CN111235555A

CN111235555A - Two-layer flexible copper-clad laminate substrate and method for producing same

Info

Publication number: CN111235555A
Application number: CN201911409524.5A
Authority: CN
Inventors: 大野晃宜; 高德诚; 滨田实香
Original assignee: JCU Corp
Current assignee: JCU Corp
Priority date: 2008-12-08
Filing date: 2009-12-04
Publication date: 2020-06-05
Anticipated expiration: 2029-12-04
Also published as: TW201035373A; JP2010159478A; KR20110099101A; CN102245805A; WO2010067854A1; TWI494470B; CN111235555B; KR101634835B1; CN106011803A; JP5385625B2

Abstract

The present invention relates to a two-layer flexible copper-clad laminate substrate and a method for producing the same. The present invention provides a method for manufacturing a two-layer flexible copper-clad laminate substrate, which is a method for manufacturing a two-layer FCCL by a wet plating method using an acidic copper plating bath composition and a resin film coated with a conductive metal as a seed layer, the method including: forming an electroless nickel plating seed layer on the surface of the resin film subjected to the hydrophilization surface modification; and a step of performing wet plating to form a copper-plated conductive layer on the seed layer without performing copper plating 1 time in the acidic copper plating bath composition.

Description

Two-layer flexible copper-clad laminate substrate and method for producing same

The application is as follows

(international application date is 2009, 12/4), and a divisional application of PCT application entitled "two-layer flexible copper-clad laminate substrate and method for producing same" which is at the state of entry.

Technical Field

The present invention relates to a two-layer flexible copper-clad laminate substrate and a method for producing the same, and more particularly, to a two-layer flexible copper-clad laminate substrate (two-layer FCCL) that is smooth, has a glossy appearance, is excellent in peeling resistance, and is easily subjected to fine patterning by thick plating of copper on the surface of a resin film using an acidic copper plating bath composition.

The present invention also relates to a method for producing a two-layer flexible copper-clad laminate substrate of such a two-layer FCCL by a wet plating method in which an acid copper plating bath composition is used and the plating step is a 1-step.

Background

In recent years, electronic devices such as mobile phones, computers, video recorders, and game machines have been in fact: the density and size of components used have been increased, and printed boards and the like on which these components are mounted are also required to have further increased densities of circuits mounted thereon, and through holes and blind vias used for interlayer connection of at least one surface of the board or a multilayer board tend to have smaller diameters and higher aspect ratios.

In addition, conventionally, in these mounted circuits, connection between the circuit layers is performed by conductive metal deposited in minute holes such as blind holes and through holes provided in the laminated board, and in general, the connection between the circuit layers is performed by a blind hole plating method in which a conductive metal coating is formed on the inner surface and the bottom surface of the blind hole.

On the other hand, in general, the through-hole is generally connected between the layers of the substrate by a through-hole plating method in which a uniform conductive metal coating is formed on the inner surface of the through-hole.

For such a substrate, a polyimide resin film is widely used as an insulating substrate material for electronic components such as a Printed Wiring Board (PWB), a flexible printed wiring board (FPC), a tape for Tape Automated Bonding (TAB) tape, a Chip On Film (COF) tape, and the like. Such PWB, FPC, TAB tape, and COF tape use a metal-coated polyimide film substrate in which copper is mainly coated on at least one surface of a polyimide resin film as a metal conductor layer.

In the processing (or production) of such a metal-coated polyimide film substrate, conventionally, for example, there are the following substrates: 1) a 3-layer copper polyimide substrate obtained by bonding a polyimide film and a copper foil via an adhesive; 2) a copper layer is directly formed on a polyimide film to obtain a two-layer copper polyimide substrate. In addition, the latter two-layer Copper polyimide substrate [ ("two-layer Flexible Copper Clad Laminate"; "two-layer FCCL) ] is prepared by the following method: a tape casting method of forming a polyimide film on a copper foil; a lamination method of thermocompression bonding a copper foil and a polyimide film with a thermoplastic polyimide; a sputtering/plating method (a metal spraying method) in which a conductive layer is formed by electroplating after a seed layer is formed by sputtering has various advantages and disadvantages from the viewpoints of adhesion to copper, dimensional stability, fine patterning, and the like. Among them, particularly advantageous for fine patterning can be said to be a two-layer FCCL based on a sputtering/plating method (metallization method).

For example, patent document 1 describes a two-layer plating base material (or substrate) in which matte copper plating is applied to a polyimide film subjected to conductive treatment in a range of 0.5 to 2 μm and then glossy copper plating is applied so that the thickness of a copper plating layer becomes 20 μm or less in order to cope with a technical tendency of further miniaturization and thinning of a TAB tape or COF tape, which is smaller than conventional ones, with the miniaturization and thinning of portable electronic devices, that is, higher density and narrower wiring pitch.

As described above, the two-layer plating base material in which the thickness of the copper layer can be reduced and the thickness thereof can be controlled as desired can be said to be a base material suitable for forming a fine pattern because of its flexibility and a flat bonding interface between the polyimide film and the copper layer having a thickness of 10 μm or less. However, in recent years, since finer patterning is required, in the production of electronic components such as PWB, FPC, TAB tape, COF tape, etc., using such a two-layer plating substrate, the surface of the two-layer plating substrate is required to be smoother, particularly because exposure unevenness and etching unevenness are caused.

Further, the sputtering/plating method (metallization method) which is advantageous for fine patterning as described above generally has a problem that (1) the apparatus scale is large because the plasma treatment is performed on the surface of the polyimide resin film as the pretreatment, the metallization treatment is performed by sputtering under vacuum, and the like. Further, (2) since a dry treatment such as a plasma treatment or a sputtering treatment is followed by a wet treatment by plating, the manufacturing process tends to be difficult to continue, the productivity tends to be low, and the cost tends to be high. Further, (3) there is a tendency that swelling after copper electroplating or swelling is liable to occur by heat treatment (also referred to as baking treatment), and adhesion between "polyimide-electroless nickel plating" and "electroless nickel-electrolytic copper plating" is partially reduced.

In order to solve these problems, patent document 2 proposes a method for metallizing a surface of a polyimide resin material, which does not require any special plasma treatment or sputtering treatment, is a main process of a wet treatment, is easy to perform a continuous treatment, does not cause deterioration or migration of insulation resistance, has good plating deposition stability, and ensures smoothness and adhesion between a polyimide resin film and a metal regardless of the type of the polyimide resin.

That is, the surface metallization method is a method for surface metallization of a polyimide resin material, which includes a surface treatment step of a polyimide resin material using an aprotic polar solvent having a carbonyl group (particularly dimethylformamide or the like) in the molecule, a surface oxidation treatment step of using an aprotic polar solvent having a carbonyl group (particularly dimethylformamide or the like) in the molecule, and a treatment step using an alkaline aqueous solution as a pretreatment of the polyimide resin material, and a thick copper plating treatment after an electroless nickel plating treatment is an alkaline electroless copper plating treatment or an alkaline copper plating treatment to obtain a double-layer FCCL.

Patent document 3 describes the following technique: at least one surface of a polyimide film, which is often used as PWB, FPC, TAB, or COF, is surface-modified with oxygen plasma, then a seed layer of a conductive metal is formed by sputtering Ni, Cr, a Ni — Cr alloy, or the like, then a copper layer is sputtered to form 1 copper plating, and then thick copper plating is performed by a copper plating method or an electroless copper plating method to form a double-layer FCCL that exhibits heat-resistant adhesion equal to or higher than that of a 3-layer substrate (400N/m or higher), and the main reason for this is that the surface of the polyimide resin is given appropriate roughness and chemical modification by pretreatment with the oxygen plasma.

