KR101940593B1 - Electro copper plating additive and electro copper plating bath - Google Patents

Abstract

(단, 식 중, R은 직쇄 또는 분지쇄의 탄소수 1∼15의 알킬기 또는 알케닐기를 나타내고, m은 1∼30의 정수이고, n은 1∼40의 정수이다).Provided is an additive for copper electroplating which forms a uniform plating film from a low current density portion to a high current density portion to give good gloss and is not consumed even when not used, and an electroplating bath containing the additive. In the present invention, a copper electroplating additive comprising a block polymer compound represented by the following general formula (1) is added to an electroplating bath.
[Chemical 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).

Description

TECHNICAL FIELD [0001] The present invention relates to an additive for electroplating and an electroplating bath for electroplating,

TECHNICAL FIELD The present invention relates to an additive for copper electroplating and an electroplating bath, and more particularly to an electroplating bath containing an additive for electroplating and a additive for electroplating, which is preferable as a polisher of a copper sulfate plating bath. The present application claims priority based on Japanese Patent Application No. 2011-070667, filed on March 28, 2011, in Japan, and is hereby incorporated by reference in its entirety.

Conventionally, a polishing agent is added to the copper electroplating bath to give a glossy copper plating film. As such a 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 the organic thio compound, a disulfide compound such as NaO ₃ SC ₃ H ₆ S-SC ₃ H ₆ SO ₃ Na is commonly used, and as the oxygen-containing polymer organic compound, an oxyalkylene polymer, a polyethylene glycol, a polypropylene glycol And so on.

Further, as a glossing agent other than the above-mentioned compounds,

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 luster and uniform throwing power at the low current density portion of the copper-plated film, and a coarse film is formed. As a cause, for example, in the polymer represented by the above general formula, since the (PO) m of the hydrophobic group is present between (EO) n on both sides in the molecular structure, the effect as a hydrophobic group is weakened And that it is becoming. As a result, when a compound comprising this polymer is used as a brightener in an electroplating bath, the current distribution is disturbed in the low-current density portion and the high-current density portion, which hinders uniform electrodeposition and causes fine pits And bad plating occurred.

Further, as a polishing agent for electroplating, it is required to be easy to manage and to not be consumed even when not used.

Japanese Patent Application No. 2005-194608 Japanese Patent Application No. 2008-297221

SUMMARY OF THE INVENTION The present invention has been made in order to solve the conventional problems as described above, and it is an object of the present invention to provide a plating film having uniform plating from a low current density portion to a high current density portion to give good glossiness, And a copper electroplating bath containing the additive for the copper electroplating and the additive thereof.

The present inventors have conducted intensive studies to solve the above problems. As a result, they have found that by using a block polymer compound having an effect of a short period of time as an additive, a uniform plating film is formed from a low current density portion to a high current density portion The present invention has been accomplished on the basis of these findings.

That is, the additive for copper electroplating according to the present invention is composed of the block polymer compound represented by the following general formula (1).

[Chemical 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 copper electroplating bath according to the present invention contains an additive comprising the block polymer compound represented by the above general formula (1).

According to the present invention, a uniform plating film can be formed from a low current density portion to a high current density portion to give good glossiness, and a good plating film can be stably formed without being consumed even when not used.

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

The additive for copper electroplating according to this embodiment is composed of the block polymer compound represented by the following general formula (1).

(2)

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 C1-C15 alkyl or alkenyl group, include a methyl group, ethyl group, n-propyl group, allyl group, n-butyl group, n- N-heptyl, n-heptyl, n-heptyl, n-heptyl, n-octyl, Decyl group, n-pentadecyl group, and the like.

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

As indicated by the above general formula (1), the additive has a structure in which the terminal of 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, the additive represented by the general formula (1) has a structure in which the order of the oxypropylene group (PO) and the oxyethylene group (EO) is constant and is always composed of RO- (PO) m- (EO) nH Block polymer. As a result, the oxypropylene group ((PO) m) whose terminal is capped with an alkyl group or an alkenyl group as described above, together with the moiety "RO- (PO) m" in the general formula (1) So that it has high hydrophobicity.

