JP5291008B2 - Method for manufacturing circuit wiring board - Google Patents

Abstract

Disclosed is a process for producing a circuit wiring board comprising a step (S1) of coating a coating liquid containing a polyimide precursor resin and a metal compound onto a base material to form a coating film, a step (S2) of forming a resist mask pattern on a surface of the coating film, a step (S3) of reducing metal ions in the coating film to form a metal deposit layer, a step (S4) of forming a circuit wiring having a pattern by plating on the metal deposit layer, and a step (S5) of heat treating the polyimide precursor resin layer to imidate the polyimide precursor resin and thus to form a polyimide resin layer.

Description

  The present invention relates to a method of manufacturing a circuit wiring board used for 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 resin layer.

  In an electronic circuit of an electronic device, a printed wiring board obtained by processing a laminated board made of an insulating material and a conductive material is used. A printed wiring board is formed by fixing a conductive pattern based on electrical design on the surface (and inside) of an insulating substrate with a conductive material. Depending on the type of insulating resin used as the base material, a plate-shaped rigid printed wiring is used. It is roughly divided into a board and a flexible printed wiring board which is rich in flexibility. The flexible printed wiring board is characterized by having flexibility, and is a necessary component for connection in a movable part that constantly bends. In addition, since the flexible printed wiring board can be stored in a bent state in an electronic device, it is also used as a space-saving wiring material. Insulating resins such as polyimide esters and polyimide resins are often used for the base material of the flexible substrate that is the material of the flexible printed wiring board, but the amount of heat-resistant polyimide resin is overwhelmingly large. On the other hand, copper foil is generally used as the conductive material from the viewpoint of conductivity.

  With recent miniaturization of electronic components and increase in signal transmission speed, fine fine pitch circuits are required on circuit boards such as flexible printed boards. As a method for forming a fine fine pitch circuit, methods such as vapor deposition and sputtering are known. However, the metal film formed by these methods has a large variation in adhesive strength with the polyimide resin substrate. There is a problem that pinholes are easily generated in the wiring. Furthermore, since the above method includes a step of removing an unnecessary seed layer on the polyimide resin substrate by an etching process, there is a concern that overetching may occur due to erosion of the etching solution to the wiring.

  In recent years, for example, a technique called a direct metallization method as disclosed in Patent Document 1 has been proposed as a technique that can maintain relatively good adhesion between a polyimide resin substrate and a metal film. A part of the metal film obtained by such a method is embedded in the resin of the polyimide resin base material, and high adhesion can be obtained. A method has been proposed in which such direct metallization is applied and the etching process of the seed layer is unnecessary. For example, in Patent Document 2, a pattern-shaped microchannel is formed on the surface of a polyimide resin substrate, an alkaline solution is supplied to the microchannel, and a modified layer is formed on the surface of the polyimide resin substrate. A method of forming a metal film by bringing a metal ion into contact with the modified layer and reducing the metal ion is disclosed. On the other hand, Patent Document 3 discloses a method in which a hydrophobic substance is attached to the polyimide surface and the exposed portion is selectively alkali-treated.

Japanese Unexamined Patent Publication No. 2001-73159 Japanese Unexamined Patent Publication No. 2007-103479 Japanese Unexamined Patent Application Publication No. 2007-242689

  However, as in the invention of Patent Document 2, in the pattern forming method for forming the microchannel, it is necessary to select an alkali-resistant material as a mask material for forming the microchannel groove. There is a problem that it is not easy. Further, the method of Patent Document 2 has a problem that high dimensional accuracy is required for processing of the mask material in order to improve pattern accuracy. In particular, if the processing accuracy of the contact portion between the polyimide resin base material and the mask material is low, a gap is formed between the two, and the processing liquid such as a metal ion-containing solution or a reducing solution oozes out there, so that the pattern accuracy is improved. There is a concern that the electrical characteristics of the circuit may be adversely affected.

  In the invention of Patent Document 3, it is necessary to perform plasma treatment in order to adhere a hydrophobic substance that does not dissolve in an alkaline aqueous solution to the polyimide surface, and plasma treatment is also necessary when removing the hydrophobic substance. is there. Further, in the invention of Patent Document 3, it is necessary to form a mask layer by a photolithography technique prior to the attachment of the hydrophobic substance and to peel off the mask layer after the attachment. This means that in order to pattern the hydrophobic substance as a mask, another mask layer (resist pattern) is formed and a step of peeling is necessary, and the number of steps is unnecessarily large. There was a problem of being complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a circuit wiring board having high adhesion reliability between a circuit wiring and an insulating resin layer with a fine fine pitch by simplifying a conventional complicated manufacturing process.

The method for manufacturing a circuit wiring board of the present invention is a method for manufacturing a circuit wiring board formed by forming circuit wiring on a polyimide resin layer,
a) A step of forming a coating film by applying a coating liquid containing a polyimide precursor resin, which is a precursor of a polyimide resin, and a metal compound on a substrate and drying the coating solution;
b) coating the surface of the coating film with a resist layer, forming a pattern and forming a resist mask;
c) reducing the metal ions in the coating film to deposit a metal in a region not covered with the resist mask in the surface layer portion of the coating film to form a metal deposition layer;
d) forming a circuit wiring having a pattern by electroless plating and / or electroplating on the metal deposition layer; and e) imidizing the polyimide precursor resin layer in the coating film by heat treatment, Forming a resin layer;
It is characterized by providing.

  Further, in the method for producing a circuit wiring board of the present invention, after the step a), f) the coating film is impregnated with an aqueous solution containing metal ions and dried to dry the metal in the coating film. And g) impregnating the coating film with an aqueous ammonia solution or an aqueous solution of a primary or secondary amine after the step of increasing the ion content or the step a). To do.

  According to the method for manufacturing a circuit wiring board of the present invention, a fine fine pitch circuit is formed by a simple process which simplifies the conventional complicated manufacturing process, such as eliminating the need for an etching process of a seed layer (metal deposition layer). Because it can, it does not require large-scale capital investment. In addition, since a circuit wiring board having high adhesion reliability between the circuit wiring and the insulating resin layer (polyimide resin layer) can be manufactured, its industrial value is high.

  Other objects, features and benefits of the present invention will become fully apparent from the following description.

It is a flowchart which shows the main process procedures of the manufacturing method of the circuit wiring board concerning embodiment of this invention. It is explanatory drawing of each process of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Base material, 3a ... Coating film, 3 ... Polyimide resin layer, 5 ... Resist layer, 7 ... Metal deposition layer, 9 ... Circuit wiring, 100 ... Circuit wiring board

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2 as appropriate. FIG. 1 is a flowchart showing the main process steps of the circuit wiring board manufacturing method according to the present embodiment, and FIG. 2 is an explanatory diagram of each process.

  The circuit wiring board 100 obtained by the manufacturing method of the present invention is formed by forming circuit wirings 9 on the polyimide resin layer 3 as shown in FIG. The aspect of the polyimide resin layer 3 is not particularly limited, and may be, for example, a polyimide resin film (sheet), or may be in a state of being laminated on the substrate 1 such as a metal foil, a glass plate, or a resin film. . Here, examples of the substrate 1 include a sheet-like resin on which the polyimide resin layer 3 is laminated, a glass substrate, ceramics, or a metal foil. In addition, the base material 1 may be comprised with the polyimide resin. The total thickness of the polyimide resin layer 3 can be in the range of 3 to 100 μm, preferably in the range of 3 to 50 μm.

  The polyimide resin can be formed by imidizing (curing) the polyimide precursor resin. The polyimide precursor resin here is a photosensitive group such as an ethylenically unsaturated hydrocarbon in its molecular skeleton. Those containing groups are also included. Details of imidization will be described later.