Patent document 1: japanese patent laid-open publication No. 2007-23344

Patent document 2: japanese patent laid-open publication No. 2007-262481

Patent document 3: japanese patent laid-open No. 2008-78276.

Disclosure of Invention

Under such circumstances, the present inventors have focused on the technical fields including patent documents 1 to 3, and have conducted extensive studies on the surface of various substrates used in the fields, and have proposed a novel leveling agent for plating which exhibits excellent plating appearance such as plating spreading ability in the interior or corner of a blind via or a through hole and leveling property of a plated surface, and which can cope with a defective substrate. Based on these results, copper plating is performed with high reliability on a substrate having micro holes such as through holes and blind vias or a resin film coated with a conductive metal such as copper by using an acidic copper plating bath composition containing the leveling agent as a component, and a patent has been filed as a copper plating method for such a substrate (japanese patent application laid-open No. 2006-243651) (see japanese unexamined patent application laid-open No. 2008-63624).

That is, a resin film having a substrate having micro holes such as through holes and blind holes or a surface coated with a conductive metal such as copper can be subjected to copper plating treatment with higher reliability than conventional products by using an acidic copper plating bath.

The object of the invention is therefore: in recent years, as for various electronic devices, the density and size reduction of components used therein have been advanced, and further densification, further reduction in diameter, and increase in aspect ratio have been demanded for mounting circuits provided on printed boards and the like on which these are mounted, and in the case of having such a tendency, there has been provided a metal-coated resin film substrate which is a two-layer flexible copper-clad laminate substrate (two-layer FCCL) obtained by wet-coating a resin film such as a polyimide film with a thick thickness without 1-time copper plating using a newly developed acidic copper plating bath composition, and which has a smooth and glossy appearance of a plating layer, and which has excellent peeling resistance of a copper plating layer and is easy to be finely patterned.

Further, another object of the present invention is to: the method for producing a metal-coated resin film substrate of the double-layer FCCL is a method in which the entire process is a wet process using the newly developed acidic copper plating bath composition and the copper plating process is performed by thick plating in 1 step.

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that: in an acidic copper plating bath composition containing 1 component of a copolymer of "diallyldialkyl ammonium alkyl sulfate" - "(meth) acrylamide" - "sulfur dioxide" as a leveling agent for plating, when copper is thickly plated on a resin film on which a conductive Ni metal coating seed layer is formed in advance without 1-time copper plating, a two-layer flexible copper-clad laminate (two-layer FCCL) exhibits a smooth glossy appearance, and the peeling resistance of the resulting copper plated layer is particularly improved, thereby completing the present invention.

That is, the present invention provides a two-layer flexible copper-clad laminate substrate, characterized in that a seed layer having a coating thickness of Ni or an alloy thereof in the range of 10 to 300nm is formed in advance by electroless plating on the surface of a resin film substrate subjected to hydrophilization modification as a pretreatment,

on the seed layer, thick plating is performed with a copper plating coating thickness in the range of 0.05 to 50 μm using an acidic copper plating bath composition without passing through 1-time copper plating as strike copper plating.

Further, according to the present invention, the seed layer-coated resin film substrate coated with Ni or an alloy thereof having a thickness in the range of 10 to 300nm and the newly developed acidic copper plating bath composition used for the substrate can provide a smooth copper plating layer of a two-layer flexible copper-clad laminate base material (two-layer FCCL) having a glossy appearance and a peeling resistance,

(1) a resin film substrate used for the two-layer flexible copper-clad laminate base material is a polyimide film having a conductive metallic nickel seed layer as a seed layer subjected to electroless plating.

(2) The acidic copper plating bath composition comprises (A) a copper ion component, (B) an organic acid and/or an inorganic acid component, (C) a chloride ion component, (D) an organic polymer component, (E) a brightener component, and (F) a copolymer component of diallyl dialkyl ammonium alkyl sulfate, a (meth) acrylamide compound, and sulfur dioxide as a leveling agent for plating.

The present invention also provides a method for producing a two-layer flexible copper-clad laminate substrate (two-layer FCCL), which is characterized in that a newly developed acidic copper plating bath composition is used, and the entire steps including the steps of forming a seed layer and thick-plating a copper conductive layer on the seed layer are wet processes, and the entire copper plating step is a single step, thereby producing a two-layer flexible copper-clad laminate substrate (two-layer FCCL) that exhibits the above-described effects.

That is, the method for producing a two-layer flexible copper-clad laminate substrate includes:

a step of forming a conductive metal seed layer of Ni or an alloy thereof in advance by electroless plating on the surface of the resin film substrate subjected to hydrophilization surface modification;

and a step of subjecting the acid copper plating bath composition to wet plating in a single step without performing 1-time copper plating as strike copper plating, thereby thickly plating a copper conductive layer on the seed layer.

In addition, in the method for producing the two-layer flexible copper-clad laminate substrate of the present invention,

(1): a method for manufacturing a two-layer flexible copper-clad laminate substrate in which the conductive metal as the seed layer is any one of Ni and an alloy thereof can be provided.

(2): the resin film substrate used in the method is a polyimide film obtained by electroless nickel plating.

(3): the acidic copper plating bath composition used in the method for producing a two-layer flexible copper-clad laminate base material is composed of (A) a copper ion component, (B) an organic acid and/or an inorganic acid component, (C) a chloride ion component, (D) an organic polymer component, (E) a brightener component, and (F) a copolymer component of ammonium diallyldialkyl alkyl sulfate and (meth) acrylamides and sulfur dioxide as a leveling agent for plating.

(4) Further, there can be provided a method for producing a two-layer flexible copper-clad laminate base material, wherein the (D) organic polymer component is at least 1 species selected from the group consisting of polyethylene glycol, polypropylene glycol, pluronic (プロルニック) type surfactant, ferrotecan (テトロニック) type surfactant, polyethylene glycol seeded glycerin ether, polyethylene glycol seeded dialkyl ether.

(5) Further, there can be provided a method for producing a two-layer flexible copper-clad laminate substrate, wherein the (E) brightener component is at least 1 selected from the group consisting of a sulfoalkylsulfonate, an organic disulfide compound, and a dithiocarbamate derivative.

Effects of the invention

The present invention can provide a double-layer flexible copper-clad laminate substrate in which 2 times of copper plating for forming a thick plating is performed on a seed layer of a conductive metal-coated resin film without performing 1 time of copper plating as strike copper plating, and which has smooth thick-plated copper layer, glossy appearance, excellent peeling resistance, and easy fine patterning, utilizing the characteristics of an acidic copper plating bath composition used.

Further, the present invention can provide a method for producing a two-layer FCCL, which can produce such a two-layer flexible copper-clad laminate substrate (two-layer FCCL) that is smooth, glossy in appearance, exhibits excellent peeling resistance, and has a copper-coated surface that can be easily finely patterned, with a simple apparatus, low running cost, remarkably high reliability, and high productivity, by utilizing the characteristics of the acidic copper plating bath composition used, and the like, and by using a wet process and a 1-step copper plating process as all the processes such as formation of a seed layer and thick plating of the copper conductive layer.

Detailed Description

Hereinafter, embodiments of the two-layer flexible copper-clad laminate substrate and the method for producing the same according to the present invention will be described in more detail.

< acidic copper plating bath composition used in the present invention >

As described above, the acidic copper plating bath composition used in the present invention is characterized by comprising (a) a copper ion component, (B) an organic acid and/or an inorganic acid component, (C) a chloride ion component, (D) an organic polymer component, (E) a brightener component, and (F) a copolymer component of ammonium diallyldialkyl sulfate, a (meth) acrylamide compound, and sulfur dioxide as a leveling agent for plating.

