TW202225269A - Resin composition,adhesive film, laminate, coverlay film, copper foil with resin, metal-crad laminate and circuit board - Google Patents

Abstract

The present invention provides a resin composition which uses polyimide to form an insulating resin layer having excellent peel strength with a metal layer and excellent solder heat resistance without impairing dielectric properties. The resin composition contains: (A) a polyimide obtained by reacting a tetracarboxylic anhydride component and a diamine component; and (B) a magnesium oxide filler having an average particle diameter of 30 nm to 10 [mu]m, and with respect to the total amount of (A) component and (B) component, the content of (B) component is in the range of 1 to 50 weight%. The filler-containing thermoplastic resin layer obtained by forming the resin composition into a film, after being dehumidified under constant temperature and humidity conditions of 23 DEG C and 50% RH for 24 hours, the electrical loss tangent (Tan[delta]) as measured by split post dielectric resonator (SPDR) at 10 GHz is preferably 0.0022 or less.

Description

Resin composition, resin film, laminate, coverlay, copper foil with resin, metal-clad laminate, and circuit board

The present invention relates to a resin composition, a resin film, a laminate, a coverlay, a copper foil with resin, a metal-clad laminate, and a circuit board useful as an adhesive in circuit boards such as printed wiring boards.

In recent years, with the development of miniaturization, weight reduction, and space saving of electronic equipment, flexible printed circuit boards (FPCs) that are thin, lightweight, flexible, and have excellent durability even when repeatedly bent have been developed. Demand increases. FPC can realize three-dimensional and high-density mounting even in a limited space, so its use is expanding to wiring of movable parts of electronic equipment such as hard disk drives, digital discs, and mobile phones, or parts such as cables and connectors. .

In addition to the above-mentioned densification, the performance of equipment is also progressing, so it is also necessary to cope with the increase in the frequency of transmission signals. In information processing or information communication, in order to transmit and process large-capacity information, efforts have been made to increase the transmission frequency, and the printed circuit board material is required to reduce transmission loss by thinning the insulating layer and improving the dielectric properties of the insulating layer. In the future, FPC or adhesives that can cope with higher frequencies will be sought, and it will be important to reduce transmission loss. Regarding the improvement of the dielectric properties of the printed circuit board material, a resin composition of spherical silica surface-treated with a surface-treating agent having a polymerizable unsaturated bond is formulated into an ethylene-propylene-diene copolymer. (For example, Patent Document 1).

In addition, polyimide is commonly used as a material for printed circuit boards to form an insulating resin layer including an adhesive layer, and it has also been proposed to formulate scaly talc in a polyimide resin composition used as an adhesive for cover films. (For example, Patent Document 2). In addition, although it does not relate to a printed circuit board material, it is proposed to add first particles with an average particle diameter of 50 μm to 150 μm and second particles with an average particle diameter of 1 μm or more and less than 50 μm in the thermoplastic resin composition. The material of the first and second particles is a flame retardant of magnesium oxide (for example, Patent Document 3). However, in Patent Document 3, magnesium oxide particles are added in order to improve the flame retardancy of the resin molded product, and it is not envisaged to be used as a printed circuit board material such as FPC capable of high-frequency signal transmission. Moreover, in the examples disclosed as specific, only the application in acrylic resins is studied. [Prior Art Literature]

[Patent Literature] [Patent Document 1] International Publication WO2016/026927 [Patent Document 2] Japanese Patent No. 5777944 [Patent Document 3] Japanese Patent Laid-Open No. 2019-127558 [Patent Document 4] Japanese Patent Laid-Open No. 2017-137375

[Problems to be Solved by Invention]

Generally speaking, when a filler is blended into an insulating resin layer, there is a tendency that the adhesiveness with the metal layer or other insulating resin layers is weakened. In circuit boards such as FPCs, when the adhesiveness between the insulating resin layer and the wiring layer is low, there is a fear that the reliability of the circuit board is lowered due to the occurrence of misalignment and peeling of the wiring, and the like. Therefore, in the circuit board, it is very important to maintain the adhesion between the insulating resin layer and the wiring layer, and it is required to ensure the peel strength with the metal layer and the solder heat resistance.

Therefore, an object of the present invention is to provide a resin composition using polyimide, which can form an insulating resin layer excellent in peel strength from a metal layer and solder heat resistance without impairing dielectric properties. [Technical means to solve the problem]

The resin composition of the present invention contains the following (A) components and (B) components: (A) a polyimide obtained by reacting a tetracarboxylic anhydride component and a diamine component; (B) a magnesium oxide filler having an average particle size in the range of 30 nm to 10 μm, However, content of the said (B) component exists in the range of 1 to 50weight% with respect to the total amount of the said (A) component and the said (B) component.

In the resin composition of the present invention, the magnesium oxide filler may contain 95.0% by weight or more of magnesium oxide.

In the resin composition of the present invention, when the magnesium oxide filler is heated from 30°C to 450°C at a heating rate of 10°C per minute in thermogravimetric analysis, the weight reduction rate at 350°C may be 2% or less .

In the resin composition of the present invention, the magnesium oxide filler may be a filler whose peak derived from magnesium hydroxide is not detected in X-ray diffraction measurement.

The resin composition of the present invention may include: the diamine component contains 40 mol% or more of aliphatic diamine relative to all the diamine components, and the magnesium oxide filler has an average particle size of 200 nm to 10 μm In the range.

The resin composition of the present invention can be as follows: the aliphatic diamine is a dimer with the two terminal carboxylic acid groups of the dimer acid substituted with a primary aminomethyl group or an amino group as a dimer diamine as the main component. Diamine composition.

The resin composition of the present invention may further contain an amino compound having at least two primary amino groups as functional groups.

The resin film of the present invention is a resin film including a filler-containing thermoplastic resin layer formed of the resin composition.

In the resin film of the present invention, after the thermoplastic resin layer containing filler is conditioned for 24 hours under the constant temperature and humidity conditions of 23°C and 50% RH, the measured value is measured by a split post dielectric resonators (SPDR). The dielectric loss tangent (Tanδ) at 10 GHz can be 0.0022 or less.

The laminate of the present invention includes a substrate, and a laminate of an adhesive layer laminated on at least one surface of the substrate, wherein the adhesive layer includes the resin film.

The coverlay film of the present invention includes a coverlay film material layer, and an adhesive layer laminated on the coverlay film material layer, wherein the adhesive layer includes the resin film.

The resin-coated copper foil of the present invention is a resin-coated copper foil obtained by laminating an adhesive layer and a copper foil, wherein the adhesive layer includes the resin film.

The metal-clad laminate of the present invention includes an insulating resin layer, and a metal-clad laminate having a metal layer laminated on at least one surface of the insulating resin layer, wherein at least one layer of the insulating resin layer includes the resin film.

The circuit board of the present invention is obtained by performing wiring processing on the metal layer of the metal-clad laminate. [Effect of invention]

The resin composition of the present invention contains a polyimide and a magnesium oxide filler having an average particle size in the range of 30 nm to 10 μm, so that it is possible to form a practically sufficient solder heat resistance while maintaining a low dielectric loss tangent A resin film with excellent adhesion and peel strength. Therefore, the resin composition and resin film of the present invention can be particularly preferably used as a circuit board material such as FPC in electronic equipment requiring high-speed signal transmission, for example.

Hereinafter, embodiments of the present invention will be described. [resin composition]

The resin composition of one embodiment of the present invention contains the following (A) components and (B) components; (A) a polyimide obtained by reacting a tetracarboxylic anhydride component and a diamine component; and (B) A magnesium oxide filler having an average particle diameter in the range of 30 nm to 10 μm. <Component (A): Polyimide>

The polyimide as the component (A) contains a tetracarboxylic acid residue and a diamine residue. Moreover, in this invention, a tetracarboxylic-acid residue means the tetravalent group derived from tetracarboxylic dianhydride, and the diamine residue means the divalent group derived from a diamine compound. When the tetracarboxylic acid anhydride and the diamine compound as raw materials are reacted at approximately equal molar ratios, the molar ratio of the tetracarboxylic acid residue and the diamine residue contained in the polyimide and the molar ratio of the raw material can be adjusted. The type roughly corresponds to the molar ratio.

Further, when referred to as "polyimide" in the present invention, it refers to polyimide, polyetherimide, polyesterimide, polysiloxaneimide, in addition to polyimide Resins containing a polymer having an imide group in its molecular structure, such as imine and polybenzimidazole imide.

The polyimide as the component (A) may be thermoplastic polyimide or non-thermoplastic polyimide, but is preferably thermoplastic polyimide, and more preferably is a combination of tetracarboxylic anhydride component and 40 A solvent-soluble thermoplastic polyimide obtained by reacting a diamine component of an aliphatic diamine in an amount of mol % or more and imidizing a polyamic acid as a precursor. In addition, the term "thermoplastic polyimide" generally refers to a polyimide which is softened by heating and solidified by cooling, the above process can be repeated, and the glass transition temperature (Tg) can be clearly confirmed, but in the present invention In, it means the polyimide whose Tg can be confirmed clearly in the temperature range of less than 150 degreeC. In addition, from the viewpoint of thermocompression bonding properties at low temperatures, a polyimide whose Tg can be clearly confirmed in a temperature range of less than 100° C. is preferably used, and a dynamic viscoelasticity measuring device (dynamic mechanical analyzer) is more preferably used. (DMA)) is a polyimide having a storage elastic modulus at 30°C of 1.0×10 ⁸ Pa or more and a storage elastic modulus at Tg+30°C of less than 1.0×10 ⁷ Pa. In addition, the term "non-thermoplastic polyimide" generally refers to a polyimide that does not show softening and adhesiveness even when heated, but in the present invention, it refers to measurement using a dynamic viscoelasticity measuring device (DMA). It is a polyimide having a storage elastic modulus at 30°C of 1.0×10 ⁹ Pa or more and a storage elastic modulus at 300°C of 3.0×10 ⁸ Pa or more. (Tetracarboxylic anhydride component)

The polyimide as the component (A) may contain a tetracarboxylic acid residue derived from a tetracarboxylic anhydride generally used for polyimide without particular limitation, but it is preferable to contain all the tetracarboxylic acid residues. A total of 90 mol% or more of tetracarboxylic acid residues derived from tetracarboxylic anhydrides represented by the following general formula (1) are contained. The flexibility of polyimide is easily achieved by containing 90 mol% or more of tetracarboxylic acid residues derived from tetracarboxylic anhydrides represented by the following general formula (1) in total with respect to all tetracarboxylic acid residues Compatibility with heat resistance is preferable. When the total of the tetracarboxylic acid residues derived from the tetracarboxylic anhydride represented by the following general formula (1) is less than 90 mol %, the solvent solubility of the polyimide tends to decrease.

In the general formula (1), X represents a single bond or a divalent group selected from the following formulae.

In the above formula, Z represents -C ₆ H ₄ -, -(CH ₂ )n- or -CH ₂ -CH(-OC(=O)-CH ₃ )-CH ₂ -, and n represents 1 to 20 Integer.