[Step a: Coating film forming step]
In the method for manufacturing a circuit wiring board according to the present embodiment, a coating liquid containing a polyimide precursor resin and a metal compound is applied onto the base material 1 and dried, as shown in FIG. 1 and FIG. As described above, the coating film 3a is formed (step S1).

  As a polyimide precursor resin (hereinafter sometimes simply referred to as “precursor”), a known polyimide resin precursor obtained from a known acid anhydride and diamine can be applied, and can be produced by a known method. it can. The precursor can be obtained, for example, by dissolving tetracarboxylic dianhydride and diamine in an organic solvent in an approximately equimolar amount and stirring the mixture at a temperature in the range of 0 to 100 ° C. for 30 minutes to 24 hours to cause a polymerization reaction. . In the reaction, it is preferable to dissolve the reaction components so that the obtained precursor is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight, in the organic solvent. As the organic solvent used for the polymerization reaction, it is preferable to use a polar one. Examples of the organic polar solvent include N, N-dimethylformamide, N, N-dimethylacetamide (DMAc), N-methyl. Examples include 2-pyrrolidone, 2-butanone, dimethyl sulfoxide, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, and triglyme. Two or more of these solvents can be used in combination, and some aromatic hydrocarbons such as xylene and toluene can also be used.

  The synthesized precursor is used as a solution. Usually, it is advantageous to use as a reaction solvent solution, but if necessary, it can be concentrated, diluted or replaced with another organic solvent. Moreover, since a precursor is generally excellent in solvent solubility, it is advantageously used. The solution thus prepared can be used as a coating solution by adding a metal compound.

  The precursor is preferably selected to include a thermoplastic polyimide resin after imidization. By using a thermoplastic resin, it is possible to improve the adhesion with the metal deposition layer 7 (described later). Such a thermoplastic polyimide resin preferably has a glass transition temperature of 350 ° C. or lower, more preferably 200 to 320 ° C.

As a precursor of a thermoplastic polyimide resin, what has a structural unit represented by following General formula (1) is preferable. In Formula (1), Ar ₁ represents a divalent aromatic group represented by Formula (2), Formula (3), or Formula (4), and Ar ₂ is represented by Formula (5) or Formula (6). Represents a tetravalent aromatic group. In the formulas (2) to (4), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, n independently represents an integer of 0 to 4, and X and W are 2 independently selected from a single bond or —C (CH ₃ ) ₂ —, — (CH ₂ ) _m —, —O—, —S—, —CO—, —SO ₂ —, —NH— or —CONH—. Represents a valent group, and p represents the molar ratio of the constituent units and is in the range of 0.1 to 1.0.

In the general formula (1), Ar ₁ can be referred to as a diamine residue, and Ar ₂ can be referred to as an acid anhydride residue. Therefore, a preferred polyimide resin will be described using a diamine and an acid anhydride. However, the precursor of the thermoplastic polyimide resin is not limited to that obtained by this method.

  Examples of diamines suitably used for preparing a thermoplastic polyimide resin precursor include 4,4′-diaminodiphenyl ether, 2′-methoxy-4,4′-diaminobenzanilide, 1,4-bis (4 -Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethyl-4,4'-diamino Biphenyl, 3,3′-dihydroxy-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide and the like can be mentioned. In addition, the diamine mentioned by description of the low thermal expansion polyimide resin mentioned later can be used. Among them, particularly preferred diamine components include 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), paraphenylenediamine (p-PDA), 3,4'-diaminodiphenyl ether (DAPE34), 4,4'-diaminodiphenyl ether (DAPE44) One or more selected diamines may be mentioned.

  Examples of the acid anhydride suitably used for the preparation of the thermoplastic polyimide resin precursor include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, and 3,3 ′. 4,4'-diphenylsulfone tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride. In addition, the acid anhydrides mentioned in the description of the low thermal expansion polyimide resin described later can be used. Among them, particularly preferred acid anhydrides include pyromellitic anhydride (PMDA), 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3', 4,4'- Examples thereof include at least one acid anhydride selected from benzophenone tetracarboxylic dianhydride (BTDA) and 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA).

  Each diamine and acid anhydride may be used alone or in combination of two or more. In addition, diamines and acid anhydrides other than those described above can be used in combination.

  In the precursor of the thermoplastic polyimide resin, the structural unit represented by the general formula (1) may be present in the homopolymer or may be present as a structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may exist as a block copolymer or a random copolymer. The structural unit represented by the formula (1) is plural, but may be one type or two or more types. Advantageously, the main component is the structural unit represented by the formula (1), and the precursor preferably contains 60 mol% or more, more preferably 80 mol% or more.

  In this Embodiment, in order to prepare a coating liquid, a commercial item can also be used suitably as a solution containing a precursor. For example, Nippon Steel Chemical Co., Ltd. thermoplastic polyimide precursor resin varnish SPI-200N (trade name), SPI-300N (trade name), SPI-1000G (trade name), Toray Industries Co., Ltd. 3000 (trade name) and the like.

  As the metal compound contained in the coating solution together with the precursor, a compound containing a metal species having a redox potential higher than the redox potential of the reducing agent used in the reduction treatment (described later) for forming the metal deposition layer 7 is used. It can be used without any particular limitation. Examples of the metal compound include those containing 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 metal, an organic carbonyl complex, or the like can be used. Examples of the metal salt include hydrochloride, sulfate, acetate, oxalate, and citrate. Metal salts are preferably used when the metal is Cu, Ni or Pd. Examples of the organic carbonyl compound capable of forming an organic carbonyl complex with the above metal species include β-diketones such as acetylacetone, benzoylacetone and dibenzoylmethane, and β-ketocarboxylic acid esters such as ethyl acetoacetate. it can.

Preferred specific examples of the metal _{compound, 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 and the} like. be able to.

  In the coating solution containing the precursor and the metal compound, a three-dimensional cross-linking reaction occurs between the metal ion generated by dissociation of the metal compound and the precursor. For this reason, the thickening and gelation of the coating solution proceed with the passage of time, and it may be difficult to apply to the substrate 1. In order to prevent such thickening and gelation, it is preferable to add a viscosity modifier as a stabilizer in the coating solution. By adding the viscosity modifier, the viscosity modifier and the metal ion form a chelate complex instead of the metal ion in the coating solution forming a chelate complex with the precursor. As described above, the viscosity modifier blocks the three-dimensional cross-linking between the precursor and the metal ion, and suppresses thickening and gelation.

  As the viscosity modifier, it is preferable to select a low-molecular organic compound that is highly reactive with metal ions (that is, capable of forming a metal complex). The molecular weight of the low molecular weight organic compound is preferably in the range of 50 to 300. Specific examples of such a viscosity modifier include acetylacetone, ethyl acetoacetate, pyridine, imidazole, picoline and the like. Moreover, it is preferable to add the addition amount of a viscosity modifier in the range of 1-50 mol with respect to 1 mol of chelate complex compounds which can be formed, Preferably it is in the range of 2-20 mol.

  The compounding amount of the metal compound in the coating solution is within the range of 5 to 60 parts by weight, preferably within the range of 10 to 40 parts by weight, with respect to 100 parts by weight of the total of the precursor, the metal compound and the viscosity modifier. To be. In this case, when the metal compound is less than 5 parts by weight, the reduction of the metal particles on the surface of the polyimide precursor resin layer is reduced by the reduction treatment, so that the thickness of the conductor layer (for example, the electroless plating layer) becomes uneven. This is because if it exceeds 60 parts by weight, a metal salt that cannot be dissolved in the coating solution will precipitate.

