KR20110027585A - Electroplating apparatus and electroplating method - Google Patents

Abstract

PURPOSE: An electroplating apparatus and method are provided to prevent the reduction of coating quality without frequent changes of a filter by controlling the dissolved oxygen concentration of plating liquid. CONSTITUTION: An electroplating apparatus(11) comprises a plating bath(13) which stores plating liquid, a separate bath(15) which is separated from the plating bath, and a return pipe(41) which returns the plating liquid from the separate tub to the plating tub. The separate bath comprises a first space(17) and a second space(19) which are divided by a partition wall(21) extended in the vertical direction. The extra plating liquid of the first space over the specific level is delivered to the second space.

Description

[0001] ELECTROPLATING APPARATUS AND ELECTROPLATING METHOD [0002]

The present invention relates to an electroplating apparatus and an electroplating method.

Electroplating is used, for example, for the purpose of forming a wiring pattern on a printed board. For example, in the case of copper sulfate electroplating, in order to obtain coating performance for purposes such as gloss, film physical property, throwing power, and hole filling property, a plating solution is added to a plating solution such as a brightener, a carrier, a leveler Various additives such as a promoter and a suppressing agent are added.

These additives effectively inhibit the surface of the substrate and accelerating agents act effectively in the through hole or the via hole, thereby promoting uniform electrodeposition to the through hole and filling of the hole in the via hole. However, if the accelerator is excessively contained in the plating liquid, the effect of inhibiting the growth of the active nucleus by the inhibitor is lowered, so that a dense coating is not obtained and the physical properties of the coating are deteriorated. In addition, the deposition inhibiting effect on the surface of the substrate is lowered, so that the uniform electrodeposition of the through hole is deteriorated, and the hole filling property of the via hole is deteriorated. On the other hand, if the promoter is insufficient in the plating solution, the effect of promoting the generation of active nuclei is lowered, and a dense coating is not obtained, and the physical properties of the coating are deteriorated. Further, the promoting effect into the through hole or the via hole becomes insufficient, so that the uniform electrodeposition property of the through hole is deteriorated, and the hole filling property of the via hole is deteriorated. Therefore, it is important that various additives in the plating liquid are added in appropriate balance.

It is also known that the concentration of dissolved oxygen in the plating solution is one of the factors affecting the coating performance of electroplating. The reason is explained as an example in which bis (3-sulfopropyl) disulfide (SPS), which is a general polishing agent for electroplating copper sulfate, is used. In other words, during the plating process, the following series of redox reactions are taking place. On the surface of the cathode, SPS is reduced to 3-mercaptopropane-1-sulfonic acid (MPS). SPS acts as an accelerator by reducing copper ions when two MPSs in the vicinity of the cathode return to one SPS. MPS that is not related to this reaction is oxidized by dissolved oxygen and returned to the SPS. However, when the dissolved oxygen is out of the MPS in conjunction with Cu ⁺ goes accumulated as Cu ⁺ -MPS. When Cu ^& lt ^{; + &} gt ^; -MPS is accumulated, the concentration of the brightener becomes excessive, and the desired coating performance is not sufficiently obtained. If the oxygen concentration is excessive, the amount of MPS oxidized by oxygen increases and the amount of MPS that reduces copper ions decreases, so that the promoting effect becomes insufficient. Therefore, the intended coating performance is not sufficiently obtained.

In this way, it is necessary to adjust the dissolved oxygen concentration in the plating solution to an appropriate range. However, when a soluble anode is used as the anode, dissolved oxygen is consumed due to dissolution of the metal copper or the like and the dissolved oxygen concentration in the plating solution tends to be lowered, When the anode is used, oxygen is generated from the anode, so that the concentration of dissolved oxygen in the plating solution tends to be high. Thus, various techniques for adjusting the dissolved oxygen concentration in the plating solution to a predetermined range have been proposed.

For example, Japanese Patent Application Laid-Open No. 2004-143478 discloses an electroplating apparatus using a soluble anode as an anode. This apparatus has a plating bath in which a plating solution is stored and a separate bath separate from the plating bath, and the plating bath circulates between the plating bath and the separate bath. In this apparatus, air is blown into the plating liquid through an air blowing pipe (separate tube) in the separate bath so that the dissolved oxygen concentration of the plating liquid is maintained at 5 ppm or more, thereby deteriorating the quality of the coating.

Japanese Patent Application Laid-Open No. 2007-169700 discloses an electroplating method using an insoluble anode as an anode. According to this method, the plating solution is agitated by air or an inert gas in the plating bath to maintain the dissolved oxygen concentration of the plating solution at 30 mg / liter or less so that the inside of the through hole in the plating object can be stably charged for a long period of time.

However, in recent years, wiring, through holes, via holes, and the like in printed circuit boards and the like have become finer, so that the quality required for plating is also increasing. For example, if foreign matter floats in the plating liquid, the foreign matter becomes nuclei, and a nodule (lumpy portion) may be generated in a part of the coating film of the plating. Therefore, a filter for separating the foreign substance in the plating liquid from the plating liquid Is installed. This filter can separate various kinds of foreign substances in the plating solution from the plating solution by filtering the plating solution.

However, when a large amount of metal particles such as copper particles are adhered to the filter, dissolved oxygen in the plating solution may be consumed by the metal particles or additives (for example, sulfur-based additives) contained in the plating solution may be deteriorated. Therefore, it has been necessary to frequently replace the filter in order to suppress deterioration of the coating quality of the plating film.

An object of the present invention is to provide an electroplating apparatus and an electroplating method capable of adjusting the concentration of dissolved oxygen in a plating solution and reducing a cost due to filter exchange.

The electroplating apparatus of the present invention is provided with a plating tank in which a plating liquid is stored and a separate tank in which the plating liquid is circulated between the plating tank and the plating tank as a separate tank from the plating tank. Wherein the separate bath has a first space and a second space located on the downstream side of the first space, and the second space is formed in the first space, And the air flows down in the second space.

1 is a configuration diagram showing an electroplating apparatus according to a first embodiment of the present invention.
2A to 2F each show a modification of the structure of the upper edge portion in the separate tank of the electroplating apparatus.
Figs. 3A to 3E show modified examples of the shape and arrangement state of the transfer-side pipe.
4 is a configuration diagram showing a separate set of the electroplating apparatus according to the second embodiment of the present invention.
Fig. 5 is a configuration diagram showing a separate set of the electroplating apparatus according to the third embodiment of the present invention. Fig.
6 is a configuration diagram showing an electroplating apparatus according to a fourth embodiment of the present invention.
7 is a configuration diagram showing an electroplating apparatus according to a fifth embodiment of the present invention.
Figs. 8A and 8B are diagrams showing a plating bath of an electroplating apparatus according to a sixth embodiment of the present invention. Fig.
9A and 9B are diagrams showing a plating bath of an electroplating apparatus according to a seventh embodiment of the present invention.
10 is a configuration diagram showing an electroplating apparatus according to an eighth embodiment of the present invention.
FIG. 11A is a view showing a first bank of a separate bath of an electroplating apparatus according to a ninth embodiment of the present invention, and FIG. 11B is a sectional view taken along line XIB-XIB in FIG. 11A.
12 is a configuration diagram showing an electroplating apparatus used in Example 1. Fig.
FIG. 13A is a configuration diagram showing an electroplating apparatus used in Embodiment 2, and FIG. 13B is a sectional view taken along the line XIIIB-XIIIB in FIG. 13A.
14 is a configuration diagram showing an electroplating apparatus used in Example 3. Fig.
Figs. 15A and 15B are cross-sectional views for explaining a method of measuring the depression amount of a via hole in Examples 1 and 3;
16 is a plan view showing the shape of a test piece used for measurement of elongation and tensile strength in Examples 1 to 3;
17 is a cross-sectional view for explaining a method of evaluating uniform electrodeposition of through holes in Example 2. Fig.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each of the following embodiments, copper plating is performed on the object to be plated as an example.

≪ First Embodiment >

1, the electroplating apparatus 11 according to the first embodiment of the present invention includes a plating tank 13, a separate tank 15 separate from the plating tank 13, Side piping 29 for transferring the plating solution from the separate tank 15 to the plating tank 13 and a return-side piping 41 for returning the plating solution from the separate tank 15 to the plating tank 13.

The plating tank 13 has a substantially rectangular parallelepiped shaped bath main body 47 with an open upper part and an overflow bath 49 integrally provided with the bath main body 47. An anode 55 is disposed inside the bath main body 47. Further, the bath main body 47 is constituted so as to be able to install a cathode 57 which is an object to be plated.

The anode 55 is disposed on both sides of the cathode 57, respectively. As the anode 55, a soluble anode or an insoluble anode is used. As the soluble anode, for example, a copper plate can be used. As the soluble anode, for example, a spherical copper (copper ball) accommodated in a network container formed of titanium or the like may be used. These copper plates and copper balls are formed by phosphorus-containing copper containing phosphorus, for example. As the insoluble anode, for example, Ti-Pt coated with indium oxide can be used.

Each anode 55 is disposed inside an anode bag 59 through which the plating solution can flow and does not pass the anode slime. The anode bag 59 is made of a material such as polypropylene or polyethylene.

Between the cathode 57 and each anode 55, a nozzle 61 is disposed along the height direction of the cathode 57. Each of the nozzles 61 is provided with a plurality of jetting openings (not shown) for jetting the plating liquid fed from the separate vessel 15 through the return side piping 41 toward the cathode 57 side. The plating liquid around the cathode 57 can be stirred by the jet (jet flow) from the nozzle 61. The stirring of the plating liquid around the cathode 57 may be performed by mechanical stirring by a mechanical stirrer such as a squeegee or a paddle (not shown) in addition to stirring by the above-described sorting. Further, stirring by mechanical stirring and mechanical stirring may be used in combination.

