KR100539239B1 - Plating method for preventing failure due to plating-stop and plating apparatus therefor - Google Patents

Abstract

Provided are a plating method for preventing a defect from occurring due to a plating interruption and a plating apparatus used therefor. In the plating method according to an aspect of the present invention, a plating solution containing tin and bismuth elements is introduced into a plating bath, a plated product is introduced into the plating solution, and then a plating reaction is performed on the plated product to an anode contained in the plating solution. The plating is performed by providing a first applied current to form a tin: bismuth plating layer on the plated product. When the plating is interrupted, a second applied current having a current amount lower than the first applied current is provided to the anode to prevent plating defects from occurring in the plated product during the plating interruption. After the plating stops, the second applied current is converted to the first applied current to continue plating on the plated product.

Description

Plating method for preventing failure due to plating interruption and plating equipment used therefor {Plating method for preventing failure due to plating-stop and plating apparatus therefor}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to plating on integrated circuit devices, and in particular, it is possible to prevent unwanted defects in the plated product being plated due to the interruption of plating due to an error such as a momentary stop. The present invention relates to a plating method of an integrated circuit device and plating equipment used therein.

In the assembling process of an integrated circuit device such as a semiconductor device, a process of plating a lead or the like is performed. The plating process is mainly performed by an electroplating method, and is performed by plating tin on the lead. The plating method employing the electroplating method is disclosed in Korean Patent Application Laid-Open No. 2001-0015412 ("Plating Device and Substitution Precipitation Prevention Method", filed Jul. 22, 2000 by Nippon Denki Co., Ltd., Hisashi Kane). Likewise, it is mainly used to plate alloys on a plated product.

The plating process of the semiconductor device is performed as a mass continuous plating process in accordance with the requirement to assemble the semiconductor device in large quantities. That is, the semiconductor device product, which has been packaged, is continuously suspended by a moving chain belt or the like, and a tin is plated on the lead of the semiconductor device product. At this time, the plating equipment for such a plating process, a plurality of plating baths that are substantially carried out the plating process is arranged in a row, such that the semiconductor device products are continuously passed through the plating bath by the chain belt is a continuous plating process It is configured to be performed.

Plating equipment includes not only plating baths, but also a plurality of baths for pretreatment, such as chemical deflash, rinse, and descale processes in the direction of plating baths. Solution tanks for the activation process and the like are configured in series, and solution baths for rinsing are also provided between the respective solution baths. And, the rear end of the plating bath is provided with a solution bath and a drying unit for the rinse process and the neutralization process. These various solution baths and plating baths are arranged in series, the semiconductor device products are continuously transferred to them by the chain belt, and the entire plating process is performed.

However, when the plating process is performed in a series of continuous processes as described above, the plating process is undesirably stopped due to an error of the plating equipment, and thus the plating is stopped on the product or the lead in which the plating is in progress. May occur. In this case, the transfer of the product or the lead by the chain belt is stopped so that over plating may occur in the products located in the plating baths. Most of the plating equipment adopting the electroplating method in order to prevent the occurrence of such over-plating, the current supply to the anode of the plating bath in case of emergency stop of the plating equipment, that is, the chain belt transfer is stopped. The equipment is configured to stop.

However, the interruption of the current supply may act as a cause of unexpected plating failure. For example, in the case of lead free plating, bismuth Bi is provided in a plating solution provided to a plating bath for plating tin (Sn). However, since Bi has a strong substitution tendency for metal, when the current supply to the anode is stopped, Bi may stick to the lead of the product and the lead that is being plated may be oxidized black. In addition, as the lead of the product positioned between the plating baths is also exposed to the air, a defect due to oxidation occurs.

Substantially, the products placed in the baths during the plating process are about 30 frames based on the lead frame, and these 30 frames are manually recovered and replated due to such unwanted defects. Should be done. This replating process peels off all of the undesired and oxidized portions of the lead, etc., and involves rinsing, replating, and the like, which greatly affects the overall plating yield.

Therefore, even if instantaneous shutdown or failure of the plating equipment occurs, there is a demand for a method that can effectively prevent the occurrence of defects such as unwanted plating or oxidation on the product or lead in which plating is in progress. .