As a predicted action from this fact, generally, the hydrophobic group of the compound is pushed from the water to the interface, so that when the object to be plated is immersed in the aqueous solution, the plated surface of the object to be plated becomes the interface, Is concentrated on the plated surface, and the effect of the additive is enhanced. As a result, it is considered that since the effect of the additive is exerted throughout the range from the low current density portion to the high current density portion, a uniform plating film can be formed and good gloss can be given.

Further, because of such a block polymer, the oxyethylene group at the other end can provide more appropriate solubility, and the polymer compound can be dissolved well in the electroplating bath and can be stably maintained in the plating bath And can be suppressed from being consumed over time in the unused electrolytic treatment.

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

As described above, the block polymer compound can be produced by subjecting propylene oxide to an addition reaction with an alkyl alcohol or alkenyl alcohol having 1 to 15 carbon atoms, (EO) < n > is added.

The reaction temperature in the process for producing a block polymer compound is not particularly limited, but is preferably 90 to 160 캜. By setting the reaction temperature at 90 占 폚 or higher, an appropriate reaction rate can be obtained, and the addition reaction of propylene oxide and ethylene oxide can be efficiently performed. By setting the reaction temperature to 160 占 폚 or lower, generation of side reactants and the like can be suppressed and the yield of the resulting block polymer compound can be increased. When ethylene oxide is added after the addition reaction of propylene oxide to the alkyl alcohol, an addition reaction of propylene oxide at 90 to 160 캜 as described above, followed by cooling once, and then addition reaction of ethylene oxide under the same temperature condition .

The reaction time is not particularly limited and varies depending on the reaction temperature, but is preferably within 15 hours in the addition reaction of propylene oxide and ethylene oxide. Within 15 hours, generation of side reactants and the like can be suppressed, and the yield of the resulting block polymer compound can be increased.

In the addition reaction, it is preferable to carry out the reaction 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 above general formula (1) is used as an additive for electroplating, it is preferable that the addition concentration is 0.05 to 1.0 g / L. By setting the addition concentration to 0.05 g / L or more, a plating film having sufficient luster can be formed. Further, by setting the addition concentration to 1.0 g / L or less, it is possible to effectively prevent the narrowing of the usable current density range, and to form a good plating film uniformly from the low current density portion to the high current density portion.

Next, an electroplating bath to which an additive comprising the block polymer compound represented by the above-mentioned general formula (1) is added, and a plating process using the electroplating bath will be described. The copper electroplating bath is not particularly limited, but is preferably copper sulfate plating bath. By adding the above-mentioned block polymer compound to the copper sulfate plating bath in this way, it is possible to form a copper-plated coating film having uniform and excellent glossiness over a wide range of current density, It can be preferably used as a plating bath.

Specifically, as the composition (composition) of the copper sulfate plating bath, for example, a plating solution containing 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 You can make a bath. The copper sulfate plating bath usually contains a trace amount (about 10 to 200 mg / L) of chloride ion. Specifically, it can be contained, for example, by adding a water-soluble chloride such as NaCl.

Further, it is possible to further improve the gloss and smoothness by adding an additive to the above-mentioned copper electroplating bath. Specifically, for example, organic thio compounds, organic acid amides, oxygen-containing high molecular organic compounds, and the like can be added.

As the plating treatment conditions using the above-mentioned copper electroplating bath, the pH is set to 1 or less. Further, the plating temperature is in the range of 20~50 ℃, and the cathode current density is preferably set to 0.1~8 A / dm ^2. As the anode, a copper plate and an insoluble anode can be used. Further, in order to form a plating film having a more uniform luster, it is preferable to sufficiently stir the air, the cathodic rock and the like.

The plating treatment to which the above-described plating treatment is performed is not particularly limited. For example, for the purpose of decorative plating on a plating treatment material such as plastic, A plating bath can be preferably used. In addition, plating processing may be performed on a printed wiring board having through holes, electric / electronic parts, and the like. As described above, the copper electroplating bath to which the above-described additives are added can be widely applied from decorative use to functional use.

