JP5366787B2 - Continuous vertical transfer plating equipment - Google Patents

Description

  The present invention relates to a continuous vertical conveyance type plating apparatus for continuously conveying and plating a flat workpiece such as a hoop material or a printed board held in a vertical posture.

  As a continuous vertical conveyance type plating apparatus that vertically conveys a plate-like workpiece such as a hoop material or a printed circuit board, one as shown in Patent Document 1, for example, has been put into practical use, and the workpiece has an upper portion. It is held by a power feeding grip and is fed from above through the power feeding grip. Normally, the liquid level of the plating solution is adjusted to almost the same height as the lower end of the power supply grip, and it is natural that the part held by the power supply grip of the workpiece above the liquid level of the plating solution is not plated. In the upper part of the workpiece close to the plating solution level, the plating film thickness tended to be thin.

  The plating of such workpieces to be plated by a continuous vertical transfer plating machine is often copper plating, and additives are added to improve uniform electrodeposition, but the workpiece is close to the plating solution level. The current density is lower in the upper part of the plate, and the tendency for the plating film thickness to become thinner than other parts of the workpiece is not eliminated. Conventionally, the parts that are not plated and the parts with the thin plating film thickness are cut and discarded. . On the other hand, from the viewpoint of effective use of resources and cost reduction, there is a strong demand to reduce the number of discarded parts so that plating can be performed with a uniform plating film thickness near the upper end of the workpiece.

JP 2004-277783 A

  As described above, in the continuous vertical transfer plating machine that feeds power to the work from the top through the power supply grip, the plating film thickness on the top of the work close to the surface of the plating solution becomes thin, and that part cannot be used effectively. There was a problem. A method of making the plating film thickness of the upper part of the workpiece close to the plating solution level uniform with other parts of the workpiece has not been put into practical use at present, and such a document cannot be found.

  The present invention is intended to solve the above problems, and can be plated with a uniform plating film thickness on the upper part of the work near the liquid surface of the plating solution with other parts of the work. The object is to realize a plating apparatus.

In order to achieve the above object, the present invention provides a continuous vertical transport plating apparatus for continuously transporting a plate-shaped workpiece in a vertical posture and plating it in a position facing the upper portions of both surfaces of the workpiece. Provide an auxiliary anode that extends in the direction of the workpiece in parallel with the plating solution surface, connect the auxiliary anode to the positive electrode of the auxiliary DC power supply, connect the negative electrode of the auxiliary DC power supply to the workpiece, and supply the auxiliary DC power supply. The output current of the apparatus is set to 1% to 10% of the plating current flowing from the anode to the workpiece. Here, it is preferable that the auxiliary anode is an insoluble electrode constituted by a molded rod.

  The operation of the above problem solving means is as follows. That is, the plating current from the anode is smaller at the upper part of the work than the other parts of the work, but the reduced plating current flows from the auxiliary anode, and a sufficient plating current also flows from the upper part of the work. The thickness is never reduced. When the auxiliary anode is an insoluble electrode composed of a molded rod, the auxiliary anode is easy to process, and the auxiliary anode does not block the plating current from the anode, and the existing continuous vertical conveyance plating apparatus There is also an advantage that can be easily provided.

  As described above, in the continuous vertical conveyance plating apparatus of the present invention, the reduced plating current flows from the auxiliary anode in the upper part of the work where the plating current from the anode is smaller than that in the other parts of the work. Therefore, there is an effect that a sufficient plating current flows even at the upper part of the work and the plating film thickness is not reduced.

It is a longitudinal cross-sectional view of the principal part which shows embodiment of this invention. It is a top view of the principal part which shows embodiment of this invention.