The technical problem to be achieved by the present invention is to effectively prevent the occurrence of undesired plating or oxidation, etc. in the product or the lead in which the plating was in progress, even if the instantaneous shutdown of the plating equipment or the shutdown due to an error occurs. It is to provide a plating method that can be used and the plating equipment used therein.

One aspect of the present invention for achieving the above technical problem, provides a plating method for preventing the occurrence of a failure by the plating interruption.

The plating method includes the steps of introducing a plated product into a plating solution contained in a plating bath, and providing a first applied current to the anode in the plating solution for a plating reaction to the plated product, thereby plating the plated product. And supplying a second applied current of a lower current amount than the first applied current to the anode when the plating is stopped, thereby preventing plating failure from occurring on the plated product during the plating interruption. And converting the second applied current into the first applied current after the plating stop is resolved to continue plating on the plated product.

Here, the second applied current is provided in an amount of current of 5% to 40% compared to the first applied current.

The plating solution contains tin and bismuth elements to form a tin: bismuth plating layer on the plated product by the plating.

One aspect of the present invention for achieving the above technical problem, provides a plating equipment used in the plating method for preventing the failure caused by the plating interruption.

The plating equipment includes a series of a plurality of main plating baths containing a plating liquid, anodes contained in the plating liquids of the main plating baths, auxiliary plating baths that connect the main plating baths and allow the plating liquid to flow. Transfer means for sequentially transferring the plated products to be plated to the main plating baths and the auxiliary plating baths as a cathode corresponding to the anode, and a first application for plating of the plated products to the anode And a power source for selectively switching and supplying a second applied current having a current amount lower than the first applied current to the anode when the plating is stopped.

The plating equipment may further include an auxiliary anode installed in the auxiliary plating bath and connected to the power source so as to correspond to a transfer means as the cathode passing through the auxiliary plating bath. The auxiliary anode may be connected to the power source is connected to the positive electrode connected to the power source.

Alternatively, the anode may be extended into the auxiliary plating bath so as to correspond to the transfer means as a cathode passing through the auxiliary plating bath.

The plating equipment may further include a sensor installed in the auxiliary plating bath to detect the plating liquid flowing into the auxiliary plating bath.

When the power supply is switched from the first applied current to the second applied current, the power supply provides the second applied current with an amount of current that is 5% to 40% of the current amount of the first applied current.

The method of using such plating equipment includes continuously supplying the to-be-plated products to the plating equipment by the conveying means so that the to-be-plated products pass through the main plating baths and the auxiliary plating baths, and from the power source. Performing plating on the plated product by providing a first applied current to the anode for plating reaction to the plated products, and a current amount lower than the first applied current from the power supply when the plating is stopped. Providing a second applied current of the switching to the anode to prevent a plating failure from occurring in the plated product during the plating interruption; and after the plating interruption has been resolved, the second applied current from the power source. It may be configured to include the step of continuing the plating on the plated product by switching to a current applied.

The plating equipment may further include an auxiliary anode installed in the auxiliary plating bath, and the second applied current from the power source may be provided together with the anode in the auxiliary anode. In this case, the first applied current from the power source may be provided to the auxiliary anode together with the anode.

According to the present invention, even if an instant interruption of the plating equipment or an interruption due to an error occurs, it is possible to effectively prevent the occurrence of defects such as unwanted plating or oxidation on the product or lead in which the plating is in progress.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

In embodiments of the present invention, a plurality of plating baths are arranged in series, transferred to a conveying means such as a chain belt, and the instantaneous operation of the equipment due to an error or the like in the plating equipment where the plating is in progress, or the interruption of the transfer of the plated product. When this occurs, it reduces the current that is being provided through the anode to the plating solution of the plating bath but provides a minimum amount of current to effectively prevent unwanted metal substitution reactions from occurring.

In addition, in order to effectively prevent oxidation, etc., on the plated products that are being transferred by the chain belt or the like even if a momentary interruption occurs, at least plating solutions are provided between the plating baths so that the products to be plated can be In order to maintain the immersion state in the plating solution, an auxiliary plating bath may be introduced between the plating baths, and thus the plating equipment may be configured to provide the plating solution to the auxiliary plating baths. In this case, the auxiliary anode is also introduced to the auxiliary plating bath, and it is suggested to allow a minimum current to be provided to the plating liquid through the auxiliary anode to prevent a metal substitution reaction even during a momentary stop or momentary shutdown.

