TWI449481B - Manufacturing method for circuit wiring board - Google Patents

Description

Circuit wiring substrate manufacturing method

The present invention relates to a method of manufacturing a circuit wiring board used in an electronic component, and more particularly to a method of manufacturing a circuit wiring board formed by forming a circuit wiring having a pattern on a polyimide film.

As for the electronic circuit of an electronic device, a printed wiring board which performs circuit processing on a laminated board which consists of an insulating material and a electrically-conductive material is used. The printed wiring board is formed on the surface (and inside) of the insulating substrate by a conductive material, and the conductor pattern according to the electrical design is fixed. According to the type of the insulating resin as the substrate, the rigid printed wiring board can be roughly classified into a plate shape. A flexible printed wiring board that is flexible. A flexible printed wiring board is characterized in that it has flexibility and is a necessary component for connection in a movable portion that is often repeatedly flexed. Further, since the flexible printed wiring board can be housed in a state of being bent in the electronic device, it can also be used as a space-saving wiring material. As a substrate of a flexible substrate which is a material of a flexible printed wiring board, an insulating resin such as a polyimide or a polyimide resin, which is used in a heat-resistant polyimide resin, is often used. Absolutely large. On the other hand, in the case of a conductive material, in terms of conductivity, a copper foil is usually used.

In recent years, with the miniaturization of electronic components and the speed of signal transmission, fine pitch circuits have been required for circuit boards such as flexible printed wiring boards. As a method of forming a fine fine pitch circuit, a method such as a vapor deposition method or a sputtering method is known, and the metal film formed by such a method has a deviation from the adhesion strength of the polyimide film substrate. Large, or pinholes are easily generated in the wiring, which is a problem. Furthermore, in the above method, since the step of removing an unnecessary sead layer on the polyimide film by the etching treatment is performed, excessive etching may occur due to etching of the wiring by the etching liquid. concern.

In recent years, as a method for maintaining the adhesion between a relatively good polyimide substrate and a metal film, a method which has been proposed is, for example, a direct metalization disclosed in Patent Document 1. Method of law. A part of the metal film obtained by such a method is embedded in a resin of a polyimide resin substrate to obtain high adhesion. The proposal has a method of applying this direct metallization without the need for etching of the seed layer. For example, in Patent Document 2, it has been revealed that a microscopic flow path having a pattern shape is formed on the surface of a polyimide resin substrate, and an alkali solution is supplied into the micro flow path to form a modified surface on the surface of the polyimide resin substrate. After the layer, metal ions are brought into contact with the reforming layer to reduce the metal ions to form a metal film. On the other hand, Patent Document 3 discloses a method in which a hydrophobic substance is attached to the surface of a polyimide and a selective alkali treatment is performed on the exposed portion.

Patent Document 1: Japanese Patent Laid-Open Publication No. 2001-73159

Patent Document 2: Japanese Patent Laid-Open Publication No. 2007-103479

Patent Document 3: Japanese Patent Laid-Open Publication No. 2007-242689

However, as in the invention of Patent Document 2, when a pattern forming method for forming a micro flow path is used, as a mask material for forming a micro flow path groove, it is necessary to select an alkali-resistant material, and selection of a material is not easy. problem. Further, in the method of Patent Document 2, in order to improve the accuracy of the pattern, it is necessary to have a high dimensional accuracy in the processing of the mask material, which is a problem. In particular, if the processing precision of the contact portion between the polyimide substrate and the mask material is low, a gap is formed between the two, and the treatment liquid containing the metal ion solution, the reduction solution, or the like may ooze out there. Therefore, there is a concern that the accuracy of the pattern is lowered or the electrical characteristics of the circuit are adversely affected.

In the invention of Patent Document 3, in order to adhere to the surface of the polyimide, the hydrophobic substance which is not dissolved in the aqueous alkali solution must be subjected to plasma treatment, and the slurry is also subjected to plasma treatment in order to remove the hydrophobic substance. Further, in the invention of Patent Document 3, the mask layer is formed by photolithography before the adhesion of the hydrophobic substance, and the step of peeling off the mask layer is necessary after the adhesion. This means that in order to form a pattern of a hydrophobic substance as a mask, a step of forming another mask layer (resist pattern) and peeling it off is required, and the number of steps is extremely large and complicated, which is a problem.

An object of the present invention is to provide a method of simplifying a conventionally complicated manufacturing process to produce a fine fine pitch and a circuit wiring board having high adhesion reliability between a circuit wiring and an insulating resin layer.

A method of manufacturing a circuit wiring board according to the present invention is a method of manufacturing a circuit wiring board formed by forming a circuit wiring on a polyimide film; and comprising the steps of:

a) a step of impregnating a surface of the polyimine resin precursor resin layer containing the metal ion with an aqueous solution containing a metal ion and drying it, thereby forming a metal ion-containing polyimine precursor resin layer;

b) a step of coating the surface of the metal ion-containing polyimine precursor resin layer with a photoresist layer to form a pattern of the photoresist mask;

c) a surface portion of the aforementioned polyimide intermediate resin layer which is precipitated in a region not covered by the photoresist mask by reducing metal ions in the metal ion-containing polyimide precursor resin layer And forming a metal deposition layer;

d) forming a patterned circuit wiring by electroless plating and/or electroplating on the metal deposition layer; and

e) a step of forming the aforementioned polyimine resin layer by imidization of the above polyimine precursor resin layer by heat treatment.

In the method of manufacturing a circuit board of the present invention, the polyimine precursor resin layer may be formed by treating a layer on the surface side of the polyimide resin layer with an aqueous alkali solution, or may be formed by The polyimine precursor resin solution is applied to a substrate and dried to form a solution.

According to the method of manufacturing a circuit board of the present invention, since the etching step of the seed layer (metal deposition layer) is not required, a fine fine pitch circuit can be formed by a simple step of simplifying the conventional complicated manufacturing steps, so that it is not necessary to have a large Scale equipment investment. Further, since the circuit wiring board having high adhesion reliability of the circuit wiring and the insulating resin layer (polyimine resin layer) can be manufactured, the industrial value is high.

Other objects, features, and advantages of the invention will be apparent from the description.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2 as appropriate. 1 is a flow chart showing the main steps of a method of manufacturing a circuit board according to an embodiment of the present invention; and FIG. 2 is an explanatory view of each step. The circuit wiring board 100 obtained by the manufacturing method of the present invention is formed by forming a circuit wiring 9 on the polyimide film 3b, for example, as shown in Fig. 2(f).

[Formation of Polyimine Precursor Resin Layer]

In the method of manufacturing a circuit wiring board of the present invention, first, as shown in Figs. 1 and 2(a), the polyimide film precursor layer 3 formed on the underlayer 1 is prepared (step S1). The polyimine precursor resin layer 3 can be formed by a method of treating a layer on the surface side of the polyimide layer of the underlayer 1 with an aqueous alkali solution (Method A), or by using any group as the underlayer 1 The solution was obtained by coating a solution of a polyamidene precursor resin on a material and drying it (Method B).

