TWI634986B - Copper-covered laminate plate, printed circuit board and using method thereof - Google Patents

Abstract

The present invention provides a copper-clad laminated board, a printed wiring board, and a method of using the same that can cope with the reduction in frequency and high frequency of electronic equipment. The copper-clad laminated board includes a polyimide insulating layer, and a copper foil is provided on at least one side of the polyimide insulating layer. The thermal linear expansion coefficient of the polyimide insulation layer is in the range of 0 ppm / K or more and 30 ppm / K or less, according to formula (i);

On the other hand, the E ₁ value calculated as an index representing the dielectric characteristics is less than 0.009. The square average roughness (Rq) of the surface of the copper foil in contact with the polyfluorene imide insulating layer is in a range of 0.05 μm or more and less than 0.5 μm .

Description

Copper-clad laminated board, printed wiring board and use method thereof

The invention relates to a copper-clad laminated board having a polyimide insulating layer and a copper foil layer, and a printed wiring board for processing a copper circuit of the copper-clad laminated board, and a method for using the same.

In recent years, with the progress of miniaturization, weight reduction, and space saving of electronic equipment, thin and lightweight flexible printed wiring boards (FPC; Flexible Printed Circuits) having flexibility and excellent durability even after repeated bending Demand is increasing. FPC can also achieve stereo and high-density installation in a limited space. Therefore, for example, the wiring of the movable part of electronic devices such as hard disk drives (HDD), digital video discs (DVD), and mobile phones , Or cables, connectors and other parts, its use is constantly expanding.

In addition to the above-mentioned high-density, high-performance equipment has also progressed, and therefore, it is required to cope with high-frequency transmission signals. In information processing or information communication, for the transmission and processing of large-capacity information, in order to increase the transmission frequency, the printed circuit board material is required to reduce the transmission loss caused by the thinning of the insulating layer and the low dielectricity of the insulating layer. FPC using previous polyimide due to the dielectric constant of polyimide Or, the dielectric tangent is high, and the transmission loss in the high-frequency region is high. Therefore, it is difficult to cope with the high-frequency. Therefore, in order to cope with high frequency, FPCs having a liquid crystal polymer as a dielectric layer, which is characterized by a low dielectric constant and a low dielectric tangent, have been mainly used. However, although the liquid crystal polymer has excellent dielectric properties, there is room for improvement in heat resistance or adhesion to a metal foil.

In order to improve heat resistance or adhesiveness, a metal-clad laminate including polyfluorene imide as an insulating layer has been proposed (Patent Document 1). According to Patent Document 1, it is known that a dielectric constant is generally reduced by using an aliphatic monomer as a monomer of a polymer material, but a polyimide obtained by using an aliphatic (chain-like) tetracarboxylic dianhydride has heat resistance. The properties are obviously low, so it cannot be used for processing such as welding, which has practical problems. In addition, in Patent Document 1, when an alicyclic tetracarboxylic dianhydride is used, a polyimide having improved heat resistance can be obtained as compared with a linear aliphatic tetracarboxylic dianhydride. However, the dielectric constant of such a polyfluorene film at 10 GHz is 3.2 or less, but the dielectric tangent exceeds 0.01, and the dielectric characteristics are still insufficient.

In order to improve the dielectric characteristics, a copper-clad laminated board has been proposed in which the concentration of the fluorene imine group of the polyfluorene layer which is in contact with the copper foil forming the conductor circuit is controlled (Patent Document 2). According to Patent Document 2, the dielectric characteristics can be controlled by a combination of the surface roughness Rz of the copper foil and the polyimide layer having a low fluorene imine concentration on the surface in contact with the copper foil, but there is a limit to the control , Transmission characteristics can not be fully met.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-358961

[Patent Document 2] Japanese Patent No. 5031639

The present invention is to provide a copper-clad laminated board, a printed wiring board, and a method of using the same that can cope with the high-frequency increase associated with miniaturization and high performance of electronic equipment.

In order to solve the problem, the present inventors focused on the Skin Effect of copper foil and found that by using a copper foil having a specific surface state as a conductor layer and an insulating layer using a polymer having specific dielectric characteristics It is possible to obtain a circuit board such as FPC, which has excellent transmission characteristics in the high-frequency region, by using imine, thereby completing the present invention.

That is, the copper-clad laminated board according to the present invention includes a polyimide insulating layer, and a copper foil is provided on at least one side of the polyimide insulating layer. In the copper-clad laminated board according to the present invention, the polyfluorene imide insulating layer includes the following constitutions Ia and Ib: Ia) The coefficient of thermal linear expansion is in a range of 0 ppm / K or more and 30 ppm / K or less; Ib) is based on the following Equation (i),

[Here, ε ₁ represents the dielectric constant at 3 GHz by the Cavity Resonator Perturbation Method, and Tan δ ₁ represents the dielectric tangent at 3 GHz by the Cavity Resonator Perturbation Method. (Dielectric Tangent)]

The E ₁ value calculated as an index indicating the dielectric characteristics is less than 0.009; and the copper foil includes the following configuration c: c) a square average roughness of a surface in contact with the polyfluorene imide insulating layer ( Rq) is in a range of 0.05 μm or more and less than 0.5 μm .

In the copper-clad laminated board of the present invention, the dielectric constant may be 3.1 or less, and the dielectric tangent may be less than 0.005.

In the copper-clad laminated board of the present invention, an arithmetic average height (Ra) of a surface of the copper foil in contact with the polyfluorene imide insulating layer may be 0.2 μm or less.

In the copper-clad laminated board of the present invention, a ten-point average roughness (Rz) of a surface of the copper foil that is in contact with the polyfluorene imide insulating layer may be 1.5 μm or less.

In the copper-clad laminated board of the present invention, the dielectric constant of the polyfluorene imide insulating layer at 10 GHz may be 3.0 or less, and the dielectric tangent may be 0.005 or less.

The printed wiring board of the present invention is obtained by processing a copper foil of any of the copper-clad laminated boards as described above.

The method of using the printed wiring board of the present invention is preferably used in a frequency region in a range of 1 GHz to 40 GHz, and more preferably used in a frequency region in a range of 1 GHz to 20 GHz.