According to this embodiment of the present invention, even if the instantaneous shutdown or the plating interruption of the undesired plating equipment or the transfer chain belt occurs, it is possible to effectively prevent the unwanted metal substitution reaction and oxidation due to exposure of the plated product to the atmosphere. Can be. Accordingly, it is possible to effectively prevent defects such as excessive plating or unwanted metal substitution reactions, oxidation, etc. occurring in the plated product under plating due to undesired plating interruption.

1 is a flowchart schematically illustrating a plating method according to an embodiment of the present invention. 2 to 6b are schematic views for explaining the plating equipment used in the plating method according to an embodiment of the present invention.

Referring to FIG. 1, in the plating method according to the embodiment of the present invention, when the plating process is momentarily interrupted due to an undesired error or the like, excessive plating on the lead of the to-be-plated product, ie, the integrated circuit element, which is being plated in the plating bath is being performed. In order to prevent progression and to prevent the occurrence of unwanted metal substitution phenomenon, the present invention converts the current applied to the plating liquid of the plating bath to a lower amount than the current applied for plating (300 in FIG. 1). ).

For example, in the case of tin-free plating of bismuth plating, when the plating is stopped due to an error in the plating equipment, the current for plating provided to the plated product in the plating bath may be stopped. If the current to be plated is continuously supplied, the plated product, which is conveyed by the conveying means such as the chain belt, is continuously stopped at one position and kept in the plating solution, so that the plating reaction is continuously performed on the plated product. Therefore, the plating layer is plated on the product to be plated over the required thickness. To prevent this, the supply of the applied current provided for plating should be stopped.

However, bismuth (Bi) atoms present in the plating solution at the time of stopping the supply of the applied current for the plating tend to spontaneously substitute and precipitate with other metals. As a result, undesired defects in which Bi is substituted and precipitated may be generated in a plated product or another metal part in a plating bath.

In order to prevent this, in the embodiment of the present invention, when the plating process is momentarily stopped, by converting the first applied current for plating provided to the plating liquid of the plating bath into a relatively low second applied current, the plating process is momentarily interrupted. The second applied current is continuously provided in the plating liquid, i.e., between the plating product (i.e., the negative electrode) and the anode to prevent the substitutional deposition of Bi atoms in the plating liquid for a period of time.

The second applied current should not be a high amount of current sufficient to induce plating, but only if the amount of current sufficient to induce a substitution precipitation of a metal element having a strong tendency for substitution precipitation among the metal elements included in the plating solution, that is, Bi Suffice. For example, if the first applied current for plating is about 75A to 100A, the second applied current to prevent metal substitution precipitation may be about 5A to 30A. That is, the second applied current may be about 5% to 40% of the first applied current. Preferably, the second applied current is preferably provided at about 15A when the first applied current is 75A.

In the plating equipment in which the plating baths are arranged in series and a plurality of various purpose solution baths are arranged before and after the plating baths, the actual production process in which the plated products are sequentially transferred and plated is taken as an example. An example is demonstrated more concretely.

2 and 3 together with FIG. 1, FIG. 2 is a view schematically illustrating a plating apparatus used in a plating method according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. The top view schematically showing the plating bath and the auxiliary plating bath constituting the plating equipment according to the.

Plating equipment, as schematically shown in Figure 2, a plurality of plating baths 300 are arranged in series, a series of solution baths 250 in which various processes are performed before and after such plating baths 300 It is arranged to be configured. Products to be plated, that is, lead frames in which semiconductor elements are packaged into the plating baths 300 and the solution baths 250, are sequentially and continuously transferred by a transfer means such as a chain belt, and the plating baths 300 may be used. Plating is performed at.