The term "polyimine precursor resin" means a state in which the quinone ring of the polyimide resin is in an open state. The polyimine resin layer has a polyimine resin layer (I) formed by imidating a polyimine precursor resin layer 3, and a polyimine resin layer (I) The polyimine precursor resin layer 3 formed by ring-opening of the quinone imine ring of the polyimide resin is re-imidized to form the polyimide (II) layer. Further, when it is necessary to distinguish the type of the polyimide resin layer, the former is referred to as "polyimine resin layer (I)" and the latter is referred to as "polyimine resin layer (II)". Further, the polyimine imide precursor resin for forming the polyimine resin layer (I) is simply referred to as "precursor". The polyimine precursor resin obtained by the ruthenium imidization of the polyimine resin layer (II) is also simply referred to as "polyproline". Since the precursor or polyamic acid and the polyimide resin are in the relationship between the precursor and the product, the other structure can be understood by explaining one of them. Also, the common part is explained at the same time.

The aspect of the polyimine resin layer is not particularly limited, and may be a film (sheet), or may be laminated to a substrate such as a metal foil, a glass plate, or a resin film. In addition, the term "substrate" as used herein refers to a sheet-like resin, a glass substrate, a ceramic, a metal foil, or the like in which a layer of a polyimide resin layer is laminated. The entire thickness of the polyimide resin layer may be in the range of 3 to 100 μm, preferably in the range of 3 to 50 μm.

Examples of the polyimine resin forming the polyimine resin layer include polyamidimide, polybenzimidazole, polyimine, polyetherimine, and so-called polyimine. A polysiloxane, such as a polyoxyalkyleneimine, has a heat-resistant resin having a quinone imine group in its structure. Further, a commercially available polyimine resin or a polyimide film is also suitably used, and for example, Kapton EN (trade name) manufactured by Toray DuPont Co., Ltd., and Kaneka Chemical Co., Ltd. Picar NPI (trade name), Upi lex (trade name) made by Ube Industries Co., Ltd., etc.

The polyimine resin can be formed by imidating (hardening) the precursor quinone. Here, the precursor also includes a photosensitive group (for example, an ethylenically unsaturated hydrocarbon group) in its molecular skeleton. Details of the oxime imidization are described later.

The insulating resin layer of the circuit wiring board is composed of a polyimide resin layer, and when it is composed of a single layer of a polyimide resin layer, a polyimide having a low thermal expansion property is preferably used. Specifically, the linear thermal expansion coefficient (CTE) is in the range of 1 × 10 ^-6 to 30 × 10 ^-6 (1/K) (1 × 10 ^-6 to 25 × 10 ^-6 (1/K) A low thermal expansion polyimine resin which is preferably in the range of 15 × 10 ^-6 to 25 × 10 ^-6 (1/K). When such a polyimide resin is used as the insulating resin layer, it is advantageous to suppress the warpage of the circuit wiring board. However, it is also possible to use a polyimine resin having a coefficient of thermal expansion higher than the above, and in this case, adhesion to the metal deposition layer can be improved.

The polyimine resin is preferably a polyimine resin having a structural unit represented by the general formula (1).

[Chemical 1]

However, Ar ₁ represents a tetravalent aromatic group represented by formula (2) or formula (3), Ar ₃ represents a divalent aromatic group represented by formula (4) or formula (5), and R ₁ represents an independent carbon. a monovalent hydrocarbon group or alkoxy group having 1 to 6 groups, and X and Y represent an independent single bond or a divalent hydrocarbon group having 1 to 15 carbon atoms, and a divalent value selected from O, S, CO, SO, SO ₂ or CONH The base, n represents an integer of 0 to 4, and q represents the existence molar ratio of the constituent unit, and is a value of 0.1 to 1.0.

[Chemical 2]

The above structural unit may be present in the homopolymer or in the structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may be present as a block copolymer or as a random copolymer. Among the polyimine resins having such structural units, the polyimide polyimide resin which can be preferably used is a non-thermoplastic polyimide resin.

The polyimine resin can be usually produced by reacting a diamine with an acid anhydride. Therefore, a specific example of the polyimide resin can be understood by explaining the diamine and the acid anhydride. In the above formula (1), Ar ₃ can be said to be a residue of a diamine, and Ar ₁ can be said to be a residue of an acid anhydride. The preferred polyiminoimine resin is illustrated by a diamine and an acid anhydride. However, the polyimine resin is not limited to those obtained from the diamines and anhydrides described herein.

As the acid anhydride, preferred are: pyromellitic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylate Acid dianhydride, 4,4'-1 dianhydride. Further, as the acid anhydride, preferred examples are: 2,2',3,3'-, 2,3,3',4'- or 3,3',4,4'-diphenyl ketone four Carboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4' - Diphenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, and the like. Further, as the acid anhydride, preferred examples are: 3,3", 4,4"-, 2,3,3", 4"- or 2,2",3,3"-p-terphenyl Tetracarboxylic dianhydride, 2,2-bis(2,3- or 3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3- or 3,4-dicarboxyphenyl)-methane Anhydride, bis(2,3- or 3,4-dicarboxyphenyl)ruthenium anhydride, 1,1-bis(2,3- or 3,4-dicarboxyphenyl)-ethane dianhydride, and the like.

As other acid anhydrides, for example, 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7 - fluorene tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxylic acid diphenyl)tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 2,3,6 , 7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1, 2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetra Carboxylic dianhydride, 2,3,6,7-(or 1,4,5,8-)tetrachloronaphthalene-1,4,5,8-(or 2,3,6,7-)tetracarboxylic acid Dihydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-fluorene-tetracarboxylic dianhydride, cyclopentane- 1,2,3,4-tetracarboxylic dianhydride, pyridyl -2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4, 4'-bis(2,3-dicarboxyoxyphenoxy)diphenylmethane dianhydride.

As the diamine, preferred examples are: 4,4'-diamine diphenyl ether, 2'-methoxy-4,4'-diaminophenyl anilide, 1,4-bis(4-amine) Phenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2'-bis[4-(4-aminophenoxy)benzene]propane, 2,2'- Dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminobenzoquinone, and the like. Further, as the diamine, preferred are 2,2-bis-[4-(3-aminophenoxy)phenyl]propane and bis[4-(4-aminophenoxy)benzene.碸, bis[4-(3-aminophenoxy)phenyl]anthracene, bis[4-(4-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy) Base)]biphenyl, bis[1-(4-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(4-aminobenzene) Oxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3 -aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)]diphenyl ketone, bis[4-(3-aminophenoxy)]diphenyl ketone, Bis[4,4'-(4-aminophenoxy)]phenylanilide, bis[4,4'-(3-aminophenoxy)]phenylanilide, 9,9-bis[4- (4-Aminophenoxy)phenyl]anthracene, 9,9-bis[4-(3-aminophenoxy)phenyl]anthracene, and the like.

Examples of the other diamines include 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane and 2,2-bis-[4-(3-aminobenzene). Oxy)phenyl]hexafluoropropane, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-2,6-dimethylaniline, 4,4'-methylene Di- 2,6-diethylaniline, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminodiphenylethane , 3,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodi Phenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl fluorene, 3,3'-diaminodiphenyl fluorene, 4,4'-diamine Diphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, benzidine, 3,3'-diaminobiphenyl, 3,3'-Dimethyl-4,4'-diaminobiphenyl,3,3'-dimethoxybenzidine,4,4"-diamino-p-terphenyl,3,3"-diamino -p-terphenyl, m-phenylenediamine, p-phenylenediamine, 2,6-diamine pyridine, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-amino group Phenoxy)benzene, 4,4'-[1,4-phenylenebis(1-methylethylidene)]diphenylamine, 4,4'-[1,3-phenylene bis(1- Methyl ethylene)] bisaniline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-t-butylphenyl)ether, bis(p-β-methyl-δ- Aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5- Diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-amino-t-butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5- Diamine, p-xylene-2,5-diamine, m-xylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5 -diamino-1,3,4- Diazole, piperazine Wait.

