WO2012133225A1

WO2012133225A1 - Electro copper plating additive and electro copper plating bath

Info

Publication number: WO2012133225A1
Application number: PCT/JP2012/057594
Authority: WO
Inventors: 内田　廣記; 啓規杉浦
Original assignee: 上村工業株式会社
Priority date: 2011-03-28
Filing date: 2012-03-23
Publication date: 2012-10-04
Also published as: CN103443334B; TWI608130B; JP2012201976A; TW201300581A; KR101940593B1; JP5363523B2; CN103443334A; US20130341199A1; KR20140013021A

Abstract

Provided is an electro copper plating additive which forms a uniform plating film from low current density parts to high current density parts, imparting a lustrous shine, and which is not depleted when the bath is not in use. Also provided is an electro copper plating bath containing the additive. The present invention involves adding an electric copper plating additive comprising a block polymer compound represented by general formula (1) below to an electro copper plating bath. (In the formula, R represents a straight-chain or branched-chain alkenyl group or alkyl group having 1 to 15 carbon atoms, m is an integer from 1 to 30, and n is an integer from 1 to 40.)

Description

Additive for electrolytic copper plating and electrolytic copper plating bath

The present invention relates to an additive for electrolytic copper plating and an electrolytic copper plating bath, and more particularly to an additive for electrolytic copper plating suitable as a brightener for a copper sulfate plating bath and an electrolytic copper plating bath containing the additive.
This application claims priority on the basis of Japanese Patent Application No. 2011-070667 filed on Mar. 28, 2011 in Japan. By referring to these applications, the present application Incorporated.

Conventionally, a bright copper plating film is provided by adding a brightening agent to an electrolytic copper plating bath. As the brightener, for example, an organic thio compound, an oxygen-containing polymer organic compound, and the like are known (see, for example, Patent Document 1 or 2). As organic thio compounds, disulfide compounds such as NaO ₃ SC ₃ H ₆ S—SC ₃ H ₆ SO ₃ Na are widely used, and as oxygen-containing polymer organic compounds, oxyalkylene polymers, polyethylene glycol, polypropylene glycol, etc. Is used.

Further, as brighteners other than the above compounds, the following general formula H- (EO) a- (PO) m- (EO) b-H
A polymer obtained by adding ethylene oxide to polypropylene glycol is used. In the above formula, EO represents an oxyethylene group, PO represents an oxypropylene group, and n = a + b.

However, these conventionally used brighteners are not sufficient in glossiness and throwing power in the low current density part of the copper plating film, and form a rough film. As a cause thereof, for example, in the polymer represented by the above general formula, in the molecular structure, (PO) m of the hydrophobic group is sandwiched between (EO) n on both sides, so that the effect as the hydrophobic group is weakened. This is probably because of this. As a result, when this polymer compound is used as a brightening agent for an electrolytic copper plating bath, the current distribution is disturbed in the low current density part and the high current density part, and uniform electrodeposition is hindered. Defective plating would occur, such as clouding.

Also, as a brightener for electrolytic copper plating, it is desired to be easy to manage and not to be consumed even when not in use.

JP 2005-194608 A JP 2008-297221 A

Therefore, the present invention has been made in view of the above-described conventional situation, and a uniform plating film is formed from a low current density portion to a high current density portion to give a good gloss, and is not good. An object of the present invention is to provide an additive for electrolytic copper plating that does not wear even during use, and an electrolytic copper plating bath containing the additive.

As a result of intensive studies in order to solve the above problems, the present inventors have used a block polymer compound having an enhanced effect of a hydrophobic group as an additive, so that a uniform from a low current density part to a high current density part can be obtained. It has been found that a good gloss can be imparted by forming a plating film, and the present invention has been completed.

That is, the additive for electrolytic copper plating according to the present invention comprises a block polymer compound represented by the following general formula (1).

(Wherein, R represents a linear or branched alkyl group or alkenyl group having 1 to 15 carbon atoms, m is an integer of 1 to 30, and n is an integer of 1 to 40.)

Further, the electrolytic copper plating bath according to the present invention contains an additive composed of a block polymer compound represented by the general formula (1).

According to the present invention, a uniform plating film can be formed from a low current density part to a high current density part to give a good gloss, and stable and good plating without being consumed even when not in use. A film can be formed.

Hereinafter, the electrolytic copper plating additive and the electrolytic copper plating bath containing the additive according to the present embodiment will be described in detail.

The additive for electrolytic copper plating according to the present embodiment is composed of a block polymer compound represented by the following general formula (1).