The to-be-plated product is hooked on the chain belt at the load part (210) and is fed into the plating equipment. By transfer of the chain belt, the product to be plated is first subjected to a chemical deflash process, followed by a rinse and a high pressure rinse and then descaled. After the rinse, the activating process, that is, immersed in the solution containing the activator (activator), and then pre-dip (pre-dip) process in the pre-treatment solution tank 270. The turn wheel serves to change the conveying direction of the chain belt. After being transferred to the plating baths 300 which have been subjected to the pre-dipping process, the plating is carried out, and after being plated, it is removed from the unload pat 230 through a neutralization process, a hot rinse, an air rinse, and a drying process. do. In this case, the plating process may be substantially performed when the products to be plated pass through the plating baths 300.

Referring to FIG. 3, the plating baths 300 performing the plating step shown in FIG. 2 include main plating baths 310, 320, 330, and 340 and auxiliary plating baths 400 as shown in FIG. 3. It can be configured. The auxiliary plating baths 400 are introduced to penetrate through the connection portion 350 connecting the main plating baths 310, 320, 330, and 340, and thus, between the main plating baths 310, 320, 330, and 340. It also plays a role in allowing the plating liquid to be distributed to the site. That is, in order to allow the to-be-plated products to be transported in the plating liquid suspended from the chain belt 500 to be separated from the plating liquid even in a region between the main plating tanks 310, 320, 330, and 340, to be exposed to the atmosphere. The auxiliary plating baths 400 and the main plating baths 310, 320, 330, and 340 are connected to each other so that the plating solution is also provided to the baths 400. Accordingly, the plating liquids provided to the main plating baths 310, 320, 330, and 340 may flow into the auxiliary plating baths 400.

As described above, after the main plating baths 310, 320, 330, and 340 and the auxiliary plating baths 400 are introduced (110 in FIG. 1), the plating products are continuously transferred to perform plating (FIG. 1). 120). At this time, for plating reaction, a current is applied to the plated product suspended in the anode 700 and the chain belt 500 introduced into the main plating baths 310, 320, 330, and 340 through the power supply 600. do. This applied current is provided by a power source 600 in which a high current of approximately 75 A to 100 A includes a rectifier or the like to induce a plating reaction.

Although FIG. 3 schematically illustrates the application of such a plating current, the plating current is applied to each of the anodes 700 introduced in the form of a flat plate 4 into the main plating baths 310, 320, 330, and 340, respectively. 130 in FIG. 1). Then, the power source 600 is in contact with the chain belt 500 and the to-be-plated product, ie, the lead frame, suspended on the chain belt 500 electrically connected to the chain belt 500 serves as a cathode.

By the plating current applied, the metal elements contained in the plating liquid are plated on the plated product. In the case of lead-free tin plating, the plating liquid contains tin and bismuth elements, and tin and bismuth elements are plated on the plated product at a predetermined rate to form a plating layer by the applied plating current.

However, the plating process may be momentarily stopped or stopped by various kinds of errors during the plating process. Since the conveyance of the chain belt 500 is stopped at such a momentary stop, the plated product is kept in the plating liquid for a while.

In this case, if the plated product continues to be contained in the plating liquid under the plating current supply, excessive plating may occur on the plated product. Since such excessive plating failure should be excluded, when a momentary stop or interruption of this plating process occurs, the power supply 600 stops supplying the plating current, and is plated through the anode 700 and the chain belt 500. The product, ie, the cathode, is provided with a second applied current that is lower than the first applied current, which is the plating current (130 in FIG. 1).

The switching of the power supply from the first applied current to the second applied current is automatically performed by a program set in a control unit (not shown) which controls the plating equipment as a whole, and when a plating interruption occurs momentarily. This second applied current is provided in an amount of current that is approximately 5% to 40% lower than the first applied current. That is, when the first applied current is 75A to 100A, the second applied current is provided at about 5A to about 30A. Preferably, when the first applied current is 75A, the second applied current may be 15A.

Thus, the conversion of the first applied current for plating provided to the plating liquid into a lower second applied current is for achieving two large purposes.

First, in order to prevent the plating reaction from being activated in the plated product staying in the plating solution, the plating reaction is continuously increased to prevent the thickness of the plating layer from being excessively increased. Since the amount of current of the plating current acts as a factor in determining the amount of plating by the plating reaction, it is possible to substantially prevent the plating reaction from proceeding to the plated product by reducing the amount of current.