As the tetracarboxylic anhydride represented by the general formula (1), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-benzophenone may, for example, be mentioned. Tetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyltetracarboxylic dianhydride (DSDA), 4,4'-oxydiphthalic anhydride (ODPA), 4 ,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propanedianhydride (BPADA) , p-phenylene bis (trimellitic acid monoester anhydride) (TAHQ), ethylene glycol bis trimellitic anhydride (TMEG), etc. Among these, when 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) is used in particular, the adhesiveness of polyimide can be improved, and in addition, there are molecules present in the molecular skeleton. When a ketone group reacts with an amino group of an amino compound used for crosslinking to be described later to form a C=N bond, the effect of improving heat resistance is likely to be exhibited. From this point of view, it is preferable to contain tetravalent tetracarboxylic acid residues (BTDA residues) derived from BTDA in an amount of preferably 50 mol% or more, more preferably 60 mol% or more with respect to all tetracarboxylic acid residues. ).

The polyimide that is the component (A) may contain a tetracarboxylic acid residue derived from an acid anhydride other than the tetracarboxylic acid anhydride represented by the general formula (1) within a range that does not impair the effects of the invention. Such a tetracarboxylic acid residue is not particularly limited, and examples thereof include pyromellitic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3' - Benzophenone tetracarboxylic dianhydride or 2,3,3',4'-benzophenone tetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic dianhydride , bis(2,3-dicarboxyphenyl) ether dianhydride, 3,3'',4,4''-para-triphenyltetracarboxylic dianhydride, 2,3,3'',4''-paratyle Triphenyltetracarboxylic dianhydride or 2,2'',3,3''-p-triphenyltetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride or 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride ,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride or bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride (2,3-dicarboxyphenyl) sine dianhydride or bis(3,4-dicarboxyphenyl) sine dianhydride, 1,1-bis(2,3-dicarboxyphenyl) ethane dianhydride or 1 ,1-bis(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)tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3 ,6,7-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-dichloronaphthalene-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- Perylene-tetracarboxylic dianhydride, 3,4,9,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride or 5,6,11,12-perylene- Tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4, Aromatics such as 5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride Tetracarboxylic acid residue derived from tetracarboxylic dianhydride. (diamine component)

As the polyimide as the component (A), a diamine component generally used for polyimide can be used without particular limitation as a raw material, but it is preferable to contain 40 mol % with respect to all the diamine components More preferably, it contains 60 mol% or more of aliphatic diamine. That is, the polyimide as the component (A) preferably contains 40 mol % or more of diamine residues derived from aliphatic diamine with respect to all the diamine residues, more preferably 60 mol % above. By containing the diamine residue derived from an aliphatic diamine in the above amount, the dielectric properties of the polyimide can be improved, and the glass transition temperature of the polyimide can be lowered (lower Tg) The resulting improvement in thermocompression bonding properties and the reduction of the elastic modulus achieves alleviation of internal stress. When the diamine residue derived from aliphatic diamine is less than 40 mol % with respect to all the diamine residues, the effect of improving the dielectric loss tangent and thermocompression bonding properties cannot be sufficiently obtained. Here, as the aliphatic diamine, for example, a dimer diamine composition in which the two terminal carboxylic acid groups of the dimer acid are substituted with a primary aminomethyl group or an amino group as a main component can be used. compounds, hexamethylenediamine, dodecanediamine, cyclohexanediamine, polyoxyalkyleneamine, 4,4-diaminodicyclohexylmethane, etc., particularly preferably dimer diamine composition . (dimer diamine composition)

The dimer diamine composition contains the following component (a) as a main component, and the amounts of the component (b) and the component (c) are controlled. (a) dimer diamine

The dimer diamine as the component (a) means that the two terminal carboxylic acid groups (-COOH) of the dimer acid are substituted with a primary aminomethyl group (-CH ₂ -NH ₂ ) or an amino group (-NH ₂ ). The resulting diamine. Dimer acids are known dibasic acids obtained by intermolecular polymerization of unsaturated fatty acids, and as raw materials, natural fatty acids such as soybean oil fatty acid, tall oil fatty acid, rapeseed oil fatty acid, and the like are used. A dimerized fatty acid obtained by carrying out Diels-Alder reaction, such as oleic acid, linoleic acid, linolenic acid, sinapic acid, etc., which are purified from these. It is known that a polybasic acid compound derived from a dimer acid can be obtained in the form of a fatty acid as a raw material or a composition of a trimer or higher fatty acid (for example, Patent Document 4). That is, the industrial production of dimer acid is generally standardized in the industry, and it is obtained by dimerizing an unsaturated fatty acid having 11 to 22 carbon atoms using a clay catalyst or the like. Industrially obtained dimer acids are mainly composed of dibasic acids having 36 carbon atoms obtained by dimerizing unsaturated fatty acids having 18 carbon atoms such as oleic acid, linoleic acid, and linolenic acid. Contains any amount of monomeric acid (18 carbon atoms), trimer acid (54 carbon atoms), and other polymerized fatty acids with 20 to 54 carbon atoms. In addition, the double bond remains after the dimerization reaction, but in the present invention, it is assumed that the dimer acid also includes an acid which further undergoes a hydrogenation reaction to reduce the degree of unsaturation. The dimer diamine that is the component (a) can be defined by substituting a primary aminomethyl group for the terminal carboxylic acid group of a dibasic acid compound having a carbon number in the range of 18 to 54, preferably in the range of 22 to 44. Or amino-derived diamine compounds.

A feature of dimer diamines is that they can impart properties derived from the dimer acid backbone. That is, the dimer diamine is an aliphatic macromolecule with a molecular weight of about 560 to 620, and thus can increase the molar volume of the molecule and relatively reduce the polar group of the polyimide. It is considered that the characteristics of such a dimer acid type diamine contribute to the improvement of the dielectric properties by reducing the relative permittivity and the dielectric loss tangent while suppressing the decrease in the heat resistance of the polyimide. In addition, since it has two freely movable hydrophobic chains having 7 to 9 carbon atoms and two chain-like aliphatic amino groups having a length close to 18 carbon atoms, it is possible not only to impart flexibility to the polyimide, but also to impart flexibility to the polyimide. Since the imide has an asymmetric chemical structure or a non-planar chemical structure, it is considered that the lowering of the dielectric constant of the polyimide can be achieved.

In the dimer diamine composition, the content of the dimer diamine as the component (a) is preferably increased to 96% by weight or more, preferably 97% by weight or more, and more preferably 98% by weight or more by a purification method such as molecular distillation. composition. By setting the content of the dimer diamine as the component (a) to 96% by weight or more, the spread of the molecular weight distribution of the polyimide can be suppressed. In addition, if technically feasible, it is preferable that the whole (100% by weight) of the dimer diamine composition includes the dimer diamine as the component (a).

(b) a monoamine compound obtained by substituting the terminal carboxylic acid group of a monobasic acid compound with a carbon number in the range of 10 to 40 with a primary aminomethyl group or an amino group: The monobasic acid compound with a carbon number in the range of 10 to 40 is a monobasic unsaturated fatty acid with a carbon number in the range of 10 to 20 derived from the raw material of the dimer acid, and a by-product when the dimer acid is produced, that is, the carbon number is A mixture of monobasic acid compounds in the range of 21 to 40. The monoamine compound is a compound obtained by substituting the terminal carboxylic acid group of the monobasic acid compound with a primary aminomethyl group or an amino group.

The monoamine compound which is a component (b) is a component which suppresses the molecular weight increase of polyimide. During the polymerization of polyamic acid or polyimide, the monofunctional amino group of the monoamine compound reacts with the terminal acid anhydride group of the polyamic acid or polyimide, whereby the terminal acid anhydride group is sealed, thereby sealing the terminal acid anhydride group. Inhibits the molecular weight increase of polyimide or polyimide.

(c) An amine compound obtained by substituting the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group with a carbon number in the range of 41 to 80 with a primary aminomethyl group or an amino group (except for the dimer diamine): The polybasic acid compound having a hydrocarbon group having a carbon number in the range of 41 to 80 is a polybasic acid compound mainly composed of a tribasic acid compound having a carbon number in the range of 41 to 80, which is a by-product when producing a dimer acid. In addition, a polymerized fatty acid other than the dimer acid having 41 to 80 carbon atoms may be contained. The amine compound is obtained by substituting the terminal carboxylic acid group of the polybasic acid compound with a primary aminomethyl group or an amino group.

The amine compound as the component (c) is a component that promotes the increase in the molecular weight of the polyimide. The molecular weight of the polyimide is rapidly increased by reacting a trifunctional or higher amino group mainly composed of a triamine body derived from a trimer acid with the terminal acid anhydride group of the polyamic acid or the polyimide. In addition, amine compounds derived from polymerized fatty acids other than dimer acids having 41 to 80 carbon atoms also increase the molecular weight of polyimide and cause gelation of polyimide or polyimide.

In order to easily confirm the peak origin ( peak start), peak top, and peak end, the dimer diamine composition was treated with acetic anhydride and pyridine, and cyclohexanone was used as an internal standard. Each component was quantified using the area percentage of the GPC chromatogram using the sample prepared in the manner described. The peak start point and peak end point of each component can be regarded as the minimum value of each peak curve, and the area percentage of the chromatogram can be calculated based on the minimum value of each peak curve.

In addition, in the dimer diamine composition used in the present invention, the total of the component (b) and the component (c) is preferably 4% or less, preferably less than 4% in terms of the area percentage of the chromatogram measured by GPC. %. By making the total of the component (b) and the component (c) 4% or less, the spread of the molecular weight distribution of the polyimide can be suppressed.

In addition, the area percentage of the chromatogram of the component (b) is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less. By setting it as such a range, the fall of the molecular weight of a polyimide can be suppressed, and the range of the molar ratio of the input of a tetracarboxylic anhydride component and a diamine component can be expanded. Moreover, (b) component may not be contained in a dimer diamine composition.

In addition, the area percentage of the chromatogram of the component (c) is preferably 2% or less, preferably 1.8% or less, and more preferably 1.5% or less. In such a range, the molecular weight of the polyimide can be suppressed from increasing rapidly, and the dielectric loss tangent of the resin film can be suppressed from increasing in a wide frequency range. Moreover, (c) component may not be contained in a dimer diamine composition.

In addition, when the ratio (b/c) of the area percentages of the chromatograms of the component (b) and the component (c) is 1 or more, the molar ratio of the tetracarboxylic anhydride component and the diamine component (tetracarboxylic anhydride component/ The diamine component) is preferably set to 0.97 or more and less than 1.0, and the molecular weight of the polyimide can be more easily controlled by using such a molar ratio.

In addition, when the ratio (b/c) of the area percentages of the chromatograms of the component (b) and the component (c) is less than 1, the molar ratio of the tetracarboxylic anhydride component and the diamine component (the tetracarboxylic anhydride component /diamine component) is preferably 0.97 or more and 1.1 or less, and the molecular weight of the polyimide can be more easily controlled by using such a molar ratio.

The dimer diamine composition is preferably purified for the purpose of reducing components other than the dimer diamine as the component (a). The purification method is not particularly limited, and known methods such as distillation or precipitation purification are preferred. Commercially available products can be used for the dimer diamine composition before purification, and examples thereof include PRIAMINE 1073, PRIAMINE 1074, and PRIAMINE 1075 manufactured by Croda Japan.