[Example]

Hereinafter, a specific embodiment of the present invention will be described. The present invention is not limited to any one of the following examples.

In each of the examples described below, a block polymer (RO- (PO) m- (EO) nH) shown in Table 1 was synthesized, and a copper plating bath in which the block polymer compound was added as an additive was used for plating , And the plating film on which the precipitation was formed was evaluated. Then, air was blown into the copper plating bath to sufficiently stir, and in particular, air was brought into contact with the object to be plated so that the vicinity of the cathode was stirred.

[Table 1]

≪ Example 1 >

(Synthesis of block polymer)

870 g (15 moles) of propylene oxide was reacted at 90 to 130 占 폚 in an amount of 2 to 5 kg / hr in a nitrogen gas atmosphere by using 600 g (10 mol) of n-propanol and 5.6 g cm < ^{2 &} gt ;. 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, followed by addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (Kyoward 600, manufactured by Kyoe Kagaku Kogyo K.K.) was added to the reaction vessel, and the mixture was stirred at 70 ° C for 30 minutes and then filtered to obtain polyoxyethylene (15) polyoxypropylene (15) propyl ether (2070 g).

(Plating treatment and evaluation of plating film)

The following composition

Copper sulfate (Cu ₂ SO ₄ .5H ₂ O) 200 g / L

Concentrated sulfuric acid 50 g / L

NaCl 115 mg / L

10 mg / L bis (ω-sulfopropyl) -disulfide disodium salt, 50 mg / L Diazotization product of diethyl sapranin as an additive, and 50 mg / And a plating bath containing 0.2 g / L of polyoxyethylene (15) polyoxypropylene (15) propyl ether was used, and the plating treatment was carried out using a Hallex tester at a total current of 2 A for 10 minutes. The plating conditions were pH <1, temperature 25 ° C, and cathode current density 0.15-4 A / dm ² .

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

In addition, even when the plating treatment was performed by the same method after leaving the copper plate in the above-described walcel tester for one night and then performing plating treatment in the same manner, it was possible to uniformly form precipitates having good gloss as in the initial plating treatment. From these facts, it has been found that the additive is stably held in the plating bath even when not used.

&Lt; Example 2 >

(Synthesis of block polymer)

870 g (15 moles) of propylene oxide was dissolved in 90 g of n-butanol in an airtight reaction vessel under nitrogen gas atmosphere using 580 g (10 mol) of allyl alcohol (2-propen-1-ol) and 5.6 g And the addition reaction was carried out under a pressure of ~130 ° C and 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, followed by addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (Kyoward 600, manufactured by Kyoe Kagaku Kogyo K.K.) was added to the reaction vessel, and the mixture was stirred at 70 ° C for 30 minutes and then filtered to obtain polyoxyethylene (15) polyoxypropylene (15) 2050 g of allyl ether was obtained.

(Plating treatment and evaluation of plating film)

In Example 2, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt, 50 mg / L diazotization product of diethyl sapranin and 50 mg / L of bis Except that a copper sulfate plating bath to which 0.2 g / L of polyoxyethylene (15) polyoxypropylene (15) allyl ether was added was used, and a plating treatment was carried out using a whisker tester in the same manner as in Example 1.

As a result, precipitates having good luster from the low current density portion to the high current density portion could be uniformly formed. In addition, even when the plating treatment was performed by the same method after leaving the copper plate in the above-described walcel tester for one night and then performing plating treatment in the same manner, it was possible to uniformly form precipitates having good gloss as in the initial plating treatment.

&Lt; Example 3 >

(Synthesis of block polymer)

580 g (10 moles) of propylene oxide was reacted at 90 to 130 占 폚 and 2 to 5 kg / cm2 in an atmosphere of nitrogen gas by employing 740 g (10 moles) of n-butanol and 5.6 g cm &lt; ^{2 &} gt ;. 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, followed by addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (Kyoward 600, manufactured by Kyoe Kagaku Kogyo K.K.) was added to the reaction vessel, and the mixture was stirred at 70 ° C for 30 minutes and then filtered to obtain polyoxyethylene (15) polyoxypropylene (10) 1920 g of butyl ether was obtained.