The acid anhydride and the diamine may be used alone or in combination of two or more. Further, other acid anhydrides or diamines not contained in the above formula (1) may be used together with the above acid anhydride or diamine. In this case, the other acid anhydrides or diamines not contained in the above formula (1) are preferably used. It is 90 mol% or less, preferably 50 mol% or less. The thermal expansion property, the adhesion property, the glass transition point (Tg), and the like can be controlled by selecting the type of the acid anhydride or the diamine or by using two or more kinds of acid anhydrides or diamines and selecting the respective molar ratios.

The synthesis of the precursor can be synthesized by reacting an approximately equal molar anhydride and a diamine in a solvent. Examples of the solvent to be used include N,N-dimethylacetamide (DMAc), n-methylpyrrolidone, 2-butanone, diglyme, xylene, and the like. Use one type or two or more types together.

As the polyimide resin, a thermoplastic polyimide resin can also be used. The precursor used in the thermoplastic polyimide resin is preferably a precursor having a structural unit represented by the general formula (6). In the formula (6), Ar ₄ represents a divalent aromatic group represented by the formula (7), the formula (8) or the formula (9), and Ar ₅ represents a formula represented by the formula (10) or the formula (11). a valent aromatic group, R ₂ represents an independently monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and V and W represent an independent single bond or a divalent hydrocarbon group having 1 to 15 carbon atoms, and are selected from O, S, and CO. The divalent group in SO ₂ or CONH, m represents an independent integer of 0 to 4, and p represents the existence molar ratio of the constituent unit, and is a value of 0.1 to 1.0.

[Chemical 3]

In the above formula (6), Ar ₄ may be referred to as a residue of a diamine, and Ar ₅ may be referred to as a residue of an acid anhydride. Therefore, a preferred thermoplastic polyimide resin can be illustrated by a diamine and an acid anhydride. . However, the thermoplastic polyimine resin is not limited to those obtained from the diamines and anhydrides described herein.

As a preferred diamine for forming a thermoplastic polyimide resin, for example, 4,4'-diaminodiphenyl ether, 2'-methoxy-4,4'- Diaminobenzidine, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 2,2-bis[4-(4-amino) Phenoxy)phenyl]propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4, 4'-Diaminobenzidine aniline and the like. Further, it is also exemplified in the description of the above polyimine resin. Among these, as a particularly preferred diamine component, it is selected from 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane (DANPG), 2,2-bis[4- (4-Aminophenoxy)phenyl]propane (BAPP), 1,3-bis(3-aminophenoxy)benzene (APB), p-phenylenediamine (p-PDA), 3,4' One or more diamines of diaminodiphenyl ether (DAPE34) and 4,4'-diaminodiphenyl ether (DAPE44) are preferred.

Examples of preferred acid anhydrides suitable for the formation of thermoplastic polyimine resins include pyromellitic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 3,3. ',4,4'-diphenylfluorene tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride. Further, an acid anhydride as exemplified in the above description of the polyimide resin may be mentioned. Among these, as a particularly preferred acid anhydride, it is selected from the group consisting of pyromellitic anhydride (PMDA), 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), and 3,3'. An acid anhydride of at least one of 4,4'-diphenyl ketone tetracarboxylic dianhydride (BTDA) and 3,3',4,4'-diphenyltetracarboxylic dianhydride (DSDA).

It is preferably used in the form of a diamine and an acid anhydride of the thermoplastic polyimine resin, and they may be used alone or in combination of two or more. Further, diamines and acid anhydrides other than the above may be used in combination.

In the precursor of the thermoplastic polyimine resin, the structural unit represented by the formula (6) may be present in the homopolymer or may be present in the structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may be in the form of a block copolymer or may be in the form of a random copolymer. The structural unit represented by the formula (6) is plural, but may be one type or two or more types. Preferably, the structural unit represented by the formula (6) is used as a main component, and more preferably, it contains 60 mol% or more (more preferably 80 mol% or more) of the precursor.

The precursor of the synthesized polyimine resin (including the thermoplastic polyimide resin) can be used as a solution state. It is usually preferably used as a reaction solvent solution, but may be concentrated, diluted or substituted with other organic solvents as necessary. Further, since the polyimine precursor resin is generally excellent in solvent solubility, it can be advantageously used.

The method for forming the precursor layer is not particularly limited. For example, the precursor solution may be applied to the underlayer 1 (for example, any substrate) and then dried to form. The coating method is not particularly limited, and it can be applied by, for example, a coater such as a comma type, a mold type, a knife type, or a lip coater. It is then dried to form a precursor layer.

The above precursor layer can be used directly after drying. In the drying, the temperature is controlled in such a manner that the hydrazine imidization is not completed by the dehydration ring closure of the polyimine precursor resin. The method for drying is not particularly limited. For example, it can be dried in a temperature range of from 60 to 200 ° C for a period of from 1 to 60 minutes, preferably from 60 to 150 ° C. Dry under conditions. It is necessary to leave it in the state of the precursor in order to impregnate it with an aqueous solution containing metal ions. After the drying, the precursor layer may be partially imidized by hydrazine, and the imidization ratio is preferably 50% or less (more preferably 20% or less), and the structure of the precursor is 50. More than % is better. Further, the imidization ratio of the precursor can be determined by a Fourier transform infrared spectrophotometer (commercial product: FT/IR620, Japan Spectrophotometry) to determine the infrared absorption spectrum of the polyimide film by a transmission method. Using a benzene ring carbon-hydrogen bond of 1,000 cm ^-1 as a reference, the absorbance from the quinone imine group of 1,710 cm ^-1 was calculated.

In the polyimine resin layer (II), the precursor can be dried to be imidized into a polyimine resin layer (I), and it can be produced as an intermediate. The method of drying and hydrazine imidization is not particularly limited, and for example, heat treatment may be employed in which the precursor layer is heated at a temperature of 80 to 400 ° C for 1 to 60 minutes. Since the precursor is subjected to dehydration ring closure by performing such heat treatment, the polyimide layer (I) can be formed on the substrate. The polyimine resin layer (I) formed on the substrate in this manner can be used as an intermediate for producing the polyimide layer (II), or can be used as a film or a sheet in a peeling manner. . The polyimine resin layer (I) as an intermediate thus formed is treated with an aqueous alkali solution to form a polyamic acid layer, and the formed polylysine layer is impregnated with a solution containing a metal ion. The treatment method of the aqueous alkali solution will be described later.

The polyimide layer may be formed of only a single layer or a plurality of layers. In the case where the polyimine resin layer is used as a plurality of layers, other precursors may be sequentially applied to the precursor layers of different constituent components. In the case where the precursor layer is composed of three or more layers, the precursor having the same structure may be used twice or more. A layer having a simple layer structure or a single layer, especially a single layer, is preferable because it is industrially advantageous. Further, the thickness of the precursor layer (after drying) is preferably in the range of 3 to 100 μm, preferably in the range of 3 to 50 μm. In the method of coating the precursor (Method B), the thickness of the precursor layer can be freely adjusted as compared with the alkali treatment method (Method A). Therefore, the precursor layer is formed to a thickness of 3 μm or more by the method B, and the impregnation amount of the metal ions can be sufficiently ensured in the metal ion impregnation step (described later) to be described later. As a result, the metal deposition layer 7 in the metal deposition layer forming step (described later) can be formed into a conductive film shape.