Diamine compounds other than aliphatic diamines used for polyimide include aromatic diamine compounds, and specific examples thereof include 1,4-diaminobenzene (p-PDA; p-phenylenediamine), 2 ,2bis-[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenyl ether, 1,3-bis(4-aminophenoxy)benzene, 2,2' -Dimethyl-4,4'-diaminobiphenyl (m-TB), 2,2'-n-propyl-4,4'-diaminobiphenyl (m-NPB), 4-aminophenyl- 4'-Aminobenzoate (APAB), 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfanium , bis[4-(3-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)]benzophenone, 9,9-bis[4-(3-aminophenoxy) )phenyl]fluorene, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl] Hexafluoropropane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-2,6 -Xylidine, 4,4'-methylene-2,6-diethylaniline, 3,3'-diaminodiphenylethane, 3,3'-diaminobiphenyl, 3,3' -Dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4-phenylene bis(1-methylethylene)]dianiline, 4, 4'-[1,3-phenylene bis(1-methylethylene)]dianiline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-tert-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-tert-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, oxazine, 2'-methoxy-4,4'-diaminobenzidine, 4,4'-diaminobenzidine, 1,3-bis [2-(4-Aminophenyl)-2-propyl]benzene, 6-amino-2-(4-aminophenoxy)benzoxazole, 1,3-bis(3-aminophenoxy) Diamine compounds such as benzene.

The polyimide can be produced by reacting the tetracarboxylic acid anhydride component and the diamine component in a solvent to generate polyamide acid and then heating and ring-closing. For example, by dissolving the tetracarboxylic anhydride component and the diamine component in an organic solvent at approximately equimolar levels, and stirring at a temperature in the range of 0 to 100° C. for 30 minutes to 24 hours to carry out a polymerization reaction, a polyamide as a polyamide can be obtained. Polyamides that are precursors of imines. During the reaction, the reaction components are dissolved in the organic solvent so that the produced precursor is in the range of 5 to 50% by weight, preferably in the range of 10 to 40% by weight. As the organic solvent used in the polymerization reaction, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 2-butanone, dimethylsulfoxide (DMSO), hexamethylphosphamide, N-methylcaprolactamide, dimethyl sulfate, cyclohexanone , methylcyclohexane, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), methanol, ethanol, benzyl alcohol, cresol, etc. These solvents may be used in combination of two or more, and aromatic hydrocarbons such as xylene and toluene may also be used in combination. Moreover, although there is no restriction|limiting in particular as usage-amount of such an organic solvent, It is preferable to adjust the usage-amount so that the density|concentration of the polyamic acid solution obtained by a polymerization reaction becomes about 5 weight% - 50weight%.

The synthesized polyamide acid is usually preferably used as a solution in a reaction solvent, and can be concentrated, diluted or replaced with other organic solvents as needed. In addition, polyamic acid is generally favorable for use because of its good solubility in a solvent. The viscosity of the polyamic acid solution is preferably in the range of 500 to 100,000 cps. If it deviates from this range, it is easy to generate|occur|produce inconveniences, such as thickness unevenness and a streak, in a film at the time of coating operation by a coater or the like.

The method for imidizing polyimide to form polyimide is not particularly limited. For example, it can be preferably used in the solvent at a temperature in the range of 80 to 400 ° C for 1 to 24 hours. Heat treatment such as heating is performed. In addition, regarding the temperature, heating may be carried out under a fixed temperature condition, or the temperature may be changed in the middle of the heating step.

In the polyimide as the component (A), the molar ratio of each of the tetracarboxylic anhydride component and the diamine component is selected by selecting the types of the tetracarboxylic anhydride component and the diamine component, or using two or more types of the tetracarboxylic anhydride component or the diamine component. , can control dielectric properties, thermal expansion coefficient, tensile elastic coefficient, glass transition temperature, etc. Moreover, when the polyimide as the component (A) has a plurality of structural units of the polyimide, the polyimide may be present in the form of a block or may be present randomly, and it is preferably present randomly .

The imide group concentration of the polyimide as the component (A) is preferably 22% by weight or less, more preferably 20% by weight or less. Here, the "imide group concentration" refers to a value obtained by dividing the molecular weight of the imide group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. When the imide group concentration exceeds 22 wt %, the molecular weight of the resin itself becomes small, and the low hygroscopicity also deteriorates due to the increase in polar groups, and the Tg and the tensile modulus increase.

The polyimide as the component (A) preferably has a completely imidized structure, but a part of the polyimide may be an imidized acid. The imidization rate can be measured by a Fourier transform infrared spectrophotometer (FT/IR620, manufactured by JASCO Corporation) by the attenuated total reflection (ATR) method on the infrared absorption spectrum of the polyimide film. Using the benzene ring absorber around 1015 cm ^-1 as a reference, it was calculated from the absorbance at 1780 cm ^-1 derived from the C=O expansion and contraction of the imide group.

The weight average molecular weight of the polyimide is preferably, for example, 10,000 to 200,000, and within this range, the control of the weight average molecular weight of the polyimide becomes easy. In addition, when used as an adhesive for FPC, for example, the weight average molecular weight of the polyimide is more preferably in the range of 20,000 to 150,000, and still more preferably in the range of 40,000 to 150,000. When the weight average molecular weight of the polyimide is less than 20,000, there is a tendency for flow resistance to deteriorate. On the other hand, when the weight average molecular weight of the polyimide exceeds 150,000, the viscosity increases excessively and becomes insoluble in the solvent, which tends to cause problems such as uneven thickness of the adhesive layer and streaks during the coating operation. In addition, since the weight average molecular weight greatly varies with the later-described crosslinking formation, it is preferable that the polyimide before the crosslinking formation satisfy the weight average molecular weight. <Component (B): Magnesium oxide filler>

The magnesium oxide filler as the component (B) is a filler mainly composed of magnesium oxide (MgO), and contains 95.0% by weight or more, preferably 98% by weight or more, more preferably 99% by weight or more, and most preferably 99.9% by weight Magnesium oxide above. The higher the purity of the magnesium oxide constituting the filler, the better the dispersibility even if the average particle size is small, and the effect of improving the heat resistance and peeling strength of the solder can be easily obtained while maintaining a low dielectric loss tangent. The magnesium oxide that forms the filler may be a single crystal or a polycrystal, but is preferably a single crystal in terms of obtaining excellent dispersibility even if the average particle size is small. By blending the magnesium oxide filler in the resin composition, the heat resistance and peeling strength of the solder can be enhanced without deteriorating the dielectric loss tangent at the time of forming the resin film.

In addition, the average particle size of the magnesium oxide filler is in the range of 30 nm to 10 μm, preferably in the range of 30 nm to less than 10 μm, more preferably in the range of 30 nm to 5 μm, and still more preferably in the range of 30 nm It is in the range of ~1 μm, preferably in the range of 40 to 300 nm. Within this range, the solder heat resistance and peel strength can be effectively improved without deteriorating the dielectric properties when the resin film is formed. If the average particle size is less than 30 nm, the dispersibility may be lowered, and it may be difficult to form a resin film, or it may be difficult to uniformly disperse when forming a resin film, and there is a fear of causing deterioration of dielectric properties, solder heat resistance, and reduction in peel strength. . If the average particle size exceeds 10 μm, voids may be generated due to an increase in stress due to resin shrinkage in the periphery during film formation, and may appear as unevenness on the film surface, thereby deteriorating the smoothness of the film surface. Here, for the magnesium oxide filler with a particle size of less than 0.4 μm, the particle size conversion by the BET method is applied, and for the magnesium oxide filler with a particle size of 0.4 μm or more, the volume-based fine distribution measurement by the laser diffraction method is applied. obtained particle size.

In particular, magnesium oxide fillers with an average particle size (herein, the average particle size refers to BET-converted particle size, hereinafter referred to as "BET-converted particle size") in the range of 30 to 300 nm, although the particle size is small, have a large particle size. The imide composition (resin solution) has excellent dispersibility in the resin film and has a large effect of improving the solder heat resistance and peel strength, so it is the best. The reason why a magnesium oxide filler having a particle size in the range of 30 to 300 nm in terms of BET is effective in improving solder heat resistance and peel strength is not clear, but the following (1) to (3) can be estimated. (1) Due to the small particle size, excessive stress concentration does not occur in the state of being dispersed in the polyimide as the matrix resin, and microcracks (fine cracks) are generated, but large cracks are unlikely to occur. . (2) When the matrix resin is deformed, many small voids are formed around the filler particles, and the elongation is increased by the many voids. As a result, stress concentration is relieved and microcracks are stabilized. (3) The coefficient of thermal expansion (CTE) of the magnesium oxide filler is as low as about 13 ppm/K, so it can suppress the thermal expansion of the polyimide film at high temperature and ease the stress of the interface with the metal layer.

The magnesium oxide filler having a particle size in the range of 30 to 300 nm in terms of BET is produced by subjecting high-purity metal magnesium vapor and oxygen to vapor phase oxidation reaction to generate and grow crystal nuclei. Therefore, since it is a single crystal and the purity of magnesium oxide is high, it is considered that it has the above-mentioned characteristics.

On the other hand, in the case of alumina fillers commonly used in the field of electronic materials, the interfacial energy is higher than that of magnesia fillers. Therefore, it is considered that the BET conversion particle size is within the range of 30 to 300 nm. It has poor properties and is difficult to apply to polyimide, or has poor wettability with resins, and is unstable even if there are voids. Therefore, the effect of improving solder heat resistance and peel strength like magnesium oxide fillers cannot be obtained.

In addition, the average particle diameter of the magnesium oxide filler varies depending on the purpose, and the average particle diameter may be in the range of 200 nm to 10 μm. In addition, the "particle size" of the magnesium oxide filler can be calculated based on the diameter when it is spherical, and can be calculated based on the major diameter of the filler particles when it is other shapes such as a plate.

In addition, as shown in the test examples described later, when the magnesium oxide filler is heated from 30°C to 450°C at a heating rate of 10°C per minute in thermogravimetric analysis, the weight loss rate at 350°C is preferably 2% or less, More preferably, it is 1.8% or less. The fact that the weight reduction rate in the above temperature range is 2% or less means that magnesium hydroxide (Mg(OH) ₂ ) hardly undergoes dehydration and decomposition, and the content of magnesium hydroxide in the magnesium oxide filler is extremely small. Here, magnesium hydroxide is mixed in the production process of the magnesium oxide filler, or is produced by the surface hydration of magnesium oxide due to the influence of environmental humidity during the storage process after production, but in the present invention, It is preferred to use a magnesium oxide filler with a greatly reduced magnesium hydroxide content.

Furthermore, it is preferable that the magnesium oxide filler detects the peak derived from magnesium oxide and does not detect the peak derived from magnesium hydroxide in X-ray diffraction (XRD) measurement, as shown in the test example mentioned later. When the magnesium oxide filler was measured by the X-ray diffraction method, since the peak derived from magnesium hydroxide was not detected, it was judged that the magnesium oxide filler did not substantially contain magnesium hydroxide. Here, "substantially free of magnesium hydroxide" means that the content of magnesium hydroxide in the magnesium oxide filler is 0.1% by weight or less.