  In addition, a leveling agent, an antifoamer, adhesiveness imparting agent, a crosslinking agent etc. can be mix | blended with the coating liquid as arbitrary components other than the said component, for example.

  The method for applying the coating liquid onto the substrate 1 is not particularly limited, and for example, it can be applied with a coater such as a comma, a die, a knife, or a lip.

Moreover, after apply | coating a coating liquid on the base material 1, it is made to dry and the coating film 3a is formed. In drying, the temperature is controlled so as not to complete imidization due to the progress of dehydration and ring closure of the precursor. The drying method is not particularly limited, and for example, the drying may be performed under a temperature condition in the range of 60 to 200 ° C. over a time period in the range of 1 to 60 minutes, preferably 60 to 150 ° C. It is preferable to perform drying under temperature conditions within the range. It is necessary to leave the precursor state in order to impregnate the aqueous solution containing metal ions. The precursor layer after drying may have part of the precursor structure imidized, but the imidization rate should be 50% or less, more preferably 20% or less, leaving the precursor structure at 50% or more. Is good. In addition, the imidation ratio of the precursor is 1,000 cm by measuring the infrared absorption spectrum of the polyimide thin film by a transmission method using a Fourier transform infrared spectrophotometer (commercially available product: FT / IR620 manufactured by JASCO Corporation). ^-1 benzene ring carbon hydrogen bond as a reference is calculated from the absorbance from the imide groups 1,710Cm ^-1.

  The coating film 3a may be a single layer or may have a laminated structure formed from a plurality of coating films 3a. In the case of a plurality of layers, it can be formed by sequentially coating other precursors on precursor layers made of different constituent components. When the precursor layer is composed of three or more layers, the precursor having the same configuration may be used twice or more. Two layers or a single layer, in particular a single layer, having a simple layer structure can be advantageously obtained industrially. Moreover, the thickness (after drying) of the coating film 3a is preferably in the range of 3 to 100 μm, and preferably in the range of 3 to 50 μm.

  In forming the coating film 3a composed of a plurality of layers, the metal compound may be included in all layers, or the metal compound may be included only in a part of the layers. It is preferable that the metal compound is contained only in the precursor layer on the side to be formed (outermost layer).

When the coating film 3a is composed of a plurality of layers, it is preferable to form a precursor layer so that the polyimide resin layer 3 in contact with the circuit wiring 9 after imidization described later becomes a thermoplastic polyimide resin layer. Moreover, it is preferable to form at least one layer of the plurality of layers with a precursor layer that becomes a low thermal expansion polyimide resin after imidization. Applying such a low thermal expansion polyimide resin as an insulating resin layer is advantageous because warpage as a circuit wiring board can be suppressed. When the polyimide resin layer is composed of a low thermal expansion polyimide resin layer and a thermoplastic polyimide resin layer, 1/2 or more of the total thickness, preferably 2/3 to 9/10 is low thermal expansion polyimide resin It is better to make up with layers. Further, from the viewpoint of heat resistance and dimensional stability, the thickness of one layer of the thermoplastic polyimide resin layer is preferably 5 μm or less, and preferably in the range of 1 to 4 μm. The linear thermal expansion coefficient of the entire polyimide resin layer is 30 × 10 ⁻⁶ (1 / K) or less, preferably 5 × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K). .

Specifically, the low thermal expansion polyimide resin has a linear thermal expansion coefficient in the range of 1 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K), preferably 1 × 10 ^{−6 to} 25 × 10 ^{−. 6} (1 / K), more preferably 15 × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K). Such a low thermal expansion polyimide resin is preferably a polyimide resin having a structural unit represented by the following general formula (7). In Formula (7), Ar ₃ represents a tetravalent aromatic group represented by Formula (8) or Formula (9), and Ar ₄ represents a divalent group represented by Formula (10) or Formula (11). Represents an aromatic group, R ₂ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and V and Y independently represent a single bond or a divalent hydrocarbon group having 1 to 15 carbon atoms. , O, S, CO, SO, SO ₂ or CONH, m is independently an integer of 0 to 4, q is the molar ratio of the constituent units, The range is 1.0.

  The structural unit may be present in the homopolymer or may be present as a structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may exist as a block copolymer or a random copolymer.

In the general formula (7), Ar ₃ can be referred to as an acid anhydride residue, and Ar ₄ can be referred to as a diamine residue. Therefore, a preferred polyimide resin will be described using an acid anhydride and a diamine. However, the low thermal expansion polyimide resin is not limited to that obtained by this method.

  Acid anhydrides used to form low thermal expansion polyimide resins include pyromellitic anhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'- Preferred examples include diphenylsulfonetetracarboxylic dianhydride and 4,4′-oxydiphthalic anhydride. Moreover, 2,2 ', 3,3'-, 2,3,3', 4'- or 3,3 ', 4,4'-benzophenonetetracarboxylic 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 are also preferred. In addition, 3,3``, 4,4 ''-, 2,3,3 '', 4 ''-or 2,2 '', 3,3 ''-p-terphenyltetra Carboxylic dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3.4-dicarboxyphenyl) methane dianhydride, bis Preferred examples include (2,3- or 3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride and the like.

  Other acid anhydrides such as 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7 -Anthracene tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) 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-tetracarboxylic Acid dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1,4,5,8- (or 2,3,6,7-) tetracarboxylic acid Dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetracarboxylic dianhydride, cyclopentane -1,2,3,4-teto Lacarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5- Examples thereof include tetracarboxylic dianhydride and 4,4′-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride.

  Diamines used to form low thermal expansion polyimide resins include 4,4'-diaminodiphenyl ether, 2'-methoxy-4,4'-diaminobenzanilide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3 Preferred examples include '-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide and the like. Diamines include 2,2-bis- [4- (3-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, and bis [4- (3-aminophenoxy) phenyl. ] Sulfone, bis [4- (4-aminophenoxy)] biphenyl, bis [4- (3-aminophenoxy) biphenyl, bis [1- (4-aminophenoxy)] biphenyl, bis [1- (3-aminophenoxy) )] Biphenyl, bis [4- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy)] benzophenone, bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 '-(4-aminophenoxy)] Ben Anilide, bis [4,4 '-(3-aminophenoxy)] benzanilide, 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene, 9,9-bis [4- (3-aminophenoxy) Preferred examples include phenyl] fluorene and the like.

  Other diamines include, for example, 2,2-bis- [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis- [4- (3-aminophenoxy) phenyl] hexafluoropropane, 4 , 4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 4,4'-diaminodiphenylpropane, 3,3 ' -Diaminodiphenylpropane, 4,4'-diaminodiphenylethane, 3,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3, 3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl 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-diaminopyridine, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 4,4'-[1,3-phenylenebis (1-methylethylidene)] 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-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine and the like can be mentioned.

  Each of acid anhydrides and diamines can be used alone or in combination of two or more. In addition, other acid anhydrides or diamines not included in the general formula (7) can be used together with the acid anhydrides or diamines. In this case, other acids not included in the general formula (7) The proportion of anhydride or diamine used is 90 mol% or less, preferably 50 mol% or less. By controlling the types of acid anhydrides or diamines and the molar ratios when using two or more acid anhydrides or diamines, the thermal expansion, adhesion, glass transition point (Tg), etc. are controlled. be able to.

  As the precursor solution of the non-thermoplastic polyimide resin, a commercially available product can be suitably used. For example, U-Varnish-A (trade name) which is a non-thermoplastic polyimide precursor resin varnish manufactured by Ube Industries, Ltd. U-varnish-S (brand name) etc. are mentioned.