(Plating treatment and evaluation of plating film)

In Example 3, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt, 50 mg / L diazotization product of diethyl sapranin and 50 mg / L of bis , And polyoxyethylene (15) polyoxypropylene (10) Butyl ether (0.2 g / L) was used instead of the copper sulfate plating bath.

As a result, precipitates having good luster from the low current density portion to the high current density portion could be uniformly formed. In addition, even when the plating treatment was performed by the same method after leaving the copper plate in the above-described walcel tester for one night and then performing plating treatment in the same manner, it was possible to uniformly form precipitates having good gloss as in the initial plating treatment.

<Example 4>

(Synthesis of block polymer)

(10 moles) of n-hexanol and 5.6 g (0.1 mole) of potassium hydroxide were charged in an airtight reaction vessel and 290 g (5 moles) of propylene oxide was reacted at 90 to 130 DEG C and 2 to 5 kg / cm &lt; ^{2 &} gt ;. 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, followed by addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (Kyoward 600, manufactured by Kyoe Kagaku Kogyo K.K.) was added to the reaction vessel, and the mixture was stirred at 70 ° C for 30 minutes and then filtered to obtain polyoxyethylene (20) polyoxypropylene (5) hexyl ether (2130 g).

(Plating treatment and evaluation of plating film)

In Example 4, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt, 50 mg / L diazotization product of diethyl sapranin and 50 mg / L of bis , And polyoxyethylene (20) polyoxypropylene (5) hexyl ether (0.2 g / L) was used instead of the copper sulfate plating bath.

As a result, precipitates having good luster from the low current density portion to the high current density portion could be uniformly formed. In addition, even when the plating treatment was performed by the same method after leaving the copper plate in the above-described walcel tester for one night and then performing plating treatment in the same manner, it was possible to uniformly form precipitates having good gloss as in the initial plating treatment.

&Lt; Example 5 >

(Synthesis of block polymer)

174 g (3 moles) of propylene oxide was reacted at 90 to 130 캜, 2 to 5 캜 (3 mol), and the mixture was reacted under a nitrogen gas atmosphere with 1300 g (10 mols) of 2-ethylhexanol and 5.6 g kg / cm &lt; ^{2 &} gt ;. 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, followed by addition reaction under the same conditions.

Next, 50 g of synthetic adsorbent (Kyoward 600, manufactured by Kyoe Kagaku Kogyo K.K.) was added to the reaction vessel, and the mixture was stirred at 70 ° C for 30 minutes and then filtered to obtain polyoxyethylene (25) polyoxypropylene (3) 2500 g of 2-ethylhexyl ether was obtained.

(Plating treatment and evaluation of plating film)

In Example 5, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt, 50 mg / L diazotization product of diethyl sapranin and 50 mg / L of bis , And polyoxyethylene (25) polyoxypropylene (3) A copper sulfate plating bath to which 0.2 g / L of 2-ethylhexyl ether was added was used to conduct a plating treatment using a whisker tester in the same manner as in Example 1.

As a result, precipitates having good luster from the low current density portion to the high current density portion could be uniformly formed. In addition, even when the plating treatment was performed by the same method after leaving the copper plate in the above-described walcel tester for one night and then performing plating treatment in the same manner, it was possible to uniformly form precipitates having good gloss as in the initial plating treatment.

&Lt; Example 6 >

(Synthesis of block polymer)

1860 g (10 moles) of 1-dodecanol and 5.6 g (0.1 mole) of potassium hydroxide were used in an airtight reaction vessel and 116 g (2 moles) of propylene oxide was reacted at 90 to 130 캜 and 2 to 5 kg / cm &lt; ^{2 &} gt ;. 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, followed by addition reaction under the same conditions.