A voltage is applied between the anode 55 and the cathode 57 from a power supply (not shown). As a result, the cathode 57, which is the object to be plated, can be electroplated.

The overflow tank 49 is integrally attached to the side of the bath main body 47. The plating liquid in the bath main body 47 flows into the overflow tank 49 over the upper side edge portion 53 of the side wall 51 of the bath main body 47. In this overflow tank 49, a liquid level sensor (not shown) for detecting the liquid level in the tank may be provided. The liquid level of the overflow tank 49 can be adjusted by controlling the driving or stopping of the pump 63 based on the detection result of the liquid level sensor.

The separate vessel (15) has a substantially rectangular parallelepiped separate vessel body (20) having an open upper part and a first partition (21) dividing the internal space of the separate vessel body (20) into two. The first partition 21 has a substantially rectangular shape and is installed upright from the bottom surface of the separate bath main body 20. The inside of the separate tank 15 by the first partition 21 is divided into a first space 17 and a second space 19 located on the downstream side of the first space 17. 1 and 2A, the first partition 21 has a partition wall body 25 extending upward from the bottom surface of the separate vessel 15 and a partition wall 25 extending from the upper end of the partition wall body 25 to the second space 19) extending in the width direction.

The upper edge 23 of the first partition 21 is set at a predetermined lower height than the upper edge of the separate tank main body 20. That is, the separate tank 15 overflows the upper edge portion 23 of the plating liquid in the first space 17 beyond the predetermined height and flows into the second space 19 from the first space 17 . The first space 17 and the second space 19 are in communication with each other only in a space above the upper edge 23 of the first partition 21. The separate chamber 15 is divided into the first space 17 and the second space 19 so as not to move the plating liquid between the first space 17 and the second space 19 below the upper edge 23, This is a partitioned structure.

The plating liquid flowing into the second space 19 flows in the air in the second space 19. The liquid level of the plating liquid in the second space 19 is lower than the predetermined height of the upper side edge portion 23 of the first partition wall 21 in order to lower the plating liquid in the air in the second space 19. [ Position.

The liquid level of the plating liquid in the second space 19 can be adjusted by controlling the driving or stopping of the pump 64 provided on the return side pipe 41, for example. A liquid level sensor (not shown) for detecting the liquid level in the space may be provided in the second space 19. The level of the liquid level in the second space 19 can be adjusted by controlling the driving or stopping of the pump 64 based on the detection result of the liquid level sensor.

The projecting piece 27 extends from the upper end of the partition wall body 25 toward the second space 19 and has its tip separated from the side surface of the partition wall body 25 on the side of the second space 19. The plating liquid flowing into the second space 19 from the first space 17 is guided along the projecting piece 27 to the leading end thereof and the leading end of the plating liquid is guided from the leading end thereof to the leading end of the projecting piece 27, (27). ≪ / RTI > Since the tip end of the projecting piece 27 is spaced apart from the side surface of the partition main body 25, it is possible to prevent the plating liquid from falling down on the side surface of the partition main body 25. [

Although the first partition 21 has the protruding piece 27 as shown in Fig. 2A in the present embodiment, the protruding piece 27 like the modification shown in Figs. 2B to 2D, Or may have a shape that does not have projecting pieces as in the modification shown in Figs. 2E and 2F.

In the modification of Fig. 2B, the projecting piece 27 extends from the upper end of the partition main body 25 toward the second space 19 and also diagonally upward. 2A, the distal end portion of the projecting piece 27 is spaced apart from the side surface of the partition wall body 25. As shown in Fig. 2A, it is possible to prevent the plating liquid from flowing to the surface of the protruding piece 27 on the side of the second space 19 (the bottom surface of the partition wall 25) ), And tend to drop down.

In the modification of Fig. 2C, the projecting piece 27 extends from the upper end of the partition wall body 25 toward the second space 19 and also extends obliquely downward. 2A, since the tip end of the projecting piece 27 is spaced apart from the side surface of the partition main body 25, it is possible to suppress the downward movement of the plating liquid on the side surface of the partition main body 25 have. Further, since the projecting piece 27 is inclined downwardly, it is possible to substantially prevent the plating liquid from flowing into the lower surface (inner surface) of the projecting piece 27. [ In this respect, the modification of Fig. 2C is preferable to the configuration of Fig. 2A.

2D, the protruded piece 27 has a transverse portion 27a extending in the transverse direction from the upper end of the partition wall body 25 toward the second space 19 side and a second transverse portion 27b extending from the front end of the transverse portion 27a And a vertical portion 27b extending downward. The tip end of the vertical portion 27b is spaced apart from the side surface of the partition main body 25. [ 2A, since the tip end of the projecting piece 27 is spaced apart from the side surface of the partition main body 25, it is possible to suppress the downward movement of the plating liquid on the side surface of the partition main body 25 have.

Further, in this embodiment, the plating liquid flowing into the second space 19 from the first space 17 is guided along the transverse portion 27a to the leading end thereof, and then flows downward along the vertical portion 27b. This front end portion has a large distance from the side surface of the partition main body 25. Therefore, it is possible to substantially prevent the plating liquid from flowing into the inner surface of the projecting piece 27. In this respect, the modification of Fig. 2D is preferable to the configuration of Fig. 2A.

In the modification of Figs. 2E and 2F, the first partition 21 has no projecting piece. In the modification of Fig. 2E, the first bank 21 is arranged along the vertical direction. In the modification of Fig. 2F, the first bank 21 is arranged to be inclined with respect to the vertical direction. The first partition 21 of this modified example is inclined so as to be positioned on the downstream side as it goes downward from above.

The upstream side piping 29 has its upstream end connected to the bottom of the overflow tank 49 and the lower side of the side wall 51 of the bath main body 47. The overflow tank 49 and the bath main body 47 ). A supply port 29a for supplying a plating liquid to the separate tank 15 is formed at the downstream end of the transfer side pipe 29.

As shown in Figs. 1 and 3A, the supply port 29a is located at a higher level than the plating liquid in the first space 17, and is not in contact with the plating liquid. Therefore, the plating liquid discharged from the supply port 29a is downwardly discharged from the supply port 29a and contacts the plating liquid stored in the first space 17 to give a certain impact to the plating liquid. As a result, the plating liquid in the first space 17 flows a little.

As in the modification shown in Figs. 3B to 3E, the supply port 29a of the delivery pipe 29 is located below the predetermined height. That is, the supply port 29a may be located below the liquid level of the plating liquid in the first space 17 and immersed in the plating liquid. In these modified examples, the plating liquid discharged from the supply port 29a is directly supplied into the plating liquid stored in the first space 17. [ 3A, in which the plating liquid once discharged into the air from the supply port 29a drops onto the liquid surface of the plating liquid stored in the first space 17, the impact on the plating liquid in the first space 17 Can be reduced.

3C, the downstream side end portion of the conveying pipe 29 is bent such that the discharge direction of the plating liquid from the supply port 29a faces the inner side surface 20a side of the separate bath main body 20. In this modified example, the flow of the plating liquid stored in the first space 17, particularly, the flow of the plating liquid located on the lower side can be suppressed as compared with the form of FIG. 3B in which the plating liquid is discharged in the downward direction.

In the modified example of Fig. 3D, a plurality of (six in this modified example) end portions on the downstream side of the transfer side pipe 29 are branched, and the transfer side pipe 29 is provided with a plurality of supply ports 29a through which the plating liquid is discharged. . As a result, the discharge speed of the plating liquid discharged from each supply port 29a becomes smaller than that in the modification of Fig. 3B. Therefore, it is possible to suppress the flow of the plating liquid stored in the first space 17, particularly, the flow of the plating liquid located on the lower side.

In the modified example of Fig. 3E, the delivery pipe 29 has a structure in which the inner diameter of the end on the downstream side thereof is larger than that of the other portion. As a result, the discharge speed of the plating liquid discharged from the supply port 29a becomes smaller than that in the modification of Fig. 3B. Therefore, it is possible to suppress the flow of the plating liquid stored in the first space 17, in particular, the flow of the plating liquid located on the lower side.

As shown in Fig. 1, the return-side pipe 41 has its upstream end connected to the side of the separate bath main body 20 and communicates with the second space 19. A plurality of (three in this embodiment) end portions on the downstream side of the return side pipe 41 are branched. Two end portions 41a and 41b of the plurality of pipe end portions are connected to the pair of nozzles 61 and communicate with the nozzles 61, respectively. The other end portion 41c of the plurality of pipe end portions is connected to the bottom of the bath main body 47 and communicates with the inside of the bath main body 47. The end portion 41c is disposed on the side surface of the bath main body 47 on the side opposite to the overflow tank 49.

A filter 65 is attached to the return-side pipe 41 on the upstream side of the branching point. A pump 64 is provided on the return-side pipe 41 on the upstream side of the filter 65. The pump 64 and the pump 63 are driven to circulate the plating liquid between the plating bath 13 and the separate bath 15. The filter 65 is capable of separating various foreign substances in the plating liquid from the plating liquid by filtering the plating liquid.

The volume ratio of the plating bath 13 and the separate bath 15 (volume ratio of the plating bath 13: volume of the separate bath 15) is preferably 0.1: 1 to 30: 1, more preferably Is preferably 0.3: 1 to 10: 1. When the volume of the plating bath 13 is less than 0.1 times the volume of the separate bath 15, the size of the separate bath 15 becomes excessively large, which is not practical. On the other hand, if the volume of the plating bath 13 exceeds 30 times the volume of the separate bath 15, the capability of adjusting the dissolved oxygen in the separate bath 15 may become insufficient.

The circulation amount [turn] is calculated as the circulation rate (liter / minute) × 60 (minute / hour) ÷ total bath amount (liter) and is preferably calculated as the total bath amount (total amount of the plating liquid circulating in the electroplating apparatus) Preferably 5 to 100 turns, and more preferably 10 to 80 turns. When the circulation amount is less than 10 turns, the ability to adjust the dissolved oxygen in the separate tank 15 may become insufficient. On the other hand, if the circulation amount exceeds 100 turns, a large circulation pump or a large number of circulation pumps are required, which is not practical.

