KR20140047418A - Metal plating device - Google Patents

Abstract

The present invention relates to a metal plating device which is provided to use a pulse rectifier to plate a workpiece with metal and which comprises: a plating cell having electrodes on both sided thereof; a membrane for partitioning the plating cell into an electrolyzing chamber in which an electrolyte is contained and a plating chamber in which a plating solution is contained; and the pulse rectifier which alternately applies positive (+) and negative (-) charges. [Reference numerals] (130) Pulse rectifier

Description

[0001] The present invention relates to a metal plating apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a metal plating apparatus which is configured to perform metal plating on an object to be plated using a pulse rectifier.

In general, in forming a metal plating film for imparting a decorative effect and conductivity to a plating object, a metal plating film is formed by electroless plating, or electroless plating is performed on the surface of the insulating material, A metal plating film was formed, and a pattern to be formed on the surface of the metal plating film was etched to form a metal plating film.

However, this method has a disadvantage in that the working process is complicated and the electroless plating is formed on the surface of the insulating material, the insulating material may be deformed due to a high liquid temperature in the plating bath, and the cost is low and the cost is low.

However, the conventional electroplating apparatus has a complicated mechanical structure and a large number of restricting conditions of the solution used therein. In addition, the electroplating apparatus (electroplating apparatus) There was a restriction on the object to be plated.

In addition, there is a problem that the thickness of the plating varies greatly depending on the position in the solution of the object to be plated, and there is a high risk of occurrence of pits, whiskers, etc. after reflow of the plated metal.

In addition, when the circuit is not connected, such as a PCB substrate, a circuit substrate, and a wafer, plating is difficult due to electrolytic plating, and there is a restriction that plating should be performed by a deposition method such as PVD and CVD or electroless plating.

Open Patent Publication No. 10-2011-0048737 (published May 12, 2011)

(+) Pole and (-) pole are alternately applied to an electrolysis chamber using a pulse rectifier to uniformly coat the entire surface of the object to be plated contained in the plating chamber, And to provide a metal plating apparatus capable of plating electronic substrates by applying an electric force.

According to an aspect of the present invention, there is provided a metal plating apparatus comprising: a plating cell having electrodes on both sides thereof; and a membrane for dividing the plating cell into an electrolysis chamber containing an electrolytic solution and a plating chamber containing a plating solution, And further includes a pulse rectifier for alternately applying positive (+) and negative (-) poles to the electrodes.

According to the present invention, by alternately applying the (+) electrode and the (-) electrode to the electrolytic chamber using the pulse rectifier, the entire surface of the object to be plated contained in the plating chamber can be uniformly plated.

Particularly, it is possible to form the electrodes to be thicker from the center toward both sides, or to reduce the variation in the thickness of the plating by further adding a conductor between the electrodes and the object to be plated.

Also, by adjusting the pulse time, the reverse time, the off time, and the current amount of the pulse rectifier appropriately, the metal structure on the surface during plating can be made small and dense to prevent pits and whiskers.

In addition, since circuits such as PCB substrate, circuit substrate, and wafer are not connected, the electronic substrate to be plated by vapor deposition and electroless plating can be subjected to metal plating by an electric force.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of a metal plating apparatus according to an embodiment of the present invention; FIG.
Fig. 2 is a view showing a current application method of the pulse rectifier in Fig. 1; Fig.
FIG. 3 is an experimental table of FIG. 1 in which on-time, reverse-time, off-time, and current amounts are different from each other.
Figure 4 is a SEM image of the surface of the plated substrates according to the plating method of Figure 3;
5 is a SEM photograph of a surface of a metal-plated substrate by a conventional electroplating method.
6 is a SEM image of a surface of a substrate plated by a plating method according to an embodiment of the present invention.
FIG. 7 is a view showing the flow of electrons and the flow of metal ions in the pulse and reverse states, in FIG. 6; FIG.
8 is a view showing an electric force line of electrodes acting on a plating object in Fig. 1; Fig.
9 to 11 are views showing lines of electric force of metal plating apparatuses and electrodes that act on a plating object according to another embodiment of the present invention.
FIG. 12 is a table comparing the uniformity of the thickness of the plating in the case of plating with a conventional constant current type metal plating apparatus and the case of plating with the metal plating apparatus of the present invention and the embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a view illustrating a metal plating apparatus according to an embodiment of the present invention.