The copper ion component (a) is not particularly limited as long as it is a copper compound that is generally dissolved in an acidic solution. In the present invention, for example, copper sulfate (preferably pentahydrate), copper alkanesulfonate such as copper oxide, copper chloride, copper carbonate, copper pyrophosphate, copper methanesulfonate, and copper propanesulfonate, copper alkylbenzenesulfonate such as copper propoxysulfonate, and organic acid copper such as copper acetate, copper citrate, and copper tartrate, and salts thereof can be mentioned. These copper compounds may be used alone or in combination of two or more thereof.

The concentration of copper ions in the copper ion component (A) is preferably 10 to 75g/L, more preferably 15 to 65g/L, in the acidic copper plating bath composition. Particularly, when the acidic copper plating bath composition is used for plating a through hole and a resin film, the concentration is preferably 15 to 30g/L in terms of copper ions, and when the acidic copper plating bath composition is used for plating a blind via, the concentration is preferably 25 to 65g/L in terms of copper ions. When copper sulfate pentahydrate is used as the copper ion source, the concentration of the copper sulfate pentahydrate in the acidic copper plating bath composition is preferably 40 to 300 g/L. In addition, when the metal sputtering film is used for a through hole and a metal sputtering film, the concentration is preferably 60-120 g/L, and when the metal sputtering film is used for a blind hole, the concentration is preferably 100-250 g/L.

The organic acid and/or inorganic acid component (B) may be suitably used without any particular limitation as long as it is a substance that can dissolve copper. In the present invention, preferable specific examples of the organic acid or inorganic acid include sulfuric acid as an inorganic acid, alkane sulfonic acids such as methane sulfonic acid and propane sulfonic acid as an organic acid, alkanol sulfonic acids such as propanol sulfonic acid, and organic acids such as citric acid, tartaric acid, and formic acid. These organic acids or inorganic acids may be used alone or in combination of two or more thereof.

The concentration of the organic acid and/or inorganic acid component (B) in the acidic copper plating bath composition is preferably 30 to 300g/L, more preferably 50 to 250 g/L. Particularly, it is preferably 150 to 250g/L when used for plating a through hole and a resin film, and preferably 50 to 150g/L when used for plating a blind hole. When the acid component is sulfuric acid, the concentration of the acid component in the acidic copper plating bath composition is preferably 30 to 300 g/L. In addition, the through hole and metal sputtering film is preferably 150-250 g/L, and the blind hole is preferably 50-150 g/L.

In addition, the concentration of the (C) chloride ion component in the acidic copper plating bath composition used in the present invention is preferably 20 to 100mg/L, and particularly preferably 30 to 70mg/L, in terms of chloride ion.

In addition, the organic polymer component (D) functions as a wetting agent for improving wettability of the plating solution, and in the present invention, for example, polyethylene glycol, polypropylene glycol, pluronic type surfactant, ferrotall type surfactant, polyethylene glycol, and the like can be appropriately listed. Here, polyethylene glycol having a degree of polymerization of ethylene oxide within a range of 10 to 500 is suitably used as polyethylene glycol, and polypropylene glycol having a degree of polymerization of propylene oxide within a range of 1 to 20 is suitably used as polypropylene glycol.

Further, examples of the Pluronic type surfactant include a compound represented by the general formula (I),

[ solution 1]

HO-（C₂H₄O）_a-（C₃H₆O）_b-（C₂H₄O）_c-H （Ⅰ）

[ wherein a and c each represent a number of 1 to 30, and b represents a number of 1 to 100 ];

examples of the ferroptonik type surfactant include compounds represented by the general formula (VII),

[ solution 2]

[ in the formula, d represents a numerical value of 1 to 200, and e represents a numerical value of 1 to 40 ].

Furthermore, as the polyethylene glycol, a seed or a glycerin ether, for example, a compound represented by the general formula (VIII),

[ solution 3]

[ wherein f, g and h each represent a number of 1 to 200 ];

examples of the polyethylene glycol(s) may include those represented by the general formula (IX),

[ solution 4]

R⁷O-（C₂H₄）_i-OR⁸（IX）

[ in the formula, R⁷And R⁸Each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, i represents 2 to c200, etc. ].

In the present invention, as the organic polymer component (D), any 1 kind of the polymer components may be suitably used, or any two or more kinds of the polymer components may be suitably used in combination, and the concentration of the organic polymer component (D) is preferably 100 to 20000mg/L, and particularly preferably 1000 to 10000mg/L in the acidic copper plating bath composition.

Further, the brightener (E) has an effect of uniformizing the crystal orientation of the plating layer. Examples of the compound of the present invention include mercaptoalkylsulfonates, organic disulfide compounds, and dithiocarbamic acid derivatives.

Examples of the mercaptoalkylsulfonic acid salt include compounds represented by the general formula (X),

[ solution 5]

HS-L¹-SO₃M （X）

[ in the formula, L¹Represents a saturated or unsaturated alkylene group having 1 to 18 carbon atoms, and M represents an alkali metal ].

Further, as the organic disulfide compound, for example, a compound represented by the general formula (XI),

[ solution 6]

X¹-L²SSL³-X²（XI）

[ in the formula, L²And L³Each independently represents a saturated or unsaturated alkylene group having 1 to 18 carbon atoms, X¹And X²Each independently represents a sulfate group or a phosphate group ].

Examples of the dithiocarbamic acid derivative include compounds represented by the general formula (XII),

[ solution 7]

[ in the formula, R⁹And R¹⁰Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, L⁴Alkylene having 3 to 6 carbon atomsBase, X³Represents a sulfate group or a phosphate group ].

In the present invention, these (E) brightener components may be used alone in any 1 kind, or may be used in combination of any two or more kinds as appropriate. The concentration of the brightener (E) is preferably 0.02 to 200mg/L, more preferably 0.2 to 5.0mg/L, in the acidic copper plating bath composition.

The leveling agent for plating (F) is a copolymer of ammonium diallyldialkyl alkyl sulfate having a structural unit represented by general formula (XIII), a (meth) acrylamide compound having a structural unit represented by general formula (XIV), and sulfur dioxide having a structural unit represented by general formula (XV).

[ solution 8]

[ in the formula, R¹、R²Each independently being methyl, ethyl or hydroxyethyl, R¹、R²Not simultaneously being hydroxy, R³Is a methyl or ethyl group ],

[ solution 9]

[ in the formula, R⁴Is a hydrogen atom or a methyl group, R⁵、R⁶Independently represents a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, or a cycloalkyl group having 2 to 7 carbon atoms which may have an ether bond in the ring,

[ solution 10]

Examples of the diallyldialkyl ammonium alkyl sulfate in the present invention include diallyldimethyl ammonium methyl sulfate, diallylethyl ammonium methyl sulfate, diallyldiethyl ammonium methyl sulfate, diallylethyl (hydroxyethyl) ammonium methyl sulfate, diallyldimethyl ammonium ethyl sulfate, diallylethyl ammonium methyl sulfate, diallyldiethyl ammonium ethyl sulfate, diallyldiethyl ammonium methyl ethyl sulfate, diallyldiethyl ammonium ethyl sulfate, diallyldiethyl (hydroxyethyl) ammonium methyl ethyl sulfate, and diallylethyl (hydroxyethyl) ammonium ethyl sulfate. In this case, the hydroxyethyl group is preferably a 2-hydroxyethyl group.