As the plating solution, for example, a copper sulfate plating solution or the like is used. This copper sulfate plating solution is a copper sulfate which is a copper source plus a predetermined amount of sulfuric acid. To the copper sulfate plating solution, various additives are added as needed. Examples of the additive include an organic additive such as a brightener, a flatting agent, a promoter called a carrier, or an inhibitor. Examples of the organic additive include a nitrogen-containing organic compound, a sulfur-containing organic compound, and an oxygen-containing organic compound. Specific examples of the sulfur-containing organic compound include sulfur-based compounds selected from the following formulas (1) to (4).

(Wherein R ₁ , R ₂ and R ₃ are each an alkyl group having 1 to 5 carbon atoms, M is a hydrogen atom or an alkali metal, a is an integer of 1 to 8, and b, c and d are each 0 or 1)

As the nitrogen-containing organic compound, known compounds can be used, and examples thereof include tertiary amine compounds and quaternary ammonium compounds. As the oxygen-containing organic compound, known compounds can be used, and examples thereof include polyether compounds such as polyethylene glycol.

Each component of the copper sulfate plating solution may be replenished by adding a replenishing liquid or the like as needed to the amount reduced by electroplating continuously. Thus, electroplating can be continuously performed. In addition, when a soluble anode is used, copper ions can be supplied from the soluble anode. When an insoluble anode is used, a bath capable of separately supplying copper ions may be provided in addition to the plating bath 13, and copper ions may be supplied from this bath to the plating bath.

Next, the operation of the electroplating apparatus 11 of the present embodiment will be described. First, at the time of bathing, the bath main body 47 and the overflow tank 49 of the plating tank 13, and the first space 17 and the second space 19 of the separate tank 15, A predetermined amount of the plating solution is stored.

Subsequently, the pump 63 and the pump 64 are driven to circulate the plating liquid between the plating bath 13 and the separate bath 15. The level of the liquid in the overflow tank 49 and the second space 19 is adjusted by controlling the driving or stopping of the pump 63 and the pump 64. In this state, the cathode 57, which is the object to be plated, is immersed in the plating bath of the bath main body 47 to energize the anode 55 and the cathode 57. As a result, the object to be plated is electroplated. When the plating is completed, the plating is replaced with another plating, and electroplating is sequentially performed.

Next, the flow of the plating liquid will be described. When the pump 64 is driven, the plating liquid is supplied into the bath main body 47 through the return side piping 41. When the plating liquid is supplied to the bath main body 47, the plating liquid of the same amount as the supplied liquid flows into the overflow tank 49 over the upper side edge portion 53 of the side wall 51 of the bath main body 47.

When the pump 63 is driven, the plating liquid in the overflow tank 49 and the bath main body 47 is supplied to the first space 17 of the separate tank 15 through the transfer side pipe 29. Foreign matters such as copper particles or the like which are caused by the drop from the cathode 57 and the slime generated in the soluble anode are floating in the plating liquid. In the first space 17 of the separate bath 15, the copper particles having a density higher than that of the plating solution are precipitated and settled on the bottom of the first space 17.

On the other hand, when the plating liquid is supplied to the first space 17 through the transfer pipe 29, a plating liquid of the same amount as the supplied liquid flows over the upper edge 23 of the first partition 21, . The plating liquid flowing into the second space 19 reaches the liquid level of the plating liquid stored in the second space 19 after the air flows down in the second space 19. Thus, the dissolved oxygen concentration of the plating liquid is adjusted by being exposed to the air while the plating liquid is drained. Specifically, when a soluble anode is used as the anode 55, oxygen in the air is received in the plating liquid at the time of plating, whereby the lowering of the dissolved oxygen concentration of the plating liquid can be suppressed. On the other hand, when the insoluble anode is used as the anode, the concentration of dissolved oxygen in the plating solution can be suppressed by appropriately discharging oxygen from the plating solution to the air during plating.

The dissolved oxygen concentration can be adjusted by changing the time for the plating solution to flow in the air, the surface area in contact with air during the air flow, and the like. The time for the plating liquid to flow down in the air and the surface area of the plating liquid which is in contact with the air during the air flow are set to be equal to the surface area of the plating liquid in the upper edge 23 and the second space 19 of the first bank 21, Or by changing the width of the upper edge portion 23 over which the plating liquid overflows.

The dissolved oxygen concentration of the plating liquid in the bath main body 47 of the plating tank 13 is preferably 4 to 20 mg / liter. If the dissolved oxygen concentration is less than 4 mg / liter or exceeds 20 mg / liter, the quality of the plating may be deteriorated. Concretely, for example, properties of the coating film such as the elongation and tension of the plated film are reduced, the uniform electrodeposition (TP) of the through hole in the printed board is lowered, the hole filling property of the via hole is lowered There is a case.

In the present embodiment, as described above, the plating liquid in the first space 17 overflows and flows into the second space 19, so that air is sucked into the plating liquid by the falling of the plating liquid due to this overflow. Thereby, the dissolved oxygen concentration in the plating liquid can be brought close to the saturated dissolved oxygen concentration. Air is the main component of oxygen (about 20%) and nitrogen (about 80%). In addition, as a target, for example, the saturation dissolved oxygen concentration of water at 25 캜 is about 8.1 mg / liter. When the dissolved oxygen concentration in the plating solution is less than the above preferable range (4 to 20 mg / liter), the plating solution is drained due to the overflow, so that oxygen in the air is dissolved in the plating solution and the dissolved oxygen concentration in the plating solution is close to the saturated dissolved oxygen concentration Loses. This makes it possible to easily adjust the dissolved oxygen concentration in the plating solution to the above preferable range. On the other hand, when the concentration of dissolved oxygen in the plating solution is larger than the above preferable range, a portion of the dissolved oxygen in the plating solution is appropriately discharged into the air due to the influence of nitrogen in the air due to the overflowing of the plating solution, The concentration approaches the saturation dissolved oxygen concentration. This makes it possible to easily adjust the dissolved oxygen concentration in the plating solution to the above preferable range.

The distance (fall) between the upper edge portion 23 of the first partition 21 and the liquid level of the plating liquid in the second space 19 is not particularly limited, but is preferably 10 Cm or more, and more preferably 15 cm or more. Further, it is preferable that the drop height is 100 cm or less so that the size of the separate tank 15 is not excessively increased.

In the present embodiment, one partition wall is provided in the separate tank 15 to overflow the plating liquid only once. However, as described later, by providing a plurality of partitions in the separate tank main body, The number of overflows may be plural. It is preferable that the number of times of overflow in the separate bath 15 is preferably two times or more in that the adjustment efficiency of the dissolved oxygen concentration can be enhanced. It is also preferable that the number of overflows is 5 or less so that the size of the separate tank 15 is not excessively increased.

As described above, in the first embodiment, the excess amount of the plating liquid in the separate bath (15) flows into the second space (19) from the first space (17) And stays in the first space 17. Therefore, the metal particles in the plating liquid staying in the first space 17 can be settled downward in the first space 17. When the metal particles are precipitated below the first space 17 and collected, the metal particles in the plating solution can be efficiently removed by performing recovery means such as periodically collecting the metal particles. As a result, the frequency of replacement of the filter 65 in the electroplating apparatus 11 can be reduced, and the filter 65 can be omitted in some cases. In addition, the plating liquid in the first space 17, which exceeds the predetermined height, is introduced into the second space 19 and the air is allowed to flow in the second space 19. That is, The dissolved oxygen concentration of the plating solution can be adjusted. Therefore, according to the first embodiment, the dissolved oxygen concentration of the plating liquid can be adjusted, and the cost due to the filter replacement can be reduced.

Specifically, when a soluble anode is used as the anode, since oxygen in the air is received in the plating liquid during plating, a decrease in the dissolved oxygen concentration of the plating liquid can be suppressed. On the other hand, when an insoluble anode is used as the anode, the concentration of dissolved oxygen in the plating liquid can be suppressed from rising because the plating liquid appropriately releases oxygen from the plating liquid to the air.

In the first embodiment, the upper edge portion 23 extends toward the second space 19 and has a protruding piece 27 whose distal end portion is spaced apart from the side surface of the first partition wall 21 . Therefore, the plating liquid flowing into the second space 19 from the first space 17 is guided along the projecting piece 27 to its leading end, and is left in the air away from the leading end of the projecting piece 27 . Therefore, in the first embodiment, it is possible to suppress the plating liquid from flowing down along the side surface of the first bank 21. This makes it possible to more effectively adjust the concentration of dissolved oxygen in the plating liquid because the contact area with the air when the plating liquid is drained can be increased.

≪ Second Embodiment >

4 is a configuration diagram showing a separate tank 15 of the electroplating apparatus 11 according to the second embodiment of the present invention. In this second embodiment, the structure of the first space 17 of the separate tank 15 is different from that of the first embodiment. Here, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

4, the separate tank 15 further has a second partition 35 in addition to the separate tank main body 20 and the first partition 21. The second partition 35 has a substantially rectangular shape and is installed upright from the bottom surface of the separate tank main body 20. The second partition 35 divides the interior of the first space 17 into two spaces. One of the spaces is the supply space 33 through which the plating liquid is supplied from the supply port 29a of the transfer side piping 29 and the other space is located downstream of the supply space 33 and the metal particles 32 in the plating liquid, And a sedimentation space 31 for sedimentation.

The second partition wall 35 has a plurality of communication holes communicating the settling space 31 and the supply space 33. These communication holes are formed below the predetermined height, that is, the height of the upper edge 23 of the first partition 21. In the first space 17, the plating liquid can be moved from the supply space 33 to the settling space 31 through the plurality of communication holes. As the second bank 35, for example, a metal plate, a resin plate, or the like having a plurality of through-holes arranged at a predetermined interval on substantially the whole surface can be used. The communicating port is adjusted so that at least the metal particles can pass through.

