JP2010189733A - Additive for pr pulse electrolytic copper plating, and copper plating liquid for periodic reverse pulse electrolytic plating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an additive for a copper plating liquid to be used for a PR (periodic reverse) pulse electrolysis technique capable of improving the plating appearance, physical properties of the plating film, filling property and the like when electrolytic copper plating is carried out by supplying a PR pulse current. <P>SOLUTION: The additive for the copper plating liquid to be used for the PR pulse electrolysis technique includes at least one kind of component selected from a group consisting of alkenes and alkynes. The copper plating liquid for the PR pulse electrolysis process includes an aqueous solution containing copper ions and at least one kind of acid component selected from organic acids and inorganic acids, as a basic plating bath, and further contains the additive. A copper plating method by the PR pulse electrolysis technique is provided, in which electrolytic copper plating is carried out on an object to be plated as a cathode in the copper plating liquid by supplying a PR pulse current. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an additive for a copper plating solution used in a PR pulse electrolysis method, a copper plating solution for plating by a PR pulse electrolysis method containing the additive, and a copper plating method by a PR pulse electrolysis method.

  In recent years, with the increase in functionality and speed of electronic devices, higher density is also required for printed wiring boards. A build-up process is indispensable for increasing the density of printed wiring boards, and via filling is an important plating technology.

  Conventionally, in such a build-up process, a non-through via is uniformly plated and then filled with an insulating resin or conductive paste to form a circuit. In this method, a via is formed on the via. It cannot be formed, and the degree of freedom in circuit design is taken away. For this reason, in recent years, a method of stacking wiring layers by performing via filling in which via holes are filled with copper plating has been adopted.

  Similarly, through-hole filling technology has recently been studied. This method is generally used for the core layer of the build-up board. Previously, uniform plating was applied to the through-holes and filled with insulating resin, and then copper sulfate plating and etching were performed again to form a circuit. . However, since this process is long, a method has been proposed in which through holes are filled with copper plating and stacked. By using this method, there are advantages such as simplification of the process, heat dissipation, and expansion of wiring space, and the necessity is increasing.

  On the other hand, conventionally used through-hole plating is still an indispensable technology. In this method, high reliability is required and it is important to secure the film thickness in the hole. In particular, it is desired that high throwing power can be obtained at a high current density in order to improve productivity.

  Conventionally, in the above-described via filling, through-hole filling, through-hole plating, etc., a method of performing plating treatment by direct current electrolysis mainly using a copper sulfate plating bath has been adopted.

  As a plating method using a copper sulfate plating bath, in addition to the direct current electrolysis method, a method of conducting electrolysis by applying a PR pulse current, a so-called PR pulse electrolysis method is known. This method is a method of repeatedly applying a current in a reverse direction for a short time after plating by energizing for a certain time, and is known as a plating method with good uniform electrodeposition. However, the PR pulse electrolysis method has a problem in that the appearance (glossiness) of the plating film is inferior to the direct current electrolysis method, and there is a problem that an extreme decrease is observed in film properties such as elongation and tensile strength. The PR pulse electrolysis method also has a problem that good filling properties cannot be obtained on a substrate having blind via holes.

  For these reasons, although the PR pulse electrolysis method has a feature of good throwing power, it has not been widely used as a plating method such as via filling, through-hole filling, and through-hole plating.

JP2003-328179A JP 2008-031516 JP 2008-266722 A

  The present invention has been made in view of the current state of the prior art described above, and its main purpose is to provide plating appearance, film physical properties, filling properties, etc. when electrolytic copper plating is conducted by applying a PR pulse current. An object of the present invention is to provide an additive for a copper plating solution used in a PR pulse electrolysis method that can be improved.

  The present inventor has intensively studied to achieve the above-described object. As a result, when performing electrolytic copper plating by the PR pulse electrolysis method, by adding at least one component selected from the group consisting of alkenes and alkynes to the electrolytic copper plating solution, the plating appearance and film properties The present inventors have found that it is possible to form an electrolytic copper plating film having excellent performance by improving the problem in the conventional PR pulse electrolysis method that the filling property and the like are lowered, and the present invention has been completed here.