Here, in the general formula (1), R represents a linear or branched alkyl group or alkenyl group having 1 to 15 carbon atoms, m is an integer of 1 to 30, and n is an integer of 1 to 40.

Examples of R which is a linear or branched alkyl group or alkenyl group having 1 to 15 carbon atoms include, for example, methyl group, ethyl group, n-propyl group, allyl group, n-butyl group, n-pentyl group, n -Hexyl group, 1-methylhexyl group, 2-ethylhexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, Examples thereof include an n-tetradecyl group and an n-pentadecyl group.

Further, m and n in the general formula (1) can be appropriately set according to the type of R described above. Specifically, since the hydrophobicity increases as the carbon number of R increases, by adjusting the molar ratio of m and n according to the type of R, it is possible to have appropriate solubility in the plating bath. Can be. Further, m and n can be preferably set so that the molecular weight of the block polymer represented by the general formula (1) is 500 to 2,000.

As shown in the general formula (1), this additive has a structure in which the terminal on the oxypropylene group side is capped with an alkyl group or an alkenyl group. Thus, by capping the terminal of the oxypropylene group with an alkyl group or an alkenyl group, the effect of the oxypropylene group as a hydrophobic group can be enhanced.

Further, in the additive represented by the general formula (1), the order of the oxypropylene group (PO) and the oxyethylene group (EO) is constant, and R—O— (PO) m— (EO) n— It is a block polymer having a structure of H. As a result, the oxypropylene group ((PO) m) whose end is capped with an alkyl group or an alkenyl group as described above allows the portion of “RO— (PO) m” in the general formula (1) to be Collectively, it acts as a hydrophobic group and has high hydrophobicity.

As expected from this, the hydrophobic group of the compound is generally pushed out of the water to the interface, so when the object to be plated is immersed in an aqueous solution, the plating surface of the object becomes the interface, and the hydrophobicity is high. The additive having is concentrated on the plating surface, and the effect of the additive is enhanced. As a result, since the effect of the additive is exhibited throughout the low current density portion to the high current density portion, it is considered that a uniform plating film can be formed and good glossiness can be imparted.

Furthermore, by being such a block polymer, it can be made to have appropriate solubility by the oxyethylene group at the other end, and the polymer compound dissolves well in the electrolytic copper plating bath, and the plating bath It can be stably maintained inside, and can be prevented from being consumed with time when the electrolytic treatment is not used.

The block polymer compound represented by the general formula (1) can be produced, for example, by the following method. That is, in an inert gas atmosphere such as nitrogen gas, first, propylene oxide is added to an alkyl alcohol or alkenyl alcohol having 1 to 15 carbon atoms. After completion of the addition reaction of propylene oxide, it can be obtained by adding ethylene oxide and carrying out addition reaction of ethylene oxide.

As described above, the block polymer compound is synthesized by performing addition reaction of propylene oxide to alkyl alcohol or alkenyl alcohol having 1 to 15 carbon atoms and then adding addition reaction of ethylene oxide to form an alkyl group or alkenyl group. A block body having a certain structure in which (EO) n is added to capped (PO) m can be obtained.

The reaction temperature in the production method of the block polymer compound is not particularly limited, but is preferably 90 to 160 ° C. By setting the reaction temperature to 90 ° C. or higher, an appropriate reaction rate can be obtained and an addition reaction of propylene oxide and ethylene oxide can be efficiently generated. Moreover, the production | generation of a side reaction product etc. can be suppressed by making reaction temperature 160 degrees C or less, and the yield of the block polymer compound to produce | generate can be raised. In addition, when adding ethylene oxide after the addition reaction of propylene oxide to alkyl alcohol, after the addition reaction of propylene oxide at the above-mentioned 90 to 160 ° C., after cooling once, the ethylene oxide is subjected to the same temperature conditions. It is preferable to perform an addition reaction.

Further, the reaction time is not particularly limited, but varies depending on the reaction temperature, but is preferably within 15 hours in each addition reaction of propylene oxide and ethylene oxide. By making it within 15 hours, production of by-products and the like can be suppressed, and the yield of the block polymer compound to be produced can be increased.

The addition reaction is preferably carried out under pressure, and the pressure at the start of the addition reaction is preferably 2 to 5 kg / cm ² .

When the block polymer compound represented by the general formula (1) is used as an additive for electrolytic copper plating, the additive concentration at that time is preferably 0.05 to 1.0 g / L. By setting the additive concentration to 0.05 g / L or more, a plating film having sufficient gloss can be formed. In addition, by making the additive concentration 1.0 g / L or less, the effective current density range is prevented from narrowing, and a uniform plating film is formed uniformly from the low current density part to the high current density part. Can be made.