The copper-clad laminated board of the present invention can effectively utilize the dielectric properties of the polyimide insulation layer by suppressing the increase in resistance caused by the skin effect of the copper foil, and thus can be suitably used as an electronic material requiring high-speed signal transmission .

FIG. 1 is a graph showing the results of Example 1 and Reference Examples 1 to 3.

FIG. 2 is a graph showing the results of simulation (1) to simulation (6).

FIG. 3 is a graph showing the results of simulation (7) to simulation (12).

Hereinafter, embodiments of the present invention will be described.

<Copper clad laminate>

The copper-clad laminated board according to this embodiment is a copper-clad laminated board provided with a polyimide insulating layer and a copper foil layer provided on at least one side of the polyimide insulating layer. The single-sided copper-clad laminated board including copper foil on one side of the amine insulating layer may be a double-sided copper-clad laminated board including copper foil on both sides of the polyimide insulating layer. In addition, the double-sided copper-clad laminated board can be obtained by, for example, forming a single-sided copper-clad laminated board, and forming the polyimide insulation layers facing each other by hot pressing and crimping, or copper-clad on one side. A copper foil is laminated on the polyimide insulation layer of the laminated board, and the like is formed.

<Polyimide insulation layer>

The polyimide forming the polyimide resin layer includes so-called polyimide, and includes: polyimide, polybenzimidazole, polyimide, polyetherimide, polysiloxane A heat-resistant resin having a fluorene imine group in the structure, such as an alkylimide.

The thermal linear expansion coefficient of the polyfluorene imide insulating layer is in the range of 0 ppm / K to 30 ppm / K. By controlling within this range, warpage or reduction in dimensional stability when forming a copper-clad laminate can be suppressed. In addition, the polyimide insulating layer has a single or multiple polyimide layers, but a low thermal expansion polyimide layer is suitable as a base film layer (the main layer of the insulating resin layer). Specifically, if the thermal linear expansion coefficient is in the range of 1 × 10 ^-6 (1 / K) to 30 × 10 ^-6 (1 / K), it is preferably 1 × 10 ^-6 (1 / K) to 25 × Application of low thermal expansion polyimide layer in the range of 10 ^-6 (1 / K), more preferably in the range of 15 × 10 ^-6 (1 / K) to 25 × 10 ^-6 (1 / K) For the base film layer, a large effect can be obtained. On the other hand, a polyimide layer exceeding the thermal linear expansion coefficient is also suitable for use as an adhesive layer with a copper foil layer. Polyimide that can be suitably used as such an adhesive polyimide layer is preferably polyimide whose glass transition temperature is, for example, 350 ° C or lower, and more preferably whose glass transition temperature is in the range of 200 ° C to 320 ° C Polyimide inside.

The thickness of the polyfluorene imide insulating layer may be, for example, in a range of 6 μm to 50 μm , and preferably in a range of 9 μm to 45 μm . If the thickness of the polyimide insulation layer is less than 6 μm , there may be an abnormality such as wrinkles during transportation during the manufacture of a copper-clad laminated board. On the other hand, if the polyimide insulation layer has When the thickness exceeds 50 μm , there is a concern that problems may occur in the dimensional stability and bendability at the time of manufacturing the copper-clad laminated board. In addition, when forming a polyfluorene imide insulating layer from a plurality of polyfluorene imide layers, the total thickness may be within the above range.

(Dielectric properties)

The polyimide insulating layer is used as a whole of the insulating resin layer in order to ensure transmission characteristics in a high frequency region when used for a circuit board such as a flexible circuit board (hereinafter sometimes referred to as "FPC"). E as represented by the calculated index dielectric characteristics at 3GHz cavity resonator perturbation method _a value of less than 0.009, preferably in the range of 0.0025 to 0.007, more preferably in the range of 0.0025 to 0.006. When the value of E ₁ exceeds the upper limit, when used for a circuit board such as an FPC, an abnormality such as a loss of an electric signal is likely to occur on a transmission path of a high-frequency signal.

(Dielectric Constant and Dielectric Tangent)

Polyimide insulation layer is used to set the transmission loss of the same level as the copper-clad laminated board made of liquid crystal polymer in the 1GHz to 40GHz region when used for circuit boards such as FPC. The dielectric constant at 3GHz ( ε ₁ ) Is preferably 3.1 or less, and the dielectric tangent (Tan δ ₁ ) is preferably less than 0.005. If the dielectric constant of the polyfluorene imide layer at 3.1 GHz exceeds 3.1, and the dielectric tangent is 0.005 or more, it is easy to cause abnormalities in the loss of electrical signals when used for circuit boards such as FPC.

In addition, in order to reduce the transmission loss to a level equivalent to that of a liquid crystal polymer when the polyfluorene imide insulating layer is used in a circuit board such as an FPC, the dielectric tangent at 3 GHz is preferably less than 0.005. If the dielectric tangent of the polyfluorene imide layer at 3 GHz is 0.005 or more, when it is used in a circuit board such as an FPC, an electrical signal loss will occur in the transmission path of a high-frequency signal.

In addition, in order to reduce the transmission loss to a level equivalent to that of a liquid crystal polymer when used for a circuit board such as FPC, the polyimide insulation layer preferably has a dielectric constant at 3.0 GHz of 3.0 or less and a dielectric tangent of 0.005 or less. By controlling the dielectric characteristics of the polyfluorene imide insulation layer within such a range, transmission loss can be suppressed on the transmission path of high-frequency signals when used for circuit boards such as FPC.

From the viewpoint of the ease of controlling the thickness or physical properties of the polyimide insulation layer, it is preferable to use a so-called casting (coating) method in which a polyamic acid solution is directly coated on a copper foil and then dried and hardened by heat treatment ) Polyimide insulation layer obtained by the method. In addition, when a polyimide insulation layer is provided in multiple layers, different configurations may be included. The polyamino acid solution of the component is formed by sequentially coating another polyamino acid solution. When the polyfluorene imide insulating layer includes a plurality of layers, a polyfluorene imide precursor resin having the same constitution may be used more than twice.