Next, 50 g of a synthetic adsorbent (Kyoward 600, manufactured by Kyoe Kagaku Kogyo K.K.) was added to the reaction vessel, and the mixture was stirred at 70 ° C for 30 minutes and then filtered to obtain polyoxyethylene (30) polyoxypropylene (2) 3200 g of dodecyl ether was obtained.

(Plating treatment and evaluation of plating film)

In Example 6, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt, 50 mg / L diazotization product of diethyl sapranin and 50 mg / L of bis , And polyoxyethylene (30) polyoxypropylene (2) plating was carried out using a whisker tester in the same manner as in Example 1, except that a copper sulfate plating bath to which 0.2 g / L of dodecyl ether was added was used.

As a result, precipitates having good luster from the low current density portion to the high current density portion could be uniformly formed. In addition, even when the plating treatment was performed by the same method after leaving the copper plate in the above-described walcel tester for one night and then performing plating treatment in the same manner, it was possible to uniformly form precipitates having good gloss as in the initial plating treatment.

&Lt; Comparative Example 1 &

(Plating treatment and evaluation of plating film)

In Comparative Example 1, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt, 50 mg / L diazo processed diethyl sapranin, and 0.2 g / L polyethylene glycol Except that a copper sulfate plating bath was used in the same manner as in Example 1, plating treatment was carried out using a whisker tester to evaluate the deposited plating film. Also in this Comparative Example 1 and the following Comparative Examples 2 and 3, air was blown into the copper plating bath and sufficiently stirred.

As a result, the precipitate had a good gloss, but fine pits were formed or white was blurred, so that a uniform precipitate from the low current density portion to the high current density portion was not formed, and the coating film had a poor appearance.

&Lt; Comparative Example 2 &

(Plating treatment and evaluation of plating film)

In Comparative Example 2, 10 mg / L bis (ω-sulfopropyl) -disulfide disodium salt, 50 mg / L diazotization product of diethylsulfanine and 0.2 g / L polypropylene glycol Except that a copper sulfate plating bath to which a copper sulfate plating solution was added was used in place of the copper sulfate plating bath.

As a result, the precipitate had good gloss, but fine pits were generated or clouded to white, so that a uniform precipitate from the low current density portion to the high current density portion was not formed, and the plating film had a poor appearance.

&Lt; Comparative Example 3 &

(Plating treatment and evaluation of plating film)

In Comparative Example 3, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt, 50 mg / L diazotization product of diethyl sapranin, and ethylene oxide were added to polypropylene glycol Except that a copper sulfate plating bath to which 0.2 g / L of the block polymer (H- (EO) a- (PO) m- (EO) bH, m = 17, n = a + Similarly, the plating treatment was carried out using a whisker tester to evaluate the deposited plating film.

As a result, the precipitate had good gloss, but fine pits were generated or clouded to white, so that a uniform precipitate from the low current density portion to the high current density portion was not formed, and the plating film had a poor appearance.

&Lt; Comparative Example 4 &

(Plating treatment and evaluation of plating film)

In Comparative Example 4, 10 mg / L bis (-? - sulfopropyl) -disulfide disodium salt and 50 mg / L diazotization product of diethyl sapranin as an additive and 50 mg / Except that a copper sulfate plating bath to which 0.2 g / L of a random polymer obtained by adding propylene oxide at the same time was used was used in the same manner as in Example 1, and the plating film formed by precipitation was evaluated.

As a result, although the precipitate had a good gloss, it became a step (plating) plating which changed stepwise, and the plating was not precipitated at the low current density portion, and became a plating film having a poor appearance.

Claims (3)

A polish agent for copper electroplating comprising a block polymer compound represented by the following general formula (1)
The block polymer compound is obtained by subjecting propylene oxide to an addition reaction with an alkyl alcohol or alkenyl alcohol having 1 to 15 carbon atoms in an inert gas atmosphere and then carrying out an addition reaction with ethylene oxide,
[Chemical 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). An electric copper plating bath containing the polishing agent for copper electroplating according to claim 1. delete