Next, an electrolytic copper plating bath to which an additive composed of the block polymer compound represented by the general formula (1) described above is added, and a plating process using the electrolytic copper plating bath will be described. The electrolytic copper plating bath is not particularly limited, but is particularly preferably a copper sulfate plating bath. Thus, by adding the block polymer compound described above to the copper sulfate plating bath, a copper plating film having excellent gloss can be uniformly formed in a wide current density range, and can be used for decorative plating treatment. It can use suitably as a plating bath to be used.

Specifically, the composition of the copper sulfate plating bath is, for example, a plating bath having a basic composition of 50 to 250 g / L of copper sulfate (Cu ₂ SO ₄ · 5H ₂ O) and 50 to 250 g / L of concentrated sulfuric acid. it can. The copper sulfate plating bath usually contains a trace amount (about 10 to 200 mg / L) of chloride ions. Specifically, for example, it can be contained by adding a water-soluble chloride such as NaCl.

In addition, glossiness and smoothness may be further improved by adding a known additive to the above-described electrolytic copper plating bath. Specifically, for example, organic thio compounds, organic acid amides, oxygen-containing polymer organic compounds, and the like can be added.

As a plating treatment condition using the above-described electrolytic copper plating bath, the pH is set to 1 or less. The plating temperature is preferably in the range of 20 to 50 ° C., and the cathode current density is preferably 0.1 to 8 A / dm ² . Moreover, a copper plate and an insoluble anode can be used as the anode. Furthermore, in order to form a plating film having more uniform gloss, it is preferable to sufficiently perform stirring such as air stirring and cathode locking.

In addition, the object to be plated to be subjected to the above-described plating treatment is not particularly limited, but for example, an electric to which the above-mentioned additives are added for the purpose of performing decorative plating on the object to be plated such as plastic. A copper plating bath can be suitably used. In addition, a plating process may be applied to a printed wiring board having a through hole or an electric / electronic component. Thus, the electrolytic copper plating bath to which the above-mentioned additive is added can be widely applied from a decorative use to a functional purpose.

Hereinafter, specific examples of the present invention will be described. Note that the present invention is not limited to any of the following examples.

In each example described below, a copper plating bath in which a block polymer (RO— (PO) m— (EO) n—H) shown in Table 1 was synthesized and the block polymer compound was added as an additive was prepared. Using this, plating treatment was performed, and the plating film formed by precipitation was evaluated. Note that air was blown into the copper plating bath and sufficiently stirred, and air was applied to the object to be plated so that the vicinity of the cathode was particularly stirred.

<Example 1>
(Synthesis of block polymer)
In an airtight reaction vessel, 600 g (10 mol) of n-propanol and 5.6 g (0.1 mol) of potassium hydroxide are taken, and 870 g (15 mol) of propylene oxide is added at 90 to 130 ° C. and 2 to 5 kg in a nitrogen gas atmosphere. The addition reaction was carried out under a pressure of / cm ² . After completion of the addition reaction of propylene oxide, the reaction vessel was cooled, and then 660 g (15 mol) of ethylene oxide was added to carry out the addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (KYOWARD 600, manufactured by Kyowa Chemical Industry Co., Ltd.) is added to the reaction vessel, followed by stirring at 70 ° C. for 30 minutes, followed by filtration to obtain polyoxyethylene (15) polyoxypropylene (15 ) 2070 g of propyl ether was obtained.

(Plating treatment and plating film evaluation)
Following composition Copper sulfate _{_{_{(Cu 2 SO 4 · 5H 2}}} O) 200g / L
Concentrated sulfuric acid 50g / L
NaCl 115mg / L
A copper sulfate plating solution comprising bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diethylsafranine diazotized product 50 mg / L, and polyoxy synthesized as described above Using a plating bath to which 0.2 g / L of ethylene (15) polyoxypropylene (15) propyl ether was added, plating treatment was performed using a Hull Cell tester at a total current of 2 A and time of 10 minutes. The plating conditions were pH <1, temperature 25 ° C., cathode current density 0.15 to 4 A / dm ² .

As a result, precipitates having good gloss from the low current density part to the high current density part could be uniformly formed.

In addition, even if the plating process is performed after leaving the copper plate in the above-described Hull Cell tester overnight, the precipitate having a good gloss should be uniformly formed as in the first plating process. I was able to. From this, it was found that the additive was stably maintained without being consumed in the plating bath even when not in use.