1, the metal plating apparatus 100 is a device for forming a metal plating film on the object to be plated 10 for the purpose of imparting decorative effect and conductivity to the object 10 to be plated, A membrane 120, and a pulse rectifier 130.

Electrodes 140 are formed on both sides of the plating cell 110. The electrolytic chamber 111 containing the electrolytic solution 20 by the membrane 120 and the plating chamber 112 containing the plating solution 30 are partitioned do. Therefore, when the plating object 10 is inserted into the plating liquid 30 of the plating chamber 112 and power is supplied to both electrodes 140, the metal ions in the plating liquid 30 are reduced and the plating object 10 is plated do. At this time, the electrodes 140 may include at least one of a metal ion dissolution electrode capable of dissolving metal ions and an insoluble electrode simply supplying only electrons.

The shape of the plating cell 110 is not limited to the illustrated example, and may vary depending on the shape and surface condition of the object 10 to be plated.

The membrane 120 has an air gap enough to pass only electrons and prevent mixing of the aqueous solution and the electrolytic solution 20. The membrane 120 has an electrolytic chamber 111 provided inside the plating cell 110 and containing the electrolytic solution 20, And a plating chamber 112 containing a plating liquid 30. Therefore, when power is supplied to both the electrodes 140, the electrons e pass through the membrane 120 and move toward the negative electrode.

Here, it is preferable that the membrane 120 is formed to have two electrolysis chambers 111 on both sides and one plating chamber 112 in the center in the plating cell 110, It depends on the needs of the person.

The electrodes 140 further include a pulse rectifier for alternately applying positive and negative poles to the electrodes 140. As described above, the positive rectifier and the negative electrode are alternately applied to the respective electrolytic chambers 111 by the pulse rectifier 130 so that the entire surface of the object to be plated 10 contained in the plating chamber 112 is filled with the plating liquid (30).

On the other hand, the plating liquid 30 may be formed of an electroless plating solution. The electroless plating solution is a method of autocatalytically reducing the metal to be deposited on the surface of the object to be plated 10 without being supplied with electric energy from the outside, and it is applicable to various objects 10 to be plated such as plastic or organic as well as conductor There are advantages to be able to.

Fig. 2 is a diagram showing a current application method of the pulse rectifier in Fig.

As shown in FIG. 2, the pulse rectifier 130 is a device for rapidly changing the current to the (+) and (-) poles and supplies the current application time of the pulse rectifier 130 to the pulse time ), And the reverse current application time is referred to as a reverse time. The amount of current flowing in the pulse time is referred to as Ep and the amount of current flowing in the reverse time is referred to as Er.

Here, if plating is performed by appropriately adjusting the pulse time, the reverse time and the amount of current, not only the entire surface of the object 10 to be plated can be uniformly coated but also the front surface or the back surface can be plated separately. For example, increasing the Ep and increasing the pulse time may increase the plating thickness on the entire surface of the object to be plated 10, while increasing Er and increasing the reverse time may increase the thickness of the plating on the rear surface of the object 10 do.

FIG. 3 is an experimental table of FIG. 1 in which pulse time, reverse time, off time, and current amount are different from each other. 4 is a SEM image of the surface of the plated substrates according to the plating method of FIG.

As shown in FIG. 3 and FIG. 4, when the samples 1 to 5 are compared, it can be confirmed that the current is weak and the metal structure is small and dense at the time of plating as the off time is longer. In addition, the shorter the period of the pulse rectifier 130, that is, the shorter the combined time of Pulse Time, Reverse Time, and Off-Time, the smaller and denser the metal structure during plating. You can see that.

5 is a SEM image of a surface of a metal-plated substrate by a conventional metal plating method. 6 is a SEM photograph of a surface of a substrate plated by a plating method according to an embodiment of the present invention. FIG. 7 is a view showing the flow of electrons and the flow of metal ions in the pulse and reverse states in FIG.

As shown in FIG. 5, when the plating is performed by a conventional plating method (Semi-Electro plating), it is difficult to prevent pits and whiskers due to the large growth of the structure. The pulse rectifier 130 is used According to the present invention, as shown in Fig. 6, the metal structure on the surface during plating is small and dense to prevent pits and whiskers.

As shown in FIG. 7, since the present invention supplies electrons using the pulse rectifier 130, when a tissue grown in a pulse state becomes a reverse state, tissues grown in a pulsed state and tissues close to the cathode are faster than other metal tissues As it melts, the metal crystals on the surface are finely divided to form a small, dense structure.