Moreover, the shape of a magnesium oxide filler is not specifically limited, For example, a plate shape, a spherical shape, a polyhedron shape represented by a cube, etc. may be sufficient. Here, the term "plate-like" means, for example, flat, flat, flake-like, scaly-like, etc., and means that the thickness of the filler is sufficiently smaller than the major or minor axis of the flat portion, preferably 1/2 or less. shape.

Magnesium oxide fillers can be surface treated. A known technique can be used for the surface treatment, for example, modification by corona treatment, plasma treatment, ultraviolet light treatment, or the like, functionalization treatment using a silane coupling agent, or the like is preferable. Surface treatment of magnesium oxide fillers can improve the affinity with solvents or polyamides, or improve the mutual repulsion of filler particles, thereby improving the dispersibility of magnesium oxide fillers and the long-term stability of varnishes.

The magnesium oxide filler can be suitably selected from commercially available products. Commercially available magnesium oxide fillers are, for example, high-purity ultra-fine powder magnesium oxide 2000A, high-purity ultra-fine powder magnesium oxide 500A, RF-10CS, RF-10CS-SC, etc. manufactured by Ube Material Company. [Allocation amount]

With respect to the total amount of (A) component and (B) component in the resin composition, the weight ratio of (B) component is in the range of 1 to 50% by weight, preferably in the range of 10 to 45% by weight, 15% by weight. More preferably in the range of ~40% by weight. When the ratio of (B) component with respect to the total amount of (A) component and (B) component is less than 1 weight%, improvement of solder heat resistance and peeling strength may be insufficient. On the other hand, when the ratio of (B) component exceeds 50 weight%, the adhesiveness at the time of forming a resin film will fall, or a resin film will become brittle and bendability will fall. Moreover, when the ratio of (B) component exceeds 50 weight%, the viscosity of a resin composition will become high, and workability|operativity will fall. In addition, when a magnesium oxide filler having a particle size in the range of 30 to 60 nm in terms of BET is contained, from the viewpoint of suppressing aggregation of the filler, the ratio of the (B) component to the total amount of the (A) component and the (B) component is relatively high. Preferably 10% by weight or less, more preferably 5% by weight or less In addition, when preparing the amino compound for crosslinking which will be demonstrated next, the weight ratio of (B) component is calculated using the total weight of the amino compound for crosslinking in the weight of (A) component. [optional ingredients]

When the polyimide as the component (A) has a ketone group, the ketone group and an amino compound having at least two primary amino groups as functional groups (in this specification may be referred to as "a crosslinking amino compound" ”)’s amino group reacts to form a C=N bond, which can form a cross-linked structure. By forming a crosslinked structure, the heat resistance of the thermoplastic polyimide forming the adhesive layer can be improved. Therefore, the resin composition of this embodiment may contain the amino compound for crosslinking as an optional component.

As a preferable tetracarboxylic anhydride in order to form a polyimide having a ketone group, for example, 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) is mentioned, and as a diamine compound, For example, 4,4'-bis(3-aminophenoxy)benzophenone (BABP), 1,3-bis[4-(3-aminophenoxy)benzyl]benzene (BABB) and other aromatic diamines. For the purpose of forming a cross-linked structure, the resin composition of the present embodiment preferably contains polyimide as the component (A), preferably 50 mol of all tetracarboxylic acid residues. % or more, more preferably 60 mol% or more of BTDA residues derived from BTDA; and an amino compound for crosslinking.

As an amino compound for crosslinking formation, (I) dihydrazide compound, (II) aromatic diamine, (III) aliphatic amine, etc. are illustrated. Among them, a dihydrazide compound is preferable. Aliphatic amines other than the dihydrazide compound are likely to form a cross-linked structure even at room temperature, and there is concern about the storage stability of the varnish. On the other hand, aromatic diamines need to be high temperature in order to form a cross-linked structure. In this way, when a dihydrazide compound is used, both the storage stability of the varnish and the shortening of the curing time can be achieved. For example, the dihydrazine compound is preferably oxalic acid dihydrazine, malonic acid dihydrazine, succinic acid dihydrazine, glutaric acid dihydrazine, adipic acid dihydrazine, pimelic acid dihydrazine, caprylic acid dihydrazine Dihydrazine diacid, dihydrazine azelaic acid, dihydrazine sebacate, dihydrazine dodecanedioate, dihydrazine maleate, dihydrazine fumarate, diglycolic acid dihydrazine , dihydrazine tartrate, dihydrazine malate, dihydrazine phthalate, dihydrazine isophthalate, dihydrazine terephthalate, 2,6-naphthalenedicarboxylic acid dihydrazide, 4,4 -Dihydrazine compounds such as diphenyl dihydrazine, 1,4-naphthalenedicarboxylic acid dihydrazine, 2,6-pyridinedicarboxylic acid dihydrazine, and itaconic acid dihydrazine. The above dihydrazide compounds may be used alone or in combination of two or more.

In addition, the amino compounds such as (I) dihydrazide compound, (II) aromatic diamine, (III) aliphatic amine, etc. may be, for example, a combination of (I) and (II), (I) and (III) The combination of (I) and (II) and (III), the supercategory is used in combination of two or more.

In addition, from the viewpoint of making the network structure formed by the crosslinking of the crosslinking amino compound denser, the molecular weight of the crosslinking amino compound used in the present invention (lower in the crosslinking amino compound) In the case of a polymer, the weight average molecular weight) is preferably 5,000 or less, more preferably 90 to 2,000, and still more preferably 100 to 1,500. Among them, particularly preferred is an amino compound for forming a crosslink having a molecular weight of 100 to 1,000. If the molecular weight of the amino compound for cross-linking is less than 90, one amino group of the amino compound for cross-linking is limited to forming a C=N bond with the ketone group of the polyimide resin, and the peripheral steric volume of the remaining amino group increases, so there are The remaining amino groups are less prone to forming C=N bonds.

In the case where the ketone group in the polyimide as the component (A) and the amino compound for crosslinking are formed by crosslinking, the amino compound for forming the crosslinking is added to the resin solution containing the component (A) , the ketone group in the polyimide is subjected to a condensation reaction with the primary amino group of the amino compound used for crosslinking. By the condensation reaction, the resin solution hardens to become a hardened product. In this case, the addition amount of the amino compound for crosslinking can be 0.004-1.5 mol in total, preferably 0.005-1.2 mol, more preferably 0.03 mol per 1 mol of the ketone group. ~0.9 moles, preferably 0.04~0.6 moles. Regarding the addition amount of the amino compound for crosslinking in which the total amount of primary amino groups is less than 0.004 mol relative to 1 mol of the keto group, since the crosslinking by the amino compound for crosslinking is insufficient, there is a possibility that it is difficult to express after curing. the tendency of heat resistance. When the addition amount of the amino compound for crosslinking exceeds 1.5 mol, the unreacted amino compound for crosslinking acts as a thermoplastic agent, and the heat resistance as an adhesive layer tends to decrease.

If the conditions for the condensation reaction for crosslinking are that the ketone group in the polyimide as the component (A) reacts with the primary amino group of the amino compound for crosslinking to form an imine bond (C=N bond) ), there are no special restrictions. Regarding the temperature of the thermal condensation, for reasons such as releasing the water produced by condensation to the outside of the system, or simplifying the condensation step when the thermal condensation reaction is performed after the synthesis of the polyimide as the component (A), for example, It is preferably within the range of 120 to 220°C, more preferably within the range of 140 to 200°C. The reaction time is preferably about 30 minutes to 24 hours. The reaction end point can be measured, for example, by measuring the infrared absorption spectrum using a Fourier transform infrared spectrophotometer (FT/IR620, manufactured by JASCO Corporation), and using the absorption derived from the ketone group in the polyimide resin in the vicinity of 1670 cm ^-1 It was confirmed that the peak decreased or disappeared, and the absorption peak derived from the imine group appeared in the vicinity of 1635 cm ^-1 .

The heating condensation of the ketone group of the polyimide as the component (A) and the primary amino group of the amino compound for crosslinking can be performed, for example, by the following method: (1) A method of adding an amino compound for crosslinking and heating immediately after the synthesis (imidation) of the polyimide as the component (A); (2) Preliminarily put an excess amount of the amino compound as the diamine component, and immediately after the synthesis (imidation) of the polyimide as the component (A), the remainder that does not participate in the imidization or imidization is removed. A method in which an amino compound is utilized as a crosslink-forming amino compound and heated with a polyimide; or (3) A method of heating after processing the resin composition to which the amino compound for crosslinking is added into a predetermined shape (for example, after coating on an arbitrary substrate or after forming into a film).

The case where an imine bond is formed in the formation of the crosslinked structure in order to impart heat resistance to the polyimide as the component (A) has been described above, but the present invention is not limited to this. As the curing method of imide, for example, epoxy resin, epoxy resin curing agent, maleimide, activated ester resin, or resin having a styrene skeleton such as a compound having an unsaturated bond can be prepared and cured.

In the resin composition of the present embodiment, inorganic fillers other than magnesium oxide, organic fillers, plasticizers, hardening accelerators, coupling agents, pigments, and flame retardants can be appropriately blended as necessary within a range that does not impair the effects of the invention. etc. as optional ingredients. Here, examples of inorganic fillers other than magnesium oxide include aluminum oxide, beryllium oxide, niobium oxide, titanium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and magnesium fluoride. , Silicon gallium fluoride, metal phosphinate, etc. These can be used alone or in a mixture of two or more. Moreover, as an optional component, other resin components, such as an epoxy resin, a fluororesin, and an olefin resin, can also be mix|blended, for example.

Furthermore, the resin composition of this embodiment may contain solvents, such as an organic solvent. Since the polyimide as the component (A) is solvent-soluble, the resin composition can be made into a solvent-containing polyimide solution (varnish). The organic solvent may, for example, include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl- 2-pyrrolidone (NMP), 2-butanone, dimethylsulfoxide (DMSO), hexamethylphosphamide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, dioxane, Tetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, cresol, etc. Two or more of these solvents may be used in combination, and aromatic hydrocarbons such as xylene and toluene may be used in combination. The content of the solvent is not particularly limited, but it is preferably used in an amount adjusted so that the concentration of the polyimide or polyimide is about 5 to 30% by weight. [viscosity]

In order to improve the handleability when applying the resin composition and to easily form a coating film with a uniform thickness, the viscosity of the resin composition is preferably in the range of, for example, 3,000 to 100,000 cps, more preferably 5,000 to 50,000 cps. within the range. If it deviates from the said viscosity range, it is easy to generate|occur|produce inconveniences, such as thickness unevenness and a streak, in a film at the time of application|coating operation by a coater etc.. [Preparation of resin composition]

When preparing a resin composition, for example, a magnesium oxide filler can be directly blended in a resin solution of polyamic acid or polyimide prepared using an arbitrary solvent. Alternatively, in consideration of the dispersibility of the magnesium oxide filler, the magnesium oxide filler may be preliminarily prepared in the reaction solvent into which either the acid dianhydride component and the diamine component, which are raw materials of the polyamic acid, are added, and then stirred. Another raw material is put in and the polymerization is carried out. In either method, the total amount of the magnesium oxide filler may be added at one time, or it may be added in small amounts one at a time. In addition, the raw materials can also be added in batches, or can be mixed in small amounts one after another.