In order to form a polyfluorene imide insulation layer, a polyfluorene imide is particularly suitable in which an acid anhydride component containing an aromatic tetracarboxylic anhydride and two terminal carboxylic acid groups containing a dimer acid are substituted with a primary aminomethyl group or an amino group. The polyimide obtained by reacting the dimer acid-type diamine with the diamine component of the aromatic diamine, and the dimer acid-type diamine is preferably 4 mol% relative to all the diamine components. In the range of ~ 40 mole%.

Such a polyfluorene imine is preferably a polyfluorene imine having a structural unit represented by the following general formula (1) and general formula (2).

[In the formula, Ar represents a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ represents a divalent acid diamine residue derived from a dimer acid diamine, and R ₂ represents an aromatic diamine residue. A divalent aromatic diamine residue derived from a group diamine, m and n represent the presence of mole ratio of each constituent unit, m is in the range of 0.04 to 0.4, and n is in the range of 0.6 to 0.96. ]

Examples of the group Ar include a group represented by the following formula (3) or formula (4).

[Wherein W represents a single bond, a divalent hydrocarbon group selected from 1 to 15 carbon atoms, -O-, -S-, -CO-, -SO-, -SO _2- , -NH-, or -CONH- Divalent group]

Especially from the viewpoint of reducing the polar group of polyfluoreneimide and improving the dielectric properties, the group Ar is preferably a valence of W in formula (3) or formula (4) having a single bond and a carbon number of 1 to 15 A hydrocarbon group, a group represented by -O-, -S-, -CO-, more preferably W in formula (3) or formula (4) is a single bond, a divalent hydrocarbon group having 1 to 15 carbon atoms, -CO- Represented groups.

In addition, the structural unit represented by the general formula (1) and the general formula (2) may exist in a homopolymer, and may also exist as a structural unit of a copolymer. When it is a copolymer having a plurality of constituent units, it can exist as a block copolymer or as a random copolymer.

Polyfluorene imine is generally produced by reacting an acid anhydride and a diamine. Therefore, a specific example of a polyfluorene imine is understood by explaining an acid anhydride and a diamine. In the general formulae (1) and (2), the group Ar may refer to a residue of an acid anhydride, and the groups R ₁ and R ₂ may refer to a residue of a diamine. Diamine to illustrate the preferred polyfluorene imine.

Preferred examples of the acid anhydride having a group Ar as a residue include pyromellitic anhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-diphenylfluorene. Tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride. Examples of the acid anhydride include 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 2,3,3', 4'-benzophenonetetracarboxylic dianhydride, or 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,3 ', 3,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2, 3 ', 3,4'-Diphenylethertetracarboxylic dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, 3,3 ", 4,4" -terphenyltriphenyltetracarboxylic dianhydride, 2 , 3,3 ", 4" -terephthalate dianhydride or 2,2 ", 3,3" -terephthalate dianhydride, 2,2-bis (2,3- or 3,4- Dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3,4-dicarboxyphenyl) methane dianhydride, bis (2,3- or 3,4-dicarboxyphenyl) fluorene dianhydride, 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride, 1,2,7,8-phenanthrene-tetracarboxylic dianhydride, 1,2,6,7-phenanthrene- Tetracarboxylic dianhydride or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) tetracarboxylic acid Fluoropropane 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-Dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride or 2,7-di Naphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1,4,5,8- (or 2, 3,6,7-) tetracarboxylic dianhydride, 2,3,8,9-fluorene-tetracarboxylic dianhydride, 3,4,9,10-fluorene-tetracarboxylic dianhydride, 4,5,10,11- Hydrazone-tetracarboxylic dianhydride or 5,6,11,12-fluorene-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-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-dicarboxybenzene (Oxy) diphenylmethane dianhydride and the like.

By the radicals R ₁ derived from a dimer acid type diamine bivalent dimer acid type diamine residue. The so-called dimer acid type diamine refers to the substitution of two terminal carboxylic acid groups (-COOH) of a dimer acid with a primary aminomethyl group (-CH ₂ -NH ₂ ) or an amino group (-NH ₂ ). Diamine.

Dimer acid is a known dibasic acid obtained by the intermolecular polymerization of unsaturated fatty acids. Its industrial manufacturing process has been basically standardized in the industry. Obtained from dimerization of saturated fatty acids. The main component of the dimer acid obtained industrially is a dibasic acid with a carbon number of 36 obtained by dimerizing an unsaturated fatty acid with a carbon number of 18 such as oleic acid or linoleic acid. Depending on the degree of purification, In addition, it contains any amount of monomeric acid (18 carbons), trimer acid (54 carbons), and other polymerized fatty acids with 20 to 54 carbons. In the present invention, a dimer acid is preferably used: a dimer acid whose molecular content is increased to 90% by weight or more by molecular distillation. In addition, a double bond remains after the dimerization reaction, but in the present invention, a hydrogenation reaction is further performed to reduce the degree of unsaturation is also included in the dimer acid.

As a characteristic of a dimer acid type diamine, the characteristic derived from the skeleton of a dimer acid can be provided. That is, since the dimer acid-type diamine is an aliphatic of a huge molecule having a molecular weight of about 560 to 620, it is possible to increase the molar volume of the molecule and relatively reduce the polar group of polyimide. Such a dimer acid-type diamine is considered to be characteristic of suppressing a decrease in heat resistance of polyfluorene imine and contributing to improvement of dielectric properties. In addition, since it has two freely moving hydrophobic chains of 7 to 9 carbon atoms and two chain aliphatic amino groups having a length close to 18 carbon atoms, it not only provides flexibility to polyimide, but also can Hydrazone is formed as an asymmetric chemical structure or a non-planar chemical structure, Therefore, it is considered that the dielectric constant of polyfluorene can be reduced.

The input amount of the dimer acid-type diamine may be within a range of 4 mol% to 40 mol%, preferably within a range of 4 mol% to 30 mol%, and more preferably for all the diamine components. Within the range of 4 mol% to 15 mol%. If the dimer acid-type diamine is less than 4 mol%, the dielectric properties of polyfluorene imine tend to decrease. If the dimer acid-type diamine is more than 40 mol%, there is a tendency for polyimide. A decrease in glass transition temperature tends to deteriorate heat resistance.

Commercial products can be obtained from dimer acid type diamines. Examples include PRIAMINE 1073 (trade name) manufactured by Croda Japan, the same PRIAMINE 1074 (trade name), and Cognis Japan. Versamine 551 (trade name), same as Versamine 552 (trade name), and the like.