That is, the present invention provides an additive for a copper plating solution used in the following PR pulse electrolysis method, a copper plating solution for plating by the PR pulse electrolysis method containing the additive, and a copper plating method by the PR pulse electrolysis method. Is.
1. An additive for a copper plating solution used in a PR pulse electrolysis method, comprising at least one component selected from the group consisting of alkenes and alkynes.
2. Alkenes are represented by the following general formula (I):

(Wherein R ^{1 to} R ⁴ are the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxyl group, a carboxyl group, a group: —SO ₃ M ¹ (wherein M ¹ is a hydrogen atom or an alkali metal) ), Group: —CONH ₂ , or group: —COOR (wherein R is a lower alkyl group which may have a hydroxyl group as a substituent), and the lower alkyl group includes a hydroxyl group, a carboxyl group, and a group: -SO ₃ M ¹ (wherein M ¹ may have at least one substituent selected from the group consisting of a hydrogen atom or an alkali metal).
Alkynes are represented by the following general formula (II):

(Wherein R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxyl group, a carboxyl group, an alkoxy group which may have a substituent, a group: —NR ⁷ ₂ (provided that R ⁷ is a hydrogen atom or an alkyl group), a group: —SO ₃ M ¹ (where M ¹ is a hydrogen atom or an alkali metal), or a group: — (O (CH ₂ ) _n ) _m —OH ( However, n is 2 or 3, m is an integer of 1-5, and this lower alkyl group is a carboxyl group, a hydroxyl group, an alkoxy group which may have a substituent, a group: —NR ⁷ ₂ (provided that , R ⁷ is a hydrogen atom or a lower alkyl group), a group: — (O (CH ₂ ) _n ) _m —OH (where n is 2 or 3, m is an integer of 1 to 5), and group: _-SO 3 ^{M 1} (where, ^{M 1} is a hydrogen atom or an alkali metal Additive for copper plating solution used in the PR pulse electrolysis method according to item 1 is a compound represented by at least a kind of substituent may be.) Selected from the group consisting of certain).
3. Alkenes and alkynes each comprise a hydroxyl group, a carboxyl group, a group: —SO ₃ M ¹ (where M ¹ is a hydrogen atom or an alkali metal), a group: —CONH ₂ , and an amino group. Item 3. An additive for copper plating solution used in the PR pulse electrolysis method according to Item 1 or 2, which has at least one hydrophilic group selected from the group.
4). An aqueous solution containing at least one acid component selected from copper ions and organic acids and inorganic acids as a basic plating bath,
Furthermore, the copper plating solution for plating by PR pulse electrolysis characterized by containing the additive in any one of said claim | item 1-3.
5). The basic plating bath is (i) at least one acid component selected from copper ions, (ii) organic acids and inorganic acids, (iii) chloride ions, and (iv) nonionic polyether polymer surfactants. And (v) a copper plating solution for plating by the PR pulse electrolysis method according to claim 4, which is an aqueous solution containing a sulfur-containing organic compound.
6). The basic plating bath is (i) at least one acid component selected from copper ions, (ii) organic acids and inorganic acids, (iii) chloride ions, and (iv) nonionic polyether polymer surfactants. The copper plating solution for plating by the PR pulse electrolysis method according to claim 4, wherein the aqueous solution contains (v) a sulfur-containing organic compound and (vi) a nitrogen-containing compound.
7). The copper plating solution for plating by the PR pulse electrolysis method according to any one of Items 4 to 6, wherein the additive according to any one of Items 1 to 3 is contained in an amount of 1 mg / L to 100 g / L.
8). 8. A copper plating method according to the PR pulse electrolysis method, wherein in the copper plating solution according to any one of the above items 4 to 7, electrolytic copper plating is performed by supplying a PR pulse current with the object to be plated as a cathode.

  The additive of the present invention is an additive for an electrolytic copper plating solution used in a method of conducting electroplating by applying a PR pulse current, that is, a so-called PR pulse electrolytic method, that is, an additive for a PR pulse electrolytic copper plating solution. The active ingredient is at least one selected from the group consisting of alkanes.

  By using an electrolytic copper plating solution to which such additives are added, the appearance of the formed plating is inferior to the direct current electrolytic method, which was a problem when performing electrolytic copper plating by the PR pulse electrolytic method. In addition, the PR pulse electrolytic copper plating method, via filling, through-hole filling, through-hole plating, etc. are greatly improved with various problems such as reduced physical properties of plating film, via filling, and through-hole filling. It can be effectively used as a plating method.

  Although there is no limitation in particular about alkenes used as an additive, in particular the following general formula (I):

(Wherein R ^{1 to} R ⁴ are the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxyl group, a carboxyl group, a group: —SO ₃ M ¹ (wherein M ¹ is a hydrogen atom or an alkali metal) ), A group: —CONH ₂ , or a group: —COOR (R is a lower alkyl group which may have a hydroxyl group as a substituent), and the alkyl group includes a hydroxyl group, a carboxyl group, and a group: —SO _3. A compound represented by M ¹ (wherein M ¹ may have at least one substituent selected from the group consisting of a hydrogen atom or an alkali metal) is preferable.

