JP2012025987A - Rack type plating device and rack type plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable equal film forming in performing rack type plating excellent in quality, productivity, and working efficiency.SOLUTION: The rack type plating device includes a plating tank 2 into which a plating liquid 1 is poured, a rack 4 capable of holding an object to be treated, and a hanger 3 arranged in the plating tank 2, capable of holding the rack 4, and functioning as a cathode. The rack 4 includes: a net-like workpiece holder 7 capable of enveloping the object to be treated; two negative charge feeding parts respectively connected to different positions of the object to be treated held by the workpiece holder 7; and a cathode connection switching part selectively conducting any one of the negative charge feeding parts with the hanger 3. The rack 4 is relatively movable to the hanger 3. By the relative movement of the rack 4 to the hanger 3, the negative charge feeding parts connected by contact with a conductor exposed part 3a of the hanger 3 are switched by the cathode connection switching part.

Description

  The present invention relates to a rack type plating apparatus and a rack type plating method.

  Plating is widely used as a method for forming a film on a workpiece (workpiece). As a general plating method for a plurality of workpieces, a barrel-type plating method (also referred to as a glass plating method or a rotating plating method) as disclosed in Patent Document 1 and a technique disclosed in Patent Document 2 are disclosed. Rack-type plating methods (also called hook plating methods or static plating methods).

  In the barrel type plating method, a plurality of workpieces and a plating solution are placed in a barrel made of synthetic resin having a large number of small holes, and the workpiece is immersed in the plating solution. And it is the method of plating, rotating this barrel.

  In the rack type plating method, a jig (rack) for holding a work is prepared, and the work is held on the rack. Then, a plurality of racks holding workpieces are suspended on a cathode bar (bus bar), the plurality of racks and workpieces are put into a plating tank into which a plating solution has been poured, and the workpieces are immersed in the plating solution for plating. It is a method to do.

JP 2010-1534 A JP 2008-13822 A

  In the case of the barrel type plating method disclosed in Patent Document 1, an anode and a cathode are provided on the barrel (in the case of Patent Document 1, an anode rod is provided on the outer side of the barrel, and a cathode terminal is provided on the inside of the barrel. Are each energized). However, since the current density cannot be set so high, the plating rate is slow and it is difficult to form a thick plating layer. In addition, in a plurality of workpieces, the thickness of the formed plating layer is likely to vary, and it is difficult to obtain a uniform film. Furthermore, there are problems such as a relatively large amount of plating solution used, complicated management of the plating solution, and a large loss of the plating solution.

  On the other hand, in the case of the rack type plating method disclosed in Patent Document 2, an electrode (an anode in Patent Document 2) is provided on the rack, and electricity is supplied using the anode and the cathode bar. This rack-type plating method is advantageous in that the thickness of the formed plating layer does not easily vary among a plurality of workpieces, and a uniform film can be easily obtained. Moreover, since the current density can be set high, the plating rate can be high and the plating layer can be formed thick. Furthermore, it is easy to manage work such as management of plating solution and waste water treatment. Thus, the rack type plating method is excellent in quality, productivity, and workability.

  However, in the rack-type plating method, the rack is usually covered with an insulating material, and when the rack holding the work is transported, when the rack is put into the plating tank and the work is immersed in the plating solution, etc. Vibrations, shocks, etc. may occur on the workpiece, and the workpiece may come into contact with the insulating material covering the rack. Since it is difficult to form a plating layer on the part of the workpiece that is in contact with the insulating material, it is impossible to form a uniform film.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rack type plating apparatus and a rack type plating method capable of forming a uniform coating film as compared with the prior art when performing rack type plating excellent in quality, productivity and workability. There is.