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

  In the figure, reference numeral 1 denotes a plating tank, the dimension in the length direction is determined according to the required plating thickness, and the workpiece W is conveyed in the center of the plating tank 1. FIG. 1 is a longitudinal sectional view of the plating tank 1 as seen from the front of the workpiece in the traveling direction. FIG. 2 is a plan view showing a part on the outlet side of the plating tank 1. In FIG. The process proceeds from top to bottom as shown by the arrows in FIG. Although not shown in FIG. 2, the workpiece W is held by a plurality of power feeding grips 2. A rail 3 that supports the power feeding grip 2 and a power feeding grip 2 are moved to the upper part of the plating tank 1 to convey the workpiece. And a conveying device (not shown). Moreover, although not shown in figure, the liquid leakage prevention apparatus similar to the conventional continuous vertical conveyance type plating apparatus is provided in the side wall of the front end and rear end of the plating tank 1. FIG.

  The plating tank 1 is provided with a large number of nozzles 4, 4 for injecting a plating solution toward the workpiece W side by side in the vertical direction and the traveling direction of the workpiece. The large number of nozzles 4 and 4 are attached to columnar nozzle mounting bases 5 and 5 each provided with a plating solution supply path. The nozzle mounting bases 5 and 5 are provided so as to rise from the bottom of the plating tank 1. ing. A plating solution is supplied to the nozzle mounting bases 5 and 5, and the plating solution is sprayed from the nozzles 4 and 4 toward the work W through the nozzle mounting bases 5 and 5.

  A large number of vertical guide shafts 6, 6 are arranged in the moving direction of the workpiece between the nozzles 4, 4 and the workpiece W, and each guide shaft 6, 6 has a plurality of guide disks 7, 7. Is rotatably mounted on the shaft. A plurality of anodes 8, 8 are arranged outside the nozzle mounting bases 5, 5 in the direction in which the workpiece W travels. The nozzles 4 and 4, the nozzle mounting bases 5 and 5, the guide shafts 6 and 6, the guide disks 7 and 7, and the anodes 8 and 8 are arranged symmetrically around the workpiece W, and the plating solution is supplied from the nozzles 4 and 4. Sprayed on both sides of the workpiece W. Further, the workpiece W is guided by the guide disks 7 and 7 so as not to swing, and a plating current is supplied from the anodes 8 and 8.

  Auxiliary anodes 9, 9 that are long in the traveling direction of the workpiece W are provided in parallel to the workpiece W and the liquid surface of the plating solution, respectively, at positions facing the workpieces W on both sides of the workpiece W. The auxiliary anode 9 is preferably a rod-like insoluble electrode obtained by plating a titanium material with platinum, for example, and is preferably provided at a position within 30 mm from the surface of the plating solution and 20 mm to 50 mm away from the workpiece. Moreover, it is preferable that the auxiliary anode 9 has a length of one third or more of the entire length of the plating tank 1. The illustrated one is a platinum-plated titanium bar with a diameter of about 6 mm that has been bent. Both ends of the auxiliary anode holders 10 and 10 made of an insulating material attached to the nozzle mounting bases 5 and 5 are bent. It is attached.

  As with the conventional continuous vertical conveyance type plating apparatus, the anodes 8 and 8 are several sets that are continuous in the moving direction of the workpiece W, and are divided into several sets with respect to the entire length of the plating tank 1. It has become a shape. The anodes 8 and 8 are respectively connected to positive electrodes of a plating DC power supply device (not shown) provided in the same number as the number of sets for each set. Each of the auxiliary anodes 9 has a length substantially the same as the length of each set of the anodes 8 and 8 and is connected to a positive electrode of an auxiliary DC power supply device (not shown) provided in the same number as the auxiliary anodes 9.

  The auxiliary anode 9 can be provided corresponding to all the sets of the anodes 8 and 8, and can be provided corresponding to a part of the set of the anodes 8 and 8. When provided corresponding to a part of the set of anodes 8, 8, it is preferably provided corresponding to the set of anodes 8, 8 close to the outlet side of the plating tank 1. The negative poles of the plating DC power supply and the auxiliary DC power supply are both connected to the rail 3. In the figure, the anodes 8 and 8 are divided into three sets, and the auxiliary anode 9 is provided on the outlet side of the plating tank 1 so as to have substantially the same length as the set of the anodes 8 and 8 on the outlet side of the plating tank 1. .