  The alkynes are not particularly limited, but in particular, the following general formula (II):

(Wherein R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxyl group, a carboxyl group, an alkoxy group which may have a substituent, a group: —NR ⁷ ₂ (provided that R ⁷ is a hydrogen atom or an alkyl group), a group: —SO ₃ M ¹ (where M ¹ is a hydrogen atom or an alkali metal), or a group: — (O (CH ₂ ) _n ) _m —OH ( However, n is 2 or 3, m is an integer of 1-5, and this lower alkyl group is a carboxyl group, a hydroxyl group, an alkoxy group which may have a substituent, a group: —NR ⁷ ₂ (provided that , R ⁷ is a hydrogen atom or a lower alkyl group), a group: — (O (CH ₂ ) _n ) _m —OH (where n is 2 or 3, m is an integer of 1 to 5), and group: _-SO 3 ^{M 1} (where, ^{M 1} is a hydrogen atom or an alkali metal May have at least one substituent selected from the group consisting of certain).) The compound represented by are preferred.

  In the above general formulas (I) and (II), the lower alkyl group is preferably a linear or branched alkyl group having about 1 to 5 carbon atoms, and specific examples thereof include methyl, ethyl, propyl , Isopropyl, butyl, isobutyl, tert-butyl, pentyl and the like.

Moreover, as an alkoxy group which may have a substituent in general formula (II), a C1-C5 alkoxy group is preferable. The alkoxy group may have one or two or more substituents selected from the group consisting of a hydroxyl group and —SO ₃ M ¹ (where M ¹ is a hydrogen atom or an alkali metal).

In the present invention, in particular, a hydroxyl group, a carboxyl group, a group: —SO ₃ M ¹ (where M ¹ is a hydrogen atom or an alkali metal) group: —CONH ₂ , an alkyne having at least one hydrophilic group such as an amino group And alkanes are preferred.

Specific examples of the alkene having a hydrophilic group include the following compounds (1) to (8). In the following chemical formulas, when there are geometrical isomers such as cis type and trans type, any isomers are effective.
(1) H ₂ C═CHCH ₂ OH
(2) H ₂ C═CHCH ₂ SO ₃ Na
_{(3) H 3 CHC = CH} -COOH
(4) HOOC-HC = CH-COOH
(5) H ₂ C═CHCONH _{2
(6) H 2 C = CHCH} 2 CH 2 OH
(7) H ₃ CHC═CHCH ₂ CH ₂ CH ₂ OH
(8) HOCCH ₂ CCOOH = CHCOOH
(9) H ₂ C═C (COOH) CH ₂ COOH
(10) H ₂ C═CHCH ₂ CH ₂ CH ₂ OH
Specific examples of alkynes having a hydrophilic group include the following compounds (11) to (21). In the following chemical formulas, when there are geometrical isomers such as cis type and trans type, any isomers are effective.
(11)

(12)

(13)

(14)

(15)

(16)

(17)

(18)

(19)

(20)

(21)

(22)

  The above alkynes and alkanes can be used singly or in combination of two or more.

  The concentration in the electrolytic copper plating solution of the additive comprising at least one component selected from the group consisting of the alkynes and alkanes is not particularly limited, but is usually about 1 mg / L to 100 g / L. Preferably, it is more preferably about 10 mg / L to 50 g / L.

  There is no particular limitation on the type of PR pulse electrolytic copper plating solution used as a basic bath using the additive of the present invention, and it contains at least one acid component selected from copper ions and organic acids and inorganic acids as an essential component. An acidic copper plating solution can be used.

  As the copper ion source, any copper compound that is soluble in the plating solution can be used without particular limitation. Specific examples of such a copper compound include copper sulfate, copper oxide, copper chloride, copper carbonate, copper pyrophosphate, alkane sulfonate copper, alkanol sulfonate copper, and organic acid copper. A copper compound can be used individually by 1 type or in mixture of 2 or more types.

  Although there is no limitation in particular about copper ion concentration, For example, it can be set as the range of about 10-250 g / L.

As the acid component, at least one selected from the group consisting of organic acids and inorganic acids can be used. Specific examples of organic acids include alkane sulfonic acids such as methane sulfonic acid, alkanol sulfonic acids, and the like, and specific examples of inorganic acids include sulfuric acid and the like. These acid components can be used singly or in combination of two or more. Although there is no limitation in particular about the density | concentration of an acid component, For example, it can be set as about 20-400 g / L.

  The PR pulse electrolytic copper plating solution contains chloride ions. The concentration is usually about 2 to 100 mg / L. In order to obtain such a concentration range, the chloride ion concentration in the plating solution may be adjusted using hydrochloric acid, sodium chloride, or the like, if necessary.