The resin composition of the present embodiment is a resin composition having excellent flexibility and thermoplasticity when used to form an adhesive layer. Therefore, for example, in FPC, a rigid/flexible circuit board, etc., it has preferable characteristics in applications, such as the material of an adhesive bond layer, the adhesive agent for coverlay films which protect a wiring part, and the like. [resin film]

The resin film of the present embodiment is a resin film composed of a single layer or a plurality of layers including a thermoplastic resin layer containing a filler, which is the solid content of the resin composition (the remainder after removing the solvent). ) as the main component of the film. That is, the thermoplastic resin layer containing filler contains (A) component and (B) component; (A) a polyimide obtained by reacting a tetracarboxylic anhydride component and a diamine component; and (B) a magnesium oxide filler having an average particle size in the range of 30 nm to 10 μm, However, content of (B) component exists in the range of 1 to 50 weight% with respect to the total amount of (A) component and (B) component. The resin film of this embodiment has excellent high-frequency characteristics and excellent adhesiveness (especially solder heat resistance and peel strength), and can be suitably used as an insulating resin layer of circuit boards such as FPC. In addition, the insulating resin layer of the circuit board contains an adhesive layer and a coverlay material in addition to the insulating base material.

The resin film of the present embodiment is not particularly limited as long as it is a film containing the insulating resin of the filler-containing thermoplastic resin layer, and may be a film (sheet) containing an insulating resin, or may be laminated on a copper foil or a glass plate. , Polyimide-based film, polyamide-based film, polyester-based film and other resin sheets, etc. The state of the insulating resin film on the substrate. (Relative permittivity)

In order to ensure impedance matching when used in circuit boards such as FPC, for example, and to reduce electrical signal loss, the resin film of the present embodiment is conditioned at 10 GHz after 24 hours of humidification under constant temperature and humidity conditions of 23° C. and 50% RH. The relative permittivity (ε) of is preferably 3.3 or less, more preferably 3.1 or less. When the relative permittivity exceeds 3.3, for example, when it is used for a circuit board such as an FPC, problems such as loss of electrical signals are likely to occur in the transmission path of high-frequency signals. (dielectric loss tangent)

In addition, in order to reduce the loss of electrical signals when the resin film of the present embodiment is used for circuit boards such as FPC, for example, when an aliphatic diamine of 40 mol % or more is used as the raw material of the diamine compound, the temperature is 23° C., The dielectric loss tangent (Tanδ) at 10 GHz after dehumidification under a constant temperature and humidity condition of 50% RH for 24 hours is preferably 0.0022 or less, more preferably 0.0020 or less. When the dielectric loss tangent exceeds 0.0022, for example, when it is used for a circuit board such as an FPC, problems such as loss of electrical signals are likely to occur in the transmission path of high-frequency signals. On the other hand, when only aromatic diamine is used as the diamine compound as a raw material, the dielectric loss tangent is preferably 0.015 or less, more preferably 0.010 or less. (glass transition temperature (Tg))

When using 40 mol% or more of aliphatic diamine as a raw material diamine compound of the resin film of this embodiment, Tg becomes like this. Preferably it is 250 degrees C or less, More preferably, it exists in the range of 40 degrees C or more and 200 degrees C or less. By setting the Tg of the resin film to be 250° C. or lower, thermocompression bonding can be performed at a low temperature, internal stress generated during lamination can be relieved, and dimensional changes after circuit processing can be suppressed. When Tg of a resin film exceeds 250 degreeC, the subsequent temperature will become high, and there exists a possibility that the dimensional stability after circuit processing may be impaired. (thickness)

The thickness of the resin film of the present embodiment is preferably within a range of, for example, 5 μm or more and 125 μm or less, and more preferably within a range of 8 μm or more and 100 μm or less. If the thickness of the resin film is less than 5 μm, there is a possibility that defects such as wrinkles may occur at the time of transportation such as production of the resin film. On the other hand, if the thickness of the resin film exceeds 125 μm, the productivity of the resin film will deteriorate. Reduced worry. (tensile elastic coefficient)

The tensile modulus of elasticity of the resin film of the present embodiment is preferably in the range of 0.1 to 3.0 GPa, and more preferably in the range of 0.2 to 2.0 GPa, from the viewpoints of reducing the occurrence of wrinkles, preventing the inclusion of air bubbles during lamination, and handling properties. Inside. (maximum elongation)

The maximum elongation of the resin film of the present embodiment is preferably within the range of 30% to 200%, more preferably 60% to 160%, from the viewpoint of flexibility and crack prevention when used as an insulating resin layer of FPC. In the range.

Since the resin film of the present embodiment has a low dielectric loss tangent and excellent adhesiveness, it is effectively used as an adhesive in an adhesive layer in a coverlay film, a circuit board, a multilayer circuit board, a copper foil with resin, and the like layer, with substrate bonding sheet (bondply), pure glue bonding sheet (bonding sheet), etc. [laminated body]

The laminated body of one Embodiment of this invention has a base material, and the adhesive bond layer laminated|stacked on at least one surface of the said base material, and the adhesive bond layer consists of the said resin film. In addition, the layered body may include selective film layers other than those described above. As a base material in a laminated body, the base material of inorganic materials, such as copper foil and a glass plate, or the base material of resin materials, such as a polyimide-type film, a polyamide-type film, and a polyester-type film, is mentioned. As a preferable form of a laminated body, a coverlay film, a copper foil with resin, etc. are mentioned. [cover film]

A coverlay film, which is one form of the laminate, has a coverlay film material layer as a base material, and an adhesive layer laminated on one side of the layer, and the adhesive layer includes the resin film. In addition, the cover film may include selective film layers other than those described above.

The material of the film material layer for covering is not particularly limited, and for example, polyimide-based films such as polyimide resins, polyetherimide resins, and polyimide-imide resins, or polyimide-based films, polyester film, etc. Among them, preferred is a polyimide-based film having good heat resistance. In addition, in order to effectively express light-shielding properties, concealment properties, design properties, etc., the coating film material may contain a black pigment, and may contain a matting pigment that suppresses surface gloss within a range that does not impair the effect of improving the dielectric properties. Optional ingredients.

Although the thickness of the film material layer for a coating|cover is not specifically limited, For example, it is preferable to exist in the range of 5 micrometers or more and 100 micrometers or less. In addition, the thickness of the adhesive layer is not particularly limited, but is preferably within a range of 10 μm or more and 75 μm or less, for example.

The coverlay film of this embodiment can be manufactured by the method illustrated below. The first method: After applying a varnish-like adhesive composition containing a solvent on one side of the film material layer for covering, for example, it is dried at a temperature of 80 to 180° C. to form an adhesive layer, whereby the film material for covering can be formed. Layer and adhesive layer cover film.

The second method: apply a varnish-like adhesive composition containing a solvent on an arbitrary substrate, and peel it after drying, for example, at a temperature of 80 to 180° C., thereby forming a resin film for an adhesive layer, and applying the resin A cover film can be formed by thermocompression-bonding the film and the film material layer for coverlay at a temperature of, for example, 60 to 220°C. [Copper foil with resin]

The resin-coated copper foil, which is another form of the laminate, is formed by laminating an adhesive layer on at least one side of a copper foil serving as a base material, and the adhesive layer includes the resin film. Moreover, the copper foil with resin of this embodiment may contain the selective film layer other than the above.

The thickness of the adhesive layer in the copper foil with resin is preferably in the range of, for example, 2 to 125 μm, and more preferably in the range of 2 to 100 μm. If the thickness of the adhesive layer is less than the lower limit value, problems such as insufficient adhesiveness cannot be ensured in some cases. On the other hand, when the thickness of the adhesive layer exceeds the upper limit, problems such as a decrease in dimensional stability may occur. In addition, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent, the thickness of the adhesive layer is preferably 3 μm or more.

The material of the copper foil in the copper foil with resin is preferably a material mainly composed of copper or a copper alloy. The thickness of the copper foil is preferably 35 μm or less, and more preferably within a range of 5 to 25 μm. From the viewpoint of production stability and handleability, the lower limit value of the thickness of the copper foil is preferably 5 μm. In addition, the copper foil may be a rolled copper foil or an electrolytic copper foil. Moreover, as copper foil, a commercially available copper foil can also be used.

The copper foil with resin can be prepared by, for example, forming a seed layer by sputtering metal on a resin film, and then forming a copper layer by copper plating, or by laminating a resin film and a copper foil by a method such as thermocompression bonding. preparation. Further, in order to form an adhesive layer on the copper foil, the copper foil with resin can be prepared by casting a coating liquid of the resin composition, drying to form a coating film, and then performing a desired heat treatment. [Metal-clad laminate]

(first form) A metal-clad laminate according to an embodiment of the present invention includes an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, and at least one layer of the insulating resin layer includes the resin film. In addition, the metal-clad laminate of the present embodiment may include selective film layers other than those described above.

(Second form) A metal-clad laminate according to another embodiment of the present invention includes, for example, an insulating resin layer, an adhesive layer laminated on at least one side of the insulating resin layer, and laminated on the insulating resin layer via the adhesive layer. The metal layer M of the so-called three-layer metal-clad laminate, wherein the adhesive layer contains the resin film. In addition, the three-layer metal-clad laminate may include selective film layers other than those described above. The adhesive layer of the three-layer metal-clad laminate may be provided on one or both surfaces of the insulating resin layer, and the metal layer M may be provided on one or both surfaces of the insulating resin layer via the adhesive layer. That is, the three-layer metal-clad laminate may be a single-sided metal-clad laminate or a double-sided metal-clad laminate. A single-sided or double-sided FPC can be manufactured by etching the metal layer M, etc. of the three-layer metal-clad laminate and performing wiring circuit processing.

The insulating resin layer in the three-layer metal-clad laminate is not particularly limited as long as it is made of a resin having electrical insulating properties, and examples thereof include polyimide, epoxy resin, phenol resin, polyethylene, and polypropylene. , polytetrafluoroethylene, silicone, ethylene-tetrafluoroethylene copolymer, etc., preferably including polyimide. The polyimide layer constituting the insulating resin layer may be a single layer or multiple layers, and preferably includes a non-thermoplastic polyimide layer.

The thickness of the insulating resin layer in the three-layer metal-clad laminate is, for example, preferably in the range of 1 to 125 μm, more preferably in the range of 5 to 100 μm. If the thickness of the insulating resin layer is less than the lower limit value, problems such as insufficient electrical insulating properties cannot be ensured in some cases. On the other hand, when the thickness of an insulating resin layer exceeds the said upper limit, inconveniences, such as a metal-clad laminated board, are easy to generate|occur|produce warping.

The thickness of the adhesive layer in the three-layer metal-clad laminate is, for example, preferably in the range of 0.1 to 125 μm, and more preferably in the range of 0.3 to 100 μm. In the three-layer metal-clad laminate of the present embodiment, if the thickness of the adhesive layer is less than the lower limit value, problems such as insufficient adhesiveness cannot be ensured in some cases. On the other hand, when the thickness of the adhesive layer exceeds the upper limit, problems such as a decrease in dimensional stability may occur. In addition, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent of the entire insulating layer as a laminate of the insulating resin layer and the adhesive layer, the thickness of the adhesive layer is preferably 3 μm or more .

