TW201816199A - Soluble copper anode, electrolytic copper plating device, electrolytic copper plating method, and method for preserving acidic electrolytic copper plating liquid - Google Patents

Abstract

In order to provide a soluble copper anode, an electrolytic copper plating device, an electrolytic copper plating method, and a method for preserving acidic electrolytic copper plating liquid that can stably suppress the generation of anode sludge, there is employed, as a soluble copper anode used for electrolytic copper plating, a soluble copper anode characterized by including a titanium case that accommodates a copper material, and an iridium oxide member that is in contact with the titanium case. At least the surface of the iridium oxide member is made of an iridium oxide simplex or an iridium oxide complex, whereby the generation of anode sludge is suppressed without causing a reduction in plating characteristics.

Description

   Soluble copper anode, electrolytic copper plating device, electrolytic copper plating method and storage method of acidic electrolytic copper plating solution   

The invention relates to a soluble copper anode, an electrolytic copper plating device, an electrolytic copper plating method, and a preservation method of an acidic electrolytic copper plating solution.

Conventionally, electrolytic copper plating has been used to form copper circuits in printed circuit boards and the like. This electrolytic copper plating has become a method of damascene plating also used for wafers in recent years, and it is also expected that TSV (Through Silicon Via) and TGV (Through Glass Via) etc. application. Furthermore, regarding electrolytic copper plating, plating technologies such as via filling and through-hole filling have also been gradually established, but they need to be improved.

When electrolytic copper plating is performed, as the anode, there are a method using a soluble anode including a copper material, and a method including an insoluble anode such as platinum, titanium, and indium oxide. Here, in the case where electrolytic copper plating is performed using a soluble anode, compared with the case where electrolytic copper plating is performed using an insoluble anode, the equipment is simple and does not cost maintenance costs, and the anode itself is relatively inexpensive, thereby achieving cost reduction. Furthermore, in the case of electrolytic copper plating using a soluble anode, as in the case of using an insoluble anode, the problem of poor plating due to the influence of additives in the plating solution by anodic oxidation does not occur. Therefore, when electrolytic copper plating is performed, it is now normal to use a soluble anode.

However, in the case of electrolytic copper plating using a soluble anode, a large amount of anode mud containing metallic copper and copper oxide is generated due to the heterogeneous reaction of monovalent copper ions when the anode is dissolved, and plating has the ability to uniformly plate, etc. Degradation.

In order to solve this problem, for example, the method disclosed in Japanese Patent No. 5694111 uses an agent or a device to reduce the amount of anode slime. Specifically, in Japanese Patent No. (License No. 5659411), the production of anode sludge is suppressed by adding alkanes and olefins to an electrolytic copper plating solution using phosphorous copper as an anode.

However, in the method disclosed in Japanese Patent No. 5694111, the concentration management of the additives is complicated, and it is difficult to maintain the effect of stably maintaining the effect of suppressing the generation of anode sludge. In addition, the addition of these additives promotes the dissolution of the copper anode, causes an increase in the copper concentration in the plating solution, and causes problems such as a decrease in the uniform plating ability and deterioration of the plating appearance.

From the above, it is understood that the present invention aims to provide a soluble copper anode, an electrolytic copper plating device, an electrolytic copper plating method, and a storage method of an acidic electrolytic copper plating solution that can stably suppress the generation of anode sludge.

As a result of intensive studies, the present inventors have completed the present invention by adopting the following methods to achieve the above-mentioned objects.

The soluble copper anode of the present invention is a soluble copper anode used for electrolytic copper plating, and is characterized in that it includes a titanium case containing a copper material and an indium oxide member in contact with the titanium case.

In the soluble copper anode of the present invention, the shape of the copper material is preferably spherical.

In the soluble copper anode of the present invention, the aforementioned copper material is preferably a phosphorus-containing copper material.

The plating solution in the aforementioned electrolytic copper plating using a soluble copper anode of the present invention is preferably an acidic electrolytic copper plating solution containing a disulfide compound.

It is preferable that the soluble copper anode of the present invention further includes an anode bag covering the periphery of the titanium case and the indium oxide member.

In the soluble copper anode of the present invention, the area ratio of the surface of the copper material and the indium oxide member immersed in the acidic electrolytic copper plating solution is preferably 1000: 10 to 1000: 200.

In the soluble copper anode of the present invention, it is preferable that the material of at least the surface of the indium oxide member is indium oxide or an indium oxide composite.

In the soluble copper anode of the present invention, it is preferable that the indium oxide member is coated on the surface of a substrate including any one of titanium, zirconium, stainless steel, and nickel alloy with an indium oxide or indium oxide composite.

In the soluble copper anode of the present invention, it is preferable that 30 to 70% of the indium oxide composite system indium oxide is mixed with any one or a plurality of materials of tantalum oxide, titanium oxide, and platinum.

In the soluble copper anode of the present invention, the shape of the substrate is preferably any of a mesh, a sheet, a tube, a plate, a wire, a rod, and a sphere.

The electrolytic copper plating device of the present invention is characterized by including the above-mentioned soluble copper anode.

In the electrolytic copper plating method of the present invention, a DC current or a PPR current is used when electrolytic copper plating is performed on an object to be plated by using the above-mentioned electrolytic copper plating device.