In the case where the precursor layer is formed as a plurality of layers, it is preferable that the polyimide layer of the metal deposition layer 7 (described later) is formed so that the precursor layer is formed into a thermoplastic polyimide layer. The adhesion to the metal deposition layer 7 can be improved by using a thermoplastic polyimine resin. Such a thermoplastic polyimine resin preferably has a glass transition temperature (Tg) of 350 ° C or less, more preferably 200 to 320 ° C.

As a polyimide resin precursor resin solution, a commercially available product can also be suitably used, for example, U-Varnish-a non-thermoplastic polyimine precursor resin varnish (varnish) manufactured by Ube Industries, Ltd. A (trade name), the same as U-Varnish-S (trade name), the new thermoplastic iron polyimide precursor resin varnish SPI-200N (trade name), the same SPI-300N (commodity) Name), SPI-1000G (trade name), Toraynish #3000 (trade name) made by Toray (share).

Next, in the case where the underlayer 1 is a polyimine resin layer, the method A in which the surface is treated with an aqueous alkali solution to form an alkali treatment layer (polyamic acid layer) will be described. As the aqueous alkali solution, an aqueous alkali solution of sodium hydroxide or potassium hydroxide in a concentration range of 0.5 to 50% by weight and a liquid temperature of 5 to 80 ° C is preferably used. As the aqueous alkali solution, for example, a dipping method, a spray method, a brush coating, or the like can be used. For example, in the case of using the dipping method, it is effective to treat for 10 seconds to 60 minutes. Preferably, the surface of the polyimide resin layer is treated for 30 seconds to 10 minutes with an aqueous alkali solution having a concentration in the range of 1 to 30% by weight and a liquid temperature of 25 to 60 °C. The processing conditions can be appropriately changed depending on the structure of the polyimide layer. Generally, in the case where the concentration of the aqueous alkali solution is relatively thin, the surface treatment time of the polyimide resin layer must be long. Further, if the liquid temperature of the aqueous alkali solution is high, the treatment time can be shortened.

When treated with an aqueous alkali solution, the aqueous alkali solution is impregnated from the surface side of the polyimide film layer to modify the polyimide film layer. By the modification reaction by the alkali treatment, it is considered that the main is the hydrolysis of the quinone imine bond. The thickness of the alkali-treated layer formed by the alkali treatment is preferably in the range of 1/200 to 1/2 of the thickness of the polyimide layer, and preferably in the range of 1/100 to 1/5. Further, for other considerations, the thickness of the alkali-treated layer is preferably in the range of 0.005 to 3.0 μm, more preferably in the range of 0.05 to 2.0 μm, and even more preferably in the range of 0.1 to 1.0 μm. It is advantageous to form the metal deposition layer 7 by making it in this thickness range. When the thickness of the alkali-treated layer is less than the above lower limit (0.005 μm), the metal ions deposited on the metal are not sufficiently impregnated, so that it is difficult to sufficiently exhibit the sufficient bonding strength between the polyimide and the metal deposition layer 7. On the other hand, in the treatment of the polyimine resin layer by the aqueous alkali solution, at the same time as the ring opening of the quinone ring of the polyimide resin, the outermost portion of the polyimide layer is produced. Since it tends to dissolve, it is difficult to exceed the above upper limit (3.0 μm).

In the case where the polyimine resin layer is a polyimide film, both sides may be subjected to alkali treatment at the same time to be modified. The polyiminoimine resin layer composed of the above-mentioned low thermal expansion polyimine resin is particularly effective in alkali treatment, and is preferred. Since the low thermal expansion polyimine resin has good wettability with an aqueous alkali solution, the ring-opening reaction of the ruthenium ring treated by alkali is liable to occur.

In the alkali-treated layer formed by the alkali treatment, a salt formed by a carboxyl group at the terminal of the alkali metal and the polyimide resin may be formed by the aqueous alkali solution. The alkali metal salt of the carboxyl group can be substituted with the metal ion salt by the metal ion impregnation treatment in the metal ion impregnation step described later, so that there is no problem in the presence of the metal ion salt before the metal ion impregnation step. Further, the surface layer of the polyimide resin which has been changed to be basic may be neutralized with an aqueous acid solution. As the aqueous acid solution, any aqueous solution can be used as long as it is acidic, and particularly preferably an aqueous hydrochloric acid solution or an aqueous sulfuric acid solution. Further, the concentration of the aqueous acid solution is preferably in the range of, for example, 0.5 to 50% by weight, more preferably 0.5 to 5% by weight. The pH of the aqueous acid solution is preferably 2 or less. After washing with an aqueous acid solution, it may be washed with water, dried, and supplied to a second metal ion impregnation step.

[Step a: Metal ion impregnation step]

Then, as shown in FIG. 1 and FIG. 2(b), the polyimine precursor resin layer 3 is impregnated with an aqueous solution containing metal ions (hereinafter also referred to as "metal ion solution", and then dried. The polyimine precursor resin layer containing metal ions (hereinafter also referred to as "metal ion-containing layer 3a") is formed (step S2). Here, the polyimine precursor resin layer 3 is formed by coating the above polyimide precursor solution or alkali treatment of a polyimide resin. By this impregnation treatment, the carboxyl group present in the polyimine precursor resin layer 3 is converted into a metal salt of a carboxyl group.

As the metal ion, an ion having a metal species having an oxidation-reduction potential higher than that of the reducing agent used in the reduction step can be used, and is not particularly limited. Examples of the metal compound containing these metal species include metal species such as Cu, Ni, Pd, Ag, Au, Pt, Sn, Fe, Co, Cr, Rh, and Ru. As the metal compound, a salt of the above metal, an organic carbonyl complex or the like can be used. The salt of the metal may, for example, be a hydrochloride, a sulfate, an acetate, an oxalate or a citrate. As the metal salt, those in which the aforementioned metal is Cu, Ni, or Pd can be preferably used. In addition, examples of the organic carbonyl compound which can form an organic carbonyl-based complex with the above-mentioned metal include β-diketones such as acetamidineacetone, benzamidineacetone, and benzhydrylmethane, and ethyl acetate. Β-oxocarboxylic acid esters and the like.

Preferable specific examples of the metal compound include Ni(CH ₃ COO) ₂ , Cu(CH ₃ COO) ₂ , Pd(CH ₃ COO) ₂ , NiSO ₄ , CuSO ₄ , PdSO ₄ , NiCO ₃ , CuCO _{3 .} , PdCO ₃ , NiCl ₂ , CuCl ₂ , PdCl ₂ , NiBr ₂ , CuBr ₂ , PdBr ₂ , Ni(NO ₃ ) ₂ , NiC ₂ O ₄ , Ni(H ₂ PO ₂ ) ₂ , Cu(NH ₄ ) ₂ Cl ₄ , CuI, Cu(NO ₃ ) ₂ , Pd(NO ₃ ) ₂ , Ni(CH ₃ COCH ₂ COCH ₃ ) ₂ , Cu(CH ₃ COCH ₂ COCH ₃ ) ₂ , Pd(CH ₃ COCH ₂ COCH ₃ ) ₂ Wait.

The metal ion solution used in the impregnation step is preferably in the range of 30 to 300 mM containing the metal compound, and more preferably in the range of 50 to 100 mM. If the concentration of the metal compound is less than 30 mM, the time required to impregnate the metal ion into the polyimine precursor resin layer 3 (or the polyamic acid layer) may be too long, so it is not preferable, if it exceeds 300 mM, the poly The surface of the quinone imine resin layer 3 (or polyamic acid layer) may be corroded (dissolved).