[Step b: Resist pattern forming step]
Next, as shown in FIGS. 1 and 2B, the surface of the coating film 3a formed as described above is covered with a resist layer 5 as a mask to form a resist pattern (step S2). A known method can be applied to the formation of the resist pattern, and is not particularly limited. For example, it is possible to use a photolithography technique in which a photosensitive resist is laminated or coated on the surface of the coating film 3a to form the resist layer 5, and then exposed, developed, and cured to form a resist pattern.

[Step c; Metal precipitation layer forming step]
Next, in the method for manufacturing a circuit board according to the present embodiment, as shown in FIGS. 1 and 2C, metal ions in the coating film 3a are applied to the exposed regions not masked by the resist layer 5. By reducing, the metal deposit layer 7 is formed (step S3). As the reduction treatment method, it is particularly advantageous to use a wet reduction method. The wet reduction method is a method of reducing metal ions in an exposed region that is not masked by the resist layer 5 by immersing the coating film 3a in a solution containing a reducing agent (reducing agent solution). In this wet reduction method, metal ions existing inside the coating film 3a (for example, a deep layer portion deeper than the surface layer portion or a coating portion immediately below the resist layer 5) are reduced and deposited as metal at that location. This is an effective method capable of preferentially performing metal deposition in the surface layer portion of the coating film 3a while suppressing this. Further, in the wet reduction method, there is little unevenness of metal deposition, and it is possible to form a uniform metal deposition layer 7 in a short time. Since the metal deposit layer 7 obtained in this way is partially embedded in the surface layer portion of the coating film 3a (polyimide precursor resin layer), high adhesion can be obtained.

  As the reducing agent, for example, boron compounds such as sodium borohydride, potassium borohydride, dimethylamine borane and the like are preferable. These boron compounds can be used in the form of a solution (reducing agent solution) of sodium hypophosphite, formalin, hydrazines, and the like. The concentration of the boron compound in the reducing agent solution is preferably in the range of 0.005 to 0.5 mol / L, for example, and more preferably in the range of 0.01 to 0.1 mol / L. When the concentration of the boron compound in the reducing agent solution is less than 0.005 mol / L, reduction of the metal ions contained in the coating film 3a may be insufficient, and when it exceeds 0.5 mol / L, the action of the boron compound Thus, the polyimide precursor resin may be dissolved.

  In the wet reduction treatment, the region not masked by the resist layer 5 is placed in a reducing agent solution at a temperature in the range of 10 to 90 ° C., preferably in the range of 50 to 70 ° C., for 20 seconds to 30 minutes. The immersion is preferably performed for 30 seconds to 10 minutes, more preferably for 1 minute to 5 minutes. By soaking, the metal ions in the coating film 3a are reduced by the action of the reducing agent, and the metal is deposited in the form of particles on the surface layer portion of the coating film 3a. At the end point of reduction, there is almost no metal ion other than the surface layer portion in the coating film 3a (for example, the deep layer portion or the coating portion immediately below the resist layer 5). This is because as the metal deposits on the surface layer portion of the coating film 3a, the metal ions in the coating film 3a move to the surface layer portion of the unmasked region in the coating film 3a while maintaining a uniform concentration distribution. This is thought to be because the moved metal ions are reduced in the vicinity of the surface layer and metal precipitation occurs. At the end of the reduction, almost no metal ions remain in the coating film 3a, but even if metal ions remain in the coating film 3a, the remaining metal ions are removed by acid treatment described later. Can do. The determination of the end point of reduction can be confirmed, for example, by measuring the cross section of the coating film 3a using an energy dispersive X-ray (EDX) analyzer and reading the atomic weight% of the remaining metal ions.

  In the present embodiment, the metal deposition layer 7 that becomes the seed layer of the circuit wiring 9 is formed only in a portion not covered with the patterned resist layer 5 and is not formed under the resist layer 5. In addition, a flash etching process for removing the seed layer is unnecessary, and it is possible to reduce the number of processes and improve the reliability of the circuit wiring board.

[Step d: Circuit wiring forming step]
Next, as shown in FIG. 1 and FIG. 2D, a circuit wiring 9 having a pattern is formed on the metal deposition layer 7 by electroless plating and / or electroplating (step S4). The electroless plating is performed by immersing the coating film 3a on which the metal deposition layer 7 is formed in an electroless plating solution (electroless plating step). By this electroless plating, an electroless plating layer is formed. This electroless plating layer becomes the core of electroplating performed later.

  As the electroless plating solution used in the electroless plating process, a neutral to weakly acidic hypophosphorous acid nickel plating solution or boron-based nickel plating solution is selected in consideration of the influence on the polyimide precursor resin. It is preferable. As a commercially available product of a hypophosphorous acid nickel plating solution, for example, Top Nicolon (trade name; manufactured by Okuno Pharmaceutical Co., Ltd.) can be mentioned. Examples of commercially available boron-based nickel plating solutions include Top Chemialoy B-1 (trade name; manufactured by Okuno Pharmaceutical Co., Ltd.) and Top Chemialoy 66 (trade name; manufactured by Okuno Pharmaceutical Industries, Ltd.). Can do. Moreover, it is preferable to adjust the pH of the electroless plating solution to neutral to slightly acidic 4-7. In this case, for example, inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, boric acid and carbonic acid, and organic acids such as acetic acid, glycolic acid, citric acid and tartaric acid can be used. Furthermore, boric acid, carbonic acid, acetic acid, A weak acid such as citric acid and these alkali salts may be combined to provide a buffering action. The temperature of the electroless plating treatment can be in the range of 80 to 95 ° C, and preferably in the range of 85 to 90 ° C. Moreover, the processing temperature of an electroless-plating process can be made into 20 second-10 minutes, Preferably it is 30 second-5 minutes, More preferably, it is 1 minute-3 minutes.

Next, electroplating is performed using the electroless plating layer as a core to form an electroplating layer (electroplating step). An electroplating layer is formed by electroplating so as to cover the electroless plating layer. In electroplating, for example, in a plating solution having a composition containing sulfuric acid, copper sulfate, hydrochloric acid, and a brightener [for example, McCuispec (trade name) manufactured by Nihon McDermitt as a commercial product], an electroless plating layer is used as a cathode, A metal such as Cu is used as an anode. Current density in electroplating, for example, is preferably in the range of 0.2~3.5A / dm ^2. As the anode for electroplating, for example, metals such as Ni and Co can be used in addition to Cu.

  After the circuit wiring 9 having a pattern is formed, the resist layer 5 that has become unnecessary is peeled off. Although the method of peeling the resist layer 5 is not ask | required, For example, the method of immersing in alkaline solutions, such as 1 to 4 weight% concentration sodium hydroxide aqueous solution and potassium hydroxide aqueous solution, etc. are preferable. In addition, if the resist layer 5 is peeled after imidization, the resist layer 5 may be peeled off in the next step because the resist resin 5 may adversely affect the polyimide resin due to the action of an alkaline solution for resist peeling. It is preferably performed before imidation of the precursor resin. However, when the resist layer 5 is a part of the inter-circuit insulating layer of the circuit wiring 9, the resist layer 5 does not need to be peeled off.