Examples of the group R ₂ include groups represented by the following formulae (5) to (7).

[In formulas (5) to (7), R ₃ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, Z represents a single bond, a divalent hydrocarbon group selected from 1 to 15 carbon atoms, -O- , -S-, -CO-, -SO-, -SO _2- , -NH- or -CONH-, n ₁ independently represents an integer from 0 to 4]

In particular, from the viewpoint of reducing the polar group of polyfluoreneimide and improving the dielectric properties, the group R ₂ is preferably: Z in the formulae (5) to (7) is a single bond and 2 to 2 carbon atoms. A valent hydrocarbon group, R ₃ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, and n ₁ is an integer of 0 to 4.

Having a R ₂ group as the diamine residue may include, for example: 4,4'-diaminodiphenyl ether, 4,4'-diamino-2'-methoxy-benzoyl aniline, 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'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminobenzidine aniline, 2,2- Bis- [4- (3-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] fluorene, bis [4- (3-aminophenoxy) phenyl]碸, 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)] dibenzoyl Ketone, bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 '-(4-aminophenoxy)] benzidine aniline, bis [4,4'-(3 -Aminophenoxy)] benzidineaniline, 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene, 9,9-bis [4- (3-amino Phenylphenoxy) phenyl] fluorene, 2,2-bis- [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis- [4- (3-aminophenoxy ) Phenyl] hexafluoropropane, 4,4'-methylenedi-o-toluidine, 4,4'-methylenebis-2,6-dimethylaniline, 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'-diaminodiphenylsulfide, 3,3'- Diaminodiphenylsulfide, 4,4'-diaminodiphenylphosphonium, 3,3'-diaminodiphenylphosphonium, 4,4'-diaminodiphenyl ether, 3,3-diaminodiphenyl ether Phenylene 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-benzenebis (1-methylethylene) )] Bisaniline, 4,4 '-[1,3-phenylbis (1-methylethylene)] bisbenzene , Bis (p-aminocyclohexyl) methane, bis (p-amino-β- - tert-butylphenyl) ether, bis (p-methyl β- - [delta] - amino-pentyl) 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-xylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine and the like.

According to the dielectric properties of polyfluorene imine, suitable aromatic tetracarboxylic anhydrides for preparing precursors of polyfluorene imine include, for example, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) , 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3', 4,4'-diphenylphosphonium tetracarboxylic dianhydride (DSDA), pyromellitic dianhydride Anhydride (PMDA) and so on. Among them, particularly preferred anhydrides include 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA). Wait. The aromatic tetracarboxylic anhydride may be prepared by combining two or more kinds.

In addition to the acid anhydride, a siloxane tetracarboxylic dianhydride is also suitably used, and examples thereof include the siloxane tetracarboxylic dianhydride represented by the following general formula (8).

[In formula (8), R and R 'independently represent a trivalent aliphatic group or an aromatic group having 1 to 4 carbon atoms, and R ₄ to R ₇ independently represent a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, n represents an integer from 1 to 50, and the average repeat number is 1 to 20]

In addition to the acid anhydride, a siloxane tetracarboxylic dianhydride is also suitably used, and examples thereof include a siloxane tetracarboxylic dianhydride represented by the following general formula (9).

[In formula (9), R ₁₁ and R ₁₂ independently represent a divalent hydrocarbon group, R ₄ to R ₇ independently represent a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, n represents an integer of 1 to 50, and the average repeat number is 1 ~ 20]

In addition, according to the dielectric properties of polyfluorene imine, aromatic diamines suitable for preparing a precursor of polyfluorene imine include, for example, 2,2-bis (4-aminophenoxyphenyl) propane (BAPP ), 2,2'-divinyl-4,4'-diaminobiphenyl (VAB), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), 2, 2'-diethyl-4,4'-diaminobiphenyl, 2,2 ', 6,6'-tetramethyl-4,4'-diaminobiphenyl, 2,2'-diphenyl- 4,4'-diaminobiphenyl, 9,9-bis (4- Aminophenyl) fluorene and the like. Among them, particularly preferred diamine components include 2,2-bis (4-aminophenoxyphenyl) propane (BAPP), 2,2'-divinyl-4,4'-diaminobiphenyl ( VAB), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), etc. The aromatic diamine may be prepared by combining two or more kinds.

The acid anhydride and the diamine may be used alone, or two or more of them may be used in combination. In addition, other diamines and acid anhydrides not included in the general formulae (1) and (2) may be used together with the acid anhydrides or diamines. In this case, the use ratio of other acid anhydrides or diamines is preferably It is 10 mol% or less, More preferably, it is 5 mol% or less. By selecting the type of the acid anhydride and the diamine, or the mole ratios when two or more kinds of the acid anhydride or the diamine are used, the thermal expansion property, adhesiveness, glass transition temperature, and the like can be controlled.

The polyfluorene imide having a structural unit represented by the general formula (1) and the general formula (2) can be produced by making the aromatic tetracarboxylic anhydride, a dimer acid-type diamine, and an aromatic diamine The reaction is performed in a solvent, and a precursor resin is generated, followed by heating and ring closure. For example, an acid anhydride component and a diamine component are dissolved in an organic solvent at approximately equal moles, and the polymerization reaction is performed by stirring at a temperature in a range of 0 ° C to 100 ° C for 30 minutes to 24 hours, thereby obtaining polyimide. Precursor Polyamic Acid. During the reaction, the produced precursor dissolves the reaction component in an organic solvent in a range of 5 to 30% by weight, preferably in a range of 10 to 20% by weight. Examples of the organic solvent used in the polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone, 2-butanone, Dimethyl sulfene, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether, Triethylene glycol dimethyl ether and the like. These solvents may be used in combination of two or more kinds thereof, and aromatic hydrocarbons such as xylene and toluene may also be used in combination. In addition, the use amount of such an organic solvent is not particularly limited, and it is preferable to adjust the concentration of the polyamidic acid solution (polyimide precursor solution) obtained by the polymerization reaction to, for example, about 5% to 30% by weight. The amount of use.