In the second embodiment, the first space 17 is divided into the settling space 31 and the supply space 33 by the second partition 35, and the feed pipe 33 is provided with the supply side piping 29 And the plating liquid is supplied from the sphere 29a. Therefore, even when the plating liquid stored in the supply space 33 flows during the supply of the plating liquid, the flow of the plating liquid is difficult to be transmitted to the settling space 31. Therefore, the metal particles 32 can be more effectively settled than in the case where the second partition 35 is not provided in the first space 17.

In the second embodiment, the second partition wall 35 is provided below the predetermined height and has a plurality of communication ports communicating the settling space 31 and the supply space 33. Therefore, the plating liquid supplied to the supply space 33 is dispersed through the plurality of communication holes of the second bank 35 and moved to the settling space 31. As described above, the plating liquid is dispersed through the plurality of communication holes and flows into the settling space 31, so that the plating liquid stored in the settled space 31 can be prevented from flowing.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

≪ Third Embodiment >

5 is a configuration diagram showing a separate tank 15 of the electroplating apparatus 11 according to the third embodiment of the present invention. In this third embodiment, the structure of the first space 17 of the separate tank 15 is different from that of the first embodiment and the second embodiment. Here, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

5, the separate tank 15 further includes a second partition 35 in addition to the separate bath main body 20 and the first partition 21. The second partition 35 has a substantially rectangular shape and is erected upward from the bottom surface of the separate body 20 in the same manner as in the second embodiment. The second partition 35 divides the interior of the first space 17 into a supply space 33 and a settling space 31. The second embodiment differs from the second embodiment in that the second partition 35 of the third embodiment is not provided with a plurality of communication ports.

The height of the upper edge 35a of the second partition 35 is smaller than the height of the upper edge 35a of the second partition 35 in the settling space 31. Therefore, Which is located below the liquid level of the plating liquid stored in the plating liquid. This allows the plating liquid to move from the supply space 33 to the settling space 31 beyond the upper edge 35a of the second partition 35 in the first space 17.

Therefore, in the third embodiment, since the second bank 35 is provided, the flow of the plating liquid when the plating liquid is supplied from the supply port 29a to the supply space 33 is difficult to be transmitted to the settling space 31. [ Since the plating liquid flows into the settling space 31 from the supply space 33 over the upper edge 35a of the second bank 35, the metal particles 32 precipitated below the settling space are rewound It is possible to suppress occurrence of work.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

≪ Fourth Embodiment &

Fig. 6 is a configuration diagram showing an electroplating apparatus 11 according to a fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in that a re-supply pipe 43 is provided. Here, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

6, in the fourth embodiment, the electroplating apparatus 11 further comprises a re-supply pipe 43 for returning the plating liquid discharged from the separate tank 15 to the first space 17 have. One end 43a of the re-supply pipe 43 is connected to the lower portion of the side of the separate bath main body 20 and communicates with the second space 19. [ And the other end 43B is disposed in the upper portion of the first space 17. [ The re-supply pipe 43 is provided with a pump 66 and a filter 68.

Therefore, in the fourth embodiment, a part of the plating liquid in the second space 19 of the separate tank 15 is returned to the first space 17 through the re-supply pipe 43 before returning to the plating tank 13 Can supply. Foreign matter in the plating liquid can be removed more efficiently.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

≪ Embodiment 5 >

7 is a configuration diagram showing an electroplating apparatus 11 according to a fifth embodiment of the present invention. The fifth embodiment is different from the first embodiment in that an underflow partition plate 45 is disposed in the second space 19. [ Here, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

As shown in Fig. 7, in the fifth embodiment, a partition plate 45 is further provided in the second space 19 located on the downstream side of the first space 17. As shown in Fig. The partition plate 45 forms a gap between the lower end of the partition plate 45 and the bottom surface of the separate body 20 in the second space 19, (19) is divided into two regions: an upstream region and a downstream region. Therefore, the plating liquid flowing into the second space 19 from the first space 17 always passes through the gap when moving from the upstream region to the downstream region in the second space 19. Therefore, the plating liquid in the second space 19 is more uniformly stirred.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

≪ Sixth Embodiment &

8A and 8B are diagrams showing a part of the plating tank 13 of the electroplating apparatus 11 according to the sixth embodiment of the present invention. Fig. 8A is a diagram showing a part of the plating tank 13 viewed from the side And FIG. 8B is a view from above. In the sixth embodiment, the structure of the overflow tank 49 of the plating tank 13 is different from that of the first embodiment. Here, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

8A and 8B, in the sixth embodiment, the overflow tank 49 of the plating tank 13 is provided with an upstream space 71 and a downstream space 71 located downstream of the upstream space 71 And a downstream side space 73 formed in the downstream side. The overflow set 49 is composed of two sets (the first set 75 and the second set 77). The upstream space 71 is a space surrounded by the first tank 75 and the side wall 51 of the tank body 47. The downstream space 73 is a space surrounded by the second tank 77 and the tank body 47 Is a space surrounded by the side wall (51).

The upper side edge portion 53 of the side wall 51 of the bath main body 47, the upper edge portion of the first bath 75 and the second bath 77 of the upper side edge portion of the second bath 77 are the highest , And the first group (75) is the lowest. As shown in FIG. 8B, a pair of overflow portions 81 is formed on the upper edge portion of the first tank 75. These overflow portions 81 are lower than other portions in order to allow the plating liquid to overflow and flow from the first bath 75 into the second bath 77. [ A through hole 79 through which the delivery pipe 29 is connected is formed on the bottom surface of the second tank 77.

The plating liquid overflows the upper edge portion 53 of the side wall 51 of the bath main body 47 and flows into the upstream space 71 of the first bath 75 and flows into the first bath 75 Flows into the downstream side space 73 of the second tank 77 and flows into the transfer side pipe 29 through the through hole 79. [ As described above, in the sixth embodiment, the plating liquid flows down through the air twice. Therefore, the dissolved oxygen concentration of the plating solution can be adjusted not only in the separate bath 15 but also in the overflow tank 49 of the plating bath 13.

Particularly, in this sixth embodiment, by making the drop from the upper edge portion of the first tank 75 to the liquid surface of the second tank 77 larger than 10 cm, the plating liquid flows from the upstream space 71 to the downstream space 73), and the dissolved oxygen concentration is efficiently adjusted while the air is flowing down.

It is preferable that the upper side edge portion 53 of the side wall 51 of the bath main body 47 has a projecting piece as shown in Fig. It is preferable that the upper edge portion of the first set 75 also has a protruding piece as shown in Fig. The plating liquid flowing into the first tank 75 from the bath main body 47 and the plating liquid flowing into the second tank 77 from the first tank 75 are discharged to the outside through the projecting pieces And is held in the air away from the leading projecting piece from the leading end. Therefore, it is possible to suppress the plating solution from flowing down on the side surface of the bath main body or the side surface of the first tank 75. This makes it possible to more effectively adjust the concentration of dissolved oxygen in the plating liquid because the contact area with the air when the plating liquid is drained can be increased.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

≪ Seventh Embodiment &

9A and 9B are diagrams showing a part of the plating tank 13 of the electroplating apparatus 11 according to the seventh embodiment of the present invention. FIG. 9A is a diagram showing a part of the plating tank 13 viewed from the side And Fig. 9B is a view from above. In the seventh embodiment, the structure of the overflow tank 49 of the plating tank 13 is different from that of the first embodiment, and the structure of the first tank 75 is different from that of the sixth embodiment. The same reference numerals are given to the same constituent elements as those of the first and sixth embodiments, and a detailed description thereof will be omitted.

9A and 9B, in the seventh embodiment, the first tank 75 has a through-hole 85 on the bottom surface thereof, and the discharge tube 83 is connected to the through-hole 85, respectively have. The plating liquid in the upstream space 71 flows through the discharge pipe 83 and flows into the downstream space 73 by flowing down the air. The bottom portion of the first set 75 is disposed above the bottom portion of the second set 77. The discharge tube 83 can be omitted.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

≪ Embodiment 8 >

10 is a configuration diagram showing an electroplating apparatus 11 according to an eighth embodiment of the present invention. The eighth embodiment differs from the first embodiment in that the number of overflows in the separate tank 15 is two. Here, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

As shown in Fig. 10, in the eighth embodiment, the separate tank 15 further includes a third partition 91. [ The third partition wall 91 has a substantially rectangular shape and is erected upward from the bottom surface of the separate bath main body 20. The inside of the separate tank 15 is divided into a second space 19 by the third partition 91 and a third space 93 located on the downstream side of the second space 19. Thus, the concentration of dissolved oxygen in the plating liquid can be adjusted more efficiently.

Further, in the eighth embodiment, the underfloor partition plate 45 is further provided in the second space 19 and the third space 93 on the downstream side of the first space 17 in which the metal particles are settled . 7, these partition plates 45 are disposed between the bottom edge of the partition plate 45 and the bottom surface of the separate bath main body 20 in the second space 19 and the third space 93, The second space 19 is divided into two regions, that is, an upstream region and a downstream region, and the third space 93 is divided into an upstream region And a region on the downstream side. Therefore, the plating liquid flowing into the second space 19 from the first space 17 always passes through the gap when moving from the upstream region to the downstream region in the second space 19. The plating liquid flowing into the third space 93 from the second space 19 always passes through the gap when moving from the upstream region to the downstream region in the third space 93, And the third space 93, the plating liquid is more uniformly stirred.