  Here, the removal of metal ions in the coating film 3a will be described. In the wet reduction process, for example, when a metal salt such as sodium borohydride, potassium borohydride, dimethylamine borane or the like is used, or when removing the resist layer 5, a metal salt such as sodium hydroxide or potassium hydroxide is used. In this case, since metal ions derived from the metal salt may be present in the coating film 3a, it is preferable to remove them. The removal of metal ions is preferably performed by immersing in an aqueous solution of acid, and the applicable acid in this case dissociates the metal ions coordinated with the carboxyl groups of the polyamic acid. It is preferable to select a strong acid (acid dissociation constant pKa of 3.5 or less), and it is more preferable to select an acid that does not dissolve the metal deposited by reduction. Specific examples of such acids include citric acid (pKa = 2.87) and oxalic acid (pKa = 1.04). Note that strong acids such as hydrochloric acid, nitric acid, and sulfuric acid may dissolve the metal deposition layer 7, and acetic acid (pKa = 4.56) is not preferable because the strength of the acid is low and it is difficult to remove metal ions. . As conditions for the immersion treatment for removing metal ions, an aqueous acid solution having a concentration in the range of 1 to 15% by weight, preferably in the range of 5 to 10% by weight and in the range of 20 to 50 ° C., It is preferable to immerse for a time within a range of 2 to 10 minutes. By performing such acid treatment, metal ions derived from the metal compound remaining in the coating film 3a can be removed at the same time after the reduction or after the resist layer is peeled off. The method for removing metal ions is also disclosed in, for example, “17th Microelectronics Symposium Proceedings”, September 2007, pages 179-182.

[Step e; Imidization step]
Next, as shown in FIGS. 1 and 2E, the coating film 3a is imidized by heat treatment to form a polyimide resin layer 3 (step S5). The imidization method is not particularly limited, and for example, a heat treatment in which heating is performed under a temperature condition in the range of 80 to 400 ° C. over a period of 1 to 60 minutes is suitably employed. In order to suppress metal oxidation of the circuit wiring layer 9 formed by reduction and plating, heat treatment in a low oxygen atmosphere is preferable. Specifically, reduction of hydrogen or the like in an inert gas atmosphere such as nitrogen or a rare gas is preferable. It is preferable to carry out in a gas atmosphere or in a vacuum. Further, the imidization process in step S5 is preferably performed after the circuit wiring formation process in step S4, but there is no problem even if it is performed before the process in step S4.

[Step f; metal ion impregnation step]
In the method for producing a circuit wiring board of the present invention, after the step a, further, f) the coating film 3a is impregnated with an aqueous solution (metal ion solution) containing metal ions, and dried to dry the coating film 3a. It is preferable to provide a step of increasing the content of metal ions. By this impregnation treatment, a free carboxyl group present in the coating film 3a, that is, a carboxyl group that does not form a salt with a metal derived from a metal compound can be converted into a metal salt.

  As the metal ions used in the step f (metal ion impregnation step), the same metal compounds as those contained in the coating solution used in the step a (coating film forming step) can be used.

  In the metal ion solution used in the metal ion impregnation step, the metal compound is preferably contained within a range of 30 to 300 mM, and more preferably within a range of 50 to 100 mM. If the concentration of the metal compound is less than 30 mM, too much time is required for impregnating the metal ions into the coating film 3a, which is not preferable. If it exceeds 300 mM, the surface of the coating film 3a may be corroded (dissolved).

  In addition to the metal compound, the metal ion solution can contain components intended for pH adjustment such as a buffer solution.

  The impregnation method is not particularly limited as long as the metal ion solution can come into contact with the surface of the coating film 3a, and a known method can be used. For example, a dipping method, a spray method, a brush coating method or a printing method can be used. The impregnation temperature may be 0 to 100 ° C., preferably 20 to 40 ° C. The impregnation time is preferably 1 minute to 5 hours, for example, and more preferably 5 minutes to 2 hours, when applying the dipping method. Even when the immersion time exceeds 5 hours, the degree of impregnation of the coating film 3a with metal ions tends to be almost flat.

  Dry after impregnation. The drying method is not particularly limited, and for example, natural drying, spray drying with an air gun, drying with an oven, or the like can be used. Drying conditions are 10 to 150 ° C. for 5 seconds to 60 minutes, preferably 25 to 150 ° C. for 10 seconds to 30 minutes, and more preferably 30 to 120 ° C. for 1 minute to 10 minutes.

  After step f, it is preferable to perform a resist pattern formation step in step b and a metal deposit layer formation step in step c. By providing step f, metal ions in coating film 3a, which is a polyimide precursor resin layer, are formed. The amount (that is, the content of metal ions in the coating film 3a) can be increased. As a result, the metal deposition layer 7 obtained in the step c can be formed into a film, so that the electroless plating step can be omitted. Electroless plating has the problem of complicated plating solution management and waste liquid treatment, so if circuit wiring with excellent adhesion to the substrate can be formed without using electroless plating, the industry The target value is very large. From this point of view, it is particularly preferable that after the coating film 3a is formed in the step a, a metal ion impregnation step of the step f is further performed to increase the amount of metal ions in the coating film 3a. By selecting the resist material used in the resist pattern forming step of step b, the coating film 3a not covered with the patterned resist layer 5 is provided after step b (that is, before step c). In some cases, the metal ion solution may be brought into contact with the exposed portion of the metal to perform the metal ion impregnation step of step f.

[Step g; amine treatment step]
In the method for manufacturing a circuit wiring board according to the present invention, after the step a), g) a step of impregnating the coating film 3a with an aqueous ammonia solution or a primary or secondary amine aqueous solution may be provided. preferable. By impregnating with an ammonia aqueous solution or a primary or secondary amine aqueous solution (hereinafter also referred to as an amine aqueous solution), the amine in the amine aqueous solution becomes a ligand of a chelate complex of a metal ion present in the coating film 3a. Ligand substitution produces a metal ion amine complex. The amine complex thus formed is in a state in which the ligand is easily liberated when the metal ion is reduced, and as a result, the reduction reaction of the metal ion is considered to occur uniformly in the surface layer portion of the coating film 3a. The primary or secondary amine is not particularly limited as long as it is water-soluble, but is preferably an aliphatic amine. Specific examples of such aliphatic amines include ethanolamine, propanolamine, butanolamine, diethanolamine, dipropanolamine, ethylenediamine, diethylamine and the like. Of the aliphatic amines, alcohol amines such as ethanolamine, propanolamine, butanolamine, diethanolamine, and dipropanolamine are more preferable. Among these, ammonia that is easy to handle and excellent in economy is particularly preferable. As the aqueous amine solution, the concentration is used within the range of 1 to 30% by weight, preferably within the range of 10 to 30% by weight, and the liquid temperature is within the range of 1 to 80 ° C., preferably within the range of 10 to 50 ° C. It is preferable. The method for impregnating the aqueous amine solution is not particularly limited. For example, a dipping method, a spray method, or brushing can be applied. For example, when the immersion method is applied, it is effective to perform the treatment for 10 seconds to 2 hours, preferably 1 to 30 minutes. If the concentration or temperature of the aqueous amine solution is less than the above lower limit, ligand substitution tends to be insufficient, and if it exceeds the above upper limit, metal ions present in the coating film 3a tend to elute. .

  The impregnated coating film 3a may be subjected to the next step as it is, and the impregnated coating film 3a may be dried after the impregnation.

  After the amine treatment step of step g, it is preferable to perform the resist pattern formation step of step b and the metal precipitation layer formation step of step c. By providing step g, the metal precipitation layer 7 obtained in step c is formed into a film. Therefore, the electroless plating process can be omitted.

  When it is desired to omit the electroless plating step by performing the above steps f and g, it is advantageous to set the thickness of the coating film 3a to 2 μm or more. With such a thickness, a sufficient amount of metal ions can be contained in the coating film 3a. Note that either one of the metal ion impregnation step of the step f and the amine treatment step of the step g may be performed, but both the step f and the step g can be performed. In this case, it is preferable because a dense film-like metal deposition layer 7 can be formed. When performing both the process f and the process g, the order is not ask | required, but it is preferable to perform the process g after the process f.