  Further, the PR pulse electrolytic copper plating solution usually contains a nonionic polyether polymer surfactant, a sulfur-containing organic compound, and the like as additives. Moreover, a nitrogen-containing organic compound etc. may be contained as needed. These additives may be appropriately selected from known additive components in the electrolytic copper plating solution. For example, the additive mix | blended with the copper sulfate plating solution for through-hole plating, the additive mix | blended with the copper sulfate plating for blind via holes, etc. can be used.

  Among such additives, nonionic polyether polymer surfactants are usually referred to as polymer components, such as polyethylene glycol, polypropylene glycol, polyethylene oxide, polyoxyalkylene glycol, etc. A polyether compound or the like can be used. The concentration of the nonionic polyether polymer surfactant is not particularly limited, but can be, for example, in the range of about 0.01 to 10 g / L.

  The sulfur-containing organic compound is usually called a brightener, and may be appropriately selected from known additive components. For example, sulfur compounds such as 3-mercaptopropanesulfonic acid, its sodium salt, bis (3-sulfopropyl) disulfide, its 2 sodium salt, N, N-dimethyldithiocarbamic acid (3-sulfopropyl) ester, its sodium salt, etc. Can be used. Although there is no limitation in particular about a sulfur-containing organic compound density | concentration, For example, it can be set as the range of about 0.1-200 mg / L.

  Further, the nitrogen-containing organic compound that can be added as needed is usually called a leveler, and this may be used by appropriately selecting from known additive components. For example, nitrogen compounds such as a phenazine compound, a safranine compound, a polyalkyleneimine, a thiourea derivative, and a polyacrylic acid amide can be used. Although there is no limitation in particular about a nitrogen-containing organic compound density | concentration, For example, it can be set as the range of about 0.1-200 mg / L.

The additive of the present invention can obtain a good effect particularly when the basic bath is a copper sulfate plating solution. Hereinafter, specific examples of the composition of the copper sulfate plating solution are shown.
* Copper sulfate plating solution Copper sulfate pentahydrate 20-300 g / L (preferably 50-250 g / L)
Sulfuric acid 20-300 g / L (preferably 50-250 g / L)
Chlorine ion 5-100 mg / L (preferably 30-80 mg / L)
The PR pulse electrolytic copper plating solution containing the additive of the present invention is an electrolytic copper plating solution used when performing electrolytic copper plating by applying a PR pulse current. The condition for energizing the PR pulse current when using the electrolytic copper plating solution is not particularly limited. Usually, the current density of positive electrolysis for depositing the copper plating film is about 0.1 to 10 A / dm ^2. preferably it may be the 1-5A / dm ² about, 0.1~100A / dm ² about the current density of the reverse electrolysis to dissolve the copper plating film, preferably, 1~80A / dm ² about And it is sufficient. The forward electrolysis time is preferably about 10 to 100 milliseconds, and the reverse electrolysis time is preferably about 0.1 to 10 milliseconds. In this case, the ratio of the normal electrolysis time and the reverse electrolysis time is preferably about normal electrolysis time: reverse electrolysis time = 1: 0.01 to 1: 0.1.

  About the liquid temperature of a plating solution, what is necessary is usually just about 10-40 degreeC.

  The method for stirring the plating solution is not particularly limited, and air stirring, jet stirring, and the like can be performed.

  When performing the plating treatment, both a soluble anode and an insoluble anode can be used as the anode. For example, as the soluble anode, for example, phosphorus-containing copper having a phosphorus content of about 0.02 to 0.06% can be used. As the insoluble anode, titanium coated with iridium oxide, titanium plated with platinum, or the like can be used. There is no particular limitation on the shape of the anode, and various shapes of anodes such as a rod shape, a spherical shape, and a plate shape can be used.

  In the PR pulse electrolytic copper plating solution containing the additive of the present invention, the type of the object to be plated is not particularly limited, but in particular, when a substrate having a minute hole such as a through hole or a via hole is to be plated, Due to the good throwing power, a plating film can be uniformly formed even inside the micropores. In addition, the appearance of the plating film to be formed has the same good appearance as when direct current electrolysis is performed, and the physical properties of the plating film such as elongation and tensile strength are also good.

  In the case of performing the plating treatment using the electrolytic copper plating solution containing the additive of the present invention, the pretreatment method is not particularly limited and may be followed by a conventional method. For example, when a printed wiring board in which through holes and via holes are formed is used as an object to be plated, the object subjected to electroless copper plating generally used for manufacturing a printed circuit board is degreased by a conventional method, After removing dirt and the like adhering in the previous step, pickling is performed to remove and activate the oxide film, and then immersion is performed in the plating solution of the present invention, and a PR pulse current is applied to perform electrolytic plating.