The metal ion solution may contain, for example, a component such as a buffer for the purpose of pH adjustment, in addition to the metal compound.

The impregnation method is not particularly limited as long as it can contact the metal ion solution with the surface of the polyimine precursor resin layer 3 (or polyamic acid layer), and a known method can be used. For example, a dipping method, a spray method, a brush coating method, a printing method, or the like can be used. The temperature of the impregnation may be from 0 to 100 ° C, preferably from about 20 to 40 ° C. Further, the impregnation time is preferably from 1 minute to 5 hours, more preferably from 5 minutes to 2 hours, in the case of using the dipping method. When the immersion time is shorter than 1 minute, the impregnation of the metal ion with the polyimide intermediate precursor resin layer 3 (or the polyamic acid layer) may be insufficient, so that the anchoring effect described later cannot be obtained. On the other hand, when the immersion time exceeds 5 hours, the degree of impregnation of the metal ion to the polyimide intermediate resin layer 3 (or the polyamic acid layer) tends to be constant.

Dry after impregnation. The drying method is not particularly limited and may be, for example, natural drying, spray drying with an air gun, or drying with an oven. The drying condition is preferably from 5 to 150 ° C for 5 seconds to 60 minutes, preferably from 25 to 150 ° C for 10 seconds to 30 minutes, and more preferably from 30 to 120 ° C for 1 to 10 minutes.

[Step b: photoresist pattern forming step]

Then, as shown in FIG. 1 and FIG. 2(c), a photoresist pattern 5 is formed on the surface of the metal ion-containing layer 3a as a mask to form a photoresist pattern (step S3). A well-known method can be used for formation of a photoresist pattern, and it is not specifically limited. For example, a photolithography technique in which a photosensitive photoresist is laminated or applied on the surface of the metal ion-containing layer 3a to form a photoresist layer 5, which is exposed, developed, and cured to form a photoresist pattern can be used.

[Step c: Metal precipitation layer forming step]

Next, in the method of manufacturing the circuit board of the present embodiment, as shown in FIGS. 1 and 2(d), the metal in the metal ion-containing layer 3a is exposed in the exposed region not blocked by the photoresist layer 5. The ions are reduced to form a metal deposition layer 7 (step S4). The method of reduction treatment is particularly advantageous by using a wet reduction method. The wet reduction method is a method of reducing metal ions in an exposed region not blocked by the photoresist layer 5 by immersing the metal ion-containing layer 3a in a solution (reducing agent solution) containing a reducing agent. In the wet reduction method, metal ions existing in the inside of the metal ion-containing layer 3a (for example, a deep portion at a position deeper than the surface portion or a coating portion directly under the photoresist layer 5) are reduced at the place where they are The precipitation of the metal form can be suppressed, and the metal layer can be preferentially deposited in the surface layer portion of the metal ion-containing layer 3a, which is an effective method. Further, in the wet reduction method, unevenness in precipitation of metal is small, and a uniform metal deposition layer 7 can be formed in a short time.

Moreover, the polyimine precursor resin layer 3 obtained by the method B (that is, the method of coating the solution of the polyimine precursor resin) can be easily impregnated with metal ions because the thickness can be easily sufficiently ensured. The amount of metal ions in the layer 3a (that is, the content of metal ions in the resin layer) can be greatly increased. As a result, the metal deposition layer 7 obtained in the metal deposition layer forming step (step S4) can be formed into a film shape, so that the electroless plating step to be described later can be omitted. Since the electroless plating has a problem of management of the plating solution and the disposal of the waste liquid, it is possible to form a circuit wiring excellent in adhesion to the substrate without using electroless plating, and industrially. The value is very large. Based on such considerations, it is particularly preferred to use a combination of the polyimine precursor resin layer 3 formed by the method B and the wet reduction method in the metal deposition layer formation step.

As the reducing agent, for example, a boron compound such as sodium borohydride, potassium borohydride or dimethylamine borane is preferable. These boron compounds can be used as a solution (reducing agent solution) such as sodium hypophosphite, formaldehyde, hydrazine or the like. The concentration of the boron compound in the reducing agent solution is preferably in the range of, for example, 0.005 to 0.5 mol/L, more preferably in the range of 0.01 to 0.1 mol/L. If the concentration of the boron compound in the reducing agent solution is less than 0.005 mol/L, the reduction of the metal ion contained in the metal ion-containing layer 3a may be insufficient, and if it exceeds 0.5 mol/L, due to the action of the boron compound, the polyfluorene The amine precursor resin will dissolve.

Further, in the wet reduction treatment, the region not blocked by the photoresist layer 5 is immersed in a reducing agent solution at a temperature of 10 to 90 ° C (preferably in the range of 50 to 70 ° C) for 20 seconds to ～ 30 minutes (30 seconds to 10 minutes, preferably 1 minute to 5 minutes). By impregnation, the metal ions in the metal ion-containing layer 3a are reduced by the action of the reducing agent, and the metal is precipitated into particles in the surface layer portion of the metal ion-containing layer 3a. At the end point of the reduction, in the polyimine precursor resin other than the exposed surface layer portion of the metal ion-containing layer 3a (for example, the deep portion or the coating portion directly under the photoresist layer 5), almost no metal ions exist. status. The reason for this is that the metal ions in the metal ion-containing layer 3a are moved to the surface layer portion of the unmasked region of the metal ion-containing layer 3a while being maintained in a uniform concentration distribution, and the metal ions in the metal layer-containing layer 3a are moved. Metal ions are reduced in the vicinity of the surface layer portion to precipitate a metal. In the polyimine precursor resin layer 3, the metal ions are hardly left in the polyimine precursor resin layer 3, and even if metal ions remain in the polyimide precursor resin layer 3, they can be treated by an acid described later. The residual metal ions can be removed. The determination of the end point of the reduction, for example, by measuring the cross section of the metal ion-containing layer 3a (or the polyimine precursor resin layer 3) by an energy dispersive X-ray (EDX) analyzer, reading the atom of the residual metal ion Confirmed by weight %.

In the present embodiment, in the metal deposition layer forming step, the metal deposition layer 7 which is the seed layer of the circuit wiring 9 is formed only in the portion where the photoresist layer 5 which is not patterned is covered, and is in the lower portion of the photoresist layer 5 Not formed, as a result, there is no need to use a flash etching step to remove the seed layer, and it is possible to reduce the number of steps and improve the reliability of the circuit wiring substrate.

[Step d: Circuit wiring forming step]

Next, as shown in FIG. 1 and FIG. 2(e), the circuit wiring 9 having a pattern is formed on the metal deposition layer 7 by electroless plating and/or plating (step S5). The electroless plating is performed by immersing the polyimine precursor resin layer 3 on which the metal deposition layer 7 is formed in an electroless plating solution (electroless plating step). An electroless plating layer can be formed by this electroless plating. This electroless plating layer serves as a core for subsequent plating.