  The manufacturing method of the circuit wiring board according to the present embodiment includes the insulating resin layer having the base material 1 and the polyimide resin layer 3 by performing the above steps a to e and, if necessary, the step f and / or the step g. The circuit wiring board 100 on which the circuit wiring 9 having excellent adhesion is formed can be manufactured. This method is a simple method that requires a small number of steps and does not require special equipment or equipment, and also eliminates the need for an etching step for removing the metal deposition layer. Is.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples. Unless otherwise specified in the examples of the present invention, various measurements and evaluations are as follows. Further, the abbreviations used in this example are as described above.

[Evaluation of adhesion]
For evaluation of adhesion, a test piece for measuring 3 mm width circuit wiring is prepared, and using a strograph-M1 (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the peel strength is measured in the 90 ° direction at room temperature, and the strength is measured. evaluated. The evaluation of adhesion has no practical problem if the peel strength is 0.5 kN / m or more, but in order to obtain better adhesion, it should be 1.0 kN / m or more. preferable.

[Measurement of linear thermal expansion coefficient]
The coefficient of linear thermal expansion was determined by using a thermomechanical analyzer (manufactured by Seiko Instruments Inc.), raising the temperature of the sample to 250 ° C., holding the sample at that temperature for 10 minutes, and then cooling at a rate of 5 ° C./min. To an average linear thermal expansion coefficient (CTE) from 100 ° C to 100 ° C.

[Measurement of glass transition temperature]
The glass transition temperature was measured at a rate of 10 ° C./min from room temperature to 400 ° C. while applying a 1 Hz vibration using a 10 mm wide sample using a viscoelasticity analyzer (RSA-II manufactured by Rheometric Science Effy Co., Ltd.). It was determined from the maximum loss tangent (Tan δ) when the temperature was raised at.

[Measurement of average particle diameter of metal particles deposited after reduction treatment]
The cross section of the sample was observed at a magnification of 50,000 times using a scanning transmission electron microscope (manufactured by Hitachi High-Technologies Corporation), and the average particle diameter of all the observed metal particles was obtained.

[Measurement of sheet resistance of metal layer]
The sheet resistance of the metal layer was measured by a method based on JIS K 7194 using a resistivity meter (MCP-T610 manufactured by Mitsubishi Chemical Corporation). In addition, when the measured value of the sheet resistance of the metal layer exceeds 50Ω / □ (ohm / square), the level is “difficult electroplating”, and when it is 50Ω / □ or less, the level is “possible electroplating”. It was evaluated. Moreover, when it was 30 Ω / □ or less, the metal layer was evaluated as “particularly excellent” as a conductive film.

[Evaluation method of warpage]
The conductor layer forming resin film is cut by a cutting machine to create a sheet of 10 cm × 10 cm size, and when the sheet is placed on the desk, the height from the desk surface of the part that is the most lifted from the desk surface is set. Measured using calipers. The height was taken as the amount of warpage of the conductor layer-forming resin film, and when the amount of warpage was less than 2 mm, it was evaluated as “no warp”.

Production Example 1
In a 500 ml separable flask, 20.7 g of 2′-methoxy-4,4′-diaminobenzanilide (0.08 mol) was dissolved in 343 g of DMAc with stirring. Next, 28.5 g PMDA (0.13 mol) and 10.3 g DAPE44 (0.05 mol) were added to the solution in a nitrogen stream. Thereafter, polymerization reaction was continued to stir for about 3 hours to obtain a viscous polyimide precursor resin solution S _1.

The resulting polyimide precursor resin solution S ₁ was applied on a stainless steel substrate, and dried 5 minutes at 130 ° C., to complete the over 15 minutes allowed to warm to 360 ° C. imidization, the stainless steel substrate A laminated polyimide film was obtained. The polyimide film was peeled from the stainless steel substrate, to obtain a polyimide film S ₂ of 25μm in thickness. Linear thermal expansion coefficient of the polyimide film _{S 2} was ^{14.6 × 10 -6 (1 / K} ).

Production Example 2
In a 500 ml separable flask, 20.5 g BAPP (0.05 mol) was dissolved in 250 g DMAc with stirring. Next, 14.7 g of BPDA (0.05 mol) was added to the solution under a nitrogen stream. Thereafter, polymerization reaction was continued to stir for about 3 hours to obtain a viscous polyimide precursor resin liquid T _1.

The resulting polyimide precursor resin solution T ₁ was coated on a stainless steel substrate and dried for 5 minutes at 130 ° C.. Thereafter, the coating film was heated to 360 ° C. over 15 minutes to complete imidization, and the substrate was removed to obtain a polyimide film T ₂ having a thickness of 5 μm. The resulting glass transition temperature of the polyimide film _{T 2} are 252 ° C., the linear thermal expansion coefficient of ^{52 × 10 -6 (1 / K} ).

Production Example 3
The polyimide precursor resin solution _{T 1} prepared in Preparation Example 2 was added pyridine 7.91 g (0.1 mol), and stirred for 20 min. A solution of 22.0 g (0.08 mol) of commercially available nickel (II) acetylacetonate dihydrate dissolved in 160 ml of N-methyl-2-pyrrolidinone (hereinafter abbreviated as NMP) was added to this mixture. By stirring at room temperature for 1 hour, a blue polyimide precursor nickel complex solution A was prepared.

Production Example 4
A test piece 12.5 cm × 12.5 cm (thickness 0.7 mm) of alkali-free glass (Asahi Glass Co., Ltd. AN-100) was treated with a 5N sodium hydroxide aqueous solution at 50 ° C. for 5 minutes. Next, the glass substrate of the test piece was washed with pure water and dried, and then immersed in a 1 wt% aqueous solution of 3-aminopropyltrimethoxysilane (hereinafter abbreviated as “γ-APS”). The 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]
On the glass base material G, the polyimide precursor nickel complex solution A was apply | coated so that the thickness after imidation might be set to 1.4 micrometers, and the coating film a1 was obtained by drying at 130 degreeC for 20 minute (s).

  Next, a dry film resist (manufactured by Asahi Kasei Co., Ltd., trade name: Sunfort AQ, 10 μm thickness) is laminated on the surface of the coating film a1 at a temperature of 110 ° C., and exposed to ultraviolet rays through a photomask. Development was performed with a 5% by weight aqueous sodium carbonate solution to form a resist pattern of 50 μm {wiring width / wiring spacing (L / S) = 20 μm / 30 μm} to obtain a glass substrate b1 on which the resist pattern was formed.

The glass substrate b1 is immersed in a 50 mM aqueous solution of sodium borohydride (50 ° C.) for 3 minutes to form a nickel deposition layer on the surface of the coating film a1 in a region not masked with a resist layer, thereby obtaining a glass substrate c1. It was. When cross-sectional observation of the surface layer portion of the coating film a1 was performed, nickel particles having an average particle diameter of about 40 nm were densely present from the outermost surface of the coating film a1 to a depth of about 100 nm (the nickel particles were embedded). I confirmed that Next, the glass substrate c1 is immersed in an electroless nickel plating bath (Okuno Pharmaceutical Co., Ltd., trade name: Top Nicolon TOM-S) at 80 ° C. for 30 seconds, thereby providing a base for electrolytic copper plating. A nickel layer was formed. Further, the formed nickel layer was electroplated at an electric current density of ² A / dm ^{2 in} an electric copper plating bath to form a copper wiring having a copper film thickness of 10 μm, thereby obtaining a glass substrate d1.