The upper side edge portion 24 of the third partition wall 91 has the same structure as the upper side edge portion 23 of the first partition wall 21. Since the upper edge 24 of the third partition wall 91 has the protruding piece 27 like the upper edge 23 of the first partition 21, The plating liquid flowing into the plating chamber 93 is guided along the projecting piece 27 to the leading end thereof and is left in the air away from the leading projecting piece 27 from the leading end. Therefore, it is possible to prevent the plating liquid from flowing down on the side surface of the third partition wall 91. This makes it possible to more effectively adjust the concentration of dissolved oxygen in the plating liquid because the contact area with the air when the plating liquid is drained can be increased.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

≪ Ninth Embodiment &

11A and 11B are diagrams showing a first bank 21 of a separate tank of the electroplating apparatus according to the ninth embodiment. In the ninth embodiment, the plating liquid does not overflow the upper edge 23 of the first partition 21 but has a through hole 95 formed at the predetermined height of the first partition 21 So that the plating solution flows into the second space 19 from the first space 17.

In the ninth embodiment, the plating liquid may flow down from the first space 17 to the second space 19 while flowing on the side surface of the first partition 21, It is better to leave the side without riding. For example, as shown in Fig. 11B, the first partition 21 has a protruding piece 95a projecting laterally from the lower side edge portion of the through-hole 95 on the side located on the second space 19 side, . In this case, the plating liquid flowing into the second space 19 from the first space 17 is guided along the projecting piece 95a to the leading end thereof, and is separated from the leading projecting piece 95a from the leading end thereof, do. Therefore, it is possible to suppress the plating solution from falling on the side surface of the first bank 21. This makes it possible to more effectively adjust the concentration of dissolved oxygen in the plating liquid because the contact area with the air when the plating liquid is drained can be increased.

Other configurations, actions, and effects are the same as in the first embodiment, although the description thereof is omitted.

<Other Embodiments>

The present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention.

For example, in each of the above-described embodiments, the case where the object to be plated is plated with copper is described as an example. However, the present invention can be applied to other electroplating such as electric nickel plating and electric gold plating besides electroplating.

In the above-described embodiment, the separate tank 15 is divided into two or three spaces by barrier ribs. However, the separate tank 15 may be divided into four or more spaces.

Further, the re-supply pipe as in the fourth embodiment may be provided in the electroplating apparatus of another embodiment.

The electroplating apparatuses and the electroplating method using the electroplating apparatuses of the above embodiments are preferable for use in forming a wiring pattern or the like on a printed substrate, a wafer, or the like as objects to be painted, but the present invention is not limited thereto.

The above embodiments are summarized as follows.

The electroplating apparatus of the above embodiment is provided with a plating tank in which a plating liquid is stored and a separate tank in which the plating liquid is circulated between the plating tank and the plating tank as a separate tank. Wherein the separate bath has a first space and a second space located on the downstream side of the first space, and the second space is formed in the first space, And the plating liquid flows in the air in the second space.

In this configuration, since the plating solution flows into the second space from the first space by a distance exceeding a predetermined height, the metal particles in the plating solution remaining in the first space remain in the first space It can be set downward. When the metal particles are precipitated below the first space and collected, the metal particles in the plating solution can be efficiently removed by performing a recovery means such as periodically collecting the metal particles. As a result, the frequency of replacement of the filter in the electroplating apparatus can be reduced, or the filter can be omitted in some cases.

In addition, the amount of the plating solution in the first space that exceeds the predetermined height is introduced into the second space, and the air in the second space is allowed to flow down, that is, the plating solution in the flowing state is exposed to the air, Can be adjusted.

As described above, according to this configuration, the dissolved oxygen concentration of the plating solution can be adjusted, and the cost resulting from the replacement of the filter can be reduced.

Specifically, the structure of the separate vessel may include, for example, a partition wall extending in the up-and-down direction to divide the first space and the second space, and the plating liquid in the first space is divided into the predetermined And an upper edge portion located at a height is overflowed and flows into the second space.

In the above electroplating apparatus, it is preferable that the upper edge portion of the partition wall has a protruding piece extending toward the second space side, and the protruding piece has a distal end spaced apart from the side surface of the partition wall.

In this configuration, the plating liquid flowing into the second space from the first space is guided to the tip of the plating liquid along the projecting piece, and is left in the air away from the leading projecting piece. That is, when the protruding piece is not formed on the upper edge portion, the plating liquid flowing into the second space from the first space tends to fall on the side surface while contacting with the side surface of the partition. In this configuration, It can be suppressed from being abraded by riding. This makes it possible to more effectively adjust the concentration of dissolved oxygen in the plating liquid because the contact area with the air when the plating liquid is drained can be increased.

In the electroplating apparatus, the projecting piece may have a transverse portion extending in the transverse direction on the second space side and a longitudinal portion extending downward from the distal end of the transverse portion, the tip of the transverse portion being spaced apart from the side surface of the partition .

In this configuration, since the plating liquid flowing into the second space from the first space is guided along the longitudinal portion to the front end thereof, the distance from the side surface of the partition wall is increased and then downwardly downward along the longitudinal portion. It is possible to further suppress the abrasion caused by riding.

In the electroplating apparatus, the separate bath may be a structure in which the plating liquid in the first space flows into the second space through a through-hole located at the predetermined height in the partition.

Further, the electroplating apparatus further comprises a transfer side pipe for transferring the plating liquid from the plating bath to the separate bath, and the transfer side pipe has a supply port for supplying the plating liquid to the first space, And is preferably located below the predetermined height.

In this configuration, since the supply port of the transfer-side pipe is located below the predetermined height, that is, below the liquid level of the plating liquid stored in the first space, when the plating liquid is supplied from the supply port to the first space, The plating solution can be directly supplied into the plating solution. When the plating liquid is directly supplied to the plating liquid in the first space as described above, the impact on the plating liquid in the first space is reduced as compared with the case where the plating liquid once discharged from the supply port into the air drops onto the surface of the plating liquid stored in the first space can do. As a result, the plating liquid stored in the first space is prevented from flowing, and the metal particles can be settled more efficiently in the first space.

When the discharge direction of the plating liquid from the supply port is directed to the inner side surface of the separate vessel, the flow of the plating liquid stored in the first space, in particular, the flow of the plating liquid in the downward direction It is possible to suppress the flow of the plating liquid in the plating bath. As a result, it is possible to suppress the occurrence of rewinding of the metal particles precipitating in the first space, so that the settling of the metal particles in the first space can be suppressed.

In addition, the electroplating apparatus may further include a transfer side pipe for transferring the plating liquid from the plating bath to the separate bath, wherein the bank is a first bank, and the separate bath is formed by inserting the inside of the first space into the plating bath, And a second partition wall extending in the up and down direction to divide the deposit space into a supply space for supplying the plating solution from the supply port of the transfer side pipe and located on the upstream side of the settling space .

In this configuration, since the first space is divided into the settling space and the supply space by the second bank, and the plating liquid is supplied from the supply port of the transfer side pipe to the supply space, the plating liquid stored in the supply space during the supply of the plating liquid flows So that the flow of the water is hardly transmitted to the settling space. Therefore, the metal particles can be precipitated more efficiently than in the case where the second partition is not provided in the first space.

When the second bank is provided below the predetermined height and has a plurality of communication holes communicating with the settling space and the supply space, the plating liquid supplied to the supply space is supplied to the plurality of communication holes of the second bank, And is moved to the settling space. As described above, the plating liquid is dispersed through the plurality of communication holes and flows into the settling space, so that the plating liquid stored in the settled space can be prevented from flowing.

When the upper edge of the second bank is located below the predetermined height or the predetermined height, the height of the upper edge of the second bank is equal to or less than the level of the plating liquid stored in the settling space. Therefore, since the liquid level of the plating liquid in the settling space and the liquid level of the plating liquid in the supply space become almost the same height, the impact when the plating liquid flows into the settling space from the supply space can be alleviated. As a result, it is possible to restrain the metal particles that are settling in the settling space from being rewound, so that the setting of the settling of the metal particles in the settled space can be suppressed.

The electroplating apparatus further includes a return side pipe returning the plating solution from the separate vessel to the plating bath and a re-supply pipe returning the plating solution discharged from the separate vessel to the first space A part of the plating liquid in the separate bath may be supplied to the first space again through the re-supply pipe before returning to the plating bath. This makes it possible to more efficiently separate foreign substances in the plating liquid.

When the apparatus further includes a mechanical stirrer provided in a space on the downstream side of the first space, the metal particles are settled in the first space, and then the plating liquid is stirred by the mechanical stirrer in a space on the downstream side . Thus, fine adjustment of the dissolved oxygen concentration of the plating liquid can be performed.

The plating bath has an overflow tank which is integrally provided with the bath main body and in which the plating liquid of the bath main body overflows the upper side edge portion of the side wall of the bath main body, This overflow tank has an upstream side space and a downstream side space located on the downstream side of the upstream side space and has a structure in which the plating liquid flows into the downstream side space from the upstream side space to flow down the air good.

In this configuration, the dissolved oxygen concentration of the plating solution can be adjusted not only in the separate vessel but also in the overflow tank in the plating vessel. In this overflow tank, the dissolved oxygen concentration is adjusted while the plating liquid flows into the downstream space from the upstream space and flows down the air.

When the upper edge of the bath main body has a protruding piece extending to the overflow tank and the protruding piece has a distal end spaced apart from the side surface of the bath main body, Is guided along the projecting piece to its distal end portion, is separated from the forward projecting piece from its distal end portion, and is left in the air. Therefore, in this configuration, it is possible to suppress the plating liquid from falling down on the side surface of the bath main body. This makes it possible to more effectively adjust the concentration of dissolved oxygen in the plating liquid because the contact area with the air when the plating liquid is drained can be increased.

It is preferable that the falling distance of the plating solution in the second space is 10 cm or more. As described above, since the drop height is 10 cm or more, it is possible to more effectively adjust the dissolved oxygen concentration of the plating solution in the separate bath.