The synthesized precursor is generally advantageously used as a reaction solvent solution, but can be concentrated, diluted or replaced with other organic solvents as needed. In addition, the precursor is generally excellent in solvent solubility, and thus can be favorably used. The method of subjecting the precursor to ammonium imidization is not particularly limited, and for example, it is suitable to adopt a heat treatment in the solvent at a temperature in a range of 80 ° C. to 400 ° C. for 1 hour to 24 hours.

The polyimide insulating layer may contain an inorganic filler in the polyimide layer as necessary. Specific examples include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, and calcium fluoride. The said inorganic filler can be used individually by 1 type or in mixture of 2 or more types.

<Copper foil>

In the copper-clad laminated board of this embodiment, the square average roughness (Rq) of the surface where the copper foil contacts the polyimide insulation layer is 0.05 μm or more and less than 0.5 μm , and may preferably be 0.1 μ m or more, in the range of 0.4 μ m or less. The square average roughness (Rq) defined here is a square average roughness according to JIS B0601: 2001. The material of the copper foil may be a copper alloy.

If the copper foil used in the copper-clad laminated board of this embodiment satisfies The characteristics are not particularly limited, and a commercially available copper foil can be used. As specific examples thereof, rolled copper foils include BHY-22B-T (trade name) manufactured by JX Nippon Nissei Metal Co., Ltd., and the same as GHY5-93F-T (trade name). The electrolytic copper foils include: F1-WS (trade name) manufactured by Furukawa Electric Industry Co., Ltd., HLS (trade name) manufactured by Japan Electrolytic Co., Ltd., same HLS-2 (trade name), same HLB (trade name), JX Nippon Steel AMFN (trade name) manufactured by Shimetal Co., Ltd.

In a state where a high-frequency signal is supplied to a signal wiring, there is a problem (skin effect): a current flows only on the surface of the signal wiring, an effective cross-sectional area of the current flow decreases, a DC resistance increases, and a signal is attenuated. By reducing the surface roughness of the surface of the copper foil in contact with the polyimide insulation layer, it is possible to suppress an increase in the resistance of the signal wiring due to the skin effect. However, if the surface roughness is reduced in order to meet the standard of electrical performance requirements, the adhesion (peel strength) between the copper foil and the polyimide insulation layer becomes weak. Therefore, it is important to control the square average roughness (Rq) as a parameter of the surface roughness from the viewpoint of meeting the electrical performance requirements and ensuring the adhesion to the polyimide insulation layer. That is, it is estimated from the results of the simulation test described later that the square average roughness (Rq) more accurately reflects the fine unevenness on the surface of the copper foil on the surface of the copper foil due to the skin effect than other indicators of surface roughness. The effect of the current. Therefore, as an index of the surface roughness of the surface of the copper foil in contact with the polyimide insulation layer, the square average roughness (Rq) is used, and the square average roughness (Rq) is defined within the range. , And can simultaneously satisfy the existence of the adhesion with the polyimide insulation layer and the suppression of the increase in resistance to the wiring Eclectic requirements.

The surface roughness of the surface of the copper foil that is in contact with the insulating resin layer is preferably an arithmetic mean height Ra of 0.2 μm or less, and preferably a ten-point average roughness Rz of 1.5 μm or less.

<Printed wiring board>

The printed wiring board of this embodiment can form a wiring layer by processing the copper foil of this copper-clad laminated board of this embodiment into a pattern by a conventional method, and can manufacture the printed wiring board which is one embodiment of this invention.

Hereinafter, the case of a casting method is given as an example, and the manufacturing method of the printed wiring board of this embodiment is demonstrated concretely.

First, the method for manufacturing a copper-clad laminated board may include the following steps (1) to (3).

step 1):

Step (1) is a step of obtaining a polyamic acid resin solution that is a precursor of the polyamidine used in the present embodiment.

Step (2):

Step (2) is a step of applying a polyamic acid resin solution on a copper foil to form a coating film. The copper foil can be used in a shape such as a slice shape, a roll shape, or an endless belt shape. In order to obtain productivity, it is effective to form a roll shape or an endless belt shape, and to provide a form capable of continuous production. In addition, from the viewpoint of exhibiting a greater effect of improving the accuracy of a wiring pattern in a printed wiring board, the copper foil is preferably formed as a long rolled copper foil.

The method for forming a coating film can be obtained by directly It is formed after being coated on a copper foil and then dried. The coating method is not particularly limited, and for example, coating can be performed by a coater such as a comma, a mold, a knife, or a lip.

The polyimide layer may be a single layer or may include a plurality of layers. When a polyimide layer is formed in multiple layers, it can be formed by sequentially coating other precursors on a layer containing precursors having different constituent components. When the precursor layer includes three or more layers, a precursor having the same configuration may be used twice or more. A two-layer or single-layer having a simple layer structure is industrially advantageous, and is therefore preferred. The thickness of the precursor layer (after drying) may be, for example, in a range of 3 μm to 100 μm , and preferably in a range of 3 μm to 50 μm .

When a polyimide layer is multilayered, it is preferable to form a precursor layer so that the polyimide layer which contacts a copper foil becomes a thermoplastic polyimide layer. By using thermoplastic polyfluorene imide, the adhesion to copper foil can be improved. The glass transition temperature (Tg) of such a thermoplastic polyimide is preferably 360 ° C or lower, and more preferably 200 ° C to 320 ° C.

In addition, a layer of a single-layer or multi-layer precursor is temporarily imidized and produced. After forming a single-layer or multiple-layer polyimide layer, a precursor layer may be further formed thereon.

Step (3):

Step (3) is a step of forming a polyfluorene imide insulating layer by heat-treating the coating film and then performing fluorimidization. The method of imidization is not particularly limited. For example, it is suitable to adopt a range of 1 minute to 60 minutes under a temperature range of 80 ° C to 400 ° C. Heat treatment within the range of time. In order to suppress the oxidation of the metal layer, heat treatment in a low oxygen environment is preferred, and specifically, it is preferably performed in an inert gas environment such as nitrogen or a rare gas, a reducing gas environment such as hydrogen, or in a vacuum. The polyimide in the coating film is imidized by heat treatment to form a polyimide.

As described above, a copper-clad laminated board having a polyimide layer (single layer or multiple layers) and a copper foil can be manufactured.