In the electrolytic copper plating method of the present invention, it is preferable to use a printed circuit board or a wafer as the object to be plated.

The method for preserving an acidic electrolytic copper plating solution of the present invention is a method for preserving a soluble copper anode contained in the structure of a titanium shell containing a copper material in the acidic electrolytic copper plating solution, and is characterized in that at least during the stop of the electrolysis This titanium shell is in contact with the indium oxide member.

The soluble copper anode, the electrolytic copper plating device, the electrolytic copper plating method, and the storage method of the acidic electrolytic copper plating solution of the present invention can effectively suppress the generation of anode slime, and can achieve stable improvement of plating characteristics. Furthermore, according to the storage method of the acidic electrolytic copper plating solution of the present invention, the dissolution of the copper material of the soluble copper anode is suppressed even when the electrolysis is stopped, and the generation of anode sludge can be effectively suppressed.

1‧‧‧ soluble copper anode

2‧‧‧ Copper

3‧‧‧ titanium case

4‧‧‧ Indium oxide component

5‧‧‧Anode Bag

10‧‧‧plating tank

11‧‧‧Acid electrolytic copper plating bath

20‧‧‧Plating objects

FIG. 1 is a schematic cross-sectional view illustrating a case where the soluble anode of the present invention is used in an electrolytic copper plating apparatus.

FIG. 2 is a sectional photograph illustrating the filling state of the hole in Example 1. FIG.

FIG. 3 is a sectional photograph illustrating the filling condition of the hole in Example 2. FIG.

FIG. 4 is a sectional photograph illustrating the filling condition of the hole in Example 3. FIG.

FIG. 5 is a sectional photograph illustrating the filling condition of the hole in Example 4. FIG.

FIG. 6 is a sectional photograph illustrating the filling condition of the hole in Example 5. FIG.

FIG. 7 is a sectional photograph illustrating the filling condition of the hole in Example 6. FIG.

FIG. 8 is a sectional photograph illustrating the filling condition of the hole in Comparative Example 1. FIG.

FIG. 9 is a cross-sectional photographic view illustrating a filling condition of a hole in Comparative Example 2. FIG.

FIG. 10 is a cross-sectional photographic view illustrating the filling condition of a hole in Comparative Example 3. FIG.

Hereinafter, the soluble copper anode, the electrolytic copper plating apparatus, the electrolytic copper plating method, and the electrolytic copper plating liquid storage method of the present invention will be described using drawings. FIG. 1 is a schematic cross-sectional view illustrating a soluble anode used in an electrolytic copper plating apparatus according to the present invention.

The electrolytic copper plating device of the present invention includes the soluble copper anode of the present invention. The soluble copper anode is used for electrolytic copper plating, and is characterized in that it includes a titanium case 3 accommodating a copper material 2 and an indium oxide member 4 in contact with the titanium case 3. These structures are described below.

The copper material 2 constituting the soluble copper anode 1 used in the soluble copper anode of the present invention is used to generate copper ions during electrolysis and is used to coat the surface of the plated member 20 with copper. The copper material 2 is preferably spherical. When the shape of the copper material 2 is spherical, the surface area of the copper anode can be extremely large, and more copper ions are generated during electrolysis to further improve the plating efficiency.

Furthermore, the copper material 2 constituting the soluble copper anode of the present invention is preferably a phosphorus-containing copper material. When a phosphorus-containing copper member is used for the soluble copper anode, a film of a Cu ₂ P compound called a "black film" is formed on the surface of the phosphorus-containing copper member during electrolysis to suppress the production of monovalent copper ions and the production of anode sludge. . In order to further suppress the production of anode sludge of the phosphorus-containing copper member, the content of phosphorus is preferably about 0.02% to 0.06%. The phosphorus-containing copper material used for the soluble copper anode 1 is advantageous in that copper can be dissolved smoothly during electrolysis.

The titanium case 3 constituting the soluble copper anode of the present invention may be any shape as long as the copper material 2 can be maintained in a state of being immersed in the plating solution 11. For example, it can be used for forming a plurality of holes (sieve mesh) on the sidewall. . The length of the titanium shell 3 is related to the surface area of the copper material 2. For example, when electrolytic copper plating is performed on the surface of a substrate of a predetermined size (1.0m × 1.0m) at a mass production site, use approximately 60mm × (1100 ~ 1300) mm titanium case. The length and number of the titanium shells 3 are based on the current density of the cathode and anode used, and the thickness distribution of the copper plating coated on the surface of the plated member 20. The titanium shell 3 of the present invention can be used by a wide range of users and is not particularly limited.

In the indium oxide member 4 constituting the soluble copper anode of the present invention, it is preferable that the material of at least the surface is an indium oxide monomer or an indium oxide composite. The soluble copper anode includes the indium oxide members 4 configured as described above, which suppresses the generation of anode sludge and does not cause degradation of plating characteristics. Here, the indium oxide member 4 may be a surface of a base material including any of titanium, zirconium, stainless steel, and a nickel alloy, and may include a coating material containing indium oxide. The base material of the indium oxide member 4 is preferably a material that does not dissolve due to electrolysis as described above. Therefore, the indium oxide composite is preferably 30% to 70% of indium oxide mixed with any one or plural materials of tantalum oxide, titanium oxide, and platinum. These include coatings containing an indium oxide composite, which can be used as electrodes to further improve durability and oxygen generation effects.