The electroplating method of the embodiment uses an electroplating apparatus having a plating bath in which a plating solution is stored and a separate bath in which the plating solution circulates between the plating bath and the plating bath as a separate bath. The separate vessel has a first space therein and a second space located downstream of the first space. In this method, the plating liquid is stored in the first space to a predetermined height, and the metal particles in the plating liquid settle down below the first space. Also, in this method, a portion of the plating solution in the first space exceeding the predetermined height is introduced into the second space, and the dissolved oxygen concentration of the plating solution is adjusted by flowing air in the second space. This makes it possible to adjust the dissolved oxygen concentration of the plating liquid and effectively remove the metal particles in the plating liquid.

The electroplating apparatus and the electroplating method of the above embodiments are particularly preferable when the plating liquid is used for copper plating and contains sulfur-containing organic compounds as a polishing agent.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

&Lt; Example 1 >

Electroplating was performed on the objects to be plated (samples Nos. 1 to 8) under the following conditions using an electroplating apparatus. In the samples Nos. 2 to 4, the electroplating apparatus 11 shown in Fig. 12 was used. In the electroplating apparatus 11, the plating vessel 13 is the same as the structure shown in Fig. 1, and the separate vessel 15 is divided into the first vessel wall 21 and the third vessel wall 91 in the separate vessel body 20 The first space 17, the second space 19, and the third space 93. In this case, The plating liquid overflows the upper edge of the first partition 21 and flows into the second space 19 from the first space 17 and overflows the upper edge of the third partition 91 to form the second space 19 ) Into the third space (93). And the second space 19 is provided with a partition plate 45 for underflow.

In the samples Nos. 1 and 5 to 8, the separators 21 and 91 were detached from the separate vessel 15 of the electroplating apparatus 11 shown in FIG. 12 and used.

As shown in Table 2 to be described later, the structure of the upper edge of the first bank 21 and the bank of the third bank 91 was a structure A (structure shown in Fig. 2D) of Sample No. 4, , And 3 in structure B (structure shown in Fig. 2E).

As shown in Table 2 to be described later, the dropout from the upper edge of the first bank 21 and the third bank 91 to the liquid level of the plating liquid was set to three conditions of 5 cm, 10 cm and 20 cm.

A stainless steel plate and a substrate having a via hole (a printed board having a blind via hole) were used as a cathode (cathode). The opening diameter of the via hole in this substrate was 100 mu m, and the depth of the via hole was 75 mu m.

Other conditions of electroplating are as follows.

The total amount of the bath of the plating bath 13 (the bath amount of the bath main body 47 and the overflow bath 49): 4300 liters

The total amount of the bath in the separate bath 15 (the total amount of bath in the first space 17, the second space 19 and the third space 93): 800 liters

Bath capacity: 5100 liters

Plating solution: copper sulfate plating solution (containing copper sulfate pentahydrate 200 g / L, sulfuric acid 50 g / L, and chloride ion 50 mg / L)

Additive added to the plating solution: THRU-CUP EVF-T manufactured by Uemura Kogyo Co.

Circulating rate of plating solution: 860 liters / minute

Anode: Soluble anode (containing phosphorus-containing copper balls in a titanium case and accommodating them in an anode bag made of polypropylene)

Under the above conditions, electroplating was performed on the object to be plated, and the dissolved oxygen concentration, the physical properties of the film, and the amount of depression of the via hole were evaluated. The evaluation of physical properties (elongation and tensile strength) of the film was made by subjecting the above-mentioned stainless steel plate of the object to be plated to copper plating of 50 占 퐉. The evaluation of the depression of the via hole was made by subjecting the substrate having the via hole of the object to be plated to 20 占 퐉 copper plating.

In Example 1, the stainless steel sheet was subjected to the pretreatment, the electroplating treatment and the post-treatment in the order of the following steps 1 to 8.

Step 1: SanSe Cleaner (MSC-3-A manufactured by Uemura High School)

Step 2:

Step 3: Washing

Step 4: Pickles

Step 5: Washing

Step 6: Electroplating

Step 7: Washing

Step 8: Drying

After the desmear treatment and the chemical plating (0.3 탆) treatment are performed on the substrate having the via hole, pretreatment, electroplating treatment and post treatment are performed in the order of steps 1 to 8 as described above did.

The conditions of the electroplating in Example 1 are shown in Table 1. The treatment temperature (the temperature of the plating solution) of the electroplating was set at 25 캜. The unit of the cathode current density in Table 1 is A / dm 2.

Stainless steel plate Substrate with via hole Cathode current density (ASD) 1.0 1.0 Plating time (min) 226 90 Film thickness (占 퐉) 50 20

The results are shown in Table 2. Table 3 shows the test procedure of each sample. In Table 4, after the plating process of Sample No. 1 is finished, the dissolved oxygen concentration when electrolytic was applied for 30 minutes, 60 minutes, and 90 minutes with the partition walls 21 and 91 shown in Fig. . A part of the plating liquid supplied to the bath main body 47 through the return side pipe 41 is supplied to the pipe end portion 41c (cathode 57) so that the flow rate of the plating liquid from each nozzle 61 to the plating object (cathode 57) ). The dissolved oxygen concentration of the plating solution collected from a valve (not shown) attached to a pipe near the pipe end 41c in FIG. 12 was measured.

The amount of depression of the via hole is obtained by performing the copper plating 103 on the substrate 101 having the via hole shown in Fig. 15A as shown in Fig. 15B, and then the lowest part of the surface of the copper plating 103 formed in the via hole 101c (The dimension in the thickness direction) of the surface of the copper plating 103 formed on the peripheral edge of the via hole 101c (Fig. 15B). The substrate 101 having a via hole shown in Fig. 15A has a resin layer 101a and a copper layer 101b formed on the surface of the resin layer 101a, and a via hole 101c is formed in the copper layer 101b.

The elongation and tensile strength were measured as follows using the test piece shown in Fig. That is, first, a stainless steel plate was plated with copper of 50 mu +/- 5 mu m, and then a copper-plated layer (copper foil) was delicately peeled off from the stainless steel sheet so as to prevent wrinkles or damage. After the copper foil was heat-treated at 120 ° C for 2 hours, holes were drilled in the shape shown in Fig. 16 to form test pieces. The film thickness at the center of the test piece was measured by a fluorescent X-ray film thickness meter, and the measured value was defined as the film thickness [d (mm)] of the test piece. Subsequently, the distance between the chucks of the tensile testing machine was set to 40 mm, and the test piece was clamped by a chuck so that the portion of the test piece exposed from the chuck was fixed, and the test was performed at a tensile speed of 4 mm / min. Then, the maximum tensile stress [F (kgf)] was read from the chart obtained by the test and the value [F (kgf)] was divided by the cross-sectional area of the test piece, )]. The cross-sectional area of the test piece was obtained by multiplying the width of the center portion of the test piece by 10 mm and the film thickness d mm. The elongation [E (%)] is a value obtained by measuring the elongated dimension [? L (mm)] from the start of tensile test of the test piece to the breakage of the test piece, (20 mm).

Sample No. One A cathode current density of 1.0 ASD was applied for 30 hours using a separate bath without a partition (partition plate).
Thereafter, a substrate having a stainless steel plate and a via hole was plated. 2 And was passed for 24 hours at 1.0 ASD using the separate bath shown in Fig.
Thereafter, a substrate having a stainless steel plate and a via hole was plated. 3 And was passed for 24 hours at 1.0 ASD using the separate bath shown in Fig.
Thereafter, a substrate having a stainless steel plate and a via hole was plated. 4 And was passed for 24 hours at 1.0 ASD using the separate bath shown in Fig.
Thereafter, a substrate having a stainless steel plate and a via hole was plated. 5 Subsequently to Sample No. 4, the plating solution was circulated for 8 hours using a separate bath without a partition (partition plate).
Thereafter, a substrate having a stainless steel plate and a via hole was plated. 6 Subsequently to Sample No. 5, the plating solution was circulated for 8 hours using a separate bath without partition walls (partition plate).
Thereafter, a substrate having a stainless steel plate and a via hole was plated. 7 Subsequently to Sample No. 6, the plating solution was circulated for 8 hours using a separate bath without partition walls (partition plate).
Thereafter, a substrate having a stainless steel plate and a via hole was plated. 8 Subsequently to Sample No. 7, the plating solution was circulated for 8 hours using a separate bath without partition walls (partition plate).
Thereafter, a substrate having a stainless steel plate and a via hole was plated.

Delivery time
(minute) Dissolved oxygen concentration
(Mg / liter) 30 4 60 5.9 90 7.6

From the result of the sample No. 1 in Table 2, it was found that when the separate vessel in which the partitions 21 and 91 were not provided was used, the dissolved oxygen concentration of the plating liquid was low and the amount of the via hole was increased.

From the results of the samples Nos. 2 to 4, it was found that the concentration of dissolved oxygen was increased by providing the partition walls 21 and 91 in the separate bath 15 to overflow the plating liquid. In addition, it was found that the dissolved oxygen concentration was remarkably increased by setting the drop of the plating solution at overflow to 10 cm or more as in the samples Nos. 3 and 4. In these samples Nos. 3 and 4, the dissolved oxygen concentration did not decrease even after long-term electrolysis.

From the results of the samples Nos. 5 to 8, which were carried out after the plating process of the sample No. 4, when the partition walls 21 and 91 were removed from the separate bath 15, the dissolved oxygen concentration decreased as the electrolysis time became longer, The amount of depression tends to increase.

Further, as shown in Table 4, it was found that when the barrier ribs 21 and 91 were attached and electrolyzed in the separate vessel after the plating treatment of the sample No. 1, the dissolved oxygen concentration became higher with time.