In addition, in the present invention, the first and second substrates,

(1) among these copolymers, as the (meth) acrylamide compound to be reacted, at R⁴Is an acrylamide in the case of a hydrogen atom, and R is⁴In the case of methyl, it is a methacrylamide.

(2) Furthermore, R⁵、R⁶Each independently represents a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, or a cycloalkyl group having 2 to 7 carbon atoms which may have an ether bond.

(3) Furthermore, R⁵、R⁶R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms and having a hydroxyl group⁵、R⁶Each independently is preferably a hydrogen atom, an alkyl group having 1 to 2 carbon atoms, or a 2-hydroxyalkyl group having 2 to 3 carbon atoms.

Thus, examples of the (meth) acrylamide include acrylamide, N-methacrylamide, N-ethylacrylamide, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxypropyl) acrylamide, N-dimethylacrylamide, N-methyl-N-ethylacrylamide, N-diethylacrylamide, N-methyl-N- (2-hydroxyethyl) acrylamide, N-methyl-N- (2-hydroxypropyl) acrylamide, N-ethyl-N- (2-hydroxyethyl) acrylamide, N-ethyl-N- (2-hydroxypropyl) acrylamide, methacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-ethylacrylamide, N-ethyla, N-ethylmethacrylamide, N- (2-hydroxyethyl) methacrylamide, N- (2-hydroxypropyl) methacrylamide, N-dimethylmethacrylamide, N-methyl-N-ethylmethacrylamide, N-diethylmethacrylamide, N-methyl-N- (2-hydroxypropyl) methacrylamide, N-ethyl-N- (2-hydroxypropyl) methacrylamide, and the like.

Furthermore, R⁵、R⁶When a cycloalkyl group having 2 to 7 carbon atoms which may contain an ether bond is formed together, the amino moiety of the (meth) acrylamide is preferably a morpholinyl group, a piperidinyl group or a pyrrolidinyl group.

In this case, examples of the (meth) acrylamide include acryloylmorpholine, acryloylpiperidine, acryloylpyrrolidine, methacryloylmorpholine, methacryloylpiperidine, methacryloylpyrrolidine, and the like.

In addition, these copolymers of the present invention are exemplified by diallyl ethyl methyl ammonium sulfate copolymers, including copolymers of diallyl ethyl methyl ammonium sulfate and acrylamide with sulfur dioxide, copolymers of diallyl ethyl methyl ammonium sulfate and N-methacrylamide with sulfur dioxide, copolymers of diallyl ethyl methyl ammonium sulfate and N-ethyl acrylamide with sulfur dioxide, copolymers of diallyl ethyl methyl ammonium sulfate and N, N-dimethylacrylamide with sulfur dioxide, copolymers of diallyl ethyl methyl ammonium sulfate and N-methyl-N-ethylacrylamide with sulfur dioxide, copolymers of diallyl ethyl methyl ammonium sulfate and N, N-diethylacrylamide with sulfur dioxide, copolymers of diallyl ethyl methyl ammonium sulfate and N- (2-hydroxyethyl) acrylamide with sulfur dioxide Copolymers, copolymers of diallylethylmethylammonium methylsulfate and N- (2-hydroxypropyl) acrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-methyl- (2-hydroxyethyl) acrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-methyl- (2-hydroxypropyl) acrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-ethyl- (2-hydroxyethyl) acrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-ethyl- (2-hydroxypropyl) acrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and acryloylmorpholine with sulfur dioxide, copolymers of allylethylmethylammonium methylsulfate and N-ethyl- (2-hydroxypropyl) acrylamide with sulfur dioxide, copolymers, Copolymers of diallylethylmethylammonium methylsulfate and acryloyl piperidine with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and acryloyl pyrrolidine with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and methacrylamide with sulfur dioxide, copolymers of diallylethylmethylmethylammonium methylsulfate and N-methylmethacrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-ethylmethacrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N, N-dimethylmethacrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-methyl-N-ethylmethacrylamide with sulfur dioxide, diallylethylmethylammonium methylsulfate and N, copolymers of N-diethylmethacrylamide and sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N- (2-hydroxyethyl) methacrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N- (2-hydroxypropyl) methacrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-methyl- (2-hydroxyethyl) methacrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-methyl- (2-hydroxypropyl) methacrylamide with sulfur dioxide, copolymers of diallylethylmethylmethylammonium methylsulfate and N-ethyl- (2-hydroxyethyl) methacrylamide with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate and N-ethyl- (2-hydroxypropyl) methacrylamide Copolymers of amides with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate with methacryloylmorpholine with sulfur dioxide, copolymers of diallylethylmethylammonium methylsulfate with methacryloylpiperidine with sulfur dioxide, copolymers of diallylethylmethylmethylammonium methylsulfate with methacryloylpyrrolidine with sulfur dioxide, and the like.

In addition, in other diallyl ethylmethyl ammonium sulfate-based copolymers exemplified above, instead of the monomer diallyl ethylmethyl ammonium sulfate, copolymers using diallyl dimethyl ammonium methyl sulfate, diallyl diethyl ammonium methyl sulfate, diallyl (hydroxyethyl) methyl ammonium sulfate, diallyl ethyl (hydroxyethyl) methyl ammonium sulfate, diallyl dimethyl ammonium ethyl sulfate, diallyl ethylmethyl ammonium sulfate, diallyl diethyl ammonium ethyl sulfate, diallyl (hydroxyethyl) methyl ammonium sulfate, diallyl ethyl (hydroxyethyl) ethyl ammonium sulfate, and the like can be also cited.

Among these copolymers, the monomer molar ratio of diallyldialkyl ammonium alkyl sulfate/(meth) acrylamide/sulfur dioxide is usually 1/(0.001 to 100)/(0.001 to 1), preferably 1/(0.005 to 10)/(0.005 to 1), more preferably 1/(0.01 to 10)/(0.01 to 1), particularly preferably 1/(0.05 to 5)/(0.05 to 1), and most preferably 1/(0.08 to 3)/(0.05 to 1), from the viewpoint of stability of the resulting copolymer.

The molecular weight of the copolymer of the present invention is usually 300 to 50,000, preferably 500 to 25,000, and more preferably 800 to 10,000 in terms of the weight average molecular weight of polyethylene glycol converted by a Gel Permeation Chromatography (GPC) method.

The method for producing these copolymers is not particularly limited, and a desired copolymer can be efficiently produced by the following method, for example.

Namely, in a polar solvent, by reacting diallyldialkylammonium alkylsulfate represented by general formula (XVI)

[ solution 11]

[ in the formula, R¹、R²、R³Each as described above. ]

With (meth) acrylamides of the general formula (XVII)

[ solution 12]

[ in the formula, R⁴、R⁵、R⁶Respectively, as described above. ]

And sulfur dioxide, whereby the copolymer used in the present invention can be obtained.

Thus, examples of the diallyldialkyl ammonium alkyl sulfate monomer used in the present invention include diallyldimethyl ammonium methyl sulfate, diallylethyl ammonium methyl sulfate, diallyldiethyl (hydroxyethyl) ammonium methyl sulfate, diallylethyl (hydroxyethyl) ammonium methyl sulfate, diallyldimethyl ammonium ethyl sulfate, diallylethyl ammonium methyl ethyl sulfate, diallyldiethyl ammonium methyl ethyl sulfate, diallyldiethyl ammonium ethyl (hydroxyethyl) ammonium methyl ethyl sulfate, and diallylethyl (hydroxyethyl) ammonium ethyl sulfate, and these monomers are suitably used. The hydroxyethyl group as the monomer is preferably a 2-hydroxyethyl group.