Furthermore, in the soluble copper anode of the present invention, the shape of the base material of the indium oxide member 4 is preferably any of a mesh, a sheet, a tube, a plate, a wire, a rod, and a sphere. In addition, considering the size of the indium oxide member 4 to suppress the generation of anode slime, it is preferable to use a titanium shell length in addition to the spherical shape. Since the indium oxide member 4 has a shape and size that do not interfere with the dissolution of the soluble copper anode during electrolysis, the monovalent copper ions generated near the indium oxide member 4 can be instantly converted into divalent copper ions to suppress the anode slime. generate.

Furthermore, the soluble copper anode of the present invention preferably includes an anode bag 5 covering the periphery of the titanium case 3 and the indium oxide member 4. Since this soluble copper anode further includes an anode bag 5, the copper material 2 accommodated in the titanium case 3 is stably maintained under an oxidizing atmosphere, and it is possible to effectively convert one-valent copper ions, which is the cause of the mud, into divalent copper ions. Further, the soluble copper anode includes an anode bag 5 to prevent the formed anode slime from diffusing in the plating solution 11 and prevent the plating characteristics from being lowered. The anode bag 5 can be used by a wide range of users, and the shape, material, and the like are not particularly limited.

The plating solution 11 used in the electrolytic copper plating apparatus of the present invention uses an acidic copper plating solution. Usually, the system contains copper sulfate. Copper sulfate plating solution for pentahydrate, sulfuric acid, chloride ion and additives. For example, the composition of the acidic copper plating solution 11 may be copper sulfate. Pentahydrate is used in the range of 30 g / L to 250 g / L, sulfuric acid 30 g / L to 250 g / L, and chloride ion 30 mg / L to 75 mg / L. The temperature of the acidic copper plating solution 11 can be generally used in the range of 15 ° C to 60 ° C, and preferably 25 ° C to 35 ° C. Copper sulfate. The concentration of pentahydrate increased, or accompanied by the increase of sulfuric acid, copper sulfate. Since the pentahydrate is precipitated on the copper anode, attention must be paid to the concentration management of both.

Here, the acid copper plating solution 11 used in the electrolytic copper plating apparatus of the present invention is preferably one containing a disulfide. In recent years, when electrolytic copper plating is performed, as a brightener component, for example, bis (3-sulfopropyl) disulfide (hereinafter, simply referred to as "SPS") is used. However, in this case, the change to 3-mercaptopropane-1-sulfonic acid (hereinafter referred to as "MPS") through the SPS results in a reduction in the uniform plating ability and poor plating appearance in the perforated bath. Problems such as a decrease in filling rate and poor plating appearance occurred. In particular, when the electrolysis is stopped and the acid copper plating solution 11 is left, it is confirmed that the SPS near the anode is reduced to generate MPS. The formation of MPS also causes the generation of anode sludge containing MPS-Cu ⁺ complex. However, in the case of using the soluble copper anode 1 of the present invention, by preventing the generation of MPS due to the decomposition of SPS, the generation of anode sludge can be suppressed, the bad effects of MPS can be eliminated, and the problems described above will not occur.

As described above, when the soluble copper anode 1 including the anode bag 5 is used, MPS in the anode bag 5 may be present in a very high concentration. As a result, the indium oxide member 4 is in contact with the titanium shell 3 filled with the copper material 2 to be electrolyzed, and MPS may be rendered extremely harmless.

From the viewpoint of suppressing the generation of MPS, the area ratio of the surface of the copper material 2 and the indium oxide member 4 impregnated with the acidic electrolytic copper plating solution 11 is preferably 1000: 10 to 1000: 200. When the area ratio of the copper material 2 and the indium oxide member 4 on the surface impregnated with the acidic electrolytic copper plating solution 11 is less than 1000: 10, since the generation of oxygen from the surface of the indium oxide member 4 is extremely small, the generation of MPS cannot be effectively suppressed. When the area ratio exceeds 1000: 200, oxygen generation from the surface of the indium oxide member 4 is significantly increased, and the additives in the plating solution 11 are oxidatively decomposed, thereby increasing the consumption of the additives. Therefore, the area ratio is preferably 1000: 50 to 1000: 100, and more preferably 1000: 75 to 1000: 125. If necessary, in order to adjust the surface area of the indium oxide member 4 immersed in the acidic electrolytic copper plating solution 11, a mask such as silicon rubber may be used.

In addition, in the electrolytic copper plating device of the present invention, the range of the cathode current density applicable is generally a range of phosphorous copper materials used for plating of printed circuit boards. Specifically, the cathode current density is about 0.1 A / dm ² to 10 A / dm ² , preferably 0.5 A / dm ² to 6 A / dm ² , and more preferably 1 A / dm ² to 5 A / dm ² . The anode current density can usually be used from 0.1 A / dm ² to 3 A / dm ² , preferably from 1 A / dm ² to 3 A / dm ² . The copper concentration in the acid copper plating solution 11 tends to increase when the anode current density is too low, and tends to decrease when the anode current density is too high. It is necessary to adjust the anode area according to the cathode current density used.