Secondly, in the case where lead-free tin plating contains a metal element having a strong substitution tendency with respect to a metal such as bismuth in the plating solution, when the supply of the first applied current is stopped, such bismuth valence anode 700 or plated Substitution may be precipitated in the product. This is an undesired phenomenon in the plating process and can be understood as a defect. However, when the second applied current, which is lower than the first applied current provided by the amount of current required for plating, is provided through the anode 700 or the like as in the embodiment of the present invention, such substitutional precipitation of bismuth atoms is prevented.

However, as shown in FIG. 3, the anode 700 installed in the main plating baths 310, 320, 330, and 340 is not extended to the auxiliary plating baths 400. Therefore, some of the plating products located at the auxiliary plating baths 400, that is, at the connection portion 350 between the main plating baths 310, 320, 330, and 340 in the state in which the plating process is stopped may be somewhat desired. May occur. For example, when using a Sn: Bi plating solution, the composition ratio of Sn: Bi of the plating layer may vary. This is an undesirable phenomenon in terms of the properties of the plating layer.

Therefore, in order to prevent such variation in the composition of the plating layer, as shown in FIGS. 4, 5A, and 5B, the auxiliary anode 750 in the form of a flat plate is introduced into the auxiliary plating bath 400. 4 is a plan view schematically illustrating an electrode state installed in the main plating baths 310, 320, 330, and 340 and the auxiliary plating bath 400 constituting the plating equipment according to an exemplary embodiment of the present invention. 5A is a cross-sectional view schematically illustrating a current application state in the main plating baths 310, 320, 330, and 340 according to an embodiment of the present invention, and FIG. 5B is an auxiliary plating according to an embodiment of the present invention. It is sectional drawing shown schematically in order to demonstrate the electric current application state in the tank 400. As shown in FIG.

Referring to FIG. 4, for example, the auxiliary plating bath 400 is introduced through the connection part 350 to connect the first main plating bath 310 and the second main plating bath 320. Since the area of the first main plating bath 310 is substantially up to the plating liquid film 311 introduced into the first main plating tank 310, the plating liquid provided in the first main plating tank 310 is such a plating solution film 311. It becomes the state contained in). This plating liquid film 311 allows a drain (not shown) for discharging the plating liquid to be installed in the outer space thereof.

Therefore, the auxiliary plating bath 400 is introduced into a substantial area of the first main plating bath 310, that is, the area containing the plating liquid, so that the plating liquid contained in the first main plating tank 310 is filled in the auxiliary plating bath 400. Allow to flow into). Accordingly, as shown in FIGS. 5A and 5B, when an instantaneous interruption of the plating process such as the transfer of the chain belt 500 occurs, the plated product 550 positioned in the auxiliary plating bath 400 and stopped at the position is shown. The silver is maintained in a state submerged in the plating liquid 390 flowing in the auxiliary plating bath 400.

At this time, the auxiliary anode 750 is introduced into the auxiliary plating bath 400. The auxiliary anode 750 may be introduced in the form of a flat plate having a length comparable to the length of the auxiliary plating bath 400. The auxiliary anode 750 is introduced to prevent a defect in which a metal element having strong metal substitution precipitation characteristics, such as a bismuth element, from sticking to the plated product 550 to be stopped in the auxiliary plating bath 400 occurs. Therefore, the auxiliary anode 750 may be connected to the power supply 600 through a common connection with the main anode 700 introduced into the first main plating tank 310 or the like. Accordingly, when the plating process is momentarily stopped or stopped, a second applied current is provided to the auxiliary anode 750 together with the main anode 700 to prevent substitution precipitation of metal elements.

Of course, the main anode 700 may be extended to the length of the auxiliary plating tank 400, the auxiliary plating tank 400 is extended so that the main anode 700 may serve as the auxiliary anode 750. .

As described above, by introducing the auxiliary anode 750 into the auxiliary plating bath 400, substitutional precipitation of bismuth elements is prevented, thereby effectively preventing the composition ratio of the plating layer of the plated product due to the plating interruption.