The monomer of diallyldialkylammonium alkylsulfate used herein can be suitably produced, for example, by alkylation reaction of diallylalkylamine with dialkylsulfuric acid.

That is to say that the first and second electrodes,

(1) diallyl dimethyl ammonium methosulfate, diallyl ethyl ammonium methosulfate, and diallyl (hydroxyethyl) ammonium methosulfate can be produced by a methylation reaction in which dimethyl sulfuric acid is added to diallyl methylamine, diallyl ethylamine, and diallyl (hydroxyethyl) amine, respectively, and reacted.

(2) Further, diallyl diethyl ammonium ethyl sulfate, diallyl ethyl methyl ammonium ethyl sulfate, and diallyl ethyl (hydroxyethyl) ammonium ethyl sulfate can be produced by an ethylation reaction in which diethyl sulfuric acid is added to diallyl ethylamine, diallyl methylamine, and diallyl (hydroxyethyl) amine, respectively, and reacted.

Furthermore, with respect to the (meth) acrylamides used as monomers, in the above general formula (XVII), R⁴In the case of a hydrogen atom, is an acrylamide compound, and in the other hand, R is⁴In the case of methyl, it is a methacrylamide. Furthermore, these R' s⁵、R⁶Independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms and having a hydroxyl group, or a cycloalkyl group having 2 to 7 carbon atoms and having an ether bond. R⁵、R⁶When each is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms and having a hydroxyl group, R is preferably⁵、R⁶Each independently represents a hydrogen atom, an alkyl group having 1 to 2 carbon atoms, or a 2-hydroxyalkyl group having 2 to 3 carbon atoms.

In this case, the (meth) acrylamide includes acrylamide, N-methacrylamide, N-ethylacrylamide, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxypropyl) acrylamide, N-dimethylacrylamide, N-methyl-N-ethylacrylamide, N-diethylacrylamide, N-methyl-N- (2-hydroxyethyl) acrylamide, N-methyl-N- (2-hydroxypropyl) acrylamide, N-ethyl-N- (2-hydroxyethyl) acrylamide, N-ethyl-N- (2-hydroxypropyl) acrylamide, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-ethylacrylamide, n-ethylmethacrylamide, N- (2-hydroxyethyl) methacrylamide, N- (2-hydroxypropyl) methacrylamide, N-dimethylmethacrylamide, N-methyl-N-ethylmethacrylamide, N-diethylmethacrylamide, N-methyl-N- (2-hydroxyethyl) methacrylamide, N-methyl-N- (2-hydroxypropyl) methacrylamide, N-ethyl-N- (2-hydroxyethyl) methacrylamide, N-ethyl-N- (2-hydroxypropyl) methacrylamide, and the like.

Furthermore, R⁵、R⁶When a cycloalkyl group having 2 to 7 carbon atoms which may contain an ether bond is formed together, it is preferable that the amino moiety of the (meth) acrylamide is a morpholinyl group, a piperidinyl group or a pyrrolidinyl group. In this case, for example, the (meth) acrylamide may be acryloyl morpholine, acryloyl piperidine, acryloyl pyrrolidine, methacryloyl morpholine, methacryloyl piperidine, methacryloyl pyrrolidine, or the like.

Therefore, the polar solvent used in the production of these copolymers is a solvent capable of dissolving diallyl dialkyl ammonium alkyl sulfate, (meth) acrylamides and sulfur dioxide, and examples thereof include water, methanol, ethanol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide and the like, and in the present invention, these solvents may be used alone in any 1 kind, or may be used in any combination of two or more kinds.

In addition, in the production of these copolymers, the polymerization catalyst used in the radical copolymerization reaction is not particularly limited as long as it is a catalyst capable of polymerizing diallyldialkyl ammonium alkyl sulfate with (meth) acrylamides and sulfur dioxide, and examples thereof include organic peroxides such as t-butyl hydroperoxide and cumene hydroperoxide, aliphatic azo compounds such as 2, 2' -azobisisobutyronitrile, inorganic peroxides such as ammonium persulfate and potassium persulfate, nitrates such as ammonium nitrate and potassium nitrate, and the like. Further, oxygen-containing gas such as air, radiation, ultraviolet rays, and visible light can be cited.

In addition, in the production of these copolymers, the molar ratio of the charged monomer of ammonium diallyldialkyl sulfate/(meth) acrylamide/sulfur dioxide is usually 1/(0.001 to 100)/(0.001 to 1), preferably 1/(0.005 to 10)/(0.005 to 1), more preferably 1/(0.01 to 10)/(0.01 to 1), particularly preferably 1/(0.05 to 5)/(0.05 to 1), and most preferably 1/(0.08 to 3)/(0.05 to 1), from the viewpoint of stability of the resulting copolymer.

In addition, in the production of these copolymers, the above polymerization catalyst is usually added to a polar solvent solution containing the above diallyl dialkyl ammonium alkyl sulfate, the (meth) acrylamides and sulfur dioxide, and copolymerization is carried out by applying an appropriate stirring operation at room temperature or under heating. The polymerization temperature is preferably from-100 ℃ to 80 ℃. The polymerization time is preferably 1 to 100 hours. After the reaction is completed, a solvent such as ethanol or acetone, which does not dissolve the copolymer, may be added to reprecipitate the copolymer and recover it.

As is clear from the above, the thus obtained copolymer of "diallyldialkyl ammonium alkyl sulfate" - "(meth) acrylamide" - "sulfur dioxide" is adsorbed as a leveling agent for plating on the convex portion on the surface of the plating object, and is excellent in the effect of suppressing plating deposition on the convex portion. Further, the copolymer, as one component of the acidic copper plating bath composition used in the present invention, exerts the following characteristics: the plated surface is excellent in plating spreadability in the interior or at the corner of a blind via or a through hole and leveling of the plated surface, and can cope with a poor substrate. Further, by using such an acidic copper plating bath composition, a copper plating treatment can be performed with high reliability on a substrate having micro holes such as through holes and blind vias, or on a resin film whose surface is coated with a metal such as copper.

In the present invention, the concentration of the leveling agent component for plating (F) constituting the acidic copper plating bath composition is preferably used in a concentration range of 10 to 1200mg/L, and particularly preferably in a concentration range of 50 to 500mg/L, in the acidic copper plating bath composition.

< polyimide resin film substrate used in the present invention >

As described in detail above, electronic devices such as mobile phones, personal computers, televisions, video recorders, music players, digital cameras, game machines, and the like are actually becoming thinner, more dense, smaller, and lighter in technical fields, and various components used in these electronic devices are also becoming more dense and smaller. In addition, as a substrate material for mounting these components, polyimide resin films, for example, Printed Wiring Boards (PWB), flexible printed wiring boards (FPC), tape for Tape Automated Bonding (TAB), Chip On Film (COF) tapes, and the like are widely used as insulating substrate materials for electronic components.

Therefore, the polyimide resin film used in the present invention is usually an aromatic polyimide in which aromatic compounds are directly bonded to each other with imide bonds, and the aromatic compounds have a conjugated structure through the imide bonds, and the imide bonds having strong intermolecular forces have the highest thermal, mechanical, and chemical properties among polymers, and as can be seen from the following examples, the present invention uses a trade name manufactured by "chinese character" レ "," デュポン: カプトン 100-EN.