In addition, the ratio of the thickness of the insulating resin layer to the thickness of the adhesive layer (thickness of the insulating resin layer/thickness of the adhesive layer) is, for example, preferably in the range of 0.1 to 3.0, and more preferably in the range of 0.15 to 2.0. By setting it as such a ratio, the warpage of a three-layer metal-clad laminate can be suppressed. In addition, the insulating resin layer may contain a filler as needed. Examples of fillers include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, metal salts of organic phosphinic acid, and the like. These can be used alone or in combination of two or more. [circuit board]

The circuit board of the embodiment of the present invention is obtained by performing wiring processing on the metal layer of the metal-clad laminate of any of the above-described embodiments. A circuit board such as an FPC can be produced by processing one or more metal layers of the metal-clad laminate into a pattern by a conventional method to form a wiring layer (conductor circuit layer). In addition, the circuit board may include a cover film covering the wiring layer. [Example]

An Example is shown below, and the characteristic of this invention is demonstrated more concretely. However, the scope of the present invention is not limited to the Examples. In addition, in the following examples, unless otherwise specified, various measurements and evaluations were performed based on the following.

[Measurement method of amine value] Weigh about 2 g of the dimer diamine composition into a 200-250 mL conical flask, use phenolphthalein as an indicator, and add 0.1 mol/L ethanolic potassium hydroxide solution dropwise until The solution was pale pink and was dissolved in approximately 100 mL of neutralized butanol. Add 3~7 drops of phenolphthalein solution to it, and titrate with 0.1 mol/L ethanolic potassium hydroxide solution while stirring, until the solution of the sample becomes light pink. Add 5 drops of bromophenol blue solution to it, and titrate with 0.2 mol/L hydrochloric acid/isopropanol solution while stirring until the sample solution turns yellow. The amine value was calculated by the following formula (1). Amine valence={(V ₂ ×C ₂ )-(V ₁ ×C ₁ )}×M _KOH /m (1) Here, the amine valence is a value represented by mg-KOH/g, and M _KOH is hydrogen The molecular weight of potassium oxide is 56.1. In addition, V and C are the volume and concentration of the solution used in the titration, respectively, and 1 and 2 as subscripts represent 0.1 mol/L ethanolic potassium hydroxide solution and 0.2 mol/L hydrochloric acid/isopropanol solution, respectively. Further, m is the weight of the sample expressed in "grams".

[Measurement of weight average molecular weight (Mw) of polyimide] The weight average molecular weight was measured with a gel permeation chromatograph (HLC-8220GPC manufactured by TOSOH). Polystyrene was used as a standard material, and tetrahydrofuran (THF) was used as a developing solvent. [Calculation of area percentage of GPC and chromatogram]

For GPC, a 100 mg solution obtained by pretreating 20 mg of the dimer diamine composition with 200 μL of acetic anhydride, 200 μL of pyridine, and 2 mL of THF was treated with 10 mL of THF (containing 1000 ppm of cyclohexanone) was diluted to prepare the sample. The prepared samples were measured using HLC-8220GPC manufactured by TOSOH, under the conditions of column: TSK-gel G2000HXL, G1000HXL, flow rate 1 mL/min, column (oven) temperature 40°C, injection amount 50 μL . In addition, cyclohexanone was treated as a standard substance in order to correct the elution time.

At this time, adjustment was made so that the peak apex of the main peak of cyclohexanone was changed from the retention time of 27 minutes to 31 minutes, and the peak start point to the peak end point of the main peak of cyclohexanone was adjusted to be 2 minutes. , the peak apex of the main peak excluding the peak of cyclohexanone is changed from 18 minutes to 19 minutes, and the peak start point to the peak end point of the main peak excluding the peak of cyclohexanone is changed from 2 minutes to 4 minutes Under the conditions of minutes and 30 seconds, each component (a) to component (c) is detected; (a) the composition represented by the main peak; (b) A component represented by a GPC peak detected at a later time based on the minimum value on the time side of the main peak whose retention time is later; (c) A component represented by a GPC peak detected at an earlier time on the basis of the minimum value on the time side with an earlier retention time in the main peak.

[Method for Measuring Particle Size of Filler] For a filler having a particle size of less than 0.4 μm, the particle size in terms of BET was applied. In addition, for fillers with a particle size of 0.4 μm or more, a laser diffraction type fine distribution analyzer (Master Sizer 3000 manufactured by Malvern Corporation) was used, water was used as a dispersion medium, and the particle refractive index was 1.54 by laser diffraction. The particle size was measured by the radiation-scattering method. The value at which the integrated value in the frequency distribution curve obtained by the volume-based fine distribution measurement by the laser diffraction method becomes 50% was taken as the average particle diameter D ₅₀ .

[Measurement of storage elastic coefficient] The measurement was performed using a dynamic viscoelasticity measuring apparatus (DMA: RSA-G2 manufactured by TA Instruments).

[Evaluation of Dielectric Properties] Using a vector network analyzer (E8363C manufactured by Agilent) and a separation column dielectric resonator (SPDR resonator), the polyimide film (hardened polyimide film) was subjected to temperature: 23°C, humidity: 50% After standing under RH conditions for 24 hours, the relative permittivity (ε) and the dielectric loss tangent (Tanδ) at a frequency of 10 GHz were measured.

[Measurement of viscosity] The viscosity (250°C) of the polyamic acid solution was measured using an E-type viscometer (DV-II+Pro manufactured by Brookfield). Set the rotation speed so that the torque is 10% to 90%, and read the value when the viscosity is stable after 2 minutes have elapsed from the start of the measurement.

[Glass transition temperature (Tg)] 1) Adhesive tablet The adhesive sheet pressed at a temperature of 160°C, a pressure of 3.5 MPa, and a time of 60 minutes was cut into test pieces with a size of 5 mm × 20 mm, and a dynamic viscoelasticity measuring device (RSA-G2 manufactured by TA Instrument Co., Ltd.) was used. ), measured from 30°C to 200°C at a temperature increase rate of 4°C/min and a frequency of 11 Hz, and the temperature at which the elastic modulus change (tan δ) became the largest was set as the glass transition temperature. 2) Polyimide layer in CCL For the polyimide film (10 mm×22.6 mm) obtained by etching and removing the copper foil, the dynamic viscoelasticity was measured from 30°C to 450°C at a heating rate of 4°C/min and a frequency of 11 Hz using a dynamic viscoelasticity measuring device. , and obtain the glass transition temperature Tg (maximum value of tanδ).

[tensile elastic coefficient and maximum elongation] Using a tensile tester (Tensilon manufactured by Orientec Co., Ltd.), a tensile test was performed on a test piece (width 12.7 mm, length 127 mm) at 50 mm/min, and the tensile modulus of elasticity and the maximum elongation at 25°C were determined.

[Solder heat resistance test of adhesive sheet] 1) Solder heat resistance test (dry) The single copper foil of the double-sided copper-clad laminate (Espanex MB12-25-12UEG manufactured by NIPPON STEEL Chemical & Material) was etched and removed, and the other copper foil surface and the adhesive sheet were laminated in the form of sandwiching the copper foil. Pressing was performed under the conditions of a temperature of 160° C., a pressure of 3.5 MPa, and a time of 60 minutes. After drying the test piece with the copper foil at 135°C/60 minutes, it was immersed in a solder bath set at each evaluation temperature from 260°C in units of 10°C to 300°C for 10 seconds, and the adhesion state was observed. Check for defects such as foaming, swelling, and peeling. When no defect was observed at 280°C, it was judged as ○ (good), and when a defect was confirmed, it was judged as × (defect). 2) Solder heat resistance test (moisture absorption) The copper foil on one side of the double-sided copper-clad laminate (Espanex MB12-25-12UEG manufactured by NIPPON STEEL Chemical & Material) was removed by etching, and the other copper foil side and the adhesive sheet were laminated with the copper foil sandwiched therebetween. , pressing at a temperature of 160 °C, a pressure of 3.5 MPa, and a time of 60 minutes. After the test piece with copper foil was left to stand at 40°C and 90% relative humidity for 72 hours, it was immersed in a solder bath set to each evaluation temperature from 240°C in units of 10°C to 300°C for 10 seconds, and observed. In the adhesive state, the presence or absence of defects such as foaming, swelling, and peeling was confirmed. When the defect was not confirmed at 260° C., it was judged as ○ (good), and when the defect was confirmed, it was judged as × (defect).

[Solder heat resistance test of polyimide layer in copper clad laminate] The copper-clad laminates prepared in the respective Examples and Comparative Examples were etched so that 20 mmφ remained of the copper foil layer, and were cut into 4 cm in width x 4 cm in length so that the copper foil layer of 20 mmφ was located in the center. Assay samples. The temperature at which swelling, peeling, and melting did not occur was evaluated by immersion in a solder bath set to each evaluation temperature from 220°C in 10°C to 370°C for 60 seconds.

[Measurement of peel strength] 1) Peel strength of adhesive sheet A double-sided copper-clad laminate (Espanex MB12-25-12UEG manufactured by NIPPON STEEL Chemical & Material Co., Ltd.) was cut into a width of 50 mm and a length of 100 mm, and the adhesive sheet was placed on the sample where the copper foil on one side was removed by etching. On the copper foil side, a polyimide film (Kapton 50EN-S manufactured by Toray-Dupont Co., Ltd.) was further laminated on the adhesive sheet, and pressed under the conditions of a temperature of 160°C, a pressure of 3.5 MPa, and a time of 60 minutes to prepare Laminated body. The laminate was cut into a width of 5 mm to prepare a test piece, and the test piece was stretched in the 180° direction at a speed of 50 mm/min using a tensile tester (Strograph VE, manufactured by Toyo Seiki Co., Ltd.), and the measurement at this time was measured. The peel strength of the adhesive layer and the copper foil is used as the peel strength. 2) Copper foil peel strength (peel strength) of copper clad laminates The copper foil layer of the copper-clad laminate was processed to a width of 1.0 mm, and then cut into a width of 8 cm×length of 4 cm to prepare a measurement sample. Using a Tensilon tester (Strograph VE-1D manufactured by Toyo Seiki Co., Ltd.), one side of the measurement sample was fixed to an aluminum plate with double-sided tape, and the other side was 180° in the direction at a speed of 50 mm/min. 10 mm was peeled off, and the central strength at this time was obtained. From a practical viewpoint, a peel strength of 1.0 kN/m or more was evaluated as good "○", and a peel strength of less than 1.0 kN/m was evaluated as poor "x".

[Evaluation method of film retention] The adhesive sheet was cut into a test piece having a width of 20 mm and a length of 20 mm, and was bent so as to form a crease along the diagonal line, and then opened, and the state of the film was observed. At this time, the case where the test piece did not have cracks even after being opened with a crease was set as "good", and the case where cracks occurred in part was set as "no".