  The obtained glass substrate d1 is immersed in a 2% by weight sodium hydroxide aqueous solution (25 ° C.) for 3 minutes to remove the resist pattern, and then immersed in a 10% by weight oxalic acid aqueous solution (25 ° C.) for 2 minutes. The residual metal ions were removed.

  The glass substrate d1 was washed with ion-exchanged water, then heated to 300 ° C. under a nitrogen atmosphere, and the polyimide precursor resin was imidized at the same temperature for 5 minutes. Then, it cooled to normal temperature in nitrogen atmosphere, and obtained the copper wiring formation glass substrate e1. The obtained copper wiring-formed glass substrate e1 had a copper wiring peeling strength of 1.4 kN / m and excellent adhesion.

[Example 2]
On a stainless steel substrate, the thickness after imidization by applying a polyimide precursor resin solution S ₁ so that 25 [mu] m, followed by drying at 130 ° C. 20 minutes to obtain a polyimide precursor resin layer. On this resin layer, the polyimide precursor nickel complex solution A was apply | coated so that the thickness after imidation might be set to 1.4 micrometers, and the coating film a2 was obtained by drying at 130 degreeC for 20 minute (s).

  A polyimide precursor resin layer b2, a nickel deposition precursor resin layer c2, on which a resist pattern is formed, copper, and copper, in the same manner as in Example 1, except that the coating film a2 is used instead of the coating film a1 in Example 1. A wiring formation precursor resin layer d2 and a copper wiring formation polyimide resin layer e2 were obtained. When the cross section of the surface layer portion of the coating film a2 was observed, nickel particles having an average particle diameter of about 50 nm were densely present from the outermost surface of the coating film a2 to a depth of about 100 nm (the nickel particles were embedded). ) The obtained copper wiring formation polyimide resin layer e2 was peeled from the stainless steel base material to obtain a copper wiring formation film e2 '. The obtained copper wiring formation film e2 'had no warping, the peel strength of the copper wiring was 1.4 kN / m, and was excellent in adhesion.

[Example 3]
Using the coating film a2 in Example 2, this coating film a2 was immersed in a 100 mM nickel acetate aqueous solution (25 ° C.) for 10 minutes, and the coating film a2 was impregnated with nickel ions to form a metal ion-containing layer a3.

A polyimide precursor resin layer b3 and a nickel deposition precursor resin layer c3 on which a resist pattern was formed in the same manner as in Example 1 except that the metal ion-containing layer a3 was used instead of the coating film a1 in Example 1. Got. The sheet resistance of the nickel deposition layer in the nickel deposition precursor resin layer c3 was 25Ω / □, and was particularly excellent as a conductive film. The nickel deposition precursor resin layer c3 is electroplated at an electric current density of ² A / dm ^{2 in} an electric copper plating bath to form a copper wiring having a copper film thickness of 10 μm, and a copper wiring forming precursor resin layer d3 was obtained, and a copper wiring-forming polyimide resin layer e3 was obtained in the same manner as in Example 1. The obtained copper wiring formation polyimide resin layer e3 was peeled from the stainless steel base material to obtain a copper wiring formation film e3 ′. The obtained copper wiring forming film e3 ′ was not warped, the peel strength of the copper wiring was 1.4 kN / m, and the adhesiveness was excellent.

[Example 4]
On a stainless steel substrate, the thickness after imidization by applying a polyimide precursor resin solution S ₁ so that 25 [mu] m, followed by drying at 130 ° C. 20 minutes to obtain a polyimide precursor resin layer. On this resin layer, the polyimide precursor nickel complex solution A was apply | coated so that the thickness after imidation might be set to 2.5 micrometers, and the coating film a4 was obtained by drying at 130 degreeC for 20 minute (s). The coating film a4 was immersed in a 25 wt% aqueous ammonia solution (25 ° C.) for 2 minutes to impregnate the coating film a4. Thereafter, the coating film a4 was pulled up from the aqueous ammonia solution, washed with water, and dried to obtain a coating film a4 ′.

A polyimide precursor resin layer b4 and a nickel deposition precursor resin layer c4 formed with a resist pattern were formed in the same manner as in Example 1 except that the coating film a4 ′ was used instead of the coating film a1 in Example 1. Obtained. The sheet resistance of the nickel deposition layer in the nickel deposition precursor resin layer c4 was 42Ω / □, and a conductive film was formed. The nickel deposition precursor resin layer c4 is subjected to electroplating in an electric copper plating bath at a current density of ² A / dm ² to form a copper wiring having a copper film thickness of 10 μm, and a copper wiring forming precursor resin layer d4 was obtained, and a copper wiring-forming polyimide resin layer e4 was obtained in the same manner as in Example 1. The obtained copper wiring formation polyimide resin layer e4 was peeled from the stainless steel base material to obtain a copper wiring formation film e4 ′. The obtained copper wiring-forming film e4 ′ had no warpage and had a copper wiring peeling strength of 1.4 kN / m, which was excellent in adhesion.

[Example 5]
Resist pattern was obtained in the same manner as in Example 1 except that it was immersed in a 25% by weight aqueous ethanolamine solution (25 ° C.) for 2 minutes instead of being immersed in the 25% by weight aqueous ammonia solution (25 ° C.) in Example 4. A polyimide precursor resin layer b5 and a nickel-deposited resin layer c5 were obtained. The sheet resistance of the nickel precipitation layer in the nickel precipitation resin layer c5 was 45Ω / □, and a conductive film was formed. The nickel-deposited resin layer c5 is electroplated at an electric current density of ² A / dm ^{2 in} an electric copper plating bath to form a copper wiring having a copper film thickness of 10 μm, and a copper wiring forming precursor resin layer d5 is formed. In the same manner as in Example 1, a copper wiring-forming polyimide resin layer e5 was obtained. The obtained copper wiring formation polyimide resin layer e5 was peeled from the stainless steel base material to obtain a copper wiring formation film e5 ′. The obtained copper wiring forming film e5 ′ had no warping, the peel strength of the copper wiring was 1.4 kN / m, and was excellent in adhesion.

[Reference example]
50 polyimide film (manufactured by Toray DuPont, trade name: Kapton EN, 100 mm × 100 mm × 25 μm thickness, linear thermal expansion coefficient (CTE) 16 × 10 ⁻⁶ / K) in 5N potassium hydroxide aqueous solution Immersion at 10 ° C. for 10 minutes. Thereafter, the immersed polyimide film is sufficiently washed with ion-exchanged water, immersed in a 1% by weight hydrochloric acid aqueous solution (25 ° C.) for 30 seconds, further sufficiently washed with ion-exchanged water, and dried by blowing compressed air. Thus, a surface-treated polyimide film was obtained. The thickness of the alkali treatment layer on one surface of this surface-treated polyimide film was 1.4 μm.

  Next, the film was immersed in a 100 mM nickel acetate aqueous solution (25 ° C.) for 10 minutes, and the alkali-treated layer was impregnated with nickel ions to form a metal ion-containing layer. Thereafter, a dry film resist (manufactured by Asahi Kasei Co., Ltd., trade name: Sunfort AQ, 10 μm thickness) is laminated on the surface of the metal ion-containing layer at a temperature of 110 ° C., and exposed to ultraviolet rays through a photomask. The resist pattern of 50 μm {wiring width / wiring interval (L / S) = 20 μm / 30 μm} was formed by developing with a weight% sodium carbonate aqueous solution to obtain a film on which the resist pattern was formed.