< the two-layer flexible copper-clad laminate substrate of the present invention and the method for producing the same >

Therefore, a method for producing a two-layer flexible copper-clad laminate substrate (two-layer FCCL) according to the present invention is described below, wherein a seed layer of a conductive metal such as Ni or an alloy thereof is formed in advance using a polyimide resin film material, and all steps of thick plating the seed layer with the above-described acidic copper plating bath composition to form a copper conductive layer are wet processes, and unlike the conventional copper plating method, all copper plating steps are 1 step, thereby producing a two-layer flexible copper-clad laminate substrate (two-layer FCCL).

According to the present invention, there is provided,

(1): a pretreatment step is performed for modifying the surface of a polyimide resin film having excellent flexibility, heat resistance and chemical resistance to make the film hydrophilic. Unlike conventional atmospheric pressure plasma treatment, corona treatment, and ion irradiation treatment under vacuum, this surface modification method forms a polyamic acid modified layer on the surface thereof by an alkaline wet modification method. Then, Pd ions are adsorbed on the surface of the substrate by a palladium (Pd) -based catalyst, and then reduction treatment is performed, thereby obtaining a hydrophilic surface-modified layer [ Pd ion adsorption ] → [ reduction metallization ].

That is, according to a series of changes of the alkaline wet modification method, in general, when a polyimide resin is treated with an alkaline aqueous solution, a part of the surface thereof is hydrolyzed, and a part of the imide ring is cleaved to generate an amide group and a carboxyl group. The carboxyl groups thus formed are easily cation-exchanged, and thus can adsorb metal ions.

(2) A seed layer of a conductive metal is formed by plating a conductive metal such as Ni or an alloy thereof on the surface of the resin film thus modified on the hydrophilized surface by electroless plating, examples of the alloy of Ni include alloys such as Ni-P, Ni-B, Ni-Cu, and Ni-Cr is formed in a thickness of 40 to 3000 Å by sputtering in general, and in the present invention, a seed layer plated with electroless Ni or an alloy thereof in a thickness of 10 to 300nm is formed by FCCL electroless plating manufactured by Perma ユージライト (Co., Ltd.).

(3): then, the acid copper plating bath composition of the present invention is subjected to wet plating without 1-time copper plating as strike copper plating, and a copper conductive layer is thickly plated on the seed layer of the resin film while controlling the layer thickness as desired in one step, thereby producing a two-layer flexible copper-clad laminate substrate having a copper-clad thickness in the range of 0.05 to 50 μm of the present invention.

In addition, in the method of performing the copper plating treatment on the resin film material having the metal coating formed on the surface thereof, for example, in the conventional method, the seed layer is formed by dry coating a metal such as copper, nickel, or chromium having a thickness of about 4 to 3000nm, or a "nickel-chromium" alloy, on the surface of a resin film such as polyimide or polyester having a thickness of about 12 to 50 μm by vacuum deposition, sputtering, or the like, whereas in the present invention, the wet electroless nickel plating treatment by the FCCL electroless nickel plating method as described above is performed to form the conductive nickel seed layer having a thickness of about 10 to 300 nm.

In this way, the condition for copper plating of the resin thin film having a metal coating film formed on the surface thereof with the acidic copper plating bath composition of the present invention is preferably a condition for copper plating with sulfuric acid, which is generally used. That is, the average cathode current density is 1 to 3A/dm at a liquid temperature of about 23 to 27 DEG C²Plating is performed for about 0.1 to 250 minutes from the left and right sides. The plating thickness is about 0.05 to 50 μm. In general, it is preferable to perform copper plating under liquid agitation by aeration or the like.

In addition, in the conventional method (particularly, the metal spraying method), when a resin thin film coated with an extremely thin metal is plated in a conventional acidic copper plating bath in the steps of vacuum deposition, sputtering, and the like, and the plating thickness is less than 10 μm, there are problems such as the following: the leveling effect of the additive cannot be exhibited, and a rough surface state with a large number of surface irregularities is formed, and a glossy appearance cannot be obtained, but in the present invention, the "acidic copper plating bath composition" used makes it possible to form a very fine crystal state on the surface even at such a thin plating thickness (about 3 to 5 μm thickness), and to obtain a smooth glossy copper plated surface with high reliability. Even if the plating thickness is thicker than the above, it is needless to say that a good glossy appearance can be obtained.

As described above, the method for manufacturing a two-layer flexible copper-clad laminate substrate (two-layer FCCL) according to the present invention is a method for manufacturing a two-layer FCCL, which is characterized by including a seed layer formed by electroless Ni plating that is significantly inexpensive and capable of realizing in-line plating, and all the steps are wet processes (all wet processes), and the obtained two-layer flexible copper-clad laminate substrate is applicable to fine patterning, as compared to a conventional method (particularly, a method for manufacturing a two-layer FCCL by a metallization method (sputtering/plating method)) that is expensive in equipment, high in running cost, requires a vacuum step, and low in productivity.

As has been described above, the present invention is also characterized by suitably providing an acidic copper plating bath composition used in the present invention, which comprises (a) a copper ion component, (B) an organic acid and/or an inorganic acid component, (C) a chloride ion component, (D) an organic polymer component, (E) a brightener component, and (F) a copolymer component of ammonium diallyldialkyl sulfate and (meth) acrylamides and sulfur dioxide as a leveling agent for plating, as a plating treatment agent for producing a two-layer flexible copper-clad laminate base material of the present invention.

Further, by using such an acidic copper plating bath composition as a plating treatment agent for producing a two-layer flexible copper-clad laminate base material of the present invention, a two-layer flexible copper-clad laminate base material (two-layer FCCL) produced by thickly plating copper without plating the surface of the resin film on which the seed layer of the conductive metal coating film is formed in advance with 1 copper plating is provided with a smooth glossy appearance, and it is also known from the following examples that the present invention is also characterized in that the peeling resistance of the obtained copper plating layer can be greatly improved.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1

(1) The leveling agent for plating (F), which is one component of the "acidic copper plating bath composition-1" used in the present invention, was prepared in the following manner, namely a terpolymer component of [ diallylethylmethylammonium ethylsulfate ] and [ acrylamide ] and [ sulfur dioxide ].

167.1g (1.5 mol) of diallylmethylamine was charged into a 1L four-necked round-bottomed separable flask equipped with a stirrer, a thermometer and a serpentine (ジムロート -type) reflux condenser, 232.5g (1.5 mol) of diethyl sulfate held at 20 to 50 ℃ was slowly dropped while stirring, and after the mixture was reacted at 50 ℃ for 24 hours, 212.9g of water was added to prepare a "diallylethylmethylammonium sulfate monomer aqueous solution" having a concentration of 65 mass%.

Subsequently, to the 65 mass% aqueous solution of diallylethyl ammonium methyl ethyl sulfate monomer (abbreviated as DAEMAES monomer) (monomer content: 1.5 mol), water was added to adjust the monomer concentration to 60 mass%, and while cooling and stirring were performed under ice water, sulfur dioxide was added in an equivalent molar amount to the DAEMAES monomer, and 13.3g (0.19 mol) of acrylamide was added and dissolved. Then, while maintaining the obtained mixture of DAEMAES monomer, acrylamide and sulfur dioxide at 60 ℃, 71.3g (4.0 mass% based on the total monomers) of an aqueous Ammonium Persulfate (APS) solution having a concentration of 28.5 mass% was added in portions and subjected to copolymerization reaction for 48 hours to thereby prepare [ diallylethylmethylammonium ethylate ]: [ acrylamide ]: [ sulfur dioxide ] ═ 8: 1: 8 to obtain a leveling agent aqueous solution for plating, namely a terpolymer-1 of diallyl ethyl methyl ammonium ethosulfate, acrylamide and sulfur dioxide, namely (F).