  Using the electrolytic copper plating solution containing the additive of the present invention, by performing copper plating by the PR pulse electrolytic method, while maintaining the excellent point of the PR electrolytic copper plating solution that the uniform electrodeposition is good The appearance, film physical properties, filling properties, etc. of the plating film to be formed can be improved.

  For this reason, the PR electrolytic copper plating solution containing the additive of the present invention can be used particularly effectively when performing via filling, through hole filling, through hole plating or the like by the electrolytic copper plating method.

Sectional drawing of the measurement part of the uniform electrodeposition property in Example 1. FIG. Sectional drawing of the measurement part of the via filling rate in Examples 10-12 and Comparative Examples 7-8. Sectional drawing of the measurement part of the through-hole filling rate in Examples 12-15 and Comparative Examples 9-10.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Examples 1-3 and Comparative Examples 1-2
Each additive shown in Table 1 was added to an electrolytic copper plating solution having the following basic composition to prepare a PR pulse electrolytic copper plating solution.

* Electrolytic copper plating solution composition Copper sulfate: 70 g / L
Sulfuric acid: 200g / L
Chlorine ion: 50mg / L
Additive: Top Lucina SF Base WR ^{* 1} 2.5ml / L
Top Lucina SF-B ^{* 2} 1.0ml / L
Top Lucina SF Leveler ^{* 3} 5.0ml / L

* 1: Product name, polymer surfactant-containing additive, manufactured by Okuno Pharmaceutical Industry Co., Ltd. * 2: Product name, sulfur-containing organic compound-containing additive, manufactured by Okuno Pharmaceutical Industry Co., Ltd. * 3: Product name, including Nitrogen organic compound-containing additive, manufactured by Okuno Pharmaceutical Co., Ltd.

A substrate having a large number of through-holes with a diameter of 0.3 mm and a depth of 1.6 mm and having an electroless copper plating film with a thickness of 1 μm formed on the entire surface is used as an object to be plated, and this is used as a degreasing solution (trade name: DP -320 Clean Okino Pharmaceutical Co., Ltd. (100 ml / L aqueous solution) was immersed at 45 ° C. for 5 minutes, washed with water for 1 minute, and immersed in 100 g / L dilute sulfuric acid for 1 minute for pretreatment. Subsequently, using each PR pulse electrolytic copper plating solution, electrolytic copper plating was performed by the PR pulse electrolytic method under the following plating conditions to form a copper plating film having a film thickness of 25 μm.

* Plating conditions Positive current density: 3A / dm ²
Reverse current density: 20A / dm ²
Positive electrolysis time: 10msec
Reverse electrolysis time: 0.3msec
Bath temperature: 23 ° C
Stirring: Air stirring

After conducting the electrolytic copper plating by applying a PR pulse current by the above method, the plating appearance and the throwing power were evaluated by the following methods. Moreover, about the electrolytic copper plating film | membrane formed on the stainless steel plate, the film | membrane physical property was evaluated with the following method. The results are shown in Table 1 below.

(1) Plating appearance:
The appearance of the formed plating film was visually evaluated. The case where the plating film has good gloss is represented by a circle, the case where it has a semi-gloss to gloss is represented by a triangle, and the case where it is not glossy is represented by a cross.

(2) Uniform electrodeposition After the completion of electrolytic plating, the plating thickness at the location shown in FIG. 1 was measured for the through-hole portion of the object to be plated. FIG. 1 is a cross-sectional view of a through hole. In FIG. 1, (1), (2), (3) and (4) are surface plating thicknesses, and (5) and (6) are plating thicknesses on the inner surface of the through hole. It is.

  Based on the measured value of the obtained film thickness, the throwing power was calculated by the following formula. A case where the throwing power is 80% or more is represented by a circle, and a case where the throwing power is less than 80% is represented by a cross.

(3) Physical Properties of Film Using a stainless steel plate as an object to be plated, electrolytic copper plating was conducted by applying a PR pulse current in the same manner as described above to form a copper plating film having a thickness of 50 μm. Next, after peeling the formed copper plating film from the stainless steel plate, elongation and tensile strength were measured using an autograph. A case where the elongation is 20% or more and a tensile strength is 300 N / mm ² or more is represented by a circle, and a case where either one is below the above range is represented by a cross.

  As is apparent from the above results, by performing PR pulse electrolysis using the electrolytic copper plating solutions of Examples 1 to 3 containing an alkene or alkyne as an additive, the electrodeposition is excellent in uniform electrodeposition and good appearance. And a copper plating film having film properties could be formed.

  On the other hand, when the plating solution of Comparative Example 1 containing neither alkenes nor alkynes is used and when the plating solution of Comparative Example 2 containing succinic acid, which is a saturated aliphatic carboxylic acid, is used, The formed plating film was inferior in appearance and film properties.