Fig. 8 is a view showing an electric force line of electrodes acting on the object to be plated in Fig. 1; 9 to 11 are views showing electric force lines of the metal plating apparatuses according to another embodiment of the present invention and electrodes acting on the object to be plated.

As shown in FIG. 8, when the electrodes 140 are formed in a straight line, the electric force lines are pushed to the center of the object to be plated 10 The plating thickness at the center becomes thicker than both sides.

To solve this problem, it is possible to change the configuration of the metal plating apparatus 100 as follows. In the present embodiment, the differences from the above-described embodiment will be mainly described.

[ Example  1] Shape change of electrodes

As shown in FIG. 9, the metal plating apparatus 200 can be formed such that the thickness of the electrodes 240 increases from the center toward both sides. When both sides of the electrodes 240 are thicker than the center, the electrodes 240 on both sides where the thickness of the plating liquid 30 is thin are positioned close to the object to be plated 10, It becomes possible to perform plating with a uniform thickness.

[ Example  2] Addition of conductors

As shown in FIG. 10, a conductor 310 may further be provided between the electrodes 340 of the metal plating apparatus 300 and the object to be plated 10. The conductor 310 is a material that allows a current to flow more easily in the plating chamber 112. When the conductor 310 is positioned on both sides of the object 10 to be plated, the electric force lines do not reach the center of the object 10 to be plated, The electric force lines can uniformly be distributed to the object to be plated while spreading evenly.

Therefore, it is possible to uniformly coat the entire surfaces of the object 10 without forming the electrodes 340 to be thicker from the center toward both sides.

In addition, even when circuits are not connected to each other, such as a PCB substrate, a circuit board, and a wafer, an electric force can be applied to metal plating, and metal coating can be formed at a higher rate than electroless plating.

[ Example  3] Change of position of conductor

As shown in FIG. 11, the metal plating apparatus 400 may extend the conductor 410 by the length of the electrodes 440 on both sides in the longitudinal direction of the object to be plated 10. Therefore, plating can be performed even on the side where the plating is not performed even with other surfaces.

Here, it is most preferable that the position of the conductor 410 is located near the portion where the plating liquid is hardly coated, thereby reducing the unplated portion, and the position may be changed according to the needs of the practitioner.

 FIG. 12 is a table comparing the uniformity of the thickness of the plating in the case of plating with a metal plating apparatus of the conventional constant current type and the case of plating with the metal plating apparatus of the present invention and the embodiments.

In this experiment, immersion TIN plating solution and 20% electrolytic solution were used in a 18 cm × 19 cm × 60 cm square plating cell, and a current of 1A was applied for 20 minutes. The pulse rectifier changed the electrode every 2 seconds. In addition, an insoluble electrode of a Pt / Ti network type was used as the electrode, and the temperature of the plating liquid was set at 70 degrees.

As shown in FIG. 12, in the case of the plating method of the conventional constant current type, there is a disadvantage that the thickness of the plating is high, but the deviation of the thickness of the plating is large. However, in order to solve this problem, it is confirmed that the thickness variation is reduced to 0.037 when the currents are changed to pulse form as in the present invention. In addition, when plating was performed in Examples 1 to 3, it was confirmed that the thickness of the plating was thicker than that of the plating of the present invention, and the deviation of the plating thickness was reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation and that those skilled in the art will recognize that various modifications and equivalent arrangements may be made therein. It will be possible. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

10 .. Plating object 20 .. electrolyte
30 .. Plating solution 110 .. Plating cell
111 .. electrolytic chamber 112 .. plated chamber
120 .. Membrane 130 .. Pulse rectifier
140, 240, 340, 440. Electrodes 310, 410.

Claims (5)

A plating cell having electrodes formed on both sides thereof,
An electroplating apparatus including an electrolytic chamber containing an electrolytic solution and a membrane separating the electrolytic chamber containing the electrolytic solution and a plating chamber containing a plating solution,
And a pulse rectifier for alternately applying a positive electrode and a negative electrode to the electrodes. The method of claim 1,
Wherein the electrodes are formed to be thicker from the center toward both sides. The method of claim 1,
And a conductor between the electrodes and the plating object. The method of claim 1,
Wherein the plating solution is an electroless plating solution. The method of claim 1,
Wherein the electrodes comprise at least one of a metal ion dissolution electrode and an insoluble electrode.

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