As an electroless plating solution used in the electroless plating step, the influence of the influence on the polyimide polyimide precursor resin is selected from a neutral to weakly acidic hypophosphorous acid nickel plating solution or a boron system. Nickel plating solution is preferred. For example, Top-Nikoro N (trade name; manufactured by Okuno Pharmaceutical Co., Ltd.) may be mentioned as a commercially available product of the nickel phosphite-based nickel plating solution. In addition, as a commercial item of the boron-based nickel plating solution, for example, Top-Chemialloy B-1 (trade name; Okuno Pharmaceutical Co., Ltd.), Top-Chemialloy 66 (trade name; Okuno Pharmaceutical Industry) (share) system). Further, the pH of the electroless plating solution is preferably adjusted to a neutral to weak acidity of 4 to 7. In this case, for example, an inorganic acid such as sulfuric acid, hydrochloric acid, nitric acid, boric acid or carbonic acid, an organic acid such as acetic acid, glycolic acid, citric acid or tartaric acid may be used, or boric acid, carbonic acid, acetic acid, citric acid or the like may be combined. The weak acid and its alkali salt provide a buffering effect. The temperature of the electroless plating treatment is preferably in the range of 80 to 95 ° C, more preferably in the range of 85 to 90 ° C. Further, the treatment time of the electroless plating step can be set to 20 seconds to 10 minutes, preferably 30 seconds to 5 minutes, and more preferably 1 minute to 3 minutes.

Then, electroplating is performed by electroplating with an electroless plating layer as a core (electroplating step). A plating layer is formed by electroplating to cover the electroless plating layer. Electroplating is carried out in a plating solution containing a composition of, for example, sulfuric acid, copper sulfate, hydrochloric acid, and a glossing agent (for example, Machusbeck (trade name) manufactured by Mademan Co., Ltd., which is a commercially available product). The plating layer is used as a cathode, and a metal such as Cu is used as an anode. The current density in the electroplating is preferably in the range of, for example, 0.2 to 3.5 A/dm ² . Further, as the anode for electroplating, for example, a metal such as Ni or Co other than Cu may be used.

Further, as described above, the method of forming the polyimine precursor resin layer 3 and the reduction method in the step of forming the metal deposition layer can be optimized, and the electroless plating step can be omitted.

After the circuit wiring 9 having the pattern is formed, the photoresist layer 5 which becomes unnecessary is peeled off. The method of peeling off the photoresist layer 5 is not limited, and is preferably, for example, a method of immersing in an alkali solution such as a sodium hydroxide aqueous solution having a concentration of 1 to 4% by weight or a potassium hydroxide aqueous solution. In addition, when the photoresist layer 5 is removed after the imidization, the action of the alkali solution for resist stripping or the like may cause adverse effects such as deterioration of the polyimide resin, and the photoresist layer 5 may be affected. The stripping is preferably carried out prior to the imidization of the polyamidene precursor resin of the substep. However, in the case where the photoresist layer 5 is formed as a part of the inter-circuit insulating layer of the circuit wiring 9, the peeling of the photoresist layer 5 is not necessary, and is not limited thereto.

Here, the removal of metal ions in the polyimide precursor resin layer 3 will be described. In the wet reduction treatment, for example, in the case of using a metal salt such as sodium borohydride, potassium borohydride or dimethylamine boron, or in the peeling of the photoresist layer 5, sodium hydroxide or potassium hydroxide is used. In the case of a metal salt such as the above, metal ions derived from the above metal salt may be present in the polyimine precursor resin layer 3, so that it is preferably removed. The removal of the metal ions can be carried out by immersing in an aqueous acid solution. In this case, an acid suitable for dissociation of the metal ion which is coordinated with the carboxyl group of the poly-proline is selected to select a stronger acid than the polyamine ( The acid dissociation constant pKa is preferably 3.5 or less. Further, it is preferred to select an acid which does not dissolve the metal precipitated by precipitation. Specific examples of such an acid include citric acid (pKa = 2.87) and oxalic acid (pKa = 1.04). Further, a strong acid such as hydrochloric acid, nitric acid or sulfuric acid dissolves the metal deposition layer 7, and acetic acid (pKa = 4.56) has a low acid strength and is difficult to remove metal ions, which is not preferable. The conditions for the immersion treatment for removing metal ions are preferably in the range of 1 to 15% by weight (preferably in the range of 5 to 10% by weight) and the temperature of 20 to 50 °C. The aqueous solution of the acid is immersed in the range of 2 to 10 minutes. By performing such an acid treatment, the metal ions remaining in the polyimine precursor resin layer 3 can be simultaneously removed after the reduction or after the photoresist layer is peeled off. Further, the method of removing metal ions is disclosed, for example, in "The 17th Microelectronics Symposium Preparation Draft", September 2007, pages 179 to 182.

[Step e: oxime imidization step]

Next, as shown in FIG. 1 and FIG. 2(f), the polyimine precursor resin layer 3 is imidized by heat treatment to form a polyimide resin layer 3b (step S6). The method for the imidization of hydrazine is not particularly limited, and it is preferably, for example, a heat treatment at a temperature in the range of from 80 to 400 ° C for a period of from 1 to 60 minutes. In order to suppress oxidation of the circuit wiring 9 of the metal layer formed by reduction and plating, heat treatment in a low oxygen atmosphere is preferable, specifically, in an inert gas atmosphere such as nitrogen or a rare gas, hydrogen, or the like. It is preferred to carry out the reducing gas atmosphere or in a vacuum. Further, the imidization step of the step S6 is preferably carried out after the circuit wiring forming step of the step S5, but it is not problematic until the step of the step S5.

By the steps S1 to S6 described above, the circuit wiring substrate 100 in which the circuit wiring 9 having excellent adhesion can be formed on the insulating resin layer having the underlayer 1 and the polyimide layer 3b.

According to the method of manufacturing the circuit wiring board of the present embodiment, the circuit wiring 9 having excellent adhesion can be formed on the insulating resin layer having the polyimide layer 3 by the steps S1 to S6 described above. The circuit wiring substrate 100. This method is a simple method in which the number of steps is small and does not require special equipment and devices, and it does not need to be used to remove the etching step of the metal deposition layer, so the industrial use value is very large.

In the following, the present invention is specifically described by way of examples, but the present invention is not limited by the examples. Further, in the examples of the present invention, various measurements and evaluations are based on the following unless otherwise specified. Further, the abbreviations used in the present embodiment are the same as described above.

[Evaluation of adhesion]

In the evaluation of the adhesion, a test piece for measurement of a circuit wiring of 3 mm width was produced, and the strength was measured by measuring the tensile strength in the 90° direction at room temperature by using a Strograph M1 (manufactured by Toyo Seiki Seisakusho Co., Ltd.). In addition, the evaluation of the adhesion is judged as "practicality" when the tensile strength is 0.5 kN/m or more and less than 1.0 kN/m, and it is judged as "excellent" when it is 1.0 kN/m or more. "."

[Determination of linear thermal expansion coefficient]

The linear thermal expansion coefficient was measured by using a Thermo-Mechanical Analyzer (manufactured by Seiko Instruments Co., Ltd.), and the sample was heated to 250 ° C, and then kept at this temperature for 10 minutes, and then cooled at a rate of 5 ° C / minute. The evaluation was performed by finding the average linear thermal expansion coefficient (CTE) from 240 ° C to 100 ° C.

[Measurement of glass transition temperature]

The glass transition temperature was measured by using a viscoelastic analyzer (RSA-II manufactured by Rheometric Science FE Co., Ltd.) from a room temperature of 10 mm/min while applying a vibration of 1 Hz to a temperature of 10 ° C/min. At 400 ° C, the maximum value of the loss tangent (Tan δ) is obtained.