&Lt; Example 2 >

Electroplating was performed on the objects to be plated (Sample Nos. 9 to 14) under the following conditions using the electroplating apparatus shown in Figs. 13A and 13B. In the samples Nos. 12 to 14, a separate vessel having the same partition walls 21 and 91 as the apparatus of FIG. 12 was used as the separate vessel 15. 13A and 13B, the plating tank 13 is provided with a bath main body 47 and an overflow bath 49, and the plating liquid overflowed from the bath main body 47 is supplied to the overflow bath (not shown) 49). Plate-shaped objects to be plated, which is a cathode 57, are arranged substantially horizontally in the bath main body 47, and a plurality of anodes 55 are arranged above and below the cathode 57, respectively. In addition, nozzles 61 are arranged above and below the cathode 57, respectively. Each of the nozzles 61 is provided with a plurality of jetting openings (not shown) for jetting the plating liquid fed from the separate vessel 15 through the return side piping 41 toward the cathode 57 side.

In Sample Nos. 9 to 11, the separators 21 and 91 were removed from the separate vessel 15 and used.

As shown in Table 6 below, the dropping from the upper edge of the first bank 21 and the third bank 91 to the liquid level of the plating liquid was performed under three conditions of 5 cm, 10 cm and 20 cm.

A stainless steel plate and a substrate having a through hole were used as a cathode (cathode). The inner diameter of the through hole in this substrate was 0.3 mm, and the thickness of the substrate was 1.6 mm.

Other conditions of electroplating are as follows.

The total amount of bath of plating bath 13 (total bath amount of bath main body 47 and overflow bath 49): 1000 liters

The total amount of the bath of the separate bath 15 (total amount of bath in the first space 17, the second space 19 and the third space 93): 1400 liters

Bath capacity: 2400 liters

Plating solution: Copper sulfate plating solution (containing 100 g / L of copper sulfate pentahydrate, 200 g / L of sulfuric acid, and 50 mg / L of chloride ion)

Additive added to the plating solution: "THRU-CUP ETN" produced by Uemura High School

Circulating rate of plating solution: 3000 liters / minute

Anode: An insoluble anode (Ti-Pt coated with iridium oxide)

In Example 2, the stainless steel sheet was subjected to the pretreatment, the electroplating treatment and the post-treatment in the order of Steps 1 to 8 as in Example 1.

The substrate having the through-hole was subjected to a pretreatment in the same manner as in Example 1, followed by a pretreatment in the same manner as in Example 1, a copper plating (0.3 m) Processing, and post-processing.

The conditions of the electroplating in Example 2 are shown in Table 5. The treatment temperature (the temperature of the plating solution) of the electroplating was set at 25 캜. The unit of the cathode current density in Table 5 is A / dm 2.

Stainless steel plate Substrate with Through Hole Cathode current density (ASD) 5.0 5.0 Plating time (min) 45 27 Film thickness (占 퐉) 50 30

Under the above conditions, electroplating was performed on the object to be plated, and the dissolved oxygen concentration, physical properties of the film, and uniform electrodeposition (TH-TP) of through holes were evaluated. The results are shown in Table 6. Table 7 shows the test procedure of each sample. The dissolved oxygen concentration of the plating solution collected from the valve (not shown) attached to the return-side pipe 41 on the downstream side of the filter 65 in Fig. 13 was measured.

The uniform electrodeposition is defined as the ratio of the thickness of the copper plating in the center of the through hole in the depth direction to the thickness of the copper plating in the substrate surface near the through hole. That is, as shown in Fig. 17, the uniform electrodeposition (TH-TP) is carried out in such a manner that copper plating 107 is performed on the substrate 105 on which the through-hole 105a is formed under the above- And the thicknesses (a to d) of the copper surface plating on the surface of the substrate near the through holes are respectively measured and the respective values are substituted into the following equation (5).

TH-TP (%) = 2 (e + f) / (a + b + c +

Sample No. 9 By circulating the plating solution using a separate bath without a partition (partition plate)
A stainless steel plate, and a substrate were plated. 10 Sample No. 9 was continuously passed for 3 hours.
Thereafter, the stainless steel plate and the substrate were plated. 11 Following Sample No. 10, it was passed for 3 hours.
Thereafter, the stainless steel plate and the substrate were plated. 12 A cathode current density of 5.0 ASD was delivered for 24 hours using a separate vessel with a bulkhead.
Thereafter, the stainless steel plate and the substrate were plated. 13 It was delivered for 24 hours at 5.0 ASD using a septum with a septum.
Thereafter, the stainless steel plate and the substrate were plated. 14 It was delivered for 24 hours at 5.0 ASD using a septum with a septum.
Thereafter, the stainless steel plate and the substrate were plated.

From the results of Sample No. 9 in Table 6, the dissolved oxygen concentration was 7.4 mg / liter at the start of plating, and thus the physical properties of the coating film were good. However, from the results of the samples Nos. 10 and 11, when the electrolysis time was prolonged, the dissolved oxygen concentration was increased, and in the sample No. 10 after 3 hours, physical properties of the coating film were deteriorated and TH- The sample No. 11 after the elapse of time showed that the physical properties of the film were worse and the TH-TP was lowered to 65.6%.

On the other hand, in the samples Nos. 12 to 14, it is possible to suppress the rise of the dissolved oxygen concentration by providing the partition walls 21 and 91 in the separate bath 15 to overflow the plating liquid. In particular, as in the case of the sample Nos. 13 and 14, it was found that the effect of suppressing the rising of the dissolved oxygen concentration was remarkably increased by setting the drop of the plating liquid at the time of overflow to 10 cm or more. In these samples Nos. 13 and 14, the dissolved oxygen concentration can be lowered to 20 mg / liter or less, physical properties of the coating film are good, and TH-TP is 75% or more.

&Lt; Example 3 >

Electroplating was performed on the objects to be plated (Sample Nos. 15 to 18) under the following conditions using the electroplating apparatus shown in Fig. In the sample Nos. 17 and 18, a separate vessel having the same partition walls 21 and 91 as the apparatus of Fig. 12 was used as the separate vessel 15. 14, the plating tank 13 is provided with a bath main body 47 and an overflow bath 49, and the plating liquid overflowed from the bath main body 47 is supplied to the overflow bath 49 It is the incoming structure.

The inside of the bath main body 47 is divided into two spaces by the diaphragm 99. As this diaphragm 99, "Y-9205T" manufactured by Yuasa Membrane System Co., Ltd. was used. An anode 55 is disposed in the other space, and a cathode 57 is disposed in one space. A nozzle 61 is disposed in the vicinity of the cathode 57. The nozzle 61 is provided with a jet port (not shown) for jetting the plating liquid fed from the separate tank 15 through the return side pipe 41 toward the cathode 57 side.

In the samples Nos. 15 and 16, the separators 21 and 91 were separated from the separate vessel 15 and used.

As shown in Table 9 to be described later, the dropout from the upper edge of the first bank 21 and the third bank 91 to the liquid level of the plating liquid was set to two conditions of 10 cm and 20 cm.

A wafer having a stainless steel plate and a blind via hole was used as a material to be cast (cathode). The opening diameter of the via hole in this substrate was 15 mu m, and the depth of the via hole was 25 mu m.

Other conditions of electroplating are as follows.

The total amount of bath of plating bath 13 (total bath amount of bath main body 47 and overflow bath 49): 50 liters

The total amount of the bath of the separate bath 15 (total amount of bath in the first space 17, the second space 19 and the third space 93): 150 liters

Amount of bath: 200 liters

Plating solution: copper sulfate plating solution (containing copper sulfate pentahydrate 200 g / L, sulfuric acid 50 g / L, and chloride ion 50 mg / L)

Additive added to the plating solution: "THRU-CUP ESA-21" manufactured by Uemura Kogyo Co.

Circulating rate of plating solution: 100 liters / minute

Anode: Soluble anode (containing phosphorus-containing copper balls in titanium case)

In Example 3, the stainless steel sheet was subjected to the pretreatment, the electroplating treatment, and the post-treatment in the order of Steps 1 to 8 as in Example 1.

The wafer was subjected to a pretreatment, an electroplating treatment and a post treatment in the order of steps 1 to 8 as in Example 1, after the barrier layer and the seed layer were formed by well-known methods.

The conditions of the electroplating in Example 3 are shown in Table 8. &lt; tb &gt;&lt; TABLE &gt; The treatment temperature (the temperature of the plating solution) of the electroplating was set at 25 캜. The unit of the cathode current density in Table 8 is A / dm 2.

Stainless steel plate wafer Cathode current density (ASD) 1.0 1.0 Plating time (min) 226 23 Film thickness (占 퐉) 50 5

Under the above conditions, electroplating was performed on the object to be plated, and the dissolved oxygen concentration, the physical properties of the film, and the amount of depression of the via hole were evaluated. The results are shown in Table 9. Table 10 shows the test procedure of each sample. The dissolved oxygen concentration of the plating solution collected from a valve (not shown) attached to the return-side piping 41 on the downstream side of the filter 65 in Fig. 14 was measured.

In Sample No. 15, air was supplied into the plating liquid by using the air agitator 94 in the first space 17 of the separate tank 15, thereby performing plating while air agitation was performed.

Sample No. 15 A cathode current density of 1.0 ASD was delivered for 24 hours using a separate bath without a partition (partition plate).
Thereafter, the stainless steel plate and the substrate were plated. 16 After plating the sample No. 15, replace the filter
Immediately thereafter, the stainless steel sheet and the substrate were plated. 17 It was delivered at 1.0 ASD for 24 hours using a septum with a septum.
Thereafter, the stainless steel plate and the substrate were plated. 18 It was delivered at 1.0 ASD for 24 hours using a septum with a septum.
Thereafter, the stainless steel plate and the substrate were plated.

In Sample No. 15 of Table 9, while electrolyzing air in the first space 17 of the separate bath 15, the dissolved oxygen concentration of the plating bath 13 was 3.8 mg / liter as shown in Table 9, The dissolved oxygen concentration of the separate bath (15) was 7.2 mg / liter. In this way, by performing the air agitation, the dissolved oxygen concentration in the separate bath can be maintained in a preferable range. However, air agitation is performed to prevent the settling of the copper particles in the first space 17, Adhesion was confirmed. Since the dissolved oxygen is consumed by the copper particles attached to the filter 65, the dissolved oxygen concentration in the plating bath lowers and the amount of the via hole tends to be large.