  Therefore, in the case of this illustrated one, three DC power supply devices for plating and one auxiliary DC power supply device are provided. The plating DC power supply device and the auxiliary DC power supply device are both controlled at a constant current, and the current of the plating power supply device is proportional to the area of the work W facing each set of anodes 8 and 8 as the work W progresses. Is set to the specified value. Further, the current of the auxiliary DC power supply device is set such that the sum of the currents of the auxiliary DC power supply device is in a range of 1 to 10% of the total current of the power supply device for plating. The difference between the plating film thickness of the upper part of the workpiece W and the plating film thickness of the other part is adjusted while observing the measurement result.

  In the continuous vertical conveying plating apparatus of the present invention configured as described above, the workpiece W is held by the power feeding grips 2 and 2 similarly to the conventional continuous vertical conveying plating apparatus, and the feeding grips 2 and 2 are held by the conveying device. Is moved in the plating tank 1 by moving. Further, the plating solution is sprayed from the nozzles 4 and 4 onto both surfaces of the workpiece W, and the plating tank 1 is filled with the plating solution. Since the power feeding grips 2 and 2 are supported by the rail 3, the work W is electrically connected to the negative pole of the plating DC power supply device and the auxiliary DC power supply device. As a result, a plating current flows from the plating DC power supply device to the entire workpiece W through the anodes 8 and 8, and in addition, a plating current flows from the auxiliary DC power supply device to the upper portion of the workpiece W through the auxiliary anode 9. become.

  Therefore, in addition to the plating current from the anodes 8 and 8, the plating current from the auxiliary anode 9 flows in the upper part of the work W, and the plating current from the anodes 8 and 8 that is smaller than the other parts of the work W is the auxiliary anode. 9 is compensated by the plating current from 9, the plating film thickness on the upper portion of the workpiece W is not reduced by a sufficient current flow. In the above embodiment, the auxiliary anode is platinum plated on a titanium rod, but it goes without saying that it may be a square bar and has a shape that does not shield the plating current from the anode to the workpiece. If possible, a lath net, a plate, or the like can be used.

  When a copper substrate having a plating film thickness of 25 μm was plated on a printed board having a height direction of 330 mm by a conventional continuous vertical conveyance plating apparatus, the plating film thickness in the range of 30 mm below the plating solution was 23 μm to 20 μm. On the other hand, an auxiliary anode plated with platinum on a 6 mm diameter titanium rod is provided over the entire length of the plating tank so that the center of the cross section is located 3 mm below the surface of the plating solution and 30 mm away from the workpiece. When a current of 2% of the plating current was passed through the auxiliary anode, the plating film thickness in the range from 5 mm to 30 mm below the plating solution level was also 25 μm.

DESCRIPTION OF SYMBOLS 1 Plating tank 2 Feeding grip 3 Rail 4 Nozzle 5 Nozzle mounting base 6 Guide shaft 7 Guide disk 8 Anode 9 Auxiliary anode 10 Auxiliary anode holder

Claims (2)

In a continuous vertical transport plating machine that continuously transports flat workpieces in a vertical position and plating them, the workpiece is placed in a direction facing the top of both sides of the workpiece and parallel to the surface of the plating solution. A long auxiliary anode is provided, the auxiliary anode is connected to the positive electrode of the auxiliary DC power supply, the negative electrode of the auxiliary DC power supply is connected to the work, and the output current of the auxiliary DC power supply flows from the anode to the work. A continuous vertical transfer plating apparatus characterized by being set to 1% to 10%.   2. The continuous vertical conveyance type plating apparatus according to claim 1, wherein the auxiliary anode is an insoluble electrode composed of a molded bar.

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