  The present invention includes a plating tank into which a plating solution is poured, a rack capable of holding an object to be processed, and a hanger provided in the plating tank and capable of holding the rack and functioning as a cathode. In the type plating apparatus, the rack is provided with a net-like work holder made of an insulating material and capable of enclosing the object to be processed, and a position to be opposed to each other with the work holder interposed therebetween. Two negative charge supply units connected to the respective positions, and a cathode connection switching unit that selectively conducts either one of the negative charge supply units with the hanger. It is covered with an insulating material except for the exposed part of the conductor connected to the charge supply part and the connection part to the power supply. The negative charge supply part is made of a conductive material and is held by the work holder. The rack is movable relative to the hanger except for the contact area with the workpiece to be processed, and is connected in contact with the exposed conductor of the hanger through the relative movement of the rack with respect to the hanger. The negative charge supply unit is switched by the cathode connection switching unit.

  According to the present invention, by changing the position of the rack holding the workpiece without interrupting conduction, a specific portion of the workpiece continues to contact the insulating material, and a plating layer is not easily formed. This prevents a plating layer (film) having a relatively uniform thickness.

It is sectional drawing which shows the rack type plating apparatus of the 1st Embodiment of this invention. It is a perspective view which shows the rack of the rack type plating apparatus shown in FIG. (A) is a perspective view which shows the state which decomposed | disassembled the work holder of the rack shown in FIG. 2, (b) is sectional drawing of the connection state. It is a perspective view which shows the negative charge supply part of the rack shown in FIG. It is explanatory drawing which shows the attitude | position change of the rack in the rack type plating apparatus shown in FIG. 1, and the switching state of cathode connection. It is a front view which shows the state which changed the mesh density of the work holder of the rack shown in FIG. It is sectional drawing which shows the rack type plating apparatus of the 2nd Embodiment of this invention.

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

  FIG. 1 shows a first embodiment of the rack type plating apparatus of the present invention. In this plating apparatus, a hanger 3 is provided in a glass plating tank 2 into which a plating solution 1 is poured. The hanger 3 is made of a conductive material such as copper or aluminum, except for a conductor exposed portion that is a holding portion 3a of the rack 4 described later and a central portion (connection portion to the power source 5) 3d that contacts a contact 5a described later. Covered with insulating material. The hanger 3 is provided with a plurality of holding portions 3a in the annular portion 3b, and the annular portion 3b can rotate around the center portion 3d of the support portion 3c having the diameter of the annular portion 3b. The central portion 3d of the hanger 3 is rotatably contacted with a contact 5a connected to the cathode of the power source 5 schematically shown in FIG. 1, and the entire hanger 3 is connected to the cathode of the power source 5. Yes. Accordingly, the holding portion (conductor exposed portion) 3a of the hanger 3 functions as a cathode terminal. A terminal 5b connected to the anode of the power source 5 is disposed in the plating tank 2 (in the plating solution 1). Further, a projection 2 a is formed in the plating tank 2 at a position where it can contact the rack 4 held on the hanger 3.

  Next, the rack 4 will be described. As shown in FIG. 2, which is a perspective view, the rack 4 includes a net-like work holder 7 made of an insulator such as plastic or ceramic and surrounding and holding an object (work) 6 to be processed. As shown in FIG. 3, the work holder 7 is formed by connecting one or more (two in the example shown in FIG. 3) mesh bodies 7 a and 7 b having a curved inner surface to connect the entire circumference of the work 6. Can be surrounded and held. The work holder 7 may be configured to hold only one work 6, but may be capable of holding a plurality (four in the example shown in FIG. 2) of works 6 simultaneously.