<Example 2>
(Synthesis of block polymer)
In an airtight reaction vessel, 580 g (10 mol) of allyl alcohol (2-propen-1-ol) and 5.6 g (0.1 mol) of potassium hydroxide are taken, and 870 g (15 mol) of propylene oxide is added in a nitrogen gas atmosphere. The addition reaction was performed at 90 to 130 ° C. under a pressure of 2 to 5 kg / cm ² . After completion of the addition reaction of propylene oxide, the reaction vessel was cooled, and then 660 g (15 mol) of ethylene oxide was added to carry out the addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (KYOWARD 600, manufactured by Kyowa Chemical Industry Co., Ltd.) is added to the reaction vessel, followed by stirring at 70 ° C. for 30 minutes, followed by filtration to obtain polyoxyethylene (15) polyoxypropylene (15 ) 2050 g of allyl ether was obtained.

(Plating treatment and plating film evaluation)
In Example 2, as additives, bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranin 50 mg / L, and polyoxyethylene (15 ) Plating was performed using a Hull cell tester in the same manner as in Example 1 except that a copper sulfate plating bath to which 0.2 g / L of polyoxypropylene (15) allyl ether was added was used.

As a result, precipitates having good gloss from the low current density part to the high current density part could be uniformly formed. In addition, even if the plating process is performed after leaving the copper plate in the above-described Hull Cell tester overnight, the precipitate having a good gloss should be uniformly formed as in the first plating process. I was able to.

<Example 3>
(Synthesis of block polymer)
In an airtight reaction vessel, 740 g (10 mol) of n-butanol and 5.6 g (0.1 mol) of potassium hydroxide are taken, and 580 g (10 mol) of propylene oxide is added at 90 to 130 ° C. and 2 to 5 kg in a nitrogen gas atmosphere. The addition reaction was carried out under a pressure of / cm ² . After completion of the addition reaction of propylene oxide, the reaction vessel was cooled, and then 660 g (15 mol) of ethylene oxide was added to carry out the addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (KYOWARD 600, manufactured by Kyowa Chemical Industry Co., Ltd.) is added to the reaction vessel, followed by stirring at 70 ° C. for 30 minutes, followed by filtration to obtain polyoxyethylene (15) polyoxypropylene (10 ) 1920 g of butyl ether was obtained.

(Plating treatment and plating film evaluation)
In Example 3, as additives, bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranin 50 mg / L, and polyoxyethylene ( 15) Plating was performed using a Hull cell tester in the same manner as in Example 1 except that a copper sulfate plating bath to which 0.2 g / L of polyoxypropylene (10) butyl ether was added was used.

<Example 4>
(Synthesis of block polymer)
In an airtight reaction vessel, 1020 g (10 mol) of n-hexanol and 5.6 g (0.1 mol) of potassium hydroxide are taken, and 290 g (5 mol) of propylene oxide is 90 to 130 ° C. and 2 to 5 kg in a nitrogen gas atmosphere. The addition reaction was carried out under a pressure of / cm ² . After completion of the addition reaction of propylene oxide, the reaction vessel was cooled, and then 880 g (20 mol) of ethylene oxide was added to cause addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (KYOWARD 600, manufactured by Kyowa Chemical Industry Co., Ltd.) is added to the reaction vessel, followed by stirring at 70 ° C. for 30 minutes, followed by filtration to obtain polyoxyethylene (20) polyoxypropylene (5 ) 2130 g of hexyl ether was obtained.

(Plating treatment and plating film evaluation)
In Example 4, as additives, bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranin 50 mg / L, and polyoxyethylene (as described above) ( 20) Plating was performed using a Hull cell tester in the same manner as in Example 1 except that a copper sulfate plating bath added with 0.2 g / L of polyoxypropylene (5) hexyl ether was used.

<Example 5>
(Synthesis of block polymer)
In an airtight reaction vessel, 1300 g (10 mol) of 2-ethylhexanol and 5.6 g (0.1 mol) of potassium hydroxide are taken, and 174 g (3 mol) of propylene oxide is added at 90 to 130 ° C. under a nitrogen gas atmosphere. The addition reaction was carried out under a pressure of 5 kg / cm ² . After completion of the addition reaction of propylene oxide, the reaction vessel was cooled, and then 1100 g (25 mol) of ethylene oxide was added to cause addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (KYOWARD 600, manufactured by Kyowa Chemical Industry Co., Ltd.) is added to the reaction vessel, followed by stirring at 70 ° C. for 30 minutes, followed by filtration to obtain polyoxyethylene (25) polyoxypropylene (3 ) 2500 g of 2-ethylhexyl ether was obtained.