The film is immersed in a 50 mM aqueous solution of sodium borohydride (50 ° C.) for 3 minutes to form a nickel deposition layer on the surface of the metal ion-containing layer that is not masked by the resist layer, and an electroless nickel plating bath ( The nickel layer used as the foundation | substrate of an electrolytic copper plating was formed by making it immerse in Okuno Pharmaceutical Co., Ltd. make and brand name: Top Nicolon TOM-S for 30 seconds at 80 degreeC. Furthermore, the formed nickel layer was electroplated at a current density of ² A / dm ^{2 in} an electro copper plating bath to form a copper wiring having a copper film thickness of 10 μm. When the adhesion of the formed copper wiring was evaluated, the peel strength was 0.7 kN / m.

  The outline and test results of the tests in Examples 1 to 5 and the reference example are summarized in Tables 1 and 2.

  From Table 1 and Table 2, the copper wiring forming resin layer as the circuit wiring board manufactured by the methods of Examples 1 to 5 has a very large peeling strength of 1.4 kN / m and is flexible. It was confirmed that the adhesion required for applications such as printed wiring boards was remarkably superior even when compared with the reference examples.

  In particular, in Example 1 and Example 2 in which the polyimide resin precursor complex A was used and the surface resin layer was formed of a thermoplastic polyimide resin (Tg = 252 ° C.) having a glass transition temperature of 350 ° C. or lower, the metal The nickel particles deposited in the deposited layer forming step are embedded in the thermoplastic polyimide resin precursor layer at a sufficient depth (about 100 nm), which contributes to improved adhesion. It was thought that.

Further, a low thermal expansion polyimide resin having a linear thermal expansion coefficient in the range of 1 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K) [CTE = 14.6 × 10 ⁻⁶ (1 / K)]. In Examples 2 to 5 in which a multilayer structure is formed by laminating the thermoplastic polyimide resin above, since the thermoplastic polyimide resin is disposed in a layer adjacent to the metallic nickel layer, the above and For the same reason, it was shown that excellent adhesion can be obtained, and that the warpage of the substrate can be effectively suppressed by the laminated structure with the low thermal expansion polyimide resin.

  In Example 3 in which the metal ion in the film was increased by impregnating the coating film as the polyimide precursor resin layer with the metal ion solution, the sheet resistance of the nickel deposition layer after the reduction treatment was 25 [Ω / □. The electroplating process is still possible without performing the electroless plating process. This was thought to be because the amount of nickel ions in the coating film became abundant due to the impregnation of metal ions, and the deposited metal nickel layer could be formed into a dense film.

  Further, in Examples 4 to 5 in which the coating film as the polyimide precursor resin layer was immersed in an aqueous amine solution and impregnated with ammonia or amine, the nickel deposition layer after the reduction treatment was formed into a film shape. The sheet resistance was as small as 50 [Ω / □] or less, and the electroplating process was possible without performing the electroless plating process. This is because the amine complex formed between the metal ions in the coating film by impregnation with the aqueous amine solution has the property of easily liberating the ligand when reducing the metal ions, thereby reducing the metal ions. It was thought that this was a result of the nickel deposit layer being formed in a film shape, proceeding uniformly at the surface layer portion of the coating film.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the significance of the present invention, and such modifications are included in the scope of the present invention.

  The method of the present invention is applicable to the manufacture of circuit wiring boards such as printed wiring boards used for various electronic components.

Claims (5)

A method of manufacturing a circuit wiring board by forming circuit wiring on a polyimide resin layer,
a) A step of forming a coating film by applying a coating liquid containing a polyimide precursor resin, which is a precursor of a polyimide resin, and a metal compound on a substrate and drying the coating solution;
b) coating the surface of the coating film with a resist layer, forming a pattern and forming a resist mask;
c) a step of forming a metal deposition layer by reducing metal ions in the coating film by a wet reduction method to deposit a metal in a region not covered with the resist mask in a surface layer portion of the coating film;
d) forming a circuit wiring having a pattern by electroless plating and / or electroplating on the metal deposition layer; and e) imidizing the polyimide precursor resin layer in the coating film by heat treatment, Forming a resin layer;
And after the step c and before the step e, the polyimide precursor resin layer is immersed in a citric acid aqueous solution or an oxalic acid aqueous solution, and metal ions present in the polyimide precursor resin layer are removed. And a step of removing the circuit wiring board. A method of manufacturing a circuit wiring board by forming circuit wiring on a polyimide resin layer,
a) A step of forming a coating film by applying a coating liquid containing a polyimide precursor resin, which is a precursor of a polyimide resin, and a metal compound on a substrate and drying the coating solution;
b) coating the surface of the coating film with a resist layer, forming a pattern and forming a resist mask;
c) a step of forming a metal deposition layer by reducing metal ions in the coating film by a wet reduction method to deposit a metal in a region not covered with the resist mask in a surface layer portion of the coating film;
d) forming a circuit wiring having a pattern on the metal deposition layer by electroless plating and / or electroplating; and
e) imidizing the polyimide precursor resin layer in the coating film by heat treatment to form the polyimide resin layer;
With
After the step a), the method further comprises f) a step of increasing the content of metal ions in the coating film by impregnating the coating film with an aqueous solution containing metal ions and drying. A method of manufacturing a circuit wiring board, which is characterized. A method of manufacturing a circuit wiring board by forming circuit wiring on a polyimide resin layer,
a) A step of forming a coating film by applying a coating liquid containing a polyimide precursor resin, which is a precursor of a polyimide resin, and a metal compound on a substrate and drying the coating solution;
b) coating the surface of the coating film with a resist layer, forming a pattern and forming a resist mask;
c) a step of forming a metal deposition layer by reducing metal ions in the coating film by a wet reduction method to deposit a metal in a region not covered with the resist mask in a surface layer portion of the coating film;
d) forming a circuit wiring having a pattern on the metal deposition layer by electroless plating and / or electroplating; and
e) imidizing the polyimide precursor resin layer in the coating film by heat treatment to form the polyimide resin layer;
With
A method for producing a circuit wiring board, comprising: g) a step of impregnating the coating film with an aqueous ammonia solution or an aqueous solution of a primary or secondary amine after the step a). A method of manufacturing a circuit wiring board by forming circuit wiring on a polyimide resin layer,
a) A step of forming a coating film by applying a coating liquid containing a polyimide precursor resin, which is a precursor of a polyimide resin, and a metal compound on a substrate and drying the coating solution;
b) coating the surface of the coating film with a resist layer, forming a pattern and forming a resist mask;
c) reducing the metal ions in the coating film to deposit a metal in a region not covered with the resist mask in the surface layer portion of the coating film to form a metal deposition layer;
d) forming a circuit wiring having a pattern by electroless plating and / or electroplating on the metal deposition layer; and e) imidizing the polyimide precursor resin layer in the coating film by heat treatment, Forming a resin layer,
After the step a), f) a step of increasing the content of metal ions in the coating film by impregnating the coating film with an aqueous solution containing metal ions and drying.
A method of manufacturing a circuit wiring board, comprising: A method of manufacturing a circuit wiring board by forming circuit wiring on a polyimide resin layer,
a) A step of forming a coating film by applying a coating liquid containing a polyimide precursor resin, which is a precursor of a polyimide resin, and a metal compound on a substrate and drying the coating solution;
b) coating the surface of the coating film with a resist layer, forming a pattern and forming a resist mask;
c) reducing the metal ions in the coating film to deposit a metal in a region not covered with the resist mask in the surface layer portion of the coating film to form a metal deposition layer;
d) forming a circuit wiring having a pattern by electroless plating and / or electroplating on the metal deposition layer; and e) imidizing the polyimide precursor resin layer in the coating film by heat treatment, Forming a resin layer,
After the step a), g) a step of impregnating the coating film with an aqueous ammonia solution or an aqueous solution of a primary or secondary amine;
A method of manufacturing a circuit wiring board, comprising:

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