  A pair of negative charge supply units 8 and 9 are arranged so as to sandwich the work holder 7 from both sides (the upper side and the lower side in FIG. 3), and are held by the base 10. Each of the negative charge supply units 8 and 9 is in contact with a different position (upper and lower in the example shown in FIG. 2) of the workpiece 6. As shown in FIG. 4 which is a perspective view, the negative charge supply portions 8 and 9 are made of a conductive material such as copper or aluminum, and are covered with an insulating material except for contact portions 8a and 9a with the workpiece 6. The base 10 made of a conductive material such as copper or aluminum as in the case of the negative charge supply units 8 and 9 and covered with an insulating material is provided with long holes 10a, and both ends of the long holes 10a (shown in FIG. 2). In the example, connection terminals 11 and 12 are provided on the inner walls of the upper end and the lower end, respectively. Conductive paths 13 and 14 that are independent from each other are provided inside the base 10, and one connection terminal 11 is connected to the lower negative charge supply unit 9 through the conductive path 13. The other connection terminal 12 is connected to the upper negative charge supply unit 8 through the conductive path 14.

  In the present embodiment, a plurality of such racks 4 are held on the hanger 3. Specifically, the base 10 is rotatably held by the holding part 3 a of the hanger 3 by inserting the shaft-like holding part 3 a into the elongated hole 10 a of the base 10 of the rack 4. The base 10 holds a pair of negative charge supply units 8 and 9 and a work holder 7. Therefore, as shown in FIG. 1, a plurality of racks 4 are held on the annular portion 3 b of the hanger 3.

  According to this configuration, from the cathode of the power source 5, the center part 3 d of the hanger 3, the support part 3 c, the annular part 3 b, the holding part (conductor exposed part) 3 a, the connection terminal 11 (or 12) of the rack 4 and the conductive path 13 (or 14) is conducted to the contact portion 9a (or 8a) of the negative charge supply section 9 (or 8). And when the workpiece | work 6 is hold | maintained at the workpiece holder 7, a negative charge is supplied to the workpiece | work 6 which contacts the contact part 9a (or 8a) of the negative charge supply part 9 (or 8). On the other hand, a positive charge is supplied from the anode of the power supply 5 to the plating solution 1 through the terminal 5b. That is, a negative charge is supplied to the work 6 from the holder 3 and a positive charge is supplied to the plating solution, whereby electrolytic plating is performed, and Ni, Cu, Sn, Ag, Au or the like is formed on the surface of the work 6. A plating layer is formed.

  In the present embodiment, the hanger 3 is rotated, for example, counterclockwise around the central portion 3a. In the middle of this rotation, the plurality of racks 4 abut on the protrusions 2a in order in the plating tank 2. As shown in FIG. 5, the rack 4 in contact with the protrusion 2a starts to rotate clockwise around the holding portion 3a. FIG. 5 shows the racks 4 at different stages in rotation. Since the holding portion (conductor exposed portion) 3a is only movably accommodated without being fixed in the long hole 10a, the holding portion 3a is long when the base body 10 and the long hole 10a are in a nearly horizontal posture. It begins to slide in the hole 10a. When the rack 4 further rotates clockwise, the rack 4 is pushed by the protrusion 2a and starts to tilt from a horizontal state, and then descends at a stroke due to gravity. The relative movement of the rack 4 with respect to the hanger 3 is that the holding portion (conductor exposed portion) 3a moves relatively from one connection terminal 11 side to the other connection terminal 12 side, for example. When the rack 4 gets over the protrusion 2a, as shown by reference numeral A in FIG. 5, the rack 4 is turned upside down (rotated 180 degrees) from the position before contacting the protrusion 2a. As the rack 4 is turned upside down, the holding portion (conductor exposed portion) 3 a is switched from a state in contact with one connection terminal 11 to a state in contact with the other connection terminal 12. Thereby, from the cathode of the power source 5 through the center part 3d of the hanger 3, the support part 3c, the annular part 3b, the holding part (conductor exposed part) 3a, the connection terminal 11 and the conductive path 13 of the rack 4, From the state of conducting to the contact portion 9a of the negative charge supply unit 9 and supplying the negative charge to the workpiece 6 in the work holder 7, from the cathode of the power source 5, the central portion 3d of the hanger 3, the support portion 3c, the annular portion 3b, The conductive portion is electrically connected to the contact portion 8a of the negative charge supply portion 8 through the holding portion (conductor exposed portion) 3a, the connection terminal 12 and the conductive path 14 of the rack 4, and negative charges are applied to the workpiece 6 in the work holder 7. Switch to the supply state.