Here, when the soluble copper anode of this invention is used, the effect which can be acquired at the time of electrolysis stop and electrolysis is described. In general, when the electrolytic copper plating bath 11 is stopped from being electrolytically placed, dissolution occurs as shown in the following formula (1) and formula (2) through contact corrosion of the copper material 2 and the titanium shell 3. When the acid copper plating solution 11 contains a disulfide compound, the SPS is reduced to generate MPS by the electrons emitted at this time as shown in the formula (3) below. Therefore, the MPS concentration in the acid copper plating solution 11 increases. The generated MPS is converted into SPS by partial acidification as shown in the formula (4) of the following formula 1, and Cu (I) MPS combined with a monovalent copper ion becomes the MPS of the formula (5) of the following formula 1.

Cu → Cu ⁺ + e. ． ． (1)

Cu ⁺ → Cu ²⁺ + e. ． ． (2)

^{SPS + 2H + + 2e - →} 2MPS. ． ． (3)

4MPS + 2Cu ²⁺ → 2Cu (I) MPS + SPS + 4H ⁺ . ． ． (4)

^{2Cu (I) MPS + H +} + e - → 2Cu + 2MPS. ． ． (5)

The above-mentioned chemical formula 1 is the cause of poor plating appearance when the electrolysis is stopped. Although the process of dissolving the copper material 2 and the formation of MPS is shown, the soluble copper anode of the present invention is constituted so that the titanium shell 3 and the indium oxide containing the copper material 2 are contained. The corrosion potential of the copper material 2 which is in contact with the member 4, in contact with the titanium shell 3 and indirectly in contact with the indium oxide member 4 can be lower than that of the copper material 2 alone, and the copper material 2 can be inhibited from dissolving in the acid electrolytic copper plating solution 11. As a result, it is possible to suppress the dissolution of the copper material 2 while the electrolysis is stopped, and to suppress the generation of MPS.

In addition, during electrolysis, the indium oxide member 4 of the present invention is in contact with the titanium shell 3, and the surface of the indium oxide member 4 during electrolysis generates oxygen in a highly active generation period, so that the periphery of the titanium shell 3 becomes an oxidizing atmosphere, and monovalent copper ions Conversion to divalent copper ions can suppress the formation of anode sludge containing CuCl, Cu ₂ O, etc.

From the above, it can be known that the electrolytic copper plating device of the present invention includes the soluble copper anode 1 of the present invention, and at the same time the plating efficiency is improved, a high-quality plating film can be formed at low cost.

The electrolytic copper plating method of the present invention is characterized by using the above-mentioned electrolytic copper plating device and using a DC current or a PPR (pulse periodic reverse) current when electrolytic copper plating is performed on the plating object 20.

In the copper plating method of the present invention, in the case where a direct current is used when the electrolytic copper plating treatment is performed on the plating target 20, generally used conditions can be suitably adopted. For example, when a DC current is used when electrolytic copper plating is performed, a DC current that can obtain a certain stable current value can be used. As a means for obtaining a direct current, a three-phase full-wave rectifier (ripple 5% or less) can be used.

Furthermore, in the copper plating method of the present invention, a PPR current may be used when the electrolytic copper plating process is performed on the object to be plated 20. Here, the "PPR current" means that forward electrolysis (electrolysis that deposits plating) and reverse electrolysis are repeated in a short period, and the direction of the current is a current that periodically changes in a pulse waveform. According to the PPR current, a high resistance to over-voltage, which cannot be obtained with a DC current, can ensure a high plating uniformity. Therefore, it is most suitable for filling a perforated substrate with a high aspect ratio (plate thickness / aperture) and filling a hole with a small depth. When using a PPR current, the period of the current can be arbitrarily set, and it is preferable that the positive electrolysis time is longer than the reverse electrolysis time. For example, the positive electrolysis time is preferably from 0.1 msec to 50 msec, and more preferably from 1 msec to 20 msec. The reverse electrolysis time is preferably from 0.1 msec to 5 msec, and more preferably from 0.5 msec to 2 msec.

Furthermore, in the copper plating method of the present invention, it is preferable to use a printed circuit board or a wafer as the above-mentioned plating object 20. The printed circuit board usually achieves electrical connection between layers through a through hole, a blind hole (BVH), and the like. The perforation, for example, is widely used 0.15mm to 2.8mm, plate thickness 0.6mm to 3.2mm. Furthermore, in general, the blind hole system has a pore diameter of about 20 μm to 200 μm and a depth of about 10 μm to 100 μm. In the semiconductor wafer, a damascene plating method formed by copper sulfate plating of copper wiring with excellent conductivity is used. In this method, submicron holes and trenches on a semiconductor wafer are plated with copper sulfate and filled. Such stable hole filling needs to suppress the generation of MPS by using the decomposition of SPS as a brightener component, but the copper plating method of the present invention can effectively suppress such SPS deterioration.

The method for preserving an acidic electrolytic copper plating solution of the present invention is a method for preserving an acidic electrolytic copper plating solution 11 impregnated in a soluble copper anode 1 constituting a titanium shell 3 containing a copper material 2, which is characterized in While stopped, the titanium shell 3 is brought into contact with the indium oxide member 4. At least during the electrolysis stop, the titanium shell 3 and the indium oxide member 4 are brought into contact. As described above, the generation of monovalent copper ions during the electrolysis stop and the use of SPS in the plating solution can suppress the generation of MPS. Therefore, according to the storage method of the acidic electrolytic copper plating solution of the present invention, when the acidic copper plating solution 11 is left for a long period of time and directly used to start electrolysis, the appearance of the plating is not easy to occur, and maintenance-free is achieved.