Then, a part of the obtained solution was reprecipitated with acetone, and the obtained white solid was filtered off and vacuum-dried at 50 ℃ for 48 hours. From the IR spectrum of the resulting white powdery terpolymer, it was found to be 1320cm^-1And 1130cm^-1Is attributed to-SO₂Absorption of (E), 1220cm^-1There is an absorption ascribed to the sulfate and 1680cm^-1The absorption band of amide was observed, and it was confirmed that the terpolymer was a terpolymer of diallylethyl ammonium methyl ethyl sulfate, acrylamide and sulfur dioxide (molar ratio 8: 1: 8).

The weight average molecular weight (Mw) of the terpolymer was 1500 as measured by the following method, and the polymerization yield was 95.0% as measured by the following method. The terpolymer was provided to the leveling agent in the acidic copper plating bath composition in the following examples.

(2) Composition of acidic copper plating bath composition

< acidic copper plating bath composition-1 >

(A) A copper ion component; copper sulfate pentahydrate 120g/L

(B) An inorganic acid component; 150g/L sulfuric acid

(C) A chloride ion component; chlorine 50mg/L

(D) An organic polymer component; polyethylene glycol^＊1　　　　　　　　　 2000mg/L

(E) A brightener component; SPS^＊2　　　　　　　　　　　　　 1mg/L

(F) A leveling agent component for plating; terpolymer-1500 mg/L

[ Note ] ＊ 1: HO- (C)₂H₄O）_n-H n＝90

　＊2：NaO₃S-C₃H₆-S-S-C₃H₆-SO₃Na

(3) Then, a resin film material coated with an electroless nickel plating-coated polyimide film (manufactured by seed レ seed デュポン, trade name: カプトン 100-EN) was subjected to plating with a thickness of 10 μm using the "acidic copper plating bath composition-1" without copper plating 1 time by FCCL electroless nickel plating method manufactured by egoma ユージライト (ltd).

The plating conditions of the wet plating are as follows: at 25 ℃ and an average cathodic current density of 2A/dm²Then, acid copper plating was performed for 25 minutes under aeration agitation. Then, the film surface of the obtained two-layer flexible copper-clad laminated polyimide film substrate was visually observed to be extremely smooth and to exhibit a remarkable glossy appearance. Further, "peel resistance between Ni and Cu" and "long-term heat resistance test (90 ° peel strength)" were measured and evaluated, and the results are shown in table 1.

Hereinafter, various methods of evaluating physical properties and methods of measuring strength according to the present invention are described.

< peeling resistance between Ni and Cu >

When the resin film side of the test piece having a length of 10cm and a width of 1cm of the copper-coated resin film material was baked with fire for several seconds, peeling occurred between the resin film and the coated metal. When the resin film and the coating metal were peeled off by hand, no metal remained on the film in general, but when peeling occurred between them, Ni of the seed layer remained on the film, and thus the presence or absence of the state change was visually judged.

< Long-term Heat resistance test (90 ℃ peel Strength) >)

＜JIS C 6471＞

A test piece was prepared by cutting a 10 mm-wide cut into a two-layer FCCL resin film material and exposed to a long-term heat resistance test (150 ℃ C.. times.168 Hr), and the 90 ℃ peel strength N/m was measured in accordance with JIS C6471. As a resin film material for test pieces, カプトン 100-EN produced by chinese yards レ (seeds) or chinese yards デュポン (plants) was used.

The device is a tensile testing machine and a recorder of the stripping force, wherein the error of the device is +/-1% of the indicated value in the scale of the effective light weight range, the load during continuous recording stripping is 15-85% of the capacity of the testing machine, and the speed of the cross magnetic head is kept at about 50mm per minute. Further, the test piece also includes an indicator having a function of keeping the angle of the copper foil peeling direction to the copper foil removing surface of the sample at 90 ± 5 °. The indicator used was fixed to a tensile testing machine after measuring the conductor width of the sample, and was slidable in the tensile direction and the vertical direction in synchronization with the peeling speed. In addition, "normal state (normality)" shown in table 1 indicates measured values in normal temperature and normal pressure air at 20 to 30 ℃.

< weight average molecular weight (Mw) > < copolymer

The weight average molecular weight (Mw) of the copolymer was measured by gel permeation chromatography (GPC method) using Hitachi L-6000 high performance liquid chromatography. Hitachi L-6000 was used as an eluent flow pump, a differential refractive index detector of ショーデックス RI-101 was used as a detector, and a ショーデックスアサヒパック water-based gel filtration type chromatographic column of GS-220 HQ (molecular weight exclusion limit 3,000) and GS-620 HQ (molecular weight exclusion limit 200 ten thousand) connected in series was used as a column. The sample was adjusted to a concentration of 0.5g/100ml with an eluent, and 20. mu.l was used. The eluent was 0.4 mol/l aqueous sodium chloride solution.

The reaction was carried out at a column temperature of 30 ℃ and a flow rate of 1.0 ml/min. Polyethylene glycols having molecular weights of 106, 194, 440, 600, 1470, 4100, 7100, 10300, 12600, 23000, and the like are used as standard substances, and a calibration curve is prepared, and the weight average molecular weight (Mw) of the copolymer is determined based on the calibration curve.

< polymerization yield of copolymer >

The peak area ratio was determined by GPC.

Comparative example 1

Except that "sulfuric acid copper plating bath composition H-1" shown below was used in place of "acidic copper plating bath composition-1" in example 1, plating was performed in the same manner as in example 1, and the appearance and the peel resistance between "Ni — Cu" of the plated substrate were evaluated in various ways, and the results are shown in table 1.

< acidic copper plating bath composition H-1 >

(A) Copper sulfate pentahydrate 120g/L

(B) 150g/L sulfuric acid

(C) Chloride ion 50mg/L

CU-BRITE TH-R-A^＊3　　　　　　40ml/L

CU-BRITE TH-R-B^＊4　　　　　　　　　　 2.5ml/L

＊ 3 contains additives containing hydrocarbon organic compound and nitrogen organic compound as main ingredients, which are prepared from Perilla frutescens ユージライト.

＊ 4 contains sulfur-containing organic compound as main ingredient, similar to ＊ 3, and is prepared from Perilla frutescens ユージライト (trademark).

Comparative example 2

Except that "sulfuric acid copper plating bath composition H-2" shown below was used in place of "acidic copper plating bath composition-1" in example 1, plating was performed in the same manner as in example 1, and the appearance and the peel resistance between "Ni — Cu" of the plated substrate were evaluated in various ways, and the results are shown in table 1.

< acidic copper plating bath composition H-2 >

(A) Copper sulfate pentahydrate 120g/L

(B) 150g/L sulfuric acid

(C) Chloride ion 50mg/L

CU-BRITE TH^＊5　　　　　　　　　　　　 5ml/L

＊ 5 additive containing hydrocarbon organic compound, nitrogen organic compound and sulfur organic compound as main ingredients, similar to ＊ 3

Comparative example 3

Plating was performed in the same manner as in example 1 except that "sulfuric acid copper plating bath composition H-3" shown below was used instead of "acidic copper plating bath composition-1" in example 1, and the appearance and various evaluations of "peeling resistance between Ni and Cu" were performed on the plated substrate, and the results are shown in table 1.

< acidic copper plating bath composition H-3 >

(A) Copper sulfate pentahydrate 120g/L

(B) 150g/L sulfuric acid

(C) Chloride ion 50mg/L

(D) Polyethylene glycol^＊1　　　　　　　　　　　　　500mg/L

（E）SPS^＊2　　　　　　　　　　　　　　　1mg/L

(F) A leveling agent component; copolymer-2^＊6　　　　 1000mg/L

[ Note ] ＊ 1: HO- (C)₂H₄O）_n-H n＝90

＊2：NaO₃S-C₃H₆-S-S-C₃H₆-SO₃Na

＊ 6 alternating copolymer of diallyl ethyl ammonium methyl sulfate and sulfur dioxide in a molar ratio of 1/1

Example 2

In example 2, a test piece for evaluating the elongation (JIS Z2241) was prepared.