[Measurement of thickness of treated layer treated with aqueous alkali solution]

The cross section of the sample was observed with a scanning electron microscope (manufactured by Hitachi Hitechnologies Co., Ltd.) to confirm the thickness of the treated layer treated with the aqueous alkali solution.

[Measurement of sheet resistance of metal layer]

The sheet resistance of the metal layer was measured by a resistance measuring instrument (MCP-T610 manufactured by Mitsubishi Chemical Corporation) in accordance with the method of JIS K 7194. Further, the case where the measured value of the sheet resistance of the metal layer exceeds 50 Ω/□ (ohm/square) is evaluated as the level of “hard plating”. In addition, the case of 50 Ω/□ or less is evaluated as “electroplatable”. In addition, when it is 30 Ω / □ or less, it is evaluated that the metal layer is "excellent" as a conductive film.

[Method of evaluation of anti-warping]

The conductor layer was formed into a resin film by a cutting machine to prepare a test piece having a size of 10 cm × 10 cm, and the height of the highest portion from the table top when the test piece was placed on the table was measured by a vernier scale (nonius). . The amount of the anti-warpage of the resin film formed by using this height as the conductor layer was evaluated as "no anti-warping" when the amount of anti-warpage was less than 2 mm.

[Production Example 1]

20.7 g of 2'-methoxy-4,4'-diaminobenzidine (0.08 mol) was dissolved in 343 g of DMAc in a 500 ml separable flask with stirring. Then, 28.5 g of PMDA (0.13 mol) and 10.3 g of DAPE 44 (0.05 mol) were added to the solution under a nitrogen stream. Then, stirring was continued for about 3 hours to carry out a polymerization reaction, thereby obtaining a viscous polyimide intermediate resin solution S ₁ .

The obtained polyimine precursor resin solution S _{1 was} coated on a stainless steel substrate, dried at 130 ° C for 5 minutes, and heated to 360 ° C for 15 minutes to complete the oxime imidization to obtain a laminate on a stainless steel substrate. Polyimine film. The polyimide film was peeled off from a stainless steel substrate to obtain a polyimide film S ₂ having a thickness of 25 μm. The polyimine film S _{2 has} a linear thermal expansion coefficient of 14.6 × 10 - ⁶ (1/K) (the obtained polyimide film is a non-thermoplastic polyimide resin).

[Production Example 2]

29.5 g of APB (0.1 mol) was dissolved in 367 g of DMAc in a 500 ml separable flask with stirring. Then, 9.1 g of PMDA (0.04 mol) and 20.2 g of BTDA (0.06 mol) were added to the solution under a nitrogen stream. Then, stirring was continued for about 3 hours to carry out a polymerization reaction, thereby obtaining a viscous polyimine precursor resin solution T ₁ .

The obtained polyimine precursor resin solution T _{1 was} applied onto a stainless steel substrate, dried at 130 ° C for 5 minutes, and the coated film was heated to 360 ° C for 15 minutes to complete the oxime imidization, and the substrate was removed to obtain a thickness. 12 μm polyimine film T ₂ . The obtained polyimide film T _{2 had} a glass transition temperature of 218 ° C and a linear thermal expansion coefficient of 54.5 × 10 ^-6 (1/K).

[Production Example 3]

A test piece of an alkali-free glass (AN-100 manufactured by Asahi Glass Co., Ltd.) was 12.5 cm × 12.5 cm (0.7 mm thick), and treated with a 5N aqueous sodium hydroxide solution at 50 ° C for 5 minutes. Then, the glass substrate of the test piece was washed with pure water, and after drying, it was immersed in an aqueous solution of 1% by weight of 3-aminopropyltrimethoxydecane (hereinafter abbreviated as "γ-APS"). This glass substrate was taken out from the γ-APS aqueous solution, dried, and heated at 150 ° C for 5 minutes to obtain a glass substrate G.

[Example 1]

A polyimide film (manufactured by Toray DuPont Co., Ltd., trade name: Kapton EN, 100 mm × 100 mm × 25 μm thick, linear thermal expansion coefficient (CTE) 16 × 10 ^-6 / K) was immersed in 5 N at 50 ° C 10 minutes in aqueous potassium hydroxide solution. Then, the impregnated polyimide film was sufficiently washed with ion-exchanged water, immersed in a 1% by weight aqueous hydrochloric acid solution (25 ° C) for 30 seconds, and further washed with ion-exchanged water to be dried by a compressed air. A surface treated polyimine film a1 was obtained. The thickness of the alkali-treated layer on one side of the surface-treated polyimide film a1 was 1.4 μm.

Then, the surface-treated polyimine film a1 was immersed in a 100 mM aqueous nickel acetate solution (25 ° C) for 10 minutes, and the alkali-treated layer was impregnated with nickel ions to form an impregnation layer (metal ion-containing layer). Then, the surface of the impregnated layer was laminated with a dry film photoresist (manufactured by Asahi Kasei Co., Ltd., trade name: Sunphoto AQ, 10 μm thickness) at a temperature of 110 ° C, and exposed to ultraviolet light through a light mask to give 0.5% by weight of carbonic acid. The sodium aqueous solution was developed to form a photoresist pattern of 50 μm {wiring width / wiring interval (L/S) = 20 μm / 30 μm}, and a film b1 on which a photoresist pattern was formed was obtained.

The film b1 on which the photoresist pattern was formed was immersed in a 10 mM sodium borohydride aqueous solution (30 ° C) for 2 minutes to form a nickel deposition layer on the surface of the impregnation layer not covered by the photoresist layer to obtain a nickel deposition film c1. The sheet resistance of this nickel-precipitated film c1 was measured and found to be 1500 Ω/□. Then, the nickel was deposited on the film c1, and immersed in an electroless nickel plating bath (manufactured by Okuno Pharmaceutical Co., Ltd., trade name: Top-Nikoron TOM-S) at a temperature of 80 ° C for 30 seconds, thereby forming copper. Nickel layer of electroplated substrate. Here, the sheet resistance of the nickel layer formed by electroless nickel plating was 15 Ω/□. Further, the formed nickel layer was plated at a current density of 3.5 A/dm ² in a copper plating bath to form a copper wiring having a copper film thickness of 10 μm, thereby obtaining a film d1 in which a copper wiring was formed.

The obtained film d1 on which the copper wiring was formed was immersed in a 2% by weight aqueous sodium hydroxide solution (25 ° C) for 3 minutes, and the photoresist pattern was peeled off, and then immersed in a 10% by weight aqueous solution of oxalic acid (25 ° C). In minutes, the residual metal is removed.

The film d1 on which the copper wiring was formed was washed with ion-exchanged water, and then heated to 300 ° C in a nitrogen atmosphere, and the polyimine precursor resin ruthenium was imidized at the same temperature for 5 minutes. Then, it was cooled to room temperature under a nitrogen atmosphere to obtain a polyimide film e1 on which a copper wiring was formed. The polyimide film of the polyimine resin film formed with the copper wiring was not warped, and the tensile strength of the copper wiring was 0.7 kN/m, and the adhesion was not problematic.

[Embodiment 2]

The polyimine precursor resin solution S ₁ was applied onto the stainless steel substrate in such a manner that the thickness after the imidization was 25 μm, and dried at 130 ° C for 20 minutes to obtain a polyimine precursor resin layer a2. .