Although the soluble copper anode, the electrolytic copper plating device, the electrolytic copper plating method, and the acidic electrolytic copper plating liquid storage method of the present invention have been described above, the examples of the present invention shown below explain the present invention in more detail. . The present invention is not limited in any way by these examples.

    [Example 1]    

In Example 1, a test was performed to confirm the hole filling condition when electrolytic copper plating was performed while the titanium case filled with the phosphorus-containing copper anode was in contact with the indium oxide member. Hereinafter, it demonstrates using FIG.

In the first embodiment, first, a plated member (printed substrate) 20 having a plate thickness of 1.0 mm, a hole diameter of 100 μm, and a depth of 80 μm is subjected to a metal inlay process through the Melplate MLB-6001 Process (Meltex Corporation). Next, electroless copper plating was performed through the Melplate CU-390 Process (Meltex Co., Ltd.). Then, after this printed circuit board 20 was degreased with Melplate CL-1000S (Meltex Co., Ltd.), washed with water, 10% sulfuric acid, and washed with water, electrolytic copper plating was performed under the conditions shown below.

The acidic copper plating solution 11 used in Example 1 was used in a plating solution containing copper sulfate and pentahydrate concentration of 220 g / L, sulfuric acid 50 g / L, and chloride ion 50 mg / L. Lucent Copper SVF-A ( Melex Co., Ltd., disulfide system) 0.8mL / L, Lucent Copper SVF-B (Meltex Co., Ltd.) 20mL / L, Lucent Copper SVF-L (Meltex Co., Ltd.) 15mL / L adjusted 1.5L Holes fill the bath. Then, the soluble copper anode 1 is arranged in the plating tank 10 in a state of being immersed in the hole filling bath 11 accommodated therein. Soluble copper anode 1 25 phosphorous copper balls 5) 2 titanium shells ( 30mm × 150mm) 3 and indium oxide member (rod coated with oxidation factor ( 5mm × 100mm)) 4 contact. Furthermore, it further includes an anode bag 5 covering the periphery of the titanium case 3 and the indium oxide member 4. The difference from the structure shown in FIG. 1 is that in Example 1, the soluble copper anode 1 was impregnated into two groups.

In Example 1, the area ratio between the surface of the copper material 2 and the indium oxide member 4 immersed in the acidic electrolytic copper plating solution 11 was 1000: 100. As the cathode, a 5 mm × 130 mm electroless copper-plated printed substrate 20 was immersed in the acid copper plating solution 11 so as to have a thickness of 1 dm ² . For this, electrolysis was performed at a current density of 2 A / dm ² until the amount of electrolysis was 5 AH / L, and then it was left overnight. The plating solution was left overnight after electrolysis, and the additives were analyzed and adjusted by the CVS method, and plating was performed at 2 A / dm ^{2 for} 15 μm. After plating, observe the filling condition of the holes by cross-section method.

FIG. 2 is a sectional photograph showing the filling condition of the hole in Example 1. FIG. Here, FIG. 2 (a) is a cross-sectional photograph when electrolysis is performed until the electrolysis amount becomes 5AH / L. In addition, FIG. 2 (b) is a photograph showing a cross-section when electrolytic copper plating is performed again using a plating solution that is left overnight after electrolysis. From Fig. 2 (a) and (b), the filling condition of the hole in Example 1 was used for electrolysis until the electrolysis amount became 5AH / L. The electroplating solution was left for one night after electrolysis and electrolytic copper plating was not observed. To change specially. The evaluation results performed in Example 1 are shown in Table 1.

    [Example 2]    

In Example 2, a test was performed in the same manner as in Example 1 to confirm the hole filling condition when electrolytic copper plating was performed while the titanium case filled with the phosphorus-containing copper anode was in contact with the indium oxide member.

In the second embodiment, the same plated member 20 as in the first embodiment is used. In Example 2, the same conditions as in Example 1 were performed before electrolytic copper plating was performed. Then, electrolytic copper plating was performed under the conditions shown below.

The acidic copper plating solution 11 used in Example 2 was used in a plating solution containing copper sulfate and pentahydrate concentration 150 g / L, sulfuric acid 150 g / L, and chloride ion 50 mg / L, and adjusted to add Lucent Copper HCS -A (Meltex Corporation, disulfide system) 0.3mL / L, Lucent Copper HCS-B (Meltex Corporation) 15mL / L, Lucent Copper HCS-L (Meltex Corporation) 6mL / L Adjust 1.5L of semi-filled bath for flexible substrate. Then, the soluble copper anode 1 is arranged in the plating tank 10 in a state of being immersed in the semi-filled bath 11 for the flexible substrates stored therein. The soluble copper anode 1 used here has the same structure as that used in Example 1.