  In this way, the cathode connection switching portion is constituted by the elongated hole 10a into which the shaft-shaped holding portion (conductor exposed portion) 3a is inserted and the connection terminals 11 and 12 formed on the inner walls at both ends of the elongated hole 10a. Has been.

  When the hanger 3 continues to rotate and the rack 4 that is turned upside down (rotated 180 degrees) comes to a position where it comes into contact with the protrusion 2a again, the rack rotates 180 degrees clockwise again as described above. Thus, the state returns to the initial state (a state in which negative charges are supplied to the workpiece 6 via the connection terminals 11 of the rack 4, the conductive paths 13, and the contact portions 9a of the negative charge supply unit 9). In this way, every rotation of the hanger 3 repeats the clockwise rotation of 180 degrees around the holding portion (conductor exposed portion) 3a of the rack 4.

  Since the contact 5b and the central part 3b of the hanger 3 are in contact with each other so as to be rotatable, the conduction is not interrupted while the rack 4 rotates clockwise as described above. Accordingly, as described above, the posture of the rack 4 holding the workpiece 6 can be changed and the conduction state can be switched while the electrolytic plating is progressing. As a result, even if a part of the workpiece 6 is in contact with the insulating material, the portion of the workpiece 6 in contact with the insulating material changes as the posture of the rack 4 changes. That is, since a specific part of the work 6 does not continue to contact the insulating material, there is no part where the plating layer is difficult to form in particular, and the plating layer (coating) having a relatively uniform thickness does not exist. Can be formed.

  Of course, in the present invention, the advantage of the rack-type plating method is maintained that the plating speed is high and the plating layer can be formed thick, and the management of the plating solution 1 and the work management such as drainage treatment are easy.

  FIG. 6 shows a work holder 7 in which a rod 15 is added to the net-like work holder 7 shown in FIG. In this way, when the work holder 7 is configured so that the density of the mesh can be changed by using the detachable bar 15, it can be appropriately held according to the size and shape of the work 6, The balance between the area where the workpiece 6 is in contact with the plating solution 1 from the mesh gap and the area where the workpiece 6 is in contact with the insulating material can be appropriately adjusted. Therefore, it is possible to deal with a wide range of workpieces 6 of various sizes and shapes.

  FIG. 7 shows a second embodiment of the rack type plating apparatus of the present invention. In this rack type plating apparatus, the plating tank 1 containing the hanger 3 capable of holding the same rack 4 as in the first embodiment described above contains the ultrasonic generator 16 and the ultrasonic tank 17 into which water has been injected. It is placed inside. In the present embodiment, ultrasonic vibration is intermittently generated by the ultrasonic generator 16 of the ultrasonic layer 17 and transmitted to the plating solution 1 and the workpiece 6 in the plating tank 2. Thereby, even if a part of the workpiece 6 is in contact with the insulating material, a gap is generated between the workpiece 6 and the insulating material by ultrasonic vibration, and the plating solution 1 is allowed to enter the gap. This contributes to further uniformization of the thickness of the plating layer (coating) by eliminating as much as possible the places where the plating layer is difficult to form.