Examples 4-6 and Comparative Examples 3-4
Each additive shown in Table 2 was added to an electrolytic copper plating solution having the following basic composition to prepare a PR pulse electrolytic copper plating solution.

* Electrolytic copper plating solution composition Copper sulfate: 70 g / L
Sulfuric acid: 200g / L
Chlorine ion: 50mg / L
Additive: Top Lucina SF Base WR ^{* 1} 2.5ml / L
Top Lucina SF-B ^{* 2} 1.0ml / L
Top Lucina SF Leveler ^{* 3} 5.0ml / L

* 1: Product name, polymer surfactant-containing additive, manufactured by Okuno Pharmaceutical Co., Ltd. * 2: Product name, sulfur-containing organic compound-containing additive, manufactured by Okuno Pharmaceutical Industry Co., Ltd. * 3: Product name, including Nitrogen organic compound-containing additive, manufactured by Okuno Pharmaceutical Co., Ltd.

After performing the pretreatment by the same method as in Examples 1 to 3 using the same object to be plated in Examples 1 to 3, PR pulse electrolysis method was used under the following plating conditions using each PR pulse electrolytic copper plating solution. Then, electrolytic copper plating was performed to form a copper plating film with a film thickness of 25 μm.

* Plating conditions Positive current density: 3A / dm ²
Reverse current density: 10A / dm ²
Positive electrolysis time: 10msec
Reverse electrolysis time: 0.5msec
Bath temperature: 23 ° C
Agitation: Air agitation After performing electrolytic copper plating by applying a PR pulse current by the method described above, the plating appearance, film physical properties and uniform electrodeposition were evaluated in the same manner as in Examples 1-3. The results are shown in Table 2 below.

  As is clear from the above results, by performing PR pulse electrolysis using the electrolytic copper plating solutions of Examples 4 to 6 containing alkenes or alkynes as additives, the electrodeposition is excellent in uniform electrodeposition and good appearance. And a copper plating film having film properties could be formed.

  On the other hand, it is formed when the plating solution of Comparative Example 3 containing neither alkenes nor alkynes is used, and when the plating solution of Comparative Example 4 containing butanediol, which is a saturated alcohol, is used. The plated film was inferior in appearance and film properties.

Examples 7-9 and Comparative Examples 5-6
Each additive shown in Table 3 was added to an electrolytic copper plating solution having the following basic composition to prepare a PR pulse electrolytic copper plating solution.

* Electrolytic copper plating solution composition Copper sulfate: 70 g / L
Sulfuric acid: 200g / L
Chlorine ion: 50mg / L
Additive: Top Lucina PR-A ^{* 4} 10ml / L
Top Lucina PR-B ^{* 5} 1.0ml / L

* 4: Product name, polymer surfactant-containing additive, manufactured by Okuno Pharmaceutical Industries, Ltd. * 5: Product name, sulfur-containing organic compound-containing additive, manufactured by Okuno Pharmaceutical Industries, Ltd.

After performing the pretreatment by the same method as in Examples 1 to 3 using the same object to be plated in Examples 1 to 3, PR pulse electrolysis method was used under the following plating conditions using each PR pulse electrolytic copper plating solution. Then, electrolytic copper plating was performed to form a copper plating film with a film thickness of 25 μm.

* Plating conditions Positive current density: 3A / dm ²
Reverse current density: 7.5A / dm ²
Positive electrolysis time: 10msec
Reverse electrolysis time: 0.3msec
Bath temperature: 23 ° C
Stirring: Air stirring

After conducting the electrolytic copper plating by supplying a PR pulse current by the above-described method, the plating appearance, film physical properties and uniform electrodeposition were evaluated in the same manner as in Examples 1 to 3. The results are shown in Table 3 below.

  As is apparent from the above results, by performing PR pulse electrolysis using the electrolytic copper plating solutions of Examples 7 to 9 containing alkenes or alkynes as additives, the electrodeposition is excellent in uniform electrodeposition and good appearance. And a copper plating film having film properties could be formed.

  On the other hand, it is formed when the plating solution of Comparative Example 5 containing neither alkenes nor alkynes is used, and when the plating solution of Comparative Example 6 containing butanediol, which is a saturated alcohol, is used. The plated film was inferior in appearance.

Examples 10-12 and Comparative Examples 7-8
Each additive shown in Table 4 was added to an electrolytic copper plating solution having the following basic composition to prepare a PR pulse electrolytic copper plating solution.