Meanwhile, as the plating solution 390 flows in the auxiliary plating bath 400 as shown in FIG. 5B, the plated product 550 is continuously locked in the plating solution 390 during the serial plating process shown in FIG. 2. Can be transported. Therefore, even when the plating is interrupted, there is no possibility that the plated product 550 is exposed to the atmosphere. Therefore, the defect that the plated product 550 being plated is exposed to the air and oxidized can be effectively prevented.

Furthermore, the introduction of the auxiliary plating bath 400 eventually leads, for example, by connecting four mutually separated main plating baths 310, 320, 330, 340 to each other so that the plating liquid 390 can be distributed. It is possible to implement a plating effect equivalent to the introduction of a large plating bath 300. That is, the uniformity of plating can be improved more.

If the auxiliary plating bath 400 is not introduced, the plating is interrupted between the main plating baths 310, 320, 330, and 340, but the plating process is introduced when the auxiliary plating bath 400 is introduced. In this uninterrupted normal state, the first application current, which is the plating current, may be provided through the auxiliary anode 750, so that the plated product 550 may continue the plating reaction during the transfer. This means that the main plating baths 310, 320, 330, and 340 may be separated from each other due to the characteristics of the facility, thereby overcoming the disadvantages that occurred.

In fact, the individual main plating baths 310, 320, 330, 340 are very long, about 1.5M so that the length of the entire plating bath 300 is 6M or more. It is practically very difficult to construct this as a single plating bath. However, by introducing the auxiliary plating bath 400, the plating effect equivalent to the introduction of the actual single plating bath can also be realized as the separated main plating baths 310, 320, 330, and 340.

On the other hand, the auxiliary plating bath 400 may be configured as shown in Figures 6a and 6b. 6A and 6B are a perspective view and a side view schematically illustrating the auxiliary plating bath constituting the plating equipment according to an embodiment of the present invention.

6A and 6B, the auxiliary plating bath 400 may be configured in a form in which two walls 410 in the form of a plate stand on the bottom plate 420. A leg 430 for supporting may be attached to the bottom plate 420, and two standing walls 410 may be supported on the bottom plate 420 by the support part 460. A hole 440 is introduced into one wall 410, and a sensor 470 that detects the presence of a plating solution is introduced into the hole 440. Detection of such a plating liquid is essential for proper supply of the plating liquid.

The length of the wall 410 of this auxiliary plating bath 400 is, when introduced between the auxiliary plating bath 410 and the main plating baths 310 and 320, as shown in FIG. The bath 410 should have a length to at least reach the plating liquids contained in the main plating baths 310 and 320. That is, it is preferable that the wall 410 of the auxiliary plating bath 400 is configured to a length sufficient to allow the auxiliary plating bath 400 to be introduced such that the plating liquid film passes through or abuts (311 in FIG. 4). .

Referring to FIG. 1 again, when the instantaneous interruption or stop of the plating is resolved, the plating process may be performed by converting the second applied current into the first applied current, which is the plating current, and supplying it to the main anode 700 or the auxiliary anode 750. Continue again (140 in FIG. 1). In such a case, as described above, plating failures such as excessive plating, metal substitution, or oxidation can be effectively prevented in the plated product during the instantaneous interruption or stop of the plating. There is no need to rework the products. In fact, even when the plating was interrupted for about 2 minutes, no plating failure occurred on the plated product. Therefore, the increase in the yield of the plating process and the operation rate of the plating equipment can be greatly improved.

As mentioned above, although this invention was demonstrated in detail through the specific Example, this invention is not limited to this, It is clear that the deformation | transformation and improvement are possible by the person of ordinary skill in the art within the technical idea of this invention.

According to the present invention described above, even if the plating process is temporarily stopped or stopped due to an error or the like, it is possible to effectively prevent the plating defects from occurring in the plated product, for example, the lead frame, which is being plated. Accordingly, the demand for reprocessing work can be reduced, thereby increasing the production rate and facility utilization rate.

1 is a flowchart schematically illustrating a plating method according to an embodiment of the present invention.

2 is a view schematically showing a plating equipment used in the plating method according to an embodiment of the present invention.

3 is a plan view schematically illustrating the main plating bath and the auxiliary plating bath constituting the plating equipment according to the embodiment of the present invention.