DESCRIPTION OF SYMBOLS 1 Plating solution 2 Plating tank 2a Protrusion 3 Hanger 3a Holding part (conductor exposed part)
3b annular part 3c support part 3d center part (connection part to power supply)
4 Rack 5 Power supply 5a Contact 5b Terminal 6 Object to be processed (work)
7 Work holders 7a and 7b Nets 8 and 9 Negative charge supply portions 8a and 9a Contact portion 10 Base 10a Slots 11 and 12 Connection terminals 13 and 14 Conductive path 15 Bar 16 Ultrasonic generator 17 Ultrasonic tank

Claims (10)

Rack-type plating comprising: a plating tank into which a plating solution is injected; a rack capable of holding an object to be processed; and a hanger provided in the plating tank and capable of holding the rack and functioning as a cathode. A device,
The rack is made of an insulating material and can be surrounded by a net-like work holder that can surround the object to be processed, and the work object held by the work holder is different from the object to be processed. Two negative charge supply units each connected to a position, and a cathode connection switching unit that selectively conducts either one of the negative charge supply units with the hanger,
The hanger is made of a conductive material, and is covered with an insulating material except for a conductor exposed portion connected to the negative charge supply portion of the rack and a connection portion to a power source,
The negative charge supply unit is made of a conductive material, and is covered with an insulating material except for a contact portion with the object to be processed held by the work holder,
The rack is movable relative to the hanger, and the negative charge supply unit connected in contact with the exposed conductor portion of the hanger by the relative movement of the rack with respect to the hanger is caused by the cathode connection switching unit. Switchable rack type plating equipment.   While the rack is held on the hanger, the work holder and the object to be processed are rotated 180 degrees by rotating the conductor exposed portion of the hanger about 180 degrees, and the cathode connection switching unit, From the state in which the conductor of the hanger is electrically connected to the object to be processed through one negative charge supply unit, the object to be processed from the conductor exposed part of the hanger through the other negative charge supply unit The rack type plating apparatus according to claim 1, wherein the rack type plating apparatus is switched to a state of being electrically connected to each other.   The cathode connection switching unit is provided on a base of the rack, and is formed in a long hole into which the conductor exposed portion of the hanger is inserted, and an inner wall at both ends of the long hole, respectively, and the negative charge supply unit The rack-type plating apparatus according to claim 2, further comprising: two connection terminals connected to each other, wherein the connection terminal with which the exposed conductor portion contacts is switched by moving the hanger within the elongated hole. .   A protrusion is provided in the plating tank, and when the rack is engaged with the protrusion in the plating tank, the rack is held by the hanger and rotated 180 degrees around the conductor exposed portion of the hanger. The rack type plating apparatus according to claim 3, wherein   The rack type plating apparatus according to any one of claims 1 to 4, wherein the work holder is detachable from the negative charge supply unit and the cathode connection switching unit.   The rack type plating apparatus according to any one of claims 1 to 5, wherein the work holder has a mesh shape with an inner surface curved so as to surround the workpiece, and the density of the mesh can be changed.   The rack type plating apparatus according to any one of claims 1 to 6, wherein an ultrasonic vibration generator is provided adjacent to the plating tank. A step of holding an object to be processed by a work holder of the rack; a step of holding the rack holding the object to be processed by a hanger provided in a plating tank and functioning as a cathode; and the plating tank Immersing the object to be processed held in the rack in an inner plating solution,
A state in which a negative charge is supplied from the exposed conductor portion of the hanger to the object to be processed held by the work holder via one negative charge supply portion provided in the rack, and the hanger A state in which a negative charge is supplied to the object to be processed held by the work holder from a conductor exposed portion via the other negative charge supply unit provided in the rack. A rack-type plating method that switches by relative movement. The step of holding the rack by the hanger is performed by inserting the conductor exposed portion of the hanger into a long hole provided in a base attached to the rack,
The work holder and the object to be processed are rotated 180 degrees by rotating the rack 180 degrees around the exposed conductor portion of the hanger while being held by the hanger, and the inner walls at both ends of the elongated hole are rotated. From the state where the exposed conductor portion of the hanger is in contact with one connection terminal of the two connection terminals, each formed and connected to the negative charge supply unit, the other connection terminal of the hanger Switch to the state where the exposed conductor is in contact,
The rack type plating method according to claim 8.   The rack type plating method according to claim 8 or 9, wherein ultrasonic vibration is transmitted to the plating solution and the object to be processed in the plating tank.

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