[Measurement of Surface Roughness of Copper Foil] The sample was cut into a size of about 10 mm square, fixed to the sample stage with a double-sided tape, irradiated with soft X-rays to remove static electricity from the surface of the copper foil, and then the surface roughness was measured. Using a scanning probe microscope (SPM; atomic force microscope (AFM), Dimension Icon SPM manufactured by Bruker AXS), the arithmetic mean roughness (Ra) and ten-point mean roughness Rz (RzJis ). The measurement conditions are as follows: Measurement mode: tapping mode (tapping mode) Measurement area: 1 μm×1 μm Scanning speed: 1 Hz Probe: RTESP-300 manufactured by Bruker

The abbreviations used in this example represent the following compounds. BTDA: 3,3',4,4'-benzophenone tetracarboxylic dianhydride PMDA: pyromellitic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride DDA: Purified by distillation of PRIAMINE 1075 manufactured by Croda Japan (component a: 99.2%, component b: 0%, component c: 0.8%, amine value: 210 mgKOH/g) BAPP: 2,2bis-[4- (4-Aminophenoxy)phenyl]propane DAPE: 4,4'-diaminodiphenyl ether m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TPE-R: 1,3-Bis(4-aminophenoxy)benzene N-12: Dodecanedioic acid dihydrazide NMP: N-methyl-2-pyrrolidone DMAc: N,N-dimethylacetamide Filler 1 : High-purity superfine magnesium oxide 500A manufactured by Ube Material (magnesium oxide, primary particle: single crystal, cubic shape, purity: magnesium oxide > 99.98%, specific gravity: 3.58, particle size in BET conversion: 52 nm, thermal expansion coefficient: 13 ppm/K) Filler 2: High-purity superfine magnesium oxide 2000A manufactured by Ube Material (magnesium oxide, primary particle: single crystal, cubic shape, purity: magnesium oxide> 99.98%, specific gravity: 3.58, particle size in BET conversion: 200 nm, coefficient of thermal expansion: 13 ppm/K) Filler 3: RF-10CS (magnesium oxide, purity: 99.34% magnesium oxide, specific gravity: 3.58, average particle diameter D ₅₀ : 5.8 μm, minimum particle diameter: 4) manufactured by Ube Material Co., Ltd. μm, maximum particle size ≦45 μm) Filler 4: RF-10CS-SC (magnesium oxide, purity: 98.98% magnesium oxide, specific gravity: 3.58, average particle size D ₅₀ : 6.1 μm, minimum particle size: 6.1 μm) manufactured by Ube Material Co., Ltd. 4 μm, maximum particle size ≦45 μm) Filler 5: Advanced Alumina AA-04 manufactured by Sumitomo Chemical Co., Ltd. (alumina, purity: Alumina ≧ 99.99%, specific gravity: 3.97, average particle size D ₅₀ : 0.5 μm) Filler 6 : KEMGARD 1100 manufactured by HUBER (zinc molybdate magnesium silicate compound, specific gravity: 2.8, average particle size D ₅₀ : 2.0 μm, maximum particle size < 10 μm) Filler 7: SE4050 (silicon dioxide, balls) manufactured by Admatechs shape, average particle diameter _D50 : 400 nm, thermal expansion coefficient: 0.2 ppm/K) In addition, in the above DDA, "%" of a component, b component and c component means the area percentage of the chromatogram in the GPC measurement . In addition, the molecular weight of DDA was calculated by the following formula (2). Molecular weight=56.1×2×1000/amine value…(2)

(Synthesis Example 1) A 1000 ml separable flask was charged with 55.51 g of BTDA (0.1721 mol), 94.49 g of DDA (0.1735 mol), 210 g of NMP and 140 g of xylene, and mixed well at 40°C for 1 hour , to prepare a polyamide solution. The polyimide solution was heated to 190° C., heated and stirred for 10 hours, and 125 g of xylene was added to prepare an imidized polyimide solution 1 (solid content 31% by weight, weight average molecular weight). 80,900, thermoplastic polyimide).

[Example 1] 1.12 g of N-12 and 7.8 g of filler 2 were prepared in 100 g of the polyimide solution 1 prepared in Synthesis Example 1, and xylene was added to dilute and agitate so that the solid content was 31% by weight. A polyimide varnish 1a was prepared.

[Examples 2 to 7] Except having changed the filler and its compounding quantity like Table 1, it carried out similarly to Example 1, and produced the polyimide varnishes 2a-7a.

Comparative Examples 1 and 2 Except having changed the filler and its compounding quantity as shown in Table 1, it carried out similarly to Example 1, and produced the polyimide varnishes 8a and 9a.

Table 1 Polyimide Varnish Example Comparative example 1 2 3 4 5 6 7 1 2 type 1a 2a 3a 4a 5a 6a 7a 8a 9a Polyimide solution 1 [g] 100 100 100 100 100 100 100 100 100 A Solid content of polyimide solution 1 [g] 31 31 31 31 31 31 31 31 31 N-12 [g] 1.12 1.12 1.12 1.12 1.12 1.12 1.12 1.12 1.12 B Filler 1 [g] 0.9 Filler 2 [g] 7.8 12.4 18.6 0.9 Filler 3 [g] 7.8 Packing 4 [g] 7.8 Filler 5 [g] 12.4 Filler 6 [g] 7.8 B/(A+B) [wt%] 19.5 27.9 36.7 19.5 19.5 2.7 2.7 27.9 19.5 B/(A+B) [vol%] 7.2 11.1 15.7 7.2 7.2 0.9 0.9 10.1 9.0 Xylene [g] 17.7 7.1 30.0 17.7 17.7 20.4 20.4 16.0 17.7 Solid content concentration [wt%] 31 31 31 31 31 31 31 31 31

[Example 8] The polyimide varnish 1a prepared in Example 1 was coated on one side of a PET film subjected to mold release treatment, dried at 100° C. for 5 minutes, dried at 120° C. for 10 minutes, and peeled off. This prepared adhesive tablet 1b (thickness: 25 μm). The results of various evaluations of the tablet 1b are as follows: Relative permittivity: 3.1, dielectric loss tangent: 0.0022, tensile modulus: 0.6 GPa, maximum elongation: 125%, Tg: 42°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.7 kN/m

[Example 9] Using the polyimide varnish 2a, the adhesive sheet 2b was prepared in the same manner as in Example 8. The various evaluation results of the tablet 2b are as follows: Relative permittivity: 3.1, dielectric loss tangent: 0.0020, tensile modulus: 0.7 GPa, maximum elongation: 124%, Tg: 43°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.5 kN/m

[Example 10] Using the polyimide varnish 3a, the adhesive sheet 3b was prepared in the same manner as in Example 8. The various evaluation results of the tablet 3b are as follows: Relative permittivity: 3.3, dielectric loss tangent: 0.0019, tensile modulus: 0.8 GPa, maximum elongation: 99%, Tg: 44°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 2.0 kN/m

[Example 11] Using the polyimide varnish 4a, the adhesive sheet 4b was prepared in the same manner as in Example 8. The various evaluation results of the tablet 4b are as follows: Relative permittivity: 2.9, dielectric loss tangent: 0.0020, tensile modulus: 0.7 GPa, maximum elongation: 133%, Tg: 43°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 2.2 kN/m

[Example 12] Using the polyimide varnish 5a, the adhesive sheet 5b was prepared in the same manner as in Example 8. The various evaluation results of the tablet 5b are as follows: Relative permittivity: 2.9, dielectric loss tangent: 0.0020, tensile elastic modulus: 0.7 GPa, maximum elongation: 155%, Tg: 43°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 2.2 kN/m

[Example 13] Using the polyimide varnish 6a, in the same manner as in Example 8, an adhesive sheet 6b was prepared. The various evaluation results of the tablet 6b are as follows: Relative permittivity: 2.7, dielectric loss tangent: 0.0022, tensile modulus: 0.7 GPa, maximum elongation: 130%, Tg: 42°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.3 kN/m

[Example 14] Using the polyimide varnish 7a, an adhesive sheet 7b was prepared in the same manner as in Example 8. The various evaluation results of the tablet 7b are as follows: Relative permittivity: 2.7, dielectric loss tangent: 0.0022, tensile modulus: 0.7 GPa, maximum elongation: 132%, Tg: 42°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.4 kN/m

Comparative Example 3 Using the polyimide varnish 8a, in the same manner as in Example 8, an adhesive sheet 8b was prepared. The various evaluation results of the tablet 8b are as follows: Relative permittivity: 3.1, dielectric loss tangent: 0.0023, tensile modulus: 0.7 GPa, maximum elongation: 142%, Tg: 43°C, film retention: good, solder heat resistance test (dry): ×, Solder heat resistance test (moisture absorption): ×, peel strength: 0.5 kN/m

Comparative Example 4 Using the polyimide varnish 9a, in the same manner as in Example 8, an adhesive sheet 9b was prepared. The various evaluation results of the tablet 9b are as follows: Relative permittivity: 2.8, dielectric loss tangent: 0.0026, tensile modulus: 1.1 GPa, maximum elongation: 103%, Tg: 44°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.4 kN/m

The above results are collectively shown in Table 2.

Table 2 then tablet Example Comparative example 8 9 10 11 12 13 14 3 4 type 1b 2b 3b 4b 5b 6b 7b 8b 9b Relative permittivity 3.1 3.1 3.3 2.9 2.9 2.7 2.7 3.1 2.8 dielectric loss tangent 0.0022 0.0020 0.0019 0.0020 0.0020 0.0022 0.022 0.0023 0.0026 Tensile modulus of elasticity [GPa] 0.6 0.7 0.8 0.7 0.7 0.7 0.7 0.7 1.1 Maximum elongation [%] 125 124 99 133 155 130 132 142 103 Tg [°C] 42 43 44 43 43 42 42 43 44 membrane retention good good good good good good good good good Solder heat resistance test (dry) ○ ○ ○ ○ ○ ○ ○ × ○ Solder heat resistance test (moisture absorption) ○ ○ ○ ○ ○ ○ ○ × ○ Peel strength [kN/m] 1.7 1.5 2.0 2.2 2.2 1.3 1.4 0.5 1.4

From Table 2, it was confirmed that compared with the adhesive sheets 8b and 9b of Comparative Examples 3 and 4, the adhesive sheets 1b to 7b of Examples 8 to 14 improved the solder heat resistance without deteriorating the dielectric properties. , peel strength. From such results, it was confirmed that the adhesive sheet as the resin film of the present embodiment can be expected to reduce transmission loss in a high frequency band of, for example, about 10 to 20 GHz, and to have excellent flexibility and film retention while maintaining flexibility and film retention. Solder heat resistance and peel strength. Synthesis Examples 2 to 4

In order to synthesize the polyamic acid solutions 2 to 4, the diamine components shown in Table 3 were stirred while adding DMAc as a solvent to a 1000 ml separable flask under nitrogen flow so that the solid content concentration shown in Table 3 was obtained. and an acid anhydride component, it was heated at 45 degreeC for 2 hours, and it was made to melt|dissolve. Then, the solution was further stirred at room temperature for 3 hours to carry out the polymerization reaction to prepare the viscous solutions 2 to 4 of the polyamic acid. In addition, in Table 3, the glass transition temperature (Tg) measured by making the polyimide film|membrane of the polyimide obtained in Synthesis Examples 2-4 after imidization is also described.

table 3 Synthesis example Polyamide solution Polyimide type Viscosity [cps] Diamine component (mol parts) Acid anhydride composition (mol parts) Acid/Amine (Ratio) Solid content concentration [quality %] Tg [°C] 2 2 14500 BAPP (100) PMDA (95) BPDA (5) 0.992 15 330 3 3 12000 DAPE (100) BTDA (100) 0.996 15 280 4 4 27000 m-TB (100) PMDA (80) BPDA (20) 0.992 15 400

Synthesis Example 5 In 400 g of the polyamic acid solution 2 prepared in Synthesis Example 2, 2.160 g of the filler 2 was prepared and stirred to prepare a polyamic acid solution 5 (Tg=330°C).

