plating solution 6 also enters the accommodation space 8 a of the syringe 8. Note that the valve 12 is preferably opened when the syringe 8 is moved downward. Further, when the syringe 8 is moved downward, the valve 12 may be opened and the pump 14 may be moved downward while pouring the plating solution 6 toward the accommodation space 8a through the supply passage 8b.

  Thereafter, the valve 12 shown in FIG. 4 is closed to close the supply passage 8b, and in this state, the syringe 8 is moved upward with respect to the pod 20 as shown in FIG. The air bubbles 6a that have been sucked up are sucked toward the upper part of the accommodation space 8a of the syringe 8.

  Meshes 23 and 24 are attached to the upper and lower ends of the pod 20. When the meshes of the meshes 23 and 24 are fine, bubbles easily remain inside the pod 20. According to this method, it is easy to suck up the bubbles 6a existing in the pod 20 toward the upper portion of the accommodation space 8a of the syringe 8. At that time, due to the suction pressure caused by the upward movement of the syringe 8, the workpiece 50 is lifted and stirred inside the pod 20. At that time, no electric power is supplied between the anode electrode 40 and the cathode electrode 10 immersed in the plating solution 6 and no plating process is performed. Therefore, it is possible to prevent a plating film from being formed on the cathode electrode and maintain a preferable contact state with the object to be plated.

  Next, the valve 12 shown in FIG. 1 is closed, and the syringe 8 is moved downward with respect to the pod 20 from the state shown in FIG. 5 as shown in FIG. Make a flow of plating solution downward. At that time, the first plating process is performed by applying a voltage between the anode electrode 40 and the cathode electrode 10 immersed in the plating solution 6.

  As shown in FIG. 6, after the syringe 8 moves down to the lowest position with respect to the pod 20, the valve 12 shown in FIG. 1 is opened and the pump 14 is activated to supply the plating solution from the tank to the supply passage 8b. Through the housing space 8a. In this state, the syringe 8 is moved upward with respect to the pod 20 as shown in FIG. 7 from the position shown in FIG. At that time, a voltage is applied between the cathode electrode 30 and the anode electrode 40.

  That is, the second plating process is performed on the workpiece 50 while supplying the plating solution from the supply passage 8 a formed inside the syringe 8 to create the flow of the plating solution 6 downward in the pod 20. At the same time, in this second plating step, the workpiece 50 is plated while vibrating the pod 20 using the vibration means 38 shown in FIG.

  As shown in FIG. 7, when the syringe 8 is moved to the upper limit position in the middle of the plating with respect to the pod 20, the valve 12 shown in FIG. 1 is then closed, and FIGS. As shown in FIG. 2, the first plating process described above is performed, and then the second plating process described above is performed. The bubble removal process shown in FIG. 5 may be performed at a predetermined timing every time after the first plating process and the second plating process are alternately repeated for a predetermined time.

  In the second plating step according to this embodiment, when the syringe 8 is moved upward with respect to the pod 20, the plating solution is supplied from the supply passage 8 b formed in the syringe 8 toward the pod 20. . Therefore, it is possible to create a downward plating solution flow inside the pod 20, and the workpiece 50 that rises when the syringe 8 is moved upward relative to the pod 20 (see FIG. 5). It is suppressed, electric conduction with the cathode electrode 30 with respect to the workpiece 50 is ensured, and plating is possible.

  In the second plating step, since the pod 20 is vibrated, the workpiece 50 inside the pod 20 is also plated while being appropriately stirred. Therefore, in the method of this embodiment, the plating process is performed not only in the first plating process but also in the second plating process, so that the plating process time can be shortened, and the plating film thickness is increased in a predetermined time. Production efficiency is improved.

  Moreover, in the second plating step, the workpiece 50 is plated while being stirred. In both the first plating step and the second plating step, a downward plating solution flow is formed inside the pod 20, and a fresh plating solution is always present around the workpiece 50 during the plating process. Supplied. Therefore, the ion concentration necessary for the plating process does not decrease around the workpiece 50. As a result, the quality of the plating film is improved and the plating efficiency is also improved.

  In particular, in the first plating step, the downward flow of the plating solution generated when the syringe 8 is moved downward with respect to the pod 20 is strong, and the work 50 in the pod 20 is pressed against each other by the flow of the plating solution. The energization efficiency between the workpieces 50 is improved. In this respect, the plating efficiency is improved.

  For the above reasons, in the method of this embodiment, a uniform plating film can be formed on a large amount of workpieces 50 at a time without causing defective plating.

  Moreover, in the plating method of this embodiment, since a bubble removal process is performed before a 1st plating process, it can prevent effectively that the plating thing floats by a bubble, a bubble adhesion part is not plated, etc. .

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, the plating apparatus for realizing the method of the present invention is not limited to the apparatuses shown in FIGS.

FIG. 1 is an overall schematic view of a plating apparatus according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the pod shown in FIG. FIG. 3 is a schematic view showing the movement of the plating apparatus shown in FIG. FIG. 4 is a schematic diagram showing a continuation of the movement of FIG. FIG. 5 is a schematic diagram showing the continuation of FIG. FIG. 6 is a schematic diagram showing the continuation of FIG. FIG. 7 is a schematic diagram showing the continuation of FIG. FIG. 8 is a schematic diagram showing the continuation of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Plating apparatus 4 ... Plating tank 6 ... Plating solution 8 ... Syringe 8a ... Accommodating space 8b ... Supply passage 12 ... Valve 14 ... Pump 20 ... Pod 30 ... Cathode electrode 40 ... Anode electrode 50 ... Workpiece (to-be-plated object)

Claims (4)

A syringe that is movably arranged with respect to a pod containing an object to be plated immersed in a plating solution stored inside the plating tank is moved downward with respect to the pod, and inside the syringe, A first plating step for creating a flow of a plating solution in a downward direction inside the pod and performing a plating process on the object to be plated;
The syringe is moved upward with respect to the pod, and a plating solution is supplied from a plating solution supply passage formed inside the syringe to create a flow of the plating solution downward in the pod. And a second plating step for performing a plating process on the object to be plated,
In the second plating step, a plating method for plating the object to be plated while vibrating the pod.   Before the first plating step, the plating solution supply passage is closed and the syringe is moved upward with respect to the pod, and the upper part of the pod toward the inside of the syringe, The plating method according to claim 1, further comprising a bubble removing step of sucking up bubbles present inside. A cathode electrode is arranged so that the object to be plated accommodated in the pod can be contacted, and the anode electrode is in contact with the plating solution accommodated in the plating tank,
In the first plating step and the second plating step, a voltage is applied between the anode electrode and the cathode electrode,
The plating method according to claim 2, wherein no voltage is applied between the anode electrode and the cathode electrode in the bubble removing step.   The plating method according to claim 1, wherein in the first plating step, the plating solution supply passage is closed and the syringe is moved downward relative to the pod.

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