A polyimine formed with a photoresist pattern was obtained in the same manner as in Example 1 except that the surface-treated polyimine film a1 in Example 1 was changed to the polyimine precursor resin layer a2. The precursor resin layer b2, the nickel precipitation precursor resin layer c2, the copper wiring wiring precursor resin layer d2, and the copper wiring-forming polyimide resin layer e2. Moreover, the sheet resistance of the nickel deposition layer in the nickel precipitation precursor resin layer c2 is 25 Ω/□, which is particularly excellent as a conductive film. The polyimine resin layer e2 on which the copper wiring was formed was peeled off from the stainless steel substrate to obtain a film e2' in which a copper wiring was formed. The obtained film e2' in which the copper wiring was formed was not warped, and the tensile strength of the copper wiring was 0.7 kN/m, and the adhesion was not problematic.

[Example 3]

The polyimine precursor resin solution T ₁ was applied to the glass substrate G so that the thickness of the oxime iodide was 5 μm, and dried at 130 ° C for 20 minutes to obtain a polyimide film of the polyimide precursor. A3.

A polyimine formed with a photoresist pattern was obtained in the same manner as in Example 1 except that the surface-treated polyimine film a1 in Example 1 was changed to the polyimine precursor resin layer a3. The precursor resin layer b3, the nickel precipitation precursor resin layer c3, the copper wiring front precursor resin layer d3, and the copper wiring-forming polyimine resin layer e3. Moreover, the sheet resistance of the nickel deposition layer in the nickel precipitation precursor resin layer c3 is 50 Ω/□, which is a level at which direct electroplating can be omitted by omitting electroless plating. The polyimine resin layer e3 having the copper wiring formed thereon was obtained, and the tensile strength of the copper wiring was 1.0 kN/m, which was excellent in adhesion.

[Example 4]

The polyamidene precursor resin solution S ₁ was applied to a stainless steel substrate so that the thickness after the imidization was 25 μm, and dried at 130 ° C for 20 minutes. Further, the polyimine precursor resin solution T ₁ was applied so as to have a thickness of 1.4 μm after the imidization, and dried at 130 ° C for 20 minutes to obtain a polyimide intermediate resin layer a4.

A polyimine formed with a photoresist pattern was obtained in the same manner as in Example 1 except that the surface-treated polyimine film a1 in Example 1 was changed to the polyimine precursor resin layer a4. The precursor resin layer b4, the nickel precipitation precursor resin layer c4, the copper wiring precursor resin layer d4, and the copper wiring-formed polyimide resin layer e4. In addition, the sheet resistance of the nickel deposition layer in the nickel precipitation precursor resin layer c4 is 20 Ω/□, which is particularly excellent as a conductive film. The obtained polyimide film layer e4 having the copper wiring formed thereon is peeled off from the stainless steel substrate to obtain a film e4' having a copper wiring formed thereon. The obtained film e4' in which the copper wiring was formed was not warped, and the tensile strength of the copper wiring was 1.1 kN/m, which was excellent in adhesion.

The test summary of the above Examples 1 to 4 and the test results are shown in Table 1.

As can be seen from Table 1, it was found that the copper wiring resin layer was formed as the circuit wiring substrate manufactured by the methods of Examples 1 to 4, and the tensile strength of either of them was 0.7 kN/m or more, even if it was flexible. The use of printed wiring boards, etc., also has practical and problem-free adhesion.

In particular, Example 3 and implementation of forming a surface precursor resin layer using a polyimide polyimide precursor solution T ₁ and a thermoplastic polyimide resin having a glass transition temperature of 350 ° C or less (Tg = 218 ° C) In Example 4, very excellent adhesion was exhibited. The reason for this is that the surface layer is formed of the precursor of the thermoplastic polyimide resin, and the metal nickel particles precipitated in the metal deposition layer forming step are likely to be embedded in the precursor layer.

Further, a low thermal expansion polyimine resin having a coefficient of thermal expansion coefficient of 1 × 10 ^-6 to 30 × 10 ^-6 (1/K) [CTE = 14.6 × 10 ^-6 (1/K)] In Example 4 in which the above-mentioned thermoplastic polyimide resin was laminated to form a multilayer structure, it was revealed that the thermoplastic polyimide polyimide resin was disposed in the layer adjacent to the nickel deposition layer, and therefore, for the same reason as described above. Very excellent adhesion is obtained, and the back-up of the substrate can be effectively suppressed by the laminated structure with the low thermal expansion polyimide resin.

Further, in the examples 2 to 4 in which the method B (the method of coating the polyimine precursor resin solution) was used as the method for preparing the polyimide precursor resin layer, the precipitation of nickel after the reduction treatment was carried out. The sheet resistance of the layer is 50 [Ω/□] or less, and the plating treatment can be performed directly without performing the electroless plating step. The reason for this is presumed to be that by forming a polythenimine precursor resin layer having a sufficient thickness, the precursor layer can be rich in nickel ion impregnation amount, and the nickel precipitation layer can be formed into a dense film.

The present invention is not limited to the embodiments described above, and various modifications may be made without departing from the spirit and scope of the invention.

(industrial availability)

The method of the present invention can be applied to the manufacture of a circuit wiring board using a printed wiring board or the like of various electronic parts.

1. . . Bottom layer

3. . . Polyimine precursor resin layer

3a. . . Metal ion containing layer

3b. . . Polyimine resin layer

5. . . Photoresist layer

7. . . Metal precipitation layer

9. . . Circuit wiring

100. . . Circuit wiring substrate

Fig. 1 is a flow chart showing the main steps of a method of manufacturing a circuit wiring board according to an embodiment of the present invention.

2(a) to (f) are explanatory views of the steps of Fig. 1.

Claims (5)

A method for manufacturing a circuit wiring board, which is used for manufacturing a circuit wiring substrate formed by forming a circuit wiring on a polyimide film; and comprising the steps of: a) on a substrate, The polyimine precursor resin layer formed by coating and drying a polyimine precursor resin solution containing a polyimide precursor resin precursor is impregnated with an aqueous solution containing a metal ion and dried. a step of forming a metal ion-containing polyimine precursor resin layer; b) coating the surface of the metal ion-containing polyimine precursor resin layer with a photoresist layer to form a photoresist mask a step of: c) reducing the metal ions in the metal ion-containing polyimine precursor resin layer by a wet reduction method to precipitate the metal in a region not covered by the photoresist mask a step of forming a metal deposition layer on the surface layer portion of the imide precursor resin layer; d) a step of forming a circuit wiring having a pattern by electroless plating and/or plating on the metal deposition layer; and e) The aforementioned gathering The step of forming the polyimine resin layer by imidization of the imide precursor resin layer by heat treatment; further after step c and before step e, comprising: f) the polyimine precursor The resin layer is immersed in an aqueous citric acid solution or an aqueous oxalic acid solution to remove metal ions present in the polyimine precursor resin layer. The method for producing a circuit wiring board according to the first aspect of the invention, wherein the polyimine resin layer is composed of a plurality of layers. The method for producing a circuit wiring board according to the second aspect of the invention, wherein the polyimine resin layer composed of the plurality of layers has an on-line thermal expansion coefficient of 1 × 10 ^-6 to 30 × 10 ^-6 (1/ A low thermal expansion polyimine resin in the range of K) is formed by laminating a thermoplastic polyimide resin. The method for producing a circuit board according to any one of claims 1 to 3, wherein the sheet metal layer obtained in the step c has a sheet resistance of 50 Ω/□ or less. The method of manufacturing a circuit wiring board according to the fourth aspect of the invention, wherein in the step d, the plating is performed directly on the metal deposition layer.