Synthesis Example 6 In 400 g of the polyamic acid solution 3 prepared in Synthesis Example 3, 2.160 g of the filler 2 was prepared and stirred to prepare a polyamic acid solution 6 (Tg=280°C).

Synthesis Example 7 In 400 g of the polyamic acid solution 3 prepared in Synthesis Example 3, 2.160 g of the filler 7 was prepared and stirred to prepare a polyamic acid solution 7 (Tg=280° C.).

[Example 15] Polyamide solution 5 was uniformly coated on the surface of a long electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) so that the thickness after hardening was 12 μm, and then heated and dried at 120°C to remove the solvent. Then, stepwise heat treatment is performed from 120° C. to 360° C. to complete imidization, and a single-sided copper-clad laminate 1 is prepared.

[Example 16] A single-sided copper-clad laminate 2 was prepared in the same manner as in Example 15, except that the polyamic acid solution 6 was used instead of the polyamic acid solution 5.

[Example 17] The polyamide solution 5 was uniformly coated on the surface of the long electrolytic copper foil (Rz=0.8 μm, Ra=0.2 μm) so that the thickness after hardening was 2 μm, and then heated and dried at 120°C to remove the solvent. Next, the polyamic acid solution 4 was uniformly coated thereon so that the thickness after curing was 21 μm, and then the solution was heated and dried at 120° C. to remove the solvent. Further, the polyamic acid solution 5 was uniformly coated thereon so that the thickness after curing was 2 μm, and then the solution was heated and dried at 120° C. to remove the solvent. After the three-layer polyamide layer is formed in the above-mentioned manner, stepwise heat treatment is performed from 120° C. to 360° C. to complete imidization, and a single-sided copper-clad laminate 3 is prepared.

[Example 18] A single-sided copper-clad laminate 4 was prepared in the same manner as in Example 17, except that the polyamic acid solution 6 was used instead of the polyamic acid solution 5.

Comparative Example 5 A single-sided copper-clad laminate 5 was prepared in the same manner as in Example 15, except that the polyamic acid solution 3 was used instead of the polyamic acid solution 5.

Comparative Example 6 A single-sided copper-clad laminate 6 was prepared in the same manner as in Example 15, except that the polyamic acid solution 7 was used instead of the polyamic acid solution 5.

Comparative Example 7 A single-sided copper-clad laminate 7 was prepared in the same manner as in Example 17, except that the polyamic acid solution 3 was used instead of the polyamic acid solution 5.

The evaluation results of Examples 15 to 18 and Comparative Examples 5 to 7 are shown in Tables 4 and 5 below.

Table 4 Example 15 16 17 18 Solder heat resistant 370℃ 370℃ 370℃ 370℃ Peel strength with copper foil ○ ○ ○ ○ Relative permittivity (10 GHz) 3.3 3.5 3.4 3.7 Dielectric Loss Tangent (10 GHz) 0.009 0.015 0.006 0.008

table 5 Comparative example 5 6 7 Solder heat resistant 320℃ 370℃ 320℃ Peel strength with copper foil × × × Relative permittivity (10 GHz) 3.5 3.5 3.7 Dielectric Loss Tangent (10 GHz) 0.015 0.015 0.008

According to Tables 4 and 5, by mixing the magnesium oxide filler in the polyimide layer in contact with the copper foil, the comparative examples 5 and 7 without the filler and the comparative example where the spherical silica filler was mixed are shown. 6, both solder heat resistance and peel strength can be improved. [Test Example 1]

Determination of weight loss rate: Thermogravimetric measurement was performed in order to ascertain the state of formation of magnesium hydroxide by hydration of magnesium oxide. The magnesium oxide samples (1) to (5) shown below were measured from 30°C at a rate of 10°C/min using a thermogravimetric analyzer (TG; TG/DTA7220 manufactured by Hitachi High-Tech Science) in a nitrogen atmosphere. The temperature was raised to 450°C, the weight loss at 350°C in this case was measured, and the weight loss rate accompanying thermal decomposition of magnesium hydroxide was obtained.

Samples (1) to (5) all used the aforementioned "filler 2". Sample (1): Shortly after opening Sample (2): After opening, put it in a reagent bottle and store it in a laboratory at room temperature and humidity for 1 year (open and close the lid every time you use it) Sample (3): After opening, it was exposed to an environment with a temperature of 40°C and a humidity of 90% for 24 hours Sample (4): After opening, it was exposed to a temperature of 40°C and a humidity of 90% for 48 hours Sample (5): After opening, it was exposed to a temperature of 40°C and a humidity of 90% for 72 hours

The results of thermogravimetric analysis are shown in FIG. 1 . As can be seen from Figure 1, the weight reduction rates of samples (1) to (5) at 350°C are 0.36%, 1.46%, 0.85%, 1.59%, and 1.85%, respectively, all of which are less than 2%. The weight loss rate was the smallest, and the weight loss rate increased in the order of sample (3), sample (2), sample (4), and sample (5). From this result, it was confirmed that magnesium hydroxide was gradually generated by hydration of magnesium oxide depending on the environmental humidity. [Test Example 2]

The sample (1) used in Test Example 1 was subjected to X-ray diffraction measurement by a wide-angle X-ray diffraction method under the following conditions using an X-ray diffraction apparatus (SmartLab (rotating cathode) manufactured by Rigaku Corporation). X-ray source: MoKα rays (using Kβ filter) Output: 60 kV, 150 mA Slit system: CBO condenser mirror Detector: Hypix-3000 (1D mode) Scanning mode: 2θ/θ continuous scanning Measuring range (2θ): 5°～50° Step width (2θ): 0.01° Scanning speed: 4°/min

The results of the X-ray diffraction measurement are shown in FIG. 2( a ), and for reference, the peak position of Mg(OH) ₂ in the X-ray diffraction measurement is shown in FIG. 2( b ). In addition, based on the result of FIG. 2(a), the ratio of magnesium hydroxide was calculated by Rietveld analysis, and as a result, MgO was 100% by weight and Mg(OH) ₂ was 0% by weight.

From the above, it was confirmed that in the X-ray diffraction measurement of the sample (1), the peak derived from magnesium oxide was detected, but the peak derived from magnesium hydroxide was not detected. Specifically, peaks derived from magnesium oxide were detected at 2θ of 16.8°, 19.4°, 27.6°, 32.5°, and 34.0°, but not at 2θ of 8.5°, 17.3°, 22.8°, and 26.1° From the peak derived from magnesium hydroxide, it was confirmed that sample (1) does not substantially contain magnesium hydroxide.

As shown in each of the above examples, by adding a magnesium oxide filler to the polyimide, a clear improvement in solder heat resistance and improvement in peel strength can be seen without deteriorating the dielectric properties. Furthermore, it was confirmed that the adhesive sheet obtained in each Example maintained the shape as a film at the compounding amount of the magnesium oxide filler within a practical range.

From the results described above, it was confirmed that the resin film of the present embodiment can be suitably used as a material for circuit boards such as high-frequency compatible FPCs.

As mentioned above, although embodiment of this invention was described in detail for illustration purpose, this invention is not limited by the said embodiment, Various deformation|transformation is possible.

none

FIG. 1 shows the results of the thermogravimetric analysis of Test Example 1. FIG. FIG. 2 shows the results of X-ray diffraction measurement in Test Example 2. FIG.

Claims (18)

A resin composition containing the following (A) components and (B) components: (A) a polyimide obtained by reacting a tetracarboxylic anhydride component and a diamine component; and (B) a magnesium oxide filler having an average particle size in the range of 30 nm to 10 μm, However, content of the said (B) component exists in the range of 1 to 50weight% with respect to the total amount of the said (A) component and the said (B) component. The resin composition according to claim 1, wherein the magnesium oxide filler contains 95.0% by weight or more of magnesium oxide. The resin composition according to claim 1, wherein when the magnesium oxide filler is heated from 30°C to 450°C at a heating rate of 10°C per minute in thermogravimetric analysis, the weight loss rate at 350°C is 2 %the following. The resin composition according to claim 1, wherein the magnesium oxide filler has no peak derived from magnesium hydroxide detected in X-ray diffraction measurement. The resin composition according to claim 1, wherein the diamine component contains 40 mol% or more of aliphatic diamine relative to all the diamine components, and the magnesium oxide filler has an average particle diameter of 200 nm ~10 μm range. The resin composition according to claim 5, wherein the aliphatic diamine is a dimer diamine in which the two terminal carboxylic acid groups of the dimer acid are substituted with a primary aminomethyl group or an amino group as the main component The dimer diamine composition. The resin composition according to claim 1, further comprising an amino compound having at least two primary amino groups as functional groups. A resin film comprising a filler-containing thermoplastic resin layer, The filler-containing thermoplastic resin layer contains the following (A) components and (B) components: (A) a polyimide obtained by reacting a tetracarboxylic anhydride component and a diamine component; and (B) a magnesium oxide filler having an average particle size in the range of 30 nm to 10 μm, However, content of the said (B) component exists in the range of 1 to 50weight% with respect to the total amount of the said (A) component and the said (B) component. The resin film according to claim 8, wherein the magnesium oxide filler contains 95.0% by weight or more of magnesium oxide. The resin film according to claim 8, wherein when the magnesium oxide filler is heated from 30°C to 450°C at a temperature increase rate of 10°C per minute in thermogravimetric analysis, the weight reduction rate at 350°C is 2% the following. The resin film according to claim 8, wherein the magnesium oxide filler has no peak derived from magnesium hydroxide detected in X-ray diffraction measurement. The resin film according to claim 8, wherein the diamine component contains 40 mol % or more of aliphatic diamine relative to all the diamine components, and the magnesium oxide filler has an average particle diameter of 200 nm to 200 nm. in the range of 10 μm. The resin film according to claim 8, wherein after the filler-containing thermoplastic resin layer is conditioned for 24 hours under constant temperature and humidity conditions of 23°C and 50% RH, the dielectric properties at 10 GHz are measured by a separation column dielectric resonator. The electrical loss tangent is 0.0022 or less. A laminated body comprising: substrate; and An adhesive layer laminated on at least one surface of the base material, the adhesive layer including the resin film according to claim 8. A cover film comprising: a layer of film material for covering; and An adhesive layer laminated on the cover film material layer, the adhesive layer including the resin film according to claim 8. A copper foil with resin is formed by laminating an adhesive layer and a copper foil, wherein the adhesive layer includes the resin film according to claim 8. A metal-clad laminate, comprising: an insulating resin layer; and a metal layer laminated on at least one side of the insulating resin layer, Wherein, at least one layer of the insulating resin layer includes the resin film according to claim 8. A circuit board obtained by performing wiring processing on the metal layer of the metal-clad laminate according to claim 17 .

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