4 is a plan view schematically illustrating an electrode state installed in a main plating bath and an auxiliary plating bath constituting a plating apparatus according to an exemplary embodiment of the present invention.

5A is a cross-sectional view schematically illustrating a current application state in the main plating bath constituting the plating equipment according to the embodiment of the present invention.

5B is a cross-sectional view schematically illustrating a current application state in an auxiliary plating bath constituting the plating equipment according to the embodiment of the present invention.

6a and 6b are a perspective view and a side view schematically showing the shape of the auxiliary plating bath constituting the plating equipment according to an embodiment of the present invention.

* Summary of Drawing Reference Symbols *

310, 320, 330, 340: main plating bath, 400: auxiliary plating bath,

500: chain belt, 600: power,

700; Primary anode, 750: Secondary anode.

Claims (14)

delete delete Introducing a plating liquid containing tin and bismuth elements into the plating bath; Introducing a plated product into the plating liquid; Providing a first applied current for a plating reaction to the plated product to an anode contained in the plating solution, thereby performing plating to form a tin: bismuth plating layer on the plated product; Providing switching of the second applied current with a current amount lower than the first applied current to the anode when the plating is stopped to prevent a plating failure from occurring in the plated product during the plating interruption; And And converting the second applied current into the first applied current after the stopping of the plating is stopped to continue plating on the plated product. A plurality of main plating baths containing a plating liquid; Anodes contained in the plating liquid of the main plating baths; Auxiliary plating baths connected between the main plating baths and through which the plating liquid may flow; Transfer means for sequentially transferring the plated products to be plated to the main plating baths and the auxiliary plating baths as a cathode corresponding to the anode; And And a power supply for selectively switching and supplying a first applied current to the anode for plating the products to be plated, and a second applied current having a current amount lower than the first applied current to the anode when the plating is stopped. Plating equipment characterized in that. The method of claim 4, wherein And an auxiliary anode installed in the auxiliary plating bath and connected to the power source so as to correspond to a transfer means as the cathode passing through the auxiliary plating bath. The method of claim 5, And the auxiliary anode is connected to the power supply connected to the anode connected to the power supply. The method of claim 4, wherein Plating equipment characterized in that the anode extends into the auxiliary plating bath corresponding to the conveying means as a cathode passing through the auxiliary plating bath. The method of claim 4, wherein Plating equipment further comprises a sensor installed in the auxiliary plating bath for detecting the plating liquid flowing into the auxiliary plating bath. The method of claim 4, wherein And the power supply provides the second applied current with an amount of current that is 5% to 40% greater than the current amount of the first applied current when the power supply is switched from the first applied current to the second applied current. A series of main plating baths containing the plating liquid, Anodes contained in the plating liquid of the main plating baths; Auxiliary plating baths connected between the main plating baths and through which the plating liquid may flow; Transfer means for sequentially transferring the plated products to be plated to the main plating baths and the auxiliary plating baths as a cathode corresponding to the anode; Plating equipment including a power supply for applying a current to the anode Continuously supplying the to-be-plated products to the conveying means so that the to-be-plated products pass through the main plating baths and the auxiliary plating baths; Plating the plated product by providing a first applied current to the anode from the power source for the plating reaction of the plated products; Providing switching of the second applied current of the current amount lower than the first applied current from the power supply to the anode when the plating is stopped to prevent a plating failure from occurring in the plated product during the plating stop; And And converting the second applied current from the power source into the first applied current after the plating stops are resolved, thereby continuing plating on the plated product. The method of claim 10, And the plating solution contains tin and bismuth elements to form a tin: bismuth plating layer on the plated product by the plating. The method of claim 10, The second applied current is a plating method, characterized in that provided in the amount of current of 5% to 40% compared to the first applied current. The method of claim 10, And the plating equipment further comprises an auxiliary anode installed in the auxiliary plating bath, wherein the second applied current from the power source is provided together with the anode to the auxiliary anode. The method of claim 13, And the plating equipment further comprises an auxiliary anode installed in the auxiliary plating bath, wherein the first applied current from the power source is provided together with the anode to the auxiliary anode.