In Example 2, the area ratio of the surface of the copper material 2 and the indium oxide member 4 immersed in the acidic electrolytic copper plating solution 11 was 1000: 100 as in Example 1. In addition, as in Example 1, a printed circuit board 20 subjected to electroless copper plating of 5 mm × 130 mm was used as a cathode, and was immersed in an acid copper plating solution 11 so as to have a thickness of 1 dm ² . This was electrolyzed at a current density of 3 A / dm ² until the amount of electrolysis was 5 AH / L, and then left to stand overnight. The plating solution was left overnight after electrolysis, and the additives were analyzed and adjusted by the CVS method to plate 15 μm at 3 A / dm ² . After plating, the filling condition of the holes was observed by the cross-section method.

FIG. 3 is a sectional photograph showing the filling condition of the hole in Example 2. FIG. Here, FIG. 3 (a) is a cross-sectional photograph when electrolysis is performed until the electrolysis amount becomes 5AH / L. In addition, FIG. 3 (b) is a cross-sectional photograph when electrolytic copper plating is performed again using a plating solution that is left overnight after electrolysis. From Figures 3 (a) and (b), the filling conditions of the holes in Example 2 are used for electrolysis until the electrolysis amount reaches 5AH / L. When the electroplating solution is left for one night after electrolysis, copper electroplating is not performed. Special changes were observed. The evaluation results performed in Example 2 are shown in Table 1.

    [Example 3]    

In Example 3, a test was performed in the same manner as in Example 1 to confirm the hole filling condition when electrolytic copper plating was performed while the titanium case filled with the phosphorus-containing copper anode was in contact with the indium oxide member.

In this Example 3, the same plated member 20 as in Example 1 was used. In addition, in Example 3, before performing electrolytic copper plating, the same processing was performed under the same conditions as in Example 1. Then, electrolytic copper plating was performed under the conditions shown below.

The acid copper plating solution 11 used in Example 3 was the same as that used in Example 1. The soluble copper anode 1 used in Example 3 was the same as that of Example 1 except that an indium oxide-coated plate (20 mm × 120 mm × 1 mm) was used as the indium oxide member 4.

In Example 3, the area ratio of the surface of the copper material 2 and the indium oxide member 4 immersed in the acidic electrolytic copper plating solution 11 was 1000: 200 as in Example 1. Then, as in Example 1, a printed circuit board 20 that was subjected to electroless copper plating of 5 mm × 130 mm as a cathode was immersed in an acid copper plating solution 11 so as to have a thickness of 1 dm ² . This was electrolyzed under the same conditions as in Example 1. After plating, the hole filling condition was observed by a cross-section method.

FIG. 4 is a sectional photograph showing the filling condition of the hole in Example 3. FIG. Here, FIG. 4 (a) is a cross-sectional photograph when electrolysis is performed until the electrolysis amount becomes 5AH / L. In addition, FIG. 4 (b) shows a cross-sectional photograph when electrolytic copper plating is performed again using a plating solution that is left overnight after electrolysis. From Figures 4 (a) and (b), the filling condition of the holes in Example 3 is that when the electrolysis is performed until the amount of electrolysis reaches 5AH / L, the electroplating solution is left for one night after electrolysis and copper electroplating is not performed. Special changes were observed. The evaluation results performed in Example 3 are shown in Table 1.

    [Example 4]    

In Example 4, a test was performed in the same manner as in Example 1 to confirm the hole filling condition when electrolytic copper plating was performed while the titanium case filled with the phosphorus-containing copper anode was in contact with the indium oxide member.

In the fourth embodiment, the same plated member 20 as in the first embodiment is used. In addition, in Example 4, the same processing was performed under the same conditions as in Example 1 before electrolytic copper plating was performed. Then, electrolytic copper plating was performed under the conditions shown below.

The acid copper plating solution 11 used in Example 4 was the same as that used in Example 1. In addition, as the soluble copper anode 1 used in Example 4, except for the wire coated with IrO ₂ -Pt (0.3) ( 1 mm × 120 mm) was used as the indium oxide member 4 except that the same structure as in Example 1 was used.

In Example 4, the area ratio of the surface of the copper material 2 and the indium oxide member 4 immersed in the acidic electrolytic copper plating solution 11 was 1000: 10. Then, as in Example 1, a printed circuit board 20 that was subjected to electroless copper plating of 5 mm × 130 mm as a cathode was immersed in an acid copper plating solution 11 so as to have a thickness of 1 dm ² . This was electrolyzed under the same conditions as in Example 1. After plating, the hole filling condition was observed by a cross-section method.

FIG. 5 is a sectional photograph showing the filling condition of the hole in Example 4. FIG. Here, FIG. 5 (a) is a sectional photograph when electrolysis is performed until the amount of electrolysis becomes 5AH / L. In addition, FIG. 5 (b) is a cross-sectional photograph when electrolytic copper plating is performed again using a plating solution that is left overnight after electrolysis. From Figures 5 (a) and (b), the filling condition of the holes in Example 4 is that when the electrolysis is performed until the amount of electrolysis reaches 5AH / L, the electroplating solution is left for one night after electrolysis and copper electroplating is not performed. Special changes were observed. The evaluation results performed in Example 4 are shown in Table 1.

    [Example 5]    

In Example 5, a test was performed in the same manner as in Example 1 to confirm the hole filling condition when electrolytic copper plating was performed while the titanium case filled with the phosphorus-containing copper anode was in contact with the indium oxide member.