In addition, the method for manufacturing a circuit board may further include the following step (4) in addition to the steps (1) to (3).

Step (4):

Step (4) is a step of patterning the copper foil of the copper-clad laminated board to form a wiring layer. In this step, a pattern is formed by etching a copper foil into a specific shape, and a printed wiring board is obtained by processing into a wiring layer. The etching can be performed by, for example, an arbitrary method using a photolithography technique.

In the above description, only the characteristic steps of the method for manufacturing a printed wiring board have been described. That is, when manufacturing a printed wiring board, steps other than the above, such as through-hole processing in the previous step, or terminal plating and external shape processing in the subsequent step, can be performed according to a conventional method.

As described above, by using the polyfluorene imide insulating layer and copper foil of this embodiment, a copper-clad laminated board having excellent transmission characteristics can be formed. In addition, by using the polyfluorene imide insulating layer and the copper foil of this embodiment, in a circuit board typified by FPC, it is possible to improve electrical signal transmission characteristics and improve reliability.

[Example]

Examples are given below to describe the features of the present invention more specifically. However, the scope of the present invention is not limited to the examples. In the following examples, unless otherwise specified, various measurements and evaluations are based on the following.

[Measurement of Coefficient of Thermal Expansion (CTE)]

The thermal expansion coefficient is a thermomechanical analyzer (manufactured by Bruker, trade name: 4000SA), while applying a load of 5.0g, the polyimide film having a size of 3mm × 20mm is increased from 30 ° C. at a constant temperature increase rate. The temperature was raised to 250 ° C, and the temperature was maintained at the temperature for 10 minutes, and then cooled at a rate of 5 ° C / min to obtain an average thermal expansion coefficient (linear thermal expansion coefficient) from 240 ° C to 100 ° C.

[Measurement of glass transition temperature (Tg)]

The glass transition temperature was measured using a viscoelasticity measuring device (DMA: manufactured by TA Instruments, trade name; RSA3) at a temperature rise rate of 4 ° C / min and a frequency of 1 Hz. The temperature of the amine film was raised from 30 ° C to 400 ° C, and the temperature at which the change in the elastic modulus became the maximum (tan δ change rate was the largest) was evaluated as the glass transition temperature.

[Measurement of peel strength]

The peeling strength was measured by using a TENSILON tester (manufactured by Toyo Seiki Seisakusho, trade name; STROGRAPH VE-10) with a resin layer side of a sample (including a substrate / resin layer laminate) having a width of 1 mm The double-sided tape was fixed to an aluminum plate, and the force when peeling the resin layer from the substrate at a speed of 50 mm / min in the 180 ° direction was determined.

[Determination of dielectric constant and dielectric tangent]

The dielectric constant and dielectric tangent are evaluated using the cavity resonator perturbation method. The device (manufactured by Agilent Corporation, trade name; Vector Network Analyzer E8363B) measures the dielectric constant and dielectric tangent of a resin sheet (cured resin sheet) at a specific frequency. In addition, the resin sheet used for the measurement was a resin sheet left for 24 hours under conditions of a temperature of 24 ° C. to 26 ° C. and a humidity of 45% to 55%.

[Measurement of surface roughness of copper foil]

1) Measurement of square average roughness (Rq)

A stylus-type surface roughness meter (manufactured by Kosaka Research Institute, trade name; Surfcorder ET-3000) was used to determine the measurement conditions of force; 100 μ N, speed; 20 μ m, range; 800 μ m Out. The surface roughness is calculated by a method according to JIS-B0601: 2001.

2) Determination of arithmetic mean height (Ra)

A stylus-type surface roughness meter (manufactured by Kosaka Research Institute, trade name; Surfcorder ET-3000) was used to determine the measurement conditions under force: 100 μ N, speed; 20 μ m, range; 800 μ m Out. The calculation of the surface roughness is performed by a method according to JIS-B0601: 1994.

3) Determination of ten-point average roughness (Rz)

A stylus-type surface roughness meter (manufactured by Kosaka Research Institute, trade name; Surfcorder ET-3000) was used to determine the measurement conditions of force; 100 μ N, speed; 20 μ m, range; 800 μ m Out. The calculation of the surface roughness is performed by a method according to JIS-B0601: 1994.

[Evaluation of transmission characteristics]

Evaluation of transmission characteristics is performed by performing circuit processing on a copper-clad laminated board and electrically applying a microstrip line having a characteristic impedance of 50 Ω. Evaluation samples for circuit processing evaluate the transmission characteristics of the circuit processed side (transmission line side). A vector network analyzer calibrated by the SHORT-OPEN-LOAD-Thru (SOLT) method was used to measure the S parameter in a specific frequency region, and the evaluation was performed using S21 (insertion loss).

The abbreviations used in the examples and comparative examples indicate the following compounds.

(A) Polyimide raw material

DDA: Dimer acid type diamine (manufactured by Japan Heda Co., Ltd., trade name; PRIAMINE 1074, carbon number; 36, amine value; 205 mgKOH / g, content of dimer component; 95% by weight or more)

m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl

BAPP: 2,2-bis (4-aminophenoxyphenyl) propane

TPE-R: 1,3-bis (4-aminophenoxy) benzene

Wandamin: 4,4'-diaminodicyclohexylmethane

BAFL: 9,9-bis (4-aminophenyl) fluorene

TFMB: 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl

PMDA: pyromellitic dianhydride

BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride

DMAc: N, N-dimethylacetamide

(B) Copper foil

Copper foil (1): (electrolytic copper foil, thickness; 12 μm , surface roughness Rq on the resin laminate side; 0.14 μm , Rz; 0.64 μm , Ra; 0.10 μm )

Copper foil (2): (electrolytic copper foil, thickness; 12 μm , surface roughness Rq on the resin laminate side; 0.19 μm , Rz; 1.06 μm , Ra; 0.16 μm )

Copper foil (3): (electrolytic copper foil, thickness; 12 μm , surface roughness Rq on the resin laminate side; 0.27 μm , Rz; 1.36 μm , Ra; 0.21 μm )

Copper foil (4): (electrolytic copper foil, thickness; 12 μm , surface roughness Rq on the resin laminate side; 0.35 μm , Rz; 1.51 μm , Ra; 0.28 μm )