(Plating treatment and plating film evaluation)
In Example 5, as additives, bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranin 50 mg / L, and polyoxyethylene (as described above) ( 25) Plating was performed using a Hull cell tester in the same manner as in Example 1 except that a copper sulfate plating bath to which 0.2 g / L of polyoxypropylene (3) 2-ethylhexyl ether was added was used.

<Example 6>
(Synthesis of block polymer)
In an airtight reaction vessel, 1860 g (10 mol) of 1-dodecanol and 5.6 g (0.1 mol) of potassium hydroxide are taken, and 116 g (2 mol) of propylene oxide is added at 90 to 130 ° C. and 2 to 5 kg in a nitrogen gas atmosphere. The addition reaction was carried out under a pressure of / cm ² . After completion of the addition reaction of propylene oxide, the reaction vessel was cooled, and then 1320 g (30 mol) of ethylene oxide was added to carry out the addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (KYOWARD 600, manufactured by Kyowa Chemical Industry Co., Ltd.) is added to the reaction vessel, followed by stirring at 70 ° C. for 30 minutes, followed by filtration to obtain polyoxyethylene (30) polyoxypropylene (2 ) 3200 g of dodecyl ether was obtained.

(Plating treatment and plating film evaluation)
In Example 6, as additives, bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranine 50 mg / L, and polyoxyethylene ( 30) Plating was performed using a Hull cell tester in the same manner as in Example 1 except that a copper sulfate plating bath to which 0.2 g / L of polyoxypropylene (2) dodecyl ether was added was used.

<Comparative Example 1>
(Plating treatment and plating film evaluation)
In Comparative Example 1, copper sulfate to which bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranin 50 mg / L, and polyethylene glycol 0.2 g / L were added as additives. Except for using a plating bath, the plating treatment was performed using a Hull cell tester in the same manner as in Example 1 to evaluate the deposited plating film. In Comparative Example 1 and Comparative Examples 2 and 3 below, air was blown into the copper plating bath and sufficiently stirred.

As a result, the precipitate had a good gloss, but fine pits and white cloudiness occurred, and a uniform precipitate was not formed from the low current density portion to the high current density portion, resulting in a poor appearance. It was a plating film.

<Comparative Example 2>
(Plating treatment and plating film evaluation)
In Comparative Example 2, copper sulfate to which bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranin 50 mg / L, and polypropylene glycol 0.2 g / L were added as additives. Except that a plating bath was used, the plating treatment was performed using a Hull cell tester in the same manner as in Example 1 to evaluate the deposited plating film.

<Comparative Example 3>
(Plating treatment and plating film evaluation)
In Comparative Example 3, the additive was obtained by adding ethylene oxide to bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diazotized product of diethyl safranin 50 mg / L, and polypropylene glycol. Other than using a copper sulfate plating bath to which 0.2 g / L of a block polymer (H- (EO) a- (PO) m- (EO) b-H, m = 17, n = a + b = 9) was added In the same manner as in Example 1, plating treatment was performed using a Hull cell tester, and the deposited plating film was evaluated.

<Comparative example 4>
(Plating treatment and plating film evaluation)
In Comparative Example 4, bis- (ω-sulfopropyl) -disulfide disodium salt 10 mg / L, diethylsafranine diazotized product 50 mg / L, and ethylene oxide and propylene oxide in n-butanol were used as additives. Except for using a copper sulfate plating bath to which 0.2 g / L of a random polymer obtained by addition at the same time was used, plating was performed using a Hull cell tester in the same manner as in Example 1 to form a precipitate. The plating film was evaluated.

As a result, although the deposit had a good gloss, it became a stepped plating that changed into a step shape and deposited, and the plating was not deposited at the low current density portion, and the plating film had a poor appearance. .

Claims

The additive for electrolytic copper plating which consists of a block polymer compound shown by following General formula (1).

(Wherein, R represents a linear or branched alkyl group or alkenyl group having 1 to 15 carbon atoms, m is an integer of 1 to 30, and n is an integer of 1 to 40.)
The block polymer compound is obtained by subjecting an addition reaction of propylene oxide to an alkyl alcohol or alkenyl alcohol having 1 to 15 carbon atoms in an inert gas atmosphere, followed by addition reaction of ethylene oxide. Item 4. The additive for electrolytic copper plating according to Item 1.
An electrolytic copper plating bath containing the additive for electrolytic copper plating according to claim 1.