The "acidic copper plating bath composition-2" having a composition of components substantially the same as that of the "acidic copper plating bath composition-1" used in example 1 was used to measure and evaluate the elongation (JIS Z2241) of a SUS plate subjected to copper plating treatment by the same plating process as in example 1, and the results are shown in table 2.

Current conditions: 2A/dm²Film formation at 60 μm, temperature: 25 deg.C

< acidic copper plating bath composition-2 >

(A) Copper ion composition: copper sulfate pentahydrate 120g/L

(B) Inorganic acid component: 150g/L sulfuric acid

(C) Chloride ion composition: chlorine 50mg/L

(D) Organic polymer component: polyethylene glycol^＊1　　　　　　　　 2000mg/L

(E) The brightener comprises the following components: SPS^＊2　　　　　　　　　　　　　 2mg/L

(F) Leveling agent component for plating: terpolymer-1^＊7　　　　　　100mg/L

[ Note ] ＊ 1: HO- (C)₂H₄O）_n-H n＝90

＊2：NaO₃S-C₃H₆-S-S-C₃H₆-SO₃Na

＊ 7 copolymer of diallyl ethyl methyl ammonium ethyl sulfate and acrylamide with molar ratio of sulfur dioxide of 8/1/8

Comparative example 4

The elongation (JIS Z2241) of "acidic copper plating bath composition H-4" was measured and evaluated in the same manner as in example 2 except that "acidic copper plating bath composition H-4" shown below was used in place of "acidic copper plating bath composition-2" in example 2, and the results are shown in Table 2.

< acidic copper plating bath composition H-4 >

(A) Copper sulfate pentahydrate 120g/L

(B) 150g/L sulfuric acid

(C) Chloride ion 50mg/L

(D) Polyethylene glycol^＊1　　　　　　　　　　　　　　　1000mg/L

[ Note ] ＊ 1: HO- (C)₂H₄O）_n-H n＝90

As described above, as is clear from tables 1 and 2, the two-layer flexible copper-clad laminate substrate obtained by the manufacturing method in which the overall process is a wet process of the present invention clearly exhibits the characteristics of the "acidic copper plating bath composition" used in conjunction with the wet process, and has a glossy appearance and remarkably excellent copper layer peeling resistance as compared with the "copper plating layer" that has not been obtained by the conventional method.

In particular, the two-layer flexible copper-clad laminate base material of the present invention exhibits a heat resistance strength (heat-resistant adhesion) of 400N/m or more similar to that of a two-layer substrate material formed by a sputtering method or a metal spraying method in a "long-term heat resistance test (90 ° peel strength)", and is therefore very highly useful.

[ Table 1]

[ Table 2]

	Elongation (%)
		Example 2	20.1
Comparative example 4	3.8

Industrial applicability

As described above, the present invention provides a copper metal-coated resin film substrate having a smooth glossy appearance and excellent peeling resistance, which is a two-layer flexible copper clad laminate substrate (two-layer FCCL) formed by thick plating of copper without 1-time copper plating of a metal-coated resin film having a conductive Ni or an alloy seed layer thereof by FCCL electroless plating using a newly developed acidic copper plating bath composition.

In addition, in the present invention, when the electroless plating method is used for seed layer formation, a wet thick plating copper layer is formed by wet copper plating in one step without performing copper plating 1 time on the conductive Ni or its alloy seed layer, by taking advantage of the characteristics of the acidic copper plating bath composition used, thereby providing a two-layer flexible copper clad laminate substrate (two-layer FCCL) that is extremely easy to be finely patterned.

In addition, in the present invention, by making all the steps of forming a seed layer, thick plating a copper conductive layer thereof, and the like, wet processes and making all the copper plating steps a single step, taking into account the characteristics of the acidic copper plating bath composition and the like used, a two-layer flexible copper clad laminate substrate (two-layer FCCL) having a smooth glossy appearance, exhibiting excellent peeling resistance, and having a copper-coated surface that is easily finely patterned can be manufactured, and thus, a method for manufacturing a two-layer FCCL that can be manufactured with a simple apparatus, low running cost, remarkably high reliability, and high productivity is provided.

Claims

1. A two-layer flexible copper-clad laminate base material characterized in that a resin film substrate having a modified hydrophilized surface is coated with a conductive metal seed layer of Ni or an alloy thereof having a coating thickness in the range of 10 to 300nm formed in advance by an electroless plating method, and is subjected to thick plating with a coating thickness in the range of 0.05 to 50 μm by copper plating using an acidic copper plating bath composition without being subjected to 1 copper plating as strike copper plating.

2. The two-layer flexible copper-clad laminate substrate according to claim 1, wherein the resin film substrate is a polyimide film having a conductive metallic nickel seed layer applied thereto in advance by an electroless plating method.

3. The two-layer flexible copper-clad laminate substrate according to claim 1 or 2, wherein the acidic copper plating bath composition is composed of (a) a copper ion component, (B) an organic acid and/or an inorganic acid component, (C) a chloride ion component, (D) an organic polymer component, (E) a brightener component, and (F) a copolymer component of ammonium diallyldialkyl alkyl sulfate and (meth) acrylamides and sulfur dioxide as a leveling agent for plating.

4. A method for manufacturing a two-layer flexible copper-clad laminate substrate (two-layer FCCL) by wet thick plating using an acidic copper plating bath composition and a resin film coated with a conductive metal as a seed layer, the method comprising:

forming a conductive metal plating seed layer with a coating thickness of 10 to 300nm on the surface of the resin film subjected to hydrophilization surface modification by an electroless plating method;

and a step of plating a copper conductive layer on the seed layer in a thickness of 0.05 to 50 μm without performing a wet plating treatment without performing 1-time copper plating as strike copper plating in the acidic copper plating bath composition.

5. The method for manufacturing a two-layer flexible copper-clad laminate substrate according to claim 4, wherein the conductive metal serving as a seed layer is any one of Ni and an alloy thereof.

6. The method for producing a two-layer flexible copper-clad laminate substrate according to claim 4 or 5, wherein the resin film is a polyimide film having a conductive metallic nickel seed layer applied thereto in advance by an electroless plating method.

7. The method for producing a two-layer flexible copper-clad laminate base material according to any one of claims 4 to 6, wherein the acidic copper plating bath composition comprises (A) a copper ion component, (B) an organic acid and/or an inorganic acid component, (C) a chloride ion component, (D) an organic polymer component, (E) a brightener component, and (F) a copolymer component of diallyl dialkyl ammonium alkyl sulfate and (meth) acrylamides and sulfur dioxide as a leveling agent for plating.

8. The method for producing a two-layer flexible copper-clad laminate substrate according to claim 7, wherein the organic polymer component (D) is at least 1 species selected from the group consisting of polyethylene glycol, polypropylene glycol, pluronic type surfactants, ferronic type surfactants, polyethylene glycol seeded and seeded ethers, and polyethylene glycol seeded and seeded dialkyl ethers.

9. The method for producing a two-layer flexible copper-clad laminate substrate according to claim 7 or 8, wherein the (E) brightener component is at least 1 selected from sulfoalkylsulfonates, organic disulfide compounds, and dithiocarbamic acid derivatives.