Copper foil (5): (electrolytic copper foil, thickness; 12 μm , surface roughness Rq on the resin laminate side; 0.5 μm , Rz; 1.65 μm , Ra; 0.36 μm )

Copper foil (6): (rolled copper foil, thickness; 12 μm , surface roughness Rq on the resin laminate side; 0.24 μm , Rz; 1.30 μm , Ra; 0.18 μm )

Synthesis Example 1

Under a nitrogen stream, 2.196 g of DDA (0.0041 mol), 16.367 g of m-TB (0.0771 mol), and 212.5 g of DMAc were put into a separable flask of 300 ml, and stirred and dissolved at room temperature. Next, 4.776 g of BPDA (0.0162 mol) and 14.161 g of PMDA (0.0649 mol) were added, and the mixture was stirred at room temperature for 3 hours to perform a polymerization reaction to obtain a polyamic acid solution a. The solution viscosity of the polyamic acid solution a was 26,000 cps.

Synthesis Example 2 to Synthesis Example 13

A polyamic acid solution b to a polyamino acid solution m were prepared in the same manner as in Synthesis Example 1 except that the raw material compositions shown in Tables 1 and 2 were used.

[Production example 1]

On one side (surface roughness Rz; 2.1 μm ) of the electrolytic copper foil having a thickness of 18 μm , the polymer prepared in Synthesis Example 1 was uniformly coated so that the thickness after curing was about 25 μm . After the sulfamic acid solution a, the solvent was removed by heating and drying at 120 ° C. Next, stepwise heat treatment was performed from 120 ° C to 360 ° C to complete the imidization. The obtained metal-clad laminate was subjected to etching to remove a copper foil using an aqueous solution of ferric chloride to obtain a polyfluorene film 1. The polyimide constituting the polyimide film 1 is non-thermoplastic.

The thermal expansion coefficient, glass transition temperature, dielectric constant, and dielectric tangent of the polyfluoreneimide film 1 were obtained. Each measurement result is shown in Table 3.

[Production example 2 to production example 6]

A polyimide film 2 to a polyimide film 6 of Production Example 2 to Production Example 6 were obtained in the same manner as in Production Example 1 except that the polyamic acid solution shown in Table 3 was used. The thermal expansion coefficient (CTE), glass transition temperature, dielectric constant, and dielectric tangent of the obtained polyfluoreneimide film 2 to polyaminium film 6 were obtained. Each measurement result is shown in Table 3.

The results of Production Examples 1 to 6 are collectively shown in Table 3.

[table 3]

[Production Example 7]

In the electrolytic copper foil having a thickness of 12 μ m on one surface; acid polyamide, the thickness after curing was about 2 μ m ~ 3 μ m fashion, uniformly coated (surface roughness Rz 1.39 μ m) After the solution h, stepwise heat treatment was performed from 85 ° C to 110 ° C, followed by drying to remove the solvent. Next, the polyamic acid solution b was uniformly applied so that the thickness after curing was about 42 μm to 46 μm , and the solvent was removed stepwise from 85 ° C. to 110 ° C. to remove the solvent. . Next, the polyamic acid solution h was uniformly applied so that the thickness after curing was about 2 μm to 3 μm , and then stepwise heat treatment was performed from 85 ° C. to 110 ° C. to remove Solvent. In this way, after forming three polyamidic acid layers, stepwise heat treatment was performed from 120 ° C to 320 ° C to complete the imidization to obtain a metal-clad laminate 7. A copper foil was removed from the obtained metal-clad laminate 7 by etching with an aqueous solution of ferric chloride to obtain a polyimide film 7 having a thickness of about 50 μm . The dielectric constant ( ε ₁ ) and dielectric tangent (Tan δ ₁ ) of the obtained polyfluoreneimide film 7 at 3 GHz were 3.06 and 0.0029 (E ₁ = 0.0051), and the dielectric constant and dielectric tangent at 10 GHz They are 2.86 and 0.0036.

[Example 1]

On the copper foil 2, a polyamic acid solution h was uniformly applied so that the thickness after curing was about 2 μm to 3 μm , and then stepwise heat treatment was performed from 85 ° C to 110 ° C. Dry to remove the solvent. Next, the polyamic acid solution b was uniformly applied so that the thickness after curing was about 42 μm to 46 μm , and the solvent was removed stepwise from 85 ° C. to 110 ° C. to remove the solvent. . Next, the way in which the thickness after curing was about 2 μ m ~ 3 μ m, the uniformly coated polyamide acid solution H, for up to a stepwise heat treatment is from 110 ℃ 85 ℃, removed Solvent. In this way, after forming three polyamidic acid layers, stepwise heat treatment was performed from 120 ° C. to 320 ° C. to complete the imidization to obtain a copper clad laminate 1 ′. On the polyimide insulation layer side of the obtained copper-clad laminated board 1 ', a copper foil 1 was superimposed, and thermocompression-bonded under conditions of a temperature of 380 ° C and a pressure of 6.7 MPa for 15 minutes to obtain a copper-clad laminated board 1. In the obtained copper-clad laminated board 1, the peel strength of the copper foil 1 on the thermocompression bonding side and the polyimide insulation layer was 0.96 kN / m. The copper foil 1 side was used as a ground plane, the copper foil 2 side was used as a signal plane, and circuit processing was performed, and transmission characteristics were evaluated. The results are shown in FIG. 1.

[Reference Example 1]

In a commercially available liquid crystal polymer film (thickness; 50 μ m) thermocompression bonding copper foil on both sides of the laminate 4. The copper foil on both sides of the multilayer board was used as a ground plane and a signal plane to perform circuit processing, and the transmission characteristics were evaluated. The results are shown in FIG. 1.

[Reference Example 2]

A laminate of a commercially available liquid crystal polymer film 2 (thickness: 50 μm ) on both sides of a copper foil 5 by thermal compression bonding was obtained. The copper foil on both sides of the multilayer board was used as a ground plane and a signal plane to perform circuit processing, and the transmission characteristics were evaluated. The results are shown in FIG. 1.