* Electrolytic copper plating solution composition
Copper sulfate: 200 g / L
Sulfuric acid: 50 g / L
Chlorine ion: 50mg / L
Additive: Top Lucina α-M ^{* 6} 4.5ml / L
Top Lucina α-2 ^{* 7} 1.0ml / L
Top Lucina α-3 ^{* 8} 3.0ml / L

* 6: Product name, polymer surfactant-containing additive, manufactured by Okuno Pharmaceutical Co., Ltd. * 7: Product name, sulfur-containing organic compound-containing additive, manufactured by Okuno Pharmaceutical Industry Co., Ltd. * 8: Product name, including Nitrogen organic compound-containing additive, manufactured by Okuno Pharmaceutical Co., Ltd.

A substrate that has a large number of vias with a diameter of 100 μm and a depth of 60 μm and an electroless copper plating film with a thickness of 1 μm formed on the entire surface is used as the object to be plated. A 100 ml / L aqueous solution manufactured by Kogyo Co., Ltd.) was immersed at 45 ° C. for 5 minutes, washed with water for 1 minute, and then immersed in 100 g / L dilute sulfuric acid for 1 minute for pretreatment. Subsequently, using each PR pulse electrolytic copper plating solution, electrolytic copper plating was performed by the PR pulse electrolytic method under the following plating conditions to form a copper plating film having a film thickness of 25 μm.

* Plating conditions Positive current density: 1A / dm ²
Reverse current density: 10A / dm ²
Positive electrolysis time: 10msec
Reverse electrolysis time: 0.2msec
Bath temperature: 23 ° C
Stirring: Air stirring After conducting electrolytic copper plating by applying a PR pulse current by the method described above, the plating appearance and film properties were evaluated in the same manner as in Examples 1 to 3, and via filling was further performed by the following method. Sex was evaluated. The results are shown in Table 4 below.

(1) Via filling property After the completion of electrolytic plating, a cross-sectional observation of the via portion of the object to be plated was performed, and the embedding property of the via portion was evaluated. As an evaluation method, as shown in FIG. 2, the via filling rate was obtained by the following formula, with the thickness from the via bottom to the plating surface being the total thickness, and the plating thickness of the via portion being the filling amount.
A case where the via filling rate is 80% or more is represented by a circle, and a case where the via filling rate is less than 80% is represented by a cross.

    Via filling rate (%) = (embedding amount / total thickness) × 100

  As is clear from the above results, by performing PR pulse electrolysis using the electrolytic copper plating solution of Examples 10-12 containing an alkene or alkyne as an additive, it has a good appearance and film properties, A copper plating film with excellent via filling properties could be formed.

  In contrast, when the plating solution of Comparative Example 7 containing neither alkenes nor alkynes is used, and when the plating solution of Comparative Example 8 containing succinic acid, which is a saturated aliphatic carboxylic acid, is used. The formed plating film was inferior in appearance, film properties and via filling properties.

Examples 13-15 and Comparative Examples 9-10
Each additive shown in Table 5 was added to an electrolytic copper plating solution having the following basic composition to prepare a PR pulse electrolytic copper plating solution.

* Electrolytic copper plating solution composition Copper sulfate: 200 g / L
Sulfuric acid: 50 g / L
Chlorine ion: 50mg / L
Additive: Top Lucina α-M ^{* 6} 4.5ml / L
Top Lucina α-2 ^{* 7} 1.0ml / L
Top Lucina α-3 ^{* 8} 3.0ml / L

* 6: Product name, polymer surfactant-containing additive, manufactured by Okuno Pharmaceutical Co., Ltd. * 7: Product name, sulfur-containing organic compound-containing additive, manufactured by Okuno Pharmaceutical Industry Co., Ltd. * 8: Product name, including Nitrogen organic compound-containing additive, manufactured by Okuno Pharmaceutical Co., Ltd.

A substrate with a number of through-holes with a diameter of 0.1 mm and a depth of 0.2 mm and an electroless copper plating film with a thickness of 1 μm formed on the entire surface is used as the object to be plated, and this is used as a degreasing solution (trade name: DP- 320 Clean (Okuno Pharmaceutical Co., Ltd., 100 ml / L aqueous solution) was immersed at 45 ° C. for 5 minutes, washed with water for 1 minute, and immersed in 100 g / L dilute sulfuric acid for 1 minute for pretreatment. Subsequently, using each PR pulse electrolytic copper plating solution, electrolytic copper plating was performed by the PR pulse electrolytic method under the following plating conditions to form a copper plating film having a film thickness of 30 μm.

* Plating conditions Positive current density: 1.5A / dm ²
Reverse current density: 20A / dm ²
Positive electrolysis time: 10msec
Reverse electrolysis time: 0.2msec
Bath temperature: 23 ° C
Stirring: Air stirring After conducting the electrolytic copper plating by applying the PR pulse current by the method described above, the plating appearance and film properties were evaluated in the same manner as in Examples 1-3, and further, through-hole filling was performed by the following method. Sex was evaluated. The results are shown in Table 5 below.

