JPH036400A - Power supply method in continuous plating - Google Patents

Abstract

PURPOSE:To eliminate the need for a feeder for each treating tank and to efficiently carry out pretreatment using a heavy current at the time of pretreating the materials to be plated connected in the form of a band by continuously carrying out pretreatment such as electrolytic degreasing and electrolytic polishing prior to plating with the same power source. CONSTITUTION:When a continuous material 1 is plated with a noble metal such as gold, the material is degreased, polished and cleaned as pretreatment. The material 1 is moved in direction of the arrow, passed through an electrolytic degreasing tank 2, a pickling tank 4, a chemical polishing tank 5 and an electrolytic polishing tank 3 and cleaned. The cleaned material is passed through an Ni strike plating bath 7 and then sent to a noble metal plating bath. In this case, the positive pole of a power source 8 is connected to the electrode plate 22 of the electrolytic degreasing tank 2 to electrolytically degrease the material with a heavy current, and the negative pole of the power source 8 is connected to the electrode plate 32 of the electrolytic polishing tank 3 to electrolytically polish the material with a heavy current. Consequently, a heavy current is applied to the electrolytic degreasing tank 2 and electrolytic polishing tank 3 without contact with the material 1, contact power supply to the material 1 is not needed, and the material is pretreated with good power efficiency.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a continuous plating method in which noble metal plating, etc. is performed continuously on a continuous belt-shaped object to be plated. The purpose is to eliminate the need for direct power supply and enable high-speed, large-current electrolytic processing.When performing plating pretreatment for continuous plating on objects connected in a strip, the + side of the same power supply is connected to the Connect the negative side to the electrode plate of the electrolytic degreasing tank and the negative side to the electrode plate of the electrolytic polishing tank,
The structure is such that an electrolytic degreasing process using the object to be treated as a cathode and an electrolytic polishing process using the object to be treated as an anode are performed at the same time, thereby supplying the same current to the object through the respective electrolytes.

[Industrial application field]

The present invention relates to a continuous or valley method in which noble metal plating or the like is continuously applied to a continuous belt-shaped object to be plated, and particularly to a power supply method in electrolytic treatment in pre-treatment for plating.

When manufacturing lead frames for electronic components, contacts for connectors, etc., metal strips are processed continuously using progressive press processing, etc., and the strip members connected with unit wave plating are passed through continuous plating equipment to achieve high-speed continuous processing. Although plating is performed, it is desired to improve the performance of the power supply method for the electrolytic treatment performed as a pretreatment for this plating.

[Conventional technology]

In the manufacturing process of electronic components, precious metals such as Au and Pc1 are selectively plated on minute parts of the metal surface for use in contacts, bonding pads, etc., but these treatments are connected in a band shape. The method of continuously plating the objects to be plated has come to be widely used because of its excellent mass productivity.

In these apparatuses that perform partial precious metal plating continuously at high speed, pre-plating treatment is performed to clean the surface of the object to be plated in order to properly adhere the target plating.

In addition to non-electrolytic treatments such as pickling and chemical polishing, pre-treatment includes electrolytic degreasing of the object to be plated to remove oil that has adhered during press working, and electropolishing to clean and smooth the surface to be plated. Plating is often carried out, and several types of electrolytic treatment tanks for this purpose are placed upstream of the continuous plating equipment.

In these multiple electrolytic treatment steps, the object to be treated exchanges electric charge with the electrolyte as an anode or a cathode while passing through the electrolyte, and therefore it is necessary to supply electricity to the object.

Conventionally, separate power sources were prepared for each electrolytic treatment process.
As shown in FIG. 2, which shows the contact power feeding method, the guide roller 11
Then, the moving object 1 to be processed was pressed and brought into contact with a metal roller 12 connected to a power source, and current was directly supplied from the metal roller 12 to the object 1 to be processed.

[Problem to be solved by the invention]

In electrolytic treatments such as electrolytic degreasing and electrolytic polishing performed as pre-plating treatments, it is desirable to supply a large current to perform electrolytic treatments, since the higher the current density, the better the quality can be obtained in a shorter time. on the other hand,
In order to improve the efficiency of plating processing, it is desirable to allow the object to be plated to pass through the plating apparatus at high speed. However, in the above-mentioned direct power supply method using a metal roller, if the workpiece is brought into contact with the metal roller and the workpiece is moved at high speed, the contact becomes unstable and heat generated by sparks at the contact area may damage the workpiece or the metal roller. Failure to conduct electricity such as current interruption occurs. For this reason, the use of a large current during high-speed conveyance poses a problem in that power supply troubles occur frequently and the operating rate of the plating apparatus and product quality deteriorate.

The present invention was created in view of the above problems, and combines a pair of electrolytic treatments that are opposite to each other among the electrolytic treatments necessary as pre-treatments for plating. By passing the current flowing into and out of the two objects to be treated during electrolytic treatment and using them to supply power to each other, direct power supply to the objects to be treated becomes unnecessary and high-speed, large-current electrolytic treatment is possible. The purpose is to

[Means to solve the problem]

The problem mentioned above is that when performing plating pretreatment for continuous plating on objects connected in a strip shape, the + side of the same power supply is connected to the electrode plate of the electrolytic degreasing tank, and the - side is connected to the electrode of the electrolytic polishing tank. The same current is supplied to the object through each electrolytic solution by connecting each to the plate and simultaneously performing electrolytic degreasing using the object to be treated as a cathode and electrolytic polishing using the object to be treated as an anode. This problem is solved by the continuous plating power supply method of the present invention, which is characterized by the following.