[Reference Example 3]

A commercially available polyimide film having a thickness of 50 μm (dielectric constant at 3 GHz; dielectric tangent at> 3.1 and 3 GHz;> 0.005) was obtained by laminating both sides of a copper foil 5 by thermocompression bonding. The copper foil on both sides of the multilayer board was used as a ground plane and a signal plane to perform circuit processing, and the transmission characteristics were evaluated. The results are shown in FIG. 1.

The results of Example 1, Reference Example 1 to Reference Example 3 are shown in FIG. 1. According to FIG. 1, it is confirmed that, in the comparison between Example 1 and Reference Example 1, the transmission characteristics in the frequency region of 1 GHz to 20 GHz are more than equal.

[Example 2]

On the copper foil 3, the polyamic acid solution h was uniformly applied so that the thickness after curing was about 2 μm to 3 μm , and then the heating was performed stepwise from 85 ° C to 110 ° C. Dry to remove the solvent. Next, the polyamic acid solution b was uniformly applied so that the thickness after curing was about 42 μm to 46 μm , and the solvent was removed stepwise from 85 ° C. to 110 ° C. to remove the solvent. . Next, the polyamic acid solution h was uniformly applied so that the thickness after curing was about 2 μm to 3 μm , and then stepwise heat treatment was performed from 85 ° C. to 110 ° C. to remove Solvent. In this way, after forming three polyamidic acid layers, stepwise heat treatment was performed from 120 ° C. to 320 ° C. to complete the imidization to obtain a copper-clad laminated board 2 ′. On the polyimide insulation layer side of the obtained copper-clad laminated board 2 ', a copper foil 1 was superposed, and thermocompression-bonded under conditions of a temperature of 380 ° C and a pressure of 6.7 MPa for 15 minutes to obtain a copper-clad laminated board 2. In the obtained copper-clad laminated board 2, the peel strength of the copper foil 1 on the thermocompression bonding side and the polyimide insulation layer was 0.96 kN / m. The copper foil 3 side was used as a ground plane, the copper foil 1 side was used as a signal plane, and circuit processing was performed, and transmission characteristics were evaluated. The results are shown in FIG. 2.

[Example 3]

In the same manner as in Example 2, a copper-clad laminated board 3 was obtained. The copper foil 1 side was set as a ground plane, and the copper foil 3 side was set as a signal plane, circuit processing was performed, and transmission characteristics were evaluated. The results are shown in FIG. 2.

[Simulation test]

Next, the results of a simulation test that confirmed the effects of the present invention will be described. The dielectric constant and dielectric tangent of the polyfluorene imide insulating layer at 3 GHz were fixed to 3.0 and 0.003, respectively. The results when Rq was changed from 0 to 1.0 are shown in FIG. 2. In addition, the dielectric constant and dielectric tangent of the polyfluorene imide insulation layer at 3 GHz were fixed to 3.4 and 0.006, respectively, and the results when Rq was changed from 0 to 1.0 are shown in FIG. 3. In the simulation test, the Rq of the ground plane and the signal plane were set to be the same.

Simulation (1) and simulation (7): Rq = 0 μ m

Simulation (2) and simulation (8): Rq = 0.1 μ m

Simulation (3) and simulation (9): Rq = 0.2 μ m

Simulation (4) and simulation (10): Rq = 0.3 μm

Simulation (5) and simulation (11): Rq = 0.5 μ m

Simulation (6) and simulation (12): Rq = 1.0 μm

The results of Example 2 and Example 3, simulation (1) to simulation (6) are shown in FIG. 2, and the results of simulation (7) to simulation (12) are shown in FIG. 3. According to FIG. 2 confirmed that, with respect Rq embodiments less than 0.5 μ m 2, and Example 3, the simulation (1) to the simulation (. 4), Rq of not less than 0.5 μ m emulation (5) and simulation (6), Large transmission loss. In addition, it was confirmed from FIG. 3 that the smaller the value of Rq, the better the transmission characteristics basically due to the proportional relationship. According to FIG. 2, a slight difference was confirmed between simulation (4) and simulation (5). . Therefore, it is considered that there is a multiplier effect between the dielectric characteristics of the polyimide insulation layer and the surface roughness Rq of the copper foil.

As mentioned above, although the embodiment of this invention was described in detail for illustration, this invention is not limited to the said embodiment, and various deformation | transformation are possible.

Claims (8)

A copper-clad laminated board includes a polyimide insulating layer, a copper foil is provided on at least one side of the polyimide insulating layer, and the polyimide insulating layer includes: Ib: Ia) The coefficient of thermal linear expansion is in the range of 0 ppm / K or more and 30 ppm / K or less; Ib) The value of E ₁ calculated as the index showing the dielectric characteristics according to the following formula (i) is less than 0.009; Here, ε ₁ represents the dielectric constant by 3GHz cavity resonator perturbation method, Tan δ ₁ represented by at 3GHz a dielectric cavity resonator perturbation method tangent; moreover, the copper foil It has the following configuration c: c) The square average roughness Rq of the surface in contact with the polyfluorene imide insulating layer is in a range of 0.05 μm or more and less than 0.5 μm. The copper-clad laminated board according to item 1 of the scope of the patent application, wherein the dielectric constant at 3 GHz is 3.1 or less, and the dielectric tangent at 3 GHz is less than 0.005. The copper-clad laminated board according to item 1 or item 2 of the scope of the patent application, wherein the arithmetic average height Ra of the surface of the copper foil that is in contact with the polyimide insulation layer is 0.2 μm or less. The copper-clad laminated board according to item 1 or item 2 of the patent application scope, wherein a ten-point average roughness Rz of a surface of the copper foil that is in contact with the polyimide insulation layer is 1.5 μm or less. The copper-clad laminated board according to item 1 or item 2 of the scope of the patent application, wherein the dielectric constant of the polyfluorene imide layer at 10 GHz is 3.0 or less, and the dielectric tangent is 0.005 or less. A printed wiring board is produced by processing a copper foil of a copper-clad laminated board according to any one of claims 1 to 5 of the scope of patent application for wiring circuits. A method for using a printed wiring board is to use the printed wiring board according to item 6 of the patent application scope in a frequency region in the range of 1 GHz to 40 GHz. A method for using a printed wiring board is to use the printed wiring board according to item 6 of the patent application scope in a frequency region in the range of 1 GHz to 20 GHz.