In this fifth embodiment, the same plated member 20 as in the first embodiment is used. In Example 5, the same conditions as in Example 1 were performed before electrolytic copper plating. Then, electrolytic copper plating was performed under the conditions shown below.

The acid copper plating solution 11 used in Example 5 was the same as that used in Example 1. The soluble copper anode 1 used in Example 5 was the same as that used in Example 1 except that a plate (10 mm × 120 mm × 1 mm) coated with IrO ₂ -TiO ₂ (0.7) was used. Constructor.

In Example 5, the area ratio between the surface of the copper material 2 and the indium oxide member 4 immersed in the acidic electrolytic copper plating solution 11 was 1000: 100 as in Example 1. In addition, as in Example 1, a printed circuit board 20 subjected to electroless copper plating of 5 mm × 130 mm was used as a cathode, and was immersed in an acid copper plating solution 11 so as to have a thickness of 1 dm ² . This was electrolyzed under the same conditions as in Example 1. After plating, the hole filling condition was observed by a cross-section method.

FIG. 6 is a sectional photograph showing the filling condition of the hole in Example 5. FIG. Here, FIG. 6 (a) is a cross-sectional photograph when electrolysis is performed until the electrolysis amount becomes 5AH / L. In addition, FIG. 6 (b) shows a cross-sectional photograph when electrolytic copper plating is performed again using a plating solution that is left overnight after electrolysis. From Figures 6 (a) and (b), the filling condition of the holes in Example 5 is that when the electrolysis is performed until the amount of electrolysis reaches 5AH / L, the electroplating solution is left for one night after electrolysis and the copper plating is not performed again. Special changes were observed. The evaluation results performed in Example 5 are shown in Table 1.

    [Example 6]    

In Example 6, a test was performed in the same manner as in Example 1 to confirm the hole filling condition when electrolytic copper plating was performed while the titanium case filled with the phosphorus-containing copper anode was in contact with the indium oxide member.

In this sixth embodiment, the same plated member 20 as in the first embodiment is used. In Example 6, before electrolytic copper plating was performed, the same treatment was performed under the same conditions as in Example 1. Then, electrolytic copper plating was performed under the conditions shown below.

The acid copper plating solution 11 used in Example 6 was the same as that used in Example 1. The soluble copper anode 1 used in Example 6 was the same as that used in Example 1 except that a plate (5 mm × 100 mm × 1 mm) coated with IrO ₂ -Ta ₂ O ₅ (0.3) was used. For the same constituents.

In Example 6, the area ratio between the surface of the copper material 2 and the indium oxide member 4 immersed in the acidic electrolytic copper plating solution 11 was 1000: 50. In addition, as in Example 1, a printed circuit board 20 subjected to electroless copper plating of 5 mm × 130 mm was used as a cathode, and was immersed in an acid copper plating solution 11 so as to have a thickness of 1 dm ² . This was electrolyzed under the same conditions as in Example 1. After plating, the hole filling condition was observed by a cross-section method.

FIG. 7 is a sectional photograph showing the filling condition of the hole in Example 6. FIG. Here, FIG. 7 (a) is a cross-sectional photograph when electrolysis is performed until the electrolysis amount becomes 5AH / L. In addition, FIG. 7 (b) is a photograph showing a cross-section when electrolytic copper plating is performed again using a plating solution that has been left overnight after electrolysis. From (a) and (b) of Fig. 7, the filling conditions of the holes in Example 6 were used for electrolysis until the electrolysis amount became 5AH / L. Special changes were observed. The evaluation results performed in Example 5 are shown in Table 1.

    [Comparative Example 1]    

In Comparative Example 1, a test was performed to confirm the hole filling condition when electrolytic copper plating was performed in a state where the titanium case filled with the phosphorus-containing copper anode was not in contact with the indium oxide member.

In Comparative Example 1, the test was performed under the same conditions as in Example 1 except that a test was performed to confirm that electrolytic copper plating was performed in a state where the titanium case filled with the phosphorus-containing copper anode was not in contact with the indium oxide member, and was omitted here. Instructions.

FIG. 8 is a cross-sectional photograph showing the filling state of the hole in Comparative Example 1. FIG. Here, FIG. 8 (a) is a cross-sectional photograph when electrolysis is performed until the electrolysis amount becomes 5AH / L. In addition, FIG. 8 (b) shows a cross-sectional photograph when electrolytic copper plating is performed again using a plating solution that is left overnight after electrolysis. From Figs. 8 (a) and (b), the filling conditions of the pores in Comparative Example 1 were compared with the case where electrolysis was performed until the electrolysis amount became 5AH / L. It was observed that electrolysis was performed again by using a plating solution that was left overnight after electrolysis. The filling condition of the holes during copper plating is significantly deteriorated. The evaluation results of Comparative Example 1 are shown in Table 1.

    [Comparative Example 2]    

In Comparative Example 2, a test was performed in the same manner as in Comparative Example 1 to confirm the hole filling condition when electrolytic copper plating was performed in a state where the titanium case filled with the phosphorus-containing copper anode was not in contact with the indium oxide member.

In Comparative Example 2, the test was performed under the same conditions as in Example 2 except that electrolytic copper plating was performed in a state where the titanium case filled with the phosphorus-containing copper anode was not in contact with the indium oxide member, and the description is omitted here.