From the result of the sample No. 16, since the copper particles are hardly attached immediately after the filter 65 is exchanged, the dissolved oxygen concentration of the plating bath becomes a good value, and the amount of the via hole is also reduced.

In Sample Nos. 17 and 18, it was found that copper particles were effectively precipitated in the first space 17 because the copper particles were hardly adhered to the filter 65 (new original white state). By providing the partition walls in the separate vessel and overflowing the plating liquid in this manner, the dissolved oxygen concentration becomes high, and the copper particles can be efficiently separated from the plating liquid. As a result, the dissolved oxygen concentration in the plating bath is maintained within a preferable range, and the amount of the via hole is reduced.

<Reference example>

The relationship between the concentration of dissolved oxygen, the concentration of the brightener, and the Ar value in the plating solution was examined using a cyclic voltammetric stripping (CVS) measurement method. The method of CVS measurement is as follows.

1) Method of measuring Ar value

A plating solution, a stripping solution, and a cleaning solution were prepared by immersing a rotating platinum electrode as a working electrode, a copper bar as a counter electrode, and a double junction electrode as a reference electrode, respectively, The procedure is repeated to prepare a potential-current curve (Volta mmogram), and the area (Ar value) of the peeling process is obtained from this potential-current curve.

The results shown in Tables 11 and 12 are obtained by applying the above CVS measurement method, and are the changes over time in Ar value obtained by repeating sweeping continuously in the above measuring method.

2) Measuring instrument used for Ar value measurement, measurement condition

Measuring instrument: "QL-5" manufactured by ECI

Measurement conditions: rotation number of rotation platinum electrode: 2500 rpm, potential sweep rate: 100 mV / sec, temperature: 25 DEG C

3) Measuring solution

The measurement solution was prepared as follows. 30 mL of VMS to be described later was placed in a vessel, and 30 mL of the plating solution to be measured was added to this vessel.

4) VMS and measurement target plating amount

The plating solution to be measured is as shown in Table 11 for Sample Nos. 19 to 23, and as shown in Table 12 for Sample Nos. That is, the sample liquid of Sample No. 19 to be measured is a plating liquid collected from a valve (not shown) attached to a pipe near the pipe end portion 41c in FIG. 12 during the plating process of Sample No. 1 of Example 1. 20 is the plating liquid sampled from the same place during the plating process of the sample No. 3 of Example 1. [ The plating solution of the sample No. 24 to be measured was supplied from a valve (not shown) attached to the return-side pipe 41 downstream of the filter 65 in Fig. 13 during the plating process of the sample No. 11 of Example 2 And the sample liquid of Sample No. 25 to be measured is the plating liquid sampled from the same place during the plating process of Sample No. 13 of Example 2. [

The plating solutions to be measured of the samples Nos. 21 to 23 and the samples Nos. 26 to 28 were prepared in a beaker so that the dissolved oxygen concentration and the polishing agent concentration of the solution after preparation were the values of the respective samples of Tables 11 and 12.

THRU-CUP EVF-T manufactured by Uemura Kogyo Co., Ltd. was used as an additive of the plating solution to be measured of Sample Nos. 19 to 23, and THRU-CUP EVF- -CUP ETN "respectively.

As the VMS (plating liquid with no additive), the copper sulfate plating solution (containing 200 g / L of copper sulfate pentahydrate, 50 g / L of sulfuric acid and 50 mg / L of chloride ion) was used for Sample Nos. 19 to 23 of Table 11, For Sample Nos. 24 to 28 in Table 12, a copper sulfate plating solution (containing 100 g / L of copper sulfate pentahydrate, 200 g / L of sulfuric acid, and 50 mg / L of chloride ion) was used.

5) Measurement result

The measurement results are shown in Tables 11 and 12.

The measured Ar value reflects the magnitude of the concentration of the brightener. From Table 11, it can be seen that, in the case of the dissolved oxygen concentration and the concentration of the brightener which are appropriate as in the sample Nos. 20 and 21, the Ar value is about 1.14 to 1.16. If the dissolved oxygen concentration is insufficient even when the concentration of the brightener is proper as in Sample No. 19, the initial Ar value is about 1.2, which is almost the same as the case where the brightener concentration is excessive (Sample No. 22). The Ar value of the sample No. 19 decreased to about 1.15, which is almost the same as that of the sample No. 20, with the lapse of time.

It can be seen from Table 12 that the Ar value is about 1.97 in the case of the appropriate dissolved oxygen concentration and the brightener concentration as in the sample Nos. 25 and 26. If the dissolved oxygen concentration is excessive even when the concentration of the brightener is appropriate as in the sample No. 24, the initial Ar value is about 1.91 as in the case where the concentration of the brightener is insufficient (sample No. 28). The Ar value of this sample No. 24 increased to about 1.96, which is almost the same as that of the sample No. 25, with the lapse of time.

As in the samples Nos. 19 and 24, the Ar values close to the Ar values of the sample No. 20 and the sample No. 25, respectively, with the lapse of time, are due to the following. In other words, if sweeping is repeated continuously, air is dissolved in the measurement liquid, so that the dissolved oxygen concentration fluctuates as shown in Tables 11 and 12, and the concentration becomes close to a proper concentration. The reason why air is dissolved in the measurement liquid is that it is stirred by the rotating platinum electrode and that the dissolved oxygen concentration of VMS is close to the saturation concentration of air.

This application is based on Japanese Patent Application No. 2009-207286 filed on September 8, 2009, the contents of which are incorporated herein by reference.

Claims (18)

A plating bath in which a plating solution is stored; And
And a separate tank in which the plating liquid circulates between the plating tank and the plating tank, the plating tank being provided separately from the plating tank,
Wherein the separate bath has a first space and a second space located on the downstream side of the first space, and the second space is formed in the first space, And the plating liquid has a structure in which the plating liquid flows down in the air in the second space. The method according to claim 1,
Wherein the separate bath has vertically extending partition walls for dividing the first space and the second space and the plating liquid in the first space overflows the upper edge portion located at the predetermined height in the partition wall And the second space has a structure that flows into the second space. The method according to claim 1,
Wherein said separate vessel has a vertically extending partition wall for partitioning said first space and said second space, and said plating liquid in said first space is passed through said through-hole at said predetermined height in said partition wall, And the second plating layer is formed on the second plating layer. 3. The method of claim 2,
Wherein the upper edge portion of the partition wall has a protruding piece extending to the second space side, and the protruding piece has a distal end spaced apart from a side surface of the partition wall. 5. The method of claim 4,
Characterized in that the projecting piece has a transverse portion extending in the transverse direction and a longitudinal portion extending downward from the front end of the transverse portion on the side of the second space and the tip of the longitudinal portion being spaced apart from the side surface of the partition wall Device. 6. The method according to any one of claims 1 to 5,
Further comprising: a transfer side pipe for transferring the plating liquid from the plating bath to the separate bath;
The transfer-side pipe has a supply port for supplying the plating liquid to the first space;
And the supply port is located below the predetermined height. The method according to claim 6,
And the discharge direction of the plating liquid from the supply port is directed to the inner surface of the separate tank. 6. The method according to any one of claims 1 to 5,
Further comprising: a transfer side pipe for transferring the plating liquid from the plating bath to the separate bath;
The above-
A first partition wall extending in the vertical direction to divide the first space and the second space,
The first space is divided into a sedimentation space for sedimenting the metal particles in the plating solution and a supply space for supplying the plating solution from the supply port of the transporting pipe located on the upstream side of the sedimentation space and vertically And an elongated second bank. 9. The method of claim 8,
Wherein the second bank is provided below the predetermined height and has a plurality of communication holes communicating the settling space and the supply space. 9. The method of claim 8,
And an upper edge portion of the second bank is located below the predetermined height or the predetermined height. The method according to claim 1,
Further comprising a return side pipe returning the plating solution from the separate vessel to the plating bath and a re-supply pipe returning the plating solution discharged from the separated vessel to the first space. The method according to claim 1,
Further comprising a mechanical stirrer provided in a space on the downstream side of the first space. The method according to claim 1,
Wherein the plating bath has a bath main body in which the plating liquid is stored, and an overflow tank which is integrally provided with the bath main body and in which the plating liquid of the bath main body flows over the upper edge of the side wall of the bath main body;
This overflow tank has an upstream side space and a downstream side space located on the downstream side of the upstream side space and has a structure in which the plating liquid flows into the downstream side space from the upstream side space and flows down the air Wherein the electroplating apparatus is an electroplating apparatus. 14. The method of claim 13,
Wherein the upper edge of the bath main body has a projecting piece extending to the overflow trough and the projecting piece has a distal end spaced apart from the side surface of the bath main body. The method according to claim 1,
Wherein an amount of the plating solution flowing down in the air in the second space is 10 cm or more. The method according to claim 1,
Wherein the plating liquid is used for copper plating and contains a sulfur-containing organic compound as a brightening agent. An electroplating method using an electroplating apparatus having a plating bath in which a plating solution is stored and a separate bath in which the plating solution is circulated between the plating bath and a bath separate from the plating bath,
The separate vessel having a first space therein and a second space located downstream of the first space;
Storing the plating liquid to a predetermined height in the first space to precipitate metal particles in the plating liquid below the first space;
And the dissolved oxygen concentration of the plating solution is adjusted by causing the plating solution in the first space to flow into the second space in excess of the predetermined height and to flow the plating solution in the air in the second space. Electroplating method. 18. The method of claim 17,
Wherein the plating solution is used for copper plating and contains a sulfur-containing organic compound as a brightening agent.

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