[Effect]

Since power can be supplied in a non-contact manner via the electrolytic solution without bringing the power supply roller into contact with the workpiece, large current electrolytic treatment is possible, and good plating pretreatment can be performed at high speed.

This power supply mutually utilizes the electrolytic treatment tanks required for pre-treatment of plating, so there is no need to provide a separate power supply tank for power supply. Since it is used in common for the two electrolytic treatments, it also has the effect of reducing power consumption.

62A- 〔Example〕 The present invention will be explained in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic top view of a continuous plating apparatus used to carry out the method of the present invention.

In the figure, reference numeral 1 denotes a continuous object to be treated, which is subjected to predetermined partial plating while passing from left to right through a plating apparatus consisting of a plurality of treatment tanks arranged in a row.

2 is an electrolytic degreasing tank, and 3 is an electrolytic polishing tank. Usually, a pickling tank 4, a chemical polishing tank 5, etc. are arranged between the two tanks, and the workpiece 1 is continuously coated with a plurality of types of chemicals in a predetermined order. The treated object, which has been continuously treated and cleaned and activated, passes through the subsequent Ni mist strike 7, a Ni base plating tank, an Au partial plating tank, etc. (not shown), and is partially plated.

The electrolytic degreasing tank 2 is filled with a predetermined electrolytic degreasing liquid 21 containing, for example, caustic soda as a main component, and electrode plates 22 of non-reactive metal are placed on both sides of the object 1 by immersing it in the electrolytic degreasing liquid 21. are placed facing each other.

Further, in the electrolytic polishing tank 3, electrode plates 32 made of a non-reactive metal are disposed on both sides of the object 1 to be electrolytically soaked in, for example, phosphoric acid. And the electrode plate 22.3 of both treatment tanks
2 is connected to the + side and one side of the power source 8, respectively. When a predetermined power is supplied from the power source 8, in the electrolytic degreasing tank 2, a current flows from the electrode plate 22 to the workpiece 1 through the electrolytic degreasing liquid 21, and at this time, a cathode reaction occurs on the surface of the workpiece 1, and hydrogen gas is generated. occurs and degreases the surface. The current flowing into the workpiece 1 is conducted inside and reaches the electrolytic polishing tank 3, where the workpiece 1 becomes an anode and the current flows into the electrolytic polishing liquid 21. An anodic reaction such as dissolution of the protrusions on the surface of 1 occurs, and the surface becomes smooth. The current then flows back to the power source 8 through the electrode plate 32.

By appropriately determining the length of each treatment tank and the composition of the electrolyte, it is possible to perform electrolytic degreasing and electrolytic polishing of the object to be treated using the same current from a common power source. By supplying current through contact, it is possible to significantly increase the upper limit of current capacity, which is limited in the contact power supply method.

This type of power supply method is most effective when applied to electrolytic treatment in the plating pretreatment process, where the current flowing into and out of the object is large (and does not require strict current value control). Although we have described an example of a combination of electrolytic degreasing and electrolytic polishing, it is of course also possible to use plating instead of electrolytic degreasing as cathode treatment and combine it with electrolytic polishing in the previous process to supply power from a common power source without contact. It is.

〔Effect of the invention〕

As described above, according to the method of the present invention, in the electrolytic treatment required as a pre-treatment for continuous plating, a continuous strip of the treated object is passed through two electrolytic treatment tanks with opposite electrolysis to each other. By using the flow of current into and out of one object during electrolytic treatment to power the other electrolytic treatment, contact power supply to the object to be treated is no longer necessary, enabling high-current electrolytic treatment without trouble, and improving the efficiency of continuous plating. It is remarkable that it contributes to the

[Brief explanation of drawings]

FIG. 1 is a schematic top view of a continuous plating apparatus used to carry out the method of the present invention, and FIG. 2 is a diagram showing a conventional power supply method. In the figure, 1 - strip-shaped object to be treated, 2 - electrolytic degreasing tank, 21 -
Electrolytic degreasing liquid, 22-electrode plate, 3-electrolytic polishing tank,
31-electrolytic polishing liquid, 32-.-electrode plate,
8-Power supply. 0

Claims (1)

[Claims] When performing plating pretreatment to continuously plate the objects (1) connected in a strip shape, the + side of the same power source (8) is connected to the electrode plate (22) of the electrolytic degreasing tank (2), and the - The sides are respectively connected to the electrode plates (32) of the electrolytic polishing tank (3), and electrolytic degreasing treatment using the object to be treated (1) as a cathode and the object to be treated (1) are performed.
) is used as an anode, and an electrolytic polishing process is performed at the same time, thereby supplying the same current to the object to be processed (1) through each electrolytic solution (21, 31).