FIG. 9 is a cross-sectional photograph showing the filling condition of the hole in Comparative Example 2. FIG. Here, FIG. 9 (a) is a cross-sectional photograph when electrolysis is performed until the electrolytic amount becomes 5AH / L. In addition, FIG. 9 (b) shows a cross-sectional photograph when electrolytic copper plating is performed again using a plating solution that is left overnight after electrolysis. From Figs. 9 (a) and (b), the filling conditions of the pores in Comparative Example 2 are compared with the case where electrolysis is performed until the amount of electrolysis reaches 5AH / L. It is observed that the electrolysis is performed again by using a plating solution that is left overnight after electrolysis The filling condition of the holes during copper plating is significantly deteriorated. The evaluation results performed in Comparative Example 2 are shown in Table 1.

    [Comparative Example 3]    

In Comparative Example 3, a test was performed in the same manner as in Comparative Example 1 to confirm the hole filling condition when electrolytic copper plating was performed in a state where the titanium case filled with the phosphorus-containing copper anode was not in contact with the indium oxide member.

In Comparative Example 3, 5 g / L of maleic acid was added to the hole-filling bath disclosed in Japanese Patent No. 5659411 to perform electrolytic copper plating, except that the titanium case filled with the phosphorous copper anode was not in contact with the indium oxide member. Except that the test was performed under the same conditions as in Example 1, the description is omitted here.

FIG. 10 is a cross-sectional photograph showing the filling state of the hole in Comparative Example 3. Here, FIG. 7 (a) is a cross-sectional photograph when electrolysis is performed until the electrolysis amount becomes 5AH / L. In addition, FIG. 7 (b) is a photograph showing a cross-section when electrolytic copper plating is performed again using a plating solution that has been left overnight after electrolysis. From Figs. 7 (a) and (b), the filling conditions of the pores in Comparative Example 2 are compared with the case where the electrolysis amount is 5AH / L. The filling condition of the holes during copper plating is significantly deteriorated. The evaluation results performed in Comparative Example 3 are shown in Table 1.

From the above results, it can be seen that the soluble copper anode used in electrolytic copper plating has a structure in which a titanium case containing a copper material is in contact with an indium oxide member, suppresses the dissolution of the copper material during the electrolysis stop, and suppresses the generation of MPS. From this, it can be understood that in the case of electrolytic copper plating using a soluble copper anode in contact with a titanium case containing a copper material and an indium oxide member, the occurrence of anode sludge is suppressed, and the adverse effects of MPS can be effectively eliminated.

    [Industrial availability]    

According to the soluble copper anode, the electrolytic copper plating device, the electrolytic copper plating method, and the storage method of the acidic electrolytic copper plating solution of the present invention, the generation of anode sludge can be stably suppressed. Furthermore, since the soluble copper anode of the present invention can be used from a structure widely used in the past to house phosphorus-containing copper balls in a titanium case, it is economical without introducing new equipment.

Claims (14)

    A soluble copper anode, which is a soluble copper anode used in electrolytic copper plating, is characterized in that it includes a titanium case containing a copper material and an indium oxide member in contact with the titanium case.         For example, the soluble copper anode according to the scope of patent application No. 1 wherein the shape of the copper material is spherical.         For example, the soluble copper anode of item 1 or 2 of the patent application scope, wherein the copper material is a phosphorus-containing copper material.         For example, the soluble copper anode according to the scope of application for the first item of the patent, wherein the plating solution used for the electrolytic copper plating is an acidic electrolytic copper plating solution containing a disulfide compound.         For example, the soluble copper anode according to the first patent application scope further includes an anode bag covering the titanium shell and the periphery of the indium oxide member.         For example, the soluble copper anode of item 1 of the patent application scope, wherein the area ratio of the surface of the copper material and the indium oxide member immersed in the acidic electrolytic copper plating solution is 1000: 10 to 1000: 200.         For example, the soluble copper anode of item 1 of the patent application scope, wherein the material of at least the surface of the indium oxide member is indium oxide or an indium oxide composite.         For example, a soluble copper anode according to item 7 of the application, wherein the indium oxide member is preferably covered on the surface of a substrate including any one of titanium, zirconium, stainless steel, and nickel alloy with an indium oxide or indium oxide composite. .         For example, the soluble copper anode of item 7 or 8 of the patent application scope, wherein the indium oxide composite system is 30 to 70% mixed with any one or plural materials of tantalum oxide, titanium oxide, and platinum.         For example, the soluble copper anode of item 8 or 9 of the scope of patent application, wherein the shape of the substrate is any one of a screen, a sheet, a tube, a plate, a wire, a rod, and a sphere.         An electrolytic copper plating device is characterized by including a soluble copper anode in the first scope of the patent application.         An electrolytic copper plating method is characterized in that it uses an electrolytic copper plating device according to item 11 of the scope of patent application, and uses DC current or PPR current when electrolytic copper plating is performed on the object to be plated.         For example, the electrolytic copper plating method according to item 12 of the application, wherein the object to be plated is a printed circuit board or a wafer.         A method for preserving an acidic electrolytic copper plating solution, which is a method for preserving a soluble copper anode contained in a structure of a titanium shell containing a copper material in the acidic electrolytic copper plating solution. The titanium shell is in contact with the indium oxide member.