(1) Through-hole filling property After electrolytic plating was completed, the cross-sectional observation of the through-hole portion of the object to be plated was performed to evaluate the embedding property of the through-hole portion. As an evaluation method, as shown in FIG. 3, the thickness from the plating surface to the plating back surface was defined as the total thickness, and the plating thickness at the through hole portion was used as the burying amount. A case where the through-hole filling rate is 80% or more is represented by a circle, and a case where the through-hole filling ratio is less than 80% is represented by a cross.

    Through-hole filling rate (%) = (embedding amount / total thickness) × 100

  As is clear from the above results, by performing PR pulse electrolysis using the electrolytic copper plating solutions of Examples 13 to 15 containing an alkene or alkyne as an additive, it has a good appearance and film properties, A copper plating film with excellent through-hole filling properties could be formed.

  On the other hand, it is formed when the plating solution of Comparative Example 9 containing neither alkenes nor alkynes is used, and when the plating solution of Comparative Example 10 containing butanediol, which is a saturated alcohol, is used. The plated film was inferior in appearance, film properties and through-hole filling properties.

Claims (8)

An additive for a copper plating solution used in a PR pulse electrolysis method, comprising at least one component selected from the group consisting of alkenes and alkynes. Alkenes are represented by the following general formula (I):

(Wherein R ^{1 to} R ⁴ are the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxyl group, a carboxyl group, a group: —SO ₃ M ¹ (wherein M ¹ is a hydrogen atom or an alkali metal) ), Group: —CONH ₂ , or group: —COOR (wherein R is a lower alkyl group which may have a hydroxyl group as a substituent), and the lower alkyl group includes a hydroxyl group, a carboxyl group, and a group: -SO ₃ M ¹ (wherein M ¹ may have at least one substituent selected from the group consisting of a hydrogen atom or an alkali metal).
Alkynes are represented by the following general formula (II):

(Wherein R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxyl group, a carboxyl group, an alkoxy group which may have a substituent, or a group: —NR ⁷ ₂ (provided that R ⁷ is a hydrogen atom or an alkyl group), a group: —SO ₃ M ¹ (where M ¹ is a hydrogen atom or an alkali metal), or a group: — (O (CH ₂ ) _n ) _m —OH ( However, n is 2 or 3, m is an integer of 1-5, and this lower alkyl group is a carboxyl group, a hydroxyl group, an alkoxy group which may have a substituent, a group: —NR ⁷ ₂ (provided that , R ⁷ is a hydrogen atom or a lower alkyl group), a group: — (O (CH ₂ ) _n ) _m —OH (where n is 2 or 3, m is an integer of 1 to 5), and group: _-SO 3 ^{M 1} (where, ^{M 1} is a hydrogen atom or an alkali metal Additive for copper plating solution used in the PR pulse electrolysis method according to claim 1 which is a compound represented by selected from the group consisting of certain) at least one may have a substituent.). Alkenes and alkynes each comprise a hydroxyl group, a carboxyl group, a group: —SO ₃ M ¹ (where M ¹ is a hydrogen atom or an alkali metal), a group: —CONH ₂ , and an amino group. The additive for copper plating solutions used for PR pulse electrolysis method of Claim 1 or 2 which has at least 1 type of hydrophilic group chosen from the group. An aqueous solution containing at least one acid component selected from copper ions and organic acids and inorganic acids as a basic plating bath,
Furthermore, the copper plating solution for plating by PR pulse electrolysis characterized by containing the additive in any one of Claims 1-3. The basic plating bath is (i) at least one acid component selected from copper ions, (ii) organic acids and inorganic acids, (iii) chloride ions, and (iv) nonionic polyether polymer surfactants. And (v) a copper plating solution for plating by the PR pulse electrolysis method according to claim 4, which is an aqueous solution containing a sulfur-containing organic compound. The basic plating bath is (i) at least one acid component selected from copper ions, (ii) organic acids and inorganic acids, (iii) chloride ions, and (iv) nonionic polyether polymer surfactants. The copper plating solution for plating by the PR pulse electrolysis method according to claim 4, wherein the aqueous solution contains (v) a sulfur-containing organic compound and (vi) a nitrogen-containing compound. The copper plating solution for plating by the PR pulse electrolysis method according to any one of claims 4 to 6, comprising 1 mg / L to 100 g / L of the additive according to any one of claims 1 to 3. A copper plating method by a PR pulse electrolysis method, characterized in that in the copper plating solution according to any one of claims 4 to 7, an electrolytic copper plating is performed by applying a PR pulse current with the object to be plated as a cathode.

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